Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/09/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
900 AM MST SUN JUL 7 2013
.SYNOPSIS...HIGH PRESSURE ALOFT WILL BE NEAR THE FOUR CORNERS REGION
THIS WEEK. ADEQUATE MOISTURE WILL PROVIDE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS EARLY THIS WEEK WITH TEMPERATURES WELL
ABOVE AVERAGE. ANOTHER SURGE OF MOISTURE WILL LEAD TO INCREASED
THUNDERSTORM ACTIVITY BY WEDNESDAY.
&&
.DISCUSSION...STILL SORTING THROUGH SOME DEBRIS THIS MORNING FROM
OVERNIGHT CONVECTION IN NORTHWEST MEXICO. OVERALL WE HAVE A LITTLE
LESS MOISTURE TO WORK WITH AS SOME MID LEVEL DRYING TRIES TO WORK IN
BUT 12Z SOUNDING STILL HAD ABOUT 1.35 (IN LINE WITH BLENDED
SATELLITE ESTIMATES) WHICH IS PLENTY TO WORK WITH. STILL A WEAK
SOUTHERLY FLOW AT MOST LEVELS BUT A LITTLE BETTER THAN YESTERDAY.
NOT THE GREATEST WIND AND THERMAL PROFILE FOR STRUCTURE BUT OVERALL
SIMILAR TO YESTERDAY WITH SLIGHTLY BETTER SUPPORT FOR SLOW MOVING
STORMS WANDERING INTO SOME VALLEY LOCATIONS.
LATEST HI RES RR AND 12Z UOFA NAMWRF HAVE EASY DEVELOPMENT OVER
MOUNTAIN LOCATIONS ON SCHEDULE WITH BETTER COVERAGE BY MID TO LATE
AFTERNOON FOR SOME LOWER DESERT LOCATIONS SOUTHWEST AND WEST OF
TUCSON IN AN AREA OF WEAK MOISTURE CONVERGENCE. WE ADJUSTED FIRST
AND EARLY SECOND PERIOD TRENDS TO REFLECT THIS AS WELL AS A SLIGHT
INCREASE IN VALLEY COVERAGE OVERALL.
&&
.PREV DISCUSSION...HIGH PRESSURE ALOFT CENTERED OVER SRN NEW MEXICO
EARLY THIS MORNING. UPPER HIGH IS PROGGED TO DRIFT NWD TO THE FOUR
CORNERS REGION BY MON AFTERNOON...THEN REMAIN QUASI-STATIONARY THRU
THURSDAY. SUFFICIENT MOISTURE WILL YIELD ISOLATED-SCATTERED SHOWERS/
TSTMS MOSTLY FROM TUCSON EWD/SWD THIS AFTERNOON AND THIS EVENING.
COVERAGE OF SHOWERS/TSTMS IS EXPECTED TO GRADUALLY EXPAND WWD TO
ENCOMPASS THE ENTIRE CWA BY WED AFTERNOON AND WED EVENING.
THE 07/00Z ECMX MOS DEPICTS A SIGNIFICANT INCREASE IN POPS FOR KTUS
TUE. AM SOMEWHAT CONCERNED ABOUT A POTENTIAL GULF OF CALIFORNIA
SURGE AS EARLY AS TUE ATTRIBUTED TO TROPICAL SYSTEM ERICK. FOR NOW
HAVE MAINTAINED A GRADUAL POP INCREASE TUE VERSUS MON. THUS...CHANCE-
CATEGORY POPS EAST/SOUTH OF TUCSON TUE AFTERNOON AND TUE EVENING
WITH A SLIGHT CHANCE OF SHOWERS/TSTMS FROM TUCSON WWD.
POPS EXHIBIT A GRADUAL INCREASE WED-FRI AS DEEPER SELY FLOW IS
PROGGED TO OCCUR IN RESPONSE TO THE UPPER HIGH BECOMING POSITIONED
OVER THE CENTRAL CONUS. AT THIS TIME...TOO DIFFICULT TO DISCERN
WHICH DAY MAY BE THE PROVERBIAL UP-DAY...AND WHICH DAY MAY HAVE A
DOWNTURN IN CONVECTIVE ACTIVITY. AT ANY RATE...THERE IS A CHANCE OF
MAINLY AFTERNOON/EVENING SHOWERS/TSTMS FROM TUCSON EWD/SWD WED-FRI...
AND A SLIGHT CHANCE OF SHOWERS/TSTMS ACROSS WRN SECTIONS. HAVE
CONTINUED WITH A SLIGHT DECREASE IN PRECIP CHANCES SAT.
HIGH TEMPS FOR THE TUCSON METRO AREA THRU WED WILL AVERAGE ABOUT 3-5
DEGS F ABOVE NORMAL. DAYTIME TEMPS THUR-SAT ARE FORECAST TO BE
WITHIN A DEGREE-OR-TWO OF NORMAL.
&&
.AVIATION...VALID THRU 08/16Z...
ISOLD-SCT TSRA FROM THIS AFTERNOON THROUGH 08/06Z. THUNDERSTORM WIND
GUSTS 40-45 KTS WITH THE STRONGEST STORMS. OTHERWISE...12K FT
SCT-BKN THROUGH THIS MORNING BECOMING 12K FT SCT CLOUDS THIS
AFTERNOON WITH THE ISOLD-SCT TSRA. WIND GENERALLY AROUND 10 KTS AWAY
FROM THE THUNDERSTORMS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS EACH AFTERNOON
AND EVENING THROUGH TUESDAY ESPECIALLY IN THE HIGHER ELEVATIONS.
BECOMING SCATTERED THUNDERSTORMS FROM WEDNESDAY THROUGH THE END OF
THE WEEK. THE STRONGER THUNDERSTORMS WILL PRODUCE GUSTY AND ERRATIC
WINDS. OTHERWISE...NORMAL DIURNAL WIND TRENDS WILL OCCUR THROUGHOUT
THE WEEK. DAYTIME RELATIVE HUMIDITIES WILL RANGE FROM THE UPPER
TEENS TO 30S WITH GOOD NIGHTTIME RECOVERIES. AN INCREASE IN RELATIVE
HUMIDITY MID-WEEK COINCIDING WITH THE INCREASED STORM ACTIVITY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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MEYER/BF/SAMPSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
921 PM MST SAT JUL 6 2013
.SYNOPSIS...A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE DESERT
SOUTHWEST THIS WEEKEND EXPANDING EASTWARD EARLY NEXT WEEK. THIS
RIDGE WITH OCCASIONAL WEAK DISTURBANCES ROTATING AROUND
IT...COMBINED WITH MOISTURE ACROSS THE AREA WILL PROVIDE A CHANCE OF
SHOWERS AND THUNDERSTORMS EARLY IN THE NEW WEEK. INCREASED ACTIVITY
IS POSSIBLE THE SECOND HALF OF THE WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A SWATH OF MID LEVEL DRY AIR
ACROSS MUCH OF THE EASTERN PACIFIC...CALIFORNIA...NORTHERN SONORA
MEXICO AND SOUTHWEST ARIZONA. MEANWHILE...MORE MOIST AIR RESIDES TO
THE EAST AND THIS INTERFACE BETWEEN THE DRIER AND MORE MOIST AIR IS
SERVING AS A FOCUS FOR CONVECTIVE DEVELOPMENT WHICH TRIGGERED STORMS
SOUTH OF NOGALES AND ALSO OVER THE TOHONO O`ODHAM NATION...CENTRAL
PIMA COUNTY AND WESTERN PORTIONS OF PINAL COUNTY. THIS CLUSTER OF
STORMS WILL CONTINUE TO MOVE TO THE NORTH BETWEEN MARANA AND CASA
GRANDE THIS EVENING.
ELSEWHERE ACROSS SOUTHEAST ARIZONA ISOLATED THUNDERSTORMS HAVE
RECENTLY DEVELOPED ALONG THE ARIZONA/NEW MEXICO BORDER...ALONG
INTERSTATE 10 NEAR SAN SIMON...AND THESE STORMS ARE ALSO MOVING
NORTH.
THE RUC HRRR MODEL INDICATED THAT THE CLUSTER OF STORMS NORTHWEST OF
TUCSON AND INTO PINAL COUNTY WILL CONTINUE TO MOVE NORTH AND OUT OF
MY FORECAST AREA THIS EVENING...WITH NO SIGNIFICANT DEVELOPMENT
THEREAFTER. HOWEVER...GIVEN THE STORMS ALONG THE NEW MEXICO
BORDER...AND OLD OUTFLOW BOUNDARIES MOVING HERE AND THERE...WILL
KEEP SOME MENTION OF ISOLATED SHOWERS AND THUNDERSTORMS IN THE
FORECAST THROUGH THE REMAINDER OF THE NIGHT.
AS OF 04Z (9 PM MST)...TEMPERATURES ACROSS THE REGION RANGED FROM
THE MID 70S TO THE LOWER 90S...WITH THE TUCSON INTL AIRPORT
REPORTING A TEMP OF 93 DEGS AFTER REACHING A HIGH OF 103 DEGS. THESE
CURRENT READINGS SEEM TO BE ON TRACK WITH REGARD TO THE OVERNIGHT
LOWS...SO NO CHANGES ARE PLANNED AT THIS TIME...BUT WILL CONTINUE TO
MONITOR.
&&
.AVIATION...ISOLATED TO SCATTERED T-STORMS MAINLY NORTHWEST OF
TUCSON THROUGH AROUND 06Z...THEN ONLY EXPECTING ISOLATED TSTMS
THEREAFTER. WIND GUSTS WILL APPROACH 40-45 KTS WITH THE STRONGEST
TSTMS THROUGH 06Z. OTHERWISE...VFR CONDITIONS WITH DIURNALLY DRIVEN
WINDS TO OCCUR THRU SUNDAY AFTERNOON. ANOTHER ROUND OF ISOLATED TO
SCATTERED TSTMS DEVELOPING AGAIN LATE SUNDAY AFTERNOON AND INTO THE
EVENING HOURS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ON SUNDAY...EXPECT ISOLATED TO SCATTERED
AFTERNOON/EVENING THUNDERSTORMS. THEREAFTER...SCATTERED MAINLY
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR DURING THE UPCOMING
WEEK FROM TUCSON EASTWARD...WITH ISOLATED THUNDERSTORMS WEST OF
TUCSON. THE STRONGER THUNDERSTORMS WILL PRODUCE STRONG...GUSTY AND
ERRATIC WINDS. OTHERWISE...NORMAL DIURNAL WIND TRENDS WILL OCCUR
THIS WEEKEND AND DURING THE UPCOMING WEEK. DAYTIME RELATIVE
HUMIDITIES NEXT WEEK WILL RANGE FROM THE MID TEENS TO 20S WITH GOOD
NIGHTTIME RECOVERIES.
&&
.CLIMATE...TODAY HAS BEEN THE 36TH CONSECUTIVE DAY WITH TEMPERATURES
IN EXCESS OF 100 DEGREES AT TUCSON INTERNATIONAL AIRPORT...4TH
LONGEST ALL TIME.
&&
.PREVIOUS DISCUSSION...WITH WEAK FLOW AND STRUCTURE WE WILL PROBABLY
LIMP ALONG AT A LOW GRADE THUNDERSTORM FORECAST TO START THE NEW
WEEK. THE HIGH PRESSURE AND LESS PERVASIVE CLOUD COVER SHOULD ALLOW
FOR TEMPERATURES ON THE HOTTER SIDE 5 TO 8 DEGREES ABOVE CLIMO.
SURGE ACTIVITY ASSISTED BY TROPICAL INFLUENCES AS EARLY AS TUESDAY
NIGHT WITH AN INVERTED TROUGH PUSHING ACROSS PORTIONS OF NORTHWEST
MEXICO BY MID WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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CURRENT DISCUSSION...MOLLERE
PREVIOUS DISCUSSION...MEYER/GLUECK
AREA FORECAST DISCUSSION
NWS EUREKA CA
425 AM PDT SUN JUL 7 2013
.SYNOPSIS...EXPECT A TRANQUIL WEATHER PATTERN WITH SEASONAL
TEMPERATURES THIS WEEK. THE INTERIOR SHOULD BE MOSTLY CLEAR WHILE
THE COAST CAN EXPECT OVERNIGHT CLOUDS AND FOG WITH CLEARING EACH
AFTERNOON.
&&
.DISCUSSION...THE FORECAST REMAINS ON TRACK. CLOUDS OVER PORTIONS
OF NORTHWEST CALIFORNIA SHOULD DISSIPATE THIS MORNING AND
AFTERNOON, THOUGH PROBABLY NOT AS QUICKLY AS DAYS PAST SINCE THE
MARINE LAYER IS MORE ENTRENCHED ALONG THE COAST THIS MORNING. BUT
WHEN THE CLOUDS DO DISSIPATE ONE CAN EXPECT A NICE SUMMER DAY.
EXPECT A TRANQUIL WEATHER PATTERN WITH SEASONAL TEMPERATURES THIS
WEEK. SKIES WILL BE CLEAR ACROSS THE INTERIOR WITH SOME AFTERNOON
CLOUDS OVER THE HIGHER TERRAIN. WINDS THERE WILL BE MOSTLY LIGHT
AND TERRAIN-DRIVEN DURING THE DAY AND THEN LIGHT AND OFFSHORE AT
NIGHT. THE COAST CAN EXPECT OVERNIGHT CLOUDS AND FOG WITH CLEARING
EACH AFTERNOON. MINOR COOLING IS EXPECTED BY THE MIDDLE OF THE
WEEK AS A WEAK TROUGH PASSES OVER THE WEST COAST. BUT TEMPERATURES
SHOULD ONLY COOL A FEW DEGREES, MAINLY ACROSS THE INTERIOR.
&&
.AVIATION...LOW CLOUDS AND SOME LIGHT FOG CONTINUE TO HUG THE NW
CA COAST WITH CLOUDINESS EXTENDING INLAND UP THE COASTAL RIVER
VALLEYS N OF CAPE MENDO. AGREE WITH PREVIOUS FORECASTER WITH LATER
CLEARING TIME AT KACV TODAY. CURRENT TAF SET HAS ABOUT A 7 HOUR
WINDOW OF NO CIG AT KACV AND THIS MAY ACTUALLY NEED TO BE
NARROWED...BUT BOTH THE NAM AND RUC HINT THAT CLOUDINESS SHOULD
SCATTER OUT AROUND 21Z. TRICKIER FORECAST AT KCEC. NAM AND RUC
GRIDDED DATA SHOW MINIMAL CLOUD COVER DURING THE DAY...BUT NAM AND
GFS MOS SHOW CIGS MOST OF THE DAY. LOW CLOUDS HAVE EXPANDED N
ALONG THE COAST TO KCEC OVER THE PAST SEVERAL HOURS ON COASTAL S
FLOW. EXPECT NORTHERLIES TO RETURN LATER THIS MORNING. THIS...IN
CONCERT WITH EROSION FROM THE E DUE TO DAYTIME HEATING AND AN AREA
OF DOWNSLOPING UPSTREAM...MAY HELP CLOUDS ERODE BY LATE MORNING OR
EARLY AFTERNOON. LOW CLOUDS HAVE REACHED KSTS. WITH LIGHT S FLOW
AROUND THAT AREA...WILL NEED TO WATCH THIS CLOUD DECK IN CASE IT
MAKES A RUN AT KUKI. OTHERWISE...VFR EXPECTED AT THAT AIRPORT.
/SEC
&&
.MARINE...RATHER STRAIGHTFORWARD FORECAST DOMINATED BY SHORT
PERIOD WIND DRIVEN WAVES THRU THE PERIOD. HAVE EXTENDED THE N
OFFSHORE GALE WARNING THRU THE AFTERNOON HOURS DUE TO WIND GUSTS.
THIS MAY NEED TO BE EXPANDED FURTHER BY THE DAY SHIFT. OTHER
HEADLINES REMAIN UNCHANGED. SWAN MODEL APPEARS TO HAVE A BETTER
HANDLE ON WAVE HEIGHTS WITH INITIALIZATION MATCHING FAIRLY WELL
WITH LOCAL BUOYS. WINDS ARE FORECAST TO SLOWLY DECREASE INTO
TUE...THEN PICK UP A BIT AROUND MID-WEEK. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
GALE WARNING FOR PZZ470.
HAZARDOUS SEAS WARNING FOR PZZ475.
SMALL CRAFT FOR PZZ450-455-475.
&&
$$
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 PM MDT SAT JUL 6 2013
.UPDATE...
ISSUED AT 725 PM MDT SAT JUL 6 2013
UPDATED TO BUMP UP POPS ACROSS THE FAR EASTERN PLAINS WHERE
CLUSTER OF SHOWERS/THUNDERSTORMS CONTINUES. 23Z HRRR SLOWLY SHIFTS
THIS EASTWARD AND HANGS ON TO SOME SPOTTY QPF NEAR THE EASTERN
BORDER AFTER MIDNIGHT. IT ALSO DEVELOPS ANOTHER BAND OF
SHOWERS/EMBEDDED THUNDERSTORMS ACROSS THE CENTRAL MOUNTAINS WHICH
SHIFTS INTO THE SOUTHEAST MOUNTAINS AROUND 06Z BEFORE DIMINISHING
AS IT HEADS EASTWARD ACROSS THE SOUTHERN I-25 CORRIDOR AFTER 10Z.
SO FAR...HRRR SEEMS OVERDONE WITH THIS LATER BATCH OF
CONVECTION...BUT HAVE INTRODUCED SOME ISOLATED POPS OVER THE
MOUNTAIN AREAS THROUGH 08Z TO ACCOUNT FOR THE POSSIBILITY OF
LINGERING CONVECTION WITHIN MOISTURE PLUME. WILL WAIT FOR 00Z
NAM12 RUN TO ARRIVE BEFORE EXTENDING POPS THROUGH THE NIGHT FOR
MOST AREAS AS HRRR SUGGESTS. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 245 PM MDT SAT JUL 6 2013
...EARLY GLIMPSE OF THE MONSOON UNDERWAY...
EARLY MONSOONAL AIRMASS OVER SOUTHERN COLORADO THIS WEEKEND WITH
SURFACE DEWS NOW IN THE 40S AND 50S PRETTY MUCH ANY WHICH WAY YOU
LOOK. ALOFT...PLENTY OF MID/HIGH LEVEL MONSOON MOISTURE CIRCULATING
AROUND LARGE MEW MEXICO HIGH PRESSURE AREA. VERY LITTLE COLD AIR
ALOFT ASSOCIATED WITH LARGE HIGH SETTING THE STAGE FOR TYPICAL
DIURNAL AFTERNOON AND EVENING THUNDERSTORM ACTIVITY PRODUCING MOSTLY
RAIN AND MAYBE A LITTLE BIT OF SMALL HAIL...WITH OTHER THREATS
INCLUDING LIGHTNING AND LOCALLY GUSTY WINDS UP TO AROUND 50 MPH.
MONSOONAL MOISTURE IS NOT REAL GREAT YET...WITH PRECIPITABLE WATERS
RANGING FROM A SOUTHERN COLORADO MAX OF A LITTLE OVER AN INCH ACROSS
THE SOUTHEAST TIP OF BACA COUNTY TO A MIN AROUND 3 QUARTERS OF AN
INCH ACROSS THE NORTHWEST TIP OF LAKE COUNTY. BUT...SURELY BETTER
THAN A COUPLE DAYS AGO...AND ADEQUATE FOR SOME LOCALLY HEAVY
RAINERS. THERE IS CERTAINLY ENOUGH WATER IN THE ATMOSPHERE FOR
CONCERN OVER SOME OF THE NEWER AREA BURN SCARS INCLUDING THE
WALDO...EAST PEAK AND WEST FORK SCARS. VIGILANCE MUST CONTINUE IN
THESE AREAS FOR THE FORESEEABLE FUTURE...STARTING WITH THIS
AFTERNOON AND EVENING.
AS IN RECENT DAYS...MOST THUNDERSTORM ACTIVITY SHOULD DIE DOWN
ACROSS THE AREA BY AROUND 04Z OR SO...WITH CONVECTIVE DEBRIS
LINGERING AND GRADUALLY DISSIPATING AFTER THAT. FEEL THAT MOST
ACTIVITY WILL BE COMPLETELY OVER BY MIDNIGHT...ALTHOUGH THERE COULD
BE A FEW STRAGGLERS THROUGH THE NIGHT...COVERING LESS THAN ONE
PERCENT OF THE FORECAST AREA. LW
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 245 PM MDT SAT JUL 6 2013
...MONSOON SEASON IS UPON US...
LOOKS LIKE A FAIRLY NORMAL SUMMER PATTERN WILL BE WITH US FOR THE
COMING WEEK. FORECAST TEMPS AND PRECIP WILL BE INFLUENCED BY THE
OVERALL PATTERN...INCLUDING THE POSITION OF THE RIDGE AND H5 HIGH
OVER THE SW U.S. THE UPPER HIGH WILL START OFF OVER THE 4 CORNERS
REGION ON MONDAY AND TUESDAY. THIS CAN BE A FAVORABLE MONSOONAL
PATTERN...BUT IN THIS PARTICULAR CASE THE UPPER RIDGE WILL BE
FLATTENED BY A SHORT WAVE MOVING THROUGH SW AND SRN CANADA...SO
UPPER WINDS WILL BE GENERALLY WESTERLY AND BRINGING RELATIVELY DRY
AIR IN FROM THE W AND SW. HOWEVER...THE SHORTWAVE COULD SPARK A FEW
HIGH BASED STORMS...PARTICULARLY OVER THE ERN MTS AND PLAINS LATE
MONDAY AND AGAIN ON TUESDAY.
TUESDAY NIGHT...A WEAK FRONT ASSOCIATED WITH THE SHORT WAVE NOW
MOVING INTO THE GREAT LAKES REGION WILL PUSH OVER ERN CO. THE UPPER
HIGH WILL HAVE MIGRATED SLIGHTLY EWD INTO NW NM. THIS WILL SET THE
STAGE FOR AN UP-TICK IN PRECIP ON WED...ESPECIALLY OVER THE MTS BUT
EXTENDING EWD ONTO THE PLAINS BY WED EVE.
THURSDAY...THE MONSOON PLUME RETURNS TO WRN CO AS THE UPPER HIGH
CONTINUES TO DRIFT SLIGHTLY TO THE W OVER NRN NM. A FAIRLY ROBUST
MOISTURE PLUME THEN LOOKS TO AFFECT THE AREA FRI AND THROUGH THE
WEEKEND. AT THIS TIME...IT LOOKS LIKE THE BULK OF THE HEAVIER
CONVECTION WILL BE OVER THE CENTRAL MTS...WHICH COULD BRING AN
INCREASED THREAT OF FLASH FLOODING TO THE MT AREAS...AND
PARTICULARLY THE WEST FORK BURN...THROUGH THE WEEKEND.
DAYTIME HIGH TEMPS WILL BE A BIT TRICKY TO FORECAST THIS COMING
WEEK. THE H5 HEIGHTS AND H7 TEMPS JUSTIFY HIGH TEMPS IN THE UPPER
90S OR EVEN LOW 100S FOR SEVERAL DAYS OVER THE LOWER ARKANSAS AND
ERN PLAINS. AT THIS TIME...SINCE THE MONSOONAL MOISTURE APPEARS TO
AFFECT MAINLY THE CENTRAL MTS...IF IT STAYS DRY ENOUGH THESE HIGH
TEMPS WILL BE REALIZED...AND THIS IS WHERE THE FORECAST TREND HAS
BEEN FOR THE DAILY HIGHS. HOWEVER...IT DOES APPEAR THAT AT LEAST
MODEST MID LEVEL MOISTURE WILL BE TRAPPED UNDER THE RIDGE...AND
COULD BRING AT LEAST ISOLD TO SCT CONVECTION OVER THE PLAINS EACH
DAY. IF THIS HAPPENS...THEN THE DAY TIME HIGHS COULD BECOME A RACE
BETWEEN REALIZING THE WELL MIXED VALUES DOWN FROM H7-H5...AND THE
DEVELOPMENT OF EARLY AFTERNOON THUNDERSTORMS...WHICH COULD BRING
DOWN TEMPS IN A HURRY FOR THE PLAINS. HOPEFULLY...THE PLUME WILL
SHIFT FAR ENOUGH E AT SOME POINT THAT MORE DEEP MOISTURE CAN MOVE
OVER THE PLAINS. ROSE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1116 PM MDT SAT JUL 6 2013
VFR CONDITIONS EXPECTED ACROSS THE FORECAST AREA...INCLUDING THE 3
MAIN TAF SITES OF KCOS...KPUB AND KALS...FOR THE NEXT 24 HRS.
THERE IS THE THREAT OF ISOLATED TO SCATTERED CONVECTION FIRING
OVER THE HIGHER TERRAIN EACH AFTERNOON...THEN MOVING EAST ACROSS
THE ADJACENT PLAINS THROUGH THE LATE AFTERNOON AND EARLY EVENING.
PRIMARY STORM THREATS INCLUDE LIGHTNING...PERIODS OF HEAVY
RAIN...AND GUSTY ERRATIC WINDS UP TO 50 MPH.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
SHORT TERM...LW
LONG TERM...ROSE
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
756 PM EDT MON JUL 8 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH SOUTH INTO SOUTHERN NEW
ENGLAND TODAY. THE FRONT WILL STALL THIS EVENING ACROSS SOUTHERN
NEW ENGLAND AND LINGER ACROSS THE AREA TOMORROW...FOLLOWED BY A
WARM FRONT ALLOWING FOR MORE WIDESPREAD PRECIPITATION ON
WEDNESDAY. TEMPERATURES WILL BE LESS HOT...BUT THE HUMIDITY WILL
LINGER.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
730 PM UPDATE...
KBOX 88D SHOWING TWO MESOSCALE BOUNDARIES VERY WELL AS THEY CRIS-
CROSS SOUTHERN NEW ENGLAND. LATEST HRRR RUN HAD THE RIGHT IDEA
WITH DEVELOPING STORMS ALONG THESE BOUNDARIES...BUT WAS PERHAPS A
BIT TOO AGGRESSIVE IN ITS COVERAGE. LOWERED POPS SLIGHTLY THIS
EVENING DUE TO THE ISOLATED NATURE OF THE CONVECTION. STILL
EXPECTING IT TO FIZZLE WITHIN A FEW HOURS AS WE GET PAST SUNSET.
STORMS ARE MOVING...AND WHILE SOME ARE PUTTING DOWN DECENT
RAINFALL RATES...WE NO LONGER EXPECT SIGNIFICANT FLOODING ISSUES.
AS SUCH THE FLASH FLOOD WATCH WAS CANCELED.
ONLY OTHER CHANGES WERE TO TWEAK TEMPERATURES AND DEW POINTS TO
BRING THEM INTO LINE WITH OBSERVED TRENDS.
PREVIOUS DISCUSSION...
FOCUSING ON THE STORM POTENTIAL THREAT...CONTINUED TO HAVE LOW
CONFIDENCE. STORM ANALYSIS SHOWS THAT ML CAPE VALUES ARE AROUND
1000 J/KG WHILE BULK SHEAR IS NEAR 20-35 KTS ESPECIALLY ACROSS
EASTERN MA. PWAT VALUES ARE NEARING 1.7 INCHES SO MAIN CONCERN FOR
ANY CONVECTION AT THIS POINT IS HEAVY RAIN AND LIGHTNING. LOW
LEVEL LAPSE RATES ARE NEARING 7-8 C/KM WHILE SURFACE LI ARE -4.
DESPITE ALL OF THESE FACTORS...CELLS CONTINUE TO STRUGGLE THIS
AFTERNOON DUE TO LACK OF DEEP MOISTURE. HOWEVER SOME MESOSCALE
MODELS DO INDICATE THAT THIS MOISTURE WILL FILTER INTO WESTERN NEW
ENGLAND LATER THIS AFTERNOON...AROUND 20-22Z SO THIS AREA MAY NEED
TO BE WATCHED.
FLASH FLOODING IS ALSO A CONCERN AS STORMS MAY TRAIN A LITTLE.
HAVE EXPANDED THE FLASH FLOOD WATCH AS THE BETTER POTENTIAL FOR
THE STRONG STORMS LOOKS TO BE ACROSS CENTRAL INTO NE MASS AS WELL
S NH. THEREFORE CONTINUED THE WATCH IN HOPE THAT A CLEARER PICTURE
FOR STORM DEVELOPMENT POTENTIAL OCCURS WITHIN THE HOUR.
TONIGHT...ANY CONVECTION THAT DEVELOPS SHOULD WANE AFTER SUNSET
AS DIURNAL HEATING IS LOST. SOME MESOSCALE MODELS TO INDICATE THAT
A FEW SHOWERS WILL LINGER TIL AFTER MIDNIGHT. OTHERWISE THE FOCUS
TURNS TO THE FOG POTENTIAL FOR TONIGHT. CURRENT VISIBLE SATELLITE
IMAGERY SHOWS A GOOD STRATUS DECK JUST OFFSHORE OF THE EAST COAST
SO EXPECT THAT TO FILTER IN ONCE THE DIURNAL HEATING IS LOST.
BUFKIT SOUNDING ALSO SHOW FOG DEVELOPMENT ACROSS THE REGION ALONG
ALL SHORES. THE BEST CHANCE IS ACROSS THE EAST COAST AS BOUNDARY
WILL ALLOW FOR EASTERLY FLOW OVERNIGHT. SOUTH SHORE WILL BE LESS
OF A SHOT BUT STILL BELIEVE ITS A POSSIBILITY. NO DENSE FOG
ADVISORY AT THIS TIME.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
TOMORROW...SOME UNCERTAINTY LIES FOR TOMORROW. HAVE A LOW
CONFIDENCE IN THE OVERALL FORECAST. SLIGHT RIDGING IN THE MID-
LEVELS WILL LOWER THE CHANCE FOR STORMS TOMORROW. HOWEVER SEEMS
THAT THE SOUTHERN HALF OF THE REGION MAY HAVE A POTENTIAL. STILL
UNCERTAIN ON WHERE EXACTLY THIS BOUNDARY WILL END UP. MODELS
INDICATE THAT IT WILL WORK ACROSS CT/RI AND SE MA...HOWEVER WE
LOSE THE UPPER LEVEL SUPPORT. THEREFORE HAVE DECIDED NOT TO ISSUE
A FLASH FLOOD WATCH FOR TOMORROW AS THERE IS A LOT OF UNCERTAINTY.
HOPEFULLY THE MIDNIGHT CREW WILL GET A BETTER SET OF GUIDANCE THAT
WILL HELP DETERMINE WHAT WILL HAPPEN FOR TOMORROW.
EASTERLY FLOW WILL STILL CONTINUE ACROSS THE EASTERN PORTION OF
THE REGION SO TEMPS WILL CONTINUE TO BE COOLER ACROSS THE EAST
PORTION. WHERE AS THE SOUTHERN PORTION SHOULD SEE THE HIGHER
TEMPS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* WARM AND HUMID CONDITIONS CONTINUE THROUGH MOST OF THIS WEEK
* A BETTER CHANCE FOR MORE WIDESPREAD SHOWERS AND STORMS WED-FRI
OVERVIEW AND MODEL PREFERENCES...
LONG RANGE GUIDANCE SUITE CONTINUES TO SHOW RELATIVELY DECENT
AGREEMENT REGARDING THE LONG TERM SETUP BUT HAVE DISAGREEMENTS LATE
THIS WEEK AND WEEKEND REGARDING THE AMPLITUDE OF THE MID-LEVEL FLOW
PATTERN. WPC CONTINUES TO FAVOR THE ECENS MEAN...WHICH WITH THIS
LATEST SET OF MODEL RUNS...HAS SUPPORT FROM BOTH THE GEFS MEAN AND
EVEN THE OPERATIONAL GFS TO SOME EXTENT WHILE THE ECMWF OPERATIONAL
RUN APPEARS TO BE THE MORE MERIDIONAL OUTLIER. THEREFORE...TO KEEP
CONSISTENCY GIVEN THE LOWER CONFIDENCE IN THE EXACT SET UP BY NEXT
WEEKEND...WILL CONTINUE TO TREND THE FORECAST GRIDS WITH THE ECENS
VIA THE WPC...WITH BIT OF THE LATEST GFS GIVEN THE AGREEMENT.
FOR THE SLIGHTLY SHORTER TIMERANGE...A GENERAL MODEL BLEND SHOULD
PROVIDE ADEQUATE TIMING GIVEN VERY GOOD AGREEMENT THOUGH THURSDAY.
CURRENT EXPECTATIONS ARE FOR THE RIDGING OVER THE ATLANTIC TO BREAK
DOWN OVER THE COURSE OF THIS WEEK...WITH A HIGH AMPLITUDE MID-LEVEL
TROUGH ARRIVING LATE THIS WEEK INTO THIS WEEKEND. THE QUESTION
WHICH REMAINS IS HOW LONG THIS TROUGH WILL BE ABLE TO LINGER IN OUR
VICINITY EARLY NEXT WEEK. THERE IS ALSO THE ISSUE WITH THE PROXIMITY
OF THE BERMUDA HIGH REESTABLISHING ITSELF EARLY NEXT WEEK. LOTS OF
UNCERTAINTY REGARDING THIS PORTION OF THE FORECAST.
DETAILS...
TUESDAY NIGHT INTO WEDNESDAY...ANY CONVECTION THAT WAS ALLOWED
TO FIRE WITHIN THE WEAK UPPER LEVEL RIDGE ON TUESDAY IS EXPECTED
TO COME TO AN END EARLY TUESDAY NIGHT WITH A PERIOD OF GENERALLY
DRY CONDITIONS INTO THE EARLY DAY WED. DURING THE DAY
WEDNESDAY...A SURFACE WARM FRONT WILL APPROACH THEN CROSS THE
REGION LATE IN THE DAY. WILL BE CONTINUING WITH CHANCE AND LIKELY
POPS WITH THIS FEATURE. THIS IS PRIMARILY DUE TO DEEP MOISTURE AND
SOME CONDITIONAL INSTABILITY IN MODEL SOUNDINGS ALONG WITH THE
FRONT COMBINED WITH THE LIFT AND SHEAR TYPICALLY COINCIDENT WITH
THESE WARM FRONTS. THE KEY TO HOW MUCH/STRONG ANY POTENTIAL
CONVECTION WILL BE IS DEPENDENT SOMEWHAT ON THE EARLY MORNING
CLOUD COVER...WHICH MAY BE NEAR BKN-OVC GIVEN REMNANT CONVECTIVE
DEBRIS.
THURSDAY AND FRIDAY...THERE ARE TIMING ISSUES HERE LIKELY DUE TO
THE DIFFERENCES REGARDING HOW DEEP A POTENTIAL EASTERN CONUS
CUTOFF DEVELOPS. HOWEVER...DO EXPECT A SLOWING COLD FRONT TO MOVE
ACROSS THE REGION FROM THE WEST...POTENTIALLY STALLING NEAR THE
SOUTH COAST BY FRIDAY. INITIALLY...GIVEN IT APPEARS MUCH OF SRN
NEW ENGLAND WILL BREAK INTO THE WARM SECTOR AHEAD OF THIS
FRONT...IT APPEARS INSTABILITY WILL BE ENOUGH TO SUPPORT SOME
CONVECTION WITH DECENT SHEAR AND VERY HIGH /NEAR 2.0 INCHES AGAIN/
PRECIPITABLE WATER VALUES.
THE HIGHER POTENTIAL FOR STRONGER CONVECTION APPEARS TO BE
THURSDAY...ESPECIALLY IF THE SLOWER SOLUTION IS CORRECT SINCE IT
WILL ARRIVE LATE IN THE DAY AND A FRONT WILL LIKELY STALL NEARBY.
HOWEVER...THE PERIOD LOOKS TO BE WET WITH SOME DRYING POSSIBLE
FROM NW TO SE LATE AS THE DRIER AIR BEHIND THIS FRONT FILTERS IN.
IT/S DIFFICULT TO SAY HOW QUICKLY THIS WILL OCCUR...SO WILL BE
KEEPING MOSTLY CHANCE TO SLIGHT CHANCE POPS AROUND THE REGION
THROUGH THE PERIOD. TEMPS WILL TRANSITION TO LIKELY ABOVE NORMAL
TO NEAR- SLIGHTLY ABOVE NORMAL...BUT HUMIDITY WILL REMAIN HIGH.
THIS COMING WEEKEND...
A FAIR AMOUNT OF UNCERTAINTY REGARDING SENSIBLE WEATHER DETAILS
THIS PERIOD WHICH WILL BE STRONGLY DEPENDENT ON WHERE A SOUTH TO
NORTH MOISTURE STREAM AND LOW LEVEL FRONT ULTIMATELY SET UP.
DESPITE THE UPPER LVL SIMILARITIES BETWEEN THE ECENS AND GFS
HERE...THEIR SFC FEATURES ARE IN DISAGREEMENT. SHOULD THIS FRONT
AND MOISTURE STREAM HOLD CLOSER TO THE COASTLINE /MORE SIMILAR TO
ECENS/ THIS PERIOD WOULD LIKELY BE WET. THE GFS IS A BIT DRIER
BECAUSE IT IS QUICKER ALLOWING FOR THE RETROGRADING BERMUDA HIGH
TO ONCE AGAIN INFLUENCE THE WX. WILL AT LEAST BE SUGGESTING SOME
POPS THROUGH THE PERIOD AS EVEN THE DRIER GFS WOULD SUGGEST THE
POSSIBILITY OF DIURNAL CONVECTION WHILE THE ECENS WOULD BE MORE
BROADLY WET.
EARLY NEXT WEEK...
ONCE AGAIN A FAIR AMOUNT OF UNCERTAINTY...BUT SHOULD THE BERMUDA
HIGH AND WESTERN ATLANTIC RIDGE BEGIN TO MOVE WEST WITH TIME...A
TRANSITION TOWARD HOTTER WEATHER IS POSSIBLE.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...TODAY THROUGH TUESDAY...
AFTER 00Z...SHOWERS/TSTMS CONTINUE EARLY AT NIGHT AND THEN
DIMINISH. ONCE AGAIN AREAS OF FOG/LOW CLOUDS ALONG THE SOUTH COAST
ESPECIALLY THE CAPE AND ISLANDS. PATCHY FOG WITH REDUCED
CIGS/VSBYS ALSO POSSIBLE INLAND ESPECIALLY AT AIRPORTS THAT SAW
RAIN IN THE AFTERNOON/EVE.
ALSO EXPECTING A FOG/STRATUS BANK EAST OF MA TO MOVE WEST WITH THE
EASTERLY FLOW AND COOLING BOUNDARY LAYER. THIS WILL INCLUDE KBOS.
TUESDAY...
ANOTHER DISTURBANCE RIDES ALONG THE STALLED FRONT AND BRINGS
ANOTHER ROUND OF SHOWERS/TSTMS. AS WITH TODAY...CONDITIONS WILL
GENERALLY BE VFR BUT WITH TSTMS GENERATING LOWER CIGS/VSBYS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. MORE CERTAINTY WITH
TRENDS. LOW CONFIDENCE ON TIMING SPECIFICS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. MORE CERTAINTY WITH
TRENDS. LOW CONFIDENCE ON TIMING SPECIFICS.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
CONTINUED HIGH CONFIDENCE IN OVERALL TRENDS BUT LOWER CONFIDENCE
IN EXACT TIMING OF ANY LOWER CATEGORIES THROUGH THE PERIOD.
LITTLE CHANGE IN THE EXPECTED CONDITIONS WITH THIS UPDATE.
MAINLY VFR IS EXPECTED UNTIL AT LEAST WEDNESDAY. THE ONLY CAVEATS
WILL BE THE THREAT FOR OVERNIGHT MVFR/IFR CONDITIONS IN LOCALIZED
FOG AND AN OCCASIONAL MVFR VSBY/CIG IN ISOLATED SHOWERS/T-STORMS
DURING THE AFTERNOONS/EVENINGS. THESE WILL BE VERY LOCALIZED AND
ARE NOT EXPECTED TO AFFECT ALL AIRPORTS.
A STRONGER SYSTEM MAY ALLOW FOR MORE WIDESPREAD MVFR/IFR
CONDITIONS WEDNESDAY THROUGH THURSDAY WITH MORE WIDESPREAD
RAINFALL. THESE CONDITIONS LIKELY TO LINGER INTO FRIDAY AS A COLD
FRONT APPROACHES FROM THE WEST. VFR MORE LIKELY ACROSS THE
INTERIOR SATURDAY...WITH MVFR POSSIBLE FARTHER EAST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...MODERATE TO HIGH CONFIDENCE.
TONIGHT THROUGH TUESDAY...
WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS.
HUMID AIR AND LIGHT FLOW WILL ALLOW FOR FOG THIS EVENING INTO THE
OVERNIGHT HOURS WHICH SHOULD LIFT BY MIDDAY TOMORROW.
THERE IS A LOW PROBABILITY FOR A CHANCE OF SHOWERS/TSTMS TOMORROW
AS WELL.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
THROUGH EARLY WEDNESDAY...CONDITIONS GENERALLY REMAIN BELOW
SMALL CRAFT THRESHOLDS. SOME FOG MAY LEAD TO LOW VSBYS...
PARTICULARLY LATE TUESDAY NIGHT.
LATE WEDNESDAY INTO SATURDAY...A STRONGER LOW PRESSURE WILL PASS
WELL NORTH AND WEST OF THE WATERS. HOWEVER...SOUTHWEST WINDS WILL
INCREASE AND MAY REACH 25 KT AT TIMES. SEAS SHOULD BUILD THROUGH
THIS PERIOD. THE BEST CHANCE FOR 5 FOOT PLUS SEAS WILL BE ACROSS
THE OCEAN WATERS AND NEARSHORE WATERS SOUTH OF RI AND THE ISLANDS.
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.HYDROLOGY...
ISOLATED TO SCATTERED THUNDERSTORMS STILL HAVE THE POTENTIAL TO
DEVELOP. THERE ARE ALSO AREAS THAT HAVE HAD HEAVY DOWNPOURS
RESULTING IN FLASH FLOODING OVER THE PAST FEW DAYS. PWAT VALUES
WILL BE NEAR 1.7 TO 2 INCHES ABOVE NORMAL WHICH WILL RESULT IN
SIGNIFICANT HEAVY DOWNPOURS. BOTH OF THESE REASONS PLAY INTO THE
DECISION TO CONTINUE THE FLASH FLOOD WATCH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...BELK
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
HYDROLOGY...
AREA FORECAST DISCUSSION...CORRECTED
NWS ALBANY NY
123 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST THROUGH THIS AFTERNOON. THIS WILL ALLOW MOISTURE TO
MOVE BACK INTO THE REGION...INCREASING THE RISK OF SHOWERS AND
THUNDERSTORMS. TONIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE
WILL MOVE BACK INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER
UNSETTLED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE DEVELOPING WITH QUITE A BIT OF
INSTABILITY OVER THE REGION. FREEZING LEVELS AND -20C LEVELS QUITE
HIGH...BUT THERE COULD BE A STORM OR TWO THAT COULD PRODUCE SOME
STRONG GUSTY WINDS...AND HEAVY RAIN IS ALWAYS A THREAT WITH
LOCALIZED FLASH FLOODING. JUST SOME MINOR ADJUSTMENTS TO THE
TEMPERATURES AND RAIN CHANCES THROUGH THIS AFTERNOON.
THE LOCAL WRF AND HRRR SUGGEST AN ACTIVE AFTERNOON AND EVENING
ACROSS THE REGION.
HEAT INDICES IN THE MID HUDSON VALLEY AND NW CT WILL TOUCH 100 AT
TIMES THIS AFTERNOON BUT NOT WIDESPREAD ENOUGH OR LONG ENOUGH
DURATION FOR A SHORT FUSE HEAT ADVISORY. HEAT INDICES HAVE BEEN
NEAR 100 THE PAST COUPLE OF AFTERNOONS AND HEAT INDICES A DEGREE
OR TWO WARMER THIS AFTERNOON SHOULD FEEL NEARLY THE SAME AS THE
PAST COUPLE OF AFTERNOONS.
PREVIOUS DISCUSSION DESCRIBES THE FACTORS AFFECTING CONVECTION
THIS AFTERNOON AND EVENING AND IS BELOW..
QUITE AN INSTABILITY GRADIENT HAS ALREADY SET UP ACROSS THE
AREA...SINCE LOCATIONS TO THE SOUTH OF ALBANY DID NOT HAVE ANY
CLOUDS/SHOWERS MOVE THROUGH EARLIER AND INSTEAD HAD SUNSHINE.
COMBINED WITH A RETURN IN LOW LEVEL MOISTURE...THIS HAS ALLOW
SBCAPE VALUES TO SURGE IN TO THE 2000-3000 J/KG RANGE LATE THIS
MORNING. TO THE NORTH A RATHER SHARP INSTABILITY GRADIENT NOW
EXISTS...ALTHOUGH IT WILL BECOME SOMEWHAT MORE UNIFORM BY EARLY
AFTERNOON DUE TO PARTIAL SUNSHINE HEATING THIS AREA AS WELL.
HOWEVER...THE INSTABILITY GRADIENT AND DIFFERENTIAL HEATING THAT
OCCURRED MAY RESULT IN AN AREA TO WATCH FOR ENHANCED CONVECTION BY
EARLY TO MID AFTERNOON. ANOTHER SOURCE OF ASCENT COULD BE A
SUBTLE IMPULSE MOVING NORTHEASTWARD FROM THE UPPER LOW OVER THE
OHIO VALLEY...THAT COULD TRACK THROUGH PA/NY THIS AFTERNOON AND
EVENING. SO KEPT MENTION OF SCATTERED THUNDERSTORMS WITH
RELATIVELY HIGH POPS OF 5O PERCENT. MESOSCALE MODELS SHOWING
CONVECTION INITIATING ACROSS MUCH OF THE AREA THIS AFTERNOON...AND
SOME STORMS COULD BE STRONG BASED ON HOW TALL UPDRAFTS ARE ABLE
TO GET.
DEEP LAYER SHEAR AROUND 25-35 KT IS SUFFICIENT FOR STORM
ORGANIZATION...ALTHOUGH ONCE AGAIN MID LEVEL LAPSE RATES REMAIN
RATHER MARGINAL AROUND 6.0 C/KM AND HIGH FREEZING LEVELS OVER 14
KFT. WITH MODERATE TO HIGH LEVELS OF INSTABILITY...WILL HAVE TO
WATCH FOR WET MICROBURST POTENTIAL AND ONCE AGAIN HEAVY RAIN AND
POSSIBLE ISOLATED FLASH FLOODING WITH THE STRONGER AND SLOW MOVING
T-STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
WHILE THE AFOREMENTIONED DISTURBANCES WILL MOVE ON BY THIS
EVENING...THE ACTUAL UPPER AIR LOW LOOKS TO MOVE OUR WAY LATE
TONIGHT INTO MONDAY. THIS WILL SERVE TO COOL THE ATMOSPHERE A LITTLE
BUT THE WIND FIELD (BULK SHEAR) LOOKS WEAK. SHOWERS AND STORMS LOOK
TO DIMINISH IN AREA DURING THE EVENING...BUT COULD REKINDLE LATER
OVERNIGHT INTO EARLY MONDAY. LOWS OVERNIGHT WILL BE MUGGY...65 TO 70
DEGREES.
WE EXPECT PLENTY OF CLOUDS AROUND WITH THIS FEATURE INTO MONDAY
WHICH DESPITE A SLIGHTLY COOLER MID LEVEL ATMOSPHERE...SHOULD ONCE
AGAIN KEEP THUNDERSTORMS FROM THE MOST PART GETTING STRONG OR
SEVERE. PWATS LOOK TO INCREASE SLIGHTLY...REACHING NEARLY 2 INCHES.
THE BIGGER CONCERN WITH THE THUNDERSTORMS ON MONDAY WOULD BE THE
POTENTIAL FOR EXCESSIVE RAINFALL. THERE THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS TO PRODUCE RAINFALL EXCEEDING ONE-HOUR FLASH
FLOOD GUIDANCE OF ONLY 1-2 INCHES ACROSS REGION.
WHILE IT IS TOO EARLY TO ISSUE A FLASH FLOOD WATCH WE WILL CONTINUE
TO HIGHLIGHT THIS POTENTIAL IN OUR HAZARDOUS WEATHER OUTLOOK
PRODUCT.
WITH THE CLOUDS AND EXPECTED SHOWERS AND STORMS ON
MONDAY...TEMPERATURES WILL NOT BE AS HIGH AS THEY HAVE
BEEN...TOPPING OUT 80-85 MOST VALLEY LOCATIONS...70S HIGHER TERRAIN.
HOWEVER...IT WILL CERTAINLY REMAIN VERY HUMID.
MONDAY NIGHT...LINGERING SHOWERS AND THUNDERSTORMS SHOULD DIMINISH
AS THE UPPER AIR LOW OPENS AND FLEES TO THE EAST. PARTIAL CLEARING
WILL ALLOW TEMPERATURES TO DIP A LITTLE LOWER...60 TO 65 DEGREES
MOST PLACES...WITH A FEW UPPER 50S ACROSS THE ADIRONDACK PARK.
TUESDAY...OPTIMISTICALLY LOOKS LIKE A MAINLY DRY DAY AS SLIGHTLY
DRIER AIR WORKS INTO THE REGION VIA WEAK SUBSIDENCE. STILL...DECIDED
TO ASSIGN SLIGHT POPS DURING THE AFTERNOON AS THERE WILL BE SOME
INSTABILITY AND PRESUMABLY LOTS OF LOW LEVEL MOISTURE EVAPORATING
FROM THE GROUND. SUNSHINE WILL RETURN TO HELP BOOST TEMPERATURES TO
BETWEEN 85 AND 90 DEGREES IN MOST AREAS.
IT LOOKS MAINLY DRY TUESDAY NIGHT...BUT BY WEDNESDAY...THE NEXT
DISTURBANCE IN THE NORTHERN STREAM APPROACHES...BRINGING YET ANOTHER
INCREASING THREAT IN SHOWERS AND THUNDERSTORMS. LOWS WILL GENERALLY
BE IN THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OUT WEDNESDAY WITH A WARM FRONT AND/OR PRE-FRONTAL
TROUGH APPROACHING THE AREA FROM THE GREAT LAKES AND OHIO VALLEY.
THIS SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. THE EVENTUAL INTENSITY OF T-STORMS WILL DEPEND ON THE
DEGREE OF INSTABILITY...WHICH WILL BE TIED TO CLOUD COVER. THERE
SHOULD BE DECENT FLOW ALOFT FOR MID JULY WITH A MIGRATORY SUB-1000MB
CYCLONE TRACKING EASTWARD ACROSS NEAR HUDSON BAY.
THE ASSOCIATED COLD FRONT WILL PASS THROUGH THE REGION SOMETIME
WEDNESDAY NIGHT...AND THEN BECOME NEARLY STATIONARY TO THE SOUTH OF
THE REGION THURSDAY. POPS WILL BE FORECAST TO DECREASE FROM AROUND
50 PERCENT WEDNESDAY NIGHT...TO 30 TO 40 PERCENT ON THURSDAY. ONLY
20 PERCENT POPS ARE FORECAST THURSDAY NIGHT AND DRY WEATHER FOR
FRIDAY AS THE UPPER LEVEL WAVE FORMS A CLOSED/CUTOFF LOW TO OUR
SOUTHWEST...AND FOR A BRIEF TIME DRIER AIR MOVES INTO THE REGION.
THE DRIER AIR WILL BE SHORT-LOVED AS THE UPPER LOW EVENTUALLY
INDUCES THE MOISTURE ALONG THE FRONT TO SURGE NORTHWARD AGAIN FRIDAY
NIGHT AND SATURDAY WITH A CHANCE OF SHOWERS.
AFTER WEDNESDAY...TEMPERATURES AND HUMIDITY LEVELS WILL START TO
DROP OFF SOMEWHAT AS A COOLER NORTHERLY FLOW DEVELOPS IN WAKE OF THE
COLD FRONT. HIGHS WEDNESDAY WILL BE IN THE UPPER 70S AND 80S...IN
THE MID 70S TO MID 80S THURSDAY...IN THE MID 70S TO LOWER 80S FRIDAY
AND SATURDAY. LOWS WEDNESDAY NIGHT WILL BE IN THE MID 60S TO LOWER
70S...THE UPPER 50S AND 60S THURSDAY NIGHT...AND THE MID 50S TO MID
60S FRIDAY NIGHT.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
PREDOMINATELY VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THIS
AFTERNOON MINUS ANY SHOWER/THUNDERSTORM ASSOCIATED MVFR/IFR FLYING
CONDITIONS. HAVE ONLY MENTIONED VCSH IN THE TAFS AT THIS TIME AS
COVERAGE WILL REMAIN SCATTERED AT BEST AND WILL AMEND AS NEEDED.
LATEST RADAR IMAGERY DEPICTS SCATTERED SHOWERS/THUNDERSTORMS
DEVELOPING ACROSS THE REGION AND THESE WILL PERSIST THROUGH THE
EVENING HOURS. ANY CONVECTION SHOULD DIMINISH BY MIDNIGHT WITH A
BRIEF LULL IN PRECIPITATION AHEAD OF THE NEXT APPROACHING SYSTEM.
INCREASING CLOUD COVER SHOULD LIMIT FOG POTENTIAL SOMEWHAT TONIGHT
BUT WILL CONTINUE WITH MVFR FOG FOR ALL TAF SITES EXCEPT KALB. AN
UPPER-LEVEL SHORTWAVE TROUGH AND SURFACE FRONTAL BOUNDARY WILL
APPROACH THE REGION TONIGHT AND MONDAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO THE TAF SITES TO END THE TAF PERIOD.
SURFACE WINDS WILL BECOME SOUTH OR SOUTHWEST AT 5 TO 10 KTS...THEN
BECOME LIGHT AGAIN AFTER SUNSET.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
AFTER A BRIEF BREAK IN THE ACTION ON SATURDAY...IT LOOKS AS IF
SCATTERED SHOWERS AND THUNDERSTORMS RETURN TODAY AND AGAIN TOMORROW.
SOME OF THESE ESPECIALLY ON MONDAY COULD PRODUCE LOCALLY HEAVY
RAINFALL. TUESDAY LOOKS DRIER BUT THEN MORE SHOWERS COULD TAKE PLACE
ON WEDNESDAY.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER AIR LOW
PRESSURE SYSTEM. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES...ESPECIALLY ON MONDAY.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/NAS
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...IRL
FIRE WEATHER...HWJIV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
122 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST THROUGH THIS AFTERNOON. THIS WILL ALLOW MOISTURE TO
MOVE BACK INTO THE REGION...INCREASING THE RISK OF SHOWERS AND
THUNDERSTORMS. TONIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE
WILL MOVE BACK INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER
UNSETTLED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE DEVELOPING WITH QUITE A BIT OF
INSTABILITY OVER THE REGION. FREEZING LEVELS ADN -20C LEVELS QUITE
HIGH...BUT THERE COULD BE A STORM OR TWO THAT COULD PRODUCE SOME
STRONG GUSTY WINDS...AND HEAVY RAIN IS ALWAYS A THREAT WITH
LOCALIZED FLASH FLOODING. JUST SOME MINOR ADJUSTMENTS TO THE
TEMPERATURES AND RAIN CHANCES THROUGH THIS AFTERNOON.
THE LOCAL WRF AND HRRR SUGGEST AN ACTIVE AFTERNOON AND EVENING
ACROSS THE REGION.
HEAT INDICES IN THE MID HUDSON VALLEY AND NW CT WILL TOUCH 100 AT
TIMES THIS AFTERNOON BUT NOT WIDESPREAD ENOUGH OR LONG ENOUGH
DURATION FOR A SHORT FUSE HEAT ADVISORY. HEAT INDICES HAVE BEEN
NEAR 100 THE PAST COUPLE OF AFTERNOONS AND HEAT INDICES A DEGREE
OR TWO WARMER THIS AFTERNOON SHOULD FEEL NEARLY THE SAME AS THE
PAST COUPLE OF AFTERNOONS.
PREVIOUS DISCUSSION DESCRIBES THE FACTORS AFFECTING CONVECTION
THIS AFTERNOON AND EVENING AND IS BELOW..
QUITE AN INSTABILITY GRADIENT HAS ALREADY SET UP ACROSS THE
AREA...SINCE LOCATIONS TO THE SOUTH OF ALBANY DID NOT HAVE ANY
CLOUDS/SHOWERS MOVE THROUGH EARLIER AND INSTEAD HAD SUNSHINE.
COMBINED WITH A RETURN IN LOW LEVEL MOISTURE...THIS HAS ALLOW
SBCAPE VALUES TO SURGE IN TO THE 2000-3000 J/KG RANGE LATE THIS
MORNING. TO THE NORTH A RATHER SHARP INSTABILITY GRADIENT NOW
EXISTS...ALTHOUGH IT WILL BECOME SOMEWHAT MORE UNIFORM BY EARLY
AFTERNOON DUE TO PARTIAL SUNSHINE HEATING THIS AREA AS WELL.
HOWEVER...THE INSTABILITY GRADIENT AND DIFFERENTIAL HEATING THAT
OCCURRED MAY RESULT IN AN AREA TO WATCH FOR ENHANCED CONVECTION BY
EARLY TO MID AFTERNOON. ANOTHER SOURCE OF ASCENT COULD BE A
SUBTLE IMPULSE MOVING NORTHEASTWARD FROM THE UPPER LOW OVER THE
OHIO VALLEY...THAT COULD TRACK THROUGH PA/NY THIS AFTERNOON AND
EVENING. SO KEPT MENTION OF SCATTERED THUNDERSTORMS WITH
RELATIVELY HIGH POPS OF 5O PERCENT. MESOSCALE MODELS SHOWING
CONVECTION INITIATING ACROSS MUCH OF THE AREA THIS AFTERNOON...AND
SOME STORMS COULD BE STRONG BASED ON HOW TALL UPDRAFTS ARE ABLE
TO GET.
DEEP LAYER SHEAR AROUND 25-35 KT IS SUFFICIENT FOR STORM
ORGANIZATION...ALTHOUGH ONCE AGAIN MID LEVEL LAPSE RATES REMAIN
RATHER MARGINAL AROUND 6.0 C/KM AND HIGH FREEZING LEVELS OVER 14
KFT. WITH MODERATE TO HIGH LEVELS OF INSTABILITY...WILL HAVE TO
WATCH FOR WET MICROBURST POTENTIAL AND ONCE AGAIN HEAVY RAIN AND
POSSIBLE ISOLATED FLASH FLOODING WITH THE STRONGER AND SLOW MOVING
T-STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
WHILE THE AFOREMENTIONED DISTURBANCES WILL MOVE ON BY THIS
EVENING...THE ACTUAL UPPER AIR LOW LOOKS TO MOVE OUR WAY LATE
TONIGHT INTO MONDAY. THIS WILL SERVE TO COOL THE ATMOSPHERE A LITTLE
BUT THE WIND FIELD (BULK SHEAR) LOOKS WEAK. SHOWERS AND STORMS LOOK
TO DIMINISH IN AREA DURING THE EVENING...BUT COULD REKINDLE LATER
OVERNIGHT INTO EARLY MONDAY. LOWS OVERNIGHT WILL BE MUGGY...65 TO 70
DEGREES.
WE EXPECT PLENTY OF CLOUDS AROUND WITH THIS FEATURE INTO MONDAY
WHICH DESPITE A SLIGHTLY COOLER MID LEVEL ATMOSPHERE...SHOULD ONCE
AGAIN KEEP THUNDERSTORMS FROM THE MOST PART GETTING STRONG OR
SEVERE. PWATS LOOK TO INCREASE SLIGHTLY...REACHING NEARLY 2 INCHES.
THE BIGGER CONCERN WITH THE THUNDERSTORMS ON MONDAY WOULD BE THE
POTENTIAL FOR EXCESSIVE RAINFALL. THERE THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS TO PRODUCE RAINFALL EXCEEDING ONE-HOUR FLASH
FLOOD GUIDANCE OF ONLY 1-2 INCHES ACROSS REGION.
WHILE IT IS TOO EARLY TO ISSUE A FLASH FLOOD WATCH WE WILL CONTINUE
TO HIGHLIGHT THIS POTENTIAL IN OUR HAZARDOUS WEATHER OUTLOOK
PRODUCT.
WITH THE CLOUDS AND EXPECTED SHOWERS AND STORMS ON
MONDAY...TEMPERATURES WILL NOT BE AS HIGH AS THEY HAVE
BEEN...TOPPING OUT 80-85 MOST VALLEY LOCATIONS...70S HIGHER TERRAIN.
HOWEVER...IT WILL CERTAINLY REMAIN VERY HUMID.
MONDAY NIGHT...LINGERING SHOWERS AND THUNDERSTORMS SHOULD DIMINISH
AS THE UPPER AIR LOW OPENS AND FLEES TO THE EAST. PARTIAL CLEARING
WILL ALLOW TEMPERATURES TO DIP A LITTLE LOWER...60 TO 65 DEGREES
MOST PLACES...WITH A FEW UPPER 50S ACROSS THE ADIRONDACK PARK.
TUESDAY...OPTIMISTICALLY LOOKS LIKE A MAINLY DRY DAY AS SLIGHTLY
DRIER AIR WORKS INTO THE REGION VIA WEAK SUBSIDENCE. STILL...DECIDED
TO ASSIGN SLIGHT POPS DURING THE AFTERNOON AS THERE WILL BE SOME
INSTABILITY AND PRESUMABLY LOTS OF LOW LEVEL MOISTURE EVAPORATING
FROM THE GROUND. SUNSHINE WILL RETURN TO HELP BOOST TEMPERATURES TO
BETWEEN 85 AND 90 DEGREES IN MOST AREAS.
IT LOOKS MAINLY DRY TUESDAY NIGHT...BUT BY WEDNESDAY...THE NEXT
DISTURBANCE IN THE NORTHERN STREAM APPROACHES...BRINGING YET ANOTHER
INCREASING THREAT IN SHOWERS AND THUNDERSTORMS. LOWS WILL GENERALLY
BE IN THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE PERIOD STARTS OUT WEDNESDAY WITH A WARM FRONT AND/OR PRE-FRONTAL
TROUGH APPROACHING THE AREA FROM THE GREAT LAKES AND OHIO VALLEY.
THIS SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. THE EVENTUAL INTENSITY OF T-STORMS WILL DEPEND ON THE
DEGREE OF INSTABILITY...WHICH WILL BE TIED TO CLOUD COVER. THERE
SHOULD BE DECENT FLOW ALOFT FOR MID JULY WITH A MIGRATORY SUB-1000MB
CYCLONE TRACKING EASTWARD ACROSS NEAR HUDSON BAY.
THE ASSOCIATED COLD FRONT WILL PASS THROUGH THE REGION SOMETIME
WEDNESDAY NIGHT...AND THEN BECOME NEARLY STATIONARY TO THE SOUTH OF
THE REGION THURSDAY. POPS WILL BE FORECAST TO DECREASE FROM AROUND
50 PERCENT WEDNESDAY NIGHT...TO 30 TO 40 PERCENT ON THURSDAY. ONLY
20 PERCENT POPS ARE FORECAST THURSDAY NIGHT AND DRY WEATHER FOR
FRIDAY AS THE UPPER LEVEL WAVE FORMS A CLOSED/CUTOFF LOW TO OUR
SOUTHWEST...AND FOR A BRIEF TIME DRIER AIR MOVES INTO THE REGION.
THE DRIER AIR WILL BE SHORT-LOVED AS THE UPPER LOW EVENTUALLY
INDUCES THE MOISTURE ALONG THE FRONT TO SURGE NORTHWARD AGAIN FRIDAY
NIGHT AND SATURDAY WITH A CHANCE OF SHOWERS.
AFTER WEDNESDAY...TEMPERATURES AND HUMIDITY LEVELS WILL START TO
DROP OFF SOMEWHAT AS A COOLER NORTHERLY FLOW DEVELOPS IN WAKE OF THE
COLD FRONT. HIGHS WEDNESDAY WILL BE IN THE UPPER 70S AND 80S...IN
THE MID 70S TO MID 80S THURSDAY...IN THE MID 70S TO LOWER 80S FRIDAY
AND SATURDAY. LOWS WEDNESDAY NIGHT WILL BE IN THE MID 60S TO LOWER
70S...THE UPPER 50S AND 60S THURSDAY NIGHT...AND THE MID 50S TO MID
60S FRIDAY NIGHT.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
PREDOMINATELY VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THIS
AFTERNOON MINUS ANY SHOWER/THUNDERSTORM ASSOCIATED MVFR/IFR FLYING
CONDITIONS. HAVE ONLY MENTIONED VCSH IN THE TAFS AT THIS TIME AS
COVERAGE WILL REMAIN SCATTERED AT BEST AND WILL AMEND AS NEEDED.
LATEST RADAR IMAGERY DEPICTS SCATTERED SHOWERS/THUNDERSTORMS
DEVELOPING ACROSS THE REGION AND THESE WILL PERSIST THROUGH THE
EVENING HOURS. ANY CONVECTION SHOULD DIMINISH BY MIDNIGHT WITH A
BRIEF LULL IN PRECIPITATION AHEAD OF THE NEXT APPROACHING SYSTEM.
INCREASING CLOUD COVER SHOULD LIMIT FOG POTENTIAL SOMEWHAT TONIGHT
BUT WILL CONTINUE WITH MVFR FOG FOR ALL TAF SITES EXCEPT KALB. AN
UPPER-LEVEL SHORTWAVE TROUGH AND SURFACE FRONTAL BOUNDARY WILL
APPROACH THE REGION TONIGHT AND MONDAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TO THE TAF SITES TO END THE TAF PERIOD.
SURFACE WINDS WILL BECOME SOUTH OR SOUTHWEST AT 5 TO 10 KTS...THEN
BECOME LIGHT AGAIN AFTER SUNSET.
OUTLOOK...
TUE...MAINLY VFR. SCT -SHRA/-TSRA.
WED...VFR/MVFR/IFR DUE TO SCT TO NUM -SHRA/-TSRA.
THU-FRI...MAINLY VFR. SCT PM -SHRA/-TSRA.
MVFR/IFR OVERNIGHT FOG POSSIBLE TUE-FRI.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
AFTER A BRIEF BREAK IN THE ACTION ON SATURDAY...IT LOOKS AS IF
SCATTERED SHOWERS AND THUNDERSTORMS RETURN TODAY AND AGAIN TOMORROW.
SOME OF THESE ESPECIALLY ON MONDAY COULD PRODUCE LOCALLY HEAVY
RAINFALL. TUESDAY LOOKS DRIER BUT THEN MORE SHOWERS COULD TAKE PLACE
ON WEDNESDAY.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY WITH THE APPROACH OF A WEAK COLD FRONT AND UPPER AIR LOW
PRESSURE SYSTEM. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES...ESPECIALLY ON MONDAY.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/NAS
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...IRL
FIRE WEATHER...HWJIV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
210 AM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST TODAY. THIS WILL ALLOW MOISTURE TO MOVE BACK INTO THE
REGION ON SUNDAY...INCREASING THE RISK OF SHOWERS AND THUNDERSTORMS.
SUNDAY NIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE WILL MOVE BACK
INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER UNSETTLED.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1240 PM EDT...ALL STILL QUITE ON OUR RADAR. A MOSTLY CLEAR SKY
ALLOWING TEMPERATURES TO FALL A LITTLE DOWN INTO THE 70S IN THE
URBAN AREAS...60S OUTLYING REGION. NO FOG YET...BUT WITH
TEMPERATURES CLOSING TOWARD THE DEWPOINT IN SOME CASES...SOME PATCHY
FOG LOOKS LIKELY TOWARD DAYBREAK.
THERE ARE A FEW SHOWERS UPSTREAM ACROSS SOUTH CENTRAL NEW YORK
STATE...SLOWLY HEADING THIS WAY. ONE OF OUR EXPERIMENTAL NEAR TERM
MODELS THE HRRR INDICATED THESE WOULD COME INTO THE OUR REGION
BEFORE SUNRISE...PASSING THE CAPITAL REGION AFTER 800 AM AS HEAVY
SHOWERS POSSIBLY EVEN A THUNDERSTORM.
NOT SEEING IT THOUGH AS INSTABILITY IS LIMITED FROM THE CAPITAL
REGION NORTHWARD...ALTHOUGH SOME REMAINS TO OUR SOUTH (UP TO 1000
J/KG OFF THE LAPS). WITH HIGH PRESSURE IN PLACE...BELIEVE THE
SHOWERS WILL INITIALLY HAVE A HARD TIME HEADING OUR WAY...AT LEAST
THROUGH THE OVERNIGHT.
WILL KEEP POPS BELOW 15 PERCENT...ESSENTIALLY DRY. HOWEVER...WILL
CONTINUE TO INTRODUCE SLIGHT POPS AFTER SUNRISE AND SPREAD THEM
EASTWARD WITH TIME.
UPDATED TEMPS/DEW POINTS/CLOUDS TO REFLECT CURRENT OBS.
OTHERWISE...NO ADDITIONAL CHANGES.
WITH THE LIGHT WINDS AND HUMIDITY...TEMPERATURES SHOULD NOT COOL
OFF TOO MUCH FROM HOT EVENING TEMPERATURES DUE TO THE SHORT NIGHTS
THIS TIME OF YEAR...EVEN WITH THE PARTLY CLOUDY TO CLEAR SKY. SOME
PATCHY FOG IS ALSO POSSIBLE IN SOME AREAS. LOWS SHOULD BE IN THE
60S TO AROUND 70...WHICH IS A LITTLE COOLER THAN LAST NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
UPPER ENERGY IN THE MIDWEST AND OH VALLEY SHOULD MOVE STEADILY
EAST AND THERE IS A GOOD CONSENSUS THAT ONE UPPER IMPULSE AT THE
LEADING EDGE OF THIS UPPER ENERGY SHOULD TRACK ACROSS THE REGION
TOMORROW AFTERNOON. THIS UPPER ENERGY SHOULD SUPPORT BETTER
COVERAGE OF SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON AND
EVENING OVER EASTERN NY INTO THE NORTHERN BERKSHIRES AND SOUTHERN
VT. ACTIVITY COULD BE LIMITED IN THE MID HUDSON VALLEY AND NW CT
SINCE THE UPPER ENERGY IS PREDICTED TO TRACK THROUGH MAINLY
NORTHERN AND CENTRAL AREAS. HIGHS SUNDAY IN THE 80S TO LOWER
90S...WITH THE WARMEST TEMPERATURES IN THE MID HUDSON VALLEY AND
NW CT.
THE MAIN CENTER OF THE UPPER ENERGY TRACKS JUST SOUTH OF THE
REGION MONDAY AND MONDAY AFTERNOON...BUT LOW LEVEL FORCING WITH A
LITTLE BIT OF COOLING AT THE BOUNDARY LAYER AND THE UPPER DYNAMICS
SHOULD SUPPORT INCREASED COVERAGE OF CLOUDS...SHOWERS AND
THUNDERSTORMS. HIGHS MONDAY SHOULD BE IN THE MID 80S...NEAR 80 IN
THE SOUTHERN ADIRONDACKS AND UPPER 80S MID HUDSON VALLEY AND NW
CT. LOCALLY HEAVY RAIN BOTH SUNDAY AND MONDAY COULD RESULT IN
LOCALIZED FLASH FLOODING AND A WATCH COULD BE CONSIDERED OVERNIGHT
OR TOMORROW DEPENDING ON HOW MUCH COVERAGE OF SHOWERS AND
THUNDERSTORMS COULD BE EXPECTED...SO STAY TUNED.
THERE ARE INDICATIONS THAT THE UPPER ENERGY AND WEAK COLD FRONT
EXIT THE REGION MONDAY NIGHT...WITH SOME POTENTIAL PARTIAL
CLEARING OUTSIDE OF AREAS OF FOG BY EARLY TUESDAY MORNING. LOWS
SHOULD BE IN THE 60S...WITH MAYBE SOME MID TO UPPER 50S IN THE
SOUTHERN ADIRONDACKS. ON TUESDAY...SOME WEAK UPPER RIDGING SHOULD
BE OVER THE REGION...BUT THE ATMOSPHERE SHOULD STILL BE UNSTABLE...
EVEN WITH NO REAL ORGANIZED LOW LEVEL FOCUS. SO...THERE COULD BE
ISOLATED SHOWERS AND THUNDERSTORMS IN THE SOUTHERN HALF OF THE
FORECAST AREA WITH HIGHS IN THE 80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE PERIOD STARTS OUT LATE TUESDAY NIGHT INTO WEDNESDAY WITH A WARM
FRONT AND/OR PRE-FRONTAL TROUGH APPROACHING THE AREA FROM THE GREAT
LAKES AND OHIO VALLEY. THIS SYSTEM WILL BRING ADDITIONAL CHANCES FOR
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS. THE EVENTUAL INTENSITY
OF T-STORMS WILL DEPEND ON THE DEGREE OF INSTABILITY...WHICH WILL BE
TIED TO CLOUD COVER. THERE SHOULD BE DECENT FLOW ALOFT FOR MID JULY
WITH A MIGRATORY SUB-1000MB CYCLONE TRACKING EASTWARD NEAR HUDSON
BAY.
THE FIRST SERIES OF FRONTAL BOUNDARY WILL PASS THROUGH BY SOMETIME
LATE WEDNESDAY OR WEDNESDAY NIGHT...WHILE THE MAIN COLD FRONT IS
FORECAST TO SAG SOUTHWARD ACROSS THE AREA LATE WEDNESDAY NIGHT INTO
THURSDAY. WILL CONTINUE TO MENTION CHANCE POPS DURING THIS
TIME...WITH THE POSSIBLY MORE ROBUST CONVECTION OCCURRING ON
WEDNESDAY. THERE COULD BE AN ADDITIONAL ROUND OF T-STORMS SOUTH OF
ALBANY ON THURSDAY IF THE FRONT SLOWS ENOUGH...WHICH IS BEING
DEPICTED BY THE 12Z GFS AND ECMWF.
IT AT LEAST LOOKS LIKE TEMPERATURES AND HUMIDITY LEVELS WILL START
TO SOMEWHAT DROP BY WEEK`S END AS A COOLER NORTHERLY FLOW DEVELOPS
IN WAKE OF THE COLD FRONT. HOWEVER...THE CHAOTIC UPPER LEVEL PATTERN
MAY ALLOW FOR A CUT-OFF LOW TO FORM SOMEWHAT IN THE VICINITY OF THE
OHIO VALLEY...MID ATLANTIC...OR SOUTHERN APPALACHIANS REGION WHICH
COULD RESULT IN A MOIST SOUTHERLY FLOW QUICKLY RETURNING BY THE
WEEKEND ALONG WITH RENEWED CHANCES FOR PRECIP AND INCREASING
HUMIDITY.
THERE STILL CONSIDERABLE UNCERTAINTY IN HOW THE PATTERN WILL
EVENTUALLY UNFOLD...BUT BOTH THE GFS AND ECMWF ARE DEPICTING A
CUT-OFF LOW FORMING SOUTH AND WEST OF OUR AREA NEXT WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z KGFL/KPOU HAD ALREADY HAD OCCASIONAL IFR VSBYS DUE TO
FOG...WHILE NO FOG HAD BEEN REPORTED AT KALB/KPSF. STLT PICS SHOW A
WIDESPREAD CLOUD DECK (GENERALLY MID/HI CLOUDS) MOVING OVER THE TAF
SITES AS OF 06Z AND WOULD EXPECT THIS CLOUD DECK TO INHIBIT FOG
FORMATION IF FOG HAD NOT LREADY FORMED BEFORE IT ARRIVES. WILL
CONTINUE TO FORECAST OCNL IFR FOG AT KGFL/KPOU THROUGH 11Z...BUT
FORECAST NO FOG AT KALB AND ONLY OCCASIONAL MVFR FOG AT KPSF.
THERE ARE SCT TO NUMEROUS SHWRS/TSTMS OVER FAR WESTERN NEW YORK AS
OF 06Z...WITH ISOLATED SHOWERS FURTHER EAST. THESE SHOWERS ARE
ASSOCIATED WITH AN APPROACHING UPPER LEVEL TROF. WOULD NOT EXPECT
THESE SHOWERS TO BE NEAR THE TAF SITES BEFORE MID OR LATE SUNDAY
MORNING. MODEL FORECASTS AND OBSERVED MOVEMENT OF THESE SHWRS/TSTMS
WOULD SUGGEST THE BULK OF THEM WILL PASS TO THE NORTH AND WEST OF
THE TAF SITES. AS A RESULT...WILL FORECAST NO MORE THAN VCSH IN THE
TAFS FROM LATE THIS MORNING THROUGH THE END OF THE TAF PERIOD AT 06Z
MONDAY. ALSO...EXCEPT FOR THE EARLY MORNING FOG CONDITIONS...HAVE
FORECAST VFR CONDITIONS AT THE TAF SITES THROUGH THE END OF THE TAF
PERIOD.
SURFACE WIND WILL GENERALLY BE CALM THROUGH 2 TO 3 HOURS AFTER
SUNRISE...THEN BECOME SOUTH OR SOUTHWEST AT 5 TO 10 KTS...THEN
BECOME LIGHT AGAIN AFTER SUNSET ON SUNDAY.
OUTLOOK...
LATE SUN NITE-TUE...MAINLY VFR. SCT MAINLY AFTERNOON AND EVENING
SHRA/TSRA. POSSIBLE LATE NIGHT AND/OR EARLY MORNING FOG/LOW STRATUS
WITH MVFR/IFR POSSIBLE.
WED...VFR/MVFR/IFR DUE TO SCT TO NUMEROUS SHRA/TSRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
FUELS CONTINUE TO REMAIN SATURATED FROM RECENT SHOWER/THUNDERSTORM
ACTIVITY. THERE WILL CONTINUE TO BE A CHANCE FOR AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS FOR THE NEXT SEVERAL DAYS AS THE BERMUDA
HIGH KEEPS A HOT AND HUMID AIR MASS ENTRENCHED OVER THE REGION.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE COULD BE SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY
AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY AFTERNOON AND EVENING WITH THE APPROACH OF A WEAK COLD
FRONT. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/OKEEFE
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...GJM
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1237 AM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL BEGIN TO WEAKEN AND MOVE A LITTLE FURTHER
SOUTHEAST TODAY. THIS WILL ALLOW MOISTURE TO MOVE BACK INTO THE
REGION ON SUNDAY...INCREASING THE RISK OF SHOWERS AND THUNDERSTORMS.
SUNDAY NIGHT INTO MONDAY...AN UPPER LEVEL DISTURBANCE WILL MOVE BACK
INTO FROM THE OHIO VALLEY...KEEPING OUR WEATHER UNSETTLED.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1240 PM EDT...ALL STILL QUITE ON OUR RADAR. A MOSTLY CLEAR SKY
ALLOWING TEMPERATURES TO FALL A LITTLE DOWN INTO THE 70S IN THE
URBAN AREAS...60S OUTLYING REGION. NO FOG YET...BUT WITH
TEMPERATURES CLOSING TOWARD THE DEWPOINT IN SOME CASES...SOME PATCHY
FOG LOOKS LIKELY TOWARD DAYBREAK.
THERE ARE A FEW SHOWERS UPSTREAM ACROSS SOUTH CENTRAL NEW YORK
STATE...SLOWLY HEADING THIS WAY. ONE OF OUR EXPERIMENTAL NEAR TERM
MODELS THE HRRR INDICATED THESE WOULD COME INTO THE OUR REGION
BEFORE SUNRISE...PASSING THE CAPITAL REGION AFTER 800 AM AS HEAVY
SHOWERS POSSIBLY EVEN A THUNDERSTORM.
NOT SEEING IT THOUGH AS INSTABILITY IS LIMITED FROM THE CAPITAL
REGION NORTHWARD...ALTHOUGH SOME REMAINS TO OUR SOUTH (UP TO 1000
J/KG OFF THE LAPS). WITH HIGH PRESSURE IN PLACE...BELIEVE THE
SHOWERS WILL INITIALLY HAVE A HARD TIME HEADING OUR WAY...AT LEAST
THROUGH THE OVERNIGHT.
WILL KEEP POPS BELOW 15 PERCENT...ESSENTIALLY DRY. HOWEVER...WILL
CONTINUE TO INTRODUCE SLIGHT POPS AFTER SUNRISE AND SPREAD THEM
EASTWARD WITH TIME.
UPDATED TEMPS/DEW POINTS/CLOUDS TO REFLECT CURRENT OBS.
OTHERWISE...NO ADDITIONAL CHANGES.
WITH THE LIGHT WINDS AND HUMIDITY...TEMPERATURES SHOULD NOT COOL
OFF TOO MUCH FROM HOT EVENING TEMPERATURES DUE TO THE SHORT NIGHTS
THIS TIME OF YEAR...EVEN WITH THE PARTLY CLOUDY TO CLEAR SKY. SOME
PATCHY FOG IS ALSO POSSIBLE IN SOME AREAS. LOWS SHOULD BE IN THE
60S TO AROUND 70...WHICH IS A LITTLE COOLER THAN LAST NIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
UPPER ENERGY IN THE MIDWEST AND OH VALLEY SHOULD MOVE STEADILY
EAST AND THERE IS A GOOD CONSENSUS THAT ONE UPPER IMPULSE AT THE
LEADING EDGE OF THIS UPPER ENERGY SHOULD TRACK ACROSS THE REGION
TOMORROW AFTERNOON. THIS UPPER ENERGY SHOULD SUPPORT BETTER
COVERAGE OF SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON AND
EVENING OVER EASTERN NY INTO THE NORTHERN BERKSHIRES AND SOUTHERN
VT. ACTIVITY COULD BE LIMITED IN THE MID HUDSON VALLEY AND NW CT
SINCE THE UPPER ENERGY IS PREDICTED TO TRACK THROUGH MAINLY
NORTHERN AND CENTRAL AREAS. HIGHS SUNDAY IN THE 80S TO LOWER
90S...WITH THE WARMEST TEMPERATURES IN THE MID HUDSON VALLEY AND
NW CT.
THE MAIN CENTER OF THE UPPER ENERGY TRACKS JUST SOUTH OF THE
REGION MONDAY AND MONDAY AFTERNOON...BUT LOW LEVEL FORCING WITH A
LITTLE BIT OF COOLING AT THE BOUNDARY LAYER AND THE UPPER DYNAMICS
SHOULD SUPPORT INCREASED COVERAGE OF CLOUDS...SHOWERS AND
THUNDERSTORMS. HIGHS MONDAY SHOULD BE IN THE MID 80S...NEAR 80 IN
THE SOUTHERN ADIRONDACKS AND UPPER 80S MID HUDSON VALLEY AND NW
CT. LOCALLY HEAVY RAIN BOTH SUNDAY AND MONDAY COULD RESULT IN
LOCALIZED FLASH FLOODING AND A WATCH COULD BE CONSIDERED OVERNIGHT
OR TOMORROW DEPENDING ON HOW MUCH COVERAGE OF SHOWERS AND
THUNDERSTORMS COULD BE EXPECTED...SO STAY TUNED.
THERE ARE INDICATIONS THAT THE UPPER ENERGY AND WEAK COLD FRONT
EXIT THE REGION MONDAY NIGHT...WITH SOME POTENTIAL PARTIAL
CLEARING OUTSIDE OF AREAS OF FOG BY EARLY TUESDAY MORNING. LOWS
SHOULD BE IN THE 60S...WITH MAYBE SOME MID TO UPPER 50S IN THE
SOUTHERN ADIRONDACKS. ON TUESDAY...SOME WEAK UPPER RIDGING SHOULD
BE OVER THE REGION...BUT THE ATMOSPHERE SHOULD STILL BE UNSTABLE...
EVEN WITH NO REAL ORGANIZED LOW LEVEL FOCUS. SO...THERE COULD BE
ISOLATED SHOWERS AND THUNDERSTORMS IN THE SOUTHERN HALF OF THE
FORECAST AREA WITH HIGHS IN THE 80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE PERIOD STARTS OUT LATE TUESDAY NIGHT INTO WEDNESDAY WITH A WARM
FRONT AND/OR PRE-FRONTAL TROUGH APPROACHING THE AREA FROM THE GREAT
LAKES AND OHIO VALLEY. THIS SYSTEM WILL BRING ADDITIONAL CHANCES FOR
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS. THE EVENTUAL INTENSITY
OF T-STORMS WILL DEPEND ON THE DEGREE OF INSTABILITY...WHICH WILL BE
TIED TO CLOUD COVER. THERE SHOULD BE DECENT FLOW ALOFT FOR MID JULY
WITH A MIGRATORY SUB-1000MB CYCLONE TRACKING EASTWARD NEAR HUDSON
BAY.
THE FIRST SERIES OF FRONTAL BOUNDARY WILL PASS THROUGH BY SOMETIME
LATE WEDNESDAY OR WEDNESDAY NIGHT...WHILE THE MAIN COLD FRONT IS
FORECAST TO SAG SOUTHWARD ACROSS THE AREA LATE WEDNESDAY NIGHT INTO
THURSDAY. WILL CONTINUE TO MENTION CHANCE POPS DURING THIS
TIME...WITH THE POSSIBLY MORE ROBUST CONVECTION OCCURRING ON
WEDNESDAY. THERE COULD BE AN ADDITIONAL ROUND OF T-STORMS SOUTH OF
ALBANY ON THURSDAY IF THE FRONT SLOWS ENOUGH...WHICH IS BEING
DEPICTED BY THE 12Z GFS AND ECMWF.
IT AT LEAST LOOKS LIKE TEMPERATURES AND HUMIDITY LEVELS WILL START
TO SOMEWHAT DROP BY WEEK`S END AS A COOLER NORTHERLY FLOW DEVELOPS
IN WAKE OF THE COLD FRONT. HOWEVER...THE CHAOTIC UPPER LEVEL PATTERN
MAY ALLOW FOR A CUT-OFF LOW TO FORM SOMEWHAT IN THE VICINITY OF THE
OHIO VALLEY...MID ATLANTIC...OR SOUTHERN APPALACHIANS REGION WHICH
COULD RESULT IN A MOIST SOUTHERLY FLOW QUICKLY RETURNING BY THE
WEEKEND ALONG WITH RENEWED CHANCES FOR PRECIP AND INCREASING
HUMIDITY.
THERE STILL CONSIDERABLE UNCERTAINTY IN HOW THE PATTERN WILL
EVENTUALLY UNFOLD...BUT BOTH THE GFS AND ECMWF ARE DEPICTING A
CUT-OFF LOW FORMING SOUTH AND WEST OF OUR AREA NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
ANTICIPATING MAINLY VFR CONDITIONS THROUGH THE FORECAST PERIOD.
SOME SHRA /NO TSRA OBSERVED YET/ ACTIVITY TRACKING ALONG NY/PA
BORDER NEAR AND SOUTH OF BGM. DONT EXPECT THIS TO SURVIVE TO KPOU.
NOT CLEAR IF THE USUAL TROUBLE SPOTS OF KPSF AND KGFL WILL SLIDE
INTO IFR CONDITIONS OVERNIGHT. DRIER AIR IN EVIDENCE AT THOSE
TERMINALS TODAY WITH DEW POINTS INTO MID 60S. FOR NOW...WILL
CONTINUE WITH IDEA OF MVFR BR THERE. AT KPOU AND KALB...VFR
CONDITIONS.
TOMORROW...HAVE INCLUDED /VCSH/ FOR THE AFTERNOON AT ALL TERMINAL
EX KPOU. BETTER ORGANIZED SYSTEM WILL BE MOVING ACROSS NORTHERN
PORTION OF THE REGION. TIMING...INTENSITY... DURATION...NOT CLEAR
AT THIS POINT. SO VCSH WILL SUFFICE. HAVE NOT INCLUDED VCSH AT
KPOU. AS NOTED...BETTER CHANCES TO THE NORTH. ALSO COULD SEE SOME
TSRA AT TERMINALS...BUT AGAIN LIKELIHOOD/TIMING NOT APPARENT
ENOUGH TO INCLUDE IN THE TAFS THIS FAR OUT.
OUTLOOK...
SUN NITE-TUE...MAINLY VFR. SCT MAINLY AFTERNOON AND EVENING
SHRA/TSRA. POSSIBLE LATE NIGHT AND/OR EARLY MORNING FOG/LOW
STRATUS WITH MVFR/IFR POSSIBLE.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED OVER THE NEXT SEVERAL DAYS.
FUELS CONTINUE TO REMAIN SATURATED FROM RECENT SHOWER/THUNDERSTORM
ACTIVITY. THERE WILL CONTINUE TO BE A CHANCE FOR AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS FOR THE NEXT SEVERAL DAYS AS THE BERMUDA
HIGH KEEPS A HOT AND HUMID AIR MASS ENTRENCHED OVER THE REGION.
NORMAL RH RECOVERIES EACH NIGHT BETWEEN 80 TO 100 PERCENT WILL ALLOW
FOR WIDESPREAD DEW FORMATION. DAYTIME RH VALUES WILL GENERALLY BE IN
THE 40 TO 60 PERCENT RANGE.
&&
.HYDROLOGY...
THE MOHAWK RIVER AT UTICA CONTINUES TO EXPERIENCE MINOR FLOODING.
THE RIVER AND CREEK FLOWS NEAR THE WEST CENTRAL MOHAWK RIVER ARE
EXPECTED TO GRADUALLY RECEDE INTO THE WEEKEND...UNLESS ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OCCUR OVER OR NEAR THE BASIN.
THERE COULD BE SCATTERED SHOWERS AND THUNDERSTORMS SUNDAY
AFTERNOON AND EVEN MORE COVERAGE OF SHOWERS AND THUNDERSTORMS
MONDAY AFTERNOON AND EVENING WITH THE APPROACH OF A WEAK COLD
FRONT. A MOIST AND HUMID AIR MASS WILL ALLOW ANY SHOWER OR
THUNDERSTORM TO BE CAPABLE OF PRODUCING LOCALLY HEAVY
DOWNPOURS...AND A QUICK INCH OR MORE OF RAINFALL DUE TO THE
ANOMALOUS PRECIPITABLE WATER VALUES.
THERE WILL BE A CONTINUED THREAT FOR ISOLATED FLASH FLOODING...AS
WELL AS FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. NO FLASH
FLOOD WATCHES ARE BEING ISSUED DUE TO THE EXPECTED ISOLATED NATURE
OF ANY FLOODING. IT IS ALSO DIFFICULT TO DETERMINE WHERE THE
HEAVIEST RAINFALL WILL OCCUR.
WHILE ADDITIONAL FLOODING IS NOT ANTICIPATED ON ANY MAIN STEM RIVER
POINTS...LOCALLY SHARP RISES ARE POSSIBLE DUE TO ANY CONVECTION THAT
MAY OCCUR OVER THE NEXT SEVERAL DAYS...ESPECIALLY FOR THOSE POINTS
THAT ARE MORE FLASHIER IN NATURE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV/OKEEFE
SHORT TERM...NAS
LONG TERM...JPV
AVIATION...OKEEFE
FIRE WEATHER...NAS
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
641 AM EDT Sun Jul 7 2013
...UPDATED FOR HYDROLOGY SECTION...
.NEAR TERM [Today]...
Showers and isold tstms assocd with meeting of Gulf and east coast
seabreezes across Ern most counties late Sat eve weakened after
midnight. HRRR overforecast predawn precipitation over Wrn waters
and adjacent coastlines. Updated overnight grids to reflect this.
The large scale longwave blocking pattern continues to deamplify.
This is highlighted by a ridge over Wrn half of Conus, and a lifting
trough over Cntrl and Ern states with base over TN Valley and upper
low spinning from Mid Ms Valley into OH Valley. Looking east, a
ridge extends from high in Wrn Atlc a few hundred miles east of
Carolina coast WSW down South Atlc seaboard. Looking southeast, TUTT
low spinning invcnty of Bahamas. At the surface, Sly flow around Wrn
Atlc Bermuda high will remain over SE region.
During the rest of today, expect further lifting of low which will
reach Srn Great Lakes around sundown. This will allow Atlc high to
nose Swwd and deep layer ridge to encroach further inland pushing
tropical plume responsible for recent heavy rains further west of
our area. It will also combine with Wwd movement of TUTT placing CWA
closer to its subsident side. By this eve, TUTT actually moves under
ridge shifitng it back a little ewd. Lifting trough will also help
flatten Wrn and Atlc ridges and allow them to begin to bridge under
trough. However surface ridge axis remains to our north so ample low
level moisture remains. All this translates to increasing and strong
upper subsidence and dry air overspreading from the Atlc Swwd and
Nwwd to across local area. This reflected in model soundings which
show sharp W-E increase in mid level dry air and in decreasing PWAT.
i.e. GFS at 00z Mon with 1.79 in and 1.35 inches at TLH and JAX
respectively.
Thus scenario shifting somewhat to a more typical summertime pattern
of diurnal sea breeze convection especially east of the Apalachicola
River and with a continued sharp E-W POP/cloud gradient as reflected
in CAM and other High Res models. Will go with 20-60% SE-NW POP
gradient. Increasing dry air aloft should decrease aerial coverage
and delay onset of any storms compared to previous days. Although
the concentrated bands of heavy, flooding rains are not expected and
the flood watch has expired, soils over the Florida Panhandle and
into Southeast Alabama remain quite moist, so any rainfall could
cause some localized flooding issues if rainfall rates are high
enough. CAM flood tool still shows up to 30% possibility. With more
sunshine expected than recent days, temps should rebound back to
near seasonal levels with highs in the mid-upper 80s west to low 90s
east.
&&
.SHORT TERM [Tonight Through Tuesday]...
The blocky pattern of the past week will completely break down
during this period as the Midwest upper low opens up and ejects
east across New England by Monday night. The Atlantic ridge will be
further weakened as it is undercut by the TUTT low, which will reach
far South FL on Tuesday. These transformations will finally cut off
the flow of deep layer tropical air into the region and allow the
dry air seen on water vapor imagery over the Atlantic to work its
way westward into the forecast area. At the surface, the subtropical
ridge axis will extend across the Southeast U.S. through the period.
The ridge axis will be north of the area through Monday and then
slip to near the Gulf Coast on Tuesday. However, because of the
influence of drier air aloft, rain chances will actually dip to
below normal levels for this time of year, a refreshing change from
the recent rains. Of course, the flip side of getting less rain is
that temps will rise closer to seasonal levels. Highs Monday will be
near normal in the lower 90s. On Tuesday, we will actually see
slightly above normal max temps in the mid 90s across many inland
locations.
&&
.LONG TERM [Tuesday Night through Saturday]...
A fairly typical summertime pattern is expected with daily diurnal
convection through the period. By mid-week, an upper level low is
expected to approach from the southeast which could enhance rain
chances a little bit. Towards the end of the week as ridging builds
over the Plains, we may temporarily transition to more of a
northwest flow pattern with a weak front approaching from the
northwest. Near seasonal temperatures are expected.
&&
.AVIATION [Through 12z Monday]...
Lower ceilings/vsbys remain possible with all sites except ECP
possibly experiencing IFR conditions thru 13Z. By mid morning
hours, more showers and thunderstorms could develop around north
Florida with precipitation chances spreading to all other terminals
by the afternoon. DHN and ECP will have the highest chances of
receiving precipitation. Brief MVFR CIGS/VSBYS possible in any heavy
rain. VFR conditions are expected 00z-08z then MVFR CIGS/VSBYS again
possible 08Z-12Z where residual moisture remains from today`s rains.
&&
.MARINE...
A surface ridge of high pressure will become reestablished north of
the area this week allowing winds and seas to return to typical
summertime levels. Winds will generally be out of the east or
southeast.
&&
.FIRE WEATHER...
Red Flag conditions are not expected in the foreseeable future.
&&
.HYDROLOGY...
The overall threat for significant flooding has largely ended. Most
rivers across our area are either nearing their crest or have
recently crested. The greatest impacts continue to be on the
Choctawhatchee River at Bruce-Ebro which will reach major flood
stage. The Sopchoppy River moved above moderate flood overnight but
should gradually fall through today. The following rivers are at
minor stage. The Withlacoochee above Valdosta, St Marks near
Newport, Apalachicola near Blountstown, Choctawatchee at Caryville
and about to go into moderate flooding for today is the
Choctawhatchee at Geneva.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 90 73 91 72 94 / 50 20 40 20 30
Panama City 86 75 89 74 91 / 60 20 40 20 20
Dothan 88 73 91 72 95 / 60 30 40 20 30
Albany 91 74 92 73 94 / 60 30 40 20 30
Valdosta 91 72 92 70 93 / 30 20 40 20 30
Cross City 92 70 93 69 94 / 20 20 30 20 30
Apalachicola 86 74 88 74 89 / 50 20 30 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation/Fire Weather...Block
Long Term...DVD
Hydrology...Block/Wool
Rest of Discussion...Wool
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
439 AM EDT Sun Jul 7 2013
...UPDATED FOR LACK OF PREDAWN RAIN AND FOR AVIATION SECTION...
.NEAR TERM [Today]...
Showers and isold tstms assocd with meeting of Gulf and east coast
seabreezes across Ern most counties late Sat eve weakened after
midnight. HRRR overforecast predawn precipitation over Wrn waters
and adjacent coastlines. Updated overnight grids to reflect this.
The large scale longwave blocking pattern continues to deamplify.
This is highlighted by a ridge over Wrn half of Conus, and a lifting
trough over Cntrl and Ern states with base over TN Valley and upper
low spinning from Mid Ms Valley into OH Valley. Looking east, a
ridge extends from high in Wrn Atlc a few hundred miles east of
Carolina coast WSW down South Atlc seaboard. Looking southeast, TUTT
low spinning invcnty of Bahamas. At the surface, Sly flow around Wrn
Atlc Bermuda high will remain over SE region.
During the rest of today, expect further lifting of low which will
reach Srn Great Lakes around sundown. This will allow Atlc high to
nose Swwd and deep layer ridge to encroach further inland pushing
tropical plume responsible for recent heavy rains further west of
our area. It will also combine with Wwd movement of TUTT placing CWA
closer to its subsident side. By this eve, TUTT actually moves under
ridge shifitng it back a little ewd. Lifting trough will also help
flatten Wrn and Atlc ridges and allow them to begin to bridge under
trough. However surface ridge axis remains to our north so ample low
level moisture remains. All this translates to increasing and strong
upper subsidence and dry air overspreading from the Atlc Swwd and
Nwwd to across local area. This reflected in model soundings which
show sharp W-E increase in mid level dry air and in decreasing PWAT.
i.e. GFS at 00z Mon with 1.79 in and 1.35 inches at TLH and JAX
respectively.
Thus scenario shifting somewhat to a more typical summertime pattern
of diurnal sea breeze convection especially east of the Apalachicola
River and with a continued sharp E-W POP/cloud gradient as reflected
in CAM and other High Res models. Will go with 20-60% SE-NW POP
gradient. Increasing dry air aloft should decrease aerial coverage
and delay onset of any storms compared to previous days. Although
the concentrated bands of heavy, flooding rains are not expected and
the flood watch has expired, soils over the Florida Panhandle and
into Southeast Alabama remain quite moist, so any rainfall could
cause some localized flooding issues if rainfall rates are high
enough. CAM flood tool still shows up to 30% possibility. With more
sunshine expected than recent days, temps should rebound back to
near seasonal levels with highs in the mid-upper 80s west to low 90s
east.
&&
.SHORT TERM [Tonight Through Tuesday]...
The blocky pattern of the past week will completely break down
during this period as the Midwest upper low opens up and ejects
east across New England by Monday night. The Atlantic ridge will be
further weakened as it is undercut by the TUTT low, which will reach
far South FL on Tuesday. These transformations will finally cut off
the flow of deep layer tropical air into the region and allow the
dry air seen on water vapor imagery over the Atlantic to work its
way westward into the forecast area. At the surface, the subtropical
ridge axis will extend across the Southeast U.S. through the period.
The ridge axis will be north of the area through Monday and then
slip to near the Gulf Coast on Tuesday. However, because of the
influence of drier air aloft, rain chances will actually dip to
below normal levels for this time of year, a refreshing change from
the recent rains. Of course, the flip side of getting less rain is
that temps will rise closer to seasonal levels. Highs Monday will be
near normal in the lower 90s. On Tuesday, we will actually see
slightly above normal max temps in the mid 90s across many inland
locations.
&&
.LONG TERM [Tuesday Night through Saturday]...
A fairly typical summertime pattern is expected with daily diurnal
convection through the period. By mid-week, an upper level low is
expected to approach from the southeast which could enhance rain
chances a little bit. Towards the end of the week as ridging builds
over the Plains, we may temporarily transition to more of a
northwest flow pattern with a weak front approaching from the
northwest. Near seasonal temperatures are expected.
&&
.AVIATION [Through 12z Monday]...
Lower ceilings/vsbys remain possible with all sites except ECP
possibly experiencing IFR conditions thru 13Z. By mid morning
hours, more showers and thunderstorms could develop around north
Florida with precipitation chances spreading to all other terminals
by the afternoon. DHN and ECP will have the highest chances of
receiving precipitation. Brief MVFR CIGS/VSBYS possible in any heavy
rain. VFR conditions are expected 00z-08z then MVFR CIGS/VSBYS again
possible 08Z-12Z where residual moisture remains from today`s rains.
&&
.MARINE...
A surface ridge of high pressure will become reestablished north of
the area this week allowing winds and seas to return to typical
summertime levels. Winds will generally be out of the east or
southeast.
&&
.FIRE WEATHER...
Red Flag conditions are not expected in the foreseeable future.
&&
.HYDROLOGY...
The overall threat for significant flooding has largely ended. Most
rivers across our area are either nearing their crest or have
recently crested. The greatest impacts continue to be on the
Choctawhatchee River at Bruce-Ebro which will reach major flood
stage. The Sopchoppy River moved above moderate flood overnight but
should gradually fall through today. All other rivers where flooding
is expected should generally crest in minor flood stage.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 90 73 91 72 94 / 50 20 40 20 30
Panama City 86 75 89 74 91 / 60 20 40 20 20
Dothan 88 73 91 72 95 / 60 30 40 20 30
Albany 91 74 92 73 94 / 60 30 40 20 30
Valdosta 91 72 92 70 93 / 30 20 40 20 30
Cross City 92 70 93 69 94 / 20 20 30 20 30
Apalachicola 86 74 88 74 89 / 50 20 30 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation/Fire Weather...Block
Long Term...DVD
Hydrology...Block/Wool
Rest of Discussion...Wool
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
250 AM EDT Sun Jul 7 2013
.NEAR TERM [Through Today]...
Showers and isold tstms assocd with meeting of Gulf and east coast
sea breezes across Ern most counties late Sat eve weakened after
midnight. HRRR shows rain south of Panama City Beach, but for
the most part, expect the bulk of this rain to remain just offshore
into this morning.
The large scale long wave blocking pattern continues to deamplify.
This is highlighted by a ridge over Wrn half of CONUS, and a lifting
trough over Cntrl and Ern states with base over TN Valley and upper
low spinning over Mid MS Valley. Looking east, a ridge extends Ewd
into Wrn Atlc with high east of NC coast with axis down Ern
seaboard. Looking southeast, TUTT low spinning in vcnty of the
Bahamas. At the surface, Sly flow around Wrn Atlc high will remain
over SE region.
During the rest of today, expect further lifting of low which will
reach Srn Great Lakes around sundown. This will allow Atlc high to
nose Swwd and deep layer ridge to encroach further inland and combine
with Wwd movement of TUTT placing CWA closer to its subsident side.
Lifting trough will also help flatten Wrn and Atlc ridges and allow
them to begin to bridge under trough. All this translates to
increasing and strong upper subsidence and dry air overspreading
from from the Atlc Swwd and Nwwd to across local area. This
reflected in model soundings which show sharp W-E increase in mid
level dry air and in decreasing PWAT. i.e. GFS at 00z Mon with 1.79
in and 1.35 inches at TLH and JAX respectively. However surface
ridge axis remains to our north so ample low level moisture remains.
Thus scenario shifting somewhat to a more typical summertime pattern
of diurnal sea breeze convection especially east of the Apalachicola
River and with a continued sharp E-W POP/cloud gradient as reflected
in CAM and other High Res models. Will go with 20-60% SE-NW POP
gradient. Increasing dry air aloft should decrease aerial coverage
and delay onset of any storms compared to previous days. Although
the concentrated bands of heavy, flooding rains are not expected and
the flood watch has expired, soils over the Florida Panhandle and
into Southeast Alabama remain quite moist, so any rainfall over the
next few days could cause some localized flooding issues if rainfall
rates are high enough. CAM flood tool still shows up to 30%
possibility. With more sunshine expected than recent days, temps
should rebound back to near seasonal levels with highs in the
mid-upper 80s west to low 90s east.
&&
.SHORT TERM [Tonight Through Tuesday]...
The blocky pattern of the past week will completely break down
during this period as the Midwest upper low opens up and ejects
east across New England by Monday night. The Atlantic ridge will be
further weakened as it is undercut by the TUTT low, which will reach
far South FL on Tuesday. These transformations will finally cut off
the flow of deep layer tropical air into the region and allow the
dry air seen on water vapor imagery over the Atlantic to work its
way westward into the forecast area. At the surface, the subtropical
ridge axis will extend across the Southeast U.S. through the period.
The ridge axis will be north of the area through Monday and then
slip to near the Gulf Coast on Tuesday. However, because of the
influence of drier air aloft, rain chances will actually dip to
below normal levels for this time of year, a refreshing change from
the recent rains. Of course, the flip side of getting less rain is
that temps will rise closer to seasonal levels. Highs Monday will be
near normal in the lower 90s. On Tuesday, we will actually see
slightly above normal max temps in the mid 90s across many inland
locations.
&&
.LONG TERM [Tuesday Night through Saturday]...
A fairly typical summertime pattern is expected with daily diurnal
convection through the period. By mid-week, an upper level low is
expected to approach from the southeast which could enhance rain
chances a little bit. Towards the end of the week as ridging builds
over the Plains, we may temporarily transition to more of a
northwest flow pattern with a weak front approaching from the
northwest. Near seasonal temperatures are expected.
&&
.AVIATION...
[Through 06z Monday] Lower ceilings are a possibility in the early
morning hours on Sunday, with all sites except ECP possibly
experiencing IFR conditions thru 13Z. By the late morning hours,
more showers and thunderstorms could develop around north Florida,
impacting ECP and TLH, with precipitation chances spreading to all
other terminals by the afternoon. DHN and ECP will have the
highest chances of receiving precipitation tomorrow, with IFR
conditions possible in any thunderstorms that develop. VFR
conditions are expected 00z-06z.
&&
.MARINE...
A surface ridge of high pressure will become reestablished north of
the area this week allowing winds and seas to return to typical
summertime levels. Winds will generally be out of the east or
southeast.
&&
.FIRE WEATHER...
Red Flag conditions are not expected in the foreseeable future.
&&
.HYDROLOGY...
Only light showers were noted overnight. The overall threat for
significant flooding has largely ended. Most rivers across our area
are either nearing their crest or have recently crested. The
greatest impacts continue to be on the Choctawhatchee River at
Bruce-Ebro which has reached major flood stage and will remain
above that level for several days. The latest crest forecast is
nearly a foot and a half above the previous forecast and should
occur on Monday. The Sopchoppy River moved above moderate flood
overnight but appears to have crested and should gradually fall
through today. All other rivers where flooding is expected should
generally crest in minor flood stage.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 90 73 91 72 94 / 50 20 40 20 30
Panama City 86 75 89 74 91 / 60 20 40 20 20
Dothan 88 73 91 72 95 / 60 30 40 20 30
Albany 91 74 92 73 94 / 60 30 40 20 30
Valdosta 91 72 92 70 93 / 30 20 40 20 30
Cross City 92 70 93 69 94 / 20 20 30 20 30
Apalachicola 86 74 88 74 89 / 50 20 30 20 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term/Aviation/Fire Weather...Block
Long Term...DVD
Hydrology...Block/Wool
Rest of Discussion...Wool
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
219 PM EDT SUN JUL 7 2013
.PREV DISCUSSION... /ISSUED 730 AM EDT SUN JUL 7 2013/
PREV DISCUSSION... /ISSUED 355 AM EDT SUN JUL 7 2013/
SHORT TERM /TODAY THROUGH MONDAY/...
WATER VAPOR LOOP CONTINUES TO SHOW DEEP MOISTURE BEING FUNNELED INTO
W GA FROM THE TROPICS. PWATS HAVE BUMPED BACK UP TO AROUND 2 INCHES
ACROSS NORTHERN GA ACCORDING TO THE 00Z FFC SOUNDING. MODELS SHOW
THIS HIGH MOISTURE AXIS REMAINING ACROSS THE CWFA THROUGH TONIGHT.
SOMEWHAT DRIER AIR HAS MOVED IN ACROSS THE EASTERN PORTION OF THE
CWFA.
UPPER LOW ACROSS THE OHIO VALLEY WILL SLOWLY EJECT INTO THE MIDDLE
ATLANTIC BY EARLY MONDAY MORNING. MEANWHILE...THE BERMUDA HIGH AT
THE SURFACE WILL BEGIN TO BUILD WESTWARD...ALSO HELPING SHIFT THE
TROPICAL PLUME WESTWARD. THIS SHOULD RESULT IN A DECREASE IN
PWATS/MOISTURE CONTENT DURING THE DAY ON MONDAY.
LATEST RUNS OF THE HRRR SHOW THE BEST CHANCE FOR POPS IS IN NW GA
THIS MORNING. THIS SEEMS REASONABLE AS PRECIP AXIS HAS NOT MOVED
MOST OF THE NIGHT. SCT/NMRS SHOWERS AND THUNDERSTORMS ARE EXPECTED
ACROSS THE REMAINDER OF THE CWFA THIS AFT/EVE BUT THEY SHOULD BE
MORE DIURNALLY DRIVEN.
FFG IS LESS THAN AN INCH AND A HALF ACROSS AREAS MOSTLY NORTH OF THE
FALL LINE. WILL NOT MAKE ANY CHANGES TO THE FLOOD WATCH FOR NOW.
NLISTEMAA
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
EXTENDED BEGINS WITH UPPER WAVE MOVING OFF THE NEW ENGLAND COAST
WHILE CLOSED LOW OVER THE BAHAMAS IS WORKING ITS WAY WEST...AND
BETWEEN THESE TWO THE ATLANTIC HIGH IS RIDGING INTO THE SOUTHEAST.
THE EXITING SYSTEM ACROSS NEW ENGLAND ALLOWS THE ASSOCIATED
SURFACE BOUNDARY/FRONT TO ELONGATE AND STRETCH ACROSS THE
SOUTHEAST. BEST PRECIP CHANCES WILL BE ACROSS NORTH GEORGIA.
ANOTHER LONGWAVE TROUGH PUSHES INTO SOUTHERN CANADA AND THE UPPER
MISSISSIPPI VALLEY BY MIDWEEK AND WITH CONTINUE SOUTHERLY FLOW
FROM THE ATLANTIC AND GULF...PRECIP CHANCES INCREASE AGAIN
WEDNESDAY AND ESPECIALLY INTO THURSDAY AS THE TROUGH DIGS INTO THE
OHIO VALLEY AND A SURFACE FRONT MOVES INTO THE TENNESSEE VALLEY.
REALLY REMARKABLE AGREEMENT BETWEEN THE GFS AND ECMWF THROUGH THIS
PERIOD...THOUGH THE ECMWF IS A TAD DEEPER WITH THE WAVE INTO THE
SOUTHEAST AND A LITTLE BIT MORE NEGATIVELY TILTED.
LATE IN THE WORK WEEK THIS TROUGH CONTINUES TO DIG AND DEEPEN INTO
THE GREAT LAKES...EVENTUALLY FORMING A CUTOFF LOW OVER THE UPPER
OHIO VALLEY. GFS A LITTLE FASTER WITH THIS TRANSITION BUT STILL
PRETTY SIMILAR IN OVERALL DEPICTION. TROUGH AXIS PROGGED TO BE
GENERALLY ACROSS THE MIDDLE OF THE STATE...THUS REDUCING PRECIP
CHANCES ACROSS NORTHWEST GEORGIA BUT KEEPING POPS IN SOUTHEAST
ZONES. THE LOW CONTINUES TO DEEPEN AND DIG TO THE SOUTHWEST...
RETROGRADING IN RESPONSE TO DEEPENING UPPER HIGH OVER THE DESERT
SOUTHWEST AND WESTERN PLAINS. BY THE END OF THE PERIOD THE CUTOFF
LOW IS SOMEWHERE EITHER IN THE TENNESSEE VALLEY OR SOUTHEAST...
WITH BOTH MODELS CONTINUING TO RETROGRADE IT TO THE WEST BEYOND
THE END OF THE PERIOD. SO IN GENERAL...IT LOOKS LIKE NEXT WEEK
COULD BE A REPEAT OF WHAT WE SAW THIS PAST WEEK WITH SIGNIFICANT
MOISTURE TRANSPORT OUT OF THE GULF. WILL WAIT AND SEE HOW THIS
PLAYS OUT.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. IF WE HAVE TO
PUT UP WITH ALL THE RAIN AND POTENTIAL FLOODING...AT LEAST WE GET
COOLER TEMPS OUT OF IT. HOWEVER...THERE IS A LARGER CONCERN THAT
WITH THIS CONTINUED WET PATTERN WE COULD BE SETTING THE STAGE FOR
SOME REAL PROBLEMS IF WE GET A TROPICAL SYSTEM MOVING IN.
TDP
&&
.AVIATION...
18Z UPDATE...
MOSTLY LIGHT RAIN ACROSS THE AREA RIGHT NOW WITH VFR TO MVFR
CEILINGS AND VSBYS. THIS LIGHT RAIN IS EXPECTED TO CONTINUE THROUGH
THE FORECAST PERIOD. THE RAIN WILL DIMINISH SOME OVER NIGHT BUT
RETURN AGAIN MONDAY. WINDS ARE OUT OF THE SW AND SHOULD TURN TO
THE SE AFTER 00Z. WINDS WILL GO BACK TO THE SW MONDAY AFTER
16-18Z. WINDS SPEEDS WILL STAY IN THE 5-10KT RANGE. CEILINGS AND
VSBYS SHOULD STAY IN THE VFR TO MVFR RANGE.
//ATL CONFIDENCE...18Z
UPDATE... CONFIDENCE MEDIUM ON ALL ELEMENTS.
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 70 86 71 / 70 50 50 30
ATLANTA 81 70 84 72 / 70 40 50 30
BLAIRSVILLE 75 67 78 66 / 70 50 60 30
CARTERSVILLE 80 69 86 69 / 70 40 60 30
COLUMBUS 84 73 89 73 / 70 30 50 20
GAINESVILLE 79 68 83 71 / 70 50 60 30
MACON 86 73 88 72 / 70 30 50 20
ROME 80 70 86 70 / 70 50 60 30
PEACHTREE CITY 81 70 84 70 / 70 40 50 30
VIDALIA 89 72 90 72 / 50 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...01
LONG TERM....41
AVIATION...01
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
730 AM EDT SUN JUL 7 2013
.PREV DISCUSSION... /ISSUED 355 AM EDT SUN JUL 7 2013/
SHORT TERM /TODAY THROUGH MONDAY/...
WATER VAPOR LOOP CONTINUES TO SHOW DEEP MOISTURE BEING FUNNELED INTO
W GA FROM THE TROPICS. PWATS HAVE BUMPED BACK UP TO AROUND 2 INCHES
ACROSS NORTHERN GA ACCORDING TO THE 00Z FFC SOUNDING. MODELS SHOW
THIS HIGH MOISTURE AXIS REMAINING ACROSS THE CWFA THROUGH TONIGHT.
SOMEWHAT DRIER AIR HAS MOVED IN ACROSS THE EASTERN PORTION OF THE
CWFA.
UPPER LOW ACROSS THE OHIO VALLEY WILL SLOWLY EJECT INTO THE MIDDLE
ATLANTIC BY EARLY MONDAY MORNING. MEANWHILE...THE BERMUDA HIGH AT
THE SURFACE WILL BEGIN TO BUILD WESTWARD...ALSO HELPING SHIFT THE
TROPICAL PLUME WESTWARD. THIS SHOULD RESULT IN A DECREASE IN
PWATS/MOISTURE CONTENT DURING THE DAY ON MONDAY.
LATEST RUNS OF THE HRRR SHOW THE BEST CHANCE FOR POPS IS IN NW GA
THIS MORNING. THIS SEEMS REASONABLE AS PRECIP AXIS HAS NOT MOVED
MOST OF THE NIGHT. SCT/NMRS SHOWERS AND THUNDERSTORMS ARE EXPECTED
ACROSS THE REMAINDER OF THE CWFA THIS AFT/EVE BUT THEY SHOULD BE
MORE DIURNALLY DRIVEN.
FFG IS LESS THAN AN INCH AND A HALF ACROSS AREAS MOSTLY NORTH OF THE
FALL LINE. WILL NOT MAKE ANY CHANGES TO THE FLOOD WATCH FOR NOW.
NLISTEMAA
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
EXTENDED BEGINS WITH UPPER WAVE MOVING OFF THE NEW ENGLAND COAST
WHILE CLOSED LOW OVER THE BAHAMAS IS WORKING ITS WAY WEST...AND
BETWEEN THESE TWO THE ATLANTIC HIGH IS RIDGING INTO THE SOUTHEAST.
THE EXITING SYSTEM ACROSS NEW ENGLAND ALLOWS THE ASSOCIATED
SURFACE BOUNDARY/FRONT TO ELONGATE AND STRETCH ACROSS THE
SOUTHEAST. BEST PRECIP CHANCES WILL BE ACROSS NORTH GEORGIA.
ANOTHER LONGWAVE TROUGH PUSHES INTO SOUTHERN CANADA AND THE UPPER
MISSISSIPPI VALLEY BY MIDWEEK AND WITH CONTINUE SOUTHERLY FLOW
FROM THE ATLANTIC AND GULF...PRECIP CHANCES INCREASE AGAIN
WEDNESDAY AND ESPECIALLY INTO THURSDAY AS THE TROUGH DIGS INTO THE
OHIO VALLEY AND A SURFACE FRONT MOVES INTO THE TENNESSEE VALLEY.
REALLY REMARKABLE AGREEMENT BETWEEN THE GFS AND ECMWF THROUGH THIS
PERIOD...THOUGH THE ECMWF IS A TAD DEEPER WITH THE WAVE INTO THE
SOUTHEAST AND A LITTLE BIT MORE NEGATIVELY TILTED.
LATE IN THE WORK WEEK THIS TROUGH CONTINUES TO DIG AND DEEPEN INTO
THE GREAT LAKES...EVENTUALLY FORMING A CUTOFF LOW OVER THE UPPER
OHIO VALLEY. GFS A LITTLE FASTER WITH THIS TRANSITION BUT STILL
PRETTY SIMILAR IN OVERALL DEPICTION. TROUGH AXIS PROGGED TO BE
GENERALLY ACROSS THE MIDDLE OF THE STATE...THUS REDUCING PRECIP
CHANCES ACROSS NORTHWEST GEORGIA BUT KEEPING POPS IN SOUTHEAST
ZONES. THE LOW CONTINUES TO DEEPEN AND DIG TO THE SOUTHWEST...
RETROGRADING IN RESPONSE TO DEEPENING UPPER HIGH OVER THE DESERT
SOUTHWEST AND WESTERN PLAINS. BY THE END OF THE PERIOD THE CUTOFF
LOW IS SOMEWHERE EITHER IN THE TENNESSEE VALLEY OR SOUTHEAST...
WITH BOTH MODELS CONTINUING TO RETROGRADE IT TO THE WEST BEYOND
THE END OF THE PERIOD. SO IN GENERAL...IT LOOKS LIKE NEXT WEEK
COULD BE A REPEAT OF WHAT WE SAW THIS PAST WEEK WITH SIGNIFICANT
MOISTURE TRANSPORT OUT OF THE GULF. WILL WAIT AND SEE HOW THIS
PLAYS OUT.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. IF WE HAVE TO
PUT UP WITH ALL THE RAIN AND POTENTIAL FLOODING...AT LEAST WE GET
COOLER TEMPS OUT OF IT. HOWEVER...THERE IS A LARGER CONCERN THAT
WITH THIS CONTINUED WET PATTERN WE COULD BE SETTING THE STAGE FOR
SOME REAL PROBLEMS IF WE GET A TROPICAL SYSTEM MOVING IN.
TDP
AVIATION...
06Z UPDATE...
TROPICAL MOISTURE PLUME CONTINUES ACROSS THE REGION. MODELS ARE
SUPPORTING IFR CIGS AT MANY OF THE AIRPORTS THROUGH EARLY SUNDAY
MORNING. THE 00Z NAM SOUNDINGS SUPPORT THIS. IN ADDITION...PATCHY
MVFR FOG WILL ALSO BE POSSIBLE. SKIES SHOULD REMAIN MCLDY THROUGH
THE DAY WITH CIGS BKN AROUND 035-040. SHRA/TSRA WILL DEVELOP
DURING PEAK HEATING. LOW CIGS ARE POSSIBLE AGAIN TOMORROW NIGHT.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE FOR WINDS. MEDIUM CONFIDENCE REMAINING ELEMENTS.
&&
.AVIATION...
12Z UPDATE...
IFR CIGS SHOULD LIFT TO MVFR BY 14-15Z AT ATL. SKIES WILL REMAIN
BKN THROUGH THE DAY...BUT VALUES SHOULD BE AROUND 035. DIURNALLY
DRIVEN CONVECTION EXPECTED THIS AFTERNOON. LATEST RUN OF THE HRRR
HAS BULF OF CONVECTION DEVELOPING JUST TO THE SOUTH OF ATL THIS
AFTERNOON...BUT WILL KEEP THE TEMPO GROUP IN DURING PEAK HEATING.
DO THINK COVERAGE WILL BE NMRS. LOW CIGS AGAIN TONIGHT...MAY HAVE
TO TWEAK TAFS LATER TO IFR VALUES.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 70 86 71 / 70 40 50 30
ATLANTA 81 70 84 72 / 70 40 50 30
BLAIRSVILLE 75 67 78 66 / 70 50 60 30
CARTERSVILLE 80 69 86 69 / 70 40 60 30
COLUMBUS 84 73 89 73 / 70 30 50 20
GAINESVILLE 79 68 83 71 / 70 50 60 30
MACON 86 73 88 72 / 70 30 50 20
ROME 80 70 86 70 / 70 50 60 30
PEACHTREE CITY 81 70 84 70 / 70 40 50 30
VIDALIA 89 72 90 73 / 50 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...ATWELL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
355 AM EDT SUN JUL 7 2013
.SHORT TERM /TODAY THROUGH MONDAY/...
WATER VAPOR LOOP CONTINUES TO SHOW DEEP MOISTURE BEING FUNNELED INTO
W GA FROM THE TROPICS. PWATS HAVE BUMPED BACK UP TO AROUND 2 INCHES
ACROSS NORTHERN GA ACCORDING TO THE 00Z FFC SOUNDING. MODELS SHOW
THIS HIGH MOISTURE AXIS REMAINING ACROSS THE CWFA THROUGH TONIGHT.
SOMEWHAT DRIER AIR HAS MOVED IN ACROSS THE EASTERN PORTION OF THE
CWFA.
UPPER LOW ACROSS THE OHIO VALLEY WILL SLOWLY EJECT INTO THE MIDDLE
ATLANTIC BY EARLY MONDAY MORNING. MEANWHILE...THE BERMUDA HIGH AT
THE SURFACE WILL BEGIN TO BUILD WESTWARD...ALSO HELPING SHIFT THE
TROPICAL PLUME WESTWARD. THIS SHOULD RESULT IN A DECREASE IN
PWATS/MOISTURE CONTENT DURING THE DAY ON MONDAY.
LATEST RUNS OF THE HRRR SHOW THE BEST CHANCE FOR POPS IS IN NW GA
THIS MORNING. THIS SEEMS REASONABLE AS PRECIP AXIS HAS NOT MOVED
MOST OF THE NIGHT. SCT/NMRS SHOWERS AND THUNDERSTORMS ARE EXPECTED
ACROSS THE REMAINDER OF THE CWFA THIS AFT/EVE BUT THEY SHOULD BE
MORE DIURNALLY DRIVEN.
FFG IS LESS THAN AN INCH AND A HALF ACROSS AREAS MOSTLY NORTH OF THE
FALL LINE. WILL NOT MAKE ANY CHANGES TO THE FLOOD WATCH FOR NOW.
NLISTEMAA
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
EXTENDED BEGINS WITH UPPER WAVE MOVING OFF THE NEW ENGLAND COAST
WHILE CLOSED LOW OVER THE BAHAMAS IS WORKING ITS WAY WEST...AND
BETWEEN THESE TWO THE ATLANTIC HIGH IS RIDGING INTO THE SOUTHEAST.
THE EXITING SYSTEM ACROSS NEW ENGLAND ALLOWS THE ASSOCIATED
SURFACE BOUNDARY/FRONT TO ELONGATE AND STRETCH ACROSS THE
SOUTHEAST. BEST PRECIP CHANCES WILL BE ACROSS NORTH GEORGIA.
ANOTHER LONGWAVE TROUGH PUSHES INTO SOUTHERN CANADA AND THE UPPER
MISSISSIPPI VALLEY BY MIDWEEK AND WITH CONTINUE SOUTHERLY FLOW
FROM THE ATLANTIC AND GULF...PRECIP CHANCES INCREASE AGAIN
WEDNESDAY AND ESPECIALLY INTO THURSDAY AS THE TROUGH DIGS INTO THE
OHIO VALLEY AND A SURFACE FRONT MOVES INTO THE TENNESSEE VALLEY.
REALLY REMARKABLE AGREEMENT BETWEEN THE GFS AND ECMWF THROUGH THIS
PERIOD...THOUGH THE ECMWF IS A TAD DEEPER WITH THE WAVE INTO THE
SOUTHEAST AND A LITTLE BIT MORE NEGATIVELY TILTED.
LATE IN THE WORK WEEK THIS TROUGH CONTINUES TO DIG AND DEEPEN INTO
THE GREAT LAKES...EVENTUALLY FORMING A CUTOFF LOW OVER THE UPPER
OHIO VALLEY. GFS A LITTLE FASTER WITH THIS TRANSITION BUT STILL
PRETTY SIMILAR IN OVERALL DEPICTION. TROUGH AXIS PROGGED TO BE
GENERALLY ACROSS THE MIDDLE OF THE STATE...THUS REDUCING PRECIP
CHANCES ACROSS NORTHWEST GEORGIA BUT KEEPING POPS IN SOUTHEAST
ZONES. THE LOW CONTINUES TO DEEPEN AND DIG TO THE SOUTHWEST...
RETROGRADING IN RESPONSE TO DEEPENING UPPER HIGH OVER THE DESERT
SOUTHWEST AND WESTERN PLAINS. BY THE END OF THE PERIOD THE CUTOFF
LOW IS SOMEWHERE EITHER IN THE TENNESSEE VALLEY OR SOUTHEAST...
WITH BOTH MODELS CONTINUING TO RETROGRADE IT TO THE WEST BEYOND
THE END OF THE PERIOD. SO IN GENERAL...IT LOOKS LIKE NEXT WEEK
COULD BE A REPEAT OF WHAT WE SAW THIS PAST WEEK WITH SIGNIFICANT
MOISTURE TRANSPORT OUT OF THE GULF. WILL WAIT AND SEE HOW THIS
PLAYS OUT.
TEMPS REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. IF WE HAVE TO
PUT UP WITH ALL THE RAIN AND POTENTIAL FLOODING...AT LEAST WE GET
COOLER TEMPS OUT OF IT. HOWEVER...THERE IS A LARGER CONCERN THAT
WITH THIS CONTINUED WET PATTERN WE COULD BE SETTING THE STAGE FOR
SOME REAL PROBLEMS IF WE GET A TROPICAL SYSTEM MOVING IN.
TDP
&&
.AVIATION...
06Z UPDATE...
TROPICAL MOISTURE PLUME CONTINUES ACROSS THE REGION. MODELS ARE
SUPPORTING IFR CIGS AT MANY OF THE AIRPORTS THROUGH EARLY SUNDAY
MORNING. THE 00Z NAM SOUNDINGS SUPPORT THIS. IN ADDITION...PATCHY
MVFR FOG WILL ALSO BE POSSIBLE. SKIES SHOULD REMAIN MCLDY THROUGH
THE DAY WITH CIGS BKN AROUND 035-040. SHRA/TSRA WILL DEVELOP
DURING PEAK HEATING. LOW CIGS ARE POSSIBLE AGAIN TOMORROW NIGHT.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE FOR WINDS. MEDIUM CONFIDENCE REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 82 70 86 71 / 70 40 50 30
ATLANTA 81 70 84 72 / 70 40 50 30
BLAIRSVILLE 75 67 78 66 / 70 50 60 30
CARTERSVILLE 80 69 86 69 / 70 40 60 30
COLUMBUS 84 73 89 73 / 70 30 50 20
GAINESVILLE 79 68 83 71 / 70 50 60 30
MACON 86 73 88 72 / 70 30 50 20
ROME 80 70 86 70 / 70 50 60 30
PEACHTREE CITY 81 70 84 70 / 70 40 50 30
VIDALIA 89 72 90 73 / 50 20 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES:
BANKS...BARROW...BARTOW...CARROLL...CATOOSA...CHATTOOGA...
CHEROKEE...CLARKE...CLAYTON...COBB...COWETA...DADE...DAWSON...
DEKALB...DOUGLAS...FANNIN...FAYETTE...FLOYD...FORSYTH...GILMER...
GORDON...GREENE...GWINNETT...HALL...HARALSON...HEARD...HENRY...
JACKSON...LUMPKIN...MADISON...MORGAN...MURRAY...NEWTON...NORTH
FULTON...OCONEE...OGLETHORPE...PAULDING...PICKENS...POLK...
ROCKDALE...SOUTH FULTON...TALIAFERRO...TOWNS...UNION...WALKER...
WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....TDP
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
736 PM EDT MON JUL 8 2013
.SYNOPSIS...
ISSUED AT 651 PM EDT MON JUL 8 2013
SHOWER AND THUNDERSTORM COVERAGE WILL INCREASE THROUGH THE EVENING
AND INTO THE OVERNIGHT HOURS TONIGHT WITH LOW TEMPERATURES IN THE
LOW 70S. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN ON
TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. A FEW OF THE
THUNDERSTORMS COULD BE STRONG TO SEVERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
COMPLICATED FCST PERIOD WRT CONVECTIVE POTENTIAL THIS EVENING AND
AGAIN ON TUESDAY.
AREA OF SHOWERS AND THUNDERSTORMS THAT DEVELOPED THIS MORNING ACROSS
NE IL HAVE ADVECTED INTO THE NW CWA THIS AFTERNOON. THIS AREA OF
SHOWERS APPEARS TO BE IN A DECAYING STATE...AND HAS WORKED OVER THE
ENVIRONMENT ACROSS MUCH OF THE AREA. THE DEGREE OF RECOVERY LATE
THIS AFTERNOON AND EARLY THIS EVENING WILL BE CRITICAL TO ANY
CONVECTIVE POTENTIAL GOING FORWARD INTO THE OVERNIGHT.
HI RES MODELS HAVE DONE A POOR JOB WITH THE CONVECTIVE EVOLUTION
OVER THE PAST 6 HOURS. HRRR AND 12Z SPC 4KM RUNS HAVE INDICATED A
W-E ORIENTED LINE OF CONVECTION DEVELOPING ACROSS THE LOWER GREAT
LAKES REGION AND SINKING SOUTHWARD ACROSS THE AREA...COINCIDENT WITH
SHORTWAVE ENERGY ADVECTING SOUTHEAST ACROSS THE LOWER GREAT LAKES
PER W/V. THE COVERAGE AND EXTENT OF THIS POTENTIAL CONVECTION WILL
BE HIGHLY DEPENDENT ON ATMOSPHERIC RECOVERY. RECENT RAP13 RUNS DO
INDICATED A STRONG LOW LVL THETA E POOLING ACROSS NRN IL...ADVECTING
INTO NRN IN THROUGH 00Z. THIS OPTIMISTIC SCENARIO WOULD ALLOW
MLCAPES TO RECOVER TO 1000-2000 J/KG. MODEST 0-6 KM BULK SHEAR
VALUES OF 25-30 KTS...AND 850-500 MB LAPSE RATES OF 5.5-6 C/KM WILL
KEEP SEVERE POTENTIAL LOW TO MARGINAL AT THIS POINT....HOWEVER AN
ISOLATED STORM PRODUCING STRONG TO SEVERE WIND GUSTS IS POSSIBLE.
GIVEN ALL OF THESE FACTORS...DECIDED TO LEAVE POPS IN THE SCATTERED
CATEGORY TONIGHT...WITH THE BEST POTENTIAL FOR CONVECTION BETWEEN
22Z AND 04Z.
CONVECTIVE OUTFLOW SHOULD PUSH PRECIP POTENTIAL SOUTHWARD THROUGH
THE OVERNIGHT HOURS...AND HAVE CONFINED SLIGHT CHANCE POPS TO THE
SOUTH. WARM AND MUGGY CONDITIONS ARE EXPECTED AGAIN ON TUESDAY WITH
HIGHS TOPPING OUT IN THE MID TO UPPER 80S...WITH HEAT INDICES IN THE
LOW TO MID 90S. REMNANT CONVECTIVE BOUNDARY MAY BE A FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TOMORROW WITH A JUICED ENVIRONMENT.
UPSTREAM SHORTWAVE EXPECTED TO ADVECT INTO THE REGION LATE TUESDAY
AFTERNOON...WHICH WILL PROVIDE MORE SUPPORT FOR CONVECTION. GIVEN
UNCERTAINTY WITH EVOLUTION OF CONVECTION THIS EVENING...AND
RESULTING BOUNDARY LOCATION...AS WELL AS UNCERTAINTY WITH THE
EVOLUTION OF CONVECTIVELY INDUCED SHORTWAVE...HAVE OPTED TO KEEP
POPS IN THE CHANCE RANGE...WITH THE HIGHEST IN THE AFTERNOON.
POTENTIAL FOR SEVERE WIND GUSTS TOMORROW DOES EXIST GIVEN HIGHLY
UNSTABLE ENVIRONMENT...BUT MODEST BULK SHEAR VALUES OF 25-30 KTS MAY
BE A LIMITING FACTOR FOR STORM ORGANIZATION.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
SHARPENING MID LVL TROUGH SWEEPING THROUGH SRN CANADA SHRT TERM WILL
PROPEL A VIGOROUS CDFNT THROUGH CWA ON WED. IN LIGHT OF DISPARATE
MODEL GUIDANCE WILL GENERALLY RELAY ON HIGHRES CONSENSUS OF FASTER
FROPA ESP WITHIN GUISE OF TUE NIGHT CONVN/MCS AND LIKELY OUTFLW
REMNANT COMPOSITING MORE EFFECTIVE DY3 FORCING MECHANISM SWD TWD THE
OH VALLEY. AS SUCH HAVE SHARPLY CURTAILED POPS ON WED.
AFT THAT...HIGH PRES TO RIDGE SWD ACRS THE LAKES AS MID LVL TROUGH
AMPLIFIES THROUGH NEW ENGLAND BRINGING SEASONABLE TEMPS TO THE
REGION AND DRY WX.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON JUL 8 2013
SHOWERS AND THUNDERSTORMS CONTINUE TO FIRE ALONG A SHARP
INSTABILITY GRADIENT DRAPED ACROSS OUR AREA. SYNOPTIC FORCING IS
WEAK WITH THE MAIN SHORTWAVE NOW EXITING EASTWARD BUT VERY MOIST
AND MARGINALLY UNSTABLE CONDITIONS WILL CONTINUE TO SUPPORT
CONVECTION THROUGH THE EVENING. A FEW STRONGER STORMS OVER
WISCONSIN WILL EVENTUALLY WORK THEIR WAY SOUTH AND MAY IMPACT KSBN
BUT THERE HAS ONLY BEEN A FEW LIGHTNING STRIKES AND INSTABILITY
WILL ONLY DECREASE ONCE THE SUN SETS. THE MAIN IMPACT WILL BE
HEAVY RAIN AND BRIEF MVFR CONDITIONS ARE POSSIBLE IF THESE SHOWERS
HIT THE TERMINALS. VERY MOIST BOUNDARY LAYER WILL LIKELY PROMOTE
PATCHY FOG BY EARLY TOMORROW MORNING. SURFACE WINDS WILL NOT GO
COMPLETELY CALM AND FORECAST SOUNDINGS ARE NOT SUPPORTIVE OF A
DENSE FOG EVENT BUT TEMPO IFR CONDITIONS ARE POSSIBLE. MORE
SHOWERS AND THUNDERSTORMS EXPECTED TOMORROW IN VERY WARM AND
UNSTABLE AIRMASS BUT CONFIDENCE IN EXACT TIMING IS TOO LOW TO
INCLUDE A MENTION AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...NG
LONG TERM...T
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1257 PM MDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1254 PM MDT SUN JUL 7 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS WITH SERIES OF WEAK SHORTWAVE TROUGHS
ROTATING AROUND WESTERN AND NORTHERN EXTENT OF RIDGE THROUGH
WESTERLY FLOW. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
KS/NE BORDER WITH A SURFACE TROUGH EXTENDING SOUTH ALONG THE KS/CO
BORDER.
A WEAK SHORTWAVE TROUGH EXPECTED TO DROP SOUTH OUT OF WESTERN
NEBRASKA LATE THIS AFTERNOON AND TONIGHT WILL COMBINE WITH THESE
SURFACE FEATURES TO INITIATE SCATTERED THUNDERSTORMS ACROSS THE CWA.
PRIMARY FOCUS SHOULD BE ALONG FRONT WHERE HIGH TD VALUES NORTH OF
THE FRONT HAVE RESULTED IN ML CAPE 1000-1500 J/KG AS OF THE LATEST
RAP ANALYSIS. BETTER DEEP SHEER IS EXPECTED TO BE IN PLACE NORTH OF
THE FRONT WHERE 0-6KM BULK SHEER AROUND 35KT BY 00Z COULD SUPPORT A
SEVERE WIND AND HAIL THREAT. THERE IS LESS INSTABILITY AND MORE CIN
TO OVERCOME FURTHER SOUTH ALONG THE SURFACE TROUGH...HOWEVER AS
DAYTIME HEATING CONTINUES AND THE SHORTWAVE TROUGH MOVES SOUTH WE
SHOULD BE ABLE TO SEE AT LEAST ISOLATED THUNDERSTORMS DEVELOPING
ALONG THE SURFACE TROUGH THIS AFTERNOON/EVENING. PWAT VALUES
1.2-1.3" REPRESENT AN ANOMALOUSLY WET ATMOSPHERE FOR THIS TIME OF
YEAR...AND AS WAS THE CASE YESTERDAY MANY OF THESE STORMS WILL BE
SLOW MOVERS...SO HEAVY RAIN WILL BE A CONCERN WHERE STORMS DEVELOP.
LEE TROUGH IS EXPECTED TO BEGIN TO DEEPEN LATE TONIGHT WITH LLJ
BUILDING ACROSS THE NE HALF OF THE CWA. WITH INCREASING ISENTROPIC
ASCENT AND H85 SUPPORT WE COULD SEE LINGERING THUNDERSTORMS IN
PROXIMITY OF THE FRONTAL ZONE ACROSS OUR NE CWA...SO I KEPT ISO
THUNDER MENTION MOST OF THE NIGHT FOR THOSE LOCATIONS. THERE IS
SOME INDICATION WITH VERY MOIST E-NE BL FLOW OF FOG DEVELOPING IN
SW NEBRASKA...HOWEVER WITH BL LIKELY MIXED WITH LLJ INCREASING AND
FRONT POSSIBLY SHIFTING NORTH I WASNT CONFIDENT ENOUGH TO ADD
MENTION.
DESPITE LARGE SCALE FORCING IN PLACE MONDAY IT DOES LOOK LIKE A
TROUGH AXIS/DRYLINE ALONG KS/CO BORDER COULD HELP INITIATE
THUNDERSTORMS BY THE AFTERNOON WITH INSTABILITY BUILDING ACROSS THE
EASTERN CWA. I WASNT CONFIDENT ENOUGH TO ADD MORE THAN SLIGHT CHANCE
MENTION AT THIS POINT. H85 TEMPS ARE ACTUALLY ADVERTISED TO BE 2-3C
WARMER THAN THE LAST FEW DAYS WHEN HIGHS HAVE BEEN AROUND 100F...SO
WE COULD BE LOOKING AT NEAR RECORD HIGH TEMPS ACROSS THE CWA MONDAY
WITH VALUES IN THE 100S ACROSS THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SUN JUL 7 2013
AN UPPER RIDGE CENTERED OVER THE SOUTHERN ROCKIES WILL BE THE
DOMINATING INFLUENCE THROUGH THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL...ALTHOUGH A WEAK COLD FRONT ON TUESDAY WILL
KNOCK TEMPERATURES DOWN A FEW DEGREES THROUGH THURSDAY...THEY WILL
WARM AGAIN FOR THE LATE WEEK AND WEEKEND. POSITION OF THE RIDGE
EARLY IN THE PERIOD WILL BE CLOSER TO THE FOUR CORNERS AND ALLOW
SHORTWAVE TROUGHS ROTATING AROUND IT TO BRING A CHANCE FOR SCATTERED
THUNDERSTORMS. AS THE RIDGE BUILDS EASTWARD LATER IN THE
WEEK...THUNDERSTORM CHANCES WILL BECOME MORE ISOLATED. SEVERE
WEATHER IS NOT ANTICIPATED WITH THE WEAK FLOW ALOFT LIMITING UPDRAFT
ORGANIZATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1110 AM MDT SUN JUL 7 2013
VFR CONDITIONS AND WINDS GENERALLY LESS THAN 12KT SHOULD PERSIST AT
BOTH KGLD AND KMCK TERMINALS THROUGH THE TAF PERIOD. WIND
DIRECTION WILL GENERALLY KEEP AN EASTERLY COMPONENT THROUGH THE
TAF PERIOD...THOUGH IT WILL BE SOMEWHAT ERRATIC DUE TO
THUNDERSTORM ACTIVITY AND FRONTAL POSITIONS. A STALLED FRONT ALONG
THE KS/CO BORDER WILL ACT AS A FOCUS FOR SCATTERED THUNDERSTORM
DEVELOPMENT THIS AFTERNOON/EVENING...WITH ACTIVITY POSSIBLY
LINGERING AT KMCK LATER THAN KGLD AS A DISTURBANCE PASSES TO THE
NORTH AND EAST. THERE IS SOME INDICATION BY MODELS OF MVFR VIS BY
SUNRISE MON WITH LIGHT FOG DEVELOPING AS A RESULT OF MOIST
EASTERLY FLOW NORTH OF THIS FRONT. WITH LLJ INCREASING BOUNDARY
LAYER MIXING OVER KGLD/KMCK AND FRONT BEGINNING TO SHIFT TO THE
NORTH AND WEST I AM NOT CONFIDENT ENOUGH TO ADD THIS TO TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DJR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1255 PM MDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1254 PM MDT SUN JUL 7 2013
LATEST WV IMAGERY AND RAP ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS WITH SERIES OF WEAK SHORTWAVE TROUGHS
ROTATING AROUND WESTERN AND NORTHERN EXTENT OF RIDGE THROUGH
WESTERLY FLOW. AT THE SURFACE A COLD FRONT HAS STALLED ALONG THE
KS/NE BORDER WITH A SURFACE TROUGH EXTENDING SOUTH ALONG THE KS/CO
BORDER.
A WEAK SHORTWAVE TROUGH EXPECTED TO DROP SOUTH OUT OF WESTERN
NEBRASKA LATE THIS AFTERNOON AND TONIGHT WILL COMBINE WITH THESE
SURFACE FEATURES TO INITIATE SCATTERED THUNDERSTORMS ACROSS THE CWA.
PRIMARY FOCUS SHOULD BE ALONG FRONT WHERE HIGH TD VALUES NORTH OF
THE FRONT HAVE RESULTED IN ML CAPE 1000-1500 J/KG AS OF THE LATEST
RAP ANALYSIS. BETTER DEEP SHEER IS EXPECTED TO BE IN PLACE NORTH OF
THE FRONT WHERE 0-6KM BULK SHEER AROUND 35KT BY 00Z COULD SUPPORT A
SEVERE WIND AND HAIL THREAT. THERE IS LESS INSTABILITY AND MORE CIN
TO OVERCOME FURTHER SOUTH ALONG THE SURFACE TROUGH...HOWEVER AS
DAYTIME HEATING CONTINUES AND THE SHORTWAVE TROUGH MOVES SOUTH WE
SHOULD BE ABLE TO SEE AT LEAST ISOLATED THUNDERSTORMS DEVELOPING
ALONG THE SURFACE TROUGH THIS AFTERNOON/EVENING. PWAT VALUES
1.2-1.3" REPRESENT AN ANOMALOUSLY WET ATMOSPHERE FOR THIS TIME OF
YEAR...AND AS WAS THE CASE YESTERDAY MANY OF THESE STORMS WILL BE
SLOW MOVERS...SO HEAVY RAIN WILL BE A CONCERN WHERE STORMS DEVELOP.
LEE TROUGH IS EXPECTED TO BEGIN TO DEEPEN LATE TONIGHT WITH LLJ
BUILDING ACROSS THE NE HALF OF THE CWA. WITH INCREASING ISENTROPIC
ASCENT AND H85 SUPPORT WE COULD SEE LINGERING THUNDERSTORMS IN
PROXIMITY OF THE FRONTAL ZONE ACROSS OUR NE CWA...SO I KEPT ISO
THUNDER MENTION MOST OF THE NIGHT FOR THOSE LOCATIONS. THERE IS
SOME INDICATION WITH VERY MOIST E-NE BL FLOW OF FOG DEVELOPING IN
SW NEBRASKA...HOWEVER WITH BL LIKELY MIXED WITH LLJ INCREASING AND
FRONT POSSIBLY SHIFTING NORTH I WASNT CONFIDENT ENOUGH TO ADD
MENTION.
DESPITE LARGE SCALE FORCING IN PLACE MONDAY IT DOES LOOK LIKE A
TROUGH AXIS/DRYLINE ALONG KS/CO BORDER COULD HELP INITIATE
THUNDERSTORMS BY THE AFTERNOON WITH INSTABILITY BUILDING ACROSS THE
EASTERN CWA. I WASNT CONFIDENT ENOUGH TO ADD MORE THAN SLIGHT CHANCE
MENTION AT THIS POINT. H85 TEMPS ARE ACTUALLY ADVERTISED TO BE 2-3C
WARMER THAN THE LAST FEW DAYS WHEN HIGHS HAVE BEEN AROUND 100F...SO
WE COULD BE LOOKING AT NEAR RECORD HIGH TEMPS ACROSS THE CWA MONDAY
WITH VALUES IN THE 100S ACROSS THE AREA.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 227 AM MDT SUN JUL 7 2013
LONG RANGE MODEL FORECAST INDICATES RIDGE PATTERN INCREASING IN
AMPLITUDE OVER THE FOUR CORNERS REGION FOR WEDNESDAY AND CONTINUING
TO BE PRESENT THROUGHOUT THE ENTIRE EXTENDED PERIOD. 500 MB HEIGHTS
WILL CONTINUE TO INCREASE IN MAGNITUDE INTO NEXT
WEEKEND...INDICATING THE INCREASING STRENGTH OF THE UPPER LEVEL
HIGH. THE UPPER LEVEL JET STREAM LOOKS TO STAY WELL TO THE NORTH
THROUGHOUT THE ENTIRE PERIOD. A SURFACE LOW PRESSURE SYSTEM WILL
STAY IN PLACE OVER THE TRI STATE AREA THROUGHOUT THE PERIOD WITH
STRONG WARM AIR ADVECTION MOVING INTO THE HIGH PLAINS. TEMPERATURES
LOOK TO BE IN THE MID 90S FOR WEDNESDAY AND THURSDAY...INCREASING TO
THE UPPER 90S TO LOW 100S ACROSS THE REGION FOR THE WEEKEND. BEST
CHANCE FOR PRECIPITATION WILL BE WEDNESDAY EVENING AND OVERNIGHT AS
STRONG SURFACE CONVERGENCE WILL HELP WITH THUNDERSTORM ACTIVITY.
ISOLATED CHANCES FOR THUNDERSTORM ACTIVITY WILL BE PRESENT MOSTLY
FOR THE EASTERN COUNTIES IN THE CWA FOR THURSDAY AND INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1110 AM MDT SUN JUL 7 2013
VFR CONDITIONS AND WINDS GENERALLY LESS THAN 12KT SHOULD PERSIST AT
BOTH KGLD AND KMCK TERMINALS THROUGH THE TAF PERIOD. WIND
DIRECTION WILL GENERALLY KEEP AN EASTERLY COMPONENT THROUGH THE
TAF PERIOD...THOUGH IT WILL BE SOMEWHAT ERRATIC DUE TO
THUNDERSTORM ACTIVITY AND FRONTAL POSITIONS. A STALLED FRONT ALONG
THE KS/CO BORDER WILL ACT AS A FOCUS FOR SCATTERED THUNDERSTORM
DEVELOPMENT THIS AFTERNOON/EVENING...WITH ACTIVITY POSSIBLY
LINGERING AT KMCK LATER THAN KGLD AS A DISTURBANCE PASSES TO THE
NORTH AND EAST. THERE IS SOME INDICATION BY MODELS OF MVFR VIS BY
SUNRISE MON WITH LIGHT FOG DEVELOPING AS A RESULT OF MOIST
EASTERLY FLOW NORTH OF THIS FRONT. WITH LLJ INCREASING BOUNDARY
LAYER MIXING OVER KGLD/KMCK AND FRONT BEGINNING TO SHIFT TO THE
NORTH AND WEST I AM NOT CONFIDENT ENOUGH TO ADD THIS TO TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
229 AM MDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 6 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS...WITH WESTERLY FLOW ACROSS THE NORTHERN
PLAINS. SURFACE TROUGH IS CURRENTLY IN PLACE ACROSS WESTERLY
NEBRASKA EXTENDING SOUTH ACROSS NW KS AND SE CO.
DESPITE LITTLE BEING APPARENT IN THE 500 MB HEIGHT FIELD BEYOND SOME
WEAK RIPPLES WV IMAGERY AND PV/VORT FIELDS CONTINUE TO INDICATE
VIGOROUS SHORTWAVE ACTIVITY ROTATING AROUND THE NORTHERN PART OF THE
RIDGE. ONE SUCH FEATURE IS PROGGED TO PASS OVER OUR CWA BY THIS
EVENING...WHICH SHOULD HELP INCREASE THUNDERSTORM CHANCES ACROSS THE
REGION. I COULDNT RULE OUT BETTER COVERAGE THAN THE LAST FEW NIGHTS
WITH SURFACE TROUGH POSSIBLY ACTING TO AID THUNDERSTORM INITIATION AS
SHORTWAVE PASSES THROUGH THE REGION. I STILL EXPECT ACTIVITY TO
INITIALLY START OVER HIGHER TERRAIN THIS AFTERNOON AND BEGIN TO
SPREAD EAST WITH SHORTWAVE. LATEST HRRR/RAP SUPPORT THIS ACTIVITY
INCREASING IN COVERAGE BY 00-03Z AS THIS INTERACTS WITH SHORTWAVE
TROUGH AXIS AND BETTER INSTABILITY ACROSS THE CENTRAL/EASTERN PART
OF CWA. THERE IS SOME LINGERING ELEVATED INSTABILITY
OVERNIGHT...HOWEVER LLJ IS EAST OF CWA ALONG WITH BEST ISOTROPIC
SUPPORT...SO BEYOND SOME LINGERING SHOWERS/T-STORMS WITH SHORTWAVE
LATE TONIGHT IN THE EAST WITH SHORTWAVE I THINK MOST OF THIS
ACTIVITY WILL BE TAPERING OFF FAIRLY QUICKLY AFTER SUNSET.
HODOGRAPHS/SHEER PROFILES ARE RELATIVELY WEAK AND WITH MARGINAL CAPE
I AM NOT SURE WE WOULD SEE MUCH OF A SEVERE HAIL RISK. INVERTED V
TYPE SOUNDINGS AND DCAPE VALUES IN THE 500-1500 J/KG RANGE RAISE
CONCERNS FOR SEVERE GUST POTENTIAL WITH ANY COLLAPSING UPDRAFTS...SO
THIS WILL NEED TO BE MONITORED.
WITH LITTLE CHANGING REGARDING LARGE SCALE PATTERN AND MODELS
INDICATING POSSIBLE EARLIER INITIATION SUN I KEPT MENTION OF
THUNDERSTORM CHANCES SUNDAY AFTERNOON...WITH ONLY MINOR ADJUSTMENTS
TO TIMING. HOT AIRMASS WILL STILL BE IN PLACE SUN...WITH EXPECTED
CLOUD COVER THE ONE LIMITING FACTOR. FEWER CLOUDS...AND WE SHOULD
AGAIN SEE HIGHS APPROACH 100F ACROSS THE ENTIRE AREA.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 227 AM MDT SUN JUL 7 2013
LONG RANGE MODEL FORECAST INDICATES RIDGE PATTERN INCREASING IN
AMPLITUDE OVER THE FOUR CORNERS REGION FOR WEDNESDAY AND CONTINUING
TO BE PRESENT THROUGHOUT THE ENTIRE EXTENDED PERIOD. 500 MB HEIGHTS
WILL CONTINUE TO INCREASE IN MAGNITUDE INTO NEXT
WEEKEND...INDICATING THE INCREASING STRENGTH OF THE UPPER LEVEL
HIGH. THE UPPER LEVEL JET STREAM LOOKS TO STAY WELL TO THE NORTH
THROUGHOUT THE ENTIRE PERIOD. A SURFACE LOW PRESSURE SYSTEM WILL
STAY IN PLACE OVER THE TRI STATE AREA THROUGHOUT THE PERIOD WITH
STRONG WARM AIR ADVECTION MOVING INTO THE HIGH PLAINS. TEMPERATURES
LOOK TO BE IN THE MID 90S FOR WEDNESDAY AND THURSDAY...INCREASING TO
THE UPPER 90S TO LOW 100S ACROSS THE REGION FOR THE WEEKEND. BEST
CHANCE FOR PRECIPITATION WILL BE WEDNESDAY EVENING AND OVERNIGHT AS
STRONG SURFACE CONVERGENCE WILL HELP WITH THUNDERSTORM ACTIVITY.
ISOLATED CHANCES FOR THUNDERSTORM ACTIVITY WILL BE PRESENT MOSTLY
FOR THE EASTERN COUNTIES IN THE CWA FOR THURSDAY AND INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1100 PM MDT SAT JUL 6 2013
VFR EXPECTED AT KGLD AND KMCK THROUGH THE PERIOD. SFC TROUGH WITH
LGT/VRB WINDS TO LINGER NEAR BOTH TERMINALS THROUGH 15-17Z BEFORE
BECOMING EASTERLY THEN SOUTHEASTERLY AT 10KTS OR SO. AS HAS BEEN
THE CASE THE PAST FEW DAYS SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE DURING THE LATE AFTERNOON AND EVENING HOURS. PINPOINTING
WHETHER OR NOT THEY WILL DIRECTLY IMPACT EITHER TERMINAL RATHER
DIFFICULT AND FOR NOW NOT INCLUDE A MENTION IN EITHER TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1101 PM MDT SAT JUL 6 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 1251 PM MDT SAT JUL 6 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW H5 RIDGE STILL IN PLACE
ACROSS SOUTHERN PLAINS...WITH WESTERLY FLOW ACROSS THE NORTHERN
PLAINS. SURFACE TROUGH IS CURRENTLY IN PLACE ACROSS WESTERLY
NEBRASKA EXTENDING SOUTH ACROSS NW KS AND SE CO.
DESPITE LITTLE BEING APPARENT IN THE 500 MB HEIGHT FIELD BEYOND SOME
WEAK RIPPLES WV IMAGERY AND PV/VORT FIELDS CONTINUE TO INDICATE
VIGOROUS SHORTWAVE ACTIVITY ROTATING AROUND THE NORTHERN PART OF THE
RIDGE. ONE SUCH FEATURE IS PROGGED TO PASS OVER OUR CWA BY THIS
EVENING...WHICH SHOULD HELP INCREASE THUNDERSTORM CHANCES ACROSS THE
REGION. I COULDNT RULE OUT BETTER COVERAGE THAN THE LAST FEW NIGHTS
WITH SURFACE TROUGH POSSIBLY ACTING TO AID THUNDERSTORM INITIATION AS
SHORTWAVE PASSES THROUGH THE REGION. I STILL EXPECT ACTIVITY TO
INITIALLY START OVER HIGHER TERRAIN THIS AFTERNOON AND BEGIN TO
SPREAD EAST WITH SHORTWAVE. LATEST HRRR/RAP SUPPORT THIS ACTIVITY
INCREASING IN COVERAGE BY 00-03Z AS THIS INTERACTS WITH SHORTWAVE
TROUGH AXIS AND BETTER INSTABILITY ACROSS THE CENTRAL/EASTERN PART
OF CWA. THERE IS SOME LINGERING ELEVATED INSTABILITY
OVERNIGHT...HOWEVER LLJ IS EAST OF CWA ALONG WITH BEST ISOTROPIC
SUPPORT...SO BEYOND SOME LINGERING SHOWERS/T-STORMS WITH SHORTWAVE
LATE TONIGHT IN THE EAST WITH SHORTWAVE I THINK MOST OF THIS
ACTIVITY WILL BE TAPERING OFF FAIRLY QUICKLY AFTER SUNSET.
HODOGRAPHS/SHEER PROFILES ARE RELATIVELY WEAK AND WITH MARGINAL CAPE
I AM NOT SURE WE WOULD SEE MUCH OF A SEVERE HAIL RISK. INVERTED V
TYPE SOUNDINGS AND DCAPE VALUES IN THE 500-1500 J/KG RANGE RAISE
CONCERNS FOR SEVERE GUST POTENTIAL WITH ANY COLLAPSING UPDRAFTS...SO
THIS WILL NEED TO BE MONITORED.
WITH LITTLE CHANGING REGARDING LARGE SCALE PATTERN AND MODELS
INDICATING POSSIBLE EARLIER INITIATION SUN I KEPT MENTION OF
THUNDERSTORM CHANCES SUNDAY AFTERNOON...WITH ONLY MINOR ADJUSTMENTS
TO TIMING. HOT AIRMASS WILL STILL BE IN PLACE SUN...WITH EXPECTED
CLOUD COVER THE ONE LIMITING FACTOR. FEWER CLOUDS...AND WE SHOULD
AGAIN SEE HIGHS APPROACH 100F ACROSS THE ENTIRE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 1255 PM MDT SAT JUL 6 2013
AN UPPER RIDGE CENTERED OVER THE CENTRAL AND SOUTHERN ROCKIES WILL
BE THE DOMINATING INFLUENCE IN THE LONG TERM PERIOD. TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD...WITH THE HOTTEST DAYS
BEING FRIDAY AND SATURDAY. A WEAK COLD FRONT WILL MOVE THROUGH
TUESDAY AND TUESDAY NIGHT WITH SLIGHTLY COOLER TEMPERATURES IN ITS
WAKE. THERE WILL BE SEVERAL OPPORTUNITIES FOR SCATTERED
THUNDERSTORMS ASSOCIATED WITH WEAK SHORTWAVE TROUGHS ROTATING
AROUND THE RIDGE...BUT WITH THE WEAK FLOW ALOFT SEVERE WEATHER IS
NOT ANTICIPATED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1100 PM MDT SAT JUL 6 2013
VFR EXPECTED AT KGLD AND KMCK THROUGH THE PERIOD. SFC TROUGH WITH
LGT/VRB WINDS TO LINGER NEAR BOTH TERMINALS THROUGH 15-17Z BEFORE
BECOMING EASTERLY THEN SOUTHEASTERLY AT 10KTS OR SO. AS HAS BEEN
THE CASE THE PAST FEW DAYS SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE DURING THE LATE AFTERNOON AND EVENING HOURS. PINPOINTING
WHETHER OR NOT THEY WILL DIRECTLY IMPACT EITHER TERMINAL RATHER
DIFFICULT AND FOR NOW NOT INCLUDE A MENTION IN EITHER TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1041 PM EDT MON JUL 8 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE ACROSS NEW ENGLAND TONIGHT KEEPING
UNSETTLED CONDITIONS ACROSS THE AREA. COOL EASTERLY FLOW WILL KEEP
CONDITIONS COOL AND CLOUDY FOR MUCH OF TUESDAY. A WARM FRONT WILL
PUSH SLOWLY NORTH ACROSS NEW ENGLAND ON WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST THURSDAY THEN SLOWLY DRIFT ACROSS NEW
ENGLAND THURSDAY NIGHT THEN MOVE OFFSHORE ON FRIDAY. THIS COLD
FRONT WILL CONTINUE TO SLOWLY MOVE OUT TO SEA OVER THE WEEKEND AS
WEAK HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.NEAR TERM /UNTIL 8 AM TUESDAY MORNING/...
UPDATE...00Z HRRR CONTINUES TO HAVE A GOOD HANDLE ON CURRENT
LOCATIONS OF SHRA. HAVE USED ITS POP GRIDS TO TREND THE NEXT 6
HOURS OF THE FORECAST...AS SHRA SLOWLY MEANDER INTO WRN ME. IT HAS
ALSO BACKED OFF THE COASTAL STRATUS FOR A FEW HOURS...WAITING
UNTIL AFTER 09Z TO CREEP INTO COASTAL ME. WILL PROBABLY BE
AMENDING TAFS TO ACCOUNT FOR THE DELAYED TIMING.
PREVIOUS DISCUSSION...FLASH FLOOD WATCH REMAINS IN EFFECT
THROUGH MIDNIGHT...ALTHOUGH CONVECTION THIS AFTERNOON HAS BEEN
MORE SPARSE THAN EXPECTED. EASTERLY FLOW SPREADING ACROSS MAINE
AND SOUTHEASTERN NEW HAMPSHIRE THIS AFTERNOON HAS SUPPRESSED
CONVECTIVE ACTIVITY. MODEST INSTABILITY DOES STILL EXIST ACROSS
THE AREA SO WE ARE HESITANT TO TAKE DOWN A WATCH AT THIS HOUR.
MEANWHILE DEW POINT TEMPERATURES ACROSS MAINE AND COASTAL NEW
HAMPSHIRE HAVE FALLEN THROUGH THE 60S WITH SOME UPPER 50S AT THE
TIME OF THIS WRITING. EXPECT SHOWERS FIRING IN NEW HAMPSHIRE TO
SPREAD EASTWARD INTO SOUTHERN MAINE LATE THIS EVENING THEN PUSH
SOUTHWARD TOWARD DAYBREAK. PATCHY FOG AND PERHAPS SOME DRIZZLE
LATE TONIGHT AS WELL GIVEN THE EASTERLY NEAR-SURFACE FLOW.
&&
.SHORT TERM /8 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
LOW CLOUDS AND COOL TEMPERATURES WILL BE THE RULE FOR TUESDAY AS
LIGHT EASTERLY WINDS KEEP A WEAK SHORTWAVE RIDGE FROM CLEARING
SKIES. WITH LOWER HUMIDITIES IT WILL FEEL MORE LIKE SEPTEMBER
ACROSS THE REGION. LOW PRECIPITATION CHANCES UNDER THE WEAK RIDGE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AN UPPER LEVEL TROUGH CARVES OUT ACROSS THE UPPER MIDWEST AND GREAT
LAKES REGION ON WEDNESDAY AS IT ALSO SLOWLY SHIFTS TO THE EAST. THIS
SETS UP AN INCREASINGLY VERY WARM AND HUMID SOUTHWEST FLOW ALOFT AS
THE TEMPERATURES AT 850 MILLIBARS CLIMB ABOVE 15 CELSIUS AT 12Z
WEDNESDAY AND CONTINUE THROUGH THURSDAY AS THE UPPER LEVEL TROUGH
SLOWLY WORKS ITS WAY TO THE EAST COAST. AT THE SURFACE A WARM FRONT
MOVES SLOWLY TO THE NORTHEAST ACROSS THE REGION AS THE VERY WARM AND
HUMID AIR MOVES IN.
THIS IS FOLLOWED BY A SLOW MOVING COLD FRONT MOVING IN FROM THE WEST
ON THURSDAY. THE FRONT TAKES ITS TIME DRIFTING OFF THE COAST
THURSDAY NIGHT AND FRIDAY AS THE UPPER LEVEL TROUGH BEGINS TO CUTOFF
AND STALL ALONG THE EASTERN SEABOARD. THIS SLOW MOVING SYSTEM WILL
MEAN A PERIOD OF SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS
WEDNESDAY THROUGH THURSDAY. SCATTERED SHOWERS LINGER INTO FRIDAY.
THE UPPER LEVEL CUTOFF WEAKENS AS THE SURFACE COLD FRONT MOVES OUT
TO SEA SATURDAY THROUGH MONDAY AS WEAK HIGH PRESSURE BUILDS IN FROM
THE WEST. DRIER WEATHER GRADUALLY OVERTAKES THE REGION BUT STILL A
SLIGHT CHANCE OF SHOWERS WILL HOLD ON.
GENERALLY USED BLEND OF GFS/NAM/MET/MAV/HPC QPF FOR PERIODS 4 AND 5
THEN GFS40/GMOS/MEX FOR THE REST OF THE LONG TERM FCST.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...EXPECT NEARLY ALL AREAS TO LOWER TO MVFR WITH IFR IN
FOG AND RAIN OVERNIGHT. MVFR CONDITIONS AGAIN TUESDAY IN LOW
CLOUDS AND DISSIPATING FOG. SOME IMPROVEMENT LATE TUESDAY UNDER
SHORTWAVE RIDGE.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...IFR IN SHOWERS AND
POSSIBLE THUNDERSTORMS WEDNESDAY THROUGH THURSDAY THEN MVFR/IFR
POSSIBLE IN SCATTERED SHOWERS FRIDAY THROUGH SATURDAY.
&&
.MARINE...
SHORT TERM...LIGHT EASTERLY WINDS THROUGH TUESDAY NIGHT WILL
RESULT IN 2 TO 4 FOOT SEAS IN THE OUTER WATERS. NO HEADLINES
EXPECTED. VISIBILITY COULD BE REDUCED IN FOG AND DRIZZLE.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...WINDS AND SEAS STAY
BELOW SCA LEVELS THROUGH THE LONG TERM FORECAST PERIOD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
810 PM EDT MON JUL 8 2013
.SYNOPSIS...
WARM AND HUMID WEATHER WITH A CHANCE OF A SHOWER OR THUNDERSTORM
WILL CONTINUE THROUGH MIDWEEK. A COLD FRONT WILL APPROACH THE AREA
BY LATE WEDNESDAY INTO THURSDAY WITH A BETTER CHANCE OF SHOWERS
AND STORMS. COOLER AND DRIER AIR WILL FILTER INTO THE REGION
BEHIND THE FRONT.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS SUGGESTED BY RECENT HI-RES MODEL RUNS...ONGOING CNVCTN OVER OH
HAS SHOWN WEAKENING TREND AS IT PROGRESSES EWD. POPS WERE ADJUSTED
TO REFLECT THE PCPN MOVG INTO WRN ZONES THRU EARLY EVE.
A SECOND SHRTWV TROF WILL INVIGORATE CNVCTN LATE TNGT...WHICH IS
XPCD TO MOVE THRU THE FCST AREA THRU TUE MRNG. THESE SHWRS AND
TSTMS WILL BE FED BY AN AMPLE FETCH OF LOW-LVL MSTR CHARACTERIZED
BY DEWPTS IN THE LOW 70S.
WITH DEPARTURE OF CNVCTN IN THE MRNG...SOME BREAKS IN CLD CVR XPCD
BY LATE MRNG OR EARLY AFTN...WHICH WILL CONTRIBUTE TO POTL FOR
DESTABILIZATION VIA HEATING OF VERY MST BNDRY LYR. THIS PSBLTY IS
MOST LKLY IN WRN AND NWRN CTYS...WHERE BRF SHRTWV RDGG XPCD IN
WAKE OF MRNG CNVCTN.
THERE IS A CONDITIONAL THREAT OF SVR WX TUE AFTN IF THE MDT INSTBY
SHOWN IN THE LATEST NAM RUN IS REALIZED AND ABLE TO OVERCOME THE
RELATIVELY MODEST SHEAR. SVR THREAT WOULD BE MAINLY FROM WET
MICROBURSTS.
OWING TO MRNG CNVCTN AND LINGERING CLD CVR...CONTD IDEA FROM PREV
FCST OF SLGTLY COOLER MAXIMA. LWR 80S XPCD GENLY IN ERN ZONES...
WITH MID 80S XPCD IN WRN ZONES...WHERE SOME INSOLATION PSBL. PREV
DISCUSSION FOLLOWS...
HIGH RESOLUTION MODELS INDICATE BASICALLY EXACTLY WHAT HAS BEEN
OCCURRING LATE THIS MORNING AND VERY EARLY AFTERNOON...THAT
CONVECTIVE TRENDS SHOULD BE DOWNWARD ACROSS THE AREA. THE MID-
LEVEL LOW IS DEPARTING TO THE EAST...AND LIKELY WITH IT THE MID-
LEVEL COLD POOL INDUCED INSTABILITY THAT WAS ALLOWING FOR BETTER
SHOWER/THUNDERSTORM COVERAGE EARLIER TODAY. AS SUCH...SHOWER
CHANCES HAVE BEEN ROLLED BACK ACROSS THE AREA TO NOTHING MORE THAN
ISOLATED ANYWHERE.
A FAIRLY PRONOUNCED AND STILL STRENGTHENING SHORT WAVE TROUGH IS
MOVING THROUGH THE UPPER GREAT LAKES AT THE MOMENT...WITH
WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH IT.
BOTH HIGH RESOLUTION AS WELL AS LARGE SCALE MODELS HAVE A GOOD
HANDLE ON THIS SYSTEM...TRACKING IT TOWARD OUR WESTERN COUNTIES BY
ROUGHLY 00Z THIS EVENING...AND ACROSS THE REST OF THE AREA THIS
EVENING AND OVERNIGHT. POPS WERE ALREADY HIGH IN THE
FORECAST...AND THESE HIGH POPS WERE MAINTAINED AS THE SYSTEM
TRACKS ACROSS THE FORECAST AREA THROUGH THE NIGHT.
AS TONIGHT`S SYSTEM DEPARTS TO THE EAST BY LATE MORNING/AFTERNOON
TUESDAY...FORCING FOR ASCENT REALLY DIMINISHES. AT LEAST SOME
CLEARING SHOULD BE EVIDENT BEHIND THAT SYSTEM GIVEN SUBSIDENCE AND
A BIT OF LAYER DRYING. AS SUCH...BREAKS IN THE CLOUDS SHOULD ALLOW
FOR TEMPERATURES TO RUN UP RATHER QUICKLY WHENEVER/WHEREVER THE
SUN DOES COME OUT. WHILE THE AREA AS A WHOLE WILL LIKELY STICK IN
THE 80S...A VERY MOIST BOUNDARY LAYER WITH DEWPOINTS IN THE LOWER
70S ON A WIDESPREAD BASIS WILL MAKE TUESDAY A VERY UNCOMFORTABLE
DAY. FRIES
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
H5 FLOW INITIALLY STARTS ZONAL AT BEGINNING THIS FORECAST PERIOD.
HOWEVER...UPPER LEVEL WAVE WILL DEEPEN TROF FROM CANADIAN PLAINS
THROUGH MIDWEST AND THIS WILL SUPPORT SURFACE COLD FRONT WHICH
WILL PUSH THROUGH CWA LATE WEDNESDAY. IN ADVANCE...CONVECTION TO
DEVELOP OR POSSIBLY BE ONGOING IN ADVANCE OF FRONT. APPEARS PLENTY
OF MOISTURE WITH SFC TD/S UPPER 60S TO AROUND 70 AND PW/S 1.5+.
MODELS HAVE GOOD DEAL OF MOISTURE PROJECTED IN LOWER AND MID-
TROPOSPHERE AND IF ENOUGH CLOUDINESS...COULD HINDER INSTABILITY. IN
THOSE AREAS WITH LESS CLOUDS CAPE COULD REACH 1000-2000 OR SO.
SHEAR SEEMS A BIT LACKING AT THIS TIME WITH BULK SHEAR ABOUT 30 KTS.
ALSO...AT THIS TIME CALIBRATED SEVERE FIELD FROM SREF MODEST AT
BEST WITH RATHER LOW PROBABILITIES. MOST LIKELY BECAUSE PREDICTED
LACK OF SIGNIFICANT SHEAR. WILL CONTINUE TO MONITOR FOR POTENTIAL.
POSSIBLY SOME LINGERING SHOWERS EARLY THURSDAY. HOWEVER...AS FRONT
CONTINUES SOUTHEAST...DRIER AND COOLER AIR TO MOVE INTO REGION BY
LATER THURSDAY AND INTO THURSDAY NIGHT. SMALL FLY IN THE OINTMENT
AT THIS TIME IS THAT GFS CUTS OFF H5 LOW WHICH COULD RETARD
STRENGTH OF CLEARING. ECMWF SLOWER WITH H5 LOW AND DEVELOPS IT
MUCH LATER. SIGNIFICANT UNCERTAINTY AT THIS TIME ON H5 LOW
DEVELOPMENT AND TIMING.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FRONT WILL SLOWLY CROSS THE REGION WED NIGHT. SHIFTING HIGHEST
POPS FROM NORTH TO SOUTH.
COOLER AND LESS HUMID AIR ARRIVES BY WEEKS END...HWVR THE BIG
QUESTION IS WHAT HAPPENS TO H5 CYCLONE ONCE IT CROSSES THE REGION?
GFS TAKES IT SW INTO THE GULF COAST STATES...WHILE ECMWF LIFTS IT
NE AND DEVELOPS A STRONG MID LVL ANTICYCLONE ACRS THE GULF COAST.
&&
.AVIATION /00Z TUESDAY THROUGH TUESDAY NIGHT/...
SHORT WAVE SUPPORTING SHOWERS AND THUNDERSTORMS CURRENTLY WESTERN
LAKE ERIE THROUGH CENTRAL OH. PROGRESSION EAST ABOUT 20 KTS. MODELS
TEND TO DIMINISH FIRST WAVE OF PRECIP AND THEN SUBSEQUENT SWATH
COMES THROUGH A LITTLE LATER WITH BULK OF PRECIP BETWEEN 06Z TO 13Z
OR SO. INSERTED SOME BR BY MORNING. ALSO...SEVERAL TERMINALS OPTED
TO GO WITH PREVAILING 5-6SM -SHRA AND THEN VCTS. HRRR NOT
ADVERTISING WIDESPREAD IFR ST/SC CEILINGS EITHER DURING OR IN WAKE
OF PRECIPITATION SHIELD. AS A RESULT, OPTED TO GO MVFR MOST
TERMINALS. WINDS OUTSIDE ANY CONVECTION GENERALLY LIGHT AND FROM THE
SOUTHWEST 190-240 DEGREES AT 4 TO 7 KTS.
OUTLOOK.../TUESDAY NIGHT THROUGH FRIDAY/...
MOSTLY ZONAL FLOW BY TUESDAY NIGHT...HOWEVER...EMBEDDED WAVES WILL
TRIGGER SOME SCT CONVECTION TUESDAY NIGHT. AT THIS TIME BETTER CHANCE
FOR WIDER COVERAGE AND STRONGER STORMS WOULD BE ON WEDNESDAY AS
STRONGER WAVE DIVES SE FROM CANADA. COLD FRONT TO PASS CWA BY MIDDAY
THURSDAY AND COOLER AND DRIER AIR TO FILTER INTO REGION. RESTRICTIONS
ON WEDNESDAY INTO THURSDAY MORNING...THEN VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
KRAMAR/FRIES/KANE
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
131 PM EDT SUN JUL 7 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE CAROLINA COAST TODAY...BEFORE
DRIFTING SOUTHEAST MONDAY AS LOW PRESSURE LIFTS THROUGH THE
NORTHEAST STATES. THE ASSOCIATED FRONTAL BOUNDARY DROPS THROUGH THE
MID ATLANTIC MONDAY AND DISSIPATES OVER THE CAROLINAS TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST IR/WV SAT IMAGERY SHOWING AN UPPER LOW OVER IN/IL AT 15Z THIS
MORNING. A MOIST FRONTAL PLUME WAS NOTED FLOWING NORTHWARD AHEAD
OF THE LOW FROM THE EASTERN GULF COAST TO THE EASTERN GREAT LAKES.
MEANWHILE...SUBTROPICAL HIGH PRESSURE (SFC AND ALOFT) REMAINS
ANCHORED OFF THE CAROLINA COAST.
NO MAJOR CHANGES NECESSARY TO THE GOING FORECAST ATTM. THE UPPER
SYSTEM IS WILL CONTINUE TO SLOWLY LIFT TOWARD THE EASTERN GREAT
LAKES TODAY...WITH THE FRONTAL BAND SLOWLY MOVING EASTWARD OVER
THE APPALACHIANS. THERE IS A LACK OF SYNOPTIC SCALE FORCING TODAY
TO TRIGGER CONVECTION LOCALLY DESPITE A RATHER UNSTABLE
ENVIRONMENT. HRRR CONTINUES TO PICK UP ON THIS TREND WELL,
YIELDING ONLY AN ISOLATED TSRA OR TWO AT MOST THROUGH 22Z/6PM.
ACCORDINGLY...HAVE PUSHED BACK POPS WITH SLOWER ONSET THROUGH THIS
TIME FRAME, ORIENTING ISO T WORDING ALONG AND WEST OF HIGHWAY 15
IN THE FAR NW PIEDMONT COUNTIES.
THERE IS VERY LITTLE CHANGE IN THE LOW-LEVEL THERMAL PROFILE, AND
THUS HV STUCK CLOSE TO A PERSISTENCE FORECAST FOR TODAY`S MAXIMA.
LOOK FOR HIGHS RISING INTO THE UPPER 80S IMMEDIATE COAST...TO LOW
90S INLAND. DEWPOINTS SHOULD MIX DOWN INTO THE UPPER 60S DURING
PEAK HEATING...HENCE RESULTANT HEAT INDICES SHOULD ONLY BE A FEW
DEGREES HIGHER THAN THE AMBIENT TEMPERATURE. SKY COVER
CHARACTERIZED AS PARTLY SUNNY WEST TO MOSTLY SUNNY EAST FOR THE
BALANCE OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE UPPER LOW LIFTS ACROSS THE NORTHEAST AND DAMPENS TONIGHT AND
MONDAY...WITH THE FRONTAL BAND DROPPING INTO THE MID ATLANTIC.
LATEST NUMERICAL GUIDANCE BRINGS THE MOISTURE PLUME INTO THE REGION
MONDAY MORNING AND SLOWLY DROPS IT SE INTO SE VA AND NE NC BY THE
AFTERNOON. THE EARLIER TIMING (EARLIER ARRIVAL OF MID-CLOUDS) ALONG
WITH MOIST ADIABATIC MID-LEVEL LAPSE RATES HAMPERS POTENTIAL
INSTABILITY...WHICH WOULD LIMIT CONVECTIVE COVERAGE MONDAY AFTERNOON.
ADDITIONALLY...THE MID/UPPER LEVEL FLOW BECOMES MORE ZONAL...WHICH
WOULD FURTHER LIMIT COVERAGE. GIVEN THIS...HAVE LOWERED POPS TO
LOW-END CHANCE.
0-6KM BULK SHEAR VALUES ARE STILL PROGGED TO REACH 25-30KT...SO
THERE IS A POSSIBILITY OF ISOLATED STRONGER THUNDERSTORMS IF A FEW
POCKETS OF HIGHER INSTABILITY DO DEVELOP. THE MAIN THREAT WOULD BE
BRIEF HEAVY RAIN AND STRONG WIND GUSTS.
THE BOUNDARY WASHES OUT TUESDAY AS ZONAL PREVAILS ACROSS THE REGION.
GFS/NAM EACH INDICATE AROUND 1500-1800 J/KG OF MLCAPE TUESDAY
AFTERNOON. HOWEVER...DEEP LAYER SHEAR WILL BE MUCH LESS ALONG WITH
LITTLE SYNOPTIC SCALE FORCING. THE HIGHER TERRAIN TO THE WEST WILL
LIKELY BE THE TRIGGER FOR ANY THUNDERSTORMS...SOME OF WHICH COULD
DRIFT EAST INTO THE PIEDMONT...SO CHANCE POPS WILL BE MAINTAINED
THERE WITH SLIGHT CHANCE FARTHER EAST.
SEASONABLY HOT (ALTHOUGH NOT EXCESSIVE) AND HUMID CONDITIONS WILL
CONTINUE MONDAY AND TUESDAY. HIGHS SHOULD RANGE FROM THE UPPER 80S
TO LOW 90S...ALONG WITH LOWS IN THE LOW/MID 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF TUE NGT INTO WED WITH ZONAL FLOW ALOFT
OVER THE MID ATLANTIC AND AN UPR-LVL LO STARTING TO DIG OVER THE
GREAT LAKES REGION. ALTHO BEST FORCING AND MOISTURE WILL STAY NW OF
THE LOCAL AREA WED...DID INCLUDE A 20-30% CHC FOR SHRAS/TSTMS DUE TO
DIURNALLY-DRIVEN CONVECTION IN THE WARM SECTOR. BETTER CHC FOR RAIN
(40-50%) COMES LATE THU AS THE UPR-LVL TROF AND ASSOCIATED COLD FRONT
APPROACH FROM THE OH VALLEY AND DEEP-LAYER MOISTURE INCREASES. THE
FRONT WILL SLOW DOWN/STALL OVER THE AREA FRI (AND ALSO SAT?) LEADING
TO CONTINUED CHCS FOR SHRAS/TSTMS.
SLY FLOW AND ABUNDANT LO-LVL MOISTURE WILL CONTINUE TO PRODUCE HUMID
CONDS (DEWPTS AVG IN THE LWR 70S) WITH HI TEMPS IN THE UPR 80S/LWR
90S AND LO TEMPS AVG IN THE LWR 70S.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SOME CU AROUND THIS AFTERNOON WITH VFR CIGS NOW AT ALL TAF SITES.
LOOKING AT THE MODEL SOUNDINGS THE CU WILL DISSIPATE AFTER SUNSET
WITH MAINLY SOME CI LEFT. HOWEVER OUT TOWARD RIC COULD HAVE MORE
CLOUDS AS AN UPPER SYSTEM STARTS MOVING TO THE NW OF RIC. THIS
COULD EVEN BRING A SHOWER INTO RIC AFTER MIDNIGHT. KEEPING VFR
CONDITIONS TONIGHT AS BELIEVE ENOUGH WINDS WILL OCCUR TO KEEP
MIXING UP. THE UPPER TROF PUSHES ACROSS TO THE N OF THE AREA ON
MON. THIS COULD PRODUCE SCATTERED SHOWERS OR TSTMS DURING THE DAY
ON MONDAY. MODELS INDICATE THE BEST CHANCES OVER SE VA TO NE NORTH
CAROLINA BY AFTERNOON. OUTSIDE OF THE SHOWERS AND THUNDERSTORMS
VFR CONDITIONS WILL PREVAIL ON MONDAY.
OUTLOOK...SCATTERED TSTMS...MAINLY AFTN/EVE WILL BE POSSIBLE TUE
AND WED. MORE WIDESPREAD PCPN IS POSSIBLE LATE IN THE WEEK.
&&
.MARINE...
GENERALLY BENIGN SUB-SCA CONDITIONS OVER THE MARINE AREA THRU AT
LEAST THE MIDDLE OF THE COMING WEEK. BERMUDA HIGH PRESSURE WILL
SLOWLY WEAKEN/DRIFT EASTWARD TODAY THRU TONIGHT AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. NO STRONG SFC FRONT WILL BE
ASSOCIATED WITH THIS SYSTEM. WINDS THRU MIDWEEK WILL AVG 10-15 KT
OUT OF THE S/SW. EXPECT 1-2 FT WAVES OVER THE BAY AND 2-3 FT SEAS
OVER COASTAL WATERS...APPROACHING 4 FT OUT 20 NM ON MON AND AGAIN
WED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/JAB
MARINE...JDM
AREA FORECAST DISCUSSION...CORRECTION
NWS WAKEFIELD VA
1130 AM EDT SUN JUL 7 2013
.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OFF THE CAROLINA COAST TODAY...BEFORE
DRIFTING SOUTHEAST MONDAY AS LOW PRESSURE LIFTS THROUGH THE
NORTHEAST STATES. THE ASSOCIATED FRONTAL BOUNDARY DROPS THROUGH THE
MID ATLANTIC MONDAY AND DISSIPATES OVER THE CAROLINAS TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST IR/WV SAT IMAGERY SHOWING AN UPPER LOW OVER IN/IL AT 15Z THIS
MORNING. A MOIST FRONTAL PLUME WAS NOTED FLOWING NORTHWARD AHEAD
OF THE LOW FROM THE EASTERN GULF COAST TO THE EASTERN GREAT LAKES.
MEANWHILE...SUBTROPICAL HIGH PRESSURE (SFC AND ALOFT) REMAINS
ANCHORED OFF THE CAROLINA COAST.
NO MAJOR CHANGES NECESSARY TO THE GOING FORECAST ATTM. THE UPPER
SYSTEM IS WILL CONTINUE TO SLOWLY LIFT TOWARD THE EASTERN GREAT
LAKES TODAY...WITH THE FRONTAL BAND SLOWLY MOVING EASTWARD OVER
THE APPALACHIANS. THERE IS A LACK OF SYNOPTIC SCALE FORCING TODAY
TO TRIGGER CONVECTION LOCALLY DESPITE A RATHER UNSTABLE
ENVIRONMENT. HRRR CONTINUES TO PICK UP ON THIS TREND WELL,
YIELDING ONLY AN ISOLATED TSRA OR TWO AT MOST THROUGH 22Z/6PM.
ACCORDINGLY...HAVE PUSHED BACK POPS WITH SLOWER ONSET THROUGH THIS
TIME FRAME, ORIENTING ISO T WORDING ALONG AND WEST OF HIGHWAY 15
IN THE FAR NW PIEDMONT COUNTIES.
THERE IS VERY LITTLE CHANGE IN THE LOW-LEVEL THERMAL PROFILE, AND
THUS HV STUCK CLOSE TO A PERSISTENCE FORECAST FOR TODAY`S MAXIMA.
LOOK FOR HIGHS RISING INTO THE UPPER 80S IMMEDIATE COAST...TO LOW
90S INLAND. DEWPOINTS SHOULD MIX DOWN INTO THE UPPER 60S DURING
PEAK HEATING...HENCE RESULTANT HEAT INDICES SHOULD ONLY BE A FEW
DEGREES HIGHER THAN THE AMBIENT TEMPERATURE. SKY COVER
CHARACTERIZED AS PARTLY SUNNY WEST TO MOSTLY SUNNY EAST FOR THE
BALANCE OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE UPPER LOW LIFTS ACROSS THE NORTHEAST AND DAMPENS TONIGHT AND
MONDAY...WITH THE FRONTAL BAND DROPPING INTO THE MID ATLANTIC.
LATEST NUMERICAL GUIDANCE BRINGS THE MOISTURE PLUME INTO THE REGION
MONDAY MORNING AND SLOWLY DROPS IT SE INTO SE VA AND NE NC BY THE
AFTERNOON. THE EARLIER TIMING (EARLIER ARRIVAL OF MID-CLOUDS) ALONG
WITH MOIST ADIABATIC MID-LEVEL LAPSE RATES HAMPERS POTENTIAL
INSTABILITY...WHICH WOULD LIMIT CONVECTIVE COVERAGE MONDAY AFTERNOON.
ADDITIONALLY...THE MID/UPPER LEVEL FLOW BECOMES MORE ZONAL...WHICH
WOULD FURTHER LIMIT COVERAGE. GIVEN THIS...HAVE LOWERED POPS TO
LOW-END CHANCE.
0-6KM BULK SHEAR VALUES ARE STILL PROGGED TO REACH 25-30KT...SO
THERE IS A POSSIBILITY OF ISOLATED STRONGER THUNDERSTORMS IF A FEW
POCKETS OF HIGHER INSTABILITY DO DEVELOP. THE MAIN THREAT WOULD BE
BRIEF HEAVY RAIN AND STRONG WIND GUSTS.
THE BOUNDARY WASHES OUT TUESDAY AS ZONAL PREVAILS ACROSS THE REGION.
GFS/NAM EACH INDICATE AROUND 1500-1800 J/KG OF MLCAPE TUESDAY
AFTERNOON. HOWEVER...DEEP LAYER SHEAR WILL BE MUCH LESS ALONG WITH
LITTLE SYNOPTIC SCALE FORCING. THE HIGHER TERRAIN TO THE WEST WILL
LIKELY BE THE TRIGGER FOR ANY THUNDERSTORMS...SOME OF WHICH COULD
DRIFT EAST INTO THE PIEDMONT...SO CHANCE POPS WILL BE MAINTAINED
THERE WITH SLIGHT CHANCE FARTHER EAST.
SEASONABLY HOT (ALTHOUGH NOT EXCESSIVE) AND HUMID CONDITIONS WILL
CONTINUE MONDAY AND TUESDAY. HIGHS SHOULD RANGE FROM THE UPPER 80S
TO LOW 90S...ALONG WITH LOWS IN THE LOW/MID 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LONG TERM PERIOD STARTS OFF TUE NGT INTO WED WITH ZONAL FLOW ALOFT
OVER THE MID ATLANTIC AND AN UPR-LVL LO STARTING TO DIG OVER THE
GREAT LAKES REGION. ALTHO BEST FORCING AND MOISTURE WILL STAY NW OF
THE LOCAL AREA WED...DID INCLUDE A 20-30% CHC FOR SHRAS/TSTMS DUE TO
DIURNALLY-DRIVEN CONVECTION IN THE WARM SECTOR. BETTER CHC FOR RAIN
(40-50%) COMES LATE THU AS THE UPR-LVL TROF AND ASSOCIATED COLD FRONT
APPROACH FROM THE OH VALLEY AND DEEP-LAYER MOISTURE INCREASES. THE
FRONT WILL SLOW DOWN/STALL OVER THE AREA FRI (AND ALSO SAT?) LEADING
TO CONTINUED CHCS FOR SHRAS/TSTMS.
SLY FLOW AND ABUNDANT LO-LVL MOISTURE WILL CONTINUE TO PRODUCE HUMID
CONDS (DEWPTS AVG IN THE LWR 70S) WITH HI TEMPS IN THE UPR 80S/LWR
90S AND LO TEMPS AVG IN THE LWR 70S.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND RELATIVELY LIGHT WINDS ARE EXPECTED THROUGH THE
TAF PERIOD. ISOLD AFTN TSMS ARE POSSIBLE THIS AFTERNOON...MAINLY
WEST OF KRIC.
OUTLOOK...SCATTERED TSTMS...MAINLY AFTN/EVE WILL BE POSSIBLE MON-
WED. MORE WIDESPREAD PCPN IS POSSIBLE LATE IN THE WEEK.
&&
.MARINE...
GENERALLY BENIGN SUB-SCA CONDITIONS OVER THE MARINE AREA THRU AT
LEAST THE MIDDLE OF THE COMING WEEK. BERMUDA HIGH PRESSURE WILL
SLOWLY WEAKEN/DRIFT EASTWARD TODAY THRU TONIGHT AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. NO STRONG SFC FRONT WILL BE
ASSOCIATED WITH THIS SYSTEM. WINDS THRU MIDWEEK WILL AVG 10-15 KT
OUT OF THE S/SW. EXPECT 1-2 FT WAVES OVER THE BAY AND 2-3 FT SEAS
OVER COASTAL WATERS...APPROACHING 4 FT OUT 20 NM ON MON AND AGAIN
WED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ
LONG TERM...MAS
AVIATION...JDM/DAP
MARINE...JDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
139 PM EDT SUN JUL 7 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 314 AM EDT SUN JUL 7 2013
THE WEATHER PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS. IT
WILL REMAIN WARM AND HUMID WITH HIGHS IN THE MID TO UPPER 80S. WE
WILL ALSO SEE SCATTERED SHOWERS AND STORMS. THE BEST CHANCE OF
PRECIPITATION IN THE SHORT TERM WILL COME LATE TONIGHT INTO MONDAY
MORNING...WITH ANOTHER GOOD CHANCE ON TUESDAY.
THE SHOWERS AND STORMS SHOULD LINGER INTO WEDNESDAY...BUT THEN THE
LATTER HALF OF THE WEEK LOOKS DRY. DAYTIME TEMPERATURES WILL
LARGELY BE IN THE 80 TO 85 DEGREE RANGE FROM MID WEEK INTO NEXT
WEEKEND.
&&
.UPDATE...
ISSUED AT 1048 AM EDT SUN JUL 7 2013
I UPDATED THE ZONE FORECAST TO INCREASE THE CHANCE FOR SHOWERS
INTO EARLY THIS AFTERNOON OVER THE EASTERN SECTIONS OUR OUR CWA
AND TO DECREASE THE FORECAST HIGH A TOUCH SINCE THERE IS A
CONSIDERABLE AMOUNT OF MID CLOUD AROUND.
THE 700 MB LOW IS NEARLY OVERHEAD OF GRAND RAPIDS AT 9 AM BASED ON
RADAR DATA SHOWING THE SHOWERS PINWHEELING AROUND GRAND RAPIDS.
THIS IS ALSO SUPPORTED BY BOTH VISIBLE SATELLITE LOOPS AND RAP
MODEL 12Z FORECAST. THAT SUPPORTS THE SHOWERS OVER THE INFLOW
SECTION OF THE LOW...EAST OF GRR ACTUALLY WITH A DEFORMATION ZONE
FEATURE FROM NORTHERN KENT COUNTY INTO GRATIOT COUNTY. NOT MUCH
THUNDER HAPPENING THOUGH. WHILE THAT WAS HAPPENING THERE IS AN MCS
OVER THE WESTERN UPPER PENINSULA OF MICHIGAN THAT SEEMS TO BE
WEAKENING AND BUILDING TOWARD THE SOUTHEAST.
WITH THE 700 MB LOW WEAKENING AND MOVING INTO EASTERN LOWER
MICHIGAN THIS AFTERNOON THAT WOULD PUT WESTERN LOWER MICHIGAN IN
NORTHWEST SUBSIDING FLOW ON THE WEST SIDE OF THE LOW. NOT A GOOD
THING IF ONE WANTS SHOWERS. SO MY SPIN IS THE CLOUDS AND SHOWERS
WILL GRADUALLY MOVE EAST OF SOUTHWEST LOWER MICHIGAN DURING THE
AFTERNOON. WITH THE SUBSIDENCE ON THE WEST SIDE OF THE SYSTEM I DO
NOT SEE MUCH THREAT FOR CONVECTION TO DEVELOP SO I HAVE VERY LOW
POPS WEST OF US-131 AFTER 1 PM (WEST WINDS OFF LAKE MICHIGAN DO
NOT HELP THE CAUSE FOR CONVECTION MUCH EITHER).THIS IS STRONGLY
SUPPORTED BY RAP MODEL SOUNDING WITH SHOW A VERY DRY LOOKING
SOUNDING FROM THE SURFACE THROUGH 300 MB BY 21Z NEAR GRR.
IT IS MORE MOIST ON THE RAP SOUNDING IN THE LAN/JXN AREA THIS
AFTERNOON WITH NEAR 1800 J/KG OF CAPE BUT I WITH GENERIC WEST WINDS
THROUGH 700 MB BY 21Z I SEE LITTLE REASON FOR MUCH SURFACE
CONVERGENCE SO I AM STILL NOT TO EXITED ABOUT STORM POTENTIAL EVEN THERE.
WE WILL HAVE TO WATCH WHAT HAPPENS WITH THE MCS OVER THE WESTERN
UPPER PENINSULA FOR THIS EVENING BUT EVEN THERE... THE LOW LEVEL
JET IS LARGELY IN WISCONSIN THIS EVENING AND THE BEST JET DYNAMICS
ARE OVER NORTHERN WI AND THE MICHIGAN UP SO I BELIEVE LITTLE WILL
HAPPEN OVER WESTERN LOWER MICHIGAN TONIGHT EITHER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 314 AM EDT SUN JUL 7 2013
WIDELY SCATTERED SHOWERS AND STORMS WILL CONTINUE THROUGH THE SHORT
TERM. HOWEVER THE PRECIPITATION SHOULD BECOME MORE WIDESPREAD LATE
TONIGHT INTO MONDAY MORNING...AND THEN AGAIN ON TUESDAY. IT WILL
REMAIN WARM AND HUMID THROUGH TUESDAY.
AN UPPER LOW WAS OVER SE IL THIS MORNING AND IT WAS DRIFTING NE.
THIS WILL BRING THE CENTER OF THE LOW TO NE INDIANA BY THIS
AFTERNOON. THIS IS FURTHER NORTH THAN WHAT PREVIOUS MODELS HAVE
BEEN SHOWING. FOR THE PAST FEW DAYS THERE HAS BEEN DAYTIME
THUNDERSTORMS NEAR AND AROUND THIS LOW. HOWEVER THE COVERAGE OF THE
PCPN STILL WARRANTS 30/40 POPS. ALSO BY THE END OF THE DAY A COLD
FRONT WILL BE MOVING ACROSS WI. THIS COULD BRING ISOLATED PCPN INTO
THE NW CWA AND 20/30 POPS WILL BE CARRIED OVER THE NW CWA.
DECENT SET UP FOR AN MCS TO ROLL ALONG THE FRONT TO OUR WEST TONIGHT
WITH THE ASSISTANCE OF A LOW LEVEL JET. SEEMS LIKE THIS MAY TRACK
NEAR THE MI/IN BORDER LATE TONIGHT IN A WEAKENING STATE. ITS
DOUBTFUL THAT SEVERE WILL OCCUR AS THIS COMPLEX WILL BE RUNNING AWAY
FROM THE BEST INSTABILITY AND JET SUPPORT BY THE TIME IT REACHES
US...BUT WILL CARRY 40/50 POPS SOUTH OF I-96.
EXPECT SOMEWHAT LESS CONVECTION INTO MONDAY AFTERNOON AND MONDAY
NIGHT. THE FRONT EASES INTO THE REGION...BUT IT WASHES OUT OVER THE
NORTHERN OR CENTRAL CWA. THIS MAY SUPPORT SOME WIDELY SCATTERED
STORMS BUT WITHOUT A FOCUSED JET THESE SHOULD NOT BE SEVERE.
ANOTHER UP TICK IN THE STORM ACTIVITY IS EXPECTED INTO TUESDAY.
ANOTHER COLD FRONT WILL BE CROSSING WI WITH A STRONG LOW LEVEL JET
ALONG IT. THE CONVERGENCE FROM THIS JET SHOULD REACH US BY LATE
AFTERNOON WHEN THE CHANCE OF ORGANIZED/SEVERE STORMS WILL BE
POSSIBLE. HAVE INCREASED POPS TO LIKELY SOUTH OF I-96 AS THIS IS
WHERE THE LLJ IS PROGGED TO BE NOSING INTO.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN JUL 7 2013
BEST CHANCE OF RAIN IN THE EXTENDED WILL BE TUESDAY NIGHT INTO
EARLY WEDNESDAY AS UPPER TROUGH AXIS AND SFC LOW MOVES THROUGH.
PLENTY OF MOISTURE AVAILABLE AND MCS DEVELOPMENT IS POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY MORNING WITH HEAVY RAIN THREAT. MODELS HAVE
TRENDED TO A LESS AMPLIFIED TROUGH AND WEAKER SHEAR PROFILES SO
SEVERE THREAT NOW SEEMS TO BE DIMINISHED.
KEPT THE LATTER PART OF THE WEEK DRY AS SFC HIGH IS IN PLACE AND DRY
SOUNDINGS RULE FROM LATE WEDNESDAY THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 138 PM EDT SUN JUL 7 2013
CONDITIONS SHOULD BE VFR FOR THE MAJORITY OF THE TIME THROUGH 18Z
MON...WITH SOME MVFR POSSIBLE IN FOG TONIGHT AND ISOLATED SHOWERS.
LOWER CLOUD COVER IN PLACE EARLIER THIS MORNING HAS BROKEN
UP/LIFTED INTO A VFR DECK THIS AFTERNOON. SOME SCATTERED CLOUDS
AROUND 2000-3000 FT STILL COULD BRIEFLY GO MVFR...BUT CONDITIONS
WILL GENERALLY IMPROVE THROUGH THE AFTERNOON. THERE COULD BE A
SHOWER ACROSS THE ERN TERMINALS OF KLAN AND KJXN DUE TO THE UPPER
LOW CLOSER BY...SO VCSH WAS PUT IN THE FCST THERE UNTIL ABOUT 23Z.
WE CAN NOT RULE OUT A FEW SHOWERS APPROACHING FROM THE W/NW LATE
TODAY FROM CONVECTION THAT MIGHT DEVELOP ACROSS WISCONSIN THIS
AFTERNOON. CONFIDENCE IS TOO LOW AT THIS TIME TO PUT ANYTHING IN
THE FCST FOR THIS.
WINDS WILL DIMINISH A BIT AROUND SUNSET AND REMAIN AROUND 3-5
KNOTS OVERNIGHT. THE MOIST/HUMID AIR MASS WILL ALLOW FOR SOME
LIGHT FOG TO BE POSSIBLE ONCE AGAIN TOWARD DAYBREAK MON.
A WEAK WAVE WILL MOVE INTO THE AREA DURING THE DAY ON MON THIS
WILL PRODUCE ANOTHER THREAT OF A FEW SHOWERS. WE HAVE THESE IN THE
FCST BEGINNING AROUND 14Z AND LASTING THROUGH 18Z.
&&
.MARINE...
ISSUED AT 314 AM EDT SUN JUL 7 2013
SOUTHERLY WINDS ARE EXPECTED TO INCREASE TONIGHT AHEAD OF AN
APPROACHING COLD FRONT. AREAS NORTH OF HOLLAND WILL SEE WAVES
INCREASE TO 2-3 FEET. THIS IS BELOW SMALL CRAFT CRITERIA...BUT THE
LAKE WILL STILL BECOME RATHER ROUGH. WINDS AND WAVES ARE EXPECTED
TO RELAX INTO MONDAY AS THE FRONT MOVES IN.
&&
.HYDROLOGY...
ISSUED AT 314 AM EDT SUN JUL 7 2013
THE WIDELY SCATTERED SHOWERS SHOULD RESULT WITH MOST RIVER BASIN
SEEING AN AVERAGE OF AROUND A QUARTER INCH OF RAIN THROUGH MONDAY
NIGHT...PERHAPS A BIT HIGHER SOUTH OF I-96.
A BETTER CHANCE FOR WIDESPREAD RAINS COMES IN ON TUESDAY. EXPECT
AREAS INLAND FROM THE LAKE AND SOUTH OF HIGHWAY 20 WILL STAND THE
BEST CHANCE OF SEEING A HALF INCH OR MORE OF RAIN. LOCALIZED
HEAVIER RAINS MAY OCCUR AND PRODUCE NUISANCE FLOODING...BUT IN
GENERAL NO HYDRO ISSUES ARE EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...OSTUNO
AVIATION...NJJ
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 1030 AM EDT SUN JUL 7 2013
REMNANTS OF OVERNIGHT MCS CONTINUE TO MOVE IN THE EASTERN U.P. THIS
MORNING AS THEY CONTINUE TO DIMINISH. TRAINING STORMS EARLIER THIS
MORNING DUMPED BETWEEN 2 AND 4 INCHES OF RAIN ACROSS GOGEBIC AND
ONTONAGON COUNTIES BUT AMOUNTS HAVE BEEN MUCH LIGHT FARTHER EAST.
EXPECT A BREAK IN PRECIPITATION INTO THE AFTERNOON HOURS. HIRES
MODELS CONTINUE TO SHOW SCATTERED REDEVELOPMENT OCCURRING ALONG THE
SURFACE TROUGH THIS AFTERNOON AS IT SAGS SOUTHWARD. STILL SOME
UNCERTAINTY THERE AND WILL HAVE TO MONITOR THROUGH THE AFTERNOON
HOURS. WILL ADJUST POP FORECAST ACCORDINGLY WITH THAT THOUGHT
PROCESS IN MIND. WITH MORE CLOUDS TODAY...TEMPS SHOULD ONLY CLIMB
INTO THE UPPER 70S TO AROUND 80.
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN JUL 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA WITH A CUTOFF MID/UPPER LEVEL LOW TO
THE SOUTH OVER IL/IN. A SHORTWAVE TROUGH COMBINED WITH UPPER LEVEL
DIV WITH THE RIGHT ENTRANCE OF A 75 KNOT 250 JET OVER NRN
ONTARIO...AND FAVORABLE 925-700 THETA/E ADVECTION FROM THE UPPER MS
VALLEY SUPPORTED AN AREA OF SHRA/TSRA OVER LAKE SUPERIOR INTO W
UPPER MI AND NW WI WITH THE STRONGEST CONVECTION ON THE WRN END OF
THE PCPN AREA. AT THE SFC...A COLD FRONT HAD GRADUALLY SAGGED TO THE
SOUTH INTO NRN UPPER MI.
TODAY...EXPECT THAT WEAKENING SHRA/TSRA WILL CONTINUE TO SPREAD
THROUGH WRN INTO N CNTRL UPPER MI EARLY...PER RADAR AND SHORT RANGE
MODEL TRENDS...BEFORE THE FORCING ASSOCIATED WITH THE SHRTWV AND LOW
LEVEL INFLOW WEAKENS. BY LATE MORNING INTO THE EARLY
AFTERNOON...THERE MAY BE A LULL IN ANY PCPN BEFORE ADDITIONAL SCT
SHRA/TSRA ALONG THE FRONTAL BOUNDARY REINFORCED BY LAKE SUPERIOR
BREEZE. THERE MAY BE ENOUGH THINNING OR BREAKS IN THE CLOUD COVER
FOR TEMPS TO RECOVER TO NEAR 80...PUSHING MLCAPE VALUES INTO THE
1000-1500 J/KG RANGE. HOWEVER...0-6KM SHEAR VALUES TO NEAR 30 KT
WILL REMAIN MARGINAL FOR STRONGER OR SEVERE ORGANIZED CONVECTION.
THERE MAY STILL BE BRIEF HEAVY RAIN AND GUSTY WINDS WITH TSRA THAT
DEVELOP.
TONIGHT...AS DAYTIME HEATING SUBSIDES AND THE FRONT CONTINUES TO
PUSH TO THE SOUTH...THE REMAINING PCPN SHOULD SHIFT TO THE SOUTH AND
EAST AND DIMINISH. WITH LINGERING LOW LEVEL MOISTURE AND MID LEVEL
DRYING...AREAS OF FOG ARE EXPECTED TO DEVELOP. THERE COULD ALSO BE
SOME DRIZZLE NEAR THE WRN SHORE AS WEAK LOW LEVEL CONV DEVELOPS WITH
MOIST NE FLOW OFF THE LAKE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 505 AM EDT SUN JUL 7 2013
THE SURFACE FRONT WILL BE SOUTH OF THE FORECAST AREA MONDAY
MORNING...WITH WEAK SURFACE RIDGING ACROSS LAKE SUPERIOR. THIS WILL
HELP TO OVERALL DRY THE ATMOSPHERE...HOWEVER IT WILL ALSO ALLOW FOR
WEAK UPSLOPE FLOW IN AREAS NEAR LAKE SUPERIOR. THE NAM AND EVEN THE
GFS SUGGEST A VERY SHALLOW SATURATED LAYER BELOW 1000 FT WHICH WOULD
IMPLY AT LEAST A CHANCE FOR LOW CLOUDS AND DRIZZLE NEAR LAKE
SUPERIOR MONDAY MORNING. HOWEVER...BY AFTERNOON ANY LOW
CLOUD/DRIZZLE SHOULD MIX OUT. WILL ALSO MAINTAIN THE SLIGHT CHANCE
POPS IN THE LAKE BREEZE AREAS OF WESTERN UPPER MICHIGAN AND NEAR
LAKE MICHIGAN. ALTHOUGH THE NWP SUGGESTS A FAIRLY DRY ATMOSPHERE
BEHIND THE FRONT AND BROAD SCALE SUBSIDENCE...THE 850MB FRONT
WILL STALL OUT OVER THE AREA AND INTERIOR INSTABILITY RISES TO
NEARLY 1500 J/KG. NOT TO CONFIDENT THAT ANY SHOWERS/STORMS WILL
OCCUR MONDAY AFTERNOON...BUT ALSO NOT CONFIDENT ENOUGH TO REMOVE THE
MENTION. REGARDLESS...MONDAY WILL BE COOLER AND A LITTLE LESS HUMID
THAN TODAY WITH READINGS NEAR LAKE SUPERIOR DROPPING BACK INTO THE
LOWER-MID 70S.
MONDAY NIGHT SHOULD BE A FAIRLY QUIET NIGHT ACROSS THE AREA AS THE
NEXT LOW PRESSURE SYSTEM DEVELOPS ACROSS THE PLAINS. THE MODELS HAVE
BACKED OFF ANY PCPN FOR THE AREA MONDAY NIGHT...INSTEAD FOCUSING IT
ACROSS MN WHERE THE BETTER LOW LEVEL MOISTURE TRANSPORT AND DEEP
MOISTURE WILL BE LOCATED.
SOME DISAGREEMENT REMAINS REGARDING TIMING OF PRECIPITATION ON
TUESDAY. THERE IS A HINT FROM THE ECMWF AND GFS THAT AN MCS WILL BE
ONGOING TO WEST OF THE AREA IN THE BROAD WARM ADVECTION/ISENTROPIC
LIFT AREA IN SRN MN. THIS LEADS TO MUCH UNCERTAINTY REGARDING
CONVECTIVE EVOLUTION TUE FOR THE AREA. THE MAIN FORCING MECHANISM
TUE AND TUE NIGHT WILL CONTINUE TO BE THE NRN STREAM ENERGY DIVING
OUT OF CANADA AND AMPLIFYING DURING THE DAY...AND HAVE OPTED TO
FOCUS ON THIS FEATURE SIMILAR TO THE NAM SOLUTION. WITH THE BEST
FORCING WITH ENERGY BEING LATE TUE AFTN AND EVENING...HAVE OPTED TO
MAINTAIN THE HIGHEST POPS DURING THIS PERIOD. DEPENDING ON THE
AMOUNT OF DEBRIS CLOUDS...MODEST INSTABILITY IS POSSIBLE ACROSS THE
AREA TUE AFTN/EVENING HELPING TO MAINTAIN THUNDERSTORM DEVELOPMENT
ALONG THE FRONT. CANNOT TOTALLY RULE OUT SOME ORGANIZATION TO THE
STORMS LATER TUESDAY INTO TUESDAY EVENING AS A COUPLED UPPER JET
STRUCTURE DEVELOPS ACROSS THE NRN LAKES IN RESPONSE TO THE WAVE
BECOMING NEGATIVELY TILTED.
THE FRONT MOVES THROUGH THE AREA BY WEDNESDAY MORNING. MAY BE SOME
RESIDUAL WRAP AROUND MOISTURE ACROSS THE AREA IN THE MORNING...BUT
OTHERWISE THE WEATHER SHOULD IMPROVE DURING THE DAY. MODELS IN
EXCELLENT AGREEMENT IN SHOWING BROAD HIGH PRESSURE ACROSS THE UPPER
GREAT LAKES FOR THE END OF THE WEEK WITH RISING HEIGHTS BY THE
WEEKEND. TEMPERATURES WILL BE SEASONABLE THU AND FRIDAY ALTHOUGH
ABOVE NORMAL TEMPS MAY RETURN BY SATURDAY WITH 850MB TEMPS PROGGED
TO RISE TO +16 ACROSS THE WEST. CANNOT RULE OUT SHOWERS SATURDAY
AFTERNOON AS BOTH THE GFS AND ECMWF HINT AS AN UPPER WAVE MOVING
THROUGH THE AREA IN THE WESTERLY FLOW. HOWEVER...AT THIS TIME WILL
OPT TO MAINTAIN A DRY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 130 PM EDT SUN JUL 7 2013
SURFACE TROUGH WILL DROP SLOWLY SOUTHWARD ACROSS UPPER MICHIGAN THIS
AFTERNOON SHIFTING WINDS FROM THE SOUTHWEST TO THE NORTH. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP ALONG THIS BOUNDARY AS
IT MOVES SOUTHWARD BUT ANTICIPATED AREAL COVERAGE IS NOT ENOUGH TO
INCLUDE A MENTION AT THE TAF SITES. LOW LEVEL MOISTURE WILL REMAIN
AFTER THE TROUGH PASSES AND WITH SUBSTANTIAL MID LEVEL DRYING EXPECT
FOG AND EVEN SOME DRIZZLE TO DEVELOP AT ALL THREE FORECAST LOCATIONS
LOWERING CONDITIONS TO VLIFR NEAR AIRPORT MINIMUMS FOR THE OVERNIGHT
AND EARLY MONDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN JUL 7 2013
GIVEN EARLY SHIP OBSERVATIONS OF ZERO VISIBILITY OVER WESTERN LAKE
SUPERIOR AND VERY HUMID AIRMASS OVER CHILLY WATER FOLLOWING SOME
SHOWERS...A DENSE FOG ADVISORY WILL REMAIN IN EFFECT THIS MORNING
FOR THE WEST HALF OF LAKE SUPERIOR. SOME DRYING ON SUNDAY
AFTERNOON FOLLOWING A COLD FRONTAL PASSAGE SHOULD DISSIPATE THE
THICKEST FOG.
WINDS WILL REMAIN BELOW 15 KT ACROSS LAKE SUPERIOR THROUGH TUESDAY
AS A WEAK SURFACE TROUGH DROPS SOUTHWARD ACROSS THE LAKE FOLLOWED BY
AN AREA OF HIGH PRESSURE. WITH SHOWERS AND THUNDERSTORMS EARLY TODAY
AND ADDITIONAL SCT SHRA/TSRA POSSIBLE THIS AFTERNOON...AREAS
OF FOG WILL CONTINUE ACROSS THE LAKE. AS ANOTHER LOW DEVELOPS OVER
THE PLAINS ON TUESDAY AND APPROACHES LAKE SUPERIOR ON
WEDNESDAY....NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL BE POSSIBLE
BEHIND FOR A TIME WEDNESDAY AND WEDNESDAY NIGHT. A SURFACE HIGH
MOVING OVER THE UPPER LAKES LATE IN THE WEEK WILL ALLOW LIGHT WINDS
TO RETURN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MZ
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1050 AM EDT SUN JUL 7 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 314 AM EDT SUN JUL 7 2013
THE WEATHER PATTERN WILL CHANGE LITTLE OVER THE NEXT FEW DAYS. IT
WILL REMAIN WARM AND HUMID WITH HIGHS IN THE MID TO UPPER 80S. WE
WILL ALSO SEE SCATTERED SHOWERS AND STORMS. THE BEST CHANCE OF
PRECIPITATION IN THE SHORT TERM WILL COME LATE TONIGHT INTO MONDAY
MORNING...WITH ANOTHER GOOD CHANCE ON TUESDAY.
THE SHOWERS AND STORMS SHOULD LINGER INTO WEDNESDAY...BUT THEN THE
LATTER HALF OF THE WEEK LOOKS DRY. DAYTIME TEMPERATURES WILL
LARGELY BE IN THE 80 TO 85 DEGREE RANGE FROM MID WEEK INTO NEXT
WEEKEND.
&&
.UPDATE...
ISSUED AT 1048 AM EDT SUN JUL 7 2013
I UPDATED THE ZONE FORECAST TO INCREASE THE CHANCE FOR SHOWERS
INTO EARLY THIS AFTERNOON OVER THE EASTERN SECTIONS OUR OUR CWA
AND TO DECREASE THE FORECAST HIGH A TOUCH SINCE THERE IS A
CONSIDERABLE AMOUNT OF MID CLOUD AROUND.
THE 700 MB LOW IS NEARLY OVERHEAD OF GRAND RAPIDS AT 9 AM BASED ON
RADAR DATA SHOWING THE SHOWERS PINWHEELING AROUND GRAND RAPIDS.
THIS IS ALSO SUPPORTED BY BOTH VISIBLE SATELLITE LOOPS AND RAP
MODEL 12Z FORECAST. THAT SUPPORTS THE SHOWERS OVER THE INFLOW
SECTION OF THE LOW...EAST OF GRR ACTUALLY WITH A DEFORMATION ZONE
FEATURE FROM NORTHERN KENT COUNTY INTO GRATIOT COUNTY. NOT MUCH
THUNDER HAPPENING THOUGH. WHILE THAT WAS HAPPENING THERE IS AN MCS
OVER THE WESTERN UPPER PENINSULA OF MICHIGAN THAT SEEMS TO BE
WEAKENING AND BUILDING TOWARD THE SOUTHEAST.
WITH THE 700 MB LOW WEAKENING AND MOVING INTO EASTERN LOWER
MICHIGAN THIS AFTERNOON THAT WOULD PUT WESTERN LOWER MICHIGAN IN
NORTHWEST SUBSIDING FLOW ON THE WEST SIDE OF THE LOW. NOT A GOOD
THING IF ONE WANTS SHOWERS. SO MY SPIN IS THE CLOUDS AND SHOWERS
WILL GRADUALLY MOVE EAST OF SOUTHWEST LOWER MICHIGAN DURING THE
AFTERNOON. WITH THE SUBSIDENCE ON THE WEST SIDE OF THE SYSTEM I DO
NOT SEE MUCH THREAT FOR CONVECTION TO DEVELOP SO I HAVE VERY LOW
POPS WEST OF US-131 AFTER 1 PM (WEST WINDS OFF LAKE MICHIGAN DO
NOT HELP THE CAUSE FOR CONVECTION MUCH EITHER).THIS IS STRONGLY
SUPPORTED BY RAP MODEL SOUNDING WITH SHOW A VERY DRY LOOKING
SOUNDING FROM THE SURFACE THROUGH 300 MB BY 21Z NEAR GRR.
IT IS MORE MOIST ON THE RAP SOUNDING IN THE LAN/JXN AREA THIS
AFTERNOON WITH NEAR 1800 J/KG OF CAPE BUT I WITH GENERIC WEST WINDS
THROUGH 700 MB BY 21Z I SEE LITTLE REASON FOR MUCH SURFACE
CONVERGENCE SO I AM STILL NOT TO EXITED ABOUT STORM POTENTL EVEN THERE.
WE WILL HAVE TO WATCH WHAT HAPPENS WITH THE MCS OVER THE WESTERN
UPPER PENINSULA FOR THIS EVENING BUT EVEN THERE... THE LOW LEVEL
JET IS LARGELY IN WISCONSIN THIS EVENING AND THE BEST JET DYNAMICS
ARE OVER NORTHERN WI AND THE MICHIGAN UP SO I BELIEVE LITTLE WILL
HAPPEN OVER WESTERN LOWER MICHIGAN TONIGHT EITHER.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 314 AM EDT SUN JUL 7 2013
WIDELY SCATTERED SHOWERS AND STORMS WILL CONTINUE THROUGH THE SHORT
TERM. HOWEVER THE PRECIPITATION SHOULD BECOME MORE WIDESPREAD LATE
TONIGHT INTO MONDAY MORNING...AND THEN AGAIN ON TUESDAY. IT WILL
REMAIN WARM AND HUMID THROUGH TUESDAY.
AN UPPER LOW WAS OVER SE IL THIS MORNING AND IT WAS DRIFTING NE.
THIS WILL BRING THE CENTER OF THE LOW TO NE INDIANA BY THIS
AFTERNOON. THIS IS FURTHER NORTH THAN WHAT PREVIOUS MODELS HAVE
BEEN SHOWING. FOR THE PAST FEW DAYS THERE HAS BEEN DAYTIME
THUNDERSTORMS NEAR AND AROUND THIS LOW. HOWEVER THE COVERAGE OF THE
PCPN STILL WARRANTS 30/40 POPS. ALSO BY THE END OF THE DAY A COLD
FRONT WILL BE MOVING ACROSS WI. THIS COULD BRING ISOLATED PCPN INTO
THE NW CWA AND 20/30 POPS WILL BE CARRIED OVER THE NW CWA.
DECENT SET UP FOR AN MCS TO ROLL ALONG THE FRONT TO OUR WEST TONIGHT
WITH THE ASSISTANCE OF A LOW LEVEL JET. SEEMS LIKE THIS MAY TRACK
NEAR THE MI/IN BORDER LATE TONIGHT IN A WEAKENING STATE. ITS
DOUBTFUL THAT SEVERE WILL OCCUR AS THIS COMPLEX WILL BE RUNNING AWAY
FROM THE BEST INSTABILITY AND JET SUPPORT BY THE TIME IT REACHES
US...BUT WILL CARRY 40/50 POPS SOUTH OF I-96.
EXPECT SOMEWHAT LESS CONVECTION INTO MONDAY AFTERNOON AND MONDAY
NIGHT. THE FRONT EASES INTO THE REGION...BUT IT WASHES OUT OVER THE
NORTHERN OR CENTRAL CWA. THIS MAY SUPPORT SOME WIDELY SCATTERED
STORMS BUT WITHOUT A FOCUSED JET THESE SHOULD NOT BE SEVERE.
ANOTHER UP TICK IN THE STORM ACTIVITY IS EXPECTED INTO TUESDAY.
ANOTHER COLD FRONT WILL BE CROSSING WI WITH A STRONG LOW LEVEL JET
ALONG IT. THE CONVERGENCE FROM THIS JET SHOULD REACH US BY LATE
AFTERNOON WHEN THE CHANCE OF ORGANIZED/SEVERE STORMS WILL BE
POSSIBLE. HAVE INCREASED POPS TO LIKELY SOUTH OF I-96 AS THIS IS
WHERE THE LLJ IS PROGGED TO BE NOSING INTO.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 335 AM EDT SUN JUL 7 2013
BEST CHANCE OF RAIN IN THE EXTENDED WILL BE TUESDAY NIGHT INTO
EARLY WEDNESDAY AS UPPER TROUGH AXIS AND SFC LOW MOVES THROUGH.
PLENTY OF MOISTURE AVAILABLE AND MCS DEVELOPMENT IS POSSIBLE TUESDAY
NIGHT INTO WEDNESDAY MORNING WITH HEAVY RAIN THREAT. MODELS HAVE
TRENDED TO A LESS AMPLIFIED TROUGH AND WEAKER SHEAR PROFILES SO
SEVERE THREAT NOW SEEMS TO BE DIMINISHED.
KEPT THE LATTER PART OF THE WEEK DRY AS SFC HIGH IS IN PLACE AND DRY
SOUNDINGS RULE FROM LATE WEDNESDAY THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 745 AM EDT SUN JUL 7 2013
SOME AREAS OF MVFR IN LIGHT FOG WITH ISOLATED IFR LOW STRATUS
EARLY THIS MORNING WILL IMPROVE TO VFR BY 14Z. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THROUGH THE DAY.
WINDS WILL BE SOUTHWEST AOB 10 KNOTS.
&&
.MARINE...
ISSUED AT 314 AM EDT SUN JUL 7 2013
SOUTHERLY WINDS ARE EXPECTED TO INCREASE TONIGHT AHEAD OF AN
APPROACHING COLD FRONT. AREAS NORTH OF HOLLAND WILL SEE WAVES
INCREASE TO 2-3 FEET. THIS IS BELOW SMALL CRAFT CRITERIA...BUT THE
LAKE WILL STILL BECOME RATHER ROUGH. WINDS AND WAVES ARE EXPECTED
TO RELAX INTO MONDAY AS THE FRONT MOVES IN.
&&
.HYDROLOGY...
ISSUED AT 314 AM EDT SUN JUL 7 2013
THE WIDELY SCATTERED SHOWERS SHOULD RESULT WITH MOST RIVER BASIN
SEEING AN AVERAGE OF AROUND A QUARTER INCH OF RAIN THROUGH MONDAY
NIGHT...PERHAPS A BIT HIGHER SOUTH OF I-96.
A BETTER CHANCE FOR WIDESPREAD RAINS COMES IN ON TUESDAY. EXPECT
AREAS INLAND FROM THE LAKE AND SOUTH OF HIGHWAY 20 WILL STAND THE
BEST CHANCE OF SEEING A HALF INCH OR MORE OF RAIN. LOCALIZED
HEAVIER RAINS MAY OCCUR AND PRODUCE NUISANCE FLOODING...BUT IN
GENERAL NO HYDRO ISSUES ARE EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1030 AM EDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 1030 AM EDT SUN JUL 7 2013
REMNANTS OF OVERNIGHT MCS CONTINUE TO MOVE IN THE EASTERN U.P. THIS
MORNING AS THEY CONTINUE TO DIMINISH. TRAINING STORMS EARLIER THIS
MORNING DUMPED BETWEEN 2 AND 4 INCHES OF RAIN ACROSS GOGEBIC AND
ONTONAGON COUNTIES BUT AMOUNTS HAVE BEEN MUCH LIGHT FARTHER EAST.
EXPECT A BREAK IN PRECIPITATION INTO THE AFTERNOON HOURS. HIRES
MODELS CONTINUE TO SHOW SCATTERED REDEVELOPMENT OCCURRING ALONG THE
SURFACE TROUGH THIS AFTERNOON AS IT SAGS SOUTHWARD. STILL SOME
UNCERTAINTY THERE AND WILL HAVE TO MONITOR THROUGH THE AFTERNOON
HOURS. WILL ADJUST POP FORECAST ACCORDINGLY WITH THAT THOUGHT
PROCESS IN MIND. WITH MORE CLOUDS TODAY...TEMPS SHOULD ONLY CLIMB
INTO THE UPPER 70S TO AROUND 80.
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN JUL 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA WITH A CUTOFF MID/UPPER LEVEL LOW TO
THE SOUTH OVER IL/IN. A SHORTWAVE TROUGH COMBINED WITH UPPER LEVEL
DIV WITH THE RIGHT ENTRANCE OF A 75 KNOT 250 JET OVER NRN
ONTARIO...AND FAVORABLE 925-700 THETA/E ADVECTION FROM THE UPPER MS
VALLEY SUPPORTED AN AREA OF SHRA/TSRA OVER LAKE SUPERIOR INTO W
UPPER MI AND NW WI WITH THE STRONGEST CONVECTION ON THE WRN END OF
THE PCPN AREA. AT THE SFC...A COLD FRONT HAD GRADUALLY SAGGED TO THE
SOUTH INTO NRN UPPER MI.
TODAY...EXPECT THAT WEAKENING SHRA/TSRA WILL CONTINUE TO SPREAD
THROUGH WRN INTO N CNTRL UPPER MI EARLY...PER RADAR AND SHORT RANGE
MODEL TRENDS...BEFORE THE FORCING ASSOCIATED WITH THE SHRTWV AND LOW
LEVEL INFLOW WEAKENS. BY LATE MORNING INTO THE EARLY
AFTERNOON...THERE MAY BE A LULL IN ANY PCPN BEFORE ADDITIONAL SCT
SHRA/TSRA ALONG THE FRONTAL BOUNDARY REINFORCED BY LAKE SUPERIOR
BREEZE. THERE MAY BE ENOUGH THINNING OR BREAKS IN THE CLOUD COVER
FOR TEMPS TO RECOVER TO NEAR 80...PUSHING MLCAPE VALUES INTO THE
1000-1500 J/KG RANGE. HOWEVER...0-6KM SHEAR VALUES TO NEAR 30 KT
WILL REMAIN MARGINAL FOR STRONGER OR SEVERE ORGANIZED CONVECTION.
THERE MAY STILL BE BRIEF HEAVY RAIN AND GUSTY WINDS WITH TSRA THAT
DEVELOP.
TONIGHT...AS DAYTIME HEATING SUBSIDES AND THE FRONT CONTINUES TO
PUSH TO THE SOUTH...THE REMAINING PCPN SHOULD SHIFT TO THE SOUTH AND
EAST AND DIMINISH. WITH LINGERING LOW LEVEL MOISTURE AND MID LEVEL
DRYING...AREAS OF FOG ARE EXPECTED TO DEVELOP. THERE COULD ALSO BE
SOME DRIZZLE NEAR THE WRN SHORE AS WEAK LOW LEVEL CONV DEVELOPS WITH
MOIST NE FLOW OFF THE LAKE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 505 AM EDT SUN JUL 7 2013
THE SURFACE FRONT WILL BE SOUTH OF THE FORECAST AREA MONDAY
MORNING...WITH WEAK SURFACE RIDGING ACROSS LAKE SUPERIOR. THIS WILL
HELP TO OVERALL DRY THE ATMOSPHERE...HOWEVER IT WILL ALSO ALLOW FOR
WEAK UPSLOPE FLOW IN AREAS NEAR LAKE SUPERIOR. THE NAM AND EVEN THE
GFS SUGGEST A VERY SHALLOW SATURATED LAYER BELOW 1000 FT WHICH WOULD
IMPLY AT LEAST A CHANCE FOR LOW CLOUDS AND DRIZZLE NEAR LAKE
SUPERIOR MONDAY MORNING. HOWEVER...BY AFTERNOON ANY LOW
CLOUD/DRIZZLE SHOULD MIX OUT. WILL ALSO MAINTAIN THE SLIGHT CHANCE
POPS IN THE LAKE BREEZE AREAS OF WESTERN UPPER MICHIGAN AND NEAR
LAKE MICHIGAN. ALTHOUGH THE NWP SUGGESTS A FAIRLY DRY ATMOSPHERE
BEHIND THE FRONT AND BROAD SCALE SUBSIDENCE...THE 850MB FRONT
WILL STALL OUT OVER THE AREA AND INTERIOR INSTABILITY RISES TO
NEARLY 1500 J/KG. NOT TO CONFIDENT THAT ANY SHOWERS/STORMS WILL
OCCUR MONDAY AFTERNOON...BUT ALSO NOT CONFIDENT ENOUGH TO REMOVE THE
MENTION. REGARDLESS...MONDAY WILL BE COOLER AND A LITTLE LESS HUMID
THAN TODAY WITH READINGS NEAR LAKE SUPERIOR DROPPING BACK INTO THE
LOWER-MID 70S.
MONDAY NIGHT SHOULD BE A FAIRLY QUIET NIGHT ACROSS THE AREA AS THE
NEXT LOW PRESSURE SYSTEM DEVELOPS ACROSS THE PLAINS. THE MODELS HAVE
BACKED OFF ANY PCPN FOR THE AREA MONDAY NIGHT...INSTEAD FOCUSING IT
ACROSS MN WHERE THE BETTER LOW LEVEL MOISTURE TRANSPORT AND DEEP
MOISTURE WILL BE LOCATED.
SOME DISAGREEMENT REMAINS REGARDING TIMING OF PRECIPITATION ON
TUESDAY. THERE IS A HINT FROM THE ECMWF AND GFS THAT AN MCS WILL BE
ONGOING TO WEST OF THE AREA IN THE BROAD WARM ADVECTION/ISENTROPIC
LIFT AREA IN SRN MN. THIS LEADS TO MUCH UNCERTAINTY REGARDING
CONVECTIVE EVOLUTION TUE FOR THE AREA. THE MAIN FORCING MECHANISM
TUE AND TUE NIGHT WILL CONTINUE TO BE THE NRN STREAM ENERGY DIVING
OUT OF CANADA AND AMPLIFYING DURING THE DAY...AND HAVE OPTED TO
FOCUS ON THIS FEATURE SIMILAR TO THE NAM SOLUTION. WITH THE BEST
FORCING WITH ENERGY BEING LATE TUE AFTN AND EVENING...HAVE OPTED TO
MAINTAIN THE HIGHEST POPS DURING THIS PERIOD. DEPENDING ON THE
AMOUNT OF DEBRIS CLOUDS...MODEST INSTABILITY IS POSSIBLE ACROSS THE
AREA TUE AFTN/EVENING HELPING TO MAINTAIN THUNDERSTORM DEVELOPMENT
ALONG THE FRONT. CANNOT TOTALLY RULE OUT SOME ORGANIZATION TO THE
STORMS LATER TUESDAY INTO TUESDAY EVENING AS A COUPLED UPPER JET
STRUCTURE DEVELOPS ACROSS THE NRN LAKES IN RESPONSE TO THE WAVE
BECOMING NEGATIVELY TILTED.
THE FRONT MOVES THROUGH THE AREA BY WEDNESDAY MORNING. MAY BE SOME
RESIDUAL WRAP AROUND MOISTURE ACROSS THE AREA IN THE MORNING...BUT
OTHERWISE THE WEATHER SHOULD IMPROVE DURING THE DAY. MODELS IN
EXCELLENT AGREEMENT IN SHOWING BROAD HIGH PRESSURE ACROSS THE UPPER
GREAT LAKES FOR THE END OF THE WEEK WITH RISING HEIGHTS BY THE
WEEKEND. TEMPERATURES WILL BE SEASONABLE THU AND FRIDAY ALTHOUGH
ABOVE NORMAL TEMPS MAY RETURN BY SATURDAY WITH 850MB TEMPS PROGGED
TO RISE TO +16 ACROSS THE WEST. CANNOT RULE OUT SHOWERS SATURDAY
AFTERNOON AS BOTH THE GFS AND ECMWF HINT AS AN UPPER WAVE MOVING
THROUGH THE AREA IN THE WESTERLY FLOW. HOWEVER...AT THIS TIME WILL
OPT TO MAINTAIN A DRY FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 747 AM EDT SUN JUL 7 2013
AN AREA OF SHRA/TSRA OVER WESTERN UPPER MI WILL DEPART FROM IWD AND
CMX EARLY BUT WILL IMPACT SAW THROUGH MID MORNING WITH MAINLY MVFR
CONDITIONS. DAYTIME HEATING AND MIXING WILL BRING IMPROVEMENT TO
MAINLY VFR CONDITIONS BY THIS AFTERNOON. SCT SHRA/TSRA MAY REDEVELOP
THIS AFTERNOON. CONFIDENCE IN COVERAGE/TIMING OF ANY TSTMS WAS LOW
AND NOT INCLUDED AT THIS TIME. ABUNDANT LOW LEVEL MOISTURE WILL
REMAIN IN PLACE TONIGHT AS THE MID LEVELS DRY ALLOWING FOG TO
DEVELOP OVERNIGHT WHICH MAY DROP CONDITIONS TO VLIFR NEAR AIRPORT
MINIMUMS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN JUL 7 2013
GIVEN EARLY SHIP OBSERVATIONS OF ZERO VISIBILITY OVER WESTERN LAKE
SUPERIOR AND VERY HUMID AIRMASS OVER CHILLY WATER FOLLOWING SOME
SHOWERS...A DENSE FOG ADVISORY WILL REMAIN IN EFFECT THIS MORNING
FOR THE WEST HALF OF LAKE SUPERIOR. SOME DRYING ON SUNDAY
AFTERNOON FOLLOWING A COLD FRONTAL PASSAGE SHOULD DISSIPATE THE
THICKEST FOG.
WINDS WILL REMAIN BELOW 15 KT ACROSS LAKE SUPERIOR THROUGH TUESDAY
AS A WEAK SURFACE TROUGH DROPS SOUTHWARD ACROSS THE LAKE FOLLOWED BY
AN AREA OF HIGH PRESSURE. WITH SHOWERS AND THUNDERSTORMS EARLY TODAY
AND ADDITIONAL SCT SHRA/TSRA POSSIBLE THIS AFTERNOON...AREAS
OF FOG WILL CONTINUE ACROSS THE LAKE. AS ANOTHER LOW DEVELOPS OVER
THE PLAINS ON TUESDAY AND APPROACHES LAKE SUPERIOR ON
WEDNESDAY....NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL BE POSSIBLE
BEHIND FOR A TIME WEDNESDAY AND WEDNESDAY NIGHT. A SURFACE HIGH
MOVING OVER THE UPPER LAKES LATE IN THE WEEK WILL ALLOW LIGHT WINDS
TO RETURN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MZ
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
748 AM EDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN JUL 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA WITH A CUTOFF MID/UPPER LEVEL LOW TO
THE SOUTH OVER IL/IN. A SHORTWAVE TROUGH COMBINED WITH UPPER LEVEL
DIV WITH THE RIGH ENTRANCE OF A 75 KNOT 250 JET OVER NRN ONTARIO...AND
FAVORABLE 925-700 THETA/E ADVECTION FROM THE UPPER MS VALLEY
SUPPORTED AN AREA OF SHRA/TSRA OVER LAKE SUPERIOR INTO W UPPER MI
AND NW WI WITH THE STRONGEST CONVECTION ON THE WRN END OF THE PCPN
AREA. AT THE SFC...A COLD FRONT HAD GRADUALLY SAGGED TO THE SOUTH INTO
NRN UPPER MI.
TODAY...EXPECT THAT WEAKENING SHRA/TSRA WILL CONTINUE TO SPREAD THROUGH
WRN INTO N CNTRL UPPER MI EARLY...PER RADAR AND SHORT RANGE MODEL
TRENDS...BEFORE THE FORCING ASSOCIATED WITH THE SHRTWV AND LOW LEVEL
INFLOW WEAKENS. BY LATE MORNING INTO THE EARLY AFTERNOON...THERE MAY
BE A LULL IN ANY PCPN BEFORE ADDITIONAL SCT SHRA/TSRA ALONG THE
FRONTAL BOUNDARY REINFORCED BY LAKE SUPERIOR BREEZE. THERE MAY BE
ENOUGH THINNING OR BREAKS IN THE CLOUD COVER FOR TEMPS TO RECOVER TO
NEAR 80...PUSHING MLCAPE VALUES INTO THE 1000-1500 J/KG RANGE.
HOWEVER...0-6KM SHEAR VALUES TO NEAR 30 KT WILL REMAIN MARGINAL FOR
STRONGER OR SEVERE ORGANIZED CONVECTION. THERE MAY STILL BE BRIEF HEAVY
RAIN AND GUSTY WINDS WITH TSRA THAT DEVELOP.
TONIGHT...AS DAYTIME HEATING SUBSIDES AND THE FRONT CONTINUES TO
PUSH TO THE SOUTH...THE REMAINING PCPN SHOULD SHIFT TO THE SOUTH AND
EAST AND DIMINISH. WITH LINGERING LOW LEVEL MOISTURE AND MID LEVEL
DRYING...AREAS OF FOG ARE EXPECTED TO DEVELOP. THERE COULD ALSO BE
SOME DRIZZLE NEAR THE WRN SHORE AS WEAK LOW LEVEL CONV DEVELOPS WITH
MOIST NE FLOW OFF THE LAKE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 505 AM EDT SUN JUL 7 2013
THE SURFACE FRONT WILL BE SOUTH OF THE FORECAST AREA MONDAY
MORNING...WITH WEAK SURFACE RIDGING ACROSS LAKE SUPERIOR. THIS WILL
HELP TO OVERALL DRY THE ATMOSPHERE...HOWEVER IT WILL ALSO ALLOW FOR
WEAK UPSLOPE FLOW IN AREAS NEAR LAKE SUPERIOR. THE NAM AND EVEN THE
GFS SUGGEST A VERY SHALLOW SATURATED LAYER BELOW 1000 FT WHICH WOULD
IMPLY AT LEAST A CHANCE FOR LOW CLOUDS AND DRIZZLE NEAR LAKE
SUPERIOR MONDAY MORNING. HOWEVER...BY AFTERNOON ANY LOW
CLOUD/DRIZZLE SHOULD MIX OUT. WILL ALSO MAINTAIN THE SLIGHT CHANCE
POPS IN THE LAKE BREEZE AREAS OF WESTERN UPPER MICHIGAN AND NEAR
LAKE MICHIGAN. ALTHOUGH THE NWP SUGGESTS A FAIRLY DRY ATMOSPHERE
BEHIND THE FRONT AND BROAD SCALE SUBSIDENCE...THE 850MB FRONT
WILL STALL OUT OVER THE AREA AND INTERIOR INSTABILITY RISES TO
NEARLY 1500 J/KG. NOT TO CONFIDENT THAT ANY SHOWERS/STORMS WILL
OCCUR MONDAY AFTERNOON...BUT ALSO NOT CONFIDENT ENOUGH TO REMOVE THE
MENTION. REGARDLESS...MONDAY WILL BE COOLER AND A LITTLE LESS HUMID
THAN TODAY WITH READINGS NEAR LAKE SUPERIOR DROPPING BACK INTO THE
LOWER-MID 70S.
MONDAY NIGHT SHOULD BE A FAIRLY QUIET NIGHT ACROSS THE AREA AS THE
NEXT LOW PRESSURE SYSTEM DEVELOPS ACROSS THE PLAINS. THE MODELS HAVE
BACKED OFF ANY PCPN FOR THE AREA MONDAY NIGHT...INSTEAD FOCUSING IT
ACROSS MN WHERE THE BETTER LOW LEVEL MOISTURE TRANSPORT AND DEEP
MOISTURE WILL BE LOCATED.
SOME DISAGREEMENT REMAINS REGARDING TIMING OF PRECIPITATION ON
TUESDAY. THERE IS A HINT FROM THE ECMWF AND GFS THAT AN MCS WILL BE
ONGOING TO WEST OF THE AREA IN THE BROAD WARM ADVECTION/ISENTROPIC
LIFT AREA IN SRN MN. THIS LEADS TO MUCH UNCERTAINTY REGARDING
CONVECTIVE EVOLUTION TUE FOR THE AREA. THE MAIN FORCING MECHANISM
TUE AND TUE NIGHT WILL CONTINUE TO BE THE NRN STREAM ENERGY DIVING
OUT OF CANADA AND AMPLIFYING DURING THE DAY...AND HAVE OPTED TO
FOCUS ON THIS FEATURE SIMILAR TO THE NAM SOLUTION. WITH THE BEST
FORCING WITH ENERGY BEING LATE TUE AFTN AND EVENING...HAVE OPTED TO
MAINTAIN THE HIGHEST POPS DURING THIS PERIOD. DEPENDING ON THE
AMOUNT OF DEBRIS CLOUDS...MODEST INSTABILITY IS POSSIBLE ACROSS THE
AREA TUE AFTN/EVENING HELPING TO MAINTAIN THUNDERSTORM DEVELOPMENT
ALONG THE FRONT. CANNOT TOTALLY RULE OUT SOME ORGANIZATION TO THE
STORMS LATER TUESDAY INTO TUESDAY EVENING AS A COUPLED UPPER JET
STRUCTURE DEVELOPS ACROSS THE NRN LAKES IN RESPONSE TO THE WAVE
BECOMING NEGATIVELY TILTED.
THE FRONT MOVES THROUGH THE AREA BY WEDNEDAY MORNING. MAY BE SOME
RESIDUAL WRAP AROUND MOISTURE ACROSS THE AREA IN THE MORNING...BUT
OTHERWISE THE WEATHER SHOULD IMPROVE DURING THE DAY. MODELS IN
EXCELLENT AGREEMENT IN SHOWING BROAD HIGH PRESSURE ACROSS THE UPPER
GREAT LAKES FOR THE END OF THE WEEK WITH RISING HEIGHTS BY THE
WEEKEND. TEMPERATURES WILL BE SEASONABLE THU AND FRIDAY ALTHOUGH
ABOVE NORMAL TEMPS MAY RETURN BY SATURDAY WITH 850MB TEMPS PROGGED
TO RISE TO +16 ACROSS THE WEST. CANNOT RULE OUT SHOWERS SATURDAY
AFTERNOON AS BOTH THE GFS AND ECMWF HINT AS AN UPPER WAVE MOVING
THROUGH THE AREA IN THE WESTERLY FLOW. HOWEVER...AT THIS TIME WILL
OPT TO MAINTAIN A DRY FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 747 AM EDT SUN JUL 7 2013
AN AREA OF SHRA/TSRA OVER WESTERN UPPER MI WILL DEPART FROM IWD AND
CMX EARLY BUT WILL IMPACT SAW THROUGH MID MORNING WITH MAINLY MVFR
CONDITIONS. DAYTIME HEATING AND MIXING WILL BRING IMPROVEMENT TO
MAINLY VFR CONDITIONS BY THIS AFTERNOON. SCT SHRA/TSRA MAY REDEVELOP
THIS AFTERNOON. CONFIDENCE IN COVERAGE/TIMING OF ANY TSTMS WAS LOW
AND NOT INCLUDED AT THIS TIME. ABUNDANT LOW LEVEL MOISTURE WILL
REMAIN IN PLACE TONIGHT AS THE MID LEVELS DRY ALLOWING FOG TO
DEVELOP OVERNIGHT WHICH MAY DROP CONDITIONS TO VLIFR NEAR AIRPORT
MINIMUMS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN JUL 7 2013
GIVEN EARLY SHIP OBSERVATIONS OF ZERO VISIBILITY OVER WESTERN LAKE
SUPERIOR AND VERY HUMID AIRMASS OVER CHILLY WATER FOLLOWING SOME
SHOWERS...A DENSE FOG ADVISORY WILL REMAIN IN EFFECT THIS MORNING
FOR THE WEST HALF OF LAKE SUPERIOR. SOME DRYING ON SUNDAY
AFTERNOON FOLLOWING A COLD FRONTAL PASSAGE SHOULD DISSIPATE THE
THICKEST FOG.
WINDS WILL REMAIN BELOW 15 KT ACROSS LAKE SUPERIOR THROUGH TUESDAY
AS A WEAK SURFACE TROUGH DROPS SOUTHWARD ACROSS THE LAKE FOLLOWED BY
AN AREA OF HIGH PRESSURE. WITH SHOWERS AND THUNDERSTORMS EARLY TODAY
AND ADDITIONAL SCT SHRA/TSRA POSSIBLE THIS AFTERNOON...AREAS
OF FOG WILL CONTINUE ACROSS THE LAKE. AS ANOTHER LOW DEVELOPS OVER
THE PLAINS ON TUESDAY AND APPROACHES LAKE SUPERIOR ON
WEDNESDAY....NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL BE POSSIBLE
BEHIND FOR A TIME WEDNESDAY AND WEDNESDAY NIGHT. A SURFACE HIGH
MOVING OVER THE UPPER LAKES LATE IN THE WEEK WILL ALLOW LIGHT WINDS
TO RETURN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 505 AM EDT SUN JUL 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA WITH A CUTOFF MID/UPPER LEVEL LOW TO
THE SOUTH OVER IL/IN. A SHORTWAVE TROUGH COMBINED WITH UPPER LEVEL
DIV WITH THE RIGH ENTRANCE OF A 75 KNOT 250 JET OVER NRN ONTARIO...AND
FAVORABLE 925-700 THETA/E ADVECTION FROM THE UPPER MS VALLEY
SUPPORTED AN AREA OF SHRA/TSRA OVER LAKE SUPERIOR INTO W UPPER MI
AND NW WI WITH THE STRONGEST CONVECTION ON THE WRN END OF THE PCPN
AREA. AT THE SFC...A COLD FRONT HAD GRADUALLY SAGGED TO THE SOUTH INTO
NRN UPPER MI.
TODAY...EXPECT THAT WEAKENING SHRA/TSRA WILL CONTINUE TO SPREAD THROUGH
WRN INTO N CNTRL UPPER MI EARLY...PER RADAR AND SHORT RANGE MODEL
TRENDS...BEFORE THE FORCING ASSOCIATED WITH THE SHRTWV AND LOW LEVEL
INFLOW WEAKENS. BY LATE MORNING INTO THE EARLY AFTERNOON...THERE MAY
BE A LULL IN ANY PCPN BEFORE ADDITIONAL SCT SHRA/TSRA ALONG THE
FRONTAL BOUNDARY REINFORCED BY LAKE SUPERIOR BREEZE. THERE MAY BE
ENOUGH THINNING OR BREAKS IN THE CLOUD COVER FOR TEMPS TO RECOVER TO
NEAR 80...PUSHING MLCAPE VALUES INTO THE 1000-1500 J/KG RANGE.
HOWEVER...0-6KM SHEAR VALUES TO NEAR 30 KT WILL REMAIN MARGINAL FOR
STRONGER OR SEVERE ORGANIZED CONVECTION. THERE MAY STILL BE BRIEF HEAVY
RAIN AND GUSTY WINDS WITH TSRA THAT DEVELOP.
TONIGHT...AS DAYTIME HEATING SUBSIDES AND THE FRONT CONTINUES TO
PUSH TO THE SOUTH...THE REMAINING PCPN SHOULD SHIFT TO THE SOUTH AND
EAST AND DIMINISH. WITH LINGERING LOW LEVEL MOISTURE AND MID LEVEL
DRYING...AREAS OF FOG ARE EXPECTED TO DEVELOP. THERE COULD ALSO BE
SOME DRIZZLE NEAR THE WRN SHORE AS WEAK LOW LEVEL CONV DEVELOPS WITH
MOIST NE FLOW OFF THE LAKE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 505 AM EDT SUN JUL 7 2013
THE SURFACE FRONT WILL BE SOUTH OF THE FORECAST AREA MONDAY
MORNING...WITH WEAK SURFACE RIDGING ACROSS LAKE SUPERIOR. THIS WILL
HELP TO OVERALL DRY THE ATMOSPHERE...HOWEVER IT WILL ALSO ALLOW FOR
WEAK UPSLOPE FLOW IN AREAS NEAR LAKE SUPERIOR. THE NAM AND EVEN THE
GFS SUGGEST A VERY SHALLOW SATURATED LAYER BELOW 1000 FT WHICH WOULD
IMPLY AT LEAST A CHANCE FOR LOW CLOUDS AND DRIZZLE NEAR LAKE
SUPERIOR MONDAY MORNING. HOWEVER...BY AFTERNOON ANY LOW
CLOUD/DRIZZLE SHOULD MIX OUT. WILL ALSO MAINTAIN THE SLIGHT CHANCE
POPS IN THE LAKE BREEZE AREAS OF WESTERN UPPER MICHIGAN AND NEAR
LAKE MICHIGAN. ALTHOUGH THE NWP SUGGESTS A FAIRLY DRY ATMOSPHERE
BEHIND THE FRONT AND BROAD SCALE SUBSIDENCE...THE 850MB FRONT
WILL STALL OUT OVER THE AREA AND INTERIOR INSTABILITY RISES TO
NEARLY 1500 J/KG. NOT TO CONFIDENT THAT ANY SHOWERS/STORMS WILL
OCCUR MONDAY AFTERNOON...BUT ALSO NOT CONFIDENT ENOUGH TO REMOVE THE
MENTION. REGARDLESS...MONDAY WILL BE COOLER AND A LITTLE LESS HUMID
THAN TODAY WITH READINGS NEAR LAKE SUPERIOR DROPPING BACK INTO THE
LOWER-MID 70S.
MONDAY NIGHT SHOULD BE A FAIRLY QUIET NIGHT ACROSS THE AREA AS THE
NEXT LOW PRESSURE SYSTEM DEVELOPS ACROSS THE PLAINS. THE MODELS HAVE
BACKED OFF ANY PCPN FOR THE AREA MONDAY NIGHT...INSTEAD FOCUSING IT
ACROSS MN WHERE THE BETTER LOW LEVEL MOISTURE TRANSPORT AND DEEP
MOISTURE WILL BE LOCATED.
SOME DISAGREEMENT REMAINS REGARDING TIMING OF PRECIPITATION ON
TUESDAY. THERE IS A HINT FROM THE ECMWF AND GFS THAT AN MCS WILL BE
ONGOING TO WEST OF THE AREA IN THE BROAD WARM ADVECTION/ISENTROPIC
LIFT AREA IN SRN MN. THIS LEADS TO MUCH UNCERTAINTY REGARDING
CONVECTIVE EVOLUTION TUE FOR THE AREA. THE MAIN FORCING MECHANISM
TUE AND TUE NIGHT WILL CONTINUE TO BE THE NRN STREAM ENERGY DIVING
OUT OF CANADA AND AMPLIFYING DURING THE DAY...AND HAVE OPTED TO
FOCUS ON THIS FEATURE SIMILAR TO THE NAM SOLUTION. WITH THE BEST
FORCING WITH ENERGY BEING LATE TUE AFTN AND EVENING...HAVE OPTED TO
MAINTAIN THE HIGHEST POPS DURING THIS PERIOD. DEPENDING ON THE
AMOUNT OF DEBRIS CLOUDS...MODEST INSTABILITY IS POSSIBLE ACROSS THE
AREA TUE AFTN/EVENING HELPING TO MAINTAIN THUNDERSTORM DEVELOPMENT
ALONG THE FRONT. CANNOT TOTALLY RULE OUT SOME ORGANIZATION TO THE
STORMS LATER TUESDAY INTO TUESDAY EVENING AS A COUPLED UPPER JET
STRUCTURE DEVELOPS ACROSS THE NRN LAKES IN RESPONSE TO THE WAVE
BECOMING NEGATIVELY TILTED.
THE FRONT MOVES THROUGH THE AREA BY WEDNEDAY MORNING. MAY BE SOME
RESIDUAL WRAP AROUND MOISTURE ACROSS THE AREA IN THE MORNING...BUT
OTHERWISE THE WEATHER SHOULD IMPROVE DURING THE DAY. MODELS IN
EXCELLENT AGREEMENT IN SHOWING BROAD HIGH PRESSURE ACROSS THE UPPER
GREAT LAKES FOR THE END OF THE WEEK WITH RISING HEIGHTS BY THE
WEEKEND. TEMPERATURES WILL BE SEASONABLE THU AND FRIDAY ALTHOUGH
ABOVE NORMAL TEMPS MAY RETURN BY SATURDAY WITH 850MB TEMPS PROGGED
TO RISE TO +16 ACROSS THE WEST. CANNOT RULE OUT SHOWERS SATURDAY
AFTERNOON AS BOTH THE GFS AND ECMWF HINT AS AN UPPER WAVE MOVING
THROUGH THE AREA IN THE WESTERLY FLOW. HOWEVER...AT THIS TIME WILL
OPT TO MAINTAIN A DRY FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 158 AM EDT SUN JUL 7 2013
LINE OF SHRA/TS NOW MOVING THRU WRN LK SUP WL IMPACT CMX/IWD EARLY
THIS MRNG...LOWERING CONDITIONS TO MVFR AT LEAST BRIEFLY AS RA
MOISTENED/LK COOLED AIR FOLLOWS INLAND. SAW SHOULD REMAIN DRY THRU
SUNRISE WITH VFR CONDITIONS. SCT SHRA/PERHAPS A TS LIMITED BY DRYING
ALF WL ARRIVE W-E ON SUN IN ADVANCE OF AN APRCHG COLD FNT. THE BEST
CHC FOR THE TS WL BE AT SAW IN THE AFTN...BUT CONFIDENCE IN TIMING
IS TOO LO TO INCLUDE IN THE TAF FOR NOW. SOME LO CLDS/MVFR CIGS ARE
LIKELY TO FOLLOW THE FROPA THIS EVNG WITH DIURNAL COOLING AND
UPSLOPE N-NW FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 505 AM EDT SUN JUL 7 2013
GIVEN EARLY SHIP OBSERVATIONS OF ZERO VISIBILITY OVER WESTERN LAKE
SUPERIOR AND VERY HUMID AIRMASS OVER CHILLY WATER FOLLOWING SOME
SHOWERS...A DENSE FOG ADVISORY WILL REMAIN IN EFFECT THIS MORNING
FOR THE WEST HALF OF LAKE SUPERIOR. SOME DRYING ON SUNDAY
AFTERNOON FOLLOWING A COLD FRONTAL PASSAGE SHOULD DISSIPATE THE
THICKEST FOG.
WINDS WILL REMAIN BELOW 15 KT ACROSS LAKE SUPERIOR THROUGH TUESDAY
AS A WEAK SURFACE TROUGH DROPS SOUTHWARD ACROSS THE LAKE FOLLOWED BY
AN AREA OF HIGH PRESSURE. WITH SHOWERS AND THUNDERSTORMS EARLY TODAY
AND ADDITIONAL SCT SHRA/TSRA POSSIBLE THIS AFTERNOON...AREAS
OF FOG WILL CONTINUE ACROSS THE LAKE. AS ANOTHER LOW DEVELOPS OVER
THE PLAINS ON TUESDAY AND APPROACHES LAKE SUPERIOR ON
WEDNESDAY....NORTHWESTERLY WINDS OF 15 TO 25 KNOTS WILL BE POSSIBLE
BEHIND FOR A TIME WEDNESDAY AND WEDNESDAY NIGHT. A SURFACE HIGH
MOVING OVER THE UPPER LAKES LATE IN THE WEEK WILL ALLOW LIGHT WINDS
TO RETURN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 2 PM EDT /1 PM CDT/ THIS AFTERNOON FOR
LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
643 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM CDT MON JUL 8 2013
TONIGHT/S AND TUESDAY/S WX IS DEPENDENT ON THE EVOLUTION OF THE
MCS/S OR DECAYING MCS/S ACROSS SD AND MT. INITIALLY...WEAK HIGH
PRESSURE AND EARLIER STABLE CONDS BLW 3K...ALLOWED FOR STRATUS TO
FORM OVERNIGHT...WHICH PERSISTENT THRU THE EARLY AFTN AS CLOSE AS
WC WI. THE WEAKER WIND FIELD ACROSS WC WI WILL LIKELY ENHANCE THE
FORMATION OF FOG/BR OVERNIGHT IN THE TYPICAL AREAS...AND MAY BE
LOCALLY DENSE IF SKIES REMAIN CLR. AS FOR MN...SFC WINDS HAVE
SHIFTED SLIGHTLY TO THE E/SE IN RESPONSE TO THE ANOTHER SHRTWV
ACROSS THE SD. MAIN SFC BOUNDARY HAS STALLED IN CENTRAL IA THIS
AFTN...WITH A FAIRLY POTENT SHRTWV NEAR OMA. THIS WILL ENHANCE
LARGE SCALE LIFT AND CONVECTION ACROSS CENTRAL IA THIS AFTN. BASED
ON THE E/SE FLOW DEVELOPING ACROSS SW MN...AS WELL AS ANOTHER
DISTURBANCE MOVING ACROSS CENTRAL SD...ANOTHER AREA OF CONVECTION
WILL LIKELY FORM IN CENTRAL/SE SD...AND MOVE ESE ACROSS FAR SW MN.
HOW FAR NORTH THIS ACTIVITY MOVES IS DEPENDENT ON THE RETREAT OF
THE STABLE CONDS IN PORTIONS OF CENTRAL/EC MN OVERNIGHT. BY
TUESDAY MORNING...THE ATMOSPHERE ACROSS MN SHOULD HAVE
DESTABILIZED ENOUGH FOR SHRA/TSRA ACROSS THE REGION. HOWEVER...LOW
CONFIDENCE ON HOW WIDESPREAD THIS ACTIVITY WILL BE DUE TO INITIAL
DRY ATMOSPHERE ABV 5K. OVERALL...SHRA/TSRA ACTIVITY SHOULD
INCREASE TUESDAY...AND ESPECIALLY TUESDAY AFTN AS THE NEXT FRONTAL
BOUNDARY HOLDS OFF ACROSS NW MN THRU THE EARLY AFTN. IN TERMS OF
SVR WX...THE BEST SCENARIO WOULD BE SC/SE MN/WC WI TUESDAY AFTN AS
THE FRONTAL BOUNDARY WILL BE NORTHWEST OF THIS REGION. OVERNIGHT
CHC/S REMAIN UNCERTAIN DUE TO THE INITIAL STABLE CONDS AND THE
FRONT STILL ACROSS IA DURING THE TYPICAL AFTN/EVENING HRS TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 PM CDT MON JUL 8 2013
DISTINCT NNE-SSW H5 TROF AXIS PUSHING THRU THE DAKOTAS WILL HELP
PUSH A CDFNT THRU MN AND WI OVERNIGHT TUE INTO WED MRNG. CONVECTION
WILL LIKELY BE ONGOING AT THE START OF THE PERIOD...EITHER IN
CLUSTERS OF TSTMS OR POSSIBLY AS A STRONG-SEVERE MCS. CONTINUED HIGH
INSTABILITY DUE TO A DEEP MOISTURE PROFILE ALONG WITH STRONG LOW-
AND MID-LVL JETTING AND STEEP LAPSE RATES WILL CONTRIBUTE TO THE
STRONG TSTM DEVELOPMENT. THE STORMS WILL EXIT THE MPX CWFA BY
DAYBREAK WED MRNG. THE TROF AXIS WILL ALSO BE OVER THE GREAT LAKES
BY WED MRNG...ALLOWING PRONOUNCED NW FLOW UNDERNEATH INCOMING HIGH
PRES TO PREVAIL FOR WED AND THU. THE LOWER HEIGHTS AND NW FLOW WILL
ALLOW FOR COOLER/DRIER CONDITIONS BOTH DAYS. HOWEVER...THE COOLDOWN
WILL BE BRIEF AS MUCH HIGHER H5 HEIGHTS IN A BUILDING RIDGE MOVE
ACRS THE AREA ON FRI...WHICH WILL LIKELY BRING A RETURN OF HIGHS IN
THE MID-UPR 80S FOR MUCH OF THE AREA. ANOTHER FRONTAL SYSTEM WILL
CROSS THE REGION OVER THE WEEKEND...WITH GREATEST CHC OF PRECIP FRI
NIGHT INTO SAT MRNG. STILL TOO EARLY TO DETERMINE STORM STRENGTH BUT
GIVEN THE RETURN OF HIGHER DEWPOINTS/INSTABILITY...ENHANCED JETTING
AND ANOTHER CDFNT...STRONG STORMS CERTAINLY CANNOT BE RULED OUT.
ANOTHER TRANQUIL PERIOD LOOKS TO COME OVER THE WEEKEND WITH WEAK
HIGH PRES COMING ACROSS...BUT ISOLD SHWRS/TSTMS CANNOT BE RULED OUT
HERE. HIGHS DROP TO THE UPR 70S/LWR 80S WED-THU THEN JUMP BACK INTO
THE MID-UPR 80S FRI-SUN WITH DEWPOINTS RISING AS WELL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 602 PM CDT MON JUL 8 2013
SEVERAL CONCERNS FOR THE PERIOD AHEAD. THE FIRST IS CONVECTION
DEVELOPING ALONG AND NORTH OF A STATIONARY FRONT NEAR THE NE/SD
BORDER. HRRR PROJECTIONS OVER THE LAST SEVERAL RUNS REMAIN
CONSISTENT ON BRINGING THE SHRA/TSRA INTO WEST CENTRAL AND
SOUTHWEST MN BY 07Z. THIS ACTIVITY WOULD THEN REACH THE TWIN
CITIES IN THE 10Z-12Z TIME FRAME. THE 18Z HOPWRF IS A LITTLE
DIFFERENT WITH SCT SHRA/TSRA ACTUALLY DEVELOPING FROM KSTC TO KMSP
BETWEEN 10Z AND 12Z. HENCE...THERE REMAINS UNCERTAINTY ON HOW THE
CONVECTION UNFOLDS BUT THERE IS CERTAINLY A CHANCE DURING THE LATE
EVENING AND OVERNIGHT HOURS AT THE MN TAF SITES. THE TENDENCY
WOULD THEN BE FOR THE SHRA/TSRA TO WORK ACROSS KRNH AND KEAU
DURING THE MORNING WHILE MORE ACTIVITY DEVELOPS BACK TO THE WEST
ALONG AN APPROACHING COLD FRONT. SREF PROBABILITIES FOR
MEASURABLE PRECIP TUE AFTERNOON ALONG AND AHEAD OF THE FRONT ARE
VERY HIGH. VERY UNSTABLE CONDITIONS EXIST AND PROB30 GROUPS WERE
INSERTED AT THE TAF SITES. INCREASING NW WINDS TUESDAY EVENING
WITH THE ACTIVITY ENDING FROM WEST TO EAST. THE OTHER CONCERN
TONIGHT IS THE POTENTIAL FOR BR/FG/STRATUS FROM KSTC THROUGH KRNH AND
KEAU. BUFKIT FOG TECHNIQUE SHOWS THE HYDROLAPSE INCREASING WITH
HEIGHT BUT THE AMOUNT OF MID/HIGH LEVEL CLOUDS ARRIVING OVERNIGHT
MAY DAMPEN THE THREAT OF IFR OR LOWER BR/FG. THE HOPWRF
PROBABILITIES ARE HIGHEST (30-40 PERCENT) FOR 3 MILES OR LOWER AT
KSTC AND KEAU WITH KEAU HAVING ABOUT THE SAME PROBABILITY FOR LESS
THAN 1 MILE. THEREFORE...LIMITED RESTRICTIONS TO THESE TWO SITES.
KMSP...INCREASING MID/HIGH LEVEL CLOUDS THIS EVENING WITH THE
THREAT FOR SHRA/TSRA BETWEEN 10Z AND 14Z. MVFR OR LOWER CONDITIONS
IN THE SHRA/TSRA. SOME STRATUS UNDER 010 POSSIBLE DURING THE EARLY
MORNING HOURS AS WELL BUT CONFIDENCE IS NOT HIGH ON WHETHER IT
BECOMES A BKN-OVC DECK LIKE THIS PAST MORNING. MORE THUNDERSTORMS
TUESDAY AFTERNOON AS A COLD FRONT MOVES IN. THE FRONT LIKELY
REACHING THE AIRFIELD BETWEEN 10/01Z-02Z. PROB GROUP INSERTED FOR
THUNDERSTORM CHANCES AHEAD OF THE FRONT. NW WINDS DEVELOPING IN
THE WAKE OF THE FRONT TUESDAY EVENING ALONG WITH SHRA ENDING.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW 10G20KTS.
THU...VFR. WINDS LGT AND VRB.
FRI...VFR. WINDS S 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...JPC
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1158 AM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT SUN JUL 7 2013
A COUPLE OF WEAK BOUNDARIES OF CONCERN TO START THE DAY. ONE IS A
TROUGH/COLD FRONT THAT AT 3 AM WAS ALONG THE ND/MN DOWN TO A WEAK
LOW OVER NE SODAK...EXTENDING BACK SW INTO CENTRAL NEB. OTHER
BOUNDARY IS A STATIONARY FRONT EXTENDING FROM AROUND MORRIS ACROSS
CENTRAL MN INTO THE HAYWARD AREA. LLJ AND WAA REGIME NORTH OF THE
STATIONARY BOUNDARY HAS GENERATED A CLUSTER OF STORMS OVER LAKE
SUPERIOR THAT HAVE STAYED SAFELY AWAY FROM THE MPX AREA OVERNIGHT.
FOR TODAY...THIS STATIONARY BOUNDARY WILL START TO LOOSE ITS
DEFINITION AS IT SLOWLY SAGS SE. MOST DETERMINISTIC MODELS SAY TODAY
WILL BE DRY AS GRADUAL HEIGHT RISES OVERTAKE THE AREA.
HOWEVER...THE ZONAL FLOW OVER THE REGION TODAY LOOKS TO BE OF THE
DIRTY VARIETY...WITH THE RAP/GFS/NAM SHOWING SMALL PERTURBATIONS
CURRENTLY GENERATING STORMS OUT OVER MT/WY WORKING ACROSS MN DURING
THE LATE AFTERNOON/EARLY EVENING. 07.00 NAM SOUNDINGS SHOW A RATHER
UNSTABLE ENVIRONMENT BEING IN PLACE AS THESE WAVES APPROACH...WITH
2000-3000+ J/KG OF UNCAPPED SBCAPE BEING IN PLACE. AT THE SAME
TIME...RAP SOUNDINGS ONLY ABLE TO GENERATE 1500 J/KG AT BEST.
700-500 MB LAPSE RATES ARE MEAGER ON BOTH /ABOUT 6 DEG C PER
KM/...WITH THE DIFFERENCE COMING WITH HANDLING OF LOW LEVEL
MOISTURE...AS THE RAP LOOKS A LITTLE AGGRESSIVE ON MIXING OUT DEWPS
THIS AFTERNOON...WHICH IN TURN IS IMPACTING ITS INSTABILITY
FORECAST. NAM IDEA IS PROBABLY MORE REALISTIC...BUT GIVEN MID-LEVEL
LAPSE RATES...WOULD FAVOR 1500-2500 J/KG OF CAPE TO WORK WITH TODAY.
WITH ALL THAT SAID...AT THE MOMENT ONLY HAVE CHANCE POPS MENTIONED
IN THE FAR ERN CWA THIS AFTERNOON AS THIS IS WHERE SOME FORM OF LLJ
FORCING LOOKS TO RESIDE...BUT GIVEN THE INSTABILITY MENTIONED
ABOVE...COULD SEE STORMS DEVELOP ANYWHERE ALONG/SOUTH OF THE
STATIONARY BOUNDARY. 03Z HOPWRF ENSEMBLE REFLECTIVITY FORECASTS HINT
AT THIS HAPPENING...WITH SCATTERED CONVECTION SEEN AT 21Z ON MEMBERS
1/3/4 ACROSS MOST OF THE AREA. GUESS AT THIS POINT...THIS "WET
PATTERN" THAT SET IN FRIDAY NIGHT HAS NOT EXACTLY PRODUCED MUCH IN
THE WAY OF OBSERVABLE PRECIPITATION IN THE MPX AREA...SO AM A BIT
GUN SHY ON GOING TO HIGH WITH POPS AT THIS POINT. WITH LOW LEVEL
FLOW BACKING OFF CONSIDERABLY TODAY...LOW LEVEL SHEAR WILL BE PRETTY
WEAK TODAY...BUT WITH INVERTED V SOUNDINGS SEEN IN MODELS...A
CONDITIONAL WIND THREAT WOULD EXIST.
FOR TONIGHT...LLJ FORCING AND THICKNESS PATTERN CONTINUE TO SHOW THE
MPX AREA SPLIT BETWEEN BETTER REGIONS OF FORCING FOR CONVECTION OVER
NRN IL/SRN WI AND OUT WEST ACROSS THE DAKOTAS...SO EXPECT TONIGHT TO
BE DRY ONCE ANY DIURNALLY DRIVEN ACTIVITY DISSIPATES THIS EVENING.
FOR TEMPERATURES...DENSE MID LEVEL CLOUD COVER SHOULD CLEAR ERN
AREAS FAIRLY QUICKLY THIS MORNING...WITH A FAIR AMOUNT OF SUNSHINE
EXPECTED AS A RESULT. AIR-MASS HAS CHANGED VERY LITTLE SINCE
YESTERDAY...SO EXPECT HIGHS TO BE VERY SIMILAR TO WHAT WAS SEEN
OUTSIDE OF CENTRAL MINNESOTA ON SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 409 AM CDT SUN JUL 7 2013
MAIN CHALLENGE IS TRYING TO PINPOINT THE TIMING AND PLACEMENT OF
POPS EARLY IN THE WEEK BEFORE WE DRY OUT WEDNESDAY THROUGH FRIDAY.
THE UPPER LEVEL RIDGE ANCHORED OVER THE DESERT SOUTHWEST WILL
REMAIN THROUGHOUT THE PERIOD. MONDAY SHOULD START OUT DRY AS THE
LOW LEVEL JET AS SEEN IN THE H925 WINDS AND MOISTURE TRANSPORT
WILL REMAIN WELL SOUTH OF THE FORECAST AREA IN SOUTHERN
IOWA/ILLINOIS. THE HUMID AIR-MASS WILL PERSIST ACROSS THE UPPER
MIDWEST...AND WITH LITTLE MIXING EXPECTED ON MONDAY HAVE INCREASED
DEW-POINTS INTO THE LOW 70S. BY MONDAY EVENING FORECAST MODELS
INDICATE A SUBTLE H500 SHORTWAVE ROTATING AROUND THE PERIPHERY OF
THE AFOREMENTIONED MONSOON RIDGE AND THIS SHOULD TRIGGER OFF SOME
DEEP CONVECTION ON THE LEE SIDE OF THE ROCKIES WHICH WILL ADVECT
EASTWARD OVER THE HIGH PLAINS OF THE DAKOTAS...AND COULD REACH THE
CWA LATER MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE 07.12 GFS
AND ECMWF PLACE THE NOSE OF THE LOW LEVEL JET IN A FAVORABLE
LOCATION FOR CONVECTION OVER THE MISSISSIPPI RIVER VALLEY.
CURRENTLY HAVE THE HIGHEST POPS ALONG I90 NEAR THE IA BORDER...BUT
THESE MAY NEED TO BE ADJUSTED NORTHWARD IF THE MODELS FOLLOW THE
LEAD OF THE ECMWF...WHICH TAKES THE MCS ALONG AND NORTH OF I94.
THERE WILL BE PLENTY OF INSTABILITY AS SREF PLUMES KEEP AROUND
1000 J/KG OF MUCAPE ACROSS THE REGION MONDAY NIGHT...WITH ROUGHLY
30KTS OF DEEP LAYER SHEAR DEPENDING ON THE PLACEMENT OF THE LLJ.
THE FORECAST FOR TUESDAY BECOMES DIFFICULT SINCE MANY OF THE DETAILS
HINGES DIRECTLY ON THE MESOSCALE FEATURES LEFT IN THE WAKE OF THE
EARLY MORNING CONVECTION. A MORE WELL-DEFINED SHORTWAVE CURRENTLY
OFF THE MOVING DOWN THE COAST OF BRITISH COLUMBIA WILL TRANSLATE
EASTWARD IN THE ZONAL FLOW ALONG THE INTERNATIONAL BORDER AND ARRIVE
ACROSS THE UPPER MIDWEST TUESDAY AFTERNOON. THIS WILL DRIVE A COLD
FRONT THROUGH THE REGION ON TUESDAY...HOWEVER EXPECT ANY REMNANT
DEBRIS CLOUDS TO CLEAR OFF ALLOWING THE BOUNDARY LAYER TO RECOVER
DURING THE LATE MORNING HOURS...WITH AN UNSTABLE ENVIRONMENT SETTING
UP ACROSS THE MN/WI BORDER BY TUESDAY AFTERNOON. AN H500 SPEED MAX
OF 60KTS...ALONG WITH 3M/HR HEIGHT FALLS WILL PROVIDE SYNOPTIC SCALE
FORCING FOR SEVERE THUNDERSTORMS AHEAD OF THE COLD FRONT. AS ALLUDED
TO IN THE SPC DAY3 OUTLOOK...ANY OUTFLOW BOUNDARY PRODUCED BY THE
EARLY MORNING CONVECTION WILL BE THE FOCUS FOR AN ENHANCED THREAT OF
SEVERE WEATHER...INCLUDING TORNADOES AS THE SURFACE WINDS BACK AHEAD
OF THE COLD FRONT. NAM BUFR SOUNDINGS FOR TUESDAY AFTERNOON AT KRWF
SHOW A CYCLONICALLY CURVED HODOGRAPH WITH 0-3KM HELICITY OF OVER
300M2/S2. THE GFS IS FASTER WITH THE COLD FRONT...SO ITS LINEAR
SHEAR PROFILE WITH NORTHWEST WIND IS LESS FAVORABLE FOR
TORNADOES...BUT RATHER WOULD SUPPORT STRAIGHT LINE WINDS.
REGARDLESS...TUESDAY SEVERE THREAT LOOKS TO BE THE MAIN CONCERN
DURING THE EXTENDED.
NORTHWEST FLOW IN THE WAKE OF THIS COLD FRONT WILL USHER IN DRIER
AIR AS A CANADIAN HIGH PRESSURE BUILDS ON WEDNESDAY AND KEEPS THE
REGION DRY THROUGH FRIDAY. HAVE INCREASED WINDS SLIGHTLY ABOVE
GUIDANCE ON WEDNESDAY AS FORECAST SOUNDINGS SHOW ANOTHER GOOD MIXING
DAY. LOOKING AHEAD...THE REPRIEVE FROM THE HEAT AND HUMIDITY WILL BE
SHORT-LIVED AS THE THERMAL RIDGE DEVELOPS BY THE END OF THE WORK WEEK
ACROSS THE HIGH PLAINS. WILL ACTUALLY SEE A WEST/EAST TEMPERATURE
GRADIENT BY THE WEEKEND...WITH MUCH WARMER TEMPERATURES ACROSS
WESTERN MINNESOTA. CURRENTLY HAVE MORE OF A BLENDED APPROACH WHICH
YIELDS ONLY MID 80S ACROSS THE WEST. THERE IS STILL
UNCERTAINTY...BUT IF THE H850 TEMPS REMAIN 20-22C WILL LIKELY SEE
HIGHS IN THE MID 90S NEAR THE MN/SD BORDER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1140 AM CDT SUN JUL 7 2013
AS TYPICAL IN THE SUMMER...CONVECTION BEGINS TO DECREASE BY THE
LATE MORNING AS LCL/S LIFT AND THE CAP STRENGTHENS. HOWEVER...IF
ANY THUNDERSTORM COMPLEX CONTINUES THRU THE MID/LATE MORNING HRS
AS IS THE COMPLEX IN NORTHERN SD...THE CHC/S OF IT CONTINUING THRU
THE AFTN IS HIGH. THE ONLY PROBLEM IS A SFC BOUNDARY HAS MOVED
INTO WESTERN MN TODAY. BUT...AT THE SAME TIME SFC MOISTURE HAS
POOLED WHICH HAS ALLOWED FOR MLCAPES TO INCREASE. OVER THE PAST
FEW HRS...THIS SFC BOUNDARY HAS NEARLY STALLED. THIS FRONT AND THE
LEFTOVER CONVECTION ACROSS WC WI WILL LIKELY BE THE FOCUS FOR MORE
SHRA/TSRA DEVELOPMENT THIS AFTN. THE ONLY PROBLEM NEAR MSP AND
SOUTHWARD TO THE MN/IA BORDER...IS THE INCREASING CIN NOTED. THIS
MAY HINDER ANY DEVELOPMENT IN THIS AREA...BUT WITH THE COMPLEX
ACROSS SD MOVING EASTWARD THIS AFTN...IT WILL LIKELY MODIFIED THE
ATMOSPHERE AND CAUSE MORE SHRA/TSRA THAN CURRENT MODELS INDICATE.
BECAUSE OF THIS SCENARIO...WILL ADD VCSH TO ALL BUT AXN WHICH IS
DEEPER IN THE N/NE FLOW AND K-INDEX VALUES ARE VERY LOW ATTM. RWF
WILL LIKELY SEE VCSH BY 20-22Z...BUT TSRA CHC/S ARE TOO VARIABLE
SO NOT ADDING VCTS ATTM. MSP/STC/RNH/EAU ALL HAVE LOW CHC/S OF
SEEING CONVECTION THIS AFTN. HOW WIDESPREAD THE ACTIVITY
GETS...REMAINS UNCERTAIN. WINDS WILL BE GENERALLY LIGHT AND
VARIABLE WITH A MORE N/NE DIRECTION AT STC/AXN...AND MORE S/SW AT
RNH/EAU/MSP/RWF. FOG/BR POTENTIAL IS ALSO GOOD OVERNIGHT WITH THE
BOUNDARY NEAR THE AREA...AND LITTLE BOUNDARY LAYER MIXING.
KMSP...
THE FORECAST IS HIGHLY DEPENDENT ON HOW MUCH MIXING IN THE LOW
LEVELS DEVELOP THIS AFTN AND WHETHER ENOUGH CIN TO LOWER CHC/S OF
SHRA/TSRA. BASED ON THE LATEST REGIONAL RADAR/SFC BOUNDARY OUT
WEST...AND THE CONTINUED TREND OF HIGH K-INDEX/S...WILL CONTINUE
WITH VCSH...WITH THE BEST POTENTIAL OF SHRA/TSRA BETWEEN 23-02Z.
AFT 2Z...THE PROBABILITY IS LOWER FOR SHRA/TSRA CHC/S...BUT WILL
NEED TO WATCH WHAT HAPPENS WITH THE COMPLEX IN SD LATER THIS AFTN.
WINDS WILL BE GENERALLY LIGHT SW THIS AFTN...LIGHT AND VARIABLE
TONIGHT...WITH A LIGHT NE WIND MONDAY.
/OUTLOOK FOR KMSP/
MONDAY NIGHT. CHC TSRA LATE NIGHT. WINDS E 5 KTS.
TUE...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SE BCMG NW AT 5 KTS.
WED...VFR. WINDS NW 10G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
634 AM CDT SUN JUL 7 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT SUN JUL 7 2013
A COUPLE OF WEAK BOUNDARIES OF CONCERN TO START THE DAY. ONE IS A
TROUGH/COLD FRONT THAT AT 3 AM WAS ALONG THE ND/MN DOWN TO A WEAK
LOW OVER NE SODAK...EXTENDING BACK SW INTO CENTRAL NEB. OTHER
BOUNDARY IS A STATIONARY FRONT EXTENDING FROM AROUND MORRIS ACROSS
CENTRAL MN INTO THE HAYWARD AREA. LLJ AND WAA REGIME NORTH OF THE
STATIONARY BOUNDARY HAS GENERATED A CLUSTER OF STORMS OVER LAKE
SUPERIOR THAT HAVE STAYED SAFELY AWAY FROM THE MPX AREA OVERNIGHT.
FOR TODAY...THIS STATIONARY BOUNDARY WILL START TO LOOSE ITS
DEFINITION AS IT SLOWLY SAGS SE. MOST DETERMINISTIC MODELS SAY TODAY
WILL BE DRY AS GRADUAL HEIGHT RISES OVERTAKE THE AREA.
HOWEVER...THE ZONAL FLOW OVER THE REGION TODAY LOOKS TO BE OF THE
DIRTY VARIETY...WITH THE RAP/GFS/NAM SHOWING SMALL PERTURBATIONS
CURRENTLY GENERATING STORMS OUT OVER MT/WY WORKING ACROSS MN DURING
THE LATE AFTERNOON/EARLY EVENING. 07.00 NAM SOUNDINGS SHOW A RATHER
UNSTABLE ENVIRONMENT BEING IN PLACE AS THESE WAVES APPROACH...WITH
2000-3000+ J/KG OF UNCAPPED SBCAPE BEING IN PLACE. AT THE SAME
TIME...RAP SOUNDINGS ONLY ABLE TO GENERATE 1500 J/KG AT BEST.
700-500 MB LAPSE RATES ARE MEAGER ON BOTH /ABOUT 6 DEG C PER
KM/...WITH THE DIFFERENCE COMING WITH HANDLING OF LOW LEVEL
MOISTURE...AS THE RAP LOOKS A LITTLE AGGRESSIVE ON MIXING OUT DEWPS
THIS AFTERNOON...WHICH IN TURN IS IMPACTING ITS INSTABILITY
FORECAST. NAM IDEA IS PROBABLY MORE REALISTIC...BUT GIVEN MID-LEVEL
LAPSE RATES...WOULD FAVOR 1500-2500 J/KG OF CAPE TO WORK WITH TODAY.
WITH ALL THAT SAID...AT THE MOMENT ONLY HAVE CHANCE POPS MENTIONED
IN THE FAR ERN CWA THIS AFTERNOON AS THIS IS WHERE SOME FORM OF LLJ
FORCING LOOKS TO RESIDE...BUT GIVEN THE INSTABILITY MENTIONED
ABOVE...COULD SEE STORMS DEVELOP ANYWHERE ALONG/SOUTH OF THE
STATIONARY BOUNDARY. 03Z HOPWRF ENSEMBLE REFLECTIVITY FORECASTS HINT
AT THIS HAPPENING...WITH SCATTERED CONVECTION SEEN AT 21Z ON MEMBERS
1/3/4 ACROSS MOST OF THE AREA. GUESS AT THIS POINT...THIS "WET
PATTERN" THAT SET IN FRIDAY NIGHT HAS NOT EXACTLY PRODUCED MUCH IN
THE WAY OF OBSERVABLE PRECIPITATION IN THE MPX AREA...SO AM A BIT
GUN SHY ON GOING TO HIGH WITH POPS AT THIS POINT. WITH LOW LEVEL
FLOW BACKING OFF CONSIDERABLY TODAY...LOW LEVEL SHEAR WILL BE PRETTY
WEAK TODAY...BUT WITH INVERTED V SOUNDINGS SEEN IN MODELS...A
CONDITIONAL WIND THREAT WOULD EXIST.
FOR TONIGHT...LLJ FORCING AND THICKNESS PATTERN CONTINUE TO SHOW THE
MPX AREA SPLIT BETWEEN BETTER REGIONS OF FORCING FOR CONVECTION OVER
NRN IL/SRN WI AND OUT WEST ACROSS THE DAKOTAS...SO EXPECT TONIGHT TO
BE DRY ONCE ANY DIURNALLY DRIVEN ACTIVITY DISSIPATES THIS EVENING.
FOR TEMPERATURES...DENSE MID LEVEL CLOUD COVER SHOULD CLEAR ERN
AREAS FAIRLY QUICKLY THIS MORNING...WITH A FAIR AMOUNT OF SUNSHINE
EXPECTED AS A RESULT. AIRMASS HAS CHANGED VERY LITTLE SINCE
YESTERDAY...SO EXPECT HIGHS TO BE VERY SIMILAR TO WHAT WAS SEEN
OUTSIDE OF CENTRAL MINNESOTA ON SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 409 AM CDT SUN JUL 7 2013
MAIN CHALLENGE IS TRYING TO PINPOINT THE TIMING AND PLACEMENT OF
POPS EARLY IN THE WEEK BEFORE WE DRY OUT WEDNESDAY THROUGH FRIDAY.
THE UPPER LEVEL RIDGE ANCHORED OVER THE DESERT SOUTHWEST WILL
REMAIN THROUGHOUT THE PERIOD. MONDAY SHOULD START OUT DRY AS THE
LOW LEVEL JET AS SEEN IN THE H925 WINDS AND MOISTURE TRANSPORT
WILL REMAIN WELL SOUTH OF THE FORECAST AREA IN SOUTHERN
IOWA/ILLINOIS. THE HUMID AIRMASS WILL PERSIST ACROSS THE UPPER
MIDWEST...AND WITH LITTLE MIXING EXPECTED ON MONDAY HAVE INCREASED
DEWPOINTS INTO THE LOW 70S. BY MONDAY EVENING FORECAST MODELS
INDICATE A SUBTLE H500 SHORTWAVE ROTATING AROUND THE PERIPHERY OF
THE AFOREMENTIONED MONSOON RIDGE AND THIS SHOULD TRIGGER OFF SOME
DEEP CONVECTION ON THE LEE SIDE OF THE ROCKIES WHICH WILL ADVECT
EASTWARD OVER THE HIGH PLAINS OF THE DAKOTAS...AND COULD REACH THE
CWA LATER MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE 07.12 GFS
AND ECMWF PLACE THE NOSE OF THE LOW LEVEL JET IN A FAVORABLE
LOCATION FOR CONVECTION OVER THE MISSISSIPPI RIVER VALLEY.
CURRENTLY HAVE THE HIGHEST POPS ALONG I90 NEAR THE IA BORDER...BUT
THESE MAY NEED TO BE ADJUSTED NORTHWARD IF THE MODELS FOLLOW THE
LEAD OF THE ECMWF...WHICH TAKES THE MCS ALONG AND NORTH OF I94.
THERE WILL BE PLENTY OF INSTABILITY AS SREF PLUMES KEEP AROUND
1000 J/KG OF MUCAPE ACROSS THE REGION MONDAY NIGHT...WITH ROUGHLY
30KTS OF DEEP LAYER SHEAR DEPENDING ON THE PLACEMENT OF THE LLJ.
THE FORECAST FOR TUESDAY BECOMES DIFFICULT SINCE MANY OF THE DETAILS
HINGES DIRECTLY ON THE MESOSCALE FEATURES LEFT IN THE WAKE OF THE
EARLY MORNING CONVECTION. A MORE WELL-DEFINED SHORTWAVE CURRENTLY
OFF THE MOVING DOWN THE COAST OF BRITISH COLUMBIA WILL TRANSLATE
EASTWARD IN THE ZONAL FLOW ALONG THE INTERNATIONAL BORDER AND ARRIVE
ACROSS THE UPPER MIDWEST TUESDAY AFTERNOON. THIS WILL DRIVE A COLD
FRONT THROUGH THE REGION ON TUESDAY...HOWEVER EXPECT ANY REMNANT
DEBRIS CLOUDS TO CLEAR OFF ALLOWING THE BOUNDARY LAYER TO RECOVER
DURING THE LATE MORNING HOURS...WITH AN UNSTABLE ENVIRONMENT SETTING
UP ACROSS THE MN/WI BORDER BY TUESDAY AFTERNOON. AN H500 SPEED MAX
OF 60KTS...ALONG WITH 3M/HR HEIGHT FALLS WILL PROVIDE SYNOPTIC SCALE
FORCING FOR SEVERE THUNDERSTORMS AHEAD OF THE COLD FRONT. AS ALLUDED
TO IN THE SPC DAY3 OUTLOOK...ANY OUTFLOW BOUNDARY PRODUCED BY THE
EARLY MORNING CONVECTION WILL BE THE FOCUS FOR AN ENHANCED THREAT OF
SEVERE WEATHER...INCLUDING TORNADOES AS THE SURFACE WINDS BACK AHEAD
OF THE COLD FRONT. NAM BUFR SOUNDINGS FOR TUESDAY AFTERNOON AT KRWF
SHOW A CYCLONICALLY CURVED HODOGRAPH WITH 0-3KM HELICITY OF OVER
300M2/S2. THE GFS IS FASTER WITH THE COLD FRONT...SO ITS LINEAR
SHEAR PROFILE WITH NORTHWEST WIND IS LESS FAVORABLE FOR
TORNADOES...BUT RATHER WOULD SUPPORT STRAIGHT LINE WINDS.
REGARDLESS...TUESDAY SEVERE THREAT LOOKS TO BE THE MAIN CONCERN
DURING THE EXTENDED.
NORTHWEST FLOW IN THE WAKE OF THIS COLD FRONT WILL USHER IN DRIER
AIR AS A CANADIAN HIGH PRESSURE BUILDS ON WEDNESDAY AND KEEPS THE
REGION DRY THROUGH FRIDAY. HAVE INCREASED WINDS SLIGHTLY ABOVE
GUIDANCE ON WEDNESDAY AS FORECAST SOUNDINGS SHOW ANOTHER GOOD MIXING
DAY. LOOKING AHEAD...THE REPRIEVE FROM THE HEAT AND HUMIDITY WILL BE
SHORTLIVED AS THE THERMAL RIDGE DEVELOPS BY THE END OF THE WORK WEEK
ACROSS THE HIGH PLAINS. WILL ACTUALLY SEE A WEST/EAST TEMPERATURE
GRADIENT BY THE WEEKEND...WITH MUCH WARMER TEMPERATURES ACROSS
WESTERN MINNESOTA. CURRENTLY HAVE MORE OF A BLENDED APPROACH WHICH
YIELDS ONLY MID 80S ACROSS THE WEST. THERE IS STILL
UNCERTAINTY...BUT IF THE H850 TEMPS REMAIN 20-22C WILL LIKELY SEE
HIGHS IN THE MID 90S NEAR THE MN/SD BORDER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 633 AM CDT SUN JUL 7 2013
AFTER ALMOST THE ENTIRE NIGHT...SHOWERS HAVE FINALLY STARTED
BUILDING DOWN THE LLJ INTO WRN WI. THEY WILL BE FAST MOVING THOUGH
AND OUT OF THE EAU AREA BY 14Z. AFTER THAT...WILL BE WAITING UNTIL
ABOUT 22Z FOR WHEN NEXT CHANCE FOR TSRA DEVELOPS. CERTAINLY THE
NAM WOULD CONTINUE TO LEAVE ONE TO BELIEVE AN AREA OF SCT STORMS
COULD DEVELOP IN THE STC/MSP AREA THIS AFTERNOON...BUT CONFIDENCE
NOT VERY HIGH IN THIS OCCURRING AT THE MOMENT AS MODELS HAVE BEEN
A LITTLE OVER EXUBERANT IN GENERATING CONVECTION THE LAST COUPLE OF
DAYS. TONIGHT WILL SEE SIMILAR CONDITIONS TO WHAT WAS SEEN LAST
NIGHT OVER CENTRAL MN: CALM WINDS...MAINLY CLEAR SKIES...AND DEWPS
UP AROUND 70. AS A RESULT...LAMP IS PRETTY AGGRESSIVE WITH
KNOCKING VIS DOWN LATE SUNDAY NIGHT. HOWEVER...THIS MORNING WHERE
DENSE FOG FORMED...HIGHS YESTERDAY WERE ONLY IN THE 70S...EXPECT
UPPER 80S TO LOWER 90S EVERYWHERE TODAY...WHICH SHOULD LIMIT THE
FG POTENTIAL TONIGHT TO MVFR...IFR AT WORSE.
KMSP...OUTSIDE OF A SMALL CHANCE FOR TSRA BETWEEN ABOUT 22Z AND
02Z...THIS TAF PERIOD LOOKS DRY WITH VERY LIGHT WINDS. WITH CLEAR
SKIES AND HIGH DEWP AIR IN PLACE...SHOULD START OF MONDAY MORNING
QUITE HAZY...WITH POSSIBLY SOME FOG DOWN IN THE RIVER VALLEY...BUT
THAT SHOULD BE IT FOR POTENTIAL RESTRICTIONS.
/OUTLOOK FOR KMSP/
MON...MVFR VIS POSSIBLE EARLY. CHC TSRA LATE NIGHT. WINDS E 5 KTS.
TUE...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SE BCMG NW AT 5 KTS.
WED...VFR. WINDS NW 10G20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
416 AM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CDT SUN JUL 7 2013
A COUPLE OF WEAK BOUNDARIES OF CONCERN TO START THE DAY. ONE IS A
TROUGH/COLD FRONT THAT AT 3 AM WAS ALONG THE ND/MN DOWN TO A WEAK
LOW OVER NE SODAK...EXTENDING BACK SW INTO CENTRAL NEB. OTHER
BOUNDARY IS A STATIONARY FRONT EXTENDING FROM AROUND MORRIS ACROSS
CENTRAL MN INTO THE HAYWARD AREA. LLJ AND WAA REGIME NORTH OF THE
STATIONARY BOUNDARY HAS GENERATED A CLUSTER OF STORMS OVER LAKE
SUPERIOR THAT HAVE STAYED SAFELY AWAY FROM THE MPX AREA OVERNIGHT.
FOR TODAY...THIS STATIONARY BOUNDARY WILL START TO LOOSE ITS
DEFINITION AS IT SLOWLY SAGS SE. MOST DETERMINISTIC MODELS SAY TODAY
WILL BE DRY AS GRADUAL HEIGHT RISES OVERTAKE THE AREA.
HOWEVER...THE ZONAL FLOW OVER THE REGION TODAY LOOKS TO BE OF THE
DIRTY VARIETY...WITH THE RAP/GFS/NAM SHOWING SMALL PERTURBATIONS
CURRENTLY GENERATING STORMS OUT OVER MT/WY WORKING ACROSS MN DURING
THE LATE AFTERNOON/EARLY EVENING. 07.00 NAM SOUNDINGS SHOW A RATHER
UNSTABLE ENVIRONMENT BEING IN PLACE AS THESE WAVES APPROACH...WITH
2000-3000+ J/KG OF UNCAPPED SBCAPE BEING IN PLACE. AT THE SAME
TIME...RAP SOUNDINGS ONLY ABLE TO GENERATE 1500 J/KG AT BEST.
700-500 MB LAPSE RATES ARE MEAGER ON BOTH /ABOUT 6 DEG C PER
KM/...WITH THE DIFFERENCE COMING WITH HANDLING OF LOW LEVEL
MOISTURE...AS THE RAP LOOKS A LITTLE AGGRESSIVE ON MIXING OUT DEWPS
THIS AFTERNOON...WHICH IN TURN IS IMPACTING ITS INSTABILITY
FORECAST. NAM IDEA IS PROBABLY MORE REALISTIC...BUT GIVEN MID-LEVEL
LAPSE RATES...WOULD FAVOR 1500-2500 J/KG OF CAPE TO WORK WITH TODAY.
WITH ALL THAT SAID...AT THE MOMENT ONLY HAVE CHANCE POPS MENTIONED
IN THE FAR ERN CWA THIS AFTERNOON AS THIS IS WHERE SOME FORM OF LLJ
FORCING LOOKS TO RESIDE...BUT GIVEN THE INSTABILITY MENTIONED
ABOVE...COULD SEE STORMS DEVELOP ANYWHERE ALONG/SOUTH OF THE
STATIONARY BOUNDARY. 03Z HOPWRF ENSEMBLE REFLECTIVITY FORECASTS HINT
AT THIS HAPPENING...WITH SCATTERED CONVECTION SEEN AT 21Z ON MEMBERS
1/3/4 ACROSS MOST OF THE AREA. GUESS AT THIS POINT...THIS "WET
PATTERN" THAT SET IN FRIDAY NIGHT HAS NOT EXACTLY PRODUCED MUCH IN
THE WAY OF OBSERVABLE PRECIPITATION IN THE MPX AREA...SO AM A BIT
GUN SHY ON GOING TO HIGH WITH POPS AT THIS POINT. WITH LOW LEVEL
FLOW BACKING OFF CONSIDERABLY TODAY...LOW LEVEL SHEAR WILL BE PRETTY
WEAK TODAY...BUT WITH INVERTED V SOUNDINGS SEEN IN MODELS...A
CONDITIONAL WIND THREAT WOULD EXIST.
FOR TONIGHT...LLJ FORCING AND THICKNESS PATTERN CONTINUE TO SHOW THE
MPX AREA SPLIT BETWEEN BETTER REGIONS OF FORCING FOR CONVECTION OVER
NRN IL/SRN WI AND OUT WEST ACROSS THE DAKOTAS...SO EXPECT TONIGHT TO
BE DRY ONCE ANY DIURNALLY DRIVEN ACTIVITY DISSIPATES THIS EVENING.
FOR TEMPERATURES...DENSE MID LEVEL CLOUD COVER SHOULD CLEAR ERN
AREAS FAIRLY QUICKLY THIS MORNING...WITH A FAIR AMOUNT OF SUNSHINE
EXPECTED AS A RESULT. AIRMASS HAS CHANGED VERY LITTLE SINCE
YESTERDAY...SO EXPECT HIGHS TO BE VERY SIMILAR TO WHAT WAS SEEN
OUTSIDE OF CENTRAL MINNESOTA ON SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 409 AM CDT SUN JUL 7 2013
MAIN CHALLENGE IS TRYING TO PINPOINT THE TIMING AND PLACEMENT OF
POPS EARLY IN THE WEEK BEFORE WE DRY OUT WEDNESDAY THROUGH FRIDAY.
THE UPPER LEVEL RIDGE ANCHORED OVER THE DESERT SOUTHWEST WILL
REMAIN THROUGHOUT THE PERIOD. MONDAY SHOULD START OUT DRY AS THE
LOW LEVEL JET AS SEEN IN THE H925 WINDS AND MOISTURE TRANSPORT
WILL REMAIN WELL SOUTH OF THE FORECAST AREA IN SOUTHERN
IOWA/ILLINOIS. THE HUMID AIRMASS WILL PERSIST ACROSS THE UPPER
MIDWEST...AND WITH LITTLE MIXING EXPECTED ON MONDAY HAVE INCREASED
DEWPOINTS INTO THE LOW 70S. BY MONDAY EVENING FORECAST MODELS
INDICATE A SUBTLE H500 SHORTWAVE ROTATING AROUND THE PERIPHERY OF
THE AFOREMENTIONED MONSOON RIDGE AND THIS SHOULD TRIGGER OFF SOME
DEEP CONVECTION ON THE LEE SIDE OF THE ROCKIES WHICH WILL ADVECT
EASTWARD OVER THE HIGH PLAINS OF THE DAKOTAS...AND COULD REACH THE
CWA LATER MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE 07.12 GFS
AND ECMWF PLACE THE NOSE OF THE LOW LEVEL JET IN A FAVORABLE
LOCATION FOR CONVECTION OVER THE MISSISSIPPI RIVER VALLEY.
CURRENTLY HAVE THE HIGHEST POPS ALONG I90 NEAR THE IA BORDER...BUT
THESE MAY NEED TO BE ADJUSTED NORTHWARD IF THE MODELS FOLLOW THE
LEAD OF THE ECMWF...WHICH TAKES THE MCS ALONG AND NORTH OF I94.
THERE WILL BE PLENTY OF INSTABILITY AS SREF PLUMES KEEP AROUND
1000 J/KG OF MUCAPE ACROSS THE REGION MONDAY NIGHT...WITH ROUGHLY
30KTS OF DEEP LAYER SHEAR DEPENDING ON THE PLACEMENT OF THE LLJ.
THE FORECAST FOR TUESDAY BECOMES DIFFICULT SINCE MANY OF THE DETAILS
HINGES DIRECTLY ON THE MESOSCALE FEATURES LEFT IN THE WAKE OF THE
EARLY MORNING CONVECTION. A MORE WELL-DEFINED SHORTWAVE CURRENTLY
OFF THE MOVING DOWN THE COAST OF BRITISH COLUMBIA WILL TRANSLATE
EASTWARD IN THE ZONAL FLOW ALONG THE INTERNATIONAL BORDER AND ARRIVE
ACROSS THE UPPER MIDWEST TUESDAY AFTERNOON. THIS WILL DRIVE A COLD
FRONT THROUGH THE REGION ON TUESDAY...HOWEVER EXPECT ANY REMNANT
DEBRIS CLOUDS TO CLEAR OFF ALLOWING THE BOUNDARY LAYER TO RECOVER
DURING THE LATE MORNING HOURS...WITH AN UNSTABLE ENVIRONMENT SETTING
UP ACROSS THE MN/WI BORDER BY TUESDAY AFTERNOON. AN H500 SPEED MAX
OF 60KTS...ALONG WITH 3M/HR HEIGHT FALLS WILL PROVIDE SYNOPTIC SCALE
FORCING FOR SEVERE THUNDERSTORMS AHEAD OF THE COLD FRONT. AS ALLUDED
TO IN THE SPC DAY3 OUTLOOK...ANY OUTFLOW BOUNDARY PRODUCED BY THE
EARLY MORNING CONVECTION WILL BE THE FOCUS FOR AN ENHANCED THREAT OF
SEVERE WEATHER...INCLUDING TORNADOES AS THE SURFACE WINDS BACK AHEAD
OF THE COLD FRONT. NAM BUFR SOUNDINGS FOR TUESDAY AFTERNOON AT KRWF
SHOW A CYCLONICALLY CURVED HODOGRAPH WITH 0-3KM HELICITY OF OVER
300M2/S2. THE GFS IS FASTER WITH THE COLD FRONT...SO ITS LINEAR
SHEAR PROFILE WITH NORTHWEST WIND IS LESS FAVORABLE FOR
TORNADOES...BUT RATHER WOULD SUPPORT STRAIGHT LINE WINDS.
REGARDLESS...TUESDAY SEVERE THREAT LOOKS TO BE THE MAIN CONCERN
DURING THE EXTENDED.
NORTHWEST FLOW IN THE WAKE OF THIS COLD FRONT WILL USHER IN DRIER
AIR AS A CANADIAN HIGH PRESSURE BUILDS ON WEDNESDAY AND KEEPS THE
REGION DRY THROUGH FRIDAY. HAVE INCREASED WINDS SLIGHTLY ABOVE
GUIDANCE ON WEDNESDAY AS FORECAST SOUNDINGS SHOW ANOTHER GOOD MIXING
DAY. LOOKING AHEAD...THE REPRIEVE FROM THE HEAT AND HUMIDITY WILL BE
SHORTLIVED AS THE THERMAL RIDGE DEVELOPS BY THE END OF THE WORK WEEK
ACROSS THE HIGH PLAINS. WILL ACTUALLY SEE A WEST/EAST TEMPERATURE
GRADIENT BY THE WEEKEND...WITH MUCH WARMER TEMPERATURES ACROSS
WESTERN MINNESOTA. CURRENTLY HAVE MORE OF A BLENDED APPROACH WHICH
YIELDS ONLY MID 80S ACROSS THE WEST. THERE IS STILL
UNCERTAINTY...BUT IF THE H850 TEMPS REMAIN 20-22C WILL LIKELY SEE
HIGHS IN THE MID 90S NEAR THE MN/SD BORDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1247 AM CDT SUN JUL 7 2013
THUNDER THIS EVENING OVER LAKE SUPERIOR SITTING ON THE NOSE OF THE
LLJ...AND EXPECT IT TO REMAIN IN THAT DIRECTION...SO HAVE REMOVED
ANY MENTION OF PRECIP FROM TAFS. INSTEAD...CONCERN FOR TAFS IS THE
POTENTIAL FOR FOG ACROSS WRN/CENTRAL MN AS MID LEVEL CLOUDS SLOWLY
CLEAR OUT. UNDER THESE CLEAR SKIES...LIGHT WINDS WITH DEWPS IN THE
UPPER 60S/LOWER 70S HAS ALREADY ALLOWED FAIRLY EXPANSIVE BR/FG TO
DEVELOP FROM NRN BACK THRU WRN MN. ADDED SOME IFR VIS FOR
AXN/STC...BUT THEY COULD END UP MUCH WORSE THAN THAT. FOR THE
AFTERNOON...MODELS ARE NOT ALL THAT EXCITED ABOUT STORMS...BUT THE
NAM/GFS SHOW A SHORT WAVE CURRENTLY OUT OVER WYOMING CROSSING MN
DURING PEAK HEATING...AS THE WEAK SFC BOUNDARY SITS FROM SRN/ERN
MN UP INTO NRN WI. THIS MAY ALLOW FOR ISO/SCT TSRA DEVELOPMENT
LATE IN THE AFTERNOON FOR MSP/EAU/RNH. CONFIDENCE IN THIS
HAPPENING IS LOW AT THE MOMENT...BUT WILL GIVE ME SOMETHING TO
CHEW ON FOR THE 12Z TAFS. SUNDAY NIGHT WILL BE SIMILAR TO TONIGHT
WITH LIGHT WINDS AND HIGH DEWPS...SO MAY HAVE TO BRING BACK SOME
BR INTO THE TAFS AGAIN.
KMSP...CONFIDENCE HIGH IN THE REST OF THE NIGHT BEING DRY AND VFR
WITH S WINDS SLOWLY VEERING AS THEY SLACKEN OFF. THERE IS THE
POTENTIAL FOR A STRAY THUNDERSTORM IN THE AREA SUN EVENING...MAINLY
BETWEEN 22Z AND 02Z...BUT CONFIDENCE IN THEIR OCCURRENCE NOT HIGH
ENOUGH TO INCLUDE IN THE TAF. BY MONDAY MORNING...WITH LIGHT WINDS
AND HIGH DEWPS...MAY SEE VIS IN HZ/BR MAKE A RUN FOR 4 OR 5 SM
MONDAY MORNING.
/OUTLOOK FOR KMSP/
MON...MVFR VIS POSSIBLE EARLY. CHC TSRA LATE NIGHT. WINDS E 5 KTS.
TUE...TSRA LIKELY. VFR OUTSIDE OF TSRA. WINDS SE BCMG NW AT 5 KTS.
WED...VFR. WINDS NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS GLASGOW MT
850 PM MDT MON JUL 8 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
900PM UPDATE...
SEVERE THUNDERSTORM WATCH HAS BEEN DROPPED. MOST OF THE
THUNDERSTORM ACTIVITY HAS BECOME SUB-SEVERE AND/OR IS EXITING THE
CWA TO THE EAST. ONE FINAL ROUND OF SHOWERS AND THUNDERSTORMS IS
APPROACHING PHILLIPS AND PETROLEUM COUNTIES AND WILL TRAVERSE THE
CWA THROUGH THE OVERNIGHT HOURS IF IT HOLDS TOGETHER. NOT
EXPECTING MUCH MORE SEVERE...BUT SOME ISOLATED SMALL HAIL AND
GUSTY WINDS ARE POSSIBLE. THEREAFTER...UPPER LEVEL RIDGING BUILDS
INTO NORTHEAST MONTANA BRINGING IN DRIER CONDITIONS UNDER LARGE
SCALE SUBSIDENCE AND WARMING TEMPERATURES TOWARD THE MIDDLE OF THE
WEEK. MALIAWCO
700PM UPDATE...
SEVERE THUNDERSTORM WATCH HAS BEEN EXTENDED UNTIL 9PM FOR MCCONE
AND PRAIRIE COUNTIES AND POINTS EASTWARD. THE MOST INTENSE STORMS
LOOK TO HAVE JUST PUSHED OUTSIDE OF THE CWA. ANOTHER LINE OF
SHOWERS AND STORMS EXISTS IN PRAIRIE COUNTY EXTENDING NORTHWARD
THROUGH DANIELS AND SHERIDAN COUNTY. LOOKS LIKE IT HAS BECOME
STABLE ENOUGH THOUGH THAT IN ROOSEVELT COUNTY AND AREAS
NORTH...THAT THE MAIN CONCERN WILL ONLY BE A STEADY RAIN WITH SOME
EMBEDDED THUNDER POSSIBLE. ANOTHER LINE OF SHOWERS/STORMS ACROSS
CENTRAL MONTANA WILL MOVE THROUGH THE CWA BETWEEN NOW AND
MIDNIGHT. DID NOT MAKE ANY REAL CHANGES TO THE GRIDS AT THIS TIME.
POPS STILL LOOK OKAY AS THAT LAST ROUND OF SHOWERS/STORMS WILL
LIKELY BE CONFINED TO EASTERN/CENTRAL ZONES AFTER MIDNIGHT. MALIAWCO
430PM UPDATE...
SEVERE THUNDERSTORM WATCH WAS JUST EXTENDED TO INCLUDE DANIELS AND
SHERIDAN COUNTIES UNTIL 7PM. FORECAST APPEARS ON TRACK SO NO OTHER
CHANGES AT THIS TIME. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
PUSH FROM WEST TO EAST ACROSS THE CWA THIS EVENING AND TONIGHT.
SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL...VERY LARGE
HAIL...AND STRONG WINDS. REPORTS OF GOLF BALL TO BASEBALL SIZED
HAIL HAVE COME IN THIS EVENING WITH A STORM THAT PUSHED THROUGH
NORTHEASTERN GARFIELD COUNTY AND INTO SOUTHERN MCCONE COUNTY. THIS
STORM IS CURRENTLY THE STRONGEST STORM IN THE FORECAST REGION AND
WILL BE MOVING SOUTHEAST INTO SOUTHERN DAWSON AND NORTHERN PRAIRIE
COUNTIES. ADDITIONAL SHOWERS AND STORMS EXIST IN A LINE FROM JUST
WEST OF THE PORT OF OPHEIM EXTENDING DOWN THROUGH PETROLEUM
COUNTY. SOME OF THESE STORMS MAY BECOME SEVERE AS WELL AS THEY
MARCH EASTWARD THROUGH THE EVENING. WILL UPDATE AS NEEDED.
MALIAWCO
MAIN FOCUS FOR THE SHORT TERM PERIOD IS A STRONG UPPER LEVEL
SHORTWAVE FEATURE PUSHING INTO WESTERN MONTANA THIS AFTERNOON. OUT
AHEAD OF THIS WAVE THERE IS ENOUGH INSTABILITY TO GENERATE SOME
SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS SHOW VERY GOOD
CAPE/DIRECTIONAL WIND SHEAR PROFILES THROUGH TONIGHT AND
PRECIPITABLE WATER VALUES OF GREATER THAN ONE INCH. ALSO GIVEN
SEVERE THUNDERSTORM WATCH UNTIL 7PM FOR MOST OF THE CWA EXCEPT FOR
DANIELS AND SHERIDAN COUNTIES...WILL NEED TO MONITOR FOR SOME
STORMS TO PRODUCE LARGE HAIL...STRONG WINDS...AND VERY HEAVY
RAINFALL. SPC STORM SCALE ENSEMBLE OF OPPORTUNITY PRODUCT SHOWS
CONSISTENCY WITH LATEST HRRR AND NAM MODEL SOLUTIONS. EXPECT MOST
OF THE ACTIVITY TO OCCUR PRIOR TO MIDNIGHT. BEYOND
MIDNIGHT...CANNOT RULE OUT SHOWERS AND STORMS BUT THEY SHOULD
REDUCE IN COVERAGE AND SEVERE POTENTIAL WILL LIKELY BE LIMITED BY
THAT TIME.
TUESDAY AND WEDNESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS
WILL EXIT THE CWA DURING THE MORNING HOURS ON TUESDAY.
THEREAFTER...MODELS DEPICT AN UPPER LEVEL RIDGE BUILDING INTO THE
CWA WHICH WILL LEAD TO AN ABUNDANCE OF SUNSHINE...DRIER
CONDITIONS...AND WARMING TEMPERATURES UNDER A REGIME OF LARGE
SCALE SUBSIDENCE. DID NOT MAKE MANY CHANGES TO THIS PORTION OF THE FORECAST
DUE TO THE PRIMARY CONCENTRATION ON THE SEVERE WEATHER POTENTIAL
FOR THIS AFTERNOON INTO TONIGHT. WILL MAKE UPDATES AS NEEDED AS
CONDITIONS WARRENT. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME OVER
THE DESERT SOUTHWEST AND INTERMOUNTAIN WEST. A RIDGE SPUR IS
ANTICIPATED TO JUT OUT OF THE DOME OVER THE HIGH PLAINS OF MONTANA
AND ALBERTA. A CLOSED LOW IS EXPECTED OVER THE COAST OF BRITISH
COLUMBIA AND THE PACIFIC NORTHWEST.
WEDNESDAY NIGHT INTO THURSDAY... DRY CONDITIONS ARE ANTICIPATED
UNTIL THURSDAY AS NORTHEAST MONTANA COMES UNDER THE FULL OF AND
INCREASING RIDGE. THURSDAY... THE AXIS OF THE RIDGE WILL PASS
THROUGH AND ALLOW FOR A ISOLATED THUNDERSTORMS TO DEVELOP ON THE
AXIS. THURSDAY ALSO LOOKS TO BE VERY WARM AHEAD OF THE AXIS WITH
UPPER 90S AND POSSIBLE AS 850 MB TEMPERATURES REACH INTO THE 30*
CELSIUS RANGE.
THURSDAY NIGHT INTO SATURDAY...CLOSED LOW OVER THE PACIFIC
NORTHWEST IS ANTICIPATED TO MOVE EAST THROUGH WEST MONTANA INTO
THE HIGH PLAINS... EXITING THE RIDGE ALOFT OVER THE GREAT PLAINS.
THIS WILL PLACE NORTHEAST MONTANA IN A SOUTHWEST FLOW WITH A WEAK
TROUGHS AND SHORTWAVES MOVING THROUGH THE FLOW. A SHORTWAVE IS
CURRENTLY TIMED ON FRIDAY WITH THE BASE OF THE LARGE TROUGH
MOVING THROUGH SATURDAY HOWEVER... TIMING OF THESE WAVES COULD
EASILY SHIFT AS THE LAST COUPLE RUNS HAVE ALREADY MOVED THEM
AROUND.
SATURDAY NIGHT ONWARD... THE TROUGH IS ANTICIPATED TO PASS OFF TO
THE EAST AND REPRESS THE HEAT TO THE SOUTH WHILE A NEW RIDGE
BUILDS OVER THE PACIFIC NORTHWEST. THIS WILL GENERATE ZONAL TO
NORTHWEST FLOW ACROSS NORTHEAST MONTANA. CONDITIONS WILL BE DRY
SLIGHTLY WITH A WEAK WARMING TREND. GAH
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. TEMPORARY
REDUCTIONS IN VISIBILITIES ARE POSSIBLE IN HEAVIER SHOWERS AND
THUNDERSTORMS OVERNIGHT...BUT THAT POTENTIAL WILL COME TO AN
END...ESPECIALLY AFTER MIDNIGHT. DO EXPECT LIGHT WINDS OVERNIGHT
FROM THE WEST TONIGHT AND BECOMING NORTHWEST ON TUESDAY. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
706 PM MDT MON JUL 8 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
700PM UPDATE...
SEVERE THUNDERSTORM WATCH HAS BEEN EXTENDED UNTIL 9PM FOR MCCONE
AND PRAIRIE COUNTIES AND POINTS EASTWARD. THE MOST INTENSE STORMS
LOOK TO HAVE JUST PUSHED OUTSIDE OF THE CWA. ANOTHER LINE OF
SHOWERS AND STORMS EXISTS IN PRAIRIE COUNTY EXTENDING NORTHWARD
THROUGH DANIELS AND SHERIDAN COUNTY. LOOKS LIKE IT HAS BECOME
STABLE ENOUGH THOUGH THAT IN ROOSEVELT COUNTY AND AREAS
NORTH...THAT THE MAIN CONCERN WILL ONLY BE A STEADY RAIN WITH SOME
EMBEDDED THUNDER POSSIBLE. ANOTHER LINE OF SHOWERS/STORMS ACROSS
CENTRAL MONTANA WILL MOVE THROUGH THE CWA BETWEEN NOW AND
MIDNIGHT. DID NOT MAKE ANY REAL CHANGES TO THE GRIDS AT THIS TIME.
POPS STILL LOOK OKAY AS THAT LAST ROUND OF SHOWERS/STORMS WILL
LIKELY BE CONFINED TO EASTERN/CENTRAL ZONES AFTER MIDNIGHT. MALIAWCO
430PM UPDATE...
SEVERE THUNDERSTORM WATCH WAS JUST EXTENDED TO INCLUDE DANIELS AND
SHERIDAN COUNTIES UNTIL 7PM. FORECAST APPEARS ON TRACK SO NO OTHER
CHANGES AT THIS TIME. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
PUSH FROM WEST TO EAST ACROSS THE CWA THIS EVENING AND TONIGHT.
SOME STORMS WILL PRODUCE LOCALLY HEAVY RAINFALL...VERY LARGE
HAIL...AND STRONG WINDS. REPORTS OF GOLF BALL TO BASEBALL SIZED
HAIL HAVE COME IN THIS EVENING WITH A STORM THAT PUSHED THROUGH
NORTHEASTERN GARFIELD COUNTY AND INTO SOUTHERN MCCONE COUNTY. THIS
STORM IS CURRENTLY THE STRONGEST STORM IN THE FORECAST REGION AND
WILL BE MOVING SOUTHEAST INTO SOUTHERN DAWSON AND NORTHERN PRAIRIE
COUNTIES. ADDITIONAL SHOWERS AND STORMS EXIST IN A LINE FROM JUST
WEST OF THE PORT OF OPHEIM EXTENDING DOWN THROUGH PETROLEUM
COUNTY. SOME OF THESE STORMS MAY BECOME SEVERE AS WELL AS THEY
MARCH EASTWARD THROUGH THE EVENING. WILL UPDATE AS NEEDED.
MALIAWCO
MAIN FOCUS FOR THE SHORT TERM PERIOD IS A STRONG UPPER LEVEL
SHORTWAVE FEATURE PUSHING INTO WESTERN MONTANA THIS AFTERNOON. OUT
AHEAD OF THIS WAVE THERE IS ENOUGH INSTABILITY TO GENERATE SOME
SHOWERS AND THUNDERSTORMS. FORECAST SOUNDINGS SHOW VERY GOOD
CAPE/DIRECTIONAL WIND SHEAR PROFILES THROUGH TONIGHT AND
PRECIPITABLE WATER VALUES OF GREATER THAN ONE INCH. ALSO GIVEN
SEVERE THUNDERSTORM WATCH UNTIL 7PM FOR MOST OF THE CWA EXCEPT FOR
DANIELS AND SHERIDAN COUNTIES...WILL NEED TO MONITOR FOR SOME
STORMS TO PRODUCE LARGE HAIL...STRONG WINDS...AND VERY HEAVY
RAINFALL. SPC STORM SCALE ENSEMBLE OF OPPORTUNITY PRODUCT SHOWS
CONSISTENCY WITH LATEST HRRR AND NAM MODEL SOLUTIONS. EXPECT MOST
OF THE ACTIVITY TO OCCUR PRIOR TO MIDNIGHT. BEYOND
MIDNIGHT...CANNOT RULE OUT SHOWERS AND STORMS BUT THEY SHOULD
REDUCE IN COVERAGE AND SEVERE POTENTIAL WILL LIKELY BE LIMITED BY
THAT TIME.
TUESDAY AND WEDNESDAY...ANY LEFTOVER SHOWERS AND THUNDERSTORMS
WILL EXIT THE CWA DURING THE MORNING HOURS ON TUESDAY.
THEREAFTER...MODELS DEPICT AN UPPER LEVEL RIDGE BUILDING INTO THE
CWA WHICH WILL LEAD TO AN ABUNDANCE OF SUNSHINE...DRIER
CONDITIONS...AND WARMING TEMPERATURES UNDER A REGIME OF LARGE
SCALE SUBSIDENCE. DID NOT MAKE MANY CHANGES TO THIS PORTION OF THE FORECAST
DUE TO THE PRIMARY CONCENTRATION ON THE SEVERE WEATHER POTENTIAL
FOR THIS AFTERNOON INTO TONIGHT. WILL MAKE UPDATES AS NEEDED AS
CONDITIONS WARRENT. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME OVER
THE DESERT SOUTHWEST AND INTERMOUNTAIN WEST. A RIDGE SPUR IS
ANTICIPATED TO JUT OUT OF THE DOME OVER THE HIGH PLAINS OF MONTANA
AND ALBERTA. A CLOSED LOW IS EXPECTED OVER THE COAST OF BRITISH
COLUMBIA AND THE PACIFIC NORTHWEST.
WEDNESDAY NIGHT INTO THURSDAY... DRY CONDITIONS ARE ANTICIPATED
UNTIL THURSDAY AS NORTHEAST MONTANA COMES UNDER THE FULL OF AND
INCREASING RIDGE. THURSDAY... THE AXIS OF THE RIDGE WILL PASS
THROUGH AND ALLOW FOR A ISOLATED THUNDERSTORMS TO DEVELOP ON THE
AXIS. THURSDAY ALSO LOOKS TO BE VERY WARM AHEAD OF THE AXIS WITH
UPPER 90S AND POSSIBLE AS 850 MB TEMPERATURES REACH INTO THE 30*
CELSIUS RANGE.
THURSDAY NIGHT INTO SATURDAY...CLOSED LOW OVER THE PACIFIC
NORTHWEST IS ANTICIPATED TO MOVE EAST THROUGH WEST MONTANA INTO
THE HIGH PLAINS... EXITING THE RIDGE ALOFT OVER THE GREAT PLAINS.
THIS WILL PLACE NORTHEAST MONTANA IN A SOUTHWEST FLOW WITH A WEAK
TROUGHS AND SHORTWAVES MOVING THROUGH THE FLOW. A SHORTWAVE IS
CURRENTLY TIMED ON FRIDAY WITH THE BASE OF THE LARGE TROUGH
MOVING THROUGH SATURDAY HOWEVER... TIMING OF THESE WAVES COULD
EASILY SHIFT AS THE LAST COUPLE RUNS HAVE ALREADY MOVED THEM
AROUND.
SATURDAY NIGHT ONWARD... THE TROUGH IS ANTICIPATED TO PASS OFF TO
THE EAST AND REPRESS THE HEAT TO THE SOUTH WHILE A NEW RIDGE
BUILDS OVER THE PACIFIC NORTHWEST. THIS WILL GENERATE ZONAL TO
NORTHWEST FLOW ACROSS NORTHEAST MONTANA. CONDITIONS WILL BE DRY
SLIGHTLY WITH A WEAK WARMING TREND. GAH
&&
.AVIATION...
VFR. ISOLATED THUNDERSTORMS CAN BE EXPECTED OFF AND ON THROUGH THE
DAY WITH FEW SIGNIFICANT IMPACTS THROUGH 18Z. 21Z-06Z...HOWEVER A
LINE OR COMPLEX OF SEVERE THUNDERSTORMS IS EXPECTED TO ROLL ACROSS
NORTHEAST MONTANA. 23-01Z FOR KGGW... 00Z-02Z FOR KOLF... AND
01-03Z FOR KSDY/KGDV BASED ON THE CURRENT GUIDANCE. DO EXPECT
SIGNIFICANT IMPACTS TO FLIGHT OPERATIONS LATE THIS AFTERNOON AND
THROUGH THE EVENING HOURS WITH THESE THUNDERSTORMS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
407 PM MDT SUN JUL 7 2013
.SHORT TERM...VALID FOR MON AND TUE...
MAIN FORECAST ISSUE IS SEVERE WX POTENTIAL THIS AFTERNOON/EVENING
AND AGAIN TOMORROW.
WATER VAPOR IMAGERY SHOWS WSW FLOW ALOFT WITH SHORTWAVE ENERGY
APPROACHING FROM THE GREAT BASIN. A STRONGER TROF CAN BE SEEN
ALONG THE PAC NW COAST...AND THIS FEATURE WILL BE A PLAYER FOR US
MONDAY AND MONDAY NIGHT. PWATS IN PLACE ARE QUITE HIGH AND IN THE
VICINITY OF AN INCH...PERHAPS A BIT HIGHER IN OUR EAST. LOW LEVEL
E-SE WINDS ARE INCREASING...PROVIDING GREATER SHEAR AND LOW LEVEL
MOISTURE THAN WE SAW ON SATURDAY...AND LATEST 850MB ANALYSIS
SUGGESTS NOSE OF 850MB DEWPTS TO +13C IN FAR SE MT. WE REMAIN
UNDER RRQ OF 60KT H3 JET TO OUR NORTH...THUS MODEST SYNOPTIC
ASCENT IS PRESENT. OVERALL INGREDIENTS ARE IN PLACE FOR SEVERE
WEATHER LATE THIS AFTN AND EVENING. RECENT HRRR RUNS AGREE WITH
THIS ASSESSMENT AND HAVE BEEN CONSISTENT.
CONVECTION BEGINNING TO INITIATE OVER OUR SW MTNS WITH A FEW
LIGHTNING STRIKES NOTED SOUTH OF LIVINGSTON. A LONE CELL HAS
EMERGED FROM THE CU FIELD SE OF BROADUS. WILL BE INTERESTING TO
SEE WHAT SERN CELL WILL DO OVER THE NEXT COUPLE HOURS...SFC TEMPS
NEAR THE MID 80S MAY BE ENOUGH TO BREAK CAP THAT HAS BEEN IN
PLACE. OTHERWISE FOCUS SHOULD BE IN OUR WEST AS ACTIVITY SPREADS
OFF THE HIGH TERRAIN...SHIFTING EAST OVER TIME.
GREATEST SEVERE POTENTIAL THIS AFTN AND EVENING WILL BE EAST OF
BILLINGS IN REGION OF GREATER INSTABILITY AND SHEAR...ESPECIALLY
AS LOW LEVEL JET KICKS IN THIS EVENING. FOR MONDAY...OUR ENTIRE
AREA WILL BE AT AN ELEVATED RISK FOR SEVERE STORMS DUE TO
COMBINATION OF ASCENT FROM PAC NW TROF AND SURFACE COLD FRONT.
LARGE HAIL AND DAMAGING WINDS MAIN THREATS. HEAVY RAIN WILL
CONTINUE TO BE A POSSIBILITY BOTH TODAY AND TOMORROW DUE TO THE
MOISTURE RICH AIRMASS IN PLACE.
PASSAGE OF TROF...SURGE OF DRIER AIR AND SHIFT TO NW FLOW ALOFT
WILL SIGNAL THE BEGINNINGS OF A PATTERN SHIFT ON TUESDAY...AS THE
MOIST AIRMASS FINALLY GETS CLEANED OUT. COULD BE SOME MORNING
SHOWERS ON TUESDAY ALONG PV MAX...BUT OTHERWISE EXPECT DRIER AND
MORE STABLE CONDITIONS AS COOLER SFC RIDGE BUILDS IN FROM THE NW.
HAVE LOWERED POPS TUESDAY AFTERNOON AND NIGHT.
AS FOR TEMPS...MONDAY WILL BE THE WARMER OF THE NEXT TWO DAYS...
WITH PREFRONTAL CONDITIONS PERHAPS ALLOWING FOR TEMPS NEAR 90F.
TUESDAY WILL BE POSTFRONTAL AND COOLER WITH UPPER 70S TO MID 80S
FOR HIGHS...OR A LITTLE BELOW NORMAL.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MINIMAL CHANGES TO THE EXTENDED PERIOD...DUE IN LARGE PART TO
MODEL INCONSISTENCY FOR LATTER PORTIONS OF THE PERIOD.
THE PERIOD BEGINS WED UNDER AN UPPER LEVEL RIDGE...SO EXPECT HOT
AND MAINLY DRY CONDITIONS. MODELS DO SHOW SOME SHORTWAVE ACTIVITY
ROUNDING THE RIDGE...WITH SE LOW LEVEL FLOW OVER SOUTHEAST MONTANA
LATE WED AFTN/EVE...SO I KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS THE SE. RIDGING DOMINATES
THROUGH MUCH OF THE DAY THURS...SO HOT AND DRY CONDITIONS WILL
AGAIN BE THE RULE. A WEAK COLD FRONT...ALONG WITH SHORTWAVE
ACTIVITY...WILL MOVE ACROSS THE REGION THURS NIGHT...SO WE MAY SEE
SOME CONVECTIVE ACTIVITY THURS EVE/NIGHT OVER THE WESTERN
MOUNTAINS...AND OVER THE EAST...WHERE SHEAR IS BETTER AND THE
ATMOSPHERE IS LESS CAPPED. FRI LOOKS TO BE A TAD COOLER BEHIND THE
FRONT...BUT STILL QUITE WARM.
MODEL SOLUTIONS DIVERGE SAT AND SUN. THE ECMWF BRINGS ANOTHER
COLD FRONT THROUGH THE REGION SAT AND KEEP THE REGION UNDER THE
INFLUENCE OF A WEAK UPPER LEVEL TROF SUN. MEANWHILE...THE GFS
KEEPS THE AREA MAINLY UNDER THE INFLUENCE OF SOUTHWESTERLY FLOW
ALOFT AROUND AN UPPER LEVEL RIDGE. BECAUSE OF THE LARGE MODEL
DIFFERENCES...I LEFT THE FORECAST FROM SAT TO THE END OF THE
EXTENDED PRETTY MUCH AS I INHERITED IT.
TEMPS WED AND THURS LOOK TO BE IN THE MID 80S TO MID 90S...WITH
SLIGHTLY COOLER WEATHER FRI. NOT QUITE SURE WHAT TEMPS WILL BE SAT
AND SUN. IF THE GFS IS CORRECT...UPPER 80S TO 90S. IF THE ECMWF
IS CORRECT...UPPER 70S TO MID 80S. FOR NOW...KEPT SAT AND SUN
TEMPS IN THE MID 80S TO AROUND 90...SORT OF A BLEND OF THE GFS AND
ECMWF. STC
&&
.AVIATION...
THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE REGION...AND MOVE EASTWARD THROUGH THE
LATE AFTERNOON/EVENING HOURS. SOME OF THE STORMS WILL CONTAIN
HAIL AND ERRATIC...GUSTY WINDS AND HEAVY PRECIP...WHICH MAY
PRODUCE BRIEF IFR/LIFR FLIGHT CONDITIONS. VFR CONDITIONS WILL
PREVAIL OUTSIDE OF THUNDERSTORMS. MORE THUNDERSTORMS ARE
ANTICIPATED ACROSS THE REGION TOMORROW AFTERNOON/EVENING AHEAD OF
A COLD FRONT. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 062/089 061/084 059/091 064/094 064/090 061/091 060/089
43/T 32/T 11/U 11/B 22/T 22/T 22/T
LVM 053/088 050/085 048/091 056/094 052/090 051/091 050/089
43/T 31/B 11/U 11/B 22/T 22/T 22/T
HDN 060/091 061/085 056/092 064/095 064/091 061/092 060/090
43/T 32/T 11/U 11/B 22/T 22/T 22/T
MLS 065/088 062/084 059/092 066/095 063/090 062/091 061/089
44/T 53/T 11/U 12/T 22/T 22/T 22/T
4BQ 061/090 060/084 056/090 062/093 063/089 061/090 060/088
53/T 43/T 11/U 12/T 22/T 22/T 33/T
BHK 060/084 060/079 055/086 061/089 063/085 062/086 061/084
54/T 54/T 12/T 22/T 22/T 22/T 33/T
SHR 056/090 056/083 052/089 059/093 058/089 056/090 055/088
43/T 32/T 11/U 11/U 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 28>42-56>58-63>68.
WY...SEVERE THUNDERSTORM WATCH 396 IN EFFECT UNTIL 11 PM MDT THIS
EVENING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
221 PM MDT SUN JUL 7 2013
.SHORT TERM...VALID FOR MON AND TUE...
MAIN FORECAST ISSUE IS SEVERE WX POTENTIAL THIS AFTERNOON/EVENING
AND AGAIN TOMORROW.
WATER VAPOR IMAGERY SHOWS WSW FLOW ALOFT WITH SHORTWAVE ENERGY
APPROACHING FROM THE GREAT BASIN. A STRONGER TROF CAN BE SEEN
ALONG THE PAC NW COAST...AND THIS FEATURE WILL BE A PLAYER FOR US
MONDAY AND MONDAY NIGHT. PWATS IN PLACE ARE QUITE HIGH AND IN THE
VICINITY OF AN INCH...PERHAPS A BIT HIGHER IN OUR EAST. LOW LEVEL
E-SE WINDS ARE INCREASING...PROVIDING GREATER SHEAR AND LOW LEVEL
MOISTURE THAN WE SAW ON SATURDAY...AND LATEST 850MB ANALYSIS
SUGGESTS NOSE OF 850MB DEWPTS TO +13C IN FAR SE MT. WE REMAIN
UNDER RRQ OF 60KT H3 JET TO OUR NORTH...THUS MODEST SYNOPTIC
ASCENT IS PRESENT. OVERALL INGREDIENTS ARE IN PLACE FOR SEVERE
WEATHER LATE THIS AFTN AND EVENING. RECENT HRRR RUNS AGREE WITH
THIS ASSESSMENT AND HAVE BEEN CONSISTENT.
CONVECTION BEGINNING TO INITIATE OVER OUR SW MTNS WITH A FEW
LIGHTNING STRIKES NOTED SOUTH OF LIVINGSTON. A LONE CELL HAS
EMERGED FROM THE CU FIELD SE OF BROADUS. WILL BE INTERESTING TO
SEE WHAT SERN CELL WILL DO OVER THE NEXT COUPLE HOURS...SFC TEMPS
NEAR THE MID 80S MAY BE ENOUGH TO BREAK CAP THAT HAS BEEN IN
PLACE. OTHERWISE FOCUS SHOULD BE IN OUR WEST AS ACTIVITY SPREADS
OFF THE HIGH TERRAIN...SHIFTING EAST OVER TIME.
GREATEST SEVERE POTENTIAL THIS AFTN AND EVENING WILL BE EAST OF
BILLINGS IN REGION OF GREATER INSTABILITY AND SHEAR...ESPECIALLY
AS LOW LEVEL JET KICKS IN THIS EVENING. FOR MONDAY...OUR ENTIRE
AREA WILL BE AT AN ELEVATED RISK FOR SEVERE STORMS DUE TO
COMBINATION OF ASCENT FROM PAC NW TROF AND SURFACE COLD FRONT.
LARGE HAIL AND DAMAGING WINDS MAIN THREATS. HEAVY RAIN WILL
CONTINUE TO BE A POSSIBILITY BOTH TODAY AND TOMORROW DUE TO THE
MOISTURE RICH AIRMASS IN PLACE.
PASSAGE OF TROF...SURGE OF DRIER AIR AND SHIFT TO NW FLOW ALOFT
WILL SIGNAL THE BEGINNINGS OF A PATTERN SHIFT ON TUESDAY...AS THE
MOIST AIRMASS FINALLY GETS CLEANED OUT. COULD BE SOME MORNING
SHOWERS ON TUESDAY ALONG PV MAX...BUT OTHERWISE EXPECT DRIER AND
MORE STABLE CONDITIONS AS COOLER SFC RIDGE BUILDS IN FROM THE NW.
HAVE LOWERED POPS TUESDAY AFTERNOON AND NIGHT.
AS FOR TEMPS...MONDAY WILL BE THE WARMER OF THE NEXT TWO DAYS...
WITH PREFRONTAL CONDITIONS PERHAPS ALLOWING FOR TEMPS NEAR 90F.
TUESDAY WILL BE POSTFRONTAL AND COOLER WITH UPPER 70S TO MID 80S
FOR HIGHS...OR A LITTLE BELOW NORMAL.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MINIMAL CHANGES TO THE EXTENDED PERIOD...DUE IN LARGE PART TO
MODEL INCONSISTENCY FOR LATTER PORTIONS OF THE PERIOD.
THE PERIOD BEGINS WED UNDER AN UPPER LEVEL RIDGE...SO EXPECT HOT
AND MAINLY DRY CONDITIONS. MODELS DO SHOW SOME SHORTWAVE ACTIVITY
ROUNDING THE RIDGE...WITH SE LOW LEVEL FLOW OVER SOUTHEAST MONTANA
LATE WED AFTN/EVE...SO I KEPT A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS THE SE. RIDGING DOMINATES
THROUGH MUCH OF THE DAY THURS...SO HOT AND DRY CONDITIONS WILL
AGAIN BE THE RULE. A WEAK COLD FRONT...ALONG WITH SHORTWAVE
ACTIVITY...WILL MOVE ACROSS THE REGION THURS NIGHT...SO WE MAY SEE
SOME CONVECTIVE ACTIVITY THURS EVE/NIGHT OVER THE WESTERN
MOUNTAINS...AND OVER THE EAST...WHERE SHEAR IS BETTER AND THE
ATMOSPHERE IS LESS CAPPED. FRI LOOKS TO BE A TAD COOLER BEHIND THE
FRONT...BUT STILL QUITE WARM.
MODEL SOLUTIONS DIVERGE SAT AND SUN. THE ECMWF BRINGS ANOTHER
COLD FRONT THROUGH THE REGION SAT AND KEEP THE REGION UNDER THE
INFLUENCE OF A WEAK UPPER LEVEL TROF SUN. MEANWHILE...THE GFS
KEEPS THE AREA MAINLY UNDER THE INFLUENCE OF SOUTHWESTERLY FLOW
ALOFT AROUND AN UPPER LEVEL RIDGE. BECAUSE OF THE LARGE MODEL
DIFFERENCES...I LEFT THE FORECAST FROM SAT TO THE END OF THE
EXTENDED PRETTY MUCH AS I INHERITED IT.
TEMPS WED AND THURS LOOK TO BE IN THE MID 80S TO MID 90S...WITH
SLIGHTLY COOLER WEATHER FRI. NOT QUITE SURE WHAT TEMPS WILL BE SAT
AND SUN. IF THE GFS IS CORRECT...UPPER 80S TO 90S. IF THE ECMWF
IS CORRECT...UPPER 70S TO MID 80S. FOR NOW...KEPT SAT AND SUN
TEMPS IN THE MID 80S TO AROUND 90...SORT OF A BLEND OF THE GFS AND
ECMWF. STC
&&
.AVIATION...
THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE REGION...AND MOVE EASTWARD THROUGH THE
LATE AFTERNOON/EVENING HOURS. SOME OF THE STORMS WILL CONTAIN
HAIL AND ERRATIC...GUSTY WINDS AND HEAVY PRECIP...WHICH MAY
PRODUCE BRIEF IFR/LIFR FLIGHT CONDITIONS. VFR CONDITIONS WILL
PREVAIL OUTSIDE OF THUNDERSTORMS. MORE THUNDERSTORMS ARE
ANTICIPATED ACROSS THE REGION TOMORROW AFTERNOON/EVENING AHEAD OF
A COLD FRONT. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 062/089 061/084 059/091 064/094 064/090 061/091 060/089
43/T 32/T 11/U 11/B 22/T 22/T 22/T
LVM 053/088 050/085 048/091 056/094 052/090 051/091 050/089
43/T 31/B 11/U 11/B 22/T 22/T 22/T
HDN 060/091 061/085 056/092 064/095 064/091 061/092 060/090
43/T 32/T 11/U 11/B 22/T 22/T 22/T
MLS 065/088 062/084 059/092 066/095 063/090 062/091 061/089
44/T 53/T 11/U 12/T 22/T 22/T 22/T
4BQ 061/090 060/084 056/090 062/093 063/089 061/090 060/088
53/T 43/T 11/U 12/T 22/T 22/T 33/T
BHK 060/084 060/079 055/086 061/089 063/085 062/086 061/084
54/T 54/T 12/T 22/T 22/T 22/T 33/T
SHR 056/090 056/083 052/089 059/093 058/089 056/090 055/088
43/T 32/T 11/U 11/U 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
638 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
PLENTY OF THINGS TO PONDER DURING THE NEXT 24 HOURS...INCLUDING AT
LEAST ONE CONDITIONAL RISK FOR SEVERE STORMS THIS EVENING...AND
MAYBE ANOTHER SEVERE RISK ON TUESDAY AFTERNOON/EVENING...ALTHOUGH
CONFIDENCE IS QUITE LOW ON THE LIKELIHOOD/EVOLUTION OF THE LATTER.
IN OTHER DEPARTMENTS...TOMORROW IS CURRENTLY EXPECTED TO BE THE
OVERALL-HOTTEST AFTERNOON OF THE SUMMER SO FAR FOR MOST OF THE
CWA...AND A HEAT ADVISORY HAS BEEN ISSUES FOR SEVERAL
SOUTHERN/SOUTHEAST COUNTIES.
21Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SOMEWHAT SUBTLE-BUT
EVIDENT EAST-WEST QUASI STATIONARY GENERALLY STRETCHED ACROSS THE
SOUTHERN HALF OF NEBRASKA. IN THE WIND-FIELD...THIS BOUNDARY
SEPARATES A STEADY 15+ MPH SOUTHERLY BREEZE IN NORTH CENTRAL
KANSAS...FORM A LIGHTER...GENERALLY EAST-SOUTHEAST BREEZE WITHIN
MOST OF THE NEBRASKA CWA. ITS ALSO SOMEWHAT OF A MOISTURE
BOUNDARY...WITH MID-50S TO LOW 60S DEWPOINTS RESIDING IN THE
DEEPLY MIXED AIRMASS TO THE SOUTH...AND HIGHER DEWPOINTS MID-60S
TO NEAR 70 MOST AREAS ALONG/NORTH OF I-80. AS DISCUSSED EARLIER
TODAY...NEAR-CRITICAL FIRE DANGER WILL PERSIST FOR A FEW MORE
HOURS ESPECIALLY IN THE PHILLIPS/ROOKS COUNTY AREA IN KS. HIGH
TEMPS THIS AFTERNOON WORKED OUT PRETTY WELL ACROSS THE
SOUTHWESTERN 2/3 OF THE CWA RANGING GENERALLY 95-104
DEGREES...WHILE SOME NORTHEAST AREAS ARE STRUGGLING TO REACH 90
THANKS IN PART TO A BATCH OF MID LEVEL CLOUDS THAT FORMED ON THE
BACK-SIDE OF AN MCV THAT HAS MOVED WELL EAST INTO WESTERN IA.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRM
CONTINUED QUASI-ZONAL FLOW ACROSS THE LOCAL AREA...BETWEEN THE
LARGER-SCALE MID LEVEL RIDGE AXIS STRETCHED WEST-EAST FROM AZ TO
OK...AND A VIGOROUS SHORTWAVE TROUGH MAKING ITS WAY ACROSS THE
ID/MT/CANADA BORDER AREA. THE MAIN LOW-AMPLITUDE SHORTWAVE TROUGH
OF INTEREST FOR THIS EVENING IS CURRENTLY LIFTING OUT OF WY INTO
WESTERN NEB/SD.
LATE THIS AFTERNOON INTO THIS EVENING...THE PRIMARY FOCUS IS ON
HOW MUCH THUNDERSTORM COVERAGE THE CWA WILL SEE...AND WHETHER SOME
OF THIS ACTIVITY COULD BECOME SEVERE. AT PRESENT TIME...RADAR
INDICATES A FEW WEAK-ISH/HIGH-BASED STORMS NEAR THE STATE LINE IN
THE SOUTHWESTERN CWA...LARGELY A RESULT OF VERY STEEP LOW-LEVEL
LAPSE RATES IN THE HOT/DEEPLY MIXED AIRMASS OVER KS.
MEANWHILE...OFF TO THE NORTHWEST...A FEW STRONG TO SEVERE STORMS
HAVE TAKEN OFF IN NORTH CENTRAL/WESTERN NEB...IN AN ENVIRONMENT
CHARACTERIZED BY AROUND 2000+ J/KG MLCAPE AND 30+ KNOTS OF 0-6KM
DEEP LAYER SHEAR. LOCALLY...WITH THE EXCEPTION OF THE HIGH-BASED
STORMS IN OUR SOUTH...MODEL SOUNDINGS SUGGEST THERE IS JUST ENOUGH
OF A CAP IN PLACE TO KEEP CONVECTION FROM DEVELOPING OVERHEAD IN
MOST OF THE CENTRAL/NORTHERN CWA...AIDED IN PART BY SUBSIDENCE
BEHIND THE DEPARTING MCV. AS HAS BEEN THE CASE FOR DAYS
NOW...CONFIDENCE IN THE DETAILS IS LOW IN THIS WEAKLY FORCED
PATTERN...BUT TAKING CUE FROM THE LATEST RAP/HRRR AND 12Z 4KM WRF-
NMM...THE GENERAL EXPECTATION IS FOR MOST OF THE CWA TO REMAIN
STORM FREE THROUGH AT LEAST 00Z/7PM...BEFORE STORM CHANCES
GRADUALLY INCREASE THROUGH THE EVENING HOURS ESPECIALLY NEAR/NORTH
OF I-80...AND LIKELY MAINLY AS A FUNCTION OF ACTIVITY MOVING IN
FROM WESTERN NEBRASKA...ALTHOUGH LOCAL INITIATION NEAR THE SURFACE
BOUNDARY CANNOT BE RULED OUT EITHER. BOTH THE WRF-NMM AND HRRR ARE
FAIRLY AGGRESSIVE BRINGING A CLUSTER OF STORMS...POSSIBLY A SEMI-
ORGANIZED MCS ACROSS ESPECIALLY THE NORTHERN 1/2 OF THE CWA THIS
EVENING...BUT A SIMILAR MODEL DEPICTION YESTERDAY ENDED UP BEING A
BIT OVERDONE...AND THUS HAVE CAPPED POPS AT NO HIGHER THAN 50
PERCENT AT LEAST FOR NOW. WITH MLCAPE REMAINING 1000+ J/KG WELL
INTO THE EVENING HOURS AND WITH AT LEAST MODEST SHEAR...AT LEAST A
LOCALIZED LARGE HAIL AND ESPECIALLY A WIND THREAT IS QUITE
POSSIBLE ESPECIALLY IF STORMS TO THE WEST CAN ORGANIZE AND DEVELOP
A COLD POOL. AGREE WITH SPC IN HIGHLIGHTING THE NORTHERN 1/2 OF
THE CWA FOR THE GREATEST SEVERE THREAT...BUT JUST CANNOT RULE OUT
A STRONG TO SEVERE STORM ANYWHERE IN THE CWA THIS EVENING.
ALTHOUGH THE MAIN SEVERE THREAT SHOULD BE ON THE WANE BY
MIDNIGHT...LINGERED LOW POPS THROUGH THE NIGHT ESPECIALLY ACROSS
THE EASTERN 2/3 OF THE CWA TO ACCOUNT FOR ACTIVITY PERSISTING OR
NEWLY-DEVELOPING WITHIN THE LOW LEVEL JET AXIS...AND JUST AHEAD ON
APPROACHING COLD FRONT. IF NOTHING ELSE...HOPEFULLY PARTS OF THE
CWA CAN RECEIVE SOME MUCH-NEEDED RAINS TONIGHT...BECAUSE THIS MAY
BE ONE OF THE BETTER CHANCES FOR AWHILE. TEMPERATURE-WISE...MADE
ONLY MINOR TWEAKS TO LOWS...WITH THE PREVALENT LIGHT SOUTHERLY
BREEZE HOLDING MOST AREAS UP INTO THE 70-75 RANGE. ALTHOUGH AT
LEAST LIGHT FOG DEVELOPMENT CANNOT BE RULED OUT LATE TONIGHT
ESPECIALLY IN AREAS THAT RECEIVE RAIN...THE PROBABILITY/MAGNITUDE
SEEMED LOW ENOUGH TO OMIT FROM THE FORECAST.
TURNING TO TUESDAY DAYTIME...REALLY DON/T THINK SEVERE STORMS ARE
GOING TO END UP BEING MUCH OF A STORY...AT LEAST THROUGH THE VAST
MAJORITY OF THE DAY. ALOFT...QUASI-ZONAL FLOW WILL START TO TURN A
BIT MORE NORTHWESTERLY IN RESPONSE TO THE PASSAGE OF A FAIRLY
VIGOROUS SHORTWAVE TROUGH FROM EASTERN MT TOWARD NORTHERN MN. AT
THE SURFACE...A FAIRLY WEAK COLD FRONT...MORE EVIDENT IN THE WIND
FIELD THAN ON A THERMOMETER...WILL WORK SOUTHWARD ACROSS THE CWA
AS THE DAY WEARS ON...WITH MOST AREAS SEEING A FEW HOURS OF
LIGHT/VARIABLE WINDS BEFORE A SLIGHTLY MORE STEADY NORTHERLY
BREEZE SETTLES IN. ALONG AND ESPECIALLY JUST AHEAD OF THIS
BOUNDARY...A LOW LEVEL THERMAL RIDGE WILL EXTEND INTO THE CWA FROM
THE SOUTHWEST...PROMOTING WHAT SHOULD BE THE HIGHEST HEAT-INDEX
READINGS OF THE SUMMER SO FAR FOR MOST ALL OF THE CWA...AND IN
SOME SPOTS THE HOTTEST ACTUAL AIR TEMPERATURES. THE ONLY CAVEATS
WOULD BE AN UNEXPECTEDLY STRONG OUTFLOW BOUNDARY FROM CONVECTION
TONIGHT THAT MIGHT HELP ACCELERATE THE COLD FRONT SOUTHWARD
FASTER...AND MAYBE A DENSER-THAN-EXPECTED COVERAGE OF MID LEVEL
CLOUDS OR LINGERING WEAK CONVECTION. BUT ASSUMING NEITHER ONE OF
THESE CAVEATS PLAY OUT...HAVE AIMED FOR ACTUAL HIGH TEMPS RANGING
FROM MID 90S NORTH...UPPER 90S CENTRAL...AND 100-106 NEAR AND
SOUTH OF THE STATE LINE. HEAT INDEX VALUES OF 100+ ARE FORECAST
ACROSS MUCH OF THE SOUTHERN AND EASTERN HALVES OF THE CWA...AND
HAVE ISSUED A HEAT ADVISORY FOR ALL KS ZONES ALONG WITH WEBSTER-
NUCKOLLS-THAYER IN NEBRASKA...WHICH HAVE THE HIGHEST LIKELIHOOD OF
REACHING OR EXCEEDING A 105 HEAT INDEX. FORTUNATELY FOR FIRE
WEATHER CONCERNS IN THE FAR SOUTHWEST COUNTIES...SUSTAINED
WINDS/GUSTS DO NOT LOOK TO EXCEED 20 MPH DURING THE PEAK OF
AFTERNOON HEATING. AS FOR CONVECTIVE CHANCES...FORECAST SOUNDINGS
SUGGEST THAT A FAIRLY STRONG CAP SHOULD PREVAIL THROUGH THE DAY AS
VERY WARM MID LEVEL TEMPS OVERSPREAD THE AREA. AS A RESULT...OTHER
THAN A LINGERING SLIGHT CHANCE OF MORNING STORMS IN EASTERN
COUNTIES RIGHT AWAY IN THE MORNING...WILL AIM FOR A DRY MAJORITY
OF THE DAY...BEFORE BRINGING BACK SLIGHT STORM CHANCES POST-
21Z/4PM. THERE ARE AT LEAST TWO POSSIBLE FOCUSES FOR LATE
AFTERNOON DEVELOPMENT...THE MAIN COLD FRONT WHICH SHOULD BE VERY
NEAR THE FAR SOUTHEAST CORNER OF THE CWA...AND ALSO FORCING FROM
THE SOUTHERN EDGE OF THE NORTHERN PLAINS SHORTWAVE TROUGH...WHICH
COULD KICK OFF CONVECTION CLOSER TO THE NORTHERN EDGE OF THE CWA.
HOWEVER...MODELS SUCH AS THE 12Z 4KM WRF-NMM ADVERTISE ESSENTIALLY
NO LATE AFTERNOON STORMS ANYWHERE IN THE CWA...SO THUS ONLY THE
SLIGHT POPS. IF STORMS WOULD MANAGE TO FORM...A CONDITIONAL SEVERE
THREAT COULD EXIST ALMOST ANYWHERE IN THE CWA...POTENTIALLY EVEN
WEST OF THE SPC DAY 2 SLIGHT RISK AREA. PLENTY OF UNCERTAINTY FOR
SURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
MAIN FORECAST CONCERNS
WILL BE CHANCES FOR THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY NIGHT
AND AGAIN SATURDAY NIGHT THROUGH MONDAY AND TEMPERATURES.
MODELS ARE FAIRLY SIMILAR IN BUILDING AN UPPER LEVEL RIDGE ACROSS
THE AREA DURING THE PERIOD...BUT THE DETAILS OF THE TIMING MAINLY
WEAK UPPER LEVEL WAVES THROUGH THE AREA ARE SOMEWHAT DIFFERENT
BETWEEN THE MODELS. THIS BRINGS SOME UNCERTAINTY IN WHEN THERE WILL
BE SOME CHANCES FOR THUNDERSTORMS.
A SURFACE COLD FRONT WILL MOVE TO THE SOUTH ACROSS THE SOUTHERN PART
OF THE FORECAST AREA DURING THE EVENING. AN UPPER LEVEL WAVE WILL
ALSO BE MOVING THROUGH THE AREA. EXPECT SOME THUNDERSTORMS ALONG
THAT BOUNDARY DURING THE EVENING...BUT OVERNIGHT THEY SHOULD MOVE
OUT OF THE AREA. MUCAPE IS THE HIGHEST DURING THE EARLY EVENING
HOURS AND DIMINISHES SOME LATER IN THE EVENING...BUT STILL REMAINS
AROUND 2500 J/KG. EXPECT THAT THERE COULD BE SOME SEVERE WEATHER
DURING THE EVENING.
A COOL SURFACE HIGH PRESSURE SYSTEM SETTLES INTO THE AREA ON
WEDNESDAY. HIGH TEMPERATURES WILL BE AROUND 10 DEGREES COOLER THAN
ON TUESDAY. WEDNESDAY SHOULD REMAIN DRY...BUT AN UPPER LEVEL WAVE
MOVES ACROSS THE RIDGE AND THERE COULD BE SOME ISOLATED SHOWERS AND
THUNDERSTORMS THAT MOVE OFF THE HIGH PLAINS DURING THE NIGHT TIME
HOURS.
THE SURFACE HIGH MOVES OFF TO THE EAST ON THURSDAY AND THE SURFACE
PRESSURE GRADIENT TIGHTENS. WINDS AT 850MB ARE ONLY 20 TO 25 KTS SO
EXPECT SOME BREEZY CONDITIONS. WITH WINDS FROM THE SOUTH THE
TEMPERATURES WILL WARM UP.
THE UPPER LEVEL RIDGE CONTINUES TO BUILD ACROSS THE AREA FOR THE
PERIOD THURSDAY THROUGH SATURDAY. EXPECT TEMPERATURES TO WARM A
LITTLE EACH DAY THROUGH THE PERIOD.
THE UPPER LEVEL RIDGE REMAINS IN PLACE FOR SATURDAY NIGHT THROUGH
MONDAY...BUT IT IS MORE OF AN UPPER LEVEL HIGH PRESSURE SYSTEM
ACROSS THE AREA. IT IS FAIRLY BROAD AND THERE ARE A FEW UPPER LEVEL
WAVES THAT MOVE THROUGH THE AREA. SIMILAR TO THE PAST WEEK OR SO
EACH OF THESE UPPER LEVEL WAVES HAS A CHANCE FOR SOME THUNDERSTORMS.
DO NOT EXPECT THAT IT WILL BE WIDESPREAD OR THAT EVERYONE WILL HAVE
SOME PRECIPITATION. THE TIMING AND THE LOCATION OF ANY PRECIPITATION
IS IN QUESTION. WITH A FEW MORE CLOUDS AND THE CHANCE FOR SOME
PRECIPITATION THE TEMPERATURES WILL BE A LITTLE COOLER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 625 PM CDT MON JUL 8 2013
PRIMARY CONCERNS FOR THIS TAF PERIOD LIE WITH PRECIPITATION
CHANCES THIS EVENING/OVERNIGHT...THEN THE PASSAGE OF A COLD
FRONTAL BOUNDARY TOMORROW. HAVE ALREADY SEEN A CLUSTER OF
SHOWERS/THUNDERSTORMS DEVELOP OFF TO THE SOUTHWEST OF THE TERMINAL
AREA...BUT CONFIDENCE IN THAT ACTIVITY DRIFTING UP TO AFFECT THE
TERMINAL IS NOT HIGH ENOUGH TO INSERT ANY TEMPO GROUP OR
PREVAILING MENTION...BUT WILL BE KEEPING A CLOSE EYE ON IT. STILL
SEEING THE POTENTIAL FOR ACTIVITY FROM THE WEST TO SLIDE EAST
ACROSS THE REGION LATER ON...AND WILL KEEP THE VCTS MENTION GOING.
WINDS LOOK TO BECOME MORE SOUTHERLY WITH TIME THIS EVENING...AND
WILL REMAIN THAT WAY UNTIL CLOSER TO MIDDAY TOMORROW...WHEN WINDS
GRADUALLY BECOME MORE WESTERLY AHEAD OF AN APPROACHING FRONT.
MODELS NOT IN TOO BAD OF AGREEMENT WITH THE TIMING ARND 18Z...WITH
NORTHWEST WINDS BUILDING IN BEHIND THROUGH THE REMAINDER OF THE
TAF PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT TUESDAY FOR NEZ085>087.
KS...HEAT ADVISORY FROM NOON TO 7 PM CDT TUESDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...JCB
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1258 PM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT SUN JUL 7 2013
IF MOISTURE CAN REMAIN IN PLACE THIS MORNING THEN ANOTHER ROUND OF
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON AND TONIGHT. THE
DISTURBANCE AND ONGOING STORM ACTIVITY ACROSS WESTERN NEB SHOULD
EXIT THE FCST AREA TO EAST BY 20Z. THIS IMPLIES THAT THE STORMS
WEAKEN AND FALL APART AS THEY MOVE EAST AS INDICATED BY THE HRRR.
DEEP EASTERLIES SHOULD CONTINUE TODAY AS INDICATED BY THE VWP AT
KUDX AND THIS WOULD SUPPORT DESTABILIZATION ACROSS WESTERN NEB LATE
THIS MORNING THROUGH THIS EVENING WHICH IN TURN WOULD PROPAGATE EAST
THROUGH THE FCST AREA. THE FCST MIGHT BE AMBITIOUS WITH THE 40 POPS
BUT THIS IS A MARK DOWN FROM A 5 MODEL BLEND OF THE
ECM...GFS...SREF...NAM AND GEMREG. WATER VAPOR SUGGESTS ANOTHER
DISTURBANCE ACROSS WRN WY AND NRN UT WHICH COULD COME ACROSS THIS
AFTERNOON ON THE HEALS OF THE ONGOING DISTURBANCE.
MODEST DEEP LAYER SHEAR UP TO 250 MB WOULD PERHAPS SUPPORT ISOLATED
SEVERE STORMS WHICH WOULD PROBABLY PULSE SEVERE FROM TIME TO TIME
THIS AFTERNOON AND THIS EVENING. THE WEAKNESS IN THE LOW LEVEL WINDS
SUGGESTS THIS BEHAVIOR. SPC SUGGESTED A WEAKLY ORGANIZED MCS MIGHT
DEVELOP AND THIS CERTAINLY APPEARS IN LINE WITH THE 21Z OUTPUT OF
THE 06Z HRRR SHOWING A FAIRLY ORGANIZED LINE OF STORMS FROM KOGA TO
KVTN.
HIGHS IN THE UPPER 80S TO MID 90S ARE EXPECTED TODAY. THE MODELS
HAVE COME IN A FEW DEGREES COOLER FOR HIGHS TODAY VERSUS SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 311 AM CDT SUN JUL 7 2013
ACTIVE FIRST HALF OF THE WEEK EXPECTED...AS THE AREA REMAINS ON
THE NORTHERN SIDE OF LARGE RIDGE OF UPPER HIGH PRESSURE CENTERED
ACROSS THE FOUR CORNERS REGION. WINDS ALOFT...MOISTURE...AND
INSTABILITY WILL BE FAVORABLE FOR TSTMS UNTIL THE RIDGE BEGINS TO
BUILD NORTH OVER THE AREA BY WEEKS END. TEMPERATURES ALOFT WILL
WARM THEN AS WELL AS A DECREASE IN WINDS ALOFT...CONDITIONS LESS
FAVORABLE FOR TSTM DEVELOPMENT.
A STATIONARY FRONT WILL OSCILLATE NORTH AND SOUTH THE FIRST HALF
OF THE WEEK...AND WILL BE A FOCUS FOR STORM DEVELOPMENT. OTHER
STORMS MAY FORM OFF THE HIGHER TERRAIN TO OUR WEST AND MOVE EAST
INTO THE AREA DURING THE EVENING HOURS. PWATS WILL BE RATHER
HIGH...WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE TOO...SO SOME
DECENT RAINFALL TOTALS ARE POSSIBLE.
TEMPERATURES WILL BE WARM...AND THEN TURNING HOT BY WEEKS END AS
THE RIDGE BUILDS NORTH OVER THE AREA. HIGHS IN THE UPPER 80S TO
MID 90S WILL START THE WEEK...WITH MID 90S TO AROUND 100 TO FINISH
THE WEEK. DEPENDING ON DEW POINTS...WHICH CURRENTLY LOOK TO REMAIN
HIGH EAST OF HIGHWAY 83 AS THE HEAT BUILDS IN BY THE END OF THE
WEEK...WE COULD BE FLIRTING WITH HEAT ADVISORY CONDITIONS. WILL
CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1257 PM CDT SUN JUL 7 2013
SMALL AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS CONTINUES
TO MOVE ACROSS NORTHERN NEBRASKA. A BRIEF IMPACT FOR KVTN...WITH
MVFR CONDITIONS...OTHERWISE THE AREA WILL SHIFT EAST AND EXIT
OVER THE NEXT FEW HOURS. MEANWHILE MORE MOISTURE...COMPARED TO
RECENT DAYS...WILL HELP TO ALLOW DEVELOPMENT OF THUNDERSTORMS
ACROSS THE WEST THIS AFTERNOON...WHICH WILL PROPAGATE EASTWARD
THIS EVENING. HAVE INCLUDED THUNDERSTORMS IN BOTH THE KLBF AND
KVTN TAF...HOWEVER HIGHER CONFIDENCE IS FOR KVTN. ALL ACTIVITY
WILL PUSH EAST OF THE TERMINALS OVERNIGHT...AS THE UPPER LEVEL
WAVE PUSHES EAST...RESULTING IN DECREASING CLOUDS AND LIGHT
WINDS...UNDER 10 KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
623 AM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT SUN JUL 7 2013
IF MOISTURE CAN REMAIN IN PLACE THIS MORNING THEN ANOTHER ROUND OF
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON AND TONIGHT. THE
DISTURBANCE AND ONGOING STORM ACTIVITY ACROSS WESTERN NEB SHOULD
EXIT THE FCST AREA TO EAST BY 20Z. THIS IMPLIES THAT THE STORMS
WEAKEN AND FALL APART AS THEY MOVE EAST AS INDICATED BY THE HRRR.
DEEP EASTERLIES SHOULD CONTINUE TODAY AS INDICATED BY THE VWP AT
KUDX AND THIS WOULD SUPPORT DESTABILIZATION ACROSS WESTERN NEB LATE
THIS MORNING THROUGH THIS EVENING WHICH IN TURN WOULD PROPAGATE EAST
THROUGH THE FCST AREA. THE FCST MIGHT BE AMBITIOUS WITH THE 40 POPS
BUT THIS IS A MARK DOWN FROM A 5 MODEL BLEND OF THE
ECM...GFS...SREF...NAM AND GEMREG. WATER VAPOR SUGGESTS ANOTHER
DISTURBANCE ACROSS WRN WY AND NRN UT WHICH COULD COME ACROSS THIS
AFTERNOON ON THE HEALS OF THE ONGOING DISTURBANCE.
MODEST DEEP LAYER SHEAR UP TO 250 MB WOULD PERHAPS SUPPORT ISOLATED
SEVERE STORMS WHICH WOULD PROBABLY PULSE SEVERE FROM TIME TO TIME
THIS AFTERNOON AND THIS EVENING. THE WEAKNESS IN THE LOW LEVEL WINDS
SUGGESTS THIS BEHAVIOR. SPC SUGGESTED A WEAKLY ORGANIZED MCS MIGHT
DEVELOP AND THIS CERTAINLY APPEARS IN LINE WITH THE 21Z OUTPUT OF
THE 06Z HRRR SHOWING A FAIRLY ORGANIZED LINE OF STORMS FROM KOGA TO
KVTN.
HIGHS IN THE UPPER 80S TO MID 90S ARE EXPECTED TODAY. THE MODELS
HAVE COME IN A FEW DEGREES COOLER FOR HIGHS TODAY VERSUS SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 311 AM CDT SUN JUL 7 2013
ACTIVE FIRST HALF OF THE WEEK EXPECTED...AS THE AREA REMAINS ON
THE NORTHERN SIDE OF LARGE RIDGE OF UPPER HIGH PRESSURE CENTERED
ACROSS THE FOUR CORNERS REGION. WINDS ALOFT...MOISTURE...AND
INSTABILITY WILL BE FAVORABLE FOR TSTMS UNTIL THE RIDGE BEGINS TO
BUILD NORTH OVER THE AREA BY WEEKS END. TEMPERATURES ALOFT WILL
WARM THEN AS WELL AS A DECREASE IN WINDS ALOFT...CONDITIONS LESS
FAVORABLE FOR TSTM DEVELOPMENT.
A STATIONARY FRONT WILL OSCILLATE NORTH AND SOUTH THE FIRST HALF
OF THE WEEK...AND WILL BE A FOCUS FOR STORM DEVELOPMENT. OTHER
STORMS MAY FORM OFF THE HIGHER TERRAIN TO OUR WEST AND MOVE EAST
INTO THE AREA DURING THE EVENING HOURS. PWATS WILL BE RATHER
HIGH...WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE TOO...SO SOME
DECENT RAINFALL TOTALS ARE POSSIBLE.
TEMPERATURES WILL BE WARM...AND THEN TURNING HOT BY WEEKS END AS
THE RIDGE BUILDS NORTH OVER THE AREA. HIGHS IN THE UPPER 80S TO
MID 90S WILL START THE WEEK...WITH MID 90S TO AROUND 100 TO FINISH
THE WEEK. DEPENDING ON DEW POINTS...WHICH CURRENTLY LOOK TO REMAIN
HIGH EAST OF HIGHWAY 83 AS THE HEAT BUILDS IN BY THE END OF THE
WEEK...WE COULD BE FLIRTING WITH HEAT ADVISORY CONDITIONS. WILL
CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 620 AM CDT SUN JUL 7 2013
VFR IS EXPECTED THROUGH 18Z MOST AREAS. THEREAFTER...THE MODEL
CONSENSUS SUGGESTS SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS AN
INCREASINGLY LARGER PORTION OF THE FCST AREA AND SPREAD EAST
THROUGH SUNDAY NIGHT.
STORM ACTIVITY ACROSS NORTHWEST NEBRASKA SHOULD CONTINUE THIS
MORNING WITH VFR ELSEWHERE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
332 AM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT SUN JUL 7 2013
IF MOISTURE CAN REMAIN IN PLACE THIS MORNING THEN ANOTHER ROUND OF
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON AND TONIGHT. THE
DISTURBANCE AND ONGOING STORM ACTIVITY ACROSS WESTERN NEB SHOULD
EXIT THE FCST AREA TO EAST BY 20Z. THIS IMPLIES THAT THE STORMS
WEAKEN AND FALL APART AS THEY MOVE EAST AS INDICATED BY THE HRRR.
DEEP EASTERLIES SHOULD CONTINUE TODAY AS INDICATED BY THE VWP AT
KUDX AND THIS WOULD SUPPORT DESTABILIZATION ACROSS WESTERN NEB LATE
THIS MORNING THROUGH THIS EVENING WHICH IN TURN WOULD PROPAGATE EAST
THROUGH THE FCST AREA. THE FCST MIGHT BE AMBITIOUS WITH THE 40 POPS
BUT THIS IS A MARK DOWN FROM A 5 MODEL BLEND OF THE
ECM...GFS...SREF...NAM AND GEMREG. WATER VAPOR SUGGESTS ANOTHER
DISTURBANCE ACROSS WRN WY AND NRN UT WHICH COULD COME ACROSS THIS
AFTERNOON ON THE HEALS OF THE ONGOING DISTURBANCE.
MODEST DEEP LAYER SHEAR UP TO 250 MB WOULD PERHAPS SUPPORT ISOLATED
SEVERE STORMS WHICH WOULD PROBABLY PULSE SEVERE FROM TIME TO TIME
THIS AFTERNOON AND THIS EVENING. THE WEAKNESS IN THE LOW LEVEL WINDS
SUGGESTS THIS BEHAVIOR. SPC SUGGESTED A WEAKLY ORGANIZED MCS MIGHT
DEVELOP AND THIS CERTAINLY APPEARS IN LINE WITH THE 21Z OUTPUT OF
THE 06Z HRRR SHOWING A FAIRLY ORGANIZED LINE OF STORMS FROM KOGA TO
KVTN.
HIGHS IN THE UPPER 80S TO MID 90S ARE EXPECTED TODAY. THE MODELS
HAVE COME IN A FEW DEGREES COOLER FOR HIGHS TODAY VERSUS SATURDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 311 AM CDT SUN JUL 7 2013
ACTIVE FIRST HALF OF THE WEEK EXPECTED...AS THE AREA REMAINS ON
THE NORTHERN SIDE OF LARGE RIDGE OF UPPER HIGH PRESSURE CENTERED
ACROSS THE FOUR CORNERS REGION. WINDS ALOFT...MOISTURE...AND
INSTABILITY WILL BE FAVORABLE FOR TSTMS UNTIL THE RIDGE BEGINS TO
BUILD NORTH OVER THE AREA BY WEEKS END. TEMPERATURES ALOFT WILL
WARM THEN AS WELL AS A DECREASE IN WINDS ALOFT...CONDITIONS LESS
FAVORABLE FOR TSTM DEVELOPMENT.
A STATIONARY FRONT WILL OSCILLATE NORTH AND SOUTH THE FIRST HALF
OF THE WEEK...AND WILL BE A FOCUS FOR STORM DEVELOPMENT. OTHER
STORMS MAY FORM OFF THE HIGHER TERRAIN TO OUR WEST AND MOVE EAST
INTO THE AREA DURING THE EVENING HOURS. PWATS WILL BE RATHER
HIGH...WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE TOO...SO SOME
DECENT RAINFALL TOTALS ARE POSSIBLE.
TEMPERATURES WILL BE WARM...AND THEN TURNING HOT BY WEEKS END AS
THE RIDGE BUILDS NORTH OVER THE AREA. HIGHS IN THE UPPER 80S TO
MID 90S WILL START THE WEEK...WITH MID 90S TO AROUND 100 TO FINISH
THE WEEK. DEPENDING ON DEW POINTS...WHICH CURRENTLY LOOK TO REMAIN
HIGH EAST OF HIGHWAY 83 AS THE HEAT BUILDS IN BY THE END OF THE
WEEK...WE COULD BE FLIRTING WITH HEAT ADVISORY CONDITIONS. WILL
CONTINUE TO MONITOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1226 AM CDT SUN JUL 7 2013
CLUSTER OF TSRA MOVING INTO PORTIONS OF NORTH CENTRAL NEBRASKA
CONTINUE TO MOVE EAST AND SEEM TO BE MAINTAINING STRENGTH...UNLIKE
TSRA EARLIER IN THE EVENING AS THEY ENCOUNTERED LESS FAVORABLE MID
LEVEL INSTABILITY. INSTABILITY MAY BE SLIGHTLY BETTER NOW BASED ON
MESOANALYSIS OF MID LEVEL LAPSE RATES. AT THIS TIME HAVE MENTIONED
VCTS FOR KVTN AFTER 08Z ASSUMING THEY HOLD TOGETHER.
OTHERWISE VFR CONDITIONS FOR THE PERIOD...HOWEVER TSRA CHANCES
INCREASE AGAIN SUNDAY AFTER ABOUT 20Z WITH A BOUNDARY IN PLACE
ACROSS THE SOUTHERN PORTION OF THE FCST AREA. INCREASING LOW LEVEL
MOISTURE NORTH OF THE BOUNDARY LEADING TO A BETTER SHEAR/CAPE
BALANCE SHOULD ALLOW BETTER COVERAGE OF STORMS TO AFFECT TAF SITES
DURING THE FAVORED DIURNAL PERIOD FOR TSRA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1145 PM CDT SAT JUL 6 2013
.DISCUSSION...
PROBABLY NOT MUCH OF A CHANCE OF ANY PRECIPITATION OVERNIGHT AS
WHATEVER REMAINS OF A WEAK UPPER LEVEL DISTURBANCE THAT WAS MOVING
THROUGH CENTRAL NEBRASKA CONTINUES TO WASH OUT OVERNIGHT AS THE
SURFACE FRONT REMAINS TO OUR WEST.
&&
.AVIATION...06Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
THROUGH THE PERIOD WITH SOUTHEAST WINDS LESS THAN 10 KNOTS
GENERALLY...WITH WINDS BECOMING SOUTHWEST BY 15Z. A FRONTAL
BOUNDARY WILL BE MOVING INTO THE AREA SUNDAY MORNING...WHICH
SHOULD BRING A SURFACE WIND SHIFT TO THE NORTHEAST AT KOFK BY 15Z.
DEWALD
PREV DISCUSSION... /ISSUED 331 PM CDT SAT JUL 6 2013/
DISCUSSION...
OFF-AND-ON THUNDERSTORM CHANCES OVER THE NEXT SEVERAL DAYS ARE THE
MAIN FORECAST CONCERNS.
MORNING UPPER AIR CHARTS SHOWED HIGH PRESSURE IN THE SOUTHWEST
STATES AND OFF THE ATLANTIC COAST WITH A WEAK LOW IN THE MIDDLE
MOVING INTO THE OHIO VALLEY REGION. FAST WESTERLY FLOW COVERED THE
NORTHERN TIER OF THE CONUS. OUR AREA REMAINED IN THE TRANSITION ZONE
OF HIGHER HEIGHTS TO THE SOUTH AND FAST FLOW TO THE NORTH. AT THE
SURFACE...A WIND SHIFT LINE WAS NOTED IN CENTRAL SOUTH DAKOTA AND
WESTERN NEBRASKA...TIED TO A SHORTWAVE EXTENDING FROM THE NORTHERN
PLAINS INTO NEBRASKA. AND A COLD FRONT WAS PUSHING INTO THE WESTERN
DAKOTAS.
LIGHT SHOWERS OR SPRINKLES THAT MOVED ACROSS EASTERN NEBRASKA THIS
MORNING HAVE LEFT OUR AREA CAPPED TO CONVECTION SO FAR THIS
AFTERNOON. RAP SOUNDINGS SUGGEST SURFACE-BASED CAPES WERE TOPPING
1000 J/KG...BUT INHIBITION WAS STILL ROBUST. BUT WITH TEMPERATURES
WARMING A FEW MORE DEGREES LATE IN THE DAY...COULD SEE AN ISOLATED
SHOWER OR STORM POP UP THIS EVENING...PROBABLY IN WESTERN IOWA. THEN
LATER TONIGHT...WIND SHIFT LINE WILL SETTLE SOUTHEAST INTO OUR AREA
AS SHORTWAVE MOVES OFF TO THE EAST. INSTABILITY WAS STRONG IN
CENTRAL/WESTERN SOUTH DAKOTA NEAR/AHEAD OF WIND SHIFT...SO AM
EXPECTING STORMS TO FIRE THERE LATE THIS AFTERNOON OR EVENING. THIS
ACTIVITY SHOULD PUSH OFF TO THE EAST BUT COULD SKIRT OUR NORTHERN
CWA. OTHERWISE MORE GENERAL THUNDER CHANCES ARE POSSIBLE WITH WIND
SHIFT LINE AS IT MOVES INTO EASTERN NEBRASKA AFTER MIDNIGHT.
SURFACE BOUNDARY WILL REMAIN IN OUR AREA DURING THE DAY SUNDAY. NOT
MUCH NOTED IN MID LEVEL FLOW TO KICK UP CONVECTION ALONG THE
FRONT...SO WILL HAVE TO WAIT UNTIL LATE AFTERNOON WHEN INSTABILITY
IS MAXIMIZED. THEN FRONT/WIND SHIFT SHOULD BE OVER NORTHEAST
NEBRASKA...SO HAVE MAINTAINED A SMALL CHANCE FOR THUNDERSTORMS
THERE. BETTER CHANCES FOR STORMS WILL COME SUNDAY NIGHT INTO MONDAY
AS ANOTHER SHORTWAVE MOVES INTO THE PLAINS. MEANWHILE FRONTAL
BOUNDARY WILL SETTLE SOUTH SUNDAY NIGHT...THE LIFT BACK NORTH ON
MONDAY. COMBINATION OF TEMPERATURES CLIMBING INTO THE 90S AND
COOLING TEMPERATURES ALOFT WITH SHORTWAVE WILL PRODUCE CAPES
APPROACHING 3000 J/KG WITH 30KT OF 0-6KM BULK SHEAR MONDAY
AFTERNOON. SO WILL CONTINUE OUR SMALL CHANCES FOR STORMS SUNDAY
NIGHT AS BOUNDARY SETTLES SOUTH...AND HIGHER CHANCES MONDAY
AFTERNOON IN THE NORTH WHERE BOUNDARY/INSTABILITY WILL BE MAXIMIZED.
SOME SEVERE STORMS ARE POSSIBLE GIVEN INSTABILITY/SHEAR.
STORMS CHANCES SHOULD CONTINUE MONDAY NIGHT INTO TUESDAY AS FRONTAL
BOUNDARY REMAINS IN OUR AREA...REINFORCED BEHIND EXITING SHORTWAVE.
INSTABILITY WILL AGAIN APPROACH 3000 J/KG ALONG BOUNDARY TUESDAY
AFTERNOON...WITH A TAD GREATER SHEAR. SO AGAIN SEVERE IS POSSIBLE
TUESDAY AFTERNOON.
FRONT IS FORECAST TO SETTLE SOUTH OF OUR AREA ON WEDNESDAY...SO WILL
KEEP WEDNESDAY AND THURSDAY DRY. UPPER RIDGE BEGINS TO BUILD INTO
OUR AREA FRIDAY AND SATURDAY SIGNALING A RETURN TO WARMER
TEMPERATURES. AS RIDGE BUILDS...WARM ADVECTION REGIME ON FRIDAY
COULD SPARK STORMS...BUT DRY AFTER THAT AS MID LEVEL TEMPS WARM.
TEMPERATURES INTO MONDAY AND TUESDAY WILL EASILY REACH THE 90S...BUT
COULD HOLD IN THE 80S WHERE STORMS/CLOUDS LINGER. A LITTLE COOLER
WEDNESDAY AND THURSDAY WITH HIGHS IN THE 80S...BUT A RETURN TO 90S
LOOK LIKELY FRIDAY AND SATURDAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
435 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WARM AND HUMID AIRMASS WILL PERSIST ACROSS THE REGION THROUGH MUCH
OF THE WEEK WITH NEAR DAILY CHANCES OF SHOWERS AND THUNDERSTORMS
EXPECTED. THE HIGHEST CONCENTRATION OF SHOWERS AND STORMS WILL OCCUR
ON MONDAY AND AGAIN ON WEDNESDAY WHEN LOCALLY HEAVY RAINFALL IS
POSSIBLE. TEMPERATURES WILL REMAIN ON THE WARM SIDE...WITH HIGHS IN
THE 80S AND OVERNIGHT LOWS GENERALLY IN THE 60S.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 435 PM EDT SUNDAY...A WARM AND HUMID NIGHT EXPECTED ACROSS
THE AREA AS DEEPER SUBTROPICAL FLOW HAS PUSHED BACK NORTH AND EAST
INTO THE AREA AS EXPECTED. SCATTERED SHOWERS ALSO EXPECTED ON AND
OFF THROUGH THE EVENING AND NIGHTTIME HOURS AS HI-RES MODELS AND
THIS AFTERNOON`S RAP ANALYSIS SHOWING A WEAK SHORTWAVE MOVING
THROUGH THE FLOW ACROSS OUR AREA. MID-LEVEL MOISTURE CONVERGENCE
ALSO EVIDENT AS WEAK SURFACE FRONT SAGS SOUTH TO NEAR THE INTL
BORDER OVERNIGHT AND STALLS. WITH SUCH WEAK FEATURES QUITE
DIFFICULT TO TIME AREAL PLACEMENT AND INTENSITY OF PCPN...BUT PER
LATEST LAPS/RUC PROGS WILL ADVERTISE HIGH CHANCE POPS AND CONFINE
HIGHER THREAT OF THUNDER AND LOCALLY HEAVY RAINFALL TO OUR
SOUTHERN COUNTIES WHERE BEST MLCAPE PROFILES EXIST. AGAIN...A
MUGGY NIGHT EXPECTED AS SURFACE DEWPOINTS HOLD IN THE 60S TO
AROUND 70. WINDS LIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 435 PM EDT SUNDAY...BY MONDAY STILL LOOKING AT SCATTERED TO
WIDESPREAD SHOWERS AND THUNDER ACROSS MUCH OF THE AREA WITH WARM
AND MOIST AIRMASS IN PLACE ON THE WESTERN PERIPHERY OF STRONG
BERMUDA HIGH PRESSURE. WE`LL ALSO HAVE SOME ADDED IMPETUS FROM A
WEAKENING MID-LEVEL SHORTWAVE TROUGH LIFTING OUT OF THE LOWER
GREAT LAKES/OHIO VALLEY STATES THROUGH THE DAY. THIS COMBINED WITH
LIGHTLY VEERED PBL FLOW...LOWER NCAPE AND DEEP WCD VALUES IN
EXCESS OF 11 KFT ALL SUPPORT CONTINUED MENTION OF LOCALLY HEAVY
RAINFALL IN THE MORE ROBUST CELLS WHERE EFFICIENT PRECIPITATION
LOADING WILL BE LIKELY. WHILE I CAN`T COMPLETELY RULE OUT AN
ISOLATED SEVERE CELL...WITH SUCH HIGH WBZ VALUES I`M REALLY NOT
EXPECTING ANYTHING OTHER THAN SOME BRIEF GUSTY WINDS AND POSSIBLE
SMALL HAIL IN THE STRONGER CORES. HIGHS ON THE SEASONABLY WARM
SIDE...76 TO 84 OR CLOSE TO BLENDED BIAS-CORRECTED GUIDANCE.
EVENING SHOWERS AND STORMS THEN SLOWLY WANE IN AREAL COVERAGE AND
INTENSITY AS WE PROGRESS INTO MONDAY NIGHT AS SHORTWAVE EXITS EAST
AND WEAK RIDGING ALONG WITH LAYER OF DRIER MID-LEVEL AIR ADVECTS
INTO THE REGION. NO AIRMASS CHANGE...BUT ENOUGH DRYING SUCH THAT
MANY AREAS SHOULD TREND DRY BY TUESDAY MORNING. LOWS MAINLY IN THE
60S.
THEN MORE UNCERTAINTY AS WE HEAD INTO TUESDAY. FEELING IS TUESDAY
SHOULD BE MORE DRY THAN WET GIVEN MID-LEVEL DRY AIR AND WEAK
SUBSIDENCE ADVECTING ACROSS THE REGION...BUT EVIDENCE THAT SOME SORT
OF LOWER LEVEL MOISTURE BOUNDARY MAY LINGER ACROSS OUR EASTERN
COUNTIES. ECMWF MORE ROBUST WITH CHANCES PCPN THAN OTHER SHORT TERM
MODELS...BUT WILL DOWNPLAY AT THIS POINT OFFERING JUST SLIGHT TO
LOWER CHANCE POPS THROUGH THE DAY AND MAINLY ACROSS VT WHERE SOME
WIDELY SCATTERED ACTIVITY MAY OCCUR. HIGHS IN THE LOWER TO MID 80S.
BY TUESDAY NIGHT WARM AND HUMID CONDITIONS CONTINUE BUT MAINLY DRY
WITH LOSS OF INSOLATION. LOWS TO HOLD ON THE MILD SIDE AND MAINLY IN
THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...ACTIVE WEATHER DAY EXPECTED WEDS/THURS
AS POTENT TROF DEVELOPS ACRS THE NORTHERN GREAT LAKES AND SFC COLD
FRNT MOVES ACRS OUR CWA. THIS FRNT WL INTERACT WITH MODEST INSTABILITY
WITH LIS AROUND -4C AND CAPE VALUES BTWN 1500 TO 2000 J/KG.
ALSO...NOTED A RIBBON OF ENHANCED MID LVL WINDS...CREATING DEEP
LAYER SHEAR VALUES BTWN 30 AND 40 KNOTS...ESPECIALLY ACRS OUR
NORTHERN CWA ON WEDS AFTN. THE AREAL COVERAGE/INTENSITY OF STORMS
WL HIGHLY DEPEND UPON AMOUNT OF INSTABILITY/CLRING AND EXACT TRACK OF S/W
ENERGY. GIVEN...THE GOOD AGREEMENT IN MODELS WITH SYNOPTIC
FEATURES WL CONT TO MENTION HIGH CHC/LOW LIKELY POPS WEDS INTO
WEDS NIGHT...STILL A MINOR TIMING DIFFERENCE BTWN THE FASTER GFS
AND SLOWER ECMWF. WEAK SUBSIDENCE AND HIGH PRES TRIES TO BUILD
ACRS OUR CWA LATE THURS INTO FRIDAY...WITH A BRIEF DRY SPELL
POSSIBLE. LOTS OF UNCERTAINTY ASSOCIATED WITH NEXT SYSTEM FRIDAY
INTO NEXT WEEKEND...WITH GFS SHOWING MID/UPPER CLOSED CIRCULATION
ACRS THE GREAT LAKES RETROGRADING SW TWD TEXAS BY SUNDAY...WHILE
THE ECMWF SPLITS THE SYSTEM INTO TWO DISTINCT CLOSED CIRCULATIONS
WITH GREATER IMPACT ACRS OUR FA. GIVEN THE UNCERTAINTY IN THE
EVOLUTION OF THIS COMPLEX SYNOPTIC PATTERN...WL MENTION CHC POPS
NEXT WEEKEND. IF THE ULVL PATTERN VERIFIES ON THE ECMWF AND DEEP
TROPICAL MOISTURE IS ADVECTED BACK INTO THE NE CONUS...HYDRO WL
NEED TO BE WATCHED CLOSELY...FOR THE POTENTIAL FOR HEAVY RAINFALL.
PROGGED 85H TEMPS AHEAD OF BOUNDARY RANGE BTWN 14-16C ON
WEDS/THURS...BEFORE COOLING BACK BTWN 10-12C ON
FRIDAY...SUPPORTING HIGHS MID/UPPER 80S MID WEEK TO M70S TO L80S
BY NEXT FRIDAY. LOWS WL BE MAINLY IN THE U50S MTNS TO M60S
VALLEYS.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...CRNT RADAR SHOWS RAIN SHOWERS INCREASING IN
AREAL COVERAGE/INTENSITY ACRS NORTHERN NY AND INTO THE WESTERN CPV
ATTM. EXPECT THIS ACTIVITY TO IMPACT OUR TAF SITES BTWN 18Z-22Z
THIS AFTN WITH A BRIEF SHOWER AND POSSIBLE MVFR CONDITIONS IN THE
HEAVIER SHOWER. THE POTENTIAL FOR ADDITIONAL SHOWERS WITH AN
EMBEDDED STORM WL CONT OVERNIGHT INTO MONDAY...AS SEVERAL EMBEDDED
S/W`S INTERACT WITH SFC INSTABILITY. DIFFICULT TO PIN POINT EXACT
TIMING AND LOCATION OF STORMS...THEREFORE USED VCSH THRU MOST OF
THE NIGHT. ALSO...GIVEN THE INCREASED SFC DWPTS AND BL
MOISTURE...AREAS OF HZ/BR WL BE POSSIBLE ESPECIALLY AT SITES THAT
RECIEVE RAIN THIS AFTN AND AT KMSS. SOUTH TO SOUTHWEST WINDS AT 4
TO 8 KNOTS THIS AFTN...WL BECM LIGHT TRRN DRIVEN TONIGHT.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...SCATTERED SHOWERS AND
THUNDERSTORMS WL BE POSSIBLE MONDAY AND AGAIN ON WEDS/THURS. THIS
ACTIVITY WL HAVE THE POTENTIAL TO PRODUCE BRIEF PERIODS OF MVFR
CONDITIONS ALONG WITH LOCALIZED GUSTY WINDS IN AND NEAR STORMS.
ALSO...LOOK FOR SOME BR/FOG TO DEVELOP IF SKIES CAN
CLR...ESPECIALLY AT MPV/SLK BTWN 07-11Z...WITH GENERALLY SOUTH TO
SOUTHWEST WINDS THRU THE PERIOD.
&&
.HYDROLOGY...
AS OF 435 PM EDT SUNDAY... LOCALLY HEAVY RAINFALL WILL REMAIN
POSSIBLE ACROSS THE SOUTHERN PORTIONS OF THE FORECAST AREA THIS
EVENING...AND ACROSS THE ENTIRE AREA ON MONDAY. WHILE WIDESPREAD
OR ORGANIZED AREAS OF FLASH FLOODING ARE NOT EXPECTED...WCD VALUES
WILL REMAIN QUITE HIGH ALONG WITH HIGH COLUMNAR MOISTURE PROFILES.
THUS POINT TOTALS IN EXCESS OF ONE INCH IN AN HOUR OR LESS WILL BE
POSSIBLE...WHICH CHOULD LEAD TO LOCALIZED HYDROLOGICAL
CONCERNS...ESPECIALLY ON MONDAY WHEN BOUNDARY LAYER FLOW WILL BE
QUITE LIGHT BELOW 850 MB.
&&
.EQUIPMENT...
AS OF 415 AM EDT SUNDAY...THE KTYX RADAR IS DOWN UNTIL FURTHER
NOTICE. TECHS HAVE ORDERED PARTS...WHICH SHOULD ARRIVE ON MONDAY
AND THE RADAR SHOULD BE RETURNED TO SERVICE BY TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...JMG
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BUFFALO NY
332 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A PERSISTENT TROUGH OF LOW PRESSURE WILL GRADUALLY SLIDE EASTWARD
ACROSS THE REGION EARLY NEXT WEEK. THIS WILL RESULT IN CONTINUED
UNSETTLED WEATHER THROUGH MID-WEEK BEFORE DRIER AIR FINALLY
ARRIVES BY THE END OF THE WEEK AS HIGH PRESSURE BUILDS INTO THE
GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF MID-AFTERNOON...RADAR SHOWS MOST OF WESTERN NEW YORK IS
SHOWER-FREE...WITH JUST A FEW SHOWERS STARTING TO DEVELOP ACROSS
WESTERN PORTIONS OF THE SOUTHERN TIER. MEANWHILE...THE MOST
NOTEWORTHY FEATURE IS CONVECTION DEVELOPING ACROSS CENTRAL
PENNSYLVANIA. BOTH THE GFS/HRRR HANDLED AN INITIAL WAVE OF
CONVECTION EARLY THIS MORNING...AND IT APPEARS THESE MODELS ALSO
HAVE A GOOD HANDLE ON THE NEXT WAVE AS WELL. USING THIS
GUIDANCE...EXPECT THAT ORGANIZED CONVECTION WILL TRACK TO OUR
SOUTHEAST THROUGH EARLY EVENING. THIS LEAVES ONLY SUBTLE SURFACE
BOUNDARIES TO PROVIDE THE FOCUS NEEDED FOR SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON. THERE WILL BE LAKE BREEZES BOTH EAST OF LAKE
ERIE...AND SOUTH AND EAST OF THE EASTERN HALF OF LAKE ONTARIO. IN
EACH CASE...EXPECT ANY SHOWERS TO BE SCATTERED IN NATURE...WITH A
FEW THUNDERSTORMS ALSO POSSIBLE. NE OF LAKE ONTARIO AND LAKE
ERIE...EXPECT THE WELL DEVELOPED SW FLOW TO STABILIZE THE BOUNDARY
LAYER...AND KEEP THE BUFFALO METRO AREA DRY THIS AFTERNOON...EVEN IF HIGH
CLOUDS FROM UPSTREAM LIMIT SUNSHINE.
FOR THIS EVENING...CONVECTION ACROSS PENNSYLVANIA SHOULD REMAIN TO
THE SOUTH...WITH MOST OF THE DIURNALLY DRIVEN SHOWERS LIKELY TO
TAPER OFF. HOWEVER...THERE IS SOME INDICATION THAT SHOWERS
MAY DEVELOP ACROSS CENTRAL NEW YORK IF AN OUTFLOW FROM THE
CONVECTION TO THE SOUTH INTERACTS WITH LINGERING INSTABILITY IN THE
REGION. THIS AREA WILL ALSO BE UNDERNEATH A DIFLUENT FLOW ALOFT
AHEAD OF AN APPROACHING UPPER LOW...WHICH WOULD ENHANCE THE
CONVECTIVE POTENTIAL. THIS POSSIBILITY IS SHOWN BY THE HRRR AND 12Z
RGEM...AND TO A LESSER EXTENT 12Z GFS/NAM. IT IS MOST LIKELY TO STAY
SE OF OUR CWA...BUT MAY REACH INTO THE FINGER LAKES REGION. THIS
FEATURE BEARS WATCHING GIVING THE CONTINUED MOIST ENVIRONMENT WITH
PRECIPTABLE WATER VALUES STILL IN THE 1.75 INCH RANGE. SLOW MOVING
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AND FLOODING.
OTHERWISE...AN UPPER LEVEL TROF IS FORECAST TO SLOWLY LIFT ACROSS
WESTERN PENNSYLVANIA OVERNIGHT. THIS WILL BRING A CHANCE OF MORE
GENERAL SHOWER ACTIVITY...HOWEVER IT SHOULD BE SOMEWHAT SPOTTY IN
NATURE. AS HAS BEEN THE CASE...SOME PATCHY FOG IS POSSIBLE IN THE
SOUTHERN TIER VALLEYS...AND EAST OF LAKE ONTARIO. LOWS SHOULD
RANGE FROM THE MID 60S TO AROUND 70.
ON MONDAY...THE CLOSED UPPER LEVEL LOW WILL GRADUALLY OPEN AS IT
SLIDES TO THE EAST. THIS FEATURE WILL RESULT IN A CONTINUED THREAT
FOR SHOWERS DURING THE DAY MONDAY...AS DAYTIME INSTABILITY ENHANCES
SHOWER ACTIVITY. SLIGHTLY COOLER TEMPERATURES ALOFT SHOULD ALLOW
STORMS TO DEVELOP LIGHTNING A BIT MORE QUICKLY THAN THE PAST COUPLE
DAYS. AS THE OPENING TROF EXITS TO THE EAST...EXPECT DRYING WITH THE
SUBSTANCE ASSOCIATED WITH THE EXITING FEATURE. AS A RESULT...SHOWERS
AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST DURING THE
AFTERNOON HOURS. TEMPERATURES WILL BE A TAD COOLER...WITH HIGHS INT
HE UPPER 70S TO LOWER 80S. IT WILL CONTINUE TO BE MOIST RESULTING IN
CONTINUED MUGGY CONDITIONS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...
AS THE AXIS OF THE UPPER TROUGH WILL HAVE PASSED TO THE EAST OF
THE FORECAST AREA...EXPECT A SHARP DROP OFF IN POPS FOR MONDAY
NIGHT. WARM ADVECTION THROUGHOUT THE BOUNDARY LAYER WILL ARRIVE IN
WESTERN AND SOUTHERN NY ON TUESDAY WITH INCREASING BUT STILL LOW
CHANCE OF THUNDERSTORMS ACROSS THE SOUTHERN TIER...MAINLY DURING
TUESDAY AFTERNOON. TEMPS MONDAY NIGHT WILL BE IN THE LOWER TO MID
60S ACROSS THE SOUTHERN TIER AND TUG HILL...AND MID 60S TO NEAR 70
FOR THE LAKE PLAINS AND URBAN AREAS. HIGHS ON TUESDAY WILL RISE A
NOTCH TO THE LOWER TO MID 80S.
A TROUGH MOVING ACROSS ONTARIO PROVINCE WILL SPAWN A SURFACE LOW
OVER THE UPPER MID WEST ON TUESDAY TO SOUTH OF JAMES BAY ON
WEDNESDAY. 35 TO 40 KNOT WINDS AT 850MB ACROSS THE CENTRAL GREAT
LAKES WILL FORM A WARM FRONT ASSOCIATED WITH THE SURFACE LOW.
INCREASING MOISTURE AHEAD OF THE WARM FRONT...PRECIPITABLE WATER
RISING BACK TO NEAR 2 INCHES...AND ADDED LIFT IN THE VICINITY OF THE
SHORT WAVE TROUGH WILL BRING A GOOD CHANCE FOR SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. UNSETTLED WEATHER WILL
CONTINUE WEDNESDAY NIGHT AS A COLD FRONT...TRAILING SOUTH OF LOW
PRESSURE NEAR JAMES BAY...PUSHES EAST ACROSS THE STATE. TEMPS
TUESDAY NIGHT WILL RANGE FROM THE MID 60S ACROSS THE SOUTHERN TIER
AND TUG HILL...TO LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS.
HIGHS ON WEDNESDAY WILL BE SIMILAR TO TUESDAY...LOWER TO MID
80S...EVEN WITH THICKER CLOUD AND OCCURRENCE OF PRECIP.
DRIER AND MARGINALLY COOLER AIR WILL ARRIVE IN THE POSTFRONTAL
AIRMASS ON THURSDAY WITH LOWER CHANCE POPS AND PARTIAL CLEARING.
EXPECT HIGHS IN THE MID TO UPPER 70S ON THURSDAY AND LOWS THURSDAY
NIGHT IN THE UPPER 50S TO LOWER 60S AS SKIES CLEAR FURTHER.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
THE UPPER TROUGH ACROSS ONTARIO WILL STALL AND DIG FARTHER
SOUTH...DEVELOPING A CUTOFF LOW ACROSS THE EASTERN U.S. THIS LOW
WILL DROP FARTHER TO THE SOUTH ON THE WEEKEND AND BLOCK THE WARMER
AIR FROM THE NATION`S MIDSECTION...ALSO TAPPING INTO MOISTURE FROM
THE WESTERN ATLANTIC. FRIDAY AND FRIDAY NIGHT SHOULD REMAIN DRY
AND QUITE COOLER WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 50S
TO LOW 60S. HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
ARRIVE DURING SATURDAY AND SUNDAY AS THE SOUTHEASTERLY LOW LEVEL
FLOW FROM THE MID ATLANTIC INTERACTS WITH THE MID AND UPPER LEVEL
TROUGH. HIGH TEMPS FOR THE WEEKEND WILL BE IN THE MID TO UPPER 70S
ON SATURDAY AND THE UPPER 70S TO LOWER 80S ON SUNDAY.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
EXPECT MAINLY VFR CONDITIONS FOR THE REMAINDER OF THIS
AFTERNOON...WITH LINGERING MVFR CIGS LIKELY TO LIFT AND SCATTER.
THERE MAY BE A FEW SHOWERS AND THUNDERSTORMS...BUT EXPECT THE SW
FLOW TO KEEP THESE OUT OF BUF/IAG/ART/ROC...WHICH TEND TO BE
SHADOWED IN THIS FLOW. JHW MAY SEE A THUNDERSTORM THIS
AFTERNOON...BUT CONFIDENCE IS RELATIVELY LOW GIVEN STORMS SHOULD
BE QUITE SCATTERED.
FOR TONIGHT...EXPECT MORE SCATTERED SHOWERS AS THE UPPER LOW MOVES
CLOSER TO THE REGION. THERE WILL BE QUITE A BIT OF LOW LEVEL
MOISTURE IN PLACE...BUT AS LONG AS WINDS PERSIST AND THE MID AND
HIGH CLOUDS REMAIN...EXPECT CIGS TO REMAIN MAINLY IN THE VFR
RANGE. THIS SAID...ANY PROLONGED CLEARING WOULD LIKELY RESULT IN
LOW CLOUDS AND FOG...WITH THE BEST CHANCE FOR THIS AT JHW/ART.
THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND POSSIBLY A
THUNDERSTORM ON MONDAY. EXPECT MAINLY VFR CONDITIONS EXCEPT IN
STORMS WHERE HEAVY RAINS COULD LOWER VSBY TO 2SM OR LESS.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED
SHOWERS AND THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR
CONDITIONS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS HAVE INCREASED ON LAKE ERIE AND WESTERN LAKE ONTARIO...HOWEVER
THE STRONGEST WINDS ARE ON LAND WHERE WINDS ALOFT CAN MIX MORE
READILY. WEBCAMS AND OBS SHOW ONLY MODEST WAVES WITH NO WHITE
CAPS ALONG THE NEARSHORES OF LAKE ERIE. THERE MAY BE A DECENT CHOP ON
WESTERN LAKE ONTARIO...DUE TO SW GUSTS NEAR THE IMMEDIATE
SHORELINE...BUT WAVES SHOULD REMAIN WELL BELOW 4 FT SINCE WINDS
WILL DIMINISH OFFSHORE.
LIGHT TO MODERATE SOUTHWEST WINDS WILL CONTINUE TONIGHT THROUGH
MONDAY WITH CHOPPY WAVE ACTION AT TIMES ON BOTH LAKE...BUT
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 PM EDT SUN JUL 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
MONDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY DURING
THE AFTERNOON. SINCE THE AIRMASS REMAINS VERY MOIST ANY
THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL. THE UPPER
LEVEL TROUGH WILL EXIT THE NORTHEASTERN UNITED STATES MONDAY NIGHT
BRINGING A BRIEF END TO THE RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
845 AM UPDATE...
EARLY MRNG MCS HAS MOVD EAST AND IS ENTERING WRN NEW
ENGLAND...WITH FCST AREA UNDER PC SKIES. TDA`S SCENARIO IS NOT
MUCH DIFFERENT FROM PREV DAYS. UPR LOW OVER INDIANA THIS MRNG
WITH S/WV`S ROTATING NEWD FROM THE ERN OH VLY INTO THE NE U.S..
NXT S/WV IS OVER WRN WV WHICH WILL BE HEADING NEWD TWDS WRN NY LATE
TDA. OTHER THAN THIS FEATURE...THERE IS NOT MUCH TO FOCUS
CONVECTIVE DVLPMNT TDA OTHER THAN ANY MESO-BETA BNDRYS AND TRRN
FEATURES.
IN THE NEAR TERM WE LOWERED POPS INTO EARLY AFTN AND REMOVED ANY
QPF BEFORE 18Z...THEN CHC POPS THIS AFTN FOR SCT SHRA/TSRA. WIND
SHEAR TDA IS MARGINAL FOR ORGANIZED STORMS AND IS ACTUALLY LOWERING
THIS MRNG INTO EARLY AFTN...BUT INCREASES TO MARGINALLLY
SUPPORTIVE VALUES ACRS WRN ZONES LATE TDA WITH APRCH OF NXT S/WV.
GIVEN MOIST CONDITIONS...LCL +RA WILL BE MAIN THREAT WITH ANY
STORMS TDA. PREV BLO...
630 AM UPDATE...
JUST DID ANOTHER MAJOR RE-WORK OF THE POPS GRIDS AS S/WV IS
EXITING STAGE RIGHT AT THIS TIME, TAKING THE STORMS WITH IT IN THE
NEXT HR. BASED ON LATEST RUC FCST AND CURRENT TRENDS NOT EXPECTING
MUCH IN THE WAY OF SHOWERS TO GET IN HERE BFR 15Z AND ONLY SCTD,
AT BEST, AFTER THAT TIME.
520 AM UPDATE...
QUICK UPDATE TO UP POPS ACRS UPSTATE NY TO 50% FOR CLUSTER OF
TSTMS MVG THRU NRN ZONES. ALSO UPPED QPF TO AROUND 0.25 INCHES
BASIN-AVERAGE THRU 12Z THO LOCALLY HIGHER AMNTS MAY EXIST.
330 AM UPDATE...
BERMUDA RIDGE CONTS TO SPIN OFF THE ATLANTIC COAST WITH PLENTIFUL
MOISTURE BEING PUMPED INTO CWA FM GOM. UL TROF/LOW IS ON THE MV AS
RIDGE IS WEAKENING. S/WV LOCATED ACRS OH/KY AREA WL APPCH THE FA
THIS AFTN AND RESULT IN A GOOD CHC FOR SHRA/TSRA ACTIVITY. THUS WL
GO WITH LKLY POPS ACRS WRN ZONES ARND 18Z OR SO THEN DIMINISHING AFT
THAT AS WV PASSES OFF TO THE WEST AND MID-LVL LAPSE RATES WEAKEN.
AS FOR SVR POTENTIAL, EXPECT ONLY A STRONG STORM OR TWO AS 0-6KM
BULK SHEAR VALUES WEAKEN THRU THE DAY. ANY TSTM THAT CAN DVLP WL HV
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AND LOCALIZED FLOODING
AND THIS WL LKLY BE THE MAIN THREAT FOR THIS AFTN.
H8 TEMPS TO ARND 17C TDA WL YIELD HIGHS IN THE M/U 80S SIMILAR TO
YDA.
FOR TONIGHT, UL LOW WL OPEN UP ACRS NRN OHIO BY 06Z AND BEGIN TO
EJECT EAST WITH SCTD THUNDER RMNG ACRS THE REGION THRU 12Z MONDAY.
EXPECTING OVRNGT MINS TO RMN UP IN THE U60S WITH DWPTS RMNG JUST A
DEGREE OR TWO LOWER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
330 AM UPDATE...
UPR TROF WL BE EJECTING OUT DRG THE DAY ON MONDAY WITH PW VALUES
GRADUALLY DROPPING THRU THE AFTN. POTENTIAL EXISTS FOR LCLY HVYR
RAINFALL THRU THE COURSE OF THE DAY WITH UL TROF INTERACTING WITH
FRONTAL BNDRY ACRS THE NERN U.S. THIS, IN ADDITION TO SATURATED SOIL
CONDS WL BRING A HEIGHTENED THREAT FOR FLOODING ON MONDAY. THUS, WL
HIGHLIGHT THREAT IN THE HWO.
PCPN SHUD GRADUALLY WIND DOWN MON NGT AS FLOW TRANSITIONS TO A MORE
ZONAL FLOW ALOFT. DIURNAL CONVECTION WL ONCE AGAIN BE POSSIBLE TUE
AFTN BFR TAPERING OFF TUE NGT, AHD OF NEXT H5 TROF HEADED IN FM THE
WEST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS ARE IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED PERIOD. WED NIGHT THROUGH THURSDAY, UPPER LEVEL TROF WILL
DROP THROUGH THE GREAT LAKES AS SFC COLD FRONT PASSES THROUGH THE
AREA LATE WED NIGHT THROUGH THURSDAY MORNING. WILL CONTINUE WITH
LIKELY POPS INTO THURSDAY MORNING THEN DROP BACK TO DRY WEST AND
JUST CHC EAST BY THURSDAY AFTERNOON.
THURSDAY NIGHT THROUGH SUNDAY...UPPER LEVEL TROF CUTS OFF OVER
THE REGION THEN RETROGRADES LATE IN THE PERIOD AS WESTERN ATLANTIC
RIDGE BUILDS. AT THE SFC, HIGH PRES WILL BUILD OVER THE AREA
AND DOMINATE OUR WEATHER THROUGH FRIDAY NIGHT WITH PRIMARILY DRY
CONDITIONS. SATURDAY THROUGH SUNDAY, AN INCREASINGLY MOIST
SOUTHEAST FLOW WILL DEVELOP LEADING TO HUMID CONDITIONS AND CHC
POPS FOR CONVECTION. HIGHEST POPS WILL BE OVER THE EASTERN CWA
IN AN AREA OF BETTER MOISTURE AND OROGRAPHIC LIFT.
TEMPS THROUGH THE PERIOD WILL BE NEAR SEASONAL NORMS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A VERY COMPLEX FORECAST NEXT 24 HRS. UPPER LEVEL LOW IN THE OHIO
VALLEY WILL TRACK NORTHEAST INTO CENTRAL PA BY MONDAY. FOR THIS
AFTERNOON, SCATTERED CONVECTION IS EXPECTED ALONG THE LAKE PLAIN
THEREFORE INCLUDED 4 HOUR TEMPS GROUP FOR MVFR RAIN SHOWERS AT
KRME/KSYR. THUNDERSTORMS ARE ALSO A POSSIBILITY BUT NOT INCLUDED
AT THIS TIME. FOR THE REMAINDER OF TAFS, WAVE IN SOUTHWEST PA MAY
INITIATE CONVECTION LATE THIS AFTERNOON THROUGH EARLY EVENING.
INCLUDED TEMPO GROUP FOR MVFR SHOWERS BUT AGAIN THUNDERSTORMS ARE
A POSSIBILITY. FOR A WHILE THIS EVENING CONDITIONS WILL BE
PRIMARILY VFR BUT MVFR STRATUS IS EXPECTED LATE TONIGHT AT ALL
SITES AS DEEPER MOISTURE SETTLES BACK OVER THE AREA WITH UPPER
LEVEL FEATURE. FOR MONDAY, JUST WENT WITH CATEGORICAL SHOWERS WITH
MVFR CIGS AFTER 15Z.
SOUTHWEST WINS AT 5-10 KNOTS BECOMING LIGHT OVERNIGHT THEN
SOUTHWEST AGAIN ON MONDAY.
.OUTLOOK...
MONDAY NIGHT...MVFR RESTRICTIONS PSBL IN EARLY MRNG STRATUS/FOG.
TUESDAY THROUGH TUESDAY NIGHT...PRIMARILY VFR.
WEDNESDAY THROUGH THURSDAY...RESTRICTIONS IN SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS.
THURSDAY NIGHT THROUGH FRIDAY...PRIMARILY VFR ALTHOUGH VALLEY FOG
IS POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...
SHORT TERM...PVN
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1206 PM EDT SUN JUL 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
MONDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY DURING
THE AFTERNOON. SINCE THE AIRMASS REMAINS VERY MOIST ANY
THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL. THE UPPER
LEVEL TROUGH WILL EXIT THE NORTHEASTERN UNITED STATES MONDAY NIGHT
BRINGING A BRIEF END TO THE RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
845 AM UPDATE...
EARLY MRNG MCS HAS MOVD EAST AND IS ENTERING WRN NEW
ENGLAND...WITH FCST AREA UNDER PC SKIES. TDA`S SCENARIO IS NOT
MUCH DIFFERENT FROM PREV DAYS. UPR LOW OVER INDIANA THIS MRNG
WITH S/WV`S ROTATING NEWD FROM THE ERN OH VLY INTO THE NE U.S..
NXT S/WV IS OVER WRN WV WHICH WILL BE HEADING NEWD TWDS WRN NY LATE
TDA. OTHER THAN THIS FEATURE...THERE IS NOT MUCH TO FOCUS
CONVECTIVE DVLPMNT TDA OTHER THAN ANY MESO-BETA BNDRYS AND TRRN
FEATURES.
IN THE NEAR TERM WE LOWERED POPS INTO EARLY AFTN AND REMOVED ANY
QPF BEFORE 18Z...THEN CHC POPS THIS AFTN FOR SCT SHRA/TSRA. WIND
SHEAR TDA IS MARGINAL FOR ORGANIZED STORMS AND IS ACTUALLY LOWERING
THIS MRNG INTO EARLY AFTN...BUT INCREASES TO MARGINALLLY
SUPPORTIVE VALUES ACRS WRN ZONES LATE TDA WITH APRCH OF NXT S/WV.
GIVEN MOIST CONDITIONS...LCL +RA WILL BE MAIN THREAT WITH ANY
STORMS TDA. PREV BLO...
630 AM UPDATE...
JUST DID ANOTHER MAJOR RE-WORK OF THE POPS GRIDS AS S/WV IS
EXITING STAGE RIGHT AT THIS TIME, TAKING THE STORMS WITH IT IN THE
NEXT HR. BASED ON LATEST RUC FCST AND CURRENT TRENDS NOT EXPECTING
MUCH IN THE WAY OF SHOWERS TO GET IN HERE BFR 15Z AND ONLY SCTD,
AT BEST, AFTER THAT TIME.
520 AM UPDATE...
QUICK UPDATE TO UP POPS ACRS UPSTATE NY TO 50% FOR CLUSTER OF
TSTMS MVG THRU NRN ZONES. ALSO UPPED QPF TO AROUND 0.25 INCHES
BASIN-AVERAGE THRU 12Z THO LOCALLY HIGHER AMNTS MAY EXIST.
330 AM UPDATE...
BERMUDA RIDGE CONTS TO SPIN OFF THE ATLANTIC COAST WITH PLENTIFUL
MOISTURE BEING PUMPED INTO CWA FM GOM. UL TROF/LOW IS ON THE MV AS
RIDGE IS WEAKENING. S/WV LOCATED ACRS OH/KY AREA WL APPCH THE FA
THIS AFTN AND RESULT IN A GOOD CHC FOR SHRA/TSRA ACTIVITY. THUS WL
GO WITH LKLY POPS ACRS WRN ZONES ARND 18Z OR SO THEN DIMINISHING AFT
THAT AS WV PASSES OFF TO THE WEST AND MID-LVL LAPSE RATES WEAKEN.
AS FOR SVR POTENTIAL, EXPECT ONLY A STRONG STORM OR TWO AS 0-6KM
BULK SHEAR VALUES WEAKEN THRU THE DAY. ANY TSTM THAT CAN DVLP WL HV
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AND LOCALIZED FLOODING
AND THIS WL LKLY BE THE MAIN THREAT FOR THIS AFTN.
H8 TEMPS TO ARND 17C TDA WL YIELD HIGHS IN THE M/U 80S SIMILAR TO
YDA.
FOR TONIGHT, UL LOW WL OPEN UP ACRS NRN OHIO BY 06Z AND BEGIN TO
EJECT EAST WITH SCTD THUNDER RMNG ACRS THE REGION THRU 12Z MONDAY.
EXPECTING OVRNGT MINS TO RMN UP IN THE U60S WITH DWPTS RMNG JUST A
DEGREE OR TWO LOWER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
330 AM UPDATE...
UPR TROF WL BE EJECTING OUT DRG THE DAY ON MONDAY WITH PW VALUES
GRADUALLY DROPPING THRU THE AFTN. POTENTIAL EXISTS FOR LCLY HVYR
RAINFALL THRU THE COURSE OF THE DAY WITH UL TROF INTERACTING WITH
FRONTAL BNDRY ACRS THE NERN U.S. THIS, IN ADDITION TO SATURATED SOIL
CONDS WL BRING A HEIGHTENED THREAT FOR FLOODING ON MONDAY. THUS, WL
HIGHLIGHT THREAT IN THE HWO.
PCPN SHUD GRADUALLY WIND DOWN MON NGT AS FLOW TRANSITIONS TO A MORE
ZONAL FLOW ALOFT. DIURNAL CONVECTION WL ONCE AGAIN BE POSSIBLE TUE
AFTN BFR TAPERING OFF TUE NGT, AHD OF NEXT H5 TROF HEADED IN FM THE
WEST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS ARE IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED PERIOD. WED NIGHT THROUGH THURSDAY, UPPER LEVEL TROF WILL
DROP THROUGH THE GREAT LAKES AS SFC COLD FRONT PASSES THROUGH THE
AREA LATE WED NIGHT THROUGH THURSDAY MORNING. WILL CONTINUE WITH
LIKELY POPS INTO THURSDAY MORNING THEN DROP BACK TO DRY WEST AND
JUST CHC EAST BY THURSDAY AFTERNOON.
THURSDAY NIGHT THROUGH SUNDAY...UPPER LEVEL TROF CUTS OFF OVER
THE REGION THEN RETROGRADES LATE IN THE PERIOD AS WESTERN ATLANTIC
RIDGE BUILDS. AT THE SFC, HIGH PRES WILL BUILD OVER THE AREA
AND DOMINATE OUR WEATHER THROUGH FRIDAY NIGHT WITH PRIMARILY DRY
CONDITIONS. SATURDAY THROUGH SUNDAY, AN INCREASINGLY MOIST
SOUTHEAST FLOW WILL DEVELOP LEADING TO HUMID CONDITIONS AND CHC
POPS FOR CONVECTION. HIGHEST POPS WILL BE OVER THE EASTERN CWA
IN AN AREA OF BETTER MOISTURE AND OROGRAPHIC LIFT.
TEMPS THROUGH THE PERIOD WILL BE NEAR SEASONAL NORMS.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
MAIN CONCERN HEADING INTO TODAY WILL BE POSSIBLE SHWRS/STORM
DEVELOPMENT LATER THIS AFTERNOON AS UPPER STORM SYSTEM APPROACHES
FROM THE SOUTHWEST. FOR NOW...FEEL BULK OF THE MORNING HRS SHOULD
BE PRECIP FREE WITH ACTIVITY THEN DEVELOPING AFTER 18Z. FCST
GUIDANCE SUGGESTING WEAK INSTABILITY LATER THIS AFTERNOON AND THUS
HAVE ADVERTISED A 3 HR TEMPO GROUP FOR THUNDER AT ALL SITES.
MOVING INTO TONIGHT...DIURNAL STORMS SHOULD COME TO AN END BEFORE
00Z WITH BULK OF ACTIVITY THEN TRANSITIONING BACK TO PLAIN SHWRS.
BEYOND 06Z...GUIDANCE SUGGESTS WIDESPREAD RESTRICTIONS DEVELOPING
HOWEVER CONTINUED SOUTHWEST FLOW LENDS ONLY MARGINAL CONFIDENCE OF
THIS SCENARIO DEVELOPING. DESPITE THIS...HAVE NUDGED TOWARDS
LOW-END MVFR UNTIL BETTER CONFIDENCE ARRIVES WITH FUTURE MODEL
GUIDANCE.
.OUTLOOK...
MONDAY THROUGH THURSDAY...SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...
SHORT TERM...PVN
LONG TERM...RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1012 AM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EAST COAST COMBINED WITH A MID LEVEL
LOW OVER THE OHIO VALLEY WILL KEEP A SOUTHERLY FLOW OF WARM AND VERY
MOIST AIR THROUGH THE REMAINDER OF THE WEEKEND WITH SCATTERED
SHOWERS AND THUNDERSTORMS...ESPECIALLY INLAND FROM THE LAKES. THE
UNSETTLED WEATHER WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK
BEFORE DRIER AIR FINALLY ARRIVES BY THE END OF THE WEEK AS HIGH
PRESSURE BUILDS INTO THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR LOOP SHOWS A COMPLEX OF SHOWERS ASSOCIATED WITH A MID-LEVEL
SHORTWAVE EXITING TO THE EAST LATE THIS MORNING. AS THIS
EXITS...THERE WILL LIKELY BE SOME DRYING IN ITS WAKE AS 700 MB
WINDS DIMINISH WHICH PROMOTE MID-LEVEL DIVERGENCE. THE MAJORITY OF MODEL
GUIDANCE DID NOT CAPTURE THIS FEATURE...AND AS SUCH PROBABLY WILL NOT
CAPTURE THE SUBSIDENCE IN PLACE BEHIND THE EXITING WAVE. THE 06Z
GFS AND HRRR DID CAPTURE THIS FEATURE...AND AS A RESULT WILL BE
HEAVILY WEIGHTED FOR TODAY/S FORECAST.
FOR THE REMAINDER OF TODAY...THERE MAY BE A FEW LINGERING SHOWERS
EAST OF LAKE ONTARIO IN ASSOCIATION WITH WEAK WARM ADVECTION THROUGH
LATE MORNING. OTHERWISE THIS MORNING SHOULD BE DRY. DAYTIME
HEATING WILL RESULT IN INCREASING INSTABILITY TODAY. FOLLOWING THE
GFS/HRRR GUIDANCE WHICH IS FAIRLY WELL ALIGNED WITH LATEST WATER
VAPOR IMAGERY...EXPECT THE LARGE SCALE AND/OR ORGANIZED CONVECTION
TO TRACK TO OUR SOUTH AND EAST THIS AFTERNOON. THIS WILL AGAIN
LEAVE MORE SUBTLE MESOSCALE FEATURES WHICH PROVIDE THE FOCUS FOR
CONVECTION FOR OUR AREA THIS AFTERNOON.
WITH THE ABOVE IN MIND...HAVE GONE WITH SCATTERED SHOWERS AND
ISOLATED THUNDER AGAIN FOR THE AFTERNOON FROM THE WESTERN SOUTHERN
TIER INTO THE FINGER LAKES. FARTHER NORTH...EXPECT MOST OF THE
NIAGARA FRONTIER EAST TO ROCHESTER TO REMAIN DRY GIVEN THE
DEVELOPING LAKE SHADOW AND LESS DEEP LAYER MOISTURE. IT WILL BE
ANOTHER WARM AND VERY MUGGY DAY WITH LOWER ELEVATIONS AWAY FROM LAKE
INFLUENCES REACHING THE MID 80S...WITH SOME SPOTS IN CENTRAL NY
REACHING THE UPPER 80S. THE HIGHER TERRAIN...NORTH COUNTRY...AND
LAKESHORES WILL BE A LITTLE COOLER...BUT STILL VERY MUGGY.
FROM A SYNOPTIC STANDPOINT...THE BERMUDA HIGH WILL REMAIN IN PLACE
FOR THE NEXT 24 HOURS AND BEYOND AS THE CUTOFF LOW OVER THE WESTERN
OHIO VALLEY ACCELERATES EAST AND REACHES WESTERN PA BY DAYBREAK
MONDAY AS IT RE-ENGAGES WITH THE WESTERLIES. THIS CUTOFF...AND THE
ASSOCIATED MID LEVEL TROUGH WILL BECOME THE MAIN FORECAST PLAYER
LATER TONIGHT.
THIS EVENING THE SHOWERS FROM THE WESTERN SOUTHERN TIER INTO CENTRAL
NY WILL SLOWLY DIMINISH AND PUSH EAST WITH THE LOSS OF DAYTIME
HEATING AND PASSAGE OF THE SUPPORTING SHORTWAVE. THE MAIN MID LEVEL
LOW WILL MAKE PROGRESS OVERNIGHT...REACHING WESTERN PA BY DAYBREAK
MONDAY. THE APPROACH OF THE MID LEVEL TROUGH WILL BRING AN INCREASE
IN LARGE SCALE ASCENT OVERNIGHT...AND A 900-700MB TROUGH DROPPING
SOUTHEAST OUT OF CANADA WILL LIKELY PROVIDE CONVERGENCE AND FOCUS
FOR A DEVELOPING AREA OF SHOWERS AND SCATTERED STORMS LATE TONIGHT.
WITH THIS IN MIND...HAVE RAMPED UP POPS TO LIKELY BY LATE TONIGHT
WITH THE APPROACH OF THIS FEATURE. IT WILL BE ANOTHER MUGGY NIGHT
WITH LOWS AROUND 70 ON THE LAKE PLAINS AND MID TO UPPER 60S FARTHER
INLAND.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
THE UPPER THROUGH WHICH HAS BEEN IN PLACE OVER THE MIDWESTERN STATES
WILL CONTINUE TO MOVE SLOWLY TO THE EAST AND TRACK ACROSS NEW YORK
STATE AND PA ON MONDAY. THE LIFT ASSOCIATED WITH THE SHORT WAVE
TROUGH WILL HAVE THE GREATEST IMPACT ON OUR AREA MONDAY
MORNING...BEFORE IT SHIFTS INTO EASTERN NEW YORK STATE AND NEW
ENGLAND DURING THE AFTERNOON. A WEAK WAVE THAT WILL BE TRACKING EAST
ACROSS A FRONT...STALLED JUST TO OUR NORTH...WILL GENERATE
ADDITIONAL LIFT AND WILL HELP TO FOCUS THE ABUNDANT LOW LEVEL
MOISTURE THAT STILL WILL BE IN PLACE. BASED ON THESE TRENDS...EXPECT
A HIGH LIKELIHOOD OF SHOWERS AND SCATTERED THUNDERSTORMS MONDAY
MORNING. AS THE PRIMARY SOURCES OF LIFT SHIFT TO OUR EAST DURING THE
AFTERNOON...WE SHOULD SEE A WEST TO EAST DECREASE IN PCPN.
WITH PRECIPITABLE WATER VALUES FORECAST TO RANGE FROM 1.5 INCH TO
1.75 INCH...ANY CONVECTION MAY PRODUCE HEAVY RAIN...BUT THERE SHOULD
BE SUFFICIENT DIRECTIONAL SHEAR TO KEEP CELLS FROM TRAINING OVER THE
SAME SMALL AREAS ALONG THE STORM TRACKS... LIMITING THE FLOOD THREAT.
AS THE UPPER SHORT WAVE TROUGH CONTINUES TO MOVE TO THE EAST MONDAY
NIGHT...WEAK RIDGING SHOULD PROVIDE US WITH MAINLY DRY WEATHER. HIGH
PRESSURE WILL REMAIN IN CONTROL FOR MOST OF TUESDAY...BUT LATE DAY
SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN THE FAR WEST AS A WARM
FRONT AND SHORT WAVE MOVE EAST TOWARD THE LOWER LAKES.
INCREASING MOISTURE (PWATS FORECAST TO RISE TO ABOUT 2 INCHES)
AHEAD OF THE WARM FRONT AND ADDED LIFT IN THE VICINITY OF THE SHORT
WAVE TROUGH WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT AND WEDNESDAY. UNSETTLED WEATHER WILL CONTINUE
WEDNESDAY NIGHT AS A COLD FRONT...TRAILING SOUTH OF LOW PRESSURE
NEAR JAMES BAY...PUSHES EAST ACROSS THE STATE.
TEMPERATURES ON MONDAY WILL BE CLOSE TO SEASONAL AVERAGES. WARMER
TEMPERATURES RETURN ON TUESDAY AND WEDNESDAY...ALONG WITH AN
INCREASE IN HUMIDITY...ESPECIALLY ON WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
A TRANSITION TO A HIGHER AMPLITUDE PATTERN ALOFT WILL TAKE PLACE
DURING THIS PERIOD...CHARACTERIZED BY A DIGGING TROUGH OVER THE
GREAT LAKES WHILE A RIDGE BUILDS OUT WEST. THIS PATTERN SHIFT WILL
RESULT IN A TREND TOWARD SLIGHTLY COOLER TEMPERATURES AND LOWER
HUMIDITY AS THE WEEK PROGRESSES.
AT THE SURFACE...THE COLD FRONT THAT WILL BE PUSHING EAST ACROSS THE
AREA WEDNESDAY NIGHT WILL REACH THE EAST COAST ON THURSDAY. WHILE
DRIER AIR WILL WORK IN BEHIND THE FRONT...COOLER AIR ASSOCIATED WITH
THE DEEPENING UPPER LEVEL TROUGH MAY GENERATE ENOUGH INSTABILITY FOR
A FEW MORE SHOWERS.
THE LATEST GUIDANCE NOW SUGGESTS THAT THE UPPER LEVEL TROUGH WILL
CUTOFF AND SETTLE OVER THE OHIO VALLEY AND LOWER LAKES FRIDAY AND
SATURDAY. AT THE SAME TIME...HIGH PRESSURE AT THE SURFACE IS
FORECAST TO BUILD EAST ACROSS THE GREAT LAKES. WHILE THE TROUGH MAY
ENHANCE INSTABILITY...THIS SYSTEM MAY BE STARVED FOR MOISTURE.
THEREFORE...WILL MAINTAIN ONLY LOW CHANCE OR SLIGHT CHANCE POPS FOR
FRIDAY AND SATURDAY. MOST OF THE RESULTANT RAIN FROM THIS WILL BE
ASSOCIATED WITH AN OFFSHORE COASTAL SYSTEM.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WHICH CROSSED
THE AREA DURING THE WEE HOURS OF THE MORNING IS RACING EAST INTO
EASTERN NY AND WEAKENING THIS MORNING. A FEW LEFTOVER MAINLY LIGHT
SHOWERS WILL CONTINUE ACROSS THE SAINT LAWRENCE VALLEY THROUGH LATE
MORNING...OTHERWISE THE REST OF THE AREA WILL REMAIN DRY. MOSTLY VFR
CONDITIONS WILL PREVAIL...ALTHOUGH A FEW PATCHES OF MVFR CIGS NEAR
KBUF-KIAG WILL PERSIST THROUGH MID MORNING.
ANOTHER MID LEVEL DISTURBANCE AND PLUME OF MOISTURE IS FORECAST TO
CROSS THE WESTERN SOUTHERN TIER AND FINGER LAKES LATER IN THE
AFTERNOON AND EARLY EVENING...AND THIS MAY PRODUCE ADDITIONAL
SCATTERED SHOWERS AND ISOLATED STORMS INCLUDING KJHW. CONDITIONS
WILL BE VFR MOST OF THE TIME...BUT ANY SHOWER OR THUNDERSTORM WILL
BRIEFLY DIP CIGS/VSBY TO MVFR/IFR. A SOUTHWEST FLOW OFF LAKES ERIE
AND ONTARIO SHOULD AID IN STABILIZING THE ATMOSPHERE ENOUGH TO KEEP
THE RISK OF SHOWERS LOW AT THE REST OF THE TAF SITES.
THIS EVENING ANY SHOWERS ACROSS THE SOUTHERN TIER AND FINGER LAKES
WILL WEAKEN. LATE TONIGHT YET ANOTHER MID LEVEL TROUGH WILL APPROACH
THE REGION AND TOUCH OFF MORE SHOWERS AND A FEW THUNDERSTORMS. AGAIN
MOST OF THE NIGHT SHOULD BE VFR...BUT BRIEF MVFR/IFR IS POSSIBLE IN
ANY OF THE HEAVIER SHOWERS.
OUTLOOK...
MONDAY THROUGH WEDNESDAY...MAINLY VFR WITH SCATTERED SHOWERS AND
THUNDERSTORMS AND ASSOCIATED BRIEF MVFR/IFR CONDITIONS.
THURSDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE SOME TODAY...ESPECIALLY ON LAKE ERIE
WHERE THE SOUTHWEST FLOW WILL CHANNEL UP THE LAKE. THIS WILL PRODUCE
CHOPPY WAVES IN THE 2-4 FOOT RANGE. FOR NOW WILL KEEP CONDITIONS
JUST BELOW SMALL CRAFT ADVISORY CRITERIA BUT THIS WILL NEED TO BE
MONITORED. LIGHT TO MODERATE SOUTHWEST WINDS WILL CONTINUE TONIGHT
THROUGH MONDAY WITH CHOPPY WAVE ACTION AT TIMES ON BOTH LAKE...BUT
CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT CRITERIA.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TJP
LONG TERM...TJP
AVIATION...HITCHCOCK
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
854 AM EDT SUN JUL 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
MONDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY DURING
THE AFTERNOON. SINCE THE AIRMASS REMAINS VERY MOIST ANY
THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL. THE UPPER
LEVEL TROUGH WILL EXIT THE NORTHEASTERN UNITED STATES MONDAY NIGHT
BRINGING A BRIEF END TO THE RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
845 AM UPDATE...
EARLY MRNG MCS HAS MOVD EAST AND IS ENTERING WRN NEW
ENGLAND...WITH FCST AREA UNDER PC SKIES. TDA`S SCENARIO IS NOT
MUCH DIFFERENT FROM PREV DAYS. UPR LOW OVER INDIANA THIS MRNG
WITH S/WV`S ROTATING NEWD FROM THE ERN OH VLY INTO THE NE U.S..
NXT S/WV IS OVER WRN WV WHICH WILL BE HEADING NEWD TWDS WRN NY LATE
TDA. OTHER THAN THIS FEATURE...THERE IS NOT MUCH TO FOCUS
CONVECTIVE DVLPMNT TDA OTHER THAN ANY MESO-BETA BNDRYS AND TRRN
FEATURES.
IN THE NEAR TERM WE LOWERED POPS INTO EARLY AFTN AND REMOVED ANY
QPF BEFORE 18Z...THEN CHC POPS THIS AFTN FOR SCT SHRA/TSRA. WIND
SHEAR TDA IS MARGINAL FOR ORGANIZED STORMS AND IS ACTUALLY LOWERING
THIS MRNG INTO EARLY AFTN...BUT INCREASES TO MARGINALLLY
SUPPORTIVE VALUES ACRS WRN ZONES LATE TDA WITH APRCH OF NXT S/WV.
GIVEN MOIST CONDITIONS...LCL +RA WILL BE MAIN THREAT WITH ANY
STORMS TDA. PREV BLO...
630 AM UPDATE...
JUST DID ANOTHER MAJOR RE-WORK OF THE POPS GRIDS AS S/WV IS
EXITING STAGE RIGHT AT THIS TIME, TAKING THE STORMS WITH IT IN THE
NEXT HR. BASED ON LATEST RUC FCST AND CURRENT TRENDS NOT EXPECTING
MUCH IN THE WAY OF SHOWERS TO GET IN HERE BFR 15Z AND ONLY SCTD,
AT BEST, AFTER THAT TIME.
520 AM UPDATE...
QUICK UPDATE TO UP POPS ACRS UPSTATE NY TO 50% FOR CLUSTER OF
TSTMS MVG THRU NRN ZONES. ALSO UPPED QPF TO AROUND 0.25 INCHES
BASIN-AVERAGE THRU 12Z THO LOCALLY HIGHER AMNTS MAY EXIST.
330 AM UPDATE...
BERMUDA RIDGE CONTS TO SPIN OFF THE ATLANTIC COAST WITH PLENTIFUL
MOISTURE BEING PUMPED INTO CWA FM GOM. UL TROF/LOW IS ON THE MV AS
RIDGE IS WEAKENING. S/WV LOCATED ACRS OH/KY AREA WL APPCH THE FA
THIS AFTN AND RESULT IN A GOOD CHC FOR SHRA/TSRA ACTIVITY. THUS WL
GO WITH LKLY POPS ACRS WRN ZONES ARND 18Z OR SO THEN DIMINISHING AFT
THAT AS WV PASSES OFF TO THE WEST AND MID-LVL LAPSE RATES WEAKEN.
AS FOR SVR POTENTIAL, EXPECT ONLY A STRONG STORM OR TWO AS 0-6KM
BULK SHEAR VALUES WEAKEN THRU THE DAY. ANY TSTM THAT CAN DVLP WL HV
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AND LOCALIZED FLOODING
AND THIS WL LKLY BE THE MAIN THREAT FOR THIS AFTN.
H8 TEMPS TO ARND 17C TDA WL YIELD HIGHS IN THE M/U 80S SIMILAR TO
YDA.
FOR TONIGHT, UL LOW WL OPEN UP ACRS NRN OHIO BY 06Z AND BEGIN TO
EJECT EAST WITH SCTD THUNDER RMNG ACRS THE REGION THRU 12Z MONDAY.
EXPECTING OVRNGT MINS TO RMN UP IN THE U60S WITH DWPTS RMNG JUST A
DEGREE OR TWO LOWER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
330 AM UPDATE...
UPR TROF WL BE EJECTING OUT DRG THE DAY ON MONDAY WITH PW VALUES
GRADUALLY DROPPING THRU THE AFTN. POTENTIAL EXISTS FOR LCLY HVYR
RAINFALL THRU THE COURSE OF THE DAY WITH UL TROF INTERACTING WITH
FRONTAL BNDRY ACRS THE NERN U.S. THIS, IN ADDITION TO SATURATED SOIL
CONDS WL BRING A HEIGHTENED THREAT FOR FLOODING ON MONDAY. THUS, WL
HIGHLIGHT THREAT IN THE HWO.
PCPN SHUD GRADUALLY WIND DOWN MON NGT AS FLOW TRANSITIONS TO A MORE
ZONAL FLOW ALOFT. DIURNAL CONVECTION WL ONCE AGAIN BE POSSIBLE TUE
AFTN BFR TAPERING OFF TUE NGT, AHD OF NEXT H5 TROF HEADED IN FM THE
WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A FAIRLY ACTIVE WX PATTERN EXPECTED TO PERSIST RIGHT THROUGH THE
CONCLUSION OF THE LONG TERM PERIOD AS A STRONG COLD FRONT PASSES
THROUGH THE AREA ON EARLY THURSDAY...FOLLOWED BY A AN UPPER
CLOSED LOW STALLING OVER THE TENNESSEE VALLEY BY WEEK/S END.
MODELS REMAIN IN EXCELLENT AGREEMENT ON THE TIMING OF THE
AFOREMENTIONED COLD FRONT WITH THE GFS...ECMWF AND CANADIAN-CMC
SOLUTIONS ALL FAVORING AN LATE WED/EARLY THU MORNING PASSAGE. FROM
THIS VANTAGE POINT...THE SLIGHTLY EARLIER FROPA TIMING FROM
YESTERDAY/S RUNS WILL LIKELY YIELD LITTLE THREAT FOR SEVERE WX AS
THE FRONT SHOULD BE EAST OF MUCH OF THE FORECAST AREA BY THU
AFTERNOON/S PEAK HEATING CYCLE. REGARDLESS...HAVE MAINTAINED
LIKELY POPS BOTH WED NGT AND THU AS MODELS SHOW PLENTY OF QPF IN
THE WARM SECTOR PRIOR TO AND DURING FRONTAL PASSAGE. BY FRI...FCST
MODELS SHOW SFC HIGH PRESSURE BUILDING INTO THE REGION WHICH
SHOULD YIELD OF BRIEF REPRIEVE FROM SHWR ACTIVITY. BY THE
WEEKEND...BOTH GFS AND ECMWF SUGGEST UPPER-LEVEL ENERGY WILL
GRADUALLY SHEAR OFF FROM MAIN UPPER FLOW RESULTING IN THE
DEVELOPMENT OF A CLOSED UPPER LOW WHICH WILL GRADUALLY RETROGRADE
WEST FROM THE CENTRAL/NORTHERN APPALACHIANS INTO THE TENNESSEE
AND OHIO VLYS. AS THIS OCCURS...FCST GUIDANCE SHOWS A DEVELOPING
FETCH OF ATLANTIC MOISTURE WORKING NORTHWEST INTO THE
MID-ATLANTIC REGION WHICH SHOULD LEAD TO REDEVELOPING SHWRS BY
NEXT WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
MAIN CONCERN HEADING INTO TODAY WILL BE POSSIBLE SHWRS/STORM
DEVELOPMENT LATER THIS AFTERNOON AS UPPER STORM SYSTEM APPROACHES
FROM THE SOUTHWEST. FOR NOW...FEEL BULK OF THE MORNING HRS SHOULD
BE PRECIP FREE WITH ACTIVITY THEN DEVELOPING AFTER 18Z. FCST
GUIDANCE SUGGESTING WEAK INSTABILITY LATER THIS AFTERNOON AND THUS
HAVE ADVERTISED A 3 HR TEMPO GROUP FOR THUNDER AT ALL SITES.
MOVING INTO TONIGHT...DIURNAL STORMS SHOULD COME TO AN END BEFORE
00Z WITH BULK OF ACTIVITY THEN TRANSITIONING BACK TO PLAIN SHWRS.
BEYOND 06Z...GUIDANCE SUGGESTS WIDESPREAD RESTRICTIONS DEVELOPING
HOWEVER CONTINUED SOUTHWEST FLOW LENDS ONLY MARGINAL CONFIDENCE OF
THIS SCENARIO DEVELOPING. DESPITE THIS...HAVE NUDGED TOWARDS
LOW-END MVFR UNTIL BETTER CONFIDENCE ARRIVES WITH FUTURE MODEL
GUIDANCE.
.OUTLOOK...
MONDAY THROUGH THURSDAY...SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...
SHORT TERM...PVN
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
702 AM EDT SUN JUL 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
MONDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY DURING
THE AFTERNOON. SINCE THE AIRMASS REMAINS VERY MOIST ANY
THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL. THE UPPER
LEVEL TROUGH WILL EXIT THE NORTHEASTERN UNITED STATES MONDAY NIGHT
BRINGING A BRIEF END TO THE RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
JUST DID ANOTHER MAJOR RE-WORK OF THE POPS GRIDS AS S/WV IS
EXITING STAGE RIGHT AT THIS TIME, TAKING THE STORMS WITH IT IN THE
NEXT HR. BASED ON LATEST RUC FCST AND CURRENT TRENDS NOT EXPECTING
MUCH IN THE WAY OF SHOWERS TO GET IN HERE BFR 15Z AND ONLY SCTD,
AT BEST, AFTER THAT TIME.
520 AM UPDATE...
QUICK UPDATE TO UP POPS ACRS UPSTATE NY TO 50% FOR CLUSTER OF
TSTMS MVG THRU NRN ZONES. ALSO UPPED QPF TO AROUND 0.25 INCHES
BASIN-AVERAGE THRU 12Z THO LOCALLY HIGHER AMNTS MAY EXIST.
330 AM UPDATE...
BERMUDA RIDGE CONTS TO SPIN OFF THE ATLANTIC COAST WITH PLENTIFUL
MOISTURE BEING PUMPED INTO CWA FM GOM. UL TROF/LOW IS ON THE MV AS
RIDGE IS WEAKENING. S/WV LOCATED ACRS OH/KY AREA WL APPCH THE FA
THIS AFTN AND RESULT IN A GOOD CHC FOR SHRA/TSRA ACTIVITY. THUS WL
GO WITH LKLY POPS ACRS WRN ZONES ARND 18Z OR SO THEN DIMINISHING AFT
THAT AS WV PASSES OFF TO THE WEST AND MID-LVL LAPSE RATES WEAKEN.
AS FOR SVR POTENTIAL, EXPECT ONLY A STRONG STORM OR TWO AS 0-6KM
BULK SHEAR VALUES WEAKEN THRU THE DAY. ANY TSTM THAT CAN DVLP WL HV
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AND LOCALIZED FLOODING
AND THIS WL LKLY BE THE MAIN THREAT FOR THIS AFTN.
H8 TEMPS TO ARND 17C TDA WL YIELD HIGHS IN THE M/U 80S SIMILAR TO
YDA.
FOR TONIGHT, UL LOW WL OPEN UP ACRS NRN OHIO BY 06Z AND BEGIN TO
EJECT EAST WITH SCTD THUNDER RMNG ACRS THE REGION THRU 12Z MONDAY.
EXPECTING OVRNGT MINS TO RMN UP IN THE U60S WITH DWPTS RMNG JUST A
DEGREE OR TWO LOWER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
330 AM UPDATE...
UPR TROF WL BE EJECTING OUT DRG THE DAY ON MONDAY WITH PW VALUES
GRADUALLY DROPPING THRU THE AFTN. POTENTIAL EXISTS FOR LCLY HVYR
RAINFALL THRU THE COURSE OF THE DAY WITH UL TROF INTERACTING WITH
FRONTAL BNDRY ACRS THE NERN U.S. THIS, IN ADDITION TO SATURATED SOIL
CONDS WL BRING A HEIGHTENED THREAT FOR FLOODING ON MONDAY. THUS, WL
HIGHLIGHT THREAT IN THE HWO.
PCPN SHUD GRADUALLY WIND DOWN MON NGT AS FLOW TRANSITIONS TO A MORE
ZONAL FLOW ALOFT. DIURNAL CONVECTION WL ONCE AGAIN BE POSSIBLE TUE
AFTN BFR TAPERING OFF TUE NGT, AHD OF NEXT H5 TROF HEADED IN FM THE
WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A FAIRLY ACTIVE WX PATTERN EXPECTED TO PERSIST RIGHT THROUGH THE
CONCLUSION OF THE LONG TERM PERIOD AS A STRONG COLD FRONT PASSES
THROUGH THE AREA ON EARLY THURSDAY...FOLLOWED BY A AN UPPER
CLOSED LOW STALLING OVER THE TENNESSEE VALLEY BY WEEK/S END.
MODELS REMAIN IN EXCELLENT AGREEMENT ON THE TIMING OF THE
AFOREMENTIONED COLD FRONT WITH THE GFS...ECMWF AND CANADIAN-CMC
SOLUTIONS ALL FAVORING AN LATE WED/EARLY THU MORNING PASSAGE. FROM
THIS VANTAGE POINT...THE SLIGHTLY EARLIER FROPA TIMING FROM
YESTERDAY/S RUNS WILL LIKELY YIELD LITTLE THREAT FOR SEVERE WX AS
THE FRONT SHOULD BE EAST OF MUCH OF THE FORECAST AREA BY THU
AFTERNOON/S PEAK HEATING CYCLE. REGARDLESS...HAVE MAINTAINED
LIKELY POPS BOTH WED NGT AND THU AS MODELS SHOW PLENTY OF QPF IN
THE WARM SECTOR PRIOR TO AND DURING FRONTAL PASSAGE. BY FRI...FCST
MODELS SHOW SFC HIGH PRESSURE BUILDING INTO THE REGION WHICH
SHOULD YIELD OF BRIEF REPRIEVE FROM SHWR ACTIVITY. BY THE
WEEKEND...BOTH GFS AND ECMWF SUGGEST UPPER-LEVEL ENERGY WILL
GRADUALLY SHEAR OFF FROM MAIN UPPER FLOW RESULTING IN THE
DEVELOPMENT OF A CLOSED UPPER LOW WHICH WILL GRADUALLY RETROGRADE
WEST FROM THE CENTRAL/NORTHERN APPALACHIANS INTO THE TENNESSEE
AND OHIO VLYS. AS THIS OCCURS...FCST GUIDANCE SHOWS A DEVELOPING
FETCH OF ATLANTIC MOISTURE WORKING NORTHWEST INTO THE
MID-ATLANTIC REGION WHICH SHOULD LEAD TO REDEVELOPING SHWRS BY
NEXT WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MAIN CONCERN HEADING INTO TODAY WILL BE POSSIBLE SHWRS/STORM
DEVELOPMENT LATER THIS AFTERNOON AS UPPER STORM SYSTEM APPROACHES
FROM THE SOUTHWEST. FOR NOW...FEEL BULK OF THE MORNING HRS SHOULD
BE PRECIP FREE WITH ACTIVITY THEN DEVELOPING AFTER 18Z. FCST
GUIDANCE SUGGESTING WEAK INSTABILITY LATER THIS AFTERNOON AND THUS
HAVE ADVERTISED A 3 HR TEMPO GROUP FOR THUNDER AT ALL SITES.
MOVING INTO TONIGHT...DIURNAL STORMS SHOULD COME TO AN END BEFORE
00Z WITH BULK OF ACTIVITY THEN TRANSITIONING BACK TO PLAIN SHWRS.
BEYOND 06Z...GUIDANCE SUGGESTS WIDESPREAD RESTRICTIONS DEVELOPING
HOWEVER CONTINUED SOUTHWEST FLOW LENDS ONLY MARGINAL CONFIDENCE OF
THIS SCENARIO DEVELOPING. DESPITE THIS...HAVE NUDGED TOWARDS
LOW-END MVFR UNTIL BETTER CONFIDENCE ARRIVES WITH FUTURE MODEL
GUIDANCE.
.OUTLOOK...
MONDAY THROUGH THURSDAY...SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
629 AM EDT SUN JUL 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL PERSIST OVER THE REGION THROUGH
MONDAY WITH SCATTERED SHOWERS AND THUNDERSTORMS, PRIMARILY DURING
THE AFTERNOON. SINCE THE AIRMASS REMAINS VERY MOIST ANY
THUNDERSTORMS MAY PRODUCE LOCALIZED HEAVY RAINFALL. THE UPPER
LEVEL TROUGH WILL EXIT THE NORTHEASTERN UNITED STATES MONDAY NIGHT
BRINGING A BRIEF END TO THE RAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
JUST DID ANOTHER MAJOR RE-WORK OF THE POPS GRIDS AS S/WV IS
EXITING STAGE RIGHT AT THIS TIME, TAKING THE STORMS WITH IT IN THE
NEXT HR. BASED ON LATEST RUC FCST AND CURRENT TRENDS NOT EXPECTING
MUCH IN THE WAY OF SHOWERS TO GET IN HERE BFR 15Z AND ONLY SCTD,
AT BEST, AFTER THAT TIME.
520 AM UPDATE...
QUICK UPDATE TO UP POPS ACRS UPSTATE NY TO 50% FOR CLUSTER OF
TSTMS MVG THRU NRN ZONES. ALSO UPPED QPF TO AROUND 0.25 INCHES
BASIN-AVERAGE THRU 12Z THO LOCALLY HIGHER AMNTS MAY EXIST.
330 AM UPDATE...
BERMUDA RIDGE CONTS TO SPIN OFF THE ATLANTIC COAST WITH PLENTIFUL
MOISTURE BEING PUMPED INTO CWA FM GOM. UL TROF/LOW IS ON THE MV AS
RIDGE IS WEAKENING. S/WV LOCATED ACRS OH/KY AREA WL APPCH THE FA
THIS AFTN AND RESULT IN A GOOD CHC FOR SHRA/TSRA ACTIVITY. THUS WL
GO WITH LKLY POPS ACRS WRN ZONES ARND 18Z OR SO THEN DIMINISHING AFT
THAT AS WV PASSES OFF TO THE WEST AND MID-LVL LAPSE RATES WEAKEN.
AS FOR SVR POTENTIAL, EXPECT ONLY A STRONG STORM OR TWO AS 0-6KM
BULK SHEAR VALUES WEAKEN THRU THE DAY. ANY TSTM THAT CAN DVLP WL HV
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AND LOCALIZED FLOODING
AND THIS WL LKLY BE THE MAIN THREAT FOR THIS AFTN.
H8 TEMPS TO ARND 17C TDA WL YIELD HIGHS IN THE M/U 80S SIMILAR TO
YDA.
FOR TONIGHT, UL LOW WL OPEN UP ACRS NRN OHIO BY 06Z AND BEGIN TO
EJECT EAST WITH SCTD THUNDER RMNG ACRS THE REGION THRU 12Z MONDAY.
EXPECTING OVRNGT MINS TO RMN UP IN THE U60S WITH DWPTS RMNG JUST A
DEGREE OR TWO LOWER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
330 AM UPDATE...
UPR TROF WL BE EJECTING OUT DRG THE DAY ON MONDAY WITH PW VALUES
GRADUALLY DROPPING THRU THE AFTN. POTENTIAL EXISTS FOR LCLY HVYR
RAINFALL THRU THE COURSE OF THE DAY WITH UL TROF INTERACTING WITH
FRONTAL BNDRY ACRS THE NERN U.S. THIS, IN ADDITION TO SATURATED SOIL
CONDS WL BRING A HEIGHTENED THREAT FOR FLOODING ON MONDAY. THUS, WL
HIGHLIGHT THREAT IN THE HWO.
PCPN SHUD GRADUALLY WIND DOWN MON NGT AS FLOW TRANSITIONS TO A MORE
ZONAL FLOW ALOFT. DIURNAL CONVECTION WL ONCE AGAIN BE POSSIBLE TUE
AFTN BFR TAPERING OFF TUE NGT, AHD OF NEXT H5 TROF HEADED IN FM THE
WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A FAIRLY ACTIVE WX PATTERN EXPECTED TO PERSIST RIGHT THROUGH THE
CONCLUSION OF THE LONG TERM PERIOD AS A STRONG COLD FRONT PASSES
THROUGH THE AREA ON EARLY THURSDAY...FOLLOWED BY A AN UPPER
CLOSED LOW STALLING OVER THE TENNESSEE VALLEY BY WEEK/S END.
MODELS REMAIN IN EXCELLENT AGREEMENT ON THE TIMING OF THE
AFOREMENTIONED COLD FRONT WITH THE GFS...ECMWF AND CANADIAN-CMC
SOLUTIONS ALL FAVORING AN LATE WED/EARLY THU MORNING PASSAGE. FROM
THIS VANTAGE POINT...THE SLIGHTLY EARLIER FROPA TIMING FROM
YESTERDAY/S RUNS WILL LIKELY YIELD LITTLE THREAT FOR SEVERE WX AS
THE FRONT SHOULD BE EAST OF MUCH OF THE FORECAST AREA BY THU
AFTERNOON/S PEAK HEATING CYCLE. REGARDLESS...HAVE MAINTAINED
LIKELY POPS BOTH WED NGT AND THU AS MODELS SHOW PLENTY OF QPF IN
THE WARM SECTOR PRIOR TO AND DURING FRONTAL PASSAGE. BY FRI...FCST
MODELS SHOW SFC HIGH PRESSURE BUILDING INTO THE REGION WHICH
SHOULD YIELD OF BRIEF REPRIEVE FROM SHWR ACTIVITY. BY THE
WEEKEND...BOTH GFS AND ECMWF SUGGEST UPPER-LEVEL ENERGY WILL
GRADUALLY SHEAR OFF FROM MAIN UPPER FLOW RESULTING IN THE
DEVELOPMENT OF A CLOSED UPPER LOW WHICH WILL GRADUALLY RETROGRADE
WEST FROM THE CENTRAL/NORTHERN APPALACHIANS INTO THE TENNESSEE
AND OHIO VLYS. AS THIS OCCURS...FCST GUIDANCE SHOWS A DEVELOPING
FETCH OF ATLANTIC MOISTURE WORKING NORTHWEST INTO THE
MID-ATLANTIC REGION WHICH SHOULD LEAD TO REDEVELOPING SHWRS BY
NEXT WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AREA RADARS THIS MORNING SHOWING DEVELOPING CONVECTION THIS HR
ACROSS WESTERN NY IN ADVANCE OF A SHORTWAVE DISTURBANCE LIFTING
NORTH THROUGH EASTERN OHIO. SO FAR THIS ACTIVITY HAS SHOWN A
WEAKENING TREND AS IT PROGRESSES EAST AND THUS HAVE NOT
HIGHLIGHTED THUNDER IN ANY TERMINALS OUT OF THE GATE THIS MORNING.
OBVIOUSLY TRENDS WILL HAVE TO BE WATCHED WITH AND UPDATES MADE ON
AN AS NEEDED BASIS.
UPSTREAM SATELLITE TRENDS ALSO SHOWING SOME PARTIAL CLEARING
WORKING NORTH FROM EASTERN PA THIS HR. AS A RESULT...MAIN CONCERN
FOR THE NEXT 6-HRS IN ADDITION TO THE CONVECTION WILL BE THE
POSSIBILITY FOR IFR VSBYS IN FOG AS WE PROGRESS THROUGH THE
MORNING. FOR NOW HAVE ADVERTISED BELOW ALTERNATE MIN CONDITIONS
DEVELOPING AT THE TERMINAL WITH DIURNAL IMPROVEMENTS LIKELY AFTER
11Z IF FOG DOES DEVELOP. ELSEWHERE...MVFR VSBYS POSSIBLE AT ITH
AND AVP AFTER THE 09Z TIME FRAME.
SHWRS EXPECTED TO BECOME MORE PREVALENT AS THE DAY CONTINUES AS A
STRONG UPPER-LEVEL DISTURBANCES GRADUALLY APPROACHES THE AREA.
STORMS WILL ALSO BE POSSIBLE BUT HAVE ELECTED TO HOLD OFF
MENTIONING FOR NOW BASED ON DISTANCE INTO THE FCST AND MARGINAL
CONFIDENCE.
WINDS WILL REMAIN FROM THE WEST BETWEEN 5-10 KTS THROUGH THE
PERIOD BEFORE WEAKENING THIS EVENING.
.OUTLOOK...
MONDAY THROUGH THURSDAY...SCT SHRA/TSRA ARE ANTICIPATED EACH
AFTN/EVE...WITH BRIEF RESTRICTIONS PSBL. MVFR RESTRICTIONS ALSO
PSBL IN EARLY MRNG STRATUS/FOG. OTRW VFR PREVAILS.
THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
350 PM EDT SUN JUL 7 2013
.SYNOPSIS...
THE BERMUDA HIGH WILL CONTINUE TO AFFECT THE LOCAL WEATHER THRU
OUT THE UPCOMING WEEK...HOWEVER ITS POSITIONING WILL SLIDE
SLIGHTLY FURTHER OFFSHORE DURING THE WEEK. THIS WILL ALLOW A COLD
FRONT TO SLOWLY APPROACH FROM THE NORTHWEST BY THE NEXT UPCOMING
WEEKEND. TYPICAL SUMMERTIME WEATHER WITH DAILY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS WILL OCCUR EACH DAY...INCREASING
IN COVERAGE AS WE APPROACH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...HIGH PRESSURE RIDGING INTO COASTAL CAROLINAS
FROM THE ATLANTIC WILL SHIFT SLIGHTLY EAST THROUGH TODAY. THIS
WILL ALLOW THE WINDS TO SHIFT TO MORE OF A SOUTH DIRECTION INLAND
WITH MORE OF A SOUTHEAST FLOW ALONG THE COAST...ENHANCED WITH AFTN
SEA BREEZE. STILL SEEING PLENTY OF DRY AIR THROUGH THE MID TO
UPPER LEVELS THROUGH TODAY WITH MOISTURE CONFINED TO LOW LEVELS
BELOW 5K FT. FLOW HAS VEERED SLIGHTLY THROUGH THE LOW LEVELS
COMING AROUND TO SOUTHWEST ABOVE THE SURFACE UP THROUGH H85. THIS
HAS KEPT BEST CONVERGENCE AROUND THE RIDGE CLOSER TO THE COAST
WHICH IN TURN HAS KEPT CLOUDS AND SHOWERS FROM PUSHING WELL
INLAND. CONTINUE TO EXPECT GOOD DEAL OF SUNSHINE ACROSS MUCH OF
THE AREA WITH ONLY ISOLATED SHWRS/TSTMS MAINLY ALONG SEA BREEZE
BOUNDARY AND FURTHER INLAND ASSOCIATED WITH CONVERGENCE AROUND
HIGH. HRRR SHOWING QUITE A FEW SHOWERS OVER SC THIS
AFTERNOON...REMAINING MAINLY WEST OF I95. DRIER AIR WILL CONTINUE
TO PUSH INLAND WITH PROGRESSION OF SEA BREEZE. MODELS SHOW PCP
WATER VALUES UP CLOSE TO 1.7 INCHES INLAND THIS AFTN DROPPING DOWN
TO 1.2 INCHES BY LATE THIS EVENING. THEREFORE CLOUDS AND ISOLATED
SHOWERS THAT DEVELOP ALONG THIS BOUNDARY AS IT PROGRESSES
INLAND...WILL LEAVE MOST OF THE COAST CLEAR BY THIS AFTERNOON AND
INLAND AREAS BY LATE THIS EVENING.
TEMPS BETWEEN 85 AND 90 MOST PLACES WILL DROP SLOWLY THROUGH THE
EVENING. EXPECT OVERNIGHT LOWS TO BE BETWEEN 70 AN 75 WITH
SLIGHTLY WARMER TEMPS RIGHT ALONG THE COAST WHERE WARMER OCEAN
WATERS WILL KEEP THEM HIGHER. MOISTURE PROFILES SHOW SOME UPPER
LEVEL MOISTURE INCREASING TONIGHT AS THE UPPER TROUGH CURRENTLY
OVER SOUTHERN ILLINOIS LIFTS NORTHEAST PRODUCING A MORE NW FLOW IN
THE UPPER ATMOSPHERE. THIS WILL PRODUCE SOME CIRRUS BY MORNING BUT
OVERALL EXPECT MAINLY CLEAR SKIES. HAVE INCLUDED MENTION OF PATCHY
FOG BUT LEFT OUT ANY SHOWERS...ALTHOUGH CAN NOT RULE OUT AN
ISOLATED SHOWER OR TWO MOVING ON SHORE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE WESTERN ATLANTIC RIDGING BOTH SFC AND
ALOFT AND HAVING PROVIDED THE TROPICAL WX TYPE CONDITIONS DURING
THIS EXTENDED JULY 4TH WEEKEND...WILL WEAKEN ACROSS THE AREA
MONDAY INTO TUESDAY. THIS A RESULT OF THE SLIGHT PROGRESSION OF WX
FEATURES BOTH ALOFT AND AT THE SFC. THE UPPER RIDGE AXIS AND THE
CENTER OF THE ASSOCIATED WESTERN ATLANTIC SFC HIGH...AKA BERMUDA
HIGH...IS PROGGED BY THE MODELS TO SLIDE FURTHER OFFSHORE FROM
THE CAROLINA COASTS. THE ORIENTED LOWER TO MID MISSISSIPPI AND
OHIO RIVER UPPER TROF IS PROGGED TO FLATTEN SOME AS THE MAIN VORT
FINALLY PROGRESSES NE TO E...STAYING WELL NORTH OF THE FA DURING
THIS SHORT TERM PERIOD. WHAT FINALLY ENDS UP IS A LOW AMPLITUDE
UPPER TROUGHINESS ALONG THE SPINE OF THE APPALACHIANS FROM VA
SOUTHWESTWARD...AND LEE SIDE SFC TROFFINESS ACROSS THE CAROLINAS.
THE SFC RIDGE AXIS EXTENDING SW-W FROM THE OFFSHORE BERMUDA HIGH
WILL EVENTUALLY DROP SOUTH OF THE ILM CWA. THE TRUE ATLANTIC
TROPICAL ATM REGIME OF THE PAST SEVERAL DAYS WILL FINALLY COME
PARTIALLY TO AN END. WITH THE ADDITION OF CONVECTIVE FOCUS
MECHANISMS BESIDES THE SEA BREEZE FOR MON AND TUE AS WELL AS
BETTER INSTABILITY...POPS WILL SLOWLY INCREASE BUT REMAIN CAPPED
IN THE CHANCE CATEGORY. POPS WILL PEAK DURING THE AFTN/EARLY
EVENING AIDED BY THE DAYS HEATING. THE NOCTURNAL TROPICAL REGIME
TYPE CONVECTION OVER THE ATL WATERS OF THE PAST SEVERAL DAYS WILL
NO LONGER HAVE A STRAIGHT LINE SHOT TO THE IMMEDIATE COAST DURING
PRE-DAWN TUE...AND PRE-DAWN WED. HOWEVER BY PRE-DAWN WED...A SFC
TROF WILL HAVE REACHED THE ATLANTIC WATERS OFF THE SE U.S.
COAST...WHICH IS A REFLECTION FROM AN UPPER LOW THAT TRAVERSES THE
BAHAMAS MON AND PARTIALLY ACROSS FLORIDA TUE. MOISTURE ASSOCIATED
WITH THIS FEATURE COULD REACH THE ATL WATERS AND PUSH PARTIALLY ON
SHORE LATE ON THE PRE-DAWN WED HOURS. THIS WILL NEED TO BE
MONITORED. FOR MAX TEMPS MON AND TUE...GUIDANCE REMAINS RATHER
CLUSTERED WITH MID 80S ALONG THE IMMEDIATE COAST...UPPER 80S TO
AROUND 90 FROM THE COAST TO THE I-95 CORRIDOR...AND LOWER 90S WEST
OF THE I-95 CORRIDOR. FOR MIN TEMPS BOTH MORNINGS...A 70 TO 75
RANGE...THE EXCEPTION WILL BE THE IMMEDIATE COAST WHERE MID 70S TO
RULE BOTH DAYS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 PM SUNDAY...WHILE THE BEGINNING OF THE PERIOD WILL
CONTINUE WITH WARM SUMMER CONDITIONS AND ONLY ISOLATED
CONVECTION...A PATTERN REGIME CHANGE WILL OCCUR BY THE END OF THE
WEEK...AND A RENEWED WET PERIOD IS BECOMING MORE LIKELY FOR THE WKND.
BERMUDA HIGH AT THE SURFACE AND FLAT RIDGING ALOFT WILL CREATE ONE
LAST DAY OF TEMPS AT TO ABOVE CLIMO WITH A LOT OF SUNSHINE AND
LITTLE CONVECTION. THEREAFTER...UPPER TROUGHING BEGINS TO BUILD DOWN
FROM THE NORTHWEST AND ACROSS THE EASTERN CONUS. WHILE THE COLD
FRONT ASSOCIATED WITH THIS UPPER TROUGH WILL LIKELY GET HELD UP AND
WASH OUT JUST NORTH OF THE LOCAL AREA...DECREASING HEIGHTS ALOFT
WILL STEEPEN LAPSE RATES...LEADING TO INCREASING CONVECTIVE
POTENTIAL. AT THE SAME TIME...TROPICAL WAVE WHICH HAS BEEN PROGGED
TO MOVE BENEATH THE BERMUDA HIGH AND INTO FLORIDA WILL FEED SOME OF
ITS MOISTURE INTO THE CAROLINAS BEGINNING FRIDAY. THIS ENHANCED
MOISTURE...PWATS RISING TO OVER 2 INCHES...COMBINED WITH THE STEEPER
LR`S IN THE MID-LEVELS WILL SUPPORT EVEN MORE SIGNIFICANT CONVECTION
ON FRIDAY. DO NOT ANTICIPATE A SEVERE THREAT ATTM...BUT HEAVY RAIN
WILL BE POSSIBLE. MAX TEMPS WILL REMAIN AROUND CLIMO THROUGH THE END
OF THE WEEK...WITH LOWS HOVERING A FEW DEGREES ABOVE.
WEATHER COULD DETERIORATE MORE CONSIDERABLY FOR NEXT WEEKEND. 5H
TROUGH CLOSES OFF IN RESPONSE TO STRONG AMPLIFICATION OF THE
FLOW...AND BLOCKING RIDGE ACROSS THE WESTERN ATLANTIC. THIS FORCES
THE CLOSED LOW TO RETROGRADE TO THE WEST...WITH DEEP SOUTHERLY FLOW
ONCE AGAIN DEVELOPING ACROSS THE SOUTHEAST. IN A PATTERN EERILY
REMINISCENT OF THE END OF JUNE...CLOSED LOW ACROSS THE TN VLY WITH
BLOCKING HIGH OVER THE OCEAN WILL DRIVE TROPICAL MOISTURE INTO THE
REGION AND A WET PERIOD AGAIN LOOKS TO BE IN STORE. FORTUNATELY...AT
LEAST FOR D6/D7...IT DOES NOT LOOK QUITE AS ROBUST AS THE PATTERN WE
SAW TO CLOSE OUT JUNE...BUT AN EXTENDED PERIOD OF UNSETTLED
WEATHER LOOKS LIKELY FOR NEXT WKND.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...HIGH PRESSURE OFFSHORE WILL CONTINUE TO GIVE US SOUTH
SOUTHEAST FLOW THROUGH THE PERIOD. NO FOG EXPECTED WITH WINDS AT
THE BOUNDARY LAYER 15+ KTS. MONDAY...MODELS INDICATE HIGH LEVEL
MOISTURE RETURNING...WITH BROKEN CIRRUS EXPECTED ALL DAY. WINDS WILL
BE A BIT MORE SOUTHWESTERLY.
EXTENDED OUTLOOK...EARLY MORNING IFR/MVFR CIGS/VSBYS POSSIBLE
THROUGH THE EXTENDED PERIOD. INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS THURSDAY AND FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...SOUTHERLY RETURN FLOW 10 TO 15 KTS WILL
PERSIST ACROSS THE WATERS AROUND THE PERIPHERY OF BERMUDA HIGH
PRESSURE. THE WINDS WILL ACTUALLY VEER EVER SO SLIGHTLY FROM S-SE
TO S-SW BY MORNING REMAINING AROUND 10 KTS FOR THE MOST PART. AN 8
SECOND SE SWELL WILL CONTINUE TO MIX WITH LOCALLY GENERATED WIND
WAVES TO PRODUCE TOTAL SEAS OF 2 TO 3 FT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE WESTERN ATLANTIC HIGH...AKA BERMUDA
HIGH...WILL REMAIN THE PRIMARY INFLUENCE OF THE WINDS ACROSS THE
LOCAL WATERS. THE DEVELOPMENT OF THE LEE-SIDE TROF ACROSS THE
WESTERN AND CENTRAL CAROLINAS...AND THE SFC RIDGE AXIS THAT
EXTENDS SW-W FROM THE CENTER OF THE BERMUDA HIGH OFFSHORE...IS
PROGGED TO DROP SOUTH OF THE LOCAL WATERS THIS TIME PERIOD.
THEREFORE...A SW WIND DIRECTION WILL EVENTUALLY BECOME THE
DOMINANT WIND DIRECTION. THE DAILY SEA BREEZE WILL TEMPORARILY
BACK WINDS TO A MORE SOUTHERLY DIRECTION EACH AFTN/EVENING. WITH
THE CENTER OF THE HIGH FURTHER AWAY AND OFFSHORE FROM THE ILM
WATERS...THE SFC PG WILL SLIGHTLY TIGHTEN. BASICALLY LOOKING AT
WIND SPEEDS IN THE 10 TO 15 KT RANGE...WITH THE SEA BREEZE ADDING
5 KT OF SPEED NEARSHORE EACH AFTN AND EVENING...THUS REACHING 15
TO POSSIBLY 20 KT. SIGNIFICANT SEAS WILL HOVER AROUND THE 3 FOOT
HEIGHT THRU-OUT THE SHORT TERM.
THERE WILL BE LESS OF AN INFLUENCE FROM THE 6 TO 8 SECOND PERIOD
SE SWELL DUE TO FETCH LIMITATIONS...BUT AN INCREASED INFLUENCE
FROM THE 3 TO 5 SECOND PERIOD WIND DRIVEN WAVES. THIS WILL FINALLY
BEGIN TO LOWER THE RIP CURRENT RISK...RELATIVELY SPEAKING. IN
ADDITION...BOATERS NAVIGATING TO AND FROM THE ATL THRU AREA INLETS
WILL ALSO IMPROVE...SOME ESPECIALLY WHEN TRAVERSING THESE WATERS
DURING AN OUT-GOING TIDE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...BERMUDA HIGH OFFSHORE PERSISTS DURING THE
EXTENDED...KEEPING SW WINDS ONGOING ACROSS THE WATERS. WHILE THE
GRADIENT ON THE WESTERN SIDE OF THIS RIDGE REMAINS RELATIVELY
WEAK...IT DOES SLOWLY STRENGTHEN LATE IN THE WEEK IN RESPONSE TO A
COLD FRONT DRIFTING SLOWLY TOWARDS THE AREA. WHILE THIS FRONT WILL
LIKELY NOT MAKE IT TO THE WATERS...AND INSTEAD WASH OUT ACROSS THE
CENTRAL CAROLINAS FRIDAY...THE PINCHING GRADIENT WILL HELP WINDS
INCREASE FROM 10-15 KTS WEDNESDAY TO 15-20 KTS THURSDAY AND
FRIDAY. THE SE SWELL WILL SLOWLY DECAY THROUGH THE PERIOD...BUT SW
WIND WAVES WILL GRADUALLY INCREASE IN AMPLITUDE. SEAS WILL BUILD
FROM 2-3 FT WEDNESDAY...TO AS MUCH AS 4-5 FT LATE THURSDAY INTO
FRIDAY...AND A SCEC MAY BE REQUIRED FOR A PORTION OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR SCZ054.
NC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ106-
108-110.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...RGZ
SHORT TERM...DCH
LONG TERM...JDW
AVIATION...RGZ/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WEAKENING UPPER LEVEL LOW WILL PROGRESS EAST ACROSS THE MID-
ATLANTIC TONIGHT. CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE EASTERN
UNITED STATES THROUGH MID WEEK...WITH AN UNSEASONABLY DEEP UPPER
LEVEL TROUGH DIGGING SOUTHEAST IN THE MID-ATLANTIC BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM SUNDAY...
SOME VERY LIGHT SHOWERS REMAIN IN THE NORTHEAST PIEDMONT...BUT THE
STRONGER STORMS AND BETTER COVERAGE REMAINS JUST WEST OF THE TRIAD.
AS WITH YESTERDAY...THE HRRR HIGH RES CAM IS DOING THE BEST AT
SIMULATING THE CURRENT SHOWER ACTIVITY...ALTHOUGH THE TIMING MAY BE
A BIT OFF. HIGH PRESSURE REMAINS OFF THE CAROLINA COAST...WITH THE
LOW WEST OF THE APPALACHIANS OVER IL/IN. LOW LEVEL MOISTURE IS
ADVECTING INTO WESTERN NC OFF THE GULF AHEAD OF THE LOW PRESSURE
SYSTEM. AS THE UPPER LEVEL LOW CONTINUES TO MOVE EASTWARD INTO PA
TONIGHT...SMALL AMPLITUDE SHORTWAVES WILL TRACK NORTHEAST ACROSS
WESTERN NC/VA. IN ADDITION TO THE SHORTWAVES...MOISTURE CONVERGENCE
ALONG THE PIEDMONT TROUGH ARE THE LIKELY DRIVING MECHANISMS FOR THE
CONVECTION MOVING INTO THE TRIAD. CURRENT ANALYZED MLCAPE VALUES
RANGE FROM 1500-2000 J/KC ACROSS CENTRAL NC...WITH THE BEST CAPE
DISPLACED FROM THE BEST SHEAR (OVER THE MTNS). BEST CHANCES FOR
SHOWERS/STORMS WILL REMAIN IN THE WEST THROUGH TONIGHT. THERE IS THE
POTENTIAL FOR SOME STORMS TO PRODUCE DAMAGING WINDS THIS AFT/EVE...
MAINLY IN AND AROUND THE TRIAD WHERE THE DCAPE IS ANALYZED AROUND
1000 J/KG AND 0-6 KM SHEAR VALUES AROUND 30 KTS. LOWS TONIGHT
SIMILAR TO PREVIOUS NIGHTS IN THE LOWER 70S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 240 PM SUNDAY...
AS THE UPPER LEVEL LOW MAKES ITS WAY ACROSS PA AND INTO NEW ENGLAND
MONDAY AND MONDAY NIGHT...THE ASSOCIATED TROUGH WILL MOVE INTO
CENTRAL NC...THUS DAMPENING THE HIGH AND PUSHING THE RIDGE AXIS
SOUTH AND EAST. THE MAIN SHOWER ACTIVITY WILL SHIFT SLOWLY EASTWARD
THROUGH THE DAY AND INTO THE EVENING MONDAY AS ADDITIONAL SHORTWAVE
DISTURBANCES MOVE OVER THE AREA. HIGHEST PRECIP CHANCES COINCIDE
WITH PEAK HEATING...AND WILL DECREASE SUBSTANTIALLY AFTER SUNSET.
HIGH TEMPS WILL BE SIMILAR TO TODAY...MID 80S NW INCREASING TO NEAR
90 IN THE EAST. OVERNIGHT LOWS WILL AGAIN BE SIMILAR TO PREVIOUS
NIGHTS...MAINLY IN THE LOW 70S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 230 PM SUNDAY...
FOR TUESDAY/TUESDAY NIGHT: VERY WEAK MID LEVEL TROUGH AXIS HOLDS
OVER THE EAST COAST WHILE A SUBTLE SURFACE TROUGH HOLDS OVER THE NC
PIEDMONT. ABOVE-NORMAL DEEP MOISTURE PERSISTS ESPECIALLY SOUTH AND
EAST OF THE TROUGH WITH PW VALUES RANGING FROM 1.7-2.0 INCHES FROM
NW TO SE OVER CENTRAL NC. THE WEAK WIND FIELD (PROJECTED WINDS NO
GREATER THAN 15 KTS BELOW 400 MB) THROUGHOUT THE MOIST COLUMN
COMBINED WITH DAYTIME DESTABILIZATION (MLCAPE PEAKING AT 1200-2000
J/KG) SUGGEST SCATTERED STORMS DEVELOPING IN THE AFTERNOON WITH SLOW
MOVEMENT AND THE POTENTIAL TO DUMP SOME HEAVY RAIN... GIVEN THE
LCL-TO-0C LAYER DEPTH APPROACHING 3.8-4 KM. THE GFS/NAM/ECMWF
GENERALLY FAVOR BETTER COVERAGE OVER THE SOUTHEAST CWA IN
CONJUNCTION WITH THE GREATEST MOISTURE AND INSTABILITY... SO WILL
EDGE POPS HIGHER THERE THAN IN THE REST OF THE CWA. SHOWERS/STORMS
SHOULD FOLLOW A TYPICAL DIURNAL PATTERN OF TAPERING DOWN AFTER
NIGHTFALL... ALTHOUGH WITH ANOMALOUSLY HIGH MOISTURE CONTINUING TO
POOL OVER CENTRAL NC... A FEW MEANDERING SHOWERS AND ISOLATED STORMS
MAY PERSIST OVERNIGHT. HIGHS 86-90. LOWS 70-73.
FOR WEDNESDAY/WEDNESDAY NIGHT: THIS LOOKS TO BE THE TIME FRAME WITH
A RELATIVE MINIMUM IN RAIN CHANCES... BUT CERTAINLY NOT ZERO
CONSIDERING THE STILL-HIGH PW VALUES NEAR 2.0 INCHES. THE WESTERLIES
TAKE A DIP INTO THE GREAT LAKES AS THE TROUGH BEGINS TO DIG TO OUR
NORTHWEST... RESULTING A SLIGHT DOWNSTREAM REBOUNDING IN HEIGHTS
OVER NC. GFS FORECAST SOUNDINGS SHOW A PERIOD OF MID LEVEL DRYING
BETWEEN 800 AND 500 MB MAINLY IN THE EASTERN CWA... WHERE BOTH THE
GFS AND ECMWF SHOW FAIRLY LOW QPF. WILL LEAVE IN CHANCE POPS...
SKEWED HIGHER IN THE TRIAD AND LOWER IN THE SOUTHEAST... FOCUSED ON
THE AFTERNOON/EVENING. HIGHS 87-91 AS THICKNESSES STAY NEAR
CLIMATOLOGY. THE DEEPENING MID LEVEL TROUGH TO OUR WEST RESULTS IN
AN UPTICK IN MID LEVEL WINDS OVER NW NC WEDNESDAY NIGHT... AND WITH
MOISTURE REMAINING HIGH OR EVEN INCREASING A BIT OVER OUR NW CWA
OVERNIGHT... WILL HOLD ONTO CHANCE POPS HERE WITH JUST A SLIGHT
CHANCE ELSEWHERE. LOWS 70-74.
FOR THURSDAY THROUGH SUNDAY: CONFIDENCE IS IMPROVING THAT THIS WILL
BE A FAIRLY WET PERIOD. THE LONGWAVE TROUGH DIGS FURTHER THROUGH THE
EASTERN GREAT LAKES AND OH VALLEY ON THURSDAY AS THE SURFACE COLD
FRONT MOVES IN FROM THE NW... AND THE INCREASING DYNAMICS AND DEEP
MOISTURE FLUX OVER NC WILL BRING INCREASING SHOWER/STORM COVERAGE
FROM NW TO SE AS WE HEAD THROUGH THURSDAY AFTERNOON/NIGHT. THE
MODELS CLOSE OFF A LOW TO OUR NORTHWEST... OVER WV/ERN KY/ERN TN...
ON FRIDAY BEFORE DROPPING IT DOWN TO NRN GA/AL/MS OVER THE WEEKEND.
SUCH A CLOSED LOW THAT FAR SOUTH IS HIGHLY UNUSUAL FOR THIS TIME OF
YEAR (GEFS FORECAST 500 MB HEIGHTS OVER 2 STANDARD DEVIATIONS BELOW
NORMAL OVER THE SOUTHEAST STATES)... SO IT IS SURPRISING HOW GOOD
THE AGREEMENT IS BETWEEN THE OP GFS (12Z/07) AND ECMWF (00Z/07).
WITH THE LOSS OF EASTWARD PUSH... THE SURFACE FRONT IS LIKELY TO
STALL OUT OVER CENTRAL NC... AND WITH A STRENGTHENING AND DEEPENING
SOUTHERLY FLOW ALLOWING 2.0+ INCH PW VALUES TO STREAK OVER CENTRAL
NC FROM THURSDAY NIGHT THROUGH AT LEAST SATURDAY... WITH SOME DRYING
POSSIBLE SUNDAY AS A LARGE AND STRONG MID LEVEL CYCLONE BUILDS FROM
OFF THE CANADIAN MARITIMES SOUTHWESTWARD INTO NC. WILL KEEP HIGH
RAIN CHANCES FOR THURSDAY NIGHT THROUGH SATURDAY... A BIT HIGHER IN
THE AFTERNOON/EVENING BUT NOT YIELDING MUCH AT NIGHT... DROPPING
BACK TOWARD CLIMATOLOGICAL POPS ON SUNDAY. EXPECT QUITE A BIT OF
CLOUDINESS THROUGH THIS PERIOD WITH HUMID CONDITIONS REDUCING THE
DIURNAL TEMP RANGE. LOWS AROUND 70-75 AND HIGHS IN THE LOW-MID 80S.
-GIH
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 125 PM SUNDAY...
24-HR TAF PERIOD:
CIGS HAVE BEEN BORDERLINE VFR/MVFR ALL DAY...BOUNCING BACK AND FORTH
BETWEEN THE TWO...AND WILL LIKELY CONTINUE TO BE SO THROUGH MONDAY
MORNING. LIGHT SHOWERS ARE OCCURRING AROUND KRDU...WITH HEAVIER
SHOWERS AND POSSIBLE THUNDER MOVING INTO THE TRIAD (KINT AND KGSO)
THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. BEST CHANCE FOR LOW-END
MVFR CIGS AT KINT AND KGSO DURING THE PRE-DAWN HOURS MONDAY...WITH
THE POTENTIAL FOR A PERIOD OF BORDERLINE VFR/MVFR CIGS ELSEWHERE...
ALTHOUGH CONFIDENCE IS LOW GIVEN THE DIFFERENCES IN MODEL GUIDANCE
AT THIS TIME. THERE IS THE CHANCE FOR SHOWERS TO REDEVELOP ACROSS
THE AREA MONDAY AFTERNOON/EVENING...BUT WILL LEAVE MENTION OUT OF
TAFS FOR NOW. -KC
LOOKING AHEAD:
AVIATION CONDITIONS THROUGH MID/LATE WEEK WILL BE CHARACTERIZED BY
AN ABOVE NORMAL CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY
(PRIMARILY AFTERNOON AND EVENING HOURS) IN ASSOCIATION WITH CYCLONIC
FLOW ALOFT AND AN ABOVE NORMAL CHANCE FOR MVFR/IFR STRATUS OR FOG
EACH MORNING (PRIMARILY 07-13Z) IN ASSOCIATION WITH A PERSISTENT
MOIST SOUTHERLY RETURN FLOW. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC
SHORT TERM...KC
LONG TERM...HARTFIELD
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WEAKENING UPPER LEVEL LOW WILL PROGRESS EAST ACROSS THE MID-
ATLANTIC TONIGHT. CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE EASTERN
UNITED STATES THROUGH MID WEEK...WITH AN UNSEASONABLY DEEP UPPER
LEVEL TROUGH DIGGING SOUTHEAST IN THE MID-ATLANTIC BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM SUNDAY...
SOME VERY LIGHT SHOWERS HAVE DEVELOPED OVER THE SOUTHERN PIEDMONT
AND SANDHILLS THIS MORNING. AS WITH YESTERDAY...THE HRRR HIGH RES
CAM IS DOING A GOOD JOB SIMULATING THE CURRENT SHOWER ACTIVITY. THE
LATEST RUN OF THE HRRR SHOWS AN INCREASE IN SHOWER COVERAGE...MAINLY
IN THE NORTHEAST PIEDMONT AND SANDHILLS THROUGH THIS AFTERNOON...
WITH THE MORE WIDESPREAD CONVECTION MOVING INTO THE NORTHWEST
PIEDMONT LATE THIS AFT/EVE. 12Z UPPER AIR ANALYSES SHOW THE LOW WEST
OF THE APPALACHIANS OVER IL/IN...WITH HIGH PRESSURE OFF THE CAROLINA
COAST. WHILE CENTRAL NC IS RELATIVELY DRY...LOW LEVEL MOISTURE IS
ADVECTING IN OFF THE GULF AHEAD OF THE LOW PRESSURE SYSTEM. AS THE
UPPER LEVEL LOW MOVES EASTWARD TODAY SO WILL THE LOW/MID LEVEL
MOISTURE AND SHOWERS/STORMS...CURRENTLY OVER THE MOUNTAINS. -KC
PRECIPITATION CHANCES:
SW FLOW ALOFT WILL STRENGTHEN FROM THE WEST TODAY...WITH AN
INCREASING POTENTIAL FOR SMALL AMPLITUDE SHORTWAVES TRACKING
NORTHEAST ACROSS WESTERN NC/VA THIS AFT/EVE...FOLLOWED BY ADDITIONAL
DPVA WITHIN INCREASINGLY CYCLONIC FLOW ALOFT AS THE UPPER LEVEL LOW
TRACKS INTO WESTERN PA BETWEEN 00-06Z TONIGHT. SHALLOW CONVERGENCE
IN VICINITY OF A DEVELOPING PIEDMONT SFC TROUGH ASSOCIATED WITH
SUBTLE HEIGHT FALLS IN ADVANCE OF THE UPPER LEVEL WAVE APPROACHING
THE REGION THIS AFT/EVE WILL SERVE AS A POTENTIAL FOCUS FOR DIURNAL
CONVECTION THIS AFTERNOON...FOLLOWED BY SOMEWHAT DEEPER CONVERGENCE
TONIGHT AS THE LOW-LEVEL TROUGH SHARPENS IN RESPONSE TO STRONGER
HEIGHT FALLS /CYCLONIC FLOW ALOFT/ OVER THE MID-ATLANTIC. SEASONAL
BOUNDARY LAYER MOISTURE/DESTABILIZATION CAN BE EXPECTED AGAIN THIS
AFTERNOON...WITH MLCAPE VALUES GENERALLY IN THE 1000-2000 J/KG RANGE
ACROSS CENTRAL NC...THOUGH A WEST-EAST MID-LEVEL MOISTURE GRADIENT
WILL PERSIST WITH DEEPER MOISTURE ACROSS THE FOOTHILLS/WESTERN
PIEDMONT AND A DRIER AIRMASS ALOFT IN THE COASTAL PLAIN. WITH THE
ABOVE IN MIND...EXPECT THE BEST CHANCE FOR CONVECTION THIS AFTERNOON
AND EARLY EVENING WEST OF THE HWY 1 CORRIDOR IN VICINITY OF THE
PIEDMONT SFC TROUGH AND IN CLOSER PROXIMITY TO SMALL AMPLITUDE
SHORTWAVES/DEEPER MOISTURE IN STRENGTHENING SW FLOW ALOFT. WILL
INDICATE PRECIP CHANCES RANGING FROM 20% EAST OF I-95 TO 50-60% IN
THE FAR W/NW PIEDMONT. CONVECTION SHOULD PERSIST INTO TONIGHT ACROSS
THE NORTHERN AND WESTERN PIEDMONT AS BETTER DPVA /STRONGER CYCLONIC
FLOW ALOFT/ PROGRESSES INTO THE MID-ATLANTIC.
TEMPERATURES:
EXPECT HIGHS TODAY SIMILAR TO PREVIOUS DAYS WITH VERY SIMILAR
REASONING...THOUGH PERHAPS SLIGHTLY WARMER GIVEN A MORE
SOUTHWESTERLY LOW-LEVEL FLOW...ESP. ALONG AND EAST OF THE HWY 1
CORRIDOR...WITH HIGHS RANGING FROM THE MID 80S FAR NW PIEDMONT TO
UPPER 80S AND LOWER 90S ELSEWHERE. LOWS TONIGHT SIMILAR TO PREVIOUS
NIGHTS IN THE LOWER 70S.
SEVERE THREAT:
GIVEN DEEP LAYER SHEAR IN THE 25-35 KT RANGE ACROSS THE N/NW
PIEDMONT IN THE PRESENCE OF MODERATE INSTABILITY (1000-2000 J/KG
MLCAPE) AND DCAPE VALUES PROGGED AS HIGH AS 1000-1500 J/KG THIS AFT
AND EARLY EVE...ANTICIPATE A POTENTIAL FOR DAMAGING WINDS...
PRIMARILY WEST AND NW OF THE TRIANGLE. -VINCENT
&&
.SHORT TERM /MONDAY/...
AS OF 325 AM SUNDAY...
ALTHOUGH THE AFOREMENTIONED UPPER LEVEL WAVE WILL TRACK EAST THROUGH
THE MID-ATLANTIC EARLY MONDAY MORNING...CYCLONIC FLOW ALOFT AND
LOW-LEVEL TROUGHING WILL PERSIST ACROSS THE AREA MONDAY
AFT/EVE...WITH ADDITIONAL SHORTWAVE ENERGY ANTICIPATED TO DIG
SOUTHEAST INTO NC/VA IN VICINITY OF PEAK HEATING. AS A RESULT...
EXPECT ABOVE NORMAL CHANCES FOR CONVECTION...PRIMARILY DURING THE
AFTERNOON AND EVENING HOURS...WITH HIGHS SIMILAR TO PREVIOUS DAYS...
IN THE MID/UPPER 80S TO NEAR 90F. -VINCENT
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 230 PM SUNDAY...
FOR TUESDAY/TUESDAY NIGHT: VERY WEAK MID LEVEL TROUGH AXIS HOLDS
OVER THE EAST COAST WHILE A SUBTLE SURFACE TROUGH HOLDS OVER THE NC
PIEDMONT. ABOVE-NORMAL DEEP MOISTURE PERSISTS ESPECIALLY SOUTH AND
EAST OF THE TROUGH WITH PW VALUES RANGING FROM 1.7-2.0 INCHES FROM
NW TO SE OVER CENTRAL NC. THE WEAK WIND FIELD (PROJECTED WINDS NO
GREATER THAN 15 KTS BELOW 400 MB) THROUGHOUT THE MOIST COLUMN
COMBINED WITH DAYTIME DESTABILIZATION (MLCAPE PEAKING AT 1200-2000
J/KG) SUGGEST SCATTERED STORMS DEVELOPING IN THE AFTERNOON WITH SLOW
MOVEMENT AND THE POTENTIAL TO DUMP SOME HEAVY RAIN... GIVEN THE
LCL-TO-0C LAYER DEPTH APPROACHING 3.8-4 KM. THE GFS/NAM/ECMWF
GENERALLY FAVOR BETTER COVERAGE OVER THE SOUTHEAST CWA IN
CONJUNCTION WITH THE GREATEST MOISTURE AND INSTABILITY... SO WILL
EDGE POPS HIGHER THERE THAN IN THE REST OF THE CWA. SHOWERS/STORMS
SHOULD FOLLOW A TYPICAL DIURNAL PATTERN OF TAPERING DOWN AFTER
NIGHTFALL... ALTHOUGH WITH ANOMALOUSLY HIGH MOISTURE CONTINUING TO
POOL OVER CENTRAL NC... A FEW MEANDERING SHOWERS AND ISOLATED STORMS
MAY PERSIST OVERNIGHT. HIGHS 86-90. LOWS 70-73.
FOR WEDNESDAY/WEDNESDAY NIGHT: THIS LOOKS TO BE THE TIME FRAME WITH
A RELATIVE MINIMUM IN RAIN CHANCES... BUT CERTAINLY NOT ZERO
CONSIDERING THE STILL-HIGH PW VALUES NEAR 2.0 INCHES. THE WESTERLIES
TAKE A DIP INTO THE GREAT LAKES AS THE TROUGH BEGINS TO DIG TO OUR
NORTHWEST... RESULTING A SLIGHT DOWNSTREAM REBOUNDING IN HEIGHTS
OVER NC. GFS FORECAST SOUNDINGS SHOW A PERIOD OF MID LEVEL DRYING
BETWEEN 800 AND 500 MB MAINLY IN THE EASTERN CWA... WHERE BOTH THE
GFS AND ECMWF SHOW FAIRLY LOW QPF. WILL LEAVE IN CHANCE POPS...
SKEWED HIGHER IN THE TRIAD AND LOWER IN THE SOUTHEAST... FOCUSED ON
THE AFTERNOON/EVENING. HIGHS 87-91 AS THICKNESSES STAY NEAR
CLIMATOLOGY. THE DEEPENING MID LEVEL TROUGH TO OUR WEST RESULTS IN
AN UPTICK IN MID LEVEL WINDS OVER NW NC WEDNESDAY NIGHT... AND WITH
MOISTURE REMAINING HIGH OR EVEN INCREASING A BIT OVER OUR NW CWA
OVERNIGHT... WILL HOLD ONTO CHANCE POPS HERE WITH JUST A SLIGHT
CHANCE ELSEWHERE. LOWS 70-74.
FOR THURSDAY THROUGH SUNDAY: CONFIDENCE IS IMPROVING THAT THIS WILL
BE A FAIRLY WET PERIOD. THE LONGWAVE TROUGH DIGS FURTHER THROUGH THE
EASTERN GREAT LAKES AND OH VALLEY ON THURSDAY AS THE SURFACE COLD
FRONT MOVES IN FROM THE NW... AND THE INCREASING DYNAMICS AND DEEP
MOISTURE FLUX OVER NC WILL BRING INCREASING SHOWER/STORM COVERAGE
FROM NW TO SE AS WE HEAD THROUGH THURSDAY AFTERNOON/NIGHT. THE
MODELS CLOSE OFF A LOW TO OUR NORTHWEST... OVER WV/ERN KY/ERN TN...
ON FRIDAY BEFORE DROPPING IT DOWN TO NRN GA/AL/MS OVER THE WEEKEND.
SUCH A CLOSED LOW THAT FAR SOUTH IS HIGHLY UNUSUAL FOR THIS TIME OF
YEAR (GEFS FORECAST 500 MB HEIGHTS OVER 2 STANDARD DEVIATIONS BELOW
NORMAL OVER THE SOUTHEAST STATES)... SO IT IS SURPRISING HOW GOOD
THE AGREEMENT IS BETWEEN THE OP GFS (12Z/07) AND ECMWF (00Z/07).
WITH THE LOSS OF EASTWARD PUSH... THE SURFACE FRONT IS LIKELY TO
STALL OUT OVER CENTRAL NC... AND WITH A STRENGTHENING AND DEEPENING
SOUTHERLY FLOW ALLOWING 2.0+ INCH PW VALUES TO STREAK OVER CENTRAL
NC FROM THURSDAY NIGHT THROUGH AT LEAST SATURDAY... WITH SOME DRYING
POSSIBLE SUNDAY AS A LARGE AND STRONG MID LEVEL CYCLONE BUILDS FROM
OFF THE CANADIAN MARITIMES SOUTHWESTWARD INTO NC. WILL KEEP HIGH
RAIN CHANCES FOR THURSDAY NIGHT THROUGH SATURDAY... A BIT HIGHER IN
THE AFTERNOON/EVENING BUT NOT YIELDING MUCH AT NIGHT... DROPPING
BACK TOWARD CLIMATOLOGICAL POPS ON SUNDAY. EXPECT QUITE A BIT OF
CLOUDINESS THROUGH THIS PERIOD WITH HUMID CONDITIONS REDUCING THE
DIURNAL TEMP RANGE. LOWS AROUND 70-75 AND HIGHS IN THE LOW-MID 80S.
-GIH
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 125 PM SUNDAY...
24-HR TAF PERIOD:
CIGS HAVE BEEN BORDERLINE VFR/MVFR ALL DAY...BOUNCING BACK AND FORTH
BETWEEN THE TWO...AND WILL LIKELY CONTINUE TO BE SO THROUGH MONDAY
MORNING. LIGHT SHOWERS ARE OCCURRING AROUND KRDU...WITH HEAVIER
SHOWERS AND POSSIBLE THUNDER MOVING INTO THE TRIAD (KINT AND KGSO)
THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. BEST CHANCE FOR LOW-END
MVFR CIGS AT KINT AND KGSO DURING THE PRE-DAWN HOURS MONDAY...WITH
THE POTENTIAL FOR A PERIOD OF BORDERLINE VFR/MVFR CIGS ELSEWHERE...
ALTHOUGH CONFIDENCE IS LOW GIVEN THE DIFFERENCES IN MODEL GUIDANCE
AT THIS TIME. THERE IS THE CHANCE FOR SHOWERS TO REDEVELOP ACROSS
THE AREA MONDAY AFTERNOON/EVENING...BUT WILL LEAVE MENTION OUT OF
TAFS FOR NOW. -KC
LOOKING AHEAD:
AVIATION CONDITIONS THROUGH MID/LATE WEEK WILL BE CHARACTERIZED BY
AN ABOVE NORMAL CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY
(PRIMARILY AFTERNOON AND EVENING HOURS) IN ASSOCIATION WITH CYCLONIC
FLOW ALOFT AND AN ABOVE NORMAL CHANCE FOR MVFR/IFR STRATUS OR FOG
EACH MORNING (PRIMARILY 07-13Z) IN ASSOCIATION WITH A PERSISTENT
MOIST SOUTHERLY RETURN FLOW. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...HARTFIELD
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
202 PM EDT SUN JUL 7 2013
.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL BRING DEEP BLUE SKIES TO THE EASTERN
CAROLINAS INTO MONDAY. THE BERMUDA HIGH WILL SLIDE FURTHER
OFFSHORE DURING THE WEEK ALLOWING A COLD FRONT TO SLOWLY APPROACH
FROM THE NORTHWEST. TYPICAL SUMMERTIME WEATHER WITH DAILY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL OCCUR
THROUGHOUT THE UPCOMING WEEK. STORM COVERAGE WILL INCREASE LATE IN
THE WEEK AS THE COLD FRONT MOVES CLOSER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM SUNDAY...HIGH PRESSURE RIDGING INTO COASTAL CAROLINAS
FROM THE ATLANTIC WILL SHIFT SLIGHTLY EAST THROUGH TODAY. THIS
WILL ALLOW THE WINDS TO SHIFT TO MORE OF A SOUTH DIRECTION INLAND
WITH MORE OF A SOUTHEAST FLOW ALONG THE COAST...ENHANCED WITH AFTN
SEA BREEZE. STILL SEEING PLENTY OF DRY AIR THROUGH THE MID TO
UPPER LEVELS THROUGH TODAY WITH MOISTURE CONFINED TO LOW LEVELS
BELOW 5K FT. FLOW HAS VEERED SLIGHTLY THROUGH THE LOW LEVELS
COMING AROUND TO SOUTHWEST ABOVE THE SURFACE UP THROUGH H85. THIS
HAS KEPT BEST CONVERGENCE AROUND THE RIDGE CLOSER TO THE COAST
WHICH IN TURN HAS KEPT CLOUDS AND SHOWERS FROM PUSHING WELL
INLAND. CONTINUE TO EXPECT GOOD DEAL OF SUNSHINE ACROSS MUCH OF THE
AREA WITH ONLY ISOLATED SHWRS/TSTMS MAINLY ALONG SEA BREEZE
BOUNDARY AND FURTHER INLAND ASSOCIATED WITH CONVERGENCE AROUND
HIGH. HRRR SHOWING QUITE A FEW SHOWERS OVER SC THIS
AFTERNOON...REMAINING MAINLY WEST OF I95. DRIER AIR WILL CONTINUE
TO PUSH INLAND WITH PROGRESSION OF SEA BREEZE. MODELS SHOW PCP
WATER VALUES UP CLOSE TO 1.7 INCHES INLAND THIS AFTN DROPPING DOWN
TO 1.2 INCHES BY LATE THIS EVENING. THEREFORE CLOUDS AND ISOLATED
SHOWERS THAT DEVELOP ALONG THIS BOUNDARY AS IT PROGRESSES
INLAND...WILL LEAVE MOST OF THE COAST CLEAR BY THIS AFTERNOON
AND INLAND AREAS BY LATE THIS EVENING.
TEMPS BETWEEN 85 AND 90 MOST PLACES WILL DROP SLOWLY THROUGH THE
EVENING. EXPECT OVERNIGHT LOWS TO BE BETWEEN 70 AN 75 WITH
SLIGHTLY WARMER TEMPS RIGHT ALONG THE COAST WHERE WARMER OCEAN
WATERS WILL KEEP THEM HIGHER. MOISTURE PROFILES SHOW SOME UPPER LEVEL
MOISTURE INCREASING TONIGHT AS THE UPPER TROUGH CURRENTLY OVER
SOUTHERN ILLINOIS LIFTS NORTHEAST PRODUCING A MORE NW FLOW IN THE
UPPER ATMOSPHERE. THIS WILL PRODUCE SOME CIRRUS BY MORNING BUT OVERALL
EXPECT MAINLY CLEAR SKIES. HAVE INCLUDED MENTION OF PATCHY FOG BUT
LEFT OUT ANY SHOWERS...ALTHOUGH CAN NOT RULE OUT AN ISOLATED
SHOWER OR TWO MOVING ON SHORE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH WILL REMAIN IN PLACE AT THE
SURFACE WHILE ALOFT THE MID LEVEL RIDGE RETREATS EAST. PASSAGE OF
SHORTWAVE TROUGH NORTH OF THE AREA MON INTO MON NIGHT DOES ALLOW
FOR WESTWARD EXPANSION OF 5H RIDGE TUE THOUGH IN A WEAKENED STATE.
WEAKENING MID LEVEL SUBSIDENCE ALONG WITH INCREASING MID LEVEL
MOISTURE LEADS TO INCREASED COVERAGE OF SHOWERS AND THUNDERSTORMS
DURING THE PERIOD. MON DEEPER DRY AIR NEAR THE COAST WILL KEEP
HIGHEST COVERAGE WELL INLAND. AREA OF HIGHER POP EXPANDS EAST ON
TUE AS DEEPER MOISTURE ALSO SPREADS EAST. IMMEDIATE COAST IS
LIKELY TO REMAIN DRY BOTH DAYS BUT MORE COVERAGE IS EXPECTED FOR
TUE.
LATE IN THE PERIOD TROPICAL MOISTURE FROM WEAK WAVE AND 5H LOW
ROUNDING PERIPHERY OF BERMUDA HIGH/5H RIDGE MAY SPREAD OVER THE
SOUTHEAST. THIS COULD RESULT IN AN INCREASE IN NOCTURNAL
CONVECTION ACROSS SC COAST AND NEAR SHORE WATERS TUE NIGHT.
TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE CLIMO. AWAY FROM THE
COAST HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S. LOWS WILL BE IN
THE MID 70S WITH SOME ISOLATED LOWER 70S INLAND.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...PROGRESSIVE MID LEVEL FLOW AND BERMUDA HIGH
WILL MAINTAIN TYPICAL SUMMERTIME CONDITIONS ACROSS THE CAROLINAS
WED AND THU. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE CLIMO
FOR THE FIRST HALF OF THE PERIOD WITH ISOLATED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS. COVERAGE WED WILL BE LIMITED
WITH STORM DEVELOPMENT DEPENDENT ON DIURNAL INSTABILITY AND WEAK
LOW LEVEL CONVERGENCE. THU ACTIVITY SHOULD BE MORE WIDESPREAD AS
MID LEVEL TROUGHING STARTS TO PUSH DOWN THE EAST COAST.
DEVELOPMENT OF MID LEVEL TROUGHING WILL ALSO START ADVECTING
DEEPER MOISTURE OVER THE SOUTHEAST...ENHANCING STORM COVERAGE.
PRECIP CHANCES SIGNIFICANTLY INCREASE DURING THE SECOND HALF OF
THE PERIOD AS EAST COAST MID LEVEL TROUGHING STRENGTHENS...
EVENTUALLY BECOMING CUT OFF LATE IN THE PERIOD. AS 5H TROUGH DIGS
DOWN THE EAST COAST FRI INTO SAT...PUSHING A COLD FRONT INTO THE
REGION..A TROPICAL WAVE MOVES ACROSS CUBA AND INTO FL. TROPICAL
MOISTURE FROM THE WAVE AND DEEP SOUTHERLY FLOW PUSH PRECIPITABLE
WATER VALUES WELL OVER 2 INCHES. DEEP MOISTURE...WEAKLY DIVERGENT
FLOW ALOFT AND STEEPENING LAPSE RATES COMBINED WITH CONVERGENCE
ALONG DISSIPATING COLD FRONT SHOULD LEAD TO AN INCREASE IN
CONVECTION COVERAGE FRI AND SAT. MARGINAL MID LEVEL LAPSE RATES DO
NOT SUGGEST MUCH SEVERE WEATHER POTENTIAL BUT HEAVY RAIN IS LIKELY
TO BE AN ISSUE. INCREASING MOISTURE AND CLOUD COVER FRI/SAT WILL
HOLD HIGHS IN THE MID TO UPPER 80S BUT HELP KEEP LOWS IN THE LOW
TO MID 70S.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...HIGH PRESSURE OFFSHORE WILL CONTINUE TO GIVE US SOUTH
SOUTHEAST FLOW THROUGH THE PERIOD. NO FOG EXPECTED WITH WINDS AT
THE BOUNDARY LAYER 15+ KTS. MONDAY...MODELS INDICATE HIGH LEVEL
MOISTURE RETURNING...WITH BROKEN CIRRUS EXPECTED ALL DAY. WINDS WILL
BE A BIT MORE SOUTHWESTERLY.
EXTENDED OUTLOOK...EARLY MORNING IFR/MVFR CIGS/VSBYS POSSIBLE
THROUGH THE EXTENDED PERIOD. INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS THURSDAY AND FRIDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM SUNDAY...SOUTHERLY RETURN FLOW 10 TO 15 KTS WILL
PERSIST ACROSS THE WATERS AROUND THE PERIPHERY OF BERMUDA HIGH
PRESSURE. THE WINDS WILL ACTUALLY VEER EVER SO SLIGHTLY FROM S-SE
TO S-SW BY MORNING REMAINING AROUND 10 KTS FOR THE MOST PART. AN 8
SECOND SE SWELL WILL CONTINUE TO MIX WITH LOCALLY GENERATED WIND
WAVES TO PRODUCE TOTAL SEAS OF 2 TO 3 FT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BERMUDA HIGH WILL MAINTAIN SOUTH TO SOUTHWEST
FLOW OVER THE WATERS THROUGH THE PERIOD. LITTLE CHANGE TO SURFACE
PRESSURE GRADIENT WILL KEEP SPEEDS IN THE 10 TO 15 KT RANGE. SEAS
WILL RUN 2 TO 3 FT A MIX OF SOUTHEAST SWELL AND SOUTHERLY WIND WAVE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...DOMINANT SURFACE FEATURE THROUGH THE PERIOD
CONTINUES TO BE BERMUDA HIGH BUT GRADIENT WILL TIGHTEN UP FOR THE
SECOND HALF OF THE PERIOD. ON WED SPEEDS WILL REMAIN 10 TO 15 KT
WITH WEAK GRADIENT IN PLACE. COLD FRONT SLOWLY APPROACHING FROM THE
NORTHWEST LATER THU AND THU NIGHT WILL RESULT IN A MORE DEFINED
GRADIENT WITH WIND SPEEDS EXCEEDING 15 KT AT TIMES. INCREASE IN
SPEEDS WILL BUILD SEAS FROM 2 TO 3 FT WED TO 3 TO 5 FT BY THE END
OF THE PERIOD. SEAS WILL STILL BE COMPRISED OF SOUTHEAST SWELL AND
SOUTHERLY WIND WAVE BUT THE WIND WAVE WILL BECOME THE DOMINANT
COMPONENT LATER THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR SCZ054.
NC...HIGH RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ106-
108-110.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...DL/RGZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
129 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A WEAKENING UPPER LEVEL LOW WILL PROGRESS EAST ACROSS THE MID-
ATLANTIC TONIGHT. CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE EASTERN
UNITED STATES THROUGH MID WEEK...WITH AN UNSEASONABLY DEEP UPPER
LEVEL TROUGH DIGGING SOUTHEAST IN THE MID-ATLANTIC BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM SUNDAY...
SOME VERY LIGHT SHOWERS HAVE DEVELOPED OVER THE SOUTHERN PIEDMONT
AND SANDHILLS THIS MORNING. AS WITH YESTERDAY...THE HRRR HIGH RES
CAM IS DOING A GOOD JOB SIMULATING THE CURRENT SHOWER ACTIVITY. THE
LATEST RUN OF THE HRRR SHOWS AN INCREASE IN SHOWER COVERAGE...MAINLY
IN THE NORTHEAST PIEDMONT AND SANDHILLS THROUGH THIS AFTERNOON...
WITH THE MORE WIDESPREAD CONVECTION MOVING INTO THE NORTHWEST
PIEDMONT LATE THIS AFT/EVE. 12Z UPPER AIR ANALYSES SHOW THE LOW WEST
OF THE APPALACHIANS OVER IL/IN...WITH HIGH PRESSURE OFF THE CAROLINA
COAST. WHILE CENTRAL NC IS RELATIVELY DRY...LOW LEVEL MOISTURE IS
ADVECTING IN OFF THE GULF AHEAD OF THE LOW PRESSURE SYSTEM. AS THE
UPPER LEVEL LOW MOVES EASTWARD TODAY SO WILL THE LOW/MID LEVEL
MOISTURE AND SHOWERS/STORMS...CURRENTLY OVER THE MOUNTAINS. -KC
PRECIPITATION CHANCES:
SW FLOW ALOFT WILL STRENGTHEN FROM THE WEST TODAY...WITH AN
INCREASING POTENTIAL FOR SMALL AMPLITUDE SHORTWAVES TRACKING
NORTHEAST ACROSS WESTERN NC/VA THIS AFT/EVE...FOLLOWED BY ADDITIONAL
DPVA WITHIN INCREASINGLY CYCLONIC FLOW ALOFT AS THE UPPER LEVEL LOW
TRACKS INTO WESTERN PA BETWEEN 00-06Z TONIGHT. SHALLOW CONVERGENCE
IN VICINITY OF A DEVELOPING PIEDMONT SFC TROUGH ASSOCIATED WITH
SUBTLE HEIGHT FALLS IN ADVANCE OF THE UPPER LEVEL WAVE APPROACHING
THE REGION THIS AFT/EVE WILL SERVE AS A POTENTIAL FOCUS FOR DIURNAL
CONVECTION THIS AFTERNOON...FOLLOWED BY SOMEWHAT DEEPER CONVERGENCE
TONIGHT AS THE LOW-LEVEL TROUGH SHARPENS IN RESPONSE TO STRONGER
HEIGHT FALLS /CYCLONIC FLOW ALOFT/ OVER THE MID-ATLANTIC. SEASONAL
BOUNDARY LAYER MOISTURE/DESTABILIZATION CAN BE EXPECTED AGAIN THIS
AFTERNOON...WITH MLCAPE VALUES GENERALLY IN THE 1000-2000 J/KG RANGE
ACROSS CENTRAL NC...THOUGH A WEST-EAST MID-LEVEL MOISTURE GRADIENT
WILL PERSIST WITH DEEPER MOISTURE ACROSS THE FOOTHILLS/WESTERN
PIEDMONT AND A DRIER AIRMASS ALOFT IN THE COASTAL PLAIN. WITH THE
ABOVE IN MIND...EXPECT THE BEST CHANCE FOR CONVECTION THIS AFTERNOON
AND EARLY EVENING WEST OF THE HWY 1 CORRIDOR IN VICINITY OF THE
PIEDMONT SFC TROUGH AND IN CLOSER PROXIMITY TO SMALL AMPLITUDE
SHORTWAVES/DEEPER MOISTURE IN STRENGTHENING SW FLOW ALOFT. WILL
INDICATE PRECIP CHANCES RANGING FROM 20% EAST OF I-95 TO 50-60% IN
THE FAR W/NW PIEDMONT. CONVECTION SHOULD PERSIST INTO TONIGHT ACROSS
THE NORTHERN AND WESTERN PIEDMONT AS BETTER DPVA /STRONGER CYCLONIC
FLOW ALOFT/ PROGRESSES INTO THE MID-ATLANTIC.
TEMPERATURES:
EXPECT HIGHS TODAY SIMILAR TO PREVIOUS DAYS WITH VERY SIMILAR
REASONING...THOUGH PERHAPS SLIGHTLY WARMER GIVEN A MORE
SOUTHWESTERLY LOW-LEVEL FLOW...ESP. ALONG AND EAST OF THE HWY 1
CORRIDOR...WITH HIGHS RANGING FROM THE MID 80S FAR NW PIEDMONT TO
UPPER 80S AND LOWER 90S ELSEWHERE. LOWS TONIGHT SIMILAR TO PREVIOUS
NIGHTS IN THE LOWER 70S.
SEVERE THREAT:
GIVEN DEEP LAYER SHEAR IN THE 25-35 KT RANGE ACROSS THE N/NW
PIEDMONT IN THE PRESENCE OF MODERATE INSTABILITY (1000-2000 J/KG
MLCAPE) AND DCAPE VALUES PROGGED AS HIGH AS 1000-1500 J/KG THIS AFT
AND EARLY EVE...ANTICIPATE A POTENTIAL FOR DAMAGING WINDS...
PRIMARILY WEST AND NW OF THE TRIANGLE. -VINCENT
&&
.SHORT TERM /MONDAY/...
AS OF 325 AM SUNDAY...
ALTHOUGH THE AFOREMENTIONED UPPER LEVEL WAVE WILL TRACK EAST THROUGH
THE MID-ATLANTIC EARLY MONDAY MORNING...CYCLONIC FLOW ALOFT AND
LOW-LEVEL TROUGHING WILL PERSIST ACROSS THE AREA MONDAY
AFT/EVE...WITH ADDITIONAL SHORTWAVE ENERGY ANTICIPATED TO DIG
SOUTHEAST INTO NC/VA IN VICINITY OF PEAK HEATING. AS A RESULT...
EXPECT ABOVE NORMAL CHANCES FOR CONVECTION...PRIMARILY DURING THE
AFTERNOON AND EVENING HOURS...WITH HIGHS SIMILAR TO PREVIOUS DAYS...
IN THE MID/UPPER 80S TO NEAR 90F. -VINCENT
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
NWP GUIDANCE IS IN GOOD AGREEMENT OF ANOTHER PERIOD OF UNSETTLED
WEATHER WITH ABOVE NORMAL CHANCES OF PRECIPITATION FOR THE UPCOMING
WEEK. THE EXTENDED RANGE WILL FEATURE A PERSISTENT AND STRONG RIDGE
ACROSS THE SOUTHERN ROCKY MOUNTAINS AND A WEAKER BUT RELATIVELY
STATIONARY AREA OF RIDGING OFF THE SOUTHEAST U.S. COAST. A SLOWLY
WESTWARD ADVANCING CLOSED UPPER LOW MOVES WEST UNDER THE SUBTROPICAL
ATLANTIC RIDGE REACHING FLORIDA ON TUESDAY AND THEN MOVES INTO THE
EASTERN GULF OF MEXICO ON WEDNESDAY AND THURSDAY. A DIGGING SHORT
WAVE TROUGH AND ASSOCIATED COLD FRONT DROPS INTO THE GREAT LAKES
REGION ON WEDNESDAY REACHING THE MID ATLANTIC LATE THURSDAY AND THEN
CLOSES OFF ON FRIDAY. THIS UPPER LOW DRIFTS SOUTHWEST INTO THE
EASTERN TENNESSEE VALLEY BY SATURDAY. THE AIR MASS THROUGH THE
PERIOD WILL REMAIN MOIST AND UNSTABLE WITH AN AXIS OF HIGH
PRECIPITABLE WATER LINGERING ACROSS THE CAROLINAS AND VIRGINIA
THROUGH MOST/ALL OF THE PERIOD.
SENSIBLE WEATHER CONDITIONS WILL FEATURE AN UNSETTLED SUMMERTIME
PATTERN WITH A HUMID AIR MASS AND THE THREAT OF MAINLY AFTERNOON AND
EVENING CONVECTION EACH DAY. THE THREAT OF CONVECTION WILL BE
GREATEST ON THURSDAY AND THURSDAY NIGHT WHEN NWP GUIDANCE IS IN GOOD
AGREEMENT THAT A SHORTWAVE TROUGH AND COLD FRONT WILL APPROACH THE
REGION. UNSETTLED WEATHER WITH ABOVE CLIMATOLOGY POPS WILL LIKELY
PERSIST ON FRIDAY THROUGH SATURDAY ALTHOUGH THERE IS STILL SOME
UNCERTAINTY ON WHERE THE SURFACE BOUNDARY AND MAIN MOISTURE FEED
WILL SETUP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED WITH HIGHS
AROUND 90 WITH MORNING LOWS IN THE LOWER TO MID 70S. -BLAES
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 125 PM SUNDAY...
24-HR TAF PERIOD:
CIGS HAVE BEEN BORDERLINE VFR/MVFR ALL DAY...BOUNCING BACK AND FORTH
BETWEEN THE TWO...AND WILL LIKELY CONTINUE TO BE SO THROUGH MONDAY
MORNING. LIGHT SHOWERS ARE OCCURRING AROUND KRDU...WITH HEAVIER
SHOWERS AND POSSIBLE THUNDER MOVING INTO THE TRIAD (KINT AND KGSO)
THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. BEST CHANCE FOR LOW-END
MVFR CIGS AT KINT AND KGSO DURING THE PRE-DAWN HOURS MONDAY...WITH
THE POTENTIAL FOR A PERIOD OF BORDERLINE VFR/MVFR CIGS ELSEWHERE...
ALTHOUGH CONFIDENCE IS LOW GIVEN THE DIFFERENCES IN MODEL GUIDANCE
AT THIS TIME. THERE IS THE CHANCE FOR SHOWERS TO REDEVELOP ACROSS
THE AREA MONDAY AFTERNOON/EVENING...BUT WILL LEAVE MENTION OUT OF
TAFS FOR NOW. -KC
LOOKING AHEAD:
AVIATION CONDITIONS THROUGH MID/LATE WEEK WILL BE CHARACTERIZED BY
AN ABOVE NORMAL CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY
(PRIMARILY AFTERNOON AND EVENING HOURS) IN ASSOCIATION WITH CYCLONIC
FLOW ALOFT AND AN ABOVE NORMAL CHANCE FOR MVFR/IFR STRATUS OR FOG
EACH MORNING (PRIMARILY 07-13Z) IN ASSOCIATION WITH A PERSISTENT
MOIST SOUTHERLY RETURN FLOW. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1027 AM EDT SUN JUL 7 2013
.SYNOPSIS...
A WEAKENING UPPER LEVEL LOW WILL TRACK INTO THE OHIO VALLEY THIS
AFTERNOON...PROGRESSING EAST ACROSS THE MID-ATLANTIC TONIGHT.
CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE EASTERN UNITED STATES
THROUGH MID WEEK...WITH AN UNSEASONABLY DEEP UPPER LEVEL TROUGH
DIGGING SOUTHEAST IN THE MID-ATLANTIC BY FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM SUNDAY...
SOME VERY LIGHT SHOWERS HAVE DEVELOPED OVER THE SOUTHERN PIEDMONT
AND SANDHILLS THIS MORNING. AS WITH YESTERDAY...THE HRRR HIGH RES
CAM IS DOING A GOOD JOB SIMULATING THE CURRENT SHOWER ACTIVITY. THE
LATEST RUN OF THE HRRR SHOWS AN INCREASE IN SHOWER COVERAGE...MAINLY
IN THE NORTHEAST PIEDMONT AND SANDHILLS THROUGH THIS AFTERNOON...
WITH THE MORE WIDESPREAD CONVECTION MOVING INTO THE NORTHWEST
PIEDMONT LATE THIS AFT/EVE. 12Z UPPER AIR ANALYSES SHOW THE LOW WEST
OF THE APPALACHIANS OVER IL/IN...WITH HIGH PRESSURE OFF THE CAROLINA
COAST. WHILE CENTRAL NC IS RELATIVELY DRY...LOW LEVEL MOISTURE IS
ADVECTING IN OFF THE GULF AHEAD OF THE LOW PRESSURE SYSTEM. AS THE
UPPER LEVEL LOW MOVES EASTWARD TODAY SO WILL THE LOW/MID LEVEL
MOISTURE AND SHOWERS/STORMS...CURRENTLY OVER THE MOUNTAINS. -KC
PRECIPITATION CHANCES:
SW FLOW ALOFT WILL STRENGTHEN FROM THE WEST TODAY...WITH AN
INCREASING POTENTIAL FOR SMALL AMPLITUDE SHORTWAVES TRACKING
NORTHEAST ACROSS WESTERN NC/VA THIS AFT/EVE...FOLLOWED BY ADDITIONAL
DPVA WITHIN INCREASINGLY CYCLONIC FLOW ALOFT AS THE UPPER LEVEL LOW
TRACKS INTO WESTERN PA BETWEEN 00-06Z TONIGHT. SHALLOW CONVERGENCE
IN VICINITY OF A DEVELOPING PIEDMONT SFC TROUGH ASSOCIATED WITH
SUBTLE HEIGHT FALLS IN ADVANCE OF THE UPPER LEVEL WAVE APPROACHING
THE REGION THIS AFT/EVE WILL SERVE AS A POTENTIAL FOCUS FOR DIURNAL
CONVECTION THIS AFTERNOON...FOLLOWED BY SOMEWHAT DEEPER CONVERGENCE
TONIGHT AS THE LOW-LEVEL TROUGH SHARPENS IN RESPONSE TO STRONGER
HEIGHT FALLS /CYCLONIC FLOW ALOFT/ OVER THE MID-ATLANTIC. SEASONAL
BOUNDARY LAYER MOISTURE/DESTABILIZATION CAN BE EXPECTED AGAIN THIS
AFTERNOON...WITH MLCAPE VALUES GENERALLY IN THE 1000-2000 J/KG RANGE
ACROSS CENTRAL NC...THOUGH A WEST-EAST MID-LEVEL MOISTURE GRADIENT
WILL PERSIST WITH DEEPER MOISTURE ACROSS THE FOOTHILLS/WESTERN
PIEDMONT AND A DRIER AIRMASS ALOFT IN THE COASTAL PLAIN. WITH THE
ABOVE IN MIND...EXPECT THE BEST CHANCE FOR CONVECTION THIS AFTERNOON
AND EARLY EVENING WEST OF THE HWY 1 CORRIDOR IN VICINITY OF THE
PIEDMONT SFC TROUGH AND IN CLOSER PROXIMITY TO SMALL AMPLITUDE
SHORTWAVES/DEEPER MOISTURE IN STRENGTHENING SW FLOW ALOFT. WILL
INDICATE PRECIP CHANCES RANGING FROM 20% EAST OF I-95 TO 50-60% IN
THE FAR W/NW PIEDMONT. CONVECTION SHOULD PERSIST INTO TONIGHT ACROSS
THE NORTHERN AND WESTERN PIEDMONT AS BETTER DPVA /STRONGER CYCLONIC
FLOW ALOFT/ PROGRESSES INTO THE MID-ATLANTIC.
TEMPERATURES:
EXPECT HIGHS TODAY SIMILAR TO PREVIOUS DAYS WITH VERY SIMILAR
REASONING...THOUGH PERHAPS SLIGHTLY WARMER GIVEN A MORE
SOUTHWESTERLY LOW-LEVEL FLOW...ESP. ALONG AND EAST OF THE HWY 1
CORRIDOR...WITH HIGHS RANGING FROM THE MID 80S FAR NW PIEDMONT TO
UPPER 80S AND LOWER 90S ELSEWHERE. LOWS TONIGHT SIMILAR TO PREVIOUS
NIGHTS IN THE LOWER 70S.
SEVERE THREAT:
GIVEN DEEP LAYER SHEAR IN THE 25-35 KT RANGE ACROSS THE N/NW
PIEDMONT IN THE PRESENCE OF MODERATE INSTABILITY (1000-2000 J/KG
MLCAPE) AND DCAPE VALUES PROGGED AS HIGH AS 1000-1500 J/KG THIS AFT
AND EARLY EVE...ANTICIPATE A POTENTIAL FOR DAMAGING WINDS...
PRIMARILY WEST AND NW OF THE TRIANGLE. -VINCENT
&&
.SHORT TERM /MONDAY/...
AS OF 325 AM SUNDAY...
ALTHOUGH THE AFOREMENTIONED UPPER LEVEL WAVE WILL TRACK EAST THROUGH
THE MID-ATLANTIC EARLY MONDAY MORNING...CYCLONIC FLOW ALOFT AND
LOW-LEVEL TROUGHING WILL PERSIST ACROSS THE AREA MONDAY
AFT/EVE...WITH ADDITIONAL SHORTWAVE ENERGY ANTICIPATED TO DIG
SOUTHEAST INTO NC/VA IN VICINITY OF PEAK HEATING. AS A RESULT...
EXPECT ABOVE NORMAL CHANCES FOR CONVECTION...PRIMARILY DURING THE
AFTERNOON AND EVENING HOURS...WITH HIGHS SIMILAR TO PREVIOUS DAYS...
IN THE MID/UPPER 80S TO NEAR 90F. -VINCENT
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...
NWP GUIDANCE IS IN GOOD AGREEMENT OF ANOTHER PERIOD OF UNSETTLED
WEATHER WITH ABOVE NORMAL CHANCES OF PRECIPITATION FOR THE UPCOMING
WEEK. THE EXTENDED RANGE WILL FEATURE A PERSISTENT AND STRONG RIDGE
ACROSS THE SOUTHERN ROCKY MOUNTAINS AND A WEAKER BUT RELATIVELY
STATIONARY AREA OF RIDGING OFF THE SOUTHEAST U.S. COAST. A SLOWLY
WESTWARD ADVANCING CLOSED UPPER LOW MOVES WEST UNDER THE SUBTROPICAL
ATLANTIC RIDGE REACHING FLORIDA ON TUESDAY AND THEN MOVES INTO THE
EASTERN GULF OF MEXICO ON WEDNESDAY AND THURSDAY. A DIGGING SHORT
WAVE TROUGH AND ASSOCIATED COLD FRONT DROPS INTO THE GREAT LAKES
REGION ON WEDNESDAY REACHING THE MID ATLANTIC LATE THURSDAY AND THEN
CLOSES OFF ON FRIDAY. THIS UPPER LOW DRIFTS SOUTHWEST INTO THE
EASTERN TENNESSEE VALLEY BY SATURDAY. THE AIR MASS THROUGH THE
PERIOD WILL REMAIN MOIST AND UNSTABLE WITH AN AXIS OF HIGH
PRECIPITABLE WATER LINGERING ACROSS THE CAROLINAS AND VIRGINIA
THROUGH MOST/ALL OF THE PERIOD.
SENSIBLE WEATHER CONDITIONS WILL FEATURE AN UNSETTLED SUMMERTIME
PATTERN WITH A HUMID AIR MASS AND THE THREAT OF MAINLY AFTERNOON AND
EVENING CONVECTION EACH DAY. THE THREAT OF CONVECTION WILL BE
GREATEST ON THURSDAY AND THURSDAY NIGHT WHEN NWP GUIDANCE IS IN GOOD
AGREEMENT THAT A SHORTWAVE TROUGH AND COLD FRONT WILL APPROACH THE
REGION. UNSETTLED WEATHER WITH ABOVE CLIMATOLOGY POPS WILL LIKELY
PERSIST ON FRIDAY THROUGH SATURDAY ALTHOUGH THERE IS STILL SOME
UNCERTAINTY ON WHERE THE SURFACE BOUNDARY AND MAIN MOISTURE FEED
WILL SETUP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED WITH HIGHS
AROUND 90 WITH MORNING LOWS IN THE LOWER TO MID 70S. -BLAES
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 700 AM SUNDAY...
24-HR TAF PERIOD:
SUB-VFR STRATUS AT THE INT/GSO TERMINALS WILL GRADUALLY LIFT AND
SCATTER OUT TO VFR BY 13-15Z. EXPECT ISOLD/SCT CONVECTION THIS
AFTERNOON THROUGH THIS EVENING (16-04Z)...WITH THE BEST CHANCE AT
THE INT/GSO TERMINALS. A CHANCE OF SHOWERS WILL PERSIST OVERNIGHT/
MONDAY MORNING AS AN UPPER LEVEL DISTURBANCE TRACKS EAST THROUGH THE
OH VALLEY INTO THE MID-ATLANTIC...ALONG WITH A POTENTIAL FOR
MVFR/IFR CEILINGS BY 08-12Z MON.
LOOKING AHEAD:
AVIATION CONDITIONS THROUGH MID/LATE WEEK WILL BE CHARACTERIZED BY
AN ABOVE NORMAL CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY
(PRIMARILY AFTERNOON AND EVENING HOURS) IN ASSOCIATION WITH CYCLONIC
FLOW ALOFT AND AN ABOVE NORMAL CHANCE FOR MVFR/IFR STRATUS OR FOG
EACH MORNING (PRIMARILY 07-13Z) IN ASSOCIATION WITH A PERSISTENT
MOIST SOUTHERLY RETURN FLOW. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1013 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 1013 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO EXTEND THE SEVERE THUNDERSTORM WATCH EAST
INTO THE JAMES RIVER VALLEY.
MCS OVER WEST CENTRAL NORTH DAKOTA DEVELOPED INTO AN MCV IN THE
LAST HOUR OR TWO. THE LEADING EDGE OF THIS ACTIVITY HAS BEEN
PRODUCING WIDESPREAD WIND GUSTS UP TO 60 MPH. THIS ACTIVITY WILL
CONTINUE TO PUSH EAST INTO THE JAMES RIVER VALLEY AFTER MIDNIGHT.
ANOTHER BOW ECHO IS PUSHING EAST ACROSS SOUTHWESTERN NORTH DAKOTA.
ITS STORM MOTION HAS BEEN EAST-SOUTHEAST AND WILL LIKELY CONTINUE
TO PUSH INTO SOUTH DAKOTA DURING THE NEXT FEW HOURS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 703 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO ADD SEVERE THUNDERSTORM WATCH 402 FOR
AREAS WEST OF HIGHWAY 83.
ONGOING CONVECTION OVER EAST-CENTRAL MONTANA SHOULD CONTINUE TO
MOVE EAST-SOUTHEAST INTO SOUTHWESTERN NORTH DAKOTA EARLY THIS
EVENING. THIS ACTIVITY IS CONGEALING INTO AN MCS AND IS MOVING
INTO A FAVORABLE ENVIRONMENT FOR MCS MAINTENANCE (SURFACE BASED
CAPE AROUND 2000 J/KG PER LATEST LAPS ANALYSIS). THIS INITIAL
CONVECTIVE ACTIVITY PROMPTED SPC TO ISSUE A SEVERE THUNDERSTORM
WATCH FOR AREAS WEST OF HIGHWAY 83 UNTIL MIDNIGHT CDT.
SHORT-RANGE MESOSCALE MODELS CONTINUE TO PROG THE PRIMARY LINE
OF CONVECTION (CURRENTLY EXTENDING FROM GLASGOW TO BILLINGS) TO
PUSH INTO WESTERN NORTH DAKOTA AROUND 03Z...AND SWEEP ACROSS THE
CWA TONIGHT. THE FLY IN THE OINTMENT IS JUST HOW MUCH INSTABILITY
THE INITIAL MCS CHEWS UP BEFORE THE PRIMARY LINE SWINGS THROUGH.
STILL WILL MAINTAIN SEVERE WORDING PAST MIDNIGHT FOR CENTRAL NORTH
DAKOTA. HOWEVER...WILL CONTINUE TO MONITOR EVENING TRENDS AND
MAKE ANY ADJUSTMENTS AS NEEDED. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FORECAST ISSUE DURING THE SHORT TERM IS STORM
COVERAGE/TIMING/SEVERITY THROUGH TONIGHT. SCATTERED STORMS ARE
EXPECTED TO DEVELOP AND/OR MOVE INTO THE WEST LATE THIS AFTERNOON.
MORE FAVORABLE DEEP LAYER SHEAR IS CONFINED TO THE WEST THROUGH
LATE AFTERNOON. SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH
LARGE HAIL THE MAIN THREAT. THE HRRR IS STILL FOCUSING ON THE SOUTHWEST
FOR INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING
FROM WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. WILL CONTINUE
TO MONITOR CLOSELY FOR INITIATION. AN INTENSE SUPERCELL IS MOVING
THROUGH NORTHEAST MONTANA...AND WOULD IMPACT THE FORECAST AREA
AFTER 00Z IF IT HOLDS TOGETHER. A BIGGER CONCERN WILL BE A
THUNDERSTORM COMPLEX THAT WILL LIKELY TRACK FROM WEST TO EAST
ACROSS THE FORECAST AREA AFTER AROUND 9 PM CDT. DAMAGING STRAIGHT
LINE WINDS WILL BE THE BIGGEST THREAT. FAST STORM MOTIONS SHOULD
PRECLUDE WIDESPREAD FLASH FLOODING. A MULTI- MEDIA WEATHER BRIEFING
HAS BEEN POSTED AT WWW.WEATHER.GOV/BIS. THE SEVERE THREAT MAY
PERSIST AFTER MIDNIGHT TONIGHT BEFORE STORMS WEAKEN. ADDITIONAL
NON-SEVERE STORMS WILL BE LIKELY THROUGH AT LEAST MIDDAY TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
MAIN HIGHLIGHT FOR THE LONG TERM IS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT ENTERING NORTHERN PLAINS THURSDAY/FRIDAY.
THE PERSISTENT HIGH AMPLITUDE RIDGING TO THE WEST WILL CONTINUE TO
BE BOMBARDED BY SHORTWAVE TROUGHS DIVING DOWN OUT OF WESTERN
CANADA. THIS WILL FORCE THE RIDGE TO TRANSLATE EASTWARD OVER THE
CENTRAL STATES. THIS WILL IN TURN ALLOW NORTH DAKOTA TO BE
INFLUENCED BY SOUTHWESTERLY FLOW AND LEE CYCLOGENESIS. BOTH THE
12 UTC ECMWF AND THE 12 UTC GFS BOTH HAVE A SHORTWAVE TROUGH
DRAPED ACROSS THE NORTHERN PLAINS AND SURFACE LOW OVER
NORTHWESTERN SOUTH DAKOTA EARLY FRIDAY MORNING. THIS WILL ALLOW
FOR MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT. WITH INCREASING
MOISTURE...SURFACE LOW PRESSURE...AND UPPER LEVEL DIFFLUENCE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS POSSIBLE FRIDAY AFTERNOON
AND EVENING. IN ADDITION TO THOSE INGREDIENTS THE 12 UTC ECMWF IS
FORECASTING 50+ KNOTS OF 0-6 KM SHEAR...2000+ MUCAPE...AND DEW
POINTS IN THE MID TO UPPER 60S. IF THIS VERIFIES...SEVERE WEATHER
IS POSSIBLE FRIDAY AFTERNOON AND EVENING.
OTHERWISE...THE EXTENDED PERIOD LOOKS ACTIVE WITH CHANCES FOR
PRECIP THROUGHOUT THE PERIOD AS SHORTWAVES RIDE ALONG THE
NORTHERN PERIPHERY OF THE RIDGE TO OUR SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 703 PM CDT MON JUL 8 2013
THE MAIN FOCUS THROUGH THE TAF PERIOD IS THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. SCATTERED STORMS ARE EXPECTED
THIS EVENING...BUT TOUGH TO PINPOINT FAVORED AREA FOR DEVELOPMENT
AND TIMING. LATER TONIGHT...AFTER 02Z...ENHANCED WINDS WILL BE
POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS. ALTHOUGH THESE
SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO UNCERTAIN IN TIMING
TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS SHOULD ANTICIPATE
MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO EAST ACROSS THE
STATE AFTER 02Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...RPK
LONG TERM...AJ
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
703 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 703 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO ADD SEVERE THUNDERSTORM WATCH 402 FOR
AREAS WEST OF HIGHWAY 83.
ONGOING CONVECTION OVER EAST-CENTRAL MONTANA SHOULD CONTINUE TO
MOVE EAST-SOUTHEAST INTO SOUTHWESTERN NORTH DAKOTA EARLY THIS
EVENING. THIS ACTIVITY IS CONGEALING INTO AN MCS AND IS MOVING
INTO A FAVORABLE ENVIRONMENT FOR MCS MAINTENANCE (SURFACE BASED
CAPE AROUND 2000 J/KG PER LATEST LAPS ANALYSIS). THIS INITIAL
CONVECTIVE ACTIVITY PROMPTED SPC TO ISSUE A SEVERE THUNDERSTORM
WATCH FOR AREAS WEST OF HIGHWAY 83 UNTIL MIDNIGHT CDT.
SHORT-RANGE MESOSCALE MODELS CONTINUE TO PROG THE PRIMARY LINE
OF CONVECTION (CURRENTLY EXTENDING FROM GLASGOW TO BILLINGS) TO
PUSH INTO WESTERN NORTH DAKOTA AROUND 03Z...AND SWEEP ACROSS THE
CWA TONIGHT. THE FLY IN THE OINTMENT IS JUST HOW MUCH INSTABILITY
THE INITIAL MCS CHEWS UP BEFORE THE PRIMARY LINE SWINGS THROUGH.
STILL WILL MAINTAIN SEVERE WORDING PAST MIDNIGHT FOR CENTRAL NORTH
DAKOTA. HOWEVER...WILL CONTINUE TO MONITOR EVENING TRENDS AND
MAKE ANY ADJUSTMENTS AS NEEDED. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FORECAST ISSUE DURING THE SHORT TERM IS STORM
COVERAGE/TIMING/SEVERITY THROUGH TONIGHT. SCATTERED STORMS ARE
EXPECTED TO DEVELOP AND/OR MOVE INTO THE WEST LATE THIS AFTERNOON.
MORE FAVORABLE DEEP LAYER SHEAR IS CONFINED TO THE WEST THROUGH
LATE AFTERNOON. SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH
LARGE HAIL THE MAIN THREAT. THE HRRR IS STILL FOCUSING ON THE SOUTHWEST
FOR INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING
FROM WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. WILL CONTINUE
TO MONITOR CLOSELY FOR INITIATION. AN INTENSE SUPERCELL IS MOVING
THROUGH NORTHEAST MONTANA...AND WOULD IMPACT THE FORECAST AREA
AFTER 00Z IF IT HOLDS TOGETHER. A BIGGER CONCERN WILL BE A
THUNDERSTORM COMPLEX THAT WILL LIKELY TRACK FROM WEST TO EAST
ACROSS THE FORECAST AREA AFTER AROUND 9 PM CDT. DAMAGING STRAIGHT
LINE WINDS WILL BE THE BIGGEST THREAT. FAST STORM MOTIONS SHOULD
PRECLUDE WIDESPREAD FLASH FLOODING. A MULTI- MEDIA WEATHER BRIEFING
HAS BEEN POSTED AT WWW.WEATHER.GOV/BIS. THE SEVERE THREAT MAY
PERSIST AFTER MIDNIGHT TONIGHT BEFORE STORMS WEAKEN. ADDITIONAL
NON-SEVERE STORMS WILL BE LIKELY THROUGH AT LEAST MIDDAY TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
MAIN HIGHLIGHT FOR THE LONG TERM IS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT ENTERING NORTHERN PLAINS THURSDAY/FRIDAY.
THE PERSISTENT HIGH AMPLITUDE RIDGING TO THE WEST WILL CONTINUE TO
BE BOMBARDED BY SHORTWAVE TROUGHS DIVING DOWN OUT OF WESTERN
CANADA. THIS WILL FORCE THE RIDGE TO TRANSLATE EASTWARD OVER THE
CENTRAL STATES. THIS WILL IN TURN ALLOW NORTH DAKOTA TO BE
INFLUENCED BY SOUTHWESTERLY FLOW AND LEE CYCLOGENESIS. BOTH THE
12 UTC ECMWF AND THE 12 UTC GFS BOTH HAVE A SHORTWAVE TROUGH
DRAPED ACROSS THE NORTHERN PLAINS AND SURFACE LOW OVER
NORTHWESTERN SOUTH DAKOTA EARLY FRIDAY MORNING. THIS WILL ALLOW
FOR MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT. WITH INCREASING
MOISTURE...SURFACE LOW PRESSURE...AND UPPER LEVEL DIFFLUENCE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS POSSIBLE FRIDAY AFTERNOON
AND EVENING. IN ADDITION TO THOSE INGREDIENTS THE 12 UTC ECMWF IS
FORECASTING 50+ KNOTS OF 0-6 KM SHEAR...2000+ MUCAPE...AND DEW
POINTS IN THE MID TO UPPER 60S. IF THIS VERIFIES...SEVERE WEATHER
IS POSSIBLE FRIDAY AFTERNOON AND EVENING.
OTHERWISE...THE EXTENDED PERIOD LOOKS ACTIVE WITH CHANCES FOR
PRECIP THROUGHOUT THE PERIOD AS SHORTWAVES RIDE ALONG THE
NORTHERN PERIPHERY OF THE RIDGE TO OUR SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 703 PM CDT MON JUL 8 2013
THE MAIN FOCUS THROUGH THE TAF PERIOD IS THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. SCATTERED STORMS ARE EXPECTED
THIS EVENING...BUT TOUGH TO PINPOINT FAVORED AREA FOR DEVELOPMENT
AND TIMING. LATER TONIGHT...AFTER 02Z...ENHANCED WINDS WILL BE
POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS. ALTHOUGH THESE
SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO UNCERTAIN IN TIMING
TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS SHOULD ANTICIPATE
MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO EAST ACROSS THE
STATE AFTER 02Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...RPK
LONG TERM...AJ
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
142 PM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 111 PM CDT SUN JUL 7 2013
UPDATE FOR ADDITIONAL ADJUSTMENTS TO POPS THROUGH TONIGHT...AND
MIDDAY TEMP TRENDS. CLOUDS HAVE INHIBITED TEMPS AT MANY
LOCATIONS...ESPECIALLY THE FAT SOUTH...BUT PARTIAL CLEARING IS
EXPECTED AS THE AFTERNOON PROGRESSES. A FEW STRONG STORMS ARE
POSSIBLE SOUTHWEST LATE THIS AFTERNOON AND EVENING IN THE AREA OF
GREATEST INSOLATION. THE LATEST HRRR AND 12 WRF ALL DEVELOP
CONVECTION AROUND 21Z-22Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN JUL 7 2013
EARLY MORNING SURFACE ANALYSIS PLACED A WEAK SURFACE TROUGH ACROSS
EASTERN NORTH DAKOTA. THE TROUGH WAS THE FOCUS FOR ISOLATED
THUNDERSTORMS EARLIER THIS MORNING...BUT THEY HAVE SINCE
DIMINISHED. THE TROUGH WILL MOVE SLOWLY EAST THIS MORNING...TAKING
THE THREAT OF ADDITIONAL THUNDERSTORMS WITH IT.
THE NEXT CONCERN WILL BE SHOWERS / THUNDERSTORMS IN EASTERN
MONTANA WHICH HAVE BEEN MAKING STEADY PROGRESS TOWARDS WESTERN
NORTH DAKOTA EARLY THIS MORNING. THE STORMS IN EASTERN MONTANA ARE
IN PART BEING DRIVEN BY A SHORT WAVE WHICH IS EXPECTED TO MOVE
INTO WESTERN NORTH DAKOTA THIS MORNING...AND INTO CENTRAL NORTH
DAKOTA THIS AFTERNOON. VARIOUS MODEL SOLUTIONS (NAM / RAP / GFS /
4KM WRF) ALL SUGGEST THERE WILL BE A CHANCE OF PRECIPITATION AS
THE WAVE MOVES ACROSS THE FORECAST AREA. WHERE THEY DIFFER TO SOME
EXTENT IS IN THEIR COVERAGE OF PRECIPITATION. WILL HOLD ONTO
CHANCE POPS ACROSS MOST OF THE FORECAST AREA TODAY / THIS EVENING
WITH THE HIGHER POPS IN THE WEST. THE LATEST DAY 1 OUTLOOK PLACES
THE SOUTHWEST PART OF THE STATE IN A SLIGHT RISK...WHICH APPEARS
REASONABLE SINCE THAT AREA IS FORECAST TO HAVE THE GREATEST
INSTABILITY THIS AFTERNOON / EVENING WITH MLCAPE VALUES OF UP TO
1500 J/KG.
CONFIDENCE IN THUNDERSTORM COVERAGE LATE TONIGHT INTO EARLY MONDAY
MORNING DECREASES TO SOME EXTENT AS THE INITIAL WAVE MOVES EAST.
CONFLICTING SIGNALS ARE SHOWN IN THE MODEL SOLUTIONS WITH SOME
SUGGESTING LIMITED THUNDERSTORM COVERAGE OVERNIGHT...WHILE OTHERS
BRING ADDITIONAL THUNDERSTORMS INTO WESTERN NORTH DAKOTA FROM
EASTERN MONTANA. WILL HOLD ONTO CHANCE POPS IN THE CENTRAL AND
WEST...WITH SLIGHT CHANCES IN THE EAST WHERE CONFIDENCE IN
ADDITIONAL CONVECTION IS LOWER.
CLOUDS FROM SHOWERS / THUNDERSTORMS COULD INFLUENCE TEMPERATURES
TODAY. WILL FOLLOW A BLEND OF GUIDANCE VALUES WITH HIGHS NEAR 80
NORTH...AND LOWER TO MID 80S SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 7 2013
MODELS AGREE IN A SOUTHWEST FLOW ALOFT FROM THE NORTHWEST US TO
THE NORTHERN PLAINS EARLY IN THE PERIOD. AN ACTIVE SHORTWAVE
PATTERN WILL BRING SEVERAL SHORTWAVES THROUGH THE REGION BRINGING
SOME WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION MONDAY
NIGHT AND TUESDAY. THIS WILL BE FOLLOWED BY A BREAK IN THE
PRECIPITATION CHANCES WEDNESDAY AND THURSDAY AS AN H500 RIDGE
POSITIONS ITSELF OVER THE NORTHERN PLAINS. AS THIS FEATURE MOVES
EAST BY NEXT WEEKEND WILL SEE AT LEAST A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS RETURN FOR FRIDAY AND SATURDAY.
THE PRIMARY FOCUS WILL BE MONDAY NIGHT. BY MONDAY AFTERNOON LOW
PRESSURE WILL DEVELOP ACROSS MONTANA BRINGING A EASTERLY WIND FLOW
ACROSS WEST AND CENTRAL NORTH DAKOTA. THIS WILL PULL ABUNDANT
MOISTURE INTO THE REGION. MODEL SOUNDINGS FORECAST PWATS BETWEEN
1.5 AND 1.75 INCHES...OR ROUGHLY 2 STANDARD DEVIATIONS ABOVE
NORMAL IF CORRECT. WITH ABUNDANT MOISTURE WILL MENTION HEAVY RAIN
IN THE HWO ALONG WITH SLIGHT CHANCE SEVERE FROM SPC MONDAY NIGHT.
THUNDERSTORMS WILL END TUESDAY FOLLOWED BY THE DRY WEATHER
WEDNESDAYS AND THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 111 PM CDT SUN JUL 7 2013
WESTERN NORTH DAKOTA WILL BE THE PRIMARY FOCUS FOR SCATTERED
THUNDERSTORMS LATER THIS AFTERNOON AND EVENING...MAINLY IMPACTING
KDIK/KISN. STORMS ARE EXPECTED TO BE TOO SCATTERED IN NATURE TO
WARRANT MORE THAN VCTS GROUPS AT THIS TIME. OTHER THAN BRIEF MVFR
VSBYS IN THE MORE INTENSE STORMS...EXPECT VFR CONDITIONS.
ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE TOWARD
DAYBREAK AT KMOT...THEN BY MID MORNING AT KDIK/KBIS/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...CK
LONG TERM...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1043 AM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 958 AM CDT SUN JUL 7 2013
UPDATE TO SCALE BACK POPS WEST AND CENTRAL THIS AFTERNOON AND
EVENING...AS COVERAGE OF STORMS NOW EXPECTED TO BE LESS BASED ON
RECENT HI-RES MODEL RUNS. ISOLATED SEVERE STORMS WILL BE
POSSIBLE...MAINLY IN THE EARLY EVENING ACROSS THE FAR SOUTHWEST. ANOTHER
SHORT WAVE MAY GLANCE NORTHERN COUNTIES OVERNIGHT WITH ADDITIONAL
STORMS...BUT CONFIDENCE IN THIS SCENARIO IS LOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN JUL 7 2013
EARLY MORNING SURFACE ANALYSIS PLACED A WEAK SURFACE TROUGH ACROSS
EASTERN NORTH DAKOTA. THE TROUGH WAS THE FOCUS FOR ISOLATED
THUNDERSTORMS EARLIER THIS MORNING...BUT THEY HAVE SINCE
DIMINISHED. THE TROUGH WILL MOVE SLOWLY EAST THIS MORNING...TAKING
THE THREAT OF ADDITIONAL THUNDERSTORMS WITH IT.
THE NEXT CONCERN WILL BE SHOWERS / THUNDERSTORMS IN EASTERN
MONTANA WHICH HAVE BEEN MAKING STEADY PROGRESS TOWARDS WESTERN
NORTH DAKOTA EARLY THIS MORNING. THE STORMS IN EASTERN MONTANA ARE
IN PART BEING DRIVEN BY A SHORT WAVE WHICH IS EXPECTED TO MOVE
INTO WESTERN NORTH DAKOTA THIS MORNING...AND INTO CENTRAL NORTH
DAKOTA THIS AFTERNOON. VARIOUS MODEL SOLUTIONS (NAM / RAP / GFS /
4KM WRF) ALL SUGGEST THERE WILL BE A CHANCE OF PRECIPITATION AS
THE WAVE MOVES ACROSS THE FORECAST AREA. WHERE THEY DIFFER TO SOME
EXTENT IS IN THEIR COVERAGE OF PRECIPITATION. WILL HOLD ONTO
CHANCE POPS ACROSS MOST OF THE FORECAST AREA TODAY / THIS EVENING
WITH THE HIGHER POPS IN THE WEST. THE LATEST DAY 1 OUTLOOK PLACES
THE SOUTHWEST PART OF THE STATE IN A SLIGHT RISK...WHICH APPEARS
REASONABLE SINCE THAT AREA IS FORECAST TO HAVE THE GREATEST
INSTABILITY THIS AFTERNOON / EVENING WITH MLCAPE VALUES OF UP TO
1500 J/KG.
CONFIDENCE IN THUNDERSTORM COVERAGE LATE TONIGHT INTO EARLY MONDAY
MORNING DECREASES TO SOME EXTENT AS THE INITIAL WAVE MOVES EAST.
CONFLICTING SIGNALS ARE SHOWN IN THE MODEL SOLUTIONS WITH SOME
SUGGESTING LIMITED THUNDERSTORM COVERAGE OVERNIGHT...WHILE OTHERS
BRING ADDITIONAL THUNDERSTORMS INTO WESTERN NORTH DAKOTA FROM
EASTERN MONTANA. WILL HOLD ONTO CHANCE POPS IN THE CENTRAL AND
WEST...WITH SLIGHT CHANCES IN THE EAST WHERE CONFIDENCE IN
ADDITIONAL CONVECTION IS LOWER.
CLOUDS FROM SHOWERS / THUNDERSTORMS COULD INFLUENCE TEMPERATURES
TODAY. WILL FOLLOW A BLEND OF GUIDANCE VALUES WITH HIGHS NEAR 80
NORTH...AND LOWER TO MID 80S SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 7 2013
MODELS AGREE IN A SOUTHWEST FLOW ALOFT FROM THE NORTHWEST US TO
THE NORTHERN PLAINS EARLY IN THE PERIOD. AN ACTIVE SHORTWAVE
PATTERN WILL BRING SEVERAL SHORTWAVES THROUGH THE REGION BRINGING
SOME WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION MONDAY
NIGHT AND TUESDAY. THIS WILL BE FOLLOWED BY A BREAK IN THE
PRECIPITATION CHANCES WEDNESDAY AND THURSDAY AS AN H500 RIDGE
POSITIONS ITSELF OVER THE NORTHERN PLAINS. AS THIS FEATURE MOVES
EAST BY NEXT WEEKEND WILL SEE AT LEAST A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS RETURN FOR FRIDAY AND SATURDAY.
THE PRIMARY FOCUS WILL BE MONDAY NIGHT. BY MONDAY AFTERNOON LOW
PRESSURE WILL DEVELOP ACROSS MONTANA BRINGING A EASTERLY WIND FLOW
ACROSS WEST AND CENTRAL NORTH DAKOTA. THIS WILL PULL ABUNDANT
MOISTURE INTO THE REGION. MODEL SOUNDINGS FORECAST PWATS BETWEEN
1.5 AND 1.75 INCHES...OR ROUGHLY 2 STANDARD DEVIATIONS ABOVE
NORMAL IF CORRECT. WITH ABUNDANT MOISTURE WILL MENTION HEAVY RAIN
IN THE HWO ALONG WITH SLIGHT CHANCE SEVERE FROM SPC MONDAY NIGHT.
THUNDERSTORMS WILL END TUESDAY FOLLOWED BY THE DRY WEATHER
WEDNESDAYS AND THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 958 AM CDT SUN JUL 7 2013
WESTERN NORTH DAKOTA WILL BE THE PRIMARY FOCUS FOR SCATTERED
THUNDERSTORMS TODAY AND TONIGHT...MAINLY IMPACTING KDIK/KISN. STORMS
ARE EXPECTED TO BE TOO SCATTERED IN NATURE TO WARRANT MORE THAN A
VCTS GROUP AT THIS TIME. OTHER THAN BRIEF MVFR VSBYS IN THE MORE
INTENSE STORMS...EXPECT VFR CONDITIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...CK
LONG TERM...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1014 AM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 1009 AM CDT SUN JUL 7 2013
LOW CLOUDS AND FOG IN THE FAR EASTERN FCST AREA DISSIPATING AS
EXPECTED. SOME PATCHY LOWER CLOUDS ROSEAU TO FOSSTON BUT AND THIS
BAND IS RIGHT ALONG THE WEAK SFC BOUNDARY. STILL TAKE SOME TIME TO
FULLY BREAKUP LOW CLOUDS IN THE EAST BUT SHOULD DO SO BY 17Z-18Z
AT THE LASTEST AS WINDS START TO INCREASE ENOUGH. OTHERWISE GOT
SOME HIGH CLOUDS SPREADING INTO DVL BASIN AND LIKELY WILL SPREAD
INTO SOUTHWESTERN FCST AREA AHD OF AREA OF SHOWERS/STORMS MOVING
THRU FAR SOUTH CENTRAL ND AND NORTHWESTERN SD. HRRR SEEMS
REASONABLE IN SHOWING ANY SHOWERS DYING OUT BEFORE REACHING
SOUTHWESTERN FCST AREA WITH ACTIVITY SHIFTING MORE INTO SOUTH
DAKOTA. THUS DRY FCST THRU 00Z IS GOOD. TOOK HIGH TEMPS DOWN A
LITTLE BIT...DUE TO SLOW START.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 258 AM CDT SUN JUL 7 2013
THE MAIN UPPER SHORTWAVE HAS BEEN LIFTING OFF INTO CANADA...WITH A
SFC BOUNDARY TRAILING SOUTH INTO EASTERN ND. WINDS HAVE ALREADY
SHIFTED TO THE WEST IN THE DEVILS LAKE BASIN AND DRIER AIR HAS
STARTED TO MOVE IN. MOIST AIR AND LIGHT WINDS CONTINUE FROM THE
RED RIVER VALLEY EASTWARD. THERE HAS BEEN SOME FOG FORMATION IN
SOME SPOTS...BUT WITH THE BOUNDARY COMING THROUGH THINK THAT IT
WILL BE SHORT LIVED. STORMS ALONG THE FRONT AS IT WENT THROUGH THE
DEVILS LAKE BASIN HAVE DISSIPATED...BUT WILL HOLD ONTO 20 POPS FOR
A BIT LONGER AS THE BOUNDARY MOVES THROUGH AND TAKE ANOTHER LOOK
BEFORE SENDING GRIDS OUT.
WEAK SFC HIGH PRESSURE WILL BUILD IN TODAY AND CONDITIONS WILL BE
FAIRLY QUIET. WITH PLENTY OF SUN HIGHS AGAIN SHOULD RANGE FROM THE
UPPER 70S TO MID 80S. NEAR ZONAL FLOW CONTINUES INTO
TONIGHT...WITH A WEAK SHORTWAVE BRINGING SOME CONVECTION TO
WESTERN ND. THINK THERE IS THE POSSIBILITY OF SOME ACTIVITY
DRIFTING INTO OUR FAR WESTERN COUNTIES LATE TONIGHT SO KEPT LOW
POPS GOING FOR NOW IN THAT AREA.
THE WEAK SHORTWAVE TROUGH WILL CONTINUE TO MOVE EASTWARD INTO
MONDAY...BUT THE MORE SIGNIFICANT SFC FEATURES WILL STAY TO THE
WEST AS A TROUGH DEVELOPS IN THE LEE OF THE ROCKIES. WINDS WILL
SHIFT BACK TO THE SOUTH AND HIGHS WILL AGAIN BE MAINLY IN THE 80S.
CONTINUED TO KEEP LOW POPS GOING IN THE WEST FOR ANY ACTIVITY
DRIFTING IN FROM CENTRAL ND.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 258 AM CDT SUN JUL 7 2013
MONDAY NIGHT INTO TUESDAY...A MORE SIGNIFICANT SHORTWAVE TROUGH
WILL BEGIN TO DIG DOWN INTO THE NORTHWESTERN PLAINS OUT OF CANADA
AND THEN MOVE THROUGH THE DAKOTAS. THERE SHOULD BE A DECENT SFC
TROUGH AND A COLD FRONT MOVING THROUGH DURING THE DAY ON TUESDAY.
MODELS ARE IN FAIRLY DECENT AGREEMENT ON BRINGING PRECIP THROUGH
MONDAY NIGHT INTO TUESDAY AS THE UPPER TROUGH AND SFC BOUNDARY
COME THROUGH ALTHOUGH THERE ARE DIFFERENCES IN TIMING AND
PLACEMENT. KEPT HIGH CHANCE TO LIKELY POPS GOING FOR NOW WITH ONLY
A FEW TWEAKS. PRECIP WILL TAPER OFF TUESDAY NIGHT AS HIGH PRESSURE
BUILDS IN. THE FRONT SHOULD KNOCK BACK TEMPS A FEW DEGREES
TUESDAY INTO TUESDAY NIGHT.
WEDNESDAY-SATURDAY...THE DEPARTING SHORTWAVE TROUGH WILL DIVE INTO
THE NORTHERN GREAT LAKES ON WEDNESDAY AS UPPER RIDGING BEGINS TO
AMPLIFY ACROSS THE ROCKIES. SURFACE HIGH PRESSURE BENEATH NORTHWEST
FLOW ALOFT WILL RESULT IN DRY WEATHER WEDNESDAY AND THURSDAY...WITH
SEASONABLE TEMPS AND LOWER HUMIDITY. TEMPS MAY CLIMB A FEW DEGREES
FROM WEDNESDAY TO THURSDAY AS WARM ADVECTION/RETURN FLOW KICKS IN.
FOR FRIDAY AND SATURDAY...OPERATIONAL MODELS KEEP THE AREA ON THE
EDGE OF THE UPPER RIDGE/HOT DOME CENTERED ACROSS THE ROCKIES/HIGH
PLAINS...IN THE VICINITY OF THE STRONGER WESTERLIES. UPPER LEVEL
IMPULSES SKIRTING ALONG THE PERIPHERY OF THE RIDGE WILL HELP TO
TRIGGER SCATTERED CONVECTION...BUT THE TIMING AND AMPLITUDE OF THESE
DISTURBANCE IS NOT CLEAR THIS FAR OUT...SO WILL CONTINUE LOW-END POPS
FRIDAY INTO SATURDAY. TEMPS TOWARDS NEXT WEEKEND CONTINUE TO LOOK
SEASONABLE OVERALL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 644 AM CDT SUN JUL 7 2013
PATCHY FOG HAS BROUGHT IFR OR LOWER CONDITIONS TO ALL BUT
KDVL...WITH KBJI SEEING 1/4 TO 1/2SM FOR THE PAST FEW HOURS. THINK
THAT THE REDUCED VIS WILL CONTINUE THROUGH THE NEXT HOUR OR SO IN
THE RED RIVER VALLEY...AND A BIT LONGER AT KBJI. THERE SHOULD BE
SOME GRADUAL IMPROVEMENT TO MVFR VIS AND THEN ALL SITES SHOULD BE
VFR AFTER 16Z. WINDS WILL SHIFT TO THE NORTHWEST BY LATE MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 AM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 621 AM CDT SUN JUL 7 2013
SHORTWAVE TROUGH MOVING THROUGH EASTERN MONTANA AT THIS TIME
GENERATING SEVERAL CLUSTERS OF THUNDERSTORMS. THE CONVECTION ALSO
SUPPORTED BY 75-90 KT ANTICYCLONICALLY CURVED H250 JET ACROSS
SOUTHEAST MANITOBA. FOCUSED ON THIS AREA FOR THE MORNING UPDATE. SO
RAISED THE CHANCE FOR THUNDERSTORMS SOUTHWEST. THIS EARLY
CONVECTION NOT EXPECTED TO BE SEVERE. WAITING FOR BETTER
INSTABILITY...STEEPER MID LEVEL LAPSE RATES AND BETTER CAPE THIS
AFTERNOON. BUT ISOLATED HAIL/GUSTY WIND POSSIBLE THIS MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN JUL 7 2013
EARLY MORNING SURFACE ANALYSIS PLACED A WEAK SURFACE TROUGH ACROSS
EASTERN NORTH DAKOTA. THE TROUGH WAS THE FOCUS FOR ISOLATED
THUNDERSTORMS EARLIER THIS MORNING...BUT THEY HAVE SINCE
DIMINISHED. THE TROUGH WILL MOVE SLOWLY EAST THIS MORNING...TAKING
THE THREAT OF ADDITIONAL THUNDERSTORMS WITH IT.
THE NEXT CONCERN WILL BE SHOWERS / THUNDERSTORMS IN EASTERN
MONTANA WHICH HAVE BEEN MAKING STEADY PROGRESS TOWARDS WESTERN
NORTH DAKOTA EARLY THIS MORNING. THE STORMS IN EASTERN MONTANA ARE
IN PART BEING DRIVEN BY A SHORT WAVE WHICH IS EXPECTED TO MOVE
INTO WESTERN NORTH DAKOTA THIS MORNING...AND INTO CENTRAL NORTH
DAKOTA THIS AFTERNOON. VARIOUS MODEL SOLUTIONS (NAM / RAP / GFS /
4KM WRF) ALL SUGGEST THERE WILL BE A CHANCE OF PRECIPITATION AS
THE WAVE MOVES ACROSS THE FORECAST AREA. WHERE THEY DIFFER TO SOME
EXTENT IS IN THEIR COVERAGE OF PRECIPITATION. WILL HOLD ONTO
CHANCE POPS ACROSS MOST OF THE FORECAST AREA TODAY / THIS EVENING
WITH THE HIGHER POPS IN THE WEST. THE LATEST DAY 1 OUTLOOK PLACES
THE SOUTHWEST PART OF THE STATE IN A SLIGHT RISK...WHICH APPEARS
REASONABLE SINCE THAT AREA IS FORECAST TO HAVE THE GREATEST
INSTABILITY THIS AFTERNOON / EVENING WITH MLCAPE VALUES OF UP TO
1500 J/KG.
CONFIDENCE IN THUNDERSTORM COVERAGE LATE TONIGHT INTO EARLY MONDAY
MORNING DECREASES TO SOME EXTENT AS THE INITIAL WAVE MOVES EAST.
CONFLICTING SIGNALS ARE SHOWN IN THE MODEL SOLUTIONS WITH SOME
SUGGESTING LIMITED THUNDERSTORM COVERAGE OVERNIGHT...WHILE OTHERS
BRING ADDITIONAL THUNDERSTORMS INTO WESTERN NORTH DAKOTA FROM
EASTERN MONTANA. WILL HOLD ONTO CHANCE POPS IN THE CENTRAL AND
WEST...WITH SLIGHT CHANCES IN THE EAST WHERE CONFIDENCE IN
ADDITIONAL CONVECTION IS LOWER.
CLOUDS FROM SHOWERS / THUNDERSTORMS COULD INFLUENCE TEMPERATURES
TODAY. WILL FOLLOW A BLEND OF GUIDANCE VALUES WITH HIGHS NEAR 80
NORTH...AND LOWER TO MID 80S SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 7 2013
MODELS AGREE IN A SOUTHWEST FLOW ALOFT FROM THE NORTHWEST US TO
THE NORTHERN PLAINS EARLY IN THE PERIOD. AN ACTIVE SHORTWAVE
PATTERN WILL BRING SEVERAL SHORTWAVES THROUGH THE REGION BRINGING
SOME WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION MONDAY
NIGHT AND TUESDAY. THIS WILL BE FOLLOWED BY A BREAK IN THE
PRECIPITATION CHANCES WEDNESDAY AND THURSDAY AS AN H500 RIDGE
POSITIONS ITSELF OVER THE NORTHERN PLAINS. AS THIS FEATURE MOVES
EAST BY NEXT WEEKEND WILL SEE AT LEAST A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS RETURN FOR FRIDAY AND SATURDAY.
THE PRIMARY FOCUS WILL BE MONDAY NIGHT. BY MONDAY AFTERNOON LOW
PRESSURE WILL DEVELOP ACROSS MONTANA BRINGING A EASTERLY WIND FLOW
ACROSS WEST AND CENTRAL NORTH DAKOTA. THIS WILL PULL ABUNDANT
MOISTURE INTO THE REGION. MODEL SOUNDINGS FORECAST PWATS BETWEEN
1.5 AND 1.75 INCHES...OR ROUGHLY 2 STANDARD DEVIATIONS ABOVE
NORMAL IF CORRECT. WITH ABUNDANT MOISTURE WILL MENTION HEAVY RAIN
IN THE HWO ALONG WITH SLIGHT CHANCE SEVERE FROM SPC MONDAY NIGHT.
THUNDERSTORMS WILL END TUESDAY FOLLOWED BY THE DRY WEATHER
WEDNESDAYS AND THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 621 AM CDT SUN JUL 7 2013
AT 6 AM CDT...A WEAK UPPER LEVEL DISTURBANCE WAS MOVING THROUGH
EASTERN MONTANA AND WESTERN NORTH DAKOTA. A MOIST UNSTABLE AIR
REMAINED ACROSS THE STATE. SCATTERED MORNING THUNDERSTORMS ARE
POSSIBLE WEST. THIS WILL HAVE IMPACTS TO KDIK. MENTIONS VCTS AT
FOR THE MORNING. OTHERWISE VFR AT ALL TAF SITES. ANOTHER ROUND OF
THUNDERSTORMS ARE POSSIBLE LATER THIS AFTERNOON AND THIS EVENING.
ALTHOUGH HIGHER IMPACTS EXPECTED TO THE SOUTHWEST...INCLUDING
KDIK...DID NOT MENTION FOR KDIK TAF...AS UNCERTAINTY ON TIMING
AND AREA TO GREAT TO MENTION AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CK
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
344 AM CDT SUN JUL 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT SUN JUL 7 2013
EARLY MORNING SURFACE ANALYSIS PLACED A WEAK SURFACE TROUGH ACROSS
EASTERN NORTH DAKOTA. THE TROUGH WAS THE FOCUS FOR ISOLATED
THUNDERSTORMS EARLIER THIS MORNING...BUT THEY HAVE SINCE
DIMINISHED. THE TROUGH WILL MOVE SLOWLY EAST THIS MORNING...TAKING
THE THREAT OF ADDITIONAL THUNDERSTORMS WITH IT.
THE NEXT CONCERN WILL BE SHOWERS / THUNDERSTORMS IN EASTERN
MONTANA WHICH HAVE BEEN MAKING STEADY PROGRESS TOWARDS WESTERN
NORTH DAKOTA EARLY THIS MORNING. THE STORMS IN EASTERN MONTANA ARE
IN PART BEING DRIVEN BY A SHORT WAVE WHICH IS EXPECTED TO MOVE
INTO WESTERN NORTH DAKOTA THIS MORNING...AND INTO CENTRAL NORTH
DAKOTA THIS AFTERNOON. VARIOUS MODEL SOLUTIONS (NAM / RAP / GFS /
4KM WRF) ALL SUGGEST THERE WILL BE A CHANCE OF PRECIPITATION AS
THE WAVE MOVES ACROSS THE FORECAST AREA. WHERE THEY DIFFER TO SOME
EXTENT IS IN THEIR COVERAGE OF PRECIPITATION. WILL HOLD ONTO
CHANCE POPS ACROSS MOST OF THE FORECAST AREA TODAY / THIS EVENING
WITH THE HIGHER POPS IN THE WEST. THE LATEST DAY 1 OUTLOOK PLACES
THE SOUTHWEST PART OF THE STATE IN A SLIGHT RISK...WHICH APPEARS
REASONABLE SINCE THAT AREA IS FORECAST TO HAVE THE GREATEST
INSTABILITY THIS AFTERNOON / EVENING WITH MLCAPE VALUES OF UP TO
1500 J/KG.
CONFIDENCE IN THUNDERSTORM COVERAGE LATE TONIGHT INTO EARLY MONDAY
MORNING DECREASES TO SOME EXTENT AS THE INITIAL WAVE MOVES EAST.
CONFLICTING SIGNALS ARE SHOWN IN THE MODEL SOLUTIONS WITH SOME
SUGGESTING LIMITED THUNDERSTORM COVERAGE OVERNIGHT...WHILE OTHERS
BRING ADDITIONAL THUNDERSTORMS INTO WESTERN NORTH DAKOTA FROM
EASTERN MONTANA. WILL HOLD ONTO CHANCE POPS IN THE CENTRAL AND
WEST...WITH SLIGHT CHANCES IN THE EAST WHERE CONFIDENCE IN
ADDITIONAL CONVECTION IS LOWER.
CLOUDS FROM SHOWERS / THUNDERSTORMS COULD INFLUENCE TEMPERATURES
TODAY. WILL FOLLOW A BLEND OF GUIDANCE VALUES WITH HIGHS NEAR 80
NORTH...AND LOWER TO MID 80S SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 7 2013
MODELS AGREE IN A SOUTHWEST FLOW ALOFT FROM THE NORTHWEST US TO
THE NORTHERN PLAINS EARLY IN THE PERIOD. AN ACTIVE SHORTWAVE
PATTERN WILL BRING SEVERAL SHORTWAVES THROUGH THE REGION BRINGING
SOME WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE REGION MONDAY
NIGHT AND TUESDAY. THIS WILL BE FOLLOWED BY A BREAK IN THE
PRECIPITATION CHANCES WEDNESDAY AND THURSDAY AS AN H500 RIDGE
POSITIONS ITSELF OVER THE NORTHERN PLAINS. AS THIS FEATURE MOVES
EAST BY NEXT WEEKEND WILL SEE AT LEAST A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS RETURN FOR FRIDAY AND SATURDAY.
THE PRIMARY FOCUS WILL BE MONDAY NIGHT. BY MONDAY AFTERNOON LOW
PRESSURE WILL DEVELOP ACROSS MONTANA BRINGING A EASTERLY WIND FLOW
ACROSS WEST AND CENTRAL NORTH DAKOTA. THIS WILL PULL ABUNDANT
MOISTURE INTO THE REGION. MODEL SOUNDINGS FORECAST PWATS BETWEEN
1.5 AND 1.75 INCHES...OR ROUGHLY 2 STANDARD DEVIATIONS ABOVE
NORMAL IF CORRECT. WITH ABUNDANT MOISTURE WILL MENTION HEAVY RAIN
IN THE HWO ALONG WITH SLIGHT CHANCE SEVERE FROM SPC MONDAY NIGHT.
THUNDERSTORMS WILL END TUESDAY FOLLOWED BY THE DRY WEATHER
WEDNESDAYS AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 345 AM CDT SUN JUL 7 2013
WILL CARRY A VFR FORECAST AT THE TERMINAL LOCATIONS...BUT THERE
ARE A FEW CONCERNS. THE PRIMARY ISSUE WILL BE THE CHANCE OF
THUNDERSTORMS...ESPECIALLY NEAR KDIK LATER THIS MORNING AS SHOWERS
/THUNDERSTORMS ACROSS EASTERN MONTANA MOVE EAST INTO WESTERN NORTH
DAKOTA. CONFIDENCE IS NOT HIGH ENOUGH FOR A TEMPO GROUP...SO WILL
CARRY VCTS FOR NOW AND MONITOR THE TRENDS. THE REMAINDER OF THE
TAF LOCATIONS APPEAR TO HAVE LESSER CHANCES FOR THUNDERSTORMS THAN
KDIK...SO WILL NOT MENTION THEM AT THOSE TERMINALS. WINDS WILL
STAY RELATIVELY LIGHT THROUGH THE FORECAST PERIOD AT SPEEDS OF
LESS THAN 10 KTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CK
LONG TERM...WAA
AVIATION...CK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1159 PM EDT MON JUL 8 2013
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN A CONTINUED
CHANCE OF THUNDERSTORMS THROUGH MID WEEK. A COLD FRONT WILL PUSH
THROUGH THE AREA WEDNESDAY NIGHT. BUILDING HIGH PRESSURE IN THE
UPPER MIDWEST BEHIND THE FRONT WILL BRING DRIER CONDITIONS FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HAVE BECOME INCREASINGLY CONCERNED ABOUT HEAVY RAIN/FLASH FLOOD
POTENTIAL FOR THE OVERNIGHT HOURS ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. MODELS ARE SHOWING A LOW LEVEL JET ACROSS NORTHERN
OHIO THAT KEEPS AN AXIS OF MOISTURE TRANSPORT ACROSS THE REGION
THROUGH THE NIGHT. GUIDANCE HAS BEEN DEVELOPING AN EAST-WEST LINE
OF PRECIPITATION WHICH ONCE IT SETS UP MAY NOT MOVE MUCH AS IT
BECOMES PARALLEL TO THE 0-3 KM SHEAR VECTOR. ALTHOUGH IT SHOULD BE
NOTED THAT SOME RECENT RUNS OF THE HRRR AND RAP SUGGEST THAT THE
CONVECTIVE LINE MAY BE ABLE TO SAG SOUTH. ALSO THE WARM CLOUD
DEPTH IS DEEP WHICH WILL MAKE FOR VERY EFFICIENT RAINFALL
PRODUCTION. SOME OF THE REGION ALREADY HAD HEAVY RAINFALL EARLY
MONDAY MORNING WHICH SATURATED THE GROUND. ALL OF THIS SUGGESTS
THAT THERE IS A SUBSTANTIAL THREAT OF FLASH FLOODING AND IT IS
POSSIBLE THAT SOME LOCATIONS COULD SEE SIGNIFICANT IMPACTS
OVERNIGHT. THUS HAVE EXPANDED THE FLASH FLOOD WATCH BACK WEST TO
INCLUDE MOST OF THE MIAMI VALLEY AND PARTS OF THE WHITEWATER
VALLEY.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MODELS ARE IN DISAGREEMENT WITH THE EVOLUTION OF THE RAIN FROM
TONIGHT. CANNOT REMOVE A CHANCE FOR THUNDERSTORMS IN AN AIRMASS
THAT HAS BEEN EXTREMELY SUPPORTIVE OF THEM FOR THE PAST WEEK OR
MORE. HEAVY RAIN WILL BE A POSSIBILITY WITH ANY OF THESE
STORMS...AND THE CHANCES WILL REALLY INCREASE LATE WEDNESDAY AND
OVERNIGHT AS A DISTINCT COLD FRONT WITH UPPER LEVEL SUPPORT
CROSSES THE AREA. UNTIL THIS TIME...MORE OF THE SAME IS EXPECTED
AND HIGHS WILL GRADUALLY CREEP UPWARDS A DEGREE OR TWO EACH DAY.
NIGHTTIME LOWS WILL ONLY BE MITIGATED TO BE COOLER FROM STORMS
THAT MAY OR MAY NOT BE PRESENT AT TIMES...AT LEAST TUESDAY NIGHT.
OUTSIDE OF THE STORMS...THE AIRMASS WILL RETAIN HIGH DEWPOINTS AND
LIMIT NIGHTTIME DROPOFFS MUCH BELOW 70 DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
REGION WILL FIND ITSELF SPLIT BY A CDFNT AT THE BEGINNING OF THE
PERIOD. THE FRONT WILL BE LOCATED NEAR THE OHIO RIVER AT 12Z
THURSDAY. MODELS QUICKLY PUSH THE FRONT INTO THE APPALACHIANS AND
REPLACE IT WITH HIGH PRESSURE. THIS SHOULD MEAN SOME LINGERING
CONVECTION FOR THE MORNING HOURS OF THURSDAY IN THE EXTREME
SOUTH...WITH DRY CONDITIONS FOR THE N. MODELS DROP AN H5 S/W INTO
LAKE ERIE THURSDAY AFTN...BUT RIGHT NOW IT APPEARS THAT THE S/W WILL
PRODUCE JUST SOME AFTN CLOUDS AND NOT ANY AFTN SHOWERS.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND WILL HOLD CONTROL
INTO SATURDAY NIGHT. THIS SHOULD ALLOW THE REGION TO BEGIN TO DRY
OUT.
RETURN FLOW BY SUNDAY WILL BRING THE RETURN OF SCT CONVECTION FOR
SUNDAY AND MONDAY. WENT WITH LOW CHC POPS FOR NOW.
HIGHS THURSDAY INTO SATURDAY WILL BE A FEW DEGREES EITHER SIDE OF 80
FOR THE REGION. BY SUNDAY AND MONDAY...HIGHS WILL RISE INTO THE
LOWER 80S. LOWS WILL BE IN THE LOWER 60S FOR THE FIRST HALF OF THE
PERIOD...THEN THE MID 60S FOR THE LATER HALF.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHOWERS AND POSSIBLY SOME EMBEDDED THUNDERSTORMS WILL IMPACT THE
NORTHERN TERMINALS OVERNIGHT. AT THIS POINT HAVE KEPT THE TAFS
FAIRLY GENERIC WITH MVFR CONDITIONS AT WORST. BUT SOME OF THE
SHOWERS COULD PRODUCE HEAVY DOWNPOURS AND TEMPORARY IFR
VISIBILITIES. WILL MONITOR AND AMEND IF IT BECOMES APPARENT THAT
HEAVIER RAINFALL/LOWER CONDITIONS MAY IMPACT ANY OF THE TERMINALS.
AT THIS POINT IT SEEMS THAT MOST IF NOT ALL OF THE PRECIPITATION
WILL STAY NORTH OF THE CINCINNATI AIRPORTS THROUGH THE NIGHT. THE
CHANCE OF ADDITIONAL SHOWERS OR THUNDERSTORMS DURING THE DAY WILL
DEPEND AT LEAST IN PART ON HOW PRECIPITATION EVOLVES OVERNIGHT.
WITH PLENTY OF UNCERTAINTY HAVE JUST INCLUDED SOME VCSH ALONG WITH
VFR CONDITIONS.
OUTLOOK...GOOD CHANCE OF THUNDERSTORMS WEDNESDAY AND WEDNESDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 10 AM EDT TUESDAY FOR OHZ026-034-035-
042>046-051>056-060>065-073-074.
KY...NONE.
IN...FLASH FLOOD WATCH UNTIL 10 AM EDT TUESDAY FOR INZ050-058-059.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
912 PM EDT MON JUL 8 2013
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN A CONTINUED
CHANCE OF THUNDERSTORMS THROUGH MID WEEK. A COLD FRONT WILL PUSH
THROUGH THE AREA WEDNESDAY NIGHT. BUILDING HIGH PRESSURE IN THE
UPPER MIDWEST BEHIND THE FRONT WILL BRING DRIER CONDITIONS FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HAVE BECOME INCREASINGLY CONCERNED ABOUT HEAVY RAIN/FLASH FLOOD
POTENTIAL FOR THE OVERNIGHT HOURS ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. MODELS ARE SHOWING A LOW LEVEL JET ACROSS NORTHERN
OHIO THAT KEEPS AN AXIS OF MOISTURE TRANSPORT ACROSS THE REGION
THROUGH THE NIGHT. GUIDANCE HAS BEEN DEVELOPING AN EAST-WEST LINE
OF PRECIPITATION WHICH ONCE IT SETS UP MAY NOT MOVE MUCH AS IT
BECOMES PARALLEL TO THE 0-3 KM SHEAR VECTOR. ALTHOUGH IT SHOULD BE
NOTED THAT SOME RECENT RUNS OF THE HRRR AND RAP SUGGEST THAT THE
CONVECTIVE LINE MAY BE ABLE TO SAG SOUTH. ALSO THE WARM CLOUD
DEPTH IS DEEP WHICH WILL MAKE FOR VERY EFFICIENT RAINFALL
PRODUCTION. SOME OF THE REGION ALREADY HAD HEAVY RAINFALL EARLY
MONDAY MORNING WHICH SATURATED THE GROUND. ALL OF THIS SUGGESTS
THAT THERE IS A SUBSTANTIAL THREAT OF FLASH FLOODING AND IT IS
POSSIBLE THAT SOME LOCATIONS COULD SEE SIGNIFICANT IMPACTS
OVERNIGHT. THUS HAVE EXPANDED THE FLASH FLOOD WATCH BACK WEST TO
INCLUDE MOST OF THE MIAMI VALLEY AND PARTS OF THE WHITEWATER
VALLEY.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
MODELS ARE IN DISAGREEMENT WITH THE EVOLUTION OF THE RAIN FROM
TONIGHT. CANNOT REMOVE A CHANCE FOR THUNDERSTORMS IN AN AIRMASS
THAT HAS BEEN EXTREMELY SUPPORTIVE OF THEM FOR THE PAST WEEK OR
MORE. HEAVY RAIN WILL BE A POSSIBILITY WITH ANY OF THESE
STORMS...AND THE CHANCES WILL REALLY INCREASE LATE WEDNESDAY AND
OVERNIGHT AS A DISTINCT COLD FRONT WITH UPPER LEVEL SUPPORT
CROSSES THE AREA. UNTIL THIS TIME...MORE OF THE SAME IS EXPECTED
AND HIGHS WILL GRADUALLY CREEP UPWARDS A DEGREE OR TWO EACH DAY.
NIGHTTIME LOWS WILL ONLY BE MITIGATED TO BE COOLER FROM STORMS
THAT MAY OR MAY NOT BE PRESENT AT TIMES...AT LEAST TUESDAY NIGHT.
OUTSIDE OF THE STORMS...THE AIRMASS WILL RETAIN HIGH DEWPOINTS AND
LIMIT NIGHTTIME DROPOFFS MUCH BELOW 70 DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
REGION WILL FIND ITSELF SPLIT BY A CDFNT AT THE BEGINNING OF THE
PERIOD. THE FRONT WILL BE LOCATED NEAR THE OHIO RIVER AT 12Z
THURSDAY. MODELS QUICKLY PUSH THE FRONT INTO THE APPALACHIANS AND
REPLACE IT WITH HIGH PRESSURE. THIS SHOULD MEAN SOME LINGERING
CONVECTION FOR THE MORNING HOURS OF THURSDAY IN THE EXTREME
SOUTH...WITH DRY CONDITIONS FOR THE N. MODELS DROP AN H5 S/W INTO
LAKE ERIE THURSDAY AFTN...BUT RIGHT NOW IT APPEARS THAT THE S/W WILL
PRODUCE JUST SOME AFTN CLOUDS AND NOT ANY AFTN SHOWERS.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND WILL HOLD CONTROL
INTO SATURDAY NIGHT. THIS SHOULD ALLOW THE REGION TO BEGIN TO DRY
OUT.
RETURN FLOW BY SUNDAY WILL BRING THE RETURN OF SCT CONVECTION FOR
SUNDAY AND MONDAY. WENT WITH LOW CHC POPS FOR NOW.
HIGHS THURSDAY INTO SATURDAY WILL BE A FEW DEGREES EITHER SIDE OF 80
FOR THE REGION. BY SUNDAY AND MONDAY...HIGHS WILL RISE INTO THE
LOWER 80S. LOWS WILL BE IN THE LOWER 60S FOR THE FIRST HALF OF THE
PERIOD...THEN THE MID 60S FOR THE LATER HALF.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SHOWERS AND POSSIBLY SOME EMBEDDED THUNDERSTORMS WILL IMPACT THE
NORTHERN TERMINALS OVERNIGHT. AT THIS POINT HAVE KEPT THE TAFS
FAIRLY GENERIC WITH MVFR CONDITIONS AT WORST. BUT SOME OF THE
SHOWERS COULD PRODUCE HEAVY DOWNPOURS AND TEMPORARY IFR
VISIBILITIES. WILL MONITOR AND AMEND IF IT BECOMES APPARENT THAT
HEAVIER RAINFALL/LOWER CONDITIONS MAY IMPACT ANY OF THE TERMINALS.
AT THIS POINT IT SEEMS THAT MOST IF NOT ALL OF THE PRECIPITATION
WILL STAY NORTH OF THE CINCINNATI AIRPORTS THROUGH THE NIGHT. THE
CHANCE OF ADDITIONAL SHOWERS OR THUNDERSTORMS DURING THE DAY WILL
DEPEND AT LEAST IN PART ON HOW PRECIPITATION EVOLVES OVERNIGHT.
WITH PLENTY OF UNCERTAINTY HAVE JUST INCLUDED SOME VCSH ALONG WITH
VFR CONDITIONS.
OUTLOOK...GOOD CHANCE OF THUNDERSTORMS WEDNESDAY AND WEDNESDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR OHZ026-034-035-
042>046-051>056-060>062.
KY...NONE.
IN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR INZ050-058-059.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
559 PM EDT SUN JUL 7 2013
.SYNOPSIS...
UPPER LEVEL LOW MOVES EAST TONIGHT. NORTHWEST FLOW THROUGH
WEDNESDAY BRINGS MORE CONVECTION. A COLD FRONT PUSHES SOUTHEAST
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
CLOUDS HAVE PREVENTED MUCH ENERGY FROM BUILDING UP IN AREAS THAT
STILL HAVE DEEPER MOISTURE. THEREFORE...SHOWERS ARE ONLY PRODUCING
UP TO HALF AN INCH OF RAINFALL. WILL CANCEL FLASH FLOOD WATCH.
&&
.SHORT TERM /MIDNIGHT TONIGHT THROUGH WEDNESDAY/...
MODELS CONTINUE TO ADVERTISE THAT WEST/NORTHWEST UPPER FLOW WILL
DEVELOP WITH UPPER DISTURBANCES EXPECTED TO MOVE ACROSS THE AREA.
AT THE SURFACE...WEAK HIGH PRESSURE WILL GIVE WAY...ALLOWING A
COLD FRONT TO APPROACH LATE.
THE COMBINATION OF UPPER DISTURBANCES AND GULF MOISTURE WILL RESULT
IN ON AND OFF AGAIN SHOWER AND STORM CHANCES WITH THUNDERSTORM
COMPLEXES ROLLING FROM NORTHWEST TO SOUTHEAST REMAINING POSSIBLE.
AS FRONT BEGINS TO APPROACH FROM THE NORTHWEST ON WEDNESDAY...SHOWER
AND STORMS CHANCES SHOULD RAMP UP...AND HAVE INCLUDED LIKELY POPS
ACROSS OUR SOUTHEAST OHIO COUNTIES FOR WEDNESDAY AFTERNOON.
MAX TEMPERATURES WILL BE NEAR NORMAL...BUT IT WILL BE RATHER HUMID.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING FOR THIS PORTION OF THE FORECAST...
WITH SOME TWEAKS.
COLD FRONT IS EXPECTED TO PUSH SOUTHEAST WEDNESDAY NIGHT AND
THURSDAY...WITH WEAK HIGH PRESSURE SLIDING BY TO OUR NORTH FRIDAY
THROUGH SUNDAY. GFS/ECMWF BOTH ADVERTISE AN UPPER LOW WILL DEVELOP
FRIDAY NIGHT...WITH A TROF EXTENDING SOUTHWEST ACROSS THE REGION.
A SECOND UPPER LOW IS EXPECTED TO DEVELOP TO OUR SOUTH ON SATURDAY
AND THEN RETROGRADE WITH TIME.
COMBINATION OF COLD FRONT AND THE UPPER LOWS SUGGEST ANOTHER
EXTENDED PERIOD OF WET WEATHER FOR MUCH OF THIS PERIOD.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
RADAR IMAGES SHOW THE BULK OF PCPN OVER THE HIGHER MOUNTAINS BY
18Z. A NEW LINE OF WEAK CONVECTION IS EVIDENT IN
RADAR...DEVELOPING OVER SOUTHEAST OH. THESE SHOWERS WILL CONTINUE
TO INCREASE INTO STORMS TO PRODUCE LIGHTNING. THE HRRR...NAM AND
RAP DEVELOP THIS LINE OVER THE OH RIVER BY 21Z...SPREADING
NORTHEAST AS IT WEAKENS BY SUNSET. THIS SECOND LINE OF CONVECTION
COULD PRODUCE IFR VISIBILITIES AND THUNDER MAINLY AT
HTS...PKB...AND CRW THROUGH 22Z THIS AFTERNOON. WITH NO LIGHTNING
OCCURRING WITH BACK EDGE OF PCPN...AND THERMODYNAMIC AND DYNAMIC
PARAMETERS INDICATED BY RAP AND NAM...KEPT THUNDER OR VCTS OVER
EASTERN SITES ALONG THE OH RIVER.
WATER VAPOR SATELLITE IMAGES SHOW BACK EDGE OF HIGH CLOUDS MARKING
THE UPPER LEVEL JET ACROSS OH...EXTENDING SOUTH INTO NORTHEAST KY.
A CONCENTRATED DRY SLOT AROUND THE UPPER LOW SUGGESTS
STRATOSPHERIC INTRUSION AROUND THE LOW AT THE BASE...SPREADING
INTO ITS SOUTHEAST QUADRANT. THESE FEATURES SUGGEST FRONTOGENESIS
POSSIBLE AT THE MID LEVELS...THAT COULD ENHANCE THE LATER
CONVECTION TO FLARE UP INTO GUSTY THUNDERSTORMS THROUGH SUNSET.
ABUNDANT LOW LEVEL MOISTURE WILL KEEP POST RAINFALL LOW STRATUS
OVER THE WESTERN SLOPES AND EASTERN MOUNTAINS TONIGHT...WITH
CONDITIONS DETERIORATING OVERNIGHT. EXPECT IFR/LIFR STRATUS AT BKW
AND EKN AFTER 06Z THROUGH 13Z MONDAY MORNING.
CONDITIONS EXPECTED TO IMPROVE WIDESPREAD TO VFR BY 15Z MONDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND STORMS COULD VARY BY A
COUPLE HOURS. IFR/LIFR FOG OR LOW STRATUS TIMING MAY VARY
OVERNIGHT IF SKIES CLEAR FASTER THAN ANTICIPATED.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M H
HTS CONSISTENCY M H H H H H H H H M H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H M M L L
PKB CONSISTENCY M H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 00Z TUESDAY...
IFR FOG POSSIBLE LATE SUNDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/ARJ
NEAR TERM...RPY
SHORT TERM...JSH
LONG TERM...JSH
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
237 PM EDT SUN JUL 7 2013
.SYNOPSIS...
UPPER LEVEL LOW MOVES EAST TONIGHT. NORTHWEST FLOW THROUGH
WEDNESDAY BRINGS MORE CONVECTION. A COLD FRONT PUSHES SOUTHEAST
WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
HRRR...RAP AND NAM MODELS SHOW A WEAK LINE OF CONVECTION
DEVELOPING ACROSS THE OH VALLEY...SPREADING NORTHEAST AND
WEAKENING BY SUNSET. FLASH FLOOD WATCH CONTINUES IN EFFECT FOR THE
MOST PART...EXCEPT FOR SOUTHEAST OH...AND FEW COUNTIES IN
NORTHEAST KY.
UPPER LOW CROSSING THE IN AND OH BORDER EVIDENT IN WATER VAPOR
IMAGES WILL CONTINUE ITS TRAJECTORY EAST INTO OH AND WV OVERNIGHT
INTO MONDAY. THE LEADING EDGE OF UPPER/MID CLOUDS ASSOCIATED WITH
UPPER LEVEL JET WILL SPREAD AREAS OF CLEARING FROM NORTHEAST
KY...EAST ACROSS SOUTHEAST OH AND PORTIONS OF WV TONIGHT. THIS
CLEARING IS SUGGESTED BY THE NAM/CMC AND AT SOME DEGREE THE GMOS.
WIDESPREAD DENSE FOG POSSIBLE OVER AREAS WHERE SKY CLEARS
OVERNIGHT AS ANTECEDENT PCPN WAS WIDESPREAD AND AMPLE LOW LEVEL
MOISTURE WITH DEWPOINTS IN THE MID TO UPPER 60S. MODELS SHOW
BOUNDARY LAYER WINDS AROUND 10 KNOTS TONIGHT INTO MONDAY.
WENT CLOSER TO MAX DEWPOINTS DURING THE AFTERNOON HOURS FOR LOWS
TONIGHT. BIAS CORRECTED USED FOR HIGHS ON MONDAY...GENERALLY IN
THE LOWER 80S LOWLANDS...RANGING TO THE MID 70S HIGHEST
ELEVATIONS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MODELS CONTINUE TO ADVERTISE THAT WEST/NORTHWEST UPPER FLOW WILL
DEVELOP WITH UPPER DISTURBANCES EXPECTED TO MOVE ACROSS THE AREA.
AT THE SURFACE...WEAK HIGH PRESSURE WILL GIVE WAY...ALLOWING A
COLD FRONT TO APPROACH LATE.
THE COMBINATION OF UPPER DISTURBANCES AND GULF MOISTURE WILL RESULT
IN ON AND OFF AGAIN SHOWER AND STORM CHANCES WITH THUNDERSTORM
COMPLEXES ROLLING FROM NORTHWEST TO SOUTHEAST REMAINING POSSIBLE.
AS FRONT BEGINS TO APPROACH FROM THE NORTHWEST ON WEDNESDAY...SHOWER
AND STORMS CHANCES SHOULD RAMP UP...AND HAVE INCLUDED LIKELY POPS
ACROSS OUR SOUTHEAST OHIO COUNTIES FOR WEDNESDAY AFTERNOON.
MAX TEMPERATURES WILL BE NEAR NORMAL...BUT IT WILL BE RATHER HUMID.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
GENERALLY FOLLOWED WPC THINKING FOR THIS PORTION OF THE FORECAST...
WITH SOME TWEAKS.
COLD FRONT IS EXPECTED TO PUSH SOUTHEAST WEDNESDAY NIGHT AND
THURSDAY...WITH WEAK HIGH PRESSURE SLIDING BY TO OUR NORTH FRIDAY
THROUGH SUNDAY. GFS/ECMWF BOTH ADVERTISE AN UPPER LOW WILL DEVELOP
FRIDAY NIGHT...WITH A TROF EXTENDING SOUTHWEST ACROSS THE REGION.
A SECOND UPPER LOW IS EXPECTED TO DEVELOP TO OUR SOUTH ON SATURDAY
AND THEN RETROGRADE WITH TIME.
COMBINATION OF COLD FRONT AND THE UPPER LOWS SUGGEST ANOTHER
EXTENDED PERIOD OF WET WEATHER FOR MUCH OF THIS PERIOD.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
RADAR IMAGES SHOW THE BULK OF PCPN OVER THE HIGHER MOUNTAINS BY
18Z. A NEW LINE OF WEAK CONVECTION IS EVIDENT IN
RADAR...DEVELOPING OVER SOUTHEAST OH. THESE SHOWERS WILL CONTINUE
TO INCREASE INTO STORMS TO PRODUCE LIGHTNING. THE HRRR...NAM AND
RAP DEVELOP THIS LINE OVER THE OH RIVER BY 21Z...SPREADING
NORTHEAST AS IT WEAKENS BY SUNSET. THIS SECOND LINE OF CONVECTION
COULD PRODUCE IFR VISIBILITIES AND THUNDER MAINLY AT
HTS...PKB...AND CRW THROUGH 22Z THIS AFTERNOON. WITH NO LIGHTNING
OCCURRING WITH BACK EDGE OF PCPN...AND THERMODYNAMIC AND DYNAMIC
PARAMETERS INDICATED BY RAP AND NAM...KEPT THUNDER OR VCTS OVER
EASTERN SITES ALONG THE OH RIVER.
WATER VAPOR SATELLITE IMAGES SHOW BACK EDGE OF HIGH CLOUDS MARKING
THE UPPER LEVEL JET ACROSS OH...EXTENDING SOUTH INTO NORTHEAST KY.
A CONCENTRATED DRY SLOT AROUND THE UPPER LOW SUGGESTS
STRATOSPHERIC INTRUSION AROUND THE LOW AT THE BASE...SPREADING
INTO ITS SOUTHEAST QUADRANT. THESE FEATURES SUGGEST FRONTOGENESIS
POSSIBLE AT THE MID LEVELS...THAT COULD ENHANCE THE LATER
CONVECTION TO FLARE UP INTO GUSTY THUNDERSTORMS THROUGH SUNSET.
ABUNDANT LOW LEVEL MOISTURE WILL KEEP POST RAINFALL LOW STRATUS
OVER THE WESTERN SLOPES AND EASTERN MOUNTAINS TONIGHT...WITH
CONDITIONS DETERIORATING OVERNIGHT. EXPECT IFR/LIFR STRATUS AT BKW
AND EKN AFTER 06Z THROUGH 13Z MONDAY MORNING.
CONDITIONS EXPECTED TO IMPROVE WIDESPREAD TO VFR BY 15Z MONDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND STORMS COULD VARY BY A
COUPLE HOURS. IFR/LIFR FOG OR LOW STRATUS TIMING MAY VARY
OVERNIGHT IF SKIES CLEAR FASTER THAN ANTICIPATED.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M H
HTS CONSISTENCY M H H H H H H H H M H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H M M L L
PKB CONSISTENCY M H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z MONDAY...
IFR FOG POSSIBLE LATE SUNDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR WVZ005>011-
013>020-024>040-046-047.
OH...NONE.
KY...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR KYZ103-105.
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...JSH/ARJ
NEAR TERM...ARJ
SHORT TERM...JSH
LONG TERM...JSH
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
624 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SEVERE THREAT WINDING DOWN RAPIDLY ACROSS FAR EASTERN PORTIONS OF
MY CWA. MODERATE SHOWERS CONTINUE OVER EASTERN HALF IN THE COLD
POOL AND WILL TAKE A FEW MORE HOURS TO DISSIPATE AND PROPOGATE
EASTWARD. ISOLATED ACTIVITY WILL STILL BE POSSIBLE FROM LATE
EVENING OVERNIGHT. ANOTHER MUGGY NIGHT IS IN STORE WITH AREAS OF
RIVER VALLEY FOG MORE PREVALENT THAT RECENT MORNINGS DUE TO
WIDESPREAD NATURE OF THIS AFTERNOON`S CONVECTION. MINS WILL RANGE
FROM THE LOWER 60S NORTHWEST TO THE LOWER 70S SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH 6 PM MONDAY/...
SHORT RANGE GUIDANCE AGREES IN TRACKING THE REMNANTS OF THE
AMAZINGLY PERSISTENT UPPER LOW/TROF THROUGH THE REGION OVERNIGHT
AND EARLY MONDAY. THIS SYSTEM HAS ACTED AS A MOISTURE PUMP INTO
THE NE US FOR OVER A WEEK AND ITS DEMISE WILL MARK A TRANSITION
TO MORE OF A ZONAL FLOW ALOFT TO START THE NEW WORK WEEK.
THE BEST FORCING WITH THE UPPER LOW IS EXPECTED TO PASS LATER
TONIGHT...DURING THE NORMAL DIURNAL LULL IN INSTABILITY. IT WILL
LIKELY KEEP A BETTER CHANCE OF SHOWERS GOING DEEPER INTO THE
OVERNIGHT THAN PREVIOUS NIGHTS WITH LOCALLY HEAVY RAIN LIKELY
BEING THE BIGGEST THREAT.
MONDAY WILL REMAIN WARM AND HUMID AND SCATTERED CONVECTION ONCE
AGAIN CANNOT BE RULED OUT...BUT CHANCES SHOULD BE LESS THAN RECENT
DAYS. ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST
OF THE AREA...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION SHOULD
ALL COMBINE TO LIMIT OUR INSTABILITY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
LINE OF THUNDERSTORMS...ACCOMPANIED BY BRIEF GUSTY WINDS AND IFR
VSBYS...IS PUSHING THRU THE SUSQ VALLEY AS OF 21Z. FOR MUCH OF
CENTRAL PA...EXPECT A RETURN TO VFR CONDS WITHIN A COUPLE HOURS
AFTER PASSAGE OF THUNDERSTORMS. HOWEVER...RESIDUAL LOW LVL
MOISTURE ASCENDING THE W MTNS COULD PRODUCE SOME LOW CIGS ACROSS
THE LAUREL HIGHLANDS THIS EVENING /JST REPORTING SCT009 AT 21Z AND
K2G4 REPORTING A 800FT CIG/. THE LOW CIG THREAT COULD SPREAD NORTH
ALONG THE ALLEGHENY MTNS TOWARD BFD LATE TONIGHT AS BLYR COOLS. LATEST
SREF AND RAP OUTPUT BOTH SUPPORT THIS THREAT OF IFR CONDS ACROSS
THE W MTNS. FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN
THE WET GROUND AND PARTIAL CLEARING EXPECTED OVERNIGHT.
HOWEVER...PRES GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO
PRECLUDE IFR VSBYS.
AN UPPER LVL LOW WILL PUSH EAST TOWARD PA MONDAY. THIS WILL BRING
ANOTHER HIGH PROB OF SHRA AND TSRA.
OUTLOOK...
MON...AM LOW CIGS POSS W MTNS. ISOLD THUNDERSTORM IMPACTS.
TUE-THU...AM LOW CIGS POSS W MTNS. SCT THUNDERSTORM IMPACTS
POSS...MAINLY DURING THE PM HOURS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...DEVOIR/LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
536 PM EDT SUN JUL 7 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS WILL
PERSIST INTO THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORE OF THE SAME IN STORE FOR TODAY...WARM AND HUMID WITH SHOWERS
AND THUNDERSTORMS COOKING UP WITH DAYTIME HEATING.
MODELS GENERATE THE MOST CAPE OVER EASTERN SECTIONS TODAY...IN
RESPONSE TO WHERE THE BEST SUNSHINE IS EXPECTED TO BE. THE ENTIRE
REGION WILL REMAIN IN THE TROPICAL AIRMASS ABOVE NORMAL PWATS
CONTINUE TO STREAM NORTH INTO THE AREA.
SPC DOESN/T OUTLOOK THE REGION TODAY...THOUGH WE ARE IN SEE TEXT.
THE SHEAR ALOFT IS FAIRLY IMPRESSIVE ON THE FRONT SIDE OF THE
UPPER LOW THAT IS FINALLY BEGINNING TO SHEAR OUT OF THE TN/OH
VALLEYS. AS A RESULT WE CANNOT RULE OUT SOME ISOLATED STRONGER
STORMS AS ACTIVITY INCREASES LATER THIS MORNING INTO THE
AFTERNOON. LOW LEVEL FOCUSING IS WEAK...SO WIDESPREAD ORGANIZED
ACTIVITY DOESN/T SEEM LIKELY ACROSS THE NORTH. HOWEVER...A SUBTLE
WAVE DRIFTING NORTH IN THE MID-LEVEL FLOW /YESTERDAY LOCATED IN W
NC/ WILL PROVIDE A BIT MORE FOCUSED LIFT ACROSS THE SOUTH...AND
COMBINED WITH MODERATE FLOW AND CAPE...COULD GENERATE MORE
ORGANIZED ACTIVITY WITH SOME STRONGER STORMS POSS. THIS IS ALSO
NOTED IN THE HRRR...WHICH HAS BEEN PERFORMING WELL OVER THE PAST
COUPLE OF DAYS. ACTIVITY LOOKS TO BEGIN PICKING UP AFTER 18Z IN
THE SW...AND IF SCENARIO PLAYS OUT - TRACKING EASTWARD THROUGH THE
AFTERNOON HOURS.
HIGHS TODAY LOOK LIKE THEY WILL NOT BE MUCH DIFFERENT THAN SUNDAY.
ANOTHER VERY SUMMERY EARLY JULY DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SHORT RANGE GUIDANCE AGREES IN TRACKING THE REMNANTS OF THE
AMAZINGLY PERSISTENT UPPER LOW/TROF THROUGH THE REGION OVERNIGHT
AND EARLY MONDAY. THIS SYSTEM HAS ACTED AS A MOISTURE PUMP INTO
THE NE US FOR OVER A WEEK AND ITS DEMISE WILL MARK A TRANSITION
TO MORE OF A ZONAL FLOW ALOFT TO START THE NEW WORK WEEK.
THE BEST FORCING WITH THE UPPER LOW IS EXPECTED TO PASS LATER
TONIGHT...DURING THE NORMAL DIURNAL LULL IN INSTABILITY. IT WILL
LIKELY KEEP A BETTER CHANCE OF SHOWERS GOING DEEPER INTO THE
OVERNIGHT THAN PREVIOUS NIGHTS WITH LOCALLY HEAVY RAIN LIKELY
BEING THE BIGGEST THREAT.
MONDAY WILL REMAIN WARM AND HUMID AND SCATTERED CONVECTION ONCE
AGAIN CANNOT BE RULED OUT...BUT CHANCES SHOULD BE LESS THAN RECENT
DAYS. ENSEMBLES AGREE IN SHUNTING THE AXIS OF HIGHEST PWATS EAST
OF THE AREA...AND MID LEVEL HEIGHT RISES AND WARM ADVECTION SHOULD
ALL COMBINE TO LIMIT OUR INSTABILITY.
TEMPS FROM NEAR 80 IN THE NW...TO THE MID 80S IN THE SE WILL BE
VERY CLOSE TO NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AFTER THE PASSAGE OF THE UPPER LOW...THE UPPER PATTERN WILL BECOME
QUASI-ZONAL FOR A TIME EARLY TO MID WEEK...WITH PA BEING ON THE
SOUTHERN EDGE OF THE WESTERLIES. THE MODELS ARE CONSISTENT WITH
PERSISTENT MOIST WESTERLY FLOW WHICH WILL LEAVE THE REGION
VULNERABLE TO CONVECTION AS WEAK DISTURBANCES RIPPLE EASTWARD OUT
OF THE MIDWEST AND GREAT LAKES.
A STRONGER TROUGH WILL DEEPEN OVER SOUTHERN CANADA AND OVER THE
GREAT LAKES REGION TOWARDS THE END OF THE WEEK. THIS SHOULD RESULT
IN A FAIRLY STRONG FRONTAL PASSAGE SOMETIME LATER WED OR THU AS
SLIGHTLY COOLER BUT MUCH DRIER AIR SLIDES OUT OF THE GR LAKES.
FROM THERE THE UPPER PATTERN ADVERTISED IN SOME LONGER RANGE
GUIDANCE TAKES ON A LOOK THAT IS EERILY FAMILIAR TO WHAT WE HAVE
JUST EXPERIENCED...WITH A NEW CUTOFF LOW FCST TO FORM OVER THE
EASTERN US...AND A RENEWED SURGE OF DEEP SOUTHERLY FLOW
EVENTUALLY EXPECTED TO DEVELOP ONCE AGAIN OVER THE EASTERN US. A
POTENTIAL COMPLICATING FACTOR IS A TROPICAL SYSTEM CURRENTLY WELL
OUT IN THE ATLANTIC THAT THE TROPICAL MODELS TRACK INTO THE
BAHAMAS BY LATE WEEK...MAKING A TANTALIZING FEATURE FOR THE
EASTERN US TROF TO PERHAPS INTERACT WITH.
WHAT HAS BEEN INTERESTING SO FAR THIS JULY HAS BEEN THE RATHER
HIGH LATITUDE THE BERMUDA RIDGE HAS OCCUPIED FOR SO EARLY IN THE
SEASON. THE LATEST PROGS ONCE AGAIN HAVE A STRONG CLOSED UPPER
HIGH AT UNUSUALLY HIGH LATITUDES BY NEXT WEEKEND. IF THE TROPICAL
SYSTEM CAN MANAGE TO HOLD TOGETHER...IT WOULD SUGGEST THE EASTERN
SEABOARD WOULD BE VULNERABLE IN ABOUT A WEEK`S TIME. STAY TUNED.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
LINE OF THUNDERSTORMS...ACCOMPANIED BY BRIEF GUSTY WINDS AND IFR
VSBYS...IS PUSHING THRU THE SUSQ VALLEY AS OF 21Z. FOR MUCH OF
CENTRAL PA...EXPECT A RETURN TO VFR CONDS WITHIN A COUPLE HOURS
AFTER PASSAGE OF THUNDERSTORMS. HOWEVER...RESIDUAL LOW LVL
MOISTURE ASCENDING THE W MTNS COULD PRODUCE SOME LOW CIGS ACROSS
THE LAUREL HIGHLANDS THIS EVENING /JST REPORTING SCT009 AT 21Z AND
K2G4 REPORTING A 800FT CIG/. THE LOW CIG THREAT COULD SPREAD NORTH
ALONG THE ALLEGHENY MTNS TOWARD BFD LATE TONIGHT AS BLYR COOLS. LATEST
SREF AND RAP OUTPUT BOTH SUPPORT THIS THREAT OF IFR CONDS ACROSS
THE W MTNS. FURTHER EAST...FOG IS CERTAINLY A POSSIBILITY...GIVEN
THE WET GROUND AND PARTIAL CLEARING EXPECTED OVERNIGHT.
HOWEVER...PRES GRADIENT SUGGESTS THERE WILL BE ENOUGH OF A WIND TO
PRECLUDE IFR VSBYS.
AN UPPER LVL LOW WILL PUSH EAST TOWARD PA MONDAY. THIS WILL BRING
ANOTHER HIGH PROB OF SHRA AND TSRA.
OUTLOOK...
MON...AM LOW CIGS POSS W MTNS. ISOLD THUNDERSTORM IMPACTS.
TUE-THU...AM LOW CIGS POSS W MTNS. SCT THUNDERSTORM IMPACTS
POSS...MAINLY DURING THE PM HOURS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1044 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 916 PM CDT MON JUL 8 2013
DESPITE A WAVE SEEN ON WATER VAPOR IMAGERY MOVING INTO A HIGHLY
UNSTABLE AIRMASS FROM INTERSTATE 90 TO NEAR THE MISSOURI RIVER
FEATURING 2000 TO 3000 J/KG OF CAPE...HAVE FAILED TO SEE MUCH IN THE
WAY OF STORM DEVELOPMENT TO THIS POINT. TOUGH TO PINPOINT EXACT
REASONS...BUT APPARENTLY MID LEVEL PROFILES WERE EITHER A BIT WARMER
OR DRYER THAN MODELED...OR POTENTIALLY A COMBINATION OF THEM BOTH. AM
SEEING SOME NEW DEVELOPMENT IN CENTRAL SOUTH DAKOTA. THESE STORMS
ARE NEARLY STATIONARY. THIS MAKES SENSE GIVEN THAT MEAN CLOUD LAYER
WINDS ARE LESS THAN 5 KTS. SO QUESTION REMAINS...WHAT ARE OUR STORM
CHANCES. IF STORMS ARE ABLE TO ORGANIZE ALONG AN OUTFLOW...AN EAST
SOUTHEAST MOTION WOULD BE EXPECTED...AS CAN BE SEEN WITH THE STORM
CURRENTLY IN NORTH CENTRAL NEBRASKA. WILL CONTINUE TO MONITOR STORMS
IN CENTRAL SOUTH DAKOTA. NOT OUT OF THE QUESTION THAT AS OUTFLOW
FROM THE WESTERN PORTION OF THE STATE INTERACTS WITH THESE
STORMS...AND THE LOW LEVEL JET PICKS UP...THAT THEY ORGANIZE AND
MOVE SOUTHEAST INTO AREAS WEST OF THE JAMES RIVER VALLEY. FOR THAT
REASON AFTER COORDINATION WITH SURROUNDING OFFICES AND
SPC...EXTENDED THE SEVERE THUNDERSTORM WATCH UNTIL 04Z. BY THAT TIME
CONVECTIVE EVOLUTION SHOULD HOPEFULLY BECOME MORE CLEAR. ONE THING
GOING AGAINST STORM ORGANIZATION IS THE LARGE AREA OF DRYING SEEN
ON WATER VAPOR...SUGGESTIVE OF LARGE SCALE SUBSIDENCE OVERTAKING THE
AREA. EAST OF THE JAMES RIVER THE THREAT APPEARS TO BE
DECREASING...ALTHOUGH AS THE LOW LEVEL JET PICKS UP CAN NOT
COMPLETELY RULE OUT A FEW STORMS FORMING ANYWHERE SOUTH OF
INTERSTATE 90. BUT OVERALL THE SEVERE THREAT FOR THE EVENING APPEARS
TO BE DECREASING.
QUESTION THEN BECOMES WHAT HAPPENS TO THE SEVERE LINE OF STORMS
CURRENTLY ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA. THIS AREA
OF STORMS IS CURRENTLY PUSHING EAST SOUTHEAST...AND THE HRRR NOW
SUGGESTS THAT THIS LINE COULD POSSIBLY SURVIVE INTO OUR CWA. IF
STORMS THIS EVENING DO NOT MATERIALIZE THE ATMOSPHERE COULD INDEED
MAINTAIN ENOUGH INSTABILITY TO SUPPORT THIS LINE. SO SOMETHING TO
WATCH. IF IT DOES SURVIVE..EXPECT IT TO APPROACH THE MISSOURI RIVER
BY 4 AM. WIND GUSTS TO 60 MPH WOULD SEEM POSSIBLE IN THE LINE SHALL
IT HOLD TOGETHER. HAVE A TOUGH TIME BELIEVING IT WOULD MAINTAIN
SEVERE INTENSITY MUCH EAST OF THE JAMES RIVER IF EVEN THAT FAR...BUT
TIMING WOULD PUT IT ALONG INTERSTATE 29 NEAR 6 AM.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
ATTENTION IN THE SHORT TERM IS ON THE CONVECTIVE DEVELOPMENT.
OUTFLOW/FRONTAL HYBRID REMAINS DISTINCT ACROSS WESTERN IOWA JUST
ALONG THE SOUTHERN EDGE OF THE CWA...BUT MORE DIFFUSE HEADING WEST
INTO NEBRASKA. MCV PASSING SOUTH OF CWA...AND RECENTLY HAVE SEEN
LONE CONVECTIVE CELL DEVELOP ALONG THIS BOUNDARY NEAR CWA BORDER...
AND NOT SURPRISED WITH RAP ANALYSIS INDICATING WEAKENED /MORE LIKELY
WEAKENING/ CAP. LIKELY THAT MOST AREAS AT LEAST A WEAK CAP REMAINS
/ON ORDER OF A SKINNY 20-40 J/KG/ IF SOME PRECONVECTED MODELS USED
FOR GUIDANCE. NO QUESTION ATMOSPHERE IS CERTAINLY LOADING UP ON
POTENTIAL ENERGY THIS AFTERNOON...BUT SOMEWHAT LESS OUT IN THE FAR
WEST WHERE HAVE BEEN ALONG EDGE OF NAGGING CIRRUS SHIELD FROM
EARLIER DAY ACTIVITY. THE AREA ACROSS NORTHWEST IOWA WILL BE ONE
AREA OF CONVECTIVE THREAT FOR THE LATE AFTERNOON AND EARLY EVENING...
AND THREATS THERE WILL BALANCE BETWEEN QUARTER TO HALF DOLLAR HAIL...
AND DAMAGING WIND GUSTS. ALSO MUST NOT FORGET THAT FAIRLY WEAK WINDS
ALONG WITH RIGHT MOVING SUPERCELL MOTION OF 5 TO 10 KNOTS MAXIMUM
THROUGH EARLY EVENING...WITH WARM CLOUD DEPTHS OVER 12 KFT...FLASH
FLOODING IS A RISK.
EFFECTIVELY SHEAR IS IN THAT 30-40 KNOT RANGE...AND CERTAINLY IN THE
REALM WHERE SUERCELLS WOULD CERTAINLY BE POSSIBLE...OR AT LEAST
HYBRID WITH LINEAR/BOWING STRUCTURE. LOWER TO MID LEVEL STORM
RELATIVE INFLOW FAIRLY BALANCED...SO MAY END UP WITH A FAIRLY STABLE
BOWING STRUCTURE...AND SOMETHING TOWARD A HIGHER END DAMAGING WIND
EVENT IS NOT OUT OF THE QUESTION. MOST HIGH RESOLUTION GUIDANCE IS
SUPPORTIVE OF THIS MODE...AND LITTLE REASON TO DOUBT IT. FOR NOW...
MOST LIKELY AREA WOULD APPEAR TO BE NEAR/SOUTH OF INTERSTATE 90 FROM
THE EARLY EVENING HOURS NEAR 9V9...AROUND MIDNIGHT CLOSER TO
I29...AND A BIT LATER THROUGH NW IA.
IN THE WAKE OF THE MCS...WILL AGAIN BE POTENTIAL FOR SOME PATCHY FOG
WHERE SKIES CAN CLEAR...AND ADDED SMALL MENTION FOR AREAS GENERALLY
NEAR/SOUTH OF I90 AND NEAR/WEST OF I29.
AFTER THE ATMOSPHERE BEING WORKED OVER TONIGHT...VEERING LOW LEVEL
JET SHOULD QUICKLY END EARLY DAY ACTION EAST...WITH TEMPS CONTINUING
TO WARM ALOFT AHEAD OF FAIRLY STRONG UPPER ENERGY...WHICH WILL SWING
SOUTHEAST ACROSS THE AREA ON TUESDAY AFTERNOON. AT THE SURFACE...
OUTFLOW/CONVERGENCE BOUNDARY SHOULD BE LEADING THE AREA ACROSS
NORTHWEST IOWA BY MIDDAY... HOWEVER...THE STRONGER BOUNDARY/MOISTURE
DISCONTINUITY WILL BE TIED TO THE UPPER ENERGY. AREAS BETWEEN THE
BOUNDARIES WILL CONTINUE STIFLING HUMIDITY AND HAVE MUCH OF NW IA
REACHING HEAT INDEX VALUES FROM 100 TO 105 FROM MIDDAY TOMORROW
THROUGH MUCH OF THE AFTERNOON. LIKELY TO REMAIN FAIRLY CAPPED UNTIL
LIFT FROM APPROACHING FRONT AND COOLING TEMPS ALOFT WITH UPPER WAVE.
EFFECTIVE SHEAR LOOKS TO BE A BIT STRONGER AND QUITE LINEAR...AND A
SEVERE RISK OVER THE SOUTHEASTERN 2/3 OF THE AREA LOOKS WARRANTED
GIVEN THE DEGREE OF POTENTIAL INSTABILITY AND EFFECTIVE SHEAR.
THREAT WOULD AGAIN BE PRIMARILY HAIL AND DAMAGING WIND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
THE SHORTWAVE AND FRONTAL BOUNDARY WILL TRACK OFF TO THE EAST BY
TUESDAY EVENING...WITH ANY LINGERING THUNDERSTORM ACTIVITY FOLLOWING
SUIT. WITH DECENT COLD AIR ADVECTION AND DRYING BEHIND THE EXITING
SYSTEM...IT WILL BE A COOLER NIGHT WITH LOWERING DEW POINTS. LOWS
WILL BOTTOM OUT IN THE UPPER 50S TO LOWER 60S BY EARLY WEDNESDAY
MORNING.
A SURFACE RIDGE SLIDES SOUTHWARD THROUGH THE REGION ON
WEDNESDAY...PROVIDING FOR A PLEASANT DAY WITH LIGHT WINDS AND DEW
POINTS DOWN INTO THE 50S. HIGHS WILL BE SEASONABLE FOR THIS TIME OF
YEAR WITH READINGS IN THE UPPER 70S TO LOWER 80S.
THURSDAY ALSO LOOKS TO BE A DECENT DAY...ALBEIT WARMER AS HIGH
PRESSURE BEGINS TO MOVE OFF TO THE EAST AND A SOUTHERLY FLOW
RETURNS TO THE REGION. WITH 850 MB TEMPERATURES CLIMBING AROUND 3
DEGREES OVER WEDNESDAY...HIGHS WILL RISE INTO THE LOWER 80S EAST TO
NEAR 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA.
IN THE EXTENDED...UPPER LEVEL RIDGE BUILDS INTO THE REGION THROUGH
THE END OF THE WEEK...TRANSITIONING TO A MORE WEST-EAST FLOW BY THE
START OF NEXT WEEK. THIS WILL BRING A CONTINUED WARM UP INTO
SUNDAY...THEN SOME COOLING POSSIBLE BY MONDAY. AS LOW LEVEL MOISTURE
AND INSTABILITY INCREASE THROUGH THE PERIOD...CONVECTION CHANCES
WILL INCREASE FOR THE WEEKEND...WITH TYPICAL MODEL DIFFERENCES IN
TIMING/PLACEMENT OF CONVECTION. HIGHS INTO THE WEEKEND LOOK TO
GENERALLY BE IN THE MID 80S TO LOWER 90S...WITH LOWS UPPER 60S TO
LOWER 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1037 PM CDT MON JUL 8 2013
CONVECTION TRYING TO MOVE INTO OUR CFWA BUT NOT HAVING MUCH LUCK
DESPITE ALL THE MESOSCALE INDICES SHOWING HOW UNSTABLE WE ACTUALLY
ARE. INCREASING LOW LEVEL JET MAY BTTER THE CHANCES FOR STORMS
ACROSS SOUTHERN PORTIONS OF THE AREA. OTHERWISE...OTHER AREAS WILL
HAVE TO WAIT TO SEE IF NORTHWESTERN SD CONVECTIVE COMPLEX
CONTINUES TO DEVELOP SOUTHWARD AS IT MOVES EAST. HR3 DATA
INDICATES A PRETTY CHANCE OF THAT OCCURRING. HOWEVER...DUE TO THE
UNCERTAINITY OF POPS AND TIMING...I KEPT OUT MENTION OF STORMS IN
TAFS AFTER 09Z. SHOULD SEE ANOTHER ROUND OF STORMS ON TUESDAY
AFTER 19Z OR SO.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...HEITKAMP
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
916 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 916 PM CDT MON JUL 8 2013
DESPITE A WAVE SEEN ON WATER VAPOR IMAGERY MOVING INTO A HIGHLY
UNSTABLE AIRMASS FROM INTERSTATE 90 TO NEAR THE MISSOURI RIVER
FEATURING 2000 TO 3000 J/KG OF CAPE...HAVE FAILED TO SEE MUCH IN THE
WAY OF STORM DEVELOPMENT TO THIS POINT. TOUGH TO PINPOINT EXACT
REASONS...BUT APPARENTLY MID LEVEL PROFILES WERE EITHER A BIT WARMER
OR DRYER THAN MODELED...OR POTENTIALLY A COMBINATION OF THEM BOTH. AM
SEEING SOME NEW DEVELOPMENT IN CENTRAL SOUTH DAKOTA. THESE STORMS
ARE NEARLY STATIONARY. THIS MAKES SENSE GIVEN THAT MEAN CLOUD LAYER
WINDS ARE LESS THAN 5 KTS. SO QUESTION REMAINS...WHAT ARE OUR STORM
CHANCES. IF STORMS ARE ABLE TO ORGANIZE ALONG AN OUTFLOW...AN EAST
SOUTHEAST MOTION WOULD BE EXPECTED...AS CAN BE SEEN WITH THE STORM
CURRENTLY IN NORTH CENTRAL NEBRASKA. WILL CONTINUE TO MONITOR STORMS
IN CENTRAL SOUTH DAKOTA. NOT OUT OF THE QUESTION THAT AS OUTFLOW
FROM THE WESTERN PORTION OF THE STATE INTERACTS WITH THESE
STORMS...AND THE LOW LEVEL JET PICKS UP...THAT THEY ORGANIZE AND
MOVE SOUTHEAST INTO AREAS WEST OF THE JAMES RIVER VALLEY. FOR THAT
REASON AFTER COORDINATION WITH SURROUNDING OFFICES AND
SPC...EXTENDED THE SEVERE THUNDERSTORM WATCH UNTIL 04Z. BY THAT TIME
CONVECTIVE EVOLUTION SHOULD HOPEFULLY BECOME MORE CLEAR. ONE THING
GOING AGAINST STORM ORGANIZATION IS THE LARGE AREA OF DRYING SEEN
ON WATER VAPOR...SUGGESTIVE OF LARGE SCALE SUBSIDENCE OVERTAKING THE
AREA. EAST OF THE JAMES RIVER THE THREAT APPEARS TO BE
DECREASING...ALTHOUGH AS THE LOW LEVEL JET PICKS UP CAN NOT
COMPLETELY RULE OUT A FEW STORMS FORMING ANYWHERE SOUTH OF
INTERSTATE 90. BUT OVERALL THE SEVERE THREAT FOR THE EVENING APPEARS
TO BE DECREASING.
QUESTION THEN BECOMES WHAT HAPPENS TO THE SEVERE LINE OF STORMS
CURRENTLY ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA. THIS AREA
OF STORMS IS CURRENTLY PUSHING EAST SOUTHEAST...AND THE HRRR NOW
SUGGESTS THAT THIS LINE COULD POSSIBLY SURVIVE INTO OUR CWA. IF
STORMS THIS EVENING DO NOT MATERIALIZE THE ATMOSPHERE COULD INDEED
MAINTAIN ENOUGH INSTABILITY TO SUPPORT THIS LINE. SO SOMETHING TO
WATCH. IF IT DOES SURVIVE..EXPECT IT TO APPROACH THE MISSOURI RIVER
BY 4 AM. WIND GUSTS TO 60 MPH WOULD SEEM POSSIBLE IN THE LINE SHALL
IT HOLD TOGETHER. HAVE A TOUGH TIME BELIEVING IT WOULD MAINTAIN
SEVERE INTENSITY MUCH EAST OF THE JAMES RIVER IF EVEN THAT FAR...BUT
TIMING WOULD PUT IT ALONG INTERSTATE 29 NEAR 6 AM.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
ATTENTION IN THE SHORT TERM IS ON THE CONVECTIVE DEVELOPMENT.
OUTFLOW/FRONTAL HYBRID REMAINS DISTINCT ACROSS WESTERN IOWA JUST
ALONG THE SOUTHERN EDGE OF THE CWA...BUT MORE DIFFUSE HEADING WEST
INTO NEBRASKA. MCV PASSING SOUTH OF CWA...AND RECENTLY HAVE SEEN
LONE CONVECTIVE CELL DEVELOP ALONG THIS BOUNDARY NEAR CWA BORDER...
AND NOT SURPRISED WITH RAP ANALYSIS INDICATING WEAKENED /MORE LIKELY
WEAKENING/ CAP. LIKELY THAT MOST AREAS AT LEAST A WEAK CAP REMAINS
/ON ORDER OF A SKINNY 20-40 J/KG/ IF SOME PRECONVECTED MODELS USED
FOR GUIDANCE. NO QUESTION ATMOSPHERE IS CERTAINLY LOADING UP ON
POTENTIAL ENERGY THIS AFTERNOON...BUT SOMEWHAT LESS OUT IN THE FAR
WEST WHERE HAVE BEEN ALONG EDGE OF NAGGING CIRRUS SHIELD FROM
EARLIER DAY ACTIVITY. THE AREA ACROSS NORTHWEST IOWA WILL BE ONE
AREA OF CONVECTIVE THREAT FOR THE LATE AFTERNOON AND EARLY EVENING...
AND THREATS THERE WILL BALANCE BETWEEN QUARTER TO HALF DOLLAR HAIL...
AND DAMAGING WIND GUSTS. ALSO MUST NOT FORGET THAT FAIRLY WEAK WINDS
ALONG WITH RIGHT MOVING SUPERCELL MOTION OF 5 TO 10 KNOTS MAXIMUM
THROUGH EARLY EVENING...WITH WARM CLOUD DEPTHS OVER 12 KFT...FLASH
FLOODING IS A RISK.
EFFECTIVELY SHEAR IS IN THAT 30-40 KNOT RANGE...AND CERTAINLY IN THE
REALM WHERE SUERCELLS WOULD CERTAINLY BE POSSIBLE...OR AT LEAST
HYBRID WITH LINEAR/BOWING STRUCTURE. LOWER TO MID LEVEL STORM
RELATIVE INFLOW FAIRLY BALANCED...SO MAY END UP WITH A FAIRLY STABLE
BOWING STRUCTURE...AND SOMETHING TOWARD A HIGHER END DAMAGING WIND
EVENT IS NOT OUT OF THE QUESTION. MOST HIGH RESOLUTION GUIDANCE IS
SUPPORTIVE OF THIS MODE...AND LITTLE REASON TO DOUBT IT. FOR NOW...
MOST LIKELY AREA WOULD APPEAR TO BE NEAR/SOUTH OF INTERSTATE 90 FROM
THE EARLY EVENING HOURS NEAR 9V9...AROUND MIDNIGHT CLOSER TO
I29...AND A BIT LATER THROUGH NW IA.
IN THE WAKE OF THE MCS...WILL AGAIN BE POTENTIAL FOR SOME PATCHY FOG
WHERE SKIES CAN CLEAR...AND ADDED SMALL MENTION FOR AREAS GENERALLY
NEAR/SOUTH OF I90 AND NEAR/WEST OF I29.
AFTER THE ATMOSPHERE BEING WORKED OVER TONIGHT...VEERING LOW LEVEL
JET SHOULD QUICKLY END EARLY DAY ACTION EAST...WITH TEMPS CONTINUING
TO WARM ALOFT AHEAD OF FAIRLY STRONG UPPER ENERGY...WHICH WILL SWING
SOUTHEAST ACROSS THE AREA ON TUESDAY AFTERNOON. AT THE SURFACE...
OUTFLOW/CONVERGENCE BOUNDARY SHOULD BE LEADING THE AREA ACROSS
NORTHWEST IOWA BY MIDDAY... HOWEVER...THE STRONGER BOUNDARY/MOISTURE
DISCONTINUITY WILL BE TIED TO THE UPPER ENERGY. AREAS BETWEEN THE
BOUNDARIES WILL CONTINUE STIFLING HUMIDITY AND HAVE MUCH OF NW IA
REACHING HEAT INDEX VALUES FROM 100 TO 105 FROM MIDDAY TOMORROW
THROUGH MUCH OF THE AFTERNOON. LIKELY TO REMAIN FAIRLY CAPPED UNTIL
LIFT FROM APPROACHING FRONT AND COOLING TEMPS ALOFT WITH UPPER WAVE.
EFFECTIVE SHEAR LOOKS TO BE A BIT STRONGER AND QUITE LINEAR...AND A
SEVERE RISK OVER THE SOUTHEASTERN 2/3 OF THE AREA LOOKS WARRANTED
GIVEN THE DEGREE OF POTENTIAL INSTABILITY AND EFFECTIVE SHEAR.
THREAT WOULD AGAIN BE PRIMARILY HAIL AND DAMAGING WIND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
THE SHORTWAVE AND FRONTAL BOUNDARY WILL TRACK OFF TO THE EAST BY
TUESDAY EVENING...WITH ANY LINGERING THUNDERSTORM ACTIVITY FOLLOWING
SUIT. WITH DECENT COLD AIR ADVECTION AND DRYING BEHIND THE EXITING
SYSTEM...IT WILL BE A COOLER NIGHT WITH LOWERING DEW POINTS. LOWS
WILL BOTTOM OUT IN THE UPPER 50S TO LOWER 60S BY EARLY WEDNESDAY
MORNING.
A SURFACE RIDGE SLIDES SOUTHWARD THROUGH THE REGION ON
WEDNESDAY...PROVIDING FOR A PLEASANT DAY WITH LIGHT WINDS AND DEW
POINTS DOWN INTO THE 50S. HIGHS WILL BE SEASONABLE FOR THIS TIME OF
YEAR WITH READINGS IN THE UPPER 70S TO LOWER 80S.
THURSDAY ALSO LOOKS TO BE A DECENT DAY...ALBEIT WARMER AS HIGH
PRESSURE BEGINS TO MOVE OFF TO THE EAST AND A SOUTHERLY FLOW
RETURNS TO THE REGION. WITH 850 MB TEMPERATURES CLIMBING AROUND 3
DEGREES OVER WEDNESDAY...HIGHS WILL RISE INTO THE LOWER 80S EAST TO
NEAR 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA.
IN THE EXTENDED...UPPER LEVEL RIDGE BUILDS INTO THE REGION THROUGH
THE END OF THE WEEK...TRANSITIONING TO A MORE WEST-EAST FLOW BY THE
START OF NEXT WEEK. THIS WILL BRING A CONTINUED WARM UP INTO
SUNDAY...THEN SOME COOLING POSSIBLE BY MONDAY. AS LOW LEVEL MOISTURE
AND INSTABILITY INCREASE THROUGH THE PERIOD...CONVECTION CHANCES
WILL INCREASE FOR THE WEEKEND...WITH TYPICAL MODEL DIFFERENCES IN
TIMING/PLACEMENT OF CONVECTION. HIGHS INTO THE WEEKEND LOOK TO
GENERALLY BE IN THE MID 80S TO LOWER 90S...WITH LOWS UPPER 60S TO
LOWER 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 625 PM CDT MON JUL 8 2013
MAIN FORECAST CONCERN IS THUNDERSTORM DEVELOPMENT IN THE SHORT
TERM. AT THIS POINT...THE MOST FAVORED AREAS ARE SOUTH OF
INTERSTATE 90 SO THAT INCLUDES KFSD AND KSUX. EARLIER THOUGHTS OF
MCS DEVELOPMENT MAY BE DECREASING BUT WILL HAVE TO KEEP AN EYE ON
SOUTHCENTRAL SD AND NORTHCENTRAL NE AS MAIN WAVE INTERACTS WITH
EXISTING CONVECTION. IF MORE ORGANIZED STORMS DO NOT DEVELOP THEN
MCS POSSIBILITIES ARE LOW. WITH THAT IN MIND TOOK OUT MENTION OF
FOG IN KFSD AS CHANCES ARE REMOTE AT BEST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...HEITKAMP
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
634 PM CDT MON JUL 8 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
ATTENTION IN THE SHORT TERM IS ON THE CONVECTIVE DEVELOPMENT.
OUTFLOW/FRONTAL HYBRID REMAINS DISTINCT ACROSS WESTERN IOWA JUST
ALONG THE SOUTHERN EDGE OF THE CWA...BUT MORE DIFFUSE HEADING WEST
INTO NEBRASKA. MCV PASSING SOUTH OF CWA...AND RECENTLY HAVE SEEN
LONE CONVECTIVE CELL DEVELOP ALONG THIS BOUNDARY NEAR CWA BORDER...
AND NOT SURPRISED WITH RAP ANALYSIS INDICATING WEAKENED /MORE LIKELY
WEAKENING/ CAP. LIKELY THAT MOST AREAS AT LEAST A WEAK CAP REMAINS
/ON ORDER OF A SKINNY 20-40 J/KG/ IF SOME PRECONVECTED MODELS USED
FOR GUIDANCE. NO QUESTION ATMOSPHERE IS CERTAINLY LOADING UP ON
POTENTIAL ENERGY THIS AFTERNOON...BUT SOMEWHAT LESS OUT IN THE FAR
WEST WHERE HAVE BEEN ALONG EDGE OF NAGGING CIRRUS SHIELD FROM
EARLIER DAY ACTIVITY. THE AREA ACROSS NORTHWEST IOWA WILL BE ONE
AREA OF CONVECTIVE THREAT FOR THE LATE AFTERNOON AND EARLY EVENING...
AND THREATS THERE WILL BALANCE BETWEEN QUARTER TO HALF DOLLAR HAIL...
AND DAMAGING WIND GUSTS. ALSO MUST NOT FORGET THAT FAIRLY WEAK WINDS
ALONG WITH RIGHT MOVING SUPERCELL MOTION OF 5 TO 10 KNOTS MAXIMUM
THROUGH EARLY EVENING...WITH WARM CLOUD DEPTHS OVER 12 KFT...FLASH
FLOODING IS A RISK.
EFFECTIVELY SHEAR IS IN THAT 30-40 KNOT RANGE...AND CERTAINLY IN THE
REALM WHERE SUERCELLS WOULD CERTAINLY BE POSSIBLE...OR AT LEAST
HYBRID WITH LINEAR/BOWING STRUCTURE. LOWER TO MID LEVEL STORM
RELATIVE INFLOW FAIRLY BALANCED...SO MAY END UP WITH A FAIRLY STABLE
BOWING STRUCTURE...AND SOMETHING TOWARD A HIGHER END DAMAGING WIND
EVENT IS NOT OUT OF THE QUESTION. MOST HIGH RESOLUTION GUIDANCE IS
SUPPORTIVE OF THIS MODE...AND LITTLE REASON TO DOUBT IT. FOR NOW...
MOST LIKELY AREA WOULD APPEAR TO BE NEAR/SOUTH OF INTERSTATE 90 FROM
THE EARLY EVENING HOURS NEAR 9V9...AROUND MIDNIGHT CLOSER TO
I29...AND A BIT LATER THROUGH NW IA.
IN THE WAKE OF THE MCS...WILL AGAIN BE POTENTIAL FOR SOME PATCHY FOG
WHERE SKIES CAN CLEAR...AND ADDED SMALL MENTION FOR AREAS GENERALLY
NEAR/SOUTH OF I90 AND NEAR/WEST OF I29.
AFTER THE ATMOSPHERE BEING WORKED OVER TONIGHT...VEERING LOW LEVEL
JET SHOULD QUICKLY END EARLY DAY ACTION EAST...WITH TEMPS CONTINUING
TO WARM ALOFT AHEAD OF FAIRLY STRONG UPPER ENERGY...WHICH WILL SWING
SOUTHEAST ACROSS THE AREA ON TUESDAY AFTERNOON. AT THE SURFACE...
OUTFLOW/CONVERGENCE BOUNDARY SHOULD BE LEADING THE AREA ACROSS
NORTHWEST IOWA BY MIDDAY... HOWEVER...THE STRONGER BOUNDARY/MOISTURE
DISCONTINUITY WILL BE TIED TO THE UPPER ENERGY. AREAS BETWEEN THE
BOUNDARIES WILL CONTINUE STIFLING HUMIDITY AND HAVE MUCH OF NW IA
REACHING HEAT INDEX VALUES FROM 100 TO 105 FROM MIDDAY TOMORROW
THROUGH MUCH OF THE AFTERNOON. LIKELY TO REMAIN FAIRLY CAPPED UNTIL
LIFT FROM APPROACHING FRONT AND COOLING TEMPS ALOFT WITH UPPER WAVE.
EFFECTIVE SHEAR LOOKS TO BE A BIT STRONGER AND QUITE LINEAR...AND A
SEVERE RISK OVER THE SOUTHEASTERN 2/3 OF THE AREA LOOKS WARRANTED
GIVEN THE DEGREE OF POTENTIAL INSTABILITY AND EFFECTIVE SHEAR.
THREAT WOULD AGAIN BE PRIMARILY HAIL AND DAMAGING WIND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM CDT MON JUL 8 2013
THE SHORTWAVE AND FRONTAL BOUNDARY WILL TRACK OFF TO THE EAST BY
TUESDAY EVENING...WITH ANY LINGERING THUNDERSTORM ACTIVITY FOLLOWING
SUIT. WITH DECENT COLD AIR ADVECTION AND DRYING BEHIND THE EXITING
SYSTEM...IT WILL BE A COOLER NIGHT WITH LOWERING DEW POINTS. LOWS
WILL BOTTOM OUT IN THE UPPER 50S TO LOWER 60S BY EARLY WEDNESDAY
MORNING.
A SURFACE RIDGE SLIDES SOUTHWARD THROUGH THE REGION ON
WEDNESDAY...PROVIDING FOR A PLEASANT DAY WITH LIGHT WINDS AND DEW
POINTS DOWN INTO THE 50S. HIGHS WILL BE SEASONABLE FOR THIS TIME OF
YEAR WITH READINGS IN THE UPPER 70S TO LOWER 80S.
THURSDAY ALSO LOOKS TO BE A DECENT DAY...ALBEIT WARMER AS HIGH
PRESSURE BEGINS TO MOVE OFF TO THE EAST AND A SOUTHERLY FLOW
RETURNS TO THE REGION. WITH 850 MB TEMPERATURES CLIMBING AROUND 3
DEGREES OVER WEDNESDAY...HIGHS WILL RISE INTO THE LOWER 80S EAST TO
NEAR 90 THROUGH SOUTH CENTRAL SOUTH DAKOTA.
IN THE EXTENDED...UPPER LEVEL RIDGE BUILDS INTO THE REGION THROUGH
THE END OF THE WEEK...TRANSITIONING TO A MORE WEST-EAST FLOW BY THE
START OF NEXT WEEK. THIS WILL BRING A CONTINUED WARM UP INTO
SUNDAY...THEN SOME COOLING POSSIBLE BY MONDAY. AS LOW LEVEL MOISTURE
AND INSTABILITY INCREASE THROUGH THE PERIOD...CONVECTION CHANCES
WILL INCREASE FOR THE WEEKEND...WITH TYPICAL MODEL DIFFERENCES IN
TIMING/PLACEMENT OF CONVECTION. HIGHS INTO THE WEEKEND LOOK TO
GENERALLY BE IN THE MID 80S TO LOWER 90S...WITH LOWS UPPER 60S TO
LOWER 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 625 PM CDT MON JUL 8 2013
MAIN FORECAST CONCERN IS THUNDERSTORM DEVELOPMENT IN THE SHORT
TERM. AT THIS POINT...THE MOST FAVORED AREAS ARE SOUTH OF
INTERSTATE 90 SO THAT INCLUDES KFSD AND KSUX. EARLIER THOUGHTS OF
MCS DEVELOPMENT MAY BE DECREASING BUT WILL HAVE TO KEEP AN EYE ON
SOUTHCENTRAL SD AND NORTHCENTRAL NE AS MAIN WAVE INTERACTS WITH
EXISTING CONVECTION. IF MORE ORGANIZED STORMS DO NOT DEVELOP THEN
MCS POSSIBILITIES ARE LOW. WITH THAT IN MIND TOOK OUT MENTION OF
FOG IN KFSD AS CHANCES ARE REMOTE AT BEST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...JM
AVIATION...HEITKAMP
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1237 PM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 1054 AM CDT SUN JUL 7 2013
INTERESTING FORECAST FOR TODAY. WEAK UPPER WAVE GENERATING AN AREA
OF ELEVATED SHOWERS AND STORMS ACROSS CENTRAL SOUTH DAKOTA THIS
MORNING. AS THIS WAVE MOVES EAST OUR CWA WILL SEE WEAK UPPER FORCING
FOR ASCENT. EXPECT CIRRUS FROM THIS ACTIVITY TO WORK ITS WAY INTO
OUR WESTERN CWA AS WE HEAD INTO THIS AFTERNOON. MEANWHILE FRONTAL
BOUNDARY IS TAKING ITS SLOW TIME MOVING SOUTH ACROSS OUR CWA. SO
QUESTION BECOMES WHAT ARE OUR CONVECTION CHANCES THIS AFTERNOON. A
COUPLE THINGS TO WATCH WILL BE DEWPOINT EVOLUTION AND CONVECTIVE
EVOLUTION ACROSS CENTRAL AND WESTERN SOUTH DAKOTA.
MOISTURE POOLING BEHIND THE FRONT IS CURRENTLY ALLOWING DEWPOINTS TO
CREEP INTO THE LOW 70S IN SPOTS. A LOT OF GUIDANCE SUGGEST THESE
DEWPOINTS MAY STRUGGLE TO MIX OUT...WITH RELATIVELY DEEP MOISTURE
PRESENT UP TO ABOUT 850 MB...AND WEAK FLOW. AS TEMPERATURES RISE
INTO THE 80S THIS AFTERNOON...MLCAPE COULD END UP IN THE 2000 TO
3000 J/KG RANGE IN THE AREA OF MOISTURE POOLING. CIN WOULD ALSO
BECOME ALMOST ZERO. HOWEVER A VERY DRY LAYER AROUND 700 MB WILL
LIKELY HINDER UPDRAFTS SOMEWHAT...AND DESPITE THE BOUNDARY
NEARBY...SEE VERY LITTLE IN THE WAY OF LOW LEVEL CONVERGENCE OR
FORCING FOR ASCENT. SO IT WOULD COME DOWN TO WHETHER THE INSTABILITY
AND WEAK UPPER FORCING WOULD BE ENOUGH TO GET DEEP CU THROUGH THE
DRY AIR. HI RES GUIDANCE...SUCH AS THE 06Z WRF ARW AND 12Z 4KM NAM
BOTH SUGGEST THIS MAY HAPPEN. THUS WENT AHEAD AND ADDED IN A SLIGHT
CHANCE OF STORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF OUR
CWA. AGAIN THIS IS REALLY DEPENDENT ON IF WE CAN KEEP DEWPOINTS IN
THE LOWER 70S. IF THEY FAIL TO MATERIALIZE...THEN DRY AIR ALOFT AND
WARM LAYER BETWEEN 800 AND 600 MB WILL LIKELY BE ENOUGH TO CAP
CONVECTION. WIND SHEAR IS WEAK...THUS ANY STORM WOULD BE PULSE OR
POSSIBLY MULTICELL TYPE. BUT GIVEN WHAT WOULD BE HIGH
INSTABILITY...WOULD EXPECT AT LEAST THE THREAT OF QUARTER SIZE HAIL
AND 60 MPH WIND GUSTS IN ANY STORM. HRRR DEVELOPS CONVECTION IN
CENTRAL SOUTH DAKOTA THIS AFTERNOON...AND MOVES IT INTO OUR WESTERN
CWA LATER THIS AFTERNOON AND EVENING. GIVEN EXTENSIVE CLOUD COVER IN
THIS AREA...FEEL SURFACE BASED INITIATION IN CENTRAL SOUTH DAKOTA IS
UNLIKELY THIS AFTERNOON...THUS BELIEVE THE HRRR SOLUTION IS PROBABLY
NOT ACCURATE...AND SO WILL HOLD OFF ON ADDING IN ANY POPS IN OUR
WEST THROUGH 0Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SUN JUL 7 2013
TODAY AND MUCH OF TONIGHT SHOULD REMAIN QUIET IN OUR AREA DESPITE
MESSY...WAVE-RIDDLED MID LEVEL FLOW PATTERN BETWEEN DOMINANT RIDGE
BUILDING WESTWARD ACROSS THE SOUTHERN CONUS AND VARIOUS TROUGHS
TRACKING EASTWARD THROUGH THE CANADIAN PRAIRIES. IN THE NEAR TERM...
SEEING SOME ACCAS AND SPOTTY SHOWERS DEVELOP IN WESTERN IOWA AHEAD OF
WEAK WAVE. SHOWERS ARE NOT EXPECTED TO IMPACT OUR FORECAST AREA THIS
MORNING THOUGH COULD SEE A LITTLE OF THE ACCAS IN OUR FAR EAST EARLY
BEFORE WEAK WAVE PASSES BY. WEAK SURFACE BOUNDARY STILL WEST OF I-29
AS OF 08Z MOVING SOUTHEAST MORE SLOWLY THAN EXPECTED AT THIS TIME
YESTERDAY...THOUGH STILL EXPECTED TO MAKE SOME EASTWARD PROGRESS
THROUGH THE DAY...REACHING NEAR/JUST EAST OF HIGHWAY 60 CORRIDOR
IN NORTHWEST IOWA BY LATE AFTERNOON. WITH WEAK LOW LEVEL
FLOW...EXPECT HIGHER MOISTURE LEVELS TO POOL NEAR THE
BOUNDARY...WITH DEW POINTS IN NORTHWEST IOWA NEAR 70 WHILE
TEMPERATURES CLIMB INTO THE LOWER 90S THIS AFTERNOON. THIS SHOULD
LEAD TO FAIR AMOUNT OF INSTABILITY WHICH COULD POP A STRAY STORM
OR TWO WITH WEAK CONVERGENCE ALONG THE BOUNDARY TOWARD EVENING.
WILL HANG ONTO SLIGHT CHANCE FOR NOW...BUT IF SOME HIGH RES MODELS
SUCH AS RAP/HRRR TURN OUT TO BE ACCURATE IN THEIR DEPICTION OF DEW
POINTS MIXING MUCH LOWER THAN EXPECTED ACROSS OUR SOUTHEAST THIS
AFTERNOON...THEN CAP WOULD BE STRONGER AND WOULD NOT SEE ANY
DEVELOPMENT. WILL BE SOMETHING TO WATCH THROUGH THE DAY.
LATER TONIGHT...WILL BE LOOKING WESTWARD FOR POTENTIAL OF HIGH PLAINS
CONVECTION TO WORK TOWARD OUR WESTERN COUNTIES. STILL FAIR AMOUNT OF
INSTABILITY FOR STORMS TO WORK WITH AS THEY PUSH TOWARD THE MISSOURI
VALLEY AFTER MIDNIGHT. WILL CONTINUE TO CARRY CHANCE INTO AREAS ALONG
AND WEST OF THE JAMES VALLEY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 430 AM CDT SUN JUL 7 2013
IF STORMS DO WORK INTO THE WEST LATE TONIGHT...SHOULD SEE THEM LINGER
INTO THE MORNING HOURS ACROSS OUR WEST AND WILL HANG ONTO CHANCE WEST
OF I-29 FOR NOW. HOWEVER THIS PERIOD COULD JUST AS LIKELY BE DRY...AS
SOME MODELS INDICATING HIGH PLAINS CONVECTION WILL NOT SURVIVE THIS
FAR EAST. ALL-IN-ALL...LOW CONFIDENCE IN PRECIP CHANCES ACROSS OUR
WEST LATE TONIGHT/MONDAY MORNING. CONFIDENCE SOMEWHAT HIGHER THAT WE
WILL SEE DEVELOPMENT ACROSS OUR SOUTH BY MID-LATE AFTERNOON MONDAY...
AS WARM FRONT LIFTS BACK TO NEAR THE MISSOURI RIVER VALLEY AND MID
LEVEL HEIGHTS COLLAPSE IN ADVANCE OF APPROACHING WAVE. WITH LITTLE
FLOW NEAR THE BOUNDARY...SHOULD CONTINUE TO SEE LOW LEVEL MOISTURE
BUILD AND ENHANCE INSTABILITY. ALSO START TO SEE BETTER DEEP LAYER
SHEAR WORK INTO THE REGION...LOCALLY ENHANCED ALONG THE BOUNDARY. FOR
THIS REASON...MONDAY AFTERNOON/EVENING LOOKS TO HAVE FAIR POTENTIAL
FOR SEVERE STORMS AS WAVE /IN SOME MODELS/ SLIDES NORTHEAST ACROSS
THE FRONTAL BOUNDARY.
EVOLUTION OF PRECIP BEYOND THIS SOMEWHAT MUDDLED BY POTENTIAL FOR
LINGERING OUTFLOW BOUNDARIES...BUT GENERALLY EXPECT MOST MONDAY NIGHT
ACTIVITY TO WORK EAST OF THE FORECAST AREA BY EARLY TUESDAY. COLD
FRONT WILL BE PUSHING SOUTHEAST THROUGH THE FORECAST AREA TUESDAY
AFTERNOON...AND EXPECT STRONG WARMING INTO THE LOWER TO MID 90S IN
THERMAL RIDGE AHEAD OF THE FRONT. HUMIDITY LINGERS AS WELL...WITH DEW
POINTS IN THE LOWER OR EVEN MID 70S POSSIBLE ACROSS MUCH OF THE AREA.
THIS WILL GIVE FRONT PLENTY OF INSTABILITY TO FEED ON...WITH STORM
DEVELOPMENT AIDED BY SOUTHERN EXTENT OF MAIN UPPER TROUGH WORKING
THROUGH THE NORTHERN PLAINS. WITH CURRENT FORECAST SPEED OF TROUGH
AND SURFACE BOUNDARY...STORMS SHOULD CLEAR MOST OF THE AREA BY 00Z
THOUGH WILL HOLD ONTO A CHANCE EAST OF HIGHWAY 60 INTO THE EVENING
SHOULD SYSTEM SLOW DOWN A BIT.
EARLIER PROJECTED DRY AND COOLER DAY FOR WEDNESDAY STILL ON SCHEDULE
BEHIND COLD FRONT...AS HIGH PRESSURE MOVES INTO THE NORTHERN PLAINS.
UPPER RIDGING UNANIMOUSLY PROGGED TO RETURN LATER IN THE WEEK WITH A
SLOW INCREASE IN TEMPERATURES AND HUMIDITY AS SURFACE HIGH MOVES
EAST OF OUR AREA. THE MAIN QUESTION IS HOW LONG IT WILL TAKE FOR A
THUNDERSTORM THREAT TO RETURN. WILL GO WITH A SLIGHT CHANCE
PROJECTED BY GUIDANCE FOR WEDNESDAY NIGHT FAR WEST AS WARM ADVECTION
QUICKLY BEGINS. OTHERWISE IT LOOKS LIKE FRIDAY WILL BE THE RETURN
DAY. THE THREAT MAY THEN DECREASE FOR SATURDAY AS THE UPPER RIDGE
BUILDS INTO OUR AREA. IN ANY EVENT WIDESPREAD PRECIPITATION SEEMS
UNLIKELY WHILE OUR LITTLE SHOT OF RELATIVELY COOL DRY WEATHER IS
FOLLOWED BY ANOTHER WARM UP. HOWEVER IT DOES NOT LOOK LIKE A RETURN
TO LAST SUMMERS HEAT WAVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1231 PM CDT SUN JUL 7 2013
MAINLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. MAY SEE A FEW
ISOLATED STORMS FIRE THIS AFTERNOON AND EVENING...GENERALLY IN THE
VICINITY OF INTERSTATE 90 OR NORTH...AND EAST OF INTERSTATE 29. WILL
LEAVE OUT OF TAFS FOR NOW...SINCE COVERAGE IS EXPECTED TO BE
LOW...AND BEST CHANCE IS EAST OF TAF SITES. A FEW SHOWERS AND STORMS
MAY TRY TO MOVE INTO AREAS WEST OF THE JAMES RIVER THIS EVENING INTO
THE OVERNIGHT. BUT THE CHANCE OF THIS IS TOO LOW TO INCLUDE IN THE
KHON TAF AT THIS TIME. BRIEF REDUCTIONS TO MVFR OR IFR WILL BE
POSSIBLE IN ANY THUNDERSTORM. IF SKIES CLEAR TONIGHT...COULD BE SOME
PATCHY AREAS OF MVFR FOG LIKE LAST NIGHT...WILL NOT PUT ANY MENTION
IN THE TAFS FOR NOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1056 AM CDT SUN JUL 7 2013
.UPDATE...
ISSUED AT 1054 AM CDT SUN JUL 7 2013
INTERESTING FORECAST FOR TODAY. WEAK UPPER WAVE GENERATING AN AREA
OF ELEVATED SHOWERS AND STORMS ACROSS CENTRAL SOUTH DAKOTA THIS
MORNING. AS THIS WAVE MOVES EAST OUR CWA WILL SEE WEAK UPPER FORCING
FOR ASCENT. EXPECT CIRRUS FROM THIS ACTIVITY TO WORK ITS WAY INTO
OUR WESTERN CWA AS WE HEAD INTO THIS AFTERNOON. MEANWHILE FRONTAL
BOUNDARY IS TAKING ITS SLOW TIME MOVING SOUTH ACROSS OUR CWA. SO
QUESTION BECOMES WHAT ARE OUR CONVECTION CHANCES THIS AFTERNOON. A
COUPLE THINGS TO WATCH WILL BE DEWPOINT EVOLUTION AND CONVECTIVE
EVOLUTION ACROSS CENTRAL AND WESTERN SOUTH DAKOTA.
MOISTURE POOLING BEHIND THE FRONT IS CURRENTLY ALLOWING DEWPOINTS TO
CREEP INTO THE LOW 70S IN SPOTS. A LOT OF GUIDANCE SUGGEST THESE
DEWPOINTS MAY STRUGGLE TO MIX OUT...WITH RELATIVELY DEEP MOISTURE
PRESENT UP TO ABOUT 850 MB...AND WEAK FLOW. AS TEMPERATURES RISE
INTO THE 80S THIS AFTERNOON...MLCAPE COULD END UP IN THE 2000 TO
3000 J/KG RANGE IN THE AREA OF MOISTURE POOLING. CIN WOULD ALSO
BECOME ALMOST ZERO. HOWEVER A VERY DRY LAYER AROUND 700 MB WILL
LIKELY HINDER UPDRAFTS SOMEWHAT...AND DESPITE THE BOUNDARY
NEARBY...SEE VERY LITTLE IN THE WAY OF LOW LEVEL CONVERGENCE OR
FORCING FOR ASCENT. SO IT WOULD COME DOWN TO WHETHER THE INSTABILITY
AND WEAK UPPER FORCING WOULD BE ENOUGH TO GET DEEP CU THROUGH THE
DRY AIR. HI RES GUIDANCE...SUCH AS THE 06Z WRF ARW AND 12Z 4KM NAM
BOTH SUGGEST THIS MAY HAPPEN. THUS WENT AHEAD AND ADDED IN A SLIGHT
CHANCE OF STORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF OUR
CWA. AGAIN THIS IS REALLY DEPENDENT ON IF WE CAN KEEP DEWPOINTS IN
THE LOWER 70S. IF THEY FAIL TO MATERIALIZE...THEN DRY AIR ALOFT AND
WARM LAYER BETWEEN 800 AND 600 MB WILL LIKELY BE ENOUGH TO CAP
CONVECTION. WIND SHEAR IS WEAK...THUS ANY STORM WOULD BE PULSE OR
POSSIBLY MULTICELL TYPE. BUT GIVEN WHAT WOULD BE HIGH
INSTABILITY...WOULD EXPECT AT LEAST THE THREAT OF QUARTER SIZE HAIL
AND 60 MPH WIND GUSTS IN ANY STORM. HRRR DEVELOPS CONVECTION IN
CENTRAL SOUTH DAKOTA THIS AFTERNOON...AND MOVES IT INTO OUR WESTERN
CWA LATER THIS AFTERNOON AND EVENING. GIVEN EXTENSIVE CLOUD COVER IN
THIS AREA...FEEL SURFACE BASED INITIATION IN CENTRAL SOUTH DAKOTA IS
UNLIKELY THIS AFTERNOON...THUS BELIEVE THE HRRR SOLUTION IS PROBABLY
NOT ACCURATE...AND SO WILL HOLD OFF ON ADDING IN ANY POPS IN OUR
WEST THROUGH 0Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM CDT SUN JUL 7 2013
TODAY AND MUCH OF TONIGHT SHOULD REMAIN QUIET IN OUR AREA DESPITE
MESSY...WAVE-RIDDLED MID LEVEL FLOW PATTERN BETWEEN DOMINANT RIDGE
BUILDING WESTWARD ACROSS THE SOUTHERN CONUS AND VARIOUS TROUGHS
TRACKING EASTWARD THROUGH THE CANADIAN PRAIRIES. IN THE NEAR TERM...
SEEING SOME ACCAS AND SPOTTY SHOWERS DEVELOP IN WESTERN IOWA AHEAD OF
WEAK WAVE. SHOWERS ARE NOT EXPECTED TO IMPACT OUR FORECAST AREA THIS
MORNING THOUGH COULD SEE A LITTLE OF THE ACCAS IN OUR FAR EAST EARLY
BEFORE WEAK WAVE PASSES BY. WEAK SURFACE BOUNDARY STILL WEST OF I-29
AS OF 08Z MOVING SOUTHEAST MORE SLOWLY THAN EXPECTED AT THIS TIME
YESTERDAY...THOUGH STILL EXPECTED TO MAKE SOME EASTWARD PROGRESS
THROUGH THE DAY...REACHING NEAR/JUST EAST OF HIGHWAY 60 CORRIDOR
IN NORTHWEST IOWA BY LATE AFTERNOON. WITH WEAK LOW LEVEL
FLOW...EXPECT HIGHER MOISTURE LEVELS TO POOL NEAR THE
BOUNDARY...WITH DEW POINTS IN NORTHWEST IOWA NEAR 70 WHILE
TEMPERATURES CLIMB INTO THE LOWER 90S THIS AFTERNOON. THIS SHOULD
LEAD TO FAIR AMOUNT OF INSTABILITY WHICH COULD POP A STRAY STORM
OR TWO WITH WEAK CONVERGENCE ALONG THE BOUNDARY TOWARD EVENING.
WILL HANG ONTO SLIGHT CHANCE FOR NOW...BUT IF SOME HIGH RES MODELS
SUCH AS RAP/HRRR TURN OUT TO BE ACCURATE IN THEIR DEPICTION OF DEW
POINTS MIXING MUCH LOWER THAN EXPECTED ACROSS OUR SOUTHEAST THIS
AFTERNOON...THEN CAP WOULD BE STRONGER AND WOULD NOT SEE ANY
DEVELOPMENT. WILL BE SOMETHING TO WATCH THROUGH THE DAY.
LATER TONIGHT...WILL BE LOOKING WESTWARD FOR POTENTIAL OF HIGH PLAINS
CONVECTION TO WORK TOWARD OUR WESTERN COUNTIES. STILL FAIR AMOUNT OF
INSTABILITY FOR STORMS TO WORK WITH AS THEY PUSH TOWARD THE MISSOURI
VALLEY AFTER MIDNIGHT. WILL CONTINUE TO CARRY CHANCE INTO AREAS ALONG
AND WEST OF THE JAMES VALLEY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 430 AM CDT SUN JUL 7 2013
IF STORMS DO WORK INTO THE WEST LATE TONIGHT...SHOULD SEE THEM LINGER
INTO THE MORNING HOURS ACROSS OUR WEST AND WILL HANG ONTO CHANCE WEST
OF I-29 FOR NOW. HOWEVER THIS PERIOD COULD JUST AS LIKELY BE DRY...AS
SOME MODELS INDICATING HIGH PLAINS CONVECTION WILL NOT SURVIVE THIS
FAR EAST. ALL-IN-ALL...LOW CONFIDENCE IN PRECIP CHANCES ACROSS OUR
WEST LATE TONIGHT/MONDAY MORNING. CONFIDENCE SOMEWHAT HIGHER THAT WE
WILL SEE DEVELOPMENT ACROSS OUR SOUTH BY MID-LATE AFTERNOON MONDAY...
AS WARM FRONT LIFTS BACK TO NEAR THE MISSOURI RIVER VALLEY AND MID
LEVEL HEIGHTS COLLAPSE IN ADVANCE OF APPROACHING WAVE. WITH LITTLE
FLOW NEAR THE BOUNDARY...SHOULD CONTINUE TO SEE LOW LEVEL MOISTURE
BUILD AND ENHANCE INSTABILITY. ALSO START TO SEE BETTER DEEP LAYER
SHEAR WORK INTO THE REGION...LOCALLY ENHANCED ALONG THE BOUNDARY. FOR
THIS REASON...MONDAY AFTERNOON/EVENING LOOKS TO HAVE FAIR POTENTIAL
FOR SEVERE STORMS AS WAVE /IN SOME MODELS/ SLIDES NORTHEAST ACROSS
THE FRONTAL BOUNDARY.
EVOLUTION OF PRECIP BEYOND THIS SOMEWHAT MUDDLED BY POTENTIAL FOR
LINGERING OUTFLOW BOUNDARIES...BUT GENERALLY EXPECT MOST MONDAY NIGHT
ACTIVITY TO WORK EAST OF THE FORECAST AREA BY EARLY TUESDAY. COLD
FRONT WILL BE PUSHING SOUTHEAST THROUGH THE FORECAST AREA TUESDAY
AFTERNOON...AND EXPECT STRONG WARMING INTO THE LOWER TO MID 90S IN
THERMAL RIDGE AHEAD OF THE FRONT. HUMIDITY LINGERS AS WELL...WITH DEW
POINTS IN THE LOWER OR EVEN MID 70S POSSIBLE ACROSS MUCH OF THE AREA.
THIS WILL GIVE FRONT PLENTY OF INSTABILITY TO FEED ON...WITH STORM
DEVELOPMENT AIDED BY SOUTHERN EXTENT OF MAIN UPPER TROUGH WORKING
THROUGH THE NORTHERN PLAINS. WITH CURRENT FORECAST SPEED OF TROUGH
AND SURFACE BOUNDARY...STORMS SHOULD CLEAR MOST OF THE AREA BY 00Z
THOUGH WILL HOLD ONTO A CHANCE EAST OF HIGHWAY 60 INTO THE EVENING
SHOULD SYSTEM SLOW DOWN A BIT.
EARLIER PROJECTED DRY AND COOLER DAY FOR WEDNESDAY STILL ON SCHEDULE
BEHIND COLD FRONT...AS HIGH PRESSURE MOVES INTO THE NORTHERN PLAINS.
UPPER RIDGING UNANIMOUSLY PROGGED TO RETURN LATER IN THE WEEK WITH A
SLOW INCREASE IN TEMPERATURES AND HUMIDITY AS SURFACE HIGH MOVES
EAST OF OUR AREA. THE MAIN QUESTION IS HOW LONG IT WILL TAKE FOR A
THUNDERSTORM THREAT TO RETURN. WILL GO WITH A SLIGHT CHANCE
PROJECTED BY GUIDANCE FOR WEDNESDAY NIGHT FAR WEST AS WARM ADVECTION
QUICKLY BEGINS. OTHERWISE IT LOOKS LIKE FRIDAY WILL BE THE RETURN
DAY. THE THREAT MAY THEN DECREASE FOR SATURDAY AS THE UPPER RIDGE
BUILDS INTO OUR AREA. IN ANY EVENT WIDESPREAD PRECIPITATION SEEMS
UNLIKELY WHILE OUR LITTLE SHOT OF RELATIVELY COOL DRY WEATHER IS
FOLLOWED BY ANOTHER WARM UP. HOWEVER IT DOES NOT LOOK LIKE A RETURN
TO LAST SUMMERS HEAT WAVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 638 AM CDT SUN JUL 7 2013
ISOLATED PATCHES OF 3-5SM BR WILL DISSIPATE BY 14Z. OTHERWISE
GENERA LY VFR THROUGH 08/09Z. ISOLATED TSRA EAST AND SOUTH OF FSD
07/00Z-06Z AND WEST OF MHE/HON 08/06Z-12Z WITH VERY LOCAL AND
BRIEF LOWERING OF CEILINGS TO 2-3K FEET AND VISIBILITIES TO 3-5SM
IN TSRA. EXPECTED COVERAGE OF CONVECTION TOO LIGHT TO INCLUDE IN
TAFS AT THIS TIME ESPECIALLY SINCE ALL IS EXPECTED AFTER 08/00Z.
AFT 08/09Z LCL VISIBILITIES 3-5SM/BR POSSIBLE BUT AGAIN EXPECTED
TO BE VERY PATCHY SO NOT AT THIS TIME INCLUDED IN TAF FORECASTS.
$$
SHORT TERM...
LONG TERM...
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
630 PM CDT MON JUL 8 2013
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS WITH LIGHT WINDS GUSTING IN THE AFTERNOON THROUGH
THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 229 PM CDT MON JUL 8 2013/
DISCUSSION...
AN UPPER LEVEL DISTURBANCE PASSING BY TO THE SOUTH ACROSS THE BIG
BEND COULD GENERATE ISOLATED THUNDERSTORMS THIS EVENING ACROSS
WEST TEXAS PER CUMULUS FIELD AND LATEST RUC GUIDANCE. ANY ACTIVITY
SHOULD DIE THIS EVENING WITH LOSS OF HEATING. THIS DISTURBANCE
IS FORECAST TO CONTINUE TO SLOWLY TRACK WESTWARD ACROSS NORTHERN
MEXICO TUESDAY AND TUESDAY EVENING WITH ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS POSSIBLE AGAIN ACROSS THE BIG BEND...DAVIS
MOUNTAINS AND LOWER TRANS PECOS REGION CLOSEST TO THE TRACK OF
DISTURBANCE. BEYOND TUESDAY A SPRAWLING UPPER LEVEL HIGH PRESSURE
AREA ACROSS THE PLAINS AND ROCKIES SHOULD REGAIN FIRM CONTROL OF
THE REGION AND PRECIPITATION CHANCES WILL BE VERY LOW. THE NEXT
CHANCE OF CONVECTION APPEARS TO BE NEXT SUNDAY AND MONDAY AS
ANOTHER DISTURBANCE TRACKS WESTWARD ACROSS THE GULF AND MEXICO.
HIGH TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL THROUGH WEDNESDAY
WITH ABOVE NORMAL TEMPERATURES EXPECTED THURSDAY THROUGH SATURDAY.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
344 PM CDT SUN JUL 7 2013
.SHORT TERM...
A FLATTENED AND QUASI-ZONAL UA RIDGE HAS SHIFTED TO THE SOUTHERN
PLAINS...WITH THE CENTER DRAPED FROM THE SOUTHERN PLAINS TO WRN NM.
A PLUME OF PACIFIC MOISTURE CONTINUED TO SPILL ACROSS THE CWA
RESULTING IN FEW-SCT HIGH LEVEL CLOUDINESS. MID-UPPER LEVEL
THICKNESS VALUES ARE SLIGHTER LOWER THAN YESTERDAY DURING THIS
TIME...BUT WARM TEMPS STILL PREVAILED WITH HIGHS IN THE UPPER 80S TO
LOWER 90S ON THE CAPROCK TO LOWER TO MID 90S OFF THE CAPROCK A SFC
TROUGH WAS LOCATED FROM SWRN KS TO SOUTH CENTRAL NM...THOUGH THE
PRESSURE GRADIENT WAS NOT AS STRONG AS PREVIOUS DAYS AND THUS SRLY
WIND SPEEDS WERE NOT OVERLY BREEZY LATE THIS AFTN /10-20 MPH/. THE
CO-EXISTENCE OF THE AFOREMENTIONED SFC TROUGH WITH THE BEST THETA-E
AXIS...IN ADDITION TO OROGRAPHIC INFLUENCES AND DAYTIME
DESTABILIZATION...CAUSED THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE HIGHER MOUNTAINOUS TERRAIN OF ERN NM AND
SERN CO. WITH THE UA RIDGE TAKING UP RESIDENCE ACROSS THE SOUTHERN
PLAINS...STEERING FLOW IS RATHER WEAK WHICH WILL MAKE MOUNTAINOUS
AREA STORMS HARD PRESSED TO REACH THE FA /THIS HAS BEEN THE CASE THE
PAST FEW DAYS/. HOWEVER...A FEW ELEVATED LIGHT SHOWERS HAVE
DEVELOPED ACROSS THE FAR SWRN TEXAS PANHANDLE...COINCIDING WITH
ADEQUATE ALBEIT WEAK MID-LEVEL MOISTURE CONVERGENCE. THE RUC HAS
PICKED UP ON THIS SIGNAL WITH HINTS OF IT EXPANDING TO THE NWRN
ZONES LATER THIS AFTN...BEFORE WANING AOA SUNSET.
THE PLUME OF PACIFIC MOISTURE TRAPPED BENEATH THE RIDGE WILL ENSUE
TONIGHT...ALTHOUGH IT IS PROGGED TO THIN AND BE CONFINED TO THE WRN
PANHANDLES AND FAR NWRN ZONES. MID-LEVEL ASCENT ACROSS THE SAID
AREA ARE NOT THAT IMPRESSIVE...BUT MODELS DO EXHIBIT LIGHT QPF
SIGNALS NEAR THE TX/NM BORDER OR JUST WEST OF THE CWA. DUE TO RECENT
NIGHTS OF NOCTURNAL ACTIVITY...WILL GO AHEAD AND RAISE POPS TO
MENTIONABLE LEVELS ACROSS THE FAR NWRN ZONES. WEAKENED OVERNIGHT LLJ
EQUATES RELATIVELY LIGHT SERLY SFC WINDS...BUT MILD TEMPS ARE STILL
ANTICIPATED /MID 60S NW TO 70S EAST/. TOMORROW...UA RIDGING AND WARM
TEMPS WILL ENSUE /LOW TO MID 90S ON THE CAPROCK TO MID UPPER 90S OFF
THE CAPROCK/ THOUGH THE CENTER OF THE RIDGE WILL RETROGRADE TO AZ/NM
WHILST A GULF OF MEXICO WEAKNESS TREKS WNW ACROSS SRN TX. NOT
EXPECTING THIS WEAKNESS TO PROVIDE THE CWFA WITH ANY MAJOR CHANGES
WITH REGARD TO SENSIBLE WX...WITH THE EXCEPTION OF DEWPOINTS
INCREASING INTO THE LOW 60S AND NEARING MID-LEVEL CLOUDINESS FOR THE
FAR SERN ZONES. PLUME OF PACIFIC MOISTURE WILL ALSO SHIFT WEST TO
MORE SO ACROSS NM WHERE BEST PRECIP CHANCES WILL RESIDE. /29
&&
.LONG TERM...
FEW CHANGES ONCE AGAIN THIS FORECAST PACKAGE...AS THE LARGE UPPER
LEVEL HIGH PRESSURE RIDGE WILL DOMINATE OUR WEATHER THROUGH THE
WEEK AND LIKELY THE WEEKEND AS WELL. PRECIPITATION SIGNALS THIS
COMING WEEK ARE HARD TO COME BY...THOUGH ONE WE ARE SEEING
CONSISTENTLY IS IN THE LATE WEDNESDAY AND EARLY THURSDAY TIME-
FRAME AS A WAVE DIGS INTO THE NORTHERN GREAT LAKES WITH A
WEAKENING SURFACE FRONTAL BOUNDARY LURCHING SLOWLY SOUTHWARD. THE
LATEST RUNS DO NOT APPEAR TO WEAKEN THE RIDGE VERY MUCH AND
STEERING FLOW SHOULD REMAIN VERY WEAK. BUT SOLUTIONS HAVE BEEN
PAINTING THUNDER DEVELOPMENT NEAR THIS BOUNDARY ACROSS THE TEXAS
PANHANDLE INTO WESTERN OKLAHOMA...AND EVEN VERY NEAR THE RED RIVER
BY EARLY THURSDAY. BULK OF SOLUTIONS...HOWEVER...APPEAR TO BOUND
THE ACTIVITY JUST TO THE NORTH AND EAST OF THE NORTHERN ROLLING
PLAINS. WE WILL RETAIN THE JUST SUB-MENTIONABLE LEVEL OF
PRECIPITATION UNTIL WE SEE MORE SIGNALS WITHIN OUR AREA. FOLLOWING
THIS WAVE...THE UPPER RIDGE STILL APPEARS TO SPRING BACK TO THE
NORTH AND EAST...CENTERED JUST TO OUR NORTH FOR THE END OF THE
WEEK INTO THE EARLY WEEKEND. THIS STILL SHOULD ACCOUNT FOR
SLIGHTLY HOTTER TEMPERATURES AND WE HAVE BOOSTED HIGHS A DEGREE OR
TWO ABOVE THE PREVIOUS FORECAST. FINALLY...BY LATE IN THE WEEKEND
THE RIDGE IS EXPECTED TO RETROGRADE TO OUR WEST AS A SOUTHWESTWARD
MOVING UPPER LOW TRAVERSES THE DEEP SOUTH PERHAPS CROSSING WEST OF
THE MISSISSIPPI BY MONDAY. LOTS OF QUESTIONS ABOUT THIS PATTERN...
THOUGH SOME LEVEL OF COOLING ALONG WITH A MOISTURE INCREASE SEEM
FAIRLY CERTAIN. MOST OF THE REAL CHANGES... HOWEVER...WILL BE IN
DAY 8 AND BEYOND. STAY TUNED. RMCQUEEN
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 66 93 67 95 67 / 20 10 10 10 10
TULIA 66 95 69 97 69 / 10 10 10 10 10
PLAINVIEW 67 93 69 96 69 / 10 10 10 10 10
LEVELLAND 67 94 68 94 68 / 10 10 10 10 10
LUBBOCK 69 96 70 96 70 / 10 10 10 10 10
DENVER CITY 68 94 67 93 67 / 10 10 10 10 10
BROWNFIELD 69 94 67 95 68 / 10 10 10 0 10
CHILDRESS 70 98 73 100 74 / 0 0 0 0 10
SPUR 70 97 71 97 71 / 0 0 0 0 10
ASPERMONT 71 98 72 100 73 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/05
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1242 PM CDT SUN JUL 7 2013
.AVIATION...
WITH OVERALL POP BEING ABOUT 20 PERCENT THIS AFTERNOON ACROSS THE
I-35 CORRIDOR...HAVE REMOVED MENTION OF SH/TS IN THE SHORT TERM IN
THE AUS/SAT/SSF TAFS. SEABREEZE ACTIVITY IS EXPECTED TO FIRE UP
TO THE SOUTHEAST THIS AFTERNOON BUT STILL QUESTIONABLE WHETHER IT
WILL MAKE IT THIS FAR INLAND. SCT CLOUDS EXPECTED ALTHOUGH FOR THE
REMAINDER OF THE AFTERNOON COULD SEE SOME CIG DECKS FROM TIME TO
TIME BUT SHOULD BE AROUND 5KFT OR SO.
WITH PRECIPITABLE WATER INCREASING TO OVER 2 INCHES
TOMORROW...HAVE INPUT SOME VCSH FOR THE MORNING HOURS AND ADDED A
PROB30 GROUP IN THE 30 HOUR TAFS OF AUS/SAT FOR THE POSSIBILITY OF
AFTERNOON SHOWERS AND STORMS. SOME MVFR CIGS ARE ONCE AGAIN
EXPECTED IN THE EARLY-LATE MORNING. CLOUDS SHOULD BE A BIT MORE
NUMEROUS ON MONDAY ESPECIALLY IN THE AFTERNOON WITH THE DEEPER
MOISTURE AND DEBRIS CLOUDS FROM NEARBY CB. LEFT DRT TAF DRY FOR
NOW AS CONFIDENCE IS LOW ON HOW FAR WEST THE MOISTURE WILL PUSH BY
18Z MON. AM THINKING BEST CHANCES FOR DRT WILL OCCUR LATER ON MON
AFTERNOON AND MON NIGHT.
&&
.PREV DISCUSSION... /ISSUED 1051 AM CDT SUN JUL 7 2013/
UPDATE...
MINOR ADJUSTMENTS TO FIRST PERIOD.
DISCUSSION...
MORNING SOUNDINGS INDICATE PW VALUES HAVE INCREASED BY .25 TO .5
INCHES ACROSS THE AREA AS COMPARED TO 24 HRS AGO. MOISTURE WILL
CONTINUE TO INCREASE AS THE UPPER LOW IN THE NWRN GULF PROGRESSES
ONSHORE LATER TODAY. ISOLATED SHOWERS AND THUNDERSTORMS HAVE
PUSHED INTO THE COASTAL PLAINS THIS MORNING...AND SHOULD INCREASE
IN COVERAGE ONCE DIURNAL HEATING BECOMES A FACTOR. ONGOING
FORECAST IS GENERALLY ON TRACK. ONLY MINOR ADJUSTMENTS WERE MADE
TO FIRST-PERIOD POPS/WX/QPF AND TEMPERATURES. NEW ZONES WILL BE
OUT SHORTLY.
PREV DISCUSSION... /ISSUED 641 AM CDT SUN JUL 7 2013/
UPDATE...
SEE AVIATION FOR 12Z TAF DISCUSSION.
AVIATION...
A TROPICAL AIR MASS AND A MOSTLY ELEVATED LOW PRESSURE TROUGH
MOVING INTO THE TX COAST WILL DISRUPT THE OCCASIONAL MVFR CIG THIS
MORNING. WITH LIGHT WINDS AND BUOYANT AIR IN THE AREA...SCT LOW
BASED CUMULUS OF AROUND 1500 FT WILL HAVE TOPS LIFTING TO 10000 FT
OR HIGHER AS LIGHT SHOWERS BEGIN TO MOVE TOWARD THE I-35
TERMINALS. WILL LEAVE OUT MENTION OF MVFR CIGS UNTIL THE BETTER
CHANCE OF RAINS ARRIVE IN THE EARLY AFTERNOON HOURS AS DEPICTED BY
THE HRRR SIMULATED REFLECTIVITY. ANY FEEBLE ATTEMPT TO DEVELOP A
SURFACE CIRCULATION EAST OF BRO SHOULD BE HELD IN CHECK AS THE
UPPER SUPPORT PUSHES ONSHORE BY TONIGHT. THUS WILL PLAN ON A MORE
STEADY ONSHORE WIND BY TONIGHT...AND A MORE ROUTINE FORMATION OF
LOW CLOUDS AT AROUND 09Z. HIGH PWAT VALUES COULD SUPPORT
ADDITIONAL SHOWERS AROUND DAYBREAK...BUT WILL LEAVE OUT OF THE
LATE PERIODS OF THE TAFS UNTIL A BETTER TREND CAN BE ESTABLISHED.
PREV DISCUSSION... /ISSUED 322 AM CDT SUN JUL 7 2013/
SHORT TERM (TODAY THROUGH MONDAY)...
A WEAKENED UPPER LEVEL INVERTED TROUGH FEATURE OVER THE WESTERN GULF
OF MEXICO WILL MIGRATE WEST ONTO THE TEXAS COASTAL PLAINS REGION
TODAY WITH AN ENHANCEMENT OF SEA BREEZE ACTIVITY LIKELY OVER
SOUTHERN AND EASTERN PORTIONS OF THE CWA. HIGH TEMPERATURES TODAY
WILL LOWER SLIGHTLY WITH THE INCREASING SURFACE BASED MOISTURE.
HIGHS TODAY WILL RANGE FROM THE LOW 90S ACROSS PORTIONS OF THE HILL
COUNTRY TO THE MID TO UPPER 90S ELSEWHERE. INCREASING CLOUDINESS
TONIGHT WITH A SLIGHT CHANCE OF MOSTLY EARLY EVENING SHOWERS AND
STORMS SOUTH AND EAST. LOWS IN THE 70S. THE UPPER TROUGH WILL MOVE
ACROSS THE AREA MONDAY WITH DEEP...MOIST TROPICAL EASTERLIES
BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT MUCH OF
THE AREA. HIGHS MONDAY WILL MODERATE BACK INTO THE LOWER 90S MOST
LOCATIONS WITH NEAR 90 HILL COUNTRY.
LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
SHOWERS AND STORMS WILL DIMINISH MONDAY EVENING AS THE INVERTED
UPPER TROUGH PUSHES DEEPER INTO MEXICO. LOWS MONDAY NIGHT AGAIN
MOSTLY IN THE 70S WITH NEAR 70 HILLS. UPPER LEVEL RIDGING WILL BUILD
BACK OVER THE REGION TUESDAY AND REMAIN STRONG THROUGH SATURDAY AS
THE CENTER OF THE HIGH SHIFTS EAST INTO THE SOUTHERN PLAINS BY LATE
IN THE WEEK. CONTINUED DEEP EASTERLIES HOWEVER IN THE MID AND LOWER
LEVELS OF THE ATMOSPHERE WILL ENHANCE SOME SEA BREEZE CONVECTION
INTO EASTERN SECTIONS BOTH TUESDAY AND WEDNESDAY. MORNING LOW CLOUDS
WILL BECOME PARTLY CLOUDY AFTERNOONS BOTH DAYS WITH HIGHS RANGING
FROM THE LOW 90S HILLS TO THE UPPER 90S TO NEAR 100 EASTERN SECTIONS.
LOWS IN THE 70S. ANOTHER EASTERLY WAVE FEATURE PUSHING ACROSS THE
COASTAL PLAINS THURSDAY WILL GENERATE MORE ACTIVITY OVER EASTERN
SECTIONS BOTH THURSDAY AND FRIDAY. HIGHS WILL CONTINUE NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS THURSDAY THROUGH SATURDAY. LOWS
GENERALLY IN THE 70S EXCEPT UPPER 60S TO NEAR 70 HILLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 97 75 94 74 100 / 20 20 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 96 74 93 72 99 / 20 20 30 10 -
NEW BRAUNFELS MUNI AIRPORT 95 73 93 72 96 / 20 20 30 10 10
BURNET MUNI AIRPORT 94 74 91 73 96 / 10 10 20 10 -
DEL RIO INTL AIRPORT 97 76 92 75 94 / - - 30 20 10
GEORGETOWN MUNI AIRPORT 95 74 93 72 98 / 20 10 20 10 -
HONDO MUNI AIRPORT 96 74 90 73 96 / 20 10 30 20 -
SAN MARCOS MUNI AIRPORT 96 74 93 73 97 / 20 20 30 10 10
LA GRANGE - FAYETTE REGIONAL 94 76 92 75 99 / 40 20 30 10 20
SAN ANTONIO INTL AIRPORT 94 76 91 75 96 / 20 20 30 10 -
STINSON MUNI AIRPORT 95 74 92 73 94 / 20 20 30 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1221 PM CDT SUN JUL 7 2013
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD. SLIGHTLY
BREEZY SRLY WINDS /10-12 KTS/ WILL DECLINE FURTHER SHORTLY AFTER
SUNSET. FEW-SCT CLOUD DECKS THIS AFTN WILL BECOME SKC OVERNIGHT
THROUGH TOMORROW.
&&
PREV DISCUSSION... /ISSUED 343 AM CDT SUN JUL 7 2013/
SHORT TERM...
DIRTY SOUTHWESTERN RIDGE HAS EXPANDED TO ENCOMPASS WEST TEXAS AND
THIS WILL PROVIDE ANOTHER TOASTY JULY DAY WITH HIGHS SIMILAR TO
SATURDAY. MID-LEVEL MOISTURE SPILLING OVER THE SOUTH PLAINS COUPLED
WITH WEAK ELEVATED INSTABILITY...DEEP LAYER MOISTURE CONVERGENCE AND
ELEVATED FRONTOGENESIS WERE SUPPORTING A FEW RECENTLY DEVELOPED
SHOWERS AND STORMS ACROSS THE FAR NORTHWESTERN ZONES. THIS ACTIVITY
WAS NOT MOVING MUCH THANKS TO WEAK STEERING FLOW/WINDS WITHIN THE
RIDGE...BUT WE COULD SEE AT LEAST ISOLATED ACTIVITY HANG ON ACROSS
THE WESTERN ZONES AND PERHAPS EXPAND/DEVELOP TOWARD THE I-27/US-87
CORRIDOR AS THE RECENT RAP AND HRRR RUNS SUGGEST. HENCE HAVE
INSERTED A SLIGHT CHANCE OF THUNDERSTORMS INTO THE GRIDS ACROSS THE
WESTERN AND INTO THE CENTRAL ZONES IN THE 12-18Z TIME-FRAME. ANY
ACTIVITY WILL LIKELY WANE TOWARD MID TO LATE MORNING. STRONG HEATING
AND SUFFICIENT MOISTURE WILL THEN YIELD ANOTHER ROUND OF CONVECTION
OVER THE HIGHER TERRAIN OF NM AND CO THIS AFTERNOON...BUT SIMILAR TO
SATURDAY...THIS ACTIVITY WILL NOT HAVE MUCH INCENTIVE TO MOVE VERY
FAR EASTWARD AND SHOULD STAY WELL WEST OF THE CWA. THE MID-LEVEL
MOISTURE PLUME WILL STILL EXTEND IN CLOSE PROXIMITY TO THE FAR
NORTHWESTERN ZONES LATE TONIGHT AND THERE MAY BE SOME RISK OF LATE
NIGHT ELEVATED CONVECTIVE DEVELOPMENT LIKE WE HAVE SEEN THE LAST
COUPLE OF NIGHTS. HOWEVER THE MID-LEVEL MOISTURE PLUME IS PROGGED TO
THIN/DRY A BIT LOCALLY AND LOW-LEVEL FORCING APPEARS LESS...SO HAVE
KEPT THE FORECAST DRY FOR TONIGHT. OTHERWISE...IT WILL BE ANOTHER
MILD NIGHT WITH LOWS VARYING FROM THE MID-60S NORTHWEST TO LOWER AND
MIDDLE 70S EAST.
LONG TERM...
AN UPPER LEVEL RIDGE...CENTERED ROUGHLY OVER THE 4-CORNERS INITIALLY...
AND GRADUALLY MIGRATING INTO THE CENTRAL HIGH PLAINS...WILL KEEP
THE FA HOT AND DRY FOR THE MOST PART THIS UPCOMING WEEK.
OROGRAPHICALLY FORCED CONVECTION WITHIN MOISTURE PLUME TRAPPED IN
THE RIDGE SHOULD REMAIN TO OUR WEST MONDAY WHILE AN INVERTED
TROUGH MOVING WEST ACROSS THE BIG BEND WILL BE OF LITTLE
CONSEQUENCE TO OUR WX. WE ARE STILL WATCHING FOR A TEMPORARY
WEAKNESS TO DEVELOP IN THE EASTERN PART OF THE RIDGE WED/THU AS A
SHORTWAVE MOVES FROM THE CANADIAN PRAIRIES TO THE GREAT LAKES AND
A COLD FRONT DIPS INTO SRN CO/SW KS. BUT ANY TSTM ACTIVITY
ASSOCIATED WITH THIS WAVE/FRONT APPEARS UNLIKELY TO MAKE IT INTO
OUR NRN ZONES LATE WED/EARLY THU. THEN...AS THE UPPER RIDGE RE-
EXPANDS E-NEWD WE EXPECT TEMPS TO NUDGE UPWARD A FEW DEGREES
HEADING INTO NEXT WEEKEND. EARLY NEXT WEEK...THE UPPER RIDGE MAY
START TO RETROGRADE BACK TO THE WEST AS AN UPPER TROUGH/LOW
DEVELOPS IN THE DEEP SOUTH. WE ARE COUNTING ON THIS PATTERN CHANGE
TO BRING A COOLING TREND AND PERHAPS A CHANCE OF RAIN NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 66 93 66 95 67 / 10 10 10 10 10
TULIA 67 95 68 96 69 / 10 10 10 10 10
PLAINVIEW 67 95 69 95 69 / 10 10 10 10 10
LEVELLAND 68 94 70 94 69 / 10 10 10 10 10
LUBBOCK 70 95 70 95 71 / 10 10 10 10 10
DENVER CITY 68 93 69 93 67 / 10 10 10 10 10
BROWNFIELD 69 94 70 95 69 / 10 10 10 0 10
CHILDRESS 71 98 74 99 75 / 0 0 0 0 10
SPUR 71 96 72 97 72 / 0 0 0 0 10
ASPERMONT 72 97 74 99 75 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1051 AM CDT SUN JUL 7 2013
.UPDATE...
MINOR ADJUSTMENTS TO FIRST PERIOD.
&&
.DISCUSSION...
MORNING SOUNDINGS INDICATE PW VALUES HAVE INCREASED BY .25 TO .5
INCHES ACROSS THE AREA AS COMPARED TO 24 HRS AGO. MOISTURE WILL
CONTINUE TO INCREASE AS THE UPPER LOW IN THE NWRN GULF PROGRESSES
ONSHORE LATER TODAY. ISOLATED SHOWERS AND THUNDERSTORMS HAVE
PUSHED INTO THE COASTAL PLAINS THIS MORNING...AND SHOULD INCREASE
IN COVERAGE ONCE DIURNAL HEATING BECOMES A FACTOR. ONGOING
FORECAST IS GENERALLY ON TRACK. ONLY MINOR ADJUSTMENTS WERE MADE
TO FIRST-PERIOD POPS/WX/QPF AND TEMPERATURES. NEW ZONES WILL BE
OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT SUN JUL 7 2013/
UPDATE...
SEE AVIATION FOR 12Z TAF DISCUSSION.
AVIATION...
A TROPICAL AIR MASS AND A MOSTLY ELEVATED LOW PRESSURE TROUGH
MOVING INTO THE TX COAST WILL DISRUPT THE OCCASIONAL MVFR CIG THIS
MORNING. WITH LIGHT WINDS AND BUOYANT AIR IN THE AREA...SCT LOW
BASED CUMULUS OF AROUND 1500 FT WILL HAVE TOPS LIFTING TO 10000 FT
OR HIGHER AS LIGHT SHOWERS BEGIN TO MOVE TOWARD THE I-35
TERMINALS. WILL LEAVE OUT MENTION OF MVFR CIGS UNTIL THE BETTER
CHANCE OF RAINS ARRIVE IN THE EARLY AFTERNOON HOURS AS DEPICTED BY
THE HRRR SIMULATED REFLECTIVITY. ANY FEEBLE ATTEMPT TO DEVELOP A
SURFACE CIRCULATION EAST OF BRO SHOULD BE HELD IN CHECK AS THE
UPPER SUPPORT PUSHES ONSHORE BY TONIGHT. THUS WILL PLAN ON A MORE
STEADY ONSHORE WIND BY TONIGHT...AND A MORE ROUTINE FORMATION OF
LOW CLOUDS AT AROUND 09Z. HIGH PWAT VALUES COULD SUPPORT
ADDITIONAL SHOWERS AROUND DAYBREAK...BUT WILL LEAVE OUT OF THE
LATE PERIODS OF THE TAFS UNTIL A BETTER TREND CAN BE ESTABLISHED.
PREV DISCUSSION... /ISSUED 322 AM CDT SUN JUL 7 2013/
SHORT TERM (TODAY THROUGH MONDAY)...
A WEAKENED UPPER LEVEL INVERTED TROUGH FEATURE OVER THE WESTERN GULF
OF MEXICO WILL MIGRATE WEST ONTO THE TEXAS COASTAL PLAINS REGION
TODAY WITH AN ENHANCEMENT OF SEA BREEZE ACTIVITY LIKELY OVER
SOUTHERN AND EASTERN PORTIONS OF THE CWA. HIGH TEMPERATURES TODAY
WILL LOWER SLIGHTLY WITH THE INCREASING SURFACE BASED MOISTURE.
HIGHS TODAY WILL RANGE FROM THE LOW 90S ACROSS PORTIONS OF THE HILL
COUNTRY TO THE MID TO UPPER 90S ELSEWHERE. INCREASING CLOUDINESS
TONIGHT WITH A SLIGHT CHANCE OF MOSTLY EARLY EVENING SHOWERS AND
STORMS SOUTH AND EAST. LOWS IN THE 70S. THE UPPER TROUGH WILL MOVE
ACROSS THE AREA MONDAY WITH DEEP...MOIST TROPICAL EASTERLIES
BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT MUCH OF
THE AREA. HIGHS MONDAY WILL MODERATE BACK INTO THE LOWER 90S MOST
LOCATIONS WITH NEAR 90 HILL COUNTRY.
LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
SHOWERS AND STORMS WILL DIMINISH MONDAY EVENING AS THE INVERTED
UPPER TROUGH PUSHES DEEPER INTO MEXICO. LOWS MONDAY NIGHT AGAIN
MOSTLY IN THE 70S WITH NEAR 70 HILLS. UPPER LEVEL RIDGING WILL BUILD
BACK OVER THE REGION TUESDAY AND REMAIN STRONG THROUGH SATURDAY AS
THE CENTER OF THE HIGH SHIFTS EAST INTO THE SOUTHERN PLAINS BY LATE
IN THE WEEK. CONTINUED DEEP EASTERLIES HOWEVER IN THE MID AND LOWER
LEVELS OF THE ATMOSPHERE WILL ENHANCE SOME SEA BREEZE CONVECTION
INTO EASTERN SECTIONS BOTH TUESDAY AND WEDNESDAY. MORNING LOW CLOUDS
WILL BECOME PARTLY CLOUDY AFTERNOONS BOTH DAYS WITH HIGHS RANGING
FROM THE LOW 90S HILLS TO THE UPPER 90S TO NEAR 100 EASTERN SECTIONS.
LOWS IN THE 70S. ANOTHER EASTERLY WAVE FEATURE PUSHING ACROSS THE
COASTAL PLAINS THURSDAY WILL GENERATE MORE ACTIVITY OVER EASTERN
SECTIONS BOTH THURSDAY AND FRIDAY. HIGHS WILL CONTINUE NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS THURSDAY THROUGH SATURDAY. LOWS
GENERALLY IN THE 70S EXCEPT UPPER 60S TO NEAR 70 HILLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 97 75 94 74 100 / 20 20 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 96 74 93 72 99 / 20 20 30 10 -
NEW BRAUNFELS MUNI AIRPORT 95 73 93 72 96 / 20 20 30 10 10
BURNET MUNI AIRPORT 94 74 91 73 96 / 10 10 20 10 -
DEL RIO INTL AIRPORT 97 76 92 75 94 / - - 30 20 10
GEORGETOWN MUNI AIRPORT 95 74 93 72 98 / 20 10 20 10 -
HONDO MUNI AIRPORT 96 74 90 73 96 / 20 10 30 20 -
SAN MARCOS MUNI AIRPORT 96 74 93 73 97 / 20 20 30 10 10
LA GRANGE - FAYETTE REGIONAL 94 76 92 75 99 / 40 20 30 10 20
SAN ANTONIO INTL AIRPORT 94 76 91 75 96 / 20 20 30 10 -
STINSON MUNI AIRPORT 95 74 92 73 94 / 20 20 30 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1006 AM CDT SUN JUL 7 2013
.UPDATE...
SCATTERED LIGHT SHOWERS TO COME ONSHORE THROUGH THE REMAINDER OF
THE MORNING...NO MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH
OF ACCUMULATION FROM MANY OF THESE QUICKLY NORTH-PASSING CELLS. AS
THE DAY HEATS UP INTO THE 90S...THIS 2 INCH PWAT AIR MASS OVER THE
COASTAL COUNTIES WILL CONTINUE TO CREEP FURTHER INLAND SO EXPECTING
PRECIPITATION TO BETTER FILL IN THROUGH THE EARLY EVENING. PROG
SOUNDINGS SHOW A NEAR-SATURATED COLUMN AS FAR NORTH AS THE CITY
BY TOMORROW MORNING. THUS...FEEL THAT AT LEAST HIGH END CHANCE
POPS ARE WARRANTED THROUGH TOMORROW AFTERNOON. WARM PROFILES MAKE
FOR SKINNY CAPES...LIMITED STORM COVERAGE. RELATIVELY LOWER AREAWIDE
(OVERALL) QPF DUE TO THE WIDELY-SCATTERED NATURE ON CONVECTION...
LOCALIZED POCKETS OF OVER AN INCH OVER THE SOUTHERN THIRD OF THE
CWA IS STILL NOT OUT OF THE QUESTION. 31
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT SUN JUL 7 2013/
AVIATION...
SCATTERED SHOWERS ARE ONGOING ACROSS THE COASTAL COUNTIES THIS
MORNING AS THE LEADING EDGE OF DEEP TROPICAL MOISTURE MOVES
INLAND. GREATEST CONCERN WITH THIS ISSUANCE REMAINS TIMING AND
COVERAGE OF PRECIPITATION TODAY. EXPECT SCATTERED SHOWERS WITH A
FEW ISOLATED THUNDERSTORMS MIXED IN ACROSS THE SOUTHERN HALF OF
THE REGION. WILL CARRY PROB30 MENTION FOR METRO AREA TAF SITES FOR
LATE AFTERNOON AS CONFIDENCE IN TIMING A BIT TOO LOW FOR TEMPO AT
THIS TIME. GREATEST IMPACTS WILL BE TO LBX AND GLS WITH DECREASING
COVERAGE TO THE NORTH. 38
PREV DISCUSSION... /ISSUED 425 AM CDT SUN JUL 7 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWS A LINE OF SHOWERS JUST REACHING THE
UPPER TX COAST THIS MORNING. THIS LINE OF SHOWERS APPEARS TO BE ON
THE LEADING EDGE OF HIGHER MOISTURE DELINEATED BY 2 INCH PRECIP
WATER VALUES NOTED ON GOES SOUNDER IMAGERY. UPPER LEVEL ANALYSIS
AND WATER VAPOR IMAGERY STILL SHOW A DEFORMING SHEAR AXIS WHICH
SEEMS TO BE IN THE PROCESS OF WEAKENING. PRESSURE GRADIENT AT THE
SFC HAS INCREASED SO GETTING SOME DECENT LOW LEVEL FLOW OFF THE
GULF WHICH SHOULD CONTINUE TO ADVECT HIGHER MOISTURE INLAND TODAY.
FOR THE MOST PART...GFS/ECMWF MODELS CONTINUE TO SHOW HIGHER
MOISTURE MOVE INTO SE TX THIS MORNING AND THROUGH THE EARLY
AFTERNOON. THE LATEST HRRR RUNS SEEMS TO SUPPORT THIS WITH
CONVECTION DEVELOPING INLAND MAINLY AROUND 15-16Z AND CONTINUING
THROUGH 22-23Z THIS AFTERNOON. ACTIVITY LOOKS MORE SCT IN NATURE
SO BACKED OFF ON POPS A TOUCH. STILL HAVE 60 POPS FOR THE I-10
CORRIDOR INCLUDING MOST OF HOUSTON. HEAVY RAINFALL THREAT WILL
LARGELY DEPEND ON INDIVIDUAL CELLS THAT BECOME STRONG AND FULLY
TAP DEEPER MOISTURE. GFS SHOWS PRECIP WATER VALUES GETTING TO
AROUND 2-2.2 INCHES WHICH WILL SUPPORT MODERATE TO HEAVY RAINFALL.
AGAIN MAIN FLOOD THREAT WILL BE URBAN IN NATURE WITH STORMS THAT
CAN QUICKLY PRODUCE 2 INCHES IN AN HOUR. OTHERWISE DRY GROUNDS
SHOULD BE ABLE TO ABSORB A LOT OF THE RUN OFF AND NOT CONTRIBUTE
TO FLOODING. WITH MOISTURE SLOWLY PUSHING INTO THE AREA...ALSO
INCREASED MAX TEMPS A COUPLE OF DEGREES AS CLOUD COVER WILL BE
SLOW TO FILL IN ACROSS THE AREA. LOOK FOR 1.8-2 INCH PW VALUES TO
REMAIN OVER SE TX THROUGH MONDAY SO WENT WITH 40/50 POPS FOR
SCATTERED ACTIVITY DURING THE DAY. AGAIN MOST OF THIS ACTIVITY
WILL BE DIURNALLY DRIVEN SO WILL HAVE LOWER POPS OVERNIGHT.
RAINFALL AMOUNTS AGAIN EXPECTED TO BE CONFINED TO THE COAST.
HOUSTON AREA MAY GET WIDE SPREAD HALF INCH AMOUNTS BUT THAT WILL
BE PUSHING IT. NORTH OF HOUSTON EXPECT RAINFALL AMOUNTS TO REALLY
DROP OFF AND AREAS FROM CONROE TO COLLEGE STATION MAY NOT SEE ANY
RAINFALL. BY AND LARGE THINK AREAS NORTH OF HOUSTON WILL AT MOST
GET 0.1-0.25 INCHES WITH 0.5-1 INCH AMOUNTS ALONG THE COAST. STILL
THINK HIGHEST MOISTURE WILL BE OFF TO THE EAST OVER LOUISIANA SO
RAINFALL AMOUNTS OF AN INCH OR MORE WILL BE IN THE GULF EASTWARD
THROUGH LOUISIANA. STILL DO NOT WANT TO RULE OUT A QUICK 2-3
INCHES IN SOME STRONGER CONVECTION BUT THINK THESE STORMS WILL BE
REALLY LOCALIZED AND NOT THE NORM.
IT LOOKS LIKE HIGHER MOISTURE OF 1.6-2 INCH PRECIP WATER VALUES
WILL LINGER TUE/WED SO WILL KEEP SOME 20/30 POPS IN THE FORECAST
FOR MAINLY AFTERNOON STORMS. MOISTURE DOES DECREASE THUR THROUGH
SAT SO HAVE POPS TAPERING OFF FROM 20 PERCENT TO NO RAIN CHANCES.
UPPER LEVEL PATTERN ALSO UNDERGOES SOME CHANGES DURING THIS TIME.
UPPER LEVEL RIDGE CURRENTLY OVER THE S ROCKIES REMAINS WEAK AND
NOT WELL ESTABLISHED FOR THE BEGINNING OF THE WEEK. BY THE END OF
THE WEEK THE RIDGE STRENGTHENS OVER THE C ROCKIES WITH ANOTHER
AMPLIFIED TROUGH OVER THE MID ATLANTIC BY FRIDAY. RIDGE WILL KEEP
LOWER THICKNESS HEIGHTS EAST OF THE AREA SO COULD SEE TEMPS
CREEPING UP TO UPPER 90S TO NEAR 100 FOR THE END OF THE WEEK.
TEMPS AT 850MB WHEN MIXED DOWN AT LEAST SUPPORT TEMPS IN THE UPPER
90S ACROSS THE AREA.
39
MARINE...
SCATTERED SHOWERS ARE MOVING THROUGH THE COASTAL WATERS THIS
MORNING ALONG THE LEADING EDGE OF DEEPER TROPICAL MOISTURE THAT
WILL CONTINUE TO PUSH INTO SOUTHEAST TEXAS TODAY. EXPECT SCATTERED
SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM THROUGH MONDAY
ACROSS THE COASTAL WATERS. LIGHT TO MODERATE SOUTHEASTERLY WINDS
WILL CONTINUE THROUGH THE NEXT SEVERAL DAYS. WITH THE EASTERLY
COMPONENT TO THE WINDS WE WILL CONTINUE TO SEE TIDE LEVELS AROUND
1 TO 1.5 FEET ABOVE NORMAL VALUES. RIP CURRENTS WILL ALSO REMAIN
PROBLEMATIC FOR AREA BEACHES THROUGH THE WEEKEND. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 96 76 95 76 98 / 30 20 30 20 10
HOUSTON (IAH) 92 77 94 77 96 / 60 30 50 20 20
GALVESTON (GLS) 89 82 90 82 92 / 50 50 50 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CDT THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...31
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
641 AM CDT SUN JUL 7 2013
.UPDATE...
SEE AVIATION FOR 12Z TAF DISCUSSION.
&&
.AVIATION...
A TROPICAL AIR MASS AND A MOSTLY ELEVATED LOW PRESSURE TROUGH
MOVING INTO THE TX COAST WILL DISRUPT THE OCCASIONAL MVFR CIG THIS
MORNING. WITH LIGHT WINDS AND BUOYANT AIR IN THE AREA...SCT LOW
BASED CUMULUS OF AROUND 1500 FT WILL HAVE TOPS LIFTING TO 10000 FT
OR HIGHER AS LIGHT SHOWERS BEGIN TO MOVE TOWARD THE I-35
TERMINALS. WILL LEAVE OUT MENTION OF MVFR CIGS UNTIL THE BETTER
CHANCE OF RAINS ARRIVE IN THE EARLY AFTERNOON HOURS AS DEPICTED BY
THE HRRR SIMULATED REFLECTIVITY. ANY FEEBLE ATTEMPT TO DEVELOP A
SURFACE CIRCULATION EAST OF BRO SHOULD BE HELD IN CHECK AS THE
UPPER SUPPORT PUSHES ONSHORE BY TONIGHT. THUS WILL PLAN ON A MORE
STEADY ONSHORE WIND BY TONIGHT...AND A MORE ROUTINE FORMATION OF
LOW CLOUDS AT AROUND 09Z. HIGH PWAT VALUES COULD SUPPORT
ADDITIONAL SHOWERS AROUND DAYBREAK...BUT WILL LEAVE OUT OF THE
LATE PERIODS OF THE TAFS UNTIL A BETTER TREND CAN BE ESTABLISHED.
&&
.PREV DISCUSSION... /ISSUED 322 AM CDT SUN JUL 7 2013/
SHORT TERM (TODAY THROUGH MONDAY)...
A WEAKENED UPPER LEVEL INVERTED TROUGH FEATURE OVER THE WESTERN GULF
OF MEXICO WILL MIGRATE WEST ONTO THE TEXAS COASTAL PLAINS REGION
TODAY WITH AN ENHANCEMENT OF SEA BREEZE ACTIVITY LIKELY OVER
SOUTHERN AND EASTERN PORTIONS OF THE CWA. HIGH TEMPERATURES TODAY
WILL LOWER SLIGHTLY WITH THE INCREASING SURFACE BASED MOISTURE.
HIGHS TODAY WILL RANGE FROM THE LOW 90S ACROSS PORTIONS OF THE HILL
COUNTRY TO THE MID TO UPPER 90S ELSEWHERE. INCREASING CLOUDINESS
TONIGHT WITH A SLIGHT CHANCE OF MOSTLY EARLY EVENING SHOWERS AND
STORMS SOUTH AND EAST. LOWS IN THE 70S. THE UPPER TROUGH WILL MOVE
ACROSS THE AREA MONDAY WITH DEEP...MOIST TROPICAL EASTERLIES
BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGHOUT MUCH OF
THE AREA. HIGHS MONDAY WILL MODERATE BACK INTO THE LOWER 90S MOST
LOCATIONS WITH NEAR 90 HILL COUNTRY.
LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
SHOWERS AND STORMS WILL DIMINISH MONDAY EVENING AS THE INVERTED
UPPER TROUGH PUSHES DEEPER INTO MEXICO. LOWS MONDAY NIGHT AGAIN
MOSTLY IN THE 70S WITH NEAR 70 HILLS. UPPER LEVEL RIDGING WILL BUILD
BACK OVER THE REGION TUESDAY AND REMAIN STRONG THROUGH SATURDAY AS
THE CENTER OF THE HIGH SHIFTS EAST INTO THE SOUTHERN PLAINS BY LATE
IN THE WEEK. CONTINUED DEEP EASTERLIES HOWEVER IN THE MID AND LOWER
LEVELS OF THE ATMOSPHERE WILL ENHANCE SOME SEA BREEZE CONVECTION
INTO EASTERN SECTIONS BOTH TUESDAY AND WEDNESDAY. MORNING LOW CLOUDS
WILL BECOME PARTLY CLOUDY AFTERNOONS BOTH DAYS WITH HIGHS RANGING
FROM THE LOW 90S HILLS TO THE UPPER 90S TO NEAR 100 EASTERN SECTIONS.
LOWS IN THE 70S. ANOTHER EASTERLY WAVE FEATURE PUSHING ACROSS THE
COASTAL PLAINS THURSDAY WILL GENERATE MORE ACTIVITY OVER EASTERN
SECTIONS BOTH THURSDAY AND FRIDAY. HIGHS WILL CONTINUE NEAR OR
SLIGHTLY ABOVE SEASONAL NORMS THURSDAY THROUGH SATURDAY. LOWS
GENERALLY IN THE 70S EXCEPT UPPER 60S TO NEAR 70 HILLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 97 75 94 74 100 / 10 20 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 97 74 93 72 99 / 10 20 30 10 -
NEW BRAUNFELS MUNI AIRPORT 95 73 93 72 96 / 10 20 30 10 10
BURNET MUNI AIRPORT 95 74 91 73 96 / - 10 20 10 -
DEL RIO INTL AIRPORT 96 76 92 75 94 / - - 30 20 10
GEORGETOWN MUNI AIRPORT 95 74 93 72 98 / 10 10 20 10 -
HONDO MUNI AIRPORT 95 74 90 73 96 / - 10 30 20 -
SAN MARCOS MUNI AIRPORT 96 74 93 73 97 / 10 20 30 10 10
LA GRANGE - FAYETTE REGIONAL 95 76 92 75 99 / 40 20 30 10 20
SAN ANTONIO INTL AIRPORT 95 76 91 75 96 / 10 20 30 10 -
STINSON MUNI AIRPORT 95 74 92 73 94 / 10 20 30 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...02
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
628 AM CDT SUN JUL 7 2013
.AVIATION...
WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE DRIFTING
ACROSS THE SOUTH PLAINS EARLY THIS MORNING. ODDS OF A DIRECT
IMPACT AT KLBB ARE LOW BUT NOT ZERO AND GIVEN THAT A SMALL STORM
RECENTLY DEVELOPED ABOUT 12 MILES WEST OF THE TERMINAL HAVE
DECIDED TO INSERT A VCTS MENTION AT KLBB IN THE SHORT TERM.
OUTSIDE OF ANY STORMS...EXPECT VFR CONDITIONS TO PREVAIL WITH
SOUTHERLY WINDS...THOUGH AT WEAKER LEVELS THAN THE PAST TWO
AFTERNOONS. AFTERNOON CONVECTION SHOULD REMAIN WELL WEST OF THE
TERMINALS IN NEW MEXICO.
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT SUN JUL 7 2013/
SHORT TERM...
DIRTY SOUTHWESTERN RIDGE HAS EXPANDED TO ENCOMPASS WEST TEXAS AND
THIS WILL PROVIDE ANOTHER TOASTY JULY DAY WITH HIGHS SIMILAR TO
SATURDAY. MID-LEVEL MOISTURE SPILLING OVER THE SOUTH PLAINS COUPLED
WITH WEAK ELEVATED INSTABILITY...DEEP LAYER MOISTURE CONVERGENCE AND
ELEVATED FRONTOGENESIS WERE SUPPORTING A FEW RECENTLY DEVELOPED
SHOWERS AND STORMS ACROSS THE FAR NORTHWESTERN ZONES. THIS ACTIVITY
WAS NOT MOVING MUCH THANKS TO WEAK STEERING FLOW/WINDS WITHIN THE
RIDGE...BUT WE COULD SEE AT LEAST ISOLATED ACTIVITY HANG ON ACROSS
THE WESTERN ZONES AND PERHAPS EXPAND/DEVELOP TOWARD THE I-27/US-87
CORRIDOR AS THE RECENT RAP AND HRRR RUNS SUGGEST. HENCE HAVE
INSERTED A SLIGHT CHANCE OF THUNDERSTORMS INTO THE GRIDS ACROSS THE
WESTERN AND INTO THE CENTRAL ZONES IN THE 12-18Z TIME-FRAME. ANY
ACTIVITY WILL LIKELY WANE TOWARD MID TO LATE MORNING. STRONG HEATING
AND SUFFICIENT MOISTURE WILL THEN YIELD ANOTHER ROUND OF CONVECTION
OVER THE HIGHER TERRAIN OF NM AND CO THIS AFTERNOON...BUT SIMILAR TO
SATURDAY...THIS ACTIVITY WILL NOT HAVE MUCH INCENTIVE TO MOVE VERY
FAR EASTWARD AND SHOULD STAY WELL WEST OF THE CWA. THE MID-LEVEL
MOISTURE PLUME WILL STILL EXTEND IN CLOSE PROXIMITY TO THE FAR
NORTHWESTERN ZONES LATE TONIGHT AND THERE MAY BE SOME RISK OF LATE
NIGHT ELEVATED CONVECTIVE DEVELOPMENT LIKE WE HAVE SEEN THE LAST
COUPLE OF NIGHTS. HOWEVER THE MID-LEVEL MOISTURE PLUME IS PROGGED TO
THIN/DRY A BIT LOCALLY AND LOW-LEVEL FORCING APPEARS LESS...SO HAVE
KEPT THE FORECAST DRY FOR TONIGHT. OTHERWISE...IT WILL BE ANOTHER
MILD NIGHT WITH LOWS VARYING FROM THE MID-60S NORTHWEST TO LOWER AND
MIDDLE 70S EAST.
LONG TERM...
AN UPPER LEVEL RIDGE...CENTERED ROUGHLY OVER THE 4-CORNERS INITIALLY...
AND GRADUALLY MIGRATING INTO THE CENTRAL HIGH PLAINS...WILL KEEP
THE FA HOT AND DRY FOR THE MOST PART THIS UPCOMING WEEK.
OROGRAPHICALLY FORCED CONVECTION WITHIN MOISTURE PLUME TRAPPED IN
THE RIDGE SHOULD REMAIN TO OUR WEST MONDAY WHILE AN INVERTED
TROUGH MOVING WEST ACROSS THE BIG BEND WILL BE OF LITTLE
CONSEQUENCE TO OUR WX. WE ARE STILL WATCHING FOR A TEMPORARY
WEAKNESS TO DEVELOP IN THE EASTERN PART OF THE RIDGE WED/THU AS A
SHORTWAVE MOVES FROM THE CANADIAN PRAIRIES TO THE GREAT LAKES AND
A COLD FRONT DIPS INTO SRN CO/SW KS. BUT ANY TSTM ACTIVITY
ASSOCIATED WITH THIS WAVE/FRONT APPEARS UNLIKELY TO MAKE IT INTO
OUR NRN ZONES LATE WED/EARLY THU. THEN...AS THE UPPER RIDGE RE-
EXPANDS E-NEWD WE EXPECT TEMPS TO NUDGE UPWARD A FEW DEGREES
HEADING INTO NEXT WEEKEND. EARLY NEXT WEEK...THE UPPER RIDGE MAY
START TO RETROGRADE BACK TO THE WEST AS AN UPPER TROUGH/LOW
DEVELOPS IN THE DEEP SOUTH. WE ARE COUNTING ON THIS PATTERN CHANGE
TO BRING A COOLING TREND AND PERHAPS A CHANCE OF RAIN NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 92 66 93 66 95 / 20 10 10 10 10
TULIA 94 67 95 68 96 / 20 10 10 10 10
PLAINVIEW 93 67 95 69 95 / 20 10 10 10 10
LEVELLAND 94 68 94 70 94 / 20 10 10 10 10
LUBBOCK 95 70 95 70 95 / 20 10 10 10 10
DENVER CITY 94 68 93 69 93 / 20 10 10 10 10
BROWNFIELD 95 69 94 70 95 / 20 10 10 10 0
CHILDRESS 99 71 98 74 99 / 0 0 0 0 0
SPUR 97 71 96 72 97 / 0 0 0 0 0
ASPERMONT 98 72 97 74 99 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/33/23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
624 AM CDT SUN JUL 7 2013
.DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION
&&
.AVIATION...
SCATTERED SHOWERS ARE ONGOING ACROSS THE COASTAL COUNTIES THIS
MORNING AS THE LEADING EDGE OF DEEP TROPICAL MOISTURE MOVES
INLAND. GREATEST CONCERN WITH THIS ISSUANCE REMAINS TIMING AND
COVERAGE OF PRECIPITATION TODAY. EXPECT SCATTERED SHOWERS WITH A
FEW ISOLATED THUNDERSTORMS MIXED IN ACROSS THE SOUTHERN HALF OF
THE REGION. WILL CARRY PROB30 MENTION FOR METRO AREA TAF SITES FOR
LATE AFTERNOON AS CONFIDENCE IN TIMING A BIT TOO LOW FOR TEMPO AT
THIS TIME. GREATEST IMPACTS WILL BE TO LBX AND GLS WITH DECREASING
COVERAGE TO THE NORTH. 38
&&
.PREV DISCUSSION... /ISSUED 425 AM CDT SUN JUL 7 2013/
DISCUSSION...
LATEST RADAR IMAGERY SHOWS A LINE OF SHOWERS JUST REACHING THE
UPPER TX COAST THIS MORNING. THIS LINE OF SHOWERS APPEARS TO BE ON
THE LEADING EDGE OF HIGHER MOISTURE DELINEATED BY 2 INCH PRECIP
WATER VALUES NOTED ON GOES SOUNDER IMAGERY. UPPER LEVEL ANALYSIS
AND WATER VAPOR IMAGERY STILL SHOW A DEFORMING SHEAR AXIS WHICH
SEEMS TO BE IN THE PROCESS OF WEAKENING. PRESSURE GRADIENT AT THE
SFC HAS INCREASED SO GETTING SOME DECENT LOW LEVEL FLOW OFF THE
GULF WHICH SHOULD CONTINUE TO ADVECT HIGHER MOISTURE INLAND TODAY.
FOR THE MOST PART...GFS/ECMWF MODELS CONTINUE TO SHOW HIGHER
MOISTURE MOVE INTO SE TX THIS MORNING AND THROUGH THE EARLY
AFTERNOON. THE LATEST HRRR RUNS SEEMS TO SUPPORT THIS WITH
CONVECTION DEVELOPING INLAND MAINLY AROUND 15-16Z AND CONTINUING
THROUGH 22-23Z THIS AFTERNOON. ACTIVITY LOOKS MORE SCT IN NATURE
SO BACKED OFF ON POPS A TOUCH. STILL HAVE 60 POPS FOR THE I-10
CORRIDOR INCLUDING MOST OF HOUSTON. HEAVY RAINFALL THREAT WILL
LARGELY DEPEND ON INDIVIDUAL CELLS THAT BECOME STRONG AND FULLY
TAP DEEPER MOISTURE. GFS SHOWS PRECIP WATER VALUES GETTING TO
AROUND 2-2.2 INCHES WHICH WILL SUPPORT MODERATE TO HEAVY RAINFALL.
AGAIN MAIN FLOOD THREAT WILL BE URBAN IN NATURE WITH STORMS THAT
CAN QUICKLY PRODUCE 2 INCHES IN AN HOUR. OTHERWISE DRY GROUNDS
SHOULD BE ABLE TO ABSORB A LOT OF THE RUN OFF AND NOT CONTRIBUTE
TO FLOODING. WITH MOISTURE SLOWLY PUSHING INTO THE AREA...ALSO
INCREASED MAX TEMPS A COUPLE OF DEGREES AS CLOUD COVER WILL BE
SLOW TO FILL IN ACROSS THE AREA. LOOK FOR 1.8-2 INCH PW VALUES TO
REMAIN OVER SE TX THROUGH MONDAY SO WENT WITH 40/50 POPS FOR
SCATTERED ACTIVITY DURING THE DAY. AGAIN MOST OF THIS ACTIVITY
WILL BE DIURNALLY DRIVEN SO WILL HAVE LOWER POPS OVERNIGHT.
RAINFALL AMOUNTS AGAIN EXPECTED TO BE CONFINED TO THE COAST.
HOUSTON AREA MAY GET WIDE SPREAD HALF INCH AMOUNTS BUT THAT WILL
BE PUSHING IT. NORTH OF HOUSTON EXPECT RAINFALL AMOUNTS TO REALLY
DROP OFF AND AREAS FROM CONROE TO COLLEGE STATION MAY NOT SEE ANY
RAINFALL. BY AND LARGE THINK AREAS NORTH OF HOUSTON WILL AT MOST
GET 0.1-0.25 INCHES WITH 0.5-1 INCH AMOUNTS ALONG THE COAST. STILL
THINK HIGHEST MOISTURE WILL BE OFF TO THE EAST OVER LOUISIANA SO
RAINFALL AMOUNTS OF AN INCH OR MORE WILL BE IN THE GULF EASTWARD
THROUGH LOUISIANA. STILL DO NOT WANT TO RULE OUT A QUICK 2-3
INCHES IN SOME STRONGER CONVECTION BUT THINK THESE STORMS WILL BE
REALLY LOCALIZED AND NOT THE NORM.
IT LOOKS LIKE HIGHER MOISTURE OF 1.6-2 INCH PRECIP WATER VALUES
WILL LINGER TUE/WED SO WILL KEEP SOME 20/30 POPS IN THE FORECAST
FOR MAINLY AFTERNOON STORMS. MOISTURE DOES DECREASE THUR THROUGH
SAT SO HAVE POPS TAPERING OFF FROM 20 PERCENT TO NO RAIN CHANCES.
UPPER LEVEL PATTERN ALSO UNDERGOES SOME CHANGES DURING THIS TIME.
UPPER LEVEL RIDGE CURRENTLY OVER THE S ROCKIES REMAINS WEAK AND
NOT WELL ESTABLISHED FOR THE BEGINNING OF THE WEEK. BY THE END OF
THE WEEK THE RIDGE STRENGTHENS OVER THE C ROCKIES WITH ANOTHER
AMPLIFIED TROUGH OVER THE MID ATLANTIC BY FRIDAY. RIDGE WILL KEEP
LOWER THICKNESS HEIGHTS EAST OF THE AREA SO COULD SEE TEMPS
CREEPING UP TO UPPER 90S TO NEAR 100 FOR THE END OF THE WEEK.
TEMPS AT 850MB WHEN MIXED DOWN AT LEAST SUPPORT TEMPS IN THE UPPER
90S ACROSS THE AREA.
39
MARINE...
SCATTERED SHOWERS ARE MOVING THROUGH THE COASTAL WATERS THIS
MORNING ALONG THE LEADING EDGE OF DEEPER TROPICAL MOISTURE THAT
WILL CONTINUE TO PUSH INTO SOUTHEAST TEXAS TODAY. EXPECT SCATTERED
SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM THROUGH MONDAY
ACROSS THE COASTAL WATERS. LIGHT TO MODERATE SOUTHEASTERLY WINDS
WILL CONTINUE THROUGH THE NEXT SEVERAL DAYS. WITH THE EASTERLY
COMPONENT TO THE WINDS WE WILL CONTINUE TO SEE TIDE LEVELS AROUND
1 TO 1.5 FEET ABOVE NORMAL VALUES. RIP CURRENTS WILL ALSO REMAIN
PROBLEMATIC FOR AREA BEACHES THROUGH THE WEEKEND. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 96 75 95 75 97 / 30 20 30 20 10
HOUSTON (IAH) 93 76 94 76 96 / 60 30 50 20 20
GALVESTON (GLS) 88 80 90 81 90 / 50 50 50 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
425 AM CDT SUN JUL 7 2013
.DISCUSSION...
LATEST RADAR IMAGERY SHOWS A LINE OF SHOWERS JUST REACHING THE
UPPER TX COAST THIS MORNING. THIS LINE OF SHOWERS APPEARS TO BE ON
THE LEADING EDGE OF HIGHER MOISTURE DELINEATED BY 2 INCH PRECIP
WATER VALUES NOTED ON GOES SOUNDER IMAGERY. UPPER LEVEL ANALYSIS
AND WATER VAPOR IMAGERY STILL SHOW A DEFORMING SHEAR AXIS WHICH
SEEMS TO BE IN THE PROCESS OF WEAKENING. PRESSURE GRADIENT AT THE
SFC HAS INCREASED SO GETTING SOME DECENT LOW LEVEL FLOW OFF THE
GULF WHICH SHOULD CONTINUE TO ADVECT HIGHER MOISTURE INLAND TODAY.
FOR THE MOST PART...GFS/ECMWF MODELS CONTINUE TO SHOW HIGHER
MOISTURE MOVE INTO SE TX THIS MORNING AND THROUGH THE EARLY
AFTERNOON. THE LATEST HRRR RUNS SEEMS TO SUPPORT THIS WITH
CONVECTION DEVELOPING INLAND MAINLY AROUND 15-16Z AND CONTINUING
THROUGH 22-23Z THIS AFTERNOON. ACTIVITY LOOKS MORE SCT IN NATURE
SO BACKED OFF ON POPS A TOUCH. STILL HAVE 60 POPS FOR THE I-10
CORRIDOR INCLUDING MOST OF HOUSTON. HEAVY RAINFALL THREAT WILL
LARGELY DEPEND ON INDIVIDUAL CELLS THAT BECOME STRONG AND FULLY
TAP DEEPER MOISTURE. GFS SHOWS PRECIP WATER VALUES GETTING TO
AROUND 2-2.2 INCHES WHICH WILL SUPPORT MODERATE TO HEAVY RAINFALL.
AGAIN MAIN FLOOD THREAT WILL BE URBAN IN NATURE WITH STORMS THAT
CAN QUICKLY PRODUCE 2 INCHES IN AN HOUR. OTHERWISE DRY GROUNDS
SHOULD BE ABLE TO ABSORB A LOT OF THE RUN OFF AND NOT CONTRIBUTE
TO FLOODING. WITH MOISTURE SLOWLY PUSHING INTO THE AREA...ALSO
INCREASED MAX TEMPS A COUPLE OF DEGREES AS CLOUD COVER WILL BE
SLOW TO FILL IN ACROSS THE AREA. LOOK FOR 1.8-2 INCH PW VALUES TO
REMAIN OVER SE TX THROUGH MONDAY SO WENT WITH 40/50 POPS FOR
SCATTERED ACTIVITY DURING THE DAY. AGAIN MOST OF THIS ACTIVITY
WILL BE DIURNALLY DRIVEN SO WILL HAVE LOWER POPS OVERNIGHT.
RAINFALL AMOUNTS AGAIN EXPECTED TO BE CONFINED TO THE COAST.
HOUSTON AREA MAY GET WIDE SPREAD HALF INCH AMOUNTS BUT THAT WILL
BE PUSHING IT. NORTH OF HOUSTON EXPECT RAINFALL AMOUNTS TO REALLY
DROP OFF AND AREAS FROM CONROE TO COLLEGE STATION MAY NOT SEE ANY
RAINFALL. BY AND LARGE THINK AREAS NORTH OF HOUSTON WILL AT MOST
GET 0.1-0.25 INCHES WITH 0.5-1 INCH AMOUNTS ALONG THE COAST. STILL
THINK HIGHEST MOISTURE WILL BE OFF TO THE EAST OVER LOUISIANA SO
RAINFALL AMOUNTS OF AN INCH OR MORE WILL BE IN THE GULF EASTWARD
THROUGH LOUISIANA. STILL DO NOT WANT TO RULE OUT A QUICK 2-3
INCHES IN SOME STRONGER CONVECTION BUT THINK THESE STORMS WILL BE
REALLY LOCALIZED AND NOT THE NORM.
IT LOOKS LIKE HIGHER MOISTURE OF 1.6-2 INCH PRECIP WATER VALUES
WILL LINGER TUE/WED SO WILL KEEP SOME 20/30 POPS IN THE FORECAST
FOR MAINLY AFTERNOON STORMS. MOISTURE DOES DECREASE THUR THROUGH
SAT SO HAVE POPS TAPERING OFF FROM 20 PERCENT TO NO RAIN CHANCES.
UPPER LEVEL PATTERN ALSO UNDERGOES SOME CHANGES DURING THIS TIME.
UPPER LEVEL RIDGE CURRENTLY OVER THE S ROCKIES REMAINS WEAK AND
NOT WELL ESTABLISHED FOR THE BEGINNING OF THE WEEK. BY THE END OF
THE WEEK THE RIDGE STRENGTHENS OVER THE C ROCKIES WITH ANOTHER
AMPLIFIED TROUGH OVER THE MID ATLANTIC BY FRIDAY. RIDGE WILL KEEP
LOWER THICKNESS HEIGHTS EAST OF THE AREA SO COULD SEE TEMPS
CREEPING UP TO UPPER 90S TO NEAR 100 FOR THE END OF THE WEEK.
TEMPS AT 850MB WHEN MIXED DOWN AT LEAST SUPPORT TEMPS IN THE UPPER
90S ACROSS THE AREA.
39
&&
.MARINE...
SCATTERED SHOWERS ARE MOVING THROUGH THE COASTAL WATERS THIS
MORNING ALONG THE LEADING EDGE OF DEEPER TROPICAL MOISTURE THAT
WILL CONTINUE TO PUSH INTO SOUTHEAST TEXAS TODAY. EXPECT SCATTERED
SHOWERS WITH PERHAPS AN ISOLATED THUNDERSTORM THROUGH MONDAY
ACROSS THE COASTAL WATERS. LIGHT TO MODERATE SOUTHEASTERLY WINDS
WILL CONTINUE THROUGH THE NEXT SEVERAL DAYS. WITH THE EASTERLY
COMPONENT TO THE WINDS WE WILL CONTINUE TO SEE TIDE LEVELS AROUND
1 TO 1.5 FEET ABOVE NORMAL VALUES. RIP CURRENTS WILL ALSO REMAIN
PROBLEMATIC FOR AREA BEACHES THROUGH THE WEEKEND. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 96 75 95 75 97 / 30 20 30 20 10
HOUSTON (IAH) 93 76 94 76 96 / 60 30 50 20 20
GALVESTON (GLS) 88 80 90 81 90 / 50 50 50 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
343 AM CDT SUN JUL 7 2013
.SHORT TERM...
DIRTY SOUTHWESTERN RIDGE HAS EXPANDED TO ENCOMPASS WEST TEXAS AND
THIS WILL PROVIDE ANOTHER TOASTY JULY DAY WITH HIGHS SIMILAR TO
SATURDAY. MID-LEVEL MOISTURE SPILLING OVER THE SOUTH PLAINS COUPLED
WITH WEAK ELEVATED INSTABILITY...DEEP LAYER MOISTURE CONVERGENCE AND
ELEVATED FRONTOGENESIS WERE SUPPORTING A FEW RECENTLY DEVELOPED
SHOWERS AND STORMS ACROSS THE FAR NORTHWESTERN ZONES. THIS ACTIVITY
WAS NOT MOVING MUCH THANKS TO WEAK STEERING FLOW/WINDS WITHIN THE
RIDGE...BUT WE COULD SEE AT LEAST ISOLATED ACTIVITY HANG ON ACROSS
THE WESTERN ZONES AND PERHAPS EXPAND/DEVELOP TOWARD THE I-27/US-87
CORRIDOR AS THE RECENT RAP AND HRRR RUNS SUGGEST. HENCE HAVE
INSERTED A SLIGHT CHANCE OF THUNDERSTORMS INTO THE GRIDS ACROSS THE
WESTERN AND INTO THE CENTRAL ZONES IN THE 12-18Z TIME-FRAME. ANY
ACTIVITY WILL LIKELY WANE TOWARD MID TO LATE MORNING. STRONG HEATING
AND SUFFICIENT MOISTURE WILL THEN YIELD ANOTHER ROUND OF CONVECTION
OVER THE HIGHER TERRAIN OF NM AND CO THIS AFTERNOON...BUT SIMILAR TO
SATURDAY...THIS ACTIVITY WILL NOT HAVE MUCH INCENTIVE TO MOVE VERY
FAR EASTWARD AND SHOULD STAY WELL WEST OF THE CWA. THE MID-LEVEL
MOISTURE PLUME WILL STILL EXTEND IN CLOSE PROXIMITY TO THE FAR
NORTHWESTERN ZONES LATE TONIGHT AND THERE MAY BE SOME RISK OF LATE
NIGHT ELEVATED CONVECTIVE DEVELOPMENT LIKE WE HAVE SEEN THE LAST
COUPLE OF NIGHTS. HOWEVER THE MID-LEVEL MOISTURE PLUME IS PROGGED TO
THIN/DRY A BIT LOCALLY AND LOW-LEVEL FORCING APPEARS LESS...SO HAVE
KEPT THE FORECAST DRY FOR TONIGHT. OTHERWISE...IT WILL BE ANOTHER
MILD NIGHT WITH LOWS VARYING FROM THE MID-60S NORTHWEST TO LOWER AND
MIDDLE 70S EAST.
&&
.LONG TERM...
AN UPPER LEVEL RIDGE...CENTERED ROUGHLY OVER THE 4-CORNERS INITIALLY...
AND GRADUALLY MIGRATING INTO THE CENTRAL HIGH PLAINS...WILL KEEP
THE FA HOT AND DRY FOR THE MOST PART THIS UPCOMING WEEK.
OROGRAPHICALLY FORCED CONVECTION WITHIN MOISTURE PLUME TRAPPED IN
THE RIDGE SHOULD REMAIN TO OUR WEST MONDAY WHILE AN INVERTED
TROUGH MOVING WEST ACROSS THE BIG BEND WILL BE OF LITTLE
CONSEQUENCE TO OUR WX. WE ARE STILL WATCHING FOR A TEMPORARY
WEAKNESS TO DEVELOP IN THE EASTERN PART OF THE RIDGE WED/THU AS A
SHORTWAVE MOVES FROM THE CANADIAN PRAIRIES TO THE GREAT LAKES AND
A COLD FRONT DIPS INTO SRN CO/SW KS. BUT ANY TSTM ACTIVITY
ASSOCIATED WITH THIS WAVE/FRONT APPEARS UNLIKELY TO MAKE IT INTO
OUR NRN ZONES LATE WED/EARLY THU. THEN...AS THE UPPER RIDGE RE-
EXPANDS E-NEWD WE EXPECT TEMPS TO NUDGE UPWARD A FEW DEGREES
HEADING INTO NEXT WEEKEND. EARLY NEXT WEEK...THE UPPER RIDGE MAY
START TO RETROGRADE BACK TO THE WEST AS AN UPPER TROUGH/LOW
DEVELOPS IN THE DEEP SOUTH. WE ARE COUNTING ON THIS PATTERN CHANGE
TO BRING A COOLING TREND AND PERHAPS A CHANCE OF RAIN NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 92 66 93 66 95 / 20 10 10 10 10
TULIA 94 67 95 68 96 / 20 10 10 10 10
PLAINVIEW 93 67 95 69 95 / 20 10 10 10 10
LEVELLAND 94 68 94 70 94 / 20 10 10 10 10
LUBBOCK 95 70 95 70 95 / 20 10 10 10 10
DENVER CITY 94 68 93 69 93 / 20 10 10 10 10
BROWNFIELD 95 69 94 70 95 / 20 10 10 10 0
CHILDRESS 99 71 98 74 99 / 0 0 0 0 0
SPUR 97 71 96 72 97 / 0 0 0 0 0
ASPERMONT 98 72 97 74 99 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/33
AREA FORECAST DISCUSSION
NWS SPOKANE WA
446 PM PDT Mon Jul 8 2013
.SYNOPSIS...
A weather system passing through the Inland Northwest today will
promote scattered showers and thunderstorms across the northern
mountains of Washington and Idaho, as well as southeast
Washington. Tuesday and Wednesday will be the warmest days this
week with high temperatures in the upper 80s to mid 90s. Thursday
through Saturday will be occasionally breezy with temperatures
pretty close to average, or slightly below. Low shower and
thunderstorms chances will linger near the mountains, especially
closer to the Canadian border, but otherwise conditions will be
dry. Temperatures begin to warm up again slightly going into early
next week.
&&
.DISCUSSION...
This Afternoon and Evening: The weather over northeast Washington
and the Idaho Panhandle will be active. Scattered thunderstorms
are expected through early this evening. Our concern area extends
from the Okanogan Highlands through northeast Washington into the
northern and central Idaho Panhandle. The 2 PM visible imagery
shows a mid-level atmospheric circulation in far southeast British
Columbia slowly moving east. Around this circulation the
atmosphere has become increasingly unstable with the RUC analysis
indicating 500 to 1000 J/KG of surface based CAPE from Republic to
Sandpoint to Spokane to Kellogg. Very little convective inhibition
remains, so look for convection to continue to develop through
late afternoon. Shear and buoyancy values suggest the potential
for organized multi-cell thunderstorms. Our main threat through 6
PM will be the potential for hail, heavy rain, and gusty winds. A
couple severe thunderstorm warnings may be needed, but most of the
cells through early evening will probably pulse up, produce hail
up to dime size, then pulse down. The threat for thunderstorms
should dissipate quickly early this evening as the upper level
support (upper low in SE BC) moves east of the region focusing the
threat over Montana.
Tuesday: A shortwave ridge of high pressure will replace the
trough over the Inland Northwest for Tuesday. Look for relatively
light winds, clear skies and temperatures 5 to 8 degrees above
average. /GKoch
Tuesday night through Thursday evening...General long-wave trof
lingers overhead but the air-mass contained in it is not very
unstable and does not have much moisture tied to any discrete
feature traversing through it. As thus for the most part a dry
forecast remains, with exception being minimal chance for
afternoon/evening mountain thunderstorms up North and over the
Idaho Panhandle Thursday afternoon and evening. Forecast
temperatures remain just slightly on the warm side of what would
be considered normal for this time of year. Other shortwave
features of note will be a dry disturbance passage on Wednesday
afternoon and evening which will increase the wind some but only
to low breezy category at most. /Pelatti
Thursday night through Monday: The Inland Northwest remains in a
more active pattern through the week`s end, before high pressure
starts to nudge in Sunday and Monday. A shortwave system continues
to slip through Idaho into Montana Thursday night, even as a
second shortwave begins to move toward the Cascades. That second
shortwave slips across eastern Washington and north Idaho through
Friday, with a third wave slipping by Saturday before high
pressure begins to nudge in Saturday night. Models continue to
disagree over some of the details. Yet the progression of these
features will bring some shower and thunderstorm chances to the
region. The main chances remain around the northern mountains.
Smaller chances will be found across the Blue Mountains through
the Central Panhandle, including the Palouse as the wave is
exiting Thursday night. While some of these waves are depicted as
being somewhat dynamic/strong, models still do not depict
significant instability and keep the deeper moisture southeast of
the region. So regardless of timing and track, fuel for showers is
not impressive. Thus over PoPs remain slight or isolated in
nature. Look for occasional breezy conditions, especially Friday,
with the passage of these waves. Although a couple models skim
another wave by southern BC, near the WA/ID border early next
week, drier conditions are forecast going into Sunday and Monday.
Look for slightly cooler than normal conditions around the end of
the work week, before temperatures warm closer to or slightly
above seasonal norms going into early next week. /J. Cote`
&&
.AVIATION...
00Z TAFS: Showers and thunderstorms will be the main aviation impact
through 02z. The window of opportunity for thunderstorms is
decreasing as the upper trough is shifting into western Montana.
Hail up to dime size, gusts to 30 mph and very brief heavy rain
look to be the upper end of what we can expect with the strongest
cells. Aft 02z expect periods of think high clouds moving through
otherwise SKC and light winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 89 60 89 59 83 / 0 0 0 0 0 10
Coeur d`Alene 56 87 58 87 58 83 / 10 0 0 0 0 10
Pullman 53 87 55 88 55 82 / 0 0 0 10 10 10
Lewiston 62 95 64 95 63 90 / 0 0 0 10 10 10
Colville 53 90 56 92 56 86 / 10 0 0 0 0 10
Sandpoint 50 85 53 86 54 82 / 20 0 0 0 0 10
Kellogg 54 87 57 87 58 82 / 10 0 0 0 10 10
Moses Lake 60 94 62 94 60 87 / 0 0 0 0 0 0
Wenatchee 64 92 65 91 62 85 / 0 0 0 0 0 0
Omak 60 94 60 92 59 86 / 0 0 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1043 AM PDT Sun Jul 7 2013
.SYNOPSIS...
There will be a chance for thunderstorms over the North Cascades
this afternoon with the remainder of the region generally warm and
dry. The threat for showers and thunderstorms will migrate east
overnight into portions of Eastern WA and into the Idaho Panhandle
on Monday. Tuesday and Wednesday should be the warmest days of the
week with continued dry conditions. Wednesday will be locally
breezy...especially in and near the Cascades with the arrival of a
cold front late. The front could knock temperatures back close to
normal for Thursday, Friday, and Saturday.
&&
.DISCUSSION...
Surface-based cumulus are starting to develop over the ridges of
the north Cascades. Still too shallow to see anything on radar.
15Z HRRR still shows stronger convection developing in the next
few hours, which is in line with the current forecast.
As the short wave responsible for this convection tracks eastward
across our area, the showers/thunderstorms will move across the
northern mountain areas overnight. Could see a stray shower over
the Basin north of Highway 2, including the Spokane/CdA metro area.
Meanwhile another area of thunderstorms will develop tonight after
midnight over southeast WA and the southern Panhandle. This
activity will stay south of the I-90 corridor overnight and into
Monday morning. RJ
&&
.AVIATION...
18Z TAFS: Thunderstorms are expected to develop over the Cascades
this afternoon and may affect the KEAT TAF site around 00Z today.
These showers/thunderstorms will track across the northern
mountains overnight and into the northern Panhandle. There is a
very low probability that they may bring a light shower to the
KGEG/KSFF/KCOE TAF sites late tonight, but the probability was too
low to include in the TAF. Meanwhile to the south thunderstorms
may develop over the Blue Mtns this afternoon/evening but this is
a low probability event. A much better chance of thunderstorms
will occur later tonight from the Blue Mtns across the southern
Idaho Panhandle. These should move east of the area by mid-morning
Monday. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 85 58 84 58 88 60 / 0 10 20 0 0 0
Coeur d`Alene 84 56 82 54 86 58 / 0 10 20 10 0 0
Pullman 83 53 82 50 88 55 / 0 10 10 0 0 0
Lewiston 92 62 90 60 95 64 / 0 20 10 0 0 0
Colville 88 53 86 52 91 56 / 10 30 50 10 0 0
Sandpoint 83 51 79 49 85 53 / 0 10 50 20 0 0
Kellogg 83 55 80 54 87 57 / 0 10 20 10 0 0
Moses Lake 91 60 90 59 94 62 / 0 10 0 0 0 0
Wenatchee 89 62 89 63 92 65 / 10 20 0 0 0 0
Omak 89 58 89 58 93 60 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
942 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 942 PM CDT MON JUL 8 2013
TRYING TO FIGURE OUT THE CONVECTIVE EVOLUTION FORECAST FROM THE
OVERNIGHT HOURS THROUGH TUESDAY REMAINS VERY PROBLEMATIC.
FIRST...A LINE OF SHOWERS AND THUNDERSTORMS SET UP JUST NORTH OF
US-20 AND NEAR THE CLAYTON/GRANT COUNTY LINE. THESE STORMS WERE
ALONG A QUASI-STATIONARY FRONTAL BOUNDARY AND AIDED BY MLCAPES OF
2000-2500 J/KG PER RAP ANALYSIS. THEY HAVE BEEN VERY EFFICIENT
RAIN PRODUCERS WITH RAINFALL RATES OF 1 TO 2 INCHES PER HOUR BEING
OBSERVED IN EDGEWOOD AND GREELEY IA. LACK OF ANY 0-6KM SHEAR HAS
RESULTED IN THE STORMS COLLAPSING. ADDITIONALLY...LOSS OF DAYTIME
HEATING ALLOWING THE CAPE TO DIMINISH...THOUGH DEWPOINTS UP IN
THE MID 70S POOLED ALONG THE BOUNDARY RESULTING IN A SLOW
DIMINISHMENT. ANTICIPATING THESE STORMS MAY END UP FALLING PART IN
THE NEXT HOUR.
NOW FOR THE OVERNIGHT INTO TUESDAY. CONVECTION ACROSS SOUTH DAKOTA
AND NEBRASKA HAS BEEN MUCH LESS THAN WHAT MANY MODELS UP TO THIS
POINT HAD SUGGESTED...INCLUDING HIGH RESOLUTION MODELS. THUS...THE
IDEA OF AN MCS ROLLING OUT OF THIS REGION AND IMPACTING THE
FORECAST AREA LATE TONIGHT IS VERY MUCH IN QUESTION. LOOKING AT
OBSERVATIONAL DATA...THERE IS A SHORTWAVE OVER SOUTHWEST SOUTH
DAKOTA INTO FAR WESTERN NEBRASKA WITH ISOLATED CONVECTION
ACCOMPANYING IT. AHEAD OF THE SHORTWAVE...850MB WINDS HAVE BEEN
INCREASING OVER KANSAS AND NEBRASKA PER RADAR/PROFILER DATA...WITH
HINTS OF A WARM FRONTAL ZONE ACROSS SOUTHERN NEBRASKA. THIS IS
SHOWN TOO IN LATEST SURFACE ANALYSIS. ONCE THESE FEATURES MEET
UP...LIKELY IN CENTRAL/EASTERN NEBRASKA...WOULD IMAGINE CONVECTION
WILL INCREASE THERE. THE CONVECTION WILL LIKELY HEAD EAST THROUGH
THE MEAN FLOW TOWARDS SOUTHERN SECTIONS OF THE FORECAST
AREA...UNLESS IT UPSCALES INTO AN MCS...WHICH THEN MAY HEAD
SOUTHEAST AWAY FROM THE AREA PER BOTH NORMAL CORFIDI VECTORS AND
PROPAGATING CORFIDI VECTORS.
HEADING INTO TUESDAY...THERE ARE INDICATIONS FROM THE 09.00Z
NAM/RAP...08.12Z ECMWF/REGIONAL CANADIAN AND 08.18Z GFS OF 850MB
MOISTURE TRANSPORT PICKING UP ACROSS CENTRAL IOWA...WITH THE NOSE
OF IT POINTED RIGHT INTO THE FORECAST AREA AT 18Z. THIS COULD
CONCEIVABLY INITIATE PLENTY OF CONVECTION FROM LATE MORNING
THROUGH A BULK OF THE AFTERNOON HOURS. THESE WOULD BE EFFICIENT
RAIN PRODUCERS GIVEN DEEP WARM CLOUD DEPTHS AND PRECIPITABLE WATER
VALUES UPWARDS OF 2 INCHES. IF THIS CONVECTION FORMS...BY THE TIME
THE COLD FRONT COMING THROUGH MINNESOTA APPROACHES THE FORECAST
AREA IN THE EVENING...WE MAY NOT HAVE ENOUGH INSTABILITY TO DO
MUCH WITH IT.
WE WILL JUST HAVE TO SEE HOW OVERNIGHT CONVECTION PLAYS
OUT...SINCE AN MCV GOING SOUTH OF US COULD PRODUCE ENOUGH
SUBSIDENCE TO PRECLUDE MUCH CONVECTION IN ITS WAKE FOR TUESDAY.
THE PRESENCE OF THE MCV WOULD LIKE DISTORT THE PROGGED 850MB
MOISTURE TRANSPORT ZONE TOO. TUESDAY THEN WOULD BE A VERY WARM DAY
AGAIN WITH HIGHS ABOVE CURRENT FORECAST...WITH SEVERE WEATHER
POTENTIAL IN THE EVENING AS THE COLD FRONT MOVES IN.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
WARM FRONT SLATED TO WAVER WEST-EAST ACROSS SOUTHERN IA TONIGHT/TUE.
THE LOW LEVEL JET/MOISTURE TRANSPORT FOCUSES INTO THE BOUNDARY
ACROSS CENTRAL IA TONIGHT...AND SHOWER/STORMS SHOULD DEVELOP AS A
RESULT. THE LOW LEVEL FORCING PUSHES NORTHEAST ACROSS THE FORECAST
AREA TUE MORNING WHILE A PIECE OF UPPER LEVEL ENERGY TRACKS FROM THE
NORTHERN PLAINS TO ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BETWEEN
12-18Z. WOULD EXPECT TO SEE A SHIFT NORTHWARD WITH THE MORE
FAVORABLE CONVECTIVE REGION AS A RESULT...MOSTLY ALONG AND NORTH OF
I-90. A STRONGER UPPER LEVEL SHORTWAVE TROUGH PROGGED TO SLIP ACROSS
THE NORTHERN PLAINS AND INTO NORTHERN MN BY 00Z WED. A COLD FRONT
WILL SURGE AHEAD OF THIS SHORTWAVE...GETTING TO THE MISSISSIPPI
RIVER BY 00Z. THE GFS AND NAM BUILD 4000+ J/KG OF MUCAPE AHEAD OF
THE FRONT...WITH 40+ KTS OF 0-6 KM SHEAR. INSTABILITY WILL DEPEND ON
HOW LONG THE MORNING SHOWERS/STORMS LINGER ACROSS THE LOCAL
AREA...AND HOW QUICKLY THE DEBRIS CLOUDS CLEAR. AS IT STANDS...IF
PARAMETERS MANIFEST PER MODELED FORECAST...IT WOULD BE A GOOD SETUP
FOR SEVERE WEATHER. HOWEVER...IF PCPN LINGERS LINGERS...INSTABILITY
WILL BE MUCH LOWER...LESSENING THE SEVERE THREAT. A VERY CONDITIONAL
SEVERE WEATHER THREAT THAT WON/T BECOME CLEARER UNTIL THE AFTERNOON
HOURS.
HERE IS HOW TUE COULD PLAY OUT...MORNING CONVECTION ASSOCIATED WITH
THE LOW LEVEL JET ADVANCES NORTHEAST ACROSS THE REGION. COULD BE
SOME LINGERING SHOWERS/STORMS IN THE AFTERNOON...BUT ENVISION A
BREAK FROM THE WIDESPREAD PCPN CHANCES. SHOWERS/STORMS SPARK ALONG
AND AHEAD OF THE COLD FRONT BY LATE AFTERNOON/EVENING. MAYBE A
BETTER CHANCE NORTH OF I-94. ALSO...BELIEVE THE HIGHER SEVERE RISK
WILL BE DURING THIS TIME.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FROM
THE WEST ON WEDNESDAY...AND LOOKS TO BE THE MAIN WEATHER INFLUENCE
THROUGH THE BETTER PART OF FRIDAY. THE HEAT/HUMIDITY OF THE PAST FEW
DAYS WILL SWEEP EAST DURING THIS PERIOD...WITH COMPARATIVELY COOLER
AND LESS MUGGY CONDITIONS RESULTING.
AN UPPER LEVEL SHORTWAVE TROUGH IS THEN SLATED TO DRIVE FROM THE PAC
NW TO ACROSS SOUTHERN CANADA FOR THE UPCOMING WEEKEND. WHILE CURRENT
TRENDS FAVOR KEEPING MOST OF THE UPPER LEVEL ENERGY NORTH OF THE
FORECAST AREA...THE GFS AND ECMWF WOULD SLIDE AN ASSOCIATED COLD
FRONT ACROSS THE REGION. WITH THE WINDS FLIPPING TO THE SOUTH AS THE
HIGH EEKS TO THE EAST...LOW LEVEL MOISTURE WOULD INCREASE AHEAD OF
THE SFC BOUNDARY...AS WOULD INSTABILITY. EXPECT SOME CONVECTION
AROUND THE FRONT AS RESULT. DETAILS ON WHEN/WHERE ISN/T CLEAR AT
THIS TIME...WITH SOME MODEL DIFFERENCES ON TIMING AND PLACEMENT OF
THE RELEVANT FEATURES. THE SFC FRONT COULD THEN GET HUNG UP FROM
WEST TO EAST ACROSS THE REGION...SERVING AS A POSSIBLE SHOWER/STORM
FOCUS THROUGH THE WEEKEND. WILL LEAN ON THE CONSENSUS/EC SOLUTION
FOR PCPN CHANCES FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 618 PM CDT MON JUL 8 2013
DAYTIME MIXING HAS HELPED TO CLEAR OUT THE CLOUDS THAT WERE
PRESENT DURING THE DAY TODAY AROUND THE TAF SITES. MUCH OF THE
EVENING APPEARS IT SHOULD BE CLEAR...AND COMBINED WITH LIGHT WINDS
AND THE HIGH 70 DEGREE F DEWPOINTS IN PLACE WILL LIKELY LEAD TO
SOME MVFR BR DEVELOPING AROUND MIDNIGHT. LATE IN THE NIGHT...
NUMEROUS COMPUTER MODELS SUGGEST THUNDERSTORMS DEVELOPING ACROSS
SOUTH DAKOTA AND NEBRASKA WILL BEGIN TO APPROACH THE TAF SITES.
THE TRACK AND TIMING OF THESE ARE STILL UNCERTAIN...THOUGH...WITH
POTENTIAL FOR THEM TO DIVE MORE TO THE SOUTH OF THE TAF SITES.
CONSENSUS SEEMS TO SUGGEST THAT THE PRECIPITATION WILL CROSS RST
BETWEEN 11-17Z AND LSE BETWEEN 13-18Z. DID NOT CHANGE THE VCTS TO
-TSRA YET BECAUSE OF CONCERN ON THE TRACK OF THE STORMS. AS THE
THUNDERSTORM EVOLUTION BECOMES CLEARER ACROSS SOUTH DAKOTA AND
NEBRASKA...MORE DETAIL WILL BE PROVIDED TO THE TAFS. FOR THE
AFTERNOON...A COLD FRONT IS FORECAST TO DROP SOUTHEAST THROUGH
MINNESOTA. THIS FRONT WILL LIKELY TRIGGER MORE STORMS BUT THESE
MAY NOT MAKE INTO THE TAF SITES UNTIL AFTER 00Z. HOWEVER...WITH A
MUGGY AIRMASS IN PLACE AND DAYTIME HEATING IN THE WAKE OF MORNING
PRECIPITATION...ADDITIONAL SHOWER ACTIVITY FROM VFR CUMULUS MAY
FORM DURING THE AFTERNOON. THUS HAVE A VCSH FROM 18-00Z IN BOTH
TAFS. VISIBILITIES ARE LIKELY TO IMPROVE TO VFR FOR THE AFTERNOON
TOO AIDED BY DAYTIME HEATING.
&&
.HYDROLOGY...(TUESDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
PWS CLOSE TO 2 INCHES THROUGH TUE...AROUND 170 PERCENT OF
NORMAL...WHILE WARM CLOUD DEPTH IS 3500-4000 M. ALL SUPPORT THE
POTENTIAL FOR HEAVY RAIN. HOWEVER...THE EXPECTED PCPN LOOKS
TRANSITORY...NOT LINGERING NOR MUCH TRAINING....WHILE FFG IS 2.5-3
INCHES IN 3 HOURS. THE MOISTURE TRANSPORT ISN/T OVERLY STRONG NOR
DOES IT FOCUS FOR A PROLONGED PERIOD. SO...WHILE THE ATMOSPHERE
COULD SUPPORT HEAVY RAIN...OTHER ASPECTS MINIMIZE A FLASH FLOOD
THREAT. IF PCPN RATES COULD BECOME HIGH ENOUGH...FLASH FLOODING OR
URBAN/CITY FLOODING WOULD BE POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...AJ
HYDROLOGY....DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 PM CDT SUN JUL 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS GOING INTO TOMORROW IS WITH THE CHANCES FOR RAIN
SHOWERS/THUNDERSTORMS AS A COLD FRONT MOVES THROUGH THE REGION.
CURRENTLY...A HUMID AIR MASS IS IN PLACE AT THE SURFACE AS DEW
POINTS CONTINUE TO RISE IN RESPONSE TO AN INCREASE OF LOW LEVEL
MOISTURE TRANSPORT OUT OF THE GULF. SURFACE ANALYSIS SHOWS TWO
COLD FRONTS IN THE VICINITY OF WESTERN MINNESOTA. THE FIRST ONE
EXTENDS FROM NORTHERN WISCONSIN DOWN THROUGH SOUTH CENTRAL
MINNESOTA AND EASTERN NEBRASKA. THE SECOND COLD FRONT IS JUST TO
THE WEST OF THIS OTHER FRONT AND EXTENDS FROM A SURFACE LOW IN
SOUTHERN MANITOBA DOWN THROUGH WESTERN MINNESOTA AND EASTERN SOUTH
DAKOTA. WITH DEW POINTS IN THE LOW 70S BETWEEN THESE TWO
FRONTS...07.19Z RAP ANALYSIS SHOWS AN AXIS OF 3000 J/KG OF SURFACE
BASED CAPE. CONVECTION HAS INITIATED ALONG THE FIRST FRONT AND A
LAKE BREEZE BOUNDARY NORTHWEST OF THE TWIN CITES AND DOWN ALONG
THE FRONT. FURTHER ALOFT...MID LEVEL RIDGING EXTENDS FROM THE
SOUTHERN PLAINS THROUGH THE UPPER GREAT LAKES. A MID LEVEL SHORT
WAVE TROUGH IS CURRENT IN THE DAKOTAS AND WILL TRACK TO THE EAST
THROUGH TONIGHT AND IS TIED TO THE SECONDARY COLD FRONT.
THE ENVIRONMENT AHEAD OF THE COLD FRONTS APPEARS TO BE CAPPED
AROUND 800MB...SO AM NOT EXPECTING ANY DEVELOPMENT OUT IN THE WARM
SECTOR DESPITE THE HIGH CAPE ENVIRONMENT. THE MAIN CHANCES WILL
BE AS THE FRONT AND WEAKENING MID LEVEL TROUGH COME THROUGH THIS
EVENING AND OVERNIGHT. THE FRONT WILL THEN PUSH THROUGH AND STALL
TO THE SOUTH OF THE REGION IN IOWA ON MONDAY. HAVE DROPPED THE
PRECIPITATION CHANCES DOWN A LITTLE ON MONDAY AS IT LOOKS LIKE
SURFACE TO UPPER LEVEL RIDGING WILL SETTLE IN FOR A BRIEF PERIOD
AND KEEP THE REGION MORE ON THE DRY SIDE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN FOCUS IN THE LONG TERM IS ON MONDAY NIGHT INTO TUESDAY
AND WITH WHERE A MESOSCALE CONVECTIVE SYSTEM WILL DEVELOP AND
TRACK THROUGH ON TUESDAY MORNING.
THE 07.12Z GUIDANCE CONTINUES TO GIVE SOME UNCERTAINTY WITH THE
TRAJECTORY OF THIS MCS. THE GFS/NAM TAKE A MORE SOUTHERLY ROUTE
ACROSS IOWA DUE TO THE LOW LEVEL JET/MOISTURE TRANSPORT ONLY
REACHING EASTERN NEBRASKA BY 6Z TUESDAY. THE PERFERRED GUIDANCE IS
FROM THE ECMWF/GEM SOLUTION WHICH PUSH THE LLJ NOSE INTO EASTERN
SOUTH DAKOTA BY THIS TIME...AND DESPITE THE GEM/ECMWF SHOWING THE
MAIN QPF STAYING WELL TO THE NORTH OF THE REGION TOWARD
DULUTH...AM CONCERNED THAT THE MCS WOULD DEVELOP IN WESTERN
MINNESOTA AND RUN EAST SOUTHEAST ALONG THE NOSE OF THE LOW LEVEL
JET AND INSTABILITY GRADIENT. THIS IDEA FOLLOWS WELL WITH FORECAST
CORFIDI VECTORS WHICH POINT TO THE SOUTHEAST TUESDAY
MORNING...WHICH WOULD TAKE IT STRAIGHT THROUGH THE MIDDLE OF THE
FORECAST AREA ALONG THE MINNESOTA/IOWA BORDER INTO WESTERN
WISCONSIN. GIVEN THE MODEL DIFFERENCES...HAVE NOT HIT THE
PRECIPITATION CHANCES TOO HIGH YET AND WILL HAVE TO SEE HOW THE
PATTERN EVOLVES INTO TOMORROW. WITH THE INCREASING MOISTURE
TRANSPORT AND POTENTIAL FOR HEAVY RAIN...FLASH FLOODING WILL BE A
THREAT DESPITE THE RECENT DRY SPELL. DETAILS ARE OUTLINED IN THE
HYDROLOGY AFD SECTION.
THIS MCS CAUSES SOME HAVOC GOING INTO THE AFTERNOON ON TUESDAY
AND WHAT THE SEVERE THUNDERSTORM CHANCES ARE AFTER ITS PASSAGE. IF
THE SYSTEM TRACKS TO THE SOUTH...THEN IT LIKELY KEEPS THE MAIN
WARM FRONT DOWN THERE AS WELL AND LIMITS THE SEVERE POTENTIAL. IF
IT TRACKS THROUGH THE HEART OF THE FORECAST AREA...AS WE THINK IT
MAY...THE QUESTION WILL BE HOW FAST DOES IT CLEAR AND ALLOW THE
ENVIRONMENT TO RECHARGE BY PEAK HEATING. IF THE SYSTEM WERE TO
CLEAR EARLY ENOUGH AND ALLOW FOR DESTABILIZATION BY LATE AFTERNOON
OUR SEVERE THREAT WOULD BE FAIRLY HIGH DUE TO A VEERING 0-6KM
SHEAR PROFILE...HIGH INSTABILITY...AND DEEP FORCING FROM A SURFACE
LOW AND MID LEVEL TROUGH. WITH A LINGERING OUTFLOW BOUNDARY/WARM
FRONT IN THE REGION...THE HAZARDS WOULD INCLUDE LARGE
HAIL...FLASH FLOODING...DAMAGING WINDS AND THE POSSIBILITY OF A
TORNADO OR TWO GIVEN THE HIGH 0-1KM SHEAR/HELICITY. THE THING
IS...CONFIDENCE IS JUST NOT THERE YET TO LEAN ONE WAY OR ANOTHER
UNTIL THERE IS BETTER CONCENSUS ON THE TRACK OF THE EARLY MORNING
MCS.
BEYOND THIS SYSTEM...IT LOOKS LIKE A DRY AND SEASONAL PERIOD
THROUGH THE REST OF THE WEEK AS UPPER LEVEL RIDGING SETS UP ACROSS
THE UPPER MISSISSIPPI RIVER VALLEY. A COLD FRONT WILL APPROACH THE
REGION FROM THE WEST BY NEXT WEEKEND AND COULD BRING THE NEXT SHOT
OF RAIN ALONG WITH IT. THERE ARE SOME TIMING DIFFERENCES BETWEEN
THE 07.12Z GFS AND ECWMF WITH THIS FEATURE THAT WILL BE RUNNING
INTO THE RIDGING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1238 PM CDT SUN JUL 7 2013
AT MID DAY A TROUGH/FRONTAL BOUNDARY REMAINED WELL NORTHWEST OF THE
FCST AREA. A MOIST/UNSTABLE AIR MASS WAS IN PLACE ALONG/AHEAD OF THE
FRONT...WITH THE STRONGEST INSTABILITY NEAR THE FRONT. GENERALLY
GOOD VFR EXPECTED THIS AFTERNOON...BUT SOME MOISTURE TRANSPORT INTO
THE AREA AHEAD OF THE FRONT MAY GENERATE WDLY SCT SHRA/TSRA IN/
AROUND THE AREA LATER THIS AFTERNOON INTO THE EVENING. WITH LOWER
CONFIDENCE IN THE CONVECTION CHANCES/COVERAGE THIS AFTERNOON...ONLY
CARRIED A VCSH IN THE TAFS FROM 21-03Z FOR NOW.
THE TROUGH/FRONT LOOKS TO SLIDE THRU THE AREA LATE THIS EVENING INTO
THE OVERNIGHT HOURS. SHRA/TSRA CHANCES APPEAR QUITE LIMITED ONCE THE
BOUNDARY PASSES. HOWEVER WITH WEAK PRESSURE GRADIENTS AND THE MOIST
LOW LEVEL AIR MASS OVER THE AREA...LATE NIGHT/EARLY MORNING
RADIATIONAL BR/FG BECOMES A CONCERN AT BOTH TAF SITES. UNTIL DETAILS
BECOME CLEARER...CONTINUED THE MVFR/IFR BR MENTION AT BOTH SITES IN
THE 09Z-13Z TIME-FRAME. LOWER LEVEL MOISTURE LINGERS OVER THE AREA
BEHIND THE FRONT ON MON...WITH SOME CUMULUS IN THE 3K-4K FT RANGE
EXPECTED.
&&
.HYDROLOGY...TUESDAY
ISSUED AT 305 PM CDT SUN JUL 7 2013
THE MAIN HYDRO CONCERNS COME IN ON TUESDAY AS A COMPLEX OF
THUNDERSTORMS IS FORECAST TO TRACK THROUGH THE REGION. THE
QUESTION IS WHERE AND WHEN WILL IT COME THROUGH? MOST OF THE MODEL
GUIDANCE SUGGEST THAT THIS SYSTEM WILL FORM IN NORTHWEST NEBRASKA
AND RUN EAST ACROSS IOWA MONDAY NIGHT INTO TUESDAY MORNING. WITH
SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP AHEAD OF THIS
COMPLEX NORTH OF A WARM FRONT...THE POTENTIAL IS THERE FOR SOME
HEAVY RAIN TO FALL. THANKFULLY...CONDITIONS HAVE BEEN DRY FOR THE
PAST WEEK...SO FLASH FLOOD GUIDANCE HAS COME UP CONSIDERABLY AND
THE SOIL SHOULD BE ABLE TO HANDLE THE EXCESS MOISTURE REASONABLY
WELL FOR A PERIOD. THAT SAID...INCREASING PRECIPITABLE WATER
VALUES AND LOW LEVEL MOISTURE TRANSPORT AIMING INTO THE
REGION...EXPECT THAT HEAVY RAIN AND FLASH FLOODING IS POSSIBLE
WITH SOME RENEWED RISES ON AREA RIVERS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RRS
HYDROLOGY...HALBACH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST TUE JUL 9 2013
.SYNOPSIS...HIGH PRESSURE ALOFT WILL BE NEAR THE FOUR CORNERS REGION
THIS WEEK. THUNDERSTORM COVERAGE WILL INCREASE THIS WEEK AS THE FLOW
BECOMES MORE FAVORABLE TO PUSH STORMS INTO VALLEY LOCATIONS AND
DEEPER MOISTURE ADVANCES FROM THE SOUTH AND SOUTHEAST. EXPECT
SOMEWHAT LESS COVERAGE OF THUNDERSTORMS BY SUNDAY FOLLOWED BY
ANOTHER INCREASE IN THUNDERSTORMS EARLY NEXT WEEK.
&&
.DISCUSSION...EXPANSIVE MCS EXTENDED FROM SRN SONORA INTO SRN ARIZONA
EARLY THIS MORNING. FAIRLY WIDESPREAD COVERAGE OF SHOWERS PRODUCING
LIGHT RAINFALL...AND A FEW THUNDERSTORMS...WERE ONGOING ACROSS SE
AZ. THIS ACTIVITY AS PER THE 09/07Z RUC HRRR WILL MOVE WWD ACROSS
THE AREA THRU MID-MORNING...THEN DECREASE IN COVERAGE BY LATE
MORNING ACROSS WRN PIMA COUNTY. THEREAFTER...ADDITIONAL SHOWERS AND
THUNDERSTORMS ARE PROGGED TO DEVELOP EARLY THIS AFTERNOON MAINLY
ACROSS THE MOUNTAINS AND ACROSS THE TOHONO OODHAM NATION. ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE THEN PROGGED TO ADVANCE SWWD FROM THE
WHITE MOUNTAINS LATE THIS AFTERNOON.
CONFIDENCE IN THIS FORECAST SCENARIO IS SOMEWHAT LOW GIVEN THE
ONGOING MCS. AT ANY RATE...THE OFFICIAL FORECAST DEPICTS SCATTERED
SHOWERS/TSTMS THIS AFTERNOON AND THIS EVENING FROM TUCSON EWD/SWD
WITH LESSER PRECIP COVERAGE ACROSS WRN PIMA COUNTY. HAVE MAINTAINED
A SLIGHT CHANCE OF SHOWERS/TSTMS ACROSS MUCH OF SE AZ LATE TONIGHT.
WED-FRI...
09/00Z GFS/ECMWF WERE SIMILAR WITH DEPICTING A POTENTIAL MID TO
HIGH-GRADE MONSOON REGIME. MID-LEVEL STEERING FLOW WILL BECOME
INCREASINGLY SELY THUR-FRI AS THE FOUR CORNERS UPPER HIGH MOVES INTO
THE CENTRAL CONUS PLAINS. SCATTERED TO PERHAPS NUMEROUS SHOWERS AND
TSTMS SHOULD OCCUR WED-FRI PARTICULARLY DURING THE AFTERNOON AND
EVENING HOURS. HAVE TRENDED POPS UPWARD GENERALLY ABOUT 10 PERCENT
EACH FORECAST PERIOD. GFS PWATS PROGGED TO BE NEAR 1.80 INCHES
ACROSS WRN PIMA COUNTY...AND ABOUT 1.30 INCHES NEAR THE NEW MEXICO
BORDER. THE INCREASED MOISTURE MAY PRODUCE SOME HEAVY DOWNPOURS
LEADING TO AT LEAST LOCALIZED FLOODING.
SAT-MON...
EXPECT THE COVERAGE OF SHOWERS/TSTMS TO REDUCE THIS WEEKEND AS MID-
LEVEL DRYING IS PROGGED VIA THE GFS/ECMWF. SUNDAY SHOULD EXPERIENCE
THE LEAST COVERAGE OF SHOWERS/TSTMS. THEREAFTER...PRECIP CHANCES
WILL INCREASE NEXT MONDAY AS AN UPPER LEVEL LOW PRESSURE SYSTEM
MOVES WWD ACROSS SRN TEXAS AND INTO CHIHUAHUA.
THE OFFICIAL FORECAST HIGH TEMP TODAY AT THE TUCSON INTERNATIONAL
AIRPORT IS 100 DEGREES. ACHIEVING 99 DEGREES OR COOLER WOULD END THE
CURRENT 38 CONSECUTIVE DAY STREAK OF TRIPLE DIGIT TEMPS AT TIA.
THEREAFTER...DAYTIME TEMPS WILL AVERAGE A FEW DEGS BELOW NORMAL
WED-FRI FOLLOWED BY SLIGHTLY WARMER DAYTIME TEMPS THIS WEEKEND.
&&
.AVIATION...VALID THRU 10/12Z...
SCT -SHRA AND ISOLD -TSRA THIS MORNING THEN SCT TSRA/SHRA THIS
AFTERNOON AND THIS EVENING. BRIEF WIND GUSTS OF 40-45 KTS INTO EARLY
THIS EVENING WITH THE STRONGEST TSRA. ISOLD-SCT -SHRA LATE TONIGHT
AND EARLY WEDNESDAY MORNING. OTHERWISE...VFR CONDITIONS AND SURFACE
WIND GENERALLY LESS THAN 10 KTS THRU EARLY WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED THUNDERSTORMS PRODUCING LOCALLY HEAVY
RAINFALL WILL OCCUR THROUGH SATURDAY. SOMEWHAT DRIER AIR WILL LESS
COVERAGE OF THUNDERSTORMS SUNDAY. THEREAFTER...AN UPPER LEVEL LOW
PRESSURE SYSTEM APPROACHING FROM THE EAST WILL PROVIDE INCREASED
THUNDERSTORM COVERAGE NEXT MONDAY. THE STRONGER THUNDERSTORMS INTO
EARLY NEXT WEEK WILL PRODUCE GUSTY AND ERRATIC WINDS. OTHERWISE...
NORMAL DIURNAL WIND TRENDS WILL OCCUR...WITH OCCASIONAL AFTERNOON
GUSTINESS DUE TO DAYTIME HEATING.
&&
.CLIMATE...THE HIGH TEMPERATURE AT TUCSON INTERNATIONAL AIRPORT
REACHED 105 DEGREES MONDAY. THUS...MONDAY BECAME THE 38TH
CONSECUTIVE DAY OF TRIPLE DIGIT TEMPS RECORDED AT TUCSON
INTERNATIONAL AIRPORT. THIS IS THE THIRD LONGEST STREAK ON RECORD
BEHIND 1987 AND 2005 (BOTH YEARS WITH 39 CONSECUTIVE DAYS).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
BF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
331 AM EDT TUE JUL 9 2013
.DISCUSSION...
TODAY-TONIGHT...THERE WAS LITTLE CHANGE WITH THE 00Z GFS. IT WAS
STILL SHOWING MID/UPPER LEVEL (TUTT) LOW PRESENTLY CENTERED NEAR
ANDROS ISLAND PUSHING WEST NORTHWEST INTO THE SOUTHERN TIP OF THE
FLORIDA PENINSULA. ATMOSPHERE WILL GRADUALLY MOISTEN...ESPECIALLY
ACROSS THE SOUTH HALF OF THE AREA...WHILE WEAK VORT MAXIMA ROTATE
AROUND THE LOW AND INCREASE LIFT.
MOS POPS TODAY RANGE FROM 50 PERCENT IN THE FAR SOUTH TO 30
PERCENT ELSEWHERE. EVEN THOUGH THE GFS IS NOT GENERATING MUCH
PRECIP...WILL GO WITH 40-50 PERCENT POPS ALONG THE TREASURE COAST
SINCE THERE IS A DECENT SWATH OF SHOWERS ABOUT 100 MILES OFFSHORE
SOUTH OF CANAVERAL. ELSEWHERE WILL STAY CLOSE TO THE PREVIOUS
FORECAST...30 PERCENT...EXCEPT 20 PERCENT ALONG THE NORTH COAST
WHERE THE GFS AND NAM GENERATE NO PRECIP.
COOLING ALOFT IS SHOWN BY THE LATEST RAP ANALYSIS WITH LIGHTNING
DETECTION EQUIPMENT SHOWING A FEW STRIKES EAST OF OUR COASTAL
WATERS. THEREFORE EXPECT THAT AFTER A SEVERAL DAY HIATUS FROM
LIGHTNING...THERE WILL BE A RETURN OF ISOLATED STORMS...ESPECIALLY
INLAND AND OVER THE COASTAL WATERS.
WEDNESDAY/THURSDAY...LITTLE CHANGE TO THE MID WEEK FORECAST AS TUTT
CURRENTLY OVER THE BAHAMAS TRACKS ACROSS SOUTH FLORIDA ON
WEDNESDAY...BEFORE BEING ABSORBED INTO LARGER SCALE UPPER TROUGH
SWINGING THROUGH THE EASTERN CONUS ON THURSDAY. AT THE SAME TIME THE
LOW LEVEL WESTERN ATLC RIDGE WILL SLIDE SOUTH IN RESPONSE TO THE
FRONTAL TROUGH MOVING THROUGH THE EASTERN AND SOUTHEASTERN
US...ENDING UP OVER OR JUST SOUTH OF THE AREA BY THURSDAY.
FLOW WILL BE WEAK ENOUGH FOR BOTH SEA BREEZES TO FORM EACH
AFTERNOON...WITH THE STEERING FLOW SHIFTING FROM SOUTH-SOUTHEAST ON
WEDNESDAY TO SOUTHWEST ON THURSDAY AS THE AREA GETS SQUEEZED IN
BETWEEN THE LARGER UPPER LEVEL TROUGH TO THE NORTH AND WESTERN
ATLANTIC RIDGE NOSING IN.
THE TUTT WILL BRING COLDER TEMPS ALOFT...ESPECIALLY ACROSS THE
SOUTH...AND THE DEEPER MOISTURE WILL SUPPORT RAIN CHANCES AT OR
JUST ABOVE NORMAL AT 40-50 PERCENT.
FRIDAY/WEEKEND...UPPER LEVEL EAST COAST TROUGH DEEPENS ON
FRIDAY...WITH THE SOUTHERN EXTENT OF THE TROUGH SPLITTING ON
SATURDAY. THIS WILL LEAVE ANOTHER UPPER LEVEL LOW TO MEANDER
SOUTHWESTWARDS ACROSS THE DEEP SOUTH AND WESTERN GULF OF MEXICO BY
THE END OF THE WEEKEND.
AT THE SURFACE...THE OFFICIAL TRACK FOR TS CHANTAL HAS IT MOVING
THROUGH THE CENTRAL AND NORTHERN BAHAMAS FRIDAY AND SATURDAY WITH
SOME QUESTION AS TO IF IT WILL SURVIVE THE EFFECTS OF LAND
INTERACTION AND WIND SHEAR AFTER IT CROSSES HISPANIOLA LATE THURSDAY.
WHAT INFLUENCE THE SYSTEM OR ITS REMNANTS WILL PLAY IN THE LOCAL
WEATHER FOR THE WEEKEND IS STILL UNCLEAR. WILL KEEP POPS NEAR
CLIMO THROUGH THE PERIOD AS FUTURE FORECASTS FOR CHANTAL UNFOLD.
&&
.AVIATION...
LOCAL MVFR IN ONSHORE MOVING SHOWERS MAINLY KMLB-KSUA WITH SLIGHT
CHANCE FOR LIGHTNING IN THE VICINITY...ESPECIALLY THIS MORNING AND
EARLY AFTERNOON. PROBABILITY FOR THESE CONDITIONS IN THE AFTERNOON
FROM KISM/KMCO TO KSFB/KLEE ARE TOO LOW TO MENTION IN TAFS YET.
&&
.MARINE...
TODAY-TONIGHT...SURFACE RIDGE AXIS SETTLING INTO NORTH FLORIDA
WILL REDUCE THE ONSHORE FLOW TO 10 KNOTS OR LESS. THERE WILL BE
ISOLATED TO SCATTERED SHOWERS AND A FEW LIGHTNING STORMS...
ESPECIALLY SOUTH OF CANAVERAL.
WED-SAT...SOUTH-SOUTHEAST WINDS ON WEDNESDAY AND THURSDAY INTO
THE END OF THE WEEK AS THE ATLANTIC RIDGE AXIS SLIDES INTO CENTRAL
FLORIDA. SPEEDS AROUND 10-15KTS THROUGH THE PERIOD...WITH A
STRONGER ONSHORE COMPONENT DEVELOPING NEARSHORE EACH AFTERNOON
WITH THE EAST COAST SEA BREEZE. SEAS 2-4FT.
FORECAST FROM SATURDAY ONWARDS BECOMES HIGHLY UNCERTAIN AS TC
CHANTAL...OR ITS REMNANTS...ARE FORECAST TO BE IN THE CENTRAL AND
NORTHERN BAHAMAS BY LATE FRIDAY INTO SATURDAY. WIND SPEEDS/DIRECTION
AND SEAS WILL BE HIGHLY DEPENDENT ON HOW CHANTAL EVOLVES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 72 89 74 / 20 20 30 20
MCO 92 71 92 73 / 30 10 30 20
MLB 89 73 89 75 / 30 20 40 30
VRB 88 71 89 74 / 40 20 40 30
LEE 92 72 93 75 / 20 10 40 20
SFB 92 73 93 75 / 30 10 30 20
ORL 92 73 93 76 / 30 10 30 20
FPR 87 71 88 74 / 40 20 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...LASCODY
LONG TERM....MOSES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
437 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* FOG WITH REDUCED VIS OF 4SM-6SM DEVELOPING EARLY THIS MORNING.
* SHOWERS WITH POSSIBLE TS REDEVELOPING LATER THIS MORNING AND
CONTINUING THROUGH LATE MORNING.
* REDEVELOPMENT OF SHOWERS/TS ONCE AGAIN LATER THIS AFTERNOON.
* MORE WIDESPREAD SHOWERS/TS EXPECTED TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT.
* COMPLEX WIND FORECAST WITH VARIABLE/LIGHT WINDS BECOMING
NORTHEAST LATER THIS MORNING...THEN SHIFTING MORE SOUTHERLY
LATER THIS AFTERNOON AND EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
A VERY COMPLEX FORECAST PERIOD FOR THE TERMINALS OVER THE NEXT 24
HOURS AS VARYING WEATHER CONDITIONS AT MULTIPLE TIMES COULD HAVE
IMPACTS ON THE TERMINALS. IN THE NEAR TERM...THE SHOWERS/TS WHICH
HAD DEVELOPED ACROSS NORTHEAST ILLINOIS AND OVER SOUTHERN LAKE
MICHIGAN HAVE SINCE DIMINISHED EARLY THIS MORNING...AND THINK ANY
FURTHER DEVELOPMENT SHOULD REMAIN VERY ISOLATED AND BRIEF OUTSIDE
OF THE TERMINALS. WITH EXPECTED CLEARING...LIGHT WINDS AND A VERY
MOIST ENVIRONMENT SHOULD SUPPORT FOG DEVELOPMENT OVER THE
TERMINALS THIS MORNING WITH VIS RESTRICTION EXPECTED. OUTSIDE OF
THIS DEVELOPMENT...A LIGHT NORTHERLY WIND OVER THE LAKE WITH LOW
CEILINGS AND VIS FURTHER NORTH TOWARDS THE MIDDLE PART OF THE LAKE
RAISES SOME CONCERNS FOR POTENTIAL LOWER CEILINGS AND FOG TO MOVE
ACROSS THE TERMINALS NEAR THE LAKE...ORD/MDW/GYY. EVEN IF THE
CLOUDS/FOG TO THE NORTH DONT QUITE MAKE IT THIS FAR SOUTH...COOLER
AIR MOVING INTO A VERY MOIST ENVIRONMENT COULD SUPPORT LOW
CLOUD/FOG DEVELOPMENT NEAR THE LAKE SHORE ANYWAYS. CONFIDENCE IS
LOW WITH REGARDS TO THE POTENTIAL BUT WILL NEED TO MONITOR THIS
AND ADJUST AS NEEDED.
EXPECT REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING AS ANOTHER
MID LEVEL DISTURBANCE APPROACHES FROM THE WEST...WITH THIS
SCATTERED DEVELOPMENT POSSIBLY CONTINUING THROUGH MID DAY.
ALTHOUGH SHOULD SEE A DIMINISHING TREND INTO THE EARLY
AFTERNOON...REDEVELOPMENT IN AND AROUND THE TERMINALS WILL ONCE
AGAIN BE POSSIBLE LATE THIS AFTERNOON THROUGH THE EARLY EVENING.
MORE WIDESPREAD SHOWERS/THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS
THE TERMINALS LATE THIS EVENING AND OVERNIGHT BEFORE EXITING EARLY
WEDNESDAY MORNING.
THE WIND FORECAST IS RATHER COMPLEX AS A WEAK GRADIENT WITH
SEVERAL BOUNDARIES MOVING ACROSS THE AREA ARE IN PLACE. WITH THESE
FEATURES IN PLACE...WIND DIRECTION AND SPEED WILL LIKELY RANGE
SUBSTANTIALLY FROM TERMINAL TO THE OTHER. LIGHT AND VARIABLE WINDS
FOR ALL OF THE TERMINALS EARLY THIS MORNING WILL PICK UP LATER
THIS MORNING WITH RFD THE ONLY SITE OBSERVING A MORE SOUTHERLY
DIRECTION EARLY ON. THE OTHER SITES SHOULD HOLD ONTO A NORTHEAST
DIRECTION LATER THIS MORNING...LIGHT AT FIRST BUT PICKING UP IN
SPEEDS. THEN AS THE GRADIENT TIGHTENS OUT AHEAD OF AN APPROACHING
SYSTEM...DO EXPECT A TRANSITION TO MORE OF A SOUTHERLY DIRECTION
TO OCCUR LATER THIS AFTERNOON AND THEN CONTINUE INTO THE EVENING
HOURS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE WITH FOG/REDUCED VIS.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWERS/TS THIS AFTERNOON.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS EVENING/OVERNIGHT.
* LOW/MEDIUM CONFIDENCE ON WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
* WEDNESDAY...CHANCE OF TSRA...MAINLY IN THE MORNING.
* THURSDAY THROUGH SUNDAY...DRY/VFR.
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
425 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* FOG WITH REDUCED VIS OF 4SM-6SM DEVELOPING EARLY THIS MORNING.
* SHOWERS WITH POSSIBLE TS REDEVELOPING LATER THIS MORNING AND
CONTINUING THROUGH LATE MORNING.
* REDEVELOPMENT OF SHOWERS/TS ONCE AGAIN LATER THIS AFTERNOON.
* MORE WIDESPREAD SHOWERS/TS EXPECTED TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT.
* COMPLEX WIND FORECAST WITH VARIABLE/LIGHT WINDS BECOMING
NORTHEAST LATER THIS MORNING...THEN SHIFTING MORE SOUTHERLY
LATER THIS AFTERNOON AND EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
A VERY COMPLEX FORECAST PERIOD FOR THE TERMINALS OVER THE NEXT 24
HOURS AS VARYING WEATHER CONDITIONS AT MULTIPLE TIMES COULD HAVE
IMPACTS ON THE TERMINALS. IN THE NEAR TERM...THE SHOWERS/TS WHICH
HAD DEVELOPED ACROSS NORTHEAST ILLINOIS AND OVER SOUTHERN LAKE
MICHIGAN HAVE SINCE DIMINISHED EARLY THIS MORNING...AND THINK ANY
FURTHER DEVELOPMENT SHOULD REMAIN VERY ISOLATED AND BRIEF OUTSIDE
OF THE TERMINALS. WITH EXPECTED CLEARING...LIGHT WINDS AND A VERY
MOIST ENVIRONMENT SHOULD SUPPORT FOG DEVELOPMENT OVER THE
TERMINALS THIS MORNING WITH VIS RESTRICTION EXPECTED. OUTSIDE OF
THIS DEVELOPMENT...A LIGHT NORTHERLY WIND OVER THE LAKE WITH LOW
CEILINGS AND VIS FURTHER NORTH TOWARDS THE MIDDLE PART OF THE LAKE
RAISES SOME CONCERNS FOR POTENTIAL LOWER CEILINGS AND FOG TO MOVE
ACROSS THE TERMINALS NEAR THE LAKE...ORD/MDW/GYY. EVEN IF THE
CLOUDS/FOG TO THE NORTH DONT QUITE MAKE IT THIS FAR SOUTH...COOLER
AIR MOVING INTO A VERY MOIST ENVIRONMENT COULD SUPPORT LOW
CLOUD/FOG DEVELOPMENT NEAR THE LAKE SHORE ANYWAYS. CONFIDENCE IS
LOW WITH REGARDS TO THE POTENTIAL BUT WILL NEED TO MONITOR THIS
AND ADJUST AS NEEDED.
EXPECT REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING AS ANOTHER
MID LEVEL DISTURBANCE APPROACHES FROM THE WEST...WITH THIS
SCATTERED DEVELOPMENT POSSIBLY CONTINUING THROUGH MID DAY.
ALTHOUGH SHOULD SEE A DIMINISHING TREND INTO THE EARLY
AFTERNOON...REDEVELOPMENT IN AND AROUND THE TERMINALS WILL ONCE
AGAIN BE POSSIBLE LATE THIS AFTERNOON THROUGH THE EARLY EVENING.
MORE WIDESPREAD SHOWERS/THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS
THE TERMINALS LATE THIS EVENING AND OVERNIGHT BEFORE EXITING EARLY
WEDNESDAY MORNING.
THE WIND FORECAST IS RATHER COMPLEX AS A WEAK GRADIENT WITH
SEVERAL BOUNDARIES MOVING ACROSS THE AREA ARE IN PLACE. WITH THESE
FEATURES IN PLACE...WIND DIRECTION AND SPEED WILL LIKELY RANGE
SUBSTANTIALLY FROM TERMINAL TO THE OTHER. LIGHT AND VARIABLE WINDS
FOR ALL OF THE TERMINALS EARLY THIS MORNING WILL PICK UP LATER
THIS MORNING WITH RFD THE ONLY SITE OBSERVING A MORE SOUTHERLY
DIRECTION EARLY ON. THE OTHER SITES SHOULD HOLD ONTO A NORTHEAST
DIRECTION LATER THIS MORNING...LIGHT AT FIRST BUT PICKING UP IN
SPEEDS. THEN AS THE GRADIENT TIGHTENS OUT AHEAD OF AN APPROACHING
SYSTEM...DO EXPECT A TRANSITION TO MORE OF A SOUTHERLY DIRECTION
TO OCCUR LATER THIS AFTERNOON AND THEN CONTINUE INTO THE EVENING
HOURS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE WITH FOG/REDUCED VIS.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWERS/TS THIS AFTERNOON.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS EVENING/OVERNIGHT.
* LOW/MEDIUM CONFIDENCE ON WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
* WEDNESDAY...CHANCE OF TSRA...MAINLY IN THE MORNING.
* THURSDAY THROUGH SUNDAY...DRY/VFR.
&&
.MARINE...
312 PM CDT
A WEAK LOW IS OVER SOUTHERN WISCONSIN AND IT WILL MOVE OVER THE LAKE
TONIGHT REACHING THE EASTERN GREAT LAKES BY MORNING BEFORE
DISSIPATING. WINDS WILL TURN NORTHEAST AND DIMINISH TO 10 KT OR
LESS BEHIND THE LOW. A LOW FORMS OVER THE CENTRAL PLAINS TONIGHT
AND WINDS VEER TO S TO SE AHEAD OF IT TOMORROW. S TO SW WINDS
INCREASE TO 20 KT TUESDAY NIGHT AND THEN BECOME W TO NW BEHIND THE
LOW WEDNESDAY MORNING. A HIGH FORMS OVER THE PLAINS WEDNESDAY AND
THEN MOVES OVER THE LAKE THURSDAY. WINDS BECOME LIGHT UNDER THE
HIGH AND THEN TURN S TO SE ON THE BACKSIDE OF THE HIGH FRIDAY
NIGHT. WHILE THE CENTER OF THE HIGH SHIFTS OVER NEW ENGLAND
SATURDAY...THE LAKE WILL STILL HAVE S TO SE FLOW THROUGH THE END OF
THE WEEKEND.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
418 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FOG WITH REDUCED VIS OF 4SM-6SM DEVELOPING EARLY THIS MORNING.
* SHOWERS WITH POSSIBLE TS REDEVELOPING LATER THIS MORNING AND
CONTINUING THROUGH LATE MORNING.
* REDEVELOPMENT OF SHOWERS/TS ONCE AGAIN LATER THIS AFTERNOON.
* MORE WIDESPREAD SHOWERS/TS EXPECTED TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT.
* COMPLEX WIND FORECAST WITH VARIABLE/LIGHT WINDS BECOMING
NORTHEAST LATER THIS MORNING...THEN SHIFTING MORE SOUTHERLY
LATER THIS AFTERNOON AND EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
A VERY COMPLEX FORECAST PERIOD FOR THE TERMINALS OVER THE NEXT 24
HOURS AS VARYING WEATHER CONDITIONS AT MULTIPLE TIMES COULD HAVE
IMPACTS ON THE TERMINALS. IN THE NEAR TERM...THE SHOWERS/TS WHICH
HAD DEVELOPED ACROSS NORTHEAST ILLINOIS AND OVER SOUTHERN LAKE
MICHIGAN HAVE SINCE DIMINISHED EARLY THIS MORNING...AND THINK ANY
FURTHER DEVELOPMENT SHOULD REMAIN VERY ISOLATED AND BRIEF OUTSIDE
OF THE TERMINALS. WITH EXPECTED CLEARING...LIGHT WINDS AND A VERY
MOIST ENVIRONMENT SHOULD SUPPORT FOG DEVELOPMENT OVER THE
TERMINALS THIS MORNING WITH VIS RESTRICTION EXPECTED. OUTSIDE OF
THIS DEVELOPMENT...A LIGHT NORTHERLY WIND OVER THE LAKE WITH LOW
CEILINGS AND VIS FURTHER NORTH TOWARDS THE MIDDLE PART OF THE LAKE
RAISES SOME CONCERNS FOR POTENTIAL LOWER CEILINGS AND FOG TO MOVE
ACROSS THE TERMINALS NEAR THE LAKE...ORD/MDW/GYY. EVEN IF THE
CLOUDS/FOG TO THE NORTH DONT QUITE MAKE IT THIS FAR SOUTH...COOLER
AIR MOVING INTO A VERY MOIST ENVIRONMENT COULD SUPPORT LOW
CLOUD/FOG DEVELOPMENT NEAR THE LAKE SHORE ANYWAYS. CONFIDENCE IS
LOW WITH REGARDS TO THE POTENTIAL BUT WILL NEED TO MONITOR THIS
AND ADJUST AS NEEDED.
EXPECT REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING AS ANOTHER
MID LEVEL DISTURBANCE APPROACHES FROM THE WEST...WITH THIS
SCATTERED DEVELOPMENT POSSIBLY CONTINUING THROUGH MID DAY.
ALTHOUGH SHOULD SEE A DIMINISHING TREND INTO THE EARLY
AFTERNOON...REDEVELOPMENT IN AND AROUND THE TERMINALS WILL ONCE
AGAIN BE POSSIBLE LATE THIS AFTERNOON THROUGH THE EARLY EVENING.
MORE WIDESPREAD SHOWERS/THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS
THE TERMINALS LATE THIS EVENING AND OVERNIGHT BEFORE EXITING EARLY
WEDNESDAY MORNING.
THE WIND FORECAST IS RATHER COMPLEX AS A WEAK GRADIENT WITH
SEVERAL BOUNDARIES MOVING ACROSS THE AREA ARE IN PLACE. WITH THESE
FEATURES IN PLACE...WIND DIRECTION AND SPEED WILL LIKELY RANGE
SUBSTANTIALLY FROM TERMINAL TO THE OTHER. LIGHT AND VARIABLE WINDS
FOR ALL OF THE TERMINALS EARLY THIS MORNING WILL PICK UP LATER
THIS MORNING WITH RFD THE ONLY SITE OBSERVING A MORE SOUTHERLY
DIRECTION EARLY ON. THE OTHER SITES SHOULD HOLD ONTO A NORTHEAST
DIRECTION LATER THIS MORNING...LIGHT AT FIRST BUT PICKING UP IN
SPEEDS. THEN AS THE GRADIENT TIGHTENS OUT AHEAD OF AN APPROACHING
SYSTEM...DO EXPECT A TRANSITION TO MORE OF A SOUTHERLY DIRECTION
TO OCCUR LATER THIS AFTERNOON AND THEN CONTINUE INTO THE EVENING
HOURS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE WITH FOG/REDUCED VIS.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWERS/TS THIS AFTERNOON.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS EVENING/OVERNIGHT.
* LOW/MEDIUM CONFIDENCE ON WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
* WEDNESDAY...CHANCE OF TSRA...MAINLY IN THE MORNING.
* THURSDAY THROUGH SUNDAY...DRY/VFR.
&&
.MARINE...
312 PM CDT
A WEAK LOW IS OVER SOUTHERN WISCONSIN AND IT WILL MOVE OVER THE LAKE
TONIGHT REACHING THE EASTERN GREAT LAKES BY MORNING BEFORE
DISSIPATING. WINDS WILL TURN NORTHEAST AND DIMINISH TO 10 KT OR
LESS BEHIND THE LOW. A LOW FORMS OVER THE CENTRAL PLAINS TONIGHT
AND WINDS VEER TO S TO SE AHEAD OF IT TOMORROW. S TO SW WINDS
INCREASE TO 20 KT TUESDAY NIGHT AND THEN BECOME W TO NW BEHIND THE
LOW WEDNESDAY MORNING. A HIGH FORMS OVER THE PLAINS WEDNESDAY AND
THEN MOVES OVER THE LAKE THURSDAY. WINDS BECOME LIGHT UNDER THE
HIGH AND THEN TURN S TO SE ON THE BACKSIDE OF THE HIGH FRIDAY
NIGHT. WHILE THE CENTER OF THE HIGH SHIFTS OVER NEW ENGLAND
SATURDAY...THE LAKE WILL STILL HAVE S TO SE FLOW THROUGH THE END OF
THE WEEKEND.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
THE REMAINDER OF THE DISCUSSION WILL BE ISSUED SHORTLY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* FOG WITH REDUCED VIS OF 4SM-6SM DEVELOPING EARLY THIS MORNING.
* SHOWERS WITH POSSIBLE TS REDEVELOPING LATER THIS MORNING AND
CONTINUING THROUGH LATE MORNING.
* REDEVELOPMENT OF SHOWERS/TS ONCE AGAIN LATER THIS AFTERNOON.
* MORE WIDESPREAD SHOWERS/TS EXPECTED TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT.
* COMPLEX WIND FORECAST WITH VARIABLE/LIGHT WINDS BECOMING
NORTHEAST LATER THIS MORNING...THEN SHIFTING MORE SOUTHERLY
LATER THIS AFTERNOON AND EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
A VERY COMPLEX FORECAST PERIOD FOR THE TERMINALS OVER THE NEXT 24
HOURS AS VARYING WEATHER CONDITIONS AT MULTIPLE TIMES COULD HAVE
IMPACTS ON THE TERMINALS. IN THE NEAR TERM...THE SHOWERS/TS WHICH
HAD DEVELOPED ACROSS NORTHEAST ILLINOIS AND OVER SOUTHERN LAKE
MICHIGAN HAVE SINCE DIMINISHED EARLY THIS MORNING...AND THINK ANY
FURTHER DEVELOPMENT SHOULD REMAIN VERY ISOLATED AND BRIEF OUTSIDE
OF THE TERMINALS. WITH EXPECTED CLEARING...LIGHT WINDS AND A VERY
MOIST ENVIRONMENT SHOULD SUPPORT FOG DEVELOPMENT OVER THE
TERMINALS THIS MORNING WITH VIS RESTRICTION EXPECTED. OUTSIDE OF
THIS DEVELOPMENT...A LIGHT NORTHERLY WIND OVER THE LAKE WITH LOW
CEILINGS AND VIS FURTHER NORTH TOWARDS THE MIDDLE PART OF THE LAKE
RAISES SOME CONCERNS FOR POTENTIAL LOWER CEILINGS AND FOG TO MOVE
ACROSS THE TERMINALS NEAR THE LAKE...ORD/MDW/GYY. EVEN IF THE
CLOUDS/FOG TO THE NORTH DONT QUITE MAKE IT THIS FAR SOUTH...COOLER
AIR MOVING INTO A VERY MOIST ENVIRONMENT COULD SUPPORT LOW
CLOUD/FOG DEVELOPMENT NEAR THE LAKE SHORE ANYWAYS. CONFIDENCE IS
LOW WITH REGARDS TO THE POTENTIAL BUT WILL NEED TO MONITOR THIS
AND ADJUST AS NEEDED.
EXPECT REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING AS ANOTHER
MID LEVEL DISTURBANCE APPROACHES FROM THE WEST...WITH THIS
SCATTERED DEVELOPMENT POSSIBLY CONTINUING THROUGH MID DAY.
ALTHOUGH SHOULD SEE A DIMINISHING TREND INTO THE EARLY
AFTERNOON...REDEVELOPMENT IN AND AROUND THE TERMINALS WILL ONCE
AGAIN BE POSSIBLE LATE THIS AFTERNOON THROUGH THE EARLY EVENING.
MORE WIDESPREAD SHOWERS/THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS
THE TERMINALS LATE THIS EVENING AND OVERNIGHT BEFORE EXITING EARLY
WEDNESDAY MORNING.
THE WIND FORECAST IS RATHER COMPLEX AS A WEAK GRADIENT WITH
SEVERAL BOUNDARIES MOVING ACROSS THE AREA ARE IN PLACE. WITH THESE
FEATURES IN PLACE...WIND DIRECTION AND SPEED WILL LIKELY RANGE
SUBSTANTIALLY FROM TERMINAL TO THE OTHER. LIGHT AND VARIABLE WINDS
FOR ALL OF THE TERMINALS EARLY THIS MORNING WILL PICK UP LATER
THIS MORNING WITH RFD THE ONLY SITE OBSERVING A MORE SOUTHERLY
DIRECTION EARLY ON. THE OTHER SITES SHOULD HOLD ONTO A NORTHEAST
DIRECTION LATER THIS MORNING...LIGHT AT FIRST BUT PICKING UP IN
SPEEDS. THEN AS THE GRADIENT TIGHTENS OUT AHEAD OF AN APPROACHING
SYSTEM...DO EXPECT A TRANSITION TO MORE OF A SOUTHERLY DIRECTION
TO OCCUR LATER THIS AFTERNOON AND THEN CONTINUE INTO THE EVENING
HOURS.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE WITH FOG/REDUCED VIS.
* LOW MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWERS/TS THIS AFTERNOON.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS EVENING/OVERNIGHT.
* LOW/MEDIUM CONFIDENCE ON WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
* WEDNESDAY...CHANCE OF TSRA...MAINLY IN THE MORNING.
* THURSDAY THROUGH SUNDAY...DRY/VFR.
&&
.MARINE...
312 PM CDT
A WEAK LOW IS OVER SOUTHERN WISCONSIN AND IT WILL MOVE OVER THE LAKE
TONIGHT REACHING THE EASTERN GREAT LAKES BY MORNING BEFORE
DISSIPATING. WINDS WILL TURN NORTHEAST AND DIMINISH TO 10 KT OR
LESS BEHIND THE LOW. A LOW FORMS OVER THE CENTRAL PLAINS TONIGHT
AND WINDS VEER TO S TO SE AHEAD OF IT TOMORROW. S TO SW WINDS
INCREASE TO 20 KT TUESDAY NIGHT AND THEN BECOME W TO NW BEHIND THE
LOW WEDNESDAY MORNING. A HIGH FORMS OVER THE PLAINS WEDNESDAY AND
THEN MOVES OVER THE LAKE THURSDAY. WINDS BECOME LIGHT UNDER THE
HIGH AND THEN TURN S TO SE ON THE BACKSIDE OF THE HIGH FRIDAY
NIGHT. WHILE THE CENTER OF THE HIGH SHIFTS OVER NEW ENGLAND
SATURDAY...THE LAKE WILL STILL HAVE S TO SE FLOW THROUGH THE END OF
THE WEEKEND.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
148 AM EDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 651 PM EDT MON JUL 8 2013
SHOWER AND THUNDERSTORM COVERAGE WILL INCREASE THROUGH THE EVENING
AND INTO THE OVERNIGHT HOURS TONIGHT WITH LOW TEMPERATURES IN THE
LOW 70S. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN ON
TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. A FEW OF THE
THUNDERSTORMS COULD BE STRONG TO SEVERE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
COMPLICATED FCST PERIOD WRT CONVECTIVE POTENTIAL THIS EVENING AND
AGAIN ON TUESDAY.
AREA OF SHOWERS AND THUNDERSTORMS THAT DEVELOPED THIS MORNING ACROSS
NE IL HAVE ADVECTED INTO THE NW CWA THIS AFTERNOON. THIS AREA OF
SHOWERS APPEARS TO BE IN A DECAYING STATE...AND HAS WORKED OVER THE
ENVIRONMENT ACROSS MUCH OF THE AREA. THE DEGREE OF RECOVERY LATE
THIS AFTERNOON AND EARLY THIS EVENING WILL BE CRITICAL TO ANY
CONVECTIVE POTENTIAL GOING FORWARD INTO THE OVERNIGHT.
HI RES MODELS HAVE DONE A POOR JOB WITH THE CONVECTIVE EVOLUTION
OVER THE PAST 6 HOURS. HRRR AND 12Z SPC 4KM RUNS HAVE INDICATED A
W-E ORIENTED LINE OF CONVECTION DEVELOPING ACROSS THE LOWER GREAT
LAKES REGION AND SINKING SOUTHWARD ACROSS THE AREA...COINCIDENT WITH
SHORTWAVE ENERGY ADVECTING SOUTHEAST ACROSS THE LOWER GREAT LAKES
PER W/V. THE COVERAGE AND EXTENT OF THIS POTENTIAL CONVECTION WILL
BE HIGHLY DEPENDENT ON ATMOSPHERIC RECOVERY. RECENT RAP13 RUNS DO
INDICATED A STRONG LOW LVL THETA E POOLING ACROSS NRN IL...ADVECTING
INTO NRN IN THROUGH 00Z. THIS OPTIMISTIC SCENARIO WOULD ALLOW
MLCAPES TO RECOVER TO 1000-2000 J/KG. MODEST 0-6 KM BULK SHEAR
VALUES OF 25-30 KTS...AND 850-500 MB LAPSE RATES OF 5.5-6 C/KM WILL
KEEP SEVERE POTENTIAL LOW TO MARGINAL AT THIS POINT....HOWEVER AN
ISOLATED STORM PRODUCING STRONG TO SEVERE WIND GUSTS IS POSSIBLE.
GIVEN ALL OF THESE FACTORS...DECIDED TO LEAVE POPS IN THE SCATTERED
CATEGORY TONIGHT...WITH THE BEST POTENTIAL FOR CONVECTION BETWEEN
22Z AND 04Z.
CONVECTIVE OUTFLOW SHOULD PUSH PRECIP POTENTIAL SOUTHWARD THROUGH
THE OVERNIGHT HOURS...AND HAVE CONFINED SLIGHT CHANCE POPS TO THE
SOUTH. WARM AND MUGGY CONDITIONS ARE EXPECTED AGAIN ON TUESDAY WITH
HIGHS TOPPING OUT IN THE MID TO UPPER 80S...WITH HEAT INDICES IN THE
LOW TO MID 90S. REMNANT CONVECTIVE BOUNDARY MAY BE A FOCUS FOR
SHOWER AND THUNDERSTORM ACTIVITY TOMORROW WITH A JUICED ENVIRONMENT.
UPSTREAM SHORTWAVE EXPECTED TO ADVECT INTO THE REGION LATE TUESDAY
AFTERNOON...WHICH WILL PROVIDE MORE SUPPORT FOR CONVECTION. GIVEN
UNCERTAINTY WITH EVOLUTION OF CONVECTION THIS EVENING...AND
RESULTING BOUNDARY LOCATION...AS WELL AS UNCERTAINTY WITH THE
EVOLUTION OF CONVECTIVELY INDUCED SHORTWAVE...HAVE OPTED TO KEEP
POPS IN THE CHANCE RANGE...WITH THE HIGHEST IN THE AFTERNOON.
POTENTIAL FOR SEVERE WIND GUSTS TOMORROW DOES EXIST GIVEN HIGHLY
UNSTABLE ENVIRONMENT...BUT MODEST BULK SHEAR VALUES OF 25-30 KTS MAY
BE A LIMITING FACTOR FOR STORM ORGANIZATION.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM EDT MON JUL 8 2013
SHARPENING MID LVL TROUGH SWEEPING THROUGH SRN CANADA SHRT TERM WILL
PROPEL A VIGOROUS CDFNT THROUGH CWA ON WED. IN LIGHT OF DISPARATE
MODEL GUIDANCE WILL GENERALLY RELY ON HIGHRES CONSENSUS OF FASTER
FROPA ESP WITHIN GUISE OF TUE NIGHT CONVN/MCS AND LIKELY OUTFLW
REMNANT COMPOSITING MORE EFFECTIVE DY3 FORCING MECHANISM SWD TWD
THE OH VALLEY. AS SUCH HAVE SHARPLY CURTAILED POPS ON WED.
AFT THAT...HIGH PRES TO RIDGE SWD ACRS THE LAKES AS MID LVL TROUGH
AMPLIFIES THROUGH NEW ENGLAND BRINGING SEASONABLE TEMPS TO THE
REGION AND DRY WX.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 140 AM EDT TUE JUL 9 2013
POINT/AIRFIELD CHANCES FOR CONVECTION EXIST...THOUGH TOO LOW TO
WARRANT ANY INCLUSION ATTM. BEST FOCUS ASSOCD WITH APPROACH OF NRN
STREAM WAVE LATE IN FORECAST PD AND ADDRESS WITH TEMPO TSRA AT
KSBN...HEAVY RAFL POTENTIAL GIVEN WARM/MOIST TROPOSPHERE DEPTH
SUGGESTS AT LEAST BRIEF IFR VSBYS REDUCTIONS WITHIN/NEAR
CONVECTIVE CELL CORES. TIMING APPEARS JUST OUTSIDE OF CURRENT
FORECAST WINDOW AT KFWA...TO BE INCLUDED WITH 12 UTC ITERATION.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...BENTLEY
SHORT TERM...NG
LONG TERM...T
AVIATION...MURPHY
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
401 AM CDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 9 2013
06Z MSAS SFC ANALYSIS SUPPORTIVE OF WEAK LOW OVER CENTRAL SD WITH
STATIONARY FRONT EXTENDING SEWD FROM THE LOW AND BISECTING
EASTERN IA AND NORTHWEST IL. MOISTURE IS POOLING ALONG THE FRONT
WITH DEWPTS OF 70-75F. 00Z KDVN RAOB SHOWS DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES OF NEARLY 2 INCHES... WHICH IS AROUND 160
PERCENT OF NORMAL AND NEARLY 2 STANDARD DEVIATIONS ABOVE THE MEAN.
CONVECTIVELY ENHANCED VORT MAX IS TRACKING THROUGH EASTERN NE ATTM
WITH RADARS SHOWING SHOWERS AND STORMS AHEAD OF THIS FEATURE INTO
WESTERN IA. ADDITIONAL COMPLEX OF STORMS WAS OVER THE DAKOTAS
AHEAD OF COLD FRONT AND SHORTWAVE MOVING EAST THROUGH FAR SOUTHERN
ALBERTA PROVINCE AND NORTHERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 9 2013
SUGGESTIONS OF 2 MAIN ROUNDS OF STORMS THROUGH THE PERIOD. AS
CONVECTIVELY ENHANCED VORT MAX MOVES EAST FROM NE ANTICIPATE
SHOWERS AND STORMS TRACKING AHEAD OF THIS FEATURE TO MOVE ACROSS
THE REGION BY MID AM THROUGH EARLY AFTN. PRIOR TO THE ARRIVAL
OF THESE STORMS COULD SEE ADDITIONAL DEVELOPMENT PRIOR TO MID AM
OVER THE AREA WITH WARM ADVECTION WING. POTENTIAL FOR SOME
STRENGTHENING OF MID LEVEL WINDS AND INTENSIFICATION OF STORMS
BY LATE AM AND AFTN FOR RISK OF FEW STRONG TO ISOLD SEVERE STORMS
WITH MOST RECENT RUNS OF HRRR 2-5KM UPDRAFT HELICITY AND 3 KM
VELOCITY CONTINUING TO SUGGEST THIS RISK NEAR AND ESPECIALLY NORTH
OF I-80. MAY SEE BREAK IN ACTION OR RELATIVE LULL IN ACTIVITY
BY MID-LATE AFTN WITH FOCUS SHIFTING BACK NORTHWEST FOR DEVELOPMENT
AHEAD OF COLD FRONT. LIKELY TO SEE ANOTHER ROUND OF STORMS MOVE
THROUGH THIS EVENING INTO OVERNIGHT AHEAD OF COLD FRONT.
STRENGTHENING 40-60 KT MID LEVEL SPEED MAX SPREADING BEHIND FRONT
COUPLED WITH VERY UNSTABLE ENVIRONMENT WILL SUPPORT RISK OF SEVERE
STORMS WITH POTENTIAL FOR UPSCALE GROWTH TO LINEAR MCS WITH MAINLY
DAMAGING WIND THREAT. HEAVY RAIN WILL BE A CONCERN AS WELL GIVEN
THE DEEP ALMOST TROPICAL MOISTURE IN PLACE. STORMS SHOULD BE MOVING
ALONG MORE THAN WE/VE SEEN OF LATE BUT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH RATES LIKELY 1-2"/HR. THUS... CANT RULE OUT SOME
LOCALIZED FLASH FLOODING AND WILL HAVE TO BE ESPECIALLY WATCHFULL
OVER PORTIONS OF DELAWARE AND DUBUQUE COUNTIES WHICH HAVE SEEN 2-5
INCHES PAST 24-36 HRS. EXPECT PCPN SHOULD BE DIMINISHING FROM NW
TO SE OVRNGT WITH PASSAGE OF COLD FRONT.
HIGHS TDY TRICKY WITH CLOUDS AND PCPN BUT OVERALL SHOULD RANGE FROM
MID 80S TO THE LOWER 90S. SOME MIXING OUT OF DEWPTS MAY OCCUR BUT
AT LEAST UPPER 60S TO LOWER 70S EXPECTED ON DEWPTS... WHICH COMBINED
WITH TEMPS WILL MAKE FOR HEAT INDICES MAINLY IN THE MID TO UPPER 90S.
COOLER AND DRIER AIR LAGS BEHIND FRONT TNGT... THUS LOWS ONLY DROP
INTO THE UPPER 60S TO LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUL 9 2013
WEDNESDAY AND THURSDAY...AS L/W TROF CONTINUES TO DEEPEN AND
ESTABLISH ACRS THE GRT LKS...SEASONABLY STRONG LLVL HIGH PRESSURE
WILL LOOK TO DUMP DOWN THE NORTHERN PLAINS AND MO RVR VALLEY ON WED.
A FEW POST-FRONTAL SHOWERS AND STORMS MAY BE OCCURRING ACRS THE FAR
EASTERN/SOUTHERN CWA WED MORNING BUT BULK OF THE ACTIVITY SHOULD BE
GONE BY 15Z. VEERING AND INCREASING BOUNDARY LAYER FLOW AS WELL AS
INCOMING SUBSIDENCE SHOULD CLEAR THINGS OUT ON WED...BUT SOME LAG IN
CAA TO ALLOW TEMPS TO WARM INTO THE LOW TO MID 80S EVEN POST-
FRONTALLY. A RATHER BREEZY NORTHWEST TO NORTH WIND OF 15-20 MPH.
CLEAR SKIES AND WIND DROP OFF WED NIGHT TO ALLOW SOME AREA TEMPS TO
DROP OFF INTO THE 50S. LLVL HIGH PRESSURE CONTINUING TO MIGRATE
EASTWARD ACRS THE REGION TO MAKE FOR A CHAMBER OF COMMERCE DAY THU
WITH HIGHS IN THE UPPER 70S TO LOWER 80S...SUNSHINE AND LOWER
HUMIDITY. THU NIGHT SEASONABLY COOL AGAIN WITH LOWS IN THE 50S AND
LOW 60S.
FRIDAY THROUGH NEXT MONDAY...TRENDS OF THE LATEST RUN 00Z MEDIUM
RANGE SOLUTIONS AND ENSEMBLES SUGGEST SOME DIGGING TROFFINESS IN THE
PACIFIC NORTHWEST/WESTERN CANADA TO TRANSLATE INTO PUMPED UP UPPER
RIDGING ACRS THE MID CONUS FRI INTO SAT. THUS WHILE THERMAL DOME
INTENSIFIES ACRS THE GRT BSN INTO THE SOUTHWESTERN PLAINS...MCS
TRACK/RING OF FIRE PATTERN TO ESTABLISH IN NORMAL DEEP SUMMER
LOCATION OF NORTHWESTERN HIGH PLAINS...UPPER MS RVR VALLEY...SOUTHERN
CANADA AND INTO THE GRT LKS. LATEST INDICATIONS SUGGEST A LESSENING
CHANCE FOR SOME OF THIS MCS ACTIVITY TO SPILL DOWN ACRS THE
NORTHERN CWA EITHER FRI NIGHT OR SAT NIGHT WHILE TEMPERATURES START
TO REBOUND BACK TO NORMAL OR EVEN WARMER. BY SUNDAY...WESTERLIES
FIRMLY ESTABLISH ACRS THE U.S.-CANADIAN BORDER REGION WITH UPPER
RIDGING DOMINATING ACRS THE SOUTHERN 2/3S OF THE CONUS. LONGER
RANGE THERMAL PROFILES SUGGEST ENOUGH AIRMASS MODIFICATION TO DRIVE
SUNDAY HIGHS UP INTO AT LEAST THE LOWER 90S ALONG WITH INCREASING
SFC DPTS/HUMIDITY. PASSING WAVE IN THIS PROGRESSIVE FLOW MAY TRY TO
SHUNT DOWN A WEAKENING SFC BOUNDARY DOWN TOWARD OR ACRS THE CWA
LATER SUNDAY NIGHT OR MONDAY AND GET SLOWED AS IT ALIGNS PARALLEL TO
MEAN STEERING FLOW. THUS THIS WINDOW MAY BE THE NEXT REAL CHANCE FOR
SOME PRECIP IN THE AREA AFTER TODAY/TONIGHT. LONGER RANGE SIGNALS ON
THE LATEST RUNS ESPECIALLY THE NEW 00Z ECMWF SUGGESTS THAT THIS
BROAD UPPER RIDGING PATTERN TO CONTINUE TO REIGN ACRS MUCH OF THE
CONUS WELL INTO MID NEXT WEEK...WHILE THE TROPICS CONTINUE TO GET
INTERESTING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON JUL 8 2013
LIGHT WINDS AND SUMMER HUMIDITY WILL LIKELY LEAD TO FOG
DEVELOPMENT TONIGHT AND FOR NOW WILL ANTICIPATE MID LEVEL CLOUD
COVER TO PREVENT VISIBILITIES FROM DROPPING ANY LOWER THAN 4 OR 5
MILES LATE TONIGHT. THERE REMAINS A CHANCE FOR ISOLATED TO WIDELY
SCATTERED THUNDERSTORMS TONIGHT THROUGH TUESDAY NIGHT. THE BEST
CHANCES WILL BE CENTERED ALONG AND AHEAD OF A COLD FRONT THAT WILL
DROP THROUGH THE AREA TUESDAY EVENING. AHEAD OF THIS...HAVE GONE
WITH LOW CONFIDENCE PROB30 OR VCTS WORDING TO COVER THE
POTENTIAL. WINDS WILL BE LIGHT AND PRIMARILY FROM THE SOUTH TO
SOUTHWEST THROUGHOUT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A SERIES OF UPPER DISTURBANCES WILL IMPACT THE MID-ATLANTIC REGION
INTO THURSDAY WHILE BERMUDA HIGH PRESSURE PERSISTS OFFSHORE. A COLD
FRONT IS EXPECTED TO MOVE ACROSS THE CENTRAL MID-ATLANTIC FROM THE
WEST LATE THURSDAY INTO FRIDAY BEFORE STALLING OVER THE SOUTHERN
MID-ATLANTIC FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
BERMUDA HIGH REMAINS ANCHORED OVER THE WESTERN ATLANTIC THROUGH
TONIGHT. MID-ATLANTIC REMAINS IN A WESTERLY FLOW ALOFT...WITH
EMBEDDED SHORTWAVES EXPECTED TO AFFECT THE CWA.
RADAR SHOWS ONE AREA OF SHOWERS ACROSS SOUTHWEST PENNSYLVANIA AND
NORTHERN WEST VIRGINIA PRESSING EAST-SOUTHEAST EARLY THIS MORNING.
BASED ON RADAR TRENDS EXPECT THIS LEADING WAVE OF SHOWERS TO AFFECT
LOCATIONS WEST OF THE BLUE RIDGE. THERE IS SOME UNCERTAINTY HOW FAR
EAST THE INITIAL AREA OF SHOWERS MAKES IT BEFORE POSSIBLY
DIMINISHING. HRRR GUIDANCE SUGGESTS THIS LEADING WAVE OF SHOWERS
WEAKENS OVER THE NEXT SEVERAL HOURS...SO LOWER POPS EXIST FURTHER
DOWNSTREAM.
HOWEVER EVEN IF THE LEADING WAVE OF SHOWERS DISSIPATES...SHORTWAVE
OVER OHIO IS FORECAST TO MOVE EAST INTO THE MID-ATLANTIC FOR THIS
AFTERNOON WHICH WILL SUPPORT SOME SHOWERS AND THUNDERSTORMS ACROSS
THE ENTIRE CWA BY THAT TIME.
WITH MORNING CLOUD COVER THIS WILL LIMIT DESTABILIZATION THIS
AFTERNOON. SIMILAR TO YESTERDAY NAM SHOWS MORE CAPE THAN THE
GFS...AND WAS THE BETTER CHOICE. STILL...NAM ONLY EXHIBITS ABOUT
1000 J/KG THIS AFTERNOON ALONG WITH WEAK SHEAR. THEREFORE...AM NOT
EXPECTING ORGANIZED SEVERE CONVECTION BUT LOCALLY STRONGER STORMS
WITH GUSTY WINDS/HEAVY DOWNPOURS CAN/T BE RULED OUT.
MUCH OF THE CONVECTION SHOULD DISSIPATE BY EARLY EVENING AS THE
SHORTWAVE EXITS AND THE SUN SETS. WILL CONTINUE POPS FOR SHOWERS
ACROSS THE NORTHWEST PORTION OF THE CWA HOWEVER AS ANOTHER SHORTWAVE
APPROACHES. FOG PRONE AREAS COULD SEE PATCHY FOG AS
WELL...PARTICULARLY IF SOME CLEARING OCCURS.
MET GUIDANCE PERFORMED BETTER THAN MAV GUIDANCE FOR MAXIMA
YESTERDAY. IT CONTINUES TO BE THE LOWER SET OF GUIDANCE...AND WITH
PLENTY OF CLOUDS TODAY WILL LEAN IN THAT DIRECTION WITH A SLIGHT
UPWARD ADJUSTMENT 1-2 DEG /BUT STILL BELOW MAV/. USED AN EQUAL BLEND
OF BIAS CORRECTED MET/MAV FOR MINIMA.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
WEDNESDAY...A SHORT-WAVE TROUGH SWINGS EAST THROUGH THE MID-ATLANTIC
THROUGH THE DAY. WITH THE BERMUDA HIGH PUMPING TROPICAL MOISTURE
INTO THE REGION...EXPECT DEWPOINTS IN THE LOW 70S AND PWATS OF 2.0
TO 2.2 INCHES WHICH IS NEAR TWO STANDARD DEVIATIONS ABOVE NORMAL.
WITH A FOCUS OF FORCING FROM THE TROUGH AXIS...THERE IS THE
POTENTIAL FOR SEVERE THUNDERSTORMS AND FLASH FLOODING ACROSS THE
AREA. WILL ADD MENTION OF BOTH TO THE HWO. WITH BULK SHEAR LESS THAN
25 KT... FLASH FLOODING SHOULD BE THE GREATEST THREAT. CLOUD COVER
MAY LIMIT MAX TEMPS...WENT WITH A MAV/MET BLEND THAT LEANS TOWARD
MAV...GENERALLY UPR 80S WITH LOW 90S POSSIBLE IN BALT-WASH URBAN
CORRIDOR.
WEDNESDAY NIGHT...INSTABILITY REMAINS THROUGH THE NIGHT WITH AT
LEAST ISOLATED ONGOING OR REDEVELOPING THUNDERSTORMS. MIN TEMPS HIGH
WITH CLOUDS AND MOISTURE...GENERALLY LOW TO MID 70S PER MAV/MET/SREF
BLEND.
THURSDAY...COLD FRONT APPROACHES FROM THE WEST AS LONG WAVE TROUGH
AMPLIFIES AS IT MOVES ACROSS THE MIDWEST STATES. EXPECT MORE
WIDESPREAD THUNDERSTORM ACTIVITY THAN WED WITH THE FRONT
ENTERING THE POTOMAC HIGHLANDS LATE IN THE AFTERNOON. SLIGHTLY MORE
BULK SHEAR THAN WED AND THE FRONTAL FORCING SHOULD INCREASE THE
SEVERE THREAT. SIMILAR TO WED WITH MEX/GMOS BLEND SUGGESTING A
COUPLE DEGREES LESS.
THURSDAY NIGHT...COLD FRONT PUSHES SE THROUGH MOST OF THE CWA BEFORE
STALLING OVER SERN VA WHERE IT WILL PERSIST/UNDULATE THROUGH THE
WEEKEND. ONGOING THUNDERSTORMS WILL BE SHUNTED TO SERN PORTIONS OF
THE CWA...WHERE CHANCE POPS WERE MAINTAINED FOR THE LATE NIGHT. MIN
TEMPS LOW 60S IN THE POTOMAC HIGHLANDS...THEN MID TO UPR 60S WEST
FROM THE SHEN VLY PER MEX/SREF BLEND.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
COLD FRONT REMAINS STALLED OVER THE DELMARVA AND SERN VA THROUGH THE
WEEKEND. THE FRONT MAY RETROGRADE A BIT...RESULTING IN THUNDERSTORMS
INTO THE BALT-WASH METRO...PARTICULARLY FOR SUNDAY. OTW...EXPECT
DRIER CONDITIONS WITH SFC HIGH PRESSURE SHIFTING EAST ACROSS THE NRN
MID-ATLANTIC. TEMPS NEAR NORMAL WITH SOME SUNSHINE.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SHOWERS MAY REACH MRB EARLY THIS MORNING...BUT CONFIDENCE IS LOW ON
THIS INITIAL BATCH HOLDING TOGETHER AS FAR EAST AS THE HUBS.
SHORTWAVE MOVES THROUGH THIS AFTERNOON...WITH AT LEAST SHRA/TSRA AND
WILL CONSIDER INCLUSION OF VCTS/CB FOR THE NEXT TAF CYCLE.
ACTIVE WEATHER PATTERN FOR WED THROUGH THUR NIGHT WITH HEAVY
THUNDERSTORMS EXPECTED. IFR CONDS IN HEAVIEST ACTIVITY. GENERALLY
LIGHT SSWLY FLOW WED INTO THUR BEFORE A COLD FRONT MOVES THROUGH THE
TERMINALS LATE THURSDAY. COLD FRONT STALLS JUST SE OF DC METROS
FRIDAY INTO THE WEEKEND.
&&
.MARINE...
SOUTHERLY WINDS AROUND BERMUDA HIGH CONTINUES THROUGH TONIGHT.
SHOULD STAY BELOW SCA TODAY...BUT THIS EVENING AND INTO THE NIGHT
THERE IS A BETTER CHANCE OF HIGHER WINDS UP THE BAY ENHANCED BY
CHANNELLING AND WILL RAISE SCA.
SSWLY FLOW INCREASES THROUGH THE DAY WEDNESDAY. JUST THE LOWER SRN
MD PORTION OF THE BAY IN SCA WED MORNING...THEN TO ALL WATERS FOR
THE AFTERNOON THAT IS EXPECTED TO CONTINUE INTO THE EVENING. ACTIVE
WEATHER PATTERN WITH SPECIAL MARINE WARNINGS POSSIBLE UNTIL A COLD
FRONT MOVES THROUGH LATE THURSDAY NIGHT. COLD FRONT WILL STALL NEAR
THE WATERS THROUGH THE WEEKEND...POTENTIALLY CONTINUING THE ACTIVE
WEATHER PATTERN.
&&
.EQUIPMENT...
THE RIVER GAUGE AT FROV2 STILL IS REPORTING ERRONEOUS DATA. WE
HAVE TURNED OFF THE DATA STREAM FROM THIS GAUGE. USE DATA FROM
THIS SITE WITH EXTREME CAUTION. HWVR...THE BAD DATA HAS NOT BEEN
INGESTED INTO RIVER FCSTS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR ANZ531>533-539>541.
SMALL CRAFT ADVISORY FROM 2 PM TO 6 PM EDT WEDNESDAY FOR
ANZ530>533-535>542.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
WEDNESDAY FOR ANZ534-543.
&&
$$
SYNOPSIS...BPP/BAJ
NEAR TERM...BPP
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BPP/BAJ
MARINE...BPP/BAJ
EQUIPMENT...LWX
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
526 AM EDT TUE JUL 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 525 AM EDT TUE JUL 9 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS WITH SEVERAL UPSTREAM SHORTWAVE TROUGHS. THE MOST
PROMINENT SHRTWV WAS LOCATED OVER ERN MT WHILE A WEAKER IMPULSE AND
ASSOCIATED MCS WAS MOVING THROUGH ERN SD. AT THE SFC...A WEAK
FRONTAL BOUNDARY LINGERED ACROSS SRN WI WHILE A STRONGER COLD FRONT
AHEAD OF THE MT SHRTWV EXTENDED FROM NW ONTARIO INTO NRN ND. A WEAK
RIDGE EXTENDED FROM QUEBEC ACROSS LAKE SUPERIOR RESULTING IN
LIGHT/CALM WINDS OVERNIGHT. AREAS OF FOG...LOCALLY DENSE...HAS
DEVELOPED AS ABUNDANT LOW LEVEL MOISTURE LINGERED BELOW AN INVERSION
ABOVE 850 MB.
EXPECT THAT THE MORNING WILL BE DOMINATED BY LOW CLOUDS BUT WITH
DAYTIME HEATING/MIXING THE LOW CLOUDS ACROSS MOST OF THE AREA WILL
THIN OUT ENOUGH BY THIS AFTERNOON FOR TEMPERATURES TO CLIMB INTO THE
LOWER 80S INLAND. SATELLITE TRENDS...SHORTER TERM MODELS AND CAPE
GRADIENT...SUGGEST THAT THE ERN SD MCS WILL TRACK TO THE EAST INTO W
AND SRN WI.
THERE IS SOME UNCERTAINTY REGARDING THE IMPACTS OF THE MCS ON
CONVECTION DEVELOPING FARTHER TO THE NORTH. THE FORCING ASSOCIATED
WITH THE APPROACHING NRN PLAINS SHRTWV WITH 100M HEIGHT FALLS AND
MODERATE 700-300 QVECTOR CONV WILL ALSO BE STRONGEST TO THE NORTH OF
THE CWA. HOWEVER...THE SRN END OF THE SHRTWV SHOULD STILL BE STRONG
ENOUGH TO SUPPORT SCT SHRA/TSRA MOVING FROM NW WI INTO WRN UPPER MI
THIS AFTERNOON AND THROUGH THE REST OF THE CWA THIS EVENING.
EXPECTED MAX TEMPS AND DEWPOINTS INTO THE MID TO UPPER 60S GIVE CAPE
VALUES INTO THE 1K-2K J/KG RANGE...GREATEST WEST CENTRAL. 0-6KM BULK
SHEAR VALUES IN THE 30-35 KNOT RANGE WILL BE MARGINAL FOR STRONG/SVR
ORGANIZED CONVECTION BUT WITH TSRA MOVING THROUGH DURING PEAK
HEATING GIVING DCAPE VALUES IN THE 500-1000 J/KG RANGE...SOME
ISOLATED STRONG/DAMAGING WIND GUSTS MAY BE POSSIBLE WITH ANY
STRONGER STORMS. THE HIGHER PROBABILITIES FOR SVR STORMS REMAINS TO
THE SOUTH WHERE THE INSTABILITY IS GREATEST...PER SPC DAY1 OUTLOOK.
THE SHRA/TSRA ARE EXPECTED TO PROGRESS THROUGH THE AREA MOVING INTO
THE ERN CWA LATE THIS EVENING AND ENDING OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE JUL 9 2013
AFTER A FEW DAYS OF WARM AND ACTIVE WEATHER WITH POCKETS OF HEAVY
RAIN OVER MAINLY WESTERN HALF OF CWA...DEVELOPING TROUGHING ALOFT
ACROSS THE GREAT LAKES AND SFC HIGH ON THE WESTERN EDGE OF THE
TROUGH ALOFT WILL BRING QUIET AND COOLER WEATHER MID TO LATE WEEK.
WARMER TEMPERATURES AND INCREASING SHRA/TSRA CHANCES RETURN FOR THE
WEEKEND AS UPPER HEIGHTS BECOME MORE ZONAL.
OVERALL AGREEMENT THAT BEST CHANCE OF SHRA/TSRA ON WEDNESDAY WILL
BE 12-15Z OVER THE FAR EASTERN CWA. STRONGER TSRA STILL POSSIBLE
WITH MUCAPE UP TO 800J/KG. BETTER SHOT FOR SVR WILL BE FARTHER
SOUTH OVER SOUTHERN WI/NORTHERN IL CLOSER TO WEST-EAST FRONTAL
BOUNDARY AND ON NORTHERN GRADIENT OF HIGHER MLCAPES OVR 1000J/KG.
ANY CHANCES OF SHRA/TSRA OVER EAST QUICKLY END THROUGH MORNING AS
STRONG DEEP LAYER Q-VECTOR DIVERGENCE/SUBSIDENCE SURGES ACROSS
UPPER GREAT LAKES. PRESSURE GRADIENT BRIEFLY BECOMES TIGHT BTWN
THE EXITING LOW PRESSURE TROUGH AND HIGH PRESSURE BUILDING OVER
THE PLAINS. EXPECT BRIEF BUILDING WAVES AND INCREASED SWIM RISK
FOR WEDNESDAY OVER THE LK SUPERIOR BEACHES OF ALGER COUNTY AS
WINDS WILL BE FROM THE WEST TO NORTHWEST. WINDS/WAVES AND
ASSOCIATED HIGHER SWIM RISK SUBSIDES BY LATE AFTN WITH LOSS OF
PRESSURE RISES AND TIGHTER PRESSURE GRADIENT.
HIGH PRESSURE REMAINS MAIN WEATHER FEATURE FOR THU/FRI. TEMPS MAY
DROP INTO THE LOW-MID 40S OVER INTERIOR COOL SPOTS ON THURSDAY NIGHT
WITH LGT SOUTHERLY FLOW AS RIDGE AXIS DRIFTS ACROSS. AIRMASS DOES
NOT APPEAR TO BE NEARLY COLD OR DRY ENOUGH FOR ANY FROST POTENTIAL.
HIGH TEMPS BOTH DAYS SHOULD TOP OUT IN THE MID-UPR 70S AWAY FROM THE
GREAT LAKES. MAY EVEN SEE A FEW SPOTS BACK NEAR 80 DEGREES BY
THURSDAY.
UNCERTAINTY ABOUNDS WITH TIMING AND EXTENT OF NEXT ROUND AND/OR
ROUNDS OF SHRA/TSRA THIS WEEKEND INTO NEXT MONDAY. ECMWF NORMALLY
LEADS WAY IN TERMS OF VERIFICATION...BUT BOY ARE ITS SOLUTIONS IN
THE LAST COUPLE DAYS QUITE INCONSISTENT IN TERMS OF TIMING FOR THE
WEEKEND SHRA/TSRA CHANCES. DOES SEEM LIKE ECMWF IS TRENDING TOWARD
SLOWER IDEA SHOWN BY GFS FOR ARRIVAL OF PRECIP FRIDAY NIGHT. WILL
START TO SHOW TREND OF CHANCE POPS ONLY OVER THE FAR WEST LATE ON
FRIDAY NIGHT WHILE IT STAYS MAINLY DRY ELSEWHERE. UPPER HEIGHTS
FLATTEN OUT SATURDAY ALLOWING SHORTWAVES AND MID-LEVEL WIND MAX TO
SLIDE ACROSS UPPER GREAT LAKES REGION. MAIN SFC LOW WILL BE WELL TO
NORTH CLOSER TO SHARPER TROUGH ALOFT...BUT SW LOW-LEVEL FLOW ALONG
WITH INCREASING MOISTURE AND BUILDING INSTABILITY JUST UPSTREAM
SHOULD RESULT IN AT LEAST A CHANCE OF SHRA/TSRA AHEAD OF SFC-H85
TROUGH THAT MOVES THROUGH BY SUNDAY MORNING. WITH WRLY FLOW
ALOFT...FRONT MAY END UP STALLING OUT LATER IN THE WEEKEND PROVIDING
A FOCUS FOR ADDITIONAL SHRA/TSRA. FOR MOST PART USED CONSENSUS
POPS...BUT DID INCREASE POPS SLIGHTLY OVER THE SOUTH AND EAST CWA
CLOSER TO EXPECTED POSITION OF FRONT PER WPC HAND DRAWN SFC PROGS.
BASED ON GENERAL S/SW GRADIENT FLOW AHEAD OF FRONT AND H85 TEMPS IN
THE MID TEENS...INCREASED TEMPS OVER CONSENSUS GUIDANCE. EXPECT MAX
TEMPS FRIDAY THROUGH SUNDAY IN THE MID-UPR 70S TO AS WARM AS MID
80S. IT WILL ALL DEPEND ON EXTENT OF CLOUDS AND SHRA/TSRA. AFTER MIN
TEMPS IN THE 40S AND 50S MUCH OF THIS WEEK...READINGS RETURN TO THE
WARMER/MUGGIER 60S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 126 AM EDT TUE JUL 9 2013
EXPECT DENSE FOG/VLIFR CONDITIONS TO IMPACT ALL 3 TAF SITES EARLY
THIS MRNG WITH LGT WINDS/HUMID LLVLS UNDER SFC HI PRES/DRIER AIR ALF
DEPICTED ON THE 00Z GRB RAOB. DIURNAL HEATING LATER THIS MRNG SHOULD
ALLOW A GRADUAL RETURN OF VFR WX...FASTEST BY NOON AT IWD WITH DVLPG
DOWNSLOPE S WIND IN ADVANCE OF APRCHG UPR DISTURBANCE/COLD FNT. SOME
SHRA/TS IN ADVANCE OF THESE FEATURES WL ARRIVE OVER THE WRN IWD/CMX
SITES BY THE END OF THE TAF PERIOD AND THEN MOVE E TOWARD SAW DURING
THE EVNG. ALTHOUGH THE RELATIVE DRYNESS OF THE LLVLS SHOULD ALLOW
PREDOMINANT VFR CONDITIONS...POORER CONDITIONS WL BE PSBL UNDER THE
HEAVIER SHRA/TS. UPSLOPE WNW FLOW OFF LK SUP IN THE WAKE OF THE
CONVECTION MIGHT CAUSE PREDOMINANT MVFR WX AT CMX...ESPECIALLY IF
HEAVIER RA FALLS NEARBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON JUL 8 2013
DENSE FOG REMAINS A CONCERN ACROSS LAKE SUPERIOR THROUGH TUESDAY
MORNING. LIGHT WINDS AND LITTLE AIR MASS MOVEMENT WILL ALLOW FOR THE
REDEVELOPMENT OF AREAS OF DENSE FOG OVERNIGHT. CLEARING SKIES FOR
TUESDAY MORNING SHOULD ALLOW ENOUGH HEATING TO MIX OUT THE MOST
DENSE FOG BY TUESDAY AFTERNOON. PATCHY FOG WILL THEN LINGER INTO
WEDNESDAY BEFORE A COLD FRONT BRINGS DRIER AIR FROM WEST TO EAST
ACROSS THE LAKE. WINDS SHOULD BE LIGHT AND GENERALLY VARIABLE
THROUGH TUESDAY EVENING. THEN...EXPECT WINDS TO VEER TO THE NW AT 15
TO 25 KNOTS...MAINLY ACROSS THE EAST HALF OF THE LAKE...FOR LATE
TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE WILL THEN BUILD INTO
THE AREA THURSDAY THROUGH SATURDAY AND BRING LIGHT WINDS UNDER 15
KNOTS FOR MUCH OF THE TIME PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
412 AM CDT TUE JUL 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE JUL 9 2013
MAIN CONCERN IN THE SHORT TERM REVOLVES ON EVOLUTION OF STORMS
CURRENTLY ACROSS THE DAKOTAS THROUGH THE MORNING...FOLLOWED BY WHERE
THUNDERSTORMS REDEVELOP THIS AFTERNOON AND TRAVEL THIS EVENING. IT
IS THE AFTERNOON/EVENING ACTIVITY THAT WILL ALSO HAVE A SEVERE
THREAT. WIND AND HAIL WILL BE THE PRIMARY THREATS...THOUGH DEPENDING
ON WHERE BOUNDARIES ARE LEFT OVER FROM CONVECTION THIS
MORNING...THERE WILL ALSO BE THE SMALL CHANCE FOR TORNADOES ON ANY
LEFT OVER OUTFLOW BOUNDARIES.
AT 3 AM...WE WERE DEALING WITH A BIFURCATED LLJ IN TERMS OF MOISTURE
TRANSPORT MAXIMA...WITH ONE BRANCH DRIVING CONVECTION CURRENTLY
MOVING ACROSS THE DAKOTAS AND THE OTHER DRIVING ANOTHER CLUSTER
ALONG THE NEB/IA BORDER. THIS SRN BRANCH WILL TRACK ACROSS IA
THROUGH THE MORNING...KEEPING THAT CONVECTION SOUTH OF MN WHILE
BECOMING THE MAIN LLJ FOR POTENTIAL AFTERNOON ACTIVITY.
FOR THE MPX AREA...IT IS THE MCS THIS MORNING OVER SODAK THAT WILL
BE OUR PROBLEM. 3Z RAP MUCAPE ANALYSIS SHOWS A RIBBON OF 1000-1500
J/KG OF MUCAPE EXTENDING FROM THE MADISON/CANBY AREA...ESE TROUGH
ROCHESTER AND LA CROSSE. AS A RESULT...ANTICIPATE THIS BAND OF
THUNDERSTORMS WILL CONTINUE ESE ALONG THIS CAPE GRADIENT. AT ITS
CURRENT PACE...SHOULD ENTER WRN MN SHORTLY BEFORE 5 AM...REACH THE
I-35 CORRIDOR BETWEEN 7 AND 8 AM AND EVENTUALLY THE LSE/EAU AREAS BY
LATE MORNING. THE BULK OF THE CONVECTION WITH THIS LINE SHOULD TRACK
SOUTH OF I-94 THIS MORNING. AS FOR SEVERE THREAT...THE STRONG/SEVERE
LINE OF STORMS THAT MOVED ACROSS SODAK HAS NOW MERGED WITH THE WAA
ACTIVITY THAT HAD DEVELOPED OUT AHEAD OF IT...WITH ONE LINE NOW
EVIDENT ON REGIONAL RADAR ANALYSIS. WILL HAVE TO WATCH HOW THIS LINE
EVOLVES OVER THE NEXT HOUR TO SEE WHAT KIND OF SEVERE THREAT IT WILL
POSE. IN THE NEXT HOUR...IF IT BEGINS TO BOW OUT AND
ACCELERATE...THEN A WIND THREAT WILL EXIST THROUGH THE MORNING AS IT
TRACKS ACROSS MN. WITH THE RAP AT 3Z ANALYZING 20-30 KTS OF 0-3KM
SHEAR OUT AHEAD OF THE SYSTEM...IT IS PLAUSIBLE THAT THAT COULD
HAPPEN...THOUGH IN THE END IT MAY BE DIFFICULT TO GET ANY SEVERE
STRENGTH WINDS THROUGH THE STABLE BOUNDARY LAYER...SO AGREE WITH SPC
MCD THAT SEVERE THREAT WILL BE FAIRLY MARGINAL.
FOR THIS AFTERNOON...MANY A QUESTION MARKS STILL REMAIN IN PLACE.
THIS BIGGEST ISSUE IS HOW WILL STORMS THIS MORNING IMPACT WHAT
HAPPENS LATER. THE MAIN QUESTION IS DOES THE ATMOSPHERE HAVE ENOUGH
TIME TO RECHARGE FROM STORMS MOVING THROUGH LARGELY IN THE 10-18Z
TIME FRAME? FIRST WORD OF WARNING FOR THE ARM CHAIR FORECASTERS OUT
THERE...THE CAMS MAY NOT BE ALL THAT RELIABLE FOR WHAT HAPPENS LATER
THIS AFTERNOON AS ALL OF THEM ARE HANDLING CURRENT CONVECTION QUITE
POORLY /INCLUDING ALL MEMBERS OF THE 3Z HOPWRF/. PROBLEM
IS...OUTSIDE OF THE SPCWRF...NONE OF THE CAMS SNOW THUNDERSTORMS
MOVING ACROSS THE AREA OUTLINED IN THE PARAGRAPH ABOVE...MANY
/INCLUDING THE HOPWRF MEMBERS/ HAVE NOTHING MOVING ACROSS THE MPX
AREA THIS MORNING...SO HARD TO PUT MUCH STOCK IN WHAT THEY ARE DOING
THIS AFTERNOON. THE ONLY ONE TO BE SOMEWHAT CLOSE TO REALITY THIS
MORNING /SPCWRF/...SHOWS VERY LITTLE CONVECTION REDEVELOPING IN THE
MPX AREA THIS AFTERNOON.
CERTAINLY A BIG PLUS FOR THE AFTERNOON...IS OVER THE LAST 24
HOURS...MODELS HAVE SLOWED UP THE PROGRESSION OF THE FRONT ACROSS
THE MPX AREA...WHICH LIKELY EXPLAINS WHY HIGHER SEVERE PROBABILITIES
WERE PULLED NORTHWEST WITH THE DAY1 SPC CONVECTIVE OUTLOOK. CURRENT
MODEL BLEND WOULD SAY THE FRONT MOVES INTO THE NW MPX CWA AROUND
20Z...THE TWIN CITIES AROUND 00Z AND FINALLY CLEARS EAU AREA SHORTLY
AFTER 3Z. THIS PUTS THE FRONT ACROSS MUCH OF THE AREA DURING PEAK
HEATING...THOUGH IT IS STILL DEBATABLE HOW MUCH HEATING WE WILL SEE
BEHIND THE MORNING CONVECTION. IF CURRENT FORECAST WERE TO
HOLD...WITH TEMPERATURES REBOUNDING INTO THE MID 80S TO NEAR
90...WITH DEWPS IN THE LOWER 70S...THEN WE SHOULD HAVE NO PROBLEM
GENERATING 2000-3500 J/KG OF MLCAPE AHEAD OF THE BOUNDARY AS THE
NAM/GFS DO. FROM THE SHEAR PERSPECTIVE...A 40-60 KT MID LEVEL JET
MOVING IN WITH THE UPPER WAVE THIS AFTERNOON/EVENING WILL PROVIDE
PLENTY OF DEEP LAYER SHEAR TO SUPPORT UPDRAFT ROTATION AND STORM
ORGANIZATION...BUT THE 0-3KM SHEAR IS LOOKING MORE SUSPECT ACROSS
THE MPX AREA TO REALLY DRIVE UP A TORNADO THREAT. THE REASON FOR THE
POOR LOW LEVEL SHEAR IS THAT THE PRESSURE PATTERN AHEAD OF THE FRONT
WILL BE FAIRLY BAGGY...WITH LIGHT PREFRONTAL WINDS EXPECTED. IN
ADDITION...THE CORE OF A 30-40 KT LLJ WILL EXTEND FROM CENTRAL IA
TOWARD NE WIS...STAYING JUST SE OF THE MPX AREA. COMBINED...THE WEAK
SFC WINDS AND BETTER LLJ BEING JUST SE OF THE MPX CWA RESULT IN
MARGINAL 0-1 KM AND 0-3 KM SHEAR /MAINLY 20 KTS OR LESS/. BESIDE THE
WEAKER SHEAR...THE WEAK SFC WINDS OUT AHEAD OF THE FRONT WILL ALSO
LIMIT THE AMOUNT OF CONVERGENCE ALONG IT...WHICH MAY HELP EXPLAIN
WHY MANY OF THE CAMS /OUTSIDE OF THE 3Z HOPWRF/ STRUGGLE TO GENERATE
MUCH CONVECTION ALONG THE BOUNDARY THIS AFTERNOON.
IN SUMMARY...CONFIDENCE IS HIGH THAT MCS CURRENTLY OVER ERN SODAK
WILL TRACK ACROSS AREAS SOUTH OF I-94 THIS MORNING. BECAUSE OF
THIS...CONFIDENCE IN HOW THE AFTERNOON PLAYS OUT IS CONSIDERABLY
DIMINISHED. BUT...GIVEN FRONTAL TIMING...EXPECT AT LEAST SCT STORMS
TO DEVELOP ALONG THE FRONT BETWEEN 19Z AND 21Z THAT WILL THEN TRACK
SE THIS EVENING WITH THE FRONT. GIVEN DEGREE OF INSTABILITY AND BULK
SHEAR...LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREAT.
THE WEAKER LOW LEVEL SHEAR MEANS THAT UNLESS A STORM CAN LATCH ON TO
A REMNANT OUTFLOW BOUNDARY...THE TORNADO THREAT APPEARS TO BE
RELATIVELY LOW...THOUGH NOT NEGLIGIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE JUL 9 2013
THE FIRST HALF OF THE PERIOD WILL START OFF DRY AS LARGE SCALE
SUBSIDENCE DOWNSTREAM OF THE UPPER LEVEL RIDGE AXIS BUILDS AN AREA
OF SURFACE HIGH PRESSURE ACROSS THE UPPER MIDWEST. FORECAST
SOUNDINGS SHOW A DRY PROFILE WITH PWATS ONLY AROUND 0.75
INCHES...ALONG WITH LITTLE POTENTIAL FOR CLOUDS DURING THE DAY ON
WEDNESDAY. WINDS WILL GO CALM OVERNIGHT ALLOWING AN INVERSION TO SET
UP AND TEMPERATURES TO COOL DOWN TO THE UPPER 50S ACROSS MOST
LOCATIONS...WITH LOW 60S EXPECTED IN AND AROUND THE METRO DO TO THE
HEAT ISLAND. THURSDAY WILL BE DRY AS WELL WITH THE SURFACE HIGH
STILL SUPPRESSING ANY CHANCE OF PRECIP. BY THURSDAY NIGHT THE SURFACE
HIGH WILL DRIFT EASTWARD AS THE THERMAL RIDGE APPROACHES FROM THE
WEST...AND SOUTHERLY WINDS ON THE BACK SIDE WILL KEEP OVERNIGHT LOWS
IN THE MID TO UPPER 60S ACROSS WESTERN MINNESOTA. FRIDAY SHOULD BE
MUCH WARMER THAN CURRENTLY FORECAST BY THE NUMERICAL MODELS. BOTH
THE GFS AND ECMWF 09.00 HAVE H850 TEMPS 20-22C...WITH SOUTHERLY
WINDS OF 30KTS...YET FOR SOME REASON THE FORECAST SOUNDINGS ONLY
SHOW MIXING UP TO AROUND 900MB. THIS IS CONTRADICTORY TO THE SIMPLE
PROPERTIES THAT GOVERN THE ATMOSPHERE. GIVEN A MID JULY PROFILE THAT
IS CLOUD FREE...TOGETHER WITH THE POTENTIAL FOR MECHANICAL
MIXING...HAVE VERY HIGH CONFIDENCE THAT AFTERNOON TEMPERATURES WILL
CLIMB INTO THE 90S ACROSS SOUTHWEST MINNESOTA.
ON SATURDAY CONFIDENCE IN TEMPERATURES DECREASES CONSIDERABLY AS A
FRONTAL BOUNDARY/TROUGH OF LOW PRESSURE STALLS OUT FROM SOUTHWEST TO
NORTHEAST OVER THE UPPER MIDWEST. THIS WILL INTRODUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS...WHICH WILL GREATLY AFFECT AFTERNOON
HIGHS. THEREFORE DID NOT STRAY TOO MUCH FROM BLENDED GUIDANCE...AND
CONTINUE TO HAVE CHANCES FOR PRECIP INTO EARLY NEXT WEEK. THE BEST
CHANCE FOR RAIN...WITH 1-3 INCH AMOUNTS VERY LIKELY AT A FEW
LOCATIONS ACROSS THE NORTHWEST NEAR CANBY/ALEXANDRIA/ST CLOUD...WILL
BE LATE FRIDAY NIGHT INTO SATURDAY MORNING. LOOKING AHEAD...THE
THERMAL RIDGE WILL TAKE ON A POSITIVE TILT OVER THE UPPER
MISSISSIPPI RIVER VALLEY. ON SUNDAY THE ECMWF DRIVES A SHORTWAVE
ALONG THE US/CANADIAN BORDER THAT SUPPRESSES THE RIDGE...WHILE THE
GFS IS A DAY SLOWER WITH THIS FEATURE. ALSO...AS ALLUDED TO
EARLIER OVERCAST SKIES WILL GREATLY IMPACT HIGH TEMPS SO DID NOT
HAVE THE CONFIDENCE TO DEVIATE FROM A CONSENSUS APPROACH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY MORNING)
ISSUEDAT 1002 PM CDT MON JUL 8 2013
CONVECTION CONTINUES TO INCREASE ACROSS THE DAKOTAS LATE THIS
EVENING. SHORT TERM PROJECTIONS SHOW SCT SHRA/TSRA POTENTIALLY
REACHING KAXN AND KRWF BY 08Z...KSTC BY 10Z AND THE TWIN CITIES BY
12Z. ADJUSTED TIMES IN THE CURRENT TAF PACKAGE TO REFLECT THIS.
THERE REMAINS THE THREAT OF FOG OVERNIGHT...FROM KSTC TO KEAU. THE
INCREASE IN CLOUDS AND THE THREAT OF SHOWERS SHOULD LIMIT HOW LOW
THE VSBY DROPS AT KSTC AND KRNH. KEAU REMAINS THE PRIME LOCATION
FOR IFR OR LOWER BR/FG BETWEEN 09Z AND 12Z. SHOWERS AND A FEW
THUNDERSTORMS SHOULD MOVE ACROSS KRNH AND KEAU TUESDAY MORNING.
MORE ACTIVITY WILL DEVELOP AHEAD OF AN APPROACHING COLD FRONT
TUESDAY AFTERNOON. THIS SHOULD START EARLY IN THE AFTERNOON AROUND
KAXN...KRWF AND KSTC AND REACH THE TWIN CITIES AN WESTERN WI BY
LATE AFTERNOON/EARLY EVENING. INCREASING NW WINDS OF 10 TO 20
KNOTS IN THE WAKE OF THE FRONT FOR TUESDAY NIGHT.
KMSP...
SCT SHRA/TSRA EXPECTED TO PUSH THROUGH THE TWIN CITIES IN THE
12Z-15Z TIME FRAME WITH LINGERING SHOWERS THROUGH THE LATE
MORNING HOURS. A COLD FRONT WILL APPROACHING FROM THE WEST DURING
THE LATE AFTERNOON (21Z). MORE SHRA/TSRA EXPECTED ALONG AND AHEAD
OF THE FRONT WITH FRONTAL PASSAGE STILL LOOKING TO BE AROUND 01Z.
INCREASING NW WINDS OF 15-20 KNOTS BY LATE EVENING AND CONTINUING
OVERNIGHT.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW 10G20KTS.
THU...VFR. WINDS LGT AND VRB.
FRI...VFR. WINDS S 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1255 AM CDT TUE JUL 9 2013
.UPDATE...
ISSUED AT 1255 AM CDT TUE JUL 9 2013
LLJ-DRIVEN SHWRS/TSTMS AND THEIR REMNANTS CONTINUE MOVING E AT 26
KTS. THEIR HIGH-BASED NATURE IS LIMITING RFALL AMTS TO AROUND .1"
WITH UP TO .2" FOR THE LUCKIEST SPOTS. NOT EXPECTING ANY SVR BUT
WE WILL NEED TO KEEP AN EYE FOR HEAT BURST ACTIVITY...PRIMARILY
OVER N-CNTRL KS WHERE PCPN COVERAGE IS LEAST BUT THE INVERTED-V
THERMODYNAMIC PROFILE IS PRESENT.
THE MOST SHORT-TERM ADJUSTMENTS WERE TO BEST RECONFIGURE POPS
BASED ON 88D TRENDS AND WE WILL PROBABLY NEED TO MAKE FURTHER
ADJUSTMENTS AS THE NGT WEARS ON. OTHERWISE...LOW TEMPS APPEAR ON
TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
PLENTY OF THINGS TO PONDER DURING THE NEXT 24 HOURS...INCLUDING AT
LEAST ONE CONDITIONAL RISK FOR SEVERE STORMS THIS EVENING...AND
MAYBE ANOTHER SEVERE RISK ON TUESDAY AFTERNOON/EVENING...ALTHOUGH
CONFIDENCE IS QUITE LOW ON THE LIKELIHOOD/EVOLUTION OF THE LATTER.
IN OTHER DEPARTMENTS...TOMORROW IS CURRENTLY EXPECTED TO BE THE
OVERALL-HOTTEST AFTERNOON OF THE SUMMER SO FAR FOR MOST OF THE
CWA...AND A HEAT ADVISORY HAS BEEN ISSUES FOR SEVERAL
SOUTHERN/SOUTHEAST COUNTIES.
21Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A SOMEWHAT SUBTLE-BUT
EVIDENT EAST-WEST QUASI STATIONARY GENERALLY STRETCHED ACROSS THE
SOUTHERN HALF OF NEBRASKA. IN THE WIND-FIELD...THIS BOUNDARY
SEPARATES A STEADY 15+ MPH SOUTHERLY BREEZE IN NORTH CENTRAL
KANSAS...FORM A LIGHTER...GENERALLY EAST-SOUTHEAST BREEZE WITHIN
MOST OF THE NEBRASKA CWA. ITS ALSO SOMEWHAT OF A MOISTURE
BOUNDARY...WITH MID-50S TO LOW 60S DEWPOINTS RESIDING IN THE
DEEPLY MIXED AIRMASS TO THE SOUTH...AND HIGHER DEWPOINTS MID-60S
TO NEAR 70 MOST AREAS ALONG/NORTH OF I-80. AS DISCUSSED EARLIER
TODAY...NEAR-CRITICAL FIRE DANGER WILL PERSIST FOR A FEW MORE
HOURS ESPECIALLY IN THE PHILLIPS/ROOKS COUNTY AREA IN KS. HIGH
TEMPS THIS AFTERNOON WORKED OUT PRETTY WELL ACROSS THE
SOUTHWESTERN 2/3 OF THE CWA RANGING GENERALLY 95-104
DEGREES...WHILE SOME NORTHEAST AREAS ARE STRUGGLING TO REACH 90
THANKS IN PART TO A BATCH OF MID LEVEL CLOUDS THAT FORMED ON THE
BACK-SIDE OF AN MCV THAT HAS MOVED WELL EAST INTO WESTERN IA.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRM
CONTINUED QUASI-ZONAL FLOW ACROSS THE LOCAL AREA...BETWEEN THE
LARGER-SCALE MID LEVEL RIDGE AXIS STRETCHED WEST-EAST FROM AZ TO
OK...AND A VIGOROUS SHORTWAVE TROUGH MAKING ITS WAY ACROSS THE
ID/MT/CANADA BORDER AREA. THE MAIN LOW-AMPLITUDE SHORTWAVE TROUGH
OF INTEREST FOR THIS EVENING IS CURRENTLY LIFTING OUT OF WY INTO
WESTERN NEB/SD.
LATE THIS AFTERNOON INTO THIS EVENING...THE PRIMARY FOCUS IS ON
HOW MUCH THUNDERSTORM COVERAGE THE CWA WILL SEE...AND WHETHER SOME
OF THIS ACTIVITY COULD BECOME SEVERE. AT PRESENT TIME...RADAR
INDICATES A FEW WEAK-ISH/HIGH-BASED STORMS NEAR THE STATE LINE IN
THE SOUTHWESTERN CWA...LARGELY A RESULT OF VERY STEEP LOW-LEVEL
LAPSE RATES IN THE HOT/DEEPLY MIXED AIRMASS OVER KS.
MEANWHILE...OFF TO THE NORTHWEST...A FEW STRONG TO SEVERE STORMS
HAVE TAKEN OFF IN NORTH CENTRAL/WESTERN NEB...IN AN ENVIRONMENT
CHARACTERIZED BY AROUND 2000+ J/KG MLCAPE AND 30+ KNOTS OF 0-6KM
DEEP LAYER SHEAR. LOCALLY...WITH THE EXCEPTION OF THE HIGH-BASED
STORMS IN OUR SOUTH...MODEL SOUNDINGS SUGGEST THERE IS JUST ENOUGH
OF A CAP IN PLACE TO KEEP CONVECTION FROM DEVELOPING OVERHEAD IN
MOST OF THE CENTRAL/NORTHERN CWA...AIDED IN PART BY SUBSIDENCE
BEHIND THE DEPARTING MCV. AS HAS BEEN THE CASE FOR DAYS
NOW...CONFIDENCE IN THE DETAILS IS LOW IN THIS WEAKLY FORCED
PATTERN...BUT TAKING CUE FROM THE LATEST RAP/HRRR AND 12Z 4KM WRF-
NMM...THE GENERAL EXPECTATION IS FOR MOST OF THE CWA TO REMAIN
STORM FREE THROUGH AT LEAST 00Z/7PM...BEFORE STORM CHANCES
GRADUALLY INCREASE THROUGH THE EVENING HOURS ESPECIALLY NEAR/NORTH
OF I-80...AND LIKELY MAINLY AS A FUNCTION OF ACTIVITY MOVING IN
FROM WESTERN NEBRASKA...ALTHOUGH LOCAL INITIATION NEAR THE SURFACE
BOUNDARY CANNOT BE RULED OUT EITHER. BOTH THE WRF-NMM AND HRRR ARE
FAIRLY AGGRESSIVE BRINGING A CLUSTER OF STORMS...POSSIBLY A SEMI-
ORGANIZED MCS ACROSS ESPECIALLY THE NORTHERN 1/2 OF THE CWA THIS
EVENING...BUT A SIMILAR MODEL DEPICTION YESTERDAY ENDED UP BEING A
BIT OVERDONE...AND THUS HAVE CAPPED POPS AT NO HIGHER THAN 50
PERCENT AT LEAST FOR NOW. WITH MLCAPE REMAINING 1000+ J/KG WELL
INTO THE EVENING HOURS AND WITH AT LEAST MODEST SHEAR...AT LEAST A
LOCALIZED LARGE HAIL AND ESPECIALLY A WIND THREAT IS QUITE
POSSIBLE ESPECIALLY IF STORMS TO THE WEST CAN ORGANIZE AND DEVELOP
A COLD POOL. AGREE WITH SPC IN HIGHLIGHTING THE NORTHERN 1/2 OF
THE CWA FOR THE GREATEST SEVERE THREAT...BUT JUST CANNOT RULE OUT
A STRONG TO SEVERE STORM ANYWHERE IN THE CWA THIS EVENING.
ALTHOUGH THE MAIN SEVERE THREAT SHOULD BE ON THE WANE BY
MIDNIGHT...LINGERED LOW POPS THROUGH THE NIGHT ESPECIALLY ACROSS
THE EASTERN 2/3 OF THE CWA TO ACCOUNT FOR ACTIVITY PERSISTING OR
NEWLY-DEVELOPING WITHIN THE LOW LEVEL JET AXIS...AND JUST AHEAD ON
APPROACHING COLD FRONT. IF NOTHING ELSE...HOPEFULLY PARTS OF THE
CWA CAN RECEIVE SOME MUCH-NEEDED RAINS TONIGHT...BECAUSE THIS MAY
BE ONE OF THE BETTER CHANCES FOR AWHILE. TEMPERATURE-WISE...MADE
ONLY MINOR TWEAKS TO LOWS...WITH THE PREVALENT LIGHT SOUTHERLY
BREEZE HOLDING MOST AREAS UP INTO THE 70-75 RANGE. ALTHOUGH AT
LEAST LIGHT FOG DEVELOPMENT CANNOT BE RULED OUT LATE TONIGHT
ESPECIALLY IN AREAS THAT RECEIVE RAIN...THE PROBABILITY/MAGNITUDE
SEEMED LOW ENOUGH TO OMIT FROM THE FORECAST.
TURNING TO TUESDAY DAYTIME...REALLY DON/T THINK SEVERE STORMS ARE
GOING TO END UP BEING MUCH OF A STORY...AT LEAST THROUGH THE VAST
MAJORITY OF THE DAY. ALOFT...QUASI-ZONAL FLOW WILL START TO TURN A
BIT MORE NORTHWESTERLY IN RESPONSE TO THE PASSAGE OF A FAIRLY
VIGOROUS SHORTWAVE TROUGH FROM EASTERN MT TOWARD NORTHERN MN. AT
THE SURFACE...A FAIRLY WEAK COLD FRONT...MORE EVIDENT IN THE WIND
FIELD THAN ON A THERMOMETER...WILL WORK SOUTHWARD ACROSS THE CWA
AS THE DAY WEARS ON...WITH MOST AREAS SEEING A FEW HOURS OF
LIGHT/VARIABLE WINDS BEFORE A SLIGHTLY MORE STEADY NORTHERLY
BREEZE SETTLES IN. ALONG AND ESPECIALLY JUST AHEAD OF THIS
BOUNDARY...A LOW LEVEL THERMAL RIDGE WILL EXTEND INTO THE CWA FROM
THE SOUTHWEST...PROMOTING WHAT SHOULD BE THE HIGHEST HEAT-INDEX
READINGS OF THE SUMMER SO FAR FOR MOST ALL OF THE CWA...AND IN
SOME SPOTS THE HOTTEST ACTUAL AIR TEMPERATURES. THE ONLY CAVEATS
WOULD BE AN UNEXPECTEDLY STRONG OUTFLOW BOUNDARY FROM CONVECTION
TONIGHT THAT MIGHT HELP ACCELERATE THE COLD FRONT SOUTHWARD
FASTER...AND MAYBE A DENSER-THAN-EXPECTED COVERAGE OF MID LEVEL
CLOUDS OR LINGERING WEAK CONVECTION. BUT ASSUMING NEITHER ONE OF
THESE CAVEATS PLAY OUT...HAVE AIMED FOR ACTUAL HIGH TEMPS RANGING
FROM MID 90S NORTH...UPPER 90S CENTRAL...AND 100-106 NEAR AND
SOUTH OF THE STATE LINE. HEAT INDEX VALUES OF 100+ ARE FORECAST
ACROSS MUCH OF THE SOUTHERN AND EASTERN HALVES OF THE CWA...AND
HAVE ISSUED A HEAT ADVISORY FOR ALL KS ZONES ALONG WITH WEBSTER-
NUCKOLLS-THAYER IN NEBRASKA...WHICH HAVE THE HIGHEST LIKELIHOOD OF
REACHING OR EXCEEDING A 105 HEAT INDEX. FORTUNATELY FOR FIRE
WEATHER CONCERNS IN THE FAR SOUTHWEST COUNTIES...SUSTAINED
WINDS/GUSTS DO NOT LOOK TO EXCEED 20 MPH DURING THE PEAK OF
AFTERNOON HEATING. AS FOR CONVECTIVE CHANCES...FORECAST SOUNDINGS
SUGGEST THAT A FAIRLY STRONG CAP SHOULD PREVAIL THROUGH THE DAY AS
VERY WARM MID LEVEL TEMPS OVERSPREAD THE AREA. AS A RESULT...OTHER
THAN A LINGERING SLIGHT CHANCE OF MORNING STORMS IN EASTERN
COUNTIES RIGHT AWAY IN THE MORNING...WILL AIM FOR A DRY MAJORITY
OF THE DAY...BEFORE BRINGING BACK SLIGHT STORM CHANCES POST-
21Z/4PM. THERE ARE AT LEAST TWO POSSIBLE FOCUSES FOR LATE
AFTERNOON DEVELOPMENT...THE MAIN COLD FRONT WHICH SHOULD BE VERY
NEAR THE FAR SOUTHEAST CORNER OF THE CWA...AND ALSO FORCING FROM
THE SOUTHERN EDGE OF THE NORTHERN PLAINS SHORTWAVE TROUGH...WHICH
COULD KICK OFF CONVECTION CLOSER TO THE NORTHERN EDGE OF THE CWA.
HOWEVER...MODELS SUCH AS THE 12Z 4KM WRF-NMM ADVERTISE ESSENTIALLY
NO LATE AFTERNOON STORMS ANYWHERE IN THE CWA...SO THUS ONLY THE
SLIGHT POPS. IF STORMS WOULD MANAGE TO FORM...A CONDITIONAL SEVERE
THREAT COULD EXIST ALMOST ANYWHERE IN THE CWA...POTENTIALLY EVEN
WEST OF THE SPC DAY 2 SLIGHT RISK AREA. PLENTY OF UNCERTAINTY FOR
SURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 455 PM CDT MON JUL 8 2013
MAIN FORECAST CONCERNS
WILL BE CHANCES FOR THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY NIGHT
AND AGAIN SATURDAY NIGHT THROUGH MONDAY AND TEMPERATURES.
MODELS ARE FAIRLY SIMILAR IN BUILDING AN UPPER LEVEL RIDGE ACROSS
THE AREA DURING THE PERIOD...BUT THE DETAILS OF THE TIMING MAINLY
WEAK UPPER LEVEL WAVES THROUGH THE AREA ARE SOMEWHAT DIFFERENT
BETWEEN THE MODELS. THIS BRINGS SOME UNCERTAINTY IN WHEN THERE WILL
BE SOME CHANCES FOR THUNDERSTORMS.
A SURFACE COLD FRONT WILL MOVE TO THE SOUTH ACROSS THE SOUTHERN PART
OF THE FORECAST AREA DURING THE EVENING. AN UPPER LEVEL WAVE WILL
ALSO BE MOVING THROUGH THE AREA. EXPECT SOME THUNDERSTORMS ALONG
THAT BOUNDARY DURING THE EVENING...BUT OVERNIGHT THEY SHOULD MOVE
OUT OF THE AREA. MUCAPE IS THE HIGHEST DURING THE EARLY EVENING
HOURS AND DIMINISHES SOME LATER IN THE EVENING...BUT STILL REMAINS
AROUND 2500 J/KG. EXPECT THAT THERE COULD BE SOME SEVERE WEATHER
DURING THE EVENING.
A COOL SURFACE HIGH PRESSURE SYSTEM SETTLES INTO THE AREA ON
WEDNESDAY. HIGH TEMPERATURES WILL BE AROUND 10 DEGREES COOLER THAN
ON TUESDAY. WEDNESDAY SHOULD REMAIN DRY...BUT AN UPPER LEVEL WAVE
MOVES ACROSS THE RIDGE AND THERE COULD BE SOME ISOLATED SHOWERS AND
THUNDERSTORMS THAT MOVE OFF THE HIGH PLAINS DURING THE NIGHT TIME
HOURS.
THE SURFACE HIGH MOVES OFF TO THE EAST ON THURSDAY AND THE SURFACE
PRESSURE GRADIENT TIGHTENS. WINDS AT 850MB ARE ONLY 20 TO 25 KTS SO
EXPECT SOME BREEZY CONDITIONS. WITH WINDS FROM THE SOUTH THE
TEMPERATURES WILL WARM UP.
THE UPPER LEVEL RIDGE CONTINUES TO BUILD ACROSS THE AREA FOR THE
PERIOD THURSDAY THROUGH SATURDAY. EXPECT TEMPERATURES TO WARM A
LITTLE EACH DAY THROUGH THE PERIOD.
THE UPPER LEVEL RIDGE REMAINS IN PLACE FOR SATURDAY NIGHT THROUGH
MONDAY...BUT IT IS MORE OF AN UPPER LEVEL HIGH PRESSURE SYSTEM
ACROSS THE AREA. IT IS FAIRLY BROAD AND THERE ARE A FEW UPPER LEVEL
WAVES THAT MOVE THROUGH THE AREA. SIMILAR TO THE PAST WEEK OR SO
EACH OF THESE UPPER LEVEL WAVES HAS A CHANCE FOR SOME THUNDERSTORMS.
DO NOT EXPECT THAT IT WILL BE WIDESPREAD OR THAT EVERYONE WILL HAVE
SOME PRECIPITATION. THE TIMING AND THE LOCATION OF ANY PRECIPITATION
IS IN QUESTION. WITH A FEW MORE CLOUDS AND THE CHANCE FOR SOME
PRECIPITATION THE TEMPERATURES WILL BE A LITTLE COOLER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1255 AM CDT TUE JUL 9 2013
REST OF TNGT: VFR -RA/THUNDER LIKELY THRU 07Z THEN EXPECT DRY WX
THEREAFTER. WINDS WILL BE VARIABLE AROUND PCPN. LLWS. MAYBE A
TOUCH OF MVFR FOG NEAR DAYBREAK?
TUE: VFR WITH SW WINDS 10 KTS OR LESS. WINDS MAY BECOME LGT AND
VARIABLE 17-21Z. THEN COOL FRONT WILL SHIFT WINDS TO NW. THERE
COULD BE SOME ISOLATED TSTM ACTIVITY NEARBY AFTER 21Z.
TUE THRU 06Z: VFR. NW WINDS AROUND 10 KTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
NEZ085>087.
KS...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
KSZ005>007-017>019.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...PFANNKUCH
LONG TERM...JCB
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
424 AM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRYER AIR WILL
FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
EXPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
330 AM UPDATE...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. STILL
LOOKING LIKE WE MAY SEE AT LEAST A FEW DAYS OF DRY WEATHER
STARTING FRIDAY...ESPECIALLY BASED ON THE NEW 0Z EURO. I DID
MAINTAIN OUR GOING FORECAST OF SLIGHT TO LOW CHANCE (20 TO 30%)
POPS THIS WEEKEND WITH THE GFS HINTING AT A DISTURBANCE ALOFT IN
THE NORTHEAST DURING THIS TIME. THIS ALSO MATCHES UP WITH POP
GUIDANCE FROM WPC. WITH THAT SAID BASED ON THE EURO AND SURFACE
HIGH PRESSURE BUILDING IN...THE REALITY MAY BE A DRY WEEKEND. THE
PREVIOUS AFD IS BELOW...
STAGNANT PTRN CONTS TO MAKE FOR A TRICKY XTNDD PD. LATEST
OPERATIONAL GFS RUN TRENDS TWRDS LAST NGT/S EURO WITH THU/S BRIEF
RDGG GIVING WAY TO YET ANOTHER RETROGRADING OFF SHORE TROF.
MASSIVE BERMUDA HI CONTS TO BLOCK THE EWRD PROGRESS OF NRN STREAM
WV/S KEEPING THE NORTH BOUND TROPICAL FLOW IN PLACE ALONG THE CST
NEAR TO OUR FCST AREA. FOR NOW...IT LOOKS LIKE THE MAJORITY OF THE
MOISTURE ASSOCIATED WITH CHANTAL WELL EAST OF THE AREA...BUT WITH
THE UNCERTAINTY...THIS DEEP MOISTURE WILL NEED TO BE MONITORED.
DAILY SENSIBLE WX WILL SHOW SOME IMPRMNT ALTHOUGH THE ERN AND SRN
AREA WILL CONT TO BE NEAR THE EDGE OF THE DEEP MOISTURE AND MORE
AT RISK OF TRWS...ESP LATE IN THE PD. GNRLY FLWD HPC GUID BUT
NUDGED THE DATA TWRD THE MEX AND NEARER TO THE SURROUNDING OFFICES.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
PERIODS OF FOG...PRODUCING IFR RESTRICTIONS ARE POSSIBLE THROUGH
DAYBREAK ESPECIALLY AT KELM/KITH/KBGM WITH THESE SITES SEEING THE
MOST RAIN MONDAY AFTERNOON. A COMPLICATING FACTOR WILL BE AN AREA
OF HIGH CLOUDS NOW OVER WESTERN NY THAT WILL SLIDE EAST DURING
THIS PERIOD. WITH IFR RESTRICTIONS ALREADY AT ALL THREE SITES
BEING TEMPERED BY THIS HIGH CLOUD THREAT...ELECTED TO MAINLY GO
WITH TEMPO GROUPS FOR IFR GIVEN THE HIGH VARIABILITY EXPECTED
THROUGHOUT THE NIGHT. KELM STANDS THE BEST CHANCE FOR GOING DOWN
AND STAYING DOWN. ELSEWHERE VFR IS EXPECTED.
ANY FOG SHOULD BURN OFF BETWEEN 12Z AND 13Z. AFTER THAT A
DISTURBANCE MOVING THROUGH LATER IN THE DAY WILL BRING SCT.
SHOWERS TO THE TERMINALS MAINLY DURING THE PEAK HEATING (18Z -
0Z). WHILE THUNDER IS POSSIBLE I DID NOT INCLUDE IN THE TAFS JUST
YET GIVEN THE EXPECTED SCT. COVERAGE.
.OUTLOOK...
WED THRU THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT
SHWRS AND TRWS. IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...DGM/HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 AM CDT TUE JUL 9 2013
.UPDATE...
ISSUED AT 1254 AM CDT TUE JUL 9 2013
SEVERE TSTM WATCH 402 HAS EXPIRED...AND ALSO CANCELLED WATCH 403
FOR 4 COUNTIES IN NORTH CENTRAL NORTH DAKOTA. WATCH 403 REMAINS
VALID UNTIL 4 AM CDT FOR A LINE FROM EMMONS TO WELLS COUNTIES AND
EASTWARD. EXPECT TO BE ABLE TO DROP THESE COUNTIES IN THE NEXT
HOUR OR 2 AS SEVERE LINE MOVES THROUGH.
UPDATE ISSUED AT 1150 PM CDT MON JUL 8 2013
WILL LEAVE SEVERE T-STORM WATCH 403 AS IS FOR NOW. WILL EXTEND SVR
WATCH 402 FOR MORTON...GRANT...AND SIOUX COUNTIES FOR ONE MORE
HOUR WITH A LINE OF STORMS MOVING ACROSS THOSE COUNTIES RIGHT NOW.
WHILE THE THREAT APPEARS LOW WITH THE BETTER SEVERE PARAMETERS IN
SOUTH DAKOTA...FIGURE ONE MORE HOUR WILL NOT HURT...WHEN PERHAPS
PART OF 403 CAN BE LET GO AS WELL.
UPDATED PRODUCTS OUT SHORTLY.
UPDATE ISSUED AT 1013 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO EXTEND THE SEVERE THUNDERSTORM WATCH EAST
INTO THE JAMES RIVER VALLEY.
MCS OVER WEST CENTRAL NORTH DAKOTA DEVELOPED INTO AN MCV IN THE
LAST HOUR OR TWO. THE LEADING EDGE OF THIS ACTIVITY HAS BEEN
PRODUCING WIDESPREAD WIND GUSTS UP TO 60 MPH. THIS ACTIVITY WILL
CONTINUE TO PUSH EAST INTO THE JAMES RIVER VALLEY AFTER MIDNIGHT.
ANOTHER BOW ECHO IS PUSHING EAST ACROSS SOUTHWESTERN NORTH DAKOTA.
ITS STORM MOTION HAS BEEN EAST-SOUTHEAST AND WILL LIKELY CONTINUE
TO PUSH INTO SOUTH DAKOTA DURING THE NEXT FEW HOURS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 703 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO ADD SEVERE THUNDERSTORM WATCH 402 FOR
AREAS WEST OF HIGHWAY 83.
ONGOING CONVECTION OVER EAST-CENTRAL MONTANA SHOULD CONTINUE TO
MOVE EAST-SOUTHEAST INTO SOUTHWESTERN NORTH DAKOTA EARLY THIS
EVENING. THIS ACTIVITY IS CONGEALING INTO AN MCS AND IS MOVING
INTO A FAVORABLE ENVIRONMENT FOR MCS MAINTENANCE (SURFACE BASED
CAPE AROUND 2000 J/KG PER LATEST LAPS ANALYSIS). THIS INITIAL
CONVECTIVE ACTIVITY PROMPTED SPC TO ISSUE A SEVERE THUNDERSTORM
WATCH FOR AREAS WEST OF HIGHWAY 83 UNTIL MIDNIGHT CDT.
SHORT-RANGE MESOSCALE MODELS CONTINUE TO PROG THE PRIMARY LINE
OF CONVECTION (CURRENTLY EXTENDING FROM GLASGOW TO BILLINGS) TO
PUSH INTO WESTERN NORTH DAKOTA AROUND 03Z...AND SWEEP ACROSS THE
CWA TONIGHT. THE FLY IN THE OINTMENT IS JUST HOW MUCH INSTABILITY
THE INITIAL MCS CHEWS UP BEFORE THE PRIMARY LINE SWINGS THROUGH.
STILL WILL MAINTAIN SEVERE WORDING PAST MIDNIGHT FOR CENTRAL NORTH
DAKOTA. HOWEVER...WILL CONTINUE TO MONITOR EVENING TRENDS AND
MAKE ANY ADJUSTMENTS AS NEEDED. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FORECAST ISSUE DURING THE SHORT TERM IS STORM
COVERAGE/TIMING/SEVERITY THROUGH TONIGHT. SCATTERED STORMS ARE
EXPECTED TO DEVELOP AND/OR MOVE INTO THE WEST LATE THIS AFTERNOON.
MORE FAVORABLE DEEP LAYER SHEAR IS CONFINED TO THE WEST THROUGH
LATE AFTERNOON. SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH
LARGE HAIL THE MAIN THREAT. THE HRRR IS STILL FOCUSING ON THE SOUTHWEST
FOR INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING
FROM WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. WILL CONTINUE
TO MONITOR CLOSELY FOR INITIATION. AN INTENSE SUPERCELL IS MOVING
THROUGH NORTHEAST MONTANA...AND WOULD IMPACT THE FORECAST AREA
AFTER 00Z IF IT HOLDS TOGETHER. A BIGGER CONCERN WILL BE A
THUNDERSTORM COMPLEX THAT WILL LIKELY TRACK FROM WEST TO EAST
ACROSS THE FORECAST AREA AFTER AROUND 9 PM CDT. DAMAGING STRAIGHT
LINE WINDS WILL BE THE BIGGEST THREAT. FAST STORM MOTIONS SHOULD
PRECLUDE WIDESPREAD FLASH FLOODING. A MULTI- MEDIA WEATHER BRIEFING
HAS BEEN POSTED AT WWW.WEATHER.GOV/BIS. THE SEVERE THREAT MAY
PERSIST AFTER MIDNIGHT TONIGHT BEFORE STORMS WEAKEN. ADDITIONAL
NON-SEVERE STORMS WILL BE LIKELY THROUGH AT LEAST MIDDAY TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
MAIN HIGHLIGHT FOR THE LONG TERM IS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT ENTERING NORTHERN PLAINS THURSDAY/FRIDAY.
THE PERSISTENT HIGH AMPLITUDE RIDGING TO THE WEST WILL CONTINUE TO
BE BOMBARDED BY SHORTWAVE TROUGHS DIVING DOWN OUT OF WESTERN
CANADA. THIS WILL FORCE THE RIDGE TO TRANSLATE EASTWARD OVER THE
CENTRAL STATES. THIS WILL IN TURN ALLOW NORTH DAKOTA TO BE
INFLUENCED BY SOUTHWESTERLY FLOW AND LEE CYCLOGENESIS. BOTH THE
12 UTC ECMWF AND THE 12 UTC GFS BOTH HAVE A SHORTWAVE TROUGH
DRAPED ACROSS THE NORTHERN PLAINS AND SURFACE LOW OVER
NORTHWESTERN SOUTH DAKOTA EARLY FRIDAY MORNING. THIS WILL ALLOW
FOR MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT. WITH INCREASING
MOISTURE...SURFACE LOW PRESSURE...AND UPPER LEVEL DIFFLUENCE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS POSSIBLE FRIDAY AFTERNOON
AND EVENING. IN ADDITION TO THOSE INGREDIENTS THE 12 UTC ECMWF IS
FORECASTING 50+ KNOTS OF 0-6 KM SHEAR...2000+ MUCAPE...AND DEW
POINTS IN THE MID TO UPPER 60S. IF THIS VERIFIES...SEVERE WEATHER
IS POSSIBLE FRIDAY AFTERNOON AND EVENING.
OTHERWISE...THE EXTENDED PERIOD LOOKS ACTIVE WITH CHANCES FOR
PRECIP THROUGHOUT THE PERIOD AS SHORTWAVES RIDE ALONG THE
NORTHERN PERIPHERY OF THE RIDGE TO OUR SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1254 AM CDT TUE JUL 9 2013
EXPECT THUNDERSTORMS AT KMOT/KBIS/KJMS TO CONTINUE THROUGH AROUND
09Z...WITH A POSSIBLE LINE GOING THROUGH KJMS AGAIN AFTER 09Z.
KDIK MAY HAVE TSTMS LINGER THROUGH 07Z...BUT KISN SHOULD BE OUT OF
THE MAIN LARGE AREA OF CONVECTION. MODELS HINTING AT MVFR CIGS
DEVELOPING BY 09Z...THEN VFR BY 12Z/15Z. CIGS SCATTERING FROM WEST
TO EAST AFT 18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...RPK
LONG TERM...AJ
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1151 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 1150 PM CDT MON JUL 8 2013
WILL LEAVE SEVERE T-STORM WATCH 403 AS IS FOR NOW. WILL EXTEND SVR
WATCH 402 FOR MORTON...GRANT...AND SIOUX COUNTIES FOR ONE MORE
HOUR WITH A LINE OF STORMS MOVING ACROSS THOSE COUNTIES RIGHT NOW.
WHILE THE THREAT APPEARS LOW WITH THE BETTER SEVERE PARAMETERS IN
SOUTH DAKOTA...FIGURE ONE MORE HOUR WILL NOT HURT...WHEN PERHAPS
PART OF 403 CAN BE LET GO AS WELL.
UPDATED PRODUCTS OUT SHORTLY.
UPDATE ISSUED AT 1013 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO EXTEND THE SEVERE THUNDERSTORM WATCH EAST
INTO THE JAMES RIVER VALLEY.
MCS OVER WEST CENTRAL NORTH DAKOTA DEVELOPED INTO AN MCV IN THE
LAST HOUR OR TWO. THE LEADING EDGE OF THIS ACTIVITY HAS BEEN
PRODUCING WIDESPREAD WIND GUSTS UP TO 60 MPH. THIS ACTIVITY WILL
CONTINUE TO PUSH EAST INTO THE JAMES RIVER VALLEY AFTER MIDNIGHT.
ANOTHER BOW ECHO IS PUSHING EAST ACROSS SOUTHWESTERN NORTH DAKOTA.
ITS STORM MOTION HAS BEEN EAST-SOUTHEAST AND WILL LIKELY CONTINUE
TO PUSH INTO SOUTH DAKOTA DURING THE NEXT FEW HOURS.
THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 703 PM CDT MON JUL 8 2013
UPDATED THE FORECAST TO ADD SEVERE THUNDERSTORM WATCH 402 FOR
AREAS WEST OF HIGHWAY 83.
ONGOING CONVECTION OVER EAST-CENTRAL MONTANA SHOULD CONTINUE TO
MOVE EAST-SOUTHEAST INTO SOUTHWESTERN NORTH DAKOTA EARLY THIS
EVENING. THIS ACTIVITY IS CONGEALING INTO AN MCS AND IS MOVING
INTO A FAVORABLE ENVIRONMENT FOR MCS MAINTENANCE (SURFACE BASED
CAPE AROUND 2000 J/KG PER LATEST LAPS ANALYSIS). THIS INITIAL
CONVECTIVE ACTIVITY PROMPTED SPC TO ISSUE A SEVERE THUNDERSTORM
WATCH FOR AREAS WEST OF HIGHWAY 83 UNTIL MIDNIGHT CDT.
SHORT-RANGE MESOSCALE MODELS CONTINUE TO PROG THE PRIMARY LINE
OF CONVECTION (CURRENTLY EXTENDING FROM GLASGOW TO BILLINGS) TO
PUSH INTO WESTERN NORTH DAKOTA AROUND 03Z...AND SWEEP ACROSS THE
CWA TONIGHT. THE FLY IN THE OINTMENT IS JUST HOW MUCH INSTABILITY
THE INITIAL MCS CHEWS UP BEFORE THE PRIMARY LINE SWINGS THROUGH.
STILL WILL MAINTAIN SEVERE WORDING PAST MIDNIGHT FOR CENTRAL NORTH
DAKOTA. HOWEVER...WILL CONTINUE TO MONITOR EVENING TRENDS AND
MAKE ANY ADJUSTMENTS AS NEEDED. THE UPDATED GRIDDED AND TEXT
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
THE MAIN FORECAST ISSUE DURING THE SHORT TERM IS STORM
COVERAGE/TIMING/SEVERITY THROUGH TONIGHT. SCATTERED STORMS ARE
EXPECTED TO DEVELOP AND/OR MOVE INTO THE WEST LATE THIS AFTERNOON.
MORE FAVORABLE DEEP LAYER SHEAR IS CONFINED TO THE WEST THROUGH
LATE AFTERNOON. SOME ISOLATED SEVERE STORMS ARE POSSIBLE...WITH
LARGE HAIL THE MAIN THREAT. THE HRRR IS STILL FOCUSING ON THE SOUTHWEST
FOR INITIATION...WHILE THE 12Z WRF FOCUSES ON A FRONT STRETCHING
FROM WEST CENTRAL INTO NORTH CENTRAL NORTH DAKOTA. WILL CONTINUE
TO MONITOR CLOSELY FOR INITIATION. AN INTENSE SUPERCELL IS MOVING
THROUGH NORTHEAST MONTANA...AND WOULD IMPACT THE FORECAST AREA
AFTER 00Z IF IT HOLDS TOGETHER. A BIGGER CONCERN WILL BE A
THUNDERSTORM COMPLEX THAT WILL LIKELY TRACK FROM WEST TO EAST
ACROSS THE FORECAST AREA AFTER AROUND 9 PM CDT. DAMAGING STRAIGHT
LINE WINDS WILL BE THE BIGGEST THREAT. FAST STORM MOTIONS SHOULD
PRECLUDE WIDESPREAD FLASH FLOODING. A MULTI- MEDIA WEATHER BRIEFING
HAS BEEN POSTED AT WWW.WEATHER.GOV/BIS. THE SEVERE THREAT MAY
PERSIST AFTER MIDNIGHT TONIGHT BEFORE STORMS WEAKEN. ADDITIONAL
NON-SEVERE STORMS WILL BE LIKELY THROUGH AT LEAST MIDDAY TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CDT MON JUL 8 2013
MAIN HIGHLIGHT FOR THE LONG TERM IS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT ENTERING NORTHERN PLAINS THURSDAY/FRIDAY.
THE PERSISTENT HIGH AMPLITUDE RIDGING TO THE WEST WILL CONTINUE TO
BE BOMBARDED BY SHORTWAVE TROUGHS DIVING DOWN OUT OF WESTERN
CANADA. THIS WILL FORCE THE RIDGE TO TRANSLATE EASTWARD OVER THE
CENTRAL STATES. THIS WILL IN TURN ALLOW NORTH DAKOTA TO BE
INFLUENCED BY SOUTHWESTERLY FLOW AND LEE CYCLOGENESIS. BOTH THE
12 UTC ECMWF AND THE 12 UTC GFS BOTH HAVE A SHORTWAVE TROUGH
DRAPED ACROSS THE NORTHERN PLAINS AND SURFACE LOW OVER
NORTHWESTERN SOUTH DAKOTA EARLY FRIDAY MORNING. THIS WILL ALLOW
FOR MOIST SOUTHERLY FLOW AHEAD OF THE COLD FRONT. WITH INCREASING
MOISTURE...SURFACE LOW PRESSURE...AND UPPER LEVEL DIFFLUENCE
WIDESPREAD THUNDERSTORM DEVELOPMENT IS POSSIBLE FRIDAY AFTERNOON
AND EVENING. IN ADDITION TO THOSE INGREDIENTS THE 12 UTC ECMWF IS
FORECASTING 50+ KNOTS OF 0-6 KM SHEAR...2000+ MUCAPE...AND DEW
POINTS IN THE MID TO UPPER 60S. IF THIS VERIFIES...SEVERE WEATHER
IS POSSIBLE FRIDAY AFTERNOON AND EVENING.
OTHERWISE...THE EXTENDED PERIOD LOOKS ACTIVE WITH CHANCES FOR
PRECIP THROUGHOUT THE PERIOD AS SHORTWAVES RIDE ALONG THE
NORTHERN PERIPHERY OF THE RIDGE TO OUR SOUTH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 703 PM CDT MON JUL 8 2013
THE MAIN FOCUS THROUGH THE TAF PERIOD IS THUNDERSTORMS.
OTHERWISE...EXPECT VFR CONDITIONS. SCATTERED STORMS ARE EXPECTED
THIS EVENING...BUT TOUGH TO PINPOINT FAVORED AREA FOR DEVELOPMENT
AND TIMING. LATER TONIGHT...AFTER 02Z...ENHANCED WINDS WILL BE
POSSIBLE WITH FAST MOVING LINES OF THUNDERSTORMS. ALTHOUGH THESE
SEVERE WEATHER ELEMENTS WILL BE POSSIBLE..TOO UNCERTAIN IN TIMING
TO INCLUDE IN TAF FORECAST. AVIATION PLANNERS SHOULD ANTICIPATE
MULTIPLE LINES OF THUNDERSTORMS MOVING WEST TO EAST ACROSS THE
STATE AFTER 02Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...RPK
LONG TERM...AJ
AVIATION...TM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
417 AM EDT TUE JUL 9 2013
.SYNOPSIS...
THE WEATHER WILL REMAIN UNSETTLED ACROSS THE LOWER GREAT LAKES AND
OHIO VALLEY TODAY AND TONIGHT AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE AREA ON WEDNESDAY. THURSDAY AND FRIDAY HIGH PRESSURE
AND DRY STABLE AIR WILL BUILD IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MADE ADJUSTMENT TO THE FLOOD WATCH TRIMMING THE NORTHERN COUNTIES
BUT EXTENDING IT A FEW HOURS INTO THE MORNING FOR THE REMAINING
SOUTHERN COUNTIES. RADAR SHOWS THE HEAVY RAIN MOVING SLOWLY EAST
HOWEVER MORE SHOWERS HAVE DEVELOPED ON THE WEST SIDE OF THE MAIN
CONVECTION ACROSS PORTIONS OF CRAWFORD/WYANDOT AND MARION
COUNTIES. RAIN STILL OCCURRING ACROSS THE CENTRAL LAKESHORE BUT IS
NOT INTENSE ENOUGH TO CAUSE FLOODING. FOR THE MORNING EXPECT THE
TREND IN PLACE TO SLOWLY CONTINUE WITH PRECIP MOVING
EAST/SOUTHEAST OF THE AREA AND DRIER AIR MOVING IN FROM THE
NORTHWEST. SHOULD EVENTUALLY SEE SOME SS TODAY HOWEVER HRRR DOES
SHOW SCATTERED CONVECTION REDEVELOPING IN THE MOIST UNSTABLE AIR
STILL IN PLACE ACROSS THE AREA LATER THIS AFTERNOON. BEST CHANCES
WOULD BE WEST/SWRN COUNTIES. WILL BRING CHANCE POPS BACK TO THE
SRN/SWRN COUNTIES WITH SLIGHT CHANCE POPS ON THE NORTH SIDE OF
THAT. HIGHS NEAR GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FOLLOWED MIX OF HPC/NAM AND SREF GUIDANCE FOR THE SHORT TERM. COLD
FRONT IS ON THE WAY FOR WEDNESDAY AND TONIGHT AHEAD OF THE FRONT MODELS
SHOWED A COUPLE SHORT WAVES MOVING ACROSS THE REGION. EXPECTING
SHOWERS/THUNDERSTORMS MOVING IN FROM THE WEST LATE EVENING OR
EARLY IN THE NIGHT AND PERSISTING THROUGH MUCH OF WEDNESDAY. WOULD
ANTICIPATE THE NEED FOR A FLOOD WATCH BUT GIVEN THE CURRENT
HEADLINE WILL WAIT FOR DAY SHIFT TO REEVALUATE. GIVEN HPC QPF
VALUES INCREASED MAV GUIDANCE POPS AGREEING MORE WITH THE SREF
CATEGORICAL GUIDANCE TONIGHT AND WEDNESDAY. THURSDAY AND FRIDAY
SUN AND DRY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS HAVE BEEN SLOWLY TRENDING TO A DRIER WEEKEND WITH THE CENTRAL
U.S. RIDGE TRYING TO NOSE INTO THE LOWER GREAT LAKES AND THE TROUGH
SHIFTING TO THE EAST COAST. THIS WILL PUT IS IN THE MIDDLE AND WILL
KEEP THE DRY WEEKEND FORECAST AND THE LOW PRECIP CHANCES FOR MONDAY
WITH AN INCREASE IN MOISTURE. WILL PUT TEMPS IN BETWEEN GFS AND
ECMWF GUIDANCE AS A COMPROMISE SEEMS BEST RIGHT NOW. THAT WILL GIVE
US SEASONABLE TEMPS FOR THE WEEKEND IN THE LOWER TO MID 80S.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS REMAIN FOR THE REMAINDER OF
THE NIGHT. IFR WITHIN THESE SHRA/TS. SOME AREAS OF MVFR AS WELL.
BIGGEST TASK IS WHETHER NON VFR CEILINGS OF VSBYS WILL DEVELOP IN
A MORE WIDESPREAD NATURE. LATEST SREF BRINGS IN MVFR AND SOME IFR
ACROSS SOUTHERN MI ACROSS ONTARIO AND INTO NW PA. HAVE LEANED THIS
WAY AND HAVE BROUGHT THE LOWEST CONDITIONS INTO TOLEDO. WITH
DOWNSLOPE FLOW DID NOT GO TOO LOW AT ERIE. EVEN THOUGH THERE IS
PLENTY OF LOW LEVEL MOISTURE...LIGHT WIND AND CURRENT CIGS SHOULD
PREVENT VSBY FROM GETTING TOO LOW. START MOST AT MVFR IN MID
MORNING...IMPROVING TO VFR. MOST OF THE SHOWERS LOOK TO BE OVER BY
AROUND 12Z...BUT AREA MAY GET NEW DEVELOPMENT AGAIN TOWARD YNG/CAK
LATE THIS AFTERNOON. UNSURE ABOUT FDY/MFD. AGAIN THIS IS FOCUSING
ON THE TIMES WITH THE BEST CHANCES...STILL COULD SEE A SHRA/TS AT
JUST ABOUT ANY TIME.
.OUTLOOK...NON-VFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH
WEDNESDAY NIGHT.
&&
.MARINE...
A RELATIVE LULL IN THE THUNDERSTORM CHANCES FOR TODAY. SOUTH-SW FLOW
WILL CONTINUE WITH A NEARLY STATIONARY BOUNDARY JUST NORTH OF THE
LAKE. LOW PRESSURE WILL TRACK ACROSS THE NORTHERN LAKES WEDNESDAY
AND TAKE A COLD FRONT ACROSS LAKE ERIE WITH ANOTHER ROUND OF
THUNDERSTORMS...SOME OF WHICH WILL BE ON THE STRONG SIDE. WINDS MAY
PICK UP ENOUGH TO NEED A SMALL CRAFT ADV WITH THIS SYSTEM. SOME CHOP
POSSIBLE WEDNESDAY AHEAD OF THE FRONT FOR THE EASTERN NEARSHORE WITH
SW FLOW ALONG THE LENGTH OF THE LAKE. BETTER CHANCES FOR SMALL CRAFT
ADV CONDITIONS IN THE NORTHWEST FLOW AFTER THE FRONT. THE WEATHER
SETTLES DOWN THURSDAY THROUGH SATURDAY WITH HIGH PRESSURE OVER THE
CENTRAL GREAT LAKES. WILL HAVE A NORTHERLY FLOW THAT WILL BECOME ENE
BY SATURDAY AS THE HIGH SHIFTS EAST...REMAINING NORTH OF LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 9 AM EDT THIS MORNING FOR OHZ027>030-
036-037-047.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK/KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
413 AM EDT TUE JUL 9 2013
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH WEDNESDAY
NIGHT. A COLD FRONT WILL CROSS THE REGION LATE WEDNESDAY NIGHT.
HIGH PRESSURE BEHIND THE FRONT WILL BRING DRIER WEATHER TO THE
AREA THAT WILL LAST INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A DISTURBANCE MOVING EAST OUT OF CENTRAL OHIO THIS MORNING WILL
TAKE WITH IT THE STRONG MOISTURE TRANSPORT AND HEAVIER SHOWERS AND
THUNDERSTORMS. IN ITS WAKE...SCATTERED SHOWERS WILL BE POSSIBLE
THROUGH THE MORNING HOURS. ANOTHER DISTURBANCE UPSTREAM OF THE
AREA WILL HELP TO TRIGGER ADDITIONAL SHOWERS AND THUNDERSTORMS THIS
AFTERNOON. A BOUNDARY ACROSS THE OHIO RIVER THIS MORNING WILL
LIFT NORTH JUST AHEAD OF THIS DISTURBANCE AND SHOULD BE THE FOCUS OF
WHERE CONVECTION INITIATES THIS AFTERNOON. THERE ARE SUBTLE
DIFFERENCES IN WHERE THIS LOCATION WILL BE. FAVORED THE ARW FOR
THE INITIAL CONVECTION DEVELOPMENT ALONG AND NORTH OF THE
INTERSTATE 70 CORRIDOR...GRADUALLY SHIFTING SOUTH AND EAST
IN FOCUS TOWARD THE EVENING. CLOUD COVER MAY PREVENT TEMPERATURES
FROM RISING INTO THE UPPER 80S THIS AFTERNOON. AS SUCH...WENT WITH
THE MIDDLE 80S FOR MOST OF OUR ZONES. WILL KEEP THE FLASH FLOOD
WATCH UP UNTIL 10 AM FOR OUR EXTREME NORTHEASTERN ZONES...NEARER
TO THE DEPARTING CONVECTION. HAVE REMOVED THOSE COUNTIES THAT HAVE
NOT SEEN MUCH IN THE WAY OF HEAVY RAIN...AND WILL LIKELY NOT SEE
MUCH MORE RAIN BEFORE THE WATCH EXPIRES. THIS
AFTERNOON...REDEVELOPING CONVECTION COULD ONCE AGAIN POSE A
FLOODING THREAT. WILL HIGHLIGHT THIS THREAT IN THE HWO FOR NOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SIMILAR TO PREVIOUS NIGHTS...IN THIS VERY MOIST AIRMASS AND WITH
A PASSING DISTURBANCE IN THE AREA...CONVECTION WILL PROBABLY BE
ONGOING AS WE HEAD INTO TONIGHT`S TIME PERIOD. THE EVENING
CONVECTION IS EXPECTED TO BE SHIFTING TOWARD THE SOUTH AND EAST IN
THE NORTHWESTERLY FLOW ALOFT TO START TONIGHT. UPSTREAM...A
DEVELOPING NOCTURNAL LOW LEVEL JET IS EXPECTED TO ENHANCE
CONVECTION AFTER SUNSET. THIS CONVECTION WILL PERSIST ACROSS
PORTIONS OF OUR AREA OVERNIGHT. THERE IS UNCERTAINTY AS TO WHERE
EXACTLY THESE STORMS WILL OCCUR. THEREFORE...COULD NOT LEAN THE POPS
ONE WAY OR ANOTHER GEOGRAPHICALLY IN THE FORECAST AREA DURING THIS
PACKAGE ISSUANCE. REGARDLESS...ANY CONVECTION THAT DOES OCCUR
COULD STILL POSE A FLOOD THREAT...IN ADDITION TO ISOLATED HAIL AND
DAMAGING WINDS SHOULD STORMS BECOME INTENSE. TONIGHT`S SEVERE
PROBABILITY APPEARS LOW AT THIS TIME. THEREFORE WILL ONLY HIGHLIGHT
THE FLOODING THREAT IN THE HWO FOR THIS TIME PERIOD.
A COLD FRONT WILL APPROACH THE REGION ON WEDNESDAY. THIS WILL HELP
TO INCREASE SHEAR ACROSS OUR AREA AND ENHANCE THUNDERSTORM
DEVELOPMENT. ALTHOUGH 0-6 KM SHEAR WILL ONLY BE AROUND 30 KT...THIS
WOULD BE SUFFICIENT FOR SOME SEVERE STORMS TO DEVELOP. IF THIS
DOES OCCUR...THE MAIN THREAT FROM THESE STORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. THIS SEVERE THREAT WILL BE HIGHLIGHTED IN
THE HWO FOR THE WEDNESDAY INTO WEDNESDAY NIGHT TIME PERIOD. BY
LATE WEDNESDAY NIGHT...CONVECTION WILL SHIFT SOUTHEAST OF OUR AREA
AHEAD OF A COLD FRONT.
HIGH PRESSURE WILL BUILD EASTWARD ACROSS OUR REGION ON
THURSDAY...BRINGING TO THE AREA A DRIER AND MORE STABLE AIRMASS.
EXPECT FAIR CONDITIONS BOTH THURSDAY AND THURSDAY NIGHT. TEMPERATURES
THURSDAY WILL BE IN THE LOW 80S. EXPECT SEASONABLY COOL LOWER 60S
THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
REGION WILL FIND ITSELF SPLIT BY A CDFNT AT THE BEGINNING OF THE
PERIOD. THE FRONT WILL BE LOCATED NEAR THE OHIO RIVER AT 12Z
THURSDAY. MODELS QUICKLY PUSH THE FRONT INTO THE APPALACHIANS AND
REPLACE IT WITH HIGH PRESSURE. THIS SHOULD MEAN SOME LINGERING
CONVECTION FOR THE MORNING HOURS OF THURSDAY IN THE EXTREME
SOUTH...WITH DRY CONDITIONS FOR THE N. MODELS DROP AN H5 S/W INTO
LAKE ERIE THURSDAY AFTN...BUT RIGHT NOW IT APPEARS THAT THE S/W WILL
PRODUCE JUST SOME AFTN CLOUDS AND NOT ANY AFTN SHOWERS.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND WILL HOLD CONTROL
INTO SATURDAY NIGHT. THIS SHOULD ALLOW THE REGION TO BEGIN TO DRY
OUT.
RETURN FLOW BY SUNDAY WILL BRING THE RETURN OF SCT CONVECTION FOR
SUNDAY AND MONDAY. WENT WITH LOW CHC POPS FOR NOW.
HIGHS THURSDAY INTO SATURDAY WILL BE A FEW DEGREES EITHER SIDE OF 80
FOR THE REGION. BY SUNDAY AND MONDAY...HIGHS WILL RISE INTO THE
LOWER 80S. LOWS WILL BE IN THE LOWER 60S FOR THE FIRST HALF OF THE
PERIOD...THEN THE MID 60S FOR THE LATER HALF.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
SHOWERS AND THUNDERSTORMS ARE CONTINUING TO SAG SOUTHEAST ACROSS
CENTRAL OHIO. THERE DOES APPEAR TO BE SOMEWHAT OF A BACK EDGE TO
IT THOUGH WITH JUST SOME VERY SPOTTY SHOWERS FARTHER BACK TO THE
NORTHWEST. THE LATEST RUC AND HRR ARE BOTH SUGGESTING SOME
ADDITIONAL REDEVELOPMENT ACROSS CENTRAL OHIO THROUGH
DAYBREAK. THE 00Z ARW IS ALSO SUGGESTING SOME REGENERATION...BUT
KEEPING IT NORTH OF THE TAF SITES. AS A RESULT...KCMH/KLCK MAY
REMAIN ALONG OR NEAR THE EDGE OF THIS THROUGH DAYBREAK.
MEANWHILE...SHOWERS ARE POPPING UP ACROSS SOUTHERN INDIANA AND
THE GLOBAL MODELS ARE INDICATING SOME OF THESE WILL SAG DOWN TOWARD
KCVG/KLUK THROUGH DAYBREAK. QUITE A BIT OF MODEL VARIANCE AS TO
WHAT WILL OCCUR LATER TODAY INTO TONIGHT. WILL TRY TO ALLOW FOR A
LULL IN THE PCPN FROM LATE MORNING INTO EARLY AFTERNOON...BUT
CONFIDENCE IN THIS IS NOT VERY HIGH AS SOME OF THE HI RES MODELS ARE
HINTING AT PCPN LINGERING THROUGH MUCH OF THE DAY...ESPECIALLY
ACROSS OUR NORTH. HOWEVER...THINK BETTER CHANCE FOR THUNDERSTORMS
WILL BE LATER IN THE DAY AS WE DESTABILIZE THROUGH THE AFTERNOON.
THINK BEST CHANCE FOR REDEVELOP MET WILL BE ALONG A REMNANT
BOUNDARY THAT WILL LIKELY BE ALONG THE I 70 CORRIDOR BY LATE
AFTERNOON...WITH PCPN THEN SAGGING SOUTH TOWARD THE OHIO RIVER
THROUGH THE EVENING.
OUTLOOK...GOOD CHANCE OF THUNDERSTORMS WEDNESDAY AND WEDNESDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 10 AM EDT THIS MORNING FOR OHZ026-034-
035-042>046-051>056-060>065-073-074.
KY...NONE.
IN...FLASH FLOOD WATCH UNTIL 10 AM EDT THIS MORNING FOR INZ050-058-
059.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...LATTO
SHORT TERM...LATTO
LONG TERM...SITES
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
135 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN A CONTINUED
CHANCE OF THUNDERSTORMS THROUGH MID WEEK. A COLD FRONT WILL PUSH
THROUGH THE AREA WEDNESDAY NIGHT. BUILDING HIGH PRESSURE IN THE
UPPER MIDWEST BEHIND THE FRONT WILL BRING DRIER CONDITIONS FOR
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HAVE BECOME INCREASINGLY CONCERNED ABOUT HEAVY RAIN/FLASH FLOOD
POTENTIAL FOR THE OVERNIGHT HOURS ACROSS THE NORTHERN HALF OF THE
FORECAST AREA. MODELS ARE SHOWING A LOW LEVEL JET ACROSS NORTHERN
OHIO THAT KEEPS AN AXIS OF MOISTURE TRANSPORT ACROSS THE REGION
THROUGH THE NIGHT. GUIDANCE HAS BEEN DEVELOPING AN EAST-WEST LINE
OF PRECIPITATION WHICH ONCE IT SETS UP MAY NOT MOVE MUCH AS IT
BECOMES PARALLEL TO THE 0-3 KM SHEAR VECTOR. ALTHOUGH IT SHOULD BE
NOTED THAT SOME RECENT RUNS OF THE HRRR AND RAP SUGGEST THAT THE
CONVECTIVE LINE MAY BE ABLE TO SAG SOUTH. ALSO THE WARM CLOUD
DEPTH IS DEEP WHICH WILL MAKE FOR VERY EFFICIENT RAINFALL
PRODUCTION. SOME OF THE REGION ALREADY HAD HEAVY RAINFALL EARLY
MONDAY MORNING WHICH SATURATED THE GROUND. ALL OF THIS SUGGESTS
THAT THERE IS A SUBSTANTIAL THREAT OF FLASH FLOODING AND IT IS
POSSIBLE THAT SOME LOCATIONS COULD SEE SIGNIFICANT IMPACTS
OVERNIGHT. THUS HAVE EXPANDED THE FLASH FLOOD WATCH BACK WEST TO
INCLUDE MOST OF THE MIAMI VALLEY AND PARTS OF THE WHITEWATER
VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
MODELS ARE IN DISAGREEMENT WITH THE EVOLUTION OF THE RAIN FROM
TONIGHT. CANNOT REMOVE A CHANCE FOR THUNDERSTORMS IN AN AIRMASS
THAT HAS BEEN EXTREMELY SUPPORTIVE OF THEM FOR THE PAST WEEK OR
MORE. HEAVY RAIN WILL BE A POSSIBILITY WITH ANY OF THESE
STORMS...AND THE CHANCES WILL REALLY INCREASE LATE WEDNESDAY AND
OVERNIGHT AS A DISTINCT COLD FRONT WITH UPPER LEVEL SUPPORT
CROSSES THE AREA. UNTIL THIS TIME...MORE OF THE SAME IS EXPECTED
AND HIGHS WILL GRADUALLY CREEP UPWARDS A DEGREE OR TWO EACH DAY.
NIGHTTIME LOWS WILL ONLY BE MITIGATED TO BE COOLER FROM STORMS
THAT MAY OR MAY NOT BE PRESENT AT TIMES...AT LEAST TUESDAY NIGHT.
OUTSIDE OF THE STORMS...THE AIRMASS WILL RETAIN HIGH DEWPOINTS AND
LIMIT NIGHTTIME DROPOFFS MUCH BELOW 70 DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
REGION WILL FIND ITSELF SPLIT BY A CDFNT AT THE BEGINNING OF THE
PERIOD. THE FRONT WILL BE LOCATED NEAR THE OHIO RIVER AT 12Z
THURSDAY. MODELS QUICKLY PUSH THE FRONT INTO THE APPALACHIANS AND
REPLACE IT WITH HIGH PRESSURE. THIS SHOULD MEAN SOME LINGERING
CONVECTION FOR THE MORNING HOURS OF THURSDAY IN THE EXTREME
SOUTH...WITH DRY CONDITIONS FOR THE N. MODELS DROP AN H5 S/W INTO
LAKE ERIE THURSDAY AFTN...BUT RIGHT NOW IT APPEARS THAT THE S/W WILL
PRODUCE JUST SOME AFTN CLOUDS AND NOT ANY AFTN SHOWERS.
HIGH PRESSURE WILL BUILD IN THURSDAY NIGHT AND WILL HOLD CONTROL
INTO SATURDAY NIGHT. THIS SHOULD ALLOW THE REGION TO BEGIN TO DRY
OUT.
RETURN FLOW BY SUNDAY WILL BRING THE RETURN OF SCT CONVECTION FOR
SUNDAY AND MONDAY. WENT WITH LOW CHC POPS FOR NOW.
HIGHS THURSDAY INTO SATURDAY WILL BE A FEW DEGREES EITHER SIDE OF 80
FOR THE REGION. BY SUNDAY AND MONDAY...HIGHS WILL RISE INTO THE
LOWER 80S. LOWS WILL BE IN THE LOWER 60S FOR THE FIRST HALF OF THE
PERIOD...THEN THE MID 60S FOR THE LATER HALF.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
SHOWERS AND THUNDERSTORMS ARE CONTINUING TO SAG SOUTHEAST ACROSS
CENTRAL OHIO. THERE DOES APPEAR TO BE SOMEWHAT OF A BACK EDGE TO
IT THOUGH WITH JUST SOME VERY SPOTTY SHOWERS FARTHER BACK TO THE
NORTHWEST. THE LATEST RUC AND HRR ARE BOTH SUGGESTING SOME
ADDITIONAL REDEVELOPMENT ACROSS CENTRAL OHIO THROUGH
DAYBREAK. THE 00Z ARW IS ALSO SUGGESTING SOME REGENERATION...BUT
KEEPING IT NORTH OF THE TAF SITES. AS A RESULT...KCMH/KLCK MAY
REMAIN ALONG OR NEAR THE EDGE OF THIS THROUGH DAYBREAK.
MEANWHILE...SHOWERS ARE POPPING UP ACROSS SOUTHERN INDIANA AND
THE GLOBAL MODELS ARE INDICATING SOME OF THESE WILL SAG DOWN TOWARD
KCVG/KLUK THROUGH DAYBREAK. QUITE A BIT OF MODEL VARIANCE AS TO
WHAT WILL OCCUR LATER TODAY INTO TONIGHT. WILL TRY TO ALLOW FOR A
LULL IN THE PCPN FROM LATE MORNING INTO EARLY AFTERNOON...BUT
CONFIDENCE IN THIS IS NOT VERY HIGH AS SOME OF THE HI RES MODELS ARE
HINTING AT PCPN LINGERING THROUGH MUCH OF THE DAY...ESPECIALLY
ACROSS OUR NORTH. HOWEVER...THINK BETTER CHANCE FOR THUNDERSTORMS
WILL BE LATER IN THE DAY AS WE DESTABILIZE THROUGH THE AFTERNOON.
THINK BEST CHANCE FOR REDEVELOP MET WILL BE ALONG A REMNANT
BOUNDARY THAT WILL LIKELY BE ALONG THE I 70 CORRIDOR BY LATE
AFTERNOON...WITH PCPN THEN SAGGING SOUTH TOWARD THE OHIO RIVER
THROUGH THE EVENING.
OUTLOOK...GOOD CHANCE OF THUNDERSTORMS WEDNESDAY AND WEDNESDAY
NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 10 AM EDT THIS MORNING FOR OHZ026-034-
035-042>046-051>056-060>065-073-074.
KY...NONE.
IN...FLASH FLOOD WATCH UNTIL 10 AM EDT THIS MORNING FOR INZ050-058-
059.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
439 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL PERSIST UNTIL A
COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 4 PM THIS AFTERNOON/...
BROAD SHORT WAVE TROUGH WHICH SEEMS UNDERDONE BY THE MDLS IS
DROPPING ESE FROM OHIO EARLY THIS MORNING. MID LEVEL WINDS
INCREASE FROM THE SW SLIGHTLY THIS MORNING...AND MOISTURE POOLING
AT THE AXIS OF THE TROUGH WILL SLIDE ACROSS THE CWA FROM W-E AS
MAINLY LIGHT SHOWERS AND WIDELY SCT/EMBEDDED THUNDER. HEAVIER RAIN
ON A TRACK TO MOVE TO THE SOUTH OF THE AREA. HRRR SEEMS TO HAVE A
GOOD HANDLE ON RECENT TRENDS. IT PORTRAYS THE DEATH OF MUCH OF
THIS FIRST BATCH OF LIGHT RAIN AS IT MOVES TO THE EAST...THEN A
RE-DEVELOPMENT OF CONVECTION AS DAYTIME HEATING COMBINES WITH
BREAKS IN THE CLOUD COVER TO BUBBLE UP SHRA/TSRA. WITH CLOUDS AND
SCT/NMRS SHOWERS AROUND...WILL KEEP MAXE TEMPS LOOKING LIKE
YESTERDAY/MON. DEWPOINTS ALSO MOVE LITTLE SO ANOTHER SEASONAL JULY
DAY IS IN STORE.
&&
.SHORT TERM /4 PM THIS AFTERNOON THROUGH 6 PM WEDNESDAY/...
THE SHORT WAVE PUSHES TO THE EAST THIS EVENING AND A DECREASE IN
SHRA/TSRA IS EXPECTED FOR MOST OF THE OVERNIGHT HOURS. WILL JUST
LEAVE IN SCT/ISOLD WORDING FOR NOW. HEIGHTS DROP THROUGH THE
NIGHT...THOUGH. THIS OCCURS AS A BROADER AND MORE-SYNOPTIC SCALE
TROUGH AXIS NEARS FROM THE GREAT LAKES/UPPER MIDWEST. THE MOISTURE
PLUME PUSHES RIGHT BACK INTO THE AREA LATE TONIGHT AND HANGS OUT
OVERHEAD THROUGH THE END OF THE PERIOD. A COOL FRONT REACHES THE
LOWER LAKES LATE WED. ALL THIS PUTS THE AREA IN THE WARM SECTOR
AND ALLOWS THE SERN COS TO MAKE ANOTHER RUN AT 90F. THE CLOUDS
WILL BE THE TEMPERING FACTOR ON WEDNESDAY...KNOCKING A FEW DEGS
OFF THE POTENTIAL MAXES. THEY WILL ALSO PLAY A ROLE IN THE
POTENTIAL FOR SEVERE WEATHER ON WEDNESDAY AFTN/EVENING. CAPES O/O
OF 2000 ARE POSSIBLE...BUT MAY NOT BE REALIZED. ALSO...WIND FIELD
IS NOT ALL THAT STRONG AS SPC POINTS OUT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
COOL FRONT SHOULD PUSH INTO THE AEA EARLY WED NIGHT AND MIGHT
CLEAR THE SERN COS BY THURSDAY SUNRISE. HOWEVER...POPS IN THE CHC
RANGE STILL A STRONG FORECAST FOR THE SERN HALF OF THE AREA LATE WED
NIGHT AND ALL THURS DUE TO UNCERTAINTY OF HOW FAR S THE DRIER AIR
WILL BE ABLE TO NUDGE THE CONVECTION.
MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE CONTINUES TO ADVERTISE
ANOTHER ANOMALOUS MERIDIONAL LARGE SCALE PATTERN EARLY IN THE
PERIOD...AS TROUGHING/UPPER LOW DROPS SOUTHWARD ALONG/WEST OF THE
APPALACHIANS...AND FOUR CORNERS RIDGE MAINTAINS ITS POSITION. THE
AMPLIFIED FLOW OVER THE CONUS SHOULD EVOLVE AND REVERT BACK TO A
MORE TYPICAL SUMMERTIME CONFIGURATION DURING THE SECOND HALF OF
THE PERIOD...AS THE JET STREAM RETREATS NORTHWARD TO THE
U.S./CANADIAN BORDER AND LARGE SUBTROPICAL RIDGE TAKES UP
RESIDENCE OVER MUCH OF THE LOWER 48.
IN TERMS OF SENSIBLE WX IMPACTS...A SURGE OF MUCH DRIER/BELOW NORMAL
PWAT AIR SHOULD FOLLOW BEHIND THE COLD FROPA ON THURSDAY. THIS
SHOULD PROVIDE A BRIEF BREAK IN THE HUMID/MUGGY CONDITIONS LATER
THIS WEEK. THE FRONTAL BOUNDARY APPEARS TO STALL-OUT OVER THE SRN
MID-ATLC STATES BEFORE DRIFTING BACK TO THE WEST TOWARD THE
APPALACHIANS...INTERCEPTING A MODEST /NEAR-NORMAL PWATS/ MOISTURE
FLOW AROUND THE BERMUDA HIGH. AS SUCH...LOOK FOR TEMPERATURES AND
TREND UPWARD INTO NEXT WEEK ACCOMPANIED BY RETURNING SUMMERTIME
HUMIDITY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LATE EVENING RADAR LOOP SHOWS A DWINDLING AREA OF SHRA ACROSS THE
SUSQ VALLEY IN VICINITY OF A DEPARTING UPPER LVL LOW PRES SYSTEM.
JUST A SLIGHT CHC OF A BRIEF VSBY REDUCTION FROM THESE SHRA THRU
04Z AT IPT...MDT AND LNS. BRIEF CLEARING AHEAD OF NEXT LOW PRES
SYSTEM COULD RESULT IN SOME FOG AFTER MIDNIGHT...MAINLY IN THOSE
LOCATIONS THAT RECEIVED RAIN EARLIER THIS EVENING...SUCH AS UNV.
NEXT LOW PRES SYSTEM APPROACHING FROM THE GRT LKS WILL LIKELY
BRING ANOTHER ROUND OF SHRA TO THE AREA EARLY TUE AM. THICKENING
CLOUD COVER AHEAD OF THIS FEATURE SHOULD PUT A BREAK ON THE
RADIATIONAL COOLING AND FOG FORMATION AFTER ABOUT 06Z-08Z.
HOWEVER...MVFR VSBYS STILL POSSIBLE LATE TONIGHT IN ANY HEAVIER
SHOWERS.
MODEL GUIDANCE SUGGESTS LOW PRES TROUGH AND ASSOC SHOWERS WILL
IMPACT THE ENTIRE AREA LATE TUE AM WITH LIMITED RESTRICTIONS. A
MOIST SW FLOW ASCENDING THE NW MTNS COULD PRODUCE SOME PERSISTENT
MVFR CIGS AT BFD BTWN 12Z-18Z TUESDAY. ELSEWHERE...PREDOMINANTLY
VFR CONDS ARE LIKELY BY NOON. HOWEVER...ISOLD LATE DAY THUNDERSTORM
IMPACTS ARE POSSIBLE IN ASSOCIATION WITH LINGERING TROUGH OF LOW
PRES OVR THE AREA.
OUTLOOK...
WED...AM LOW CIGS POSS NW MTNS. SCT TSRA IMPACTS POSSIBLE.
THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSSIBLE.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
1222 AM CDT TUE JUL 9 2013
.DISCUSSION...
SEE 06 AVIATION DISCUSSION BELOW.
&&
.AVIATION...
GUSTY SOUTH TO SOUTHEAST WINDS WILL DIMINISH IN STRENGTH OVER THE
NEXT FEW HOURS. WINDS WILL ONCE AGAIN BECOME GUSTY AT MOST
LOCATIONS MID MORNING TUESDAY. THERE IS A SLIGHT POSSIBILITY OF
MVFR CEILINGS AT MAF AND FST FOR EARLY TUESDAY MORNING BUT
CONFIDENCE REMAINS LOW.
&&
PREV DISCUSSION... /ISSUED 229 PM CDT MON JUL 8 2013/
DISCUSSION...
AN UPPER LEVEL DISTURBANCE PASSING BY TO THE SOUTH ACROSS THE BIG
BEND COULD GENERATE ISOLATED THUNDERSTORMS THIS EVENING ACROSS
WEST TEXAS PER CUMULUS FIELD AND LATEST RUC GUIDANCE. ANY ACTIVITY
SHOULD DIE THIS EVENING WITH LOSS OF HEATING. THIS DISTURBANCE
IS FORECAST TO CONTINUE TO SLOWLY TRACK WESTWARD ACROSS NORTHERN
MEXICO TUESDAY AND TUESDAY EVENING WITH ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS POSSIBLE AGAIN ACROSS THE BIG BEND...DAVIS
MOUNTAINS AND LOWER TRANS PECOS REGION CLOSEST TO THE TRACK OF
DISTURBANCE. BEYOND TUESDAY A SPRAWLING UPPER LEVEL HIGH PRESSURE
AREA ACROSS THE PLAINS AND ROCKIES SHOULD REGAIN FIRM CONTROL OF
THE REGION AND PRECIPITATION CHANCES WILL BE VERY LOW. THE NEXT
CHANCE OF CONVECTION APPEARS TO BE NEXT SUNDAY AND MONDAY AS
ANOTHER DISTURBANCE TRACKS WESTWARD ACROSS THE GULF AND MEXICO.
HIGH TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL THROUGH WEDNESDAY
WITH ABOVE NORMAL TEMPERATURES EXPECTED THURSDAY THROUGH SATURDAY.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1121 PM PDT Mon Jul 8 2013
.SYNOPSIS...
A weather system passing through the Inland Northwest today will
promote scattered showers and thunderstorms across the northern
mountains of Washington and Idaho, as well as southeast
Washington. Tuesday and Wednesday will be the warmest days this
week with high temperatures in the upper 80s to mid 90s. Thursday
through Saturday will be occasionally breezy with temperatures
pretty close to average, or slightly below. Low shower and
thunderstorms chances will linger near the mountains, especially
closer to the Canadian border, but otherwise conditions will be
dry. Temperatures begin to warm up again slightly going into early
next week.
&&
.DISCUSSION...
This Afternoon and Evening: The weather over northeast Washington
and the Idaho Panhandle will be active. Scattered thunderstorms
are expected through early this evening. Our concern area extends
from the Okanogan Highlands through northeast Washington into the
northern and central Idaho Panhandle. The 2 PM visible imagery
shows a mid-level atmospheric circulation in far southeast British
Columbia slowly moving east. Around this circulation the
atmosphere has become increasingly unstable with the RUC analysis
indicating 500 to 1000 J/KG of surface based CAPE from Republic to
Sandpoint to Spokane to Kellogg. Very little convective inhibition
remains, so look for convection to continue to develop through
late afternoon. Shear and buoyancy values suggest the potential
for organized multi-cell thunderstorms. Our main threat through 6
PM will be the potential for hail, heavy rain, and gusty winds. A
couple severe thunderstorm warnings may be needed, but most of the
cells through early evening will probably pulse up, produce hail
up to dime size, then pulse down. The threat for thunderstorms
should dissipate quickly early this evening as the upper level
support (upper low in SE BC) moves east of the region focusing the
threat over Montana.
Tuesday: A shortwave ridge of high pressure will replace the
trough over the Inland Northwest for Tuesday. Look for relatively
light winds, clear skies and temperatures 5 to 8 degrees above
average. /GKoch
Tuesday night through Thursday evening...General long-wave trof
lingers overhead but the air-mass contained in it is not very
unstable and does not have much moisture tied to any discrete
feature traversing through it. As thus for the most part a dry
forecast remains, with exception being minimal chance for
afternoon/evening mountain thunderstorms up North and over the
Idaho Panhandle Thursday afternoon and evening. Forecast
temperatures remain just slightly on the warm side of what would
be considered normal for this time of year. Other shortwave
features of note will be a dry disturbance passage on Wednesday
afternoon and evening which will increase the wind some but only
to low breezy category at most. /Pelatti
Thursday night through Monday: The Inland Northwest remains in a
more active pattern through the week`s end, before high pressure
starts to nudge in Sunday and Monday. A shortwave system continues
to slip through Idaho into Montana Thursday night, even as a
second shortwave begins to move toward the Cascades. That second
shortwave slips across eastern Washington and north Idaho through
Friday, with a third wave slipping by Saturday before high
pressure begins to nudge in Saturday night. Models continue to
disagree over some of the details. Yet the progression of these
features will bring some shower and thunderstorm chances to the
region. The main chances remain around the northern mountains.
Smaller chances will be found across the Blue Mountains through
the Central Panhandle, including the Palouse as the wave is
exiting Thursday night. While some of these waves are depicted as
being somewhat dynamic/strong, models still do not depict
significant instability and keep the deeper moisture southeast of
the region. So regardless of timing and track, fuel for showers is
not impressive. Thus over PoPs remain slight or isolated in
nature. Look for occasional breezy conditions, especially Friday,
with the passage of these waves. Although a couple models skim
another wave by southern BC, near the WA/ID border early next
week, drier conditions are forecast going into Sunday and Monday.
Look for slightly cooler than normal conditions around the end of
the work week, before temperatures warm closer to or slightly
above seasonal norms going into early next week. /J. Cote`
&&
.AVIATION...
06Z TAFS: Periods of thin high clouds moving through overnight
otherwise VFR and light winds for the next 24 hrs.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 58 89 60 89 59 83 / 0 0 0 0 0 10
Coeur d`Alene 56 87 58 87 58 83 / 10 0 0 0 0 10
Pullman 53 87 55 88 55 82 / 0 0 0 10 10 10
Lewiston 62 95 64 95 63 90 / 0 0 0 10 10 10
Colville 53 90 56 92 56 86 / 10 0 0 0 0 10
Sandpoint 50 85 53 86 54 82 / 20 0 0 0 0 10
Kellogg 54 87 57 87 58 82 / 10 0 0 0 10 10
Moses Lake 60 94 62 94 60 87 / 0 0 0 0 0 0
Wenatchee 64 92 65 91 62 85 / 0 0 0 0 0 0
Omak 60 94 60 92 59 86 / 0 0 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CDT TUE JUL 9 2013
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 315 AM CDT TUE JUL 9 2013
MAIN CONCERN WILL BE TRACK OF PLAINS THUNDERSTORM COMPLEX THIS
MORNING/TODAY...THEN SEVERE POTENTIAL GOING THIS AFTERNOON.
LOOP OF WATER VAPOR IMAGERY THIS MORNING ALONG WITH RAP 500MB
ANALYSIS SHOWS A FAIRLY VIGOROUS MID-LEVEL TROUGH MOVING OUT OF MT
INTO THE DAKOTAS...WHILE ANOTHER WEAKER WAVE WAS NOTED ACROSS
CENTRAL NEB. 925-850MB MOISTURE TRANSPORT AHEAD OF THESE WAVES WAS
PRODUCING A BROKEN LINE COMPLEX OF THUNDERSTORMS EXTENDING FROM
EASTERN ND/SD...INTO EASTERN NEB. THIS COMPLEX OF STORMS WAS MOVING
EAST AT 30-35KT...MAKING INROADS TOWARD THE AREA. SIMPLE
EXTRAPOLATION BRINGS THIS COMPLEX INTO SOUTHEAST MN/NORTHEAST IA
AROUND 12Z/7AM-ISH.
ARX/HRRR/NMM WRF MODELS DID A PRETTY GOOD JOB INITIALIZING THIS
CONVECTION AND REMAIN IN FAIRLY DECENT AGREEMENT THROUGH THE DAY
TODAY. HAVE TRENDED THE FORECAST TO MATCH UP WITH A BLEND OF THESE
SOLUTIONS. APPEARS THE COMPLEX OF STORMS WILL MAINTAIN
ITSELF...COMING ACROSS THE AREA THIS MORNING AS 925-850MB MOISTURE
TRANSPORT INCREASES/NOSES INTO THE REGION. THIS COMPLEX OF STORMS
HAS A HISTORY OF 30-50KT WINDS ASSOCIATED WITH IT OVER SD.
SO...CANNOT RULE OUT SOME BORDERLINE SEVERE WINDS AS IT ROLLS INTO
OUR AREA. COULD BE INTERESTING GOING INTO THIS AFTERNOON AS THE WRF
MODELS SHOW THIS COMPLEX DEVELOPING A FAIRLY SIGNIFICANT MCV
STRUCTURE. THIS IN TURN HAS THE POTENTIAL OF PRODUCING A
MINI-OUTFLOW/COLD FRONT ON ITS SOUTHWEST FLANK IN THE 18-21Z TIME
FRAME. WITH AMPING SHEAR IN THE 30-40KT RANGE DUE TO THE MCV AND
MORE THAN AMPLE CAPE IN THE 4000-5500J/KG RANGE...LOOKING FOR THE
POSSIBILITY OF A LINE OF SEVERE STORMS WITH DAMAGING WINDS DEVELOPING
ACROSS CENTRAL/SOUTHWEST WI THIS AFTERNOON. THIS OF COURSE WILL ALL
DEPEND ON HOW MUCH CLOUD IS PRESENT WHICH COULD AFFECT THE AMOUNT OF
AVAILABLE INSTABILITY REALIZED. THE POTENTIAL IS DEFINITELY THERE AND
WILL HAVE TO BE WATCHED CLOSELY. ANOTHER THING TO WATCH IS HEAVY
RAINFALL POTENTIAL WITH MUGGY AIRMASS IN PLACE AND PRECIPITABLE WATER
IN THE 2-2.25 INCH RANGE. THIS COULD AID IN TORRENTIAL DOWNPOURS OUT
OF THE STORMS AND SOME LOCALIZED PONDING OF WATER IN POOR DRAINAGE
AREAS.
LOOKING FOR THE MAIN COLD FRONT TO THEN SLIDE SOUTHEAST ACROSS THE
AREA IN THE 00-06Z TIME FRAME. UNCERTAIN ON HOW THIS IS GOING TO
PLAY OUT WITH THE POTENTIAL FOR SEVERE STORMS ALREADY GOING THROUGH
THE AREA THIS AFTERNOON. ATMOSPHERE COULD BE FAIRLY STABILIZED
BEHIND THIS CONVECTION AND COLD FRONT COULD SLIP THROUGH WITH NO
CONVECTION. APPEARS HIGHEST POTENTIAL FOR EVENING CONVECTION MAY BE
ALONG AND NORTH OF I-94 WHERE BETTER 500-300MB PV-ADVECTION WILL
EXIST. EXPECTING COLD FRONT AND ASSOCIATED CONVECTION TO PUSH EAST OF
THE AREA AROUND DAYBREAK AS HIGH PRESSURE BUILDS IN FROM THE
DAKOTAS.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE JUL 9 2013
HIGH PRESSURE WILL PRODUCE VERY PLEASANT WEATHER CONDITIONS ACROSS
THE AREA WEDNESDAY AND THURSDAY. LOOK FOR HIGHS IN THE 75-80 DEGREE
RANGE ON WEDNESDAY AND UPPER 70S/LOWER 80S ON THURSDAY. MUCH LOWER
HUMIDITY LEVELS WILL ALSO BE NOTED AS DEWPOINTS HOVER IN THE 50S.
PLAN ON WARMER TEMPERATURES ON FRIDAY ALONG WITH INCREASING HUMIDITY
LEVEL AS THE HIGH SLIDES OFF TO THE EAST AND SOUTH WINDS SET UP
ACROSS THE AREA. LOOK FOR HIGHS IN THE 80S WITH A FEW READINGS
FLIRTING WITH THE 90 DEGREE MARK ACROSS SOUTHEAST MN.
EC/GFS ACTUALLY IN PRETTY GOOD AGREEMENT GOING INTO THE WEEKEND.
BOTH MOVE A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER REGION BY
SUNDAY MORNING...THEN HANG IT UP ACROSS WI INTO CENTRAL IA BY
MONDAY. THIS WILL PRODUCE A CHANCE OF SHOWERS AND THUNDERSTORMS FROM
FRIDAY NIGHT STRAIGHT THROUGH MONDAY. OTHERWISE...LOOK FOR
TEMPERATURES TO BE RIGHT AROUND NORMAL LEVELS IN THE 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT
1153 PM CDT MON JUL 8 2013
THE AVIATION FORECAST IS VERY UNCERTAIN FOR THE NEXT 24 HOURS...
PARTICULARLY WITH THUNDERSTORMS. SKIES ARE MAINLY CLEAR AT THE TAF
SITES AS OF 056Z. WITH DEWPOINTS STILL SITTING UP AROUND 70F AND
TEMPERATURES COOLING...ANTICIPATING MVFR BR TO FORM AROUND 09Z.
TO THE WEST...CLUSTERS OF SHOWERS AND THUNDERSTORMS ARE PRESENT
ACROSS THE DAKOTAS INTO NEBRASKA. THESE ARE DEVELOPING AND MOVING
SLOWER THAN PREVIOUS COMPUTER MODELS HAVE FORECAST...THUS HAVE
DELAYED THE TIMING OF THEM IMPACTING THE TAF SITES EVEN MORE.
PRESENTLY HAVE THE SHOWERS AND STORMS IMPACTING RST BETWEEN 13-17Z
AND LSE BETWEEN 14-18Z. STILL NOT ENOUGH CONFIDENCE EXISTS TO
CHANGE THE VCTS TO -TSRA GIVEN THE POTENTIAL FOR THE THUNDERSTORMS
TO BE SCATTERED IN COVERAGE. CONTINUED TO SUGGEST A GENERAL BREAK
IN THE PRECIPITATION UNTIL A COLD FRONT APPROACHES DURING THE
EVENING. HOWEVER...WITH SOME COMPUTER MODELS SHOWING POTENTIAL FOR
SHOWERS AND STORMS TO LINGER THROUGH THE AFTERNOON...MAINTAINED A
VCSH. WITH THE COLD FRONT HAVE ADDED A PERIOD OF VCTS FOR ABOUT 4
HOURS. IT IS POSSIBLE THIS IS TOO LONG...BUT THERE ARE
UNCERTAINTIES ON THE TIMING AND IT DOES APPEAR THE FRONT SHOULD
HAVE SOME THUNDERSTORMS ON IT.
REGARDING THUNDERSTORM IMPACTS. THOSE DURING THE MORNING WILL
LIKELY KNOCK VISIBILITIES AND CEILINGS TO MVFR AND HAVE TO
POTENTIAL TO PRODUCE HEAVY RAIN. THOSE FOR THE EVENING COULD
PRODUCE STRONG TO SEVERE WIND GUSTS...ALONG WITH HEAVY RAIN AND
BRIEF VISIBILITY RESTRICTION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT MON JUL 8 2013
.UPDATE...
ISSUED AT 942 PM CDT MON JUL 8 2013
TRYING TO FIGURE OUT THE CONVECTIVE EVOLUTION FORECAST FROM THE
OVERNIGHT HOURS THROUGH TUESDAY REMAINS VERY PROBLEMATIC.
FIRST...A LINE OF SHOWERS AND THUNDERSTORMS SET UP JUST NORTH OF
US-20 AND NEAR THE CLAYTON/GRANT COUNTY LINE. THESE STORMS WERE
ALONG A QUASI-STATIONARY FRONTAL BOUNDARY AND AIDED BY MLCAPES OF
2000-2500 J/KG PER RAP ANALYSIS. THEY HAVE BEEN VERY EFFICIENT
RAIN PRODUCERS WITH RAINFALL RATES OF 1 TO 2 INCHES PER HOUR BEING
OBSERVED IN EDGEWOOD AND GREELEY IA. LACK OF ANY 0-6KM SHEAR HAS
RESULTED IN THE STORMS COLLAPSING. ADDITIONALLY...LOSS OF DAYTIME
HEATING ALLOWING THE CAPE TO DIMINISH...THOUGH DEWPOINTS UP IN
THE MID 70S POOLED ALONG THE BOUNDARY RESULTING IN A SLOW
DIMINISHMENT. ANTICIPATING THESE STORMS MAY END UP FALLING PART IN
THE NEXT HOUR.
NOW FOR THE OVERNIGHT INTO TUESDAY. CONVECTION ACROSS SOUTH DAKOTA
AND NEBRASKA HAS BEEN MUCH LESS THAN WHAT MANY MODELS UP TO THIS
POINT HAD SUGGESTED...INCLUDING HIGH RESOLUTION MODELS. THUS...THE
IDEA OF AN MCS ROLLING OUT OF THIS REGION AND IMPACTING THE
FORECAST AREA LATE TONIGHT IS VERY MUCH IN QUESTION. LOOKING AT
OBSERVATIONAL DATA...THERE IS A SHORTWAVE OVER SOUTHWEST SOUTH
DAKOTA INTO FAR WESTERN NEBRASKA WITH ISOLATED CONVECTION
ACCOMPANYING IT. AHEAD OF THE SHORTWAVE...850MB WINDS HAVE BEEN
INCREASING OVER KANSAS AND NEBRASKA PER RADAR/PROFILER DATA...WITH
HINTS OF A WARM FRONTAL ZONE ACROSS SOUTHERN NEBRASKA. THIS IS
SHOWN TOO IN LATEST SURFACE ANALYSIS. ONCE THESE FEATURES MEET
UP...LIKELY IN CENTRAL/EASTERN NEBRASKA...WOULD IMAGINE CONVECTION
WILL INCREASE THERE. THE CONVECTION WILL LIKELY HEAD EAST THROUGH
THE MEAN FLOW TOWARDS SOUTHERN SECTIONS OF THE FORECAST
AREA...UNLESS IT UPSCALES INTO AN MCS...WHICH THEN MAY HEAD
SOUTHEAST AWAY FROM THE AREA PER BOTH NORMAL CORFIDI VECTORS AND
PROPAGATING CORFIDI VECTORS.
HEADING INTO TUESDAY...THERE ARE INDICATIONS FROM THE 09.00Z
NAM/RAP...08.12Z ECMWF/REGIONAL CANADIAN AND 08.18Z GFS OF 850MB
MOISTURE TRANSPORT PICKING UP ACROSS CENTRAL IOWA...WITH THE NOSE
OF IT POINTED RIGHT INTO THE FORECAST AREA AT 18Z. THIS COULD
CONCEIVABLY INITIATE PLENTY OF CONVECTION FROM LATE MORNING
THROUGH A BULK OF THE AFTERNOON HOURS. THESE WOULD BE EFFICIENT
RAIN PRODUCERS GIVEN DEEP WARM CLOUD DEPTHS AND PRECIPITABLE WATER
VALUES UPWARDS OF 2 INCHES. IF THIS CONVECTION FORMS...BY THE TIME
THE COLD FRONT COMING THROUGH MINNESOTA APPROACHES THE FORECAST
AREA IN THE EVENING...WE MAY NOT HAVE ENOUGH INSTABILITY TO DO
MUCH WITH IT.
WE WILL JUST HAVE TO SEE HOW OVERNIGHT CONVECTION PLAYS
OUT...SINCE AN MCV GOING SOUTH OF US COULD PRODUCE ENOUGH
SUBSIDENCE TO PRECLUDE MUCH CONVECTION IN ITS WAKE FOR TUESDAY.
THE PRESENCE OF THE MCV WOULD LIKE DISTORT THE PROGGED 850MB
MOISTURE TRANSPORT ZONE TOO. TUESDAY THEN WOULD BE A VERY WARM DAY
AGAIN WITH HIGHS ABOVE CURRENT FORECAST...WITH SEVERE WEATHER
POTENTIAL IN THE EVENING AS THE COLD FRONT MOVES IN.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
WARM FRONT SLATED TO WAVER WEST-EAST ACROSS SOUTHERN IA TONIGHT/TUE.
THE LOW LEVEL JET/MOISTURE TRANSPORT FOCUSES INTO THE BOUNDARY
ACROSS CENTRAL IA TONIGHT...AND SHOWER/STORMS SHOULD DEVELOP AS A
RESULT. THE LOW LEVEL FORCING PUSHES NORTHEAST ACROSS THE FORECAST
AREA TUE MORNING WHILE A PIECE OF UPPER LEVEL ENERGY TRACKS FROM THE
NORTHERN PLAINS TO ACROSS THE UPPER MISSISSIPPI RIVER VALLEY BETWEEN
12-18Z. WOULD EXPECT TO SEE A SHIFT NORTHWARD WITH THE MORE
FAVORABLE CONVECTIVE REGION AS A RESULT...MOSTLY ALONG AND NORTH OF
I-90. A STRONGER UPPER LEVEL SHORTWAVE TROUGH PROGGED TO SLIP ACROSS
THE NORTHERN PLAINS AND INTO NORTHERN MN BY 00Z WED. A COLD FRONT
WILL SURGE AHEAD OF THIS SHORTWAVE...GETTING TO THE MISSISSIPPI
RIVER BY 00Z. THE GFS AND NAM BUILD 4000+ J/KG OF MUCAPE AHEAD OF
THE FRONT...WITH 40+ KTS OF 0-6 KM SHEAR. INSTABILITY WILL DEPEND ON
HOW LONG THE MORNING SHOWERS/STORMS LINGER ACROSS THE LOCAL
AREA...AND HOW QUICKLY THE DEBRIS CLOUDS CLEAR. AS IT STANDS...IF
PARAMETERS MANIFEST PER MODELED FORECAST...IT WOULD BE A GOOD SETUP
FOR SEVERE WEATHER. HOWEVER...IF PCPN LINGERS LINGERS...INSTABILITY
WILL BE MUCH LOWER...LESSENING THE SEVERE THREAT. A VERY CONDITIONAL
SEVERE WEATHER THREAT THAT WON/T BECOME CLEARER UNTIL THE AFTERNOON
HOURS.
HERE IS HOW TUE COULD PLAY OUT...MORNING CONVECTION ASSOCIATED WITH
THE LOW LEVEL JET ADVANCES NORTHEAST ACROSS THE REGION. COULD BE
SOME LINGERING SHOWERS/STORMS IN THE AFTERNOON...BUT ENVISION A
BREAK FROM THE WIDESPREAD PCPN CHANCES. SHOWERS/STORMS SPARK ALONG
AND AHEAD OF THE COLD FRONT BY LATE AFTERNOON/EVENING. MAYBE A
BETTER CHANCE NORTH OF I-94. ALSO...BELIEVE THE HIGHER SEVERE RISK
WILL BE DURING THIS TIME.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FROM
THE WEST ON WEDNESDAY...AND LOOKS TO BE THE MAIN WEATHER INFLUENCE
THROUGH THE BETTER PART OF FRIDAY. THE HEAT/HUMIDITY OF THE PAST FEW
DAYS WILL SWEEP EAST DURING THIS PERIOD...WITH COMPARATIVELY COOLER
AND LESS MUGGY CONDITIONS RESULTING.
AN UPPER LEVEL SHORTWAVE TROUGH IS THEN SLATED TO DRIVE FROM THE PAC
NW TO ACROSS SOUTHERN CANADA FOR THE UPCOMING WEEKEND. WHILE CURRENT
TRENDS FAVOR KEEPING MOST OF THE UPPER LEVEL ENERGY NORTH OF THE
FORECAST AREA...THE GFS AND ECMWF WOULD SLIDE AN ASSOCIATED COLD
FRONT ACROSS THE REGION. WITH THE WINDS FLIPPING TO THE SOUTH AS THE
HIGH EEKS TO THE EAST...LOW LEVEL MOISTURE WOULD INCREASE AHEAD OF
THE SFC BOUNDARY...AS WOULD INSTABILITY. EXPECT SOME CONVECTION
AROUND THE FRONT AS RESULT. DETAILS ON WHEN/WHERE ISN/T CLEAR AT
THIS TIME...WITH SOME MODEL DIFFERENCES ON TIMING AND PLACEMENT OF
THE RELEVANT FEATURES. THE SFC FRONT COULD THEN GET HUNG UP FROM
WEST TO EAST ACROSS THE REGION...SERVING AS A POSSIBLE SHOWER/STORM
FOCUS THROUGH THE WEEKEND. WILL LEAN ON THE CONSENSUS/EC SOLUTION
FOR PCPN CHANCES FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1153 PM CDT MON JUL 8 2013
THE AVIATION FORECAST IS VERY UNCERTAIN FOR THE NEXT 24 HOURS...
PARTICULARLY WITH THUNDERSTORMS. SKIES ARE MAINLY CLEAR AT THE TAF
SITES AS OF 056Z. WITH DEWPOINTS STILL SITTING UP AROUND 70F AND
TEMPERATURES COOLING...ANTICIPATING MVFR BR TO FORM AROUND 09Z.
TO THE WEST...CLUSTERS OF SHOWERS AND THUNDERSTORMS ARE PRESENT
ACROSS THE DAKOTAS INTO NEBRASKA. THESE ARE DEVELOPING AND MOVING
SLOWER THAN PREVIOUS COMPUTER MODELS HAVE FORECAST...THUS HAVE
DELAYED THE TIMING OF THEM IMPACTING THE TAF SITES EVEN MORE.
PRESENTLY HAVE THE SHOWERS AND STORMS IMPACTING RST BETWEEN 13-17Z
AND LSE BETWEEN 14-18Z. STILL NOT ENOUGH CONFIDENCE EXISTS TO
CHANGE THE VCTS TO -TSRA GIVEN THE POTENTIAL FOR THE THUNDERSTORMS
TO BE SCATTERED IN COVERAGE. CONTINUED TO SUGGEST A GENERAL BREAK
IN THE PRECIPITATION UNTIL A COLD FRONT APPROACHES DURING THE
EVENING. HOWEVER...WITH SOME COMPUTER MODELS SHOWING POTENTIAL FOR
SHOWERS AND STORMS TO LINGER THROUGH THE AFTERNOON...MAINTAINED A
VCSH. WITH THE COLD FRONT HAVE ADDED A PERIOD OF VCTS FOR ABOUT 4
HOURS. IT IS POSSIBLE THIS IS TOO LONG...BUT THERE ARE
UNCERTAINTIES ON THE TIMING AND IT DOES APPEAR THE FRONT SHOULD
HAVE SOME THUNDERSTORMS ON IT.
REGARDING THUNDERSTORM IMPACTS. THOSE DURING THE MORNING WILL
LIKELY KNOCK VISIBILITIES AND CEILINGS TO MVFR AND HAVE TO
POTENTIAL TO PRODUCE HEAVY RAIN. THOSE FOR THE EVENING COULD
PRODUCE STRONG TO SEVERE WIND GUSTS...ALONG WITH HEAVY RAIN AND
BRIEF VISIBILITY RESTRICTION.
&&
.HYDROLOGY...(TUESDAY)
ISSUED AT 250 PM CDT MON JUL 8 2013
PWS CLOSE TO 2 INCHES THROUGH TUE...AROUND 170 PERCENT OF
NORMAL...WHILE WARM CLOUD DEPTH IS 3500-4000 M. ALL SUPPORT THE
POTENTIAL FOR HEAVY RAIN. HOWEVER...THE EXPECTED PCPN LOOKS
TRANSITORY...NOT LINGERING NOR MUCH TRAINING....WHILE FFG IS 2.5-3
INCHES IN 3 HOURS. THE MOISTURE TRANSPORT ISN/T OVERLY STRONG NOR
DOES IT FOCUS FOR A PROLONGED PERIOD. SO...WHILE THE ATMOSPHERE
COULD SUPPORT HEAVY RAIN...OTHER ASPECTS MINIMIZE A FLASH FLOOD
THREAT. IF PCPN RATES COULD BECOME HIGH ENOUGH...FLASH FLOODING OR
URBAN/CITY FLOODING WOULD BE POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...AJ
HYDROLOGY....DAS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1132 PM CDT MON JUL 8 2013
.UPDATE...
ISOLATED THUNDERSTORMS CONTINUE TO POP-UP ALONG OUTFLOW BOUNDARIES
WITHIN REGION OF SURFACE MOISTURE FLUX CONVERGENCE OVER FAR SRN WI AND
NRN IL. RAPID UPDATE/HI-RES MODELS CONTINUE TO SHOW A DOWNWARD
TREND TO CONVECTION OVER THE REGION THROUGH THE NIGHT WITH THE
FOCUS SHIFTING TO MCS DEVELOPMENT CURRENTLY OCCURRING OVER THE
DAKOTAS MOVING EAST THROUGH IOWA/MINNESOTA AND REACHING WESTERN
WISCONSIN SOMETIME BETWEEN 12Z AND 18Z TUESDAY.
TIMING DIFFERENCE IS CRITICAL TO SEVERE POTENTIAL FOR TUESDAY AS
MCS TRACK WILL HAVE AN IMPACT ON LOCATION OF EFFECTIVE BOUNDARY.
PRECIPITATION TOO LONG INTO THE DAY AND/OR CLOUD DEBRIS COULD
REDUCE HEATING AND SUBSEQUENT INSTABILITY. OPERATIONAL MODELS
STILL LOOKING AT MAIN CONVECTIVE EVENT TO OCCUR LATE
AFTERNOON/EVENING AHEAD OF...AND WITH PASSAGE OF MAIN SHORT WAVE
TROUGH AND ASSOCIATED SURFACE COLD FRONT.
LIGHT FOG OVER MAINLY THE NORTHEAST THIRD OF FORECAST AREA...WHERE
LAKE BREEZE...ENHANCED BY OUTFLOW FROM EARLIER STORMS HAS COOLED
TEMPS TOWARD DEW POINTS THAT ARE LOWER THAN EARLIER IN THE DAY AS
WELL WITH SLIGHTLY DRIER AIR ADVECTING IN ON NE WINDS. RUC AND NAM
VISIBILITY FORECASTS HOLD CHANCES FOR 1/4 MILE TO THE EAST OF THE
KETTLE MORAINE..WITH THE LATEST NAM MOS GUIDANCE KEEPING VSBYS NO
LOWER THAN 1 TO 2 MILES. WILL KEEP PATCHY FOG FOR NOW AND SEE HOW
FOG DEVELOPS...THOUGH SBM IS DOWN TO 1/4 MILE.
&&
.AVIATION/06Z TAFS/...
EXPECT CURRENT DEVELOPING MVFR VSBYS TO FALL TO IFR IN FOG OVERNIGHT.
NOT EXPECTING LIFR...BUT WILL HAVE TO WATCH KENW FOR 1/2 MILE
VSBYS. DO NOT EXPECT MUCH MORE IN THE WAY OF CONVECTION UNTIL
APPROACH OF SHORT WAVE TROUGH AND SURFACE COLD FRONT TRAILING FROM
ATTENDANT SURFACE LOW CROSSING SRN CANADA TUESDAY. MODELS SUGGEST
AN MCS...OR ITS REMAINS...MOVING ACROSS SRN WI TUESDAY MORNING
INTO EARLY AFTERNOON...THEN THE SECOND ROUND WITH A BETTER CHANCE
OF SEVERE IN THE AFTERNOON AND EVENING WITH THE FRONT.
&&
.MARINE...
ADDED AREAS OF FOG IN THE NSH BASED ON SHORE BASED WEB CAMS JUST
BEFORE DARK AND WITH FOG PRODUCT SHOWING AN EXPANDING AREA OF LOW
STRATUS OVER MAINLY THE NORTHERN HALF OF THE LAKE. MODEL LOW-LAYER
WINDS SEEM TO FAVOR HOLDING THE LOW STRATUS OFF TO THE EAST...BUT WILL
HAVE TO BE WATCHED FOR POSSIBLE MARINE DENSE FOG ADVISORY IF IT
MOVES TO THE WESTERN SHORE. POSSIBLE THUNDERSTORMS IN THE LATE
MORNING/EARLY AFTERNOON WITH MCS...THEN SECOND ROUND OF STORMS
WITH THE BETTER POTENTIAL FOR SEVERE IN THE LATE AFTERNOON/EVENING.
&&
.PREV DISCUSSION... /ISSUED 305 PM CDT MON JUL 8 2013/
SHORT TERM...
TONIGHT - CONFIDENCE...MEDIUM
WARM/UNSTABLE AIRMASS HAS GENERATED A FEW SHRA ACROSS NE CWA THIS
AFTERNOON VICINITY OF INSTABILITY GRADIENT AND SURFACE FRONTOGENESIS
PER SPC MESO PAGE. OVERALL 500 MILLIBAR RIDGING SHOULD KEEP MOST
AREAS DRY FOR MUCH OF THE NIGHT. FOCUS SHIFTS BACK TO THE WEST WITH
THE NEXT SHORT WAVE APPROACHING. IN RESPONSE TO THE LOW LEVEL
CYCLOGENESIS...A STRENGTHENING LOW LEVEL JET WILL BRING ANOTHER
SURGE OF MOISTURE INTO THE UPPER MIDWEST. EXPECTING AN MCS TO
DEVELOP WEST OF WISCONSIN OVERNIGHT...AND PERHAPS AFFFECT THE SW CWA
LATE IN THE NIGHT. WARM AND HUMID CONDITIONS WILL PERSIST THROUGH
THE OVERNIGHT HOURS. MAV/MET AND SREF PROBS POINTING TO POTENTIAL
FOR FOG. IN FACT SOME RATHER LOW VSBYS FORECAST BY MOS. WITH THE
ABUNDANT LOW LEVEL MOISTURE...SOUTHWARD SAGGING FRONTAL
BOUNDARY...AND LIGHT WIND REGIME...WILL HAVE SOME FOG IN THE GRIDS
FOR LATER TONIGHT.
TUESDAY - CONFIDENCE...MEDIUM
COMPLEX DAY SETTING UP. THE MORNING WILL BE COMPRISED OF DEALING
WITH FOG TRENDS ALONG AND NORTH OF WHERE SURFACE BOUNDARY IS
SITUATED. IN ADDITION CONVECTION LIKELY ONGOING IN PARTS OF THE
AREA. AS THE MCS ARRIVES ANY FOG SHOULD GRADUALLY THIN OUT. THEN THE
WAITING GAME WILL START FOR RENEWED CONVECTIVE DEVELOPMENT AS THE
DAY WEARS ALONG. A MORE VIGOROUS SHORTWAVE WILL BE APPROACHING FROM
MN LATER IN THE DAY. DETAILS OF WHERE THE LOW LEVEL BOUNDARY SETS UP
WILL HAVE TO BE SORTED OUT AFTER MORNING CONVECTION...THOUGH
MAJORITY OF AVAILABLE GUIDANCE/CIPS ANALOGS AND SPC SWODY2 SUPPORT
STRONG/SEVERE STORMS REFIRING WITH A NOD TOWARDS DAMAGING WINDS AND
HEAVY RAINS. PROGGD ML CAPE VALUES/LI/S/PWS ARE ALL SUPPORTIVE OF
MODERATE TO STRONG INSTABILITY AND AN AIRMASS LOADED WITH MOISTURE.
SO STORMS WILL BE VERY EFFICENT RAIN PRODUCERS.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE HIGH.
THE MAIN MID/UPPER SHORTWAVE MOVES ACROSS LAKE SUPERIOR THURSDAY NIGHT
AND EXITS THE LAKE HURON AREA WEDNESDAY. SOUTHERN WISCONSIN IS IN THE
RIGHT ENTRANCE REGION OF AN 85 KNOT 250 MB JET TUESDAY EVENING.
THE UPPER FLOW IS DIFLUENT WITH WEAK TO MODERATE UPPER DIVERGENCE.
THE CWASP VALUES STILL APPROACH 65 PERCENT ON THE NAM DURING THE
AFTERNOON AND EVENING. ZERO TO 3 KM EHI VALUES ARE QUITE HIGH ACROSS
NORTHWEST ILLINOIS EARLY IN THE EVENING...WITH VALUES AROUND 5.
EHI VALUES ARE NEAR 2 TO 3 ACROSS MUCH OF SOUTH CENTRAL WISCONSIN
AND WESTERN PORTIONS OF SOUTHEAST WISCONSIN INDICATING SOME
TORNADO POSSIBILITY AS WELL. THE CIPS ANALOGS HAVE MAINLY SEVERE
WIND EVENTS...BUT THERE ARE SOME TORNADO EVENTS WITH
PROBABILITIES OF 2 TO 5 PCT WITHIN 40 KM OF A GRID POINT OVER MUCH
OF THE FORECAST AREA. MUCH WILL DEPEND ON WHETHER A MORNING
MESOSCALE CONVECTIVE COMPLEX MOVES ACROSS THE AREA...AND WHERE THE
RETURNING WARM FRONTAL BOUNDARY ENDS UP. THE COLD FRONT EXITS THE
FAR SOUTHEAST TUESDAY NIGHT. UNTIL THEN WITH CAPE VALUES AROUND
1500 J/KG IN THE EVENING...THE SEVERE AND HEAVY RAIN THREAT SHOULD
CONTINUE.
THE 850/700 MB THERMAL RIDGE DROPS SOUTH INTO ILLINOIS TUESDAY
NIGHT. DRYING OCCURS AT 850/700 MB AND SURFACE DEW POINTS DROP
INTO THE LOWER 60S WEDNESDAY AFTERNOON. THERE IS CONSIDERABLE
DRYING IN THE MID AND LOW LEVELS...WITH A STABLE LAYER AROUND 6 TO
10 THSD FT IN THE NAM FORECAST SOUNDINGS.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
THE SHORTWAVE REACHES SOUTHEAST CANADA AND THE EASTERN
GREAT LAKES...BUT SOUTHERN WISCONSIN IS STILL SOMEWHAT IN THE
CYCLONIC FLOW ON THE BACK SIDE OF THE TROUGH. ZERO TO 1 KM CAPE
VALUES REACH 600 J/KG THURSDAY AFTERNOON WITH STEEP LOW LEVEL
LAPSE RATES. HOWEVER MID LEVELS ARE VERY DRY AND WOULD LIKELY
LIMIT ANY DEEP MOIST CONVECTION DUE TO ENTRAINMENT.
THICKNESS VALUES DROP TO 564 TO 567 DECAMETERS AS A LARGE SURFACE
HIGH BUILDS INTO THE UPPER MISSISSIPPI VALLEY AND WISCONSIN.
LONG TERM...
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE HIGH.
THE UPPER TROUGH DROPS SOUTH ACROSS THE EASTERN U.S. WITH A LARGE
MID/UPPER RIDGE BUILDING FROM THE SOUTHERN ROCKIES INTO WISCONSIN.
THE SURFACE HIGH IS OVER THE GREAT LAKES AND UPPER OHIO RIVER
VALLEY. TEMPERATURES SHOULD BE ON THE REBOUND AND COULD RISE ABOVE
THE GFS MOS VALUES.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE UPPER TROUGH/LOW RETROGRADES INTO THE GULF COAST AREA WITH
THE LARGE RIDGE STILL FROM THE SOUTHERN ROCKIES INTO WISCONSIN.
THE SURFACE HIGH REMAINS IS OVER THE GREAT LAKES. WARM AIR
ADVECTION OCCURS FRIDAY NIGHT AND SATURDAY. BOTH THE 12Z GFS AND
00Z ECMWF HAS SOME PRECIPITATION OVER NORTHWEST WISCONSIN...BUT
ARE GENERALLY DRY AS IT APPROACHES SOUTHERN WISCONSIN SATURDAY...SO
JUST A SLIGHT CHANCE OF SHOWERS AT BEST MAINLY NORTHWEST OF
MADISON BY SATURDAY AFTERNOON.
MONDAY...FORECAST CONFIDENCE MEDIUM.
A SHORTWAVE MOVES ACROSS SOUTHERN CANADA WITH THE MID/UPPER RIDGE
EXTENDING MORE EAST TO WEST ACROSS THE MID SECTIONS OF THE U.S.
A WEAK COLD FRONT SHOULD MOVE ACROSS SOUTHERN WISCONSIN BUT MODEL
PRECIPITATION AMOUNTS ARE LIGHT.
AVIATION/00Z TAFS/...
ELONGATED FRONTAL BOUNDARY EXTENDS FROM NORTHERN LOWER MI THROUGH
CENTRAL WI INTO CENTRAL IOWA. PLENTY OF MVFR CU EXPECTED TO MOSTLY
DISSIPATE WITH LOSS OF HEATING. ISOLD SHRA WILL AFFECT LOCALES
MAINLY NORTH OF TAF SITES THIS EVE B4 DISSIPATING. MET/MAV MOS
DATA ALONG WITH SREF CIG/VSBY PROGS BEAR OUT CONCERN FOR LOW
CLOUDS/FOG WITH LIGHTER WIND REGIME EVOLVING TONIGHT INTO EARLY
WEDNESDAY WITH SOUTHWARD SAGGING FRONTAL BOUNDARY. CONVECTION
LIKELY TO REDEVELOP LATER TONIGHT INTO TUESDAY MORNING WITH
RENEWED LOW LEVEL JET AND APPROACH OF ANOTHER 500 MILLIBAR
SHORTWAVE. THEN A BREAK BEFORE MORE STORMS ARRIVE MID/LATE
AFTERNOON TIME FRAME INTO THE EVENING HOURS. SOME OF THE STORMS
MAY BECOME SEVERE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...HENTZ
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
1100 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK FRONT ACROSS SOUTHERN CONNECTICUT WILL GRADUALLY RETURN
NORTH THIS AFTERNOON. A WEAK TROUGH APPROACHES WEDNESDAY
AFTERNOON...WITH A SLOWLY MOVING FRONTAL SYSTEM AFFECTING THE
REGION THROUGH THE END OF THE WEEK. A COLD FRONT SLOWLY MOVES
THROUGH THE REGION WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND
THEN STALLS OFFSHORE. HIGH PRESSURE THEN TRIES TO BUILD INTO THE
REGION FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON LATEST RADAR IMAGERY AND OBS...A WEAK...DIFFUSE COLD FRONT
APPEARS TO HAVE PUSHED ACROSS SRN CT...WITH LOCAL SEA- AND SOUND-
BREEZES MAKING IT DIFFICULT TO PINPOINT THE EXACT LOCATION.
LATEST HRRR MODEL TAKES BOUNDARY SLOWLY NORTH THIS AFTERNOON WITH
CONVECTION BEING INITIATED ACROSS INTERIOR CT. ADDITIONAL SCT
CONVECTION WILL LIKELY FIRE UP WITH AN APPROACHING SHORT WAVE TROF
TO THE NORTH AND WEST OF NYC...BEFORE DISSIPATING NEAR THE COAST
EARLY THIS EVE. SEABREEZE BOUNDARY IS ALSO ANOTHER POTENTIAL
TRIGGER FOR CONVECTION. DUE TO WEAK STEERING WINDS FROM THE WEST
AT 10 KT OR LESS...ANY CONVECTION WILL BE CAPABLE OF BRIEF HEAVY
DOWNPOURS. WIND SHEAR IS WEAK WHICH DOES NOT SUPPORT ORGANIZED
SEVERE CONVECTION.
VERY WARM TEMPS CONTINUE WITH DEWPOINTS INCREASING A TAD AS COMPARED
TO YESTERDAY. HEAT INDICES ACROSS NYC METRO AND INTERIOR SHOULD
TOP OUT IN THE LOWER 90S ONCE AGAIN.
A MODERATE RISK FOR RIP CURRENTS EXISTS AT THE ATLANTIC OCEAN
BEACHES OF EASTERN LONG ISLAND TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
WEAK VORTS WILL CONTINUE TO ROTATE THROUGH THE REGION TONIGHT INTO
WEDNESDAY...AS A TROUGH DIGS INTO THE GREAT LAKES. AT THE
SURFACE...THE BACK DOOR FRONT WILL GRADUALLY PUSH NORTH TONIGHT INTO
WEDNESDAY. ON WEDNESDAY...A PRE-FRONTAL TROUGH WILL APPROACH THE
REGION IN THE AFTERNOON AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
NEAR HUDSON BAY.
MAIN FOCUS FOR ANY SHRA/TSRA TONIGHT SHOULD BE NORTH OF THE REGION
WITH LLJ FORCING AND THE NORTHWARD MOVING FRONTAL BOUNDARY OVERNIGHT.
OTHERWISE...WITH DIMINISHING INSTABILITY THIS EVENING...WOULD
EXPECTED ANY CONVECTION TO GRADUALLY WEAKEN. AN ISOLATED SHRA/TSRA
IS POSSIBLE OVERNIGHT WITH INCREASING LLJ...MARGINAL
INSTABILITY...AND WEAK VORT ACTIVITY...BUT MAINLY DRY. INCREASINGLY
MOIST SOUTHERLY FLOW WILL BRING A POTENTIAL FOR PATCHY FOG AND
STRATUS OVERNIGHT.
POTENTIAL INCREASES FOR MORE WIDESPREAD CONVECTION ACROSS WESTERN
ZONES...BETWEEN APPROACHING PRE-FRONTAL TROUGH AND SEABREEZE
BOUNDARY...WEDNESDAY AFTERNOON WITH STRENGTHENING WIND FIELDS AND
APPROACHING SHORTWAVE. SEVERE POTENTIAL WILL BE PREDICATED BY
AMOUNT OF SUNSHINE...BUT WITH AN INCREASINGLY MOIST AIRMASS A
MODERATELY UNSTABLE AIRMASS IS QUITE POSSIBLE IN THE ABOVE
MENTIONED AREA. THE OTHER THREAT WILL BE FOR HEAVY RAIN AND
POTENTIAL FLASH FLOODING WITH TRAINING CELLS ALONG S/N ORIENTED
BOUNDARIES AS PWATS INCREASE TO AROUND 2" AND WARM CLOUD LAYER
INCREASES.
VERY WARM AND INCREASINGLY HUMID CONDITIONS ON WED...WITH TEMPS IN
THE MID TO UPPER 80S NYC/NJ METRO AND INTERIOR...WITH LOWER TO MID
80S ALONG THE COAST IN SOUTHERLY SYNOPTIC FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
UNSETTLED WEATHER ON TAP FOR THE MIDDLE TO THE END OF THE WEEK AS
LOW PRES TRACKING ACROSS EASTERN CANADA DRAGS A COLD THROUGH THE
REGION ON THURSDAY. THE FIRST ROUND OF SHOWERS AND POSSIBLE
THUNDERSTORMS WILL TAPER OFF IN THE FIRST HALF OF WEDNESDAY
NIGHT....AND THEN ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WILL
DEVELOP ON THURSDAY AS WEAK LOW PRES DEVELOPS ALONG THE FRONT AND
SLIDES THROUGH THE REGION. WITH PWATS AROUND 2"...CAN EXPECT HEAVY
RAIN. SCATTERED TO NUMEROUS SHOWERS/TSTMS WILL IMPACT THE REGION
THROUGHOUT THE DAY...TAPERING OFF LATE.
BASED ON THE MODEST SW FLOW AND BUILDING SEAS...DANGEROUS RIPS
APPEAR LIKELY WED AND THU AT THE OCEAN.
COLD FRONT WILL BE THROUGH THE REGION THURSDAY NIGHT AND BECOMES
NEARLY STATIONARY EAST OF THE AREA. H5 TROUGH/SHORTWAVE MOVES RIGHT
OVER THE AREA ON FRIDAY AND THEN STALLS OUT OVER THE AREA. EVEN
THOUGH HIGH PRES BUILDS IN AT THE SFC...WILL HAVE TO KEEP AT LEAST
CHANCE POPS IN THE FORECAST FOR THE WEEKEND DUE TO THIS UPPER LEVEL
SYSTEM OVER THE AREA.
RETURN FLOW SETS UP BRINGING AN INCREASE IN THE HEAT AND HUMIDITY
AGAIN ON MON.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN OVER THE LOCAL AREA THROUGH
TODAY.
CONDITIONS WILL REMAIN PRIMARILY VFR TODAY. ONE EXCEPTION IS AT KGON
WHERE A WEAK COLD FRONT HAS PUSHED SOUTH AND BROUGHT IFR CIGS. THESE
CIGS HAVE BEGUN TO LIFT BUT MVFR/IFR AT TIMES IS STILL ANTICIPATED
THROUGH THE AFTERNOON.
WINDS WILL BE LIGHT AND MAY VARY TO E/ENE DIRECTION AT
KGON/KLGA THROUGH EARLY AFTERNOON. OTHERWISE...LIGHT SW WINDS
INCREASE TO 10 AND 15 KT AFTER 18Z. EARLY AFTERNOON SEA BREEZES
ARE EXPECTED.
SHOWERS AND TSTORMS ARE POSSIBLE TODAY...BUT CONFIDENCE TOO LOW IN
TIMING AND PLACEMENT TO INCLUDE IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE COULD BE OFF BY +/-
AN HOUR. BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER 18Z.
KLGA FCSTER COMMENTS: VRB WINDS THROUGH EARLY AFTN ALONG
STALLED BOUNDARY. TIMING OF WIND SHIFT/SEA BREEZE COULD BE OFF BY
+/- AN HOUR OR TWO EARLY THIS AFTN. BEST CHC FOR
SHOWERS/TSTMS WILL BE AFTER 17Z.
KTEB FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
KHPN FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
KISP FCSTER COMMENTS: TIMING OF SEA BREEZE COULD BE OFF BY +/- AN
HOUR.
.OUTLOOK FOR 15Z WEDNESDAY THROUGH SAT...
.WED-FRI...MVFR FOG/CIGS POSSIBLE DAILY 06Z-14Z. SCT TSTMS POSSIBLE
DAILY MAINLY 18Z-04Z WITH MVFR CIGS AND IFR VSBY IN HVY RAIN AND
GUSTY WINDS. OTHERWISE...MAINLY VFR.
.SAT...MAINLY VFR. MVFR POSSIBLE IN SHOWERS.
&&
.MARINE...
SUB SCA CONDS THROUGH TONIGHT WITH GENERAL SW WINDS EXPECTED.
WINDS ARE EXPECTED TO GRADUALLY INCREASE ON WEDNESDAY AHEAD OF AN
APPROACHING PRE-FRONTAL TROUGH. THERE IS POTENTIAL FOR MARGINAL
SCA WINDS ACROSS WESTERN OCEAN WATERS INTO ENTRANCE OF NYC HARBOR
LATE WED WITH COASTAL JET.
SOUTHERLY FLOW INCREASES ON WEDNESDAY AHEAD OF A SLOWLY MOVING COLD
FRONT. THIS WILL BUILD SEAS ON THE OCEAN TO SCA LEVELS BY WEDNESDAY
NIGHT...AND SCA CONDITIONS WILL CONTINUE THROUGH THURSDAY. OUTSIDE
OF THE S SHORE BAYS...WHERE WINDS MAY REACH SCA LEVELS...THE
REMAINING WATERS SHOULD REMAIN BELOW SCA LEVELS. HIGH PRES THEN
BUILDS NORTH OF THE WATERS FRIDAY THROUGH THE WEEKEND. CONDITIONS
ARE THEREFORE EXPECTED TO REMAIN BELOW SCA LEVELS.
&&
.HYDROLOGY...
SCATTERED SHOWERS/THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN
THIS AFTERNOON. AN ISOLATED FLASH FLOOD THREAT EXISTS WITH ANY
TRAINING CONVECTION...MAINLY ALONG THE WESTERN SEABREEZE BOUNDARY
AND/OR BACKDOOR COLD FRONT.
THE FLASH FLOOD THREAT SHOULD INCREASE A BIT ON WEDNESDAY
AFTERNOON ACROSS WESTERN PORTIONS OF THE AREA...AS HEAVY RAIN
ENVIRONMENT BECOMES INCREASINGLY FAVORABLE AND CONVECTIVE COVERAGE
IS EXPECTED TO INCREASE BETWEEN AN APPROACHING PRE-FRONTAL TROUGH
AND SEABREEZE BOUNDARY. THE THREAT FOR FLASH FLOODING WILL EXIST
IN THE PATH OF ANY TRAINING THUNDERSTORMS.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL
WEDNESDAY THROUGH THURSDAY NIGHT ACROSS THE HSA. ALTHOUGH WIDESPREAD
FLOODING IS NOT EXPECTED AT THIS TIME...FLASH FLOODING IS POSSIBLE
WITH ANY TRAINING CONVECTION.
RAINFALL IN EXCESS OF 2 INCHES IS POSSIBLE IN AN AREA IF
THUNDERSTORMS TRAIN OVER THAT AREA FOR AN HOUR.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPS/NV
NEAR TERM...NV/DW
SHORT TERM...NV
LONG TERM...MPS
AVIATION...BC
MARINE...MPS/NV
HYDROLOGY...MPS/NV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1059 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK FRONT ACROSS SOUTHERN CONNECTICUT WILL GRADUALLY RETURN
NORTH THIS AFTERNOON. A WEAK TROUGH APPROACHES WEDNESDAY
AFTERNOON...WITH A SLOWLY MOVING FRONTAL SYSTEM AFFECTING THE
REGION THROUGH THE END OF THE WEEK. A COLD FRONT SLOWLY MOVES
THROUGH THE REGION WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND
THEN STALLS OFFSHORE. HIGH PRESSURE THEN TRIES TO BUILD INTO THE
REGION FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON LATEST RADAR IMAGERY AND OBS...A WEAK...DIFFUSE COLD FRONT
APPEARS TO HAVE PUSHED ACROSS SRN CT...WITH LOCAL SEA- AND SOUND-
BREEZES MAKING IT DIFFICULT TO PINPOINT THE EXACT LOCATION.
LATEST HRRR MODEL TAKES BOUNDARY SLOWLY NORTH THIS AFTERNOON WITH
CONVECTION BEING INITIATED ACROSS INTERIOR CT. ADDITIONAL SCT
CONVECTION WILL LIKELY FIRE UP WITH AN APPROACHING SHORT WAVE TROF
TO THE NORTH AND WEST OF NYC...BEFORE DISSIPATING NEAR THE COAST
EARLY THIS EVE. SEABREEZE BOUNDARY IS ALSO ANOTHER POTENTIAL
TRIGGER FOR CONVECTION. DUE TO WEAK STEERING WINDS FROM THE WEST
AT 10 KT OR LESS...ANY CONVECTION WILL BE CAPABLE OF BRIEF HEAVY
DOWNPOURS. WIND SHEAR IS WEAK WHICH DOES NOT SUPPORT ORGANIZED
SEVERE CONVECTION.
VERY WARM TEMPS CONTINUE WITH DEWPOINTS INCREASING A TAD AS COMPARED
TO YESTERDAY. HEAT INDICES ACROSS NYC METRO AND INTERIOR SHOULD
TOP OUT IN THE LOWER 90S ONCE AGAIN.
A MODERATE RISK FOR RIP CURRENTS EXISTS AT THE ATLANTIC OCEAN
BEACHES OF EASTERN LONG ISLAND TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
WEAK VORTS WILL CONTINUE TO ROTATE THROUGH THE REGION TONIGHT INTO
WEDNESDAY...AS A TROUGH DIGS INTO THE GREAT LAKES. AT THE
SURFACE...THE BACK DOOR FRONT WILL GRADUALLY PUSH NORTH TONIGHT INTO
WEDNESDAY. ON WEDNESDAY...A PRE-FRONTAL TROUGH WILL APPROACH THE
REGION IN THE AFTERNOON AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
NEAR HUDSON BAY.
MAIN FOCUS FOR ANY SHRA/TSRA TONIGHT SHOULD BE NORTH OF THE REGION
WITH LLJ FORCING AND THE NORTHWARD MOVING FRONTAL BOUNDARY OVERNIGHT.
OTHERWISE...WITH DIMINISHING INSTABILITY THIS EVENING...WOULD
EXPECTED ANY CONVECTION TO GRADUALLY WEAKEN. AN ISOLATED SHRA/TSRA
IS POSSIBLE OVERNIGHT WITH INCREASING LLJ...MARGINAL
INSTABILITY...AND WEAK VORT ACTIVITY...BUT MAINLY DRY. INCREASINGLY
MOIST SOUTHERLY FLOW WILL BRIG POTENTIAL FOR PATCHY FOG AND STRATUS
OVERNIGHT.
POTENTIAL INCREASES FOR MORE WIDESPREAD CONVECTION ACROSS WESTERN
ZONES...BETWEEN APPROACHING PRE-FRONTAL TROUGH AND SEABREEZE
BOUNDARY...WEDNESDAY AFTERNOON WITH STRENGTHENING WIND FIELDS AND
APPROACHING SHORTWAVE. SEVERE POTENTIAL WILL BE PREDICATED BY
AMOUNT OF SUNSHINE...BUT WITH AN INCREASINGLY MOIST AIRMASS A
MODERATELY UNSTABLE AIRMASS IS QUITE POSSIBLE IN THE ABOVE
MENTIONED AREA. THE OTHER THREAT WILL BE FOR HEAVY RAIN AND
POTENTIAL FLASH FLOODING WITH TRAINING CELLS ALONG S/N ORIENTED
BOUNDARIES AS PWATS INCREASE TO AROUND 2" AND WARM CLOUD LAYER
INCREASES.
VERY WARM AND INCREASINGLY HUMID CONDITIONS ON WED...WITH TEMPS IN
THE MID TO UPPER 80S NYC/NJ METRO AND INTERIOR...WITH LOWER TO MID
80S ALONG THE COAST IN SOUTHERLY SYNOPTIC FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
UNSETTLED WEATHER ON TAP FOR THE MIDDLE TO THE END OF THE WEEK AS
LOW PRES TRACKING ACROSS EASTERN CANADA DRAGS A COLD THROUGH THE
REGION ON THURSDAY. THE FIRST ROUND OF SHOWERS AND POSSIBLE
THUNDERSTORMS WILL TAPER OFF IN THE FIRST HALF OF WEDNESDAY
NIGHT....AND THEN ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WILL
DEVELOP ON THURSDAY AS WEAK LOW PRES DEVELOPS ALONG THE FRONT AND
SLIDES THROUGH THE REGION. WITH PWATS AROUND 2"...CAN EXPECT HEAVY
RAIN. SCATTERED TO NUMEROUS SHOWERS/TSTMS WILL IMPACT THE REGION
THROUGHOUT THE DAY...TAPERING OFF LATE.
BASED ON THE MODEST SW FLOW AND BUILDING SEAS...DANGEROUS RIPS
APPEAR LIKELY WED AND THU AT THE OCEAN.
COLD FRONT WILL BE THROUGH THE REGION THURSDAY NIGHT AND BECOMES
NEARLY STATIONARY EAST OF THE AREA. H5 TROUGH/SHORTWAVE MOVES RIGHT
OVER THE AREA ON FRIDAY AND THEN STALLS OUT OVER THE AREA. EVEN
THOUGH HIGH PRES BUILDS IN AT THE SFC...WILL HAVE TO KEEP AT LEAST
CHANCE POPS IN THE FORECAST FOR THE WEEKEND DUE TO THIS UPPER LEVEL
SYSTEM OVER THE AREA.
RETURN FLOW SETS UP BRINGING AN INCREASE IN THE HEAT AND HUMIDITY
AGAIN ON MON.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
A TROUGH OF LOW PRESSURE WILL REMAIN OVER THE LOCAL AREA THROUGH
TODAY.
CONDITIONS WILL REMAIN PRIMARILY VFR TODAY. ONE EXCEPTION IS AT KGON
WHERE A WEAK COLD FRONT HAS PUSHED SOUTH AND BROUGHT IFR CIGS. THESE
CIGS HAVE BEGUN TO LIFT BUT MVFR/IFR AT TIMES IS STILL ANTICIPATED
THROUGH THE AFTERNOON.
WINDS WILL BE LIGHT AND MAY VARY TO E/ENE DIRECTION AT
KGON/KBDR/KLGA/KISP THROUGH EARLY AFTERNOON. OTHERWISE...LIGHT SW
WINDS INCREASE TO 10 AND 15 KT AFTER 18Z. EARLY AFTERNOON SEA
BREEZES ARE EXPECTED.
SHOWERS AND TSTORMS ARE POSSIBLE TODAY...BUT CONFIDENCE TOO LOW IN
TIMING AND PLACEMENT TO INCLUDE IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE COULD BE OFF BY +/-
AN HOUR. BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER 18Z.
KLGA FCSTER COMMENTS: VRB WINDS THROUGH EARLY AFTN ALONG
STALLED BOUNDARY. TIMING OF WIND SHIFT/SEA BREEZE COULD BE OFF BY
+/- AN HOUR OR TWO EARLY THIS AFTN. BEST CHC FOR
SHOWERS/TSTMS WILL BE AFTER 17Z.
KTEB FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
KHPN FCSTER COMMENTS: BEST CHANCE FOR SHOWERS/TSTORMS WILL BE AFTER
18Z.
KISP FCSTER COMMENTS: TIMING OF SEA BREEZE COULD BE OFF BY +/- AN
HOUR.
.OUTLOOK FOR 15Z WEDNESDAY THROUGH SAT...
.WED-FRI...MVFR FOG/CIGS POSSIBLE DAILY 06Z-14Z. SCT TSTMS POSSIBLE
DAILY MAINLY 18Z-04Z WITH MVFR CIGS AND IFR VSBY IN HVY RAIN AND
GUSTY WINDS. OTHERWISE...MAINLY VFR.
.SAT...MAINLY VFR. MVFR POSSIBLE IN SHOWERS.
&&
.MARINE...
SUB SCA CONDS THROUGH TONIGHT WITH GENERAL SW WINDS EXPECTED.
WINDS ARE EXPECTED TO GRADUALLY INCREASE ON WEDNESDAY AHEAD OF AN
APPROACHING PRE-FRONTAL TROUGH. THERE IS POTENTIAL FOR MARGINAL
SCA WINDS ACROSS WESTERN OCEAN WATERS INTO ENTRANCE OF NYC HARBOR
LATE WED WITH COASTAL JET.
SOUTHERLY FLOW INCREASES ON WEDNESDAY AHEAD OF A SLOWLY MOVING COLD
FRONT. THIS WILL BUILD SEAS ON THE OCEAN TO SCA LEVELS BY WEDNESDAY
NIGHT...AND SCA CONDITIONS WILL CONTINUE THROUGH THURSDAY. OUTSIDE
OF THE S SHORE BAYS...WHERE WINDS MAY REACH SCA LEVELS...THE
REMAINING WATERS SHOULD REMAIN BELOW SCA LEVELS. HIGH PRES THEN
BUILDS NORTH OF THE WATERS FRIDAY THROUGH THE WEEKEND. CONDITIONS
ARE THEREFORE EXPECTED TO REMAIN BELOW SCA LEVELS.
&&
.HYDROLOGY...
SCATTERED SHOWERS/THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN
THIS AFTERNOON. AN ISOLATED FLASH FLOOD THREAT EXISTS WITH ANY
TRAINING CONVECTION...MAINLY ALONG THE WESTERN SEABREEZE BOUNDARY
AND/OR BACKDOOR COLD FRONT.
THE FLASH FLOOD THREAT SHOULD INCREASE A BIT ON WEDNESDAY
AFTERNOON ACROSS WESTERN PORTIONS OF THE AREA...AS HEAVY RAIN
ENVIRONMENT BECOMES INCREASINGLY FAVORABLE AND CONVECTIVE COVERAGE
IS EXPECTED TO INCREASE BETWEEN AN APPROACHING PRE-FRONTAL TROUGH
AND SEABREEZE BOUNDARY. THE THREAT FOR FLASH FLOODING WILL EXIST
IN THE PATH OF ANY TRAINING THUNDERSTORMS.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL
WEDNESDAY THROUGH THURSDAY NIGHT ACROSS THE HSA. ALTHOUGH WIDESPREAD
FLOODING IS NOT EXPECTED AT THIS TIME...FLASH FLOODING IS POSSIBLE
WITH ANY TRAINING CONVECTION.
RAINFALL IN EXCESS OF 2 INCHES IS POSSIBLE IN AN AREA IF
THUNDERSTORMS TRAIN OVER THAT AREA FOR AN HOUR.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPS/NV
NEAR TERM...NV/DW
SHORT TERM...NV
LONG TERM...MPS
AVIATION...BC
MARINE...MPS/NV
HYDROLOGY...MPS/NV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1125 AM EDT TUE JUL 9 2013
.UPDATE...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UNAMPLIFIED UPPER LEVEL
PATTERN WITH THE MAIN NORTHERN STREAM FLOW ALIGNED ZONALLY OVER THE
U.S/CANADIAN BORDER. TO THE SOUTH OF THE NORTHERN STREAM WE FIND A
BROAD EXPANSE OF UPPER LEVEL RIDGING IN PLACE ACROSS MUCH OF THE
SOUTHERN TIER OF THE CONUS. ONE OTHER FEATURE OF NOTE IS A TUTT
FEATURE/UPPER LOW SLOWLY MIGRATING WESTWARD FROM THE BAHAMAS TOWARD
THE SOUTHERN FL PENINSULA. THIS TUTT FEATURE MAY BRING SOME ENHANCED
RAIN CHANCES TO THE AREA ON WEDNESDAY...ESPECIALLY FOR THE SOUTHERN
HALF OF THE PENINSULA...BUT OVERALL WILL BE IN A WEAKENING PHASE IN
TERMS OF ITS NEGATIVE THERMAL ANOMALY...AND THIS SHOULD LIMIT THE
OVERALL POSITIVE INSTABILITY IMPACT THAT TUTT CELLS CAN HAVE TOWARD
DIURNAL CONVECTION THIS TIME OF YEAR.
AT THE SURFACE...HIGH PRESSURE IS ALIGNED FROM OFF THE GA/SC COAST
WESTWARD ALONG OR JUST NORTH OF THE I-10 CORRIDOR. WE FIND OUR
FORECAST AREA SITUATED BETWEEN THIS RIDGE AXIS AND A WEAK INVERTED
TROUGH ALONG THE FL SE COAST. THIS TROUGH IS REALLY JUST THE SURFACE
REFLECTION OF THE TUTT...AND IS PROGGED BY THE LATEST NAM/GFS AND
LOCAL HI-RES MODELS TO MIGRATE IN ADVANCE OF THE UPPER LEVEL FEATURE
ACROSS TO THE SOUTHWEST PENINSULA COAST BY THIS EVENING. THE ADDED
LOW LEVEL FOCUS ASSOCIATED WITH THIS WEAK TROUGH MAY HELP TO ENHANCE
THE DIURNAL THUNDERSTORM ACTIVITY FOR OUR SOUTHERN COASTAL ZONES
LATER THIS AFTERNOON.
REST OF TODAY...
ANOTHER COUPLE HOURS OF GENERALLY DRY CONDITIONS FOR OUR ZONES
BEFORE THE DIURNAL CONVECTION BEGINS TO FOCUS. SIMILAR TO PREVIOUS
DAYS...RAIN CHANCES...ESPECIALLY NEAR THE COAST WILL PEAK DURING THE
LATE AFTERNOON/EVENING HOURS. 12Z KTBW SOUNDING WAS A BIT ON THE DRY
SIDE...AND WOULD NOT BE AN UNFAVORABLE PROFILE TO SUPPORT A FEW
WET-MICROBURSTS WITH ANY STRONGER LATE DAY STORMS.
HOWEVER...NUMERICAL GUIDANCE DOES INDICATE THAT DRIEST OF THE
MID-LEVEL AIR WILL MODIFY SOMEWHAT BY THIS EVENING AND DECREASE THIS
THETA-E DIFFERENCE FROM THE SURFACE. THE BEST POSITIVE MOISTURE
ADVECTION WILL CERTAINLY BE DOWN TOWARD FT. MYERS. THE NET RESULT OF
THIS WOULD LIKELY TO FURTHER ENHANCE THE STORM COVERAGE SOUTH OF
TAMPA BAY...BUT LIMIT THE POTENTIAL WIND IMPACTS FROM ANY STRONGER
STORMS. FROM TAMPA BAY NORTHWARD...THE DRIER COLUMN SHOULD KEEP THE
ACTIVITY MORE SCATTERED...BUT ANY STRONGER STORMS WILL NEED TO BE
WATCHED CLOSELY FOR STRONG WIND GUST POTENTIAL.
LINGERING EVENING STORMS WILL SHIFT OFFSHORE AND WEAKEN DURING THE
MID/LATE EVENING HOURS. THE WEAK UPPER LEVEL SUPPORT FROM THE TUTT
IS LIKELY TO AID ANY TYPICAL NOCTURNAL LAND BREEZE CONVECTION OVER
THE WATER. HAVE INCREASED POPS AFTER MIDNIGHT AWAY FROM THE COAST
INTO THE CHANCE 30-40% RANGE. JUST SOMETHING TO KEEP IN MIND FOR
THOSE PLANNING TO BOAT EARLY IN THE MORNING.
&&
.AVIATION...
MAINLY VFR CONDITIONS BUT WITH A CHANCE OF TSRA IN THE AFTERNOON.
WILL HANDLE WITH VCNTY REMARK FOR NOW. EASTERLY WINDS SHIFT TO
ONSHORE IN THE AFTERNOON ALONG THE COAST.
&&
.MARINE...
A FAIRLY WEAK PRESSURE PATTERN IS EXPECTED ACROSS THE WATERS THROUGH
THE FORECAST PERIOD...WITH THE ONLY POTENTIAL CAVEAT BEING THE TRACK
OF TROPICAL STORM CHANTAL OR IT/S REMNANT LOW OVER THE WEEKEND AND
INTO EARLY NEXT WEEK. THE LATEST FORECAST FROM THE NATIONAL
HURRICANE CENTER CONTINUES TO SHOW THE SYSTEM MOVING NORTHWARD WELL
OFF THE EAST FLORIDA COAST...WHICH WOULD RESULT IN LITTLE IF ANY
IMPACT ON THE LOCAL MARINE AREA. AS A RESULT...WINDS AND SEAS ARE
EXPECTED TO REMAIN BELOW HEADLINE THRESHOLDS THROUGH THE FORECAST
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 75 90 76 / 40 30 40 30
FMY 91 72 91 74 / 50 20 50 30
GIF 91 72 91 74 / 30 10 30 20
SRQ 91 73 89 74 / 40 30 40 20
BKV 93 70 91 71 / 40 20 40 30
SPG 92 77 90 77 / 40 30 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
926 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LIGHT SOUTHWEST WINDS EXPECTED TO CONTINUE WITH NORTHEAST WINDS
OFF THE LAKE EXPECTED TO STAY EAST OF THE TERMINALS THIS
MORNING.
* SHRA/TSRA CHANCES INCREASING FROM LATE MORNING THROUGH THE
AFTERNOON.
MDB
//DISCUSSION...UPDATED 14Z...
MADE SOME ADJUSTMENTS TO THE WINDS THIS MORNING TO BRING THEM
SOUTHWESTERLY AT ORD/MDW/GYY. A LIGHT NORTHEAST WIND IS OCCURRING
RIGHT ALONG THE LAKESHORE BUT HAS NOT MADE MUCH IF ANY PROGRESS
INLAND. WITH INCREASING CLOUD COVER SLOWING THE HEATING OVER LAND
COMPARED TO OVER THE LAKE...PRESSURE FALLS STARTING TO SPREAD IN
AND A SLOWLY INCREASING PRESSURE GRADIENT OPTED TO KEEP WINDS
LIGHT FROM THE SOUTHWEST. NEXT CONCERN IS SHOWERS AND
THUNDERSTORMS STRETCHING FROM NEAR VYS TO SFY TO PVB. THIS
ACTIVITY CONTINUES TO MOVE EASTWARD WITH COVERAGE INCREASING
SOMEWHAT. OTHERWISE SCATTERED VERY LIGHT SHOWERS DO RUN ALONG A
LINE FROM GYY WEST TO VYS. RFD WILL LIKELY HAVE PERIODIC TSRA
ARRIVE IN THE NEXT HOUR OR SO BUT COVERAGE TO THE EAST IS SOMEWHAT
IN QUESTION. IT APPEARS THAT THE INITIAL ACTIVITY WILL STAY JUST
SOUTH OF ORD/MDW AND GRAZE GYY BUT ACTIVITY MAY BUILD AND INCREASE
IN COVERAGE AS THE ENTIRE COMPLEX WORKS EAST. BARRING MUCH NEW
DEVELOPMENT EASTWARD THE CURRENT ACTIVITY WOULD LIKELY WORK INTO
THE CHI AREA TOWARD 17Z. MAY NEED TO SPEED THIS UP IN THE TAFS AS
THE TRENDS BECOME MORE CLEAR.
MDB
FROM 12Z...
RELATIVELY QUIET ACROSS THE TERMINALS THIS MORNING WHILE SOME
FOG/HAZE REMAINS OVERHEAD...BUT WITH THE MORE DENSE FOG REMAINING
AWAY FROM THE TERMINALS AT THIS TIME. ANY FOG THIS MORNING SHOULD
QUICKLY DISSIPATE OVER THE NEXT HOUR WITH ANY THREAT OF LOWER
VIS/CEILINGS COMING SOUTH DOWN THE LAKE REMAINING LOW AT THIS
TIME. ALTHOUGH THIS AREA IS STILL SLOWLY MOVING SOUTH DOWN THE
LAKE...VEERING WINDS AND SHOULD HELP LIMIT THIS SOUTHWARD MOMENTUM
KEEPING THIS FOG NORTH OF THE TERMINALS. THEN SHIFT GEARS TO
REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING...AS PRECIP
DEVELOPS OUT AHEAD OF AN APPROACHING MID LEVEL DISTURBANCE. AS
THIS DISTURBANCE DRAWS NEAR...EXPECT CURRENT THUNDERSTORMS OVER
IOWA AS WELL AS OTHER DEVELOPMENT TO MOVE ACROSS THROUGH NORTHERN
ILLINOIS/NORTHWEST INDIANA BY MID DAY WITH SOME UPWARD GROWTH IN
COVERAGE AND INTENSITY EXPECTED INTO THE EARLY AFTERNOON. DO
EXPECT A BRIEF LULL IN THE ACTIVITY AFTER THIS INITIAL PRECIP
MOVES THROUGH...BUT WITH DEVELOPMENT STILL POSSIBLE GOING INTO THE
EARLY EVENING. STILL MONITORING THE POTENTIAL FOR A MORE
WIDESPREAD AREA OF THUNDERSTORMS TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT. ALTHOUGH IT STILL SEEMS
FAVORABLE FOR THIS TO MOVE ACROSS THE TERMINALS...WILL NEED TO
MONITOR LATER TRENDS AFTER THIS INITIAL PRECIP THIS AFTERNOON
MOVES THROUGH.
WINDS REMAIN LIGHT/VARIABLE THIS MORNING BUT ANTICIPATE A TREND
TOWARDS AN EAST NORTHEAST WIND OVER THE NEXT SEVERAL HOURS. WINDS
ALONG THE LAKE ARE ALREADY THIS EASTERLY COMPONENT AND WITH THE
SUN RISING COINCIDING WITH A WEAK GRADIENT...FEEL THAT IT WONT
TAKE MUCH FOR THIS NORTHEAST WIND TO DEVELOP OVER ORD/MDW/GYY THIS
MORNING. THEN EXPECT A SLOW TREND TOWARDS THE SOUTHEAST AND
EVENTUALLY SOUTH THIS AFTERNOON/EVENING...BEFORE WINDS CONTINUE TO
VEER TO THE WEST OVERNIGHT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN LIGHT SOUTHWEST WINDS PREVAILING
THROUGH THE MORNING.
* MEDIUM-HIGH CONFIDENCE IN SHRA/TSRA AFFECTING THE
TERMINALS...MEDIUM CONFIDENCE IN TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
705 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LINGERING FOG TO QUICKLY DISSIPATE THIS MORNING.
* AN INCREASE IN SHOWERS/TS EXPECTED BY MID DAY...AND THEN
EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE
AFTERNOON.
* MORE WIDESPREAD SHOWERS/TS POSSIBLY TO MOVE ACROSS THE TERMINALS
ONCE AGAIN LATER THIS EVENING AND OVERNIGHT.
* VARIABLE WINDS THIS MORNING BECOMING LIGHT OUT OF THE EAST
NORTHEAST BY MID MORNING...AND THEN SLOWLY BECOMING MORE
SOUTHEAST THIS AFTERNOON AND EVENTUALLY SOUTHERLY THIS EVENING.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
RELATIVELY QUIET ACROSS THE TERMINALS THIS MORNING WHILE SOME
FOG/HAZE REMAINS OVERHEAD...BUT WITH THE MORE DENSE FOG REMAINING
AWAY FROM THE TERMINALS AT THIS TIME. ANY FOG THIS MORNING SHOULD
QUICKLY DISSIPATE OVER THE NEXT HOUR WITH ANY THREAT OF LOWER
VIS/CEILINGS COMING SOUTH DOWN THE LAKE REMAINING LOW AT THIS
TIME. ALTHOUGH THIS AREA IS STILL SLOWLY MOVING SOUTH DOWN THE
LAKE...VEERING WINDS AND SHOULD HELP LIMIT THIS SOUTHWARD MOMENTUM
KEEPING THIS FOG NORTH OF THE TERMINALS. THEN SHIFT GEARS TO
REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING...AS PRECIP
DEVELOPS OUT AHEAD OF AN APPROACHING MID LEVEL DISTURBANCE. AS
THIS DISTURBANCE DRAWS NEAR...EXPECT CURRENT THUNDERSTORMS OVER
IOWA AS WELL AS OTHER DEVELOPMENT TO MOVE ACROSS THROUGH NORTHERN
ILLINOIS/NORTHWEST INDIANA BY MID DAY WITH SOME UPWARD GROWTH IN
COVERAGE AND INTENSITY EXPECTED INTO THE EARLY AFTERNOON. DO
EXPECT A BRIEF LULL IN THE ACTIVITY AFTER THIS INITIAL PRECIP
MOVES THROUGH...BUT WITH DEVELOPMENT STILL POSSIBLE GOING INTO THE
EARLY EVENING. STILL MONITORING THE POTENTIAL FOR A MORE
WIDESPREAD AREA OF THUNDERSTORMS TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT. ALTHOUGH IT STILL SEEMS
FAVORABLE FOR THIS TO MOVE ACROSS THE TERMINALS...WILL NEED TO
MONITOR LATER TRENDS AFTER THIS INITIAL PRECIP THIS AFTERNOON
MOVES THROUGH.
WINDS REMAIN LIGHT/VARIABLE THIS MORNING BUT ANTICIPATE A TREND
TOWARDS AN EAST NORTHEAST WIND OVER THE NEXT SEVERAL HOURS. WINDS
ALONG THE LAKE ARE ALREADY THIS EASTERLY COMPONENT AND WITH THE
SUN RISING COINCIDING WITH A WEAK GRADIENT...FEEL THAT IT WONT
TAKE MUCH FOR THIS NORTHEAST WIND TO DEVELOP OVER ORD/MDW/GYY THIS
MORNING. THEN EXPECT A SLOW TREND TOWARDS THE SOUTHEAST AND
EVENTUALLY SOUTH THIS AFTERNOON/EVENING...BEFORE WINDS CONTINUE TO
VEER TO THE WEST OVERNIGHT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE WITH FOG/VIS THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWERS/TS MID DAY THROUGH THE AFTERNOON.
* MEDIUM CONFIDENCE WITH SHOWERS/TS LATER THIS EVENING/OVERNIGHT.
* MEDIUM CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1057 AM CDT TUE JUL 9 2013
.UPDATE...
ISSUED AT 1050 AM CDT TUE JUL 9 2013
2 MAJOR UPDATES HAVE BEEN SEND THIS MORNING...REFLECTING CHANGES
BASED ON RADAR TRENDS...AND NOW BOTH CONVECTIVE TRENDS COMBINED
WITH MORNING UA ANALYSIS AND EARLY SIGNALS IN MODEL GUIDANCE.
THE PARADE OF TWO MCV FEATURES IS NOTED ON RADAR AND
SATELLITE...AND THUS THE NEXT 4 HOURS WILL CERTAINLY BE OUR MAIN
SHOW WITH RESPECT TO RAINFALL POTENTIAL. AMOUNTS THUS FAR ARE
SCATTERED AND SIGNIFICANT ...OVER 1 INCH......BUT MOST OF THE AREA
RECEIVING ONLY LIGHT AMOUNTS OR NEARLY DRY...ESPECIALLY SOUTH.
SURFACE CAPE WILL BE LIMITED TO ONLY THE SOUTH TODAY AND EARLY
THIS EVENING...THUS OUR BEST POTENTIAL FOR MORE SIGNIFICANT STORMS
IS THERE. ELSEWHERE I HAVE CONTINUED TO LOWER EVENING POPS...AS
WELL AS AFTERNOON POPS IN THE WEST. TONIGHT COULD VERY WELL BE DRY
OVER OUR WESTERN 1/3 OF THE CWA...AND POSSIBLY WESTERN 2/3 IF THE
VEERED MOISTURE PLUME CANNOT RECOVER FROM THE MCV PASSAGES. THIS
GREATLY WILL LOWER THE SEVERE THREAT...AND I WILL AWAIT THE SPC
UPDATE BEFORE UPDATING THE HWO TO REFLECT THAT POSSIBLE LOWERED
MAGNITUDE OF THE THREAT.
TEMPERATURES HAVE BEEN LOWERED TO MAINLY MID 80S HIGHS...WHICH
SHOULD EASILY OCCUR ONCE CONVECTION STOPS FIRING...BUT SAFE TO
SAY...OUR NEAR ADVISORY LEVEL HEAT WILL NOT VERIFY TODAY. IT WILL
MOST CERTAINLY BE QUITE MUGGY OUT THERE.
ERVIN
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 9 2013
06Z MSAS SFC ANALYSIS SUPPORTIVE OF WEAK LOW OVER CENTRAL SD WITH
STATIONARY FRONT EXTENDING SEWD FROM THE LOW AND BISECTING
EASTERN IA AND NORTHWEST IL. MOISTURE IS POOLING ALONG THE FRONT
WITH DEWPTS OF 70-75F. 00Z KDVN RAOB SHOWS DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES OF NEARLY 2 INCHES... WHICH IS AROUND 160
PERCENT OF NORMAL AND NEARLY 2 STANDARD DEVIATIONS ABOVE THE MEAN.
CONVECTIVELY ENHANCED VORT MAX IS TRACKING THROUGH EASTERN NE ATTM
WITH RADARS SHOWING SHOWERS AND STORMS AHEAD OF THIS FEATURE INTO
WESTERN IA. ADDITIONAL COMPLEX OF STORMS WAS OVER THE DAKOTAS
AHEAD OF COLD FRONT AND SHORTWAVE MOVING EAST THROUGH FAR SOUTHERN
ALBERTA PROVINCE AND NORTHERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 9 2013
SUGGESTIONS OF 2 MAIN ROUNDS OF STORMS THROUGH THE PERIOD. AS
CONVECTIVELY ENHANCED VORT MAX MOVES EAST FROM NE ANTICIPATE
SHOWERS AND STORMS TRACKING AHEAD OF THIS FEATURE TO MOVE ACROSS
THE REGION BY MID AM THROUGH EARLY AFTN. PRIOR TO THE ARRIVAL
OF THESE STORMS COULD SEE ADDITIONAL DEVELOPMENT PRIOR TO MID AM
OVER THE AREA WITH WARM ADVECTION WING. POTENTIAL FOR SOME
STRENGTHENING OF MID LEVEL WINDS AND INTENSIFICATION OF STORMS
BY LATE AM AND AFTN FOR RISK OF FEW STRONG TO ISOLD SEVERE STORMS
WITH MOST RECENT RUNS OF HRRR 2-5KM UPDRAFT HELICITY AND 3 KM
VELOCITY CONTINUING TO SUGGEST THIS RISK NEAR AND ESPECIALLY NORTH
OF I-80. MAY SEE BREAK IN ACTION OR RELATIVE LULL IN ACTIVITY
BY MID-LATE AFTN WITH FOCUS SHIFTING BACK NORTHWEST FOR DEVELOPMENT
AHEAD OF COLD FRONT. LIKELY TO SEE ANOTHER ROUND OF STORMS MOVE
THROUGH THIS EVENING INTO OVERNIGHT AHEAD OF COLD FRONT.
STRENGTHENING 40-60 KT MID LEVEL SPEED MAX SPREADING BEHIND FRONT
COUPLED WITH VERY UNSTABLE ENVIRONMENT WILL SUPPORT RISK OF SEVERE
STORMS WITH POTENTIAL FOR UPSCALE GROWTH TO LINEAR MCS WITH MAINLY
DAMAGING WIND THREAT. HEAVY RAIN WILL BE A CONCERN AS WELL GIVEN
THE DEEP ALMOST TROPICAL MOISTURE IN PLACE. STORMS SHOULD BE MOVING
ALONG MORE THAN WE/VE SEEN OF LATE BUT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH RATES LIKELY 1-2"/HR. THUS... CANT RULE OUT SOME
LOCALIZED FLASH FLOODING AND WILL HAVE TO BE ESPECIALLY WATCHFULL
OVER PORTIONS OF DELAWARE AND DUBUQUE COUNTIES WHICH HAVE SEEN 2-5
INCHES PAST 24-36 HRS. EXPECT PCPN SHOULD BE DIMINISHING FROM NW
TO SE OVRNGT WITH PASSAGE OF COLD FRONT.
HIGHS TDY TRICKY WITH CLOUDS AND PCPN BUT OVERALL SHOULD RANGE FROM
MID 80S TO THE LOWER 90S. SOME MIXING OUT OF DEWPTS MAY OCCUR BUT
AT LEAST UPPER 60S TO LOWER 70S EXPECTED ON DEWPTS... WHICH COMBINED
WITH TEMPS WILL MAKE FOR HEAT INDICES MAINLY IN THE MID TO UPPER 90S.
COOLER AND DRIER AIR LAGS BEHIND FRONT TNGT... THUS LOWS ONLY DROP
INTO THE UPPER 60S TO LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUL 9 2013
WEDNESDAY AND THURSDAY...AS L/W TROF CONTINUES TO DEEPEN AND
ESTABLISH ACRS THE GRT LKS...SEASONABLY STRONG LLVL HIGH PRESSURE
WILL LOOK TO DUMP DOWN THE NORTHERN PLAINS AND MO RVR VALLEY ON WED.
A FEW POST-FRONTAL SHOWERS AND STORMS MAY BE OCCURRING ACRS THE FAR
EASTERN/SOUTHERN CWA WED MORNING BUT BULK OF THE ACTIVITY SHOULD BE
GONE BY 15Z. VEERING AND INCREASING BOUNDARY LAYER FLOW AS WELL AS
INCOMING SUBSIDENCE SHOULD CLEAR THINGS OUT ON WED...BUT SOME LAG IN
CAA TO ALLOW TEMPS TO WARM INTO THE LOW TO MID 80S EVEN POST-
FRONTALLY. A RATHER BREEZY NORTHWEST TO NORTH WIND OF 15-20 MPH.
CLEAR SKIES AND WIND DROP OFF WED NIGHT TO ALLOW SOME AREA TEMPS TO
DROP OFF INTO THE 50S. LLVL HIGH PRESSURE CONTINUING TO MIGRATE
EASTWARD ACRS THE REGION TO MAKE FOR A CHAMBER OF COMMERCE DAY THU
WITH HIGHS IN THE UPPER 70S TO LOWER 80S...SUNSHINE AND LOWER
HUMIDITY. THU NIGHT SEASONABLY COOL AGAIN WITH LOWS IN THE 50S AND
LOW 60S.
FRIDAY THROUGH NEXT MONDAY...TRENDS OF THE LATEST RUN 00Z MEDIUM
RANGE SOLUTIONS AND ENSEMBLES SUGGEST SOME DIGGING TROFFINESS IN THE
PACIFIC NORTHWEST/WESTERN CANADA TO TRANSLATE INTO PUMPED UP UPPER
RIDGING ACRS THE MID CONUS FRI INTO SAT. THUS WHILE THERMAL DOME
INTENSIFIES ACRS THE GRT BSN INTO THE SOUTHWESTERN PLAINS...MCS
TRACK/RING OF FIRE PATTERN TO ESTABLISH IN NORMAL DEEP SUMMER
LOCATION OF NORTHWESTERN HIGH PLAINS...UPPER MS RVR VALLEY...SOUTHERN
CANADA AND INTO THE GRT LKS. LATEST INDICATIONS SUGGEST A LESSENING
CHANCE FOR SOME OF THIS MCS ACTIVITY TO SPILL DOWN ACRS THE
NORTHERN CWA EITHER FRI NIGHT OR SAT NIGHT WHILE TEMPERATURES START
TO REBOUND BACK TO NORMAL OR EVEN WARMER. BY SUNDAY...WESTERLIES
FIRMLY ESTABLISH ACRS THE U.S.-CANADIAN BORDER REGION WITH UPPER
RIDGING DOMINATING ACRS THE SOUTHERN 2/3S OF THE CONUS. LONGER
RANGE THERMAL PROFILES SUGGEST ENOUGH AIRMASS MODIFICATION TO DRIVE
SUNDAY HIGHS UP INTO AT LEAST THE LOWER 90S ALONG WITH INCREASING
SFC DPTS/HUMIDITY. PASSING WAVE IN THIS PROGRESSIVE FLOW MAY TRY TO
SHUNT DOWN A WEAKENING SFC BOUNDARY DOWN TOWARD OR ACRS THE CWA
LATER SUNDAY NIGHT OR MONDAY AND GET SLOWED AS IT ALIGNS PARALLEL TO
MEAN STEERING FLOW. THUS THIS WINDOW MAY BE THE NEXT REAL CHANCE FOR
SOME PRECIP IN THE AREA AFTER TODAY/TONIGHT. LONGER RANGE SIGNALS ON
THE LATEST RUNS ESPECIALLY THE NEW 00Z ECMWF SUGGESTS THAT THIS
BROAD UPPER RIDGING PATTERN TO CONTINUE TO REIGN ACRS MUCH OF THE
CONUS WELL INTO MID NEXT WEEK...WHILE THE TROPICS CONTINUE TO GET
INTERESTING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 643 AM CDT TUE JUL 9 2013
SHOWERS AND STORMS WILL MOVE ACROSS THE AREA THROUGH EARLY AFTN
AFFECTING KCID...KDBQ AND KMLI TERMINALS. MVFR TO LOCAL IFR
CONDITIONS MAINLY FOR VSBYS 1-5SM WITH PCPN. HAVE VCSH WORDING
FURTHER SOUTH AT KBRL WITH LESS CERTAINTY ON COVERAGE AND IMPACT
TO TERMINAL. ANOTHER ROUND OF SHOWERS AND STORMS IS LIKELY LATE
THIS AFTERNOON AND TONIGHT AHEAD OF A COLD FRONT. STRONG TO SEVERE
WINDS COULD ACCOMPANY SOME OF THE STORMS. ADDITIONAL SHOWERS COULD
LINGER OVERNIGHT IN WAKE OF FRONTAL PASSAGE. LOW RISK OF MVFR CIGS
LATE TONIGHT WITH PROBABILITY APPEARING TOO LOW ATTM FOR INCLUSION
IN TAFS. OUTSIDE OF ANY STORMS... WINDS TODAY TO BECOME SSW AROUND
10 KTS AND MAY BE GUSTY AT TIMES. WINDS TO SHIFT TO NORTHWEST WITH
FRONTAL PASSAGE LATE TNGT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...ERVIN
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
750 AM CDT TUE JUL 9 2013
.UPDATE...
ISSUED AT 743 AM CDT TUE JUL 9 2013
SHOWERS AND STORMS ON MORE SCATTERED BASIS HAVE FILLED BACK IN
TO WESTERN IA. BASED ON THIS TREND CONCERN IS MOUNTING THAT WE
MAY JUST SEE OCCASIONAL SHOWERS AND STORMS ALL DAY. SHOULD THIS
OCCUR IT WOULD AID IN KEEPING HIGH TEMPS COOLER THAN FCST... AND
ALSO WOULD HAVE MAKE COVERAGE OF STORMS ALONG FRONT AND SEVERE
THREAT LATE AFTN/EVE MUCH MORE UNCERTAIN. NO MAJOR CHGS MADE WITH
7 AM UPDATE BUT WILL PASS ON CONCERNS TO NEXT SHIFT.
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 9 2013
06Z MSAS SFC ANALYSIS SUPPORTIVE OF WEAK LOW OVER CENTRAL SD WITH
STATIONARY FRONT EXTENDING SEWD FROM THE LOW AND BISECTING
EASTERN IA AND NORTHWEST IL. MOISTURE IS POOLING ALONG THE FRONT
WITH DEWPTS OF 70-75F. 00Z KDVN RAOB SHOWS DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES OF NEARLY 2 INCHES... WHICH IS AROUND 160
PERCENT OF NORMAL AND NEARLY 2 STANDARD DEVIATIONS ABOVE THE MEAN.
CONVECTIVELY ENHANCED VORT MAX IS TRACKING THROUGH EASTERN NE ATTM
WITH RADARS SHOWING SHOWERS AND STORMS AHEAD OF THIS FEATURE INTO
WESTERN IA. ADDITIONAL COMPLEX OF STORMS WAS OVER THE DAKOTAS
AHEAD OF COLD FRONT AND SHORTWAVE MOVING EAST THROUGH FAR SOUTHERN
ALBERTA PROVINCE AND NORTHERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 9 2013
SUGGESTIONS OF 2 MAIN ROUNDS OF STORMS THROUGH THE PERIOD. AS
CONVECTIVELY ENHANCED VORT MAX MOVES EAST FROM NE ANTICIPATE
SHOWERS AND STORMS TRACKING AHEAD OF THIS FEATURE TO MOVE ACROSS
THE REGION BY MID AM THROUGH EARLY AFTN. PRIOR TO THE ARRIVAL
OF THESE STORMS COULD SEE ADDITIONAL DEVELOPMENT PRIOR TO MID AM
OVER THE AREA WITH WARM ADVECTION WING. POTENTIAL FOR SOME
STRENGTHENING OF MID LEVEL WINDS AND INTENSIFICATION OF STORMS
BY LATE AM AND AFTN FOR RISK OF FEW STRONG TO ISOLD SEVERE STORMS
WITH MOST RECENT RUNS OF HRRR 2-5KM UPDRAFT HELICITY AND 3 KM
VELOCITY CONTINUING TO SUGGEST THIS RISK NEAR AND ESPECIALLY NORTH
OF I-80. MAY SEE BREAK IN ACTION OR RELATIVE LULL IN ACTIVITY
BY MID-LATE AFTN WITH FOCUS SHIFTING BACK NORTHWEST FOR DEVELOPMENT
AHEAD OF COLD FRONT. LIKELY TO SEE ANOTHER ROUND OF STORMS MOVE
THROUGH THIS EVENING INTO OVERNIGHT AHEAD OF COLD FRONT.
STRENGTHENING 40-60 KT MID LEVEL SPEED MAX SPREADING BEHIND FRONT
COUPLED WITH VERY UNSTABLE ENVIRONMENT WILL SUPPORT RISK OF SEVERE
STORMS WITH POTENTIAL FOR UPSCALE GROWTH TO LINEAR MCS WITH MAINLY
DAMAGING WIND THREAT. HEAVY RAIN WILL BE A CONCERN AS WELL GIVEN
THE DEEP ALMOST TROPICAL MOISTURE IN PLACE. STORMS SHOULD BE MOVING
ALONG MORE THAN WE/VE SEEN OF LATE BUT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH RATES LIKELY 1-2"/HR. THUS... CANT RULE OUT SOME
LOCALIZED FLASH FLOODING AND WILL HAVE TO BE ESPECIALLY WATCHFULL
OVER PORTIONS OF DELAWARE AND DUBUQUE COUNTIES WHICH HAVE SEEN 2-5
INCHES PAST 24-36 HRS. EXPECT PCPN SHOULD BE DIMINISHING FROM NW
TO SE OVRNGT WITH PASSAGE OF COLD FRONT.
HIGHS TDY TRICKY WITH CLOUDS AND PCPN BUT OVERALL SHOULD RANGE FROM
MID 80S TO THE LOWER 90S. SOME MIXING OUT OF DEWPTS MAY OCCUR BUT
AT LEAST UPPER 60S TO LOWER 70S EXPECTED ON DEWPTS... WHICH COMBINED
WITH TEMPS WILL MAKE FOR HEAT INDICES MAINLY IN THE MID TO UPPER 90S.
COOLER AND DRIER AIR LAGS BEHIND FRONT TNGT... THUS LOWS ONLY DROP
INTO THE UPPER 60S TO LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUL 9 2013
WEDNESDAY AND THURSDAY...AS L/W TROF CONTINUES TO DEEPEN AND
ESTABLISH ACRS THE GRT LKS...SEASONABLY STRONG LLVL HIGH PRESSURE
WILL LOOK TO DUMP DOWN THE NORTHERN PLAINS AND MO RVR VALLEY ON WED.
A FEW POST-FRONTAL SHOWERS AND STORMS MAY BE OCCURRING ACRS THE FAR
EASTERN/SOUTHERN CWA WED MORNING BUT BULK OF THE ACTIVITY SHOULD BE
GONE BY 15Z. VEERING AND INCREASING BOUNDARY LAYER FLOW AS WELL AS
INCOMING SUBSIDENCE SHOULD CLEAR THINGS OUT ON WED...BUT SOME LAG IN
CAA TO ALLOW TEMPS TO WARM INTO THE LOW TO MID 80S EVEN POST-
FRONTALLY. A RATHER BREEZY NORTHWEST TO NORTH WIND OF 15-20 MPH.
CLEAR SKIES AND WIND DROP OFF WED NIGHT TO ALLOW SOME AREA TEMPS TO
DROP OFF INTO THE 50S. LLVL HIGH PRESSURE CONTINUING TO MIGRATE
EASTWARD ACRS THE REGION TO MAKE FOR A CHAMBER OF COMMERCE DAY THU
WITH HIGHS IN THE UPPER 70S TO LOWER 80S...SUNSHINE AND LOWER
HUMIDITY. THU NIGHT SEASONABLY COOL AGAIN WITH LOWS IN THE 50S AND
LOW 60S.
FRIDAY THROUGH NEXT MONDAY...TRENDS OF THE LATEST RUN 00Z MEDIUM
RANGE SOLUTIONS AND ENSEMBLES SUGGEST SOME DIGGING TROFFINESS IN THE
PACIFIC NORTHWEST/WESTERN CANADA TO TRANSLATE INTO PUMPED UP UPPER
RIDGING ACRS THE MID CONUS FRI INTO SAT. THUS WHILE THERMAL DOME
INTENSIFIES ACRS THE GRT BSN INTO THE SOUTHWESTERN PLAINS...MCS
TRACK/RING OF FIRE PATTERN TO ESTABLISH IN NORMAL DEEP SUMMER
LOCATION OF NORTHWESTERN HIGH PLAINS...UPPER MS RVR VALLEY...SOUTHERN
CANADA AND INTO THE GRT LKS. LATEST INDICATIONS SUGGEST A LESSENING
CHANCE FOR SOME OF THIS MCS ACTIVITY TO SPILL DOWN ACRS THE
NORTHERN CWA EITHER FRI NIGHT OR SAT NIGHT WHILE TEMPERATURES START
TO REBOUND BACK TO NORMAL OR EVEN WARMER. BY SUNDAY...WESTERLIES
FIRMLY ESTABLISH ACRS THE U.S.-CANADIAN BORDER REGION WITH UPPER
RIDGING DOMINATING ACRS THE SOUTHERN 2/3S OF THE CONUS. LONGER
RANGE THERMAL PROFILES SUGGEST ENOUGH AIRMASS MODIFICATION TO DRIVE
SUNDAY HIGHS UP INTO AT LEAST THE LOWER 90S ALONG WITH INCREASING
SFC DPTS/HUMIDITY. PASSING WAVE IN THIS PROGRESSIVE FLOW MAY TRY TO
SHUNT DOWN A WEAKENING SFC BOUNDARY DOWN TOWARD OR ACRS THE CWA
LATER SUNDAY NIGHT OR MONDAY AND GET SLOWED AS IT ALIGNS PARALLEL TO
MEAN STEERING FLOW. THUS THIS WINDOW MAY BE THE NEXT REAL CHANCE FOR
SOME PRECIP IN THE AREA AFTER TODAY/TONIGHT. LONGER RANGE SIGNALS ON
THE LATEST RUNS ESPECIALLY THE NEW 00Z ECMWF SUGGESTS THAT THIS
BROAD UPPER RIDGING PATTERN TO CONTINUE TO REIGN ACRS MUCH OF THE
CONUS WELL INTO MID NEXT WEEK...WHILE THE TROPICS CONTINUE TO GET
INTERESTING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 643 AM CDT TUE JUL 9 2013
SHOWERS AND STORMS WILL MOVE ACROSS THE AREA THROUGH EARLY AFTN
AFFECTING KCID...KDBQ AND KMLI TERMINALS. MVFR TO LOCAL IFR
CONDITIONS MAINLY FOR VSBYS 1-5SM WITH PCPN. HAVE VCSH WORDING
FURTHER SOUTH AT KBRL WITH LESS CERTAINTY ON COVERAGE AND IMPACT
TO TERMINAL. ANOTHER ROUND OF SHOWERS AND STORMS IS LIKELY LATE
THIS AFTERNOON AND TONIGHT AHEAD OF A COLD FRONT. STRONG TO SEVERE
WINDS COULD ACCOMPANY SOME OF THE STORMS. ADDITIONAL SHOWERS COULD
LINGER OVERNIGHT IN WAKE OF FRONTAL PASSAGE. LOW RISK OF MVFR CIGS
LATE TONIGHT WITH PROBABILITY APPEARING TOO LOW ATTM FOR INCLUSION
IN TAFS. OUTSIDE OF ANY STORMS... WINDS TODAY TO BECOME SSW AROUND
10 KTS AND MAY BE GUSTY AT TIMES. WINDS TO SHIFT TO NORTHWEST WITH
FRONTAL PASSAGE LATE TNGT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
658 AM CDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 9 2013
06Z MSAS SFC ANALYSIS SUPPORTIVE OF WEAK LOW OVER CENTRAL SD WITH
STATIONARY FRONT EXTENDING SEWD FROM THE LOW AND BISECTING
EASTERN IA AND NORTHWEST IL. MOISTURE IS POOLING ALONG THE FRONT
WITH DEWPTS OF 70-75F. 00Z KDVN RAOB SHOWS DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES OF NEARLY 2 INCHES... WHICH IS AROUND 160
PERCENT OF NORMAL AND NEARLY 2 STANDARD DEVIATIONS ABOVE THE MEAN.
CONVECTIVELY ENHANCED VORT MAX IS TRACKING THROUGH EASTERN NE ATTM
WITH RADARS SHOWING SHOWERS AND STORMS AHEAD OF THIS FEATURE INTO
WESTERN IA. ADDITIONAL COMPLEX OF STORMS WAS OVER THE DAKOTAS
AHEAD OF COLD FRONT AND SHORTWAVE MOVING EAST THROUGH FAR SOUTHERN
ALBERTA PROVINCE AND NORTHERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 9 2013
SUGGESTIONS OF 2 MAIN ROUNDS OF STORMS THROUGH THE PERIOD. AS
CONVECTIVELY ENHANCED VORT MAX MOVES EAST FROM NE ANTICIPATE
SHOWERS AND STORMS TRACKING AHEAD OF THIS FEATURE TO MOVE ACROSS
THE REGION BY MID AM THROUGH EARLY AFTN. PRIOR TO THE ARRIVAL
OF THESE STORMS COULD SEE ADDITIONAL DEVELOPMENT PRIOR TO MID AM
OVER THE AREA WITH WARM ADVECTION WING. POTENTIAL FOR SOME
STRENGTHENING OF MID LEVEL WINDS AND INTENSIFICATION OF STORMS
BY LATE AM AND AFTN FOR RISK OF FEW STRONG TO ISOLD SEVERE STORMS
WITH MOST RECENT RUNS OF HRRR 2-5KM UPDRAFT HELICITY AND 3 KM
VELOCITY CONTINUING TO SUGGEST THIS RISK NEAR AND ESPECIALLY NORTH
OF I-80. MAY SEE BREAK IN ACTION OR RELATIVE LULL IN ACTIVITY
BY MID-LATE AFTN WITH FOCUS SHIFTING BACK NORTHWEST FOR DEVELOPMENT
AHEAD OF COLD FRONT. LIKELY TO SEE ANOTHER ROUND OF STORMS MOVE
THROUGH THIS EVENING INTO OVERNIGHT AHEAD OF COLD FRONT.
STRENGTHENING 40-60 KT MID LEVEL SPEED MAX SPREADING BEHIND FRONT
COUPLED WITH VERY UNSTABLE ENVIRONMENT WILL SUPPORT RISK OF SEVERE
STORMS WITH POTENTIAL FOR UPSCALE GROWTH TO LINEAR MCS WITH MAINLY
DAMAGING WIND THREAT. HEAVY RAIN WILL BE A CONCERN AS WELL GIVEN
THE DEEP ALMOST TROPICAL MOISTURE IN PLACE. STORMS SHOULD BE MOVING
ALONG MORE THAN WE/VE SEEN OF LATE BUT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH RATES LIKELY 1-2"/HR. THUS... CANT RULE OUT SOME
LOCALIZED FLASH FLOODING AND WILL HAVE TO BE ESPECIALLY WATCHFULL
OVER PORTIONS OF DELAWARE AND DUBUQUE COUNTIES WHICH HAVE SEEN 2-5
INCHES PAST 24-36 HRS. EXPECT PCPN SHOULD BE DIMINISHING FROM NW
TO SE OVRNGT WITH PASSAGE OF COLD FRONT.
HIGHS TDY TRICKY WITH CLOUDS AND PCPN BUT OVERALL SHOULD RANGE FROM
MID 80S TO THE LOWER 90S. SOME MIXING OUT OF DEWPTS MAY OCCUR BUT
AT LEAST UPPER 60S TO LOWER 70S EXPECTED ON DEWPTS... WHICH COMBINED
WITH TEMPS WILL MAKE FOR HEAT INDICES MAINLY IN THE MID TO UPPER 90S.
COOLER AND DRIER AIR LAGS BEHIND FRONT TNGT... THUS LOWS ONLY DROP
INTO THE UPPER 60S TO LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUL 9 2013
WEDNESDAY AND THURSDAY...AS L/W TROF CONTINUES TO DEEPEN AND
ESTABLISH ACRS THE GRT LKS...SEASONABLY STRONG LLVL HIGH PRESSURE
WILL LOOK TO DUMP DOWN THE NORTHERN PLAINS AND MO RVR VALLEY ON WED.
A FEW POST-FRONTAL SHOWERS AND STORMS MAY BE OCCURRING ACRS THE FAR
EASTERN/SOUTHERN CWA WED MORNING BUT BULK OF THE ACTIVITY SHOULD BE
GONE BY 15Z. VEERING AND INCREASING BOUNDARY LAYER FLOW AS WELL AS
INCOMING SUBSIDENCE SHOULD CLEAR THINGS OUT ON WED...BUT SOME LAG IN
CAA TO ALLOW TEMPS TO WARM INTO THE LOW TO MID 80S EVEN POST-
FRONTALLY. A RATHER BREEZY NORTHWEST TO NORTH WIND OF 15-20 MPH.
CLEAR SKIES AND WIND DROP OFF WED NIGHT TO ALLOW SOME AREA TEMPS TO
DROP OFF INTO THE 50S. LLVL HIGH PRESSURE CONTINUING TO MIGRATE
EASTWARD ACRS THE REGION TO MAKE FOR A CHAMBER OF COMMERCE DAY THU
WITH HIGHS IN THE UPPER 70S TO LOWER 80S...SUNSHINE AND LOWER
HUMIDITY. THU NIGHT SEASONABLY COOL AGAIN WITH LOWS IN THE 50S AND
LOW 60S.
FRIDAY THROUGH NEXT MONDAY...TRENDS OF THE LATEST RUN 00Z MEDIUM
RANGE SOLUTIONS AND ENSEMBLES SUGGEST SOME DIGGING TROFFINESS IN THE
PACIFIC NORTHWEST/WESTERN CANADA TO TRANSLATE INTO PUMPED UP UPPER
RIDGING ACRS THE MID CONUS FRI INTO SAT. THUS WHILE THERMAL DOME
INTENSIFIES ACRS THE GRT BSN INTO THE SOUTHWESTERN PLAINS...MCS
TRACK/RING OF FIRE PATTERN TO ESTABLISH IN NORMAL DEEP SUMMER
LOCATION OF NORTHWESTERN HIGH PLAINS...UPPER MS RVR VALLEY...SOUTHERN
CANADA AND INTO THE GRT LKS. LATEST INDICATIONS SUGGEST A LESSENING
CHANCE FOR SOME OF THIS MCS ACTIVITY TO SPILL DOWN ACRS THE
NORTHERN CWA EITHER FRI NIGHT OR SAT NIGHT WHILE TEMPERATURES START
TO REBOUND BACK TO NORMAL OR EVEN WARMER. BY SUNDAY...WESTERLIES
FIRMLY ESTABLISH ACRS THE U.S.-CANADIAN BORDER REGION WITH UPPER
RIDGING DOMINATING ACRS THE SOUTHERN 2/3S OF THE CONUS. LONGER
RANGE THERMAL PROFILES SUGGEST ENOUGH AIRMASS MODIFICATION TO DRIVE
SUNDAY HIGHS UP INTO AT LEAST THE LOWER 90S ALONG WITH INCREASING
SFC DPTS/HUMIDITY. PASSING WAVE IN THIS PROGRESSIVE FLOW MAY TRY TO
SHUNT DOWN A WEAKENING SFC BOUNDARY DOWN TOWARD OR ACRS THE CWA
LATER SUNDAY NIGHT OR MONDAY AND GET SLOWED AS IT ALIGNS PARALLEL TO
MEAN STEERING FLOW. THUS THIS WINDOW MAY BE THE NEXT REAL CHANCE FOR
SOME PRECIP IN THE AREA AFTER TODAY/TONIGHT. LONGER RANGE SIGNALS ON
THE LATEST RUNS ESPECIALLY THE NEW 00Z ECMWF SUGGESTS THAT THIS
BROAD UPPER RIDGING PATTERN TO CONTINUE TO REIGN ACRS MUCH OF THE
CONUS WELL INTO MID NEXT WEEK...WHILE THE TROPICS CONTINUE TO GET
INTERESTING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 643 AM CDT TUE JUL 9 2013
SHOWERS AND STORMS WILL MOVE ACROSS THE AREA THROUGH EARLY AFTN
AFFECTING KCID...KDBQ AND KMLI TERMINALS. MVFR TO LOCAL IFR
CONDITIONS MAINLY FOR VSBYS 1-5SM WITH PCPN. HAVE VCSH WORDING
FURTHER SOUTH AT KBRL WITH LESS CERTAINTY ON COVERAGE AND IMPACT
TO TERMINAL. ANOTHER ROUND OF SHOWERS AND STORMS IS LIKELY LATE
THIS AFTERNOON AND TONIGHT AHEAD OF A COLD FRONT. STRONG TO SEVERE
WINDS COULD ACCOMPANY SOME OF THE STORMS. ADDITIONAL SHOWERS COULD
LINGER OVERNIGHT IN WAKE OF FRONTAL PASSAGE. LOW RISK OF MVFR CIGS
LATE TONIGHT WITH PROBABILITY APPEARING TOO LOW ATTM FOR INCLUSION
IN TAFS. OUTSIDE OF ANY STORMS... WINDS TODAY TO BECOME SSW AROUND
10 KTS AND MAY BE GUSTY AT TIMES. WINDS TO SHIFT TO NORTHWEST WITH
FRONTAL PASSAGE LATE TNGT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS GAYLORD MI
953 AM EDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 344 AM EDT TUE JUL 9 2013
THERE WILL BE SMALL CHANCES FOR POP UP SHOWERS AND THUNDERSTORMS
TODAY. BETTER CHANCES OF RAINFALL WILL OCCUR TONIGHT INTO WEDNESDAY
MORNING AS A COLD FRONT APPROACHES THE REGION. HIGH PRESSURE WILL
BEGIN TO BUILD IN BY LATE WEDNESDAY...BRINGING COOLER AND LESS HUMID
CONDITIONS FOR MIDWEEK. A WARMING TREND WILL THEN FOLLOW FOR LATE IN
THE WEEK INTO THE UPCOMING WEEKEND.
&&
.UPDATE...
ISSUED AT 953 AM EDT TUE JUL 9 2013
INTERESTING AND CHALLENGING FORECAST THROUGH LATE AFTERNOON AND
EVENING (SOUNDS LIKE THE TYPICAL NORTHERN MICHIGAN TAGLINE DOESN`T
IT?)...WITH FORECAST ISSUES CENTERED MAINLY ON CLOUD/FOG/TEMP
TRENDS THROUGH MUCH OF THE DAY...BUT SHIFTING TOWARD CONVECTIVE
CHANCES BY LATE AFTERNOON AND EVENING. FIRST OF ALL...WILL JUST
COME RIGHT OUT AND SAY THAT THIS REMAINS A FAIRLY LOW CONFIDENCE
FORECAST WITH REGARD TO ANY CONVECTIVE EVOLUTION LATER
TODAY...WITH EVEN LOWER CONFIDENCE ABOUT ANY SEVERE POTENTIAL.
HOWEVER...STARTING TO GET THE FEELING CONVECTION MAY TRY TO SNEAK
INTO THE PICTURE A LITTLE EARLIER THAN CURRENTLY EXPECTED. MORE ON
THAT BELOW...BUT FIRST THINGS FIRST...WE WILL CONTINUE TO DEAL
WITH WIDESPREAD STRATUS AND GRADUALLY LIFTING FOG THROUGH AT LEAST
LATE MORNING...AND PROBABLY A LITTLE BEYOND. 12Z APX RAOB TELLS
THE STORY...WITH A GOOD DEAL OF MOISTURE SANDWICHED BELOW
900MB...AND IN PARTICULAR BELOW 950MB...COURTESY OF A SHALLOW
INVERSION AND PLENTIFUL BOUNDARY LAYER MOISTURE FROM YESTERDAY`S
MUCH-NEEDED RAINFALL. BASED ON PAST EXPERIENCE...THIS GRUNGE WILL
TAKE SOME TIME TO MIX OUT...AND WILL PROBABLY TRANSITION FROM PURE
STRATUS TO A THICKER STRATOCU DECK AROUND MIDDAY (WON`T TAKE MUCH
TO CONVECTIVELY SATURATE THE 900MB LEVEL PER SOUNDING)...BEFORE
ERODING TO SOME DEGREE AS DRIER AIR ABOVE 875 ATTEMPTS TO MIX IN.
HOWEVER...SATELLITE ANALYSIS ALREADY SHOWING PLENTY OF THICKER
DEBRIS CLOUDS MAKING INROADS THROUGH THE WESTERN LAKES...SO HAVE
TO BELIEVE THINGS WILL CLOUD BACK UP FAIRLY QUICKLY ACROSS THE
WESTERN CWA THROUGH MID AND LATE AFTERNOON. THIS MAKES TEMPS
TRICKY...AND IN GENERAL GUT FEELING SAYS TO LOWER AT LEAST A
COUPLE OF DEGREES...THOUGH WITH THE CAVEAT THAT IT DOESN`T TAKE
MUCH SUN TO SEND READINGS SOARING THIS TIME OF YEAR.
AS FOR PRECIP CHANCES...NOTHING DOING THROUGH AT LEAST 19-21Z...AS
STOUT CAPPING AROUND 750MB AND STUBBORNLY SLOW WARMING (AT LEAST
INITIALLY) WORK IN TANDEM...COUPLED WITH SUBTLE SHORTWAVE
RIDGING ALOFT/NO FORCING. HOWEVER...REALLY WATCHING UPSTREAM
CONVECTIVE ACTIVITY...TIED TO A LEADING SHORTWAVE TRAVERSING
WESTERN MINNESOTA...OUT AHEAD OF THE MAIN UPPER TROUGH AMPLIFYING
INTO THE NORTHERN PLAINS. PER RADAR TRENDS AND SHORT TERM GUIDANCE
HINTS...REALLY STARTING TO GET THE FEELING THAT SOME OF THIS
ACTIVITY SLIDING EAST FROM NORTHERN IOWA MAY TRY TO IMPACT PARTS
OF THE SOUTHERN CWA BY LATE AFTERNOON OR EARLY EVENING. ACTIVITY
IS CURRENTLY TRYING TO OUTRUN THE BETTER INSTABILITY...HOWEVER...
THIS WON`T BE THE CASE FOR LONG AS STRENGTHENING SOUTHERN FLOW
AHEAD OF THE WAVE IS PROGGED TO HELP LIFT A SUBTLE WARM FRONT BACK
NORTH INTO CENTRAL WISCONSIN AND EVENTUALLY PARTS OF NORTHERN
MICHIGAN. THERE ARE INCREASING HINTS OF BETTER POOLED MOISTURE
ALONG THIS BOUNDARY (SEE UPSTREAM DEW POINTS OVER THE SOUTHERN
LAKES IN THE LOW 70S)...WHICH COMBINED WITH AT LEAST A LITTLE
DAYTIME HEATING AND SUBTLE MID LEVEL HEIGHT FALLS MAY BE ENOUGH TO
SUSTAIN THE WARM ADVECTION WING COMPONENT OF THE CURRENT LARGER
UPSTREAM MCS.
LATEST HRRR GUIDANCE REALLY PICKING UP ON THIS IDEA AND GIVEN
CURRENT RADAR MOSAIC...KIND OF HARD TO ARGUE AT THE MOMENT. THIS
IS ESPECIALLY TRUE WITH FURTHER HINTS THAT A LOCALIZED LOW LEVEL
JET MAXIMUM MAY ALSO POKE INTO THE SOUTHWEST CWA OFF LAKE
MICHIGAN...COINCIDENT WITH THE ARRIVAL OF SOMEWHAT BETTER MID
LEVEL LAPSE RATES (STILL NOTHING STELLAR) AND BETTER LOW LEVEL
THETA-E RIDGING. HAVE RE-WORKED POPS TO SHOW THIS IDEA BETTER.
DON`T ANTICIPATE A BIG SEVERE THREAT THROUGH 00Z WITH RATHER SLACK
WIND FIELDS (DEEP SHEAR ONLY ABOUT 20 KNOTS) AND LIMITED
INSTABILITY (MIXED LAYER CAPE UP AROUND 700 J/KG).
UPDATE ISSUED AT 629 AM EDT TUE JUL 9 2013
DENSE FOG HAS EXPANDED OVER THE LAST HOUR OR SO..AND AN SPS HAS
BEEN ISSUED FOR LESS THAN A QUARTER OF A MILE VISIBILITIES. THE
WORST OF VISIBILITY REDUCTION WAS FOCUSED IN THE COASTAL
COMMUNITIES SURROUNDING LAKES MICHIGAN AND HURON. TEMPERATURES
WILL BE AT A STAND-STILL FOR THE NEXT SEVERAL HOURS...AS THE
STRATUS WILL GO NOWHERE FOR MOST OF THE MORNING. THERE HAVE BEEN
NO RAIN SHOWERS FOR THE LAST SEVERAL HOURS...AND NEWER DATA COMING
IN...IF ANYTHING...SUGGEST MAYBE EVEN A STRONGER CAP TO PREVENT
AFTERNOON SHOWERS AND STORMS. WILL PLAY IT SAFE HERE THOUGH AND
KEEP SLIGHT CHANCES IN THE FORECAST...FOR THE MERE FACT THAT WE
WILL HAVE DEVELOPED LAKE BREEZES AND A PIECE OF SHORTWAVE ENERGY
THAT COULD POSSIBLY OVERCOME CAPPING...ALTHOUGH IT DOESN`T LOOK
LIKE IT. BELIEVE THERE WILL BE AFTERNOON SUN...EVENTUALLY FOR
TEMPERATURES TO MAKE IT INTO THE 80S....BUT WILL DROP EXPECTED
HIGHS A COUPLE DEGREES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 344 AM EDT TUE JUL 9 2013
CURRENTLY...WEAK LOW PRESSURE WAS WORKING EASTWARD ACROSS NE
LOWER...WITH SHOWER ACTIVITY VANISHING AFTER LOSS OF HEATING.
MOISTURE HAS BEEN STRIPPED OUT ALOFT AND THE BL REMAINS MOIST.
RADIATIONAL COOLING ON TOP OF THIS BL MOISTURE HAS RESULTED IN
WIDESPREAD STRATUS...AS FAR OUT AS WISCONSIN. THIS STRATUS WAS ALSO
UNDERNEATH A DEVELOPING CAP DUE TO SUBSIDENCE AND SFC HIGH PRESSURE
BETWEEN DEPARTING LOW...AND UPSTREAM NEXT LOW PRESSURE AND COLD
FRONT. THIS LOW WAS IN FAR NW ONTARIO...WITH ITS COLD FRONT DRAPED
DOWN THROUGH NORTH DAKOTA. THERE WAS RELATIVE DRY AIR AND NO PRECIP
YESTERDAY WITHIN THE HIGH PRESSURE.TEMPERATURES IN THE STRATUS HAS
FLAT-LINED...IN THE UPPER 60S FOR MOST.
TODAY...NEW DATA INDICATING THE BL MOISTURE IS QUITE MOIST AND THICK
ENOUGH FOR THE SOLID STRATUS TO CONTINUE WELL INTO THE MORNING. WILL
KEEP SKIES CLOUDY ALL MORNING...BEFORE HEATING CAN FINALLY RESULT IN
HOLES AND A PRETTY GOOD COVERAGE OF CUMULUS. THERE SEEMS TO BE QUITE
THE CHANGE IN EXPECTATIONS FOR PRECIPITATION DEVELOPMENT FOR THIS
AFTERNOON. A CAP DEVELOPS AT 750MB...VERIFIED BY 00Z UPSTREAM
SOUNDINGS ACROSS MINNEAPOLIS/GREEN BAY. USING A PARCEL OF 88/67 WILL
RESULT IN ROUGHLY 1400 J/KG SBCAPE AND ONLY A FEW HUNDRED J/KG
MLCAPE (WHICH MAY BE BETTER CONSIDERING THE DRYNESS OF THE ENTIRE
BL). THUS...CHANCES FOR SEEING ANY SORT OF DIURNAL SHOWERS AND
THUNDERSTORMS HAVE DRASTICALLY DWINDLED DUE TO A SIGNIFICANT AMOUNT
OF CAPPING/WARM AIR ALOFT. WILL JUST KEEP A 20 PERCENT CHANCE FOR
THE LATE AFTERNOON AND EVENING. HIGHS SHOULD MAKE A LATER DAY RUN AT
THE MIDDLE AND UPPER 80S.
TONIGHT...AFTER ANY DIURNAL CONVECTION WANES...WE WILL BE AWAITING
THE MAIN SHOW. THE FAR NRN ONTARIO LOW PRESSURE MOVES EAST AND THE
TRAILING COLD FRONT WILL BE MARCHING FROM FAR WESTERN WISCONSIN AND
INTO/NEAR EASTERN UPPER/LAKE MICHIGAN BY 12Z. STRONGER SHORTWAVE
ENERGY AND NICE UPPER DIVERGENCE SIGNAL WILL WORK IN CONCERT WITH
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE FRONT...TO FIRE OFF
SHOWERS AND STORMS FOR THE OVERNIGHT. THESE STORMS WILL HAVE BEEN
GENERATED ACROSS WISCONSIN IN THE AFTERNOON...BUT EVEN WITH LOSS OF
HEATING...THE UPPER FORCING OUGHT TO SUSTAIN THUNDER. MUCAPES ARE
PRETTY MINIMAL...IN THE FEW HUNDREDS OR SO...AND WILL DOWNPLAY THE
AMOUNT OF THUNDER WITH THE RAIN SHOWERS. THE BETTER/DEEPER
INSTABILITY WILL BE WELL SOUTH OF US...IN HIGHER THETA-E AIR ACROSS
NRN IL/INDIANA. THE CONVECTION THERE MAY ALSO SERVE TO ROB US OF
SOME MOISTURE...ALTHOUGH PWATS ARE EXPECTED TO BE HIGH...1.80" TO
ALMOST 2.00" LIQUID. STRATUS AND FOG WILL ALSO BE A CONCERN IN JUICY
AIR MASS...BEFORE DRYING SETS IN ON WEDNESDAY. LOWS IN THE MID/UPPER
60S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 344 AM EDT TUE JUL 9 2013
AN UPPER LEVEL TROUGH IN PLACE WEDNESDAY INTO THURSDAY WILL LIFT OUT
OF THE REGION AS A LARGE UPPER LEVEL RIDGE CENTERED ACROSS THE
DESERT SOUTHWEST EXPANDS NORTHEAST INTO THE GREAT LAKES REGION
THURSDAY NIGHT INTO THE WEEKEND. ANOTHER TROUGH MOVING BY TO THE
NORTH WILL THEN BEAT DOWN THIS RIDGE EARLY NEXT WEEK. THIS SCENARIO
WILL RESULT IN COOLER TEMPERATURES FOR MIDWEEK FOLLOWED BY A WARMING
TREND FOR FRIDAY INTO THIS WEEKEND. MEANWHILE...THERE WILL BE MORE
CHANCES OF SHOWERS AND THUNDERSTORMS WEDNESDAY...FOLLOWED BY
PRECIPITATION FREE WEATHER INTO THE WEEKEND. THERE WILL BE SMALL
CHANCES FOR A FEW SHOWERS OR STORMS EARLY NEXT WEEK AS THE TROUGH
MOVES BY. THE MAIN LONG TERM FOCUS IS ON LINGERING POPS WEDNESDAY
THEN POPS AGAIN NEXT MONDAY.
WEDNESDAY...THE SURFACE COLD FRONT CONTINUES TO ADVANCE ACROSS THE
REGION FROM NORTHWEST TO SOUTHEAST WITH DRIER AIR ADVECTING IN
BEHIND IT. IN ADVANCE OF THE FRONT...THE NAM INDICATES 1000-1500
J/KG OF ML CAPE FROM GAYLORD SE TO GLADWIN THROUGH EARLY AFTERNOON.
HOWEVER...THE NAM IS THE MOISTEST MODEL BY FAR WITH THE GFS ET ALL
INDICATING LOTS OF DRY AIR ADVECTION (MEAN 1000-500 MB RH FALLING TO
ABOUT 40 PERCENT OR SO). THEREFORE WILL LEAVE POPS IN THE CHANCE
CATEGORY. POTENTIAL FOR SEVERE STORMS APPEARS LIMITED WITH LIGHT
WIND FIELDS ALOFT. HIGHS RANGING FROM AROUND 70 FAR NORTH TO THE
LOWER 80S SOUTHEAST.
THURSDAY THROUGH MONDAY...THE CORE OF THE UPPER LEVEL COOL POOL IS
OVERHEAD (850 MB TEMPS OF PLUS 8 TO 10 C) BUT FAIRLY DRY AIR (MEAN
1000-500 MB RH 30 TO 40 PERCENT) SHOULD INHIBIT DAYTIME HEATING
DRIVEN SHOWERS FROM FORMING. OTHERWISE...EXTENDED MODELS CONTINUE TO
BE IN GOOD AGREEMENT WITH RIDGING AT THE SURFACE AND SLOWLY BUILDING
HEIGHTS ALOFT LEADING TO ANOTHER PLEASANT AND INCREASINGLY WARM
STRETCH OF WEATHER INTO THE WEEKEND. AN UPPER LEVEL TROUGH AND
ASSOCIATED WEAK COLD FRONT WILL THEN BRING SMALL CHANCES FOR SHOWERS
OR THUNDERSTORMS EARLY NEXT WEEK. HIGHS THURSDAY IN THE MIDDLE TO
UPPER 70S...FRIDAY IN THE MIDDLE 70S TO LOWER 80S...WITH THE UPPER
70S TO MIDDLE 80S FOR SATURDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 629 AM EDT TUE JUL 9 2013
IFR CONDITIONS ARE GOING TO CONTINUE THROUGH MUCH OF THE MORNING
AS STRATUS AND FOG WILL BE VERY STUBBORN TO LIFT. BL MOISTURE IS
FAIRLY SUBSTANTIAL AND HEATING THROUGH IT TO HELP CLEAR SKIES OUT
WILL BE MINIMAL FOR AWHILE. DO BELIEVE VFR CONDITIONS WILL DEVELOP
LATER THIS AFTERNOON...BUT CHANCES FOR SEEING SHOWERS AND STORMS
IN THE AFTERNOON AND EVENING ARE QUITE SMALL...AS WARM AIR ALOFT
HAS CAPPED THINGS OFF QUITE WELL. NEWER DATA ROLLING IN FURTHER
SUGGEST THINGS WILL BE QUIET. HOWEVER...THE MAIN SHOW WILL STILL
BE LATER TONIGHT...LIGHT WINDS EARLY AND THE DEVELOPMENT OF LIGHT
FOG IN PERHAPS A PERIOD OF CLEARING...WILL TURN ACTIVE. AN
UPSTREAM LOW PRESSURE AND COLD FRONT WILL ARRIVE IN EASTERN UPPER
AND LAKE MICHIGAN BY 12Z. SHOWERS AND STORMS OUT AHEAD OF THIS
FRONT WILL ROLL THROUGH NW LOWER AROUND 06Z...AND APN AROUND 09Z.
THERE IS A SLIGHT CHANCE THAT TVC/MBL COULD SEE A SEVERE
STORM...BUT DO BELIEVE THAT THIS IS A VERY SMALL CHANCE.
&&
.MARINE...
ISSUED AT 344 AM EDT TUE JUL 9 2013
WINDS WILL CONTINUE TO BE VARIABLE AND LIGHT THROUGH TONIGHT UNDER
STABLE CONDITIONS ON THE LAKES. UPSTREAM COLD FRONT WILL APPROACH
OVERNIGHT AND INTO WEDNESDAY FOR SHOWERS AND STORMS...AND BEHIND THE
FRONT WINDS WILL SHIFT TO OUT OF THE NW. MAYBE HAVE SOME ADVISORY
LEVEL GUSTS AT PRESQUE ISLE...SSM/ST MARYS. WINDS WILL LIGHTEN UP
OVER TIME THEN...AS HIGH PRESSURE GRADUALLY WORKS IN OVER NRN
MICHIGAN LATE THIS WORK WEEK...AND THE WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...SD
MARINE...SD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
845 AM EDT TUE JUL 9 2013
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 844 AM EDT TUE JUL 9 2013
CURRENTLY (830 AM) THERE ARE TWO LINES OF THUNDERSTORMS HEADED
TOWARD SOUTHWEST LOWER MICHIGAN. IF THE LINE CONTINUED TO PROGRESS
AS IT IS... IT WOULD REACH HOLLAND AROUND 2 PM THIS AFTERNOON.
HOWEVER LOOKING AT RAP MODEL SOUNDINGS WE STILL HAVE A SIGNIFICANT
DRY LAYER FROM 6000 FT TO 15000 FT THAT WOULD HAVE TO BE
OVERCOME. ALSO THE AREA OF SATURATED LIFT IN THE DGZ ON THE RAP
MODEL NEARLY PERFECTLY MATCHES THE LIGHTING ACTIVITY OVER THE
PAST 4 HOURS... AND THAT AREA DOES NOT REACH SOUTHWEST LOWER
MICHIGAN THROUGH 5 PM. ACTUALLY THE NORTHERN AREA HEADS TOWARD THE
UPPER PENINSULA AND THE SOUTHERN AREA HEADS TOWARD CHI AND MKE.
ALSO THE LOW LEVEL JET WEAKENS AS IT COMES TOWARD SOUTHWEST LOWER
MICHIGAN. BOTH THE HRRR AND RAP MODEL DO NOT BRING THE
THUNDERSTORMS INTO OUR CWA THROUGH 5 PM. THE HRR TAKES THE
SOUTHERN AREA INTO BERRIEN COUNTY AROUND 6 PM. ONE OTHER ASPECT TO
THIS IS THE DEEP LAYER SHEAR IS UNDER 20 KNOTS THROUGH 8 PM OVER
ALL OF THE SOUTHERN 2/3 OF LOWER MICHIGAN SO THAT WILL HELP TO
KEEP THE STORMS FROM GETTING TO ORGANIZED.
SO MY SPIN ON THIS IS THAT LINE... IF IT GETS HERE WILL BE RATHER
WEAK AND DISSIPATING DUE TO THE CAP CREATED BY THE DEEP DRY LAYER.
THERE COULD BE SOME STRONG STORMS OVER OUR EXTREME SOUTHWEST
COUNTIES TOWARD DINNER TIME.
&&
.SYNOPSIS...
ISSUED AT 335 AM EDT TUE JUL 9 2013
MOST OF THE DAY TODAY SHOULD SEE A GOOD DEAL OF SUNSHINE AND VERY
WARM AND HUMID TEMPERATURES AFTER MORNING LOW CLOUDS AND FOG
DISSIPATE. THERE WILL BE A SLIGHT CHANCE OF A STORM DURING THE
AFTERNOON HOURS. THE BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND
STORMS WILL COME TOWARD AND AFTER MIDNIGHT TONIGHT AS A WAVE OF LOW
PRESSURE MOVES THROUGH THE AREA.
THE CHANCE OF RAIN WILL DIMINISH THROUGH THE DAY ON WEDNESDAY AS A
COLD FRONT PUSHES SOUTH THROUGH THE AREA. TEMPERATURES WILL BE A BIT
COOLER WEDNESDAY AFTERNOON. EVEN COOLER TEMPERATURES AND DRY
CONDITIONS WILL BE FOUND FOR THE REMAINDER OF THE WEEK BEFORE WE
START TO WARM UP AGAIN THIS COMING WEEKEND.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN ISSUE IN THE SHORT TERM IS FOG THIS MORNING...THEN STORM
POTENTIAL AND SEVERE THREAT FOR LATE TODAY AND TONIGHT.
A FAIR AMOUNT OF FOG AND LOW CLOUDS HAVE DEVELOPED OVER THE NRN
SECTION OF THE CWFA EARLY THIS MORNING. SOME OF THIS IS STARTING TO
DEVELOP FURTHER SOUTH AS A WEAK SFC TROUGH CRAWLING SOUTH ACROSS THE
AREA IS LIKELY BEING OVERRUN A BIT JUST OFF THE SFC AND WITH THE
HUMID AIR MASS IN PLACE. WE DO EXPECT THAT THIS WILL DISSIPATE
DURING THE MID MORNING HOURS AS THE STRONG SUN ANGLE WORKS ON THE
SHALLOW LAYER OF MOISTURE.
WE EXPECT TO SEE A GOOD DEAL OF SUNSHINE AFTER THE LOW CLOUDS AND
FOG DISSIPATE. THE AREA WILL BE UNDER THE INFLUENCE OF SHORT WAVE
RIDGING ALOFT BETWEEN THE DEPARTING WAVE FROM YESTERDAY AND THE NEXT
WAVE EXPECTED TONIGHT. FCST SOUNDINGS SHOW A WARM LAYER BETWEEN
850-700MB THAT SHOULD CAP MOST IF NOT ALL CONVECTIVE DEVELOPMENT
THROUGH ALMOST 00Z. WE CAN NOT RULE OUT AN ISOLATED SHOWER/STORM
DEVELOPING ALONG A BOUNDARY LIKE A LAKE BREEZE. THAT SAID...THE LOW
LEVEL FLOW LOOKS FAIRLY DIVERGENT DURING THE DAY TODAY WHICH SHOULD
LIMIT ANY DEVELOPMENT ALSO.
THE AREA STILL LOOKS LIKE IT IS ON TRACK FOR A BATCH OF SHOWERS AND
STORMS TO MOVE THROUGH TONIGHT. THE BEST CHANCE WILL OCCUR ALONG AND
SOUTH OF INTERSTATE 96. OUR FOCUS IS ON THE SHORT WAVE PRODUCING
CONVECTION ACROSS THE DAKOTAS...AND THE EVENTUAL LLJ THAT IS
EXPECTED TO DEVELOP THIS EVENING/OVERNIGHT.
WE DO EXPECT THE SHORT WAVE TO MOVE INTO THE AREA TOWARD 06Z. IT
SEEMS THAT THE CONVECTION ACROSS THE DAKOTAS SHOULD SLOWLY MOVE
THROUGH THE DAY. WE COULD SEE IT INTENSIFY A BIT IN WISCONSIN THIS
AFTERNOON AS IT ENCOUNTERS BUILDING INSTABILITY THERE. THIS LINE
WILL LIKELY DIMINISH SOME AS IT HEADS TOWARD OUR CWFA TONIGHT WITH
THE LOSS OF DIURNAL INSTABILITY.
WHAT WE WILL SEE IS THE LLJ INCREASE A BIT AND THE NOSE BE AIMED AT
THE SRN HALF OF THE CWFA BY 06Z. THIS SHOULD HELP MAINTAIN A FAIRLY
DECENT AREA OF SHOWERS AND STORMS THAT WOULD LAST INTO THE DAYBREAK
HOURS ON WED BEFORE MOVING OUT. SEVERE THREAT DOES NOT SEEM VERY
IMPRESSIVE DUE TO THE LATE NIGHT TIME FRAME THE CONVECTION WOULD BE
MOVING IN. FCST SOUNDINGS INDICATE THAT THE CAPE IN THE -10 TO -30C
LAYER IS NOT REAL ABUNDANT. DEEP LAYER CLOUD LAYER SHEAR IS ON THE
LOWER SIDE AROUND 20-25 KNOTS OR SO. MOST OF THE STORMS WOULD BE
ELEVATED WITH SOME POSSIBILITY OF SOME WINDS MAKING IT DOWN WITH
SOME RESIDUAL LOW LEVEL INSTABILITY.
WE FEEL THAT IF THE STORMS MOVE THROUGH AS EXPECTED TONIGHT...MOST
OF THE CWFA WILL BE WORKED OVER ENOUGH FOR WED THAT THE THREAT OF
STORMS AND SEVERE WEATHER IS LOW. IT WILL TAKE A WHILE TO BUILD UP
THE INSTABILITY...AND THE FRONT SHOULD CLEAR THE CWFA BY PEAK
HEATING. THE BEST CHC FOR STORMS WILL BE DOWN SOUTH WHERE LOCATIONS
DO NOT SEE MCS ACTIVITY TONIGHT.
WE WILL SEE SKIES CLEAR THEN WED EVENING AND CONTINUE THROUGH THU AS
DRIER AND COOLER AIR MOVES IN. A SHORT WAVE DOES MOVE THROUGH FROM
THE NW ON THU...HOWEVER THE AIR SHOULD BE DRY ENOUGH AND WE WILL BE
ON THE DOWNSTREAM SIDE OF THE LONG WAVE RIDGE TO OUR WEST TO KEEP US
DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE ARRIVAL OF MID LEVEL RIDGING EARLY IN THE PERIOD SUPPORTS A DRY
PATTERN FOR THE REGION THEN. SUBSIDENCE IS SEEN ON BUFKIT OVERVIEWS
AND MOISTURE PROFILES REMAIN DRY THROUGH SAT. A WARM AIR ADVECTION
PATTERN SETS UP BY SUNDAY AND PWAT VALUES WILL BE ON THE INCREASE.
A WEAKENING SURFACE FRONT SLIPS DOWN FROM THE NORTHWEST SUNDAY NIGHT
INTO MONDAY. WITH SOME ELEVATED/SURFACE INSTABILITY ALONG OR AHEAD
OF THE FRONTAL ZONE...THERE COULD BE A FEW STORMS.
THE BELOW NORMAL TEMPERATURES TO START THE PERIOD TRANSITION TO
ABOVE NORMAL VALUES FOR THE END OF THE PERIOD. TEMPERATURE VALUES
AT 925 MB CLIMB INTO THE LOW TO MID 20 DEG C RANGE SUNDAY. WITH
SOME SUN...WE SHOULD EASILY REACH THE MID 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 739 AM EDT TUE JUL 9 2013
LOW CLOUDS WILL BE SLOW DO DISSIPATE ESPECIALLY CLOSER TO THE
LAKESHORE THIS MORNING. IMPACTS TO PERSIST WITH IFR/LIFR COMMON TO
START. BY 16Z CONDITIONS AT MOST SITES SHOULD BE MVFR.
LINE OF STORMS TRACKING THROUGH NRN IOWA WILL ARRIVE IN WRN MI
AFTER 19Z IF THEY SURVIVE. UNSTABLE CONDITIONS PERSIST MUCH OF THE
NIGHT. SO TAFS WILL FEATURE THE POSSIBILITY OF A STORM THROUGH THE EVENING.
&&
.MARINE...
ISSUED AT 335 AM EDT TUE JUL 9 2013
NO HEADLINES WILL BE ISSUED WITH THIS FCST PACKAGE...HOWEVER WE ARE
LOOKING AT FOG POTENTIAL THROUGH TONIGHT...ROUGH WEATHER TONIGHT
WITH A POSSIBLE ROUND OF STORMS...AND THEN SOME DECENT WINDS
POSSIBLE WED BEHIND THE FRONT.
THE LIGHT GRADIENT OVER THE LAKE THIS MORNING ALONG WITH THE HUMID
AIR MASS OVER THE SOMEWHAT COOL WATER IS LIKELY PRODUCING SOME FOG.
WEBCAMS SHOW SOME PLACES SEEING FOG WHILE OTHERS ARE NOT. WE DO NOT
FEEL CONFIDENT ENOUGH AT THIS TIME TO ISSUE A MARINE FOG ADVISORY...
HOWEVER IT IS SOMETHING WE WILL NEED TO MONITOR.
WINDS AHEAD OF THE WAVE MOVING IN TONIGHT WILL HAVE THE POTENTIAL TO
INCREASE THE WINDS AND WAVES SOME TONIGHT. THE BIGGER THREAT WILL
LIKELY BE THE STORMS THAT ARE ANTICIPATED. THE BEST WIND WILL COME
WITH ANY STORMS. A DECENT NW WIND COULD DEVELOP LATE WED AFTERNOON
BEHIND THE FRONT THAT PUSHES THROUGH. A SMALL CRAFT ADVISORY MAY BE
NEEDED FOR THAT PERIOD.
&&
.HYDROLOGY...
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN PERIOD OF CONCERN AS FAR AS HYDRO IS CONCERNED IS THE
TONIGHT PERIOD. WE WILL SEE PRECIPITABLE WATER INCREASE TO AROUND
2.00 INCHES THIS EVENING AHEAD OF THE WAVE THAT WILL MOVE THROUGH
THE AREA. THIS WILL PROVIDE THE POTENTIAL OF HEAVY DOWNPOURS ACROSS
THE AREA. WE DO NOT ANTICIPATE SIGNIFICANT WIDESPREAD ISSUES AS THIS
WAVE THAT MOVES THROUGH SHOULD BE RATHER PROGRESSIVE. AMOUNTS WILL
LIKELY BE A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL FOR
BASIN AVERAGES...WITH SOME LOCAL AREAS SEEING 1-2 INCHES OF RAIN.
URBAN AND SMALL STREAM ISSUES WILL BE THE MAIN THREAT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT TUE JUL 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 525 AM EDT TUE JUL 9 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS WITH SEVERAL UPSTREAM SHORTWAVE TROUGHS. THE MOST
PROMINENT SHRTWV WAS LOCATED OVER ERN MT WHILE A WEAKER IMPULSE AND
ASSOCIATED MCS WAS MOVING THROUGH ERN SD. AT THE SFC...A WEAK
FRONTAL BOUNDARY LINGERED ACROSS SRN WI WHILE A STRONGER COLD FRONT
AHEAD OF THE MT SHRTWV EXTENDED FROM NW ONTARIO INTO NRN ND. A WEAK
RIDGE EXTENDED FROM QUEBEC ACROSS LAKE SUPERIOR RESULTING IN
LIGHT/CALM WINDS OVERNIGHT. AREAS OF FOG...LOCALLY DENSE...HAS
DEVELOPED AS ABUNDANT LOW LEVEL MOISTURE LINGERED BELOW AN INVERSION
ABOVE 850 MB.
EXPECT THAT THE MORNING WILL BE DOMINATED BY LOW CLOUDS BUT WITH
DAYTIME HEATING/MIXING THE LOW CLOUDS ACROSS MOST OF THE AREA WILL
THIN OUT ENOUGH BY THIS AFTERNOON FOR TEMPERATURES TO CLIMB INTO THE
LOWER 80S INLAND. SATELLITE TRENDS...SHORTER TERM MODELS AND CAPE
GRADIENT...SUGGEST THAT THE ERN SD MCS WILL TRACK TO THE EAST INTO W
AND SRN WI.
THERE IS SOME UNCERTAINTY REGARDING THE IMPACTS OF THE MCS ON
CONVECTION DEVELOPING FARTHER TO THE NORTH. THE FORCING ASSOCIATED
WITH THE APPROACHING NRN PLAINS SHRTWV WITH 100M HEIGHT FALLS AND
MODERATE 700-300 QVECTOR CONV WILL ALSO BE STRONGEST TO THE NORTH OF
THE CWA. HOWEVER...THE SRN END OF THE SHRTWV SHOULD STILL BE STRONG
ENOUGH TO SUPPORT SCT SHRA/TSRA MOVING FROM NW WI INTO WRN UPPER MI
THIS AFTERNOON AND THROUGH THE REST OF THE CWA THIS EVENING.
EXPECTED MAX TEMPS AND DEWPOINTS INTO THE MID TO UPPER 60S GIVE CAPE
VALUES INTO THE 1K-2K J/KG RANGE...GREATEST WEST CENTRAL. 0-6KM BULK
SHEAR VALUES IN THE 30-35 KNOT RANGE WILL BE MARGINAL FOR STRONG/SVR
ORGANIZED CONVECTION BUT WITH TSRA MOVING THROUGH DURING PEAK
HEATING GIVING DCAPE VALUES IN THE 500-1000 J/KG RANGE...SOME
ISOLATED STRONG/DAMAGING WIND GUSTS MAY BE POSSIBLE WITH ANY
STRONGER STORMS. THE HIGHER PROBABILITIES FOR SVR STORMS REMAINS TO
THE SOUTH WHERE THE INSTABILITY IS GREATEST...PER SPC DAY1 OUTLOOK.
THE SHRA/TSRA ARE EXPECTED TO PROGRESS THROUGH THE AREA MOVING INTO
THE ERN CWA LATE THIS EVENING AND ENDING OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE JUL 9 2013
AFTER A FEW DAYS OF WARM AND ACTIVE WEATHER WITH POCKETS OF HEAVY
RAIN OVER MAINLY WESTERN HALF OF CWA...DEVELOPING TROUGHING ALOFT
ACROSS THE GREAT LAKES AND SFC HIGH ON THE WESTERN EDGE OF THE
TROUGH ALOFT WILL BRING QUIET AND COOLER WEATHER MID TO LATE WEEK.
WARMER TEMPERATURES AND INCREASING SHRA/TSRA CHANCES RETURN FOR THE
WEEKEND AS UPPER HEIGHTS BECOME MORE ZONAL.
OVERALL AGREEMENT THAT BEST CHANCE OF SHRA/TSRA ON WEDNESDAY WILL
BE 12-15Z OVER THE FAR EASTERN CWA. STRONGER TSRA STILL POSSIBLE
WITH MUCAPE UP TO 800J/KG. BETTER SHOT FOR SVR WILL BE FARTHER
SOUTH OVER SOUTHERN WI/NORTHERN IL CLOSER TO WEST-EAST FRONTAL
BOUNDARY AND ON NORTHERN GRADIENT OF HIGHER MLCAPES OVR 1000J/KG.
ANY CHANCES OF SHRA/TSRA OVER EAST QUICKLY END THROUGH MORNING AS
STRONG DEEP LAYER Q-VECTOR DIVERGENCE/SUBSIDENCE SURGES ACROSS
UPPER GREAT LAKES. PRESSURE GRADIENT BRIEFLY BECOMES TIGHT BTWN
THE EXITING LOW PRESSURE TROUGH AND HIGH PRESSURE BUILDING OVER
THE PLAINS. EXPECT BRIEF BUILDING WAVES AND INCREASED SWIM RISK
FOR WEDNESDAY OVER THE LK SUPERIOR BEACHES OF ALGER COUNTY AS
WINDS WILL BE FROM THE WEST TO NORTHWEST. WINDS/WAVES AND
ASSOCIATED HIGHER SWIM RISK SUBSIDES BY LATE AFTN WITH LOSS OF
PRESSURE RISES AND TIGHTER PRESSURE GRADIENT.
HIGH PRESSURE REMAINS MAIN WEATHER FEATURE FOR THU/FRI. TEMPS MAY
DROP INTO THE LOW-MID 40S OVER INTERIOR COOL SPOTS ON THURSDAY NIGHT
WITH LGT SOUTHERLY FLOW AS RIDGE AXIS DRIFTS ACROSS. AIRMASS DOES
NOT APPEAR TO BE NEARLY COLD OR DRY ENOUGH FOR ANY FROST POTENTIAL.
HIGH TEMPS BOTH DAYS SHOULD TOP OUT IN THE MID-UPR 70S AWAY FROM THE
GREAT LAKES. MAY EVEN SEE A FEW SPOTS BACK NEAR 80 DEGREES BY
THURSDAY.
UNCERTAINTY ABOUNDS WITH TIMING AND EXTENT OF NEXT ROUND AND/OR
ROUNDS OF SHRA/TSRA THIS WEEKEND INTO NEXT MONDAY. ECMWF NORMALLY
LEADS WAY IN TERMS OF VERIFICATION...BUT BOY ARE ITS SOLUTIONS IN
THE LAST COUPLE DAYS QUITE INCONSISTENT IN TERMS OF TIMING FOR THE
WEEKEND SHRA/TSRA CHANCES. DOES SEEM LIKE ECMWF IS TRENDING TOWARD
SLOWER IDEA SHOWN BY GFS FOR ARRIVAL OF PRECIP FRIDAY NIGHT. WILL
START TO SHOW TREND OF CHANCE POPS ONLY OVER THE FAR WEST LATE ON
FRIDAY NIGHT WHILE IT STAYS MAINLY DRY ELSEWHERE. UPPER HEIGHTS
FLATTEN OUT SATURDAY ALLOWING SHORTWAVES AND MID-LEVEL WIND MAX TO
SLIDE ACROSS UPPER GREAT LAKES REGION. MAIN SFC LOW WILL BE WELL TO
NORTH CLOSER TO SHARPER TROUGH ALOFT...BUT SW LOW-LEVEL FLOW ALONG
WITH INCREASING MOISTURE AND BUILDING INSTABILITY JUST UPSTREAM
SHOULD RESULT IN AT LEAST A CHANCE OF SHRA/TSRA AHEAD OF SFC-H85
TROUGH THAT MOVES THROUGH BY SUNDAY MORNING. WITH WRLY FLOW
ALOFT...FRONT MAY END UP STALLING OUT LATER IN THE WEEKEND PROVIDING
A FOCUS FOR ADDITIONAL SHRA/TSRA. FOR MOST PART USED CONSENSUS
POPS...BUT DID INCREASE POPS SLIGHTLY OVER THE SOUTH AND EAST CWA
CLOSER TO EXPECTED POSITION OF FRONT PER WPC HAND DRAWN SFC PROGS.
BASED ON GENERAL S/SW GRADIENT FLOW AHEAD OF FRONT AND H85 TEMPS IN
THE MID TEENS...INCREASED TEMPS OVER CONSENSUS GUIDANCE. EXPECT MAX
TEMPS FRIDAY THROUGH SUNDAY IN THE MID-UPR 70S TO AS WARM AS MID
80S. IT WILL ALL DEPEND ON EXTENT OF CLOUDS AND SHRA/TSRA. AFTER MIN
TEMPS IN THE 40S AND 50S MUCH OF THIS WEEK...READINGS RETURN TO THE
WARMER/MUGGIER 60S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 733 AM EDT TUE JUL 9 2013
EXPECT DENSE FOG/VLIFR CONDITIONS TO IMPACT CMX/SAW EARLY TODAY MRNG
WITH LGT WINDS/HUMID LLVLS UNDER SFC HIGH PRES/DRIER AIR ALOFT.
DIURNAL HEATING SHOULD ALLOW A GRADUAL RETURN OF VFR WX.
SOME SHRA/TS IN ADVANCE OF A SHORTWAVE AND COLD FRONT WILL ARRIVE OVER
THE WRN IWD/CMX BY LATE AFTERNOON AND THEN MOVE E TOWARD SAW DURING
THE EVENING. ALTHOUGH THE RELATIVE DRYNESS OF THE LOW LEVELS SHOULD
ALLOW PREDOMINANT VFR CONDITIONS...POORER CONDITIONS WILL BE POSSIBLE
UNDER THE HEAVIER SHRA/TS. UPSLOPE WNW FLOW OFF LAKE SUPERIOR IN THE WAKE
OF THE CONVECTION MIGHT CAUSE PREDOMINANT MVFR WX AT
CMX...ESPECIALLY IF HEAVIER RA FALLS NEARBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON JUL 8 2013
DENSE FOG REMAINS A CONCERN ACROSS LAKE SUPERIOR THROUGH TUESDAY
MORNING. LIGHT WINDS AND LITTLE AIR MASS MOVEMENT WILL ALLOW FOR THE
REDEVELOPMENT OF AREAS OF DENSE FOG OVERNIGHT. CLEARING SKIES FOR
TUESDAY MORNING SHOULD ALLOW ENOUGH HEATING TO MIX OUT THE MOST
DENSE FOG BY TUESDAY AFTERNOON. PATCHY FOG WILL THEN LINGER INTO
WEDNESDAY BEFORE A COLD FRONT BRINGS DRIER AIR FROM WEST TO EAST
ACROSS THE LAKE. WINDS SHOULD BE LIGHT AND GENERALLY VARIABLE
THROUGH TUESDAY EVENING. THEN...EXPECT WINDS TO VEER TO THE NW AT 15
TO 25 KNOTS...MAINLY ACROSS THE EAST HALF OF THE LAKE...FOR LATE
TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE WILL THEN BUILD INTO
THE AREA THURSDAY THROUGH SATURDAY AND BRING LIGHT WINDS UNDER 15
KNOTS FOR MUCH OF THE TIME PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS DULUTH MN
923 AM CDT TUE JUL 9 2013
.UPDATE...
FOCUS IN THE SHORT TERM IS COVERAGE OF RAIN/STORMS AND THEIR
INTENSITY.
A LINE OF STRONG-SEVERE STORMS WERE MOVING INTO WEST
CENTRAL/NORTHWEST WISCONSIN AS OF MID MORNING...WITH A KMPX RADAR
SHOWING A A NICE AREA OF OUTBOUND VELOCITY FROM 50-60 KT AT TIMES.
THIS LINE WAS MOVING EAST/NORTHEAST 40-45 MPH. AN AREA OF RAIN
WITH SOME EMBEDDED STORMS EXTENDED NORTH INTO NORTHWEST
MINNESOTA/MANITOBA/NORTHWEST ONTARIO AS WELL. RADAR TRENDS SHOW A
DIMINISHING TREND IN WHAT WAS A MORE ORGANIZED AREA OF
SHOWERS/STORMS WITH FEW RETURNS HEADED FOR THE IRON
RANGE/ARROWHEAD. THE FRONT AND MAIN SHORTWAVE ARE STILL
WEST/NORTHWEST OF THE CWA...SO THERE IS AMPLE LIFT THAT NEEDS TO
MOVE THROUGH THE NORTHLAND YET TODAY AND THAT WILL LEAD TO
ADDITIONAL CHANCES FOR STORMS THROUGH THE DAY. WE WILL CONTINUE TO
MAKE SHORT TERM ADJUSTMENTS TO GRIDS ACCOUNTING FOR RADAR TRENDS.
THE NAM SUGGESTS COVERAGE SHOULD INCREASE THROUGH THE DAY. THE 12Z
KMPX/KINL SOUNDINGS EACH HAD PWAT VALUES OF 1.75 AND 1.41 INCHES.
SPC MESOANALYSIS DEPICTED AROUND 30KT DEEP LAYER SHEAR WITH
500-1500J/KG OF MUCAPE. 11Z HRRR WAS DOING AN OK JOB DEPICTING 14Z
RAIN/STORMS...AND ALSO SHOWS THE RAIN SPLITTING WITH ADDITIONAL
SCATTERED SHOWERS/STORMS DEVELOPING THIS AFTERNOON INTO THE
EVENING.
SHORT TERM SEVERE THREAT WILL BE OVER OUR NORTHWEST WISCONSIN
ZONES OVER THE NEXT 1 TO 3 HOURS...THEN SHIFTS AHEAD OF THE FRONT
THIS AFTERNOON AS IT MOVES THROUGH THE CWA.
&&
.PREV DISCUSSION... /ISSUED 621 AM CDT TUE JUL 9 2013/
AVIATION.../12Z TAF ISSUANCE/
EARLY MORNING LIFR/IFR CONDITIONS DUE TO FOG ACROSS PARTS OF NE
MINNESOTA AND NW WISCONSIN...INCLUDING KDLH AND KHIB...SHOULD LIFT
AND BREAK UP WITHIN THE NEXT FEW HOURS. SHOWERS AND THUNDERSTORMS
ARE LIKELY ACROSS THE NORTHLAND TODAY AND EARLY THIS EVENING. THE
SHOWERS AND STORMS COULD BRING BRIEF MVFR CONDITIONS DUE TO LOW
CIGS AND VSBY RESTRICTIONS FROM RAIN. THE REGION WILL BEGIN TO
CLEAR THIS EVENING AS HIGH PRESSURE BEGINS TO MOVE INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. EXPECT VFR CONDITIONS LATE THIS
EVENING AND WEDNESDAY MORNING. THE VERY LIGHT WINDS WILL INCREASE
LATE THIS AFTERNOON AND THIS EVENING AND BECOME NW IN THE WAKE OF
A PASSING COLD FRONT.
PREV DISCUSSION... /ISSUED 453 AM CDT TUE JUL 9 2013/
SHORT TERM...TODAY AND TONIGHT.
CURRENT REGIONAL RADAR IMAGERY SHOWS A LARGE AREA OF SHRA/TSTORMS
ASSOCIATED WITH A MID-LEVEL TROUGH EXTENDING FROM SRN MANITOBA...ALONG
THE WESTERN MN BORDER...INTO IOWA. AT THIS TIME...THE STRONGEST
STORMS...LOCATED WITH A STRENGTHEN MCS...IS FOUND EXITING EASTERN
SD AND MOVING INTO THE SW PORTION OF MN.
LATEST HIGH RES MODEL RUNS OF THE WRF/HRRR HAVE A RELATIVELY DECENT
HANDLE ON THE CURRENT CONVECTION AND BOTH SHOW THE STORMS
DECREASING SOMEWHAT...BUT OVERALL HOLDING TOGETHER AS THE LINE
MARCHES EAST ACROSS MINNESOTA THIS MORNING. HAVE ADJUSTED POPS
THIS MORNING TO LIKELY USING THE CURRENT DISTANCE/SPEED OF THE
LINE OF STORMS FOR TIMING. AT THE CURRENT SPEED...THE LEADING EDGE
OF THESE STORMS WILL ARRIVE IN THE KINL TO KBRD AREA AROUND 700 TO
800 AM...REACHING A LINE FROM KHIB TO KDLH AND EXTENDING SOUTH
ALONG THE INTERSTATE 35 CORRIDOR AROUND 10-11 AM. THE LIMITING
FACTOR WILL BE IF THE MCS TRACKING ACROSS CENTRAL MINNESOTA CUTS
OFF THE MOISTURE TO STORMS FURTHER NORTH.
SHIFTING FOCUS TO ADDITIONAL THUNDER DEVELOPMENT THIS AFTERNOON
ALONG A SFC COLD FRONT. THE SEVERITY AND COVERAGE OF THE
AFTERNOON CONVECTION WILL BE HIGHLY DEPENDENT ON THE HOW WORKED
OVER THE REGION BECOMES WITH THE STORMS THIS MORNING. HAVE
BROADBRUSH SCT THUNDER OVER MN ZONES...WITH LIKELY ACROSS THE TIP
OF THE ARROWHEAD AND NRN WIS AREAS THROUGH THIS EVENING.
LONG TERM [WEDNESDAY - MONDAY]
THE BEGINNING OF THE PERIOD LOOKS RELATIVELY QUIET. HIGH PRESSURE
AND NW FLOW SHOULD PROVIDE MILD WEATHER AND SUNNY SKIES ACROSS THE
NORTHLAND. WE EXPECT A WARMING TREND LATE THIS WEEK...LIKELY
CULMINATING ON FRIDAY...AS A MID/UPPER LEVEL RIDGE BUILDS INTO THE
UPPER MIDWEST AND SOUTHERLY WINDS INCREASE ACROSS THE NORTHLAND.
MUCH OF THE NORTHLAND...SAVE THE IMMEDIATE NORTH SHORE...SHOULD HAVE
TEMPERATURES AT LEAST IN THE LOW TO MID 80S ON FRIDAY. I INCREASED
THE FRIDAY HIGH TEMPERATURES SINCE I THINK THE MOS GUIDANCE IS TOO
WEIGHTED TOWARDS CLIMATOLOGY...AND WE MIGHT NEED TO INCREASE EVEN
THE HIGHS EVEN MORE.
A COLD FRONT WILL APPROACH THE NORTHLAND LATE THIS WEEK AND THEN
MIGHT STALL OR SLOWLY PROGRESS THROUGH THE REGION THROUGH EARLY NEXT
WEEK. THIS WILL BRING A PERIOD OF SEVERAL DAYS WHERE THE NORTHLAND
WILL HAVE CHANCES OF SHOWERS AND THUNDERSTORMS. FOR NOW...LATE
FRIDAY NIGHT AND SATURDAY MORNING APPEARS TO BE THE PERIOD IN WHICH
THE NORTHLAND WILL HAVE THE GREATEST CHANCES OF SHOWERS AND STORMS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE APPROACHING/PASSING
COLD FRONT WILL BRING WIDESPREAD RAINFALL OF AT LEAST A TENTH TO
QUARTER INCH OF RAIN TO THE NORTHLAND.
&&
.POINT TEMPS/POPS...
DLH 73 55 76 54 / 60 40 0 0
INL 76 54 77 50 / 70 10 0 0
BRD 83 56 79 56 / 70 20 0 0
HYR 83 57 80 51 / 70 60 0 0
ASX 74 55 76 52 / 70 60 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR MNZ020-021-037.
WI...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR WIZ001>003.
LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
710 AM CDT TUE JUL 9 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT TUE JUL 9 2013
MAIN CONCERN IN THE SHORT TERM REVOLVES ON EVOLUTION OF STORMS
CURRENTLY ACROSS THE DAKOTAS THROUGH THE MORNING...FOLLOWED BY WHERE
THUNDERSTORMS REDEVELOP THIS AFTERNOON AND TRAVEL THIS EVENING. IT
IS THE AFTERNOON/EVENING ACTIVITY THAT WILL ALSO HAVE A SEVERE
THREAT. WIND AND HAIL WILL BE THE PRIMARY THREATS...THOUGH DEPENDING
ON WHERE BOUNDARIES ARE LEFT OVER FROM CONVECTION THIS
MORNING...THERE WILL ALSO BE THE SMALL CHANCE FOR TORNADOES ON ANY
LEFT OVER OUTFLOW BOUNDARIES.
AT 3 AM...WE WERE DEALING WITH A BIFURCATED LLJ IN TERMS OF MOISTURE
TRANSPORT MAXIMA...WITH ONE BRANCH DRIVING CONVECTION CURRENTLY
MOVING ACROSS THE DAKOTAS AND THE OTHER DRIVING ANOTHER CLUSTER
ALONG THE NEB/IA BORDER. THIS SRN BRANCH WILL TRACK ACROSS IA
THROUGH THE MORNING...KEEPING THAT CONVECTION SOUTH OF MN WHILE
BECOMING THE MAIN LLJ FOR POTENTIAL AFTERNOON ACTIVITY.
FOR THE MPX AREA...IT IS THE MCS THIS MORNING OVER SODAK THAT WILL
BE OUR PROBLEM. 3Z RAP MUCAPE ANALYSIS SHOWS A RIBBON OF 1000-1500
J/KG OF MUCAPE EXTENDING FROM THE MADISON/CANBY AREA...ESE TROUGH
ROCHESTER AND LA CROSSE. AS A RESULT...ANTICIPATE THIS BAND OF
THUNDERSTORMS WILL CONTINUE ESE ALONG THIS CAPE GRADIENT. AT ITS
CURRENT PACE...SHOULD ENTER WRN MN SHORTLY BEFORE 5 AM...REACH THE
I-35 CORRIDOR BETWEEN 7 AND 8 AM AND EVENTUALLY THE LSE/EAU AREAS BY
LATE MORNING. THE BULK OF THE CONVECTION WITH THIS LINE SHOULD TRACK
SOUTH OF I-94 THIS MORNING. AS FOR SEVERE THREAT...THE STRONG/SEVERE
LINE OF STORMS THAT MOVED ACROSS SODAK HAS NOW MERGED WITH THE WAA
ACTIVITY THAT HAD DEVELOPED OUT AHEAD OF IT...WITH ONE LINE NOW
EVIDENT ON REGIONAL RADAR ANALYSIS. WILL HAVE TO WATCH HOW THIS LINE
EVOLVES OVER THE NEXT HOUR TO SEE WHAT KIND OF SEVERE THREAT IT WILL
POSE. IN THE NEXT HOUR...IF IT BEGINS TO BOW OUT AND
ACCELERATE...THEN A WIND THREAT WILL EXIST THROUGH THE MORNING AS IT
TRACKS ACROSS MN. WITH THE RAP AT 3Z ANALYZING 20-30 KTS OF 0-3KM
SHEAR OUT AHEAD OF THE SYSTEM...IT IS PLAUSIBLE THAT THAT COULD
HAPPEN...THOUGH IN THE END IT MAY BE DIFFICULT TO GET ANY SEVERE
STRENGTH WINDS THROUGH THE STABLE BOUNDARY LAYER...SO AGREE WITH SPC
MCD THAT SEVERE THREAT WILL BE FAIRLY MARGINAL.
FOR THIS AFTERNOON...MANY A QUESTION MARKS STILL REMAIN IN PLACE.
THIS BIGGEST ISSUE IS HOW WILL STORMS THIS MORNING IMPACT WHAT
HAPPENS LATER. THE MAIN QUESTION IS DOES THE ATMOSPHERE HAVE ENOUGH
TIME TO RECHARGE FROM STORMS MOVING THROUGH LARGELY IN THE 10-18Z
TIME FRAME? FIRST WORD OF WARNING FOR THE ARM CHAIR FORECASTERS OUT
THERE...THE CAMS MAY NOT BE ALL THAT RELIABLE FOR WHAT HAPPENS LATER
THIS AFTERNOON AS ALL OF THEM ARE HANDLING CURRENT CONVECTION QUITE
POORLY /INCLUDING ALL MEMBERS OF THE 3Z HOPWRF/. PROBLEM
IS...OUTSIDE OF THE SPCWRF...NONE OF THE CAMS SNOW THUNDERSTORMS
MOVING ACROSS THE AREA OUTLINED IN THE PARAGRAPH ABOVE...MANY
/INCLUDING THE HOPWRF MEMBERS/ HAVE NOTHING MOVING ACROSS THE MPX
AREA THIS MORNING...SO HARD TO PUT MUCH STOCK IN WHAT THEY ARE DOING
THIS AFTERNOON. THE ONLY ONE TO BE SOMEWHAT CLOSE TO REALITY THIS
MORNING /SPCWRF/...SHOWS VERY LITTLE CONVECTION REDEVELOPING IN THE
MPX AREA THIS AFTERNOON.
CERTAINLY A BIG PLUS FOR THE AFTERNOON...IS OVER THE LAST 24
HOURS...MODELS HAVE SLOWED UP THE PROGRESSION OF THE FRONT ACROSS
THE MPX AREA...WHICH LIKELY EXPLAINS WHY HIGHER SEVERE PROBABILITIES
WERE PULLED NORTHWEST WITH THE DAY1 SPC CONVECTIVE OUTLOOK. CURRENT
MODEL BLEND WOULD SAY THE FRONT MOVES INTO THE NW MPX CWA AROUND
20Z...THE TWIN CITIES AROUND 00Z AND FINALLY CLEARS EAU AREA SHORTLY
AFTER 3Z. THIS PUTS THE FRONT ACROSS MUCH OF THE AREA DURING PEAK
HEATING...THOUGH IT IS STILL DEBATABLE HOW MUCH HEATING WE WILL SEE
BEHIND THE MORNING CONVECTION. IF CURRENT FORECAST WERE TO
HOLD...WITH TEMPERATURES REBOUNDING INTO THE MID 80S TO NEAR
90...WITH DEWPS IN THE LOWER 70S...THEN WE SHOULD HAVE NO PROBLEM
GENERATING 2000-3500 J/KG OF MLCAPE AHEAD OF THE BOUNDARY AS THE
NAM/GFS DO. FROM THE SHEAR PERSPECTIVE...A 40-60 KT MID LEVEL JET
MOVING IN WITH THE UPPER WAVE THIS AFTERNOON/EVENING WILL PROVIDE
PLENTY OF DEEP LAYER SHEAR TO SUPPORT UPDRAFT ROTATION AND STORM
ORGANIZATION...BUT THE 0-3KM SHEAR IS LOOKING MORE SUSPECT ACROSS
THE MPX AREA TO REALLY DRIVE UP A TORNADO THREAT. THE REASON FOR THE
POOR LOW LEVEL SHEAR IS THAT THE PRESSURE PATTERN AHEAD OF THE FRONT
WILL BE FAIRLY BAGGY...WITH LIGHT PREFRONTAL WINDS EXPECTED. IN
ADDITION...THE CORE OF A 30-40 KT LLJ WILL EXTEND FROM CENTRAL IA
TOWARD NE WIS...STAYING JUST SE OF THE MPX AREA. COMBINED...THE WEAK
SFC WINDS AND BETTER LLJ BEING JUST SE OF THE MPX CWA RESULT IN
MARGINAL 0-1 KM AND 0-3 KM SHEAR /MAINLY 20 KTS OR LESS/. BESIDE THE
WEAKER SHEAR...THE WEAK SFC WINDS OUT AHEAD OF THE FRONT WILL ALSO
LIMIT THE AMOUNT OF CONVERGENCE ALONG IT...WHICH MAY HELP EXPLAIN
WHY MANY OF THE CAMS /OUTSIDE OF THE 3Z HOPWRF/ STRUGGLE TO GENERATE
MUCH CONVECTION ALONG THE BOUNDARY THIS AFTERNOON.
IN SUMMARY...CONFIDENCE IS HIGH THAT MCS CURRENTLY OVER ERN SODAK
WILL TRACK ACROSS AREAS SOUTH OF I-94 THIS MORNING. BECAUSE OF
THIS...CONFIDENCE IN HOW THE AFTERNOON PLAYS OUT IS CONSIDERABLY
DIMINISHED. BUT...GIVEN FRONTAL TIMING...EXPECT AT LEAST SCT STORMS
TO DEVELOP ALONG THE FRONT BETWEEN 19Z AND 21Z THAT WILL THEN TRACK
SE THIS EVENING WITH THE FRONT. GIVEN DEGREE OF INSTABILITY AND BULK
SHEAR...LARGE HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREAT.
THE WEAKER LOW LEVEL SHEAR MEANS THAT UNLESS A STORM CAN LATCH ON TO
A REMNANT OUTFLOW BOUNDARY...THE TORNADO THREAT APPEARS TO BE
RELATIVELY LOW...THOUGH NOT NEGLIGIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 410 AM CDT TUE JUL 9 2013
THE FIRST HALF OF THE PERIOD WILL START OFF DRY AS LARGE SCALE
SUBSIDENCE DOWNSTREAM OF THE UPPER LEVEL RIDGE AXIS BUILDS AN AREA
OF SURFACE HIGH PRESSURE ACROSS THE UPPER MIDWEST. FORECAST
SOUNDINGS SHOW A DRY PROFILE WITH PWATS ONLY AROUND 0.75
INCHES...ALONG WITH LITTLE POTENTIAL FOR CLOUDS DURING THE DAY ON
WEDNESDAY. WINDS WILL GO CALM OVERNIGHT ALLOWING AN INVERSION TO SET
UP AND TEMPERATURES TO COOL DOWN TO THE UPPER 50S ACROSS MOST
LOCATIONS...WITH LOW 60S EXPECTED IN AND AROUND THE METRO DO TO THE
HEAT ISLAND. THURSDAY WILL BE DRY AS WELL WITH THE SURFACE HIGH
STILL SUPPRESSING ANY CHANCE OF PRECIP. BY THURSDAY NIGHT THE SURFACE
HIGH WILL DRIFT EASTWARD AS THE THERMAL RIDGE APPROACHES FROM THE
WEST...AND SOUTHERLY WINDS ON THE BACK SIDE WILL KEEP OVERNIGHT LOWS
IN THE MID TO UPPER 60S ACROSS WESTERN MINNESOTA. FRIDAY SHOULD BE
MUCH WARMER THAN CURRENTLY FORECAST BY THE NUMERICAL MODELS. BOTH
THE GFS AND ECMWF 09.00 HAVE H850 TEMPS 20-22C...WITH SOUTHERLY
WINDS OF 30KTS...YET FOR SOME REASON THE FORECAST SOUNDINGS ONLY
SHOW MIXING UP TO AROUND 900MB. THIS IS CONTRADICTORY TO THE SIMPLE
PROPERTIES THAT GOVERN THE ATMOSPHERE. GIVEN A MID JULY PROFILE THAT
IS CLOUD FREE...TOGETHER WITH THE POTENTIAL FOR MECHANICAL
MIXING...HAVE VERY HIGH CONFIDENCE THAT AFTERNOON TEMPERATURES WILL
CLIMB INTO THE 90S ACROSS SOUTHWEST MINNESOTA.
ON SATURDAY CONFIDENCE IN TEMPERATURES DECREASES CONSIDERABLY AS A
FRONTAL BOUNDARY/TROUGH OF LOW PRESSURE STALLS OUT FROM SOUTHWEST TO
NORTHEAST OVER THE UPPER MIDWEST. THIS WILL INTRODUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS...WHICH WILL GREATLY AFFECT AFTERNOON
HIGHS. THEREFORE DID NOT STRAY TOO MUCH FROM BLENDED GUIDANCE...AND
CONTINUE TO HAVE CHANCES FOR PRECIP INTO EARLY NEXT WEEK. THE BEST
CHANCE FOR RAIN...WITH 1-3 INCH AMOUNTS VERY LIKELY AT A FEW
LOCATIONS ACROSS THE NORTHWEST NEAR CANBY/ALEXANDRIA/ST CLOUD...WILL
BE LATE FRIDAY NIGHT INTO SATURDAY MORNING. LOOKING AHEAD...THE
THERMAL RIDGE WILL TAKE ON A POSITIVE TILT OVER THE UPPER
MISSISSIPPI RIVER VALLEY. ON SUNDAY THE ECMWF DRIVES A SHORTWAVE
ALONG THE US/CANADIAN BORDER THAT SUPPRESSES THE RIDGE...WHILE THE
GFS IS A DAY SLOWER WITH THIS FEATURE. ALSO...AS ALLUDED TO
EARLIER OVERCAST SKIES WILL GREATLY IMPACT HIGH TEMPS SO DID NOT
HAVE THE CONFIDENCE TO DEVIATE FROM A CONSENSUS APPROACH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM CDT TUE JUL 9 2013
MATURE MCS WORKING ACROSS THE AIRSPACE THIS MORNING MOVING EAST AT
ABOUT 35 KTS HAS BEEN TIMED THROUGH TAFS TO START OUT THIS
MORNING. OTHER THAN A GUST TO 50 KTS AT RWF...ALL SITES TO THE
WEST HAVE BEEN TOPPING OUT AT 40 KTS ON GUSTS. HARD TO SAY WHAT
WILL HAPPEN THIS AFTERNOON AS THERE WILL BE A RECOVERY TIME FROM
MORNING STORMS. HRRR SEEMS A BIT QUICK WITH THE FRONT...BUT
SLOWING DOWN THE HRRR A BIT WOULD SUGGEST SCT TSRA POSSIBLE FROM
RWF TO STC EAST AFTER 20Z...BUT CONFIDENCE LOW ON THAT HAPPENING
NOW. WIND SPEEDS DO NOT PICK UP UNTIL YOU GET BEHIND THE FRONT AND
SHOULD GUST TO 20-25 KTS BEHIND THE FRONT FOR A COUPLE OF HOURS.
KMSP...TSRA STILL ON TARGET TO ARRIVE BETWEEN 1300 AND 1330Z AND
OUT AROUND 1530. EXPECT BRIEF GUSTS UP AROUND 40 MPH OUT OF THE
WEST...ALONG WITH BRIEF HEAVY DOWNPOURS. LOW CONFIDENCE ON WHAT
HAPPENS THIS AFTERNOON...BUT THERE IS THE POTENTIAL FOR MORE TSRA
BETWEEN 21Z AND 00Z BEFORE FRONT CLEARS EVERYTHING OUT AND ITS VFR
THE REST OF THE WAY.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW 10G20KTS.
THU...VFR. WINDS LGT AND VRB.
FRI...VFR. WINDS S 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1031 AM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY, AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRIER AND COOLER AIR
WILL FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
GRIDS IN GOOD SHAPE. SMALL ADJUSTMENTS MADE TO THE POPS BUT IN
GENERAL IT LOOKED GOOD. SCATTERED SHOWER MOVING INTO STEUBEN NOW
WILL INCREASE IN COVERAGE AND TSTORMS WILL JOIN THEM. SEVERE
POTENTIAL MARGINAL BUT SOME SHOWERS AND TSTORMS WILL HAVE HEAVY
RAIN. STORM MOTION ONLY SLIGHTLY BETTER THAN YESTERDAY AT 10 TO 15
MPH. TEMPS ADJUSTED UP IN THE SE WHERE SOME SUNSHINE HAS PUSHED
TEMPS INTO THE U70S ALREADY.
UPDATED AT 630 AM. JUST A FEW MINOR TWEAKS TO THE FORECAST TO
ACCOUNT FOR THE LATEST TRENDS. HAVE ADDED PATCHY FOG TO SOUTHERN
NY AND NORTHERN PA THROUGH 13Z. ALSO RADAR IS DETECTING A FEW
SPRINKLES OR LIGHT SHOWERS OVER NORTHERN STEUBEN COUNTY. THESE
SHOWERS ARE DIMINISHING AS THEY MOVE EAST AND ARE NOT EXPECTED TO
REACH AS FAR EAST AS EVEN ELMIRA OR SYRACUSE THROUGH 9 AM.
PREVIOUS DISCUSSION IS BELOW.
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
ESPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
330 AM UPDATE...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. STILL
LOOKING LIKE WE MAY SEE AT LEAST A FEW DAYS OF DRY WEATHER
STARTING FRIDAY...ESPECIALLY BASED ON THE NEW 0Z EURO. I DID
MAINTAIN OUR GOING FORECAST OF SLIGHT TO LOW CHANCE (20 TO 30%)
POPS THIS WEEKEND WITH THE GFS HINTING AT A DISTURBANCE ALOFT IN
THE NORTHEAST DURING THIS TIME. THIS ALSO MATCHES UP WITH POP
GUIDANCE FROM WPC. WITH THAT SAID BASED ON THE EURO AND SURFACE
HIGH PRESSURE BUILDING IN...THE REALITY MAY BE A DRY WEEKEND. THE
PREVIOUS AFD IS BELOW...
STAGNANT PTRN CONTS TO MAKE FOR A TRICKY XTNDD PD. LATEST
OPERATIONAL GFS RUN TRENDS TWRDS LAST NGT/S EURO WITH THU/S BRIEF
RDGG GIVING WAY TO YET ANOTHER RETROGRADING OFF SHORE TROF.
MASSIVE BERMUDA HI CONTS TO BLOCK THE EWRD PROGRESS OF NRN STREAM
WV/S KEEPING THE NORTH BOUND TROPICAL FLOW IN PLACE ALONG THE CST
NEAR TO OUR FCST AREA. FOR NOW...IT LOOKS LIKE THE MAJORITY OF THE
MOISTURE ASSOCIATED WITH CHANTAL WELL EAST OF THE AREA...BUT WITH
THE UNCERTAINTY...THIS DEEP MOISTURE WILL NEED TO BE MONITORED.
DAILY SENSIBLE WX WILL SHOW SOME IMPRMNT ALTHOUGH THE ERN AND SRN
AREA WILL CONT TO BE NEAR THE EDGE OF THE DEEP MOISTURE AND MORE
AT RISK OF TRWS...ESP LATE IN THE PD. GNRLY FLWD HPC GUID BUT
NUDGED THE DATA TWRD THE MEX AND NEARER TO THE SURROUNDING OFFICES.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...
IFR RESTRICTIONS LIKELY TO CONTINUE IN DENSE FOG AT KBGM AND KELM
THROUGH ABOUT 13Z BEFORE IMPROVEMENT TO VFR. ELSEWHERE MAINLY VFR
TODAY OVERALL. SCT SHOWERS WITH SOME THUNDER POSSIBLE ESPECIALLY
BETWEEN 18Z AND 0Z. SOME BRIEF MVFR OR IFR RESTRICTIONS DUE TO
HEAVY RAIN (VSBY) POSSIBLE. AT THIS POINT TOO UNCERTAIN TO INCLUDE
IN THE TAFS BUT AS WE GET CLOSER...SOME SHORT TERM TEMPOS MAY BE NEEDED.
.OUTLOOK...
WED THRU THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT
SHWRS AND TRWS. IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...MSE/TAC
SHORT TERM...MSE
LONG TERM...DGM/HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
817 AM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY, AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRIER AND COOLER AIR
WILL FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 630 AM. JUST A FEW MINOR TWEAKS TO THE FORECAST TO
ACCOUNT FOR THE LATEST TRENDS. HAVE ADDED PATCHY FOG TO SOUTHERN
NY AND NORTHERN PA THROUGH 13Z. ALSO RADAR IS DETECTING A FEW
SPRINKLES OR LIGHT SHOWERS OVER NORTHERN STEUBEN COUNTY. THESE
SHOWERS ARE DIMINISHING AS THEY MOVE EAST AND ARE NOT EXPECTED TO
REACH AS FAR EAST AS EVEN ELMIRA OR SYRACUSE THROUGH 9 AM.
PREVIOUS DISCUSSION IS BELOW.
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
ESPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
330 AM UPDATE...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. STILL
LOOKING LIKE WE MAY SEE AT LEAST A FEW DAYS OF DRY WEATHER
STARTING FRIDAY...ESPECIALLY BASED ON THE NEW 0Z EURO. I DID
MAINTAIN OUR GOING FORECAST OF SLIGHT TO LOW CHANCE (20 TO 30%)
POPS THIS WEEKEND WITH THE GFS HINTING AT A DISTURBANCE ALOFT IN
THE NORTHEAST DURING THIS TIME. THIS ALSO MATCHES UP WITH POP
GUIDANCE FROM WPC. WITH THAT SAID BASED ON THE EURO AND SURFACE
HIGH PRESSURE BUILDING IN...THE REALITY MAY BE A DRY WEEKEND. THE
PREVIOUS AFD IS BELOW...
STAGNANT PTRN CONTS TO MAKE FOR A TRICKY XTNDD PD. LATEST
OPERATIONAL GFS RUN TRENDS TWRDS LAST NGT/S EURO WITH THU/S BRIEF
RDGG GIVING WAY TO YET ANOTHER RETROGRADING OFF SHORE TROF.
MASSIVE BERMUDA HI CONTS TO BLOCK THE EWRD PROGRESS OF NRN STREAM
WV/S KEEPING THE NORTH BOUND TROPICAL FLOW IN PLACE ALONG THE CST
NEAR TO OUR FCST AREA. FOR NOW...IT LOOKS LIKE THE MAJORITY OF THE
MOISTURE ASSOCIATED WITH CHANTAL WELL EAST OF THE AREA...BUT WITH
THE UNCERTAINTY...THIS DEEP MOISTURE WILL NEED TO BE MONITORED.
DAILY SENSIBLE WX WILL SHOW SOME IMPRMNT ALTHOUGH THE ERN AND SRN
AREA WILL CONT TO BE NEAR THE EDGE OF THE DEEP MOISTURE AND MORE
AT RISK OF TRWS...ESP LATE IN THE PD. GNRLY FLWD HPC GUID BUT
NUDGED THE DATA TWRD THE MEX AND NEARER TO THE SURROUNDING OFFICES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...
IFR RESTRICTIONS LIKELY TO CONTINUE IN DENSE FOG AT KBGM AND KELM
THROUGH ABOUT 13Z BEFORE IMPROVEMENT TO VFR. ELSEWHERE MAINLY VFR
TODAY OVERALL. SCT SHOWERS WITH SOME THUNDER POSSIBLE ESPECIALLY
BETWEEN 18Z AND 0Z. SOME BRIEF MVFR OR IFR RESTRICTIONS DUE TO
HEAVY RAIN (VSBY) POSSIBLE. AT THIS POINT TOO UNCERTAIN TO INCLUDE
IN THE TAFS BUT AS WE GET CLOSER...SOME SHORT TERM TEMPOS MAY BE NEEDED.
.OUTLOOK...
WED THRU THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT
SHWRS AND TRWS. IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...DGM/HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
701 AM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRYER AIR WILL
FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 630 AM. JUST A FEW MINOR TWEAKS TO THE FORECAST TO
ACCOUNT FOR THE LATEST TRENDS. HAVE ADDED PATCHY FOG TO SOUTHERN
NY AND NORTHERN PA THROUGH 13Z. ALSO RADAR IS DETECTING A FEW
SPRINKLES OR LIGHT SHOWERS OVER NORTHERN STEUBEN COUNTY. THESE
SHOWERS ARE DIMINISHING AS THEY MOVE EAST AND ARE NOT EXPECTED TO
REACH AS FAR EAST AS EVEN ELMIRA OR SYRACUSE THROUGH 9 AM.
PREVIOUS DISCUSSION IS BELOW.
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
ESPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
330 AM UPDATE...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. STILL
LOOKING LIKE WE MAY SEE AT LEAST A FEW DAYS OF DRY WEATHER
STARTING FRIDAY...ESPECIALLY BASED ON THE NEW 0Z EURO. I DID
MAINTAIN OUR GOING FORECAST OF SLIGHT TO LOW CHANCE (20 TO 30%)
POPS THIS WEEKEND WITH THE GFS HINTING AT A DISTURBANCE ALOFT IN
THE NORTHEAST DURING THIS TIME. THIS ALSO MATCHES UP WITH POP
GUIDANCE FROM WPC. WITH THAT SAID BASED ON THE EURO AND SURFACE
HIGH PRESSURE BUILDING IN...THE REALITY MAY BE A DRY WEEKEND. THE
PREVIOUS AFD IS BELOW...
STAGNANT PTRN CONTS TO MAKE FOR A TRICKY XTNDD PD. LATEST
OPERATIONAL GFS RUN TRENDS TWRDS LAST NGT/S EURO WITH THU/S BRIEF
RDGG GIVING WAY TO YET ANOTHER RETROGRADING OFF SHORE TROF.
MASSIVE BERMUDA HI CONTS TO BLOCK THE EWRD PROGRESS OF NRN STREAM
WV/S KEEPING THE NORTH BOUND TROPICAL FLOW IN PLACE ALONG THE CST
NEAR TO OUR FCST AREA. FOR NOW...IT LOOKS LIKE THE MAJORITY OF THE
MOISTURE ASSOCIATED WITH CHANTAL WELL EAST OF THE AREA...BUT WITH
THE UNCERTAINTY...THIS DEEP MOISTURE WILL NEED TO BE MONITORED.
DAILY SENSIBLE WX WILL SHOW SOME IMPRMNT ALTHOUGH THE ERN AND SRN
AREA WILL CONT TO BE NEAR THE EDGE OF THE DEEP MOISTURE AND MORE
AT RISK OF TRWS...ESP LATE IN THE PD. GNRLY FLWD HPC GUID BUT
NUDGED THE DATA TWRD THE MEX AND NEARER TO THE SURROUNDING OFFICES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
12Z UPDATE...
IFR RESTRICTIONS LIKELY TO CONTINUE IN DENSE FOG AT KBGM AND KELM
THROUGH ABOUT 13Z BEFORE IMPROVEMENT TO VFR. ELSEWHERE MAINLY VFR
TODAY OVERALL. SCT SHOWERS WITH SOME THUNDER POSSIBLE ESPECIALLY
BETWEEN 18Z AND 0Z. SOME BRIEF MVFR OR IFR RESTRICTIONS DUE TO
HEAVY RAIN (VSBY) POSSIBLE. AT THIS POINT TOO UNCERTAIN TO INCLUDE
IN THE TAFS BUT AS WE GET CLOSER...SOME SHORT TERM TEMPOS MAY BE NEEDED.
.OUTLOOK...
WED THRU THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT
SHWRS AND TRWS. IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...DGM/HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
633 AM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRYER AIR WILL
FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 630 AM. JUST A FEW MINOR TWEAKS TO THE FORECAST TO
ACCOUNT FOR THE LATEST TRENDS. HAVE ADDED PATCHY FOG TO SOUTHERN
NY AND NORTHERN PA THROUGH 13Z. ALSO RADAR IS DETECTING A FEW
SPRINKLES OR LIGHT SHOWERS OVER NORTHERN STEUBEN COUNTY. THESE
SHOWERS ARE DIMINISHING AS THEY MOVE EAST AND ARE NOT EXPECTED TO
REACH AS FAR EAST AS EVEN ELMIRA OR SYRACUSE THROUGH 9 AM.
PREVIOUS DISCUSSION IS BELOW.
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
EXPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
330 AM UPDATE...NO MAJOR CHANGES TO THE PREVIOUS FORECAST. STILL
LOOKING LIKE WE MAY SEE AT LEAST A FEW DAYS OF DRY WEATHER
STARTING FRIDAY...ESPECIALLY BASED ON THE NEW 0Z EURO. I DID
MAINTAIN OUR GOING FORECAST OF SLIGHT TO LOW CHANCE (20 TO 30%)
POPS THIS WEEKEND WITH THE GFS HINTING AT A DISTURBANCE ALOFT IN
THE NORTHEAST DURING THIS TIME. THIS ALSO MATCHES UP WITH POP
GUIDANCE FROM WPC. WITH THAT SAID BASED ON THE EURO AND SURFACE
HIGH PRESSURE BUILDING IN...THE REALITY MAY BE A DRY WEEKEND. THE
PREVIOUS AFD IS BELOW...
STAGNANT PTRN CONTS TO MAKE FOR A TRICKY XTNDD PD. LATEST
OPERATIONAL GFS RUN TRENDS TWRDS LAST NGT/S EURO WITH THU/S BRIEF
RDGG GIVING WAY TO YET ANOTHER RETROGRADING OFF SHORE TROF.
MASSIVE BERMUDA HI CONTS TO BLOCK THE EWRD PROGRESS OF NRN STREAM
WV/S KEEPING THE NORTH BOUND TROPICAL FLOW IN PLACE ALONG THE CST
NEAR TO OUR FCST AREA. FOR NOW...IT LOOKS LIKE THE MAJORITY OF THE
MOISTURE ASSOCIATED WITH CHANTAL WELL EAST OF THE AREA...BUT WITH
THE UNCERTAINTY...THIS DEEP MOISTURE WILL NEED TO BE MONITORED.
DAILY SENSIBLE WX WILL SHOW SOME IMPRMNT ALTHOUGH THE ERN AND SRN
AREA WILL CONT TO BE NEAR THE EDGE OF THE DEEP MOISTURE AND MORE
AT RISK OF TRWS...ESP LATE IN THE PD. GNRLY FLWD HPC GUID BUT
NUDGED THE DATA TWRD THE MEX AND NEARER TO THE SURROUNDING OFFICES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
PERIODS OF FOG...PRODUCING IFR RESTRICTIONS ARE POSSIBLE THROUGH
DAYBREAK ESPECIALLY AT KELM/KITH/KBGM WITH THESE SITES SEEING THE
MOST RAIN MONDAY AFTERNOON. A COMPLICATING FACTOR WILL BE AN AREA
OF HIGH CLOUDS NOW OVER WESTERN NY THAT WILL SLIDE EAST DURING
THIS PERIOD. WITH IFR RESTRICTIONS ALREADY AT ALL THREE SITES
BEING TEMPERED BY THIS HIGH CLOUD THREAT...ELECTED TO MAINLY GO
WITH TEMPO GROUPS FOR IFR GIVEN THE HIGH VARIABILITY EXPECTED
THROUGHOUT THE NIGHT. KELM STANDS THE BEST CHANCE FOR GOING DOWN
AND STAYING DOWN. ELSEWHERE VFR IS EXPECTED.
ANY FOG SHOULD BURN OFF BETWEEN 12Z AND 13Z. AFTER THAT A
DISTURBANCE MOVING THROUGH LATER IN THE DAY WILL BRING SCT.
SHOWERS TO THE TERMINALS MAINLY DURING THE PEAK HEATING (18Z -
0Z). WHILE THUNDER IS POSSIBLE I DID NOT INCLUDE IN THE TAFS JUST
YET GIVEN THE EXPECTED SCT. COVERAGE.
.OUTLOOK...
WED THRU THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT
SHWRS AND TRWS. IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...MSE
SHORT TERM...MSE
LONG TERM...DGM/HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK UPPER LEVEL LOW PRESSURE TROUGH WILL HOLD OVER THE EASTERN
U.S. THROUGH WEDNESDAY. A STRONGER UPPER LEVEL TROUGH AND ASSOCIATED
SURFACE COLD FRONT WILL APPROACH THE AREA FROM THE NORTHEAST LATE
WEDNESDAY... AND SWING THROUGH THE REGION THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM TUESDAY...
REST OF TODAY THROUGH TONIGHT: QUITE A BIT OF STRATUS (ABOUT 500 FT
THICK ACCORDING TO PILOT REPORTS) IS HOLDING OVER THE AREA...
PARTICULARY NRN/WRN AREAS. WATER VAPOR IMAGERY SHOWS A SUBTLE
VORTICITY MAX DROPPING THROUGH CENTRAL VA INTO NRN NC... ON THE
HEELS OF ANOTHER WAVE NOW SUPPORTING SLOW-MOVING THUNDERSTORM
CLUSTERS NEAR THE COAST. THE LATEST HRRR RUNS SHOW SCATTERED TO
NUMEROUS STORMS DEVELOPING OVER THE SRN/ERN PORTIONS OF THE FORECAST
AREA... PERHAPS A RESPONSE TO BOTH GREATER HEATING IN THIS AREA THIS
MORNING AND THE PASSAGE OF THIS WEAK WAVE. CURRENT FORECAST... WITH
MINOR ADJUSTMENTS IN TIMING AND AREA... HINTS AT THIS SCENARIO AND
LOOKS VERY REASONABLE GIVEN THE SHORT TERM TRENDS. CINH IS QUICKLY
ERODING WITH MLCAPE ALREADY AT 1500 J/KG... BUT WITH LOW DEEP-LAYER
BULK SHEAR AND MEANDERING MOVEMENT... STORMS SHOULD STAY BELOW
SEVERE LIMITS... BUT THE RISK OF LOCALLY HEAVY DOWNPOURS WILL
PERSIST. LOW LEVEL THICKNESSES FAVOR HIGHS IN THE UPPER 80S... IN
LINE WITH LATEST STATISTICAL GUIDANCE AND EXISTING FORECAST...
FACTORING IN VARIABLY CLOUDY SKIES. -GIH
THOUGH COVERAGE AND INTENSITY SHOULD DIMINISH WITH NOCTURNAL
COOLING...THE VERY MOIST AND WEAKLY CONDITIONALLY UNSTABLE AIR MASS
OVERNIGHT WILL LIKELY SUPPORT A FEW SHOWERS. LOWS IN THE LOWER 70S.
-MWS
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 AM TUESDAY...
WEDNESDAY AND WEDNESDAY NIGHT: PERSISTENCE OVERALL...WITH CONTINUED
BERMUDA HIGH PRESSURE EXTENDING WESTWARD INTO THE CAROLINAS...
BENEATH TROUGHING/CYCLONIC FLOW IN THE MID LEVELS. THIS
PATTERN...AMIDST A VERY MOIST AND UNCAPPED BOUNDARY LAYER...SHOULD
AGAIN PRODUCE SCATTERED SHOWERS AND STORMS MAXIMIZED WITH DIURNAL
HEATING. IN ADDITION...GULF MOISTURE...WHICH WILL HAVE BEEN
PREVIOUSLY LIMITED OWING TO RIDGING OVER THE GOM AND GULF COAST
STATES...WILL HAVE CIRCUMVENTED THE RIDGE AND ARRIVE IN
STRENGTHENING H85 WESTERLY FLOW LATE WED AND ESPECIALLY WED NIGHT.
THIS REGIME...AS WELL AS INCREASING HEIGHT FALLS ALOFT DOWNSTREAM OF
A POWERFUL TROUGH AMPLIFYING THROUGH THE GREAT LAKES...MAY SUPPORT
ADDITIONAL CONVECTION OVERNIGHT...MAINLY OVER THE WESTERN PIEDMONT
WHERE THE EFFECTS OF THE MOISTURE TRANSPORT/ISENTROPIC UPGLIDE WILL
OCCUR FIRST. PERSISTENCE TEMPS IN THE UPPER 80S TO AROUND 90...AND
LOWER 70S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 225 AM TUESDAY...
THURSDAY THROUGH FRIDAY IS EXPECTED TO BE A WET PERIOD ONCE AGAIN.
THE APPROACH OF ANOTHER MID/UPPER TROUGH FROM THE NW COMBINED WITH
THE SURFACE COLD FRONT SETTLING INTO LOWER TO MID 70S DEW POINTS
WILL SET THE STAGE FOR YET ANOTHER COUPLE OF DAYS WITH WIDESPREAD
CONVECTIVE RAINS. THE HIGHEST POP IS EXPECTED ON THURSDAY OVER THE
PIEDMONT INTO PORTIONS OF THE COASTAL PLAIN AND SANDHILLS BY LATE
AFTERNOON/EVENING. CONVECTIVE DEVELOPMENT THURSDAY SHOULD BE AIDED
BY THE LEE TROUGH AND DIFFERENTIAL HEATING ALONG THE MOUNTAINS. THE
FORMER SHOULD RESULT IN GOOD LOW LEVEL CONVERGENCE WITH PRECIPITABLE
WATER VALUES INCREASING TO BETWEEN 1.8 AND 2 INCHES FAVORING HEAVY
RAINERS SPREADING OFF THE BLUE RIDGE OUT OVER THE PIEDMONT BY EARLY
AFTERNOON. ADDITIONAL DEVELOPMENT SHOULD OCCUR ALONG THE LEE TROUGH
AND NUMEROUS CONVECTIVE OUTFLOWS DURING THE MID TO LATE AFTERNOON
EASTWARD THROUGH THE PIEDMONT AND COASTAL PLAIN. SINCE CATEGORICAL
POP ARE IN PLACE... NO NEED FOR ADJUSTMENTS. QPF OF 1 TO LOCALLY 2
INCHES EXPECTED 12Z THU THROUGH 12 FRI.
THE HEAVY RAIN THREAT WITH DEEP CONVECTION SHOULD SHIFT SLOWLY SE
THROUGH THE REGION REACHING THE SANDHILLS AND COASTAL PLAIN THURSDAY
NIGHT... WHILE LINGERING IN THE PIEDMONT. THEN FRIDAY... NUMEROUS
SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP... ALONG AND AHEAD OF
THE LEFT-OVER CONVECTIVE BOUNDARIES/COLD FRONT. IT APPEARS THAT THE
NW PIEDMONT SHOULD HAVE THE LOWER POP (BUT STILL IN THE LIKELY RANGE
FRIDAY). TO THE EAST AND SOUTH... THROUGH MUCH OF CENTRAL AND
EASTERN NC... NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED AS THE
COLD FRONT SLOWS TO A CRAWL... FOCUSING HIGH PW`S OF 2+ INCHES...
AND LOW LEVEL CONVERGENCE. QPF OF 1.5 TO 2 INCHES LOOKS A GOOD
BET... WITH LOCALLY HIGHER TOTALS. THIS WOULD GIVE QPF 2 DAY TOTALS
OF 2 TO 4 INCHES... NOT WHAT AGRICULTURAL INTERESTS NEED AT THIS
POINT.
FRIDAY NIGHT AND SATURDAY... THE COLD FRONT SHOULD STALL OVER THE
COASTAL PLAIN... WHERE THE HIGHEST POP WILL RESIDE. LOCALLY HEAVY
RAIN THREAT WILL CONTINUE. NUMEROUS SHOWERS AND THUNDERSTORMS SHOULD
BECOME MORE SCATTERED BY SATURDAY ACROSS THE NW PIEDMONT (AWAY FROM
THE STALLED BOUNDARY TO THE SE). LOWS 70-73. HIGHS LOWER TO MID 80S.
SUNDAY AND MONDAY... THE FOCUS TURNS TO THE EVOLUTION OF TS CHANTAL.
IT APPEARS THAT THE BEST FORECAST FOR OUR REGION WOULD BE TO FOLLOW
THE ENSEMBLE MEANS AND MODEL TRENDS. THE ANTECEDENT VERY WET
CONDITIONS OVER OUR REGION CERTAINLY WOULD BE PROBLEMATIC TO SAY THE
LEAST SHOULD CHANTAL BECOME AN ISSUE FOR NC.
HOWEVER... THE ENSEMBLES GENERALLY TURN WHAT IS LEFT OF THIS SYSTEM
WESTWARD AS HEIGHTS ARE FORECAST TO RISE ALONG THE EAST COAST FROM
BUILDING WESTERN ATLANTIC RIDGING BY SUNDAY AND MONDAY. AS OF THIS
FORECAST... IT APPEARS THAT MID/UPPER RIDGING OVER THE WESTERN
ATLANTIC MAY BUILD WESTWARD INTO EASTERN NC ENOUGH TO STEER THIS
SYSTEM WESTWARD (GULF COAST) BY SUNDAY AND MONDAY. THIS WOULD ALLOW
THE NUMEROUS SHOWERS AND STORMS TO BECOME SCATTERED... MAINLY
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY FOR OUR
REGION. HIGHS WOULD ALSO GO UP TO NEAR NORMAL BY THEN AS WELL. LOWS
70-73. HIGHS 85-88.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 745 AM TUESDAY...
CONTINUED VERY HUMID SOUTHERLY FLOW AROUND BERMUDA HIGH PRESSURE
WILL MAINTAIN A FAMILIAR...PERSISTENT PATTERN. THAT IS...LIFR-IFR
CEILINGS AND VFR-MVFR VISIBILITY RESTRICTIONS TRANSITIONING THROUGH
MVFR RANGE TO VFR BETWEEN 13-15Z...WITH MOSTLY AFTERNOON-EVENING
THUNDERSTORMS...MOST LIKELY TODAY AT KFAY/KRWI/KRDU. LIFR-IFR
CEILINGS AND MVFR VISIBILITY RESTRICTIONS WILL THEN REDEVELOP IN THE
VERY HUMID REGIME LATE TONIGHT.
OUTLOOK...
INCREASED SHOWER AND STORM COVERAGE...AND MORE PROLONGED
MVFR CONDITIONS THAN PREVIOUS DAYS - INTO EARLY AFTERNOON - WILL
DEVELOP BY FRI-SAT...AS A STRONG UPPER LEVEL TROUGH AND SURFACE COLD
FRONT MOVE INTO OUR REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/MWS
SHORT TERM...MWS
LONG TERM...BADGETT
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1033 AM EDT TUE JUL 9 2013
.SYNOPSIS...
THE WEATHER WILL REMAIN UNSETTLED ACROSS THE LOWER GREAT LAKES AND
OHIO VALLEY TODAY AND TONIGHT AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE AREA ON WEDNESDAY. THURSDAY AND FRIDAY HIGH PRESSURE
AND DRY STABLE AIR WILL BUILD IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NUMEROUS FLOOD WARNINGS REMAIN IN EFFECT FROM 2-4 INCHES OF HEAVY
RAIN THAT FELL OVERNIGHT. FORTUNATELY DRIER AIR ALOFT IS
OVERSPREADING THE AREA AS SEEN ON THE 12Z DTX SOUNDING WITH LARGER
SCALE SUBSIDENCE IN THE WAKE OF LAST NIGHTS SHORTWAVE. EXPECT
SEVERAL HOURS OF DRY CONDITIONS THROUGH MID AFTERNOON WITH
INSTABILITY STARTING TO CREEP BACK UP FROM THE SOUTH LATE IN THE
DAY AS DEWPOINTS REMAIN IN THE LOW 70S. WE COULD START TO SEE SOME
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP IN OUR SOUTHWESTERN
COUNTIES THAT RECEIVED THE HEAVY RAIN OVERNIGHT BY LATE AFTERNOON.
WE ARE ALSO KEEPING AN EYE ON THE CONVECTION MOVING INTO WESTERN
ILLINOIS AS IT APPROACHES LATER TODAY FOR BOUNDARIES THAT MAY HELP KICK
OFF SHOWERS AND THUNDERSTORMS ALONG THE STALLED WARM FRONTAL
BOUNDARY ACROSS INDIANA/WESTERN OHIO. OTHERWISE ANOTHER ROUND OF RAIN
IS STILL EXPECTED OVERNIGHT INTO TOMORROW AND THE THREAT FOR
FLOODING CONTINUES.
ORIGINAL...FOR THE MORNING EXPECT THE TREND IN PLACE TO SLOWLY
CONTINUE WITH PRECIP MOVING EAST/SOUTHEAST OF THE AREA AND DRIER
AIR MOVING IN FROM THE NORTHWEST. SHOULD EVENTUALLY SEE SOME SS
TODAY HOWEVER HRRR DOES SHOW SCATTERED CONVECTION REDEVELOPING IN
THE MOIST UNSTABLE AIR STILL IN PLACE ACROSS THE AREA LATER THIS
AFTERNOON. BEST CHANCES WOULD BE WEST/SWRN COUNTIES. WILL BRING
CHANCE POPS BACK TO THE SRN/SWRN COUNTIES WITH SLIGHT CHANCE POPS
ON THE NORTH SIDE OF THAT. HIGHS NEAR GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FOLLOWED MIX OF HPC/NAM AND SREF GUIDANCE FOR THE SHORT TERM. COLD
FRONT IS ON THE WAY FOR WEDNESDAY AND TONIGHT AHEAD OF THE FRONT MODELS
SHOWED A COUPLE SHORT WAVES MOVING ACROSS THE REGION. EXPECTING
SHOWERS/THUNDERSTORMS MOVING IN FROM THE WEST LATE EVENING OR
EARLY IN THE NIGHT AND PERSISTING THROUGH MUCH OF WEDNESDAY. WOULD
ANTICIPATE THE NEED FOR A FLOOD WATCH BUT GIVEN THE CURRENT
HEADLINE WILL WAIT FOR DAY SHIFT TO REEVALUATE. GIVEN HPC QPF
VALUES INCREASED MAV GUIDANCE POPS AGREEING MORE WITH THE SREF
CATEGORICAL GUIDANCE TONIGHT AND WEDNESDAY. THURSDAY AND FRIDAY
SUN AND DRY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS HAVE BEEN SLOWLY TRENDING TO A DRIER WEEKEND WITH THE CENTRAL
U.S. RIDGE TRYING TO NOSE INTO THE LOWER GREAT LAKES AND THE TROUGH
SHIFTING TO THE EAST COAST. THIS WILL PUT IS IN THE MIDDLE AND WILL
KEEP THE DRY WEEKEND FORECAST AND THE LOW PRECIP CHANCES FOR MONDAY
WITH AN INCREASE IN MOISTURE. WILL PUT TEMPS IN BETWEEN GFS AND
ECMWF GUIDANCE AS A COMPROMISE SEEMS BEST RIGHT NOW. THAT WILL GIVE
US SEASONABLE TEMPS FOR THE WEEKEND IN THE LOWER TO MID 80S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
RELATIVE LULL TODAY IN SHOWERS/TS ALTHOUGH A FEW MIGHT START TO
POP UP AGAIN LATE THIS AFTERNOON FOR FDY/MFD/CAK. SOME MORNING BR
TO START ALONG WITH SOME MVFR CIGS. EXPECTING IMPROVEMENT TO VFR
FOR MIDDAY AND INTO THE AFTERNOON. WINDS WILL SHIFT TO THE WEST
TODAY AND BRING IN SOMEWHAT DRIER AIR. TONIGHT THOUGH SHOWERS/TS
TO BREAK OUT ONCE AGAIN AS FLOW COMES BACK AROUND TO THE SSW. A
COLD FRONT WILL APPROACH FOR WEDNESDAY SO MORE WIDESPREAD SHRA/TS
TOWARD DAWN AND BEYOND. SOME OF THOSE COULD BE STRONG TO SEVERE.
HEAVY RAIN AND IFR CONDITIONS WITHIN TS.
.OUTLOOK...NON-VFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH
WEDNESDAY NIGHT.
&&
.MARINE...
A RELATIVE LULL IN THE THUNDERSTORM CHANCES FOR TODAY. SOUTH-SW FLOW
WILL CONTINUE WITH A NEARLY STATIONARY BOUNDARY JUST NORTH OF THE
LAKE. LOW PRESSURE WILL TRACK ACROSS THE NORTHERN LAKES WEDNESDAY
AND TAKE A COLD FRONT ACROSS LAKE ERIE WITH ANOTHER ROUND OF
THUNDERSTORMS...SOME OF WHICH WILL BE ON THE STRONG SIDE. WINDS MAY
PICK UP ENOUGH TO NEED A SMALL CRAFT ADV WITH THIS SYSTEM. SOME CHOP
POSSIBLE WEDNESDAY AHEAD OF THE FRONT FOR THE EASTERN NEARSHORE WITH
SW FLOW ALONG THE LENGTH OF THE LAKE. BETTER CHANCES FOR SMALL CRAFT
ADV CONDITIONS IN THE NORTHWEST FLOW AFTER THE FRONT. THE WEATHER
SETTLES DOWN THURSDAY THROUGH SATURDAY WITH HIGH PRESSURE OVER THE
CENTRAL GREAT LAKES. WILL HAVE A NORTHERLY FLOW THAT WILL BECOME ENE
BY SATURDAY AS THE HIGH SHIFTS EAST...REMAINING NORTH OF LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...KEC/TK
SHORT TERM...TK/KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
751 AM EDT TUE JUL 9 2013
.SYNOPSIS...
THE WEATHER WILL REMAIN UNSETTLED ACROSS THE LOWER GREAT LAKES AND
OHIO VALLEY TODAY AND TONIGHT AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE AREA ON WEDNESDAY. THURSDAY AND FRIDAY HIGH PRESSURE
AND DRY STABLE AIR WILL BUILD IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...CANCELLED THE FLASH FLOOD WATCH. ALTHOUGH FLOODING IS
ONGOING...WILL HANDLY WITH CURRENT WARNINGS. THREAT OF ADDITIONAL
FLOOD PRODUCING RAIN HAS DIMINISHED FOOR TODAY.
ORIGINAL...MADE ADJUSTMENT TO THE FLOOD WATCH TRIMMING THE
NORTHERN COUNTIES BUT EXTENDING IT A FEW HOURS INTO THE MORNING
FOR THE REMAINING SOUTHERN COUNTIES. RADAR SHOWS THE HEAVY RAIN
MOVING SLOWLY EAST HOWEVER MORE SHOWERS HAVE DEVELOPED ON THE WEST
SIDE OF THE MAIN CONVECTION ACROSS PORTIONS OF CRAWFORD/WYANDOT
AND MARION COUNTIES. RAIN STILL OCCURRING ACROSS THE CENTRAL
LAKESHORE BUT IS NOT INTENSE ENOUGH TO CAUSE FLOODING. FOR THE
MORNING EXPECT THE TREND IN PLACE TO SLOWLY CONTINUE WITH PRECIP
MOVING EAST/SOUTHEAST OF THE AREA AND DRIER AIR MOVING IN FROM THE
NORTHWEST. SHOULD EVENTUALLY SEE SOME SS TODAY HOWEVER HRRR DOES
SHOW SCATTERED CONVECTION REDEVELOPING IN THE MOIST UNSTABLE AIR
STILL IN PLACE ACROSS THE AREA LATER THIS AFTERNOON. BEST CHANCES
WOULD BE WEST/SWRN COUNTIES. WILL BRING CHANCE POPS BACK TO THE
SRN/SWRN COUNTIES WITH SLIGHT CHANCE POPS ON THE NORTH SIDE OF
THAT. HIGHS NEAR GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FOLLOWED MIX OF HPC/NAM AND SREF GUIDANCE FOR THE SHORT TERM. COLD
FRONT IS ON THE WAY FOR WEDNESDAY AND TONIGHT AHEAD OF THE FRONT MODELS
SHOWED A COUPLE SHORT WAVES MOVING ACROSS THE REGION. EXPECTING
SHOWERS/THUNDERSTORMS MOVING IN FROM THE WEST LATE EVENING OR
EARLY IN THE NIGHT AND PERSISTING THROUGH MUCH OF WEDNESDAY. WOULD
ANTICIPATE THE NEED FOR A FLOOD WATCH BUT GIVEN THE CURRENT
HEADLINE WILL WAIT FOR DAY SHIFT TO REEVALUATE. GIVEN HPC QPF
VALUES INCREASED MAV GUIDANCE POPS AGREEING MORE WITH THE SREF
CATEGORICAL GUIDANCE TONIGHT AND WEDNESDAY. THURSDAY AND FRIDAY
SUN AND DRY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS HAVE BEEN SLOWLY TRENDING TO A DRIER WEEKEND WITH THE CENTRAL
U.S. RIDGE TRYING TO NOSE INTO THE LOWER GREAT LAKES AND THE TROUGH
SHIFTING TO THE EAST COAST. THIS WILL PUT IS IN THE MIDDLE AND WILL
KEEP THE DRY WEEKEND FORECAST AND THE LOW PRECIP CHANCES FOR MONDAY
WITH AN INCREASE IN MOISTURE. WILL PUT TEMPS IN BETWEEN GFS AND
ECMWF GUIDANCE AS A COMPROMISE SEEMS BEST RIGHT NOW. THAT WILL GIVE
US SEASONABLE TEMPS FOR THE WEEKEND IN THE LOWER TO MID 80S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
RELATIVE LULL TODAY IN SHOWERS/TS ALTHOUGH A FEW MIGHT START TO
POP UP AGAIN LATE THIS AFTERNOON FOR FDY/MFD/CAK. SOME MORNING BR
TO START ALONG WITH SOME MVFR CIGS. EXPECTING IMPROVEMENT TO VFR
FOR MIDDAY AND INTO THE AFTERNOON. WINDS WILL SHIFT TO THE WEST
TODAY AND BRING IN SOMEWHAT DRIER AIR. TONIGHT THOUGH SHOWERS/TS
TO BREAK OUT ONCE AGAIN AS FLOW COMES BACK AROUND TO THE SSW. A
COLD FRONT WILL APPROACH FOR WEDNESDAY SO MORE WIDESPREAD SHRA/TS
TOWARD DAWN AND BEYOND. SOME OF THOSE COULD BE STRONG TO SEVERE.
HEAVY RAIN AND IFR CONDITIONS WITHIN TS.
.OUTLOOK...NON-VFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH
WEDNESDAY NIGHT.
&&
.MARINE...
A RELATIVE LULL IN THE THUNDERSTORM CHANCES FOR TODAY. SOUTH-SW FLOW
WILL CONTINUE WITH A NEARLY STATIONARY BOUNDARY JUST NORTH OF THE
LAKE. LOW PRESSURE WILL TRACK ACROSS THE NORTHERN LAKES WEDNESDAY
AND TAKE A COLD FRONT ACROSS LAKE ERIE WITH ANOTHER ROUND OF
THUNDERSTORMS...SOME OF WHICH WILL BE ON THE STRONG SIDE. WINDS MAY
PICK UP ENOUGH TO NEED A SMALL CRAFT ADV WITH THIS SYSTEM. SOME CHOP
POSSIBLE WEDNESDAY AHEAD OF THE FRONT FOR THE EASTERN NEARSHORE WITH
SW FLOW ALONG THE LENGTH OF THE LAKE. BETTER CHANCES FOR SMALL CRAFT
ADV CONDITIONS IN THE NORTHWEST FLOW AFTER THE FRONT. THE WEATHER
SETTLES DOWN THURSDAY THROUGH SATURDAY WITH HIGH PRESSURE OVER THE
CENTRAL GREAT LAKES. WILL HAVE A NORTHERLY FLOW THAT WILL BECOME ENE
BY SATURDAY AS THE HIGH SHIFTS EAST...REMAINING NORTH OF LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK/KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
741 AM EDT TUE JUL 9 2013
.SYNOPSIS...
THE WEATHER WILL REMAIN UNSETTLED ACROSS THE LOWER GREAT LAKES AND
OHIO VALLEY TODAY AND TONIGHT AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE AREA ON WEDNESDAY. THURSDAY AND FRIDAY HIGH PRESSURE
AND DRY STABLE AIR WILL BUILD IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE ADJUSTMENT TO SKY GRIDS TODAY THROUGH THE NEXT
COUPLE DAYS. ALSO ADJUSTED POPS AND WX BASED ON CURRENT RADAR.
ORIGINAL...MADE ADJUSTMENT TO THE FLOOD WATCH TRIMMING THE
NORTHERN COUNTIES BUT EXTENDING IT A FEW HOURS INTO THE MORNING
FOR THE REMAINING SOUTHERN COUNTIES. RADAR SHOWS THE HEAVY RAIN
MOVING SLOWLY EAST HOWEVER MORE SHOWERS HAVE DEVELOPED ON THE WEST
SIDE OF THE MAIN CONVECTION ACROSS PORTIONS OF CRAWFORD/WYANDOT
AND MARION COUNTIES. RAIN STILL OCCURRING ACROSS THE CENTRAL
LAKESHORE BUT IS NOT INTENSE ENOUGH TO CAUSE FLOODING. FOR THE
MORNING EXPECT THE TREND IN PLACE TO SLOWLY CONTINUE WITH PRECIP
MOVING EAST/SOUTHEAST OF THE AREA AND DRIER AIR MOVING IN FROM THE
NORTHWEST. SHOULD EVENTUALLY SEE SOME SS TODAY HOWEVER HRRR DOES
SHOW SCATTERED CONVECTION REDEVELOPING IN THE MOIST UNSTABLE AIR
STILL IN PLACE ACROSS THE AREA LATER THIS AFTERNOON. BEST CHANCES
WOULD BE WEST/SWRN COUNTIES. WILL BRING CHANCE POPS BACK TO THE
SRN/SWRN COUNTIES WITH SLIGHT CHANCE POPS ON THE NORTH SIDE OF
THAT. HIGHS NEAR GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FOLLOWED MIX OF HPC/NAM AND SREF GUIDANCE FOR THE SHORT TERM. COLD
FRONT IS ON THE WAY FOR WEDNESDAY AND TONIGHT AHEAD OF THE FRONT MODELS
SHOWED A COUPLE SHORT WAVES MOVING ACROSS THE REGION. EXPECTING
SHOWERS/THUNDERSTORMS MOVING IN FROM THE WEST LATE EVENING OR
EARLY IN THE NIGHT AND PERSISTING THROUGH MUCH OF WEDNESDAY. WOULD
ANTICIPATE THE NEED FOR A FLOOD WATCH BUT GIVEN THE CURRENT
HEADLINE WILL WAIT FOR DAY SHIFT TO REEVALUATE. GIVEN HPC QPF
VALUES INCREASED MAV GUIDANCE POPS AGREEING MORE WITH THE SREF
CATEGORICAL GUIDANCE TONIGHT AND WEDNESDAY. THURSDAY AND FRIDAY
SUN AND DRY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS HAVE BEEN SLOWLY TRENDING TO A DRIER WEEKEND WITH THE CENTRAL
U.S. RIDGE TRYING TO NOSE INTO THE LOWER GREAT LAKES AND THE TROUGH
SHIFTING TO THE EAST COAST. THIS WILL PUT IS IN THE MIDDLE AND WILL
KEEP THE DRY WEEKEND FORECAST AND THE LOW PRECIP CHANCES FOR MONDAY
WITH AN INCREASE IN MOISTURE. WILL PUT TEMPS IN BETWEEN GFS AND
ECMWF GUIDANCE AS A COMPROMISE SEEMS BEST RIGHT NOW. THAT WILL GIVE
US SEASONABLE TEMPS FOR THE WEEKEND IN THE LOWER TO MID 80S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
RELATIVE LULL TODAY IN SHOWERS/TS ALTHOUGH A FEW MIGHT START TO
POP UP AGAIN LATE THIS AFTERNOON FOR FDY/MFD/CAK. SOME MORNING BR
TO START ALONG WITH SOME MVFR CIGS. EXPECTING IMPROVEMENT TO VFR
FOR MIDDAY AND INTO THE AFTERNOON. WINDS WILL SHIFT TO THE WEST
TODAY AND BRING IN SOMEWHAT DRIER AIR. TONIGHT THOUGH SHOWERS/TS
TO BREAK OUT ONCE AGAIN AS FLOW COMES BACK AROUND TO THE SSW. A
COLD FRONT WILL APPROACH FOR WEDNESDAY SO MORE WIDESPREAD SHRA/TS
TOWARD DAWN AND BEYOND. SOME OF THOSE COULD BE STRONG TO SEVERE.
HEAVY RAIN AND IFR CONDITIONS WITHIN TS.
.OUTLOOK...NON-VFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH
WEDNESDAY NIGHT.
&&
.MARINE...
A RELATIVE LULL IN THE THUNDERSTORM CHANCES FOR TODAY. SOUTH-SW FLOW
WILL CONTINUE WITH A NEARLY STATIONARY BOUNDARY JUST NORTH OF THE
LAKE. LOW PRESSURE WILL TRACK ACROSS THE NORTHERN LAKES WEDNESDAY
AND TAKE A COLD FRONT ACROSS LAKE ERIE WITH ANOTHER ROUND OF
THUNDERSTORMS...SOME OF WHICH WILL BE ON THE STRONG SIDE. WINDS MAY
PICK UP ENOUGH TO NEED A SMALL CRAFT ADV WITH THIS SYSTEM. SOME CHOP
POSSIBLE WEDNESDAY AHEAD OF THE FRONT FOR THE EASTERN NEARSHORE WITH
SW FLOW ALONG THE LENGTH OF THE LAKE. BETTER CHANCES FOR SMALL CRAFT
ADV CONDITIONS IN THE NORTHWEST FLOW AFTER THE FRONT. THE WEATHER
SETTLES DOWN THURSDAY THROUGH SATURDAY WITH HIGH PRESSURE OVER THE
CENTRAL GREAT LAKES. WILL HAVE A NORTHERLY FLOW THAT WILL BECOME ENE
BY SATURDAY AS THE HIGH SHIFTS EAST...REMAINING NORTH OF LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 9 AM EDT THIS MORNING FOR OHZ027>030-
036-037-047.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK/KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
646 AM EDT TUE JUL 9 2013
.SYNOPSIS...
THE WEATHER WILL REMAIN UNSETTLED ACROSS THE LOWER GREAT LAKES AND
OHIO VALLEY TODAY AND TONIGHT AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE AREA ON WEDNESDAY. THURSDAY AND FRIDAY HIGH PRESSURE
AND DRY STABLE AIR WILL BUILD IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE ADJUSTMENT TO SKY GRIDS TODAY THROUGH THE NEXT
COUPLE DAYS. ALSO ADJUSTED POPS AND WX BASED ON CURRENT RADAR.
ORIGINAL...MADE ADJUSTMENT TO THE FLOOD WATCH TRIMMING THE
NORTHERN COUNTIES BUT EXTENDING IT A FEW HOURS INTO THE MORNING
FOR THE REMAINING SOUTHERN COUNTIES. RADAR SHOWS THE HEAVY RAIN
MOVING SLOWLY EAST HOWEVER MORE SHOWERS HAVE DEVELOPED ON THE WEST
SIDE OF THE MAIN CONVECTION ACROSS PORTIONS OF CRAWFORD/WYANDOT
AND MARION COUNTIES. RAIN STILL OCCURRING ACROSS THE CENTRAL
LAKESHORE BUT IS NOT INTENSE ENOUGH TO CAUSE FLOODING. FOR THE
MORNING EXPECT THE TREND IN PLACE TO SLOWLY CONTINUE WITH PRECIP
MOVING EAST/SOUTHEAST OF THE AREA AND DRIER AIR MOVING IN FROM THE
NORTHWEST. SHOULD EVENTUALLY SEE SOME SS TODAY HOWEVER HRRR DOES
SHOW SCATTERED CONVECTION REDEVELOPING IN THE MOIST UNSTABLE AIR
STILL IN PLACE ACROSS THE AREA LATER THIS AFTERNOON. BEST CHANCES
WOULD BE WEST/SWRN COUNTIES. WILL BRING CHANCE POPS BACK TO THE
SRN/SWRN COUNTIES WITH SLIGHT CHANCE POPS ON THE NORTH SIDE OF
THAT. HIGHS NEAR GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FOLLOWED MIX OF HPC/NAM AND SREF GUIDANCE FOR THE SHORT TERM. COLD
FRONT IS ON THE WAY FOR WEDNESDAY AND TONIGHT AHEAD OF THE FRONT MODELS
SHOWED A COUPLE SHORT WAVES MOVING ACROSS THE REGION. EXPECTING
SHOWERS/THUNDERSTORMS MOVING IN FROM THE WEST LATE EVENING OR
EARLY IN THE NIGHT AND PERSISTING THROUGH MUCH OF WEDNESDAY. WOULD
ANTICIPATE THE NEED FOR A FLOOD WATCH BUT GIVEN THE CURRENT
HEADLINE WILL WAIT FOR DAY SHIFT TO REEVALUATE. GIVEN HPC QPF
VALUES INCREASED MAV GUIDANCE POPS AGREEING MORE WITH THE SREF
CATEGORICAL GUIDANCE TONIGHT AND WEDNESDAY. THURSDAY AND FRIDAY
SUN AND DRY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODELS HAVE BEEN SLOWLY TRENDING TO A DRIER WEEKEND WITH THE CENTRAL
U.S. RIDGE TRYING TO NOSE INTO THE LOWER GREAT LAKES AND THE TROUGH
SHIFTING TO THE EAST COAST. THIS WILL PUT IS IN THE MIDDLE AND WILL
KEEP THE DRY WEEKEND FORECAST AND THE LOW PRECIP CHANCES FOR MONDAY
WITH AN INCREASE IN MOISTURE. WILL PUT TEMPS IN BETWEEN GFS AND
ECMWF GUIDANCE AS A COMPROMISE SEEMS BEST RIGHT NOW. THAT WILL GIVE
US SEASONABLE TEMPS FOR THE WEEKEND IN THE LOWER TO MID 80S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS REMAIN FOR THE REMAINDER OF
THE NIGHT. IFR WITHIN THESE SHRA/TS. SOME AREAS OF MVFR AS WELL.
BIGGEST TASK IS WHETHER NON VFR CEILINGS OF VSBYS WILL DEVELOP IN
A MORE WIDESPREAD NATURE. LATEST SREF BRINGS IN MVFR AND SOME IFR
ACROSS SOUTHERN MI ACROSS ONTARIO AND INTO NW PA. HAVE LEANED THIS
WAY AND HAVE BROUGHT THE LOWEST CONDITIONS INTO TOLEDO. WITH
DOWNSLOPE FLOW DID NOT GO TOO LOW AT ERIE. EVEN THOUGH THERE IS
PLENTY OF LOW LEVEL MOISTURE...LIGHT WIND AND CURRENT CIGS SHOULD
PREVENT VSBY FROM GETTING TOO LOW. START MOST AT MVFR IN MID
MORNING...IMPROVING TO VFR. MOST OF THE SHOWERS LOOK TO BE OVER BY
AROUND 12Z...BUT AREA MAY GET NEW DEVELOPMENT AGAIN TOWARD YNG/CAK
LATE THIS AFTERNOON. UNSURE ABOUT FDY/MFD. AGAIN THIS IS FOCUSING
ON THE TIMES WITH THE BEST CHANCES...STILL COULD SEE A SHRA/TS AT
JUST ABOUT ANY TIME.
.OUTLOOK...NON-VFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH
WEDNESDAY NIGHT.
&&
.MARINE...
A RELATIVE LULL IN THE THUNDERSTORM CHANCES FOR TODAY. SOUTH-SW FLOW
WILL CONTINUE WITH A NEARLY STATIONARY BOUNDARY JUST NORTH OF THE
LAKE. LOW PRESSURE WILL TRACK ACROSS THE NORTHERN LAKES WEDNESDAY
AND TAKE A COLD FRONT ACROSS LAKE ERIE WITH ANOTHER ROUND OF
THUNDERSTORMS...SOME OF WHICH WILL BE ON THE STRONG SIDE. WINDS MAY
PICK UP ENOUGH TO NEED A SMALL CRAFT ADV WITH THIS SYSTEM. SOME CHOP
POSSIBLE WEDNESDAY AHEAD OF THE FRONT FOR THE EASTERN NEARSHORE WITH
SW FLOW ALONG THE LENGTH OF THE LAKE. BETTER CHANCES FOR SMALL CRAFT
ADV CONDITIONS IN THE NORTHWEST FLOW AFTER THE FRONT. THE WEATHER
SETTLES DOWN THURSDAY THROUGH SATURDAY WITH HIGH PRESSURE OVER THE
CENTRAL GREAT LAKES. WILL HAVE A NORTHERLY FLOW THAT WILL BECOME ENE
BY SATURDAY AS THE HIGH SHIFTS EAST...REMAINING NORTH OF LAKE ERIE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL 9 AM EDT THIS MORNING FOR OHZ027>030-
036-037-047.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK/KOSARIK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
744 AM EDT TUE JUL 9 2013
.SYNOPSIS...
A BERMUDA HIGH ANCHORED OFF THE EASTERN SEABOARD WILL CONTINUE TO
FEED VERY WARM AND HUMID AIR NORTHWARD INTO THE COMMONWEALTH.
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS WILL PERSIST UNTIL A
COLD FRONT PASSES THURSDAY.
&&
.NEAR TERM /UNTIL 4 PM THIS AFTERNOON/...
BROAD SHORT WAVE TROUGH WHICH SEEMS UNDERDONE BY THE MDLS IS
DROPPING ESE FROM OHIO EARLY THIS MORNING. MID LEVEL WINDS
INCREASE FROM THE SW SLIGHTLY THIS MORNING...AND MOISTURE POOLING
AT THE AXIS OF THE TROUGH WILL SLIDE ACROSS THE CWA FROM W-E AS
MAINLY LIGHT SHOWERS AND WIDELY SCT/EMBEDDED THUNDER. HEAVIER RAIN
ON A TRACK TO MOVE TO THE SOUTH OF THE AREA. HRRR SEEMS TO HAVE A
GOOD HANDLE ON RECENT TRENDS. IT PORTRAYS THE DEATH OF MUCH OF
THIS FIRST BATCH OF LIGHT RAIN AS IT MOVES TO THE EAST...THEN A
RE-DEVELOPMENT OF CONVECTION AS DAYTIME HEATING COMBINES WITH
BREAKS IN THE CLOUD COVER TO BUBBLE UP SHRA/TSRA. WITH CLOUDS AND
SCT/NMRS SHOWERS AROUND...WILL KEEP MAXE TEMPS LOOKING LIKE
YESTERDAY/MON. DEWPOINTS ALSO MOVE LITTLE SO ANOTHER SEASONAL JULY
DAY IS IN STORE.
&&
.SHORT TERM /4 PM THIS AFTERNOON THROUGH 6 PM WEDNESDAY/...
THE SHORT WAVE PUSHES TO THE EAST THIS EVENING AND A DECREASE IN
SHRA/TSRA IS EXPECTED FOR MOST OF THE OVERNIGHT HOURS. WILL JUST
LEAVE IN SCT/ISOLD WORDING FOR NOW. HEIGHTS DROP THROUGH THE
NIGHT...THOUGH. THIS OCCURS AS A BROADER AND MORE-SYNOPTIC SCALE
TROUGH AXIS NEARS FROM THE GREAT LAKES/UPPER MIDWEST. THE MOISTURE
PLUME PUSHES RIGHT BACK INTO THE AREA LATE TONIGHT AND HANGS OUT
OVERHEAD THROUGH THE END OF THE PERIOD. A COOL FRONT REACHES THE
LOWER LAKES LATE WED. ALL THIS PUTS THE AREA IN THE WARM SECTOR
AND ALLOWS THE SERN COS TO MAKE ANOTHER RUN AT 90F. THE CLOUDS
WILL BE THE TEMPERING FACTOR ON WEDNESDAY...KNOCKING A FEW DEGS
OFF THE POTENTIAL MAXES. THEY WILL ALSO PLAY A ROLE IN THE
POTENTIAL FOR SEVERE WEATHER ON WEDNESDAY AFTN/EVENING. CAPES O/O
OF 2000 ARE POSSIBLE...BUT MAY NOT BE REALIZED. ALSO...WIND FIELD
IS NOT ALL THAT STRONG AS SPC POINTS OUT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
COOL FRONT SHOULD PUSH INTO THE AEA EARLY WED NIGHT AND MIGHT
CLEAR THE SERN COS BY THURSDAY SUNRISE. HOWEVER...POPS IN THE CHC
RANGE STILL A STRONG FORECAST FOR THE SERN HALF OF THE AREA LATE WED
NIGHT AND ALL THURS DUE TO UNCERTAINTY OF HOW FAR S THE DRIER AIR
WILL BE ABLE TO NUDGE THE CONVECTION.
MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE CONTINUES TO ADVERTISE
ANOTHER ANOMALOUS MERIDIONAL LARGE SCALE PATTERN EARLY IN THE
PERIOD...AS TROUGHING/UPPER LOW DROPS SOUTHWARD ALONG/WEST OF THE
APPALACHIANS...AND FOUR CORNERS RIDGE MAINTAINS ITS POSITION. THE
AMPLIFIED FLOW OVER THE CONUS SHOULD EVOLVE AND REVERT BACK TO A
MORE TYPICAL SUMMERTIME CONFIGURATION DURING THE SECOND HALF OF
THE PERIOD...AS THE JET STREAM RETREATS NORTHWARD TO THE
U.S./CANADIAN BORDER AND LARGE SUBTROPICAL RIDGE TAKES UP
RESIDENCE OVER MUCH OF THE LOWER 48.
IN TERMS OF SENSIBLE WX IMPACTS...A SURGE OF MUCH DRIER/BELOW NORMAL
PWAT AIR SHOULD FOLLOW BEHIND THE COLD FROPA ON THURSDAY. THIS
SHOULD PROVIDE A BRIEF BREAK IN THE HUMID/MUGGY CONDITIONS LATER
THIS WEEK. THE FRONTAL BOUNDARY APPEARS TO STALL-OUT OVER THE SRN
MID-ATLC STATES BEFORE DRIFTING BACK TO THE WEST TOWARD THE
APPALACHIANS...INTERCEPTING A MODEST /NEAR-NORMAL PWATS/ MOISTURE
FLOW AROUND THE BERMUDA HIGH. AS SUCH...LOOK FOR TEMPERATURES AND
TREND UPWARD INTO NEXT WEEK ACCOMPANIED BY RETURNING SUMMERTIME
HUMIDITY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
BANDS OF MAINLY LIGHT SHOWERS ARE MOVING ACROSS CENTRAL PA MAKING
FOR A MOIST START TO THE MORNING. WIDESPREAD MVFR CIGS AND POOR
VSBYS IN FOG WILL PERSIST THROUGH 14Z MOST TAF SITES.
PREDOMINANTLY VFR CONDS ARE LIKELY LATER THIS MORNING AND INTO
EARLY AFTN. HOWEVER...ISOLD LATE DAY THUNDERSTORM IMPACTS ARE
POSSIBLE IN ASSOCIATION WITH LINGERING TROUGH OF LOW PRES OVR THE
AREA.
OUTLOOK...
WED...AM LOW CIGS POSS NW MTNS. SCT TSRA IMPACTS POSSIBLE.
THU...AM LOW CIGS POSS W MTNS. SCT TSRA IMPACTS POSSIBLE.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1048 AM CDT TUE JUL 9 2013
.UPDATE...REST OF TODAY
MAIN FORECAST CHALLENGE TODAY IS WHETHER OR NOT WE WILL HAVE
ADDITIONAL ISO/SCT SHOWER AND STORM DEVELOPMENT LATER TODAY ACROSS
NORTHERN/NORTHEASTERN SD. LAST NIGHTS ACTIVITY IS WELL EAST OF THE
REGION AND CURRENTLY AFFECTING MN/WI. ALTHOUGH...MAIN UPPER LEVEL
WAVE IS STILL SPINNING ACROSS FAR SOUTHERN CANADA WITH THE
SHORTWAVE ENERGY EXPECTED TO MOVE EAST ACROSS THE DAKOTAS TODAY
INTO THIS EVENING. THERE HAVE BEEN A FEW SPOTTY SHOWERS ACROSS
CENTRAL SD...NORTHWEST SD AND SOUTHWEST ND. SFC FRONT HAS CLEARED
THE CWA SO WILL BE HARD TO FOCUS ANYTHING AT THE SFC. 12Z NAM
ALONG WITH THE LATEST RUN OF THE HRRR KEEPS THINGS COMPLETELY DRY
TODAY...WITH ONLY A FEW ISO SHOWERS MOVING SOUTHEAST INTO THE AREA
SHORTLY AFTER 00Z THIS EVENING. OTHER HI-RES MESOSCALE MODELS SHOW
A FEW WDLY SCT STORMS DEVELOPING LATER TODAY. THE LATEST HRRR RUN
IS DEPICTING THE CURRENT SITUATION VERY NICELY AND STARTING TO
THINK IT MAY BE ON TO SOMETHING. HEDGED A BIT ON THE DRY SIDE FOR
POPS TODAY BUT DID NOT WANT TO GO COMPLETELY DRY BASED ON THE
UPPER WAVE ALONE...AND THE FACT THAT ITS ENERGY STILL HAS TO SWING
THROUGH THE REGION LATER TODAY. A COUPLE LIGHT SHOWERS ARE ONGOING
ALONG THE ND/SD BORDER TO THE NORTHWEST. ALSO...SFC DEWPOINTS ARE
STILL IN THE 60S. CANNOT COMPLETELY RULE OUT SOMETHING LATER TODAY
BUT NOT REAL EXCITED ABOUT CHANCES AT THIS POINT. IF
ANYTHING...EXPECT IT TO BE ISO/WDLY SCT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TUESDAY THROUGH THURSDAY
MAIN WEATHER CHALLENGE IN THE SHORT TERM IS PRECIP CHANCES TODAY.
MODELS ARE A LITTLE SLOW MOVING OVERNIGHT CONVECTION ASSOCIATED
WITH A TROF OF LOW PRESSURE THROUGH. THIS IS HAVING RESIDUAL
EFFECTS ON THE QPF FIELD THIS MORNING. LEFT IN SOME POPS ACROSS
THE FAR EAST. STUCK CLOSER TO HI-RES MODELS WHICH HAVE A MOSTLY
DRY MORNING ACROSS THE AREA. THE SFC COLD FRONT SWEEPS INTO THE
EAST THIS AFTERNOON BRINGING CHANCES FOR MORE STORMS. BIGGEST
FORECAST CHALLENGE WITH THIS ROUND OF STORMS IS HOW FAR WEST THEY
WILL EXPAND. FOR NOW HAVE POPS CONFINED TO EAST OF THE JAMES RIVER
VALLEY AS INDICATED ON THE HRRR.
HIGH PRESSURE BUILDS IN TUESDAY NIGHT AND WEDNESDAY. HIGH SHIFTS
TO THE SOUTH AND EAST WEDNESDAY EVENING AHEAD OF ANOTHER TROF.
MODELS INDICATE INCREASED INSTABILITY AHEAD OF THE TROF WITH THE
GFS RAMPING UP THE LLJ WEST OF THE MISSOURI RIVER. KEPT SLIGHT
CHANCE POPS ACROSS THE SOUTHWEST CWA WED NIGHT...BUT IF THE LLJ
PANS OUT MAY NEED TO EXPAND THE POPS NORTH.
TEMPS WILL BE SUPPRESSED BEHIND THIS INITIAL TROF WITH HIGHS IN
THE LOWER 80S TODAY AND WEDNESDAY. AHEAD OF THE NEXT TROF
SOUTHERLY FLOW WILL BOOST TEMPS BACK INTO THE MID 80S TO LOWER 90S
ON THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
THE MODELS ALL SHOW GOOD AGREEMENT THROUGH THE LONG TERM WITH THE
UPPER LEVEL FLOW PATTERN ACROSS OUR REGION. THE PERIOD STARTS OUT
WITH A SHARP 50H RIDGE AXIS EXTENDING ACROSS OUR REGION AND INTO
SOUTHERN CANADA WITH LOW PRESSURE TROUGHING ALONG THE PACIFIC
NORTHWEST COAST. THIS UPPER RIDGE WILL FLATTEN OUT DURING THE LONG
TERM AS THE WEST COAST TROUGHING MOVES ALONG THE NORTHERN US BORDER
FROM SATURDAY THROUGH SUNDAY. A BROAD AREA OF UPPER LEVEL HIGH
PRESSURE WILL THEN EXTEND ACROSS MOST OF THE SOUTHERN US THROUGH
MONDAY WITH OUR REGION ON THE NORTHERN EDGE. FRIDAY WILL STILL BE
THE WARMEST DAY IN THE LONG TERM UNDER THE UPPER LEVEL RIDGE WITH
TEMPERATURES APPROACHING 100 DEGREES ON FRIDAY AFTERNOON SOUTHWEST
IN THE CWA. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE
WEEKEND IN THE MID 80S TO THE LOWER 90S AND MAY BE JUST IN THE 80S
ON MONDAY. HAVE CHANCES OF STORMS FROM MAINLY FRIDAY NIGHT THROUGH
SUNDAY NIGHT ACROSS THE CWA WITH THE UPPER LEVEL LOW PRESSURE
TROUGH SLIDING ACROSS THE REGION ALONG WITH A SURFACE BOUNDARY
PUSHING THROUGH.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TODAY AND
TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TMT
SHORT TERM...WISE
LONG TERM...MOHR
AVIATION...MOHR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
612 AM CDT TUE JUL 9 2013
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 315 AM CDT TUE JUL 9 2013
MAIN CONCERN WILL BE TRACK OF PLAINS THUNDERSTORM COMPLEX THIS
MORNING/TODAY...THEN SEVERE POTENTIAL GOING THIS AFTERNOON.
LOOP OF WATER VAPOR IMAGERY THIS MORNING ALONG WITH RAP 500MB
ANALYSIS SHOWS A FAIRLY VIGOROUS MID-LEVEL TROUGH MOVING OUT OF MT
INTO THE DAKOTAS...WHILE ANOTHER WEAKER WAVE WAS NOTED ACROSS
CENTRAL NEB. 925-850MB MOISTURE TRANSPORT AHEAD OF THESE WAVES WAS
PRODUCING A BROKEN LINE COMPLEX OF THUNDERSTORMS EXTENDING FROM
EASTERN ND/SD...INTO EASTERN NEB. THIS COMPLEX OF STORMS WAS MOVING
EAST AT 30-35KT...MAKING INROADS TOWARD THE AREA. SIMPLE
EXTRAPOLATION BRINGS THIS COMPLEX INTO SOUTHEAST MN/NORTHEAST IA
AROUND 12Z/7AM-ISH.
ARX/HRRR/NMM WRF MODELS DID A PRETTY GOOD JOB INITIALIZING THIS
CONVECTION AND REMAIN IN FAIRLY DECENT AGREEMENT THROUGH THE DAY
TODAY. HAVE TRENDED THE FORECAST TO MATCH UP WITH A BLEND OF THESE
SOLUTIONS. APPEARS THE COMPLEX OF STORMS WILL MAINTAIN
ITSELF...COMING ACROSS THE AREA THIS MORNING AS 925-850MB MOISTURE
TRANSPORT INCREASES/NOSES INTO THE REGION. THIS COMPLEX OF STORMS
HAS A HISTORY OF 30-50KT WINDS ASSOCIATED WITH IT OVER SD.
SO...CANNOT RULE OUT SOME BORDERLINE SEVERE WINDS AS IT ROLLS INTO
OUR AREA. COULD BE INTERESTING GOING INTO THIS AFTERNOON AS THE WRF
MODELS SHOW THIS COMPLEX DEVELOPING A FAIRLY SIGNIFICANT MCV
STRUCTURE. THIS IN TURN HAS THE POTENTIAL OF PRODUCING A
MINI-OUTFLOW/COLD FRONT ON ITS SOUTHWEST FLANK IN THE 18-21Z TIME
FRAME. WITH AMPING SHEAR IN THE 30-40KT RANGE DUE TO THE MCV AND
MORE THAN AMPLE CAPE IN THE 4000-5500J/KG RANGE...LOOKING FOR THE
POSSIBILITY OF A LINE OF SEVERE STORMS WITH DAMAGING WINDS DEVELOPING
ACROSS CENTRAL/SOUTHWEST WI THIS AFTERNOON. THIS OF COURSE WILL ALL
DEPEND ON HOW MUCH CLOUD IS PRESENT WHICH COULD AFFECT THE AMOUNT OF
AVAILABLE INSTABILITY REALIZED. THE POTENTIAL IS DEFINITELY THERE AND
WILL HAVE TO BE WATCHED CLOSELY. ANOTHER THING TO WATCH IS HEAVY
RAINFALL POTENTIAL WITH MUGGY AIRMASS IN PLACE AND PRECIPITABLE WATER
IN THE 2-2.25 INCH RANGE. THIS COULD AID IN TORRENTIAL DOWNPOURS OUT
OF THE STORMS AND SOME LOCALIZED PONDING OF WATER IN POOR DRAINAGE
AREAS.
LOOKING FOR THE MAIN COLD FRONT TO THEN SLIDE SOUTHEAST ACROSS THE
AREA IN THE 00-06Z TIME FRAME. UNCERTAIN ON HOW THIS IS GOING TO
PLAY OUT WITH THE POTENTIAL FOR SEVERE STORMS ALREADY GOING THROUGH
THE AREA THIS AFTERNOON. ATMOSPHERE COULD BE FAIRLY STABILIZED
BEHIND THIS CONVECTION AND COLD FRONT COULD SLIP THROUGH WITH NO
CONVECTION. APPEARS HIGHEST POTENTIAL FOR EVENING CONVECTION MAY BE
ALONG AND NORTH OF I-94 WHERE BETTER 500-300MB PV-ADVECTION WILL
EXIST. EXPECTING COLD FRONT AND ASSOCIATED CONVECTION TO PUSH EAST OF
THE AREA AROUND DAYBREAK AS HIGH PRESSURE BUILDS IN FROM THE
DAKOTAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE JUL 9 2013
HIGH PRESSURE WILL PRODUCE VERY PLEASANT WEATHER CONDITIONS ACROSS
THE AREA WEDNESDAY AND THURSDAY. LOOK FOR HIGHS IN THE 75-80 DEGREE
RANGE ON WEDNESDAY AND UPPER 70S/LOWER 80S ON THURSDAY. MUCH LOWER
HUMIDITY LEVELS WILL ALSO BE NOTED AS DEWPOINTS HOVER IN THE 50S.
PLAN ON WARMER TEMPERATURES ON FRIDAY ALONG WITH INCREASING HUMIDITY
LEVEL AS THE HIGH SLIDES OFF TO THE EAST AND SOUTH WINDS SET UP
ACROSS THE AREA. LOOK FOR HIGHS IN THE 80S WITH A FEW READINGS
FLIRTING WITH THE 90 DEGREE MARK ACROSS SOUTHEAST MN.
EC/GFS ACTUALLY IN PRETTY GOOD AGREEMENT GOING INTO THE WEEKEND.
BOTH MOVE A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER REGION BY
SUNDAY MORNING...THEN HANG IT UP ACROSS WI INTO CENTRAL IA BY
MONDAY. THIS WILL PRODUCE A CHANCE OF SHOWERS AND THUNDERSTORMS FROM
FRIDAY NIGHT STRAIGHT THROUGH MONDAY. OTHERWISE...LOOK FOR
TEMPERATURES TO BE RIGHT AROUND NORMAL LEVELS IN THE 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 611 AM CDT TUE JUL 9 2013
TWO COMPLEXES OF STORMS HEADED TOWARD THE AREA THIS MORNING. THE
FIRST IS MOVING NORTHEAST OUT OF NORTHERN IOWA AND SHOULD BEGIN TO
IMPACT KRST RIGHT AROUND 12Z AND THEN GET INTO KLSE NEAR 14Z.
BRIEF HEAVY RAINS ARE OCCURRING WITH THESE STORMS WITH THE
POTENTIAL TO DROP THE VISIBILITY TO IFR FOR A WHILE WITH MVFR
CEILINGS. THE NEXT COMPLEX IS MOVING QUICKLY EAST ACROSS MINNESOTA
AND LOOKS LIKE IT SHOULD JOIN UP WITH THE NORTHERN IOWA COMPLEX
NEAR THE MISSISSIPPI RIVER. THIS COMPLEX IS PRODUCING VERY SIMILAR
CONDITIONS BUT DOES HAVE A BIT MORE POTENTIAL TO PRODUCE SOME WIND
GUSTS. TO ACCOUNT FOR THESE TWO COMPLEXES HAVE INCLUDED A 3 TO 4
HOUR TEMPO GROUP FOR BOTH AIRPORTS WITH SOME GUSTY WINDS AND IFR
CONDITIONS. HOW QUICKLY THE ACTIVITY MOVES EAST IS STILL A LITTLE
QUESTIONABLE SO HAVE HELD ONTO A VCSH INTO THE AFTERNOON. THE NEXT
ROUND OF STORMS BECOMES POSSIBLE LATE THIS AFTERNOON INTO THE
EVENING AS A COLD FRONT MOVES THROUGH THE AREA. STILL A LOT OF
UNCERTAINTY WHETHER THIS ROUND OF STORMS WILL EVEN OCCUR. THE
09.08Z HRRR IS QUICKER TO BRING THE FRONT THROUGH THIS AFTERNOON
AND THUS DOES NOT ALLOW AS MUCH CAPE TO DEVELOP. BECAUSE OF
THIS...IT PASSES THE FRONT THROUGH WITH JUST A FEW SHOWERS ALONG
IT. THE 09.06Z NAM IS SLOWER WITH THE FRONT ALLOWING MORE CAPE TO
DEVELOP AND HAS ANOTHER ROUND OF STORMS ALONG THE FRONT DURING THE
EVENING. NOT KNOWING HOW LONG THE CLOUDS WILL REMAIN PAST THE
MORNING ACTIVITY HAVE OPTED TO REMAIN WITH A VCTS DURING THE
EVENING FOR BOTH SITES. THE CLOUDS SHOULD QUICKLY CLEAR OUT JUST
BEFORE 06Z AS HIGH PRESSURE STARTS TO BUILD IN AND SPREADS DRIER
AIR INTO THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS PUEBLO CO
333 PM MDT TUE JUL 9 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM MDT TUE JUL 9 2013
...A FEW STRONG STORMS POSSIBLE TOMORROW...
CURRENTLY...CONVECTION A BIT SLOW TO GET GOING...BUT SCT STORMS
DEVELOPING OVER THE MTS...AND LINE OF CU ALONG AND N OF HGWY 50 IS
STARTING TO SEE ISOLD CONVECTION DEVELOP. WILL CONTINUE TO SEE ISOLD
STORMS THIS AFTERNOON AND EVENING OVER THE PLAINS...WITH STORMS MOVING
TO THE S AND E. NOT EXPECTING A LOT OF RAIN WITH MOST OF THESE
STORMS...ALTHOUGH A COUPLE OVER THE FAR SERN GRASSLANDS COULD BE A LITTLE
MORE EFFICIENT RAIN PRODUCERS.
THE HIGH RES WRF AND HRRR CONTINUE TO SHOW THE POTENTIAL FOR
REDEVELOPMENT OF ISOLD SHOWERS AND STORMS OVER THE PALMER DVD AFTER
04Z TONIGHT...LINGERING INTO THE EARLY MORNING HOURS. AM SOMEWHAT
SKEPTICAL AS THERE IS NO REAL UPSTREAM DISTURBANCE TO KICK THINGS
OFF...BUT WILL MAINTAIN LOW/ISOLD POPS THROUGH TONIGHT FOR THAT AREA.
TOMORROW...THE PRECIP/POPS FORECAST GETS TRICKIER. THE GFS HAS VERY
LITTLE QPF OVER THE PLAINS TOMORROW...WHILE THE NAM HAS WIDESPREAD
PRECIP...ESPECIALLY OVER THE ERN PORTIONS OF OUR CWA. HOWEVER...EVEN
THE NAM HAS BACKED OFF ON THE EXTENT OF COOLER AIR MOVING INTO OUR
AREA. LATEST MOS GUIDANCE FOR KPUB IN IN THE MID TO UPPER 90S. THE
QUESTION IS TO WHAT EXTENT THE WEAK FRONTAL PUSH WILL MOVE INTO OUR
AREA. OUTSIDE THE FRONT AND MODEST UPSLOPE...THERE IS NOT MUCH OF A
TRIGGER IN THE FLOW ALOFT TO SUPPORT WIDESPREAD QPF. AM BEING A BIT
CAUTIOUS WITH POPS TOMORROW...KEEPING CHANCE POPS OVER THE PLAINS
IN THE AFTERNOON...BUT LATER SHIFTS MAY NEED TO DO SOME REDUCTIONS
IF THE MODELS CONTINUE A TREND TOWARDS FEWER STORMS. THERE STILL
SHOULD BE FAIRLY WIDESPREAD CONVECTION OVER THE ERN MTS...WITH LIGHT
S TO SE FLOW ACROSS THE PLAINS IN THE AFTERNOON. DEWPOINTS SHOULD BE
IN THE LOWER 50S TO POSSIBLY UPPER 50S CLOSER TO THE KS BORDER. THE
LIGHT WINDS AND INCREASED MOISTURE SHOULD KEEP TEMPS FROM RISING AS
HIGH AS MOS GUIDANCE SUGGESTS.
DEPENDING ON HOW FAR THE FRONTAL BOUNDARY MAKES IT INTO SE
CO...THERE ALSO COULD BE A MARGINAL THREAT OF SVR WX
TOMORROW...ESPECIALLY E OF I-25 AND N OF HGWY 50 IN THE LATE
AFTERNOON AND EARLY EVE. THE HIGHEST THREAT WILL BE OVER KIOWA
COUNTY LATE IN THE DAY...WHERE BULK SHEARS WILL APPROACH 40 KTS OR
SO AND MOISTURE WILL BE GREATEST. COULD SEE SOME HAIL FROM THE
STRONGEST STORMS...ALONG WITH GUSTY WINDS AND BRIEF HEAVY RAINFALL.
ROSE
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM MDT TUE JUL 9 2013
...UPSWING IN THUNDERSTORMS WEDNESDAY EVENING...WITH MONSOON CONTINUING
FOR THE NEXT SEVERAL DAYS...
INTERACTION OF BOUNDARY MOVING THROUGH THE PLAINS AND MONSOON
MOISTURE PROMISES AN UPSWING IN THUNDERSTORM ACTIVITY LASTING
INTO WEDNESDAY EVENING.
THEN...THURSDAY THROUGH SATURDAY...THE MONSOON REGROUPS OVER THE
MOUNTAINS...MAINLY AFFECTING AREAS ALONG AND WEST OF I-25. HIGH
PRESSURE CENTERS OVER EASTERN COLORADO AND WESTERN KANSAS DURING
THIS TIME...DIRECTING THE FLOW OF MOISTURE INTO THOSE AREAS.
BEGINNING SUNDAY...THE HIGH MAY SHIFT EAST FAR ENOUGH TO LET THE
MONSOON SPILL OUT ONTO THE PLAINS...BRINGING AN UPSWING IN
ACTIVITY TO THOSE AREAS.
PRIMARY CONCERNS OVER THE NEXT SEVERAL DAYS WILL BE THE IMPACT OF
HEAVY RAINS ON AREA BURN SCARS. IF HEAVY RAIN DEVELOPS OVER ANY OF
THE SCARS...FLASH FLOODING AND DEBRIS FLOWS WILL BE POSSIBLE. OTHER
CONCERNS THROUGH THE PERIOD WILL BE LIGHTNING...WIND GUSTS TO
AROUND 55 MPH AND LOCAL SMALL HAIL.
ITS STILL SEVERAL DAYS OFF...BUT THE GREATEST POTENTIAL FOR HEAVY
RAINFALL WOULD APPEAR TO MOVE IN OVER THE WEEKEND AS UPPER HIGH
PRESSURE SHIFTS OVER EASTERN COLORADO...ALLOWING MONSOONAL
MOISTURE INFLUX INTO WESTERN COLORADO ON THE WEST SIDE OF THE
HIGH. IN MANY CASES THE RAIN WILL BE BENEFICIAL...BUT THE RISK FOR
FLASH FLOODING AND DEBRIS FLOWS IN AND AROUND AREA BURN SCARS WILL
LIKELY INCREASE DURING THIS PERIOD. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 253 PM MDT TUE JUL 9 2013
VFR CONDITIONS EXPECTED TO CONTINUE AT THE TAF SITES THROUGH
TOMORROW. AS MENTIONED IN PREVIOUS DISCUSSION...STILL THE THREAT OF
ISOLD TS THROUGH EARLY EVENING...AND POSSIBLY LINGERING THROUGH
TONIGHT OVER THE PALMER DVD AND VC KCOS. TOMORROW...SHOULD SEE
A BETTER CHANCE OF STORMS ESPECIALLY ALONG I-25 AND EWD...FROM 18Z
THROUGH 03Z WED EVE. A FEW OF THESE STORMS COULD BE ON THE STRONG
SIDE..ESPECIALLY E OF I-25 AND N OF HGWY 50. HAIL UP TO AN INCH AND
LOCALLY HEAVY RAINFALL...ALONG WITH WIND GUSTS TO 50 KTS...WILL BE
POSSIBLE WITH THE STRONGEST STORMS TOMORROW. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ROSE
LONG TERM...LW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1048 AM MDT TUE JUL 9 2013
.UPDATE...WATER VAPOR IMAGERY...MORNING RAOBS AND INTEGRATED
PRECIPITABLE WATER PRODUCTS ALL INDICATE A MUCH DRIER AIRMASS OVER
THE FORECAST AREA TODAY. MODEL SOUNDINGS FROM THE NAM AND RAP ALSO
SHOW MID-LEVEL CAPPING OVER MOST OF THE PLAINS THROUGH THE
AFTERNOON. THE EXCEPTION TO THIS IS EAST OF A LIMON-AKRON LINE
WHERE 1000-1500 J/KG OF CAPE WILL BE PRESENT DURING THE EARLY
EVENING. MOUNTAIN AREAS SHOULD STILL SEE ISOLATED THUNDERSTORMS
THIS AFTERNOON...BUT THE SHOWERS WILL RAPIDLY EVAPORATE AS THEY
MOVE OFF THE FOOTHILLS...SIMILAR TO YESTERDAY AFTERNOON. WILL
UPDATE THE FORECAST TO REMOVE MENTION OF THUNDERSTORMS ON THE
PLAINS THIS AFTERNOON AND EVENING. WILL HOLD ONTO ISOLATED
THUNDERSTORMS OVER THE EASTERN TIER OF COUNTIES AFTER 00Z.
HOT TEMPERATURES ARE GOING TO BE THE MAIN STORY THIS
AFTERNOON...AS WE HAVE ALREADY REACHED 92 AT KDEN. THE RECORD FOR
THE DAY IS 98...WHICH MAY TUMBLE DURING THE MID-LATE AFTERNOON.
&&
.AVIATION...NO AVIATION IMPACTS THROUGH THIS AFTERNOON AND
EVENING. WINDS WILL SWITCH TO LIGHT AND NORTHERLY DURING THE
AFTERNOON...AHEAD OF A MORE SIGNIFICANT FRONTAL PUSH LATER THIS
EVENING.
&&
.HYDROLOGY...AFTERNOON SHOWERS WILL ONLY PRODUCE LIGHT AMOUNTS OF
RAIN...SO NO PROBLEMS ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 249 AM MDT TUE JUL 9 2013/
SHORT TERM...AN UPPER LEVEL HIGH WILL BE OVER SWRN CO WITH WEAK
WNW FLOW ALOFT ACROSS NRN CO. WATER VAPOR IMAGERY SHOWS BEST PLUME
OF SUBTROPICAL MOISTURE ACROSS SRN CO WHICH IS FCST TO STAY IN THE
SAME GENERAL AREA. AT THE SFC A WK PRE FNTL BNDRY WILL MOVE ACROSS
NERN CO TODAY AND FLUSH OUT LOW LVL MOISTURE EXCEPT POSSIBLY OVER
THE FAR NERN CORNER. AT THIS TIME TSTM THREAT OVER NERN CO LOOKS
RATHER ISOLD AND HIGH BASED. OVER THE HIGHER TERRAIN WILL KEEP IN
WDLY SCT TSTMS. AS FOR HIGHS READINGS WILL RISE ANOTHER FEW
DEGREES WITH TEMPS IN THE 95 TO 100 DEGREE RANGE OVER THE PLAINS.
RECORD HIGH AT DENVER IS 98 WHICH COULD BE TIED OR BKN.
FOR TONIGHT A CDFNT WILL MOVE ACROSS NERN CO OVERNIGHT AND BRING AN
INCREASE IN LOW LVL MOISTURE ALL THE WAY BACK INTO THE FOOTHILLS BY
12Z. AT THIS POINT REALLY CAN`T SEE ANYTHING TO ENHANCE CONVECTION
HOWEVER IF A WK DISTURBANCE WERE TO MOVE ACROSS THEN THAT COULD
CHANGE THINGS DRAMATICALLY. FOR NOW WILL JUST KEEP LOW POPS IN
OVERNIGHT ACROSS THE PLAINS.
LONG TERM...NO SIGNIFICANT CHANGES AT THIS TIME. ON WEDNESDAY
LOW LEVEL MOISTURE WILL INCREASE ACROSS NORTHEAST COLORADO
FOLLOWING THE PASSAGE OF A WEAK COLD FRONT. SFC WINDS WILL ALSO
BACK AROUND TO THE SE WHICH WOULD LEAD TO THE DEVELOPMENT OF A
DENVER CYCLONE IN THE LATE AFTN/EVNG. MDLS VARY GREATLY REGARDING
THE FCST QPF AMOUNTS BUT THEY ALL INDICATE RAINFALL. IN
ADDITION...SHEAR PROFILE INDICATIVE OF SOME SEVERE TSTM POTENTIAL
AS WELL. FCST CAPES FM THE GFS BUFFER SOUNDINGS AROUND 1000 J/KG
AT KDEN AROUND 21Z...WITH 1600 J/KG FM THE NAM12. PW VALUES FM
BOTH SOUNDINGS IN EXCESS OF ONE INCH...SO WILL SIDE WITH THE
HEAVIER QPF AMOUNTS FM THE GFS BUFFER SOUNDINGS. SIMILAR VALUES
FCST FOR THE NERN PLAINS OF CO AS WELL. ON THURSDAY THE AMS WILL
BE DRIER ALONG THE URBAN CORRIDOR...WITH BETTER POTENTIAL OVER THE
NERN PLAINS WHERE THE BEST LOW LEVEL MOISTURE WILL BE. THE RIDGE
ITSELF WILL MOVE FM THE FOUR CORNERS REGION 00Z THU TO THE
OKLAHOMA/TEXAS PANHANDLES BY 00Z FRI. THE CENTER OF THE RIDGE WILL
SHIFT A BIT FURTHER EASTWARD BY THE WEEKEND. BEST CHC OF TSTMS
DURING THE WEEK WILL BE WEDNESDAY AFTN/EVNG...MAYBE A LITTLE LESS
COVERAGE ON THURSDAY. FRIDAY THROUGH SUNDAY...SUBTROPICAL MOISTURE
WILL INCREASE ACROSS WRN AND NRN CO AND FRIDAY THROUGH SUNDAY AS
WILL THE CHC OF THUNDERSTORMS. THE MOISTURE IS PROGGED TO MOVE FM
BAJA INTO CO IN THAT TIME. HEAVY RAIN POTENTIAL WILL EXIST ACROSS
THE CWFA EACH AFTN/EVNG...ESPECIALLY OVER THE WEEKEND...WITH THE
STORMS.
AVIATION...SFC WINDS WERE SSW EARLY THIS MORNING BUT SHOULD
BECOME LIGHT WNW AROUND 14Z AND THEN MORE NNE BY 17Z. BY LATE AFTN
THEY MAY BECOME MORE ELY AND THEN SELY BY 01Z. AT THIS TIME TSTM
THREAT LOOKS LOW THRU THIS AFTN INTO THE EARLY EVENING HOURS SO
WILL NOT MENTION IN THE TAF.
FOR TONIGHT A COLD FRONT WILL MOVE INTO THE AREA AFTER MIDNIGHT.
THERE IS SOME POTENTIAL FOR STRATUS IN THE 12Z-15Z TIMEFRAME ON
WED.
HYDROLOGY...ISOLD TO WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP
THIS AFTERNOON HOWEVER THEY WILL BE RATHER HIGH BASED SO RAINFALL
AMOUNTS SHOULD BE UNDER A QUARTER INCH.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DANKERS
LONG TERM....99
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
421 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A FEW SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL
AFFECT THE REGION AT TIMES THROUGH FRIDAY. AT THIS POINT...THE
SHOWERS AND THUNDERSTORMS LOOK TO BE MOST WIDESPREAD ON THURSDAY.
MAINLY DRY AND LESS HUMID WEATHER LOOKS FINALLY ARRIVE BY THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
430 PM UPDATE...
UPDATED FORECAST TO ACCOUNT FOR CURRENT TRENDS OTHERWISE
THE FORECAST REMAINS ON TRACK FOR THE LATE AFTERNOON. INTERESTING
SET-UP ACROSS THE REGION THIS AFTERNOON. LINGERING BOUNDARY FROM
YESTERDAYS BACK DOOR COLD FRONT IS STATIONED NORTH OF CQX TO HFD THEN
JETS NORTHWARD ACROSS THE BERKSHIRES. THIS BOUNDARY WILL REMAINS
NEARLY STATIONARY AND WILL CONTINUE TO BE THE FOCUS ON WHERE
CONVECTION WILL CONTINUE. TEMPERATURES NORTH OF THE BOUNDARY ARE
IN THE UPPER 60S TO MID 70S...WHILE SOUTH OF THE BOUNDARY TEMPS
HAVE WARMED INTO THE MID 80S.
20Z RADAR IMAGERY SHOWS SCATTERED SHOWERS AND THUNDER THAT HAS
DEVELOPED ALONG THE BOUNDARY. ALSO SEVERAL OUTFLOW BOUNDARIES FROM
TODAYS THUNDERSTORMS ARE INTERSECTING EVERYWHERE. INTERESTING TO
SEE HOW STORMS WILL EVOLVE LATER THIS AFTERNOON. BELIEVE THAT
THEY WILL CONTINUE TO FIRE ACROSS NH AND ALONG THE CAPE AND SE
MASS WHERE THE BETTER CONVERGENCE IS LOCATED AS WELL AS THE
ENVIRONMENT HAS NOT BEEN WORKED OVER AS MUCH. ML CAPE VALUES ARE
BETWEEN 1000-1500 J/KG ACROSS RHODE ISLAND AND THE CT VALLEY AND
THE BERKSHIRES. SHEAR IS NEARLY NON-EXISTENT SO THESE STORMS WILL
HARDLY MOVE AND WITH PWAT VALUES NEAR 1.7 TO 2 INCHES EXPECT HEAVY
DOWNPOURS WITH THESE CELLS. VERY LOCALIZED FLASH FLOODING IS THE
MAIN CONCERN WITH WIND GUSTS BEING THE SECOND CONCERN. EXPECT
STORMS TO CONTINUE TO FIRE OFF OF THIS BOUNDARY OVER THE NEXT
SEVERAL HOURS. LATEST MESOSCALE MODELS ALSO SUPPORT THIS THEORY AS
THE HRRR SEEMS TO BE DOING A GREAT JOB WITH ONGOING CONVECTION.
TONIGHT...
CURRENT CONVECTION ACROSS THE REGION SHOULD SLOWLY WANE AFTER
SUNSET AS DIURNAL HEATING IS LOST. A FEW SHOWERS MAY CONTINUE TO
LINGER OVERNIGHT BUT THE THREAT FOR STRONG TO SEVERE STORMS WILL
BE LOW. MAIN CONCERN WILL BE THE POTENTIAL FOR LOW CLOUDS AND FOG
AGAIN. BELIEVE THAT BOTH COAST LINES WILL BE AT RISK AS EASTERLY
FLOW IS ACROSS THE EAST COAST AND SOUTHERLY FLOW ONTO THE SOUTH
COAST. THIS WILL KEEP THE MOISTURE STREAMING INTO THE REGION
ALLOWING FOR FOG TO DEVELOP.
OTHERWISE SURFACE LOW WILL MOVE EASTWARD OVERNIGHT PUSHING
THE CURRENT BOUNDARY THAT IS DRAPED ACROSS SE MA/RI AND INTO CT
NORTHWARD AS A WARM FRONT OVERNIGHT AND INTO TOMORROW MORNING.
OVERNIGHT TEMPS WILL BE PLEASANT NORTH OF THE BOUNDARY...IN THE LOW
TO MID 60S. SOUTH OF THE BOUNDARY TEMPS WILL BE IN THE UPPER 60S TO
LOW 70S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TOMORROW...
A LOT OF UNCERTAINTY STILL IS IN PLACE FOR TOMORROW. UPPER LEVEL
LOW OVER THE UPPER GREAT LAKES WILL CONTINUE THE TROUGH OVER THE
REGION. QUICK MOVING SHORTWAVE WILL MOVE THROUGH THE FLOW ALLOWING
FROM SOME SORT OF LIFT FOR THE REGION. HOWEVER LOOKING AT FORECAST
GUIDANCE IT SEEMS THE AREA THAT MAY SEE THE BETTER POTENTIAL FOR
STORMS WILL BE OUT WEST ACROSS THE CT VALLEY/ORH HILLS. THIS REGION
WILL HAVE THE BETTER INSTABILITY ONCE THE LOW STRATUS DECK BREAKS
UP.
CURRENT BOUNDARY ACROSS THE REGION NOW WILL LIFT NORTHWARD AS A
FORM OF A WARM FRONT WHEN THE SHORTWAVE APPROACHES. THIS WILL ALLOW
FOR TEMPS TO WARM RIGHT BACK UP INTO THE MID TO UPPER 80S. BELIEVE
THAT STORMS WILL MAINLY BE DIURNALLY DRIVE DURING THE DAY. WITH
LACK OF SHEAR AND FLOW ALOFT BELIEVE THESE STORMS WILL BE NEARLY
STATIONARY AND WITH PWATS IN THE 1.5 TO 2 INCHES...HEAVY DOWNPOURS
WILL BE THE MAIN THREAT. CAPE VALUES SHOULD BE HIGHER THEN TODAY
SO GUSTY WINDS MAY ALSO BE A POTENTIAL ONCE THUNDERSTORMS BEGIN TO
COLLAPSE. STORMS SHOULD BEGIN TO WANE AFTER SUNSET ONCE DIURNAL
HEATING IS LOST.
TOMORROW NIGHT...
AFTER A QUICK LULL IN CONVECTION MODELS ARE INDICATING THAT STORMS
WILL FIRE UP OVERNIGHT AND LAST INTO THE THURSDAY. SYNOPTIC MODELS
ARE STRUGGLING WITH PLACEMENT OF THE COLD FRONT AS THE GFS BRINGS IT
ACROSS SNE FASTER THEN THE GENERAL TREND. ALSO AM HESITANT AS THESE
SORT OF FRONTS HAVE THE TENDENCY TO STALL. HOWEVER IF THE FRONT
MOVES TOWARDS THE REGION LATE TOMORROW NIGHT INTO THURSDAY MORNING
THEN THE OVERNIGHT HOURS MAY BE ACTIVE.
FORECAST GUIDANCE SHOWS ELEVATED INSTABILITY ACROSS THE REGION AS
SHOWALTERS ARE -2C COMBINED WITH DEEP MOISTURE AND A SOURCE OF LIFT
WHICH COULD HAVE STORMS FIRING OVERNIGHT. EXACT COVERAGE AND
PLACEMENT IS STILL UNKNOWN AS THE TIMING IS THE OVERALL QUESTION.
HOWEVER MAIN THREAT APPEARS TO BE HEAVY DOWNPOURS. HAVE CONTEMPLATED
WITH THE ISSUANCE OF A FLASH FLOOD WATCH BUT HAVE COLLABORATION WITH
SURROUND OFFICES DECIDED TO HOLD OFF AS THERE IS STILL A LOT OF
UNCERTAINTY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HEADLINES...
* HEAVY RAIN AND POTENTIAL FLOODING FOR THURSDAY
* RAINS LINGER TO THE SOUTHEAST INTO FRIDAY
* A RETURN OF MORE SEASONABLE WEATHER INTO THE WEEKEND AND EARLY WEEK
*/OVERVIEW AND MODEL CONSENSUS...
THOUGH MODELS AGREE UPON A BROAD RIDGING PATTERN EVOLVING ACROSS THE
CONUS...THEY REMAIN AT ODDS AND STRUGGLE WITH HANDLING ENERGY ALONG
THE NORTHERN PERIPHERY OF THE RIDGE. CONSEQUENTIALLY...RUN-TO-RUN
CONSISTENCY HAS BEEN POOR AS OF LATE WITH HANDLING THE EVOLUTION OF
THE MID- TO UPPER-LEVEL ENERGY DIVING SOUTHEAST OUT OF CANADA AND
ACROSS THE NORTHEASTERN CONUS...POTENTIALLY EVOLVING INTO A CLOSED
LOW THAT RETROGRADES SOUTH AND WEST.
HPC/WPC MAINTAINS CONTINUITY WITH THEIR FORECAST...GOING WITH A
09.0Z ENSEMBLE BLEND...NOTING THE UNCERTAIN TRACK OF TROPICAL STORM
CHANTAL. WILL FOLLOW SUIT INCORPORATING THEIR FORECAST INTO A BLEND
OF THE 09.12Z FORECAST GUIDANCE.
*/DAY-TO-DAY DETAILS...
*/THURSDAY INTO THURSDAY NIGHT...
SURFACE COLD FRONT SLOWED ACROSS SOUTHERN NEW ENGLAND AGAINST
RIDGING OF HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL BE FORCED
OFFSHORE DURING THE EVENING HOURS AND OVERNIGHT AS THE MID- TO UPPER-
LEVEL TROUGH AXIS PUSHES SOUTHEAST OUT OF CANADA INTO THE NORTHEAST
CONUS. FEEL 09.12Z GFS IS TOO FAST WITH THIS FEATURE.
CHANCE TO LIKELY POPS WARRANTED THURSDAY WITH DEEP-LAYER FORCING
COUPLED WITH THE RIGHT-ENTRANCE REGION OF THE UPPER-LEVEL JET...
DIMINISHING INTO THE EVENING WITH THE COLD FRONT PUSHING OFFSHORE.
WITH CERTAINTY...COLD POOL WILL PUSH SOUTHEAST IMPROVING MID-LEVEL
LAPSE RATES AS UNI-DIRECTIONAL SOUTHWESTERLY SHEAR INCREASES TO
AROUND 30 KTS ACROSS THE REGION. SO WHILE ELEVATED INSTABILITY IS
PLAUSIBLE...BOUNDARY LAYER DESTABILIZATION IS QUESTIONABLE AS
ACTIVITY COULD BE ONGOING DURING THE MORNING FORCED BY STRONG LOW-
LEVEL CONVERGENCE. CLOUDS IMPEDING DIURNAL HEATING.
LESSER CONFIDENCE OF A SEVERE WEATHER THREAT...GREATER CONCERN FOR
FLOODING WITH 2-INCH PWATS AND AFOREMENTIONED DEEP-LAYER FORCING.
GREATER CHANCE FOR FLOODING ACROSS CENTRAL AND EASTERN PORTIONS OF
SOUTHERN NEW ENGLAND...FOCUSING ON THE MORNING INTO MIDDAY PERIOD.
*/FRIDAY INTO NEXT WEEK...
IT IS NOT ENTIRELY CLEAR HOW THE MID- TO UPPER-LEVEL ENERGY
ASSOCIATED WITH THE ACTIVITY ON THURSDAY WILL EVOLVE. DETERMINISTIC
GFS/ECMWF SOLUTIONS EXHIBIT ATTENDANT ENERGY TO BIFURCATE FROM THE
NORTHERN STREAM...BECOMING A CLOSED LOW AND RETROGRADING SOUTH AND
WEST WITH THE MEAN FLOW AROUND THE BROAD RIDGING ACROSS THE CONUS.
QUITE ODD FOR AN EARLY SUMMERTIME PATTERN.
THAT BEING SAID...SURFACE OUTCOMES REMAIN UNCERTAIN. IT APPEARS HIGH
PRESSURE OUT OF THE GREAT LAKES REGION WILL USHER MORE SEASONABLE
CONDITIONS BACK INTO THE REGION WITH NORTHERLY WINDS...AS A FRONTAL
BOUNDARY REMAINS STALLED OFFSHORE. COULD SEE THE CHANCE OF SHOWERS
FOR FAR SOUTHEAST SOUTHERN NEW ENGLAND INITIALLY. THIS HIGH WILL
TRANSITION EAST RESULTING IN THE RETURN USHERANCE OF SOUTHERLY FLOW
AND PERHAPS RENEWED CHANCES OF SHOWERS AND THUNDERSTORMS AS HEAT AND
HUMIDITY GRADUALLY BUILD BACK OVER THE REGION.
LITTLE FORCING WITHIN THE MID- TO UPPER-LEVELS IS APPARENT...SO ANY
SHOWERS OUTPUTTED BY FORECAST GUIDANCE APPEARS TO BE A RESULT OF
LOCALIZED CONVERGENCE LIKELY ALONG SEA-BREEZE BOUNDARIES /AIR-MASS
THUNDERSTORMS/. CHANCE TO SLIGHT CHANCE POPS ACROSS THE INTERIOR...
LOW CONFIDENCE SEVERE WEATHER THREATS. WILL KEEP CONDITIONS CLOSE TO
SEASONABLE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...TODAY THROUGH WEDNESDAY...
MODERATE CONFIDENCE ON TRENDS...LOW CONFIDENCE ON TIMING.
TODAY...MVFR ACROSS MUCH OF THE REGION WITH IFR ACROSS THE CAPE.
BOUNDARY IS SITUATED GENERALLY FROM KACK-KMMK-KAQW. NORTH AND EAST
OF THE BOUNDARY IS IN EASTERLY TO NORTHEAST FLOW WHILE SOUTH AND
WEST OF THE BOUNDARY IS DUE SOUTH. EXPECT THE CT VALLEY TO BREAK
OUT INTO VFR HOWEVER EVERYWHERE ELSE SHOULD STAY SOCKED IN. VCTS
CONDITIONS ARE BEST FOR PVD/BAF/BDL AS TSRA ARE FIRING ACROSS THE
BOUNDARY.
TONIGHT...MVFR TO IFR CONDITIONS WILL DETERIORATE TO IFR/LIFR
OVERNIGHT. EASTERLY FLOW WILL SOCK THE EAST COAST IN LOW CLOUDS
AND FOG. LIFR CONDITIONS ARE BEST ACROSS THE CAPE.
WEDNESDAY...MAINLY MVFR/VFR CONDITIONS WITH BETTER CHANCE FOR
SHOWERS/TSTMS ESPECIALLY ORH HILLS WESTWARD.
WEDNESDAY NIGHT...MVFR TO IFR CONDITIONS OVERNIGHT AS SHRA AND
TSRA GROW IN COVERAGE OVERNIGHT ESP ACROSS WESTERN TERMINALS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS...LOWER IN TIMING
SPECIFICS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS...LOWER IN
TIMING SPECIFICS. CONTINUED TO MENTION VCTS AS SHOWERS AND TSRA
CONTINUE TO DEVELOP ALONG BOUNDARY.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE
THURSDAY INTO THURSDAY NIGHT...
SHRA/TSRA...BETTER CHANCES DURING THE MORNING INTO MIDDAY HOURS
PUSHING NW TO SE. MVFR/IFR CIGS WITH MVFR/IFR VSBYS...CONDITIONS
POTENTIALLY LOWER WITH +RA AND ACROSS SE COASTAL TERMINALS WITH FOG.
SW WINDS BACKING OUT OF THE W/NW WITH COLD FRONTAL PASSAGE.
FRIDAY INTO SUNDAY...
SHRA/TSRA MAY LINGER ACROSS FAR SE COASTAL TERMINALS DURING THE
INITIAL PERIOD WITH MVFR-IFR IMPACTS AT LOWEST. OTHERWISE PREVAILING
VFR WITH NORTHERLY WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...HIGH CONFIDENCE.
TODAY THROUGH WEDNESDAY...
WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TOMORROW. AS WINDS SHIFT BACK TO S-SW AND PICK UP DURING WED
AFTERNOON...WITH GUSTS UP TO 20 KT...SEAS MAY BUILD BACK UP TO
AROUND 5 FT ON THE SOUTHERN WATERS. SMALL CRAFT ADV MAY BE NEEDED
THEN. SEEMS THAT WNA GUIDANCE WAS OVERDOING THE SEAS AGAIN SO
HAVE UNDERCUT THEM. EXPECT REDUCED VSBYS TONIGHT INTO TOMORROW
MORNING FROM FOG. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ON
WED INTO WED NIGHT.
OUTLOOK...THURSDAY INTO SUNDAY...MODERATE CONFIDENCE.
THURSDAY INTO THURSDAY NIGHT...
RAIN AND POSSIBLE THUNDERSTORMS WILL INCREASE TOWARDS THE WATERS
DURING THE DAY AND PREVAIL INTO THE EVENING ALONG AND AHEAD OF AN
APPROACHING COLD FRONT. STORMS MAY BE STRONG WITH GALE FORCE
GUSTS...OTHERWISE PREVAILING SW WINDS AHEAD OF THE COLD FRONT
BACKING OUT OF THE W/NW LATE. SEAS IN EXCESS OF 5 FEET ON THE OUTER
WATERS. VISIBILITY IMPACTS WITH HEAVY RAIN ANTICIPATED.
FRIDAY INTO SUNDAY...
RAIN AND POSSIBLE THUNDERSTORMS WILL LINGER FOR THE INITIAL PERIOD
SLOWLY MOVING INTO THE ATLANTIC. HIGH PRESSURE BUILDING FROM THE
WEST WILL RESULT IN NORTHERLY FLOW. COULD SEE GUSTS UP TO AROUND 20
KTS WHICH WOULD ALLOW SEAS ON THE OUTER WATERS TO REMAIN AT OR ABOVE
5 FEET.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DUNTEN/SIPPRELL
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...SIPPRELL
AVIATION...DUNTEN/SIPPRELL
MARINE...DUNTEN/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
202 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A FEW SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL
AFFECT THE REGION AT TIMES THROUGH FRIDAY. AT THIS POINT...THE
SHOWERS AND THUNDERSTORMS LOOK TO BE MOST WIDESPREAD ON THURSDAY.
MAINLY DRY AND LESS HUMID WEATHER LOOKS FINALLY ARRIVE BY THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
200 PM UPDATE...
UPDATED FORECAST TO ACCOUNT FOR CURRENT TRENDS OTHERWISE GENERALLYFORECAST
REMAINS ON TRACK FOR THIS AFTERNOON. INTERESTING SET-UP ACROSS THE
REGION THIS AFTERNOON. LINGERING BOUNDARY FROM YESTERDAYS BACK
DOOR COLD FRONT IS STATIONED NORTH OF ACK TO MMK THEN JETS
NORTHWARD ACROSS THE BERKSHIRES. THIS BOUNDARY WILL REMAINS
NEARLYSTATIONARYAND WILL BE THE FOCUS ON WHERE CONVECTION WILL
FIRE. TEMPERATURES NORTH OF THE BOUNDARY ARE IN THE UPPER 60S TO
MID 70S...WHILE SOUTH OF THE BOUNDARY TEMPS HAVE WARMED INTO THE
MID 80S.
18Z RADAR IMAGERY SHOWS A GOOD AMOUNT OF STORM COVERAGE THAT HAS
DEVELOPED ALONG THIS BOUNDARY. SATELLITE IMAGERY ALSO SHOWN SOME
CLEARING ALLOWING FOR SOME DIURNAL HEATING. ML CAPE VALUES ARE
BETWEEN 500-1000 J/KG ACROSS RHODE ISLAND AND THE CT VALLEY. SHEAR
IS NEARLY NON-EXISTENT SO THESE STORMS WILL HARDLY MOVE AND WITH
PWAT VALUES NEAR 1.7 TO 2 INCHES EXPECT HEAVY DOWNPOURS WITH THESE
CELLS. VERY LOCALIZED FLASH FLOODING IS THE MAIN CONCERN WITH WIND
GUSTS BEING THE SECOND CONCERN. EXPECT STORMS TO CONTINUE TO FIRE
OFF OF THIS BOUNDARY THROUGHOUT THE AFTERNOON HOURS. LATEST
MESOSCALE MODELS ALSO SUPPORT THIS THEORY AS THE HRRR SEEMS TO BE
DOING A GREAT JOB WITH ONGOING CONVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
WILL SEE LEFTOVER SCT SHOWERS/TSTMS...SOME OF WHICH WILL BE HEAVY
RAINERS...THAT WILL TEND DWINDLE AFTER THE HEATING OF THE DAY.
SOME MAY LINGER WEST OF THE CT RIVER AND THE E SLOPES OF THE
BERKSHIRES AS K INDICES SURGE TO THE MID 30S OVERNIGHT. MAY ALSO
SEE ANOTHER WEAK SHORT WAVE MOVE OUT OF N NEW ENGLAND AFTER
MIDNIGHT...SO MAY RENEW CHANCE FOR PRECIP ACROSS CENTRAL AND
EASTERN AREAS.
WEDNESDAY...
APPEARS THAT THE STALLED FRONT MAY MAKE A RUN N OF THE REGION
DURING THE DAY AS WINDS SHIFT BACK TO S-SW DOWN THE COAST. LOOKS
LIKE ANOTHER WAVE MOVES ALONG THIS FRONT AS WELL. THIS WILL
ENHANCE CHANCES FOR PRECIP AS SURGE OF HIGHER PWATS...ON ORDER OF
AROUND 2 INCHES...WORK NE INTO THE REGION. WITH THE TROPICAL
CONNECTION BACK IN PLACE...WILL SEE ANOTHER ROUND OF SHOWERS/TSTMS
FOR MOST AREAS THROUGH MIDDAY...THEN MAY ACTUALLY SHIFT A BIT TO
THE W DURING THE AFTERNOON. CONTINUED WITH LIKELY POPS FOR SW NH/W
MA/N CENTRAL CT WHERE BEST LIFT/INSTABILITY WILL REMAIN THROUGH
THE DAY. TEMPS WILL ALSO SPIKE UP...EVEN WITH THE PRECIP AROUND...
UPWARDS TO THE MID-UPPER 80S ACROSS THE MID AND LOWER CT VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* A ROUND OF SHOWERS/THUNDERSTORMS LIKELY THU WITH HEAVY RAINFALL
* A FEW LEFT OVER SHOWERS/STORMS MAY LINGER INTO FRI
* RELIEF FROM HUMIDITY EXPECTED BY THIS WEEKEND
DETAILS...
WEDNESDAY NIGHT...
THERE IS UNCERTAINTY ON HOW MUCH CONVECTION WILL BE ON GOING IN OUR
REGION WEDNESDAY EVENING. WHILE WE MAY SEE SOME ACROSS OUR INTERIOR
ZONES...THE BETTER FOCUS WILL BE TO THE WEST OF OUR REGION CLOSER TO
THE SHORTWAVE/INSTABILITY AXIS. HOWEVER...WE MAY SEE AN INCREASE IN
SCATTERED SHOWERS/THUNDERSTORMS DURING THE OVERNIGHT HOURS AS LOW
LEVEL JET KICKS IN AHEAD OF THE SHORTWAVE. THE FAR SOUTHEAST NEW
ENGLAND COAST IS OFTEN PRONE TO THIS TYPE OF ELEVATED CONVECTION AND
SOME MODELS SEEM TO BE HINTING AT THIS POTENTIAL. LOCALLY HEAVY
RAINFALL WOULD BE A CONCERN GIVEN HIGH PWATS IN PLACE.
THURSDAY...
UPPER LEVEL SHORTWAVE AND SURFACE TROUGH WILL MOVE
THROUGH THE REGION ON THURSDAY. WE ARE FAIRLY CONFIDENT THAT THIS
SHOULD GENERATE A ROUND OF SHOWERS AND THUNDERSTORMS ACROSS MOST OF
THE REGION. THEREFORE...WILL CARRY LIKELY POPS BUT THERE IS
UNCERTAINTY ON THE EXACT TIMING.
THE MAIN THREAT WILL BE HEAVY RAINFALL AND LOCALIZED FLOODING.
WIDESPREAD SEVERE WEATHER APPEARS UNLIKELY GIVEN A FAIR AMOUNT OF
CLOUD COVER AND LIMITED 0 TO 6 KM SHEAR. HOWEVER...MID LEVEL LAPSE
RATES WILL BE A LITTLE BETTER THAN RECENT DAYS SO A FEW STRONG TO
SEVERE THUNDERSTORMS CAN/T BE RULED OUT. THE BULK OF THE SHOWERS
AND THUNDERSTORMS WILL PROBABLY COME TO AN END DURING THURSDAY
EVENING.
FRIDAY...
APPEARS COLD FRONT WILL HAVE MOVED TO NEAR THE COAST OR
JUST OFF THE COAST BY THIS TIME. HOWEVER...UPPER TROUGH/COLD POOL
ALOFT WILL STILL BE LINGERING TO THE WEST OUR REGION.
THEREFORE...OPTED TO KEEP CHANCE POPS IN THE FORECAST FOR PERHAPS
A FEW MORE SHOWERS AND THUNDERSTORMS BUT NOT EXPECTING THE ENTIRE
DAY TO BE A WASHOUT.
SATURDAY THROUGH MONDAY...
UPPER TROUGH WILL HANG AROUND SOUTHERN NEW
ENGLAND...BUT THERE WILL BE HIGH PRESSURE AT THE SURFACE.
THEREFORE...LEANING TO MAINLY DRY WEATHER WITH SEASONABLE HIGH
TEMPERATURES MAINLY IN THE 80S. WILL HAVE TO WATCH A FEW WEAK WAVES
OF LOW PRESSURE PASSING TO OUR SOUTHEAST. IF THEY COME CLOSER THAN
EXPECTED SOME OF OUR AREA COULD BE GRAZED BY A FEW SHOWERS...BUT FOR
NOW KEEPING THE BULK OF THEM OFF THE COAST.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...TODAY THROUGH WEDNESDAY...
MODERATE CONFIDENCE ON TRENDS...LOW CONFIDENCE ON TIMING.
TODAY...MVFR ACROSS MUCH OF THE REGION WITH IFR ACROSS THE CAPE.
BOUNDARY IS SITUATED GENERALLY FROM KACK-KMMK-KAQW. NORTH AND EAST
OF THE BOUNDARY IS IN EASTERLY TO NORTHEAST FLOW WHILE SOUTH AND
WEST OF THE BOUNDARY IS DUE SOUTH. EXPECT THE CT VALLEY TO BREAK
OUT INTO VFR HOWEVER EVERYWHERE ELSE SHOULD STAY SOCKED IN. VCTS
CONDITIONS ARE BEST FOR PVD/BAF/BDL AS TSRA ARE FIRING ACROSS THE
BOUNDARY.
TONIGHT...MVFR TO IFR CONDITIONS WILL DETERIORATE TO IFR/LIFR
OVERNIGHT. EASTERLY FLOW WILL SOCK THE EAST COAST IN LOW CLOUDS
AND FOG. LIFR CONDITIONS ARE BEST ACROSS THE CAPE.
WEDNESDAY...MAINLY MVFR/VFR CONDITIONS WITH BETTER CHANCE FOR
SHOWERS/TSTMS ESPECIALLY ORH HILLS WESTWARD.
WEDNESDAY NIGHT...MVFR TO IFR CONDITIONS OVERNIGHT AS SHRA AND
TSRA GROW IN COVERAGE OVERNIGHT ESP ACROSS WESTERN TERMINALS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS...LOWER IN TIMING
SPECIFICS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF TRENDS...LOWER IN
TIMING SPECIFICS. CONTINUED TO MENTION VCTS AS SHOWERS AND TSRA
CONTINUE TO DEVELOP ALONG BOUNDARY.
OUTLOOK...THURSDAY THROUGH SATURDAY...
MODERATE CONFIDENCE.
WEDNESDAY NIGHT AND THURSDAY...LOW CLOUDS/FOG PATCHES WILL LIKELY
RESULT IN SOME MVFR-IFR CONDITIONS ESPECIALLY ON THE SOUTHEAST NEW
ENGLAND COAST. IN ADDITION...LOWER CONDITIONS ARE ALSO EXPECTED IN
SCATTERED SHOWERS AND THUNDERSTORMS WED NIGHT AND THU. ACTIVITY
LOOKS MOST WIDESPREAD ON THURSDAY.
FRIDAY AND SATURDAY...A FEW LINGERING SHOWERS/THUNDERSTORMS POSSIBLE
ON FRIDAY. OTHERWISE...VFR CONDITIONS LIKELY DOMINATE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT TERM...MODERATE TO HIGH CONFIDENCE.
TODAY THROUGH WEDNESDAY...
WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT CRITERIA THROUGH
TONIGHT. AS WINDS SHIFT BACK TO S-SW AND PICK UP DURING WED
AFTERNOON...WITH GUSTS UP TO 20 KT...SEAS MAY BUILD BACK UP TO
AROUND 5 FT ON THE SOUTHERN WATERS. SMALL CRAFTS MAY BE NEEDED
THEN. EXPECT REDUCED VSBYS THROUGH LATE MORNING IN FOG...WITH
REDEVELOPMENT TONIGHT INTO WED MORNING.
THERE IS A LOW PROBABILITY FOR A CHANCE OF SHOWERS/TSTMS
THIS AFTERNOON/EVENING AS WELL.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
MODERATE CONFIDENCE.
WEDNESDAY NIGHT AND THURSDAY...
SOUTHWEST FLOW WILL CONTINUE OUT AHEAD OF A COLD FRONT. INVERSION
OVER THE WATER SHOULD KEEP SEAS A BIT LOWER THAN WNA GUIDANCE
SUGGESTS...BUT STILL MAY SEE SOME 5 FOOT SEAS ACROSS THE SOUTHERN
WATERS AS A RESULT OF THE LONG FETCH. NEAR SHORE WIND GUSTS TO
AROUND 25 KNOTS WILL ALSO BE POSSIBLE THURSDAY AFTERNOON ALONG THE
SOUTH COASTAL WATERS.
TWO OTHER CONCERNS WILL BE FOR AREAS OF DENSE FOG LATE WED NIGHT
INTO THU MORNING ACROSS THE SOUTHERN WATERS. THERE MAY ALSO BE A A
ROUND OR TWO OF THUNDERSTORMS ON THURSDAY.
FRIDAY AND SATURDAY...
HIGH PRESSURE WILL BUILD ACROSS THE WATERS. ANY LINGERING 5 FOOT
SEAS ACROSS THE SOUTHERN WATERS SHOULD DROP BELOW SCA FRIDAY NIGHT.
OTHERWISE...WINDS/SEAS SHOULD DROP BELOW SCA THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...DUNTEN
SHORT TERM...EVT
LONG TERM...FRANK
AVIATION...FRANK/DUNTEN
MARINE...FRANK/EVT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
152 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK FRONT ACROSS SOUTHERN CONNECTICUT WILL GRADUALLY RETURN
NORTH THIS AFTERNOON. A WEAK TROUGH APPROACHES WEDNESDAY
AFTERNOON...WITH A SLOWLY MOVING FRONTAL SYSTEM AFFECTING THE
REGION THROUGH THE END OF THE WEEK. A COLD FRONT SLOWLY MOVES
THROUGH THE REGION WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND
THEN STALLS OFFSHORE. HIGH PRESSURE THEN TRIES TO BUILD INTO THE
REGION FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STALLED OUT FRONTAL BOUNDARY ACROSS SOUTHERN CT SERVING AS A
TRIGGER IN AN UNCAPPED AIRMASS. THIS COMBINED WITH A LIGHT WEST
FLOW ALOFT IS RAISING THE FLOOD THREAT POTENTIAL ACROSS THIS AREA.
IN ADDITION...THERE IS SOME ISOLATED CONVECTION POPPING UP ALONG
THE SEABREEZE FRONT ON THE NORTH SHORE OF LI. BOTH AREAS WILL BE
MONITORED FOR FLOODING.
LATEST HRRR MODEL TAKES BOUNDARY SLOWLY NORTH THIS AFTERNOON ALONG
WITH THE CONVECTION. ADDITIONAL SCT CONVECTION WILL LIKELY FIRE UP
WITH AN APPROACHING SHORT WAVE TROF TO THE NORTH AND WEST OF
NYC...BEFORE DISSIPATING NEAR THE COAST EARLY THIS EVE. SEABREEZE
BOUNDARY IS ALSO ANOTHER POTENTIAL TRIGGER FOR CONVECTION. DUE TO
WEAK STEERING WINDS FROM THE WEST AT 10 KT OR LESS...ANY
CONVECTION WILL BE CAPABLE OF BRIEF HEAVY DOWNPOURS. WIND SHEAR IS
WEAK WHICH DOES NOT SUPPORT ORGANIZED SEVERE CONVECTION.
VERY WARM TEMPS CONTINUE WITH DEWPOINTS INCREASING A TAD AS COMPARED
TO YESTERDAY. HEAT INDICES ACROSS NYC METRO AND INTERIOR SHOULD
TOP OUT IN THE LOWER 90S ONCE AGAIN.
A MODERATE RISK FOR RIP CURRENTS EXISTS AT THE ATLANTIC OCEAN
BEACHES OF EASTERN LONG ISLAND TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
WEAK VORTS WILL CONTINUE TO ROTATE THROUGH THE REGION TONIGHT INTO
WEDNESDAY...AS A TROUGH DIGS INTO THE GREAT LAKES. AT THE
SURFACE...THE BACK DOOR FRONT WILL GRADUALLY PUSH NORTH TONIGHT INTO
WEDNESDAY. ON WEDNESDAY...A PRE-FRONTAL TROUGH WILL APPROACH THE
REGION IN THE AFTERNOON AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM
NEAR HUDSON BAY.
MAIN FOCUS FOR ANY SHRA/TSRA TONIGHT SHOULD BE NORTH OF THE REGION
WITH LLJ FORCING AND THE NORTHWARD MOVING FRONTAL BOUNDARY OVERNIGHT.
OTHERWISE...WITH DIMINISHING INSTABILITY THIS EVENING...WOULD
EXPECTED ANY CONVECTION TO GRADUALLY WEAKEN. AN ISOLATED SHRA/TSRA
IS POSSIBLE OVERNIGHT WITH INCREASING LLJ...MARGINAL
INSTABILITY...AND WEAK VORT ACTIVITY...BUT MAINLY DRY. INCREASINGLY
MOIST SOUTHERLY FLOW WILL BRING A POTENTIAL FOR PATCHY FOG AND
STRATUS OVERNIGHT.
POTENTIAL INCREASES FOR MORE WIDESPREAD CONVECTION ACROSS WESTERN
ZONES...BETWEEN APPROACHING PRE-FRONTAL TROUGH AND SEABREEZE
BOUNDARY...WEDNESDAY AFTERNOON WITH STRENGTHENING WIND FIELDS AND
APPROACHING SHORTWAVE. SEVERE POTENTIAL WILL BE PREDICATED BY
AMOUNT OF SUNSHINE...BUT WITH AN INCREASINGLY MOIST AIRMASS A
MODERATELY UNSTABLE AIRMASS IS QUITE POSSIBLE IN THE ABOVE
MENTIONED AREA. THE OTHER THREAT WILL BE FOR HEAVY RAIN AND
POTENTIAL FLASH FLOODING WITH TRAINING CELLS ALONG S/N ORIENTED
BOUNDARIES AS PWATS INCREASE TO AROUND 2" AND WARM CLOUD LAYER
INCREASES.
VERY WARM AND INCREASINGLY HUMID CONDITIONS ON WED...WITH TEMPS IN
THE MID TO UPPER 80S NYC/NJ METRO AND INTERIOR...WITH LOWER TO MID
80S ALONG THE COAST IN SOUTHERLY SYNOPTIC FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
UNSETTLED WEATHER ON TAP FOR THE MIDDLE TO THE END OF THE WEEK AS
LOW PRES TRACKING ACROSS EASTERN CANADA DRAGS A COLD THROUGH THE
REGION ON THURSDAY. THE FIRST ROUND OF SHOWERS AND POSSIBLE
THUNDERSTORMS WILL TAPER OFF IN THE FIRST HALF OF WEDNESDAY
NIGHT....AND THEN ADDITIONAL SHOWERS AND POSSIBLE THUNDERSTORMS WILL
DEVELOP ON THURSDAY AS WEAK LOW PRES DEVELOPS ALONG THE FRONT AND
SLIDES THROUGH THE REGION. WITH PWATS AROUND 2"...CAN EXPECT HEAVY
RAIN. SCATTERED TO NUMEROUS SHOWERS/TSTMS WILL IMPACT THE REGION
THROUGHOUT THE DAY...TAPERING OFF LATE.
BASED ON THE MODEST SW FLOW AND BUILDING SEAS...DANGEROUS RIPS
APPEAR LIKELY WED AND THU AT THE OCEAN.
COLD FRONT WILL BE THROUGH THE REGION THURSDAY NIGHT AND BECOMES
NEARLY STATIONARY EAST OF THE AREA. H5 TROUGH/SHORTWAVE MOVES RIGHT
OVER THE AREA ON FRIDAY AND THEN STALLS OUT OVER THE AREA. EVEN
THOUGH HIGH PRES BUILDS IN AT THE SFC...WILL HAVE TO KEEP AT LEAST
CHANCE POPS IN THE FORECAST FOR THE WEEKEND DUE TO THIS UPPER LEVEL
SYSTEM OVER THE AREA.
RETURN FLOW SETS UP BRINGING AN INCREASE IN THE HEAT AND HUMIDITY
AGAIN ON MON.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR FORECAST INTO THIS EVENING FOR ALL SITES EXCEPT KGON.
CONVECTION DEVELOPING...ISOLATED TO SCATTERED CONVECTION IS
WILL PERSIST THIS AFTERNOON THROUGH 12Z WEDNESDAY...BUT
CONFIDENCE IN EXACT TIMING/LOCATION NOT HIGH ENOUGH TO INCLUDE IN
TAFS. VSBYS MAY DROP TO MVFR AFTER MIDNIGHT /LOW
CONFIDENCE/...THEN LIFT AROUND 13Z WEDNESDAY. FIRST NIGHT OF
SOUTHERLY FLOW /AS OPPOSED TO SOUTHWESTERLY/...SO MVFR CIGS ARE NOT
EXPECTED...BUT WILL MONITOR TRENDS. EXCEPTION IS AT KGON WHERE IFR
CIGS/VSBYS ARE FORECAST BETWEEN 09 AND 14Z WEDNESDAY...WITH MVFR
CIGS/VSBYS FORECAST ON EITHER SIDE OF THAT. OCCASIONAL LIFR
POSSIBLE AT KGON AROUND 12Z...BUT LOW CONFIDENCE.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: BEST CHANCE OF TSTMS AFTER 20Z. ANY TSTMS
NEAR TERMINAL COULD CAUSE WINDS TO GO VRB BRIEFLY.
KJFK FCSTER COMMENTS: BEST CHANCE OF TSTMS AFTER 20Z. ANY TSTMS
NEAR TERMINAL COULD CAUSE WINDS TO GO VRB BRIEFLY.
KLGA FCSTER COMMENTS: BEST CHANCE OF TSTMS AFTER 20Z. ANY TSTMS
NEAR TERMINAL COULD CAUSE WINDS TO GO VRB BRIEFLY.
KTEB FCSTER COMMENTS: BEST CHANCE OF TSTMS AFTER 20Z. ANY TSTMS
NEAR TERMINAL COULD CAUSE WINDS TO GO VRB BRIEFLY.
KHPN FCSTER COMMENTS: BEST CHANCE OF TSTMS AFTER 20Z. ANY TSTMS
NEAR TERMINAL COULD CAUSE WINDS TO GO VRB BRIEFLY.
KISP FCSTER COMMENTS: CONVECTION THROUGH 19Z. ADDITIONAL TSTMS
POSSIBLE AFTER 19Z. ANY TSTMS NEAR TERMINAL COULD CAUSE WINDS TO
GO VRB BRIEFLY.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUN...
.THU-FRI...SUB VFR FOG/CIGS POSSIBLE DAILY 06Z-14Z. SCT TSTMS
POSSIBLE DAILY MAINLY 18Z-04Z WITH SUB VFR POSSIBLE AT TIMES.
.SAT...SUB VFR POSSIBLE IN SHOWERS.
.SUN...VFR.
&&
.MARINE...
SUB SCA CONDS THROUGH TONIGHT WITH GENERAL SW WINDS EXPECTED.
WINDS ARE EXPECTED TO GRADUALLY INCREASE ON WEDNESDAY AHEAD OF AN
APPROACHING PRE-FRONTAL TROUGH. THERE IS POTENTIAL FOR MARGINAL
SCA WINDS ACROSS WESTERN OCEAN WATERS INTO ENTRANCE OF NYC HARBOR
LATE WED WITH COASTAL JET.
SOUTHERLY FLOW INCREASES ON WEDNESDAY AHEAD OF A SLOWLY MOVING COLD
FRONT. THIS WILL BUILD SEAS ON THE OCEAN TO SCA LEVELS BY WEDNESDAY
NIGHT...AND SCA CONDITIONS WILL CONTINUE THROUGH THURSDAY. OUTSIDE
OF THE S SHORE BAYS...WHERE WINDS MAY REACH SCA LEVELS...THE
REMAINING WATERS SHOULD REMAIN BELOW SCA LEVELS. HIGH PRES THEN
BUILDS NORTH OF THE WATERS FRIDAY THROUGH THE WEEKEND. CONDITIONS
ARE THEREFORE EXPECTED TO REMAIN BELOW SCA LEVELS.
&&
.HYDROLOGY...
SCATTERED SHOWERS/THUNDERSTORMS WILL PRODUCE LOCALLY HEAVY RAIN
THIS AFTERNOON. AN ISOLATED FLASH FLOOD THREAT EXISTS WITH ANY
TRAINING CONVECTION...MAINLY ALONG THE WESTERN SEABREEZE BOUNDARY
AND/OR BACKDOOR COLD FRONT.
THE FLASH FLOOD THREAT SHOULD INCREASE A BIT ON WEDNESDAY
AFTERNOON ACROSS WESTERN PORTIONS OF THE AREA...AS HEAVY RAIN
ENVIRONMENT BECOMES INCREASINGLY FAVORABLE AND CONVECTIVE COVERAGE
IS EXPECTED TO INCREASE BETWEEN AN APPROACHING PRE-FRONTAL TROUGH
AND SEABREEZE BOUNDARY. THE THREAT FOR FLASH FLOODING WILL EXIST
IN THE PATH OF ANY TRAINING THUNDERSTORMS.
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL
WEDNESDAY THROUGH THURSDAY NIGHT ACROSS THE HSA. ALTHOUGH WIDESPREAD
FLOODING IS NOT EXPECTED AT THIS TIME...FLASH FLOODING IS POSSIBLE
WITH ANY TRAINING CONVECTION.
RAINFALL IN EXCESS OF 2 INCHES IS POSSIBLE IN AN AREA IF
THUNDERSTORMS TRAIN OVER THAT AREA FOR AN HOUR.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
325 PM EDT TUE JUL 9 2013
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UNAMPLIFIED UPPER LEVEL
PATTERN WITH THE MAIN NORTHERN STREAM FLOW ALIGNED ZONALLY OVER THE
U.S/CANADIAN BORDER. TO THE SOUTH OF THE NORTHERN STREAM WE FIND A
BROAD EXPANSE OF UPPER LEVEL RIDGING IN PLACE ACROSS MUCH OF THE
SOUTHERN TIER OF THE CONUS. ONE OTHER FEATURE OF NOTE IS A TUTT
FEATURE/UPPER LOW SLOWLY MIGRATING WESTWARD FROM THE BAHAMAS TOWARD
THE SOUTHERN FL PENINSULA. THIS TUTT FEATURE MAY BRING SOME ENHANCED
RAIN CHANCES TO THE AREA ON WEDNESDAY...ESPECIALLY FOR THE SOUTHERN
HALF OF THE PENINSULA...BUT OVERALL WILL BE IN A WEAKENING PHASE IN
TERMS OF ITS NEGATIVE THERMAL ANOMALY...AND THIS SHOULD LIMIT THE
OVERALL POSITIVE INSTABILITY IMPACT THAT TUTT CELLS CAN HAVE TOWARD
DIURNAL CONVECTION THIS TIME OF YEAR.
AT THE SURFACE...HIGH PRESSURE IS ALIGNED FROM OFF THE GA/SC COAST
WESTWARD ALONG OR JUST NORTH OF THE I-10 CORRIDOR. WE FIND OUR
FORECAST AREA SITUATED BETWEEN THIS RIDGE AXIS AND A WEAK INVERTED
TROUGH ALONG THE FL SE COAST. THIS TROUGH IS REALLY JUST THE SURFACE
REFLECTION OF THE TUTT...AND IS PROGGED BY THE LATEST NAM/GFS AND
LOCAL HI-RES MODELS TO MIGRATE IN ADVANCE OF THE UPPER LEVEL FEATURE
ACROSS TO THE SOUTHWEST PENINSULA COAST BY THIS EVENING. THE ADDED
LOW LEVEL FOCUS ASSOCIATED WITH THIS WEAK TROUGH MAY HELP TO ENHANCE
THE DIURNAL THUNDERSTORM ACTIVITY FOR OUR SOUTHERN COASTAL ZONES
LATER THIS AFTERNOON.
.SHORT TERM (TONIGHT THROUGH THURSDAY)...
REST OF THE AFTERNOON THROUGH MID EVENING...
12Z KTBW SOUNDING WAS A BIT ON THE DRY SIDE...AND WOULD NOT BE AN
UNFAVORABLE PROFILE TO SUPPORT A FEW WET-MICROBURSTS WITH ANY
STRONGER LATE DAY STORMS. HOWEVER...NUMERICAL GUIDANCE DOES INDICATE
THAT DRIEST OF THE MID-LEVEL AIR WILL MODIFY SOMEWHAT BY THIS
EVENING AND DECREASE THIS THETA-E DIFFERENCE FROM THE SURFACE. THE
BEST POSITIVE MOISTURE ADVECTION WILL CERTAINLY BE DOWN TOWARD FT.
MYERS. THE NET RESULT OF THIS WOULD LIKELY TO FURTHER ENHANCE THE
STORM COVERAGE SOUTH OF TAMPA BAY...BUT LIMIT THE POTENTIAL WIND
IMPACTS FROM ANY STRONGER STORMS. FROM TAMPA BAY NORTHWARD...THE
DRIER COLUMN SHOULD KEEP THE ACTIVITY MORE SCATTERED...BUT ANY
STRONGER STORMS WILL NEED TO BE WATCHED CLOSELY FOR STRONG WIND
GUST POTENTIAL.
TONIGHT...
LINGERING EVENING STORMS WILL SHIFT OFFSHORE AND WEAKEN DURING THE
MID/LATE EVENING HOURS. THE WEAK UPPER LEVEL SUPPORT FROM THE TUTT
IS LIKELY TO AID ANY TYPICAL NOCTURNAL LAND BREEZE CONVECTION OVER
THE WATER. HAVE INCREASED POPS AFTER MIDNIGHT AWAY FROM THE COAST
INTO THE CHANCE 30-40% RANGE. JUST SOMETHING TO KEEP IN MIND FOR
THOSE PLANNING TO BOAT EARLY IN THE MORNING.
WEDNESDAY/WEDNESDAY NIGHT...
TUTT CELL WILL STALL NEAR THE FLORIDA WEST COAST AND SLOWLY
DISSIPATE. NOT EXPECTING ANY SIGNIFICANT IMPACTS FOR THIS FEATURE
OTHER THAN SOME SLIGHT INCREASE IN COLUMN MOISTURE AND WEAK CYCLONIC
FLOW ALOFT. COVERAGE OF SHOWERS AND STORMS IS LIKELY TO BE HIGHER ON
A REGION-WIDE SCALE DURING THE AFTERNOON HOURS TOMORROW AS A RESULT
OF THESE FACTORS...BUT OVERALL NOT AN OVERLY UNUSUAL WEATHER
SITUATION FROM WHAT WOULD BE EXPECTED FOR JULY.
THURSDAY/THURSDAY NIGHT...
UPPER PATTERN WILL BEGIN TO AMPLIFY ACROSS THE EASTERN STATES. THE
FL PENINSULA WILL BE ON THE BASE OF THIS TROUGH WITH ONLY LIMITED
SYNOPTIC INFLUENCE. ONCE AGAIN RAIN COVERAGE WILL LIKELY BE FAIRLY
HIGH ON THURSDAY AFTERNOON/EVENING...ALTHOUGH SIMILAR TO
WEDNESDAY...THE TEMPORAL LENGTH OF RAINFALL AT ANY ONE LOCATION WILL
LIKELY NOT BE THAT GREAT.
&&
.LONG TERM (THURSDAY NIGHT-TUESDAY)...
TROPICAL STORM CHANTAL REMAINS THE MAIN FORECAST CHALLENGE THROUGH
THE LONG TERM PERIODS. THE LATEST FORECAST FROM THE NATIONAL
HURRICANE CENTER CONTINUES TO SHOW THE SYSTEM MOVING NORTHWESTWARD
THROUGH THE BAHAMAS LATE IN THE WEEK AND OVER THE UPCOMING
WEEKEND. MODEL SOLUTIONS OFFER A VARIETY OF SOLUTIONS WITH THE 00Z
GFS SHOWING THE SYSTEM TAKING A WESTWARD TRACK ACROSS CENTRAL
FLORIDA EARLY NEXT WEEK...THE 00Z CANADIAN SHOWING A WELL DEFINED
SYSTEM MAKING LANDFALL ACROSS SOUTHEAST GEORGIA OR SOUTHERN SOUTH
CAROLINA LATE IN THE WEEKEND...WHILE THE 00Z ECMWF SHOWS NOTHING
MORE THAN SOME UPPER LEVEL ENERGY SHEARING OUT OFF THE EAST COAST
OF FLORIDA OVER THE UPCOMING WEEKEND. GIVEN THE FORECAST TRACK
TAKING CHANTAL OVER THE HIGHER TERRAIN OF HISPANIOLA...WOULD NOT
EXPECT A VERY STRONG SYSTEM TO EMERGE BACK OVER THE ATLANTIC LATE
IN THE WEEK AND OVER THE UPCOMING WEEKEND...SO WILL TRY TO
MAINTAIN AS MUCH FORECAST CONTINUITY AS POSSIBLE AND LEAN THE
FORECAST HEAVILY IN THE DIRECTION OF THE 00Z ECMWF. AS A
RESULT...WILL CONTINUE TO HIGHLIGHT A MORE TYPICAL SUMMERTIME
REGIME WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY AND
TEMPERATURES REMAINING CLOSE TO CLIMATOLOGY.
&&
.AVIATION...
ANTICIPATE SCT TSRA THIS AFTERNOON...WITH LCL MFR/LIFR PGD/FMY/RSW.
TSRA REACHING LAL/TPA/PIE/SRQ WILL BE LATER AND PERHAPS MORE
LIMITED...HAVE OPTED TO HOLD AT VCTS. EAST AND SE WINDS...GUSTY NEAR
TSRA...SHIFTING TO ONSHORE THIS AFTERNOON AT TPA/PIE/SRQ.
&&
.MARINE...
A WEAK PRESSURE GRADIENT WILL REMAIN ACROSS MUCH OF THE EASTERN GULF
OF MEXICO THROUGH THURSDAY KEEPING WINDS AND SEAS BELOW HEADLINE
CRITERIA OUTSIDE OF A TYPICAL DISTRIBUTION OF SHOWERS AND STORMS.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS EXPECTED THROUGH MIDWEEK AS
RELATIVE HUMIDITY VALUES REMAIN WELL ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 90 76 90 / 30 50 30 50
FMY 72 92 73 91 / 30 50 30 50
GIF 72 92 73 92 / 10 50 20 50
SRQ 73 89 74 89 / 30 50 30 50
BKV 69 92 71 91 / 20 50 30 50
SPG 78 90 77 89 / 30 40 30 50
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
215 PM CDT TUE JUL 9 2013
.DISCUSSION...
ISSUED 200 PM CDT TUE JUL 9 2013
BAND OF CONVECTION THAT FIRED EARLY THIS MORNING ACROSS IOWA HAS
PUSHED EAST INTO NORTH CENTRAL IL JUST AHEAD OF A MID LEVEL
SHORTWAVE. UPSTREAM FROM THAT WAVE IS A MORE SIGNIFICANT SHORTWAVE
OVER NORTH DAKOTA THAT WILL BRING AN END TO THE HEAT AND HUMIDITY
ALONG WITH THE THREAT FOR RAIN. AT THE SURFACE...THE 18Z ANALYSIS
INDICATES A WEAK OUTFLOW BOUNDARY FROM THE MORNING CONVECTION LOCATED
FROM JUST WEST OF LACON AND EAST OF PEORIA AND SPRINGFIELD. THERE
WAS A MIX OF SUN AND CLOUDS EARLY THIS AFTERNOON WITH TEMPERATURES
CURRENTLY RANGING FROM THE UPPER 80S TO LOWER 90S WITH HEAT INDEX
VALUES AROUND 100.
SHORT TERM...TONIGHT THROUGH FRIDAY
SEVERE STORM THREAT TONIGHT THE MAIN FORECAST CHALLENGE. WILL FOLLOW
THE HRRR AND THE NCEP HI-RES ARW MODELS AS THEY HAVE SHOW A BIT MORE
CONSISTENCY WITH THE DEVELOPMENT OF CONVECTION LATER THIS AFTERNOON
AND ESPECIALLY TONIGHT ALONG THE SOUTHEASTWARD MOVING COLD FRONT.
WILL GRADUALLY PROGRESS THE HIGHEST POPS FROM NW TO SE OVERNIGHT AS
THE COLD FRONT SETTLES INTO THE REGION. FORECAST SOUNDINGS STILL CONTINUE
TO SHOW AN INCREASE IN MID LEVEL WINDS CONINCIDENT WITH HIGH CAPE VALUES
TONIGHT IN ADVANCE OF THE STRONGER UPPER LEVEL FORCING. AS A RESULT...A
FEW OF THE STORMS WILL BE CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND
TORRENTIAL RAINFALL WITH PRECIP WATER VALUES AROUND 2 INCHES. ASSUMING
ORGANIZED CONVECTION DOES DEVELOP TO OUR NORTHWEST THIS EVENING...THE
EFFECTIVE OUTFLOW BOUNDARY SHOULD BE PRESSING SE INTO THE I-70 CORRIDOR
BY MORNING WITH THE ACTUAL SYNOPTIC COLD FRONT LAGGING BEHIND.
POPS WILL LOWER FROM NW TO SE TOMORROW MORNING IN ANTICIPATION OF
THE COLD FRONT SLIPPING SE OF I-70 BY 21Z. MAIN QUESTION IS WHETHER
ANY STORMS CAN REFIRE AHEAD OF THE FRONT TOMORROW AFTN. IF WE SEE
VERY LITTLE ACTIVITY TONIGHT...CHANCES ARE WE WILL SEE STORMS REFIRE
AHEAD OF THE COLD FRONT ALONG THE I-70 CORRIDOR BEFORE SHIFTING OFF
TO OUR SOUTHEAST BY EVENING. IF STORMS DO ORGANIZE...AND TRACK QUICKLY
SE LATE TONIGHT...WE MAY NOT SEE ANY DEVELOPMENT ACRS THE SOUTHEAST
TOMORROW AFTN. STILL SOME UNCERTAINTY WITH RESPECT TO FRONTAL POSITION
ACRS SE IL SO WILL CONTINUE TO KEEP POPS GOING DOWN THERE THRU THE
AFTN HOURS.
PACIFIC HIGH PRESSURE WILL THEN BUILD EAST INTO THE MIDWEST BRINGING
IN COOLER AND LESS HUMID AIR STARTING WEDNESDAY NIGHT AND CONTINUING
THRU THE REST OF THE WORK WEEK. ONE MORE HOT AND HUMID DAY FOR THE
SOUTHEAST WITH TEMPERATURES RISING INTO THE LOWER 90S WITH HEAT INDEX
VALUES AT OR JUST ABOVE 100. AFTER THAT... WE SHOULD AFTERNOON TEMPS
DROP BACK INTO THE LOW TO MID 80S AND SURFACE DEW POINTS BACK TO THE
UPPER 50S TO LOWER 60S THURSDAY AND ESPECIALLY ON FRIDAY.
LONG TERM...SATURDAY THROUGH TUESDAY
UPPER LEVEL RIDGING STILL FORECAST TO BUILD OVER THE CENTER OF THE
NATION DURING THIS PERIOD BRINGING RELATIVELY QUIET WEATHER TO OUR
AREA. STRONGER MID LEVEL FLOW WILL SHIFT WELL TO OUR NORTH WITH
TEMERATURES RISING BACK INTO THE UPPER 80S TO AROUND 90 BY SUNDAY
AND MONDAY.
SMITH
&&
.AVIATION...
ISSUED 1245 PM CDT TUE JUL 9 2013
SATELLITE IMAGERY SHOWS SOME BREAKUP OF THE CLOUDS OVER CENTRAL IL
LAST FEW HOURS...AS THE MUCAPES HAVE REACHED TO 3000. SURFACE DATA
HAS SHOWN SOME BOUNDARY INTERACTION IN THE REGION MAY LATER
TRIGGER CONVECTION. MOST OF CLOUDINESS OVER REGION IS MID WITH
SPOTTY SCT LOW CLOUDS. KEPT TREND OF VCNTY PCPN UNTIL MAIN FRONTAL
ACTIVITY APPROACHS OVERNIGHT. OVERALL...FEW CHANGES.
GOETSCH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
123 PM CDT TUE JUL 9 2013
.DISCUSSION...
1144 AM CDT
FOR MORNING UPDATE...
NO SIGNIFICANT CHANGES TO GOING FORECAST FOR THE MOST PART OTHER
THAN REFINING POPS/WX AND TIMING OF WAVES OF SHOWERS/STORMS.
AN AREA OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD EAST
ACROSS THE AREA THROUGH MIDDAY AHEAD OF A MID-LEVEL SHORT WAVE
TROUGH APPROACHING THE MID/UPPER MISSISSIPPI VALLEY. AS EXPECTED...
RELATIVELY WEAK MID/UPPER LEVEL FLOW RESULTING IN WEAK BULK SHEAR
MAGNITUDE...WITH LOOSELY ORGANIZED MCS PRESENTING MAINLY A LOCALLY
HEAVY RAIN THREAT GIVEN PWATS AROUND 2.00 INCHES.
THROUGH THIS AFTERNOON...MID-LEVEL TROUGH IS PROGGED TO MOVE EAST
ACROSS IL/WI...WITH ENHANCED VORTICITY/MCV OVER CENTRAL IA EXPECTED
TO HELP MAINTAIN AREA OF STORMS CURRENTLY OVER EASTERN/SOUTHEAST IA.
DESPITE IMPACT OF CLOUDS/SCATTERED PRECIP COVERAGE...THE COMBINATION
OF INCREASING MID-LEVEL FLOW AND DEEP SHEAR ALONG WITH DIURNAL
DESTABILIZATION IN WARM/MOIST AIR MASS WILL LIKELY RESULT IN AN
INCREASED COVERAGE AND ORGANIZATION TO STORMS DURING LATE AFTERNOON
AND EARLY EVENING HOURS...INCREASING SEVERE THREAT ALONG WITH
ONGOING HEAVY RAINFALL POTENTIAL. RECENT RUNS OF RAP/HRRR SEEM TO
HAVE A DECENT OVERALL HANDLE ON CURRENT ACTIVITY...AND SUPPORT THE
IDEA OF THE LINE OVER EASTERN IA MOVING ACROSS THE AREA FROM
MID-AFTERNOON INTO EARLY THIS EVENING.
RATZER
//PREV DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ANOTHER WINDOW FOR SHRA/TSRA MID/LATE AFTERNOON.
* LOW CHANCE FOR SOME ADDITIONAL SHRA/TSRA OVERNIGHT.
* WINDS TURNING WEST TONIGHT THEN NORTHWEST WEDNESDAY MORNING.
MDB
//DISCUSSION...UPDATED 18Z...
FOCUS REMAINS ON SHRA/TSRA POTENTIAL THROUGH THE AFTERNOON. AN
INITIAL ROUND OF SHRA/TSRA IS NOW CLEARING THE CHICAGO AREA
TERMINALS. ANOTHER BAND OF SHRA AND EMBEDDED TSRA IS STRETCHED
FROM RFD BACK TO FSW HAD BEEN BETTER ORGANIZED EARLIER IN THE DAY
BUT HAS BEGUN TO WANE OVER THE LAST HOUR. THIS AREA IS OUT AHEAD
OF AN UPPER TROUGH MOVING EASTWARD ACROSS EASTERN IOWA. A MORE
FAVORABLE AIRMASS IS IN PLACE ACROSS WEST CENTRAL ILLINOIS AND IT
MAY BE THAT DEVELOPMENT INCREASES IN THIS AREA WHICH MAY LARGELY
STAY SOUTH OF THE TERMINALS. HOWEVER...WITH SHRA/TSRA STILL ON
RADAR WILL CONTINUE TO BRING IT ACROSS THE TERMINALS THROUGH
MID/LATE AFTERNOON AND THERE IS STILL SOME POTENTIAL FOR RENEWED
DEVELOPMENT AS THE UPPER TROUGH APPROACHES. TOUGH CALL AND MAY
NEED TO DOWNPLAY THE POTENTIAL SLIGHTLY IN THE NEXT FEW HOURS.
ONCE THE WAVE PASSES LATE THIS AFTERNOON THERE LOOKS TO BE LITTLE
FOCUS FOR NEW DEVELOPMENT THROUGH THE EVENING SO WILL KEEP THE
TAFS DRY THOUGH A LOW CHANCE DOES EXIST FOR SOME SPOTTY
DEVELOPMENT GIVEN THE UNSTABLE AIRMASS. ANOTHER WAVE CROSSES THE
AREA OVERNIGHT BUT THE LOW AND MID LEVELS WILL BE DRIER SO CHANCES
FOR SHRA/TSRA WILL BE LOW. WINDS OVER THE NEXT FEW HOURS WILL
LIKELY BE SOMEWHAT VARIABLE BETWEEN SOUTH AND WEST THANKS TO THE
SHRA/TSRA BUT EXPECT THAT ONCE THE CURRENT ACTIVITY EXITS THE
CHICAGO/NW INDIANA AREA WINDS WILL TURN MORE SOUTHERLY BEFORE
GOING BACK TO WEST-SOUTHWEST LATER TODAY. A FRONT WILL CROSS THE
AREA WEDNESDAY MORNING SHIFTING WINDS TO THE NORTHWEST. SOME MVFR
STRATOCU IS EXPECTED DURING THE MORNING BUT WOULD LIKELY LIFT TO
VFR AND DIMINISH IN COVERAGE INTO THE AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN AT LEAST SOME SHRA/TSRA AFFECTING THE
TERMINALS MID/LATE AFTERNOON...MEDIUM-HIGH CONFIDENCE IN TIMING
...LOW-MEDIUM CONFIDENCE IN COVERAGE.
* MEDIUM CONFIDENCE THAT SHRA/TSRA POTENTIAL OVERNIGHT IS LOW.
* HIGH CONFIDENCE IN OVERALL WIND TRENDS BUT COULD BE BRIEFLY
AFFECTED BY ANY SHRA/TSRA ACTIVITY.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1145 AM CDT TUE JUL 9 2013
.DISCUSSION...
1144 AM CDT
FOR MORNING UPDATE...
NO SIGNIFICANT CHANGES TO GOING FORECAST FOR THE MOST PART OTHER
THAN REFINING POPS/WX AND TIMING OF WAVES OF SHOWERS/STORMS.
AN AREA OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SPREAD EAST
ACROSS THE AREA THROUGH MIDDAY AHEAD OF A MID-LEVEL SHORT WAVE
TROUGH APPROACHING THE MID/UPPER MISSISSIPPI VALLEY. AS EXPECTED...
RELATIVELY WEAK MID/UPPER LEVEL FLOW RESULTING IN WEAK BULK SHEAR
MAGNITUDE...WITH LOOSELY ORGANIZED MCS PRESENTING MAINLY A LOCALLY
HEAVY RAIN THREAT GIVEN PWATS AROUND 2.00 INCHES.
THROUGH THIS AFTERNOON...MID-LEVEL TROUGH IS PROGGED TO MOVE EAST
ACROSS IL/WI...WITH ENHANCED VORTICITY/MCV OVER CENTRAL IA EXPECTED
TO HELP MAINTAIN AREA OF STORMS CURRENTLY OVER EASTERN/SOUTHEAST IA.
DESPITE IMPACT OF CLOUDS/SCATTERED PRECIP COVERAGE...THE COMBINATION
OF INCREASING MID-LEVEL FLOW AND DEEP SHEAR ALONG WITH DIURNAL
DESTABILIZATION IN WARM/MOIST AIR MASS WILL LIKELY RESULT IN AN
INCREASED COVERAGE AND ORGANIZATION TO STORMS DURING LATE AFTERNOON
AND EARLY EVENING HOURS...INCREASING SEVERE THREAT ALONG WITH
ONGOING HEAVY RAINFALL POTENTIAL. RECENT RUNS OF RAP/HRRR SEEM TO
HAVE A DECENT OVERALL HANDLE ON CURRENT ACTIVITY...AND SUPPORT THE
IDEA OF THE LINE OVER EASTERN IA MOVING ACROSS THE AREA FROM
MID-AFTERNOON INTO EARLY THIS EVENING.
RATZER
&&
.PREV DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* ONE BAND OF SCATTERED TSRA EXPECTED BETWEEN 17-19Z...VERY BRIEF
IFR VSBY POSSIBLE.
* NEXT ROUND OF TSRA EXPECTED LATE TOWARD 20/21Z FROM THE
WEST...BETTER ORGANIZATION AND LOWER VSBY IS MORE LIKELY WITH
THIS ROUND.
* SOME CHANCE OF ADDITIONAL SHRA/TSRA LATE TONIGHT OR EARLY
WEDNESDAY MORNING.
MDB
//DISCUSSION...UPDATED 16Z...
CONVECTIVE POTENTIAL STARTING TO BECOME A BIT MORE CLEAR. ONE
CLUSTER OF SHRA/TSRA CONTINUES TO APPROACH FROM THE WEST WITH
FLUCTUATIONS IN INTENSITY AND COVERAGE. INDIVIDUAL TS CELLS ARE
PRETTY SMALL BUT CONTINUE TO POP SO WILL CARRY VCTS AND A PERIOD
OF TEMPO TS AT THE TERMINALS OVER THE NEXT FEW HOURS...THOUGH
COVERAGE MAY BEGIN TO WANE. VERY BRIEF IFR VSBY IS POSSIBLE UNDER
THE HEAVIER CELLS. THE NEXT ROUND OF STORMS IS TAKING SHAPE ACROSS
EASTERN AND SOUTH CENTRAL IOWA WHICH WOULD ARRIVE IN THE AREA MID
TO LATE AFTERNOON. THERE SHOULD BE SHORT BREAK IN TS BEHIND THE
INITIAL AREA BEFORE THIS NEXT AREA ARRIVES. THIS SECOND AREA WILL
LIKELY BE MORE WIDESPREAD IN COVERAGE WITH LONGER PERIODS OF LOW
VISIBILITY POSSIBLE...ALONG WITH THE POTENTIAL FOR GUSTY WINDS.
THIS ALSO POINTS TO THE EVENING HOURS BEING QUIET SO WILL NEED TO
RE-EVALUATE SHRA/TSRA MENTION THEN.
MDB
FROM 12Z...
RELATIVELY QUIET ACROSS THE TERMINALS THIS MORNING WHILE SOME
FOG/HAZE REMAINS OVERHEAD...BUT WITH THE MORE DENSE FOG REMAINING
AWAY FROM THE TERMINALS AT THIS TIME. ANY FOG THIS MORNING SHOULD
QUICKLY DISSIPATE OVER THE NEXT HOUR WITH ANY THREAT OF LOWER
VIS/CEILINGS COMING SOUTH DOWN THE LAKE REMAINING LOW AT THIS
TIME. ALTHOUGH THIS AREA IS STILL SLOWLY MOVING SOUTH DOWN THE
LAKE...VEERING WINDS AND SHOULD HELP LIMIT THIS SOUTHWARD MOMENTUM
KEEPING THIS FOG NORTH OF THE TERMINALS. THEN SHIFT GEARS TO
REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING...AS PRECIP
DEVELOPS OUT AHEAD OF AN APPROACHING MID LEVEL DISTURBANCE. AS
THIS DISTURBANCE DRAWS NEAR...EXPECT CURRENT THUNDERSTORMS OVER
IOWA AS WELL AS OTHER DEVELOPMENT TO MOVE ACROSS THROUGH NORTHERN
ILLINOIS/NORTHWEST INDIANA BY MID DAY WITH SOME UPWARD GROWTH IN
COVERAGE AND INTENSITY EXPECTED INTO THE EARLY AFTERNOON. DO
EXPECT A BRIEF LULL IN THE ACTIVITY AFTER THIS INITIAL PRECIP
MOVES THROUGH...BUT WITH DEVELOPMENT STILL POSSIBLE GOING INTO THE
EARLY EVENING. STILL MONITORING THE POTENTIAL FOR A MORE
WIDESPREAD AREA OF THUNDERSTORMS TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT. ALTHOUGH IT STILL SEEMS
FAVORABLE FOR THIS TO MOVE ACROSS THE TERMINALS...WILL NEED TO
MONITOR LATER TRENDS AFTER THIS INITIAL PRECIP THIS AFTERNOON
MOVES THROUGH.
WINDS REMAIN LIGHT/VARIABLE THIS MORNING BUT ANTICIPATE A TREND
TOWARDS AN EAST NORTHEAST WIND OVER THE NEXT SEVERAL HOURS. WINDS
ALONG THE LAKE ARE ALREADY THIS EASTERLY COMPONENT AND WITH THE
SUN RISING COINCIDING WITH A WEAK GRADIENT...FEEL THAT IT WONT
TAKE MUCH FOR THIS NORTHEAST WIND TO DEVELOP OVER ORD/MDW/GYY THIS
MORNING. THEN EXPECT A SLOW TREND TOWARDS THE SOUTHEAST AND
EVENTUALLY SOUTH THIS AFTERNOON/EVENING...BEFORE WINDS CONTINUE TO
VEER TO THE WEST OVERNIGHT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN BAND OF SHRA/TSRA 17-19Z...MAY BE FAIRLY
SCATTERED THOUGH...HIGH CONFIDENCE THAT ANY IFR VSBY WOULD BE BRIEF.
* MEDIUM-HIGH CONFIDENCE IN ADDITIONAL ACTIVITY ARRIVING LATER
THIS AFTERNOON AND IT WOULD BE MORE WIDESPREAD AND
INTENSE...MEDIUM CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN POTENTIAL FOR ADDITIONAL ACTIVITY
TONIGHT/WEDNESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1115 AM CDT TUE JUL 9 2013
.DISCUSSION...
340 AM CDT
SEVERE WEATHER AND HEAVY RAIN POTENTIAL THROUGH TONIGHT WAS WHAT
MUCH OF THE ANALYSIS TIME WAS SPENT ON THIS MORNING. WHAT MAINLY
WAS TRYING TO DO WAS LOCK DOWN A TIMING FOR AN IMPROVED SEVERE
WEATHER THREAT /MID-AFTERNOON THROUGH EARLY OVERNIGHT THOUGH AIR
MASS CAN ALLOW FOR ISOLATED SEVERE ANYTIME/...AND WHAT MAIN
THREATS WOULD BE /WIND AND HEAVY RAIN/. OVERALL NO MAJOR CHANGES
MADE TO THE FORECAST...JUST INCREASING POPS IN THOSE MOST FAVORED
TIMES...RE-ORIENTING POPS SOME...AND REFINING RAINFALL AMOUNT
FORECASTS.
SYNOPSIS...A VERY SOUPY AIR MASS IS ENTRENCHED IN THE REGION
THIS MORNING WITH MID 70S DEW POINTS ACROSS THE FORECAST AREA AND
PWATS ON LAST EVES REGIONAL RAOBS AND EARLY MORNING OBJECTIVE
ANALYSIS BEING AROUND 2 INCHES. NUMEROUS SHORT WAVE IMPULSES...MANY
WITH ASSOCIATED CLUSTERS OF CONVECTION...ARE FOUND UPSTREAM ACROSS
THE HIGH PLAINS AND OVER THE WESTERN CORN BELT ON GOES WATER VAPOR
IMAGERY. THE PRIMARY UPPER LEVEL SHORT WAVE TROUGH WILL BE
DIGGING INTO EASTERN MT SOON AFTER DAYBREAK AND WILL BE THE
RESPONSIBLE PARTY FOR ENDING THIS MOIST AIR MASS...AT LEAST
TEMPORARILY BY LATER WED. AT THE SURFACE A FAIRLY DIFFUSE
GRADIENT EXISTS EARLY TODAY WITH A WEAK STATIONARY BOUNDARY NEAR
THE STATE LINE. THE WEAK FLOW HAS ALLOWED FOR LOW CLOUDS AND FOG
TO BE EXPANDING THEIR WAY SOUTHWARD DOWN LAKE MI AIDED BY AMBIENT
DEW POINTS EXCEEDING THE WATER TEMPS BY SEVERAL DEGREES. THE
PRIMARY SURFACE FRONT IS TAKING SHAPE ACROSS THE HIGH PLAINS AND
WILL DEVELOP INTO A COOL FRONT LATER TODAY AS SURFACE CYCLOGENESIS
OCCURS THROUGH NORTHERN MN INTO WESTERN ONTARIO BY THIS EVE. THIS
FRONT WILL MOVE INTO THE FORECAST AREA LATE TONIGHT INTO EARLY WED
MORNING. MULTIPLE ROUNDS OF CONVECTION ARE LIKELY AHEAD OF THIS.
MODEL PREFERENCE...THE RAP AND HRRR GUIDANCE HAVE A GOOD
REPRESENTATION OF ONGOING CONVECTION. THESE HAVE THE SUPPORT OF
SEVERAL OTHER CONVECTIVE ALLOWING MODELS AND HAVE BEEN GUIDED ON
THROUGH MID-AFTERNOON. AFTERWORDS HAVE LEANED TOWARD THE SLIGHTLY
SLOWER 09.00 NAM THAN GFS.
THIS MORNING...REMNANT MCV/SHORT WAVE ENTERING WESTERN IL EARLY
THIS MORNING HAS BEGUN TO INCREASE RADAR ECHOES ACROSS CENTRAL IL
AND THIS TREND IS LIKELY TO CONTINUE WITH SCATTERED CONVECTION
FAVORED DUE TO MODERATE TO HIGH ELEVATED INSTABILITY. NOT A
PARTICULARLY STRONG LOW-LEVEL JET OR ONE WITH HUGE MOISTURE
TRANSPORT THIS MORNING...DUE TO STILL BEING A GOOD DISTANCE AHEAD
OF MID-LEVEL HEIGHT FALLS. SO MORNING SCATTERED TO NUMEROUS
SHOWERS/STORMS ACROSS CENTRAL IL MAY STRUGGLE TO PROGRESS
NORTH/NORTHEAST AT LEAST AT ANY GOOD CLIP OF SPEED. THUS ROCKFORD
TO CHICAGO HAVE POPS ONLY AT THE CHANCE LEVEL...AND MORE SO BASED
ON ISOLATED CELLS DEVELOPING IN THE BROAD WAA AND HIGH PWAT
REGIME. WITH SUCH HIGH PWATS AS YESTERDAY MORNING SHOWED...LOCALLY
HEAVY RAINFALL WOULD BE THE PRIMARILY ASPECT TO KEEP AN EYE ON
WITH THESE MORNING AND EARLY AFTERNOON STORMS. AS FOR EARLY
MORNING FOG/STRATUS THAT HAS BEEN DEVELOPING IN PLACES...ONSHORE
FLOW MAY FAVOR PATCHES OF THIS TO CONTINUE THROUGH MID OR EVEN
LATE MORNING ACROSS NORTHEAST IL AND FAR NORTHWEST IN...STUNTING A
TEMPERATURE CLIMB INITIALLY. OTHERWISE THIS LOOKS LIKE IT SHOULD
BEGIN DISSIPATING/RETREATING NORTH AFTER THAT TIME.
CONFIDENCE...HIGH.
THIS AFTERNOON THROUGH TONIGHT...THE END OF THE RAP RUN AGREES
CLOSELY WITH THE NAM IN TAKING THE SHORT WAVES AND ASSOCIATED 500
AND 700MB SPEED MAXS ACROSS THE DAKOTAS AND NORTHERN NEBRASKA
EARLY THIS MORNING AND TRACKING THAT EAST INTO SOUTHERN WI AND
NORTHERN IL BY MID TO LATE AFTERNOON. ON THE SYNOPTIC SCALE AT
THAT TIME...THE LOW-LEVEL JET AND MOISTURE TRANSPORT WILL ALSO BE
ON THE EXPANSE FROM MO INTO EASTERN IA/WESTERN IL. MIXED LAYER
INSTABILITY WILL BE HIGH OVER THIS AREA INCLUDING THE WESTERN
FORECAST AREA GIVEN TEMPS IN THE UPPER 80S TO LOWER 90S. WHILE
SOME FORM OF MCS OR MULTIPLE CLUSTERS ARE PROBABLE TO BE MOVING
EASTWARD OVER SOUTHERN WI/FAR NORTHERN IL DURING THE AFTERNOON
WITH THE SHORT WAVES...DEVELOPMENT IS FAVORED TO WORK ITS WAY
SOUTH AND BACK TO THE SOUTHWEST FROM THERE IN THE MOIST UNSTABLE
AIR MASS DURING THE MID-AFTERNOON. DEEP LAYER SHEAR IS ANTICIPATED
TO BE INCREASING TO AROUND 30-35 KT BY LATE AFTERNOON WITH
ORGANIZED STORMS EXPECTED TO BE ALL WORKING THEIR WAY EASTWARD. AS
THE PRIMARY UPPER TROUGH APPROACHES THIS EVENING...LARGER SCALE
ASCENT AND FORCING IS LIKELY TO CONTINUE REGIONAL DEVELOPMENT OF
STORMS NEAR AND AHEAD OF THE SURFACE FRONT. SO WHILE THERE LOOKS
TO BE TWO PRIMARY FOCUSES FOR STORMS THIS AFTERNOON INTO
TONIGHT...THERE IS NOT REALLY ANTICIPATED TO BE MUCH OF A BREAK
AND THE HIGH PWAT AND UNSTABLE AIR SHOULD ALLOW FOR PLENTY OF
COVERAGE. THAT COVERAGE MAY INITIALLY BE A LITTLE LIMITED
DEPENDING ON DEBRIS CLOUD COVER BUT IS ANTICIPATED TO BE ITS
HIGHEST LATER THIS AFTERNOON THROUGH EARLY OVERNIGHT.
THE MOST FAVORED MODE FOR STORMS IS MULTICELL AND SEGMENTS
CAPABLE OF SCATTERED DAMAGING WINDS...ESPECIALLY AS THE STRONGER
MID-LEVEL JET OVERRIDES THE FRONT THIS EVENING INTO EARLY
OVERNIGHT. SOME DEVELOPMENT THIS AFTERNOON THROUGH MID-EVE HAS
THE POTENTIAL TO BE SUPERCELLULAR. THE LOW-LEVEL SHEAR IS FAIRLY
ANEMIC MUCH OF THIS AFTERNOON /AOB 10 KT/ BUT QUICKLY INCREASES
LATE INTO EARLY THIS EVE DUE TO THE DEEPENING LOW AND INCREASING
LLJ. THIS WILL HELP FAVOR COLD POOL SUSTAINABILITY AND DOES PRESENT
AT LEAST SOME TORNADO THREAT...ALTHOUGH IT LOOKS LIKE SURFACE
WINDS MAY BE BACKED MORE TO THE WEST OF THE FORECAST AREA
IMMEDIATELY AHEAD OF A SUBTLE SECONDARY SURFACE LOW MOVING UP THE
FRONT. SO THE PRIMARY THREAT WILL REMAIN WIND AND OF COURSE HEAVY
RAIN WITH EXTREMELY EFFICIENT RAIN PRODUCTION WILL OCCUR IN ANY
STORMS TODAY AND TONIGHT. EVEN THOUGH FORWARD PROPAGATION OF
STORMS SHOULD BE ON THE INCREASE TONIGHT...SO WILL DEEP MOISTURE
REPLENISHMENT AND SIMPLY PUT THE ABSOLUTE MOISTURE IS SO HIGH IT
WONT TAKE MUCH TO GET HIGH RAINFALL RATES SUCH AS WE SAW YESTERDAY
MORNING. THERE WILL LIKELY BE SWATHS OF RAINFALL IN EXCESS OF ONE
TO TWO INCHES ACROSS THE IMMEDIATE REGION...BUT WHERE EXACTLY
THEY OCCUR IS TOO CHALLENGING TO LOCK DOWN. DEBATED ON A FLASH
FLOOD WATCH BUT FEEL THE THREAT IS TOO LOCALIZED AT THIS TIME FOR
A WATCH.
CONFIDENCE...MEDIUM.
WEDNESDAY...ONGOING SCATTERED SHOWERS AND STORMS ARE POSSIBLE
ACROSS MAINLY THE SOUTHERN AND EASTERN FORECAST AREA IN THE
MORNING WITH STILL AT LEAST SOME HEAVY RAIN THREAT. WARM
850-925MB AIR BEHIND THE SURFACE WIND SHIFT WILL STILL FAVORED
HIGHS IN THE MID TO POSSIBLY EVEN UPPER 80S IN THE SOUTH. DRIER
AIR WILL GRADUALLY FILTER IN DURING THE LATER AFTERNOON AND NIGHT
PER GUIDANCE.
CONFIDENCE...HIGH.
THURSDAY THROUGH MONDAY...PRIMARILY DRY WEATHER IS EXPECTED OVER
THE AREA ALTHOUGH THE TREND IN BOTH THE EC AND GFS THEIR LAST
MULTIPLE RUNS SUPPORTS WARMER TEMPERATURES THIS WEEKEND WITH MID
AND MAYBE EVEN UPPER 80S SEEN. HAVE COLLABORATED AND LEANED TOWARD
THE WARMER MEX GUIDANCE. THE PATTERN STILL APPEARS BLOCKED JUST
WITH THE AREA MORE UNDER THE INFLUENCE OF THE UPPER RIDGE TO THE
WEST.
MTF
&&
.HYDROLOGY...
410 AM CDT
THE VERY MOIST AIR MASS WILL SUPPORT EFFICIENT RAINFALL PRODUCTION
FROM ANY THUNDERSTORMS TODAY AND TONIGHT. THIS MAY PRESENT FLASH
FLOODING ESPECIALLY ON THE LOCAL LEVEL AS OPPOSED TO ANY WIDESPREAD
THREAT. THAT AND THE FACT THERE IS NOT A GREAT SET UP FOR TRUE
TRAINING STORMS IS WHY NO FLASH FLOOD WATCH AT THIS TIME.
HOWEVER...IF ANY STORMS ARE IN A PARTICULARLY VULNERABLE
AREA...SUCH AS A METRO OR A QUICK-RESPONDING WATERSHED...IT COULD
BE TROUBLE. THESE TYPE OF HIGH RATES WERE ALREADY SEEN YESTERDAY
MORNING WITH A NARROW SWATH OF ONE AND A HALF TO ESTIMATED THREE
PLUS INCHES OF RAIN SEEN FROM RE-FIRING STORMS IN THE WEST CHICAGO
METRO. HIGH RESOLUTION MODEL GUIDANCE INDICATES SUCH SWATHS ARE
PROBABLE IN THE REGION THIS AFTERNOON INTO TONIGHT ALTHOUGH WHERE
IS STILL UNCERTAIN. THE GENERAL RAINFALL FORECAST IS FOR MOST
AREAS TO SEE AROUND AN INCH OR A LITTLE OVER BY WEDNESDAY MORNING.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* ONE BAND OF SCATTERED TSRA EXPECTED BETWEEN 17-19Z...VERY BRIEF
IFR VSBY POSSIBLE.
* NEXT ROUND OF TSRA EXPECTED LATE TOWARD 20/21Z FROM THE
WEST...BETTER ORGANIZATION AND LOWER VSBY IS MORE LIKELY WITH
THIS ROUND.
* SOME CHANCE OF ADDITIONAL SHRA/TSRA LATE TONIGHT OR EARLY
WEDNESDAY MORNING.
MDB
//DISCUSSION...UPDATED 16Z...
CONVECTIVE POTENTIAL STARTING TO BECOME A BIT MORE CLEAR. ONE
CLUSTER OF SHRA/TSRA CONTINUES TO APPROACH FROM THE WEST WITH
FLUCTUATIONS IN INTENSITY AND COVERAGE. INDIVIDUAL TS CELLS ARE
PRETTY SMALL BUT CONTINUE TO POP SO WILL CARRY VCTS AND A PERIOD
OF TEMPO TS AT THE TERMINALS OVER THE NEXT FEW HOURS...THOUGH
COVERAGE MAY BEGIN TO WANE. VERY BRIEF IFR VSBY IS POSSIBLE UNDER
THE HEAVIER CELLS. THE NEXT ROUND OF STORMS IS TAKING SHAPE ACROSS
EASTERN AND SOUTH CENTRAL IOWA WHICH WOULD ARRIVE IN THE AREA MID
TO LATE AFTERNOON. THERE SHOULD BE SHORT BREAK IN TS BEHIND THE
INITIAL AREA BEFORE THIS NEXT AREA ARRIVES. THIS SECOND AREA WILL
LIKELY BE MORE WIDESPREAD IN COVERAGE WITH LONGER PERIODS OF LOW
VISIBILITY POSSIBLE...ALONG WITH THE POTENTIAL FOR GUSTY WINDS.
THIS ALSO POINTS TO THE EVENING HOURS BEING QUIET SO WILL NEED TO
RE-EVALUATE SHRA/TSRA MENTION THEN.
MDB
FROM 12Z...
RELATIVELY QUIET ACROSS THE TERMINALS THIS MORNING WHILE SOME
FOG/HAZE REMAINS OVERHEAD...BUT WITH THE MORE DENSE FOG REMAINING
AWAY FROM THE TERMINALS AT THIS TIME. ANY FOG THIS MORNING SHOULD
QUICKLY DISSIPATE OVER THE NEXT HOUR WITH ANY THREAT OF LOWER
VIS/CEILINGS COMING SOUTH DOWN THE LAKE REMAINING LOW AT THIS
TIME. ALTHOUGH THIS AREA IS STILL SLOWLY MOVING SOUTH DOWN THE
LAKE...VEERING WINDS AND SHOULD HELP LIMIT THIS SOUTHWARD MOMENTUM
KEEPING THIS FOG NORTH OF THE TERMINALS. THEN SHIFT GEARS TO
REDEVELOPMENT OF SHOWERS/TS LATER THIS MORNING...AS PRECIP
DEVELOPS OUT AHEAD OF AN APPROACHING MID LEVEL DISTURBANCE. AS
THIS DISTURBANCE DRAWS NEAR...EXPECT CURRENT THUNDERSTORMS OVER
IOWA AS WELL AS OTHER DEVELOPMENT TO MOVE ACROSS THROUGH NORTHERN
ILLINOIS/NORTHWEST INDIANA BY MID DAY WITH SOME UPWARD GROWTH IN
COVERAGE AND INTENSITY EXPECTED INTO THE EARLY AFTERNOON. DO
EXPECT A BRIEF LULL IN THE ACTIVITY AFTER THIS INITIAL PRECIP
MOVES THROUGH...BUT WITH DEVELOPMENT STILL POSSIBLE GOING INTO THE
EARLY EVENING. STILL MONITORING THE POTENTIAL FOR A MORE
WIDESPREAD AREA OF THUNDERSTORMS TO MOVE ACROSS THE TERMINALS
LATER THIS EVENING AND OVERNIGHT. ALTHOUGH IT STILL SEEMS
FAVORABLE FOR THIS TO MOVE ACROSS THE TERMINALS...WILL NEED TO
MONITOR LATER TRENDS AFTER THIS INITIAL PRECIP THIS AFTERNOON
MOVES THROUGH.
WINDS REMAIN LIGHT/VARIABLE THIS MORNING BUT ANTICIPATE A TREND
TOWARDS AN EAST NORTHEAST WIND OVER THE NEXT SEVERAL HOURS. WINDS
ALONG THE LAKE ARE ALREADY THIS EASTERLY COMPONENT AND WITH THE
SUN RISING COINCIDING WITH A WEAK GRADIENT...FEEL THAT IT WONT
TAKE MUCH FOR THIS NORTHEAST WIND TO DEVELOP OVER ORD/MDW/GYY THIS
MORNING. THEN EXPECT A SLOW TREND TOWARDS THE SOUTHEAST AND
EVENTUALLY SOUTH THIS AFTERNOON/EVENING...BEFORE WINDS CONTINUE TO
VEER TO THE WEST OVERNIGHT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN BAND OF SHRA/TSRA 17-19Z...MAY BE FAIRLY
SCATTERED THOUGH...HIGH CONFIDENCE THAT ANY IFR VSBY WOULD BE BRIEF.
* MEDIUM-HIGH CONFIDENCE IN ADDITIONAL ACTIVITY ARRIVING LATER
THIS AFTERNOON AND IT WOULD BE MORE WIDESPREAD AND
INTENSE...MEDIUM CONFIDENCE IN TIMING.
* LOW CONFIDENCE IN POTENTIAL FOR ADDITIONAL ACTIVITY
TONIGHT/WEDNESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
RODRIGUEZ
&&
.MARINE...
427 AM CDT
MAIN FORECAST CONCERN IN THE NEAR TERM IS FOR AREAS ACROSS THE
NORTHERN TWO THIRDS OF THE LAKE...WHERE DENSE FOG HAS SETTLED IN.
EXPECT THIS FOG TO PERSIST AT LEAST THROUGH THE AFTERNOON WITH
CURRENT THINKING THAT THIS FOG WILL CHURN UP WITH APPROACHING
PRECIP. ALTHOUGH CONFIDENCE IS LOW...AND ITS POSSIBLE THE CURRENT
DENSE FOG ADVISORY IN PLACE THROUGH THE AFTERNOON COULD NEED TO BE
EXTENDED THROUGH THE EVENING. THERE IS ALSO POTENTIAL FOR THE MORE
DENSE FOG TO PUSH FURTHER DOWN THE LAKE EARLY THIS
MORNING...BEFORE WINDS BEGIN TO SHIFT AND BRING A STOP TO THIS
SOUTHWARD MOVING AREA OF FOG.
CURRENT LIGHT NORTHERLY WINDS IN PLACE ACROSS THE LAKE WILL TURN
MORE SOUTHERLY THROUGHOUT TODAY AS THE NEXT SYSTEM APPROACHES FROM
THE WEST. AS THIS SYSTEM THEN PROGRESSES ACROSS THE LAKE
TONIGHT...EXPECT SOUTHWEST WINDS TO BECOME MORE WESTERLY WHILE
INCREASING MORE TOWARDS THE 10 TO 20 KT RANGE. THEN AS HIGH
PRESSURE SLOWLY BUILDS EAST TOWARDS THE LAKE...EXPECT GENERALLY
NORTHERLY WINDS THROUGH THE REST OF THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ868-LMZ870-LMZ872-LMZ874
UNTIL 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1244 PM CDT TUE JUL 9 2013
.UPDATE...
ISSUED AT 1050 AM CDT TUE JUL 9 2013
2 MAJOR UPDATES HAVE BEEN SEND THIS MORNING...REFLECTING CHANGES
BASED ON RADAR TRENDS...AND NOW BOTH CONVECTIVE TRENDS COMBINED
WITH MORNING UA ANALYSIS AND EARLY SIGNALS IN MODEL GUIDANCE.
THE PARADE OF TWO MCV FEATURES IS NOTED ON RADAR AND
SATELLITE...AND THUS THE NEXT 4 HOURS WILL CERTAINLY BE OUR MAIN
SHOW WITH RESPECT TO RAINFALL POTENTIAL. AMOUNTS THUS FAR ARE
SCATTERED AND SIGNIFICANT ...OVER 1 INCH......BUT MOST OF THE AREA
RECEIVING ONLY LIGHT AMOUNTS OR NEARLY DRY...ESPECIALLY SOUTH.
SURFACE CAPE WILL BE LIMITED TO ONLY THE SOUTH TODAY AND EARLY
THIS EVENING...THUS OUR BEST POTENTIAL FOR MORE SIGNIFICANT STORMS
IS THERE. ELSEWHERE I HAVE CONTINUED TO LOWER EVENING POPS...AS
WELL AS AFTERNOON POPS IN THE WEST. TONIGHT COULD VERY WELL BE DRY
OVER OUR WESTERN 1/3 OF THE CWA...AND POSSIBLY WESTERN 2/3 IF THE
VEERED MOISTURE PLUME CANNOT RECOVER FROM THE MCV PASSAGES. THIS
GREATLY WILL LOWER THE SEVERE THREAT...AND I WILL AWAIT THE SPC
UPDATE BEFORE UPDATING THE HWO TO REFLECT THAT POSSIBLE LOWERED
MAGNITUDE OF THE THREAT.
TEMPERATURES HAVE BEEN LOWERED TO MAINLY MID 80S HIGHS...WHICH
SHOULD EASILY OCCUR ONCE CONVECTION STOPS FIRING...BUT SAFE TO
SAY...OUR NEAR ADVISORY LEVEL HEAT WILL NOT VERIFY TODAY. IT WILL
MOST CERTAINLY BE QUITE MUGGY OUT THERE.
ERVIN
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT TUE JUL 9 2013
06Z MSAS SFC ANALYSIS SUPPORTIVE OF WEAK LOW OVER CENTRAL SD WITH
STATIONARY FRONT EXTENDING SEWD FROM THE LOW AND BISECTING
EASTERN IA AND NORTHWEST IL. MOISTURE IS POOLING ALONG THE FRONT
WITH DEWPTS OF 70-75F. 00Z KDVN RAOB SHOWS DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES OF NEARLY 2 INCHES... WHICH IS AROUND 160
PERCENT OF NORMAL AND NEARLY 2 STANDARD DEVIATIONS ABOVE THE MEAN.
CONVECTIVELY ENHANCED VORT MAX IS TRACKING THROUGH EASTERN NE ATTM
WITH RADARS SHOWING SHOWERS AND STORMS AHEAD OF THIS FEATURE INTO
WESTERN IA. ADDITIONAL COMPLEX OF STORMS WAS OVER THE DAKOTAS
AHEAD OF COLD FRONT AND SHORTWAVE MOVING EAST THROUGH FAR SOUTHERN
ALBERTA PROVINCE AND NORTHERN MT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT TUE JUL 9 2013
SUGGESTIONS OF 2 MAIN ROUNDS OF STORMS THROUGH THE PERIOD. AS
CONVECTIVELY ENHANCED VORT MAX MOVES EAST FROM NE ANTICIPATE
SHOWERS AND STORMS TRACKING AHEAD OF THIS FEATURE TO MOVE ACROSS
THE REGION BY MID AM THROUGH EARLY AFTN. PRIOR TO THE ARRIVAL
OF THESE STORMS COULD SEE ADDITIONAL DEVELOPMENT PRIOR TO MID AM
OVER THE AREA WITH WARM ADVECTION WING. POTENTIAL FOR SOME
STRENGTHENING OF MID LEVEL WINDS AND INTENSIFICATION OF STORMS
BY LATE AM AND AFTN FOR RISK OF FEW STRONG TO ISOLD SEVERE STORMS
WITH MOST RECENT RUNS OF HRRR 2-5KM UPDRAFT HELICITY AND 3 KM
VELOCITY CONTINUING TO SUGGEST THIS RISK NEAR AND ESPECIALLY NORTH
OF I-80. MAY SEE BREAK IN ACTION OR RELATIVE LULL IN ACTIVITY
BY MID-LATE AFTN WITH FOCUS SHIFTING BACK NORTHWEST FOR DEVELOPMENT
AHEAD OF COLD FRONT. LIKELY TO SEE ANOTHER ROUND OF STORMS MOVE
THROUGH THIS EVENING INTO OVERNIGHT AHEAD OF COLD FRONT.
STRENGTHENING 40-60 KT MID LEVEL SPEED MAX SPREADING BEHIND FRONT
COUPLED WITH VERY UNSTABLE ENVIRONMENT WILL SUPPORT RISK OF SEVERE
STORMS WITH POTENTIAL FOR UPSCALE GROWTH TO LINEAR MCS WITH MAINLY
DAMAGING WIND THREAT. HEAVY RAIN WILL BE A CONCERN AS WELL GIVEN
THE DEEP ALMOST TROPICAL MOISTURE IN PLACE. STORMS SHOULD BE MOVING
ALONG MORE THAN WE/VE SEEN OF LATE BUT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH RATES LIKELY 1-2"/HR. THUS... CANT RULE OUT SOME
LOCALIZED FLASH FLOODING AND WILL HAVE TO BE ESPECIALLY WATCHFULL
OVER PORTIONS OF DELAWARE AND DUBUQUE COUNTIES WHICH HAVE SEEN 2-5
INCHES PAST 24-36 HRS. EXPECT PCPN SHOULD BE DIMINISHING FROM NW
TO SE OVRNGT WITH PASSAGE OF COLD FRONT.
HIGHS TDY TRICKY WITH CLOUDS AND PCPN BUT OVERALL SHOULD RANGE FROM
MID 80S TO THE LOWER 90S. SOME MIXING OUT OF DEWPTS MAY OCCUR BUT
AT LEAST UPPER 60S TO LOWER 70S EXPECTED ON DEWPTS... WHICH COMBINED
WITH TEMPS WILL MAKE FOR HEAT INDICES MAINLY IN THE MID TO UPPER 90S.
COOLER AND DRIER AIR LAGS BEHIND FRONT TNGT... THUS LOWS ONLY DROP
INTO THE UPPER 60S TO LOWER 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 330 AM CDT TUE JUL 9 2013
WEDNESDAY AND THURSDAY...AS L/W TROF CONTINUES TO DEEPEN AND
ESTABLISH ACRS THE GRT LKS...SEASONABLY STRONG LLVL HIGH PRESSURE
WILL LOOK TO DUMP DOWN THE NORTHERN PLAINS AND MO RVR VALLEY ON WED.
A FEW POST-FRONTAL SHOWERS AND STORMS MAY BE OCCURRING ACRS THE FAR
EASTERN/SOUTHERN CWA WED MORNING BUT BULK OF THE ACTIVITY SHOULD BE
GONE BY 15Z. VEERING AND INCREASING BOUNDARY LAYER FLOW AS WELL AS
INCOMING SUBSIDENCE SHOULD CLEAR THINGS OUT ON WED...BUT SOME LAG IN
CAA TO ALLOW TEMPS TO WARM INTO THE LOW TO MID 80S EVEN POST-
FRONTALLY. A RATHER BREEZY NORTHWEST TO NORTH WIND OF 15-20 MPH.
CLEAR SKIES AND WIND DROP OFF WED NIGHT TO ALLOW SOME AREA TEMPS TO
DROP OFF INTO THE 50S. LLVL HIGH PRESSURE CONTINUING TO MIGRATE
EASTWARD ACRS THE REGION TO MAKE FOR A CHAMBER OF COMMERCE DAY THU
WITH HIGHS IN THE UPPER 70S TO LOWER 80S...SUNSHINE AND LOWER
HUMIDITY. THU NIGHT SEASONABLY COOL AGAIN WITH LOWS IN THE 50S AND
LOW 60S.
FRIDAY THROUGH NEXT MONDAY...TRENDS OF THE LATEST RUN 00Z MEDIUM
RANGE SOLUTIONS AND ENSEMBLES SUGGEST SOME DIGGING TROFFINESS IN THE
PACIFIC NORTHWEST/WESTERN CANADA TO TRANSLATE INTO PUMPED UP UPPER
RIDGING ACRS THE MID CONUS FRI INTO SAT. THUS WHILE THERMAL DOME
INTENSIFIES ACRS THE GRT BSN INTO THE SOUTHWESTERN PLAINS...MCS
TRACK/RING OF FIRE PATTERN TO ESTABLISH IN NORMAL DEEP SUMMER
LOCATION OF NORTHWESTERN HIGH PLAINS...UPPER MS RVR VALLEY...SOUTHERN
CANADA AND INTO THE GRT LKS. LATEST INDICATIONS SUGGEST A LESSENING
CHANCE FOR SOME OF THIS MCS ACTIVITY TO SPILL DOWN ACRS THE
NORTHERN CWA EITHER FRI NIGHT OR SAT NIGHT WHILE TEMPERATURES START
TO REBOUND BACK TO NORMAL OR EVEN WARMER. BY SUNDAY...WESTERLIES
FIRMLY ESTABLISH ACRS THE U.S.-CANADIAN BORDER REGION WITH UPPER
RIDGING DOMINATING ACRS THE SOUTHERN 2/3S OF THE CONUS. LONGER
RANGE THERMAL PROFILES SUGGEST ENOUGH AIRMASS MODIFICATION TO DRIVE
SUNDAY HIGHS UP INTO AT LEAST THE LOWER 90S ALONG WITH INCREASING
SFC DPTS/HUMIDITY. PASSING WAVE IN THIS PROGRESSIVE FLOW MAY TRY TO
SHUNT DOWN A WEAKENING SFC BOUNDARY DOWN TOWARD OR ACRS THE CWA
LATER SUNDAY NIGHT OR MONDAY AND GET SLOWED AS IT ALIGNS PARALLEL TO
MEAN STEERING FLOW. THUS THIS WINDOW MAY BE THE NEXT REAL CHANCE FOR
SOME PRECIP IN THE AREA AFTER TODAY/TONIGHT. LONGER RANGE SIGNALS ON
THE LATEST RUNS ESPECIALLY THE NEW 00Z ECMWF SUGGESTS THAT THIS
BROAD UPPER RIDGING PATTERN TO CONTINUE TO REIGN ACRS MUCH OF THE
CONUS WELL INTO MID NEXT WEEK...WHILE THE TROPICS CONTINUE TO GET
INTERESTING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1239 PM CDT TUE JUL 9 2013
AS SCATTERED SHOWERS AND STORMS MOVED OVER EASTERN IOWA AND
ILLINOIS EARLIER TODAY...THEY REMOVED MUCH OF THE INSTABILITY
NEEDED FOR THE EALIER FORECAST STRONG THUNDERSTORMS. THUS...ANY
NEW AFTERNOON THUNDERSTORMS AND EVENING STORMS WILL BE MORE
SCATTERED THAN WIDESPREAD...AND DUE TO THIS LOW COVERAGE AND LOW
CONFIDENCE...ALL STORMS HAVE BEEN REMOVED FROM TAFS. VFR
CONDITIONS WITH MID AND HIGH CLOUDS OR CLEAR SKIES...AND SOUTH
WINDS WILL CONTINUE THROUGH LATE EVENING...WHEN THE COLD FRONT
ARRIVES. AS THE FRONT ARRIVES...WINDS MAY DECREASE ALLOWING FOR
PATCHY FOG DEVELOPMENT...AND A TEMPO FOR FOG HAS BEEN PLACED INTO
ALL TAFS FROM AROUND 04Z TO 08Z TONIGHT. AFTER THIS...NORTHWEST
WINDS SHOULD DISSIPATE FOG...AND RETURN TO VFR CONDITIONS.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...ERVIN
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
302 PM CDT TUE JUL 9 2013
...UPDATED SHORT TERM...
.SYNOPSIS...
ISSUED AT 300 PM CDT TUE JUL 9 2013
ON THE SYNOPTIC SCALE, A MUCH MORE ZONAL FLOW HAS DEVELOPED ACROSS
THE CONUS WITH A POLAR JET FOCUSES ACROSS THE NORTHERN STATES, AND
A BROAD MID LEVEL SHORTWAVE EMBEDDED IN THE FLOW ACROSS EASTERN
MONTANA. TEMPERATURES WARMED INTO THE UPPER 80S TO AROUND 90 DEGREES
BY 11 AM ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS. TEMPERATURES
WERE SLIGHTLY SLOWER TO RESPOND ACROSS SECTIONS OF WEST CENTRAL
KANSAS WHERE BANDS OF MID LEVEL STRATOCUMULUS WERE PRESENT. THIS
PATTERN INCLUDES A FLATTENING OF THE UPPER ANTICYCLONE NOW LOCATED
FROM THE DESERT SOUTHWEST INTO THE SOUTHERN PLAINS. THE 12 UTC 700
MB ANALYSIS SHOWED A WARM PLUME OF MID LEVEL AIR ACROSS EASTERN
COLORADO AND WESTERN KANSAS AS WARM AS 15 DEGREES C. THE 850 MB
LEVEL TROUGH WHICH EXTENDED ACROSS THE NORTHERN AND CENTRAL HIGH
PLAINS CREATED A DOWNSLOPE SURFACE WIND FIELD OVER SOUTHWEST AND
CENTRAL KANSAS WITH TEMPERATURES IN THE UPPER 20`S C. AT THE SURFACE,
A BETTER IDENTIFIED COLD FRONT BASED ON SURFACE MOISTURE
DISCONTINUITY EXTENDED ACROSS WESTERN NEBRASKA THROUGH THE EASTERN
DAKOTAS, WHILE AN AREA OF LOW PRESSURE AHEAD OF THE BOUNDARY
EXHIBITED ANS ATTENDANT TROUGH FROM CENTRAL NEBRASKA INTO WEST
CENTRAL KANSAS. JUST AHEAD OF THE SURFACE TROUGH, DEW POINTS OF 60
TO 65 DEGREES CONTRIBUTED TO PRECIPITABLE WATER VALUES IN EXCESS OF
AN INCH AND A HALF THROUGH THE INTERSTATE 70 AND HIGHWAY 156
CORRIDORS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 300 PM CDT TUE JUL 9 2013
THE HEAT AND CONVECTIVE CHANCES INCLUDING POTENTIAL IMPACTS ARE THE
MAIN FORECAST ISSUES EARLY IN THE SHORT TERM. THE HEAT ADVISORY WILL
BE MAINTAINED IN IT`S CURRENT CONFIGURATION ALTHOUGH THE WESTERN
PERIPHERY MAY BE SUSPECT TO MEETING LOW END ADVISORY CRITERIA DUE TO
SURFACE DEW POINTS THAT HAVE MIXED OUT INTO THE MID/UPPER 50`S. IF
THE TREND CONTINUES INTO EARLY AFTERNOON, IN EFFECT TEMPERATURES
ALSO ARE NOT TRENDING AS WARM AS FORECAST, SOME AREAS ALONG THE
WESTERN PERIPHERY MAY NEED TO BE TRIMMED FROM THE ADVISORY.
THE NAM/ WRF NMM AND ARW ALL DEVELOP CONVECTION ALONG THE FRONTAL
BOUNDARY EXTENDING INTO NORTHWEST KANSAS THIS AFTERNOON. SIGNIFICANT
DIFFERENCES IN COVERAGE EXISTS BETWEEN THE MODELS, VARYING FROM
RATHER ISOLATED CLUSTERS TO MORE ORGANIZED LINE SEGMENTS WITH
PROLIFIC OUTFLOW. THE HRRR IS PARTICULARLY AGGRESSIVE WITH
DEVELOPING HEAVY QPF AND RAIN COOLED OUTFLOW OF 30 KNOTS LOCALLY
RIGHT AHEAD OF THE FRONT ALONG THE MAXIMUM DEW POINT AND PWAT
GRADIENT. HOWEVER THE WEATHER EVOLVES THIS AFTERNOON AND EVENING
MAY HAVE AN IMPACT ON TEMPERATURES AND CONVECTIVE CHANCES AGAIN ON
WEDNESDAY AFTERNOON. HOWEVER, THE BETTER CHANCE FOR CONVECTION ON
WEDNESDAY WILL LIKELY OCCUR DUE TO DIFFERENTIAL HEATING OVER THE
HIGHER TERRAIN OF EASTERN COLORADO, INCREASING CHANCES ACROSS
WESTERN KANSAS INTO WEDNESDAY EVENING. HIGHS WEDNESDAY WILL BE
AROUND 10 DEGREES COOLER BEHIND THE BOUNDARY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE JUL 9 2013
A WARM AND FAIRLY DRY PERIOD BEGINS AFTER WEDNESDAY NIGHT AS A LARGE
RIDGE OF UPPER LEVEL HIGH PRESSURE BUILDS INTO THE PLAINS.
FOR WEDNESDAY NIGHT WILL MAINTAIN A 30 TO 40 PERCENT CHANCE OF
THUNDERSTORMS JUST NORTH OF A WEAK FRONTAL BOUNDARY IN MOIST UPSLOPE
REGIME ACROSS MUCH OF WESTERN KANSAS. THIS WILL BE OUR BEST CHANCE
OF SEEING MEASURABLE RAINFALL INTO NEXT WEEK. WITH WEAK WINDS ALOFT
NOT EXPECTING SEVERE WEATHER. THERE COULD BE SOME LOCALLY HEAVY
DOWNPOURS IF STORMS GET GOING AND THEY ARE SLOW MOVING.
A WESTWARD MOVING UPPER LOW BEGINS TO UNDERCUT THE RIDGE ACROSS THE
SOUTHERN AND CENTRAL PLAINS FROM SUNDAY INTO TUESDAY WITH A SLIGHT
CHANCE OF THUNDERSTORMS ON MONDAY NEAR A CONVERGENCE LINE, ALONG
WITH SLIGHTLY COOLER TEMPERATURES.
OVERNIGHT LOWS WILL BE MILD AROUND 70 TO 75 THROUGH THE PERIOD.
DAYTIME HIGHS WARM BACK TO AROUND 100 TO 105 ON FRIDAY AND SATURDAY
THEN COOL SLIGHTLY BACK INTO THE MID TO UPPER 90S INTO NEXT TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 200 PM CDT TUE JUL 9 2013
WITH THE EXCEPTION OF THE POSSIBILITY OF SEVERE CONVECTION PRODUCING
40 TO 50 KNOT WIND GUSTS LATE THIS AFTERNOON AND EARLY EVENING, THE
AREA INCLUDING THE LOCAL TERMINALS WILL BE UNDER VFR CONDITIONS.
CONVECTION MAY DEVELOP ALONG A SURFACE FRONT NORTHWEST OF HAYS
BETWEEN 21 AND 00 UTC. THE ATMOSPHERE IS CONDUCIVE TO PRODUCING
WIDESPREAD THUNDERSTORMS OUTFLOW, WITH LOCALLY SEVERE GUSTS IN A
ONE TO TWO HOUR EPISODE ENDING IN THE EARLY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 97 70 98 / 40 30 30 10
GCK 71 95 69 99 / 40 30 30 10
EHA 71 96 69 101 / 20 30 30 10
LBL 72 98 70 102 / 30 30 30 10
HYS 72 94 69 95 / 40 20 20 20
P28 76 100 72 97 / 40 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ030-031-044>046-
064>066-078>081-088>090.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...KRUSE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
329 PM EDT TUE JUL 9 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 329 PM EDT TUE JUL 9 2013
ISOLD TO SCT SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS THE
AREA THIS AFTERNOON. MORE SUBSTANTIAL AREA OF CONVECTION HAS FIRED
OVER OHIO. HRRR HAS ACTUALLY BEEN DOING DECENT WITH CONVECTIVE
INITIATION ACROSS AREAS NORTH OF THE OHIO RIVER. IN GENERAL IT KEEPS
THE BULK OF ACTIVITY NORTH AND EAST OF OUR CWA...THOUGH RADAR TRENDS
WOULD SUGGEST THAT OUR NORTHERN AND EASTERN COUNTIES MAY GET BRUSHED.
INCREASED POPS ACROSS THE NORTHERN/EASTERN PORTIONS OF OUR CWA FOR
THE LATE AFTERNOON AND EARLY EVENING TIME FRAME. PER THE HRRR...WITH
COMPLEX OF STORMS PASSING GENERALLY TO OUR EAST THIS EVENING AND LOSS
OF DIURNAL HEATING GRADUALLY DROPPED POPS OFF THROUGH THE NIGHT.
HOWEVER...RAMPED POPS BACK UP TOWARDS DAWN AS SHORT TERM HIGH
RESOLUTION MODELS SUGGEST THE POSSIBILITY OF THE REMNANTS OF ANOTHER
COMPLEX OF STORMS ENTERING THE AREA FROM THE NORTHWEST.
OTHERWISE...MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE SHORT
TERM. A DEEPENING UPPER LEVEL TROUGH AND REFLECTED SFC COLD FRONT
WILL GRADUALLY PUSH THROUGH THE REGION WEDNESDAY NIGHT INTO EARLY
THURSDAY MORNING. PWATS OVER THE NEXT 36 TO 48 HOURS ARE SIGNIFICANT
HITTING CLIMATOLOGICAL HIGHS AT TIMES. FORECAST SOUNDINGS ARE NOT IN
AS GOOD AGREEMENT WITH RESPECT TO STORM MOTION THOUGH. THE GFS IS
MORE PROGRESSIVE WITH MOVEMENT WHEN COMPARED TO THE HIGHER RESOLUTION
RAP AND NAM. REGARDLESS...WITH SUCH HIGH PWATS AND CONSIDERING A
FAIRLY SATURATED GROUND FEEL THERE WILL BE THE POTENTIAL FOR SOME
LOCALLY HEAVY RAINFALL AND MINOR HYDRO ISSUES...ESPECIALLY WITH THE
STRONGER STORMS. CONFIDENCE WAS LACKING WITH RESPECT TO A WIDESPREAD
THREAT SO OPTED NOT TO ISSUE ANY TYPE OF FFA. BUT MAY RECONSIDER A
FLASH FLOOD WATCH WITH FUTURE FORECAST PACKAGES SHOULD MODELS COME
INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO DETAILS...AND SHOW A
MORE SIGNIFICANT THREAT. FOR NOW WILL CONTINUE TO COVER THIS
POTENTIAL IN THE HWO AND PASS CONCERNS ON TO FUTURE SHIFTS. GENERALLY
FOLLOWED INHERITED TEMPS...NUDGING SLIGHTLY TOWARDS A BLEND OF MODEL
GUIDANCE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 329 PM EDT TUE JUL 9 2013
THE MODELS HAVE A SIMILAR IDEA...THROUGH THE EXTENDED...OF A MID
LEVEL PATTERN DOMINATED BY A LARGE AREA OF RIDGING...INITIALLY OVER
THE SOUTHERN ROCKIES EXPANDING NORTHEAST WITH TIME...AND DOWNSTREAM
TROUGHING THROUGH THE GREAT LAKES LATER AFFECTING MUCH OF THE EAST
AND DEEP SOUTH. THE GREAT LAKES TROUGH STRENGTHENS A BIT ON
THURSDAY AS ITS CORE MOVES EAST AND INTO UPSTATE NEW YORK BY 12Z
FRIDAY. AT THE SAME TIME...ITS TRAILING AXIS AND MAIN ENERGY BAND
WILL SWEEP SOUTHEAST THROUGH THE LOWER OHIO VALLEY AND ACROSS EAST
KENTUCKY. THIS WILL ALLOW HEIGHTS TO BUILD IN FROM THE NORTHWEST
THROUGH THE WEEKEND WHILE THE SOUTHERN PORTION OF THE TROUGH CUTS
OFF OVER THE DEEP SOUTH AND STARTS TO CONSOLIDATE. THOUGH THE MODELS
GENERALLY AGREE ON THE RIDGE PLACEMENT...THEY DIFFER ON THE DETAILS
REGARDING THE LOWER HEIGHT CENTERS TO THE SOUTH AND EAST. INTO THIS
MIX WILL ENTER THE UPPER HEIGHT FIELD OF CHANTAL...OR WHATEVER
BECOMES OF HER...THAT COULD MOVE TO THE SOUTHEAST COAST PER THE GEM
OR STAY LOCKED OUT TO THE SOUTH AS SEEN IN THE GFS AND ECMWF. EITHER
WAY...ITS MOISTURE MAY START TO IMPACT THE AREA AS EARLY AS LATE
SUNDAY...LINGERING THROUGH THE REST OF THE EXTENDED. FOR EAST
KENTUCKY...THE RIDGE TO THE NORTH WILL BE A KEY COMPONENT IN
DETERMINING OUR WEATHER INTO THE START OF NEXT WEEK. WITH THE MODELS
IN BETTER AGREEMENT ON THIS FEATURE CONFIDENCE IS HIGHER IN GOING
DRY THROUGH AT LEAST MIDDAY SUNDAY. THEREAFTER...THE GFS...AND TO A
LESSER EXTENT THE ECMWF...DOES BRING AN UPPER LOW WEST TOWARD THE
AREA FOR TUESDAY. WITH THE DECENT AGREEMENT AMONG THE MODELS ON THE
RIDGE THROUGH THE WEEKEND...EXPECT THAT A BLEND WILL BE AN EFFECTIVE
STARTING POINT THROUGH SUNDAY. AFTER THAT...WILL LEAN MORE TOWARD
THE WEAKER...LESS AMPLIFIED...00Z ECMWF.
SENSIBLE WEATHER WILL LIKELY FEATURE SOME ONGOING CONVECTION MOVING
SOUTHEAST THROUGH THIS PART OF THE STATE ON THURSDAY MORNING AS A
COLD FRONT PASSES THROUGH EARLY IN THE DAY. HIGH PRESSURE WILL THEN
BUILD IN AND BRING A RARE SUMMER TIME SHOT OF COOLER AND DRIER AIR
FROM THE NORTH. THIS SFC HIGH...AND THE DRY WEATHER...WILL BE
SUSTAINED BY THE RIDGING BUILDING ALOFT AND SHOULD SERVE TO KEEP ANY
TROPICAL DERIVED MOISTURE OFF TO THE SOUTH AND EAST FOR THE BULK OF
THE WEEKEND. HOWEVER...THE RIDGE ALOFT WILL WEAKEN AND MOVE BACK
WEST BY LATE SUNDAY WHILE THE CORRESPONDING SFC HIGH WILL ALSO BREAK
DOWN AND ALLOW HIGH DEWPOINTS INTO THE REGION FROM THE SOUTHEAST. A
DIURNAL REGIME SHOULD THEN GUIDE THE CONVECTIVE DEVELOPMENTS ON
MONDAY AND TUESDAY WITH BUILDING INSTABILITY AND LITTLE IN THE WAY
OF CAPPING LEADING TO SCATTERED SHOWERS AND THUNDERSTORMS EACH
AFTERNOON...PARTICULARLY ACROSS OUR SOUTHEAST COUNTIES.
THE CR GRID LOAD CAME IN REASONABLE...THOUGH DID ADJUST POPS A BIT
ON SUNDAY AND MONDAY NIGHTS TO BETTER EMPHASIZE THE DIURNAL NATURE
OF THE CONVECTION. ALSO...TWEAKED OVERNIGHT LOWS ON THURSDAY THROUGH
SATURDAY NIGHTS TO ACCOUNT FOR TERRAIN BASED DIFFERENCES IN
RADIATIONAL COOLING WHILE WE ARE BENEFITING FROM THE DRIER AIR MASS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 215 PM EDT TUE JUL 9 2013
EXTENSIVE CUMULUS FIELD WILL BE IN PLACE THROUGH THE REMAINDER OF THE
AFTERNOON WITH GENERALLY SCT SKY CONDITIONS AND CLOUD BASES FROM 3000
TO 5000 FEET. WENT WITH VFR CONDITIONS THROUGH THE ENTIRE FORECAST
PERIOD. HOWEVER...STILL HAVE TO DEAL WITH CONVECTION THIS AFTERNOON
AND INTO TONIGHT. DIURNAL HEATING AND INSTABILITY IS HELPING TO KICK
OFF SOME SHOWERS ACROSS THE AREA AT TAF ISSUANCE. ASSESSING THE
DIRECT IMPACTS OF SHOWERS AND THUNDERSTORMS AT EACH TERMINAL IS AT
BEST DIFFICULT...ESPECIALLY SINCE CELLS APPEAR TO HAVE A RELATIVELY
SHORT LIFE CYCLE...BUILDING AND THEN DISSIPATING WITHIN AN HOUR.
MORE ORGANIZED CONVECTION MAY DROP SOUTHWARD INTO PORTIONS OF THE
AREA LATER THIS EVENING. CLOSELY WATCHING THE DEVELOPMENT AND
EVOLUTION OF UPSTREAM ACTIVITY. JKL WOULD BE MOST LIKELY TO BE
EFFECTED BY ANYTHING. PRECIP POTENTIAL...LATE AFTERNOON AND EARLY
EVENING RAINFALL WOULD BOOST POTENTIAL FOR BR/FOG DEVELOPMENT
OVERNIGHT. BUT FOR NOW WENT MORE OPTIMISTIC THAN MODEL GUIDANCE WITH
ONLY SOME LIGHT MIST. WINDS WILL RELATIVELY LIGHT THROUGH THE
PERIOD...AND GENERALLY FROM THE SOUTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...RAY
LONG TERM...GREIF
AVIATION...JMW/RAY
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
519 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A SERIES OF UPPER DISTURBANCES WILL MAINTAIN CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGH WEDNESDAY. A COLD FRONT WILL MOVE
THROUGH EARLY THURSDAY...BRINGING COOLER AND MORE COMFORTABLE
CONDITIONS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS PREDICTED STORMS ARE FIRING UP ACROSS CENTRAL OHIO AND MOVING
SOUTHEAST INTO EAST CENTRAL OHIO. ATMOSPHERE HAS TONS OF ENERGY TO
WORK WITH AS ANALYZED BY RAP MODEL. MUCAPES EXCEED 3.0 KJKG-1
WHILE MOISTURE CONV AND EQUIV POT TEMP ADV ARE HIGH SUPPORTING
UPSTREAM DEVELOPMENT. BUFR SOUNDINGS SHOW A TROPICAL STATE TO OUR
ENVIRONMENT WITH WARM CLOUD PROCESSES IN EFFECT. UPDATED FORECAST
TO INCREASE POPS OVER E CENTRAL OHIO AND ADD HEAVY RAIN ATTRIBUTE
TO WEATHER GRIDS BASED ON OBSERVED RAINFALL AMOUNTS.
LATEST HRRR CONTINUES TO POINTS TO AN MCS TRAVERSING SERN OH AND
NRN WV DURING THE OVERNIGHT HOURS. THESE ARE LOCATIONS THAT CAN
NOT HANDLE A LOT OF QPF. RAIN AMOUNTS LESS THAN AN INCH PER HOUR
WOULD BE ENOUGH TO CREATE FLASH FLOODING. OUR CURRENT FLASH FLOOD
WATCH LOOKS GOOD WITH NO CHANGES PLANNED. WITH INCREASED
CONFIDENCE PER RECENT HIGH RESOLUTION MODELS...RAISED POP NUMBERS
OVER THE AFOREMENTIONED AREA DURING THE NIGHT TIME HOURS.
TEMPERATURES WERE LEFT CLOSE TO A BLEND OF GFS LAMP/NAM GUIDANCE
TONIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
PCPN ONGOING WED MRNG SHOULD DECR IN CVRG BY MID-MRNG. MDT INSTBY
XPCD TO BCM ESTABLISHED THRU FCST AREA BY LATE MRNG OWING TO
COOLING MID-LVL TEMPS AND ABUNDANT LOW-LVL MSTR CHARACTERIZED BY
DEWPTS IN THE LWR 70S.
MRNG CLD CVR XPCD TO BCM BKN AND ALLOW PATCHY HEATING OF THIS VERY
MOIST AMS...WHICH WILL AID IN BOTH WEAKENING THE CAP AND
STEEPENING LOW-LVL LAPSE RATES. TSTM CVRG XPCD TO INCR MARKEDLY BY
EARLY AFTN. DESPITE WEAK MID-LVL FLOW...MDT INSTBY MAY BE
SUFFICIENT TO SUPPORT TSTM ORGANIZATION. GIVEN XPCD DRY AIR ATOP
DP MOIST LYR...LRG HAIL AND DMGG WIND GUSTS BOTH WILL BE PSBL FROM
ANY TSTMS.
MRNG CLD CVR WILL RESTRICT HEATING INITIALLY. BUT OVNGT MINIMA IN
THE 70S WILL OFFER A HEAD START TO MAXIMA IN THE LWR 80S-MID 80S
FOR TMW.
PWATS WILL RMN QUITE HIGH THRU WED NGT...PSBLY APRCHG 2.0 IN. SUCH
VALUES ARE MORE THAN 2 STANDARD DEVIATIONS ABV NRML VALUES AND
WILL ENCOURAGE VERY HIGH PCPN RATES IN TSTMS. FLASH FLOOD WATCH
CONTS THRU WED NGT DURG THIS PD OF HIGH PWATS.
CDFNT WILL PROGRESS THRU FCST AREA WED NGT...LKLY PROVIDING
ADDITIONAL FOCUSED PCPN WED EVE. PCPN WILL SHIFT SEWD OVNGT AND
SHOULD VACATE THE FCST AREA BY MID-MRNG THU.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MODELS ARE NOW IN BETTER AGREEMENT BUILDING IN HIGH PRESSURE FOR
THE WEEKEND. THIS WOULD MEAN DRY AND COMFORTABLE CONDITIONS FOR
MUCH OF THE LONG TERM.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SHOWER AND THUNDERSTORM COVERAGE WILL EXPAND THROUGH THE EVENING
HOURS. CIGS AND VIS SHOULD STAY IN THE MVFR/VFR RANGE. IF A
TERMINAL IS IMPACTED BY A SHOWER OR STORM THEN A BRIEF PERIOD OF
IFR VIS / CIGS ARE POSSIBLE.
MVFR FG IS POSSIBLE OVERNIGHT THROUGH MID MRNG WED GIVEN HOW MUCH
MOISTURE RESIDES IN THE LLVLS. SHOWERS AND THUNDERSTORMS WILL BE
NUMEROUS WED WITH IFR CONDITIONS EXPECTED FOR A BRIEF PERIOD.
OUTLOOK.../21Z WEDNESDAY THROUGH SUNDAY/...
IFR WEATHER IS POSSIBLE AGAIN THURSDAY IN SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH A COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH LATE
WEDNESDAY NIGHT FOR MDZ001.
OH...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH LATE
WEDNESDAY NIGHT FOR OHZ039>041-049-050-059.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR OHZ048-057-
058-068-069.
PA...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH LATE
WEDNESDAY NIGHT FOR PAZ020-021-029-031-073>076.
WV...FLASH FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH LATE
WEDNESDAY NIGHT FOR WVZ001>004-023-041.
FLASH FLOOD WATCH THROUGH LATE WEDNESDAY NIGHT FOR WVZ012-021-
022.
&&
$$
SYNOPSIS...34
NEAR TERM...98/34
SHORT TERM...KRAMAR
AVIATION...98/34
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT TUE JUL 9 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE JUL 9 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS WITH SEVERAL UPSTREAM SHORTWAVE TROUGHS. THE MOST
PROMINENT SHRTWV WAS LOCATED OVER ERN MT WHILE A WEAKER IMPULSE AND
ASSOCIATED MCS WAS MOVING THROUGH ERN SD. AT THE SFC...A WEAK
FRONTAL BOUNDARY LINGERED ACROSS SRN WI WHILE A STRONGER COLD FRONT
AHEAD OF THE MT SHRTWV EXTENDED FROM NW ONTARIO INTO NRN ND. A WEAK
RIDGE EXTENDED FROM QUEBEC ACROSS LAKE SUPERIOR RESULTING IN
LIGHT/CALM WINDS OVERNIGHT. AREAS OF FOG...LOCALLY DENSE...HAS
DEVELOPED AS ABUNDANT LOW LEVEL MOISTURE LINGERED BELOW AN INVERSION
ABOVE 850 MB.
EXPECT THAT THE MORNING WILL BE DOMINATED BY LOW CLOUDS BUT WITH
DAYTIME HEATING/MIXING THE LOW CLOUDS ACROSS MOST OF THE AREA WILL
THIN OUT ENOUGH BY THIS AFTERNOON FOR TEMPERATURES TO CLIMB INTO THE
LOWER 80S INLAND. SATELLITE TRENDS...SHORTER TERM MODELS AND CAPE
GRADIENT...SUGGEST THAT THE ERN SD MCS WILL TRACK TO THE EAST INTO W
AND SRN WI.
THERE IS SOME UNCERTAINTY REGARDING THE IMPACTS OF THE MCS ON
CONVECTION DEVELOPING FARTHER TO THE NORTH. THE FORCING ASSOCIATED
WITH THE APPROACHING NRN PLAINS SHRTWV WITH 100M HEIGHT FALLS AND
MODERATE 700-300 QVECTOR CONV WILL ALSO BE STRONGEST TO THE NORTH OF
THE CWA. HOWEVER...THE SRN END OF THE SHRTWV SHOULD STILL BE STRONG
ENOUGH TO SUPPORT SCT SHRA/TSRA MOVING FROM NW WI INTO WRN UPPER MI
THIS AFTERNOON AND THROUGH THE REST OF THE CWA THIS EVENING.
EXPECTED MAX TEMPS AND DEWPOINTS INTO THE MID TO UPPER 60S GIVE CAPE
VALUES INTO THE 1K-2K J/KG RANGE...GREATEST WEST CENTRAL. 0-6KM BULK
SHEAR VALUES IN THE 30-35 KNOT RANGE WILL BE MARGINAL FOR STRONG/SVR
ORGANIZED CONVECTION BUT WITH TSRA MOVING THROUGH DURING PEAK
HEATING GIVING DCAPE VALUES IN THE 500-1000 J/KG RANGE...SOME
ISOLATED STRONG/DAMAGING WIND GUSTS MAY BE POSSIBLE WITH ANY
STRONGER STORMS. THE HIGHER PROBABILITIES FOR SVR STORMS REMAINS TO
THE SOUTH WHERE THE INSTABILITY IS GREATEST...PER SPC DAY1 OUTLOOK.
THE SHRA/TSRA ARE EXPECTED TO PROGRESS THROUGH THE AREA MOVING INTO
THE ERN CWA LATE THIS EVENING AND ENDING OVERNIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 408 PM EDT TUE JUL 9 2013
SFC HIGH PRESSURE WILL MAKE ITS WAY OVER UPPER MICHIGAN FOR THURSDAY
AND FRIDAY...KEEPING WEATHER QUIET FOR THE START OF THE LONG TERM.
WITH 850MB TEMPS 12-15C EXPECT AFTERNOON HIGHS ON THURSDAY AND
FRIDAY TO BE IN THE UPPER 70S AND LOW 80S INLAND. ADDITIONALLY...DRY
AIR ASSOCIATED WITH THIS HIGH /PWATS ROUGHLY 60 PERCENT OF NORMAL/
WILL BRING A NICE BREAK TO THE STICKY HUMID CONDITIONS WEVE
EXPERIENCED THIS PAST WEEK. THOUGH IT WILL BE DRY AND WARM...WITH
THE RIDGE OVERHEAD WINDS WILL REMAIN VERY LIGHT.
THE NEXT CHANCE FOR PRECIPITATION COMES SATURDAY MORNING AND THROUGH
THE FIRST PORTIONS OF THE WORK WEEK. THE SFC HIGH PRESSURE SYSTEM
OVER THE GREAT LAKES SINKS SOUTHEASTWARD TOWARDS THE MID ATLANTIC
STATES AND A LOW PRESSURE SYSTEM MOVES ACROSS THE CANADIAN
PRAIRIE...DRAGGING A WEAK TROUGH ACROSS THE AREA DURING THE DAY
SATURDAY. MODELS HAVE COME INTO DECENT AGREEMENT THROUGH SATURDAY
EVENING...WITH ALL BRINGING PRECIPITATION AHEAD OF THE COLD FRONT
INTO THE WESTERN CWA BY APPROX 12Z SATURDAY MORNING. PWATS AHEAD OF
THE FRONT REACH UP TO 190 PERCENT OF NORMAL AND MUCAPE VALUES ARE
GENERALLY 300-700 J/KG IN THE 12Z SAT-00Z SUN TIME FRAME...AGAIN
MAINLY OVER THE WEST AND CENTRAL PORTIONS OF UPPER MI.
MEANWHILE...THE EASTERN U.P. FOR THE MOST PART REMAINS UNDER THE
INFLUENCE OF A RIDGE EXTENDING FROM THE HIGH PRESSURE THAT SETTLED
OVER THE MID ATLANTIC STATES. BOTH THE GFS/ECMWF HAVE THE RIDGE
STALLING THE EASTWARD PROGRESSION OF THE FRONT UNTIL SUNDAY
NIGHT-MONDAY WHEN A STRONGER SHORTWAVE FORCES IT EASTWARD THROUGH
THE CWA.
DISCREPANCIES AMONGST THE MODELS SHOW UP LATE SATURDAY NIGHT
INTO SUNDAY AS 500MB HIGH PRESSURE SPRAWLS OVER THE CENTRAL CONUS.
CONVECTION DEVELOPS ALONG THE EDGE OF THIS RIDGE UNDER THE MORE
ZONAL FLOW AT 500MB OVER THE NORTHERN PLAINS AND UPPER MICHIGAN. AS
OF NOW...THE ECMWF HAS THE BULK OF THE PRECIPITATION OVER UPPER MI
ALONG WITH A MORE DEFINED SHORTWAVE....HOWEVER THE GFS HAS IT MOVING
FURTHER SOUTH ACROSS MAINLY WI/ALONG THE WI BORDER WITH A LESS
DEFINED SHORTWAVE. OVERALL LOW CONFIDENCE IN MUCH OF ANYTHING THIS
FAR OUT AS WHERE/WHEN CONVECTION DEVELOPS OVER THE NORTHERN PLAINS
AND HOW IT EVOLVES WILL GREATLY INFLUENCE THE FORECAST. KEPT POPS
SIMILAR TO PREVIOUS FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 408 PM EDT TUE JUL 9 2013
THE MAIN ISSUES DURING THIS TAF PERIOD WILL BE FOCUSED ON TS CHANCES
THIS AFTERNOON WITH MVFR TO IFR CONDITIONS DEVELOPING OVERNIGHT.
HAVE PLACED VCTS IN THE IWD TAF AT THE BEGINNING OF THE TAF PERIOD
WITH THUNDERSTORMS APPROACHING THE AREA FROM THE SOUTH. CURRENT
THINKING IS THAT THIS WILL BE THE MAIN AREA OF CONVECTION THIS
AFTERNOON...SHIFTING EASTWARD TO SAW BY 21Z. CMX MAY MISS OUT ON
MOST OF THE CONVECTION DUE TO LINGERING CLOUD COVER AN GREATER
STABILITY. CEILING AND VISIBILITY WILL LOWER THIS EVENING THROUGH
MUCH OF TONIGHT AHEAD OF THE APPROACHING COLD FRONT. IT WOULD NOT BE
OUT OF THE QUESTION FOR A FEW RUMBLES OF THUNDER NEAR THE IWD AND
SAW TAF SITE BEFORE FROPA...BUT DO NOT EXPECT WIDE SPREAD
THUNDERSTORM ACTIVITY. ONCE FRONT PASSES CEILINGS AND VISIBILITY
WILL IMPROVE TO VFR CONDITIONS NEAR DAY BREAK WEDNESDAY. WINDS MAY
BECOME A BIT GUST BEHIND THE COLD FRONT THROUGH THE DAY
WEDNESDAY...WITH GUSTS REACHING NEARLY 25 KNOTS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT TUE JUL 9 2013
DENSE FOG REMAINS A CONCERN ACROSS LAKE SUPERIOR TODAY.
CLEARING SKIES FOR TUESDAY MORNING SHOULD ALLOW ENOUGH HEATING TO
MIX OUT THE MOST DENSE FOG DURING THE AFTERNOON...AT LEAST CLOSER TO
THE SHORE. PATCHY FOG WILL THEN LINGER INTO WEDNESDAY BEFORE A COLD
FRONT BRINGS DRIER AIR FROM WEST TO EAST ACROSS THE LAKE. WINDS
SHOULD BE LIGHT AND GENERALLY VARIABLE THROUGH TUESDAY EVENING.
THEN...EXPECT WINDS TO VEER TO THE NW AT 15 TO 25 KNOTS...MAINLY
ACROSS THE EAST HALF OF THE LAKE...FOR LATE TUESDAY NIGHT THROUGH
WEDNESDAY. HIGH PRESSURE WILL THEN BUILD INTO THE AREA THURSDAY
THROUGH SATURDAY AND BRING LIGHT WINDS UNDER 15 KNOTS FOR MUCH OF
THE TIME PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KEC
LONG TERM...MCD
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS GAYLORD MI
401 PM EDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 401 PM EDT TUE JUL 9 2013
CHANCES OF RAIN SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT INTO
WEDNESDAY MORNING AS A COLD FRONT APPROACHES THE REGION. BEHIND THE
FRONT...HIGH PRESSURE WILL BEGIN TO BUILD IN BY LATE
WEDNESDAY...BRINGING COOLER AND LESS HUMID CONDITIONS FOR MIDWEEK. A
WARMING TREND WILL THEN FOLLOW FOR LATE IN THE WEEK INTO THE
UPCOMING WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 401 PM EDT TUE JUL 9 2013
AN ADMITTEDLY FRUSTRATING FORECAST THIS EVENING...WITH CONFIDENCE
DWINDLING ABOUT THE POTENTIAL FOR CONVECTION ACROSS THE CWA...
DESPITE WHAT SHOULD (THEORETICALLY AT LEAST) BE A DECENT SETUP.
EARLY AFTERNOON ANALYSIS REVEALS A PAIR OF SHORTWAVES TRAVERSING A
SEASONABLY STRONG JET STREAM FLOW ACROSS THE NORTHERN TIER...WITH
THE FIRST OF THESE WAVES JUST NOW ENTERING WESTERN WISCONSIN. THIS
FEATURE HAS BEEN RESPONSIBLE FOR A RATHER LONG-LIVED AXIS OF
CONVECTION ALL ACROSS THE UPPER MIDWEST OVER THE PAST 12
HOURS...WITH THIS ACTIVITY JUST NOW WORKING ACROSS SOUTHERN LAKE
MICHIGAN. THE AIRMASS ACROSS NORTHERN LOWER REMAINS STUBBORNLY
CAPPED THANKS TO A WARM NOSE UP AROUND 750MB PER BOTH RUC AND
OBSERVED SOUNDINGS...WITH EARLIER THICK CLOUD COVER EFFECTIVELY
LIMITING HEATING AND THUS INSTABILITY. ALL THE WHILE...THE BEST
BOUNDARY LAYER MOISTURE REMAINS LAID OUT OVER THE SOUTHERN LAKES
ALONG A SUBTLE WARM FRONT...WITH MUCAPE VALUES OF 1500-3000 J/KG
NOTED IN THE VICINITY OF THIS FEATURE. NOT SURPRISINGLY...CONVECTION
IS DOING THE FAMOUS NORTHERN MICHIGAN SPLIT AS OUR AIRMASS IS JUST
PLAIN GARBAGE...FOR LACK OF A BETTER TERM...FEATURING ONLY MUCAPE
VALUES PERHAPS PUSHING 700J/KG AT BEST AND THE AFOREMENTIONED CAP.
MEANWHILE...A SECONDARY/STRONGER UPPER WAVE IS NOTED DIVING INTO THE
NORTHERN PLAINS...HERALDING THE ARRIVAL OF A MUCH COOLER AIRMASS...
WITH AN ASSOCIATED COLD FRONT DRAPED OVER NORTHWEST MINNESOTA AS OF
19Z.
INTO LATE AFTERNOON AND THE EVENING...APPROACH OF LEAD UPPER WAVE
WILL MANDATE AT LEAST A CONTINUED CHANCE FOR SHOWERS AND A FEW
STORMS...THOUGH HONESTLY JUST NOT FEELING ANY BIG RAIN CHANCES...AS
THE REAL BEEFY CONVECTION SHOULD GET GOING OVER THE SOUTHERN LAKES.
AS SUCH...AND GIVEN RADAR TRENDS AND STRONG LACK OF ANY UPSTREAM
ADDITIONAL ACTIVITY (JUST SOME FLAT CU ACROSS WISCONSIN)...HAVE TO
BELIEVE SCATTERED ACTIVITY WILL JUST ABOUT DO IT...AS PERHAPS WE MAY
GET LUCKY ENOUGH TO BUBBLE UP A FEW ADDITIONAL SHOWERS WITH THE
INCOMING VORT. NO SEVERE WX THREAT WITH EFFECTIVE SHEAR ONLY ABOUT
20 KNOTS.
A BIGGER QUESTION COMES TONIGHT AS THE SECONDARY TROUGH AND COLD
FRONT ARRIVE. IT WOULD BE NICE TO SEE AT LEAST A LITTLE UPSTREAM
ACTIVITY WITH THIS FEATURE...BUT ALAS THERE IS NOTHING AT THE
MOMENT...WITH NOTABLE CAPPING IN PLACE BEHIND THE LEAD WAVE. STILL
NOT OUT OF THE QUESTION SOME SHOWERS OR A STORM COULD DEVELOP WITH
THE UPPER TROUGH THROUGH THE EVENING...PERHAPS PUSHING INTO OUR AREA
OVERNIGHT. HAVING SAID THAT...CONFIDENCE IS LOW ENOUGH TO JUST
BARELY MAINTAIN SOME CHANCE POPS AT THIS POINT...WITH MAYBE A FEW
LINGERING SHOWERS INTO WEDNESDAY MORNING ACROSS EASTERN COUNTIES.
FAIRLY LIGHT FLOW IN ADVANCE OF AND SHALLOW NATURE OF INITIAL COLD
FRONT MAY AGAIN ALLOW FOR LOW CLOUDS AND SOME FOG TO DEVELOP
OVERNIGHT...PARTICULARLY AS THE FLOW VEERS MORE WESTERLY AND TRIES
TO PUSH LAKE MICHIGAN GRUNGE BACK ON LAND.
WEDNESDAY NOT LOOKING TOO BAD...WITH ANY PRECIP THREAT DONE BY
15Z...BUT PROBABLY SOME PESKY CU/STRATOCU AS MUCH COLDER AIR BLEEDS
IN ALOFT. TEMPS NOTABLY COOLER...WITH HUMIDITY LEVELS DIVING AS DEW
POINTS MIX INTO THE 50S. COOLER WITH HIGHS MAINLY IN THE 70S...BUT
COULD SNEAK IN A FEW LOW 80S SOUTHEAST COUNTIES ON A GUSTY NORTHWEST
FLOW...WITH WIND GUSTS UP TO 25 KNOTS EXPECTED.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 401 PM EDT TUE JUL 9 2013
RECENT TRENDS...TEMPERATURES: 1-3C ABOVE NORMAL OVER THE LAST WEEK
WITH MOST RECENT WARM SPELL...STATE HAS BEEN MOSTLY SPLIT BETWEEN
ABOVE NORMAL TEMPERATURES NORTH AND COOLER TEMPERATURES OVER
SOUTHERN LOWER WHICH IS THE NORTHERN EXTENT OF A LARGER AREA OF
BELOW NORMAL TEMPERATURES TO START JULY ACROSS THE MID/LOWER
MISSISSIPPI VALLEY/OHIO VALLEY AND INTO THE SOUTHEAST THANKS TO
RECENT HEAVY RAINFALL. PRECIPITATION/HYDROLOGY: BAND OF MUCH
NEEDED RAINFALL YESTERDAY BETWEEN THE M-32 AND M-55 CORRIDORS WITH
WIDESPREAD 0.50+ INCH AMOUNTS AND AREAS OF 1-2 INCH AMOUNTS.
EASTERN UPPER/TIP OF THE MITT STILL DRY THOUGH...LAST MEASURABLE
PRECIP IN THE SAULT WAS JUNE 28. 30 DAY STANDARDIZED PRECIP INDEX
CONTINUES ON A DRIER TRENDS ESPECIALLY ACROSS EASTERN UPPER.
NORTHERN MICHIGAN SOIL MOISTURE CONTINUES TO DRY OUT (STILL NEAR
NORMAL...ABOVE NORMAL NOW CONFINED TO CENTRAL/SOUTHERN LOWER
MICHIGAN). SEVEN DAY MEAN DISCHARGE ON AREA RIVERS MOSTLY NEAR
NORMAL. LATEST GREAT LAKES LEVELS FORECAST FROM THE ARMY CORPS
SHOWS LAKES MICHIGAN/HURON CURRENTLY ABOUT 2 FEET BELOW NORMAL...
WITH LITTLE IMPROVEMENT FORECAST THROUGH THE FALL.
LARGE SCALE PATTERN/FORECAST...FLAT/EXPANSIVE RIDGE SPANS THE
SOUTHERN CONUS AND EXTENDS EAST ACROSS THE SUBTROPICAL ATLANTIC TO
THE IBERIAN PENINSULA. MAINLY ZONAL BAND OF WESTERLIES TO THE NORTH
OF THIS RIDGE CROSSING THE NORTHERN TIER OF STATES AND ACROSS THE
GREAT LAKES...ALL PART OF A LOW AMPLITUDE 4/5 WAVE HEMISPHERIC
PATTERN. SHORT WAVE TROUGH MOVING THROUGH THIS BAND OF WESTERLIES
ACROSS THE HIGH PLAINS TODAY IS FORECAST TO STRENGTHEN AS IT MOVES
INTO THE GREAT LAKES WEDNESDAY AND HOOKS UP WITH HIGH LATITUDE
TROUGHING OVER THE ARCTIC TO COOL THINGS OFF FOR A COUPLE OF DAYS.
THIS TROUGH WILL SERVE TO SPLIT THE SOUTHERN CONUS RIDGE...ALLOWING
HIGHER HEIGHTS TO CONSOLIDATE OVER THE CENTRAL/SOUTHERN PLAINS BY
FRIDAY (AND OPEN UP A CHANNEL TO DRAW TROPICAL CYCLONE "CHANTAL" TO
THE NORTHWEST TOWARD THE SOUTHEASTERN U.S.). RISING HEIGHTS APPEAR
TO BE IN THE OFFING FOR THE UPPER LAKES HEADING INTO THE WEEKEND AS
UPPER RIDGE AXIS POKES ITS WAY NORTHEAST...THEN PERHAPS SOME SORT OF
BOUNDARY THAT SETTLES IN EARLY NEXT WEEK WITH A FAIRLY STRONG HEIGHT
GRADIENT ACROSS CANADA.
FORECAST AREA SHOULD BE FIRMLY WITHIN POST-FRONTAL AIR MASS BY
WEDNESDAY EVENING AS NORTHWEST BOUNDARY LAYER FLOW PULLS COOLER/
DRIER AIR ACROSS THE UPPER LAKES. TRAILING SHORT WAVE TROUGH WILL
FOLLOW LATER WEDNESDAY NIGHT BUT HEIGHT RISES ALOFT AND RISING
SURFACE PRESSURES TO ARRIVE THURSDAY...WITH HIGH PRESSURE HOLDING ON
INTO FRIDAY. SO FORECAST CONCERNS IN THE NEAR TERM
WEDNESDAY NIGHT THROUGH FRIDAY...WEATHER: NOT MUCH AT THIS POINT.
SHORT WAVE TROUGH SWINGS THROUGH WEDNESDAY NIGHT...BUT MAY NOT HAVE
MUCH MORE THAN SOME MID CLOUD WITH IT. LOW LEVEL THERMAL TROUGH
WILL MOVE THROUGH LOWER MICHIGAN DURING THE FIRST HALF OF
THURSDAY...MAY ALLOW FOR SOME DIURNALLY FORCED CLOUDS TO POP ACROSS
INTERIOR NORTH CENTRAL/NORTHEAST LOWER. BEYOND THAT WEATHER
CONCERNS MINIMAL THURSDAY NIGHT (CHILLY) AND FRIDAY.
TEMPERATURES...WEDNESDAY NIGHT LOWS MAINLY IN THE 50S...HIGHS
THURSDAY PROBABLY A COUPLE DEGREES BELOW SEASONABLE NORMS (MOSTLY
70S). GOOD RADIATIONAL COOLING NIGHT IN STORE THURSDAY NIGHT...
FRIDAY MORNING LOWS DOWN IN THE 40S AS A RESULT. HIGHS FRIDAY
EXPECTED TO BE CLOSER TO NORMAL (UPPER 70S/LOWER 80S).
WINDS...NORTHWEST 10-15 TO START WEDNESDAY EVENING THEN DIMINISHING.
NORTH/NORTHWEST 5-15MPH DURING THE DAY THURSDAY THEN BECOMING MOSTLY
CALM THURSDAY NIGHT. FRIDAY WINDS SOUTH 5-10MPH EASTERN UPPER...
MOSTLY LIGHT/VARIABLE SOUTH OF THE BRIDGE WITH PREDOMINANT LAKE
BREEZE CIRCULATIONS RESULTING IN ONSHORE FLOW ALONG THE
LAKESHORES.
EXTENDED FORECAST (SATURDAY THROUGH TUESDAY)...WILL CONTINUE TO WARM
UP SATURDAY AND EXPECTING ANOTHER DRY DAY WITH HIGHS WELL INTO THE
80S. RAIN CHANCES MAY START TO INCREASE SATURDAY NIGHT INTO SUNDAY
ESPECIALLY FARTHER NORTH WHERE MAY SEE INCREASED FOCUS ALONG A LOW
LEVEL JET. AFTER THAT...HEIGHT FALLS SPREAD INTO CENTRAL/EASTERN
CANADA WITH AN ASSOCIATED FRONTAL BOUNDARY FORECAST TO GET STRETCHED
OUT IN THE VICINITY OF THE UPPER LAKES. WHETHER SAID BOUNDARY DROPS
IN CLOSE ENOUGH TO FOCUS SHOWER/THUNDERSTORM CHANCES EARLY NEXT WEEK
IS UNCERTAIN...MAY TRY TO GO DRY MONDAY AND START TUESDAY OUT WITH
SOME RAIN CHANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 106 PM EDT TUE JUL 9 2013
A VARIETY OF CONDITIONS WILL CONTINUE ACROSS THE TAF SITES THROUGH
LATE AFTERNOON...WITH THE WORST OF THEM AROUND KAPN WHERE IFR
STRATUS WILL GRADUALLY LIFT TO MVFR. WILL BE WATCHING A LINE OF
SHOWERS AND STORMS TRYING TO CROSS THE LAKE INTO LATE
AFTERNOON...AND SUSPECT THIS FEATURE HAS A GOOD CHANCE OF
SURVIVAL...SO HAVE PUSHED UP ARRIVAL TIME BY MANY HOURS...THOUGH
WITH PREDOMINANTLY VFR CONDITIONS EXPECTED (OUTSIDE OF SOME LOCAL
IFR FOR A FEW MINUTES IN HEAVY RAIN). NOT SURE IF WE WILL BE ABLE
TO KICK OFF ANYTHING ELSE OVERNIGHT AS A COLD FRONT
APPROACHES...BUT STARTING TO HAVE MY DOUBTS...SO WILL REMOVE ALL
PRECIP BY 03-06Z AT THE LATEST. INSTEAD...REMAINING MOIST AIRMASS
SHOULD GO INTO MORE FOG/STRATUS PRODUCTION...WITH THE EXPECTATION
OF MANY SITES ENDING UP IFR ONCE AGAIN. WINDS WILL BE LIGHT
THROUGH MUCH OF THE NIGHT...BUT SHIFT TO THE WEST AND BECOME GUSTY
UP TO 25 KNOTS ON WEDNESDAY.
&&
.MARINE...
ISSUED AT 401 PM EDT TUE JUL 9 2013
FAIRLY LIGHT AND VARIABLE FLOW WILL CONTINUE ON THE GREAT LAKES FOR
MUCH OF TONIGHT...AS AREAS OF FOG AND LOW CLOUDS ALSO PERSIST. WINDS
WILL SHIFT ABRUPTLY OUT OF THE WEST TO NORTHWEST ON WEDNESDAY...WITH
SMALL CRAFT ADVISORY CONDITIONS EXPECTED ACROSS PARTS OF THE
NEARSHORE WATERS...MAINLY THROUGH THE STRAITS AND ACROSS NORTHERN
LAKE HURON AND WHITEFISH BAY. THOSE GUSTY CONDITIONS WILL SLOWLY
ABATE INTO WEDNESDAY NIGHT...WITH AN EXTENDED PERIOD OF LIGHT WINDS
AND FAIRLY LOW WAVES FORESEEN TO WRAP UP THE WORK WEEK AS HIGH
PRESSURE DRIFTS OVER THE WATERS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...NTS
SHORT TERM...LAWRENCE
LONG TERM...JPB
AVIATION...LAWRENCE
MARINE...LAWRENCE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
126 PM EDT TUE JUL 9 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 335 AM EDT TUE JUL 9 2013
MOST OF THE DAY TODAY SHOULD SEE A GOOD DEAL OF SUNSHINE AND VERY
WARM AND HUMID TEMPERATURES AFTER MORNING LOW CLOUDS AND FOG
DISSIPATE. THERE WILL BE A SLIGHT CHANCE OF A STORM DURING THE
AFTERNOON HOURS. THE BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND
STORMS WILL COME TOWARD AND AFTER MIDNIGHT TONIGHT AS A WAVE OF LOW
PRESSURE MOVES THROUGH THE AREA.
THE CHANCE OF RAIN WILL DIMINISH THROUGH THE DAY ON WEDNESDAY AS A
COLD FRONT PUSHES SOUTH THROUGH THE AREA. TEMPERATURES WILL BE A BIT
COOLER WEDNESDAY AFTERNOON. EVEN COOLER TEMPERATURES AND DRY
CONDITIONS WILL BE FOUND FOR THE REMAINDER OF THE WEEK BEFORE WE
START TO WARM UP AGAIN THIS COMING WEEKEND.
&&
.UPDATE...
ISSUED AT 1236 PM EDT TUE JUL 9 2013
I HAVE UPDATED OUR GRIDS TO SPEED UP THE TIMING ON THE CONVECTION
ASSOCIATED WITH THE MAIN UPPER WAVE COMING THROUGH THE CWA TO THE
6 PM TO 10 PM TIME FRAME. THIS IS BASED ON TIMING THE WATER VAPOR
IMAGE LOOPS...THE TIMING ON THE 12Z NAM...GFS...RAP AND THE HRRR
AS FAR OUT AS IT GOES. BASED ON THE WATER VAPOR IMAGE LOOPS THE
BACK EDGE GETS TO THE LAKE SHORE BY 8 PM AND THE
JACKSON...LANSING...ALAMA AREA BY 10 PM. THIS SUGGESTS THE STORM
THREAT WILL BE LARGELY OVER BY 10 PM SO I HAVE LIKELY POPS DURING
6 PM TO 10 PM TIME FRAME BUT HAVE ONLY CHANCE POPS AFTER THAT THROUGH
8 AM WEDNESDAY. IF CURRENT TRENDS CONTINUE I WOULD LOWER THE POPS
AFTER MIDNIGHT TO BELOW 20 PERCENT.
THE LIFT IN THE DGZ ON THE RAP MODEL CONTINUES TO BE THE BEST
FEATURE THAT CORRELATES TO THE LOCATION OF THE LIGHTING TODAY.
THAT BRINGS THE MAIN LINE OF STORMS THROUGH THE CWA FROM 8 PM
(WEST CWA) TILL 10 PM (EAST CWA). HOWEVER THERE IS THE SUGGESTION
THERE COULD BE A FEW STORMS DEVELOPING ON THE WARM FRONT...WEST OF
JXN ALONG INTERSTATE 94 BY 4 PM. THOSE STORMS SHOULD HEAD
NORTHEAST TOWARD LANSING BY 5 TO 6 PM.
MODEL SOUNDING MLCAPES ARE FORECAST TO BE IN THE 1500 TO 3000
J/KG RANGE BUT THE DEEP LAYER SHEAR AHEAD OF THE FRONT IS UNDER 25
KNOTS SO I DO NOT EXPECT AN ORGANIZED SEVERE STORM OUTBREAK WITH
THIS....JUST SOME ISOLATED WIND DAMAGE REPORTS. WITH THE FREEZING
LEVEL NEAR 15,500 FT AND THE -20 NEAR 26,000 FT... HAIL WOULD BE
LESS OF A THREAT BUT THERE IS A FAIR AMOUNT OF CAPE IN THE -10 TO
-20C LAYER SO I CAN NOT TOTALLY RULE IT OUT.
WITH THE FASTER MOVEMENT OF THE SYSTEM TEMPERATURES MAY NOT GET TO
90 DEGREES AFTER ALL SINCE THE CLOUDS WILL BE MOVING IN SHORTLY
(BASED ON VISIBLE AND IR LOOPS). STILL WE SHOULD SEE MID TO UPPER
80S INLAND WITH NO PROBLEM.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN ISSUE IN THE SHORT TERM IS FOG THIS MORNING...THEN STORM
POTENTIAL AND SEVERE THREAT FOR LATE TODAY AND TONIGHT.
A FAIR AMOUNT OF FOG AND LOW CLOUDS HAVE DEVELOPED OVER THE NRN
SECTION OF THE CWFA EARLY THIS MORNING. SOME OF THIS IS STARTING TO
DEVELOP FURTHER SOUTH AS A WEAK SFC TROUGH CRAWLING SOUTH ACROSS THE
AREA IS LIKELY BEING OVERRUN A BIT JUST OFF THE SFC AND WITH THE
HUMID AIR MASS IN PLACE. WE DO EXPECT THAT THIS WILL DISSIPATE
DURING THE MID MORNING HOURS AS THE STRONG SUN ANGLE WORKS ON THE
SHALLOW LAYER OF MOISTURE.
WE EXPECT TO SEE A GOOD DEAL OF SUNSHINE AFTER THE LOW CLOUDS AND
FOG DISSIPATE. THE AREA WILL BE UNDER THE INFLUENCE OF SHORT WAVE
RIDGING ALOFT BETWEEN THE DEPARTING WAVE FROM YESTERDAY AND THE NEXT
WAVE EXPECTED TONIGHT. FCST SOUNDINGS SHOW A WARM LAYER BETWEEN
850-700MB THAT SHOULD CAP MOST IF NOT ALL CONVECTIVE DEVELOPMENT
THROUGH ALMOST 00Z. WE CAN NOT RULE OUT AN ISOLATED SHOWER/STORM
DEVELOPING ALONG A BOUNDARY LIKE A LAKE BREEZE. THAT SAID...THE LOW
LEVEL FLOW LOOKS FAIRLY DIVERGENT DURING THE DAY TODAY WHICH SHOULD
LIMIT ANY DEVELOPMENT ALSO.
THE AREA STILL LOOKS LIKE IT IS ON TRACK FOR A BATCH OF SHOWERS AND
STORMS TO MOVE THROUGH TONIGHT. THE BEST CHANCE WILL OCCUR ALONG AND
SOUTH OF INTERSTATE 96. OUR FOCUS IS ON THE SHORT WAVE PRODUCING
CONVECTION ACROSS THE DAKOTAS...AND THE EVENTUAL LLJ THAT IS
EXPECTED TO DEVELOP THIS EVENING/OVERNIGHT.
WE DO EXPECT THE SHORT WAVE TO MOVE INTO THE AREA TOWARD 06Z. IT
SEEMS THAT THE CONVECTION ACROSS THE DAKOTAS SHOULD SLOWLY MOVE
THROUGH THE DAY. WE COULD SEE IT INTENSIFY A BIT IN WISCONSIN THIS
AFTERNOON AS IT ENCOUNTERS BUILDING INSTABILITY THERE. THIS LINE
WILL LIKELY DIMINISH SOME AS IT HEADS TOWARD OUR CWFA TONIGHT WITH
THE LOSS OF DIURNAL INSTABILITY.
WHAT WE WILL SEE IS THE LLJ INCREASE A BIT AND THE NOSE BE AIMED AT
THE SRN HALF OF THE CWFA BY 06Z. THIS SHOULD HELP MAINTAIN A FAIRLY
DECENT AREA OF SHOWERS AND STORMS THAT WOULD LAST INTO THE DAYBREAK
HOURS ON WED BEFORE MOVING OUT. SEVERE THREAT DOES NOT SEEM VERY
IMPRESSIVE DUE TO THE LATE NIGHT TIME FRAME THE CONVECTION WOULD BE
MOVING IN. FCST SOUNDINGS INDICATE THAT THE CAPE IN THE -10 TO -30C
LAYER IS NOT REAL ABUNDANT. DEEP LAYER CLOUD LAYER SHEAR IS ON THE
LOWER SIDE AROUND 20-25 KNOTS OR SO. MOST OF THE STORMS WOULD BE
ELEVATED WITH SOME POSSIBILITY OF SOME WINDS MAKING IT DOWN WITH
SOME RESIDUAL LOW LEVEL INSTABILITY.
WE FEEL THAT IF THE STORMS MOVE THROUGH AS EXPECTED TONIGHT...MOST
OF THE CWFA WILL BE WORKED OVER ENOUGH FOR WED THAT THE THREAT OF
STORMS AND SEVERE WEATHER IS LOW. IT WILL TAKE A WHILE TO BUILD UP
THE INSTABILITY...AND THE FRONT SHOULD CLEAR THE CWFA BY PEAK
HEATING. THE BEST CHC FOR STORMS WILL BE DOWN SOUTH WHERE LOCATIONS
DO NOT SEE MCS ACTIVITY TONIGHT.
WE WILL SEE SKIES CLEAR THEN WED EVENING AND CONTINUE THROUGH THU AS
DRIER AND COOLER AIR MOVES IN. A SHORT WAVE DOES MOVE THROUGH FROM
THE NW ON THU...HOWEVER THE AIR SHOULD BE DRY ENOUGH AND WE WILL BE
ON THE DOWNSTREAM SIDE OF THE LONG WAVE RIDGE TO OUR WEST TO KEEP US
DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE ARRIVAL OF MID LEVEL RIDGING EARLY IN THE PERIOD SUPPORTS A DRY
PATTERN FOR THE REGION THEN. SUBSIDENCE IS SEEN ON BUFKIT OVERVIEWS
AND MOISTURE PROFILES REMAIN DRY THROUGH SAT. A WARM AIR ADVECTION
PATTERN SETS UP BY SUNDAY AND PWAT VALUES WILL BE ON THE INCREASE.
A WEAKENING SURFACE FRONT SLIPS DOWN FROM THE NORTHWEST SUNDAY NIGHT
INTO MONDAY. WITH SOME ELEVATED/SURFACE INSTABILITY ALONG OR AHEAD
OF THE FRONTAL ZONE...THERE COULD BE A FEW STORMS.
THE BELOW NORMAL TEMPERATURES TO START THE PERIOD TRANSITION TO
ABOVE NORMAL VALUES FOR THE END OF THE PERIOD. TEMPERATURE VALUES
AT 925 MB CLIMB INTO THE LOW TO MID 20 DEG C RANGE SUNDAY. WITH
SOME SUN...WE SHOULD EASILY REACH THE MID 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 126 PM EDT TUE JUL 9 2013
MAIN CONCERN IS TIMING THUNDERSTORMS THIS AFTERNOON. BELIEVE
STORMS WILL DEVELOP OVER THE NEXT H0UR ALONG AND SOUTH OF
INTERSTATE 94 AND SPREAD EAST-NORTHEAST...AFFECTING MAINLY THE
AZO...BTL...JXN TERMINALS.
A SECOND WAVE OF EASTWARD MOVING STORMS IS EXPECTED IN THE 00-03Z
TIMEFRAME. IT APPEARS THAT LOW CLOUDS WILL AGAIN BE A CONCERN
AFTER MIDNIGHT BEHIND THESE STORMS. ALTHOUGH NOT MENTIONED IN THE
TAFS...CLEARING OF LOW CLOUDS COULD BE FAIRLY RAPID LATE WEDNESDAY
MORNING.
&&
.MARINE...
ISSUED AT 335 AM EDT TUE JUL 9 2013
NO HEADLINES WILL BE ISSUED WITH THIS FCST PACKAGE...HOWEVER WE ARE
LOOKING AT FOG POTENTIAL THROUGH TONIGHT...ROUGH WEATHER TONIGHT
WITH A POSSIBLE ROUND OF STORMS...AND THEN SOME DECENT WINDS
POSSIBLE WED BEHIND THE FRONT.
THE LIGHT GRADIENT OVER THE LAKE THIS MORNING ALONG WITH THE HUMID
AIR MASS OVER THE SOMEWHAT COOL WATER IS LIKELY PRODUCING SOME FOG.
WEBCAMS SHOW SOME PLACES SEEING FOG WHILE OTHERS ARE NOT. WE DO NOT
FEEL CONFIDENT ENOUGH AT THIS TIME TO ISSUE A MARINE FOG ADVISORY...
HOWEVER IT IS SOMETHING WE WILL NEED TO MONITOR.
WINDS AHEAD OF THE WAVE MOVING IN TONIGHT WILL HAVE THE POTENTIAL TO
INCREASE THE WINDS AND WAVES SOME TONIGHT. THE BIGGER THREAT WILL
LIKELY BE THE STORMS THAT ARE ANTICIPATED. THE BEST WIND WILL COME
WITH ANY STORMS. A DECENT NW WIND COULD DEVELOP LATE WED AFTERNOON
BEHIND THE FRONT THAT PUSHES THROUGH. A SMALL CRAFT ADVISORY MAY BE
NEEDED FOR THAT PERIOD.
&&
.HYDROLOGY...
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN PERIOD OF CONCERN AS FAR AS HYDRO IS CONCERNED IS THE
TONIGHT PERIOD. WE WILL SEE PRECIPITABLE WATER INCREASE TO AROUND
2.00 INCHES THIS EVENING AHEAD OF THE WAVE THAT WILL MOVE THROUGH
THE AREA. THIS WILL PROVIDE THE POTENTIAL OF HEAVY DOWNPOURS ACROSS
THE AREA. WE DO NOT ANTICIPATE SIGNIFICANT WIDESPREAD ISSUES AS THIS
WAVE THAT MOVES THROUGH SHOULD BE RATHER PROGRESSIVE. AMOUNTS WILL
LIKELY BE A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL FOR
BASIN AVERAGES...WITH SOME LOCAL AREAS SEEING 1-2 INCHES OF RAIN.
URBAN AND SMALL STREAM ISSUES WILL BE THE MAIN THREAT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...TJT
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
117 PM EDT TUE JUL 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 525 AM EDT TUE JUL 9 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS WITH SEVERAL UPSTREAM SHORTWAVE TROUGHS. THE MOST
PROMINENT SHRTWV WAS LOCATED OVER ERN MT WHILE A WEAKER IMPULSE AND
ASSOCIATED MCS WAS MOVING THROUGH ERN SD. AT THE SFC...A WEAK
FRONTAL BOUNDARY LINGERED ACROSS SRN WI WHILE A STRONGER COLD FRONT
AHEAD OF THE MT SHRTWV EXTENDED FROM NW ONTARIO INTO NRN ND. A WEAK
RIDGE EXTENDED FROM QUEBEC ACROSS LAKE SUPERIOR RESULTING IN
LIGHT/CALM WINDS OVERNIGHT. AREAS OF FOG...LOCALLY DENSE...HAS
DEVELOPED AS ABUNDANT LOW LEVEL MOISTURE LINGERED BELOW AN INVERSION
ABOVE 850 MB.
EXPECT THAT THE MORNING WILL BE DOMINATED BY LOW CLOUDS BUT WITH
DAYTIME HEATING/MIXING THE LOW CLOUDS ACROSS MOST OF THE AREA WILL
THIN OUT ENOUGH BY THIS AFTERNOON FOR TEMPERATURES TO CLIMB INTO THE
LOWER 80S INLAND. SATELLITE TRENDS...SHORTER TERM MODELS AND CAPE
GRADIENT...SUGGEST THAT THE ERN SD MCS WILL TRACK TO THE EAST INTO W
AND SRN WI.
THERE IS SOME UNCERTAINTY REGARDING THE IMPACTS OF THE MCS ON
CONVECTION DEVELOPING FARTHER TO THE NORTH. THE FORCING ASSOCIATED
WITH THE APPROACHING NRN PLAINS SHRTWV WITH 100M HEIGHT FALLS AND
MODERATE 700-300 QVECTOR CONV WILL ALSO BE STRONGEST TO THE NORTH OF
THE CWA. HOWEVER...THE SRN END OF THE SHRTWV SHOULD STILL BE STRONG
ENOUGH TO SUPPORT SCT SHRA/TSRA MOVING FROM NW WI INTO WRN UPPER MI
THIS AFTERNOON AND THROUGH THE REST OF THE CWA THIS EVENING.
EXPECTED MAX TEMPS AND DEWPOINTS INTO THE MID TO UPPER 60S GIVE CAPE
VALUES INTO THE 1K-2K J/KG RANGE...GREATEST WEST CENTRAL. 0-6KM BULK
SHEAR VALUES IN THE 30-35 KNOT RANGE WILL BE MARGINAL FOR STRONG/SVR
ORGANIZED CONVECTION BUT WITH TSRA MOVING THROUGH DURING PEAK
HEATING GIVING DCAPE VALUES IN THE 500-1000 J/KG RANGE...SOME
ISOLATED STRONG/DAMAGING WIND GUSTS MAY BE POSSIBLE WITH ANY
STRONGER STORMS. THE HIGHER PROBABILITIES FOR SVR STORMS REMAINS TO
THE SOUTH WHERE THE INSTABILITY IS GREATEST...PER SPC DAY1 OUTLOOK.
THE SHRA/TSRA ARE EXPECTED TO PROGRESS THROUGH THE AREA MOVING INTO
THE ERN CWA LATE THIS EVENING AND ENDING OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE JUL 9 2013
AFTER A FEW DAYS OF WARM AND ACTIVE WEATHER WITH POCKETS OF HEAVY
RAIN OVER MAINLY WESTERN HALF OF CWA...DEVELOPING TROUGHING ALOFT
ACROSS THE GREAT LAKES AND SFC HIGH ON THE WESTERN EDGE OF THE
TROUGH ALOFT WILL BRING QUIET AND COOLER WEATHER MID TO LATE WEEK.
WARMER TEMPERATURES AND INCREASING SHRA/TSRA CHANCES RETURN FOR THE
WEEKEND AS UPPER HEIGHTS BECOME MORE ZONAL.
OVERALL AGREEMENT THAT BEST CHANCE OF SHRA/TSRA ON WEDNESDAY WILL
BE 12-15Z OVER THE FAR EASTERN CWA. STRONGER TSRA STILL POSSIBLE
WITH MUCAPE UP TO 800J/KG. BETTER SHOT FOR SVR WILL BE FARTHER
SOUTH OVER SOUTHERN WI/NORTHERN IL CLOSER TO WEST-EAST FRONTAL
BOUNDARY AND ON NORTHERN GRADIENT OF HIGHER MLCAPES OVR 1000J/KG.
ANY CHANCES OF SHRA/TSRA OVER EAST QUICKLY END THROUGH MORNING AS
STRONG DEEP LAYER Q-VECTOR DIVERGENCE/SUBSIDENCE SURGES ACROSS
UPPER GREAT LAKES. PRESSURE GRADIENT BRIEFLY BECOMES TIGHT BTWN
THE EXITING LOW PRESSURE TROUGH AND HIGH PRESSURE BUILDING OVER
THE PLAINS. EXPECT BRIEF BUILDING WAVES AND INCREASED SWIM RISK
FOR WEDNESDAY OVER THE LK SUPERIOR BEACHES OF ALGER COUNTY AS
WINDS WILL BE FROM THE WEST TO NORTHWEST. WINDS/WAVES AND
ASSOCIATED HIGHER SWIM RISK SUBSIDES BY LATE AFTN WITH LOSS OF
PRESSURE RISES AND TIGHTER PRESSURE GRADIENT.
HIGH PRESSURE REMAINS MAIN WEATHER FEATURE FOR THU/FRI. TEMPS MAY
DROP INTO THE LOW-MID 40S OVER INTERIOR COOL SPOTS ON THURSDAY NIGHT
WITH LGT SOUTHERLY FLOW AS RIDGE AXIS DRIFTS ACROSS. AIRMASS DOES
NOT APPEAR TO BE NEARLY COLD OR DRY ENOUGH FOR ANY FROST POTENTIAL.
HIGH TEMPS BOTH DAYS SHOULD TOP OUT IN THE MID-UPR 70S AWAY FROM THE
GREAT LAKES. MAY EVEN SEE A FEW SPOTS BACK NEAR 80 DEGREES BY
THURSDAY.
UNCERTAINTY ABOUNDS WITH TIMING AND EXTENT OF NEXT ROUND AND/OR
ROUNDS OF SHRA/TSRA THIS WEEKEND INTO NEXT MONDAY. ECMWF NORMALLY
LEADS WAY IN TERMS OF VERIFICATION...BUT BOY ARE ITS SOLUTIONS IN
THE LAST COUPLE DAYS QUITE INCONSISTENT IN TERMS OF TIMING FOR THE
WEEKEND SHRA/TSRA CHANCES. DOES SEEM LIKE ECMWF IS TRENDING TOWARD
SLOWER IDEA SHOWN BY GFS FOR ARRIVAL OF PRECIP FRIDAY NIGHT. WILL
START TO SHOW TREND OF CHANCE POPS ONLY OVER THE FAR WEST LATE ON
FRIDAY NIGHT WHILE IT STAYS MAINLY DRY ELSEWHERE. UPPER HEIGHTS
FLATTEN OUT SATURDAY ALLOWING SHORTWAVES AND MID-LEVEL WIND MAX TO
SLIDE ACROSS UPPER GREAT LAKES REGION. MAIN SFC LOW WILL BE WELL TO
NORTH CLOSER TO SHARPER TROUGH ALOFT...BUT SW LOW-LEVEL FLOW ALONG
WITH INCREASING MOISTURE AND BUILDING INSTABILITY JUST UPSTREAM
SHOULD RESULT IN AT LEAST A CHANCE OF SHRA/TSRA AHEAD OF SFC-H85
TROUGH THAT MOVES THROUGH BY SUNDAY MORNING. WITH WRLY FLOW
ALOFT...FRONT MAY END UP STALLING OUT LATER IN THE WEEKEND PROVIDING
A FOCUS FOR ADDITIONAL SHRA/TSRA. FOR MOST PART USED CONSENSUS
POPS...BUT DID INCREASE POPS SLIGHTLY OVER THE SOUTH AND EAST CWA
CLOSER TO EXPECTED POSITION OF FRONT PER WPC HAND DRAWN SFC PROGS.
BASED ON GENERAL S/SW GRADIENT FLOW AHEAD OF FRONT AND H85 TEMPS IN
THE MID TEENS...INCREASED TEMPS OVER CONSENSUS GUIDANCE. EXPECT MAX
TEMPS FRIDAY THROUGH SUNDAY IN THE MID-UPR 70S TO AS WARM AS MID
80S. IT WILL ALL DEPEND ON EXTENT OF CLOUDS AND SHRA/TSRA. AFTER MIN
TEMPS IN THE 40S AND 50S MUCH OF THIS WEEK...READINGS RETURN TO THE
WARMER/MUGGIER 60S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 116 PM EDT TUE JUL 9 2013
THE MAIN ISSUES DURING THIS TAF PERIOD WILL BE FOCUSED ON TS CHANCES
THIS AFTERNOON WITH MVFR TO IFR CONDITIONS DEVELOPING OVERNIGHT.
HAVE PLACED VCTS IN THE IWD TAF AT THE BEGINNING OF THE TAF PERIOD
WITH THUNDERSTORMS APPROACHING THE AREA FROM THE SOUTH. CURRENT
THINKING IS THAT THIS WILL BE THE MAIN AREA OF CONVECTION THIS
AFTERNOON...SHIFTING EASTWARD TO SAW BY 21Z. CMX MAY MISS OUT ON
MOST OF THE CONVECTION DUE TO LINGERING CLOUD COVER AND GREATER
STABILITY. CEILING AND VISIBILITY WILL LOWER THIS EVENING THROUGH
MUCH OF TONIGHT AHEAD OF THE APPROACHING COLD FRONT. IT WOULD NOT BE
OUT OF THE QUESTION FOR A FEW RUMBLES OF THUNDER NEAR THE IWD AND
SAW TAF SITE BEFORE FROPA...BUT DO NOT EXPECT WIDE SPREAD
THUNDERSTORM ACTIVITY. ONCE FRONT PASSES CEILINGS AND VISIBILITY
WILL IMPROVE TO VFR CONDITIONS NEAR DAY BREAK WEDNESDAY. WINDS MAY
BECOME A BIT GUST BEHIND THE COLD FRONT THROUGH THE DAY
WEDNESDAY...WITH GUSTS REACHING NEARLY 25 KNOTS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT MON JUL 8 2013
DENSE FOG REMAINS A CONCERN ACROSS LAKE SUPERIOR THROUGH TUESDAY
MORNING. LIGHT WINDS AND LITTLE AIR MASS MOVEMENT WILL ALLOW FOR THE
REDEVELOPMENT OF AREAS OF DENSE FOG OVERNIGHT. CLEARING SKIES FOR
TUESDAY MORNING SHOULD ALLOW ENOUGH HEATING TO MIX OUT THE MOST
DENSE FOG BY TUESDAY AFTERNOON. PATCHY FOG WILL THEN LINGER INTO
WEDNESDAY BEFORE A COLD FRONT BRINGS DRIER AIR FROM WEST TO EAST
ACROSS THE LAKE. WINDS SHOULD BE LIGHT AND GENERALLY VARIABLE
THROUGH TUESDAY EVENING. THEN...EXPECT WINDS TO VEER TO THE NW AT 15
TO 25 KNOTS...MAINLY ACROSS THE EAST HALF OF THE LAKE...FOR LATE
TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE WILL THEN BUILD INTO
THE AREA THURSDAY THROUGH SATURDAY AND BRING LIGHT WINDS UNDER 15
KNOTS FOR MUCH OF THE TIME PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KEC
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS GAYLORD MI
106 PM EDT TUE JUL 9 2013
.SYNOPSIS...
ISSUED AT 344 AM EDT TUE JUL 9 2013
THERE WILL BE SMALL CHANCES FOR POP UP SHOWERS AND THUNDERSTORMS
TODAY. BETTER CHANCES OF RAINFALL WILL OCCUR TONIGHT INTO WEDNESDAY
MORNING AS A COLD FRONT APPROACHES THE REGION. HIGH PRESSURE WILL
BEGIN TO BUILD IN BY LATE WEDNESDAY...BRINGING COOLER AND LESS HUMID
CONDITIONS FOR MIDWEEK. A WARMING TREND WILL THEN FOLLOW FOR LATE IN
THE WEEK INTO THE UPCOMING WEEKEND.
&&
.UPDATE...
ISSUED AT 106 PM EDT TUE JUL 9 2013
WELL...HERE WE GO WITH MORE SURPRISES. UPSTREAM CONVECTION IS WELL
AHEAD OF SCHEDULE AND IS HOLDING TOGETHER NICELY. MUCAPE VALUES
ARE ON THE RISE ACROSS SOUTHWEST PARTS OF THE CWA WHERE SUNSHINE
IS BREAKING OUT AND A WARM FRONT IS SLOWLY LIFTING NORTH. BASED ON
LATEST HRRR DATA (WHICH IS ITSELF ABOUT 3 HOURS TOO SLOW WITH
CURRENT ACTIVITY)...WILL NEED TO PUSH UP ARRIVAL TIME OF PRECIP
CHANCES ROUGHLY 20-23C ACROSS THE CWA. WITH THAT SAID...AM A
LITTLE LEARY THAT ACTIVITY MAY TEND TO FADE WITH EASTERN EXTENT
GIVEN LACK OF INSTABILITY ACROSS NORTHEAST LOWER (LOTS OF
REMAINING STRATUS)...BUT THAT`S MORE OF A VERY NEAR TERM ISSUE AS
WE START LOOKING AT THE OVERNIGHT FORECAST. SEVERE POTENTIAL VERY
LOW AT THIS TIME.
UPDATE ISSUED AT 953 AM EDT TUE JUL 9 2013
INTERESTING AND CHALLENGING FORECAST THROUGH LATE AFTERNOON AND
EVENING (SOUNDS LIKE THE TYPICAL NORTHERN MICHIGAN TAGLINE DOESN`T
IT?)...WITH FORECAST ISSUES CENTERED MAINLY ON CLOUD/FOG/TEMP
TRENDS THROUGH MUCH OF THE DAY...BUT SHIFTING TOWARD CONVECTIVE
CHANCES BY LATE AFTERNOON AND EVENING. FIRST OF ALL...WILL JUST
COME RIGHT OUT AND SAY THAT THIS REMAINS A FAIRLY LOW CONFIDENCE
FORECAST WITH REGARD TO ANY CONVECTIVE EVOLUTION LATER
TODAY...WITH EVEN LOWER CONFIDENCE ABOUT ANY SEVERE POTENTIAL.
HOWEVER...STARTING TO GET THE FEELING CONVECTION MAY TRY TO SNEAK
INTO THE PICTURE A LITTLE EARLIER THAN CURRENTLY EXPECTED. MORE ON
THAT BELOW...BUT FIRST THINGS FIRST...WE WILL CONTINUE TO DEAL
WITH WIDESPREAD STRATUS AND GRADUALLY LIFTING FOG THROUGH AT LEAST
LATE MORNING...AND PROBABLY A LITTLE BEYOND. 12Z APX RAOB TELLS
THE STORY...WITH A GOOD DEAL OF MOISTURE SANDWICHED BELOW
900MB...AND IN PARTICULAR BELOW 950MB...COURTESY OF A SHALLOW
INVERSION AND PLENTIFUL BOUNDARY LAYER MOISTURE FROM YESTERDAY`S
MUCH-NEEDED RAINFALL. BASED ON PAST EXPERIENCE...THIS GRUNGE WILL
TAKE SOME TIME TO MIX OUT...AND WILL PROBABLY TRANSITION FROM PURE
STRATUS TO A THICKER STRATOCU DECK AROUND MIDDAY (WON`T TAKE MUCH
TO CONVECTIVELY SATURATE THE 900MB LEVEL PER SOUNDING)...BEFORE
ERODING TO SOME DEGREE AS DRIER AIR ABOVE 875 ATTEMPTS TO MIX IN.
HOWEVER...SATELLITE ANALYSIS ALREADY SHOWING PLENTY OF THICKER
DEBRIS CLOUDS MAKING INROADS THROUGH THE WESTERN LAKES...SO HAVE
TO BELIEVE THINGS WILL CLOUD BACK UP FAIRLY QUICKLY ACROSS THE
WESTERN CWA THROUGH MID AND LATE AFTERNOON. THIS MAKES TEMPS
TRICKY...AND IN GENERAL GUT FEELING SAYS TO LOWER AT LEAST A
COUPLE OF DEGREES...THOUGH WITH THE CAVEAT THAT IT DOESN`T TAKE
MUCH SUN TO SEND READINGS SOARING THIS TIME OF YEAR.
AS FOR PRECIP CHANCES...NOTHING DOING THROUGH AT LEAST 19-21Z...AS
STOUT CAPPING AROUND 750MB AND STUBBORNLY SLOW WARMING (AT LEAST
INITIALLY) WORK IN TANDEM...COUPLED WITH SUBTLE SHORTWAVE
RIDGING ALOFT/NO FORCING. HOWEVER...REALLY WATCHING UPSTREAM
CONVECTIVE ACTIVITY...TIED TO A LEADING SHORTWAVE TRAVERSING
WESTERN MINNESOTA...OUT AHEAD OF THE MAIN UPPER TROUGH AMPLIFYING
INTO THE NORTHERN PLAINS. PER RADAR TRENDS AND SHORT TERM GUIDANCE
HINTS...REALLY STARTING TO GET THE FEELING THAT SOME OF THIS
ACTIVITY SLIDING EAST FROM NORTHERN IOWA MAY TRY TO IMPACT PARTS
OF THE SOUTHERN CWA BY LATE AFTERNOON OR EARLY EVENING. ACTIVITY
IS CURRENTLY TRYING TO OUTRUN THE BETTER INSTABILITY...HOWEVER...
THIS WON`T BE THE CASE FOR LONG AS STRENGTHENING SOUTHERN FLOW
AHEAD OF THE WAVE IS PROGGED TO HELP LIFT A SUBTLE WARM FRONT BACK
NORTH INTO CENTRAL WISCONSIN AND EVENTUALLY PARTS OF NORTHERN
MICHIGAN. THERE ARE INCREASING HINTS OF BETTER POOLED MOISTURE
ALONG THIS BOUNDARY (SEE UPSTREAM DEW POINTS OVER THE SOUTHERN
LAKES IN THE LOW 70S)...WHICH COMBINED WITH AT LEAST A LITTLE
DAYTIME HEATING AND SUBTLE MID LEVEL HEIGHT FALLS MAY BE ENOUGH TO
SUSTAIN THE WARM ADVECTION WING COMPONENT OF THE CURRENT LARGER
UPSTREAM MCS.
LATEST HRRR GUIDANCE REALLY PICKING UP ON THIS IDEA AND GIVEN
CURRENT RADAR MOSAIC...KIND OF HARD TO ARGUE AT THE MOMENT. THIS
IS ESPECIALLY TRUE WITH FURTHER HINTS THAT A LOCALIZED LOW LEVEL
JET MAXIMUM MAY ALSO POKE INTO THE SOUTHWEST CWA OFF LAKE
MICHIGAN...COINCIDENT WITH THE ARRIVAL OF SOMEWHAT BETTER MID
LEVEL LAPSE RATES (STILL NOTHING STELLAR) AND BETTER LOW LEVEL
THETA-E RIDGING. HAVE RE-WORKED POPS TO SHOW THIS IDEA BETTER.
DON`T ANTICIPATE A BIG SEVERE THREAT THROUGH 00Z WITH RATHER SLACK
WIND FIELDS (DEEP SHEAR ONLY ABOUT 20 KNOTS) AND LIMITED
INSTABILITY (MIXED LAYER CAPE UP AROUND 700 J/KG).
UPDATE ISSUED AT 629 AM EDT TUE JUL 9 2013
DENSE FOG HAS EXPANDED OVER THE LAST HOUR OR SO..AND AN SPS HAS
BEEN ISSUED FOR LESS THAN A QUARTER OF A MILE VISIBILITIES. THE
WORST OF VISIBILITY REDUCTION WAS FOCUSED IN THE COASTAL
COMMUNITIES SURROUNDING LAKES MICHIGAN AND HURON. TEMPERATURES
WILL BE AT A STAND-STILL FOR THE NEXT SEVERAL HOURS...AS THE
STRATUS WILL GO NOWHERE FOR MOST OF THE MORNING. THERE HAVE BEEN
NO RAIN SHOWERS FOR THE LAST SEVERAL HOURS...AND NEWER DATA COMING
IN...IF ANYTHING...SUGGEST MAYBE EVEN A STRONGER CAP TO PREVENT
AFTERNOON SHOWERS AND STORMS. WILL PLAY IT SAFE HERE THOUGH AND
KEEP SLIGHT CHANCES IN THE FORECAST...FOR THE MERE FACT THAT WE
WILL HAVE DEVELOPED LAKE BREEZES AND A PIECE OF SHORTWAVE ENERGY
THAT COULD POSSIBLY OVERCOME CAPPING...ALTHOUGH IT DOESN`T LOOK
LIKE IT. BELIEVE THERE WILL BE AFTERNOON SUN...EVENTUALLY FOR
TEMPERATURES TO MAKE IT INTO THE 80S....BUT WILL DROP EXPECTED
HIGHS A COUPLE DEGREES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 344 AM EDT TUE JUL 9 2013
CURRENTLY...WEAK LOW PRESSURE WAS WORKING EASTWARD ACROSS NE
LOWER...WITH SHOWER ACTIVITY VANISHING AFTER LOSS OF HEATING.
MOISTURE HAS BEEN STRIPPED OUT ALOFT AND THE BL REMAINS MOIST.
RADIATIONAL COOLING ON TOP OF THIS BL MOISTURE HAS RESULTED IN
WIDESPREAD STRATUS...AS FAR OUT AS WISCONSIN. THIS STRATUS WAS ALSO
UNDERNEATH A DEVELOPING CAP DUE TO SUBSIDENCE AND SFC HIGH PRESSURE
BETWEEN DEPARTING LOW...AND UPSTREAM NEXT LOW PRESSURE AND COLD
FRONT. THIS LOW WAS IN FAR NW ONTARIO...WITH ITS COLD FRONT DRAPED
DOWN THROUGH NORTH DAKOTA. THERE WAS RELATIVE DRY AIR AND NO PRECIP
YESTERDAY WITHIN THE HIGH PRESSURE.TEMPERATURES IN THE STRATUS HAS
FLAT-LINED...IN THE UPPER 60S FOR MOST.
TODAY...NEW DATA INDICATING THE BL MOISTURE IS QUITE MOIST AND THICK
ENOUGH FOR THE SOLID STRATUS TO CONTINUE WELL INTO THE MORNING. WILL
KEEP SKIES CLOUDY ALL MORNING...BEFORE HEATING CAN FINALLY RESULT IN
HOLES AND A PRETTY GOOD COVERAGE OF CUMULUS. THERE SEEMS TO BE QUITE
THE CHANGE IN EXPECTATIONS FOR PRECIPITATION DEVELOPMENT FOR THIS
AFTERNOON. A CAP DEVELOPS AT 750MB...VERIFIED BY 00Z UPSTREAM
SOUNDINGS ACROSS MINNEAPOLIS/GREEN BAY. USING A PARCEL OF 88/67 WILL
RESULT IN ROUGHLY 1400 J/KG SBCAPE AND ONLY A FEW HUNDRED J/KG
MLCAPE (WHICH MAY BE BETTER CONSIDERING THE DRYNESS OF THE ENTIRE
BL). THUS...CHANCES FOR SEEING ANY SORT OF DIURNAL SHOWERS AND
THUNDERSTORMS HAVE DRASTICALLY DWINDLED DUE TO A SIGNIFICANT AMOUNT
OF CAPPING/WARM AIR ALOFT. WILL JUST KEEP A 20 PERCENT CHANCE FOR
THE LATE AFTERNOON AND EVENING. HIGHS SHOULD MAKE A LATER DAY RUN AT
THE MIDDLE AND UPPER 80S.
TONIGHT...AFTER ANY DIURNAL CONVECTION WANES...WE WILL BE AWAITING
THE MAIN SHOW. THE FAR NRN ONTARIO LOW PRESSURE MOVES EAST AND THE
TRAILING COLD FRONT WILL BE MARCHING FROM FAR WESTERN WISCONSIN AND
INTO/NEAR EASTERN UPPER/LAKE MICHIGAN BY 12Z. STRONGER SHORTWAVE
ENERGY AND NICE UPPER DIVERGENCE SIGNAL WILL WORK IN CONCERT WITH
LOW LEVEL CONVERGENCE ASSOCIATED WITH THE FRONT...TO FIRE OFF
SHOWERS AND STORMS FOR THE OVERNIGHT. THESE STORMS WILL HAVE BEEN
GENERATED ACROSS WISCONSIN IN THE AFTERNOON...BUT EVEN WITH LOSS OF
HEATING...THE UPPER FORCING OUGHT TO SUSTAIN THUNDER. MUCAPES ARE
PRETTY MINIMAL...IN THE FEW HUNDREDS OR SO...AND WILL DOWNPLAY THE
AMOUNT OF THUNDER WITH THE RAIN SHOWERS. THE BETTER/DEEPER
INSTABILITY WILL BE WELL SOUTH OF US...IN HIGHER THETA-E AIR ACROSS
NRN IL/INDIANA. THE CONVECTION THERE MAY ALSO SERVE TO ROB US OF
SOME MOISTURE...ALTHOUGH PWATS ARE EXPECTED TO BE HIGH...1.80" TO
ALMOST 2.00" LIQUID. STRATUS AND FOG WILL ALSO BE A CONCERN IN JUICY
AIR MASS...BEFORE DRYING SETS IN ON WEDNESDAY. LOWS IN THE MID/UPPER
60S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 344 AM EDT TUE JUL 9 2013
AN UPPER LEVEL TROUGH IN PLACE WEDNESDAY INTO THURSDAY WILL LIFT OUT
OF THE REGION AS A LARGE UPPER LEVEL RIDGE CENTERED ACROSS THE
DESERT SOUTHWEST EXPANDS NORTHEAST INTO THE GREAT LAKES REGION
THURSDAY NIGHT INTO THE WEEKEND. ANOTHER TROUGH MOVING BY TO THE
NORTH WILL THEN BEAT DOWN THIS RIDGE EARLY NEXT WEEK. THIS SCENARIO
WILL RESULT IN COOLER TEMPERATURES FOR MIDWEEK FOLLOWED BY A WARMING
TREND FOR FRIDAY INTO THIS WEEKEND. MEANWHILE...THERE WILL BE MORE
CHANCES OF SHOWERS AND THUNDERSTORMS WEDNESDAY...FOLLOWED BY
PRECIPITATION FREE WEATHER INTO THE WEEKEND. THERE WILL BE SMALL
CHANCES FOR A FEW SHOWERS OR STORMS EARLY NEXT WEEK AS THE TROUGH
MOVES BY. THE MAIN LONG TERM FOCUS IS ON LINGERING POPS WEDNESDAY
THEN POPS AGAIN NEXT MONDAY.
WEDNESDAY...THE SURFACE COLD FRONT CONTINUES TO ADVANCE ACROSS THE
REGION FROM NORTHWEST TO SOUTHEAST WITH DRIER AIR ADVECTING IN
BEHIND IT. IN ADVANCE OF THE FRONT...THE NAM INDICATES 1000-1500
J/KG OF ML CAPE FROM GAYLORD SE TO GLADWIN THROUGH EARLY AFTERNOON.
HOWEVER...THE NAM IS THE MOISTEST MODEL BY FAR WITH THE GFS ET ALL
INDICATING LOTS OF DRY AIR ADVECTION (MEAN 1000-500 MB RH FALLING TO
ABOUT 40 PERCENT OR SO). THEREFORE WILL LEAVE POPS IN THE CHANCE
CATEGORY. POTENTIAL FOR SEVERE STORMS APPEARS LIMITED WITH LIGHT
WIND FIELDS ALOFT. HIGHS RANGING FROM AROUND 70 FAR NORTH TO THE
LOWER 80S SOUTHEAST.
THURSDAY THROUGH MONDAY...THE CORE OF THE UPPER LEVEL COOL POOL IS
OVERHEAD (850 MB TEMPS OF PLUS 8 TO 10 C) BUT FAIRLY DRY AIR (MEAN
1000-500 MB RH 30 TO 40 PERCENT) SHOULD INHIBIT DAYTIME HEATING
DRIVEN SHOWERS FROM FORMING. OTHERWISE...EXTENDED MODELS CONTINUE TO
BE IN GOOD AGREEMENT WITH RIDGING AT THE SURFACE AND SLOWLY BUILDING
HEIGHTS ALOFT LEADING TO ANOTHER PLEASANT AND INCREASINGLY WARM
STRETCH OF WEATHER INTO THE WEEKEND. AN UPPER LEVEL TROUGH AND
ASSOCIATED WEAK COLD FRONT WILL THEN BRING SMALL CHANCES FOR SHOWERS
OR THUNDERSTORMS EARLY NEXT WEEK. HIGHS THURSDAY IN THE MIDDLE TO
UPPER 70S...FRIDAY IN THE MIDDLE 70S TO LOWER 80S...WITH THE UPPER
70S TO MIDDLE 80S FOR SATURDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 106 PM EDT TUE JUL 9 2013
A VARIETY OF CONDITIONS WILL CONTINUE ACROSS THE TAF SITES THROUGH
LATE AFTERNOON...WITH THE WORST OF THEM AROUND KAPN WHERE IFR
STRATUS WILL GRADUALLY LIFT TO MVFR. WILL BE WATCHING A LINE OF
SHOWERS AND STORMS TRYING TO CROSS THE LAKE INTO LATE
AFTERNOON...AND SUSPECT THIS FEATURE HAS A GOOD CHANCE OF
SURVIVAL...SO HAVE PUSHED UP ARRIVAL TIME BY MANY HOURS...THOUGH
WITH PREDOMINANTLY VFR CONDITIONS EXPECTED (OUTSIDE OF SOME LOCAL
IFR FOR A FEW MINUTES IN HEAVY RAIN). NOT SURE IF WE WILL BE ABLE
TO KICK OFF ANYTHING ELSE OVERNIGHT AS A COLD FRONT
APPROACHES...BUT STARTING TO HAVE MY DOUBTS...SO WILL REMOVE ALL
PRECIP BY 03-06Z AT THE LATEST. INSTEAD...REMAINING MOIST AIRMASS
SHOULD GO INTO MORE FOG/STRATUS PRODUCTION...WITH THE EXPECTATION
OF MANY SITES ENDING UP IFR ONCE AGAIN. WINDS WILL BE LIGHT
THROUGH MUCH OF THE NIGHT...BUT SHIFT TO THE WEST AND BECOME GUSTY
UP TO 25 KNOTS ON WEDNESDAY.
&&
.MARINE...
ISSUED AT 344 AM EDT TUE JUL 9 2013
WINDS WILL CONTINUE TO BE VARIABLE AND LIGHT THROUGH TONIGHT UNDER
STABLE CONDITIONS ON THE LAKES. UPSTREAM COLD FRONT WILL APPROACH
OVERNIGHT AND INTO WEDNESDAY FOR SHOWERS AND STORMS...AND BEHIND THE
FRONT WINDS WILL SHIFT TO OUT OF THE NW. MAYBE HAVE SOME ADVISORY
LEVEL GUSTS AT PRESQUE ISLE...SSM/ST MARYS. WINDS WILL LIGHTEN UP
OVER TIME THEN...AS HIGH PRESSURE GRADUALLY WORKS IN OVER NRN
MICHIGAN LATE THIS WORK WEEK...AND THE WEEKEND.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...AS
SHORT TERM...SD
LONG TERM...AS
AVIATION...LAWRENCE
MARINE...SD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1236 PM EDT TUE JUL 9 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 335 AM EDT TUE JUL 9 2013
MOST OF THE DAY TODAY SHOULD SEE A GOOD DEAL OF SUNSHINE AND VERY
WARM AND HUMID TEMPERATURES AFTER MORNING LOW CLOUDS AND FOG
DISSIPATE. THERE WILL BE A SLIGHT CHANCE OF A STORM DURING THE
AFTERNOON HOURS. THE BETTER CHANCE OF MORE WIDESPREAD SHOWERS AND
STORMS WILL COME TOWARD AND AFTER MIDNIGHT TONIGHT AS A WAVE OF LOW
PRESSURE MOVES THROUGH THE AREA.
THE CHANCE OF RAIN WILL DIMINISH THROUGH THE DAY ON WEDNESDAY AS A
COLD FRONT PUSHES SOUTH THROUGH THE AREA. TEMPERATURES WILL BE A BIT
COOLER WEDNESDAY AFTERNOON. EVEN COOLER TEMPERATURES AND DRY
CONDITIONS WILL BE FOUND FOR THE REMAINDER OF THE WEEK BEFORE WE
START TO WARM UP AGAIN THIS COMING WEEKEND.
&&
.UPDATE...
ISSUED AT 1236 PM EDT TUE JUL 9 2013
I HAVE UPDATED OUR GRIDS TO SPEED UP THE TIMING ON THE CONVECTION
ASSOCIATED WITH THE MAIN UPPER WAVE COMING THROUGH THE CWA TO THE
6 PM TO 10 PM TIME FRAME. THIS IS BASED ON TIMING THE WATER VAPOR
IMAGE LOOPS...THE TIMING ON THE 12Z NAM...GFS...RAP AND THE HRRR
AS FAR OUT AS IT GOES. BASED ON THE WATER VAPOR IMAGE LOOPS THE
BACK EDGE GETS TO THE LAKE SHORE BY 8 PM AND THE
JACKSON...LANSING...ALAMA AREA BY 10 PM. THIS SUGGESTS THE STORM
THREAT WILL BE LARGELY OVER BY 10 PM SO I HAVE LIKELY POPS DURING
6 PM TO 10 PM TIME FRAME BUT HAVE ONLY CHANCE POPS AFTER THAT THROUGH
8 AM WEDNESDAY. IF CURRENT TRENDS CONTINUE I WOULD LOWER THE POPS
AFTER MIDNIGHT TO BELOW 20 PERCENT.
THE LIFT IN THE DGZ ON THE RAP MODEL CONTINUES TO BE THE BEST
FEATURE THAT CORRELATES TO THE LOCATION OF THE LIGHTING TODAY.
THAT BRINGS THE MAIN LINE OF STORMS THROUGH THE CWA FROM 8 PM
(WEST CWA) TILL 10 PM (EAST CWA). HOWEVER THERE IS THE SUGGESTION
THERE COULD BE A FEW STORMS DEVELOPING ON THE WARM FRONT...WEST OF
JXN ALONG INTERSTATE 94 BY 4 PM. THOSE STORMS SHOULD HEAD
NORTHEAST TOWARD LANSING BY 5 TO 6 PM.
MODEL SOUNDING MLCAPES ARE FORECAST TO BE IN THE 1500 TO 3000
J/KG RANGE BUT THE DEEP LAYER SHEAR AHEAD OF THE FRONT IS UNDER 25
KNOTS SO I DO NOT EXPECT AN ORGANIZED SEVERE STORM OUTBREAK WITH
THIS....JUST SOME ISOLATED WIND DAMAGE REPORTS. WITH THE FREEZING
LEVEL NEAR 15,500 FT AND THE -20 NEAR 26,000 FT... HAIL WOULD BE
LESS OF A THREAT BUT THERE IS A FAIR AMOUNT OF CAPE IN THE -10 TO
-20C LAYER SO I CAN NOT TOTALLY RULE IT OUT.
WITH THE FASTER MOVEMENT OF THE SYSTEM TEMPERATURES MAY NOT GET TO
90 DEGREES AFTER ALL SINCE THE CLOUDS WILL BE MOVING IN SHORTLY
(BASED ON VISIBLE AND IR LOOPS). STILL WE SHOULD SEE MID TO UPPER
80S INLAND WITH NO PROBLEM.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN ISSUE IN THE SHORT TERM IS FOG THIS MORNING...THEN STORM
POTENTIAL AND SEVERE THREAT FOR LATE TODAY AND TONIGHT.
A FAIR AMOUNT OF FOG AND LOW CLOUDS HAVE DEVELOPED OVER THE NRN
SECTION OF THE CWFA EARLY THIS MORNING. SOME OF THIS IS STARTING TO
DEVELOP FURTHER SOUTH AS A WEAK SFC TROUGH CRAWLING SOUTH ACROSS THE
AREA IS LIKELY BEING OVERRUN A BIT JUST OFF THE SFC AND WITH THE
HUMID AIR MASS IN PLACE. WE DO EXPECT THAT THIS WILL DISSIPATE
DURING THE MID MORNING HOURS AS THE STRONG SUN ANGLE WORKS ON THE
SHALLOW LAYER OF MOISTURE.
WE EXPECT TO SEE A GOOD DEAL OF SUNSHINE AFTER THE LOW CLOUDS AND
FOG DISSIPATE. THE AREA WILL BE UNDER THE INFLUENCE OF SHORT WAVE
RIDGING ALOFT BETWEEN THE DEPARTING WAVE FROM YESTERDAY AND THE NEXT
WAVE EXPECTED TONIGHT. FCST SOUNDINGS SHOW A WARM LAYER BETWEEN
850-700MB THAT SHOULD CAP MOST IF NOT ALL CONVECTIVE DEVELOPMENT
THROUGH ALMOST 00Z. WE CAN NOT RULE OUT AN ISOLATED SHOWER/STORM
DEVELOPING ALONG A BOUNDARY LIKE A LAKE BREEZE. THAT SAID...THE LOW
LEVEL FLOW LOOKS FAIRLY DIVERGENT DURING THE DAY TODAY WHICH SHOULD
LIMIT ANY DEVELOPMENT ALSO.
THE AREA STILL LOOKS LIKE IT IS ON TRACK FOR A BATCH OF SHOWERS AND
STORMS TO MOVE THROUGH TONIGHT. THE BEST CHANCE WILL OCCUR ALONG AND
SOUTH OF INTERSTATE 96. OUR FOCUS IS ON THE SHORT WAVE PRODUCING
CONVECTION ACROSS THE DAKOTAS...AND THE EVENTUAL LLJ THAT IS
EXPECTED TO DEVELOP THIS EVENING/OVERNIGHT.
WE DO EXPECT THE SHORT WAVE TO MOVE INTO THE AREA TOWARD 06Z. IT
SEEMS THAT THE CONVECTION ACROSS THE DAKOTAS SHOULD SLOWLY MOVE
THROUGH THE DAY. WE COULD SEE IT INTENSIFY A BIT IN WISCONSIN THIS
AFTERNOON AS IT ENCOUNTERS BUILDING INSTABILITY THERE. THIS LINE
WILL LIKELY DIMINISH SOME AS IT HEADS TOWARD OUR CWFA TONIGHT WITH
THE LOSS OF DIURNAL INSTABILITY.
WHAT WE WILL SEE IS THE LLJ INCREASE A BIT AND THE NOSE BE AIMED AT
THE SRN HALF OF THE CWFA BY 06Z. THIS SHOULD HELP MAINTAIN A FAIRLY
DECENT AREA OF SHOWERS AND STORMS THAT WOULD LAST INTO THE DAYBREAK
HOURS ON WED BEFORE MOVING OUT. SEVERE THREAT DOES NOT SEEM VERY
IMPRESSIVE DUE TO THE LATE NIGHT TIME FRAME THE CONVECTION WOULD BE
MOVING IN. FCST SOUNDINGS INDICATE THAT THE CAPE IN THE -10 TO -30C
LAYER IS NOT REAL ABUNDANT. DEEP LAYER CLOUD LAYER SHEAR IS ON THE
LOWER SIDE AROUND 20-25 KNOTS OR SO. MOST OF THE STORMS WOULD BE
ELEVATED WITH SOME POSSIBILITY OF SOME WINDS MAKING IT DOWN WITH
SOME RESIDUAL LOW LEVEL INSTABILITY.
WE FEEL THAT IF THE STORMS MOVE THROUGH AS EXPECTED TONIGHT...MOST
OF THE CWFA WILL BE WORKED OVER ENOUGH FOR WED THAT THE THREAT OF
STORMS AND SEVERE WEATHER IS LOW. IT WILL TAKE A WHILE TO BUILD UP
THE INSTABILITY...AND THE FRONT SHOULD CLEAR THE CWFA BY PEAK
HEATING. THE BEST CHC FOR STORMS WILL BE DOWN SOUTH WHERE LOCATIONS
DO NOT SEE MCS ACTIVITY TONIGHT.
WE WILL SEE SKIES CLEAR THEN WED EVENING AND CONTINUE THROUGH THU AS
DRIER AND COOLER AIR MOVES IN. A SHORT WAVE DOES MOVE THROUGH FROM
THE NW ON THU...HOWEVER THE AIR SHOULD BE DRY ENOUGH AND WE WILL BE
ON THE DOWNSTREAM SIDE OF THE LONG WAVE RIDGE TO OUR WEST TO KEEP US
DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE ARRIVAL OF MID LEVEL RIDGING EARLY IN THE PERIOD SUPPORTS A DRY
PATTERN FOR THE REGION THEN. SUBSIDENCE IS SEEN ON BUFKIT OVERVIEWS
AND MOISTURE PROFILES REMAIN DRY THROUGH SAT. A WARM AIR ADVECTION
PATTERN SETS UP BY SUNDAY AND PWAT VALUES WILL BE ON THE INCREASE.
A WEAKENING SURFACE FRONT SLIPS DOWN FROM THE NORTHWEST SUNDAY NIGHT
INTO MONDAY. WITH SOME ELEVATED/SURFACE INSTABILITY ALONG OR AHEAD
OF THE FRONTAL ZONE...THERE COULD BE A FEW STORMS.
THE BELOW NORMAL TEMPERATURES TO START THE PERIOD TRANSITION TO
ABOVE NORMAL VALUES FOR THE END OF THE PERIOD. TEMPERATURE VALUES
AT 925 MB CLIMB INTO THE LOW TO MID 20 DEG C RANGE SUNDAY. WITH
SOME SUN...WE SHOULD EASILY REACH THE MID 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 739 AM EDT TUE JUL 9 2013
LOW CLOUDS WILL BE SLOW DO DISSIPATE ESPECIALLY CLOSER TO THE
LAKESHORE THIS MORNING. IMPACTS TO PERSIST WITH IFR/LIFR COMMON TO
START. BY 16Z CONDITIONS AT MOST SITES SHOULD BE MVFR.
LINE OF STORMS TRACKING THROUGH NRN IOWA WILL ARRIVE IN WRN MI
AFTER 19Z IF THEY SURVIVE. UNSTABLE CONDITIONS PERSIST MUCH OF THE
NIGHT. SO TAFS WILL FEATURE THE POSSIBILITY OF A STORM THROUGH THE EVENING.
&&
.MARINE...
ISSUED AT 335 AM EDT TUE JUL 9 2013
NO HEADLINES WILL BE ISSUED WITH THIS FCST PACKAGE...HOWEVER WE ARE
LOOKING AT FOG POTENTIAL THROUGH TONIGHT...ROUGH WEATHER TONIGHT
WITH A POSSIBLE ROUND OF STORMS...AND THEN SOME DECENT WINDS
POSSIBLE WED BEHIND THE FRONT.
THE LIGHT GRADIENT OVER THE LAKE THIS MORNING ALONG WITH THE HUMID
AIR MASS OVER THE SOMEWHAT COOL WATER IS LIKELY PRODUCING SOME FOG.
WEBCAMS SHOW SOME PLACES SEEING FOG WHILE OTHERS ARE NOT. WE DO NOT
FEEL CONFIDENT ENOUGH AT THIS TIME TO ISSUE A MARINE FOG ADVISORY...
HOWEVER IT IS SOMETHING WE WILL NEED TO MONITOR.
WINDS AHEAD OF THE WAVE MOVING IN TONIGHT WILL HAVE THE POTENTIAL TO
INCREASE THE WINDS AND WAVES SOME TONIGHT. THE BIGGER THREAT WILL
LIKELY BE THE STORMS THAT ARE ANTICIPATED. THE BEST WIND WILL COME
WITH ANY STORMS. A DECENT NW WIND COULD DEVELOP LATE WED AFTERNOON
BEHIND THE FRONT THAT PUSHES THROUGH. A SMALL CRAFT ADVISORY MAY BE
NEEDED FOR THAT PERIOD.
&&
.HYDROLOGY...
ISSUED AT 335 AM EDT TUE JUL 9 2013
THE MAIN PERIOD OF CONCERN AS FAR AS HYDRO IS CONCERNED IS THE
TONIGHT PERIOD. WE WILL SEE PRECIPITABLE WATER INCREASE TO AROUND
2.00 INCHES THIS EVENING AHEAD OF THE WAVE THAT WILL MOVE THROUGH
THE AREA. THIS WILL PROVIDE THE POTENTIAL OF HEAVY DOWNPOURS ACROSS
THE AREA. WE DO NOT ANTICIPATE SIGNIFICANT WIDESPREAD ISSUES AS THIS
WAVE THAT MOVES THROUGH SHOULD BE RATHER PROGRESSIVE. AMOUNTS WILL
LIKELY BE A QUARTER TO THREE QUARTERS OF AN INCH OF RAINFALL FOR
BASIN AVERAGES...WITH SOME LOCAL AREAS SEEING 1-2 INCHES OF RAIN.
URBAN AND SMALL STREAM ISSUES WILL BE THE MAIN THREAT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DULUTH MN
314 PM CDT TUE JUL 9 2013
.SHORT TERM...THROUGH EARLY WEDNESDAY EVENING.
COVERAGE OF SHOWERS AND STORMS HAVE DIMINISHED OVER MUCH OF THE
NORTHLAND THIS AFTERNOON...WITH HIGHEST CONCENTRATION OVER OUR FAR
EASTERN ZONES ALONG AND AHEAD OF THE LOW LEVEL BOUNDARY.
ADDITIONAL ISOLATED SHOWERS WERE OCCURRING BEHIND THIS BOUNDARY
WITH OTHERS ASSOCIATED WITH THE UPPER WAVE OVER SOUTHERN
MANITOBA/NORTHERN NORTH DAKOTA. LATEST HRRR HAS A DECENT HANDLE ON
CURRENT CONVECTION...AND SHOWS COVERAGE REMAINING LIMITED TONIGHT.
WE DO HAVE POPS THIS EVENING OVER MUCH OF THE NORTHLAND...BUT
DECREASE THEM FROM WEST TO EAST TONIGHT. THE THREAT FOR SEVERE STORMS IS
LOW AS BEST CONVERGENCE SHOULD BE EXITING OUR CWA THIS
EVENING...AND STABILITY AND SHEAR ARE NOT REAL SUPPORTIVE GIVEN
THE AMOUNT OF LIFT.
SOME FOG MAY LINGER THIS EVENING AROUND LAKE
SUPERIOR...PARTICULARLY UP THE NORTH SHORE...BUT THEN THAT SHOULD
DIMINISH OVERNIGHT AS WINDS TURN NORTHWEST BEHIND THE FRONT.
WEDNESDAY SHOULD FEATURE PARTLY TO MOSTLY SUNNY SKIES WITH HIGH
PRESSURE BUILDING IN. TEMPERATURES WILL BE IN THE SEVENTIES. WE DO
EXPECT GOOD MIXING WITH STEEP LAPSE RATES. THIS WILL LEAD TO SOME
GUSTY WINDS BY AFTERNOON. SOME STEEPER LAPSE RATES OVER THE
ARROWHEAD AND IT`S PROXIMITY TO THE EXITING UPPER TROUGH SHOULD BE
ENOUGH TO CAUSE SOME THICKER CLOUDS UP THERE BY WEDNESDAY
AFTERNOON. WE LEFT THAT AREA DRY...BUT LATER SHIFTS WILL HAVE TO
MONITOR FOR THE POSSIBLE ADDITION OF A FEW SHOWERS OR
THUNDERSTORMS IN THE AFTERNOON.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
A LARGE SFC HIGH AND ASSOCIATED UPPER RIDGE WILL BE BUILDING IN
ACROSS THE UPPER MIDWEST WED NIGHT...ALONG WITH DRYING CONDITIONS
AND MOSTLY CLEAR SKIES. RELATIVELY COOL TEMPS COULD DEVELOP EARLY
THUR MORNING UNDER CALM WINDS AND STRONG RADIATIONAL COOLING. SHOULD
SEE MOSTLY SUNNY SKIES ON THURSDAY WITH HIGHS IN THE 70S AROUND THE
LAKE AND 80S INLAND. THUR NIGHT SHOULD REMAIN MOSTLY CLEAR WITH HIGH
PRESSURE IN PLACE. HOWEVER...AS THE SFC HIGH SHIFTS EWD...A RETURN
SLY FLOW WILL DEVELOP AND BEGIN TO USHER IN MORE CLOUD COVER AND A
RICHER MORE UNSTABLE AIR MASS AHEAD OF THE NEXT SFC TROUGH/COLD
FRONT EXPECTED TO MOVE INTO THE REGION THIS WEEKEND. FRIDAY WILL BE
A TRANSITION DAY WITH CLOUDS INCREASING FROM THE W...BUT MINIMAL
PRECIP CHANCES UNTIL LATER FRI NIGHT. MODEL GUIDANCE IS INDICATING
THAT THE SFC FRONT WILL STALL OUT ACROSS NRN MN/WRN LAKE SUPERIOR
ALONG THE NRN/NWRN FRINGES OF AN ELONGATED RIDGE SITUATED OVER THE
MID MS VALLEY/SRN GREAT LAKES REGION. THIS PATTERN WOULD ALLOW FOR A
PROLONGED PERIOD OF SHOWERS AND STORMS THROUGH THE WEEKEND AND INTO
EARLY NEXT WEEK...WITH POTENTIALLY PERIODS OF HEAVY RAIN. WILL NEED
TO MONITOR THIS PATTERN AND ANY CHANGES DURING THE NEXT COUPLE DAYS.
COULD BE DEALING WITH HYDRO ISSUES SAT THROUGH MON.
OTHERWISE...TEMPERATURES REMAIN VERY SEASONAL...WITH HIGHS IN THE
70S AND LOWER 80S AND LOWS IN THE 50S AND LOWER 60S.
&&
.AVIATION...18Z TAF ISSUANCE.
WIDESPREAD RAIN SHOWERS WITH AFTERNOON EMBEDDED THUNDERSTORMS ARE
EXPECTED THE REST OF TODAY BEFORE THE MAIN SFC FRONT PUSHES
THROUGH EARLY THIS EVENING AND ALLOWS CONDITIONS TO DRY OUT LATE
TONIGHT AND TOMORROW. A FEW OF THE STORMS THIS AFTERNOON COULD
PRODUCE HAIL AND VERY STRONG WIND GUSTS. DENSE FOG SHOULD REMAIN
CONFINED TO LAKE SUPERIOR AND THE IMMEDIATE LATE SHORE THROUGH
21Z...AND NOT HAVE TOO MUCH OF AN IMPACT ON THE DLH TERMINAL.
WINDS SHIFT TO THE NW QUICKLY BEHIND THE FRONT TONIGHT AND BECOME
GUSTY WED MORNING.
&&
.POINT TEMPS/POPS...
DLH 54 77 56 79 / 40 0 0 0
INL 53 76 55 82 / 30 10 0 0
BRD 56 78 55 82 / 20 0 0 0
HYR 56 78 52 81 / 50 0 0 0
ASX 54 76 51 79 / 50 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM....TENTINGER
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
1254 PM CDT TUE JUL 9 2013
.UPDATE...
SHOWERS AND SOME THUNDERSTORMS REMAINED OVER MUCH OF THE
CWA...WITH COVERAGE LIMITED OVER OUR SOUTHERN ZONES FROM HAYWARD
WEST TO THE BRAINERD LAKES REGION. HOWEVER...WE STILL SEE SOME
DEVELOPMENT SO WILL KEEP POPS GOING DOWN THERE THROUGHOUT THE
AFTERNOON. LATEST KDLH IMAGE SHOWS A CELL JUST SOUTHEAST OF FORT
RIPLEY...AND WE SHOULD SEE ADDITIONAL DEVELOPMENT AS WELL IN THIS
MOIST AIRMASS. INSTABILITY HAS WANED A BIT WITH MUCAPE VALUES
500-1000J/KG...BUT THAT SHOULD INCREASE...ESPECIALLY WITH SOME
BREAKS DEVELOPING IN THE CLOUD COVER PER LATEST VISIBLE IMAGERY.
THE FRONTAL BOUNDARY WAS OVER OUT WESTERN ZONES AS OF 18Z AND THE
UPPER WAVE WAS OVER SOUTHERN MB/NORTHERN ND. WE COULD STILL SEE A
SEVERE STORM THIS AFTERNOON AHEAD OF THE COLD FRONT...BUT COVERAGE
SHOULD BE LIMITED DUE TO ALL THE CLOUD COVER. AS MENTIONED
THOUGH...SOME BREAKS IN THE CLOUDS WERE DEVELOPING...AND MAY ALLOW
FURTHER DESTABILIZATION.
THE FOG HAS THINNED QUITE A BIT AROUND LAKE SUPERIOR...BUT
WEBCAMS DO SHOW SOME HANGING AROUND LAKE SUPERIOR...ESPECIALLY UP
THE NORTH SHORE.
&&
.PREV DISCUSSION... /ISSUED 1210 PM CDT TUE JUL 9 2013/
AVIATION...18Z TAF ISSUANCE...
WIDESPREAD RAIN SHOWERS WITH AFTERNOON EMBEDDED THUNDERSTORMS ARE
EXPECTED THE REST OF TODAY BEFORE THE MAIN SFC FRONT PUSHES
THROUGH EARLY THIS EVENING AND ALLOWS CONDITIONS TO DRY OUT LATE
TONIGHT AND TOMORROW. A FEW OF THE STORMS THIS AFTERNOON COULD
PRODUCE HAIL AND VERY STRONG WIND GUSTS. DENSE FOG SHOULD REMAIN
CONFINED TO LAKE SUPERIOR AND THE IMMEDIATE LATE SHORE THROUGH
21Z...AND NOT HAVE TOO MUCH OF AN IMPACT ON THE DLH TERMINAL.
WINDS SHIFT TO THE NW QUICKLY BEHIND THE FRONT TONIGHT AND BECOME
GUSTY WED MORNING.
PREV DISCUSSION... /ISSUED 923 AM CDT TUE JUL 9 2013/
UPDATE...
FOCUS IN THE SHORT TERM IS COVERAGE OF RAIN/STORMS AND THEIR
INTENSITY.
A LINE OF STRONG-SEVERE STORMS WERE MOVING INTO WEST
CENTRAL/NORTHWEST WISCONSIN AS OF MID MORNING...WITH A KMPX RADAR
SHOWING A A NICE AREA OF OUTBOUND VELOCITY FROM 50-60 KT AT TIMES.
THIS LINE WAS MOVING EAST/NORTHEAST 40-45 MPH. AN AREA OF RAIN
WITH SOME EMBEDDED STORMS EXTENDED NORTH INTO NORTHWEST
MINNESOTA/MANITOBA/NORTHWEST ONTARIO AS WELL. RADAR TRENDS SHOW A
DIMINISHING TREND IN WHAT WAS A MORE ORGANIZED AREA OF
SHOWERS/STORMS WITH FEW RETURNS HEADED FOR THE IRON
RANGE/ARROWHEAD. THE FRONT AND MAIN SHORTWAVE ARE STILL
WEST/NORTHWEST OF THE CWA...SO THERE IS AMPLE LIFT THAT NEEDS TO
MOVE THROUGH THE NORTHLAND YET TODAY AND THAT WILL LEAD TO
ADDITIONAL CHANCES FOR STORMS THROUGH THE DAY. WE WILL CONTINUE TO
MAKE SHORT TERM ADJUSTMENTS TO GRIDS ACCOUNTING FOR RADAR TRENDS.
THE NAM SUGGESTS COVERAGE SHOULD INCREASE THROUGH THE DAY. THE 12Z
KMPX/KINL SOUNDINGS EACH HAD PWAT VALUES OF 1.75 AND 1.41 INCHES.
SPC MESOANALYSIS DEPICTED AROUND 30KT DEEP LAYER SHEAR WITH
500-1500J/KG OF MUCAPE. 11Z HRRR WAS DOING AN OK JOB DEPICTING 14Z
RAIN/STORMS...AND ALSO SHOWS THE RAIN SPLITTING WITH ADDITIONAL
SCATTERED SHOWERS/STORMS DEVELOPING THIS AFTERNOON INTO THE
EVENING.
SHORT TERM SEVERE THREAT WILL BE OVER OUR NORTHWEST WISCONSIN
ZONES OVER THE NEXT 1 TO 3 HOURS...THEN SHIFTS AHEAD OF THE FRONT
THIS AFTERNOON AS IT MOVES THROUGH THE CWA.
PREV DISCUSSION... /ISSUED 621 AM CDT TUE JUL 9 2013/
AVIATION.../12Z TAF ISSUANCE/
EARLY MORNING LIFR/IFR CONDITIONS DUE TO FOG ACROSS PARTS OF NE
MINNESOTA AND NW WISCONSIN...INCLUDING KDLH AND KHIB...SHOULD LIFT
AND BREAK UP WITHIN THE NEXT FEW HOURS. SHOWERS AND THUNDERSTORMS
ARE LIKELY ACROSS THE NORTHLAND TODAY AND EARLY THIS EVENING. THE
SHOWERS AND STORMS COULD BRING BRIEF MVFR CONDITIONS DUE TO LOW
CIGS AND VSBY RESTRICTIONS FROM RAIN. THE REGION WILL BEGIN TO
CLEAR THIS EVENING AS HIGH PRESSURE BEGINS TO MOVE INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. EXPECT VFR CONDITIONS LATE THIS
EVENING AND WEDNESDAY MORNING. THE VERY LIGHT WINDS WILL INCREASE
LATE THIS AFTERNOON AND THIS EVENING AND BECOME NW IN THE WAKE OF
A PASSING COLD FRONT.
PREV DISCUSSION... /ISSUED 453 AM CDT TUE JUL 9 2013/
SHORT TERM...TODAY AND TONIGHT.
CURRENT REGIONAL RADAR IMAGERY SHOWS A LARGE AREA OF SHRA/TSTORMS
ASSOCIATED WITH A MID-LEVEL TROUGH EXTENDING FROM SRN MANITOBA...ALONG
THE WESTERN MN BORDER...INTO IOWA. AT THIS TIME...THE STRONGEST
STORMS...LOCATED WITH A STRENGTHEN MCS...IS FOUND EXITING EASTERN
SD AND MOVING INTO THE SW PORTION OF MN.
LATEST HIGH RES MODEL RUNS OF THE WRF/HRRR HAVE A RELATIVELY DECENT
HANDLE ON THE CURRENT CONVECTION AND BOTH SHOW THE STORMS
DECREASING SOMEWHAT...BUT OVERALL HOLDING TOGETHER AS THE LINE
MARCHES EAST ACROSS MINNESOTA THIS MORNING. HAVE ADJUSTED POPS
THIS MORNING TO LIKELY USING THE CURRENT DISTANCE/SPEED OF THE
LINE OF STORMS FOR TIMING. AT THE CURRENT SPEED...THE LEADING EDGE
OF THESE STORMS WILL ARRIVE IN THE KINL TO KBRD AREA AROUND 700 TO
800 AM...REACHING A LINE FROM KHIB TO KDLH AND EXTENDING SOUTH
ALONG THE INTERSTATE 35 CORRIDOR AROUND 10-11 AM. THE LIMITING
FACTOR WILL BE IF THE MCS TRACKING ACROSS CENTRAL MINNESOTA CUTS
OFF THE MOISTURE TO STORMS FURTHER NORTH.
SHIFTING FOCUS TO ADDITIONAL THUNDER DEVELOPMENT THIS AFTERNOON
ALONG A SFC COLD FRONT. THE SEVERITY AND COVERAGE OF THE
AFTERNOON CONVECTION WILL BE HIGHLY DEPENDENT ON THE HOW WORKED
OVER THE REGION BECOMES WITH THE STORMS THIS MORNING. HAVE
BROADBRUSH SCT THUNDER OVER MN ZONES...WITH LIKELY ACROSS THE TIP
OF THE ARROWHEAD AND NRN WIS AREAS THROUGH THIS EVENING.
LONG TERM [WEDNESDAY - MONDAY]
THE BEGINNING OF THE PERIOD LOOKS RELATIVELY QUIET. HIGH PRESSURE
AND NW FLOW SHOULD PROVIDE MILD WEATHER AND SUNNY SKIES ACROSS THE
NORTHLAND. WE EXPECT A WARMING TREND LATE THIS WEEK...LIKELY
CULMINATING ON FRIDAY...AS A MID/UPPER LEVEL RIDGE BUILDS INTO THE
UPPER MIDWEST AND SOUTHERLY WINDS INCREASE ACROSS THE NORTHLAND.
MUCH OF THE NORTHLAND...SAVE THE IMMEDIATE NORTH SHORE...SHOULD HAVE
TEMPERATURES AT LEAST IN THE LOW TO MID 80S ON FRIDAY. I INCREASED
THE FRIDAY HIGH TEMPERATURES SINCE I THINK THE MOS GUIDANCE IS TOO
WEIGHTED TOWARDS CLIMATOLOGY...AND WE MIGHT NEED TO INCREASE EVEN
THE HIGHS EVEN MORE.
A COLD FRONT WILL APPROACH THE NORTHLAND LATE THIS WEEK AND THEN
MIGHT STALL OR SLOWLY PROGRESS THROUGH THE REGION THROUGH EARLY NEXT
WEEK. THIS WILL BRING A PERIOD OF SEVERAL DAYS WHERE THE NORTHLAND
WILL HAVE CHANCES OF SHOWERS AND THUNDERSTORMS. FOR NOW...LATE
FRIDAY NIGHT AND SATURDAY MORNING APPEARS TO BE THE PERIOD IN WHICH
THE NORTHLAND WILL HAVE THE GREATEST CHANCES OF SHOWERS AND STORMS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE APPROACHING/PASSING
COLD FRONT WILL BRING WIDESPREAD RAINFALL OF AT LEAST A TENTH TO
QUARTER INCH OF RAIN TO THE NORTHLAND.
&&
.POINT TEMPS/POPS...
DLH 54 77 54 79 / 40 0 0 0
INL 53 76 50 82 / 10 10 0 0
BRD 56 78 56 83 / 10 0 0 0
HYR 56 78 51 84 / 50 0 0 0
ASX 54 76 52 80 / 50 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1210 PM CDT TUE JUL 9 2013
.AVIATION...18Z TAF ISSUANCE...
WIDESPREAD RAIN SHOWERS WITH AFTERNOON EMBEDDED THUNDERSTORMS ARE
EXPECTED THE REST OF TODAY BEFORE THE MAIN SFC FRONT PUSHES
THROUGH EARLY THIS EVENING AND ALLOWS CONDITIONS TO DRY OUT LATE
TONIGHT AND TOMORROW. A FEW OF THE STORMS THIS AFTERNOON COULD
PRODUCE HAIL AND VERY STRONG WIND GUSTS. DENSE FOG SHOULD REMAIN
CONFINED TO LAKE SUPERIOR AND THE IMMEDIATE LATE SHORE THROUGH
21Z...AND NOT HAVE TOO MUCH OF AN IMPACT ON THE DLH TERMINAL.
WINDS SHIFT TO THE NW QUICKLY BEHIND THE FRONT TONIGHT AND BECOME
GUSTY WED MORNING.
&&
.PREV DISCUSSION... /ISSUED 923 AM CDT TUE JUL 9 2013/
UPDATE...
FOCUS IN THE SHORT TERM IS COVERAGE OF RAIN/STORMS AND THEIR
INTENSITY.
A LINE OF STRONG-SEVERE STORMS WERE MOVING INTO WEST
CENTRAL/NORTHWEST WISCONSIN AS OF MID MORNING...WITH A KMPX RADAR
SHOWING A A NICE AREA OF OUTBOUND VELOCITY FROM 50-60 KT AT TIMES.
THIS LINE WAS MOVING EAST/NORTHEAST 40-45 MPH. AN AREA OF RAIN
WITH SOME EMBEDDED STORMS EXTENDED NORTH INTO NORTHWEST
MINNESOTA/MANITOBA/NORTHWEST ONTARIO AS WELL. RADAR TRENDS SHOW A
DIMINISHING TREND IN WHAT WAS A MORE ORGANIZED AREA OF
SHOWERS/STORMS WITH FEW RETURNS HEADED FOR THE IRON
RANGE/ARROWHEAD. THE FRONT AND MAIN SHORTWAVE ARE STILL
WEST/NORTHWEST OF THE CWA...SO THERE IS AMPLE LIFT THAT NEEDS TO
MOVE THROUGH THE NORTHLAND YET TODAY AND THAT WILL LEAD TO
ADDITIONAL CHANCES FOR STORMS THROUGH THE DAY. WE WILL CONTINUE TO
MAKE SHORT TERM ADJUSTMENTS TO GRIDS ACCOUNTING FOR RADAR TRENDS.
THE NAM SUGGESTS COVERAGE SHOULD INCREASE THROUGH THE DAY. THE 12Z
KMPX/KINL SOUNDINGS EACH HAD PWAT VALUES OF 1.75 AND 1.41 INCHES.
SPC MESOANALYSIS DEPICTED AROUND 30KT DEEP LAYER SHEAR WITH
500-1500J/KG OF MUCAPE. 11Z HRRR WAS DOING AN OK JOB DEPICTING 14Z
RAIN/STORMS...AND ALSO SHOWS THE RAIN SPLITTING WITH ADDITIONAL
SCATTERED SHOWERS/STORMS DEVELOPING THIS AFTERNOON INTO THE
EVENING.
SHORT TERM SEVERE THREAT WILL BE OVER OUR NORTHWEST WISCONSIN
ZONES OVER THE NEXT 1 TO 3 HOURS...THEN SHIFTS AHEAD OF THE FRONT
THIS AFTERNOON AS IT MOVES THROUGH THE CWA.
PREV DISCUSSION... /ISSUED 621 AM CDT TUE JUL 9 2013/
AVIATION.../12Z TAF ISSUANCE/
EARLY MORNING LIFR/IFR CONDITIONS DUE TO FOG ACROSS PARTS OF NE
MINNESOTA AND NW WISCONSIN...INCLUDING KDLH AND KHIB...SHOULD LIFT
AND BREAK UP WITHIN THE NEXT FEW HOURS. SHOWERS AND THUNDERSTORMS
ARE LIKELY ACROSS THE NORTHLAND TODAY AND EARLY THIS EVENING. THE
SHOWERS AND STORMS COULD BRING BRIEF MVFR CONDITIONS DUE TO LOW
CIGS AND VSBY RESTRICTIONS FROM RAIN. THE REGION WILL BEGIN TO
CLEAR THIS EVENING AS HIGH PRESSURE BEGINS TO MOVE INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. EXPECT VFR CONDITIONS LATE THIS
EVENING AND WEDNESDAY MORNING. THE VERY LIGHT WINDS WILL INCREASE
LATE THIS AFTERNOON AND THIS EVENING AND BECOME NW IN THE WAKE OF
A PASSING COLD FRONT.
PREV DISCUSSION... /ISSUED 453 AM CDT TUE JUL 9 2013/
SHORT TERM...TODAY AND TONIGHT.
CURRENT REGIONAL RADAR IMAGERY SHOWS A LARGE AREA OF SHRA/TSTORMS
ASSOCIATED WITH A MID-LEVEL TROUGH EXTENDING FROM SRN MANITOBA...ALONG
THE WESTERN MN BORDER...INTO IOWA. AT THIS TIME...THE STRONGEST
STORMS...LOCATED WITH A STRENGTHEN MCS...IS FOUND EXITING EASTERN
SD AND MOVING INTO THE SW PORTION OF MN.
LATEST HIGH RES MODEL RUNS OF THE WRF/HRRR HAVE A RELATIVELY DECENT
HANDLE ON THE CURRENT CONVECTION AND BOTH SHOW THE STORMS
DECREASING SOMEWHAT...BUT OVERALL HOLDING TOGETHER AS THE LINE
MARCHES EAST ACROSS MINNESOTA THIS MORNING. HAVE ADJUSTED POPS
THIS MORNING TO LIKELY USING THE CURRENT DISTANCE/SPEED OF THE
LINE OF STORMS FOR TIMING. AT THE CURRENT SPEED...THE LEADING EDGE
OF THESE STORMS WILL ARRIVE IN THE KINL TO KBRD AREA AROUND 700 TO
800 AM...REACHING A LINE FROM KHIB TO KDLH AND EXTENDING SOUTH
ALONG THE INTERSTATE 35 CORRIDOR AROUND 10-11 AM. THE LIMITING
FACTOR WILL BE IF THE MCS TRACKING ACROSS CENTRAL MINNESOTA CUTS
OFF THE MOISTURE TO STORMS FURTHER NORTH.
SHIFTING FOCUS TO ADDITIONAL THUNDER DEVELOPMENT THIS AFTERNOON
ALONG A SFC COLD FRONT. THE SEVERITY AND COVERAGE OF THE
AFTERNOON CONVECTION WILL BE HIGHLY DEPENDENT ON THE HOW WORKED
OVER THE REGION BECOMES WITH THE STORMS THIS MORNING. HAVE
BROADBRUSH SCT THUNDER OVER MN ZONES...WITH LIKELY ACROSS THE TIP
OF THE ARROWHEAD AND NRN WIS AREAS THROUGH THIS EVENING.
LONG TERM [WEDNESDAY - MONDAY]
THE BEGINNING OF THE PERIOD LOOKS RELATIVELY QUIET. HIGH PRESSURE
AND NW FLOW SHOULD PROVIDE MILD WEATHER AND SUNNY SKIES ACROSS THE
NORTHLAND. WE EXPECT A WARMING TREND LATE THIS WEEK...LIKELY
CULMINATING ON FRIDAY...AS A MID/UPPER LEVEL RIDGE BUILDS INTO THE
UPPER MIDWEST AND SOUTHERLY WINDS INCREASE ACROSS THE NORTHLAND.
MUCH OF THE NORTHLAND...SAVE THE IMMEDIATE NORTH SHORE...SHOULD HAVE
TEMPERATURES AT LEAST IN THE LOW TO MID 80S ON FRIDAY. I INCREASED
THE FRIDAY HIGH TEMPERATURES SINCE I THINK THE MOS GUIDANCE IS TOO
WEIGHTED TOWARDS CLIMATOLOGY...AND WE MIGHT NEED TO INCREASE EVEN
THE HIGHS EVEN MORE.
A COLD FRONT WILL APPROACH THE NORTHLAND LATE THIS WEEK AND THEN
MIGHT STALL OR SLOWLY PROGRESS THROUGH THE REGION THROUGH EARLY NEXT
WEEK. THIS WILL BRING A PERIOD OF SEVERAL DAYS WHERE THE NORTHLAND
WILL HAVE CHANCES OF SHOWERS AND THUNDERSTORMS. FOR NOW...LATE
FRIDAY NIGHT AND SATURDAY MORNING APPEARS TO BE THE PERIOD IN WHICH
THE NORTHLAND WILL HAVE THE GREATEST CHANCES OF SHOWERS AND STORMS.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE APPROACHING/PASSING
COLD FRONT WILL BRING WIDESPREAD RAINFALL OF AT LEAST A TENTH TO
QUARTER INCH OF RAIN TO THE NORTHLAND.
&&
.POINT TEMPS/POPS...
DLH 55 76 54 79 / 40 0 0 0
INL 54 77 50 82 / 10 10 0 0
BRD 56 79 56 83 / 10 0 0 0
HYR 57 80 51 84 / 50 0 0 0
ASX 55 76 52 80 / 50 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...MELDE
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
415 PM CDT Tue Jul 9 2013
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 414 PM CDT TUE JUL 9 2013
Tonight - The primary concern for the next 15 hours centers on rain
chances and coverage. A very hot and humid airmass covers the CWA
with the hot air extending to at least h7. While the latest progged
thermodynamics indicate a very unstable airmass over the region
with little if any CIN the lack of cumulus development suggests two
things...the convective temperature has not been reached and the
progged h7 temperatures are warmer than forecast. The models had
forecast cooling h7 temperatures by this time over parts of northern
MO in response to convection already in progress. While convection
has not reformed the latest visible satellite imagery does show a
growing cumulus filed from central into southwest IA near an weak
surface trough which extends into central KS. This boundary is the
most likely area to focus on for scattered convective development
late this afternoon and early evening. Will continue with 40-50%
PoPs north of I-70 overnight. Given steep lapse rates through h7,
MLCAPES of 3000-4000 J/kg, 30-40kt 0-6km bulk shear and high cloud
bases large hail and damaging downburst winds will be possible
through this evening. Should convection become organized
sufficiently a decent cold pool could allow for a small MCS to form
which would prolong the severe wind threat.
Otherwise, a weak cold front over northern IA will sink southward
overnight but the cooling effect will lag the frontal passage so
warm and humid conditions will persist.
Wednesday and Wednesday night - High pressure will gradually push
the cold front far enough south on Wednesday to allow some relief
from Tuesday`s heat...with northern MO receiving the most benefit as
drier air will also accompany the northeasterly winds.
Upper troughing developing from the Great Lakes into the OH Valley
and the upper high building northward over the Rockies will create a
northwesterly flow pattern over the Central Plains. This causes me
some concern for afternoon/evening convection over parts of the
western CWA as the GFS and NAM both send a mid level vorticity max
out of eastern WY/western NE towards western MO. With this in mind
have inserted chance PoPs into the far southwestern counties for the
late afternoon and early evening hours.
While temperatures will be cooler on Wednesday we won`t see the full
effects of the cooler/drier air until Wednesday night and Thursday.
.LONG TERM...(Thursday through Tuesday)
Issued at 414 PM CDT TUE JUL 9 2013
Thursday should be the coolest day of the extended period before an
expansive dome of high pressure builds over the central CONUS. As the
ridge develops and becomes parked over the region, temperatures will
steadily warm into the lower 90s across eastern KS and western MO
with upper 80s across the far northeast portion of the CWA. With the
ridge in place precip chances should be nil through Tuesday as any
weak disturbance moving around the periphery of the ridge remains
well to our north. The pattern appears to continue well through next
week as the GFS and EC depict little movement of the upper level
ridge.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1250 PM CDT TUE JUL 9 2013
Timing of organized convection is the primary challenge. A weak
surface trough across northern KS into northwest MO appears to be one
boundary may act to focus scattered convection late this afternoon and
evening. Satellite imagery shows accas field stretching from central
KS through west central MO with some convection noted over central
KS. Short range models RAP and HRRR plus the 12z NAM/GFS seem to be
picking up on this area of convection and develop/move scattered convection
into the terminals late this afternoon or early evening. Believe
there is enough support an earlier start time for VCTS with best
threat a few hours either side of sunset. Due to the hot mid level
temperatures VFR ceilings will prevail which also increases the
threat for strong/gusty winds in any of the stronger storms. Will
address this in an amendment once storms organize.
Will keep VCTS until frontal passage which occurs during the pre-dawn
hours of Wednesday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 7 PM CDT this evening FOR KSZ025-057-060-
102>105.
MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ001>005-011>014-
020>023-028>031-037>039-043>045-053-054.
&&
$$
SHORT TERM...MJ
LONG TERM...Pietrycha
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1252 PM CDT Tue Jul 9 2013
.SHORT TERM...(Today and Tonight)
Issued at 358 AM CDT TUE JUL 9 2013
Early this morning a shortwave trough, moving east along the
U.S/Canadian border, has induced yet another modest nocturnal jet
across the Plains States. This has helped fuel the development of
thunderstorms across eastern Nebraska and western Iowa early this
morning. Active storms are on the verge of entering the far
northwest corner of Missouri early this morning, and are expected to
make some progress east across northern Missouri before the jet
fueling this activity veers off and mixes out after sunrise. Storms
are not expected to develop much farther south than Highway 36 owing
to the CAP advecting in on the nocturnal jet, 700mb temperatures >
12C. Radar trends back this up, but will have to keep a careful eye
on this this morning.
Once the vestiges of the early morning storms dissipate, the heating
for the day will kick into high gear. The hot air that advected in
with the CAP will begin to mix down later today allowing
temperatures to range a category or more higher than Monday. With
850mb temperatures expected to top out in the 25C to 28C range,
expect surface temperatures to bound into the mid to upper 90s along
the Kansas-Missouri state border. While some dry air will likely mix
down this afternoon, taking a slight edge off the humidity, it is
not expected to mitigate heat indices enough to prevent index values
from ranging around 105 degrees by this afternoon. Will be leaving
the going heat advisory as is.
By tonight a frontal boundary across Nebraska and Iowa will begin
its southward progress into Kansas and Missouri as the parent
shortwave trough along the Canadian border moves east. Expectations
are that convection will initiate across Nebraska and Iowa this
afternoon, traversing southeast along with the front. There are some
concerns that a weak outflow boundary from the early morning
activity may wallow around northern Missouri today --maybe as far
south as the Missouri River-- which might provide some focus for
storms to initiate on during the mid to late afternoon hours. Do not
think this is overly likely, but cannot rule it out, so have kept
slight chance POPs going for the afternoon hours. Baring early
initiation across Missouri, expectations are that the activity in
Nebraska and Iowa will track southeast into eastern Kansas and
Missouri this evening. Sufficient shear and instability look to be in
place tonight to warrant a threat from some severe weather, with
damaging wind gusts looking to be the primary threat.
Wednesday...the front that moved into Tuesday night will finish its
progress across our section of the state. Other than any lingering
activity in the morning hours, expect storms to be focused in area
to the south and east of our region by the afternoon hours.
Additionally, the northerly wind behind the front will bring
slightly cooler and drier conditions, think mid-80s along the Iowa
border to low 90s in east central Kansas.
.LONG TERM...(Wednesday through Monday)
Issued at 358 AM CDT TUE JUL 9 2013
Behind Wednesday`s front, high pressure will settle in from the
north for Wednesday night and Thursday, keeping temperatures
relatively lower with lows Weds night in the lower 60s and highs on
Thursday in the mid 80s. This relief from the heat will be
short-lived as upper ridging will quickly build back into the
central U.S. through the end of the week into early next week. Highs
through this period will return into the 90s for western MO and
eastern KS and upper 80s further northeast. Judging by the depth of
the upper ridge, these numbers may need to be adjusted upward with
later forecasts.
Rain chances through the extended period appear low thanks to the
large upper ridge in place. Models are hinting at weak warm air
advection precipitation across eastern KS Wednesday night or
Thursday, but moisture/thermal profiles to not appear supportive of
this. Only other chance appears to be on Monday as the ridge
flattens a bit, but better rain chances will remain well to the
north of the area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1250 PM CDT TUE JUL 9 2013
Timing of organized convection is the primary challenge. A weak
surface trough across northern KS into northwest MO appears to be one
boundary may act to focus scattered convection late this afternoon and
evening. Satellite imagery shows accas field stretching from central
KS through west central MO with some convection noted over central
KS. Short range models RAP and HRRR plus the 12z NAM/GFS seem to be
picking up on this area of convection and develop/move scattered convection
into the terminals late this afternoon or early evening. Believe
there is enough support an earlier start time for VCTS with best
threat a few hours either side of sunset. Due to the hot mid level
temperatures VFR ceilings will prevail which also increases the
threat for strong/gusty winds in any of the stronger storms. Will
address this in an amendment once storms organize.
Will keep VCTS until frontal passage which occurs during the pre-dawn
hours of Wednesday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 7 PM CDT this evening FOR KSZ025-057-060-
102>105.
MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ001>005-011>014-
020>023-028>031-037>039-043>045-053-054.
&&
$$
SHORT TERM...Cutter
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
313 PM CDT TUE JUL 9 2013
.DISCUSSION...
THUNDERSTORM CHANCES TONIGHT AND POSSIBLY WEDNESDAY NIGHT...THEN
HEAT POTENTIAL INTO NEXT WEEK...ARE THE PRIMARY FORECAST CONCERNS.
UPPER RIDGE WAS SPRAWLING ACROSS THE SOUTH HALF OF THE CONUS
TODAY...WITH OUR AREA IN THE TRANSITION ZONE BETWEEN RIDGE TO THE
SOUTH AND FASTER MID LEVEL FLOW TO THE NORTH. A POTENT SHORTWAVE WAS
NOTED IN NORTH DAKOTA SWEEPING EAST THIS AFTERNOON...AND WILL SETTLE
INTO THE GREAT LAKES WEDNESDAY AFTERNOON BEFORE CARVING OUT A TROUGH
OVER NEW ENGLAND BY SATURDAY. SHORTWAVE WILL DRIVE A COLD FRONT
SOUTH OF OUR AREA TONIGHT AND WEDNESDAY...THEN ALLOW UPPER RIDGE TO
BUILD INTO THE PLAINS THIS WEEKEND INTO NEXT WEEK.
EARLY AFTERNOON SURFACE ANALYSIS SHOWED A WIND SHIFT SETTLING SOUTH
TOWARD A COLUMBUS TO TEKAMAH LINE...WITH A SECONDARY BOUNDARY MOVING
OUT OF SOUTH DAKOTA INTO NORTHEAST NEBRASKA. AIRMASS BEHIND THIS
SECOND BOUNDARY WAS CHARACTERIZED BY DEW POINTS IN THE 60S AND
TEMPERATURES CLOSER TO 80. SOUTH OF BOTH BOUNDARIES...TEMPERATURES
WERE CLIMBING INTO THE 90S WITH DEW POINTS IN THE LOW TO MID
70S...PUTTING HEAT INDICES INTO THE 100S AT MANY SPOTS. WILL
MAINTAIN OUR CURRENT HEAT ADVISORY INTO THE EARLY EVENING...AND MAY
TRIM SOME NORTHERN COUNTIES BASED ON OBS.
INSTABILITY WAS ALSO INCREASING MARKEDLY ACROSS SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA WHERE SURFACE-BASED CAPES WERE WELL OVER 3000
J/KG ACCORDING TO LATEST RAP ANALYSIS. HOWEVER FORECAST SOUNDINGS
SHOW A SIGNIFICANT WARM NOSE ABOVE SURFACE LAYER WAS CAPPING ANY
ATTEMPT AT CONVECTION SO FAR. AS FRONTAL BOUNDARY SETTLES INTO
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA THIS EVENING...COMBINED WITH A
LITTLE MORE HEATING AND A WEAK IMPULSE SLIDING ACROSS NORTHERN
KANSAS...EXPECT SCATTERED THUNDERSTORMS TO FIRE IN OUR SOUTHERN
CWA...MOST LIKELY SOUTH OF INTERSTATE 80. IF THOSE DO OCCUR...AMOUNT
OF INSTABILITY AND MODEST BULK SHEAR NEAR 35KT SUGGEST SEVERE STORMS
ARE POSSIBLE WITH DAMAGING WINDS THE MOST LIKELY HAZARD. FREEZING
LEVELS REMAIN QUITE HIGH...IN THE NEIGHBORHOOD OF 14KFT TO
15KFT...SO ONLY STORMS WITH DECENT STRUCTURE/ROTATION SHOULD POSE
HAIL THREAT.
ACTIVITY SHOULD SHIFT SOUTH OF OUR AREA A LITTLE AFTER 06Z TONIGHT
AS FRONT SETTLES SOUTH...LEAVING THE REST OF THE NIGHT DRY. WITH
LOWER DEW POINTS SPILLING INTO THE AREA COMBINED WITH LIGHT
NORTHERLY WINDS...EXPECT LOWS TO DROP INTO THE LOWER 60S NORTH BUT
HOLD IN THE LOWER 70S SOUTH.
A SOMEWHAT COOLER AND DRIER COUPLE OF DAYS STILL LOOKS ON TRACK FOR
WEDNESDAY AND THURSDAY AS DEW POINTS DROP CLOSER TO 60 THAN 70.
HIGHS EACH DAY SHOULD HOLD IN THE MIDDLE 80S OR SO. HOWEVER SOUTH
WINDS WILL RETURN FOR THURSDAY...SO AN INCREASE IN LOW LEVEL
MOISTURE WILL BEGIN THEN. THERE IS ALSO A SMALL CHANCE FOR
THUNDERSTORMS WEDNESDAY NIGHT INTO THURSDAY MORNING...ESPECIALLY
OVER OUR FAR SOUTHWEST CWA AND CENTRAL NEBRASKA...WHERE ZONE OF MID
LEVEL WARM ADVECTION COULD TRIGGER ELEVATED STORMS.
RIDGE BEGINS TO BUILD INTO THE REGION ON FRIDAY AND REMAINS OVER THE
MIDDLE OF THE COUNTRY THROUGH NEXT WEEK. THIS SHOULD NORMALLY KEEP
US DRY AND HOT...BUT ECMWF AND TO SOME EXTENT THE GFS SHOW A
WEAKNESS IN THE RIDGE SUNDAY AND MONDAY THAT MAY ALLOW A SURFACE
FRONT TO DRIFT INTO OUR AREA. CURRENTLY HAVE SMALL POPS DURING THIS
TIME PERIOD...SO WILL NOT CHANGE AT THIS TIME. OTHERWISE EXPECT
TEMPERATURES TO APPROACH OR EXCEED 90 MUCH OF THE PERIOD FRIDAY
THROUGH TUESDAY.
DERGAN
&&
.AVIATION...18Z TAFS FOR KOFK...KLNK AND KOMA.
QUIET WEATHER SHOULD DOMINATE DURING MOST OF THE TAF PERIOD WITH VFR
CONDITIONS...FEW CLOUDS...AND LIGHT WINDS. A WEAK COLD FRONT WILL
SLOWLY MOVE THROUGH THE REGION THIS EVENING CAUSING WINDS TO SHIFT
TO THE NORTH. THE FRONT MAY TRIGGER ISOLATED THUNDERSTORMS OVER
SOUTHERN NEBRASKA THIS EVENING...BUT ANY STORMS THAT DEVELOP SHOULD
REMAIN SOUTH OF KOMA AND KLNK.
DENSITY ALTITUDE WILL BE NOTABLY HIGH GIVEN THE HOT AND HUMID
AIRMASS IN PLACE THIS AFTERNOON.
NIETFELD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ045-052-053-067-
068-088>093.
IA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR IAZ055-056-069-079-
080-090-091.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
154 PM EDT TUE JUL 9 2013
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE INTO THURSDAY, AS A SERIES OF
DISTURBANCES COMBINE WITH A WARM MOIST AIRMASS OVER OUR AREA TO
PRODUCE OCCASIONAL SHOWERS AND THUNDERSTORMS. DRIER AND COOLER AIR
WILL FINALLY ARRIVE ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
GRIDS IN GOOD SHAPE. SMALL ADJUSTMENTS MADE TO THE POPS BUT IN
GENERAL IT LOOKED GOOD. SCATTERED SHOWER MOVING INTO STEUBEN NOW
WILL INCREASE IN COVERAGE AND TSTORMS WILL JOIN THEM. SEVERE
POTENTIAL MARGINAL BUT SOME SHOWERS AND TSTORMS WILL HAVE HEAVY
RAIN. STORM MOTION ONLY SLIGHTLY BETTER THAN YESTERDAY AT 10 TO 15
MPH. TEMPS ADJUSTED UP IN THE SE WHERE SOME SUNSHINE HAS PUSHED
TEMPS INTO THE U70S ALREADY.
UPDATED AT 630 AM. JUST A FEW MINOR TWEAKS TO THE FORECAST TO
ACCOUNT FOR THE LATEST TRENDS. HAVE ADDED PATCHY FOG TO SOUTHERN
NY AND NORTHERN PA THROUGH 13Z. ALSO RADAR IS DETECTING A FEW
SPRINKLES OR LIGHT SHOWERS OVER NORTHERN STEUBEN COUNTY. THESE
SHOWERS ARE DIMINISHING AS THEY MOVE EAST AND ARE NOT EXPECTED TO
REACH AS FAR EAST AS EVEN ELMIRA OR SYRACUSE THROUGH 9 AM.
PREVIOUS DISCUSSION IS BELOW.
LATEST WATER VAPOR LOOP SHOWS A BAND OF MOISTURE PROGRESSING
EASTWARD ACROSS NY AND PA THIS MORNING WITH A SMALL AREA OF DRYING
JUST TO THE WEST... THEN ANOTHER WAVE OF MOISTURE MOVING EAST
ACROSS THE WESTERN GREAT LAKES. EXPECT EACH OF THESE FEATURES TO
AFFECT OUR AREA THROUGH LATE THIS AFTERNOON. CLOUDS AND SCATTERED
LIGHT SHOWERS WILL OVERSPREAD THE AREA THIS MORNING... THEN EXPECT
SOME CLEARING BY AFTERNOON FOLLOWED BY A ROUND OF SCATTERED
THUNDERSTORMS INTO THIS EVENING. MODELS ALL INDICATE MODEST
SYNOPTIC SCALE FORCING FOR ASCENT MOVING ACROSS THE AREA THIS
AFTERNOON IN THE FORM OF A SFC-700 MB TROUGH AND WEAK WAA. THIS
SHOULD RESULT IN A SLIGHTLY GREATER COVERAGE OF STORMS THIS
AFTERNOON WITH POPS INCREASING TO AROUND 50 PCT.
LATEST RAP FORECAST SOUNDINGS INDICATE MLCAPE VALUES INCREASING TO
BETWEEN 800 AND 1000 J/KG BY LATE THIS AFTERNOON. WIND PROFILES
APPEAR TO BE RATHER LIGHT WTIH ONLY 10 TO 20 KTS OF WIND EXTENDING
UP THROUGH 500 MB. MODEST FORCING AND INSTABILITY ALONG WITH WEAK
WIND SHEAR SHOULD RESULT IN MOSTLY PULSE TYPE STORMS THIS
AFTERNOON WITH NOTHING MORE THAN AN ISOLATED... MARGINAL SEVERE
THREAT. ANY STORM COULD ALSO CONTAIN HEAVY DOWMPOURS ONCE AGAIN AS
PWAT VALUES APPROACH 2.00 INCHES... ALTHOUGH THE SHEAR DOES NOT
APPEAR TO BE STRONG ENOUGH TO SUPPORT ORGANIZED LONG-LASTING
STORMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHOWERS AND THUNDERSTORMS WILL DECREASE IN COVERAGE THIS EVENING
WITH LOSS OF HEATING AND PASSAGE OF THE TROUGH TO THE EAST OF THE
AREA. ANOTHER ROUND OF SHOWERS AND STORMS APPEARS LIKELY ON
WEDNESDAY AS A COLD FRONT APPROACHES FROM THE WEST ALONG WITH MID-
LEVEL HEIGHT FALLS OF 30 TO 50 M ASSOCIATED WITH AN UPPER TROUGH
MOVING EAST ACROSS SOUTHERN CANADA. EXPECT MLCAPE VALUES TO ONCE
AGAIN REACH NEAR 1000 J/KG ACROSS THE AREA WEDNESDAY AFTERNOON...
AND THIS WILL BE ACCOMPANIED BY DEEP LAYER SHEAR INCREASING TO 20
TO 30 KTS WITH THE APPROACH OF THE UPPER LEVEL TROUGH. THIS
SCENARIO WOULD LEAD TO A GREATER CHANCE OF SEVERE WEATHER
WEDNESDAY AFTERNOON WITH SOME LINEAR ORGANIZATION OF THE
CONVECTION ALONG A PRE-FRONTAL TROUGH POSSIBLY RESULTING IN
STRONG DAMAING WINDS. BASED ON THESE FACTORS THE SPC DAY 2
CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS
WEDNESDAY AFTERNOON EXTENDING FROM THE OHIO VALLEY ACROSS NY AND
PA.
MODEL CONSENSUS INDICATES THAT THE COLD FRONT WILL BE MOVING EAST
OF OUR AREA ON THURSDAY WITH THE BEST CHC OF SHOWERS AND STORMS
THURSDAY AFTERNOON EXTENDING FROM EASTERN NY INTO NEW ENGLAND.
STILL A CHC OF SHOWERS AND STORMS WILL EXIST IN OUR AREA
ESPECIALLY EAST OF I-81. SLIGHTLY COOLER AND DRYER AIR WILL FOLLOW
BEHIND THIS FRONT THURSDAY NIGHT INTO FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MIDWEST RDGG TRIES TO BUILD IN DURING THE LONG TERM BUT BOTH THE
GFS AND EURO SHOW PERSISTENT UPR TROFINESS...PRIMARILY OVER THE
ERN ZONES...THRU THE PD. THIS MAY RESULT IN A SCENARIO WHERE THE
FCST AREA EAST OF THE I81 CORRIDOR IS SUSCEPTIPLE TO AFTN CONV
UNDER THE COOL POOL. NORMALLY WLD BE WARY OF BEING SO SPECIFIC IN
THE XNTDD BUT BOTH THE MODELS SHOWING THE UPR LOW IN THE SAME PSN
LEADS TO A HIGHER CONFIDENCE FCST. THE GFS EVENTUALLY FORMS A CLSD
LOW THAT DRFTS SE INTO THE MID ATLANTIC WHILE THE EURO BRIEFLY
FORMS AN UPR LOW BUT REALLY JUST BACKS THE WRN ATLANTIC RDG INTO
THE AREA PUSHING THE CSTLYMOISTURE CONVEYOR WWRD. EFFECT ON THE
SENSIBLE WX IS THE SAME EITHER WAY. A SLOW INCRS IN AFTN TEMPS
ALONG WITH AN INCRSD CHANCE OF MAINLY AFTN SHWRS AND TRWS THRU THE
END OF THE XTNDD PD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
ONCE AGAIN WE SEE SCT CONV DVLPMT THIS AFTN AS AN UPR WV INTERACTS
WITH DAYTIME HTG. BEST CHANCE OF DVLPMT WILL BE ALONG THE SRN TIER
INTO NEPA WHERE BETTER HTG HAS TRIGGERED THE CONV TEMPS. HAVE
INCLUDED A TEMPO GROUP FOR TRWS ACROSS THE CNTRL AND SRN TAFS
SITES. ACTIVITY SHD DIE AGAIN THIS EVENING AS WE LOSE HTG. FOG
DVLPMT SEEMS LIKELY ONCE AGAIN TNGT WITH CROSSOVER TEMPS IN THE
MID AND UPR 60S AND WET GND IN SOME AREAS WITH THE SHWRS. XPCT
LIFR AT ELM DEEP IN THE VLY...MVFR MOST OTER PLACES WITH BRIEF IFR
PSBL. MIXING/CLRG BACK TO VFR AFT SUNRISE WED.
.OUTLOOK...
THU...PRIMARILY VFR BUT WITH RESTRICTIONS IN SCT SHWRS AND TRWS.
IFR WITH OVRNGT VLY FOG PSBL.
FRI/SAT/SUN...VFR WITH BRIEF IFR IN VLY FOG.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE/TAC
NEAR TERM...MSE/TAC
SHORT TERM...MSE
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
257 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK UPPER LEVEL LOW PRESSURE TROUGH WILL HOLD OVER THE EASTERN
U.S. THROUGH WEDNESDAY. A STRONGER UPPER LEVEL TROUGH AND ASSOCIATED
SURFACE COLD FRONT WILL APPROACH THE AREA FROM THE NORTHEAST LATE
WEDNESDAY... AND SWING THROUGH THE REGION THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM TUESDAY...
THROUGH TONIGHT: WATER VAPOR IMAGERY SHOWS A SUBTLE VORTICITY MAX
DROPPING SOUTHEAST THROUGH CENTRAL... AND THIS FEATURE COMBINED WITH
DAYTIME HEATING/DESTABILIZATION (MLCAPE OF 2000-2500 J/KG) AND
ABUNDANT MOISTURE (PW VALUE HAVING REBOUNDED THIS AFTERNOON TO
1-8-2.0 IN.) HAVE LED TO SCATTERED STORMS... MORE NUMEROUS IN THE
SOUTHEAST CWA AS DEPICTED WELL BY EARLIER FORECASTS AND RECENT HRRR
MODEL RUNS. DEEP LAYER BULK SHEAR IS QUITE WEAK THOUGH WITH MARGINAL
D-CAPE... SO ANY PARTICULARLY STRONG STORMS SHOULD REMAIN
ISOLATED... BUT MIXED-PHASE CAPE AROUND 700 J/KG AND INCREASING
MOISTURE IN THE -10C TO -30C LAYER ACCORDING TO RAP FORECAST
SOUNDINGS SUGGESTS A THREAT OF SMALL HAIL WITH ANY STRONG CELL...
AND CERTAINLY LOCALLY HEAVY DOWNPOURS REMAIN A CONCERN GIVEN THE
SLOW MOVEMENT AND INCREASING PW. LOSS OF HEATING AS WELL AS THE
PASSAGE OF THE WEAK WAVE EAST OF THE AREA SHOULD BRING A GRADUAL
DISSIPATION OF CONVECTION BY CLOSE TO MIDNIGHT. FOLLOWING
PERSISTENCE WITH NO SIGNIFICANT CHANGE IN AIR MASS... REDEVELOPMENT
OF STRATUS IS ANTICIPATED ACROSS THE AREA LATE TONIGHT... WITH A
LINGERING THREAT OF ISOLATED SHALLOW SHOWERS MAINLY IN THE SOUTH AND
EAST WHERE ABUNDANT LOW LEVEL MOISTURE PERSISTS. LOWS CLOSE TO LAST
NIGHT... 70-74. -GIH
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 PM TUESDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: LOOKS LIKE MORE OF THE SAME... WITH A
CONTINUED HUMID AIR MASS AND MOIST COLUMN FEATURING PW VALUES OF
1.7-1.9 INCHES IN THE MORNING CLIMBING TO 1.9-2.1 INCHES IN THE
AFTERNOON... HIGHEST EAST. WEAK LEE SURFACE TROUGHING HOLDS IN PLACE
WITH A CONTINUATION OF LIGHT BREEZES FROM THE SW... WHILE IN THE MID
LEVELS... VERY WEAK FLOW FROM THE WNW NEAR THE ILL-DEFINED SHEAR
AXIS ALOFT WILL ALLOW FOR LITTLE TO NO DYNAMIC FORCING FOR ASCENT
THROUGH THE AFTERNOON... ALTHOUGH THIS FLOW DOES INCREASE SLIGHTLY
IN THE EVENING AND OVERNIGHT HOURS AS A STRONG WAVE DIGS INTO THE
MEAN TROUGH OVER THE GREAT LAKES. MLCAPE ONCE AGAIN SHOULD TOP OUT
AROUND 1500-2500 J/KG BUT WITH CONTINUED LOW DEEP-LAYER BULK SHEAR
OF JUST 10-15 KTS... SO EXPECT ANOTHER ROUND OF SCATTERED STORMS
WITH DESTABILIZATION... WITH HIGHEST POPS IN THE WRN CWA WHERE THE
SREF INDICATES THE BEST CHANCE OF MEASURABLE RAIN... BUT ANY STORMS
SHOULD HOLD BELOW SEVERE LIMITS. WILL RETAIN A MENTION OF ISOLATED
SHOWERS OVERNIGHT WITH THE IMPROVING FLOW ALOFT AND LINGERING LOW
LEVEL MOISTURE. HIGHS 86-90 AND LOWS AGAIN 70-74. -GIH
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 255 PM TUESDAY...
THE OVERALL PATTERN FOR THE LONG TERM WILL BE DOMINATED BY A
DEEPENING UPPER LEVEL TROUGH WITH ITS AXIS DIGGING TOWARDS THE EAST
COAST. AT THE SURFACE COASTAL NORTH CAROLINA WILL BE SANDWICHED
BETWEEN A STRENGTHENING SURFACE HIGH THAT WILL MOVE FROM THE GREAT
PLAINS TO THE GREAT LAKES AND THE SLOWLY RETREATING BERMUDA HIGH IN
THE SOUTHWESTERN ATLANTIC. IN BETWEEN A SURFACE LOW MOVING ACROSS
CENTRAL ONTARIO AND QUEBEC WILL SET UP A FRONTAL ZONE THAT WILL
EXTEND DOWN THE EASTERN SEABOARD...EVENTUALLY STALL OUT AND THEN
POTENTIALLY RETROGRADE NEAR THE END OF THE PERIOD. TOWARDS THE END
OF THE PERIOD THE X FACTOR WILL BE THE DEVELOPMENT AND TRACK OF
TROPICAL STORM CHANTAL.
THURSDAY AND FRIDAY: STARTING ON THURSDAY THE FRONTAL ZONE WILL BE
DRAPED ACROSS THE WESTERN PIEDMONT WHICH IS WHERE THE HIGHEST
PRECIPITATION CHANCES WILL BE. WITH PW VALUES IN EXCESS OF 2 INCHES.
CONVECTION FEATURING HEAVY RAIN IS PROBABLE WITH THE LEE TROUGH AND
DIFFERENTIAL HEATING BOUNDARIES THE MAIN FOCI FOR CONVECTION. WILL
KEEP HIGHEST POPS IN THE NW THURSDAY AFTERNOON BUT OVERSPREADING THE
ENTIRE CWA BY THURSDAY NIGHT. BY FRIDAY MORNING THE FOCUS FOR
CONVECTION WILL SHIFT FURTHER EAST AS THE SURFACE HIGH OVER THE
GREAT LAKES BUILDS INTO THE 1020S AND THE BERMUDA HIGH WEAKENS
SLIGHTLY. ONCE REACHING THE COASTAL PLAIN THE FRONT WILL SLOW AND
BECOME STAGNANT KEEPING THE BEST CHANCE FOR RAIN IN THE SOUTHEAST ON
FRIDAY WHERE PW VALUES WILL REMAIN ABOVE 2 INCHES. BACK TOWARDS THE
TRIANGLE PWS WILL DROP TO ABOUT 1.5 INCHES AND COVERAGE AND
INTENSITY OF PRECIPITATION SHOULD WANE. QPF WILL BE TRICKY ONCE
AGAIN AS CONVECTION WILL BE LOCALLY HEAVIER. FOR NOW WILL GO WITH
ABOUT AN INCH FOR THESE TWO DAYS COMBINED WITH SOME LOCALES
POTENTIALLY SEEING 2-3 INCHES IN HEAVIER AND TRAINING STORMS. STORM
TOTAL QPF SHOULD BE GREATER IN THE SOUTHEAST AND DECREASING BACK
TOWARDS THE TRIAD. MAX TEMPERATURES THESE TWO DAYS WILL BE IN THE
MID TO UPPER 80S WITH LOWS IN THE LOWER 70S AND POTENTIALLY SOME
UPPER 60S IN THE NORTHWEST ON FRIDAY NIGHT INTO SATURDAY MORNING AS
THE FRONT PUSHES EASTWARD. DEWPOINTS WILL BE DEPENDENT UPON LOCATION
WITH LOWER 70S COMMON AHEAD OF THE FRONT AND UPPER 60S BEHIND IT.
SATURDAY AND SUNDAY: THE HIGH TO THE NORTH WILL CONTINUE TO
STRENGTHEN KEEPING THE FRONTAL ZONE RESTRICTED TO THE COAST AS A CUT
OFF MESO LOW OFF OF THE NEW ENGLAND COAST WILL TAKE OVER FOR THE
PARENT LOW AND CONTINUE QUICKLY OFF TO THE NORTHEAST. THIS WILL
BEGIN TO WASH OUT THE FRONT A LITTLE. IN ADDITION THE HIGH WILL
BUILD DOWN FROM THE NORTH CAUSING THE FRONTAL ZONE TO TAKE A MORE
WEST TO EAST ORIENTATION. BEST CHANCES FOR PRECIP WILL BE IN THE
SOUTH AND EAST WITH DRIER CONDITIONS TO THE NW. ON SUNDAY WHATS LEFT
OF THE FRONT WILL START TO RETROGRADE BACK OVER THE CWA WITH NEW
MOISTURE TRANSPORT REINFORCEMENTS FROM TROPICAL STORM CHANTAL OR
WHATEVER THE REMNANTS MAY BE AT THAT TIME. PW VALUES WILL ONCE AGAIN
APPROACH 2 INCHES IN THE SOUTHERN HALF OF THE CWA. HIGHS ONCE AGAIN
IN THE MID TO UPPER 80S WITH LOWS UPPER 60S TO LOW 70S.
MONDAY AND TUESDAY: THIS PERIOD REMAINS LOW CONFIDENCE BECAUSE OF
THE UNCERTAINTY IN THE LOCATION AND STRENGTH OF CHANTAL AT THIS
TIME. THE BERMUDA HIGH WILL BEGIN TO MOVE BACK WESTWARD WHICH WILL
HELP TO FUNNEL MOISTURE IN FROM THE ATLANTIC. WILL KEEP CHANCE POPS
THROUGH THE PERIOD WITH HIGHEST CHANCES IN THE SOUTHEAST. TEMPS WILL
REMAIN MID TO UPPER 80S AND LOWS UPPER 60S TO LOW 70S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1245 PM TUESDAY...
MVFR CIGS WILL CONTINUE TO COME AND GO AT CENTRAL NC TAF SITES
THROUGH 20Z AS CLOUDS BASED AT 1-3 THOUSAND FT WILL VARY BETWEEN
SCATTERED AND BROKEN. EXPECT VFR CIGS AFTER 20Z. NUMEROUS SHOWERS
AND STORMS ARE EXPECTED BETWEEN 20Z AND 03Z WITH BEST COVERAGE NEAR
FAY/RWI... FEWER SHOWERS/STORMS AT RDU AND EVEN FEWER (SCATTERED AT
MOST) AT INT/GSO. IN/NEAR THESE STORMS... MVFR/IFR CIGS/VSBYS AND
BRIEF WIND GUSTS OVER 30 MPH ARE POSSIBLE. OTHERWISE... VFR
CONDITIONS AND LIGHT WINDS FROM THE SOUTH OR SW (UNDER 12 KTS) WILL
DOMINATE UNTIL AROUND 07Z... WHEN IFR STRATUS IS EXPECTED TO DEVELOP
ONCE AGAIN... AS HAS OCCURRED ON PREVIOUS MORNINGS. CIGS SHOULD LIFT
SLOWLY TO MVFR BY 16Z-18Z.
LOOKING BEYOND 18Z WEDNESDAY... CIGS ARE EXPECTED TO TREND TO VFR
18Z-20Z WEDNESDAY WITH SCATTERED STORMS DEVELOPING. IFR CONDITIONS
ARE LIKELY TO RETURN AFTER 07Z THURSDAY THROUGH MID MORNING...
LIFTING SLOWLY TO MVFR THEN VFR BY EARLY THURSDAY AFTERNOON.
OCCASIONALLY MVFR CONDITIONS ARE LIKELY WITH NUMEROUS SHOWERS AND
STORMS THURSDAY AFTERNOON THROUGH FRIDAY. MVFR CONDITIONS COULD
LINGER AT FAY THROUGH SUNDAY... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED TO DOMINATE FRIDAY NIGHT THROUGH SUNDAY... ALTHOUGH IFR
STRATUS IS AGAIN LIKELY 07Z-14Z SUNDAY MORNING. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK UPPER LEVEL LOW PRESSURE TROUGH WILL HOLD OVER THE EASTERN
U.S. THROUGH WEDNESDAY. A STRONGER UPPER LEVEL TROUGH AND ASSOCIATED
SURFACE COLD FRONT WILL APPROACH THE AREA FROM THE NORTHEAST LATE
WEDNESDAY... AND SWING THROUGH THE REGION THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM TUESDAY...
THROUGH TONIGHT: WATER VAPOR IMAGERY SHOWS A SUBTLE VORTICITY MAX
DROPPING SOUTHEAST THROUGH CENTRAL... AND THIS FEATURE COMBINED WITH
DAYTIME HEATING/DESTABILIZATION (MLCAPE OF 2000-2500 J/KG) AND
ABUNDANT MOISTURE (PW VALUE HAVING REBOUNDED THIS AFTERNOON TO
1-8-2.0 IN.) HAVE LED TO SCATTERED STORMS... MORE NUMEROUS IN THE
SOUTHEAST CWA AS DEPICTED WELL BY EARLIER FORECASTS AND RECENT HRRR
MODEL RUNS. DEEP LAYER BULK SHEAR IS QUITE WEAK THOUGH WITH MARGINAL
D-CAPE... SO ANY PARTICULARLY STRONG STORMS SHOULD REMAIN
ISOLATED... BUT MIXED-PHASE CAPE AROUND 700 J/KG AND INCREASING
MOISTURE IN THE -10C TO -30C LAYER ACCORDING TO RAP FORECAST
SOUNDINGS SUGGESTS A THREAT OF SMALL HAIL WITH ANY STRONG CELL...
AND CERTAINLY LOCALLY HEAVY DOWNPOURS REMAIN A CONCERN GIVEN THE
SLOW MOVEMENT AND INCREASING PW. LOSS OF HEATING AS WELL AS THE
PASSAGE OF THE WEAK WAVE EAST OF THE AREA SHOULD BRING A GRADUAL
DISSIPATION OF CONVECTION BY CLOSE TO MIDNIGHT. FOLLOWING
PERSISTENCE WITH NO SIGNIFICANT CHANGE IN AIR MASS... REDEVELOPMENT
OF STRATUS IS ANTICIPATED ACROSS THE AREA LATE TONIGHT... WITH A
LINGERING THREAT OF ISOLATED SHALLOW SHOWERS MAINLY IN THE SOUTH AND
EAST WHERE ABUNDANT LOW LEVEL MOISTURE PERSISTS. LOWS CLOSE TO LAST
NIGHT... 70-74. -GIH
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 PM TUESDAY...
FOR WEDNESDAY/WEDNESDAY NIGHT: LOOKS LIKE MORE OF THE SAME... WITH A
CONTINUED HUMID AIR MASS AND MOIST COLUMN FEATURING PW VALUES OF
1.7-1.9 INCHES IN THE MORNING CLIMBING TO 1.9-2.1 INCHES IN THE
AFTERNOON... HIGHEST EAST. WEAK LEE SURFACE TROUGHING HOLDS IN PLACE
WITH A CONTINUATION OF LIGHT BREEZES FROM THE SW... WHILE IN THE MID
LEVELS... VERY WEAK FLOW FROM THE WNW NEAR THE ILL-DEFINED SHEAR
AXIS ALOFT WILL ALLOW FOR LITTLE TO NO DYNAMIC FORCING FOR ASCENT
THROUGH THE AFTERNOON... ALTHOUGH THIS FLOW DOES INCREASE SLIGHTLY
IN THE EVENING AND OVERNIGHT HOURS AS A STRONG WAVE DIGS INTO THE
MEAN TROUGH OVER THE GREAT LAKES. MLCAPE ONCE AGAIN SHOULD TOP OUT
AROUND 1500-2500 J/KG BUT WITH CONTINUED LOW DEEP-LAYER BULK SHEAR
OF JUST 10-15 KTS... SO EXPECT ANOTHER ROUND OF SCATTERED STORMS
WITH DESTABILIZATION... WITH HIGHEST POPS IN THE WRN CWA WHERE THE
SREF INDICATES THE BEST CHANCE OF MEASURABLE RAIN... BUT ANY STORMS
SHOULD HOLD BELOW SEVERE LIMITS. WILL RETAIN A MENTION OF ISOLATED
SHOWERS OVERNIGHT WITH THE IMPROVING FLOW ALOFT AND LINGERING LOW
LEVEL MOISTURE. HIGHS 86-90 AND LOWS AGAIN 70-74. -GIH
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 225 AM TUESDAY...
THURSDAY THROUGH FRIDAY IS EXPECTED TO BE A WET PERIOD ONCE AGAIN.
THE APPROACH OF ANOTHER MID/UPPER TROUGH FROM THE NW COMBINED WITH
THE SURFACE COLD FRONT SETTLING INTO LOWER TO MID 70S DEW POINTS
WILL SET THE STAGE FOR YET ANOTHER COUPLE OF DAYS WITH WIDESPREAD
CONVECTIVE RAINS. THE HIGHEST POP IS EXPECTED ON THURSDAY OVER THE
PIEDMONT INTO PORTIONS OF THE COASTAL PLAIN AND SANDHILLS BY LATE
AFTERNOON/EVENING. CONVECTIVE DEVELOPMENT THURSDAY SHOULD BE AIDED
BY THE LEE TROUGH AND DIFFERENTIAL HEATING ALONG THE MOUNTAINS. THE
FORMER SHOULD RESULT IN GOOD LOW LEVEL CONVERGENCE WITH PRECIPITABLE
WATER VALUES INCREASING TO BETWEEN 1.8 AND 2 INCHES FAVORING HEAVY
RAINERS SPREADING OFF THE BLUE RIDGE OUT OVER THE PIEDMONT BY EARLY
AFTERNOON. ADDITIONAL DEVELOPMENT SHOULD OCCUR ALONG THE LEE TROUGH
AND NUMEROUS CONVECTIVE OUTFLOWS DURING THE MID TO LATE AFTERNOON
EASTWARD THROUGH THE PIEDMONT AND COASTAL PLAIN. SINCE CATEGORICAL
POP ARE IN PLACE... NO NEED FOR ADJUSTMENTS. QPF OF 1 TO LOCALLY 2
INCHES EXPECTED 12Z THU THROUGH 12 FRI.
THE HEAVY RAIN THREAT WITH DEEP CONVECTION SHOULD SHIFT SLOWLY SE
THROUGH THE REGION REACHING THE SANDHILLS AND COASTAL PLAIN THURSDAY
NIGHT... WHILE LINGERING IN THE PIEDMONT. THEN FRIDAY... NUMEROUS
SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP... ALONG AND AHEAD OF
THE LEFT-OVER CONVECTIVE BOUNDARIES/COLD FRONT. IT APPEARS THAT THE
NW PIEDMONT SHOULD HAVE THE LOWER POP (BUT STILL IN THE LIKELY RANGE
FRIDAY). TO THE EAST AND SOUTH... THROUGH MUCH OF CENTRAL AND
EASTERN NC... NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED AS THE
COLD FRONT SLOWS TO A CRAWL... FOCUSING HIGH PW`S OF 2+ INCHES...
AND LOW LEVEL CONVERGENCE. QPF OF 1.5 TO 2 INCHES LOOKS A GOOD
BET... WITH LOCALLY HIGHER TOTALS. THIS WOULD GIVE QPF 2 DAY TOTALS
OF 2 TO 4 INCHES... NOT WHAT AGRICULTURAL INTERESTS NEED AT THIS
POINT.
FRIDAY NIGHT AND SATURDAY... THE COLD FRONT SHOULD STALL OVER THE
COASTAL PLAIN... WHERE THE HIGHEST POP WILL RESIDE. LOCALLY HEAVY
RAIN THREAT WILL CONTINUE. NUMEROUS SHOWERS AND THUNDERSTORMS SHOULD
BECOME MORE SCATTERED BY SATURDAY ACROSS THE NW PIEDMONT (AWAY FROM
THE STALLED BOUNDARY TO THE SE). LOWS 70-73. HIGHS LOWER TO MID 80S.
SUNDAY AND MONDAY... THE FOCUS TURNS TO THE EVOLUTION OF TS CHANTAL.
IT APPEARS THAT THE BEST FORECAST FOR OUR REGION WOULD BE TO FOLLOW
THE ENSEMBLE MEANS AND MODEL TRENDS. THE ANTECEDENT VERY WET
CONDITIONS OVER OUR REGION CERTAINLY WOULD BE PROBLEMATIC TO SAY THE
LEAST SHOULD CHANTAL BECOME AN ISSUE FOR NC.
HOWEVER... THE ENSEMBLES GENERALLY TURN WHAT IS LEFT OF THIS SYSTEM
WESTWARD AS HEIGHTS ARE FORECAST TO RISE ALONG THE EAST COAST FROM
BUILDING WESTERN ATLANTIC RIDGING BY SUNDAY AND MONDAY. AS OF THIS
FORECAST... IT APPEARS THAT MID/UPPER RIDGING OVER THE WESTERN
ATLANTIC MAY BUILD WESTWARD INTO EASTERN NC ENOUGH TO STEER THIS
SYSTEM WESTWARD (GULF COAST) BY SUNDAY AND MONDAY. THIS WOULD ALLOW
THE NUMEROUS SHOWERS AND STORMS TO BECOME SCATTERED... MAINLY
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY FOR OUR
REGION. HIGHS WOULD ALSO GO UP TO NEAR NORMAL BY THEN AS WELL. LOWS
70-73. HIGHS 85-88.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1245 PM TUESDAY...
MVFR CIGS WILL CONTINUE TO COME AND GO AT CENTRAL NC TAF SITES
THROUGH 20Z AS CLOUDS BASED AT 1-3 THOUSAND FT WILL VARY BETWEEN
SCATTERED AND BROKEN. EXPECT VFR CIGS AFTER 20Z. NUMEROUS SHOWERS
AND STORMS ARE EXPECTED BETWEEN 20Z AND 03Z WITH BEST COVERAGE NEAR
FAY/RWI... FEWER SHOWERS/STORMS AT RDU AND EVEN FEWER (SCATTERED AT
MOST) AT INT/GSO. IN/NEAR THESE STORMS... MVFR/IFR CIGS/VSBYS AND
BRIEF WIND GUSTS OVER 30 MPH ARE POSSIBLE. OTHERWISE... VFR
CONDITIONS AND LIGHT WINDS FROM THE SOUTH OR SW (UNDER 12 KTS) WILL
DOMINATE UNTIL AROUND 07Z... WHEN IFR STRATUS IS EXPECTED TO DEVELOP
ONCE AGAIN... AS HAS OCCURRED ON PREVIOUS MORNINGS. CIGS SHOULD LIFT
SLOWLY TO MVFR BY 16Z-18Z.
LOOKING BEYOND 18Z WEDNESDAY... CIGS ARE EXPECTED TO TREND TO VFR
18Z-20Z WEDNESDAY WITH SCATTERED STORMS DEVELOPING. IFR CONDITIONS
ARE LIKELY TO RETURN AFTER 07Z THURSDAY THROUGH MID MORNING...
LIFTING SLOWLY TO MVFR THEN VFR BY EARLY THURSDAY AFTERNOON.
OCCASIONALLY MVFR CONDITIONS ARE LIKELY WITH NUMEROUS SHOWERS AND
STORMS THURSDAY AFTERNOON THROUGH FRIDAY. MVFR CONDITIONS COULD
LINGER AT FAY THROUGH SUNDAY... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED TO DOMINATE FRIDAY NIGHT THROUGH SUNDAY... ALTHOUGH IFR
STRATUS IS AGAIN LIKELY 07Z-14Z SUNDAY MORNING. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1245 PM EDT TUE JUL 9 2013
.SYNOPSIS...
A WEAK UPPER LEVEL LOW PRESSURE TROUGH WILL HOLD OVER THE EASTERN
U.S. THROUGH WEDNESDAY. A STRONGER UPPER LEVEL TROUGH AND ASSOCIATED
SURFACE COLD FRONT WILL APPROACH THE AREA FROM THE NORTHEAST LATE
WEDNESDAY... AND SWING THROUGH THE REGION THURSDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM TUESDAY...
REST OF TODAY THROUGH TONIGHT: QUITE A BIT OF STRATUS (ABOUT 500 FT
THICK ACCORDING TO PILOT REPORTS) IS HOLDING OVER THE AREA...
PARTICULARY NRN/WRN AREAS. WATER VAPOR IMAGERY SHOWS A SUBTLE
VORTICITY MAX DROPPING THROUGH CENTRAL VA INTO NRN NC... ON THE
HEELS OF ANOTHER WAVE NOW SUPPORTING SLOW-MOVING THUNDERSTORM
CLUSTERS NEAR THE COAST. THE LATEST HRRR RUNS SHOW SCATTERED TO
NUMEROUS STORMS DEVELOPING OVER THE SRN/ERN PORTIONS OF THE FORECAST
AREA... PERHAPS A RESPONSE TO BOTH GREATER HEATING IN THIS AREA THIS
MORNING AND THE PASSAGE OF THIS WEAK WAVE. CURRENT FORECAST... WITH
MINOR ADJUSTMENTS IN TIMING AND AREA... HINTS AT THIS SCENARIO AND
LOOKS VERY REASONABLE GIVEN THE SHORT TERM TRENDS. CINH IS QUICKLY
ERODING WITH MLCAPE ALREADY AT 1500 J/KG... BUT WITH LOW DEEP-LAYER
BULK SHEAR AND MEANDERING MOVEMENT... STORMS SHOULD STAY BELOW
SEVERE LIMITS... BUT THE RISK OF LOCALLY HEAVY DOWNPOURS WILL
PERSIST. LOW LEVEL THICKNESSES FAVOR HIGHS IN THE UPPER 80S... IN
LINE WITH LATEST STATISTICAL GUIDANCE AND EXISTING FORECAST...
FACTORING IN VARIABLY CLOUDY SKIES. -GIH
THOUGH COVERAGE AND INTENSITY SHOULD DIMINISH WITH NOCTURNAL
COOLING...THE VERY MOIST AND WEAKLY CONDITIONALLY UNSTABLE AIR MASS
OVERNIGHT WILL LIKELY SUPPORT A FEW SHOWERS. LOWS IN THE LOWER 70S.
-MWS
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 315 AM TUESDAY...
WEDNESDAY AND WEDNESDAY NIGHT: PERSISTENCE OVERALL...WITH CONTINUED
BERMUDA HIGH PRESSURE EXTENDING WESTWARD INTO THE CAROLINAS...
BENEATH TROUGHING/CYCLONIC FLOW IN THE MID LEVELS. THIS
PATTERN...AMIDST A VERY MOIST AND UNCAPPED BOUNDARY LAYER...SHOULD
AGAIN PRODUCE SCATTERED SHOWERS AND STORMS MAXIMIZED WITH DIURNAL
HEATING. IN ADDITION...GULF MOISTURE...WHICH WILL HAVE BEEN
PREVIOUSLY LIMITED OWING TO RIDGING OVER THE GOM AND GULF COAST
STATES...WILL HAVE CIRCUMVENTED THE RIDGE AND ARRIVE IN
STRENGTHENING H85 WESTERLY FLOW LATE WED AND ESPECIALLY WED NIGHT.
THIS REGIME...AS WELL AS INCREASING HEIGHT FALLS ALOFT DOWNSTREAM OF
A POWERFUL TROUGH AMPLIFYING THROUGH THE GREAT LAKES...MAY SUPPORT
ADDITIONAL CONVECTION OVERNIGHT...MAINLY OVER THE WESTERN PIEDMONT
WHERE THE EFFECTS OF THE MOISTURE TRANSPORT/ISENTROPIC UPGLIDE WILL
OCCUR FIRST. PERSISTENCE TEMPS IN THE UPPER 80S TO AROUND 90...AND
LOWER 70S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 225 AM TUESDAY...
THURSDAY THROUGH FRIDAY IS EXPECTED TO BE A WET PERIOD ONCE AGAIN.
THE APPROACH OF ANOTHER MID/UPPER TROUGH FROM THE NW COMBINED WITH
THE SURFACE COLD FRONT SETTLING INTO LOWER TO MID 70S DEW POINTS
WILL SET THE STAGE FOR YET ANOTHER COUPLE OF DAYS WITH WIDESPREAD
CONVECTIVE RAINS. THE HIGHEST POP IS EXPECTED ON THURSDAY OVER THE
PIEDMONT INTO PORTIONS OF THE COASTAL PLAIN AND SANDHILLS BY LATE
AFTERNOON/EVENING. CONVECTIVE DEVELOPMENT THURSDAY SHOULD BE AIDED
BY THE LEE TROUGH AND DIFFERENTIAL HEATING ALONG THE MOUNTAINS. THE
FORMER SHOULD RESULT IN GOOD LOW LEVEL CONVERGENCE WITH PRECIPITABLE
WATER VALUES INCREASING TO BETWEEN 1.8 AND 2 INCHES FAVORING HEAVY
RAINERS SPREADING OFF THE BLUE RIDGE OUT OVER THE PIEDMONT BY EARLY
AFTERNOON. ADDITIONAL DEVELOPMENT SHOULD OCCUR ALONG THE LEE TROUGH
AND NUMEROUS CONVECTIVE OUTFLOWS DURING THE MID TO LATE AFTERNOON
EASTWARD THROUGH THE PIEDMONT AND COASTAL PLAIN. SINCE CATEGORICAL
POP ARE IN PLACE... NO NEED FOR ADJUSTMENTS. QPF OF 1 TO LOCALLY 2
INCHES EXPECTED 12Z THU THROUGH 12 FRI.
THE HEAVY RAIN THREAT WITH DEEP CONVECTION SHOULD SHIFT SLOWLY SE
THROUGH THE REGION REACHING THE SANDHILLS AND COASTAL PLAIN THURSDAY
NIGHT... WHILE LINGERING IN THE PIEDMONT. THEN FRIDAY... NUMEROUS
SHOWERS AND THUNDERSTORMS WILL AGAIN DEVELOP... ALONG AND AHEAD OF
THE LEFT-OVER CONVECTIVE BOUNDARIES/COLD FRONT. IT APPEARS THAT THE
NW PIEDMONT SHOULD HAVE THE LOWER POP (BUT STILL IN THE LIKELY RANGE
FRIDAY). TO THE EAST AND SOUTH... THROUGH MUCH OF CENTRAL AND
EASTERN NC... NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED AS THE
COLD FRONT SLOWS TO A CRAWL... FOCUSING HIGH PW`S OF 2+ INCHES...
AND LOW LEVEL CONVERGENCE. QPF OF 1.5 TO 2 INCHES LOOKS A GOOD
BET... WITH LOCALLY HIGHER TOTALS. THIS WOULD GIVE QPF 2 DAY TOTALS
OF 2 TO 4 INCHES... NOT WHAT AGRICULTURAL INTERESTS NEED AT THIS
POINT.
FRIDAY NIGHT AND SATURDAY... THE COLD FRONT SHOULD STALL OVER THE
COASTAL PLAIN... WHERE THE HIGHEST POP WILL RESIDE. LOCALLY HEAVY
RAIN THREAT WILL CONTINUE. NUMEROUS SHOWERS AND THUNDERSTORMS SHOULD
BECOME MORE SCATTERED BY SATURDAY ACROSS THE NW PIEDMONT (AWAY FROM
THE STALLED BOUNDARY TO THE SE). LOWS 70-73. HIGHS LOWER TO MID 80S.
SUNDAY AND MONDAY... THE FOCUS TURNS TO THE EVOLUTION OF TS CHANTAL.
IT APPEARS THAT THE BEST FORECAST FOR OUR REGION WOULD BE TO FOLLOW
THE ENSEMBLE MEANS AND MODEL TRENDS. THE ANTECEDENT VERY WET
CONDITIONS OVER OUR REGION CERTAINLY WOULD BE PROBLEMATIC TO SAY THE
LEAST SHOULD CHANTAL BECOME AN ISSUE FOR NC.
HOWEVER... THE ENSEMBLES GENERALLY TURN WHAT IS LEFT OF THIS SYSTEM
WESTWARD AS HEIGHTS ARE FORECAST TO RISE ALONG THE EAST COAST FROM
BUILDING WESTERN ATLANTIC RIDGING BY SUNDAY AND MONDAY. AS OF THIS
FORECAST... IT APPEARS THAT MID/UPPER RIDGING OVER THE WESTERN
ATLANTIC MAY BUILD WESTWARD INTO EASTERN NC ENOUGH TO STEER THIS
SYSTEM WESTWARD (GULF COAST) BY SUNDAY AND MONDAY. THIS WOULD ALLOW
THE NUMEROUS SHOWERS AND STORMS TO BECOME SCATTERED... MAINLY
DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY FOR OUR
REGION. HIGHS WOULD ALSO GO UP TO NEAR NORMAL BY THEN AS WELL. LOWS
70-73. HIGHS 85-88.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1245 PM TUESDAY...
MVFR CIGS WILL CONTINUE TO COME AND GO AT CENTRAL NC TAF SITES
THROUGH 20Z AS CLOUDS BASED AT 1-3 THOUSAND FT WILL VARY BETWEEN
SCATTERED AND BROKEN. EXPECT VFR CIGS AFTER 20Z. NUMEROUS SHOWERS
AND STORMS ARE EXPECTED BETWEEN 20Z AND 03Z WITH BEST COVERAGE NEAR
FAY/RWI... FEWER SHOWERS/STORMS AT RDU AND EVEN FEWER (SCATTERED AT
MOST) AT INT/GSO. IN/NEAR THESE STORMS... MVFR/IFR CIGS/VSBYS AND
BRIEF WIND GUSTS OVER 30 MPH ARE POSSIBLE. OTHERWISE... VFR
CONDITIONS AND LIGHT WINDS FROM THE SOUTH OR SW (UNDER 12 KTS) WILL
DOMINATE UNTIL AROUND 07Z... WHEN IFR STRATUS IS EXPECTED TO DEVELOP
ONCE AGAIN... AS HAS OCCURRED ON PREVIOUS MORNINGS. CIGS SHOULD LIFT
SLOWLY TO MVFR BY 16Z-18Z.
LOOKING BEYOND 18Z WEDNESDAY... CIGS ARE EXPECTED TO TREND TO VFR
18Z-20Z WEDNESDAY WITH SCATTERED STORMS DEVELOPING. IFR CONDITIONS
ARE LIKELY TO RETURN AFTER 07Z THURSDAY THROUGH MID MORNING...
LIFTING SLOWLY TO MVFR THEN VFR BY EARLY THURSDAY AFTERNOON.
OCCASIONALLY MVFR CONDITIONS ARE LIKELY WITH NUMEROUS SHOWERS AND
STORMS THURSDAY AFTERNOON THROUGH FRIDAY. MVFR CONDITIONS COULD
LINGER AT FAY THROUGH SUNDAY... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED TO DOMINATE FRIDAY NIGHT THROUGH SUNDAY... ALTHOUGH IFR
STRATUS IS AGAIN LIKELY 07Z-14Z SUNDAY MORNING. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/MWS
SHORT TERM...MWS
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
451 PM CDT TUE JUL 9 2013
.MESOSCALE DISCUSSION...
ISSUED AT 451 PM CDT TUE JUL 9 2013
DESPITE DECENT RECOVERY IN TEMPERATURES AFTER THE PASSAGE OF THE
MORNING/MIDDAY CONVECTION...SUCH AS LA CROSSE CLIMBING UP TO 90F
WITH A DEWPOINT OF 72F...CONVECTION IS DEFINITELY STRUGGLING. TWO
THINGS ARE GOING ON HERE...
1. MASSIVE DRYING SEEN ON WATER VAPOR IN THE WAKE OF THE
MORNING/MIDDAY CONVECTION AND ASSOCIATED MCV/SHORTWAVE TROUGH.
THIS DRYING IMPLIES SUBSIDENCE.
2. A SURGE OF WARMER AIR AT 750MB ACCOMPANYING THE MASSIVE DRYING.
THIS IS SEEN NICELY ON 20Z TAMDAR SOUNDINGS AT MPX AND DMX WHICH
ARE 14C AND 16C RESPECTIVELY. THE LOWER TEMPERATURES AT MPX HAVE
ALLOWED SOME CONVECTION TO FIRE NORTH OF LA
CROSSE...HOWEVER...OVERALL THESE VALUES ARE PUTTING A CAP TO
CONVECTION. MODIFYING A RAP SOUNDING AT 22Z FOR LA CROSSE WITH THE
CURRENT SURFACE TEMP/DEWPOINTS AND A 16C 750MB TEMP STILL SHOWS A
LITTLE CAPPING TO OVERCOME.
ANTICIPATING LITTLE CHANGE IN CONVECTIVE ACTIVITY THROUGH THE NEXT
COUPLE HOURS AS WE STAY IN THE SUBSIDENCE/DRYING ALOFT AND WARM
750MB AIR SPREADS EAST. ADDITIONALLY...WE WILL BE APPROACHING THE
END OF HEATING SHORTLY...WHICH IN TURN WILL ONLY INCREASE THE CIN
HEADING THROUGH THE EVENING.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 250 PM CDT TUE JUL 9 2013
AN UPPER LEVEL SHORTWAVE TROUGH WAS TRACKING EAST ACROSS THE
NORTHERN PLAINS THIS AFTERNOON...AND WILL WORK ACROSS NORTHERN PARTS
OF THE REGION THIS EVENING. AHEAD OF THE UPPER LEVEL ENERGY AND AT
THE SFC...AN ASSOCIATED FRONTAL BOUNDARY IS PROGGED TO MOVE OVER THE
LOCAL FORECAST AREA BY 00Z...EXITING INTO EASTERN WI AFTER 06Z.
MORNING/EARLY AFTERNOON CONVECTION HAS WORKED OVER THE ATMOSPHERE
PRETTY GOOD...AND NOT A LOT OF TIME/SPACE TO RE-ESTABLISH SOME
INSTABILTY AHEAD OF THE FRONT. MESO MODELS NOT BULLISH ON FIRING
MUCH/IF ANY CONVECTION ALONG THE SFC BOUNDARY AS IT SWEEPS THROUGH
THIS EVENING. THINK THIS IS THE WAY TO GO. THE CAVEAT...OF
COURSE...IS IF THE ATMOSPHERE CAN JUICE BACK UP...THE STORM CHANCES
WOULD INCREASE...AND THERE COULD BE A STRONG/SEVERE RISK. LATEST
RADAR IMAGERY HAS SHOWN SOME DEVELOPMENT OVER NORTHWEST
WI...ASSOCIATED WITH AN MCV FROM THE MORNING CONVECTION. NOT MUCH
ELSEWHERE...ALTHOUGH SOME AGGRAVATED CU PER SATELLITE IMAGERY COULD
EVENTUALLY BECOME SHOWERS/STORMS. WILL MONITOR TRENDS...BUT WILL
STEER THE FORECAST FOR LESS PCPN CHANCES.
HIGH PRESSURE STARTS TO BUILD IN FROM THE NORTHERN PLAINS ON
WED...CLEARING OUT THE SKIES AND USHERING IN A MUCH COOLER AND DRIER
AIRMASS.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 250 PM CDT TUE JUL 9 2013
HIGH PRESSURE WILL BE THE MAIN WEATHER FEATURE FOR THE REGION INTO
FRIDAY...WITH RELATIVELY COOLER/LESS HUMID AIR FOR THE REST OF THE
WORK WEEK.
UPPER LEVEL SHORTWAVE TROUGH WILL DRIVE EASTWARD ACROSS SOUTHERN
CANADA FOR THE UPCOMING WEEKEND. WHILE THE BULK OF THE UPPER LEVEL
ENERGY WILL HOLD WELL NORTH OF THE LOCAL AREA...THIS SYSTEM WILL
DRAG A SFC FRONT ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FRI
NIGHT/SAT. THE GFS/ECMWF LAYS UP THE FRONT FROM WEST TO EAST AND
HANGS IT ACROSS THE REGION INTO THE EARLY PART OF NEXT WEEK. GOOD
LOW LEVEL MOISTURE RETURN INTO THE BOUNDARY WILL HELP FUEL
SHOWERS/STORMS...WITH SOME INSTABILITY TO POWER STORMS. WIND SHEAR
AT THIS TIME LOOKS MORE NORTH OF THE FRONT. THIS SCENARIO COULD
BRING HEAVY RAINS TO PARTS OF THE REGION...WITH TRAINING STORMS AND
A GOOD TAP INTO MOISTURE. THAT SAID...THERE IS UNCERTAINTY WITH
WHERE THE FRONT WILL REST AND IF IT WAVERS NORTH-SOUTH. WILL STICK
WITH A CONSENSUS/EC BLEND FOR THE RAIN CHANCES...FAVORING RAIN
CHANCES TO THE NORTH.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
108 PM CDT TUE JUL 9 2013
PRIMARY CONCERN FOR AVIATION IS THE RISK FOR ANY NEW CONVECTION
LATE THIS AFTERNOON OR EARLY EVENING. WIND SHIFT WITH THE FRONTAL
PASSAGE AND ALSO THE POTENTIAL FOR MVFR CEILINGS ALSO OF NOTE.
FIRST ROUND OF CONVECTION HAS PUSHED EAST OF THE TAF SITES...BUT
THE COLD FRONT HAS NOT YET PASSED. A LINE OF CUMULUS DENOTES ITS
POSITION ACROSS SOUTH-CENTRAL MN AS OF 18Z. STILL A RISK FOR SOME
CONVECTION WITH INCREASING INSTABILITY WITH AFTERNOON HEATING AND
ASSISTANCE FROM UPPER LEVEL SHORT WAVE TROUGH MOVING ACROSS MN.
BUT WIND SHEAR AND CONVERGENCE INTO THE FRONT NOT IDEAL. STILL
KEPT A SMALL RISK IN THE FORECAST. ALSO SEE SOME POST FRONTAL MVFR
CEILINGS ON SATELLITE...AND THIS COULD IMPACT THE TAF SITES FOR A
TIME. CLEARING OVERNIGHT HOWEVER WITH VFR CONDITIONS ANTICIPATED
TO PREVAIL INTO WEDNESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
MESOSCALE...AJ
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
113 PM CDT TUE JUL 9 2013
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 315 AM CDT TUE JUL 9 2013
MAIN CONCERN WILL BE TRACK OF PLAINS THUNDERSTORM COMPLEX THIS
MORNING/TODAY...THEN SEVERE POTENTIAL GOING THIS AFTERNOON.
LOOP OF WATER VAPOR IMAGERY THIS MORNING ALONG WITH RAP 500MB
ANALYSIS SHOWS A FAIRLY VIGOROUS MID-LEVEL TROUGH MOVING OUT OF MT
INTO THE DAKOTAS...WHILE ANOTHER WEAKER WAVE WAS NOTED ACROSS
CENTRAL NEB. 925-850MB MOISTURE TRANSPORT AHEAD OF THESE WAVES WAS
PRODUCING A BROKEN LINE COMPLEX OF THUNDERSTORMS EXTENDING FROM
EASTERN ND/SD...INTO EASTERN NEB. THIS COMPLEX OF STORMS WAS MOVING
EAST AT 30-35KT...MAKING INROADS TOWARD THE AREA. SIMPLE
EXTRAPOLATION BRINGS THIS COMPLEX INTO SOUTHEAST MN/NORTHEAST IA
AROUND 12Z/7AM-ISH.
ARX/HRRR/NMM WRF MODELS DID A PRETTY GOOD JOB INITIALIZING THIS
CONVECTION AND REMAIN IN FAIRLY DECENT AGREEMENT THROUGH THE DAY
TODAY. HAVE TRENDED THE FORECAST TO MATCH UP WITH A BLEND OF THESE
SOLUTIONS. APPEARS THE COMPLEX OF STORMS WILL MAINTAIN
ITSELF...COMING ACROSS THE AREA THIS MORNING AS 925-850MB MOISTURE
TRANSPORT INCREASES/NOSES INTO THE REGION. THIS COMPLEX OF STORMS
HAS A HISTORY OF 30-50KT WINDS ASSOCIATED WITH IT OVER SD.
SO...CANNOT RULE OUT SOME BORDERLINE SEVERE WINDS AS IT ROLLS INTO
OUR AREA. COULD BE INTERESTING GOING INTO THIS AFTERNOON AS THE WRF
MODELS SHOW THIS COMPLEX DEVELOPING A FAIRLY SIGNIFICANT MCV
STRUCTURE. THIS IN TURN HAS THE POTENTIAL OF PRODUCING A
MINI-OUTFLOW/COLD FRONT ON ITS SOUTHWEST FLANK IN THE 18-21Z TIME
FRAME. WITH AMPING SHEAR IN THE 30-40KT RANGE DUE TO THE MCV AND
MORE THAN AMPLE CAPE IN THE 4000-5500J/KG RANGE...LOOKING FOR THE
POSSIBILITY OF A LINE OF SEVERE STORMS WITH DAMAGING WINDS DEVELOPING
ACROSS CENTRAL/SOUTHWEST WI THIS AFTERNOON. THIS OF COURSE WILL ALL
DEPEND ON HOW MUCH CLOUD IS PRESENT WHICH COULD AFFECT THE AMOUNT OF
AVAILABLE INSTABILITY REALIZED. THE POTENTIAL IS DEFINITELY THERE AND
WILL HAVE TO BE WATCHED CLOSELY. ANOTHER THING TO WATCH IS HEAVY
RAINFALL POTENTIAL WITH MUGGY AIRMASS IN PLACE AND PRECIPITABLE WATER
IN THE 2-2.25 INCH RANGE. THIS COULD AID IN TORRENTIAL DOWNPOURS OUT
OF THE STORMS AND SOME LOCALIZED PONDING OF WATER IN POOR DRAINAGE
AREAS.
LOOKING FOR THE MAIN COLD FRONT TO THEN SLIDE SOUTHEAST ACROSS THE
AREA IN THE 00-06Z TIME FRAME. UNCERTAIN ON HOW THIS IS GOING TO
PLAY OUT WITH THE POTENTIAL FOR SEVERE STORMS ALREADY GOING THROUGH
THE AREA THIS AFTERNOON. ATMOSPHERE COULD BE FAIRLY STABILIZED
BEHIND THIS CONVECTION AND COLD FRONT COULD SLIP THROUGH WITH NO
CONVECTION. APPEARS HIGHEST POTENTIAL FOR EVENING CONVECTION MAY BE
ALONG AND NORTH OF I-94 WHERE BETTER 500-300MB PV-ADVECTION WILL
EXIST. EXPECTING COLD FRONT AND ASSOCIATED CONVECTION TO PUSH EAST OF
THE AREA AROUND DAYBREAK AS HIGH PRESSURE BUILDS IN FROM THE
DAKOTAS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 AM CDT TUE JUL 9 2013
HIGH PRESSURE WILL PRODUCE VERY PLEASANT WEATHER CONDITIONS ACROSS
THE AREA WEDNESDAY AND THURSDAY. LOOK FOR HIGHS IN THE 75-80 DEGREE
RANGE ON WEDNESDAY AND UPPER 70S/LOWER 80S ON THURSDAY. MUCH LOWER
HUMIDITY LEVELS WILL ALSO BE NOTED AS DEWPOINTS HOVER IN THE 50S.
PLAN ON WARMER TEMPERATURES ON FRIDAY ALONG WITH INCREASING HUMIDITY
LEVEL AS THE HIGH SLIDES OFF TO THE EAST AND SOUTH WINDS SET UP
ACROSS THE AREA. LOOK FOR HIGHS IN THE 80S WITH A FEW READINGS
FLIRTING WITH THE 90 DEGREE MARK ACROSS SOUTHEAST MN.
EC/GFS ACTUALLY IN PRETTY GOOD AGREEMENT GOING INTO THE WEEKEND.
BOTH MOVE A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER REGION BY
SUNDAY MORNING...THEN HANG IT UP ACROSS WI INTO CENTRAL IA BY
MONDAY. THIS WILL PRODUCE A CHANCE OF SHOWERS AND THUNDERSTORMS FROM
FRIDAY NIGHT STRAIGHT THROUGH MONDAY. OTHERWISE...LOOK FOR
TEMPERATURES TO BE RIGHT AROUND NORMAL LEVELS IN THE 80S.
&&
.AVIATION...THROUGH 18Z WEDNESDAY
108 PM CDT TUE JUL 9 2013
PRIMARY CONCERN FOR AVIATION IS THE RISK FOR ANY NEW CONVECTION
LATE THIS AFTERNOON OR EARLY EVENING. WIND SHIFT WITH THE FRONTAL
PASSAGE AND ALSO THE POTENTIAL FOR MVFR CEILINGS ALSO OF NOTE.
FIRST ROUND OF CONVECTION HAS PUSHED EAST OF THE TAF SITES...BUT
THE COLD FRONT HAS NOT YET PASSED. A LINE OF CUMULUS DENOTES ITS
POSITION ACROSS SOUTH-CENTRAL MN AS OF 18Z. STILL A RISK FOR SOME
CONVECTION WITH INCREASING INSTABILITY WITH AFTERNOON HEATING AND
ASSISTANCE FROM UPPER LEVEL SHORT WAVE TROUGH MOVING ACROSS MN.
BUT WIND SHEAR AND CONVERGENCE INTO THE FRONT NOT IDEAL. STILL
KEPT A SMALL RISK IN THE FORECAST. ALSO SEE SOME POST FRONTAL MVFR
CEILINGS ON SATELLITE...AND THIS COULD IMPACT THE TAF SITES FOR A
TIME. CLEARING OVERNIGHT HOWEVER WITH VFR CONDITIONS ANTICIPATED
TO PREVAIL INTO WEDNESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...MW
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1206 PM CDT TUE JUL 9 2013
.UPDATE...HIGHS AND WX/POPS UPDATED IN THE TODAY PERIOD FOR THE
LATEST TRENDS. MORE SKY COVER THAN PREVIOUSLY EXPECTED...AND NOT
ANTICIPATING MUCH IN IMPROVEMENT. AS SUCH...WITH INSOLATION NOT
BEING AS FAVORABLE...COINCIDING WITH A MCS AND TRAILING STRATIFORM
REGION MOVING THROUGH THE CWA...HIGHS WERE DECREASED 3-4 DEGREES.
THE WX AND POPS IN THE NEAR-TERM WERE UPDATED TO REFLECT THE LEADING
EDGE AND ITS MOVEMENT EAST.
OTHERWISE...REMOVED WORDING OF HEAVY RAIN AND TRW+ THIS LATE
AFTERNOON/EVENING. THE POTENTIAL FOR STRONGER THUNDERSTORMS
DEVELOPING LATE THIS AFTERNOON IS LESSENING. LATEST MESOSCALE
MODELS DONT SHOW MUCH IN REDEVELOPMENT THIS AFTERNOON/EVENING
BESIDES THIS LINE. OF WHICH...THE NEAR-STORM ENVIRONMENT IN WHICH
THE LINE IS MOVING THROUGH IS NOT THAT FAVORABLE FOR SEVERE
WEATHER. A FEW STRONG STORMS THOUGH ARE POSSIBLE. CURRENT THINKING
IS THAT THE ADDITIONAL SKY COVER WILL LIMIT DESTABILIZATION FOR
ACTIVITY LATER ON. SITUATION STILL WARRANTS BEING WATCHED GIVEN
THE RAP STILL SHOWS DECENT POTENTIAL INSTABILITY LATE THIS
AFTERNOON/EVENING AND ON...THOUGH IT LIKELY WONT BE AS ROBUST AS
PROGGED.
&&
.AVIATION/18Z TAFS/...MAIN CONCERN IS LINE OF SHOWERS AND
THUNDERSTORMS TRAVERSING THE CWA WEST TO EAST. AS SEEN FROM
RADAR...LEADING EDGE OF SHOWERS AND THUNDERSTORMS IS CURRENTLY
ALONG A LINE FROM REESEVILLE TO FORT ATKINSON TO JUST WEST OF
JOHNSTOWN CENTER WITH A TRAILING REGION OF STRATIFORM RAIN BEHIND
IT. CIGS AND VISIBILITY ASSOCIATED WITH THESE THUNDERSTORMS ARE
PREDOMINANTLY RIGHT AT OR ABOVE MVFR THRESHOLDS.
LEADING EDGE IS EXPECTED TO REACH KUES AND KMKE BETWEEN 17 AND 18
UTC. AHEAD OF THE LINE IS A LOW STRATUS DECK WITH CIGS AROUND
800-1200 FT...THAT ARE PRESENT AT KMKE...KUES...AND KENW
CURRENTLY. THIS SHOULD GIVE WAY ONCE THE LINE MOVES THROUGH. AFTER
THE THUNDERSTORMS AND SHOWERS MOVE THOUGH...CHANCE FOR MORE
ACTIVITY STILL EXISTS LATER ON. HOWEVER...THE POTENTIAL FOR MORE
SHOWERS AND THUNDERSTORMS IS DECREASING DUE TO INCREASING CLOUD
COVER THAN WHAT WAS PREVIOUSLY EXPECTED. THIS WILL HELP LIMIT THE
CONVECTIVE POTENTIAL LATE THIS AFTERNOON/EVENING. THIS IS FURTHER
SUPPORTED BY MESOSCALE MODELS...AS THEY DO NOT SHOW MUCH IN TERMS
OF DEVELOPMENT LATER ON AFTER THIS LINE PASSES THROUGH.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT TUE JUL 9 2013/
SHORT TERM...
TODAY AND TONIGHT - CONFIDENCE...MEDIUM
LIGHT BOUNDARY LAYER WINDS AND RECENT RAINFALL HAS RESULTED IN AREAS
OF DENSE FOG OVER THE SHEBOYGAN AREA. CALLS TO NEIGHBORING COUNTY
REVEAL AREAS OF DENSE FOG AS WELL. WITH LITTLE CHANGE EXPECTED
THROUGH THE EARLY MORNING...POSTED DENSE FOG ADVY FOR FOUR NORTHEAST
COUNTIES UNTIL 14Z. LIGHT ONSHORE WINDS MAY CAUSE DENSE FOG TO
PERSIST UNTIL LATE MORNING IN THE SHEBOYGAN AREA.
OTHERWISE PATCHY FOG WILL CONTINUE ELSEWHERE THROUGH THE EARLY
MORNING DUE TO THE LIGHT WINDS. APPEARS BRIEF PERIOD OF SHORT WAVE
RIDGING AND SLOWER LOW LEVEL JET WILL RESULT IN DRY CONDITIONS MOST
AREAS TO START THE DAY. HOWEVER WITH WEAK FRONTAL BOUNDARY
MEANDERING IN THE AREA...AND LOW LEVEL INSTABILITY...POSSIBLE AN
ISOLATED THUNDERSTORM COULD DEVELOP THROUGH THE EARLY MORNING.
LEANING TOWARD TWO PERIODS OF CONVECTION AFFECTING SOUTHERN WI FROM
LATE MORNING IN THE WEST INTO THE EVENING.
FORCING FROM UPSTREAM SHORT WAVE TROUGH OVER EASTERN DAKOTAS AND
NEBRASKA WILL JOIN FORCES WITH PIVOTING WEAKER LOW LEVEL JET IN
BRINGING SCATTERED T TO WESTERN CWA BY LATE MORNING...WITH SOME OF
THIS ACTIVITY LIKELY HOLDING TOGETHER AS IT MOVES INTO EASTERN CWA
THIS AFTERNOON. BELIEVE THERE WILL BE ENOUGH TIME FOR ATMOSPHERE TO
DESTABILIZE AHEAD OF APPROACHING COLD FRONT LATE THIS AFTERNOON AND
EVENING. ENHANCED FORCING FROM RIGHT ENTRANCE REGION SHOULD RESULT
IN NUMEROUS CONVECTION ACROSS SRN WI. BULK SHEAR INCREASES FAVORING
MULTICELLS WITH SOME SUPERCELLS BY THE EVENING. HEAVY RAINFALL ALSO
POSSIBLE THIS EVENING WITH WARM CLOUD DEPTH EXCEEDING 10K FEET AND
MBE VELOCITY FALLING TO LESS THAN 10KTS FOR A PERIOD OF TIME DURING
THE STRONGEST FORCING. WILL HOLD OFF ON FLASH FLOOD WATCH AS ONE
HOUR COUNTY RAINFALL FLASH FLOOD GUIDANCE AROUND 2.0 MOST AREAS.
WILL HOWEVER ISSUE ESF FOR POTENTIAL. DECREASING CONVECTION TREND
OVERNIGHT AS COLD FRONT EXITS SOUTHEAST LATE AND UPPER LEVEL JET
PIVOTS EAST.
WEDNESDAY...FORECAST CONFIDENCE HIGH.
THE SURFACE COLD FRONT ASSOCIATED WITH AN UPPER LEVEL TROUGH MOVING
SOUTHEAST THROUGH WISCONSIN WILL CLEAR FAR SOUTHEAST WI BY MID WED
MORNING. ANY SHOWERS OR STORMS LINGERING ALONG THIS FRONT WILL CLEAR
OUT WITH THE FRONTAL PASSAGE. DRIER AIR WILL MOVE INTO SOUTHERN WI
BEHIND THIS FRONT.
NORTHWEST WINDS WILL INCREASE DURING THE DAY AS HIGH PRESSURE BUILDS
INTO THE MIDWEST.
THURSDAY THROUGH FRIDAY...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE WILL SLOWLY DRIFT ACROSS THE GREAT LAKES REGION. LIGHT
WINDS WILL LEAD TO A LAKE BREEZE EACH DAY. SO WHILE INLAND TEMPS
WILL BE 80 TO 83...MAX LAKESHORE TEMPS WILL BE IN THE MID/UPPER 70S.
LONG TERM...
SATURDAY AND BEYOND...FORECAST CONFIDENCE MEDIUM.
RETURN FLOW AROUND THE HIGH WILL BRING INCREASING HEAT AND HUMIDITY
BACK INTO SOUTHERN WISCONSIN FOR THE WEEKEND. THE CONSENSUS BLEND OF
MODELS SEEMS TO BE UNDERDOING THE MAX TEMP FORECAST FOR SAT/SUN
PERIOD...SO ADJUSTED THAT UP A BIT TOWARD MOS GUIDANCE VALUES. 925MB
TEMPS AROUND 21-22C SUGGEST HIGHS IN THE LOWER 80S. DEWPOINTS ARE
EXPECTED TO BE IN THE MID/UPPER 60S.
MODELS ARE SUGGESTING THAT THE EFFECTIVE BOUNDARY TO TRIGGER
THUNDERSTORMS WILL BE LINED UP ACROSS NORTHERN WI WITH THE UPPER JET
SITUATED ALONG THE US/CANADIAN BORDER. THIS MEANS THAT CHANCES FOR
ANY PRECIP IN SOUTHERN WI WILL NOT RETURN UNTIL MONDAY NEXT WEEK OR
EVEN LATER IF/WHEN THAT FRONTAL BOUNDARY SLIPS SOUTHWARD.
IF WE DO NOT GET PRECIP ALONG THAT FRONT MONDAY...WE WILL BE SHUT
OFF FROM RAIN UNTIL LATER IN THE WEEK DUE TO SPRAWLING HIGH PRESSURE
OVER THE CENTER OF THE COUNTRY.
AVIATION/12Z TAFS/...FOG FORMATION PREFERRED OVER STRATUS DUE TO
LIGHT BOUNDARY LAYER WINDS...HOWEVER MAY BE A BRIEF PERIOD OF MVFR
CIGS OR LOWER EARLY THIS MORNING. VSBYS ASSOCD WITH FOG EXPECTED TO
DROP TO MVFR OR POSSIBLY LOWER FOR SEVERAL HOURS AS WELL.
OTRW...SCATTERED CONVECTION EXPECTED TO FIRE THIS AFTERNOON WITH A
SECOND WAVE LIKELY THIS EVENING. CIGS ASSOCD WITH THUNDER LIKELY TO
FLIRT WITH MVFR LEVELS.
MARINE...LIGHT WINDS IN THE SURFACE RIDGE OVER LAKE MICHIGAN AND
HIGH LOW LEVEL MOISTURE HAS RESULTED IN DENSE FOG DEVELOPING OVER
CENTRAL AND NORTHERN LAKE MICHIGAN OVERNIGHT. LOCAL WEB CAMS SHOW
THE DENSE FOG OVER SHEBOYGAN HARBOR...AND 11-3.9 MICRON IMAGERY
SHOWS A SLOW SOUTHWARD DRIFT OF THE STRATUS/FOG AREA. WL POST DENSE
FOG ADVY FOR NORTHERN ZONES THROUGH THE MORNING...AND MAY HAVE TO
ADD SOUTHERN ZONES IF SOUTHWARD DRIFT CONTINUES. LOW LEVEL WINDS
REMAIN LIGHT THROUGH THE MORNING...THEN BEGIN TO PICK UP FROM THE
SOUTH AHEAD OF APPROACHING COLD FRONT. AREAS OF DENSE FOG MAY
PERSIST UNTIL COLD FRONT AND CONVECTION SPREADS IN LATER TODAY OR
TONIGHT...PROMPTING EXTENSION OF DENSE FOG ADVY. SEVERAL PERIODS OF
CONVECTION EXPECTED OVER NEARSHORE WATERS THIS AFTERNOON AND
TONIGHT. BEST CHANCE FOR A PERIOD OF STRONGER WINDS AND LARGE HAIL
LATE AFTERNOON THRU THE MID-EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR WIZ052.
LM...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR LMZ643-644.
&&
$$
UPDATE...ET
TODAY/TONIGHT AND AVIATION/MARINE...MBK
WEDNESDAY THROUGH MONDAY...MRC