Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/09/13
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1032 AM MDT TUE MAY 7 2013
.UPDATE...
&&
.SHORT TERM...WEAKENING UPPER TROUGH CURRENTLY MOVING NORTH ACROSS
CWA. STILL SOME SHOWERS ONGOING ACROSS MOUNTAINS NORTH OF
INTERSTATE 70...PARTICULARLY IN LARIMER AND GRAND COUNTIES. FROM
SURFACE OBS AND WEB CAMS IT APPEARS SNOW LEVEL IS AROUND 10000
FEET. RECENT ACCUMULATIONS HAVE BEEN MINIMAL. SOME SHOWERS ALSO
OCCURRING ALONG NORTHERN FOOTHILLS AS WELL AS ACROSS PORTIONS OF
PLAINS...THESE SHOWERS WERE LIGHT. MODELS CONTINUE TO WEAKEN THIS
TROUGH AS IT MOVES INTO WYOMING AND NEBRASKA DURING THE AFTERNOON
WITH WEAK SUBSIDENCE ACROSS COLORADO. IN ADDITION LATEST RAP
SHOWING SOME DRYING. BUT AIRMASS IS EXPECTED TO BE SLIGHTLY
UNSTABLE AS NOTED BY LAPSE RATES AROUND 8 C/KM. RAP EVEN INDICATES
LOW LEVEL LAPSE RATES NEARING 10 C/KM. STILL SOME THREAT OF SHOWERS
THIS AFTERNOON WITH PERHAPS A FEW THUNDERSTORMS...MAINLY ACROSS
THE MOUNTAINS. WITH WEAKLY SHEARED ENVIRONMENT AND SURFACE BASED
CAPES AROUND 500 J/KG OR LESS...NOT EXPECTING STRONG/SEVERE STORMS.
CURRENT FORECASTS STILL SEEM ON TRACK...WITH MINOR CHANGES BASED
ON CURRENT CONDITIONS.
.AVIATION...CURRENT TAF TRENDS SEEM ON TRACK. A FEW LIGHT SHOWERS
MOVING SOUTHEAST ACROSS THE PLAINS...PRODUCING SOME BRIEF GUSTY
WINDS. OTHERWISE...NORTHERLY WINDS PREVAILING WITH SPEEDS AROUND
8 KTS. WINDS TO BECOME NORTHEAST DURING THE AFTERNOON...THEN
SOUTHEAST BY 01Z. SPEEDS SHOULD REMAIN UNDER 10 KTS. VFR
CONDITIONS TO PREVAIL THROUGH THE DAY WITH ANY SHOWERS TO BE
ISOLATED IN COVERAGE. NOT EXPECTING CEILINGS BELOW 10000 FEET AGL
AT THIS TIME.
&&
.HYDROLOGY...ONLY LIGHT SHOWERS EXPECTED THROUGH THE EVENING WITH
A SLIGHT CHANCE OF WEAK THUNDERSTORMS. RAINFALL AMOUNTS OF LESS
THAN A TENTH OF AN INCH EXPECTED. BETTER CHANCE FOR HEAVIER
RAINFALL WEDNESDAY AFTERNOON...ESPECIALLY ALONG THE FOOTHILLS.
WILL CONTINUE TO MONITOR.
&&
.PREV DISCUSSION... /ISSUED 337 AM MDT TUE MAY 7 2013/
SHORT TERM...WATER VAPOR IMAGERY SHOWING WEAK UPPER TROF
CONTINUING TO SHEAR APART AS IT DRIFTS TO THE NORTH AND
NORTHEAST ACROSS CENTRAL COLORADO. SOME SNOW/RAIN SHOWERS HAVE
BEEN OCCURRING IN THE MOUNTAINS OVERNIGHT AND STILL SOME SHOWERS
MAINLY NORTH OF THE INTERSTATE 70 CORRIDOR AND ALONG THE DIVIDE.
MAINLY MID/UPPER LEVEL CLOUDS OVER THE PLAINS WITH THIS SYSTEM.
EXPECT SHOWERS WILL CONTINUE TO SHIFT NORTHWARD AND DISSIPATE
DURING THE MORNING HOURS OVER THE MOUNTAINS.
WEAK RIDGING ALOFT WILL MOVE IN BY MIDDAY BEHIND THE TROF AS QG
FIELDS SHOWING WEAK SUBSIDENCE AND SLIGHT DRYING. THE MAIN UPPER
LOW NOW MOVING INLAND OFF THE CENTRAL CALIFORNIA COST WILL
APPROACH SOUTHWEST COLORADO LATER TONIGHT AND EXPECT AN INCREASE
IN SHOWERS OVER THE MOUNTAINS LATER TONIGHT WITH INCREASING
ASCENT AHEAD OF THE LOW.
THE MAIN CHANGE TO THIS FORECAST WAS TO LOWER POPS A BIT OVER THE
PLAINS THIS AFTERNOON AND EVENING GIVEN THE SLIGHT DRYING AND
SUBSIDENT AIRMASS. STILL...CAN`T RULE OUT ISOLATED SHOWERS WITH
LINGERING MOISTURE AND SLIGHT INSTABILITY. SURFACE BASED CAPES
GENERALLY UNDER 500J/KG SO STRONG/SEVERE STORMS NOT EXPECTED TODAY
ALONG WITH WEAKLY SHEARED ENVIRONMENT. LITTLE CHANGE IN
TEMPERATURES TODAY VS MONDAY`S READINGS.
LONG TERM...A COOL AND WET PATTERN IS SETTING UP FOR WEDNESDAY
AND THURSDAY AS THE UPPER LOW SLOWLY SPINS NEAR THE FOUR CORNERS
REGION. HIGH PRESSURE FROM THE NORTHERN PLAINS WILL PUSH COOLER
AIR INTO NORTHEASTERN COLORADO AND CREATE UPSLOPE CONDITIONS. THIS
WILL FOCUS THE AVAILABLE MOISTURE NEAR AND AGAINST THE FOOTHILLS
THROUGH THE TWO DAY PERIOD. IN ADDITION...WEAK TO MODERATE UPWARD
QG VERTICAL MOTION IS PROGGED TO REMAIN OVER THE AREA ALL OF
WEDNESDAY. MOST MODELS HAVE OVER AN INCH OF LIQUID FALLING OVER
THIS AREA OVER THE TWO DAY PERIOD...WITH MOST FALLING OVER
WEDNESDAY. CAPE VALUES WILL BE HIGHEST OVER SOUTHEAST COLORADO YET
OUR FORECAST AREA SHOULD STILL SEE ENOUGH FOR WIDESPREAD SHOWERS
AND A SLIGHT CHANCE OF THUNDERSTORMS. HAVE PAINTED HIGHER POPS AND
QPF AMOUNTS OVER THE AREA FOR WEDNESDAY. TEMPERATURES WEDNESDAY WILL
LIKELY BE A FEW DEGREES COOLER OVER TODAYS OVER MOST OF THE AREA
EXCEPT THE FAR NORTHEAST CORNER WHERE ITS LEAST AFFECTED BY
UPSLOPE. EVEN COOLER AIR WILL PUSH DOWN THURSDAY AS ANOTHER
DISTURBANCE SLIDES SOUTH. TEMPERATURES WILL COOL INTO THE 50S OVER
THE PLAINS AND INTO THE 40S IN THE HIGHER TERRAIN. THIS WILL
LIKELY PRODUCE A LITTLE MORE STABILITY AND DECREASE CHANCES OF
THUNDERSTORMS BUT WILL STILL SEE SHOWERS. SNOW LEVELS WILL BE
AROUND 9K TO 10K AS THE UPPER LOW IS OVER/NEAR THE FORECAST AREA.
FRIDAY AND SATURDAY...NORTH TO NORTHWESTERLY FLOW ALOFT WILL KEEP
IN COOLER THAN AVERAGE TEMPERATURES AND SHOWERY WEATHER. SLIGHT
RIDGING ALOFT WILL ALLOW TEMPERATURES TO WARM FRIDAY ABOUT 5
DEGREES...BUT YET ANOTHER DISTURBANCE WILL PRODUCE A PUSH FROM THE
NORTH TO CREATE UPSLOPE COOL CONDITIONS SATURDAY. AVAILABLE
MOISTURE WILL BE LESS WITH THIS SYSTEM SO NOT AS MUCH QPF IS
EXPECTED AT THIS TIME.
STRONGER UPPER RIDGING WILL MOVE OVERHEAD SUNDAY AND INTO TUESDAY
TO WARM TEMPERATURES BACK UP TO NORMAL FOR THIS TIME OF YEAR AND
BRING DRIER WEATHER. THIS PATTERN WAS IN THE GRIDS ALREADY...ONLY
MADE SLIGHT TWEAKS TO THE TEMPERATURES LATE WEEKEND INTO EARLY
NEXT WEEK.
AVIATION...VFR EXPECTED TODAY AND TONIGHT. WITH THE 12Z ISSUANCE
WILL BE REMOVING THE PROB GROUP FOR SHOWERS TODAY AS FEEL ANY
SHOWERS WILL BE MORE ISOLATED IN COVERAGE. SURFACE WINDS STARTING
FROM THE SOUTH AND SOUTHWEST THIS AM BEFORE SHIFTING MORE NORTH TO
NORTHWEST THIS AFTERNOON. SPEEDS WILL BE LIGHT...GENERALLY UNDER
10KT THOUGH THIS EVENING.
HYDROLOGY...SHOWERS WILL GENERALLY BE ON THE LIGHTER SIDE WITH
AMOUNTS UNDER A TENTH OF AN INCH WITH PASSING SHOWERS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1135 PM MDT MON MAY 6 2013
.UPDATE...
ISSUED AT 901 PM MDT MON MAY 6 2013
UPDATED THE FORECAST TO REMOVE POPS OVER THE PLAINS AND LOWER POPS
OVER THE EASTERN MOUNTAINS. BEST CHANCE FOR PRECIP THE NEXT FEW
HOURS WILL BE OVER THE CENTRAL MOUNTAINS...WHERE OBS/SPOTTERS
SUGGEST LIGHT TO MODERATE RAIN/SNOW IS OCCURRING...WITH THE SNOW
LEVEL AROUND 9000 FEET.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
UPPER DISTURBANCE LIES JUST TO THE SOUTH OF CO WITH BANDS OF
CONVECTION ACROSS NORTHERN NEW MEXICO LIFTING NORTHWARD AHEAD OF
THIS FEATURE. WE`VE HAD PERSISTENT -SHRASN ACROSS THE MOUNTAIN
AREAS TODAY...PARTICULARLY ALONG THE CONTDVD WHERE KMYP AND KCPW WEB
CAMS CONTINUE TO SHOW WET SNOW FALLING. KALS HAS ALSO PICKED UP A
BRIEF RAIN SHOWER...AND EVEN KTAD REPORTED SOME LIGHT RAIN WITH A
BAND THAT MOVED OFF THE MOUNTAINS EARLIER THIS AFTERNOON.
MEANWHILE...SFC DEW POINTS ACROSS THE PLAINS HAVE BEEN SLOW TO COME
UP WITH READINGS STILL IN THE LOWER TO MID 20S FOR MOST AREAS.
AS THE SHORTWAVE CONTINUES TO TRACK TO THE NORTH ACROSS THE AREA
THIS EVENING...WILL CONTINUE HIGH POPS ACROSS THE MOUNTAINS WITH
AXIS OF HIGHEST POPS SHIFTING INTO THE NORTH CENTRAL MOUNTAINS
THROUGH THE EVENING. ACROSS THE PLAINS WILL KEEP GENERALLY ISOLATED POPS
IN THE FCST AS HRRR LOOKS OVERDONE WITH QPF FIELDS GIVEN THE SLOW
REBOUND IN SFC DEW POINTS. THE TWO DIVIDES...PALMER AND
RATON...HAVE THE BEST CHANCE AT SEEING SOME MEASURABLE
PRECIPITATION...SO WILL HOLD ON TO SOME SCT POPS FOR THESE AREAS.
WILL BE CONTINUING TO WATCH THE WALDO CANYON BURN SCAR FOR
RAINFALL. MOST LIKELY SCENARIO IS FOR QPF AMOUNTS TO RANGE UP TO
.10...WHICH IS BELOW FLOOD ADVISORY THRESHOLDS. HOWEVER IF A
STRONGER CELL DEVELOPS...THERE COULD BE SOME LOCAL AMOUNTS APPROACH
.20.
AS THE DISTURBANCE LIFTS NORTHWARD...SHOULD SEE IMPROVING CONDITIONS
SPREAD FROM SOUTH TO NORTH OVERNIGHT WITH SOME CLEARING TAKING PLACE
TOWARDS MORNING. HAVE POPS DROPPING INTO THE ISOLATED CATEGORY
OVERNIGHT ACROSS THE CENTRAL AND SOUTHWEST MOUNTAINS AS FORCING IS
WEAK AND WE LOOSE CONVECTIVE INGREDIENT.
STILL LOOKS LIKE THE WARMEST DAY IS ON TAP FOR TUESDAY. ALTHOUGH
SFC DEW POINTS WILL LIKELY RISE INTO THE 30S OVERNIGHT...THEY FALL
AGAIN ACROSS THE SOUTHEAST PLAINS INTO THE 20S...WITH LCLS IN MODEL
SOUNDINGS AROUND H6. FOR THAT REASON...THINK THAT SUB CLOUD DRY
LAYER WILL KEEP ANY RAINFALL ON THE WALDO BURN SCAR FROM REACHING
FLOOD ADVISORY CRITERIA ONCE AGAIN...WITH AMOUNTS LIKELY TO REMAIN
UNDER .10. BUT WITH MORE SUNSHINE ON TUESDAY RESULTING IN BETTER
POTENTIAL INSTABILITY...AND NAM12 HINTING AT A BOUNDARY STALLING
ALONG THE PALMER DIVIDE IN THE AFTERNOON...WALDO WILL NEED TO BE
MONITORED AS CELLS COULD POTENTIALLY BE STRONGER. OVER THE MOUNTAIN
AREAS...KEPT POPS IN THE SCATTERED RANGE AS WE APPEAR TO LACK ANY
STRONG FORCING ALOFT FOR MORE WIDESPREAD PCPN. OTHERWISE...HIGH
TEMPERATURES SHOULD TOP OUT IN THE 70S ACROSS THE PLAINS...WITH 60S
FOR THE VALLEYS...AND GENERALLY 40S AND 50S FOR THE MOUNTAINS. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 308 PM MDT MON MAY 6 2013
INCREASING CONCERNS FOR HEAVIER RAIN POTENTIAL(LOWER ELEVATION
SHOWERS AND THUNDERSTORMS)...INCLUDING OVER THE WALDO CANYON
BURN SCAR(ESPECIALLY FROM WEDNESDAY INTO THURSDAY) AS WELL AS
INCREASING STRONG TO SEVERE WEATHER THREAT OVER PORTIONS OF THE
SOUTHEASTERN COLORADO PLAINS FROM WEDNESDAY INTO WEDNESDAY NIGHT
AND HIGHER ELEVATION SNOWS ARE PRIMARY LONGER TERM METEOROLOGICAL
ISSUES.
RECENT LONGER TERM COMPUTER SIMULATIONS SUGGEST THAT CLOSED UPPER
LOW CENTERED OVER FAR SOUTHERN NEVADA AT 00Z WEDNESDAY MOVES INTO
THE FOUR CORNERS REGION BY 00Z THURSDAY WITH LATEST ECMWF SOLUTION
SLOWLY MOVING THE CLOSED UPPER LOW ACROSS SOUTHERN COLORADO INTO
WESTERN KANSAS BY 06Z FRIDAY WHILE LATEST GFS SUGGESTS THAT CLOSED
UPPER LOW WILL REMAIN IN THE VICINITY OF THE FOUR CORNERS REGION
THROUGH THURSDAY BEFORE DROPPING UPPER LOW SOUTH INTO FAR
SOUTHEASTERN ARIZONA BY 00Z SATURDAY. IN ADDITION...NORTHERLY
SURGES(CAPABLE OF ENHANCING PRECIPITATION POTENTIAL) ARE PROJECTED
TO MOVE ACROSS PRIMARILY EASTERN SECTIONS OF THE CWFA TUESDAY
NIGHT...WEDNESDAY AND THEN AGAIN ON SATURDAY.
BOTH ECMWF AND GFS SOLUTIONS GENERATE HEALTHY AMOUNTS OF
PRECIPITATION OVER THE FORECAST DISTRICT THROUGH THURSDAY
NIGHT...WITH OF COURSE THE GFS MODEL MUCH MORE AGGRESSIVE WITH
RESPECT TO POTENTIAL TOTAL PRECIPITATION AMOUNTS.
PRECIPITATION...HEAVY AT TIMES...WILL BE POSSIBLE OVER MANY
PORTIONS OF THE FORECAST DISTRICT FROM TUESDAY NIGHT INTO AT
LEAST THURSDAY NIGHT AND FLOOD WATCHES MAY BECOME NECESSARY FOR
AREAS SUCH AS THE WALDO CANYON BURN SCAR(ESPECIALLY FROM WEDNESDAY
INTO THURSDAY) IF METEOROLOGICAL TRENDS CONTINUE. WFO PUEBLO WILL
CONTINUE TO MONITOR CLOSELY AND ISSUE HIGHLIGHTS/ADVISORIES
AND/OR HYDRO WARNINGS IF/AS NEEDED.
ANOTHER LONGER TERM CONCERN WILL BE THE POTENTIAL FOR STRONG TO
SEVERE CONVECTION OVER PORTIONS OF THE SOUTHEASTERN COLORADO
PLAINS...ESPECIALLY FROM WEDNESDAY INTO WEDNESDAY NIGHT AS DEEPER
ATMOSPHERIC MOISTURE...LOCALIZED 0 TO 6 KM SHEARS AROUND 30
KNOTS...LOCALIZED CAPES AROUND 2100 J/KG AND LOCALIZED LIS AROUND
-8C RESPECTIVELY ARE ANTICIPATED OVER PORTIONS(ESPECIALLY FAR
EASTERN SECTIONS) OF THE SOUTHEASTERN COLORADO PLAINS. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY AND ISSUE
SEVERE WEATHER PRODUCTS AS NEEDED.
ACCUMULATING SNOW IS ALSO EXPECTED AT TIMES OVER HIGHER TERRAIN
AREAS FROM TUESDAY NIGHT INTO LATER THIS WEEK. WINTER WEATHER
HIGHLIGHTS MAY BECOME NECESSARY OVER HIGHER TERRAIN AREAS DURING
THIS TIME-FRAME(ESPECIALLY OVER PUBLIC ZONES 58/60/66/68/73/75/81
AND 82).
IMPROVING METEOROLOGICAL CONDITIONS IN THE FORM OF WARMING
TEMPERATURES AND DECREASING POPS ARE THEN ANTICIPATED FROM LATER
THIS WEEKEND INTO EARLY NEXT WEEK. COOLEST TEMPERATURES DURING THE
LONGER TERM ARE EXPECTED TUESDAY AND WEDNESDAY WHILE WARMEST LONGER
TERM TEMPERATURES ARE PROJECTED SUNDAY AND NEXT MONDAY. FINALLY...
STILL ANTICIPATE THAT LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1130 PM MDT MON MAY 6 2013
EXPECT VFR CONDITIONS AT ALL TAF SITES TONIGHT THROUGH THE DAY ON
TUESDAY. OVER THE MOUNTAINS...STILL SOME IFR CONDITIONS DUE TO
-SHSN ALONG THE CONTINENTAL DIVIDE THROUGH 10Z...THEN SOME PARTIAL
CLEARING THROUGH MIDDAY TUESDAY AS AREA WILL BE BETWEEN WEATHER
SYSTEMS. SCT -SHRA WILL REDEVELOP OVER THE HIGHER TERRAIN AGAIN
TUE AFTERNOON...LEADING TO BRIEF MVFR/IFR...ESPECIALLY OVER THE
HIGHER PEAKS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1049 PM EDT WED MAY 8 2013
.SYNOPSIS...
WEAK LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK
NORTHEAST AND ACROSS THE AREA ON THURSDAY. A SLOW MOVING COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY AND FRIDAY NIGHT AND
EVENTUALLY PASS EAST SATURDAY NIGHT INTO SUNDAY MORNING. HIGH
PRESSURE THEN RETURNS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ORGANIZED SHOWERS REMAIN N AND W OF THE LOCAL AREA LATE THIS EVE.
HRRR IS PERFORMING WELL AS KEEPS THE AREA DRY UNTIL 08-09Z WHEN A
SHORTWAVE/VORT MAX ASSOCIATED WITH UPPER LOW MOVES TOWARDS THE
REGION. SHOWERS ASSOCIATED WITH THIS FEATURE ARE CURRENTLY OVER
THE DELMARVA PENINSULA AND ETA INTO THE SW PORTION OF THE AREA IS
CURRENTLY TIMED TO BE SLIGHTLY EARLIER (06-08Z) THAN THE HRRR IS
INDICATING. THEREFORE...WILL LEAVE INCREASING POPS AFTER 04Z AS
SCT SHOWERS MAY BEGIN TO DEVELOP AHEAD OF THE MAIN AREA. ALSO
REMOVED THUNDER FROM THE FORECAST TONIGHT WITH ONLY VERY WEAK
INSTABILITY EXPECTED TO BE PRESENT ALOFT.
LIGHT WINDS AND HIGH MOISTURE LEVELS HAVE ALSO CAUSED AREAS OF FG
TO DEVELOP IN COASTAL CT AND EASTERN LI. CHANGED PATCHY FG TO
AREAS FG IN THESE LOCATIONS AND ISSUED AN SPS TO HIGHLIGHT HAZARD.
PATCHY DENSE FOG IS ALSO OUT THERE WHICH MAY WORSEN AS THE NIGHT
PROGRESSES...BUT WOULD EXPECT SOME IMPROVEMENT ONCE THE RAIN MOVES
IN. SO CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE A DENSE FG ADVSY ATTM.
THE ESE FLOW WILL VEER TO A MORE SOUTHERLY FLOW OVERNIGHT AS
THE OCCLUDED FRONT LIFTS NORTH OF THE AREA.
LOWS WILL RANGE FROM THE LOWER TO UPPER 50S. STAYED CLOSE TO MOS
GUIDANCE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THE UPPER LOW TRACKS ACROSS THE AREA ON THU WITH STEEPENING LAPSE
RATES AND PLENTY OF INSTABILITY CLOUDS AND SHOWERS. THE BEST CHANCE
LOOKS TO BE IN THE MORNING WITH THE BEST LIFT AND DEEPEST
MOISTURE. RAINFALL AMOUNTS ARE EXPECTED TO BE LESS THAN ONE-
QUARTER INCH...HOWEVER ISOLATED HIGHER AMOUNTS ARE POSSIBLE WITH
ANY THUNDERSTORMS. THIS ACTIVITY SHOULD NOT BE AS ORGANIZED AS
THE CONVECTIVE BANDS THAT WENT THROUGH THE AREA ON WED.
HIGHS WILL TOP OUT IN THE LOWER 60S AT THE COAST...TO THE LOWER
70S NORTH AND WEST OF NYC. THIS IS CLOSE TO NORMAL. USED A BLEND
OF THE MOS GUIDANCE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
WEAK DEEP-LAYERED RIDGING SHOULD KEEP US DRY FOR MOST OF THE DAY ON
FRIDAY...HOWEVER THERE COULD BE A LATE DAY THUNDERSTORM FROM AROUND
THE CITY AND POINTS WEST. BASED ON 850MB TEMPS...WENT CLOSER TO NAM
MOS HIGH TEMPERATURES...BUT LOWERED THEM BY A FEW DEGREES ALONG THE
SOUTH FACING SHORES.
A COLD FRONT SLOWLY APPROACHES FRIDAY NIGHT WITH A CHANCE OF A
SHOWER OR TSTM...HOWEVER SHOWERS AND POSSIBLE TSTMS LOOK TO
BE MOST LIKELY DURING SATURDAY AND SATURDAY NIGHT WITH THE FRONT
ENTERING THE AREA. BY DAYBREAK ON SUNDAY...THE FRONT IS MOST LIKELY
EAST OF THE CITY...SO JUST A LINGERING SHOWER POSSIBLE SUNDAY
MORNING. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT SUNDAY
AFTERNOON WITH CLEARING SKIES. HIGHS GENERALLY 70-75 ON SATURDAY AND
65-70 ON SUNDAY.
AN UPPER TROUGH SHIFTS INTO THE REGION ON MONDAY/MONDAY NIGHT.
PROBABLY JUST SOME DIURNAL CU BUILDUP...SO WILL KEEP THE FORECAST
DRY FOR NOW. HIGH TEMPS COLDER THAN NORMAL. THE TROUGH SHIFTS EAST
ON TUESDAY WITH MODERATING TEMPERATURES. WILL GO WITH A DRY FORECAST
ON WEDNESDAY FOR NOW...BUT MODELS DEPICT SOME MOISTURE SPILLING OVER
AN UPPER RIDGE TO THE WEST. MAY NEED TO EVENTUALLY INCLUDE CHANCES OF
SHOWERS FOR THIS PERIOD.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
SLOW MOVING LOW PRESSURE WILL MOVE THROUGH THE AREA THROUGH THURSDAY
WITH AN ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH OVERNIGHT.
STRATUS AND FOG HAS DEVELOPED ACROSS LONG ISLAND AND COASTAL
CONNECTICUT ...IFR TO LIFR...AND WILL BECOME MORE WIDESPREAD INTO
THE NEW YORK AREA TERMINALS AFTER 06Z. ANOTHER AREA OF RAIN IS
EXPECTED TO ROTATE INTO THE REGION AFTER 08Z AND CONDITIONS WILL
LIKELY IMPROVE A LITTLE.
AS THE LOW MOVES THROUGH THURSDAY PERIODS OF RAIN WILL BE LIKELY
WITH AN ISOLATED THUNDERSTORM ALSO POSSIBLE. AS THE LOW MOVES TO THE
NORTH OF THE AREA LATE IN THE FORECAST PERIOD...WINDS WILL BECOME
LIGHT FROM THE SOUTH AND SOUTHWEST.
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.THURSDAY NIGHT...IMPROVING CONDITIONS WITH SHOWERS ENDING.
.FRIDAY...CHANCE OF BRIEF MVFR OR LOWER CONDS IN ANY SCT SHOWERS IN
THE AFTERNOON. AN ISOLD TSTM POSSIBLE.
.FRIDAY NIGHT-SUNDAY MORNING...MVFR OR LOWER CONDS LIKELY IN ANY
SHOWERS... MAINLY THROUGH SUNDAY MORNING. AN ISOLD TSTM POSSIBLE SAT
AFTERNOON/EARLY EVENING
.SUNDAY AFTERNOON-MONDAY...VFR.
&&
.MARINE...
UPDATE TO FORECAST TO INCLUDE AREAS OF FOG ON ALL WATERS EXCEPT NY
HARBOR. DO NOT THINK THERE IS WIDESPREAD DENSE FG AS DEWPOINT
TEMPS ARE ONLY A DEGREE HIGHER THAN WATER TEMPS. THIS WILL NEED TO
BE MONITORED OVERNIGHT FOR WORSENING CONDS...ESPECIALLY ONCE THE
OCCLUDED LOW LIFTS N OF THE WATERS. OTHERWISE...SCA FOR HAZARDOUS
SEAS REMAINS IN EFFECT FOR THE OCEAN THROUGH THU. SEAS 4 TO 7 FT
IN A SLY SWELL THROUGH THIS EVENING...BUT THEN BEGIN TO GRADUALLY
SUBSIDE TO BELOW 5 FT THU EVENING. SEAS MAY LINGER ABOVE 5 FT EAST
OF MORICHES INLET FOR A PORTION OF THU NIGHT.
SEAS REMAIN JUST BELOW SCA CRITERIA ON FRIDAY...THEN BUILD UP TO
5 FT FRIDAY NIGHT ON AN INCREASING SW FLOW. GUSTS ON THE OCEAN
WATERS COULD ALSO REACH 25 KT DURING THE DAYTIME ON SATURDAY AND
SATURDAY EVENING AHEAD OF AN APPROACHING COLD FRONT. WINDS AND
SEAS THEN DIMINISH ON SUNDAY AFTER THE PASSAGE OF THE COLD FRONT
WITH SEAS BELOW 5 FT PERHAPS BY THE END OF THE MORNING. AN
OFFSHORE FLOW THEN MAINTAINS SUB SCA CONDITIONS THROUGH MONDAY.
&&
.HYDROLOGY...
AN ADDITIONAL QUARTER INCH IS POSSIBLE THROUGH THU WITH ISOLATED
HIGHER AMOUNTS WITH ANY THUNDERSTORMS. THIS IN ASSOCIATION WITH
THE UPPER LOW TRACKING ACROSS THE AREA.
ANOTHER HALF INCH TO INCH OF RAINFALL IS POSSIBLE FROM LATE
FRIDAY THROUGH SUNDAY MORNING IN ASSOCIATION WITH A SLOWLY-MOVING
COLD FRONT. LOCALLY HIGHER AMOUNTS ARE POSSIBLE WITH
THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
THURSDAY FOR ANZ350-353-355.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
830 PM EDT WED MAY 8 2013
.UPDATE (REST OF TONIGHT AND THURSDAY)...
00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE STUBBORN UPPER LOW
WHICH HAS PLAGUED THE SOUTHEAST CONUS AND EASTERN SEABOARD THE PAST
SEVERAL DAYS CONTINUES TO EJECT NORTHEASTWARD TOWARD THE NEW
YORK/NEW ENGLAND. GENERAL TROUGHING CONTINUES TO EXTEND SOUTHWARD
FROM THIS FEATURE TO THE FL PENINSULA AND EASTERN GULF OF
MEXICO...HOWEVER SHORTWAVE RIDGING IS POISED TO EXPAND OVER OUR
HEADS DURING THE NEXT 24 HOURS IN THE WAKE OF THIS DEPARTING SYSTEM.
AT THE SURFACE...A WEAK GRADIENT IN PLACE ASSOCIATED WITH A NEARBY
RIDGE AXIS ALLOWED A MODERATE SEA-BREEZE CIRCULATION TO DEVELOP
THROUGH THE DAY. THIS STABILIZING FLOW HAS PUSHED MUCH OF THE
AFTERNOON CU INLAND AND LEFT A GENERALLY MOSTLY CLEAR SKY ACROSS
THE REGION THIS EVENING. THIS SEA-BREEZE CIRCULATION WILL SLOWLY
DISSIPATE OVER THE NEXT SEVERAL HOURS WITH THE LOSS OF DIURNAL
HEATING AND THEN REVERSE TO AN OFFSHORE FLOW SOUTH OF TAMPA BAY BY
THE EARLY MORNING HOURS.
THE REST OF THE OVERNIGHT WILL FEATURE THESE MOSTLY CLEAR
SKIES...WINDS BECOMING LIGHT...DRY CONDITIONS...AND TEMPERATURES
DROPPING THROUGH THE 60S FOR MOST LOCATIONS. NORMALLY COLDER INLAND
SPOTS WILL LIKELY SEE UPPER 50S TOWARD SUNRISE.
THURSDAY WILL SEE A SIMILAR DAY TO WEDNESDAY IN TERMS OF SEA-BREEZE
FORMATION...SKY CONDITIONS...AND LOW RAINFALL CHANCES. COLUMN
POTENTIAL IN TERMS OF TEMPERATURE WILL BE INCREASING AS HEIGHTS RISE
THROUGH THE DAY. 850MB TEMPS UP BETWEEN 12-14C SHOULD EASILY MIX
AFTERNOON TEMPERATURES OUT INTO THE MIDDLE 80S AWAY FROM THE
BEACHES. ONSHORE FLOW DURING THE AFTERNOON WILL HOLD TEMPS DOWN AT
THE BEACHES TO THE UPPER 70S/LOWER 80S. ENJOY!
&&
.AVIATION...
VFR CONDITIONS FOR THE NEXT 24 HOURS. THERE MAY BE SOME PATCHY LATE
NIGHT GROUND FOG INLAND...BUT NOT ENOUGH TO IMPACT THE TERMINALS.
LIGHT/VARIABLE WINDS OVERNIGHT SHIFT TO ONSHORE LATE MORNING AND
AFTERNOON.
&&
.MARINE...
SEABREEZE WILL WEAKEN THROUGH THE REMAINDER OF THE EVENING NEAR THE
COAST AND THEN REVERSE TO AN OFFSHORE DIRECTION AFTER MIDNIGHT TO
THE SOUTH OF TAMPA BAY. WITH A HIGH PRESSURE RIDGE STILL IN PLACE
FOR THURSDAY...EXPECT ANOTHER MODERATE ONSHORE SEA-BREEZE OF 10-15
KNOTS TO DEVELOP BY EARLY AFTERNOON NEAR THE COAST WITH LIGHT TO
MODERATE CHOP DEVELOPING ACROSS PROTECTED BAYS AND INLETS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 83 65 87 / 10 0 10 10
FMY 64 87 66 90 / 10 0 10 10
GIF 62 86 66 91 / 10 0 10 10
SRQ 63 81 64 85 / 10 0 10 10
BKV 57 85 55 88 / 0 0 10 10
SPG 68 83 69 86 / 10 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EDT TUE MAY 7 2013
.DISCUSSION...
CURRENT-THIS AFTERNOON...UPPER LEVEL LOW OVER THE SOUTHEAST UNITED
STATES HAS BEEN SLOWLY TRACKING EAST TOWARD THE ATLANTIC AND WAS
OVER WESTERN SOUTH CAROLINA AND NORTHEAST GEORGIA PER THE LATEST
SATELLITE IMAGERY AND RUC ANALYSIS. BAND OF CLOUDS ASSOCIATED WITH A
WEAK UPPER LEVEL DISTURBANCE WAS MOVING EAST SOUTHEAST ACROSS THE
NORTHEAST GULF OF MEXICO AND NORTH FLORIDA. ANOTHER AREA OF MID
LEVEL ENERGY WAS CROSSING THE CENTRAL GULF AND MOVING TOWARD
FLORIDA. THE RUC40 PROGS THESE AREAS TO CROSS OVER CENTRAL FLORIDA
DURING THE AFTERNOON TIME OF MAX HEATING. ALTHOUGH LAYER MOISTURE IS
LIMITED TO AN INCH OR LESS PER THE 12Z UPPER AIR SOUNDINGS...THE
LOWER LAYERS MAY DESTABILIZE ENOUGH DURING THE AFTERNOON FOR A
SLIGHT CHANCE OF PRECIPITATION.
MORNING UPDATE AMENDED THE SURFACE WIND AND RELATED GRIDS. THE REST
OF THE AFTERNOON FORECAST LOOKS GOOD.
PREVIOUS ZONE DISCUSSION
CURRENT-TONIGHT...ANOTHER COOL AND DRY START TO THE DAY WITH
TEMPERATURES MAINLY IN THE 50S APPROACHING 10 DEGREES BELOW SEASONAL
NORMALS. A FAIRLY DRY DAY ON TAP WITH YET ANOTHER WEAK TROUGH
DROPPING SOUTHEASTWARD INTO THE CENTRAL PENINSULA DURING THE DAY.
PRECIPITABLE WATER VALUES WILL STRUGGLE TO REACH 1 INCH...THOUGH
SHORT RANGE MODELS TRY TO SPIT OUT A BIT OF QPF FROM ORLANDO
NORTHWARD THIS AFTERNOON. DEWPOINT VALUES WILL STRUGGLE TO STAY IN
THE LOWER 50S. WILL KEEP POPS JUST UNDER 20 PERCENT FOR LIGHT
PRECIPITATION FROM ORLANDO NORTHWARD BUT THIS MAY BE GENEROUS AS
MOST AREAS WILL REMAIN DRY. LIGHT MORNING WINDS WILL BECOME WESTERLY
AND INCREASE TO 10-15 MPH IN THE AFTERNOON WITH OCCASIONAL HIGHER
GUSTS. IF THERE IS ANY KIND OF SEA BREEZE THIS AFTERNOON IT WILL
LIKELY BE FROM MARTIN COUNTY OR PALM BEACH COUNTY SOUTHWARD. THE
UPPER LOW OVER WESTERN GEORGIA IS FINALLY FORECAST TO MUSTER FORWARD
MOMENTUM AND WILL MOVE ACROSS THE MID ATLANTIC STATES OVER THE NEXT
24 HOURS WHILE UNDERGOING A GRADUAL WEAKENING TREND. WEAK MID LEVEL
IMPULSES PINWHEELING AROUND THE UPPER LOW WILL MOVE ACROSS THE
CENTRAL PENINSULA DURING THE DAY. THIS ENERGY MAY BE JUST ENOUGH TO
SQUEEZE OUT A LITTLE PRECIPITATION OVER OUR NORTHERN AREAS IN THIS
FAIRLY DRY ENVIRONMENT.
HIGHS IN THE UPPER 70S TO LOWER 80S NEAR AND NORTH OF THE I-4
CORRIDOR WITH LOWER 80S FURTHER SOUTHWARD TOWARD LAKE OKEECHOBEE AND
ALONG THE TREASURE COAST. ANOTHER UNSEASONABLY COOL NIGHT ON TAP
WITH LOWS MAINLY IN THE 50S WITH SOME LOWER 60S POSSIBLE NEAR LARGER
METROPOLITAN AREAS AND ALONG THE MARTIN COUNTY COAST.
WED...MID LYR CLOSED LOW AND SFC LOW WILL MOVE NE TWD THE MID ATLC
WITH SFC HIGH PRESSURE RIDGE OFFSHORE FROM S FL AND REDEVELOPING
OVER THE ERN GULF. A DRY AIRMASS WITH PWATS LESS THAN AN INCH AND
LOW LVL WESTERLY FLOW WILL MAKE FOR A MOSTLY DAY WITH HIGHS IN THE
LOWER 80S ALONG THE COAST TO MID 80S OVER THE INTERIOR.
WED NIGHT...EXPECT MOSTLY CLEAR SKIES WITH SFC HIGH PRESSURE ACROSS
THE CENTRAL PENINSULA. LOWS IN THE UPPER 50S TO LOWER 60S.
THU...HIGH PRESSURE ACROSS CENTRAL FL...A DRY AIRMASS AND WEAK LOW
LVL FLOW WILL ALLOW WELL DEVELOPED AFTERNOON SEA BREEZE BOUNDARIES
TO PUSH INLAND. SHORT RANGE MODELS HINTING AT SOME LIGHT QPF ACROSS
INLAND MARTIN AND ST LUCIE BUT THINK OVERALL DRY AIRMASS WILL LIMIT
THE POSSIBILITY FOR DEEP CONVECTION AND WILL KEEP POPS BELOW
MENTIONABLE RANGE AT FOR NOW. HIGHS WILL WARM INTO THE LOWER TO MID
80 ALONG THE COAST AND MID-UPPER 80S FOR THE INTERIOR.
FRI...SFC RIDGE EXTENDING FROM THE ATLC INTO THE ERN GULF WITH LOW
LVL SE FLOW DEVELOPING. ECMWF CONTINUES DRY FORECAST WITH GFS
SHOWING VERY LOW PRECIP CHANCES. WILL CONTINUE DRY FORECAST AT THIS
POINT WITH HIGHS IN THE MID 80S COAST TO NEAR 90 OVER THE INTERIOR.
SAT-TUE...MAIN CHANGE IN 00Z MODELS TONIGHT IS SHOWING A BIT HIGHER
MOISTURE LEVELS AND INSTABILITY SUNDAY FOR SCATTERED STORMS ACROSS
NRN SECTIONS SO BUMPED UP POPS A BIT ACROSS THE NORTH SUNDAY
AFTERNOON. FOR SATURDAY...SHOULD SEE SOME LATE AFTERNOON ISOLATED
SEA BREEZE STORMS FROM NEAR LAKE OKEECHOBEE NNE TOWARD COASTAL
VOLUSIA LATE IN THE DAY. SUNDAY INTO MONDAY...FRONT MOVING THROUGH
THE STATE WILL BRING SCATTERED SHOWERS AND STORMS SUNDAY WITH FRONT
MOVING THROUGH THE FORECAST AREA EARLY MONDAY WITH A CONTINUED
CHANCE OF SHOWERS AND STORMS. FOR TUESDAY...GFS/ECMWF INDICATE SFC
FRONT WILL MOVE TOWARD S FL WITH NE OR EASTERLY ONSHORE FLOW. WILL
KEEP A SLIGHT CHANCE SHOWER CHANCE ACROSS THE NORTH AND A CHANCE FOR
A SHOWER OR STORM ACROSS SRN SECTIONS WHERE DEEPER MOISTURE WILL
LIKELY LINGER ON TUESDAY.
&&
.AVIATION...
VFR. SLIGHT CHANCE OF AN AFTERNOON RAIN SHOWER BETWEEN 18Z-24Z PER
RECENTLY UPDATED WEATHER GRID.
&&
.MARINE...
CURRENT-THIS AFTERNOON...BUOY 41009 WAS RECORDING WESTERLY WINDS AT
10 TO 15 KNOTS AND 4 FOOT SEAS WITH A 3 FOOT LONG PERIOD SWELL
COMPONENT. THE WIND RIGHT AT THE BEACHES/NEARSHORE MAY TAKE ON A
SOUTHERLY COMPONENT DURING THE AFTERNOON AS THE BOUNDARY LAYER WINDS
REMAIN STRONG ENOUGH TO HINDER ANY SEA BREEZE THAT DOES DEVELOP FROM
PUSHING ON LAND.
CURRENT AFTERNOON FORECAST LOOKS TO BE ON TRACK.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...WESTERLY WINDS CONTINUE THROUGH THE PERIOD
WITH SPEEDS INITIALLY AROUND 15 KTS EARLY THIS MORNING DECREASING TO
AROUND 9-12 KTS AROUND DAYBREAK FOR THE REMAINDER OF THE DAY. SEAS 3
TO 5 FEET...MOSTLY IN AN ENE SWELL.
SFC RIDGE BUILDING NEAR THE WATERS FROM WED-FRI WILL ALLOW WINDS TO
DROP TO 5-10 KNOTS...EXCEPT SLIGHTLY STRONGER NEAR THE COAST EACH
AFTERNOON WITH DEVELOPING EAST COAST SEA BREEZE. SEAS 3-4 FT WED IN
A NE SWELL WILL DIMINISH TO 2-3 FT THU INTO FRI. SLIGHTLY STRONGER
SE FLOW FRIDAY AFTERNOON WITH A SLIGHT CHANCE OF LATE DAY SHOWERS OR
STORMS NORTH OF THE CAPE...THEN SCATTERED SHOWERS AND STORMS SUNDAY
INTO MONDAY ACROSS THE WATERS.
&&
.FIRE WEATHER...
TODAY...RH VALUES EXPECTED TO FLIRT WITH 35 PERCENT OR LESS FOR 1-3
HOURS ACROSS THE INTERIOR. ENERGY RELEASE COMPONENT (ERC) VALUES ARE
IN THE UPPER TEENS AND 20S EVERYWHERE EXCEPT FOR BREVARD COUNTY`S
ERC OF 30. THE 20 FOOT WIND VALUES TOP OUT AT AROUND 12 MPH FROM THE
WEST AND SOUTHWEST THIS AFTERNOON.
PREVIOUS FIRE WEATHER DISCUSSION
MIN RHS IN THE 35-40 RANGE FOR THE INTERIOR WED-FRI BUT WINDS
EXPECTED TO REMAIN BELOW 15 MPH.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
535 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL CONTINUE TO DRIFT TO OUR NE THROUGH
THURSDAY...GRADUALLY REDUCING OUR RAIN CHANCES. EXPECT MOISTURE
INCREASE AND THE NEXT FRONTAL SYSTEMS TO AFFECT OUR REGION LATE
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE THIS AFTERNOON...SOME DRIER AIR ENTERED THE REGION FROM
THE WEST AROUND THE UPPER LOW TO THE NORTH IN NORTH CAROLINA.
WITH AN AREA OF SHOWERS AND MAYBE AN EMBEDDED THUNDERSTORM OR
TWO MOVING SOUTHEAST INTO THE NORTH PART OF THE FORECAST AREA
AND LAPS LIS -4 AND RUC13 SHOWING FAIRLY HIGH POPS IN THE NORTH
DECIDED TO INCREASE POPS TO 60-80 PERCENT NORTH FOR 2-3 HOURS
AND 30-50 PERCENT CENTRAL AND SOUTH PORTION. THERE WERE SEVERAL
REPORTS OF SMALL HAIL AND ONE OF DIME SIZED HAIL IN RICHLAND
COUNTY. WILL DROP POPS BACK TO 20-30 PERCENT THIS EVENING AS
SUN GOES DOWN AND SURFACE HEATING DIMINISHES. OTHERWISE...
AFTERNOON TEMPERATURES STILL OK.
TONIGHT...UPPER LEVEL STAYS TO THE NORTH AND LEFTOVER LOW LEVEL
MOISTURE MAY LEAD TO SOME FOG DEVELOPMENT AFTER MIDNIGHT. HOWEVER
WIDESPREAD DENSE FOG IS NOT ANTICIPATED AT THIS TIME. CONSENSUS
OVERNIGHT LOWS IN THE LOWER 50S WERE CONTINUED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
UPPER LOW WILL SLOWLY DRIFT TO THE NE ACROSS THE MID ATLANTIC REGION
AND INTO NEW ENGLAND. LINGERING TROUGHINESS AND WEAK IMPULSES IN ITS
WAKE WILL REMAIN ALONG THE EAST COAST. PRECIPITABLE WATER VALUES ARE
PROGGED TO REMAIN AROUND OR JUST OVER ONE INCH...NEAR CLIMO. BEST
MOISTURE AND LOWER UPPER HEIGHTS/TEMPS WILL BE ACROSS OUR
NORTHERN FA. PREMISE FOR LESS MID AND UPPER CLOUDINESS AND WARMER
TEMPS COULD RESULT IN WEAK DIURNAL INSTABILITIES...AND POTENTIAL
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. CHANCE POPS
FAVORING THE NORTHERN FA APPEAR IN ORDER.
MODEL POPS LOWER THU...GIVEN EXPECTATIONS OF LESS INSTABILITY AS
UPPER HEIGHTS/TEMPS CONTINUE TO RISE. FORECAST SOUNDINGS INDICATE
WEAK DIURNAL INSTABILITY...BUT INDICATIONS OF WEAK NVA PSBL BY
AFTN. ISO TO SLIGHT CHANCE SHOWER POSSIBLE...BUT DID NOT INCLUDE
AT THIS TIME DUE TO LOW CONFIDENCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE WEAK UPPER RIDGE OVER THE EAST COAST THU
NT/FRIDAY...TO BE REPLACED BY UPPER TROUGH OVER THE EASTERN CONUS
FRI NT THRU MONDAY. MODELS PROG MOISTURE INCREASE FOR OUR REGION
AHEAD OF A WEAK FRONT BY LATE FRI...WITH ADDITIONAL MOISTURE AND A
STRONGER FRONT COMING IN OVER THE WEEKEND. MODEL CONSENSUS INDICATES
CHANCE POPS IN ORDER. MODELS AGREE ON PUSHING THE FRONT OFFSHORE BY
MON WITH HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
ACCEPTED BLEND OF MOS AND HPC GUIDANCE.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE CONTINUES TO SPIN TO THE NORTH OF THE REGION.
SOME DRIER AIR ENTERED FROM THE WEST. CONVECTIVE ACTIVITY IS
SITUATED NORTH OF THE TAF SITES...SO MAINLY VFR CONDITIONS ARE
EXPECTED LATE THIS AFTERNOON AND EVENING. CONVECTIVE ACTIVITY
SHOULD DIMINISH WITH THE LOSS OF SURFACE HEATING. NEXT MAJOR
CONCERN WILL BE FOG DEVELOPMENT AFTER MIDNIGHT. FOG IS EXPECTED
TO DEVELOP 06Z-12Z. SINCE AGS/OGB ARE MORE FOG- PRONE...HAVE
INCLUDED MVFR FOG. VFR ALL SITES AFTER 12Z-13Z WEDNESDAY MORNING
AS THE LOW PRESSURE SYSTEM LIFTS NORTH OF AREA. HOWEVER...WILL
CONTINUE TO MONITOR MODELS FOR MORE SIGNIFICANT FOG.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SATURDAY AND
SATURDAY NIGHT AS A COLD FRONT MOVES INTO THE REGION.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS CONTINUE AT SEVERAL LOCATIONS. DETAILS CAN
BE OBTAINED FROM OUR RIVER FLOOD STATEMENTS...ON OUR WEBSITE...AND
ON NOAA WEATHER RADIO.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
522 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL CONTINUE TO DRIFT TO OUR NE THROUGH
THURSDAY...GRADUALLY REDUCING OUR RAIN CHANCES. EXPECT MOISTURE
INCREASE AND THE NEXT FRONTAL SYSTEMS TO AFFECT OUR REGION LATE
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE THIS AFTERNOON...SOME DRIER AIR ENTERED THE REGION FROM
THE WEST AROUND THE UPPER LOW TO THE NORTH IN NORTH CAROLINA.
WITH AN AREA OF SHOWERS AND MAYBE AN EMBEDDED THUNDERSTORM OR
TWO MOVING SOUTHEAST INTO THE NORTH PART OF THE FORECAST AREA
AND LAPS LIS -4 AND RUC13 SHOWING FAIRLY HIGH POPS IN THE NORTH
DECIDED TO INCREASE POPS TO 60-80 PERCENT NORTH FOR 2-3 HOURS
AND 30-50 PERCENT CENTRAL AND SOUTH PORTION. THERE WERE SEVERAL
REPORTS OF SMALL HAIL AND ONE OF DIME SIZED HAIL IN RICHLAND
COUNTY. WILL DROP POPS BACK TO 20-30 PERCENT THIS EVENING AS
SUN GOES DOWN AND SURFACE HEATING DIMINISHES. OTHERWISE...
AFTERNOON TEMPERATURES STILL OK.
TONIGHT...UPPER LEVEL STAYS TO THE NORTH AND LEFTOVER LOW LEVEL
MOISTURE MAY LEAD TO SOME FOG DEVELOPMENT AFTER MIDNIGHT. HOWEVER
WIDESPREAD DENSE FOG IS NOT ANTICIPATED AT THIS TIME. CONSENSUS
OVERNIGHT LOWS IN THE LOWER 50S WERE CONTINUED.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
UPPER LOW WILL SLOWLY DRIFT TO THE NE ACROSS THE MID ATLANTIC REGION
AND INTO NEW ENGLAND. LINGERING TROUGHINESS AND WEAK IMPULSES IN ITS
WAKE WILL REMAIN ALONG THE EAST COAST. PRECIPITABLE WATER VALUES ARE
PROGGED TO REMAIN AROUND OR JUST OVER ONE INCH...NEAR CLIMO. BEST
MOISTURE AND LOWER UPPER HEIGHTS/TEMPS WILL BE ACROSS OUR
NORTHERN FA. PREMISE FOR LESS MID AND UPPER CLOUDINESS AND WARMER
TEMPS COULD RESULT IN WEAK DIURNAL INSTABILITIES...AND POTENTIAL
FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. CHANCE POPS
FAVORING THE NORTHERN FA APPEAR IN ORDER.
MODEL POPS LOWER THU...GIVEN EXPECTATIONS OF LESS INSTABILITY AS
UPPER HEIGHTS/TEMPS CONTINUE TO RISE. FORECAST SOUNDINGS INDICATE
WEAK DIURNAL INSTABILITY...BUT INDICATIONS OF WEAK NVA PSBL BY
AFTN. ISO TO SLIGHT CHANCE SHOWER POSSIBLE...BUT DID NOT INCLUDE
AT THIS TIME DUE TO LOW CONFIDENCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE WEAK UPPER RIDGE OVER THE EAST COAST THU
NT/FRIDAY...TO BE REPLACED BY UPPER TROUGH OVER THE EASTERN CONUS
FRI NT THRU MONDAY. MODELS PROG MOISTURE INCREASE FOR OUR REGION
AHEAD OF A WEAK FRONT BY LATE FRI...WITH ADDITIONAL MOISTURE AND A
STRONGER FRONT COMING IN OVER THE WEEKEND. MODEL CONSENSUS INDICATES
CHANCE POPS IN ORDER. MODELS AGREE ON PUSHING THE FRONT OFFSHORE BY
MON WITH HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
ACCEPTED BLEND OF MOS AND HPC GUIDANCE.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE AT THE SURFACE AND ALOFT CONTINUE TO SPIN OVER THE
REGION THIS AFTERNOON.
MAINLY VFR THROUGH THE EVENING HOURS. SCATTERED CONVECTION WILL
AFFECT THE TAF SITES THIS AFTERNOON AND EVENING IN UNSTABLE AIR
MASS. MVFR OR LOWER CONDITIONS POSSIBLE IN CONVECTION. THE
PROBABILITY OF OCCURRENCE OF THUNDER AT ANY ONE TAF SITE IS TOO LOW
TO INCLUDE. CONVECTION WILL DIMINISH WITH SUNSET. PATCHY FOG TO
DEVELOP 06Z-13Z. SINCE AGS/OGB ARE MORE FOG-PRONE...HAVE INCLUDED
MVFR FOG. VFR ALL SITES AFTER 08/13Z AS THE LOW PRESSURE SYSTEM
LIFTS NORTH OF AREA.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SATURDAY AND
SATURDAY NIGHT AS A COLD FRONT MOVES INTO THE REGION.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS CONTINUE AT SEVERAL LOCATIONS. DETAILS CAN
BE OBTAINED FROM OUR RIVER FLOOD STATEMENTS...ON OUR WEBSITE...AND
ON NOAA WEATHER RADIO.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
334 PM EDT TUE MAY 7 2013
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MAIN FORECAST CONCERN IN THE SHORT TERM IS ASSOCIATED WITH SOME
LINGERING MOISTURE AND WEAK VORT MAXS ROTATING AROUND THE PERSISTENT
UPPER LOW CURRENTLY SITUATED ACROSS THE CAROLINAS. SO FAR THIS
AFTERNOON...IT HAS ALLOWED FOR ENHANCED CU FIELD DEVELOPMENT AND
SOME ISOLATED SHOWERS AND STORMS JUST EAST OF THE CWA. THERE IS
ENOUGH ELEVATED INSTABILITY TO MAINTAIN THE LOW END CHANCE FOR
ISOLATED THUNDERSTORMS MAINLY ACROSS PORTIONS OF THE EAST THROUGH
THE REST OF TODAY.
FOR TONIGHT...POPS SHOULD BE ON THE DECREASE ACROSS THE NORTHEAST.
WITH GUIDANCE LIKELY UNDERDOING THE SFC MOISTURE PRESENT FROM RECENT
RAINFALL...THERE IS A GOOD CHANCE FOR FOG DEVELOPMENT UNDER THE CALM
TO LIGHT WINDS IN THE EARLY MORNING HOURS. GUIDANCE IS IN GENERAL
AGREEMENT WITH SOME LOW LEVEL MOISTURE ADVECTING INTO THE FAR
NORTHERN PORTION NEAR 12Z. SHORT RANGE ENSEMBLE RESTRICTED VSBY
PROBS AND RUC CONDENSATION PRESSURE DEFICIT SUPPORT THE GREATEST
CHANCE FOR MORE WIDESPREAD FOG DEVELOPMENT TO BE IN THE FAR NORTH OR
NORTHWEST. CONFIDENCE IS LOW AT THIS POINT ON DENSE FOG DEVELOPMENT
AND WILL MENTION PATCHY FOG AREA-WIDE FOR NOW.
AS UPPER LOW FINALLY BEGINS ITS EXIT NEWD AND WEAK RIDGING
TEMPORARILY BUILDS IN...HAVE TRENDED POPS TO MAINLY BE FOCUSED IN
THE FAR NORTH AND NORTHEAST THROUGH WEDNESDAY NIGHT. FORECAST
MUCAPE VALUES SUGGEST ISOLATED THUNDERSTORM DEVELOPMENT IS
POSSIBLE AGAIN DURING THE AFTERNOON WEDNESDAY.
FOR TEMPS...A GENERAL BLEND IN THE SHORT TERM GUIDANCE LOOKED
REASONABLE AS THE FORECAST AREA SHOULD CONTINUE A GRADUAL WARM-UP
AHEAD OF THE NEXT SYSTEM DURING THE WEEKEND.
BAKER
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HAVE MADE NO CHANGES TO THE EXTENDED. MODELS AGREE O BRIEF BREAK
FOR MUCH OF THE CWA WEDNESDAY NIGHT INTO THURSDAY WITH RAIN
CHANCES INCREASING AGAIN ON FRIDAY. SERIES OF SHORT WAVES SHOULD
KEEP CHANCE OF RAIN ACROSS THE FORECAST AREA THROUGH SUNDAY...WITH
DRYING SUNDAY INTO MONDAY WITH PASSAGE OF A SURFACE FRONT. HAVE
INCLUDED THE PREVIOUS LONG TERM DISCUSSION BELOW.
41
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
/ISSUED AT 411 AM EDT TUE MAY 7 2013/
BY WEDNESDAY NIGHT...PESKY UPPER LOW MOVES UP OVER THE MID
ATLANTIC STATES...WITH RESIDUAL MOISTURE ACROSS NORTH AND
NORTHEAST GEORGIA. BRIEF REPRIEVE EXPECTED ACROSS THE REMAINING
CWA THURSDAY INTO FRIDAY AHEAD OF THE NEXT BATCH OF RAIN. EXTENDED
MODELS STILL SHOWING COMBINATION OF ENHANCED MOISTURE FROM DEEP
SOUTHERLY FLOW AND SERIES OF UPPER LEVEL DISTURBANCES WILL BRING
BACK TO THE STATE BY FRIDAY AHEAD OF FRONT PUSHING THROUGH THE
STATE OVER THE WEEKEND. HAVE OPTED TO INCREASE POPS SLIGHTLY
FRIDAY...WITH GOOD CHANCE NORTH WITH SLIGHT CHANCE THROUGH THE
METRO AREA. HAVE CONTINUED WITH INCREASING TREND INTO SATURDAY
WITH LIKELY POPS NORTH AND GOOD CHANCE ACROSS MUCH OF THE REST OF
THE AREA. THUNDERSTORMS LOOK TO BE LIKELY WITH THIS EVENT WITH
GOOD MODEL AGREEMENT WITH THE INSTABILITY...ESPECIALLY SATURDAY.
MODELS CONTINUE TO DIFFER ON THE AMOUNT OF QPF EXPECTED FRIDAY
THROUGH SUNDAY...WITH THE WETTER ECMWF SHOWING LARGE PORTION OF
WESTERN GEORGIA COULD SEE 0.75 TO 1.25 INCHES WITH ISOLATED HIGHER
AMOUNTS...AND THE GFS SHOWING NORTH GEORGIA COULD SEE WIDESPREAD
0.5 INCHES...WITH PORTIONS OF NORTHWEST GEORGIA SEEING UP TO AN
INCH. HAVE GENERALLY GONE WITH THE GFS SOLUTION FOR QPF...WHICH
MAY BE WISHFUL THINKING AFTER THIS VERY WET WEEKEND ACROSS THE
STATE.
NEAR NORMAL TEMPERATURES ARE EXPECTED WEDNESDAY AND THURSDAY
MORNING...WITH WARM UP BY WEDNESDAY AFTERNOON TO ABOVE NORMAL
TEMPERATURES WHICH WILL REMAIN IN PLACE INTO THE WEEKEND. PRECIP
ACTIVITY SATURDAY AND SUNDAY WILL KEEP TEMPERATURES CLOSER TO
SEASONAL.
31
AVIATION...
18Z UPDATE...
MAINLY VFR CONDITIONS TO START OUT THIS AFTERNOON WITH SOME
LINGERING CIGS IN THE UPPER MVFR RANGE. CIGS SHOULD GENERALLY
SCATTER AND REMAIN NEAR 5 KFT INTO THE OVERNIGHT WITH SOME
POTENTIAL LOWERING FROM 10-15Z. SOME LINGERING SURFACE MOISTURE
WITH CALM TO LIGHT WINDS IN THE EARLY MORNING WILL BRING A
POTENTIAL FOR FOG DEVELOPMENT...THOUGH CONFIDENCE IS LOW AND BEST
CHANCE OF SIGNIFICANT LOWERING SHOULD BE NW OF KATL.
OTHERWISE...WINDS SHOULD BE MOSTLY WEST AT 8 KTS OR LESS DURING
THE DAYTIME.
//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE ON EARLY MORNING CIGS AND VSBYS.
HIGH CONFIDENCE ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 51 78 56 84 / 20 20 10 10
ATLANTA 54 77 59 81 / 10 10 5 10
BLAIRSVILLE 49 71 51 77 / 30 30 20 20
CARTERSVILLE 50 76 54 81 / 10 10 10 10
COLUMBUS 54 80 60 85 / 5 10 5 5
GAINESVILLE 52 74 56 80 / 20 20 20 10
MACON 49 79 56 84 / 10 10 10 5
ROME 50 77 53 83 / 10 10 10 10
PEACHTREE CITY 48 78 53 82 / 10 10 5 5
VIDALIA 55 80 61 85 / 5 10 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....41
AVIATION...BAKER
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
642 PM CDT WED MAY 8 2013
.UPDATE...
ISSUED AT 636 PM CDT WED MAY 8 2013
UPDATED THE AVIATION SECTION FOR THE 00Z TAF ISSUIANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM CDT WED MAY 8 2013
THE LATEST AVAILABLE HRRR OUTPUT DEVELOPS AT LEAST SCATTERED
CONVECTION AHEAD OF THE MCV MOVING OVER CENTRAL MISSOURI. STARTING
TO SEE SOME ENHANCEMENT ON VISIBILTY SATELLITE IMAGERY AND SOME
SHOWER DEVELOPMENT TO OUR WEST/NORTHWEST ON RADAR. DECIDED TO
INCREASE POPS UP TO LOWER CHANCE LEVELS COMING OUT OF THE OZARK
FOOTHILLS THROUGH SUNSET. THE HRRR DISSIPATES THE STRONGER
ELEMENTS AS THEY APROACH THE MISSISSIPPI RIVER AROUND 02Z.
FOLLOWED THE HRRR CLOSELY INTO THE EVENING...AND WILL HAVE A DRY
FORECAST BY 03Z. ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST
INDIANA AND THE PENNYRILE THIS AFTERNOON SHOULD DISSIPATE OR MOVE
SOUTH/EAST OF THE AREA BY SUNSET.
THE 12Z MODELS ARE TRENDING DRIER FOR LATER TONIGHT AND ESPECIALLY
THURSDAY. SOUNDINGS INDICATE THAT A WEAK CAP WILL BE SUFFICIENT TO
KEEP MOST AREAS DRY...DUE TO A GENERAL LACK OF DEEP MOISTURE OR
MAJOR FORCING. WILL SPREAD GOOD CHANCE POPS EASTWARD ALONG THE
I-64 CORRIDOR THROUGH THE MORNING AND KEEP THEM AT THAT LEVEL THERE
THROUGH THE AFTERNOON AND INTO THE EVENING. THIS AREA WILL BE
CLOSEST TO ANY EFFECTS OF MID/UPPER LEVEL DISTURBANCES AND THE
FRONT ITSELF. WOULD BE VERY SURPRISED TO SEE ANYTHING MORE THAN A
VERY ISOLATED STORM PULSE UP TO NEAR SEVERE LEVELS ALONG I-64
THURSDAY AFTERNOON. WILL KEEP SLIGHT CHANCES TO THE SOUTH JUST IN
CASE WE DESTABILIZE ENOUGH FOR A PARCEL TO BREAK THROUGH DURING
THE AFTERNOON.
THURSDAY WILL SEE INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS...AS THE COLD FRONT AND IMPACTS OF THE PRIMARY
MID/UPPER LEVEL DISTURBANCE APPROACH THE AREA. THE LLJ WILL
INCREASE TO AROUND 35KTS...WHICH SHOULD HELP TO BRING SOME
BETTER...DEEPER MOISTURE NORTHEAST ACROSS MUCH OF THE AREA. WILL
HAVE A SOUTHWEST TO NORTHEAST BAND OF LIKELY POPS OVER SOUTHEAST
MISSOURI AND SOUTHERN ILLINOIS LATE IN THE EVENING...AND THEN MOVE
IT SLOWLY EASTWARD ACROSS THE REMAINDER OF THE AREA OVERNIGHT.
THE MODELS SEEM TO HAVE CONVERGED FOR FRIDAY. A WEAK COLD FRONT
WILL SLOWLY PUSH EASTWARD ACROSS THE AREA THROUGH THE DAY AND
SHOULD CLEAR THE ENTIRE AREA BY EARLY EVENING. WITH THE FRONT AND
THE MAIN MID/UPPER DISTURBANCE OVER THE AREA FRIDAY...LIKELY POPS
SEEM WARRANTED...WITH AN EMPHASIS OVER WEST KENTUCKY. A LACK OF
FORCING...ONLY WEAK INSTABILITY...AND GENERALLY WEAK WIND PROFILES
SHOULD KEEP ANY CONVECTION WELL BELOW SEVERE LIMITS. SOME VERY
LOCALIZED HEAVY RAINFALL SHOULD BE THE PRIMARY CONCERN FRIDAY.
POPS WILL LINGER INTO FRIDAY EVENING...MAINLY IN THE EAST...BUT
THE MODEL CONSENSUS IS FOR THE ENTIRE AREA TO BE DRY BY 06Z SATURDAY.
AS FOR TEMPERATURES...WENT ON HIGH END OF GUIDANCE FOR HIGHS
THURSDAY...AND TOWARD THE COOL SIDE FRIDAY. WENT A BIT ABOVE
GUIDANCE FOR LOWS FRIDAY NIGHT. OTHERWISE...CONSENSUS OF GUIDANCE
SHOULD BE FINE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM CDT WED MAY 8 2013
OVER THE WEEKEND...A CLOSED LOW OVER ONTARIO AT THE START OF THE
PERIOD...MOVES EAST AND ENDS UP CARVING A DEEP TROUGH OVER THE GREAT
LAKES AND DOWN INTO OUR REGION. A SECONDARY FRONT MOVES SOUTH TOWARD
US ON SATURDAY AND WHILE IT SEEMS TO START OUT WITH ENOUGH MOISTURE
TO OUR NORTH...BY THE TIME THE FRONT GETS HERE SATURDAY
EVENING...NOT MUCH MOISTURE IS LEFT. SO OPTED TO REMOVE ALL POPS FOR
SATURDAY.
BEHIND THE SECONDARY COLD FRONT...MUCH COOLER AIR WILL FILTER INTO
THE AREA SATURDAY NIGHT AND INTO SUNDAY...ON THE NOSE OF SFC HIGH
PRESSURE FROM CANADA. THE 00Z/12Z ECMWF AND 06Z/12Z GFS INDICATE
850MB TEMPS AT OR BELOW ZERO IN OUR FAR NORTHERN COUNTIES.
HOWEVER...SINCE HIGH PRESSURE WILL STILL BE MOVING IN...THE WIND
WILL LIKELY STAY UP WHICH WILL PREVENT US FROM DROPPING TOO LOW ON
OUR LOW TEMPS FOR SATURDAY NIGHT.
THE SFC HIGH WILL FINALLY BEGIN TO SETTLE OVER THE AREA ON SUNDAY
AND SUNDAY NIGHT...WITH ALL INDICATIONS THAT THE CENTER OF THE HIGH
WILL BE DIRECTLY OVER US ON 12Z MONDAY. WITH COLD AIR ADVECTION IN
FULL SWING ON SUNDAY...WOULD VENTURE TO GUESS WE WILL NOT GET OUT OF
THE 60S FOR HIGHS. THE COLDEST AIR WILL BE SITUATED OVER OUR
NORTHEASTERN COUNTIES (NAMELY SE IL...SWIN...PENNYRILE). LOOKING AT
CIPS ANALOG DATA ALONG WITH RECORDS FROM XMACIS...WE COULD BE
LOOKING AT LOWS SUNDAY NIGHT FALLING INTO THE UPPER 30S FOR THESE
PORTIONS OF OUR AREA IF THE GFS IS CORRECT. 850 MB TEMPS OFF THE GFS
AND THE GFS ENSEMBLE MEAN ARE A BIT COOLER THAN THE ECMWF...AND WITH
CALM WINDS AND CLEAR SKIES...WE COULD DROP QUITE A BIT. LOOKING AT
RAW MODEL DEWPOINT TEMPS...THIS ALSO SUPPORTS THESE COOLER
TEMPS...WHICH COULD GET CLOSE TO TYING RECORDS IN THE EVV AREA.
ELSEWHERE THOUGH...IT STILL LOOKS COOL WITH LOWS IN THE LOWER 40S.
AGAIN...THIS MAY BE COLD ENOUGH TO SUPPORT THE FORMATION OF VERY
PATCHY FROST IN OUTLYING AREAS...BUT A WIDESPREAD FROST IS STILL NOT
ANTICIPATED ATTM.
THE SFC HIGH MOVES EAST AND EVENTUALLY SOUTH ON MONDAY/MONDAY NIGHT AND
THAT IS WHEN THE WARM UP WILL BEGIN. DEPENDING ON HOW LOW WE START
THE DAY WITH ON MONDAY...WE WILL STILL BE COOL WITH HIGHS REMAINING
IN THE 60S/POSSIBLY AROUND 70 FAR WEST. THE FLOW IN THE LOW LEVELS
BECOMES SOUTHERLY/SOUTHWESTERLY LATE MONDAY NIGHT INTO TUESDAY AND
850 MB TEMPS WILL RISE STEADILY FROM THEN THROUGH THE END OF THE
EXTENDED PERIOD (WEDNESDAY). THEREFORE...WE EXPECT HIGHS IN THE 70S
ON TUESDAY WITH AROUND 80 ON WEDNESDAY. THIS EARLY WEEK PERIOD
CONTINUES TO BE DRY. LOOKING BEYOND THAT...MODELS TRY TO BRING A
FRONT INTO THE AREA BUT DIFFER ON TIMING.
&&
.AVIATION...
ISSUED AT 636 PM CDT WED MAY 8 2013
VFR CONDITIONS EXPECTED AT ALL SITES THROUGH THE PERIOD. SMALL
CHANCE OF SHRA/TSRA AFT 15Z AT ALL SITES BUT TOO SMALL TO MENTION
IN TAFS. VARIABLE WINDS AOB 5 KTS WILL PICK UP OUT OF THE SOUTH AT
10-15KTS WITH GUSTS OF 15-24 KTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...JP
PUBLIC...DB
AREA FORECAST DISCUSSION
NWS GRAY ME
942 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...THE FOG AND LOW CLOUDS ARE QUICKLY DISSIPATING INLAND FROM
THE COAST SO FORECAST WAS UPDATED TO GO MOSTLY SUNNY THIS MORNING
OVER INTERIOR SPOTS. SOME PATCHY LOW STRATUS AND FOG LINGER IN
THE PORTLAND AND COASTAL AREAS BUT WILL SOON DISSIPATE OVER ALL
AREAS EXCEPT THE CAPES AND ISLANDS GIVING WAY TO A MOSTLY SUNNY
DAY.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER
AREA FORECAST DISCUSSION
NWS GRAY ME
841 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...STRATUS AND FOG HAVE EXTENDED WELL INLAND SO INCLUDED
SOME FOG THROUGH MID MORNING AS FAR INLAND AS THE MOUNTAINS.
HOWEVER LATEST SATELLITE IMAGERY SHOWS FOG BEGINNING TO RAPIDLY
DISSIPATE SO EXPECT SKIES TO CLEAR IN ALL BUT COASTAL AREAS BY MID
TO LATE MORNING.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MCB
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
539 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...LITTLE CHANGE TO THE FORECAST. HAVE USED CURRENT OBS TO
TREND FORECAST INTO THE MID MORNING. HAVE HUNG ON TO THE AREAL
COVERAGE OF STRATUS A COUPLE HOURS LONGER ACROSS THE MIDCOAST AS
WELL.
PREVIOUS DISCUSSION...COASTAL STRATUS HAS ABOUT REACHED ITS WWD
EXTENT ATTM...WHILE IT SLOWLY CREEPS NWD THRU SRN FRANKLIN AND
SOMERSET COUNTIES. WITHIN THE STRATUS...AREAS OF FOG WILL CONTINUE
THRU SUNRISE. VSBYS ARE GENERALLY AOA 1/2SM...SO DON/T FEEL THE
NEED FOR A DENSE FOG ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS GRAY ME
248 AM EDT TUE MAY 7 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH AT LEAST THE FIRST HALF OF
WEDNESDAY AS HIGH PRESSURE REMAINS IN CONTROL. HOWEVER...SOME
COASTAL LOW CLOUDS AND FOG IS EXPECTED AGAIN TONIGHT AND TUESDAY
NIGHT. LOW PRESSURE WILL GRADUALLY WORK UP THE COAST ON WEDNESDAY
ALLOWING US OUR FIRST SHOT OF MEASURABLE RAINFALL WEDNESDAY NIGHT
THROUGH FRIDAY...WITH YET ANOTHER SYSTEM POSSIBLE SATURDAY NIGHT
AND SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
COASTAL STRATUS HAS ABOUT REACHED ITS WWD EXTENT ATTM...WHILE IT
SLOWLY CREEPS NWD THRU SRN FRANKLIN AND SOMERSET COUNTIES. WITHIN
THE STRATUS...AREAS OF FOG WILL CONTINUE THRU SUNRISE. VSBYS ARE
GENERALLY AOA 1/2SM...SO DON/T FEEL THE NEED FOR A DENSE FOG
ADVISORY.
STRATUS WILL SLOWLY ERODE TODAY WITH DIURNAL HEATING...ESPECIALLY
ALONG THE IMMEDIATE COASTLINE. MET GUIDANCE IS AWFULLY BULLISH ON
HIGH TEMPS REACHING THE LOW 70S FOR SRN COASTAL ZONES DESPITE THE
CLOUDY START AND ONSHORE FLOW. FEEL A MORE CONSERVATIVE APPROACH
TO MAX TEMPS ON THE COAST WAS A BETTER BET...WITH THE LOCAL
WRF...BIAS CORRECTED MOS...AND CMC REGIONAL SUGGESTING CLOSER TO
THE MID 60S. ACROSS THE INTERIOR...THE CONTINUED DRY CONDS AND
FULL SUNSHINE TO START WILL RESULT IN QUICK WARMING. TEMPS HERE
WILL LIKELY BE A COUPLE DEGREES ABV GUIDANCE...NEAR 80.
HAVE ALSO UNDERCUT MOS GUIDANCE ON DEW POINTS FOR THE INTERIOR.
EVEN USING RAP VALUES...REPRESENTING THE COOLEST GUIDANCE...RH
VALUES REMAIN AROUND 25% AND WINDS ARE LIGHT ENOUGH THAT NO RED
FLAG CONDS ARE EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
STRATUS WILL LURK JUST OFFSHORE FOR MOST OF THE DAY TODAY...AND
SURGE BACK SWD ALONG THE COAST TONIGHT. EXPECT MAINLY MIDCOAST TO
BE AFFECTED BY LOW CIGS/VSBYS THIS TIME AROUND. INCREASING
MOISTURE WILL KEEP LOW TEMPS FROM BOTTOMING OUT AS COLD AS THE
PAST FEW NIGHTS. WITH LOW STRATUS AND INCREASINGLY MOIST AIR
MASS...HAVE STAYED AWAY FROM BIAS CORRECTED GRIDS GIVEN THE
CHANGING CONDS.
ON WED...UPR LOW WILL MEANDER OUT OF THE MID ATLANTIC. CLOUDS WILL
INCREASE FROM S TO N THRU THE DAY WED. BY LATE IN THE AFTERNOON
EXPECTED SHWRS TO MOVE INTO SRN NH AND ADJACENT ME. PRIOR TO 00Z
THU NOT MUCH IN THE WAY OF QPF SHOULD IMPACT THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE BEST CHANCE FOR SHOWERS WILL BE WEDNESDAY NIGHT AS A SOUTHERLY
GRADIENT ALIGNS THROUGH A DEEP LAYER. MOISTURE AHEAD OF A
WEAKENING ARE OF LOW PRESSURE WILL ENTER FROM THE GULF OF MAINE.
THIS WILL CONTINUE ON THURSDAY...HOWEVER INFLOW WILL NOT BE AS
PROMINENT AS THE TROUGH WEAKENS OVERHEAD.
A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. HOWEVER...WEAK
WAVES OF LOW PRESSURE WILL LIKELY FORM ALONG THE SLOW MOVING
BOUNDARY. AN UPPER LEVEL TROUGH APPROACHING FROM THE NW WILL ALSO
ALLOW THIS SYSTEM TO STALL JUST SOUTH OF OUR FORECAST AREA. THIS
WILL ALLOW FOR A CHANCE OF (WELL NEEDED) SHOWERS RIGHT THROUGH THE
WEEKEND.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LIFR CONDS TO LINGER ON COAST THRU 13 OR
14Z...ERODING FROM S TO N ALONG THE COAST. LOW CLOUDS MAY LINGER
INTO THE MIDDAY INVOF KRKD. VFR CONDS EXPECTED TODAY. IFR/LIFR
CIGS WILL WORK BACK INTO COASTAL AREAS AGAIN TONIGHT...ESPECIALLY
KRKD BUT NOT AS LIKELY AS FAR S AS KPWM. VFR CONDS TO START THE
DAY ON WED...WITH MVFR CIGS/VSBYS IN SHWRS ACROSS SRN NH LATE IN
THE AFTERNOON.
LONG TERM...
EXPECT SHOWERY WEATHER FROM WEDNESDAY NIGHT THROUGH
SATURDAY. CONDITIONS COULD BE MVFR OR IFR DURING THIS PERIOD.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS.
LONG TERM...
SLOW MOVING LOW PRESSURE WILL BRING SHOWERY WEATHER BUT THE
PRESSURE GRADIENT WILL BE TOO LIGHT TO CAUSE GUSTY WINDS THROUGH THIS
WEEKEND. SEAS WILL SLOWLY BUILD DURING THE MIDWEEK PERIOD.
&&
.FIRE WEATHER...
HIGH PRESSURE SLOWLY LOSING ITS GRIP ON THE AREA. NO RAIN IS
EXPECTED TODAY...WITH AFTERNOON RH VALUES DIPPING TO NEAR 25%
AWAY FROM THE COAST. WINDS WILL REMAIN LIGHT ACROSS THE
INTERIOR. THE CHANCE OF WETTING RAINS INCREASES LATER WEDNESDAY
FOR SOUTHERN AREAS...AND BY THURSDAY FOR THE NORTH COUNTRY. RH
VALUES ARE EXPECTED TO CLIMB FURTHER WEDNESDAY...AS AIR MASS
GRADUALLY MOISTENS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
946 PM EDT WED MAY 8 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL SLOWLY LIFT NORTHEAST ACROSS THE MID
ATLANTIC REGION TONIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE
SYSTEM FOR LATER THURSDAY INTO EARLY FRIDAY. THE NEXT SYSTEM WILL
AFFECT THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
LATEST WATER VAPOR IMAGERY DEPICTS UPPER LOW OVER NW VIRGINIA...AS
SHORTWAVE ENERGY IS VISIBLE ROTATING AROUND THE UPPER LOW. AT
THE SFC...LOW PRESSURE HAS LOCATED OVER NRN WV/SE PA. LATEST RADAR
RETURNS SHOW SHOWERS PUSHING THROUGH THE REGION...MOSTLY ALONG AND
EAST OF INTERSTATE 95. ADDITIONAL SHORTWAVE ENERGY WILL ROTATE
AROUND THE SRN PERIPHERY OF THE UPPER LOW TONIGHT...HELPING TO
ENHANCE SHOWERS OVER THE ERN FA. THIS IS ALSO VISIBLE WITH COOLING
CLOUD TOPS ALONG THE INTERSTATE 95/81 CORRIDOR SOUTH OF
PETERSBURG. RUC OMEGA FIELDS MATCH UP WELL WITH CURRENT RADAR...SO
TRENDED FORECAST TOWARD LATEST RUC GUIDANCE. WILL KEEP
LIKELY/CATEGORICAL POPS EAST OF INTERSTATE 95 THROUGH
MIDNIGHT...THEN TAPERING OFF TOWARD THE COAST THROUGH EARLY THURS
MORNING. LIMITED INSTABILITY MAY BE ABLE TO PROVIDE A FEW STRIKES
OF LIGHTNING.
CLEARING SKIES OBSERVED OVER THE NW FA IN NW FLOW. SKIES WILL
GENERALLY CLEAR FROM NW TO SE OVER THE PIEDMONT INTO CNTRL VA
THROUGH THURS MORNING. COMBINATION OF CLEARING SKIES...LIGHT WINDS
AND A MOIST BL WILL RESULT IN AREAS OF FOG/LOCALLY DENSE FOG
OVERNIGHT OVER THE PIEDMONT INTO CNTRL VA. BUMPED TEMPS DOWN A DEG
OR TWO OVERNIGHT OVER THE PIEDMONT INTO CNTRL VA TO ACCOUNT FOR
CLEARING SKIES. LOWS GENERALLY IN THE LOW/MID 50S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
UPPER LOW SHOULD FINALLY EXIT OUR FA TO THE NE BY 12Z
THURSDAY...WITH SHORTWAVE RIDGING TAKING ITS PLACE...BUILDING INTO
THE REGION FROM THE OH/TN VLYS. LINGERING LOW-LEVEL MOISTURE
THURSDAY IN THE WAKE OF THE UPPER LOW AND PERHAPS ONE LAST SPOKE
OF ENERGY WRAPPING AROUND ITS SW SIDE MAY PRODUCE A FEW LINGERING
SHRAS SO WILL MAINTAIN SOME SLIGHT CHC POPS.
OTHERWISE...SUBSIDENCE BEHIND THE DEPARTING SYSTEM AND INCREASING
DOWNSLOPE COMPONENT SHOULD PORTEND TO DRY WX FOR MOST WITH QUICK
CLEARING THURSDAY EVENING. HIGHS THURSDAY IN THE 70S TO AROUND
80...EXCEPT COOLER MID/UPR 60S AT THE IMMEDIATE COASTLINE.
DRY THURSDAY NIGHT INTO THE FIRST HALF OF FRIDAY AS HIGH PRESSURE
BRIEFLY RETURNS. A LEE TROUGH LOOKS TO DEVELOP ACROSS THE REGION
FRIDAY AFTERNOON...WHICH MAY TOUCH OFF A FEW AFTN SHRAS/TSTMS. HAVE
HELD ON TO 20-30% POPS FOR NOW. LOWS THURSDAY NIGHT IN THE 50S.
WARMER FRIDAY WITH HIGHS IN THE 80S...EXCEPT COOLER 70S AT THE
IMMEDIATE COAST.
A SLOW MOVING COLD FRONT APPROACHES THE LOCAL AREA FROM THE OH/TN
VALLEYS LATE FRIDAY NIGHT...THEN MOVES INTO/THRU OUR FA ON
SATURDAY. SHOWERS AND THUNDERSTORMS ARE A POSSIBILITY SATURDAY AFTN
WITH THE FRONT SO WILL CARRY SOLID CHANCE POPS (40-50%). THREAT OF
SEVERE WX APPEARS LOW AT THIS TIME BUT GIVEN WARM AFTN TEMPS AND
AN INFLUX OF HIGHER DEW PT AIR (IN THE 60S)...CANNOT RULE OUT A
FEW STRONG STORMS. LOWS FRIDAY NIGHT IN THE UPR 50S TO LOW 60S.
HIGHS SATURDAY MAINLY IN THE UPR 70S TO LOW 80S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN GNRL AGREEMENT THAT A CDFRNT CROSSES THE RGN LATE SAT
NITE THEN SLOWS AS IT MOVES OFFSHORE SUNDAY. THIS A BIT QUICKER
THAN PREVIOUS MODELS HAD. KEPT CHC POPS SAT NITE WITH FROPA. QSTN
OF HOW MUCH LINGERING MSTR / TROFINESS REMAINS ACROSS THE RGN SUN
B4 DRYER AIR MOVES IN FROM THE NW. LWRD POPS TO SLGHT CHC SUNDAY
UNDER PT SUNNY SKIES. LOWS SAT NITE M50S-L60S. HIGHS SUN 70-75.
HIGH PRS BUILDS INTO THE RGN FROM THE W ERLY NEXT WEEK. THIS HIGH
ORIGINATED IN CANADA SO EXPCT A DRY AND COOLER PRD. PT TO M SUNNY
DAYS WITH M CLR AND CHILLY NITES. LOWS SUN NITE M40S-L50S. HIGHS
MON 65-70. LOWS MON NITE IN THE 40S XCPT NR 50 SERN BEACHES. RIDGE
AXIS BEGINS TO SHFT SE TUE THEN MOVES INTO THE SERN STATES WED. THIS
RESULTS IN A GRDL WARM UP. HIGHS TUE ARND 70. LOWS TUE NITE 45-50.
HIGHS WED IN THE M-U70S XCPT U60S-L70S ALONG THE COAST.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
DIFFUSE AREA OF LO PRES CENTERED N OF THE AREA WILL SLIDE NEWRD
TNGT WITH SHWRS MOVING THROUGH THE FA. IFR LIKELY RETURNS OVRNGT
AS THE RAIN ENDS...WITH SOME LIFR PSBL AS WELL BUT NOT CONFIDENT
ENUF TO INCLUDE IN THE TAFS ATTM. CONDITIONS IMPROVE THRU THE MRNG
HRS THUR AS MIXING INCREASES. AS FAR AS WINDS...GENRLY 5-10 KT
SHIFTING FROM SOUTH THIS AFTN/EVENG TO WEST BY THUR MRNG. MAINLY
DRY CONDITIONS FOR THU INTO FRI...WITH THE NEXT CHC FOR RAIN LATE
FRI INTO SAT IN ASSOCIATION WITH AN APPROACHING COLD FRNT.
&&
.MARINE...
SEAS STILL HOVERING ARND 5 FT ACROSS THE NRN CSTL WTRS...SO WILL
CONT SCA HEADLINES THIS EVENING BUT DROP SEAS BLO 5 FT B4 SUNRISE.
OTW...UPL LVL LOW PROGGED TO SLOWLY PULL OUT TO THE NE OVR THE NEXT
24-48 HRS. OUTSIDE OF ANY CONVECTION THIS EVENING...XPCT S WNDS TO
REMAIN BLO 15 KT THRU FRIDAY NITE.
NEXT FRNT APPRCHS FROM THE W LATE SAT. INCRG PRS GRDNT AHEAD OF IT
WILL LIKELY INCREASE WNDS TO BTWN 15-20 KTS OVR THE CSTL WTRS. CDFRNT
CROSSES THE AREA SUN MORNING. CAA BEHIND IT NOT ALL THAT STRNG BUT
CUD SEE A BRIEF SURGE DOWN THE BAY SUN MORN. ANTHR STRNGR NRLY SURGE
PSBL MONDAY AHEAD OF HIGH PRS BLDG INTO THE RGN.
&&
.HYDROLOGY...
CONSECUTIVE DAYS OF WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
VIRGINIA AND MARYLAND HAVE CAUSED RISES ON AREA STREAMS AND RIVERS.
RAINFALL AMOUNTS OVER THE LAST TWO DAYS REACHED UPWARDS OF THREE TO
FIVE INCHES OVER CENTRAL VA...ESPECIALLY OVER THE JAMES RIVER
BASIN. MINOR FLOODING IS EXPECTED TONIGHT FOR THE JAMES RIVER AT
CARTERSVILLE AND CITY LOCKS...AND MODERATE FLOODING FOR THE JAMES
RIVER AT RICHMOND WESTHAM. RIVER FLOOD WARNINGS HAVE BEEN ISSUED
FOR THESE LOCATIONS.
&&
.TIDES/COASTAL FLOODING...
TIDES OVR THE NEXT FEW CYCLES PROGGED BTWN 1/2 TO 1 FOOT ABOVE
NORMAL...REMAINING BLO MINOR FLOODING LEVELS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...SAM
SHORT TERM...JDM/MAM
LONG TERM...MPR
AVIATION...MAS/DAP
MARINE...MPR
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
942 PM EDT WED MAY 8 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL SLOWLY LIFT NORTHEAST ACROSS THE MID
ATLANTIC REGION TONIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE
SYSTEM FOR LATER THURSDAY INTO EARLY FRIDAY. THE NEXT SYSTEM WILL
AFFECT THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH 6 AM THURSDAY MORNING/...
LATEST WATER VAPOR IMAGERY DEPICTS UPPER LOW OVER NW VIRGINIA...AS
SHORTWAVE ENERGY IS VISIBLE ROTATING AROUND THE UPPER LOW. AT
THE SFC...LOW PRESSURE HAS LOCATED OVER NRN WV/SE PA. LATEST RADAR
RETURNS SHOW SHOWERS PUSHING THROUGH THE REGION...MOSTLY ALONG AND
EAST OF INTERSTATE 95. ADDITIONAL SHORTWAVE ENERGY WILL ROTATE
AROUND THE SRN PERIPHERY OF THE UPPER LOW TONIGHT...HELPING TO
ENHANCE SHOWERS OVER THE ERN FA. THIS IS ALSO VISIBLE WITH COOLING
CLOUD TOPS ALONG THE INTERSTATE 95/81 CORRIDOR SOUTH OF
PETERSBURG. RUC OMEGA FIELDS MATCH UP WELL WITH CURRENT RADAR...SO
TRENDED FORECAST TOWARD LATEST RUC GUIDANCE. WILL KEEP
LIKELY/CATEGORICAL POPS EAST OF INTERSTATE 95 THROUGH
MIDNIGHT...THEN TAPERING OFF TOWARD THE COAST THROUGH EARLY THURS
MORNING. LIMITED INSTABILITY MAY BE ABLE TO PROVIDE A FEW STRIKES
OF LIGHTNING.
CLEARING SKIES OBSERVED OVER THE NW FA IN NW FLOW. SKIES WILL
GENERALLY CLEAR FROM NW TO SE OVER THE PIEDMONT INTO CNTRL VA
THROUGH THURS MORNING. COMBINATION OF CLEARING SKIES...LIGHT WINDS
AND A MOIST BL WILL RESULT IN AREAS OF FOG/LOCALLY DENSE FOG
OVERNIGHT OVER THE PIEDMONT INTO CNTRL VA. BUMPED TEMPS DOWN A DEG
OR TWO OVERNIGHT OVER THE PIEDMONT INTO CNTRL VA TO ACCOUNT FOR
CLEARING SKIES. LOWS GENERALLY IN THE LOW/MID 50S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
UPPER LOW SHOULD FINALLY EXIT OUR FA TO THE NE BY 12Z
THURSDAY...WITH SHORTWAVE RIDGING TAKING ITS PLACE...BUILDING INTO
THE REGION FROM THE OH/TN VLYS. LINGERING LOW-LEVEL MOISTURE
THURSDAY IN THE WAKE OF THE UPPER LOW AND PERHAPS ONE LAST SPOKE
OF ENERGY WRAPPING AROUND ITS SW SIDE MAY PRODUCE A FEW LINGERING
SHRAS SO WILL MAINTAIN SOME SLIGHT CHC POPS.
OTHERWISE...SUBSIDENCE BEHIND THE DEPARTING SYSTEM AND INCREASING
DOWNSLOPE COMPONENT SHOULD PORTEND TO DRY WX FOR MOST WITH QUICK
CLEARING THURSDAY EVENING. HIGHS THURSDAY IN THE 70S TO AROUND
80...EXCEPT COOLER MID/UPR 60S AT THE IMMEDIATE COASTLINE.
DRY THURSDAY NIGHT INTO THE FIRST HALF OF FRIDAY AS HIGH PRESSURE
BRIEFLY RETURNS. A LEE TROUGH LOOKS TO DEVELOP ACROSS THE REGION
FRIDAY AFTERNOON...WHICH MAY TOUCH OFF A FEW AFTN SHRAS/TSTMS. HAVE
HELD ON TO 20-30% POPS FOR NOW. LOWS THURSDAY NIGHT IN THE 50S.
WARMER FRIDAY WITH HIGHS IN THE 80S...EXCEPT COOLER 70S AT THE
IMMEDIATE COAST.
A SLOW MOVING COLD FRONT APPROACHES THE LOCAL AREA FROM THE OH/TN
VALLEYS LATE FRIDAY NIGHT...THEN MOVES INTO/THRU OUR FA ON
SATURDAY. SHOWERS AND THUNDERSTORMS ARE A POSSIBILITY SATURDAY AFTN
WITH THE FRONT SO WILL CARRY SOLID CHANCE POPS (40-50%). THREAT OF
SEVERE WX APPEARS LOW AT THIS TIME BUT GIVEN WARM AFTN TEMPS AND
AN INFLUX OF HIGHER DEW PT AIR (IN THE 60S)...CANNOT RULE OUT A
FEW STRONG STORMS. LOWS FRIDAY NIGHT IN THE UPR 50S TO LOW 60S.
HIGHS SATURDAY MAINLY IN THE UPR 70S TO LOW 80S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS IN GNRL AGREEMENT THAT A CDFRNT CROSSES THE RGN LATE SAT
NITE THEN SLOWS AS IT MOVES OFFSHORE SUNDAY. THIS A BIT QUICKER
THAN PREVIOUS MODELS HAD. KEPT CHC POPS SAT NITE WITH FROPA. QSTN
OF HOW MUCH LINGERING MSTR / TROFINESS REMAINS ACROSS THE RGN SUN
B4 DRYER AIR MOVES IN FROM THE NW. LWRD POPS TO SLGHT CHC SUNDAY
UNDER PT SUNNY SKIES. LOWS SAT NITE M50S-L60S. HIGHS SUN 70-75.
HIGH PRS BUILDS INTO THE RGN FROM THE W ERLY NEXT WEEK. THIS HIGH
ORIGINATED IN CANADA SO EXPCT A DRY AND COOLER PRD. PT TO M SUNNY
DAYS WITH M CLR AND CHILLY NITES. LOWS SUN NITE M40S-L50S. HIGHS
MON 65-70. LOWS MON NITE IN THE 40S XCPT NR 50 SERN BEACHES. RIDGE
AXIS BEGINS TO SHFT SE TUE THEN MOVES INTO THE SERN STATES WED. THIS
RESULTS IN A GRDL WARM UP. HIGHS TUE ARND 70. LOWS TUE NITE 45-50.
HIGHS WED IN THE M-U70S XCPT U60S-L70S ALONG THE COAST.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
DIFFUSE AREA OF LO PRES CENTERED N OF THE AREA WILL SLIDE NEWRD
TNGT WITH SHWRS MOVING THROUGH THE FA. IFR LIKELY RETURNS OVRNGT
AS THE RAIN ENDS...WITH SOME LIFR PSBL AS WELL BUT NOT CONFIDENT
ENUF TO INCLUDE IN THE TAFS ATTM. CONDITIONS IMPROVE THRU THE MRNG
HRS THUR AS MIXING INCREASES. AS FAR AS WINDS...GENRLY 5-10 KT
SHIFTING FROM SOUTH THIS AFTN/EVENG TO WEST BY THUR MRNG. MAINLY
DRY CONDITIONS FOR THU INTO FRI...WITH THE NEXT CHC FOR RAIN LATE
FRI INTO SAT IN ASSOCIATION WITH AN APPROACHING COLD FRNT.
&&
.MARINE...
SEAS STILL HOVERING ARND 5 FT ACROSS THE NRN CSTL WTRS...SO WILL
CONT SCA HEADLINES THIS EVENING BUT DROP SEAS BLO 5 FT B4 SUNRISE.
OTW...UPL LVL LOW PROGGED TO SLOWLY PULL OUT TO THE NE OVR THE NEXT
24-48 HRS. OUTSIDE OF ANY CONVECTION THIS EVENING...XPCT S WNDS TO
REMAIN BLO 15 KT THRU FRIDAY NITE.
NEXT FRNT APPRCHS FROM THE W LATE SAT. INCRG PRS GRDNT AHEAD OF IT
WILL LIKELY INCREASE WNDS TO BTWN 15-20 KTS OVR THE CSTL WTRS. CDFRNT
CROSSES THE AREA SUN MORNING. CAA BEHIND IT NOT ALL THAT STRNG BUT
CUD SEE A BRIEF SURGE DOWN THE BAY SUN MORN. ANTHR STRNGR NRLY SURGE
PSBL MONDAY AHEAD OF HIGH PRS BLDG INTO THE RGN.
&&
.HYDROLOGY...
CONSECUTIVE DAYS OF WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
VIRGINIA AND MARYLAND HAVE CAUSED RISES ON AREA STREAMS AND RIVERS.
RAINFALL AMOUNTS OVER THE LAST TWO DAYS REACHED UPWARDS OF THREE TO
FIVE INCHES OVER CENTRAL VA...ESPECIALLY OVER THE JAMES RIVER
BASIN. MINOR FLOODING IS EXPECTED THIS EVENING INTO TONIGHT FOR
THE JAMES RIVER AT CARTERSVILLE AND CITY LOCKS...AND MODERATE
FLOODING FOR THE JAMES RIVER AT RICHMOND WESTHAM. RIVER FLOOD
WARNINGS HAVE BEEN ISSUED FOR THESE LOCATIONS.
&&
.TIDES/COASTAL FLOODING...
TIDES OVR THE NEXT FEW CYCLES PROGGED BTWN 1/2 TO 1 FOOT ABOVE
NORMAL...REMAINING BLO MINOR FLOODING LEVELS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ654.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM/SAM
SHORT TERM...JDM/MAM
LONG TERM...MPR
AVIATION...MAS/DAP
MARINE...MPR
HYDROLOGY...
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 PM EDT WED MAY 8 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 408 PM EDT WED MAY 8 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS STILL SHOW BLOCKY FLOW
DOMINATING THE CONUS TO THE S OF PROGRESSIVE BUT GRADUALLY
AMPLIFYING FLOW ACROSS CANADA. IN THE BLOCKY CONUS FLOW...MID LEVEL
LOWS ARE LOCATED OVER THE SOUTHERN ROCKIES...ERN SD AND THE MID
ATLANTIC STATES. TO THE N...FLOW ACROSS CANADA HAS AMPLIFIED SOME IN
THE LAST COUPLE OF DAYS AS TROFFING IS NOSING S THRU MANITOBA/NRN
ONTARIO. MUCH STRONGER AMPLIFICATION WILL FOLLOW THIS WEEKEND AS
SHARP TROFFING DEVELOPS S INTO THE GREAT LAKES. COLD FRONT
ASSOCIATED WITH SHORTWAVE THAT MOVED FROM MANITOBA YESTERDAY TO
QUEBEC TODAY IS JUST NW AND N OF LAKE SUPERIOR. AHEAD OF THE
FRONT...IT HAS BEEN ANOTHER WARM DAY ACROSS UPPER MI. SOME LOCATIONS
ALONG LAKE SUPERIOR HAVE EXPERIENCED A MUCH WARMER DAY TODAY AS LAKE
BREEZE DID NOT DEVELOP AS EARLY AS IN PREVIOUS DAYS...AND IT IS
WEAKER. DESPITE ONSHORE WINDS ALONG LAKE MI...COOLING THERE HAS ONCE
AGAIN BEEN WEAK. INLAND...TEMPS HAVE SOARED THRU THE 70S WITH A FEW
SPOTS REACHING 80F. VERY DRY AIR STILL LINGERS OVER A GOOD PORTION
OF UPPER MI (NOTE THE VERY DRY COLUMN AGAIN SAMPLED BY THE 12Z KGRB
SOUNDING). AS A RESULT...DWPTS HAVE CRASHED DOWN AS LOW AS THE UPPER
20S/LWR 30S ACROSS PORTIONS OF MAINLY CNTRL/ERN UPPER MI. RH IS IN
THE 15-25PCT RANGE AT MOST LOCATIONS. FORTUNATELY...WINDS REMAIN
LIGHT...KEEPING FIRE WX CONCERNS IN CHECK FROM WHERE THEY COULD BE
ON A DAY LIKE THIS. SOME OF THE MID LEVEL MOISTURE NOTED ON PREVIOUS
DAYS SOUNDINGS FROM KINL/KMPX HAS ADVECTED INTO UPPER MI TODAY AND
MADE ITS PRESENCE KNOWN WITH POCKETS OF SCT/BKN MID CLOUDS EARLIER
IN THE DAY. DAYTIME HEATING HAS NOW LED TO VERY HIGH BASED CU
DEVELOPING OVER MUCH OF UPPER MI. A FEW RADAR RETURNS HAVE APPEARED
ON KMQT RADAR IMAGERY OVER WRN UPPER MI...BUT DRY LOW-LEVEL AIR HAS
PROBABLY PREVENTED ANY PCPN OR AT LEAST NOTHING MORE THAN A FEW
SPRINKLES FROM REACHING THE GROUND.
COLD FRONT TO THE N WILL DROP S...PASSING ACROSS UPPER MI
TONIGHT/EARLY THU MORNING. LOW-LEVEL DRY AIR WILL CONTINUE TO BE A
PROBLEM DUE TO LITTLE ADVECTION OF ANY MOISTURE AT THE LOW-LEVELS.
EVEN UPSTREAM...KINL/KMPX SOUNDINGS SHOW THAT LOW-LEVELS THERE HAVE
BEEN DRYING OUT OVER THE LAST DAY OR TWO...BUT THERE IS STILL
SUFFICIENT MOISTURE FOR SCT SHRA AND EVEN A FEW TSRA OVER NRN MN
INTO NW WI THIS AFTN. AS MID LEVEL LOW OVER ERN SD DRIFTS E...IT MAY
HELP PUSH BETTER MOISTURE INTO THE FRONTAL BOUNDARY THAT IS DROPPING
OVER THE AREA. HOWEVER...GIVEN THE LOW-LEVEL WIND FLOW/LACK OF
MOISTURE ADVECTION...PREFER THE GEM/ECMWF/UKMET AND TO SOME DEGREE
THE NAM IDEA OF MAINTAINING THE LOW-LEVEL DRY AIR OVER THE AREA
TONIGHT. AS A RESULT...WILL ONLY INCLUDE SCHC/LOW CHC POPS OVER THE
NW PORTION OF THE FCST AREA.
WITH MID LEVEL LOW OPENING UP/WEAKENING AS IT TRACKS E THU...IT
PROBABLY WON`T BE ABLE TO BRING A GOOD PUSH OF MOISTURE N OF THE
COLD FRONT THAT PASSED THRU THE AREA. HOWEVER...THERE ARE
INDICATIONS THAT MID LEVEL FGEN WILL INCREASE ACROSS THE UPPER
LAKES. WITH COLD FRONT SLIPPING S OF THE FCST AREA IN THE
MORNING...THERE WILL BE A BETTER OPPORTUNITY FOR LOW-LEVELS TO
MOISTEN IN THE COOLER AIR MASS UNDERNEATH THE FGEN FORCING...AND
THIS SHOULD PROVIDE AT LEAST A CHANCE OF SHRA OVER MUCH OF THE AREA
THU. WILL PAINT MAINLY THE WRN FCST AREA FOR BEST CHC OF SHRA AS
THERE ARE HINTS OF LOW-LEVEL DRY AIR STILL LINGERING OVER THE E.
WITH CAA AND MORE CLOUDS...IT WILL BE A COOLER DAY...ESPECIALLY NEAR
LAKE SUPERIOR DUE TO GRADIENT FLOW ACROSS THE LAKE (TEMPS ALONG THE
LAKE WILL PROBABLY ONLY BE IN THE LOW/MID 40S THRU THE DAY). ACROSS
THE SCNTRL AND E...TEMPS MAY STILL REACH THE MID 60S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT WED MAY 8 2013
UPPER FLOW GOES THROUGH A TRANSITION DURING THE LONG TERM PERIOD.
INITIALLY ON THURSDAY NIGHT FLOW IS MORE ZONAL WITH BROAD SHALLOW
TROUGH OVER MOST OF CANADA. LATER FRIDAY TRHOUGH SATURDAY...EXPECT
SHARP AMPLIFICATION AS TROUGH CURRENTLY NORTH OF ALASKA BARRELS
ACROSS CANADIAN PRAIRIES AND ONTARIO. PRIMARY COLD FRONT SWINGS
ACROSS UPPER MICHIGAN FRIDAY NIGHT INTO SATURDAY MORNING WITH
PARENT SFC LOW REACHING CENTRAL QUEBEC BY SUNDAY MORNING. MODELS
HAVE TRENDED FARTHER EAST WITH UPPER LOW CENTER AND QUICKER WITH
FRONTAL PASSAGE. TROUGH ALOFT SLOWLY MOVES INTO EASTERN CANADA ON
MONDAY WITH STRONG RIDGE AND WARM AIR EXPANDING TOWARD CENTRAL
CANADA AND THE PLAINS. TAIL END OF EXTENDED FEATURES WARMING TREND
OVER UPPER LAKES AS RIDGING MOVES FARTHER EAST. MAY SEE BREEZY
CONDITIONS ACCOMPANYING THE WARM UP AS STRONG LOW PRESSURE MOVES
FROM MANITOBA TO NORTHWEST ONTARIO.
SHALLOW COOL AIR SLOWLY FILTERS ACROSS UPR MICHIGAN LATER THURSDAY
AND THURSDAY EVENING. STILL A POTENTIAL OF RAIN THURSDAY EVENING
WITH LINGERING H7-H5 MOISTURE/LIFT DUE TO H7-H6 FRONTOGENESIS. NAM
AND GFS MORE BULLISH ON QPF OVER CWA COMPARED TO ECMWF AND GEM-NH.
THINKING NAM IDEA IS TOO FAR WEST WITH PRECIPITATION BAND...BUT
WILL KEEP SMALL POPS OVER SOUTH AND EAST THROUGH 03Z FRIDAY. REST
OF THURSDAY NIGHT INTO FRIDAY LOOKING QUIET OUT AHEAD OF THE STRONG
COLD FRONT. ONE CONCERN COULD BE STRONGER EAST-NORTHEAST WINDS OVER
EASTERN CWA THURSDAY NIGHT INTO FRIDAY MORNING...ESPECIALLY IF NOT
MUCH RAIN OCCURS THERE AND HUMIDITY RECOVERIES ARE POOR THURSDAY
NIGHT. GRADIENT WINDS DIMINISH THROUGH THE DAY ON FRIDAY...BUT AS
BUBBLE HIGH AT 1025MB BUILDS OVER LK SUPERIOR...NORTH WINDS COULD
STAY GUSTY INTO MID AFTN FROM COPPER HARBOR TO MARQUETTE AND GRAND
MARAIS. VERY DRY CONDITIONS AS H85 DWPNTS ARE DOWN TO AROUND -30C.
GIVEN SUCH DRY AIRMASS...EXPECT MIXED LAYER DWPNTS TO MIX OUT AWAY
FROM IMMEDIATE LK SUPERIOR SHORE AS LOW AS MID-UPPER TEENS IN THE
AFTN. EVEN WITH MUCH COOLER TEMPERATURES...ONLY AS WARM AS THE UPPER
50S INLAND...LOW DWPNTS WILL RESULT IN HUMIDITY VALUES BLO 25 PCT
IN AFTERNOON. BASED ON SOUNDINGS...DRY AIRMASS HANGS ON THROUGH
FRIDAY EVENING OVER ALL CWA.
FOCUS THEN IS ON STRONG COLD FRONTAL PASSAGE BY SATURDAY. 1000-500MB
THICKNESS PACKING FROM ECMWF/GFS/NAM INDICATE FRONTAL PASSAGE AFTER
MIDNIGHT FRIDAY NIGHT OVER FAR WEST CWA AND EARLY SATURDAY AFTERNOON
OVER THE FAR EASTERN CWA. SOUNDINGS SHOW MOISTURE BUILDING DOWN FROM
MID-LEVELS...RESULTING IN ONLY A FEW HOURS OF SATURATION FOR SOME
SHOWERS BEFORE DRYING AND SUBSIDENCE KICK IN BEFORE DAYBREAK OVER
WESTERN CWA AND BY MID MORNING OVER EASTERN CWA. WITH THE INITIAL
BATCH OF SHOWERS...LOOKS LIKE IT REMAINS TOO WARM BLO H9 TO HAVE
SNOW MIX IN WITH THE RAIN. 06Z NAM SHOWED ENOUGH COLD AIR WORKING
IN JUST AS PRECIP ENDED AT ERY FOR SOME SNOW SATURDAY MORNING. 12Z
RUN KEEPS IT ALL LIQUID. UNCERTAIN HOW MUCH MOISTURE IS AROUND ON
SATURDAY...BUT THAT WILL HAVE BEARING ON HOW MUCH PRECIP OCCURS AND
WHETHER THERE WILL BE ANY SNOW OR MIXED RAIN AND SNOW. THINKING THAT
NAM MAY BE OVERDONE WITH EXTENT OF SUBSIDENCE/DRYING OR AT THE LEAST
THE EXTENT/DURATION OF DRYING ON SATURDAY. GFS/ECMWF POINT TO CHANCE
OF MORE DIURNAL/COLD POOL TYPE SHOWERS AS TOTAL TOTALS PUSH 50 AND
WITH INCREASING H85-H7 RH. SHOULD SEE LOTS OF CLOUDS AND WILL GO
WITH LOW CHANCES FOR SHOWERS MOST AREAS. GIVEN ENOUGH MOISTURE AS
GFS/ECMWF INDICATE...WET BULB BLO ZERO THROUGH THE DEPTH OF THE
COLUMN WOULD SUPPORT AT LEAST A MIX OF RAIN AND SNOW OVER THE WEST
HALF. MAX TEMPS IN UPPER 30S TO LOWER 40S AT THE COOLEST WILL NOT
ALLOW FOR ANY APPRECIABLE SNOW ACCUMS THOUGH THERE COULD BE BRIEF
REDUCED VSBY IN THE HEAVIEST SNOW SHOWERS. OTHER ISSUE ON SATURDAY
WILL BE STRONG/GUSTY WINDS. SOUNDINGS INDICATE UNIDIRECTIONAL WNW
30-40 KT MIXED LAYER WINDS. PORTION OF THESE WINDS WILL MIX DOWN IN
GUSTS DUE TO MECHANICAL MIXING AND COLD AIR ADVECTION. EXPECT
STRONGEST WINDS OVER 40 MPH ON THE KEWEENAW PENINSULA...WITH GUSTS
OVER 30 MPH ELSEWHERE.
DRYING TREND TAKES OVER SUNDAY INTO MONDAY AS THE LARGER SCALE
TROUGH DEPARTS THE AREA. STILL COOL FOR SUNDAY WITH SIMILAR
READINGS TO SATURDAY. QUITE CHILLY SUNDAY NIGHT WITH MANY AREAS
FALLING BLO FREEZING WITH PWAT LESS THAN 50 PCT OF NORMAL AS SFC
HIGH PRESSURE RIDGE MOVES ACROSS.
REST OF EXTENDED FEATURES WARMING TREND AS RIDGE OVER PLAINS BUILDS
ACROSS. ELEVATED MOISTURE AND INSTABILITY WITH THE WARM AIR ADVECTION
MAY TRIGGER SCT SHOWERS/TSRA TUESDAY. CHANCES FOR WIDESPREAD PRECIP
SEEM LOW THOUGH AS PRIMARY LARGE SCALE LIFT STAYS OVER ONTARIO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 721 PM EDT WED MAY 8 2013
EXPECT VFR CONDITIONS TONIGHT AT KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN
VERY DRY. LATE TONIGHT INTO THU MORNING...STRENGTHENING CHILLY N/NE
FLOW AND INCREASING POTENTIAL OF -SHRA MAY RESULT IN A LOW
STRATOCU/STRATUS DECK DEVELOPING AT ALL THE SITES WITH MVFR CIGS
DEVELOPING. UPSLOPE COMPONENT AT IWD AND SAW WILL KEEP THE CIGS IN
THROUGH THE END OF THE PERIOD. AT CMX...DRY AIR WILL COME BACK IN
LATE AND CONDITIONS WILL GO BACK TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT WED MAY 8 2013
LIGHT WINDS WILL PERSIST INTO THE EVENING. THEN...FOLLOWING THE
PASSAGE OF A COLD FRONT TONIGHT...NNE WINDS WILL INCREASE UP TO
15-25KT LATE TONIGHT THRU THU NIGHT. THE ARRIVAL OF ANOTHER HIGH
PRES RIDGE WILL THEN CAUSE WINDS TO DIMINISH FRI. A STRONGER COLD
FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT WINDS TO
THE NW AT 20-30KT FOR SAT. GIVEN TIGHT PRES GRADIENT AND STRENGTH OF
CAA...GALE FORCE GUSTS WILL LIKELY OCCUR. WINDS WILL THEN DIMINISH W
TO E SUN AS HIGH PRES RIDGE ARRIVES. WINDS SHOULD BE UNDER 15KT
LATER SUN NIGHT THRU MON.
&&
.HYDROLOGY...
ISSUED AT 408 PM EDT WED MAY 8 2013
WARM TEMPS CONTINUE TO MELT LINGERING SN PACK OVER THE HIER TERRAIN
OF THE W AND NCENTRAL. RUNOFF INTO THE MONTREAL RIVER AND ISOLD
FLOODING ALONG THE WISCONSIN AND MICHIGAN BORDER IN WESTERN GOGEBIC
COUNTY NEAR IRONWOOD PROMPTED EVENING SHIFT ON TUESDAY TO ISSUE
AREAL FLOOD ADVISORY FOR GOGEBIC COUNTY. THIS MATCHES UP WITH FLOOD
ADVISORY OUT FOR IRON COUNTY WISCONSIN ISSUED BY WFO DULUTH. PLAN TO
LET WFO MARQUETTE ADVY EXPIRE AS SCHEDULED AS NO OTHER FLOODING HAS
BEEN REPORTED.
OTHERWISE...MOST AREA STREAMS/RIVERS CONTINUE TO REMAIN STEADY OR
SHOW SLOW DECLINE WITH RECENT DRY WX. WITH MINIMAL PRECIP IN THE
FORECAST IN THE COMING DAYS AND BULK OF SNOW PACK GONE EXCEPT OVER
THE HIGHER TERRAIN OF THE KEWEENAW/NCENTRAL...SUSPECT THESE TRENDS
WILL CONTINUE. RIVER ADVISORIES OR FLOOD WARNINGS CONTINUE FOR THE
TRAP ROCK RIVER AT LAKE LINDEN...THE STURGEON RIVER AT ALSTON AND
CHASSELL...AND THE MICHIGAMME RIVER AT WITCH LAKE AND REPUBLIC. FOR
COMPLETE DETAILS...SEE THE LATEST PRODCUTS FOR THESE RIVER FLOOD
WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...07
MARINE...ROLFSON
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
700 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL BEGIN WEDNESDAY NIGHT WITH A SERIES OF DISTURBANCES
SCATTERED ACROSS THE UNITED STATES. THE MAIN FEATURES INFLUENCING
OUR WEATHER OVER THE NEXT SEVERAL DAYS INCLUDE THE LARGE SCALE 500MB
TROUGH STRETCHED ACROSS MUCH OF CANADA...EXTENDING ACROSS MN/AND IA
AT 00Z THURSDAY...WITH AN ELONGATED SFC TROUGH SET UP FROM AROUND
IMT THROUGH ERY AND NORTHEASTWARD. THE TROUGH WILL CONTINUE TO SINK
SOUTHEAST OF THE CWA OVERNIGHT. THE NON-ECMWF SOLUTIONS CONTINUE TO
HIT THE NEXT SHORTWAVE A BIT HARDER...WITH 0.2-0.4IN OF QPF OVER
MUCH OF THE AREA. WILL CONTINUE THE HIGH CHANCE POPS...WITH A
CAVEAT. IF WE GET LESS PRECIP THAN ANTICIPATED...OR IT ENDS UP BEING
SLOWER...THE DOWNSLOPE AREAS FROM ESCANABA THROUGH MANISTIQUE...AND
EAST COULD BE QUITE A BIT LOWER /CURRENTLY FCST TO BOTTOM OUT 35-45
PERCENT/.
EXPECT THE SLOW MOTION 500MB TROUGH TO BE CENTERED OVER THE LAKE
SUPERIOR AND UPPER MI AT 00Z FRIDAY...WITH COOL HIGH PRESSURE
BUILDING IN AT THE SFC. 25-35KT 900-925MB WINDS ARE EXPECTED
THURSDAY NIGHT. THERE IS A SLIGHT CONCERN FOR FIRE CONCERNS...IF WE
HAVE POOR RH RECOVERIES...AS LOTS OF DRY AIR SLIDES IN FOR FRIDAY.
WENT WITH RH VALUES FALLING TO 25-35PERCENT...BUT WOULD NOT BE
SURPRISED TO SEE LOWER VALUES GIVEN THE VERY DRY AIR WITH MIXED
DEWPOINTS IN THE TEENS OR LOWER CENTRAL.
ZONAL FLOW WILL TAKE HOLD FRIDAY AFTERNOON/EVENING AHEAD OF YET
ANOTHER TROUGH ROTATING AROUND THE NORTHERN CANADIAN LOW. THIS ONE
LOOKS TO BE PARTICULARLY INTERESTING...AS IT INTENSIFIES INTO A
CLOSED LOW OVER EASTERN MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT.
THERE IS SOME UNCERTAINTY TO THE POSITION OF THE 500MB LOW AT 00Z
SUNDAY...WHICH WILL LIKELY BE SOMEWHERE BETWEEN WESTERN UPPER MI TO
CENTRAL ONTARIO. THE 07/00Z ECMWF KEPT THE TREND OF BEING THE
DEEPEST WITH THE LOW...RUSHING COLD AIR IN FROM THE WEST DURING THE
DAY SATURDAY. KEPT A GOOD CHANCE OF MIXED PRECIP IN THE FCST FROM
SATURDAY THROUGH SUNDAY...WITH LITTLE TO NO REAL ACCUMULATION
EXPECTED AS THE BULK OF THE MOISTURE SHOULD BE EAST OF THE CWA BY
THE TIME THE -6 TO -10C AIR FILTERS IN. THE ECMWF REMAINS THE
COOLEST WITH THE SYSTEM.
FARTHER OUT...FEW CHANGES WERE MADE TO OUR MODERATING FCST FOR THE
START OF THE NEXT WORK WEEK...WITH W-SW WINDS AND DRY WX FIGURED
MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 655 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 SITES TONIGHT INTO WED
MORNING WITH DRY HI PRES DOMINATING. APPROACHING COLD FRONT FM SRN
CANADA COULD BRING AN INCREASE IN MID CLOUDS LATE WED AFTERNOON BUT
OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL MONITOR LOCAL RIVER LEVELS...BUT CONTINUE TO SEE FALLING
VALUES ACROSS MUCH OF THE REGION AS THE SNOW PACK FALLS TO NEAR ZERO
WITH OUR SERIES OF ABOVE NORMAL TEMPERATURES.
THE LATEST SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND
8AM HAS IRONWOOD WITH NO SNOW LEFT ON THE GROUND...AND ATLANTIC MINE
WITH 4IN. A FEW POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE
KEWEENAW...AND THE HIGHEST ELEVATIONS OF NORTHERN MARQUETTE COUNTY.
THE TRICKY LINGERING ISSUES AT AT TRRM4 /TRAP ROCK - LAKE LINDEN/
AND BESM4 /BESSEMER - BLACK RIVER/. FOR COMPLETE DETAILS...SEE THE
LATEST RIVER FLOOD WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL BEGIN WEDNESDAY NIGHT WITH A SERIES OF DISTURBANCES
SCATTERED ACROSS THE UNITED STATES. THE MAIN FEATURES INFLUENCING
OUR WEATHER OVER THE NEXT SEVERAL DAYS INCLUDE THE LARGE SCALE 500MB
TROUGH STRETCHED ACROSS MUCH OF CANADA...EXTENDING ACROSS MN/AND IA
AT 00Z THURSDAY...WITH AN ELONGATED SFC TROUGH SET UP FROM AROUND
IMT THROUGH ERY AND NORTHEASTWARD. THE TROUGH WILL CONTINUE TO SINK
SOUTHEAST OF THE CWA OVERNIGHT. THE NON-ECMWF SOLUTIONS CONTINUE TO
HIT THE NEXT SHORTWAVE A BIT HARDER...WITH 0.2-0.4IN OF QPF OVER
MUCH OF THE AREA. WILL CONTINUE THE HIGH CHANCE POPS...WITH A
CAVEAT. IF WE GET LESS PRECIP THAN ANTICIPATED...OR IT ENDS UP BEING
SLOWER...THE DOWNSLOPE AREAS FROM ESCANABA THROUGH MANISTIQUE...AND
EAST COULD BE QUITE A BIT LOWER /CURRENTLY FCST TO BOTTOM OUT 35-45
PERCENT/.
EXPECT THE SLOW MOTION 500MB TROUGH TO BE CENTERED OVER THE LAKE
SUPERIOR AND UPPER MI AT 00Z FRIDAY...WITH COOL HIGH PRESSURE
BUILDING IN AT THE SFC. 25-35KT 900-925MB WINDS ARE EXPECTED
THURSDAY NIGHT. THERE IS A SLIGHT CONCERN FOR FIRE CONCERNS...IF WE
HAVE POOR RH RECOVERIES...AS LOTS OF DRY AIR SLIDES IN FOR FRIDAY.
WENT WITH RH VALUES FALLING TO 25-35PERCENT...BUT WOULD NOT BE
SURPRISED TO SEE LOWER VALUES GIVEN THE VERY DRY AIR WITH MIXED
DEWPOINTS IN THE TEENS OR LOWER CENTRAL.
ZONAL FLOW WILL TAKE HOLD FRIDAY AFTERNOON/EVENING AHEAD OF YET
ANOTHER TROUGH ROTATING AROUND THE NORTHERN CANADIAN LOW. THIS ONE
LOOKS TO BE PARTICULARLY INTERESTING...AS IT INTENSIFIES INTO A
CLOSED LOW OVER EASTERN MANITOBA AND WESTERN ONTARIO FRIDAY NIGHT.
THERE IS SOME UNCERTAINTY TO THE POSITION OF THE 500MB LOW AT 00Z
SUNDAY...WHICH WILL LIKELY BE SOMEWHERE BETWEEN WESTERN UPPER MI TO
CENTRAL ONTARIO. THE 07/00Z ECMWF KEPT THE TREND OF BEING THE
DEEPEST WITH THE LOW...RUSHING COLD AIR IN FROM THE WEST DURING THE
DAY SATURDAY. KEPT A GOOD CHANCE OF MIXED PRECIP IN THE FCST FROM
SATURDAY THROUGH SUNDAY...WITH LITTLE TO NO REAL ACCUMULATION
EXPECTED AS THE BULK OF THE MOISTURE SHOULD BE EAST OF THE CWA BY
THE TIME THE -6 TO -10C AIR FILTERS IN. THE ECMWF REMAINS THE
COOLEST WITH THE SYSTEM.
FARTHER OUT...FEW CHANGES WERE MADE TO OUR MODERATING FCST FOR THE
START OF THE NEXT WORK WEEK...WITH W-SW WINDS AND DRY WX FIGURED
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 426 PM EDT TUE MAY 7 2013
WE WILL MONITOR LOCAL RIVER LEVELS...BUT CONTINUE TO SEE FALLING
VALUES ACROSS MUCH OF THE REGION AS THE SNOW PACK FALLS TO NEAR ZERO
WITH OUR SERIES OF ABOVE NORMAL TEMPERATURES.
THE LATEST SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND
8AM HAS IRONWOOD WITH NO SNOW LEFT ON THE GROUND...AND ATLANTIC MINE
WITH 4IN. A FEW POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE
KEWEENAW...AND THE HIGHEST ELEVATIONS OF NORTHERN MARQUETTE COUNTY.
THE TRICKY LINGERING ISSUES AT AT TRRM4 /TRAP ROCK - LAKE LINDEN/
AND BESM4 /BESSEMER - BLACK RIVER/. FOR COMPLETE DETAILS...SEE THE
LATEST RIVER FLOOD WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 403 PM EDT TUE MAY 7 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW BLOCKY FLOW
ACROSS THE CONUS TO THE S OF PROGRESSIVE FLOW ACROSS CNTRL CANADA. A
NARROW RIDGE EXTENDS FROM SRN BRITISH COLUMBIA/NRN WA E ACROSS THE
UPPER GREAT LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS
WERE LOCATED OVER CA/SRN NV...OVER SD AND OVER THE SE CONUS. WITH
THE UPPER GREAT LAKES STILL UNDER THE RIDGE...IT`S BEEN ANOTHER
PLEASANT EARLY MAY DAY ACROSS UPPER MI AS DEEP VERY DRY COLUMN (NOTE
12Z KGRB/KAPX SOUNDINGS) IS ALLOWING FOR ABUNDANT SUNSHINE. SOME
VERY HIGH BASED CU HAS DEVELOPED OVER THE W WITH A FEW ALONG THE
LAKE BREEZE BOUNDARY OVER THE E. VERY DEEP MIXING HAS INTO THE DRY
AIR ALOFT HAS RESULTED IN DWPTS CRASHING OVER THE LAST FEW HRS. RH
HAS PLUNGED INTO THE 10-20PCT RANGE AT A NUMBER OF LOCATIONS ACROSS
THE CNTRL AND E. LAKE BREEZES HAVE AGAIN DEVELOPED ACROSS THE
BOARD...AND WHILE IT`S CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE
40S JUST LIKE YESTERDAY...THE COOLING IS AGAIN VERY WEAK ALONG MOST
OF THE LAKE MI SHORELINE. INLAND...TEMPS HAVE SOARED WELL INTO THE
70S.
NARROW RIDGE OVER THE UPPER LAKES IS IN THE PROCESS OF BREAKING DOWN
AS MODEST AMPLIFICATION OF THE FLOW IS UNDERWAY ACROSS CNTRL/ERN
CANADA IN ASSOCIATION WITH VIGOROUS SHORTWAVE MOVING ACROSS NRN
MANITOBA TO HUDSON BAY. MUCH STRONGER AMPLIFICATION WILL OCCUR LATER
THIS WEEK AS TROF SHARP TROF DEVELOPS S INTO THE GREAT LAKES. COLD
FRONT ASSOCIATED WITH NRN MANITOBA SHORTWAVE IS CURRENTLY RUNNING
FROM NRN MANITOBA TO MT. WITH FRONT STILL WELL W OF THE AREA THRU
THE NIGHT AND WITH DRY AIR MASS LINGERING...ANOTHER MAINLY CLEAR
NIGHT IS ANTICIPATED. OVERALL...LOW-LEVEL WINDS WILL BE LIGHT
AGAIN...AND THERE IS LITTLE CHANGE IN PRECIPITABLE WATER...
SUGGESTING MIN TEMPS SHOULD BE SIMILAR TO LAST NIGHT. HOWEVER...WITH
AIR MASS CONTINUING TO MODERATE WITH STRONG HEATING THIS AFTN...
WOULD EXPECT MINS GENERALLY TO BE A FEW DEGREES HIGHER THAN LAST
NIGHT. DEVELOPING LIGHT S TO SW FLOW WILL BEGIN TO STIR IN THE
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...SO MINS THERE WILL PROBABLY BE
HIGHEST. MIN TEMPS SHOULD RANGE FROM THE 30S INLAND TO THE LWR 40S
ALONG LAKE SUPERIOR.
ON WED...APPROACHING COLD FRONT SHOULD REACH WRN/NRN LAKE SUPERIOR
LATE IN THE AFTN/EARLY EVE. SOME OF THE MOISTURE NOTED ON TODAYS 12Z
KMPX/KINL SOUNDINGS SHOULD ADVECT E AND NE AHEAD OF THE APPROACHING
COLD FRONT. HOWEVER...WITH LIGHT WINDS AND LITTLE ADVECTION AT THE
LOW-LEVELS...DRIER AIR WILL LIKELY LINGER UNDERNEATH THE MOISTENING
OCCURRING HIGHER UP. IN THE END...THIS WILL WORK TO MINIMIZE SHRA
THREAT WED. HOWEVER...WITH MLCAPE UPWARDS OF A FEW HUNDRED J/KG...
CAN`T RULE OUT A FEW HIGH BASED SHRA OVER THE W WHERE AFTN LAKE
BREEZE WILL HELP TO POOL LOW-LEVEL MOISTURE AND PROVIDE A LOW-LEVEL
FORCING MECHANISM. OTHERWISE...IT WILL BE ANOTHER WARM DAY ON PAR
WITH WHAT IS GOING ON THIS AFTN.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 403 PM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THRU WED...
BUT A COLD FRONT MOVING ACROSS LAKE SUPERIOR LATE WED AFTN AND
EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS PEAKING IN THE
15-25KT RANGE WED NIGHT INTO THU MORNING. HIGH PRESSURE WILL BUILD
BACK OVER THE AREA FOR FRI AND DIMINISH THE WINDS. A STRONGER
COLD FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT
WINDS TO THE NW AT 20-30KTS SAT. THESE STRONGER WINDS WILL CONTINUE
INTO SAT NIGHT BEFORE GRADUALLY DIMINISHING FROM W TO E ON SUN.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
141 PM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 139 PM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS DRY HIGH PRES CONTINUES TO DOMINATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
723 AM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 722 AM EDT TUE MAY 7 2013
EXPECT VFR CONDITIONS AND LIGHT WINDS AT ALL 3 SITES THIS FCST
PERIOD WITH DRY HI PRES DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 AM EDT TUE MAY 7 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM EDT TUE MAY 7 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW W-E ORIENTED UPR
RDG STRETCHING ALONG THE US/CNDN BORDER TO THE N OF CLOSED UPR LOWS
OVER THE SE CONUS AND ANOTHER JUST OFF THE CA COAST. AT THE SFC...
HI PRES IS CENTERED OVER LK SUP...AND WINDS ARE NEAR CALM UNDER
SLACK PRES GRADIENT. WITH VERY DRY AIRMASS SHOWN ON THE 00Z GRB
RAOB...WHERE PWAT WAS ONLY 0.15 INCH OR 27 PCT OF NORMAL...QUIET WX
DOMINATES THE CWA. THERE ARE SOME HI CLDS OVER THE SCENTRAL...BUT
OTRW SKIES ARE CLR.
DRY HI PRES IS FCST TO DOMINATE THE UPR LKS TDAY/TNGT...SO QUIET
WX/MOCLR SKIES SHOULD CONTINUE. MAIN FCST CONCERNS ARE TEMPS/HOW LO
MIN RH WL FALL THIS AFTN. ANY SHALLOW GROUND FOG THAT FORMS OVER THE
INTERIOR W EARLY THIS MRNG WL BURN OFF QUICKLY AFT SUNRISE. WITH H85
TEMPS THIS AFTN IN THE 10-11C RANGE...ABOUT THE SAME OR 1C HIER THAN
YDAY...MAX TEMPS SHOULD BE SIMILAR TO WHAT OCCURRED ON MON. DEEP
MIXING TO H75 ON FCST SDNGS YIELDS HI TEMPS RISING WELL INTO THE 70S
AWAY FM LK MODERATION. ONE DIFFERENCE IS THE H925 FLOW IS FCST TO BE
A BIT STRONGER OUT OF THE S-SE THAN YDAY AND UP TO 10 KTS WITH HI
CENTER SHIFTING SLOWLY TO THE E. AS A RESULT...LK MODERATION OFF LK
SUP SHOULD NOT PENETRATE AS FAR INLAND AS ON MON. ON THE OTHER
HAND...MODERATION OFF LK MI WL BE A BIT MORE AGGRESSIVE. AWAY FM LK
COOLING/ MOISTENING...THE DEEP MIXING WL ALLOW SFC DEWPTS TO FALL TO
ARND 30 THIS AFTN...RESULTING IN MIN RH ARND 20 PCT. SINCE WINDS
SHOULD BE NO HIER THAN ABOUT 10 MPH...NO FIRE WX HEADLINES ARE
NECESSARY.
CONTINUED AIRMASS MODERATION...A SOMEWHAT STRONGER S WIND...AND THE
ARRIVAL OF MOISTER AIR ESPECIALLY OVER THE W...WHERE THE PWAT IS
FCST TO RISE TO NEAR 0.75 INCH BY 12Z WED...WL CONSPIRE TO KEEP MIN
TEMPS TNGT HIER THAN THIS MRNG. THE DIFFERENCE SHOULD BE MOST
PRONOUNCED OVER THE W CLOSER TO THE INCOMING MOISTER AIR.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 418 AM EDT TUE MAY 7 2013
LIMITED CHANGES TO THE GOING FORECAST FROM 24HRS AGO. THE HIGH
PRESSURE RIDGE THAT THE AREA IS CURRENTLY UNDER WILL BEGIN TO
LOOSEN IT/S GRIP ON THE AREA ON WEDNESDAY...BUT NOT BEFORE
PROVIDING ANOTHER ABOVE NORMAL TEMPERATURE DAY FOR MUCH OF UPPER
MICHIGAN. MOST AREAS WILL SEE TEMPERATURES IN THE 70S...BUT LAKE
BREEZES WILL LEAD TO SLIGHTLY COOLER VALUES NEAR THE GREAT LAKES.
MOST MODELS HAVE BACKED OFF ON PRECIPITATION FROM THE DIURNAL CU
OVER THE WESTERN CWA IN THE AFTERNOON...AND THAT SEEMS REASONABLE
BASED OFF THE MOISTURE BEING FOCUSED ABOVE 6-7KFT. WITH THE HIGH
BASED CLOUDS AND THE LINGERING LOW LEVEL DRY AIR...IT MAY BE TOUGH
TO GET PRECIPITATION TO REACH THE SURFACE. IN ADDITION...LOOKING AT
MODEL SOUNDINGS...THE VERY LOW LEVELS ARE TRYING TO OVER MOISTEN
THE SURFACE...WHICH INCREASES THE SFC BASED CAPE TOWARDS 500-750
J/KG. LOOKING AT MLCAPE...THAT DRY AIR CUTS BACK CAPE VALUES TO
50-250 J/KG AND WITH THE OTHER NEGATIVE VALUES...WILL CUT BACK
POPS TO SLIGHTS OVER THE FAR WEST. ALSO FOR WEDNESDAY...LOWERED
DEWPOINTS BASED OFF DRIER AIR HOLDING OVER THE AREA. THIS WILL LEAD
TO ANOTHER DAY OF RH VALUES IN THE 20S OVER THE INTERIOR CENTRAL AND
EAST. FORTUNATELY...THE WINDS WILL AGAIN REMAIN LIGHT AND BE THE
STRONGEST ALONG THE LEADING EDGE OF THE LAKE BREEZES.
FOR WEDNESDAY NIGHT INTO THURSDAY...FOCUS TURNS TO THE WEAK COLD
FRONT DROPPING SOUTHEAST ACROSS THE AREA IN THE EARLY EVENING AND
WEAK SHORTWAVE ENERGY AND ASSOCIATED MOISTURE PUSHING EAST FROM
SOUTHERN MINNESOTA AND INTO THE LOWER GREAT LAKES. WITH THE MOISTURE
FAIRLY LIMITED WITH THE COLD FRONT...THE PRECIPITATION CHANCES WILL
BE LARGELY DEPENDENT ON THE TRACK OF THE SHORTWAVE. WITH THE BEST
MOISTURE AND CLOSEST PROXIMITY TO THE ENERGY TO THE SOUTHWEST OF THE
AREA...WILL HAVE THE HIGHEST POPS OVER THE WEST...WITH LOW END
LIKELY AND HIGH END CHANCE VALUES FOR OVERNIGHT WEDNESDAY NIGHT AND
THURSDAY MORNING BEFORE DIMINISHING DURING THE AFTERNOON. QPF
AMOUNTS SHOULD BE ON THE LIGHT SIDE /LESS THAN A QUARTER OF AN
INCH/ UNLESS THE SHORTWAVE IS FARTHER TO THE NORTH...WHICH ALLOW
FOR GREATER INTERACTION BETWEEN THE WAVE AND THE FRONT.
BEHIND THE COLD FRONT...CANADIAN HIGH PRESSURE WILL BUILD OVER THE
AREA FROM THE NORTHWEST ON THURSDAY NIGHT AND REMAIN INTO FRIDAY
EVENING. THIS SHOULD LEAD TO DRY WEATHER...BUT WITH COOLER
TEMPERATURES ALOFT /850MB TEMPS AROUND 2-4C/ WOULD EXPECT HIGHS TO
BE IN THE 50S INLAND AND IN THE UPPER 40S TO AROUND 50 NEAR LAKE
SUPERIOR WITH THE NORTHEAST WINDS.
STRONG NORTHERN STREAM UPPER TROUGH WILL DIVE SOUTHEAST ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. WITH THE STRENGTH OF THE
FRONT...WOULD EXPECT A NICE LINE OF SHOWERS MOVING ACROSS THE
AREA LATE FRIDAY NIGHT AND SATURDAY. THE SPEED OF THE FRONT WILL
LIMIT ACCUMULATIONS...BUT MOST AREAS SHOULD SEE A TENTH OF AN INCH
OF RAIN. THERE IS THE POTENTIAL THE BACK SIDE OF THIS PRECIPITATION
COULD TURN OVER TO SNOW AND WILL CONTINUE THAT MENTION. WITH THE
VERY COLD AIR ALOFT BEHIND THE FRONT ON SATURDAY AFTERNOON...WOULD
EXPECT DIURNAL SHOWERS TO DEVELOP ON THE BACK SIDE OF THE LOW...DUE
TO THE SFC-700MB LAPSE RATES AROUND 8-8.5 C/KM. THIS PRECIPITATION
WILL START AS SNOW ALOFT AND P-TYPE AT THE SURFACE DEPENDS ON LOW
LEVEL TEMPERATURES. MODELS ARE HINTING AT SURFACE TEMPERATURES BEING
WARMER...BUT WITH THE DRY LOW LEVEL AIR AND INVERTED V LOOK TO THE
SOUNDING...OPTED TO UTILIZE THE WETBULB ZERO HEIGHT FOR RAIN/SNOW
LINE. THIS PLACES A RAIN/SNOW MIX OVER THE NORTH AND RAIN OVER THE
SOUTH. WITH THE LATEST MODEL TRENDS...IT MAY END UP BEING SNOW
ACROSS MUCH OF THE AREA. ALSO ADJUSTED HIGHS DOWN TOWARDS RAW MODEL
DATA...SINCE MOS TREND TOWARDS NORMAL IS BIASING THE COLD TEMPS.
THIS PRODUCES HIGHS IN THE LOW-MID 40S OVER THE NORTHWEST HALF OF
THE CWA AND UPPER 40S OVER THE SOUTHEAST HALF. THE COOLER
TEMPERATURES AND THE GUSTY NORTHWEST WINDS...25-30KTS...IT WILL NOT
FEEL LIKE A MID MAY DAY ACROSS UPPER MICHIGAN. COULD EVEN BE A FEW
LAKE EFFECT SNOW SHOWERS ON SATURDAY NIGHT OVER THE EAST. DECENT
SFC-775MB DELTA-T VALUES...BUT MOISTURE APPEARS LIMITED AT THIS
POINT WITH AN INVERTED V LOOK BELOW THE CLOUD BASE AND WILL ONLY
MENTION SLIGHT CHANCES.
UPPER TROUGH WILL BEGIN TO SHIFT EAST ON SUNDAY AND PULL THE
MOISTURE WITH IT. THUS...EXPECT A DIMINISHING TREND TO THE
PRECIPITATION ON SATURDAY NIGHT AND A DRY SUNDAY. TEMPERATURES WILL
REMAIN ON THE COLD SIDE ON SUNDAY...WITH HIGHS IN THE LOW 40S OVER
THE EAST AND MID 40S OVER THE WEST DUE TO WARMING TEMPERATURES
ALOFT. UPPER RIDGE WILL THEN BUILD OVER THE UPPER GREAT LAKES FOR
MONDAY INTO TUESDAY. MEANWHILE...A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WILL SWEEP A WARM FRONT ACROSS SOUTHERN
ONTARIO ON MONDAY NIGHT...WHICH COULD BRUSH THE CWA. THIS FRONT
WILL ALSO BRING TEMPERATURES BACK TO NORMAL ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE MAY 7 2013
EXPECT LIGHT WINDS AT KIWD/KCMX/KSAW THIS TAF PERIOD WITH DRY HIGH
PRES DOMINATING. SOME FOG WITH MVFR VSBYS MAY DEVELOP AT KIWD AND
KCMX EARLY THIS MORNING. NOT OUT OF THE QUESTION THAT BRIEF IFR COULD
OCCUR AS WELL. OTHERWISE...VFR CONDITIONS WILL DOMINATE THROUGH THE
DAY ON TUE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 AM EDT TUE MAY 7 2013
HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS TODAY AND
WEDNESDAY...BUT A COLD FRONT MOVING THROUGH ON WEDNESDAY AFTERNOON
AND EARLY EVENING WILL LEAD TO INCREASING NORTH-NORTHEAST WINDS
PEAKING IN THE 15-25KT RANGE ON WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD BACK OVER THE AREA FOR FRIDAY AND
DIMINISH THE WINDS. BUT A STRONGER COLD FRONT WILL SLIDE THROUGH
FRIDAY NIGHT AND SHIFT WINDS TO THE NORTHWEST AT 20-30KTS ON
SATURDAY. THESE WINDS WILL CONTINUE INTO SATURDAY NIGHT BEFORE
GRADUALLY DIMINISHING ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 418 AM EDT TUE MAY 7 2013
HYDROLOGY CONCERNS REMAIN FOR TODAY AND WEDNESDAY...BUT THEY
ARE STARTING TO DIMINISH WITH THE DWINDLING SNOW PACK OVER
WESTERN UPPER MICHIGAN. VISIBLE SATELLITE AND MODIS IMAGERY
YESTERDAY STILL SHOWS SNOW REMAINING IN THE HIGHER TERRAIN LOCATIONS
OF THE HURON MOUNTAINS AND THE KEWEENAW PENINSULA. THE LATEST SNOW
DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL HAVE
AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW POCKETS OF
HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW. DID SEE RISES AT SOME
OF THE SITES OVER THE WEST /ESPECIALLY TRRM4 AND BESM4/ WITH THE
WARMER TEMPERATURES YESTERDAY. BUT THE TRAP ROCK RIVER LEVELED OFF
MUCH FASTER OVERNIGHT AND THAT MAY BE A SIGN OF THE LACK OF SNOW
WATER EQUIVALENT LEFT IN THE BASIN. WITH THE SOLID RISE YESTERDAY OF
BESM4 AND DECENT SNOW COVER...WOULD THINK IT WOULD MAKE ANOTHER PUSH
TODAY. AT THIS TIME...AN EDUCATED GUESS WOULD PUT IT BETWEEN 8 AND 9
FEET THIS AFTERNOON/EVENING...WHICH WOULD LIKELY BE THE LAST MAJOR
PUSH.
THE ONGOING FLOODING ON THE MICHIGAMME RIVER AROUND WITCH LAKE WILL
REMAIN A CONCERN FOR THE NEXT COUPLE OF DAYS UNTIL THE SNOW WATER
MAKES IT OUT OF THE HIGHER TERRAIN OF NORTHWEST MARQUETTE COUNTY.
THE STURGEON RIVER AT ALSTON AND CHASSELL CONTINUES TO HOVER BETWEEN
ADVISORY AND WARNING LEVELS AND WOULD EXPECT THAT TO CONTINUE BASED
ON THE STEADY FLOW THROUGH THE STURGEON RIVER AT SIDNAW UPSTREAM.
OTHERWISE...THE REST RIVER LEVELS ARE ON THE DOWNWARD TREND AND
WILL LIKELY CONTINUE THIS WEEK.
FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS AND
ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
127 AM EDT TUE MAY 7 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON MAY 6 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW BLOCKY FLOW ACROSS THE
CONUS TO THE S OF NEARLY ZONAL FLOW ACROSS CNTRL CANADA. A NARROW
RIDGE EXTENDS FROM SRN BRITISH COLUMBIA E ACROSS THE UPPER GREAT
LAKES TO NEW ENGLAND. FARTHER S...CLOSED MID LEVEL LOWS WERE LOCATED
JUST OFF THE CA COAST...OVER SD AND OVER THE SE CONUS. WITH THE
UPPER GREAT LAKES UNDER THE RIDGE...IT`S BEEN A PLEASANT EARLY MAY
DAY ACROSS UPPER MI AS DEEP DRY COLUMN IS ALLOWING FOR ABUNDANT
SUNSHINE. LAKE BREEZES HAVE DEVELOPED ACROSS THE BOARD. WHILE IT`S
CHILLY ALONG LAKE SUPERIOR WITH TEMPS IN THE 40S...SIGNIFICANT
COOLING HAS YET TO OCCUR ALONG MOST OF THE LAKE MI SHORELINE.
INLAND...TEMPS HAVE SOARED THRU THE 60S TO AS HIGH AS THE LOW/MID
70S. LAST BIT OF LINGERING FOG OVER WRN LAKE SUPERIOR BTWN THE
APOSTLE ISLANDS AND UPPER MI HAS JUST ABOUT DISSIPATED AS OF 1930Z.
WITH LITTLE CHANGE IN THE AIR MASS THRU TUE...FCST FOR TONIGHT/TUE
WILL BE SIMILAR TO LAST NIGHT/TODAY. LIGHT/CALM WIND AND CLEAR SKIES
WILL LEAD TO GOOD RADIATIONAL COOLING CONDITIONS TONIGHT. HOWEVER...
PRECIPITABLE WATER DOES RISE SOME COMPARED TO LAST NIGHT OVER THE W
HALF OR SO (UP TOWARD NORMAL FROM 60PCT OF NORMAL LAST NIGHT). ALONG
WITH AIR MASS MODERATION TODAY...MINS TONIGHT SHOULD BE SEVERAL
DEGREES HIGHER THAN LAST NIGHT. COLUMN REMAINS DRIER OVER THE E...SO
MINS THERE WILL PROBABLY BE WITHIN A COUPLE OF DEGREES OF LAST
NIGHTS MINS. OVERALL...EXPECT MIN TEMPS TONIGHT IN THE 30S. MIGHT
SEE SOME PATCHY GROUND FOG OVER THE INTERIOR W LATE TONIGHT. 850MB
TEMPS TUE ARE NEARLY THE SAME AS TODAY. WITH ABUNDANT SUNSHINE AGAIN
(SHOULD BE SOME CU OVER THE W)...MAX TEMPS WILL BE SIMILAR TO WHAT
IS BEING OBSERVED THIS AFTN. SFC HIGH PRES RIDGED ACROSS THE UPPER
LAKES WILL LEAD TO ANOTHER DAY OF LAKE BREEZES. HOWEVER...WITH HIGH
CENTER SETTING UP A LITTLE FARTHER E...LIGHT SOUTHERLY GRADIENT FLOW
SHOULD LEAD TO A LESS AGGRESSIVE INLAND PUSH OF THE LAKE SUPERIOR
LAKE BREEZE...AND COOLING SHOULD BE A LITTLE STRONGER ALONG LAKE MI
SAT AFTN COMPARED TO TODAY. TAKING INTO ACCOUNT MIXING DEPTH...
DWPTS SHOULD TANK IN SOME INLAND AREAS WITH RH BOTTOMING OUT AS LOW
AS AROUND 20PCT. IN GENERAL...RH SHOULD BE IN 20S INLAND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON MAY 6 2013
THE 500MB RIDGE THAT HAS BEEN SET UP ACROSS UPPER MICHIGAN WILL BE
EXITING EASTWARD TUESDAY NIGHT...WITH AN OPEN WAVE/TROUGH EXTENDING
FROM NORTHERN CANADA THROUGH THE DAKOTAS SHIFTING TOWARD MINNESOTA
AND ONTARIO.
WEAK SSW WINDS FLOW WILL SLOWLY BRING BACK INCREASED MOISTURE
THROUGH THE DAY WEDNESDAY...WITH PW VALUES JUMPING AT OR ABOVE 1IN
BY MID AFTERNOON OVER THE WESTERN THIRD OF THE CWA /175 PERCENT OR
NORMAL OR MORE/. THE MAIN RESULT WILL BE INCREASED CLOUD COVER. A
WEAKENING SFC TROUGH WILL SINK FROM NW LAKE SUPERIOR AT DAYBREAK
WEDNESDAY. FCST MODELS ARE VERY CONSISTENT WITH THE TRACK/TIMING OF
THE TROUGH AS OF THE 12Z RUNS. EXPECT THE TROUGH TO PUSH ACROSS
CENTRAL LAKE SUPERIOR BY 18Z...AND THEN SINK ACROSS UPPER MI
WEDNESDAY AFTERNOON...TO JUST S OF THE CWA BY 06Z THURSDAY. A FEW
SHOWERS WILL BE POSSIBLE WEDNESDAY NIGHT THROUGH THURSDAY...WITH
TOTAL QPF AROUND A TENTH OF AN INCH OR LESS.
STRONG HIGH PRESSURE ACROSS MOST OF CENTRAL CANADA WILL SLOWLY SINK
IN BEHIND THE TROUGH...BRINGING WITH IT A RETURN OF DRIER AND COLDER
AIR. 850MB TEMPS ARE ANTICIPATED TO FALL FROM AROUND 9C WEDNESDAY
AFTERNOON TO AROUND 4C BY FRIDAY AFTERNOON.
LOOKING MORE AT THE FIRE FRONT...THE CENTRAL AND EASTERN UPPER
MICHIGAN WILL CONTINUE TO BE THE DRIEST THROUGH AT LEAST FRIDAY
NIGHT.
WINDS MAY BECOME A CONCERN ON SATURDAY...PICKING UP OUT OF A NW
DIRECTION THROUGHOUT THE DAY...BEHIND A STRONGER COLD FRONT WITH A
REINFORCING SHORTWAVE. A 30-35KT LLJ CORE AROUND 800BM THROUGH
MUCH OF THE DAY SATURDAY OVER THE WEST...RESULTING IN 20-25KT GUSTS
SATURDAY THROUGH MUCH OF SUNDAY.
ON A POSITIVE NOTE...A TENTH TO QUARTER OF AN INCH IS OF RAIN IS
FORECAST...AND MUCH COLDER AIR WILL BE SINKING IN. 850MB TEMPS WILL
COOL SIGNIFICANTLY...WITH THE 12Z ECMWF COMING IN WITH -8 TO -10C
READINGS FROM 06-18Z SUNDAY. WITH A DEEPER AND SLOWER SYSTEM
OVERALL...A FEW FLURRIES WILL BE POSSIBLE FROM SATURDAY THROUGH
SUNDAY. THE GOOD NEWS FOR THOSE WHO WOULD RATHER NOT SEE ANOTHER
SNOWFLAKE UNTIL THE FALL...MOST OF THE MOISTURE WILL BE OUT OF THE
AREA BEFORE THE COLD AIR ARRIVES. DO NOT EXPECT ANY TRAVEL CONCERNS
OR PLOWING NEEDED...GIVEN THE STRENGTH OF THE SUN THIS TIME OF
YEAR...AND THE WARM ROADWAYS. GRASSY SURFACES WILL REALLY SEE THE
ONLY CHANCE OF ANY DUSTING OF SNOW.
AFTER A COOL WEEKEND WITH HIGHS IN THE 40S TO AROUND 50...TEMPS WILL
WARM UP AGAIN TO NEAR NORMAL READINGS BY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE MAY 7 2013
EXPECT LIGHT WINDS AT KIWD/KCMX/KSAW THIS TAF PERIOD WITH DRY HIGH
PRES DOMINATING. SOME FOG WITH MVFR VSBYS MAY DEVELOP AT KIWD AND
KCMX EARLY THIS MORNING. NOT OUT OF THE QUESTION THAT BRIEF IFR COULD
OCCUR AS WELL. OTHERWISE...VFR CONDITIONS WILL DOMINATE THROUGH THE
DAY ON TUE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON MAY 6 2013
QUIET WEATHER WILL CONTINUE OVER THE UPPER GREAT LAKES FOR THE NEXT
COUPLE OF DAYS. WITH HIGH PRES RIDGE REMAINING OVER THE AREA...WINDS
WILL LIKELY REMAIN UNDER 15KT THRU WED AFTN. THEN...A COLD FRONT
DROPPING SOUTHEAST ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT WILL
BRING A WIND SHIFT AND STRONGER WINDS INTO THE 15-25KT RANGE FOR A
TIME LATER WED NIGHT INTO THU. WINDS WILL DIMINISH HEADING INTO FRI
AS A HIGH PRES SYSTEM MOVES ACROSS NRN ONTARIO. A STRONG COLD FRONT
PASSING FRI NIGHT/SAT MORNING WILL BRING ANOTHER ROUND OF 15-25KT
WINDS FOR SAT.
&&
.HYDROLOGY...
ISSUED AT 436 PM EDT MON MAY 6 2013
HYDROLOGY CONCERNS CONTINUE...BUT ARE SLOWLY DIMINISHING AT ALL
SITES EXCEPT FOR LAKE LINDEN ON THE TRAP ROCK RIVER WHICH HAS BEEN
SHOWING ITS USUAL DIURNAL INCREASE AS A RESULT OF THE SIGNIFICANT
SNOW PACK STILL MELTING ACROSS THE KEWEENAW PENINSULA. THE LATEST
SNOW DEPTH OBSERVATIONS /FROM EARLIER THIS MORNING AROUND 8AM/ STILL
HAVE AROUND 3IN AT IRONWOOD...AND 7IN AT ATLANTIC MINE. A FEW
POCKETS OF HIGHER AMOUNTS ARE LIKELY ACROSS THE KEWEENAW.
THE ONGOING FLOODING ON THE STURGEON RIVER AT ALSTON AND
CHASSELL...THE MICHIGAMME RIVER AROUND WITCH LAKE...AND THE PAINT
RIVER NEAR CRYSTAL FALLS WILL REMAIN A CONCERN FOR THE NEXT COUPLE
OF DAYS. FOR COMPLETE DETAILS...SEE THE LATEST RIVER FLOOD WARNINGS
AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...KC
MARINE...ROLFSON
HYDROLOGY...KF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1137 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1057 AM CDT TUE MAY 7 2013
SCT DIURNAL CUMULUS CLOUDS WILL DEVELOP OVER THE REGION THIS
AFTN. THERE COULD BE A FEW SHOWERS/STORMS IN THE ST LOUIS METRO
AREA THIS AFTN...BUT WILL LEAVE THE TAFS IN THIS AREA DRY FOR NOW
AS THE BETTER THREAT FOR ANY PRECIPITATION WILL LIKELY BE SE OF
THIS AREA AND CLOSER TO THE PERSISTENT UPPER LEVEL/SFC LOW OVER
THE SERN US. THE CUMULUS CLOUDS SHOULD DISSIPATE EARLY THIS EVNG
DUE TO THE LOSS OF DAYTIME HEATING. WEAK N-NELY SFC WINDS WILL
CONTINUE THIS AFTN...THEN BECOME LIGHT THIS EVNG. WITH LITTLE IF
ANY CLOUD COVER TGT ALONG WITH LIGHT SFC WINDS COULD NOT RULE OUT
SOME LIGHT PATCHY FOG...BUT WILL PROBABLY LEAVE FOG OUT OF THE
TAFS FOR NOW. SFC WINDS WILL BECOME S-SWLY ON WED. THERE MAY BE
FEW-SCT DIURNAL CUMULUS CLOUDS DEVELOPING BY LATE WED MRNG ALONG
WITH MID-HIGH LEVEL CLOUDS ADVECTING EWD INTO THE REGION.
SPECIFICS FOR KSTL...THE MID LEVEL CLOUDS JUST E OF STL SHOULD
CONTINUE TO DISSIPATE THIS AFTN WITH DIURNAL CUMULUS CLOUDS
DEVELOPING BETWEEN 4000-6000 FT IN HEIGHT. COULD NOT RULE OUT
ISOLATED SHOWERS...BUT WILL LEAVE OUT OF THE STL TAF FOR NOW AS
THE BETTER COVERAGE SHOULD BE SE OF STL. THE CUMULUS CLOUDS SHOULD
DISSIPATE EARLY THIS EVNG. MAY HAVE SCT DIURNAL CUMULUS CLOUDS
AGAIN WED AFTN ALONG WITH MID-HIGH LEVEL CLOUDS ADVECTING EWD INTO
THE AREA. WEAK N-NELY SFC WIND WILL CONTINUE THIS AFTN...THEN
BECOME LIGHT THIS EVNG. THIS LIGHT SFC WIND WILL BECOME S-SWLY WED
AFTN...ALBEIT ONLY ABOUT 6 KTS.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 77 58 79 62 / 20 10 20 30
QUINCY 77 54 77 59 / 10 10 30 70
COLUMBIA 77 55 76 59 / 10 10 30 60
JEFFERSON CITY 77 54 77 60 / 10 10 30 50
SALEM 74 54 78 59 / 20 5 10 20
FARMINGTON 74 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
550 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 548 AM CDT TUE MAY 7 2013
VFR CONDITIONS EXPECTED WITH GRADUAL DECREASE IN MID LEVEL CLOUDS.
LIGHT NORTH WIND TO BECOME LIGHT AND VARIABLE TONIGHT.
SPECIFICS FOR KSTL...
VFR CONDITIONS EXPECTED TO CONTINUE.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
348 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(SATURDAY THROUGH MONDAY)
ISSUED AT 347 AM CDT TUE MAY 7 2013
ANOTHER STRONG SHORTWAVE MOVES ACROSS THE U.S. CANADA BORDER FRIDAY
NIGHT INTO SATURDAY WHICH AMPLIFIES THE AFOREMENTIONED MIDWEST
SHORTWAVE AND PUSHES A STRONG COLD FRONT DOWN THROUGH THE PLAINS
INTO THE MID-MISSISSIPPI VALLEY LATE SATURDAY. STILL LOOKS LIKE
THERE COULD BE A CHANCE OF SHOWERS ON SATURDAY AS THE FRONT MOVES
THROUGH...THOUGH MEDIUM RANGE MODELS ARE NOW SHOWING THAT MOST OF
THE PRECIP MAY BE SOUTH OF THE REGION. A 1030MB CANADIAN HIGH
FOLLOWS ON THE HEELS OF THE FRONT. HIGHS SATURDAY LOOK TO BE NEAR
OR JUST BELOW SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S...BUT THE
COLD CANADIAN AIRMASS WILL PUSH TEMPERATURES WELL BELOW NORMAL ON
SUNDAY AND MONDAY. GUIDANCE IS GIVING ME HIGHS IN THE LOW TO MID
60S AND LOWS IN THE UPPER 30S TO MID 40S. HOWEVER...I WOULD NOT BE
SURPRISED IF ACTUAL TEMPERATURES ARE AS MUCH AS 5 TO 10 DEGREES
COLDER THAN GUIDANCE. GFS AND ECMWF ARE FORECASTING 850MB TEMPS
AROUND 0C ON BOTH SUNDAY AND MONDAY WHICH YIELDS MIX-DOWN TEMPS IN
MID TO UPPER 50S! AM NOT GOING QUITE THAT COLD YET...BUT DID TAKE A
FEW DEGREES OFF GUIDANCE TEMPS BOTH SUNDAY AND MONDAY.
CARNEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON MAY 6 2013
MVFR TO IFR RADIATION FOG HAS DEVELOPED ACROSS PARTS OF WRN MO
WHERE SKIES HAVE CLEARED HOWEVER MID AND HIGH CLOUDS SHOULD
PERSIST OVER MOST OF THE TAF SITES TONIGHT WHICH WOULD LIMIT FOG
FORMATION. THE MOST FAVORABLE LOCATIONS FOR LIGHT FOG APPEAR TO BE
KCOU /WHERE SKIES HAVE STARTED TO CLEAR/ AND FAVORED VALLEY
LOCATIONS SUCH AS KSUS WHERE THE WINDS HAVE BEEN CALM FOR SEVERAL
HOURS. OTHER THAN THE POTENTIAL FOR A FEW HOURS OF LIGHT FOG
TONIGHT...VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. NLY TO NELY WINDS WILL BECOME LGT/VAR AROUND 00Z ONCE A SFC
RIDGE AXIS MOVES INTO THE REGION.
SPECIFICS FOR KSTL...PATCHY LIGHT FOG IS POSSIBLE LATE TONIGHT
HOWEVER VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. CONFIDENCE IN FOG AT KSTL REMAINS TOO LOW TO INCLUDE IN THE
TAF ATTM BASED ON EXPECTED CLOUD COVER AND CURRENT T/TD SPREAD.
NLY TO NELY WINDS BECOME LGT/VAR AROUND 00Z ONCE A SFC RIDGE AXIS
MOVES INTO THE REGION.
KANOFSKY
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 AM CDT TUE MAY 7 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 329 AM CDT TUE MAY 7 2013
UPPER LEVEL LOW STILL CENTERED OVER NORTHWEST GEORGIA/NORTHEAST
ALABAMA IS FORECAST TO BEGIN MOVING SLOWLY NORTHEAST TODAY. THIS
SHOULD FINALLY BRING A CLEARING SKY AND WARMER TEMPERATURES TO THE
REGION. THERE IS A PERSISTENT BAND OF MID LEVEL CLOUDS AROUND
10,000FT WHICH JUST DON`T SEEM TO WANT TO GO AWAY. THE NAM SEEMS TO
BE HANDLING THE DECK PRETTY WELL AT THIS TIME...AND IT SLOWLY THINS
OUT THROUGH THE MORNING. THE RUC ON THE OTHER HAND KEEPS THE DECK
AROUND AT LEAST THROUGH EARLY AFTERNOON. AM LEANING TOWARD THE RUC
AT THIS TIME SINCE THIS IS CLOSER TO PERSISTENCE...AND THIS SYSTEM
HAS BEEN NOTHING IF NOT PERSISTENT. CLOUDS SHOULD BE THINNING OUT
DURING THE AFTERNOON...AND STRONG MAY SUNSHINE SHOULD EASILY PROPEL
HIGHS INTO THE MID AND UPPER 70S. THERE MAY BE ENOUGH INSTABILITY
AROUND THIS AFTERNOON FOR POP-UP SHOWERS AND THUNDERSTORMS...SO THE
SLIGHT CHANCE POPS CURRENTLY IN THE FORECAST LOOK TO BE ON TRACK.
MEANWHILE...THE COMPACT LITTLE CUTOFF LOW CURRENTLY OVER SOUTH
DAKOTA WILL START DRIFTING SOUTHEAST IN THE WAKE OF ITS BIG SISTER
OVER THE EASTERN U.S. AS THE SECOND LARGE CUTOFF NOW OVER THE
CALIFORNIA COAST DRIFTS INTO THE INTERMOUNTAIN WEST. MODELS HAVE
BEEN VERY CONSISTENT IN FORECASTING THE LITTLE NORTHERN PLAINS LOW
TO BREAK DOWN THE UPPER LEVEL RIDGING BETWEEN THE TWO LARGER LOWS ON
WEDNESDAY...BRINGING ANOTHER CHANCE FOR AFTERNOON THUNDERSTORMS
PRIMARILY TO CENTRAL MISSOURI. THE LOW OPENS UP INTO A SHORTWAVE
WEDNESDAY NIGHT INTO THURSDAY BRINGING LOW LEVEL BAROCLINICITY INTO
THE MID-MISSISSIPPI VALLEY...AND AN INCREASING LOW LEVEL JET FROM
THE SOUTHEAST PLAINS. THIS LOOKS LIKE ANOTHER PERIOD OF WET WEATHER
FROM WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS THE SHORTWAVE SLOWLY
AMPLIFIES OVER THE MIDWEST AND THE LOW LEVEL JET CONTINUES TO BRING
A PLUME OF MOISTURE UP FROM THE SOUTHWEST. NOT SAYING IT`S GOING TO
BE A TOTAL WASH...BUT A FEW WAVES OF STORMS FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT LOOK PRETTY LIKELY. LOW LEVEL FLOW
TURNS TO THE NORTHWEST ON FRIDAY WHICH SHOULD BEGIN TO SHUT THE
PRECIP OFF FROM NORTH TO SOUTH...BUT NOT BEFORE THERE MAY BE ANOTHER
WAVE OF SHOWERS OR STORMS ALONG AND SOUTH OF THE I-70 CORRIDOR.
TEMPERATURES THROUGH THE PERIOD LOOK TO BE NEAR OR ABOVE NORMAL IN
THE MID 70S TO AROUND 80 WITH LOWS GENERALLY IN THE UPPER 50S AND
LOW 60S.
CARNEY
.LONG TERM...(TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 310 PM CDT MON MAY 6 2013
(TUESDAY AND TUESDAY NIGHT)
SOUTHEASTERN CONUS UPPER LOW WILL FINALLY HAVE LESS INFLUENCE ON OUR
WEATHER WHICH WILL ALLOW SOME WEAK RIDGING TO MOVE ACROSS THE CWA.
GFS SOUNDINGS ARE STILL SHOWING SOME NARROW UNCAPPED MUCAPE OVER THE
SOUTHEASTERN HALF OF THE CWA DURING THE AFTERNOON...SO WILL KEEP
GOING SLIGHT THUNDERSTORMS CHANCES. EXPECT THIS TO BE MAINLY
DIURNALLY DRIVEN...SO KEPT TUESDAY NIGHT DRY. EXPECT MORE SUNSHINE
ON TUESDAY THAN RECENT DAYS...SO AGREEABLE MOS HIGHS IN THE MID 70S
STILL LOOK GOOD.
(WEDNESDAY THROUGH SATURDAY)
RAIN STILL LOOKS TO RETURN TO THE AREA MID/LATE WEEK AS A FRONT
TEMPORARILY STALLS OVER THE MIDWEST THAT WILL INTERACT WITH ONE OR
TWO UPPER LOWS. CONFIDENCE DURING THIS PERIOD HAS LOWERED TODAY AS
GFS IS SHOWING LESS CONTINUITY THAN IN IT DID YESTERDAY. BY LATE
WEDNESDAY...THERE WILL BE AN ELONGATED COLD FRONT THAT WILL EXTEND
FROM THE GREAT LAKES INTO NEBRASKA. THE GFS BRINGS THE UPPER LOW
CURRENTLY OVER SOUTH DAKOTA ACROSS THE MIDWEST ON THURSDAY WHICH
CAUSES A SURFACE LOW TO DEVELOP ALONG THE FRONT THAT SWEEPS IT SOUTH
OF THE CWA BY EARLY FRIDAY. THE ECMWF INSTEAD SHEARS THIS FIRST
UPPER LOW OUT AND CONCENTRATES ON THE MORE PRONOUNCED LOW NOW OFF
THE WEST COAST. IT SLOWLY MOVES THIS LOW ONSHORE AND INTO THE
CENTRAL PLAINS BY THURSDAY NIGHT. ITS SOLUTION WILL KEEP THE
FRONT IN THE CWA THROUGH LATE FRIDAY. WILL STICK WITH THE MORE
CONSISTENT SOLUTION OF THE ECMWF. CHANCE OF SHOWERS/THUNDERSTORMS
WILL BEGIN BY LATE WEDNESDAY AS LOW LEVEL JET TRANSPORTS GULF
MOISTURE NORTH INTO MO/IL. LIKELY POPS STILL LOOK GOOD ON
THURSDAY/FRIDAY WHEN THE SURFACE FRONT WILL BE STALLED UNDER
PERSISTENT MID LEVEL ASCENT. WILL KEEP WITH HIGHS IN THE 70S WITH
LITTLE DIURNAL SWING AS 850MB TEMPS WILL BE AROUND 10C WITH
CLOUDS/RAIN CHANCES.
ECMWF/GFS STILL SHOW THAT A SHARP MID LEVEL TROUGH WILL DIG DOWN
INTO THE MIDWEST OVER THE WEEKEND WHICH WILL DRIVE A SECONDARY COLD
FRONT THROUGH THE AREA ON SATURDAY. BAND OF POST FRONTAL MOISTURE
AND LIFT FROM THE TROUGH WILL BE ENOUGH FOR SCATTERED SHOWERS ON
SATURDAY.
(SUNDAY THROUGH MONDAY)
ECMWF/GFS ARE IN GOOD AGREEMENT THAT WE WILL BE DRY IN THE WAKE OF
THE UPPER TROUGH THAT WILL MOVE FROM THE GREAT LAKES INTO THE
NORTHEASTERN CONUS. COLD AIR ADVECTION WILL CAUSE BELOW NORMAL
TEMPERATURES ON SUNDAY AND SUNDAY NIGHT BEFORE SURFACE WINDS TURN
OUT OF THE SOUTHWEST AS THE SURFACE HIGH MOVES OFF TO THE EAST.
BRITT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CDT MON MAY 6 2013
MVFR TO IFR RADIATION FOG HAS DEVELOPED ACROSS PARTS OF WRN MO
WHERE SKIES HAVE CLEARED HOWEVER MID AND HIGH CLOUDS SHOULD
PERSIST OVER MOST OF THE TAF SITES TONIGHT WHICH WOULD LIMIT FOG
FORMATION. THE MOST FAVORABLE LOCATIONS FOR LIGHT FOG APPEAR TO BE
KCOU /WHERE SKIES HAVE STARTED TO CLEAR/ AND FAVORED VALLEY
LOCATIONS SUCH AS KSUS WHERE THE WINDS HAVE BEEN CALM FOR SEVERAL
HOURS. OTHER THAN THE POTENTIAL FOR A FEW HOURS OF LIGHT FOG
TONIGHT...VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. NLY TO NELY WINDS WILL BECOME LGT/VAR AROUND 00Z ONCE A SFC
RIDGE AXIS MOVES INTO THE REGION.
SPECIFICS FOR KSTL...PATCHY LIGHT FOG IS POSSIBLE LATE TONIGHT
HOWEVER VFR CONDITIONS ARE EXPECTED FOR THE MAJORITY OF THE TAF
PD. CONFIDENCE IN FOG AT KSTL REMAINS TOO LOW TO INCLUDE IN THE
TAF ATTM BASED ON EXPECTED CLOUD COVER AND CURRENT T/TD SPREAD.
NLY TO NELY WINDS BECOME LGT/VAR AROUND 00Z ONCE A SFC RIDGE AXIS
MOVES INTO THE REGION.
KANOFSKY
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 76 58 79 62 / 20 10 20 40
QUINCY 76 54 77 59 / 10 10 30 60
COLUMBIA 76 55 76 59 / 10 10 30 60
JEFFERSON CITY 76 54 77 60 / 10 10 30 60
SALEM 73 54 77 59 / 20 5 10 20
FARMINGTON 73 51 77 59 / 20 10 20 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1055 PM MDT Mon May 6 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Tonight through Wednesday...Fairly benign weather pattern will
continue overnight. An upper ridge remains in place across central
and northern Montana with associated subsidence providing cloud-
free skies and mild temperatures. Circulation from an upper low
offshore of the California coast is spreading moisture and
instability across the inter-mountain region and into extreme
southern and southwest Montana. Models indicate some CAPE is
available over the area but HRRR analysis indicates moisture is
lacking and very few thunderstorms are depicted through the early
evening hours. The upper low begins moving east on Tuesday with
showers and/or thunderstorms becoming a bit more numerous across
the south and southwest during the afternoon. By Wednesday, the
upper ridge gets suppressed to the south and northwest flow aloft
sets up over the area. Enough moisture and instability will be
present for isolated thunderstorms across the area. Temperatures
will remain above seasonal averages. Emanuel
Wednesday Night through Monday...Medium range models continue to
indicate that unsettled weather will remain across the area through
Saturday. An upper level ridge of high pressure from along the
California coast into the Pacific Northwest and an upper level
trough of low pressure over central/eastern Canada will combine to
keep Montana under a moist and cyclonic northwesterly flow aloft.
Weak disturbances in the flow will generally keep a chance of mainly
afternoon and evening showers and thunderstorms over the area.
Moisture being drawn north by an upper level low pressure area
moving across the central Rockies Wednesday night through Thursday
night will enhance this chance of measurable precipitation. However,
the models seem to agree with this forecast cycle that a strong
Canadian cold front will move south through the area on Friday. Have
therefore increased the overall chance for showers/thunderstorms
during this time and introduced breezy northerly winds in the wake
of the front. For Saturday night into Sunday night, models are in
better agreement with moving the upper level ridge will move east
into Montana. Have mostly gone with dry conditions during this time,
with only a slight chance of showers/thunderstorms in the mountains.
As the ridge axis moves east of the area, models are indicating that
a moist southwesterly flow aloft will combine with the passage of a
Pacific cold front to bring a slightly better chance for
showers/thunderstorms into Monday. Temperatures will generally be 5
to 10 degrees warmer than seasonal averages through Saturday, with a
brief cooling back to near normal associated with the cold frontal
passage on Friday. As the ridge builds into the area, temperatures
will reach 10 to 15 degrees above normal for the latter portion of
the weekend, but they will then cool about 5 to 10 degrees again on
Monday with the passage of the second cold front. Coulston
&&
.AVIATION...
UPDATED 0455Z.
VFR conditions expected across the region through 18Z Tuesday. High
pressure will keep skies mostly clear and winds relatively light
through tonight. Isolated showers over far Southwest Montana will
diminish after sunset but weak instability will result in isolated
showers and a few thunderstorms again Tuesday afternoon. Any
development will likely remain along and south of a KBZN-KBTM line.
Expect a front to move into the region from the northwest after 12z
Tuesday. Winds will turn to the north behind the front with gusts
to around 20 knots. Stronger winds are likely at KCTB during the
frontal passage with gusts up to 40 knots. Scattered low
clouds will develop behind the front. Langlieb
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 46 70 44 72 / 0 10 10 20
CTB 44 63 40 70 / 0 10 10 30
HLN 44 72 45 75 / 0 10 20 20
BZN 38 74 41 74 / 10 20 30 20
WEY 33 64 35 65 / 20 40 40 40
DLN 40 71 42 72 / 10 20 30 30
HVR 43 76 42 72 / 0 0 10 20
LWT 41 72 42 68 / 0 10 10 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
711 PM CDT WED MAY 8 2013
.AVIATION...18Z TAFS FOR KOFK...KLNK AND KOMA.
SHORT TERM AVN CONCERNS ARE ISOLD -TSRA MOVING ACROSS ERN NEB.
EXPECT ISOLD CELLS WILL CONTINUE POPPING UP THE NEXT SEVERAL HOURS
AND MAY WELL MOVE ACROSS THE TAF SITES. THUS HAVE ADDED TEMPO
GROUPS THRU 09/04Z. NEXT ISSUE IS DETERIORATING CONDITIONS LATER
TONIGHT. LATEST OBS SHOWING MID LVL CIGS PRETTY MUCH COVERING ERN
NEB. WITH INFLUX OF LLVL MOISTURE...EXPECT MVFR/IFR CONDITIONS TO
BECOME MORE WIDESPREAD TWD 09/09Z. CONDITIONS IMPROVING AFT 0914Z THEN
WITH VFR CIGS FL050 AGL GENERALLY PREVAILING THE REMAINDER OF THE
FCST PD.
DEE
&&
.PREV DISCUSSION... /ISSUED 258 PM CDT WED MAY 8 2013/
DISCUSSION...
PRECIPITATION CHANCES TONIGHT INTO THURSDAY MAIN FORECAST FOCUS IN
THE SHORTER TERM. EXTENDED FORECAST WILL DEAL WITH A RELATIVELY
BRIEF BUT SUBSTANTIAL COOLDOWN THIS WEEKEND...FOLLOWED BY A MUCH
WARMER PATTERN NEXT WEEK.
AFTERNOON SATELLITE IMAGERY SHOWED A COMPACT UPPER CIRC CENTER
PIVOTING TOWARD NERN NEBR WITH ANOTHER UPPER WAVE MOVG INTO ERN
KS. REMNANT SHOWER ACTIVITY ON A LOBE MOVING AROUND SD UPPER LOW
WAS MOVG TOWARD FAR ERN ZONES AS OF 19Z...WITH SCATTERED
CONVECTION DEVELOPING NEAR THERMAL BOUNDARY BETWEEN PRECIP COOLED
AIR AND LOCATIONS WHICH HAD CLEARED UNDER UPPER THERMAL TROUGH IN
NERN NEBR. WOULD EXPECTED SCATTERED CONVECTION NERN ZONES INTO AT
LEAST EARLY THIS EVENING. ANOTHER AREA WHERE ACTIVITY COULD BE
MORE WIDESPREAD...ESPECIALLY EARLY THIS EVENING...WOULD APPEAR TO
BE NEAR WARM FRONT WHICH HAD LIFTED INTO FAR SRN NEBR. IN FACT
EVEN IF CURRENT ACTIVITY DVLPG NEAR SRN NEBR BOUNDARY DECREASES
EARLY THIS EVENING...WE COULD SEE ADDITIONAL DEVELOPMENT LATE THIS
EVENING AS SUGGESTED BY THE HRRR AND 4KM WRF AS LOW LEVEL JET
STRENGTHENS SOUTH OF BOUNDARY. THE LATTER MODEL EVEN SUGGESTED
NERN NEBR ACTIVITY WOULD BEGIN TURNING SE LATER THIS EVENING
MEETING UP WITH ANY CONVECTION THAT WOULD INCREASE IN SERN NEBR
LATE THIS EVENING. GENERALLY INCREASED POPS MOST AREAS EARLY
TONIGHT AND LATEST TRENDS WILL CONTINUE TO BE MONITORED FOR LAST
MINUTE CHANGES TO 00Z-03Z PD. AS UPPER LOW OVR SD BEGINS OPENING
UP/DROPPING SE LATE TONIGHT...SOME LIGHT SHOWERS COULD MOVE BACK
INTO NERN NEBR TOWARD THU MORNING WITH A CONTINUED SOUTHWARD PUSH
OF THESE GENERALLY LIGHT SHOWERS THURSDAY MORNING. IN
ADDITION...HEATING AND UPPER LOW REMNANTS ON THURSDAY COULD BRING
SCATTERED SHOWERS/TSTMS JUST ABOUT ANYWHERE THURSDAY AFTN AND SOME
POPS WERE ADDED ALL ZONES. GFS/NAM LINGERED QUITE A BIT OF LOW
LEVEL MOISTURE ACROSS MUCH OF THE FORECAST AREA ON THURSDAY WHICH
COULD LIMIT THIS HEATING AND COULD PROVIDE A PSBL NEGATIVE.
FOR NOW FORECAST WAS KEPT DRY THURSDAY NIGHT ALTHOUGH COULD SEE A
LINGERING LIGHT SHOWER/ISOLD TSTM EARLY. CLEARING THEN EXPECTED
FRIDAY WITH RELATIVELY LIGHT WINDS AND SEASONAL OR SLIGHTLY COOLER
TEMPERATURES. A STRONG COLD FRONT STILL ON TRACK TO RACE ACROSS
THE AREA FRIDAY NIGHT WITH GUSTY WINDS AND COOLER READINGS
ON SATURDAY. MAINTAINED SMALL POPS WITH FRONTS PASSAGE NRN ZONES
FRI NIGHT BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ANY CHCS
FARTHER SOUTH. GUSTY NRLY WINDS LIKELY SATURDAY AS SUB-ZERO H85
AIR MOVES INTO NRN ZONES EARLY IN THE DAY BEFORE MODERATING.
AIRMASS IS COOL/DRY ENOUGH SO THAT WITH DECREASING WINDS SAT NIGHT
SEE NO REASON LOWS WON/T GET AT LEAST AS COOL AS LATEST MEX MOST
AREAS. THIS COULD LEAD TO SCATTERED FROST SUNDAY MORNING IF DWPTS
DON/T DRY OUT TOO MUCH. NO FROST WAS MENTIONED AT THIS TIME...BUT
IT IS CERTAINLY POSSIBLE.
WARMING TREND STILL ON TRACK THEN INTO NEXT WEEK WITH TUESDAY
LOOKING EXCEPTIONALLY WARM AHEAD OF COOL FRONT THAT SHOULD KNOCK A
FEW DEGREES OFF OF HIGHS BY DAY 7. A DRY FORECAST WAS MAINTAINED
IN THE EXTENDED UNTIL ALONG AND POST FRONTAL TUE NIGHT/WEDNESDAY.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
711 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 AM EDT TUESDAY...UNSETTLED WEATHER WILL CONTINUE INTO
THE LONG TERM WITH STATIONARY FRONT AFFECTING THE NORTH COUNTRY
GRADUALLY GAINING MOMENTUM EASTWARD ON FRIDAY. RAIN SHOWERS WILL
START THE PERIOD ASSOCIATED WITH THE AFOREMENTIONED STATIONARY
FRONT. LATE FRIDAY INTO EARLY SATURDAY...THE FRONT WILL EXIT EAST
ALONG THE NEW ENGLAND COAST...WITH A BRIEF PERIOD OF SFC RIDGING
BUILDING INTO THE NORTH COUNTRY FRIDAY NIGHT. SATURDAY WILL SEE
THE RIDGING WEAKEN AND SLIDE EAST AS AN UPPER LEVEL CUT OFF LOW
APPROACHES FROM THE NORTHWESTERN GREAT LAKES. AT THE SFC...A
CLOSED LOW ASSOCIATED WITH THE UPPER LOW WILL INTERACT WITH A
WEAKER...SOUTHERN STREAM LOW. DEPENDING HOW FAR NORTH THIS
SOUTHERN LOW MOVES...WILL AFFECT WHEN THE NEXT ROUND OF SHOWERS
ARE EXPECTED ON SATURDAY.
THE UPPER LEVEL CUTOFF LOW WILL MOVE JUST SOUTH OF JAMES BAY
SATURDAY NIGHT...SIGNIFICANTLY DECREASING 500MB HTS AND PRODUCING
SHOWERS OVER PORTIONS OF THE NORTH COUNTRY THROUGH LATE
SUNDAY/SUNDAY NIGHT ASSOCIATED WITH A SFC COLD FRONT. RIDGING
BEHIND THE FRONT WILL BE ACCOMPANIED BY W/NW WINDS AND COOLER
TEMPERATURES. THIS RIDGING MAY BE INTERRUPTED BY A POST FRONTAL
TROUGH BRINGING A LOW CHC FOR SHOWERS ON MONDAY AS THE UPPER LOW
IS SLOW TO EXIT TO THE EAST.
ABOVE NORMAL TEMPERATURES WILL START THE PERIOD WITH MAX TEMPS IN
THE 60S-L70S FRIDAY AND SATURDAY..COOLING BEHIND THE FRONT ON
SUNDAY TO 50S-L60S AND COOLING FURTHER INTO THE M40S-U50S ON
MONDAY. MIN TEMPS WILL SEE A SIMILAR TREND...STARTING IN THE 40S-
L50S THURSDAY NIGHT AND DECREASING TO THE 30S SUNDAY NIGHT.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...VFR CONDITIONS PERSIST WITH HIGH PRESSURE
STRETCHING ACROSS THE NORTH COUNTRY TODAY INTO TONIGHT. EXPECT
MOSTLY CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS DURING
THE DAY AND SUBSIDING AFTER SUNSET.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE FOR THE FIRST HALF OF WEDNESDAY WITH INCREASING CLOUDS
FROM THE SOUTH.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
400 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 400 AM EDT TUESDAY...UNSETTLED WEATHER WILL CONTINUE INTO
THE LONG TERM WITH STATIONARY FRONT AFFECTING THE NORTH COUNTRY
GRADUALLY GAINING MOMENTUM EASTWARD ON FRIDAY. RAIN SHOWERS WILL
START THE PERIOD ASSOCIATED WITH THE AFOREMENTIONED STATIONARY
FRONT. LATE FRIDAY INTO EARLY SATURDAY...THE FRONT WILL EXIT EAST
ALONG THE NEW ENGLAND COAST...WITH A BRIEF PERIOD OF SFC RIDGING
BUILDING INTO THE NORTH COUNTRY FRIDAY NIGHT. SATURDAY WILL SEE
THE RIDGING WEAKEN AND SLIDE EAST AS AN UPPER LEVEL CUT OFF LOW
APPROACHES FROM THE NORTHWESTERN GREAT LAKES. AT THE SFC...A
CLOSED LOW ASSOCIATED WITH THE UPPER LOW WILL INTERACT WITH A
WEAKER...SOUTHERN STREAM LOW. DEPENDING HOW FAR NORTH THIS
SOUTHERN LOW MOVES...WILL AFFECT WHEN THE NEXT ROUND OF SHOWERS
ARE EXPECTED ON SATURDAY.
THE UPPER LEVEL CUTOFF LOW WILL MOVE JUST SOUTH OF JAMES BAY
SATURDAY NIGHT...SIGNIFICANTLY DECREASING 500MB HTS AND PRODUCING
SHOWERS OVER PORTIONS OF THE NORTH COUNTRY THROUGH LATE
SUNDAY/SUNDAY NIGHT ASSOCIATED WITH A SFC COLD FRONT. RIDGING
BEHIND THE FRONT WILL BE ACCOMPANIED BY W/NW WINDS AND COOLER
TEMPERATURES. THIS RIDGING MAY BE INTERRUPTED BY A POST FRONTAL
TROUGH BRINGING A LOW CHC FOR SHOWERS ON MONDAY AS THE UPPER LOW
IS SLOW TO EXIT TO THE EAST.
ABOVE NORMAL TEMPERATURES WILL START THE PERIOD WITH MAX TEMPS IN
THE 60S-L70S FRIDAY AND SATURDAY..COOLING BEHIND THE FRONT ON
SUNDAY TO 50S-L60S AND COOLING FURTHER INTO THE M40S-U50S ON
MONDAY. MIN TEMPS WILL SEE A SIMILAR TREND...STARTING IN THE 40S-
L50S THURSDAY NIGHT AND DECREASING TO THE 30S SUNDAY NIGHT.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE NEXT 24 HOURS. LOCAL EFFECTS WILL DOMINATE WIND
DIRECTION ALONG WITH LLJ OVER THE CPV BLOWING OUT OF THE SOUTH AT
25-35KTS AROUND 2000 FT AND ABV. THIS COULD CREATE SOME
OCCASIONAL GUSTS AT KBTV THROUGH SUNRISE. WITH CONTINUED HIGH
PRESSURE OVERHEAD...FCST SHOULD FOLLOW SIMILAR TREND TO PREVIOUS
24 HOURS.
CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS EXPECTED
TUESDAY...WITH WINDS GENERALLY SUBSIDING AFTER SUNSET.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE TUESDAY NGT AND EARLY WEDNESDAY AS A RIDGE OF HIGH
PRESSURE AT THE SURFACE AND ALOFT REMAINS OVER THE REGION.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
343 AM EDT TUE MAY 7 2013
.SYNOPSIS...
FAIR...DRY AND WARM WEATHER WILL PERSIST TODAY THROUGH MOST OF
WEDNESDAY AS HIGH PRESSURE MAINTAINS CONTROL OVER REGIONAL WEATHER
CONDITIONS. A TREND TOWARD COOLER AND MORE UNSETTLED WEATHER IS
EXPECTED BY THURSDAY ONWARD INTO NEXT WEEKEND AS THE COMBINATION OF
UPPER LEVEL LOW PRESSURE AND A SERIES OF SURFACE FRONTS BRING THE
CHANCE OF WELCOMED RAINFALL TO THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 343 AM EDT TUESDAY...PERSISTENCE FORECAST WILL BE OFFERED
AGAIN TODAY AS IDEAL CHAMBER OF COMMERCE WEATHER PATTERN CONTINUES
UNDER DEEP LAYER BLOCKING HIGH PRESSURE. THUS VERY LITTLE CHANGE
FROM YESTERDAY WITH FULL SUN AND MILD TO WARM TEMPERATURES IN THE
UPPER 70S TO LOWER 80S UNDER LIGHT SURFACE WINDS. DID LEAN TOWARD
DRIEST MODEL TD/RH PROGS FOR OUR AREA THIS AFTERNOON...IN THIS
CASE THE RAW RUC13 VALUES. RECENT PERFORMANCE OF MOS GUIDANCE HAS
BEEN OVERLY MOIST AND FRANKLY QUITE POOR OVER THE PAST FEW
AFTERNOONS...SO SAW NO REASON TO LEAN IN THIS DIRECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 343 AM EDT TUESDAY...CLEAR SKIES AND LIGHT WINDS THEN
CONTINUE TONIGHT INTO THE FIRST HALF OF WEDNESDAY AS BLOCKING
RIDGE FINALLY BEGINS TO BREAK DOWN IN RESPONSE TO A LARGE CYCLONIC
GYRE TRUDGING SLOWLY NORTHEAST FROM THE SOUTHEAST/MID-ATLANTIC
STATES. LOWS TONIGHT GENERALLY FROM 45 TO 55 WITH CUSTOMARY COOLER
SPOTS IN THE DACKS/NERN VT. SFC MOISTURE WILL GRADUALLY INCREASE
OVERNIGHT BUT WIDESPREAD BR/FG NOT EXPECTED GIVEN RECENT DRY
STRETCH AND SFC SOIL MOISTURE VALUES REMAINING QUITE LOW.
BY LATER WEDNESDAY INTO WEDNESDAY NIGHT AFOREMENTIONED UPPER LOW
TRACKS INTO THE NORTHEAST WHILE WEAKENING INTO AN OPEN WAVE. AS
CUSTOMARY WITH SUCH SYSTEMS...HARD TO PINPOINT EXACT TIMING AND
COVERAGE OF SHOWERS...WHICH WILL BE TIED MOST CLOSELY TO BANDS OF
DEEPER MOISTURE AND VORTICITY ADVECTION. NONETHELESS...WITH
INCREASING CYCLONIC FLOW ALOFT AND PWATS CLIMBING NEAR OR SLIGHTLY
ABOVE 1 INCH EXPECT AN INCREASE IN CLOUDS AND SHOWER CHANCES FROM
SOUTH TO NORTH THROUGH THE EVENING AND NIGHTTIME HOURS. COULD ALSO
SEE A STRAY LATE AFTERNOON/EVENING STORM SOUTH AND ALSO OUT IN THE
SLV AS MODELS CONTINUE TO HINT AT SOME WEAK LOW TO MID-LEVEL
INSTABILITY DEVELOPING IN THESE AREAS. HIGHS ON WEDNESDAY RANGING
FROM THE LOWER TO MID 70S SOUTH AS CLOUDS ARRIVE EARLY IN THE
AFTERNOON...TO AROUND 80 ONCE AGAIN NORTH AS SUNSHINE HANGS ON
THROUGH A GOOD PORTION OF THE DAY.
BY THURSDAY DECAYING UPPER LOW PASSES ACROSS OUR REGION WITH
CONTINUED CHANCE OF SHOWERS ALONG WITH AN ISOLATED STORM HERE OR
THERE. BEST COVERAGE TO OCCUR DURING THE AFTERNOON CONVECTIVE
MAXIMUM FROM NOON TO 6 PM OR SO. WITH MORE WIDESPREAD CLOUD COVER
ACROSS THE REGION TEMPERATURES WILL CONTINUE TO EASE BACK SLIGHTLY
...TOPPING OUT GENERALLY IN THE 67 TO 73 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 425 PM EDT MONDAY...UNSETTLED WEATHER EXPECTED THROUGH THE
PERIOD WITH A CHANCE OF RAIN SHOWERS AND COOLER TEMPERATURES.
THE CLOSED UPPER LOW CURRENTLY OVER THE SOUTHEASTERN U.S. WILL BE OVER
EASTERN PENNSYLVANIA EARLY THURSDAY. THIS UPPER LOW WILL MOVE
NORTHEAST INTO THE GULF OF MAINE BY THURSDAY NIGHT. THIS UPPER LOW
WILL BRING A CHANCE OF RAIN SHOWERS TO THE NORTH COUNTRY THURSDAY
AND FRIDAY. A COLD FRONT WILL MOVE SOUTH INTO THE REGION FROM CANADA
ON FRIDAY AND WILL BRING MORE RAIN SHOWERS TO THE REGION FRIDAY
AND FRIDAY NIGHT. A WARM FRONT WILL APPROACH THE REGION ON SATURDAY
BRINGING ANOTHER CHANCE FOR RAIN SHOWERS TO THE NORTH COUNTRY. A
STRONG COLD FRONT WILL MOVE SOUTHEAST FROM CANADA ON SUNDAY AND
WILL BRING MORE RAIN SHOWERS ALONG WITH MUCH COOLER AIR. ON MONDAY...
ECMWF AND GFS MODELS IN GOOD AGREEMENT IN BRINGING A CLOSED UPPER LOW
THROUGH THE REGION ON MONDAY. 500 MB TEMPERATURES BY MONDAY AFTERNOON
WILL BE -30C TO -35C. HIGH TEMPERATURES ON MONDAY WILL ONLY BE IN
THE 50S...WITH SOME 40S OVER THE HIGHER ELEVATIONS OF THE
ADIRONDACKS AND GREEN MOUNTAINS. HAVE GONE WITH A 30 PERCENT
CHANCE OF SHOWERS FOR MONDAY. GIVEN THE STRONG COLD POOL OF AIR
ALOFT AT 500 MB...WOULD NOT BE SURPRISED TO SEE SMALL HAIL MONDAY AFTERNOON
ALONG WITH AN ISOLATED LOW TOP THUNDERSTORM OR TWO. GIVEN THAT
THIS IS 7 DAYS OUT HAVE NOT INCLUDED THIS IN THE GRIDS AT THIS
TIME.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...VFR CONDITIONS WILL PERSIST THROUGH AT
LEAST THE NEXT 24 HOURS. LOCAL EFFECTS WILL DOMINATE WIND
DIRECTION ALONG WITH LLJ OVER THE CPV BLOWING OUT OF THE SOUTH AT
25-35KTS AROUND 2000 FT AND ABV. THIS COULD CREATE SOME
OCCASIONAL GUSTS AT KBTV THROUGH SUNRISE. WITH CONTINUED HIGH
PRESSURE OVERHEAD...FCST SHOULD FOLLOW SIMILAR TREND TO PREVIOUS
24 HOURS.
CLEAR SKIES WITH GENERAL SOUTHERLY FLOW AT 6-12 KTS EXPECTED
TUESDAY...WITH WINDS GENERALLY SUBSIDING AFTER SUNSET.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY THROUGH 18Z WEDNESDAY...VFR CONDITIONS EXPECTED TO
CONTINUE TUESDAY NGT AND EARLY WEDNESDAY AS A RIDGE OF HIGH
PRESSURE AT THE SURFACE AND ALOFT REMAINS OVER THE REGION.
18Z WEDNESDAY ONWARD...INCREASING CLOUDS AS A CLOSED UPPER LOW
OVER THE MID ATLANTIC STATES EARLY WEDNESDAY NIGHT WILL MOVE
NORTHEAST AND BRING A CHANCE OF RAIN SHOWERS TO THE REGION
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...WITH SOME MVFR CONDITIONS
POSSIBLE IN RAIN SHOWERS. A COLD FRONT WILL MOVE INTO THE REGION
ON FRIDAY AND THEN BECOME NEARLY STATIONARY...WITH A CHANCE OF
RAIN SHOWERS FRIDAY AND SATURDAY...WITH SOME AREAS OF MVFR
POSSIBLE.
&&
.FIRE WEATHER...
HIGH PRESSURE OVERHEAD WILL KEEP PRECIPITATION OUT OF THE NORTH
COUNTRY THROUGH MID-DAY ON WEDNESDAY. FULL SUN IS EXPECTED TODAY
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE
15 TO 25 PERCENT RANGE. WINDS WILL GENERALLY BE LIGHT HOWEVER. A
SLOW CLIMB IN HUMIDITY VALUES IS EXPECTED TO START TONIGHT AND
INCREASE THROUGH LATE WEEK ALONG WITH INCREASING CHANCES FOR
WETTING RAINFALL. IN THE MEANTIME HOWEVER...HAVE CONTINUED TO
MENTION THE CONCERNS OF THE VERMONT DEPARTMENT OF FORESTS...PARKS
AND RECREATION REGARDING OPEN BURNING IN SUCH DRY CONDITIONS IN
OUR HAZARDOUS WEATHER OUTLOOK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...WGH
AVIATION...KGM
FIRE WEATHER...BTV
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL STORM SYSTEM WILL BRING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS THROUGH WEDNESDAY. HIGH PRESSURE
BUILDING IN BEHIND THIS SYSTEM THURSDAY AND FRIDAY WILL BRING
WARMER AND DRIER CONDITIONS. SHOWERS MAY RETURN THIS WEEKEND AS
A COLD FRONT MOVES SLOWLY ACROSS THE REGION. A LARGE AREA OF DRY
HIGH PRESSURE EARLY NEXT WEEK WILL BRING A COOLING TREND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 6 PM TUESDAY...SHOWER AND THUNDERSTORM INTENSITY AND
COVERAGE HAS RAPIDLY DECREASED LATE THIS AFTERNOON AND IS NOW
ISOLATED OR BELOW IN COVERAGE. HAVE UPDATED FORECAST ACCORDINGLY.
MOST EVERYWHERE WILL BE DRY OVERNIGHT. PREVIOUS DISCUSSION
FROM THIS AFTERNOON FOLLOWS:
POTENT AND SLOW-MOVING UPPER LOW WILL HELP SPAWN WIDESPREAD
SHOWERS WITH ISOLATED THUNDERSTORMS THIS AFTN. WV IMAGERY
CURRENTLY SHOWS EXPANSIVE...NEARLY STATIONARY...UPPER LOW CENTERED
ACROSS THE UPSTATE OF SC INTO CENTRAL NC. WHILE THIS LOW SPINS AND
MOVES VERY SLOWLY E/NE...A PIECE OF VORT ENERGY WILL MOVE OVERHEAD
THROUGH THIS EVE. THE COMBINATION OF THE VORT IMPULSE...SURFACE
HEATING...AND STEEP ML LAPSE RATES WILL ALLOW FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS THROUGH NIGHTFALL.
KLTX RADAR ATTM HAS A FEW CELLS BEGINNING TO DEVELOP...BUT ACTIVITY
HAS BEEN WEAK AND SPORADIC THUS FAR TODAY. EXAMINATION OF NAM BUFR
SOUNDINGS SUGGESTS A SLIGHTLY WARMER MID-LAYER THAT DEVELOPED WITHIN
CLOUD COVER...WHICH HAS SOMEWHAT SUPPRESSED THE ABILITY FOR SURFACE
PARCELS TO RISE. HRRR/RUC/NAM12 ALL SUGGEST LAPSE RATES STEEPENING
THROUGH THE EVE...WHICH IS SUPPORTED BY THE CLOSER PROXIMITY OF THE
UPPER LOW AS IT DRIFTS NE. 500MB TEMPS OF -22C WILL IMPINGE ON THE
WEST AND NW ZONES...STEEPENING THE 800-500MB LR`S TO AROUND 7C/KM.
THIS PROVIDES THE IMPETUS FOR INCREASING INSTABILITY IN THE FORM OF
SBCAPE TO AROUND 500 J/KG...AND -10C TO -30C CAPE TO 200-300 J/KG.
WITH FREEZING LEVELS ONLY AROUND 7000 FT...ANY STORM (AND EVEN MANY
SHOWERS) WILL HAVE THE CAPABILITY TO PRODUCE SMALL HAIL EVEN FROM
UPDRAFTS NOT USUALLY CONSIDERED VERY ROBUST.
THERE HAS BEEN MUCH TALK INTERNALLY ABOUT THE SIMILARITIES BETWEEN
THIS EVENT AND THAT OF MARCH 25, 2012...WHEN 17 STATEMENTS AND 3
WARNINGS WERE ISSUED FOR HAIL. WHILE THE GENERAL ENVIRONMENT IS
ABOUT THE SAME...SURFACE TEMPS THAT DAY WERE WARMER...WHICH CREATED
STEEPER LOW AND MID-LEVEL LAPSE RATES. STILL...HIGH RES GUIDANCE
SUGGESTS SCATTERED-TO-NUMEROUS SHOWERS/STORMS THIS AFTN...ANY OF
WHICH COULD PRODUCE SMALL HAIL. HAVE CONTINUED TO INDICATE SMALL
HAIL IN WX GRIDS...WITH HIGHEST POP IN THE NW ZONES CLOSEST TO THE
UPPER LOW CENTER.
SO FOR THE REST OF THE DAYLIGHT HOURS...WE WILL SEE INCREASING
COVERAGE OF CONVECTION WITH SMALL HAIL...AND TEMPS FLUCTUATING
WILDLY WITHIN SHOWERS. HIGHS WILL AVERAGE AROUND 70
DEGREES...WARMEST IN THE NORTHERN ZONES.
AFTER NIGHTFALL CLOUD COVER AND CONVECTION WILL WANE WITH LOSS OF
HEATING...AND BY MIDNIGHT THERE SHOULD BE NOTHING LEFT BUT SCT
DEBRIS CLOUDINESS...AND HAVE QUICKLY DROPPED POP TO SILENT AT THAT
TIME. WITH A WEAK PRESSURE GRADIENT AND IMPROVING SKY COVER...DECENT
RADIATIONAL COOLING WILL OCCUR AND HAVE SHOWN MINS IN THE LOW
50S...SLIGHTLY BELOW GUIDANCE. HAVE CONTINUED PATCHY FOG ACROSS THE
AREA AS WELL...AS TD/S WILL RISE TODAY AND SOME MOISTENING WILL
OCCUR FROM THE SHOWERS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...COOL POOL ALOFT ASSOCIATED WITH AN EXPANSIVE
UPPER LOW WILL BE DRIFTING NORTH OVER THE NC/VA BORDER AT DAYBREAK
WEDNESDAY...BUT WILL CONTINUE TO PROVIDE FAVORABLE LAPSE RATES FOR
ISOLATED TO SCATTERED CONVECTION. SEVERAL IMPULSES ALOFT CAUGHT IN
THE WESTERN PERIPHERY OF THIS FEATURE...WILL MOVE EAST ACROSS OUR
FORECAST AREA WEDNESDAY...HELPING TO ENHANCE CONVECTIVE FORMATION.
OVERALL QPF VALUES WILL REMAIN LOW AS THE BULK OF RAIN GENERATION
RESIDES NORTH OF THE AREA.
AS THE UPPER CIRCULATION PULLS INTO SOUTHERN NEW ENGLAND THURSDAY
DRY AIR FROM THE W-NW WILL OVERSPREAD THE FORECAST AREA...AND THIS
SHOULD EFFECTIVELY REMOVE OR GREATLY REDUCE PROBABILITY OF PCPN AND
NO MENTIONABLE POP VALUES ARE PLANNED FOR THURSDAY.
AS THE COOL POOL ALOFT GRADUALLY LOOSENS ITS INFLUENCE OVER THE
FORECAST AREA...AND HEIGHTS REBOUND TO MORE NORMAL LEVELS...WE WILL
SEE A GRADUAL WARMING TREND WED AND THU. MEANWHILE IN PART DUE TO
GOOD RADIATIONAL COOLING AND RESIDUAL COOL AIR OVER THE REGION
INITIALLY...MORNING LOW WILL REMAIN BELOW NORMAL FOR EARLY MAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY
CONSISTENT WITH AN INITIAL SOUTHWESTERLY MID LEVEL PATTERN
TRANSITIONING TO DEEP TROUGHING BY THE END OF THE PERIOD. THIS
DRAMATIC PATTERN CHANGE WILL RESULT IN DRAMATIC CHANGES IN THE
SENSIBLE WEATHER ELEMENTS AS WELL.
FRIDAY REMAINS WARM AND RELATIVELY DRY ALTHOUGH SEA BREEZE
CONVECTION WARRANTS A CONTINUATION OF SLIGHT CHANCE POPS. SATURDAY
AND SUNDAY POPS RISE QUITE A BIT AS THE SLOW MOVING COLD
FRONT...COURTESY OF THE DEVELOPING MID LEVEL TROUGH STARTS MOVING
CLOSER. GUIDANCE HAS SLOWED SLIGHTLY WITH THE FRONT MOVING ACROSS
THE AREA LATE SUNDAY. TIMING APPEARS CONDUCIVE FOR GOOD INSTABILITY
WITH DECENT FORCING FOR POPS ALONG THE COAST AT LEAST AT THIS POINT.
A SECONDARY VORT EMBEDDED IN THE FLOW SLOWS THE PROGRESSION OF THE
FRONT AND WARRANTS AT LEAST SLIGHT CHANCE POPS INTO MONDAY ALONG THE
COAST.
TEMPERATURE TRENDS REMAIN IN PLACE WITH WARM READINGS EARLY TRENDING
DOWN WITH THE INCREASE IN MOISTURE AND FINALLY BELOW NORMAL AT THE
END OF THE PERIOD WITH TEMPERATURES APPROACHING TWO CATEGORIES BELOW
NORMAL.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 PM TUESDAY...LATEST OBS SHOW 3 TO 4 FT SEAS AND SOUTHERLY
WINDS IN THE 15 KT RANGE. NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WEAK PRESSURE GRADIENT IN THE VICINITY OF A DIFFUSE AREA OF LOW
PRESSURE...IS KEEPING LIGHT S/SW WINDS ACROSS THE WATERS TODAY.
ALTHOUGH WIND WAVE CONTRIBUTION IS LIMITED DUE TO THESE LIGHT
WINDS...A COMBINATION OF A 3FT/7SEC SE SWELL...AND 3FT/11SEC EAST
SWELL WILL KEEP SEAS AT 2-4 FT THROUGH THE NEAR TERM PERIOD. WHILE
WIND/WAVE CONDITIONS WILL BE RELAXED...SCATTERED SHOWERS AND
THUNDERSTORMS ARE LIKELY INTO TONIGHT. THESE STORMS COULD IMPACT
ANY MARINE INTERESTS...CREATING BRIEF PERIODS OF HEAVY
RAINFALL...GUSTY WINDS...AND EVEN SOME SMALL HAIL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...MANAGEABLE MARINE CONDITIONS THIS PERIOD WITH
LIGHT TO MODERATE SW WINDS PREVAILING BOTH DAYS...AS LOW PRESSURE
INLAND TRACKS TO THE NORTH AND HIGH PRESSURE REMAINS OFFSHORE.
THE SEA SPECTRUM WILL BE COMPRISED OF A LIGHT TO MODERATE SW CHOP
ACCOMPANIED BY 2-3 FT SE WAVES IN 7-8 SECONDS INTERVALS. A FOOT
OR LESS OF LONG PERIOD E WAVES WILL ALSO BE IN THE MIX WITH WAVE
PERIODS AROUND 11-12 SECONDS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 PM TUESDAY...EXPECT MODEST SOUTHWEST WINDS INITIALLY IN
A RANGE OF 10-15 KNOTS. WITH A FRONT MOVING CLOSER SATURDAY AND
SUNDAY...THE GRADIENT WILL INCREASE TO A HEALTHY 15-20 KNOTS. THE
LATEST MEDIUM RANGE GUIDANCE HAS SLOWED THE PROGRESSION OF THE
FRONT EVER SO SLIGHTLY SO A WIND SHIFT IS NOT IN THE EXTENDED
FORECAST. SIGNIFICANT SEAS WILL FOLLOW THE WIND FIELDS FROM 2-3
FEET INITIALLY TO 2-5 LATER IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...MRR
MARINE...MJC/REK/JDW/SHK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
234 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL STORM SYSTEM WILL BRING A CHANCE OF
SHOWERS AND A FEW THUNDERSTORMS THROUGH WEDNESDAY. HIGH PRESSURE
BUILDING IN BEHIND THIS SYSTEM THURSDAY AND FRIDAY WILL BRING
WARMER AND DRIER CONDITIONS. SHOWERS MAY RETURN THIS WEEKEND AS
A COLD FRONT MOVES SLOWLY ACROSS THE REGION. A LARGE AREA OF DRY
HIGH PRESSURE EARLY NEXT WEEK WILL BRING A COOLING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...POTENT AND SLOW-MOVING UPPER LOW WILL HELP
SPAWN WIDESPREAD SHOWERS WITH ISOLATED THUNDERSTORMS THIS AFTN. WV
IMAGERY CURRENTLY SHOWS EXPANSIVE...NEARLY STATIONARY...UPPER LOW
CENTERED ACROSS THE UPSTATE OF SC INTO CENTRAL NC. WHILE THIS LOW
SPINS AND MOVES VERY SLOWLY E/NE...A PIECE OF VORT ENERGY WILL MOVE
OVERHEAD THROUGH THIS EVE. THE COMBINATION OF THE VORT
IMPULSE...SURFACE HEATING...AND STEEP ML LAPSE RATES WILL ALLOW FOR
THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS THROUGH NIGHTFALL.
KLTX RADAR ATTM HAS A FEW CELLS BEGINNING TO DEVELOP...BUT ACTIVITY
HAS BEEN WEAK AND SPORADIC THUS FAR TODAY. EXAMINATION OF NAM BUFR
SOUNDINGS SUGGESTS A SLIGHTLY WARMER MID-LAYER THAT DEVELOPED WITHIN
CLOUD COVER...WHICH HAS SOMEWHAT SUPPRESSED THE ABILITY FOR SURFACE
PARCELS TO RISE. HRRR/RUC/NAM12 ALL SUGGEST LAPSE RATES STEEPENING
THROUGH THE EVE...WHICH IS SUPPORTED BY THE CLOSER PROXIMITY OF THE
UPPER LOW AS IT DRIFTS NE. 500MB TEMPS OF -22C WILL IMPINGE ON THE
WEST AND NW ZONES...STEEPENING THE 800-500MB LR`S TO AROUND 7C/KM.
THIS PROVIDES THE IMPETUS FOR INCREASING INSTABILITY IN THE FORM OF
SBCAPE TO AROUND 500 J/KG...AND -10C TO -30C CAPE TO 200-300 J/KG.
WITH FREEZING LEVELS ONLY AROUND 7000 FT...ANY STORM (AND EVEN MANY
SHOWERS) WILL HAVE THE CAPABILITY TO PRODUCE SMALL HAIL EVEN FROM
UPDRAFTS NOT USUALLY CONSIDERED VERY ROBUST.
THERE HAS BEEN MUCH TALK INTERNALLY ABOUT THE SIMILARITIES BETWEEN
THIS EVENT AND THAT OF MARCH 25, 2012...WHEN 17 STATEMENTS AND 3
WARNINGS WERE ISSUED FOR HAIL. WHILE THE GENERAL ENVIRONMENT IS
ABOUT THE SAME...SURFACE TEMPS THAT DAY WERE WARMER...WHICH CREATED
STEEPER LOW AND MID-LEVEL LAPSE RATES. STILL...HIGH RES GUIDANCE
SUGGESTS SCATTERED-TO-NUMEROUS SHOWERS/STORMS THIS AFTN...ANY OF
WHICH COULD PRODUCE SMALL HAIL. HAVE CONTINUED TO INDICATE SMALL
HAIL IN WX GRIDS...WITH HIGHEST POP IN THE NW ZONES CLOSEST TO THE
UPPER LOW CENTER.
SO FOR THE REST OF THE DAYLIGHT HOURS...WE WILL SEE INCREASING
COVERAGE OF CONVECTION WITH SMALL HAIL...AND TEMPS FLUCTUATING
WILDLY WITHIN SHOWERS. HIGHS WILL AVERAGE AROUND 70
DEGREES...WARMEST IN THE NORTHERN ZONES.
AFTER NIGHTFALL CLOUD COVER AND CONVECTION WILL WANE WITH LOSS OF
HEATING...AND BY MIDNIGHT THERE SHOULD BE NOTHING LEFT BUT SCT
DEBRIS CLOUDINESS...AND HAVE QUICKLY DROPPED POP TO SILENT AT THAT
TIME. WITH A WEAK PRESSURE GRADIENT AND IMPROVING SKY COVER...DECENT
RADIATIONAL COOLING WILL OCCUR AND HAVE SHOWN MINS IN THE LOW
50S...SLIGHTLY BELOW GUIDANCE. HAVE CONTINUED PATCHY FOG ACROSS THE
AREA AS WELL...AS TD/S WILL RISE TODAY AND SOME MOISTENING WILL
OCCUR FROM THE SHOWERS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...COOL POOL ALOFT ASSOCIATED WITH AN EXPANSIVE
UPPER LOW WILL BE DRIFTING NORTH OVER THE NC/VA BORDER AT DAYBREAK
WEDNESDAY...BUT WILL CONTINUE TO PROVIDE FAVORABLE LAPSE RATES FOR
ISOLATED TO SCATTERED CONVECTION. SEVERAL IMPULSES ALOFT CAUGHT IN
THE WESTERN PERIPHERY OF THIS FEATURE...WILL MOVE EAST ACROSS OUR
FORECAST AREA WEDNESDAY...HELPING TO ENHANCE CONVECTIVE FORMATION.
OVERALL QPF VALUES WILL REMAIN LOW AS THE BULK OF RAIN GENERATION
RESIDES NORTH OF THE AREA.
AS THE UPPER CIRCULATION PULLS INTO SOUTHERN NEW ENGLAND THURSDAY
DRY AIR FROM THE W-NW WILL OVERSPREAD THE FORECAST AREA...AND THIS
SHOULD EFFECTIVELY REMOVE OR GREATLY REDUCE PROBABILITY OF PCPN AND
NO MENTIONABLE POP VALUES ARE PLANNED FOR THURSDAY.
AS THE COOL POOL ALOFT GRADUALLY LOOSENS ITS INFLUENCE OVER THE
FORECAST AREA...AND HEIGHTS REBOUND TO MORE NORMAL LEVELS...WE WILL
SEE A GRADUAL WARMING TREND WED AND THU. MEANWHILE IN PART DUE TO
GOOD RADIATIONAL COOLING AND RESIDUALLY COOL AIR OVER THE REGION
INITIALLY...MORNING LOW WILL REMAIN BELOW NORMAL FOR EARLY MAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...MEDIUM RANGE GUIDANCE REMAINS RELATIVELY
CONSISTENT WITH AN INITIAL SOUTHWESTERLY MID LEVEL PATTERN
TRANSITIONING TO DEEP TROUGHING BY THE END OF THE PERIOD. THIS
DRAMATIC PATTERN CHANGE WILL RESULT IN DRAMATIC CHANGES IN THE
SENSIBLE WEATHER ELEMENTS AS WELL.
FRIDAY REMAINS WARM AND RELATIVELY DRY ALTHOUGH SEA BREEZE
CONVECTION WARRANTS A CONTINUATION OF SLIGHT CHANCE POPS. SATURDAY
AND SUNDAY POPS RISE QUITE A BIT AS THE SLOW MOVING COLD
FRONT...COURTESY OF THE DEVELOPING MID LEVEL TROUGH STARTS MOVING
CLOSER. GUIDANCE HAS SLOWED SLIGHTLY WITH THE FRONT MOVING ACROSS
THE AREA LATE SUNDAY. TIMING APPEARS CONDUCIVE FOR GOOD INSTABILITY
WITH DECENT FORCING FOR POPS ALONG THE COAST AT LEAST AT THIS POINT.
A SECONDARY VORT EMBEDDED IN THE FLOW SLOWS THE PROGRESSION OF THE
FRONT AND WARRANTS AT LEAST SLIGHT CHANCE POPS INTO MONDAY ALONG THE
COAST.
TEMPERATURE TRENDS REMAIN IN PLACE WITH WARM READINGS EARLY TRENDING
DOWN WITH THE INCREASE IN MOISTURE AND FINALLY BELOW NORMAL AT THE
END OF THE PERIOD WITH TEMPERATURES APPROACHING TWO CATEGORIES BELOW
NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM TUESDAY...WEAK PRESSURE GRADIENT IN THE VICINITY OF A
DIFFUSE AREA OF LOW PRESSURE...IS KEEPING LIGHT S/SW WINDS ACROSS
THE WATERS TODAY. ALTHOUGH WIND WAVE CONTRIBUTION IS LIMITED DUE TO
THESE LIGHT WINDS...A COMBINATION OF A 3FT/7SEC SE SWELL...AND
3FT/11SEC EAST SWELL WILL KEEP SEAS AT 2-4 FT THROUGH THE NEAR TERM
PERIOD. WHILE WIND/WAVE CONDITIONS WILL BE RELAXED...SCATTERED
SHOWERS AND THUNDERSTORMS ARE LIKELY INTO TONIGHT. THESE STORMS
COULD IMPACT ANY MARINE INTERESTS...CREATING BRIEF PERIODS OF HEAVY
RAINFALL...GUSTY WINDS...AND EVEN SOME SMALL HAIL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...MANAGEABLE MARINE CONDITIONS THIS PERIOD WITH
LIGHT TO MODERATE SW WINDS PREVAILING BOTH DAYS...AS LOW PRESSURE
INLAND TRACKS TO THE NORTH AND HIGH PRESSURE REMAINS OFFSHORE.
THE SEA SPECTRUM WILL BE COMPRISED OF A LIGHT TO MODERATE SW CHOP
ACCOMPANIED BY 2-3 FT SE WAVES IN 7-8 SECONDS INTERVALS. A FOOT
OR LESS OF LONG PERIOD E WAVES WILL ALSO BE IN THE MIX WITH WAVE
PERIODS AROUND 11-12 SECONDS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 PM TUESDAY...EXPECT MODEST SOUTHWEST WINDS INITIALLY IN
A RANGE OF 10-15 KNOTS. WITH A FRONT MOVING CLOSER SATURDAY AND
SUNDAY...THE GRADIENT WILL INCREASE TO A HEALTHY 15-20 KNOTS. THE
LATEST MEDIUM RANGE GUIDANCE HAS SLOWED THE PROGRESSION OF THE
FRONT EVER SO SLIGHTLY SO A WIND SHIFT IS NOT IN THE EXTENDED
FORECAST. SIGNIFICANT SEAS WILL FOLLOW THE WIND FIELDS FROM 2-3
FEET INITIALLY TO 2-5 LATER IN THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...BJR/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT TUE MAY 7 2013
.SYNOPSIS...
A SLOW MOVING STORM SYSTEM WILL IMPACT THE AREA INTO WEDNESDAY
BRINGING A RISK OF SHOWERS AND SOME THUNDERSTORMS. HAIL IS
POSSIBLE THIS AFTERNOON. WEAK HIGH PRESSURE WILL BUILD IN BEHIND
THIS SYSTEM THURSDAY AND FRIDAY. WARM AND DRY CONDITIONS ARE
EXPECTED LATE WEEK. SHOWERS MAY RETURN DURING THE WEEKEND AHEAD OF
A COLD FRONT. A LARGE AREA OF DRY HIGH PRESSURE EARLY NEXT WEEK
WILL BRING COOLER TEMPERATURES BACK INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM TUESDAY...THE LARGE CUTOFF LOW PRESSURE OVER THE
EASTERN UNITED STATES CONTINUES TO IMPACT THE THE REGIONS WEATHER.
WATER VAPOR IMAGERY SHOWS A SHORT-WAVE TROUGH ROTATING NORTHWARD
ON THE SOUTHEAST PORTION OF THE LOW. THIS LIFTING MECHANISM WITH
VERY COOL TEMPERATURES ALOFT WILL PROVIDE FOR ACTIVE WEATHER LATE
THIS MORNING INTO THE EVENING. THE COOL TEMPERATURES ALOFT ARE
SEEN IN THE CHARLESTON SOUNDING THIS MORNING WITH -19C AT 500 MB
AND 5C AT 850 MB. THE 850MB TEMPERATURE AT CHARLESTON IS 2
STANDARD DEVIATIONS BELOW NORMAL. SO IF THE 400-500 JOULE PER
KILOGRAM CAPE CAN BE ESTABLISHED THEN THERE IS A GOOD CHANCE FOR
SOME SMALL HAIL THIS AFTERNOON.
THE COVERAGE OF CONVECTION THIS MORNING IS FAIRLY WIDESPREAD AND
MOVING NORTHWARD INTO THE WESTERN COUNTIES. THE PREVIOUS FORECAST
OF WIDE SPREAD SHOWERS AND ISOLATED THUNDERSTORMS IS TRENDING IN
THE CORRECT DIRECTION.
...FROM PREVIOUS DISCUSSION
TONIGHT...WITH LOSS OF HEATING...LINGERING CONVECTION SHOULD
SLOWLY COME TO AN END AND WILL DROP POPS BELOW THRESHOLD BY/AROUND
MIDNIGHT. CLOUD COVER SHOULD BECOME MORE PATCHY IN
NATURE...ALLOWING A WIDENING WINDOW OF OPPORTUNITY FOR TEMPS TO
DROP GIVEN THE UNCHARACTERISTICALLY LOW DEW POINTS. PATCHY FOG MAY
DEVELOP TOWARD MORNING. WILL FORECAST LOWS AROUND 50 DEGREES FOR A
LARGE PORTION OF THE AREA WITH LOWER TO MID 50S MORE COMMON ALONG
THE IMMEDIATE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...AS THE CUTOFF UPPER LOW FINALLY GOES
PINWHEELING OFF THE THE NORTH AWAY FROM THE REGION A DRYING TREND
WILL BE UNDERWAY. SLIGHT CHANCE POPS MAINLY FOR NRN AND WRN ZONES AS
A LITTLE WRAP AROUND MOISTURE PAIRED THE STILL RELATIVELY COOL AIR
ALOFT COULD TOUCH OFF ISO CONVECTION. CLOUDS MAY BE SLOW TO DECREASE
DUE TO THE SLOW MOVEMENT OF THE SYSTEM FOR MUCH OF THE DAY BUT DRY
AIR ADVECTION AND DOWNSLOPING BOTH WELL UNDERWAY BY NIGHTTIME. THE
DRYING AND WARM ADVECTION WILL BRING A SUNNY AND SEASONABLE THURSDAY
AFTERNOON WITH LIGHT SW WINDS EVEN THE COOLING SEABREEZE SHOULD NOT
MAKE IT FAR INLAND AND ONLY TEMP TEMPS DOWN A LITTLE ALONG THE
IMMEDIATE COAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...FAIRLY FLAT MID LEVEL FLOW IN PLACE ON FRIDAY
ALTHOUGH SEVERAL WEAK SHORTWAVES WILL BE MOVING THROUGH. ISOLATED
CONVECTION TOUGH TO RULE OUT MAINLY ALONG SEABREEZE. FLOW MAY BECOME
A LITTLE MORE CYCLONIC ON SATURDAY AHEAD OF DEEPENING TROUGH IN THE
GREAT LAKES. PIEDMONT TROUGH/WEAK FRONT ALSO DEVELOPING AND MAY
PROVIDE FOCUS FOR CONVECTIVE INTI. UPPER TROUGH CONTINUES TO DEEPEN
SAT NIGHT INTO SUNDAY AND FRONT BEGINS TO ACCELERATE...MOVING
THROUGH THE COAST EARLY SUNDAY. A PUSH OF COOLER AIR WILL BE ON THE
HEELS OF THIS SYSTEM FOR LATER SUNDAY AND MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...SOME SHOWER ACTIVITY HAS ALREADY MOVED ACROSS THE AREA
THIS MORNING...AND MORE SHOWERS/ISO TSTMS ARE EXPECTED THIS AFTN.
LATEST HRRR RUN SUGGESTS PCPN COVERAGE WILL BE WIDELY SCATTERED THRU
THE AFTERNOON HOURS...SO HAVE INCLUDED PREVAILING VCSH FOR ALL TERMS
WITH TEMPO -SHRA INTO EARLY EVENING. VFR SHOULD PREVAIL WITH SHORT
PERIODS OF MVFR/IFR POSSIBLE IN HEAVIER SHOWERS/TSTMS. TSTMS MAY BE
CAPABLE OF PRODUCING SMALL HAIL WITH THE ABNORMALLY COLD AIR ALOFT.
RAIN CHANCES DIMINISH TONIGHT AND THE WINDS WILL BECOME LIGHT/CALM
DUE TO THE WEAK SFC PRESSURE GRADIENT. DEPENDING ON HOW MUCH CLOUD
COVER LINGERS OVERNIGHT...PATCHY FOG COULD BE AN ISSUE TMRW MORNING.
CONFIDENCE IS LOW ATTM...BUT HAVE INCLUDED MVFR VSBYS FOR OUR
FOG-PRONE TERMINALS.
EXTENDED OUTLOOK...SLIGHT CHANCE OF SHOWERS WEDNESDAY. MORNING FOG
POSSIBLE THURSDAY AND FRIDAY. CHANCE OF SHOWERS SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1020 AM TUESDAY...THE LAND BREEZE STILL IS SEEN ACROSS THE
NEAR SHORE WATERS WITH A WESTERLY WIND. AS THE LAND BREEZE BREAKS
DOWN THE WINDS WILL RETURN TO A MORE SOUTH TO SOUTHWEST FLOW AND
THE WINDS SPEEDS ARE EXPECTED TO REMAIN IN 10 KNOT RANGE WITH SEAS
CONTINUING TO SUBSIDE TO THE 2 TO 3 FEET RANGE BY AFTERNOON.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...A QUIET AND FAIRLY UNCHANGING SET OF CONDITIONS
IN PLACE THROUGH THE PERIOD. WIND TO REMAIN OUT OF THE SW DUE TO THE
NE EXIT AND DISSIPATION OF LOW PRESSURE. ONCE THIS SYSTEM IS OUT OF
THE PICTURE ONLY A WEAK SW GRADIENT ON THE FAR PERIPHERY OF CENTRAL
ATLANTIC HIGH PRESSURE REMAINS. SEAS 2 TO 3 FT ON AVERAGE OVER MOST
ZONES COMPRISED OF SW WIND WAVE AND SE SWELL.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...JUST AS WITH THE SHORT TERM A SOUTHWEST WIND IS
EXPECTED FOR THE DURATION OF THE PERIOD. IN CONTRAST TO THE SHORT
TERM HOWEVER WIND SPEED WILL BE ON THE INCREASE ESPECIALLY DURING
THE SECOND HALF. ON FRIDAY THE HIGH PRESSURE IN THE ATLANTIC WILL
STILL BE VERY DISTANT BUT THE PRESSURE GRADIENT LOCALLY MAY GET A
SMALL BOOST BY A WEAK PIEDMONT TROUGH. THE APPROACH OF A COLD FRONT
ON SATURDAY WILL BRING A MORE PRONOUNCED INCREASE IN WIND
SPEED...ONE THAT WILL BE MORE EFFECTIVE IN BUILDING WAVE
HEIGHTS...POSSIBLY TO WHERE SCEC HEADLINES ARE NEEDED EVEN ONLY IF
LATE IN THE DAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR/JDW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
937 PM CDT WED MAY 8 2013
.UPDATE...
ISSUED AT 937 PM CDT WED MAY 8 2013
THE ONLY SIGNIFICANT CHANGE FOR THE FORECAST FOR TONIGHT INTO
TOMORROW WAS TO REMOVE POPS THROUGH 12 UTC...AND SCALE BACK TO
SLIGHT CHANCE NEAR THE MONTANA BORDER THROUGH THE DAY ON THURSDAY.
THE 00 UTC RAP/HRRR SIMULATED REFLECTIVITY DEPICT NO PRECIPITATION
THE REMAINDER OF THE NIGHT ACROSS EASTERN MONTANA AND WESTERN
NORTH DAKOTA...CONFIRMED BY ALL OTHER DETERMINISTIC MODELS OUTSIDE
OF THE 18 UTC GFS WHICH WAS DISCOUNTED. FOR TOMORROW...THE
SURFACE INSTABILITY AXIS LOOKS TO SETUP PRIMARILY ACROSS
SOUTHEAST MONTANA INTO NORTHEAST WYOMING...AND THUS SCALED BACK
POPS FOR THURSDAY TO JUST NEAR THE MONTANA BORDER. OTHERWISE...THE
FORECAST IS WELL ON TRACK FOR TONIGHT AND TOMORROW.
UPDATE ISSUED AT 648 PM CDT WED MAY 8 2013
NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO THE 23 UTC OBSERVED TRENDS AND THE 22 UTC CONSENSUS
OF THE HIGH RESOLUTION NEAR TERM RAPIDLY UPDATING GUIDANCE. DID
MAINTAIN THE ISOLATED TO SCATTERED MENTION OF SHOWERS AND
THUNDERSTORM ACROSS THE FAR WEST LATE TONIGHT FOR NOW...AND WILL
RE-VISIT WITH THE 00 UTC RUNS. HOWEVER...WILL LIKELY DECREASE OR
REMOVE POPS WITH VERY WEAK FORCING AND MOISTURE ASSOCIATED WITH
THE IMPULSE PROPAGATING SOUTHEAST OUT OF CANADA THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS FOR THE REST OF THIS AFTERNOON AND EVENING WILL BE
THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHEAST.
THE MAIN FOCUS FOR TONIGHT AND TOMORROW WILL BE THE POSSIBILITY OF
SHOWERS AND THUNDERSTORMS IN THE WEST.
A COLD FRONT WAS SLOWLY PUSHING SOUTH THIS AFTERNOON ACROSS FAR
SOUTHERN NORTH DAKOTA. THE COLD FRONT WILL BE THE PRIMARY LOCATION
OF ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP. AHEAD OF THE
FRONT THE ATMOSPHERE CONTINUES TO DESTABILIZE AS EVIDENCED BY THE
CU FIELD IN VISIBLE SATELLITE. THE 17 UTC RAP PAINTS 400+ J/KG OF
CAPE ACROSS SOUTHERN NORTH DAKOTA. THE 15 UTC HRRR MODEL HAS
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ALONG AND AHEAD OF
THE FRONT LATER THIS AFTERNOON. ONE OF THE MAIN LIMITING FACTORS
ON WHETHER SHOWERS AND THUNDERSTORMS DEVELOP AND HOW WIDESPREAD
THEY BECOME IS THE BROAD SYNOPTIC SCALE SUBSIDENCE BEHIND THE
DEPARTING UPPER LEVEL LOW.
LATE TONIGHT AND TOMORROW MORNING A WEAK UPPER LEVEL SHORTWAVE TROUGH
WILL ENTER EASTERN MONTANA AND WESTERN NORTH DAKOTA. THIS SHORTWAVE
MAY PROVIDE ENOUGH ASCENT ALONG A DEVELOPING SURFACE BAROCLINIC
ZONE IN EASTERN MONTANA AND WESTERN NORTH DAKOTA TO SPARK SOME
ISOLATED RAIN SHOWERS. SURFACE HIGH PRESSURE AND COLD AIR
ADVECTION SHOULD KEEP CENTRAL AND EASTERN NORTH DAKOTA DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS OF THE EXTENDED PERIOD WILL BE THE COLD FRONT THAT IS
PROGGED TO DROP SOUTH OUT OF SOUTHERN CANADA AND INTO THE NORTHWEST
BY FRIDAY MORNING. THIS FRONT WILL CONTINUE TO MOVE SOUTH OVER THE
AREA...WITH IT MOVING INTO SOUTH DAKOTA BY EARLY SATURDAY MORNING.
THE CONCERN WILL LIE AHEAD OF THIS FRONT...WHERE THUNDERSTORMS MAY
BE POSSIBLE. ACCORDING TO THE 12Z NAM...SURFACE BASED CAPE AHEAD OF
THIS FRONT WILL BE IN THE 500 TO 600 J/KG RANGE...WITH THE 0-6 KM
BULK SHEAR BEING MORE THAN SUFFICIENT FOR AIDING IN THE DEVELOPMENT
OF SEVERE THUNDERSTORMS. ON THE OTHER HAND...THE GFS DEPICTS THE
STRONG 0-6 KM BULK SHEAR...BUT DOES NOT PAINT ANY SURFACE BASED CAPE
NOR MOST UNSTABLE CAPE OVER THE AREA. MOISTURE WILL ALSO BE A
LIMITING FACTOR AS FORECAST DEWPOINTS WILL ONLY BE IN THE 30S AND
40S. CURRENT THINKING IS THAT THERE WILL BE WIDESPREAD SHOWER
ACTIVITY AHEAD OF THE FRONT AND THAT IF ANY THUNDERSTORMS THAT DO
DEVELOP WILL REMAIN BELOW THE SEVERE THRESHOLD AND WILL BE OF THE
GARDEN VARIETY TYPE.
AHEAD OF THE AFOREMENTIONED COLD FRONT...TEMPERATURES WILL WARM
WITH THE RETURN FLOW AND BE IN THE 60S AND LOWER 70S. AS THE FRONT
MOVES THROUGH THE AREA...TEMPERATURES WILL RETURN TO BELOW
NORMAL...WITH TEMPERATURES IN THE UPPER 40S TO MID 50S. SATURDAY
NIGHT AND INTO SUNDAY MORNING...THERE IS THE POTENTIAL FOR
TEMPERATURES TO FLIRT WITH THE FREEZING MARK ACROSS MOST OF THE AREA
AND POSSIBLY ENDANGER NEW VEGETATION AND PLANT GROWTH.
THEREAFTER...TEMPERATURES WILL AGAIN WARM SUNDAY AS A WARM FRONT
MOVES EAST AND AN UPPER LEVEL RIDGE BUILDS EAST OVER THE NORTHERN
PLAINS. TEMPERATURES WILL CLIMB ABOVE NORMAL MONDAY WITH HIGHS IN
THE LOW TO MID 80S AS THE RIDGE AXIS MOVES OVERHEAD.
FOR THE REMAINDER OF THE PERIOD (TUESDAY ONWARDS)...QUASIZONAL FLOW
WILL DEVELOP AND TEMPERATURES WILL RETURN TO SEASONAL NORMS. THERE
IS A POSSIBILITY FOR SHOWERS AND THUNDERSTORMS DURING MONDAY
EVENING...HOWEVER THEY ARE NOT EXPECTED TO BECOME SEVERE. SHOWERS
WILL CONTINUE THROUGH EARLY THURSDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 937 PM CDT WED MAY 8 2013
VFR CONDITIONS ARE FORECAST FOR THE 00 UTC TAF CYCLE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA WITH SURFACE HIGH PRESSURE IN
PLACE. KEPT THE MENTION OF ISOLATED SHOWERS AND THUNDERSTORMS OUT
OF THE KISN AND KDIK TAFS FOR THURSDAY AS ANY PRECIPITATION
COVERAGE WILL BE VERY LOW AND UNLIKELY TO IMPACT THE TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...LTH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
649 PM CDT WED MAY 8 2013
.UPDATE...
ISSUED AT 648 PM CDT WED MAY 8 2013
NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO THE 23 UTC OBSERVED TRENDS AND THE 22 UTC CONSENSUS
OF THE HIGH RESOLUTION NEAR TERM RAPIDLY UPDATING GUIDANCE. DID
MAINTAIN THE ISOLATED TO SCATTERED MENTION OF SHOWERS AND
THUNDERSTORM ACROSS THE FAR WEST LATE TONIGHT FOR NOW...AND WILL
RE-VISIT WITH THE 00 UTC RUNS. HOWEVER...WILL LIKELY DECREASE OR
REMOVE POPS WITH VERY WEAK FORCING AND MOISTURE ASSOCIATED WITH
THE IMPULSE PROPAGATING SOUTHEAST OUT OF CANADA THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS FOR THE REST OF THIS AFTERNOON AND EVENING WILL BE
THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHEAST.
THE MAIN FOCUS FOR TONIGHT AND TOMORROW WILL BE THE POSSIBILITY OF
SHOWERS AND THUNDERSTORMS IN THE WEST.
A COLD FRONT WAS SLOWLY PUSHING SOUTH THIS AFTERNOON ACROSS FAR
SOUTHERN NORTH DAKOTA. THE COLD FRONT WILL BE THE PRIMARY LOCATION
OF ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP. AHEAD OF THE
FRONT THE ATMOSPHERE CONTINUES TO DESTABILIZE AS EVIDENCED BY THE
CU FIELD IN VISIBLE SATELLITE. THE 17 UTC RAP PAINTS 400+ J/KG OF
CAPE ACROSS SOUTHERN NORTH DAKOTA. THE 15 UTC HRRR MODEL HAS
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ALONG AND AHEAD OF
THE FRONT LATER THIS AFTERNOON. ONE OF THE MAIN LIMITING FACTORS
ON WHETHER SHOWERS AND THUNDERSTORMS DEVELOP AND HOW WIDESPREAD
THEY BECOME IS THE BROAD SYNOPTIC SCALE SUBSIDENCE BEHIND THE
DEPARTING UPPER LEVEL LOW.
LATE TONIGHT AND TOMORROW MORNING A WEAK UPPER LEVEL SHORTWAVE TROUGH
WILL ENTER EASTERN MONTANA AND WESTERN NORTH DAKOTA. THIS SHORTWAVE
MAY PROVIDE ENOUGH ASCENT ALONG A DEVELOPING SURFACE BAROCLINIC
ZONE IN EASTERN MONTANA AND WESTERN NORTH DAKOTA TO SPARK SOME
ISOLATED RAIN SHOWERS. SURFACE HIGH PRESSURE AND COLD AIR
ADVECTION SHOULD KEEP CENTRAL AND EASTERN NORTH DAKOTA DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS OF THE EXTENDED PERIOD WILL BE THE COLD FRONT THAT IS
PROGGED TO DROP SOUTH OUT OF SOUTHERN CANADA AND INTO THE NORTHWEST
BY FRIDAY MORNING. THIS FRONT WILL CONTINUE TO MOVE SOUTH OVER THE
AREA...WITH IT MOVING INTO SOUTH DAKOTA BY EARLY SATURDAY MORNING.
THE CONCERN WILL LIE AHEAD OF THIS FRONT...WHERE THUNDERSTORMS MAY
BE POSSIBLE. ACCORDING TO THE 12Z NAM...SURFACE BASED CAPE AHEAD OF
THIS FRONT WILL BE IN THE 500 TO 600 J/KG RANGE...WITH THE 0-6 KM
BULK SHEAR BEING MORE THAN SUFFICIENT FOR AIDING IN THE DEVELOPMENT
OF SEVERE THUNDERSTORMS. ON THE OTHER HAND...THE GFS DEPICTS THE
STRONG 0-6 KM BULK SHEAR...BUT DOES NOT PAINT ANY SURFACE BASED CAPE
NOR MOST UNSTABLE CAPE OVER THE AREA. MOISTURE WILL ALSO BE A
LIMITING FACTOR AS FORECAST DEWPOINTS WILL ONLY BE IN THE 30S AND
40S. CURRENT THINKING IS THAT THERE WILL BE WIDESPREAD SHOWER
ACTIVITY AHEAD OF THE FRONT AND THAT IF ANY THUNDERSTORMS THAT DO
DEVELOP WILL REMAIN BELOW THE SEVERE THRESHOLD AND WILL BE OF THE
GARDEN VARIETY TYPE.
AHEAD OF THE AFOREMENTIONED COLD FRONT...TEMPERATURES WILL WARM
WITH THE RETURN FLOW AND BE IN THE 60S AND LOWER 70S. AS THE FRONT
MOVES THROUGH THE AREA...TEMPERATURES WILL RETURN TO BELOW
NORMAL...WITH TEMPERATURES IN THE UPPER 40S TO MID 50S. SATURDAY
NIGHT AND INTO SUNDAY MORNING...THERE IS THE POTENTIAL FOR
TEMPERATURES TO FLIRT WITH THE FREEZING MARK ACROSS MOST OF THE AREA
AND POSSIBLY ENDANGER NEW VEGETATION AND PLANT GROWTH.
THEREAFTER...TEMPERATURES WILL AGAIN WARM SUNDAY AS A WARM FRONT
MOVES EAST AND AN UPPER LEVEL RIDGE BUILDS EAST OVER THE NORTHERN
PLAINS. TEMPERATURES WILL CLIMB ABOVE NORMAL MONDAY WITH HIGHS IN
THE LOW TO MID 80S AS THE RIDGE AXIS MOVES OVERHEAD.
FOR THE REMAINDER OF THE PERIOD (TUESDAY ONWARDS)...QUASIZONAL FLOW
WILL DEVELOP AND TEMPERATURES WILL RETURN TO SEASONAL NORMS. THERE
IS A POSSIBILITY FOR SHOWERS AND THUNDERSTORMS DURING MONDAY
EVENING...HOWEVER THEY ARE NOT EXPECTED TO BECOME SEVERE. SHOWERS
WILL CONTINUE THROUGH EARLY THURSDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 648 PM CDT WED MAY 8 2013
VFR CONDITIONS ARE FORECAST FOR THE 00 UTC TAF CYCLE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. NORTHEAST WIND GUSTS OF 20-25
KTS WILL DECREASE WITH SUNSET THIS EVENING. KEPT SHOWERS OUT OF
THE KISN AND KDIK TAFS FOR TONIGHT INTO TOMORROW AS ANY
PRECIPITATION COVERAGE WILL BE VERY LOW AND UNLIKELY TO IMPACT THE
TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...LTH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
154 PM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE WESTERN CAROLINAS WILL SLOWLY DRIFT
NORTHEAST REACHING THE MID ATLANTIC REGION ON WEDNESDAY. WEAK HIGH
PRESSURE WILL THEN FILL IN BEHIND THE UPPER LOW THURSDAY AND BRING
SEASONAL TEMPERATURES BACK TO THE REGION THROUGH FRIDAY. ANOTHER
COLD FRONT WILL MOVE THROUGH THE CAROLINAS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...LOWERED POPS THIS MORNING...BUT KEPT SCHC POPS IN
MUCH OF THE MTNS AND NEAR ACTIVITY N AND SE OF THE CWFA WHERE
ENHANCED CU DEVELOPMENT NOTED. LATEST RAP REFLECTIVITY FCSTS SHOW
WIDESPREAD CONVECTIVE DEVELOPMENT BY MIDDAY BUT WITHOUT SUFFICIENT
DBZ TO EXPECT THUNDER IN THAT SCENARIO. 09Z SREF SHOWS HIGH PROBS OF
250 J CAPE BUT LOW PROBS OF 500 J. HAVE GOOD CONFIDENCE IN HIGH CHC
POPS FOR MOST PLACES WITH LOW LKLYS IN THE MTNS. DID MAINTAIN A TSTM
MENTION...BUT BACKED OFF PROBABILITY AND DELAYED ONSET OF THUNDER BY
A COUPLE HOURS TO ALLOW FIGURATIVE CU TO GROW.
CLOSED UPPER LOW CENTER...CURRENTLY PIVOTING ESE INTO GA...WILL BE
THE SYNOPTIC SCALE FEATURE OF INTEREST AS IT WOBBLES EAST ATOP THE
CWFA TODAY AND TOWARD THE VA PIEDMONT LATER TONIGHT. CLOSER TO THE
TRACK OF IT/S WEAK SFC REFLECTION...SHOWER CHANCES WILL BE GREATEST
THIS MORNING ACRS THE GA/SC PIEDMONT...BUT EXPAND AS THE DAY WEARS
ON WITHIN THE DEVELOPING WEAK INSTABILITY UNDER MID-LVL COOL POOL/
UPPER LOW CENTER. SHOWERS AND A FEW THUNDERSTORMS SHOULD BECOME
NUMEROUS THIS AFTERNOON...BUT WITH FCST SNDGS PROGGING JUST A THIN
AREA OF CAPE...WOULD BELIEVE EVEN THE TALLEST STORMS WOULD STRUGGLE
TO PRODUCE EVEN SMALL HAIL DESPITE THE LOW WBZ HEIGHTS. FOR MAX TEMPS
TODAY...HAVE MADE LITTLE MORE THAN TWEAKS TO THE INHERITED COOL
NUMBERS...ABOUT 8-10 DEG F BELOW CLIMO. DEEP CONVECTIVE CHANCES
SHOULD DIMINISH THIS EVENING WITH LOSS OF HTG...BUT THE POTENTIAL
FOR REDEVELOPMENT OF SHOWERS WITHIN DEFORMATION ZONE EXISTS
TONIGHT...ESPECIALLY ACRS W NC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 315 AM TUESDAY...THE UPPER LOW WILL FINALLY SPIN AWAY TO THE
NORTHEAST ACROSS THE MID ATLANTIC REGION ON WEDNESDAY. RESIDUAL LOW
LEVEL MOISTURE AND COOLER AIR ALOFT SHOULD BE ENOUGH TO PROVIDE FOR
SOME INSTABILITY WITH DAYTIME HEATING WHILE THE ATMOSPHERE REMAINS
GENERALLY FAVORABLE FOR CONVECTION. A CHANCE OF SHOWERS AND SOME
THUNDERSTORMS STILL LOOKS LIKE A DECENT BET FOR WEDNESDAY
AFTERNOON...WITH SOME OF THAT ACTIVITY PERSISTING INTO THE EVENING.
TEMPS SHOULD REBOUND NICELY...BUT STILL BELOW NORMAL...WITH
ADDITIONAL SUN IN THE AFTERNOON.
AS THE UPPER LOW MOVES AWAY WEDNESDAY NIGHT AND THURSDAY...SOME
UPPER RIDGING WILL MOVE IN FROM THE WEST. THAT SHOULD PROVIDE FOR A
RELATIVELY QUIET PERIOD AS WEAK HIGH PRESSURE MOVES IN. THURSDAY
WILL NOT BE AS FAVORABLE FOR CONVECTION AS LOW LEVELS SHOULD BE
SOMEWHAT DRIER. THUS...HAVE LIMITED THE PRECIP CHANCES TO SLIGHT AND
MAINLY OVER THE MTNS AND FOOTHILLS. TEMPS WILL FINALLY MAKE IT BACK
TO NEAR NORMAL AND WE SHOULD CONTINUE TO DRY OUT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 225 PM MONDAY...THE WET PATTERN WILL CONTINUE INTO THE EARLY
PART OF THE MEDIUM RANGE...AS A COLD FRONT ASSOCIATED WITH OHIO/MISS
VALLEY HEIGHT FALLS APPROACHES THE EASTERN STATES DURING LATE WEEK.
THIS WILL ENHANCE DIURNAL CONVECTIVE CHANCES ON FRIDAY...AND POPS IN
THE 30-50 PERCENT RANGE WILL BE ADVERTISED DURING THIS TIME. MUCH
MORE SUBSTANTIAL HEIGHT FALLS WILL OCCUR ACROSS THE EASTERN CONUS
OVER THE WEEKEND...CARVING OUT A MAJOR EASTERN TROUGH BY THE END OF
THE PERIOD. THIS WILL DRIVE A MORE SIGNIFICANT FRONTAL BOUNDARY INTO
THE REGION...SUPPORTING 50/60 POPS ACROSS THE FORECAST AREA BY
SATURDAY AFTERNOON...WITH HEALTHY POPS CONTINUING INTO SUNDAY.
TEMPERATURES SHOULD GENERALLY AVERAGE NEAR NORMAL THROUGH SUNDAY.
A MODEL CONSENSUS STRONGLY SUGGESTS THAT THE COLD FRONT WILL SWEEP
EAST OF THE AREA BY DAY 7...INTRODUCING MUCH COOLER AND (FINALLY)
DRIER AIR. POPS WILL TAPER DOWN TO SLIGHT CHANCE AT BEST BY DAY
7...WHILE TEMPERATURES WILL COOL WELL BELOW NORMAL IN A REGIME
CHARACTERIZED BY ANOMALOUSLY LOW HEIGHTS ALOFT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...DESPITE CONVECTIVE DEVELOPMENT WELL SOUTH OF THE FIELD
LITTLE LIGHTNING SEEN WITH ACTIVITY IN THAT AREA...SO THUNDER
CHANCES APPEAR TOO SMALL TO MENTION. INCLUDED MVFR SHRA IN A TEMPO
FOR NOW AND WILL WATCH TRENDS. CONVECTION AND SHOWER CHANCES WILL
DIMINISH BY SUNSET. MIDLEVEL MOISTURE INCREASES SOMEWHAT OVERNIGHT
BUT GUIDANCE KEEPS CIGS VFR...AND DESPITE HIGH SFC RH PROFILES ARE
UNFAVORABLE FOR FOG. SIMILAR TOMORROW IN THAT A FAIR AMOUNT OF
CONVECTION EXPECTED IN THE AREA...THOUGH CONDITIONS WILL BE A LITTLE
MORE STABLE. CHANCES WARRANT A PROB30 -SHRA AT THIS POINT.
ELSEWHERE...SCT TO NUMEROUS SHOWERS WILL CONTINUE THIS AFTERNOON
THOUGH THUNDERSTORMS WILL REMAIN ISOLATED. HIGHEST CHANCES IN BETTER
LLVL FORCING ALONG THE NRN BLUE RIDGE. VFR CIGS EXCEPT PERHAPS BRIEF
PERIODS OF MVFR IN HEAVIER SHOWERS. THINGS QUIET DOWN BY EVENING AS
DIURNAL INSTABILITY WANES. UPPER LEVEL IMPULSE EXPECTED TO REDEVELOP
SOME SHOWERS AS MIDLEVEL MOISTURE ARRIVES LATE...BUT THESE WILL
MAINLY AFFECT THE NW HALF OF THE AREA. KHKY AND KAVL LIKELY TO SEE
RESTRICTIONS AGAIN AS THEY DID THIS MORNING...BUT THINK THE MID
CLOUDS AND MVFR CIGS WILL PREVENT FOG DEVELOPMENT. EXPECT SOME
ISOLD/SCT CONVECTION AROUND THE AREA BY MIDDAY WED...THOUGH CHANCES
TOO LOW TO MENTION WITH THIS PACKAGE.
OUTLOOK...A MID LEVEL LOW WILL MOVE NORTHWARD OUT OF THE REGION
MIDWEEK ALLOWING FOR A BRIEF PERIOD OF MORE SETTLED WEATHER BY
THURSDAY. AFTERNOON SHOWERS AND THUNDERSTORM CHANCES WILL RETURN BY
FRIDAY.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 94% HIGH 88% HIGH 100%
KHKY HIGH 100% HIGH 100% MED 71% HIGH 87%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 97% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PAT
NEAR TERM...CSH/WIMBERLEY
SHORT TERM...PM
LONG TERM...JDL
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1026 AM EDT TUE MAY 7 2013
.SYNOPSIS...
AN UPPER LEVEL LOW OVER THE WESTERN CAROLINAS TODAY WILL MOVE SLOWLY
NORTHEAST THROUGH TONIGHT AND OVER THE MID ATLANTIC REGION ON
WEDNESDAY. WEAK HIGH PRESSURE WILL THEN FILL IN BEHIND THE UPPER LOW
THURSDAY AND BRING SEASONAL TEMPERATURES BACK TO THE REGION THROUGH
FRIDAY. A WEAK COLD FRONT WILL APPROACH AND MOVE OVER THE CAROLINAS
OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...LOWERED POPS THIS MORNING...BUT KEPT SCHC POPS IN
MUCH OF THE MTNS AND NEAR ACTIVITY N AND SE OF THE CWFA WHERE
ENHANCED CU DEVELOPMENT NOTED. LATEST RAP REFLECTIVITY FCSTS SHOW
WIDESPREAD CONVECTIVE DEVELOPMENT BY MIDDAY BUT WITHOUT SUFFICIENT
DBZ TO EXPECT THUNDER IN THAT SCENARIO. 09Z SREF SHOWS HIGH PROBS OF
250 J CAPE BUT LOW PROBS OF 500 J. HAVE GOOD CONFIDENCE IN HIGH CHC
POPS FOR MOST PLACES WITH LOW LKLYS IN THE MTNS. DID MAINTAIN A TSTM
MENTION...BUT BACKED OFF PROBABILITY AND DELAYED ONSET OF THUNDER BY
A COUPLE HOURS TO ALLOW FIGURATIVE CU TO GROW.
CLOSED UPPER LOW CENTER...CURRENTLY PIVOTING ESE INTO GA...WILL BE
THE SYNOPTIC SCALE FEATURE OF INTEREST AS IT WOBBLES EAST ATOP THE
CWFA TODAY AND TOWARD THE VA PIEDMONT LATER TONIGHT. CLOSER TO THE
TRACK OF IT/S WEAK SFC REFLECTION...SHOWER CHANCES WILL BE GREATEST
THIS MORNING ACRS THE GA/SC PIEDMONT...BUT EXPAND AS THE DAY WEARS
ON WITHIN THE DEVELOPING WEAK INSTABILITY UNDER MID-LVL COOL POOL/
UPPER LOW CENTER. SHOWERS AND A FEW THUNDERSTORMS SHOULD BECOME
NUMEROUS THIS AFTERNOON...BUT WITH FCST SNDGS PROGGING JUST A THIN
AREA OF CAPE...WOULD BELIEVE EVEN THE TALLEST STORMS WOULD STRUGGLE
TO PRODUCE EVEN SMALL HAIL DESPITE THE LOW WBZ HEIGHTS. FOR MAX TEMPS
TODAY...HAVE MADE LITTLE MORE THAN TWEAKS TO THE INHERITED COOL
NUMBERS...ABOUT 8-10 DEG F BELOW CLIMO. DEEP CONVECTIVE CHANCES
SHOULD DIMINISH THIS EVENING WITH LOSS OF HTG...BUT THE POTENTIAL
FOR REDEVELOPMENT OF SHOWERS WITHIN DEFORMATION ZONE EXISTS
TONIGHT...ESPECIALLY ACRS W NC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 315 AM TUESDAY...THE UPPER LOW WILL FINALLY SPIN AWAY TO THE
NORTHEAST ACROSS THE MID ATLANTIC REGION ON WEDNESDAY. RESIDUAL LOW
LEVEL MOISTURE AND COOLER AIR ALOFT SHOULD BE ENOUGH TO PROVIDE FOR
SOME INSTABILITY WITH DAYTIME HEATING WHILE THE ATMOSPHERE REMAINS
GENERALLY FAVORABLE FOR CONVECTION. A CHANCE OF SHOWERS AND SOME
THUNDERSTORMS STILL LOOKS LIKE A DECENT BET FOR WEDNESDAY
AFTERNOON...WITH SOME OF THAT ACTIVITY PERSISTING INTO THE EVENING.
TEMPS SHOULD REBOUND NICELY...BUT STILL BELOW NORMAL...WITH
ADDITIONAL SUN IN THE AFTERNOON.
AS THE UPPER LOW MOVES AWAY WEDNESDAY NIGHT AND THURSDAY...SOME
UPPER RIDGING WILL MOVE IN FROM THE WEST. THAT SHOULD PROVIDE FOR A
RELATIVELY QUIET PERIOD AS WEAK HIGH PRESSURE MOVES IN. THURSDAY
WILL NOT BE AS FAVORABLE FOR CONVECTION AS LOW LEVELS SHOULD BE
SOMEWHAT DRIER. THUS...HAVE LIMITED THE PRECIP CHANCES TO SLIGHT AND
MAINLY OVER THE MTNS AND FOOTHILLS. TEMPS WILL FINALLY MAKE IT BACK
TO NEAR NORMAL AND WE SHOULD CONTINUE TO DRY OUT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 225 PM MONDAY...THE WET PATTERN WILL CONTINUE INTO THE EARLY
PART OF THE MEDIUM RANGE...AS A COLD FRONT ASSOCIATED WITH OHIO/MISS
VALLEY HEIGHT FALLS APPROACHES THE EASTERN STATES DURING LATE WEEK.
THIS WILL ENHANCE DIURNAL CONVECTIVE CHANCES ON FRIDAY...AND POPS IN
THE 30-50 PERCENT RANGE WILL BE ADVERTISED DURING THIS TIME. MUCH
MORE SUBSTANTIAL HEIGHT FALLS WILL OCCUR ACROSS THE EASTERN CONUS
OVER THE WEEKEND...CARVING OUT A MAJOR EASTERN TROUGH BY THE END OF
THE PERIOD. THIS WILL DRIVE A MORE SIGNIFICANT FRONTAL BOUNDARY INTO
THE REGION...SUPPORTING 50/60 POPS ACROSS THE FORECAST AREA BY
SATURDAY AFTERNOON...WITH HEALTHY POPS CONTINUING INTO SUNDAY.
TEMPERATURES SHOULD GENERALLY AVERAGE NEAR NORMAL THROUGH SUNDAY.
A MODEL CONSENSUS STRONGLY SUGGESTS THAT THE COLD FRONT WILL SWEEP
EAST OF THE AREA BY DAY 7...INTRODUCING MUCH COOLER AND (FINALLY)
DRIER AIR. POPS WILL TAPER DOWN TO SLIGHT CHANCE AT BEST BY DAY
7...WHILE TEMPERATURES WILL COOL WELL BELOW NORMAL IN A REGIME
CHARACTERIZED BY ANOMALOUSLY LOW HEIGHTS ALOFT.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AT KCLT /15Z UPDATE/...CU DEVELOPMENT AS SHOWN ON SATELLITE LAGS
GUIDANCE A BIT AND NOW THINK THAT WHEN CU FORM THEY ARE LIKELY TO BE
WELL INTO VFR RANGE BEFORE MAKING A CIG. FURTHERMORE...PER LATEST
RAP SIMULATED RADAR AND SREF CAPE PROBABILITIES...INSTABILITY
APPEARS TO BE LIMITED ENOUGH THIS AFTN TO PRECLUDE THUNDER AT THE
FIELD. INCLUDED TEMPO FOR MVFR SHRA TO REPLACE PROB30 TSRA FROM 12Z
TAF.
ELSEWHERE...SIMILAR TO KCLT. SHOWER AND/OR TSTM CVRG SHOULD BECOME
NUMEROUS AS THE DAY WEARS ON...BUT CONFIDENCE OF OCCURRENCE AT ANY
ONE TERMINAL IS NOT HIGH ENUF TO GO HIGHER THAN A PROB30 OR TEMPO.
MOIST ENOUGH TONIGHT IN THE MTNS/FOOTHILLS TO EXPECT MINOR VSBY
RESTRICTIONS AT KAVL/KHKY THOUGH HIGHER CLOUDS SHOULD PREVENT
RESTRICTIONS BELOW MVFR AT THOSE SITES.
OUTLOOK...A MID LEVEL LOW WILL SLOW TRACK NE ACROSS THE CAROLINAS
AND MID ATLANTIC STATES THROUGH WED. RESTRICTIVE CEILINGS AND VIS
ARE POSSIBLE AROUND SUNRISE WED MORNING...ESPECIALLY THE MTN
VALLEYS.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 87% HIGH 93%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 93%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND MED 78% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...CSH/WIMBERLEY
SHORT TERM...PM
LONG TERM...JDL
AVIATION...CSH/WIMBERLEY
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1250 PM CDT TUE MAY 7 2013
.AVIATION...
FOR THE 18Z TAFS...VFR CONDITIONS AND SOUTH FLOW ARE EXPECTED
THROUGH THE VALID FORECAST PERIOD.
IN GENERAL...RELATIVELY DRY AIR IN PLACE WILL BE THE PRIMARY
REASON VFR CONDITIONS HOLD OVER THE NEXT 24 TO 30 HRS. LEE SIDE
TROUGHING WILL PERSIST THROUGH THE PERIOD WHICH WILL KEEP WINDS IN
A GENERAL SOUTHERLY DIRECTION WITH A WEAK PRESSURE GRADIENT
SUPPORTING WIND SPEEDS BELOW 15 KTS.
FORECAST CONCERNS NOT MENTIONED IN THE TAFS INCLUDE STRATUS
CHANCES TOMORROW MORNING AND THUNDERSTORM CHANCES LATE THIS
AFTERNOON AND WEDNESDAY AFTERNOON.
STRATUS...THE NAM BRINGS A SURGE OF LOW-LEVEL RH UP THROUGH WACO
BY EARLY TOMORROW MORNING AND FORECAST SOUNDINGS SEEM TO SUPPORT
IFR STRATUS AFTER 11Z. THE RAP AND GFS ARE NOWHERE NEAR AS
AGGRESSIVE WITH THIS MOISTURE SURGE NEAR WACO TONIGHT...SO LEFT
STRATUS OUT OF THE KACT TAF AT THIS TIME. THE NAM WAS AGGRESSIVE
WITH SHALLOW MOISTURE RETURN LAST NIGHT AS WELL AND NO STRATUS
DEVELOPED. SOMETHING TO WATCH FOR IN FUTURE TAFS...BUT CONFIDENCE
IN VFR CONDITIONS IS FAIRLY HIGH AT THIS TIME.
THUNDERSTORM CHANCES...THUNDERSTORMS WILL LIKELY DEVELOP ALONG THE
DRYLINE ACROSS WEST TX THIS AFTERNOON OR EVENING. THESE STORMS ARE
NOT EXPECTED TO MOVE OVER ANY AREA TAF SITE THROUGH TONIGHT. THESE
STORMS WILL LIKELY SEND A BROKEN OR OVERCAST DECK OF CLOUDS AOA
15000 FT THIS EVENING...BUT THIS IS A VFR CIG...SO DID NOT PLACE A
CHANGE GROUP IN THE TAFS TO ACCOUNT FOR THIS. STORMS MAY GET
CLOSER TO DFW AREA TAF SITES WEDNESDAY EVENING AS STORMS PULL OFF
THE DRYLINE ONCE AGAIN...HOWEVER THIS WOULD LIKELY OCCUR AFTER 00Z
OR BEYOND THE DFW EXTENDED TAF.
CAVANAUGH
&&
.UPDATE...
LIGHT PRECIPITATION ASSOCIATED WITH A WEAK DISTURBANCE OVER THE
PLAINS CONTINUES TO SHOW UP ON RADAR OVER SOUTHWEST OKLAHOMA AND
NORTHWEST TEXAS. MEANWHILE UPPER LEVEL RIDGING OVER TEXAS
CONTINUES TO SHUT DOWN THIS PRECIP AS IT ATTEMPTS TO MOVE
SOUTHEAST INTO OUR NORTHERN COUNTIES. THERE MAY STILL BE A
SPRINKLE OR TWO OVER THE NORTHERN-MOST COUNTIES LATE THIS
MORNING...OTHERWISE MOSTLY SUNNY SKIES AND LIGHT SOUTH WINDS CAN
BE EXPECTED ACROSS THE REGION.
SOME OF THE LATEST HIGH-RESOLUTION GUIDANCE INDICATES STORM
DEVELOPMENT LATE THIS AFTERNOON AND THIS EVENING OVER WEST TX
AS A SUBTLE SHORTWAVE PROPAGATES ACROSS THE AREA...WITH SOME OF
THE ACTIVITY APPROACHING THE FAR NORTHWESTERN COUNTIES THIS
EVENING. WILL LEAVE POPS ALONE FOR NOW BUT WILL KEEP OPEN THE
POSSIBILITY OF ADDING LOW POPS NORTHWEST OF THE METROPLEX IN THE
AFTERNOON PACKAGE IF ADDITIONAL MODEL DATA SUPPORTS IT. FOR NOW
THE THOUGHT IS THAT THE RIDGE WILL TEND TO PREVENT CONVECTION
FROM REACHING NORTH TEXAS THIS AFTERNOON AND EVENING. IT STILL
LOOKS LIKE OUR BEST RAIN CHANCES WILL BE THURSDAY NIGHT AND
FRIDAY.
30
&&
.PREV DISCUSSION... /ISSUED 401 AM CDT TUE MAY 7 2013/
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ACROSS
WEST TEXAS AND WEAKEN AS THEY APPROACH THE FORECAST AREA. GIVEN
HOW DRY IT IS IN THE LOWER 5000-6000 FEET...BELIEVE THAT JUST
LEAVING SOME SPRINKLES IN WILL SUFFICE SO WILL KEEP 10 PERCENT
POPS AND MENTION SOME SPRINKLES FOR THIS MORNING SOUTHWEST OF A
JACKSBORO TO WAXAHACHIE TO ATHENS LINE. OTHERWISE...DESPITE THE
MID AND HIGH CLOUDS...TEMPERATURES WILL WARM IN THE 80S ACROSS
MOST OF THE FORECAST AREA. WE WILL SEE AT OR ABOVE SEASONAL NORMAL
TEMPERATURES FOR THE NEXT SEVERAL DAYS.
AS THE UPPER LEVEL LOW CURRENTLY OVER CENTRAL/SOUTHERN CALIFORNIA
MOVES EAST TOWARD THE CENTRAL PLAINS...THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS TOMORROW AFTERNOON/EVENING MAINLY ALONG
AND WEST OF A BOWIE TO GOLDTHWAITE LINE AS DRYLINE ACTIVITY MOVES
EAST/NORTHEAST. A FEW OF THESE STORMS WILL BE CAPABLE OF
PRODUCING LARGE HAIL. A LOW CHANCE OF SHOWERS AND THUNDERSTORMS
WILL EXTEND ACROSS NORTHWESTERN TWO-THIRDS OF THE FORECAST
OVERNIGHT TOMORROW NIGHT.
THE UPPER LOW WILL OPEN UP AS IT MOVES SLOWLY EAST ACROSS THE
CENTRAL PLAINS THURSDAY INTO FRIDAY. AS THE TROUGH MOVES EAST...A
COLD FRONT WILL MOVE SOUTHEAST INTO THE NORTHWESTERN ZONES BEFORE
DAYBREAK FRIDAY AND THROUGH THE SOUTHEAST BY FRIDAY EVENING. WE
WILL SEE A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY THROUGH
FRIDAY...WITH A FEW SEVERE STORMS POSSIBLE.
RAIN CHANCES WILL CONTINUE INTO SATURDAY BEHIND THE FRONT BEFORE
THE PRECIPITATION ENDS FROM NORTH TO SOUTH LATE AFTERNOON INTO
SATURDAY NIGHT.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 82 63 85 63 82 / 10 10 10 20 20
WACO, TX 84 60 85 63 82 / 10 10 10 20 20
PARIS, TX 82 58 84 60 81 / 10 10 10 20 20
DENTON, TX 81 61 84 62 83 / 10 10 10 20 20
MCKINNEY, TX 81 60 85 61 83 / 10 10 10 20 20
DALLAS, TX 84 63 87 64 85 / 10 10 10 20 20
TERRELL, TX 82 59 86 61 82 / 10 10 10 20 20
CORSICANA, TX 83 60 86 62 82 / 10 10 10 20 20
TEMPLE, TX 84 60 84 63 81 / 10 10 10 20 20
MINERAL WELLS, TX 84 61 86 62 85 / 10 10 20 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS NEW YORK NY
151 AM EDT THU MAY 9 2013
.SYNOPSIS...
WEAK LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK
NORTHEAST AND ACROSS THE AREA ON THURSDAY. A SLOW MOVING COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY AND FRIDAY NIGHT AND
EVENTUALLY PASS EAST SATURDAY NIGHT INTO SUNDAY MORNING. HIGH
PRESSURE THEN RETURNS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ISSUED A FOG ADVY FOR ERN LI AND SERN CT BASED ON OBS AND STLT.
WIDESPREAD VSBY 1/4 MILE OR LESS...ESPECIALLY THE TWIN FORKS.
ORGANIZED SHOWERS REMAIN OVER CNTRL NEW ENGLAND AS OF MIDNIGHT.
HRRR IS PERFORMING WELL AS KEEPS THE AREA DRY UNTIL 08-09Z WHEN
A SHORTWAVE/VORT MAX ASSOCIATED WITH UPPER LOW MOVES TOWARDS THE
REGION. SHOWERS ASSOCIATED WITH THIS FEATURE ARE CURRENTLY OVER
THE DELMARVA PENINSULA AND ETA INTO THE SW PORTION OF THE AREA IS
CURRENTLY TIMED TO BE SLIGHTLY EARLIER (06-08Z) THAN THE HRRR IS
INDICATING. THEREFORE...WILL LEAVE INCREASING POPS AFTER 04Z AS
SCT SHOWERS MAY BEGIN TO DEVELOP AHEAD OF THE MAIN AREA. ALSO
REMOVED THUNDER FROM THE FORECAST TONIGHT WITH ONLY VERY WEAK
INSTABILITY EXPECTED TO BE PRESENT ALOFT.
THE ESE FLOW WILL VEER TO A MORE SOUTHERLY FLOW OVERNIGHT AS THE
OCCLUDED FRONT LIFTS NORTH OF THE AREA.
LOWS WILL RANGE FROM THE LOWER TO UPPER 50S. STAYED CLOSE TO MOS
GUIDANCE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
THE UPPER LOW TRACKS ACROSS THE AREA ON THU WITH STEEPENING LAPSE
RATES AND PLENTY OF INSTABILITY CLOUDS AND SHOWERS. THE BEST CHANCE
LOOKS TO BE IN THE MORNING WITH THE BEST LIFT AND DEEPEST
MOISTURE. RAINFALL AMOUNTS ARE EXPECTED TO BE LESS THAN ONE-
QUARTER INCH...HOWEVER ISOLATED HIGHER AMOUNTS ARE POSSIBLE WITH
ANY THUNDERSTORMS. THIS ACTIVITY SHOULD NOT BE AS ORGANIZED AS
THE CONVECTIVE BANDS THAT WENT THROUGH THE AREA ON WED.
HIGHS WILL TOP OUT IN THE LOWER 60S AT THE COAST...TO THE LOWER
70S NORTH AND WEST OF NYC. THIS IS CLOSE TO NORMAL. USED A BLEND
OF THE MOS GUIDANCE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WEAK DEEP-LAYERED RIDGING SHOULD KEEP US DRY FOR MOST OF THE DAY ON
FRIDAY...HOWEVER THERE COULD BE A LATE DAY THUNDERSTORM FROM AROUND
THE CITY AND POINTS WEST. BASED ON 850MB TEMPS...WENT CLOSER TO NAM
MOS HIGH TEMPERATURES...BUT LOWERED THEM BY A FEW DEGREES ALONG THE
SOUTH FACING SHORES.
A COLD FRONT SLOWLY APPROACHES FRIDAY NIGHT WITH A CHANCE OF A
SHOWER OR TSTM...HOWEVER SHOWERS AND POSSIBLE TSTMS LOOK TO
BE MOST LIKELY DURING SATURDAY AND SATURDAY NIGHT WITH THE FRONT
ENTERING THE AREA. BY DAYBREAK ON SUNDAY...THE FRONT IS MOST LIKELY
EAST OF THE CITY...SO JUST A LINGERING SHOWER POSSIBLE SUNDAY
MORNING. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT SUNDAY
AFTERNOON WITH CLEARING SKIES. HIGHS GENERALLY 70-75 ON SATURDAY AND
65-70 ON SUNDAY.
AN UPPER TROUGH SHIFTS INTO THE REGION ON MONDAY/MONDAY NIGHT.
PROBABLY JUST SOME DIURNAL CU BUILDUP...SO WILL KEEP THE FORECAST
DRY FOR NOW. HIGH TEMPS COLDER THAN NORMAL. THE TROUGH SHIFTS EAST
ON TUESDAY WITH MODERATING TEMPERATURES. WILL GO WITH A DRY FORECAST
ON WEDNESDAY FOR NOW...BUT MODELS DEPICT SOME MOISTURE SPILLING OVER
AN UPPER RIDGE TO THE WEST. MAY NEED TO EVENTUALLY INCLUDE CHANCES OF
SHOWERS FOR THIS PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SLOW MOVING LOW PRESSURE WILL MOVE THROUGH THE AREA THROUGH TODAY
WITH AN ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH OVERNIGHT.
CURRENTLY VFR ACROSS NYC TERMINALS. LOW CONFIDENCE IN DURATION OF
IFR/MVFR CIGS EARLY THIS MORNING. STRATUS AND FOG HAS DEVELOPED
ACROSS LONG ISLAND AND COASTAL CONNECTICUT WITH IFR/LIFR CONDS.
CURRENTLY KISP IS VFR...BUT STILL EXPECT CIGS TO FLUCTUATE BETWEEN
IFR/LIFR. AMENDMENTS ARE LIKELY.
AN AREA OF RAIN IS EXPECTED TO MOVE OVER NYC TERMINALS AROUND 09Z
AND THEN ELSEWHERE LATER THIS MORNING. THIS RAIN COULD ALSO
PREVENT CIGS ACROSS NYC FROM FALLING BELOW MVFR. AS THE RAIN MOVES
OVER LONG ISLAND AND COASTAL CONNECTICUT...CONDITIONS WILL LIKELY
IMPROVE A LITTLE.
LOW CONFIDENCE IN CIGS AFTER 12Z. PERIODS OF RAIN ARE LIKELY WITH
AN ISOLATED THUNDERSTORM ALSO POSSIBLE TODAY. AS THE LOW MOVES TO
THE NORTH OF THE AREA LATE IN THE FORECAST PERIOD...WINDS WILL
BECOME LIGHT FROM THE SOUTH AND SOUTHWEST.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.TONIGHT...IMPROVING CONDITIONS WITH SHOWERS ENDING.
.FRIDAY...CHANCE OF BRIEF MVFR OR LOWER CONDS IN ANY SCT SHOWERS IN
THE AFTERNOON. AN ISOLD TSTM POSSIBLE.
.FRIDAY NIGHT-SUNDAY MORNING...MVFR OR LOWER CONDS LIKELY IN ANY
SHOWERS... MAINLY THROUGH SUNDAY MORNING. AN ISOLD TSTM POSSIBLE SAT
AFTERNOON/EARLY EVENING
.SUNDAY AFTERNOON-MONDAY...VFR.
&&
.MARINE...
ISSUED A FOG ADVY FOR ALL WATERS BUT THE HARBOR WITH DEW POINT
DEPRESSIONS NEAR ZERO. OTHERWISE...SCA FOR HAZARDOUS SEAS REMAINS
IN EFFECT FOR THE OCEAN THROUGH THU. SEAS 4 TO 6 FT IN A SLY SWELL
BEGIN TO GRADUALLY SUBSIDE TO BELOW 5 FT BY THU EVENING. SEAS MAY
LINGER ABOVE 5 FT EAST OF MORICHES INLET FOR A PORTION OF THU
NIGHT.
SEAS REMAIN JUST BELOW SCA CRITERIA ON FRIDAY...THEN BUILD UP TO
5 FT FRIDAY NIGHT ON AN INCREASING SW FLOW. GUSTS ON THE OCEAN
WATERS COULD ALSO REACH 25 KT DURING THE DAYTIME ON SATURDAY AND
SATURDAY EVENING AHEAD OF AN APPROACHING COLD FRONT. WINDS AND
SEAS THEN DIMINISH ON SUNDAY AFTER THE PASSAGE OF THE COLD FRONT
WITH SEAS BELOW 5 FT PERHAPS BY THE END OF THE MORNING. AN
OFFSHORE FLOW THEN MAINTAINS SUB SCA CONDITIONS THROUGH MONDAY.
&&
.HYDROLOGY...
AN ADDITIONAL QUARTER INCH IS POSSIBLE THROUGH THU WITH ISOLATED
HIGHER AMOUNTS WITH ANY THUNDERSTORMS. THIS IN ASSOCIATION WITH
THE UPPER LOW TRACKING ACROSS THE AREA.
ANOTHER HALF INCH TO INCH OF RAINFALL IS POSSIBLE FROM LATE
FRIDAY THROUGH SUNDAY MORNING IN ASSOCIATION WITH A SLOWLY-MOVING
COLD FRONT. LOCALLY HIGHER AMOUNTS ARE POSSIBLE WITH
THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR CTZ010>012.
NY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NYZ078>081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT THIS
EVENING FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...JMC/DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...DS
MARINE...JMC/JC/DW
HYDROLOGY...JC/DW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1210 AM EDT THU MAY 9 2013
.SYNOPSIS...
WEAK LOW PRESSURE OVER THE MID ATLANTIC STATES WILL TRACK
NORTHEAST AND ACROSS THE AREA ON THURSDAY. A SLOW MOVING COLD
FRONT WILL APPROACH FROM THE WEST FRIDAY AND FRIDAY NIGHT AND
EVENTUALLY PASS EAST SATURDAY NIGHT INTO SUNDAY MORNING. HIGH
PRESSURE THEN RETURNS EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ISSUED A FOG ADVY FOR ERN LI AND SERN CT BASED ON OBS AND STLT.
WIDESPREAD VSBY 1/4 MILE OR LESS...ESPECIALLY THE TWIN FORKS.
ORGANIZED SHOWERS REMAIN OVER CNTRL NEW ENGLAND AS OF MIDNIGHT.
HRRR IS PERFORMING WELL AS KEEPS THE AREA DRY UNTIL 08-09Z WHEN
A SHORTWAVE/VORT MAX ASSOCIATED WITH UPPER LOW MOVES TOWARDS THE
REGION. SHOWERS ASSOCIATED WITH THIS FEATURE ARE CURRENTLY OVER
THE DELMARVA PENINSULA AND ETA INTO THE SW PORTION OF THE AREA IS
CURRENTLY TIMED TO BE SLIGHTLY EARLIER (06-08Z) THAN THE HRRR IS
INDICATING. THEREFORE...WILL LEAVE INCREASING POPS AFTER 04Z AS
SCT SHOWERS MAY BEGIN TO DEVELOP AHEAD OF THE MAIN AREA. ALSO
REMOVED THUNDER FROM THE FORECAST TONIGHT WITH ONLY VERY WEAK
INSTABILITY EXPECTED TO BE PRESENT ALOFT.
THE ESE FLOW WILL VEER TO A MORE SOUTHERLY FLOW OVERNIGHT AS THE
OCCLUDED FRONT LIFTS NORTH OF THE AREA.
LOWS WILL RANGE FROM THE LOWER TO UPPER 50S. STAYED CLOSE TO MOS
GUIDANCE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
THE UPPER LOW TRACKS ACROSS THE AREA ON THU WITH STEEPENING LAPSE
RATES AND PLENTY OF INSTABILITY CLOUDS AND SHOWERS. THE BEST CHANCE
LOOKS TO BE IN THE MORNING WITH THE BEST LIFT AND DEEPEST
MOISTURE. RAINFALL AMOUNTS ARE EXPECTED TO BE LESS THAN ONE-
QUARTER INCH...HOWEVER ISOLATED HIGHER AMOUNTS ARE POSSIBLE WITH
ANY THUNDERSTORMS. THIS ACTIVITY SHOULD NOT BE AS ORGANIZED AS
THE CONVECTIVE BANDS THAT WENT THROUGH THE AREA ON WED.
HIGHS WILL TOP OUT IN THE LOWER 60S AT THE COAST...TO THE LOWER
70S NORTH AND WEST OF NYC. THIS IS CLOSE TO NORMAL. USED A BLEND
OF THE MOS GUIDANCE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WEAK DEEP-LAYERED RIDGING SHOULD KEEP US DRY FOR MOST OF THE DAY ON
FRIDAY...HOWEVER THERE COULD BE A LATE DAY THUNDERSTORM FROM AROUND
THE CITY AND POINTS WEST. BASED ON 850MB TEMPS...WENT CLOSER TO NAM
MOS HIGH TEMPERATURES...BUT LOWERED THEM BY A FEW DEGREES ALONG THE
SOUTH FACING SHORES.
A COLD FRONT SLOWLY APPROACHES FRIDAY NIGHT WITH A CHANCE OF A
SHOWER OR TSTM...HOWEVER SHOWERS AND POSSIBLE TSTMS LOOK TO
BE MOST LIKELY DURING SATURDAY AND SATURDAY NIGHT WITH THE FRONT
ENTERING THE AREA. BY DAYBREAK ON SUNDAY...THE FRONT IS MOST LIKELY
EAST OF THE CITY...SO JUST A LINGERING SHOWER POSSIBLE SUNDAY
MORNING. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT SUNDAY
AFTERNOON WITH CLEARING SKIES. HIGHS GENERALLY 70-75 ON SATURDAY AND
65-70 ON SUNDAY.
AN UPPER TROUGH SHIFTS INTO THE REGION ON MONDAY/MONDAY NIGHT.
PROBABLY JUST SOME DIURNAL CU BUILDUP...SO WILL KEEP THE FORECAST
DRY FOR NOW. HIGH TEMPS COLDER THAN NORMAL. THE TROUGH SHIFTS EAST
ON TUESDAY WITH MODERATING TEMPERATURES. WILL GO WITH A DRY FORECAST
ON WEDNESDAY FOR NOW...BUT MODELS DEPICT SOME MOISTURE SPILLING OVER
AN UPPER RIDGE TO THE WEST. MAY NEED TO EVENTUALLY INCLUDE CHANCES OF
SHOWERS FOR THIS PERIOD.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
SLOW MOVING LOW PRESSURE WILL MOVE THROUGH THE AREA THROUGH THURSDAY
WITH AN ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH OVERNIGHT.
STRATUS AND FOG HAS DEVELOPED ACROSS LONG ISLAND AND COASTAL
CONNECTICUT ...IFR TO LIFR...AND WILL BECOME MORE WIDESPREAD INTO
THE NEW YORK AREA TERMINALS AFTER 06Z. ANOTHER AREA OF RAIN IS
EXPECTED TO ROTATE INTO THE REGION AFTER 08Z AND CONDITIONS WILL
LIKELY IMPROVE A LITTLE.
AS THE LOW MOVES THROUGH THURSDAY PERIODS OF RAIN WILL BE LIKELY
WITH AN ISOLATED THUNDERSTORM ALSO POSSIBLE. AS THE LOW MOVES TO THE
NORTH OF THE AREA LATE IN THE FORECAST PERIOD...WINDS WILL BECOME
LIGHT FROM THE SOUTH AND SOUTHWEST.
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.THURSDAY NIGHT...IMPROVING CONDITIONS WITH SHOWERS ENDING.
.FRIDAY...CHANCE OF BRIEF MVFR OR LOWER CONDS IN ANY SCT SHOWERS IN
THE AFTERNOON. AN ISOLD TSTM POSSIBLE.
.FRIDAY NIGHT-SUNDAY MORNING...MVFR OR LOWER CONDS LIKELY IN ANY
SHOWERS... MAINLY THROUGH SUNDAY MORNING. AN ISOLD TSTM POSSIBLE SAT
AFTERNOON/EARLY EVENING
.SUNDAY AFTERNOON-MONDAY...VFR.
&&
.MARINE...
ISSUED A FOG ADVY FOR ALL WATERS BUT THE HARBOR WITH DEW POINT
DEPRESSIONS NEAR ZERO. OTHERWISE...SCA FOR HAZARDOUS SEAS REMAINS
IN EFFECT FOR THE OCEAN THROUGH THU. SEAS 4 TO 6 FT IN A SLY SWELL
BEGIN TO GRADUALLY SUBSIDE TO BELOW 5 FT BY THU EVENING. SEAS MAY
LINGER ABOVE 5 FT EAST OF MORICHES INLET FOR A PORTION OF THU
NIGHT.
SEAS REMAIN JUST BELOW SCA CRITERIA ON FRIDAY...THEN BUILD UP TO
5 FT FRIDAY NIGHT ON AN INCREASING SW FLOW. GUSTS ON THE OCEAN
WATERS COULD ALSO REACH 25 KT DURING THE DAYTIME ON SATURDAY AND
SATURDAY EVENING AHEAD OF AN APPROACHING COLD FRONT. WINDS AND
SEAS THEN DIMINISH ON SUNDAY AFTER THE PASSAGE OF THE COLD FRONT
WITH SEAS BELOW 5 FT PERHAPS BY THE END OF THE MORNING. AN
OFFSHORE FLOW THEN MAINTAINS SUB SCA CONDITIONS THROUGH MONDAY.
&&
.HYDROLOGY...
AN ADDITIONAL QUARTER INCH IS POSSIBLE THROUGH THU WITH ISOLATED
HIGHER AMOUNTS WITH ANY THUNDERSTORMS. THIS IN ASSOCIATION WITH
THE UPPER LOW TRACKING ACROSS THE AREA.
ANOTHER HALF INCH TO INCH OF RAINFALL IS POSSIBLE FROM LATE
FRIDAY THROUGH SUNDAY MORNING IN ASSOCIATION WITH A SLOWLY-MOVING
COLD FRONT. LOCALLY HIGHER AMOUNTS ARE POSSIBLE WITH
THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR CTZ010>012.
NY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NYZ078>081.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT THIS
EVENING FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...JMC/DW
SHORT TERM...DW
LONG TERM...JC
AVIATION...MET
MARINE...JMC/JC/DW
HYDROLOGY...JC/DW
AREA FORECAST DISCUSSION
NWS DES MOINES IA
351 AM CDT THU MAY 9 2013
.SHORT TERM.../TODAY /...
ISSUED AT 348 AM CDT THU MAY 9 2013
MAIN CONCERN THIS MORNING WILL BE CONVECTIVE TRENDS...ESPECIALLY
HEAVY RAIN POTENTIAL. COMPACT SHORT WAVE/PV ANOMALY CONTINUES TO
SLOWLY CROSS THE NE/IA BORDER. FORCING AHEAD OF FEATURE IS NOT
EXTREME...BUT COUPLED WEAK/MODERATE THERMODYNAMIC AND KINEMATIC
FORCING HAS SUSTAINED AND EVEN RECENTLY ENHANCED CONVECTION FROM SW
INTO CENTRAL IA. THIS IN SOME WAYS RESEMBLES A LOW END SHARS EVENT
BUT WITH LESS FAVORABLE ENVIRONMENT. SEVERE POTENTIAL HAS
DIMINISHED WITH NIL EFFECTIVE SHEAR AND MUCAPES ONLY SEVERAL HUNDRED
J/KG. HEAVY RAIN CONDITIONS ARE NOT GREAT EITHER WITH PWS JUST
OVER AN INCH AND WARM CLOUD DEPTHS UNDER 1K FT. HOWEVER MEAN CELL
MOTION IS CURRENTLY 230 AT ONLY 16KTS SO SUM ALL FACTORS TOGETHER
WITH SLOW MOVEMENT COULD STILL LEAD TO HEAVY RAINS WHICH
UNFORTUNATELY MAY IMPACT THE MORNING COMMUTE. ADAIR AND PERRY HAVE
ALREADY RECEIVED 1.7 INCHES SINCE MIDNIGHT. CONDITIONS CHANGE
LITTLE THROUGH THE MORNING WITH CATEGORICAL POPS...BUT OVERALL
FORCING DIMINISHES INTO THE AFTERNOON WITH LESS COVERAGE
ANTICIPATED. CANNOT ARGUE WITH 05Z HRRR DEPICTION TOO MUCH.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 348 AM CDT THU MAY 9 2013
WE WILL BE CONTINUING TO DEAL WITH THE REMNANTS OF THE SOUTH DAKOTA
LOW AND THE SOUTHERN STREAM SHORT WAVE PUSHING ACROSS THE FORECAST
AREA TONIGHT. THE SLOW MOVEMENT OF THE STORMS IN THE WEAK FLOW OVER
IOWA HAS PROVEN TO MAKE EFFICIENT RAIN PRODUCING STORMS BUT WE LOSE
WHATEVER WEAK FORCING WE HAD IN PLACE FROM TODAY SO I DON`T SEE AS
MUCH RAINFALL TONIGHT.
SOME LINGERING PRECIP EXPECTED ACROSS THE SOUTHEAST INTO FRIDAY
MORNING THEN A BREAK AS WEAK HIGH PRESSURE BUILDS IN AT THE SURFACE
WHILE ALOFT WE ARE IN BETWEEN SYSTEMS. FRIDAY NIGHT INTO SATURDAY A
LARGE LOW PRESSURE SYSTEM OVER CANADA CARVES A TROUGH INTO THE UPPER
MIDWEST. AT THE SURFACE A STRONG COLD FRONT WILL WORK ACROSS THE
AREA BRINGING A SHOT FOR MORE RAIN AND MUCH COLDER TEMPERATURES ALONG
WITH BREEZY CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL BE
DROPPING INTO THE LOW TO MID 30S SATURDAY NIGHT SO FROST HAS TO
ENTER THE THOUGHT PROCESS HERE BUT WINDS AT LEAST THROUGH THE
EVENING...AND PROBABLY ALL NIGHT ACROSS THE EAST...WILL STAY UP
ENOUGH TO MINIMIZE THE FROST THREAT. HOWEVER AT THIS POINT I THINK
IT IS ENOUGH OF A THREAT TO PUT IT IN THE FORECAST GRIDS ACROSS
NORTH FOR A FEW HOURS BEFORE DAYBREAK. THIS WILL NEED TO BE
MONITORED FOR THE POTENTIAL FOR MORE THAN JUST A MENTION.
THE COLD WILL BE SHORT LIVED AS A LARGE UPPER LEVEL RIDGE BUILDS
ACROSS THE ROCKIES THEN SHIFTS EAST EARLY NEXT WEEK. TUESDAY STILL
LOOKS VERY WARM AND WHILE I WAS NOT BOLD ENOUGH TO MENTION A 90
DEGREE READING I DID BUMP TEMPS UP INTO THE MID TO UPPER 80S. THE
UPPER RIDGE FLATTENS INTO MIDWEEK KNOCKING TEMPS BACK SEVERAL
DEGREES. A FRONTAL BOUNDARY WILL SAG INTO THE REGION PRODUCING A
CHANCE FOR THUNDERSTORMS TUESDAY NIGHT. TEMPERATURES THROUGH
MIDWEEK WHILE COOLER...WILL STILL BE SEASONAL INTO THURSDAY WITH
HIGHS IN THE 70S.
&&
.AVIATION...09/06Z
ISSUED AT 1159 PM CDT WED MAY 8 2013
AN AREA OF SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE NORTH
THROUGH 09Z THEN EXPECT A BAND OF FOG AND STRATUS TO DEVELOP WITH
IFR OR LOWER CONDITIONS POSSIBLE THROUGH MID MORNING. ANOTHER AREA
OF THUNDERSTORMS WILL LIFT INTO SOUTHERN IOWA OVERNIGHT AND
PRIMARILY IMPACT KOTM AND KDSM. AREAS OF PRECIPITATION WILL
CONTINUE ON THURSDAY BEFORE GRADUALLY DIMINISHING LATER IN THE
AFTERNOON AND EVENING. POTENTIAL FOR LOW STRATUS MOVING INTO THE
AREA BEHIND A FRONTAL BOUNDARY IS INCREASING BY THE EVENING AS
WELL.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...FAB
AVIATION...DONAVON
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1135 PM CDT WED MAY 8 2013
.UPDATE...
ISSUED AT 1130 PM CDT WED MAY 8 2013
UPDATED THE AVIATION SECTION FOR THE 06Z TAF ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM CDT WED MAY 8 2013
THE LATEST AVAILABLE HRRR OUTPUT DEVELOPS AT LEAST SCATTERED
CONVECTION AHEAD OF THE MCV MOVING OVER CENTRAL MISSOURI. STARTING
TO SEE SOME ENHANCEMENT ON VISIBILTY SATELLITE IMAGERY AND SOME
SHOWER DEVELOPMENT TO OUR WEST/NORTHWEST ON RADAR. DECIDED TO
INCREASE POPS UP TO LOWER CHANCE LEVELS COMING OUT OF THE OZARK
FOOTHILLS THROUGH SUNSET. THE HRRR DISSIPATES THE STRONGER
ELEMENTS AS THEY APROACH THE MISSISSIPPI RIVER AROUND 02Z.
FOLLOWED THE HRRR CLOSELY INTO THE EVENING...AND WILL HAVE A DRY
FORECAST BY 03Z. ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST
INDIANA AND THE PENNYRILE THIS AFTERNOON SHOULD DISSIPATE OR MOVE
SOUTH/EAST OF THE AREA BY SUNSET.
THE 12Z MODELS ARE TRENDING DRIER FOR LATER TONIGHT AND ESPECIALLY
THURSDAY. SOUNDINGS INDICATE THAT A WEAK CAP WILL BE SUFFICIENT TO
KEEP MOST AREAS DRY...DUE TO A GENERAL LACK OF DEEP MOISTURE OR
MAJOR FORCING. WILL SPREAD GOOD CHANCE POPS EASTWARD ALONG THE
I-64 CORRIDOR THROUGH THE MORNING AND KEEP THEM AT THAT LEVEL THERE
THROUGH THE AFTERNOON AND INTO THE EVENING. THIS AREA WILL BE
CLOSEST TO ANY EFFECTS OF MID/UPPER LEVEL DISTURBANCES AND THE
FRONT ITSELF. WOULD BE VERY SURPRISED TO SEE ANYTHING MORE THAN A
VERY ISOLATED STORM PULSE UP TO NEAR SEVERE LEVELS ALONG I-64
THURSDAY AFTERNOON. WILL KEEP SLIGHT CHANCES TO THE SOUTH JUST IN
CASE WE DESTABILIZE ENOUGH FOR A PARCEL TO BREAK THROUGH DURING
THE AFTERNOON.
THURSDAY WILL SEE INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS...AS THE COLD FRONT AND IMPACTS OF THE PRIMARY
MID/UPPER LEVEL DISTURBANCE APPROACH THE AREA. THE LLJ WILL
INCREASE TO AROUND 35KTS...WHICH SHOULD HELP TO BRING SOME
BETTER...DEEPER MOISTURE NORTHEAST ACROSS MUCH OF THE AREA. WILL
HAVE A SOUTHWEST TO NORTHEAST BAND OF LIKELY POPS OVER SOUTHEAST
MISSOURI AND SOUTHERN ILLINOIS LATE IN THE EVENING...AND THEN MOVE
IT SLOWLY EASTWARD ACROSS THE REMAINDER OF THE AREA OVERNIGHT.
THE MODELS SEEM TO HAVE CONVERGED FOR FRIDAY. A WEAK COLD FRONT
WILL SLOWLY PUSH EASTWARD ACROSS THE AREA THROUGH THE DAY AND
SHOULD CLEAR THE ENTIRE AREA BY EARLY EVENING. WITH THE FRONT AND
THE MAIN MID/UPPER DISTURBANCE OVER THE AREA FRIDAY...LIKELY POPS
SEEM WARRANTED...WITH AN EMPHASIS OVER WEST KENTUCKY. A LACK OF
FORCING...ONLY WEAK INSTABILITY...AND GENERALLY WEAK WIND PROFILES
SHOULD KEEP ANY CONVECTION WELL BELOW SEVERE LIMITS. SOME VERY
LOCALIZED HEAVY RAINFALL SHOULD BE THE PRIMARY CONCERN FRIDAY.
POPS WILL LINGER INTO FRIDAY EVENING...MAINLY IN THE EAST...BUT
THE MODEL CONSENSUS IS FOR THE ENTIRE AREA TO BE DRY BY 06Z SATURDAY.
AS FOR TEMPERATURES...WENT ON HIGH END OF GUIDANCE FOR HIGHS
THURSDAY...AND TOWARD THE COOL SIDE FRIDAY. WENT A BIT ABOVE
GUIDANCE FOR LOWS FRIDAY NIGHT. OTHERWISE...CONSENSUS OF GUIDANCE
SHOULD BE FINE.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM CDT WED MAY 8 2013
OVER THE WEEKEND...A CLOSED LOW OVER ONTARIO AT THE START OF THE
PERIOD...MOVES EAST AND ENDS UP CARVING A DEEP TROUGH OVER THE GREAT
LAKES AND DOWN INTO OUR REGION. A SECONDARY FRONT MOVES SOUTH TOWARD
US ON SATURDAY AND WHILE IT SEEMS TO START OUT WITH ENOUGH MOISTURE
TO OUR NORTH...BY THE TIME THE FRONT GETS HERE SATURDAY
EVENING...NOT MUCH MOISTURE IS LEFT. SO OPTED TO REMOVE ALL POPS FOR
SATURDAY.
BEHIND THE SECONDARY COLD FRONT...MUCH COOLER AIR WILL FILTER INTO
THE AREA SATURDAY NIGHT AND INTO SUNDAY...ON THE NOSE OF SFC HIGH
PRESSURE FROM CANADA. THE 00Z/12Z ECMWF AND 06Z/12Z GFS INDICATE
850MB TEMPS AT OR BELOW ZERO IN OUR FAR NORTHERN COUNTIES.
HOWEVER...SINCE HIGH PRESSURE WILL STILL BE MOVING IN...THE WIND
WILL LIKELY STAY UP WHICH WILL PREVENT US FROM DROPPING TOO LOW ON
OUR LOW TEMPS FOR SATURDAY NIGHT.
THE SFC HIGH WILL FINALLY BEGIN TO SETTLE OVER THE AREA ON SUNDAY
AND SUNDAY NIGHT...WITH ALL INDICATIONS THAT THE CENTER OF THE HIGH
WILL BE DIRECTLY OVER US ON 12Z MONDAY. WITH COLD AIR ADVECTION IN
FULL SWING ON SUNDAY...WOULD VENTURE TO GUESS WE WILL NOT GET OUT OF
THE 60S FOR HIGHS. THE COLDEST AIR WILL BE SITUATED OVER OUR
NORTHEASTERN COUNTIES (NAMELY SE IL...SWIN...PENNYRILE). LOOKING AT
CIPS ANALOG DATA ALONG WITH RECORDS FROM XMACIS...WE COULD BE
LOOKING AT LOWS SUNDAY NIGHT FALLING INTO THE UPPER 30S FOR THESE
PORTIONS OF OUR AREA IF THE GFS IS CORRECT. 850 MB TEMPS OFF THE GFS
AND THE GFS ENSEMBLE MEAN ARE A BIT COOLER THAN THE ECMWF...AND WITH
CALM WINDS AND CLEAR SKIES...WE COULD DROP QUITE A BIT. LOOKING AT
RAW MODEL DEWPOINT TEMPS...THIS ALSO SUPPORTS THESE COOLER
TEMPS...WHICH COULD GET CLOSE TO TYING RECORDS IN THE EVV AREA.
ELSEWHERE THOUGH...IT STILL LOOKS COOL WITH LOWS IN THE LOWER 40S.
AGAIN...THIS MAY BE COLD ENOUGH TO SUPPORT THE FORMATION OF VERY
PATCHY FROST IN OUTLYING AREAS...BUT A WIDESPREAD FROST IS STILL NOT
ANTICIPATED ATTM.
THE SFC HIGH MOVES EAST AND EVENTUALLY SOUTH ON MONDAY/MONDAY NIGHT AND
THAT IS WHEN THE WARM UP WILL BEGIN. DEPENDING ON HOW LOW WE START
THE DAY WITH ON MONDAY...WE WILL STILL BE COOL WITH HIGHS REMAINING
IN THE 60S/POSSIBLY AROUND 70 FAR WEST. THE FLOW IN THE LOW LEVELS
BECOMES SOUTHERLY/SOUTHWESTERLY LATE MONDAY NIGHT INTO TUESDAY AND
850 MB TEMPS WILL RISE STEADILY FROM THEN THROUGH THE END OF THE
EXTENDED PERIOD (WEDNESDAY). THEREFORE...WE EXPECT HIGHS IN THE 70S
ON TUESDAY WITH AROUND 80 ON WEDNESDAY. THIS EARLY WEEK PERIOD
CONTINUES TO BE DRY. LOOKING BEYOND THAT...MODELS TRY TO BRING A
FRONT INTO THE AREA BUT DIFFER ON TIMING.
&&
.AVIATION...
ISSUED AT 1130 PM CDT WED MAY 8 2013
VFR CONDITIONS EXPECTED AT ALL SITES THROUGH THE PERIOD. CHANCE
OF VCTS AT ALL SITES STARTING AT 00Z. VARIABLE WINDS AOB 5 KTS
WILL PICK UP OUT OF THE SOUTH AT 10-15KTS WITH GUSTS OF 15-24 KTS
AFT 15Z...THEN DIMINISH TO AOB 10 KTS AFT 00Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...JP
PUBLIC...DB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 AM EDT THU MAY 9 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 408 PM EDT WED MAY 8 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS STILL SHOW BLOCKY FLOW
DOMINATING THE CONUS TO THE S OF PROGRESSIVE BUT GRADUALLY
AMPLIFYING FLOW ACROSS CANADA. IN THE BLOCKY CONUS FLOW...MID LEVEL
LOWS ARE LOCATED OVER THE SOUTHERN ROCKIES...ERN SD AND THE MID
ATLANTIC STATES. TO THE N...FLOW ACROSS CANADA HAS AMPLIFIED SOME IN
THE LAST COUPLE OF DAYS AS TROFFING IS NOSING S THRU MANITOBA/NRN
ONTARIO. MUCH STRONGER AMPLIFICATION WILL FOLLOW THIS WEEKEND AS
SHARP TROFFING DEVELOPS S INTO THE GREAT LAKES. COLD FRONT
ASSOCIATED WITH SHORTWAVE THAT MOVED FROM MANITOBA YESTERDAY TO
QUEBEC TODAY IS JUST NW AND N OF LAKE SUPERIOR. AHEAD OF THE
FRONT...IT HAS BEEN ANOTHER WARM DAY ACROSS UPPER MI. SOME LOCATIONS
ALONG LAKE SUPERIOR HAVE EXPERIENCED A MUCH WARMER DAY TODAY AS LAKE
BREEZE DID NOT DEVELOP AS EARLY AS IN PREVIOUS DAYS...AND IT IS
WEAKER. DESPITE ONSHORE WINDS ALONG LAKE MI...COOLING THERE HAS ONCE
AGAIN BEEN WEAK. INLAND...TEMPS HAVE SOARED THRU THE 70S WITH A FEW
SPOTS REACHING 80F. VERY DRY AIR STILL LINGERS OVER A GOOD PORTION
OF UPPER MI (NOTE THE VERY DRY COLUMN AGAIN SAMPLED BY THE 12Z KGRB
SOUNDING). AS A RESULT...DWPTS HAVE CRASHED DOWN AS LOW AS THE UPPER
20S/LWR 30S ACROSS PORTIONS OF MAINLY CNTRL/ERN UPPER MI. RH IS IN
THE 15-25PCT RANGE AT MOST LOCATIONS. FORTUNATELY...WINDS REMAIN
LIGHT...KEEPING FIRE WX CONCERNS IN CHECK FROM WHERE THEY COULD BE
ON A DAY LIKE THIS. SOME OF THE MID LEVEL MOISTURE NOTED ON PREVIOUS
DAYS SOUNDINGS FROM KINL/KMPX HAS ADVECTED INTO UPPER MI TODAY AND
MADE ITS PRESENCE KNOWN WITH POCKETS OF SCT/BKN MID CLOUDS EARLIER
IN THE DAY. DAYTIME HEATING HAS NOW LED TO VERY HIGH BASED CU
DEVELOPING OVER MUCH OF UPPER MI. A FEW RADAR RETURNS HAVE APPEARED
ON KMQT RADAR IMAGERY OVER WRN UPPER MI...BUT DRY LOW-LEVEL AIR HAS
PROBABLY PREVENTED ANY PCPN OR AT LEAST NOTHING MORE THAN A FEW
SPRINKLES FROM REACHING THE GROUND.
COLD FRONT TO THE N WILL DROP S...PASSING ACROSS UPPER MI
TONIGHT/EARLY THU MORNING. LOW-LEVEL DRY AIR WILL CONTINUE TO BE A
PROBLEM DUE TO LITTLE ADVECTION OF ANY MOISTURE AT THE LOW-LEVELS.
EVEN UPSTREAM...KINL/KMPX SOUNDINGS SHOW THAT LOW-LEVELS THERE HAVE
BEEN DRYING OUT OVER THE LAST DAY OR TWO...BUT THERE IS STILL
SUFFICIENT MOISTURE FOR SCT SHRA AND EVEN A FEW TSRA OVER NRN MN
INTO NW WI THIS AFTN. AS MID LEVEL LOW OVER ERN SD DRIFTS E...IT MAY
HELP PUSH BETTER MOISTURE INTO THE FRONTAL BOUNDARY THAT IS DROPPING
OVER THE AREA. HOWEVER...GIVEN THE LOW-LEVEL WIND FLOW/LACK OF
MOISTURE ADVECTION...PREFER THE GEM/ECMWF/UKMET AND TO SOME DEGREE
THE NAM IDEA OF MAINTAINING THE LOW-LEVEL DRY AIR OVER THE AREA
TONIGHT. AS A RESULT...WILL ONLY INCLUDE SCHC/LOW CHC POPS OVER THE
NW PORTION OF THE FCST AREA.
WITH MID LEVEL LOW OPENING UP/WEAKENING AS IT TRACKS E THU...IT
PROBABLY WON`T BE ABLE TO BRING A GOOD PUSH OF MOISTURE N OF THE
COLD FRONT THAT PASSED THRU THE AREA. HOWEVER...THERE ARE
INDICATIONS THAT MID LEVEL FGEN WILL INCREASE ACROSS THE UPPER
LAKES. WITH COLD FRONT SLIPPING S OF THE FCST AREA IN THE
MORNING...THERE WILL BE A BETTER OPPORTUNITY FOR LOW-LEVELS TO
MOISTEN IN THE COOLER AIR MASS UNDERNEATH THE FGEN FORCING...AND
THIS SHOULD PROVIDE AT LEAST A CHANCE OF SHRA OVER MUCH OF THE AREA
THU. WILL PAINT MAINLY THE WRN FCST AREA FOR BEST CHC OF SHRA AS
THERE ARE HINTS OF LOW-LEVEL DRY AIR STILL LINGERING OVER THE E.
WITH CAA AND MORE CLOUDS...IT WILL BE A COOLER DAY...ESPECIALLY NEAR
LAKE SUPERIOR DUE TO GRADIENT FLOW ACROSS THE LAKE (TEMPS ALONG THE
LAKE WILL PROBABLY ONLY BE IN THE LOW/MID 40S THRU THE DAY). ACROSS
THE SCNTRL AND E...TEMPS MAY STILL REACH THE MID 60S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT WED MAY 8 2013
UPPER FLOW GOES THROUGH A TRANSITION DURING THE LONG TERM PERIOD.
INITIALLY ON THURSDAY NIGHT FLOW IS MORE ZONAL WITH BROAD SHALLOW
TROUGH OVER MOST OF CANADA. LATER FRIDAY TRHOUGH SATURDAY...EXPECT
SHARP AMPLIFICATION AS TROUGH CURRENTLY NORTH OF ALASKA BARRELS
ACROSS CANADIAN PRAIRIES AND ONTARIO. PRIMARY COLD FRONT SWINGS
ACROSS UPPER MICHIGAN FRIDAY NIGHT INTO SATURDAY MORNING WITH
PARENT SFC LOW REACHING CENTRAL QUEBEC BY SUNDAY MORNING. MODELS
HAVE TRENDED FARTHER EAST WITH UPPER LOW CENTER AND QUICKER WITH
FRONTAL PASSAGE. TROUGH ALOFT SLOWLY MOVES INTO EASTERN CANADA ON
MONDAY WITH STRONG RIDGE AND WARM AIR EXPANDING TOWARD CENTRAL
CANADA AND THE PLAINS. TAIL END OF EXTENDED FEATURES WARMING TREND
OVER UPPER LAKES AS RIDGING MOVES FARTHER EAST. MAY SEE BREEZY
CONDITIONS ACCOMPANYING THE WARM UP AS STRONG LOW PRESSURE MOVES
FROM MANITOBA TO NORTHWEST ONTARIO.
SHALLOW COOL AIR SLOWLY FILTERS ACROSS UPR MICHIGAN LATER THURSDAY
AND THURSDAY EVENING. STILL A POTENTIAL OF RAIN THURSDAY EVENING
WITH LINGERING H7-H5 MOISTURE/LIFT DUE TO H7-H6 FRONTOGENESIS. NAM
AND GFS MORE BULLISH ON QPF OVER CWA COMPARED TO ECMWF AND GEM-NH.
THINKING NAM IDEA IS TOO FAR WEST WITH PRECIPITATION BAND...BUT
WILL KEEP SMALL POPS OVER SOUTH AND EAST THROUGH 03Z FRIDAY. REST
OF THURSDAY NIGHT INTO FRIDAY LOOKING QUIET OUT AHEAD OF THE STRONG
COLD FRONT. ONE CONCERN COULD BE STRONGER EAST-NORTHEAST WINDS OVER
EASTERN CWA THURSDAY NIGHT INTO FRIDAY MORNING...ESPECIALLY IF NOT
MUCH RAIN OCCURS THERE AND HUMIDITY RECOVERIES ARE POOR THURSDAY
NIGHT. GRADIENT WINDS DIMINISH THROUGH THE DAY ON FRIDAY...BUT AS
BUBBLE HIGH AT 1025MB BUILDS OVER LK SUPERIOR...NORTH WINDS COULD
STAY GUSTY INTO MID AFTN FROM COPPER HARBOR TO MARQUETTE AND GRAND
MARAIS. VERY DRY CONDITIONS AS H85 DWPNTS ARE DOWN TO AROUND -30C.
GIVEN SUCH DRY AIRMASS...EXPECT MIXED LAYER DWPNTS TO MIX OUT AWAY
FROM IMMEDIATE LK SUPERIOR SHORE AS LOW AS MID-UPPER TEENS IN THE
AFTN. EVEN WITH MUCH COOLER TEMPERATURES...ONLY AS WARM AS THE UPPER
50S INLAND...LOW DWPNTS WILL RESULT IN HUMIDITY VALUES BLO 25 PCT
IN AFTERNOON. BASED ON SOUNDINGS...DRY AIRMASS HANGS ON THROUGH
FRIDAY EVENING OVER ALL CWA.
FOCUS THEN IS ON STRONG COLD FRONTAL PASSAGE BY SATURDAY. 1000-500MB
THICKNESS PACKING FROM ECMWF/GFS/NAM INDICATE FRONTAL PASSAGE AFTER
MIDNIGHT FRIDAY NIGHT OVER FAR WEST CWA AND EARLY SATURDAY AFTERNOON
OVER THE FAR EASTERN CWA. SOUNDINGS SHOW MOISTURE BUILDING DOWN FROM
MID-LEVELS...RESULTING IN ONLY A FEW HOURS OF SATURATION FOR SOME
SHOWERS BEFORE DRYING AND SUBSIDENCE KICK IN BEFORE DAYBREAK OVER
WESTERN CWA AND BY MID MORNING OVER EASTERN CWA. WITH THE INITIAL
BATCH OF SHOWERS...LOOKS LIKE IT REMAINS TOO WARM BLO H9 TO HAVE
SNOW MIX IN WITH THE RAIN. 06Z NAM SHOWED ENOUGH COLD AIR WORKING
IN JUST AS PRECIP ENDED AT ERY FOR SOME SNOW SATURDAY MORNING. 12Z
RUN KEEPS IT ALL LIQUID. UNCERTAIN HOW MUCH MOISTURE IS AROUND ON
SATURDAY...BUT THAT WILL HAVE BEARING ON HOW MUCH PRECIP OCCURS AND
WHETHER THERE WILL BE ANY SNOW OR MIXED RAIN AND SNOW. THINKING THAT
NAM MAY BE OVERDONE WITH EXTENT OF SUBSIDENCE/DRYING OR AT THE LEAST
THE EXTENT/DURATION OF DRYING ON SATURDAY. GFS/ECMWF POINT TO CHANCE
OF MORE DIURNAL/COLD POOL TYPE SHOWERS AS TOTAL TOTALS PUSH 50 AND
WITH INCREASING H85-H7 RH. SHOULD SEE LOTS OF CLOUDS AND WILL GO
WITH LOW CHANCES FOR SHOWERS MOST AREAS. GIVEN ENOUGH MOISTURE AS
GFS/ECMWF INDICATE...WET BULB BLO ZERO THROUGH THE DEPTH OF THE
COLUMN WOULD SUPPORT AT LEAST A MIX OF RAIN AND SNOW OVER THE WEST
HALF. MAX TEMPS IN UPPER 30S TO LOWER 40S AT THE COOLEST WILL NOT
ALLOW FOR ANY APPRECIABLE SNOW ACCUMS THOUGH THERE COULD BE BRIEF
REDUCED VSBY IN THE HEAVIEST SNOW SHOWERS. OTHER ISSUE ON SATURDAY
WILL BE STRONG/GUSTY WINDS. SOUNDINGS INDICATE UNIDIRECTIONAL WNW
30-40 KT MIXED LAYER WINDS. PORTION OF THESE WINDS WILL MIX DOWN IN
GUSTS DUE TO MECHANICAL MIXING AND COLD AIR ADVECTION. EXPECT
STRONGEST WINDS OVER 40 MPH ON THE KEWEENAW PENINSULA...WITH GUSTS
OVER 30 MPH ELSEWHERE.
DRYING TREND TAKES OVER SUNDAY INTO MONDAY AS THE LARGER SCALE
TROUGH DEPARTS THE AREA. STILL COOL FOR SUNDAY WITH SIMILAR
READINGS TO SATURDAY. QUITE CHILLY SUNDAY NIGHT WITH MANY AREAS
FALLING BLO FREEZING WITH PWAT LESS THAN 50 PCT OF NORMAL AS SFC
HIGH PRESSURE RIDGE MOVES ACROSS.
REST OF EXTENDED FEATURES WARMING TREND AS RIDGE OVER PLAINS BUILDS
ACROSS. ELEVATED MOISTURE AND INSTABILITY WITH THE WARM AIR ADVECTION
MAY TRIGGER SCT SHOWERS/TSRA TUESDAY. CHANCES FOR WIDESPREAD PRECIP
SEEM LOW THOUGH AS PRIMARY LARGE SCALE LIFT STAYS OVER ONTARIO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 132 AM EDT THU MAY 9 2013
EXPECT VFR CONDITIONS THROUGH EARLY THU MORNING AT KIWD/KCMX/KSAW AS
LOW-LEVELS REMAIN VERY DRY. THU MORNING...STRENGTHENING CHILLY N/NE
FLOW AND INCREASING POTENTIAL OF -SHRA MAY RESULT IN A LOW
STRATOCU/STRATUS DECK DEVELOPING AT ALL THE SITES WITH MVFR CIGS
DEVELOPING. UPSLOPE COMPONENT AT IWD AND SAW WILL KEEP THE CIGS IN
THROUGH EARLY THU EVENING EXCEPT AT SAW WHERE THE MOIST UPSLOPE NE
FLOW WILL KEEP THE MVFR CIG IN THROUGH THU EVENING. AT CMX...DRY
AIR WILL COME BACK IN LATE THU AFTERNOON AND CONDITIONS WILL GO BACK
TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT WED MAY 8 2013
LIGHT WINDS WILL PERSIST INTO THE EVENING. THEN...FOLLOWING THE
PASSAGE OF A COLD FRONT TONIGHT...NNE WINDS WILL INCREASE UP TO
15-25KT LATE TONIGHT THRU THU NIGHT. THE ARRIVAL OF ANOTHER HIGH
PRES RIDGE WILL THEN CAUSE WINDS TO DIMINISH FRI. A STRONGER COLD
FRONT WILL SLIDE ACROSS THE UPPER LAKES FRI NIGHT AND SHIFT WINDS TO
THE NW AT 20-30KT FOR SAT. GIVEN TIGHT PRES GRADIENT AND STRENGTH OF
CAA...GALE FORCE GUSTS WILL LIKELY OCCUR. WINDS WILL THEN DIMINISH W
TO E SUN AS HIGH PRES RIDGE ARRIVES. WINDS SHOULD BE UNDER 15KT
LATER SUN NIGHT THRU MON.
&&
.HYDROLOGY...
ISSUED AT 408 PM EDT WED MAY 8 2013
WARM TEMPS CONTINUE TO MELT LINGERING SN PACK OVER THE HIER TERRAIN
OF THE W AND NCENTRAL. RUNOFF INTO THE MONTREAL RIVER AND ISOLD
FLOODING ALONG THE WISCONSIN AND MICHIGAN BORDER IN WESTERN GOGEBIC
COUNTY NEAR IRONWOOD PROMPTED EVENING SHIFT ON TUESDAY TO ISSUE
AREAL FLOOD ADVISORY FOR GOGEBIC COUNTY. THIS MATCHES UP WITH FLOOD
ADVISORY OUT FOR IRON COUNTY WISCONSIN ISSUED BY WFO DULUTH. PLAN TO
LET WFO MARQUETTE ADVY EXPIRE AS SCHEDULED AS NO OTHER FLOODING HAS
BEEN REPORTED.
OTHERWISE...MOST AREA STREAMS/RIVERS CONTINUE TO REMAIN STEADY OR
SHOW SLOW DECLINE WITH RECENT DRY WX. WITH MINIMAL PRECIP IN THE
FORECAST IN THE COMING DAYS AND BULK OF SNOW PACK GONE EXCEPT OVER
THE HIGHER TERRAIN OF THE KEWEENAW/NCENTRAL...SUSPECT THESE TRENDS
WILL CONTINUE. RIVER ADVISORIES OR FLOOD WARNINGS CONTINUE FOR THE
TRAP ROCK RIVER AT LAKE LINDEN...THE STURGEON RIVER AT ALSTON AND
CHASSELL...AND THE MICHIGAMME RIVER AT WITCH LAKE AND REPUBLIC. FOR
COMPLETE DETAILS...SEE THE LATEST PRODCUTS FOR THESE RIVER FLOOD
WARNINGS AND ADVISORIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...07
MARINE...ROLFSON
HYDROLOGY...JLA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
357 AM CDT Thu May 9 2013
.SHORT TERM...(Today through Saturday Afternoon)
Issued at 350 AM CDT THU MAY 9 2013
Conditions remain quiet early this morning as strong isentropic
lift and a veered LLJ have driven showers and thunderstorms into far
northeastern Missouri and southern Iowa. Regional radar and WV
imagery depict several developed MCV this morning, one located over
north central Kansas with two additional waves over northern and
eastern Oklahoma.
Through daybreak, short term guidance is in agreement that most of
the area will remain quiet as the vort max over north central Kansas
tracks northeast through the northwestern corner of Missouri. Have
lowered PoPs in most locations through daybreak. The stronger
southern MCV is now beginning to turn to the east as it enters
eastern Oklahoma. HRRR/RAP have struggled with this second wave, but
feel it will track into southern Missouri and gradually turn northeast
towards St. Louis after daybreak, perhaps tracking a little further
south than HRRR suggests.
Today: Subsidence in the wake of the MCV will prevent much in the
way of activity during the morning hours, and we may actually see
clouds scatter by late morning as a stationary boundary remains
draped over eastern Kansas and the northwestern third of Missouri.
Soundings indicate very low convective temperatures today, and by
late morning, we may already be approaching 70 in many areas.
Subsidence behind the departing wave will only last so long, as
stronger upper troughing remains over western Kansas. MLCAPE values
only approach 800-1000 J/KG, and shear remains marginal, thus only
anticipating a few small hail producing storms. The degree of heating
in the southeastern zones remains more questionable given the track
of the southern KS MCV this morning. Additional cloud cover and
stronger subsidence behind this wave in central Missouri may prevent
widespread redevelopment.
Thursday night-Friday: Surface troughing will push southeast
Thursday evening as upper troughing to the west begins to pivot
eastward and colder air aloft spills southward. Weak mid-level
frontogenesis may produce some lingering showers through the
overnight hours of Thursday. A north wind will prevail on Friday as
the front continues to push into southeastern Missouri and the upper
trough pivots overhead. Have lowered high temperatures a few degrees
due to the cloudy conditions and cold air advection aloft.
Temperatures may need to be lowered further in some areas.
Saturday: Weak surface ridging will slide through the area Friday
night before a much stronger cold front arrives on Saturday. Winds
will quickly turn northwest by late Saturday afternoon, turning
blustery. Temperatures will struggle to reach the lower 60s.
.LONG TERM...(Saturday Evening through Wednesday)
Issued at 350 AM CDT THU MAY 9 2013
Sunday - Tuesday:
This period will be characterized by dry weather an a marked warming
trend. Canadian high pressure will settle over the area by Sunday
morning making for a very cool start to the day. We will even flirt
with record lows (record low at MCI is 39 set in 1997). By Sunday
afternoon 850mb temps are only 2-6C which will yield highs only in
the upper 50s to lower 60s. On Monday upper level ridging that was
over the western Rockies on Sunday will begin to shift eastward into
the eastern Rockies and western Plains. This will provide for height
rises across the area. Couple that with surface high pressure
pushing off to the southeast and allowing for a return to southerly
flow and highs will rise into the upper 60s to mid 70s. By Tuesday
the upper level ridge axis moves over head. 850mb temperatures will
rise to 16-20C. And, with strong southwesterly winds providing for
good mixing, highs will be some of the warmest we have experienced
this season with highs in the low to mid 80s.
Wednesday:
Wednesday the upper level ridge will be shunted to the southeast as
an upper level trough digs into the Upper Midwest. This will send a
weak cold front into the area which will provide the next chance of
showers and thunderstorms. There is some question as to how much
moisture this system will have as the EC has a surface high pressure
over the Gulf Coast states keeping the Gulf closed. The GFS has high
pressure over the eastern Gulf with the western Gulf open and
moisture being transported into the area. Have maintained chance
POPs inherited by the initialization to account for the GFS solution.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1212 AM CDT THU MAY 9 2013
Going to be an active night with periods of showers and
thunderstorms through mid Thursday morning. However, ceilings will
remain in the low end VFR range for the most part. Could have a very
brief period of MVFR ceilings with any heavier cell. The convective
complex that will affect the terminals overnight should move out by
mid/late morning and bring an end to most of the rain. There will
likely still be isolated to scattered lingering showers into the
afternoon hours.
A weak cold front will finally slide southeast through the terminals
during the afternoon and early evening hours. Could see MVFR ceilings
be drawn into the terminals within the post frontal airmass with
scattered showers also a possibility.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...31
LONG TERM...73
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1148 PM CDT WED MAY 8 2013
.AVIATION...06Z TAFS FOR KOFK...KLNK AND KOMA.
SHORT TERM AVN CONCERNS STILL ARE STILL ISOLD -TSRA ALONG AND
SOUTH OF I-80...THUS AFFECTING KOMA AND KLNK. EXPECT CELLS TO DIE
OFF THOUGH OVER THE COUPLE HOURS. HOWEVER...TSRA WILL INCREASE IN
AREAL COVERAGE ALONG THE NEB/KS BORDER THRU TONIGHT. DO NOT
BELIEVE THAT ACTIVITY WILL MAKE MUCH OF A PUSH NWD...THUS SPARING
KOMA/KLNK FROM ANY FURTHER STORMS. NEXT ISSUE IS DETERIORATING
CONDITIONS REST OF TONIGHT. LATEST OBS SHOWING MVFR COND
BEGINNING TO SETTLE IN OVER ERN NEB...AND EXPECT TREND TO CONTINUE.
WITH INFLUX OF LLVL MOISTURE...EXPECT MVFR/IFR CONDITIONS WILL
PREVAIL THRU AT LEAST 09/14Z...THEN VFR CIGS FL050 AGL GENERALLY
PREVAILING THE REMAINDER OF THE FCST PD.
DEE
PREV DISCUSSION... /ISSUED 258 PM CDT WED MAY 8 2013/
DISCUSSION...
PRECIPITATION CHANCES TONIGHT INTO THURSDAY MAIN FORECAST FOCUS IN
THE SHORTER TERM. EXTENDED FORECAST WILL DEAL WITH A RELATIVELY
BRIEF BUT SUBSTANTIAL COOLDOWN THIS WEEKEND...FOLLOWED BY A MUCH
WARMER PATTERN NEXT WEEK.
AFTERNOON SATELLITE IMAGERY SHOWED A COMPACT UPPER CIRC CENTER
PIVOTING TOWARD NERN NEBR WITH ANOTHER UPPER WAVE MOVG INTO ERN
KS. REMNANT SHOWER ACTIVITY ON A LOBE MOVING AROUND SD UPPER LOW
WAS MOVG TOWARD FAR ERN ZONES AS OF 19Z...WITH SCATTERED
CONVECTION DEVELOPING NEAR THERMAL BOUNDARY BETWEEN PRECIP COOLED
AIR AND LOCATIONS WHICH HAD CLEARED UNDER UPPER THERMAL TROUGH IN
NERN NEBR. WOULD EXPECTED SCATTERED CONVECTION NERN ZONES INTO AT
LEAST EARLY THIS EVENING. ANOTHER AREA WHERE ACTIVITY COULD BE
MORE WIDESPREAD...ESPECIALLY EARLY THIS EVENING...WOULD APPEAR TO
BE NEAR WARM FRONT WHICH HAD LIFTED INTO FAR SRN NEBR. IN FACT
EVEN IF CURRENT ACTIVITY DVLPG NEAR SRN NEBR BOUNDARY DECREASES
EARLY THIS EVENING...WE COULD SEE ADDITIONAL DEVELOPMENT LATE THIS
EVENING AS SUGGESTED BY THE HRRR AND 4KM WRF AS LOW LEVEL JET
STRENGTHENS SOUTH OF BOUNDARY. THE LATTER MODEL EVEN SUGGESTED
NERN NEBR ACTIVITY WOULD BEGIN TURNING SE LATER THIS EVENING
MEETING UP WITH ANY CONVECTION THAT WOULD INCREASE IN SERN NEBR
LATE THIS EVENING. GENERALLY INCREASED POPS MOST AREAS EARLY
TONIGHT AND LATEST TRENDS WILL CONTINUE TO BE MONITORED FOR LAST
MINUTE CHANGES TO 00Z-03Z PD. AS UPPER LOW OVR SD BEGINS OPENING
UP/DROPPING SE LATE TONIGHT...SOME LIGHT SHOWERS COULD MOVE BACK
INTO NERN NEBR TOWARD THU MORNING WITH A CONTINUED SOUTHWARD PUSH
OF THESE GENERALLY LIGHT SHOWERS THURSDAY MORNING. IN
ADDITION...HEATING AND UPPER LOW REMNANTS ON THURSDAY COULD BRING
SCATTERED SHOWERS/TSTMS JUST ABOUT ANYWHERE THURSDAY AFTN AND SOME
POPS WERE ADDED ALL ZONES. GFS/NAM LINGERED QUITE A BIT OF LOW
LEVEL MOISTURE ACROSS MUCH OF THE FORECAST AREA ON THURSDAY WHICH
COULD LIMIT THIS HEATING AND COULD PROVIDE A PSBL NEGATIVE.
FOR NOW FORECAST WAS KEPT DRY THURSDAY NIGHT ALTHOUGH COULD SEE A
LINGERING LIGHT SHOWER/ISOLD TSTM EARLY. CLEARING THEN EXPECTED
FRIDAY WITH RELATIVELY LIGHT WINDS AND SEASONAL OR SLIGHTLY COOLER
TEMPERATURES. A STRONG COLD FRONT STILL ON TRACK TO RACE ACROSS
THE AREA FRIDAY NIGHT WITH GUSTY WINDS AND COOLER READINGS
ON SATURDAY. MAINTAINED SMALL POPS WITH FRONTS PASSAGE NRN ZONES
FRI NIGHT BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ANY CHCS
FARTHER SOUTH. GUSTY NRLY WINDS LIKELY SATURDAY AS SUB-ZERO H85
AIR MOVES INTO NRN ZONES EARLY IN THE DAY BEFORE MODERATING.
AIRMASS IS COOL/DRY ENOUGH SO THAT WITH DECREASING WINDS SAT NIGHT
SEE NO REASON LOWS WON/T GET AT LEAST AS COOL AS LATEST MEX MOST
AREAS. THIS COULD LEAD TO SCATTERED FROST SUNDAY MORNING IF DWPTS
DON/T DRY OUT TOO MUCH. NO FROST WAS MENTIONED AT THIS TIME...BUT
IT IS CERTAINLY POSSIBLE.
WARMING TREND STILL ON TRACK THEN INTO NEXT WEEK WITH TUESDAY
LOOKING EXCEPTIONALLY WARM AHEAD OF COOL FRONT THAT SHOULD KNOCK A
FEW DEGREES OFF OF HIGHS BY DAY 7. A DRY FORECAST WAS MAINTAINED
IN THE EXTENDED UNTIL ALONG AND POST FRONTAL TUE NIGHT/WEDNESDAY.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1229 AM CDT THU MAY 9 2013
.UPDATE...
ISSUED AT 1229 AM CDT THU MAY 9 2013
LATEST WATER VAPOR IMAGERY SHOWS A NORTHWESTERLY FLOW INTO NORTH
DAKOTA WITH AN UPSTREAM SHORTWAVE SEEN OVER SOUTHEAST ALBERTA. THE
00Z GFS SHOWS THIS H5-H3 SHORTWAVE WHICH TAKES IT JUST SOUTHEAST
OF GLASGOW BY 12Z THURSDAY. UPWARD VERTICAL MOTION PER H85-H3 OMEGA
LAYER AND UPPER LEVEL/H3 DIVERGENCE FIELD IS WEAK...WITH SCT TO BKN
MID/HIGH LEVEL CLOUDS PRESENT UPSTREAM AND THIS WILL TRANSLATE
WITH THE SHORTWAVE OVERNIGHT. WITH WEAK VERTICAL MOTION AND NO
SURFACE REFLECTION...WORST CASE SCENARIO IS SOME VIRGA POSSIBLE IN
THE BKN MID LEVEL DECK BUT NOT ENOUGH EVIDENCE OTHERWISE TO WARRANT
MEASURABLE POPS. THUS WILL CONTINUE WITH THE PREVIOUS FORECAST
WITH DRY CONDITIONS OVERNIGHT.
LATER THURSDAY...ANOTHER SHORTWAVE FOLLOWS BUT THE LATEST RAP/NAM/GFS
ALL INDICATE THAT THE PRECIPITATION FIELD REMAINS OUTSIDE OF OUR WESTERN
AND SOUTHWESTERN FORECAST PERIMETER. POPS WERE SCALED BACK EARLIER
FOR THURSDAY AND THIS TREND LOOKS GOOD. NO SIGNIFICANT CHANGES TO
CURRENT FORECAST.
UPDATE ISSUED AT 937 PM CDT WED MAY 8 2013
THE ONLY SIGNIFICANT CHANGE FOR THE FORECAST FOR TONIGHT INTO
TOMORROW WAS TO REMOVE POPS THROUGH 12 UTC...AND SCALE BACK TO
SLIGHT CHANCE NEAR THE MONTANA BORDER THROUGH THE DAY ON THURSDAY.
THE 00 UTC RAP/HRRR SIMULATED REFLECTIVITY DEPICT NO PRECIPITATION
THE REMAINDER OF THE NIGHT ACROSS EASTERN MONTANA AND WESTERN
NORTH DAKOTA...CONFIRMED BY ALL OTHER DETERMINISTIC MODELS OUTSIDE
OF THE 18 UTC GFS WHICH WAS DISCOUNTED. FOR TOMORROW...THE
SURFACE INSTABILITY AXIS LOOKS TO SETUP PRIMARILY ACROSS
SOUTHEAST MONTANA INTO NORTHEAST WYOMING...AND THUS SCALED BACK
POPS FOR THURSDAY TO JUST NEAR THE MONTANA BORDER. OTHERWISE...THE
FORECAST IS WELL ON TRACK FOR TONIGHT AND TOMORROW.
UPDATE ISSUED AT 648 PM CDT WED MAY 8 2013
NO SIGNIFICANT CHANGES REQUIRED WITH THIS FORECAST UPDATE OTHER
THAN TO BLEND TO THE 23 UTC OBSERVED TRENDS AND THE 22 UTC CONSENSUS
OF THE HIGH RESOLUTION NEAR TERM RAPIDLY UPDATING GUIDANCE. DID
MAINTAIN THE ISOLATED TO SCATTERED MENTION OF SHOWERS AND
THUNDERSTORM ACROSS THE FAR WEST LATE TONIGHT FOR NOW...AND WILL
RE-VISIT WITH THE 00 UTC RUNS. HOWEVER...WILL LIKELY DECREASE OR
REMOVE POPS WITH VERY WEAK FORCING AND MOISTURE ASSOCIATED WITH
THE IMPULSE PROPAGATING SOUTHEAST OUT OF CANADA THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS FOR THE REST OF THIS AFTERNOON AND EVENING WILL BE
THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHEAST.
THE MAIN FOCUS FOR TONIGHT AND TOMORROW WILL BE THE POSSIBILITY OF
SHOWERS AND THUNDERSTORMS IN THE WEST.
A COLD FRONT WAS SLOWLY PUSHING SOUTH THIS AFTERNOON ACROSS FAR
SOUTHERN NORTH DAKOTA. THE COLD FRONT WILL BE THE PRIMARY LOCATION
OF ANY SHOWERS OR THUNDERSTORMS THAT DO DEVELOP. AHEAD OF THE
FRONT THE ATMOSPHERE CONTINUES TO DESTABILIZE AS EVIDENCED BY THE
CU FIELD IN VISIBLE SATELLITE. THE 17 UTC RAP PAINTS 400+ J/KG OF
CAPE ACROSS SOUTHERN NORTH DAKOTA. THE 15 UTC HRRR MODEL HAS
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING ALONG AND AHEAD OF
THE FRONT LATER THIS AFTERNOON. ONE OF THE MAIN LIMITING FACTORS
ON WHETHER SHOWERS AND THUNDERSTORMS DEVELOP AND HOW WIDESPREAD
THEY BECOME IS THE BROAD SYNOPTIC SCALE SUBSIDENCE BEHIND THE
DEPARTING UPPER LEVEL LOW.
LATE TONIGHT AND TOMORROW MORNING A WEAK UPPER LEVEL SHORTWAVE TROUGH
WILL ENTER EASTERN MONTANA AND WESTERN NORTH DAKOTA. THIS SHORTWAVE
MAY PROVIDE ENOUGH ASCENT ALONG A DEVELOPING SURFACE BAROCLINIC
ZONE IN EASTERN MONTANA AND WESTERN NORTH DAKOTA TO SPARK SOME
ISOLATED RAIN SHOWERS. SURFACE HIGH PRESSURE AND COLD AIR
ADVECTION SHOULD KEEP CENTRAL AND EASTERN NORTH DAKOTA DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 358 PM CDT WED MAY 8 2013
THE MAIN FOCUS OF THE EXTENDED PERIOD WILL BE THE COLD FRONT THAT IS
PROGGED TO DROP SOUTH OUT OF SOUTHERN CANADA AND INTO THE NORTHWEST
BY FRIDAY MORNING. THIS FRONT WILL CONTINUE TO MOVE SOUTH OVER THE
AREA...WITH IT MOVING INTO SOUTH DAKOTA BY EARLY SATURDAY MORNING.
THE CONCERN WILL LIE AHEAD OF THIS FRONT...WHERE THUNDERSTORMS MAY
BE POSSIBLE. ACCORDING TO THE 12Z NAM...SURFACE BASED CAPE AHEAD OF
THIS FRONT WILL BE IN THE 500 TO 600 J/KG RANGE...WITH THE 0-6 KM
BULK SHEAR BEING MORE THAN SUFFICIENT FOR AIDING IN THE DEVELOPMENT
OF SEVERE THUNDERSTORMS. ON THE OTHER HAND...THE GFS DEPICTS THE
STRONG 0-6 KM BULK SHEAR...BUT DOES NOT PAINT ANY SURFACE BASED CAPE
NOR MOST UNSTABLE CAPE OVER THE AREA. MOISTURE WILL ALSO BE A
LIMITING FACTOR AS FORECAST DEWPOINTS WILL ONLY BE IN THE 30S AND
40S. CURRENT THINKING IS THAT THERE WILL BE WIDESPREAD SHOWER
ACTIVITY AHEAD OF THE FRONT AND THAT IF ANY THUNDERSTORMS THAT DO
DEVELOP WILL REMAIN BELOW THE SEVERE THRESHOLD AND WILL BE OF THE
GARDEN VARIETY TYPE.
AHEAD OF THE AFOREMENTIONED COLD FRONT...TEMPERATURES WILL WARM
WITH THE RETURN FLOW AND BE IN THE 60S AND LOWER 70S. AS THE FRONT
MOVES THROUGH THE AREA...TEMPERATURES WILL RETURN TO BELOW
NORMAL...WITH TEMPERATURES IN THE UPPER 40S TO MID 50S. SATURDAY
NIGHT AND INTO SUNDAY MORNING...THERE IS THE POTENTIAL FOR
TEMPERATURES TO FLIRT WITH THE FREEZING MARK ACROSS MOST OF THE AREA
AND POSSIBLY ENDANGER NEW VEGETATION AND PLANT GROWTH.
THEREAFTER...TEMPERATURES WILL AGAIN WARM SUNDAY AS A WARM FRONT
MOVES EAST AND AN UPPER LEVEL RIDGE BUILDS EAST OVER THE NORTHERN
PLAINS. TEMPERATURES WILL CLIMB ABOVE NORMAL MONDAY WITH HIGHS IN
THE LOW TO MID 80S AS THE RIDGE AXIS MOVES OVERHEAD.
FOR THE REMAINDER OF THE PERIOD (TUESDAY ONWARDS)...QUASIZONAL FLOW
WILL DEVELOP AND TEMPERATURES WILL RETURN TO SEASONAL NORMS. THERE
IS A POSSIBILITY FOR SHOWERS AND THUNDERSTORMS DURING MONDAY
EVENING...HOWEVER THEY ARE NOT EXPECTED TO BECOME SEVERE. SHOWERS
WILL CONTINUE THROUGH EARLY THURSDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1229 AM CDT THU MAY 9 2013
A COUPLE OF UPPER LEVEL DISTURBANCES WILL MOVE ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THE REST OF WEDNESDAY NIGHT THROUGH THURSDAY.
LATEST SATELLITE IMAGERY SHOWS SCT/BKN MID LEVEL CLOUDS ASSOCIATED
WITH THESE DISTURBANCES ARE FILTERING IN FROM CANADA. HOWEVER...VFR
CIGS/VSBYS WILL CONTINUE WITH THE 06Z TAF ISSUANCE ALONG WITH A
DRY FORECAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...AJ
LONG TERM...LTH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
417 AM EDT THU MAY 9 2013
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS ACROSS THE REGION THIS
MORNING. ANOTHER SYSTEM WILL BEGIN TO IMPACT THE AREA WITH
PRECIPITATION THIS AFTERNOON. A COLD FRONT WILL WORK THROUGH THE
REGION FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRECIPITATION HAS COME TO AN END ACROSS THE AREA THIS MORNING AND
CLOUD COVER HAS BEEN DECREASING OVER A LARGE PORTION OF THE AREA.
FOG HAS DEVELOPED ACROSS SOME LOCATIONS THIS MORNING. ALTHOUGH THE
FOG IS DENSE IN A FEW AREAS IT APPEARS TO BE PATCHY IN NATURE AT
THIS TIME. HIGHLIGHTED THE FOG IN THE HWO FOR THIS MORNING HOWEVER
DECIDED AGAINST ANY FOG HEADLINES DUE TO THE PATCHY NATURE OF THE
FOG. VISIBILITIES WILL IMPROVE ACROSS THE AREA THROUGH THE MORNING
DAYTIME HOURS.
SW WINDS WILL BRING WARMER AIR INTO THE FA TODAY WITH HIGH
TEMPERATURES EXPECTED TO BE IN THE UPPER 70S ACROSS THE FA. THE
NEXT SYSTEM WILL BEGIN TO WORK INTO MAINLY WESTERN PORTIONS OF THE
FA THIS AFTERNOON BRINGING SHOWERS AND THUNDERSTORMS TO THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
AN AREA OF LOW PRESSURE WILL BEGIN TO APPROACH THE AREA TONIGHT
AND WILL BE SITUATED NW OF THE FA BY FRIDAY MORNING. THIS FEATURE
WILL ALLOW FOR SHOWERS TO CONTINUE TO MOVE INTO THE AREA THROUGH
THE OVERNIGHT HOURS THURSDAY NIGHT. INSTABILITY IS LIMITED ACROSS
THE FA THURSDAY NIGHT AND THEREFORE LIMITED THUNDER MENTION TO A
SLIGHT CHANCE FOR MOST OF THE TONIGHT TIME FRAME.
BETTER INSTABILITY WILL BE IN PLACE ACROSS THE FA FOR FRIDAY AND
THEREFORE INCREASED THE THUNDER MENTION FOR THE DAYTIME HOURS ON
FRIDAY. MODELS ARE IN PRETTY GOOD AGREEMENT WITH THIS SYSTEM AND
THEREFORE INCREASED PRECIPITATION CHANCES ACROSS THE FA FOR
FRIDAY. SOME OF THE THUNDERSTORM ACTIVITY HAS THE POTENTIAL TO
BECOME SEVERE ACROSS THE AREA ON FRIDAY WITH THE MAIN THREATS
BEING DAMAGING WINDS AND LARGE HAIL. THE BEST CHANCE FOR SEVERE
THUNDERSTORMS WILL BE ACROSS THE SE HALF OF THE FA. CONTINUED TO
MENTION THE POTENTIAL FOR SEVERE WEATHER IN THE HWO FOR A MAJORITY
OF THE FA FOR FRIDAY.
A COLD FRONT WILL WORK INTO THE FA FRIDAY NIGHT AND INTO SATURDAY
MORNING. AFTER THIS FRONTAL PASSAGE THERE WILL BE SOME RESIDUAL
SHOWER ACTIVITY HOWEVER MOST OF THE THUNDERSTORM ACTIVITY WILL
DECREASE ACROSS THE FA THROUGH THE NIGHT FRIDAY NIGHT INTO
SATURDAY MORNING.
COOLER AND WELL BELOW NORMAL TEMPERATURES WILL WORK INTO THE AREA FOR THE
WEEKEND AFTER THE PASSAGE OF THE FRONTAL BOUNDARY. HIGH PRESSURE
WILL GRADUALLY WORK INTO THE REGION. SUNDAY NIGHT IS LOOKING TO BE A GOOD
RADIATIONAL COOLING NIGHT WITH LIGHT WINDS AND MOSTLY CLEAR SKIES.
THIS WILL ALLOW TEMPERATURES TO DROP DOWN INTO THE 30S ACROSS THE
FA SUNDAY NIGHT AND WILL LEND ITSELF TO THE POTENTIAL FOR FROST.
CONTINUED TO MENTION FROST IN THE FORECAST AND IN THE HWO. HIGH
PRESSURE WILL CONTINUE TO KEEP DRY CONDITIONS ACROSS THE FA FOR
MONDAY. WITH COOL NW FLOW ACROSS THE FA ON MONDAY BELOW NORMAL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 50S TO LOW 60S.
&&
.LONG TERM /TUESDAY THROUGH WEDNESDAY/...
THE HIGH WILL SLOWLY PUSH OFF TO THE EAST THROUGH MID
WEEK...RESULTING IN DRY CONDITIONS AND WARMING TEMPERATURES EACH
DAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SATELLITE IMAGERY SHOWS A BROKEN DECK OF MID CLOUDS STILL MOVING
SOUTHEAST ACROSS THE REGION. RAP SEEMS TO HAVE A BETTER HANDLE ON
THIS AND SUGGESTS THAT THESE CLOUDS COULD LAST WELL THROUGH THE
NIGHT AT ALL BUT THE COLUMBUS TERMINALS. THIS SHOULD MINIMIZE
VISIBILITY ISSUES. HOWEVER KLUK HAS BEEN TRYING TO GO DOWN WHEN
THERE ARE BREAKS IN THE CLOUDS. AND IF THERE IS CLEARING THERE
LATE IN THE NIGHT THEN EXPECT LIFR TO PREVAIL.
HEADING INTO THE DAY IT APPEARS THAT THERE WILL ONLY BE SOME HIGH
AND MID CLOUDS UNTIL AFTERNOON WHEN CUMULUS DEVELOP. SCATTERED
SHOWERS AND STORMS MAY MOVE IN AFTER 18Z WITH ANY ACTIVITY
DIMINISHING AROUND 00Z. STILL EXPECT A FAIR AMOUNT OF MID AND HIGH
CLOUDS TO LINGER LATE IN THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH THUNDERSTORMS
FRIDAY AFTERNOON AND EVENING. MVFR TO IFR CEILINGS AND MVFR
VISIBILITIES LIKELY LATE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...NOVAK
SHORT TERM...NOVAK
LONG TERM...JGL
AVIATION...
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
134 AM EDT THU MAY 9 2013
.SYNOPSIS...
LOW PRESSURE WILL EXIT OUR REGION TONIGHT AS WEAK HIGH PRESSURE
BUILDS ACROSS OUR AREA. ANOTHER LOW PRESSURE SYSTEM WILL BRING A
CHANCE FOR PRECIPITATION LATE THURSDAY THROUGH FRIDAY. A STRONG
COLD FRONT WILL CROSS OUR AREA OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SCATTERED THUNDERSTORMS HAVE LINGERED INTO THE LATE EVENING AND
HAVE UPDATED FORECAST TO EXPAND AREA AND DURATION. STORM REPORTS
HAVE BEEN LIMITED TO SMALL HAIL. STILL EXPECT CONVECTION TO DIE
OFF WITHIN THE NEXT FEW HOURS...LEAVING PARTLY CLOUDY SKIES.
HIGHER MOISTURE CONTENT ACROSS THE SOUTH COULD RESULT IN FOG
DEVELOPMENT TONIGHT. THE MAIN LIMITING FACTOR FOR DENSE FOG
TONIGHT IS THE APPROACH OF HIGH CLOUDS FROM THE WEST LATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
THE UPPER LOW THAT HAS BEEN AFFECTING OUR WEATHER FOR THE PAST
SEVERAL DAYS WILL EXIT OUR REGION TONIGHT AS MID LEVEL RIDGING
BUILDS EASTWARD ACROSS OUR AREA. MAINLY FAIR WEATHER WITH WARM
TEMPERATURES ARE EXPECTED THROUGH THURSDAY AFTERNOON. CONVECTION
WILL BE SOMEWHAT LIMITED THURSDAY AFTERNOON DUE TO THE LACK OF ANY
APPRECIABLE FORCING. HOWEVER...THERE WILL BE SUFFICIENT DAYTIME
HEATING TO HELP TRIGGER SCATTERED SHOWERS WITH A POSSIBLE
THUNDERSTORM LATE AFTERNOON AND EARLY EVENING. LOW PRESSURE
CROSSING THE MIDWESTERN STATES WILL TRIGGER THUNDERSTORM
DEVELOPMENT TO OUR WEST IN AN INCREASINGLY UNSTABLE AIRMASS ON
THURSDAY. CONVECTION ALLOWING MODELS ARE IN FAIR AGREEMENT ON
BRINGING THE REMAINS OF THIS CONVECTION INTO OUR WESTERN ZONES
JUST AFTER SUNSET. SHEAR WILL BE INCREASING...ESPECIALLY IN THE
0-3 KM LEVELS THURSDAY EVENING. HOWEVER...INSTABILITY WILL BE ON
THE DECREASE. THEREFORE THE PROBABILITY FOR SEVERE WEATHER
OCCURRING THURSDAY EVENING AND THURSDAY NIGHT ACROSS OUR AREA
APPEARS LOW AT THIS TIME.
SHOWERS WITH A POSSIBLE RUMBLE OF THUNDER WILL OCCUR THURSDAY
NIGHT AS THE REMNANTS OF THURSDAYS CONVECTION TO OUR WEST PASSES
ACROSS PORTIONS OF OUR AREA. TEMPERATURES WILL BE MILD THURSDAY
NIGHT WITH WEAK SOUTHERLY FLOW. TEMPERATURES WILL STAY IN THE 60S
FOR THE MOST PART OVERNIGHT THURSDAY NIGHT.
A FRONTAL BOUNDARY WILL BE JUST NORTHWEST OF OUR AREA FRIDAY AS
THE AFOREMENTIONED LOW PASSES ACROSS THE SOUTHERN GREAT LAKES. OUR
AREA WILL LIE IN THE WARM SECTOR WITH INSTABILITY INCREASING THE
FIRST PARTS OF THE DAY FRIDAY...ESPECIALLY SOUTH OF THE INTERSTATE
71 CORRIDOR. MODELS ARE SHOWING INCREASING 0-3 KM SHEAR UP TO 40
KT ACROSS OUR SOUTHEAST CO-LOCATED WITH THE SECTOR OF INCREASED
INSTABILITY DURING THE EARLY AFTERNOON. CONVECTION WILL DEVELOPING
WITH PRE-FRONTAL FORCING ACROSS OUR AREA FRIDAY. INCREASED POPS TO
LIKELY AND CATEGORICAL FOR THE FRIDAY PERIOD. WHEN CONVECTION
DEVELOPS ACROSS THE SOUTHEASTERN PARTS OF OUR AREA...WITH THE ABOVE
MENTIONED SHEAR AND INSTABILITY...STORMS COULD BECOME ORGANIZED.
THE MAIN THREAT FROM THESE STORMS WILL BE DAMAGING WINDS AND LARGE
HAIL. WILL MENTION THIS THREAT IN THE HWO. ACROSS OUR
NORTHWEST...INSTABILITY AND SHEAR WILL BOTH BE WEAKER ON
FRIDAY...LIMITING THE THREAT FOR SEVERE WEATHER THERE.
PRECIPITATION WILL CONTINUE AHEAD OF THE FRONT INTO FRIDAY NIGHT.
INSTABILITY WILL DECREASE INTO THE EVENING...ENDING ANY SEVERE
THREAT ACROSS THE SOUTHEAST AND ENDING CHANCES FOR THUNDER
OVERNIGHT AS WELL. THE FRONT WILL PUSH SOUTHEAST OVERNIGHT FRIDAY
NIGHT WITH SHOWERS DECREASING TOWARD DAYBREAK SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE INITIAL COLD FRONT WILL BE PUSHING EAST OF THE AREA SATURDAY
MORNING WITH THE BULK OF THE PCPN ENDING ACROSS OUR EAST.
HOWEVER...A SECONDARY COLD FRONT WILL MOVE IN FROM THE NORTHWEST
SATURDAY AFTERNOON INTO SATURDAY EVENING. WEAK FORCING AND A NARROW
BAND OF DEEPER MOISTURE ALONG THE SECONDARY FRONT MAY BE ENOUGH TO
PRODUCE A FEW SHOWERS. EXPECT HIGHS GENERALLY IN THE MID 60S...BUT
POSSIBLY LEVELING OFF ACROSS AT LEAST THE NORTHWEST THROUGH THE
AFTERNOON AS BETTER CAA SETS UP.
AN UNSEASONABLY COOL AIRMASS WILL THEN SETTLE INTO THE AREA FOR
EARLY NEXT WEEK AS SURFACE HIGH PRESSURE BUILDS IN FROM THE WEST.
IT LOOKS LIKE THE HIGH WILL BE CENTERED JUST OFF TO OUR WEST AT 12Z
MON SO WE SHOULD END UP WITH GOOD RADIATIONAL COOLING SUNDAY NIGHT.
WILL CONTINUE TO TREND COOLER THAN GUIDANCE WITH LOWS GENERALLY IN
THE MID 30S AND INDICATE AREAS OF FROST. THE HIGH WILL SLOWLY PUSH
OFF TO THE EAST THROUGH MID WEEK...RESULTING IN DRY CONDITIONS AND
WARMING TEMPERATURES EACH DAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SATELLITE IMAGERY SHOWS A BROKEN DECK OF MID CLOUDS STILL MOVING
SOUTHEAST ACROSS THE REGION. RAP SEEMS TO HAVE A BETTER HANDLE ON
THIS AND SUGGESTS THAT THESE CLOUDS COULD LAST WELL THROUGH THE
NIGHT AT ALL BUT THE COLUMBUS TERMINALS. THIS SHOULD MINIMIZE
VISIBILITY ISSUES. HOWEVER KLUK HAS BEEN TRYING TO GO DOWN WHEN
THERE ARE BREAKS IN THE CLOUDS. AND IF THERE IS CLEARING THERE
LATE IN THE NIGHT THEN EXPECT LIFR TO PREVAIL.
HEADING INTO THE DAY IT APPEARS THAT THERE WILL ONLY BE SOME HIGH
AND MID CLOUDS UNTIL AFTERNOON WHEN CUMULUS DEVELOP. SCATTERED
SHOWERS AND STORMS MAY MOVE IN AFTER 18Z WITH ANY ACTIVITY
DIMINISHING AROUND 00Z. STILL EXPECT A FAIR AMOUNT OF MID AND HIGH
CLOUDS TO LINGER LATE IN THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH THUNDERSTORMS
FRIDAY AFTERNOON AND EVENING. MVFR TO IFR CEILINGS AND MVFR
VISIBILITIES LIKELY LATE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...CONIGLIO/LATTO
SHORT TERM...LATTO
LONG TERM...JGL
AVIATION...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
558 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE CENTERED ACROSS THE LOWER SUSQUEHANNA
VALLEY EARLY TODAY WILL DRIFT SLOWLY NORTHEAST INTO THE CATSKILL
REGION OF SOUTHEASTERN NEW YORK LATER TODAY. WEAK HIGH PRESSURE WILL
BUILD EAST OVER THE COMMONWEALTH THIS AFTERNOON INTO EARLY FRIDAY.
MILDER...AND MORE HUMID AIR WILL PUSH INTO THE REGION FRIDAY
AFTERNOON THROUGH SATURDAY...AHEAD OF A STRONG COLD FRONT THAT WILL
BRING UNSEASONABLY COOL AIR TO THE REGION LATER IN THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SLOWLY WEAKENING UPPER LOW...CENTERED OVER THE MIDDLE SUSQ VALLEY
AT 09Z WILL DRIFT SLOWLY TO THE NE TODAY. 08/21Z AND 09/03Z SREF...
AND THE LATEST HRRR GUIDANCE INDICATES THAT THE CURRENT...
SLOWLY EXPANDING AREA OF SHOWERS ACRS THE CENTRAL AND NRN MTNS
WILL CONTINUE TO SPREAD SOUTH AND EAST THROUGH THE MID TO LATE
MORNING HOURS /TWD THE KIPT...KSEG AND KMDT AREAS/. EXPECT AN
AVERAGE OF 1-3 TENTHS OF RAINFALL WITH SOME LOCALLY HEAVIER
AMOUNTS POSSIBLE BETWEEN 09Z-14Z. THE BULK OF THE SHOWERS
THROUGH 14Z SHOULD STAY JUST TO THE WEST AND SOUTH OF KIPT...
AND ALSO JUST NORTH OF KAOO.
WET GROUND OVR MUCH OF THE AREA...COMBINED WITH A NEARLY CALM WIND
AND A FEW BREAKS IN THE OVERCAST...SHOULD RESULT IN AREAS OF FOG
THROUGH THE MID MORNING HOURS. LOW TEMPS AROUND DAYBREAK SHOULD
RANGE FROM THE U40S ACROSS THE ALLEGHENY PLATEAU...TO THE L50S
ELSEWHERE.
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL NARROW/QUASI
STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA SETTING UP ON A
NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE WEST AND SW OF
THE DEPARTING UPPER LOW. A NARROW RIBBON OF RELATIVELY HIGHER PWAT
AIR /JUST OVER AND INCH/ WILL BE SHIFTING SLOWLY EAST FROM THE
ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ VALLEY BY EARLY THIS
EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CATEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENEISIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLOOD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A LOW PRESSURE SYSTEM MOVING THROUGH PA IS FORECAST TO SLOWLY
LIFT NORTHEAST INTO NEW ENGLAND THROUGH FRIDAY. SCATTERED SHOWERS
MOVING AROUND THIS LOW WILL CONTINUE THROUGH THE MORNING AND
AFTERNOON. THE SHOWERS WILL BE MAINLY LIGHT THROUGH THE MORNING
HOURS...INTENSIFYING BY LATE MORNING AND AFTERNOON DUE TO
CONVECTION. DUE TO THE COPIOUS MOISTURE...EXPECT PATCHY
FOG/MIST...ESPECIALLY AT MDT AND LNS AND REGIONS WHERE MORE
WIDESPREAD PRECIPITATION FELL YESTERDAY...THROUGH 12Z. EXPECT
MVFR/IFR...WITH SOME SITES POTENTIALLY REACHING LIFR... VSBYS
THIS MORNING. ANY FOG/MIST WILL LIFT/DISSIPATE BY MID
MORNING...WITH SHOWERS CONTINUING AND THUNDERSTORMS POSSIBLE IN
AFTERNOON. IFR CIGS AND VSBYS ARE POSSIBLE IN AND AROUND
THUNDERSTORM ACTIVITY...WHERE THE HIGHEST PROBABILITIES WILL BE AT
UNV AND IPT.
WEAK HIGH PRESSURE WILL BUILD EAST OVER THE COMMONWEALTH LATE
THIS AFTERNOON INTO EARLY FRIDAY...BRINGING MOSTLY VFR FLYING
CONDITIONS.
.OUTLOOK...
FRI...COLD FRONT MOVES THROUGH. SCT SHOWERS AND PERHAPS A
THUNDERSTORM LATE ACCOMPANIED BY LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH ANOTHER COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS
EVENING FOR PAZ006-012-037-041-045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
545 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE CENTERED ACROSS THE LOWER SUSQUEHANNA
VALLEY EARLY TODAY WILL DRIFT SLOWLY NORTHEAST INTO THE CATSKILL
REGION OF SOUTHEASTERN NEW YORK LATER TODAY. WEAK HIGH PRESSURE WILL
BUILD EAST OVER THE COMMONWEALTH THIS AFTERNOON INTO EARLY FRIDAY.
MILDER...AND MORE HUMID AIR WILL PUSH INTO THE REGION FRIDAY
AFTERNOON THROUGH SATURDAY...AHEAD OF A STRONG COLD FRONT THAT WILL
BRING UNSEASONABLY COOL AIR TO THE REGION LATER IN THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SLOWLY WEAKENING UPPER LOW...CENTERED OVER THE MIDDLE SUSQ VALLEY
AT 09Z WILL DRIFT SLOWLY TO THE NE TODAY. 08/21Z AND 09/03Z SREF...
AND THE LATEST HRRR GUIDANCE INDICATES THAT THE CURRENT...
SLOWLY EXPANDING AREA OF SHOWERS ACRS THE CENTRAL AND NRN MTNS
WILL CONTINUE TO SPREAD SOUTH AND EAST THROUGH THE MID TO LATE
MORNING HOURS /TWD THE KIPT...KSEG AND KMDT AREAS/. EXPECT AN
AVERAGE OF 1-3 TENTHS OF RAINFALL WITH SOME LOCALLY HEAVIER
AMOUNTS POSSIBLE BETWEEN 09Z-14Z. THE BULK OF THE SHOWERS
THROUGH 14Z SHOULD STAY JUST TO THE WEST AND SOUTH OF KIPT...
AND ALSO JUST NORTH OF KAOO.
WET GROUND OVR MUCH OF THE AREA...COMBINED WITH A NEARLY CALM WIND
AND A FEW BREAKS IN THE OVERCAST...SHOULD RESULT IN AREAS OF FOG
THROUGH THE MID MORNING HOURS. LOW TEMPS AROUND DAYBREAK SHOULD
RANGE FROM THE U40S ACROSS THE ALLEGHENY PLATEAU...TO THE L50S
ELSEWHERE.
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL NARROW/QUASI
STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA SETTING UP ON A
NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE WEST AND SW OF
THE DEPARTING UPPER LOW. A NARROW RIBBON OF RELATIVELY HIGHER PWAT
AIR /JUST OVER AND INCH/ WILL BE SHIFTING SLOWLY EAST FROM THE
ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ VALLEY BY EARLY THIS
EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CAEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENEISIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLODD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A LOW PRESSURE SYSTEM MOVING THROUGH PA IS FORECAST TO SLOWLY
LIFT NORTHEAST INTO NEW ENGLAND THROUGH FRIDAY. MAJOR CONVECTIVE
ACTIVITY HAS SUBSIDED...WITH ONLY SCATTERED SHOWERS MOVING FROM THE
NORTH...SPREADING OVER CENTRAL PA. DUE TO THE COPIOUS MOISTURE
THERE IS THE LIKELIHOOD OF FOG...WHICH WILL INCREASE AFTER
07Z...AND BE STRONGEST FROM 09-13Z...ESP OVER EASTERN TAF SITES
WHERE MORE WIDESPREAD RAINS FELL TODAY FROM MDT NORTH TO IPT.
EXPECT MVFR/IFR...WITH SOME SITES POTENTIALLY REACHING LIFR...
VSBYS THURSDAY MORNING.
WEAK HIGH PRESSURE WILL BUILD EAST OVER THE COMMONWEALTH LATE
THURSDAY AFTERNOON INTO EARLY FRIDAY...BRINGING MOSTLY VFR FLYING
CONDITIONS.
.OUTLOOK...
THU...WIDESPREAD MVFR/IFR IN MORNING FOG. THEN MAINLY VFR
CONDITIONS WITH MVFR SCATTERED SHOWERS AND ISOLATED TSTMS.
FRI...COLD FRONT MOVES THROUGH. SCT SHOWERS AND PERHAPS A
THUNDERSTORM LATE ACCOMPANIED BY LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH ANOTHER COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 10 AM EDT THIS MORNING THROUGH THIS
EVENING FOR PAZ006-012-037-041-045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1033 AM EDT THU MAY 9 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND INTO THE REGION THROUGH FRIDAY UNTIL A
COLD FRONT PASSES OVER THE FORECAST AREA LATE THIS WEEKEND. COOLER
HIGH PRESSURE WILL THEN SETTLE OVER THE REGION THROUGH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATE THIS MORNING...A CLOSED UPPER LOW OVER THE NORTHEAST WILL
CONTINUE TO PULL AWAY FROM THE AREA TODAY AS HEIGHTS RISE AND
RIDGING BUILDS. SURFACE HIGH PRESSURE CENTERED OVER THE EASTERN
GULF OF MEXICO WILL DOMINATE THE PATTERN TODAY WITH LIGHT
SOUTHWEST FLOW. THE MAIN QUESTION FOR THE AFTERNOON FORECAST IS
THE POTENTIAL FOR ISOLATED SHOWER/THUNDERSTORM DEVELOPMENT. LOW
LEVEL THICKNESS VALUES SUPPORT HIGHS AROUND THE MID 80S...AND WHEN
MODIFYING THE 12Z CHS SOUNDING...THAT WOULD GENERATE POSITIVE CAPE
VALUES. HOWEVER...WITH THE RIDGE BUILDING ALOFT AND HEIGHTS
RISING...MID LEVEL TEMPS ARE PROGGED TO WARM WHICH IS EXPECTED TO
THWART ANY CONVECTIVE DEVELOPMENT. COARSER RESOLUTION MODELS ARE
GENERATING SOME CONVECTION RIGHT ALONG THE COAST IN THE LATE
AFTERNOON...WHILE HIGHER RESOLUTION RUNS FAVOR THE DRY SIDE.
LOOKING THROUGH AFTERNOON RAP SOUNDINGS SHOWS THE POTENTIAL FOR
VERY THIN CAPE...PRIMARILY ACROSS SOUTHEAST SC. WITH THE WESTERLY
FLOW IN PLACE...HAVE DECIDED TO STICK WITH A DRY FORECAST AND
FAVOR THE HIGHER RESOLUTION MODEL RUNS. OTHERWISE...EXPECT A
DECENT GOOD DIURNAL CU FIELD BEGINNING IN THE EARLY AFTERNOON AND
THEN DISSIPATING IN THE EARLY EVENING WITH THE LOSS OF HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...THE AREA WILL REMAIN ALONG THE WESTERN PERIPHERY OF
ATLANTIC HIGH PRESSURE TONIGHT. ANY LINGERING CUMULUS WILL QUICKLY
DISSIPATE WITH THE LOSS OF INSOLATION LEAVING MAINLY CLEAR SKIES.
THERE WILL BE SOME INCREASE IN HIGH-LEVEL MOISTURE EARLY
FRIDAY...BUT THE MOISTURE LOOKS PRETTY THIN AT THIS TIME. A MOSTLY
CLEAR SKY CHARACTER SHOULD WORK. MODEL 925MB WIND FIELDS DO NOT
INCREASE SUBSTANTIALLY OVERNIGHT SO EXPECT THE BOUNDARY LAYER TO
DECOUPLE RATHER QUICKLY THIS EVENING WITH FAIRLY LIGHT WIND FIELDS
PREVAILING...ESPECIALLY INLAND. LOWS WILL BOTTOM OUT IN THE LOWER
60S MOST LOCATIONS WITH MID 60S AT THE COAST. COULD SEE A FEW
UPPER 50S IN A FEW OF THE NORMALLY COOLER SITES SUCH AS ALLENDALE
AND JAMESTOWN.
FRIDAY...QUIET CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND WITH
WEAK HIGH PRESSURE AT THE SFC AND MID LVL RIDGING PEAKING ALOFT.
TEMPS WILL WARM CONSIDERABLY WITH SOUTHERLY FLOW IN PLACE UNDER
MOSTLY SUNNY SKIES. 1000-850 MB THICKNESSES FAVOR HIGH TEMPS IN THE
MID/UPPER 80S FRIDAY AFTERNOON...HIGHEST OVER INLAND AREAS IN
SOUTHEAST GEORGIA. FRIDAY NIGHT LOWS SHOULD REMAIN IN THE LOW/MID
60S AHEAD OF A COLD FRONT ADVANCING TO THE SOUTHEASTERN UNITED
STATES.
SATURDAY AND SUNDAY...CHANCES OF PRECIP WILL BEGIN TO INCREASE FOR
THE SECOND HALF OF THIS WEEKEND AS MID LVL RIDGING SLIDES EAST WHILE
SUBTLE H5 SHORTWAVES EJECT FROM THE SOUTHERN PLAINS TOWARDS THE
SOUTHEASTERN UNITED STATES. SHOWERS AND/OR THUNDERSTORM ACTIVITY
SHOULD INCREASE BY SATURDAY AFTERNOON/EVENING AS ISENTROPIC ASCENT
INCREASES AND BOUNDARY LAYER MOISTURE DEEPENS AHEAD OF A COLD FRONT
ADVANCING TOWARDS THE FORECAST AREA LATE. DESPITE INCREASING CLOUD
COVER...SFC TEMPS SHOULD PEAK IN THE LOW/MID 80S ON SATURDAY. PRECIP
COVERAGE SHOULD EXPAND SATURDAY NIGHT AS PWATS APPROACH 1.50-1.75
INCHES ALONG/AHEAD OF THE COLD FRONT.
AT THIS TIME...PRECIP ACTIVITY LOOKS TO PEAK AS THE COLD FRONT
PUSHES THROUGH THE FORECAST AREA SUNDAY MORNING. GIVEN THE TIME OF
COLD FROPA...THE CHANCE OF STRONGER THUNDERSTORMS WILL REMAIN LOW.
HOWEVER...SOME SHOWERS AND/OR THUNDERSTORMS MAY PRODUCE HEAVY RAIN
BEFORE THE COLD FRONT SHIFTS OFFSHORE. CONDITIONS WILL LIKELY
IMPROVE OVER THE AREA THROUGH SUNDAY EVENING AS HIGH PRESSURE BEGINS
TO BUILD IN BEHIND THE COLD FRONT SHIFTING OFFSHORE. GIVEN THE
AMOUNT OF CLOUD COVER AND SHOWER/THUNDERSTORM ACTIVITY...OVERALL
HIGH TEMPS WILL REMAIN COOLER ON SUNDAY...IN THE UPPER 70S TO AROUND
80.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A QUIET PERIOD OF WEATHER IS ANTICIPATED NEXT WEEK AS DRY AND COOLER
HIGH PRESSURE BUILDS IN BEHIND A COLD FRONT SHIFTING OVER THE
WESTERN ATLANTIC. MONDAY COULD START OFF BREEZY AS COOLER AIR SHIFTS
SOUTH OVER THE FORECAST AREA INITIALLY. OVERALL TEMPS WILL REMAIN IN
THE LOW/MID 70S MONDAY AND TUESDAY AS THE AREA REMAINS UNDER A
NORTHERLY FLOW. OVERNIGHT LOWS WILL ALSO BE COOL...IN THE UPPER 40S
TO LOWER 50S. TEMPS SHOULD THEN GRADUALLY WARM WEDNESDAY AND
THURSDAY AS SFC HIGH PRESSURE BECOMES CENTERED OVER THE SOUTHEASTERN
UNITED STATES WHILE A DOWNSLOPING WIND COMPONENT DEVELOPS OVER THE
FORECAST AREA. IN GENERAL...OVERALL TEMPS WILL WARM TO AROUND 80 ON
WEDNESDAY AND THEN INTO THE LOWER 80S ON THURSDAY.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS WITH
COLD FRONTAL PASSAGE SATURDAY/SUNDAY.
&&
.MARINE...
TODAY AND TONIGHT...THERE ARE NO CONCERNS. A BROAD SOUTHERN FLOW
REGIME WILL PERSIST WITH SPEEDS GENERALLY 10-15 KT AND SEAS 2-4
FT.
FRIDAY THROUGH TUESDAY...MARINE CONDITIONS WILL REMAIN QUIET THROUGH
LATE WEEK AS HIGH PRESSURE REMAINS OVER THE WATERS. IN
GENERAL...WINDS WILL REMAIN AT OR BELOW 15 KTS...HIGHEST ALONG THE
COAST EACH AFTERNOON WITH SEABREEZE CIRCULATIONS. SEAS WILL REMAIN
AT OR BELOW 4 FT...HIGHEST OVER NORTHERN SC WATERS AND OUTER GEORGIA
WATERS. WINDS/SEAS WILL THEN GRADUALLY INCREASE/BUILD LATE WEEKEND
ALONG/AHEAD OF A COLD FRONT PASSING OVER THE WATERS ON SUNDAY.
ALTHOUGH CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS
WITH COLD FROPA...COOL HIGH PRESSURE BEHIND THE FRONT SHOULD RESULT
IN WINDS OF 15-20 KTS ALONG WITH SEAS BUILDING TO 4-5 FT ON
MONDAY...HIGHEST OVER WATERS BEYOND 10 NM FROM THE COAST. CONDITIONS
WILL THEN IMPROVE BY TUESDAY AND REMAIN WELL BELOW ADVISORY LEVELS
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...DPB/ST
LONG TERM...DPB
AVIATION...ST
MARINE...DPB/ST
AREA FORECAST DISCUSSION
NWS DES MOINES IA
702 AM CDT THU MAY 9 2013
.SHORT TERM.../TODAY/
ISSUED AT 348 AM CDT THU MAY 9 2013
MAIN CONCERN THIS MORNING WILL BE CONVECTIVE TRENDS...ESPECIALLY
HEAVY RAIN POTENTIAL. COMPACT SHORT WAVE/PV ANOMALY CONTINUES TO
SLOWLY CROSS THE NE/IA BORDER. FORCING AHEAD OF FEATURE IS NOT
EXTREME...BUT COUPLED WEAK/MODERATE THERMODYNAMIC AND KINEMATIC
FORCING HAS SUSTAINED AND EVEN RECENTLY ENHANCED CONVECTION FROM SW
INTO CENTRAL IA. THIS IN SOME WAYS RESEMBLES A LOW END SHARS EVENT
BUT WITH LESS FAVORABLE ENVIRONMENT. SEVERE POTENTIAL HAS
DIMINISHED WITH NIL EFFECTIVE SHEAR AND MUCAPES ONLY SEVERAL HUNDRED
J/KG. HEAVY RAIN CONDITIONS ARE NOT GREAT EITHER WITH PWS JUST
OVER AN INCH AND WARM CLOUD DEPTHS UNDER 1K FT. HOWEVER MEAN CELL
MOTION IS CURRENTLY 230 AT ONLY 16KTS SO SUM ALL FACTORS TOGETHER
WITH SLOW MOVEMENT COULD STILL LEAD TO HEAVY RAINS WHICH
UNFORTUNATELY MAY IMPACT THE MORNING COMMUTE. ADAIR AND PERRY HAVE
ALREADY RECEIVED 1.7 INCHES SINCE MIDNIGHT. CONDITIONS CHANGE
LITTLE THROUGH THE MORNING WITH CATEGORICAL POPS...BUT OVERALL
FORCING DIMINISHES INTO THE AFTERNOON WITH LESS COVERAGE
ANTICIPATED. CANNOT ARGUE WITH 05Z HRRR DEPICTION TOO MUCH.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/
ISSUED AT 348 AM CDT THU MAY 9 2013
WE WILL BE CONTINUING TO DEAL WITH THE REMNANTS OF THE SOUTH DAKOTA
LOW AND THE SOUTHERN STREAM SHORT WAVE PUSHING ACROSS THE FORECAST
AREA TONIGHT. THE SLOW MOVEMENT OF THE STORMS IN THE WEAK FLOW OVER
IOWA HAS PROVEN TO MAKE EFFICIENT RAIN PRODUCING STORMS BUT WE LOSE
WHATEVER WEAK FORCING WE HAD IN PLACE FROM TODAY SO I DON`T SEE AS
MUCH RAINFALL TONIGHT.
SOME LINGERING PRECIP EXPECTED ACROSS THE SOUTHEAST INTO FRIDAY
MORNING THEN A BREAK AS WEAK HIGH PRESSURE BUILDS IN AT THE SURFACE
WHILE ALOFT WE ARE IN BETWEEN SYSTEMS. FRIDAY NIGHT INTO SATURDAY A
LARGE LOW PRESSURE SYSTEM OVER CANADA CARVES A TROUGH INTO THE UPPER
MIDWEST. AT THE SURFACE A STRONG COLD FRONT WILL WORK ACROSS THE
AREA BRINGING A SHOT FOR MORE RAIN AND MUCH COLDER TEMPERATURES ALONG
WITH BREEZY CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL BE
DROPPING INTO THE LOW TO MID 30S SATURDAY NIGHT SO FROST HAS TO
ENTER THE THOUGHT PROCESS HERE BUT WINDS AT LEAST THROUGH THE
EVENING...AND PROBABLY ALL NIGHT ACROSS THE EAST...WILL STAY UP
ENOUGH TO MINIMIZE THE FROST THREAT. HOWEVER AT THIS POINT I THINK
IT IS ENOUGH OF A THREAT TO PUT IT IN THE FORECAST GRIDS ACROSS
NORTH FOR A FEW HOURS BEFORE DAYBREAK. THIS WILL NEED TO BE
MONITORED FOR THE POTENTIAL FOR MORE THAN JUST A MENTION.
THE COLD WILL BE SHORT LIVED AS A LARGE UPPER LEVEL RIDGE BUILDS
ACROSS THE ROCKIES THEN SHIFTS EAST EARLY NEXT WEEK. TUESDAY STILL
LOOKS VERY WARM AND WHILE I WAS NOT BOLD ENOUGH TO MENTION A 90
DEGREE READING I DID BUMP TEMPS UP INTO THE MID TO UPPER 80S. THE
UPPER RIDGE FLATTENS INTO MIDWEEK KNOCKING TEMPS BACK SEVERAL
DEGREES. A FRONTAL BOUNDARY WILL SAG INTO THE REGION PRODUCING A
CHANCE FOR THUNDERSTORMS TUESDAY NIGHT. TEMPERATURES THROUGH
MIDWEEK WHILE COOLER...WILL STILL BE SEASONAL INTO THURSDAY WITH
HIGHS IN THE 70S.
&&
.AVIATION...09/12Z
ISSUED AT 700 AM CDT THU MAY 9 2013
FORECAST WILL BE SOMEWHAT PROBLEMATIC WITH LOW CONFIDENCE THROUGH
THE PERIOD. CONDITIONS ARE QUITE VARIED ACROSS CENTRAL IA AND TAFS
SITES FROM VFR TO IFR AND EVEN LIFR FARTHER NW. SYSTEM PRODUCE
RECENT SHOWERS WILL MOVE SLOWLY TODAY WITH OCCASIONAL
SHOWERS...ESPECIALLY THIS MORNING. CONFIDENCE IN TIMING AND
LOCATION OF ANY ADDITIONAL PRECIP IS QUITE LOW SO WILL NOT INCLUDE
ANY OTHER MENTION OUTSIDE OF CURRENT TRENDS. THUNDER ALSO POSSIBLE
BUT POTENTIAL NOT GREAT ENOUGH TO INCLUDE AT THE MOMENT. CIGS WILL
LOWER AS SYSTEM PULLS AWAY AND NORTH WINDS INCREASE. CONFIDENCE
REMAINS LOW...BUT MOST LIKELY SCENARIO SEEMS TO BE JUST INTO IFR.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...SMALL
LONG TERM...FAB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
640 AM CDT Thu May 9 2013
.SHORT TERM...(Today through Saturday Afternoon)
Issued at 350 AM CDT THU MAY 9 2013
Conditions remain quiet early this morning as strong isentropic
lift and a veered LLJ have driven showers and thunderstorms into far
northeastern Missouri and southern Iowa. Regional radar and WV
imagery depict several developed MCV this morning, one located over
north central Kansas with two additional waves over northern and
eastern Oklahoma.
Through daybreak, short term guidance is in agreement that most of
the area will remain quiet as the vort max over north central Kansas
tracks northeast through the northwestern corner of Missouri. Have
lowered PoPs in most locations through daybreak. The stronger
southern MCV is now beginning to turn to the east as it enters
eastern Oklahoma. HRRR/RAP have struggled with this second wave, but
feel it will track into southern Missouri and gradually turn northeast
towards St. Louis after daybreak, perhaps tracking a little further
south than HRRR suggests.
Today: Subsidence in the wake of the MCV will prevent much in the
way of activity during the morning hours, and we may actually see
clouds scatter by late morning as a stationary boundary remains
draped over eastern Kansas and the northwestern third of Missouri.
Soundings indicate very low convective temperatures today, and by
late morning, we may already be approaching 70 in many areas.
Subsidence behind the departing wave will only last so long, as
stronger upper troughing remains over western Kansas. MLCAPE values
only approach 800-1000 J/KG, and shear remains marginal, thus only
anticipating a few small hail producing storms. The degree of heating
in the southeastern zones remains more questionable given the track
of the southern KS MCV this morning. Additional cloud cover and
stronger subsidence behind this wave in central Missouri may prevent
widespread redevelopment.
Thursday night-Friday: Surface troughing will push southeast
Thursday evening as upper troughing to the west begins to pivot
eastward and colder air aloft spills southward. Weak mid-level
frontogenesis may produce some lingering showers through the
overnight hours of Thursday. A north wind will prevail on Friday as
the front continues to push into southeastern Missouri and the upper
trough pivots overhead. Have lowered high temperatures a few degrees
due to the cloudy conditions and cold air advection aloft.
Temperatures may need to be lowered further in some areas.
Saturday: Weak surface ridging will slide through the area Friday
night before a much stronger cold front arrives on Saturday. Winds
will quickly turn northwest by late Saturday afternoon, turning
blustery. Temperatures will struggle to reach the lower 60s.
.LONG TERM...(Saturday Evening through Wednesday)
Issued at 350 AM CDT THU MAY 9 2013
Sunday - Tuesday:
This period will be characterized by dry weather an a marked warming
trend. Canadian high pressure will settle over the area by Sunday
morning making for a very cool start to the day. We will even flirt
with record lows (record low at MCI is 39 set in 1997). By Sunday
afternoon 850mb temps are only 2-6C which will yield highs only in
the upper 50s to lower 60s. On Monday upper level ridging that was
over the western Rockies on Sunday will begin to shift eastward into
the eastern Rockies and western Plains. This will provide for height
rises across the area. Couple that with surface high pressure
pushing off to the southeast and allowing for a return to southerly
flow and highs will rise into the upper 60s to mid 70s. By Tuesday
the upper level ridge axis moves over head. 850mb temperatures will
rise to 16-20C. And, with strong southwesterly winds providing for
good mixing, highs will be some of the warmest we have experienced
this season with highs in the low to mid 80s.
Wednesday:
Wednesday the upper level ridge will be shunted to the southeast as
an upper level trough digs into the Upper Midwest. This will send a
weak cold front into the area which will provide the next chance of
showers and thunderstorms. There is some question as to how much
moisture this system will have as the EC has a surface high pressure
over the Gulf Coast states keeping the Gulf closed. The GFS has high
pressure over the eastern Gulf with the western Gulf open and
moisture being transported into the area. Have maintained chance
POPs inherited by the initialization to account for the GFS solution.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 629 AM CDT THU MAY 9 2013
Scattered showers will linger this morning, as weak MCV rotates
through northwestern Missouri. Light winds at KMCI have allowed for a
slightly visibility restriction that will only last for an hour or
two.
Otherwise, VFR conditions will prevail for much of the daytime hours
as frontal boundary remains to the northwest of the major terminals.
As temperatures quickly warm later this morning, scattered showers
and thunderstorms may redevelop, however it will be nearly impossible
to pinpoint the timing and location of these storms in relation to
the terminals. Thus, will leave VCSH through the afternoon and
advertise thunder threat with a CB.
Dux
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...31
LONG TERM...73
AVIATION...Dux
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1130 AM EDT THU MAY 9 2013
.SYNOPSIS...
A SPRAWLING UPPER LEVEL LOW IN PENNSYLVANIA WILL DRIFT NORTHEAST
INTO NEW ENGLAND TODAY. A SLOW MOVING COLD FRONT WILL CROSS THE
REGION ON SATURDAY. THESE SYSTEMS WILL KEEP THE CHANCE FOR SHOWERS
AND THUNDERSTORMS ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA TODAY TO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1130 AM UPDATE...JUST MINOR ADJUSTMENTS TO NEAR TERM GRIDS. WILL
KEEP THE MENTION OF POTNL FOR +RA THIS AFTN WITH ANY TSTA. PREV
BLO...
930 AM UPDATE...
UPR LOW CNTRD OVER NE PA MOVG NEWD TDA...WITH SVRL EMBEDDED VORT
LOBES ROTATING ARND IT. PROFILES FOR THIS AFTN SHOW GNRLY 200-400
J/KG WITH SLIGHTLY LOWER PWAT`S. RUC SUGGESTS THAT LOW LVL
CONVERGENCE ASSCD WITH EWD MOVG SFC TROF MAY COUPLE WITH AN AREA
OF ENHANCED UPR LVL DVRGNC ACRS CNTRL NY. ANY TSRA THAT DVLP
COULD DROP LCLY HEAVY RAINFALL. PREV BLO...
3 AM UPDATE...
QUIET EARLY MORNING WITH ONLY A FEW SHOWERS LEFT. SOME FOG FORMING
WITH SATURATED LOW LEVELS. UPPER LEVEL LOW IN SE PA WILL CONTINUE
NE INTO SRN NEW ENGLAND TODAY. WITH THE LOW WILL BE ANOTHER AREA
OF SHOWERS THAT WILL MOVE NNW INTO NE PA AND THE CATSKILLS THIS
MORNING THEN THE REST OF THE AREA THIS AFTN. WITH DAYTIME HEATING
THE SHOWERS WILL BECOME MORE WIDESPREAD. TSTORMS ARE POSSIBLE
MOSTLY THIS AFTN. THEY COULD HAVE HEAVY RAIN. WITH ANOTHER AREA OF
1INCH PLUS PWATS ISOLATED AREAS COULD GET AN INCH OR TWO OF RAIN.
THE HIGHEST RAIN AMOUNTS WILL AGAIN BE IN THE EAST. LITTLE
FLOODING PROBLEMS EXPECTED THOUGH WITH MOST LOCATIONS UNDER HALF
AN INCH.
LATE TONIGHT INTO EARLY FRIDAY MORNING A BREAK IN THE SHOWERS AS
THE UL LOW MOVES OFF. MORE FOG POSSIBLE WITH A WET GROUND. MORE
SHOWERS APPROACH FROM THE WEST BUT SHOULD STAY IN WRN PA AND WRN
NY UNTIL DAYLIGHT FRIDAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
3 AM UPDATE...
CONTINUED UNSETTLED...COOL AND WET. A SFC LOW AND WEAK UPPER LEVEL
TROF MOVES ENE FROM ILLINOIS TO NY FRIDAY TO SATURDAY. THE LOW
STRENGTHENS WITH TIME...WHILE AN UL JET COUPLET SET UP AS THE
SOUTHERN JET MOVES TOWARD THE MID ATLANTIC. AHEAD OF THE LOW AND
TRAILING COLD FRONT BETTER MOISTURE AND HIGH TEMPS IN THE L70S
MOVE IN. THIS WILL DESTABILIZE THE LOWER LEVELS AND THE SHORT
WAVES WILL ADD LIFT. WIND FIELDS INCREASE AND TURN WITH HEIGHT FOR
SOME SPEED AND DIRECTIONAL SHEAR. WINDS NOT STRONG BUT ENOUGH TO
KEEP SHOWERS AND THUNDERSTORMS GOING ONCE THEY FORM LATE MORNING
INTO THE AFTERNOON. LIFT IS MARGINAL WITH CAPE UNDER 500. WIND
WILL BE THE BIGGEST THREAT. SPC HAS PA IN A SLIGHT CHC OF SEVERE.
ANOTHER HALF INCH OF RAIN IS EXPECTED FRI AFTN AND EVE. WILL NEED
TO WATCH FOR ISOLATED FLASH FLOODING WITH THUNDERSTORMS.
FRIDAY NIGHT THE SFC LOW MOVES FROM LAKE ONTARIO TO QUEBEC BUT THE
TRAILING COLD FRONT DOES NOT MAKE MUCH PROGRESS UNTIL SATURDAY.
THE BEST CHC OF SHOWERS WILL BE SAT MIDDAY AND AFTN IN NE PA AND
THE CATSKILLS. POSSIBLY SOME THUNDERSTORMS WITH WEAK LIFT AND
INSTABILITY. SAT NGT THE SFC FRONT MOVES EAST AND DAYTIME HEATING
WILL WANE CAUSING THE DIURNAL SHOWERS TO DIE. POPS DROP FROM
LIKELY SAT TO LOW CHC SAT OVERNIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
4 PM WED UPDATE... A TRANSITIONAL PATN IS EXPECTED THIS PD...AS
GLOBAL MODEL/WPC CONSENSUS POINTS TO A FAIRLY AMPLIFIED ERN
CANADIAN/NERN CONUS TROUGH EARLY IN THE PD...FOLLOWED BY A
TEMPORARY FILLING OF THIS FEATURE...AND MORE ZONAL PROGRESSION BY
NEXT TUE-WED.
SENSIBLE WX-WISE...MUCH CHILLIER TEMPS ARE FORESEEN SUN-MON...WITH
SCTD WRAP-ARND -SHRA ANTICIPATED...WITHIN THE CYCLONIC FLOW
REGIME. IN FACT...SOME WET SNOW FLAKES ARE EVEN PSBL LATE SUN
NGT INTO EARLY MON...SPCLY OVER THE HIGHER TERRAIN. THE OTHER PSBL
HIGHLIGHT OF THIS PD IS PROBABLE FROST/FREEZE CONDS...BOTH SUN AND
MON NGTS...IF ANY CLEARING CAN DVLP.
TEMPS SHOULD MODERATE TUE-WED (BACK INTO THE 60S AND 70S)...AS THE
FLOW TURNS SWLY...AND HGTS BUILD OVER THE ERN CONUS. BY WED...AN
APPROACHING UPR-LVL WAVE AND SFC FRNT COULD TRIGGER SOME
SHWRS...AND THUS WE`VE ADDED CHC POPS AT THIS EARLY JUNCTURE.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
VARIABLE CONDITIONS EXISTS ACROSS THE TERMINALS THIS MORNING
RANGING FROM IFR TO VFR, DUE TO BOTH VSBYS/CIGS. BY MID MORNING
CONDITIONS WILL IMPROVE TO GENERALLY VFR WITH SHOWERS BECOMING MORE
NUMEROUS AS THE MORNING PROGRESSES UNDER THE UPPER LEVEL LOW. LATE
THIS AFTERNOON THE ACTIVITY WILL GRADUALLY DIMINISH AS THE UPPER
LEVEL FEATURE MOVES EAST OF THE AREA AND WITH THE LOSS OF DIURNAL
HEATING. OVERNIGHT THERE IS THE POTENTIAL FOR LOW CIGS AND VSBYS
TO DEVELOP AFTER 06Z ESPECIALLY IN THE SOUTHERN TIER.
WINDS GENERALLY 5 KNOTS OR LESS EARLY THIS MORNING EITHER E/SE OR
VARIABLE. S/SW WINDS LATER THIS MORNING 5-7 KNOTS BECOMING W/SW
THIS AFTERNOON THEN LIGHT THIS EVENING.
OUTLOOK...
FRI/SAT...MVFR PSBL...IN SCATTERED SHOWERS.
SUN/MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...TAC
SHORT TERM...TAC
LONG TERM...MLJ
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
931 AM EDT THU MAY 9 2013
.SYNOPSIS...
A SPRAWLING UPPER LEVEL LOW IN PENNSYLVANIA WILL DRIFT NORTHEAST
INTO NEW ENGLAND TODAY. A SLOW MOVING COLD FRONT WILL CROSS THE
REGION ON SATURDAY. THESE SYSTEMS WILL KEEP THE CHANCE FOR SHOWERS
AND THUNDERSTORMS ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA TODAY TO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
UPR LOW CNTRD OVER NE PA MOVG NEWD TDA...WITH SVRL EMBEDDED VORT
LOBES ROTATING ARND IT. PROFILES FOR THIS AFTN SHOW GNRLY 200-400
J/KG WITH SLIGHTLY LOWER PWAT`S. RUC SUGGESTS THAT LOW LVL
CONVERGENCE ASSCD WITH EWD MOVG SFC TROF MAY COUPLE WITH AN AREA
OF ENHANCED UPR LVL DVRGNC ACRS CNTRL NY. ANY TSRA THAT DVLP
COULD DROP LCLY HEAVY RAINFALL. PREV BLO...
3 AM UPDATE...
QUIET EARLY MORNING WITH ONLY A FEW SHOWERS LEFT. SOME FOG FORMING
WITH SATURATED LOW LEVELS. UPPER LEVEL LOW IN SE PA WILL CONTINUE
NE INTO SRN NEW ENGLAND TODAY. WITH THE LOW WILL BE ANOTHER AREA
OF SHOWERS THAT WILL MOVE NNW INTO NE PA AND THE CATSKILLS THIS
MORNING THEN THE REST OF THE AREA THIS AFTN. WITH DAYTIME HEATING
THE SHOWERS WILL BECOME MORE WIDESPREAD. TSTORMS ARE POSSIBLE
MOSTLY THIS AFTN. THEY COULD HAVE HEAVY RAIN. WITH ANOTHER AREA OF
1INCH PLUS PWATS ISOLATED AREAS COULD GET AN INCH OR TWO OF RAIN.
THE HIGHEST RAIN AMOUNTS WILL AGAIN BE IN THE EAST. LITTLE
FLOODING PROBLEMS EXPECTED THOUGH WITH MOST LOCATIONS UNDER HALF
AN INCH.
LATE TONIGHT INTO EARLY FRIDAY MORNING A BREAK IN THE SHOWERS AS
THE UL LOW MOVES OFF. MORE FOG POSSIBLE WITH A WET GROUND. MORE
SHOWERS APPROACH FROM THE WEST BUT SHOULD STAY IN WRN PA AND WRN
NY UNTIL DAYLIGHT FRIDAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
3 AM UPDATE...
CONTINUED UNSETTLED...COOL AND WET. A SFC LOW AND WEAK UPPER LEVEL
TROF MOVES ENE FROM ILLINOIS TO NY FRIDAY TO SATURDAY. THE LOW
STRENGTHENS WITH TIME...WHILE AN UL JET COUPLET SET UP AS THE
SOUTHERN JET MOVES TOWARD THE MID ATLANTIC. AHEAD OF THE LOW AND
TRAILING COLD FRONT BETTER MOISTURE AND HIGH TEMPS IN THE L70S
MOVE IN. THIS WILL DESTABILIZE THE LOWER LEVELS AND THE SHORT
WAVES WILL ADD LIFT. WIND FIELDS INCREASE AND TURN WITH HEIGHT FOR
SOME SPEED AND DIRECTIONAL SHEAR. WINDS NOT STRONG BUT ENOUGH TO
KEEP SHOWERS AND THUNDERSTORMS GOING ONCE THEY FORM LATE MORNING
INTO THE AFTERNOON. LIFT IS MARGINAL WITH CAPE UNDER 500. WIND
WILL BE THE BIGGEST THREAT. SPC HAS PA IN A SLIGHT CHC OF SEVERE.
ANOTHER HALF INCH OF RAIN IS EXPECTED FRI AFTN AND EVE. WILL NEED
TO WATCH FOR ISOLATED FLASH FLOODING WITH THUNDERSTORMS.
FRIDAY NIGHT THE SFC LOW MOVES FROM LAKE ONTARIO TO QUEBEC BUT THE
TRAILING COLD FRONT DOES NOT MAKE MUCH PROGRESS UNTIL SATURDAY.
THE BEST CHC OF SHOWERS WILL BE SAT MIDDAY AND AFTN IN NE PA AND
THE CATSKILLS. POSSIBLY SOME THUNDERSTORMS WITH WEAK LIFT AND
INSTABILITY. SAT NGT THE SFC FRONT MOVES EAST AND DAYTIME HEATING
WILL WANE CAUSING THE DIURNAL SHOWERS TO DIE. POPS DROP FROM
LIKELY SAT TO LOW CHC SAT OVERNIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
4 PM WED UPDATE... A TRANSITIONAL PATN IS EXPECTED THIS PD...AS
GLOBAL MODEL/WPC CONSENSUS POINTS TO A FAIRLY AMPLIFIED ERN
CANADIAN/NERN CONUS TROUGH EARLY IN THE PD...FOLLOWED BY A
TEMPORARY FILLING OF THIS FEATURE...AND MORE ZONAL PROGRESSION BY
NEXT TUE-WED.
SENSIBLE WX-WISE...MUCH CHILLIER TEMPS ARE FORESEEN SUN-MON...WITH
SCTD WRAP-ARND -SHRA ANTICIPATED...WITHIN THE CYCLONIC FLOW
REGIME. IN FACT...SOME WET SNOW FLAKES ARE EVEN PSBL LATE SUN
NGT INTO EARLY MON...SPCLY OVER THE HIGHER TERRAIN. THE OTHER PSBL
HIGHLIGHT OF THIS PD IS PROBABLE FROST/FREEZE CONDS...BOTH SUN AND
MON NGTS...IF ANY CLEARING CAN DVLP.
TEMPS SHOULD MODERATE TUE-WED (BACK INTO THE 60S AND 70S)...AS THE
FLOW TURNS SWLY...AND HGTS BUILD OVER THE ERN CONUS. BY WED...AN
APPROACHING UPR-LVL WAVE AND SFC FRNT COULD TRIGGER SOME
SHWRS...AND THUS WE`VE ADDED CHC POPS AT THIS EARLY JUNCTURE.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
VARIABLE CONDITIONS EXISTS ACROSS THE TERMINALS THIS MORNING
RANGING FROM IFR TO VFR, DUE TO BOTH VSBYS/CIGS. BY MID MORNING
CONDITIONS WILL IMPROVE TO GENERALLY VFR WITH SHOWERS BECOMING MORE
NUMEROUS AS THE MORNING PROGRESSES UNDER THE UPPER LEVEL LOW. LATE
THIS AFTERNOON THE ACTIVITY WILL GRADUALLY DIMINISH AS THE UPPER
LEVEL FEATURE MOVES EAST OF THE AREA AND WITH THE LOSS OF DIURNAL
HEATING. OVERNIGHT THERE IS THE POTENTIAL FOR LOW CIGS AND VSBYS
TO DEVELOP AFTER 06Z ESPECIALLY IN THE SOUTHERN TIER.
WINDS GENERALLY 5 KNOTS OR LESS EARLY THIS MORNING EITHER E/SE OR
VARIABLE. S/SW WINDS LATER THIS MORNING 5-7 KNOTS BECOMING W/SW
THIS AFTERNOON THEN LIGHT THIS EVENING.
OUTLOOK...
FRI/SAT...MVFR PSBL...IN SCATTERED SHOWERS.
SUN/MON...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...
SHORT TERM...TAC
LONG TERM...MLJ
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1155 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL DRIFT SLOWLY NORTHEAST INTO THE
CATSKILL REGION OF SOUTHEASTERN NEW YORK LATER TODAY. WEAK HIGH
PRESSURE WILL BUILD EAST OVER THE COMMONWEALTH THIS AFTERNOON INTO
EARLY FRIDAY. MILDER...AND MORE HUMID AIR WILL PUSH INTO THE
REGION FRIDAY AFTERNOON THROUGH SATURDAY...AHEAD OF A STRONG COLD
FRONT THAT WILL BRING UNSEASONABLY COOL AIR TO THE REGION LATER IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER LOW...CENTERED OVER EASTERN PA EARLY TODAY WILL DRIFT
SLOWLY TO THE NE. HIGH RES SHORT RANGE MODELS HIGHLIGHT THE NW
QUAD OF THIS LOW FOR LOCALIZED ENHANCED PRECIP TODAY AS THE
SYSTEM LIFTS NORTHEAST AND MUCH OF THE REGION COMES UNDER THE AREA
OF STRONG FRONTOGENETIC FORCING IN THE BACK-SIDE DEFORMATION ZONE.
RAIN IS ALREADY FALLING IN A LOOSELY ORGANIZED BAND FROM THE LOWER
SUSQ VALLEY NNW UP INTO SWRN NY STATE. RUC SHOWS THE BEST FGEN
FORCING FOCUSING OVER THE AREA OF THE FLASH FLOOD WATCH INTO THE
AFTERNOON...WHILE ALSO GENERATING SOME MODEST AMOUNT OF
INSTABILITY UNDER THE CHILLY TEMPS ALOFT.
EXPECT THE RAIN TO CONTINUE THROUGH THE MID TO LATE MORNING HOURS
WITH AN AVERAGE OF 1-3 TENTHS OF RAINFALL.
FROM EARLIER...
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL
NARROW/QUASI STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA
SETTING UP ON A NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE
WEST AND SW OF THE DEPARTING UPPER LOW. A NARROW RIBBON OF
RELATIVELY HIGHER PWAT AIR /JUST OVER AND INCH/ WILL BE SHIFTING
SLOWLY EAST FROM THE ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ
VALLEY BY EARLY THIS EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CATEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENESIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLOOD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
A STORM SYSTEM WILL CONTINUE TO LIFT SLOWLY INTO NEW ENGLAND
THROUGH FRIDAY. BANDS OF SHOWERS ROTATING ABOUT THIS LOW WILL
CONTINUE THROUGH THE AFTERNOON. THE SHOWERS WILL BE MAINLY LIGHT
THROUGH THE MORNING HOURS...BUT AS THE ATMOSPHERE BECOMES MORE
UNSTABLE...HEAVIER SHOWERS AND ISOLATED THUNDERSTORMS WILL BECOME
POSSIBLE.
EXPECT MVFR/IFR SLOWLY LIFTING WITH MOST SITES BEING VFR BY MID TO
LATE DAY...BUT WITH LOCAL REDUCTIONS LIKELY IN THE HEAVIER SHOWERS
AND THUNDERSTORMS.
AS THE LOW MOVES TO THE NORTHEAST THE SHOWERS AND THUNDERSTORMS
WILL TAPER OFF AND SKIES WILL BEGIN TO CLEAR TONIGHT AS WEAK HIGH
PRESSURE BUILDS OVER THE COMMONWEALTH BRINGING MOSTLY VFR FLYING
CONDITIONS. AREAS OF FOG WILL BECOME POSSIBLE...ESPECIALLY WHERE
RAIN FALLS THIS AFTERNOON AND EVENING.
.OUTLOOK...
FRI...SCT SHOWERS AND PERHAPS A THUNDERSTORM LATE ACCOMPANIED BY
LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH A COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
MON...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ006-012-
037-041-045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...MARTIN
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1019 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE CENTERED WILL DRIFT SLOWLY NORTHEAST
INTO THE CATSKILL REGION OF SOUTHEASTERN NEW YORK LATER TODAY.
WEAK HIGH PRESSURE WILL BUILD EAST OVER THE COMMONWEALTH THIS
AFTERNOON INTO EARLY FRIDAY. MILDER...AND MORE HUMID AIR WILL PUSH
INTO THE REGION FRIDAY AFTERNOON THROUGH SATURDAY...AHEAD OF A
STRONG COLD FRONT THAT WILL BRING UNSEASONABLY COOL AIR TO THE
REGION LATER IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER LOW...CENTERED OVER EASTERN PA EARLY TODAY WILL DRIFT
SLOWLY TO THE NE. HIGH RES SHORT RANGE MODELS HIGHLIGHT THE NW
QUAD OF THIS LOW FOR LOCALIZED ENHANCED PRECIP TODAY AS THE
SYSTEM LIFTS NORTHEAST AND MUCH OF THE REGION COMES UNDER THE AREA
OF STRONG FRONTOGENETIC FORCING IN THE BACK-SIDE DEFORMATION ZONE.
RAIN IS ALREADY FALLING IN A LOOSELY ORGANIZED BAND FROM THE LOWER
SUSQ VALLEY NNW UP INTO SWRN NY STATE. RUC SHOWS THE BEST FGEN
FORCING FOCUSING OVER THE AREA OF THE FLASH FLOOD WATCH INTO THE
AFTERNOON...WHILE ALSO GENERATING SOME MODEST AMOUNT OF
INSTABILITY UNDER THE CHILLY TEMPS ALOFT.
EXPECT THE RAIN TO CONTINUE THROUGH THE MID TO LATE MORNING HOURS
WITH AN AVERAGE OF 1-3 TENTHS OF RAINFALL.
FROM EARLIER...
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL
NARROW/QUASI STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA
SETTING UP ON A NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE
WEST AND SW OF THE DEPARTING UPPER LOW. A NARROW RIBBON OF
RELATIVELY HIGHER PWAT AIR /JUST OVER AND INCH/ WILL BE SHIFTING
SLOWLY EAST FROM THE ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ
VALLEY BY EARLY THIS EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CATEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENESIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLOOD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
A LOW PRESSURE SYSTEM MOVING THROUGH PA IS FORECAST TO SLOWLY
LIFT NORTHEAST INTO NEW ENGLAND THROUGH FRIDAY. SCATTERED SHOWERS
MOVING AROUND THIS LOW WILL CONTINUE THROUGH THE MORNING AND
AFTERNOON. THE SHOWERS WILL BE MAINLY LIGHT THROUGH THE MORNING
HOURS...INTENSIFYING BY LATE MORNING AND AFTERNOON DUE TO
CONVECTION. DUE TO THE COPIOUS MOISTURE...EXPECT PATCHY
FOG/MIST...ESPECIALLY AT MDT AND LNS AND REGIONS WHERE MORE
WIDESPREAD PRECIPITATION FELL YESTERDAY...THROUGH 14Z. EXPECT
MVFR/IFR...WITH SOME SITES POTENTIALLY REACHING LIFR...VSBYS THIS
MORNING. ANY FOG/MIST WILL LIFT/DISSIPATE BY MID MORNING...WITH
SHOWERS CONTINUING AND THUNDERSTORMS POSSIBLE IN AFTERNOON. IFR
CIGS AND VSBYS ARE POSSIBLE IN AND AROUND THUNDERSTORM
ACTIVITY...WHERE THE HIGHEST PROBABILITIES WILL BE AT UNV AND IPT
TAF SITES.
AS THE LOW MOVES TO THE NORTHEAST THE SHOWERS AND THUNDERSTORMS
WILL TAPER OFF AND SKIES WILL BEGIN TO CLEAR TONIGHT AS WEAK HIGH
PRESSURE BUILDS OVER THE COMMONWEALTH BRINGING MOSTLY VFR FLYING
CONDITIONS.
.OUTLOOK...
FRI...COLD FRONT MOVES THROUGH. SCT SHOWERS AND PERHAPS A
THUNDERSTORM LATE ACCOMPANIED BY LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH ANOTHER COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR PAZ006-012-
037-041-045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...MARTIN
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE CENTERED WILL DRIFT SLOWLY NORTHEAST
INTO THE CATSKILL REGION OF SOUTHEASTERN NEW YORK LATER TODAY.
WEAK HIGH PRESSURE WILL BUILD EAST OVER THE COMMONWEALTH THIS
AFTERNOON INTO EARLY FRIDAY. MILDER...AND MORE HUMID AIR WILL PUSH
INTO THE REGION FRIDAY AFTERNOON THROUGH SATURDAY...AHEAD OF A
STRONG COLD FRONT THAT WILL BRING UNSEASONABLY COOL AIR TO THE
REGION LATER IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER LOW...CENTERED OVER EASTERN PA EARLY TODAY WILL DRIFT
SLOWLY TO THE NE TODAY. HIGH RES SHORT RANGE MODELS HIGHLIGHT THE
NW QUAD OF THIS LOW FOR ENHANCED PRECIP TODAY AS THE SYSTEM LIFTS
NORTHEAST AND MUCH OF THE REGION COMES UNDER THE AREA OF BEST
FRONTOGENETIC FORCING IN THE BACK-SIDE DEFORMATIONS ZONE.
RAIN IS ALREADY FALLING IN A LOOSELY ORGANIZED BAND FROM THE LOWER
SUSQ VALLEY NNW UP INTO SWRN NY STATE. RUC SHOWS THE BEST FGEN
FORCING FOCUSING OVER THE AREA OF THE FLASH FLOOD WATCH INTO THE
AFTERNOON...WHILE ALSO GENERATING SOME MODEST AMOUNT OF
INSTABILITY UNDER THE CHILLY TEMPS ALOFT.
EXPECT THE RAIN TO CONTINUE THROUGH THE MID TO LATE MORNING HOURS
WITH AN AVERAGE OF 1-3 TENTHS OF RAINFALL.
FROM EARLIER...
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL
NARROW/QUASI STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA
SETTING UP ON A NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE
WEST AND SW OF THE DEPARTING UPPER LOW. A NARROW RIBBON OF
RELATIVELY HIGHER PWAT AIR /JUST OVER AND INCH/ WILL BE SHIFTING
SLOWLY EAST FROM THE ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ
VALLEY BY EARLY THIS EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CATEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENESIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLOOD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A LOW PRESSURE SYSTEM MOVING THROUGH PA IS FORECAST TO SLOWLY
LIFT NORTHEAST INTO NEW ENGLAND THROUGH FRIDAY. SCATTERED SHOWERS
MOVING AROUND THIS LOW WILL CONTINUE THROUGH THE MORNING AND
AFTERNOON. THE SHOWERS WILL BE MAINLY LIGHT THROUGH THE MORNING
HOURS...INTENSIFYING BY LATE MORNING AND AFTERNOON DUE TO
CONVECTION. DUE TO THE COPIOUS MOISTURE...EXPECT PATCHY
FOG/MIST...ESPECIALLY AT MDT AND LNS AND REGIONS WHERE MORE
WIDESPREAD PRECIPITATION FELL YESTERDAY...THROUGH 14Z. EXPECT
MVFR/IFR...WITH SOME SITES POTENTIALLY REACHING LIFR...VSBYS THIS
MORNING. ANY FOG/MIST WILL LIFT/DISSIPATE BY MID MORNING...WITH
SHOWERS CONTINUING AND THUNDERSTORMS POSSIBLE IN AFTERNOON. IFR
CIGS AND VSBYS ARE POSSIBLE IN AND AROUND THUNDERSTORM
ACTIVITY...WHERE THE HIGHEST PROBABILITIES WILL BE AT UNV AND IPT
TAF SITES.
AS THE LOW MOVES TO THE NORTHEAST THE SHOWERS AND THUNDERSTORMS
WILL TAPER OFF AND SKIES WILL BEGIN TO CLEAR TONIGHT AS WEAK HIGH
PRESSURE BUILDS OVER THE COMMONWEALTH BRINGING MOSTLY VFR FLYING
CONDITIONS.
.OUTLOOK...
FRI...COLD FRONT MOVES THROUGH. SCT SHOWERS AND PERHAPS A
THUNDERSTORM LATE ACCOMPANIED BY LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH ANOTHER COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR PAZ006-012-037-041-
045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
753 AM EDT THU MAY 9 2013
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE CENTERED ACROSS THE LOWER SUSQUEHANNA
VALLEY EARLY TODAY WILL DRIFT SLOWLY NORTHEAST INTO THE CATSKILL
REGION OF SOUTHEASTERN NEW YORK LATER TODAY. WEAK HIGH PRESSURE WILL
BUILD EAST OVER THE COMMONWEALTH THIS AFTERNOON INTO EARLY FRIDAY.
MILDER...AND MORE HUMID AIR WILL PUSH INTO THE REGION FRIDAY
AFTERNOON THROUGH SATURDAY...AHEAD OF A STRONG COLD FRONT THAT WILL
BRING UNSEASONABLY COOL AIR TO THE REGION LATER IN THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SLOWLY WEAKENING UPPER LOW...CENTERED OVER THE MIDDLE SUSQ VALLEY
AT 09Z WILL DRIFT SLOWLY TO THE NE TODAY. 08/21Z AND 09/03Z SREF...
AND THE LATEST HRRR GUIDANCE INDICATES THAT THE CURRENT...
SLOWLY EXPANDING AREA OF SHOWERS ACRS THE CENTRAL AND NRN MTNS
WILL CONTINUE TO SPREAD SOUTH AND EAST THROUGH THE MID TO LATE
MORNING HOURS /TWD THE KIPT...KSEG AND KMDT AREAS/. EXPECT AN
AVERAGE OF 1-3 TENTHS OF RAINFALL WITH SOME LOCALLY HEAVIER
AMOUNTS POSSIBLE BETWEEN 09Z-14Z. THE BULK OF THE SHOWERS
THROUGH 14Z SHOULD STAY JUST TO THE WEST AND SOUTH OF KIPT...
AND ALSO JUST NORTH OF KAOO.
WET GROUND OVR MUCH OF THE AREA...COMBINED WITH A NEARLY CALM WIND
AND A FEW BREAKS IN THE OVERCAST...SHOULD RESULT IN AREAS OF FOG
THROUGH THE MID MORNING HOURS. LOW TEMPS AROUND DAYBREAK SHOULD
RANGE FROM THE U40S ACROSS THE ALLEGHENY PLATEAU...TO THE L50S
ELSEWHERE.
DURING THE LATE MORNING AND AFTERNOON HOURS...WILL BE CLOSELY
MONITORING HIGH RES MODEL AND RADAR TRENDS FOR POTENTIAL NARROW/QUASI
STNRY BANDS OF HEAVY SHOWERS AND LOW-TOPPED TSRA SETTING UP ON A
NW-SE AXIS IN THE WELL ALIGNED NW FLOW JUST TO THE WEST AND SW OF
THE DEPARTING UPPER LOW. A NARROW RIBBON OF RELATIVELY HIGHER PWAT
AIR /JUST OVER AND INCH/ WILL BE SHIFTING SLOWLY EAST FROM THE
ALLEGHENIES...TO THE CENTRAL MTNS AND SUSQ VALLEY BY EARLY THIS
EVENING.
MIXED LAYER...MU CAPE VALUES THIS RAMP UP TO 500-900 J/KG DURING THE
MIDDAY AND AFTERNOON HOURS /WITH HIGHER CAPES OF 1000-1500 J/KG
LIKELY DEVELOPING ACROSS SWRN PENN AND INTO THE LAUREL HIGHLANDS.
THIS THIN CAPE WILL ALLOW PARCELS TO ASCEND TO 5-8 KFT ABOVE THE
-20C LEVEL LEADING TO SOME LOW-TOPPED TSRA WITH SMALL HAIL AS THE
WET BULB ZERO LEVEL WILL BE VERY LOW...AND ONLY AROUND 7 KFT AGL.
POPS TODAY WILL BE NEAR 100 PERCENT FOR MUCH OF CENTRAL AND NRN
PA...WITH SURROUNDING AREAS IN THE LIKELY CATEGORY FOR SHOWERS AND
SCATTERED TSRA GIVEN THE ABOVE FACTORS. ALTHOUGH BASIN AVERAGE
RAINFALL TODAY WILL BE JUST A TENTH TO ONE QUARTER OF AN INCH IN
MANY LOCATIONS...THERE WILL LIKELY BE A FEW NARROW BANDS OF HEAVY
RAINFALL EXCEEDING ONE INCH ONCE AGAIN TODAY.
PINNING DOWN THE EXACT LOCATION OF THESE MESOSCALE FEATURES IS
QUITE DIFFICULT...BUT HIGH RES MODEL LOW-MID LEVEL FRONTOGENEISIS
AND MOISTURE CONVERGENCE INDICATES THE BEST CHANCE FOR HEAVIER
RAINFALL WILL BE ACROSS THE NCENT MTNS AND SUSQ VALLEY...IN CLOSE
PROXIMITY TO WHERE WE HAD LOCALLY OVER 2 INCHES WEDNESDAY. AS A
RESULT...A FLASH FLOOD WATCH WAS POSTED FOR TODAY /14Z-00Z FRIDAY
FOR 11 COUNTIES IN THE AFOREMENTIONED AREA OF HEAVY RAIN/.
DESPITE BREAKS OF SUNSHINE CLOUDS SHOULD PREDOMINATE TODAY. MDL 8H
TEMPS ARND 9C ARE SUPPORTIVE OF HIGHS FROM THE U60S ACROSS THE
ALLEGHENIES...TO THE L-M70S OVR THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT WILL SEE A STEADILY DECREASING TREND IN THE SHOWERS EARLY
ON...FOLLOWED BY SOME PARTIAL CLEARING AND LIGHT WIND LEADING TO THE
LIKELIHOOD OF FAIRLY WIDESPREAD FOG. MIN TEMPS WILL BE IN THE MID
40S TO LOWER 50S.
FRIDAY WILL SEE A RETURN OF MOISTURE AND WARMER TEMPS AS A DEEP
SWRLY FLOW DEVELOPS AHEAD OF A SLOW-MOVING/DYING COLD FRONT HEADING
EAST FORM THE OHIO VALLEY. 0-3KM HELICITY PEAKS BETWEEN 150 AND 250
M2/S2 FRIDAY AFTERNOON NEAR AND JUST TO THE SOUTH OF A WARM FRONT
AND SSWRLY 850 MB JET OF 30-35 KTS. POCKETS OF ML MU CAPE EXCEEDING
1500 J/KG WILL DEVELOPS IN WARMER AND MORE HUMID AIR MASS...AND
ACROSS THE FAR NW FRIDAY AFTERNOON /THEN OVER THE FAR SE TWD 00Z
SAT/...0-1KM EHI VALUES ARE EXPECTED TO RISE TO BETWEEN 1-1.5 MS/S2
SUPPORTING ROTATING UPDRAFTS IN SOME OF THE TSRA. SPC/S DAY 2
OUTLOOK TARGETS MUCH OF THE CWA FOR A SLIGHT RISK OF SVR.
THE BIG QUESTION/UNCERTAINTY...AS USUAL...SURROUNDING THE EXTENT OF
THE SVR THREAT FRIDAY AFTERNOON AND EVENING WILL BE THE AMOUNT OF
SUNSHINE/INSTABILITY THAT WILL FORM IN THE WARM SECTOR JUST AHEAD OF
THE INCREASING LARGE SCALE FORCING AND APPROACHING SFC
CFRONT.
HIGH TEMPS FRIDAY WILL RANGE FROM AROUND 70F ACROSS THE NW MTNS...TO
A BALMY 75-80 DEGREES FROM THE CENTRAL MTNS...SE TO THE LOWER SUSQ
VALLEY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE FOR FRIDAY NIGHT INTO SAT NIGHT. SERIES OF
COLD FRONTS MOVE ACROSS. ONE FRONT EARLY SAT...THEN ANOTHER
SATURDAY NIGHT. THE REAL COLD AIR WILL COME IN LATER
SUNDAY...BEHIND THE UPPER LVL FRONT. NEAR RECORD COLD LIKELY FROM
LATE SUNDAY INTO TUE AM. FROST AND FREEZE ISSUES WILL BE LIKELY.
AS THE HIGH MOVES TO TH SE LATE TUE...MODELS SHOW A STRONG
WESTERLY FLOW OF VERY WARM AIR FOR WED INTO THU... BEFORE ANOTHER
COLD SPELL LATER IN THE WEEK. PATTERN SUPPORT STRONG TO SEVERE
STORMS POSSIBLE WITH WARM FRONT...DID PUT LOW POPS IN ALONG THE NY
BORDER.
DID NOT GO TO CRAZY WITH MAX TEMPS AT THIS POINT...BUT COULD SEE
SOME MID 80S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A LOW PRESSURE SYSTEM MOVING THROUGH PA IS FORECAST TO SLOWLY
LIFT NORTHEAST INTO NEW ENGLAND THROUGH FRIDAY. SCATTERED SHOWERS
MOVING AROUND THIS LOW WILL CONTINUE THROUGH THE MORNING AND
AFTERNOON. THE SHOWERS WILL BE MAINLY LIGHT THROUGH THE MORNING
HOURS...INTENSIFYING BY LATE MORNING AND AFTERNOON DUE TO
CONVECTION. DUE TO THE COPIOUS MOISTURE...EXPECT PATCHY
FOG/MIST...ESPECIALLY AT MDT AND LNS AND REGIONS WHERE MORE
WIDESPREAD PRECIPITATION FELL YESTERDAY...THROUGH 14Z. EXPECT
MVFR/IFR...WITH SOME SITES POTENTIALLY REACHING LIFR...VSBYS THIS
MORNING. ANY FOG/MIST WILL LIFT/DISSIPATE BY MID MORNING...WITH
SHOWERS CONTINUING AND THUNDERSTORMS POSSIBLE IN AFTERNOON. IFR
CIGS AND VSBYS ARE POSSIBLE IN AND AROUND THUNDERSTORM
ACTIVITY...WHERE THE HIGHEST PROBABILITIES WILL BE AT UNV AND IPT
TAF SITES.
AS THE LOW MOVES TO THE NORTHEAST THE SHOWERS AND THUNDERSTORMS
WILL TAPER OFF AND SKIES WILL BEGIN TO CLEAR TONIGHT AS WEAK HIGH
PRESSURE BUILDS OVER THE COMMONWEALTH BRINGING MOSTLY VFR FLYING
CONDITIONS.
.OUTLOOK...
FRI...COLD FRONT MOVES THROUGH. SCT SHOWERS AND PERHAPS A
THUNDERSTORM LATE ACCOMPANIED BY LOCAL MVFR CONDITIONS.
SAT...MORE SHOWERS POSSIBLE WITH ANOTHER COLD FRONT.
SUN...SHOWERS EARLY...THEN IMPROVING CONDITIONS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR PAZ006-012-037-041-
045-046-049>052-056-057-063.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1042 AM CDT THU MAY 9 2013
.UPDATE...
CONVECTIVE COMPLEX CONTINUES TO DEVELOP IN THE CONCHO
VALLEY...MOVING NORTHEAST INTO NORTH AND CENTRAL TEXAS. SMALL HAIL
HAS BEEN REPORTED WITH THE STRONGER STORMS IN THE CONCHO VALLEY
BUT THE STORMS CONTINUE TO REMAIN BELOW SEVERE LIMITS FOR NOW.
A COMPLICATED CONVECTIVE EVOLUTION IS EXPECTED TODAY WITH TWO OR
THREE COMPLEXES/ROUNDS OF STORMS LIKELY TO AFFECT THE REGION
THROUGH TONIGHT. ANALYZING THE LATEST HI-RES AND SHORT TERM MODEL
DATA...LATEST THINKING IS NOT TOO FAR OFF FROM THE PREVIOUS
FORECAST. THE ONGOING COMPLEX OF STORMS WILL CONTINUE TO MOVE
NORTHEAST WITH ADDITIONAL CONVECTIVE DEVELOPMENT AS WE APPROACH
THE MIDDAY AND EARLY AFTERNOON HOURS. THIS MCS WILL LARGELY AFFECT
THE SOUTH AND SOUTHWESTERN HALVES OF THE CWA. IT IS POSSIBLE THAT
AN ADDITIONAL COMPLEX OF STORMS COULD DEVELOP OFF THIS INITIAL
COMPLEX THIS AFTERNOON. SEVERE STORMS EMBEDDED WITHIN THE MCS ARE
LIKELY...BUT THE CLOUD COVER ACROSS THE REGION WILL PLAY A KEY
ROLE IN HOW WIDESPREAD THE SEVERE STORMS ARE THIS AFTERNOON. AMPLE
MOISTURE IS ALREADY IN PLACE ACROSS THE REGION WITH STEEP LAPSE
RATES ABOVE THE MORNING CAP. THIS CAP IS EXPECTED TO WEAKEN
THROUGHOUT THE DAY AND IF BREAKS IN THE CLOUDS OCCUR THIS
AFTERNOON...INSTABILITY COULD JUMP TO OVER 3000 J/KG ACROSS THE
REGION...PER THE LATEST RAP SOUNDINGS. THIS WOULD INCREASE THE
SEVERE WEATHER POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS BEING
THE MAIN SEVERE WEATHER THREATS. THESE STORMS WILL GENERALLY MOVE
OFF TO THE EAST LATE THIS AFTERNOON AND EVENING.
THE OTHER FOCUS FOR STORM DEVELOPMENT THIS AFTERNOON IS ALONG THE
DRYLINE. THE DRYLINE IS CURRENTLY WELL TO OUR WEST IN FAR WEST
TEXAS BUT IS EXPECTED TO BULGE NEAR OUR NORTHWEST COUNTIES LATE
THIS AFTERNOON. MODELS CONTINUE TO DEVELOP STORMS ALONG THE
DRYLINE THIS AFTERNOON WITH A THREAT FOR SEVERE STORMS. SEVERAL OF
THE MODELS MERGE THE STORMS ALONG THE DRYLINE INTO A COMPLEX OF
STORMS THAT MOVES EAST/SOUTHEAST THIS EVENING AND TONIGHT. MAIN
SEVERE WEATHER THREATS WOULD ALSO BE LARGE HAIL AND DAMAGING WINDS
WITH THESE STORMS.
FOR THE UPDATE...ADJUSTED CLOUD COVER UP ACROSS THE REGION AND
LOWERED HIGH TEMPERATURES INTO THE LOW TO MID 70S ACROSS MOST OF
THE REGION. THE EXCEPTION WILL BE IN THE NORTHWEST WHERE
TEMPERATURES WILL LIKELY REACH THE LOWER 80S UNDER PARTLY CLOUDY
TO MOSTLY CLOUDY SKIES. ALSO INCREASED AND ADJUSTED POPS WITH THE
HIGHEST POPS STILL GENERALLY ALONG AND SOUTH OF INTERSTATE 20.
82/JLD
&&
.AVIATION...
THUNDERSTORMS ARE FIRING UP BETWEEN KSJT /SAN ANGELO/ AND KCOM
/COLEMAN/ AS A SHORTWAVE MOVES INTO WEST TEXAS. THESE STORMS WILL
MOVE EAST NORTHEAST AND INCREASE IN AREAL COVERAGE THIS MORNING.
CURRENT FORECAST TIMING BRINGS THE STORMS INTO THE I-35 AREA
15-17Z. LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH THESE
STORMS. IF THE COMPLEX MOVES THROUGH AS FORECAST...THE
THUNDERSTORM CHANCES SHOULD BE OVER 19-21Z AS THE AIRMASS SHOULD
STABILIZE FOR THE REST OF THE AFTERNOON BEHIND THE STORM COMPLEX.
THERE WILL BE ANOTHER CHANCE OF THUNDERSTORMS OVERNIGHT AS A COLD
FRONT MOVES INTO NORTH TEXAS. SOUTHERLY WINDS WILL PREVAIL
THROUGH TONIGHT AND AS THE COLD FRONT MOVES INTO THE METROPLEX
TAF SITES AFTER 12Z FRIDAY...WINDS WILL SHIFT TO THE NORTH OR
NORTHEAST AT 10 KNOTS OR LESS.
58
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT THU MAY 9 2013/
MORNING WATER VAPOR IMAGERY FEATURES SEVERAL SWIRLING VORTICES
ACROSS THE CONUS ALONG WITH A COUPLE OF COMPLEXES OF THUNDERSTORMS
AND A STEADY STREAM OF HIGH LEVEL PACIFIC MOISTURE VIA THE
SUBTROPICAL JET. OF IMPORTANCE TO NORTH TEXAS WEATHER OVER THE
NEXT 36 HOURS WILL BE THE LARGE BUT RATHER WEAK UPPER LOW OVER THE
SOUTHWEST US AND ITS ASSOCIATED EMBEDDED VORTICITY MAXIMA THAT
PERIODICALLY ROTATE AROUND AND EJECT EASTWARD. TIMING OF THESE
FEATURES AND THEIR ASSOCIATED FORCING FOR ASCENT WILL MAKE FOR A
MODERATELY CHALLENGING FORECAST THROUGH FRIDAY.
00Z MODEL DATA/UPPER AIR DATA AND WATER VAPOR IMAGERY CONFIRM THE
PRESENCE A SHORTWAVE WHICH IS CURRENTLY MOVING ACROSS NORTHWEST MEXICO
THIS MORNING. THIS IS A LITTLE FASTER THAN THE GUIDANCE SUGGESTED
FROM YESTERDAY. TIMING THIS FEATURE BASED ON ITS CURRENT SPEED WOULD
SUGGEST THAT THE STRONGEST FORCING FOR ASCENT ASSOCIATED WITH IT
WOULD BEGIN TO OVERSPREAD SOUTHWEST TEXAS SHORTLY AND SPREAD INTO
NORTH TEXAS THROUGH MID MORNING. MOST OF THE HIGH RESOLUTION
GUIDANCE QUICKLY DEVELOPS SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH LATE MORNING ACROSS THE EDWARDS PLATEAU AND SPREADS THEM
EAST-NORTHEAST INTO OUR CWA. THERE IS EVEN A STRONG SIGNAL WITHIN
THE LOWER RES GLOBAL GUIDANCE WHICH SUPPORTS THIS SCENARIO.
OBVIOUSLY WITH A MUCH EARLIER START TO CONVECTIVE ACTIVITY...THE
OVERALL SEVERE WEATHER THREAT WOULD BE LOWER...HOWEVER...DEEP
LAYER WIND FIELDS ARE QUITE A BIT STRONGER THIS MORNING THAN THEY
WILL BE BY THIS EVENING. FORECAST SOUNDINGS ACROSS THE CWA SHOW
THE CONTINUED PRESENCE OF STEEP MID LEVEL LAPSE RATES...AND WITH
AMPLE EFFECTIVE DEEP LAYER SHEAR...WOULD NOT RULE OUT INITIAL
ELEVATED SUPERCELL DEVELOPMENT THROUGH LATE MORNING. LARGE HAIL
WOULD BE THE PRIMARY THREAT DURING THIS TIME. THUNDERSTORMS THAT
DEVELOP THROUGH THE MORNING WOULD LIKELY TEND TO CLUSTER INTO AN
MCS AND SPREAD EAST OR SOUTHEASTWARD. UNFORTUNATELY THERE IS LARGE
SPREAD WITHIN THE GUIDANCE AS TO HOW FAR NORTH ANY SUCH COMPLEX OF
STORMS WOULD SPREAD...BUT CURRENT THINKING IS THAT BEST CHANCES
THROUGH THIS AFTERNOON WILL GENERALLY BE SOUTH OF INTERSTATE 20.
WILL HAVE HIGHEST POPS ACROSS THE SOUTHWEST COUNTIES THIS MORNING
AND SPREAD THEM ACROSS THE SOUTHERN AND SOUTHEAST THROUGH THIS EVENING.
ANOTHER AREA OF CONCERN FOR CONVECTIVE DEVELOPMENT WILL BE ALONG
THE FRONT/DRYLINE INTERSECTION ACROSS NORTHWEST TEXAS LATE THIS
AFTERNOON AND EVENING. THIS AREA APPEARS TO BE A LITTLE MORE
QUESTIONABLE AS MORNING/EARLY AFTERNOON CONVECTION WOULD LIKELY
INHIBIT ADDITIONAL DEVELOPMENT. WITH BEST FORCING FOR ASCENT
SPREADING ACROSS NORTH TEXAS DURING THE FIRST HALF OF THE
DAY...WEAK SUBSIDENCE WOULD LIKELY FOLLOW IN ITS WAKE...ESPECIALLY
IF AN ORGANIZED COMPLEX OF STORMS DEVELOPS FARTHER SOUTH. THAT
BEING SAID...FORECAST SOUNDINGS FOR LATE THIS AFTERNOON ACROSS
NORTHWEST TEXAS SHOW ONLY A WEAKLY CAPPED UNSTABLE PROFILE. THIS
WEAK CAPPING MAY BE THE MODELS FAILURE TO CAPTURE MORE ROBUST
SUBSIDENCE IN THE WAKE OF EARLIER CONVECTION. EITHER WAY...THE
HIGH RESOLUTION GUIDANCE VARIES ON THE DEVELOPMENT OF
THUNDERSTORMS THROUGH EARLY EVENING ACROSS NORTHWEST TEXAS
DEPENDING ON WHAT HAPPENS FARTHER SOUTH. GIVEN THAT THERE WILL BE
A FAIRLY LARGE UNPERTURBED AREA OF MODERATELY STRONG INSTABILITY
AND AT LEAST SOME FOCUSED LOW LEVEL FORCING ALONG THE
FRONT/DRYLINE AND POSSIBLY RESIDUAL OUTFLOW BOUNDARIES FROM EARLY
MORNING CONVECTION ACROSS OKLAHOMA...THINK AT LEAST ISOLATED SURFACE
BASED THUNDERSTORMS WILL DEVELOP BY THIS EVENING ACROSS PARTS OF
NORTHWEST TEXAS. A LOCALLY HIGHER SEVERE WEATHER THREAT WOULD
EXIST ACROSS OUR NORTHWEST COUNTIES WITH LARGE HAIL BEING THE MAIN
THREAT IF THESE STORMS DO DEVELOP.
AS THE COLD FRONT SAGS SOUTH LATER TONIGHT...RAIN AND THUNDERSTORM
CHANCES WILL PROGRESSIVELY SHIFT FARTHER SOUTH INTO CENTRAL TEXAS.
THE FRONT WILL LIKELY GET HUNG UP ACROSS THE HILL COUNTRY BY EARLY
FRIDAY MORNING. SCATTERED THUNDERSTORMS ARE AGAIN EXPECTED ALONG
THE FRONT WITH BEST CHANCES BEING ACROSS THE SOUTHERN COUNTIES.
WITH STEEP LAPSE RATES STILL IN PLACE ACROSS THIS AREA...SEVERE
HAIL WILL REMAIN A THREAT WITH THIS ACTIVITY. ACTIVITY TOMORROW
AFTERNOON SHOULD AGAIN DEVELOP INTO AN MCS AND HEAD SOUTHEAST OUT
OF THE AREA. FRONTAL BOUNDARY WOULD GET PUSHED FARTHER SOUTH BY
SATURDAY WITH POPS TAPERING BACK DOWN TO JUST 20 PERCENT ACROSS
THE SOUTHERN COUNTIES.
WITH THE MAIN UPPER LOW DRIFTING ACROSS NORTHWEST MEXICO OVER THE
WEEKEND...THERE SHOULD BE A FEW QUIET DAYS TO START NEXT WEEK. THE
UPPER LOW FINALLY GETS KICKED OUT BY MIDWEEK WITH ANOTHER SHOT OF
SHOWERS AND THUNDERSTORMS BY WEDNESDAY.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 76 66 79 59 77 / 90 60 20 20 10
WACO, TX 75 64 80 61 78 / 80 60 30 30 20
PARIS, TX 75 61 79 56 76 / 40 60 20 20 10
DENTON, TX 76 62 78 57 77 / 50 60 20 20 10
MCKINNEY, TX 75 62 78 57 78 / 60 60 20 20 10
DALLAS, TX 76 67 81 61 79 / 90 60 20 20 10
TERRELL, TX 77 63 80 58 78 / 70 60 20 20 10
CORSICANA, TX 75 65 80 61 77 / 80 60 30 30 20
TEMPLE, TX 75 64 80 60 76 / 80 60 50 30 20
MINERAL WELLS, TX 77 61 78 57 80 / 60 50 20 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
69/82
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST THU MAY 9 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE AREA WILL BRING A CHANCE
OF AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ESPECIALLY EAST
OF TUCSON THROUGH SATURDAY. EXPECT COOLER THAN NORMAL DAYTIME
TEMPERATURES THIS AFTERNOON AND FRIDAY. DRY CONDITIONS WITH A STRONG
WARMING TREND WILL THEN OCCUR SUNDAY THROUGH WEDNESDAY.
&&
.DISCUSSION...VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE CLEAR SKIES ACROSS SE AZ AT THIS TIME WITH THE EXCEPTION OF
A FEW CUMULOFORM CLOUDS IN THE VICINITY OF THE WHITE MOUNTAINS.
09/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS NEAR 0.65 INCH...
WHICH IS AN INCREASE OF NEARLY 0.15 INCH VERSUS 24 HOURS AGO.
BLENDED TOTAL PRECIP WATER IMAGERY PRODUCT VALID 1359Z YIELDED
VALUES RANGING FROM 0.45 INCH ACROSS MUCH OF COCHISE COUNTY TO
NEARLY 0.60 INCH ACROSS FAR WRN PIMA COUNTY.
UPPER LEVEL TROUGH AXIS EXTENDED FROM CENTRAL NEBRASKA SOUTHWESTWARD
ACROSS SRN UTAH...THEN WESTWARD INTO CENTRAL CALIFORNIA. AS THE
TROUGH AXIS MOVES SEWD LATER TODAY...DIFFLUENT FLOW ALOFT IN
COMBINATION WITH ADEQUATE MOISTURE SHOULD PRODUCE ISOLATED TO
SCATTERED SHOWERS ESPECIALLY ACROSS THE WHITE MOUNTAINS. THE 09/14Z
RUC HRRR PROGGED PRECIP ECHOES TO DEVELOP BY 19Z MAINLY ACROSS THE
CATALINA/GALIURO/PINALENO MOUNTAINS BETWEEN TUCSON AND SAFFORD. BY
MID AFTERNOON THE BULK OF CELLS AS PROGGED VIA THE RUC HRRR IS
EXPECTED TO BE ACROSS NRN GREENLEE/GRAHAM/NRN COCHISE COUNTIES.
AT ANY RATE...THE INHERITED OFFICIAL FORECAST DEPICTS A CHANCE OF
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING...MAINLY
ACROSS THE WHITE MOUNTAINS. THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND THIS EVENING MAINLY NEAR THE
MOUNTAINS OF GRAHAM AND COCHISE COUNTIES...AS WELL AS NEAR THE
CATALINA/RINCON MOUNTAINS JUST EAST OF TUCSON.
OTHERWISE...HIGH TEMPS THIS AFTERNOON WILL BE ABOUT 6-10 DEGS F
COOLER THAN NORMAL.
BASED ON RECEIPT OF THE 09/12Z NAM AND AFOREMENTIONED RUC HRRR...
SEE NO REASON TO MAKE ANY CHANGES TO THE OFFICIAL FORECAST AT THIS
TIME. PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION FOR ADDITIONAL
DETAIL.
&&
.PREV DISCUSSION /215 AM MST THU MAY 9 2013/...ON FRIDAY...MODELS
ARE SIMILAR WITH UPPER LOW OVER NORTHERN SONORA WITH PRECIPITABLE
WATER VALUES ARE PROGGED ACROSS THE AREA TO BE IN THE 0.50"-0.75"
RANGE. AFTERNOON/EVENING MID-LEVEL NE FLOW WILL BE IN THE 15-20 KT
RANGE...WHICH WILL BE ENOUGH TO SEE STORMS PROPAGATE OFF THE
MOUNTAINS INTO THE VALLEYS...ESPECIALLY IN THE EVENING. HAVE
INCREASED POPS FROM TUCSON EAST TO SHOW BETTER CONFIDENCE. MAIN
THREAT IN THE VALLEYS WILL BE GUSTY WINDS...UP TO 40 MPH...NEAR
STORMS AND BLOWING DUST.
SATURDAY...SOME DRIER AIR PUSHES IN THE FROM THE NORTHEAST WITH
UPPER LOW CENTERED OVER SOUTHERN SONORA MEXICO. THIS WILL RESULT IN
LESS AREAL COVERAGE IN STORMS FROM TUCSON EAST.
SUNDAY THROUGH TUESDAY...UPPER LOW MEANDERS OVER SOUTHERN SONORA.
ENOUGH RESIDUAL MOISTURE HANGING AROUND FOR A SLIGHT CHANCE OF
MAINLY MOUNTAIN STORMS. CONFIDENCE NOT OVERLY HIGH SO AT THIS TIME
KEPT POPS BELOW 10%...THUS NO MENTION IN THE ZONES.
WEDNESDAY...UPPER HIGH BUILDS OVER THE AREA.
TEMPERATURES WILL REMAIN PLEASANTLY COOL TODAY AND FRIDAY THEN
WARMUP COMMENCES IN EARNEST THIS WEEKEND WHICH WILL CONTINUE THROUGH
NEXT WEEK.
&&
.AVIATION...ISOLD-SCT -TSRA/-SHRA MAINLY FROM THE CATALINA AND
RINCON MOUNTAINS JUST EAST OF KTUS EASTWARD TO THE NEW MEXICO BORDER
THIS AFTERNOON AND THIS EVENING. BRIEF WIND GUSTS TO AROUND 40 KTS
MAY POTENTIALLY OCCUR NEAR THUNDERSTORMS. OTHERWISE...SKC THIS
MORNING BECOMING FEW-SCT CLOUDS AT 6-10K FT AGL THIS AFTERNOON AND
CONTINUING INTO THRU EARLY FRIDAY MORNING OR 10/12Z. SURFACE WIND
THIS AFTERNOON WLY/SWLY 10-18 KTS WITH GUSTS TO NEAR 25 KTS...
STRONGEST WIND EAST AND SOUTH OF KTUS. OTHERWISE...SURFACE WIND
GENERALLY LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A CHANCE OF AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS ESPECIALLY EAST OF TUCSON THROUGH SATURDAY. THERE
IS THE POTENTIAL FOR GUSTY WINDS ASSOCIATED WITH THUNDERSTORMS...
PARTICULARLY FRIDAY AFTERNOON AND FRIDAY EVENING...AS A LOW PRESSURE
SYSTEM MOVES SOUTHEAST OF THE AREA. FIELD CREWS ARE ENCOURAGED TO
MONITOR THE LATEST FORECASTS REGARDING THIS SCENARIO. OTHERWISE...
COOLER-THAN-NORMAL DAYTIME TEMPERATURES WILL PREVAIL THIS AFTERNOON
AND FRIDAY. GUSTY EAST TO SOUTHEAST WINDS ARE FORECAST ON SATURDAY.
HOWEVER...AT THIS TIME APPEARS THAT CRITICAL FIRE WEATHER THRESHOLDS
WILL NOT OCCUR. THEREAFTER...EXPECT DRY CONDITIONS SUNDAY THROUGH
WEDNESDAY WITH A STRONG WARMING TREND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
BF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
256 PM MDT THU MAY 9 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 247 PM MDT THU MAY 9 2013
ELONGATED UPPER LOW FROM SRN CA ACROSS THE 4 CORNERS TO ERN CO WAS
GETTING STRETCHED APART THIS AFTERNOON...AS THE EASTERN PORTION
MOVES INTO THE PLAINS WHILE THE WESTERN PORTION DROPS SOUTHWARD.
CONVECTION WAS A LITTLE SLOW GETTING GOING TODAY...BUT RECENT KGJX
RADAR SHOWED ECHOES BUILDING ALONG THE TAVAPUTS/ROAN PLATEAUS TO THE
FLATTOPS...AND OVER THE CENTRAL AND SOUTHERN MTNS. INSTABILITY
LIKELY THE DRIVING FORCE THOUGH RAP MODEL INDICATED SOME 700-500 MB
LAYER CONVERGENCE SOUTH OF I-70 AND UNDER THE DEFORMATION/UPPER LOW
AXIS ALOFT. ISOLATED THUNDERSTORMS WILL BE POSSIBLE WITH GUSTY WINDS
AND PERHAPS SOME GRAUPEL. WILL KEEP THE CURRENT WINTER HIGHLIGHTS
GOING THOUGH PRECIPITATION LIKELY TO BE QUITE VARIABLE GIVEN THE
CONVECTIVE NATURE OF THE SHOWERS.
THE DEFORMATION ZONE SINKS SOUTH OF OUR AREA THIS EVENING AND
TONIGHT. WITH ITS EXIT AND THE LOSS OF DAYTIME HEATING...EXPECT
SHOWERS TO DIMINISH BY LATE EVENING.
A SHORTWAVE DISTURBANCE DROPPING DOWN ACROSS WRN MT THIS AFTERNOON
WILL REACH OUR FORECAST AREA BY FRI MORNING. NE UT/NW CO SHOULD SEE
CLOUDS BACK ON THE INCREASE BY SUNRISE. WEAK MOISTURE TRANSPORT IN
THE NORTHERN FLOW ALONG THIS PASSING WEAK DISTURBANCE AND DAYTIME
INSTABILITY SHOULD TRIGGER A ROUND OF AFTERNOON SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS FRIDAY AFTERNOON...MAINLY OVER THE HIGHER
TERRAIN. SNOW WILL GENERALLY BE CONFINED TO ABOVE 9500-10K FT. HIGH
TEMPS FRIDAY WILL BE WARMER THAN TODAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 247 PM MDT THU MAY 9 2013
A HIGHLY AMPLIFIED PATTERN THROUGH THE WEEKEND FLATTENS EARLY NEXT
WEEK. THERE IS HIGH FORECAST CONFIDENCE THROUGH MONDAY...THEN MODELS
SHOW INCREASING SPREAD IN FORECAST DETAILS.
A POSITIVELY TILTED RIDGE AXIS AMPLIFIES FROM THE EASTERN PACIFIC
INTO THE NORTHERN ROCKIES. THEN SLOWLY PROGRESSES UNTIL IT IS
OVERHEAD ON MONDAY. A PORTION OF THE LOW PRESSURE SYSTEM THAT
BROUGHT SHOWERS ON WEDNESDAY INTO THURSDAY IS CUTOFF IN SONORA
MEXICO. NEAR NORMAL TEMPERATURES ON SATURDAY WILL RISE WELL ABOVE
NORMAL BY MONDAY. THE WARMING AFTERNOON TEMPERATURES AND MARGINAL
MOISTURE LOOK TO OVERCOME SUBSIDENCE ON SATURDAY FOR SCATTERED
MAINLY MOUNTAIN THUNDERSTORMS. INCREASING SUBSIDENCE ON SUNDAY AND
MONDAY WITH MOISTURE DIMINISHING DUE TO CONVECTIVE VENTILATION
DIMINISH THE CHANCES OF MOUNTAIN SHOWERS. MONDAY AFTERNOON
TEMPERATURES WILL RISE ABOUT 10 DEGREES ABOVE NORMAL.
ON MONDAY A TROUGH WORKS INTO BC-WASHINGTON AND LIFTS THROUGH THE
NORTHERN ROCKIES ON TUESDAY. THIS BREAKS DOWN THE LOCAL RIDGE AND
ALSO ENTRAINS THE SONORA LOW...BOTH OF WHICH MAY INCREASE DIURNAL
THUNDERSTORM COVERAGE FOR TUESDAY INTO WEDNESDAY. BY THURSDAY BOTH
THE EC AND GFS ARE DIGGING A SHALLOW TROUGH ALONG THE WEST COAST
THAT MAY THREATEN INCREASED SHOWERS TOWARDS THE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 247 PM MDT THU MAY 9 2013
SCATTERED TO NUMEROUS RAIN/SNOW SHOWERS OVER THE WRN CO AND SE UT
MTNS THIS AFTERNOON WILL DIMINISH THIS EVENING. ISOLATED
THUNDERSTORMS ARE POSSIBLE. STORM MOTION WILL BE TO THE WEST
SOUTHWEST AND POSSIBLY AFFECT THE WEST CENTRAL CO TAF SITES PRIOR TO
03Z. IN GENERAL...THOUGH...VFR CONDITIONS SHOULD BE PRESENT THROUGH
18Z FRI. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP
OVER THE HIGHER TERRAIN AGAIN FRI AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ009-
010-013-018-019.
WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ012.
UT...NONE.
&&
$$
SHORT TERM...JAD
LONG TERM...JOE
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1022 AM MDT THU MAY 9 2013
.UPDATE...
ISSUED AT 1022 AM MDT THU MAY 9 2013
LET THE DENSE FOG ADVISORY FOR THE CRAIG-HAYDEN AREAS EXPIRE AT 10
AM AS VISIBILITY AT THE ASOS SITES IMPROVED AND FOG DISSIPATED.
ELONGATED UPPER LOW REMAINS STRETCHED ACROSS SRN UT AND SRN CO
THIS MORNING. SNOW ACTIVITY APPEARS TO BE IN A BIT OF A LULL AT
MID-MORNING ESPECIALLY ACROSS THE NRN MTNS/FLATTOPS AND HAVE
KNOCKED DOWN POPS THERE FOR THE REST OF THIS MORNING. REGIONAL
RADAR SHOWED PRECIPITATION APPROACHING THE CONTINENTAL DIVIDE IN
EAST TO NORTHEAST FLOW...AND EXPECT CONVECTIVE SNOW SHOWER
ACTIVITY TO ALSO BEGIN INCREASING AT MIDDAY AS INSTABILITY STARTS
TO BE REALIZED WITH DAYTIME HEATING. HIGH RESOLUTION HRRR MODEL
PRECIP FAVORS THE SAN JUAN MTNS...CLOSEST TO THE UPPER
LOW/DEFORMATION AXIS ALOFT. THUS...NO CHANGES TO THE CURRENT
WINTER HIGHLIGHTS FOR MANY WRN CO MTNS THROUGH 6 PM THIS EVENING
THOUGH SNOW/RAIN AMOUNTS LIKELY TO BE QUITE VARIABLE DUE TO THE
SHOWERY NATURE OF THE PRECIPITATION.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 412 MDT THU MAY 9 2013
TODAY...THE QUASI-STATIONARY AND ELONGATED LOW PRESSURE SYSTEM
EXTENDING FROM THE CENTRAL PLAINS WEST-SOUTHWEST TO SOUTHERN
CALIFORNIA WILL CONTINUE TO IMPACT THE REGION TODAY. THE
DEFORMATION AXIS ASSOCIATED WITH THIS SYSTEM STRETCHED FROM THE
CENTRAL MOUNTAINS TO THE LA SAL MOUNTAINS IN SOUTHEAST UTAH EARLY
THIS MORNING WHERE PRECIPITATION WAS HEAVIEST. KASE OBSERVATIONS
SHOWED THE SNOW LEVEL HAD LOWERED TO NEAR THE 8 KFT MARK
OVERNIGHT BUT SHOULD REBOUND TO ABOVE 8500 FEET WITH AFTERNOON
WARMING. AS THE DAY PROGRESSES THIS BAND WILL SHIFT SOUTHWARD WITH
THE BEST SNOWFALL MOVING INTO THE SAN JUAN MOUNTAINS DURING THE
AFTERNOON. INSTABILITY WILL CONTINUE TO BRING SNOW TO THE REST OF
THE MOUNTAINS TODAY SO WILL NOT MAKE CHANGES TO GOING HILITES.
VALLEYS WILL SEE SHOWERS FROM TIME TO TIME WHICH WILL KEEP
TEMPERATURES BELOW NORMAL AND UNDERCUT MOS A BIT LIKE PREVIOUS
SHIFTS.
TONIGHT THROUGH SATURDAY...LARGE POLAR VORTEX OVER THE NORTHERN
CANADIAN TERRITORIES WILL KEEP HIGH LATITUDE ENERGY DIRECTED
INTO THE UPPER MID WEST AND EVENTUALLY CARVE OUT A FAIRLY DEEP
TROF OVER THE EASTERN CONUS BY SATURDAY AFTERNOON. WITH ANOTHER
STRONG LOW PRESSURE SYSTEM MOVING INTO THE NORTHEAST PACIFIC
THROUGH THIS TIME...HIGH AMPLITUDE RIDGING WILL EXPAND ACROSS MUCH
OF WESTERN NORTH AMERICA. THIS RIDGE WILL EVENTUALLY BE FOLDED
OVER THE ROCKIES AND BRING DRY AND MUCH WARMER WEATHER BY EARLY
NEXT WEEK. HOWEVER...BEFORE THIS OCCURS INSTABILITY AND WEAK
MOISTURE ADVECTION WILL KEEP UNSETTLED WEATHER IN PLACE OVER OUR
CWA.
BY THIS EVENING...LOW PRESSURE DROPPING INTO THE NORTHERN BAJA
REGION WILL HELP DRAW THE WEAKENING LOW PRESSURE OVER OUR AREA
BACK TO THE SOUTHWEST. ANY FORCING FROM THIS SHEARING LOW PRESSURE
AREA WILL BE REFOCUSED TO THE SOUTH WITH THE NEW ENERGY TO THE
WEST. THE RIDGE WILL TEMPORARILY BUILD IN FROM THE NORTH AS WELL
BUT WILL BE KNOCKED BACK TO THE WEST AS A VIGOROUS WAVE DROPS
THROUGH DEVELOPING TROF OVER THE NORTHERN PLAINS. THEREFORE...
EXPECT SHOWER ACTIVITY TO DROP OFF FAIRLY QUICKLY TOWARDS SUNSET
THIS EVENING WITH COOLER TEMPERATURES AND POSSIBLY SOME PATCHY FOG
FORMING UNDER CLEARING SKIES TOWARD MORNING. A VERY SUBTLE WAVE
WILL BE PUSHED THROUGH THE NORTHERLY FLOW DEVELOPING OVER THE
CENTRAL ROCKIES. WEAK INSTABILITY AND RESIDUAL MOISTURE WILL BE
SUFFICIENT TO SPARK AFTERNOON CONVECTION OVER THE HIGHER TERRAIN.
WEAK SHEAR AND MINIMAL MOISTURE ADVECTION SHOULD KEEP MOST OF THIS
ROOTED TO THE HIGHER ELEVATIONS WITH ONLY A FEW STRAY LIGHT
SHOWERS MOVING INTO THE VALLEYS. WITH RESIDUAL MOISTURE LINGERING
ACROSS THE REGION KEPT TEMPERATURES IN CHECK AND TOWARD THE
LOWER END OF GUIDANCE.
EXPECT THE SHOWERS TO AGAIN QUICKLY FADE BY SUNSET ON FRIDAY ONLY
TO REFORM ONCE AGAIN DURING THE HEATING OF THE DAY ON SATURDAY.
MOISTURE CONTINUES TO DWINDLE SO COVERAGE SHOULD AGAIN BE MORE
FOCUSED ON THE TERRAIN. MID LEVEL TEMPERATURES MAKE A FAIRLY GOOD
JUMP BY SATURDAY AFTERNOON WHICH SHOULD PUSH HIGHS CLOSER TO
NORMAL.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 412 MDT THU MAY 9 2013
MODELS SHOWED A STRONG RIDGE OF HIGH PRESSURE BUILDING OVER THE
WEST LATE IN THE WEEK RESULTING IN A STEADY INFLUX OF DRIER AIR
FROM THE NORTHWEST. CONSEQUENTLY...EXPECT LARGELY DIURNAL SHOWERS
AND THUNDERSTORMS TO DIMINISH BY EARLY SUNDAY MORNING WITH A FEW
REIGNITING ALONG THE CONTINENTAL DIVIDE SUNDAY AFTERNOON/EVENING.
FLOW BECOMES MORE ZONAL MONDAY AS THE RIDGE FLATTENS IN RESPONSE
TO A SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN ROCKIES. DAYTIME
HEATING WILL SPARK ANOTHER ROUND OF THUNDERSTORMS MONDAY
AFTERNOON/EVENING.
ECMWF AND GFS DIVERGE A LITTLE BIT TOWARD MIDWEEK WITH THE GFS
GENERATING A SHALLOW TROUGH OVER THE WEST WHILE THE EC FAVORED A
FLAT RIDGE. REGARDLESS...BOTH CONTINUED WITH DIURNAL SHOWER AND
THUNDERSTORM ACTIVITY BOTH TUESDAY AND WEDNESDAY.
TEMPERATURES WILL BE ABOVE NORMAL SUNDAY INTO MIDWEEK AS WARMER
AIR BENEATH THE RIDGE SWEEPS INTO THE AREA AND THEN LINGERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1022 AM MDT THU MAY 9 2013
IFR/MVFR CIGS AT KEGE/KASE/KMTJ FOLLOWING EARLY MORNING
PRECIPITATION LATE THIS MORNING SHOULD LIFT BY EARLY AFTERNOON AS
VALLEY MIXING OCCURS. VFR SHOULD THEN BE THE GENERAL CONDITION
EXPECTED AT THE TAF SITES THROUGH 03Z...THOUGH MVFR OR EVEN IFR
CONDITIONS WILL BE POSSIBLE FROM TIME TO TIME IN SHOWERS
ESPECIALLY AT KASE. EXPECT MTN TOPS TO BE FREQUENTLY OBSCURED THIS
AFTERNOON. IN ADDITION...ISOLATED THUNDERSTORMS WILL PRODUCE
STRONG...GUSTY AND ERRATIC OUTFLOW WINDS.
SHOWERS DIMINISH OVERNIGHT OVER MUCH OF THE AREA...THOUGH THE SAN
JUAN MOUNTAINS WILL CONTINUE TO SEE LOCALIZED LIGHT SNOW IN THE
HIGHER ELEVATIONS. LOW CLOUDS OR FOG MAY PRODUCE LOCALIZED
MVFR...OR IFR/LIFR VSBY AND CIGS IN THE CENTRAL COLORADO VALLEYS
AFTER MIDNIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR COZ009-
010-013-018-019.
WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ012.
UT...NONE.
&&
$$
UPDATE...JAD
SHORT TERM...NL/15
LONG TERM...NL
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS MIAMI FL
224 PM EDT THU MAY 9 2013
...CONTINUED LOW RISK OF ONE OR TWO STRONG-SEVERE TSTORMS SE FL
THROUGH EARLY THIS EVENING...
.DISCUSSION...FORMIDABLE ATLANTIC SEA BREEZE HAS DEVELOPED AND NOW
LIES WEST OF THE I-95 CORRIDOR IN PALM BEACH COUNTY AND ALONG AND
WEST OF THE FLORIDA TURNPIKE IN BROWARD AND MIAMI-DADE COUNTIES.
HUMIDITY IS DEFINITELY ON THE INCREASE SE OF THIS BOUNDARY WITH
DEWPOINTS NOW UP TO 70F AT MIA WITH A HEAT INDEX OF 91F. SO
DEFINITELY HOTTER AND MORE HUMID ACROSS THE EAST COAST METRO AREAS
TODAY. MESOANALYSIS SHOWS SURFACE BASED CAPE NOW REACHING
3500-4000 J/KG ALONG THE SE COAST. LATEST ACARS DATA SHOWS 500 MB
TEMP NOW AROUND -13.5C. HRRR CONTINUES TO INSIST ON CONVECTION
DEVELOPING AND FOCUSING OVER THE RURAL EASTERN INTERIOR. HOWEVER,
IF WE GET BIG STORMS TO DEVELOP, STORM MOTION VECTORS CONTINUE OUT
OF THE W-NW AT AROUND 10 KT, SO WE ANTICIPATE ANY THUNDERSTORMS
WHICH DEVELOP TO TRACK BACK TOWARDS THE ATLANTIC COAST. PEAK
OUTSIDE SHOWS A BUILDING CUMULUS SO IT LOOKS AS THOUGH THINGS WILL
START TO DEVELOP AND HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST INTO THIS EVENING. A FEW STRONG-SEVERE TSTORMS APPEAR
POSSIBLE GIVEN THE RECORD COLD AIR ALOFT (WHEN COMPARING DATA FROM
THE PAST 25 YEARS).
NO SIGNFICANT CHANGES WERE MADE TO THE FORECAST FOR FRIDAY AND
INTO THE UPCOMING WEEKEND AND BEYOND. MID/UPPER RIDGING GRADUALLY
BUILDS IN FROM THE SW WITH THE VERY COLD AIR ALOFT SHIFTING
NORTHEAST WITH WARMING TEMPS IN THE MID LEVELS. MOISTURE WILL
CONTINUE RATHER LIMITED WITH ACTUALLY FORECAST SOUNDINGS OFF THE
GFS SHOWING SLIGHT DRYING FRI-SAT. ALSO, A MORE SE WIND FLOW
PREDOMINATES AND THIS WILL LEAD TO ANY CONVECTION FOCUSING ACROSS
THE INTERIOR.
GFS CONTINUES TO SHOW A COLD FRONT MOVING ACROSS SOUTH FL LATE MON
INTO EARLY TUESDAY. MOISTURE WILL INCREASE AHEAD OF THIS FRONT
WITH BETTER PROSPECTS FOR SHOWERS AND THUNDERSTORMS MONDAY. DRIER
AND SLIGHTLY COOLER AIR, BUT NOTICEABLE GIVEN LOWERING HUMIDITY ON
AN INCREASINE EASTERLY BREEZE BY THE MIDDLE PART OF NEXT WEEK
BEHIND THE FRONT.
&&
.MARINE...LIGHT WINDS WITH SEAS BELOW 4 FT WILL CONTINUE THROUGH
THE WEEKEND. BEHIND THE COLD FRONT TUESDAY, WINDS WILL INCREASE
WITH WORSENING MARINE CONDITIONS THEN.
&&
.FIRE WEATHER...MIN RH`S OVER THE WESTERN INTERIOR WILL BE IN THE
40 OVER THE NEXT COUPLE OF DAYS. THERE`S SOME RH`S NOW IN THE
UPPER 30S OVER THE WESTERN INTERIOR. A FEW TSTORMS WILL BE
POSSIBLE EACH OF THE NEXT FEW DAYS OVER THE INTERIOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 85 74 86 / 30 10 - 10
FORT LAUDERDALE 74 86 76 86 / 30 10 10 10
MIAMI 74 87 75 87 / 30 10 10 10
NAPLES 68 89 70 88 / - 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...71/JE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
131 PM EDT THU MAY 9 2013
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND INTO THE REGION THROUGH FRIDAY UNTIL A
COLD FRONT PASSES OVER THE FORECAST AREA LATE THIS WEEKEND. COOLER
HIGH PRESSURE WILL THEN SETTLE OVER THE REGION THROUGH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS AFTERNOON...NO CHANGES MADE TO THE FORECAST FOR THIS
UPDATE. PREVIOUS DISCUSSION FOLLOWS BELOW.
LATE THIS MORNING...A CLOSED UPPER LOW OVER THE
NORTHEAST WILL CONTINUE TO PULL AWAY FROM THE AREA TODAY AS
HEIGHTS RISE AND RIDGING BUILDS. SURFACE HIGH PRESSURE CENTERED
OVER THE EASTERN GULF OF MEXICO WILL DOMINATE THE PATTERN TODAY
WITH LIGHT SOUTHWEST FLOW. THE MAIN QUESTION FOR THE AFTERNOON
FORECAST IS THE POTENTIAL FOR ISOLATED SHOWER/THUNDERSTORM
DEVELOPMENT. LOW LEVEL THICKNESS VALUES SUPPORT HIGHS AROUND THE
MID 80S...AND WHEN MODIFYING THE 12Z CHS SOUNDING...THAT WOULD
GENERATE POSITIVE CAPE VALUES. HOWEVER...WITH THE RIDGE BUILDING
ALOFT AND HEIGHTS RISING...MID LEVEL TEMPS ARE PROGGED TO WARM
WHICH IS EXPECTED TO THWART ANY CONVECTIVE DEVELOPMENT. COARSER
RESOLUTION MODELS ARE GENERATING SOME CONVECTION RIGHT ALONG THE
COAST IN THE LATE AFTERNOON...WHILE HIGHER RESOLUTION RUNS FAVOR
THE DRY SIDE. LOOKING THROUGH AFTERNOON RAP SOUNDINGS SHOWS THE
POTENTIAL FOR VERY THIN CAPE...PRIMARILY ACROSS SOUTHEAST SC. WITH
THE WESTERLY FLOW IN PLACE...HAVE DECIDED TO STICK WITH A DRY
FORECAST AND FAVOR THE HIGHER RESOLUTION MODEL RUNS.
OTHERWISE...EXPECT A DECENT GOOD DIURNAL CU FIELD BEGINNING IN THE
EARLY AFTERNOON AND THEN DISSIPATING IN THE EARLY EVENING WITH THE
LOSS OF HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
TONIGHT...THE AREA WILL REMAIN ALONG THE WESTERN PERIPHERY OF
ATLANTIC HIGH PRESSURE TONIGHT. ANY LINGERING CUMULUS WILL QUICKLY
DISSIPATE WITH THE LOSS OF INSOLATION LEAVING MAINLY CLEAR SKIES.
THERE WILL BE SOME INCREASE IN HIGH-LEVEL MOISTURE EARLY
FRIDAY...BUT THE MOISTURE LOOKS PRETTY THIN AT THIS TIME. A MOSTLY
CLEAR SKY CHARACTER SHOULD WORK. MODEL 925MB WIND FIELDS DO NOT
INCREASE SUBSTANTIALLY OVERNIGHT SO EXPECT THE BOUNDARY LAYER TO
DECOUPLE RATHER QUICKLY THIS EVENING WITH FAIRLY LIGHT WIND FIELDS
PREVAILING...ESPECIALLY INLAND. LOWS WILL BOTTOM OUT IN THE LOWER
60S MOST LOCATIONS WITH MID 60S AT THE COAST. COULD SEE A FEW
UPPER 50S IN A FEW OF THE NORMALLY COOLER SITES SUCH AS ALLENDALE
AND JAMESTOWN.
FRIDAY...QUIET CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND WITH
WEAK HIGH PRESSURE AT THE SFC AND MID LVL RIDGING PEAKING ALOFT.
TEMPS WILL WARM CONSIDERABLY WITH SOUTHERLY FLOW IN PLACE UNDER
MOSTLY SUNNY SKIES. 1000-850 MB THICKNESSES FAVOR HIGH TEMPS IN THE
MID/UPPER 80S FRIDAY AFTERNOON...HIGHEST OVER INLAND AREAS IN
SOUTHEAST GEORGIA. FRIDAY NIGHT LOWS SHOULD REMAIN IN THE LOW/MID
60S AHEAD OF A COLD FRONT ADVANCING TO THE SOUTHEASTERN UNITED
STATES.
SATURDAY AND SUNDAY...CHANCES OF PRECIP WILL BEGIN TO INCREASE FOR
THE SECOND HALF OF THIS WEEKEND AS MID LVL RIDGING SLIDES EAST WHILE
SUBTLE H5 SHORTWAVES EJECT FROM THE SOUTHERN PLAINS TOWARDS THE
SOUTHEASTERN UNITED STATES. SHOWERS AND/OR THUNDERSTORM ACTIVITY
SHOULD INCREASE BY SATURDAY AFTERNOON/EVENING AS ISENTROPIC ASCENT
INCREASES AND BOUNDARY LAYER MOISTURE DEEPENS AHEAD OF A COLD FRONT
ADVANCING TOWARDS THE FORECAST AREA LATE. DESPITE INCREASING CLOUD
COVER...SFC TEMPS SHOULD PEAK IN THE LOW/MID 80S ON SATURDAY. PRECIP
COVERAGE SHOULD EXPAND SATURDAY NIGHT AS PWATS APPROACH 1.50-1.75
INCHES ALONG/AHEAD OF THE COLD FRONT.
AT THIS TIME...PRECIP ACTIVITY LOOKS TO PEAK AS THE COLD FRONT
PUSHES THROUGH THE FORECAST AREA SUNDAY MORNING. GIVEN THE TIME OF
COLD FROPA...THE CHANCE OF STRONGER THUNDERSTORMS WILL REMAIN LOW.
HOWEVER...SOME SHOWERS AND/OR THUNDERSTORMS MAY PRODUCE HEAVY RAIN
BEFORE THE COLD FRONT SHIFTS OFFSHORE. CONDITIONS WILL LIKELY
IMPROVE OVER THE AREA THROUGH SUNDAY EVENING AS HIGH PRESSURE BEGINS
TO BUILD IN BEHIND THE COLD FRONT SHIFTING OFFSHORE. GIVEN THE
AMOUNT OF CLOUD COVER AND SHOWER/THUNDERSTORM ACTIVITY...OVERALL
HIGH TEMPS WILL REMAIN COOLER ON SUNDAY...IN THE UPPER 70S TO AROUND
80.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A QUIET PERIOD OF WEATHER IS ANTICIPATED NEXT WEEK AS DRY AND COOLER
HIGH PRESSURE BUILDS IN BEHIND A COLD FRONT SHIFTING OVER THE
WESTERN ATLANTIC. MONDAY COULD START OFF BREEZY AS COOLER AIR SHIFTS
SOUTH OVER THE FORECAST AREA INITIALLY. OVERALL TEMPS WILL REMAIN IN
THE LOW/MID 70S MONDAY AND TUESDAY AS THE AREA REMAINS UNDER A
NORTHERLY FLOW. OVERNIGHT LOWS WILL ALSO BE COOL...IN THE UPPER 40S
TO LOWER 50S. TEMPS SHOULD THEN GRADUALLY WARM WEDNESDAY AND
THURSDAY AS SFC HIGH PRESSURE BECOMES CENTERED OVER THE SOUTHEASTERN
UNITED STATES WHILE A DOWNSLOPING WIND COMPONENT DEVELOPS OVER THE
FORECAST AREA. IN GENERAL...OVERALL TEMPS WILL WARM TO AROUND 80 ON
WEDNESDAY AND THEN INTO THE LOWER 80S ON THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
VFR THROUGH 18Z FRIDAY.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS WITH
COLD FRONTAL PASSAGE SATURDAY/SUNDAY.
&&
.MARINE...
TODAY AND TONIGHT...THERE ARE NO CONCERNS. A BROAD SOUTHERN FLOW
REGIME WILL PERSIST WITH SPEEDS GENERALLY 10-15 KT AND SEAS 2-4
FT.
FRIDAY THROUGH TUESDAY...MARINE CONDITIONS WILL REMAIN QUIET THROUGH
LATE WEEK AS HIGH PRESSURE REMAINS OVER THE WATERS. IN
GENERAL...WINDS WILL REMAIN AT OR BELOW 15 KTS...HIGHEST ALONG THE
COAST EACH AFTERNOON WITH SEABREEZE CIRCULATIONS. SEAS WILL REMAIN
AT OR BELOW 4 FT...HIGHEST OVER NORTHERN SC WATERS AND OUTER GEORGIA
WATERS. WINDS/SEAS WILL THEN GRADUALLY INCREASE/BUILD LATE WEEKEND
ALONG/AHEAD OF A COLD FRONT PASSING OVER THE WATERS ON SUNDAY.
ALTHOUGH CONDITIONS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS
WITH COLD FROPA...COOL HIGH PRESSURE BEHIND THE FRONT SHOULD RESULT
IN WINDS OF 15-20 KTS ALONG WITH SEAS BUILDING TO 4-5 FT ON
MONDAY...HIGHEST OVER WATERS BEYOND 10 NM FROM THE COAST. CONDITIONS
WILL THEN IMPROVE BY TUESDAY AND REMAIN WELL BELOW ADVISORY LEVELS
THROUGH THE MIDDLE OF NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BSH
SHORT TERM...DPB/ST
LONG TERM...DPB
AVIATION...BSH
MARINE...DPB/ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 PM CDT THU MAY 9 2013
.MESOSCALE DISCUSSION...141 PM CDT
CONTINUING TO MONITOR OBSERVATIONAL TRENDS TOWARD STORM POTENTIAL
WITH A SLIGHT RISK FOR A FEW SEVERE STORMS ACROSS MAINLY THE
SOUTHEAST QUARTER OF THE CWA OR SO PRIMARILY IN THE TIME WINDOW OF
4 PM TO 9 PM.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A WELL-DEFINED
SHORT WAVE...POSSIBLY CONVECTIVELY ENHANCED LOOKING BACK AT THE
PAST 12 HOURS...MOVING NORTHEAST FROM EAST CENTRAL MO. VAD
PROFILER DATA FROM LSX REVEALS 45 KT 700MB FLOW COINCIDENT WITH
THIS AND OTHER REGIONAL VAD DATA DEPICTS A LOW-LEVEL JET OF 35-40
KT NOSING UP IN ADVANCE OF THIS INTO CENTRAL/EAST CENTRAL IL.
AXES OF SHOWERS WITH STORMS CONTINUE TO REGENERATE IN THIS
FAVORED AREA...THOUGH MUCH OF THE LIGHTNING HAS HAD DIFFICULTY
THUS FAR REACHING NORTH OF I-74. LATEST HAND SURFACE ANALYSIS
PORTRAYS SOMEWHAT OF A MESSY PATTERN THANKS TO THE CONVECTIVE
ACTIVITY AND EVEN THE RAIN FROM EARLIER TODAY. THE SURFACE LOW
CONTINUES TO TAKE SHAPE ACROSS SOUTHEAST IA...THOUGH THE PRIMARY
WARM SECTOR IS SOMEWHAT WORKED OVER...WITH THE BEST UNTAPPED
HIGHER T/TD AIR ONLY AS FAR NORTH AS SOUTHERN IL. A CLEAR SWATH
WITH MAINLY ONLY SOME CIRRUS IS MOVING ACROSS THE AREA NORTH OF
THE SHOWER ACTIVITY AND DID ALLOW TEMPERATURES TO WARM INTO THE
70S ACROSS A LOT OF THE CWA.
SHOWERS WITH EMBEDDED STORMS SHOULD CONTINUE TO REGENERATE ACROSS
CENTRAL/EAST CENTRAL IL DURING THE MID TO LATE AFTERNOON WITH THE
AFOREMENTIONED SHORT WAVE AND LOW TO MID-LEVEL MOISTURE TRANSPORT
PROGRESSING NORTHEAST. WOULD EXPECT CONVECTION TO HAVE BETTER
CHANCES TO BECOME STRONGER IN FAR EASTERN IL TO WESTERN
IN...INCLUDING THE FAR SOUTHEAST CWA...AS THE MID-LEVEL FORCING
FOR ASCENT TRANSLATES OVER AN AIR MASS THAT IS MORE UNTAPPED.
MODIFIED RAP AND LAPS SOUNDINGS FROM NORTHWEST INDIANA DO CONTINUE
TO SHOW A CAP ALOFT IN MOST PLACES /THOUGH THE 78 DEGREES AT VPZ
BASICALLY HAS ERODED THAT/...WITH MLCAPE VALUES OF 500-800 J/KG
AND MUCAPE VALUES TOWARD 1200 J/KG. THIS INSTABILITY SHOULD NOT
INCREASE MUCH THROUGH THE COMING HOURS GIVEN THE CLOUDS AND LEAD
SHOWERS SPREADING IN. DEEP LAYER SHEAR IS FORECAST TO INCREASE TO
35-40 KT BY LATE AFTERNOON IN THIS AREA WHICH MAY SUPPORT SOME
TEMPORARY STRONGER ORGANIZED STORMS THAT COULD PRESENT AN ISOLATED
WIND THREAT. WHILE THERE LOOKS TO REMAIN A CHANCE FOR SCATTERED
CONVECTION LATER INTO THE EVE IN THESE AREAS AS THE SURFACE LOW
COMES ACROSS...THE MORE FOCUSED CONVECTION IS EXPECTED TO BE
ASSOCIATED EARLIER WITH THIS SHORT WAVE...AND CONVECTIVE ALLOWING
MODELS AGREE WITH THIS EVOLUTION.
FURTHER TO THE NORTH IN CHICAGO AND TOWARD ROCKFORD...WHILE THE
CLEARING HAS ALLOWED FOR SOME DESTABILIZATION...THE OVERALL
INSTABILITY REMAINS SOMEWHAT WEAK FOR WIDESPREAD STORM ACTIVITY.
THE POTENTIAL FOR RAIN WILL INCREASE QUICKLY AFTER 4 PM AND INTO
THE EVENING AS IMPROVED MOISTURE CONVERGENCE AHEAD OF THE WAVE
MOVES NORTH OVER THE AREA AND THEN PIVOTS WITH THE TRANSLATION OF
THE LOW ACROSS THE REGION. GOING QPF FORECASTS STILL LOOK ON
TRACK WITH 0.4 TO 0.75 INCHES OF RAIN IN MUCH OF NORTHERN AND
NORTHEAST IL.
MTF
&&
.DISCUSSION...
322 PM CDT
SHORT TERM...TONIGHT THROUGH SUNDAY
CONCERNS IN THIS PERIOD ARE WITH RAIN AND THUNDER CHANCES
TONIGHT...FOLLOWED BY TEMPERATURES SATURDAY NIGHT AND SUNDAY AS
THERE WILL BE A SIGNIFICANT COOL DOWN.
TONIGHT...WEAK SURFACE LOW WILL TRACK FROM FROM WESTERN ILLINOIS TO
NORTHERN INDIANA AND THEN TO SOUTHWEST LWR MI BY EARLY FRIDAY...WITH
OPEN UPPER WAVE ALSO PUSHING ACROSS REGION. AS THIS OCCURS...
WIDESPREAD SHRA WITH SOME EMBEDDED THUNDER INITIALLY WILL LIFT
NORTHEAST WITH CONVECTIVE ACTIVITY DIMINISHING AS ELEVATED
INSTABILITY DIMINISHES WITH TIME. PWAT OF 1.3 TO 1.4 INCHES AND GOOD
MOISTURE TRANSPORT AND CONVERGENCE WILL SUPPORT EFFICIENT RAINFALL
PRODUCTION AND THUS CANT RULE OUT MODERATE TO OCCASIONALLY HEAVY
RAIN RATES UNTIL THE LATE EVENING. AS LOW TRACKS ACROSS AREA...QUASI
STATIONARY FRONT THAT HAS BEEN LAID OUT ACROSS AREA THIS AFTERNOON
WILL PUSH SOUTH AS A COLD FRONT THROUGH ALL BUT SOUTHEASTERN
CWA...WITH COOLER AIR MASS/IN THE 40S TO LOWER 50S FILTERING IN BY
EARLY FRIDAY.
MOST SHRA ACTIVITY SHOULD BE ISOLATED AT BEST ON FRIDAY...EXCEPT FOR
PERHAPS MORE SCATTERED SHRA AHEAD OF FRONT AS IT FINALLY CLEARS OUR
FAR SOUTHEAST BY EARLY AFTERNOON. MILDER START IN THIS AREA COULD
ALLOW HIGHS TO REACH MID TO UPPER 60S...WITH REST OF AREA AWAY FROM
LAKE GENERALLY IN THE LOWER 60S. BIG STORY FRIDAY WILL BE THE STRONG
PUSH OF NORTHERLY WINDS DOWN THE LENGTH OF LAKE MICHIGAN BRINGING
QUITE A CHILLY DAY...WITH HIGHS ONLY AROUND 50 AND WINDS GUSTING AS
HIGH AS 30 MPH.
FRIDAY NIGHT WILL BE DRY AND COOL WITH LOWS IN THE 40S...BUT
AN UNSEASONABLY DEEP UPPER TROUGH WILL PUSH INTO THE UPPER GREAT
LAKES REGION BY SATURDAY...WITH A STRONG COLD FRONT TRAILING FROM
SURFACE LOW PRESSURE. THIS FRONT SHOULD TOUCH OFF A FEW SCT SHRA AS
IT PUSHES THROUGH THE CWA ON SATURDAY DUE TO STEEPENING LOW LEVEL
LAPSE RATES...BUT THE MAIN FOCUS WILL BE THE 850 MB TEMPS COOLING TO
-3C TO -4C BY EARLY SUNDAY...LEAVING A COOL BUT MOSTLY SUNNY MOTHERS
DAY. SOME CONCERN WITH FROST POTENTIAL AS EARLY AS SATURDAY
NIGHT...BUT HIGH PRESSURE SHOULD BE FAR ENOUGH WEST TO MAINTAIN A
GRADIENT AND PRECLUDE FROST FORMATION. ACTUALLY A BIGGER CONCERN
SATURDAY NIGHT IS THAT WHETHER THERE IS FROST OR NOT...AIR TEMPS IN
OUTLYING AREAS COULD DIP TO OR BELOW FREEZING IN UNSEASONABLY COOL
AND DRY AIR MASS IN PLACE. IF THE SUB FREEZING TEMPS REALIZED ON
SOME GUIDANCE IS REALIZED...MAY NEED A FREEZE WATCH FOR PORTIONS OF
AREA SATURDAY NIGHT...AS WE ARE QUICKLY TRENDING TO FULL VEGETATION.
DESPITE FULL SUNSHINE ON MOTHERS DAY...CLIMO WITH 850 TEMPS SUBZERO
C ONLY SUPPORTS HIGHS IN THE MID TO UPPER 50S.
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...
CONCERNS IN THE LONG TERM WILL RAPIDLY SHIFT FROM COLD WEATHER
CONCERNS INITIALLY TO VERY WARM TEMPERATURES ON TUESDAY. HIGH
PRESSURE RIDGE AXIS WILL BE OVER THE REGION SUNDAY NIGHT YIELDING
MUCH LIGHTER WINDS. COUPLED WITH CLEAR SKIES AND DRY AIR MASS...WITH
DEWPOINTS ONLY AROUND 30...STAGE COULD BE SET FOR LOWS NEAR FREEZING
IN SOME AREAS EARLY MONDAY AND ALSO FROST POTENTIAL. AGAIN LOWERED
TEMPS FROM BLEND OF PREVIOUS FCST AND CONSENSUS GUIDANCE TO
GENERALLY MID 30S EXCEPT RIGHT IN THE CHICAGO HEAT ISLAND...WITH
NEAR FREEZING TEMPS IN TYPICALLY COLDER RURAL AND SUBURBAN LOCATIONS
WEST OF THE FOX RIVER. WILL ADD PATCHY FROST TO THE GRIDS FOR AREAS
AWAY FROM CHICAGO.
THEN EARLY NEXT WEEK...UPPER LEVEL RIDGE QUICKLY AMPLIFIES OVER THE
AREA...WITH RAPIDLY WARMING TEMPS ALOFT. ON MONDAY...HIGHS WILL WARM
NICELY TO THE MID 60S AFTER THE CHILLY START. THEN TUES...850 TEMPS
SOAR TO 18+ TO +20C OR HIGHER (NEW ECMWF HAS +23C! OVER NORTH
CENTRAL IL BY 00Z WEDS) IN GUSTY SOUTHWESTERLY BDRY LAYER FLOW. 850
MB CLIMO WOULD SUGGEST MID 80S AT A MINIUM IN MID MAY WITH
THESE TEMPS ALOFT. FCST SOUNDINGS SUGGEST HOW DEEP WE MIX COULD
BE A LIMITING FACTOR/IE. TO AROUND 900 MB ON THE GFS AND ECMWF.
AGAIN BUMPED TEMPERATURES UP FROM PREVIOUS FCST AND CONSENSUS BLEND
TO LOW TO MID 80S AND EVEN THIS COULD BE CONSERVATIVE WITH SUCH A
WARM AIR MASS IN PLACE ASSUMING THERE ARE NO LINGERING ISSUES WITH
WAA CLOUD COVER. EXTENDED GUIDANCE CONSISTENT IN FEATURING COLD
FRONT SLIPPING SOUTH INTO PORTION OF AREA ON WEDNESDAY...THOUGH
IT APPEARS IT WILL BE ANOTHER WARM DAY WITH HIGHS AT LEAST INTO
THE UPPER 70S TO AROUND 80. THERE ARE SOME DIFFERENCES ON
SHRA/TSRA CHANCES WITH THIS FRONT...AS NORTHERN CWA COULD BE
FAVORED WEDS AFTERNOON WITH BETTER CHANCES BY WEDNESDAY NIGHT.
GUIDANCE THEN DIVERGES ON HOW FAST FRONT PUSHES THROUGH AREA...AS
IT COULD STALL OUT THURSDAY AND EVEN INTO FRIDAY...KEEPING SHRA
AND TSRA CHANCES GOING.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHOWERS WITH ISOLATED/SCATTERED TSRA THIS AFTERNOON.
* SHOWERS THIS EVENING...ENDING OVERNIGHT.
* SOUTHERLY WINDS BECOMING EASTERLY BY EARLY EVENING THEN NORTH
BY LATE EVENING...WITH SOME GUSTS POSSIBLE OVERNIGHT.
* MVFR CIGS BY EARLY EVENING WITH IFR/LIFR CIGS DEVELOPING DURING
THE EVENING...IMPROVING TO MVFR FRIDAY MORNING. CMS
//DISCUSSION...UPDATED 18Z...
LINE OF SHRA/TSRA LIFTING NORTH ACROSS CENTRAL IL HAS BEGUN TO
WEAKEN AS ADDITIONAL TSRA LIFT NORTHEAST ACROSS EASTERN IL. WHILE
THIS ACTIVITY IS WEAKENING...HAVE ADJUSTED TIMING...A LITTLE
EARLIER...AS SOME SHOWER ACTIVITY WILL LIKELY REACH THE TERMINALS
BY MID AFTERNOON. ADDITIONAL SHOWERS AND PERHAPS ISOLATED TSRA
WILL CONTINUE TO DEVELOP/SPREAD NORTH ACROSS THE AREA THROUGH
EARLY THIS EVENING AS AN UPPER WAVE LIFTS NORTH. APPEARS THE BEST
THUNDER COVERAGE WILL REMAIN SOUTHEAST OF THE TERMINALS AND FOR
NOW HAVE MAINTAINED VCTS BUT TRENDS WILL NEED TO BE MONITORED FOR
UPDATES. AS AN AREA OF SURFACE LOW PRESSURE MOVES ACROSS THE AREA
LATE TONIGHT INTO THE EARLY OVERNIGHT HOURS...ADDITIONAL SHOWERS
WILL BE POSSIBLE.
THIS SURFACE LOW...AND THE LOCATION OF THE WARM FRONT AHEAD OF IT
THIS AFTERNOON WILL MAKE WIND DIRECTIONS PROBLEMATIC. SOUTHERLY
WINDS TO THE I-80 CORRIDOR LOOK ON TRACK BUT AT MDW/ORD...WINDS ON
ONE MINUTE DATA HAVE BEEN LIGHT WESTERLY TO LIGHT EASTERLY...AS
WELL AS CALM. WHILE GRADIENT REMAINS WEAK...APPEARS AS THE SURFACE
LOW APPROACHES...SOUTHEASTERLY WINDS WILL LIKELY PREVAIL AND THEN
SHIFT MORE EAST THEN NORTHEAST THIS EVENING BUT CONFIDENCE
REGARDING WINDS THROUGH THIS EVENING REMAINS LOW.
CIGS WILL LIKELY BEGIN TO FALL INTO MVFR AS PRECIP DEVELOPS AND AS
THE LOW LEVELS SATURATE WITH FLOW OFF THE LAKE...EXPECT CIGS TO
QUICKLY LOWER INTO IFR THIS EVENING AND AS THE SURFACE LOW
APPROACHES...CIGS LIKELY TO DROP INTO LIFR AND POSSIBLY VLIFR WITH
CIGS SLOWLY LIFTING FRIDAY MORNING AS THE LOW SHIFTS EAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE REGARDING SHOWERS TIMING/TRENDS.
* LOW CONFIDENCE REGARDING TSRA THIS AFTERNOON INTO THIS EVENING.
* MEDIUM CONFIDENCE REGARDING CIGS THROUGH THE PERIOD.
* LOW CONFIDENCE REGARDING WINDS THIS AFTERNOON...MEDIUM
CONFIDENCE FOR THE REST OF THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...CLEARING SKIES.
SATURDAY...VFR. GUSTY NORTHWEST WINDS.
SUNDAY AND MONDAY...VFR.
TUESDAY...STRONG SOUTHERLY WINDS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
236 PM CDT
A SLOW MOVING COLD FRONT CONTINUES TO SAG SOUTH ACROSS LAKE
MICHIGAN THIS AFTERNOON. AN AREA OF LOW PRESSURE CENTERED NEAR
SOUTHEAST IOWA THIS AFTERNOON WILL LIFT NORTHEAST ALONG THIS
FRONTAL BOUNDARY...INTO NORTHERN ILLINOIS. THEN THE LOW PRESSURE
WILL CONTINUE TO SLIDE EAST ACROSS NORTHERN ILLINOIS FRIDAY
MORNING. MEANWHILE...THE GRADIENT BEHIND THE FRONTAL BOUNDARY WILL
TIGHTEN OVER THE NORTHERN PORTION OF THE LAKE...ALLOWING
NORTH/NORTHEAST WINDS TO INCREASE TO 15 TO 25 KT WITH OCCASIONAL
GUSTS TO 30 KT. THE NORTH WINDS WILL EVENTUALLY REACH THE SOUTHERN
PORTION OF LAKE MICHIGAN...ALLOWING FOR A LONG FETCH TO SETUP.
THIS POINTS TOWARDS BUILDING WAVES FOR THE SOUTHERN TIP OF THE
LAKE...INCLUDING BOTH THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS. HAVE HOISTED A SMALL CRAFT ADVISORY TO ACCOUNT FOR THE
HAZARDOUS WINDS/WAVES OVERNIGHT...ACROSS ILLINOIS NEARSHORE ZONES
FIRST...THEN REACHING NORTHWEST INDIANA NEARSHORE WATERS FRIDAY
MORNING.
WAVES WILL REMAIN HAZARDOUS THROUGH MUCH OF THE DAY
FRIDAY...DESPITE SLOWLY DIMINISHING WINDS AS A WEAK AREA OF HIGH
PRESSURE BUILDS OVER THE LAKE FRIDAY EVENING THROUGH EARLY
SATURDAY. THEN ANOTHER STRONG COLD FRONT WILL SLIDE EAST ACROSS
THE UPPER MIDWEST EARLY SATURDAY...REACHING LAKE MICHIGAN BY
MIDDAY. THIS WILL BRING ANOTHER TIGHT GRADIENT AND A RETURN TO
GUSTY NORTHWEST WINDS. AT THIS TIME GUSTS SHOULD BE AROUND 30
KT...HOWEVER A FEW GALE FORCE GUSTS MAY OCCUR.
LIGHT AND VARIABLE WINDS SET UP AGAIN FOR LATE SUNDAY INTO
MONDAY...AS ANOTHER AREA OF HIGH PRESSURE BUILDS ACROSS THE
WESTERN LAKES. THIS HIGH SHIFTS EAST MONDAY NIGHT...WITH YET
ANOTHER SHARP PRESSURE GRADIENT DEVLEOPING ACROSS THE WESTERN
LAKES TUESDAY WITH A POTENT STORM SYSTEM SLIDING EAST ACROSS
ONTARIO TUESDAY. THIS WILL ALLOW STRONG SOUTHERLY WINDS AHEAD OF
THE FRONTAL BOUNDARY.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM FRIDAY TO 4
AM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...7 AM FRIDAY TO 4
AM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 PM CDT THU MAY 9 2013
.MESOSCALE DISCUSSION...
141 PM CDT
CONTINUING TO MONITOR OBSERVATIONAL TRENDS TOWARD STORM POTENTIAL
WITH A SLIGHT RISK FOR A FEW SEVERE STORMS ACROSS MAINLY THE
SOUTHEAST QUARTER OF THE CWA OR SO PRIMARILY IN THE TIME WINDOW OF
4 PM TO 9 PM.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A WELL-DEFINED
SHORT WAVE...POSSIBLY CONVECTIVELY ENHANCED LOOKING BACK AT THE
PAST 12 HOURS...MOVING NORTHEAST FROM EAST CENTRAL MO. VAD
PROFILER DATA FROM LSX REVEALS 45 KT 700MB FLOW COINCIDENT WITH
THIS AND OTHER REGIONAL VAD DATA DEPICTS A LOW-LEVEL JET OF 35-40
KT NOSING UP IN ADVANCE OF THIS INTO CENTRAL/EAST CENTRAL IL.
AXES OF SHOWERS WITH STORMS CONTINUE TO REGENERATE IN THIS
FAVORED AREA...THOUGH MUCH OF THE LIGHTNING HAS HAD DIFFICULTY
THUS FAR REACHING NORTH OF I-74. LATEST HAND SURFACE ANALYSIS
PORTRAYS SOMEWHAT OF A MESSY PATTERN THANKS TO THE CONVECTIVE
ACTIVITY AND EVEN THE RAIN FROM EARLIER TODAY. THE SURFACE LOW
CONTINUES TO TAKE SHAPE ACROSS SOUTHEAST IA...THOUGH THE PRIMARY
WARM SECTOR IS SOMEWHAT WORKED OVER...WITH THE BEST UNTAPPED
HIGHER T/TD AIR ONLY AS FAR NORTH AS SOUTHERN IL. A CLEAR SWATH
WITH MAINLY ONLY SOME CIRRUS IS MOVING ACROSS THE AREA NORTH OF
THE SHOWER ACTIVITY AND DID ALLOW TEMPERATURES TO WARM INTO THE
70S ACROSS A LOT OF THE CWA.
SHOWERS WITH EMBEDDED STORMS SHOULD CONTINUE TO REGENERATE ACROSS
CENTRAL/EAST CENTRAL IL DURING THE MID TO LATE AFTERNOON WITH THE
AFOREMENTIONED SHORT WAVE AND LOW TO MID-LEVEL MOISTURE TRANSPORT
PROGRESSING NORTHEAST. WOULD EXPECT CONVECTION TO HAVE BETTER
CHANCES TO BECOME STRONGER IN FAR EASTERN IL TO WESTERN
IN...INCLUDING THE FAR SOUTHEAST CWA...AS THE MID-LEVEL FORCING
FOR ASCENT TRANSLATES OVER AN AIR MASS THAT IS MORE UNTAPPED.
MODIFIED RAP AND LAPS SOUNDINGS FROM NORTHWEST INDIANA DO CONTINUE
TO SHOW A CAP ALOFT IN MOST PLACES /THOUGH THE 78 DEGREES AT VPZ
BASICALLY HAS ERODED THAT/...WITH MLCAPE VALUES OF 500-800 J/KG
AND MUCAPE VALUES TOWARD 1200 J/KG. THIS INSTABILITY SHOULD NOT
INCREASE MUCH THROUGH THE COMING HOURS GIVEN THE CLOUDS AND LEAD
SHOWERS SPREADING IN. DEEP LAYER SHEAR IS FORECAST TO INCREASE TO
35-40 KT BY LATE AFTERNOON IN THIS AREA WHICH MAY SUPPORT SOME
TEMPORARY STRONGER ORGANIZED STORMS THAT COULD PRESENT AN ISOLATED
WIND THREAT. WHILE THERE LOOKS TO REMAIN A CHANCE FOR SCATTERED
CONVECTION LATER INTO THE EVE IN THESE AREAS AS THE SURFACE LOW
COMES ACROSS...THE MORE FOCUSED CONVECTION IS EXPECTED TO BE
ASSOCIATED EARLIER WITH THIS SHORT WAVE...AND CONVECTIVE ALLOWING
MODELS AGREE WITH THIS EVOLUTION.
FURTHER TO THE NORTH IN CHICAGO AND TOWARD ROCKFORD...WHILE THE
CLEARING HAS ALLOWED FOR SOME DESTABILIZATION...THE OVERALL
INSTABILITY REMAINS SOMEWHAT WEAK FOR WIDESPREAD STORM ACTIVITY.
THE POTENTIAL FOR RAIN WILL INCREASE QUICKLY AFTER 4 PM AND INTO
THE EVENING AS IMPROVED MOISTURE CONVERGENCE AHEAD OF THE WAVE
MOVES NORTH OVER THE AREA AND THEN PIVOTS WITH THE TRANSLATION OF
THE LOW ACROSS THE REGION. GOING QPF FORECASTS STILL LOOK ON
TRACK WITH 0.4 TO 0.75 INCHES OF RAIN IN MUCH OF NORTHERN AND
NORTHEAST IL.
MTF
&&
.DISCUSSION...
354 AM CDT
IN THE NEAR TERM...CLOSED MID-LEVEL CIRCULATION WAS LOCATED NEAR
SIOUX FALLS EARLY THIS AM...WITH ADDITIONAL SHORT WAVE ENERGY AND
ASSOCIATED CONVECTIVE CLUSTERS OVER OKLAHOMA/KANSAS. UPPER LOW IS
EXPECTED TO OPEN UP AND PHASE WITH SOUTHERN ENERGY INTO A POSITIVE
TILT TROUGH WHICH WILL MOVE SLOWLY EAST ACROSS THE REGION THROUGH
FRIDAY. WEAK SURFACE LOW PRESSURE OVER NORTHEAST KANSAS WILL DEEPEN
SLIGHTLY IN THE PROCESS...AND MOVE TO SOUTHEAST IA/WESTERN IL BY
THIS EVENING. SOUTHERLY 25-35 KT LOW LEVEL JET AND ASSOCIATED
MOISTURE TRANSPORT CURRENTLY FOCUSED INTO OK/KS/WESTERN MO WILL
GRADUALLY VEER INTO IL DURING THE DAY...AFFECTING OUR CWA
PARTICULARLY FROM LATE MORNING THROUGH THIS AFTERNOON/EARLY
EVENING. WITH SURFACE LOW PROGGED ACROSS CENTRAL/NORTHERN IL THIS
AFTERNOON AND EVENING...EFFECTIVE WARM FRONT DEVELOPS WEST-EAST
ACROSS THE SOUTHERN HALF OF THE CWA. FORECAST SOUNDINGS INDICATE
BETWEEN 500-1200 J/KG MLCAPE IN THE WARM SECTOR ALONG/SOUTH OF THE
FRONT...WHILE MID LEVEL LAPSE RATES FARTHER NORTH REMAIN MARGINAL
BUT LIKELY SUFFICIENT FOR OCCASIONAL THUNDER THERE. WHILE CLOUD
COVER AND PRECIP COVERAGE MAY LIMIT SFC/NEAR SFC BASED
DESTABILIZATION SOMEWHAT...PRESENCE OF 30-40 KT MID LEVEL FLOW AND
25-35 KT 0-6 KM BULK SHEAR DOES SUPPORT ORGANIZED CONVECTION. LINE
SEGMENTS WITH ATTENDANT SEVERE WIND/HAIL THREAT ARE EXPECTED TO BE
THE MAIN SEVERE WEATHER THREAT...THOUGH BACKED LOW LEVEL FLOW
NEAR/ALONG THE WARM FRONT COULD SUPPORT MINIMAL TORNADO POTENTIAL
PARTICULARLY IF LESS CLOUD COVER/MORE INSTABILITY WERE TO OCCUR.
MORE WIDESPREAD ISSUE IS LIKELY TO BE POTENTIAL FOR RAINFALL AMOUNTS
IN EXCESS OF 1.0 INCHES WITH RAIN/STORMS AS PWATS INCREASE TO AROUND
1.35 INCHES BY LATE AFTERNOON/EVENING. HEAVIER RAIN AND
THUNDERSTORMS SHOULD GRADUALLY MOVE OFF TO THE EAST/SOUTHEAST OF THE
CWA LATER TONIGHT...AS SFC LOW AND COLD FRONT MOVE THROUGH AND AXIS
OF BEST LOW LEVEL MOISTURE TRANSPORT VEERS ACROSS IN/OH.
SHOWERY WEATHER WILL LIKELY CONTINUE INTO FRIDAY HOWEVER...AS SLOW
MOVING UPPER TROUGH TRAVERSES THE FORECAST AREA. COOLER AIR WILL
FILTER IN AS WELL...WITH TEMPS FALLING FROM TODAYS UPPER 60S-MID 70S
TO LOWER-MID 60S NORTH TO SOUTH...AND 50S ALONG LAKE MICHIGAN.
GUIDANCE REMAINS STEADFAST IN DIGGING STRONG SHORT WAVE INTO THE
REGION AND AMPLIFYING UPPER TROUGH ACROSS THE FRIDAY NIGHT AND
SATURDAY. AS ADVERTISED EARLIER...SHARP SURFACE COLD FRONT IS
EXPECTED TO PUSH THROUGH DURING THE MORNING/MIDDAY HOURS...WITH
TEMPS LIKELY FALLING INTO THE 50S BEHIND THE FRONT DURING THE
AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE BUILDS ACROSS THE PLAINS
AND MISSISSIPPI VALLEY SATURDAY NIGHT...SETTING THE STAGE FOR A
CHILLY MOTHERS DAY. 850 MB TEMPS IN THE NEGATIVE SINGLE DIGITS
PORTEND AFTERNOON HIGHS STRUGGLING TO GET TO/ABOVE 60 ESPECIALLY
ACROSS NORTHEAST IL/NORTHWEST IN. LOWS WILL LIKELY DIP INTO THE 30S
IN SOME NORTHERN PARTS OF THE CWA SATURDAY NIGHT AND AGAIN SUNDAY
NIGHT. LOOKS LIKE ENOUGH GRADIENT/WIND TO PREVENT PATCHY FROST
DEVELOPMENT BEHIND THE FRONT SATURDAY NIGHT...THOUGH THERE COULD BE
SOME FROST IN COLDER MORE SHELTERED AREAS LATE SUNDAY NIGHT.
AS QUICKLY AS WE COOL DOWN OVER THE NEXT COUPLE OF DAYS...GUIDANCE
CONTINUES TO INDICATE THAT THE DEEP UPPER TROUGH WILL BE
PROGRESSIVE. UPPER RIDGING AND STRONG WARM ADVECTION LOOKS TO PUSH
OUR TEMPS BACK FIRMLY INTO THE 60S MONDAY...AND QUITE POSSIBLY THE
80S ESPECIALLY WEST BY TUESDAY AS 850 MB TEMPS APPROACH +20 C. WEAK
SLOW MOVING COOL FRONT SAGS ACROSS THE AREA WEDNESDAY TEMPERING THE
WARM-UP A BIT POTENTIALLY ACROSS THE NORTH...ALONG WITH THE NEXT
CHANCE OF SHOWERS/STORMS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHOWERS WITH ISOLATED/SCATTERED TSRA THIS AFTERNOON.
* SHOWERS THIS EVENING...ENDING OVERNIGHT.
* SOUTHERLY WINDS BECOMING EASTERLY BY EARLY EVENING THEN NORTH
BY LATE EVENING...WITH SOME GUSTS POSSIBLE OVERNIGHT.
* MVFR CIGS BY EARLY EVENING WITH IFR/LIFR CIGS DEVELOPING DURING
THE EVENING...IMPROVING TO MVFR FRIDAY MORNING. CMS
//DISCUSSION...UPDATED 18Z...
LINE OF SHRA/TSRA LIFTING NORTH ACROSS CENTRAL IL HAS BEGUN TO
WEAKEN AS ADDITIONAL TSRA LIFT NORTHEAST ACROSS EASTERN IL. WHILE
THIS ACTIVITY IS WEAKENING...HAVE ADJUSTED TIMING...A LITTLE
EARLIER...AS SOME SHOWER ACTIVITY WILL LIKELY REACH THE TERMINALS
BY MID AFTERNOON. ADDITIONAL SHOWERS AND PERHAPS ISOLATED TSRA
WILL CONTINUE TO DEVELOP/SPREAD NORTH ACROSS THE AREA THROUGH
EARLY THIS EVENING AS AN UPPER WAVE LIFTS NORTH. APPEARS THE BEST
THUNDER COVERAGE WILL REMAIN SOUTHEAST OF THE TERMINALS AND FOR
NOW HAVE MAINTAINED VCTS BUT TRENDS WILL NEED TO BE MONITORED FOR
UPDATES. AS AN AREA OF SURFACE LOW PRESSURE MOVES ACROSS THE AREA
LATE TONIGHT INTO THE EARLY OVERNIGHT HOURS...ADDITIONAL SHOWERS
WILL BE POSSIBLE.
THIS SURFACE LOW...AND THE LOCATION OF THE WARM FRONT AHEAD OF IT
THIS AFTERNOON WILL MAKE WIND DIRECTIONS PROBLEMATIC. SOUTHERLY
WINDS TO THE I-80 CORRIDOR LOOK ON TRACK BUT AT MDW/ORD...WINDS ON
ONE MINUTE DATA HAVE BEEN LIGHT WESTERLY TO LIGHT EASTERLY...AS
WELL AS CALM. WHILE GRADIENT REMAINS WEAK...APPEARS AS THE SURFACE
LOW APPROACHES...SOUTHEASTERLY WINDS WILL LIKELY PREVAIL AND THEN
SHIFT MORE EAST THEN NORTHEAST THIS EVENING BUT CONFIDENCE
REGARDING WINDS THROUGH THIS EVENING REMAINS LOW.
CIGS WILL LIKELY BEGIN TO FALL INTO MVFR AS PRECIP DEVELOPS AND AS
THE LOW LEVELS SATURATE WITH FLOW OFF THE LAKE...EXPECT CIGS TO
QUICKLY LOWER INTO IFR THIS EVENING AND AS THE SURFACE LOW
APPROACHES...CIGS LIKELY TO DROP INTO LIFR AND POSSIBLY VLIFR WITH
CIGS SLOWLY LIFTING FRIDAY MORNING AS THE LOW SHIFTS EAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE REGARDING SHOWERS TIMING/TRENDS.
* LOW CONFIDENCE REGARDING TSRA THIS AFTERNOON INTO THIS EVENING.
* MEDIUM CONFIDENCE REGARDING CIGS THROUGH THE PERIOD.
* LOW CONFIDENCE REGARDING WINDS THIS AFTERNOON...MEDIUM
CONFIDENCE FOR THE REST OF THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...CLEARING SKIES.
SATURDAY...VFR. GUSTY NORTHWEST WINDS.
SUNDAY AND MONDAY...VFR.
TUESDAY...STRONG SOUTHERLY WINDS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
236 PM CDT
A SLOW MOVING COLD FRONT CONTINUES TO SAG SOUTH ACROSS LAKE
MICHIGAN THIS AFTERNOON. AN AREA OF LOW PRESSURE CENTERED NEAR
SOUTHEAST IOWA THIS AFTERNOON WILL LIFT NORTHEAST ALONG THIS
FRONTAL BOUNDARY...INTO NORTHERN ILLINOIS. THEN THE LOW PRESSURE
WILL CONTINUE TO SLIDE EAST ACROSS NORTHERN ILLINOIS FRIDAY
MORNING. MEANWHILE...THE GRADIENT BEHIND THE FRONTAL BOUNDARY WILL
TIGHTEN OVER THE NORTHERN PORTION OF THE LAKE...ALLOWING
NORTH/NORTHEAST WINDS TO INCREASE TO 15 TO 25 KT WITH OCCASIONAL
GUSTS TO 30 KT. THE NORTH WINDS WILL EVENTUALLY REACH THE SOUTHERN
PORTION OF LAKE MICHIGAN...ALLOWING FOR A LONG FETCH TO SETUP.
THIS POINTS TOWARDS BUILDING WAVES FOR THE SOUTHERN TIP OF THE
LAKE...INCLUDING BOTH THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS. HAVE HOISTED A SMALL CRAFT ADVISORY TO ACCOUNT FOR THE
HAZARDOUS WINDS/WAVES OVERNIGHT...ACROSS ILLINOIS NEARSHORE ZONES
FIRST...THEN REACHING NORTHWEST INDIANA NEARSHORE WATERS FRIDAY
MORNING.
WAVES WILL REMAIN HAZARDOUS THROUGH MUCH OF THE DAY
FRIDAY...DESPITE SLOWLY DIMINISHING WINDS AS A WEAK AREA OF HIGH
PRESSURE BUILDS OVER THE LAKE FRIDAY EVENING THROUGH EARLY
SATURDAY. THEN ANOTHER STRONG COLD FRONT WILL SLIDE EAST ACROSS
THE UPPER MIDWEST EARLY SATURDAY...REACHING LAKE MICHIGAN BY
MIDDAY. THIS WILL BRING ANOTHER TIGHT GRADIENT AND A RETURN TO
GUSTY NORTHWEST WINDS. AT THIS TIME GUSTS SHOULD BE AROUND 30
KT...HOWEVER A FEW GALE FORCE GUSTS MAY OCCUR.
LIGHT AND VARIABLE WINDS SET UP AGAIN FOR LATE SUNDAY INTO
MONDAY...AS ANOTHER AREA OF HIGH PRESSURE BUILDS ACROSS THE
WESTERN LAKES. THIS HIGH SHIFTS EAST MONDAY NIGHT...WITH YET
ANOTHER SHARP PRESSURE GRADIENT DEVLEOPING ACROSS THE WESTERN
LAKES TUESDAY WITH A POTENT STORM SYSTEM SLIDING EAST ACROSS
ONTARIO TUESDAY. THIS WILL ALLOW STRONG SOUTHERLY WINDS AHEAD OF
THE FRONTAL BOUNDARY.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM FRIDAY TO 4
AM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...7 AM FRIDAY TO 4
AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT THU MAY 9 2013
.MESOSCALE DISCUSSION...
141 PM CDT
CONTINUING TO MONITOR OBSERVATIONAL TRENDS TOWARD STORM POTENTIAL
WITH A SLIGHT RISK FOR A FEW SEVERE STORMS ACROSS MAINLY THE
SOUTHEAST QUARTER OF THE CWA OR SO PRIMARILY IN THE TIME WINDOW OF
4 PM TO 9 PM.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A WELL-DEFINED
SHORT WAVE...POSSIBLY CONVECTIVELY ENHANCED LOOKING BACK AT THE
PAST 12 HOURS...MOVING NORTHEAST FROM EAST CENTRAL MO. VAD
PROFILER DATA FROM LSX REVEALS 45 KT 700MB FLOW COINCIDENT WITH
THIS AND OTHER REGIONAL VAD DATA DEPICTS A LOW-LEVEL JET OF 35-40
KT NOSING UP IN ADVANCE OF THIS INTO CENTRAL/EAST CENTRAL IL.
AXES OF SHOWERS WITH STORMS CONTINUE TO REGENERATE IN THIS
FAVORED AREA...THOUGH MUCH OF THE LIGHTNING HAS HAD DIFFICULTY
THUS FAR REACHING NORTH OF I-74. LATEST HAND SURFACE ANALYSIS
PORTRAYS SOMEWHAT OF A MESSY PATTERN THANKS TO THE CONVECTIVE
ACTIVITY AND EVEN THE RAIN FROM EARLIER TODAY. THE SURFACE LOW
CONTINUES TO TAKE SHAPE ACROSS SOUTHEAST IA...THOUGH THE PRIMARY
WARM SECTOR IS SOMEWHAT WORKED OVER...WITH THE BEST UNTAPPED
HIGHER T/TD AIR ONLY AS FAR NORTH AS SOUTHERN IL. A CLEAR SWATH
WITH MAINLY ONLY SOME CIRRUS IS MOVING ACROSS THE AREA NORTH OF
THE SHOWER ACTIVITY AND DID ALLOW TEMPERATURES TO WARM INTO THE
70S ACROSS A LOT OF THE CWA.
SHOWERS WITH EMBEDDED STORMS SHOULD CONTINUE TO REGENERATE ACROSS
CENTRAL/EAST CENTRAL IL DURING THE MID TO LATE AFTERNOON WITH THE
AFOREMENTIONED SHORT WAVE AND LOW TO MID-LEVEL MOISTURE TRANSPORT
PROGRESSING NORTHEAST. WOULD EXPECT CONVECTION TO HAVE BETTER
CHANCES TO BECOME STRONGER IN FAR EASTERN IL TO WESTERN
IN...INCLUDING THE FAR SOUTHEAST CWA...AS THE MID-LEVEL FORCING
FOR ASCENT TRANSLATES OVER AN AIR MASS THAT IS MORE UNTAPPED.
MODIFIED RAP AND LAPS SOUNDINGS FROM NORTHWEST INDIANA DO CONTINUE
TO SHOW A CAP ALOFT IN MOST PLACES /THOUGH THE 78 DEGREES AT VPZ
BASICALLY HAS ERODED THAT/...WITH MLCAPE VALUES OF 500-800 J/KG
AND MUCAPE VALUES TOWARD 1200 J/KG. THIS INSTABILITY SHOULD NOT
INCREASE MUCH THROUGH THE COMING HOURS GIVEN THE CLOUDS AND LEAD
SHOWERS SPREADING IN. DEEP LAYER SHEAR IS FORECAST TO INCREASE TO
35-40 KT BY LATE AFTERNOON IN THIS AREA WHICH MAY SUPPORT SOME
TEMPORARY STRONGER ORGANIZED STORMS THAT COULD PRESENT AN ISOLATED
WIND THREAT. WHILE THERE LOOKS TO REMAIN A CHANCE FOR SCATTERED
CONVECTION LATER INTO THE EVE IN THESE AREAS AS THE SURFACE LOW
COMES ACROSS...THE MORE FOCUSED CONVECTION IS EXPECTED TO BE
ASSOCIATED EARLIER WITH THIS SHORT WAVE...AND CONVECTIVE ALLOWING
MODELS AGREE WITH THIS EVOLUTION.
FURTHER TO THE NORTH IN CHICAGO AND TOWARD ROCKFORD...WHILE THE
CLEARING HAS ALLOWED FOR SOME DESTABILIZATION...THE OVERALL
INSTABILITY REMAINS SOMEWHAT WEAK FOR WIDESPREAD STORM ACTIVITY.
THE POTENTIAL FOR RAIN WILL INCREASE QUICKLY AFTER 4 PM AND INTO
THE EVENING AS IMPROVED MOISTURE CONVERGENCE AHEAD OF THE WAVE
MOVES NORTH OVER THE AREA AND THEN PIVOTS WITH THE TRANSLATION OF
THE LOW ACROSS THE REGION. GOING QPF FORECASTS STILL LOOK ON
TRACK WITH 0.4 TO 0.75 INCHES OF RAIN IN MUCH OF NORTHERN AND
NORTHEAST IL.
MTF
&&
.DISCUSSION...
354 AM CDT
IN THE NEAR TERM...CLOSED MID-LEVEL CIRCULATION WAS LOCATED NEAR
SIOUX FALLS EARLY THIS AM...WITH ADDITIONAL SHORT WAVE ENERGY AND
ASSOCIATED CONVECTIVE CLUSTERS OVER OKLAHOMA/KANSAS. UPPER LOW IS
EXPECTED TO OPEN UP AND PHASE WITH SOUTHERN ENERGY INTO A POSITIVE
TILT TROUGH WHICH WILL MOVE SLOWLY EAST ACROSS THE REGION THROUGH
FRIDAY. WEAK SURFACE LOW PRESSURE OVER NORTHEAST KANSAS WILL DEEPEN
SLIGHTLY IN THE PROCESS...AND MOVE TO SOUTHEAST IA/WESTERN IL BY
THIS EVENING. SOUTHERLY 25-35 KT LOW LEVEL JET AND ASSOCIATED
MOISTURE TRANSPORT CURRENTLY FOCUSED INTO OK/KS/WESTERN MO WILL
GRADUALLY VEER INTO IL DURING THE DAY...AFFECTING OUR CWA
PARTICULARLY FROM LATE MORNING THROUGH THIS AFTERNOON/EARLY
EVENING. WITH SURFACE LOW PROGGED ACROSS CENTRAL/NORTHERN IL THIS
AFTERNOON AND EVENING...EFFECTIVE WARM FRONT DEVELOPS WEST-EAST
ACROSS THE SOUTHERN HALF OF THE CWA. FORECAST SOUNDINGS INDICATE
BETWEEN 500-1200 J/KG MLCAPE IN THE WARM SECTOR ALONG/SOUTH OF THE
FRONT...WHILE MID LEVEL LAPSE RATES FARTHER NORTH REMAIN MARGINAL
BUT LIKELY SUFFICIENT FOR OCCASIONAL THUNDER THERE. WHILE CLOUD
COVER AND PRECIP COVERAGE MAY LIMIT SFC/NEAR SFC BASED
DESTABILIZATION SOMEWHAT...PRESENCE OF 30-40 KT MID LEVEL FLOW AND
25-35 KT 0-6 KM BULK SHEAR DOES SUPPORT ORGANIZED CONVECTION. LINE
SEGMENTS WITH ATTENDANT SEVERE WIND/HAIL THREAT ARE EXPECTED TO BE
THE MAIN SEVERE WEATHER THREAT...THOUGH BACKED LOW LEVEL FLOW
NEAR/ALONG THE WARM FRONT COULD SUPPORT MINIMAL TORNADO POTENTIAL
PARTICULARLY IF LESS CLOUD COVER/MORE INSTABILITY WERE TO OCCUR.
MORE WIDESPREAD ISSUE IS LIKELY TO BE POTENTIAL FOR RAINFALL AMOUNTS
IN EXCESS OF 1.0 INCHES WITH RAIN/STORMS AS PWATS INCREASE TO AROUND
1.35 INCHES BY LATE AFTERNOON/EVENING. HEAVIER RAIN AND
THUNDERSTORMS SHOULD GRADUALLY MOVE OFF TO THE EAST/SOUTHEAST OF THE
CWA LATER TONIGHT...AS SFC LOW AND COLD FRONT MOVE THROUGH AND AXIS
OF BEST LOW LEVEL MOISTURE TRANSPORT VEERS ACROSS IN/OH.
SHOWERY WEATHER WILL LIKELY CONTINUE INTO FRIDAY HOWEVER...AS SLOW
MOVING UPPER TROUGH TRAVERSES THE FORECAST AREA. COOLER AIR WILL
FILTER IN AS WELL...WITH TEMPS FALLING FROM TODAYS UPPER 60S-MID 70S
TO LOWER-MID 60S NORTH TO SOUTH...AND 50S ALONG LAKE MICHIGAN.
GUIDANCE REMAINS STEADFAST IN DIGGING STRONG SHORT WAVE INTO THE
REGION AND AMPLIFYING UPPER TROUGH ACROSS THE FRIDAY NIGHT AND
SATURDAY. AS ADVERTISED EARLIER...SHARP SURFACE COLD FRONT IS
EXPECTED TO PUSH THROUGH DURING THE MORNING/MIDDAY HOURS...WITH
TEMPS LIKELY FALLING INTO THE 50S BEHIND THE FRONT DURING THE
AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE BUILDS ACROSS THE PLAINS
AND MISSISSIPPI VALLEY SATURDAY NIGHT...SETTING THE STAGE FOR A
CHILLY MOTHERS DAY. 850 MB TEMPS IN THE NEGATIVE SINGLE DIGITS
PORTEND AFTERNOON HIGHS STRUGGLING TO GET TO/ABOVE 60 ESPECIALLY
ACROSS NORTHEAST IL/NORTHWEST IN. LOWS WILL LIKELY DIP INTO THE 30S
IN SOME NORTHERN PARTS OF THE CWA SATURDAY NIGHT AND AGAIN SUNDAY
NIGHT. LOOKS LIKE ENOUGH GRADIENT/WIND TO PREVENT PATCHY FROST
DEVELOPMENT BEHIND THE FRONT SATURDAY NIGHT...THOUGH THERE COULD BE
SOME FROST IN COLDER MORE SHELTERED AREAS LATE SUNDAY NIGHT.
AS QUICKLY AS WE COOL DOWN OVER THE NEXT COUPLE OF DAYS...GUIDANCE
CONTINUES TO INDICATE THAT THE DEEP UPPER TROUGH WILL BE
PROGRESSIVE. UPPER RIDGING AND STRONG WARM ADVECTION LOOKS TO PUSH
OUR TEMPS BACK FIRMLY INTO THE 60S MONDAY...AND QUITE POSSIBLY THE
80S ESPECIALLY WEST BY TUESDAY AS 850 MB TEMPS APPROACH +20 C. WEAK
SLOW MOVING COOL FRONT SAGS ACROSS THE AREA WEDNESDAY TEMPERING THE
WARM-UP A BIT POTENTIALLY ACROSS THE NORTH...ALONG WITH THE NEXT
CHANCE OF SHOWERS/STORMS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHOWERS WITH ISOLATED/SCATTERED TSRA MID/LATE AFTERNOON.
* SHOWERS THIS EVENING...ENDING OVERNIGHT.
* LIGHT SOUTHEASTERLY WINDS BECOMING EAST BY EARLY EVENING THEN
NORTH BY LATE EVENING...WITH SOME GUSTS POSSIBLE OVERNIGHT.
* MVFR CIGS BY EARLY EVENING WITH IFR/LIFR CIGS DEVELOPING DURING
THE EVENING...IMPROVING TO MVFR FRIDAY MORNING. CMS
//DISCUSSION...UPDATED 18Z...
LINE OF SHRA/TSRA LIFTING NORTH ACROSS CENTRAL IL HAS BEGUN TO
WEAKEN AS ADDITIONAL TSRA LIFT NORTHEAST ACROSS EASTERN IL. WHILE
THIS ACTIVITY IS WEAKENING...HAVE ADJUSTED TIMING...A LITTLE
EARLIER...AS SOME SHOWER ACTIVITY WILL LIKELY REACH THE TERMINALS
BY MID AFTERNOON. ADDITIONAL SHOWERS AND PERHAPS ISOLATED TSRA
WILL CONTINUE TO DEVELOP/SPREAD NORTH ACROSS THE AREA THROUGH
EARLY THIS EVENING AS AN UPPER WAVE LIFTS NORTH. APPEARS THE BEST
THUNDER COVERAGE WILL REMAIN SOUTHEAST OF THE TERMINALS AND FOR
NOW HAVE MAINTAINED VCTS BUT TRENDS WILL NEED TO BE MONITORED FOR
UPDATES. AS AN AREA OF SURFACE LOW PRESSURE MOVES ACROSS THE AREA
LATE TONIGHT INTO THE EARLY OVERNIGHT HOURS...ADDITIONAL SHOWERS
WILL BE POSSIBLE.
THIS SURFACE LOW...AND THE LOCATION OF THE WARM FRONT AHEAD OF IT
THIS AFTERNOON WILL MAKE WIND DIRECTIONS PROBLEMATIC. SOUTHERLY
WINDS TO THE I-80 CORRIDOR LOOK ON TRACK BUT AT MDW/ORD...WINDS ON
ONE MINUTE DATA HAVE BEEN LIGHT WESTERLY TO LIGHT EASTERLY...AS
WELL AS CALM. WHILE GRADIENT REMAINS WEAK...APPEARS AS THE SURFACE
LOW APPROACHES...SOUTHEASTERLY WINDS WILL LIKELY PREVAIL AND THEN
SHIFT MORE EAST THEN NORTHEAST THIS EVENING BUT CONFIDENCE
REGARDING WINDS THROUGH THIS EVENING REMAINS LOW.
CIGS WILL LIKELY BEGIN TO FALL INTO MVFR AS PRECIP DEVELOPS AND AS
THE LOW LEVELS SATURATE WITH FLOW OFF THE LAKE...EXPECT CIGS TO
QUICKLY LOWER INTO IFR THIS EVENING AND AS THE SURFACE LOW
APPROACHES...CIGS LIKELY TO DROP INTO LIFR AND POSSIBLY VLIFR WITH
CIGS SLOWLY LIFTING FRIDAY MORNING AS THE LOW SHIFTS EAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE REGARDING SHOWERS TIMING/TRENDS.
* LOW CONFIDENCE REGARDING TSRA THIS AFTERNOON INTO THIS EVENING.
* MEDIUM CONFIDENCE REGARDING CIGS THROUGH THE PERIOD.
* LOW CONFIDENCE REGARDING WINDS THIS AFTERNOON...MEDIUM
CONFIDENCE FOR THE REST OF THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...CLEARING SKIES.
SATURDAY...VFR. GUSTY NORTHWEST WINDS.
SUNDAY AND MONDAY...VFR.
TUESDAY...STRONG SOUTHERLY WINDS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
236 PM CDT
A SLOW MOVING COLD FRONT CONTINUES TO SAG SOUTH ACROSS LAKE
MICHIGAN THIS AFTERNOON. AN AREA OF LOW PRESSURE CENTERED NEAR
SOUTHEAST IOWA THIS AFTERNOON WILL LIFT NORTHEAST ALONG THIS
FRONTAL BOUNDARY...INTO NORTHERN ILLINOIS. THEN THE LOW PRESSURE
WILL CONTINUE TO SLIDE EAST ACROSS NORTHERN ILLINOIS FRIDAY
MORNING. MEANWHILE...THE GRADIENT BEHIND THE FRONTAL BOUNDARY WILL
TIGHTEN OVER THE NORTHERN PORTION OF THE LAKE...ALLOWING
NORTH/NORTHEAST WINDS TO INCREASE TO 15 TO 25 KT WITH OCCASIONAL
GUSTS TO 30 KT. THE NORTH WINDS WILL EVENTUALLY REACH THE SOUTHERN
PORTION OF LAKE MICHIGAN...ALLOWING FOR A LONG FETCH TO SETUP.
THIS POINTS TOWARDS BUILDING WAVES FOR THE SOUTHERN TIP OF THE
LAKE...INCLUDING BOTH THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE
WATERS. HAVE HOISTED A SMALL CRAFT ADVISORY TO ACCOUNT FOR THE
HAZARDOUS WINDS/WAVES OVERNIGHT...ACROSS ILLINOIS NEARSHORE ZONES
FIRST...THEN REACHING NORTHWEST INDIANA NEARSHORE WATERS FRIDAY
MORNING.
WAVES WILL REMAIN HAZARDOUS THROUGH MUCH OF THE DAY
FRIDAY...DESPITE SLOWLY DIMINISHING WINDS AS A WEAK AREA OF HIGH
PRESSURE BUILDS OVER THE LAKE FRIDAY EVENING THROUGH EARLY
SATURDAY. THEN ANOTHER STRONG COLD FRONT WILL SLIDE EAST ACROSS
THE UPPER MIDWEST EARLY SATURDAY...REACHING LAKE MICHIGAN BY
MIDDAY. THIS WILL BRING ANOTHER TIGHT GRADIENT AND A RETURN TO
GUSTY NORTHWEST WINDS. AT THIS TIME GUSTS SHOULD BE AROUND 30
KT...HOWEVER A FEW GALE FORCE GUSTS MAY OCCUR.
LIGHT AND VARIABLE WINDS SET UP AGAIN FOR LATE SUNDAY INTO
MONDAY...AS ANOTHER AREA OF HIGH PRESSURE BUILDS ACROSS THE
WESTERN LAKES. THIS HIGH SHIFTS EAST MONDAY NIGHT...WITH YET
ANOTHER SHARP PRESSURE GRADIENT DEVLEOPING ACROSS THE WESTERN
LAKES TUESDAY WITH A POTENT STORM SYSTEM SLIDING EAST ACROSS
ONTARIO TUESDAY. THIS WILL ALLOW STRONG SOUTHERLY WINDS AHEAD OF
THE FRONTAL BOUNDARY.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM FRIDAY TO 4
AM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...7 AM FRIDAY TO 4
AM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
148 PM CDT THU MAY 9 2013
.MESOSCALE DISCUSSION...
141 PM CDT
CONTINUING TO MONITOR OBSERVATIONAL TRENDS TOWARD STORM POTENTIAL
WITH A SLIGHT RISK FOR A FEW SEVERE STORMS ACROSS MAINLY THE
SOUTHEAST QUARTER OF THE CWA OR SO PRIMARILY IN THE TIME WINDOW OF
4 PM TO 9 PM.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A WELL-DEFINED
SHORT WAVE...POSSIBLY CONVECTIVELY ENHANCED LOOKING BACK AT THE
PAST 12 HOURS...MOVING NORTHEAST FROM EAST CENTRAL MO. VAD
PROFILER DATA FROM LSX REVEALS 45 KT 700MB FLOW COINCIDENT WITH
THIS AND OTHER REGIONAL VAD DATA DEPICTS A LOW-LEVEL JET OF 35-40
KT NOSING UP IN ADVANCE OF THIS INTO CENTRAL/EAST CENTRAL IL.
AXES OF SHOWERS WITH STORMS CONTINUE TO REGENERATE IN THIS
FAVORED AREA...THOUGH MUCH OF THE LIGHTNING HAS HAD DIFFICULTY
THUS FAR REACHING NORTH OF I-74. LATEST HAND SURFACE ANALYSIS
PORTRAYS SOMEWHAT OF A MESSY PATTERN THANKS TO THE CONVECTIVE
ACTIVITY AND EVEN THE RAIN FROM EARLIER TODAY. THE SURFACE LOW
CONTINUES TO TAKE SHAPE ACROSS SOUTHEAST IA...THOUGH THE PRIMARY
WARM SECTOR IS SOMEWHAT WORKED OVER...WITH THE BEST UNTAPPED
HIGHER T/TD AIR ONLY AS FAR NORTH AS SOUTHERN IL. A CLEAR SWATH
WITH MAINLY ONLY SOME CIRRUS IS MOVING ACROSS THE AREA NORTH OF
THE SHOWER ACTIVITY AND DID ALLOW TEMPERATURES TO WARM INTO THE
70S ACROSS A LOT OF THE CWA.
SHOWERS WITH EMBEDDED STORMS SHOULD CONTINUE TO REGENERATE ACROSS
CENTRAL/EAST CENTRAL IL DURING THE MID TO LATE AFTERNOON WITH THE
AFOREMENTIONED SHORT WAVE AND LOW TO MID-LEVEL MOISTURE TRANSPORT
PROGRESSING NORTHEAST. WOULD EXPECT CONVECTION TO HAVE BETTER
CHANCES TO BECOME STRONGER IN FAR EASTERN IL TO WESTERN
IN...INCLUDING THE FAR SOUTHEAST CWA...AS THE MID-LEVEL FORCING
FOR ASCENT TRANSLATES OVER AN AIR MASS THAT IS MORE UNTAPPED.
MODIFIED RAP AND LAPS SOUNDINGS FROM NORTHWEST INDIANA DO CONTINUE
TO SHOW A CAP ALOFT IN MOST PLACES /THOUGH THE 78 DEGREES AT VPZ
BASICALLY HAS ERODED THAT/...WITH MLCAPE VALUES OF 500-800 J/KG
AND MUCAPE VALUES TOWARD 1200 J/KG. THIS INSTABILITY SHOULD NOT
INCREASE MUCH THROUGH THE COMING HOURS GIVEN THE CLOUDS AND LEAD
SHOWERS SPREADING IN. DEEP LAYER SHEAR IS FORECAST TO INCREASE TO
35-40 KT BY LATE AFTERNOON IN THIS AREA WHICH MAY SUPPORT SOME
TEMPORARY STRONGER ORGANIZED STORMS THAT COULD PRESENT AN ISOLATED
WIND THREAT. WHILE THERE LOOKS TO REMAIN A CHANCE FOR SCATTERED
CONVECTION LATER INTO THE EVE IN THESE AREAS AS THE SURFACE LOW
COMES ACROSS...THE MORE FOCUSED CONVECTION IS EXPECTED TO BE
ASSOCIATED EARLIER WITH THIS SHORT WAVE...AND CONVECTIVE ALLOWING
MODELS AGREE WITH THIS EVOLUTION.
FURTHER TO THE NORTH IN CHICAGO AND TOWARD ROCKFORD...WHILE THE
CLEARING HAS ALLOWED FOR SOME DESTABILIZATION...THE OVERALL
INSTABILITY REMAINS SOMEWHAT WEAK FOR WIDESPREAD STORM ACTIVITY.
THE POTENTIAL FOR RAIN WILL INCREASE QUICKLY AFTER 4 PM AND INTO
THE EVENING AS IMPROVED MOISTURE CONVERGENCE AHEAD OF THE WAVE
MOVES NORTH OVER THE AREA AND THEN PIVOTS WITH THE TRANSLATION OF
THE LOW ACROSS THE REGION. GOING QPF FORECASTS STILL LOOK ON
TRACK WITH 0.4 TO 0.75 INCHES OF RAIN IN MUCH OF NORTHERN AND
NORTHEAST IL.
MTF
&&
.DISCUSSION...
354 AM CDT
IN THE NEAR TERM...CLOSED MID-LEVEL CIRCULATION WAS LOCATED NEAR
SIOUX FALLS EARLY THIS AM...WITH ADDITIONAL SHORT WAVE ENERGY AND
ASSOCIATED CONVECTIVE CLUSTERS OVER OKLAHOMA/KANSAS. UPPER LOW IS
EXPECTED TO OPEN UP AND PHASE WITH SOUTHERN ENERGY INTO A POSITIVE
TILT TROUGH WHICH WILL MOVE SLOWLY EAST ACROSS THE REGION THROUGH
FRIDAY. WEAK SURFACE LOW PRESSURE OVER NORTHEAST KANSAS WILL DEEPEN
SLIGHTLY IN THE PROCESS...AND MOVE TO SOUTHEAST IA/WESTERN IL BY
THIS EVENING. SOUTHERLY 25-35 KT LOW LEVEL JET AND ASSOCIATED
MOISTURE TRANSPORT CURRENTLY FOCUSED INTO OK/KS/WESTERN MO WILL
GRADUALLY VEER INTO IL DURING THE DAY...AFFECTING OUR CWA
PARTICULARLY FROM LATE MORNING THROUGH THIS AFTERNOON/EARLY
EVENING. WITH SURFACE LOW PROGGED ACROSS CENTRAL/NORTHERN IL THIS
AFTERNOON AND EVENING...EFFECTIVE WARM FRONT DEVELOPS WEST-EAST
ACROSS THE SOUTHERN HALF OF THE CWA. FORECAST SOUNDINGS INDICATE
BETWEEN 500-1200 J/KG MLCAPE IN THE WARM SECTOR ALONG/SOUTH OF THE
FRONT...WHILE MID LEVEL LAPSE RATES FARTHER NORTH REMAIN MARGINAL
BUT LIKELY SUFFICIENT FOR OCCASIONAL THUNDER THERE. WHILE CLOUD
COVER AND PRECIP COVERAGE MAY LIMIT SFC/NEAR SFC BASED
DESTABILIZATION SOMEWHAT...PRESENCE OF 30-40 KT MID LEVEL FLOW AND
25-35 KT 0-6 KM BULK SHEAR DOES SUPPORT ORGANIZED CONVECTION. LINE
SEGMENTS WITH ATTENDANT SEVERE WIND/HAIL THREAT ARE EXPECTED TO BE
THE MAIN SEVERE WEATHER THREAT...THOUGH BACKED LOW LEVEL FLOW
NEAR/ALONG THE WARM FRONT COULD SUPPORT MINIMAL TORNADO POTENTIAL
PARTICULARLY IF LESS CLOUD COVER/MORE INSTABILITY WERE TO OCCUR.
MORE WIDESPREAD ISSUE IS LIKELY TO BE POTENTIAL FOR RAINFALL AMOUNTS
IN EXCESS OF 1.0 INCHES WITH RAIN/STORMS AS PWATS INCREASE TO AROUND
1.35 INCHES BY LATE AFTERNOON/EVENING. HEAVIER RAIN AND
THUNDERSTORMS SHOULD GRADUALLY MOVE OFF TO THE EAST/SOUTHEAST OF THE
CWA LATER TONIGHT...AS SFC LOW AND COLD FRONT MOVE THROUGH AND AXIS
OF BEST LOW LEVEL MOISTURE TRANSPORT VEERS ACROSS IN/OH.
SHOWERY WEATHER WILL LIKELY CONTINUE INTO FRIDAY HOWEVER...AS SLOW
MOVING UPPER TROUGH TRAVERSES THE FORECAST AREA. COOLER AIR WILL
FILTER IN AS WELL...WITH TEMPS FALLING FROM TODAYS UPPER 60S-MID 70S
TO LOWER-MID 60S NORTH TO SOUTH...AND 50S ALONG LAKE MICHIGAN.
GUIDANCE REMAINS STEADFAST IN DIGGING STRONG SHORT WAVE INTO THE
REGION AND AMPLIFYING UPPER TROUGH ACROSS THE FRIDAY NIGHT AND
SATURDAY. AS ADVERTISED EARLIER...SHARP SURFACE COLD FRONT IS
EXPECTED TO PUSH THROUGH DURING THE MORNING/MIDDAY HOURS...WITH
TEMPS LIKELY FALLING INTO THE 50S BEHIND THE FRONT DURING THE
AFTERNOON. UNSEASONABLY COOL HIGH PRESSURE BUILDS ACROSS THE PLAINS
AND MISSISSIPPI VALLEY SATURDAY NIGHT...SETTING THE STAGE FOR A
CHILLY MOTHERS DAY. 850 MB TEMPS IN THE NEGATIVE SINGLE DIGITS
PORTEND AFTERNOON HIGHS STRUGGLING TO GET TO/ABOVE 60 ESPECIALLY
ACROSS NORTHEAST IL/NORTHWEST IN. LOWS WILL LIKELY DIP INTO THE 30S
IN SOME NORTHERN PARTS OF THE CWA SATURDAY NIGHT AND AGAIN SUNDAY
NIGHT. LOOKS LIKE ENOUGH GRADIENT/WIND TO PREVENT PATCHY FROST
DEVELOPMENT BEHIND THE FRONT SATURDAY NIGHT...THOUGH THERE COULD BE
SOME FROST IN COLDER MORE SHELTERED AREAS LATE SUNDAY NIGHT.
AS QUICKLY AS WE COOL DOWN OVER THE NEXT COUPLE OF DAYS...GUIDANCE
CONTINUES TO INDICATE THAT THE DEEP UPPER TROUGH WILL BE
PROGRESSIVE. UPPER RIDGING AND STRONG WARM ADVECTION LOOKS TO PUSH
OUR TEMPS BACK FIRMLY INTO THE 60S MONDAY...AND QUITE POSSIBLY THE
80S ESPECIALLY WEST BY TUESDAY AS 850 MB TEMPS APPROACH +20 C. WEAK
SLOW MOVING COOL FRONT SAGS ACROSS THE AREA WEDNESDAY TEMPERING THE
WARM-UP A BIT POTENTIALLY ACROSS THE NORTH...ALONG WITH THE NEXT
CHANCE OF SHOWERS/STORMS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHOWERS WITH ISOLATED/SCATTERED TSRA MID/LATE AFTERNOON.
* SHOWERS THIS EVENING...ENDING OVERNIGHT.
* LIGHT SOUTHEASTERLY WINDS BECOMING EAST BY EARLY EVENING THEN
NORTH BY LATE EVENING...WITH SOME GUSTS POSSIBLE OVERNIGHT.
* MVFR CIGS BY EARLY EVENING WITH IFR/LIFR CIGS DEVELOPING DURING
THE EVENING...IMPROVING TO MVFR FRIDAY MORNING. CMS
//DISCUSSION...UPDATED 18Z...
LINE OF SHRA/TSRA LIFTING NORTH ACROSS CENTRAL IL HAS BEGUN TO
WEAKEN AS ADDITIONAL TSRA LIFT NORTHEAST ACROSS EASTERN IL. WHILE
THIS ACTIVITY IS WEAKENING...HAVE ADJUSTED TIMING...A LITTLE
EARLIER...AS SOME SHOWER ACTIVITY WILL LIKELY REACH THE TERMINALS
BY MID AFTERNOON. ADDITIONAL SHOWERS AND PERHAPS ISOLATED TSRA
WILL CONTINUE TO DEVELOP/SPREAD NORTH ACROSS THE AREA THROUGH
EARLY THIS EVENING AS AN UPPER WAVE LIFTS NORTH. APPEARS THE BEST
THUNDER COVERAGE WILL REMAIN SOUTHEAST OF THE TERMINALS AND FOR
NOW HAVE MAINTAINED VCTS BUT TRENDS WILL NEED TO BE MONITORED FOR
UPDATES. AS AN AREA OF SURFACE LOW PRESSURE MOVES ACROSS THE AREA
LATE TONIGHT INTO THE EARLY OVERNIGHT HOURS...ADDITIONAL SHOWERS
WILL BE POSSIBLE.
THIS SURFACE LOW...AND THE LOCATION OF THE WARM FRONT AHEAD OF IT
THIS AFTERNOON WILL MAKE WIND DIRECTIONS PROBLEMATIC. SOUTHERLY
WINDS TO THE I-80 CORRIDOR LOOK ON TRACK BUT AT MDW/ORD...WINDS ON
ONE MINUTE DATA HAVE BEEN LIGHT WESTERLY TO LIGHT EASTERLY...AS
WELL AS CALM. WHILE GRADIENT REMAINS WEAK...APPEARS AS THE SURFACE
LOW APPROACHES...SOUTHEASTERLY WINDS WILL LIKELY PREVAIL AND THEN
SHIFT MORE EAST THEN NORTHEAST THIS EVENING BUT CONFIDENCE
REGARDING WINDS THROUGH THIS EVENING REMAINS LOW.
CIGS WILL LIKELY BEGIN TO FALL INTO MVFR AS PRECIP DEVELOPS AND AS
THE LOW LEVELS SATURATE WITH FLOW OFF THE LAKE...EXPECT CIGS TO
QUICKLY LOWER INTO IFR THIS EVENING AND AS THE SURFACE LOW
APPROACHES...CIGS LIKELY TO DROP INTO LIFR AND POSSIBLY VLIFR WITH
CIGS SLOWLY LIFTING FRIDAY MORNING AS THE LOW SHIFTS EAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE REGARDING SHOWERS TIMING/TRENDS.
* LOW CONFIDENCE REGARDING TSRA THIS AFTERNOON INTO THIS EVENING.
* MEDIUM CONFIDENCE REGARDING CIGS THROUGH THE PERIOD.
* LOW CONFIDENCE REGARDING WINDS THIS AFTERNOON...MEDIUM
CONFIDENCE FOR THE REST OF THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...CLEARING SKIES.
SATURDAY...VFR. GUSTY NORTHWEST WINDS.
SUNDAY AND MONDAY...VFR.
TUESDAY...STRONG SOUTHERLY WINDS...OTHERWISE VFR.
WEDNESDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
208 AM CDT
A COLD FRONT WILL DROP SOUTHWARD DOWN THE LAKE TODAY. IN THE WAKE OF
THIS FRONT...WINDS WILL BECOME NORTH AND INCREASE UP TO 25 TO 30 KT
FOR A PERIOD INTO FRIDAY MORNING. THIS SHOULD RESULT IN SMALL
CRAFT ADVISORY CONDITIONS FOR BOTH THE INDIANA AND ILLINOIS NEAR
SHORE WATERS LATER TONIGHT THROUGH FRIDAY EVENING...AS WAVES
CLIMB ABOVE 6 FT AND NORTHERLY WINDS GUST UP IN THE 25 TO 30 KT
RANGE.
IN ADDITION TO WINDS...A WEATHER DISTURBANCE IS EXPECTED TO RESULT
IN A SURFACE WAVE OF LOW PRESSURE...WHICH SHOULD MOVE ALONG THE
FRONTAL BOUNDARY JUST SOUTH OF THE LAKE TONIGHT. THIS LOOKS TO
RESULT IN PERIODS OF SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS
THE SOUTHERN PORTION OF THE LAKE LATER TODAY AND TONIGHT.
THE WINDS SHOULD TO ABATE FOR A PERIOD LATE FRIDAY AND INTO SATURDAY
AS ANOTHER SURFACE RIDGE OF HIGH PRESSURE BUILDS OVER THE LAKE.
HOWEVER...ANOTHER COLD FRONT STILL LOOKS TO TAKE AIM ON THE LAKE
SATURDAY AFTERNOON. THIS WILL ONCE AGAIN LEAD TO A
PERIOD OF STRONGER NORTHWESTERLY WINDS INTO SUNDAY MORNING.
ANOTHER PERIOD OF LIGHT AND VARIABLE WINDS LOOKS TO SET UP AGAIN FOR
LATE SUNDAY AND INTO MONDAY OF NEXT WEEK AS ANOTHER AREA OF SURFACE
HIGH PRESSURE BUILDS ACROSS THE WESTERN LAKES. HOWEVER...ONCE THIS
HIGH SHIFTS EAST MONDAY NIGHT...IT APPEARS THAT A STRONG PRESSURE
GRADIENT WILL SET UP ACROSS THE WESTERN LAKES...AS A POTENT STORM
SYSTEM MOVES EASTWARD ACROSS CANADA. THIS LOOKS TO RESULT IN SOME
STRONG SOUTHERLY WINDS OVER THE LAKE FOR TUESDAY OF NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...1 AM FRIDAY TO 4
AM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...7 AM FRIDAY TO 4
AM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT THU MAY 9 2013
.SHORT TERM.../TODAY/
ISSUED AT 348 AM CDT THU MAY 9 2013
MAIN CONCERN THIS MORNING WILL BE CONVECTIVE TRENDS...ESPECIALLY
HEAVY RAIN POTENTIAL. COMPACT SHORT WAVE/PV ANOMALY CONTINUES TO
SLOWLY CROSS THE NE/IA BORDER. FORCING AHEAD OF FEATURE IS NOT
EXTREME...BUT COUPLED WEAK/MODERATE THERMODYNAMIC AND KINEMATIC
FORCING HAS SUSTAINED AND EVEN RECENTLY ENHANCED CONVECTION FROM SW
INTO CENTRAL IA. THIS IN SOME WAYS RESEMBLES A LOW END SHRS EVENT
BUT WITH LESS FAVORABLE ENVIRONMENT. SEVERE POTENTIAL HAS
DIMINISHED WITH NIL EFFECTIVE SHEAR AND MUCAPES ONLY SEVERAL
HUNDRED J/KG. HEAVY RAIN CONDITIONS ARE NOT GREAT EITHER WITH PWS
JUST OVER AN INCH AND WARM CLOUD DEPTHS UNDER 1K FT. HOWEVER MEAN
CELL MOTION IS CURRENTLY 230 AT ONLY 16KTS SO SUM ALL FACTORS
TOGETHER WITH SLOW MOVEMENT COULD STILL LEAD TO HEAVY RAINS WHICH
UNFORTUNATELY MAY IMPACT THE MORNING COMMUTE. ADAIR AND PERRY HAVE
ALREADY RECEIVED 1.7 INCHES SINCE MIDNIGHT. CONDITIONS CHANGE
LITTLE THROUGH THE MORNING WITH CATEGORICAL POPS...BUT OVERALL
FORCING DIMINISHES INTO THE AFTERNOON WITH LESS COVERAGE
ANTICIPATED. CANNOT ARGUE WITH 05Z HRRR DEPICTION TOO MUCH.
.LONG TERM.../TONIGHT THROUGH WEDNESDAY/
ISSUED AT 348 AM CDT THU MAY 9 2013
WE WILL BE CONTINUING TO DEAL WITH THE REMNANTS OF THE SOUTH DAKOTA
LOW AND THE SOUTHERN STREAM SHORT WAVE PUSHING ACROSS THE FORECAST
AREA TONIGHT. THE SLOW MOVEMENT OF THE STORMS IN THE WEAK FLOW OVER
IOWA HAS PROVEN TO MAKE EFFICIENT RAIN PRODUCING STORMS BUT WE LOSE
WHATEVER WEAK FORCING WE HAD IN PLACE FROM TODAY SO I DON`T SEE AS
MUCH RAINFALL TONIGHT.
SOME LINGERING PRECIP EXPECTED ACROSS THE SOUTHEAST INTO FRIDAY
MORNING THEN A BREAK AS WEAK HIGH PRESSURE BUILDS IN AT THE SURFACE
WHILE ALOFT WE ARE IN BETWEEN SYSTEMS. FRIDAY NIGHT INTO SATURDAY A
LARGE LOW PRESSURE SYSTEM OVER CANADA CARVES A TROUGH INTO THE UPPER
MIDWEST. AT THE SURFACE A STRONG COLD FRONT WILL WORK ACROSS THE
AREA BRINGING A SHOT FOR MORE RAIN AND MUCH COLDER TEMPERATURES ALONG
WITH BREEZY CONDITIONS FOR THE WEEKEND. TEMPERATURES WILL BE
DROPPING INTO THE LOW TO MID 30S SATURDAY NIGHT SO FROST HAS TO
ENTER THE THOUGHT PROCESS HERE BUT WINDS AT LEAST THROUGH THE
EVENING...AND PROBABLY ALL NIGHT ACROSS THE EAST...WILL STAY UP
ENOUGH TO MINIMIZE THE FROST THREAT. HOWEVER AT THIS POINT I THINK
IT IS ENOUGH OF A THREAT TO PUT IT IN THE FORECAST GRIDS ACROSS
NORTH FOR A FEW HOURS BEFORE DAYBREAK. THIS WILL NEED TO BE
MONITORED FOR THE POTENTIAL FOR MORE THAN JUST A MENTION.
THE COLD WILL BE SHORT LIVED AS A LARGE UPPER LEVEL RIDGE BUILDS
ACROSS THE ROCKIES THEN SHIFTS EAST EARLY NEXT WEEK. TUESDAY STILL
LOOKS VERY WARM AND WHILE I WAS NOT BOLD ENOUGH TO MENTION A 90
DEGREE READING I DID BUMP TEMPS UP INTO THE MID TO UPPER 80S. THE
UPPER RIDGE FLATTENS INTO MIDWEEK KNOCKING TEMPS BACK SEVERAL
DEGREES. A FRONTAL BOUNDARY WILL SAG INTO THE REGION PRODUCING A
CHANCE FOR THUNDERSTORMS TUESDAY NIGHT. TEMPERATURES THROUGH
MIDWEEK WHILE COOLER...WILL STILL BE SEASONAL INTO THURSDAY WITH
HIGHS IN THE 70S.
&&
.AVIATION...09/18Z
ISSUED AT 1240 PM CDT THU MAY 9 2013
UPPER LOW OVER IOWA WILL MOVE SLOWLY ESEWD WITH NUMEROUS SHOWERS
AND ISOLATED TSRA EXPECTED THIS AFTERNOON. AREAS OF IFR CIGS WILL
EXPAND SOUTH AND EAST AS TROF SHIFTS SOUTHEAST. EXPECT IFR CIGS
ACROSS THE TAF SITES TONIGHT WITH MVFR VSBYS. CONDITIONS WILL
IMPROVE ACROSS THE NRN TAFS EARLY FRIDAY MORNING WITH SKIES
CLEARING...AND IMPROVE TO MVFR CIGS ACROSS THE SRN SITES BY MID
MORNING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
LONG TERM...FAB
AVIATION...MS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
335 PM CDT THU MAY 9 2013
...UPDATED LONG TERM SECTION...
.SYNOPSIS...
ISSUED AT 221 PM CDT THU MAY 9 2013
AN ELONGATED MID LEVEL VORTICITY AXIS WAS FOUND ACROSS THE CENTRAL
PLAINS TODAY COMPLETE WITH MOISTURE AND FAIRLY COOL TEMPERATURES.
UPPER AIR OBSERVATIONS AND RAP ANALYSIS INDICATED 500/700MB
TEMPERATURES AROUND -17C/0C RESPECTIVELY. SOME INSOLATION THROUGH
EARLY AFTERNOON RESULTED IN SURFACE TEMPERATURES WARMING INTO THE
UPPER 60S TO NEAR 70 DEGREES PARTICULARLY SOUTH OF THE ARKANSAS
RIVER. THE MID LEVEL MOISTURE AXIS WAS FOUND TO BE CENTERED FROM THE
CENTRAL ROCKIES THROUGH NORTHERN KANSAS AND MUCH OF NEBRASKA. THIS
LINED UP FAIRLY WELL WITH THE MEAN 500-700MB DEFORMATION AXIS. THE
SURFACE FRONT HAD PUSHED WELL SOUTH OF THE REGION DOWN INTO SOUTHERN
OKLAHOMA, SO SURFACE-BASED INSTABILITY WAS VERY LOW ACROSS
SOUTHWESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 221 PM CDT THU MAY 9 2013
THE MAIN FORECAST CHALLENGE IS PRECIPITATION CHANCES, COVERAGE, AND
INTENSITY THIS EVENING. THE MENTIONED DEFORMATION AXIS WILL LINGER
ACROSS SOUTHEASTERN COLORADO AND WESTERN KANSAS THROUGH THIS
EVENING. THE UPDATED FORECAST POP/WX GRIDS WILL REFLECT THE HRRR
MODEL THINKING OF WEAK UPRIGHT CONVECTION FORMING NEAR A VORTICITY
CENTER ACROSS SOUTHEASTERN COLORADO. A LOOSELY ORGANIZED CLUSTER OF
CONVECTION COULD DEVELOP A COLD POOL ALLOWING THE CLUSTER OF
CONVECTION TO MOVE INTO THE SOUTHWESTERN QUARTER OR THIRD OF THE DDC
FORECAST AREA (SOUTH AND WEST OF A LAKIN TO MEADE LINE, ROUGHLY).
THE ABSENCE OF APPRECIABLE SURFACE-BASED CAPE IS EXPECTED TO KEEP
CONVECTION BELOW SEVERE LIMITS...BUT SOME GUSTS TO 50 OR 55 MPH WILL
BE POSSIBLE IF LOOSELY ORGANIZED COLD POOLS DEVELOP. ANY STORMS
WHICH IMPACT FAR SOUTHWESTERN KANSAS SHOULD BE EXITING THE AREA BY
LATE EVENING.
ON FRIDAY...WESTERN KANSAS WILL BE UNDER AN INCREASED INFLUENCE OF
NORTHWEST FLOW ALOFT AS THE MID LEVEL SHEAR AXIS CONTINUES TO PUSH
SOUTH INTO TEXAS. THIS IS EXPECTED TO RESULT IN MORE TRANQUIL
SENSIBLE WEATHER. THAT BEING SAID...MID LEVEL TEMPERATURES WILL
STILL BE COOL (700MB TEMPERATURE -2 TO 0C)...AND MIXING
CONDENSATION LEVELS WILL BE LOW AS INSOLATION ALLOWS SURFACE TEMPS
TO WARM INTO THE UPPER 60S. THE RESULT WILL BE DEVELOPMENT OF
CUMULUS AND PERHAPS AN ISOLATED SHOWER OR TO LATE IN THE DAY. THE
OFFICIAL FORECAST WILL BE DRY AS THERE WILL BE AN ABSENCE OF UPPER
LEVEL FORCING FOR ASCENT TO PROMOTE ANY ORGANIZATION OF
CONVECTION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 335 PM CDT THU MAY 9 2013
THE WEATHER PICTURE THIS WEEKEND WILL DEPICT AN UPPER LEVEL LONG
WAVE TROUGH DIGGING ACROSS THE NORTHEAST UNITED STATES AND AN UPPER
LEVEL RIDGE BUILDING ACROSS THE WESTERN UNITED STATES. MEANWHILE,
THE UPPER LEVEL LOW THAT ASSISTED IN SEVERE STORM DEVELOPMENT ACROSS
OUR AREA THE LAST COUPLE OF NIGHTS WILL SPLIT OFF FROM THE FLOW AND
MIGRATE TOWARDS NORTHERN MEXICO. THESE FEATURES WILL PLACE THE
CENTRAL HIGH PLAINS UNDER NORTHWEST FLOW ALOFT. THIS PATTERN USUALLY
GIVES WAY TO FAIR WEATHER DAYS ACROSS WESTERN KANSAS. HOWEVER, RAIN
CHANCES WILL BE POSSIBLE SATURDAY NIGHT INTO SUNDAY. HIGH PRESSURE
AT THE SURFACE WILL BE THE DOMINATE FEATURE ACROSS WESTERN KANSAS
FRIDAY NIGHT INTO SATURDAY WITH A SECOND AREA OF HIGH PRESSURE
OOZING DOWN FROM THE NORTH SATURDAY NIGHT INTO SUNDAY. A COLD FRONT
WILL BE FOUND IN BETWEEN THESE TWO AREAS OF HIGH PRESSURE ALLOWING
SOME LIFT TO OCCUR ACROSS THE PLAINS SATURDAY NIGHT. THE ATMOSPHERE
WILL BE FAIRLY DRY AS THIS FRONT MOVES THROUGH BUT THERE COULD BE A
SHOWER OR TWO THAT FORMS SATURDAY NIGHT INTO EARLY SUNDAY MORNING.
WINDS WILL GENERALLY BE LIGHT AND VARIABLE FRIDAY NIGHT INTO
SATURDAY SHIFTING TO THE NORTH BEHIND THE FRONT SATURDAY NIGHT INTO
SUNDAY. A WEAK UPPER LEVEL SHORTWAVE IS THEN DEPICTED BY THE MODELS
TO MOVE DOWN THROUGH THE NORTHWEST FLOW AND INTO KANSAS SUNDAY. IF
THIS COMES TO FRUITION, THUNDERSTORM WILL BE POSSIBLE ACROSS CENTRAL
KANSAS SUNDAY MORNING SPREADING TOWARDS SOUTH CENTRAL KANSAS AS THE
DAY PROGRESSES. OTHERWISE PARTLY CLOUDY SKIES WILL BE FOUND ACROSS
WESTERN KANSAS. LEE TROUGHING WILL ALSO BE DEVELOPING ACROSS THE
KS/CO BORDER DURING THIS TIME FRAME SHIFTING WINDS TO MORE OF A
SOUTHERLY DIRECTION. LOWS SATURDAY AND SUNDAY MORNING LOOK TO DIP
INTO THE 40S WITH HIGHS IN THE 70S SATURDAY AND SUNDAY AFTERNOON.
THE UPPER LEVEL RIDGE ACROSS THE WESTERN UNITED STATES WILL THEN
SHIFT EASTWARD INTO THE ROCKIES AND PLAINS DURING THE FIRST PART OF
NEXT WEEK. THIS FEATURE IN CONJUNCTION WITH SURFACE HIGH PRESSURE
LOCATED EAST OF KANSAS WILL BRING MOSTLY CLEAR SKIES AND DRY
CONDITIONS TO WESTERN KANSAS. LEE TROUGHING ACROSS EASTERN COLORADO
WILL CONTINUE AND BRING WARM TEMPERATURES TO THE AREA. HIGHS MONDAY
ARE FORECASTED TO REACH INTO THE 80S WITH HIGHS AROUND 90 DEGREES ON
TUESDAY. LOWS WILL GENERALLY BE IN THE 50S MONDAY AND TUESDAY
MORNING.
MID RANGE MODELS THEN SUGGEST THE UPPER LEVEL LOW ACROSS NORTHERN
MEXICO TO MOVE BACK NORTHEAST TO THE SOUTHERN PLAINS. THIS WOULD
BRING INCREASING CHANCES OF THUNDERSTORMS TO PARTS OF KANSAS MID
WEEK INTO THE FIRST PART OF THE WEEKEND. HIGHS DURING THIS TIME
FRAME WILL GENERALLY BE IN THE 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM CDT THU MAY 9 2013
A MOIST AIRMASS FROM THE LOWER TO MIDDLE TROPOSPHERE RESULTED IN
WIDESPREAD CLOUD COVER. THERE WERE AREAS OF CEILING IN THE MVFR
RANGE...PARTICULARLY IN THE HAYS AREA. WILL MAINTAIN VFR CEILING
AT THE GCK AND DDC TERMINALS THROUGH THE DAY WITH NORTH/NORTHEAST
WIND STAYING IN THE 12 TO 15 KNOT RANGE. SHOWERS AND ISOLATED WEAK
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE IN THE AFTERNOON WHICH
COULD AFFECT GCK AND HYS TERMINALS FROM 22Z TO 01Z OR SO THIS
EVENING. OTHERWISE NO ACTIVE WEATHER IS EXPECTED TONIGHT. GIVEN
THE RESIDUAL LOW LEVEL MOISTURE LEFT BEHIND THE WAVE...THERE IS A
MODERATE PROBABILITY OF A FEW HOURS IFR CEILING/VISIBILITY JUST
PRIOR TO DAYBREAK FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 68 48 71 / 20 10 10 20
GCK 45 68 47 70 / 30 10 10 20
EHA 48 69 47 71 / 30 10 10 20
LBL 48 70 48 73 / 30 10 10 20
HYS 48 69 48 68 / 20 10 20 20
P28 53 71 50 73 / 20 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
223 PM CDT THU MAY 9 2013
...UPDATED SYNOPSIS AND SHORT TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 221 PM CDT THU MAY 9 2013
AN ELONGATED MID LEVEL VORTICITY AXIS WAS FOUND ACROSS THE CENTRAL
PLAINS TODAY COMPLETE WITH MOISTURE AND FAIRLY COOL TEMPERATURES.
UPPER AIR OBSERVATIONS AND RAP ANALYSIS INDICATED 500/700MB
TEMPERATURES AROUND -17C/0C RESPECTIVELY. SOME INSOLATION THROUGH
EARLY AFTERNOON RESULTED IN SURFACE TEMPERATURES WARMING INTO THE
UPPER 60S TO NEAR 70 DEGREES PARTICULARLY SOUTH OF THE ARKANSAS
RIVER. THE MID LEVEL MOISTURE AXIS WAS FOUND TO BE CENTERED FROM THE
CENTRAL ROCKIES THROUGH NORTHERN KANSAS AND MUCH OF NEBRASKA. THIS
LINED UP FAIRLY WELL WITH THE MEAN 500-700MB DEFORMATION AXIS. THE
SURFACE FRONT HAD PUSHED WELL SOUTH OF THE REGION DOWN INTO SOUTHERN
OKLAHOMA, SO SURFACE-BASED INSTABILITY WAS VERY LOW ACROSS
SOUTHWESTERN KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 221 PM CDT THU MAY 9 2013
THE MAIN FORECAST CHALLENGE IS PRECIPITATION CHANCES, COVERAGE, AND
INTENSITY THIS EVENING. THE MENTIONED DEFORMATION AXIS WILL LINGER
ACROSS SOUTHEASTERN COLORADO AND WESTERN KANSAS THROUGH THIS
EVENING. THE UPDATED FORECAST POP/WX GRIDS WILL REFLECT THE HRRR
MODEL THINKING OF WEAK UPRIGHT CONVECTION FORMING NEAR A VORTICITY
CENTER ACROSS SOUTHEASTERN COLORADO. A LOOSELY ORGANIZED CLUSTER OF
CONVECTION COULD DEVELOP A COLD POOL ALLOWING THE CLUSTER OF
CONVECTION TO MOVE INTO THE SOUTHWESTERN QUARTER OR THIRD OF THE DDC
FORECAST AREA (SOUTH AND WEST OF A LAKIN TO MEADE LINE, ROUGHLY).
THE ABSENCE OF APPRECIABLE SURFACE-BASED CAPE IS EXPECTED TO KEEP
CONVECTION BELOW SEVERE LIMITS...BUT SOME GUSTS TO 50 OR 55 MPH WILL
BE POSSIBLE IF LOOSELY ORGANIZED COLD POOLS DEVELOP. ANY STORMS
WHICH IMPACT FAR SOUTHWESTERN KANSAS SHOULD BE EXITING THE AREA BY
LATE EVENING.
ON FRIDAY...WESTERN KANSAS WILL BE UNDER AN INCREASED INFLUENCE OF
NORTHWEST FLOW ALOFT AS THE MID LEVEL SHEAR AXIS CONTINUES TO PUSH
SOUTH INTO TEXAS. THIS IS EXPECTED TO RESULT IN MORE TRANQUIL
SENSIBLE WEATHER. THAT BEING SAID...MID LEVEL TEMPERATURES WILL
STILL BE COOL (700MB TEMPERATURE -2 TO 0C)...AND MIXING
CONDENSATION LEVELS WILL BE LOW AS INSOLATION ALLOWS SURFACE TEMPS
TO WARM INTO THE UPPER 60S. THE RESULT WILL BE DEVELOPMENT OF
CUMULUS AND PERHAPS AN ISOLATED SHOWER OR TO LATE IN THE DAY. THE
OFFICIAL FORECAST WILL BE DRY AS THERE WILL BE AN ABSENCE OF UPPER
LEVEL FORCING FOR ASCENT TO PROMOTE ANY ORGANIZATION OF
CONVECTION.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 315 AM CDT THU MAY 9 2013
ON FRIDAY NIGHT, THERE WILL BE A WEAK SHORT WAVE MOVING THROUGH THE
UPPER LEVEL DOWN SLOPE FLOW. SURFACE FRONTS WILL BE WELL SOUTH OF
SOUTHWESTERN KANSAS, BUT THERE COULD STILL BE ENOUGH MOISTURE IN
THE LOWER LAYERS FOR A FEW SHOWERS AND THUNDERSTORMS TRIGGERED BY
THE ELEVATED WAVE. THERE WILL ONLY BE SLIGHT CHANCES FOR
PRECIPITATION FRIDAY NIGHT, WITH THOSE PRECIPITATION CHANCES
SHIFTING TO THE SOUTHERN COUNTIES ALONG THE OKLAHOMA BORDER
SATURDAY. PRECIPITATION CHANCES WILL INCREASE INTO THE 30 PERCENT
RANGE DOWN SOUTH ALONG THE OKLAHOMA BORDER SATURDAY, WHERE MORE
MOISTURE WILL BE AVAILABLE. BY SUNDAY, THERE COULD BE A WARM
FRONT MOVING NORTH INTO OUR NORTHEAST SECTIONS, FROM APPROXIMATELY
WAKEENEY TO KINSLEY TO COLDWATER, AND BY THE AFTERNOON A FEW
STORMS COULD FIRE NORTHEAST OF THAT LINE. DO NOT EXPECT TO MUCH
RAINFALL WITH THE SUNDAY SYSTEM, AND RIGHT NOW I HAVE MY DOUBTS IF
ANY STORM WILL REACH SEVERE LEVELS. AFTER SUNDAY, THE REST OF THE
EXTENDED FORECAST SHOULD BE DRY, WITH A NORTHWEST FLOW BECOMING
ESTABLISHED OVER KANSAS AND AN UPPER HIGH PRESSURE AREA BUILDING
IN FROM THE WEST. THERE MAY BE A SLIGHT CHANCE FOR STORMS
WEDNESDAY NIGHT INTO THURSDAY, BUT THE ALLBLEND/CONSALL MODELS
KEPT MOST OF THE PRECIPITATION CHANCES NORTH OF OUR AREA FOR
WEDNESDAY INTO THURSDAY.
ON THE TEMPERATURE TRENDS, WE WILL SEE THE FRIDAY, SATURDAY AND
SUNDAY PERIODS FAIRLY SEASONAL, WITH LOWS IN THE MID 40S TO LOWER
50S AND HIGHS MAINLY IN THE 60S AND 70S. THEN ON MONDAY, WE
SHOULD SHIFT INTO A SIGNIFICANT WARMING TREND. MINIMUMS MONDAY
MORNING WILL BE IN THE LOWER TO MID 50S, BUT WILL WARM INTO THE
60S BY WEDNESDAY AND THURSDAY. MAXIMUM TEMPERATURES WILL LEAP
UPWARD ON MONDAY INTO THE MIDDLE TO UPPER 80S NEAR THE COLORADO
BORDER, AND TO THE LOWER 80S FROM HAYS TO LARNED TO MEDICINE
LODGE. FOR NOW, TUESDAY LOOKS TO BE THE WARMEST DAY, WITH FULL
DOWNSLOPE FLOW IN FORCE. ON TUESDAY, PARTS OF OUR WESTERN CWA,
WEST OF A SCOTT CITY TO CIMARRON TO LIBERAL LINE, MAY HAVE MAX
TEMPS PEAK AROUND 90 DEGREES, POSSIBLY THE FIRST 90+ DEGREES FOR A
FEW OF THE LOCATIONS (DDC ALREADY HIT 91 AND LBL 93, BOTH ON APR
30TH. HYS HIT 93 ON APR 28TH.) A FEW MORE CLOUDS WILL ADVECT IN ON
WEDNESDAY, SO I AM EXPECTING SLIGHTLY LOWER MAX TEMPERATURES WED,
MAINLY IN THE MID 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM CDT THU MAY 9 2013
A MOIST AIRMASS FROM THE LOWER TO MIDDLE TROPOSPHERE RESULTED IN
WIDESPREAD CLOUD COVER. THERE WERE AREAS OF CEILING IN THE MVFR
RANGE...PARTICULARLY IN THE HAYS AREA. WILL MAINTAIN VFR CEILING
AT THE GCK AND DDC TERMINALS THROUGH THE DAY WITH NORTH/NORTHEAST
WIND STAYING IN THE 12 TO 15 KNOT RANGE. SHOWERS AND ISOLATED WEAK
THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE IN THE AFTERNOON WHICH
COULD AFFECT GCK AND HYS TERMINALS FROM 22Z TO 01Z OR SO THIS
EVENING. OTHERWISE NO ACTIVE WEATHER IS EXPECTED TONIGHT. GIVEN
THE RESIDUAL LOW LEVEL MOISTURE LEFT BEHIND THE WAVE...THERE IS A
MODERATE PROBABILITY OF A FEW HOURS IFR CEILING/VISIBILITY JUST
PRIOR TO DAYBREAK FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 68 48 71 / 20 10 10 20
GCK 45 68 47 70 / 30 10 10 20
EHA 48 69 47 71 / 30 10 10 20
LBL 48 70 48 73 / 30 10 10 20
HYS 48 69 48 68 / 20 10 20 20
P28 53 71 50 73 / 20 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...BURKE
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1212 PM CDT Thu May 9 2013
.SHORT TERM...(Today through Saturday Afternoon)
Issued at 350 AM CDT THU MAY 9 2013
Conditions remain quiet early this morning as strong isentropic
lift and a veered LLJ have driven showers and thunderstorms into far
northeastern Missouri and southern Iowa. Regional radar and WV
imagery depict several developed MCV this morning, one located over
north central Kansas with two additional waves over northern and
eastern Oklahoma.
Through daybreak, short term guidance is in agreement that most of
the area will remain quiet as the vort max over north central Kansas
tracks northeast through the northwestern corner of Missouri. Have
lowered PoPs in most locations through daybreak. The stronger
southern MCV is now beginning to turn to the east as it enters
eastern Oklahoma. HRRR/RAP have struggled with this second wave, but
feel it will track into southern Missouri and gradually turn northeast
towards St. Louis after daybreak, perhaps tracking a little further
south than HRRR suggests.
Today: Subsidence in the wake of the MCV will prevent much in the
way of activity during the morning hours, and we may actually see
clouds scatter by late morning as a stationary boundary remains
draped over eastern Kansas and the northwestern third of Missouri.
Soundings indicate very low convective temperatures today, and by
late morning, we may already be approaching 70 in many areas.
Subsidence behind the departing wave will only last so long, as
stronger upper troughing remains over western Kansas. MLCAPE values
only approach 800-1000 J/KG, and shear remains marginal, thus only
anticipating a few small hail producing storms. The degree of heating
in the southeastern zones remains more questionable given the track
of the southern KS MCV this morning. Additional cloud cover and
stronger subsidence behind this wave in central Missouri may prevent
widespread redevelopment.
Thursday night-Friday: Surface troughing will push southeast
Thursday evening as upper troughing to the west begins to pivot
eastward and colder air aloft spills southward. Weak mid-level
frontogenesis may produce some lingering showers through the
overnight hours of Thursday. A north wind will prevail on Friday as
the front continues to push into southeastern Missouri and the upper
trough pivots overhead. Have lowered high temperatures a few degrees
due to the cloudy conditions and cold air advection aloft.
Temperatures may need to be lowered further in some areas.
Saturday: Weak surface ridging will slide through the area Friday
night before a much stronger cold front arrives on Saturday. Winds
will quickly turn northwest by late Saturday afternoon, turning
blustery. Temperatures will struggle to reach the lower 60s.
.LONG TERM...(Saturday Evening through Wednesday)
Issued at 350 AM CDT THU MAY 9 2013
Sunday - Tuesday:
This period will be characterized by dry weather an a marked warming
trend. Canadian high pressure will settle over the area by Sunday
morning making for a very cool start to the day. We will even flirt
with record lows (record low at MCI is 39 set in 1997). By Sunday
afternoon 850mb temps are only 2-6C which will yield highs only in
the upper 50s to lower 60s. On Monday upper level ridging that was
over the western Rockies on Sunday will begin to shift eastward into
the eastern Rockies and western Plains. This will provide for height
rises across the area. Couple that with surface high pressure
pushing off to the southeast and allowing for a return to southerly
flow and highs will rise into the upper 60s to mid 70s. By Tuesday
the upper level ridge axis moves over head. 850mb temperatures will
rise to 16-20C. And, with strong southwesterly winds providing for
good mixing, highs will be some of the warmest we have experienced
this season with highs in the low to mid 80s.
Wednesday:
Wednesday the upper level ridge will be shunted to the southeast as
an upper level trough digs into the Upper Midwest. This will send a
weak cold front into the area which will provide the next chance of
showers and thunderstorms. There is some question as to how much
moisture this system will have as the EC has a surface high pressure
over the Gulf Coast states keeping the Gulf closed. The GFS has high
pressure over the eastern Gulf with the western Gulf open and
moisture being transported into the area. Have maintained chance
POPs inherited by the initialization to account for the GFS solution.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1212 PM CDT THU MAY 9 2013
Lower ceilings across northwestern Missouri and northern Kansas
should stay north of the Kansas City terminals through tonight. MVFR
ceilings are already occurring at STJ and these should remain in
place. Ceilings will drop to fuel-alternate MVFR levels tonight as a
cold front slides south. Winds will also switch to the north behind
the front but will still remain light. Timing of when MVFR ceilings
may lift is questionable at this point but have lifted them out of
fuel-alternate state late in the valid period, though they will still
likely be MVFR.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...31
LONG TERM...73
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
342 PM CDT THU MAY 9 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 330 PM CDT THU MAY 9 2013
A FEW LIGHT SHOWERS WILL CONTINUE TO WRAP AROUND THE
SURFACE LOW ACROSS THE MIDDLE MISSISSIPPI RIVER VALLEY THROUGH THE
LATE AFTERNOON HOURS...AS IT CONTINUES TO TRANSITION FURTHER
EASTWARD. STILL CANNOT RULE OUT THE SLIGHT POSSIBILITY OF A
THUNDERSTORM OR TWO...MAINLY ACROSS PORTIONS OF NORTH CENTRAL
KANSAS...AS MESO ANALYSIS PAGE FROM SPC IS INDICATION SOME WEAK
INSTABILITY PERSISTING ACROSS THIS AREA. LATEST WRF ACTUALLY
HANGS ONTO SOME SCATTERED SHOWER ACTIVITY THROUGH THE OVERNIGHT
HOURS...BUT THIS MODEL SEEMS TO BE THE OUTLIER...SO HAVE NO MORE
THAN A FEW SPRINKLES IN THE FORECAST AFTER 00Z.
THEREAFTER...EXPECT A SURFACE RIDGE OF HIGH PRESSURE TO SLIDE
ACROSS THE FORECAST AREA FROM THE WEST OVERNIGHT...AND WITH THE
ANTICIPATED LIGHT WINDS...PARTIAL CLEARING...AND ELEVATED DEW
POINTS...EXPECT SOME FOG DEVELOPMENT OVERNIGHT. LATEST HRRR IS
HINTING AT DENSE FOG FORMING ALONG THE SPINE OF THE RIDGE AXIS
AFTER MIDNIGHT...BUT WITH SOME UNCERTAINTY STILL...ONLY REDUCED
VISIBILITIES TO 1 MILE ACROSS THE FORECAST AREA DURING THE LATE
OVERNIGHT HOURS THROUGH EARLY FRIDAY MORNING...AND HELD OFF ON
ISSUING A DENSE FOG ADVISORY FOR THE TIME BEING.
AFTER THE FOG BURNS OFF FRIDAY MORNING...EXPECT A FAIRLY NICE AND
SEASONAL DAY ACROSS THE REGION...AS THE SURFACE RIDGE WILL BE SLOW
TO PUSH EAST RESULTING IN GENERALLY LIGHT WINDS DURING THE
AFTERNOON HOURS. WITH CLEARING SKIES...RECOVERING TEMPERATURES
ALOFT...AND GOOD MIXING ANTICIPATED...EXPECT TEMPERATURES TO
RETURN TO NEAR CLIMATOLOGICAL NORMS...GENERALLY IN THE LOWER 70S
AT MOST LOCATIONS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 PM CDT THU MAY 9 2013
REALLY NO SIGNIFICANT CHANGES FOR THE FIRST PORTION OF THE LONG TERM
PERIOD...FRIDAY NIGHT THROUGH THE DAY SATURDAY. MODELS REMAIN IN
PRETTY GOOD AGREEMENT WITH THE OVERALL PATTERN...SHOWING FRIDAY
EVENING UNDER SHARP NORTHWESTERLY FLOW...A RESULT OF A TROUGH AXIS
PUSHING EAST OF THE CWA...AND RIDGING POKING INTO THE CENTRAL/NRN
WEST COAST...NORTH OF CUT OFF LOW OVER THE NM/AZ/MEX BORDER AREA.
FOCUS TURNS TO AN UPPER LEVEL LOW PRESSURE SYSTEM OVER CENTRAL
CANADA...WHICH IS EXPECTED TO SLIDE SOUTHEAST OVERNIGHT AND BY
SATURDAY MORNING IS REACHING INTO THE WRN GREAT LAKES AREA. THE
ACCOMPANYING TROUGH AXIS WILL EXTEND TO THE SOUTH AND SWING THROUGH
THE CENTRAL PLAINS PRIMARILY FRIDAY NIGHT...AND KEPT THE MENTION OF
SPRINKLES GOING ACROSS THE NRN HALF OF THE CWA. WITH THE BRUNT OF
THE LIFT WELL NE OF THE CWA...AND FORECAST SOUNDINGS CONTINUING TO
SHOW DRIER AIR IN THE AREA...DIDNT WANT TO INSERT ANY MEASURABLE
PRECIP AT THIS POINT. THE TIMING OF THE SFC COLD FRONT PUSHED
THROUGH THE CWA BY THIS DISTURBANCE HASNT CHANGED MUCH WITH THE
LATEST MODEL RUNS...AND BY 12Z SATURDAY LOOKS TO HAVE PUSHED THROUGH
TO AT LEAST THE NE/KS STATE LINE...AND EVEN A LITTLE FURTHER SOUTH
VIA THE NAM/SREF. THROUGH THE DAYTIME HOURS ON SATURDAY...SHOULD
SEE DECREASING CLOUD COVER...AND EXPECTING WINDS TO BE ON THE GUSTY
SIDE THROUGH AT LEAST THE FIRST HALF OF THE DAY...BUT SHOULD
DIMINISH ESP BY LATE AFTERNOON AS SFC HIGH PRESSURE BUILDS IN FROM
THE NORTH. THE COOLER AIRMASS ACCOMPANYING THIS FRONT IS EXPECTED
TO BRING A DROP IN HIGHS...BUT STILL EXPECTING TO REACH INTO THE
60S.
FOR SATURDAY NIGHT AND SUNDAY...MAIN CHANGE MADE TO THIS TIME FRAME
WAS TO ADD POPS TO THE FORECAST. YESTERDAY THERE WAS JUST A HINT AT
THE POSSIBILITY OF THE ACTIVITY DEVELOPING ALONG THE HIGH PLAINS
/DRIVEN BY UPSLOPE FLOW AND A WEAK MID LEVEL DISTURBANCE/ SATURDAY
AFTERNOON SLIDING SOUTHEAST AND AFFECTING AT LEAST PORTIONS OF THE
CWA...BUT NOW THE 12Z RUNS OF THE OPERATIONAL MODELS HAVE TRENDED
THIS WAY. ADDED SOME SLIGHT CHANCE AND CHANCE POPS FOR NOW...STILL
SOME SLIGHT VARIATIONS WITH TIMING/LOCATIONS...BUT MOST DO SHOW
ACTIVITY LINGERING INTO THE 12-18Z PERIOD SUNDAY. INSTABILITY IS
PRETTY PATHETIC...MUCAPE VALUES OF ARND 100 J/KG...SO WHILE AN
ISOLATED RUMBLE OF THUNDER OR TWO ARE POSSIBLE...NOT EXPECTING
WIDESPREAD THUNDERSTORMS. DEPENDING ON THE SPEED THIS ACTIVITY
EXISTS...THE HIGHS FOR THE DAY MAY NEED SOME ADJUSTMENT. TRENDED
HIGHS BACK JUST A DEGREE OR TWO OVERALL...BUT IF THINGS LINGER
LONGER THAN CURRENTLY EXPECTED...TEMPS WILL LIKELY STRUGGLE TO REACH
WHAT IS FORECAST /MID 60S TO NEAR 70/.
MONDAY AND TUESDAY...HERE COMES THE WARM UP. PAST FEW RUNS OF THE
MODELS HAVE BEEN PRETTY CONSISTENT WITH THE PATTERN ACROSS THE
CONUS...AT 12Z MONDAY THE CWA IS STILL SITTING UNDER NORTHWESTERLY
FLOW...AS THE CUT OFF LOW CONTINUES TO SIT OVER NRN MEX...AND
RIDGING ORIGINATING OFF THE WEST COAST IS EXTENDED INTO THE
ROCKIES. BY THE END OF THE DAYTIME HRS ON MONDAY AXIS LOOKS TO HAVE
SHIFTED FURTHER EAST INTO THE ROCKIES. WARMER AIR ACCOMPANYING THIS
RIDGE WILL BRING A BUMP UP IN TEMPS MONDAY...AND AGAIN TUESDAY AS
THE CWA REMAINS UNDER ITS INFLUENCE. HIGHS ON MONDAY CURRENTLY
FORECAST TO REACH THE UPPER 70S TO MID 80S...WITH TUESDAY LOOKING AT
MID 80S TO NEAR 90 DEGREES.
A LITTLE MORE UNCERTAINTY IN THE FORECAST ARISES FOR WEDNESDAY AND
THURSDAY...WITH THE POTENTIAL FOR PRECIP RETURNING. THE UPPER LEVEL
RIDGE LOOKS TO BECOME BROKEN DOWN...FROM BOTH THE LOW WHICH HAD BEEN
SET UP OVER MEX SHIFTING EAST INTO THE PLAINS...AND ADDITIONAL
ENERGY SLIDING IN FROM THE PAC NW. PLENTY OF THINGS TO IRON OUT IN
THE COMING DAYS...BUT AT THIS POINT KEPT POPS CONFINED TO THE
WED/THURS DAYTIME PERIOD...HOWEVER HAVE NO DOUBT THE TIMING WILL BE
ADJUSTED. THESE DISTURBANCES LOOK TO BRING THE POTENTIAL FOR SFC
FRONTS MOVING INTO THE AREA...WITH A SLIGHT DECREASE IN TEMPS...WITH
HIGHS BOTH DAYS CURRENTLY IN THE MID 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM CDT THU MAY 9 2013
MVFR STRATUS EXPECTED TO LINGER NEAR THE TERMINAL THROUGH THE
AFTERNOON HOURS AS MOISTURE CONTINUES TO WRAP AROUND THE SURFACE
LOW ACROSS IOWA/MISSOURI THIS AFTERNOON. MAY EVEN SEE A FEW LIGHT
SHOWERS PASS ACROSS THE TERMINAL FROM TIME TO TIME...BUT COVERED
THIS WITH A VCSH FOR THE TIME BEING AS NO SIGNIFICANT IMPACTS ARE
EXPECTED IF ANY SHOWERS DO BRUSH THE TERMINAL. EXPECT ANY SHOWER
ACTIVITY THAT DOES DEVELOP TO DIMINISH AND PUSH SOUTH BY
SUNSET...WITH SOME PARTIAL CLEARING COMBINED WITH LIGHTER WINDS TO
CONTRIBUTE TO DEVELOPMENT OF SOME BR/FG AFTER MIDNIGHT. WHILE SOME
OF THE GUIDANCE TAKING VISIBILITIES BELOW 1 MILE
OVERNIGHT...INTRODUCED ONLY IFR CIGS/VSBYS AROUND DAYBREAK WHEN
ANY FOG THAT DOES DEVELOP WILL BE THE THICKEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SAR
LONG TERM...ADO
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS ELKO NV
306 PM PDT THU MAY 9 2013
.SYNOPSIS...LINGERING MOISTURE AND UNSTABLE CONDITIONS WILL RESULT IN
CONTINUED THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND FRIDAY
AFTERNOON. HIGH PRESSURE WILL MOVE INTO THE REGION THIS WEEKEND
AND USHER IN DRIER CONDITIONS...MEAN WHILE TEMPERATURES SOAR INTO
THE EIGHTIES.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY. AS OF 18Z TODAY...THE
SYNOPTIC PATTERN FEATURED HIGH PRESSURE OVER WASHINGTON STATE WITH
A BROAD H5 TROF OVER THE GREAT BASIN AND DESERT SOUTHWEST. AN
ACTIVE PATTERN IS ON TAP AGAIN. CONVECTION WAS SLOW TO START
TODAY...HOWEVER A NUMBER OF INGREDIENTS CAME TOGETHER
BY 19Z...RESULTING IN ISOLATED TSRA...ALONG WITH A FEW ENHANCED OUTFLOWS.
PWS RANGED FROM .40 TO .55 OF AN INCH...LI`S ARE NEGATIVE AND THE
CAPES SOARED OVER 600 J/KG IN MULTIPLE ZONES. HOWEVER...THE NAM12
AND THE HRRR WERE PINGING INTO DIFFERENT LOCALES IN THE LKN CWA
FOR CONVECTION. THE BEST CONVECTION ULTIMATELY MATERIALIZED OVER
LANDER...EUREKA...AND NORTHERN NYE. ACCORDING TO THE STORM TOTAL
PRECIP ON KLRX...THE CELLS WERE CONSIDERABLY DRIER TODAY AND THE
QPF WAS SHUNTED SOUTHWARD. EXPECTING ANOTHER ROUND OF CONVECTION
FRIDAY AFTERNOON...ESPECIALLY OVER WHITE PINE AND NORTHERN NYE.
HIGH PRESSURE WILL BUILD OVER THE BATTLE BORN STATE ON
SATURDAY...EXPECTING A ROUND OF SUBSIDENCE. SENSIBLE WEATHER-WISE
EXPECTING DRY AND WARM CONDITIONS WITH VALLEY TEMPERATURES
CLIMBING INTO THE 80S.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. DRY AND VERY WARM
ON THE LATE WEEKEND...AND CONTINUED DRY AND A SLIGHT COOLING TREND
FOR THE REMAINDER OF THE WEEK.
A STRONG HIGH PRESSURE RIDGE WILL BUILD INTO THE WESTERN CONUS THIS
WEEK AND THE AXIS WILL BE OVER NEVADA FROM SOUTHWEST TO NORTHEAST ON
THE WEEKEND. TEMPERATURES WILL BE VERY WARM SUNDAY...NEAR
RECORD...WHICH ARE IN THE UPPER 80S TO LOW 90S IN MOST PLACES. SOME
PLACES IN LOWER VALLEYS OF NORTHERN NYE COUNTY MAY TWEAK THE LOWER
90S SUNDAY AND MONDAY.
THE UPPER RIDGE CREEPS EAST AS A TROUGH OF LOW PRESSURE MOVES ASHORE
IN THE PACIFIC NORTHWEST. THIS WILL PROVIDE SOME COOLER AIR STARTING
LATER MONDAY IN FAR NORTHWEST NEVADA...ADVANCING EAST AND SOUTH
THROUGH THE WEEK. EXPECTING TEMPS BY THURSDAY TO BE IN THE 70S IN
THE FAR NORTH TO THE LOW 80S IN EUREKA/LANDER/SOUTHERN ELKO/WHITE
PINE TO THE MID 80S IN NORTHERN NYE. STILL VERY PLEASANT SPRING
TEMPS.
&&
.AVIATION...ANOTHER ROUND OF -SHRA/-TSRA EXPECTED 00Z-06Z FRI.
COVERAGE WILL BE LESS THAN PREVIOUS DAY. MAIN ISSUE WILL BE GUSTY
WINDS. SOME LIGHT DAMAGE TO PROPERTY OCCURRED EARLY THURSDAY WITH
DOWNBURSTS. VFR WILL PREVAIL OUTSIDE OF ANY CONVECTION. NORTHEAST
WINDS 5-15 MPH WILL PREVAIL UNTIL ABOUT 06Z FRIDAY THEN DIMINISH.
FRIDAY WILL SEE MORE THUNDERSTORMS AND SHOWERS WITH EVEN LESS
COVERAGE THAN THURSDAY. NORTHERLY WINDS 5-15 MPH WITH GUSTY WINDS
NEAR -TSRA/SHRA.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
140 PM EDT THU MAY 9 2013
.SYNOPSIS...
A SPRAWLING UPPER LEVEL LOW IN PENNSYLVANIA WILL DRIFT NORTHEAST
INTO NEW ENGLAND TODAY. A SLOW MOVING COLD FRONT WILL CROSS THE
REGION ON SATURDAY. THESE SYSTEMS WILL KEEP THE CHANCE FOR SHOWERS
AND THUNDERSTORMS ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA TODAY TO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1130 AM UPDATE...JUST MINOR ADJUSTMENTS TO NEAR TERM GRIDS. WILL
KEEP THE MENTION OF POTNL FOR +RA THIS AFTN WITH ANY TSTA. PREV
BLO...
930 AM UPDATE...
UPR LOW CNTRD OVER NE PA MOVG NEWD TDA...WITH SVRL EMBEDDED VORT
LOBES ROTATING ARND IT. PROFILES FOR THIS AFTN SHOW GNRLY 200-400
J/KG WITH SLIGHTLY LOWER PWAT`S. RUC SUGGESTS THAT LOW LVL
CONVERGENCE ASSCD WITH EWD MOVG SFC TROF MAY COUPLE WITH AN AREA
OF ENHANCED UPR LVL DVRGNC ACRS CNTRL NY. ANY TSRA THAT DVLP
COULD DROP LCLY HEAVY RAINFALL. PREV BLO...
3 AM UPDATE...
QUIET EARLY MORNING WITH ONLY A FEW SHOWERS LEFT. SOME FOG FORMING
WITH SATURATED LOW LEVELS. UPPER LEVEL LOW IN SE PA WILL CONTINUE
NE INTO SRN NEW ENGLAND TODAY. WITH THE LOW WILL BE ANOTHER AREA
OF SHOWERS THAT WILL MOVE NNW INTO NE PA AND THE CATSKILLS THIS
MORNING THEN THE REST OF THE AREA THIS AFTN. WITH DAYTIME HEATING
THE SHOWERS WILL BECOME MORE WIDESPREAD. TSTORMS ARE POSSIBLE
MOSTLY THIS AFTN. THEY COULD HAVE HEAVY RAIN. WITH ANOTHER AREA OF
1INCH PLUS PWATS ISOLATED AREAS COULD GET AN INCH OR TWO OF RAIN.
THE HIGHEST RAIN AMOUNTS WILL AGAIN BE IN THE EAST. LITTLE
FLOODING PROBLEMS EXPECTED THOUGH WITH MOST LOCATIONS UNDER HALF
AN INCH.
LATE TONIGHT INTO EARLY FRIDAY MORNING A BREAK IN THE SHOWERS AS
THE UL LOW MOVES OFF. MORE FOG POSSIBLE WITH A WET GROUND. MORE
SHOWERS APPROACH FROM THE WEST BUT SHOULD STAY IN WRN PA AND WRN
NY UNTIL DAYLIGHT FRIDAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
3 AM UPDATE...
CONTINUED UNSETTLED...COOL AND WET. A SFC LOW AND WEAK UPPER LEVEL
TROF MOVES ENE FROM ILLINOIS TO NY FRIDAY TO SATURDAY. THE LOW
STRENGTHENS WITH TIME...WHILE AN UL JET COUPLET SET UP AS THE
SOUTHERN JET MOVES TOWARD THE MID ATLANTIC. AHEAD OF THE LOW AND
TRAILING COLD FRONT BETTER MOISTURE AND HIGH TEMPS IN THE L70S
MOVE IN. THIS WILL DESTABILIZE THE LOWER LEVELS AND THE SHORT
WAVES WILL ADD LIFT. WIND FIELDS INCREASE AND TURN WITH HEIGHT FOR
SOME SPEED AND DIRECTIONAL SHEAR. WINDS NOT STRONG BUT ENOUGH TO
KEEP SHOWERS AND THUNDERSTORMS GOING ONCE THEY FORM LATE MORNING
INTO THE AFTERNOON. LIFT IS MARGINAL WITH CAPE UNDER 500. WIND
WILL BE THE BIGGEST THREAT. SPC HAS PA IN A SLIGHT CHC OF SEVERE.
ANOTHER HALF INCH OF RAIN IS EXPECTED FRI AFTN AND EVE. WILL NEED
TO WATCH FOR ISOLATED FLASH FLOODING WITH THUNDERSTORMS.
FRIDAY NIGHT THE SFC LOW MOVES FROM LAKE ONTARIO TO QUEBEC BUT THE
TRAILING COLD FRONT DOES NOT MAKE MUCH PROGRESS UNTIL SATURDAY.
THE BEST CHC OF SHOWERS WILL BE SAT MIDDAY AND AFTN IN NE PA AND
THE CATSKILLS. POSSIBLY SOME THUNDERSTORMS WITH WEAK LIFT AND
INSTABILITY. SAT NGT THE SFC FRONT MOVES EAST AND DAYTIME HEATING
WILL WANE CAUSING THE DIURNAL SHOWERS TO DIE. POPS DROP FROM
LIKELY SAT TO LOW CHC SAT OVERNIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
4 PM WED UPDATE... A TRANSITIONAL PATN IS EXPECTED THIS PD...AS
GLOBAL MODEL/WPC CONSENSUS POINTS TO A FAIRLY AMPLIFIED ERN
CANADIAN/NERN CONUS TROUGH EARLY IN THE PD...FOLLOWED BY A
TEMPORARY FILLING OF THIS FEATURE...AND MORE ZONAL PROGRESSION BY
NEXT TUE-WED.
SENSIBLE WX-WISE...MUCH CHILLIER TEMPS ARE FORESEEN SUN-MON...WITH
SCTD WRAP-ARND -SHRA ANTICIPATED...WITHIN THE CYCLONIC FLOW
REGIME. IN FACT...SOME WET SNOW FLAKES ARE EVEN PSBL LATE SUN
NGT INTO EARLY MON...SPCLY OVER THE HIGHER TERRAIN. THE OTHER PSBL
HIGHLIGHT OF THIS PD IS PROBABLE FROST/FREEZE CONDS...BOTH SUN AND
MON NGTS...IF ANY CLEARING CAN DVLP.
TEMPS SHOULD MODERATE TUE-WED (BACK INTO THE 60S AND 70S)...AS THE
FLOW TURNS SWLY...AND HGTS BUILD OVER THE ERN CONUS. BY WED...AN
APPROACHING UPR-LVL WAVE AND SFC FRNT COULD TRIGGER SOME
SHWRS...AND THUS WE`VE ADDED CHC POPS AT THIS EARLY JUNCTURE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
18Z THU UPDATE... AN AREA OF SHRA WILL SLOWLY PIVOT ACRS PTNS OF
THE RGN THIS AFTN FROM W TO E...PROVIDING OCNL RESTRICTIONS
(MAINLY MVFR) AT KELM/KITH/KBGM/KAVP. KRME AND KSYR SHOULD STAY VFR.
EARLY THIS EVE...THE SHRA SHOULD DISSIPATE EARLY (BY
00-02Z)...LEAVING MAINLY VFR CONDS THE FIRST PART OF THE NGT.
HOWEVER...BY/AFTER 06Z...WE`RE ANTICIPATING FOG AND PATCHY ST CLDS
TO DVLP (MVFR TO IFR RESTRICTIONS)...AGN MAINLY TARGETING
KELM/KITH/KBGM/KAVP.
CONDS SHOULD IMPROVE BY EARLY FRI (12-14Z)...WITH VFR THEN
PREVALENT THE REMAINDER OF THE VALID TAF PD.
S TO SW SFC WINDS THIS AFTN (5-8 KT)...WILL BECOME LGT AND VRBL
OVERNIGHT...THEN INCREASE OUT OF THE S AND SW FRI (8-15 KT).
OUTLOOK...
FRI NGT INTO SAT...RESTRICTIONS LIKELY IN SHRA.
SUN THROUGH TUE...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...TAC
SHORT TERM...TAC
LONG TERM...MLJ
AVIATION...MLJ
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
128 PM CDT THU MAY 9 2013
.AVIATION...
FOR THE 18Z TAFS...THE THUNDERSTORM FORECAST FOR AREA AIRPORTS IS
THE PRIMARY FORECAST CHALLENGE THROUGH THE VALID FORECAST PERIOD.
THE FORECAST FOR THUNDERSTORMS IN AND AROUND AREA AIRPORTS IS
COMPLICATED BY THE EXISTENCE OF MULTIPLE FORCING MECHANISMS FOR
STORM DEVELOPMENT...AND THE WIDESPREAD PRESENCE OF AVAILABLE
MOISTURE AND INSTABILITY TO SUPPORT STORMS ACROSS THE REGION. IN
GENERAL THIS FORECAST CLOSELY FOLLOWS THE MODELED SIMULATED
REFLECTIVITY ADVERTISED IN THE 12Z TEXAS TECH WRF.
FOR THE DFW AREA...EXPECT THAT WIDESPREAD RAIN SHOWERS WITH
EMBEDDED THUNDERSTORMS WILL PERSIST THROUGH 21Z. DO NOT EXPECT ANY
SIGNIFICANT CHANGE IN INTENSITY OF THIS ACTIVITY THROUGH 21Z. FOR
KACT...A SEVERE THUNDERSTORM OVER HAMILTON AND CORYELL COUNTIES
WAS MOVING DUE EAST TOWARDS THE AIRPORT AT THE TIME OF THIS
DISCUSSION. A BASIC LINEAR EXTRAPOLATION OF ITS 18Z MOVEMENT BRINGS
THE STORM OVER KACT AT 1915Z...SO THIS IS THE TIME THAT WAS USED
FOR THIS LINE OF STORMS IN THE TAF. IF THE LINE MAINTAINS ITS
INTENSITY AS IT BUILDS INTO MCLENNAN COUNTY...WILL HAVE TO AMEND
TO INCREASE WIND SPEEDS AND MENTION HAIL AT THE AIRPORT. THIS LINE
OF STORMS IS EXPECTED TO MOVE EAST OF KACT AFTER 21Z.
AS THE LINE OF STRONG TO SEVERE THUNDERSTORMS MOVES EAST OF THE
INTERSTATE 35 CORRIDOR AFTER 21Z...SUBSIDENCE IS EXPECTED TO CAUSE
A DECREASE IN THE COVERAGE AND INTENSITY OF PRECIPITATION AROUND
ALL AREA AIRPORTS. ATTENTION THEN TURNS TO THE NORTHWEST WHERE
THUNDERSTORMS WERE ALREADY DEVELOPING NEAR THE COLD FRONT/DRYLINE
INTERSECTION NEAR SNYDER TX. THE 12Z TEXAS TECH WRF INDICATES THAT
THIS ACTIVITY WILL GROW UPSCALE INTO A SQUALL LINE THAT WILL MOVE
EAST AND APPROACH DFW AREA TAF SITES BY 01Z. THIS LINE OF
STORMS...IF IT EVOLVES...IS EXPECTED TO MOVE EAST QUICKLY ONLY
REMAINING OVER THE METROPLEX FOR A COUPLE OF HRS. BEHIND THIS LINE
OF STORMS...SOME LIGHT RAIN MAY PERSIST FOR A FEW HRS AS THE LOW
LEVEL JET INTERACTS WITH THE OUTFLOW FROM THE LINE OF STORMS.
THE FRONT IS EXPECTED TO MOVE THROUGH THE DFW AREA FRIDAY
MORNING...WITH A FRONTAL PASSAGE OF AROUND 15Z AT THIS TIME. THE
FRONT IS EXPECTED TO MOVE THROUGH KACT A COUPLE OF HOURS LATER.
THE FRONT IS NOT EXPECTED TO HAVE A STRONG PUSH FROM LOW PRESSURE
ALOFT...SO THE FRONTAL TIMING WILL LIKELY DEPEND ON THUNDERSTORM
ACTIVITY ALONG AND BEHIND THE FRONT. THE MORE STORMS
OVERNIGHT...THE FASTER IT WILL TEND TO MOVE SOUTH. WHENEVER THE
FRONT MOVES THROUGH...IT IS EXPECTED TO PROVIDE ENOUGH LIFT FOR
SOME SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS AT AREA TAF
SITES.
CAVANAUGH
&&
.UPDATE...
CONVECTIVE COMPLEX CONTINUES TO DEVELOP IN THE CONCHO
VALLEY...MOVING NORTHEAST INTO NORTH AND CENTRAL TEXAS. SMALL HAIL
HAS BEEN REPORTED WITH THE STRONGER STORMS IN THE CONCHO VALLEY
BUT THE STORMS CONTINUE TO REMAIN BELOW SEVERE LIMITS FOR NOW.
A COMPLICATED CONVECTIVE EVOLUTION IS EXPECTED TODAY WITH TWO OR
THREE COMPLEXES/ROUNDS OF STORMS LIKELY TO AFFECT THE REGION
THROUGH TONIGHT. ANALYZING THE LATEST HI-RES AND SHORT TERM MODEL
DATA...LATEST THINKING IS NOT TOO FAR OFF FROM THE PREVIOUS
FORECAST. THE ONGOING COMPLEX OF STORMS WILL CONTINUE TO MOVE
NORTHEAST WITH ADDITIONAL CONVECTIVE DEVELOPMENT AS WE APPROACH
THE MIDDAY AND EARLY AFTERNOON HOURS. THIS MCS WILL LARGELY AFFECT
THE SOUTH AND SOUTHWESTERN HALVES OF THE CWA. IT IS POSSIBLE THAT
AN ADDITIONAL COMPLEX OF STORMS COULD DEVELOP OFF THIS INITIAL
COMPLEX THIS AFTERNOON. SEVERE STORMS EMBEDDED WITHIN THE MCS ARE
LIKELY...BUT THE CLOUD COVER ACROSS THE REGION WILL PLAY A KEY
ROLE IN HOW WIDESPREAD THE SEVERE STORMS ARE THIS AFTERNOON. AMPLE
MOISTURE IS ALREADY IN PLACE ACROSS THE REGION WITH STEEP LAPSE
RATES ABOVE THE MORNING CAP. THIS CAP IS EXPECTED TO WEAKEN
THROUGHOUT THE DAY AND IF BREAKS IN THE CLOUDS OCCUR THIS
AFTERNOON...INSTABILITY COULD JUMP TO OVER 3000 J/KG ACROSS THE
REGION...PER THE LATEST RAP SOUNDINGS. THIS WOULD INCREASE THE
SEVERE WEATHER POTENTIAL WITH LARGE HAIL AND DAMAGING WINDS BEING
THE MAIN SEVERE WEATHER THREATS. THESE STORMS WILL GENERALLY MOVE
OFF TO THE EAST LATE THIS AFTERNOON AND EVENING.
THE OTHER FOCUS FOR STORM DEVELOPMENT THIS AFTERNOON IS ALONG THE
DRYLINE. THE DRYLINE IS CURRENTLY WELL TO OUR WEST IN FAR WEST
TEXAS BUT IS EXPECTED TO BULGE NEAR OUR NORTHWEST COUNTIES LATE
THIS AFTERNOON. MODELS CONTINUE TO DEVELOP STORMS ALONG THE
DRYLINE THIS AFTERNOON WITH A THREAT FOR SEVERE STORMS. SEVERAL OF
THE MODELS MERGE THE STORMS ALONG THE DRYLINE INTO A COMPLEX OF
STORMS THAT MOVES EAST/SOUTHEAST THIS EVENING AND TONIGHT. MAIN
SEVERE WEATHER THREATS WOULD ALSO BE LARGE HAIL AND DAMAGING WINDS
WITH THESE STORMS.
FOR THE UPDATE...ADJUSTED CLOUD COVER UP ACROSS THE REGION AND
LOWERED HIGH TEMPERATURES INTO THE LOW TO MID 70S ACROSS MOST OF
THE REGION. THE EXCEPTION WILL BE IN THE NORTHWEST WHERE
TEMPERATURES WILL LIKELY REACH THE LOWER 80S UNDER PARTLY CLOUDY
TO MOSTLY CLOUDY SKIES. ALSO INCREASED AND ADJUSTED POPS WITH THE
HIGHEST POPS STILL GENERALLY ALONG AND SOUTH OF INTERSTATE 20.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT THU MAY 9 2013/
MORNING WATER VAPOR IMAGERY FEATURES SEVERAL SWIRLING VORTICES
ACROSS THE CONUS ALONG WITH A COUPLE OF COMPLEXES OF THUNDERSTORMS
AND A STEADY STREAM OF HIGH LEVEL PACIFIC MOISTURE VIA THE
SUBTROPICAL JET. OF IMPORTANCE TO NORTH TEXAS WEATHER OVER THE
NEXT 36 HOURS WILL BE THE LARGE BUT RATHER WEAK UPPER LOW OVER THE
SOUTHWEST US AND ITS ASSOCIATED EMBEDDED VORTICITY MAXIMA THAT
PERIODICALLY ROTATE AROUND AND EJECT EASTWARD. TIMING OF THESE
FEATURES AND THEIR ASSOCIATED FORCING FOR ASCENT WILL MAKE FOR A
MODERATELY CHALLENGING FORECAST THROUGH FRIDAY.
00Z MODEL DATA/UPPER AIR DATA AND WATER VAPOR IMAGERY CONFIRM THE
PRESENCE A SHORTWAVE WHICH IS CURRENTLY MOVING ACROSS NORTHWEST MEXICO
THIS MORNING. THIS IS A LITTLE FASTER THAN THE GUIDANCE SUGGESTED
FROM YESTERDAY. TIMING THIS FEATURE BASED ON ITS CURRENT SPEED WOULD
SUGGEST THAT THE STRONGEST FORCING FOR ASCENT ASSOCIATED WITH IT
WOULD BEGIN TO OVERSPREAD SOUTHWEST TEXAS SHORTLY AND SPREAD INTO
NORTH TEXAS THROUGH MID MORNING. MOST OF THE HIGH RESOLUTION
GUIDANCE QUICKLY DEVELOPS SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH LATE MORNING ACROSS THE EDWARDS PLATEAU AND SPREADS THEM
EAST-NORTHEAST INTO OUR CWA. THERE IS EVEN A STRONG SIGNAL WITHIN
THE LOWER RES GLOBAL GUIDANCE WHICH SUPPORTS THIS SCENARIO.
OBVIOUSLY WITH A MUCH EARLIER START TO CONVECTIVE ACTIVITY...THE
OVERALL SEVERE WEATHER THREAT WOULD BE LOWER...HOWEVER...DEEP
LAYER WIND FIELDS ARE QUITE A BIT STRONGER THIS MORNING THAN THEY
WILL BE BY THIS EVENING. FORECAST SOUNDINGS ACROSS THE CWA SHOW
THE CONTINUED PRESENCE OF STEEP MID LEVEL LAPSE RATES...AND WITH
AMPLE EFFECTIVE DEEP LAYER SHEAR...WOULD NOT RULE OUT INITIAL
ELEVATED SUPERCELL DEVELOPMENT THROUGH LATE MORNING. LARGE HAIL
WOULD BE THE PRIMARY THREAT DURING THIS TIME. THUNDERSTORMS THAT
DEVELOP THROUGH THE MORNING WOULD LIKELY TEND TO CLUSTER INTO AN
MCS AND SPREAD EAST OR SOUTHEASTWARD. UNFORTUNATELY THERE IS LARGE
SPREAD WITHIN THE GUIDANCE AS TO HOW FAR NORTH ANY SUCH COMPLEX OF
STORMS WOULD SPREAD...BUT CURRENT THINKING IS THAT BEST CHANCES
THROUGH THIS AFTERNOON WILL GENERALLY BE SOUTH OF INTERSTATE 20.
WILL HAVE HIGHEST POPS ACROSS THE SOUTHWEST COUNTIES THIS MORNING
AND SPREAD THEM ACROSS THE SOUTHERN AND SOUTHEAST THROUGH THIS EVENING.
ANOTHER AREA OF CONCERN FOR CONVECTIVE DEVELOPMENT WILL BE ALONG
THE FRONT/DRYLINE INTERSECTION ACROSS NORTHWEST TEXAS LATE THIS
AFTERNOON AND EVENING. THIS AREA APPEARS TO BE A LITTLE MORE
QUESTIONABLE AS MORNING/EARLY AFTERNOON CONVECTION WOULD LIKELY
INHIBIT ADDITIONAL DEVELOPMENT. WITH BEST FORCING FOR ASCENT
SPREADING ACROSS NORTH TEXAS DURING THE FIRST HALF OF THE
DAY...WEAK SUBSIDENCE WOULD LIKELY FOLLOW IN ITS WAKE...ESPECIALLY
IF AN ORGANIZED COMPLEX OF STORMS DEVELOPS FARTHER SOUTH. THAT
BEING SAID...FORECAST SOUNDINGS FOR LATE THIS AFTERNOON ACROSS
NORTHWEST TEXAS SHOW ONLY A WEAKLY CAPPED UNSTABLE PROFILE. THIS
WEAK CAPPING MAY BE THE MODELS FAILURE TO CAPTURE MORE ROBUST
SUBSIDENCE IN THE WAKE OF EARLIER CONVECTION. EITHER WAY...THE
HIGH RESOLUTION GUIDANCE VARIES ON THE DEVELOPMENT OF
THUNDERSTORMS THROUGH EARLY EVENING ACROSS NORTHWEST TEXAS
DEPENDING ON WHAT HAPPENS FARTHER SOUTH. GIVEN THAT THERE WILL BE
A FAIRLY LARGE UNPERTURBED AREA OF MODERATELY STRONG INSTABILITY
AND AT LEAST SOME FOCUSED LOW LEVEL FORCING ALONG THE
FRONT/DRYLINE AND POSSIBLY RESIDUAL OUTFLOW BOUNDARIES FROM EARLY
MORNING CONVECTION ACROSS OKLAHOMA...THINK AT LEAST ISOLATED SURFACE
BASED THUNDERSTORMS WILL DEVELOP BY THIS EVENING ACROSS PARTS OF
NORTHWEST TEXAS. A LOCALLY HIGHER SEVERE WEATHER THREAT WOULD
EXIST ACROSS OUR NORTHWEST COUNTIES WITH LARGE HAIL BEING THE MAIN
THREAT IF THESE STORMS DO DEVELOP.
AS THE COLD FRONT SAGS SOUTH LATER TONIGHT...RAIN AND THUNDERSTORM
CHANCES WILL PROGRESSIVELY SHIFT FARTHER SOUTH INTO CENTRAL TEXAS.
THE FRONT WILL LIKELY GET HUNG UP ACROSS THE HILL COUNTRY BY EARLY
FRIDAY MORNING. SCATTERED THUNDERSTORMS ARE AGAIN EXPECTED ALONG
THE FRONT WITH BEST CHANCES BEING ACROSS THE SOUTHERN COUNTIES.
WITH STEEP LAPSE RATES STILL IN PLACE ACROSS THIS AREA...SEVERE
HAIL WILL REMAIN A THREAT WITH THIS ACTIVITY. ACTIVITY TOMORROW
AFTERNOON SHOULD AGAIN DEVELOP INTO AN MCS AND HEAD SOUTHEAST OUT
OF THE AREA. FRONTAL BOUNDARY WOULD GET PUSHED FARTHER SOUTH BY
SATURDAY WITH POPS TAPERING BACK DOWN TO JUST 20 PERCENT ACROSS
THE SOUTHERN COUNTIES.
WITH THE MAIN UPPER LOW DRIFTING ACROSS NORTHWEST MEXICO OVER THE
WEEKEND...THERE SHOULD BE A FEW QUIET DAYS TO START NEXT WEEK. THE
UPPER LOW FINALLY GETS KICKED OUT BY MIDWEEK WITH ANOTHER SHOT OF
SHOWERS AND THUNDERSTORMS BY WEDNESDAY.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 76 66 79 59 77 / 90 60 20 20 10
WACO, TX 75 64 80 61 78 / 80 60 30 30 20
PARIS, TX 75 61 79 56 76 / 40 60 20 20 10
DENTON, TX 76 62 78 57 77 / 50 60 20 20 10
MCKINNEY, TX 75 62 78 57 78 / 60 60 20 20 10
DALLAS, TX 76 67 81 61 79 / 90 60 20 20 10
TERRELL, TX 77 63 80 58 78 / 70 60 20 20 10
CORSICANA, TX 75 65 80 61 77 / 80 60 30 30 20
TEMPLE, TX 75 64 80 60 76 / 80 60 50 30 20
MINERAL WELLS, TX 77 61 78 57 80 / 60 50 20 20 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
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