Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/25/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
853 AM MST TUE JUL 23 2013
.SYNOPSIS...AN IMPULSE FROM THE EAST WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY AND THURSDAY...OTHERWISE PLENTY OF MOISTURE
ACROSS SOUTHEAST ARIZONA WITH A CHANCE OF MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND.
&&
.DISCUSSION...THIS MORNINGS KTWC SOUNDING CONTINUED TO SHOW A VERY
MOIST AIRMASS IN PLACE...WITH A PRECIPITABLE WATER VALUE OF 1.6
INCHES. MODIFYING THE SOUNDING USING T=97;TD=58 YIELDS A LIFTED
INDEX OF AROUND MINUS 1 AND A CAPE OF AROUND 500 J/KG IF LIFTING THE
PARCEL USING THE MEAN TEMP METHOD...BUT A CAPE OF AROUND 1000 J/KG
IF LIFTED FROM THE SURFACE. THE FLOW ALOFT ON THIS MORNINGS SOUNDING
WAS MEAGER WITH VERY WEAK FLOW FROM THE SURFACE THROUGH AROUND
250MB. THAT SAID...THE STORMS THAT DEVELOP TODAY WILL STRUGGLE TO
SURVIVE WITHOUT ANY MEANS OF ORGANIZATION...SO BRIEF HEAVY RAINERS
THE MAIN CONCERN FOR TODAY...AND MOSTLY IN THE MOUNTAINS.
THE LATEST HRRR SHOWS THE ACTIVITY DEVELOPING ALONG THE NEW MEXICO
BORDER THIS AFTERNOON AND SLOWLY SPREADING WEST...BUT DISSIPATES
BEFORE MAKING IT TO THE TUCSON AREA. THE U OF A WRF NAM SHOWS A
SIMILAR SOLUTION...ALTHOUGH THE ACTIVITY IS NOT AS NUMEROUS AS THE
HRRR. THE WRF GFS HAS THE LEAST COVERAGE. BOTTOM LINE IS THE
ACTIVITY SHOULD BE FOCUSED EAST OF TUCSON TODAY...SO THE INHERITED
POPS LOOK GOOD AND NO CHANGES PLANNED AT THIS TIME.
TEMPS SEEM TO BE ON TRACK...BUT WILL CONTINUE TO MONITOR
OBSERVATIONS AND WILL MAKE CHANGES IF NEEDED.
&&
.AVIATION...VFR CONDITIONS WITH GENERALLY SCT050 SCT-BKN090. ISOLD
SHRA / TSRA AFTER 24/18Z MAINLY EAST OF KTUS. NORMAL DIURNAL WINDS
EXPECTED AND GENERALLY LESS THAN 10 KTS THROUGH EARLY WEDNESDAY OR
24/12Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...PLENTY OF MOISTURE ACROSS SOUTHEAST ARIZONA WITH A
SEASONABLE CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE COMING
WEEKEND. STRONG AND ERRATIC THUNDERSTORM OUTFLOWS AT TIMES...
OTHERWISE NORMAL DIURNAL WIND TRENDS.
&&
.PREVIOUS DISCUSSION...NOT AS MUCH ACTIVITY OVER THE PAST 24 HOURS.
MOISTURE IS STILL THERE WITH PRECIPITABLE WATER VALUES IN THE FAIRLY
ROBUST 1.5 TO 1.6 INCH RANGE FOR MOST OF SOUTHEAST ARIZONA AND
SURFACE DEWPTS SOLIDLY IN THE 60S. MAIN PROBLEM IS LACK OF LARGER
SCALE FORCING AND CURRENTLY VERY WEAK SHEAR AND FLOW ALONG WITH A
LESS THAN FAVORABLE -4C AT H5. WET STORMS THAT TEND TO SIT AND RAIN
FOR A BIT WITH LITTLE ORGANIZATION AND LIMITED VALLEY SUPPORT. SOME
MID LEVEL DRYING AND MODEST SUBSIDENT FIELD IN WESTERN AREAS BEHIND
THE LOW THAT HAS EXITED TOWARD CENTRAL CALIFORNIA AND SOUTHERN
NEVADA TURNING THINGS OFF FOR A BIT OUT THERE.
THE VERY SLOW MOVING EASTERLY IMPULSE IN NORTHERN CHIHUAHUA THAT
HELPED FOCUS THE ABOVE MENTIONED COMPLEX THIS PAST EVENING SHOULD
PROVIDE THE FOCUS FOR OUR NEXT SHOT OF STRONG THUNDERSTORM ACTIVITY.
THE ECMWF HAS BEEN VERY CONSISTENT IN BRINGING IT INTO FAR SOUTHEAST
ARIZONA WEDNESDAY AFTERNOON INTO THURSDAY. AFTER ANOTHER RELATIVE
DOWN DAY TODAY FROM TUCSON WESTWARD...EXPECT A MARKED INCREASE IN
THUNDERSTORM COVERAGE SPREADING FARTHER WEST WITH SOME SUSTAINED
CONVECTION WEDNESDAY NIGHT INTO THURSDAY MORNING.
BY LATE IN THE WEEKEND STRONGER FLOW THROUGH NORTHERN TIER STATES
MAY SEE THE HIGH CENTER RECONSOLIDATE INTO A NEAR BLOCKING POSITION
AT LOWER LATITUDES AND EVEN AS DEEP AS NORTHWEST MEXICO. THIS WOULD
TEND TO BE A RATHER HOT AND RELATIVELY DRIER PATTERN FOR MUCH OF OUR
NECK OF THE WOODS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
CURRENT DISCUSSION...MOLLERE
PREVIOUS DISCUSSION...MEYER/RASMUSSEN
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
212 PM PDT TUE JUL 23 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD BACK OVER THE REGION STARTING
MIDWEEK AND CONTINUE INTO SATURDAY...THIS WILL BRING FAIR SKIES TO
MOST AREAS WITH THE MARINE LAYER LIMITED TO THE COAST BY THE END OF
THE WEEK. A LOW WILL APPROACH THE REGION EARLY NEXT WEEK FOR AN
INCREASE IN CLOUD COVER. THE TEMPERATURES THROUGH THE PERIOD WILL
STAY AROUND NORMAL...WITH FRIDAY FORECASTED TO BE THE WARMEST.
&&
.SHORT TERM (TODAY-FRI)...HAVE MADE MINOR CHANGES THROUGH THE
PERIOD. GUIDANCE INITIALIZED A TROUGH UPSTREAM AND MOISTURE FIELD
OVER THE AREA REASONABLY WELL AND WAS CONSISTENT WITH PREVIOUS RUNS.
THE TROUGH UPSTREAM WILL PERSIST UPSTREAM WHILE A SUBTROPICAL LONG
WAVE RIDGE BUILDS OVER THE AREA THROUGH FRIDAY AND WARMING TREND IS
EXPECTED. INLAND TEMPERATURES WILL LIKELY WARM 3 TO 6 DEGREES ABOVE
SEASONAL NORMAL BY FRIDAY WHILE MARINE LAYER PERSISTS AT THE COAST
TEMPERATURES WILL REMAIN BELOW NORMAL. THE GOES SOUNDER AND RAP HAD
INDICATED DECREASING STABILITY OVER VENTURA/LOS ANGELES MOUNTAINS
AND DESERT AND ISOLATED CUMULUS FIELD HAD DEVELOPED EARLY THIS
AFTERNOON. STABILITY IS EXPECTED TO INCREASE AS MID LEVELS WARM AND
HEIGHTS RISE THROUGH THE EVENING. THE ISOLATED CUMULUS FIELD OVER
THE MOUNTAINS WILL LIKELY DISSIPATE LATE THIS AFTERNOON. ISOLATED
SHOWERS AND THUNDERSTORMS WERE DEVELOPING WELL EAST OF THE AREA
EARLY THIS AFTERNOON AND WERE SHORT LIVED. THE ACTIVITY WILL REMAIN
EAST OF THE AREA AS THE STORMS PROPAGATE GRADUALLY EAST. OTHERWISE
MOISTURE FIELD INITIALIZED OVER MEXICO THIS MORNING WILL GRADUALLY
PROPAGATE WEST THROUGH THE PERIOD.
.LONG TERM (SAT-TUE)...GFS ANALOG GUIDANCE INDICATED LITTLE OR NO
CHANCE OF PRECIPTITION OVER THE AREA SATURDAY. A TROUGH THAT WAS
UPSTREAM OF THE AREA IN THE SHORT TERM IS EXPECTED TO MOVE ASHORE
SATURDAY AND LIMIT THE WESTWARD PROPAGATION OF THE TROPICAL MOISTURE
THAT WILL ARRIVE SOUTHEAST OF THE AREA FRIDAY NIGHT. A COOLING TREND
IS EXPECTED SATURDAY THROUGH SUNDAY WITH TEMPERATURES 4 TO 8 DEGREES
BELOW SEASONAL NORMAL BY SUNDAY. THE MID/UPPER LEVEL TROUGH OF LOW
PRESSURE MAY MODIFY THE MARINE LAYER SUNDAY AND THE MARINE CLOUDS
MAY BECOME SCATTERED MONDAY THROUGH TUESDAY. OTHERWISE A LONG WAVE
SUBTROPICAL RIDGE EAST OF THE AREA WILL REBUILD WHILE SHIFTING WEST
AND A WARMING TREND IS EXPECTED OVER THE AREA MONDAY THROUGH TUESDAY
THOUGH TEMPERATURES ARE EXPECTED TO REMAIN A COUPLE DEGREES BELOW
SEASONAL NORMAL.
&&
.AVIATION...23/1800Z...
MODERATE CONFIDENCE IN 18Z TAFS WITH LITTLE CHANGE EXPECTED IN THE
MARINE LAYER CLOUD COVERAGE OVERNIGHT. FOR KSBA...WEAK OFFSHORE
TRENDS MAY BRING LESS OR LATER LOW CLOUD COVER TO THE SITE.
GENERALLY EXPECT IFR CONDS FOR COASTAL SITES N OF PT
CONCEPTION...KSBA AND KOXR...WITH IFR TO LOW MVFR FOR THE L.A.
COAST. THERE IS A 10-20% CHANCE THAT LOW CIGS WILL MOVE INTO THE SAN
FERNANDO VLY TONIGHT. GUSTY W-SW WINDS FOR THE ANTELOPE VALLEY THIS
AFTERNOON/EVENING.
KLAX...MODERATE TO HIGH CONFIDENCE IN 18Z TAF. HIGH CONFIDENCE IN
STRATUS RETURN TONIGHT...BUT LOWER CONFIDENCE IN FORECAST TIMING AND
HEIGHT OF CIGS. EXPECT A TRANSITION FROM HIGH IFR TO LOW MVFR
OVERNIGHT.
KBUR...MODERATE CONFIDENCE IN 18Z TAF. THERE IS A 20% CHANCE OF SOME
IFR/MVFR CIG/VSBYS RESTRICTIONS OVERNIGHT OR EARLY WED MORNING.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
PUBLIC...30
AVIATION...CS
SYNOPSIS...SS
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS TAUNTON MA
355 PM EDT TUE JUL 23 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY EVENING
HOURS GRADUALLY DISSIPATING. A RENEWED CHANCE OF WET WEATHER
ACTIVITY IS POSSIBLE WEDNESDAY AHEAD OF A SWEEPING COLD FRONT
WHICH WILL EXIT OUT INTO THE WATERS INTO WEDNESDAY NIGHT. THE COLD
FRONT STALLS WELL OFFSHORE THURSDAY...THEN MOVES BACK TOWARD
SOUTHERN NEW ENGLAND FRIDAY AND SATURDAY. ANOTHER COLD FRONT
SWINGS ACROSS FROM THE WEST ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***
AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY
EVENING HOURS GRADUALLY DISSIPATING TOWARDS MIDNIGHT. STARTING TO
SEE DEVELOPING CONGEAL INTO A LINE ALONG A WEAK FRONTAL BOUNDARY
ATTENDANT TO A BROAD AREA OF LOW PRESSURE OVER SOUTHERN NEW
ENGLAND. SOME OF THE CELLS ARE REACHING UP TO 30-40 KFT WITH
SIGNIFICANT DBZ/S. SUBSEQUENTLY...WHILE GUSTY WINDS OF 20 TO 30
MPH ARE EXPECTED WITH STORMS...COULD SEE ISOLATED STRONGER WHICH
COULD LEAD TO WIND DAMAGE.
OTHERWISE THERE CONTINUES THE THREAT OF HEAVY RAIN /WITH HOURLY
RAINFALL RATES UP TO AROUND 1.5 INCHES/ AND FLASH FLOODING BUT
WITH THE THREAT BECOMING MORE ISOLATED...WILL ALLOW THE FLASH
FLOOD WATCH TO DROP AT 8 PM. HRRR MODEL IS STILL DOING WELL IN
INITIALIZING WITH THE CURRENT CONDITIONS AND FORECASTING
EXPECTATIONS. WILL FOLLOW IT CLOSELY FOR THE EVENING FORECAST.
SOUTHWEST WINDS GUSTING ACROSS THE SOUTHCOAST AND ACROSS THE CAPE
WITH GUSTS UP TO AROUND 20 TO 25 MPH. EXPECT WINDS TO DIMINISH
INTO THE EVENING. CLOUDS IN ABUNDANCE...BUT SOME CLEARING IS
POSSIBLE OVER THE WESTERN ZONES. NEVERTHELESS...ABUNDANCE OF
MOISTURE AND SOUTHERLY WIND FLOW PRESENTS THE THREAT OF SOME
PATCHY FOG...ESPECIALLY ALONG THE COASTS. LOWS DOWN TO THE MID-
TO UPPER-70S BY WEDNESDAY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
COLD FRONT SWEEPS THROUGH THE REGION DURING THE MIDDAY HOURS...THE
PROXIMITY OF WHICH WILL BE ROUGHLY ALONG AND PARALLEL TO THE I-95
CORRIDOR AROUND MIDDAY. MAIN QUESTION IS WHETHER WE WILL SEE SOME
WET WEATHER AHEAD OF THE FRONT.
CONSIDERING AVAILABLE MOISTURE /PWATS AROUND 1.25 INCHES/ COUPLED
WITH SUFFICIENT DEEP-LAYER ASCENT AND UNI-DIRECTIONAL WEST-
SOUTHWEST WIND SHEAR /25-30 KTS/...EXPECT SHOWERS AND POSSIBLE
THUNDERSTORMS AHEAD OF THE COLD FRONT IN AN ENVIRONMENT FAVORABLE
FOR UPDRAFT SUSTAINMENT. SOME QUESTION OF AVAILABLE
INSTABILITY...IMPORTANTLY WHETHER CLOUD DECKS WILL BREAK ALLOWING
FOR SUNSHINE. CONFIDENT IN SEEING SUNSHINE WHICH WILL ALLOW HIGHS
AROUND THE MID 80S. WITH THAT FORECAST GUIDANCE SUPPORTS UP TO
1000 J/KG MUCAPE. CONSIDERING...NOT MUCH CONFIDENCE FOR SEVERE
WEATHER THREATS...BUT BELIEVE THERE WILL BE POCKETS OF HEAVY RAIN
WHICH COULD LEAD TO LOCALIZED FLOODING.
GREATEST CONFIDENCE WITH THE THE 23.0Z ECMWF WHICH INITIALIZED WELL
WITH THE MORNING OUTCOMES. 23.12Z HIGH-RES NAM AND 23.09Z SREF
SUPPORT THE ECMWF. NOTABLY DOWNSTREAM TOWARDS THE EASTERN GREAT
LAKES...JUST THE LOW-LEVEL FORCING AHEAD OF THE LEAD IMPULSE ALOFT
IS GENERATING SHOWER AND THUNDERSTORM ACTIVITY.
WEDNESDAY NIGHT...
HIGH PRESSURE BUILDS SOUTH AND EAST OUT OF CANADA. FEEL THE INTERIOR
WILL BE DRY...BUT SHOWERS WILL BE POSSIBLE ALONG THE SOUTH COAST AS
A MID-LEVEL IMPULSE ROTATING THROUGH THE BROADER TROUGH LIFTS
NORTHEAST ALONG THE OFFSHORE FRONTAL BOUNDARY AND DEEPER AXIS OF
MOISTURE. WITH CLEARING NORTH AND WEST...THIS WILL PERMIT LOWS TO
FALL TO AROUND 50 DEGREES...WHILE REMAINING MILD SOUTH AND EAST
TOWARDS THE CLOUDS AND ANTICIPATED SHOWERY WEATHER. NO EXPECTATION
FOR ANY FLOODING WITH SHOWERS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE/PREFERENCES...UPPER RIDGE OVER THE ATLANTIC AND TROUGH
FROM NORTHERN QUEBEC ACROSS THE GREAT LAKES. THE UPPER RIDGE BUILDS
NORTH INTO NEWFOUNDLAND LATE WEEK...THEN DIMINISHES OVER THE
WEEKEND. SHORTWAVE FROM NORTHERN CANADA MOVES AROUND THE UPPER
TROUGH AND FORMS A CLOSED LOW OVER THE GREAT LAKES FOR FRIDAY AND
THE WEEKEND...THEN EJECTS THROUGH QUEBEC AND MAINTAINS A CYCLONIC
FLOW OVER THE NORTHEAST USA THROUGH EARLY NEXT WEEK.
THIS WILL MAINTAIN A SOUTHWEST FLOW ACROSS NEW ENGLAND THROUGH MOST
OF THE PERIOD...WHICH WILL MAKE IT TOUGH FOR THE OFFSHORE STALLED
FRONT TO MOVE FARTHER OFFSHORE. TWO SHORTWAVES MOVE THROUGH THE FLOW
AND ACROSS SOUTHERN NEW ENGLAND. MODEL TIMING HAS VARIED FROM RUN TO
RUN AND SO CONFIDENCE IN THIS TIMING IS REDUCED. ONE SHORTWAVE
MOVES UP THE COAST FRIDAY-SATURDAY...THE OTHER MOVES THROUGH WITH
THE EJECTED LOW AXIS AROUND MONDAY.
CONFIDENCE IN THE BROAD PICTURE...BUT LOW CONFIDENCE IN THE DAY-
BY-DAY DETAILS. A BLEND OF HPC AND GMOS WAS PREFERRED.
THE DAILIES...
THURSDAY... SURFACE HIGH PRESSURE BUILDING TO OUR NORTH WHILE THE
STALLED FRONT REMAINS WELL OFFSHORE. THE RESULT WILL BE A NORTHEAST
FLOW AT THE SURFACE...UNDERLYING THE SOUTHWEST FLOW ALOFT. WE
EXPECT THIS WILL MAINTAIN LOW CLOUDS OVER THE COASTAL PLAIN WITH
PARTLY TO MOSTLY SUNNY SKIES IN THE CT VALLEY/WORCESTER
HILLS/MONADNOCKS. THE AREA ALSO REMAINS IN THE RIGHT ENTRANCE
REGION OF THE UPPER JET AND STABILITY PARAMETERS ARE
MARGINAL...MAINLY ALONG THE SOUTH COAST/ISLANDS. WE WILL MAINTAIN
SLIGHT CHANCE POPS OVER THE SOUTHEAST HALF OF OUR AREA...CHANCE POPS
CLIPPING THE CAPE AND ISLANDS. TEMPS ARE A BLEND OF MAV/MET VALUES.
FRIDAY THROUGH SUNDAY... UPPER SHORTWAVE FROM THE MIDWEST REACHES
THE COAST THURSDAY NIGHT AND MOVES UP ACROSS NEW ENGLAND
FRIDAY/FRIDAY NIGHT. WE WILL AGAIN BE IN THE RIGHT ENTRANCE REGION
OF THE SUPPORTING UPPER JET WHICH WILL PROVIDE VENTING. MODEL
AGREEMENT THAT THIS INDUCES A WAVE ALONG THE STALLED FRONT AND
BRINGS THE WAVE UP THE COAST AND PASSING CAPE COD FRIDAY NIGHT. A 40
KNOT LOW LEVEL JET IS ASSOCIATED WITH THIS WAVE...BUT PASSES WELL
EAST OF CAPE COD. SO THE BULK OF THE LOW LEVEL LIFT WILL REMAIN
EAST OF NEW ENGLAND. EVEN SO...THE UPPER SUPPORT IS ENOUGH TO EXPECT
CHANCE POPS FROM AT LEAST THE CENTRAL HILLS EASTWARD.
THE WAVE MOVES OFF SATURDAY...BUT ANOTHER SURFACE WAVE MAY APPROACH
SUNDAY WHICH SHOULD KEEP A CHANCE OF SHOWERS IN THE NEIGHBORHOOD.
THE UPPER LOW PASSES TO OUR NORTH MONDAY WITH THE TROUGH AXIS MOVING
ACROSS NEW ENGLAND. AT THE SAME TIME A COLD FRONT WILL MOVE THROUGH
THE REGION. WILL CONTINUE CHANCE POPS IN PLACE THROUGH MONDAY.
TUESDAY... HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. THIS
SHOULD DRY THINGS OUT AND BRING MOSTLY CLEAR SKIES. TEMPS AT THE
TOP OF THE MIXED LAYER WILL BE IN THE MID TEENS...SO MAX TEMPS
SHOULD BE IN THE MID 80S...A FEW SPOTS IN THE UPPER 80S POSSIBLE.
&&
.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 /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
18Z UPDATE...
BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.
ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.
A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY-FRIDAY...VFR. MORE CLOUDINESS IN RI/SOUTHEAST MASS WITH
LOWEST CLOUDS OVER THE CAPE AND ISLANDS. RAIN OR RAIN SHOWERS WILL
BE POSSIBLE...ESPECIALLY IN RI AND EASTERN MASS ON FRIDAY. IN-FLIGHT
CONCERN MAY BE DIRECTIONAL WIND SHEAR WITH A NORTHEAST WIND AROUND
10-15 KNOTS AT THE SURFACE AND A SOUTHWEST WIND AT 15-20 KNOTS ABOVE
5000 FEET.
SATURDAY-SUNDAY...COASTAL LOW PRESSURE WILL SPREAD LOW CLOUDS AND
MVFR CONDITIONS INTO THE COASTAL PLAIN. THE BEST CHANCE OF LOW CIGS
WILL BE ON THE CAPE AND ISLANDS...THE SMALLEST CHANCE IN THE
CONNECTICUT VALLEY. RAIN OR RAIN SHOWERS WILL ALSO BE A CONCERN
BOTH DAYS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
SHOWERS AND THUNDERSTORMS WILL IMPACT THE NEAR-COASTAL WATERS INTO
THE EARLY EVENING HOURS...GRADUALLY DISSIPATING INTO THE OUTER
WATERS. HEAVY RAIN WITH REDUCED VISIBILITIES ALONG WITH FREQUENT
LIGHTNING SHOULD BE ANTICIPATED WITH THESE STORMS. GUSTY WINDS
ANTICIPATED WHICH COULD EXCEED GALE FORCE.
OTHERWISE WHILE SOUTHWEST WINDS ARE GUSTING AROUND 20 KTS ACROSS
THE CAPE PRESENTLY...FEEL SUCH WINDS WILL DIMINISH THROUGH THE
EVENING HOURS. WILL HOLD WINDS AND SEAS BELOW SMALL CRAFT ADVISORY
THRESHOLDS. STILL CONCERNS FOR PATCHY FOG ALONG THE SOUTH COAST
WITH THE POTENTIAL FOR VISIBILITIES DOWN TO A QUARTER MILE OR
LESS...BUT HAVE LOW CONFIDENCE AT THIS TIME.
OUTLOOK...THURSDAY THROUGH SUNDAY...
ROUGH SEAS OF 5-6 FEET WILL BE A CONCERN ON THE OUTER WATERS
THURSDAY AND AGAIN SATURDAY. NORTHEAST WINDS WILL GUST 20 TO 25
KNOTS ON THE SOUTHERN AND CAPE COD WATERS THURSDAY THROUGH
SATURDAY. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR THESE
CONDITIONS. SHOWERS THURSDAY...RAIN THEN SPREADS NORTH ACROSS THE
WATERS FOR FRIDAY AND THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
338 PM EDT TUE JUL 23 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY EVENING
HOURS GRADUALLY DISSIPATING. A RENEWED CHANCE OF WET WEATHER
ACTIVITY IS POSSIBLE WEDNESDAY AHEAD OF A SWEEPING COLD FRONT
WHICH WILL EXIT OUT INTO THE WATERS INTO WEDNESDAY NIGHT. COOLER
AND LESS HUMID WEATHER FOLLOWS THEREAFTER FOR THURSDAY AND
FRIDAY. WARMER AIR RETURNS NEXT WEEKEND BEFORE A COLD FRONT BRINGS
SCATTERED SHOWERS/THUNDERSTORMS SUNDAY...POSSIBLY LINGERING INTO
MONDAY
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***
AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY
EVENING HOURS GRADUALLY DISSIPATING TOWARDS MIDNIGHT. STARTING TO
SEE DEVELOPING CONGEAL INTO A LINE ALONG A WEAK FRONTAL BOUNDARY
ATTENDANT TO A BROAD AREA OF LOW PRESSURE OVER SOUTHERN NEW
ENGLAND. SOME OF THE CELLS ARE REACHING UP TO 30-40 KFT WITH
SIGNIFICANT DBZ/S. SUBSEQUENTLY...WHILE GUSTY WINDS OF 20 TO 30
MPH ARE EXPECTED WITH STORMS...COULD SEE ISOLATED STRONGER WHICH
COULD LEAD TO WIND DAMAGE.
OTHERWISE THERE CONTINUES THE THREAT OF HEAVY RAIN /WITH HOURLY
RAINFALL RATES UP TO AROUND 1.5 INCHES/ AND FLASH FLOODING BUT
WITH THE THREAT BECOMING MORE ISOLATED...WILL ALLOW THE FLASH
FLOOD WATCH TO DROP AT 8 PM. HRRR MODEL IS STILL DOING WELL IN
INITIALIZING WITH THE CURRENT CONDITIONS AND FORECASTING
EXPECTATIONS. WILL FOLLOW IT CLOSELY FOR THE EVENING FORECAST.
SOUTHWEST WINDS GUSTING ACROSS THE SOUTHCOAST AND ACROSS THE CAPE
WITH GUSTS UP TO AROUND 20 TO 25 MPH. EXPECT WINDS TO DIMINISH
INTO THE EVENING. CLOUDS IN ABUNDANCE...BUT SOME CLEARING IS
POSSIBLE OVER THE WESTERN ZONES. NEVERTHELESS...ABUNDANCE OF
MOISTURE AND SOUTHERLY WIND FLOW PRESENTS THE THREAT OF SOME
PATCHY FOG...ESPECIALLY ALONG THE COASTS. LOWS DOWN TO THE MID-
TO UPPER-70S BY WEDNESDAY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
COLD FRONT SWEEPS THROUGH THE REGION DURING THE MIDDAY HOURS...THE
PROXIMITY OF WHICH WILL BE ROUGHLY ALONG AND PARALLEL TO THE I-95
CORRIDOR AROUND MIDDAY. MAIN QUESTION IS WHETHER WE WILL SEE SOME
WET WEATHER AHEAD OF THE FRONT.
CONSIDERING AVAILABLE MOISTURE /PWATS AROUND 1.25 INCHES/ COUPLED
WITH SUFFICIENT DEEP-LAYER ASCENT AND UNI-DIRECTIONAL WEST-
SOUTHWEST WIND SHEAR /25-30 KTS/...EXPECT SHOWERS AND POSSIBLE
THUNDERSTORMS AHEAD OF THE COLD FRONT IN AN ENVIRONMENT FAVORABLE
FOR UPDRAFT SUSTAINMENT. SOME QUESTION OF AVAILABLE
INSTABILITY...IMPORTANTLY WHETHER CLOUD DECKS WILL BREAK ALLOWING
FOR SUNSHINE. CONFIDENT IN SEEING SUNSHINE WHICH WILL ALLOW HIGHS
AROUND THE MID 80S. WITH THAT FORECAST GUIDANCE SUPPORTS UP TO
1000 J/KG MUCAPE. CONSIDERING...NOT MUCH CONFIDENCE FOR SEVERE
WEATHER THREATS...BUT BELIEVE THERE WILL BE POCKETS OF HEAVY RAIN
WHICH COULD LEAD TO LOCALIZED FLOODING.
GREATEST CONFIDENCE WITH THE THE 23.0Z ECMWF WHICH INITIALIZED WELL
WITH THE MORNING OUTCOMES. 23.12Z HIGH-RES NAM AND 23.09Z SREF
SUPPORT THE ECMWF. NOTABLY DOWNSTREAM TOWARDS THE EASTERN GREAT
LAKES...JUST THE LOW-LEVEL FORCING AHEAD OF THE LEAD IMPULSE ALOFT
IS GENERATING SHOWER AND THUNDERSTORM ACTIVITY.
WEDNESDAY NIGHT...
HIGH PRESSURE BUILDS SOUTH AND EAST OUT OF CANADA. FEEL THE INTERIOR
WILL BE DRY...BUT SHOWERS WILL BE POSSIBLE ALONG THE SOUTH COAST AS
A MID-LEVEL IMPULSE ROTATING THROUGH THE BROADER TROUGH LIFTS
NORTHEAST ALONG THE OFFSHORE FRONTAL BOUNDARY AND DEEPER AXIS OF
MOISTURE. WITH CLEARING NORTH AND WEST...THIS WILL PERMIT LOWS TO
FALL TO AROUND 50 DEGREES...WHILE REMAINING MILD SOUTH AND EAST
TOWARDS THE CLOUDS AND ANTICIPATED SHOWERY WEATHER. NO EXPECTATION
FOR ANY FLOODING WITH SHOWERS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HEADLINES...
* LESS HUMID WEATHER ARRIVES LATER WED
* NORTHEAST/GRTLKS LONG WAVE TROUGH WILL YIELD SEASONABLE TEMPS
* ACTIVE WEATHER PATTERN WILL RESULT IN SEVERAL BOUTS OF CONVECTION
SYNOPTIC OVERVIEW...
GOOD MODEL AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLES IN
MAINTAINING LONG WAVE TROUGH OVER THE NE/GREAT LKS AND EASTERN
CANADA THIS PERIOD. THIS WILL PRECLUDE EXCESSIVE HEAT/HUMIDITY FROM
ENTERING SOUTHERN NEW ENGLAND AND KEEPING TEMPS AT OR SLIGHTLY
COOLER THAN NORMAL. AS FOR PRECIP...THIS PATTERN WILL FAVOR AN
ACTIVE NORTHERN STREAM JET ACROSS THE NORTHEAST RESULTING IN SEVERAL
BOUTS OF CONVECTION. SO A BREAK FROM THE HEAT AND RELATIVELY DRY
WEATHER PATTERN OF THIS MONTH.
SENSIBLE WEATHER DETAILS...
WED...MAIN PLUME OF MOISTURE MOVES OFFSHORE TONIGHT WITH LEAD SHORT
WAVE TROUGH. HOWEVER SECONDARY/TRAILING SHORT WAVE TROUGH SWEEPS
ACROSS THE AREA WED. THIS FEATURE MAY TOUCH OFF A FEW TSTMS OVER
EASTERN MA AND RI WHERE INSTABILITY LINGERS AND LOW LEVEL
CONVERGENCE IS GREATEST. CAN/T RULE OUT ONE OR TWO STRONG STORMS
WITH CAPES OF 1000-1500J/KG ALONG WITH DEEP LAYER SHEAR OF 25-30 KT.
OTHERWISE BIG IMPROVEMENT FROM TODAY AS DEPARTING SHORT WAVE ADVECTS
MUCH DRIER AND LESS HUMID AIR OVERSPREADS THE REGION LATER WED
AND WED NGT FROM NW TO SE. COULD BE WARMEST DAY OF THE WEEK AS
COOLER AIRMASS LAGS UNTIL WED NGT/THU. THUS HIGHS 85-90 LIKELY.
THU/FRI... FRONT GETS HUNG UP OVER CAPE COD/ISLANDS OR JUST
OFFSHORE. THUS CLOUDS MAY LINGER ACROSS THIS AREA WITH MORE SUNSHINE
INLAND THU. BY FRI WEAK WAVE OF LOW PRES MAY TRAVERSE NE ALONG THE
FRONT AND MAY YIELD A LOW RISK OF RAIN FOR SOUTHEAST MA...WITH LOWER
PROBABILITY OF RAIN INLAND. 00Z NAM AND GFS MORE SUPPRESSED WITH THIS
FRONTAL WAVE. HOWEVER 00Z ECMWF MORE ROBUST AND BRINGS QPF ACROSS
MUCH OF SOUTHERN NEW ENGLAND. 00Z GEFS IS SOMEWHERE IN BETWEEN WITH
30-50% PROBS OF RAIN FRI/FRI NGT ACROSS SOUTHEAST MA. GIVEN
UNCERTAINTY WILL HANDLE THIS WITH CHANCE POPS CAPE COD AND
ISLANDS...SLIGHT CHANCE ELSEWHERE.
COULD BE A BIT BREEZY AND COOL THU/FRI ACROSS EASTERN MA WITH NE
WINDS AS FRONT LURKS JUST OFFSHORE AND HIGH PRES BUILDS INTO THE ST
LWRNC RVR VLY.
SAT/SUN/MON...DRY WEATHER APPEARS TO LINGER INTO SAT ALONG WITH
SEASONABLE TEMPS. HOWEVER NEXT TROUGH ARRIVES SUN/MON BRINGING THE
RISK OF ANOTHER ROUND OF SHOWERS/TSTMS.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
18Z UPDATE...
BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.
ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.
A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.
OUTLOOK...THURSDAY THROUGH SATURDAY...
THU AND FRI...LOW CONFIDENCE REGARDING AREAL COVERAGE OF POSSIBLE
RAIN SHIELD AND ASSOCIATED MVFR CONDITIONS. ENE WINDS. RAIN MAY
IMPACT SOUTHEAST MA.
SAT...MODERATE CONFIDENCE. VFR. SCT PM SHOWERS/TSTMS MAINLY IN
WESTERN NEW ENGLAND.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
SHOWERS AND THUNDERSTORMS WILL IMPACT THE NEAR-COASTAL WATERS INTO
THE EARLY EVENING HOURS...GRADUALLY DISSIPATING INTO THE OUTER
WATERS. HEAVY RAIN WITH REDUCED VISIBILITIES ALONG WITH FREQUENT
LIGHTNING SHOULD BE ANTICIPATED WITH THESE STORMS. GUSTY WINDS
ANTICIPATED WHICH COULD EXCEED GALE FORCE.
OTHERWISE WHILE SOUTHWEST WINDS ARE GUSTING AROUND 20 KTS ACROSS
THE CAPE PRESENTLY...FEEL SUCH WINDS WILL DIMINISH THROUGH THE
EVENING HOURS. WILL HOLD WINDS AND SEAS BELOW SMALL CRAFT ADVISORY
THRESHOLDS. STILL CONCERNS FOR PATCHY FOG ALONG THE SOUTH COAST
WITH THE POTENTIAL FOR VISIBILITIES DOWN TO A QUARTER MILE OR
LESS...BUT HAVE LOW CONFIDENCE AT THIS TIME.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
THURSDAY AND FRIDAY...LOW CONFIDENCE ON POTENTIAL RAIN SHIELD AND
ASSOCIATED VSBYS. ENE WINDS WITH FRONTAL BOUNDARY JUST OFFSHORE. LOW
PRES MAY RIDE ALONG THIS FRONT WITH ITS RAIN SHIELD POSSIBLY
IMPACTING THE SOUTHERN NEW ENGLAND WATERS.
SATURDAY...MODERATE CONFIDENCE.
S/SE FLOW GETS UNDERWAY AND SHOULD VEER TO SW LATE AS COLD FRONT
PUSHES INTO UPSTATE NY. WINDS AND SEAS SHOULD REMAIN BELOW SCA.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...WTB
AVIATION...WTB/SIPPRELL
MARINE...WTB/SIPPRELL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
146 PM EDT TUE JUL 23 2013
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BECOME MORE NUMEROUS INTO THE
AFTERNOON HOURS AS AN AREA OF LOW PRESSURE WITH AN ATTENDANT WARM
FRONT SLOWLY LIFT ACROSS THE REGION. A COLD FRONT WILL SWEEP
ACROSS THE REGION WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID
WEATHER THURSDAY AND FRIDAY. WARMER AIR RETURNS NEXT WEEKEND
BEFORE A COLD FRONT BRINGS SCATTERED SHOWERS/THUNDERSTORMS
SUNDAY...POSSIBLY LINGERING INTO MONDAY
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
*** FLASH FLOOD WATCH IS IN EFFECT TILL THIS EVENING***
2 PM UPDATE...
CLEARING PROCEEDED DURING THE LATE MORNING INTO MIDDAY HOURS
ALLOWING FOR BOUNDARY LAYER DESTABILIZATION. SUBSEQUENTLY...THE
RICH MOISTURE PROFILE IS EASILY LIFTING WITH AMBIENT SUNSHINE IN
AN ENVIRONMENT OF FAVORABLE SHEAR CONSEQUENTIALLY RESULTING IN
BANDS OF SHOWERS AND THUNDERSTORMS CONTAINING HEAVY RAIN.
DEEP-LAYER LIFT COMBINED WITH THE FAVORABLE SHEAR SHOULD ALLOW
UPDRAFTS TO SUSTAIN INTO THE EARLY EVENING HOURS...THUS THE
THUNDERSTORM LIKELIHOOD WILL CONTINUE WITH THE THREAT OF HEAVY
RAIN AND FLASH FLOODING. HRRR MODELS THE PRESENT ACTIVITY AND
ANTICIPATED OUTCOMES INTO EARLY EVENING WELL. HOURLY RAINFALL
AMOUNTS OF UP TO 2 INCHES ARE POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
TONIGHT...
MID-LEVEL DRYING WILL PUSH INTO THE REGION AS TROUGH AXIS MOVES
ACROSS THE REGION. COLD FRONT IS ALSO PROGGED TO MOVE ACROSS THE
REGION THIS EVENING AND INTO THE OVERNIGHT HOURS. BELIEVE THAT
PRECIP WILL SLOWLY COME TO AN END FROM WEST TO EAST INTO THE
OVERNIGHT HOURS. VERY LITTLE RELIEF IS EXPECTED AS MOISTURE STILL
LINGER ACROSS THE REGION. EXPECT TEMPS TO DROP ONLY INTO THE MID 60S
TO LOW 70S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HEADLINES...
* LESS HUMID WEATHER ARRIVES LATER WED
* NORTHEAST/GRTLKS LONG WAVE TROUGH WILL YIELD SEASONABLE TEMPS
* ACTIVE WEATHER PATTERN WILL RESULT IN SEVERAL BOUTS OF CONVECTION
SYNOPTIC OVERVIEW...
GOOD MODEL AGREEMENT AMONG THE GFS AND ECMWF ENSEMBLES IN
MAINTAINING LONG WAVE TROUGH OVER THE NE/GREAT LKS AND EASTERN
CANADA THIS PERIOD. THIS WILL PRECLUDE EXCESSIVE HEAT/HUMIDITY FROM
ENTERING SOUTHERN NEW ENGLAND AND KEEPING TEMPS AT OR SLIGHTLY
COOLER THAN NORMAL. AS FOR PRECIP...THIS PATTERN WILL FAVOR AN
ACTIVE NORTHERN STREAM JET ACROSS THE NORTHEAST RESULTING IN SEVERAL
BOUTS OF CONVECTION. SO A BREAK FROM THE HEAT AND RELATIVELY DRY
WEATHER PATTERN OF THIS MONTH.
SENSIBLE WEATHER DETAILS...
WED...MAIN PLUME OF MOISTURE MOVES OFFSHORE TONIGHT WITH LEAD SHORT
WAVE TROUGH. HOWEVER SECONDARY/TRAILING SHORT WAVE TROUGH SWEEPS
ACROSS THE AREA WED. THIS FEATURE MAY TOUCH OFF A FEW TSTMS OVER
EASTERN MA AND RI WHERE INSTABILITY LINGERS AND LOW LEVEL
CONVERGENCE IS GREATEST. CAN/T RULE OUT ONE OR TWO STRONG STORMS
WITH CAPES OF 1000-1500J/KG ALONG WITH DEEP LAYER SHEAR OF 25-30 KT.
OTHERWISE BIG IMPROVEMENT FROM TODAY AS DEPARTING SHORT WAVE ADVECTS
MUCH DRIER AND LESS HUMID AIR OVERSPREADS THE REGION LATER WED
AND WED NGT FROM NW TO SE. COULD BE WARMEST DAY OF THE WEEK AS
COOLER AIRMASS LAGS UNTIL WED NGT/THU. THUS HIGHS 85-90 LIKELY.
THU/FRI... FRONT GETS HUNG UP OVER CAPE COD/ISLANDS OR JUST
OFFSHORE. THUS CLOUDS MAY LINGER ACROSS THIS AREA WITH MORE SUNSHINE
INLAND THU. BY FRI WEAK WAVE OF LOW PRES MAY TRAVERSE NE ALONG THE
FRONT AND MAY YIELD A LOW RISK OF RAIN FOR SOUTHEAST MA...WITH LOWER
PROBABILITY OF RAIN INLAND. 00Z NAM AND GFS MORE SUPPRESSED WITH THIS
FRONTAL WAVE. HOWEVER 00Z ECMWF MORE ROBUST AND BRINGS QPF ACROSS
MUCH OF SOUTHERN NEW ENGLAND. 00Z GEFS IS SOMEWHERE IN BETWEEN WITH
30-50% PROBS OF RAIN FRI/FRI NGT ACROSS SOUTHEAST MA. GIVEN
UNCERTAINTY WILL HANDLE THIS WITH CHANCE POPS CAPE COD AND
ISLANDS...SLIGHT CHANCE ELSEWHERE.
COULD BE A BIT BREEZY AND COOL THU/FRI ACROSS EASTERN MA WITH NE
WINDS AS FRONT LURKS JUST OFFSHORE AND HIGH PRES BUILDS INTO THE ST
LWRNC RVR VLY.
SAT/SUN/MON...DRY WEATHER APPEARS TO LINGER INTO SAT ALONG WITH
SEASONABLE TEMPS. HOWEVER NEXT TROUGH ARRIVES SUN/MON BRINGING THE
RISK OF ANOTHER ROUND OF SHOWERS/TSTMS.
&&
.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 /INTO WEDNESDAY NIGHT/...MODERATE CONFIDENCE.
18Z UPDATE...
BANDS OF SHRA/TSRA DEVELOPING ACROSS SOUTHERN NEW ENGLAND WILL
PREVAIL INTO THE EARLY EVENING HOURS. HAVE GONE -RA VCTS WITH
EXPECTATION OF THREATS...BUT WITH ANY IMPACTS...ANTICIPATING
SOUTHWESTERLY WINDS AROUND 10G20KT ALONG WITH IFR VSBYS.
ACTIVITY SHOULD DISSIPATE TOWARDS THE EARLY EVENING HOURS BECOMING
QUIET FOR THE MOST PART OVERNIGHT. OVERNIGHT VSBYS A CHALLENGE
WITH EXPECTED WEST-SOUTHWEST FLOW. WILL PREVAIL MVFR. NEED TO
MONITOR FOR EITHER THE DEVELOPMENT OF IFR CIGS AND/OR VSBYS. WITH
FLOW PREVAILING 10 KTS...HAVE GREATER CONFIDENCE WITH LOW CIGS.
A COLD FRONT WILL SWEEP ACROSS THE TERMINALS WEDNESDAY ALONG AND
AHEAD OF WHICH SHRA/TSRA WILL BE POSSIBLE...BUT ISOLATED TO WIDELY
SCATTERED. PERHAPS TEMPO MVFR IMPACTS. ACTIVITY DIMINISHING INTO
EVENING AS THE FRONT MOVES OFFSHORE. COULD SEE SOME LOCALIZED
IMPACTS ALONG THE SOUTH SHORE DOWN TO MVFR WITH -SHRA.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. TSRA CONSTANTLY
DEVELOPING WEST WHICH WILL REQUIRE MULTIPLE AFTERNOON UPDATES.
AGAIN...STORMS PRODUCING TEMPO 10G20KT WITH MVFR/IFR IMPACTS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LINE OF SHRA/TSRA
DEVELOPING NORTH AND WEST. HAVE TIMED INTO TAF AS BEST AS
POSSIBLE. TEMPO MVFR/IFR IMPACTS WITH STORMS ANTICIPATED.
OUTLOOK...THURSDAY THROUGH SATURDAY...
THU AND FRI...LOW CONFIDENCE REGARDING AREAL COVERAGE OF POSSIBLE
RAIN SHIELD AND ASSOCIATED MVFR CONDITIONS. ENE WINDS. RAIN MAY
IMPACT SOUTHEAST MA.
SAT...MODERATE CONFIDENCE. VFR. SCT PM SHOWERS/TSTMS MAINLY IN
WESTERN NEW ENGLAND.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY THROUGH TONIGHT...MODERATE CONFIDENCE.
WINDS/SEAS WILL REMAIN BELOW SCA THRESHOLDS. HAVE UNDERCUT WAVE
GUIDANCE FOR TODAY AS MODELS HAVE A HARD TIME WITH SOUTHERN SWELL.
LOW CONFIDENCE ON SCA SEAS DEVELOPING LATE THIS AFTERNOON. HOWEVER
CONFIDENCE INCREASES TONIGHT ACROSS THE SOUTHERN ATLANTIC WATERS
WITH PERSISTENT LONG SOUTHWEST FETCH AHEAD OF AN APPROACHING COLD
FRONT. ITS UNCERTAIN HOW HIGH SEAS WILL GET WITH AN INVERSION IN
PLACE...SO WITH LOW CONFIDENCE HAVE HOLD OFF ON ISSUING A SCA AT
THIS TIME. OTHER CONCERN WILL BE FOR AREAS OF FOG WHICH MAY BE
LOCALLY DENSE ACROSS SOME OF THE WATERS DURING THE OVERNIGHT
TONIGHT AND MORNING HOURS ON WED.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY...HIGH CONFIDENCE.
COLD FRONT PUSHES OFFSHORE DURING AFTERNOON/EVENING AND MAY
RESULT IN AN ISOLATED SHOWER/STORM NEAR SHORE. FRONT WILL BRING
GRADUAL WIND SHIFT TO W BUT WINDS/SEAS REMAIN BELOW SCA.
THURSDAY AND FRIDAY...LOW CONFIDENCE ON POTENTIAL RAIN SHIELD AND
ASSOCIATED VSBYS. ENE WINDS WITH FRONTAL BOUNDARY JUST OFFSHORE. LOW
PRES MAY RIDE ALONG THIS FRONT WITH ITS RAIN SHIELD POSSIBLY
IMPACTING THE SOUTHERN NEW ENGLAND WATERS.
SATURDAY...MODERATE CONFIDENCE.
S/SE FLOW GETS UNDERWAY AND SHOULD VEER TO SW LATE AS COLD FRONT
PUSHES INTO UPSTATE NY. WINDS AND SEAS SHOULD REMAIN BELOW SCA.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES WILL BE ABNORMALLY HIGH DURING THE HIGH TIDE
CYCLE NEAR MIDNIGHT TONIGHT. BOS TIDE IS AGAIN 12.1 FT. HOWEVER
WITH OFFSHORE FLOW...BELIEVE THE THREAT FOR COASTAL FLOODING WILL
BE LOW. THERE MAY BE POCKETS OF SPLASHOVER...BUT WITH LOW
CONFIDENCE HAVE HOLD OFF ON ANY ISSUING ANY STATEMENT AT THIS
TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ002>021-
026.
NH...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-
015.
RI...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...SIPPRELL
SHORT TERM...DUNTEN
LONG TERM...NOCERA
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
933 PM EDT WED JUL 24 2013
.UPDATE...
AN UPPER LEVEL TROUGH OVER THE SOUTHEAST WILL KEEP WESTERLY WINDS
IN PLACE FOR THE FORECAST AREA OVERNIGHT. CURRENTLY HAVE A FEW
SHOWERS MOVING IN OFF THE WARM GULF WATERS AND THIS TREND IS
EXPECTED TO CONTINUE THROUGH THE EARLY MORNING HOURS. WILL KEEP
THE BEST RAIN CHANCES AGAIN FOR THE NORTHERN WATERS AND FROM
AROUND TAMPA BAY NORTHWARD. LOCAL WRF AND HRRR MODELS SHOW PRECIP
AROUND THE TAMPA BAY AREA AROUND 10-11Z AND THIS SEEMS REASONABLE
GIVEN THE CURRENT ATMOSPHERIC SETUP. THE CURRENT POPS ARE ON
TRACK WITH THIS AND THE TEMPERATURES LOOK GOOD AS WELL...SO NO
UPDATES ARE PLANNED TONIGHT.
&&
.AVIATION...
GENERALLY VFR CONDITIONS EXPECTED...BUT CAN/T RULE OUT A SHRA
DRIFTING ONSHORE FROM KSRQ NORTHWARD THIS EVENING. BETTER CHANCES
FOR SHRA LATER TONIGHT 08/09Z AND WILL INCLUDE VCSH TO ACCOUNT
FOR THIS. SOUTH OF KSRQ...VFR CONDITIONS ARE EXPECTED THROUGH THE
OVERNIGHT HOURS. BEST CHANCE OF TSRA WILL BE EAST OF ALL TERMINALS
THURSDAY...SO WILL NOT MENTION VCTS AT ANY OF THE TAF SITES. HAVE
INCLUDED VCSH AT MOST PROBABLE TIMES AT ALL TAF SITES...BUT HIGHEST
RAIN CHANCES WILL CONTINUE TO BE FROM KSRQ NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 89 79 91 / 20 30 20 20
FMY 78 91 78 91 / 20 20 10 20
GIF 75 91 75 93 / 20 40 10 40
SRQ 80 89 79 89 / 20 20 10 20
BKV 74 90 73 93 / 20 30 20 20
SPG 81 88 82 90 / 20 30 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 6 AM EDT THURSDAY FOR HILLSBOROUGH-
MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
UPDATE...05/CARLISLE
AVIATION...21/JELSEMA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
907 PM EDT WED JUL 24 2013
.DISCUSSION...
CURRENTLY INTO EARLY THU...TROUGH ALOFT OVER THE EASTERN CONUS IS
PROVIDING A DEEP LAYER OF WESTERLY FLOW. A FEW SHOWERS HAVE BEEN
MOVING ACROSS NORTHERN SECTIONS BUT THEY ARE DIMINISHING SO EXPECT
THE WEATHER TO BE QUIET INTO THE OVERNIGHT HOURS. HOWEVER THE LATEST
RAP AND GFS MODELS DO SHOW WEAK IMPULSES ALOFT MOVING TOWARDS THE
AREA. THE LOCAL WRF AND RAP MODELS BRING A BIG AREA OF PRECIP INTO
OUR NORTHERN SECTIONS BY 08-10Z. THIS LOOKS OVERDONE...BUT WILL
INCLUDE A SLIGHT CHANCE OF SHOWERS IN THE NORTH HALF OVERNIGHT.
EXPECT CLUSTER OF CONVECTION NEAR APALACHEE BAY THIS EVENING TO SEND
A BOUNDARY TOWARDS OUR NORTHERN SECTIONS DURING THE OVERNIGHT. WITH
AN IMPULSE ALOFT MOVING ACROSS EARLY THU...THERE SHOULD AGAIN BE AN
EARLY START TO SHOWERS/STORMS IN OUR NORTHERN SECTIONS.
&&
.AVIATION...A FEW SHOWERS MOVING ACROSS THE PENINSULA NORTHWARD FROM
KISM-KMCO BUT HAVE BEEN DIMINISHINGS SO EXPECT STABILIZATION AND VFR
CONDITIONS INTO LATE NIGHT. THE RAP AND LOCAL WRF MODELS ARE SHOWING
A BIG AREA OF PRECIP MOVING ACROSS THE TERMINALS FROM KISM-KMCO-KTIX
NORTHWARD AFT ABOUT 08Z. THIS LOOKS OVERDONE BUT THERE SHOULD BE A
FEW GULF SHOWERS PUSHING INLAND. HAVE NOT INCLUDED THEM IN THE
TAFS YET. EXPECT ANOTHER EARLY START TO SHOWER CHANCES AGAIN
THU...POSSIBLY A LITTLE PAST SUNRISE KLEE-KDAB AND BY LATE MORNING
KISM-KMCO-KTIX WITH INCREASING CHANCES FOR STORMS TOWARDS MIDDAY.
&&
.MARINE...TONIGHT-THU...LARGE TROUGH WILL CONTINUE TO ENCOMPASS THE
EASTERN SEABOARD WHILE SURFACE RIDGING REMAINS SOUTH OF THE LOCAL
COASTAL WATERS. WEST/SOUTHWEST WINDS TO REMAIN ELEVATED BETWEEN
10 AND 15 KTS. SEAS 1-2 FT NEAR SHORE AND 2-3 FT OFFSHORE...THOUGH 4
FT SEAS ARE POSSIBLE WELL OFFSHORE. STORMS MOVING OFFSHORE REMAIN A
THREAT AGAIN BY ABOUT MIDDAY THU FROM THE CAPE NORTH AND THROUGH THE
AFTERNOON SOUTH OF THE CAPE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
RADAR/IMPACT WEATHER...MOSES
AREA FORECAST DISCUSSION
NWS MIAMI FL
215 PM EDT TUE JUL 23 2013
.SHORT TERM (TONIGHT-THURSDAY NIGHT)...
A STRONG SUBTROPICAL DEEP LAYER RIDGE CURRENTLY LOCATED ACROSS SOUTH
FLORIDA AND THIS SUPPRESSING THE CONVECTION. THE 12Z MFL SOUNDING
SHOWED THE LOWEST LAYERS OF THE ATMOSPHERE HAD DESTABILIZED
SUBSTANTIALLY FROM 24 HOURS AGO SO CU DEVELOPED EARLIER WHICH HAS
LEAD TO EARLIER SHOWER DEVELOPMENT TOO ALONG WITH A FEW
THUNDERSTORMS. A SEA BREEZE LINE OF CONVECTION DEVELOPED RIGHT ALONG
THE COAST OF SOUTHERN BROWARD AND IT APPEARS THAT SOME ADDITIONAL
CONVERGENCE SET UP OTHER THAN JUST THE SEA BREEZE. LOOKING AT
VISIBLE SATELLITE IMAGES REVEALS A CONVERGENT BOUNDARY ASSOCIATED
WITH AN OUTFLOW/LAND BREEZE OFF THE EAST COAST WITH THIS BAND
EXTENDING WELL OUT INTO THE ATLANTIC. OUTSIDE OF THIS, THERE IS ALSO
A MID LEVEL TROUGH THAT IS DEEPENING OVER THE EASTERN STATES WITH
FORECAST SOUNDINGS INDICATING THE RIDGE WOULD BEGIN TO SHIFT SOUTH
THROUGH THIS AFTERNOON AND THIS APPEARS TO BE OCCURRING WITH LOW
TOPPED CONVECTION ALREADY DRIFTING TO THE EAST. HOWEVER, AS THE
DAY PROGRESSES AND DIURNAL HEATING CAN DESTABILIZE A DEEPER
PORTION OF THE ATMOSPHERE THE STEERING FLOW IS STILL VERY WEAK SO
STORM MOTION IS STILL EXPECTED TO BE SLOW AND POSSIBLY ERRATIC
ALTHOUGH THERE COULD BE A DRIFT TOWARDS THE EAST. SOME OF THE
SHORT RANGE HIGH RESOLUTION MODELS SUCH AS THE HRRR ARE SHOWING
MORE ROBUST CONVECTION FORMING OVER THE INTERIOR AROUND 17-18Z
(ALTHOUGH THIS NOT OCCURRING AS OF 1815Z) AND THEN SLOWLY MOVING
TOWARDS THE EAST BUT THEN AS THE HEATING CYCLE IS CUT OFF WITH A
LOWER SUN ANGLE, THE CONVECTION NEVER MAKES IT QUITE TO THE EAST
COAST AND THIS APPEARS REASONABLE GIVEN THE ABOVE REASONING.
THE RIDGE WILL CONTINUE TO SHIFT SOUTH TONIGHT AND BE OVER THE
FLORIDA STRAITS INCLUDING THE KEYS AS THE TROUGH CONTINUES TO
DEEPEN. THIS WILL ALLOW FOR A DEEP WESTERLY FLOW TO BECOME
ESTABLISHED ON WEDNESDAY AND THURSDAY WITH FORECASTING SOUNDINGS
SHOWING A STORM MOTION OF AROUND 5-7 MPH ON WEDNESDAY AND NEAR 10
MPH ON THURSDAY. NONE OF THE GLOBAL MODELS HOWEVER INDICATE AN
ABUNDANCE OF DEEP LAYER AVAILABLE MOISTURE NOR INSTABILITY SO
WIDESPREAD CONVECTION AT THIS TIME IS NOT EXPECTED. THE NAM, GFS AND
ECMWF ALL SHOW PWAT IN THIS TIME FRAME TO BE 1.5-1.7 INCHES WHICH IS
CLOSE TO OR SLIGHTLY BELOW THE AVERAGE FOR MID TO LATE JULY. BUT THE
SCATTERED STORMS THAT DO DEVELOP IN THIS PATTERN WILL FAVOR THE
INTERIOR AND EAST COAST METRO AREAS.
.LONG TERM (FRIDAY-TUESDAY)...
NOT MUCH CHANGE IS FORESEEN LOOKING TOWARDS THE END OF THE WEEK INTO
SATURDAY AS THE MAIN MID LEVEL TROUGH WILL REMAIN IN PLACE ACROSS
THE EASTERN STATES. THIS WILL MAINTAIN THE DEEP WESTERLY FLOW ACROSS
SOUTH FLORIDA WITH A FORECAST PWAT REMAINING NEAR NORMAL VALUES.
NONE OF THE MODELS SHOW ANY KIND OF MOISTURE INFLUX SO AT THIS TIME,
BY LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK SCATTERED
THUNDERSTORMS ARE EXPECTED WITH THE PATTERN AGAIN REVERTING TO
MOSTLY INTERIOR AWAY FROM BOTH COASTS.
&&
.AVIATION...
DIFFUSE AXIS OF CONVERGENCE ALONG THE EAST COAST IS ACTING AS A
FOCUS FOR SHRA/TSRA DEVELOPMENT EARLY THIS AFTERNOON AND IS MAINLY
AFFECTING KMIA NORTHWARD TO KFLL. ACTIVITY IS BEGINNING TO WEAKEN AS
OUTFLOW RETREATS TO THE WEST. LATEST HRRR DEVELOPS ADDITIONAL
ACTIVITY LATER THIS AFTERNOON ACROSS THE INTERIOR AND PROPAGATES IT
EASTWARD TOWARD THE ATLANTIC COAST. KEPT VCSH MENTION IN AT ALL EAST
COAST SITES THROUGH 02Z WITH LIGHT SOUTHERLY FLOW BECOMING MORE
SOUTHWESTERLY OVERNIGHT.
&&
.MARINE...
LIGHT SOUTH TO SOUTHEAST WIND WILL VEER TO A SOUTH TO SOUTHWEST
DIRECTION ON WEDNESDAY AND CONTINUE THROUGH FRIDAY WITH SEAS LESS
THAN 4 FEET AS THE RIDGE SHIFTS SOUTH OF THE AREA. THE RIDGE WILL
THEN MOVE BACK NORTH OVER THE WEEKEND WITH A RETURN TO A LIGHT
SOUTHEAST WIND.
&&
.FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 90 75 91 / 20 40 20 40
FORT LAUDERDALE 77 90 77 91 / 20 40 20 30
MIAMI 77 90 76 91 / - 30 20 30
NAPLES 76 88 74 89 / - 20 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
250 PM EDT TUE JUL 23 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPPER TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELATIVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DUE TO LIMITED
COVERAGE...LOWER PW...AND FASTER CELL MOVEMENT...THINK LOCALLY
HEAVY RAIN/FLOODING THREAT MINIMAL. HOWEVER...DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH THURSDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR
REMAINING IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY
CONVECTIVE ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE
THIS EVENING WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH
TONIGHT.
A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO INCLUDE
A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS. GIVEN MODERATE
INSTABILITY AND SMALL SCALE BOUNDARY INTERSECTIONS...A FEW STORMS
COULD BE SEVERE. WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND
THUNDERSTORMS WILL CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES
THROUGH THE AREA OVERNIGHT.
THE FRONT IS FORECAST TO MOVE SOUTH OF THE AREA THURSDAY...BUT GIVEN
ITS PROXIMITY COMBINED WITH AND UNSTABLE AIR MASS AND PERHAPS A
WEAK SHORT WAVE MOVING THOUGH THE LONG WAVE TROUGH...THE THREAT OF
CONVECTION CONTINUES.
WILL SEE HIGHS IN THE UPPER 80S TO LOWER 90S WITH LOWS IN THE
LOW/MID 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MEAN UPPER TROUGH WILL REMAIN ACROSS THE EASTERN CONUS THROUGH
THE WEEKEND...THEN BEGIN TO LIFT OUT MONDAY. MODELS INDICATE A
SERIES OF SHORT WAVES CROSSING THE AREA. HOWEVER...THEY DIFFER ON
THE TIMING OF SIGNIFICANT SHORT WAVES WHICH WOULD GENERATE
CONVECTION. A FRONTAL BOUNDARY WILL BE STALLED ACROSS THE GULF COAST
STATES FRIDAY THROUGH SUNDAY...THEN BEGIN TO LIFT NORTHWARD TOWARD
THE AREA EARLY NEXT WEEK. OUR ACTIVE WEATHER PATTERN WILL PERSIST.
SLIGHT CHANCE POPS FRIDAY INCREASE TO HIGH CHANCE OVER THE WEEKEND
INTO MONDAY.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR
DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER MID LEVEL AIR ENTERING
THE REGION...WITH ONLY A SLIGHT CHANCE OF A LATE AFTERNOON/EVENING
THUNDERSTORM. HOWEVER...AN UPPER DISTURBANCE AND BETTER MOISTURE TO
OUR WEST MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND
THIS EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION
IN THE TAFS AT THIS TIME. WILL MONITOR RADAR TRENDS AND AMEND IF
NECESSARY. GUIDANCE INDICATING POTENTIAL FOR MVFR VSBYS IN FOG LATE
TONIGHT/EARLY WED. THIS WILL DEPEND ON EXTENT OF ANY LINGERING
MID/UPPER LEVEL DEBRIS CLOUDINESS THAT MAY STREAM IN FROM THE WEST.
SCATTERED CONVECTION EXPECTED WED...AFT 18Z.
EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
127 PM EDT TUE JUL 23 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPEPR TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELAITVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DUE TO LIMITED
COVERAGE...LOWER PW...AND FASTER CELL MOVEMENT...THINK LOCALLY
HEAVY RAIN/FLOODING THREAT MINIMAL. HOWEVER...DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR REMAINING
IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY CONVECTIVE
ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE THIS EVENING
WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH TONIGHT. ON
WEDNESDAY MOISTURE WILL BEGIN RETURNING TO THE COLUMN...HOWEVER
THIS IS NOT EXPECTED UNTIL LATE IN THE AFTERNOON. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO
INCLUDE A LOW CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS.
WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES THROUGH THE AREA
OVERNIGHT. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE
LOWER 70S FOR OVERNIGHT LOWS WITH HIGH TEMPERATURES WEDNESDAY
AFTERNOON IN THE LOWER TO MIDDLE 90S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH FRIDAY WITH DIFFERENCES
INCREASING THROUGH THE WEEKEND. UPPER LEVEL TROUGH WILL REMAIN
OVER THE REGION THROUGH THE WEEKEND BEFORE LIFTING OUT ON MONDAY
WHICH WILL KEEP THE ACTIVE WEATHER PATTERN OVER THE REGION. MODELS
INDICATE A SERIES OF SHORT WAVE CROSSING THE AREA THROUGH THE LONG
TERM...HOWEVER DIFFER ON THE TIMING OF SIGNIFICANT SHORT WAVES
WHICH WOULD GENERATE CONVECTION. AS SUCH CONFIDENCE IN THE LONG
TERM IS LOWER THAN DESIRED AND HAVE REMAINED WITH MAINLY DIURNAL
CHANCES OF SHOWERS AND THUNDERSTORMS INTO EARLY NEXT WEEK.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL
FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER MID LEVEL AIR ENTERING
THE REGION...WITH ONLY A SLIGHT CHANCE OF A LATE AFTERNOON/EVENING
THUNDERSTORM. HOWEVER...AN UPPER DISTURBANCE AND BETTER MOISTURE TO
OUR WEST MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND
THIS EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION
IN THE TAFS AT THIS TIME. WILL MONITOR RADAR TRENDS AND AMEND IF
NECESSARY. GUIDANCE INDICATING POTENTIAL FOR MVFR VSBYS IN FOG LATE
TONIGHT/EARLY WED. THIS WILL DEPEND ON EXTENT OF ANY LINGERING
MID/UPPER LEVEL DEBRIS CLOUDINESS THAT MAY STREAM IN FROM THE WEST.
SCATTERED CONVECTION EXPECTED WED...AFT 18Z.
EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1037 AM EDT TUE JUL 23 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH WILL CONTINUE DEEPENING AS IT MOVES OVER THE
EASTERN US THIS AFTERNOON. THE TROUGH WILL REMAIN OVER THE
FORECAST THROUGH THE WEEKEND RESULTING IN AN ACTIVE WEATHER
PATTERN.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPEPR TROUGH OVER THE E CONUS. WEAK SURFACE TROUGH STRETCHES DOWN
THE EASTERN SEABOARD. AN UPPER DISTURBANCE WILL PUSH TO OUR
EAST...WITH SOME DRIER MID LEVEL AIR MOVING IN. HIGHEST PW VALUES
HAVE PUSHED TO NEAR THE COAST AND OFFSHORE AND ALSO TO OUR
WEST...WITH DRIER AIR AND PW VALUES 1.5 INCHES OR LESS PUSHING ESE
INTO MOST OF OUR FA TODAY. FORECAST SOUNDINGS INDICATE HIGH LFCS.
LATEST HIGH RESOLUTION MODELS KEEP CONVECTIVE ACTIVITY TO A
RELAITVE MINIMUM TODAY. LATEST HRRR WEAKENS THE CURRENT BATCH OF
CONVECTION THAT IS ACROSS N ALA/NW GA. LATE TODAY INTO THIS
EVENING...ANOTHER UPPER DISTURBANCE TO PUSH SE TOWARDS GA TODAY
WITH BETTER MOISTURE AVAILABLE IN THAT AREA COULD PROMOTE SOME
CONVECTION WHICH COULD PUSH TOWARDS THE CSRA. THINK SLIGHT CHANCE
POPS IN ORDER FOR MOST OF THE FA...BUT UPPED THEM SLIGHTLY TO LOW
CHANCE CSRA LATE TODAY AND THIS EVENING. DCAPE VALUES ARE
PROJECTED TO INCREASE TO 1000 TO 1300 J/KG CSRA...SO ANY STRONGER
STORMS THAT FORM COULD PRODUCE A WIND THREAT. ALSO MADE SLIGHT
ADJUSTMENTS TO TEMPS...DEWPOINTS AND WINDS TODAY BASED ON CURRENT
TRENDS AND LATEST GUIDANCE. GUIDANCE BRINGS DEWPOINTS DOWN INTO
THE UPPER 60S THIS AFTERNOON FOR MUCH OF THE FA...THOUGH RECENT
RAINS AND HIGH SOIL MOISTURE COULD KEEP THEM FROM GETTING DOWN
QUITE THAT LOW.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SHORT WAVE TROUGH WILL MOVE FURTHER OFFSHORE WITH DRY AIR REMAINING
IN THE MID AND UPPER LEVELS OVERNIGHT. EXPECT ANY CONVECTIVE
ACTIVITY WHICH DEVELOPS THIS AFTERNOON TO DISSIPATE THIS EVENING
WITH THE LOSS OF HEATING AND A DRY FORECAST THROUGH TONIGHT. ON
WEDNESDAY MOISTURE WILL BEGIN RETURNING TO THE COLUMN...HOWEVER
THIS IS NOT EXPECTED UNTIL LATE IN THE AFTERNOON. WITH THE UPPER
LEVEL TROUGH ALSO OVER THE REGION AND A SERIES OF WEAK SHORT WAVES
ROTATING THROUGH THE AXIS THERE WILL BE ENOUGH POTENTIAL TO
INCLUDE A LOW CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS.
WEDNESDAY NIGHT THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE AS A FAIRLY VIGOROUS SHORT WAVE MOVES THROUGH THE AREA
OVERNIGHT. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE
LOWER 70S FOR OVERNIGHT LOWS WITH HIGH TEMPERATURES WEDNESDAY
AFTERNOON IN THE LOWER TO MIDDLE 90S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT THROUGH FRIDAY WITH DIFFERENCES
INCREASING THROUGH THE WEEKEND. UPPER LEVEL TROUGH WILL REMAIN
OVER THE REGION THROUGH THE WEEKEND BEFORE LIFTING OUT ON MONDAY
WHICH WILL KEEP THE ACTIVE WEATHER PATTERN OVER THE REGION. MODELS
INDICATE A SERIES OF SHORT WAVE CROSSING THE AREA THROUGH THE LONG
TERM...HOWEVER DIFFER ON THE TIMING OF SIGNIFICANT SHORT WAVES
WHICH WOULD GENERATE CONVECTION. AS SUCH CONFIDENCE IN THE LONG
TERM IS LOWER THAN DESIRED AND HAVE REMAINED WITH MAINLY DIURNAL
CHANCES OF SHOWERS AND THUNDERSTORMS INTO EARLY NEXT WEEK.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL
FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS CURRENTLY STILL HANGING ON ACROSS THE SOUTHERN
FA...INCLUDING OGB. EXPECT VFR CONDITIONS THIS AFTERNOON. DRIER
MID LEVEL AIR ENTERING THE REGION...WITH GENERALLY ONLY A SLIGHT
CHANCE OF AN AFTERNOON THUNDERSTORM...THOUGH AN UPPER DISTURBANCE
MAY PROVIDE A BETTER CHANCE OF TS AT AGS/DNL LATE TODAY AND THIS
EVENING...BUT THUNDERSTORM CHANCES TOO LOW TO INCLUDE MENTION IN
THE TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
833 PM CDT WED JUL 24 2013
.DISCUSSION...
ISSUED 833 PM CDT WED JUL 24 2013
HIGH PRESSURE...RIDGING OVER THE WESTERN GREAT LAKES INTO
NEBRASKA...HAS STIFLED THE DIURNAL CUMULUS THAT WAS PROMINENT
OVER THE WESTERN HALF OF THE CWA DURING THE LATE AFTERNOON.
REGIONAL SATELLITE IMAGERY SHOWING A LARGE AREA OF HIGH CLOUDS
FROM CONVECTION IN NEBRASKA STREAMING SOUTHEAST...AND SOME OF THIS
MAY CLIP THE SOUTHWEST PARTS OF THE CWA OVERNIGHT.
HAVE MADE SOME MINOR EDITS TO THE HOURLY GRIDS...BUT THE OVERALL
TEMPERATURE FORECAST STILL LOOKS GOOD. LOWS TONIGHT MAINLY IN THE
MID 50S WITH SOME LOWER 50S NORTH OF I-74. RECORD LOWS ARE LARGELY
IN THE UPPER 40S TO AROUND 50...BUT SPRINGFIELD MAY COME CLOSE TO
ITS RECORD OF 54 SET IN 2000.
GEELHART
&&
.AVIATION...
ISSUED 610 PM CDT WED JUL 24 2013
DIURNAL CUMULUS THAT IS WIDESPREAD WEST OF A KBMI-KSPI LINE SHOULD
START FADING OVER THE NEXT HOUR OR SO. A THICKER AREA OF CLOUDS
AROUND 6000 FEET WAS ADVANCING FROM EASTERN IOWA...BUT SUBSIDENCE
BEHIND IT IS ERODING THE CLOUDS FROM THE WEST...AND HUMIDITY PLOTS
FROM THE RAP AND NAM MODEL SHOW THIS CONTINUING TO DIMINISH AS IT
MOVES TOWARD CENTRAL ILLINOIS. SOME ADDITIONAL DEVELOPMENT
POSSIBLE TOWARD 18Z...BUT MOST LIKELY NEAR KPIA NORTHWEST. WINDS
REMAIN LIGHT AND VARIABLE MUCH OF THE PERIOD...BUT SHOULD START
BECOMING A MORE CONSISTENT SOUTHERLY DIRECTION BY LATE AFTERNOON
AS AN UPPER WAVE MOVES INTO WESTERN IOWA.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT WED JUL 24 2013
12Z MODELS HAVE TRENDED QUICKER WITH FRONTAL BOUNDARY AND CHANCES
OF SHOWERS/THUNDERSTORMS LATE THIS WEEK. ANOTHER WEATHER SYSTEM TO
AFFECT THE AREA MONDAY NIGHT/TUE AND EXTENDED MODELS IN OK
AGREEMENT HERE. MET/MAV GUIDANCE TEMPS SIMILAR THROUGH FRI NIGHT
EXCEPT LEANED ON MILDER MAV HIGHS ON FRI WHICH ARE ABOUT 5 DEGREES
HIGHER THAN THE MET HIGHS.
SHORT TERM...TODAY THROUGH SATURDAY
1019 MB HIGH PRESSURE OVER WI/MI TO DRIFT EAST INTO THE EASTERN
GREAT LAKES AND ST LAWRENCE SEAWAY THU AND RIDGE SW INTO IL AND
CONTINUE FAIR WEATHER THROUGH THU NIGHT. PLEASANT TEMPS AND
HUMIDITY LEVELS EXPECTED TO CONTINUE. LOWS TONIGHT CLOSE TO
DEWPOINTS IN THE LOW TO MID 50S AS SCATTERED DIURNALLY DRIVEN
CUMULUS CLOUDS ESPECIALLY NW OF THE IL RIVER DISSIPATE AS SUNSET
WITH NNE WINDS BECOMING LIGHT. A FAIR AMOUNT OF SUNSHINE EXPECTED
THU WITH HIGHS A FEW DEGREES ABOVE TODAY IN THE UPPER 70S TO NEAR
80F. LOWS THU NIGHT RANGE FROM THE MID 50S OVER EAST CENTRAL IL
NEAR THE INDIANA BORDER TO THE LOWER 60S WESTERN AREAS.
A NORTHERN STREAM SHORT WAVE OVER THE SOUTHERN CANADIAN PRAIRIE
PROVINCES TO DIVE SE INTO THE UPPER MS VALLEY BY SUNSET FRI AND
DRIVE A COLD FRONT SE THRU IL FRI AFTERNOON THRU IL RIVER VALLEY
AND CENTRAL/SE IL FRI EVENING. MODELS SHOW BRUNT OF QPF BREAKING
UP AND PASSING NORTH OF CENTRAL IL AND SW OF MO/OZARKS SO KEEPING
JUST 20-40% POPS IN FORECAST FRI/FRI NIGHT AND GENERALLY DRY SAT
DUE TO FASTER MOVEMENT OF FRONT. SOME COOL WEATHER ARRIVES BEHIND
THE FRONT THIS WEEKEND WITH HIGHS IN THE 70S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
QUIET WEATHER EXPECTED SAT NIGHT THROUGH MON ACROSS CENTRAL/SE IL
AS HIGH PRESSURE SETTLES INTO IL/IN BY SUNSET SUNDAY AND THEN
SHIFTS EAST OF IL MONDAY. ANOTHER TO EJECT EASTWARD IN SEMI-ZONAL
UPPER LEVEL FLOW INTO THE REGION MON NIGHT/TUE BRINGING NEXT
CHANCE OF SHOWERS AND THUNDERSTORMS...AND SHIFTING TO THE SE INTO
THE OHIO VALLEY DURING WED.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
610 PM CDT WED JUL 24 2013
.DISCUSSION...
ISSUED 300 PM CDT WED JUL 24 2013
12Z MODELS HAVE TRENDED QUICKER WITH FRONTAL BOUNDARY AND CHANCES
OF SHOWERS/THUNDERSTORMS LATE THIS WEEK. ANOTHER WEATHER SYSTEM TO
AFFECT THE AREA MONDAY NIGHT/TUE AND EXTENDED MODELS IN OK
AGREEMENT HERE. MET/MAV GUIDANCE TEMPS SIMILAR THROUGH FRI NIGHT
EXCEPT LEANED ON MILDER MAV HIGHS ON FRI WHICH ARE ABOUT 5 DEGREES
HIGHER THAN THE MET HIGHS.
SHORT TERM...TODAY THROUGH SATURDAY
1019 MB HIGH PRESSURE OVER WI/MI TO DRIFT EAST INTO THE EASTERN
GREAT LAKES AND ST LAWRENCE SEAWAY THU AND RIDGE SW INTO IL AND
CONTINUE FAIR WEATHER THROUGH THU NIGHT. PLEASANT TEMPS AND
HUMIDITY LEVELS EXPECTED TO CONTINUE. LOWS TONIGHT CLOSE TO
DEWPOINTS IN THE LOW TO MID 50S AS SCATTERED DIURNALLY DRIVEN
CUMULUS CLOUDS ESPECIALLY NW OF THE IL RIVER DISSIPATE AS SUNSET
WITH NNE WINDS BECOMING LIGHT. A FAIR AMOUNT OF SUNSHINE EXPECTED
THU WITH HIGHS A FEW DEGREES ABOVE TODAY IN THE UPPER 70S TO NEAR
80F. LOWS THU NIGHT RANGE FROM THE MID 50S OVER EAST CENTRAL IL
NEAR THE INDIANA BORDER TO THE LOWER 60S WESTERN AREAS.
A NORTHERN STREAM SHORT WAVE OVER THE SOUTHERN CANADIAN PRAIRIE
PROVINCES TO DIVE SE INTO THE UPPER MS VALLEY BY SUNSET FRI AND
DRIVE A COLD FRONT SE THRU IL FRI AFTERNOON THRU IL RIVER VALLEY
AND CENTRAL/SE IL FRI EVENING. MODELS SHOW BRUNT OF QPF BREAKING
UP AND PASSING NORTH OF CENTRAL IL AND SW OF MO/OZARKS SO KEEPING
JUST 20-40% POPS IN FORECAST FRI/FRI NIGHT AND GENERALLY DRY SAT
DUE TO FASTER MOVEMENT OF FRONT. SOME COOL WEATHER ARRIVES BEHIND
THE FRONT THIS WEEKEND WITH HIGHS IN THE 70S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
QUIET WEATHER EXPECTED SAT NIGHT THROUGH MON ACROSS CENTRAL/SE IL
AS HIGH PRESSURE SETTLES INTO IL/IN BY SUNSET SUNDAY AND THEN
SHIFTS EAST OF IL MONDAY. ANOTHER TO EJECT EASTWARD IN SEMI-ZONAL
UPPER LEVEL FLOW INTO THE REGION MON NIGHT/TUE BRINGING NEXT
CHANCE OF SHOWERS AND THUNDERSTORMS...AND SHIFTING TO THE SE INTO
THE OHIO VALLEY DURING WED.
07
&&
.AVIATION...
ISSUED 610 PM CDT WED JUL 24 2013
DIURNAL CUMULUS THAT IS WIDESPREAD WEST OF A KBMI-KSPI LINE SHOULD
START FADING OVER THE NEXT HOUR OR SO. A THICKER AREA OF CLOUDS
AROUND 6000 FEET WAS ADVANCING FROM EASTERN IOWA...BUT SUBSIDENCE
BEHIND IT IS ERODING THE CLOUDS FROM THE WEST...AND HUMIDITY PLOTS
FROM THE RAP AND NAM MODEL SHOW THIS CONTINUING TO DIMINISH AS IT
MOVES TOWARD CENTRAL ILLINOIS. SOME ADDITIONAL DEVELOPMENT
POSSIBLE TOWARD 18Z...BUT MOST LIKELY NEAR KPIA NORTHWEST. WINDS
REMAIN LIGHT AND VARIABLE MUCH OF THE PERIOD...BUT SHOULD START
BECOMING A MORE CONSISTENT SOUTHERLY DIRECTION BY LATE AFTERNOON
AS AN UPPER WAVE MOVES INTO WESTERN IOWA.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 PM CDT TUE JUL 23 2013
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 925 AM CDT TUE JUL 23 2013
THE 23.12Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW STRETCHING
FROM OREGON TO THE MIDWEST. MAGNITUDES WERE 50-75 KT. @ 500 HPA, AN
ELONGATED 592/593 DM ANTICYCLONE EXTENDED FROM NORTHERN NEVADA SE TO
NW NEW MEXICO. DOWNSTREAM, A BROAD TROF WAS MOVING ACROSS THE EASTERN
UNITED STATES. @ 700 HPA, 2 DEG C OF WARMING OCCURRED AT KDDC BETWEEN
22.12Z AND 23.12Z SYNOPTIC FLIGHTS AND AT A FAIRLY WARM TEMP OF 15
DEG C THIS MORNING. @ 850 HPA, KDDC WAS AT 26 DEG C, WHICH IS ABOVE
THE 75TH PERCENTILE. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SW KANSAS. AN OUTFLOW BOUNDARY WAS DRAPED ACROSS THE FORECAST AREA
OF RESPONSIBILITY. INVEST 98E WAS LOCATED 800 MILES SSW OF THE SOUTHERN
TIP OF BAJA CALIFORNIA. INVEST 98L WAS LOCATED A COUPLE HUNDRED MILES
SSE OF THE CAPE VERDE ISLANDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013
TONIGHT:
NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.
TOMORROW:
AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 PM CDT TUE JUL 23 2013
THE SYSTEM THAT MOVED WESTWARD ALONG THE SOUTHERN EDGE OF THE UPPER
LEVEL RIDGE LAST WEEK WAS LOCATED NEAR THE CALIFORNIA COAST TODAY AND
IS POISED TO MOVE BACK EASTWARD ON THE NORTHERN SIDE OF THE UPPER
LEVEL RIDGE. BY WEDNESDAY NIGHT AND THURSDAY, THIS SYSTEM WILL BE
APPROACHING FROM THE WEST. A STATIONARY FRONT WILL BE LOCATED
OVER THE SOUTHERN PLAINS, WITH UPSLOPE FLOW AND ABUNDANT LOW LEVEL
MOISTURE ON THE COOL SIDE OF THE FRONT OVER WESTERN KANSAS. WE ARE
EXPECTING THUNDERSTORMS TO DEVELOP OVER COLORADO AND THEN EXPAND
INTO A LARGER CLUSTER OF STORMS OVER THE PLAINS. THE EXACT
POSITIONING OF THIS STORM CLUSTER IS UNCERTAIN. SO FOR NOW, RAIN
CHANCES WERE KEPT AT 40-50% FOR LATE WEDNESDAY NIGHT INTO THURSDAY
NIGHT.
AFTER THE AFOREMENTIONED SYSTEM PASSES BY FRIDAY MORNING, A BREAK IN
PRECIPITATION IS EXPECTED FRIDAY AND SATURDAY, WITH CONTINUED
COOL WEATHER (HIGHS MAINLY IN THE 80S AND LOWS IN THE 60S). BY
THE WEEKEND, THE MID TO UPPER LEVEL FLOW WILL BECOME MORE
WEST-NORTHWESTERLY AGAIN, RESULTING IN RENEWED WEAK SURFACE LEE TROUGHING
AND WARM/MOIST ADVECTION INTO WESTERN KANSAS. THEREFORE, THERE
ARE CHANCES OF THUNDERSTORMS AGAIN BY SATURDAY NIGHT INTO MONDAY,
WITH CONTINUED COOL WEATHER (HIGHS MAINLY 80S).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013
SOME WEATHER AND POSSIBLE REDUCTION IN FLIGHT CATEGORY IS PSBL THROUGH
TAF PD. FIRST IS CONVECTION LATE THIS AFTERNOON/EVENING. STORMS SHOULD
INITIATE ALONG FRONTAL BOUNDARY. DO NOT HAVE HIGH CONFIDENCE IN TEMPORAL
AND SPATIAL DISTRIBUTION OF ACTIVITY AND WILL LEAVE OUT OF TAFS FOR
NOW. SECOND CONCERN IS PSBL MVFR CIGS IN TOMORROW MORNING. OTHERWISE,
SOUTHERLY WIND VECTORS WILL BECOME NORTHEASTERLY WITH 10-20 KT MAGNITUDES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 91 69 86 / 20 10 40 50
GCK 67 90 68 86 / 10 10 50 50
EHA 67 91 68 87 / 10 20 50 50
LBL 69 93 69 89 / 20 10 40 50
HYS 66 88 68 84 / 20 10 40 50
P28 71 90 71 89 / 20 10 40 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
200 PM CDT TUE JUL 23 2013
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 925 AM CDT TUE JUL 23 2013
THE 23.12Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW STRETCHING
FROM OREGON TO THE MIDWEST. MAGNITUDES WERE 50-75 KT. @ 500 HPA, AN
ELONGATED 592/593 DM ANTICYCLONE EXTENDED FROM NORTHERN NEVADA SE TO
NW NEW MEXICO. DOWNSTREAM, A BROAD TROF WAS MOVING ACROSS THE EASTERN
UNITED STATES. @ 700 HPA, 2 DEG C OF WARMING OCCURRED AT KDDC BETWEEN
22.12Z AND 23.12Z SYNOPTIC FLIGHTS AND AT A FAIRLY WARM TEMP OF 15
DEG C THIS MORNING. @ 850 HPA, KDDC WAS AT 26 DEG C, WHICH IS ABOVE
THE 75TH PERCENTILE. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SW KANSAS. AN OUTFLOW BOUNDARY WAS DRAPED ACROSS THE FORECAST AREA
OF RESPONSIBILITY. INVEST 98E WAS LOCATED 800 MILES SSW OF THE SOUTHERN
TIP OF BAJA CALIFORNIA. INVEST 98L WAS LOCATED A COUPLE HUNDRED MILES
SSE OF THE CAPE VERDE ISLANDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013
TONIGHT:
NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.
TOMORROW:
AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 323 AM CDT TUE JUL 23 2013
THE UPPER LEVEL WEATHER PATTERN DURING THE EXTENDED PERIOD WILL
GENERALLY BE DEPICTED BY AN AREA OF HIGH PRESSURE ACROSS THE
SOUTHWEST UNITED STATES THROUGH SATURDAY SHIFTING TO THE SOUTHERN
PLAINS BY EARLY NEXT WEEK. THIS IS DUE TO A TROUGH OF LOW PRESSURE
MOVING INTO THE PACIFIC NORTHWEST. ALSO, AN UPPER LEVEL LONG WAVE
TROUGH WILL BE POSITIONED ACROSS THE EASTERN UNITED STATES. A
FEW SHORTWAVES ARE PROGGED TO MOVE AROUND THE PERIPHERY OF THE UPPER
LEVEL HIGH AND INTO THE CENTRAL PLAINS. THIS WILL ENHANCE LIFT
ACROSS WESTERN KANSAS AND PUSH A FEW SURFACE FEATURES THROUGH THE
AREA.
THE FIRST SHORTWAVE IS FORECASTED TO MOVE THROUGH THE AREA ON
THURSDAY. THIS FEATURE WILL COINCIDE WITH A STATIONARY FRONT AT THE
SURFACE LOCATED ACROSS OKLAHOMA AND OK/TX PANHANDLES CURLING
NORTHWARD ACROSS EASTERN COLORADO. WINDS WILL GENERALLY HAVE AN
EASTERLY COMPONENT WEDNESDAY THROUGH THURSDAY ALLOWING UPSLOPE FLOW
TO OCCUR ACROSS WESTERN KANSAS. THUNDERSTORMS ARE EXPECTED TO FORM
ACROSS EASTERN COLORADO WEDNESDAY AFTERNOON AND MOVE INTO WESTERN
KANSAS WEDNESDAY NIGHT. THUNDERSTORM CHANCES BECOME LIKELY ON
THURSDAY WITH COOLER TEMPERATURES. PRECIPITATION CHANCES THEN END
FROM WEST TO EAST FRIDAY AS THE UPPER LEVEL DISTURBANCE MOVES
SOUTHEAST OF THE CWA. HIGHS WEDNESDAY WILL BE AROUND 90S DEGREES
DROPPING INTO THE 80S THURSDAY AND FRIDAY. LOWS THURSDAY AND FRIDAY
MORNING WILL GENERALLY BE IN THE MID TO UPPER 60S WITH THE EXCEPTION
OF SOUTH CENTRAL KANSAS WHERE LOWER 70S COULD OCCUR.
A LULL IN THE ACTION IS EXPECTED FRIDAY NIGHT INTO SATURDAY LEAVING
PARTLY CLOUDY SKIES AND DRY CONDITIONS. THIS WILL BE SHORT LIVED AS
MODELS SUGGEST A FEW WEAK UPPER LEVEL DISTURBANCES MOVING THROUGH THE
AREA SATURDAY NIGHT TO THE BEGINNING OF NEXT WEEK. WINDS DURING THIS
TIMEFRAME WILL GENERALLY BE FROM THE SOUTHEAST WITH MOSTLY CLOUDY
SKIES. I AM LESS CONFIDENT WITH THIS SYSTEM AS THURSDAY AND MAY NEED
TO BE TWEAKED DURING FUTURE FORECAST UPDATES. AS FOR TEMPERATURES,
HIGHS WILL CONTINUE TO BE IN THE 80S SATURDAY AND SUNDAY BEFORE
RISING INTO THE LOWER 90S ON MONDAY. LOWS SATURDAY AND SUNDAY
MORNING ARE FORECASTED TO BE IN THE 60S WITH UPPER 60S TO LOWER 70S
MONDAY MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013
SOME WEATHER AND POSSIBLE REDUCTION IN FLIGHT CATEGORY IS PSBL THROUGH
TAF PD. FIRST IS CONVECTION LATE THIS AFTERNOON/EVENING. STORMS SHOULD
INITIATE ALONG FRONTAL BOUNDARY. DO NOT HAVE HIGH CONFIDENCE IN TEMPORAL
AND SPATIAL DISTRIBUTION OF ACTIVITY AND WILL LEAVE OUT OF TAFS FOR
NOW. SECOND CONCERN IS PSBL MVFR CIGS IN TOMORROW MORNING. OTHERWISE,
SOUTHERLY WIND VECTORS WILL BECOME NORTHEASTERLY WITH 10-20 KT MAGNITUDES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 91 69 86 / 20 10 50 60
GCK 67 90 68 86 / 10 10 50 60
EHA 67 91 68 87 / 10 20 50 50
LBL 69 93 69 89 / 20 10 50 50
HYS 66 88 68 84 / 20 10 40 60
P28 71 90 71 89 / 20 10 40 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...HOVORKA_42
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1220 PM CDT TUE JUL 23 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013
FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.
EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.
TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013
A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.
WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.
FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.
SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1217 PM CDT TUE JUL 23 2013
VERY UNCERTAIN FORECAST IN TERMS OF LOCATION/TIMING/INTENSITY OF
THUNDERSTORM POTENTIAL. FOR THE NEAR TERM...APPEARS MORNING
CONVECTION WILL DELAY REDEVELOPMENT AND COULD SAVE STRONGER STORMS
FOR SOUTH OF THE TERMINALS. HAVE GONE WITH VCTS FOLLOWED BY VCSH
FOR THE OVERNIGHT HOURS AND WILL MONITOR FOR UPDATES. DID
INTRODUCE MVFR CIGS POST MAIN COLD FRONT FOR THE MORNING HOURS ALL
SITES BUT EXPECT THIS WOULD MIX OUT LATE MORNING.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...67
AREA FORECAST DISCUSSION
NWS TOPEKA KS
615 AM CDT TUE JUL 23 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013
FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.
EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.
TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013
A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.
WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.
FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.
SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 610 AM CDT TUE JUL 23 2013
ACTIVE WEATHER IN STORE FOR THE TERMINALS THROUGH THE NEXT 24
HOURS. THE FIRST ROUND OF ACTIVE WEATHER WILL ACCOMPANY AN OUTFLOW
BOUNDARY WHICH WILL FLOW THROUGH KMHK AROUND 12Z AND THE TOPEKA
TERMINALS AROUND 13Z. THESE WINDS WILL BE AROUND 20 TO 30 KTS OUT
OF THE N/NE. A FEW SCATTERED THUNDERSTORMS MAY FORM TO THE NORTH
OF THE SOUTHWARD MOVING BOUNDARY...AND MAY BRING BRIEF PERIODS OF
MODERATE TO HEAVY RAIN TO THE TERMINALS. ANOTHER ROUND OF SHOWERS
WILL FORM LATER THIS AFTERNOON...WITH BETTER CHANCES OF
THUNDERSTORMS AFFECTING THE TERMINALS. EXPECT THESE STORMS TO
PRODUCE STRONG GUSTY CHAOTIC OUTFLOW WINDS AT AND AROUND THE
TERMINALS. RAIN CHANCES WILL DIMINISH OVERNIGHT.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...LEIGHTON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
402 AM CDT TUE JUL 23 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CDT TUE JUL 23 2013
FAIRLY STRONG NORTHWESTERLY H5 FLOW...CONSIDERING THE MID SUMMER
TIME PERIOD...CURRENTLY OVER THE FORECAST AREA BETWEEN THE MID
LEVEL HIGH OVER THE DESERT SOUTHWEST AND AN UPPER TROUGH LOCATED
NORTH OF THE GREAT LAKES REGION. TWO AREAS OF CONVECTION ARE
APPARENT ON RADAR...WITH AN AREA OF WEAK THUNDERSTORMS OVER
CENTRAL KANSAS...AND A MORE ORGANIZED COMPLEX OF STORMS CURRENTLY
IN C NEBRASKA. GENERALLY EXPECT THE WEAK THUNDERSTORMS OVER
CENTRAL KANSAS TO WEAKEN WHILE STAYING SLIGHTLY WEST OF THE
FORECAST AREA. THE FOCUS WOULD THEN SHIFT TO THE MCS DRIVING ESE
ACROSS C/S NEBRASKA. FORWARD PROPAGATING CORFIDI VECTORS WOULD
INDICATE THAT THE STORMS WILL CONTINUE THEIR PATH TO THE
ESE...PERHAPS BRINGING SOME EARLY MORNING THUNDERSTORMS TO THE
NORTHERN ROW OR TWO OF COUNTIES...WITH THE BEST CHANCES FOR
MORNING PRECIP BEING IN THE FAR NORTHEASTERN CORNER OF KANSAS.
MODELS HAVE BEEN HAVING TROUBLE RESOLVING MCS DEVELOPMENT THE
PREVIOUS COUPLE NIGHTS...SO WILL TAKE THEIR SOLUTIONS WITH A GRAIN
OF SALT. 4KM WRF-NMM WOULD SUGGEST THE COMPLEX WILL FALL APART AS
IT APPROACHES THE CWA...WHILE THE HRRR SUGGESTS IT WILL MAINTAIN
ITSELF IN SOME RESPECT TO THE NORTHERN TIER OF COUNTIES. CURRENTLY
WILL SIDE MORE WITH THE HRRR...AS RADAR TRENDS OVER THE PAST
COUPLE HOURS SHOW THE COMPLEX STILL STRONG AND ORGANIZED AS IT
MOVES ACROSS C NEBRASKA. IT ALSO SEEMS TO BE MAINTAINED ALONG THE
LEADING EDGE OF A 20 TO 30 KT 850 MB JET...WITH MAXIMIZED LOW
LEVEL CONVERGENCE RUNNING NW TO SE ACROSS C/S NEBRASKA. BETWEEN
THAT LINE OF MAXIMIZED LOW LEVEL CONVERGENCE AND THE
AFOREMENTIONED CORFIDI VECTORS...HAVE KEPT THE HIGHEST POPS
THROUGH THE MORNING HOURS ALONG AND NORTH OF INTERSTATE 70...WITH
POPS INCREASING TOWARD THE NORTHEAST PART OF KS.
EXACT THUNDERSTORM DEVELOPMENT FOR TUESDAY AFTERNOON IS SOMEWHAT
UNCERTAIN...AS THE DECAYING MCS WILL LIKELY LEAVE A REMNANT OUTFLOW
BOUNDARY ACROSS THE CWA AS IT CONTINUES ESE. THE REMNANT BOUNDARY
COULD BE THE IMPETUS FOR MORE THUNDERSTORM DEVELOPMENT LATER TODAY
WHERE LOW LEVEL CONVERGENCE IS MAXIMIZED. IN THE UNLIKELY CASE THAT
THE OFB SLIDES COMPLETELY THROUGH THE AREA AND SETS UP SOUTH OF THE
CWA IT COULD DECREASE CHANCES FOR RAIN LATER TODAY...HOWEVER THE
GENERAL THOUGHT IS THAT THAT BOUNDARY WILL REMAIN SOMEWHERE IN
NORTHEAST KANSAS. ASIDE FROM THE MAXIMIZED CONVERGENCE ALONG THE
BOUNDARY MODELS WOULD SUGGEST AN EMBEDDED VORTICITY MAXIMUM IN THE
NORTHWEST H5 FLOW. AS THIS VORT MAX SLIDES THROUGH THE AREA IT
SHOULD BRING INCREASED CHANCES FOR THUNDERSTORMS LATER THIS
AFTERNOON. GIVEN GOOD INSTABILITY IN THE FORM OF ROUGHLY 3000 J/KG
OF MIXED LAYER CAPE AND 0-6 BULK SHEAR VALUES OF PERHAPS 40
KTS...THE INGREDIENTS WILL BE PRESENT FOR SOME OF THESE AFTERNOON
THUNDERSTORMS TO BECOME STRONG TO SEVERE. THE MAIN HAZARDS WOULD BE
HAIL AND WIND...AS WELL AS HEAVY RAIN. EXPECT THESE STORMS TO FORM
INTO A COMPLEX BY SUNSET...AND MOVE SOUTHEASTWARD INTO WESTERN
MISSOURI DURING THE OVERNIGHT HOURS.
TEMPERATURE FORECAST FOR TUESDAY IS ALSO SOMEWHAT QUESTIONABLE AS
THAT OUTFLOW BOUNDARY FROM THE MORNING MCS WILL LIKELY DICTATE WHERE
THE WARMER TEMPS WILL BE LOCATED...VS COOLER TEMPS BEHIND THE
BOUNDARY. HAVE GONE WITH A FORECAST THE REFLECTS THE OFB ALONG WITH
ANY CLOUD DEBRIS FROM THE MCS TO REMAIN ALONG AND NORTH OF I
70...WITH WARMER TEMPS...INTO THE LOWER TO MID 90S ALONG AND SOUTH
OF THE INTERSTATE. THIS FORECAST COULD CHANGE BASED ON HOW
PROGRESSIVE THAT BOUNDARY AND ANY LINGERING CLOUD COVER MAY BE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 356 AM CDT TUE JUL 23 2013
A LONGER WAVE LENGTH UPPER LEVEL TROUGH WILL REMAIN NEARLY
STATIONARY ACROSS THE EAST CENTRAL CONUS. THIS UPPER AIR PATTERN
WILL CAUSE THE FLOW AT MID AND UPPER LEVELS TO REMAIN
NORTHWESTERLY ACROSS THE PLAINS. A SERIES OF SHORTER WAVE-LENGTH
UPPER LEVEL TROUGHS WILL ROUND THE UPPER LEVEL RIDGE ACROSS THE
WESTERN CONUS AND DIG SOUTHEAST ACROSS THE CENTRAL PLAINS THROUGH
THE FORECAST PERIOD.
WEDNESDAY...THE FIRST H5 TROUGH WILL MOVE SOUTHEAST ACROSS NE INTO
MO WEDNESDAY MORNING. AN MCS OR COMPLEX OF THUNDERSTORMS MAY BE
ONGOING DURING THE MORNING HOURS. HOWEVER...THE STRONGER ASCENT
AHEAD OF THIS H5 TROUGH MAY REMAIN JUST NORTH AND EAST OF THE CWA. A
SURFACE OUTFLOW BOUNDARY/COLD FRONT SHOULD PUSH SOUTH AND SOUTHWEST
ACROSS THE CWA DURING THE MORNING HOURS. THE AFTERNOON MAY REMAIN
DRY AS THE BEST SURFACE CONVERGENCE WILL REMAIN SOUTH AND WEST OF
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL ONLY REACH THE MID
80S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT....THE NEXT H5 TROUGH MAY
DIG SOUTHEAST ACROSS THE PLAINS THURSDAY INTO FRIDAY MORNING. BOTH
THE ECMWF AND GFS SHOW AN MCS DEVELOPING ACROSS THE HIGH PLAINS OF
EASTERN CO AND TRACKING SOUTHEAST ACROSS WESTERN KS INTO SOUTHERN KS
AND NORTHERN OK. THE CWA MAY REMAIN ON THE NORTH EDGE OF THIS MCS
TRACK. IF THE MCS DEVELOPS FARTHER NORTH...THEN THE CWA MAY SEE A
GREATER CHANCE FOR THUNDERSTORMS THURSDAY NIGHT INTO FRIDAY MORNING.
THIS WILL BE MORE OF A MESOSCALE FORECAST AND FOR NOW I JUST WENT
WITH CHANCE POPS. HIGHS MAY WARM BACK INTO THE UPPER 80S TO AROUND
90 DEGREES THURSDAY AFTERNOON.
FRIDAY THROUGH SUNDAY...OUTFLOW BOUNDARIES AND WEAK UPPER LEVEL
TROUGHS DIGGING SOUTHEAST ACROSS THE PLAINS MAY PROVIDE ENOUGH
ASCENT FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
PERIOD. HIGHS SHOULD REMAIN IN THE 80S.
SUNDAY NIGHT AND MONDAY...BOTH THE GFS AND ECMWF SHOW ANOTHER H5
TROUGH TRACKING EAST-SOUTHEAST ACROSS THE PLAINS. ASCENT AHEAD OF
THE TROUGH MAY LEAD TO AN MCS DEVELOPING ACROSS WESTERN KS AND
WESTERN NE THAT MAY TRACK EAST-SOUTHEAST ACROSS THE CWA SUNDAY NIGHT
INTO MONDAY MORNING. MONDAY HIGHS WILL ONCE AGAIN BE IN THE LOWER TO
MID 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1128 PM CDT MON JUL 22 2013
WILL MAINTAIN A VFR FORECAST THROUGH THE NIGHT AS NO OBVIOUS
FORCING IS SEEN IN THE NEXT SEVERAL HOURS AND STEERING FLOW SHOULD
KEEP ONGOING CONVECTION MOVING AWAY FROM THE TERMINALS. THINK
THERE IS A CHANCE FOR SCATTERED CONVECTION BY TUESDAY AFTERNOON.
SEE UPDATED DISCUSSION ABOVE FOR FURTHER DETAILS. MAIN UNCERTAINTY
IS WHETHER PRECIP ACROSS NORTHWEST NEB CAN HOLD TOGETHER. IF IT
DOES...IT LOOKS TO MOVE INTO KS AFT 12Z. SO WILL LET THE NEXT
SHIFT MONITOR TRENDS. MAY INCLUDE A MENTION OF VCTS BY EARLY
AFTERNOON AS THIS LOOKS LIKE THE BEST TIMING FOR LIFT...INSTABILITY
AND FORCING TO COME TOGETHER.
SFC DEWPOINT TEMPS HAVE NOT RISEN MUCH...BUT AIR TEMPS HAVE COOLED
OFF MORE RAPIDLY THEN ANTICIPATED. BECAUSE OF THIS MAY PUT A TEMPO
GROUP IN FOR SOME GROUND FOG...ESPECIALLY AT MHK AND TOP.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JL
LONG TERM...GARGAN
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1128 PM CDT MON JUL 22 2013
.UPDATE...
ISSUED AT 1128 PM CDT MON JUL 22 2013
FORECAST THINKING HAS NOT CHANGED MUCH WITH THE 00Z MODEL RUNS
COMING IN. THE SYNOPTIC SCALE FRONT IS MAKING SLOW BUT STEADY
PROGRESS SOUTH. AND ALL SHORT TERM GUIDANCE SHOWS THE BOUNDARY
BISECTING THE FORECAST AREA THROUGH THE AFTERNOON TUESDAY.
MEANWHILE THE CONVECTION ONGOING SEEMS TO HAVE OCCURRED EVERYWHERE
BUT IN THE FORECAST AREA. BACKWARD PROPAGATING CORFIDI VECTORS
WOULD SUGGEST THE CONVECTION IN CENTRAL KS WILL MOVE SOUTH AND
SOUTHWEST WHILE THE CONVECTION NEAR THE IA/MO STATE LINE WOULD
PROPAGATE DUE SOUTH. WITH THIS IN MIND WILL MAINTAIN A SLIGHT
CHANCE POP DURING THE OVERNIGHT HOURS. THINK THAT CHANCES FOR
PRECIP WILL INCREASE THROUGH THE DAY TUESDAY AS A POSSIBLE MCV
FROM THE SD CONVECTION MOVES ACROSS THE FRONTAL BOUNDARY.
CONFIDENCE IN THE MODEL QPF SOLUTIONS IS STILL QUESTIONABLE...BUT
THERE SEEMS TO BE SOME LIFT AND FORCING MECHANISM AVAILABLE TO
ACT UPON THE VERY MOIST AIRMASS. BECAUSE OF THIS THERE COULD BE
SOME SCATTERED CONVECTION ACROSS NORTHEAST KS BY THE EARLY
AFTERNOON. CAN NOT RULE OUT THE CHANCE FOR SOME PRECIP MOVING INTO
NORTHERN KS BEFORE NOON IF STORMS OVER NORTHWEST NEB HOLD
TOGETHER. WITH SKIES REMAINING MOSTLY CLEAR...MAY HAVE TO LOWER
TEMPS A COUPLE DEGREES AS CONDITIONS FAVOR CONTINUED RADIATIONAL
COOLING.
UPDATE ISSUED AT 603 PM CDT MON JUL 22 2013
23Z OBJECTIVE ANALYSIS SHOWS THE FRONTAL BOUNDARY STILL WELL NORTH
OF THE FORECAST AREA FROM NORTH CENTRAL IA...NORTH OF OMA INTO
CENTRAL NEB. WHILE LAPS ANALYSIS SUGGESTS CAPE VALUES ON THE ORDER
OF 4000 J/KG...RECENT VISIBLE IMAGERY DOES NOT SHOW MUCH IN THE
WAY OF A CU FIELD ACROSS THE AREA IN SPITE OF SEVERAL OUTFLOW
BOUNDARIES IN THE AREA. ADDITIONALLY WATER VAPOR SHOWS MID LEVEL
DRYING OVERSPREADING THE FORECAST AREA FROM THE WEST AND NORTHWEST
SUGGESTING THE MAIN VORT MAX IS CURRENTLY OVERHEAD AND MOVING
SOUTHEAST. THE 18Z NAM LOOKS TO BE A LITTLE TO FAR SOUTH WITH THE
FRONTAL BOUNDARY AND PREFER THE RUC13 DEPICTION OF THE LARGE
SCALE PRESSURE FIELD WHICH KEEPS THE MAIN FRONT MAINLY TO THE
NORTH. SO IN GENERAL THINKING IS ANY CONVECTION EARLY THIS
EVENING IS LIKELY TO REMAIN ISOLATED. WITH THE AVAILABLE
INSTABILITY...ANY STORM THAT FORMS WILL HAVE THE POTENTIAL TO
DEVELOP RAPIDLY. HOWEVER THINK THE BETTER CHANCES FOR SCATTERED TO
NUMEROUS STORMS COULD BE DURING THE DAY TUESDAY AS THE BOUNDARY
SETS UP ACROSS KS. WITH MODELS SHOWING THE LOW LEVEL JET FOCUSING
ACROSS SOUTHEAST KS OVERNIGHT...THINK BEST CHANCES FOR STORMS IN
THE EARLY MORNING MAY COME FROM CONVECTION CURRENTLY DEVELOPING
OVER THE HIGH PLAINS OF WY. THE RAP AND HRRR SHOW SIGNS OF THIS
PRECIP HOLDING TOGETHER AND MOVING INTO THE AREA BEFORE DAWN. WILL
MONITOR TRENDS BUT MAY ADJUST THE FORECAST TO LOWER POPS THIS
EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013
STORMS AND CLOUD COVER FROM EARLIER IN THE DAY HAVE LIKELY DELAYED
THUNDERSTORM START TO THESE LATER AFTERNOON HOURS...AND A FEW OF THE
RESIDENT OUTFLOW BOUNDARIES ARE STARTING TO GENERATE CONNECTION.
STORM TO THE NORTH WENT UP QUICKLY...LIKELY IN RESPONSE TO STEEP MID
LEVEL LAPSE RATES AND AMPLE INSTABILITY. WILL BE DIFFICULT TO SAY
WHERE STORMS WILL FROM IN PARTICULAR THIS AFTERNOON AS THEY REMAIN
BOUNDARY DRIVEN. MAIN FRONT STILL PROGGED TO COME THROUGH IN THE
0-3Z WINDOW...AND EXPECT THAT THE BETTER SHEAR MORE ORGANIZED
FORCING THAT COMES WITH IT WILL STILL BRING A CHANCE FOR STORM OR
SMALL COMPLEX TO MOVE ACROSS THE CWA THIS EVENING INTO THE EARLY
MORNING HOURS. PRIMARY CONCERNS ARE WINDS AND LOCALLY HEAVY
RAINFALL...ALTHOUGH ENVIRONMENT MAY BRING SOME MARGINALLY SEVERE
HAIL AS WELL.
WHERE BOUNDARY ENDS UP COMPLICATES SENSIBLE WEATHER AND RAINFALL
CHANCES FOR TUESDAY...WITH NORTHEAST COUNTIES LIKELY COOLER AND
MOISTURE POOLING WESTWARD SHIFTS AFTERNOON RAIN CHANCES TOWARD
WESTERN COUNTIES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 22 2013
TUESDAY EVENING THROUGH THURSDAY...
BY 7 PM ON TUESDAY EVENING ISOLATED THUNDERSTORMS MAY BE ONGOING IN
THE VICINITY OF THE SURFACE FRONT OVER EAST CENTRAL AREAS.
THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE ACROSS THE AREA
TOWARDS THE EVENING AS A STRONGER SHORTWAVE EMBEDDED WITHIN THE
UPPER RIDGE TRANSLATES SOUTHEAST ACROSS EASTERN NEBRASKA INTO MISSOURI.
MODELS HAVE BEEN CONSISTENT THE PAST FEW DAYS WITH THIS SCENARIO AND
FEEL CONFIDENT TO BOOST POPS UP TO LIKELY ESPECIALLY IN THE EAST
CENTRAL AREAS. AS FAR AS STORM TYPE GOES...BEST CHANCE OF SEEING
STRONGER STORMS WILL BE CLOSER TO THE 00Z PERIOD WHERE ML CAPE
VALUES ARE PROGGED ANYWHERE FROM 1000 TO 3000 J/KG WITH THE NAM AT
12Z SHOWING 0-6 KM BULK SHEAR INCREASING UP TO 50 KTS. HIGH PRESSURE
WILL BE QUICK TO USHER SOUTHWARD BEHIND THIS SYSTEM WITH CAPE VALUES
STEADILY DECREASING AFT 06Z. GRADUALLY TRENDED POPS DOWNWARD AFT 06Z
WITH MOST OF THE AREA DRY BY WEDNESDAY MORNING. SUBSIDENCE IN PLACE
ON WEDNESDAY SHOULD BRING A TEMPORARILY LULL IN PRECIPITATION
WITH MOSTLY SUNNY SKIES AND COOLER HIGHS IN THE LOW TO MIDDLE 80S.
DURING THE AFTERNOON ON THURSDAY...THE UPPER RIDGE OVER THE
SOUTHWEST CONUS BREAKS DOWN SLIGHTLY AS A DEVELOPING A LEE TROUGH
TRACKS ACROSS THE INTER-MOUNTAIN WEST AND INTO THE CENTRAL PLAINS. THE
ECMWF AND GFS ARE STILL IN RELATIVE AGREEMENT IN BRINGING A SWATH OF
SHOWERS AND THUNDERSTORMS THURSDAY EVENING INTO FRIDAY FOR NORTHEAST
KANSAS. SLIGHT CHANCES FOR THUNDER INCREASE ON THURSDAY AFTERNOON
WITH GOOD CONFIDENCE TO ADD LIKELY CHANCES FOR THE EVENING HOURS
OVER NORTH CENTRAL KS.
TEMPERATURES DURING THIS PERIOD WILL DEPEND ON LINGERING
PRECIPITATION AND CLOUD COVER ESPECIALLY WEDNESDAY. MADE LITTLE
ADJUSTMENTS WITH WARMEST TEMPERATURES OVER NORTH CENTRAL AREAS IN
THE UPPER 80S WITH COOLER TEMPS OVER EAST CENTRAL WHERE LINGERING
SHOWERS AND CLOUD COVER MAY PERSIST. THE INCREASING CLOUD COVER AS
THE TROF APPROACHES THURSDAY WILL BE A RELATIVELY COOLER BUT HUMID
DAY WITH HIGHS IN THE LOW TO MID 80S.
THURSDAY EVENING THROUGH MONDAY...
BULK OF THE AFOREMENTIONED LOW PRESSURE SYSTEM IMPACTS THE AREA
THURSDAY EVENING INTO FRIDAY. 12Z ECMWF IS STILL TRENDING A TAD
SLOWER THAN THE 12Z GFS WITH THE CENTER OF THE TROF AXIS AND ITS
POSITION BUT OVERALL HAS BEEN IN CONSISTENT AGREEMENT SO HAVE
CARRIED CHANCES FOR THUNDERSTORMS THROUGH FRIDAY AND TAPERING OFF TO
THE EAST FRIDAY EVENING. UPPER RIDGE AMPLIFIES ONCE AGAIN HEADING
INTO THE WEEKEND WITH A QUIET PERIOD FOR SATURDAY. MODELS STILL
DIFFERING BY THE END OF THE PERIOD BUT APPEARS PATTERN STARTS TO
CHANGE TRANSITIONING TO A WESTERLY FLOW PATTERN AND ATTEMPTING TO
BRING ADDITIONAL TROFS THROUGH THE REGION SUNDAY INTO MONDAY.
DECIDED TO LOWER PRECIPITATION CHANCES TO SLIGHT AS MODEL OUTPUT IS
STILL TOO NOISY TO DISCERN ANY MAIN SOURCES OF ENERGY. TEMPERATURES ARE
ON TRACK TO REMAIN IN THE LOW 80S FOR HIGHS WITH THIS ACTIVE PATTERN
IN PLACE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1128 PM CDT MON JUL 22 2013
WILL MAINTAIN A VFR FORECAST THROUGH THE NIGHT AS NO OBVIOUS
FORCING IS SEEN IN THE NEXT SEVERAL HOURS AND STEERING FLOW SHOULD
KEEP ONGOING CONVECTION MOVING AWAY FROM THE TERMINALS. THINK
THERE IS A CHANCE FOR SCATTERED CONVECTION BY TUESDAY AFTERNOON.
SEE UPDATED DISCUSSION ABOVE FOR FURTHER DETAILS. MAIN UNCERTAINTY
IS WHETHER PRECIP ACROSS NORTHWEST NEB CAN HOLD TOGETHER. IF IT
DOES...IT LOOKS TO MOVE INTO KS AFT 12Z. SO WILL LET THE NEXT
SHIFT MONITOR TRENDS. MAY INCLUDE A MENTION OF VCTS BY EARLY
AFTERNOON AS THIS LOOKS LIKE THE BEST TIMING FOR LIFT...INSTABILITY
AND FORCING TO COME TOGETHER.
SFC DEWPOINT TEMPS HAVE NOT RISEN MUCH...BUT AIR TEMPS HAVE COOLED
OFF MORE RAPIDLY THEN ANTICIPATED. BECAUSE OF THIS MAY PUT A TEMPO
GROUP IN FOR SOME GROUND FOG...ESPECIALLY AT MHK AND TOP.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...67
LONG TERM...BOWEN
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GRAY ME
837 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT WILL STALL OFFSHORE TONIGHT. HIGH PRESSURE WILL
BUILD IN FROM THE WEST THROUGH THURSDAY. HIGH PRESSURE WILL HOLD
NEAR THE REGION FRIDAY MORNING. LOW PRESSURE WILL TRACK NORTH
ALONG THE THE FRONT FRIDAY AFTERNOON THROUGH EARLY SATURDAY.
ANOTHER SYSTEM WILL APPROACH FROM THE WEST SATURDAY NIGHT AND
SUNDAY. UNSETTLED WEATHER CONTINUES INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE...
JUST A FEW MINOR TWEAKS TO THE GRIDS TO BLEND WITH 00Z
OBSERVATIONS. CLEARING CONTINUES DOWNWIND OF THE ME/NH MOUNTAINS
LATE THIS AFTERNOON...WITH A SECOND STRIPE OF LOW CLOUD COVER
REMAINING NEAR AND ALONG THE COASTLINE. WNW FLOW AT THE SURFACE
CONTINUES TO PUSH ANY MARINE FOG EAST OF OUR WATERS THIS HOUR.
CONVECTION HAS SHIFTED EAST...AND NOW ALL THE PCPN REMAINS OVER
THE CANADIAN MARITIMES AND OVER CAPE COD. LATEST HRRR RUN KEEPS
ANY NEWLY DEVELOPING SHOWER ACTIVITY JUST EAST OF OUR COASTAL
WATERS LATE THIS EVENING.
PREV DISC...
AS EXPECTED STRONG HEATING OVER THE MIDCOAST AND DELAYED FRONTAL
PUSH THERE HAS ALLOWED ENOUGH INSTABILITY TO DEVELOP FOR STRONGER
TSTMS THIS AFTERNOON. WITH FNT CROSSING THE COAST ATTM
ELSEWHERE...THE ONLY REMAINING TSTM THREAT IS FOR THE
WALDO...LINCOLN...AND KNOX COUNTY AREAS. STORM HEIGHT IS NOT
OVERLY IMPRESSIVE...BUT PCPN LOADING IN THE COLUMN AND MARGINAL
LLVL LAPSE RATES A STRONG WIND GUST OR TWO IS PSBL.
THEN MUCH COOLER DEW POINTS FILTER INTO THE REGION FROM THE NW.
THIS COUPLED WITH CLEARING AND WEAKENING WINDS WILL SUPPORT A
COMFORTABLE NIGHT WITH LOW FALLING INTO THE 40S AND LOWER 50S.
PATCHY VALLEY FOG IS PSBL GIVEN THE RECENT RNFL AND COOL TEMPS.
&&
.SHORT TERM /THURSDAY NIGHT/...
HIGH PRES BUILDING IN FROM THE W WILL BRING PLEASANT CONDS ON
THU. EXPECT MOSTLY SUNNY SKIES...ESPECIALLY AWAY FROM THE COAST.
THE STALLED FRONTAL BOUNDARY WILL PROVIDE LINGERING CLOUDS NEAR
AND JUST OFFSHORE. WIDESPREAD HIGHS IN THE 70S ARE EXPECTED...WITH
LOW HUMIDITY.
THU NIGHT WEAK WAVE OF LOW PRES WILL BEGIN TO RIDE ALONG THE FNT.
ESPECIALLY LATE IN THE PERIOD SHRA WILL BE PSBL ACROSS SE NH AND
SW ME. THE INLAND EXTENT OF SHRA REMAINS IN QUESTION AS NWP
CONTINUES TO ADVERTISE BOTH INLAND LOW PRES TRACKS AND THOSE WELL
OUT TO SEA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
BIG QUESTION MARK FOR FRIDAY ON WHETHER A DEVELOPING COASTAL LOW
MOVING NORTH SPREADS RAIN WELL INLAND OR KEEPS MOST OF THE RAIN
OFF THE COAST. NAM/GFS DIFFER GREATLY IN POSITION OF THE COASTAL
LOW BY FRIDAY EVENING WITH THE NAM MUCH FURTHER WEST AND ALSO
IMPLYING HEAVY RAINS FOR MUCH OF THE FA WHILE THE GFS KEEPS THE
HVY RAIN OFFSHORE WITH ONLY SOME LIGHT RAINS SKIRTING SRN/ERN
AREAS OF CWA. FOR NOW WILL HAVE TO LEAN MORE TOWARD THE GFS WITH
THE SYSTEM FURTHER E, THIS ALSO GOES ALONG THE EURO THINKING. THE
NAM SEEMS TO BE THE OUTLIER FOR NOW. THE SYSTEM EXITS BY SATURDAY
WITH CLEARING BY AFTERNOON. A MEAN L/WV TROF CENTERED NEAR THE
GREAT LAKES ALLOWS YET ANOTHER S/WV TO ROTATE NEWD INTO NEW ENGL
BY SUNDAY WITH MORE RAIN PSBL THAT WILL KEEP UNSETTLES WX INTO MON
AS WELL. BY TUES THE TROF OVER THE GT LAKES KICKS OUT NEWD
ALLOWING A DRIER WLY FLOW TO RETURN FOR THE MIDWEEK TIME FRAME.
OVERALL TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL LEVELS. USED A
BLEND OF THE MAV/MET GUID FOR 4TH/5TH PDS AND THEN A BLEND OF THE
ADJUSTED MEX GUID FOR THE OUTLOOK PD.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
SHORT TERM...LOCAL MVFR/IFR CONDS ARE PSBL INVOF KRKD EARLY THIS
EVENING BEFORE VFR CONDS PREVAIL THRU THE OVERNIGHT. PATCHY VALLEY
FOG IS PSBL AFTER THE RECENT RNFL AND COOLER WX EXPECTED TONIGHT.
LOCAL IFR IN FOG IS PSBL IN THE FAVORED LOCATIONS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDS LWRG TO MVFR/IFR LATE FRI INTO EARLY SAT IN DEVELOPING AREAS
OF RAIN ESPECIALLY OVER ERN/SRN AREAS. CONDS WILL IMPROVE TO VFR
SAT BUT LOWER AGAIN TO MVFR/IFR CONDS SAT NIGHT AND INTO SUNDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BLO SCA
THRESHOLDS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...SCA CONDS DUE TO SEAS
MAY OCCUR FRI INTO SAT DUE TO SEAS AS A COASTAL LOW PASSES OFF TO
THE EAST WITH WINDS TO MAINLY REMAIN BLO SCA CONDS. WINDS/SEAS
SHOULD REMAIN BLO SCA CONDS FOR SUNDAY INTO NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
106 AM EDT TUE JUL 23 2013
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTH OVERNIGHT. THE FRONT WILL
LIFT ONTO THE COAST TUESDAY WHILE A WEAK WAVE OF LOW PRESSURE
MOVES ALONG THE FRONT. A COLD FRONT WILL APPROACH TUESDAY NIGHT
THEN CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
105 AM UPDATE...THE GOING FORECAST IS PRETTY MUCH ON TRACK. MADE
SOME ADJUSTMENTS TO EXPECTED MIN TEMPS TO MATCH CURRENT TRENDS. NO
OTHER CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...PRECIP CHANCES WERE PUSHED BACK MORE FROM EARLIER
THINKING AS HIGH PRES RIDGE IS HOLDING STRONG KEEPING RAINFALL
WELL S OF THE STATE ATTM. REGIONAL RADAR LOOP SHOWED THE BULK OF
SHOWERS AND EMBEDDED TSTMS MOVING ACROSS ERN NYS INTO VT AND MA.
NOT EXPECTING ANY MEASURABLE RAFL TO ARRIVE INTO CENTRAL AND
DOWNEAST AREAS UNTIL EARLY MONDAY MORNING. THE LATEST RUC AND
CANADIAN GEM PICKED UP ON THIS WELL. GFS AS WELL AS THE NAM APPEAR
TO BE HAVING SOME CONVECTIVE FEEDBACK ISSUES AS RAINFALL NOT AS
HEAVY AS THESE MODELS INDICATED AT THEIR 12 & 18Z RUNS. DEWPOINTS
CLIMBING WELL INTO THE 50S W/LOW TO MID 60S BACK ACROSS S AND SW
ME. THIS AREA OF HIGHER DEWPOINTS IS EXPECTED TO PUSH NE
OVERNIGHT. THIS WILL HELP TO MOISTEN LLVLS.
DID NOT INCLUDE ANY MENTION OF TSTMS OVERNIGHT AS AIRMASS LOOKS TO
REMAIN STABLE ABOVE 925MB. AIRMASS LOOKS TO DESTABILIZE MORE ON
TUESDAY PER THE GFS AND NAM SOUNDINGS. PWATS FCST TO PUSH 2+
INCHES COULD LEAD TO HEAVY RAFL AS FLOW THROUGH THE COLUMN IS SSW
W/POTENTIAL TO TRAINING CELLS.
SHOWERS AND POSSIBLE TSTMS FOR TUESDAY INCLUDING NORTHERN MAINE
W/THE HEAVIEST AXIS OF QPF ACROSS EASTERN AND DOWNEAST AREAS.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND RAIN. THEREFORE,
TUESDAY COULD A BE A COLL DAY W/DAYTIME HIGHS NOT MAKING IT OUT OF
THE UPPER 60S W/THE EXCEPTION OF FAR NORTHERN MAINE. TEMPERATURES
THERE COULD REACH INTO THE LOWER 70S BEFORE CLOUDS THICKEN UP.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
A DISTURBANCE WILL MOVE ALONG A FRONT ALONG THE DOWNEAST COAST
TUESDAY NIGHT...WITH A COLD FRONT APPROACHING NORTHWEST MAINE
LATE. AN AREA OF RAIN WILL MOVE ACROSS THE REGION WITH THE
DISTURBANCE TUESDAY NIGHT. THIS AREA OF RAIN WILL MOVE EAST
OVERNIGHT...WITH PRECIPITATION TAPERING TO SHOWERS LATE. SHOWER
CHANCES WILL THEN BEGIN TO INCREASE ACROSS NORTHWESTERN AREAS
LATER TUESDAY NIGHT IN ADVANCE OF THE APPROACHING COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL CROSS THE REGION IN ADVANCE OF THE
COLD FRONT WEDNESDAY...THEN END IN THE WAKE OF THE COLD FRONT
THROUGH THE AFTERNOON. HIGH PRESSURE WILL BUILD EAST WEDNESDAY
NIGHT THEN CROSS THE REGION THURSDAY THROUGH THURSDAY NIGHT WITH
PARTLY CLOUDY/MOSTLY CLEAR SKIES. TEMPERATURES WILL BE AT NEAR
NORMAL...TO SLIGHTLY BELOW NORMAL...LEVELS WEDNESDAY THROUGH
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. A
WEAK HIGH PRESSURE RIDGE WILL BE BUILT OVER THE AREA AT THE START
OF THE PERIOD. THERE WILL BE A LOW PRESSURE SYSTEM ALONG THE
COAST OF VA...A SECOND LOW PRESSURE SYSTEM OVER LAKE SUPERIOR. FRI
EVNG THE LOW ALONG THE COAST OF VA WILL MOVE NORTH. THE GFS AND
ECMWF DIFFER ON THE SOLUTION. THE ECMWF BRINGS THE LOW NORTH ALONG
THE COAST CENTERED AROUND LONG ISLAND..WITH A WARM FRONT EXTENDING
NE INTO THE GULF OF MAINE. THE GFS MOVES THE LOW NORTH BUT KEEPS
IT WELL EAST OF THE COAST...AND MAINTAINS THE HIGH PRESSURE RIDGE
ACROSS THE AREA. THESE DIFFERENCE CONTINUE INTO SAT MRNG. THE
ECMWF MOVES THE LOW NORTH TO BAR HARBOR...EXTENDS THE WARM FRONT
EAST INTO NEW BRUNSWICK. THE GFS CONTINUES TO MAINTAIN THE HIGH
PRESSURE RIDGE. BOTH MODELS DEEPEN THE LOW OVER LAKE SUPERIOR AND
MOVE IT NORTH TO JAMES BAY. BOTH MODELS ALSO SHOW SEVERAL
SECONDARY LOWS ALONG A BOUNDARY EXTENDING THROUGH THE GREAT
LAKES...THROUGH THE CENTRAL US...TO TEXAS. BY SUN MRNG BOTH MODELS
MOVE THE RIDGE EAST OF THE AREA...AS THE FRONT PUSHES INTO VT/NH.
BY SUN EVNG THE GFS MOVES THE FRONT INTO WRN MAINE...THE ECMWF
INTO NH. MON MRNG THE GFS TO ERN ME...ECMWF WRN ME. MON EVNG THE
GFS MOVES THE FRONT THROUGH...THE ECMWF TO ERN ME. BY THE END OF
THE PERIOD THE GFS INDICATES THAT MAINE WILL BE INFLUENCED BY WRAP
AROUND PRECIP...THE ECMWF MAINTAINS THE LOW OVER MAINE.
LOADED MODEL BLEND FOR MAX/MIN TEMP...WND/SKY/POP. ADDED 15
PERCENT TO WINDS FOR GUSTS OVER LAND...20 PERCENT OVER COASTAL
WATERS.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR CONDITIONS THIS EVENING ARE EXPECTED TO LOWER TO
IFR DOWNEAST LATE TONIGHT AND IFR TO MVFR ACROSS THE NORTH TUESDAY
MORNING. IFR CONDITIONS IN LOW CLOUDS ARE EXPECTED ON TUESDAY.
SHORT TERM: MVFR/IFR...WITH OCCASIONAL LIFR...CONDITIONS ARE
EXPECTED ACROSS THE REGION TUESDAY NIGHT INTO WEDNESDAY.
CONDITIONS WILL BEGIN TO IMPROVE LATER WEDNESDAY IN THE WAKE OF
THE COLD FRONT. GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS THE
REGION WEDNESDAY NIGHT THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA THROUGH
TUESDAY. HUMID AIR LIFTING NORTH WITH THE WARM FRONT WILL LIKELY
RESULT IN SOME FOG OVER THE WATERS LATE TONIGHT INTO TUESDAY.
SHORT TERM: SMALL CRAFT ADVISORY LEVEL SEAS ARE POSSIBLE WEDNESDAY
INTO WEDNESDAY NIGHT. OTHERWISE...WINDS/SEAS ARE EXPECTED TO BE
BELOW SMALL CRAFT ADVISORY LEVELS TUESDAY NIGHT THROUGH THURSDAY
NIGHT. VISIBILITIES WILL BE REDUCED IN RAIN AND FOG TUESDAY NIGHT
AND WEDNESDAY...WITH A CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER/HASTINGS
SHORT TERM...NORCROSS
LONG TERM...NORTON
AVIATION...BLOOMER/HASTINGS/NORCROSS
MARINE...BLOOMER/HASTINGS/NORCROSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 PM EDT WED JUL 24 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW NW FLOW INTO THE UPPER
GREAT LAKES...RESULTING FROM A RIDGE OVER WRN N AMERICA AND A TROF
OVER ERN NAMERICA. WEAK REMNANT OF SHORTWAVE THAT WAS OVER CNTRL
SASKATCHEWAN 24HRS AGO IS NOW PASSING OVER THE UPPER GREAT LAKES.
12Z KINL SOUNDING SHOWED A CAP AROUND 12.5KFT MSL...AND LATEST SPC
ANALYSIS SHOWS MUCAPE ONLY 100-200J/KG. BOTH DO NOT SUPPORT MUCH OF
A SHRA POTENTIAL. KMQT RADAR IS OUT OF SERVICE UNTIL LATE THU
MORNING/EARLY AFTN WHILE PARTS ARE IN TRANSIT...SO NOT CERTAIN IF
THERE HAS BEEN ANY SHRA OVER W OR CNTRL UPPER MI THIS AFTN. HOWEVER...
KGRB/KDLH RADARS HAVE INDICATED A FEW RETURNS...SO THERE MIGHT BE A
FEW SPRINKLES OR PERHAPS A -SHRA OUT THERE. UPSTREAM...ISOLD/SCT
CONVECTION IS NOTED NW AND N OF LAKE SUPERIOR...TYPICAL FOR
SUMMERTIME NW FLOW. FARTHER UPSTREAM...A LARGER SCALE TROF EXTENDING
FROM WRN HUDSON BAY TO NRN ALBERTA IS DROPPING S. THIS FEATURE WILL
BE THE PLAYER IN THE WEATHER HERE THU THRU SAT.
WITH LOSS OF DAYTIME HEATING...ANY ONGOING ISOLD SHRA/SPRINKLES
WILL DISSIPATE THIS EVENING. HOWEVER...ANOTHER SUBTLE SHORTWAVE IS
NOTED OVER SRN MANITOBA...AND IT IS SUPPORTING MUCH OF THE ISOLD/SCT
SHRA/TSRA ACTIVITY OVER SE MANITOBA INTO ADJACENT NRN ONTARIO/NRN
MN. THIS WAVE COMBINED WITH WAA REGIME COULD HELP MAINTAIN A FEW
SHRA/POSSIBLE TSRA THRU THE NIGHTTIME HRS AS IT CONTINUES TO THE SE.
SO...WILL INCLUDE SCHC POPS OVER THE W LATE IN THE NIGHT.
ON THU...AFOREMENTIONED LARGER SCALE TROF WILL PIVOT SE INTO NRN
ONTARIO AND SRN MANITOBA/SRN SASKATCHEWAN. ASSOCIATED BROAD...BUT
ORGANIZING SFC LOW WILL REACH VCNTY OF WRN LAKE SUPERIOR LATE IN THE
DAY. THERE MAY BE A FEW SHRA/PERHAPS TSRA DURING THE MORNING HRS
WITHIN WAA REGIME. OTHERWISE...BUILDING INSTABILITY IN THE AFTN AND
APPROACHING HEIGHT FALLS AS LARGER SCALE TROF SWINGS CLOSER WILL
LIKELY RESULT IN INCREASING COVERAGE OF SHRA/TSRA DURING THE DAY.
WITH NAM/GFS MLCAPE INCREASING TO UPWARDS OF 1000J/KG AND DEEP LAYER
SHEAR PROGGED AT 30-40KT...EXPECT SOME STORM ORGANIZATION...LEADING
TO THE POSSIBILITY OF A FEW STRONGER STORMS. IF THERE IS SUFFICIENT
DAYTIME HEATING TO RAISE CAPE TO THE MODEL VALUES...THEN THERE WILL
BE THE POTENTIAL FOR ISOLD SVR STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
A LINE OF SHOWERS AND THUNDERSTORMS WILL BE MOVING ACROSS THE AREA
AT THE START OF THE LONG TERM PERIOD. THIS IS DUE TO A TROUGH
DIGGING SOUTHEAST INTO NORTHERN MINNESOTA AND PRODUCING A
BROAD/WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. THE GENERAL
TREND OVER THE LAST COUPLE OF DAYS IS FOR THE SHORTWAVE AND LOW
TRACK TO BE FARTHER SOUTH...WHICH INFLUENCES THE WEATHER FOR THE
WEEKEND. BEFORE THAT...THE SHOWERS AND THUNDERSTORMS WILL BE MOVING
EAST ACROSS CENTRAL AND EASTERN UPPER MICHIGAN DURING THE EVENING
AND INTO THE OVERNIGHT HOURS. WITH LIMITED INSTABILITY AND LOSS
OF DIURNAL HEATING...THINK THE SEVERE POTENTIAL IS MARGINAL EVEN
THOUGH 0-6KM SHEAR VALUES ARE IN THE 35-40KT RANGE. AS THE FIRST
WAVE OF PRECIPITATION MOVES EAST...THINK THERE WILL BE LINGERING
CLOUDS AND A FEW RAIN SHOWERS OVER THE WEST THROUGH THE NIGHT WITH
THE BROAD/WEAK LOW MOVING OVER THE WESTERN U.P.
SECOND SHORTWAVE WILL ARRIVE ON FRIDAY (WEST MORNING AND EAST
AFTERNOON) AND KICK OFF ANOTHER PERIOD OF NUMEROUS SHOWERS. SINCE
THE LOW WILL HAVE SHIFTED TOWARDS CENTRAL UPPER MICHIGAN...ANY
INSTABILITY (MUCAPE VALUES UNDER 750 J/KG) WILL BE ALIGNED ALONG AND
EAST OF THAT LOCATIONS...SO WILL CONFINE THE BEST THUNDER CHANCES
THERE. SINCE 0-6KM SHEAR VALUES ARE ONLY 15-20KTS...HEAVY RAIN
WOULD BE THE MAIN THREAT.
THIS SECOND SHORTWAVE WILL ALSO CAUSE THE TROUGH TO WRAP UP INTO A
CLOSED LOW OVER THE UPPER GREAT LAKES ON FRIDAY NIGHT AND REMAIN
IN THE AREA INTO SUNDAY MORNING. THIS WILL LEAD TO WEATHER MORE
LIKE LATE SEPTEMBER INSTEAD OF LATE JULY. DURING THAT
TIME...EMBEDDED WAVES AND INCREASED MOISTURE WILL LEAD TO CLOUDY
CONDITIONS...PERIODS OF RAIN (ESPECIALLY OVER THE NORTH
HALF)...GUSTY NORTHWEST WINDS (FRIDAY NIGHT INTO
SATURDAY EVENING)...AND TEMPERATURES WELL BELOW NORMAL (50S AND
LOW 60S SATURDAY). TEMPERATURES ON SATURDAY MAY BE SOMETHING TO
KEEP AN EYE ON...SINCE SOME OF THE RAW MODELS ARE INDICATING HIGHS
IN THE UPPER 40S OR LOW 50S OVER THE NORTHWEST HALF OF THE U.P.
LOOKING AT SOME PAST HIGHS...THE RECORD COLDEST JULY HIGH
TEMPERATURES FOR MANY SITES ARE IN THAT RANGE (NWS MQT 51 IN
2004/1992...CMX 49 IN 1992...IRONWOOD 52 IN 2009/1997).
MOST LIKELY PERIOD FOR DRIER WEATHER WILL BE SUNDAY AFTERNOON INTO
MONDAY AFTERNOON...AS THE UPPER LOW SHIFTS NORTHEAST INTO QUEBEC
AND WEAK HIGH PRESSURE SLIDES ACROSS THE AREA. MODELS CONTINUES TO
STRUGGLE ON THAT TIMING WITH THE SPEED OF THE UPPER LOW
EXITING...WHICH IS USUALLY THE CASE. ONCE THE LOW SHIFTS
NORTHEAST...A SERIES OF SHORTWAVES LOOK TO MOVE ACROSS THE UPPER
GREAT LAKES MONDAY NIGHT INTO TUESDAY NIGHT. WILL CONTINUE TO
MENTION LOW END CHANCE POPS FOR THESE SHORTWAVES MOVING THROUGH.
AFTER THE COOL WEEKEND...TEMPERATURES SHOULD REBOUND TO MORE NORMAL
VALUES FOR THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 725 PM EDT WED JUL 24 2013
ALTHOUGH THERE COULD A BRIEF -SHRA AT SAW EARLY THIS EVNG...EXPECT
VFR CONDITIONS/DRY WX THRU TNGT BEFORE APPROACH OF A LO PRES TROF
BRINGS THE THREAT OF MORE SHRA BEGINNING ON THU MRNG. A BETTER CHC
FOR THE SHRA AND SOME TS WL BE AFT 18Z...WHEN DAYTIME HEATING WL
INCRS INSTABILITY. WITH MORE OPPORTUNITY FOR SOME COOLING OFF LK
SUP...THE CHC FOR TS IS LOWER AT CMX. SINCE THE LLVLS WL BE FAIRLY
DRY...VFR CONDITIONS SHOULD PREVAIL ON THU...BUT LOWER CONDITIONS
COULD OCCUR UNDER THE HEAVIER SHRA/TS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT WED JUL 24 2013
WITH HIGH PRES DEPARTING TO THE E AND LOW PRES APPROACHING FROM THE
NW...S WINDS WILL BE THE RULE TONIGHT AND THU...THOUGH SPEEDS SHOULD
REMAIN UNDER 20KT. IF THERE ARE ANY STRONGER WINDS...THEY WILL OCCUR
OVER ERN LAKE SUPERIOR THU AFTN/EVENING. ONCE THE LOW MOVES E OF
LAKE SUPERIOR...WINDS WILL SHIFT AROUND TO THE N TO NW FRI. GIVEN
THE INCOMING CHILLY AIR MASS FOR THIS TIME OF YEAR...IT LOOKS LIKE
THERE WILL BE A PERIOD OF 15-25KT WINDS OVER MAINLY CNTRL LAKE
SUPERIOR FRI NIGHT INTO SAT. HOWEVER...IT`S NOT OUT OF THE QUESTION
THAT WINDS COULD BE HIGHER DUE TO THE UNSEASONABLY COOL AIR MASS
PUSHING OVER THE AREA. WINDS WILL DIMINISH SUN/MON AS HIGH PRES
BUILDS INTO THE WRN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT TUE JUL 23 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE OVER
JAMES BAY. PRES GRADIENT BTWN ITS ASSOCIATED SFC LOW E OF JAMES BAY
AND SFC HIGH PRES OVER NW MN/ERN DAKOTAS HAS RESULTED IN BREEZY N/NW
WINDS TODAY AND MUCH COOLER CONDITIONS COMPARED TO YESTERDAY. PER
WATER VAPOR IMAGERY...IN THE NW FLOW UPSTREAM...THERE ARE A COUPLE
OF SHORTWAVES EVIDENT...ONE OVER ERN MT/WRN ND AND ANOTHER OVER
CNTRL SASKATCHEWAN. THE NRN WAVE MAY BE A FACTOR IN THE WEATHER HERE
ON WED.
A QUIET...COOL NIGHT IS IN STORE TONIGHT AS SFC HIGH PRES SETTLES SE
INTO WI...BRINGING DIMINISHING WINDS FROM W TO E. WITH DECREASING
WINDS...CLEAR SKIES AND PRECIPITABLE WATER 50-70PCT OF NORMAL...
EXPECT A DECENT RADIATIONAL COOLING NIGHT...ESPECIALLY OVER W AND SW
UPPER MI AS WINDS SHOULD DIMINISH TO CALM IN THAT AREA...BEING
CLOSER TO SFC HIGH PRES CENTER. WILL CONTINUE TO SHOW LOWEST TEMPS
IN THAT AREA (40 TO THE LWR 40S). OTHERWISE...MIN TEMPS SHOULD BE IN
THE 40S IN THE INTERIOR TO MOSTLY AROUND 50F ALONG THE GREAT LAKES.
AFTER A QUIET NIGHT...ATTENTION ON WED SHIFTS TO POSSIBLE AFTN
CONVECTION. SUMMERTIME WNW/NW FLOW IS OFTEN A FAVORABLE PATTERN
FOR ISOLD/SCT AFTN CONVECTION AS EVEN THE MOST SUBTLE SHORTWAVES CAN
SPARK SOME PCPN. IF THERE WASN`T A SHORTWAVE PRESENT UPSTREAM...
WOULD HAVE DROPPED PCPN MENTION ON WED...BUT SINCE THERE IS AN
OBVIOUS WAVE CURRENTLY UPSTREAM IN CNTRL SASKATCHEWAN...IT LOOKS
LIKE THERE WILL PROBABLY BE SOME ISOLD AFTN CONVECTION AS THE WAVE
DROPS SE INTO THE AREA. WILL CONTINUE TO HIGHLIGHT SCHC POPS OVER
MAINLY THE INTERIOR W AND CNTRL WHERE THE LIMITED INSTABILITY IS
BEST. NAM/GFS MLCAPES ARE ONLY AS HIGH AS 200-300J/KG DURING THE MID
AFTN...SO THUNDER POTENTIAL APPEARS MINIMAL. HOWEVER...CANADIAN
RADARS CURRENTLY SHOW DECENT RETURNS IN THE VCNTY OF SHORTWAVE IN
SASKATCHEWAN AND SATELLITE IMAGERY SUGGESTS SOME DECENT
CONVECTION...SO THERE MAY BE SOME THUNDER OCCURRING WITH THE WAVE
THIS AFTN. FOR NOW...WILL LEAVE THUNDER MENTION IN THE FCST FOR WED
AND LET LATER SHIFTS REASSESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A SHORTWAVE
DROPPING SOUTH-SOUTHEAST THROUGH CENTRAL CANADA ON WEDNESDAY AND
WEDNESDAY NIGHT...WHICH THEN MOVES INTO CENTRAL ONTARIO BY THURSDAY
NIGHT AND CLOSES OFF. THIS UPPER LOW WILL REMAIN IN CENTRAL ONTARIO
INTO SUNDAY BEFORE SHIFTING NORTHEAST INTO ONTARIO FOR THE START OF
THE WORK WEEK.
WEDNESDAY NIGHT WILL BE RELATIVELY QUIET AS ANY DIURNAL CLOUDS AND
SHOWERS DIMINISH FAIRLY QUICKLY DURING THE EVENING. THEN...EXPECT
MID-HIGH CLOUDS TO BE ON THE INCREASE THROUGH THE NIGHT AS THE
SHORTWAVE MOVES INTO SOUTHWEST ONTARIO AND AN ASSOCIATED 1008MB LOW
DEVELOPS EAST OF LAKE WINNIPEG AND SLIDES EAST. AS THE SHORTWAVE
AND SURFACE LOW CONTINUE TO THE EAST-SOUTHEAST ON LATE WEDNESDAY
NIGHT AND THURSDAY...AN ASSOCIATED COLD FRONT WILL SLIDE INTO
WESTERN UPPER MICHIGAN DURING THE AFTERNOON. THAT WILL BE THE AREA
WITH THE BEST OPPORTUNITY FOR SHOWERS/THUNDERSTORMS ON THURSDAY
AFTERNOON AND WILL CONTINUE TO HIGHLIGHT INCREASING POPS TO LIKELY
VALUES DURING THE AFTERNOON.
INSTABILITY LOOKS FAIRLY LIMITED OVER MOST OF THE AREA...WITH MLCAPE
VALUES AROUND 500 J/KG ALTHOUGH MUCAPE VALUES DO APPROACH 1500
J/KG IN SOME MODELS OVER THE WEST AND 09Z SREF ONLY INDICATES A 20
PERCENT CHANCE 1000 J/KG IS REACHED. CAPE IS FAIRLY TALL/SKINNY AS
SEEN IN NCAPE VALUES IN THE 0.05-0.1 RANGE. AS FOR SHEAR...0-6KM AND
EFFECTIVE VALUES ARE ALSO MARGINAL (AROUND 30-35KTS)...ALTHOUGH
THERE IS SOME LOW LEVEL VEERING TO THE WIND. THE STRENGTH OF THE
SHORTWAVE MAY HELP OVERCOME THE MARGINAL INSTABILITY/SHEAR...BUT
THINK THE STORMS WILL PRIMARILY BE SUB SEVERE. THEY WILL LIKELY BE
THE STRONGEST OVER THE FAR WEST...WHERE IT IS CLOSER TO THE
SYNOPTIC AND FRONTAL FORCING. NAM/GFS STORM MOTION VECTORS INDICATE
THE STORMS WILL MOVE FAIRLY QUICKLY TO THE EAST (AROUND 40KTS) AND
HAVE FOLLOWED SUIT WITH THE POPS. BUT THE OVERALL TREND WITH THE
FRONT HAS BEEN SLOWER...WITH IT NOW EXITING EASTERN UPPER MICHIGAN
BETWEEN 09Z-18Z FRIDAY.
MODELS DIFFER SOMEWHAT WITH THE POSITION OF THE SURFACE/UPPER
LOW...BUT THE GENERAL IDEA OF COOL...CYCLONIC FLOW AFFECTING THE
UPPER GREAT LAKES FRIDAY THROUGH SUNDAY MORNING SEEMS REASONABLE.
ANOTHER SHORTWAVE ROTATES AROUND THE UPPER LOW ON FRIDAY AND
PRECIPITATION CHANCES DEPEND ON HOW QUICKLY THE FRONT MOVES
EAST...THE DRY SLOT BEHIND IT...AND ADDITIONAL MOISTURE DROPPING
SOUTHEAST ACROSS WESTERN LAKE SUPERIOR. THESE FEATURES ARE STILL
VARIABLE IN THE MODELS...BUT THE MORNING LOOKS TO HAVE THE BEST
OPPORTUNITY FOR LINGERING SHOWERS OVER THE SE U.P. TRIED TO SHOW A
LITTLE MORE TIMING ON POPS FOR FRIDAY BUT CONFIDENCE WASN/T HIGH
ENOUGH TO SHOW DRY PERIODS UNDER THE DRY SLOT.
WITH THE MOISTURE WRAPPING AROUND THE UPPER LOW FRIDAY
NIGHT INTO SATURDAY NIGHT...EXPECT THERE TO BE PERIODS OF
CLOUDS...ESPECIALLY FRIDAY NIGHT INTO SATURDAY. MOST OF THE MOISTURE
IS FAIRLY SHALLOW...BUT THERE MAY BE ENOUGH AROUND FOR SOME LIGHT
RAIN SHOWERS/DRIZZLE ON FRIDAY NIGHT INTO SATURDAY AND WILL RETAIN
SLIGHT CHANCE POPS. TEMPERATURES THIS WEEKEND WILL VERY COOL FOR
LATE JULY STANDARDS...WITH LOW 60S ON SATURDAY (10-15 DEGREES BELOW
NORMAL) AND MID-UPPER 60S FOR SUNDAY.
THE UPPER LOW SHIFTS AWAY ON SUNDAY AFTERNOON AND THE AREA WILL BE
BACK UNDER WEST-NORTHWEST FLOW ALOFT. BOTH GFS/ECMWF ARE SHOWING A
SHORTWAVE AND ASSOCIATED WARM FRONT MOVING TOWARDS THE AREA
SOMETIME MONDAY TO TUESDAY AND HAVE SLOWLY BROUGHT POPS UP TO
CHANCES BY TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE JUL 23 2013
LINGERING MVFR CIGS AT KSAW WILL LIFT TO VFR OVER THE NEXT HR OR TWO
AS DAYTIME HEATING AND INFLUX OF DRIER AIR WORK TO RAISE CLOUD
BASES. OTHERWISE...WITH HIGH PRES BUILDING INTO THE AREA...EXPECT
VFR CONDITIONS TO DOMINATE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
IN FACT...LINGERING STRATOCU WILL SCATTER OUT/DISSIPATE FROM NW TO
SE THRU THE AFTN...LEAVING CLR/MCLR SKIES BY SUNSET. GUSTY WINDS AT
KCMX/KSAW WILL ALSO SLOWLY SUBSIDE THRU THE AFTN AS PRES GRADIENT
WEAKENS WITH HIGH PRES MOVING CLOSER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT TUE JUL 23 2013
AFTER A PERIOD OF STRONG WINDS TODAY ACROSS LAKE SUPERIOR IN THE
WAKE OF A COLD FRONT...LIGHTER WINDS UNDER 20KT WILL BE THE RULE
TONIGHT INTO WED AS HIGH PRES BUILDS INTO THE WRN GREAT LAKES. AS
THE HIGH SHIFTS E AND LOW PRES APPROACHES FROM THE NW...WINDS WILL
BECOME SOUTHERLY WED NIGHT/THU...BUT REMAIN UNDER 20KT. EVEN AFTER
THE LOW PASSES THRU THE UPPER GREAT LAKES/NRN ONTARIO...WINDS WILL
PROBABLY REMAIN 20KT OR LESS LATE WEEK AND THRU THE WEEKEND.
HOWEVER...WILL NEED TO WATCH FOR STRONGER SOUTHERLY WINDS THU NIGHT
JUST AHEAD OF THE LOW AND ASSOCIATED COLD FRONT AND THEN LATER FRI
INTO SAT BEHIND COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1137 AM EDT TUE JUL 23 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 AM EDT TUE JUL 23 2013
A COLD FRONT MOVING THROUGH WESTERN LOWER MICHIGAN THIS MORNING WILL
BRING A FEW SHOWERS AND STORMS THAT WILL END TOWARD MID DAY. BEHIND
THE FRONT MUCH MORE COMFORTABLE HUMIDITY LEVELS WILL MOVE IN THIS
AFTERNOON AND PREVAIL THROUGH MID WEEK. WEDNESDAY AND THURSDAY WILL
SEE HIGH TEMPERATURES FROM 75 TO 80 WITH MOSTLY SUNNY SKIES.
THE NEXT CHANCE OF RAIN IS EXPECTED TO ARRIVE FOR FRIDAY AND
SATURDAY. TEMPERATURES INTO THE WEEKEND ARE EXPECTED TO REMAIN
SLIGHTLY BELOW NORMAL...MAINLY IN THE 70S.
&&
.UPDATE...
ISSUED AT 1137 AM EDT TUE JUL 23 2013
QUICK TURNAROUND FROM THE PREVIOUS UPDATE. SHOWERS HAVE DEVELOPED
ALONG THE FRONT JUST SOUTH AND NORTHEAST OF GRAND RAPIDS. THIS
ACTUALLY WAS WELL ADVERTISED BY THE LAST FEW RUNS OF THE HRRR...
BUT SADLY WAS DISCOUNTED. HAVE UPDATED THE GRIDS AND FORECASTS
USING RECENT HRRR GUIDANCE...WHICH MOVES PRECIPITATION SOUTHEAST
OUT OF THE AREA THIS AFTERNOON. RAP FORECAST SOUNDINGS SHOW
SUFFICIENT INSTABILITY FOR THUNDERSTORMS /MLCAPE 1000 J PER KG
EXTENDING TO ABOVE THE -30C LEVEL/ EXISTS ALONG AND AHEAD OF THE
FRONT.
UPDATE ISSUED AT 1026 AM EDT TUE JUL 23 2013
HAVE REMOVED MENTION OF PRECIPITATION FOR THE REST OF THE DAY
BASED ON RADAR TRENDS. VISIBLE SATELLITE IMAGERY AND SHORT RANGE
MODEL GUIDANCE SUGGEST THAT WE WILL SEE A FEW HOURS OF CLOUDINESS
BEHIND THE COLD FRONT...WHICH AT 10 AM WAS LOCATED JUST SOUTH OF A
MOUNT PLEASANT TO MUSKEGON LINE. THIS FRONT IS EXPECTED TO MOVE
SOUTH OUT OF LOWER MICHIGAN THIS AFTERNOON. TEMPERATURES ARE A
LITTLE TRICKY...BUT SHOULD PEAK EARLY THIS AFTERNOON NEAR OR JUST
BEHIND THE FRONT AS IT PROGRESSES SOUTH.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM EDT TUE JUL 23 2013
A COLD FRONT WILL CONTINUE TO SLIDE ACROSS THE CWA THIS MORNING. A
DRY AND COOL AIR MASS WILL FILTER IN THROUGH THE AFTERNOON BEHIND
THE FRONT. THE COLD ADVECTION WILL BRING INCREASINGLY DANGEROUS
WAVE ACTION ON THE LAKE AND A BEACH HAZARDS STATEMENT HAS BEEN
POSTED. MORE ON THIS IN THE MARINE SECTION. OTHERWISE THERE IS AN
OUTSIDE CHANCE OF A FEW SHOWERS AGAIN LATE WEDNESDAY NIGHT INTO
THURSDAY ACROSS THE NORTHERN CWA.
THE COLD FRONT EXTENDED FROM NEAR THE STRAITS TO MADISON WI EARLY
THIS MORNING. IT WAS PRESSING STEADILY SE AND SHOULD BE NEAR A
MOP-GRR-LWA LINE BY 12Z THIS MORNING. AREAS NORTHWEST OF THIS LINE
SHOULD REMAIN DRY AFTER 12Z...AND HAVE DROPPED POPS. SE OF THIS
LINE WILL CARRY LOW CHC POPS AS ANY LEFTOVER PCPN SLOWLY WEAKENS
WITH THE LACK OF ANY SUSTAINABLE JET AND DIMINISHING INSTABILITY.
THE FRONT SHOULD CLEAR EAST OF THE ENTIRE CWA AROUND NOON TIME WHEN
ALL PCPN SHOULD BE TO OUR EAST. DEW POINTS WILL FALL FROM THE MID
60S EARLY THIS MORNING TO AROUND 50 BY EVENING. CERTAINLY A
REFRESHING AIR MASS FOR MID SUMMER.
HIGH PRESSURE FILLS IN FOR THE REST OF THE SHORT TERM INTO
THURSDAY. WARM DAYS AND COOL NIGHT WILL BE SEEN. LOWS FROM 50 TO
55 AND HIGHS IN THE MID AND UPPER 70S ARE EXPECTED. ONE BRIEF
GLITCH...THE MODELS ARE ON THE SAME PAGE WITH BRINGING A WEAK SHORT
WAVE THROUGH LOWER MI THURSDAY MORNING. SOME WEAK LIFT AND SOME
MOISTURE POOLS NEAR THIS WAVE...ESPECIALLY ACROSS CENTRAL LOWER.
HAVE ADDED A 20 POP FOR A THURSDAY MORNING SHOWER NORTH OF HIGHWAY
20.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 356 AM EDT TUE JUL 23 2013
WE CONTINUE TO WATCH FOR A STRONG COLD FRONT TO COME THROUGH THE
AREA FRIDAY NIGHT WITH STRONG THUNDERSTORMS POSSIBLE. BEHIND THE
COLD FRONT WE MAY SEE THE COOLEST TEMPERATURES THIS AREA HAS SEEN
SINCE THE MIDDLE OF JUNE.
THE LONG WAVE PATTERN HAS SHIFTED IN THAT THE LONG WAVE TROUGH IS NOW
OVER EASTERN CANADA AND THE EASTERN UNITED STATES. THIS PATTERN
SEEMS STABLE INTO NEXT WEEK. THAT BEING SO AN UPPER AIR SYSTEM
CURRENTLY OVER CENTRAL CANADA INTO WESTERN HUDSON BAY... ROTATES
SOUTHEAST INTO THE GREAT LAKES TOWARD FRIDAY. A CLOSED UPPER LOW
DEVELOPS WITH THE SYSTEM BY FRIDAY AFTERNOON AND THAT MOVES EAST
JUST NORTH OF LAKE SUPERIOR INTO SUNDAY. THE GFS...ECMWF AND
CANADIAN MODELS ARE ALL RATHER SIMILAR WITH THIS OUTCOME AND HAVE
HAD SIMILAR SOLUTIONS OVER THE PAST FEW RUNS (SINCE 22/00Z). SO THAT
LENDS CONFIDENCE TO THE FORECAST.
THERE IS 90 KNOT JET STREAK THAT ROTATES INTO THE WESTERN GREAT
LAKES FRIDAY EVENING WITH THAT DEEPENING UPPER LOW. THE LEFT
ENTRANCE REGION OF THAT JET STREAK CROSSES THE INTERSTATE 94 AREA
AROUND MIDNIGHT FRIDAY NIGHT. AS TYPICAL FOR THIS AREA LATELY... THE
LOW LEVEL JET SPEED MAX CROSSES LAKE HURON FRIDAY EVENING PUTTING
SOUTHWEST MICHIGAN IN THE SPEED DIVERGENCE AREA OF THE LOW LEVEL
JET... NOT SO GOOD FOR SEVERE STORMS. SO EVEN THROUGH THERE WOULD BE
SOME DECENT MID LEVEL LIFT... ELEVATED CAPE AND 40 TO 60 KNOTS OF
DEEP LAYER SHEAR... THAT THOSE STORMS WOULD BE COMING THROUGH
OVERNIGHT WITH THE LOW LEVEL JET NOT IN AN OPTIMUM POSITION TELLS ME
THIS WILL BE ANOTHER EVENT WITH A MORE GENERIC NIGHT TIME
THUNDERSTORMS THAN SEVERE STORMS.
ONCE THE FRONT COMES THROUGH 850 MB TEMPS FALL TO NEAR 5C BY SUNDAY
MORNING. THAT IS 15-20C BELOW THE LAKE TEMPERATURE... WHICH BY THE
WAY IS AROUND 2 STANDARD DEVIATIONS FROM NORMAL (850 MB TEMP) AND
WOULD BE COLD ENOUGH FOR LAKE EFFECT RAIN SHOWERS IF THE LOW LEVEL
AIR IS MOIST ENOUGH (IT LIKELY WILL NOT BE MOIST ENOUGH). HOWEVER
WITH THE CLOSED UPPER LOW NORTH OF LAKE SUPERIOR THAT PUT SOUTHWEST
MICHIGAN FAR ENOUGH SOUTH FROM THE DEEP COLD AIR SO THAT WE WILL
LIKELY HAVE HIGH PRESSURE AND DRY AIR FROM SATURDAY AFTERNOON INTO
MONDAY. GIVEN HOW COLD THAT AIR IS IT WOULD SEEM THERE IS SOME
POTENTIAL FOR AFTERNOON HEATING CONVECTION AS THE COLDEST AIR MOVES
THROUGH ON SUNDAY. SO I PUT LOW CHANCE POP SUNDAY AFTERNOON INLAND
FOR THE POTENTIAL FOR SHALLOW CONVECTION DUE TO DESTABILIZATION FROM
AFTERNOON HEATING. MODEL SOUNDING SHOW A STRONG INVERSION AROUND 700
MB SO WHAT CONVECTION DOES DEVELOP SUNDAY AFTERNOON WILL HAVE TO BE
RATHER SHALLOW. MORE SPRINKLES THAN ANYTHING.
GIVEN THOSE 850 MB TEMPS SATURDAY INTO SUNDAY WE SHOULD HAVE HIGHS
ONLY IN THE LOWER TO MID 70S... QUIET THE CHANGE FROM LAST WEEK.
WE GET TO SEE THE COOLER SIDE OF SUMMER THIS COMING WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 749 AM EDT TUE JUL 23 2013
MVFR CONDITIONS ARE THE MAIN CONCERN THIS MORNING. A DECK OF
STRATUS CLOUDS WILL QUICKLY MOVE OVER THE AREA THROUGH MID MORNING. THIS
SHOULD EXIT EAST AND MAY MIX OUT WITH HEATING THIS AFTERNOON. VFR
CONDITIONS THEN SETTLE IN WITH THE FOCUS THEN BECOMING
WINDS...WITH GUSTY CONDITIONS LIKELY THROUGH LATE EVENING.
&&
.MARINE...
ISSUED AT 330 AM EDT TUE JUL 23 2013
NORTHERLY WINDS AND COLD ADVECTION WILL LEADING TO BUILDING WAVES
TODAY INTO THIS EVENING. THIS WILL RESULT IN HAZARDOUS BEACH
CONDITIONS AS WELL AS PRODUCE SMALL CRAFT ADVISORY CONDITIONS.
WAVES WILL BUILD BY MID MORNING...FIRST ACROSS THE POINTS REGION.
THEN AS THE FRONT CONTINUES TO MOVE SE HIGHER WAVES WILL BUILD DOWN
THE LENGTH OF THE LAKE BY MID DAY. THE PERSISTENT NORTHERLY FLOW
WILL CONTINUE TO BUILD WAVES RIGHT INTO THIS EVENING. MOST AREAS
WILL SEE 4 TO 6 FOOTERS. MAX WAVES SHOULD BUILD TO AROUND 8 FEET
NEAR AND SOUTH OF SOUTH HAVEN BY EARLY EVENING PRODUCING HIGH RISKS
TO ALL SWIMMERS. THESE CONDITIONS WILL PERSIST THROUGH TONIGHT.
AS HIGH PRESSURE BUILDS IN ON WEDNESDAY A DIMINISHING TREND IN THE
WINDS AND WAVES IS EXPECTED. MUCH QUIETER CONDITIONS ARE EXPECTED
FOR WED NIGHT AND THU.
&&
.HYDROLOGY...
ISSUED AT 330 AM EDT TUE JUL 23 2013
SCATTERED SHOWERS THIS MORNING SHOULD ONLY ACCOUNT FOR A QUARTER
INCH OR LESS FOR MOST RIVER BASIN. THIS WILL NOT CAUSE ANY HYDRO
ISSUES. BEYOND THIS MORNING DRY WEATHER IS EXPECTED THROUGH
THURSDAY NIGHT.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH WEDNESDAY EVENING FOR MIZ037-043-
050-056-064-071.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...JAM
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
132 AM EDT TUE JUL 23 2013
.SYNOPSIS...
ISSUED AT 402 PM EDT MON JUL 22 2013
CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE TONIGHT...IN ADVANCE
OF A COLD FRONT THAT WILL SWEEP ACROSS NORTHERN MICHIGAN EARLY
TUESDAY. HIGH PRESSURE BUILDS BACK INTO THE GREAT LAKES TUESDAY AND
HOLDS INTO THE LATTER HALF OF THE WORK WEEK...BRINGING COOLER AND
LESS HUMID WEATHER BACK TO NORTHERN MICHIGAN.
&&
.UPDATE...
ISSUED AT 132 AM EDT TUE JUL 23 2013
NICE TO SEE CONVECTION CAN ACTUALLY DEVELOP ACROSS THE CWA -
HAVEN`T SEEN THAT IN SOME TIME. NICE VORT TAIL IN ADVANCE OF THE
INCOMING SURFACE FRONT...COMBINED WITH A NARROW PLUME OF ELEVATED
CAPE (MUCAPE VALUES UP TOWARD 1000J/KG PER LATEST RUC ANALYSIS)
HAS WORKED TO HELP POP ADDITIONAL SHOWERS/STORMS OVER NORTHERN
LAKE MICHIGAN. ACTIVITY IS BEING HELD WELL IN CHECK (I.E. NO
SEVERE) BY ONLY MARGINAL INSTABILITY AND MARGINAL MID LEVEL LAPSE
RATES...BUT NONETHELESS IS PROVIDING SOME NEEDED RAIN FOR PARTS OF
NORTHWEST LOWER. THIS ACTIVITY WILL LIKELY STAY NORTH OF M-72 FOR
MUCH OF THE NIGHT...TIED TO THE BEST FRONTAL FORCING AND SUPPORT
ALOFT...BUT CAN`T COMPLETELY RULE OUT SOMETHING SOUTH OF
HERE...WHERE WILL MAINTAIN SOME SMALL POPS. OTHERWISE...NO BIG
CHANGES OTHER THAN TIMING OF PRECIP. TEMPS STILL WARM AT THIS
HOUR...BUT WILL FALL LATER TONIGHT AS THE FRONT PROGRESSES THROUGH
THE CWA.
UPDATE ISSUED AT 1038 PM EDT MON JUL 22 2013
SO...IS IT GOING TO RAIN IN NORTHERN LOWER AT ALL? SOME STRONGER
CELLS CONTINUE IN NE WI...BUT THEY HAVEN/T COALESCED INTO ANYTHING
REMOTELY ORGANIZED. THE ONE WELL-DEFINED OUTFLOW BOUNDARY IS
MOVING OFF THE WI SHORE DUE WEST OF MBL...AND FEEL REASONABLY
CONFIDENT THAT MANISTEE CO AND SOME SURROUNDING AREAS WILL AT
LEAST SEE SOME SHRA. THE REST OF THE ACTIVITY OVER THERE WANTS TO
PROPAGATE SE-WARD WITH TIME.
TSRA IN CENTRAL UPPER MI BRIEFLY WAS QUASI-LINEAR...BUT HAS
DEVOLVED INTO SOMETHING MORE DISORGANIZED. ONE CAN SEE A SE-WARD
MOVING FEATURE WITHIN THIS CLUSTER...WHICH APPEARS TO BE THE
ACTUAL COLD FRONT. THERE IS SOMETHING LIKE 25KT OF SW/240 FLOW
NOT FAR OFF THE DECK...TO HELP CARRY THIS ALONG AS IT MOVES E OR
SE. BUT...THERE IS UPSTREAM CONVECTION ALONG THAT FETCH...SO SOME
OF OUR POTENTIAL INFLOW IS BEING STOLEN.
LIKELY TO CATEGORICAL POPS STILL CLEARLY IN ORDER IN EASTERN
UPPER. WILL ALSO KEEP POPS HIGH IN THE VERY TIP OF THE
MITT...WHERE THE COLD LAKE GETS NARROWER AND WILL ALLOW FOR SOME
SE-WARD PROPAGATION. MANISTEE AREA WILL HAS MENTIONED LIKELY GET
RAINDROPS...THOUGH THUNDER IS LESS CERTAIN. IN BETWEEN...WILL
LOWER POPS IN THE BULK OF NORTHERN LOWER TO CHANCY.
UPSTREAM CONVECTION CLEARLY ALREADY ENCOUNTERING DWINDLING
INSTABILITY. NEVER SAY NEVER WHEN IT COMES TO MAYBE SEEING AN
ISOLATED SVR...BUT THAT THREAT CERTAINLY LOOKS MINIMAL.
ONLY MINOR CHANGES TO TEMPS AND OTHER FORECAST ELEMENTS.
UPDATE ISSUED AT 831 PM EDT MON JUL 22 2013
A FEW SPRINKLES CONTINUE TO MOVE THRU NORTHERN LOWER MI...AS
HEIGHTS ALOFT JUST BEGIN TO FALL AND MID-LEVEL LAPSE RATES START
TO STEEPEN. LOOKING AT THE 00Z APX OBSERVED SOUNDING...WITH 1K
J/KG OF UNCAPPED SBCAPE...IT IS SOMEWHAT DIFFICULT TO SEE WHY
THESE AREN/T BEING MORE AMBITIOUS. A COUPLE OF WEAK SHRA HAVE ALSO
DEVELOPED IN THE NEWBERRY AREA...AHEAD OF THE MAIN AXIS OF
SHRA/TSRA FROM CENTRAL UPPER MI BACK INTO IOWA.
HAVE SLOWED DOWN THE ARRIVAL OF HIGHER POPS FOR A FEW HOURS.
FIDDLED WITH SHORT-TERM POP/SKY COVER GRIDS AS WELL.
UPDATE ISSUED AT 537 PM EDT MON JUL 22 2013
HAVE REDUCED EARLY EVENING POPS IN MOST OF NORTHERN LOWER...WHERE
CONVECTION IS GENERALLY REFUSING TO FIRE.
HOWEVER...IT WILL BE INTERESTING TO SEE IF AN INCOMING MID-LEVEL
MOIST BAND...SEEN ON RADAR FROM BEAVER ISL INTO EASTERN
UPPER...CAN INTERACT WITH MARGINAL OVERLAND INSTABILITY OVER FAR
NORTHERN LOWER. HAVE ADDED/INCREASED POPS OVER FAR NORTHERN
LOWER...ESPECIALLY FROM INDIAN RVR/CHEBOYGAN EAST TO APN...WHERE
A PRE-EXISTING CU FIELD EXISTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON JUL 22 2013
EARLY AFTERNOON SURFACE ANALYSIS SHOWS A 998MB LOW OVER NORTHWEST
ONTARIO WITH A TRAILING COLD FRONT MOVING INTO FAR WESTERN LAKE
SUPERIOR/WESTERN UPPER/NORTHWEST WISCONSIN. SURFACE LOW TRACKING
TOWARD A 3MB/3H PRESSURE FALL CENTER DIRECTLY TO ITS EAST...KEEPING
IT NORTH OF LAKE SUPERIOR. SURFACE LOW SUPPORTED BY A SHORT WAVE
TROUGH ALSO MOVING THROUGH NORTHERN ONTARIO...WITH WATER VAPOR
IMAGERY HINTING AT ANOTHER VORTICITY CENTER AT THE TAIL END OF THIS
WAVE OVER SOUTHERN MINNESOTA/NORTHERN IOWA. NICE CU FIELD HAS
SPROUTED ACROSS LOWER MICHIGAN THIS AFTERNOON...LATEST OBJECTIVE
ANALYSIS INDICATING 500-1500J/KG MLCAPE IN PLACE ACROSS NORTHERN
LOWER MICHIGAN. NOT MUCH GOING JUST YET...THOUGH STARTING TO GET
SOME SCATTERED RADAR RETURNS OVER CENTRAL/SOUTHERN LOWER. BROAD
AREA OF LOW LEVEL MOISTURE CONVERGENCE ACROSS THE LOWER PENINSULA
AND WATER VAPOR IMAGERY SUGGESTS STARTING TO GET UNDER SOME UPWARD
FORCING ASSOCIATED WITH TAIL END UP ONTARIO SHORT WAVE TROUGH. ALSO
WATCHING FOR CONVECTIVE DEVELOPMENT FARTHER UPSTREAM ALONG COLD
FRONT OVER UPPER MISSISSIPPI VALLEY WHERE MLCAPE HAS INCREASED TO
2500-3500J/KG WITH SHRINKING MLCINH.
SURFACE LOW PASSING NORTH OF LAKE SUPERIOR THIS EVENING WILL DRAG
ITS ASSOCIATED COLD FRONT ACROSS NORTHERN MICHIGAN TONIGHT. PUSH OF
COOLER AIR THEN ARRIVES TUESDAY AS WINDS SWING AROUND TO THE
NORTHWEST...AND SHOULD BE A BIT BREEZY AS WELL AS HIGH PRESSURE
SQUEEZES INTO THE UPPER LAKES BY TUESDAY NIGHT. FORECAST CONCERNS
WILL DEAL INITIAL WITH CONVECTIVE TRENDS AHEAD OF THE APPROACHING
COLD FRONT TONIGHT...THEN SOME CLOUD/WIND ISSUES FOR TUESDAY.
TONIGHT/TUESDAY: WEATHER...EVEN WITHOUT ANY LATE AFTERNOON/EARLY
EVENING CONVECTIVE DEVELOPMENT LOCALLY...UPSTREAM COLD FRONT SHOULD
LIGHT UP WITH THUNDERSTORMS THAT SHOULD ARRIVE OVER THE FORECAST
AREA TOWARD LATE EVENING/MIDNIGHT. PLAN TO MARCH A BAND OF LIKELY
POPS ACROSS THE FORECAST AREA IN 3 HOUR INCREMENTS...ENDING FROM
WEST TO EAST AFTER MIDNIGHT. PRETTY EXTENSIVE AREA OF LOW CLOUDS
BEHIND THE COLD FRONT WHICH SHOULD DROP INTO SOUTHERN LOWER BY
DAYBREAK TUESDAY. LOW LEVEL CYCLONIC FLOW AND COLD ADVECTION SHOULD
SUPPORT DIURNAL AUGMENTATION OF THIS CLOUD DECK...SO THOUGH THERE
MAY BE SOME EARLY BREAKS EXPECT THE FORECAST OVERALL TO TREND TOWARD
THE CLOUDIER SIDE.
WINDS...SOUTH/SOUTHWEST GENERALLY UNDER 10 MPH TO START THE NIGHT...
THEN SWINGING AROUND TO NORTHWEST WITH FRONTAL PASSAGE OVERNIGHT.
EXPECT COLD ADVECTION/MIXING TO RESULT IN GUSTY WINDS TUESDAY...
WITH 20-30MPH GUSTS FROM THE NORTHWEST EXPECTED.
TEMPERATURES...LOWS TONIGHT WILL BE DEPENDENT ON LOCATION RELATIVE
TO COLD FRONT...MID/UPPER 50S EASTERN UPPER...AROUND 60-MID 60S
ACROSS NORTHERN LOWER. HIGHS TUESDAY WILL BE IMPACTED BY STRONG LOW
LEVEL COLD ADVECTION...PROBABLY GETTING STUCK IN THE 60S ACROSS
EASTERN UPPER/TIP OF THE MITT COUNTIES WITH LOWER-MID 70S ELSEWHERE.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 402 PM EDT MON JUL 22 2013
MAIN FORECAST CONCERN FOR THE EXTENDED PERIOD WILL BE THE NEXT FROPA
AROUND THE FRIDAY TIME FRAME.
LATEST HEMISPHERIC PATTER ANALYSIS SHOWS A RELATIVELY STABLE/
NON-PROGRESSIVE THREE WAVE PATTERN...WITH AN OMEGA BLOCK SEEN OVER
THE NORTH CENTRAL PACIFIC...SHORT WAVE RIDGING OVER THE WESTERN
STATES AND LARGER SCALE TROUGHING OVER EASTERN CANADA. THIS IS
LEAVING THE GREAT LAKES UNDER A WEST NORTHWEST FLOW REGIME WITH
THE FIRST OF TWO PASSING SHORT WAVES MOVING THROUGH THIS WEEK TO
BRING A FROPA TO THE REGION TONIGHT. GOING THROUGH THE WEEK
THE...FORECAST LOOKS RATHER BENIGN WEATHER WISE...WITH A VERY
BLOCKY PATTERN ON THIS SIDE OF THE NORTHERN HEMISPHERE. THE LOW
OVER THE GULF OF ALASKA AFFILIATED WITH THE NORTH PACIFIC OMEGA
BLOCK WILL MOVE SLOWLY TO THE B.C. COAST BY THE END OF THE WORK
WEEK. THE COMBINATION OF THIS AND A BUILDING RIDGE OVER THE NORTH
ATLANTIC WILL MAINTAIN GENERAL TROUGHINESS FOR THE EASTERN CONUS
RIGHT THROUGH THE END OF THE FORECAST PERIOD...WITH SIGNS THAT
THIS OVERALL PATTERN BREAKING DOWN JUST BEYOND THE FORECAST
PERIOD.
TUESDAY NIGHT THROUGH THURSDAY...THE FIRST OF TWO SHORTWAVES WILL
HAVE MOVED OFF WELL TO THE NORTHEAST TUESDAY NIGHT...WITH SURFACE
HIGH PRESSURE BUILDING INTO THE GREAT LAKES. THIS WILL PROMOTE VERY
COMFORTABLE AND SUNNY CONDITIONS FOR THE DAY ON WEDNESDAY WITH
SEASONABLE TEMPERATURES AND LOW AFTERNOON HUMIDITY. LOOKS LIKE A
GOOD RADIATIONAL COOLING SETUP FOR TUESDAY AND WEDNESDAY NIGHT WITH
THE HIGH IN CLOSE VICINITY TO NORTHERN MICHIGAN...ALLOWING FOR
MOSTLY CLEAR SKIES AND A DECOUPLING BOUNDARY LAYER WITH LOWS FALLING
INTO THE 40S BOTH NIGHTS. UNDERCUT MOST GUIDANCE BY SEVERAL
DEGREES...WITH TUESDAY NIGHT LOOKING TO BE THE CHILLIER OF THE TWO
DUE TO SOME RESIDUAL COLD AIR ADVECTION. RETURN FLOW LOOKS TO RETURN
FOR THURSDAY AS THE HIGH BEGINS TO SLIDE OFF TO THE EAST. THERE WILL
BE A SLIGHT UPTICK IN TEMPERATURES HUMIDITY...WITH THE ONLY REAL
DIFFERENCE IN SENSIBLE WEATHER JUST BEING SOME MID/HIGH LEVEL CLOUD
COVER AHEAD OF THE NEXT WEATHER SYSTEM AND PERHAPS SOME CU THURSDAY
AFTERNOON.
THURSDAY NIGHT THROUGH SATURDAY...THE NEXT SHORTWAVE WILL DROP OUT
OF SOUTH CENTRAL CANADA TOWARD THE GREAT LAKES THURSDAY NIGHT. THE
ASSOCIATED SURFACE LOW AND COLD FRONT LOOKS TO ENTER THE GREAT LAKES
SOMETIME IN THE THURSDAY NIGHT TO FRIDAY TIME FRAME...PROVIDING THE
NEXT CHANCE OF CONVECTION ACROSS THE GREAT LAKES. THE 12Z GEM IS
MOST AGGRESSIVE WITH THE FROPA...CLEARING NORTHERN MICHIGAN BY
FRIDAY AFTERNOON. FAVOR THE SLOWER GFS/ECMWF SOLUTIONS...ESPECIALLY
WITH THE MAIN UPPER WAVE SLOWING DOWN AND CLOSING OFF OVER EASTERN
ONTARIO BY SATURDAY. COULD SEE THE TIMING OF THE FROPA SLOWING DOWN
A BIT WITH THIS SETUP...AND MAINTAINED POPS IN THE FORECAST INTO
SATURDAY TO REFLECT THIS IDEA.
SUNDAY THROUGH MONDAY...HIGH PRESSURE BUILDS BACK INTO THE GREAT
LAKES...WITH A COOLISH PATTERN RETURNING ONCE AGAIN TO THE REGION.
SOME GUIDANCE EVEN SUGGESTING HIGHS IN THE 60S BY LATE THIS WEEKEND
AS COOL CANADIAN AIR MASS SETTLES IN. A BUILDING RIDGE LOOKS TO TAKE
SHAPE TOWARD THE END OF THE FORECAST PERIOD...WITH NEAR TO ABOVE
NORMAL TEMPS POTENTIAL RETURNING TOWARD THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE JUL 23 2013
UPDATED THINKING: NOT SO SURE WIDESPREAD LOWER CEILINGS WILL
DEVELOP BEHIND THE FRONT...AS DRIER AIR IS ALREADY BLEEDING
SOUTHWARD PRETTY QUICKLY. STILL NOT IMPOSSIBLE FOR SOME LOWER
STRATUS TO FOR A AN HOUR OR TWO BEHIND THE FRONT...BUT THINK THAT
STRONGER PUSH OF COLD ADVECTION WILL WORK TO ERADICATE THAT THREAT
QUICKLY.
EARLIER DISCUSSION BELOW:
SOME SHRA/TSRA OVERNIGHT...CIG RESTRICTIONS TOWARD DAWN.
A COLD FRONT WAS MOVING ACROSS EASTERN UPPER MI AND FAR NORTHERN
LAKE MI AT MIDNIGHT. THIS FRONT WILL CROSS NORTHERN LOWER MI
OVERNIGHT. MARGINAL LLWS WILL BE SEEN JUST AHEAD OF THE WARM
FRONT. SHRA/TSRA ALONG THE FRONT TO OUR WEST WILL MOVE IN
TONIGHT...WITH PLN MOST LIKELY TO SEE TS.
WITH THE EXTRA MOISTURE INPUT INTO THE LOW LEVELS...MVFR CIGS ARE
LIKELY JUST BEHIND THE COLD FRONT. THAT WILL QUICKLY LIFT TO VFR
TUESDAY MORNING.
LIGHT SW WINDS TONIGHT...VEERING NW LATE. RATHER GUSTY NW TO NNW
WINDS TUESDAY.
&&
.MARINE...
ISSUED AT 402 PM EDT MON JUL 22 2013
SOUTH/SOUTHWEST GRADIENT WINDS EARLY TONIGHT WILL SWING AROUND TO
NORTHWEST OVERNIGHT WITH PASSAGE OF A COLD FRONT...AND WILL BECOME
GUSTY TUESDAY GIVEN DECENT MIXING/DECREASING OVERWATER STABILITY
WITH COLD ADVECTION. GUSTS TO 30KTS LIKELY WITHIN MOST NEARSHORE
ZONES...SO WILL GO AHEAD AND ISSUE A PRE-EMPTIVE SMALL CRAFT
ADVISORY FOR TUESDAY. INCREASING SWIM RISK ALSO LIKELY TUESDAY
AFTERNOON ON LAKE MICHIGAN BEACHES SOUTH OF GRAND TRAVERSE LIGHT.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR LHZ345-346.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT EDT
TONIGHT FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR LMZ341.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO MIDNIGHT EDT
TONIGHT FOR LMZ323-342-344>346.
LS...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR LSZ321-322.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...AJS
SHORT TERM...JPB
LONG TERM...NTS
AVIATION...JZ/LAWRENCE
MARINE...JPB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1219 PM CDT Tue Jul 23 2013
.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013
Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.
A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.
Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.
Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.
.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013
The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.
Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.
Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecast for Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1213 PM CDT TUE JUL 23 2013
Rather difficult aviation forecast into the overnight hours. Decaying
showers from old MCV will approach the KC terminals within the
upcoming hour, with primary frontal boundary now well south across
southeastern portions of Kansas. Short term models have struggled to
resolve northwesterly mid-level flow, resulting in poor QPF placement
and unresolved surface boundaries. Through this afternoon, generally
feel that convective chances remain low, with stabilizing mid-level
clouds preventing much in the way of a warmup. Higher convective
chances will refocus over southern NE and western Iowa as well as
near surface and elevated boundary over central Kansas and into the
Ozark Plateau.
Later this evening, a secondary shortwave over the Dakotas will move
into the region, which could force redevelopment of elevated showers
and thunderstorms closer to the terminals along an 850 mb moisture
axis. This activity should be focused between 02z-06z before drifting
south into Wednesday morning. High pressure will bring dry conditions
and light winds for Wednesday.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...73
AVIATION...Dux
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
643 AM CDT Tue Jul 23 2013
.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013
Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.
A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.
Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.
Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.
.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013
The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.
Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.
Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecasted for Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 633 AM CDT TUE JUL 23 2013
An outflow boundary preceding convection over NE will push through
the terminals early in the forecast. Expect to see gusty NNW winds
for an hour or two.
Shower and thunderstorm complex from eastern NE into north central KS
may not have much left to it by the time it reaches west central MO
by mid morning. Radar has shown an overall weakening trend since
10z. Could see the KS portion of the system strengthen as it moves
into the most unstable airmass. However, short range models suggest
this initial activity will pretty much dissipate before new activity
reforms. Thus, can only support VCTS until tonight when PROB30 will
be used.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
422 AM CDT Tue Jul 23 2013
.SHORT TERM...(Today through Wednesday night)
Issued at 421 AM CDT TUE JUL 23 2013
Today through Tonight...Fickle northwest flow and muddled surface
boundaries will dictate our rain chances during this period. For the
past several days perturbations embedded within the northwest flow
have skirted by the bulk of the CWA with only the far northern and
northeastern counties receiving any beneficial rainfall. This may
change today as a relatively large convective complex continues to
track southeast through central NE.
A moderately strong mesohigh/cold pool and likely a developing MCV
are driving this feature. GFS/NAM/ECMWF have been pretty consistent
for the past few runs with this feature and maintain its strength
and resulting precipitation through the day and into the evening.
Only the HRRR has shown a tendency for the rain to fall apart
starting mid morning. This is a typical characteristic/phase of
convective systems which show a decided weakening from mid morning
through early afternoon before regenerating later in the afternoon.
Latest SPC meso page shows rather high MUCAPE of 3000-4000J/kg
downstream from this convection over northeast KS/northwest MO. Am
expecting the central NE convection to head for this better
instability and maintain its strength into mid morning. Surprisingly
there is moderately strong 0-6km shear of 40kts north of the MO
River so severe storms are possible. Have raised PoPs over the
western 1/2 of the CWA and adjusted them for the expected track of
this MCS. Will let day shift determine if this system will go
through the typical weakening/re-strengthening phases. Temperatures
will be problematic due to timing/location of cloud cover and
rain-cooled air. Have lowered them across the northern 1/2 of the
CWA.
Scattered convection expected to continue tonight with the northeast
third of the forecast area possibly missing out on the rain this
time.
Wednesday/Wednesday night...Could see lingering rain chances over
the far southern counties Wednesday morning as the convective
complex exists the CWA. Then expect dry, cooler and drier air to
spread into the region as high pressure settles in across IA through
IL and provides a northeast to easterly wind. Blended approach on
temperatures look reasonable with exceptionally pleasant weather for
Wednesday night/Thursday morning.
.LONG TERM...(Thursday through Monday)
Issued at 421 AM CDT TUE JUL 23 2013
The long range models are in better agreement with the 23/00Z runs
then in previous iterations. There is still however, a bit of
disagreement as to the timing of features that will affect the area
during this timeframe.
Thursday looks to be a very pleasant day with surface high pressure
over the area. Temperatures will be a few degrees below seasonal
averages with highs in the low to mid 80s. Thursday night there will
be two features of interest that will affect the area. The first is
a upper level trough moving through the Great Lakes region. This
will force a cold front into the Upper Midwest and back into the
Central Plains. Thunderstorms will develop out ahead of this front
and will move into northern Missouri Thursday night. Storms will
continue across northern Missouri on Friday as this front moves into
the area. The second feature of interest is an upper level shortwave
rounding an upper level ridge out west and dropping into the local
area on northwest flow on the lee side of the upper ridge. This
shortwave is actually remnant energy from the retrograding upper
level system that affected the region two weekends ago. The GFS/GEM
and ECMWF all depict a cluster of storms perhaps an MCS developing
across central Kansas Thursday night that will move into
central/southern Missouri either late Thursday night into Friday
(the faster GFS) or into Friday/Friday night (the slower EC and
GEM). In either case have chance POPs forecast for Thursday night
through Friday night.
Surface high pressure is advertised for the area behind the
departing cold front which should make for a very pleasant weekend
with highs in the upper 70s to lower 80s. Also, by the end of the
weekend there will be an overall pattern shift across the CONUS to a
more quasi-zonal pattern. This will be caused by a serious of
shortwaves moving through the Rockies which will suppress the
western CONUS ridge. The first of these shortwave is progged to
reach the area by Sunday night (still faster GFS) or early Monday
morning (the still slower EC). Either way, storms are expected to
linger into Monday across the area. That said have slight chance
POPs in for Sunday night to account for the faster GFS and have
chance POPs forecasted for Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1243 AM CDT TUE JUL 23 2013
While VFR conditions will prevail outside of any convection the
forecast will be a challenging one. Scattered convection along/ahead
of a cold front dropping south across northern MO is likely to pass
northeast of the terminals overnight. However, TDWR radar from MCI
shows an outflow boundary from this convection will likely pass
through KSTJ at the start of the forecast with gusty winds.
Also watching a couple of convective complexes over the Northern and
Central High Plains which a couple of convective allowing models plus
the 00z GFS/NAM suggest this activity have the potential to affect
the terminals this afternoon. While confidence is boosted by all of
these models indicating convection for late Thursday
afternoon/evening best to go the conservative route as previous model
runs have had a poor track record.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT MON JUL 22 2013
.UPDATE...
ISSUED AT 948 PM CDT MON JUL 22 2013
MAIN ITEM OF INTEREST FOR THE REST OF NIGHT IS THE PROBABILITY OF
SHOWERS AND THUNDERSTORMS. THE GREATEST ATTENTION IS FOCUSED ON
THE LOOSELY ORGANIZED MCS ACROSS IOWA THAT IS OCCURRING AHEAD OF
THE ENCROACHING COLD FRONT. THE SYSTEM HAS DEVELOPED A DECENT COLD
POOL AND THERE IS SOME VIGOROUS CONVECTION ALONG THE WESTERN
FLANK. THE LOW LEVEL INFLOW INTO THE SYSTEM IS NOT PARTICULARILY
STRONG AT 20 KTS OR LESS AND FROM THE WEST...BUT THE AIR MASS
ACROSS EASTERN MO INTO WESTERN IL IS QUITE UNSTABLE WITH SBCAPE OF
2000-3000 J/KG. DEEP LAYER SHEAR VECTORS AND CFM VECTORS WOULD
SUGGEST THAT IF THE MCS CAN MAINTAIN SOME ORGANIZATION THAT IT
WOULD TEND TO MOVE SEWD...AND THE WESTERN FLANK OF THE SYSTEM
WOULD HAVE THE BEST CHANCE OF MAINTAINING SOME IDENTITY GIVEN THE
DIRECTION OF LOW LEVEL INFLOW. LOW LEVEL WAA IN ADVANCE OF THE
SYSTEM COULD ALSO GENERATE SOME SCATTERED ACTIVITY GIVEN THE MOIST
AND UNSTABLE AIR MASS IN PLACE. SOME OF THE EARLIER HRRR RUNS
DEPICTED THESE SCENARIOS WITH BOTH SOME SCATTERED WAA DEVELOPMENT
AND SOME DECAYING ELEMENTS OF THE MCS SINKING SEWD THRU ERN MO. AS
A RESULT I HAVE CHANGED THE CONFIGURATION OF THE POPS OVERNIGHT
INTO EARLY TUESDAY AND INCREASED THEM IN A FEW AREAS.
GLASS
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013
RELATIVELY QUIET DAY TODAY THANKS TO SUBSIDENCE IN THE WAKE OF THE
SHORTWAVE THAT MOVED ACROSS THE AREA LAST NIGHT. CURRENT SURFACE
ANALYSIS SHOWS A COLD FRONT STRETCHING FROM NEBRASKA...THROUGH
NORTHWEST IOWA AND THEN NORTH BISECTING MINNESOTA. MEANWHILE...
ACTIVE CONVECTION CONTINUES TO REINFORCE AN OUTFLOW BOUNDARY ACROSS
SOUTHWEST KANSAS...OKLAHOMA AND ARKANSAS.
TONIGHT...COLD FRONT IS FORECAST BY ALL MODEL GUIDANCE TO STEADILY
MARCH SOUTHEAST...ENTERING THE NORTHERN CWA BY 12Z. DESPITE THE
APPROACHING COLD FRONT...A SUBTLE SHORTWAVE RIPPLING SOUTHEAST FROM
THE PLAINS AND ABUNDANT LOW LEVEL MOISTURE...THE MODELS REMAIN
STINGY ON QPF TONIGHT. I BELIEVE THIS IS BECAUSE THE CONVECTION THAT
FIRES AHEAD OF THE FRONT WILL LIKELY DISSIPATE/WEAKEN AS IT MOVES
INTO THE NORTHERN CWA LATER THIS EVENING WITH LOSS OF DIURNAL
INSTABILITY...AND THAT ANY NOCTURNAL DEVELOPMENT MAY BE CONFINED
FURTHER WEST WHERE BETTER 850 MOISTURE CONVERGENCE APPEARS LIKELY TO
OCCUR TO THE NORTHEAST OF THE AFOREMENTIONED EFFECTIVE SURFACE
BOUNDARY.
TUESDAY...COLD FRONT WILL BE MOVING THROUGH THE CWA WITH BEST
CHANCES OF THUNDERSTORMS RE FIRING ALONG AND SOUTH OF INTERSTATE 70
BY LATE MORNING/EARLY AFTERNOON. SPC GENEROUSLY PLACED MUCH OF THE
CWA IN A SLIGHT RISK ON THEIR LATEST DAY2 OUTLOOK. PERSONALLY THE
LACK OF ANY SIGNIFICANT SHORTWAVE UPSTREAM HAS ME THINKING THAT
COVERAGE AND THEREFORE SEVERE THREAT MAY REMAIN ISOLATED TO
SCATTERED. HAVE MAINTAINED CHANCE POPS.
TUESDAY NIGHT AND WEDNESDAY...SYNOPTIC SCALE MODELS CONTINUE TO
TREND FURTHER SOUTHWEST WITH THE DEVELOPMENT OF AN MCS...AND HAVE
FOLLOWED SUIT AS HIGH PRESSURE BUILDS INTO THE CWA. GIVEN THE
POSITION OF THE EFFECTIVE BOUNDARY RIGHT NOW...AND THE FACT THAT THE
COLD FRONT WILL HAVE PUSHED IT FURTHER SOUTH...CAN`T IMAGINE MY CWA
BEING IMPACTED BY AN MCS DURING THIS PERIOD. MUCH COOLER
TEMPERATURES ARE EXPECTED ON WEDNESDAY WITH HIGHS IN THE LOWER 80S.
WEDNESDAY NIGHT AND THURSDAY...THE SURFACE RIDGE AXIS SHOULD BE IN
CONTROL OF THE CWA DURING THIS TIME PERIOD WITH BELOW AVERAGE
TEMPERATURES AND MOSTLY CLEAR SKIES.
CVKING
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 208 PM CDT MON JUL 22 2013
ANOTHER STRONG SHORTWAVE TROF AND COLD FRONT WILL BRING A CHANCE OF
SHOWERS AND THUNDERSTORMS TO THE REGION FRIDAY THROUGH SATURDAY
MORNING. HIGH PRESSURE TAKES HOLD OF THE AREA BY SATURDAY AFTERNOON
AND DRY WEATHER WILL CONTINUE THROUGH SUNDAY NIGHT. TEMPERATURES
WILL BE BELOW NORMAL DURING THIS PERIOD WITH CLOUD COVER AND
PRECIPITATION ON FRIDAY AND THEN COLD ADVECTION THE REMAINDER OF THE
WEEKEND AS 850MB TEMPERATURES DROP INTO THE LOWER TEENS.
CVKING
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON JUL 22 2013
PROBABILITY FOR THUNDERSTORMS CONTINUES TO BE THE MAIN CHALLENGE
FOR THE REST OF TONIGHT AND INTO TUESDAY. AN OUTFLOW BOUNDARY
GENERATED BY A COMPLEX OF THUNDERSTORMS OVER IOWA EARLIER IN THE
EVENING IS MOVING THROUGH NORTHERN MISSOURI AND WEST CENTRAL
ILLINOIS AT THIS TIME. THIS BOUNDARY IS PRODUCING A WIND SHIFT
TO THE NORTH WITH GUSTS UP TO AROUND 20KTS...AND IS GENERATING
SCATTERED THUNDERSTORMS AS IT MOVES INTO OUR AREA. I EXPECT THIS
GENERAL TREND TO CONTINUE...WITH THE BOUNDARY MOVING SOUTH ACROSS
THE REGION GENERATING STORMS AS IT GOES. THINK COVERAGE OF STORMS
AND INTENSITY SHOULD GENERALLY DECREASE AS THE BOUNDARY MOVES FURTHER
SOUTHEAST...THO IT`S POSSIBLE THAT CENTRAL MO MAY SEE GREATER
COVERAGE AS THE AIR WILL BE MORE UNSTABLE FURTHER WEST.
EXPECT THE BOUNDARY TO STALL SOMEWHERE NEAR THE I-70 CORRIDOR ON
TUESDAY MORNING UNLESS THERE ARE MORE STORMS THAN EXPECTED TO
PUSH IT FURTHER SOUTH. EXPECT MORE THUNDERSTORMS TO FORM DURING
THE AFTERNOON TUESDAY ALONG AND SOUTH OF THE FRONT.
SPECIFICS FOR KSTL...
PROBABILITY FOR THUNDERSTORMS CONTINUES TO BE THE MAIN CHALLENGE
FOR THE REST OF TONIGHT AND INTO TUESDAY. AN OUTFLOW BOUNDARY
GENERATED BY A COMPLEX OF THUNDERSTORMS OVER IOWA EARLIER IN THE
EVENING IS MOVING THROUGH NORTHERN MISSOURI AND WEST CENTRAL
ILLINOIS AT THIS TIME. THIS BOUNDARY IS PRODUCING A WIND SHIFT
TO THE NORTH WITH GUSTS UP TO AROUND 20KTS...AND IS GENERATING
SCATTERED THUNDERSTORMS AS IT MOVES INTO OUR AREA. WILL INTRODUCE
A VCTS AT THE TERMINAL STARTING AT 08Z WHICH IS ABOUT THE TIME THE
OUTFLOW BOUNDARY WILL MOVE INTO THE AREA. THINK COVERAGE OF
STORMS AND INTENSITY SHOULD GENERALLY DECREASE AS THE BOUNDARY
MOVES INTO THE METRO AREA...BUT THE LIKELIHOOD OF A STORM LOOKS
HIGHER THAN IT DID EARLIER THIS EVENING.
EXPECT THE BOUNDARY TO STALL SOMEWHERE NEAR THE I-70 CORRIDOR ON
TUESDAY MORNING UNLESS THERE ARE MORE STORMS THAN EXPECTED TO
PUSH IT FURTHER SOUTH. EXPECT MORE THUNDERSTORMS TO FORM DURING
THE AFTERNOON TUESDAY ALONG AND SOUTH OF THE FRONT.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
1147 AM MDT TUE JUL 23 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
A VERY SUBTLE DISTURBANCE IN THE UPPER FLOW WORKING ALONG THE
STATIONARY BOUNDARY IS PRODUCING SCATTERED GENERAL THUNDERSTORMS
AND SHOWERS THAT ARE CURRENTLY MOVING EAST ALONG THE NORTHERN
TIER THIS MORNING. THESE STORMS ARE EXPECTED TO SPREAD MORE TO THE
SOUTHEAST THIS AFTERNOON AND POSSIBLY BECOME STRONG ENOUGH TO GO
SEVERE. SPC THIS MORNING ADDED OUR SOUTHEAST COUNTIES TO ITS
CONVECTIVE OUTLOOK FOR SLIGHT RISK FOR SEVERE. THE GRID REFLECT
THIS PATTERN SO FEW CHANGES. SCT
PREVIOUS DISCUSSION...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.
TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.
DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECMWF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL
NOT GO COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE
CHANGES IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT
LITTLE IN THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL
DAYS. LOW TEMPERATURES WILL GENERALLY RANGE ACROSS THE CWA IN THE
MID 50S TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE
OF THUMB. MALIAWCO
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.
A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.
SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER
&&
.AVIATION...
VFR CONDITIONS. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS
THE AREA THIS AFTERNOON AND EVENING THAT MAY IMPACT ANY OF THE FOUR
TERMINALS WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING
OF INDIVIDUAL STORMS IS LOW AT THIS TIME. WINDS WILL REMAIN EAST TO
NORTHEAST 5 TO 10 KNOTS. DWB
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1120 AM MDT Tue Jul 23 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Update forthcoming. Have made minor adjustments to sky and pop
grids. Generally dry forecast continues with the exception being the
Hi-Line. CAPE values approaching 2000 J/kg develop along the
international border this afternoon and HRRR analysis indicates
thunderstorms developing across northern Hill and Blaine counties
later this afternoon. Temperatures look good. Emanuel
&&
.AVIATION...
UPDATED 1720Z.
An upper level ridge of high pressure will keep much of the area
under light winds and clear skies through the TAF period. The
exception will be around the KCTB area this afternoon where
instability may result in the development of a few thunderstorms.
Quite a bit of uncertainty regarding the coverage of thunderstorms
so will limit mention of thunder to VCTS. Any storms that develop
should diminish after sunset. Langlieb
&&
.PREV DISCUSSION...Issued 500 AM MDT Tue Jul 23 2013
Today through Thursday...High pressure building over the Rocky
Mountains will keep the forecast area mostly dry with the
continued exception being along the Canadian border. Today
will be a copy of Monday with a few afternoon and evening
thunderstorms developing over portions of North Central Montana
near the border. Wednesday looks fairly similar to Tuesday with
the chances for thunderstorms dipping a bit further south,
especially during the evening. Instability over Montana itself
does not look overly impressive but the storms look to develop
over the Canadian Rockies, where conditions are much more
favorable, and move southeast into Montana. Moisture begins to
creep back in from Idaho Thursday and some scattered thunderstorms
may return to Southwest Montana. These may pose an issue with the
extremely dry conditions there of late. Expect winds to be light
through the period and temperatures to remain pretty warm.
Thursday night through Monday...The upper level high pressure ridge
will be centered over central Montana, while to the west, a low
pressure trof will be approaching the West Coast. The combination of
moisture creeping underneath the ridge from the south and falling
heights aloft will continue a chance of thunderstorms across the
forecast area into the evening. The airmass will remain quite dry
across the northern portions of the region Friday and most
convection will be over Southwest Montana. This pattern will
continue into Saturday although the trof from the west will be
approaching the Rockies and increasing instability across the area.
The trof will move through the region Saturday night, increase the
chance of showers and thunderstorms, and cool the airmass. The low
pressure center associated with the trof will remain over Alberta
and another trof will rotate across the West Coast. This will keep
the region underneath unsettled southwest flow aloft through the end
of the forecast period. However, the airmass will also remain quite
dry and convection will not be widespread. Temperatures will be well
above normals at the beginning of the forecast period. The airmass
will cool as the trof moves over the region Sunday and temperatures
will drop nearer to seasonal normals...yet most locations will still
remain slightly above normals. Zelzer
&&
.FIRE WEATHER...
Relative humidity will dip dangerously low again this afternoon
and evening but winds should be fairly light overall. The threat
for critical fire conditions will drop as a result, but things
will remain very dry across much of Central and Southwest Montana.
Scattered thunderstorms over North Central Montana today will be
in areas of higher relative humidity and will only pose a slight
risk of lightning fire starts. Conditions over Southwest Montana
are another story. Extremely dry weather looks to continue with
moisture and instability beginning to creep up from Idaho on
Thursday. This will result in a chance of elevated thunderstorms
that may produce little precipitation. This combination could
cause new fire starts later in the week. Fire weather highlights
are not anticipated today, but conditions will continue to be
closely monitored, especially over Southwest Montana.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 89 54 90 55 / 0 0 0 10
CTB 82 53 83 53 / 20 10 10 20
HLN 91 56 92 58 / 0 0 0 10
BZN 88 50 90 53 / 0 0 10 10
WEY 79 43 82 47 / 0 0 20 10
DLN 86 51 88 55 / 0 0 10 10
HVR 85 55 85 56 / 20 10 10 10
LWT 84 55 85 54 / 0 0 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1025 AM MDT Tue Jul 23 2013
.DISCUSSION...
Update forthcoming. Have made minor adjustments to sky and pop
grids. Generally dry forecast continues with the exception being the
Hi-Line. CAPE values approaching 2000 J/kg develop along the
international border this afternoon and HRRR analysis indicates
thunderstorms developing across northern Hill and Blaine counties
later this afternoon. Temperatures look good. Emanuel
&&
.AVIATION...
UPDATED 1108Z.
Isolated thunderstorms continue to track north of the Canadian
border but will drift south and cross northeast portions of the
region later this morning....in the vcnty and east of KHVR. This
area will also become unstable during the afternoon and a chance for
new thunderstorm development exists. Elsewhere, high pressure aloft
will keep the airmass dry and generally stable. Winds will remain
light through the period and VFR conditions will prevail through the
next 24 hours.
&&
.PREV DISCUSSION...Issued 500 AM MDT Tue Jul 23 2013
Today through Thursday...High pressure building over the Rocky
Mountains will keep the forecast area mostly dry with the
continued exception being along the Canadian border. Today
will be a copy of Monday with a few afternoon and evening
thunderstorms developing over portions of North Central Montana
near the border. Wednesday looks fairly similar to Tuesday with
the chances for thunderstorms dipping a bit further south,
especially during the evening. Instability over Montana itself
does not look overly impressive but the storms look to develop
over the Canadian Rockies, where conditions are much more
favorable, and move southeast into Montana. Moisture begins to
creep back in from Idaho Thursday and some scattered thunderstorms
may return to Southwest Montana. These may pose an issue with the
extremely dry conditions there of late. Expect winds to be light
through the period and temperatures to remain pretty warm.
Thursday night through Monday...The upper level high pressure ridge
will be centered over central Montana, while to the west, a low
pressure trof will be approaching the West Coast. The combination of
moisture creeping underneath the ridge from the south and falling
heights aloft will continue a chance of thunderstorms across the
forecast area into the evening. The airmass will remain quite dry
across the northern portions of the region Friday and most
convection will be over Southwest Montana. This pattern will
continue into Saturday although the trof from the west will be
approaching the Rockies and increasing instability across the area.
The trof will move through the region Saturday night, increase the
chance of showers and thunderstorms, and cool the airmass. The low
pressure center associated with the trof will remain over Alberta
and another trof will rotate across the West Coast. This will keep
the region underneath unsettled southwest flow aloft through the end
of the forecast period. However, the airmass will also remain quite
dry and convection will not be widespread. Temperatures will be well
above normals at the beginning of the forecast period. The airmass
will cool as the trof moves over the region Sunday and temperatures
will drop nearer to seasonal normals...yet most locations will still
remain slightly above normals. Zelzer
&&
.FIRE WEATHER...
Relative humidity will dip dangerously low again this afternoon
and evening but winds should be fairly light overall. The threat
for critical fire conditions will drop as a result, but things
will remain very dry across much of Central and Southwest Montana.
Scattered thunderstorms over North Central Montana today will be
in areas of higher relative humidity and will only pose a slight
risk of lightning fire starts. Conditions over Southwest Montana
are another story. Extremely dry weather looks to continue with
moisture and instability beginning to creep up from Idaho on
Thursday. This will result in a chance of elevated thunderstorms
that may produce little precipitation. This combination could
cause new fire starts later in the week. Fire weather highlights
are not anticipated today, but conditions will continue to be
closely monitored, especially over Southwest Montana.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 89 54 90 55 / 0 0 0 10
CTB 82 53 83 53 / 20 10 10 20
HLN 91 56 92 58 / 0 0 0 10
BZN 88 50 90 53 / 0 0 10 10
WEY 79 43 82 47 / 0 0 20 10
DLN 86 51 88 55 / 0 0 10 10
HVR 85 55 85 56 / 20 10 10 10
LWT 84 55 85 54 / 0 0 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
948 AM MDT TUE JUL 23 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
A VERY SUBTLE DISTURBANCE IN THE UPPER FLOW WORKING ALONG THE
STATIONARY BOUNDARY IS PRODUCING SCATTERED GENERAL THUNDERSTORMS
AND SHOWERS THAT ARE CURRENTLY MOVING EAST ALONG THE NORTHERN
TIER THIS MORNING. THESE STORMS ARE EXPECTED TO SPREAD MORE TO THE
SOUTHEAST THIS AFTERNOON AND POSSIBLY BECOME STRONG ENOUGH TO GO
SEVERE. SPC THIS MORNING ADDED OUR SOUTHEAST COUNTIES TO ITS
CONVECTIVE OUTLOOK FOR SLIGHT RISK FOR SEVERE. THE GRID REFLECT
THIS PATTERN SO FEW CHANGES. SCT
PREVIOUS DISCUSSION...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.
TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.
DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECMWF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL
NOT GO COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE
CHANGES IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT
LITTLE IN THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL
DAYS. LOW TEMPERATURES WILL GENERALLY RANGE ACROSS THE CWA IN THE
MID 50S TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE
OF THUMB. MALIAWCO
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.
A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.
SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER
&&
.AVIATION...
MOSTLY VFR. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS THE
AREA TODAY AND TONIGHT THAT MAY IMPACT ANY OF THE FOUR TERMINALS
WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING ANY
INDIVIDUAL STORMS AT A TAF SITE IS LOW AT THIS TIME. WILL MENTION
CB IN THE TAFS. WILL SEE EAST TO NORTHEAST WINDS 5 TO 10 KNOTS.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
339 AM MDT TUE JUL 23 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
ISOLATED SHOWERS CONTINUE TO TRAVERSE ACROSS THE CWA VERY EARLY
THIS MORNING. CURRENT RADAR OBSERVATIONS INDICATE SHOWERS AND
EMBEDDED THUNDER ENTERING SOUTHWESTERN SASKATCHEWAN FROM SOUTHERN
ALBERTA AT THIS TIME. RECENT HRRR RUNS BRING THIS ACROSS THE
NORTHERN ZONES DURING THE LATE MORNING AND INTO THE AFTERNOON
HOURS. THIS HAS ADDITIONAL SUPPORT FROM THE 23/00Z ECMWF/NAM/GFS
SOLUTIONS DESPITE SUBTLE DIFFERENCES IN PLACEMENT AND TIMING. WILL
KEEP POPS GOING THROUGH MOST OF THE CWA WITH HIGHEST POPS ACROSS
THE INTERNATIONAL BORDER AND FURTHER EAST CLOSER TO NORTH DAKOTA.
WILL OPT TO KEEP PETROLEUM COUNTY DRY FOR NOW ALTHOUGH A VERY
ISOLATED SHOWER CANNOT ENTIRELY BE RULED OUT. FORECAST SOUNDINGS
INDICATE ENOUGH INSTABILITY TO INSERT MENTION OF SMALL HAIL AND
GUSTY WINDS INTO THE GRIDS. NAM BUFKIT SOUNDINGS SHOWS HIGHEST
CAPE FURTHER EAST. WILL NOT ENTIRELY RULE OUT A VERY ISOLATED
SEVERE THUNDERSTORM...ESPECIALLY ACROSS THE FAR NORTHERN AND
EASTERN ZONES DURING THE LATE AFTERNOON AND EVENING HOURS. DID
LEAVE ENOUGH FLEXIBILITY HOWEVER THAT THE DAY SHIFT CAN HAVE SOME
WIGGLE ROOM IF THEY HAVE A DIFFERENT ASSESSMENT. THE UPPER LEVEL
SHORTWAVE IS ALREADY APPARENT ON WATER VAPOR IMAGERY AND AS THIS
INTERACTS WITH A SLOWLY EASTWARD MOVING FRONTAL BOUNDARY CURRENTLY
STRETCHING FROM NORTHWEST TO SOUTHEAST ACROSS THE CWA...CONFIDENT
THAT SHOWERS AND THUNDERSTORMS WILL BECOME MORE SCATTERED ACROSS
THE FORECAST REGION.
TUESDAY NIGHT INTO WEDNESDAY...UPPER LEVEL SHORTWAVE EXITS
NORTHEAST MONTANA AS HIGH PRESSURE SETTLES IN. THIS WILL LEAD TO
LARGE SCALE SUBSIDENCE AND MOSTLY DRY CONDITIONS ACROSS THE CWA.
ANOTHER SUBTLE SHORTWAVE WILL APPROACH BY WEDNESDAY AFTERNOON AND
DID INCLUDE MENTION OF SHOWERS AND THUNDERSTORMS WITH SLIGHT
CHANCE POPS AFTER 18Z ACROSS THE FAR NORTH...OVERSPREADING THE CWA
DURING THE EVENING AND AT NIGHT.
DIFFERENCES EXIST IN MODEL SOLUTIONS ON TIMING/TRACK OF NEXT UPPER
LEVEL SYSTEM PUSHING THROUGH NORTHWEST FLOW ALOFT FOR THURSDAY
WITH THE ECWMF/GFS LEANING TOWARDS A DRIER SOLUTION BUT THE NAM
MORE BULLISH. WILL KEEP SLIGHT CHANCE POPS IN THE GRIDS FOR
NOW...BUT MODELS SEEM TO BE CONVERGING TOWARDS DRIER CONDITIONS
WITH THE CWA TO THE RIGHT OF AN UPPER LEVEL RIDGE AXIS IN A
FAVORED REGION OF DEEP VERTICAL SUBSIDENCE. WITH THE UPPER LEVEL
RIDGE AMPLIFYING INTO SOUTHERN ALBERTA...FAVORED AREAS FOR ASCENT
MAY BE MUCH FURTHER TO THE WEST. HOWEVER...AGAIN...IT WILL BE
TRICKY TO TIME SUBTLE SHORTWAVE FEATURES IN THE NORTHWEST FLOW
ALOFT ESPECIALLY GIVEN MODEL DIFFERENCES...AS DISCUSSED...SO WILL NOT GO
COMPLETELY DRY JUST YET. AS FOR TEMPERATURES...WITH LITTLE CHANGES
IN 850MB TEMPERATURES AND 500MB HEIGHT PATTERN...EXPECT LITTLE IN
THE WAY OF TEMPERATURE SWINGS OVER THE NEXT SEVERAL DAYS. LOW
TEMPERATURES WILL GENERALLY RANGE ACROSS THE CWA IN THE MID 50S
TO NEAR 60 WITH HIGHS IN THE LOWER TO MIDDLE 80S AS A RULE OF
THUMB. MALIAWCO
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
CANADIAN HIGH PRESSURE BUILDS INTO NORTH DAKOTA THURSDAY NIGHT AND
FRIDAY. THIS WILL THE FRONT FAR ENOUGH TO THE WEST THAT NORTHEAST
MONTANA WILL SEE DRY WEATHER AND SOMEWHAT COOLER TEMPERATURES.
A SHORTWAVE UPPER RIDGE MOVES THROUGH THE AREA FRIDAY NIGHT AND
SATURDAY. THIS WILL BRING THE FRONTAL BOUNDARY BACK EAST AS A WARM
FRONT. WITH AIRMASS FORECASTED TO BECOME UNSTABLE DURING THE DAY
ON SATURDAY...AFTERNOON AND EVENING THUNDERSTORMS WILL BE
POSSIBLE. WILL MAINTAIN A SLIGHT CHANCE FOR NOW.
SUNDAY THROUGH TUESDAY...MODELS HANDLE A SLOW MOVING UPPER
LOW/TROUGH ACROSS THE CANADIAN PRAIRIES THAT GIVES THE FORECAST
AREA FREQUENT SHORTWAVES IN A NEARLY ZONAL WSW TO WNW FLOW ALOFT.
WILL BROADBRUSH A CHANCE/SLIGHT CHANCE OF THUNDERSTORMS EACH DAY.
FORRESTER
&&
.AVIATION...
MOSTLY VFR. SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST ACROSS THE
AREA TODAY AND TONIGHT THAT MAY IMPACT ANY OF THE FOUR TERMINALS
WITH MVFR FLIGHT CONDITIONS AT TIMES. CONFIDENCE IN TIMING ANY
INDIVIDUAL STORMS AT A TAF SITE IS LOW AT THIS TIME. WILL MENTION
CB IN THE TAFS. WILL SEE EAST TO NORTHEAST WINDS 5 TO 10 KNOTS.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
401 PM CDT TUE JUL 23 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013
THE MAIN FOCUS FOR THIS EVENING/TONIGHT IS ON TSTM POTENTIAL.
CONVECTION WAS ONGOING FOR MUCH OF THE DAY TODAY BUT IN THE LAST FEW
HOURS THIS ACTIVITY HAS DISSIPATED. THE CAP REMAINS STRONG ACROSS
OUR SOUTHERN ZONES WITH THE MAIN BOUNDARY/WARM FRONT ORIENTED ACROSS
SOUTHERN KANSAS.
THIS BEING SAID...REMNANT OUTFLOW BOUNDARIES/DIFFERENTIAL HEATING
BOUNDARIES RESIDE ACROSS OUR CWA WITH THE NORTHERN TWO THIRDS OF OUR
CWA REMAINING UNCAPPED. ONE SUCH BOUNDARY FOR OUR CWA IS ORIENTED
NEAR THE NEB/KS STATE LINE AND CANNOT RULE OUT STRONG/SEVERE STORMS
IN THIS AREA AS BOUNDARY SAGS SOUTH WITH INSTABILITY ON THE ORDER OF
2000 TO 3000 J/KG AND GOOD SHEAR IN OUR NW FLOW REGIME. FARTHER
NORTH...A HIT OR MISS SHOWER/STORM CANNOT BE RULED OUT AS SUBTLE
SHORTWAVE TROUGHS TRANSLATE SE ACROSS THE INTERIOR CONUS. FARTHER
UPSTREAM...NEW STORMS ARE DEVELOPING ACROSS WESTERN SOUTH DAKOTA IN
A SIMILAR MANNER AS 24HRS AGO...BUT CONFIDENCE IS NOT HIGH THAT
THESE STORMS WILL SUSTAIN INTO THE OVERNIGHT HOURS TO IMPACT OUR
REGION...BUT WILL NEED TO MONITOR. THE HRRR TRACKS THIS ACTIVITY
TO THE WEST OF OUR CWA.
ASIDE FM THE HIT OR MISS STORM POTENTIAL...WE ARE LOOKING AT FAIRLY
SEASONAL CONDITIONS OR PERHAPS A FEW DEGREES COOLER THAN NORMAL BOTH
TONIGHT AND WEDNESDAY. A SFC RIDGE AXIS WILL BUILD TO THE SOUTHWEST
FM THE UPPER MIDWEST AND COOLER AIR WILL BACK IN FM THE NORTHEAST.
SFC DPS DROP SEVERAL DEGREES AND OVERNIGHT LOWS SHLD AVERAGE IN THE
UPPER 50S TO LOW 60S. MODELS INDICATE SOME POTENTIAL FOR SOME LOW
CLOUDS AROUND TONIGHT/EARLY WEDNESDAY...MAINLY IN KS. THERE ARE
SOME MODEL DIFFERENCES ON HIGHS FOR WEDNESDAY BUT WITH THE AIRMASS
MORE SIMILAR TO TODAY...WILL AIM FOR HIGH TEMPS IN THE MID/UPPER 80S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013
OVER THE PAST SEVERAL DAYS...MORE AND MORE OF THE CWA HAS
GRADUALLY RECEIVED AT LEAST MINIMAL AMOUNTS OF MEANINGFUL
MEASURABLE RAIN AFTER A VERY DRY START TO THE MONTH...AND THIS
TREND OF VARIOUS...HIT-AND-MISS RAIN CHANCES IN WHICH PARTS OF
THE AREA SEE DECENT PRECIPITATION WHILE OTHERS LARGELY MISS OUT IS
EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AT THIS
TIME...ALL RAIN CHANCES OVER THIS 6-DAY PERIOD HAVE BEEN CAPPED AT
NO MORE THAN 30-50 PERCENT...UNTIL/UNLESS CONFIDENCE INCREASES.
ALTHOUGH VERY SUBJECT TO CHANGE...THE THURS/THURS NIGHT AND SUN
NIGHT/MONDAY TIME FRAMES CURRENTLY CONTAIN THE OVERALL-HIGHEST
COVERAGE OF 30+ POPS. REGARDING SEVERE WEATHER PROSPECTS...ITS
AGAIN MUCH THE SAME STORY AS ALTHOUGH ITS QUITE POSSIBLE...IF NOT
LIKELY...THAT AT LEAST A FEW SEVERE STORMS FLARE UP FROM TIME TO
TIME...THERE IS NO DEFINITIVE SETUP OF HEIGHTENED CONCERN EVIDENT
AT THIS TIME...AND THUS HAVE REFRAINED FROM SPECIFYING ANY PERIODS
IN THE HAZARDOUS WEATHER OUTLOOK. ON A POSITIVE NOTE FOR MOST
FOLKS...THERE IS PRETTY HIGH CONFIDENCE IN A CONTINUED SLIGHTLY BELOW
NORMAL TEMPERATURE REGIME...WITH HIGHS ON MOST DAYS AVERAGING 3-8
DEGREES BELOW AVERAGE LATE-JULY VALUES.
STARTING OFF WEDNESDAY EVENING/NIGHT...SEASONABLY STRONG
NORTHWEST FLOW REMAINS IN PLACE OVER THE CENTRAL PLAINS...BETWEEN
RIDGING CENTERED OVER THE NV/CA/UT/AZ BORDER AREA...AND A BROAD
LONGWAVE TROUGH OVER THE EASTERN CONUS...WHILE A SHORTWAVE TROUGH
DIVES SOUTH-SOUTHEAST ACROSS MANITOBA/SASKATCHEWAN. WITHIN THE
LOCAL FLOW...A LOW-AMPLITUDE SHORTWAVE TROUGH IS PROGGED TO RIDE
EASTWARD ALONG THE KS/NE BORDER OUT OF NORTHEAST CO AS THE NIGHT
WEARS ON. ALTHOUGH INSTABILITY APPEARS PRETTY MINIMAL
LOCALLY...HAVE EXPANDED SLIGHT CHANCES FOR STORMS ACROSS MUCH OF
THE WESTERN HALF OF THE CWA POST-MIDNIGHT...WHILE LEAVING THE
EVENING HOURS DRY...AT LEAST FOR NOW. MADE LITTLE CHANGE OT LOW
TEMPS...WITH MID 60S MOST AREAS.
THURSDAY/THURSDAY NIGHT...POP-WISE MADE LITTLE CHANGE FROM
PREVIOUS FORECAST WITH A BROAD COVERAGE OF 30 POPS AND SOME 40S-
50S MAINLY FOCUSED IN SOUTHERN ZONES. ALOFT...ITS THE SAME OLD
THEME...WITH SUBTLE EMBEDDED SHORTWAVE TROUGHS WORKING OVER OR NEAR
THE CWA IN NORTHWEST FLOW...WHILE A STRONGER SHORTWAVE TROUGH
DROPS OUT OF CANADA INTO THE NORTHERN MN AREA. NOT
SURPRISINGLY...MODEL QPF FIELDS ARE OVER THE PLACE...WITH THE
ECMWF HITTING THE DAYTIME HOURS A LITTLE HARDER AND THE GFS THE
NIGHT. TEMP-WISE...WITH A RETURN TO MORE SOUTHERLY WINDS...NUDGED
UP HIGH TEMPS A LITTLE FROM PREVIOUS PER MET/MAV GUIDANCE BLEND...BUT
STILL ONLY MID 80S IN MOST AREAS.
FRIDAY/FRIDAY NIGHT...CONTINUED 20-30 POPS CWA-WIDE THIS ENTIRE
TIME...ALTHOUGH LARGE SCALE SUPPORT WANES A BIT FRIDAY NIGHT AS
THE AFOREMENTIONED GREAT LAKES REGION SHORTWAVE TROUGH CLOSES OFF
AND STARTS TO SLOWLY EDGE FARTHER EAST. IN THE WAKE OF A PASSING
COLD FRONT AND RETURN TO NORTHEAST BREEZES...HAVE HIGHS BACK DOWN
IN THE LOW 80S MOST NEB ZONES...AND MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...CAME VERY CLOSE TO LEAVING THE CWA VOID
OF THUNDERSTORM MENTION DURING THE DAY PER PREVIOUS FORECAST...BUT
WENT AHEAD AND BROUGHT SOME SLIGHT POPS BACK INTO PARTS OF THE
SOUTHWEST 1/2 MAINLY PER THE 12Z ECMWF. SATURDAY NIGHT...HINTS OF
A SUBTLE SHORTWAVE TROUGH CONTINUE TO SUPPORT SLIGHT POPS AREA-
WIDE. HIGH TEMPS SATURDAY AGAIN LOW-MID 80S.
SUNDAY/SUNDAY NIGHT...THE LARGE-SCALE FLOW STARTS TO TURN
LEGITIMATELY MORE ZONAL VERSUS NORTHWESTERLY...IN THE WAKE OF THE
GREAT LAKES CLOSED LOW LIFTING BACK NORTHEAST INTO CANADA...BUT
THE TRAIN OF LOW AMPLITUDE DISTURBANCES INTO THE CENTRAL PLAINS
CONTINUES...AND HAVE SLIGHT POPS IN NEARLY ALL AREAS DURING THE
DAY...FOLLOWED BY 30-40 POPS SUNDAY NIGHT.
MONDAY/MONDAY NIGHT...CONTINUED QUASI-ZONAL FLOW WITH EMBEDDED
DISTURBANCES...AND HAVE AT LEAST SLIGHT POPS THROUGHOUT THIS 24
HOURS ALL AREAS...AND HIGHER VALUES CURRENTLY FOCUSED DURING THE
DAY. TEMP-WISE...LOW 80S NORTHEAST TO NEAR 90 SOUTHWEST.
TUESDAY...HAVE KEPT IT DRY FOR NOW...BUT ITS NO GUARANTEE TO STAY
THAT WAY...AS THERE IS OVERALL LITTLE CHANGE IN THE PATTERN.
POSSIBLY IN RESPONSE TO CLIMATOLOGY CARRYING MORE WEIGHT WITH
MODEL GUIDANCE AT THIS TIME RANGE...HIGHS TUESDAY ARE PRELIMINARILY
ADVERTISED TO BE A TOUCH WARMER THAN PREVIOUS DAYS...WITH MID 80S
NORTHEAST TO LOWER 90S SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1200 PM CDT TUE JUL 23 2013
HIT OR MISS SHOWERS OR A STORM OR TWO WILL BE IN THE VCNTY OF KGRI
THRU THE AFTN...WITH CHCS DIMINISHING DURING THE EVENING/TONIGHT.
WINDS WILL GENERALLY BE FROM A NORTHEASTERLY DIRECTION AND MODELS
SUGGEST POTENTIAL FOR SOME LOW CLOUDS TONIGHT/EARLY WED NEAR OR
SOUTH OF KGRI AND INCLUDED SCATTERED MVFR CLOUDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
354 AM CDT TUE JUL 23 2013
.SYNOPSIS...
ISSUED AT 353 AM CDT TUE JUL 23 2013
A WEAK COLD FRONT EXTENDS FROM NEAR THE NEBRASKA/KANSAS BORDER THEN
NORTHWEST THROUGH THE NEBRASKA PANHANDLE. A SMALL MCS MOVING INTO
CENTRAL NEBRASKA. RAINFALL AMOUNTS AT THEDFORD AND BROKEN BOW HAVE
BEEN AROUND A HALF INCH. OUTFLOW WINDS AHEAD OF THE SYSTEM HAVE
GUSTED TO AS HIGH AS 40 MPH. BROAD OUTFLOW FROM THIS SMALL MCS
EXTENDS THROUGH KIMBALL...IMPERIAL...LEXINGTON AND ORD. ANOTHER
BATCH OF SHOWERS AND THUNDERSTORMS EXITING THE BLACK HILLS NOW
NEARLY INTO CHERRY COUNTY. RECENT CLOUD TOPS AND LIGHTNING STRIKE
COUNTS HAVE BEEN NEAR STEADY STATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CDT TUE JUL 23 2013
ONGOING CONVECTION IN NORTH CENTRAL NEBRASKA WILL CONTINUE TO MOVE
INTO CENTRAL NEBRASKA THIS MORNING. A FEW WEAK DISTURBANCES UPSTREAM
IN WESTERN SOUTH DAKOTA AND EASTERN MONTANA WILL CONTINUE THE
POSSIBILITY FOR AT LEAST A SLIGHT CHANCE FOR ALL AREAS EXCEPT THE
WEST CENTRAL AND SOUTHWEST COUNTIES. MOST...IF NOT ALL THE ACTIVITY
MAY END BY EARLY AFTERNOON. HIGHS BEHIND THE FRONT TODAY TO BE
COOLER RANGING FROM THE UPPER 70S NORTHEAST TO NEAR 90 FAR
SOUTHWEST. AS THE COLD FRONT CONTINUES TO PUSH SOUTHWEST...THE FOCUS
FOR THUNDERSTORMS WILL BE MAINLY ACROSS CENTRAL KANSAS BY THIS
EVENING...AND POSSIBLY THE FRONT RANGE. KEPT A SLIGHT CHANCE IN FOR
THE EASTERN PANHANDLE EARLY THIS EVENING AND FOR FRONTIER COUNTY IN
SOUTHWEST NEBRASKA. OTHERWISE SKIES TO BE MOSTLY CLEAR OVERNIGHT
WITH LIGHT AND VARIABLE WINDS. LOWS UPPER 50S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 353 AM CDT TUE JUL 23 2013
THE MAIN FOCUS IN THE EXTENDED PERIODS CONTINUES TO BE
PRECIPITATION CHANCES...WHICH REMAIN PROBLEMATIC GIVEN THE LOW RUN
TO RUN CONSISTENCY WITH THE PERTURBATIONS THAT ARE SHOWN TO CROSS
THE REGION. THERE IS HOWEVER INCREASING CONFIDENCE WEDNESDAY INTO
THURSDAY OF A SYSTEM BRINGING RAINFALL...POSSIBLY
WIDESPREAD...BACK ACROSS MUCH OF WESTERN AND SOUTHWEST NEBRASKA.
WITH NORTHWESTERLY FLOW ALOFT IN PLACE AND A SURFACE TROUGH TO OUR
WEST...STORMS SHOULD INITIATE OFF THE HIGHER TERRAIN OF EASTERN
WYOMING DURING THE AFTERNOON HOURS WEDNESDAY...AND THEN SHIFT OFF
TO THE SOUTHEAST THROUGH THE EVENING AND INTO THE OVERNIGHT. A
MODEST LOW LEVEL JET DOES DEVELOP OVER THE CENTRAL PLAINS...WHICH
WOULD HELP MAINTAIN ANY COMPLEX OF STORMS THAT SHOULD DEVELOP.
THERE/S DISAGREEMENT HOWEVER IN HOW FAR EAST THE POTENTIAL LATE
NIGHT COMPLEX WILL MOVE...WITH THE EC DROPPING THE MCS THROUGH
NORTHEAST COLORADO INTO WESTERN KANSAS. THE GFS IS A BIT MORE
OPTIMISTIC /FURTHER EAST/ WITH RAIN CHANCES FOR SOUTHWESTERN
PORTIONS OF THE CWA OVERNIGHT WEDNESDAY/THURSDAY MORNING. WITH THE
UNCERTAINTY...WILL LIMIT POPS TO 40 PERCENT OR LESS FOR LOCATIONS
WEST OF HIGHWAY 83...WITH THE HIGHEST PROBABILITIES ACROSS
SOUTHWEST NEBRASKA...I.E. NEAR IMPERIAL. RAIN CHANCES CONTINUE
INTO FRIDAY AND THROUGH THE EXTENDED AS THE UPPER PATTERN
UNDERGOES A TRANSITION FROM NORTHWESTERLY TO ZONAL. ADDITIONAL
DISTURBANCES ARE SHOWN TO PASS THROUGH THE TRANSITIONING
FLOW...BUT REMAIN DIFFICULT TO TRACK/TIME AT THIS JUNCTURE...THUS
WILL LIMIT POPS BEYOND 00Z SATURDAY AT 25 PERCENT OR LESS UNTIL
HIGHER CONFIDENCE IS NOTED.
AS FOR TEMPERATURES...THANKS TO THE EXPECTED CLOUDS...PRECIPITATION...AND
A COLD FRONT...TEMPERATURES SHOULD COOL BACK INTO THE LOW TO MID
80S THURSDAY AND BEYOND FOR MOST LOCATIONS. THE WARMEST READINGS
WILL ONCE AGAIN BE CONFINED TO OUR FAR WEST...AS WEAK WAA PUSHES
EAST OFF THE HIGH PLAINS...MID TO UPPER 80S COULD RETURN TO THE
AREA BY EARLY NEXT WEEK. THE WARMEST DAY OF THE EXTENDED PERIOD IS
EXPECTED WEDNESDAY IN ADVANCE OF THE SHORTWAVE AND COLD
FRONT...WIDESPREAD READINGS IN THE MID TO UPPER 80S ARE
ANTICIPATED. LOWS SHOULD REMAIN SEASONAL THROUGH THE PERIOD...60S
SHOULD BE THE NORM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1108 PM CDT MON JUL 22 2013
BOTH THE HRRR AND RAP MODELS SUGGEST THE ONGOING CONVECTION ACROSS
NWRN NEB WILL SPREAD EAST TONIGHT...SQIRTING KLBF...AND MOVING
MOSTLY EAST THROUGH KVTN...KANW AND KONL. THE CONVECTION IS
EXPECTED TO WEAKEN TOWARD 12Z AROUND KANW BUT COULD LINGER ACROSS
KONL THROUGH 18Z TUESDAY. VFR IS EXPECTED AT KLBF FOR THE NEXT 24
HR WITH JUST AN ISOLATED TSTM POTENTIAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1111 PM CDT MON JUL 22 2013
.SYNOPSIS...
ISSUED AT 340 PM CDT MON JUL 22 2013
SEVERAL BOUNDARIES ARE ACROSS THE HIGH PLAINS THIS AFTERNOON. A COOL
FRONT CONTINUES TO PUSH EAST...ACROSS EASTERN NEB...WITH
THUNDERSTORMS STARTING TO FIRE ACROSS NW IOWA AND INTO EASTERN NEB.
A SECONDARY...NEARLY STATIONARY...BOUNDARY EXISTS ACROSS THE SE
PANHANDLE INTO SW NEB. WINDS ON THE NORTH SIDE OF THE BOUNDARY ARE
OUT OF THE NORTH TO NORTHEAST AND SOUTHERLY TO THE SOUTH WINDS. A
THIRD BOUNDARY EXTENDS FROM THE NORTHERN PANHANDLE ACROSS CHERRY
COUNTY CURVING INTO CENTRAL NEB...WITH A LINE OF MID LEVEL CLOUDS.
TEMPS THIS AFTERNOON RANGE FROM THE MID 80S UNDERNEATH THE CLOUDS
ACROSS THE NORTH TO THE MID 90S ACROSS SW NEB.
&&
.UPDATE...
ISSUED AT 702 PM CDT MON JUL 22 2013
A LOOK AT THE HRRR MODEL FORECAST STORM MOTIONS ON THE SYSTEM
ACROSS NERN WY/WRN SD AND 850 MB MOISTURE ADVECTIONS IN THE RAP
MODEL SUGGEST THE DEVELOPING MCS UP NORTH COULD TURN SOUTH AND
SWEEP THE FCST ONCE IT MOVES EAST OF THE BLACK HILLS LATER THIS
EVENING. THE FORECAST HAS BEEN UPDATED FOR SCATTERED THUNDERSTORMS
OVERNIGHT THROUGH TUESDAY MORNING. THE HRRR SUGGESTS NORTH PLATTE
MIGHT BE THE WRN EDGE OF THE TSTM COMPLEX. THE FORECAST SHIFTS
THIS WEST A BIT TO NEAR OGALLALA.
GIVEN THE SHEAR PROFILES AND FCST STORM MOTION OF 10 KTS OR
LESS...WE WOULD LIKELY SEE A COLD POOL DRIVEN OUTFLOW DOMINANT RAIN
MAKER WITH GUSTY WINDS AND ISOLATED LARGE HAIL OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013
TONIGHT WITH THE NUMEROUS BOUNDARIES ACROSS THE AREA...EXPECT A
COUPLE DIFFERENT AREAS OF THUNDERSTORMS. DECENT CU FIELD ACROSS
GARDEN COUNTY AND CAP HAS ERODED...WHILE GOOD CAPE. LIKELY GOING TO
SEE SOME STORMS DEVELOP OVER THE NEXT HOUR OR TWO...WITH MOVEMENT TO
THE SE. A SECOND AREA OF SHOWERS EXPECTED ACROSS THE FAR N...NEAR
THE S DAKOTA BORDER WITH THE AID OF AN UPPER LEVEL WAVE. THIS SHOULD
DIVE TOWARDS CENTRAL NEB.
BY TOMORROW MORNING FOCUS SHOULD BE THE STALLED MID LEVEL BOUNDARY
ACROSS NW INTO CENTRAL NEB. MODELS CONTINUE TO SHOW REDEVELOPMENT TO
THE NW...SIMILAR TO THIS MORNING...THEN DRIFTING SE. MODELS IN GOOD
AGREEMENT ALLOWING SOME MOISTURE TO POOL ALONG THE BOUNDARY AS PWATS
INCREASE TO AROUND 1.50 INCHES...AND SHOULD BE ENOUGH TO GET ISOLD
LATE MORNING AND EARLY AFTERNOON SHOWERS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM CDT MON JUL 22 2013
UNSETTLED PERIOD EXPECTED...WITH SEVERAL UPPER LEVEL WAVES
FORECASTED TO ROTATE EAST ACROSS THE REGION ON NORTHERN PERIPHERY OF
SOUTHERN PLAINS UPPER LEVEL RIDGE. THE STRONGEST OF THESE SYSTEMS IS
FORECASTED TO ARRIVE THURSDAY INTO THURSDAY NIGHT...AND THIS PERIOD
WILL BE OUR BEST CHANCE FOR RAIN. MODELS HAVE STRUGGLED SLIGHTLY ON
EXACTLY WHERE THE NEXT FOCUS WILL BE...AND FOR THIS REASON WILL
LEAVE POPS CAPPED AT 40 PERCENT AT THIS TIME. LATER MODEL RUNS WILL
HELP DETERMINE WHERE THE HIGHER POPS /IF WARRANTED/ WILL BE
PLACED.
AFTER THE THURSDAY/THURSDAY NIGHT SYSTEM...STILL A SLIGHT CHANCE FOR
MORE RAIN INTO THE WEEKEND...AS WEAK WAVES CONTINUE TO CROSS THE
AREA. VERY HARD TO PIN DOWN EXACT TIMING AND LOCATION AT THIS
POINT...SO WILL ONLY KEEP CHANCES SLIGHT AT THIS TIME. THE OTHER
STORY WILL BE THE TEMPERATURES. A STRONG AREA OF LOW PRESSURE IS
EXPECTED TO FORM ACROSS SOUTHEAST CANADA FRIDAY INTO THE
WEEKEND...AND THIS SHOULD PUSH A FAIRLY STRONG COLD FRONT SOUTHWEST
INTO THE AREA. LOOKS LIKE THE FRONT WILL STALL IN CENTRAL
NEBRASKA...SO THE COOLER READINGS...WITH HIGHS AROUND 80...WILL BE
FOUND ALONG AND NORTHEAST OF A BROKEN BOW TO AINSWORTH LINE. AREAS
SOUTHWEST SHOULD GENERALLY SEE HIGHS IN THE 80S. HUMIDITY WILL ALSO
BE SCOURED OUT SOME...SO CONDITIONS LOOKING PLEASANT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1108 PM CDT MON JUL 22 2013
BOTH THE HRRR AND RAP MODELS SUGGEST THE ONGOING CONVECTION ACROSS
NWRN NEB WILL SPREAD EAST TONIGHT...SQIRTING KLBF...AND MOVING
MOSTLY EAST THROUGH KVTN...KANW AND KONL. THE CONVECTION IS
EXPECTED TO WEAKEN TOWARD 12Z AROUND KANW BUT COULD LINGER ACROSS
KONL THROUGH 18Z TUESDAY. VFR IS EXPECTED AT KLBF FOR THE NEXT 24
HR WITH JUST AN ISOLATED TSTM POTENTIAL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CDC
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
318 PM PDT TUE JUL 23 2013
.SYNOPSIS...MONSOON MOISTURE IS IMPACTING NEVADA TODAY AND
TOMORROW PROVIDING INCREASING CLOUDS...ENHANCED CHANCES FOR
THUNDERSTORMS. THUNDERSTORMS ARE LIKELY ACROSS CENTRAL NEVADA THIS
AFTERNOON AND EVENING WHERE SOME WILL PRODUCE HEAVY RAINFALL. MORE
CONVECTION IS POSSIBLE TOMORROW AFTERNOON.
&&
.SHORT TERM...THIS AFTERNOON THROUGH THURSDAY. A REMNANT UPPER
LOW OVER THE SILVER STATE AND DEEP MOISTURE NEARING 200 PERCENT OF
NORMAL NEAR LAS VEGAS ARE NEARLY COINCIDENT WITH VISIBLE SATELLITE
IMAGERY SHOWING CUMULUS CLOUDS. THE MOISTURE ALONG WITH DIFFERENTIAL
HEATING ZONES...WILL LEND ITSELF TOWARDS RIPE CONVECTION. THE
RADAR HAS ALREADY PINGED INTO A NUMBER OF THUNDERSTORMS TODAY
WHICH IS CONSISTENT WITH THE NAM12 AND THE HRRR FOR ENHANCED CAPE
AND LIFTED INDICES. MORE THUNDERSTORMS EXPECTED TOMORROW
AFTERNOON.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. THE MODELS ARE IN
FAIRLY GOOD AGREEMENT THROUGH TUESDAY. THE GENERAL SCENARIO IS FOR
ABOVE-NORMAL TEMPERATURES TO CONTINUE. THE RIDGE OF HIGH PRESSURE
RESPONSIBLE FOR THE LATEST STRING OF VERY WARM TEMPERATURES WILL
REMAIN STRONG THROUGH EARLY FRIDAY THEN BEGIN TO GET SUBDUED BY THE
INFUSION OF A LOW PRESSURE SYSTEM CROSSING EAST ACROSS THE SIERRAS
FOLLOWED BY A STRONGER UPPER LOW MOVING SOUTH FROM THE PACIFIC
NORTHWEST REGION. THE UPPER LOW WILL SLOWLY BEAR DOWN AND FLATTEN
THE RIDGE BY THE WEEKEND. SOME DAYTIME TEMPERATURES WILL FALL INTO
THE 80S OVER THE WEEKEND AND INTO EARLY NEXT WEEK. MODELS ARE
INDICATING A VERY UNSTABLE AIR MASS OVER CENTRAL NEVADA FOLLOWING
THE SURGE OF MOISTURE EXPECTED TODAY AND TOMORROW. DOWNDRAFT CAPE
VALUES SOUTH OF HIGHWAY 50 ARE GREATER THAN 1500 J/KG THROUGH
SATURDAY. PRECIPITABLE WATER VALUES ARE APPROACHING ONE INCH SOUTH
OF HIGHWAY 50. THE PROSPECT OF FLASH FLOODING FROM THUNDERSTORM
TRAINING ACROSS CENTRAL NEVADA MAY LINGER THROUGH SATURDAY DUE TO
THE LIGHT WINDS ALOFT...ESPECIALLY OVER THE RECENT BURN AREAS OF
NORTHERN NYE AND WHITE PINE COUNTIES...SPECIFICALLY THE WHITE PINE
FIRE AND THE BLACK FIRE. HUMBOLDT COUNTY WILL SEE THE LEAST AMOUNT
OF THUNDERSTORM ACTIVITY THROUGHOUT THE LONG TERM PERIOD AND
OVERNIGHT THUNDERSTORMS WILL BE PRIMARILY CONFINED TO THE SOUTHERN
HALF OF THE FORECAST AREA THROUGH FRIDAY NIGHT...THEN THE EASTERN
HALF SATURDAY AND SUNDAY AS A SHORTWAVE LOW TO THE NORTH NUDGES THE
MOISTURE AXIS EAST. THE SHOW MAY BE OVER BY TUESDAY AS THE
DEVELOPING PACIFIC TROUGH PROMISES TO SCOUR THE MOISTURE OUT OF THE
GREAT BASIN.
&&
.AVIATION...VFR CONDITIONS CAN BE EXPECTED THROUGH WEDNESDAY.
THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KELY AND KTPH THROUGH
EARLY THIS EVENING. ISOLATED THUNDERSTORMS MAY AFFECT KELY AND KTPH
OVERNIGHT. THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KWMC KEKO
KELY AND KTPH WEDNESDAY AFTERNOON AS THE MOISTURE FLUX INCREASES
ACROSS THE NORTH. BRIEF HEAVY RAINS AND STRONG GUSTY WINDS ARE
POSSIBLE WITH THESE STORMS.
&&
.FIRE WEATHER...A VERY UNUSUAL PATTERN HAS BEEN IN PLACE FOR THE
PAST TWO WEEKS. THIS UPPER LEVEL DISTURBANCE THAT IS CURRENTLY
OVER THE WESTERN GREAT BASIN...ORIGINALLY CAME FROM THE
MIDWEST...AKA...BACK EAST...WHERE A STRONG HIGH DEVELOPED CAUSING
THIS LOW TO RETROGRADE. THE SYSTEM HAS TAPPED INTO A FETCH OF MONSOON
MOISTURE. THE PWS OVER LAS VERY WERE ALMOST 200 PERCENT OF
NORMAL FROM THIS MORNINGS 12Z SOUNDING...REAL DATA NOT MODEL DATA.
TAKING THE GENESIS OF THIS PATTERN IN COMBINATION WITH AN UNSTABLE AIR
MASS WILL RESULT IN SCATTERED TO NUMEROUS THUNDERSTORMS CAPABLE OF
PRODUCING HEAVY RAIN ACROSS MUCH OF CENTRAL NEVADA. STORMS WILL BE
SLOW MOVING AND MAY TREK OVER THE SAME LOCATIONS...RESULTING IN
ENHANCED RAINFALL AMOUNTS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR NORTHEASTERN NYE
COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
109 PM EDT TUE JUL 23 2013
.SYNOPSIS...
A PAIR OF COLD FRONTS...ONE PASSING THROUGH TODAY AND ANOTHER
TONIGHT...WILL PRODUCE ADDITIONAL SCATTERED SHOWERS AND PERHAPS
ISOLATED THUNDERSTORMS. MUCH COOLER AND DRIER WEATHER WILL SETTLE
IN FOR WEDNESDAY AND THURSDAY COURTESY OF CANADIAN HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...
PRECIPITABLE WATER VALUES ARE QUICKLY DECREASING...WITH MAIN UPPER
WAVE NOW HEADING EAST AND TAKING THE DEEPER MOISTURE WITH IT. WE
ARE NOW IN UNFAVORABLE LEFT ENTRANCE REGION OF JET AS WELL...SO
CURRENTLY ONLY A FEW SCATTERED SHOWERS IN ITS WAKE. LOOSELY-
DEFINED SURFACE LOW AND FRONTAL BOUNDARY WILL BE SHIFTING ITS WAY
THROUGH THE AREA THE REMAINDER OF TODAY...PROVIDING SOME HELP TO
CURRENT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS...BUT OTHERWISE
FACTORS ABOVE WILL HINDER DEVELOPMENT AND MUCH OF THE AREA WILL BE
DRY THIS AFTERNOON. GRIDS UPDATED ACCORDINGLY. WE WILL NEED TO WATCH
THE LOCALIZED AREAS THAT RECEIVED HEAVY RAINFALL IN THE LAST 18
HOURS JUST IN CASE...BUT AT THIS POINT NOT EXPECTING WATER
PROBLEMS.
OVERNIGHT TONIGHT...SECONDARY COLD FRONT IN TANDEM WITH WAVE ALOFT
WILL PROBABLY YIELD A BAND OF ADDITIONAL SCATTERED SHOWERS.
DETAILS IN POPS HAVE BEEN ADJUSTED FOR TIMING OF THIS
FEATURE...BUT THERE IS UNCERTAINTY TO HOW MUCH COVERAGE BECAUSE OF
THE LOWER PWATS AND DIURNALLY UNFAVORABLE TIMING. THERE MAY BE
SIGNIFICANT GAPS BETWEEN INDIVIDUAL SHOWERS.
PREVIOUS DISCUSSION...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.
THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.
SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
LONG STORY SHORT...LARGE CANADIAN HIGH PRESSURE BUILDS IN WITH DRY
AND COOL AIR MASS. THIS WILL INCLUDE THE COOLEST TEMPERATURES OF
JULY 2013 BY EARLY THURSDAY MORNING.
ON THE FRONT EDGE OF THE BUILDING HIGH...SOME LOW LEVEL MOISTURE
WILL BE TRAPPED UNDER DEVELOPING SUBSIDENCE INVERSION EARLY
WEDNESDAY. GIVEN THE FAIRLY SHALLOW NATURE OF IT...EXPECTING
CLOUDS AND PERHAPS A COUPLE SPRINKLES FOR A TIME EARLY WEDNESDAY
MORNING...BEFORE VERY DRY AIR MASS BECOMES FULLY REALIZED LATE
MORNING THROUGH WEDNESDAY AFTERNOON...ERADICATING CLOUDS VIA COLD
AIR ADVECTION AND MIXING DOWN OF VERY DRY AIR FROM MID LEVELS.
PRECIPITABLE WATER VALUES DIVE TO LESS THAN A HALF INCH BY LATE
WEDNESDAY AFTERNOON. THIS IS NEARLY 2 STANDARD DEVIATIONS BELOW
NORMAL FOR JULY. EXCEPT FOR PERHAPS THE LOWEST ELEVATIONS OF
DELAWARE VALLEY IN PIKE COUNTY PA...HIGHS WEDNESDAY SHOULD BE
LIMITED TO UPPER 60S TO MID 70S FOR CNY AND 70S FOR NEPA.
THE COOL FRESH DAY WITH NORTHWEST WINDS GUSTING TO 15-20 MPH...WILL
BE FOLLOWED BY QUICK DECOUPLING OF WINDS WEDNESDAY NIGHT AS CENTER
OF HIGH SHIFTS FROM WESTERN GREAT LAKES TO EASTERN GREAT
LAKES/QUEBEC/ONTARIO. RADIATIONAL COOLING WILL EASILY YIELD THE
COOLEST NIGHT OF THIS MONTH...UPPER 40S TO MID 50S...COOLEST IN
SHELTERED VALLEYS OF THE TWIN TIERS AND WESTERN CATSKILLS AND
MOHAWK VALLEY. CAVEAT ON THIS IS THAT WITH 850MB TEMPERATURES OF
ONLY 6-8 DEGREES CELSIUS...WE MAY ACTUALLY GET SOME LAKE EFFECT
CLOUDS COMING FROM LAKE ONTARIO TO SOME PARTS OF FINGER LAKES AND
CENTRAL SOUTHERN TIER REGIONS. TEMPERATURES WILL BE VERY SENSITIVE
TO RADIATIONAL COOLING SET UP AND THUS CLOUD LAYER DETAILS.
HIGH PRESSURE CENTER WILL TRAVEL ROUGHLY DOWN THE SAINT LAWRENCE
SEAWAY THURSDAY...THEN TO CANADIAN MARITIME PROVINCES FRIDAY...YET
OVERALL THE HIGH PRESSURE WILL REMAIN DOMINANT OF OUR WEATHER. I
WAS ABLE TO REMOVE LINGERING SLIGHT CHANCE OF A SHOWER THAT WAS IN
OUR FAR SOUTHEASTERN ZONES THURSDAY. BY FRIDAY...SOME EASTERLY LOW
LEVEL FLOW UNDER THE HIGH COULD POTENTIALLY ATTEMPT TO BRING IN
MARINE LAYER MOISTURE AGAINST THE POCONOS/CATSKILLS...SO I PLACE
A SLIGHT CHANCE OF A SHOWER THERE BUT OTHERWISE STILL DRY
AREAWIDE. OVERALL...AT LEAST A SURFACE RIDGE WILL KEEP CONTROL FOR
MOST OF THE REGION. HIGHS FRIDAY BACK UP TO NEAR CLIMATOLOGY...YET
WITH DEWPOINTS STILL VERY COMFORTABLE IN THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.
.OUTLOOK...
WED/THU/...VFR
FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP/MDP
NEAR TERM...DJP/MDP
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1019 AM EDT TUE JUL 23 2013
.SYNOPSIS...
A PAIR OF COLD FRONTS...ONE PASSING THROUGH TODAY AND ANOTHER
OVERNIGHT TONIGHT...WILL PRODUCE ADDITIONAL SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS. MUCH COOLER AND DRIER WEATHER
WILL SETTLE IN FOR WEDNESDAY AND THURSDAY COURTESY OF CANADIAN
HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...
PRECIPITABLE WATER VALUES ARE QUICKLY DECREASING...WITH MAIN UPPER
WAVE NOW HEADING EAST AND TAKING THE DEEPER MOISTURE WITH IT. WE
ARE NOW IN UNFAVORABLE LEFT ENTRANCE REGION OF JET AS WELL...SO
CURRENTLY ONLY A FEW SCATTERED SHOWERS IN ITS WAKE. LOOSELY-
DEFINED SURFACE LOW AND FRONTAL BOUNDARY WILL BE SHIFTING ITS WAY
THROUGH THE AREA THE REMAINDER OF TODAY...PROVIDING SOME HELP TO
CURRENT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS...BUT OTHERWISE
FACTORS ABOVE WILL HINDER DEVELOPMENT AND MUCH OF THE AREA WILL BE
DRY THIS AFTERNOON. GRIDS UPDATED ACCORDINGLY. WE WILL NEED TO WATCH
THE LOCALIZED AREAS THAT RECEIVED HEAVY RAINFALL IN THE LAST 18
HOURS JUST IN CASE...BUT AT THIS POINT NOT EXPECTING WATER
PROBLEMS.
OVERNIGHT TONIGHT...SECONDARY COLD FRONT IN TANDEM WITH WAVE ALOFT
WILL PROBABLY YIELD A BAND OF ADDITIONAL SCATTERED SHOWERS.
DETAILS IN POPS HAVE BEEN ADJUSTED FOR TIMING OF THIS
FEATURE...BUT THERE IS UNCERTAINTY TO HOW MUCH COVERAGE BECAUSE OF
THE LOWER PWATS AND DIURNALLY UNFAVORABLE TIMING. THERE MAY BE
SIGNIFICANT GAPS BETWEEN INDIVIDUAL SHOWERS.
PREVIOUS DISCUSSION...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.
THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.
SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.
850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.
HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.
.OUTLOOK...
WED/THU/...VFR
FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP/MDP
NEAR TERM...DJP/MDP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
640 AM EDT TUE JUL 23 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
620 AM UPDATE...
UPDATED MORNING POP GRIDS. MAJORITY OF PRECIP WITH FIRST WAVE HAS
MOVED NORTHEAST OF FA, WITH SCATTERED LIGHT SHOWERS LEFT OVER TO
THE SOUTHWEST. THIS COVERAGE IS FORECAST THROUGH MOST OF THE
MORNING, WITH ACTIVITY PICKING UP AHEAD OF AFTERNOON COLD FRONT.
3 AM UPDATE...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.
THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.
SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.
850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.
HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
WV MVG OUT THIS MRNG AND TAKING THE STEADY RAIN WITH IT. ISLTD
SHWRS WITH LINGERING LWRD CIGS AND VSBYS PSBL FOR A FEW HRS THIS
MRNG. LTR TODAY...LIMITED INSTABILITY WILL RESULT IN ISLTD
SHWRS...BUT NOT ENUF CVRG FOR INCLUSION IN THE TAFS ATTM. SO...
XPCT GNRL VFR CONDS WITH VFR CIGS THRU THE DAY INTO THE NGT. LATE
IN THE PD...COLD FNT WILL PASS THRU THE AREA INCRSG WINDS BUT ONCE
AGAIN CVRG OF PCPN WILL BE LIMTED DUE TO THE LATE NIGHT FNTL
PASSAGE.
.OUTLOOK...
WED/THU/...VFR
FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
624 AM EDT TUE JUL 23 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
620 AM UPDATE...
UPDATED MORNING POP GRIDS. MAJORITY OF PRECIP WITH FIRST WAVE HAS
MOVED NORTHEAST OF FA, WITH SCATTERED LIGHT SHOWERS LEFT OVER TO
THE SOUTHWEST. THIS COVERAGE IS FORECAST THROUGH MOST OF THE
MORNING, WITH ACTIVITY PICKING UP AHEAD OF AFTERNOON COLD FRONT.
3 AM UPDATE...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.
THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.
SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.
850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.
HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHRT WV ACTING ON DEEP MOISTURE BRINGING WIDESPREAD RAIN AND GNRL
MVFR CIGS AND VSBYS...WITH BRIEF IFR AT TIMES. WV WILL MVE EAST
THIS MRNG AND CLR THE AREA ARND OR SHRTLY AFT 12Z. THIS WILL ALLOW
SLOWLY IMPRVG CONDS THRU THE DAY TODAY AND A RETURN TO VFR AS
DRIER AIR MVES IN. VFR CONDS SHD CONT THRU THE END OF THE PD.
.OUTLOOK...
LATE TUE NGT...SCATTERED MVFR SHRA.
WED/THU/...VFR
FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
309 AM EDT TUE JUL 23 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ADDITIONAL SHOWERS, AND A FEW
THUNDERSTORMS TO NY AND PA TODAY AND THIS EVENING. PLEASANTLY COOLER
AND DRIER WEATHER WILL SETTLE IN FOR WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL SYSTEM WILL SLIDE EASTWARD TODAY, TAKING HIGHER PWATS
EAST OF FA. HOWEVER A COLD FRONT WILL SLIDE INTO NY AND PA TO SPUR
ADDITIONAL CONVECTION.
THE STRATIFORM RAIN CURRENTLY OVER FA WILL DIMINISH IN COVERAGE
AND SLIDE NORTHEAST TOWARD SUNRISE, AS FORECAST BY THE PREVIOUS
FEW HRRR RUNS. SKIES WILL BE MAINLY CLOUDY, THOUGH THERE IS POTENTIAL
FOR A FEW BREAKS OVER THE CENTRAL SOUTHERN TIER WHERE TEMPS MAY
PUSH INTO THE LOWER 80S.
SHOWERS AND A FEW THUNDERSTORMS WILL RETURN WITH THE COLD FRONT.
LACK OF WINDS AND MODEST INSTABILITY SUGGEST NO SVR THREAT. WILL
NEED TO MONITOR HEAVY RAINERS OVER AREAS WHICH RECEIVED COPIOUS
RAIN ON MONDAY. THESE ARE ISOLATED PROBLEMS, SO WILL NOT BE
ISSUING A FLASH FLOOD WATCH PER COORDINATION WITH NEIGHBORING
OFFICES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
COLD FRONT WILL SCOUR OUT REMAINING MOISTURE THIS EVENING, WITH
PRECIP GRADUALLY ENDING OVERNIGHT. HIGH PRESSURE WILL FOLLOW IN
ITS WAKE, BRINGING STRONG DOWNWARD MOTION AND AN UNSEASONABLY COOL
AIRMASS.
850MB TEMPS PROGGED AROUND 8C FOR WEDNESDAY INTO EARLY THURSDAY.
WITH MOSTLY SUNNY SKIES, THIS SHOULD YIELD MAX TEMPS MAINLY IN THE
70S ON WEDNESDAY WITH A FEW 80S POSSIBLE FROM THE CENTRAL SOUTHERN
TIER DOWN INTO PA. OVERNIGHT MINS WILL DIP INTO THE LOW AND MIDDLE
50S...THE COOLEST TEMPS WE HAVE WITNESSED IN JULY 2013. A FEW
READINGS IN THE UPPER 40S ARE FORECAST IN THE SHELTERED RURAL
VALLEYS.
HIGH PRESSURE WILL REMAIN IN CONTROL INTO THURSDAY, THOUGH MODELS
SUGGEST POTENTIAL FOR SOME RETURN FLOW INTO OUR FAR SERN COUNTIES
LATE IN THE PERIOD WHERE WE HAVE ADDED A SLIGHT CHANCE FOR A
SHOWER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
3 PM MON UPDATE...
AN UNSETTLED WEATHER PATTERN IS EXPECTED ACROSS THE AREA AS BROAD
TROUGHING AND SW FLOW ALOFT IS EXPECTED TO SETTLE OVER THE
NORTHEAST THROUGH NEXT WEEKEND. MULTIPLE VORT MAXES WILL TRAVEL
AROUND THE BASE OF THE TROUGH AND EJECT NORTHEASTWARD RESULTING IN
A CHANCE FOR SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
EXTENDED. MODELS PROJECT A COLD FRONT MOVING INTO OUR REGION
SUNDAY WHICH WILL RESULT IN COOLER AND DRIER AIR FOR THE REGION.
AS THE DRY AIR FUNNELS IN FROM THE WEST...A BRIEF DRY PERIOD MAY
RETURN TO THE AREA.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHRT WV ACTING ON DEEP MOISTURE BRINGING WIDESPREAD RAIN AND GNRL
MVFR CIGS AND VSBYS...WITH BRIEF IFR AT TIMES. WV WILL MVE EAST
THIS MRNG AND CLR THE AREA ARND OR SHRTLY AFT 12Z. THIS WILL ALLOW
SLOWLY IMPRVG CONDS THRU THE DAY TODAY AND A RETURN TO VFR AS
DRIER AIR MVES IN. VFR CONDS SHD CONT THRU THE END OF THE PD.
.OUTLOOK...
LATE TUE NGT...SCATTERED MVFR SHRA.
WED/THU/...VFR
FRI/SAT...CHANCE OF SCATTERED MVFR SHRA/TSRA
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM/DJN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1029 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT OVER NORTHERN NORTH CAROLINA WILL MOVE SOUTH ACROSS THE
AREA LATE TONIGHT. AFTER STALLING OFFSHORE...THE FRONT WILL RETURN
NORTH OVER THE WEEKEND. ANOTHER COLD FRONT WILL APPROACH THE AREA
EARLY NEXT WEEK. UNSETTLED WEATHER IS EXPECTED FOR MUCH OF THE
PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...AN ABSOLUTELY MASSIVE REGION OF HEAVY RAIN
HAS DEVELOPED ACROSS EAST-CENTRAL NORTH CAROLINA INTO THE UWHARRIE
MOUNTAINS OF CENTRAL NORTH CAROLINA...VERY NEAR THE POSITION OF THE
SURFACE COLD FRONT. LATEST HRRR MODEL RUNS SHOW SOME OF THIS
CONVECTIVE ACTIVITY SINKING SOUTH OVER THE NEXT FEW HOURS...
AFFECTING REGIONS FROM BENNETTSVILLE AND LUMBERTON THROUGH
ELIZABETHTOWN. POPS HAVE BEEN INCREASED FOR THIS NORTHWESTERN
QUARTER OF MY FORECAST AREA (TO AS HIGH AS 70 PERCENT IN WALLACE!)
WITH LITTLE CHANGE ELSEWHERE. WITH OUR RADAR ESTIMATING A HUGE AREA
OF 1-2 INCH RAINFALL ACROSS THE PEE DEE DRAINAGE BASIN I HAVE GOT TO
IMAGINE THERE WILL BE A RESPONSE ALONG OUR PORTION OF THE RIVER IN
THE NEXT FEW DAYS. NO OTHER SIGNIFICANT CHANGES ARE NECESSARY TO THE
FORECAST. PREVIOUS DISCUSSION FROM 800 PM FOLLOWS...
IT`S A VERY INTERESTING WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S.
THIS EVENING. AN ATYPICALLY DEEP UPPER TROUGH EXTENDING ACROSS THE
GREAT LAKES INTO THE SOUTHERN APPALACHIANS IS HELPING IGNITE
CLUSTERS OF THUNDERSTORMS ALL ACROSS THE CAROLINAS. THE GREATEST
CONCENTRATION OF STORMS EXISTS ALONG A SOUTHWARD-MOVING COLD FRONT
EXTENDING FROM THE HAMPTON ROADS REGION OF VIRGINIA ACROSS
RALEIGH...ASHEBORO...CHARLOTTE...AND INTO THE SOUTHERN NC MOUNTAINS.
OTHER CLUSTER OF STORMS HAVE DEVELOPED ACROSS THE COASTAL
PLAIN...INCLUDING ONE THAT DROPPED 1.30 INCHES JUST NORTH OF
WHITEVILLE EARLIER. 0-6 KM STORM MOTION IS VERY SLOW...WITH ACTUAL
STORM MOTION DRIVEN MORE BY THE MOVEMENT OF OUTFLOW BOUNDARIES THAN
BY SYNOPTIC FLOW.
A SECOND REGION OF ENHANCED UPPER LEVEL CURVATURE IS OBSERVED IN 18Z
MODEL ANALYSIS FIELDS OFF THE SOUTH CAROLINA COAST. VISIBLE
SATELLITE AND RADAR BOTH SHOW A LOW-LEVEL SWIRL DEVELOPING BARELY 75
MILES SOUTHEAST OF MYRTLE BEACH. MODELS HAVE INITIALIZED WELL AND
FORECAST THIS FEATURE TO BECOME A FULL-BLOWN SYNOPTIC LOW AS IT
MOVES NORTHEASTWARD OVER THE NEXT TWO DAYS...POTENTIALLY ACQUIRING
WARM CORE CHARACTERISTICS AS IT MOVES ACROSS THE WARM GULF STREAM
WATERS SOUTH OF VIRGINIA. THIS LOW WILL HAVE SURPRISINGLY LITTLE
IMPACT LOCALLY AS IT MOVES EAST AND NORTHEAST OF OUR PORTION OF THE
COAST BEFORE BECOMING A SIGNIFICANT FEATURE LATER ON.
STEEP LOW LEVEL LAPSE RATES WILL STABILIZE THIS EVENING WITH THE
LOSS OF DAYTIME HEATING. SHOWERS AND T-STORMS SHOULD CONTINUE IN AN
INCREASINGLY SCATTERED FASHION ACROSS EASTERN SOUTH CAROLINA FOR THE
NEXT SEVERAL HOURS...LARGELY DISSIPATING BY MIDNIGHT. AFTER 2 A.M.
AS THE UPPER TROUGH TO OUR WEST DIGS SOUTH TO ITS MAXIMUM AMPLITUDE
A REGION OF SHOWERS AND EMBEDDED THUNDERSTORMS SHOULD DEVELOP ACROSS
CENTRAL NORTH CAROLINA EXTENDING INTO NORTHERN SOUTH CAROLINA. AT
FIRST I THOUGHT ISENTROPIC LIFT MUST BE INVOLVED TO SUPPORT THIS
AREA OF MODEL-INDICATED PRECIPITATION...BUT IT APPEARS TO DRIVEN
MORE BY JET DYNAMICS ALOFT AS A 75KT 200 MB JET STREAK MOVES
NORTHEAST OFF THE VIRGINIA COAST...PLACING CENTRAL NORTH CAROLINA
WITHIN ITS RIGHT-ENTRANCE REGION. (MOST ISENTROPIC FIELDS ACTUALLY
SHOW WEAK DOWNGLIDE ON LAYERS BETWEEN 305K-315K) SOME OF THIS
PRECIPITATION MAY SPREAD INTO THE SOUTH CAROLINA PEE DEE REGION AND
NEAR LUMBERTON LATE TONIGHT...AND I WILL SHOW AN INCREASING TREND IN
FORECAST POPS LATE.
LOWS SHOULD FALL INTO THE LOWER 70S FOR MOST AREAS...WITH 73-77
EXPECTED NEAR THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A FRONTAL BOUNDARY AND ASSOCIATED
DEVELOPED SFC LOW WILL BE SITUATED JUST ALONG THE COAST AT THE
BEGINNING OF THE SHORT-TERM. AS THE SFC LOW IS PROGGED TO QUICKLY
MOVE OFF TO THE NORTHEAST...A SLIGHT DRYING TREND WILL OCCUR ON
FRIDAY AND CONTINUE THROUGH THE REST OF THE PERIOD BEFORE
UNSETTLED SUMMERTIME WEATHER RETURNS AS EARLY AS SATURDAY MORNING.
GFS/NAM/ECMWF ARE ALL IN AGREEMENT REGARDING WELL-DEVELOPED SFC LOW
AND CORRESPONDING H5 CLOSED LOW ALONG THE FRONTAL BOUNDARY SITUATED
ACROSS THE COAST EARLY THURSDAY MORNING...THOUGH EXACT SPATIAL
LOGISTICS ARE SLIGHTLY ALTERED BETWEEN THE MODELS. OVERALL...THIS
SYNOPTIC FEATURE WILL QUICKLY PROGRESS NORTHEASTWARD ALONG THE
EASTERN SEABOARD THURSDAY MID-MORNING. THIS WILL ALLOW FOR DRY
AIR TO BEGIN ITS INFILTRATION INTO THE AREA WITH NORTH-NORTHEAST
FLOW PREVAILING BY MID MORNING THURSDAY. WITH THIS DRIER AIR AND
LACK OF SYNOPTIC FORCING BEHIND THE FRONT...PRECIP WILL LIKELY BE
MORE DRIZZLE/ISOLATED SHWRS ACROSS THE AREA THROUGH THE EARLY
AFTERNOON HOURS...TAPERING OFF WITH THE LOSS OF ANY DAYTIME
HEATING. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT EITHER.
LATEST FCST SOUNDINGS AND TIME-HEIGHT ANALYSIS ILLUSTRATE A DECENTLY
DRY DAY ON FRIDAY...THOUGH COULD NOT ENTIRELY RULE OUT AN ISOLATED
SHOWER. BERMUDA HIGH PRESSURE WILL BEGIN TO BUILD WESTWARD ON
FRIDAY...PUSHING REMNANT SFC TROUGH NEAR OUR AREA. AVAILABLE
MOISTURE IS PRETTY LOW...SO AM NOT EXPECTING MUCH IN THE WAY OF
PRECIP...BUT WILL CONTINUE WITH EARLIER TREND OF LOW POPS INTO EARLY
SATURDAY MORNING.
HIGH TEMPERATURES IN THE MID TO UPPER 80S/NEAR 90 ON THURSDAY WILL
DECREASE SLIGHTLY TO OVERALL MID TO UPPER 80S ON FRIDAY. AS FOR
LOWS...COULD POSSIBLY SEE SOME TEMPS DIP BELOW 70 DEGREES THURSDAY
NIGHT INTO FRIDAY MORNING. OTHERWISE...LOWS WILL SIT NEAR OR JUST
ABOVE 70.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...ANOMALOUSLY DEEP 5H TROUGH CENTERED NORTH
OF THE GREAT LAKES WILL SPIN AND SLOWLY FILL DURING THE
EXTENDED...CREATING PERIODS OF UNSETTLED CONDITIONS. STALLED
BOUNDARY JUST OFFSHORE AT THE START OF THE PERIOD RETURNS NORTH AS A
WEAK WARM FRONT EARLY SATURDAY...LIFTING PWATS QUICKLY FROM 1.5 TO
NEARLY 2.0 INCHES BY SATURDAY NIGHT. THIS MORE MOIST AIR COMBINED
WITH WEAK CONVERGENCE ALONG THE FRONT WILL SPAWN ISOLATED CONVECTION
DURING THE DAY...BUT SIGNIFICANT DRY AIR ALOFT WILL STILL INHIBIT
WIDESPREAD ACTIVITY SATURDAY. FURTHER MOISTENING OF THE COLUMN
OCCURS SUNDAY...WHICH COMBINED WITH AFTN HEATING...STEEPENED ML
LAPSE RATES BENEATH THE UPPER TROUGH...AND WEAK LIFT ASSOCIATED WITH
A VORT MAX MOVING ALOFT WILL TRIGGER MORE WIDESPREAD ACTIVITY ON
SUNDAY.
EARLY NEXT WEEK A COLD FRONT APPROACHES FROM THE WEST...AND WILL
BECOME STALLED EITHER BISECTING THE CWA...OR JUST WEST OF THE LOCAL
AREA. INCREASING LIFT DUE TO CONVERGENCE ALONG THIS BOUNDARY AND
DIFFLUENCE ALOFT BENEATH A STRENGTHENING 300MB JET WILL SUPPORT
SCATTERED CONVECTION EACH DAY MON-WED. ATTM IT APPEARS THE
CONVECTION WILL BE MOST WIDESPREAD DURING THE TYPICAL AFTN/EVE
HOURS...BUT THE PARAMETERS ARE IN PLACE FOR SHOWERS/TSTMS TO PERSIST
LONGER AND BE MORE WIDESPREAD THAN JUST TYPICAL SUMMERTIME
CONVECTION. SINCE THIS IS D5-7...WILL CONTINUE WITH INHERITED HIGH
CHC POP...BUT A PERIOD OF UNSETTLED WEATHER LOOKS INCREASINGLY
LIKELY NEXT WEEK.
TEMPS THROUGH THE PERIOD WILL BE AROUND CLIMO FOR HIGHS AND
LOWS...ALTHOUGH WILL LIKELY END UP JUST BELOW FOR MAX TEMPS AND JUST
ABOVE FOR MIN TEMPS DUE TO THE CLOUD COVER AND CONVECTION.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...VISIBLE SATELLITE SHOWS LARGE AREAS OF RELATIVELY STABLE
AIR OVER OUR WESTERN CWA DUE TO OUTFLOW BOUNDARIES. THIS WORKED OVER
AREA WILL BE HARD PRESSED TO RELOAD THIS EVENING AS THE WRF MODEL
WOULD SUGGEST. THINK CONVECTION OVER THE NEXT SEVERAL HOURS WILL
RESIDE MAINLY NORTH AND WEST OF THE CWA. MID AND HIGH CLOUD DEBRIS
MAY HINDER FOG FORMATION...BUT THERE SHOULD BE PATCHES OF MAINLY
MVFR FOG...PARTICULARLY INLAND. LOOK FOR A WIND SHIFT TO THE NORTH
TOWARD MORNING AS A WEAK FRONT DROPS SOUTHEAST WITH LOW PRESSURE
OFFSHORE. NORTHEAST FLOW THURSDAY WILL HELP TO KEEP AN MVFR CEILING
IN MOST OF THE MORNING. SOME LIGHT CONVECTION IS EXPECTED IN THE
AFTERNOON...LIGHT BEING THE OPERATIVE WORD GIVE THE MORE STABLE
CONDITIONS BEHIND THE FRONT.
EXTENDED OUTLOOK...ISOLATED SHOWERS/THUNDERSTORMS THROUGH THE
PERIOD...EXCEPT SCATTERED ON THURSDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM WEDNESDAY...A COUPLE OF VERY LIGHT SHOWERS ARE LEFT
ACROSS THE OFFSHORE WATERS EAST OF CAPE FEAR...BUT OTHERWISE THE
RADAR PICTURE IS QUIET OVER THE COASTAL WATERS THIS EVENING. AS THE
OFFSHORE LOW BECOMES A LITTLE BETTER DEFINED OVERNIGHT ISOLATED
SHOWERS AND THUNDERSTORMS MAY DEVELOP ALMOST ANYTIME. NO SIGNIFICANT
CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION FROM 800 PM
FOLLOWS...
A COLD FRONT EXTENDING FROM THE HAMPTON ROADS VICINITY ACROSS
RALEIGH...ASHEBORO TO CHARLOTTE WILL MOVE SOUTH OVERNIGHT...REACHING
THE COASTAL WATERS SHORTLY AFTER DAYBREAK THURSDAY. THE FRONT IS
CURRENTLY MOVING VERY SLOWLY BUT WILL GET A BOOST IN SPEED LATE
TONIGHT AS SURFACE LOW PRESSURE...JUST NOW DEVELOPING ABOUT 75 MILES
SOUTHEAST OF MYRTLE BEACH...BECOMES BETTER DEFINED BY MORNING. THIS
LOW MAY BE A HEADACHE FOR FOLKS ALONG THE MID-ATLANTIC AND NORTHEAST
COAST OVER THE NEXT FEW DAYS...BUT FOR US WILL ONLY AID IN PULLING
THE COLD FRONT OFFSHORE A LITTLE MORE QUICKLY THAN IT WOULD HAVE
OTHERWISE. SCATTERED SHOWERS AND T-STORMS SHOULD DEVELOP OVERNIGHT
WITH PERHAPS 30 PERCENT COVERAGE BEFORE DAYBREAK.
SURFACE WINDS CURRENTLY FROM THE SOUTH WILL BECOME LIGHT AND
VARIABLE OVERNIGHT IN THE WEAK GRADIENT BETWEEN THE COLD FRONT TO
THE NORTH AND THE LOW DEVELOPING TO THE EAST. WIND DIRECTIONS WILL
FINALLY BECOME NORTHEAST THURSDAY AFTER DAYBREAK AS THE FRONT
ARRIVES. SEAS ARE CURRENTLY 2-3 FT...WITH PERHAPS A 20% DECREASE IN
HEIGHT EXPECTED OVERNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...WEAK GRADIENT WITH NORTH-NORTHEASTERLY FLOW
WILL CONTINUE THROUGH EARLY FRIDAY AS A FAIRLY WEAK FRONT PUSHES
OFFSHORE. COULD SEE A POSSIBLE INCREASE OF WINDS UP TO 10
KTS...POSSIBLY 15 KTS...FRIDAY AFTERNOON. OTHERWISE WILL REMAIN
LIGHT. EXPECT WAVE HEIGHTS OF 2 TO 3 FEET.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 PM WEDNESDAY...WEAK RESIDUAL TROUGH/WARM FRONT WILL LIFT
NORTH OVER THE WATERS AT THE START OF THE PERIOD...LEAVING LIGHT SE
WINDS SATURDAY...VEERING TO SOUTH THEN SOUTHWEST THROUGH THE
REMAINDER OF THE PERIOD. AS THESE WINDS VEER...THE GRADIENT REMAINS
QUITE DIFFUSE...SO SPEEDS WILL ONLY BE AROUND 10 KTS REGARDLESS OF
DIRECTION. ALTHOUGH A VERY WEAK 1FT/8SEC SE GROUND SWELL WILL BE
PRESENT WITHIN THE WAVE SPECTRUM EACH DAY...SEAS WILL BE PRIMARILY
CONTROLLED BY A SOUTHERLY WIND CHOP OF 3-4 FT/6 SEC. THIS CREATES
SIGNIFICANT SEAS OF 2-3 FT EACH DAY...WITH A FEW 4 FTERS POSSIBLE
NEAR THE 20 NM BOUNDARY AT THE END OF THE PERIOD.
&&
.TIDES/COASTAL FLOODING...
AS OF 1 PM WEDNESDAY...THE CAPE FEAR RIVER CRESTED AT 6.06 FT MLLW
IN DOWNTOWN WILMINGTON LAST NIGHT. THIS IS THE RESULT OF THE
ASTRONOMICAL HIGH TIDE ASSOCIATED WITH THE WANING FULL MOON...PLUS A
LARGE AMOUNT OF WATER DRAINING DOWN THE CAPE FEAR RIVER SYSTEM FROM
EXCESSIVE RAINS OVER THE PAST FEW WEEKS. WE AGAIN EXPECT WATER
LEVELS TO EXCEED FLOOD STAGE TONIGHT...THE HIGHEST LEVELS WILL OCCUR
BETWEEN 11 PM AND 1 AM...REACHING AROUND 5.75 FT. TIDAL DEPARTURES
WILL CONTINUE TO SLOWLY DECREASE THROUGH LATE WEEK AS WE MOVE
FURTHER AWAY FROM THE FULL MOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...SGL
LONG TERM...JDW
AVIATION...43
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
116 AM EDT TUE JUL 23 2013
.SYNOPSIS...
SEASONABLE AND WARM TEMPERATURES WILL CONTINUE WITH ISOLATED TO
SCATTERED AFTERNOON SHOWERS AS BERMUDA HIGH PRESSURE REACHES INTO
THE AREA FROM THE EAST . A FRONT WILL APPROACH FROM THE NORTHWEST
WEDNESDAY NIGHT AND STALL ACROSS THE AREA ON THURSDAY...PRODUCING
MORE UNSETTLED WEATHER THROUGH LATE WEEK. ANOTHER COLD FRONT WILL
MOVE INTO THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:15 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
BERMUDA HIGH PRESSURE OVER A THOUSAND MILES OFF THE COAST IS
PRODUCING A SOUTHWEST FLOW ACROSS THE EASTERN CAROLINAS. LOW
PRESSURE MOVING EAST THROUGH THE CENTRAL APPALACHIANS AND A
PIEDMONT TROUGH STATIONARY ACROSS THE CENTRAL CAROLINAS INTO
EASTERN VIRGINIA ARE BOTH HELPING TO PINCH THE PRESSURE GRADIENT
TIGHTER. SINCE SUNSET...INLAND TEMPERATURES HAVE COOLED
SUFFICIENTLY TO SHIFT MOST OF THE WIND`S MOMENTUM UP INTO A LOW
LEVEL JET WITH 1000 FT AGL WIND SPEED NEAR 30 KNOTS. OVER THE WARM
OCEAN AND ALONG PRIMARILY SOUTH-FACING BEACHES THESE STRONGER
WINDS ARE MIXING DOWN TO THE SURFACE WITH WIND GUSTS OVER 30 MPH
RECENTLY REPORTED FROM OAK ISLAND AND BALD HEAD ISLAND.
AS A LANDBREEZE HELPS ADVECT SOME OF THE COOLER AIR INLAND DOWN TO
THE COAST OVERNIGHT LOW-LEVEL LAPSE RATES SHOULD LESSEN ENOUGH TO
PREVENT THESE STRONGER WINDS FROM COMING DOWN TO THE SURFACE. UNTIL
THEN...HANG ONTO YOUR HAT ALONG THE BRUNSWICK COUNTY BEACHES.
A POCKET OF DRY AIR IN THE 800-500 MB LAYER WILL EXIT THE COAST
SHORTLY...WITH PRECIPITABLE WATER VALUES RISING FROM 1.7 INCHES TO
NEARLY 2 INCHES LATE TONIGHT. AN UPPER LEVEL DISTURBANCE PRODUCING
T-STORMS ACROSS THE MOUNTAINS AND FOOTHILLS WILL APPROACH THE
EASTERN CAROLINAS AROUND DAYBREAK. THIS IS TYPICALLY THE MOST
UNFAVORABLE TIME OF DAY FOR CONVECTION WITH INSTABILITY THE WEAKEST.
FORECAST SOUNDINGS SHOW TOO MUCH CAPPING TO OVERCOME GIVEN THE
MODEST LIFT AHEAD OF THE UPPER DISTURBANCE SO I HAVE MAINTAINED A
DRY FORECAST OVERNIGHT FOR MOST AREAS. AT THE BEACHES AND ESPECIALLY
OFFSHORE...ISOLATED TO SCATTERED SHOWERS MAY DEVELOP LATE WITHIN
WARMER...MORE UNSTABLE CONDITIONS.
NO SIGNIFICANT CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS
WHICH RANGE FROM 73-77...WARMEST AT THE BEACHES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...A SHORTWAVE WILL RIDE THROUGH A VERY BROAD
TROUGH LOCATED OVER THE EASTERN CONUS. THIS WILL HELP TO PRODUCE
SOME CLOUDS AND A FEW SHOWERS EARLY MORNING ON TUES BUT THE
SHORTWAVE WILL SHIFT OFF THE COAST BY AFTERNOON WITH A DEEPER W-NW
FLOW OF DRIER AIR AND SUBSIDENCE DEVELOPING THROUGH TUES AFTN INTO
WED. THE WESTERLY DOWNSLOPE COMPONENT TO THE FLOW WILL ALSO AID IN
DRYING AND WARMING...ESPECIALLY INLAND THROUGH TUES AFTN. TEMPS
SHOULD REACH 90 OR SLIGHTLY ABOVE MOST PLACES TUES AND DROP TO
THE MID 70S OVERNIGHT.
THE DRIER AIR AND SUBSIDENCE THROUGH THE MID LEVELS WILL HOLD
THROUGH MUCH OF WEDNESDAY AS FRONT BEGINS TO ENTER INTO CAROLINAS
FROM THE NORTH AND WEST BY LATE DAY. BY WED NIGHT THE MID TO UPPER
TROUGH BECOMES MORE AMPLIFIED AS IT PUSHES A FRONT/TROUGH SOUTH
AND EAST INTO AREA. THIS WILL INCREASE CHANCES OF SHWRS/TSTMS
OVERNIGHT BUT MORE SO ON THURS. THE WESTERLY DOWNSLOPE WINDS IN
THE LOW LEVELS AND A GOOD DEAL OF SUNSHINE WILL AID IN PUSHING
TEMPS INTO THE 90S ON WED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH THE
AMPLIFIED FLOW ALOFT WILL KEEP WEATHER ACTIVE DURING THE PERIOD.
BOTH SHORTWAVES WILL BE ACCOMPANIED BY A COLD FRONT THAT WILL TRY TO
PUSH ACROSS THE AREA. THE FIRST WILL BE MOVING INTO THE AREA AS THE
PERIOD BEGINS WITH A SECOND STRONGER FRONT ARRIVING MON. THE LARGE
SCALE 5H TROUGH AXIS REMAINS WEST OF THE AREA THROUGH AT LEAST THE
WEEKEND. THE FIRST FRONT ENDS UP LAYING PARALLEL TO THE STEERING
FLOW AND STALLS ACROSS OR JUST EAST OF THE AREA. SURFACE BOUNDARY IN
AIR MASS WITH DEEP MOISTURE AND DIURNAL INSTABILITY SHOULD PROVIDE A
FOCAL POINT FOR CONVECTION. SOME UNCERTAINTY WITH RESPECT TO THE
LOCATION OF THE FRONT AND AMOUNT OF DRY AIR ALOFT SPREADING OVER THE
AREA FRI/SAT SO WILL CARRY LOWER POP DURING THESE PERIODS THOUGH
STILL IN THE CHANCE CATEGORY DURING THE DAY.
PRECIP CHANCES INCREASE SUN/MON AS NEXT COLD FRONT APPROACHES FROM
THE WEST AND DEEP MOISTURE RETURNS. DIVERGENCE ALOFT WILL ENHANCE
BOTH LIFT ALONG THE FRONT AND DIURNAL INSTABILITY. TIMING...LOCATION
AND STRENGTH DIFFERENCE BETWEEN GFS/ECMWF DO ADD A LITTLE BIT OF
UNCERTAINTY EARLY NEXT WEEK SO FOR NOW WILL MAINTAIN CHANCE POP BUT
SHOW AN INCREASE OVER FRI/SAT.
HIGHS WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD WITH
LOWS NEAR TO SLIGHTLY ABOVE CLIMO.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...SYNOPTICALLY NOT MUCH HAS CHANGED IN THE PAST 24 HOURS.
AIR A BIT DRIER ALOFT...BUT SOME DEEPER MOISTURE MAY WORK ITS WAY IN
AFTER MIDNIGHT WITH A SLIGHT CHANCE OF SHOWERS. ANY CONVECTION
TOWARD MORNING WILL LIKELY SET UP JUST OFFSHORE.
BASED MAINLY ON CONTINUITY...WILL INTRODUCE NEAR IFR STRATUS AT THE
INLAND TERMINALS...WITH A MVFR CEILING FORMING NEAR SUNRISE. WINDS
AT THE BOUNDARY LAYER ARE TOO STRONG TO SUPPORT FOG...MVFR BEFORE
SUNRISE WORST CASE. TUESDAY...DAYTIME HEATING WILL KICK OFF
SCATTERED CONVECTION BY 17Z...FOCUSED FIRST ON THE SEA BREEZE
BOUNDARY WITH SCATTERED ACTIVITY INLAND AFTER 19Z. CONVECTION WILL
WIND DOWN SEVERAL HOURS AFTER MAX HEATING.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED THROUGH THURSDAY...WITH BRIEF LOCALIZED PERIODS OF
MVFR/IFR POSSIBLE. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...AS OF 1:15 AM TUESDAY...NO CHANGES TO
THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
RECENT WIND GUSTS HAVE REACHED 31 KNOTS AT THE OCEAN CREST PIER ON
OAK ISLAND...28 KNOTS ON BALD HEAD ISLAND...AND 27 KNOTS AT THE
FRYING PAN SHOALS BUOY. THIS APPEARS TO BE FROM A LOW-LEVEL JET
DEVELOPING INLAND WHERE SURFACE TEMPERATURES ARE COOLER. AS THIS
JET BLOWS EAST TO THE COAST AND ENCOUNTERS A WARMER MORE WELL-
MIXED ENVIRONMENT THE MOMENTUM IS DISTRIBUTED DOWNWARD IN STRONG
GUSTS AS WE ARE SEEING. THIS ADDITIONAL INPUT OF WIND ENERGY INTO
THE OCEAN HAS PUSHED SEA HEIGHTS UP TO 5.5 FEET AT THE WILMINGTON
HARBOR BUOY JUST SOUTH OF SOUTHPORT...AND TO 6 FEET AT THE FRYING
PAN SHOALS BUOY. FOR THIS REASON I HAVE ISSUED A SMALL CRAFT
ADVISORY FOR THE NC WATERS THROUGH 3 AM...AND RETAINED THE
EXERCISE CAUTION HEADLINE FOR THE SC WATERS AS WELL.
THE LATEST SEVERAL RUNS OF THE HRRR AND THE 18Z NAM SHOW THIS
LOW-LEVEL JET FAIRLY WELL...WITH 975 MB (1000 FT AGL) WIND SPEEDS
HOLDING AROUND 30 KNOTS THROUGH 06Z (2 AM EDT) BEFORE VEERING
DIRECTIONS MORE WESTERLY WITH DECREASING SPEEDS LATE.
OUR SYNOPTIC WEATHER PATTERN FEATURES BERMUDA HIGH PRESSURE OVER A
THOUSAND MILES OFF THE CAROLINA COAST. LOW PRESSURE IS MOVING EAST
THROUGH THE CENTRAL APPALACHIANS...AND A PIEDMONT TROUGH IS
STATIONARY ACROSS THE CENTRAL CAROLINAS INTO EASTERN VIRGINIA. THE
PRESSURE GRADIENT SOUTH OF THE CENTRAL APPALACHIAN LOW IS PRODUCING
THE BREEZY SOUTHWEST WINDS...WHICH SHOULD VEER MORE WESTERLY
OVERNIGHT WITH A DEVELOPING LANDBREEZE. ALTHOUGH THE RADAR IS
CURRENTLY CLEAR...THE APPROACH OF AN UPPER LEVEL DISTURBANCE AFTER
MIDNIGHT COULD HELP IGNITE ISOLATED SHOWERS OR T-STORMS OVER THE
WATERS...BUT MAINLY FARTHER EAST AWAY FROM SHORE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...SOUTHWEST WINDS WILL CONTINUE BETWEEN BERMUDA
HIGH TO THE EAST AND TROUGH ACROSS INLAND CAROLINAS. THE WINDS
WILL PICK UP SLIGHTLY TUES AFTN AS PINCHED GRADIENT DEVELOPS AS
TROUGH BECOMES MORE PRONOUNCED INLAND AND PUSHES EAST SLIGHTLY
IN COMBINATION WITH AFTN SEA BREEZE. BY WED NIGHT INTO EARLY
THURS A FRONT WILL MOVE DOWN FROM THE NORTH AND WEST WITH WINDS
SHIFTING TO THE N-NE TO THE NORTH OF THE BOUNDARY AND REMAINING SW
TO THE SOUTH OF THE BOUNDARY. OVERALL EXPECT SOUTHWEST WINDS OF
10-15 KNOTS THROUGH MUCH OF THE PERIOD. SEAS WILL RANGE FROM 2-4
FT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...SOUTHERLY FLOW THU WILL BECOME LIGHT AND
VARIABLE FRI AND SAT AS WEAK SURFACE BOUNDARY MOVES ACROSS THE
WATERS. MAY SEE SOME PERIODS OF LIGHT NORTHERLY FLOW BUT PROXIMITY
TO THE BOUNDARY WILL KEEP SPEEDS UNDER 10 KT. LATE IN THE PERIOD
REMNANTS OF BOUNDARY LIFT NORTH WITH LIGHT SOUTHERLY FLOW
DEVELOPING. WEAK GRADIENT THROUGH THE PERIOD KEEPING WINDS UNDER 10
KT WILL KEEP SEAS AROUND 2 FT FOR MUCH OF THE PERIOD...THOUGH SOME
ISOLATED 3 FT IS POSSIBLE AWAY FROM SHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
AMZ250-252.
&&
$$
NEAR TERM...REK/TRA
AVIATION...DL
MARINE...REK/TRA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
309 PM CDT TUE JUL 23 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 309 PM CDT TUE JUL 23 2013
MAIN FORECAST CHALLENGE REMAINS PCPN CHANCES OVER THE NEXT FEW
DAYS. MODELS SEEM TO BE IN BETTER AGREEMENT ON THE DETAILS THIS
TIME AROUND WHICH MATCH UP PRETTY WELL WITH FORECAST CONTINUITY.
THEREFORE DO NOT PLAN MANY CHANGES TO THE SHORT TERM.
QUITE A BIT OF CUMULUS FORMED ACROSS THE AREA AGAIN TODAY WHICH
LIKELY HELPED TO HOLD DOWN TEMPS A LITTLE. EXPECT THE CUMULUS TO
THIN OUT THIS EVENING. THE MID AND HIGH LEVEL CLOUDS ASSOCIATED
WITH AREA OF PCPN OVER NORTHWEST ND SHOULD DRIFT INTO PORTIONS OF
THE FA. ANY ACTUAL PCPN SHOULD TRACK FROM NORTHWEST ND DOWN INTO
NORTHEAST SD TONIGHT. LATEST VERSION OF THE RAP SEEMS TO SHOW THIS
WELL. WILL LEAVE INHERITED PCPN CHANCES ACROSS THE SOUTHWEST FOR
LATE TONIGHT BASICALLY AS IS. PRETTY DRY SFC DEW POINT READINGS
ESPECIALLY IN THE EAST SO CUT BACK A LITTLE ON MIN TEMPS THERE.
FOR WED THERE ARE NOT A LOT OF CHANGES FROM TODAY. STILL IN NW
FLOW WITH WEAK EMBEDDED IMPULSES. MODELS ALL SEEM CONSISTENT IN
SHOWING SOME LIGHT PCPN ACROSS THE AREA. THESE CHANCES SHOULD
SHIFT INTO NORTHWEST MN WED NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE JUL 23 2013
BY THU THE NEXT SFC COLD FRONT WILL SWING THRU THE FA WITH A
LITTLE STRONGER UPPER LEVEL DISTURBANCE. THIS WILL PROBABLY BE THE
TIME PERIOD WITH THE BEST CHANCE FOR PCPN ALTHOUGH AMOUNTS WILL BE
PRETTY LIGHT. WILL LEAVE THU NIGHT DRY. STILL HAVE SOME QUESTIONS
ABOUT PCPN CHANCES AGAIN BY FRI. MODELS ARE INDICATING A
SUBSTANTIAL PIECE OF SHORTWAVE ENERGY DROPPING THROUGH WITH CHILLY
500MB TEMPS. LEFT SOME LOW CHANCES FOR PCPN IN THE EAST.
FOR FRI NIGHT THROUGH TUE...THE PERIOD WILL BEGIN WITH TEMPS
BELOW NORMAL AND DRY WEATHER...WITH COOL CANADIAN HIGH PRESSURE IN
CONTROL. TEMPS AND MOISTURE PROFILES WILL INCREASE BY EARLY NEXT
WEEK...WITH A CHANCE FOR SHOWERS AND STORMS WITH MORE ZONAL FLOW
ALOFT. MOST AREAS COULD REMAIN DRY THROUGH MONDAY...WITH DRY AIR
IN PLACE INITIALLY AND IT WILL TAKE TIME TO MOISTEN COLUMN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1226 PM CDT TUE JUL 23 2013
EXPECT VFR CONDITIONS WITH SOME MID/HIGH LEVEL CLOUDS TODAY. WINDS
WILL BE LIGHT...UNDER 10 KT THROUGH THE PERIOD AS WELL. A CONVECTIVE
CLUSTER COULD SPREAD SOME SHOWERS OR PERHAPS A RUMBLE OF THUNDER
INTO THE AREA WED MORNING...MAINLY IN THE SOUTH. FOR NOW CONFIDENCE
NOT HIGH ENOUGH TO MENTION BUT SOMETHING TO MONITOR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...DK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1216 PM CDT TUE JUL 23 2013
.UPDATE...
ISSUED AT 1202 PM CDT TUE JUL 23 2013
DIURNAL LOW LEVEL JET CONTINUES TO MIX OUT WITH UPSTREAM MCS IN
NORTHEAST MONTANA GOING THROUGH ITS DIURNAL MINIMA AT THIS TIME.
QUESTION IS WHEN WILL THE THUNDERSTORMS INCREASE/REGENERATE.
CURRENT THINKING CONTINUES TO BE AROUND 21-23Z WITH SLIGHT RISK
SEVERE WEST CENTRAL AND SOUTHWEST LATE AFTERNOON AND EVENING.
INCREASED CLOUDINESS NORTH AND SOUTH CENTRAL WHERE WARM ADVECTION
UPLIFT/AFTERNOON HEATING EAST OF SURFACE TROUGH IN MONTANA SEEMS
TO BE SUSTAINING THE CLOUD AREA. ALSO LOWERED HIGHS IN THE CLOUDY
REGION 2 TO 3 DEGREES FOR THIS AFTERNOON.
UPDATE ISSUED AT 1017 AM CDT TUE JUL 23 2013
THIS UPDATE FOR A BAND OF CLOUDINESS ACROSS THE CENTRAL SECTIONS.
ADDED MORE CLOUDS TO THE MORNING AND EARLY AFTERNOON THAT ARE
ASSOCIATED WITH BROAD WARM ADVECTION UPLIFT.
UPDATE ISSUED AT 842 AM CDT TUE JUL 23 2013
EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.
UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013
ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013
THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.
WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013
MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.
COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1202 PM CDT TUE JUL 23 2013
AT NOON CDT...A TROUGH OF LOW PRESSURE ACROSS EASTERN MONTANA WAS
ASSOCIATED WITH A WEAK SHORTWAVE TROUGH MOVING IN NORTHWEST FLOW
ALOFT. A DYING CLUSTER OF THUNDERSTORMS IN NORTHWEST MONTANA WILL
SLOWLY REGENERATE AS THUNDERSTORMS IN WESTERN NORTH DAKOTA LATE
TUESDAY AFTERNOON. VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES
THROUGH THE 18Z TAF PERIOD. THE MAIN HAZARD TO AVIATION WILL BE
THE RISK OF THUNDERSTORMS AFTER 20Z AT KISN-KDIK. AT THIS TIME...
THREAT OF THUNDERSTORMS AT THE TAF SITES ARE STILL LOW SO WILL
CONTINUE TO EXPRESS THIS THREAT AS VCTS (VICINITY) AT KISN-KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1020 AM CDT TUE JUL 23 2013
.UPDATE...
ISSUED AT 1017 AM CDT TUE JUL 23 2013
THIS UPDATE FOR A BAND OF CLOUDINESS ACROSS TEH CENTRAL SECTIONS.
ADDED MORE CLOUDS TO THE MORNING AND EARLY AFTERNOON THAT ARE
ASSOCIATED WITH BROAD WARM ADVECTION UPLIFT.
UPDATE ISSUED AT 842 AM CDT TUE JUL 23 2013
EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.
UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013
ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013
THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.
WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013
MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.
COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY AFTERNOON)
ISSUED AT 1017 AM CDT TUE JUL 23 2013
VFR CONDITIONS ARE EXPECTED FOR THE 12 UTC TAF CYCLE OUTSIDE OF
THUNDERSTORMS EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA LATE THIS
AFTERNOON AFTER 21-22 UTC. THESE STORMS MAY PUSH INTO SOUTH
CENTRAL NORTH DAKOTA LATE THIS EVENING. GIVEN UNCERTAINTY IN EXACT
TIMING AND IMPACTS TO THE TERMINALS...CODED AS VCTS FOR NOW FOR
KBIS...KDIK AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
850 AM CDT TUE JUL 23 2013
.UPDATE...
ISSUED AT 842 AM CDT TUE JUL 23 2013
EARLY MORNING CONVECTION ALONG THE DIURNALLY DRIVEN LOW LEVEL JET
AXIS AS DEPICTED BY THE RUC MODEL NOW DISSIPATING. WITH THIS TREND
IN MIND HAVE ELIMINATED THE THE MORNING CHANCE FOR THUNDERSTORMS.
NEXT CHANCE FOR PRECIPITATION WILL BE WITH THE AFTERNOON AND
EVENING SHORTWAVE EXPECTED TO BRING THUNDERSTORMS TO THE WEST.
WITH SPC ADDING SLIGHT RISK SEVERE TO THE SOUTHWEST HAVE ADDED
MENTION OF SEVERE STORMS LATE THIS AFTERNOON AND EVENING.
UPDATE ISSUED AT 642 AM CDT TUE JUL 23 2013
ONLY A FEW MINOR ISSUES WITH THE EARLY MORNING UPDATE. RAISED
CLOUD COVER OVER THE AREA FOR A FEW HOURS THIS MORNING WITH
SATELLITE INDICATING QUITE A BIT OF JET INDUCED MID LEVEL
CLOUDINESS OVER THE AREA THIS MORNING. ISOLATED SHOWERS IN THE FAR
EASTERN CWA SHOULD MOVE OUT OF THE AREA SHORTLY SO WILL NOT ADD
ANY MENTION OF SHOWERS HERE FOR THE REMAINDER OF THE MORNING. A
COUPLE REPORTING STATIONS INDICATING FOG ACROSS THE NORTH THIS
MORNING ON THE BACK SIDE OF A WEAK SURFACE HIGH OVER FAR SOUTHWEST
MANITOBA...SO ADDED A COUPLE HOURS OF PATCHY FOG OVER PORTIONS OF
THE FAR NORTH.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM CDT TUE JUL 23 2013
THE HIGHLIGHT OF THE SHORT TERM IS THE CONVECTIVE POTENTIAL THIS
AFTERNOON THROUGH TONIGHT.
WHILE THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITE IS IN GOOD
AGREEMENT ON THE DEVELOPMENT OF AN INSTABILITY AXIS ACROSS EASTERN
MONTANA AND WESTERN NORTH DAKOTA ON THE WESTERN PERIPHERY OF
SURFACE HIGH PRESSURE...DIFFERENCES DO EXIST IN REGARDS TO HOW THE
CONVECTIVE SCENARIO WILL UNFOLD. IN GENERAL...ML CAPE OF 1000-1500
J/KG IS FORECAST TO DEVELOP ACROSS THE AFOREMENTIONED AREAS THIS
AFTERNOON...WITH DEEP LAYER SHEAR OF 30-40 KTS. THE CONVECTIVE
SCENARIOS OFFERED BY THE DETERMINISTIC MODELS RANGE FROM VERY
LITTLE CONVECTION ON THE ECMWF...TO A LINE OF STRONG TO SEVERE
THUNDERSTORMS ON THE 00 UTC 4 KM WRF ENTERING WESTERN NORTH DAKOTA
BETWEEN 20-22 UTC WITH THE ARRIVAL OF WEAK IMPULSES
ALOFT. THIS FORECAST CONVECTION THEN PROPAGATES INTO SOUTH CENTRAL
NORTH DAKOTA THROUGH THE EVENING...WHICH IS AT LEAST SUGGESTED ON
MOST OF THE DETERMINISTIC MODELS BY 06 UTC. YET HOW FAR PAST 06
UTC CONVECTION CAN REMAIN ORGANIZED WITH THE LACK OF A LOW LEVEL
JET IS UNCERTAIN. SPC DOES HAVE MUCH OF THE CWA IN A SEE TEXT WITH
5 PERCENT HAIL AND WIND CONTOURS. GIVEN UNCERTAINTY...LEFT THE
MENTION OF SEVERE OUT OF THE GRIDS FOR NOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 402 AM CDT TUE JUL 23 2013
MAIN FORECAST PROBLEM EARLY IN THE EXTENDED PERIOD WILL BE
PRECIPITATION CHANCES IN A PROGRESSIVE NORTHWEST FLOW. WEAK SURFACE
HIGH PRESSURE IS OVER THE AREA ON WEDNESDAY BUT DAYTIME HEATING AND
UPPER LEVEL JET OVER THE AREA WILL PROVIDE A CHANCE OF SHOWERS AND
THUNDERSTORMS. 00Z 23 JUN GFS FCST BUFR SOUNDINGS INDICATE
ATMOSPHERE BECOMES UNSTABLE ACROSS THE AREA WITH A STRONG NORTHWEST
FLOW ALOFT. WEDNESDAY NIGHT INTO THURSDAY A STRONGER UPPER LEVEL JET
DROPS SOUTH FROM CANADA AS A DEEP UPPER LEVEL LOW DROPS OVER THE
GREAT LAKES. KEEPING A CHANCE OF CONVECTION IN THE FORECAST UNTIL
DRIER AIR WORKS FROM NORTH TO SOUTH ACROSS THE AREA DURING THE
MORNING HOURS ON THURSDAY.
COOL SURFACE HIGH PRESSURE WILL PERSIST OVER THE AREA FRIDAY WITH
HIGHS MAINLY IN THE 70S. UPPER LEVEL RIDGING BUILDS OVER THE AREA
BEHIND THE EXITING GREAT LAKES CYCLONE OVER THE WEEKEND. BUT
SHORTWAVE ENERGY ROTATING AROUND ANOTHER UPPER LOW OVER WESTERN
CANADA WORKS TO BREAK DOWN THE RIDGE. THERE ARE DIFFERENCES BETWEEN
THE GFS/ECMWF IN HOW MUCH SHORTWAVE ENERGY CAN MAKE IT OVER THE
RIDGE...THUS SETTLED ON A MODEL BLEND WHICH KEEPS SATURDAY DRY AND
BRING SLIGHT CHANCE POPS INTO THE FAR WEST SATURDAY NIGHT...AND
PROGRESSING INTO THE CENTRAL ON SUNDAY. FLOW THEN BECOMES SOUTHWEST
BY EARLY NEXT WEEK...KEEPING A RISK OF THUNDERSTORMS IN THE FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 842 AM CDT TUE JUL 23 2013
VFR CONDITIONS ARE EXPECTED FOR THE 12 UTC TAF CYCLE OUTSIDE OF
THUNDERSTORMS EXPECTED TO MOVE INTO WESTERN NORTH DAKOTA LATE THIS
AFTERNOON AFTER 21-22 UTC. THESE STORMS MAY PUSH INTO SOUTH
CENTRAL NORTH DAKOTA LATE THIS EVENING. GIVEN UNCERTAINTY IN EXACT
TIMING AND IMPACTS TO THE TERMINALS...CODED AS VCTS FOR NOW FOR
KBIS...KDIK AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
350 AM EDT TUE JUL 23 2013
.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
130 AM UPDATE...
NO SIGNIFICANT CHANGES TO ONGOING FORECAST. BACK EDGE OF PRECIP
APPROACHING THE OHIO RIVER AT THIS TIME.
PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.
UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.
THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.
ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... MODELS
INDICATED ANOTHER BROAD LOW PRESSURE SYSTEM OVER CANADA SPITTING
ENERGY IN FORM OF VORTICITY MAXES SOUTH ACROSS SOUTHEAST OH AND WV
WEDNESDAY. A COLD FRONT WILL EXIT THE EASTERN MOUNTAINS ON
WEDNESDAY. THEREFORE...KEPT THE PREVIOUS TREND OF DECREASING POPS
WITH CHANCES ACROSS THE WESTERN SLOPES AND HIGHER ELEVATIONS...TO
SLIGHT CHANCES ACROSS THE LOWLANDS...DIMINISHING TOWARDS WEDNESDAY
EVENING.
A HIGH PRESSURE BUILDS IN WEDNESDAY...TO PROVIDE DRY CONDITIONS
THROUGH THURSDAY NIGHT. THE EXCEPTION WILL BE AFTERNOON CLOUDS AND
ISOLATED SHOWERS. AREAS OF FOG CAN BE ANTICIPATED EARLY THURSDAY
MORNING OVER AREAS THAT RECEIVE RAIN FROM THE PASSING COLD FRONT.
BEHIND THE FRONT...RELATIVELY COOLER AIR FILTERS IN TO KEEP
COMFORTABLE TEMPERATURES WEDNESDAY...REACHING 80F ACROSS THE
LOWLANDS...RANGING TO THE LOWER 70S HIGHER TERRAIN. IT WILL FEW
DEGREES WARMER THURSDAY PER WEAK WARM ADVECTION FROM THE
SOUTHWEST...AND PLENTY OF SUNSHINE.
FOR MIN TEMPERATURES WENT COOLER ON WEDNESDAY NIGHT AS H850
TEMPERATURES DROP TO 9C...AND WITH CLEAR SKIES...EXPECT
RADIATIONAL COOLING FOR A COMFORTABLE NIGHT.
USED A BLEND OF BIAS CORRECTED SREF AND BIAS CORRECTED GMOS
THROUGH THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...
SCATTERED SHOWERS CONTINUE PRIMARILY ACROSS THE EASTERN PART OF
THE AREA...WITH THE BACK EDGE OF THE PRECIPITATION CURRENTLY
APPROACHING THE OHIO RIVER. SHOULD A HEAVIER SHOWER DIRECTLY
IMPACT A TERMINAL...BRIEF MVFR VIS MAY RESULT. OTHERWISE EXPECT
SHOWERS TO END FROM WEST TO EAST OVERNIGHT. IFR AND SUB-IFR
CONDITIONS IN FOG AND LOW STRATUS STILL EXPECTED FOR MOST
LOCATIONS BY THE 09Z-12Z TIME FRAME. THIS WILL SCATTER/RISE BY THE
MID-MORNING HOURS WITH VFR CONDITIONS PREVAILING THROUGH THE
REMAINDER OF THE DAY. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO FORM ONCE AGAIN LATE AFTERNOON AND EVENING WHICH MAY
RESULT IN INTERMITTENT MVFR/IFR VIS...WITH MORE GENERAL COVERAGE
OF PRECIP ARRIVING NEAR THE END OF THE VALID PERIOD WITH THE
APPROACH OF A COLD FRONT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT AND EARLY THIS MORNING...AS WELL AS TIMING OF
IMPROVEMENT THIS MORNING.
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.
DATE TUE 07/23/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H M H H M M M
HTS CONSISTENCY L L L L L L H H M H H H
BKW CONSISTENCY H H L L M H H H H H H H
EKN CONSISTENCY M L L M L M M H M H H H
PKB CONSISTENCY M H M H L L H H M M M M
CKB CONSISTENCY H M M M M H H H M M M M
AFTER 06Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/30
NEAR TERM...50/30
SHORT TERM...ARJ
LONG TERM...KMC
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
148 AM EDT TUE JUL 23 2013
.SYNOPSIS...
MID/UPPER DISTURBANCES MOVING UP THE OHIO VALLEY INTO WEDNESDAY WITH
ROUNDS OF CONVECTION. FLASH FLOOD HAZARD LINGERS.
&&
.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...
NO SIGNIFICANT CHANGES TO ONGOING FORECAST. BACK EDGE OF PRECIP
APPROACHING THE OHIO RIVER AT THIS TIME.
PREVIOUS DISCUSSION FOLLOWS...
WILL BE TRACKING A POTENT UPR LVL SYS...LOCATED ACROSS W OH AND
KY...WITH A MESO VORTEX APPENDAGE MOVING NE INTO NE KY. USED LATEST
RUC AND HRRR FOR TIMING AND PLACEMENT OF POPS WITH THIS SYS WITH HVY
SHRA CURRENTLY MOVING BACK INTO NE KY AND SE OH AND INTO S WV/SW VA
BY 21Z. HAVE SCT SHRA IN GRIDS IN MEANTIME. LOW CLDS SCT OUT ACROSS
WV/SW VA RVR WHICH WILL HELP TO DESTABILIZE ATMOS FOR THIS SYS TO
WORK ON THIS AFTN. ROLLED WITH CATEGORICAL POPS MOST PLACES LATE
AFTN INTO EARLY THIS EVE AND INSERTED HVY RA WORDING IN COVERAGE
TERMS AS PWATS ON EITHER SIDE OF 2 INCHES. FLASH FLOOD WATCH CONT
THRU TONIGHT.
UPR TROF CROSSES TONIGHT WITH PERHAPS ADDITIONAL SHRA/TSRA MOVING
IN THIS EVE AFFECTING SE OH/NE KY/N WV. TROF AXIS SHOULD BE E OF
AREA AFTER 09Z WITH PCPN THREAT DIMINISHING.
THINK SOME LOW STRATUS AND FG DEVELOPS OVERNIGHT WHICH MAY TAKE
UNTIL MID MORNING TO SCT OUT. HAVE ISO TO SCT SHRA/TSRA BY
AFTN...WITH AN UPTICK LATE WITH A FAST MOVING SYS DROPPING IN NW
FLOW ALOFT.
ROLLED WITH WARMER GUIDANCE TONIGHT AND TOMORROW...THINKING AREA
SHOULD GET A DECENT SHOT OF SUN TOMORROW BEFORE SHRA/TSRA GET GOING.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
COLD FRONT SWINGS THROUGH TUESDAY NIGHT AS 5H TROF SWINGS THROUGH
AT THE MID LEVELS. CARRIED LIKELY POPS AS THERE WILL BE DECENT
DYNAMIC FORCING COUPLED WITH PLENTY OF A AVAILABLE MOISTURE.
HOWEVER...CHANCES FOR SEVERE WEATHER ASSOCIATED WITH THIS FEATURE
WILL BE LIMITED DUE TO THE LACK OF DAYTIME HEATING DURING THE
OVERNIGHT HOURS.
AS HIGH PRESSURE BUILDS IN WEDNESDAY...BULK OF MOISTURE WILL BE
SHUNTED TO THE EAST...LEADING TO A DRYING TREND. SHOULD SEE A
NOTICEABLE DECREASE IN CONVECTIVE ACTIVITY WEDNESDAY AND THURSDAY
AS LOW AND MID LEVEL COOL POOL HELPS TO STABILIZE THE ATMOSPHERE.
LEFT CHANCE POPS IN FOR MOUNTAINS AS HEATING IN ELEVATED TERRAIN
COULD STILL LEAD TO SOME CONVECTIVE DEVELOPMENT.
WILL SEE A COOLING TREND THIS PERIOD. GOING WITH MODEL BLEND FOR
TEMPERATURES THIS PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
DRIER AIR MOVES IN TO CLOSE OUT THE WEEK AS TROUGH DIGS OVER THE
GREAT LAKES SATURDAY AND SUNDAY. GFS AND EURO MODELS HANDLING
FEATURES IN SEPARATE FASHION AND DEFERRED TO HPC GRIDS FOR
EXTENDED PERIOD. NO MAJOR CHANGES TO WPC MEDIUM RANGE GUIDANCE
TEMPERATURES.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z TUESDAY THRU 06Z WEDNESDAY...
SCATTERED SHOWERS CONTINUE PRIMARILY ACROSS THE EASTERN PART OF
THE AREA...WITH THE BACK EDGE OF THE PRECIPITATION CURRENTLY
APPROACHING THE OHIO RIVER. SHOULD A HEAVIER SHOWER DIRECTLY
IMPACT A TERMINAL...BRIEF MVFR VIS MAY RESULT. OTHERWISE EXPECT
SHOWERS TO END FROM WEST TO EAST OVERNIGHT. IFR AND SUB-IFR
CONDITIONS IN FOG AND LOW STRATUS STILL EXPECTED FOR MOST
LOCATIONS BY THE 09Z-12Z TIME FRAME. THIS WILL SCATTER/RISE BY THE
MID-MORNING HOURS WITH VFR CONDITIONS PREVAILING THROUGH THE
REMAINDER OF THE DAY. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO FORM ONCE AGAIN LATE AFTERNOON AND EVENING WHICH MAY
RESULT IN INTERMITTENT MVFR/IFR VIS...WITH MORE GENERAL COVERAGE
OF PRECIP ARRIVING NEAR THE END OF THE VALID PERIOD WITH THE
APPROACH OF A COLD FRONT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: LOW.
ALTERNATE SCENARIOS: TIMING/DENSITY OF FOG AND STRATUS MAY VARY
OVERNIGHT AND EARLY THIS MORNING...AS WELL AS TIMING OF
IMPROVEMENT THIS MORNING.
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.
DATE TUE 07/23/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY L L H H H H H H M H H M
HTS CONSISTENCY L L L L L L L L H H M H
BKW CONSISTENCY H H L M L L M H H H H H
EKN CONSISTENCY L H M L L H H M M H M H
PKB CONSISTENCY L L M H M H L L H H M M
CKB CONSISTENCY H H H H H H M H H H M M
AFTER 06Z WEDNESDAY...
IFR OR WORSE FOG POSSIBLE WEDNESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KMC/30
NEAR TERM...50/30
SHORT TERM...KMC
LONG TERM...KMC
AVIATION...50
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1044 PM CDT WED JUL 24 2013
.UPDATE...
ISSUED AT 955 PM CDT WED JUL 24 2013
FORECAST FOR THE OVERNIGHT LOOKS ON TRACK...WITH ATTENTION TURNING TO
CONVECTION CHANCES TOMORROW. CONSENSUS OF MODELS SEEMS TO KEEP THINGS
DRY THROUGH ABOUT 10-12Z...THEN THINGS GET A BIT MORE INTERESTING.
ONE AREA TO WATCH IS ALONG AND EAST OF INTERSTATE 29. 800 MB WINDS
TURN MORE SOUTHERLY WITH A DECENT SHOT OF THETAE ADVECTION AND
CONVERGENCE ALONG THIS INCREASING LOW LEVEL JET. NAM IS MOST
AGGRESSIVE...AND WOULD SUGGEST A PARCEL LIFTED FROM 800 MB WOULD HAVE
AROUND 1500 J/KG OF CAPE...ALMOST NO CIN AND DECENT SHEAR. THUS IT
WOULD SUGGEST SOME ELEVATED STORMS WOULD BE POSSIBLE AFTER 10Z
THROUGH THE MORNING...MAINLY ALONG AND EAST OF INTERSTATE 29. GIVEN
THE INSTABILITY AND SHEAR A FEW COULD BE SEVERE. HOWEVER THE
GFS...RAP AND HRRR ARE ALL LESS AGGRESSIVE WITH THE CONVERGENCE AND
THETAE ADVECTION...WHILE ALSO STRONGER WITH A CAP AROUND 700 MB. THEY
WOULD SUGGEST THAT MORNING ACTIVITY IN THE EAST DOES NOT GET GOING.
TOUGH TO TELL AT THIS POINT...BUT WOULD PROBABLY LEAN TOWARDS THE
MAJORITY SOLUTION OF STAYING DRY...BUT SOMETHING TO KEEP AN EYE ON.
OTHER AREA TO WATCH WILL BE COMING IN FROM THE NORTHWEST. AS THE LOW
LEVEL JET PICKS UP IN THE WESTERN PLAINS...EXPECT CONVECTION ACROSS
SOUTHEAST MONTANA TO INCREASE IN COVERAGE AND PUSH THROUGH THE HEART
OF SOUTH DAKOTA. SEEMS LIKE THE HRRR AND 4 KM NAM ARE HANDLING THIS
PRETTY WELL. TIMING WOULD PUT THIS INTO OUR FAR WEST AROUND 12-14Z.
COULD SEE A MARGINAL WIND THREAT WITH THIS ACTIVITY WITH DECENT
ELEVATED CAPE AND TURNING OF THE WINDS WITH HEIGHT. TIMING WOULD THEN
MOVE THIS LINE OR AREA OF STORMS INTO INTERSTATE 29 AROUND OR SHORTLY
AFTER NOON AND EXITING THE CWA BY MID AFTERNOON. IF CLOUD COVER
EXISTS FROM MORNING ELEVATED CONVECTION MENTIONED ABOVE...SEVERE RISK
WOULD PROBABLY BE MARGINAL AT BEST AS THIS AREA MOVES ACROSS. HOWEVER
IF THE MORNING ACTION DOES NOT DEVELOP...AND WE ARE ABLE TO HEAT
THROUGH THE FIRST PART OF THE DAY...MAY SEE AN INCREASING SEVERE
THREAT AS THE DAY PROGRESSES. THE BEST POTENTIAL FOR ANY ENHANCED
SEVERE THREAT APPEARS TO BE ACROSS NORTHWEST IOWA AND PORTIONS OF
SOUTHWEST MINNESOTA...IF WE CAN MANAGE TO DESTABILIZE ENOUGH BEFORE
THE ONGOING CONVECTION MOVES IN DURING THE EARLY AFTERNOON. SO
OVERALL...WILL JUST HAVE TO WATCH ACTION CURRENTLY OVER MONTANA AND
WHAT IS ABLE TO POSSIBLY DEVELOP OVERHEAD AFTER 10Z.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 316 PM CDT WED JUL 24 2013
QUIET AFTERNOON ACROSS THE AREA WITH AN ABUNDANT CU FIELD HAVING
DEVELOPED ACROSS THE REGION. WOULD EXPECT THESE CLOUDS TO DISSIPATE
TOWARD SUNSET WITH LOSS OF DAY TIME HEATING. OTHERWISE...HAVE SEEN
ISOLATED THUNDERSTORMS DEVELOP THOUGH NORTHWESTERN NEBRASKA...AND
EVEN AN ISOLATED CELL JUST TO THE SOUTH OF GREGORY COUNTY...IN AN
AREA OF LOW LEVEL CONVERGENCE/STEEP LAPSE RATES/INSTABILITY OVER
THAT AREA. SOME SHORT RANGE MODELS HINTING AT ISOLATED THUNDERSTORM
DEVELOPMENT CONTINUING THROUGH THE LATE AFTERNOON INTO EARLY
EVENING...SO THREW IN SOME SLIGHT POPS IN OUR FAR SOUTHWEST WITH
THIS ACTIVITY. AFTER THAT...ANTICIPATE A BREAK UNTIL LATE TONIGHT
WHEN THETA E ADVECTION BEGINS TO INCREASE IN OUR WEST IN THE ADVANCE
OF ANOTHER SHORTWAVE DROPPING THROUGH THE REGION ON A NORTHWESTERLY
UPPER LEVEL FLOW. WITH THIS...ANTICIPATE THUNDERSTORM ACTIVITY TO
INCREASE OVER THAT AREA TOWARD MORNING...AND BECOME MORE WIDESPREAD
ON THE NOSE OF A POSSIBLE 40 KT LOW LEVEL JET DEVELOPING THROUGH
CENTRAL NEBRASKA. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THIS
SCENARIO...HOWEVER DIFFERING ON THE STRENGTH OF THIS LOW LEVEL
JET...WITH THE NAM BEING MOST ROBUST...AND THE GFS AND ECMWF MUCH
LESS SO...PROGGING A WEAKER JET OF ONLY AROUND 20 KT. THIS BECOMES A
BIGGER PLAYER IN THE POTENTIAL FOR SEVERE WEATHER FOR THURSDAY WITH
THE GFS/ECMWF PROGGING MUCH LIGHT WINDS ALOFT...AND THUS SHEAR IS
LESS IMPRESSIVE AS DIRECTIONAL SHEAR IS NOT OVERLY IMPRESSIVE
EITHER. OTHER PLAYER IN THE SEVERE POTENTIAL FOR THURSDAY WILL BE
WHETHER MORNING CONVECTION/CLOUD COVER WORKS THE ATMOSPHERE OVER FOR
POTENTIAL SEVERE STORMS DURING THE AFTERNOON. STILL LOOKING AT A
COLD FRONT DROPPING INTO THE CWA DURING THE DAY...WITH THE NAM BEING
A LITTLE MORE AGGRESSIVE ON BRINGING THE FRONT THROUGH. WITH LOW
LEVEL CONVERGENCE ALONG THE FRONT...AND SYNOPTIC LIFT INCREASING
ACROSS THE REGION DURING THE DAY PER QG VERTICAL VELOCITY FIELDS AS
A SHORTWAVE ENCROACHES ON THE AREA...THUNDERSTORM DEVELOPMENT LOOKS
PRETTY LIKELY THROUGH THE AFTERNOON. AGAIN...SEVERE POTENTIAL FOR
THE DEPENDS ON THE AFOREMENTIONED FACTORS...BUT IF THE ATMOSPHERE CAN
BECOME UNSTABLE IT SEEMS THAT SOME SEVERE STORMS WOULD BE
PROBABLE...WITH LARGE HAIL/DAMAGING WINDS BEING THE MOST LIKELY
THREATS. IF THE MORE AGGRESSIVE NAM WERE TO VERIFY WITH STRONGER
WINDS...AND 0 TO 1 KM SHEAR OF 20 KTS AND A RELATIVELY LOW
LCL...COULD NOT RULE OUT AN ISOLATED TORNADO. AS FOR TEMPERATURE FOR
TONIGHT AND TOMORROW...LOOKS A LITTLE MILDER TONIGHT WITH LOWS IN
THE UPPER 50S TO MID 60S. TEMPERATURES ARE A BIT TRICKY ON THURSDAY
WITH POTENTIAL CLOUDS/THUNDERSTORM ACTIVITY...BUT GOING FOR UPPER
70S TO LOWER 80S AT THIS POINT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM CDT WED JUL 24 2013
COLD FRONT WILL MOVE SOUTHEAST OUT OF THE FORECAST AREA THURSDAY
NIGHT. ONGOING SHOWERS AND STORMS MAY BE PRETTY WIDESPREAD SOUTHEAST
HALF AT THE START OF THE EVENING AND SEVERE THREAT MAY SILL BE WITH
US AT THE START. CONVECTION WILL DECREASE STEADILY FROM THE
NORTHWEST DURING THE NIGHT AND COOLER AND DRIER AIR WILL FLOW IN.
LOW TEMPERATURES EARLY FRIDAY MORNING SHOULD BE CLOSE TO WHAT WE
HAVE BEEN GOING FOR...JUST WENT THE TINIEST BIT COOLER WITH UPPER
50S TO MID 60S. THE COOLER AND DRY REGIME SHOULD THEN BE IN PLACE
FRIDAY THROUGH MOST OF THE COMING WEEKEND...THOUGH THE CLOSENESS OF
THE UPPER LOW TO THE NORTHEAST SUGGESTS A LOT OF DAYTIME HEATING
CLOUDS IN OUR NORTHEAST GIVEN THE COOL AIR ALOFT AND ASSOCIATED LOW
LEVEL MOISTURE. LOOKS AT PROGGED SOUNDINGS ON BUFKIT SHOW CONDITIONS
WILL BE UNFAVORABLE FURTHER UP FOR SHOWERS SO WILL LEAVE THOSE
OUT. SKIES SHOULD TENS TO MOSTLY CLEAR AT NIGHT...AND WE WILL BE
LOOKING AT TEMPERATURES QUITE A BIT BELOW NORMAL FOR LATE JULY.
THE WARM ADVECTION PATTERN STARTS TO GET GOING SUNDAY AS UPPER LOW
MOVES FURTHER EAST...AND A FAVORABLE PATTERN FOR SCATTERED SHOWERS
AND A FEW THUNDERSTORMS DEVELOPS...WITH THE INITIAL MENTION
EXTREME SOUTHWEST SUNDAY. SUNDAY NIGHT THROUGH THURSDAY WILL THEN
BRING SLOW BUT STEADY WARMING WITH THE SCATTERED PRECIPITATION.
SLOW IN THIS CASE MEANS STAYING A TAD BELOW NORMAL AT LEAST ON
DAYTIME HIGHS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1043 PM CDT WED JUL 24 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 11Z. THEREAFTER...A
FRONT WILL APPROACH FROM THE NORTH AND BECOME THE FOCUSING
MECHANISM FOR SHOWERS AND THUNDERSTORMS. TRIED TO TIME OUT THE
THUNDERSTORMS IN THE TAF...AND VISIBILITY COULD DROP MORE THAN THE
PREVAILING FORECAST VISIBILITY TEMPORARILY IN HEAVIER
THUNDERSTORMS. NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...JM
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
956 PM CDT WED JUL 24 2013
.UPDATE...
ISSUED AT 955 PM CDT WED JUL 24 2013
FORECAST FOR THE OVERNIGHT LOOKS ON TRACK...WITH ATTENTION TURNING TO
CONVECTION CHANCES TOMORROW. CONSENSUS OF MODELS SEEMS TO KEEP THINGS
DRY THROUGH ABOUT 10-12Z...THEN THINGS GET A BIT MORE INTERESTING.
ONE AREA TO WATCH IS ALONG AND EAST OF INTERSTATE 29. 800 MB WINDS
TURN MORE SOUTHERLY WITH A DECENT SHOT OF THETAE ADVECTION AND
CONVERGENCE ALONG THIS INCREASING LOW LEVEL JET. NAM IS MOST
AGGRESSIVE...AND WOULD SUGGEST A PARCEL LIFTED FROM 800 MB WOULD HAVE
AROUND 1500 J/KG OF CAPE...ALMOST NO CIN AND DECENT SHEAR. THUS IT
WOULD SUGGEST SOME ELEVATED STORMS WOULD BE POSSIBLE AFTER 10Z
THROUGH THE MORNING...MAINLY ALONG AND EAST OF INTERSTATE 29. GIVEN
THE INSTABILITY AND SHEAR A FEW COULD BE SEVERE. HOWEVER THE
GFS...RAP AND HRRR ARE ALL LESS AGGRESSIVE WITH THE CONVERGENCE AND
THETAE ADVECTION...WHILE ALSO STRONGER WITH A CAP AROUND 700 MB. THEY
WOULD SUGGEST THAT MORNING ACTIVITY IN THE EAST DOES NOT GET GOING.
TOUGH TO TELL AT THIS POINT...BUT WOULD PROBABLY LEAN TOWARDS THE
MAJORITY SOLUTION OF STAYING DRY...BUT SOMETHING TO KEEP AN EYE ON.
OTHER AREA TO WATCH WILL BE COMING IN FROM THE NORTHWEST. AS THE LOW
LEVEL JET PICKS UP IN THE WESTERN PLAINS...EXPECT CONVECTION ACROSS
SOUTHEAST MONTANA TO INCREASE IN COVERAGE AND PUSH THROUGH THE HEART
OF SOUTH DAKOTA. SEEMS LIKE THE HRRR AND 4 KM NAM ARE HANDLING THIS
PRETTY WELL. TIMING WOULD PUT THIS INTO OUR FAR WEST AROUND 12-14Z.
COULD SEE A MARGINAL WIND THREAT WITH THIS ACTIVITY WITH DECENT
ELEVATED CAPE AND TURNING OF THE WINDS WITH HEIGHT. TIMING WOULD THEN
MOVE THIS LINE OR AREA OF STORMS INTO INTERSTATE 29 AROUND OR SHORTLY
AFTER NOON AND EXITING THE CWA BY MID AFTERNOON. IF CLOUD COVER
EXISTS FROM MORNING ELEVATED CONVECTION MENTIONED ABOVE...SEVERE RISK
WOULD PROBABLY BE MARGINAL AT BEST AS THIS AREA MOVES ACROSS. HOWEVER
IF THE MORNING ACTION DOES NOT DEVELOP...AND WE ARE ABLE TO HEAT
THROUGH THE FIRST PART OF THE DAY...MAY SEE AN INCREASING SEVERE
THREAT AS THE DAY PROGRESSES. THE BEST POTENTIAL FOR ANY ENHANCED
SEVERE THREAT APPEARS TO BE ACROSS NORTHWEST IOWA AND PORTIONS OF
SOUTHWEST MINNESOTA...IF WE CAN MANAGE TO DESTABILIZE ENOUGH BEFORE
THE ONGOING CONVECTION MOVES IN DURING THE EARLY AFTERNOON. SO
OVERALL...WILL JUST HAVE TO WATCH ACTION CURRENTLY OVER MONTANA AND
WHAT IS ABLE TO POSSIBLY DEVELOP OVERHEAD AFTER 10Z.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 316 PM CDT WED JUL 24 2013
QUIET AFTERNOON ACROSS THE AREA WITH AN ABUNDANT CU FIELD HAVING
DEVELOPED ACROSS THE REGION. WOULD EXPECT THESE CLOUDS TO DISSIPATE
TOWARD SUNSET WITH LOSS OF DAY TIME HEATING. OTHERWISE...HAVE SEEN
ISOLATED THUNDERSTORMS DEVELOP THOUGH NORTHWESTERN NEBRASKA...AND
EVEN AN ISOLATED CELL JUST TO THE SOUTH OF GREGORY COUNTY...IN AN
AREA OF LOW LEVEL CONVERGENCE/STEEP LAPSE RATES/INSTABILITY OVER
THAT AREA. SOME SHORT RANGE MODELS HINTING AT ISOLATED THUNDERSTORM
DEVELOPMENT CONTINUING THROUGH THE LATE AFTERNOON INTO EARLY
EVENING...SO THREW IN SOME SLIGHT POPS IN OUR FAR SOUTHWEST WITH
THIS ACTIVITY. AFTER THAT...ANTICIPATE A BREAK UNTIL LATE TONIGHT
WHEN THETA E ADVECTION BEGINS TO INCREASE IN OUR WEST IN THE ADVANCE
OF ANOTHER SHORTWAVE DROPPING THROUGH THE REGION ON A NORTHWESTERLY
UPPER LEVEL FLOW. WITH THIS...ANTICIPATE THUNDERSTORM ACTIVITY TO
INCREASE OVER THAT AREA TOWARD MORNING...AND BECOME MORE WIDESPREAD
ON THE NOSE OF A POSSIBLE 40 KT LOW LEVEL JET DEVELOPING THROUGH
CENTRAL NEBRASKA. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THIS
SCENARIO...HOWEVER DIFFERING ON THE STRENGTH OF THIS LOW LEVEL
JET...WITH THE NAM BEING MOST ROBUST...AND THE GFS AND ECMWF MUCH
LESS SO...PROGGING A WEAKER JET OF ONLY AROUND 20 KT. THIS BECOMES A
BIGGER PLAYER IN THE POTENTIAL FOR SEVERE WEATHER FOR THURSDAY WITH
THE GFS/ECMWF PROGGING MUCH LIGHT WINDS ALOFT...AND THUS SHEAR IS
LESS IMPRESSIVE AS DIRECTIONAL SHEAR IS NOT OVERLY IMPRESSIVE
EITHER. OTHER PLAYER IN THE SEVERE POTENTIAL FOR THURSDAY WILL BE
WHETHER MORNING CONVECTION/CLOUD COVER WORKS THE ATMOSPHERE OVER FOR
POTENTIAL SEVERE STORMS DURING THE AFTERNOON. STILL LOOKING AT A
COLD FRONT DROPPING INTO THE CWA DURING THE DAY...WITH THE NAM BEING
A LITTLE MORE AGGRESSIVE ON BRINGING THE FRONT THROUGH. WITH LOW
LEVEL CONVERGENCE ALONG THE FRONT...AND SYNOPTIC LIFT INCREASING
ACROSS THE REGION DURING THE DAY PER QG VERTICAL VELOCITY FIELDS AS
A SHORTWAVE ENCROACHES ON THE AREA...THUNDERSTORM DEVELOPMENT LOOKS
PRETTY LIKELY THROUGH THE AFTERNOON. AGAIN...SEVERE POTENTIAL FOR
THE DEPENDS ON THE AFOREMENTIONED FACTORS...BUT IF THE ATMOSPHERE CAN
BECOME UNSTABLE IT SEEMS THAT SOME SEVERE STORMS WOULD BE
PROBABLE...WITH LARGE HAIL/DAMAGING WINDS BEING THE MOST LIKELY
THREATS. IF THE MORE AGGRESSIVE NAM WERE TO VERIFY WITH STRONGER
WINDS...AND 0 TO 1 KM SHEAR OF 20 KTS AND A RELATIVELY LOW
LCL...COULD NOT RULE OUT AN ISOLATED TORNADO. AS FOR TEMPERATURE FOR
TONIGHT AND TOMORROW...LOOKS A LITTLE MILDER TONIGHT WITH LOWS IN
THE UPPER 50S TO MID 60S. TEMPERATURES ARE A BIT TRICKY ON THURSDAY
WITH POTENTIAL CLOUDS/THUNDERSTORM ACTIVITY...BUT GOING FOR UPPER
70S TO LOWER 80S AT THIS POINT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM CDT WED JUL 24 2013
COLD FRONT WILL MOVE SOUTHEAST OUT OF THE FORECAST AREA THURSDAY
NIGHT. ONGOING SHOWERS AND STORMS MAY BE PRETTY WIDESPREAD SOUTHEAST
HALF AT THE START OF THE EVENING AND SEVERE THREAT MAY SILL BE WITH
US AT THE START. CONVECTION WILL DECREASE STEADILY FROM THE
NORTHWEST DURING THE NIGHT AND COOLER AND DRIER AIR WILL FLOW IN.
LOW TEMPERATURES EARLY FRIDAY MORNING SHOULD BE CLOSE TO WHAT WE
HAVE BEEN GOING FOR...JUST WENT THE TINIEST BIT COOLER WITH UPPER
50S TO MID 60S. THE COOLER AND DRY REGIME SHOULD THEN BE IN PLACE
FRIDAY THROUGH MOST OF THE COMING WEEKEND...THOUGH THE CLOSENESS OF
THE UPPER LOW TO THE NORTHEAST SUGGESTS A LOT OF DAYTIME HEATING
CLOUDS IN OUR NORTHEAST GIVEN THE COOL AIR ALOFT AND ASSOCIATED LOW
LEVEL MOISTURE. LOOKS AT PROGGED SOUNDINGS ON BUFKIT SHOW CONDITIONS
WILL BE UNFAVORABLE FURTHER UP FOR SHOWERS SO WILL LEAVE THOSE
OUT. SKIES SHOULD TENS TO MOSTLY CLEAR AT NIGHT...AND WE WILL BE
LOOKING AT TEMPERATURES QUITE A BIT BELOW NORMAL FOR LATE JULY.
THE WARM ADVECTION PATTERN STARTS TO GET GOING SUNDAY AS UPPER LOW
MOVES FURTHER EAST...AND A FAVORABLE PATTERN FOR SCATTERED SHOWERS
AND A FEW THUNDERSTORMS DEVELOPS...WITH THE INITIAL MENTION
EXTREME SOUTHWEST SUNDAY. SUNDAY NIGHT THROUGH THURSDAY WILL THEN
BRING SLOW BUT STEADY WARMING WITH THE SCATTERED PRECIPITATION.
SLOW IN THIS CASE MEANS STAYING A TAD BELOW NORMAL AT LEAST ON
DAYTIME HIGHS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 639 PM CDT WED JUL 24 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 09Z. THEREAFTER...A
FRONT WILL APPROACH FROM THE NORTH AND BECOME THE FOCUSING
MECHANISM FOR SHOWERS AND THUNDERSTORMS. TRIED TO TIME OUT THE
THUNDERSTORMS IN THE TAF...AND VISIBILITY COULD DROP MORE THAN THE
PREVAILING FORECAST VISIBILITY IN HEAVIER THUNDERSTORMS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...JM
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
139 PM MDT TUE JUL 23 2013
.SYNOPSIS...
A MOIST WEATHER PATTERN WILL PERSIST WITH HUMID AIR TRAPPED BELOW
EXPANDING UPPER LEVEL HIGH PRESSURE. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP EACH AFTERNOON OVER THE MOUNTAINS AND SPREAD
INTO THE LOWLANDS DURING THE EVENING THROUGH FRIDAY.
THE NUMBER AND INTENSITY OF THE STORMS MAY INCREASE OVER THE
WEEKEND AS A BACKDOOR COLD FRONT MOVES TOWARD THE REGION. IT IS
UNCERTAIN WHETHER THE FRONT WILL MOVE THROUGH THE AREA...BUT IT
SHOULD BE CLOSE ENOUGH TO DRAW IN ADDITIONAL MOISTURE AND INCREASE
THE RISK OF LOCALIZED FLOODING.
SOMEWHAT DRIER SURFACE AIR SHOULD FILTER INTO THE REGION BEGINNING
MONDAY WITH A CORRESPONDING REDUCTION IN THUNDERSTORMS.
WITH LOTS OF CLOUDS AROUND TEMPERATURES THROUGH THE PERIOD SHOULD
GENERALLY RUN NEAR NORMAL.
&&
.DISCUSSION...
NO LARGE CHANGES IN PATTERN WITH UPPER HIGH CONTINUING TO SPREAD
OVER THE CWA. THE FLY IN THE OINTMENT IS THE PERSISTING INVERTED
TROUGH MOVING SLOWLY WEST ACROSS NORTHERN MEXICO. THE TROUGH OR A
SMALL REMNANT WILL PERSIST NEAR/OVER THE CWA THROUGH SUNDAY KEEPING
A FAIRLY ACTIVE WEATHER PATTERN THROUGH THAT TIME.
ON THE SHORTER TERM...THE HIGH RES MODELS INCLUDING HRRR HAVE NOT
PERFORMED WELL SO FAR TODAY SHOWING EXTENSIVE PRECIP OVER SW NM
FOR THIS MORNING WHICH NEVER MATERIALIZED PROBABLY DUE TO TOO MUCH
LOW-LEVEL CIN. LATEST HRRR/12Z SPC WRF INDICATED AFTERNOON/EVENING
CONVECTION FOR THE SW ONCE AGAIN AND AN EVENING BATCH OF CONVECTION
MOVING ACROSS SOUTHERN TIER. HAVE ADJUSTED POPS TO REFLECT THESE
TRENDS HOPING THAT THE EARLIER PROBLEMS HAVE BEEN FLUSHED OUT OF
THE SYSTEM WITH LATER MODEL INITIALIZATIONS.
MODEL OMEGAS INCREASE TOMORROW SO I EXPECT A GREATER COVERAGE OF
STORMS THROUGHOUT THE AREA FOLLOWED BY A RETURN TO A BASELINE
COVERAGE FOR THURSDAY AND FRIDAY. SLOW MOVEMENT SHOULD
CHARACTERIZE STORMS THROUGH FRIDAY WHICH WILL MEAN A DECENT RISK
OF AT LEAST LOCALIZED FLOODING. HAVE NO INCLINATION TO ISSUE FFA
ATTM BUT IT IS SOMETHING THAT WILL NEED TO BE WATCHED EACH SHIFT
FOR THE NEXT SEVERAL DAYS.
THE WEEKEND REMAINS IN DOUBT REGARDING THE POSITIONING OF A
BACKDOOR COLD FRONT. CURRENT MODELS ARE HANGING THE FRONT ON THE
SACS FOR SATURDAY - I AM SKEPICAL. REGARDLESS WHETHER THE FRONT
ACTUALLY PENETRATES THE AREA...THERE SHOULD BE ENOUGH MOISTURE
CHANNELED INTO FRONT TO PRODUCE SCATTERED TO NUMEROUS STORMS FOR
SATURDAY AND SUNDAY. THE MAIN ISSUE WILL BE WHETHER WE SEE STRONG
TO SEVERE STORMS AND HEAVIER RAIN WITH ISENTROPIC LIFT.
IT APPEARS THAT THE UPPER LOW FINALLY MOVES OUT OF THE AREA MONDAY
AND SOME DRYING TAKES PLACE AT THE SURFACE SO POPS SHOULD DECREASE.
&&
.AVIATION...VALID 24/00Z-25/00Z.
SCATTERED TSRA OVER THE MOUNTAINS WITH ISOLATED TO WIDELY SCATTERED
TSRA IN THE LOWLANDS. STORMS WILL TEND TO DRIFT TOWARDS THE W OR
WSW. GNLY FEW-SCT050-070 SCT-BKN100-140 SCT-BKN200-250 WITH LCL 3SM
+TSRAGS BKN040CB OVC080 AND BRIEF MVFR IN STORMS GNLY 18Z-06Z. SVR
TURBC PSBL WITH 10 MI CB/TSTM. WNDS GNLY 21010KTS WITH VRB 30G40KTS
NR TSTMS.
&&
.FIRE WEATHER...
A WEAK TO MODERATE MONSOONAL PATTERN WILL CONTINUE FOR MOST OF REST
OF THE WEEK. WITH A SEMI STALLED LOW PRESSURE SYSTEM JUST SOUTH OF
THE BORDER...THIS PATTERN WILL FAVOR HEAVIER RAINFALL ESPECIALLY FOR
FOR AREAS WEST OF THE CONTINENTAL DIVIDE. HOWEVER AFTERNOON OR
NIGHTTIME SHOWERS AND THUNDERSTORMS ARE POSSIBLE JUST ABOUT ANYWHERE
WITH THIS MOIST UNSTABLE AIR MASS IN PLACE. BY THE WEEKEND...A
BACKDOOR COLD FRONT MAY APPROACH OUR AREA FROM THE NORTHEAST WHICH
COULD ALLOW FOR EVEN MORE ADDITIONAL TROPICAL MOISTURE INTO THE
REGION RESULTING IN AN INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS.
MIN RH WILL RANGE FROM 30% TO 45% ALL AREAS TODAY AND WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 76 91 74 92 74 / 30 40 40 30 30
SIERRA BLANCA 71 90 70 93 71 / 40 40 40 30 30
LAS CRUCES 72 90 69 89 70 / 30 40 50 30 30
ALAMOGORDO 73 91 70 92 71 / 30 40 50 30 30
CLOUDCROFT 53 66 50 68 52 / 30 50 50 30 30
TRUTH OR CONSEQUENCES 71 89 68 88 69 / 30 40 50 40 30
SILVER CITY 64 83 63 81 63 / 40 50 60 40 40
DEMING 71 90 68 87 68 / 30 40 50 40 30
LORDSBURG 69 90 67 87 68 / 40 40 50 40 30
WEST EL PASO METRO 76 90 74 91 75 / 30 40 40 30 30
DELL CITY 70 94 70 94 71 / 30 40 40 30 20
FORT HANCOCK 74 93 73 96 73 / 40 40 40 30 30
LOMA LINDA 68 85 67 87 68 / 30 40 40 30 30
FABENS 74 91 73 92 74 / 40 40 40 30 30
SANTA TERESA 73 90 71 90 72 / 30 40 40 30 30
WHITE SANDS HQ 74 90 72 90 73 / 30 40 40 30 30
JORNADA RANGE 69 89 67 89 68 / 30 40 50 30 30
HATCH 72 87 69 86 71 / 30 40 50 30 30
COLUMBUS 71 90 71 88 69 / 30 40 50 30 30
OROGRANDE 72 91 70 92 71 / 30 40 40 30 30
MAYHILL 59 75 57 76 59 / 30 40 40 30 30
MESCALERO 57 78 55 79 57 / 30 50 50 30 30
TIMBERON 58 75 57 75 59 / 30 40 40 30 30
WINSTON 62 81 60 80 61 / 40 40 50 40 40
HILLSBORO 68 85 65 83 66 / 30 50 60 40 30
SPACEPORT 70 89 68 87 69 / 30 40 50 30 30
LAKE ROBERTS 63 82 61 81 62 / 40 50 60 40 40
HURLEY 65 85 64 82 64 / 40 40 60 40 40
CLIFF 68 91 66 87 66 / 40 40 50 40 40
MULE CREEK 61 86 60 83 60 / 40 50 50 40 30
FAYWOOD 67 84 65 81 66 / 30 40 60 40 30
ANIMAS 68 88 68 85 68 / 40 40 50 30 30
HACHITA 68 89 67 86 68 / 40 40 50 40 30
ANTELOPE WELLS 66 86 66 84 66 / 40 40 50 40 30
CLOVERDALE 65 82 64 80 64 / 40 50 60 40 40
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
02/20
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1144 PM CDT MON JUL 22 2013
.DISCUSSION...
SEE AVIATION SECTION FOR DISCUSSION ON THE 06Z TAF PACKAGE.
&&
.AVIATION...
SKIES WILL BE MOSTLY CLEAR ACROSS WEST CENTRAL TEXAS UNTIL LATE
TONIGHT. LOW CLOUDS...CURRENTLY DEVELOPING OVER THE HILL COUNTRY
REGION...WILL EXPAND/DEVELOP NORTH ACROSS THE SOUTHEASTERN PART
OF WEST CENTRAL TEXAS BETWEEN 09Z AND 11Z. EXPECTING MVFR CEILINGS
AND BASES WITH THESE LOW CLOUDS. CARRYING A LOW CLOUD MENTION
MAINLY AT KJCT...KBBD AND KSOA. KSJT MAY BRIEFLY HAVE LOW CLOUDS
IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL ERODE BY MID-
LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD ONCE AGAIN
DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE THAN WHAT
OCCURRED TODAY. SOUTH-SOUTHEAST WINDS 4-7 KT ARE EXPECTED OVERNIGHT.
BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT OVERALL...WITH GUSTS
AT TIMES TO 20 KT AT KABI AND KSJT.
19
&&
.PREV DISCUSSION... /ISSUED 1004 PM CDT MON JUL 22 2013/
UPDATE...
SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX WITH THE LOSS OF
DAYTIME HEATING. THE HRRR SUGGESTS WE MAY SEE A FEW MORE SHOWERS
DURING THE OVERNIGHT HOURS BUT WITH STABILITY INCREASING...I THINK
THAT IS A LONG SHOT. THE FORECAST IS DRY THROUGH THE REMAINDER OF
THE NIGHT WITH TEMPERATURES FALLING INTO THE LOWER 70S. MINOR
CHANGES WERE MADE TO WIND...DEWPOINT AND SKY FOR THE FIRST AND
SECOND PERIODS GRIDS BUT THE REMAINDER OF THE FORECAST REMAINS ON
TRACK.
JOHNSON
PREV DISCUSSION... /ISSUED 647 PM CDT MON JUL 22 2013/
DISCUSSION...
SEE AVIATION SECTION.
AVIATION...
WHILE AN ISOLATED SHOWER REMAINS POSSIBLE THIS EVENING BEFORE
SUNSET...THE CHANCE OF OCCURRENCE NEAR A TAF SITE IS REMOTE.
PLAN TO OMIT THE MENTION OF SHRA AFTER 00Z. THE CUMULUS FIELD
WILL DISSIPATE BY LATE EVENING WITH CLEAR SKIES FOR MUCH OF
TONIGHT. TOWARD MORNING...EXPECT A LOW CLOUD FIELD TO DEVELOP
ACROSS THE SOUTHEASTERN PART OF OUR AREA...WITH MVFR CEILINGS
AND BASES. CARRYING A LOW CLOUD MENTION MAINLY AT KJCT AND
KBBD...AND TO A LESSER EXTENT AT KSOA. KSJT MAY BRIEFLY HAVE
LOW CLOUDS IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL
ERODE BY MID-LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD
ONCE AGAIN DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE
THAN WHAT OCCURRED TODAY. SOUTH-SOUTHEAST WINDS WILL CONTINUE
TONIGHT AND TUESDAY. BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT
OVERALL...WITH GUSTS AT TIMES TO 20 KT AT KABI AND KSJT.
19
PREV DISCUSSION... /ISSUED 350 PM CDT MON JUL 22 2013/
SHORT TERM...
/TONIGHT AND TUESDAY/
A WEAK UPPER LEVEL LOW CURRENTLY OVER NORTHERN CHIHUAHUA WILL
WEAKEN THROUGH TUESDAY AS HIGH PRESSURE ALOFT BEGINS TO BUILD
SOUTHEAST ACROSS THE AREA. WE ARE STILL SEEING AFFECTS FROM THE
UPPER LOW AS MOISTURE REMAINS HIGH AND ISOLATED TO WIDELY
SCATTERED CONVECTION HAS ONCE AGAIN DEVELOPED ACROSS THE AREA THIS
AFTERNOON. KEPT SLIGHT POPS GOING THROUGH EARLY EVENING ACROSS THE
SOUTHERN TWO THIRDS OF THE CWA WITH ISOLATED MENTION ACROSS A
PORTION OF THE BIG COUNTRY. BRIEF HEAVY RAINFALL WILL BE POSSIBLE
ALONG WITH A FEW CLOUD TO GROUND LIGHTNING STRIKES. CONVECTION
WILL DISSIPATE AFTER SUNSET WITH LOSS OF HEATING.
ANOTHER ROUND OF STRATUS WILL DEVELOP ACROSS MAINLY SOUTHERN
SECTIONS TOWARDS DAYBREAK...SCATTERING OUT BY MID MORNING. COULD
STILL SEE AN ISOLATED SHOWER DEVELOP ACROSS SOUTHERN SECTIONS
TUESDAY AFTERNOON BUT WITH HIGH PRESSURE BUILDING IN WILL LEAVE
POPS OUT OF THE FORECAST. LOWS TONIGHT WILL BE IN THE 70S WITH
HIGHS ON TUESDAY RANGING FROM THE LOW TO MID 90S SOUTH TO THE
UPPER 90S NORTH.
24
LONG TERM...
/TUESDAY NIGHT INTO MONDAY/
HOT AND DRY MIDWEEK THEN A SLIGHT CHANCE OF THUNDERSTORMS FOR
THE BIG COUNTRY FRIDAY...
DISCUSSION...
UPPER RIDGE STRENGTHENS MIDWEEK...TEMPORARILY ENDING RAIN
CHANCES. GFS AND EC MODELS BRING A WEAK COLD FRONT INTO NORTHERN
TEXAS FRIDAY NIGHT. THE GFS MODEL BRINGS IT ALONG THE RED
RIVER... WHILE THE EC HAS BRINGS IT AS FAR SOUTH AS THE
INTERSTATE 20 CORRIDOR. WILL CONTINUE TO MAINTAIN A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR THE BIG COUNTRY FRIDAY AND
FRIDAY NIGHT. HOWEVER...AS UPPER RIDGING WILL NOT BE WEAKENING...
THERE REMAINS CONSIDERABLE UNCERTAINTY IN STORM DEVELOPMENT.
HAVE TRENDED TOWARD A GRADUAL INCREASE IN TEMPERATURES MIDWEEK
WITH DECREASE IN CUMULUS. OVERNIGHT LOWS CONTINUE IN THE LOWER
TO MID 70S.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 74 96 73 96 73 / 5 10 5 5 5
SAN ANGELO 74 96 73 96 72 / 10 5 0 5 0
JUNCTION 74 95 73 96 72 / 10 5 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1141 PM CDT MON JUL 22 2013
.DISCUSSION...
&&
.AVIATION...
SKIES WILL BE MOSTLY CLEAR ACROSS WEST CENTRAL TEXAS UNTIL LATE
TONIGHT. LOW CLOUDS...CURRENTLY DEVELOPING OVER THE HILL COUNTRY
REGION...WILL EXPAND/DEVELOP NORTH ACROSS THE SOUTHEASTERN PART
OF WEST CENTRAL TEXAS BETWEEN 09Z AND 11Z. EXPECTING MVFR CEILINGS
AND BASES WITH THESE LOW CLOUDS. CARRYING A LOW CLOUD MENTION
MAINLY AT KJCT...KBBD AND KSOA. KSJT MAY BRIEFLY HAVE LOW CLOUDS
IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL ERODE BY MID-
LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD ONCE AGAIN
DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE THAN WHAT
OCCURRED TODAY. SOUTH-SOUTHEAST WINDS 4-7 KT ARE EXPECTED OVERNIGHT.
BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT OVERALL...WITH GUSTS
AT TIMES TO 20 KT AT KABI AND KSJT.
19
&&
.PREV DISCUSSION... /ISSUED 1004 PM CDT MON JUL 22 2013/
UPDATE...
SHOWERS HAVE DISSIPATED ACROSS WEST CENTRAL TX WITH THE LOSS OF
DAYTIME HEATING. THE HRRR SUGGESTS WE MAY SEE A FEW MORE SHOWERS
DURING THE OVERNIGHT HOURS BUT WITH STABILITY INCREASING...I THINK
THAT IS A LONG SHOT. THE FORECAST IS DRY THROUGH THE REMAINDER OF
THE NIGHT WITH TEMPERATURES FALLING INTO THE LOWER 70S. MINOR
CHANGES WERE MADE TO WIND...DEWPOINT AND SKY FOR THE FIRST AND
SECOND PERIODS GRIDS BUT THE REMAINDER OF THE FORECAST REMAINS ON
TRACK.
JOHNSON
PREV DISCUSSION... /ISSUED 647 PM CDT MON JUL 22 2013/
DISCUSSION...
SEE AVIATION SECTION.
AVIATION...
WHILE AN ISOLATED SHOWER REMAINS POSSIBLE THIS EVENING BEFORE
SUNSET...THE CHANCE OF OCCURRENCE NEAR A TAF SITE IS REMOTE.
PLAN TO OMIT THE MENTION OF SHRA AFTER 00Z. THE CUMULUS FIELD
WILL DISSIPATE BY LATE EVENING WITH CLEAR SKIES FOR MUCH OF
TONIGHT. TOWARD MORNING...EXPECT A LOW CLOUD FIELD TO DEVELOP
ACROSS THE SOUTHEASTERN PART OF OUR AREA...WITH MVFR CEILINGS
AND BASES. CARRYING A LOW CLOUD MENTION MAINLY AT KJCT AND
KBBD...AND TO A LESSER EXTENT AT KSOA. KSJT MAY BRIEFLY HAVE
LOW CLOUDS IN THE VICINITY BY 13-14Z. THE LOW CLOUD FIELD WILL
ERODE BY MID-LATE MORNING. SHOULD HAVE A DIURNAL CUMULUS FIELD
ONCE AGAIN DURING THE DAY TUESDAY...BUT WITH LESS CLOUD COVERAGE
THAN WHAT OCCURRED TODAY. SOUTH-SOUTHEAST WINDS WILL CONTINUE
TONIGHT AND TUESDAY. BY MIDDAY TUESDAY EXPECT SOUTH WINDS 10-15 KT
OVERALL...WITH GUSTS AT TIMES TO 20 KT AT KABI AND KSJT.
19
PREV DISCUSSION... /ISSUED 350 PM CDT MON JUL 22 2013/
SHORT TERM...
/TONIGHT AND TUESDAY/
A WEAK UPPER LEVEL LOW CURRENTLY OVER NORTHERN CHIHUAHUA WILL
WEAKEN THROUGH TUESDAY AS HIGH PRESSURE ALOFT BEGINS TO BUILD
SOUTHEAST ACROSS THE AREA. WE ARE STILL SEEING AFFECTS FROM THE
UPPER LOW AS MOISTURE REMAINS HIGH AND ISOLATED TO WIDELY
SCATTERED CONVECTION HAS ONCE AGAIN DEVELOPED ACROSS THE AREA THIS
AFTERNOON. KEPT SLIGHT POPS GOING THROUGH EARLY EVENING ACROSS THE
SOUTHERN TWO THIRDS OF THE CWA WITH ISOLATED MENTION ACROSS A
PORTION OF THE BIG COUNTRY. BRIEF HEAVY RAINFALL WILL BE POSSIBLE
ALONG WITH A FEW CLOUD TO GROUND LIGHTNING STRIKES. CONVECTION
WILL DISSIPATE AFTER SUNSET WITH LOSS OF HEATING.
ANOTHER ROUND OF STRATUS WILL DEVELOP ACROSS MAINLY SOUTHERN
SECTIONS TOWARDS DAYBREAK...SCATTERING OUT BY MID MORNING. COULD
STILL SEE AN ISOLATED SHOWER DEVELOP ACROSS SOUTHERN SECTIONS
TUESDAY AFTERNOON BUT WITH HIGH PRESSURE BUILDING IN WILL LEAVE
POPS OUT OF THE FORECAST. LOWS TONIGHT WILL BE IN THE 70S WITH
HIGHS ON TUESDAY RANGING FROM THE LOW TO MID 90S SOUTH TO THE
UPPER 90S NORTH.
24
LONG TERM...
/TUESDAY NIGHT INTO MONDAY/
HOT AND DRY MIDWEEK THEN A SLIGHT CHANCE OF THUNDERSTORMS FOR
THE BIG COUNTRY FRIDAY...
DISCUSSION...
UPPER RIDGE STRENGTHENS MIDWEEK...TEMPORARILY ENDING RAIN
CHANCES. GFS AND EC MODELS BRING A WEAK COLD FRONT INTO NORTHERN
TEXAS FRIDAY NIGHT. THE GFS MODEL BRINGS IT ALONG THE RED
RIVER... WHILE THE EC HAS BRINGS IT AS FAR SOUTH AS THE
INTERSTATE 20 CORRIDOR. WILL CONTINUE TO MAINTAIN A SLIGHT CHANCE
OF SHOWERS AND THUNDERSTORMS FOR THE BIG COUNTRY FRIDAY AND
FRIDAY NIGHT. HOWEVER...AS UPPER RIDGING WILL NOT BE WEAKENING...
THERE REMAINS CONSIDERABLE UNCERTAINTY IN STORM DEVELOPMENT.
HAVE TRENDED TOWARD A GRADUAL INCREASE IN TEMPERATURES MIDWEEK
WITH DECREASE IN CUMULUS. OVERNIGHT LOWS CONTINUE IN THE LOWER
TO MID 70S.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 74 96 73 96 73 / 5 10 5 5 5
SAN ANGELO 74 96 73 96 72 / 10 5 0 5 0
JUNCTION 74 95 73 96 72 / 10 5 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1134 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT WILL HEAD SOUTH OF THE AREA OVERNIGHT...AND ITS
ASSOCIATED UPPER TROUGH WILL CROSS THE REGION ON THURSDAY. HIGH
PRESSURE WILL SETTLE OVER THE AREA BY FRIDAY...AND SHIFT EAST TO
THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE THROUGH THE
AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 1130 PM EDT WEDNESDAY...
MODELS HAVE BEEN DOING PRETTY GOOD IN ADVERTISING CONVECTION OVER
THE PIEDMONT THIS EVENING AND STEERING IT WORD THE NC/VA BORDER.
WILL MAINTAIN CHANCE POPS...AS HIGH AS 50 ACROSS THE FAR SE THEN
TAPER TO SLIGHT FURTHER NW ACROSS THE FOOTHILLS OVERNIGHT.
PREVIOUS DISCUSSION...
AS OF 730 PM...
AN AXIS OF HIGHER INSTABILITY AND DECENT LOW LVL LAPSE RATES
EXISTS FROM WRN NC EAST INTO THE PIEDMONT OF NC/VA WITH SUBSIDENCE
AND DRIER AIR WORKING TOWARD SOUTHEAST WV. RADAR AT THE MOMENT
SHOWS CONVECTION SLOWLY TRUDGING EAST ACROSS THE BLUE RIDGE
MOUNTAINS AND FOOTHILLS NORTH OF LYNCHBURG VA...WITH ISOLATED
SHOWERS AND STORMS STARTING TO FADE FROM NE TN INTO THE FOOTHILLS
OF NORTH CAROLINA.
KEPT HIGHER POPS SITUATED ACROSS THE NORTHEAST PIEDMONT OF
BUCKINGHAM SOUTH TO SOUTHSIDE VA AND THEN WEST TOWARD WILKES
COUNTY NC THIS EVENING WITH DRIER WX IN THE NORTHWEST.
18Z NAM/GFS...12Z ECMWF AND THE LATEST HRRR SHOWING OVERALL
AGREEMENT IN BRING A CLUSTER OF SHOWERS/STORMS ACROSS THE
SOUTHEAST CWA AROUND 03Z AS THE UPPER SHORTWAVE MOVES EAST OF OUT
TN. BUMPED POPS UP SOME HERE AND MAY NEED TO GO EVEN HIGHER IF
THIS HAPPENS. BIG CONSIDERATION IS INSTABILITY WEAKENING AS SUN
SETS BUT GIVEN HOW WARM IT IS OUT THERE NOW AND ADDING SOME UPPER
LIFT...THINKING IS CONVECTION SHOULD MAINTAIN ITSELF ACROSS THE
NORTH CAROLINA FOOTHILLS PIEDMONT AND NWD TOWARD SOUTHSIDE VA INTO
THE OVERNIGHT HOURS...WITH THE LIGHTNING SIDE OF THINGS SUBSIDING
OVERNIGHT.
PREVIOUS VALID DISCUSSION...
THE FRONT IS EXPECTED TO HAVE MOVED SOUTH THROUGH MOST...IF NOT
ALL...OF THE REGION BY MIDNIGHT. BEHIND THE FRONT...SURFACE AND
LOW LEVELS WINDS ARE PROGGED TO VEER NORTHEAST TO ALMOST EAST IN
SOME AREAS. THIS WILL HAVE THE IMPACT OF KEEPING LINGERING
MOISTURE IN THE BOUNDARY LAYER PINNED UP AGAINST THE CREST OF THE
BLUE RIDGE. WE ARE EXPECTING STRATUS CLOUDS TO DEVELOP OVERNIGHT
AND LOWER AS THE NIGHT PROGRESSES. THIS MAY ALSO HELP YIELD SOME
DRIZZLE IN THE CREST OF THE BLUE RIDGE. PATCHY OR AREAS OF FOG ARE
ALSO EXPECTED ALONG AND NEAR THE PORTION OF THE BLUE RIDGE
SOUTHWEST OF ROANOKE. THE PROXIMITY OF THE FRONT WILL ALSO HELP
MAINTAIN SOME SHOWERS ACROSS THE SOUTHEAST PART OF THE REGION. LOW
TEMPERATURES TONIGHT WILL BE AROUND 5 TO 8 DEGREES COOLER THAN
TEMPERATURES REALIZED THIS MORNING THANKS TO LOWERING DEW POINTS
BEHIND THE FRONT.
ON THURSDAY...CLOUD COVER WILL BE SLOW TO ERODE...ESPECIALLY ALONG
AND EAST OF THE BLUE RIDGE SOUTHWEST OF ROANOKE. THIS REGION WILL BE
CLOSEST TO THE DEPARTING COLD FRONT AS IT DEVELOPS A SMALL BUCKLE IN
IT WITH THE PASSAGE OF THE PARENT UPPER TROUGH. ALSO...SURFACE
AND LOW LEVEL WINDS WILL HAVE A GREATER EASTERLY COMPONENT. THIS
POINTS TOWARDS THE AREA KEEPING THE CLOUDS LONGER WITH ISOLATED TO
SCATTERED SHOWERS AND A FEW STORMS. HIGHS TOMORROW WILL BE SIMILAR
OR ONLY SLIGHTLY COOLER THAN TEMPERATURES OF TODAY ACROSS THE
MOUNTAINS. OVER THE PIEDMONT...HIGHS WILL BE AROUND 10 DEGREES
COOLER THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
THE SHORT TERM WILL BE DOMINATED BY A BROAD EASTERN U.S.
TROUGH...CONTINUALLY REINFORCED BY UPSTREAM SHORT WAVES. AT THE
BEGINNING OF THE SHORT TERM...THE TROUGH AXIS ATTEMPTS TO SHIFT EAST
OF THE AREA AS A COASTAL LOW MOVES UP AND JUST OFF THE MID-ATLANTIC
COAST. HOWEVER...A STRONG UPSTREAM SHORT WAVE MOVING SOUTHEAST OUT
OF ALBERTA...WILL SHIFT THE TROUGH AXIS BACK INTO THE OHIO VALLEY BY
SATURDAY. WITH SUBSIDENCE EXPECTED BEHIND THE DEPARTING COASTAL LOW
AND NOTABLY DRY AIR...DEW POINTS IN THE 50S/LOW 60S...ADVECTING INTO
THE NW HALF OF THE CWA...HAVE CONFINED SLIGHT CHC POPS TO THE FAR
SOUTHEAST AND POTENTIAL EASTERLY FLOW UPSLOPE AREAS IN THE NW NC
MOUNTAINS AT THE BEGINNING. UPSLOPE EASTERLY FLOW WILL INCREASE
SATURDAY ALONG THE ALLEGHANYS AND BLUE RIDGE OF NW NC...SO HAVE
CONTINUED TO INCREASE POPS IN THE WESTERN AREAS AS A RESULT FOR FRI
AFTERNOON. BY SATURDAY...OUR ATTENTION TURNS TO THE UPSTREAM DIGGING
TROUGH...WHICH SHOULD BE THE NEXT WIDESPREAD PCPN EVENT FOR OUR CWA.
TOO FAR OUT TO BE CONCERNED ABOUT RAINFALL AMOUNTS...BUT THIS WOULD
BE THE NEXT TIME FRAME FOR ANY SIGNIFICANT SEVERE OR FLASH FLOOD
THREAT. HAVE GONE AHEAD AND ADVERTISED LIKELY POPS FOR SAT
AFTERNOON/EVENING IN THE WEST.
SOMEWHAT COOLER MIN TEMPS WILL BE NOTED AT THE
BEGINNING...ESPECIALLY IN THE WEST WITH DEWPOINTS DROPPING INTO THE
50S ACROSS THE ALLEGHANYS. LOWS SHOULD BE IN THE MID TO UPPER 50S IN
THE HIGHER ELEVATIONS ACROSS SW VA/NW NC/SE WV. BY SATURDAY...WITH
SW FLOW RETURNING AND INCREASING MOISTURE...MIN TEMPERATURES WILL
CREEP CLOSER TO NORMAL. MAX TEMPS SHOULD AVERAGE JUST BELOW NORMAL
THROUGH THE PERIOD. OVERALL...CONTINUED BELOW NORMAL AS MOST OF THIS
SUMMER HAS BEEN SO FAR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
AS OF 730 PM EDT WEDNESDAY...
GOING TO HAVE TO WATCH CONVECTION INTO OVERNIGHT AS MODELS SHOWING
BETTER CONCENTRATION AFFECTING THE DANVILLE AREA. WILL HOLD OFF
ADDING PREDOMINANT SHOWERS HERE BUT WILL HAVE VCSH AT 03Z TIL 05Z.
AMENDMENTS WILL OCCUR IF SOMETHING LOOKS TO BE HEADING THAT WAY.
THE WIND FLOW OVERNIGHT WILL BE WEAK AND VARY FROM THE NORTHWEST
TO THE NORTHEAST. MODELS ATTEMPTING TO SHOW EITHER A FOG OR
STRATUS SCENARIO AS THE LOW LVL WINDS TURN MORE TOWARD THE
NORTHEAST.
THINKING THAT FOG WILL BE MORE PROBLEMATIC IN THE MOUNTAINS WITH
SOME STRATUS FORMING ALONG AND WEST OF THE BLUE RIDGE BRINGING
CIGS TO MVFR...WITH POSSIBLE IFR/LIFR AT LWB/BLF/BCB. THINK THE
PIEDMONT CLOUDS UP AS WELL BUT CIGS HERE SHOULD STAY VFR OR MAYBE
HIGH END MVFR. WILL HAVE TO WATCH LYH FOR POTENTIAL FOG GIVEN THE
SHOWERS NEARBY THIS EVENING.
FOR THURSDAY...THE FLOW REMAINS OUT OF THE NORTHEAST TO AT TIME
EAST...SO CIGS MAY LINGER THROUGH THIS PERIOD...WITH VFR EXPECTED
AFTER 14-16Z. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH OF ROANOKE BUT CANNOT RULE OUT BCB/ROA AND MAYBE EVEN BLF
SEEING SHOWERS OR STORMS NEARBY.
THURSDAY EVENING...THE AXIS OF THE UPPER TROUGH PASSES OVERHEAD.
EVEN THOUGH DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN
ISSUE AT BCB/LWB GIVEN WET SOILS AND LIGHT WIND.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...DS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
748 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT WILL HEAD SOUTH OF THE AREA OVERNIGHT...AND ITS
ASSOCIATED UPPER TROUGH WILL CROSS THE REGION ON THURSDAY. HIGH
PRESSURE WILL SETTLE OVER THE AREA BY FRIDAY...AND SHIFT EAST TO
THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE THROUGH THE
AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 730 PM EDT WEDNESDAY...
AN AXIS OF HIGHER INSTABILITY AND DECENT LOW LVL LAPSE RATES
EXISTS FROM WRN NC EAST INTO THE PIEDMONT OF NC/VA WITH SUBSIDENCE
AND DRIER AIR WORKING TOWARD SOUTHEAST WV. RADAR AT THE MOMENT
SHOWS CONVECTION SLOWLY TRUDGING EAST ACROSS THE BLUE RIDGE
MOUNTAINS AND FOOTHILLS NORTH OF LYNCHBURG VA...WITH ISOLATED
SHOWERS AND STORMS STARTING TO FADE FROM NE TN INTO THE FOOTHILLS
OF NORTH CAROLINA.
KEPT HIGHER POPS SITUATED ACROSS THE NORTHEAST PIEDMONT OF
BUCKINGHAM SOUTH TO SOUTHSIDE VA AND THEN WEST TOWARD WILKES
COUNTY NC THIS EVENING WITH DRIER WX IN THE NORTHWEST.
18Z NAM/GFS...12Z ECMWF AND THE LATEST HRRR SHOWING OVERALL
AGREEMENT IN BRING A CLUSTER OF SHOWERS/STORMS ACROSS THE
SOUTHEAST CWA AROUND 03Z AS THE UPPER SHORTWAVE MOVES EAST OF OUT
TN. BUMPED POPS UP SOME HERE AND MAY NEED TO GO EVEN HIGHER IF
THIS HAPPENS. BIG CONSIDERATION IS INSTABILITY WEAKENING AS SUN
SETS BUT GIVEN HOW WARM IT IS OUT THERE NOW AND ADDING SOME UPPER
LIFT...THINKING IS CONVECTION SHOULD MAINTAIN ITSELF ACROSS THE
NORTH CAROLINA FOOTHILLS PIEDMONT AND NWD TOWARD SOUTHSIDE VA INTO
THE OVERNIGHT HOURS...WITH THE LIGHTNING SIDE OF THINGS SUBSIDING
OVERNIGHT.
PREVIOUS VALID DISCUSSION...
THE FRONT IS EXPECTED TO HAVE MOVED SOUTH THROUGH MOST...IF NOT
ALL...OF THE REGION BY MIDNIGHT. BEHIND THE FRONT...SURFACE AND
LOW LEVELS WINDS ARE PROGGED TO VEER NORTHEAST TO ALMOST EAST IN
SOME AREAS. THIS WILL HAVE THE IMPACT OF KEEPING LINGERING
MOISTURE IN THE BOUNDARY LAYER PINNED UP AGAINST THE CREST OF THE
BLUE RIDGE. WE ARE EXPECTING STRATUS CLOUDS TO DEVELOP OVERNIGHT
AND LOWER AS THE NIGHT PROGRESSES. THIS MAY ALSO HELP YIELD SOME
DRIZZLE IN THE CREST OF THE BLUE RIDGE. PATCHY OR AREAS OF FOG ARE
ALSO EXPECTED ALONG AND NEAR THE PORTION OF THE BLUE RIDGE
SOUTHWEST OF ROANOKE. THE PROXIMITY OF THE FRONT WILL ALSO HELP
MAINTAIN SOME SHOWERS ACROSS THE SOUTHEAST PART OF THE REGION. LOW
TEMPERATURES TONIGHT WILL BE AROUND 5 TO 8 DEGREES COOLER THAN
TEMPERATURES REALIZED THIS MORNING THANKS TO LOWERING DEW POINTS
BEHIND THE FRONT.
ON THURSDAY...CLOUD COVER WILL BE SLOW TO ERODE...ESPECIALLY ALONG
AND EAST OF THE BLUE RIDGE SOUTHWEST OF ROANOKE. THIS REGION WILL BE
CLOSEST TO THE DEPARTING COLD FRONT AS IT DEVELOPS A SMALL BUCKLE IN
IT WITH THE PASSAGE OF THE PARENT UPPER TROUGH. ALSO...SURFACE
AND LOW LEVEL WINDS WILL HAVE A GREATER EASTERLY COMPONENT. THIS
POINTS TOWARDS THE AREA KEEPING THE CLOUDS LONGER WITH ISOLATED TO
SCATTERED SHOWERS AND A FEW STORMS. HIGHS TOMORROW WILL BE SIMILAR
OR ONLY SLIGHTLY COOLER THAN TEMPERATURES OF TODAY ACROSS THE
MOUNTAINS. OVER THE PIEDMONT...HIGHS WILL BE AROUND 10 DEGREES
COOLER THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
THE SHORT TERM WILL BE DOMINATED BY A BROAD EASTERN U.S.
TROUGH...CONTINUALLY REINFORCED BY UPSTREAM SHORT WAVES. AT THE
BEGINNING OF THE SHORT TERM...THE TROUGH AXIS ATTEMPTS TO SHIFT EAST
OF THE AREA AS A COASTAL LOW MOVES UP AND JUST OFF THE MID-ATLANTIC
COAST. HOWEVER...A STRONG UPSTREAM SHORT WAVE MOVING SOUTHEAST OUT
OF ALBERTA...WILL SHIFT THE TROUGH AXIS BACK INTO THE OHIO VALLEY BY
SATURDAY. WITH SUBSIDENCE EXPECTED BEHIND THE DEPARTING COASTAL LOW
AND NOTABLY DRY AIR...DEW POINTS IN THE 50S/LOW 60S...ADVECTING INTO
THE NW HALF OF THE CWA...HAVE CONFINED SLIGHT CHC POPS TO THE FAR
SOUTHEAST AND POTENTIAL EASTERLY FLOW UPSLOPE AREAS IN THE NW NC
MOUNTAINS AT THE BEGINNING. UPSLOPE EASTERLY FLOW WILL INCREASE
SATURDAY ALONG THE ALLEGHANYS AND BLUE RIDGE OF NW NC...SO HAVE
CONTINUED TO INCREASE POPS IN THE WESTERN AREAS AS A RESULT FOR FRI
AFTERNOON. BY SATURDAY...OUR ATTENTION TURNS TO THE UPSTREAM DIGGING
TROUGH...WHICH SHOULD BE THE NEXT WIDESPREAD PCPN EVENT FOR OUR CWA.
TOO FAR OUT TO BE CONCERNED ABOUT RAINFALL AMOUNTS...BUT THIS WOULD
BE THE NEXT TIME FRAME FOR ANY SIGNIFICANT SEVERE OR FLASH FLOOD
THREAT. HAVE GONE AHEAD AND ADVERTISED LIKELY POPS FOR SAT
AFTERNOON/EVENING IN THE WEST.
SOMEWHAT COOLER MIN TEMPS WILL BE NOTED AT THE
BEGINNING...ESPECIALLY IN THE WEST WITH DEWPOINTS DROPPING INTO THE
50S ACROSS THE ALLEGHANYS. LOWS SHOULD BE IN THE MID TO UPPER 50S IN
THE HIGHER ELEVATIONS ACROSS SW VA/NW NC/SE WV. BY SATURDAY...WITH
SW FLOW RETURNING AND INCREASING MOISTURE...MIN TEMPERATURES WILL
CREEP CLOSER TO NORMAL. MAX TEMPS SHOULD AVERAGE JUST BELOW NORMAL
THROUGH THE PERIOD. OVERALL...CONTINUED BELOW NORMAL AS MOST OF THIS
SUMMER HAS BEEN SO FAR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 730 PM EDT WEDNESDAY...
GOING TO HAVE TO WATCH CONVECTION INTO OVERNIGHT AS MODELS SHOWING
BETTER CONCENTRATION AFFECTING THE DANVILLE AREA. WILL HOLD OFF
ADDING PREDOMINANT SHOWERS HERE BUT WILL HAVE VCSH AT 03Z TIL 05Z.
AMENDMENTS WILL OCCUR IF SOMETHING LOOKS TO BE HEADING THAT WAY.
THE WIND FLOW OVERNIGHT WILL BE WEAK AND VARY FROM THE NORTHWEST
TO THE NORTHEAST. MODELS ATTEMPTING TO SHOW EITHER A FOG OR
STRATUS SCENARIO AS THE LOW LVL WINDS TURN MORE TOWARD THE
NORTHEAST.
THINKING THAT FOG WILL BE MORE PROBLEMATIC IN THE MOUNTAINS WITH
SOME STRATUS FORMING ALONG AND WEST OF THE BLUE RIDGE BRINGING
CIGS TO MVFR...WITH POSSIBLE IFR/LIFR AT LWB/BLF/BCB. THINK THE
PIEDMONT CLOUDS UP AS WELL BUT CIGS HERE SHOULD STAY VFR OR MAYBE
HIGH END MVFR. WILL HAVE TO WATCH LYH FOR POTENTIAL FOG GIVEN THE
SHOWERS NEARBY THIS EVENING.
FOR THURSDAY...THE FLOW REMAINS OUT OF THE NORTHEAST TO AT TIME
EAST...SO CIGS MAY LINGER THROUGH THIS PERIOD...WITH VFR EXPECTED
AFTER 14-16Z. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH OF ROANOKE BUT CANNOT RULE OUT BCB/ROA AND MAYBE EVEN BLF
SEEING SHOWERS OR STORMS NEARBY.
THURSDAY EVENING...THE AXIS OF THE UPPER TROUGH PASSES OVERHEAD.
EVEN THOUGH DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN
ISSUE AT BCB/LWB GIVEN WET SOILS AND LIGHT WIND.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...DS/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1006 PM CDT WED JUL 24 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK HIGH
PRESSURE STRETCHING FROM THE CENTRAL GREAT PLAINS TO THE CENTRAL
GREAT LAKES THIS AFTERNOON. THE WESTERN GREAT LAKES IS FIRMLY
ENTRENCHED WITHIN NORTHWEST FLOW ALOFT...AND SEVERAL WEAK SHORTWAVES
ARE COMBINING WITH DIURNAL INSTABILITY TO GENERATE A WIDESPREAD DIURNAL
CU FIELD. THIS CU IS MOST BUBBLY OVER NORTHERN WISCONSIN AND THE
UPPER PENINSULA WHERE THERE ARE A FEW SPECKS ON RADAR INDICATING A
FEW LIGHT SHOWERS. LOOKING UPSTREAM...SOME BREAKS IN THE CLOUD
COVER OVER NORTHERN MINNESOTA. A SHORTWAVE OVER LAKE WINNIPEG IS
PRODUCING SOME THUNDERSTORMS...BUT THAT SHOULD REMAIN NORTH OF THE
REGION TONIGHT. THEN THERE IS THE NEXT SIGNIFICANT SYSTEM WHICH IS
DIVING SOUTH OVER SASKATCHEWAN AND WILL IMPACT OUR AREA TOMORROW.
CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS TONIGHT...FOLLOWED
BY LOW SEVERE WEATHER CHANCES TOMORROW.
TONIGHT...ISOLATED SHOWERS WILL DIMINISH EARLY THIS EVENING WITH LOSS OF
DAYTIME HEATING. HOWEVER...WEAK MID-LEVEL WARM ADVECTION WILL
CONTINUE FOR MUCH OF THE NIGHT SO HARD TO GET A HANDLE ON SKY
CONDITIONS. SATELLITE SEEMS TO SUGGEST THAT AREAS OF MID-LEVEL
CLOUDS WILL LINGER THIS EVENING...AND THEN SOME CLEARING WILL WORK
OVERHEAD UNTIL THE NEXT SYSTEM ARRIVES THURSDAY MORNING. WILL DROP
CLOUD COVERAGE DURING THE OVERNIGHT PERIOD. MORE CLOUDS/MOISTURE
WILL KEEP TEMPS IN THE LOW TO MID 50S.
THURSDAY...A STRONG SHORTWAVE WILL MOVE ACROSS LAKE WINNIPEG AND
INTO SOUTHWEST ONTARIO. IT WILL PUSH A WEAK FRONT FROM NE MINNESOTA
TO NORTHWEST WISCONSIN OVER THE COURSE OF THE DAY. STRENGTHENING
SOUTHWEST FLOW AHEAD OF THE FRONT WILL BRING IN INCREASING AMOUNTS
OF MOISTURE...AS MODELS SHOW PWATS INCREASING TO AROUND 1.5 INCHES
FROM ABOUT AN INCH AT THE START OF THE DAY. WARM ADVECTION TO
OCCUR THROUGH THE DAY IS NOT ALL THAT STRONG...BUT WITH AMPLE
MOISTURE AND ML CAPES INCREASING TO 900-1400 J/KG IN THE
AFTERNOON...CAN ENVISION STORMS INITIATING LATE IN THE MORNING OR
EARLY AFTERNOON AND THEN BUILDING DURING THE AFTERNOON. IF ANY KIND
OF MORNING CLOUD COVER DOES NOT HOLD BACK HEATING...30-35KTS OF
0-6KM BULK SHEAR WOULD SUPPORT AN ISOLATED SEVERE THREAT. FORCING
IS ON THE WEAKER SIDE...SO DO NOT THINK ANY SORT OF WIDESPREAD
OUTBREAK IS POSSIBLE...BUT A SCATTERED COVERAGE OF STORMS ALONG WITH
AN ISOLATED SEVERE THREAT SEEMS REASONABLE. STORMS SHOULD ALSO BE
RATHER PULSIE IN NATURE. HIGHS RETURNING TO THE MID AND UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
THE SERVER CRASHED RIGHT AS WE WERE GOING TO ISSUE THE AFD AND LOST
THIS PART OF THE DISCUSSION. SINCE THE LONG TERM FORECAST HAD TO
LEAVE AT 3PM...WILL HAVE TO MAKE THIS SHORT AND SWEET.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...CONVECTION ALONG AND AHEAD OF
THE COLD FRONT WILL BE ONGOING THURSDAY NIGHT. DETAILS START TO GET
MORE MURKY BY THIS POINT...BUT FORCING IMPROVES THURSDAY NIGHT AS A
LOBE OF THE STRONG SHORTWAVE OVER ONTARIO DROPS SOUTHEAST INTO
WESTERN LAKE SUPERIOR. ELEVATED CAPE WILL BE DIMINISHING THROUGH
THE NIGHT DESPITE FORCING IMPROVING AND PWATS AROUND 1.5 INCHES.
MODELS HAVE DIFFERENT SCENARIOS PLAYING OUT THURSDAY NIGHT...WITH
SOME GUIDANCE HINTING AT AN MCS MOVING OVER CENTRAL WISCONSIN AND
THE FOX VALLEY. THE FRONT WILL FINISH CROSSING THE REGION FRIDAY
MORNING AND MUCH COLDER AIR WILL FILTER IN BEHIND THE FRONT. SOME
SHOWERS AND THUNDERSTORMS LOOK LIKELY AHEAD OF THE FRONT...AND THEN
SCATTERED SHOWERS SHOULD LINGER THROUGH DAY BEHIND THE FRONT WITH
THE SHORTWAVE OVERHEAD. WITH CLOUDY AND SHOWERY WEATHER...TEMPS
WILL STRUGGLE TO REACH THE MID 60S NORTH TO MID 70S SOUTH...AND
COULD BE LOOKING AT MORNING HIGHS. REMAINING CLOUDY FRIDAY NIGHT THOUGH
SHOWERS SHOULD BE DIMINISHING. BREEZY AND COOL WITH LOWS IN THE 40S
TO LOW 50S.
REST OF THE FORECAST....CONTINUED CLOUDY AND COOL ON SATURDAY WITH A
FEW SHOWERS POSSIBLE COMING OFF LAKE SUPERIOR INTO NORTHERN
WISCONSIN. DROPPED HIGHS SEVERAL DEGREES DUE TO CLOUD COVER AND
925MB TEMPS IN THE UPPER SINGLE DIGITS. CLOUDS AND SHOWERS POSSIBLY
TO HANG AROUND INTO SUNDAY BEFORE THE UPPER LOW FINALLY DEPARTS.
HIGH PRESSURE WILL BE OVER THE AREA ON MONDAY WHEN TEMPS MODERATE
SOME. THEN THE NEXT CHANCE OF RAIN ARRIVES TUESDAY INTO WEDNESDAY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 938 PM CDT WED JUL 24 2013
VFR CONDITIONS TO PREVAIL OVERNIGHT. THE CHANCE FOR
SHOWER AND STORMS INCREASES THURSDAY MORNING OVER NORTHWEST
WISCONSIN AS A COLD FRONT DROPS INTO THE NORTHERN GREAT LAKES
REGION. SHOWERS AND STORMS WILL CONTINUE TO INCREASE IN COVERAGE
LATER THURSDAY INTO THURSDAY NIGHT AS THE FRONTAL SYSTEM DROPS
SOUTH AND AN UPPER DISTURBANCE BUILDS INTO THE GREAT LAKES REGION.
VFR CONDITIONS WITH SCATTERED MVFR CIGS DUE TO SCATTERED
CONVECTION WILL SLOWLY DROP SOUTHWARD ON THURSDAY. MORE WIDESPREAD
RAIN WITH EMBEDDED STORMS WILL BECOME MORE WIDESPREAD THURSDAY
NIGHT AND AS A RESULT IFR/MVFR CIGS AND MVFR VSBYS TO BECOME MORE
DOMINATE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......MPC
AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 224 PM CDT TUE JUL 23 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW YESTERDAYS COLD
FRONT HEADED FOR THE OHIO VALLEY WHILE CANADIAN HIGH PRESSURE IS
MOVING SOUTHEAST OVER THE NORTHERN PLAINS. COLD ADVECTION IS
OCCURRING BEHIND THE FRONT OVER THE WESTERN GREAT LAKES AND THE
THERMAL TROUGHING IS CONTRIBUTING TO A WIDESPREAD STRATO-CU FIELD
ACROSS MOST OF THE STATE. LOOKING UPSTREAM...A FEW SHORTWAVES NOTED
OVER SASKATCHEWAN AND CENTRAL MANITOBA...WHERE CU LOOKS RATHER
BUBBLY BUT NO LIGHTNING STRIKES SO FAR THIS AFTERNOON. AS HIGH
PRESSURE BUILDS INTO THE REGION TONIGHT...CLOUDS AND TEMPS WILL BE
THE MAIN FORECAST CONCERNS FOLLOWED BY SHOWER CHANCES TOMORROW.
TONIGHT...HIGH PRESSURE WILL SHIFT SOUTHEAST TOWARDS WESTERN GREAT
LAKES. GUSTY NORTH WINDS WILL PERSIST ALONG THE LAKE SHORE LONGER
THAN NORTH-CENTRAL WISCONSIN...BUT SHOULD ALSO DIMINISH LATE IN THE
NIGHT. AS WINDS DROP OFF...GOOD RADIATIONAL COOLING CONDITIONS WILL
SETUP...THOUGH PATCHES OF MID-CLOUDS MAY ARRIVE AFTER LATE IN THE
EVENING OR AFTER MIDNIGHT. THE COLD SPOTS COULD REACH THE LOWER
40S...WHILE MOST AREAS WILL RANGE FROM THE MID 40S TO LOW 50S.
PATCHY FOG WILL ALSO BE POSSIBLE LATE TONIGHT AS WELL.
WEDNESDAY...HIGH PRESSURE WILL REMAIN ACROSS THE AREA. WEAK
SHORTWAVES WILL BE DIVING TOWARDS WISCONSIN WITHIN NORTHWEST FLOW
ALOFT. CONVECTIVE TEMPS ARE PRETTY LOW TOMORROW...IN THE UPPER 60S
TO LOWER 70S. COMBINED WITH WEAK FORCING ALOFT...THAT SHOULD BE
ENOUGH TO PRODUCE A GOOD CU FIELD BY LATE MORNING. PROGGED
INSTABILITY TOMORROW AFTERNOON WILL BE AROUND 100 J/KG...BUT THERE
IS A SIZABLE CAP AROUND 625MB THAT WILL BE TOUGH TO OVERCOME.
STILL...CU SHOULD BE DEEP ENOUGH FOR A WIDELY SCT TO LOW END SCT OF
SHOWERS OVER THE HIGHER TERRAIN OF N-C WISCONSIN. PERHAPS AN
ISOLATED RUMBLE OF THUNDER IS POSSIBLE. HIGHS WILL BE RATHER
UNIFORM IN THE LOW TO MID 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 224 PM CDT TUE JUL 23 2013
UPPER AIR PATTERN CHARACTERIZED BY WESTERN RIDGE AND GREAT LAKES
TROF WILL DOMINATE THE WEATHER PATTERN DURING THE PERIOD.
SHORTWAVE TROFS WILL AMPLIFY MEAN TROF OVER GREAT LAKES LATER THIS
WEEK INTO WEEKEND. CLOSED LOW FORECAST TO DEVELOP WHICH WILL KEEP
COOL AIR IN PLACE INTO EARLY NEXT WEEK.
BEST CHANCE FOR RAIN WILL BE LATE THURSDAY INTO FRIDAY AS
STRONGEST OF THE SHORTWAVE TROFS MOVE ACROSS AREA. SURFACE LOW
PRESSURE AND COLD FRONT WILL PUSH ACROSS AREA WITH CONVECTION
EXPECTED GIVEN INSTABILITY AND SHEAR.
WARM AIR ADVECTION AHEAD OF APPROACHING SYSTEM COULD PUSH PRECIP
INTO AREA AS EARLY AS LATE WEDNESDAY NIGHT/EARLY THURSDAY.
TEMPS DURING MUCH OF PERIOD WILL REMAIN BELOW NORMAL. ON
SATURDAY...HIGHS ONLY IN THE 60S ACROSS MUCH OF AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1237 PM CDT TUE JUL 23 2013
COLD AIR FLOWING SOUTH OFF LAKE SUPERIOR IS CONTRIBUTING
TO A WIDESPREAD STRATO-CU FIELD ACROSS MUCH OF THE STATE. CIGS HAVE
BEEN RISING WITH DAYTIME HEATING SO SHOULD REMAIN VFR THIS
AFTERNOON. CLOUDS ARE RELATIVELY SHALLOW AND THEIR IS AMPLE DRY AIR
ALOFT...WHICH SHOULD MIX DOWN AND HELP DISSIPATE THE CLOUDS AROUND
MID-AFTERNOON. NORTH WINDS WILL ALSO REMAIN GUSTY THROUGH LATE
AFTERNOON BEFORE DIMINISHING WITH THE APPROACH OF HIGH PRESSURE
TONIGHT. MAINLY CLEAR SKIES TONIGHT WITH SOME PATCHY MID-LEVEL
CLOUDS ARRIVING LATE FROM THE WEST. CLOUDS TO BUILD DURING THE LATE
MORNING TOMORROW WHICH COULD LEAD TO WIDELY SCT SHOWERS OVER
NORTHERN WISCONSIN TOMORROW AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
346 PM MDT TUE JUL 23 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013
AN INFLUX OF MONSOONAL MOISTURE WILL INDICATE A TURN TO A MUCH MORE
CLIMATOLOGICALLY NORMAL PERIOD OF UNSETTLED WEATHER BEGINNING
WEDNESDAY AND CONTINUING THROUGH MUCH OF THE LONGER TERM. BEFORE
THEN...AFTERNOON SATELLITE PIX SHOW SHALLOW CONVECTION BEGINNING TO
DEVELOP OVER THE NORTHERN LARAMIE RANGE. A RESULT OF LLVL
CONVERGENCE DUE TO A STATIONARY BOUNDARY DRAPED UP ALONG THE FRONT
RANGE. DEW POINTS WEST OF THIS BOUNDARY WERE BELOW 30F...WITH
RAWLINS REPORTING 11F. MORE AMPLE LLVL MOISTURE EAST OF THIS
BOUNDARY AS INDICATED BY 50 DEGREE DEW POINTS. IN FACT...THIS
BOUNDARY PUSHED EAST OF KCYS EARLY THIS MORNING DROPPING DEWPOINTS
BRIEFLY BACK INTO THE 20S. MOST OF THE CWA WILL REMAIN DRY THIS
EVENING...THESE EXCEPTION BEING THE FAR EASTERN ROW OF COUNTIES FROM
CHADRON TO BRIDGEPORT. AS HAS BEEN THE CASE THE PAST SEVERAL
DAYS...12Z MODEL OUTPUT CONTINUES TO SUGGEST CAP WILL HOLD AND THE
AREA WILL REMAIN DRY. EVEN THE LATEST HRRR DEVELOPS CONVECTION JUST
EAST OF THE CWFA. PERSISTENCE SAYS OTHERWISE HOWEVER...SO WILL KEEP
SLIGHT CHANCES GOING FROM CHADRON AND BRIDGEPORT. IF THE CAP DOES
MANAGE TO BREAK...SBCAPES OF 1000 TO 1500 J/KG WOULD BE REALIZED
WHICH COULD RESULT IN SOME SEVERE DEVELOPMENT. ANY THUNDERSTORMS
WILL WIND DOWN BY LATE EVENING.
ATTENTION THEN SHIFTS TO UPSTREAM MOISTURE AND SHORTWAVE EVIDENT ON
WV IMAGERY FROM NRN CA/SRN OR EAST INTO UTAH. THIS SUB-TROPICAL
MONSOON MOISTURE PLUME AND SHORTWAVE WILL SLOWLY MEANDER NORTH INTO
THE REGION ON WEDNESDAY. 12Z MODELS HAVE DELAYED ITS ARRIVAL BY A
FEW HOURS. ALTHOUGH THERE IS SOME POTENTIAL FOR DRY LIGHTNING EARLY
WEDNESDAY...AM NOT CONFIDENT ON ITS COVERAGE. SO FOR NOW...HAVE
MAINTAINED THE INHERITED COVERAGE...BUT HAVE CONFINED IT TO THE
SNOWY/SIERRA MADRE RANGES WEDNESDAY MORNING. BY MIDDAY
WEDNESDAY...CONVECTION WILL BE DEVELOPING OVER THE SE WYOMING
MOUNTAINS AND ADJACENT FOOTHILLS/VALLEY LOCATIONS. PROGD SBCAPES
WILL NOT BE PARTICULARLY HIGH (500-800 J/KG). HOWEVER PWATS RISING
ABOVE AN INCH ALONG WITH STORM MOTIONS OF 10 KNOTS OR LESS WILL
RESULT IN EFFICIENT RAIN PRODUCERS. CAN NOT RULE OUT THE POTENTIAL
FOR SMALL HAIL TOO...THOUGH THERMODYNAMIC PARAMETERS ARE NOT
FAVORABLE. SHORTWAVE WILL MEANDER ATOP THE CWA WEDNESDAY NIGHT WHICH
SHOULD AID IN THE CONTINUATION OF NOCTURNAL CONVECTION.
MID/UPPER-LEVEL FLOW WILL TURN NORTHWEST FOR THURSDAY BEHIND
DEPARTING SHORTWAVE. AT THE SFC...A WEAK COOL FRONT ALONG WITH
FAVORABLE UPSLOPE BEHIND FROPA WILL SET THE STAGE FOR ANOTHER ROUND
OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS. AGAIN AMPLE MOISTURE
WILL ACT TO LIMIT SEVERE POTENTIAL...ONLY YIELDING SBCAPES OF
500-800 J/KG. STORM MOTIONS WILL AGAIN BE LESS THAN 10 KNOTS.
THE THICKER CLOUD CANOPY ALONG WITH WEAK COLD FROPA ON THURSDAY WILL
CAUSE TEMPERATURES TO COOL FROM THE UPPER 80S ON WEDNESDAY INTO THE
LOWER 80S ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013
MONSOONAL MOISTURE WILL CONTINUE TO STREAM INTO THE REGION ON
FRIDAY THROUGH THE WEEKEND. SHORTWAVE MOVES SOUTHWARD ACROSS THE
NORTHERN HIGH PLAINS ON THURSDAY NIGHT WITH RISING SFC PRESSURES
BEHIND IT OVER THE PLAINS. THIS RESULTS IN GOOD SOUTHEAST UPSLOPE
BY FRIDAY WITH PW VALUES OF 1.00-1.25 INCHES OVER MOST AREAS ALONG
AND EAST OF THE LARAMIE RANGE. WIDESPREAD QPF IS DEPICTED ON BOTH
THE GFS AND ECMWF BY FRIDAY AFTN/EVENING. WITH DEEP LAYER SHEAR OF
50 KTS AND CAPE VALUES OF 1250-1500 J/KG...A FEW STRONG TO SEVERE
STORMS COULD BE POSSIBLE OVER THE PLAINS. THE STEERING FLOW IS A
LITTLE TOO FAST FOR MAJOR FLASH FLOODING CONCERNS ON FRIDAY. UPPER
LEVEL RIDGE AXIS IS POSITIONED OVER WESTERN WY BY SATURDAY
AFTN...WITH NORTHWESTERLY MIDLEVEL FLOW PERSISTING IN THE CWA.
CONVECTIVE PARAMETERS APPEAR VERY SIMILAR TO FRIDAY...SO GENERALLY
CARRIED THE SAME POPS. RIDGE AXIS IS ALMOST DIRECTLY OVER THE CWA
BY SUNDAY WITH STEERING FLOW BECOMING MORE WESTERLY AND SOMEWHAT
SLOWER THAN THE PREVIOUS DAYS. SHORTWAVE ROTATES THROUGH THE AREA
DURING PEAK HEATING AND WITH PW VALUES REMAINING ABOVE
NORMAL...EXPECT ANOTHER DAY OF GOOD STORM COVERAGE. DRIER
700-500MB FLOW CREEPS INTO THE REGION BY MONDAY WHICH COULD RESULT
IN MORE ISOLATED TSTM CHANCES. TEMPS THROUGHOUT THE PERIOD WILL BE
SLIGHTLY BELOW AVERAGE WITH THE MOIST AIRMASS AND RATHER CLOUDY
CONDITIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1146 AM MDT TUE JUL 23 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. CUMULUS WILL
LIKELY DEVELOP ACROSS THE PLAINS DURING THE AFTERNOON. ISOLATED
SHOWERS AND TSTMS WILL BE POSSIBLE MAINLY OVER THE NORTHERN
NEBRASKA PANHANDLE...SO INCLUDED VCTS AT KCDR DURING THE EVENING.
WINDS WILL GENERALLY BE BELOW 10-15 KTS.
&&
.FIRE WEATHER...
ISSUED AT 330 PM MDT TUE JUL 23 2013
MONSOONAL MOISTURE WILL RETURN TO THE DISTRICT IN EARNEST DURING THE
DAY ON WEDNESDAY. AS THIS OCCURS...WE MAY BE ABLE TO SEE SOME
HIGH-BASED SHOWER/THUNDERSTORM DEVELOPMENT MAINLY OVER THE SNOWY AND
SIERRA MADRE RANGES. AM NOT CONFIDENT OF WHETHER OR NOT THIS WILL
OCCUR...BUT IF IT DOES THE BEST TIME WILL BE BETWEEN 6AM AND NOON
WEDNESDAY. AFTER THAT...BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL RETURN TO THE DISTRICT BEGINNING WEDNESDAY AFTERNOON AND
CONTINUING INTO THE UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...FINCH
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
335 AM MDT THU JUL 25 2013
.SHORT TERM...A DISTURBANCE IS CURRENTLY OVER THE MTNS EARLY THIS
MORNING AND SHOULD EXIT NERN COLORADO BY LATE MORNING. AS THIS
FEATURE MOVES ACROSS THERE WILL BE A FEW SHOWERS AND POSSIBLY A
TSTM THRU THE MORNING HOURS.
FOR THIS AFTN QUITE A BIT OF SUBTROPICAL MOISTURE WILL REMAIN OVER
THE AREA WITH PRECIPITABLE WATER VALUES AROUND AN INCH. WOULD
EXPECT TSTMS TO REDEVELOP OVER THE HIGHER TERRAIN BY EARLY AFTN.
MEANWHILE OVER NERN CO A COOL FNT WILL BE NR THE WYOMING BORDER
AROUND 18Z AND THEN MOVE ACROSS THE PLAINS THRU THE AFTN. NOT SURE
HOW THINGS ARE GOING TO EVOLVE WITH THIS FNT AS FAR AS TSTM
DEVELOPMENT GOES OVER THE PLAINS. ITS POSSIBLY ACTIVITY COULD END
UP FOCUSING CLOSER TO THE FOOTHILLS AND OVER THE PALMER DIVIDE
WITH LIMITED ACTIVITY OVER THE PLAINS THRU THE AFTN. SHORT RANGE
MODELS ARE NOT MUCH HELP AS FAR AS DEFINING BEST AREAS FOR TSTMS
SO WILL JUST KEEP POPS IN THE CHC CATEGORY. OVERALL INSTABILITY
DOES NOT LOOK AS UNSTABLE AS WED WITH THE MID LVL FLOW SOMEWHAT
WEAKER SO SVR THREAT LOOKS LOW. STORMS WILL BE SLOWER MOVING WHICH
COULD LEAD TO HEAVY RAINFALL IN SOME AREAS. AS FAR AS TEMPS WILL
KEEP HIGHS MAINLY IN THE LOWER TO MID 80S OVER NERN CO.
FOR TONIGHT WITH THE FLOW OF SUBTROPICAL MOISTURE CONTINUING IN
THE MTNS SHOWERS AND A FEW STORMS COULD LINGER OVERNIGHT SO WILL
KEEP IN SOME LOW POPS. OVER NERN CO IT APPEARS TSTM ACTIVITY
SHOULD GRADUALLY END IN THE EARLY EVENING HOURS.
.LONG TERM...THE NEXT WEEK CONTINUES TO LOOK ACTIVE AND WET ACROSS
THE FORECAST AREA. AN ELONGATED UPPER LEVEL HIGH PRESSURE RIDGE
WILL EXTEND ACROSS THE SOUTHERN TIER OF THE COUNTRY WITH MONSOONAL
MOISTURE ADVECTING ACROSS ARIZONA AND NEW MEXICO INTO UTAH AND
COLORADO. DAILY PRECIPITATION DISTRIBUTIONS ARE GOING TO DEPEND ON
MESOSCALE FEATURES LIKE STRENGTH OF UPSLOPE FLOW AND THE PRESENCE
OF A DENVER CYCLONE...AS WELL AS THE LOCATION OF PASSING WEAK
UPPER LEVEL JET STREAMS. THE LATEST RUN OF THE ECMWF POINTS TOWARD
SUNDAY AFTERNOON BEING A PARTICULARLY ACTIVE DAY WITH DECENT
SOUTHEASTERLY LOW LEVEL FLOW ACROSS EASTERN COLORADO AND WEAK
WESTERLY FLOW ALOFT. THE FEED OF SUB-TROPICAL MOISTURE LOOKS LIKE
IT WILL REMAIN IN PLACE THROUGH AT LEAST NEXT TUESDAY...SO THE
FORECAST WILL CONTINUE TO MENTION THE CHANCE OF THUNDERSTORMS EACH
DAY. ALONG WITH THE PERSISTENT CHANCES OF PRECIPITATION...
TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL BUT STILL
WARM ENOUGH TO PRODUCE THE INSTABILITY NECESSARY FOR DAILY
CONVECTION TO DEVELOP. PERIODS OF NOCTURNAL SHOWERS CAN ALSO NOT
BE RULED OUT LIKE WE ARE SEEING THIS MORNING.
&&
.AVIATION...MAY SEE A FEW -SHRA THIS MORNING AS DISTURBANCE MOVES
ACROSS BUT CEILINGS SHOULD STAY ABV 8000 FT. DO NOT HAVE A GOOD
FEEL FOR WINDS THIS MORNING HOWEVER WILL KEEP WINDS LIGHT NWLY
THRU MID MORNING AND THEN HAVE THEM BECOME MORE NNE BY EARLY AFTN
AS A FNT MOVES ACROSS. THE LATEST HRRR AND RAP INDICATES THERE
WOULD A CHC OF TSTMS IN THE 21Z-00Z TIME PERIOD SO WILL PUT IN A
PROP GROUP FOR -TSRA. FOR THIS EVENING TSTM THREAT SHOULD END BY
01Z WITH WINDS BECOMING DRAINAGE BY MIDNIGHT.
&&
.HYDROLOGY...THERE WILL BE SCATTERED THUNDERSTORMS THIS AFTERNOON
WITH SOME LOCALLY HEAVY RAIN POSSIBLE. THE STRONGER STORMS COULD
PRODUCE RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES WHICH COULD
LEAD TO SOME FLOODING ISSUES IF THEY TRACK ACROSS THE BURN SCARS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
AVIATION...RPK
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
443 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW
FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL
CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND
SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE
NORTHEAST FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
440 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO
THE CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS
INTO THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE THEREAFTER...BUILDING
IN FROM THE WEST. THIS WILL EVENTUALLY WEAKEN BY MID NEXT
WEEK...WITH WEAK LOW PRESSURE BEGINNING TO APPROACH FROM THE SOUTH.
.LONG TERM...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW FOR
A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL CLOSED
LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND SUNDAY NIGHT.
THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND FLATTEN WITH WITH LESS
AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST FOR EARLY TO MID NEXT
WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
439 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ORGANIZED AREA OF SHRA/TSTMS OFF THE NJ COAST HAS WEAKENED
CONSIDERABLY OVERNIGHT AND ANY ACTIVITY LOOKS TO PASS JUST E OF
THE AREA. A BIT FURTHER E...SCT SHOWERS HAVE DEVELOPED JUST S OF
LONG ISLAND AND OVER LONG ISLAND SOUND. THERE WILL BE ISOLD
SHOWERS THIS MORNING OVER EASTERN LONG ISLAND AND CT FROM THIS
ACTIVITY.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO
THE CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS
INTO THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE THEREAFTER...BUILDING
IN FROM THE WEST. THIS WILL EVENTUALLY WEAKEN BY MID NEXT
WEEK...WITH WEAK LOW PRESSURE BEGINNING TO APPROACH FROM THE SOUTH.
.LONG TERM...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW FOR
A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL CLOSED
LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND SUNDAY NIGHT.
THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND FLATTEN WITH WITH LESS
AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST FOR EARLY TO MID NEXT
WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
VFR EARLY THIS MORNING...THOUGH WILL SEE CEILINGS AROUND 3500-5000
FT. MVFR IS EXPECTED TO DEVELOP LATE MORNING/EARLY AFTERNOON FOR
EASTERN CT/LONG ISLAND TERMINALS...THEN MID TO LATE AFTERNOON FOR
CITY TERMINALS. SPOTTY SHOWERS MAY DEVELOP AT ANY TIME THIS
MORNING...WITH A BETTER CHANCE FOR SHOWERS DURING THE AFTERNOON
FOR EASTERN CT/LONG ISLAND TERMINALS. NOT SURE HOW FAR WEST THE AREA
OF SHOWERS WILL EXTEND...WHICH WILL HAVE AN IMPACT ON NYC TERMINALS.
WINDS MAINLY OUT OF THE NNE-NE 8-13KT WITH GUSTS UP TO 20 KT MOST
TERMINALS. WINDS BECOME NE THROUGHOUT MID-LATE MORNING WITH
GUSTS UP TO 20 KT CONTINUING THROUGH THE DAY.
THESE WINDS BACK TO THE N SOMETIME THIS EVENING.
...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: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS...IF
ANY...AND CEILINGS LOWERING TO MVFR.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN TIMING OF SHOWERS AND WHEN
CEILINGS LOWER TO MVFR.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...MAINLY VFR. MVFR POSSIBLE IN ANY -RA...BEST CHANCE AT
COASTAL/EASTERN TERMINALS.
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
325 AM EDT THU JUL 25 2013
...UPDATED FOR RIP CURRENT STATEMENT AT BOTTOM OF DISCUSSION...
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN UPPER LEVEL
PATTERN OVER THE CONUS DOMINATED BY LARGE SCALE RIDGING OVER THE
WESTERN STATES AND DOWNSTREAM TROUGHING TO THE EAST OF THE MS
VALLEY. OUR FORECAST AREA RESIDES WITHIN A REGION OF DEEP WEST TO
NORTHWEST FLOW TOWARD THE SOUTHERN PERIPHERY OF THIS EASTERN U.S.
TROUGH. OCCASIONAL WEAK IMPULSES CONTINUE TO RIDE THIS FLOW DOWN
INTO THE SOUTHEASTERN STATES AND ENHANCE ROUNDS OF SCT CONVECTION
OFF THE NORTHEAST GULF OF MEXICO. ONE ROUND OF LATE EVENING SHOWERS
CAME ASHORE FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST. NOW
THERE IS IMPRESSIVE MODEL AGREEMENT AMONG PARAMETRIZED AND
CONVECTION ALLOWING MEMBERS ALIKE IN A MORE ROBUST ROUND OF
CONVECTION DEVELOPING AND MOVING ASHORE IN THE VICINITY OF TAMPA BAY
/ I-4 CORRIDOR AND NORTHWARD PASCO/HERNANDO/CITRUS COUNTIES FROM NOW
THROUGH DAWN. WITH A NEW IMPULSE APPROACHING THE NE GULF AND THE
VICINITY FOCUS OF A SURFACE TROUGH NEAR THE FLORIDA BIG BEND...IT IS
HARD TO DISAGREE WITH THIS MODEL CONSENSUS. HAVE RAMPED POPS UP FROM
TAMPA BAY / I-4 CORRIDOR NORTHWARD...ESPECIALLY AFTER 09-10Z. HRRR
AND LOCAL HI-RES WRFARW MEMBERS SHOW THE UPPER SUPPORT ALLOWING THIS
ACTIVITY TO PENETRATE QUICKLY INLAND AND WILL FOLLOW SUIT IN THE
FORECAST GRIDS. THIS IS A BIT DIFFERENT FROM THE CLIMO WESTERLY
NOCTURNAL SHOWERS WHICH ARE FORCED MAINLY FROM LOW LEVEL
INSTABILITY...AND GENERALLY FADE QUICKLY IN THE PRE-DAWN HOURS AFTER
REACHING SHORE.
THIS IS NOT A VERY CLIMATOLOGICAL SITUATION FOR LATE JULY...AND IT
THROWS SOME UNCERTAINTY INTO THE FORECAST. HOWEVER...AS MENTIONED
ABOVE...IT IS DIFFICULT TO IGNORE THE MODEL CONSENSUS...ESPECIALLY
SINCE ALL MEMBERS SEEM TO HAVE INITIALIZED THE MAIN PLAYING
INFLUENCES WELL THIS MORNING. THIS BAND OF HIGHER POPS FROM
HILLSBOROUGH/POLK COUNTIES NORTHWARD WILL CONTINUE THROUGH AT LEAST
MID-MORNING. THEREAFTER THE IMPULSE PASSES AND WE "SHOULD"
TRANSITION TO A MORE SEA-BREEZE/WEST FLOW DOMINATED SHOWER PATTERN
BY EARLY AFTERNOON. HOWEVER THE PRESENCE OF THE EARLY MORNING
SHOWERS/STORMS WILL ALSO INFLUENCE OUR HEATING AND DIURNAL FLOW
PATTERNS...THROWING MORE UNCERTAINLY INTO THE AFTERNOON FORECAST.
WILL DO OUR BEST EARLY THIS MORNING TO SORT ALL THIS OUT.
&&
.SHORT TERM (TODAY THROUGH SATURDAY)...
TODAY...THE MORNING FORECAST IS DETAILED IN THE SYNOPSIS ABOVE AND
WILL NOT REPEAT HERE. THE MORNING CONVECTION WILL DISRUPT THE FLOW
PATTERNS SOMEWHAT...BUT WILL ASSUME WE RECOVER EVENTUALLY AND END UP
WITH A MORE TYPICAL DISTRIBUTION OF MAINLY INLAND SHOWERS/STORMS
ASSOCIATED WITH WESTERLY FLOW FOR THE LATER PORTION OF THE DAY.
FAIRLY TIGHT GRADIENT WILL KEEP A STEADY ONSHORE FLOW AND CHOPPY
BREAKING SURF GOING ALONG OUR COASTS FOR ANOTHER DAY. EXTENDING THE
MODERATE RISK OF RIP CURRENTS THROUGH THIS EVENING FOR
PINELLAS...HILLSBOROUGH...MANATEE...AND SARASOTA COUNTIES.
TONIGHT...UPPER TROUGH AXIS WILL BEGIN TO SHIFT EAST...BUT STILL
KEEP OUR REGION UNDERNEATH AT LEAST A MINIMAL DEGREE OF CYCLONIC
FLOW. POTENTIALLY OF BIGGER INFLUENCE WILL BE A SOUTHWARD SHIFT OF
THE SURFACE TROUGH CURRENTLY NEAR THE I-10 CORRIDOR. THIS SHIFT
SOUTH IS SHOWN BY MANY OF THE ENSEMBLE NWP MEMBERS...BRINGING THE
LOW LEVEL FOCUS/WIND CONVERGENCE AXIS TO NEAR TAMPA BAY / I-4
CORRIDOR BY THE LATE NIGHT HOURS. WITH THIS IN MIND WOULD EXPECT YET
ANOTHER RESURGENCE OF NOCTURNAL SHOWERS (POSSIBLY MORE CONCENTRATED
THAN NORMAL) MOVING ASHORE FROM THE GULF AND MAKING SOME PROGRESS
INLAND. THE AXIS OF BEST RAIN CHANCES LOOKS TO BE FOCUSED A LITTLE
MORE SOUTH THAN THIS MORNING AND WILL SHOW BEST RAIN CHANCES
CENTERED FROM PASCO TO PINELLAS/HILLSBOROUGH AND SOUTH TO MANATEE
COUNTY BETWEEN SAY 09-15Z. THIS FORECAST REPRESENTS A BEST GUESS FOR
THE LOCATION OF THE CONVERGENT AXIS FOR ENHANCED LIFT BASED ON MODEL
CONSENSUS.
FRIDAY/FRIDAY NIGHT...HEIGHTS WILL FINALLY RIDGE NORTHWARD FROM THE
CENTRAL GULF OVER THE FL PENINSULA IN RESPONSE TO A SIGNIFICANT
SHORTWAVE AND ASSOCIATED HEIGHT FALLS DROPPING SOUTHWARD THROUGH THE
MID/LOWER MS VALLEY. AFTER THE MORNING SHOWER ACTIVITY FADES...THERE
IS HIGHER CONFIDENCE IN A MORE TYPICAL SEA-BREEZE INDUCED CONVECTIVE
PATTERN FOR THE SECOND HALF OF THE DAY. THE GRADIENT WILL BE WEAKER
BY THIS TIME...BUT STILL HAVE AT LEAST A MINIMAL WESTERLY SYNOPTIC
PUSH. THEREFORE...BY LATE IN THE AFTERNOON...MUCH OF THE CONVECTION
SHOULD BE PUSHED INLAND FROM THE I-75 CORRIDOR. FRIDAY NIGHT THE LOW
LEVEL GRADIENT LOOKS TO REALLY COLLAPSE...POTENTIALLY ALLOWING FOR A
WEAK LAND-BREEZE TO DEVELOP AFTER MIDNIGHT. EVENING CONVECTION OVER
THE INTERIOR SHOULD FADE BY 03-04Z...AND THEN WILL WATCH SOME
ISOLATED CELLS REDEVELOP JUST OFFSHORE ALONG THE DEVELOPING
LAND-BREEZE AFTER 09Z.
SATURDAY...VERY LIGHT GRADIENT IN PLACE WILL ALLOW DEFINED EAST
COAST AND WEST COAST SEA-BREEZES. WILL LIKELY SEE A SCATTERING OF
SHOWERS ALONG AND INSIDE OF THE I-75 CORRIDOR DURING THE LATE
MORNING AND EARLY AFTERNOON...WITH THE ACTIVITY THEREAFTER PUSHING
INLAND. MODELS ARE IN AGREEMENT IN A CLASSIC EAST AND WEST
SEA-BREEZE COLLISION ALONG THE SPINE OF THE PENINSULA LATE SATURDAY
AFTERNOON. THEREFORE IT MAY BE AN ACTIVE LATE AFTERNOON AND
ESPECIALLY EVENING OVER THE INTERIOR ZONES. ON THE OTHER
HAND...AFTER MIDDAY...MOST OF THE COAST SHOULD SEE RAIN CHANCES
FALL QUICKLY WITH A MOSTLY SUNNY AND QUIET AFTERNOON/EARLY EVENING
CURRENTLY IN THE FORECAST.
&&
.LONG TERM (SUNDAY THROUGH NEXT WEDNESDAY)...
THE PERIOD BEGINS WITH AN UPPER LOW OVER THE GREAT LAKES TROUGHING
SOUTH TO THE GULF COAST AND SE U.S. WHILE DEEP LAYER MEAN RIDGING
FROM THE OPEN ATLANTIC EXTENDS ACROSS THE BAHAMAS AND CUBA. DURING
THE FIRST PART OF NEXT WEEK THE UPPER LOW ROTATES ACROSS THE GREAT
LAKES INTO SE CANADA WITH THE TROUGHING LIFTING NORTH OF THE REGION.
THIS ALLOWS THE DEEP LAYER MEAN RIDGING TO BUILD IN ACROSS THE GULF
AS IT SHIFTS NORTH OVER FL. FOR THE VERY LAST DAY THE 25/00Z GFS HAS
WHAT IS CURRENTLY TROPICAL STORM DORIAN EAST OF THE BAHAMAS. THE
ECMWF FOR 25/00Z HAS A WEAK LOW OVER THE BAHAMAS.
AS THE TROUGHING MOVES AWAY AND THE RIDGE SLIDES ACROSS THE AREA
THERE WILL BE A SLIGHT DRYING TREND...WITH POPS GOING FROM 40-50
PERCENT TO 30-40 PERCENT FOR THE AFTERNOONS. LATE MORNINGS AND EARLY
EVENINGS WILL SEE ISOLATED POPS. WESTERLY LOW LEVEL FLOW GRADUALLY
BACKS THROUGH THE SOUTH TO SOUTHEASTERLY...AND RELAXED ENOUGH TO
PERMIT AFTERNOON SEA BREEZES TO FORM.
&&
.AVIATION...
PREVAILING VFR. A MIXTURE OF SHRA/TSRA IS EXPECTED TO IMPACT THE
NORTHERN TERMINALS/ SRQ NORTHWARD/ DURING THE MORNING HOURS BUT WILL
HOLD THE TAFS AT VCNTY FOR NOW. SOUTHERN TERMINALS...PGD/FMY/RSW
COULD SEE SOME VCSH FORM LATER IN THE MORNING. A CONTINUED WESTERLY
FLOW WILL PUSH ALL CONVECTION EAST OF ALL THE TERMINALS DURING THE
AFTERNOON. THERE COULD BE SOME OCNL BKN CIGS IN THE MVFR RANGE...TOO
LIMITED FOR TAF INCLUSION.
&&
.MARINE...
MODERATE WESTERLY FLOW WILL CONTINUE ACROSS THE EASTERN GULF OF
MEXICO BETWEEN THE SUBTROPICAL RIDGE AXIS TO THE SOUTH OF THE
FLORIDA PENINSULA. WINDS WILL AT TIMES APPROACH CAUTIONARY LEVELS
TODAY...AND THEN BEGIN TO DIMINISH OVERNIGHT AND FRIDAY AS THE
SURFACE TROUGH SINKS SOUTH AND WEAKENS THE LOCAL GRADIENT. THE WEAK
GRADIENT WILL LINGER THROUGH THE WEEKEND KEEPING WINDS AND SEAS LOW
AND ALLOWING THE RETURN OF AFTERNOON SEA-BREEZES. THE SUBTROPICAL
RIDGE AXIS LOOKS TO BUILD NORTH OVER THE EASTERN GULF OF MEXICO
DURING THE EARLY PORTION OF NEXT WEEK KEEPING WINDS AND SEAS LOW
THROUGH THE END OF THE FORECAST PERIOD.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO REMAIN WELL ABOVE CRITICAL
LEVELS THROUGH THE NEXT SEVERAL DAY. HOWEVER...ELEVATED FLOW ALOFT
WILL RESULT IN HIGH DISPERSION INDICES TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 78 92 78 / 50 40 40 10
FMY 91 77 90 77 / 20 20 30 20
GIF 90 75 94 74 / 50 30 50 30
SRQ 89 78 91 78 / 30 40 40 20
BKV 90 72 93 72 / 50 30 40 20
SPG 90 79 91 79 / 50 40 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THIS EVENING FOR HILLSBOROUGH-
MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1235 AM EDT THU JUL 25 2013
...UPDATED TO DISCUSS HIGHER CONVECTIVE POTENTIAL THIS MORNING...
.UPDATE...
OCCASIONAL WEAK IMPULSES CONTINUE TO RIDE THE FLOW DOWN THE BACKSIDE
OF AN EASTERN UNITED STATES UPPER TROUGH INTO THE SOUTHEASTERN
STATES AND ENHANCE ROUNDS OF SCT CONVECTION OFF THE NORTHEAST GULF
OF MEXICO. ONE ROUND OF LATE EVENING SHOWERS CAME ASHORE FROM TAMPA
BAY NORTHWARD ALONG THE NATURE COAST...AND NOW THERE IS IMPRESSIVE
MODEL AGREEMENT AMONG PARAMETRIZED AND CONVECTION ALLOWING MEMBERS
ALIKE IN A MORE ROBUST ROUND OF CONVECTION DEVELOPING AND MOVING
ASHORE IN THE VICINITY OF THE I-4 CORRIDOR AND NORTHWARD LATE NIGHT
TOWARD DAWN. WITH A NEW IMPULSE APPROACHING THE NE GULF IN THE NEXT
SEVERAL HOURS AND THE VICINITY FOCUS OF A SURFACE TROUGH NEAR THE
FLORIDA BIG BEND...IT IS HARD TO DISAGREE WITH THIS MODEL CONSENSUS.
HAVE RAMPED POPS UP FROM TAMPA BAY / I-4 CORRIDOR NORTHWARD...
ESPECIALLY AFTER 09Z. HRRR AND LOCAL HI-RES WRFARW MEMBERS SHOW THE
UPPER SUPPORT ALLOWING THIS ACTIVITY TO PENETRATE QUICKLY INLAND AND
WILL FOLLOW SUIT IN THE FORECAST GRIDS. THIS IS A BIT DIFFERENT FROM
THE CLIMO WESTERLY NOCTURNAL SHOWERS WHICH ARE FORCED MAINLY FROM
LOW LEVEL INSTABILITY...AND GENERALLY FADE QUICKLY IN THE PRE-DAWN
HOURS AFTER REACHING SHORE.
THIS IS NOT A VERY CLIMATOLOGICAL SITUATION FOR LATE JULY...AND IT
THROWS SOME UNCERTAINTY INTO THE FORECAST. HOWEVER...AS MENTIONED
ABOVE...IT IS DIFFICULT TO IGNORE THE MODEL CONSENSUS...ESPECIALLY
SINCE ALL MEMBERS SEEM TO HAVE INITIALIZED THE MAIN PLAYING
INFLUENCES WELL THIS MORNING. THIS BAND OF HIGHER POPS FROM
HILLSBOROUGH/POLK COUNTIES NORTHWARD WILL CONTINUE THROUGH AT LEAST
MID-MORNING. THEREAFTER THE IMPULSE PASSES AND WE "SHOULD"
TRANSITION TO A MORE SEA-BREEZE/WEST FLOW DOMINATED SHOWER
PATTERN...HOWEVER THE PRESENCE OF THE EARLY MORNING SHOWERS/STORMS
WILL ALSO INFLUENCE OUR HEATING AND DIURNAL FLOW PATTERNS...THROWING
MORE UNCERTAINLY INTO THE AFTERNOON FORECAST. WILL DO OUR BEST EARLY
THIS MORNING TO SORT ALL THIS OUT.
&&
.AVIATION...
GENERALLY VFR CONDITIONS EXPECTED...BUT CAN/T RULE OUT A SHRA
DRIFTING ONSHORE FROM KSRQ NORTHWARD THIS EVENING. BETTER CHANCES
FOR SHRA LATER TONIGHT 08/09Z AND WILL INCLUDE VCSH TO ACCOUNT
FOR THIS. SOUTH OF KSRQ...VFR CONDITIONS ARE EXPECTED THROUGH THE
OVERNIGHT HOURS. BEST CHANCE OF TSRA WILL BE EAST OF ALL TERMINALS
THURSDAY...SO WILL NOT MENTION VCTS AT ANY OF THE TAF SITES. HAVE
INCLUDED VCSH AT MOST PROBABLE TIMES AT ALL TAF SITES...BUT HIGHEST
RAIN CHANCES WILL CONTINUE TO BE FROM KSRQ NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 89 79 91 / 50 50 20 20
FMY 78 91 78 91 / 20 20 10 20
GIF 75 91 75 93 / 40 50 10 40
SRQ 80 89 79 89 / 30 30 10 20
BKV 74 90 73 93 / 50 50 20 20
SPG 81 88 82 90 / 40 40 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 6 AM EDT THURSDAY FOR HILLSBOROUGH-
MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JELSEMA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EDT THU JUL 25 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW NW FLOW INTO THE UPPER
GREAT LAKES...RESULTING FROM A RIDGE OVER WRN N AMERICA AND A TROF
OVER ERN NAMERICA. WEAK REMNANT OF SHORTWAVE THAT WAS OVER CNTRL
SASKATCHEWAN 24HRS AGO IS NOW PASSING OVER THE UPPER GREAT LAKES.
12Z KINL SOUNDING SHOWED A CAP AROUND 12.5KFT MSL...AND LATEST SPC
ANALYSIS SHOWS MUCAPE ONLY 100-200J/KG. BOTH DO NOT SUPPORT MUCH OF
A SHRA POTENTIAL. KMQT RADAR IS OUT OF SERVICE UNTIL LATE THU
MORNING/EARLY AFTN WHILE PARTS ARE IN TRANSIT...SO NOT CERTAIN IF
THERE HAS BEEN ANY SHRA OVER W OR CNTRL UPPER MI THIS AFTN. HOWEVER...
KGRB/KDLH RADARS HAVE INDICATED A FEW RETURNS...SO THERE MIGHT BE A
FEW SPRINKLES OR PERHAPS A -SHRA OUT THERE. UPSTREAM...ISOLD/SCT
CONVECTION IS NOTED NW AND N OF LAKE SUPERIOR...TYPICAL FOR
SUMMERTIME NW FLOW. FARTHER UPSTREAM...A LARGER SCALE TROF EXTENDING
FROM WRN HUDSON BAY TO NRN ALBERTA IS DROPPING S. THIS FEATURE WILL
BE THE PLAYER IN THE WEATHER HERE THU THRU SAT.
WITH LOSS OF DAYTIME HEATING...ANY ONGOING ISOLD SHRA/SPRINKLES
WILL DISSIPATE THIS EVENING. HOWEVER...ANOTHER SUBTLE SHORTWAVE IS
NOTED OVER SRN MANITOBA...AND IT IS SUPPORTING MUCH OF THE ISOLD/SCT
SHRA/TSRA ACTIVITY OVER SE MANITOBA INTO ADJACENT NRN ONTARIO/NRN
MN. THIS WAVE COMBINED WITH WAA REGIME COULD HELP MAINTAIN A FEW
SHRA/POSSIBLE TSRA THRU THE NIGHTTIME HRS AS IT CONTINUES TO THE SE.
SO...WILL INCLUDE SCHC POPS OVER THE W LATE IN THE NIGHT.
ON THU...AFOREMENTIONED LARGER SCALE TROF WILL PIVOT SE INTO NRN
ONTARIO AND SRN MANITOBA/SRN SASKATCHEWAN. ASSOCIATED BROAD...BUT
ORGANIZING SFC LOW WILL REACH VCNTY OF WRN LAKE SUPERIOR LATE IN THE
DAY. THERE MAY BE A FEW SHRA/PERHAPS TSRA DURING THE MORNING HRS
WITHIN WAA REGIME. OTHERWISE...BUILDING INSTABILITY IN THE AFTN AND
APPROACHING HEIGHT FALLS AS LARGER SCALE TROF SWINGS CLOSER WILL
LIKELY RESULT IN INCREASING COVERAGE OF SHRA/TSRA DURING THE DAY.
WITH NAM/GFS MLCAPE INCREASING TO UPWARDS OF 1000J/KG AND DEEP LAYER
SHEAR PROGGED AT 30-40KT...EXPECT SOME STORM ORGANIZATION...LEADING
TO THE POSSIBILITY OF A FEW STRONGER STORMS. IF THERE IS SUFFICIENT
DAYTIME HEATING TO RAISE CAPE TO THE MODEL VALUES...THEN THERE WILL
BE THE POTENTIAL FOR ISOLD SVR STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
A LINE OF SHOWERS AND THUNDERSTORMS WILL BE MOVING ACROSS THE AREA
AT THE START OF THE LONG TERM PERIOD. THIS IS DUE TO A TROUGH
DIGGING SOUTHEAST INTO NORTHERN MINNESOTA AND PRODUCING A
BROAD/WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. THE GENERAL
TREND OVER THE LAST COUPLE OF DAYS IS FOR THE SHORTWAVE AND LOW
TRACK TO BE FARTHER SOUTH...WHICH INFLUENCES THE WEATHER FOR THE
WEEKEND. BEFORE THAT...THE SHOWERS AND THUNDERSTORMS WILL BE MOVING
EAST ACROSS CENTRAL AND EASTERN UPPER MICHIGAN DURING THE EVENING
AND INTO THE OVERNIGHT HOURS. WITH LIMITED INSTABILITY AND LOSS
OF DIURNAL HEATING...THINK THE SEVERE POTENTIAL IS MARGINAL EVEN
THOUGH 0-6KM SHEAR VALUES ARE IN THE 35-40KT RANGE. AS THE FIRST
WAVE OF PRECIPITATION MOVES EAST...THINK THERE WILL BE LINGERING
CLOUDS AND A FEW RAIN SHOWERS OVER THE WEST THROUGH THE NIGHT WITH
THE BROAD/WEAK LOW MOVING OVER THE WESTERN U.P.
SECOND SHORTWAVE WILL ARRIVE ON FRIDAY (WEST MORNING AND EAST
AFTERNOON) AND KICK OFF ANOTHER PERIOD OF NUMEROUS SHOWERS. SINCE
THE LOW WILL HAVE SHIFTED TOWARDS CENTRAL UPPER MICHIGAN...ANY
INSTABILITY (MUCAPE VALUES UNDER 750 J/KG) WILL BE ALIGNED ALONG AND
EAST OF THAT LOCATIONS...SO WILL CONFINE THE BEST THUNDER CHANCES
THERE. SINCE 0-6KM SHEAR VALUES ARE ONLY 15-20KTS...HEAVY RAIN
WOULD BE THE MAIN THREAT.
THIS SECOND SHORTWAVE WILL ALSO CAUSE THE TROUGH TO WRAP UP INTO A
CLOSED LOW OVER THE UPPER GREAT LAKES ON FRIDAY NIGHT AND REMAIN
IN THE AREA INTO SUNDAY MORNING. THIS WILL LEAD TO WEATHER MORE
LIKE LATE SEPTEMBER INSTEAD OF LATE JULY. DURING THAT
TIME...EMBEDDED WAVES AND INCREASED MOISTURE WILL LEAD TO CLOUDY
CONDITIONS...PERIODS OF RAIN (ESPECIALLY OVER THE NORTH
HALF)...GUSTY NORTHWEST WINDS (FRIDAY NIGHT INTO
SATURDAY EVENING)...AND TEMPERATURES WELL BELOW NORMAL (50S AND
LOW 60S SATURDAY). TEMPERATURES ON SATURDAY MAY BE SOMETHING TO
KEEP AN EYE ON...SINCE SOME OF THE RAW MODELS ARE INDICATING HIGHS
IN THE UPPER 40S OR LOW 50S OVER THE NORTHWEST HALF OF THE U.P.
LOOKING AT SOME PAST HIGHS...THE RECORD COLDEST JULY HIGH
TEMPERATURES FOR MANY SITES ARE IN THAT RANGE (NWS MQT 51 IN
2004/1992...CMX 49 IN 1992...IRONWOOD 52 IN 2009/1997).
MOST LIKELY PERIOD FOR DRIER WEATHER WILL BE SUNDAY AFTERNOON INTO
MONDAY AFTERNOON...AS THE UPPER LOW SHIFTS NORTHEAST INTO QUEBEC
AND WEAK HIGH PRESSURE SLIDES ACROSS THE AREA. MODELS CONTINUES TO
STRUGGLE ON THAT TIMING WITH THE SPEED OF THE UPPER LOW
EXITING...WHICH IS USUALLY THE CASE. ONCE THE LOW SHIFTS
NORTHEAST...A SERIES OF SHORTWAVES LOOK TO MOVE ACROSS THE UPPER
GREAT LAKES MONDAY NIGHT INTO TUESDAY NIGHT. WILL CONTINUE TO
MENTION LOW END CHANCE POPS FOR THESE SHORTWAVES MOVING THROUGH.
AFTER THE COOL WEEKEND...TEMPERATURES SHOULD REBOUND TO MORE NORMAL
VALUES FOR THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1210 AM EDT THU JUL 25 2013
EXPECT VFR CONDITIONS/DRY WX EARLY THIS MRNG BEFORE THE APPROACH OF
A LO PRES TROF BRINGS THE THREAT OF SOME SHRA AT THE WESTERN SITES
TOWARD SUNRISE. A BETTER CHC FOR THE SHRA AND SOME TS WL BE AFT
18Z...WHEN DAYTIME HEATING WL INCRS INSTABILITY. THE BEST
OPPORTUNITY FOR THE TS WL BE AT SAW...WHERE LLVL MSTR SURGE IS IN
BETTER SYNC WITH THE DYNAMIC SUPPORT AND DAYTIME HEATING. WITH MORE
OPPORTUNITY FOR SOME COOLING OFF LK SUP...THE CHC FOR TS IS LOWEST
AT CMX. SINCE THE LLVLS WL BE FAIRLY DRY...VFR CONDITIONS SHOULD
PREVAIL THRU THE DAY...BUT LOWER CONDITIONS COULD OCCUR UNDER THE
HEAVIER SHRA/TS. SOME LO CLDS COULD IMPACT CMX IN THE EVNG FOLLOWING
THE LOSS OF DAYTIME HEATING AND WITH AN INFLUX OF SOME LK COOLED AIR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT WED JUL 24 2013
WITH HIGH PRES DEPARTING TO THE E AND LOW PRES APPROACHING FROM THE
NW...S WINDS WILL BE THE RULE TONIGHT AND THU...THOUGH SPEEDS SHOULD
REMAIN UNDER 20KT. IF THERE ARE ANY STRONGER WINDS...THEY WILL OCCUR
OVER ERN LAKE SUPERIOR THU AFTN/EVENING. ONCE THE LOW MOVES E OF
LAKE SUPERIOR...WINDS WILL SHIFT AROUND TO THE N TO NW FRI. GIVEN
THE INCOMING CHILLY AIR MASS FOR THIS TIME OF YEAR...IT LOOKS LIKE
THERE WILL BE A PERIOD OF 15-25KT WINDS OVER MAINLY CNTRL LAKE
SUPERIOR FRI NIGHT INTO SAT. HOWEVER...IT`S NOT OUT OF THE QUESTION
THAT WINDS COULD BE HIGHER DUE TO THE UNSEASONABLY COOL AIR MASS
PUSHING OVER THE AREA. WINDS WILL DIMINISH SUN/MON AS HIGH PRES
BUILDS INTO THE WRN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
436 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIMEFRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEWPOINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 936 PM CDT WED JUL 24 2013
THINKING HASN/T CHANGED MUCH FROM PREVIOUS SET OF TAFS. THE MAIN
DIFFERENCE IS WITH THE ACTIVITY CURRENTLY MOVING INTO THE NORTHERN
PART OF THE FORECAST AREA... WHICH WAS A MILD CONCERN EARLIER.
IT IS LASTING LONGER THAN MUCAPE AND ANY LLJ FORCING WOULD
SUGGEST... SO MAY NEED TO ACCOUNT FOR IT AT AT LEAST KSTC.
HOWEVER... STILL WOULD EXPECT IT TO HAVE TROUBLE MOVING VERY FAR
EAST INTO MORE STABLE AIR. CONFIDENCE REMAINS FAIRLY LOW ON
TIMING/LOCATION OF SHRA/TSRA ON THURSDAY... ALTHOUGH THERE IS
STILL GOOD CONFIDENCE ON OCCURRENCE SOMEWHERE ACROSS THE AREA.
SO... CONTINUED TO MAINLY HIT CHANCES FOR EASTERN SITES... BUT NOT
GO TOO PESSIMISTIC WITH RESPECT TO FLIGHT CONDITIONS GIVEN LACK OF
CONFIDENCE OF WHEN/WHERE THINGS WILL OCCUR.
KMSP...TAF REFLECTS EXPECTATIONS WITH MAIN UNCERTAINTIES BEING
IF/WHEN SHRA/TSRA WILL OCCUR ON THURSDAY. IF WE DO SEE SOME STORMS
AT THE SITE... WE/LL MORE THAN LIKELY GET DOWN INTO MVFR FLIGHT
CONDITIONS. WILL STILL NEED TO KEEP AN EYE ON ACTIVITY CURRENTLY
TO THE NORTHWEST... WHICH IF IT SURVIVES WOULD ARRIVE SOMETIME
BEFORE 09Z. BUT... LEFT IT OUT FOR NOW WITH EXPECTATION IT WILL
WEAKEN.
/OUTLOOK FOR KMSP/
FRI...VFR. MVFR POSSIBLE WITH A CHANCE OF SHRA. NW WIND 10-20 KT.
FRI NIGHT...MVFR CIGS POSSIBLE...OTHERWISE VFR. NW WIND 5-15 KT.
SAT...VFR. NW WIND 10-20 KT.
SAT NIGHT...VFR EXPECTED. MVFR CIGS POSSIBLE. VRBL WIND LESS THAN
10 KT.
SUN...VFR EXPECTED. MVFR CIGS POSSIBLE EARLY. N WIND LESS THAN 10
KT BECOMING VRBL.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
305 AM CDT THU JUL 25 2013
.DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
...AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
...BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS EXPECTED FOR MOST OF THE PERIOD WITH BKN-OVC
HIGH CLOUDS. MVFR CIGS AND VSBYS IN THUNDERSTORMS POSSIBLE AFTER
18Z AS COLD FRONT MOVES INTO THE AREA...BUT NOT IN FORECAST AT
THIS TIME DUE TO TIMING UNCERTAINTY.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
310 AM MDT THU JUL 25 2013
.DISCUSSION...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
&&
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.AVIATION...
06Z TAF CYCLE
PRECIPITATION HAS DIMINISHED SIGNIFICANTLY OVER NORTHERN AND
CENTRAL NEW MEXICO. SOME BATCHES OF LIGHT TO MODERATE RAIN ARE
CONTINUING OVER EASTERN PARTS OF THE STATE...AND WILL MOST LIKELY
IMPACT TAF SITES KLVS...KTCC...AND KROW THROUGH 25/1200UTC. SOME
STORMS IN SOUTHERN NEW MEXICO MAY CREEP NORTHWARD TOWARD KONM AND
NEARBY POINTS THROUGH THE MORNING...BUT OVERALL ACTIVITY WILL
CONTINUE A DOWNWARD TREND THROUGH THE OVERNIGHT. SCATTERED TO
NUMEROUS STORMS WILL REDEVELOP OVER NORTHERN AND CENTRAL NEW
MEXICO ON THURSDAY AS THE ATMOSPHERE DESTABILIZES AGAIN.
52
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 93 64 95 65 / 20 10 20 20
DULCE........................... 84 51 86 53 / 40 20 30 50
CUBA............................ 87 55 87 54 / 40 20 40 60
GALLUP.......................... 85 58 88 59 / 40 30 40 30
EL MORRO........................ 79 53 80 54 / 50 30 40 40
GRANTS.......................... 83 58 85 58 / 40 30 30 40
QUEMADO......................... 79 57 83 57 / 50 30 40 40
GLENWOOD........................ 80 60 85 60 / 40 30 30 30
CHAMA........................... 76 49 77 50 / 50 30 40 60
LOS ALAMOS...................... 80 60 82 59 / 40 30 40 50
PECOS........................... 75 57 75 56 / 60 30 50 60
CERRO/QUESTA.................... 78 53 79 54 / 50 30 50 50
RED RIVER....................... 68 46 69 45 / 60 40 50 70
ANGEL FIRE...................... 72 43 72 43 / 60 30 50 70
TAOS............................ 80 52 83 53 / 40 30 40 40
MORA............................ 74 53 74 53 / 60 30 50 60
ESPANOLA........................ 85 59 87 59 / 40 20 30 40
SANTA FE........................ 79 59 80 59 / 50 30 40 50
SANTA FE AIRPORT................ 83 61 83 60 / 50 30 40 50
ALBUQUERQUE FOOTHILLS........... 85 68 87 66 / 50 30 40 50
ALBUQUERQUE HEIGHTS............. 87 69 88 67 / 50 30 30 50
ALBUQUERQUE VALLEY.............. 89 68 90 67 / 50 30 30 50
ALBUQUERQUE WEST MESA........... 92 67 92 66 / 50 30 30 50
LOS LUNAS....................... 87 66 89 66 / 50 30 30 50
RIO RANCHO...................... 91 66 92 65 / 50 30 30 50
SOCORRO......................... 89 67 92 66 / 60 30 30 40
SANDIA PARK/CEDAR CREST......... 82 60 84 59 / 60 40 40 50
TIJERAS......................... 83 61 83 60 / 60 30 40 50
MORIARTY/ESTANCIA............... 81 59 82 58 / 60 30 40 50
CLINES CORNERS.................. 78 58 79 57 / 60 40 50 50
GRAN QUIVIRA.................... 80 61 83 59 / 60 30 50 40
CARRIZOZO....................... 84 64 85 63 / 60 30 40 30
RUIDOSO......................... 77 57 76 55 / 70 40 50 40
CAPULIN......................... 79 55 77 55 / 60 30 20 30
RATON........................... 83 58 82 57 / 60 30 30 30
SPRINGER........................ 84 58 83 57 / 60 30 20 30
LAS VEGAS....................... 79 56 79 56 / 60 30 40 50
CLAYTON......................... 86 64 83 61 / 60 40 10 10
ROY............................. 81 62 81 61 / 60 40 20 30
CONCHAS......................... 87 68 87 66 / 60 40 20 20
SANTA ROSA...................... 85 67 87 65 / 60 40 20 20
TUCUMCARI....................... 90 70 90 68 / 60 40 10 10
CLOVIS.......................... 88 67 88 63 / 60 40 20 10
PORTALES........................ 88 68 89 63 / 60 40 20 10
FORT SUMNER..................... 87 70 88 67 / 60 40 20 10
ROSWELL......................... 92 71 92 70 / 70 30 20 20
PICACHO......................... 87 64 86 63 / 70 30 30 30
ELK............................. 80 61 79 59 / 70 30 40 50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES...
NMZ508-509-520-524>526-539-540.
&&
$$
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
342 AM CDT THU JUL 25 2013
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL FOR THE MOST PART OVERNIGHT AND
THROUGH THE DAY THURSDAY. SCATTERED SHOWERS AND THUNDERSTORMS MAY
PUSH INTO THE WESTERN CWA BY SUNRISE OR SO AND WILL REMAIN
POSSIBLE THROUGH THE DAYTIME HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
127 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL HEAD SOUTH OF THE AREA OVERNIGHT...AND ITS
ASSOCIATED UPPER TROUGH WILL CROSS THE REGION ON THURSDAY. HIGH
PRESSURE WILL SETTLE OVER THE AREA BY FRIDAY...AND SHIFT EAST TO
THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE THROUGH THE
AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1130 PM EDT WEDNESDAY...
MODELS HAVE BEEN DOING PRETTY GOOD IN ADVERTISING CONVECTION OVER
THE PIEDMONT THIS EVENING AND STEERING IT WORD THE NC/VA BORDER.
WILL MAINTAIN CHANCE POPS...AS HIGH AS 50 ACROSS THE FAR SE THEN
TAPER TO SLIGHT FURTHER NW ACROSS THE FOOTHILLS OVERNIGHT.
PREVIOUS DISCUSSION...
AS OF 730 PM...
AN AXIS OF HIGHER INSTABILITY AND DECENT LOW LVL LAPSE RATES
EXISTS FROM WRN NC EAST INTO THE PIEDMONT OF NC/VA WITH SUBSIDENCE
AND DRIER AIR WORKING TOWARD SOUTHEAST WV. RADAR AT THE MOMENT
SHOWS CONVECTION SLOWLY TRUDGING EAST ACROSS THE BLUE RIDGE
MOUNTAINS AND FOOTHILLS NORTH OF LYNCHBURG VA...WITH ISOLATED
SHOWERS AND STORMS STARTING TO FADE FROM NE TN INTO THE FOOTHILLS
OF NORTH CAROLINA.
KEPT HIGHER POPS SITUATED ACROSS THE NORTHEAST PIEDMONT OF
BUCKINGHAM SOUTH TO SOUTHSIDE VA AND THEN WEST TOWARD WILKES
COUNTY NC THIS EVENING WITH DRIER WX IN THE NORTHWEST.
18Z NAM/GFS...12Z ECMWF AND THE LATEST HRRR SHOWING OVERALL
AGREEMENT IN BRING A CLUSTER OF SHOWERS/STORMS ACROSS THE
SOUTHEAST CWA AROUND 03Z AS THE UPPER SHORTWAVE MOVES EAST OF OUT
TN. BUMPED POPS UP SOME HERE AND MAY NEED TO GO EVEN HIGHER IF
THIS HAPPENS. BIG CONSIDERATION IS INSTABILITY WEAKENING AS SUN
SETS BUT GIVEN HOW WARM IT IS OUT THERE NOW AND ADDING SOME UPPER
LIFT...THINKING IS CONVECTION SHOULD MAINTAIN ITSELF ACROSS THE
NORTH CAROLINA FOOTHILLS PIEDMONT AND NWD TOWARD SOUTHSIDE VA INTO
THE OVERNIGHT HOURS...WITH THE LIGHTNING SIDE OF THINGS SUBSIDING
OVERNIGHT.
PREVIOUS VALID DISCUSSION...
THE FRONT IS EXPECTED TO HAVE MOVED SOUTH THROUGH MOST...IF NOT
ALL...OF THE REGION BY MIDNIGHT. BEHIND THE FRONT...SURFACE AND
LOW LEVELS WINDS ARE PROGGED TO VEER NORTHEAST TO ALMOST EAST IN
SOME AREAS. THIS WILL HAVE THE IMPACT OF KEEPING LINGERING
MOISTURE IN THE BOUNDARY LAYER PINNED UP AGAINST THE CREST OF THE
BLUE RIDGE. WE ARE EXPECTING STRATUS CLOUDS TO DEVELOP OVERNIGHT
AND LOWER AS THE NIGHT PROGRESSES. THIS MAY ALSO HELP YIELD SOME
DRIZZLE IN THE CREST OF THE BLUE RIDGE. PATCHY OR AREAS OF FOG ARE
ALSO EXPECTED ALONG AND NEAR THE PORTION OF THE BLUE RIDGE
SOUTHWEST OF ROANOKE. THE PROXIMITY OF THE FRONT WILL ALSO HELP
MAINTAIN SOME SHOWERS ACROSS THE SOUTHEAST PART OF THE REGION. LOW
TEMPERATURES TONIGHT WILL BE AROUND 5 TO 8 DEGREES COOLER THAN
TEMPERATURES REALIZED THIS MORNING THANKS TO LOWERING DEW POINTS
BEHIND THE FRONT.
ON THURSDAY...CLOUD COVER WILL BE SLOW TO ERODE...ESPECIALLY ALONG
AND EAST OF THE BLUE RIDGE SOUTHWEST OF ROANOKE. THIS REGION WILL BE
CLOSEST TO THE DEPARTING COLD FRONT AS IT DEVELOPS A SMALL BUCKLE IN
IT WITH THE PASSAGE OF THE PARENT UPPER TROUGH. ALSO...SURFACE
AND LOW LEVEL WINDS WILL HAVE A GREATER EASTERLY COMPONENT. THIS
POINTS TOWARDS THE AREA KEEPING THE CLOUDS LONGER WITH ISOLATED TO
SCATTERED SHOWERS AND A FEW STORMS. HIGHS TOMORROW WILL BE SIMILAR
OR ONLY SLIGHTLY COOLER THAN TEMPERATURES OF TODAY ACROSS THE
MOUNTAINS. OVER THE PIEDMONT...HIGHS WILL BE AROUND 10 DEGREES
COOLER THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 400 PM EDT WEDNESDAY...
THE SHORT TERM WILL BE DOMINATED BY A BROAD EASTERN U.S.
TROUGH...CONTINUALLY REINFORCED BY UPSTREAM SHORT WAVES. AT THE
BEGINNING OF THE SHORT TERM...THE TROUGH AXIS ATTEMPTS TO SHIFT EAST
OF THE AREA AS A COASTAL LOW MOVES UP AND JUST OFF THE MID-ATLANTIC
COAST. HOWEVER...A STRONG UPSTREAM SHORT WAVE MOVING SOUTHEAST OUT
OF ALBERTA...WILL SHIFT THE TROUGH AXIS BACK INTO THE OHIO VALLEY BY
SATURDAY. WITH SUBSIDENCE EXPECTED BEHIND THE DEPARTING COASTAL LOW
AND NOTABLY DRY AIR...DEW POINTS IN THE 50S/LOW 60S...ADVECTING INTO
THE NW HALF OF THE CWA...HAVE CONFINED SLIGHT CHC POPS TO THE FAR
SOUTHEAST AND POTENTIAL EASTERLY FLOW UPSLOPE AREAS IN THE NW NC
MOUNTAINS AT THE BEGINNING. UPSLOPE EASTERLY FLOW WILL INCREASE
SATURDAY ALONG THE ALLEGHANYS AND BLUE RIDGE OF NW NC...SO HAVE
CONTINUED TO INCREASE POPS IN THE WESTERN AREAS AS A RESULT FOR FRI
AFTERNOON. BY SATURDAY...OUR ATTENTION TURNS TO THE UPSTREAM DIGGING
TROUGH...WHICH SHOULD BE THE NEXT WIDESPREAD PCPN EVENT FOR OUR CWA.
TOO FAR OUT TO BE CONCERNED ABOUT RAINFALL AMOUNTS...BUT THIS WOULD
BE THE NEXT TIME FRAME FOR ANY SIGNIFICANT SEVERE OR FLASH FLOOD
THREAT. HAVE GONE AHEAD AND ADVERTISED LIKELY POPS FOR SAT
AFTERNOON/EVENING IN THE WEST.
SOMEWHAT COOLER MIN TEMPS WILL BE NOTED AT THE
BEGINNING...ESPECIALLY IN THE WEST WITH DEWPOINTS DROPPING INTO THE
50S ACROSS THE ALLEGHANYS. LOWS SHOULD BE IN THE MID TO UPPER 50S IN
THE HIGHER ELEVATIONS ACROSS SW VA/NW NC/SE WV. BY SATURDAY...WITH
SW FLOW RETURNING AND INCREASING MOISTURE...MIN TEMPERATURES WILL
CREEP CLOSER TO NORMAL. MAX TEMPS SHOULD AVERAGE JUST BELOW NORMAL
THROUGH THE PERIOD. OVERALL...CONTINUED BELOW NORMAL AS MOST OF THIS
SUMMER HAS BEEN SO FAR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
AS OF 120 AM EDT THURSDAY...
CONVECTION CONTINUES TO PERSIST ALONG AND SE OF THE BLUE RIDGE
ATTM AND EXPECT COVERAGE TO CONSOLIDATE A BIT SOUTH/SW OF KDAN IN
THE NEXT HOUR OR TWO BEFORE CELLS FINALLY WEAKEN. ALSO SEEING A
FEW SHRA FARTHER NORTH NEAR KROA SO WILL BE INCLUDING A VCSH
MENTION THERE TO KLYH AND PERHAPS PREVAILING -SHRA AROUND KDAN
OVERNIGHT. OTRW DEWPOINT FRONT REMAINS STUCK JUST EAST OF THE BLUE
RIDGE WITH LOW LEVEL NE FLOW AIDING CONVERGENCE WHICH HAS ALSO
SHIFTED LOWER CLOUDS WEST INTO SE WVA. THUS THINKING WILL SEE AT
LEAST MVFR CIGS OUT EAST THROUGH DAYBREAK THU WITH PERIODS OF IFR
ONCE SHRA FADE SOME AND STRATUS DEVELOPS. ALSO MAY SEE BASES LOWER
TO MVFR LEVELS BACK TO KBCB AND POSSIBLY INTO KBLF AND KLWB WHERE
MORE FOG AND MVFR/IFR VSBYS LIKELYS AS WELL.
FOR THURSDAY...THE FLOW REMAINS OUT OF THE NORTHEAST TO AT TIME
EAST...SO CIGS MAY LINGER THROUGH THIS PERIOD...WITH VFR EXPECTED
AFTER 15-17Z. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH OF ROANOKE BUT CANNOT RULE OUT KBCB/KROA AND MAYBE EVEN KBLF
SEEING SHOWERS OR STORMS NEARBY.
THURSDAY EVENING...THE AXIS OF THE UPPER TROUGH PASSES OVERHEAD.
EVEN THOUGH DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN
ISSUE AT BCB/LWB GIVEN WET SOILS AND LIGHT WIND.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
357 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
TODAY WITH THE POTENTIAL FOR STRONG TO SEVERE STORMS. FOCUS THEN
TURNS TO SHOWER AND STORM CHANCES FRIDAY...THEN ONTO TEMPERATURES
FOR THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST
FLOW ALOFT ACROSS THE UPPER MIDWEST. SEVERAL EMBEDDED SHORTWAVES
NOTED IN THE THE FLOW WITH A LEADING WEAK WAVE OVER SOUTH CENTRAL
MINNESOTA AND ANOTHER WAVE MOVING INTO NORTHWEST SOUTH DAKOTA. A
POTENT TROUGH WAS DIGGING INTO SOUTHERN SASKATCHEWAN/MANITOBA. THIS
TROUGH WILL BRING FALL-LIKE TEMPERATURES TO THE REGION FOR THE
WEEKEND. SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM
NORTH CENTRAL MINNESOTA SOUTHWEST ACROSS SOUTHERN NORTH DAKOTA AND
WAS PUSHING SOUTHEAST. A PREFRONTAL TROUGH WAS NOTED AS WELL
STRETCHING FROM NORTHEAST MINNESOTA SOUTH THROUGH CENTRAL MINNESOTA
INTO EASTERN SOUTH DAKOTA.THE TROUGH AND COLD FRONT WILL BE THE
FOCUS FOR SHOWER AND STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
AFTERNOON HOURS AND INTO THIS EVENING.
ISOLATED SHOWERS AND STORMS WILL JUST EDGE INTO SOUTHEAST MINNESOTA
AND WEST CENTRAL WISCONSIN THIS MORNING AS WEAK 850 MB MOISTURE
TRANSPORT MOVES INTO THE AREA. THIS ACTIVITY SHOULD WEAKEN AS IT
SLIDES SOUTHEAST THIS MORNING. ADDITIONAL DEVELOPMENT IS EXPECTED BY
LATE MORNING ALONG THE PREFRONTAL TROUGH LATE THIS MORNING INTO THE
EARLY AFTERNOON HOURS. MID AND HIGH LEVEL CLOUDS WORKING INTO THE
AREA FROM THE WEST WILL HAVE AN IMPACT ON HOW MUCH SURFACE
TEMPERATURES WARM TODAY. DEPENDING ON HOW MUCH WARMING
OCCURS...SEVERE THUNDERSTORMS ARE POSSIBLE MAINLY IN THE 3 TO 8 PM
TIMEFRAME. 0-6 KM BULK SHEAR VALUES INCREASE FROM AROUND 25 KTS
LATE THIS MORNING TO 35 TO 40 KTS LATE AFTERNOON INTO THE EVENING
HOURS. THE NAM CONTINUES TO BUILD STRONG INSTABILITY THIS
AFTERNOON WITH 0-3 KM MUCAPE VALUES CLIMBING TO AROUND 3000 J/KG.
THIS WOULD BE IF DEWPOINTS WOULD CLIMB INTO THE UPPER 60S TO LOWER
70S AND SURFACE TEMPERATURES WARM INTO THE LOWER 80S. SURFACE
TEMPERATURES ARE FORECAST TO CLIMB INTO THE UPPER 70S TO THE LOWER
80S BUT DEWPOINTS WILL BE MUCH LESS...IN THE 62 TO 65 DEGREE
RANGE. THINKING 0-3KM MUCAPE VALUES IN THE 1200 TO 1700 J/KG RANGE
SEEM MORE REALISTIC. THE POTENTIAL EXIST FOR A FEW ROUNDS OF
SHOWERS AND STORMS ALONG THE PREFRONTAL TROUGH AND ANOTHER TONIGHT
AS THE UPPER TROUGH DIVES SOUTHEAST INTO THE REGION AND THE COLD
FRONT EDGES CLOSER TO THE FORECAST AREA. IF STORMS HOLD OFF UNTIL
MID TO LATE AFTERNOON...LARGE HAIL AND DAMAGING WINDS MAY OCCUR
WITH THE STRONGER STORMS. THE FRONT IS EXPECTED TO PUSH THROUGH
THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY MORNING TAKING
THE BULK OF THE INSTABILITY SOUTH OF THE AREA. HOWEVER...THE
TROUGH WILL MOVE IN ITS WAKE WITH SHOWER AND ISOLATED STORM
CHANCES PERSISTING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 357 AM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS WILL BE ONGOING FRIDAY MORNING...ESPECIALLY
ACROSS CENTRAL AND FAR SOUTHWEST WISCONSIN. THE UPPER LEVEL TROUGH
THEN DIVES INTO THE AREA LATE FRIDAY MORNING INTO FRIDAY AFTERNOON.
SCATTERED TO NUMEROUS SHOWERS WILL DEVELOP AS COLDER AIR ALOFT MOVES
INTO THE AREA. THE TROUGH WILL REMAIN OVER THE REGION FRIDAY NIGHT
INTO SATURDAY AS AN UNSEASONABLY COLD AIRMASS MOVES IN. 850 MB
TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE -2.0 TO -2.5
RANGE...SUGGESTING NEAR RECORD COOL TEMPERATURES FOR THIS TIME OF
YEAR. HIGH TEMPERATURES ON SATURDAY WILL STRUGGLE TO GET OUT OF THE
60S. IN FACT...IT APPEARS LA CROSSE MAY SEE A RECORD LOWEST HIGH
TEMPERATURE FOR THE DATE. LATEST FORECAST IS 68 DEGREES AT LA
CROSSE. THIS WOULD BREAK THE OLD RECORD OF 69 SET BACK IN 1981.
FORECAST MODELS SUGGEST THERE WILL BE ENOUGH INSTABILITY ON SATURDAY
AFTERNOON TO GENERATE SOME SHOWERS...MAINLY ALONG AND NORTH OF
INTERSTATE 94. THIS MAKES SENSE LOOKING AT FORECAST SOUNDINGS
SHOWING SOME WEAK CAPE DURING THE AFTERNOON HOURS. HAVE ADDED A
SLIGHT CHANCE OF SHOWERS OVER CENTRAL WISCONSIN TO ACCOUNT FOR THIS.
ANOTHER SHORTWAVE ROTATES INTO NORTHERN WISCONSIN SATURDAY
NIGHT...BRINGING ADDITIONAL CHANCES FOR SHOWERS OVER NORTH CENTRAL
WISCONSIN. FLOW ALOFT THEN FINALLY STARTS TO TRANSITION TO ZONAL
EARLY NEXT WEEK AS THE TROUGH PUSHES EAST OF THE REGION INTO THE
EASTERN GREAT LAKES. TEMPERATURES WILL RETURN TO MORE SEASONABLE
VALUES FOR NEXT WEEK WITH HIGH CLIMBING BACK INTO THE UPPER 70S TO
AROUND 80. SEVERAL EMBEDDED WAVES IN THE ZONAL FLOW WILL BRINGING
PERIODIC CHANCES FOR SHOWERS AND STORMS MAINLY MONDAY NIGHT
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 24 2013
WIDELY SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS EVENING OVER
CENTRAL MINNESOTA AND ARE DROPPING SOUTHEAST AHEAD OF A WEAK SHORT
WAVE TROUGH. THE 25.01Z HRRR WOULD SUGGEST THESE WOULD DISSIPATE
BEFORE REACHING THE AREA. HOWEVER...IR SATELLITE INDICATES THE
CLOUD TOPS ARE NOT SHOWING ANY SIGNS OF WARMING YET AND GIVEN THE
CURRENT MOVEMENT...THESE COULD IMPACT KRST BEFORE SUNRISE. HAVE
THROWN IN A VCSH STARTING AT 10Z TO INDICATE THIS ACTIVITY COULD
BE GETTING CLOSE TO THE AREA. AFTER THAT...STILL HAVE VERY LOW
CONFIDENCE ON HOW THURSDAY IS GOING TO PLAY OUT. THE 25.00Z NAM
DID NOT SHIFT MUCH FROM THE 24.18Z RUN...IF ANYTHING...IT MIGHT BE
EVEN A LITTLE WEAKER WITH THE FORCING SIGNALS. NOT MUCH MOISTURE
CONVERGENCE OR MOISTURE TRANSPORT IS SHOWN TO BE OCCUR ALONG OR
INTO EITHER THE PRE-FRONTAL TROUGH OF SURFACE FRONT. NOT A LOT OF
DYNAMIC FORCING IS INDICATED EITHER AS THE MAIN SHORT WAVE TROUGH
IN THE NORTHWEST FLOW ALOFT WILL STILL BE OVER FAR NORTHERN
MINNESOTA INTO SASKATCHEWAN AND WILL BE POSITIVELY TILTED WHILE
ANOTHER SHORT WAVE TROUGH WILL BE MOVING OUT OF THE DAKOTAS
TOWARD IOWA FROM THE ONGOING CONVECTION OVER MONTANA. HAVE
MAINTAIN THE PREVIOUS THINKING OF SOME CONVECTION GOING UP IN THE
LATE MORNING TO EARLY AFTERNOON ALONG THE PRE-FRONTAL TROUGH...WHICH
THE HRRR ALSO SHOWS OCCURRING. THIS SHOULD MOVE OUT DURING THE
AFTERNOON WITH A SHORT PERIOD OF RECOVERY BEFORE THE FRONT COMES
IN WITH SOME ADDITIONAL SCATTERED CONVECTION. THIS WILL LIKELY END
DURING THE MID TO LATE EVENING BUT WILL LET THE NEXT FORECAST
DETAIL THAT ASPECT. CONFIDENCE STILL REMAINS TOO LOW TO INCLUDE
ANYTHING OTHER THAN VCTS AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 PM CDT WED JUL 24 2013
.SHORT TERM...(TONIGHT AND THURSDAY)
ISSUED AT 328 PM CDT WED JUL 24 2013
MAIN FORECAST CONCERNS THIS PACKAGE...INCREASING SHRA/TSRA CHANCES
THRU THU AND SEVERE POTENTIAL WITH THEM.
DATA ANALYSIS AT 18Z HAD BROAD BUT GENERALLY WEAK AREA OF HIGH
PRESSURE ACROSS THE NORTH-CENTRAL CONUS...CENTERED OVER WI TO NEB.
A WEAK TROUGH OF LOW PRESSURE WAS LOCATED OVER EAST CENTRAL TO SOUTH
CENTRAL MN...IN RESPONSE TO A WEAK SHORTWAVE SEEN IN WV IMAGERY
DROPPING SOUTHEAST ACROSS MN. VIS IMAGERY SHOWED CUMULUS DEVELOPED
RAPIDLY ACROSS MUCH OF THE REGION LATE THIS MORNING...UNDER THE
COOL 850-700MB AIRMASS. CLOUDS AND SOME ISOLATED SPRINKLES THIS
MORNING HELPING KEEP TEMPS ON THE COOL SIDE TODAY...WITH MID DAY
READINGS ONLY IN THE LOW-MID 70S OVER MUCH OF MN/IA/WI.
24.12Z MODELS AGAIN LOOK TO HAVE INITIALIZED WELL...BUT FOR GFS ON
THE LOW SIDE WITH SFC DEW POINTS FROM ND/SD THRU MN/WI. SOLUTIONS
QUITE SIMILAR FOR TONIGHT/THU AND HAVE TRENDED BACK TO BEING A BIT
FASTER WITH THE FRONT APPROACHING THE AREA LATE THU. HOWEVER GFS
CONTINUES TO LAG THE CONSENSUS AT 00Z FRI. DPROG/DT OF 500MB HGTS
AT 24.12Z SHOWED THE MODEL RUNS OF 22.12Z AND 23.12Z VERIFIED WELL
ACROSS NOAM/EASTERN PAC. SOLUTION CONTINUE TO OFFER A TIGHTENING
CONSENSUS /AT LEAST AT 500MB/ AS A STRONGER SHORTWAVE DROPS THRU
THE NORTHWEST FLOW ALOFT TOWARD THE AREA TONIGHT/THU. TREND FAVORING
A COMPROMISE ON THE STRENGTH OF THE TROUGH BUT NOW FAVORING FASTER OF
EARLIER MODELS BY 00Z FRI. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED
MODELS GOOD WITH THE HIGH OVER THE REGION AND WEAK TROUGH OVER MN...
AND REASONABLE ENOUGH WITH SFC DEW POINTS OVER THE CENTRAL CONUS.
PER WV IMAGERY MODELS LOOK TO BE STRUGGLING A BIT WITH WEAK SHORTWAVE
RIPPLES IN THE NORTHWEST FLOW FROM SASKAT/MAN TO WI BUT LOOKED
REASONABLE WITH FEATURES UPSTREAM OVER WESTERN CAN TO IMPACT THE
AREA THU/THU NIGHT. NO CLEAR MODEL FAVORITE AND WITH THE TREND
TOWARD A COMMON CONSENSUS...FAVORED THE CONSENSUS. SHORT TERM FCST
CONFIDENCE REMAINS GENERALLY GOOD THIS CYCLE.
IN THE SHORT TERM...QUESTION REMAINS WILL WEAK 925-850MB WARM/
MOISTURE ADVECTION ALONG WITH SOME ISENTROPIC LIFT/WEAK INSTABILITY
BE ENOUGH FOR ISOLATED SHRA/TSRA LATE THIS AFTERNOON/EARLY THIS
EVENING. SHORT TERM FORECASTER ADDED SOME SPRINKLES TO THE NORTHWEST
HALF OF THE FCST AREA FOR THE REST OF THIS AFTERNOON. WILL LEAVE THIS
EVENING DRY FOR NOW AS APPEARS ANY ACTIVITY WILL BE STRONGLY DIURNAL.
MAIN AXIS OF MOISTURE/MOISTURE TRANSPORT/ INSTABILITY REMAINS WEST/
NORTH OF THE FCST AREA TONIGHT...CLOSER TO THE DEVELOPING/APPROACHING
SFC TROUGH/FRONT. LEFT OVERNIGHT PORTION OF THE FCST DRY.
EVEN THOUGH MODELS ARE QUITE SIMILAR ALOFT...PLENTY OF MODEL DETAIL
DIFFERENCES IN THE LOWER/SFC LEVELS AS THE TROUGH/FRONT APPROACHES
ON THU. CONSENSUS HAS PW VALUES INCREASING INTO THE 1.5 TO 1.75 INCH
RANGE AHEAD OF THE FRONT ON THU. MU CAPE VALUES BUILD INTO THE 1.5
TO 2.5K J/KG RANGE BY MID-DAY THU. QUESTION IS HOW QUICKLY
CONVECTION FIRES ON THU. SOUNDINGS SHOWING LITTLE CAPPING BY MID-
DAY AND WITH APPROACH OF THE SHORTWAVE/FALLING HGTS/DIVERGENCE
ALOFT...CONVECTION MAY FIRE BY LATE MORNING JUST NORTHWEST OF THE
FCST AREA...THEN SPREAD INTO THE AREA DURING THE EARLY AFTERNOON.
DEBRIS CLOUDS WOULD QUICKLY LIMIT ADDITIONAL WARMING/
DESTABILIZATION...WITH ANY SEVERE THREAT BEING SHORT-LIVED/
LIMITED. LATER CONVECTIVE DEVELOPMENT CLOSER TO THE APPROACHING
FRONT WOULD ALLOW FOR MORE MOISTURE/INSTABILITY TO MOVE INTO THE
AREA...WITH MORE OF A SEVERE THREAT LATER IN THE AFTERNOON/EARLY
EVENING AS THE CONVECTION MOVES INTO THE FCST AREA. SEE SWODY2 FOR
MORE DETAILS OF THE SEVERE THREAT. WOULD EXPECT CONVECTIVE
INITIATION TO BE TIED MORE TO THE FRONT...THEN MOVE INTO THE AREA
DURING THE MID/LATE AFTERNOON HOURS. LEFT SHRA/TSRA CHANCES THRU
THU MORNING QUITE LOW. THEN RAISED THEM THRU THE AFTERNOON...INTO
THE 50-70 PERCENT RANGE BY LATE AFTERNOON ACROSS THE NORTHWEST
HALF OF THE FCST AREA. USED A MODEL/ENSEMBLE CONSENSUS FOR LOWS/
HIGHS TONIGHT/THU...THOUGH CONCERNED IF CONVECTION FIRES EARLY...
THU MAY BE TOO WARM UNDER PLENTY OF CLOUDS AND SCT SHRA/TSRA DURING
THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM CDT WED JUL 24 2013
FORECAST CONCERNS IN THE THU NIGHT THRU SAT NIGHT PERIOD INCLUDE
SHRA/TSRA CHANCES THU NIGHT/FRI WITH THE TROUGH/FRONTAL
PASSAGE...THEN COOL TEMPERATURES FRI NIGHT THRU SAT NIGHT.
24.12Z MODELS REMAIN VERY SIMILAR THU NIGHT/FRI AS THE MAIN
SHORTWAVE DROPS ACROSS THE AREA. MODELS THEN BEGIN TO DIVERGE WITH
WHAT HAPPENS/WHERE THE MID LEVEL LOW ENDS UP BY LATE SAT/SAT NIGHT.
TREND OF THE MORE CONSISTENT AND VERY SIMILAR GFS/ECMWF RUNS IS
TOWARD A MORE SOUTHWEST POSITION OF THE MID LEVEL LOW BY 00Z SUNDAY.
FAVORED A MODEL/ENSEMBLE CONSENSUS WEIGHTED TOWARD THE GFS/ECMWF FOR
THU NIGHT THRU SAT NIGHT...WITH AVERAGE TO GOOD FCST CONFIDENCE.
SFC-700MB TROUGH/FRONT SLIDES INTO/ACROSS THE AREA THU NIGHT/FRI
MORNING. MODEST LOWER LEVEL THERMODYNAMIC AND UPPER LEVEL DYNAMIC
FORCING/LIFT TO MOVE ACROSS THE AREA THU NIGHT. FAVORING A SCENARIO
WITH BULK OF THE CONVECTION ACCOMPANYING THE SFC-850MB FRONT/TROUGH
RAISED SHRA/TSRA CHANCES THU NIGHT INTO THE 70-80 PERCENT RANGE AND
ADDED SOME TIMING AS THE FRONT MOVES ACROSS THE FCST AREA. WITH THE
CONSENSUS NOW TOWARD A FASTER FRONTAL PASSAGE...TRENDED PRECIP
CHANCES TO 30 PERCENT OR LESS BY FRI AFTERNOON. WITH THE LOW LEVEL
COLD ADVECTION/STABILIZATION BY FRI AFTERNOON...ONLY CARRIED
MENTION OF SHRA AFTER 18Z. MDT/STRONG LOW LEVEL COLD ADVECTION
SPREADS ACROSS THE AREA FRI/FRI NIGHT. DRIER SFC-700MB AIR TRIES TO
WRAP ACROSS THE AREA BEHIND THE SFC-500MB LOW BUT BUT SOME
DEFORMATION BAND MOISTURE MAY WRAP AROUND THE LOW AND ACROSS THE
AREA UNDER THE COOL TEMPS AND CYCLONIC FLOW ALOFT. THIS MOISTURE/
CLOUDS WILL BATTLE THE SUBSIDENCE IN THE WAKE OF THE LOW. DID
INCREASE CLOUD COVER OVER AT LEAST THE NORTHEAST HALF OF THE FCST
AREA FOR LATE FRI/FRI NIGHT. CLOUDS/MODEST NORTHWEST WINDS ON FRI
WILL KEEP HIGHS FROM RISING MUCH. NORTHWEST GRADIENT WINDS OF 5-
10KTS AND POTENTIAL FOR CLOUD COVER WILL KEEP LOWS FROM FALLING OFF
TOO FAR FRI NIGHT. CONTINUED LOW LEVEL DRYING INDICATED FOR SAT/SAT
NIGHT AS THE LOW MOVES AWAY AND SFC-850MB HIGH PRESSURE BUILDS INTO
THE REGION. BY 00Z SUN...850MB TEMPS STILL PROGGED TO BE SOME 1.5
TO 2 STANDARD DEVIATIONS BELOW NORMAL. FRI THRU SAT NIGHT/SUN
MORNING LOOKING TO BE A COOL...AUTUMN LIKE COUPLE DAYS. TRENDED
HIGHS/LOWS FOR FRI THRU SAT NIGHT TOWARD COOLER OF GUIDANCE VALUES.
MEDIUM RANGE MODEL RUNS OF 24.00Z IN DECENT AGREEMENT WITH EACH
OTHER AND THEIR PREVIOUS RUNS ON SUNDAY. TREND FAVORS SLOWER/
FURTHER SOUTHWEST OF EARLIER MODELS WITH THE MID LEVEL LOW NORTH OF
LK SUPERIOR. BY MONDAY SOLUTIONS DIVERGE WITH HOW QUICKLY THIS LOW
LIFTS NORTHEAST AND GIVES UP ITS INFLUENCE ON THE REGION. THESE
DIFFERENCES LEAD TO BIGGER DIFFERENCES BY TUE AS SHORTWAVES MOVE
EAST THRU THE MAIN BELT OF WESTERLIES ACROSS SOUTHERN CAN/NORTHERN
CONUS. BY TUE/WED...GFS/ECMWF WERE 180 DEGREES OUT OF PHASE WITH
TIMING OF STRONGER WAVES THRU THE FLOW BUT 24.12Z GFS HAS TRENDED
MORE SIMILAR TO THE ECMWF. GIVEN MODELS LOOKING TO DEAL WITH AN
ACTIVE QUASI-ZONAL FLOW NEXT WEEK...THE LESSER RUN-TO-RUN
CONSISTENCY SEEN IN THE DAY 5-6-7 PERIOD NOT SURPRISING. DAY 4-7
FCST CONFIDENCE AVERAGE AT BEST THIS CYCLE...AND WITHOUT A
PREFERRED MODEL WILL SIDE NEAR THE MODEL/ENSEMBLE CONSENSUS.
SUNDAY CONTINUES TO LOOK LIKE A DRY/QUIET...SEASONABLY COOL DAY AS
THE CAN HIGH PRESSURE CENTERED OVER THE REGION IN THE MORNING SLIPS
SOUTHEAST THRU THE DAY. WITH THE MODELS THEN VARYING ON TIMING OF
STRONGER...MORE TRACKABLE SHORTWAVES THRU THE FLOW...FCST GETS
MUDDY FOR EARLY NEXT WEEK. THERE WILL BE DRY PERIODS/DAYS IN THE
MON-WED PERIODS BUT WHICH THESE WILL BE IN NEARLY IMPOSSIBLE TO
DETERMINE WITH THE VARIETY OF SOLUTIONS AMONG THE RECENT MODEL
SETS. SMALL SHRA/TSRA CHANCES FOR MUCH OF THE MON-WED PERIOD
REASONABLE FOR NOW UNTIL THE DETAILS CAN BE SORTED OUT. AFTER THE
COOL WEEKEND...IT DOES APPEAR TEMPS WILL WARM BACK TO NEAR NORMAL
BY THE MIDDLE OF NEXT WEEK AS THE FLOW TRANSITIONS TO WESTERLY.
MODEL CONSENSUS HIGHS/ LOWS FOR THE DAY 4-7 PERIOD LOOK WELL
TRENDED AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 24 2013
WIDELY SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS EVENING OVER
CENTRAL MINNESOTA AND ARE DROPPING SOUTHEAST AHEAD OF A WEAK SHORT
WAVE TROUGH. THE 25.01Z HRRR WOULD SUGGEST THESE WOULD DISSIPATE
BEFORE REACHING THE AREA. HOWEVER...IR SATELLITE INDICATES THE
CLOUD TOPS ARE NOT SHOWING ANY SIGNS OF WARMING YET AND GIVEN THE
CURRENT MOVEMENT...THESE COULD IMPACT KRST BEFORE SUNRISE. HAVE
THROWN IN A VCSH STARTING AT 10Z TO INDICATE THIS ACTIVITY COULD
BE GETTING CLOSE TO THE AREA. AFTER THAT...STILL HAVE VERY LOW
CONFIDENCE ON HOW THURSDAY IS GOING TO PLAY OUT. THE 25.00Z NAM
DID NOT SHIFT MUCH FROM THE 24.18Z RUN...IF ANYTHING...IT MIGHT BE
EVEN A LITTLE WEAKER WITH THE FORCING SIGNALS. NOT MUCH MOISTURE
CONVERGENCE OR MOISTURE TRANSPORT IS SHOWN TO BE OCCUR ALONG OR
INTO EITHER THE PRE-FRONTAL TROUGH OF SURFACE FRONT. NOT A LOT OF
DYNAMIC FORCING IS INDICATED EITHER AS THE MAIN SHORT WAVE TROUGH
IN THE NORTHWEST FLOW ALOFT WILL STILL BE OVER FAR NORTHERN
MINNESOTA INTO SASKATCHEWAN AND WILL BE POSITIVELY TILTED WHILE
ANOTHER SHORT WAVE TROUGH WILL BE MOVING OUT OF THE DAKOTAS
TOWARD IOWA FROM THE ONGOING CONVECTION OVER MONTANA. HAVE
MAINTAIN THE PREVIOUS THINKING OF SOME CONVECTION GOING UP IN THE
LATE MORNING TO EARLY AFTERNOON ALONG THE PRE-FRONTAL TROUGH...WHICH
THE HRRR ALSO SHOWS OCCURRING. THIS SHOULD MOVE OUT DURING THE
AFTERNOON WITH A SHORT PERIOD OF RECOVERY BEFORE THE FRONT COMES
IN WITH SOME ADDITIONAL SCATTERED CONVECTION. THIS WILL LIKELY END
DURING THE MID TO LATE EVENING BUT WILL LET THE NEXT FORECAST
DETAIL THAT ASPECT. CONFIDENCE STILL REMAINS TOO LOW TO INCLUDE
ANYTHING OTHER THAN VCTS AT THIS POINT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS TUCSON AZ
825 AM MST THU JUL 25 2013
.SYNOPSIS...A DISTURBANCE ALOFT ACROSS THE AREA WILL ENHANCE
THUNDERSTORM COVERAGE AND INTENSITY ACROSS MOST OF THE AREA TODAY.
SOME STORMS WILL GENERATE HEAVY RAINFALL. OTHERWISE...PLENTY OF
MOISTURE ACROSS THE REGION TO PROVIDE A CHANCE OF MAINLY AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND. A DECREASE
IN MOISTURE MAY LEAD TO LESS THUNDERSTORM ACTIVITY EARLY NEXT WEEK.
&&
.DISCUSSION...THE 12Z KTWC SOUNDING IS DEPICTING A VERY MOIST AND
UNSTABLE ATMOSPHERE. PWAT OF 1.96" IS IN THE 99TH PERCENTILE AND
ABOUT 160 PERCENT OF NORMAL FOR THIS TIME OF YEAR. MEANWHILE...THERE
IS CONSIDERABLY MORE MID LEVEL COOLING COMPARED TO 24 HOURS AGO WITH
THE STUBBORN INVERSION AT ABOUT 500 MB GONE. MODIFIED SOUNDING WITH
T=95 AND TD=61 YIELDS ABOUT 1800 J/KG OF CAPE. THE STEERING FLOW IS
GENERALLY FROM THE EAST AT ABOUT 10 MPH. CURRENT SATELLITE AND RADAR
IMAGERY DEPICT CONVECTIVE SHOWERS MAINLY OVER THE CENTRAL AND
WESTERN DESERTS PUSHING WEST WITH PARTLY TO MOSTLY CLOUDY SKIES
MAINLY FROM DEBRIS CLOUDINESS FROM TUCSON EASTWARD. THERE IS A WELL
DEFINED SHEAR AXIS/DEFORMATION ZONE IN THE MID TO UPPER LEVELS LYING
RIGHT ACROSS THE CENTER OF THE FORECAST AREA TODAY WITH THE REMNANTS
OF AN INVERTED TROUGH. THE BIG QUESTION FOR TODAY IS HOW MUCH
CLEARING WILL WE SEE TO GENERATE SUSTAINED CONVECTION.
AFTER REVIEWING LATEST GUIDANCE...TEND TO FAVOR THE HRRR WHICH IS
HANDLING THE CURRENT CLOUD COVERAGE REALLY WELL ALONG WITH THE LIGHT
SHOWERS WEST OF TUCSON. THE HRRR IS MOST ORGANIZED WITH CONVECTION
THIS AFTERNOON AND EVENING ALONG WITH THE 12Z NAM FROM CENTRAL PIMA
COUNTY EASTWARD. MEANWHILE...THE EARLY 06Z UOFA WRF-GFS AND 12Z
WRF-NAM HAVE CLEARED THINGS OUT TOO QUICKLY. WITH THAT SAID...HAVE
GONE AHEAD AND RAISED POPS AREAWIDE FOR THIS AFTERNOON AND THIS
EVENING. WE THINK THE BEST CHANCE FOR HEAVIEST RAINFALL WILL BE FROM
THE TUCSON AREA EASTWARD. AS THE MORNING PROGRESSES AND SHOULD SKIES
CLEAR AND CONFIDENCE INCREASE...WILL CONSIDER A SHORTER FUSE FLASH
FLOOD WATCH.
&&
.AVIATION...SCT SHRA / ISOLD TSRA THRU FRIDAY MORNING OR 26/17Z.
MVFR CIGS/VSBYS WITH WIND GUSTS APPROACHING 45 KTS WITH THE
STRONGEST TSRA. TSRA COVERAGE INCREASING AFTER 26/17Z.
OTHERWISE...CLOUD DECKS MAINLY 6-10K FT AGL AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU THURSDAY EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ENHANCED MOISTURE WILL PROVIDE A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. OTHERWISE... THERE
WILL BE ENOUGH MOISTURE FOR SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS TO PREVAIL INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
GL
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 AM MDT THU JUL 25 2013
.UPDATE...COMPLICATED WEATHER PATTERN TODAY WILL LEAD TO A LOW
CONFIDENCE FORECAST. A WAVE MOVING ACROSS EASTERN COLORADO AT THIS
TIME IS BRINGING RAIN SHOWERS AND CLOUDS TO NORTHEAST COLORADO. THIS
HAS SLOWED WARMING. A COLD FRONT WILL ENTER NORTHERN COLORADO SOON.
WINDS IN SOUTHERN WYOMING BEHIND THE FRONT ARE GUSTING TO 30 MPH
BEHIND THE FRONT. THIS WILL PUSH THROUGH THE AREA DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS. A SECOND WAVE OVER WYOMING AND
UTAH WILL PROGRESS EASTWARD TODAY AND TRIGGER SHOWERS AND STORMS
OVER THE HIGHER TERRAIN.
TEMPERATURES AT 700MB HAVE DECREASED. THE 12Z SOUNDING INDICATED A
CONVECTIVE TEMPERATURE OF 82 DEGREES. BIGGEST QUESTION IS...WILL THE
URBAN CORRIDOR AND EASTERN PLAINS BE TOO CAPPED FOR CONVECTION.
THE COOLER AIR SLIDING SOUTH MAY KEEP THE AREA FROM REACHING ITS
CONVECTIVE TEMPERATURE. HOWEVER THE FRONT MAY PRODUCE ENOUGH LIFT
TO TRIGGER CONVECTION. NOT SURE HOW THIS WILL PAN OUT AND WILL
KEEP SCATTERED POPS IN THE FORECAST. WILL LOWER TEMPERATURES A FEW
DEGREES BECAUSE OF THE CLOUD COVER AND COLD FRONT APPROACHING FROM
THE NORTH.
&&
.AVIATION...WINDS WILL BECOME NORTHERLY AS A COLD FRONT PUSHES
THROUGH THE AREA AROUND 18Z. WILL BE ANOTHER CHANCE FOR
THUNDERSTORMS THIS AFTERNOON AND EVENING. AN UPPER LEVEL SYSTEM
WILL MOVE OVER THE MOIST AIRMASS IN PLACE AND TRIGGER SCATTERED
THUNDERSTORMS. GUSTY OUTFLOW WINDS AND HEAVY RAIN WILL BE THE
BIGGEST CONCERNS. CHANCE FOR STORMS WILL END DURING THE EARLY
EVENING HOURS...BY 03Z. WINDS WILL SETTLE SOUTHERLY AROUND
MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 335 AM MDT THU JUL 25 2013/
SHORT TERM...A DISTURBANCE IS CURRENTLY OVER THE MTNS EARLY THIS
MORNING AND SHOULD EXIT NERN COLORADO BY LATE MORNING. AS THIS
FEATURE MOVES ACROSS THERE WILL BE A FEW SHOWERS AND POSSIBLY A
TSTM THRU THE MORNING HOURS.
FOR THIS AFTN QUITE A BIT OF SUBTROPICAL MOISTURE WILL REMAIN OVER
THE AREA WITH PRECIPITABLE WATER VALUES AROUND AN INCH. WOULD
EXPECT TSTMS TO REDEVELOP OVER THE HIGHER TERRAIN BY EARLY AFTN.
MEANWHILE OVER NERN CO A COOL FNT WILL BE NR THE WYOMING BORDER
AROUND 18Z AND THEN MOVE ACROSS THE PLAINS THRU THE AFTN. NOT SURE
HOW THINGS ARE GOING TO EVOLVE WITH THIS FNT AS FAR AS TSTM
DEVELOPMENT GOES OVER THE PLAINS. ITS POSSIBLY ACTIVITY COULD END
UP FOCUSING CLOSER TO THE FOOTHILLS AND OVER THE PALMER DIVIDE
WITH LIMITED ACTIVITY OVER THE PLAINS THRU THE AFTN. SHORT RANGE
MODELS ARE NOT MUCH HELP AS FAR AS DEFINING BEST AREAS FOR TSTMS
SO WILL JUST KEEP POPS IN THE CHC CATEGORY. OVERALL INSTABILITY
DOES NOT LOOK AS UNSTABLE AS WED WITH THE MID LVL FLOW SOMEWHAT
WEAKER SO SVR THREAT LOOKS LOW. STORMS WILL BE SLOWER MOVING WHICH
COULD LEAD TO HEAVY RAINFALL IN SOME AREAS. AS FAR AS TEMPS WILL
KEEP HIGHS MAINLY IN THE LOWER TO MID 80S OVER NERN CO.
FOR TONIGHT WITH THE FLOW OF SUBTROPICAL MOISTURE CONTINUING IN
THE MTNS SHOWERS AND A FEW STORMS COULD LINGER OVERNIGHT SO WILL
KEEP IN SOME LOW POPS. OVER NERN CO IT APPEARS TSTM ACTIVITY
SHOULD GRADUALLY END IN THE EARLY EVENING HOURS.
LONG TERM...THE NEXT WEEK CONTINUES TO LOOK ACTIVE AND WET ACROSS
THE FORECAST AREA. AN ELONGATED UPPER LEVEL HIGH PRESSURE RIDGE
WILL EXTEND ACROSS THE SOUTHERN TIER OF THE COUNTRY WITH MONSOONAL
MOISTURE ADVECTING ACROSS ARIZONA AND NEW MEXICO INTO UTAH AND
COLORADO. DAILY PRECIPITATION DISTRIBUTIONS ARE GOING TO DEPEND ON
MESOSCALE FEATURES LIKE STRENGTH OF UPSLOPE FLOW AND THE PRESENCE
OF A DENVER CYCLONE...AS WELL AS THE LOCATION OF PASSING WEAK
UPPER LEVEL JET STREAMS. THE LATEST RUN OF THE ECMWF POINTS TOWARD
SUNDAY AFTERNOON BEING A PARTICULARLY ACTIVE DAY WITH DECENT
SOUTHEASTERLY LOW LEVEL FLOW ACROSS EASTERN COLORADO AND WEAK
WESTERLY FLOW ALOFT. THE FEED OF SUB-TROPICAL MOISTURE LOOKS LIKE
IT WILL REMAIN IN PLACE THROUGH AT LEAST NEXT TUESDAY...SO THE
FORECAST WILL CONTINUE TO MENTION THE CHANCE OF THUNDERSTORMS EACH
DAY. ALONG WITH THE PERSISTENT CHANCES OF PRECIPITATION...
TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL BUT STILL
WARM ENOUGH TO PRODUCE THE INSTABILITY NECESSARY FOR DAILY
CONVECTION TO DEVELOP. PERIODS OF NOCTURNAL SHOWERS CAN ALSO NOT
BE RULED OUT LIKE WE ARE SEEING THIS MORNING.
AVIATION...MAY SEE A FEW -SHRA THIS MORNING AS DISTURBANCE MOVES
ACROSS BUT CEILINGS SHOULD STAY ABV 8000 FT. DO NOT HAVE A GOOD
FEEL FOR WINDS THIS MORNING HOWEVER WILL KEEP WINDS LIGHT NWLY
THRU MID MORNING AND THEN HAVE THEM BECOME MORE NNE BY EARLY AFTN
AS A FNT MOVES ACROSS. THE LATEST HRRR AND RAP INDICATES THERE
WOULD A CHC OF TSTMS IN THE 21Z-00Z TIME PERIOD SO WILL PUT IN A
PROP GROUP FOR -TSRA. FOR THIS EVENING TSTM THREAT SHOULD END BY
01Z WITH WINDS BECOMING DRAINAGE BY MIDNIGHT.
HYDROLOGY...THERE WILL BE SCATTERED THUNDERSTORMS THIS AFTERNOON
WITH SOME LOCALLY HEAVY RAIN POSSIBLE. THE STRONGER STORMS COULD
PRODUCE RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES WHICH COULD
LEAD TO SOME FLOODING ISSUES IF THEY TRACK ACROSS THE BURN SCARS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....DANKERS
UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
927 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. THIS LOW
MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT...AND INTO THE CANADIAN
MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO THE
LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER COLD
FRONT WILL BE APPROACHING FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...WITH JUST ISOLATED THUNDER. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO THE NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL
ALLOW FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER
LEVEL CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY
AND SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST
FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY AND
SUNDAY NIGHT. A RETURNING DRYING TREND FOR MONDAY FROM WEST TO
EAST WITH SLIGHT CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
BASED ON THE PREVIOUS HIGH TIDE CYCLE...A LOWERING ASTRONOMICAL
TIDE...AND WIND FORECAST...NOT EXPECTING MINOR COASTAL FLOODING
THIS AFTERNOON AND TONIGHT...BUT WILL NEED TO KEEP AN EYE ON THIS
AS BENCHMARKS PROBABLY WILL NOT BE MISSED BY MUCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
806 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO THE NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL
ALLOW FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER
LEVEL CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY
AND SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE NORTHEAST
FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY AND
SUNDAY NIGHT. A RETURNING DRYING TREND FOR MONDAY FROM WEST TO
EAST WITH SLIGHT CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
748 AM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY EAST OF THE AREA WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY AS A WAVE OF LOW PRESSURE MOVES ALONG IT. LOW
PRESSURE MOVES INTO NORTHERN NEW ENGLAND FRIDAY NIGHT AND INTO THE
CANADIAN MARITIMES FOR THE WEEKEND. WEAK HIGH PRESSURE BUILDS INTO
THE LOCAL REGION FRIDAY NIGHT AND SATURDAY. BY SUNDAY...ANOTHER
COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS MOVES ACROSS
EARLY ON MONDAY WITH A RETURN OF HIGH PRESSURE
THEREAFTER...BUILDING IN FROM THE WEST. THIS WILL EVENTUALLY
WEAKEN BY MID NEXT WEEK...WITH WEAK LOW PRESSURE BEGINNING TO
APPROACH FROM THE SOUTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DOPPLER RADAR REFLECTIVITY SHOWS SOME SHOWER ACTIVITY ACROSS PARTS
OF LONG ISLAND AND SOUTHERN CONNECTICUT. POPS WERE LEFT THE SAME
AS BEFORE. STILL EXPECT RADAR RETURNS TO PICK UP MORE WITH MORE
SHOWERS FILLING IN AS THE MORNING PROGRESSES. TEMPS AND DEWPOINTS
WERE OFF BY A FEW DEGREES SO THEY WERE ADJUSTED BUT OTHERWISE NO
OTHER REMARKABLE CHANGES MADE WITH FORECAST OVERALL STILL ON TRACK.
TOUGHEST PART OF THE FORECAST TODAY WILL BE WHERE THE WESTERN EDGE
OF MEASURABLE PRECIP WILL BE. THE LAST FEW RUNS OF THE HRRR HAS
BEEN HINTING AT ACTIVITY EXPANDING INTO THE NYC AREA WHICH HAS
SUPPORT FROM THE GFS AND EC. THE NAM KEEPS MOST OF THE AREA DRY
TODAY...BUT THINK THIS IS TOO OPTIMISTIC. HAVE EXPANDED POPS
WESTWARD AND INCREASED THEM FROM THE PREVIOUS
FORECAST...ESPECIALLY FROM NYC AND POINTS E. MEAGER INSTABILITY
TODAY...SO NO THUNDER IN FORECAST. PWATS GENERALLY BETWEEN 1 1/4
AND 1 1/2 INCHES TODAY...SO WHILE MODERATE RAIN CAN BE EXPECTED AT
TIMES...THE POTENTIAL FOR FLOODING RAINS IS LOW.
INCREASING NE WINDS TODAY AS THE PRESSURE GRADIENT TIGHTENS. GUSTS
UP TO 25 MPH ARE EXPECTED.
LARGE DIFFERENCES IN TEMP GUIDANCE TODAY ACROSS WESTERN LOCATIONS.
THINK THE METS ARE TOO COOL AND THE MAVS A TAD TOO WARM
CONSIDERING THE EXPECTATION OF A MOSTLY CLOUDY AND SCT SHOWERY
DAY. THEREFORE HAVE USED A BLEND OF THE MOS...WHOSE OUTPUT SEEMED
REASONABLE.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN BEACHES
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
CHANCES FOR RAIN WILL CONTINUE TONIGHT AS A WAVE OF LOW PRESSURE
TRACKS ALONG A STALLED FRONTAL BOUNDARY JUST EAST OF THE AREA.
HIGHEST LIKELIHOOD FOR RAIN IS ACROSS EASTERN LONG ISLAND AND
SOUTHEAST CT. MODELS ARE IN DECENT AGREEMENT WITH THE TIMING AND
LOCATION OF THE LOW TRACK...WITH THE EXCEPTION OF THE GFS AND CMC WHO
INCREASE IN FORWARD SPEED MUCH FASTER THAN THE REMAINING GUIDANCE
ON FRIDAY. FOR THIS REASON...IT HAS BEEN DISCOUNTED FROM THE
FORECAST FOR THIS PERIOD. COULD BE SOME LINGERING SHOWERS ACROSS
THE EASTERN ZONES ON FRIDAY...BUT THE BULK OF THE PRECIP IS
FORECAST TO REMAIN E OF THE AREA AS THE LOW PASSES BY AND LIFTS
INTO THE GULF OF MAINE BY EVENING.
TEMPS TONIGHT AND TOMORROW SHOULD BE NEAR NORMAL LEVELS. GUIDANCE
WAS CLOSE AND A BLEND WAS ACCEPTED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LIFTING TROUGH TO NORTHEAST FRIDAY NIGHT INTO WEEKEND WILL ALLOW
FOR A STEADY TREND IN GEOPOTENTIAL TENDENCY. LARGE UPPER LEVEL
CLOSED LOW IN GREAT LAKES MOVES INTO THE NORTHEAST SUNDAY AND
SUNDAY NIGHT. THIS WILL THEN LIFT INTO SOUTHEAST CANADA AND
FLATTEN WITH WITH LESS AMPLITUDES IN LONGWAVE TROUGH IN THE
NORTHEAST FOR EARLY TO MID NEXT WEEK.
DRY WEATHER FOR FRIDAY NIGHT AND THEN AN INCREASING CHANCE OF
SHOWERS WITH PERHAPS SOME ISOLATED THUNDERSTORMS SATURDAY AND
SATURDAY NIGHT. THESE INCREASE IN PROBABILITY FOR SUNDAY. A
RETURNING DRYING TREND FOR MONDAY FROM WEST TO EAST WITH SLIGHT
CHANCES OF CONVECTION TOWARDS MIDWEEK.
THERE WILL BE EXTRA SYNOPTIC FORCING SUNDAY WITH RIGHT REAR QUAD OF
100-115 KT JET ENHANCING LIFT. WITH CAPE EXCEEDING 1000 J/KG ACROSS
THE REGION...LOOKING AT SHOWERS AND THUNDERSTORMS WHICH FROM MODEL
QPF FIELDS...ARE FOCUSED MORE IN THE WESTERN SECTIONS AND EASTERN
SECTIONS HAVE LESS QPF. MODELS ARE CONVEYING 0-6KM SHEAR OF AROUND
30 KT AND PWATS ARE AROUND 1.75 TO 2 INCHES. THEREFORE...CONVECTION
COULD BE STRONG WITH HEAVY RAIN POSSIBLE.
REGARDING TEMPERATURES...THEY WILL BE NEAR NORMAL VALUES FOR MUCH OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE WILL RIDE ALONG A STALLED FRONT SOUTH OF THE AREA TODAY.
EXPECT LOW END VFR OR HIGH END MVFR (CIGS AROUND 3 KFT) THIS
MORNING...AND THESE CEILINGS MAY LINGER MOST OF THE DAY.
SHOWERS WILL NEED TO BE WATCHED TODAY...BUT MAIN AREA LOOKS TO
REMAIN JUST EAST OF NYC TERMINALS THIS AFTERNOON AND INTO TONIGHT.
BETTER CHANCE FOR ORGANIZED SHOWERS OVER KISP AND KGON.
AGAIN...THIS WILL NEED TO BE MONITORED.
CEILINGS SHOULD RETURN TO VFR OR 4 TO 5 KFT SOMETIME TONIGHT AS
THE BULK OF THE SHOWER ACTIVITY MOVES EAST.
NORTHEAST WINDS TODAY REMAIN 10 TO 15 KTS WITH GUSTS AT TIMES 15
TO 20 KTS. THESE WINDS CONTINUE INTO TONIGHT...LIGHTEN SOMEWHAT
AND BACK TO THE NORTH AFTER MIDNIGHT.
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: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KLGA FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS MAY IMPACT THE AIRPORT FROM TIME TO TIME...AND WILL
NEED TO BE MONITORED.
KTEB FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KHPN FCSTER COMMENTS: CEILINGS COULD BOUNCE BETWEEN MVFR AND VFR
TODAY. SHOWERS SHOULD REMAIN ISOLATED OR IN THE VICINITY.
KISP FCSTER COMMENTS: CEILINGS SHOULD REMAIN BETWEEN 2 AND 3 KFT
TODAY...AND SHOWERS ARE EXPECTED TO IMPACT THE AIRPORT THIS
AFTERNOON.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SATURDAY NIGHT...MAINLY VFR...WITH SUB-VFR POSSIBLE IN
ISOLD-SCT SHRA. ALSO A SLIGHT CHANCE OF TSRA SATURDAY AFTERNOON/EVENING.
.SUNDAY-MONDAY...SUB-VFR POSSIBLE IN SCT SHRA/TSTMS.
&&
.MARINE...
NE WINDS WILL INCREASE TO AROUND 20 KT ON THE OCEAN WATERS EAST OF
FIRE ISLAND INLET TODAY DUE TO AN INCREASING PRESSURE GRADIENT.
WOULD EXPECT 25-30 KT GUSTS FROM TIME TO TIME AS WELL...WITH SEAS
BUILDING TO 5 TO 6 FT. AS LOW PRESSURE TRACKS ALONG A STALLED
FRONTAL BOUNDARY PASSING NEAR THE 40N 70W BENCHMARK ON FRI...THESE
CONDITIONS ARE EXPECTED TO CONTINUE...THEREFORE HAVE EXTENDED THE
SCA THROUGH THIS TIME. FOR EASTERN LONG ISLAND SOUND AND BAYS AS
WELL AS OCEAN WEST OF FIRE ISLAND INLET...WIND GUSTS TO 25 KT WILL
BE OCCASIONAL.
FOR FRIDAY NIGHT THROUGH TUESDAY...WE START WITH SCA CONDITIONS
FOR SEAS...WHICH WILL CONTINUE FRIDAY NIGHT INTO THE DAYTIME HOURS
ON SATURDAY...MAINLY EAST OF FIRE ISLAND INLET. THESE SEAS WILL
GRADUALLY LOWER BELOW 5 FT ON SATURDAY FROM WEST TO EAST.
OTHERWISE...WINDS WILL REMAIN BELOW SCA CRITERIA WITH WEAK
PRESSURE GRADIENTS IN PLACE.
&&
.HYDROLOGY...
LESS THAN 1/10 OF AN INCH OF RAINFALL IS EXPECTED ACROSS
NYC...SOUTHWEST CT AND THE LOWER HUDSON VALLEY THROUGH
FRIDAY...WHILE BETWEEN 1/10 AND 1/3 IS EXPECTED IN SOUTHEAST CT
AND LONG ISLAND. NO FLOODING CONCERNS THROUGH THIS TIME.
HEAVY RAIN WITH SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
SUNDAY. HENCE...LOCALIZED POOR DRAINAGE AND URBAN FLOODING WILL BE
POSSIBLE. OTHERWISE...NO SIGNIFICANT WIDESPREAD PRECIPITATION
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WATERS LEVELS TOUCHED MINOR FLOOD BENCHMARKS LATE WED EVE/EARLY
THIS MORNING ON THE WESTERN SOUTH SHORE BAYS OF LONG ISLAND AND
CT COAST. HOWEVER...AS WINDS TURN TO A MORE FAVORABLE E-NE FETCH
ON THU AND OCEAN SEAS BUILD...MINOR COASTAL FLOODING COULD BE
POSSIBLE WITH THE HIGH TIDE CYCLE THU NIGHT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1023 AM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1013 AM CDT THU JUL 25 2013
THERE ARE QUESTIONS ON WHETHER OR NOT CONVECTION WILL BE SEEN IN
THE CWFA PRIOR TO EVENING. THE 12Z SOUNDING HAS A CONVECTIVE
TEMPERATURE IN THE UPPER 70S. HOWEVER...RAP AND OTHER MODEL TRENDS
SHOW THIS CLIMBING INTO THE 80S AS THE DAY PROGRESSES. THE LACK OF
ANY DIURNAL CU AT THIS POINT IN THE DAY INDICATES THAT THE TRIGGER
TEMPERATURE TO GENERATE THERMALS HAS YET TO BE ACHIEVED.
THE LATE MORNING AND EARLY AFTERNOON HOURS WILL REMAIN DRY ACROSS
THE AREA. THE QUESTION BECOMES LATE AFTERNOON DURING PEAK HEATING.
THE MCS AND LIFT TOOLS FROM THE ECMWF/UKMET/GEM INDICATE DRY
CONDITIONS LATE THIS AFTERNOON AND THROUGH SUNSET. THE WRF/GFS
HAVE CONVECTION INTO THE NORTHERN/WESTERN PARTS OF THE CWFA BY
LATE AFTERNOON AND OVER MOST OF THE AREA BY SUNSET. THE RAP KEEPS
MOST OF THE AREA DRY THROUGH LATE AFTERNOON BUT BRINGS IN
CONVECTION INTO THE WESTERN PARTS OF THE CWFA JUST PRIOR TO
EVENING.
SO...WILL GO WITH THE IDEA OF KEEPING NEARLY ALL OF THE CWFA DRY
THROUGH LATE AFTERNOON WITH POSSIBLY SOME CONVECTION NORTH OF HWY
20 BETWEEN KDBQ AND KALO JUST BEFORE EVENING. DURING THE EVENING
WILL GO WITH CONVECTION DEVELOPING/SPREADING SOUTH AND EAST ACROSS
THE CWFA. ..08..
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUL 25 2013
COOL AND QUIET CONDITIONS WERE FOUND ACROSS THE AREA EARLY THIS
MORNING AS HIGH PRESSURE...REACHING FROM THE GREAT LAKES
SOUTHEAST ACROSS IL AND MO...REMAINS IN CONTROL. TEMPERATURES WERE
IN THE 50S TO LOWER 60S WITH DEWPOINTS MAINLY IN THE LOWER 50S
UNDER MOSTLY CLEAR SKIES. MORE ACTIVE WEATHER WAS FOUND ACROSS THE
PLAINS...WHERE SHORTWAVES IN THE NW FLOW WERE INTERACTING WITH
GULF MOISTURE RETURN...RESULTING IN SEVERAL THUNDERSTORM
CLUSTERS. THE LOCAL FOCUS IS ON A SHORTWAVE EVIDENT ON WV IMAGES
JUST NW OF LAKE WINNIPEG THAT IS PROGGED TO TRAVEL SOUTHEAST INTO
THE EASTERN U.S. TROUGH...DIGGING INTO A CLOSED UPPER LOW OVER THE
GREAT LAKES BY FRIDAY. IN THE PROCESS...IT WILL SWEEP A COLD FRONT
THROUGH THE FORECAST AREA EARLY FRIDAY TRIGGERING WIDESPREAD
SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
MAIN FOCUS IS ON THUNDERSTORM CHANCES LATER TODAY THROUGH FRIDAY.
TODAY...THE SURFACE HIGH WILL CONTINUE TO MIGRATE EAST...ALLOWING A
LOW LEVEL RETURN FLOW AND WARM ADVECTION. THE GFS AND WRF/NAM APPEAR
TOO AGGRESSIVE WITH THIS LOW LEVEL MOISTURE RETURN...RESULTING IN
DEWPOINTS SHOWN REACHING THE UPPER 60S TO MID 70S BY AFTERNOON
OVER EASTERN IA. THIS THEN LEADS TO HIGHER CAPES AND A FASTER
ONSET OF THUNDERSTORMS INTO EASTERN IA WELL OUT AHEAD OF THE
SURFACE COLD FRONT THIS AFTERNOON. THE MORE REASONABLE ECMWF AND
GEM LOW LEVEL MOISTURE FIELDS KEEP THE THUNDERSTORMS WELL WEST
AND NW OF THE FORECAST AREA DURING THE DAY. WITH LIGHT WINDS AND
POSSIBLE OUTFLOW BOUNDARIES UNDER A DEVELOPING SLIGHTLY DIFLUENT
FLOW ALOFT AHEAD OF THE APPROACHING SHORTWAVE...CANNOT COMPLETELY RULE
OUT SHOWERS AND THUNDERSTORMS REACHING THE FAR NW BY LATE AFTERNOON
AND WILL CARRY LOW CHANCE POPS. WITH LIGHT SOUTH TO SOUTHEAST
WINDS AND WARM ADVECTION...HAVE KEPT HIGHS IN THE UPPER 70S TO
LOWER 80S. WILL ANTICIPATE INCREASING MID AND HIGH CLOUDS FROM
UPSTREAM CONVECTION TO PREVENT EVEN WARMER TEMPERATURES.
TONIGHT INTO FRIDAY...THE PRIMARY AXIS OF GULF MOISTURE AT 850 MB SPREADS
INTO THE FORECAST AREA UNDER AN INCREASINGLY DIFLUENT FLOW ALOFT.
MODELS CONTINUE TO DEPICT THE STRONGEST UPPER FORCING AHEAD OF THE
DEVELOPING UPPER LOW TO THE NORTH ACROSS MN INTO WI...BUT DECENT
QG FORCING IS SHOWN DEVELOPING INTO THE FORECAST AREA ALONG WITH
MODEST THETAE CONVERGENCE...ESPECIALLY FROM 12Z TO 18Z COINCIDING
WITH THE ADVANCING SURFACE COLD FRONT. THERE REMAINS SOME CONCERN
IN HOW A SEPARATE STRONG SHORTWAVE IN THE PLAINS AND RESULTING
MCS MAY AFFECT THE MOISTURE FEED FURTHER NORTH AND NORTHEAST...
WHICH MAY LIMIT THE STRENGTH AND SIZE OF THE PREFRONTAL MCS THAT
WILL BE FAVORED TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT
INTO FRIDAY MORNING. WILL THUS KEEP QPF AMOUNTS OF A FEW TENTHS TO
NEAR A HALF INCH OVER THE AREA WITH LIKELY POPS CENTERED FROM LATE
TONIGHT THROUGH FRIDAY MORNING. THIS TIMING WILL NOT BE FAVORABLE
FOR SEVERE WEATHER BEYOND SOME SUB-SEVERE WIND GUSTS WITH THE
STRONGEST STORMS. MODELS ARE IN GENERAL AGREEMENT WITH THE SURFACE
FRONT CROSSING EAST OF THE MS RIVER AROUND NOON FRIDAY AND HAVE
LIMITED AFTERNOON POPS TO SLIGHT OR LOW END CHANCE POPS TO THE
WEST...WITH HIGHER CHANCES TO THE EAST THROUGH THE AFTERNOON.
CLOUDS AND HIGHER DEWPOINTS WILL HOLD TEMPERATURES IN THE 60S FOR
LOWS TONIGHT. WITH GRADUAL CLEARING FROM WEST TO EAST FRIDAY
AFTERNOON AND DEVELOPING POST-FRONTAL COOL ADVECTION W-NW
WINDS...HAVE HIGHS LIMITED TO THE LOWER TO MID 70S...WITH SOME UPPER
70S POSSIBLE IN THE SOUTH AND EAST WHERE THE FROPA WILL BE LATEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
FRIDAY NIGHT... WALKED OUT PCPN CHANCES DURING THE EVENING HOURS...
WITH THE ENTIRE CWFA PCPN-FREE BY 03Z. CANADIAN HIGH PRESSURE THEN
USHERS IN COOL AND DRY CONDITIONS ON A LIGHT NNW BREEZE...WITH 850MB
TEMPS OF 6-8C COMING DOWN ACROSS THE AREA. NEAR RECORD OR RECORD COLD
TEMPERATURES ARE POSSIBLE BOTH EARLY SATURDAY MORNING AND AGAIN
SUNDAY MORNING...WITH SUNDAY HAVING THE BETTER POTENTIAL. LOWS BOTH
MORNINGS WILL BE IN THE UPPER 40S TO MID 50S. DAYTIME HIGHS ON
SATURDAY WILL STRUGGLE TO REACH THE UPPER 60S TO NEAR 70 ALONG
HIGHWAY 20...WHILE TO THE SOUTH THEY WILL INCH UPWARDS INTO THE
LOWER TO MIDDLE 70S. WITH NNW WINDS AT 10-15 MPH SAT PM...IT WILL
FEEL QUITE FALL-LIKE. SUNDAY WILL BE SLIGHTLY WARMER WITH HIGHS IN
THE LOWER 70S NORTH TO UPPER 70S SOUTH ALONG WITH LIGHTER WINDS.
MONDAY THROUGH WEDNESDAY TEMPERATURES WILL MAINLY BE IN THE MID 70S
TO LOW 80S...BUT STILL BELOW NORMAL. MODELS CONTINUE TO INDICATE
THAT THE UPPER LEVEL RIDGE WILL BREAK DOWN/MOVE EAST/ ALLOWING A
SHORT WAVE TO MOVE ACROSS THE CENTRAL PLAINS INTO MO MONDAY INTO
TUESDAY...POSSIBLY BRINGING AN MCS GENERALLY EASTWARD ALONG THE
IA/MO BORDER. THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS STILL
LOOK TO BE DURING THE MONDAY NIGHT AND TUESDAY TIME FRAME. MODEL
CONSENSUS HAS POPS FOR MON NIGHT AT 40-50 WITH 30 POP FOR
TUESDAY...WITH GENERALLY SLIGHT CHANCES BEFORE AND AFTER. AT THIS
TIME...IT APPEARS AREAS SOUTH OF I 80 HAVE THE BEST CHANCE AT SEEING
THIS ACTIVITY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 613 AM CDT THU JUL 25 2013
LIGHT AND VARIABLE WINDS WILL TURN TO THE SOUTH BY AFTERNOON AS
HIGH PRESSURE SHIFTS EAST OF THE REGION. CONDITIONS WILL REMAIN
VFR WITH PERIODS OF MID AND HIGH LEVEL CLOUDS THROUGH THE DAY.
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AND POSSIBLY MOVE
INTO EASTERN IA THIS EVENING...THEN LIKELY BECOME MORE WIDESPREAD
AFTER MIDNIGHT INTO FRIDAY MORNING AS A COLD FRONT MOVES THROUGH
THE REGION. THE LATEST FORECASTS HAVE THIS HANDLED WITH PROB30
GROUPS IN THE EVENING...THEN PREVAILING SHOWER AND THUNDERSTORM
COVERAGE WITH MVFR VISIBILITIES AFTER MIDNIGHT AT CID...DBQ AND
MLI. THE POTENTIAL FOR THUNDERSTORMS REACHING THE BRL SITE IS LESS
CERTAIN THUS ONLY A PROB30 GROUP IS INCLUDED TOWARD SUNRISE.
&&
.CLIMATE...
ISSUED AT 335 AM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...SHEETS
CLIMATE...14
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
619 AM CDT THU JUL 25 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIMEFRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEWPOINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 619 AM CDT THU JUL 25 2013
STILL RATHER LOW CONFIDENCE IN TSRA FORECAST THIS AFTERNOON THANKS
TO COLD FRONT SLIPPING THROUGH BEING RATHER ILL-DEFINED. SEEING
QUITE A BIT OF VARIABILITY FROM HOUR TO HOUR FOR WHERE/WHEN THE
HRRR DEVELOPS STORMS...BUT THERE IS A TREND BETWEEN THE
HRRR...6Z HOPWRF AND 6Z NAM FOR ACTIVITY THIS AFTERNOON TO BE A
BIT FARTHER SOUTH THAN INITIALLY THOUGHT...POSSIBLY REMAINING
SOUTH OF ALL TERMINALS. STILL TO DIFFICULT TO PIN DOWN EVEN A 4
HOUR WINDOW FOR WHEN TSRA MAY OCCUR...SO CONTINUED TO PLAY THINGS
RATHER CONSERVATIVELY IN TAFS WITH VCSH GROUPS. LATE TONIGHT...CAA
WILL START TO INCREASE ACROSS CENTRAL MN...WITH THE NAM/GFS
HINTING AT SOME MVFR STRATOCU COMING DOWN WITH IT. FOR
WINDS...WEAK GRADIENT MEANS WEAK WINDS...WITH DIRECTIONS LIKELY
BOUNCING AROUND A BIT FROM THE NW TO SW. STRONG NW WINDS LOOK TO
HOLD OFF UNTIL FRIDAY MORNING/AFTERNOON.
KMSP...FAIRLY LOW CONFIDENCE IN TAF...WITH CURRENT TRENDS IN SHORT
TERM MODELS AND 6Z NAM GOING SOUTH OF THE FIELD WITH AFTERNOON
CONVECTION. CAN NOT RULE TSRA COMPLETELY...BUT STARTING TO LOOK
LIKE THE REST OF DAY MAY BE DRY. LATE TONIGHT INTO FRIDAY
MORNING...WILL LIKELY HAVE A BANK OF STRATOCU COMING DOWN WITH
SURGE OF COLD AIR WHICH MAY BRING MVFR CIGS IN FRIDAY MORNING.
/OUTLOOK FOR KMSP/
FRI...MVFR CIGS POSSIBLE. WINDS NW 15G25 KTS.
SAT...VFR. WINDS NW 10G20 KTS.
SUN...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
655 AM CDT Thu Jul 25 2013
.SHORT TERM...(Today through Friday night)
Issued at 401 AM CDT THU JUL 25 2013
Dominant northwest flow pattern aloft will continue east of the
Rockies during this period. This pattern will continue to tease us
on rain potential as shortwave troughs and associated convection
roll out of the Northern and Central High Plains. Early this morning
is no different than the past couple of nights, except, dare I say,
this time it looks different. The initial activity fell apart over
southwest NE, however new convection formed over northwest KS and
appears to be holding its own as it tracks eastward. 06Z HRRR
reflectivity output and 06Z NAM/GFS/ECMWF are more supportive of
holding the precipitation together longer than previous features
rolling across KS/NE. However, convection will be heading into a
less favorable airmass which lies over MO so won`t get carried away
and spread PoPs too far into western MO until later tonight.
Models have also been consistent in developing a large MCS over KS
tonight and sliding it southeast, and yes once again bypassing most
of the CWA. However, believe there will be scattered convection
which forms further northeast over the CWA after midnight ahead of a
cold front dropping south across IA. Overall, tonight/Friday morning
will provide at least chance PoPs for everyone, although qpf amounts
will be rather puny except for the southern counties where deeper h8
moisture is expected to advect in from the southwest.
A pronounced upper trough will rotate southeast through the Upper MS
Valley tonight and into the Great Lakes on Friday. Models are all in
agreement that the upper trough will be deeper and track further
south than previous forecasts. This will drive a cold front
southward a bit faster. Any scattered shower activity ahead of the
front will be pushed aside by the passage of the front. High
pressure building in behind the front will draw abnormally cool air
southward Friday/Friday night. Have lowered Saturday morning lows by
3-5F with readings falling into the lower to middle 50s and
approaching the record low of 55 at MCI.
.LONG TERM...(Saturday through Wednesday)
Issued at 401 AM CDT THU JUL 25 2013
Saturday - Sunday:
Tranquil conditions are expected through the weekend as surface high
pressure builds in behind the cold front which passes through the
area on Friday. The area will be under cool northwest flow aloft on
the back side of an slow moving upper level trough moving through
the Great Lakes. This will allow for very pleasant and below average
high temperatures, ranging from the mid 70 to low 80s this weekend.
Sunday night - Tuesday night:
By the end of the weekend, the flow across the CONUS becomes
quasi-zonal as an upper level ridge out west over the weekend begins
to get flattened out by a series of shortwaves. The first of these
shortwaves is progged to reach the area by Sunday night/Monday
morning. Models continue to be consistent in advertising that these
shortwaves may lead to a prolonged period of precipitation chances.
The best chance for precipitation appears to be between Monday and
Tuesday and as such have higher end chance POPs through that period.
Precipitation will diminish Tuesday night as the shortwaves push
east. Temperatures Monday and Tuesday will continue to remain below
average with cloudy skies and precipitation chances. Highs Monday
and Tuesday will be in the upper 70s to mid 80s.
Wednesday:
Towards the end of the extended period the western ridge looks to
reassert itself. This will put the area back under northwest flow
aloft. Still can not rule out another shortwave moving through the
area but no confidence in timing and placement so have slights in
for Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 653 AM CDT THU JUL 25 2013...Corrected
VFR conditions expected through the forecast period, even if/when any
convection moves through the terminals.
Monitoring convective complex over north central KS closely as it
continues tracking east along and north of I-70. A short range
convective allowing model, HRRR, and now the 06Z GFS hold this
activity together through the morning and afternoon hours. They
bring active convection into all 3 terminals after 19Z. All other
models are dry over the 3 terminals until later this evening.
Similar activity over the past several mornings dissipated by the
time it reached far eastern KS. However, the HRRR has been accurate
the last several nights so will need to monitor radar and satellite
trends and amend if necessary.
Should the north central KS convection hold together and affect the
terminals this afternoon it will likely affect timing on any
additional storms which are expected to move into eastern KS and
western MO later tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...73
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
621 AM CDT THU JUL 25 2013
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
CHANCE FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON/EVENING IS THE
MAIN CONCERN. A LITTLE TOO LOW OF CONFIDENCE IN COVERAGE TO
INCLUDE A PREVAILING GROUP OR A THUNDER MENTION JUST YET...BUT DID
TEMPO IN A SHOWER MENTION AT ALL SITES FOR THE MOST LIKELY TIME
WINDOW FOR SHOWERS. THOUGH TEMPO GROUP KEEPS VFR CEILINGS AND
VISIBILITY...HEAVIER SHOWERS COULD LOWER VISIBLITIES BRIEFLY TO
MVFR OR EVEN IFR. SOUTH WINDS SHOULD DOMINATE THIS
AFTERNOON...WITH SPEEDS INCREASING BY MIDDAY. BEHIND THE
FRONT...WINDS SHOULD INCREASE OUT OF THE NORTHWEST. SOME MODELS
HINT AT RESTRICTED VISIBILITY OR CEILINGS...BUT THIS IS LATE IN
THE PERIOD...AND HAVE KEPT MENTIONS ABOVE VFR THRESHOLDS FOR NOW
UNTIL CONFIDENCE INCREASES.
MAYES
&&
.PREV DISCUSSION... /ISSUED 305 AM CDT THU JUL 25 2013/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
..AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
..BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
603 AM MDT THU JUL 25 2013
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
&&
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE FOLLOWING ZONES...
NMZ508-509-520-524>526-539-540.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
743 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH ACROSS THE AREA THIS MORNING. THE
FRONT WILL STALL OFFSHORE THEN RETURN NORTH LATE SATURDAY. ANOTHER
COLD FRONT WILL APPROACH THE AREA EARLY NEXT WEEK. UNSETTLED
WEATHER IS EXPECTED FOR MUCH OF THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
INTERESTING SCENARIO THIS MORNING AND FOR THE NEAR TERM.
APPROACHING COLD FRONT IS HARD TO PICK OUT IN THE VERY BROAD
TROUGH OF LOW PRESSURE THAT NOW ENCOMPASSES MUCH OF THE ATLANTIC
COASTAL STATES AND OFFSHORE. WINDS HAVE TURNED NW MOST LOCATIONS
BUT THIS SEEM TO BE FOLLOWING FROM AN OUTFLOW BOUNDARY THROWN OFF
BY A LARGE AREA OF CONVECTION TO OUR NW. BEST GUESS IS THAT COLD
FRONT IS NOW ENTERING THE COASTAL PLAINS OF THE CAROLINAS FROM THE
NW. RADAR AND SATELLITE LOOPS SHOW A BROAD CIRCULATION DEVELOPING
WITHIN THE TROUGH OFFSHORE OF THE CAROLINAS SE OF CAPE FEAR. THIS
IS FORECAST BY THE MODELS...WHICH PULL IT TO THE NE THROUGH THE
NEAR TERM. NW FLOW WILL STRENGTHEN IN ITS WAKE...ALLOWING AN
ACTUAL SURGE OF SO-CALLED COLD...MORE LIKE COOL.. ADVECTION TO
TAKE PLACE LATE IN THE PERIOD. THIS WILL ALLOW OVERNIGHT
TEMPERATURES TO DROP BELOW NORMAL...UPPER 60S TO AROUND 70 MOST
PLACES FOR MINIMUMS. TODAYS TEMPERATURES LIKEWISE A BIT BELOW
NORMAL...WITH UPPER 80S MOST LOCATIONS.
WATER VAPOR LOOPS SHOW SIGNIFICANT DRYING IN THE WAKE OF THE COLD
FRONT. MODEL SOUNDINGS SHOW PRECIPITABLE WATERS VALUES CRASHING
THROUGH THE PERIOD AS THE MID AND UPPER LEVELS DRY OUT...WITH
CONTENTS DOWN NEAR AN INCH BY DAYBREAK FRIDAY AS COMPARED TO PRESENT
2 IN VALUES. LOWER LEVELS WILL STILL BE MOIST ENOUGH FOR CONVECTION
TODAY AND POSSIBLY THIS EVENING...BUT NO MORE THAN ISOLATED TO
SCATTERED ACTIVITY EXPECTED GIVEN DRY AIR MOVING IN ALOFT. SURFACE
DEWPOINTS WILL HOVER AROUND 70 MOST OF THE DAY BEFORE FINALLY
FALLING OVERNIGHT. THE AFTER MIDNIGHT PERIOD IS EXPECTED TO BE DRY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...COLD FRONT WILL REMAIN STALLED OFF THE
COAST FOR MUCH OF THE PERIOD. DEEP DRY AIR AND COOL LOW LEVEL
NORTHERLY FLOW FRI WILL KEEP TEMPERATURES BELOW CLIMO AND LIMIT
PRECIP CHANCES. LOW LEVEL STABILITY AND SUBSIDENCE/DRY AIR
ALOFT...IN THE WAKE OF EXITING 5H TROUGH...SHOULD PREVENT DEEP
CONVECTION. CANNOT RULE OUT AN ISOLATED WEAK SHOWER ALONG THE SEA
BREEZE BUT DO NOT FEEL MENTIONABLE POP IS WARRANTED. HAVE DECIDED
TO DROP POP TO 10 OR LESS FRI AND FRI NIGHT.
DEEP 5H LOW MOVING OVER THE GREAT LAKES SAT INDUCES 5H TROUGHING
OVER THE SOUTHEAST. TROUGH AXIS WILL REMAIN WEST OF THE AREA
THROUGH THE END OF THE PERIOD WITH SOUTHWEST FLOW STARTING
MOISTURE RETURN AS EARLY AS LATE FRI NIGHT. PRECIPITABLE WATER
VALUES CLIMB FROM 1.2 FRI TO 1.8 SAT EVENING. WEAK SURFACE
GRADIENT RESULTS IN SEA BREEZE DEVELOPMENT SAT AFTERNOON WHICH
HELPS PUSH REMAINS OF STALLED FRONT BACK TO THE COAST. THE SEA
BREEZE AND SURFACE BOUNDARY MAY HELP GENERATE SOME CONVECTION
LATE SAT. HAVE MAINTAIN MENTION OF POP IN FORECAST BUT GIVEN
LIMITING FACTORS HAVE DROPPED THEM DOWN TO SLIGHT CHC.
TEMPERATURES REMAIN BELOW CLIMO FOR THE SECOND HALF OF THE PERIOD
DESPITE DEVELOPMENT OF WEAK LOW LEVEL SOUTHERLY FLOW LATER SAT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...DEEP 5H LOW SLOWLY CROSSING THE GREAT LAKES
EARLY NEXT WEEK WILL LEAD TO UNSETTLED CONDITIONS ACROSS THE
CAROLINAS FOR MUCH OF THE PERIOD. WEAK BUT LARGE SCALE TROUGHING
ALOFT STEEPENS LAPSE RATES WITH WEAK FEATURES ROTATING THROUGH THE
TROUGH ENHANCING LIFT. ENVIRONMENT WILL BE MOIST WITH PRECIPITABLE
WATER VALUES AROUND OR ABOVE 2 INCHES FOR MUCH OF THE PERIOD. IN
ADDITION A COLD FRONT WILL DROP INTO THE AREA AND STALL ACROSS OR
JUST WEST OF THE AREA LATE MON OR TUE. INHERITED HIGH CHC DIURNAL
POP STILL APPEARS VALID. TRYING TO DELINEATE FAVORED POP TIME ANY
FURTHER BASED ON POTENTIAL WAVES OR SURFACE BOUNDARIES SEVERAL DAYS
OUT IS QUITE DIFFICULT AT BEST. GIVEN THE PRESENCE OF A SURFACE
BOUNDARY AND STEEPER MID LEVEL LAPSE RATES CONVECTION MAY LINGER
LONGER INTO THE OVERNIGHT HOURS THAN WOULD NORMALLY BE
EXPECTED...ESPECIALLY IF SHORTWAVES ARRIVE AT THE RIGHT TIME. WILL
CONTINUE TO CARRY LOW CHC POP OVERNIGHT.
TEMPERATURES WILL REMAIN WITHIN A FEW DEGREES OF CLIMO NEXT WEEK.
WEAK 5H TROUGHING AND CLOUD COVER WILL KEEP HIGHS SLIGHTLY BELOW
CLIMO FOR MUCH OF THE PERIOD. LINGERING CLOUDS AND MOISTURE WILL
KEEP LOWS SLIGHTLY ABOVE CLIMO.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS THE FORECAST
AREA THIS MORNING WITH PREVAILING NORTHERLY FLOW AT ALL TERMS. RADAR
INDICATES SOME LIGHT PCPN ACTIVITY IS CURRENTLY NEAR KLBT...AND
TEMPO MVFR/IFR CIGS ARE POSSIBLE HERE IN THE NEAR TERM. WILL INCLUDE
VCSH FOR THE INLAND SITES THROUGH THE MORNING HOURS BASED ON CURRENT
RADAR TRENDS. WATER VAPOR IMAGERY AND FCST SOUNDINGS DEPICT DRIER
AIR MOVING IN THIS AFTN BEHIND THE FRONT...AND THE LATEST HRRR RUNS
SHOW VERY LITTLE IN THE WAY OF PCPN TODAY. ALONG THE COAST...WILL
INTRODUCE VCSH IN THE EARLY AFTN AS ISOLATED SHOWERS CANNOT BE RULED
OUT. BUT OVERALL PCPN COVERAGE SHOULD BE LIMITED BY MID-LEVEL DRYING
THROUGH THE AFTN/EVENING HOURS. THE WINDS WILL REMAIN N/NE AOB 10
KTS TODAY. DO NOT ANTICIPATE ANY FOG/STRATUS IMPACTS FOR THE
OVERNIGHT HOURS ATTM.
EXTENDED OUTLOOK...ISOLATED SHOWERS/T-STORMS SATURDAY...INCREASING
IN COVERAGE SUNDAY AND MONDAY AS ANOTHER FRONT APPROACHES THE CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:30 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LIGHT WINDS WITH SEAS IN THE 2 FT RANGE OVER THE WATERS THROUGH
THE PERIOD AS A COMPLEX SYSTEM WITH A WEAK GRADIENT MOVES ACROSS
THE WATERS. A BROAD AREA OF LOW PRESSURE IS FORMING IVER THE
WATERS THIS MORNING...LEADING TO VARIABLE WINDS. THESE WINDS WILL
TURN MORE NORTHERLY LATER THIS MORNING AS A COLD FRONT MOVES
ACROSS THE WATERS. WINDS WILL REMAIN LIGHT HOWEVER...WITH SEAS
HOVERING IN THE 2 FT RANGE THROUGH THE OVERNIGHT PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...COLD FRONT WILL BE STALLED EAST OF THE
WATERS INTO SAT WITH LIGHT NORTHERLY FLOW OVER THE WATERS. WEAK
GRADIENT WILL ALLOW DEVELOPMENT OF SEA BREEZE...WHICH WILL END UP
PUSHING THE REMAINS OF THE FRONT INLAND SAT EVENING. LIGHT
SOUTHERLY FLOW DEVELOPS LATE SAT AND SAT NIGHT. GRADIENT REMAINS
WEAK THROUGH THE PERIOD AND SPEEDS ARE EXPECTED TO REMAIN 10 KT OR
LESS. SEAS AROUND 2 FT INTO SAT WILL BUILD TO 2 TO 3 FT SAT NIGHT
AS ONSHORE FLOW DEVELOPS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...LIGHT SOUTH TO SOUTHWEST FLOW WILL PERSIST
THROUGH THE PERIOD. BERMUDA HIGH REMAINS ANCHORED OFF THE COAST
WHILE INLAND DISSIPATING BOUNDARY SUN WILL BE SUPERSEDED BY SLOW
MOVING COLD FRONT MON. THIS WILL INCREASE THE GRADIENT DURING THE
SECOND HALF OF THE PERIOD...RESULTING IN A SLIGHT INCREASE IN WIND
SPEEDS. ON SUN SPEEDS WILL BE 10 KT OR LESS THEN INCREASE TO 10 TO
15 KT FOR MON. SEAS WILL RUN 2 TO 3 FT...MOSTLY AS WIND WAVE.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 AM THURSDAY...HAVE ISSUED ANOTHER COASTAL FLOOD ADVISORY
FOR THE CAPE FEAR RIVER IN THE VICINITY OF WILMINGTON FOR TONIGHT.
HIGH TIDE IS PREDICTED FOR 12:58 AM FRIDAY AND EXPECT THE RIVER
LEVEL AT THE TIDE GAUGE IN DOWNTOWN WILMINGTON TO TOP OUT JUST
BELOW 6 FT. THIS IS ABOUT A HALF FOOT ABOVE MINOR FLOOD STAGE
CRITERIA.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 2 AM EDT
FRIDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR
MARINE...REK/III
TIDES/COASTAL FLOODING...REK
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1044 AM CDT THU JUL 25 2013
.UPDATE...
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AFTERNOON TAKING THE
SCATTERED SHOWERS/STORMS ALONG WITH MOST OF THE CLOUD COVER WITH
IT. VISIBLE SATELLITE AND RADAR SHOW THIS EASTWARD MOVEMENT/CLEARING
LATE THIS MORNING. WILL ADJUST GRIDS TO REFLECT THIS TREND.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA
DURING THE DAY. NO SEVERE WEATHER IS EXPECTED...BUT VSBYS MAY
BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE THUNDERSTORMS.
OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
623 AM CDT THU JUL 25 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE AREA
DURING THE DAY. NO SEVERE WEATHER IS EXPECTED...BUT VSBYS MAY
BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE THUNDERSTORMS.
OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
954 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
709 AM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
647 AM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 647 AM CDT THU JUL 25 2013
SHOWERS AND A FEW THUNDERSTORMS HAVE DROPPED INTO PORTIONS OF
SOUTHEAST MINNESOTA AND WEST CENTRAL WISCONSIN EARLY THIS
MORNING...AHEAD OF A SHORTWAVE THAT AS OF 11Z WAS LOCATED NEAR
MINNEAPOLIS. THESE SHOWERS AND STORMS SHOULD CONTINUE MARCHING
SOUTHEAST THROUGH MUCH OF THE FORECAST AREA...AIDED BY A ZONE OF
850MB MOISTURE TRANSPORT AHEAD OF THE SHORTWAVE.
DURING THE AFTERNOON AND EVENING...MESOSCALE MODEL GUIDANCE FROM
THE LAST FEW HRRR RUNS...THE 25.00Z HIRES-ARW/HIRES-NMM/NSSL WRF-
ARW ARE ALL IN PRETTY GOOD AGREEMENT IGNITING CONVECTION AS EARLY
AS 19-20Z ACROSS SOUTHERN MN AND NORTHERN IOWA. APPEARS TWO
FORCING MECHANISM COME INTO PLAY:
1. 850MB MOISTURE TRANSPORT AHEAD OF A CONVECTIVE SHORTWAVE
EMANATING OUT OF THE STORMS CURRENTLY IN WESTERN SOUTH DAKOTA.
2. THE COLD FRONT CURRENTLY ALONG THE DAKOTAS/MN BORDER.
THE QUESTION BECOMES DO THE STORMS GET OUT OF HERE QUICKER THAN
FORECAST WHICH THE AFOREMENTIONED MESOSCALE MODELS SUGGEST. GOING
FOR THE QUICKER EXIT OF STORMS WOULD BE THE COOLING OUTFLOWS FROM
THE STORMS STABILIZING THE ATMOSPHERE...AND POSSIBLY PUSHING THE
COLD FRONT THROUGH FASTER. HOWEVER...THEN THERE IS THE 25.00Z
ECMWF/REGIONAL CANADIAN MODELS WHICH SEEM TO PUT MORE FOCUS ON
CONVECTIVE ACTIVITY IN THE EVENING. THESE MODELS RELY ON A
STRONGER INCREASE OF 850MB MOISTURE TRANSPORT AHEAD OF THE
SHORTWAVE TROUGH DROPPING OUT OF SOUTHERN MANITOBA INTO NORTHERN
MN. FOR NOW HAVE TRENDED THE TONIGHT FORECAST TO BE A COMPROMISE
APPROACH BETWEEN THE ECMWF AND HI RESOLUTION MODEL
GUIDANCE...LOWERING CHANCES A LITTLE BIT OVER NORTHWESTERN
PORTIONS OF THE FORECAST AREA FOR THE EVENING. THE SPEED THAT
CONVECTION GETS OUT OF HERE WILL HAVE TO BE LOOKED AT MORE THROUGH
THE DAY.
SEVERE POTENTIAL REMAINS...WITH 25.09Z HRRR SUGGESTING AN ISOLATED
SEVERE STORM OR TWO POSSIBLE. TIME PERIOD OF SEVERE POTENTIAL ON
TRACK...BETWEEN 3 AND 8 PM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
TODAY WITH THE POTENTIAL FOR STRONG TO SEVERE STORMS. FOCUS THEN
TURNS TO SHOWER AND STORM CHANCES FRIDAY...THEN ONTO TEMPERATURES
FOR THE WEEKEND.
LATEST WATER VAPOR IMAGERY AND 500 MB RAP ANALYSIS SHOWED NORTHWEST
FLOW ALOFT ACROSS THE UPPER MIDWEST. SEVERAL EMBEDDED SHORTWAVES
NOTED IN THE THE FLOW WITH A LEADING WEAK WAVE OVER SOUTH CENTRAL
MINNESOTA AND ANOTHER WAVE MOVING INTO NORTHWEST SOUTH DAKOTA. A
POTENT TROUGH WAS DIGGING INTO SOUTHERN SASKATCHEWAN/MANITOBA. THIS
TROUGH WILL BRING FALL-LIKE TEMPERATURES TO THE REGION FOR THE
WEEKEND. SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM
NORTH CENTRAL MINNESOTA SOUTHWEST ACROSS SOUTHERN NORTH DAKOTA AND
WAS PUSHING SOUTHEAST. A PREFRONTAL TROUGH WAS NOTED AS WELL
STRETCHING FROM NORTHEAST MINNESOTA SOUTH THROUGH CENTRAL MINNESOTA
INTO EASTERN SOUTH DAKOTA.THE TROUGH AND COLD FRONT WILL BE THE
FOCUS FOR SHOWER AND STORM DEVELOPMENT LATE THIS MORNING THROUGH THE
AFTERNOON HOURS AND INTO THIS EVENING.
ISOLATED SHOWERS AND STORMS WILL JUST EDGE INTO SOUTHEAST MINNESOTA
AND WEST CENTRAL WISCONSIN THIS MORNING AS WEAK 850 MB MOISTURE
TRANSPORT MOVES INTO THE AREA. THIS ACTIVITY SHOULD WEAKEN AS IT
SLIDES SOUTHEAST THIS MORNING. ADDITIONAL DEVELOPMENT IS EXPECTED BY
LATE MORNING ALONG THE PREFRONTAL TROUGH LATE THIS MORNING INTO THE
EARLY AFTERNOON HOURS. MID AND HIGH LEVEL CLOUDS WORKING INTO THE
AREA FROM THE WEST WILL HAVE AN IMPACT ON HOW MUCH SURFACE
TEMPERATURES WARM TODAY. DEPENDING ON HOW MUCH WARMING
OCCURS...SEVERE THUNDERSTORMS ARE POSSIBLE MAINLY IN THE 3 TO 8 PM
TIMEFRAME. 0-6 KM BULK SHEAR VALUES INCREASE FROM AROUND 25 KTS
LATE THIS MORNING TO 35 TO 40 KTS LATE AFTERNOON INTO THE EVENING
HOURS. THE NAM CONTINUES TO BUILD STRONG INSTABILITY THIS
AFTERNOON WITH 0-3 KM MUCAPE VALUES CLIMBING TO AROUND 3000 J/KG.
THIS WOULD BE IF DEWPOINTS WOULD CLIMB INTO THE UPPER 60S TO LOWER
70S AND SURFACE TEMPERATURES WARM INTO THE LOWER 80S. SURFACE
TEMPERATURES ARE FORECAST TO CLIMB INTO THE UPPER 70S TO THE LOWER
80S BUT DEWPOINTS WILL BE MUCH LESS...IN THE 62 TO 65 DEGREE
RANGE. THINKING 0-3KM MUCAPE VALUES IN THE 1200 TO 1700 J/KG RANGE
SEEM MORE REALISTIC. THE POTENTIAL EXIST FOR A FEW ROUNDS OF
SHOWERS AND STORMS ALONG THE PREFRONTAL TROUGH AND ANOTHER TONIGHT
AS THE UPPER TROUGH DIVES SOUTHEAST INTO THE REGION AND THE COLD
FRONT EDGES CLOSER TO THE FORECAST AREA. IF STORMS HOLD OFF UNTIL
MID TO LATE AFTERNOON...LARGE HAIL AND DAMAGING WINDS MAY OCCUR
WITH THE STRONGER STORMS. THE FRONT IS EXPECTED TO PUSH THROUGH
THE FORECAST AREA LATE TONIGHT INTO EARLY FRIDAY MORNING TAKING
THE BULK OF THE INSTABILITY SOUTH OF THE AREA. HOWEVER...THE
TROUGH WILL MOVE IN ITS WAKE WITH SHOWER AND ISOLATED STORM
CHANCES PERSISTING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 357 AM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS WILL BE ONGOING FRIDAY MORNING...ESPECIALLY
ACROSS CENTRAL AND FAR SOUTHWEST WISCONSIN. THE UPPER LEVEL TROUGH
THEN DIVES INTO THE AREA LATE FRIDAY MORNING INTO FRIDAY AFTERNOON.
SCATTERED TO NUMEROUS SHOWERS WILL DEVELOP AS COLDER AIR ALOFT MOVES
INTO THE AREA. THE TROUGH WILL REMAIN OVER THE REGION FRIDAY NIGHT
INTO SATURDAY AS AN UNSEASONABLY COLD AIRMASS MOVES IN. 850 MB
TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE -2.0 TO -2.5
RANGE...SUGGESTING NEAR RECORD COOL TEMPERATURES FOR THIS TIME OF
YEAR. HIGH TEMPERATURES ON SATURDAY WILL STRUGGLE TO GET OUT OF THE
60S. IN FACT...IT APPEARS LA CROSSE MAY SEE A RECORD LOWEST HIGH
TEMPERATURE FOR THE DATE. LATEST FORECAST IS 68 DEGREES AT LA
CROSSE. THIS WOULD BREAK THE OLD RECORD OF 69 SET BACK IN 1981.
FORECAST MODELS SUGGEST THERE WILL BE ENOUGH INSTABILITY ON SATURDAY
AFTERNOON TO GENERATE SOME SHOWERS...MAINLY ALONG AND NORTH OF
INTERSTATE 94. THIS MAKES SENSE LOOKING AT FORECAST SOUNDINGS
SHOWING SOME WEAK CAPE DURING THE AFTERNOON HOURS. HAVE ADDED A
SLIGHT CHANCE OF SHOWERS OVER CENTRAL WISCONSIN TO ACCOUNT FOR THIS.
ANOTHER SHORTWAVE ROTATES INTO NORTHERN WISCONSIN SATURDAY
NIGHT...BRINGING ADDITIONAL CHANCES FOR SHOWERS OVER NORTH CENTRAL
WISCONSIN. FLOW ALOFT THEN FINALLY STARTS TO TRANSITION TO ZONAL
EARLY NEXT WEEK AS THE TROUGH PUSHES EAST OF THE REGION INTO THE
EASTERN GREAT LAKES. TEMPERATURES WILL RETURN TO MORE SEASONABLE
VALUES FOR NEXT WEEK WITH HIGH CLIMBING BACK INTO THE UPPER 70S TO
AROUND 80. SEVERAL EMBEDDED WAVES IN THE ZONAL FLOW WILL BRINGING
PERIODIC CHANCES FOR SHOWERS AND STORMS MAINLY MONDAY NIGHT
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 647 AM CDT THU JUL 25 2013
A BAND OF SHOWERS AND EVEN A COUPLE THUNDERSTORMS WERE APPROACHING
BOTH TAF SITES AS OF 11Z. THESE SHOULD MOVE THROUGH THE TAF SITES
RELATIVELY QUICKLY...BY 14Z. NO VISIBILITY RESTRICTION IS
ANTICIPATED WITH CEILINGS STAYING VFR. THE VFR CONDITIONS LOOK TO
PERSIST THROUGH EARLY AFTERNOON. A COLD FRONT THEN LOOKS TO
APPROACH THE TAF SITES OUT OF WESTERN MINNESOTA. NUMEROUS SHOWERS
AND THUNDERSTORMS WILL FORM AHEAD OF THIS FRONT...BEING IN THE
VICINITY OF THE TAF SITES PERHAPS AS EARLY AS 17-18Z. CONFIDENCE
HAS INCREASED ENOUGH TO INCLUDE A TIME PERIOD WHERE THUNDERSTORMS
COULD DIRECTLY IMPACT THE TAF SITES...WHICH IS 19-22Z AT RST AND
20-23Z AT LSE. RESTRICTION TO MVFR VISIBILITIES AND CEILINGS IS
LIKELY...AND VISIBILITY COULD EVEN GO LOWER BRIEFLY. ADDITIONALLY
THERE COULD BE GUSTY WINDS AND HAIL...BUT CONFIDENCE IS TOO LOW TO
INCLUDE RIGHT NOW. SHOWERS AND THUNDERSTORMS MAY BE DONE WITH AT
BOTH TAF SITES BY 00Z...BUT NOT ALL MODEL GUIDANCE SUGGESTS SO.
THEREFORE...HAVE HELD ONTO VCTS MENTION TIL 03-04Z. VFR CONDITIONS
ARE EXPECTED TO PERSIST THROUGH THE NIGHTTIME HOURS IN THE WAKE OF
THE COLD FRONTAL PASSAGE. IF THE TAF SITES DO SEE RAIN...THERE
SHOULD BE ENOUGH ALTOSTRATUS AROUND DURING THE NIGHT TO PREVENT
FOG FORMATION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
AREA FORECAST DISCUSSION...UPDATE
NWS TUCSON AZ
955 AM MST THU JUL 25 2013
.SYNOPSIS...A DISTURBANCE ALOFT ACROSS THE AREA WILL ENHANCE
THUNDERSTORM COVERAGE AND INTENSITY ACROSS MOST OF THE AREA TODAY.
SOME STORMS WILL GENERATE HEAVY RAINFALL. OTHERWISE...PLENTY OF
MOISTURE ACROSS THE REGION TO PROVIDE A CHANCE OF MAINLY AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS INTO THE WEEKEND. A DECREASE
IN MOISTURE MAY LEAD TO LESS THUNDERSTORM ACTIVITY EARLY NEXT WEEK.
&&
.UPDATE...HAVE GONE AHEAD AND ISSUED A FLASH FLOOD WATCH FOR ALL OF
SOUTHEAST ARIZONA EXCEPT WESTERN PIMA COUNTY. LATEST VIS SATELLITE
SHOWING A GOOD AMOUNT OF CLEARING WITH THE EXCEPTION OF SOUTHERN
GRAHAM AND NORTHERN COCHISE COUNTY. ALREADY SEEING GOOD CU BUILDUPS
ON AREA MOUNTAINS AS WELL. CONFIDENCE IS HIGH THAT THERE WILL BE
SHOWERS AND THUNDERSTORMS WITH HEAVY RAINFALL AND THINK THE CENTRAL
CWA FROM SANTA CRUZ COUNTY NORTHWARD INTO EASTERN PINAL COUNTY HAS
THE HIGHEST THREAT INITIALLY BUT CONFIDENCE IN EXACT LOCATIONS IS A
BIT LOWER.
.DISCUSSION...THE 12Z KTWC SOUNDING IS DEPICTING A VERY MOIST AND
UNSTABLE ATMOSPHERE. PWAT OF 1.96" IS IN THE 99TH PERCENTILE AND
ABOUT 160 PERCENT OF NORMAL FOR THIS TIME OF YEAR. MEANWHILE...THERE
IS CONSIDERABLY MORE MID LEVEL COOLING COMPARED TO 24 HOURS AGO WITH
THE STUBBORN INVERSION AT ABOUT 500 MB GONE. MODIFIED SOUNDING WITH
T=95 AND TD=61 YIELDS ABOUT 1800 J/KG OF CAPE. THE STEERING FLOW IS
GENERALLY FROM THE EAST AT ABOUT 10 MPH. CURRENT SATELLITE AND RADAR
IMAGERY DEPICT CONVECTIVE SHOWERS MAINLY OVER THE CENTRAL AND
WESTERN DESERTS PUSHING WEST WITH PARTLY TO MOSTLY CLOUDY SKIES
MAINLY FROM DEBRIS CLOUDINESS FROM TUCSON EASTWARD. THERE IS A WELL
DEFINED SHEAR AXIS/DEFORMATION ZONE IN THE MID TO UPPER LEVELS LYING
RIGHT ACROSS THE CENTER OF THE FORECAST AREA TODAY WITH THE REMNANTS
OF AN INVERTED TROUGH. THE BIG QUESTION FOR TODAY IS HOW MUCH
CLEARING WILL WE SEE TO GENERATE SUSTAINED CONVECTION.
AFTER REVIEWING LATEST GUIDANCE...TEND TO FAVOR THE HRRR WHICH IS
HANDLING THE CURRENT CLOUD COVERAGE REALLY WELL ALONG WITH THE LIGHT
SHOWERS WEST OF TUCSON. THE HRRR IS MOST ORGANIZED WITH CONVECTION
THIS AFTERNOON AND EVENING ALONG WITH THE 12Z NAM FROM CENTRAL PIMA
COUNTY EASTWARD. MEANWHILE...THE EARLY 06Z UOFA WRF-GFS AND 12Z
WRF-NAM HAVE CLEARED THINGS OUT TOO QUICKLY. WITH THAT SAID...HAVE
GONE AHEAD AND RAISED POPS AREAWIDE FOR THIS AFTERNOON AND THIS
EVENING. WE THINK THE BEST CHANCE FOR HEAVIEST RAINFALL WILL BE FROM
THE TUCSON AREA EASTWARD. AS THE MORNING PROGRESSES AND SHOULD SKIES
CLEAR AND CONFIDENCE INCREASE...WILL CONSIDER A SHORTER FUSE FLASH
FLOOD WATCH.
&&
.AVIATION...SCT SHRA / ISOLD TSRA THRU FRIDAY MORNING OR 26/17Z.
MVFR CIGS/VSBYS WITH WIND GUSTS APPROACHING 45 KTS WITH THE
STRONGEST TSRA. TSRA COVERAGE INCREASING AFTER 26/17Z.
OTHERWISE...CLOUD DECKS MAINLY 6-10K FT AGL AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU THURSDAY EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ENHANCED MOISTURE WILL PROVIDE A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. OTHERWISE... THERE
WILL BE ENOUGH MOISTURE FOR SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS TO PREVAIL INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
GL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
245 PM EDT THU JUL 25 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH OVER THE EASTERN US WILL REMAIN ACROSS THE
REGION THROUGH THE WEEKEND. THIS WILL INTERACT WITH A WEAK FRONTAL
BOUNDARY TO CONTINUE THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER TROUGH REMAINS OVER THE E CONUS. VORT MAX PUSHING TO OUR
EAST WITH NVA OVER THE FA CURRENTLY. QUITE DRY AIR ALOFT OVER THE
REGION AS WELL. COMBINATION OF DRY AIR ALOFT AND NVA MAY LIMIT
AREAL COVERAGE OF CONVECTION TODAY. FORECAST SOUNDINGS ALSO
INDICATE SOME LOW LEVEL CAPPING EARLY THIS AFTERNOON...BUT
INDICATE THIS COULD BE OVERCOME WITH ENOUGH HEATING AND
CONVERGENCE ALONG ANY BOUNDARIES...SUCH AS SURFACE TROUGH/SEA
BREEZE/OUTFLOWS ETC. NVA IS EXPECTED TO DIMINISH LATE TODAY. ARRAY
OF HIGH RESOLUTION MODEL OUTPUT INCONSISTENT. LATEST HRRR AND RAP
SUGGESTING MINIMAL CONVECTIVE ACTIVITY...WHILE LOCAL WRF AND 12Z
SPC WRF MORE BULLISH ON CONVECTIVE PROSPECTS. NOTHING ON RADAR AT
1730Z...BUT STILL THINK THERE IS THE PREMISE FOR AT LEAST SLIGHT
CHANCE POPS LATE TODAY AND THIS EVENING. ANY THUNDERSTORMS THAT DO
FORM WILL HAVE A HAIL OR WIND GUST THREAT DUE TO DRY AIR ALOFT AND
MODERATE INSTABILITIES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS WILL BE OFF THE COAST TONIGHT WITH A GRADUAL
DRYING TREND AS PRECIPITABLE WATER VALUES FALL DOWN TO BETWEEN
1.25 AND 1.50 INCHES. SUBSIDENCE IN THE WAKE OF THE DEPARTING
UPPER TROUGH ALONG WITH LESS MOISTURE SHOULD PREVENT MUCH IN THE
WAY OF NOCTURNAL CONVECTION. ONLY ISOLATED TO SCATTERED STORMS ON
FRIDAY WITH THE FORECAST AREA FALLING BETWEEN SYSTEMS.
SHORTWAVE ENERGY DIVING SOUTHWARD THROUGH THE GREAT LAKES INTO THE
WESTERN OHIO VALLEY ON SATURDAY WILL CAUSE THE 500MB FLOW TO BACK
MORE SOUTHWESTERLY ACROSS THE SOUTHEAST AND TENNESSEE VALLEY...
RESULTING IN MOISTURE INCREASING AGAIN ACROSS THE REGION.
CONVECTIVE COVERAGE WILL SHOULD BE A BIT BETTER SATURDAY AS WEAK
DISTURBANCES IN THE UPPER FLOW COULD TRIGGER CONVECTION ALTHOUGH
THE MAIN ENERGY WILL REMAIN TO THE NORTHWEST. THE INCREASED
ATMOSPHERIC MOISTURE WILL LEAD TO A BIT MORE DIURNALLY UNSTABLE
AIRMASS AND WILL CARRY HIGHER CHANCE POPS ON SATURDAY AFTERNOON
THAN FRIDAY...WITH A HIGHER POPS ACROSS THE WESTERN COUNTIES.
TEMPERATURES DURING THIS PERIOD WILL BE NEAR NORMAL WITH HIGHS IN
THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE APPEARS TO BE IN REASONABLE AGREEMENT WITH
THE OVERALL PATTERN SHOWING A GENERAL UPPER TROUGH AXIS REMAINING
JUST WEST OF THE FORECAST AREA SUN/MON WITH A SURFACE FRONTAL
BOUNDARY PUSHING INTO OR CLOSE TO THE FORECAST AREA. PRECIPITABLE
WATER VALUES RISE BACK UP TO NEAR 2 INCHES IN VICINITY OF THE
FRONTAL BOUNDARY WHICH WILL STALL OUT OVER THE AREA. THE ECMWF
BACKS THE MID LEVEL FLOW MORE ZONAL THROUGH MIDWEEK WHILE THE GFS
KEEPS A BIT OF A RESIDUAL UPPER TROUGH OVER THE FORECAST AREA.
WILL GO CLOSER TO THE ECMWF FORECAST WITH HIGH CHANCE TO LIKELY
POPS SUN/MON. ALTHOUGH UPPER FLOW BACKS MORE WESTERLY BY MID
WEEK...SHORTWAVE ENERGY MOVING THROUGH THE UPPER FLOW IS EXPECTED
TO MOVE OVER THE AREA AND SPARK DIURNAL CONVECTION WHICH MAY
LINGER INTO THE OVERNIGHT HOURS TUE THROUGH THU. TEMPERATURES
THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR DAYTIME
HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THIS AFTERNOON...WITH SCT TO BKN CU WITH
VFR BASES. SLIGHT CHANCE OF LATE DAY/EVENING CONVECTION...BUT
CHANCES TOO LOW TO INCLUDE TS MENTION IN THE TAFS AT THIS TIME.
SOME RESTRICTIONS POSSIBLE LATE TON/EARLY MON...BUT CONFIDENCE
LOW.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
139 PM EDT THU JUL 25 2013
.SYNOPSIS...
AN UPPER LEVEL TROUGH OVER THE EASTERN US WILL REMAIN ACROSS THE
REGION THROUGH THE WEEKEND. THIS WILL INTERACT WITH A WEAK FRONTAL
BOUNDARY TO CONTINUE THE CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE AREA INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
UPPER TROUGH REMAINS OVER THE E CONUS. VORT MAX PUSHING TO OUR
EAST WITH NVA OVER THE FA CURRENTLY. QUITE DRY AIR ALOFT OVER THE
REGION AS WELL. COMBINATION OF DRY AIR ALOFT AND NVA MAY LIMIT
AREAL COVERAGE OF CONVECTION TODAY. FORECAST SOUNDINGS ALSO
INDICATE SOME LOW LEVEL CAPPING EARLY THIS AFTERNOON...BUT
INDICATE THIS COULD BE OVERCOME WITH ENOUGH HEATING AND
CONVERGENCE ALONG ANY BOUNDARIES...SUCH AS SURFACE TROUGH/SEA
BREEZE/OUTFLOWS ETC. NVA IS EXPECTED TO DIMINISH LATE TODAY. ARRAY
OF HIGH RESOLUTION MODEL OUTPUT INCONSISTENT. LATEST HRRR AND RAP
SUGGESTING MINIMAL CONVECTIVE ACTIVITY...WHILE LOCAL WRF AND 12Z
SPC WRF MORE BULLISH ON CONVECTIVE PROSPECTS. NOTHING ON RADAR AT
1730Z...BUT STILL THINK THERE IS THE PREMISE FOR AT LEAST SLIGHT
CHANCE POPS LATE TODAY AND THIS EVENING. ANY THUNDERSTORMS THAT DO
FORM WILL HAVE A HAIL OR WIND GUST THREAT DUE TO DRY AIR ALOFT AND
MODERATE INSTABILITIES.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS EXPECTED TO BE EAST OF THE FORECAST AREA BY
TONIGHT WITH A GRADUAL DRYING TREND AS PRECIPITABLE WATER VALUES
FALL DOWN TO BETWEEN 1.25 AND 1.50 INCHES. SUBSIDENCE IN THE WAKE
OF THE DEPARTING UPPER TROUGH ALONG WITH LESS MOISTURE SHOULD
PREVENT MUCH NOCTURNAL CONVECTION AND ONLY ISOLATED TO SCATTERED
STORMS ON FRIDAY WITH THE FORECAST AREA FALLING BETWEEN SYSTEMS.
SHORTWAVE ENERGY DIVING SOUTHWARD THROUGH THE GREAT LAKES INTO THE
WESTERN OHIO VALLEY ON SATURDAY WILL CAUSE THE 500MB FLOW TO BACK
MORE SOUTHWESTERLY ACROSS THE SOUTHEAST AND TENNESSEE
VALLEY...RESULTING IN MOISTURE INCREASING AGAIN ACROSS THE REGION.
CONVECTIVE COVERAGE WILL SHOULD BE A BIT BETTER SATURDAY AS WEAK
DISTURBANCES IN THE UPPER FLOW COULD TRIGGER CONVECTION ALTHOUGH
THE MAIN ENERGY WILL REMAIN TO THE NORTHWEST. THE INCREASED
ATMOSPHERIC MOISTURE WILL LEAD TO A BIT MORE DIURNALLY UNSTABLE
AIRMASS AND WILL CARRY HIGHER CHANCE POPS ON SATURDAY AFTERNOON
THAN FRIDAY...ALSO HAVING A GRADIENT FROM WEST TO EAST.
TEMPERATURES DURING THIS PERIOD WILL BE NEAR NORMAL WITH HIGHS IN
THE UPPER 80S TO LOWER 90S AND LOWS IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LITTLE CHANGE MADE DURING THIS PERIOD.
MEDIUM RANGE GUIDANCE APPEARS TO BE IN REASONABLE AGREEMENT WITH
THE OVERALL PATTERN SHOWING A GENERAL UPPER TROUGH AXIS REMAINING
JUST WEST OF THE FORECAST AREA SUN/MON WITH A SURFACE FRONTAL
BOUNDARY PUSHING INTO OR CLOSE TO THE FORECAST AREA. PRECIPITABLE
WATER VALUES RISE BACK UP TO NEAR 2 INCHES IN VICINITY OF THE
FRONTAL BOUNDARY WHICH WILL STALL OUT OVER THE AREA. THE ECMWF
BACKS THE MID LEVEL FLOW MORE ZONAL THROUGH MIDWEEK WHILE THE GFS
KEEPS A BIT OF A RESIDUAL UPPER TROUGH OVER THE FORECAST AREA.
WILL CONTINUE WITH PREVIOUS FORECAST OF HIGH CHANCE TO LIKELY POPS
SUN/MON. ALTHOUGH UPPER FLOW BACKS MORE WESTERLY BY MID
WEEK...SHORTWAVE ENERGY MOVING THROUGH THE UPPER FLOW IS EXPECTED
TO MOVE OVER THE AREA AND SPARK DIURNAL CONVECTION WHICH MAY
LINGER INTO THE OVERNIGHT HOURS TUE/WED. TEMPERATURES THROUGH THE
LONG TERM WILL BE SLIGHTLY BELOW NORMAL FOR DAYTIME HIGHS WITH
OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED THIS AFTERNOON...WITH SCT TO BKN CU WITH
VFR BASES. SLIGHT CHANCE OF LATE DAY/EVENING CONVECTION...BUT
CHANCES TOO LOW TO INCLUDE TS MENTION IN THE TAFS AT THIS TIME.
SOME RESTRICTIONS POSSIBLE LATE TON/EARLY MON...BUT CONFIDENCE
LOW.
EXTENDED AVIATION OUTLOOK...CHANCE OF MAINLY AFTERNOON/EVENING
THUNDERSTORMS. LATE NIGHT/EARLY MORNING FOG/STRATUS POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
212 PM MDT THU JUL 25 2013
.DISCUSSION...EASTERN IDAHO REMAINS IN NOSE OF UPPER RIDGE OVER
GREAT BASIN TODAY. RADAR/SAT SHOW CONVECTION BUBBLING OVER HIGHER
ELEVATION AREAS PARTICULARLY CENTRAL MOUNTAINS AND SOUTHERN
HIGHLANDS IN WEAKLY UNSTABLE AREAS. HRRR PLACES BEST THREAT OF
CONVECTION OVER CENTRAL MOUNTAINS AND ALONG DIVIDE 21-03Z THOUGH
RADAR SHOWS CURRENT RETURNS OVER SOUTHERN HIGHLANDS. AIRMASS
AGAIN DESTABILIZES AGAIN ON FRIDAY WHILE UPPER LOW OVER BC CANADA
CONTINUES TO DROP TOWARD THE PACNW STATES. MOISTURE PULLED NORTH
FROM NEVADA FRIDAY INTO SATURDAY AHEAD OF FRONTAL BOUNDARY
DEVELOPING ACROSS THE REGION. BOTH GFS AND NAM HINTING AT
CONVECTION CONTINUING OVERNIGHT FRIDAY NIGHT SO MAINTAINED POPS
HIGH ENOUGH TO GET ISOLATED MENTION. UNSTABLE AIRMASS AHEAD OF
FRONTAL BOUNDARY IN PLACE SATURDAY WITH NAM SHOWING LIFTEDS OF -2
TO -4 AND MUCAPE CLOSE TO 1000 J/KG. FRONTAL BOUNDARY SHIFTS
SLIGHTLY EAST FOR SUNDAY WITH DRIER AIR PUSHING BACK INTO THE
CENTRAL MOUNTAINS. THUS EASTERN/SOUTHERN HIGHLANDS WOULD BE BEST
THREAT LOCATION FOR CONTINUED CONVECTION INTO SUNDAY. UPPER RIDGE
TRIES TO NOSE BACK INTO THE REGION MONDAY THRUOGH REMAINDER OF
FCST PERIOD. CANT COMPLETELY RULE OUT CONVECTION DAY TO DAY UNDER
INFLUENCE OF SOUTHWEST FLOW WITH RIDGE AXIS TO THE EAST AND TROUGH
TO THE WEST. THUS MAINTAINED WEAK POPS MAINLY HIGHER ELEVATIONS
FOR EACH DAY. DMH
&&
.AVIATION...VFR CONDITIONS LIKELY TO CONTINUE TODAY/FRIDAY. AREA OF
CONVECTION CURRENTLY DEVELOPING NORTH OF KSUN AND ALSO ACROSS THE
SRN HIGHLANDS. CLOUD DRIFT INDICATES THAT KSUN MY SEE A TSTM IMPACT
LATER THIS EVE SO HAVE CONTINUED MENTION OF VCTS THIS EVENING. WILL
LIKELY SEE SIMILAR ACTIVITY FRIDAY AFTERNOON. HUSTON
&&
.FIRE WEATHER...UPPER RIDGE REMAINS POSITIONED OVER THE GREAT BASIN
WITH LIMITED UPPER MOISTURE STREAMING THROUGH IDAHO. VISIBLE
SATELLITE IMAGERY WAS SHOWING THINGS DESTABILIZING MODESTLY THIS
AFTERNOON WITH EXPECTATION THAT ISOLATED CONVECTION WILL DEVELOP
OVER THE CNTRL AND SRN MOUNTAINS LATE THIS AFTN/EVE THEN DISSIPATE
OVERNIGHT. UPPER TROUGH OFF THE NW BRITISH COLUMBIA COAST WILL
MIGRATE EAST FRIDAY THROUGH SUNDAY. EXPECT ENOUGH MOISTURE AND
INSTABILITY ACROSS THE CNTRL MOUNTAINS TO SUPPORT THUNDERSTORM
ACTIVITY ONCE AGAIN FRIDAY ALTHOUGH GFS/NAM AT ODDS IN THIS REGARD.
SURFACE FRONT ASSOCIATED WITH ADVANCING TROUGH WILL BLEED INTO THE
CNTRL MOUNTAINS SATURDAY AFTERNOON PRODUCING GUSTY WINDS. AFTER
COORD WITH LOCAL DISPATCH AGENCIES...WILL HOIST A FIRE WEATHER WATCH
FOR THE CNTRL IDAHO MOUNTAIN ZONES 422/475/476 FOR GUSTY WINDS AND
LOW RH SATURDAY AFTERNOON/EVE. FRONT GATHERS ITSELF SATURDAY NIGHT
ALONG A LINE FROM DUBOIS-ARCO-JEROME AND THEN MAKES A FINAL PUSH
THROUGH THE SNAKE PLAIN/SE HIGHLANDS SOMETIME SUNDAY. MAY NEED TO
ISSUE HEADLINES FOR EASTERN MAGIC VALLEY/SNAKE PLAIN WITH INITIAL
PUSH SATURDAY AFTERNOON CONTINUING INTO SUNDAY...BUT CONFIDENCE
AT THIS TIME A BIT LOW SO WILL HOLD OFF. A GOOD PORTION OF THE
UPPER LOW CONTINUES ITS EWRD TREK ACROSS CANADA SUNDAY/MONDAY
WHILE A PORTION OF THE SRN EXTENT BREAKS AWAY AND DRIFTS INTO A
POSITION OFF THE NW COAST TUESDAY. THUS ANTICIPATE SLOWLY
DECREASING WINDS SUNDAY/MONDAY ACROSS THE REGION AS RIDGE REBOUNDS
ACROSS THE GREAT BASIN. LOOKS AS IF WE COULD BE BACK INTO THE
STRONG SW FLOW ALOFT AND POTENTIAL THUNDERSTORM ACTIVITY AS EARLY
AS WEDNESDAY AS THE GFS IS SHOWING THE TROUGH EDGING INLAND ACROSS
WASHINGTON STATE. COMING WEEK LOOKS TO BE ACTIVE. STAY TUNED.
HUSTON
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
314 PM CDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 311 PM CDT THU JUL 25 2013
12Z UA ANALYSIS HAS AN 850MB LOW NORTHWEST OF LAKE SUPERIOR AND
ANOTHER IN WESTERN NEBRASKA. A WARM FRONT RAN FROM THE NEBRASKA
850MB LOW INTO NORTHWEST IOWA BEFORE TURNING SOUTH. MOISTURE WAS
POOLED IN THE NORTHERN AND CENTRAL PLAINS NEAR THE 850MB LOW AND
WARM FRONT FROM NOCTURNAL STORMS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW NEW CONVECTION HAS
DEVELOPED FROM SOUTHERN MINNESOTA INTO WESTERN WISCONSIN ALONG WITH
A PERSISTENT CLUSTER OF STORMS FROM NEBRASKA INTO NORTHEAST KANSAS.
18Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHWEST MINNESOTA INTO
SOUTHERN SOUTH DAKOTA WITH A SLIGHTLY STRONGER LOW IN EASTERN
COLORADO. A WARM FRONT RAN FROM NORTHWEST KANSAS INTO LOUISIANA. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S FROM
WISCONSIN INTO THE PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
SATELLITE AND RADAR TRENDS SHOW CONVECTION NORTH OF THE CWFA AND
WELL SOUTHWEST OF THE CWFA. THE RAP TRENDS AND OTHER MODELS OF A
POSSIBLE SCENARIO OF CONVECTION NORTHEAST AND SOUTHWEST OF THE CWFA
TONIGHT MAY BE STARTING TO PLAY OUT. HOWEVER...RADAR DOES SHOW WEAK
CONVECTION DEVELOPING ACROSS NORTHERN IOWA AND ALONG THE MISSOURI
RIVER NEAR KOMA. THE MCS TOOL SUGGESTS ISOLATED TO SCATTERED
CONVECTION MOVING/DEVELOPING ACROSS THE NORTHWEST CWFA DURING THE
EVENING AND POSSIBLY BECOMING LOOSELY ORGANIZED LATE TONIGHT.
THE SIGNAL FOR A SUBSTANTIAL MCS DEVELOPING IN THE PLAINS AND
DROPPING SOUTHEAST OVERNIGHT IS STILL THERE IN ALL THE MODELS. IF
CORRECT...THIS MCS WOULD INTERCEPT THE MOISTURE INFLOW INTO THE AREA
AND THUS LIMIT THE POTENTIAL FOR RAIN. THOSE AREAS THAT DO SEE RAIN
OVERNIGHT MAY SEE AMOUNTS RANGING FROM 0.25 TO 0.50 INCHES.
CONVECTION THAT DEVELOPS TONIGHT WILL BE ACROSS THE AREA FRIDAY
MORNING WITH THE BETTER CHANCES OVER THE NORTHEAST CWFA WHERE BETTER
FORCING EXISTS. THE RAIN WILL END FROM WEST TO EAST DURING THE DAY
AS THE FRONT MOVES THROUGH WITH LINGERING CONVECTION OVER THE
SOUTHEAST HALF OF THE CWFA BY LATE AFTERNOON. CLOUD COVER MAY
INITIALLY SUPPRESS TEMPERATURES DURING THE DAY BUT CLEARING IN THE
AFTERNOON SHOULD PUSH TEMPERATURES INTO THE 75 TO 80 DEGREE
RANGE. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
A CLOSED UPPER LOW WILL REMAIN OVER THE WESTERN GREAT LAKES THROUGH
LATE SATURDAY THEN MOVES SLOWLY EAST REACHING NORTHERN MICHIGAN BY
SUNDAY EVENING. THE COLD FRONT ASSOCIATED WITH THE UPPER LOW SHOULD BE
NEAR THE MISSISSIPPI RIVER BY 00Z SATURDAY AND EAST OF THE FORECAST
AREA BY 06Z SATURDAY WITH BEST MID/UPPER FORCING AHEAD OF THE UPPER
TROF SHIFTING EAST OF THE FORECAST AREA BY 06Z. THIS SUPPORTS
THE GOING FORECAST OF SLIGHT CHANCE POPS EAST FRIDAY EVENING THEN
DRY AFTER MIDNIGHT. THE REST OF THE WEEKEND LOOKS DRY WITH NORTH TO
NORTHWEST FLOW DOMINATING THE REGION. SATURDAY AFTERNOON/EVENING
WILL HAVE TO WATCH THE NORTHEASTERN CWFA FOR POTENTIAL DIURNAL SHRA
AS THE H5 COLD POOL MOVES THROUGH. NEAR RECORD TEMPS FOR SATURDAY
AND SUNDAY MORNING STILL LOOK ON TRACK. KEPT SATURDAYS LOWS ON THE
WARM SIDE OF GUIDANCE WITH THE POTENTIAL FOR SOME COLD AIR SC MOVING
THE THROUGH FRIDAY NIGHT. FORECAST MINS FOR SATURDAY STAY JUST ABOVE
THE RECORDS. SUNDAY LIGHTER SURFACE WINDS AND LESS OF THREAT OF
SIGNIFICANT CLOUD COVER SUPPORTS COOLER MINS THAN SATURDAY AND A
BETTER POTENTIAL OF REACHING RECORD MINS. THE COOL AIRMASS WILL
KEEP HIGHS SATURDAY AND SUNDAY IN THE LOW TO MID 70S. NORMALS HIGHS
FOR LATE JULY ARE IN THE LOW TO MID 80S.
THE GREAT LAKES REGION UPPER LOW WILL DRIFT NORTHEAST INTO EASTERN
CANADA BY MID TO LATE WEEK AS WESTERLY MID LEVEL FLOW SPREADS EAST
INTO THE CENTRAL U.S. A S/W ON THE LEADING EDGE OF THE WESTERLY
FLOW REGIME IS PROGGED TO MOVE THROUGH THE CENTRAL U.S. MONDAY AND
TUESDAY. MODELS ARE IN GOOD AGREEMENT DEVELOPING A PLAINS MCS IN
THE RETURN FLOW AHEAD OF THE S/W AND MOVING THE MCS EAST INTO THE
MID MISSISSIPPI VALLEY LATE MONDAY NIGHT OR TUESDAY. THE 12Z
GFS/GEM BROUGHT THE BULK OF THE PRECIP WITH THIS SYSTEM THROUGH IA
AND NORTHERN ILLINOIS WHILE THE 12Z ECMWF WAS A TAD SOUTH FOCUSING
MORE ON NORTHERN MO AND SOUTHERN IA INTO CENTRAL AND SOUTHERN IL.
WITH ALL OF THE MODELS HITTING SOME PART OF THE FORECAST AREA HAVE
UPPED POPS TO HIGH CHANCE OR LIKELY WITH THE HIGHEST POPS MONDAY
NIGHT. THE GFS/ECMWF SUGGEST ANOTHER S/W MOVING THROUGH BY THURSDAY
BUT THE FEATURES LOOK WEAK AT THIS TIME SO SLIGHT CHANCE OR LOW
CHANCE POPS ARE MENTIONED FOR NOW. TEMPERATURES WILL BE ON A
GRADUAL WARMING TREND THROUGH THE WEEK AND SHOULD BE BACK TO NEAR
NORMAL FOR EARLY AUGUST BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU JUL 25 2013
VFR WX WILL BE SEEN THROUGH 00Z/26 AS HIGH PRESSURE CONTINUES
MOVING EAST THROUGH THE GREAT LAKES. AFT 00Z/26 CONVECTION WILL
DEVELOP AHEAD OF AN APPROACHING COLD FRONT AND MAY EVOLVE INTO A
WEAKLY ORGANIZED SYSTEM. INITIALLY THE PROBABILITY OF A SHRA OR
TSRA HITTING A TAF SITE WILL BE LOW. AFT 03Z/26 THE CHANCES WILL
BE ON THE INCREASE. AFT 03Z/26 VFR CONDITIONS ARE FCST FOR ALL TAF
SITES BUT THE POSSIBILITY DOES EXIST FOR MVFR OR IFR CONDITIONS IF
A TSRA AFFECTS A TAF SITE. ..08..
&&
.CLIMATE...
ISSUED AT 311 PM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
CLIMATE...14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
100 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1249 PM CDT THU JUL 25 2013
SATELLITE SHOWS SOME VERY WEAK DIURNAL CU HAS DEVELOPED IN THE
PAST HOUR INDICATING THE TRIGGER TEMPERATURE FOR THERMALS HAS BEEN
ACHIEVED. TRENDS WITH THE RAP CONTINUE TO SHOW THE CONVECTIVE
TEMPERATURE CLIMBING INTO THE MID AND UPPER 80S DURING THE
AFTERNOON WHICH IS HIGHER THAN THE FCST MAX TEMPERATURES.
AN APPROACHING MCV MAY BE THE TRIGGER TO HELP INITIATE ISOLATED TO
SCATTERED CONVECTION BY LATE AFTERNOON. HOWEVER...MOST OF THE AREA
IS EXPECTED TO REMAIN DRY THROUGH SUNSET.
THE MCS AND LIFT TOOLS ARE SUGGESTING CONVECTION THAT DEVELOPS
MAY TRY TO ORGANIZE INTO A VERY WEAK MCS. IF THIS OCCURS THEN
THERE WOULD BE UPSCALE GROWTH OF THE PRECIPITATION SHIELD FOR THE
AREA. A CONCERN IS THAT THE BETTER DYNAMICS ARE NORTHEAST OF THE
AREA AND THE BETTER THERMODYNAMICS ARE ACROSS THE CENTRAL AND
SOUTHERN PLAINS. THE MCS TOOL DOES INDICATE A WELL ORGANIZED MCS
DEVELOPING IN THE PLAINS AND DROPPING SOUTH OVERNIGHT WHICH COULD
ROB NEEDED MOISTURE FOR CONVECTION OVER THE CWFA. ..08..
UPDATE ISSUED AT 1013 AM CDT THU JUL 25 2013
THERE ARE QUESTIONS ON WHETHER OR NOT CONVECTION WILL BE SEEN IN
THE CWFA PRIOR TO EVENING. THE 12Z SOUNDING HAS A CONVECTIVE
TEMPERATURE IN THE UPPER 70S. HOWEVER...RAP AND OTHER MODEL TRENDS
SHOW THIS CLIMBING INTO THE 80S AS THE DAY PROGRESSES. THE LACK OF
ANY DIURNAL CU AT THIS POINT IN THE DAY INDICATES THAT THE TRIGGER
TEMPERATURE TO GENERATE THERMALS HAS YET TO BE ACHIEVED.
THE LATE MORNING AND EARLY AFTERNOON HOURS WILL REMAIN DRY ACROSS
THE AREA. THE QUESTION BECOMES LATE AFTERNOON DURING PEAK HEATING.
THE MCS AND LIFT TOOLS FROM THE ECMWF/UKMET/GEM INDICATE DRY
CONDITIONS LATE THIS AFTERNOON AND THROUGH SUNSET. THE WRF/GFS
HAVE CONVECTION INTO THE NORTHERN/WESTERN PARTS OF THE CWFA BY
LATE AFTERNOON AND OVER MOST OF THE AREA BY SUNSET. THE RAP KEEPS
MOST OF THE AREA DRY THROUGH LATE AFTERNOON BUT BRINGS IN
CONVECTION INTO THE WESTERN PARTS OF THE CWFA JUST PRIOR TO
EVENING.
SO...WILL GO WITH THE IDEA OF KEEPING NEARLY ALL OF THE CWFA DRY
THROUGH LATE AFTERNOON WITH POSSIBLY SOME CONVECTION NORTH OF HWY
20 BETWEEN KDBQ AND KALO JUST BEFORE EVENING. DURING THE EVENING
WILL GO WITH CONVECTION DEVELOPING/SPREADING SOUTH AND EAST ACROSS
THE CWFA. ..08..
&&
.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUL 25 2013
COOL AND QUIET CONDITIONS WERE FOUND ACROSS THE AREA EARLY THIS
MORNING AS HIGH PRESSURE...REACHING FROM THE GREAT LAKES
SOUTHEAST ACROSS IL AND MO...REMAINS IN CONTROL. TEMPERATURES WERE
IN THE 50S TO LOWER 60S WITH DEWPOINTS MAINLY IN THE LOWER 50S
UNDER MOSTLY CLEAR SKIES. MORE ACTIVE WEATHER WAS FOUND ACROSS THE
PLAINS...WHERE SHORTWAVES IN THE NW FLOW WERE INTERACTING WITH
GULF MOISTURE RETURN...RESULTING IN SEVERAL THUNDERSTORM
CLUSTERS. THE LOCAL FOCUS IS ON A SHORTWAVE EVIDENT ON WV IMAGES
JUST NW OF LAKE WINNIPEG THAT IS PROGGED TO TRAVEL SOUTHEAST INTO
THE EASTERN U.S. TROUGH...DIGGING INTO A CLOSED UPPER LOW OVER THE
GREAT LAKES BY FRIDAY. IN THE PROCESS...IT WILL SWEEP A COLD FRONT
THROUGH THE FORECAST AREA EARLY FRIDAY TRIGGERING WIDESPREAD
SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
MAIN FOCUS IS ON THUNDERSTORM CHANCES LATER TODAY THROUGH FRIDAY.
TODAY...THE SURFACE HIGH WILL CONTINUE TO MIGRATE EAST...ALLOWING A
LOW LEVEL RETURN FLOW AND WARM ADVECTION. THE GFS AND WRF/NAM APPEAR
TOO AGGRESSIVE WITH THIS LOW LEVEL MOISTURE RETURN...RESULTING IN
DEWPOINTS SHOWN REACHING THE UPPER 60S TO MID 70S BY AFTERNOON
OVER EASTERN IA. THIS THEN LEADS TO HIGHER CAPES AND A FASTER
ONSET OF THUNDERSTORMS INTO EASTERN IA WELL OUT AHEAD OF THE
SURFACE COLD FRONT THIS AFTERNOON. THE MORE REASONABLE ECMWF AND
GEM LOW LEVEL MOISTURE FIELDS KEEP THE THUNDERSTORMS WELL WEST
AND NW OF THE FORECAST AREA DURING THE DAY. WITH LIGHT WINDS AND
POSSIBLE OUTFLOW BOUNDARIES UNDER A DEVELOPING SLIGHTLY DIFLUENT
FLOW ALOFT AHEAD OF THE APPROACHING SHORTWAVE...CANNOT COMPLETELY RULE
OUT SHOWERS AND THUNDERSTORMS REACHING THE FAR NW BY LATE AFTERNOON
AND WILL CARRY LOW CHANCE POPS. WITH LIGHT SOUTH TO SOUTHEAST
WINDS AND WARM ADVECTION...HAVE KEPT HIGHS IN THE UPPER 70S TO
LOWER 80S. WILL ANTICIPATE INCREASING MID AND HIGH CLOUDS FROM
UPSTREAM CONVECTION TO PREVENT EVEN WARMER TEMPERATURES.
TONIGHT INTO FRIDAY...THE PRIMARY AXIS OF GULF MOISTURE AT 850 MB SPREADS
INTO THE FORECAST AREA UNDER AN INCREASINGLY DIFLUENT FLOW ALOFT.
MODELS CONTINUE TO DEPICT THE STRONGEST UPPER FORCING AHEAD OF THE
DEVELOPING UPPER LOW TO THE NORTH ACROSS MN INTO WI...BUT DECENT
QG FORCING IS SHOWN DEVELOPING INTO THE FORECAST AREA ALONG WITH
MODEST THETAE CONVERGENCE...ESPECIALLY FROM 12Z TO 18Z COINCIDING
WITH THE ADVANCING SURFACE COLD FRONT. THERE REMAINS SOME CONCERN
IN HOW A SEPARATE STRONG SHORTWAVE IN THE PLAINS AND RESULTING
MCS MAY AFFECT THE MOISTURE FEED FURTHER NORTH AND NORTHEAST...
WHICH MAY LIMIT THE STRENGTH AND SIZE OF THE PREFRONTAL MCS THAT
WILL BE FAVORED TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT
INTO FRIDAY MORNING. WILL THUS KEEP QPF AMOUNTS OF A FEW TENTHS TO
NEAR A HALF INCH OVER THE AREA WITH LIKELY POPS CENTERED FROM LATE
TONIGHT THROUGH FRIDAY MORNING. THIS TIMING WILL NOT BE FAVORABLE
FOR SEVERE WEATHER BEYOND SOME SUB-SEVERE WIND GUSTS WITH THE
STRONGEST STORMS. MODELS ARE IN GENERAL AGREEMENT WITH THE SURFACE
FRONT CROSSING EAST OF THE MS RIVER AROUND NOON FRIDAY AND HAVE
LIMITED AFTERNOON POPS TO SLIGHT OR LOW END CHANCE POPS TO THE
WEST...WITH HIGHER CHANCES TO THE EAST THROUGH THE AFTERNOON.
CLOUDS AND HIGHER DEWPOINTS WILL HOLD TEMPERATURES IN THE 60S FOR
LOWS TONIGHT. WITH GRADUAL CLEARING FROM WEST TO EAST FRIDAY
AFTERNOON AND DEVELOPING POST-FRONTAL COOL ADVECTION W-NW
WINDS...HAVE HIGHS LIMITED TO THE LOWER TO MID 70S...WITH SOME UPPER
70S POSSIBLE IN THE SOUTH AND EAST WHERE THE FROPA WILL BE LATEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUL 25 2013
FRIDAY NIGHT... WALKED OUT PCPN CHANCES DURING THE EVENING HOURS...
WITH THE ENTIRE CWFA PCPN-FREE BY 03Z. CANADIAN HIGH PRESSURE THEN
USHERS IN COOL AND DRY CONDITIONS ON A LIGHT NNW BREEZE...WITH 850MB
TEMPS OF 6-8C COMING DOWN ACROSS THE AREA. NEAR RECORD OR RECORD COLD
TEMPERATURES ARE POSSIBLE BOTH EARLY SATURDAY MORNING AND AGAIN
SUNDAY MORNING...WITH SUNDAY HAVING THE BETTER POTENTIAL. LOWS BOTH
MORNINGS WILL BE IN THE UPPER 40S TO MID 50S. DAYTIME HIGHS ON
SATURDAY WILL STRUGGLE TO REACH THE UPPER 60S TO NEAR 70 ALONG
HIGHWAY 20...WHILE TO THE SOUTH THEY WILL INCH UPWARDS INTO THE
LOWER TO MIDDLE 70S. WITH NNW WINDS AT 10-15 MPH SAT PM...IT WILL
FEEL QUITE FALL-LIKE. SUNDAY WILL BE SLIGHTLY WARMER WITH HIGHS IN
THE LOWER 70S NORTH TO UPPER 70S SOUTH ALONG WITH LIGHTER WINDS.
MONDAY THROUGH WEDNESDAY TEMPERATURES WILL MAINLY BE IN THE MID 70S
TO LOW 80S...BUT STILL BELOW NORMAL. MODELS CONTINUE TO INDICATE
THAT THE UPPER LEVEL RIDGE WILL BREAK DOWN/MOVE EAST/ ALLOWING A
SHORT WAVE TO MOVE ACROSS THE CENTRAL PLAINS INTO MO MONDAY INTO
TUESDAY...POSSIBLY BRINGING AN MCS GENERALLY EASTWARD ALONG THE
IA/MO BORDER. THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS STILL
LOOK TO BE DURING THE MONDAY NIGHT AND TUESDAY TIME FRAME. MODEL
CONSENSUS HAS POPS FOR MON NIGHT AT 40-50 WITH 30 POP FOR
TUESDAY...WITH GENERALLY SLIGHT CHANCES BEFORE AND AFTER. AT THIS
TIME...IT APPEARS AREAS SOUTH OF I 80 HAVE THE BEST CHANCE AT SEEING
THIS ACTIVITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1249 PM CDT THU JUL 25 2013
VFR WX WILL BE SEEN THROUGH 00Z/26 AS HIGH PRESSURE CONTINUES
MOVING EAST THROUGH THE GREAT LAKES. AFT 00Z/26 CONVECTION WILL
DEVELOP AHEAD OF AN APPROACHING COLD FRONT AND MAY EVOLVE INTO A
WEAKLY ORGANIZED SYSTEM. INITIALLY THE PROBABILITY OF A SHRA OR
TSRA HITTING A TAF SITE WILL BE LOW. AFT 03Z/26 THE CHANCES WILL
BE ON THE INCREASE. AFT 03Z/26 VFR CONDITIONS ARE FCST FOR ALL TAF
SITES BUT THE POSSIBILITY DOES EXIST FOR MVFR OR IFR CONDITIONS IF
A TSRA AFFECTS A TAF SITE. ..08..
&&
.CLIMATE...
ISSUED AT 335 AM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...08
CLIMATE...14
AREA FORECAST DISCUSSION
NWS TOPEKA KS
557 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 557 PM CDT THU JUL 25 2013
BASED ON 22Z OBS AND OBJECTIVE STREAM LINE ANALYSIS..IT APPEARS AS
THOUGH THE DEEP MOIST CONVECTION IS OCCURRING WITHIN THE AREAS OF
LOW LEVEL CONVERGENCE. FOR THE IMMEDIATE FUTURE...THIS WOULD FAVOR
CONVECTION STAYING GENERALLY SOUTH OF I-70. THE NAM AND RAP SHOW A
LOW LEVEL JET PERSISTING FROM THE SOUTH AND SOUTHWEST AHEAD OF THE
SYNOPTIC COLD FRONT WITH SOME ISENTROPIC UPGLIDE. SO WHILE THE
BETTER SHORTWAVE FORCING MAY END UP SKIRTING THE SOUTHWESTERN
PORTIONS OF THE FORECAST AREA...THINK STORMS THAT FILL IN THE GAP
ALONG THE FRONT IN NEB FROM THE MO RIVER TO NORTHWEST KS SHOULD
PERSIST AND MOVE THROUGH MUCH OF NORTHEAST KS. WILL MONITOR TRENDS
FOR A LITTLE WHILE TO SEE IF IN FACT THIS IS THE CASE...BUT MAY
NEED TO ADJUST POPS UP A LITTLE FOR THE OVERNIGHT HOURS. CHANCES
FOR SEVERE WEATHER LOOK TO BE THE HIGHEST THIS EVENING WITH
REASONABLE MID LEVEL LAPSE RATES SUGGESTING SOME ELEVATED
INSTABILITY AND DEEP LAYER SHEAR AROUND 30 KTS SUPPORTIVE OF SOME
ORGANIZATIONS. HOWEVER MODELS TEND TO SHALLOW UP THE LAPSE RATES
AFTER MIDNIGHT. HOPEFULLY THIS MEANS WE WILL JUST GET SOME
BENEFICIAL RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
SEVERAL FORCING MECHANISMS COMING INTO PLAY FOR HIGH PRECIPITATION
CHANCES THROUGH EARLY FRIDAY. UPPER LEVEL JET WAS ROTATING
ANTICYCLONICALLY AROUND THE GREAT BASING RIDGE AND INTO CENTRAL
COLORADO AT 12Z WITH 40-50M HEIGHT FALLS /HIGH FOR JULY/ AT THE
WESTERN NEBRASKA VICINITY RAOBS. WEAK RIDGING AT 700MB AND 850MB
OVER THE CENTRAL PLAINS LEADING TO MODEST WARM AIR ADVECTION WITH
INCREASING MOISTURE LEADING TO SCATTERED TO WIDESPREAD BUT MOSTLY
MODEST CONVECTION IN NORTHEASTERN KANSAS TODAY. 20Z OBSERVATIONS AND
PRESSURE CHANGES SUGGEST A COLD FROM FROM EAST CENTRAL COLORADO TO
NORTHEAST NEBRASKA...WITH VEERING UPPER LEVEL WINDS ON THE
PLATTEVILLE COLORADO WIND PROFILER. MIXED LAYER CAPE REMAINS RATHER
LIMITED WITH VALUES IN THE 1000 J/KG RANGE.
WARM AIR ADVECTION TO GRADUALLY SHIFT TO SHORTWAVE AND FINALLY
FRONTAL FORCING THROUGH FRIDAY MORNING AS PRECIPITABLE WATER LEVELS
RISE. SOME QUESTIONS REMAIN IF STRONGER LOW LEVEL FORCING AND
INSTABILITY IN SOUTHWEST KANSAS WILL KEEP THE BULK OF WIDESPREAD
PRECIP TO THE SOUTH SO KEPT SOME UNCERTAINTY IN THE PRECIPITATION
CHANCES. SEVERE CHANCES SEEM SOMEWHAT LOW GIVEN MARGINAL INSTABILITY
AND ONGOING COVERAGE OF CONVECTION LIMITING FURTHER INSOLATION.
PRECIP SHOULD END BY EARLY AFTERNOON FOR THE AREA AS THE FRONT
SHIFTS SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
FRIDAY NIGHT HIGH PRESSURE WILL BUILD INTO EASTERN KANSAS AND WILL
LOWER HUMIDITY AND YIELD LOWS IN THE 50S. SATURDAY LOOKS TO REMAIN
DRY FOR THE MOST PART, BUT WITH THE APPROACH OF A MID LEVEL WAVE
DEVELOPING CONVECTION IN NEBRASKA MAY SEE SOME SHOWERS OR
THUNDERSTORMS IN NORTH CENTRAL KANSAS. HIGHS SATURDAY WILL BE BELOW
NORMAL WITH READINGS IN THE UPPER 70S TO LOWER 80S.
SATURDAY NIGHT THUNDERSTORMS DEVELOPING IN THE HIGH PLAINS WILL MOVE
SOUTHEAST IN NORTHWEST FLOW ALOFT AND MAY CLIP THE WESTERN SECTIONS
OF THE CWA AFTER 09Z SUNDAY. PRECIPITATION CHANCES WILL INCREASE
SUNDAY AS A MID LEVEL WAVE MOVES EAST OUT OF THE ROCKIES AND
CONTINUES EASTWARD IN ZONAL FLOW ACROSS THE CENTRAL PLAINS. BEST
CHANCES WILL BE FROM THE AFTERNOON SUNDAY THROUGH SUNDAY NIGHT.
ANOTHER WAVE WILL MOVE ACROSS THE STATE ON MONDAY. GOOD MOISTURE
TRANSPORT EXPECTED SUNDAY NIGHT AND MONDAY EAST OF A SURFACE TROUGH
IN THE WESTERN HIGH PLAINS. THIS MAY LEAD TO SOME LOCALLY HEAVY
RAINFALL ESPECIALLY IN EAST CENTRAL KANSAS WHERE PRECIPITABLE WATER
WILL BE THE HIGHEST. LOW LEVEL JET WILL INTERACT WITH A FRONTAL
BOUNDARY MONDAY NIGHT AND TUESDAY MORNING. BY TUESDAY AFTERNOON THE
FORCING AND MOISTURE WILL MOVE OFF TO THE SOUTHEAST AND EAST WITH
THE FRONT SO WILL KEEP MORNING SHOWERS BEFORE DRYING OUT AGAIN.
NEXT WEDNESDAY SOME WEAK FORCING MAY BRING A SMALL CHANCE OF
THUNDERSTORMS TO THE AREA AS THEY ADVECT IN FROM THE WEST IN A NEARLY
ZONAL FLOW ALOFT. BETTER CHANCES COME NEXT THURSDAY AS MOISTURE
RETURNS AHEAD OF A DEVELOPING SURFACE TROUGH IN THE HIGH PLAINS WITH
AN MCS DEVELOPING IN THE HIGH PLAINS AND MOVING INTO EASTERN KANSAS.
TEMPERATURES WILL WARM FROM THE 80S TO LOWER TO MID 90S FROM MONDAY
THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 557 PM CDT THU JUL 25 2013
NO REAL CHANGE IN FORECAST THINKING AS HIRES MODELS CONTINUE TO
SHOW THE BEST TIMING FOR CONVECTION TO MOVE THROUGH THE TERMINALS
BETWEEN 07Z AND 13Z. NAM AND RAP CONTINUE TO SHOW THE POTENTIAL
FOR MVFR CIGS WITH THE CONVECTION. ONE MINOR CHANGES WAS TO HANG
ONTO THE MVFR CIGS A LITTLE LONGER INTO THE MORNING UNTIL THE LOW
LEVEL DRY AIR PUSHES THE RH SOUTH.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...65
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1142 AM CDT THU JUL 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 329 AM CDT THU JUL 25 2013
AT 6Z...WPC HAD A COLD FRONT ANALYZED FROM A SFC LOW OVER THE
ARROWHEAD BACK SW TO THE AXN AREA AND BACK ACROSS NRN SODAK. THE
FRONT SITS WITHIN A RATHER BAGGY PRESSURE PATTERN...WITH MULTIPLE
BOUNDARIES HANGING AROUND BETWEEN MN AND THE DAKOTAS. BASED ON THE
WIND FIELD...THE WPC ANALYZED FRONT LOOKS TO HAVE THE MAIN WARM
SECTOR WITH SRLY WINDS TO THE SOUTH/EAST OF IT...WITH VERY LITTLE
WINDS BEHIND IT. THE MAIN WIND SHIFT TO THE NW HANGS BACK ACROSS
NW NODAK AND LOOKS TO EVENTUALLY HOOK UP WITH THE MAIN
BOUNDARY...BUT THAT DOES NOT LOOK TO HAPPEN UNTIL TONIGHT.
OUT AHEAD OF THIS FRONT...PRESENCE OF 20KT WRLY LLJ AND ASSOCIATED
WEAK WAA AND MOISTURE TRANSPORT HAS ALLOWED A FEW SHOWERS/STORMS
TO PERSIST THROUGH THE NIGHT. ENVIRONMENT OUT HEAD OF THESE
SHOWERS IS PRETTY HOSTILE IN TERMS OF DRYNESS AND LACK OF
INSTABILITY AND EXPECT THESE SHOWERS TO FADE AWAY TO NOT MUCH MORE
THAN CLOUDS AND SPRINKLES THIS MORNING.
FOR THIS AFTERNOON...HI-RES CAMS FROM THE HOPWRF TO THE HRRR AND
NMMS/ARWS ARE ALL IN FAIRLY GOOD AGREEMENT ON HANDLING OF
CONVECTION...SO FOLLOWED THEM CLOSELY IN DRAWING POPS FOR THIS
AFTERNOON/EVENING. BASED ON THAT...CURRENT THINKING IS THAT BY
18Z...COLD FRONT JUST NOW ENTERING THE NW MPX CWA WILL BE NEAR A
RWF/MSP/RCX LINE. DEWPS IN THE LOW TO MID 60S ARE EXPECTED TO BE
COMMON OUT AHEAD OF THE FRONT AND WITH DAYTIME HEATING...MODELS IN
GOOD AGREEMENT WITH GENERATING AROUND 1500 J/KG OF MLCAPE IN THE
WARM SECTOR. WITHIN THIS PRE-FRONTAL ENVIRONMENT...CAMS GENERATE
CONVECTION ALONG SOUTH OF THE RWF/MSP/RCX LINE PRETTY QUICKLY IN
THE 18Z TO 20Z TIME-FRAME...AND SLOWLY SAG ACTIVITY SOUTH THROUGH
THE EVENING...WITH MOST ACTIVITY OUT OF THE MPX AREA BY 6Z.
CONVECTION IS FORECAST TO BE MOST WIDESPREAD ACROSS SRN MN...WHICH
MAKES SENSE WHEN LOOKING AT H85 MOISTURE TRANSPORT FROM THE
DETERMINISTIC MODELS WHICH SHOW SRN MN GETTING UNDER THE MOST
INFLUENCE FROM A SWRLY ORIENTED LLJ THAT WILL BE COMING UP OUT OF
NEB AND INTO IA.
FROM THE SEVERE PERSPECTIVE...VERY WEAK SFC WINDS AND TOUGH TO PIN
DOWN BOUNDARY SHOULD RESULT IN A NEARLY ZERO TORNADO THREAT.
HOWEVER...WITH A BETTER THAN 50KT MID LEVEL DROPPING SOUTH INTO NRN
MN THIS AFTERNOON...THIS WILL RESULT IN AMPLE DEEP LAYER SHEAR FOR
THUNDERSTORM ORGANIZATION...ALONG WITH SUPERCELLS...HENCE THE
NEARLY ZERO AND NOT COMPLETELY ZERO CHANCE FOR A TORNADO.
INSTEAD... FREEZING LEVELS DOWN AT A FALL LIKE 10K FT OR LESS
ALONG WITH STEEP LOW LEVEL LAPSE RATES WILL KEEP THE MAIN RISKS AS
A FEW STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
NW OF THE RWF/MSP/RCX LINE...PRECIP IS LOOKING LIKE IT MAY BE HARD
TO COME BY...WITH THE ONLY HOPE FOR PRECIP THIS AFTERNOON IN THESE
LOCATIONS BEING THAT SOMETHING CAN GET GOING ALONG WITH WIND SHIFT
BOUNDARY TO NW WINDS THAT WILL BE TRAILING THE MAIN FRONT.
FOR TONIGHT...LIKELY TOO SLOW IN CLEARING OUT PRECIP BASED ON THE
CAMS...BUT OTHER THAN THAT...GOOD AGREEMENT ON A SIGNIFICANT SURGE
OF COLD AIR /FOR JULY STANDARDS/ INFILTRATING THE AREA IN THE WAKE
OF THE FRONT...SETTING THE STAGE FOR THE TASTE OF SEPTEMBER OVER
THE WEEKEND.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 329 AM CDT THU JUL 25 2013
MUCH MORE TRANQUIL CONDS ARE ON TAP FOR THE END OF THIS WEEK INTO
THE FIRST PORTION OF NEXT WEEK...ALBEIT NOTICEABLY COOLER AND
DRIER.
SFC CDFNT WILL HAVE JUST ABOUT EXITED THE WFO MPX CWFA BY DAYBREAK
FRI MRNG WHILE ITS PARENT LOW PRES CENTER ROTATES THRU NRN WI.
ALOFT...A CUTOFF H5 LOW WILL TRAIL THE SFC LOW THRU NRN MN THEN
BECOME STALLED OUT OVER THE NRN GREAT LAKES FRI NIGHT THRU SUN
NIGHT. THERE WILL BE SOME WEAK SHWRS SPARKED BY SHORTWAVE
DISTURBANCES ROTATING ARND THE UPR LVL LOW FRI. HOWEVER...MUCH
DRIER CONTINENTAL AIR WILL BE PULLED INTO THE REGION WITHIN THE
PROLONGED NWLY FLOW THRU THE WEEKEND. IN ADDITION...TEMPS WILL
BECOME MUCH COOLER DURING THE WEEKEND. H85 TEMPS WILL DROP TO THE
5-7 DEG C RANGE...WHICH TRANSLATING TO THE SFC DESPITE FULL SUN
WILL ONLY PRODUCE HIGH TEMPS IN THE 60S TO ARND 70. AS FOR
OVERNIGHT LOWS...WITH SFC HIGH PRES SHIFTING ACRS TO ALLOW WINDS
TO SETTLE DOWN AT NIGHT...LOWS WILL DROP INTO THE 40S AWAY FROM
THE TWIN CITIES METRO.
TEMPERATURES SLOWLY RECOVER DURING THE FIRST PORTION OF NEXT WEEK
AS THE SFC HIGH SHIFTS E OF THE REGION...ALLOWING A SLY RETURN
FLOW TO DEVELOP ON THE BACKSIDE OF THE HIGH. AS TEMPERATURES
RISE...SO WILL DEW-POINTS AND HENCE HUMIDITY LEVELS. IN ADDITION...
ANOTHER FRONTAL SYSTEM IS EXPECTED BETWEEN MON-TUE WHICH WILL
FORCE THE RE-INTRODUCTION OF SMALL CHCS FOR PRECIP IN THE FIRST
PORTION OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1127 AM CDT THU JUL 25 2013
MAIN AVIATION CONCERN IS COVERAGE OF THE SHRA/TSRA THIS AFTN ONCE
THE CAP BREAKS AND AN AREA OF SHRA/TSRA BETWEEN TWO SYSTEMS ACROSS
SD/WC MN BEGIN TO MERGE. INITIALLY...IT SEEMS THAT THE BEST
MOISTURE CONVERGENCE WILL BE SOUTH OF THE MAIN MPX TAF
TERMINALS...WITH THE EXCEPTION OF RWF/EAU WHERE DAYTIME HEATING
AND A MORE SW FLOW WILL AID IS BETTER TSRA ACTIVITY AND COVERAGE.
ELSEWHERE...ESPECIALLY NORTH OF MSP TO RNH...ACTIVITY WILL LIKELY
BE ISOLATED IN TERMS OF TSRA WITH MORE SHRA DURING THE FIRST 3-6
HRS. ONCE THE MAIN CAA BEGINS THIS AFTN ACROSS WC MN...THE
SHRA/TSRA ACTIVITY SHOULD MOVE SOUTH ACROSS MOST OF MPX AIRPORT
TERMINALS. WILL CONTINUE WITH A TEMPORARY PERIOD OF 4-6SM SHRA
WITH VCTS AT RWF BETWEEN 18-20Z. THIS IS SIMILAR TO EAU BUT A BIT
LATER. AFT 06Z...MOST OF THE SHRA SHOULD BE SOUTH OF MN...BUT DO
HAVE SOME CONCERNS WITH REDEVELOPMENT OF -SHRA ALONG THE LEADING
EDGE OF THE STRONGEST CAA THIS EVENING. LATER SHIFTS WILL NEED TO
MONITOR ACTIVITY ACROSS NW MN AND WHETHER THIS WILL HOLD ON DURING
THE AFTN/EVENING. WINDS WILL INCREASE BY FRIDAY MORNING FROM THE
NW/NNW AND BECOME GUSTY BY 15-18Z. MVFR CIGS ARE ALSO LIKELY BY
9-15Z ACROSS AXN/STC/RNH.
KMSP...
THE NEXT 6 HRS FORECAST IS BASED ON ACTIVITY ACROSS WC MN AND
WHETHER THIS ACTIVITY WILL INTENSIFY...OR REDEVELOP FURTHER TO
THE SOUTH AND KEEP THE BULK OF THE HEAVIER TSRA SOUTH OF MSP
TERMINAL. THERE IS ENOUGH CERTAINTY THAT VCTS WILL OCCUR AT MSP.
TIMING AND HOW STRONG REMAINS THE PROBLEM. WILL CONTINUE WITH VCTS
BUT TEMPORARY OF 5-6SM SHRA AND CIGS DROPPING TO LOW END VFR. SOME
CONCERNS OF REDEVELOPMENT OF VCSH AFT 00Z WITH THE MAIN CAA
STARTS. BUT WILL LEAVE THIS ALONE FOR THE SHORT TERM. GUSTY WINDS
WILL LIKELY DEVELOP BY MID/LATE FRIDAY MORNING AS MUCH COOLER AIR
USHERS IN FOR LATE JULY. SOME MVFR CIGS ARE POSSIBLE DURING THE
MORNING...BUT NOT ENOUGH CONFIDENCE TO BEGIN WITH MVFR CIGS...BUT
KEEP SCT020 CIGS OF 3.5K REMAINING IN THE TAF.
/OUTLOOK FOR KMSP/
FRI EVENING...VFR. WINDS NW 15G25 KTS.
SAT...VFR. WINDS NW 10G20 KTS.
SUN...VFR. WINDS LGT AND VRB.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
345 PM CDT Thu Jul 25 2013
.SHORT TERM...(This Evening through Friday)
Issued at 345 PM CDT THU JUL 25 2013
A weak short wave trough moving through the northwest flow will
bring a few showers and thunderstorms overnight. The main challenge
will be deciding how much of the area will stay intact as it moves
from Kansas and Nebraska towards Missouri. The HRRR is a little slow
but has the conceptual idea of pattern right so will follow that for
the first period. As the sun sets some of the convection may
diminish and most concentrated area will likely pass to the
southwest of the CWA anyway. Still, the NAM is showing some mid
level lapse rates around 6 K/KM and around 1.5 inches of
precipitable water over extreme eastern Kansas and western Missouri
with lower values to the east. Given the dry conditions at the
surface confidence is still fairly low for any widespread QPF
tonight.
Tomorrow...chances of precipitation will decreas across the area as
short wave trough exits that area. Still will be in northwest flow
and relative humidities drop through the day such that by evening
conditions should be cool and dry with light winds overnight.
Saturday will be picture perfect with low humidities and high
temperatures in the 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 345 PM CDT THU JUL 25 2013
For the last half of the forecast, below normal temperatures with a
decent chance at rain will be the dominate conditions. Pattern
across the country over the weekend will be dominated by a locally
northwest flow, within the larger amplified pattern in place
across the nation thanks to a cutoff low that will develop over the
Great Lakes this weekend. However, the low is not expected to hang
out for long as by late in the weekend it will have migrated far
enough to the northeast to allow the prevailing flow across the
Plains to return to a zonal pattern.
Over the later half of the weekend, temperatures will remain rather
cool for late July, with highs from the 70s into the 80s. These
pleasant conditions should persist into the work week even as the
zonal flow allows temperatures to moderate up some going into the
work week. Ultimately, the thermal ridge will remain to our west as
the flow adjusts through the beginning of the work week, thus
sparing the region from the oppressively hot temperatures more
typical of late July.
Otherwise, our precipitation chances for early in the work week are
looking rather decent, though persistence considerations leaves
confidence lower than the POPs advertised. As the pattern
flattens out across the nation Sunday night into Monday a shortwave
trough will shift across the center of the nation. Medium range
models have been keying on this shortwave for precipitation, though
the latest runs have slide the periods of focus for the storms from
Sunday night more fully into Monday and Tuesday over the last
several runs. Models continue to robustly advertise storms in these
early work week periods as isentropic lift and moisture transport
spread into Kansas and Missouri, therefore have kept going with
likely POPs for Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1230 PM CDT THU JUL 25 2013
A small cluster of showers with a few thunderstorms embedded will
move towards the terminals this afternoon. This area is about 50
miles wide at present and is mainly over Atchison and Jefferson
Counties in Kansas. The area may stay intact or weaken over the next
couple of hours as it moves towards KMCI. Therefore have put VCTS in
the TAFS beginning around 19 UTC for KMCI and KSTJ...and 20 UTC for KMKC.
Low confidence in the tempo group for this evening but with a weak
wave moving through and some modest instability and low level
moisture will go with tempo group until after sunset. Tomorrow
morning some of the guidance suggests some less than VFR conditions
but believe that the air will be drier behind the weak wave so will
keep a VFR deck in around 5000 feet.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Adolphson
LONG TERM...Cutter
AVIATION...Adolphson
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1254 PM CDT THU JUL 25 2013
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
SURFACE COLD FRONT EXTENDING FROM SOUTHEASTERN SOUTH DAKOTA TO
CENTRAL NEBRASKA WILL CONTINUE TO DROP SOUTHEASTWARD THROUGH
EASTERN NEBRASKA THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO OCCUR ALONG AND AHEAD OF THE FRONT MAINLY AFTER
20Z TO 06Z ACROSS EASTERN NEBRASKA AND WESTERN IOWA. SOME STORMS
MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS. MVFR CONDITIONS
ARE FORECAST IN SOME OF THE STORMS. VFR CONDITIONS ARE EXPECTED
AFTER FRONTAL PASSAGE AFTER 06 TO 09Z.
SMITH
&&
PREV DISCUSSION... /ISSUED 305 AM CDT THU JUL 25 2013/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TONIGHT PRIMARY FORECAST CHALLENGE
.AT LEAST IN SHORTER TERM.
MODELS ARE VERY SIMILAR IN DROPPING A SEVERAL PIECE BUT RATHER SHARP
CANADIAN TROUGH...CURRENTLY MOVING SE ACROSS SASK...ALONG U.S.
BORDER TODAY BEFORE CLOSING LOW PRESSURE OFF OVER UPPER GREAT
LAKES REGION FRIDAY. THIS IN TURN WILL SET THE STAGE FOR DECENT
MOIST ADVECTION CENTERED IN H8-H7 LAYER ACROSS FORECAST AREA TODAY
BEFORE UPPER SYSTEM SENDS COLD FRONT ACROSS FA TONIGHT. MODELS
DIFFER...IN SOME CASES SIGNIFICANTLY...IN STRENGTH OF ANY LEAD
WAVES IN NWRLY FLOW ON SW SIDE OF STRONGER UPPER SYSTEM...FRONTAL
TIMING AND QPF GENERATED OVER FA.
EARLY MORNING STLT SHOWED SEVERAL OF THESE LEAD WAVES...ONE OVER
SWRN NEBR AND POSSIBLY TWO DROPPING SE THROUGH ERN MT WITH
CONVECTION TIED INTO EACH OF THEM. MT WAVES COULD APPROACH NWRN
ZONES THIS MORNING WHILE SWRN NEBR ONE POSSIBLY APPROACHES SWRN
ZONES. QUESTION IS WHETHER CONVECTION WILL DECREASE
DIURNALLY...I.E...THRU MIDDAY...BEFORE STRENGTHENING LATE THIS
AFTN/EARLY EVENING. 06Z RAP DEVELOPED PRECIP EAST OVER MUCH OF
THE FA THROUGH EARLY AFTN...BUT IT ALSO WARMED TEMPERATURES INTO
LOWER 90S BY NOON. THAT LOOKED TOO WARM GIVEN UPSTREAM CIRRUS IF
NOTHING ELSE. 00Z NAM ALSO REMAINED AGGRESSIVE IN QPF GENERATION
.BUT AT LEAST SOMEWHAT CONSISTENT...ALTHOUGH IT WAS NOTED THAT
06Z RUN DELAYED BULK OF PRECIP 03HRS OR SO. GFS KEPT A WEAK CAP
OVER MANY LOCATIONS TODAY AND HAD A GENERAL MINIMUM IN FORECAST
PRECIP OVER AREA THROUGH TONIGHT.
ALL OF THAT SAID...GENERALLY INCREASED POPS FROM NW TO SE OVER NRN
ZONES AND W TO E ACROSS THE S TODAY/EARLY TONIGHT WITH HIGHEST
POPS NERN ZONES AND LOWEST ACROSS CNTRL ZONES ACCOUNTING SOMEWHAT
FOR A MIDDAY DECREASE. LEANING MORE TOWARD SLOWER GFS WITH REGARDS
TO FRONTAL TIMING AND H7-H5 QG FORCING...WHICH CONTINUED MUCH OF
TONIGHT...LINGERED POPS AFTER 06Z MORE SO THAN NAM WOULD SUGGEST.
IF CONVECTION CONTINUES INCREASING ACROSS FORECAST AREA THROUGH
THIS AFTERNOON...FORECAST TEMPERATURES COULD BE ON WARM SIDE. BUT
GENERALLY MADE NO CHANGES FROM PREVIOUS FORECAST WHICH WAS IN
LINE WITH GUIDANCE. WITH MOIST ADVECTION AND FORECAST
TEMPS...MODEST INSTABILITY WILL BE IN PLACE OVER AREA LATER
TODAY/EARLY TONIGHT TO GO ALONG WITH MODEST SHEAR NRN
ZONES...ESPECIALLY IF BULK OF CONVECTION DOESN/T ARRIVE TIL LATE
DAY. SO SEVERE STORMS ARE POSSIBLE...MAINLY NORTH.
HOWEVER...H7-H5 LAPSE RATES OVER THE AREA ARE NOT PARTICULAR STEEP
SO COVERAGE COULD BE MORE TIED IN WITH DAYTIME HEATING AND
COVERAGE THROUGH THE EVENING SOMEWHAT LIMITED FARTHER S.
COOLER WEATHER THEN IN STORE FOR FRIDAY AND SATURDAY AS COOLER H85
TEMPS SPREAD SE ACROSS MO VALLEY WITH AROUND 10 DEG C AIR MOVING
OVER NERN ZONES. WITH FA ON SW SIDE OF POLAR JET NE...DISTURBANCES
IN UPPER FLOW COINCIDING WITH MOISTURE ATTEMPTING TO RETURN COULD
SPREAD CLOUDS IF NOT SHOWERS/TSTMS INTO PARTS OF THE AREA...MAINLY
WRN ZONES. THAT OF COURSE WOULD IMPACT TEMPERATURES IF IT WOULD
OCCUR. HOWEVER...FOR NOW KEPT FORECAST DRY THROUGH SATURDAY WITH
CLOUDS HAVING MINIMAL INFLUENCE. HIGHS MOSTLY IN UPPER 70S WITH
SOME LOWER 80S YET LINGERING SOUTH ON FRIDAY. DID TRIM LOWS SOME
AS SAT/SUNDAY MORNINGS AS DECENT AGREEMENT AMONG MODELS IN
LOWERING DWPTS INTO UPR 40S/LOWER 50S MOST LOCATIONS.
PRECIP CHANCES APPEAR THEY WILL INCREASE FROM W TO EAST...POSSIBLY
AS EARLY AS SAT NIGHT/SUNDAY BUT ESPECIALLY MON/MONDAY NIGHT AS
UPPER FLOW TURNS MORE WRLY AS UPPER TROUGH STARTS SHIFTING E. THIS
IN TURN WILL ALLOW TROPICAL MOISTURE BACK TOWARD AREA WITH ANOTHER
UPPER TROUGH TO FORECAST TO SHIFT ACROSS PLAINS. ALTHOUGH 00Z
ECMWF REMAINED CONSISTENT IN MOVING AN MCS ACROSS FA ON
MONDAY...KEPT POPS IN EXTENDED JUST BELOW LIKELY CATEGORY FOR NOW.
UPPER RIDGE ATTEMPTS TO REBUILD OVER CENTRAL PLAINS TOWARD MIDWEEK
WHICH COULD ALLOW TEMPS TO RETURN CLOSER TO AVERAGE. BUT PROGRESS
OF SUCH COULD BE HINDERED BY LINGERING CLOUDS/PRECIP FROM MONDAY-
TUESDAY SYSTEM OR POSSIBLY IN LATER PERIODS AS MORE ENERGY DIVES
SEWD OUT OF CANADA.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
321 PM MDT THU JUL 25 2013
.DISCUSSION...ENHANCED NW TO SE STEERING FLOW IN PLACE ACROSS ROUGHLY
THE NE HALF OF THE FORECAST AREA TODAY RESULTING IN MUCH FASTER
STORM MOTIONS BUT ALSO GREATER STORM ORGANIZATION/STRUCTURE. THE
SW HALF CONTINUES UNDER THE INFLUENCE OF AN UPPER LEVEL COL REGION
BETWEEN TWO HIGH CENTERS...PRIMARY ONE OVER NW AZ AND A SECONDARY
CENTROID WEST OF THE TX BIG BEND REGION. AT LEAST TWO WELL-
DEFINED MESOSCALE CONVECTIVE VORTICES IN THE VICINITY OF OUR
SOUTHERN BORDER REGION BUT HOW THEY WILL MANIFEST THEMSELVES WITHIN
THE NEXT FEW HOURS AS DAYTIME HEATING/INSTABILITY PEAK IS UNCLEAR.
REGION OF VERY FAVORABLE 300-400 MB DEFORMATION IS DEFINITELY
CONTRIBUTING TO AN ACTIVE CROP OVER THE WEST AND A BIT FARTHER
NORTH THAN WHAT MODELS SUGGESTED.
WILL CONTINUE TO FOCUS THE BEST POPS ACROSS THE NC/NE AND
EVENTUALLY EC ZONES AS WELL AS THE WCC/SW. SHORT- WAVE TROUGH
BRUSHING NORTHEAST NEW MEXICO THROUGH THE REMAINDER OF THE
AFTERNOON WILL CONTINUE TO BOOST STORM COVERAGE/INTENSITY THERE
WITH A FEW STRONG/SEVERE STORMS A GOOD BET. SEWD-MOVING AND
GRADUALLY EXPANDING/DEEPENING COLD POOLS WILL LIKELY TOUCH OFF NEW
CONVECTION FARTHER SOUTH...AND THE LATEST HRRR STRONG SUGGESTS A
LARGER CONVECTIVE COMPLEX TAKING SHAPE ACROSS PARTS OF EC PLAINS.
EARLIER EXPANSION OF THE FLASH FLOOD WATCH NOT LOOKING GREAT THUS
FAR...BUT WILL LET RIDE FOR EVENING CREW TO REEVALUATE.
IN WAKE OF THE SUBTLE SHORT-WAVE FEATURE THIS AFTERNOON/EARLY
EVENING... MODELS ADVERTISE A NEW BACKDOOR FRONTAL BOUNDARY TO
SLOWLY MAKE ITS WAY SOUTH AND EVENTUALLY WEST DURING THE DAY
FRIDAY. SOMEWHAT DRIER/MORE STABLE AIR MASS EXPECTED TO LIMIT
CONVECTION ACROSS MUCH OF THE NE/EC PLAINS THOUGH LOW LEVEL UPSLOPE
SHOULD PROVE BENEFICIAL FOR THE EAST SLOPES OF THE SANGRES.
OTHERWISE...UPPER HIGH CENTERED TO OUR NORTHWEST SLOWLY BUILDS OUR
DIRECTION. THOUGH NOT AS ROBUST AS TODAY...A NW TO SE STEERING
FLOW WILL CONTINUE FAVOR THE HIGH PLAINS ON FRIDAY WITH THE
COMBINATION OF DEEPER MOISTURE/VERY WEAK STEERING FLOW FAVORING
THE WC/SW ZONES FOR PERSISTENT FLASH FLOOD THREAT.
THE UPPER HIGH WILL CONTINUE TO PRESS SOUTHWARD INTO THE WEEKEND
AND ESPECIALLY EARLY NEXT WEEK WITH A MARKED TREND TOWARD A DRIER
CONDITIONS BENEATH ENHANCED WEST TO EAST FLOW REGIME. IN OTHER
WORDS THE WESTERLIES LOOK TO RETURN AND STRONGLY SO ACROSS
NORTHERN AREAS OF THE STATE DURING THE EXTENDED.
&&
.FIRE WEATHER...
A FAIRLY DYNAMIC DAY ON TAP AS A SHORTWAVE CAUGHT IN NORTHWEST FLOW
MOVES OVER THE CENTRAL AND SOUTHERN ROCKIES. STORMS HAVE FIRED UP
AHEAD OF THIS SHORTWAVE ACROSS NORTH CENTRAL AND NORTHEAST AREAS.
RESIDUAL MONSOONAL MOISTURE CAUGHT WITHIN A DEFORMATION ZONE OR
LIFTING ZONE IS FOUND ELSEWHERE. STORMS ARE GRADUALLY FIRING UP
WITHIN THIS ZONE. EXPECTING ANOTHER ACTIVE THUNDERSTORM DAY LASTING
THROUGH THE EVENING HOURS.
MODELS HAVE BEEN SHOWING SOME DRYING ACROSS THE NORTHWEST THIRD ON
FRIDAY. A BACK DOOR COLD FRONT WHICH WILL HAVE PUSHED INTO THE
EASTERN PLAINS TONIGHT FOLLOWING THE DISTURBANCE OR SHORTWAVE
PASSAGE WILL PROVIDE THE MAIN FOCUS FOR STORMS DURING THE AFTERNOON
AND EVENING FRIDAY. AS OF RIGHT NOW...THE MAIN FOCUS AREA WILL BE
FOUND ACROSS ZONE 109 EXTENDING NORTHEASTWARD TO THE SANGRE DE
CRISTOS. A MORE STABLE AIRMASS STILL LOOKS TO BE A LIMITER FOR
WETTING THUNDERSTORMS ACROSS THE FAR EASTERN PLAINS DURING THE
AFTERNOON HOURS. OVERALL...COVERAGE LOOKS TO BE SLIGHTLY LESS WITH
SLIGHTLY LESS HUMIDITY VERSUS TODAY.
MODELS ARE CONVERGING ON PLACING THE UPPER HIGH CENTER OVER FAR
SOUTHERN NM AND NORTHERN MEXICO ON SATURDAY. THE STEERING FLOW FOR THE
STORMS WOULD TURN MORE WEST TO EAST AS A RESULT. MOISTURE IS STILL
PLENTIFUL ACROSS ARIZONA SO THIS COULD ACTUALLY RESULT IN AN UPTICK
IN SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING. THIS
INCLUDES THE ENTIRE EASTERN PLAINS DUE TO STEERING FLOW
CONSIDERATIONS. WETTING RAIN AND ABUNDANT CLOUD COVER WITH AN UPTICK
IN HUMIDITY IS A PRETTY GOOD BET.
THE CENTER OF THE UPPER HIGH SHOULD REMAIN OVER NORTHERN MEXICO ON
SUNDAY. BY THIS POINT...A FAIRLY STRONG SURFACE LOW FOR THIS TIME OF
YEAR IS EXPECTED TO DEVELOP TO THE LEE OF THE CENTRAL MOUNTAINS AND
THE WESTERLY FLOW ALOFT SHOULD ALSO INCREASE SOME. MODELS VARY
SOMEWHAT ON THE STRENGTH BUT THEY STILL POINT TOWARDS A DRIER
WESTERLY FLOW. BY THIS POINT...ARIZONA IS EXPECTED TO SEE A DOWNTURN
IN MOISTURE VALUES THUS DRIER AIR SHOULD EVENTUALLY ENTRAIN ACROSS
NEW MEXICO AS A RESULT. THIS WILL NOT TOTALLY ELIMINATE THUNDERSTORM
DEVELOPMENT BUT WOULD REDUCE THE COVERAGE AND WETTING RAIN FOOTPRINT
SOME. THE GFS AND ECMWF MODELS PAINT THE MAIN FOCUS AREA FOR WETTING
RAIN ACROSS THE NORTHERN TIER OF THE STATE AND SPECIALLY ACROSS
NORTH CENTRAL AND NORTHEAST AREAS. DID BUMP UP WIND SPEEDS WHICH
LOOK MORE LIKE MID JUNE SO WILL CONTINUE TO MONITOR THIS SCENARIO.
THE LATEST GFS AND ECMWF PAINT A FURTHER REDUCTION IN SHOWER AND
THUNDERSTORM COVERAGE ON MONDAY AS DRIER AIR INFILTRATES THE STATE
FROM THE WEST. MODELS ARE VERY BULLISH ON PAINTING VERY LITTLE
CONVECTION SO WILL BE INTERESTING TO SEE WHAT TURNS OUT. EITHER
WAY...EXPECTING DRIER AND WARMER CONDITIONS EARLY NEXT WEEK. AS THE
WEEK PROGRESSES...EXPECTING SOME SORT OF MOISTURE SEEPAGE AS THE
UPPER HIGH TRIES TO BUILD NORTHWARD AND PERHAPS EASTWARD. THE SEEPAGE WOULD
MOST LIKELY COME ALONG THE CONTINENTAL DIVIDE AS WELL AS VIA A WIND
SHIFT ACROSS THE NORTHEAST. EITHER WAY...WETTING THUNDERSTORMS LOOK
TO BE MORE ON THE MINIMAL KIND THROUGH THE EARLIER HALF OF NEXT
WEEK. PERHAPS INCREASING A BIT MORE THE LATTER HALF OF NEXT WEEK IF
THE HIGH SHIFTS OVER TEXAS. SOME OF THE MODELS ARE SHOWING THIS
TREND. IT SHOULD BE POINTED OUT THAT A 3 TO 4 DAY DOWNTREND IN
WETTING THUNDERSTORMS TYPICALLY OCCURS DURING THE MONSOON MOST YEARS
SO NOTHING TOO OUT OF THE ORDINARY BUT WILL KEEP AN EYE ON
SIGNIFICANT TRENDS...WHETHER THEY BE MOISTENING OR DRYING AS WE GO
FORWARD.
&&
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 64 94 65 91 / 20 20 20 40
DULCE........................... 51 86 53 84 / 30 30 50 50
CUBA............................ 55 87 54 84 / 30 40 50 60
GALLUP.......................... 58 88 59 84 / 50 40 30 40
EL MORRO........................ 53 80 54 77 / 40 40 40 60
GRANTS.......................... 58 85 58 81 / 30 40 40 50
QUEMADO......................... 57 82 57 80 / 50 40 30 60
GLENWOOD........................ 60 85 60 84 / 60 40 30 50
CHAMA........................... 50 77 50 74 / 30 40 60 60
LOS ALAMOS...................... 60 81 59 80 / 30 40 50 50
PECOS........................... 57 75 56 75 / 50 50 60 50
CERRO/QUESTA.................... 53 79 53 78 / 30 50 50 40
RED RIVER....................... 46 68 45 68 / 50 60 70 50
ANGEL FIRE...................... 43 72 43 72 / 40 60 70 50
TAOS............................ 52 83 53 82 / 30 40 40 40
MORA............................ 53 74 53 75 / 60 60 60 50
ESPANOLA........................ 59 87 59 85 / 30 30 40 30
SANTA FE........................ 59 80 58 79 / 40 40 50 50
SANTA FE AIRPORT................ 61 84 60 83 / 40 40 40 40
ALBUQUERQUE FOOTHILLS........... 67 87 66 85 / 40 40 40 40
ALBUQUERQUE HEIGHTS............. 68 88 67 87 / 30 30 40 40
ALBUQUERQUE VALLEY.............. 67 90 66 88 / 30 30 40 30
ALBUQUERQUE WEST MESA........... 66 92 65 90 / 30 30 40 30
LOS LUNAS....................... 66 89 65 87 / 40 30 40 30
RIO RANCHO...................... 66 92 65 90 / 30 30 40 40
SOCORRO......................... 66 93 66 92 / 50 40 30 40
SANDIA PARK/CEDAR CREST......... 60 85 59 84 / 50 40 40 50
TIJERAS......................... 61 83 60 81 / 40 40 40 40
MORIARTY/ESTANCIA............... 59 82 57 81 / 40 40 40 50
CLINES CORNERS.................. 58 79 57 78 / 60 50 40 50
GRAN QUIVIRA.................... 60 83 59 81 / 40 50 30 50
CARRIZOZO....................... 64 85 63 83 / 40 40 30 50
RUIDOSO......................... 57 76 55 75 / 50 50 30 60
CAPULIN......................... 55 77 55 81 / 60 40 30 40
RATON........................... 58 82 57 85 / 60 60 30 30
SPRINGER........................ 58 83 57 85 / 60 50 30 30
LAS VEGAS....................... 56 78 56 79 / 60 50 40 50
CLAYTON......................... 64 84 61 87 / 40 10 10 20
ROY............................. 62 81 61 83 / 60 40 30 30
CONCHAS......................... 67 87 66 89 / 60 20 30 20
SANTA ROSA...................... 66 87 65 86 / 60 30 30 30
TUCUMCARI....................... 70 90 68 92 / 60 10 10 20
CLOVIS.......................... 67 88 63 88 / 40 20 10 10
PORTALES........................ 67 88 64 88 / 40 20 10 10
FORT SUMNER..................... 69 88 67 87 / 60 20 10 20
ROSWELL......................... 70 93 69 90 / 40 20 20 20
PICACHO......................... 63 86 62 85 / 40 30 30 40
ELK............................. 60 79 58 77 / 40 40 40 40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1204 PM MDT THU JUL 25 2013
.UPDATE...
SHORT-WAVE TROUGH TO BRUSH NC/NE AREAS OF THE STATE EARLY TODAY
AND ALREADY SEEING STRONG CONVECTION ROLLING SEWD FROM SOUTH-
CENTRAL COLORADO. DECIDED TO EXPAND THE FLASH FLOOD WATCH
EASTWARD TO INCLUDE AREAS THAT WERE ESPECIALLY HARD HIT ON
WEDNESDAY. DID NOT INCLUDE THE NC/NE ZONES WHERE STORM MOTIONS
WILL BE PRETTY DECENT AS COMPARED TO RECENT DAYS. POTENTIAL FOR A
FEW STRONG IF NOT SEVERE STORMS HERE...ESPECIALLY ACROSS THE
NORTHEAST PLAINS AND NORTHERN PORTIONS OF THE EAST CENTRAL PLAINS
IF THE LATEST HRRR IS CORRECT. OTHERWISE...UPPER LEVEL COL REGION
OVER THE SOUTHWEST PART OF THE FORECAST AREA TODAY WHERE THE FLASH
FLOOD THREAT ARGUABLY IS THE HIGHEST. KJ
&&
.PREV DISCUSSION...1155 AM MDT THU JUL 25 2013...
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
50
.PREV DISCUSSION...603 AM MDT THU JUL 25 2013...
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
41
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1155 AM MDT THU JUL 25 2013
.AVIATION...
18Z TAF CYCLE
DYNAMIC DAY ON TAP AS A SHORTWAVE PASSING OVER THE SOUTHERN
ROCKIES COMBINES WITH DEEP MONSOONAL MOISTURE FOUND CURRENTLY OVER
THE MAJORITY OF THE FORECAST AREA. EXPECTING QUICKER MOVING STORMS
TODAY THUS MULTIPLE HITS ON TERMINAL SITES ARE POSSIBLE WITH
ABRUPT CHANGES IN THE WEATHER. THE MOST LIKELY TERMINALS TO BE
IMPACTED INCLUDE SAF/LVS/TCC AND ROW. ABQ AND GUP BASED ON VISIBLE
SATELLITE TRENDS ALSO SHOW THE POTENTIAL OF BEING AFFECT BY SH/TS.
VIS/CIG RESTRICTIONS WILL BE POSSIBLE ALTHOUGH SHORT IN DURATION
DUE TO THE FASTER FLOWS ACROSS THE NORTH AND EAST. WESTERN SITES
WILL SEE SLOWER MOVING CELLS. SLIGHT CHANCE OF REALLY STRONG WINDS
AND HAIL WITH SOME OF THE STRONGER STORMS. SOME OVERNIGHT STORMS
POSSIBLE WITH A BACK DOOR FRONTAL BOUNDARY ACROSS THE EAST
TONIGHT.
50
&&
.PREV DISCUSSION...603 AM MDT THU JUL 25 2013...
.AVIATION...
12Z TAF CYCLE
WITH THE 500 MB HIGH PRESSURE SYSTEM RECENTERING OVER AZ AND NW
FLOW ALOFT CROSSING NE NM...STORMS WILL SHIFT DIRECTION TODAY
COMPARED TO YESTERDAY. MOST OF THE ACTIVITY WILL MOVE TO THE S OR
SW AT A GOOD 15 TO 25 MPH...EXCEPT FOR SLOWER SPEEDS EXPECTED S OF
I-40. TS/SHRA COVERAGE TODAY SHOULD BE SCT-NMRS BY LATE AFTN...EXCEPT
FOR MORE ISOLD ACTIVITY ACROSS THE FOUR CORNERS. STORMS WILL AGAIN
BE CAPABLE OF PRODUCING HEAVY RAIN WITH MT OBSC...BRIEF PERIODS OF
IFR CONDITIONS AND WET MICROBURSTS WITH ERRATIC WIND GUSTS
APPROACHING 45 KT. THE EXCEPTION WILL BE THE NE CORNER...WHERE A
FEW TS COULD TURN SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A
BACK DOOR COLD FRONT WILL PRODUCE A WIND SHIFT OUT OF THE N ACROSS
THE PLAINS TONIGHT...AND THIS FRONT WILL LIKELY BE ACCOMPANIED BY
THUNDERSTORMS.
44
.PREV DISCUSSION...310 AM MDT THU JUL 25 2013...
SIGNIFICANTLY MORE CHALLENGING FORECAST CYCLE THIS MORNING WITH LOTS
OF CONFLICTING MODEL GUIDANCE. LATEST RADAR AND SATELLITE TRENDS SHOW
WIDESPREAD RAIN/STORMS STILL IMPACTING SOUTHERN NM AND MUCH OF THE
EASTERN PLAINS. THE 05Z HRRR AND RUC HAVE A GOOD HANDLE OF THE CURRENT
PRECIP DISTRIBUTION OVER THE AREA WHILE THE 00Z NAM/GFS/ECMWF CONFLICT
ON SEVERAL ASPECTS. WILL LEAN FIRST 12-18 HOURS OF THE FORECAST ON THE
TRENDS OF THE HRRR FORECAST AND PLACE GREATEST POPS ACROSS THE SOUTH
AND EAST. WILL CONTINUE FLASH FLOOD WATCH FOR CATRON...SOCORRO...AND
LINCOLN COUNTIES AS SUCH WITH ANTECEDENT CONDITIONS RIPE FOR INCREASED
FLOOD POTENTIAL. THE SPC SSEO GUIDANCE AND 00Z NAM/GFS/ECMWF ARE DRIER
IN THIS AREA WITH GREATEST FOCUS OVER THE NORTH AND EAST. THE UPPER
WAVE THAT THESE GUIDANCE MEMBERS SHOW IS VERY DIFFICULT TO POINT OUT
ON THE LATEST SATELLITE IMAGERY. WITH SUCH BIG DIFFERENCES THIS IS
A LOW CONFIDENCE FORECAST TODAY SO UPDATES ARE LIKELY FROM DAY CREW.
A BACK DOOR FRONTAL BOUNDARY IS EXPECTED TO SLIDE DOWN THE EASTERN
PLAINS EITHER LATE TONIGHT OR FRIDAY...WITH MORE STABLE AIR IN ITS
WAKE FOR THE EAST. THIS FRONT WILL HELP SERVE AS FOCUS FOR CONVECTION
ALONG THE CENTRAL HIGH TERRAIN AND CONT DVD HOWEVER DRIER AIR MAY BE
SHIFTING INTO THE AREA FROM THE WEST. LEFT POPS JUST ABOVE CLIMO WITH
HIGHEST VALUES OVER HIGH TERRAIN. TEMPS WILL REMAIN SLIGHTLY BELOW
NORMAL IN THIS PATTERN SIMPLY DUE TO ALL THE MOISTURE AND CLOUD COVER
OVER THE AREA.
BY SATURDAY AND SUNDAY THE MODEL GUIDANCE IS NOW ALL OVER THE PLACE
WITH RESPECT TO POSITION/STRENGTH OF H5 HIGH CENTER. THE NAM/ECMWF ARE
QUITE WET FOR CENTRAL NM WITH A PERTURBATION SWINGING OVER THE AREA...
WHILE THE GFS IS QUITE A BIT DRIER NOW. MODEL AGREEMENT DETERIORATES
EVEN FURTHER NOW INTO NEXT WEEK. THE TREND IS MUCH DRIER THAN PREVIOUS
GUIDANCE...WHICH IS SUCH A BIG CHANGE SO WILL KEEP THINGS RELATIVELY
UNCHANGED AND AWAIT FOR MORE CONSISTENCY BEFORE TAPERING OFF POP VALUES.
GUYER
.FIRE WEATHER...
THOUGH RECENTLY WEAKENED...THE 500 MB HIGH PRESSURE SYSTEM IS
PROGGED TO GRADUALLY REORGANIZE OVER AZ TODAY AS AN UPPER LEVEL
TROUGH CLIPS NE NM IN NW FLOW ALOFT. TRAPPED UNDER THE RIDGE
ALOFT...THE MONSOON MOISTURE PLUME SHOULD REMAIN ORIENTED FROM SW TO
NE PARTS OF THE FORECAST AREA TODAY. WETTING PRECIP CHANCES SHOULD
FAVOR THE SANGRES EASTWARD TODAY DUE TO THE UPPER LEVEL TROUGH. THE
SOUTHWEST TO THE SOUTH CENTRAL MOUNTAINS SHOULD ALSO BE FAVORED
AGAIN DUE TO AN ABUNDANCE OF MOISTURE ALREADY IN PLACE. STORM
MOTIONS TODAY WILL BE TOWARD THE SOUTHEAST OR TOWARD THE SOUTH DUE
TO THE UPPER HIGH CIRCULATION CENTERED ON AZ.
A BACK DOOR COLD FRONT WILL DIVE SOUTHWARD THROUGH THE EASTERN
PLAINS TONIGHT AND IT WILL PROBABLY BE ACCOMPANIED BY ADDITIONAL
STORMS. IT IS EXPECTED TO PUSH INTO THE CENTRAL VALLEY WITH A
MODESTLY GUSTY EAST CANYON WIND FRIDAY MORNING. THEN IT SHOULD HELP
TO INVIGORATE CONVECTION ACROSS THE NORTHERN MOUNTAINS...CONTINENTAL
DIVIDE AND WESTERN MOUNTAINS ON FRIDAY. MEANWHILE...THE EASTERN
PLAINS SHOULD BE MORE STABLE ON FRIDAY DUE TO COLDER AIR IN THE WAKE
OF THE FRONT. THAT SAID...A SOME ELEVATED CELLS MAY DRIFT OFF THE
SANGRES AND ONTO THE NORTHEAST HIGHLANDS LATE FRIDAY AFTERNOON.
FOR THE COMING WEEKEND...MODELS SHIFT THE UPPER HIGH OVER S NM AND
NORTHERN MEXICO AS A SERIES OF WEAK PERTURBATIONS CROSS THE CENTRAL
ROCKIES AND NORTHERN NM IN WESTERLY FLOW ALOFT. THUNDERSTORMS SHOULD
REMAIN ACTIVE AS THE SHORTWAVES INTERACT WITH RECYCLING MOISTURE.
THE BEST CHANCE FOR THUNDERSTORMS WITH WETTING RAIN SHOULD FAVOR THE
MOUNTAINS AND ALSO THE NORTHERN VALLEYS AND NORTHEAST PLAINS AS
STORMS SHIFT EASTWARD WITH THE MEAN FLOW. TEMPERATURES THROUGH THE
END OF THE WEEK AND THE WEEKEND WILL GENERALLY VARY FROM NEAR NORMAL
TO AS MUCH AS 6 DEGREES BELOW NORMAL.
THE WESTERLIES OVER NORTHERN NM WILL GRADUALLY INTRODUCE DRIER AIR
WITH A NOTABLE DOWNTICK IN CONVECTIVE COVERAGE MONDAY AND TUESDAY.
TEMPERATURES WILL ALSO REBOUND CLOSER TO NORMAL DURING THIS
PERIOD...EXCEPT A FEW DEGREES ABOVE NORMAL ACROSS THE SE. THE GFS
AND ECMWF AGREE THAT THE UPPER HIGH CENTER MAY REPOSITION EAST OF
THE FORECAST AREA WEDNESDAY ALLOWING A LITTLE BETTER MOISTURE INTO
NEW MEXICO.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
408 PM EDT THU JUL 25 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ACROSS THE NORTH COUNTRY THROUGH
FRIDAY...AS LOW PRESSURE MOVES TOWARD CAPE COD. THIS WILL INCREASE
CLOUDS ACROSS PARTS OF OUR REGION...WITH A CHANCE OF SHOWERS
POSSIBLE FOR EASTERN VERMONT THROUGH FRIDAY. A STRONGER SYSTEM AND
ASSOCIATED FRONT WILL PRODUCE A PERIOD OF SHOWERS WITH EMBEDDED
STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL
THROUGH FRIDAY...BEFORE RETURNING CLOSE TO NORMAL OVER THE
WEEKEND...WITH SOME INCREASE IN HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
AS OF 410 PM EDT THURSDAY...WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS
THE EASTERN CONUS WHILE POTENT S/W ENERGY AND DEEP TROPICAL
MOISTURE IS LOCATED OFF THE MID ATLANTIC COAST. THIS ENERGY WL
HELP IN THE DEVELOPMENT OF SFC LOW PRES TONIGHT...WHICH WL TRACK
TWD CAPE COD BY FRIDAY. LATEST 12Z GUIDANCE SHOWS A SLIGHT
WESTWARD TRACK AND PLACEMENT OF QPF...BUT STILL MAINLY EAST OF OUR
CWA. LATEST HRRR REFLECTIVITY AND QPF PROGS SHOW LIGHT RAIN
SHOWERS IMPACTING ORANGE AND WINDSOR COUNTIES AFT 04Z TONIGHT. WL
MENTION CHC POPS ACRS THIS REGION. NAM/GFS SHOW A CLOSED 7H
CIRCULATION OVER SNE...WITH SFC LOW PRES OVER CAPE COD AT 18Z
FRIDAY...AS BEST 850 TO 500MB RH AND UVVS FIELDS ARE JUST EAST OF
OUR CWA. BOTH MODELS ALONG WITH THE ECMWF SHOW A SHARP WEST TO
EAST GRADIENT IN RH AND QPF FIELDS...THRU FRIDAY. WL CONT TO
MENTION SCHC TO LOW CHC POPS ACRS EASTERN VT. THINKING MOST PRECIP
WL EVAPORATE BEFORE REACHING THE GROUND...PER DEPTH OF DRY LAYER
ON SOUNDINGS. TEMPS WL BE TRICKY TONIGHT...BASED ON
CLOUDS...THINKING U30S SLK TO M50S VSF.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 410 PM EDT THURSDAY...PROGRESSIVE FLW ALOFT WL QUICKLY LIFT S/W
ENERGY AND DEEPER MOISTURE NORTHEAST ALONG THE EASTERN SEABOARD
ON FRIDAY. ONCE AGAIN ANTICIPATE A SHARP WEST TO EAST GRADIENT IN
RH FIELDS...WITH MAYBE A BRIEF SHOWER ACRS EXTREME EASTERN VT. WL
CONT TO MENTION SCHC POPS. PROGGED 85H TEMPS WARM ANOTHER 2 TO 3C
FROM THURS...TO SUPPORT NEAR NORMAL HIGHS IN THE 70S MTNS TO L/M
80S VALLEYS. WARMEST TEMPS WL BE ACRS THE SLV...WHERE SKIES WL BE
SUNNY.
FRIDAY NIGHT THRU SATURDAY NIGHT...DEEP CLOSED AND NEARLY VERTICAL
STACKED SYSTEM ACRS THE CENTRAL GREAT LAKES WL SLOWLY APPROACH THE
NE CONUS. THE MID/UPPER LVL FLW AHEAD OF THIS SYSTEM WL BECM
SOUTHERLY WITH SEVERAL EMBEDDED S/W`S...ESPECIALLY SAT AFTN/EVENING.
IN ADDITION...LATEST 12Z GFS SHOWS SEVERAL RIBBONS OF ENHANCED 850
TO 500MB RH ADVECTING FROM SOUTH TO NORTH ACRS OUR FA...IN THE
SOUTHERLY FLW ALOFT. HOWEVER...BEST LLVL SFC CONVERGENCE ASSOCIATED
WITH FRNT AND LOW PRES...ALONG WITH STRONGEST JET WINDS WL STAY WEST
OF OUR CWA THRU 12Z SUNDAY. INSTABILITY LOOKS LIMITED ON SAT ACRS
OUR CWA...AS NAM/GFS SHOW BEST PARAMETERS SOUTH OF OUR
FA...ASSOCIATED WITH HIGHER BL DWPTS. WL MENTION CHC POPS AFT 18Z
SATURDAY...ASSOCIATED WITH LOW/MID LVL WAA AND MOISTURE ADVECTION
ACRS OUR FA. QPF WL BE LIGHT WITH MAINLY SPRINKLES/VIRGA OCCURRING
INITIALLY. PROGGED 85H TEMPS BTWN 13 AND 15C...SUPPORT HIGHS BACK
INTO THE U70S MTNS TO M80S WARMER VALLEYS. IN ADDITION...HUMIDITY
LVLS WL CONT TO INCREASE...ESPECIALLY BY SAT NIGHT...ASSOCIATED WITH
SOUTHERLY FLW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 410 PM EDT THURSDAY...UPPER TROUGH OVER THE EASTERN GREAT
LAKES WILL BE SLOW TO MOVE EAST THROUGH THE FIRST HALF OF THE
EXTENDED PERIOD...SUNDAY THROUGH TUESDAY. AS A RESULT...DYNAMIC
SUPPORT WILL PLAY A FACTOR IN INCREASING PRECIPITATION CHANCES ON
SUNDAY WITH LIKELY TO CATEGORICAL PRECIPITATION CHANCES EXPECTED.
AFTER SUNDAY...THE AREA GETS IN THE DRY SLOT BEHIND THE COLD
FRONT...BUT STEEPENING LAPSE RATES DUE TO COLD AIR ADVECTION ALOFT
SUGGESTS THE POTENTIAL FOR DIURNALLY DRIVEN SHOWERS ON MONDAY AND
ESPECIALLY ON TUESDAY. WILL THEREFORE GO AHEAD AND ADD A CHANCE OF
SHOWERS TO MONDAY AND TUESDAY. WITH CLOUDS AND SHOWERS LINGERING
AROUND...LOOKING AT TEMPERATURES ABOUT 2 TO 4 DEGREES BELOW
NORMAL. WESTERLY FLOW DEVELOPS WEDNESDAY AND THURSDAY...SO DRIER
WEATHER IS EXPECTED ALONG WITH TEMPERATURES RIGHT AROUND SEASONAL
NORMALS.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...VFR EXPECTED THROUGH MUCH OF THE PERIOD. THE
ONLY EXCEPTIONS TO THIS WILL BE AT KMPV WHERE MVFR VISIBILITIES
ARE POSSIBLE BETWEEN 08Z AND 12Z AND AT KSLK WHERE VLIFR ARE
EXPECTED DUE TO LOW CLOUDS AND FOG DURING THIS SAME TIME PERIOD.
EXPECTING ONLY HIGH CLOUDS TO MOVE ACROSS THE AREA FROM THE SOUTH
WITH ANY RAIN REMAINING EAST OF THE AREA. WINDS WILL HAVE A
NORTHERLY COMPONENT TO THEM THROUGH MUCH OF THE PERIOD...BUT
SPEEDS WILL GENERALLY BE 10 KNOTS OR LESS.
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
18Z FRIDAY THROUGH 12Z SUNDAY...PRIMARILY VFR UNDER A RIDGE OF HIGH
PRESSURE.
12Z SUNDAY THROUGH TUESDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR LIKELY
IN SHOWERS AND POSSIBLE TSRA AS A COLD FRONT TRACKS THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
205 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS AFTERNOON...
WHILE WEAK HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH. THIS
HIGH PRESSURE WILL HOLD OVER THE AREA THROUGH FRIDAY NIGHT BEFORE
SHIFTING OFFSHORE ON SATURDAY. ANOTHER COLD FRONT WILL APPROACH FROM
THE NORTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM THURSDAY...
LATEST SURFACE ANALYSIS SHOWS A FEW NOTABLE BOUNDARIES AND FEATURES
ACROSS THE REGION... INCLUDING THE LEADING TROUGH/WIND SHIFT WHICH
HAS PUSHED WELL SOUTH INTO SRN GA... THE SURFACE LOW JUST OFF ILM
AND ITS TRAILING TROUGH ACROSS SRN SC WRAPPING BACK UP INTO SW NC...
AND THE PRIMARY FRONT STRETCHING NE-SW OVER NC... WHICH SEPARATES
DEWPOINTS IN THE UPPER 60S/LOWER 70S TO ITS SOUTH AND VALUES IN THE
UPPER 50S/LOWER 60S TO ITS NORTH. THIS LAST BOUNDARY HAS MOVED
LITTLE IN RECENT HOURS BUT AS THE OFFSHORE LOW CONTINUES TO DEEPEN
AND DRIFT TO THE NNE... THE ENHANCED NORTHERLY/NNERLY FLOW INTO NC
SHOULD STEADILY DRAW THE DRIER AIR TO THE NORTH FURTHER SOUTHWARD
INTO CENTRAL NC DURING THE DAY... PUSHING THE EFFECTIVE FRONTAL ZONE
SOUTHWARD. SATELLITE IMAGERY SHOWS THE MID LEVEL CLOUDINESS
ALONG/AHEAD OF THE 500 MB TROUGH AXIS OVER THE COASTAL PLAIN
SHIFTING EASTWARD... HOWEVER ABUNDANT LEFTOVER LOW LEVEL MOISTURE
AND INFLUX OF MARINE AIR IS CONTRIBUTING TO WIDESPREAD STRATOCU
DEVELOPMENT OVER THE AREA... MOVING TOWARD THE SW (A CONTRAST TO THE
EASTWARD-MOVING MID CLOUDS). THE RAP MODEL SHOWS THIS STRATOCU
SLOWLY LIFTING BUT PERSISTING WELL INTO THE AFTERNOON... AND RECENT
PILOT REPORTS SHOW THESE CLOUDS AROUND 1000-1500 FT DEEP... SO IT
WILL TAKE AWHILE FOR THESE TO BREAK UP AND MIX OUT. EXPECT MAINLY
MOSTLY CLOUDY SKIES IN THE EAST/SOUTH WITH ANY CLEAR AREAS IN THE NW
FILLING IN QUICKLY TO AT LEAST PARTLY CLOUDY. WE SHOULD SEE SOME
IMPROVEMENT LATE IN THE DAY FROM NORTH TO SOUTH AS SOME DRIER AIR TO
THE NORTH (NOTED ON 12Z IAD SOUNDING AT 925 MB) SLOWLY FILTERS IN.
WITH QUITE A BIT OF CINH AND LITTLE CAPE ANTICIPATED AS THE STRATOCU
REDUCES INSOLATION... THUNDER CHANCES APPEAR SMALL... ALTHOUGH
PATCHY SHOWERS REMAIN POSSIBLE ACROSS THE EAST AND FAR SOUTH WHERE
SURFACE DEWPOINTS HAVE YET TO DROP APPRECIABLY. WILL NUDGE POPS
DOWNWARD JUST A BIT OVERALL. TEMPS ARE RUNNING SEVERAL DEGREES BELOW
YESTERDAY`S NUMBERS... AND THIS PACE ALONG WITH NEAR TERM MODEL
GUIDANCE INDICATES HIGHS OF 80-86... A DOWNWARD BUMP IN THE
NORTHEAST WHERE CLOUD COVER WILL BE GREATEST AND WHERE THE BETTER
CHANCE OF SHOWERS WILL RESIDE. -GIH
TONIGHT...ADVECTION OF DRIER MORE STABLE AIR SHOULD LIMIT/DISSIPATE
ANY LEFTOVER AFTERNOON CONVECTION BY EARLY EVENING. SLIGHTLY DRIER
AIR WILL ALLOW TEMPS TO FALL INTO THE MID 60S ACROSS THE NORTH
OVERNIGHT AND UPPER 60S TO NEAR 70 IN THE SOUTH. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRIDAY...WEAK HIGH PRESSURE WILL NOSE SWD INTO THE REGION.
SUBSIDENCE BEHIND THE EXITING S/W SHOULD INITIALLY LIMIT CLOUD
PRODUCTION THOUGH AS AIR MASS HEATS UP...EXPECT SCATTERED CU TO
DEVELOP BY LATE MORNING-EARLY AFTERNOON. CONTINUED LOW LEVEL NE FLOW
WILL GIVE MANY PLACES A WELCOMED BREAK FROM 90+ DEGREES HEAT.
AFTERNOON TEMPS IN THE MID-UPPER 80S.
ANOTHER MID LEVEL TROUGH WILL APPROACH FROM THE WEST FRIDAY NIGHT.
UPPER LEVEL MOISTURE ADVECTION AHEAD OF THIS SYSTEM MAY RESULT IN A
DECK OF HIGH CLOUDS ENCROACHING ON OUR WESTERN COUNTIES OVERNIGHT.
THIS VEIL OF CLOUDS WILL HOLD TEMPS UP A BIT...RESULTING IN THE
COOLER MIN TEMPS OVER THE COASTAL PLAIN AND NE PIEDMONT. MIN TEMPS
MID-UPPER 60S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 205 PM THURSDAY...
A SHORT WAVE TROUGH CURRENTLY OVER THE CENTRAL PLAINS IS PROGGED TO
MOVE SE AND BOTTOM OUT IN THE BASE OF THE LONG WAVE TROUGH OVER THE
SOUTHERN APPALACHIANS EARLY SATURDAY...AND THEN SHEAR OUT ACROSS THE
MID ATLANTIC AND CAROLINAS BY LATE IN THE DAY. THE ASSOC SFC FRONT
WILL BE DELAYED BEHIND THIS FIRST SHORT WAVE...REACHING THE
CAROLINAS BY EARLY SUNDAY AS THE PARENT MID/UPR TROUGH GRADUALLY
DRIFTS ESE ACROSS THE GREAT LAKES. BOTH GFS AND ECMWF STILL SHOW THE
BEST MOISTURE INCREASE ACROSS THE WESTERN HALF OF THE STATE ON
SATURDAY...THUS FOR NOW WILL CONTINUE THE CURRENT POP ARRANGEMENT
SHOWING BEST CHANCE FOR SHOWER/TSTMS ACROSS THE WESTERN HALF OF OUR
CWA ON SATURDAY...WITH LITTLE IF ANY ACTIVITY EAST OF US1. AS THE
FRONT AND MOISTURE SHIFTS EAST SATURDAY NIGHT AND SUNDAY...WILL
EXPAND CHANCE POPS ACROSS THE ENTIRE CWA ON SUNDAY. IN TERMS OF
STORM INTENSITY...GIVE MODEST INSTABILITY AND WEAK DEEP LAYER
SHEAR...TSTMS ON SATURDAY SHOULD BE LIMITED IN INTENSITY. HOWEVER ON
SUNDAY...NOTED IN GUIDANCE A BRIEF INCREASE IN SHEAR DURING THE DAY
...SO WOULDN`T RULE OUT AN ISOLATED STRONG TSTM DURING THE DAY
SUNDAY. FINALLY...NOTED THAT PRECIP AMOUNTS IN BOTH MODELS AREN`T
PARTICULARLY HEAVY...GENERALLY LESS THAN 1/2 INCH FOR MOST
LOCATIONS...CERTAINLY NOT A WASHOUT FOR THE WEEKEND.
FOR THE REST OF THE LONG TERM...MONDAY THROUGH THURSDAY...LOOK FOR
REDUCED RAIN CHANCES ON MONDAY INTO TUESDAY AS DRYING TAKES PLACE
BEHIND THE AFOREMENTIONED FRONT AFTER IT MOVES TO OUR EAST EARLY
MONDAY. THEN THE NEXT MID LEVEL TROUGH IS PROGGED TO SET UP ACROSS
OUR AREA DURING THE MIDDLE OF THE WEEK...RESULTING IN AT LEAST
CLIMO-POPS FOR MAINLY DIURNAL SHOWERS AND TSTMS DURING THIS TIME.
REGARDING TEMPS DURING THE LONG TERM... THICKNESSES ARE PROGGED BY
THE GFS AND ECWMF TO REMAIN STEADY AND NEAR CLIMO THROUGH THE LONG
TERM PERIOD... SO LOOK FOR NEAR-NORMAL TEMPS THROUGH THE PERIOD...
HIGHS GENERALLY CLOSE TO 90 AND LOWS IN THE UPPER 60S TO NEAR 70.
THE ONLY DEVIATION FROM THIS MAY BE MONDAY NIGHT INTO TUESDAY...AS
TEMPS MAY BE A FEW DEGREES LOWER IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM THURSDAY...
VERY SLOW IMPROVEMENT FROM MVFR TO VFR BY SUNSET. AS A COLD FRONT
HAS SETTLED JUST SOUTH OF THE AREA... INCOMING COOLER AIR FROM THE
NORTH AND LOW LEVEL MOISTURE HAVE LED TO QUICK CLOUD DEVELOPMENT
THIS MORNING WITH MVFR CIGS OVER ALL OF CENTRAL NC. THIS FAIRLY
THICK DECK OF CLOUDS WILL BE SLOW TO LIFT AS COOL STABLE LOW LEVEL
AIR CONTINUES TO ADVECT INTO CENTRAL NC FROM THE NNE... SO EXPECT
MVFR CONDITIONS TO HOLD UNTIL 22Z-00Z... WHEN CIGS ARE EXPECTED TO
CLIMB JUST ABOVE 3 KFT. A FEW SHOWERS MAY AFFECT RDU/RWI/FAY BUT ARE
UNLIKELY TO REACH ENOUGH COVERAGE TO BE A PREVAILING CONDITION. VFR
CONDITIONS ARE EXPECTED TO THEN DOMINATE FROM 00Z THROUGH THE END OF
THE TAF PERIOD WITH CIGS JUST ABOVE 3 KFT. WINDS FROM THE NORTHEAST
AT 8-12 KTS MAY PERIODICALLY GUST TO 14-18 KTS UNTIL 00Z THIS
EVENING... THEN WILL BECOME LIGHT/VARIABLE UNDER 6 KTS THROUGH 18Z
FRIDAY.
LOOKING BEYOND 18Z FRIDAY... VFR CONDITIONS WILL HOLD HEADING INTO
THE WEEKEND... ALTHOUGH IFR CIGS ARE POSSIBLE AT INT/GSO LATE FRIDAY
NIGHT INTO SATURDAY MORNING... AND SCATTERED SHOWERS/STORMS
GENERATING MVFR CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON THROUGH
SUNDAY EVENING... AHEAD OF AN APPROACHING FRONT. WITH WEAK HIGH
PRESSURE BUILDING IN BEHIND THE FRONT... DRY WEATHER AND VFR
CONDITIONS ARE EXPECTED LATE SUNDAY NIGHT THROUGH TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...NP
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
133 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL SETTLE JUST SOUTH OF THE AREA THIS AFTERNOON...
WHILE WEAK HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTH. THIS
HIGH PRESSURE WILL HOLD OVER THE AREA THROUGH FRIDAY NIGHT BEFORE
SHIFTING OFFSHORE ON SATURDAY. ANOTHER COLD FRONT WILL APPROACH FROM
THE NORTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM THURSDAY...
LATEST SURFACE ANALYSIS SHOWS A FEW NOTABLE BOUNDARIES AND FEATURES
ACROSS THE REGION... INCLUDING THE LEADING TROUGH/WIND SHIFT WHICH
HAS PUSHED WELL SOUTH INTO SRN GA... THE SURFACE LOW JUST OFF ILM
AND ITS TRAILING TROUGH ACROSS SRN SC WRAPPING BACK UP INTO SW NC...
AND THE PRIMARY FRONT STRETCHING NE-SW OVER NC... WHICH SEPARATES
DEWPOINTS IN THE UPPER 60S/LOWER 70S TO ITS SOUTH AND VALUES IN THE
UPPER 50S/LOWER 60S TO ITS NORTH. THIS LAST BOUNDARY HAS MOVED
LITTLE IN RECENT HOURS BUT AS THE OFFSHORE LOW CONTINUES TO DEEPEN
AND DRIFT TO THE NNE... THE ENHANCED NORTHERLY/NNERLY FLOW INTO NC
SHOULD STEADILY DRAW THE DRIER AIR TO THE NORTH FURTHER SOUTHWARD
INTO CENTRAL NC DURING THE DAY... PUSHING THE EFFECTIVE FRONTAL ZONE
SOUTHWARD. SATELLITE IMAGERY SHOWS THE MID LEVEL CLOUDINESS
ALONG/AHEAD OF THE 500 MB TROUGH AXIS OVER THE COASTAL PLAIN
SHIFTING EASTWARD... HOWEVER ABUNDANT LEFTOVER LOW LEVEL MOISTURE
AND INFLUX OF MARINE AIR IS CONTRIBUTING TO WIDESPREAD STRATOCU
DEVELOPMENT OVER THE AREA... MOVING TOWARD THE SW (A CONTRAST TO THE
EASTWARD-MOVING MID CLOUDS). THE RAP MODEL SHOWS THIS STRATOCU
SLOWLY LIFTING BUT PERSISTING WELL INTO THE AFTERNOON... AND RECENT
PILOT REPORTS SHOW THESE CLOUDS AROUND 1000-1500 FT DEEP... SO IT
WILL TAKE AWHILE FOR THESE TO BREAK UP AND MIX OUT. EXPECT MAINLY
MOSTLY CLOUDY SKIES IN THE EAST/SOUTH WITH ANY CLEAR AREAS IN THE NW
FILLING IN QUICKLY TO AT LEAST PARTLY CLOUDY. WE SHOULD SEE SOME
IMPROVEMENT LATE IN THE DAY FROM NORTH TO SOUTH AS SOME DRIER AIR TO
THE NORTH (NOTED ON 12Z IAD SOUNDING AT 925 MB) SLOWLY FILTERS IN.
WITH QUITE A BIT OF CINH AND LITTLE CAPE ANTICIPATED AS THE STRATOCU
REDUCES INSOLATION... THUNDER CHANCES APPEAR SMALL... ALTHOUGH
PATCHY SHOWERS REMAIN POSSIBLE ACROSS THE EAST AND FAR SOUTH WHERE
SURFACE DEWPOINTS HAVE YET TO DROP APPRECIABLY. WILL NUDGE POPS
DOWNWARD JUST A BIT OVERALL. TEMPS ARE RUNNING SEVERAL DEGREES BELOW
YESTERDAY`S NUMBERS... AND THIS PACE ALONG WITH NEAR TERM MODEL
GUIDANCE INDICATES HIGHS OF 80-86... A DOWNWARD BUMP IN THE
NORTHEAST WHERE CLOUD COVER WILL BE GREATEST AND WHERE THE BETTER
CHANCE OF SHOWERS WILL RESIDE. -GIH
TONIGHT...ADVECTION OF DRIER MORE STABLE AIR SHOULD LIMIT/DISSIPATE
ANY LEFTOVER AFTERNOON CONVECTION BY EARLY EVENING. SLIGHTLY DRIER
AIR WILL ALLOW TEMPS TO FALL INTO THE MID 60S ACROSS THE NORTH
OVERNIGHT AND UPPER 60S TO NEAR 70 IN THE SOUTH. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRIDAY...WEAK HIGH PRESSURE WILL NOSE SWD INTO THE REGION.
SUBSIDENCE BEHIND THE EXITING S/W SHOULD INITIALLY LIMIT CLOUD
PRODUCTION THOUGH AS AIR MASS HEATS UP...EXPECT SCATTERED CU TO
DEVELOP BY LATE MORNING-EARLY AFTERNOON. CONTINUED LOW LEVEL NE FLOW
WILL GIVE MANY PLACES A WELCOMED BREAK FROM 90+ DEGREES HEAT.
AFTERNOON TEMPS IN THE MID-UPPER 80S.
ANOTHER MID LEVEL TROUGH WILL APPROACH FROM THE WEST FRIDAY NIGHT.
UPPER LEVEL MOISTURE ADVECTION AHEAD OF THIS SYSTEM MAY RESULT IN A
DECK OF HIGH CLOUDS ENCROACHING ON OUR WESTERN COUNTIES OVERNIGHT.
THIS VEIL OF CLOUDS WILL HOLD TEMPS UP A BIT...RESULTING IN THE
COOLER MIN TEMPS OVER THE COASTAL PLAIN AND NE PIEDMONT. MIN TEMPS
MID-UPPER 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 320 AM THURSDAY...
SATURDAY AND SATURDAY NIGHT...A WEAKENING MID-LEVEL SHORTWAVE IS
FORECAST TO MOVE INTO CENTRAL NORTH CAROLINA SATURDAY...WITH THE
OVERALL BEST MOISTURE FORECAST OVER THE WESTERN PIEDMONT. GIVEN THE
WEAKENING MID-LEVEL WAVE MOVING INTO THE AREA...850MB LIFT IS WEAK
AS WELL...WITH LIMITED DIFFLUENCE ALOFT. MOISTURE FIELDS...NOTABLY K
INDICES WHICH ARE ONLY IN THE TEENS DURING THE DAY OVER THE COASTAL
PLAIN ON THE GFS...INDICATE A DEFINITE TREND OF HIGHER MOISTURE
TOWARD THE YADKIN RIVER AND LEAST TOWARD THE COASTAL PLAIN...THE
FORMER WHERE THE BEST OF THE WEAK LIFT LIES. BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS ARE MORE UNSTABLE TOWARD KGSO THAN TOWARD
KRDU AND ESPECIALLY TOWARD KRWI. MLCAPE IS SLENDER AND FORECAST TO
BE 1000J/KG OR LESS IN CENTRAL NORTH CAROLINA SATURDAY...SO
CURRENTLY STRONG STORMS ARE NOT EXPECTED...BUT GIVEN THE AVAILABLE
MOISTURE AND INSTABILITY EVEN WITH MODEST SUPPORT ALOFT...ANTICIPATE
SCATTERED SHOWERS AND ISOLATED-TO-SCATTERED THUNDERSTORMS OVER THE
WESTERN PIEDMONT. THE CURRENT FORECAST HAS A SLIGHT CHANCE OF A
SHOWER OR THUNDERSTORM IN MOST AREAS FROM U.S. 1 EAST AND WILL NOT
WAFFLE OUT A SLIGHT CHANCE CURRENTLY WITH STATISTICAL GUIDANCE IN
THE 20S THROUGHOUT CENTRAL NORTH CAROLINA AT A MINIMUM...BUT WILL
ONLY HAVE CHANCES AT THE THRESHOLD OF SLIGHT FOR MOST AREAS EAST OF
A LINE FROM ABOUT KMEB TO KHNZ. ANY SHOWERS AND THUNDERSTORMS SHOULD
TEND TO DIMINISH DIURNALLY...WITH THE GREATER POTENTIAL AGAIN FOR A
FEW SHOWERS CONTINUING INTO THE OVERNIGHT HOURS OVER THE WESTERN
PIEDMONT. THERE...ANTICIPATE MOSTLY CLOUDY CONDITIONS ON AVERAGE IN
THE HIGHER 850MB MOISTURE SATURDAY...AND HIGHER MID-LEVEL MOISTURE
IN PLACE SATURDAY NIGHT. HIGHS IN THE 80S OVER THE FAR WESTERN
PIEDMONT...AROUND 90 FOR MOST AREAS FROM U.S. 1 EAST. OVERNIGHT LOWS
SATURDAY NIGHT UPPER 60S TO AROUND 70.
SUNDAY THROUGH WEDNESDAY...CENTRAL NORTH CAROLINA SHOULD BE IN A
WEAK TROUGH OR FRONTAL ZONE SUNDAY INTO MONDAY...WITH THE
CONVERGENCE APPEARING TO WEAKEN ON THE GFS AND SHIFTING EAST FROM
SUNDAY INTO MONDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS SHOULD BE
GOOD SUNDAY...GRADUALLY DIMINISHING OVERNIGHT SUNDAY AND SHIFTING
EAST FOR MONDAY. BY TUESDAY...MUCH OF CENTRAL NORTH CAROLINA IS IN A
RELATIVE MINIMUM OF MEAN MOISTURE AND IT WOULD APPEAR...IN THIS PART
OF THE LONG TERM PERIOD...TUESDAY WOULD HAVE THE LEAST CHANCE FOR
SHOWERS AND THUNDERSTORMS. MOISTURE RETURNS BY WEDNESDAY WITH WEAK
LOW PRESSURE AND LOWERING HEIGHTS IN THE BASE OF A LONG-WAVE
TROUGH...RENEWING SOLID CHANCES FOR SHOWERS AND THUNDERSTORMS AT THE
END OF THE LONG-TERM PERIOD. HIGH TEMPERATURES SHOULD MOSTLY RANGE
FROM 85 TO 90 DEGREES...AVERAGING NEAR THE HIGHER END OF THAT RANGE
WITH A FEW VALUES SLIGHTLY ABOVE 90 POSSIBLE ON THE CURRENTLY
EXPECTED DRIER DAYS OF MONDAY AND TUESDAY. OVERNIGHT LOWS MAINLY
WITHIN A DEGREE OR THREE OF 70.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 130 PM THURSDAY...
VERY SLOW IMPROVEMENT FROM MVFR TO VFR BY SUNSET. AS A COLD FRONT
HAS SETTLED JUST SOUTH OF THE AREA... INCOMING COOLER AIR FROM THE
NORTH AND LOW LEVEL MOISTURE HAVE LED TO QUICK CLOUD DEVELOPMENT
THIS MORNING WITH MVFR CIGS OVER ALL OF CENTRAL NC. THIS FAIRLY
THICK DECK OF CLOUDS WILL BE SLOW TO LIFT AS COOL STABLE LOW LEVEL
AIR CONTINUES TO ADVECT INTO CENTRAL NC FROM THE NNE... SO EXPECT
MVFR CONDITIONS TO HOLD UNTIL 22Z-00Z... WHEN CIGS ARE EXPECTED TO
CLIMB JUST ABOVE 3 KFT. A FEW SHOWERS MAY AFFECT RDU/RWI/FAY BUT ARE
UNLIKELY TO REACH ENOUGH COVERAGE TO BE A PREVAILING CONDITION. VFR
CONDITIONS ARE EXPECTED TO THEN DOMINATE FROM 00Z THROUGH THE END OF
THE TAF PERIOD WITH CIGS JUST ABOVE 3 KFT. WINDS FROM THE NORTHEAST
AT 8-12 KTS MAY PERIODICALLY GUST TO 14-18 KTS UNTIL 00Z THIS
EVENING... THEN WILL BECOME LIGHT/VARIABLE UNDER 6 KTS THROUGH 18Z
FRIDAY.
LOOKING BEYOND 18Z FRIDAY... VFR CONDITIONS WILL HOLD HEADING INTO
THE WEEKEND... ALTHOUGH IFR CIGS ARE POSSIBLE AT INT/GSO LATE FRIDAY
NIGHT INTO SATURDAY MORNING... AND SCATTERED SHOWERS/STORMS
GENERATING MVFR CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON THROUGH
SUNDAY EVENING... AHEAD OF AN APPROACHING FRONT. WITH WEAK HIGH
PRESSURE BUILDING IN BEHIND THE FRONT... DRY WEATHER AND VFR
CONDITIONS ARE EXPECTED LATE SUNDAY NIGHT THROUGH TUESDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...DJF
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1252 PM CDT THU JUL 25 2013
.UPDATE...
UPDATED AVIATION DISCUSSION BELOW...
.PREVIOUS UPDATE DISCUSSION...
SHORT WAVE TROUGH WILL MOVE EAST THROUGH THE AFTERNOON TAKING THE
SCATTERED SHOWERS/STORMS ALONG WITH MOST OF THE CLOUD COVER WITH
IT. VISIBLE SATELLITE AND RADAR SHOW THIS EASTWARD MOVEMENT/CLEARING
LATE THIS MORNING. WILL ADJUST GRIDS TO REFLECT THIS TREND.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENTLY SEEING SHORTWAVE ENERGY SLIDING SOUTHEAST WITHIN
NORTHWEST FLOW ALOFT ACROSS THE NORTHERN PLAINS. SFC FRONTAL
BOUNDARY HANGING OUT ACROSS THE REGION AS WELL. MAIN COMPLEX OF
STORMS RESIDES ACROSS WESTERN SOUTH DAKOTA AND IS MOVING
SOUTHEAST...LOOKING TO BE INTO THE SOUTHWEST CWA LATER THIS
MORNING. ALSO SEEING ADDITIONAL SHOWER AND STORM DEVELOPMENT
ACROSS SOUTH CENTRAL NORTH DAKOTA AND APPROACHING THE CWA BORDER.
HAVE MADE SOME ADJUSTMENTS TO WX/POPS OVER THE NEXT SEVERAL HOURS
TO ACCOUNT FOR CURRENT RADAR ACTIVITY. LATEST HRRR RUN SEEMS TO
HAVE A GENERAL IDEA OF WHATS GOING ON. ITS CORRECTLY SHOWING THE
PRESENCE OF THE LARGER CONVECTIVE SYSTEM OVER WESTERN SOUTH DAKOTA
AND IS ALSO SHOWING THE SMALLER INDIVIDUAL CELLULAR DEVELOPMENT
OVER SOUTH CENTRAL NORTH DAKOTA. TIMING IS A COUPLE HOURS OFF BUT
IT SEEMS TO BE DOING GENERALLY OK. TRIED TO LOCK ONTO THE HRRR
PLACEMENT OF CONVECTIVE SYSTEM THROUGH THE MORNING HOURS TO
CONSTRUCT WX/POPS. WILL LIKELY NEED TO ADJUST POPS HIGHER IN
PLACES DEPENDING ON EXACTLY WHERE INDIVIDUAL CONVECTIVE CLUSTERS
GO. IT STILL APPEARS SEVERE STORM THREAT TODAY WILL BE CONFINED TO
SOUTHEAST SOUTH DAKOTA AS MLCAPE REMAINS RATHER LOW OVER THE CWA
TODAY...ONLY A COUPLE HUNDRED J/KG.
THINGS DRY OUT THIS EVENING AS COOLER AND DRIER AIR BEGINS
FILTERING INTO THE CWA FROM THE NORTH WITH BUILDING HIGH PRESSURE.
THE REST OF THE SHORT TERM WILL BE DOMINATED BY THIS
HIGH...BRINGING COOL TEMPS FOR THIS TIME OF YEAR ALONG WITH DRY
CONDITIONS. IN FACT...SATURDAY MORNING LOWS WILL BE A BIT ON THE
CHILLY SIDE...WITH LOWS BOTTOMING OUT IN THE 40S FOR MANY
LOCATIONS.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
UPPER LEVEL NORTHWEST FLOW WILL BE ONGOING WHEN THE PERIOD
STARTS...BUT QUICKLY COMES TO AN END ON SUNDAY AS RIDGING PUSHES
OVER THE PLAINS. THE RIDGING GETS DAMPENED DURING THE DAY
MONDAY...THEN A MORE ZONAL FLOW PATTERN SETS UP...WITH A SERIES
OF SHORTWAVES MOVING THROUGH THE FLOW THROUGH THE END OF THE
PERIOD.
AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE EASTERN PLAINS
SATURDAY NIGHT AND SUNDAY. AN ELONGATED LOW PRESSURE SYSTEM THEN
APPROACHES FROM THE WEST AND SLOWLY TRACKS ACROSS THE REGION. WITH
THE SERIES OF UPPER SHORTWAVES MOVING THROUGH...CANNOT REALLY RULE
OUT ANY TIME PERIOD FROM SUNDAY NIGHT ON WHEN IT WILL BE DRY...SO
WILL STICK CLOSE TO THE ALLBLEND AND KEEP CHC/SCHC POPS IN SUNDAY
NIGHT THROUGH WEDNESDAY.
TEMPERATURES WILL BE A BIT BELOW NORMAL TO START OFF WITH SURFACE
HIGH PRESSURE IN CONTROL. SHOULD SEE TEMPERATURES BACK UP AROUND
NORMAL DURING THE LATTER HALF OF THE PERIOD AS WAA REDEVELOPS.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
HIGH PRESSURE BUILDING INTO THE NORTHERN PLAINS WILL BRING VFR
CONDS TO ALL TERMINALS THROUGH THE VALID FCST PERIOD. A WEAK
DISTURBANCE SLIDING QUICKLY THROUGH MAY BRING SOME SCT-BKN LOW
VFR /3K-4K FT/ CIGS TO THE KABR AND KATY TERMINALS BETWEEN 10Z AND
15Z FRIDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...TMT
LONG TERM...PARKIN
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1119 AM MDT THU JUL 25 2013
.UPDATE...
ISSUED AT 846 AM MDT THU JUL 25 2013
LEFTOVER MCS EXITING CWA VIA SOUTH CENTRAL SD THIS MORNING.
SHORTWAVE ENERGY ASSOCIATED WITH MCS HEADING AWAY WITH SUBSIDENCE
BEHIND IT. LATEST RAP GUIDANCE SUGGESTS SOME INSTABILITY WILL
REDEVELOP BEHIND WAVE THIS AFTERNOON WITH MODEST MLCIN. SUBSIDENCE
WILL TEND TO SUPPRESS ORGANIZED ACTIVITY...BUT MOST CONVECTIVE
ALLOWING MODELS SUPPORT CURRENT FORECAST OF LOW POPS THIS
AFTERNOON/EARLY THIS EVENING. FORECAST UPDATED TO MATCH CURRENT
CONDITIONS/TIMING OF REDEVELOPMENT.
&&
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT
ISSUED AT 344 AM MDT THU JUL 25 2013
NORTHERN STREAM SHORTWAVE TROUGH AND ASSOCIATED
CONVECTIVELY MODIFIED IMPULSE CONTINUES TO PROPAGATE SE ACROSS THE
AREA...SUPPORTING A DECENT CONVECTIVE COMPLEX ACROSS WESTERN SD. MCS
WILL CONTINUE TO PUSH SE ACROSS PORTIONS OF WESTERN SD...WITH
POSSIBLE ADDITIONAL BACKSIDE CONVECTION AS THE IMPULSE MOVES ACROSS
THE REGION AND THE PRIMARY LL TROUGH ADVECTS THROUGH THE FA...WITH A
CONTINUED POS THETA-E UPGLIDE REGIME. LL MOISTURE WILL INCREASE
BEHIND THIS INITIAL BOUNDARY...POSSIBLY SUPPORTING ADDITIONAL DIURNAL
SHRA/TS ACROSS THE SW HALF OF THE FA THIS AFTERNOON.
HOWEVER...CHANCES FOR PRECIP ARE EXPECTED TO WANE NORTH TO SOUTH
THROUGH THE DAY...AS BL MOISTURE BEGINS TO DEPLETE AND MID LEVEL
SUBSIDENCE COMMENCES ON THE BACKSIDE OF THIS MORNING/S WAVE. HAVE
ADJUSTED POPS/WX.
TEMPS WILL REMAIN TRICKY TODAY WITH A NOTED SIG SPREAD IN GUIDANCE
NUMBERS. HAVE SHIED FROM THE EXCESSIVELY WARM MAV...AND TRENDED
TOWARD THE MORE REASONABLE MET/ECMWF MOS NUMBERS...ESP GIVEN GFS
THERMAL FIELD BIAS. A STRONGER SECONDARY TROUGH WILL ADVECT THROUGH
ND AND INTO THE UPPER MIDWEST LATER TODAY INTO THIS
EVENING...SUPPORTING AN APPRECIABLE COLD FRONT INTO THE REGION
TONIGHT. THIS FRONT WILL COME THROUGH DRY...MAINLY SUPPORTING A
PERIOD OF POSSIBLE GUSTY N/NE WINDS.
SIG H85 TEMP ANOMALY WITH THIS TROUGH WILL SUPPORT TEMPS SOME 10 TO
15 DEGREES BELOW NORMAL FRIDAY...OVER THE EASTERN HALF OF THE
FA...WITH WARMER TEMPS RELEGATED TO THE FAR WEST. GIVEN PROGGED
ANOMALIES AND THERMAL FIELDS...HAVE CONTINUED THE TREND TO CUT
TEMPS FRIDAY...ESP ACROSS THE EAST WHERE SOME PLACES MAY STRUGGLE
TO BREAK 70. WEAK IMPULSE IN NW FLOW MAY SUPPORT AN ISOLD SHRA/TS
OVER NE WY AND THE BH LATE FRIDAY AFTERNOON...INTO SCENTRAL FRIDAY
NIGHT. MODELS CONTINUE TO INDICATE THIS SIGNAL AND HAVE RETAINED LOW
CHANCES POPS. COOL CONDITIONS WILL CONTINUE OVERNIGHT FRIDAY WITH
LOWS APPROACHING RECORD NUMBERS IN THE UPPER 40S OVER PORTIONS OF
WESTERN SD.
&&
.LONG TERM...SATURDAY THROUGH WEDNESDAY
ISSUED AT 344 AM MDT THU JUL 25 2013
PERSISTENT UPPER LEVEL RIDGE OVER THE SOUTHWESTERN
CONUS AND A TROF TO THE EAST OF THE REGION WILL KEEP ACTIVE WEST TO
NORTHWEST FLOW OVER THE NORTHERN PLAINS THROUGH EARLY NEXT WEEK. A
SERIES OF UPPER LEVEL DISTURBANCES WILL PASS OVER THE REGION THROUGH
THE EXTENDED PERIOD...AND WILL BRING A DAILY CHANCE FOR RAIN SHOWERS
AND THUNDERSTORMS ACROSS MUCH OF THE AREA. TEMPERATURES WILL BE
SLIGHTLY BELOW AVERAGE ON SATURDAY...AND RISE TO NEAR AVERAGE
LEVELS FOR SUNDAY THROUGH EARLY NEXT WEEK.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON
ISSUED AT 1119 AM MDT THU JUL 25 2013
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT. HOWEVER...
LOCAL MVFR CIGS WILL LINGER AROUND THE BLACK HILLS AREA INTO THE
EARLY AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE THIS AFTERNOON AND EVENING ACROSS PORTIONS OF
NORTHEASTERN WY AND WESTERN SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...15
AVIATION...26
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
550 PM CDT THU JUL 25 2013
.UPDATE...
NORTHWARD MOVING OUTFLOW BOUNDARY FROM EARLIER CONVECTION LOOKS
LIKE IT WILL SPARK OFF A FEW STORMS IN THE METROPLEX THIS EVENING
WHERE AIRMASS IS UNCAPPED AND UNSTABLE. HAVE RECONFIGURED THE
SPATIAL ORIENTATION OF THE LOW POPS FOR THIS EVENING BASED ON
LATEST TRENDS. TR.92
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT THU JUL 25 2013/
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 20 40 30 10 5
WACO, TX 78 98 75 94 74 / 20 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 20 50 20 5 5
MCKINNEY, TX 76 89 69 91 70 / 20 50 30 10 5
DALLAS, TX 79 95 73 92 75 / 20 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 78 97 74 93 73 / 10 40 30 10 10
TEMPLE, TX 76 98 75 94 73 / 20 30 30 10 10
MINERAL WELLS, TX 76 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
350 PM CDT THU JUL 25 2013
.DISCUSSION...
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 10 40 30 10 5
WACO, TX 78 98 75 94 74 / 20 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 10 50 20 5 5
MCKINNEY, TX 76 89 69 91 70 / 10 50 30 10 5
DALLAS, TX 79 95 73 92 75 / 10 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 78 97 74 93 73 / 20 40 30 10 10
TEMPLE, TX 76 98 75 94 73 / 20 30 30 10 10
MINERAL WELLS, TX 76 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/82
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
120 PM CDT THU JUL 25 2013
.UPDATE...
SENT A QUICK UPDATE TO INCREASE POPS ACROSS THE PERMIAN BASIN
REGION FOR THE REST OF THE AFTERNOON. CU FIELD RAPIDLY DEVELOPING
OVER THE PERMIAN BASIN REGION OVER THE LAST HOUR...RAISING
CONCERNS FOR SHOWERS AND THUNDERSTORMS POPPING UP ACROSS THIS AREA
SHORTLY. SURFACE ANALYSIS SHOWS A WEAK CONVERGENT AREA NEAR THE
NORTHERN PERMIAN BASIN AND LATEST RUC INDICATES CONVECTION
DEVELOPING ALONG THIS BOUNDARY AROUND 19-20Z.
&&
.PREV DISCUSSION... /ISSUED 1218 PM CDT THU JUL 25 2013/
AVIATION...
18Z TAF ISSUANCE
CONVECTION HAS DIMINISHED OVER PORTIONS OF SOUTHEAST NEW MEXICO
THIS MORNING AND ALTHOUGH THERE IS A POSSIBILITY OF ADDITIONAL
DEVELOPMENT THIS AFTERNOON...CHANCES ARE TOO LOW ATTM TO INCLUDE
IN THE TAF. WILL AMEND IF LATER TRENDS SHOW ANY IMMINENT CHANGES.
OTHERWISE...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS AT
ALL TAF SITES. GENERALLY SOUTH TO SOUTHEASTERLY WINDS AROUND 10KT
ARE SET TO PREVAIL THROUGH TODAY. A COLD FRONT WILL MOVE THROUGH
THE REGION DURING THE DAY FRIDAY AND WENT AHEAD AND SHIFTED WINDS
AT CNM/HOB/PEQ TO THE NORTH. WILL NEED TO MENTION THIS WIND SHIFT
AT THE OTHER SITES IN THE NEXT TAF ISSUANCE.
PREV DISCUSSION... /ISSUED 416 AM CDT THU JUL 25 2013/
DISCUSSION...
SCATTERED SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS THE TX
PANHANDLE AND SOUTHERN PARTS OF NEW MEXICO INCLUDING THE GUADALUPE
MOUNTAINS EARLY THIS MORNING. COULD SEE MORE SCATTERED SHOWERS AND
STORMS THIS AFTERNOON MAINLY ALONG AND NORTH OF I-20 AS A MID LEVEL
THETA E AXIS MOVES ACROSS THE AREA. TEMPERATURES WILL BE ABLE TO
CLIMB WELL INTO THE 90S AND LOWER 100S OVER MOST OF THE REGION
BEFORE CLOUDS THICKEN LATE IN THE AFTERNOON. RICH MOISTURE REMAINS
IN PLACE WITH PWATS NEAR 1.5" SO LOCALLY HEAVY RAIN IS POSSIBLE WITH
ANY STORM ONCE AGAIN TODAY.
A S/W MOVING ACROSS THE SOUTHERN PLAINS FRIDAY WILL BRIEFLY NUDGE
THE UPPER RIDGE WEST AND ALLOW A WEAK COLD FRONT TO BRUSH THE
REGION. THE FRONT IS STILL EXPECTED TO ARRIVE FRIDAY AROUND LUNCH
ACROSS THE PERMIAN BASIN PUSHING SOUTH AND WEST FRIDAY NIGHT.
FORCING AND LARGE SCALE LIFT WILL REMAIN WELL NE OF THE REGION SO
NOT MUCH IN THE WAY OF PRECIP IS EXPECTED WITH THE FRONT. ONE
EXCEPTION IS ACROSS LOCATIONS WEST OF THE PECOS RIVER BOTH LATE
FRIDAY AND SATURDAY AFTERNOON WHERE UPSLOPE FLOW WILL BE ENHANCED
BEHIND THE FRONT. SLIGHT COOLING BEHIND THE FRONT IS EXPECTED
SATURDAY WITH HIGHS DROPPING ABOUT 5 DEGREES FROM FRIDAY.
THE UPPER RIDGE BUILDS BACK ACROSS THE AREA BY SUNDAY AND STICKS
AROUND THROUGH MOST OF NEXT WEEK. HIGHS WILL CLIMB BACK INTO THE
UPPER 90S AND 100S OVER MOST OF THE REGION WITH THE USUAL AFTERNOON
STORM CHANCES CONFINED TO THE HIGHER TERRAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 73 96 69 91 / 20 20 10 10
BIG SPRING TX 75 97 69 91 / 20 20 10 10
CARLSBAD NM 70 98 71 92 / 20 20 20 20
DRYDEN TX 76 104 75 98 / 10 20 20 20
FORT STOCKTON TX 74 99 71 93 / 10 20 30 20
GUADALUPE PASS TX 67 88 65 84 / 20 20 20 20
HOBBS NM 71 90 67 88 / 20 20 10 10
MARFA TX 62 89 65 84 / 10 30 30 20
MIDLAND INTL AIRPORT TX 76 100 71 93 / 10 20 10 10
ODESSA TX 74 99 70 93 / 10 20 20 10
WINK TX 75 101 74 96 / 10 20 20 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
27/44
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
151 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT THURSDAY...
AFTERNOON UPDATE WILL REFLECT A SMALLER REGION ACROSS THE
MOUNTAINS THIS AFTERNOON THAT WILL HAVE THE POTENTIAL FOR SOME
ISOLATED SHOWERS AND STORMS. THE REGION OF INTEREST NOW IS
BOUNDED BY THE AREA THAT INCLUDES MARION VA TO BLACKSBURG VA TO
STUART VA TO YADKINVILLE NC TO BOONE NC. WITH A CONVECTIVE
TEMPERATURE AROUND 80 DEGREES...IT WILL BE FAIRLY LATE IN THE
AFTERNOON UNTIL CONVECTION FIRES. SCATTERED COVERAGE IS EXPECTED
ALONG THE CREST OF THE BLUE RIDGE WHERE OROGRAPHIC IMPACTS MAY
ALLOW FOR GREATER COVERAGE. HAVE MADE SOME MINOR ADJUSTMENTS UP
AND DOWN FOR EXPECTED HIGH TEMPERATURES THIS AFTERNOON. MOST OF
THE ADJUSTMENTS UPWARD WERE IN THE WEST WHERE TEMPERATURES WERE
NEARING THE PREVIOUSLY EXPECTED HIGHS...AND THERE WERE PLENTY OF
BREAKS IN THE CLOUD COVER. MOST OF THE ADJUSTMENTS DOWNWARD WERE
IN THE EAST WHERE SOME AREAS WERE STILL ALMOST 10 DEGREES SHY OF
FORECAST HIGHS AND CLOUD COVER WAS MORE ABUNDANT.
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 140 PM EDT THURSDAY...
PRIMARILY LOW END VFR SCATTERED LAYERS AND BROKEN CEILINGS ACROSS
THE REGION THIS AFTERNOON. NO SHOWERS OR STORMS HAVE DEVELOPED
YET...BUT ISOLATED COVERAGE IS EXPECTED ALONG AND NEAR A KBCB-KTNB
LINE BETWEEN ROUGHLY 19Z/3PM AND 01Z/9PM. THE REGION REMAINS NORTH
OF A COLD FRONT WITH NE-E WINDS ACROSS THE PIEDMONT...WITH LIGHT
AND VARIABLE TO CALM OVER THE MOUNTAINS. THROUGH THE OVERNIGHT
HOURS...DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION IN THE
WAKE OF THE COLD FRONT AND THE APPROACH OF HIGH PRESSURE. THERE
WILL REMAIN THE POTENTIAL FOR STRATO-CU REDEVELOPMENT DURING THE
OVERNIGHT ALONG AND EAST OF THE BLUE RIDGE AS WHAT REMAINING LOW
LEVEL MOISTURE POOLS ON THE LEE SIDE OF THE APPALACHIANS. THESE
CLOUDS WILL RANGE FROM MVFR TO LOW END VFR. PATCHY MOUNTAIN AND
RIVER VALLEY FOG IS ALSO POSSIBLE LATE TONIGHT INTO EARLY FRIDAY
MORNING. ANY SUB-VFR CONDITIONS WILL IMPROVE TO VFR BY 14Z/10AM
FRIDAY.
HEADING INTO THE WEEKEND...HIGH PRESSURE MOVES EAST OF THE REGION
AND AN UPPER TROUGH/SURFACE COLD FRONT APPROACHES FROM THE WEST.
THE RESULT WILL BE A RETURN OF MOIST...SOUTHERLY FLOW INTO THE
REGION AND THE DEVELOPMENT OF SHOWERS AND STORMS. THESE WILL BE
MAINLY OVER THE MOUNTAINS LATE FRIDAY AFTERNOON AND EVENING.
SATURDAY AND THROUGH SATURDAY NIGHT...COVERAGE WILL INCREASE
ACROSS THE ENTIRE REGION AS THE FRONT MOVES THROUGH THE REGION.
SOME OF THESE STORMS MAY BE ON THE STRONG SIDE. AREAS OF SUB-VFR
CEILINGS AND VISIBILITIES WILL ACCOMPANY THE HEAVIER SHOWERS AND
STORMS.
ON SUNDAY...THE FRONT WILL BE EAST OF THE AREA...HOWEVER...A WAVE
MOVING NORTH ALONG THE FRONT WILL HELP PROLONG THE CONVECTION AND
LOCALIZED SUB-VFR CONDITIONS OVER MAINLY EASTERN PARTS OF THE
AREA.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVER THE AREA.
THIS WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT
NIGHTTIME AND EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE
THANKS TO PLENTY OF BOUNDARY LAYER MOISTURE IN PLACE AFTER THE
RAIN OVER THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1256 PM EDT THU JUL 25 2013
.SYNOPSIS...
A COLD FRONT WILL DRIFT SOUTHEAST OF THE AREA TODAY...AS ITS
ASSOCIATED UPPER TROUGH CROSSES THE REGION THIS AFTERNOON. HIGH
PRESSURE WILL SETTLE OVER THE AREA LATER TONIGHT INTO FRIDAY...AND
SHIFT EAST TO THE COAST BY SATURDAY. OUR NEXT COLD FRONT WILL MOVE
THROUGH THE AREA SATURDAY NIGHT THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EDT THURSDAY...
AFTERNOON UPDATE WILL REFLECT A SMALLER REGION ACROSS THE
MOUNTAINS THIS AFTERNOON THAT WILL HAVE THE POTENTIAL FOR SOME
ISOLATED SHOWERS AND STORMS. THE REGION OF INTEREST NOW IS
BOUNDED BY THE AREA THAT INCLUDES MARION VA TO BLACKSBURG VA TO
STUART VA TO YADKINVILLE NC TO BOONE NC. WITH A CONVECTIVE
TEMPERATURE AROUND 80 DEGREES...IT WILL BE FAIRLY LATE IN THE
AFTERNOON UNTIL CONVECTION FIRES. SCATTERED COVERAGE IS EXPECTED
ALONG THE CREST OF THE BLUE RIDGE WHERE OROGRAPHIC IMPACTS MAY
ALLOW FOR GREATER COVERAGE. HAVE MADE SOME MINOR ADJUSTMENTS UP
AND DOWN FOR EXPECTED HIGH TEMPERATURES THIS AFTERNOON. MOST OF
THE ADJUSTMENTS UPWARD WERE IN THE WEST WHERE TEMPERATURES WERE
NEARING THE PREVIOUSLY EXPECTED HIGHS...AND THERE WERE PLENTY OF
BREAKS IN THE CLOUD COVER. MOST OF THE ADJUSTMENTS DOWNWARD WERE
IN THE EAST WHERE SOME AREAS WERE STILL ALMOST 10 DEGREES SHY OF
FORECAST HIGHS AND CLOUD COVER WAS MORE ABUNDANT.
AS OF 950 AM EDT THURSDAY...
HAVE OFFERED ONLY A FEW CHANGES THIS MORNING AS COMPARED TO THE
EARLIER FORECAST. ONE ADJUSTMENT WAS DELAY BY AROUND TWO HOURS
THE PROBABILITY OF ISOLATED TO SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER THE MOUNTAINS. 12Z/7AM KFCX SOUNDING SHOWED A
DECENT STABLE LAYER THAT WILL NEED TO OVERCOME BEFORE ANY SHOWERS
BEGIN TO FIRE. BELIEVE THAT WILL MORE LIKELY START TO HAPPEN IN
THE EARLY AFTERNOON AS COMPARED TO THE LATE MORNING. HAVE ALSO
TWEAKED HOURLY TEMPERATURE...DEW POINT...WIND AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS INTO THE EARLY
AFTERNOON.
AS OF 320 AM EDT THURSDAY...
BUSY OVERNIGHT WITH LOTS OF TRAINING CONVECTION AND EMBEDDED
STRONGER CELLS ACROSS THE SOUTH THAT HAVE CONTINUED DESPITE
LACK OF ANY INSTABILITY. APPEARS SHRA DRIVEN BY SLOWING OF THE
DEWPOINT FRONT ALONG THE BLUE RIDGE PER SFC WAVE WELL TO THE
SOUTH AND AIDED ALOFT BY APPROACH OF ADDED 5H ENERGY THROUGH THE
TROUGH PER LATEST ANALYSIS. GUIDANCE TAKES THIS FEATURE ACROSS THE
REGION SHORTLY AFTER DAYBREAK WITH THE MID LEVEL TROF AXIS ALSO
SWINGING TO THE EAST THIS AFTERNOON. THIS COMBINED WITH THE
DEEPENING OF THE COASTAL WAVE PASSING TO THE EAST BY THIS EVENING
SHOULD FINALLY GIVE A LITTLE MORE SOUTHWARD PUSH OF DRIER AIR NOW
FILTERING IN FROM THE NORTH. HOWEVER THE SFC RIDGE REMAINS PRETTY
WEAK...AND OFF TO THE NORTH TODAY WHICH MAY ALLOW FOR ENOUGH
RESIDUAL MOISTURE TO INTERACT WITH SOME HEATING...AND EASTERLY
FLOW TO DEVELOP ADDED SHRA/TSRA MAINLY BLUE RIDGE WEST. MODELS
SHOW SOME LIGHT QPF OVER THE WEST AFTER EARLY SHRA FINALLY FADES
SO RAN WITH 20/30 POPS WESTERN THIRD AFTER CHANCE/LIKELYS PARTS OF
THE EAST/SOUTH EARLY ON. HOWEVER COULD EASILY SEE ONLY ISOLATED
COVERAGE PER LATEST HRRR GUIDANCE UNLESS MORE HEATING DEVELOPS
THIS AFTERNOON. CLOUDS WILL BE TRICKY WITH NE FLOW HELPING AID
LOW CLOUDS THIS MORNING BEFORE THE FLOW TURNS MORE NORTH WHICH
SHOULD HELP SCOUR THINGS OUT LATER IN THE DAY. THUS KEPT TEMPS
CLOSE TO PREVIOUS AND SIMILAR TO THE LATEST MAV MOS.
OFFSHORE WAVE HEADS NE OVERNIGHT ALLOWING THE SFC HIGH TO DROP IN
FROM THE NORTH. THIS SHOULD FINALLY START TO DIMINISH LEFTOVER
CLOUDS BUT STILL LEARY THIS TIME OF YEAR BEING ABLE TO TOTALLY DRY
THINGS OUT ESPCLY GIVEN LIGHT FLOW AND TRAJECTORIES TURNING MORE
SOUTH ALOFT LATE. THEREFORE KEPT IN MORE CLOUDS ESPCLY SW AND
EVEN A TOKEN ISOLATED -SHRA MENTION AFTER THIS EVENING ALONG THE
SRN BLUE RIDGE. OTRW MAINLY EVENING POPS FOR NOW AND MAINLY
MOUNTAINS WHERE LOW LEVEL MOISTURE WILL BE HARDER TO SCOUR OUT.
WONT GO AS COOL AS MOS OVERNIGHT...ALTHOUGH IF MORE CLEARING DOES
TAKE SHAPE...THEN COULD SEE SOME OF THE NW VALLEYS FALL INTO THE
LOWER 50S...WITH UPPER 50S OUT TO THE BLUE RIDGE...AND OVERALL LOW
60S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 350 AM EDT THURSDAY...
AN UPPER LEVEL THROUGH WILL PUSH A COASTAL LOW WELL NORTH OF THE
AREA FRIDAY. HEIGHTS WILL RISE OVER THE REGION BEHIND THIS
TROUGH...AS IT ALSO TRACKS TO THE NORTH. AT THE SURFACE...A WEAK
RIDGE OF HIGH PRESSURE SHOULD HAVE THE LOW LEVEL FLOW OUT OF THE
SOUTHEAST. THIS WILL BRING MOISTURE IN FROM THE ATLANTIC WITH A
CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS STARTING ALONG THE
BLUE RIDGE FRIDAY AFTERNOON. MOISTURE WILL INITIALLY BE LIMITED TO
KEEP SHOWERS TO THE SOUTHERN BLUE RIDGE THROUGH THE AFTERNOON...THEN
POSSIBLY SPREAD NORTHWARD IN THE EVENING TO THE ALLEGHANY HIGHLANDS.
A SIGNIFICANT SHORT WAVE IS EXPECTED TO TRACK ACROSS THE SOUTHERN
OHIO VALLEY EARLY SATURDAY MORNING. THIS WAVE MAY OR MAY NOT STEAL
MOISTURE AND ENERGY AWAY FROM THE AREA TO CUT OVERNIGHT POPS. THIS
WAVE MAY ENHANCE SOUTHEASTERLY LOW LEVEL FLOW...ESPECIALLY ACROSS
THE NORTH CAROLINA HIGH COUNTY...TO KEEP THE BEST POPS SOUTH THROUGH
THE OVERNIGHT. THIS SHORT WAVE IS EXPECTED TO STAY WEST OF THE AREA
SATURDAY...TRACKING THROUGH THE OHIO VALLEY. ENERGY FROM THIS SYSTEM
WILL STILL CLIP THE AREA AND MAY START A DOMINO OF STORMS MOVING
WEST TO EAST SATURDAY AFTERNOON AND EVENING. AS CONVECTION TRACKS
EAST...A COLD FRONT WILL GET PULLED ACROSS THE AREA SATURDAY NIGHT.
ANOTHER SHORT WAVE WILL RIDE ALONG THE FRONT AND PULL IT EAST OF THE
AREA ON SUNDAY.
EASTERLY FLOW WILL PRODUCE UNIFORM TEMPERATURES ACROSS THE
AREA FROM THE UPPER 70S TO LOWER 80S ON FRIDAY. AREAS SEEING RAIN
SATURDAY WILL LIKELY HAVE HIGHS AROUND 80F IN THE AFTERNOON.
AREAS...LIKE THE PIEDMONT...NOT SEEING RAIN UNTIL LATE IN THE
AFTERNOON MAY APPROACH 90F. COOLER TEMPERATURES ARE EXPECTED ONCE
THE FRONT MOVES EAST OF THE AREA SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
AS OF 400 PM EDT WEDNESDAY...
BROAD UPPER TROUGH CONTINUES ACROSS THE REGION THROUGH MUCH OF THE
LONG TERM AS WELL. BY MID NEXT WEEK...UPPER FLOW TENDS TO BECOME
MORE ZONAL. THE STRONG SUBTROPICAL RIDGE WILL REMAIN WELL WEST OF
THE REGION ACROSS THE WEST OR SOUTHERN PLAINS THROUGH THE PERIOD.
WOULD EXPECT SHRA/TSRA TO DECREASE SUN-MON AS THE UPPER TROUGH AXIS
AGAIN SHIFTS EAST OF THE CWA. HAVE CONFINED POPS...AND GENERALLY
SLIGHT AT BEST...TO THE FAR SE AND NW NC MOUNTAINS AS WE MOVE INTO
MON. THE NEXT UPSTREAM TROUGH...MORE OF A KINEMATIC/ZONAL SHORT WAVE
AT THAT TIME...WILL BEGIN TO SPREAD INCREASING SHRA/TSRA BACK INTO
THE REGION BY WED...SO HAVE ADVERTISED LIKELY POPS IN THAT TIME
FRAME. AS WITH THE SHORT TERM PERIODS...MAX/MIN TEMPS WILL REMAIN
NEAR OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD. AT THIS
TIME...THERE DOES NOT APPEAR TO BE ANY MAJOR WEATHER CONCERN THROUGH
WED...BUT AS USUAL...A FEW THUNDERSTORMS COULD BE SEVERE AND WITH
ANTECEDENT WET CONDITIONS...ISOLATED FLASH FLOODING COULD
OCCUR...MAINLY SUN OR AGAIN WED.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 650 AM EDT THURSDAY...
SHOWERS HAVE FINALLY FADED AND PUSHED TO THE EAST WITH ONLY
ISOLATED -SHRA REMAINING ACROSS THE PIEDMONT. HOWEVER LOWER MVFR
CIGS REMAIN IN PLACE IN SPOTS IN THE WAKE OF THE RAINFALL AIDED
BY LOW LEVEL NE FLOW WHILE LIFR AT KBLF PER DENSE FOG/STRATUS.
THE FLOW REMAINS OUT OF THE NORTHEAST TO EAST THIS MORNING BEFORE
WEAKENING AND TURNING MORE NORTHERLY THIS AFTERNOON. THUS SUB VFR
CIGS MAY LINGER EARLY...WITH VFR EXPECTED AFTER MIDDAY INTO EARLY
THIS AFTERNOON. ANY CONVECTION WILL BE CONFINED TO THE BLUE RIDGE
SOUTH AND WEST OF ROANOKE BUT TOO ISOLATED TO INCLUDE ANY MENTION
IN THE TAFS AT THIS POINT.
THE AXIS OF THE UPPER TROUGH PUSHES TO THE EAST THIS EVENING
ALLOWING BETTER DRYING TO ENSUE ESPCLY EARLY TONIGHT. EVEN THOUGH
DRIER INTRUSION OF AIR ARRIVES...THE FOG WILL BE AN ISSUE AT
BCB/LWB GIVEN WET SOILS AND LIGHT WIND. IN ADDITION...LATEST
BUFKIT SOUNDINGS SUGGEST THAT LIGHT EASTERLY FLOW UNDERNEATH WEAK
VEERING ALOFT MAY RESULT IN A RETURN TO LOWER CLOUDS REDEVELOPING
ALONG/WEST OF THE BLUE RIDGE BY FRIDAY MORNING. SINCE THIS COULD
BE OVERDONE WILL ONLY INCLUDE A PERIOD OF MVFR TO LOW END VFR CIGS
LATE AND HOLD OFF ON LOWERING TO IFR AT THIS POINT.
FRIDAY INTO SATURDAY...SURFACE HIGH PRESSURE BUILDS INTO AND THEN
EAST OF THE REGION WHILE THE UPPER TROUGH/LOW STALLS ALONG THE
COAST OF THE CAROLINAS. CONDITIONS WILL BE PRIMARILY VFR...HOWEVER
NIGHTTIME MOUNTAIN AND RIVER VALLEY FOG WILL BE POSSIBLE.
ON SATURDAY...ISOLATED TO SCATTERED SHOWERS AND STORMS WILL BE
AGAIN POSSIBLE ACROSS THE MOUNTAINS AS LOW LEVEL FLOW BECOMES
SOUTH ON THE WEST SIDE OF THE HIGH...AND ON THE EAST SIDE OF AN
APPROACHING TROUGH.
SATURDAY NIGHT INTO SUNDAY...SUB-VFR CONDITIONS WILL BECOME MORE
LIKELY AS A COLD FRONT APPROACHES AND THEN CROSSES THE REGION.
ON MONDAY HIGH PRESSURE RETURNS TO THE AREA. OTHER THAN SOME EARLY
MORNING MOUNTAIN AND RIVER VALLEY FOG...VFR CONDITIONS ARE
EXPECTED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...DS/JH
SHORT TERM...RCS
LONG TERM...RAB
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
526 PM CDT THU JUL 25 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 525 PM CDT THU JUL 25 2013
SHOWERS AND STORMS WILL BE ON THE INCREASE TONIGHT AS
A LOW PRESSURE DEVELOPS AND DEEPENS OVER NORTHERN WISCONSIN BY
FRIDAY MORNING. SHOWERS AND STORMS EXPECTED TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS LATE TONIGHT INTO FRIDAY MORNING ALONG WITH
SCATTERED AREAS OF IFR CIGS FRIDAY MORNING. A LITTLE DRIER AIR ON
NORTHWEST WINDS WORKING INTO PARTS OF CENTRAL AND EAST CENTRAL
WISCONSIN LATER FRIDAY MAY RAISE CIGS TO VFR LEVELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1236 PM CDT THU JUL 25 2013
AN AREA OF LOW PRESSURE WILL SLOWLY CURL FROM NORTHERN
MINNESOTA TO NORTHEAST WISCONSIN OVER THE TAF PERIOD. CLOUDS ALONG
WITH SHOWERS AND STORMS WILL BE BUILDING DURING THE
AFTERNOON...MAINLY WEST OF THE FOX VALLEY AND BAY OF GREEN BAY.
COVERAGE WILL LIKELY BE SCATTERED BUT DECENT ENOUGH TO IMPACT THE
CENTRAL WISCONSIN AND RHI TAF SITES. TIMING OF PRECIP THEREAFTER IS
RATHER DIFFICULT. BUT EARLY INDICATIONS ARE THAT THERE WILL BE A
LULL IN THE PRECIPITATION UNTIL LATE IN THE EVENING AND OVERNIGHT WHEN THE
LOW PRESSURE AND ATTENDANT COLD FRONT SLOWLY MOVE SOUTHEAST ACROSS
THE STATE. SEVERAL HOURS OF SHOWERS AND THUNDERSTORMS APPEARS LIKELY
AHEAD OF THE FRONT. BEHIND THE FRONT...WINDS WILL SHIFT TO THE
NORTHWEST AND USHER IN A MVFR OVERCAST WITH OCCASIONAL SHOWER
ACTIVITY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC