Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/04/12
AREA FORECAST DISCUSSION
NWS PUEBLO CO
400 PM MDT MON APR 2 2012
.SHORT TERM...
(TONIGHT AND TUESDAY)
...STRONG SPRING STORM TAKING AIM ON SOUTH CENTRAL AND SOUTHEAST
COLORADO...
MODELS IN REMARKABLE AGREEMENT WITH THE OVERALL DETAILS OF CLOSED
UPPER LOW ACROSS EAST CENTRAL NEW MEXICO SHIFTING EASTWARD THEN
NORTHEASTWARD INTO THE TX/OK PANHANDLE BY TUES AFTERNOON. FRONT HAS
ALREADY SLAMMED THROUGH EASTERN CO EARLIER TODAY...WITH PEAK GUSTS
IN EXCESS OF 60 MPH ACROSS PORTIONS OF EL PASO COUNTY. HRRR AND
LOCAL 4 KM WRF INDICATED TWO PERIODS OF STRONGER WINDS...ONE THIS
MORNING...AND ANOTHER THIS AFTERNOON INTO EARLY THIS EVENING. JUST
PICKED UP A GUST TO 50 KTS AT KPUB AIRPORT AROUND 230 PM...SO
PERHAPS THE SHORT RANGE MODELS DO HAVE A HANDLE ON THIS.
THUS...WILL MAINTAIN HIGH WIND WARNINGS THROUGH 03Z.
INTERESTINGLY...HRRR SUGGESTS CORE OF STRONGER WINDS MAY EXPAND
ACROSS MORE OF THE SOUTHEAST PLAINS AND CONTINUE THROUGH
06Z...HOWEVER WITH TIGHTEST PRESSURE GRADIENT ALREADY PAST...WILL
LEAVE CURRENT EXPIRATION AT 03Z AND LET LATER SHIFTS MONITOR THE
TRENDS TO DECIDE IF EXTENSION IN TIME...OR EXPANSION IN AREA IS
NECESSARY. LOCAL 4 KM WRF BACKED OFF SOME ON WIND GUSTS AFTER 03Z
FOR ALL BUT PERHAPS EASTERN EL PASO COUNTY. OTHER AREA OF CONCERN
FOR HIGH WINDS CONTINUES ALONG THE EASTERN SIDE OF THE SAN LUIS
VALLEY AS WINDS ACCELERATE THROUGH THE PASSES IN THE SANGRES AND
SPILLS INTO THE VALLEY. HRRR AND 12Z 4KM WRF STILL PAINT THIS
SCENARIO IN THE LATEST RUNS...WITH PEAK WINDS OCCURRING NOW THROUGH
00Z...WITH GUSTS STARTING TO TAIL OFF BY 03Z. ALS HAD A WIND GUST
TO 54 MPH AFTER NOON...WHICH IS VERY CLOSE. SUSPECT LOCAL AREAS TO
THE WEST HAD HIGHER GUSTS. AGAIN...WRF KEEPS GUSTS UP AROUND 70 MPH
THROUGH 03Z BEFORE TAILING OFF...SO CURRENT HIGHLIGHT LOOKS ON
TARGET.
FIRST LOBE OF ENERGY WILL ROTATE AROUND THE CLOSED LOW INTO
SOUTHEAST COLORADO THIS EVENING. SNOW IS ALREADY OCCURRING ACROSS
THE EAST FACING SLOPES OF THE SANGRES/WETS...THOUGH ITS BEEN PRETTY
LIGHT SO FAR AS MOISTURE LAYER REMAINS SHALLOW. HOWEVER...RADARS TO
THE SOUTH SHOW ECHOES EXPANDING ACROSS NORTHEAST NM WITH SOME
EMBEDDED CONVECTION EVIDENT VIA LIGHTNING STRIKES. SHOULD SEE THIS
BAND OF SHOWERS SPREAD NORTHWARD THROUGH THE EVENING WITH SNOW
SPREADING NORTHWARD AND RAMPING UP ACROSS THE PIKES PEAK AREA AFTER
03-06Z. NICE ISENTROPIC UPGLIDE EVIDENT IN BOTH NAM AND GFS ON THE
300K SFC...AND MODELS IN GOOD AGREEMENT WITH HEAVY QPF AMOUNTS
ACROSS A LARGE PORTION OF THE SOUTHEAST PLAINS THROUGH
TUESDAY...PARTICULARLY NEAR THE MOUNTAINS. SNOW LEVELS WILL START OFF
AROUND 7000 FEET...BUT DROP TO AROUND 5000 FEET OVERNIGHT. TIMING
OF THE DROP IN TEMPERATURES AND THE RESIDUAL WARMTH OF THE GROUND
WILL PLAY A BIG ROLE IN HOW MUCH SNOW ACCUMULATES ACROSS THE LOWER
ELEVATIONS OF THE I-25 CORRIDOR SUCH AS SOUTHERN EL PASO AND PUEBLO
COUNTIES. HOWEVER...WITH GOOD MODEL CONSENSUS AND IMPRESSIVE TROWAL
ALOFT EXPECTED TO OVERWHELM DOWNSLOPE OFF THE PALMER AT LEAST
THROUGH THE 06Z TO 15Z WINDOW...HAVE OPTED TO ISSUE A WINTER WEATHER
ADVISORY FOR THE LOWER ELEVATIONS OF THE I-25 CORRIDOR...INCLUDING
COLORADO SPRINGS AND PUEBLO. SNOWFALL AMOUNTS WILL LIKELY EXHIBIT A
WIDE RANGE WITH SOME MELTING OFF ROAD SURFACES AT TIMES...BUT
ANYWHERE FROM 2 INCHES ON THE GRASS...TO AROUND 6 INCHES NEAR THE
MOUNTAINS SEEMS PLAUSIBLE. WITH A PERIOD OF EAST TO NORTHEAST WINDS
FUNNELING UP THE ARKANSAS RIVER...AND UPSLOPING ALONG THE WEST SIDE
OF THE LA GARITAS/AND EASTERN SAN JUANS...WILL INCLUDE THESE AREAS
IN A WINTER WEATHER ADVISORY AND RUN IT THROUGH 00Z. BIGGEST WINNER
IN THIS EVENT WILL BE THE EAST SLOPES OF THE SANGRES AND WETS 40 TO
50 KTS OF NORTHEAST UPSLOPE WILL RESULT IN 1 TO 2 FEET OF
SNOW...WITH HIGHER AMOUNTS ( UP TO 30 INCHES) ACROSS THE HIGHER
ELEVATIONS. REMAINDER OF THE HEADLINES IN GOOD SHAPE. TROWAL
EVENTUALLY PULLS OFF TO THE NORTHEAST ON TUESDAY WITH SNOW WINDING
DOWN FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON TUESDAY. -KT
.LONG TERM...
(TUESDAY NIGHT-MONDAY)
...TIMING AND LOCATION OF UPPER LEVEL STORM LIFTING OUT ACROSS THE
SE PLAINS TUESDAY NIGHT THE MAIN FORECAST PROBLEM...
TUESDAY NIGHT-WEDNESDAY...SLIGHT MODEL DIFFERENCES ON TIMING AND
LOCATION OF UPPER LOW LIFTING OUT ACROSS THE SE PLAINS CONTINUE AND
HAVE TAILORED FORECAST TOWARDS THE NAM AND EC WHICH HAVE THE LOW
ACROSS EXTREME NORTHEAST NEW MEXICO AT 00Z WED AND THEN SLOWLY LIFT
IT OUT ACROSS WESTERN OKLAHOMA INTO CENTRAL OKLAHOMA THROUGH THE DAY
ON WEDNESDAY. ONGOING WRAP AROUND PRECIPITATION ACROSS THE EASTERN
MTS AND I-25 CORRIDOR TUESDAY AFTERNOON SLOWLY SHIFTS EAST AND
DIMINISHES FROM WEST TO EAST OVERNIGHT...AS UPPER LEVEL FLOW BECOMES
MORE NORTHWEST. COULD SEE SOME ADDITIONAL LIGHT ACCUMULATIONS OF A
COUPLE OF INCHES ACROSS THE NORTH AND EAST FACING SLOPES OF THE
EASTERN MTS AND ALONG WITH PALMER DVD AND RATON MESA TUESDAY EVENING
WITH THINGS WINDING INTO WEDNESDAY MORNING. TEMPERATURES ALOFT WARM
FROM WEST TO EAST THROUGH THE DAY ON WEDNESDAY...AS UPPER LEVEL
RIDGING BUILDS INTO THE STATE WITH HIGHS WARMING BACK TO AT OR
SLIGHTLY ABOVE SEASONAL AVERAGES...THOUGH HAVE TAPERED BACK HIGHS A
TAD IN EXPECTED SNOW COVERED AREAS.
WEDNESDAY NIGHT-MONDAY...WARMER AND DRIER WEATHER CONTINUES TO BE
PROGGED THROUGH THE PERIOD...WITH MODERATE TO STRONG WESTERLY FLOW
EXPECTED ACROSS THE REGION AS SEVERAL SHORT WAVES MOVE ACROSS THE
NORTHERN ROCKIES. ONE WAVE MOVES ACROSS THE REGION THURSDAY NIGHT
AND FRIDAY...WITH BREEZY TO WINDY CONDITIONS AND POSSIBLE CRITICAL
FIRE WEATHER CONDITIONS ON FRIDAY...DEPENDING ON HOW MUCH PRECIP
FALLS. PASSING WAVE SENDS A DRY COLD FRONT ACROSS THE PLAINS FRIDAY
WITH SLIGHTLY COOLER TEMPERATURES ACROSS THE AREA ON SATURDAY.
ANOTHER WAVE POSSIBLE MOVES ACROSS THE NORTHERN ROCKIES ON SUNDAY
NIGHT...WITH A BACKDOOR COLD FRONT POSSIBLE BRINGING IN ENOUGH LOW
LEVEL MOISTURE FOR A FEW SHOWERS ACROSS THE EASTERN PLAINS ON
MONDAY. HOWEVER...WILL KEEP A DRY FORECAST IN TACT THROUGH THE
PERIOD. -MW
&&
.AVIATION...
IFR CIGS/VIS EXPECTED TO AFFECT THE TAF SITES TONIGHT AS STRONG
SYSTEM MOVES ACROSS NORTHERN NEW MEXICO. STRONG NORTH WINDS IN THE
30 TO 45 KT RANGE WILL CONTINUE AT KCOS AND KPUB BEFORE DECREASING
TOWARDS 06Z. KALS WILL CONTINUE TO SEE EAST WINDS IN THE 25 TO 40
KT RANGE THROUGH EARLY EVENING WITH PERIODS OF BLDU. HEAVIEST SNOW
WILL IMPACT KCOS AND KPUB BETWEEN 06Z-18Z PERIOD WITH POTENTIAL FOR
A COUPLE INCHES OF SNOW...MAINLY ON GRASSY SURFACES AT KPUB...TO
AROUND 2 TO 5 INCHES AT KCOS. WITH WARM GROUND...THERE WILL BE SOME
MELTING AT TIMES AT KCOS...BUT PAVED SURFACES COULD BECOME SLUSHY
AND SNOWPACKED UNDER THE HEAVIER SNOW BANDS. KALS COULD SEE AN INCH
OR TWO AS WELL. RAIN/SNOW SWITCH OVER WILL OCCUR AROUND 03Z FOR
KCOS AND KALS...AND AROUND 06Z FOR KPUB. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM MDT
TUESDAY FOR COZ058-060>063-076-077.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT
TUESDAY FOR COZ083-085-086.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM MDT
TUESDAY FOR COZ066>068.
WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1136 AM MDT MON APR 2 2012
.AVIATION...
STRONG WINTER STORM WILL CONTINUE AFFECTING THE REGION THROUGH
EARLY WEDNESDAY. AT KCOS AND KPUB...STRONG NORTHERLY WINDS WILL
CONTINUE THROUGH AT LEAST MIDDAY TUESDAY..WITH A MODEST DECREASE IN
WIND SPEEDS MONDAY EVENING. ISENTROPIC UPGLIDE WILL BE STRONG
ENOUGH TONIGHT TO OVERCOME THE DOWNGLIDE RESULTING FROM THE STRONG
NORTHERLY WINDS. TAFS HAVE SNOW WITH IFR CEILINGS AND VISIBILITIES
FROM MONDAY EVENING THROUGH AROUND 12Z TUESDAY. ACCUMULATIONS OF 2
TO 5 INCHES ARE FORECAST FOR KCOS. AT KPUB ACCUMULATIONS WILL BE
LIMITED TO AN INCH OR TWO ON GRASSY SURFACES. AFTER 12Z
TUESDAY...DOWNGLIDE FROM STRONG NORTHERLY WINDS WILL LIMIT
PRECIPITATION AT KCOS AND KPUB. HOWEVER...HEAVY PRECIPITATION IS
LIKELY NORTH OF KCOS AND SOUTH OF KPUB. AT KALS...STRONG EASTERLY
WINDS WILL WEAKEN DURING THE EVENING. UPPER LEVEL FORCING SHOULD
BE STRONG ENOUGH TO PRODUCE SNOW AT KALS OVERNIGHT...WITH CHANCES
FOR SNOW DECREASING AFTER 12Z TUESDAY. --PGW--
&&
.PREV DISCUSSION... /ISSUED 1017 AM MDT MON APR 2 2012/
UPDATE...
LATEST HRRR AND LOCAL 4 KM WRF ALSO SHOWING ANOTHER INCREASE IN
THE WIND GUSTS LATER THIS AFTERNOON THROUGH THIS EVENING
ALONG/SOUTH OF THE PALMER DIVIDE. THUS WILL BE EXTENDING THE HIGH
WIND WARNING THROUGH 03Z. -KT
PREV DISCUSSION... /ISSUED 1007 AM MDT MON APR 2 2012/
UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
06/06
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1017 AM MDT MON APR 2 2012
.UPDATE...
LATEST HRRR AND LOCAL 4 KM WRF ALSO SHOWING ANOTHER INCREASE IN
THE WIND GUSTS LATER THIS AFTERNOON THROUGH THIS EVENING
ALONG/SOUTH OF THE PALMER DIVIDE. THUS WILL BE EXTENDING THE HIGH
WIND WARNING THROUGH 03Z. -KT
&&
.PREV DISCUSSION... /ISSUED 1007 AM MDT MON APR 2 2012/
UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
.MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
.BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1007 AM MDT MON APR 2 2012
.UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
&&
.PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
..BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ084>086-089-
093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1005 AM EDT MON APR 2 2012
.SYNOPSIS...
CANADIAN HIGH PRESSURE IS BUILDING INTO THE REGION TODAY INTO
TUESDAY AS DEEPENING LOW PRESSURE OVER THE ATLANTIC MOVES EAST. WEAK
LOW PRESSURE MOVING ACROSS SOUTHEAST CANADA TUESDAY NIGHT WILL
DRAG A TRAILING COLD FRONT ACROSS WEDNESDAY MORNING. CANADIAN HIGH
WILL THEN BUILD BACK IN THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ABUNDANT LOW LEVEL MOISTURE COMBINED WITH SFC HEATING IS ALLOWING
STRATOCUMULUS FIELD TO EXPAND AS IT MOVES SOUTH OUT OF SOUTHERN
NEW ENGLAND AND THE HUDSON VALLEY. SOME SPRINKLES WITH THE BAND
OVER NEW HAVEN THAT WILL MOVE SOUTH OVER CENTRAL LONG ISLAND
BETWEEN 10 AM AND NOON.
LATEST RUC AND 06Z NAM SUGGESTING THAT THIS MOISTURE MIXES OUT AND
SKIES CLEAR THIS AFTERNOON AS PER PREVIOUS FCST.
WIND...CURRENTLY GUSTING TO AROUND 25 MPH...INCREASE THIS AFTN
WITH ADDITIONAL MIXING TO 850 HPA. EXPECT FREQUENT GUSTS IN THE 25
TO 35 MPH RANGE AT WE MIX DOWN APPROX 80% OF THE 850 WIND.
TEMPS ON TRACK FOR LOWER 50S INTERIOR TO MID 50S CITY/COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
DEEP TROUGH AXIS GRADUALLY SLIDES EAST TONIGHT...WITH INTENSE SURFACE
LOW PUSHING OUT TO SEA. RIDGING SURFACE/ALOFT BUILDS IN ON
TUESDAY.
TIGHT GRADIENT AND GUSTY WINDS CONTINUE OVER THE REGION
TONIGHT...WITH SECONDARY SHOT OF CAA IN WAKE OF BACKSIDE SHORTWAVE.
TEMPS EXPECTED TO HOLD NEAR SEASONABLE WITH MIXED LOW-LEVELS DESPITE
CAA AND CLEAR SKIES.
TEMPS ARE EXPECTED TO FALL INTO THE UPPER 20S ACROSS INTERIOR
ZONES LATE TONIGHT. FOR COASTAL AREAS...TEMPS EXPECTED TO DROP
INTO THE LOWER TO MID 30S CITY/COAST. THE COLDEST SURGE OF AIR
SHOULD BE ACROSS EASTERN SECTIONS...WITH SE COASTAL CT HAVING THE
BEST CHANCE OF SUB-FREEZING AIR DRAINING TO THE COAST DOWN THE CT
RIVER VALLEY. AS OF 1 APRIL...WE ARE ISSUING FROST/FREEZE
WATCHES/WARNINGS/ADVISORIES FOR COASTAL SECTIONS. A FREEZE WATCH
FOR SE COASTAL CT IN CURRENTLY IN PLACE.
GUSTY NW WINDS TO START
THE DAY ON TUESDAY...GRADUALLY RELAXING THROUGH THE AFTERNOON.
OTHERWISE MOSTLY SUNNY SKIES...EXCEPT FOR SOME LATE DAY CIRRUS
AHEAD OF A NORTHERN STREAM SHORTWAVE. WITH MODERATING TEMPS ALOFT
AND GOOD MIXING...HIGH EXPECTED TO REBOUND TO ABOVE NORMAL
LEVELS...GENERALLY UPPER 50S INTERIOR TO LOWER 60S CITY/COAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER VORTEX WILL MEANDER ABOUT THE EASTERN CANADIAN
PROVINCES/MARITIMES THROUGH THE MIDDLE OF THE WEEK...BEFORE A CUTOFF
LOW APPROACHING FROM CENTRAL CANADA REINFORCES IT THU AND FRI.
MEANWHILE...A SPLIT FLOW DEVELOPS ACROSS NOAM EARLY IN THE WEEK WITH
A CUTOFF LOW DEVELOPING OVER THE SW AND AN AMPLIFIED RIDGE
DOWNSTREAM.
MOST OF THE DYNAMICS ASSOCIATED WITH THE CUTOFF LOW MOVING ACROSS SE
CANADA AND NEW ENGLAND TUE NIGHT/WED WILL REMAIN TO OUR N.
HOWEVER...ECMWF AND 21Z SREF MEAN BOTH CONTINUES TO PRODUCE SOME
LIGHT QPF ASSOCIATED WITH THE COLD FROPA LATE TUE NIGHT/EARLY WED
MORNING AND THERE COULD BE ENOUGH MOISTURE/LIFT FOR A FEW
SHOWERS...SO HAVE CONTINUED WITH SLIGHT CHANCE POP.
DEEP NW FLOW WILL THEN PREVAILS THROUGH FRI AS THE VORTEX OVER THE
CANADIAN MARITIMES SLOWLY DEPARTS AND RIDGING BUILDS IN FROM CANADA.
IT NOW APPEARS THAT THE NORTHERN BRANCH OF THE POLAR JET WILL BE
DOMINANT INTO LATE WEEK...SO HAVE HIGHER CONFIDENCE THAT HIGH
PRESSURE WITH DRY WEATHER SHOULD CONTINUE THROUGH THE WEEKEND...WITH
A GRADUAL WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE DEEPENING EAST OF THE DELMARVA COAST WILL CONTINUE TO
TRACK OUT TO SEA TODAY.
MAINLY VFR TODAY. THERE ARE SOME MVFR CIGS NORTH OF THE REGION
DROPPING SOUTH...WHICH COULD PRODUCE A BRIEF PERIOD OF MVFR CIGS.
ONCE THESE MVFR CIGS DROP SOUTH OF THE REGION...WE SHOULD REMAIN
VFR THROUGH THE DAY.
WINDS WILL CONTINUE TO RAMP UP THIS MORNING AS THE LOW INTENSIFIES.
NORTHWEST WINDS TODAY 20-30KT WITH SOME GUSTS TO AROUND 35KT. WINDS
DIMINISH SLIGHTLY AFT 23-00Z...THEN GUSTS END ROUGHLY IN THE 5-6Z
PERIOD.
IN THE EXTENDED TAFS...GUSTS KICK IN AGAIN AFT 12Z TUE.
ALL WIND DIRECTIONS N OF 310 TRUE TODAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KLGA FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KTEB FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KHPN FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KISP FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS TO 25 KT POSSIBLE.
.WEDNESDAY...CHANCE OF CIGS BELOW 3FT EARLY...THEN VFR.
.THURSDAY...VFR.
.FRIDAY...VFR.
&&
.MARINE...
A TIGHT PRESSURE GRADIENT IN THE WAKE OF RAPIDLY DEEPENING LOW
PRESSURE WILL INCREASE GUSTS TO AROUND GALE FORCE THIS MORNING. A
GALE WARNING REMAINS IN EFFECT FOR ALL THE FORECAST WATERS THROUGH
THIS AFTERNOON. WINDS ALOFT APPEAR TO SUPPORT JUST MARGINAL
GALES...BUT DEEP MIXING SHOULD KEEP THE NEARSHORE THREAT THROUGH
THIS AFTERNOON. GUSTS EXPECTED TO FALL BELOW GALE LATE THIS
AFTERNOON...BUT SCA GUSTS STILL EXPECTED OVER ALL WATERS INTO LATE
TONIGHT WITH STILL TIGHT GRADIENT AND A SECONDARY SHOT OF CAA.
WINDS EXPECTED TO DIMINISH TO MARGINAL NEARSHORE SCA GUSTS TUESDAY
MORNING...CONTINUING THROUGH THE AFTERNOON. OCEAN SEAS FALLING
BELOW SCA TUESDAY MORNING.
QUIET TUE NIGHT INTO WED MORNING AS A COLD FRONT APPROACHES AND THEN
MOVES THROUGH. SCA CONDITIONS ARE LIKELY ON ALL WATERS AFTER FROPA
WED AFTERNOON AND ON THE OCEAN WED NIGHT...WITH A CHANCE THAT NEAR
SHORE GUSTS COULD REACH MINIMAL GALE FORCE WED AFTERNOON IN THE
HARBOR AND THE OCEAN/SOUND WATERS SURROUNDING NYC AND WESTERN LONG
ISLAND. QUIET THEREAFTER AS HIGH PRESSURE BUILDS FROM THE N.
&&
.FIRE WEATHER...
GENERALLY 1/4 TO 1/2 INCH OF RAIN AREA-WIDE OVER THIS WEEKEND
WILL ALLOW FOR INITIALLY MOIST FINE FUELS. AN ENHANCED THREAT OF
BRUSH FIRE GROWTH/SPREAD IS POSSIBLE THIS AFTERNOON WITH
SEASONABLY MILD TEMPS...HUMIDITY LEVELS LOWERING INTO THE 20
PERCENT RANGE ALONG WITH STRONG NORTHERLY WINDS HELPING TO DRY THE
FUELS. WILL HOLD OFF ON AN SPS...ALLOWING DAYSHIFT TO COORDINATE
ON FUEL CONDITIONS WITH OUR FIRE OFFICIALS.
ONCE FINE FUELS DRY OUT...ENHANCED THREAT OF BRUSH FIRE
GROWTH/SPREAD IS EXPECTED TUESDAY LATE MORNING/AFTERNOON WITH
MILD TEMPS...RH VALUES FALLING INTO THE LOWER 20S AND WINDS GUSTS
AROUND 25 MPH.
A COLD FRONTAL PASSAGE WILL PRODUCE SOME LIGHT PRECIP LATE TUE
NIGHT INTO EARLY WED MORNING...BUT THEN WX CONDITIONS SHOULD
BECOME CONDUCIVE TO FIRE GROWTH/SPREAD WED AFTERNOON...WITH NW
WINDS GUSTING TO 30-35 MPH AND RH LOWERING TO 25-30 PERCENT.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE REMAINDER OF
THE WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
CTZ010>012.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/NV
NEAR TERM...JST
SHORT TERM...NV
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/NV
FIRE WEATHER...
HYDROLOGY...GOODMAN/NV
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1012 PM EDT TUE APR 3 2012
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA LATE TONIGHT. A BACKDOOR
COLD FRONT WILL APPROACH FROM THE NORTH WEDNESDAY NIGHT. A WAVE OF
LOW PRESSURE DEVELOPING ALONG THIS FRONT WILL CAUSE IT TO STALL
ACROSS NORTHERN PORTIONS OF THE FORECAST AREA THURSDAY...BEFORE
THE SYSTEM TRACKS OFFSHORE AND PULLS THE FRONT THROUGH THE REGION
FRIDAY. COOLER HIGH PRESSURE WILL THEN RETURN FOR THE WEEKEND INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATE TUESDAY EVENING...THUNDERSTORMS CONTINUED TO FIRE ON
MESOSCALE BOUNDARIES ACROSS THE SOUTHEAST AND WERE CLOSING IN ON
THE FORECAST AREA FROM THE SOUTH...WEST AND NORTHWEST. A
PERSISTENT THUNDERSTORM COMPLEX WILL PUSH THROUGH SOUTHERN
COUNTIES/ALONG THE ALTAMAHA RIVER DURING THE NEXT COUPLE OF
HOURS...JUSTIFYING A PERIOD OF LIKELY/CATEGORICAL POPS THERE.
SCATTERED THUNDERSTORMS WILL ALSO DEVELOP ALONG MESOSCALE
BOUNDARIES INTO WESTERN/INLAND COUNTIES. ALSO OF INTEREST...AN
EXPANDING THUNDERSTORM COMPLEX WAS PROMPTING WARNINGS ACROSS
SC MIDLANDS. IF THIS COMPLEX HOLDS TOGETHER...THUNDERSTORMS COULD
IMPACT NORTHERN COUNTIES OF THE FORECAST AREA AFTER MIDNIGHT.
GIVEN HAIL/DOWNDRAFT CAPES DEPICTED BY THE LATE EVENING SPC
MESOANALYSIS...CANNOT RULE OUT AN ISOLATED SEVERE THUNDERSTORM
WITH DAMAGING MICROBURSTS AND LARGE HAIL TONIGHT. HOWEVER...THE
THREAT FOR SEVERE WEATHER REMAINS LOW AND SHOULD CONTINUE TO
DIMINISH OVERNIGHT.
LATE EVENING INSTABILITY AND SUPPORT FROM COMPLEX/MESOSCALE
BOUNDARIES SUGGEST THAT THUNDERSTORMS WILL PERSIST WELL INTO THE
OVERNIGHT. HOWEVER...THE 00Z NAM AND THE 01Z RUC13 SUGGEST THAT
DIURNAL STABILIZATION WILL TRANSLATE TO DISSIPATING CONVECTION
OVERNIGHT. THUS...CONTINUED TO TREND POPS DOWN TO SLIGHT CHANCE
WELL AFTER MIDNIGHT...BUT CONFIDENCE IN POPS DIMINISHES
OVERNIGHT...AND ADDITIONAL ADJUSTMENTS COULD BE REQUIRED.
MEANWHILE...GIVEN LOW LEVEL MOISTURE AND RELATIVELY LIGHT WINDS...
ADDED A MENTION OF PATCHY FOG ALL AREAS OVERNIGHT. FOG COULD
BECOME LOCALLY DENSE IN AREAS THAT RECEIVED OR WILL RECEIVE RAIN.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LEVEL SHORTWAVE WILL STEADILY TRACK DUE EAST
ACROSS THE GULF COAST STATES AND NORTHERN FLORIDA THROUGH WEDNESDAY
AFTERNOON. AT THE SURFACE...A TROUGH WITH AN EMBEDDED COLD FRONT
WILL TAKE SHAPE ACROSS VIRGINIA/NORTH CAROLINA BY LATE IN THE DAY.
SOUTH OF THIS FRONT ACROSS THE FORECAST AREA...DEEP OFFSHORE FLOW
SUGGESTS THE SEABREEZE WILL BE PINNED TO THE COAST...WITH AREAS AWAY
FROM THE SHORE WARMING WELL INTO THE LOW TO MID 80S. THERE IS
GENERAL CONSENSUS AMONG THE 12Z GFS AND NAM SOLUTIONS THAT SCATTERED
SHOWERS/THUNDERSTORMS WILL DEVELOP DURING THE
AFTERNOON...CONSIDERING DECENT INSTABILITY AND DEWPOINTS IN THE
LOWER 60S DURING THE PEAK HEATING HOURS.
MODEL SOUNDINGS FOR WEDNESDAY AFTERNOON ARE INDICATIVE OF A DEEPLY
MIXED BOUNDARY LAYER AND INVERTED V SHAPE...WHILE WEAK UPPER LEVEL
ENERGY IS PROGRESSING OVER THE FORECAST AREA BEHIND THE SHORTWAVE
TROUGH ALOFT. ALTHOUGH THE BEST POTENTIAL FOR SEVERE WEATHER WILL
BE FARTHER TO THE NORTH WHERE THE FRONT WILL ENHANCE FORCING...AN
ISOLATED SEVERE STORM COULD BE POSSIBLE WEDNESDAY AFTERNOON/EARLY
EVENING. HOWEVER...CONFIDENCE AND COVERAGE ARE TOO LOW TO WARRANT
MENTION IN THE HAZARDOUS WEATHER OUTLOOK AT THIS TIME.
WEDNESDAY NIGHT...SCATTERED CONVECTION IS EXPECTED TO GRADUALLY
DIMINISH DURING THE EVENING HOURS WITH THE LOSS OF DIURNAL HEATING
AND INSTABILITY...WITH RAIN CHANCES BELOW 15 PERCENT AFTER
MIDNIGHT. WARM SOUTH/SOUTHWEST FLOW AND RESIDUAL CLOUD COVER WILL
SUPPORT MILD LOW TEMPERATURES IN THE LOW TO MID 60S.
THURSDAY...THE SURFACE TROUGH AND BACKDOOR FRONT WILL HAVE
MADE SOME PROGRESS SOUTHWARD TOWARD THE NORTH CAROLINA/SOUTH
CAROLINA BORDER BY DAYBREAK THURSDAY. A CLOSED UPPER LOW TRACKING
ACROSS THE GULF COAST STATES AND SOUTHERN TENNESSEE VALLEY WILL
HELP DEVELOP A SURFACE LOW ALONG THE LINGERING WEST/EAST ORIENTED
FRONT LATE IN THE DAY. AS THE SURFACE WAVE TAKES SHAPE JUST
DOWNSTREAM OF THE UPPER LEVEL LOW...THE BACKDOOR FRONT COULD SHIFT
INTO THE FAR NORTHERN SECTIONS OF THE FORECAST AREA BY THURSDAY
AFTERNOON. THICK CLOUD COVER WILL KEEP TEMPERATURES A FEW DEGREES
COOLER IN THE UPPER 70S TO LOW 80S. CONVECTIVE COVERAGE WILL
STEADILY INCREASE THROUGH THE LATE MORNING HOURS...WITH
THUNDERSTORM CHANGES BECOMING LIKELY FOR MUCH OF THE FORECAST AREA
THURSDAY AFTERNOON AND EVENING.
THERE REMAINS SOME CONCERN REGARDING THE POTENTIAL FOR ORGANIZED
SEVERE DEVELOPMENT THURSDAY AFTERNOON. DEWPOINTS WILL ONCE AGAIN
LINGER IN THE LOW 60S...WHILE LIFTED INDICES AND CAPE VALUES
SUGGEST MODERATE INSTABILITY BY EARLY/MID AFTERNOON. OF SOME
ADDITIONAL CONCERN IS INCREASING BULK SHEAR AND HELICITY
VALUES...AS WELL AS ENHANCED FORCING ALONG THE LINGERING
FRONT. STORM PREDICTION CENTER HAS PLACED THE FORECAST AREA WITHIN
A 5 PERCENT RISK FOR SEVERE DEVELOPMENT ON DAY 3. WILL CONTINUE
TO MONITOR MODEL TRENDS AND ALLOW LATER FORECAST SHIFTS TO DETERMINE
THE NEED TO INCLUDE SEVERE MENTION IN THE HAZARDOUS WEATHER OUTLOOK
FOR THURSDAY.
THURSDAY NIGHT INTO FRIDAY...THE SURFACE LOW WILL DEEPEN AHEAD OF
THE UPPER LEVEL TROUGH THURSDAY NIGHT...WITH BOTH FEATURES PULLING
OFF THE SOUTHEAST COAST DURING THE EARLY MORNING HOURS ON FRIDAY.
THIS WILL DRAG THE BACKDOOR FRONT THROUGH THE AREA...WITH DECENT
SHOWER/THUNDERSTORM POTENTIAL PERSISTING THURSDAY NIGHT THROUGH
FRIDAY AFTERNOON. COOL NORTHEAST FLOW BEHIND THE FRONT WILL
SUPPRESS HIGH TEMPERATURES CONSIDERABLY LOWER THAN PREVIOUS
DAYS...LIKELY ONLY REACHING THE UPPER 60S NORTH TO MID 70S
SOUTHEAST GEORGIA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PRETTY DECENT MODEL AGREEMENT THIS PERIOD GIVEN THE TIME
FRAME...ESPECIALLY THROUGH SUNDAY. HIGH PRESSURE WILL BUILD FROM THE
NORTH FRIDAY NIGHT AS LOW PRESSURE MOVES FARTHER OFFSHORE AND AWAY
FROM THE AREA. RAIN CHANCES WILL BE ENDING FROM WEST TO EAST WITH
DRY CONDITIONS LIKELY BY DAYBREAK SATURDAY FOR ALL AREAS. SOME
LINGERING CLOUDS ALONG WITH A CHILLY NORTH/NORTHEAST FLOW SHOULD
KEEP TEMPERATURES BELOW NORMAL AROUND 70 NORTH/MID 70S SOUTH. THE
COOL AIR MASS WILL THEN LINGER INTO EARLY NEXT WEEK...REINFORCED BY
A DECENTLY STRONG COLD FRONT ON TUESDAY. FOR THE FIRST TIME IN A
WHILE IT APPEARS TEMPERATURES WILL BE CLOSE TO NORMAL...ESPECIALLY
OVER THE WEEKEND.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
AT KCHS...BRIEF PERIODS OF VFR CONDITIONS ARE POSSIBLE...BUT
OVERALL PREVAILING MVFR CEILINGS THIS EVENING ARE EXPECTED TO
DETERIORATE TO IFR OR LOWER CONDITIONS OVERNIGHT/EARLY WEDNESDAY.
AT KSAV...ADDED A MENTION OF CBS AND SHIFTING/GUSTY
WINDS 02Z-06Z TONIGHT TO ACCOUNT FOR IMPACT OF CONVECTION THAT
WILL APPROACH THE TERMINAL FROM THE S/SW. EXPECT AMENDMENTS IF
THUNDERSTORMS ARE EXPECTED TO DIRECTLY IMPACT THE TERMINAL.
OTHERWISE...VFR THIS EVENING...THEN LOW LEVEL MOISTURE SHOULD
SUPPORT AT LEAST PERIODS OF MVFR OR LOWER CONDITIONS OVERNIGHT
INTO WEDNESDAY MORNING.
THUNDERSTORMS WILL REDEVELOP WEDNESDAY AFTERNOON...THUS MAINTAINED
A MENTION OF CBS TO BOTH TERMINALS.
EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE EARLY
THURSDAY IN LOW CLOUDS/FOG...WITH INCREASED SHOWER/TSTM POTENTIAL
LATER THURSDAY THROUGH FRIDAY.
&&
.MARINE...
THUNDERSTORMS AND GUSTY/SHIFTING WINDS WILL IMPACT AT LEAST GA
WATERS DURING THE NEXT COUPLE OF HOURS...AND THUNDERSTORMS COULD
PUSH INTO SC WATERS AFTER MIDNIGHT. OUTSIDE THUNDERSTORMS...
S/SE WINDS WILL VEER T TO SW AS A WEAK WARM FRONT LIFTS NORTH OF
THE REGION LATE TONIGHT. WINDS OUTSIDE THUNDERSTORMS SHOULD
REMAIN 15 KT OR LESS. SEAS WILL REMAIN IN THE 2-4 FT RANGE.
WEDNESDAY THROUGH SUNDAY...A BACKDOOR COLD FRONT WILL APPROACH
FROM THE NORTH WEDNESDAY/WEDNESDAY NIGHT. THE FRONT WILL LIKELY
REMAIN JUST NORTH OF THE WATERS UNTIL FRIDAY...WHEN LOW PRESSURE
DEPARTS THE COAST AND HIGH PRESSURE BUILDS IN FROM THE NORTH.
CONDITIONS SHOULD REMAIN BELOW ADVISORY LEVELS UNTIL LATE
FRIDAY...WHEN NORTH/NORTHEAST WINDS SURGE BEHIND THE DEPARTING
LOW SYSTEM AND BUILDING HIGH PRESSURE. AT LEAST SMALL CRAFT
ADVISORY CONDITIONS ARE POSSIBLE ACROSS MOST OF THE MARINE ZONES
BY FRIDAY NIGHT. THERE IS A SMALL CHANCE THAT GALE FORCE GUSTS
COULD OCCUR FRIDAY NIGHT INTO SATURDAY...MAINLY ACROSS THE
CHARLESTON NEARSHORE WATERS AND GEORGIA WATERS BEYOND 20 NM...BUT
CONFIDENCE TOO LOW TO MENTION IN THE HAZARDOUS WEATHER OUTLOOK AT
THIS TIME. SEAS WILL ALSO BE INCREASING WITHIN THE FAVORABLE
NORTHEAST FLOW...POSSIBLY TO NEAR 10 FT OUT TO 60 NM BY LATE
FRIDAY. WINDS LOOK TO SUBSIDE SUNDAY...BUT IT WILL LIKELY TAKE A
BIT LONGER FOR SEAS TO DROP BELOW ADVISORY LEVELS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...79
LONG TERM...RJB
AVIATION...SPR
MARINE...SPR/79
AREA FORECAST DISCUSSION...CORRECTED
NWS CHARLESTON SC
308 PM EDT MON APR 2 2012
.SYNOPSIS...
A WEAK FRONT WILL DROP SOUTH INTO THE REGION TONIGHT AND LINGER
THROUGH TUESDAY BEFORE LIFTING NORTH TUESDAY NIGHT. ANOTHER COLD
FRONT WILL MOVE INTO THE AREA THURSDAY AND STALL INTO FRIDAY AS
WEAK WAVES OF LOW PRESSURE MOVE ALONG IT. COOLER HIGH PRESSURE
WILL RETURN NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
02/19Z MESOANALYSIS AND KLTX/KRAX REFLECTIVITY DATA SHOWED THE
BACKDOOR COLD FRONT EXTENDING FROM ROUGHLY CAPE FEAR ARCHING BACK
TO SOUTHERN PINES...LEXINGTON AND WINSTON SALEM. THE FRONT IS
STEADILY DROPPING SOUTH ALONG THE NORTH CAROLINA COAST AIDED BY
POST-FRONTAL ISALLOBARIC RISES OF 3-4MB/3HRS. A VERY WARM AND
SOMEWHAT HUMID AIRMASS IS IN PLACE ACROSS COASTAL SOUTH CAROLINA
AND GEORGIA AHEAD OF THE FRONT WITH TEMPERATURES SOARING WELL INTO
THE 80S TO NEAR 90 DEGREES. CURRENT AWIPS TIMING TOOLS AND RUC
DATA SUPPORT THE FRONT REACHING THE CHARLESTON METRO AREA BY VERY
LATE AFTERNOON AND THE SAVANNAH AREA BY MID-EVENING. THE PRIMARY
CONCERNS THIS EVENING IS THE POTENTIAL FOR ISOLATED SEVERE TSTMS.
THE AIRMASS ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA
IS SLOWLY DESTABILIZING DESPITE STIFF DOWNSLOPE FLOW CONDITIONS.
EARLIER CAPPING NOTED ON RUC SOUNDINGS IS QUICKLY ERODING AS
TEMPERATURES REACH NEAR 90 DEGREES. SBCAPE IS APPROACHING 1500
J/KG WITH LIFTED INDICES AS LOW AS -5C. VISIBLE SATELLITE IMAGERY
ALREADY SHOW LINES OF CUMULUS BEGINNING TO BUILD ALONG VARIOUS
MESOSCALE BOUNDARIES SUCH AS THE MATURING LAKE BREEZE CIRCULATIONS
AROUND THE PERIPHERY OF LAKES MOULTRIE AND MARION AS WELL AS
DIFFERENTIAL HEATING BOUNDARIES CREATED FROM EARLIER CLOUD COVER
NORTH OF THE SOUTH SANTEE RIVER. THE VARIOUS HIGH RESOLUTION MODEL
PACKAGES REMAIN SIMILAR IN THE DEPICTION OF ISOLATED SHOWERS/TSTMS
INITIATING ALONG AND AHEAD OF THE SOUTHWARD MOVING BACKDOOR FRONT
OVER THE NEXT FEW HOURS AS WEAK H7-H5 PERTURBATIONS CROSS THE REGION
WHILE SLIDING DOWN THE EASTERN AXIS OF THE UPPER RIDGE. WILL
MAINTAIN SLIGHT CHANCE POPS FOR ALL ZONES THROUGH THE EVENING WITH
THE HIGHEST GRIDDED POPS WORKING SLOWLY NORTH-SOUTH WITH THE FRONT.
LOCALIZED HIGHER POPS MAY BE NEEDED LATER THIS AFTERNOON OR EVENING
ONCE CONVECTIVE TRENDS ARE ESTABLISHED.
DCAPES NEAR 1200 J/KG AND WBZ HEIGHTS NEAR 10 KFT WILL SUPPORT A
RISK FOR DAMAGING WINDS AND MARGINALLY SEVERE HAIL...BUT THE LACK
OF DEEP LAYERED SHEAR SUGGESTS ANY SUCH ACTIVITY WILL REMAIN
LOOSELY ORGANIZED AT BEST. WILL CONTINUE HIGHLIGHT ISOLATED SEVERE
TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. ANY RISK FOR SEVERE TSTMS
SHOULD DIMINISH BY LATE EVENING AS INSTABILITY WANES AND UPPER
RIDGE BUILDS EAST.
CLOUD COVER WILL BE HEAVILY INFLUENCES BY THE AMOUNT OF CONVECTION
THAT FIRES. ALTHOUGH THERE WILL BE PERIODS OF MOSTLY CLOUDY SKIES
THIS EVENING WITH TSTMS...EXPECT PARTLY CLOUDY SKIES TO DOMINATE
OVERALL. LOWS WILL RANGE FROM THE LOWER 60S NORTH TO MID 60S
SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
A RATHER CONVOLUTED PATTERN WILL CONTINUE FOR THE FORESEEABLE
FUTURE. THE UPPER RIDGE WILL BREAK DOWN ON TUESDAY ALLOWING
NUMEROUS SHORTWAVES TO MOVE THROUGH THE SOUTHEAST UNITED STATES
THROUGH THURSDAY. A STALLED FRONT DRAPED ACROSS THE AREA ON
TUESDAY WILL CREATE A SUBSTANTIAL TEMPERATURE GRADIENT. INTERIOR
SOUTHEAST GA WILL RISE INTO THE LOWER-MID 80S WHILE THE TRI-COUNTY
REGION IN SC WILL STAY IN THE UPPER 70S. ISOLATED TO SCATTERED
SHOWERS/STORMS ARE EXPECTED BUT COVERAGE SHOULD BE SOMEWHAT
LIMITED BY THE MID-LEVEL CAPPING.
THE FRONT WILL ERODE TUESDAY NIGHT BUT ANOTHER BACKDOOR FRONT WILL
BE KNOCKING ON THE NORTHERN DOOR ON WEDNESDAY. DEEP WEST-SOUTHWEST
FLOW AND SOME PRE-FRONTAL COMPRESSION WILL PUSH HIGH TEMPS WELL INTO
THE 80S. ISOLATED/SCATTERED CONVECTION IS EXPECTED BUT THE WESTERLY
SUBSIDENT FLOW SHOULD LIMIT COVERAGE YET AGAIN.
THE FRONT WILL MOVE INTO THE AREA ON THURSDAY AND SEVERAL RIPPLES OF
LOW PRESSURE WILL MOVE ALONG IT. A MORE FAVORABLE MID-LEVEL
ENVIRONMENT AND LOW-LEVEL INSTABILITY WILL SUPPORT BETTER COVERAGE
OF SHOWERS AND THUNDERSTORMS. THE COOLER AIRMASS COUPLED WITH
EXTENSIVE CLOUD COVER WILL KEEP TEMPS CLOSER TO 80 DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AT LEAST ONE AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA ALONG
THE LINGERING SURFACE FRONT...FINALLY PUSHING OFFSHORE FRIDAY NIGHT
IN ACCORDANCE WITH THE ATTENDANT UPPER TROUGH OF LOW PRESSURE. HIGH
PRESSURE WILL THEN BUILD FROM THE NORTH BRINGING A MUCH MORE
SEASONAL AIR MASS TO AREA FOR THE WEEKEND WITH A SLIGHT MODERATION
EARLY NEXT WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR FOR THE NEXT 24 HOURS. BACKDOOR COLD FRONT IS MOVING STEADILY
SOUTH OUT OF NORTH CAROLINA AND WILL APPROACH KCHS BY LATE
AFTERNOON...POSSIBLY ACCOMPANIED BY ISOLATED TSTMS. GIVEN THE
LIMITED SPATIAL COVERAGE THAT IS EXPECTED...NO MENTION WILL BE
INCLUDED IN THE KCHS TAF. CB/S WILL BE CONTINUED. TSTMS SHOULD BE
SOUTH OF THE TERMINAL BY 00Z WITH LINGERING CLOUD COVER. FALLING
DEWPOINTS IN THE WAKE OF THE FRONT WILL PREVENT FOG FROM BECOMING
AN ISSUE OVERNIGHT.
THE FRONT WILL APPROACH THE KSAV TERMINAL BY MID-EVENING. STILL
COULD SEE ISOLATED TSTMS WITH THE FRONT...BUT GUIDANCE SUGGESTS
ANY FRONTAL ACTIVITY WILL REMAIN NORTH. TRENDS WILL BE MONITORED
HOWEVER...BUT NO MENTION OF TSTMS WILL BE INCLUDED GIVEN THE
LIMITED SPATIAL COVERAGE. THICKER CLOUD COVER WILL LINGER AT KSAV
OVERNIGHT...BUT CIGS WILL REMAIN VFR. LOOKS LIKE THERE WILL BE
ENOUGH WIND TO PRECLUDE SIGNIFICANT FOG DEVELOPMENT.
EXTENDED AVIATION OUTLOOK...OCCASIONAL REDUCED CIG/VSBY IN SCATTERED
SHRA/TSRA TUESDAY THROUGH FRIDAY NIGHT. MVFR/IFR CIGS/VSBYS POSSIBLE
DURING THE NIGHTTIME PERIODS IN LOW CEILINGS AND/OR FOG.
&&
.MARINE...
WINDS WILL TURN EAST/NORTHEAST BEHIND THE SOUTHWARD MOVING FRONT
THIS EVENING. THE HIGHEST WINDS LOOK TO OCCUR ACROSS THE SOUTH
CAROLINA WATERS WHERE A SURGE AS HIGH AS 15-20 KT CAN BE EXPECTED.
WINDS WILL BE SLIGHTLY LESS ACROSS THE GEORGIA WATERS. SEAS WILL
BUILD SLIGHTLY WITH THE FAVORABLE NORTHEAST FETCH...BUILDING TO
3-4 FT ALONG THE CHARLESTON COUNTY COASTAL WATERS WITH 2-3 FT
ELSEWHERE.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL STALL OVER THE WATERS
TUESDAY WHILE DISSIPATING. ANOTHER COLD FRONT WILL APPROACH FROM THE
NORTH WEDNESDAY/WEDNESDAY NIGHT AND PUSH INTO THE WATERS THURSDAY.
THE FRONT WILL THEN STALL INTO FRIDAY WHILE AT LEAST ONE AREA OF LOW
PRESSURE MOVES EAST ALONG IT...FINALLY PUSHING OFFSHORE FRIDAY
NIGHT. HIGH PRESSURE WILL THEN BUILD FROM THE NORTH SATURDAY.
CONDITIONS SHOULD REMAIN BELOW ADVISORY LEVELS THROUGH THE PERIOD
UNTIL SATURDAY WHEN INCREASING NE WINDS PUSH SEAS TO AT LEAST 6 FT.
&&
.CLIMATE...
AS OF 3 PM...THE RECORD AT THE CHARLESTON AIRPORT HAS BEEN TIED AT
90 DEGREES. THERE IS A CHANCE FOR EVEN WARMER CONDITIONS PRIOR TO
SUNSET.
RECORD HIGHS FOR TODAY...APRIL 2ND...
CHARLESTON AIRPORT..... 90 SET IN 2006
DOWNTOWN CHARLESTON.... 89 SET IN 1910
SAVANNAH AIRPORT....... 91 SET IN 1940
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE... /JRL
CLIMATE...
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
142 PM EDT MON APR 2 2012
.UPDATE...
/ISSUED AT 1146 AM EDT MON APR 2 2012/
HAVE UPDATED THE FORECAST THROUGHOUT THE MORNING TO INCREASE CLOUD
COVERAGE ACROSS THE SOUTHWEST PART OF THE CWA. HAVE ALSO SEEN
DEVELOPMENT ACROSS NORTH GEORGIA. OTHERWISE...ONLY MINOR TWEAKS TO
THE FORECAST.
BOTH HRRR AND LOCAL WRF SUGGEST CONVECTION ALONG THE EASTERN EDGE
OF THE CWA SO CONTINUED CURRENT POP FORECAST WHICH REFLECTS THIS.
ALSO AGREE WITH OVERALL THINKING THAT SOME OF THE STORMS COULD
BECOME STRONG. SPC HAS THE AREA IN A SEE TEXT WITH 5 PERCENT FOR
WIND AND HAIL.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
/ISSUED 435 AM EDT MON APR 2 2012/
RIDGE ALOFT CONTINUES OVER GEORGIA TODAY WITH PERSISTENT ABOVE
AVERAGE TEMPERATURES AND DRY CONDITIONS. A FRONT MOVING SOUTHWARD
THROUGH THE MID ATLANTIC STATES TODAY SHOULD MOVE INTO THE
SAVANNAH RIVER VALLEY BY TONIGHT. SOME UNCERTAINTY BETWEEN THE
MODELS ON HOW FAR WESTWARD THE FRONT WILL PUSH INTO THE CWA.
HOWEVER...EASTERLY WINDS ARE SHOWN FOR AHN OVERNIGHT AND INTO THE
EARLY MORNING OF TUESDAY. SO HAVE INCLUDED A SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EXTREME NORTHEAST CORNER THIS
AFTERNOON...AND A SLIGHT CHANCE TONIGHT ALONG MUCH OF THE EASTERN
SIDE OF THE CWA. MEANWHILE...A SHORT WAVE FROM THE NORTHWEST GULF
MOVES INTO THE LOWER MISSISSIPPI VALLEY TONIGHT AND INTO THE OHIO
VALLEY ON TUESDAY. THIS WILL BRING A CHANCE OF THUNDERSTORMS INTO
THE REMAINDER OF THE CWA TUESDAY AND TUESDAY NIGHT. HAVE TAKEN A
COMPROMISE ON THE MAV/MET TEMPERATURES. WITH THE POSSIBILITY OF A
BACKDOOR FRONT AFFECTING THE EASTERN COUNTIES...HAVE TRENDED
TOWARD THE COOLER TEMPERATURES TUESDAY AND TUESDAY NIGHT IN THAT
AREA.
41
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
/ISSUED 435 AM EDT MON APR 2 2012/
EXTENDED PROGS APPEAR TO BE COMING INTO SOMEWHAT BETTER AGREEMENT
WITH THE UPPER RIDGE BEGINNING TO FLATTEN OUT OVER THE SOUTHEAST
U.S. WEDNESDAY/THURSDAY AS AN UPPER TROUGH/CLOSED LOW COMPLEX MOVES
EAST FROM THE PLAINS. ECMWF CONTINUE TO BE A TAD SLOWER (AND
FARTHER SOUTH) WITH THIS SYSTEM MOVING EASTWARD. BY 12Z FRIDAY GFS
TAKES THE LOW ACROSS TENNESSEE AND INTO THE CAROLINAS BY THE END
OF THE DAY...WHILE THE ECMWF SHOWS THE LOW OVER ALABAMA MOVING
INTO EAST CENTRAL GEORGIA DURING THIS TIME PERIOD. BOTH SHOW THIS
SYSTEM EAST OF OUR AREA BY SATURDAY WITH A HIGH PRESSURE RIDGE
BEGINNING TO BUILD BACK ACROSS THE SOUTHEAST STATES. NONETHELESS
WILL CONTINUE PREVIOUS FORECAST TREND WITH CHANCE TO GOOD CHANCE
POPS MUCH OF THE AREA WEDNESDAY INTO FRIDAY...WITH SLIGHT CHANCE
POPS FRIDAY NIGHT...ENDING ALL PRECIP BY SATURDAY.
49
CLIMATE...
RECORDS FOR 04-02
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 89 1940 46 1915 63 1908 28 1924
KATL 88 1940 42 1915 63 1979 25 1881
1905
KCSG 86 1999 54 1993 67 2000 34 1992
1978 1961
KMCN 88 1940 48 1915 63 2000 32 1992
1935
RECORDS FOR 04-03
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 88 1934 47 1987 62 2007 26 1992
1974
KATL 86 1946 39 1987 65 1974 29 1992
1945
KCSG 88 1999 52 1987 70 1977 32 1962
1957
KMCN 89 1957 51 1901 69 1977 31 1993
1992
1971
&&
.AVIATION...
18Z UPDATE...
SCT MID LEVEL CU-TCU AND WNW WINDS GUSTING TO AROUND 20KTS WILL
PREVAIL THIS AFTERNOON. MODELS AGREE ON A BACKDOOR FRONT SAGGING
INTO ATLANTA AREA BY 12-15Z TUE. AS A RESULT...EXPECT SCT025 TO
ADVECT INTO ATL BY 12Z...THEN GO BKN040 BY 15Z WITH SOME DAYTIME
HEATING AND THE FRONT IN THE AREA. WINDS SWING MORE NW BY 12Z
TUE...THEN OVER NE BY 15Z TUE BEHIND THE BACKDOOR FRONT. THE FRONT
RETREATS BACK NORTH BY 18Z TUE...RESULTING IN WINDS SWINGING BACK NW
BY 18Z. SPEEDS DIMINISHING BY 00Z THIS EVENING TO 5-7KTS AND EXPECT
MAYBE 6-8KTS ON TUE. CURRENT THINKING IS THE TSTM THREAT WILL BE
MAINLY NORTH AND EAST OF ATL ON TUE...BUT WILL MENTION PROB30 19-23Z
AT AHN FOR NOW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF MID LEVEL CIGS AND WINDS SWINGING NE
EARLY TUE MORNING. HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 59 81 58 / 10 20 30 30
ATLANTA 84 65 84 63 / 5 10 20 30
BLAIRSVILLE 82 57 80 54 / 20 20 30 40
CARTERSVILLE 84 61 85 59 / 10 10 20 40
COLUMBUS 86 65 86 62 / 0 10 20 20
GAINESVILLE 85 61 81 60 / 10 20 30 40
MACON 87 62 86 61 / 0 10 20 20
ROME 85 58 86 60 / 10 10 20 40
PEACHTREE CITY 84 61 85 58 / 0 10 20 20
VIDALIA 85 64 84 65 / 10 10 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1146 AM EDT MON APR 2 2012
.UPDATE...
HAVE UPDATED THE FORECAST THROUGHOUT THE MORNING TO INCREASE CLOUD
COVERAGE ACROSS THE SOUTHWEST PART OF THE CWA. HAVE ALSO SEEN
DEVELOPMENT ACROSS NORTH GEORGIA. OTHERWISE...ONLY MINOR TWEAKS TO
THE FORECAST.
BOTH HRRR AND LOCAL WRF SUGGEST CONVECTION ALONG THE EASTERN EDGE
OF THE CWA SO CONTINUED CURRENT POP FORECAST WHICH REFLECTS THIS.
ALSO AGREE WITH OVERALL THINKING THAT SOME OF THE STORMS COULD
BECOME STRONG. SPC HAS THE AREA IN A SEE TEXT WITH 5 PERCENT FOR
WIND AND HAIL.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
/ISSUED 435 AM EDT MON APR 2 2012/
RIDGE ALOFT CONTINUES OVER GEORGIA TODAY WITH PERSISTENT ABOVE
AVERAGE TEMPERATURES AND DRY CONDITIONS. A FRONT MOVING SOUTHWARD
THROUGH THE MID ATLANTIC STATES TODAY SHOULD MOVE INTO THE
SAVANNAH RIVER VALLEY BY TONIGHT. SOME UNCERTAINTY BETWEEN THE
MODELS ON HOW FAR WESTWARD THE FRONT WILL PUSH INTO THE CWA.
HOWEVER...EASTERLY WINDS ARE SHOWN FOR AHN OVERNIGHT AND INTO THE
EARLY MORNING OF TUESDAY. SO HAVE INCLUDED A SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EXTREME NORTHEAST CORNER THIS
AFTERNOON...AND A SLIGHT CHANCE TONIGHT ALONG MUCH OF THE EASTERN
SIDE OF THE CWA. MEANWHILE...A SHORT WAVE FROM THE NORTHWEST GULF
MOVES INTO THE LOWER MISSISSIPPI VALLEY TONIGHT AND INTO THE OHIO
VALLEY ON TUESDAY. THIS WILL BRING A CHANCE OF THUNDERSTORMS INTO
THE REMAINDER OF THE CWA TUESDAY AND TUESDAY NIGHT. HAVE TAKEN A
COMPROMISE ON THE MAV/MET TEMPERATURES. WITH THE POSSIBILITY OF A
BACKDOOR FRONT AFFECTING THE EASTERN COUNTIES...HAVE TRENDED
TOWARD THE COOLER TEMPERATURES TUESDAY AND TUESDAY NIGHT IN THAT
AREA.
41
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
/ISSUED 435 AM EDT MON APR 2 2012/
EXTENDED PROGS APPEAR TO BE COMING INTO SOMEWHAT BETTER AGREEMENT
WITH THE UPPER RIDGE BEGINNING TO FLATTEN OUT OVER THE SOUTHEAST
U.S. WEDNESDAY/THURSDAY AS AN UPPER TROUGH/CLOSED LOW COMPLEX MOVES
EAST FROM THE PLAINS. ECMWF CONTINUE TO BE A TAD SLOWER (AND
FARTHER SOUTH) WITH THIS SYSTEM MOVING EASTWARD. BY 12Z FRIDAY GFS
TAKES THE LOW ACROSS TENNESSEE AND INTO THE CAROLINAS BY THE END
OF THE DAY...WHILE THE ECMWF SHOWS THE LOW OVER ALABAMA MOVING
INTO EAST CENTRAL GEORGIA DURING THIS TIME PERIOD. BOTH SHOW THIS
SYSTEM EAST OF OUR AREA BY SATURDAY WITH A HIGH PRESSURE RIDGE
BEGINNING TO BUILD BACK ACROSS THE SOUTHEAST STATES. NONETHELESS
WILL CONTINUE PREVIOUS FORECAST TREND WITH CHANCE TO GOOD CHANCE
POPS MUCH OF THE AREA WEDNESDAY INTO FRIDAY...WITH SLIGHT CHANCE
POPS FRIDAY NIGHT...ENDING ALL PRECIP BY SATURDAY.
49
CLIMATE...
RECORDS FOR 04-02
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 89 1940 46 1915 63 1908 28 1924
KATL 88 1940 42 1915 63 1979 25 1881
1905
KCSG 86 1999 54 1993 67 2000 34 1992
1978 1961
KMCN 88 1940 48 1915 63 2000 32 1992
1935
RECORDS FOR 04-03
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 88 1934 47 1987 62 2007 26 1992
1974
KATL 86 1946 39 1987 65 1974 29 1992
1945
KCSG 88 1999 52 1987 70 1977 32 1962
1957
KMCN 89 1957 51 1901 69 1977 31 1993
1992
1971
AVIATION...
12Z UPDATE...
/ISSUED 740 AM EDT MON APR 2 2012/
AREA OF IFR STRATUS CONTINUES TO EXPAND NORTH AND EAST INTO AL AND
GA. LOOKS LIKE CLOUDS MAY HOLD TOGETHER TO REACH ATL AROUND 13Z AND
THEN GRADUALLY LIFT INTO MVFR WITH HEATING. EXPECTING VFR BY AROUND
17Z. CEILINGS MAY NOT MAKE IT INTO MCN AND AHN AS IFR BUT MAY LIFT
INTO MVFR. SOUTHWEST WINDS INCREASING TO 10 TO 15KT BY 15Z WITH SOME
GUSTS TO NEAR 20KT AFTER 17Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON STRATUS. HIGH CONFIDENCE ON AL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 59 81 58 / 10 20 30 30
ATLANTA 84 65 84 63 / 5 10 20 30
BLAIRSVILLE 82 57 80 54 / 20 20 30 40
CARTERSVILLE 84 61 85 59 / 10 10 20 40
COLUMBUS 86 65 86 62 / 0 10 20 20
GAINESVILLE 85 61 81 60 / 10 20 30 40
MACON 87 62 86 61 / 0 10 20 20
ROME 85 58 86 60 / 10 10 20 40
PEACHTREE CITY 84 61 85 58 / 0 10 20 20
VIDALIA 85 64 84 65 / 10 10 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
326 PM EDT MON APR 2 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
CHANCES OF MORE THUNDERSTORMS LATE TONIGHT THROUGH TUESDAY EVENING
AND WARMER TEMPERATURES FOR TUESDAY WILL BE THE MAIN SHORT TERM
CONCERNS.
FOR TONIGHT...MOSTLY CLEAR SKIES EXPECTED ACROSS MUCH OF THE AREA
THIS EVENING WITH SOME INCREASING IN MID LEVEL CLOUDINESS WITH MID
LEVEL FRONTAL ZONE EXTENDING FROM NORTHERN LOWER MICHIGAN INTO
NORTHWEST OHIO. SOME LOWER BASED CLOUDS HAVE ALSO BEEN DEVELOPING
ALONG A LINE FROM NORTHWEST ILLINOIS INTO WEST CENTRAL ILLINOIS
WHICH SEEM TO CORRELATE WELL WITH RUC 900/850 HPA LAYER
FRONTOGENESIS FIELDS THIS AFTERNOON. THIS AXIS WILL GRADUALLY SHIFT
EASTWARD LATER THIS EVENING WITH INCREASE IN CLOUDINESS LATER THIS
EVENING FROM WEST TO EAST. WATER VAPOR IMAGERY NOT DEPICTING ANY
IMMEDIATE SHORT WAVES OF CONSEQUENCE FOR THE LOCAL AREA TONIGHT BUT
CONSISTENT SIGNAL OVER THE PAST FEW DAYS HAS BEEN FOR DEVELOPMENT OF
30 KNOT SOUTHWESTERLY LOW LEVEL JET NOSING INTO FAR NORTH CENTRAL
INDIANA/SOUTHERN LOWER MICHIGAN...PERHAPS A BIT MORE DELAYED IN THE
LAST FEW MODEL CYCLES. SEE LITTLE TO DEVIATE FROM PREVIOUS FORECAST
FOR TONIGHT AT THIS POINT WITH MID CHANCE POPS NORTH AND LOW CHANCE
POPS SOUTH...WITH THE HIGHER TSRA POPS LINING UP BETTER WITH 850 HPA
MOISTURE CONVERGENCE ACROSS SOUTHERN LOWER MICHIGAN AND FAR NORTHERN
INDIANA AFTER 06Z AS STRONG LOW LEVEL THETAE ADVECTION SPREADS FROM
WEST TO EAST.
ELEVATED MIXED LAYER ADVECTING INTO THE AREA LATER TONIGHT DOES POSE
SOME UNCERTAINTY WITH MAGNITUDE OF ELEVATED INSTABILITY. TAKING A
900 HPA BASED PARCEL FROM 12Z NAM BUFFER SOUNDINGS YIELDS BETWEEN
1000-1500 J/KG OF ELEVATED CAPE AFTER 06Z. 12Z GFS BUFFER SOUNDINGS
REMAIN A BIT MORE PRONOUNCED WITH THIS ELEVATED MIXED LAYER AND MID
LEVEL WARM LAYER THAT WOULD RESULT IN LESSER INSTABILITY THAN
INDICATED BY THE NAM. EFFECTIVE SHEAR FOR THESE ELEVATED PARCELS
SHOULD DECREASE STEADILY OVERNIGHT HOWEVER WHICH SHOULD TEND TO
LIMIT POTENTIAL FOR CONVECTIVE ORGANIZATION/SEVERE THREAT. PREVIOUS
FORECAST IDEA OF ISOLATED LARGE HAIL THREAT STILL SEEMS IN
ORDER...BUT SHIFTED A BIT LATER AFTER 06Z BASED ON TREND OF SLIGHTLY
SLOWER MODEL DEPICTION OF LOW LEVEL JET AXIS SHIFTING INTO THE AREA.
LINGERING ELEVATED CONVECTION SHOULD DIMINISH EARLY TUESDAY AS LOW
LEVEL JET VEERS AND MOISTURE CONVERGENCE WEAKENS. A CONVECTIVELY
ENHANCED VORT MAX ACROSS EASTERN TEXAS THIS AFTERNOON SHOULD LIFT
NORTHWARD INTO MID MS RVR VALLEY LATE TUESDAY AFTERNOON...BUT
OVERALL CONVECTIVE THREAT APPEARS TO BE LOW FOR LATE
MORNING/AFTERNOON HOURS WITH FCST SOUNDINGS SUGGEST SOME CAPPING
CONCERNS. THUS...HAVE LOWERED AFTERNOON TSRA POPS AND MAINTAINED
HIGHEST CHANCE ACROSS THE WEST WHERE FORCING FROM THIS VORT MAX WILL
LIKELY BE MAXIMIZED. BEST CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS
TO BE FOR THE EVENING HOURS AS ANOTHER SOUTHERN CANADIAN UPPER LEVEL
SHORT WAVE PROVIDES IMPETUS FOR SFC LOW/FRONT TO SHIFT SOUTHEAST
THROUGH THE AREA. LOW LEVEL FRONTOGENESIS ALSO TO STRENGTHEN AS
STRONGER NORTHERLY FLOW INTERACTS WITH THIS BOUNDARY DURING THE
EARLY EVENING. SEVERE POTENTIAL APPEARS TO BE RELATIVELY LOW AT THIS
TIME DUE TO CONTINUED MARGINAL TO WEAK SHEAR PROFILES. HAVE ALSO
INCREASED MAX TEMPS FOR TUESDAY WITH CONFIDENCE INCREASING THAT MOST
IF NOT ALL OF FORECAST AREA WILL GET INTO WARM SECTOR AGAIN BEFORE
FRONTAL PASSAGE IN THE FAR NORTHWEST MID TO LATE AFTERNOON. RECORD
HIGHS IN THE UPPER 70S FOR FORT WAYNE AND SOUTH BEND COULD ONCE
AGAIN BE AT RISK OF BEING BROKEN.
&&
.LONG TERM...
WEDNESDAY THROUGH MONDAY
MAIN FOCUS OF LONG TERM PERIOD IS COOLER TEMPERATURES AND FROST
POTENTIAL WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
LONG TERM PERIOD BEGINS WEDNESDAY WITH SURFACE HIGH PRESSURE
CENTERED NORTHWEST OF THE REGION BUILDING SOUTHEASTWARD INTO THE
LOWER GREAT LAKES...AND A FRONTAL BOUNDARY SITUATED ALONG THE OHIO
RIVER VALLEY. CUTOFF UPPER LOW OVER PANHANDLE REGION WILL SLOWLY
TRACK EASTWARD TOWARDS MID MISSISSIPPI VALLEY. DRY CONDITIONS ARE
EXPECTED WEDNESDAY AND WEDNESDAY NIGHT. KEPT PATCHY FROST MENTION IN
THE NE PORTION OF THE FA...BUT INCREASED GRADIENT OF LOW TEMPS FROM
NE TO SW AS CUTOFF LOW AND AFOREMENTIONED BOUNDARY PASS JUST SOUTH
OF THE FA.
CUTOFF LOW WILL CONTINUE EASTWARD INTO LOWER OHIO VALLEY ON
THURSDAY. 12Z GFS INDICATED PRECIP POTENTIAL ACROSS THE FAR SW
PORTIONS OF THE FA AS FRONTAL BOUNDARY SLIDES EASTWARD.
HOWEVER...CONFIDENCE IS LOW AS 12Z GFS RUN OPENS LOW INTO POSITIVELY
TILTED WAVE QUICKER AND DIVES MORE SOUTHEASTERLY THAN PREVIOUS
RUN...MORE IN LINE WITH 00Z ECMWF. THURSDAY NIGHT LOOKS TO BE THE
COOLEST NIGHT IN THE EXTENDED PERIOD AS SFC RIDGE AXIS SLIDES
OVERHEAD. KEPT THE AREAS OF FROST MENTION IN ROUGHLY THE SAME AREAS
AS PREVIOUS FCST. WILL CONTINUE TO MONITOR THIS PD OVER THE NEXT FEW
FORECASTS WITH POSSIBLE NEED FOR HEADLINES...WITH LOWS NEARING 32-33
ACROSS MUCH OF THE FA.
SFC RIDGE WILL CONTINUE TO SLIDE EAST ACROSS GREAT LAKES AS UPPER
RIDGE AXIS MOVES ACROSS THE REGION. FRIDAY WILL AGAIN BE COOLER WITH
EASTERLY WINDS AND SLOWLY MODERATING AIRMASS. KEPT PATCHY FROST
MENTION IN FCST FRI NIGHT AS RIDGE AXIS WILL BE JUST EAST OF FA AND
LIGHTER WINDS. SATURDAY WILL BE CONSIDERABLY WARM WITH UPPER RIDGE
OVER THE AREA AND SFC HIGH EAST...RESULTING IN SOUTHERLY WINDS AND
WAA. RAISED TEMPS A FEW DEGREES FROM PREVIOUS FCST/ALLBLEND.
NEXT PRECIP CHANCES RETURN SAT NIGHT/SUN AS DEEPENING SFC
LOW/EJECTING WRN CONUS TROF ENERGY ACROSS NRN TIER BRINGS A COLD
FRONT THROUGH THE REGION. KEPT POPS CHANCE/SLIGHT CHANCE AS BEST
FORCING REMAINS NORTH AND BEST MOISTURE/INSTABILITY REMAINS SOUTH.
&&
.AVIATION...
18Z TAFS...MAIN AVIATION FORECAST CONCERN WILL BE POTENTIAL OF
THUNDERSTORMS LATE TONIGHT INTO TUESDAY. IN THE MEANTIME...QUIET
AVIATION CONDITIONS IN STORE WITH EASTERLY WINDS CONTINUING TO THE
NORTH OF THE SFC BOUNDARY WHICH TRACKED ACROSS THE AREA YESTERDAY.
MIXING HEIGHTS NOT PARTICULARLY DEEP...BUT GUSTS TO AROUND 20
KNOTS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON. FOR TONIGHT...A LOW LEVEL JET ACROSS THE MID MS VALLEY
IS EXPECTED TO SHIFT INTO THE SOUTHERN GREAT LAKES REGION
RESULTING IN STRENGTHENING WARM AIR ADVECTION. THIS FORCING MAY BE
ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT
OVERNIGHT...ESPECIALLY AFTER 06Z. CONFIDENCE IS LOW IN THIS
SCENARIO ESPECIALLY AT KFWA WHICH MAY END UP JUST SOUTH OF THIS
LOW LEVEL JET AXIS. DID ADD VCTS MENTION AT KSBN DURING THIS TIME
PERIOD WITH THE EXPECTATION OF AT LEAST SCATTERED CONVECTION IN
THE AREA...BUT LOW ENOUGH CONFIDENCE AT THIS POINT TO NOT INCLUDE
TS IN THE FORECAST FOR TERMINAL. LULL IN PRECIP IS POSSIBLE
TUESDAY LATE MORNING INTO AFTERNOON WITH LITTLE FORCING TO FOCUS
ADDITIONAL STORMS AND HAVE KEPT FORECAST DRY THROUGH END OF THE
PERIOD. SFC WINDS TO VEER MORE SOUTHERLY AFTER 14Z AS SFC LOW
PRESSURE TRACKS INTO EASTERN IOWA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MARSILI
LONG TERM...NG
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 PM EDT MON APR 2 2012
.AVIATION...
18Z TAFS...MAIN AVIATION FORECAST CONCERN WILL BE POTENTIAL OF
THUNDERSTORMS LATE TONIGHT INTO TUESDAY. IN THE MEANTIME...QUIET
AVIATION CONDITIONS IN STORE WITH EASTERLY WINDS CONTINUING TO THE
NORTH OF THE SFC BOUNDARY WHICH TRACKED ACROSS THE AREA YESTERDAY.
MIXING HEIGHTS NOT PARTICULARLY DEEP...BUT GUSTS TO AROUND 20
KNOTS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON. FOR TONIGHT...A LOW LEVEL JET ACROSS THE MID MS VALLEY
IS EXPECTED TO SHIFT INTO THE SOUTHERN GREAT LAKES REGION
RESULTING IN STRENGTHENING WARM AIR ADVECTION. THIS FORCING MAY BE
ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT
OVERNIGHT...ESPECIALLY AFTER 06Z. CONFIDENCE IS LOW IN THIS
SCENARIO ESPECIALLY AT KFWA WHICH MAY END UP JUST SOUTH OF THIS
LOW LEVEL JET AXIS. DID ADD VCTS MENTION AT KSBN DURING THIS TIME
PERIOD WITH THE EXPECTATION OF AT LEAST SCATTERED CONVECTION IN
THE AREA...BUT LOW ENOUGH CONFIDENCE AT THIS POINT TO NOT INCLUDE
TS IN THE FORECAST FOR TERMINAL. LULL IN PRECIP IS POSSIBLE
TUESDAY LATE MORNING INTO AFTERNOON WITH LITTLE FORCING TO FOCUS
ADDITIONAL STORMS AND HAVE KEPT FORECAST DRY THROUGH END OF THE
PERIOD. SFC WINDS TO VEER MORE SOUTHERLY AFTER 14Z AS SFC LOW
PRESSURE TRACKS INTO EASTERN IOWA.
&&
.PREV DISCUSSION... /ISSUED 1129 AM EDT MON APR 2 2012/
UPDATE...
QUIET WEATHER FOR THIS AFTERNOON WITH MAIN FOCUS CONTINUING ON
TEMPERATURE TRENDS. TEMPERATURES HAVE BEEN VERY SLOW TO RISE THIS
MORNING DUE IN LARGE PART TO A VERY STRONG MORNING INVERSION NOTED
PER AMDAR SOUNDINGS WHICH WERE ONLY MIXED TO BETWEEN 1500-2000 FT
LATE THIS MORNING. SOME SUBTLE DIFFERENCES NOTED IN MIXED LAYER
DEPTHS BETWEEN NAM/RUC FOR THIS AFTERNOON WITH NAM SUGGESTING A
SLIGHTLY DEEPER MIXED LAYER THAT WOULD ALLOW FOR AFTERNOON HIGHS
CLOSE TO THOSE CURRENTLY FORECASTED. THESE HIGHS MAY REPRESENT A
BEST CASE SCENARIO IN TERMS OF MAX HEATING POTENTIAL
TODAY...ESPECIALLY IF MIXING HEIGHTS ARE A BIT MORE SHALLOW LIKE
THE RUC WOULD SUGGEST. WILL HOLD OFF ON ANY ADJUSTMENTS TO MAX
TEMPS AT THIS TIME AND JUST REFINE DIURNAL CURVE TO PUT MOST OF
TEMPERATURE INCREASE IN THE 17Z TO 20Z PERIOD DUE TO EFFECTS FROM
THE INVERSION. MORE SOLID STRATOCU DECK ACROSS NORTHWEST OHIO
SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON AND NOT PLAY A
MAJOR ROLE IN LIMITING AFTERNOON TEMP RISES. UPDATED FORECAST SENT
EARLIER THIS MORNING MAINLY TO REFINE SKY COVER TRENDS.
&&
PREV DISCUSSION... /ISSUED 702 AM EDT MON APR 2 2012/
AVIATION.../12Z TAFS/
PATCHY STRATO CU WITH MVFR CIGS OVER NRN INDIANA EARLY THIS
MORNING... AND A LITTLE MORE WIDESPREAD UPSTREAM OVER NRN OH.
EXPECT WITH DIURNAL HEATING/MIXING THESE CLOUDS WILL DIMINISH
AFTER SUNRISE WITH JUST PATCHY ALTO CU OR CIRRUS THIS AFTN/EVE.
WK LOW WILL MOVE TOWARD THE AREA TONIGHT WITH LLJ TRANSPORTING
INCRSG MOISTURE AND RESULTANT ELEVATED INSTABILITY INTO THE AREA
LATE TONIGHT PSBLY LEADING TO SCT TS...THUS ADDED CB WITH LOW VFR
CIGS AT BOTH TERMINALS TOWARD THE END OF THE PERIOD. GRADIENT
BETWEEN SFC RIDGE MOVG TO LWR GRTLKS AND SF LOW/WARM FRONT MOVG
INTO THE MS VALLEY WILL RESULT IN FAIRLY STRONG ESE SFC WINDS AT
THE TERMINALS TODAY WITH GUSTS AROUND 22KT.
PREV DISCUSSION... /ISSUED 457 AM EDT MON APR 2 2012/
SHORT TERM.../TODAY-TUE NGT/
SHRTWV DROPPING SSE INTO MID ATLANTIC THIS MORNING HAS PUSHED A
BACKDOOR CDFNT THROUGH OUR AREA TO THE LOWER OH VALLEY. MID LEVEL
CONVERGENT FLOW WAS RESULTING IN A COUPLE OF BANDS OF SCT HIGH BASED
SHOWERS BEHIND THE FRONT... ONE OVER SWRN MI AND ANOTHER OVER ERN
INDIANA/SWRN OH. RIDGE ALOFT BUILDING EASTWARD THIS MORNING SHOULD
DIMINISH THIS ACTIVITY OVER THE NEXT 3-6HRS SO LEFT OUT OF TODAYS
FCST WITH SHOWERS FCST TO END BY 12Z IN OUR AREA. RIDGE EXTENDING
SOUTH FROM HUDSON BAY TO THE GRTLKS BEHIND THIS CDFNT SHOULD
PROVIDE FAIR WX TODAY. CDFNT TRANSITIONS TO A STNRY FRONT FROM SRN
IL TO LOW PRESSURE CENTERED OVER NEB/KS. THIS LOW ASSOCIATED WITH
CLOSING OFF UPR SYSTEM OVER AZ/NM AND SHOULD GRADUALLY WEAKEN
TODAY. NRN STREAM SHRTWV MOVG EAST ACROSS MT/SASK WILL RESULT IN
EASTWARD MOVEMENT OF THE WKNG SFC LOW THROUGH THE SHORT TERM
PERIOD. THIS WILL RESULT IN A RATHER TIGHT SFC PRESSURE GRADIENT
ACROSS OUR CWA WITH E-SE SFC WINDS OF 10-20MPH. THIS SHOULD
PROVIDE DECENT MIXING AND SUSPECT MODELS ARE A LITTLE TOO SHALLOW
WITH THE BOUNDARY LAYER THIS AFTN...THUS STAYED CLOSE TO PREVIOUS
FCST HIGHS FOR TODAY WHICH WERE GENERALLY AT OR A BIT ABOVE
LATEST MOS.
AS LOW MOVES CONTS SLOWLY EAST ACROSS IA TONIGHT STNRY FRONT WILL
LIFT SLOWLY NE INTO IL AS A WARM FRONT. H85 THETA-E ADVECTION NE
OF THE SFC WARM FRONT SPREADING INTO OUR AREA ALONG WITH ELEVATED
INSTABILITY IS EXPECTED TO RESULT IN SCT TSTMS DVLPG OVERNIGHT.
GIVEN EXPECTATION OF INCRSG CLOUDS AND SOME GRADIENT WINDS TONIGHT
LEANED TOWARD WARMER END OF GUIDANCE FOR LOWS WHICH ARE FCST TO
RANGE FROM THE U30S NE TO THE L50S SW.
WK LOW IS FCST SIMILARLY BY 00Z MODELS TO TRACK EASTWARD ACROSS OUR
CWA ON TUESDAY. THIS IS SLOWER THAN INDICATED BY EARLIER
NAM/GFS/SREF RUNS... ALLOWING WARMER/MORE MOIST AIRMASS TO SPREAD
INTO THE AREA DURING THE DAY TUE. DESTABILIZATION IS LIKELY WITH
CAPE EXPECTED TO INCREASE INTO THE 1500-2500J/KG RANGE. MOIST
CONVERGENCE ALONG THE WARM/CDFNT ASSOCIATED WITH THE LOW MOVG
THROUGH OUR AREA MAY PROVIDE SUFFICIENT FORCING FOR SCT TSTM
DEVELOPMENT. HWVR... WARM MID LEVEL TEMPS WILL RESULT IN A
CAPPING INVERSION WHICH MAY NOT BREAK UNTIL LATE AFTN OR EVE.
0-6KM SHEAR FCST TO BE WK DURING THIS PERIOD, BUT GIVEN POTENTIAL
DVLPG INSTABILITY, ISOLATED SVR STORMS ARE PSBL. WITH THE SLOWING
TREND OF MODELS TO MOVE LOW/CDFNT THROUGH THE AREA... 00Z RUNS
SUGGESTING HIGH TEMPS COULD BE 5-10F WARMER THAN OUR PREVIOUS
FCST... FOR NOW UTILIZED A BLEND OF 00Z MODEL CONSENSUS AND
PREVIOUS FCST TO TREND HIGHS UP ABOUT 3F. THE MODELS SLOWER TREND
ON MOVING LOW THROUGH THE AREA MAY ALSO IMPACT LOWS TUE NIGHT WITH
COLDER AIR PRBLY SLOWER TO ARRIVE IN OUR AREA. AGAIN JUST TRENDED
UP A FEW DEGREES ATTM.
&&
LONG TERM...
WEDNESDAY THROUGH SUNDAY...THE MAIN CHALLENGES THIS PERIOD INCLUDE
THE CHANCES FOR FROST WEDNESDAY NIGHT THROUGH FRIDAY NIGHT AND THE
POSSIBILITY OF THUNDER OVER THE WEEKEND. FOR THIS PACKAGE...FAVORED
THE ECMWF AND CANADIAN GEM ENSEMBLES. AN UPPER LOW EMBEDDED IN A
RIDGE WILL DRIFT EAST AND WILL PASS SOUTH OF THE FORECAST AREA. KEPT
CONDITIONS DRY THROUGH SATURDAY. HAVE TRENDED TEMPERATURES DOWN MOST
PERIODS THROUGH FRIDAY NIGHT AS A CHILLY NORTH EAST TO EAST FETCH
PERSISTS OVER EASTERN CANADA INTO THE WESTERN GREAT LAKES REGION.
HAVE ADJUSTED THE TIMING OF FROST IN THE GRIDS AND HAZARDOUS WEATHER
OUTLOOK TO MATCH THIS SCENARIO...WITH THE BEST CHANCE FOR FROST
THURSDAY NIGHT. GUT FEELING IS HIGHS FRIDAY ARE STILL TOO WARM...AND
MAY NEED TO BE LOWERED 3 TO 6 MORE DEGREES. THE GFS MEX MOS HIGH OF
63F AT FT WAYNE DEFINITELY LOOKS TOO WARM. CORRESPONDINGLY...GFS MEX
DIURNAL SPREADS OF 30 AND 33 RESPECTIVELY FOR FRIDAY AND SATURDAY
ALSO LOOK TOO LARGE. THE CANADIAN GEM ENSEMBLES EPS GRAMS LOOK GOOD
WITH A TIGHT CLUSTER OF MEMBERS WITH LOWS JUST ABOVE FREEZING
THURSDAY NIGHT AND HIGHS FRIDAY AOB 53 AT FT WAYNE. OTHERWISE...KEPT
A CHANCE FOR THUNDER SATURDAY NIGHT INTO SUNDAY. MOISTURE IS LIMITED
AND FORCING APPEARS MARGINAL AS THE SURFACE LOW TRACKS FROM THE
UPPER MIDWEST INTO SOUTHERN CANADA DURING THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...MARSILI
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1129 AM EDT MON APR 2 2012
.UPDATE...
QUIET WEATHER FOR THIS AFTERNOON WITH MAIN FOCUS CONTINUING ON
TEMPERATURE TRENDS. TEMPERATURES HAVE BEEN VERY SLOW TO RISE THIS
MORNING DUE IN LARGE PART TO A VERY STRONG MORNING INVERSION NOTED
PER AMDAR SOUNDINGS WHICH WERE ONLY MIXED TO BETWEEN 1500-2000 FT
LATE THIS MORNING. SOME SUBTLE DIFFERENCES NOTED IN MIXED LAYER
DEPTHS BETWEEN NAM/RUC FOR THIS AFTERNOON WITH NAM SUGGESTING A
SLIGHTLY DEEPER MIXED LAYER THAT WOULD ALLOW FOR AFTERNOON HIGHS
CLOSE TO THOSE CURRENTLY FORECASTED. THESE HIGHS MAY REPRESENT A
BEST CASE SCENARIO IN TERMS OF MAX HEATING POTENTIAL
TODAY...ESPECIALLY IF MIXING HEIGHTS ARE A BIT MORE SHALLOW LIKE
THE RUC WOULD SUGGEST. WILL HOLD OFF ON ANY ADJUSTMENTS TO MAX
TEMPS AT THIS TIME AND JUST REFINE DIURNAL CURVE TO PUT MOST OF
TEMPERATURE INCREASE IN THE 17Z TO 20Z PERIOD DUE TO EFFECTS FROM
THE INVERSION. MORE SOLID STRATOCU DECK ACROSS NORTHWEST OHIO
SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON AND NOT PLAY A
MAJOR ROLE IN LIMITING AFTERNOON TEMP RISES. UPDATED FORECAST SENT
EARLIER THIS MORNING MAINLY TO REFINE SKY COVER TRENDS.
&&
.PREV DISCUSSION... /ISSUED 702 AM EDT MON APR 2 2012/
AVIATION.../12Z TAFS/
PATCHY STRATO CU WITH MVFR CIGS OVER NRN INDIANA EARLY THIS
MORNING... AND A LITTLE MORE WIDESPREAD UPSTREAM OVER NRN OH.
EXPECT WITH DIURNAL HEATING/MIXING THESE CLOUDS WILL DIMINISH
AFTER SUNRISE WITH JUST PATCHY ALTO CU OR CIRRUS THIS AFTN/EVE.
WK LOW WILL MOVE TOWARD THE AREA TONIGHT WITH LLJ TRANSPORTING
INCRSG MOISTURE AND RESULTANT ELEVATED INSTABILITY INTO THE AREA
LATE TONIGHT PSBLY LEADING TO SCT TS...THUS ADDED CB WITH LOW VFR
CIGS AT BOTH TERMINALS TOWARD THE END OF THE PERIOD. GRADIENT
BETWEEN SFC RIDGE MOVG TO LWR GRTLKS AND SF LOW/WARM FRONT MOVG
INTO THE MS VALLEY WILL RESULT IN FAIRLY STRONG ESE SFC WINDS AT
THE TERMINALS TODAY WITH GUSTS AROUND 22KT.
PREV DISCUSSION... /ISSUED 457 AM EDT MON APR 2 2012/
SHORT TERM.../TODAY-TUE NGT/
SHRTWV DROPPING SSE INTO MID ATLANTIC THIS MORNING HAS PUSHED A
BACKDOOR CDFNT THROUGH OUR AREA TO THE LOWER OH VALLEY. MID LEVEL
CONVERGENT FLOW WAS RESULTING IN A COUPLE OF BANDS OF SCT HIGH BASED
SHOWERS BEHIND THE FRONT... ONE OVER SWRN MI AND ANOTHER OVER ERN
INDIANA/SWRN OH. RIDGE ALOFT BUILDING EASTWARD THIS MORNING SHOULD
DIMINISH THIS ACTIVITY OVER THE NEXT 3-6HRS SO LEFT OUT OF TODAYS
FCST WITH SHOWERS FCST TO END BY 12Z IN OUR AREA. RIDGE EXTENDING
SOUTH FROM HUDSON BAY TO THE GRTLKS BEHIND THIS CDFNT SHOULD
PROVIDE FAIR WX TODAY. CDFNT TRANSITIONS TO A STNRY FRONT FROM SRN
IL TO LOW PRESSURE CENTERED OVER NEB/KS. THIS LOW ASSOCIATED WITH
CLOSING OFF UPR SYSTEM OVER AZ/NM AND SHOULD GRADUALLY WEAKEN
TODAY. NRN STREAM SHRTWV MOVG EAST ACROSS MT/SASK WILL RESULT IN
EASTWARD MOVEMENT OF THE WKNG SFC LOW THROUGH THE SHORT TERM
PERIOD. THIS WILL RESULT IN A RATHER TIGHT SFC PRESSURE GRADIENT
ACROSS OUR CWA WITH E-SE SFC WINDS OF 10-20MPH. THIS SHOULD
PROVIDE DECENT MIXING AND SUSPECT MODELS ARE A LITTLE TOO SHALLOW
WITH THE BOUNDARY LAYER THIS AFTN...THUS STAYED CLOSE TO PREVIOUS
FCST HIGHS FOR TODAY WHICH WERE GENERALLY AT OR A BIT ABOVE
LATEST MOS.
AS LOW MOVES CONTS SLOWLY EAST ACROSS IA TONIGHT STNRY FRONT WILL
LIFT SLOWLY NE INTO IL AS A WARM FRONT. H85 THETA-E ADVECTION NE
OF THE SFC WARM FRONT SPREADING INTO OUR AREA ALONG WITH ELEVATED
INSTABILITY IS EXPECTED TO RESULT IN SCT TSTMS DVLPG OVERNIGHT.
GIVEN EXPECTATION OF INCRSG CLOUDS AND SOME GRADIENT WINDS TONIGHT
LEANED TOWARD WARMER END OF GUIDANCE FOR LOWS WHICH ARE FCST TO
RANGE FROM THE U30S NE TO THE L50S SW.
WK LOW IS FCST SIMILARLY BY 00Z MODELS TO TRACK EASTWARD ACROSS OUR
CWA ON TUESDAY. THIS IS SLOWER THAN INDICATED BY EARLIER
NAM/GFS/SREF RUNS... ALLOWING WARMER/MORE MOIST AIRMASS TO SPREAD
INTO THE AREA DURING THE DAY TUE. DESTABILIZATION IS LIKELY WITH
CAPE EXPECTED TO INCREASE INTO THE 1500-2500J/KG RANGE. MOIST
CONVERGENCE ALONG THE WARM/CDFNT ASSOCIATED WITH THE LOW MOVG
THROUGH OUR AREA MAY PROVIDE SUFFICIENT FORCING FOR SCT TSTM
DEVELOPMENT. HWVR... WARM MID LEVEL TEMPS WILL RESULT IN A
CAPPING INVERSION WHICH MAY NOT BREAK UNTIL LATE AFTN OR EVE.
0-6KM SHEAR FCST TO BE WK DURING THIS PERIOD, BUT GIVEN POTENTIAL
DVLPG INSTABILITY, ISOLATED SVR STORMS ARE PSBL. WITH THE SLOWING
TREND OF MODELS TO MOVE LOW/CDFNT THROUGH THE AREA... 00Z RUNS
SUGGESTING HIGH TEMPS COULD BE 5-10F WARMER THAN OUR PREVIOUS
FCST... FOR NOW UTILIZED A BLEND OF 00Z MODEL CONSENSUS AND
PREVIOUS FCST TO TREND HIGHS UP ABOUT 3F. THE MODELS SLOWER TREND
ON MOVING LOW THROUGH THE AREA MAY ALSO IMPACT LOWS TUE NIGHT WITH
COLDER AIR PRBLY SLOWER TO ARRIVE IN OUR AREA. AGAIN JUST TRENDED
UP A FEW DEGREES ATTM.
LONG TERM...
WEDNESDAY THROUGH SUNDAY...THE MAIN CHALLENGES THIS PERIOD INCLUDE
THE CHANCES FOR FROST WEDNESDAY NIGHT THROUGH FRIDAY NIGHT AND THE
POSSIBILITY OF THUNDER OVER THE WEEKEND. FOR THIS PACKAGE...FAVORED
THE ECMWF AND CANADIAN GEM ENSEMBLES. AN UPPER LOW EMBEDDED IN A
RIDGE WILL DRIFT EAST AND WILL PASS SOUTH OF THE FORECAST AREA. KEPT
CONDITIONS DRY THROUGH SATURDAY. HAVE TRENDED TEMPERATURES DOWN MOST
PERIODS THROUGH FRIDAY NIGHT AS A CHILLY NORTH EAST TO EAST FETCH
PERSISTS OVER EASTERN CANADA INTO THE WESTERN GREAT LAKES REGION.
HAVE ADJUSTED THE TIMING OF FROST IN THE GRIDS AND HAZARDOUS WEATHER
OUTLOOK TO MATCH THIS SCENARIO...WITH THE BEST CHANCE FOR FROST
THURSDAY NIGHT. GUT FEELING IS HIGHS FRIDAY ARE STILL TOO WARM...AND
MAY NEED TO BE LOWERED 3 TO 6 MORE DEGREES. THE GFS MEX MOS HIGH OF
63F AT FT WAYNE DEFINITELY LOOKS TOO WARM. CORRESPONDINGLY...GFS MEX
DIURNAL SPREADS OF 30 AND 33 RESPECTIVELY FOR FRIDAY AND SATURDAY
ALSO LOOK TOO LARGE. THE CANADIAN GEM ENSEMBLES EPS GRAMS LOOK GOOD
WITH A TIGHT CLUSTER OF MEMBERS WITH LOWS JUST ABOVE FREEZING
THURSDAY NIGHT AND HIGHS FRIDAY AOB 53 AT FT WAYNE. OTHERWISE...KEPT
A CHANCE FOR THUNDER SATURDAY NIGHT INTO SUNDAY. MOISTURE IS LIMITED
AND FORCING APPEARS MARGINAL AS THE SURFACE LOW TRACKS FROM THE
UPPER MIDWEST INTO SOUTHERN CANADA DURING THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1120 PM MDT SUN APR 1 2012
.UPDATE...
ISSUED AT 1051 PM MDT SUN APR 1 2012
ADJUSTED START TIME OF WIND ADVISORY FOR WESTERN PART OF CWA BASED
ON 00Z GUIDANCE. LOOKS LIKE ADVISORY WINDS SHOULD DEVELOP OVER
THESE LOCATIONS AS EARLY AS 09Z...SPREADING EASTWARD THROUGH
12Z. STRONGEST WINDS ALOFT STILL LOOK TO BE IN THE 12-18Z TIME
PERIOD ACROSS THE AREA. 00Z GFS AND MAV GUIDANCE ARE THE MOST
BULLISH ON DAYTIME WINDS WITH SUSTAINED WINDS WITHIN WARNING
CRITERIA. LATEST NAM/SREF/RUC/HRRR ALL MUCH LESS...WITH WINDS
REMAINING WITHIN ADVISORY LEVELS. WITH THIS IN MIND I DECIDED TO
KEEP ADVISORY RATHER THAN UPGRADING AT THIS TIME.
UPDATE ISSUED AT 846 PM MDT SUN APR 1 2012
MADE FURTHER ADJUSTMENTS TO WIND FORECAST IN THE 06-15Z PERIOD
BASED ON LATEST RUC AND NAM TIMING OF FROPA. 00Z NAM STILL
INDICATING HIGH END ADVISORY/NEAR WARNING CRITERIA WINDS EARLY
MONDAY MORNING OVER EASTERN COLORADO. 00Z NAM AND LATEST SREF AND
RUC ARE LESS BULLISH THAN EARLIER ON WARNING CRITERIA. I HAVE
KEPT ADVISORY IN PLACE FOR NOW...AND WILL PROBABLY WAIT FOR 00Z
GFS TO MAKE FINAL DECISION ON FURTHER ADJUSTMENTS OR POSSIBLE
UPGRADES.
UPDATE ISSUED AT 554 PM MDT SUN APR 1 2012
MADE MINOR CHANGES TO WIND FORECAST TO ACCOUNT FOR WINDS
INCREASING QUICKER OVER WESTERN PARTS OF CWA AFTER 09Z TONIGHT AND
TO BUMP UP WIND GUST WORDING. I ALSO ADDED PATCHY BLOWING
DUST TO WEATHER GRIDS. IM CONCERNED WE COULD SEE WARNING CRITERIA
WINDS OVER WESTERN PARTS OF THE CWA MONDAY MORNING...HOWEVER NOT
A LOT OF NEW DATA TO LOOK AT AND MAKE A DECISION YET. WILL
PROBABLY WAIT UNTIL 00Z DATA COMES IN TO FURTHER FINE TUNE WIND
FORECAST. OTHER CHANGE WAS TO ADJUST TIMING OF PRECIP
MONDAY...TO INCLUDE RAIN SHOWERS MONDAY AFTERNOON IN THE SOUTH AND
WEST. 18Z NAM/GFS BOTH INDICATING AXIS OF FRONTOGENISIS MOVING NORTH
AND EAST ALONG WITH DECENT MID LEVEL MOISTURE IN THE 21-00Z
TIME-FRAME...SO EARLIER ARRIVAL OF RAIN CANT BE RULED OUT.
RED FLAG CONDITIONS CONTINUE OVER MANY LOCATIONS ACROSS THE
AREA...SO I PLAN ON LETTING THE RFW EXPIRE ON TIME AT 02Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
SOUTHWEST FLOW WILL BE OVER THE REGION TONIGHT. THE UPPER LOW WILL
MOVE INTO SOUTHWEST NEW MEXICO MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO TONIGHT. A COLD FRONT WILL PUSH SOUTH ACROSS
NORTHWEST KANSAS EARLY MONDAY.
SUBSIDENCE WILL CONTINUE OVER THE FA TONIGHT SO POPS WILL BE NIL.
SOME LIGHT PRECIPITATION WILL BE POSSIBLE MONDAY MORNING OVER
WESTERN PORTIONS OF EASTERN COLORADO WHILE DYNAMICS FROM THE UPPER
LOW ARE STILL REASONABLY CLOSE. BY MONDAY AFTERNOON THE LOW WILL
MOVE FAR ENOUGH SOUTH SO THAT CHANCES ARE MUCH LOWER. PLAN TO
CONTINUE SLIGHT CHANCE POPS IN EASTERN COLORADO MONDAY MORNING AND
THEN SILENT POPS MONDAY AFTERNOON. THE REST OF THE FA WILL HAVE NIL
POPS.
STRONG WINDS ARE THE MAIN FOCUS OF THE FORECAST FOR MONDAY. THE
GFS/NAM BOTH INDICATE GUSTS TO AROUND 50 MPH BETWEEN 12-15Z.
SUSTAINED WIND WILL BE STRONG ENOUGH TO SUPPORT A WIND ADVISORY ALL
DAY. SEE DETAILS ON THE WIND ADVISORY BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
MONDAY NIGHT WINDS WILL REMAIN GUSTY THROUGH THE NIGHT...WITH THE
STRONGEST GUSTS DURING THE EVENING...AS THE COOLER TEMPERATURES
ABOVE THE GROUND ALLOW THE STRONG WINDS TO MIX TO THE SURFACE. AS
SUCH HAVE THE WIND ADVISORY EXTENDING INTO THE EVENING. DURING THE
LATE EVENING THE WINDS WILL SLOWLY DECLINE AS THE COOLER
TEMPERATURES AT THE SURFACE CAUSE MIXING TO DECLINE.
THERE STILL REMAINS SOME UNCERTAINTY WITH TRACK OF THE CLOSED UPPER
LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. MODELS IN GENERAL HAVE
SLOWED THE SYSTEM DOWN FROM YESTERDAY...WHICH SEEMS REASONABLE SINCE
THE CLOSED LOW WILL BE OUTSIDE OF THE MAIN UPPER LEVEL FLOW. THE
12Z NAM IS FURTHER SOUTH THAN IT WAS AT THIS TIME YESTERDAY WHILE
THE 12Z GFS IS FURTHER NORTH. PREFERENCE IS THE SREF AND NAM SINCE
THEY ARE SLOWER AND HAVE MORE RUN TO RUN CONSISTENCY WITH THE TRACK
OF THE CLOSED LOW AND ARE IN LINE WITH THE MAJORITY OF THE 6Z
GEFS...BUT FAVORED MOSTLY THE SREF FOR DETERMINING AREAS OF PRECIP.
SINCE THE NAM DRASTICALLY CUT BACK THE PRECIP. FOR THIS STORM
SYSTEM. GENERALLY THINKING A SLOWER TREND OF THE PRECIPITATION
MONDAY NIGHT THROUGH TUESDAY EVENING LOOKS TO BE THE WAY TO
GO...WITH LOCATIONS SOUTH OF HIGHWAY 24 LOOKING TO HAVE THE BEST
CHANCE FOR PRECIPITATION UNTIL THE STORM SYSTEM MOVES FURTHER EAST.
MONDAY EVENING HAVE SLIGHT CHANCES FOR PRECIPITATION OVER EASTERN
COLORADO AS THE 750-650MB SATURATES WITH ISENTROPIC LIFT OVER THAT
AREA. OVERNIGHT PRECIP. CHANCES INCREASE OVER THE ENTIRE AREA FROM
SOUTHWEST TO NORTHEAST AS ISENTROPIC LIFT OVERSPREADS THE AREA AND
MOISTURE AHEAD OF THE CLOSED LOW BEGINS TO MOVE NORTH INTO THE
AREA. SOME LOCATIONS IN EASTERN COLORADO MAY RECEIVE SOME SNOW WITH
LOW TEMPERATURES AROUND FREEZING.
TUESDAY PRECIP. CHANCES SLOWLY INCREASE AS THE CIRCULATION OF THE
CLOSED LOW CONTINUES TO BRING MOISTURE INTO THE AREA. BIGGEST
QUESTION IS HOW FAR NORTH THE MOISTURE WILL MAKE IT AS THE CLOSED
LOW MOVES EAST. WITH MORE UNCERTAINTY THAT THERE WILL BE MOISTURE
FOR THE ISENTROPIC LIFT TO WORK WITH AS ONE MOVES NORTH...HAVE
PRECIP. CHANCES DECREASING TO THE NORTH. WINDS WILL CONTINUE TO
DECREASE AS THE UPPER LEVEL WINDS DECLINE...BECOMING LIGHT BY
EVENING.
TUESDAY NIGHT PRECIPITATION CHANCES BEGIN TO DECREASE FROM EAST TO
WEST AS THE CLOSED LOW AND WRAP AROUND MOISTURE MOVE EAST.
FOR WEDNESDAY THROUGH SUNDAY THE MAIN FOCUS WILL BE THE CLOSED LOW
MOVING OUT OF THE AREA AND THUNDERSTORM CHANCES TOWARD THE END OF
THE WEEK.
WEDNESDAY THE CLOSED CONTINUES TO MOVE OUT OF THE AREA. BOTH THE
GFS AND ECMWF HAVE THE CLOSED LOW MOVING EAST OVER KANSAS...WHILE
THE NAM/SREF HAVE THE CLOSED LOW MOVING EAST OVER OKLAHOMA. DESPITE
THE DIFFERING POSITIONS OF THE LOW...THE MODELS AGREE THAT PRECIP.
CHANCES WILL DECLINE FROM EAST TO WEST DURING THE DAY AS THE CLOSED
LOW MOVES EAST. BEHIND THE CLOSED LOW A SHORT WAVE RIDGE MOVES OVER
THE AREA.
THURSDAY THE NEXT UPPER LEVEL TROUGH MOVES ON SHORE. BY FRIDAY
MORNING THE TROUGH WILL BE OVER THE INTER MOUNTAIN WEST. AT THE
SURFACE A LEE SIDE TROUGH DEVELOPS OVER EASTERN COLORADO AS THE
UPPER LEVEL TROUGH APPROACHES THE TRI-STATE AREA. FRIDAY SOUTHERLY
AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH BRING UP MOISTURE FROM
THE SOUTH. WITH INSTABILITY TO WORK WITH CANNOT RULE OUT A FEW
THUNDERSTORMS FROM FORMING OVER THE EASTERN PART OF THE AREA DURING
THE AFTERNOON. FRIDAY NIGHT A COLD FRONT MOVES THROUGH THE AREA.
OVER THE EAST THUNDERSTORM CHANCES CONTINUE WITH ELEVATED INSTABILITY
IN PLACE AND THE LOW LEVEL JET MOVING OVER THOSE AREAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1119 PM MDT SUN APR 1 2012
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY AFTERNOON...WITH MVFR
CIGS POSSIBLE MONDAY EVENING. THESE LOW CIGS ARE PRIMARILY TIED
TO MOISTURE ADVECTION AND PRECIP MOVING IN FROM THE SOUTH WHICH IS
STILL IN QUESTION AT BOTH TERMINALS DUE TO UNCERTAINTLY REGARDING
THE POSITION OF THE UPPER LOW MONDAY NIGHT. KGLD IS MOST LIKELY TO
SEE RAIN SHOWERS MONDAY EVENING...HOWEVER I WAS NOT CONFIDENT
ENOUGH TO ADD MORE THAN VCSH DURING THIS TAF CYCLE AND KEPT VFR IN
PLACE.
A COLD FRONT IS STILL ON TRACK TO PASS THROUGH THE REGION
FROM THE NW TO THE SE EARLY IN THE TAF PERIOD...WITH GUSTY WINDS
DEVELOPING AT BOTH TERMINALS. KGLD WILL BE FIRST TO SEE WINDS
SHIFT TO THE NORTH AND INCREASE IN THE 09Z-12Z PERIOD...WITH KMCK
IN THE 12Z-15Z TIME FRAME. THE STRONGEST WINDS WILL BE IN THE
MORNING WITH WIND GUSTS 40-45KT. WIND GUSTS AROUND 30KT WILL
CONTINUE THROUGH MONDAY EVENING AT BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR COZ090>092.
KS...WIND ADVISORY FROM 3 AM MDT /4 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001-013-027.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ002>004-014>016-028-029-041-042.
NE...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR NEZ079.
WIND ADVISORY FROM 7 AM THIS MORNING TO 10 PM CDT THIS EVENING
FOR NEZ080-081.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM....JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1051 PM MDT SUN APR 1 2012
.UPDATE...
ISSUED AT 1051 PM MDT SUN APR 1 2012
ADJUSTED START TIME OF WIND ADVISORY FOR WESTERN PART OF CWA BASED
ON 00Z GUIDANCE. LOOKS LIKE ADVISORY WINDS SHOULD DEVELOP OVER
THESE LOCATIONS AS EARLY AS 09Z...SPREADING EASTWARD THROUGH
12Z. STRONGEST WINDS ALOFT STILL LOOK TO BE IN THE 12-18Z TIME
PERIOD ACROSS THE AREA. 00Z GFS AND MAV GUIDANCE ARE THE MOST
BULLISH ON DAYTIME WINDS WITH SUSTAINED WINDS WITHIN WARNING
CRITERIA. LATEST NAM/SREF/RUC/HRRR ALL MUCH LESS...WITH WINDS
REMAINING WITHIN ADVISORY LEVELS. WITH THIS IN MIND I DECIDED TO
KEEP ADVISORY RATHER THAN UPGRADING AT THIS TIME.
UPDATE ISSUED AT 846 PM MDT SUN APR 1 2012
MADE FURTHER ADJUSTMENTS TO WIND FORECAST IN THE 06-15Z PERIOD
BASED ON LATEST RUC AND NAM TIMING OF FROPA. 00Z NAM STILL
INDICATING HIGH END ADVISORY/NEAR WARNING CRITERIA WINDS EARLY
MONDAY MORNING OVER EASTERN COLORADO. 00Z NAM AND LATEST SREF AND
RUC ARE LESS BULLISH THAN EARLIER ON WARNING CRITERIA. I HAVE
KEPT ADVISORY IN PLACE FOR NOW...AND WILL PROBABLY WAIT FOR 00Z
GFS TO MAKE FINAL DECISION ON FURTHER ADJUSTMENTS OR POSSIBLE
UPGRADES.
UPDATE ISSUED AT 554 PM MDT SUN APR 1 2012
MADE MINOR CHANGES TO WIND FORECAST TO ACCOUNT FOR WINDS
INCREASING QUICKER OVER WESTERN PARTS OF CWA AFTER 09Z TONIGHT AND
TO BUMP UP WIND GUST WORDING. I ALSO ADDED PATCHY BLOWING
DUST TO WEATHER GRIDS. IM CONCERNED WE COULD SEE WARNING CRITERIA
WINDS OVER WESTERN PARTS OF THE CWA MONDAY MORNING...HOWEVER NOT
A LOT OF NEW DATA TO LOOK AT AND MAKE A DECISION YET. WILL
PROBABLY WAIT UNTIL 00Z DATA COMES IN TO FURTHER FINE TUNE WIND
FORECAST. OTHER CHANGE WAS TO ADJUST TIMING OF PRECIP
MONDAY...TO INCLUDE RAIN SHOWERS MONDAY AFTERNOON IN THE SOUTH AND
WEST. 18Z NAM/GFS BOTH INDICATING AXIS OF FRONTOGENISIS MOVING NORTH
AND EAST ALONG WITH DECENT MID LEVEL MOISTURE IN THE 21-00Z
TIME-FRAME...SO EARLIER ARRIVAL OF RAIN CANT BE RULED OUT.
RED FLAG CONDITIONS CONTINUE OVER MANY LOCATIONS ACROSS THE
AREA...SO I PLAN ON LETTING THE RFW EXPIRE ON TIME AT 02Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
SOUTHWEST FLOW WILL BE OVER THE REGION TONIGHT. THE UPPER LOW WILL
MOVE INTO SOUTHWEST NEW MEXICO MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO TONIGHT. A COLD FRONT WILL PUSH SOUTH ACROSS
NORTHWEST KANSAS EARLY MONDAY.
SUBSIDENCE WILL CONTINUE OVER THE FA TONIGHT SO POPS WILL BE NIL.
SOME LIGHT PRECIPITATION WILL BE POSSIBLE MONDAY MORNING OVER
WESTERN PORTIONS OF EASTERN COLORADO WHILE DYNAMICS FROM THE UPPER
LOW ARE STILL REASONABLY CLOSE. BY MONDAY AFTERNOON THE LOW WILL
MOVE FAR ENOUGH SOUTH SO THAT CHANCES ARE MUCH LOWER. PLAN TO
CONTINUE SLIGHT CHANCE POPS IN EASTERN COLORADO MONDAY MORNING AND
THEN SILENT POPS MONDAY AFTERNOON. THE REST OF THE FA WILL HAVE NIL
POPS.
STRONG WINDS ARE THE MAIN FOCUS OF THE FORECAST FOR MONDAY. THE
GFS/NAM BOTH INDICATE GUSTS TO AROUND 50 MPH BETWEEN 12-15Z.
SUSTAINED WIND WILL BE STRONG ENOUGH TO SUPPORT A WIND ADVISORY ALL
DAY. SEE DETAILS ON THE WIND ADVISORY BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
MONDAY NIGHT WINDS WILL REMAIN GUSTY THROUGH THE NIGHT...WITH THE
STRONGEST GUSTS DURING THE EVENING...AS THE COOLER TEMPERATURES
ABOVE THE GROUND ALLOW THE STRONG WINDS TO MIX TO THE SURFACE. AS
SUCH HAVE THE WIND ADVISORY EXTENDING INTO THE EVENING. DURING THE
LATE EVENING THE WINDS WILL SLOWLY DECLINE AS THE COOLER
TEMPERATURES AT THE SURFACE CAUSE MIXING TO DECLINE.
THERE STILL REMAINS SOME UNCERTAINTY WITH TRACK OF THE CLOSED UPPER
LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. MODELS IN GENERAL HAVE
SLOWED THE SYSTEM DOWN FROM YESTERDAY...WHICH SEEMS REASONABLE SINCE
THE CLOSED LOW WILL BE OUTSIDE OF THE MAIN UPPER LEVEL FLOW. THE
12Z NAM IS FURTHER SOUTH THAN IT WAS AT THIS TIME YESTERDAY WHILE
THE 12Z GFS IS FURTHER NORTH. PREFERENCE IS THE SREF AND NAM SINCE
THEY ARE SLOWER AND HAVE MORE RUN TO RUN CONSISTENCY WITH THE TRACK
OF THE CLOSED LOW AND ARE IN LINE WITH THE MAJORITY OF THE 6Z
GEFS...BUT FAVORED MOSTLY THE SREF FOR DETERMINING AREAS OF PRECIP.
SINCE THE NAM DRASTICALLY CUT BACK THE PRECIP. FOR THIS STORM
SYSTEM. GENERALLY THINKING A SLOWER TREND OF THE PRECIPITATION
MONDAY NIGHT THROUGH TUESDAY EVENING LOOKS TO BE THE WAY TO
GO...WITH LOCATIONS SOUTH OF HIGHWAY 24 LOOKING TO HAVE THE BEST
CHANCE FOR PRECIPITATION UNTIL THE STORM SYSTEM MOVES FURTHER EAST.
MONDAY EVENING HAVE SLIGHT CHANCES FOR PRECIPITATION OVER EASTERN
COLORADO AS THE 750-650MB SATURATES WITH ISENTROPIC LIFT OVER THAT
AREA. OVERNIGHT PRECIP. CHANCES INCREASE OVER THE ENTIRE AREA FROM
SOUTHWEST TO NORTHEAST AS ISENTROPIC LIFT OVERSPREADS THE AREA AND
MOISTURE AHEAD OF THE CLOSED LOW BEGINS TO MOVE NORTH INTO THE
AREA. SOME LOCATIONS IN EASTERN COLORADO MAY RECEIVE SOME SNOW WITH
LOW TEMPERATURES AROUND FREEZING.
TUESDAY PRECIP. CHANCES SLOWLY INCREASE AS THE CIRCULATION OF THE
CLOSED LOW CONTINUES TO BRING MOISTURE INTO THE AREA. BIGGEST
QUESTION IS HOW FAR NORTH THE MOISTURE WILL MAKE IT AS THE CLOSED
LOW MOVES EAST. WITH MORE UNCERTAINTY THAT THERE WILL BE MOISTURE
FOR THE ISENTROPIC LIFT TO WORK WITH AS ONE MOVES NORTH...HAVE
PRECIP. CHANCES DECREASING TO THE NORTH. WINDS WILL CONTINUE TO
DECREASE AS THE UPPER LEVEL WINDS DECLINE...BECOMING LIGHT BY
EVENING.
TUESDAY NIGHT PRECIPITATION CHANCES BEGIN TO DECREASE FROM EAST TO
WEST AS THE CLOSED LOW AND WRAP AROUND MOISTURE MOVE EAST.
FOR WEDNESDAY THROUGH SUNDAY THE MAIN FOCUS WILL BE THE CLOSED LOW
MOVING OUT OF THE AREA AND THUNDERSTORM CHANCES TOWARD THE END OF
THE WEEK.
WEDNESDAY THE CLOSED CONTINUES TO MOVE OUT OF THE AREA. BOTH THE
GFS AND ECMWF HAVE THE CLOSED LOW MOVING EAST OVER KANSAS...WHILE
THE NAM/SREF HAVE THE CLOSED LOW MOVING EAST OVER OKLAHOMA. DESPITE
THE DIFFERING POSITIONS OF THE LOW...THE MODELS AGREE THAT PRECIP.
CHANCES WILL DECLINE FROM EAST TO WEST DURING THE DAY AS THE CLOSED
LOW MOVES EAST. BEHIND THE CLOSED LOW A SHORT WAVE RIDGE MOVES OVER
THE AREA.
THURSDAY THE NEXT UPPER LEVEL TROUGH MOVES ON SHORE. BY FRIDAY
MORNING THE TROUGH WILL BE OVER THE INTER MOUNTAIN WEST. AT THE
SURFACE A LEE SIDE TROUGH DEVELOPS OVER EASTERN COLORADO AS THE
UPPER LEVEL TROUGH APPROACHES THE TRI-STATE AREA. FRIDAY SOUTHERLY
AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH BRING UP MOISTURE FROM
THE SOUTH. WITH INSTABILITY TO WORK WITH CANNOT RULE OUT A FEW
THUNDERSTORMS FROM FORMING OVER THE EASTERN PART OF THE AREA DURING
THE AFTERNOON. FRIDAY NIGHT A COLD FRONT MOVES THROUGH THE AREA.
OVER THE EAST THUNDERSTORM CHANCES CONTINUE WITH ELEVATED INSTABILITY
IN PLACE AND THE LOW LEVEL JET MOVING OVER THOSE AREAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 531 PM MDT SUN APR 1 2012
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE
PERIOD...HOWEVER...THERE IS A CHANCE FOR MVFR CIGS VERY LATE IN THE
PERIOD. HAVE HELD OFF ON MENTIONING AT THIS TIME AND WILL LET
SUBSEQUENT SHIFTS ANALYZE THIS. OTHERWISE...A COLD FRONT WILL PUSH
THROUGH THE AREA DURING THE MORNING HOURS. WINDS WILL SWITCH TO
THE NORTH AND BECOME WINDY WITH GUSTS IN THE 40 KNOT RANGE
LIKELY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR COZ090>092.
KS...WIND ADVISORY FROM 3 AM MDT /4 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001-013-027.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ002>004-014>016-028-029-041-042.
NE...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR NEZ079.
WIND ADVISORY FROM 7 AM TO 10 PM CDT MONDAY FOR NEZ080-081.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM....JTL
AVIATION...BAS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
637 PM CDT TUE APR 3 2012
.UPDATE...
UPDATE ISSUED AT 528 PM CDT TUE APR 3 2012
USED THE HRRR MODEL TRENDS FOR THIS FORECAST. A FEW SHOWERS HAVE
DEVELOPED ALONG THE NORTHWEST EDGE OF OUR CWA AND THAT IS EXPECTED
TO CONTINUE FOR THE NEXT COUPLE OF HOURS. MAJORITY OF MODELS WANT
TO DEVELOP AN MCS OVER CENTRAL MISSOURI...MOVE IT EAST THEN
SOUTHEAST WHICH MEANS IT MIGHT CLIP THE SOUTHWEST INDIANA AREA. SO
WENT WITH HIGH CHANCE AND LIKELY POPS OVER THE NORTHERN SECTIONS
TONIGHT. BLENDED A BIT DURING THE MORNING HOURS SO THAT IT IS A
SMOOTHER TRANSITION ACROSS THE SOUTHERN SECTIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM CDT TUE APR 3 2012
A WEAK SHORT WAVE ALOFT WILL BEGIN TO INTERACT WITH A SURFACE
FRONT LIFTING NORTH OF THE REGION TONIGHT. ACTUALLY WAITING FOR
CONVECTION TO START FIRING OVER THE THE WESTERN HALF OF THE
REGION ANYTIME LATE THIS AFTERNOON. SURFACE HEATING AHEAD OF THIS
SYSTEM...ESP EAST OF THE MS RIVER WILL HELP GENERATE SURFACE BASED
LI VALUES IN THE -4 TO -8 RANGE. IF DEBRIS CLOUDS DO NOT INHIBIT
THIS INSTABILITY FROM FORMING...SOME OF THE THUNDERSTORMS THAT
DEVELOP COULD BE QUITE STRONG TO SEVERE IN THE LATE AFTERNOON INTO
EARLY EVENING. DUE TO RELATIVELY LIGHT FLOW ALOFT...IF ANY
ISOLATED STRONG CONVECTION DOES MANAGE TO DEVELOP...IT WILL
LIKELY BE PULSE-TYPE CLUSTERS IN NATURE...WITH RAPID GROWTH AND DECAY
OF EMBEDDED CELLS.
ONCE THE SFC FRONT AND H50 TROF MOVE NORTH OF THE FORECAST AREA
LATER TONIGHT...WE WILL BE UNDER THE INFLUENCE OF RICH MOIST SW
FLOW AT ALL LEVELS. THOUGH NO REAL TRIGGER IS INDICATED AT THIS
TIME...THIS TYPE OF PATTERN COULD PRODUCE SCATTERED SHOWERS AND
STORMS AT ABOUT ANY TIME. THEREFORE...WILL LEAVE AT LEAST SCT
MENTIONING IN THE FORECAST ALL OF TONIGHT FOR OFF AND ON
SHOWERS/STORMS. GOOD NEWS IS THAT WE WILL LOSE MUCH OF THE DAYTIME
HEATING/INSTABILITY AND MID LEVEL FORCING...SO SEVERE ASPECT WILL
BE LITTLE TO NULL.
LITTLE CHANGE WITH THE MODELS/ENSEMBLES FOR WED. CONTINUE TO SHOW
AN INITIALLY SLOW MOVING CLOSED H5 LOW MOVING ACROSS THE CENTRAL
PLAINS AND INTO W TN BY 06Z FRI AS SURFACE LOW ALSO MOVES SE
ACROSS MAINLY THE SW PART OF THE PAH FORECAST AREA. ACCORDINGLY
THE BEST CHANCE OF SHOWERS/TSTMS WILL GENERALLY BE WEDNESDAY
AFTERNOON INTO WED NIGHT EXCEPT IN THE OZARK FOOTHILLS OF SE MO
WHERE THE BEST CHANCES MAY ARRIVE AS EARLY AS WEDNESDAY MORNING.
A SURFACE HIGH PUSHING S INTO THE GREAT LAKES REGION WILL BRING
DRIER AIR THURSDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE APR 3 2012
THE LATEST MODELS AGREE THAT FRIDAY WILL BE A VERY DRY DAY WITH SOME
WIND APPROACHING CRITICAL FIRE WEATHER THRESHOLDS. ALSO WITH WINDS
MAINLY OUT OF THE NORTHEAST WOULD NOT EXPECT MUCH OF A REBOUND ON RH
DURING THE DAY LIKE THE MODELS ARE SUGGESTING. SO WOULD EXPECT AT
LEAST AN INCREASED FIRE DANGER ALTHOUGH FUELS MAY BE WET FROM
PRECEDING RAINS. WILL PULL DEW POINTS DOWN FOR FRIDAY AT LEAST IN
THE MIDDLE 30S FOR NOW AND MONITOR CLOSELY FOR EVEN DRIER WEATHER.
FORECAST SOUNDING WOULD SUGGEST NEAR 30 AND THE NAM WOULD SUGGEST
MID 20S DEW POINTS. WINDS SHOULD DECREASE SATURDAY AS SURFACE HIGH
SETTLES OVER THE HEARTLAND.
BOTH THE 12Z TUE GFS AND 00Z TUE ECMWF ARE IN UNUSUALLY FAIR
AGREEMENT WITH A COLD FRONT TRAVERSING THE REGION SATURDAY NIGHT
INTO SUNDAY MORNING. HOWEVER THE ECMWF IS MUCH DRIER WITH ONLY
SPOTTY QPF...WHILE THE WETTER GFS HAS MORE SOLID COVERAGE AMOUNTS
ARE MEAGER WITH LESS THAN A QUARTER INCH ANYWHERE. HOWEVER THEY BOTH
AGREE THE PRECIP WILL BE POST FRONTAL SHOULD ANY OCCUR. SO WILL
LEAVE IN SLGT CHC IN SUNDAY MORNING AND MIGHT HAVE TO TRIM POPS A
BIT PRIOR TO SUNDAY MORNING TO BETTER REFLECT POST FRONTAL PRECIP.
THERE WILL BE A REINFORCING FRONT MONDAY BRINGING YET ANOTHER SHOT
AT SOME PRECIP. AFTER THAT HIGH PRESSURE RETURNS NEXT WEEK.
AS FOR TEMPS WILL GO WITH ABOVE NORMAL TEMPS OR PERSISTENCE FCST
UNTIL THE REINFORCING FRONT AND THEN WILL ACTUALLY HAVE A SHOT AT
BELOW NORMAL TEMPS BY TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 637 PM CDT TUE APR 3 2012
ISOLATED SHRA/TSTM POSSIBLE AT KCGI/KPAH MAINLY FROM 02Z-08Z...SO
INCLUDED CB. VFR CONDITIONS EXPECTED AT KCGI/KPAH...WITH MVFR
CIGS LIKELY AFTER 08Z AT KEVV/KOWB...IMPROVING TO VFR AFTER 15Z.
SHRA/TSTM CHANCES RETURN TO KCGI/KPAH AFTER 15Z...AND AT KEVV/KOWB
AFTER 18Z...WITH INCREASING CHANCES THROUGH THE AFTERNOON AT ALL
SITES. WINDS WILL GENERALLY BE FROM THE SW TO W AT 5 TO 15 KTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...PS
SHORT TERM...GM
LONG TERM....KH
AVIATION...RST
AREA FORECAST DISCUSSION
NWS JACKSON KY
141 AM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 945 PM EDT SUN APR 1 2012
A NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED NORTH OF A
LINE FROM INDIANAPOLIS TO DAYTON OVER THE PAST FEW HOURS. THIS IS
MOST LIKELY TH LINE OF SHOWERS AND STORMS THAT THE HRRR HAS BEEN
PICKING UP ON. THUS...THIS IS THE LINE THAT IS MOST LIKELY TO AFFECT
US TONIGHT. BASED ON THE MOVEMENT AND SPEED OF THIS LINE...IT WILL
NOT MAKE IT INTO THE BLUEGRASS UNTIL 3 OR 4 AM AT THE EARLIEST. WITH
THE SURFACE ALREADY DECOUPLING UNDER CLEAR SKIES...WIND THREAT FROM
ANY OF THESE STORMS APPEARS VERY MARGINAL AT BEST. ANY THREAT WILL
LIKELY COME FROM LARGE HAIL...AND EVEN THIS IS QUESTIONABLE.
THUS...SEVERE THREAT LOOKS MUCH MORE MARGINAL NOW...BUT STILL CANNOT
BE RULED OUT. HAVE TRIMMED BACK POPS ACROSS THE SOUTHWEST A BIT MORE
AS IT APPEARS MOST LIKELY TO AFFECT THE NORTHEASTERN TWO THIRDS OF
THE FORECAST AREA. KEPT SOME POPS AROUND DURING THE MORNING ACROSS
THE SOUTHEAST AS WE COULD HAVE SOME BACKBUILDING ALONG THIS LINE OF
SHOWERS AND STORMS. OTHERWISE...THE ACTIVITY SHOULD COME TO AN END
THERE BY MIDDAY...WITH THE AFTERNOON TURNING DRIER.
UPDATE ISSUED AT 738 PM EDT SUN APR 1 2012
AFTER A CLOUDY DAY WITH SOME RAIN SHOWERS...SKIES HAVE CLEARED OUT
ACROSS EASTERN KENTUCKY THIS EVENING. IN ACCORDANCE...HAVE ALTERED
THE FORECAST TO REFLECT MORE CLEAR SKIES OVER THE NEXT SEVERAL HOURS.
HOWEVER...SHOWERS AND A FEW STORMS ARE ALREADY BEGINNING TO DEVELOP
TO THE NORTH FROM JUST NORTHWEST OF INDIANAPOLIS TO JUST NORTH OF
WILMINGTON OHIO. THE HRRR SHOWS THIS ACTIVITY PUSHING SOUTH INTO OUR
NORTHERN AREAS CLOSE TO MIDNIGHT. IT LOOKS INCREASINGLY LIKELY ONLY
THE EASTERN COUNTIES WILL STAND THE BEST CHANCE OF RAIN TONIGHT...SO
HAVE REMOVED POPS FROM OUR SOUTHWEST ZONES. OTHERWISE...MADE SOME
MINOR ADJUSTMENT TO TEMPERATURES AND WINDS.
UPDATE ISSUED AT 526 PM EDT SUN APR 1 2012
LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH
SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD
ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT
HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH
STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO
SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS
BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE
GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER
04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING
ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING
ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO
INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN.
THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO
GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A
HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE
ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS
UNFOLD OVER THE NEXT 3 TO 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EDT SUN APR 1 2012
THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH
THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY
BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY
PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST
OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES.
THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO
DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO
A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT
LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF
IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET
IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS
LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK
QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST.
AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE
HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON.
WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH
AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL
MOISTURE...WHICH MAY RECHARGE US SOMEWHAT.
THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA
DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE
MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE
MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE
BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING
OFF SOME ISOLATED CONVECTION AS THIS OCCURS.
AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH
READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE
COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE
FOR MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EDT SUN APR 1 2012
A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED
DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF
WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST
WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT
PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD.
OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN
WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING
DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN.
EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT
NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS
GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY
IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY
SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR
TUE NIGHT.
THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO
WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA
BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A
TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN
HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN
PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS
THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY
ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF
THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS
MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI.
AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY
GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE
IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER
LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF
DAYS OF THE PERIOD.
AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE
WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE
EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT
THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON
TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND
CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE
NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG
THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE
SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO
SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK
JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM
TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI.
FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER
LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF
RUNS.
TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN
MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF
THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1 AM EDT MON APR 2 2012
VFR CONDITIONS NOTED AT ISSUANCE WITH A LINE OF CONVECTION DROPPING
SOUTH INTO NERN KY. AREAS NORTH AND EAST OF A LINE FROM KI39 THRU
KJKL TO KPBX WILL HAVE THE BEST CHANCE OF SEEING PRECIP...HOWEVER
CIGS ARE GENERALLY EXPECTED TO REMAIN LOW END VFR THRU THE REMAINDER
OF THE OVERNIGHT. FOG WILL BE POSSIBLE AGAIN AND HAVE TRENDED A
LITTLE MORE FOR LOZ AND SME. LLWS WILL ALSO BE A FACTOR OVERNIGHT
WITH A -KT LOW LEVEL JET OVERHEAD AND LIGHT TO CALM SFC WINDS. SHRA
WILL SLIDE OFF TO THE EAST AS FOG DISSIPATES SHORTLY AFTER
SUNRISE...BUT LOW CIGS MY LINGER THRU THE MORNING AROUND M/VFR
THRESHOLDS. WINDS ARE EXPECTED TO PICK UP AGAIN DURING THE MORNING
WITH A NE COMPONENT AT THE SFC UP THRU ABOUT 3 KFT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...MB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
807 PM EDT TUE APR 3 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA TONIGHT, BRINGING
THE CHANCE OF SHOWERS AND THUNDERSTORMS. A LINGERING FRONTAL
BOUNDARY BEHIND THE LOW WILL SLIDE SOUTH OF THE AREA AND END THE
CHANCE OF SHOWERS BY WEDNESDAY AFTERNOON. HIGH PRESSURE WILL THEN
BRING DRY AND SEASONABLE CONDITIONS INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A NEAR ZONAL FLOW ON THE
NORTHERN PERIPHERY OF A WEAK RIDGE ACROSS THE OHIO VALLEY. AT THE
SURFACE, A 1009MB LOW IS LOCATED ILLINOIS WITH A WARM FRONT
EXTENDING EASTWARD ACROSS CENTRAL OHIO. A CONVECTIVE COMPLEX
CONTINUES TO WEAKEN AS IT SLIDES SOUTHEAST ACROSS EASTERN OHIO.
THIS EVENING...DRY AIR AT THE SURFACE, INDICATED BY TD DEPRESSIONS
OF 25-30F SHOULD CONTINUE TO LIMIT THE EASTWARD PROGRESSION OF
SHOWERS INTO THE AREA. THE WARM FRONT WILL CONTINUE TO PUSH INTO THE
AREA FROM THE SOUTHWEST AS THE SURFACE LOW TREKS ACROSS THE OHIO
VALLEY. THIS WILL ALLOW FOR TEMPS TO CONTINUE TO WARM INTO THE
EVENING.
TONIGHT...THE SURFACE LOW WILL MOVE INTO WESTERN PENNSYLVANIA AS
THE WARM FRONT STRADDLES THE AREA. NAM/GFS INDICATE AN AREA OF WEAK
ELEVATED INSTABILITY PUSHING ACROSS THE AREA AND ALLOWING FOR THE
CHANCE OF THUNDERSTORMS PRIMARILY SOUTH OF THE PITTSBURGH METRO
OVERNIGHT. BY DAWN, THE FRONTAL BOUNDARY WILL HAVE PUSHED
SOUTHWARD TO THE MASON-DIXON LINE, WITH LINGERING SHOWERS ALONG
AND SOUTH OF THE BOUNDARY. OVERNIGHT LOWS ARE A FEW DEGREES WARMER
THAN LAMP GUIDANCE, RANGING FROM THE LOWER 40S NORTH OF THE
BOUNDARY ALONG THE I-80 CORRIDOR TO THE MID 50S IN NORTH-CENTRAL
WV.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
GFS/ECMWF EQUIV POT TEMP AND DEW POINT GRADIENTS INDICATE THE
FRONTAL BOUNDARY SLIDING FROM THE MASON-DIXON LINE INTO CENTRAL WV
BY 21Z FRIDAY. BEFORE THE BOUNDARY SHIFTS SOUTHWARD, NAM/GFS
INDICATE ENOUGH INSTABILITY TO SUPPORT CHANCE OF THUNDER WEDNESDAY
LATE MORNING INTO THE EARLY AFTERNOON ACROSS PORTIONS OF NORTH-
CENTRAL WV. HIGH PRESSURE APPROACHING FROM THE NORTHWEST ALONG
WITH DRIER AND STABLE AIR WILL ALLOW FOR A DRY FORECAST FOR THE
REMAINDER OF THE DAY ACROSS THE AREA. HIGH TEMPS FOR WEDNESDAY ARE
A FEW DEGREES ABOVE SEASONAL NORMALS.
THERE IS OPERATIONAL MODEL AGREEMENT THAT A SURFACE HIGH WILL MOVE
FROM CENTRAL CANADA INTO THE GREAT LAKES WEDNESDAY NIGHT INTO
FRIDAY. THIS WILL ALLOW FOR CLEARING SKIES WEDNESDAY NIGHT AND
ABUNDANT SUNSHINE THURSDAY AND FRIDAY. TEMPERATURES ARE FORECAST TO
NEAR NORMAL SEASONAL VALUES EACH DAY. WITH THE HIGH FUNNELING IN
COLDER, CANADIAN AIR, FREEZES WILL AGAIN BE POSSIBLE NORTHEAST OF
PITTSBURGH ON THURSDAY AND FRIDAY MORNING.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE
OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO
VALLEY INTO AT LEAST SUNDAY AND PERHAPS MONDAY. THEN UPPER LEVEL
RIDGE BUILDING ACROSS THE HIGH PLAINS OF CENTRAL CANADA AND THE U.S.
THIS WILL CAUSE INCREASED NORTHWEST FLOW DOWNWIND INTO THE UPPER
OHIO VALLEY, WITH A SHOWERY COLD FRONTAL PASSAGE EITHER MONDAY OR
TUESDAY.
REGARDING TEMPERATURES, EXPECT A LARGER THAN NORMAL DIURNAL RANGE
SATURDAY DUE TO RELATIVELY CLEAR SKIES ENHANCING RADIATIVE EFFECTS.
LOWS FRIDAY NIGHT CAN BE ABOUT 5 DEGREES COLDER THAN NORMAL, WHILE
SATURDAY AFTERNOON HIGHS CAN BE UP TO 10 DEGREES WARMER THAN NORMAL.
DUE TO COLD FRONTAL PASSAGE TIMING UNCERTAINTY, FORECASTED
TEMPERATURES SUNDAY INTO MONDAY TO BE NEAR SEASONABLE. BY TUESDAY,
THE POSTFRONTAL COOL DOWN WILL CAUSE TEMPERATURES TO BE AT LEAST 5
DEGREES COLDER THAN NORMAL.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SKIES CLEAR TO SCT FIRST PART OF NIGHT. SEVERAL SREF MODEL OUTPUT
MEMBERS SHOW A SECOND COMPLEX OF SHOWERS AND SCATTERED
THUNDERSTORMS, WITH MVFR FLIGHT CONDITIONS, MOVING SOUTHEASTWARD
ACROSS THE I-70 CORRIDOR AND AREAS SOUTH LATE TONIGHT INTO
WEDNESDAY MORNING, 07Z-15Z, IN ASSOCIATION WITH THE PASSAGE OF A
LOW PRESSURE CENTER AND COLD FRONT.
POST FRONTAL DRYING WILL RESTORE VFR WEDNESDAY AFTERNOON.
SURFACE WINDS BECOME NORTHWEST LATE TONIGHT AND WEDNESDAY AT 5 TO
10 KTS INCREASING TO 10 TO 15 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
EXPECT VFR DUE TO HIGH PRESSURE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
346 PM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND DROP TEMPERATURES
TO NEAR FREEZING ACROSS PORTIONS OF THE AREA TONIGHT. A FRONTAL
BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
TOMORROW NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK WINDS
ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR IS EVIDENT SLIDING SOUTHEASTWARD ACROSS WESTERN PA. AT THE
SURFACE, A 1025MB HIGH IS CENTERED OVER THE HUDSON BAY WITH HIGH
PRESSURE EXTENDING SOUTHEASTWARD INTO THE GREAT LAKES.
TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE RIDGE
WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLEAR SKIES CAN BE
EXPECTED UNTIL NEAR DAWN WHEN CIRRUS BEGINS TO SPILL INTO THE AREA
FROM THE WEST.
FOR TEMPS, A MAV/MET BLEND SEEMED REASONABLE WITH THE BEST
RADIATIONAL COOLING TONIGHT CLOSEST TO THE SURFACE HIGH
NORTHEAST OF PITTSBURGH. A FREEZE WARNING HAS BEEN ISSUED FOR
AREAS NORTHEAST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
PATCHY FROST IS ALSO FORECAST FOR THE PITTSBURGH METRO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
THERE IS NAM/ECMWF AGREEMENT THAT A MID-LEVEL SHORT WAVE ALONG WITH A
WEAK SURFACE LOW WILL MOVE FROM THE MISSOURI VALLEY ACROSS THE OHIO
VALLEY ON TUESDAY. THIS WILL ALLOW FOR A WARM FRONT TO APPROACH FROM
THE SOUTHWEST DURING THE DAY. MODELS INDICATE THE SHORT WAVE
DE-AMPLIFYING AND THE SURFACE LOW BECOMING POORLY DEFINED AS THE
PAIR MOVE INTO THE AREA IN THE 00Z-06Z WEDNESDAY TIME FRAME. WITH
THIS IN MIND, HAVE SLOWED POPS AND WILL KEEP THE FORECAST DRY
UNTIL 21Z WHEN WEAK ELEVATED INSTABILITY BEGINS TO MOVE INTO
EASTERN OHIO AND BRINGS THE POSSIBILITY OF THUNDERSTORMS.
LINGERING WAVE ENERGY WILL PUSH ACROSS THE AREA AS THE FRONTAL
BOUNDARY BECOMES STATIONARY. THUS, THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS WILL BE TUESDAY NIGHT.
DESPITE THE FRONTAL BOUNDARY BEING SLOW TO APPROACH FROM THE
SOUTHWEST, WARM AIR ADVECTION ALOFT WILL ALLOW FOR 850 TEMPS TO
WARM INTO THE 10-14C RANGE BY 00Z WEDNESDAY. HIGHS TUESDAY ARE
FORECAST AT 10 DEGREES ABOVE NORMAL. TUESDAY NIGHT TEMPS WILL BE SLOW
TO DECREASE AS THE BOUNDARY MOVES NORTH INTO THE AREA. LOWS WILL
RANGE FROM THE LOWER 50S ACROSS NORTH-CENTRAL WV TO NEAR 40 NORTH
OF THE I-80 CORRIDOR.
WEDNESDAY THROUGH THURSDAY...THE FRONTAL BOUNDARY WILL BEGIN TO SAG
SOUTHWARD ON WEDNESDAY, WITH THE CHANCE OF SHOWERS ENDING ACROSS
THE SOUTH BY THE AFTERNOON. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH WITH A DRY FORECAST THROUGH THURSDAY. TEMPERATURES
THROUGH THIS PERIOD WILL BE NEAR SEASONAL VALUES WITH THE
POTENTIAL FOR ANOTHER FREEZE NORTHEAST OF PITTSBURGH ON WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE
OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO
VALLEY INTO DAYTIME SUNDAY. CONSENSUS OF MODELS THEN SHOW THE UPPER
LEVEL JET STREAM PATTERN BECOMING MORE ZONAL WITH A SOUTHWEST
ORIENTATION. THIS ZONAL UPPER FLOW WILL STEER A COLD FRONTAL BAND OF
SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY SUNDAY NIGHT INTO
MONDAY.
FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAEFS MODEL OUTPUT,
TO BE NEAR NORMAL FRIDAY, FOLLOWED BY A PREFRONTAL WARM UP SATURDAY
AND SUNDAY TO VALUES UP TO 10 DEGREES ABOVE NORMAL. TEMPERATURES
MONDAY SHOULD BE CLOSER TO NORMAL DUE TO CLOUDS AND SHOWERS AND
POTENTIAL POSTFRONTAL COOLING, ALTHOUGH THE LATTER WILL BE LIMITED
BY THE SOUTHWEST WINDS ALOFT.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT MAINLY CLEAR SKIES
TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST AT NO MORE THAN 8
KTS THROUGH EARLY EVENING, THEN BECOME LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH SATURDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. VFR WEDNESDAY THROUGH
SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR MDZ001.
OH...NONE.
PA...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
158 PM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND DROP
TEMPERATURES NEAR FREEZING TONIGHT ACROSS PORTIONS OF THE AREA. A
FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
TOMORROW NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO CLEAR
OUT THE SKY GRIDS THROUGH THE PRE-DAWN HOURS ON TUESDAY.
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK
WINDS ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR IS EVIDENT SLIDING SOUTHEASTWARD ACROSS WESTERN PA. AT
THE SURFACE, A 1025MB HIGH IS CENTERED OVER THE HUDSON BAY WITH
HIGH PRESSURE EXTENDING SOUTHEASTWARD INTO THE GREAT LAKES.
TODAY AND TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE
RIDGE WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLEAR SKIES CAN BE
EXPECTED THROUGH THIS PERIOD.
TEMPS ARE IN LINE WITH THE PREVIOUS FORECAST, SO FORECAST HIGHS
CONTINUE TO BE A FEW DEGREES WARMER THAN A MAV/MET BLEND AND
SEASONAL NORMS. THE BEST RADIATIONAL COOLING TONIGHT WILL OCCUR
CLOSEST TO THE SURFACE HIGH, WHICH WILL BE NORTHEAST OF PITTSBURGH.
CURRENTLY, THE MOST CONFIDENCE IN A FREEZE IS ALONG THE I-80 CORRIDOR.
PATCHY FROST IS FORECAST FOR AREAS NORTHEAST OF PITTSBURGH AND
ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HAVE MAINTAINED A FORECAST OF CHANCE SHOWERS AND THUNDERSTORMS IN
THE WARM ADVECTION REGIME OF THE AFOREMENTIONED LOW PRESSURE SYSTEM
ON TUESDAY AFTERNOON AND WITH THE COLD FRONT ON TUESDAY NIGHT.
HIGH PRESSURE WILL FOLLOW WITH DRY AND COOLER CONDITIONS WEDNESDAY.
THE SHORT TERM TEMPERATURE FORECAST WAS COMPLETED USING A BLEND
OF GUIDANCE AND FEATURES READINGS FROM 5 TO 10 DEGREES ABOVE
NORMAL TUESDAY...AND NEAR NORMAL FOR WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO
THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS
THE GREAT LAKES.
A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER
MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF
ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA.
HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST
WITH A CHANCE OF SHOWERS LATE SUNDAY.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN
WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT NO MORE THAN FEW VFR
CUMULUS THIS AFTERNOON, THEN NO MORE THAN FEW CIRRUS TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST NO MORE THAN 10
KTS THIS AFTERNOON, GOING LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH SATURDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. OTHERWISE VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1120 AM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND DROP
TEMPERATURES NEAR FREEZING TONIGHT ACROSS PORTIONS OF THE AREA. A
FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
LATE IN THE DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TRENDS IN TEMPS AND SKY.
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK
WINDS ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR ABOVE 850MB IS EVIDENT SLIDING SOUTHEASTWARD ACROSS
WESTERN PA. AT THE SURFACE, A 1025MB HIGH IS CENTERED OVER THE
HUDSON BAY WITH HIGH PRESSURE EXTENDING SOUTHEASTWARD INTO THE
GREAT LAKES. A NORTHEASTERLY LOW-LEVEL FLOW IS PUSHING
STRATOCUMULUS, WHICH IS DIMINISHING, SOUTHWEST OF THE PITTSBURGH
METRO.
TODAY AND TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE
RIDGE WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLOUD COVERAGE WILL
CONTINUE TO DIMINISH EARLY TODAY WITH CLEARING ACROSS THE AREA.
TEMPS ARE IN LINE WITH THE PREVIOUS FORECAST, SO FORECAST HIGHS
CONTINUE TO BE A FEW DEGREES WARMER THAN A MAV/MET BLEND AND
SEASONAL NORMS. THE BEST RADIATIONAL COOLING TONIGHT WILL OCCUR
CLOSEST TO THE SURFACE HIGH, WHICH WILL BE NORTHEAST OF PITTSBURGH.
CURRENTLY, THE MOST CONFIDENCE IN A FREEZE IS ALONG THE I-80 CORRIDOR.
PATCHY FROST IS FORECAST FOR AREAS NORTHEAST OF PITTSBURGH AND
ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HAVE MAINTAINED A FORECAST OF CHANCE SHOWERS AND THUNDERSTORMS IN
THE WARM ADVECTION REGIME OF THE AFOREMENTIONED LOW PRESSURE SYSTEM
ON TUESDAY AFTERNOON AND WITH THE COLD FRONT ON TUESDAY NIGHT.
HIGH PRESSURE WILL FOLLOW WITH DRY AND COOLER CONDITIONS WEDNESDAY.
THE SHORT TERM TEMPERATURE FORECAST WAS COMPLETED USING A BLEND
OF GUIDANCE AND FEATURES READINGS FROM 5 TO 10 DEGREES ABOVE
NORMAL TUESDAY...AND NEAR NORMAL FOR WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO
THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS
THE GREAT LAKES.
A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER
MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF
ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA.
HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST
WITH A CHANCE OF SHOWERS LATE SUNDAY.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN
WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT POSTFRONTAL COLD
POOL STRATOCUMULUS CLOUD BANK TO CONTINUE TO ERODE THIS MORNING,
NORTHEAST TO SOUTHWEST. SO REMAINING MVFR CEILINGS SHOULD BE AT
VFR LEVELS BY 16Z AND DISSIPATED BY 17Z. EXPECT VFR CLEAR SKIES
TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST NEAR 10 KTS
TODAY, THEN GO LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. OTHERWISE VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 PM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 1228 PM EDT MON APR 2 2012
BASED ON 12Z RAOB FROM KINL AND LOOKING AT NAM SNDG FOR KIWD FOR
THIS AFTERNOON...I AM SKEPTICAL ABOUT SHRA/TSRA CHCS THIS AFTERNOON.
DESPITE INCREASE IN WAA AT NOSE OF 30 KT 850 MB JET AND INCREASE IN
8H THETA-E VALUES BY LATE AFTERNOON...NAM MODEL SNDG FOR KIWD LIFTED
AT 800 MB STILL INDICATED A CAP AT AROUND 650 MB WITH OVER 25 J/KG
OF CIN AND LESS THAN 200 J/KG. THIS CAP IS ALSO REFLECTED IN 12Z
KINL SNDG. AS A RESULT OF INSTABILITY BEING MARGINAL AT BEST...HAVE
DECIDED TO TRIM BACK POPS TO SLIGHT CHC FOR GOGEBIC AND ONTONAGON
THIS AFTERNOON AND REMOVE POPS FARTHER TO THE EAST.
&&
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 143 PM EDT MON APR 2 2012
SUNSHINE AND ASSOC MIXING OVER THE TAF SITES TODAY ALONG WITH AN
INCREASE IN MID CLOUD COVER FROM THE WEST THIS EVENING SHOULD
PREVENT THE DEVELOPMENT OF LOW CLOUDS AND FOG TONIGHT. EXPECT VFR
CONDITIONS TO CONTINUE AT ALL THE TAF SITES UNTIL LATE TONIGHT INTO
WEDNESDAY WHEN WINDS COME AROUND TO THE NNW BEHIND FRONTAL BOUNDARY
MOVING THROUGH THE AREA. DUE TO WEAK FORCING ALONG THE FRONTAL
BOUNDARY...SHOWER COVERAGE WILL LIKELY BE SCATTERED AND FAIRLY
LIGHT. ALSO THERE IS LESS CERTAINTY THAT SHOWERS WILL BE THE
PREVAILING CONDITION AT THE TAF SITES TONIGHT INTO WEDNESDAY EXCEPT
FOR MAYBE KIWD WHICH COULD SEE SOME AFTERNOON CONVECTION MOVE IN
THERE THIS EVENING. AT KCMX AND KSAW WILL CONTINUE MENTION OF JUST
VICINITY SHRA IN TAF. NOT EXPECTING MUCH REDUCTION IN VSBY FROM ANY
OF THE SHOWERS...BUT COULD SEE AN MVFR CLOUD DECK DEVELOP IN THE
WAKE OF THE FRONTAL BOUNDARY LATE TONIGHT AND WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 PM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 1228 PM EDT MON APR 2 2012
BASED ON 12Z RAOB FROM KINL AND LOOKING AT NAM SNDG FOR KIWD FOR
THIS AFTERNOON...I AM SKEPTICAL ABOUT SHRA/TSRA CHCS THIS AFTERNOON.
DESPITE INCREASE IN WAA AT NOSE OF 30 KT 850 MB JET AND INCREASE IN
8H THETA-E VALUES BY LATE AFTERNOON...NAM MODEL SNDG FOR KIWD LIFTED
AT 800 MB STILL INDICATED A CAP AT AROUND 650 MB WITH OVER 25 J/KG
OF CIN AND LESS THAN 200 J/KG. THIS CAP IS ALSO REFLECTED IN 12Z
KINL SNDG. AS A RESULT OF INSTABILITY BEING MARGINAL AT BEST...HAVE
DECIDED TO TRIM BACK POPS TO SLIGHT CHC FOR GOGEBIC AND ONTONAGON
THIS AFTERNOON AND REMOVE POPS FARTHER TO THE EAST.
&&
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EDT MON APR 2 2012
LOW CLOUDS AND SOME FOG WILL AFFECT CMX AND SAW THROUGH MID MORNING.
MAIN IMPACT WILL BE CIGS BLO ALTERNATE AIRPORT MINS BUT BRIEF VSBY
OF LIFR/IFR POSSIBLE AS WELL. PROBLEM AT IWD WILL BE SHRA/ISOLD TSRA
THROUGH MID MORNING. COULD SEE BRIEF VSBY REDUCTIONS BUT SHOULD ONLY
BE MVFR BASED ON UPSTREAM OBSERVATIONS AND SINCE SE WIND DIRECTION
IS NOT FAVORABLE FOR ANY ADDITIONAL LIFTING VIA UPSLOPE. EXPECT ALL
TAF SITES TO BE VFR BY EARLY AFTN WITH SCT-BKN MID CLOUDS. MAIN
FRONT AND SFC LOW COME ACROSS UPR MICHIGAN TONIGHT. SCT LINE OF SHRA
AND PERHAPS A TSRA AS WELL WILL SLIDE WEST-TO-EAST LATER IN THE
EVENING THROUGH THE OVERNIGHT HOURS. MODELS VARY ON EXACT DEPICTION
OF RAIN WITH FROPA SO KEPT WITH BROADBRUSHED DEPICTION FOR THE
TIMING OF THE RAIN. POTENTIAL FOR SIGNIFICANT REDUCTION TO CIGS/VSBY
WITH ANY SHOWERS DOES APPEAR REMOTE RIGHT NOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EDT MON APR 2 2012
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EDT MON APR 2 2012
LOW CLOUDS AND SOME FOG WILL AFFECT CMX AND SAW THROUGH MID MORNING.
MAIN IMPACT WILL BE CIGS BLO ALTERNATE AIRPORT MINS BUT BRIEF VSBY
OF LIFR/IFR POSSIBLE AS WELL. PROBLEM AT IWD WILL BE SHRA/ISOLD TSRA
THROUGH MID MORNING. COULD SEE BRIEF VSBY REDUCTIONS BUT SHOULD ONLY
BE MVFR BASED ON UPSTREAM OBSERVATIONS AND SINCE SE WIND DIRECTION
IS NOT FAVORABLE FOR ANY ADDITIONAL LIFTING VIA UPSLOPE. EXPECT ALL
TAF SITES TO BE VFR BY EARLY AFTN WITH SCT-BKN MID CLOUDS. MAIN
FRONT AND SFC LOW COME ACROSS UPR MICHIGAN TONIGHT. SCT LINE OF SHRA
AND PERHAPS A TSRA AS WELL WILL SLIDE WEST-TO-EAST LATER IN THE
EVENING THROUGH THE OVERNIGHT HOURS. MODELS VARY ON EXACT DEPICTION
OF RAIN WITH FROPA SO KEPT WITH BROADBRUSHED DEPICTION FOR THE
TIMING OF THE RAIN. POTENTIAL FOR SIGNIFICANT REDUCTION TO CIGS/VSBY
WITH ANY SHOWERS DOES APPEAR REMOTE RIGHT NOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
515 AM EDT MON APR 2 2012
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 147 AM EDT MON APR 2 2012
ALTHOUGH DRIER AIR IS ADVECTING THRU UPR MI IN THE STEADY E WIND ON
THE SRN FLANK OF HI PRES IN ONTARIO...LINGERING POCKETS OF LO CLDS
OVER ERN UPR MI WARRANT HOLDING ON TO A MENTION OF AT LEAST TEMPO
IFR CIGS THRU SUNRISE AT CMX/SAW...WHERE THE WIND WL HAVE AN UPSLOPE
COMPONENT. WITH A DOWNSLOPE COMPONENT AT IWD...EXPECT ANY LO CLD TO
BREAK UP BEFORE REACHING THAT SITE. WILL HAVE TO WATCH FOR POSSIBLE
ISOLD THUNDERSTORMS CURRENTLY NEAR DLH REACHING INTO IWD BTWN NOW
AND DAYBREAK. WITH THE ONSET OF DAYTIME HEATING...VFR CONDITIONS
SHOULD PREVAIL AFTER ANY LINGERING LO CLDS DISAPPEAR SOON AFTER
SUNRISE. SOME SHRA IN ADVANCE OF A LO PRES TROF APPROACHING FM THE W
MAY IMPACT IWD/CMX LATE THIS AFTN INTO THIS EVNG...BUT LINGERING DRY
AIR IN THE LLVLS INDICATE VFR CONDITIONS SHOULD PERSIST THRU 06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...KC/JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 PM CDT MON APR 2 2012
.DISCUSSION...
SEVERE WEATHER THREAT REMAINS MAIN FOCUS FOR THE EVENING. LATEST
AVAILABLE RUC INDICATING WARM SECTOR TO WORK INTO SOUTH CENTRAL
MINNESOTA THIS EVENING. MLCIN DROP OFF MARKEDLY AS WELL...BUT
BELIEVE CAP WILL HOLD FOR ANY REAL SURFACE BASED CONVECTION.
SHOULD SEE ELEVATED ACTIVITY INITIATE OVER SOUTHWEST MINNESOTA NEAR
REDWOOD FALLS...AND THEN MOVE EAST DURING THE EVENING...AFFECTING
SOUTH CENTRAL MINNESOTA. MOST ALL DETERMINISTIC RUNS INDICATE THIS
AS WELL. VERY STEEP/UNSTABLE MID LEVEL LAPSE RATES IN EXCESS OF
8C/KM WITH ELEVATED CAPE AROUND 1200 J/KG MOVING...SHOULD BE
ENOUGH TO GENERATE THE CONVECTION. HAIL WILL BE THE MAIN THREAT
WITH SOME WIND POSSIBLE AS WELL.
UPPER TROUGH MOVES ACROSS THE CWA OVERNIGHT...AND IS SLOWER THAN
WHAT MODELS WERE SHOWING YESTERDAY. WILL HAVE TO LINGER SOME
SLIGHT CHANCE POPS OVER THE SOUTHERN CWA INTO TUESDAY MORNING...
WITH CLEARING EXPECTED THEREAFTER. COOLER TEMPERATURES EXPECTED
THEN FOR THE NEXT SEVERAL DAYS...BUT STILL RANGING ABOVE NORMAL.
NORTHERLY WINDS WILL INCREASE TONIGHT BEHIND DEPARTING SYSTEM AND
WILL REMAIN BREEZY INTO TUESDAY AS THE COLDER AIR MOVES IN.
WINDS WILL DIMINISH TUESDAY EVENING AND WITH LARGE HIGH PRESSURE DROPPING
SOUTH OVER THE AREA...WILL LIKELY SEE SOME FROST DEVELOP INTO WEDNESDAY
MORNING. PREVIOUS FORECAST HAD THIS MENTIONED AND STILL LOOKS GOOD.
THERE WILL BE ANOTHER OPPORTUNITY FOR FROST...MAINLY OVER WEST
CENTRAL WISCONSIN WEDNESDAY NIGHT/THURSDAY MORNING AS THE HIGH
RETREATS TO THE EAST.
LONG RANGE MODELS CONTINUE TO TREND ANOTHER WAVE ACROSS THE AREA
LATER FRIDAY NIGHT INTO SATURDAY SATURDAY NIGHT TIME FRAME. EVEN
COLDER AIR TO FOLLOW THIS FRONT...POSSIBLE MAKING TEMPERATURES
CLOSER TO NORMAL FOR THIS TIME OF THE YEAR.
&&
.AVIATION.../18Z TAF ISSUANCE/
SFC LOW PRESSURE OVER SE SD WILL SHIFT ENE OVER SRN MN INTO WRN WI
THROUGH TONIGHT...DRAGGING A CDFNT WITH IT. LOW CLOUDS ARE
CONTINUING TO ERODE OVER SW AND W MN WHILE CENTRAL AND ERN MN INTO
WRN WI ARE DEALING WITH SCT COVERAGE OF HIGHER CLOUDS. GUSTY SE
WINDS WILL PERSIST THROUGH THIS EVENING THEN SETTLE DOWN A BIT
OVERNIGHT...BUT NOT EXPECTING MUCH BELOW 10 KT. AS THE SFC LOW
SHIFTS E...CHCS INCREASE FOR SHWRS WITH A FEW ISOLD TSTMS. BETTER
PROSPECTS FOR THUNDER OVER NRN MN AND IA...BUT ISOLD TS CANNOT BE
RULED OUT FOR ANY OF THE TAF SITES. THAT SAID...EVEN THE SHORT-
TERM MODELS ARE SHOWING DIFFERING SCENARIOS AS TO THE
LOCATION/TIMING OF THUNDER. HAVE TWEAKED THE TIMING OF THE TEMPO
GROUPS AT EACH SITE TO REFLECT BEST TIMING OF PRECIP BUT HAVE ONLY
USED MENTION OF CB TO INDICATE CONVECTION. FELT THIS WAS THE
BETTER WAY TO GO RATHER THAN TRYING TO PIN DOWN TS WITH LOW
CONFIDENCE. ONCE THE PRECIP CEASES DURING THE EARLY MRNG HOURS...
MVFR CIGS WILL LINGER THROUGH DAYBREAK. INCREASED LOW LEVEL
JETTING WILL PREVENT CIGS FROM GETTING DOWN TO IFR LEVELS OR
HAVING ANY SIGNIFICANT FOG DEVELOPING...BUT THERE SHOULD BE SOME
PERIODS OF MVFR VSBYS AFTER THE RAIN ENDS. AS THE LOW SHIFTS E AND
HIGH PRESSURE SLOWLY ENTERS FROM THE NW TMRW...CLOUDS WILL LIFT
AND SCATTER OUT...LEADING TO VFR CONDS BY MIDDAY TMRW. WINDS WILL
ALSO INCREASE AND BECOME GUSTY AGAIN AS THE PRESSURE GRADIENT
TIGHTENS WITH THE INCOMING HIGH PRESSURE.
MSP...VFR CONDS EXPECTED TO PREVAIL THROUGH THIS EVENING THOUGH
THERE MAY BE SOME BOUNCING BETWEEN SCT AND BKN COVERAGE WITH BASES
ARND 4000 FT. COVERAGE BECOMES DECIDEDLY BKN LATE THIS EVE AS THE
FRONTAL SYSTEM APPROACHES. BEST TIMING FOR PRECIP ONSET LOOKS TO
BE AROUND 06Z THEN CONTINUING TO SHORTLY BEFORE DAYBREAK. AM NOT
LOOKING FOR A PROLONGED DURATION OF PRECIP SINCE THIS IS MORE OF A
CONVECTIVELY-BASED EVENT RATHER THAN STRATIFORM...BUT ALTHOUGH MSP
TAF ADVERTISES NO PRECIP AFTER 10Z...SOME SHOWERS GOING INTO
SUNRISE CANNOT BE RULED OUT. THUNDER CHCS ARE RATHER LOW BUT WITH
ISOLD TSTMS POSSIBLE...CB MENTION LOOKS TO COVER THINGS.
CONDITIONS IMPROVE LATE MRNG INTO THE EARLY AFTN HOURS...BECOMING
VFR BY EARLY AFTN. GUSTY CONDITIONS THIS AFTN SETTLE DOWN A BIT
OVERNIGHT THEN RETURN TMRW WITH THE INCOMING HIGH PRESSURE.
OUTLOOK...
/TUE NIGHT-FRI/...VFR AS HIGH PRESSURE MOVES ACROSS.
/SAT-SUN/...POSSIBLE FRONTAL SYSTEM MOVES OVER THE NORTHERN PLAINS
INTO THE UPPER MISSISSIPPI RIVER VALLEY. MVFR CONDS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/JPC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1244 PM CDT MON APR 2 2012
.AVIATION...04/02/18Z ISSUANCE...
VFR IN BROKEN CLOUDS...WITH AREAS OF SCATTERED CLOUDS ACROSS
NORTHWEST WISCONSIN. ISOLATED INTENSE THUNDERSTORMS WITH HAIL...
JUST SOUTH OF INL...SHOULD SLOWLY WEAKEN AND PASS NORTHEAST INTO
CANADA NEAR RAINY LAKE LATE THIS AFTERNOON. SCATTERED MVFR IN
SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP OVER OUR AREA...WEST
OF A CENTRAL LAKE SUPERIOR TROUGH...THIS EVENING. VFR AND CLEARING
WILL SPREAD TOWARD THE SOUTHEAST BEGINNING IN NORTHEAST MINNESOTA
EARLY TUESDAY AND CONTINUING THROUGH NORTHWEST WISCONSIN AROUND
MIDDAY TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 1027 AM CDT MON APR 2 2012/
UPDATE...
THE 12Z NAM AND 09Z SREF ARE REASONABLE IN THE PLACEMENT OF THE
CURRENT BAND OF ELEVATED THUNDERSTORMS STRETCHING FROM NEAR BIG
FORK TO CRANE LAKE IN THE NORTHWESTERN FA. THEREFORE...MADE
UPDATES TO POPS/WEATHER THROUGH THIS AFTERNOON THAT LEANED ON THE
NAM/SREF WHICH FOCUSES PCPN ACROSS THE NORTHERN AND WESTERN FA.
DOWNPLAYED THE EMPHASIS ON THE CHANCES OF THUNDER TO GIVE GREATER
EMPHASIS ON RAIN SHOWERS SINCE MODEL INDICES AND INSTABILITY DO
NOT APPEAR FAVORABLE FOR CONVECTION. AT THIS TIME...THE SPC
MESOANALYSIS PAGE INDICATES UP TO 5OO J/KG OF ELEVATED CAPE BY
THAT BAND OF THUNDERSTORMS...AND MOST UNSTABLE LIFTED INDICES
AROUND -2 TO -5. THERE HAVE BEEN SOME REPORTS OF MINOR HAIL WITH
THESE STORMS...AND THIS TREND OF PULSING STORMS WITH SMALL HAIL
WILL LIKELY CONTINUE FOR AT LEAST THE NEAR FUTURE. WHILE THE
UPDATES PULLED SOME EMPHASIS OF PCPN FROM THE SOUTHERN FA...WILL
NEED TO KEEP AN EYE ON A BOUNDARY STRETCHING FROM ABOUT HINCKLEY
TO NORTHERN CASS COUNTY THAT IS MOVING TO THE SOUTHWEST. SINCE
THERE IS GREATER INSTABILITY ACROSS THE SOUTHWESTERN FA...WILL
NEED TO SEE IF THIS BOUNDARY BECOMES A TRIGGER FOR STORMS. ONLY
MADE MINOR CHANGES TO THE TEMPERATURES AND WINDS.
PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 30 60 10 0
INL 52 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 63 42 61 33 / 10 60 20 0
ASX 58 41 57 34 / 30 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....EOM
AVIATION...EOM
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1027 AM CDT MON APR 2 2012
.UPDATE...
THE 12Z NAM AND 09Z SREF ARE REASONABLE IN THE PLACEMENT OF THE
CURRENT BAND OF ELEVATED THUNDERSTORMS STRETCHING FROM NEAR BIG
FORK TO CRANE LAKE IN THE NORTHWESTERN FA. THEREFORE...MADE
UPDATES TO POPS/WEATHER THROUGH THIS AFTERNOON THAT LEANED ON THE
NAM/SREF WHICH FOCUSES PCPN ACROSS THE NORTHERN AND WESTERN FA.
DOWNPLAYED THE EMPHASIS ON THE CHANCES OF THUNDER TO GIVE GREATER
EMPHASIS ON RAIN SHOWERS SINCE MODEL INDICES AND INSTABILITY DO
NOT APPEAR FAVORABLE FOR CONVECTION. AT THIS TIME...THE SPC
MESOANALYSIS PAGE INDICATES UP TO 5OO J/KG OF ELEVATED CAPE BY
THAT BAND OF THUNDERSTORMS...AND MOST UNSTABLE LIFTED INDICES
AROUND -2 TO -5. THERE HAVE BEEN SOME REPORTS OF MINOR HAIL WITH
THESE STORMS...AND THIS TREND OF PULSING STORMS WITH SMALL HAIL
WILL LIKELY CONTINUE FOR AT LEAST THE NEAR FUTURE. WHILE THE
UPDATES PULLED SOME EMPHASIS OF PCPN FROM THE SOUTHERN FA...WILL
NEED TO KEEP AN EYE ON A BOUNDARY STRETCHING FROM ABOUT HINCKLEY
TO NORTHERN CASS COUNTY THAT IS MOVING TO THE SOUTHWEST. SINCE
THERE IS GREATER INSTABILITY ACROSS THE SOUTHWESTERN FA...WILL
NEED TO SEE IF THIS BOUNDARY BECOMES A TRIGGER FOR STORMS. ONLY
MADE MINOR CHANGES TO THE TEMPERATURES AND WINDS.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT MON APR 2 2012/
AVIATION...12Z TAFS.
BKN MID DECK DEVELOPING OVER NE MN AND NW WI WILL AFFECT THE TAF
SITES THROUGH THIS FORECAST CYCLE. SHOWERS FROM THE MN ARROWHEAD
INTO NW WI TO MOVE E AND DISSIPATE. SFC TROF IN THE RED RIVER
VALLEY WILL MOVE INTO THE FA ALONG WITH MID LEVEL INSTABILITY AXIS.
SOME SHOWERS MAY FORM BY 15Z NEAR KINL...HOLDING OFF UNTIL LATER
THIS AFTERNOON NEAR KHIB/KBRD. INSTABILITY AXIS ALIGNS ITSELF OVER
THE AREA BETWEEN 18Z-21Z AND ALONG WITH THE SFC TROF WILL BE THE
FOCUS FOR THUNDERSTORMS. USED VCTS AT KBRD/KHYR AS TIMING OF
STORMS IS IN QUESTION AND CONFIDENCE IS LOW. PCPN WILL DIMINISH
FROM NW TO SE THIS EVENING WITH LOSS OF SOLAR/INSTABILITY.
PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 30 60 10 0
INL 52 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 63 42 61 33 / 10 60 20 0
ASX 58 41 57 34 / 30 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....EOM
AREA FORECAST DISCUSSION
NWS DULUTH MN
641 AM CDT MON APR 2 2012
.AVIATION...12Z TAFS.
BKN MID DECK DEVELOPING OVER NE MN AND NW WI WILL AFFECT THE TAF
SITES THROUGH THIS FORECAST CYCLE. SHOWERS FROM THE MN ARROWHEAD
INTO NW WI TO MOVE E AND DISSIPATE. SFC TROF IN THE RED RIVER
VALLEY WILL MOVE INTO THE FA ALONG WITH MID LEVEL INSTABILITY AXIS.
SOME SHOWERS MAY FORM BY 15Z NEAR KINL...HOLDING OFF UNTIL LATER
THIS AFTERNOON NEAR KHIB/KBRD. INSTABILITY AXIS ALIGNS ITSELF OVER
THE AREA BETWEEN 18Z-21Z AND ALONG WITH THE SFC TROF WILL BE THE
FOCUS FOR THUNDERSTORMS. USED VCTS AT KBRD/KHYR AS TIMING OF
STORMS IS IN QUESTION AND CONFIDENCE IS LOW. PCPN WILL DIMINISH
FROM NW TO SE THIS EVENING WITH LOSS OF SOLAR/INSTABILITY.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
AVIATION...06Z TAFS
IFR/MVFR CEILINGS WILL OCCUR IN SPOTS THROUGH THE PERIOD...MOST LIKELY
AROUND LAKE SUPERIOR. SOME FOG WILL ALSO BE POSSIBLE...ALTHOUGH
SB`S HAVE INCREASED IN MOST AREAS DUE TO STRONG HIGH BUILDING
SOUTH THROUGH ONTARIO.
SHOWERS/STORMS WERE DEVELOPING JUST WEST OF KDLH...ON WEST TO NEAR
KDTL. PERSISTENT WAA/MOISTURE TRANSPORT SHOULD LEAD TO ADDITIONAL
SHOWER/STORM DEVELOPMENT OVERNIGHT INTO MONDAY. MVFR OR EVEN SOME
IFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWERS/STORMS. STORMS
SHOULD OCCUR MAINLY OVER NORTHEAST/NORTHERN MINNESOTA THROUGH
MUCH OF MONDAY...TRANSLATING EAST MONDAY NIGHT.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 40 60 10 0
INL 51 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 62 42 61 33 / 20 60 20 0
ASX 57 41 57 34 / 50 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...CANNON
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT MON APR 2 2012
.SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
.EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
AVIATION...06Z TAFS
IFR/MVFR CEILINGS WILL OCCUR IN SPOTS THROUGH THE PERIOD...MOST LIKELY
AROUND LAKE SUPERIOR. SOME FOG WILL ALSO BE POSSIBLE...ALTHOUGH
SB`S HAVE INCREASED IN MOST AREAS DUE TO STRONG HIGH BUILDING
SOUTH THROUGH ONTARIO.
SHOWERS/STORMS WERE DEVELOPING JUST WEST OF KDLH...ON WEST TO NEAR
KDTL. PERSISTENT WAA/MOISTURE TRANSPORT SHOULD LEAD TO ADDITIONAL
SHOWER/STORM DEVELOPMENT OVERNIGHT INTO MONDAY. MVFR OR EVEN SOME
IFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWERS/STORMS. STORMS
SHOULD OCCUR MAINLY OVER NORTHEAST/NORTHERN MINNESOTA THROUGH
MUCH OF MONDAY...TRANSLATING EAST MONDAY NIGHT.
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 60 60 10 0
INL 51 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 50 60 10 0
HYR 62 42 61 33 / 20 60 20 0
ASX 57 41 57 34 / 60 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...CANNON
LONG TERM....GSF
AREA FORECAST DISCUSSION
NWS JACKSON MS
457 PM CDT MON APR 2 2012
.UPDATE...HAVE EXPANDED THE AREAL COVERAGE OF SVR WATCH 128 TO
INCLUDE THE AREA FROM GRENADA TO KEMPER AND POINTS SWWD AS THE LINE
OF SEVERE STORMS CONTINUES TO TRACK TO THE NE THIS EVENING.
LOCATIONS IN THE EXPANDED AREA ARE IN A REGION OF PRESSURE FALLS AND
-4 TO -5 LIFTED INDICES. ALSO CLEARED A FEW COUNTIES FROM THE WATCH
OVER SWRN ZONES IN THE STRATIFORM RAIN SHIELD BEHIND THE LINE.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...COMPLICATED FORECAST
IN THE SHORT TERM AS SEVERAL POTENTIAL ROUNDS OF STORMS WILL BE
POSSIBLE OVER THE NEXT FEW DAYS.
CURRENT RADARS SHOW BROKEN LINE OF SHOWERS AND THUNDERSTORMS MOVING
NORTHWARD THROUGH THE CWA...GENERALLY FROM BASTROP TO THE JACKSON
METRO AREA TO JUST NORTH OF HATTIESBURG. THERE ARE ALSO SOME STORMS
BEHIND THIS LINE MOVING NORTH FROM PIKE AND AMITE COUNTIES IN
LOUISIANA. THIS MAIN LINE IS PRODUCING SEVERE WIND DAMAGE WITH MOST
REPORTS BEING TREES COMING DOWN AND SOME QUARTER SIZE HAIL AS IT
CONTINUES NORTH THROUGH AN UNSTABLE ATMOSPHERE CHARACTERIZED BY
3500-4000 J/KG SBCAPE...2000-2600 J/KG MLCAPE...28-29C VERTICAL
TOTALS...AND -8 TO -12 SFC LI PER RUC ANALYSIS. THIS UNSTABLE
AIRMASS HAS HELPED TO SUSTAIN THE SEVERITY OF THE LINE OF STORMS AS
IT MOVED OUT OF THE LAKE CHARLES LOUISIANA AREA EARLIER THIS
MORNING. THIS LINE IS EXPECTED TO REMAIN SEVERE AS IT CONTINUES TO
THE NORTH AND EAST UNTIL DAYTIME HEATING IS ABLE TO REDUCE
INSTABILITY OVER THE AREA. SEVERE THUNDERSTORM WATCH CONTINUES FOR
PORTIONS OF THE AREA...AND WAS EVEN EXPANDED TO INCLUDE MORE OF THE
PINE BELT REGION THROUGH 8PM.
HI-RES WRF MODELS AS WELL AS GLOBAL MODELS INDICATE THAT THIS
ACTIVITY WILL BE WANING THROUGH THE EVENING AND OVERNIGHT AS
INSTABILITY WANES AND THE SHORTWAVE TROUGH LIFTS OFF TO THE NORTH.
THERE IS SOME POTENTIAL FOR PATCHY FOG TONIGHT SOUTH OF I-20 AS
MOISTURE CONTINUES TO BUILD INTO THE REGION AND WINDS DIMINISH LATER
IN THE NIGHT.
FOR TUESDAY...THERE REMAINS SOME UNCERTAINTY AS TO HOW STORMS WILL
EVOLVE. MODELS SHOW SHORTWAVE RIDGING MOVING INTO THE AREA...WHICH
SHOULD SUPPRESS MOST CONVECTION. IN ADDITION...THERE IS SOME CONCERN
AS TO HOW THE SYSTEM GOING THROUGH TODAY WILL POTENTIALLY AFFECT
TOMORROW. THERE WILL BE ENOUGH INSTABILITY AS TEMPERATURES REACH
INTO THE 80S ONCE AGAIN. MUCAPE VALUES ARE PROGGED TO BE AROUND
1800-2000J/KG...28-29C VERTICAL TOTALS...BUT WIND SHEAR WILL AGAIN
BE RATHER WEAK AS WELL AS MID LEVEL FLOW. WHATEVER BOUNDARIES THIS
SYSTEM TODAY LEAVES AROUND COULD BE A FOCUS FOR ANY ADDITIONAL
SHOWERS AND THUNDERSTORMS TOMORROW. GIVEN THE WEAK FLOW...THESE
STORMS WOULD BE OF PULSE TYPE VARIETY. HAVE GONE WITH SLIGHT CHANCE
POPS FOR TOMORROW GIVEN UNCERTAINTY IN STORM COVERAGE.
THE BETTER POTENTIAL FOR SHOWERS AND STORMS STILL LOOKS TO BE ON
WEDNESDAY. THERE STILL REMAINS UNCERTAINTY IN TIMING AND HOW MUCH
COVERAGE WE WILL SEE. HOWEVER...PARAMETERS LOOK BETTER IN TERMS OF
WIND SHEAR...MID LEVEL FLOW...LAPSE RATES THAN THEY HAVE FOR THE
PREVIOUS DAYS. WHILE VALUES OF SHEAR ARE STILL NOT OVERLY IMPRESSIVE
WHICH COULD PRECLUDE ORGANIZED THUNDERSTORM ACTIVITY...GIVEN THE
FORCING AND LIFT FROM THE UPPER LOW TRACKING CLOSER...WE COULD SEE
ADDITIONAL STRONG TO SEVERE STORMS AND WILL CONTINUE TO MENTION THIS
IN THE HWO/GRAPHICS. THE BEST LIFT SHOULD CONTINUE TO MOVE EAST OF
THE AREA BY THURSDAY MORNING...AND END MOST OF THE THUNDERSTORM
ACTIVITY. /28/
.LONG TERM...THURSDAY THROUGH MONDAY...DEPENDING ON THE
TRACK OF THE MID LEVEL LOW...THERE COULD BE ENOUGH
INSTABILITY THURSDAY INTO THURSDAY NIGHT TO GET REDEVELOPMENT OF
MOSTLY DIURNAL SHOWER/ISOLATED THUNDERSTORM ACTIVITY...PARTICULARLY
OVER NE PORTIONS OF THE FORECAST AREA. OTHERWISE...IN THE WAKE OF
THE DEPARTING LOW...EXPECT THE STUBBORN MID LEVEL RIDGE TO REBUILD
OVER THE FORECAST AREA AS WE GO INTO NEXT WEEKEND RESULTING IN MORE
WARM AND DRY CONDITIONS. /EC/
&&
.AVIATION...VFR CONDITIONS ONGOING THIS AFTERNOON BUT SHOWERS AND
THUNDERSTORMS MOVING NORTH THROUGH THE AREA BRINGING LOCALIZED MVFR
TO IFR CONDITIONS FOR LOW CEILINGS AND VIS. THESE STORMS BRINGING
GUSTY WINDS UP TO 60 MPH AND POTENTIAL FOR LARGE HAIL TO GOLFBALL
SIZE. THE RISK FOR THUNDERSTORMS AND RAIN WILL WANE THROUGH THE
EVENING AFTER 01-02Z. AREAS OF MVFR/IFR STRATUS/FOG WILL REDEVELOP
AGAIN LATE TONIGHT INTO EARLY TUESDAY MORNING BEFORE DISSIPATING
AFTER ABOUT 15Z TUESDAY. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 62 85 65 82 / 51 20 22 55
MERIDIAN 61 87 61 81 / 43 23 12 46
VICKSBURG 62 86 64 82 / 40 16 33 58
HATTIESBURG 64 88 65 83 / 41 17 18 50
NATCHEZ 64 85 66 83 / 21 16 38 63
GREENVILLE 64 85 65 85 / 51 17 44 55
GREENWOOD 65 85 66 84 / 46 23 36 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/EC/03
AREA FORECAST DISCUSSION
NWS JACKSON MS
410 PM CDT MON APR 2 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...COMPLICATED FORECAST
IN THE SHORT TERM AS SEVERAL POTENTIAL ROUNDS OF STORMS WILL BE
POSSIBLE OVER THE NEXT FEW DAYS.
CURRENT RADARS SHOW BROKEN LINE OF SHOWERS AND THUNDERSTORMS MOVING
NORTHWARD THROUGH THE CWA...GENERALLY FROM BASTROP TO THE JACKSON
METRO AREA TO JUST NORTH OF HATTIESBURG. THERE ARE ALSO SOME STORMS
BEHIND THIS LINE MOVING NORTH FROM PIKE AND AMITE COUNTIES IN
LOUISIANA. THIS MAIN LINE IS PRODUCING SEVERE WIND DAMAGE WITH MOST
REPORTS BEING TREES COMING DOWN AND SOME QUARTER SIZE HAIL AS IT
CONTINUES NORTH THROUGH AN UNSTABLE ATMOSPHERE CHARACTERIZED BY
3500-4000 J/KG SBCAPE...2000-2600 J/KG MLCAPE...28-29C VERTICAL
TOTALS...AND -8 TO -12 SFC LI PER RUC ANALYSIS. THIS UNSTABLE
AIRMASS HAS HELPED TO SUSTAIN THE SEVERITY OF THE LINE OF STORMS AS
IT MOVED OUT OF THE LAKE CHARLES LOUISIANA AREA EARLIER THIS
MORNING. THIS LINE IS EXPECTED TO REMAIN SEVERE AS IT CONTINUES TO
THE NORTH AND EAST UNTIL DAYTIME HEATING IS ABLE TO REDUCE
INSTABILITY OVER THE AREA. SEVERE THUNDERSTORM WATCH CONTINUES FOR
PORTIONS OF THE AREA...AND WAS EVEN EXPANDED TO INCLUDE MORE OF THE
PINE BELT REGION THROUGH 8PM.
HI-RES WRF MODELS AS WELL AS GLOBAL MODELS INDICATE THAT THIS
ACTIVITY WILL BE WANING THROUGH THE EVENING AND OVERNIGHT AS
INSTABILITY WANES AND THE SHORTWAVE TROUGH LIFTS OFF TO THE NORTH.
THERE IS SOME POTENTIAL FOR PATCHY FOG TONIGHT SOUTH OF I-20 AS
MOISTURE CONTINUES TO BUILD INTO THE REGION AND WINDS DIMINISH LATER
IN THE NIGHT.
FOR TUESDAY...THERE REMAINS SOME UNCERTAINTY AS TO HOW STORMS WILL
EVOLVE. MODELS SHOW SHORTWAVE RIDGING MOVING INTO THE AREA...WHICH
SHOULD SUPPRESS MOST CONVECTION. IN ADDITION...THERE IS SOME CONCERN
AS TO HOW THE SYSTEM GOING THROUGH TODAY WILL POTENTIALLY AFFECT
TOMORROW. THERE WILL BE ENOUGH INSTABILITY AS TEMPERATURES REACH
INTO THE 80S ONCE AGAIN. MUCAPE VALUES ARE PROGGED TO BE AROUND
1800-2000J/KG...28-29C VERTICAL TOTALS...BUT WIND SHEAR WILL AGAIN
BE RATHER WEAK AS WELL AS MID LEVEL FLOW. WHATEVER BOUNDARIES THIS
SYSTEM TODAY LEAVES AROUND COULD BE A FOCUS FOR ANY ADDITIONAL
SHOWERS AND THUNDERSTORMS TOMORROW. GIVEN THE WEAK FLOW...THESE
STORMS WOULD BE OF PULSE TYPE VARIETY. HAVE GONE WITH SLIGHT CHANCE
POPS FOR TOMORROW GIVEN UNCERTAINTY IN STORM COVERAGE.
THE BETTER POTENTIAL FOR SHOWERS AND STORMS STILL LOOKS TO BE ON
WEDNESDAY. THERE STILL REMAINS UNCERTAINTY IN TIMING AND HOW MUCH
COVERAGE WE WILL SEE. HOWEVER...PARAMETERS LOOK BETTER IN TERMS OF
WIND SHEAR...MID LEVEL FLOW...LAPSE RATES THAN THEY HAVE FOR THE
PREVIOUS DAYS. WHILE VALUES OF SHEAR ARE STILL NOT OVERLY IMPRESSIVE
WHICH COULD PRECLUDE ORGANIZED THUNDERSTORM ACTIVITY...GIVEN THE
FORCING AND LIFT FROM THE UPPER LOW TRACKING CLOSER...WE COULD SEE
ADDITIONAL STRONG TO SEVERE STORMS AND WILL CONTINUE TO MENTION THIS
IN THE HWO/GRAPHICS. THE BEST LIFT SHOULD CONTINUE TO MOVE EAST OF
THE AREA BY THURSDAY MORNING...AND END MOST OF THE THUNDERSTORM
ACTIVITY. /28/
.LONG TERM...THURSDAY THROUGH MONDAY...DEPENDING ON THE
TRACK OF THE MID LEVEL LOW...THERE COULD BE ENOUGH
INSTABILITY THURSDAY INTO THURSDAY NIGHT TO GET REDEVELOPMENT OF
MOSTLY DIURNAL SHOWER/ISOLATED THUNDERSTORM ACTIVITY...PARTICULARLY
OVER NE PORTIONS OF THE FORECAST AREA. OTHERWISE...IN THE WAKE OF
THE DEPARTING LOW...EXPECT THE STUBBORN MID LEVEL RIDGE TO REBUILD
OVER THE FORECAST AREA AS WE GO INTO NEXT WEEKEND RESULTING IN MORE
WARM AND DRY CONDITIONS. /EC/
&&
.AVIATION...VFR CONDITIONS ONGOING THIS AFTERNOON BUT SHOWERS AND
THUNDERSTORMS MOVING NORTH THROUGH THE AREA BRINGING LOCALIZED MVFR
TO IFR CONDITIONS FOR LOW CEILINGS AND VIS. THESE STORMS BRINGING
GUSTY WINDS UP TO 60 MPH AND POTENTIAL FOR LARGE HAIL TO GOLFBALL
SIZE. THE RISK FOR THUNDERSTORMS AND RAIN WILL WANE THROUGH THE
EVENING AFTER 01-02Z. AREAS OF MVFR/IFR STRATUS/FOG WILL REDEVELOP
AGAIN LATE TONIGHT INTO EARLY TUESDAY MORNING BEFORE DISSIPATING
AFTER ABOUT 15Z TUESDAY. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 62 85 65 82 / 51 20 22 55
MERIDIAN 61 87 61 81 / 43 23 12 46
VICKSBURG 62 86 64 82 / 40 16 33 58
HATTIESBURG 64 88 65 83 / 41 17 18 50
NATCHEZ 64 85 66 83 / 21 16 38 63
GREENVILLE 64 85 65 85 / 51 17 44 55
GREENWOOD 65 85 66 84 / 46 23 36 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/EC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
345 AM CDT MON APR 2 2012
.SHORT TERM...
ISSUED AT 341 AM CDT MON APR 2 2012
(TODAY)
MAIN QUESTION FOR TODAY WILL BE HOW WARM WILL IT GET. CURRENTLY
HAVE A BACKDOOR COLD FRONT STALLED OUT OVER FORECAST AREA. IT
EXTENDS FROM NORTHWESTERN MO THROUGH MEXICO MO THEN EASTWARD INTO
SOUTHERN IL...JUST NORTH OF ST. LOUIS METRO AREA. BELIEVE IT WILL
SLOWLY WEAKEN AND WASH OUT OVER TIME TODAY...WITH WINDS PICKING UP
FROM THE SOUTH. SO TEMPS TO WARM UP INTO THE MID TO UPPER
80S...SIMILAR TO YESTERDAY WITH RECORD OR NEAR RECORD HIGHS. IF AIR
MASS RECOVERS FASTER THAN CURRENT THINKING...COULD SEE TEMPS WARM
UP INTO THE LOWER 90S. AS FOR ANY CLOUD COVER...SHOULD BE A MOSTLY
SUNNY DAY...WITH PERHAPS A FEW MORE CLOUDS OVER NORTHEASTERN
PORTIONS OF FORECAST AREA...CLOSER TO BACKDOOR COLD FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 345 AM CDT MON APR 2 2012
(TONIGHT THROUGH SUNDAY)
A LONGWAVE UPPER RIDGE WILL CONTINUE TO PERSIST OUR REGION INTO NEXT
WEEKEND. NORMALLY THIS PATTERN WOULD FORETELL MAINLY DRY WX AND
ABOVE AVERAGE TEMPS...BUT A STRONG STORM SYSTEM OVER THE SWRN CONUS
THAT IS IN THE PROCESS OF GETTING CUTOFF FROM THE MAIN FLOW WILL
FOIL MUCH OF THAT FOR MID AND LATE WEEK WITH WHAT SHOULD BE A WET
PERIOD WITH TEMPS CLOSER TO AVERAGE FOR THIS TIME OF YEAR. WHILE AN
ARGUMENT CAN BE MADE THAT MUCH ABOVE AVERAGE TEMPS HAVE BECOME THE
NEW NORMAL RECENTLY...AVERAGE TEMPS WERE LAST SEEN IN OUR AREA ABOUT
FOUR WEEKS AGO...SO COULD BE A MOMENTUS OCCASION.
IN THE MEANTIME...TONIGHT IS LOOKING INCREASINGLY DRY AND CLEAR AS
FRONT IS FURTHER DELAYED FROM THE NW AND WHAT SHOULD BE A DORMANT
LEAD IMPULSE SHOULD FALL SHORT OF THE SWRN FA BY 12Z/TUES. TUESDAY
TRENDS REMAIN SIMILAR TO BEFORE...AS LEAD IMPULSE TRACKS THRU MAINLY
SERN MO AND SRN IL SHOULD SPAWN NUMEROUS TSRA DURING THE HEATING OF
THE DAY IN A REGIME THAT CONSISTS OF A VERY MOIST AND MODERATELY
UNSTABLE ATMOSPHERE WITH NO CAP. FRONT EDGING INTO NRN MO AND CNTRL
IL SHOULD ALSO BE ABLE TO RESULT IN SCT CONVECTION. VORT MAX DRIVEN
ACTIVITY WILL DIMINISH/EXIT TO THE E-SE TUESDAY EVENING WHILE
ACTIVITY ALONG THE FRONT TO THE N WILL ALSO RECEDE. TUESDAY NIGHT
OTHERWISE DID LOOK LIKE A PERIOD OF DOWNTIME FROM PCPN...BUT LATEST
MODELS INDICATE THE INITIAL BAND OF SHRA/TSRA FROM MAIN CUTOFF LO TO
THE W WILL EDGE THE SWRN FA. TUESDAY TEMPS HAVE BEEN BUMPED UP
SIGNFICANTLY WITH FRONT MUCH DELAYED AND ENOUGH SUN BEFORE BETTER
TSRA CHCS LATER IN THE AFTN...TO RESULT IN WIDESPREAD TEMPS IN THE
80-85 RANGE...REFLECTING THE EARLIER TRENDS OF THE MAV MOS.
WEDNESDAY THRU THURSDAY LOOKS TO BE THE BEST CHC FOR WIDESPREAD
PCPN...WITH TEMPS BACKING OFF TOWARDS AVERAGE BY THURSDAY...AND
PROBABLY AGAIN ON FRIDAY WITH LEFTOVER CLOUDS AND BUILDING CANADIAN
HI PRES FROM THE NE.
ONCE THE CUTOFF SYSTEM EXITS OUR REGION...LONGWAVE RIDGE WILL
RE-ASSUME ITS DOMINANCE AND EVEN DEFLECT A SHORTWAVE TO OUR N FOR
NEXT WEEKEND. HOWEVER...SFC FRONTAL BOUNDARY EXPECTED TO SETTLE IN
DURING NEXT WEEKEND COULD RESULT IN EXTENDED RAIN CHCS AGAIN. 30PCT
IS CLIMO FOR THIS TIME OF YEAR...AND WITH FRONTAL BOUNDARY INVOF OUR
REGION...HAVE 30-40PCT GOING FOR BOTH SATURDAY AND SUNDAY.
TES
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...STILL CONCERNED THAT THERE COULD BE SOME
STRATUS DEVELOPMENT AFTER 09Z OVER THE OZARKS AND SPREADING NORTH
INTO THE VICINITY OF LAMBERT FIELD BEFORE SUNRISE. BASICALLY
NOTHING HAS CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT
STRATUS AND OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS
TIME AND KEEP SCATTERED 1200FT IN AT LAMBERT. OTHERWISE...EXPECT
LIGHT AND VARIABLE SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR
THE REST OF THE NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST
AGAIN MONDAY WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 345 AM CDT MON APR 2 2012
RECORD MAX AND HI MIN TEMPS FOR TODAY
SAINT LOUIS (KSTL) 88/1946 68/1946
COLUMBIA (KCOU) 85/1946 65/1956
QUINCY (KUIN) 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 AM CDT MON APR 2 2012
.SHORT TERM...
ISSUED AT 341 AM CDT MON APR 2 2012 (TODAY)
MAIN QUESTION FOR TODAY WILL BE HOW WARM WILL IT GET. CURRENTLY
HAVE A BACKDOOR COLD FRONT STALLED OUT OVER FORECAST AREA. IT
EXTENDS FROM NORTHWESTERN MO THROUGH MEXICO MO THEN EASTWARD INTO
SOUTHERN IL...JUST NORTH OF ST. LOUIS METRO AREA. BELIEVE IT WILL
SLOWLY WEAKEN AND WASH OUT OVER TIME TODAY...WITH WINDS PICKING UP
FROM THE SOUTH. SO TEMPS TO WARM UP INTO THE MID TO UPPER
80S...SIMILAR TO YESTERDAY WITH RECORD OR NEAR RECORD HIGHS. IF AIR
MASS RECOVERS FASTER THAN CURRENT THINKING...COULD SEE TEMPS WARM
UP INTO THE LOWER 90S. AS FOR ANY CLOUD COVER...SHOULD BE A MOSTLY
SUNNY DAY...WITH PERHAPS A FEW MORE CLOUDS OVER NORTHEASTERN
PORTIONS OF FORECAST AREA...CLOSER TO BACKDOOR COLD FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(MONDAY THROUGH NEXT SUNDAY)
TOMORROW STILL LOOKS THAT IT WILL BE AS WARM AS TODAY IF NOT A BIT
WARMER WITH RECORD OR NEAR RECORD HIGHS. CURRENT (3 PM) TEMPS ARE
IN THE MID TO UPPER 80S. LOWS TOMORROW MORNING OVER MUCH OF THE AREA
ARE EXPECTED TO BE ABOUT 3-6 DEGREES WARMER THAN THIS MORNING.
FORECAST SOUNDINGS STILL INDICATE THAT WE SHOULD MIX UP TO AROUND
850MB WHERE TEMPERATURES WILL BE 18-21C RANGE. ANY CLOUDS AROUND IN
THE MORNING SHOULD THIN OUT BY LATE MORNING ALLOWING MAINLY SUNNY
SKIES. THIS SUPPORTS TEMPERATURES IN THE UPPER 80S TO AROUND
90...ESPECIALLY FROM THE ST. METRO AREA WESTWARD WHERE A SOUTH
SOUTHWESTERLY WINDS WILL FAVOR SLIGHTLY WARMER TEMPERATURES IN THE
LEE OF THE OZARKS.
RAIN CHANCES STILL LOOK TO BE SUPPRESSED THROUGH MONDAY NIGHT WITH
AN UPPER RIDGE OVER THE AREA. HAVE LEANED TOWARD THE ECMWF FOR MOST
OF THE FORECAST AS IT HAS BEEN THE MOST CONSISTENT WITH THE
PLACEMENT OF THE UPPER LOW AND THE DEPICTION OF THE SURFACE FRONT
THAT WILL MOVE ACROSS THE AREA ON TUESDAY. THE 500MB TROUGH THAT
THE GFS IS BRINGING INTO EASTERN MO ON TUESDAY LOOKS TO BE OVERLY
INFLUENCED BY CONVECTIVE FEEDBACK. WITH THIS IN MIND...HAVE KEPT
LIKELY POPS OVER THE SOUTHERN CWA ON TUESDAY AFTERNOON WHERE THE
FRONT WILL BE DURING THE MOST UNSTABLE TIME OF THE DAY. I THEN KEEP
CHANCES OF STORMS OVER SOUTHEASTERN MO INTO SOUTHERN IL ON TUESDAY
NIGHT CLOSE TO WHERE THE FRONT WILL STALL OUT. A 500MB LOW WILL
THEN MOVE FROM THE CENTRAL HIGH PLAINS ON TUESDAY EVENING INTO THE
MID SOUTH BY LATE THURSDAY. HAVE KEPT LIKELY POPS GOING WEDNESDAY
AND WEDNESDAY NIGHT WHEN STRONG LARGE SCALE ASCENT FROM THE UPPER
LOW WILL COINCIDE WITH DECENT LOW LEVEL MOISTURE CONVERGENCE ON THE
NORTHERN SIDE OF ITS TRACK. DRY WEATHER STILL LOOKS LIKE IT WILL
SET IN LATE THURSDAY INTO FRIDAY IN THE WAKE OF THE LOW. THE ECMWF
HAS COME INTO AGREEMENT WITH THE GFS ON THE POTENTIAL FOR SCATTERED
SHRA/TSRA ON SATURDAY AS ANOTHER COLD FRONT MOVES ACROSS MO/IL.
WHILE IT WILL BE COOLER ON TUESDAY...TEMPERATURES WILL STILL BE WAY
ABOVE NORMAL WITH THE SLOWER FRONTAL PASSAGE. TEMPERATURES WILL BE
NEAR NORMAL BEHIND THE FRONT ON WEDNESDAY AND THURSDAY WITH THE
CLOUDS AND RAIN CHANCES.
BRITT
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO THE VICINITY OF
LAMBERT FIELD BEFORE SUNRISE. BASICALLY NOTHING HAS CHANGED FROM
EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND OTHERS STAYING
CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND KEEP SCATTERED
1200FT IN AT LAMBERT. OTHERWISE...EXPECT LIGHT AND VARIABLE
SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR THE REST OF THE
NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST AGAIN MONDAY
WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 315 AM CDT SUN MAR 31 2012
SAINT LOUIS...COLUMBIA...AND QUINCY HAVE INDEED SET ALL-TIME
MARCH RECORDS FOR HIGHEST AVERAGE TEMPERATURE OVER THE COURSE OF
THE ENTIRE MONTH...AND NOT BARELY EITHER...BUT BY A LARGE MARGIN.
PLEASE SEE THE MONTHLY CLIMATE SUMMARIES (CLMSTL AND CLMCOU) FOR
ADDITIONAL INFORMATION.
RECORD MAX AND HI MIN TEMPS FOR EARLY APRIL
4/1 4/2
SAINT LOUIS (KSTL) 91/1946 70/1946 88/1946 68/1946
COLUMBIA (KCOU) 88/1946 65/1946 85/1946 65/1956
QUINCY (KUIN) 86/2010 62/1963 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT SUN APR 1 2012
.SHORT TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(TONIGHT)
UNSEASONABLY WARM TEMPERATURES ARE EXPECTED AGAIN TONIGHT WITH
OVERNIGHT LOWS FCST TO BE APPROXIMATELY 20-25 DEG F ABOVE AVERAGE
FOR THIS TIME OF YEAR. MOISTURE ADVECTION AHEAD OF A DEVELOPING LOW
PRESSURE SYSTEM MAY CAUSE SOME STRATUS TO DEVELOP AND ADVECT NWD
OVERNIGHT.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(MONDAY THROUGH NEXT SUNDAY)
TOMORROW STILL LOOKS THAT IT WILL BE AS WARM AS TODAY IF NOT A BIT
WARMER WITH RECORD OR NEAR RECORD HIGHS. CURRENT (3 PM) TEMPS ARE
IN THE MID TO UPPER 80S. LOWS TOMORROW MORNING OVER MUCH OF THE AREA
ARE EXPECTED TO BE ABOUT 3-6 DEGREES WARMER THAN THIS MORNING.
FORECAST SOUNDINGS STILL INDICATE THAT WE SHOULD MIX UP TO AROUND
850MB WHERE TEMPERATURES WILL BE 18-21C RANGE. ANY CLOUDS AROUND IN
THE MORNING SHOULD THIN OUT BY LATE MORNING ALLOWING MAINLY SUNNY
SKIES. THIS SUPPORTS TEMPERATURES IN THE UPPER 80S TO AROUND
90...ESPECIALLY FROM THE ST. METRO AREA WESTWARD WHERE A SOUTH
SOUTHWESTERLY WINDS WILL FAVOR SLIGHTLY WARMER TEMPERATURES IN THE
LEE OF THE OZARKS.
RAIN CHANCES STILL LOOK TO BE SUPPRESSED THROUGH MONDAY NIGHT WITH
AN UPPER RIDGE OVER THE AREA. HAVE LEANED TOWARD THE ECMWF FOR MOST
OF THE FORECAST AS IT HAS BEEN THE MOST CONSISTENT WITH THE
PLACEMENT OF THE UPPER LOW AND THE DEPICTION OF THE SURFACE FRONT
THAT WILL MOVE ACROSS THE AREA ON TUESDAY. THE 500MB TROUGH THAT
THE GFS IS BRINGING INTO EASTERN MO ON TUESDAY LOOKS TO BE OVERLY
INFLUENCED BY CONVECTIVE FEEDBACK. WITH THIS IN MIND...HAVE KEPT
LIKELY POPS OVER THE SOUTHERN CWA ON TUESDAY AFTERNOON WHERE THE
FRONT WILL BE DURING THE MOST UNSTABLE TIME OF THE DAY. I THEN KEEP
CHANCES OF STORMS OVER SOUTHEASTERN MO INTO SOUTHERN IL ON TUESDAY
NIGHT CLOSE TO WHERE THE FRONT WILL STALL OUT. A 500MB LOW WILL
THEN MOVE FROM THE CENTRAL HIGH PLAINS ON TUESDAY EVENING INTO THE
MID SOUTH BY LATE THURSDAY. HAVE KEPT LIKELY POPS GOING WEDNESDAY
AND WEDNESDAY NIGHT WHEN STRONG LARGE SCALE ASCENT FROM THE UPPER
LOW WILL COINCIDE WITH DECENT LOW LEVEL MOISTURE CONVERGENCE ON THE
NORTHERN SIDE OF ITS TRACK. DRY WEATHER STILL LOOKS LIKE IT WILL
SET IN LATE THURSDAY INTO FRIDAY IN THE WAKE OF THE LOW. THE ECMWF
HAS COME INTO AGREEMENT WITH THE GFS ON THE POTENTIAL FOR SCATTERED
SHRA/TSRA ON SATURDAY AS ANOTHER COLD FRONT MOVES ACROSS MO/IL.
WHILE IT WILL BE COOLER ON TUESDAY...TEMPERATURES WILL STILL BE WAY
ABOVE NORMAL WITH THE SLOWER FRONTAL PASSAGE. TEMPERATURES WILL BE
NEAR NORMAL BEHIND THE FRONT ON WEDNESDAY AND THURSDAY WITH THE
CLOUDS AND RAIN CHANCES.
BRITT
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO THE VICINITY OF
LAMBERT FIELD BEFORE SUNRISE. BASICALLY NOTHING HAS CHANGED FROM
EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND OTHERS STAYING
CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND KEEP SCATTERED
1200FT IN AT LAMBERT. OTHERWISE...EXPECT LIGHT AND VARIABLE
SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR THE REST OF THE
NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST AGAIN MONDAY
WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 315 AM CDT SUN MAR 31 2012
SAINT LOUIS...COLUMBIA...AND QUINCY HAVE INDEED SET ALL-TIME
MARCH RECORDS FOR HIGHEST AVERAGE TEMPERATURE OVER THE COURSE OF
THE ENTIRE MONTH...AND NOT BARELY EITHER...BUT BY A LARGE MARGIN.
PLEASE SEE THE MONTHLY CLIMATE SUMMARIES (CLMSTL AND CLMCOU) FOR
ADDITIONAL INFORMATION.
RECORD MAX AND HI MIN TEMPS FOR EARLY APRIL
4/1 4/2
SAINT LOUIS (KSTL) 91/1946 70/1946 88/1946 68/1946
COLUMBIA (KCOU) 88/1946 65/1946 85/1946 65/1956
QUINCY (KUIN) 86/2010 62/1963 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
448 PM CDT MON APR 2 2012
.UPDATE...
SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN
PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION
OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR
INDICATE 45 MPH GUST BECOMING WIDESPREAD.
&&
.PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/
DISCUSSION...
A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND
ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR
ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN
THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE
OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP
EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT
19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS
INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND
ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS
PARTS OF SWRN NEB.
AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS
EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD
INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL
APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF
SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP
INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN
INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK
PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO
OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF
NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH
SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY.
THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT
WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR
ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF
SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE
EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE
NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE
ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT
THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM
WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED
BY A STRONG PACIFIC COLD FRONT.
HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY
WITH HIGHS IN THE 50S TO LOWER 60S.
AVIATION...
WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS
ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS
AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS
PERSIST THE LONGEST...WITH GUSTS OVER 30KTS.
MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING
LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE
ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH
FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE
AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR
CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO
ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS
AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT
/6 AM MDT/ TUESDAY FOR NEZ057-058-069-070.
WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NEZ005-
006-008-009-024>027-036>038-059.
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR NEZ004-022-023-
056-094.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR NEZ004-094.
WIND ADVISORY UNTIL 6 AM MDT TUESDAY FOR NEZ056.
WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR NEZ022-023.
WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ035-
071.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
346 PM CDT MON APR 2 2012
.SHORT TERM...TONIGHT AND TUESDAY. MAIN FORECAST CONCERN WILL BE
CHANCE FOR SHOWERS AND THUNDERSTORMS.
SURFACE ANALYSIS AND SURFACE OBSERVATIONS INDICATE A COLD FRONT
ACROSS THE EASTERN PART OF THE FORECAST AREA THIS AFTERNOON. AHEAD
OF THE COLD FRONT TEMPERATURES HAVE JUMPED AND ARE QUITE WARM.
COOLER TEMPERATURES ARE BEHIND THE FRONT. SATELLITE SHOWS SOME
STRATUS ACROSS THE FAR NORTHERN PART OF THE FORECAST AREA. THIS WAS
SPREADING FURTHER SOUTH THIS MORNING...BUT HAS HELD OFF DURING THE
AFTERNOON.
WINDS HAVE FINALLY STARTED TO INCREASE TO THE WEST AND WILL CONTINUE
TO INCREASE THIS AFTERNOON FOR THE FAR WEST. WILL LEAVE THE WIND
ADVISORY AS IS.
THE POSITION OF THE FRONT IS KEY THIS AFTERNOON FOR THUNDERSTORM
DEVELOPMENT. MODELS HAVE THUNDERSTORMS DEVELOPING ALONG THE FRONT
DURING THE LATE AFTERNOON AND EARLY EVENING. WITH THE CURRENT
LOCATION OF THE FRONT EXPECT THUNDERSTORMS TO BE IN THE SOUTHEAST
PART OF THE FORECAST AREA. THE HRRR KEEPS THE PRECIPITATION IN THE
FAR SOUTHEAST THROUGH THE EVENING WHILE THE NAM AND GFS HAVE IT A
BIT FURTHER TO THE NORTHWEST. THE BEST MUCAPES ARE IN THE FAR
SOUTHEAST PART OF THE FORECAST AREA WITH THE OVER 1000J/KG CAPES FAR
IN THE SOUTHEASTERN PART OF THE FORECAST AREA.
LATER THIS EVENING AND OVERNIGHT AN UPPER LEVEL LOW DEVELOPING ON
THE SOUTHERN HIGH PLAINS STARTS TO DRIFT TO THE NORTH AND PUSHES
PRECIPITATION TO THE NORTH BEHIND THE FRONT. MOST OF THE
PRECIPITATION SHOULD BE IN THE SOUTHERN PART OF THE FORECAST AREA.
THE UPPER LEVEL LOW CONTINUES TO DRIFT THROUGH THE SOUTHERN HIGH
PLAINS ON TUESDAY AND THE CHANCE FOR SHOWERS CONTINUES MAINLY IN THE
SOUTH/SOUTHWEST.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH
PRECIPITATION CHANCES EARLY ON IN THE PERIOD.
LOOKING AT THE TIME FRAME STARTING TUESDAY NIGHT AND CONTINUING
THROUGH WEDNESDAY NIGHT...THE MAIN STORY LIES WITH THE IMPACT ACROSS
THE REGION FROM A PASSING UPPER LEVEL LOW PRESSURE SYSTEM AND
ASSOCIATED PRECIPITATION CHANCES. LATEST MODELS RUNS ARE IN PRETTY
GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING THE LOW CENTERED
OVER THE PANHANDLES OF TX/OK...BUT MORE VARIANCES START TO SHOW UP
THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. THE SYSTEM DOESNT
MAKE A WHOLE LOT OF EASTWARD PROGRESS...WITH A RIDGE AXIS TO THE
EAST EXTENDING FROM THE GULF COAST REGION UP INTO THE ERN
DAKOTAS...AND BY WEDNESDAY EVENING LOOKS TO RANGE IN LOCATION FROM
SC KS TO WRN OK. INCREASED LIFT OUT AHEAD OF THE LOW PRESSURE
SYSTEM WILL HELP WITH THE NORTHWARD SPREAD OF PRECIPITATION FROM THE
SRN PLAINS INTO THE CWA TUESDAY EVENING/OVERNIGHT...WHICH WILL
CONTINUE ON INTO THE DAYTIME HOURS ON WEDNESDAY AS INCREASED LOW/MID
LEVEL FRONTOGENETICAL ON THE NORTHERN SIDE OF THE LOW SHIFTS INTO
THE CWA. DECIDED TO INSERT A MENTION OF ISOLATED THUNDER WED
EVENING...WITH SOME OF THE MODELS/SREF PROBS SHOWING THE POTENTIAL
LINGERING AROUND THE SOUTHEASTERN CORNER OF THE CWA. EXPECTING
PLENTY OF CLOUD COVER AND GENERALLY N/NE WINDS AS THE MAIN SFC LOW
SLIDES TO THE SOUTH OF THE CWA...WITH HIGHS TOPPING OUT IN THE
LOW/MID 50S. MODELS ARE A LITTLE SLOWER THURSDAY EVENING/NIGHT
PUSHING PRECIPITATION CHANCES EAST OF THE CWA AS THE UPPER LEVEL LOW
MAKES ITS WAY TOWARD THE MO RIVER...AND PUSHED POPS BACK WEST TO
INCLUDE ALL COUNTIES.
UPPER LEVEL SHORTWAVE RIDGING BUILDING INTO THE PLAINS IN THE WAKE
OF THIS LATEST SYSTEM IS EXPECTED TO KEEP THURSDAY AND THURSDAY
NIGHT DRY. SEE A SLIGHT BUMP IN HIGHS BUT TEMPS REMAIN ON THE
RELATIVELY COOL SIDE /COMPARED TO THE LAST FEW DAYS...BUT STILL NEAR
OR ABOVE AVG/...WITH THE CWA REMAINING ON THE WRN/SRN FRINGE OF SFC
HIGH PRESSURE OVER THE WRN GREAT LAKES...AND AM EXPECTING LOWER 60S.
NEXT CHANCE FOR PRECIPITATION IS EXPECTED TO COME TO WESTERN
PORTIONS OF THE CWA DURING THE DAY ON FRIDAY AND EXPAND FURTHER EAST
FRIDAY NIGHT...AS ANOTHER SHORTWAVE TROUGH AXIS LOOKS TO SWING
THROUGH THE NORTHERN/CENTRAL PLAINS. MODELS VARY SOME THROUGH THIS
TIMEFRAME...WITH THE GFS SHOWING THIS ENERGY ASSOCIATED WITH AN
ELONGATED LOW OVER WRN/CENTRAL CANADA...WHILE THE EC SHOWS ANY LOW
LOCATED OFF THE PAC NW COAST. KEPT THE HIGHER POPS ACROSS THE NORTH
WHERE THERE IS BETTER AGREEMENT BETWEEN THE MODELS...BUT POPS GO ALL
THE WAY SOUTH TROUGH THE CWA WITH THE GFS CONTINUING TO SHOW MORE
COVERAGE. THE MAIN INSTABILITY AXIS LOOKS TO SET UP JUST WEST OF
THE CWA DURING THE DAY...AND PUSH THROUGH DURING THE OVERNIGHT
HOURS...WITH MUCAPE VALUES UPWARDS OF 7-800 J/KG...SO THREAT OF SOME
STRONG STORMS WILL REMAIN...BUT WILL CONTINUE TO KEEP AN EYE ON THE
POTENTIAL FOR SEVERE STORMS.
KEPT THE FORECAST FOR THE UPCOMING WEEKEND AND INTO MONDAY
DRY...THOUGH THE GFS TRIES TO LINGER SOME POPS IN THE EAST EARLY ON
SAT MORNING. AN ACCOMPANYING SURFACE COLD FRONT IS EXPECTED TO BE ON
ITS WAY THROUGH THE CWA SATURDAY MORNING...BUT MODELS DO VARY SOME
ON THE TIMING. EC IS ON THE QUICKER SIDE...WITH THE FRONT CLEARING
THE CWA SAT MORNING...WHILE THE GFS WOULD BE MORE INTO THE
AFTERNOON. LOOKS TO BE BREEZY DAY ON SATURDAY...WITH NORTHWEST
WINDS PICKING UP BEHIND THE FRONT. MORE ZONAL/NORTHWESTERLY FLOW
SETS UP IN THE UPPER LEVELS FOR SUN/MON WITH A RIDGE SET UP OVER THE
SRN/SWRN CONUS...WITH NO NOTABLE SYSTEM LOOKING TO PASS THROUGH.
BEHIND THE SFC FRONT...HIGH PRESSURE BUILDS IN AND IS THE DOMINANT
FEATURE ON SUNDAY...BRINGING A PLEASANT WITH LIGHT WINDS AND HIGHS
TOPPING OUT IN THE LOWER/MID 60S. MONDAY COULD SEE AN INCREASE IN
WINDS DEPENDING ON THE MODEL...BUT STILL EXPECTING ANOTHER NICE DAY
WITH HIGHS SIMILAR TO SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 1234 PM CDT MON APR 2 2012/
AVIATION...18Z TAF. A COLD FRONT IS NEARLY ON TOP OF THE KGRI
TERMINAL AT THIS TIME AND WILL CONTINUE TO MOVE TO THE EAST. THIS
WILL TURN THE WINDS TO THE NORTH AND INCREASE THEM THROUGH THE
AFTERNOON AND EVENING. THE WINDS WILL WEAKEN THIS EVENING A
LITTLE...BUT EXPECT THAT THEY WILL CONTINUE THROUGH THE NIGHT.
THERE IS A LITTLE CHANCE THERE WILL BE SOME SHOWERS AROUND THE
AREA BUT DO NOT EXPECT A LOT. THERE WILL BE SOME MVFR CEILINGS
LATE TONIGHT INTO TUESDAY MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ039-046-060-
061-072-073-082-083.
KS...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
336 PM CDT MON APR 2 2012
.DISCUSSION...
THE SHORT TERM CONCERNS WILL BE THE POTENTIAL FOR THUNDERSTORMS
AND SEVERE WEATHER AND IF A WIND ADVISORY WILL BE NEEDED.
AT 20Z...THE COLD FRONT HAD FINALLY MADE IT INTO NORFOLK AND THEIR
TEMPERATURES WERE BEGINNING TO FALL. AHEAD OF THE
FRONT...TEMPERATURES TOPPED OUT IN THE 80S TO LOWER 90S. THE LOW
CLOUDS HAD MADE IT INTO THE THE ONEILL AREA AND TEMPERATURES WERE
ONLY IN THE 50S. WINDS IN THE WEST CENTRAL PART OF NEBRASKA WERE
QUITE STRONG WITH GUSTS IN THE 40 TO 50 MPH IN SPOTS.
TONIGHT...THE SURFACE COLD FRONT WILL BE MOVING ACROSS THE REST OF
EASTERN NEBRASKA AND SOUTHWEST IOWA. THE HIGHER UPPER 50S AND
LOWER 60S DEGREE DEWPOINTS AT 20Z EXTENDED FROM BEATRICE TO OMAHA
AND THESE WILL SHIFT EASTWARD WITH TIME. THE 4KM WRF HAD
THUNDERSTORMS ALONG THE FRONT...WHILE THE 18Z NAM WAS DRY...THE
LATEST RUC HAD SOME STORMS DEVELOPING TOWARD FAIRBURY AND THE GFS
HAD AN AREA SIMILAR TO THE 4KM WRF...BUT SHIFTED FARTHER SOUTHEAST
AND MAINLY ALONG AND SOUTH OF I80. THERE IS THE POTENTIAL
FOR THUNDERSTORMS THIS EVENING AHEAD OF AND ALONG THE FRONT AND
WILL MAINTAIN ISOLATED TO SCATTERED THUNDERSTORM CHANCES MAINLY
ALONG AND SOUTH OF I80. THE ATMOSPHERE HAS GOOD INSTABILITY AND
STEEP LAPSE RATES TO WORK WITH...HOWEVER THE SHEAR PARAMETERS DO
NOT APPEAR AS FAVORABLE IN THIS AREA. SPC HAS A SLIGHT RISK AND
THE SLIGHT RISK APPEARS WARRANTED BASED ON CONDITIONAL FACTORS AS
SHOULD THUNDERSTORMS GET GOING THEY COULD CONTAIN SOME HAIL AND
DAMAGING WINDS. BEHIND THE FRONT...ESPECIALLY ACROSS NORTHEAST
NEBRASKA THE WINDS WILL BE STRONG. AT THIS TIME WILL HAVE WINDY
CONDITIONS AT 20 TO 30 MPH WITH GUSTS TO 45...BUT HAVE NOT GONE
WITH A WIND ADVISORY AT THIS TIME. BEHIND THE FRONT...WITH THE LOW
CLOUDS THERE MAY BE SOME SHOWERS IN NORTHEAST NEBRASKA AND SOME OF
THESE MAY LINGER INTO TUESDAY.
THE SOUTHERN ENERGY WITH THIS STORM SYSTEM WILL CLOSE OFF AND LIFT
NORTH. THIS WILL RETURN THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT AND WEDNESDAY AND WEDNESDAY NIGHT AND THEN MOVE OUT
THURSDAY.
THURSDAY NIGHT THROUGH MONDAY....THE STORM SYSTEM THAT WILL
AFFECT US FOR MUCH OF THE WEEK WILL BE OVER SOUTHERN MISSOURI AT
THE START OF THE EXTENDED WITH DRY CONDITIONS...SOUTHEAST BREEZES
AND COMFORTABLE TEMPERATURES IN THE 60S FRIDAY. FRIDAY NIGHT...THE
TROF OVER THE PACIFIC NORTHWEST WILL PUSH FAR ENOUGH EASTWARD TO
PUSH TO FRONT INTO PARTS OF EASTERN NEBRASKA BY 12Z SATURDAY.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF AND ALONG THE
COLD FRONT FRIDAY NIGHT AND SATURDAY. AS THIS SYSTEM MOVES OUT OF
THE AREA...MID LEVEL RIDGING BUILDS IN AND DRY WEATHER AND MORE
SEASONABLE WEATHER IS FORECAST FOR SATURDAY AND SUNDAY.
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
COLD FRONT WILL BE CROSSING ERN NEBRASKA LATER THIS AFTERNOON
THROUGH EARLY EVENING WITH SOME RISK OF CONVECTION ALONG
IT...ESPECIALLY SW OF KLNK. ANY ACTIVITY THAT
DEVELOPS...HOWEVER...WILL MOVE NORTHEAST TOWARD KLNK AND KOMA. DID
NOT MENTION TSTM IN 18Z TAF...ALTHOUGH SOME POP/TEMPO GROUP WITH
CB WAS INCLUDED. MVFR CIGS SHOULD SPREAD IN BEHIND
FRONT...ALTHOUGH DAYTIME HEATING COULD RESTRICT THEIR SE MOVEMENT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/CHERMOK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 PM CDT MON APR 2 2012
.AVIATION...18Z TAF. A COLD FRONT IS NEARLY ON TOP OF THE KGRI
TERMINAL AT THIS TIME AND WILL CONTINUE TO MOVE TO THE EAST. THIS
WILL TURN THE WINDS TO THE NORTH AND INCREASE THEM THROUGH THE
AFTERNOON AND EVENING. THE WINDS WILL WEAKEN THIS EVENING A
LITTLE...BUT EXPECT THAT THEY WILL CONTINUE THROUGH THE NIGHT.
THERE IS A LITTLE CHANCE THERE WILL BE SOME SHOWERS AROUND THE
AREA BUT DO NOT EXPECT A LOT. THERE WILL BE SOME MVFR CEILINGS
LATE TONIGHT INTO TUESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT MON APR 2 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ061-073-083.
WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ039-046-060-
072-082.
KS...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1223 PM CDT MON APR 2 2012
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
COLD FRONT WILL BE CROSSING ERN NEBRASKA LATER THIS AFTERNOON
THROUGH EARLY EVENING WITH SOME RISK OF CONVECTION ALONG
IT...ESPECIALLY SW OF KLNK. ANY ACTIVITY THAT
DEVELOPS...HOWEVER...WILL MOVE NORTHEAST TOWARD KLNK AND KOMA. DID
NOT MENTION TSTM IN 18Z TAF...ALTHOUGH SOME POP/TEMPO GROUP WITH
CB WAS INCLUDED. MVFR CIGS SHOULD SPREAD IN BEHIND
FRONT...ALTHOUGH DAYTIME HEATING COULD RESTRICT THEIR SE MOVEMENT.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 1048 AM CDT MON APR 2 2012/
UPDATE...
UPDATED TO INCREASE HIGHS AHEAD OF FRONT SOME AREAS AND TO
REDUCE/DROP PRECIP CHCS THIS AFTERNOON.
DISCUSSION...
MORNING KOAX SOUNDING SHOWED VERY WARM TEMPERATURE LAYER CENTERED
ON H85 WITH WELL MIXED CAP ABOVE. QUESTION IS WHETHER FRONT CAN
BREAK CAP OVER NEBRASKA AND SOME CONFLICTING INFORMATION FROM
MODELS. LATEST RUC SOUNDING DID TO SOME DEGREE...EVEN IN ECNTRL
SECTIONS...WHILE 00Z GFS WAS MORE RESTRICTED TO SWRN FORECAST
AREA. SHORTER RANGE QPF FORECASTS FROM RUC/HRRR DEVELOPED NO
PRECIP OVER FORECAST AREA THROUGH 00Z WHILE LAST EVENINGS 4KM WRF
DID AS DID THE 06Z NAM/GFS. HOWEVER...12Z NAM REFRAINS FROM
SPREADING PRECIP INTO SRN ZONES UNTIL THIS EVENING. BASED ON
MORNING SOUNDING...FELT ANY CONVECTION THAT MAKES IT INTO
FORECAST AREA WILL EITHER DEVELOP LATE IN THE AFTN ON FRONT OVER
SWRN ZONES OR SW OF NEBRASKA AND THEN ATTEMPT TO BUILD INTO SERN
ZONES THIS EVENING. THUS POPS WERE DROPPED MUCH OF THE AREA N
THROUGH E OF OMA ALONG WITH FAR SERN NEBRASKA THIS AFTN AND
TRIMMED BACK ALL BUT SEVERAL SW COUNTIES FM OMAHA SWWD. ALSO
RAISED MAX TEMPS A BIT IN ERN ZONES BASED ON MORNING SOUNDING AND
BOOSTED WINDS A LITTLE BOTH AHEAD OF AND BEHIND FRONT.
CHERMOK
PREV DISCUSSION... /ISSUED 631 AM CDT MON APR 2 2012/
DISCUSSION...
WV IMAGERY SHOWING FEATURE OF CONCERN...DEEP LONGWAVE TROF...OVER THE
ROCKIES SLOWLY MIGRATING TO THE EAST THIS MORNING WHILE SFC LOW
PRESSURE WAS CENTERED IN NERN CO. MODELS IN DECENT AGREEMENT THAT THE
LONGWAVE TROF WILL FORM INTO A CLOSED LOW OVER THE SRN PLAINS AND
BECOME CUT OFF BY EARLY TUESDAY MORNING...THEN EVENTUALLY LIFTING
ACROSS THE CENTRAL PLAINS EARLY THURSDAY. FOR TODAY...ANTICIPATED
COLD FRONT WILL SWEEP INTO THE CENTRAL PLAINS AS CO SFC LOW TREKS
TOWARD THE MID MS VLY. VARIOUS TIME-SERIES PROGS PUT THE FRONT THRU
THE METRO-AREA SOMETIME EARLY THIS EVENING. PW VALUES AROUND 1.25"
AND KI 35-40 INDICATE ENVIRONMENT WILL BE MOISTURE RICH. THAT...IN
COMBINATION WITH FAVORABLE MUCAPE/EFF SRH/EFF BULK WIND DIFFERENCE
PARAMETERS SUGGEST LATE AFTN/EARLY EVENING SEVERE STORM DEVELOPMENT A
DISTINCT POSSIBILITY...PARTICULARLY AREAS SOUTH OF I-80.
FORTUNATELY...APPEARS THAT TOR THREAT WILL BE MINIMAL DUE TO ML LFC
PROGGED AOA 2200M.
PCPN CHANCES CONTINUE THEN TUESDAY THROUGH THURSDAY MAINLY SOUTH
AS AREA FALLS UNDER INFLUENCE OF CLOSED LOW DYNAMICS TREKKING
ACROSS KS.
OTHERWISE THIS COOLER AIRMASS FILTERING IN THIS WEEK WILL BRING
A NOTICEABLE CHANGE. NEVERTHELESS...NEAR NORMAL MAX TEMPS WILL BE
QUITE ATTAINABLE.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1048 AM CDT MON APR 2 2012
.UPDATE...
UPDATED TO INCREASE HIGHS AHEAD OF FRONT SOME AREAS AND TO
REDUCE/DROP PRECIP CHCS THIS AFTERNOON.
&&
.DISCUSSION...
MORNING KOAX SOUNDING SHOWED VERY WARM TEMPERATURE LAYER CENTERED
ON H85 WITH WELL MIXED CAP ABOVE. QUESTION IS WHETHER FRONT CAN
BREAK CAP OVER NEBRASKA AND SOME CONFLICTING INFORMATION FROM
MODELS. LATEST RUC SOUNDING DID TO SOME DEGREE...EVEN IN ECNTRL
SECTIONS...WHILE 00Z GFS WAS MORE RESTRICTED TO SWRN FORECAST
AREA. SHORTER RANGE QPF FORECASTS FROM RUC/HRRR DEVELOPED NO
PRECIP OVER FORECAST AREA THROUGH 00Z WHILE LAST EVENINGS 4KM WRF
DID AS DID THE 06Z NAM/GFS. HOWEVER...12Z NAM REFRAINS FROM
SPREADING PRECIP INTO SRN ZONES UNTIL THIS EVENING. BASED ON
MORNING SOUNDING...FELT ANY CONVECTION THAT MAKES IT INTO
FORECAST AREA WILL EITHER DEVELOP LATE IN THE AFTN ON FRONT OVER
SWRN ZONES OR SW OF NEBRASKA AND THEN ATTEMPT TO BUILD INTO SERN
ZONES THIS EVENING. THUS POPS WERE DROPPED MUCH OF THE AREA N
THROUGH E OF OMA ALONG WITH FAR SERN NEBRASKA THIS AFTN AND
TRIMMED BACK ALL BUT SEVERAL SW COUNTIES FM OMAHA SWWD. ALSO
RAISED MAX TEMPS A BIT IN ERN ZONES BASED ON MORNING SOUNDING AND
BOOSTED WINDS A LITTLE BOTH AHEAD OF AND BEHIND FRONT.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT MON APR 2 2012/
DISCUSSION...
WV IMAGERY SHOWING FEATURE OF CONCERN...DEEP LONGWAVE TROF...OVER THE
ROCKIES SLOWLY MIGRATING TO THE EAST THIS MORNING WHILE SFC LOW
PRESSURE WAS CENTERED IN NERN CO. MODELS IN DECENT AGREEMENT THAT THE
LONGWAVE TROF WILL FORM INTO A CLOSED LOW OVER THE SRN PLAINS AND
BECOME CUT OFF BY EARLY TUESDAY MORNING...THEN EVENTUALLY LIFTING
ACROSS THE CENTRAL PLAINS EARLY THURSDAY. FOR TODAY...ANTICIPATED
COLD FRONT WILL SWEEP INTO THE CENTRAL PLAINS AS CO SFC LOW TREKS
TOWARD THE MID MS VLY. VARIOUS TIME-SERIES PROGS PUT THE FRONT THRU
THE METRO-AREA SOMETIME EARLY THIS EVENING. PW VALUES AROUND 1.25"
AND KI 35-40 INDICATE ENVIRONMENT WILL BE MOISTURE RICH. THAT...IN
COMBINATION WITH FAVORABLE MUCAPE/EFF SRH/EFF BULK WIND DIFFERENCE
PARAMETERS SUGGEST LATE AFTN/EARLY EVENING SEVERE STORM DEVELOPMENT A
DISTINCT POSSIBILITY...PARTICULARLY AREAS SOUTH OF I-80.
FORTUNATELY...APPEARS THAT TOR THREAT WILL BE MINIMAL DUE TO ML LFC
PROGGED AOA 2200M.
PCPN CHANCES CONTINUE THEN TUESDAY THROUGH THURSDAY MAINLY SOUTH
AS AREA FALLS UNDER INFLUENCE OF CLOSED LOW DYNAMICS TREKKING
ACROSS KS.
OTHERWISE THIS COOLER AIRMASS FILTERING IN THIS WEEK WILL BRING
A NOTICEABLE CHANGE. NEVERTHELESS...NEAR NORMAL MAX TEMPS WILL BE
QUITE ATTAINABLE.
DEE
AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
GUSTY SOUTH TO SOUTHWEST WINDS UP TO 25KTS WILL DEVELOP DURING THE
MORNING AHEAD OF A COLD FRONT MOVING INTO EASTERN NEBRASKA THIS
AFTERNOON. THAT FRONT SHOULD REACH KOFK AROUND 22Z...KLNK NEAR 01Z
AND KOMA NEAR 02Z. NORTHWEST WINDS GUSTING OVER 25KTS WILL FOLLOW
THE FRONT WITH CIGS DECREASING TO MVFR...WITH A GRADUAL LOWERING
TO BELOW FL020 AFTER 06Z. A FEW SHOWERS ARE ALSO POSSIBLE BEHIND
THE FRONT OVERNIGHT. THERE IS A SLIGHT CHANCE THUNDERSTORMS COULD
DEVELOP NEAR KOMA AND KLNK AFTER 21Z AS THE COLD FRONT APPROACHES.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
709 AM CDT MON APR 2 2012
.AVIATION...12Z KGRI TAF. OVERALL...CONFIDENCE IS A BIT LOWER THAN
USUAL WITH REGARD TO WIND AND CEILING TRENDS THROUGH THE PERIOD...AS
MODELS CONTINUE TO STRUGGLE WITH THE TIMING OF THE PRIMARY COLD
FRONTAL PASSAGE...AND IN GENERAL ARE SLOWING IT DOWN. AS A
RESULT...ANTICIPATE FAIRLY LIGHT SOUTH-SOUTHWESTERLY BREEZES
THIS MORNING...BEFORE NORTHWEST WINDS FINALLY KICK IN DURING THE
EARLY TO MID AFTERNOON HOURS BEHIND THE INITIAL FRONTAL PASSAGE.
HOWEVER...IT MAY BE UNTIL LATE AFTERNOON/EARLY EVENING BEFORE
POTENTIAL GUSTS TO AROUND 30KT OR HIGHER ARE FINALLY REALIZED.
MOVING TO CEILING AND PRECIPITATION TRENDS...KEPT THEME FROM
PREVIOUS FORECAST OF A FAIRLY SOLID CEILING IN THE 2000-3000 FT
RANGE SETTLING IN DURING THE EVENING AND OVERNIGHT HOURS...BUT
TIMING COULD EASILY BE OFF BY A FEW HOURS. FINALLY...REGARDING
PRECIPITATION CHANCES...THE EVENING HOURS COULD SEE LEGITIMATE
STRONG THUNDERSTORM ACTIVITY WITHIN 50-75 MILES SOUTH-SOUTHEAST OF
KGRI...BUT AT THIS TIME EXPECT THIS TO STAY FAR ENOUGH AWAY TO
OMIT A MENTION. DID HOWEVER INTRODUCE A VICINITY SHOWER MENTION
FOR THE LATE NIGHT HOURS. STAY TUNED FOR PLENTY OF POTENTIAL
TWEAKING TO THE TAF OVER THE NEXT 24 HOURS...
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT MON APR 2 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR NEZ061-073-083.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM CDT THIS EVENING
FOR NEZ039-046-060-072-082.
KS...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR KSZ005-017.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
419 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
.LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
&&
.AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR NEZ061-073-083.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM CDT THIS EVENING
FOR NEZ039-046-060-072-082.
KS...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
902 PM EDT TUE APR 3 2012
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS SOUTH OF NEW YORK STATE TONIGHT
AND MAY BRING A FEW ISOLATED SHOWERS TO PARTS OF WESTERN NEW YORK.
ARCTIC HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION WEDNESDAY
WITH COOLER TEMPERATURES AND FAIR WEATHER RETURNING FOR THE REST
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A WEAK SURFACE LOW NEAR ACROSS ILLINOIS AND INDIANA WILL TRACK WELL
TO THE SOUTH OF THE REGION OVERNIGHT. AN ASSOCIATED WARM FRONT
EXTENDS TO THE ENE OF THE LOW...TOWARD WESTERN NEW YORK. THE 00Z
BUFFALO SOUNDING SHOWS VERY DRY AIR IN PLACE BENEATH 800 MB...WITH
THIS DRY LAYER LIKELY TO KEEP MOST OF WESTERN NEW YORK DRY.
HOWEVER...900 PM RADAR DOES SHOW SOME SHOWERS ACROSS LAKE ERIE
WHICH MAY CLIP WESTERN PORTIONS OF THE SOUTHERN TIER THIS
EVENING. THE 18Z NAM AND HRRR DO CAPTURE THIS FEATURE TO SOME
DEGREE...BRINGING IT ACROSS THE SOUTHERN TIER DURING THE EVENING
HOURS. IF ANYTHING...THESE MODELS MAY BE A BIT FAR NORTH GIVEN
RADAR TRENDS. FORECAST MAINTAINS CHANCE POPS IN SOUTHERNMOST
PORTIONS OF THE CWA. RADAR SHOWS SOME WEAK RETURNS ACROSS THE
NIAGARA FRONTIER...WHICH APPEAR TO BE SPRINKLES AT BEST.
MOSTLY CLOUDY SKIES THE FIRST HALF OF THE NIGHT WILL KEEP AREA
TEMPERATURES QUITE A BIT WARMER TONIGHT THAN TUESDAY MORNINGS SUB-
FREEZING READINGS. UPPER 30S FOR WESTERN NY AND THE FINGER LAKES
AND LOW TO MID 30S FOR THE NORTH COUNTRY. SKIES SHOULD CLEAR FROM
NW-SE LATE TONIGHT.
ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY BEHIND
THE DEPARTING LOW. 850MB TEMPS WEDNESDAY WILL DROP TO AROUND -3C
WHICH WILL SUPPORT HIGH TEMPS ONLY REACHING INTO THE LOW 50S ACROSS
WESTERN NY DESPITE MAINLY CLEAR SKIES. MORE CLOUDS OVER THE NORTH
COUNTRY AND 850MB TEMPS CLOSER TO -4C/-5C WILL KEEP HIGH TEMPS
LIMITED TO THE UPPER 40S/LOW 50S. WINDS WEDNESDAY WILL BECOME BREEZY
IN THE AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS WITH THE
APPROACHING ARCTIC HIGH AND THE SURFACE LOW OVER THE MID-ATLANTIC
COAST. NORTHWEST GUSTS MAY APPROACH 20 TO 25 MPH ACROSS THE NORTH
COUNTRY AND SOUTHEAST OF THE LAKE.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
IT WILL BE SEASONABLY CHILLY DURING THIS PERIOD AS OUR REGION WILL
REMAIN IN THE COLD SIDE OF A WEAKLY ESTABLISHED REX BLOCK. THIS
LONGWAVE PATTERN WILL FEATURE A CUT OFF LOW OVER THE PLAINS THAT
WILL BE TOPPED BY A HIGH AMPLITUDE RIDGE THAT WILL EXTEND NORTHWARDS
PAST HUDSON BAY. WHILE THE UNDERLYING CUT OFF IS FORECAST TO
PROGRESS EASTWARD ACROSS THE SOUTHERN STATES DURING THIS TIME
FRAME...THE RIDGE WILL BE MUCH SLOWER IN ITS PROGRESSION ACROSS THE
GREAT LAKES REGION.
DOWNSTREAM FROM THE AFOREMENTIONED RIDGE WILL BE A FAIRLY SHARP
TROUGH THAT WILL BE CENTERED OVER QUEBEC AND NEW ENGLAND. THIS WILL
HOLD OUR TEMPERATURES AT OR SLIGHTLY BELOW NORMAL FOR THIS PERIOD...
WHILE AN EXPANSIVE SFC HIGH WILL KEEP THE VAST MAJORITY OF THE
REGION PRECIPITATION FREE. ALL IN ALL...A PRETTY `VANILLA` PERIOD.
A ROBUST SHORTWAVE WILL DROP INTO THE BASE OF THE EASTERN CANADIAN
TROUGH WEDNESDAY NIGHT...AND AS THIS BUNDLE OF ENERGY CROSSES THE
NORTH COUNTRY...THERE MAY BE ENOUGH LOW LEVEL MOISTURE AND LIFT
PRESENT TO POSSIBLY GENERATE A COUPLE WIDELY SEPARATED RAIN OR WET
SNOW SHOWERS. WILL USE LOW CHC POPS TO COVER THIS MINIMAL
POSSIBILITY. THE REMAINDER OF THE FORECAST AREA WILL BE PCPN
FREE...BUT WITH ANOTHER FROST OR FREEZE. H85 TEMPS OF -8C WILL HELP
TO PUSH OVERNIGHT LOWS BACK DOWN INTO THE 20S AND LOWER 30S.
A MASSIVE AREA OF HIGH PRESSURE WILL EASE SOUTHWARDS ACROSS THE
UPPER GREAT LAKES ON THURSDAY. THIS WILL PROVIDE OUR FORECAST AREA
WITH PARTLY/MSTLY SUNNY SKIES...ALTHOUGH WITH H85 TEMPS STILL COLDER
THAN -4C AND SOME RESIDUAL LOW LEVEL MOISTURE IN PLACE...SITES AWAY
FROM THE LAKES MAY EXPERIENCE A FEW HOURS OF BROKEN STRATO-CU CLOUD
COVER. IT WILL BE A COOL DAY AS WELL WITH MAX TEMPS STRUGGLING TO
REACH NORMAL EARLY APRIL VALUES.
AS THE LARGE SFC HIGH SETTLES OVER THE ENTIRE GREAT LAKES REGION
THURSDAY NIGHT...THE PRESSURE GRADIENT WILL WEAKEN SO THAT VERY GOOD
RADIATIONAL COOLING WILL BECOME ESTABLISHED UNDER CLEAR SKIES. THIS
WILL SET THE STAGE FOR YET ANOTHER WIDESPREAD FREEZE AWAY FROM THE
LAKES. OVERNIGHT LOWS WILL RANGE FROM THE FREEZING MARK NEAR THE
LAKE SHORES TO 20 TO 25 IN THE SRN TIER VALLEYS AND EAST OF LAKE
ONTARIO.
FOR FRIDAY AND FRIDAY NIGHT...A H5 RIDGE WILL SLOWLY PUSH ACROSS THE
UPPER GREAT LAKES WHILE THE CORE OF THE SFC HIGH WILL DRIFT TO BE
ABOUT LAKE ERIE. THIS WILL PROVIDE OUR FORECAST AREA WITH NEARLY
CLOUD FREE SKIES AND SEASONABLE TEMPERATURES. THAT WILL INCLUDE
ANOTHER FROSTY NIGHT FRIDAY NIGHT...ESPECIALLY FOR THE SITES WELL
AWAY FROM THE LAKES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
FAIR...SEASONABLY MILD WEATHER AT THE START OF THIS PERIOD WILL
GIVE WAY TO CHILLY UNSETTLED CONDITIONS AS TROUGHINESS OVER THE
HIGH PLAINS OF SASKATCHEWAN WILL DIG SOUTHEAST ACROSS THE GREAT
LAKES REGION. THIS FEATURE WILL EVENTUALLY CARVE ITS WAY INTO A
LONGWAVE TROUGH OVER THE EASTERN HALF OF NORTH AMERICA. AS A
RESULT... TEMPERATURES WILL DEFINITELY TREND DOWNWARDS DURING THIS
PERIOD WITH BELOW NORMAL MERCURY READINGS BECOMING ESTABLISHED BY
TUESDAY. THESE VALUES WILL LIKELY PERSIST THROUGH AT LEAST MID
WEEK.
SATURDAY WILL BE THE NICEST DAY OF THIS PERIOD...BY FAR...AS STRONG
HIGH PRESSURE WILL DRIFT ACROSS OUR FORECAST AREA. SUN FILLED SKIES
WILL BOOST SFC TEMPS INTO THE UPPER 50S TO LOWER 60S FOR MOST AREAS
WITH EVEN WARMER CONDITIONS EXPECTED IN THE GENESEE VALLEY.
AS THE HIGH MOVES OFF THE EAST COAST SUNDAY NIGHT...A PACIFIC BASED
COLD FRONT WILL PUSH ACROSS THE UPPER GREAT LAKES AND MID WEST. THIS
FRONT WILL MOVE ACROSS OUR AREA ON SUNDAY...AND WHILE THE VAST
MAJORITY OF THE DAY SHOULD BE RAIN FREE...THERE WILL PROBABLY BE A 3
HOUR WINDOW OF SCT SHOWER ACTIVITY.
SHORTWAVE RIDGING IN THE WAKE OF THE FRONT SHOULD PROVIDE US WITH
DRY WEATHER SUNDAY NIGHT...BUT ADDITIONAL ENERGY FEEDING INTO THE
TROUGH WILL ENCOURAGE THE SYSTEM TO DIG ITS WAY ACROSS LOWER
ONTARIO. FALLING HGTS AND COLD ADVECTION FROM THIS PROCESS COULD
SUPPORT SOME MORE SHOWERS...MAINLY IN THE AFTERNOON AND MONDAY
NIGHT.
ON TUESDAY...A DEEP LONGWAVE TROUGH WILL BE ANCHORED IN THE VCNTY OF
NEW YORK STATE. THIS WILL KEEP COOL UNSETTLED WEATHER OVER OUR
REGION WITH HIGH TEMPERATURES NOT MAKING IT OUT OF THE 40S.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL BOUNDARY EXTENDING NORTHEAST OF LOW PRESSURE PASSING TO THE
SOUTH WILL GET PUSHED TO THE SOUTH...ALLOWING FOR SKIES TO CLEAR
LATER TONIGHT. UNTIL THEN...EXPECT MAINLY BKN CLOUDS WITH CIGS
WELL ABOVE 3000 FT. THERE WILL BE SCATTERED SHOWERS IN THE
VICINITY OF JHW DURING THE EVENING HOURS...OTHERWISE EXPECT TAF
LOCATIONS TO REMAIN DRY.
SKIES SHOULD SCATTER OUT LATE TONIGHT AND INTO WEDNESDAY
MORNING...WITH CONTINUED VFR CONDITIONS. WINDS WILL PICK UP WITH
DAYTIME MIXING...WITH GUSTS IN THE 20 TO 25 KT RANGE LIKELY.
CLOUDS ALSO MAY INCREASE TO SCT-BKN...BUT WILL LIKELY REMAIN IN
THE VFR FLIGHT CATEGORY.
AN UPPER LEVEL IMPULSE WILL DROP ACROSS EASTERN NEW YORK WEDNESDAY
AFTERNOON...WHICH MAY SPARK A STRAY SHOWER AT ART.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR.
THURSDAY AND FRIDAY...VFR.
SATURDAY...VFR.
&&
.MARINE...
A WEAK LOW WILL PASS JUST SOUTH OF NEW YORK STATE TONIGHT THEN
SETTLE OFF THE EAST COAST BY WEDNESDAY MORNING WITH NO IMPACT TO
WIND AND WAVE CONDITIONS ACROSS THE LAKES. A MODEST NORTH TO
NORTHWEST FLOW OF COLDER AIR WILL SET UP ACROSS THE LAKES WEDNESDAY
AND THURSDAY AS ARCTIC HIGH PRESSURE BUILDS SOUTH ACROSS NY. THE
RESULTING WINDS AND WAVES MAY APPROACH SMALL CRAFT ADVISORY LEVELS
ALONG THE EAST AND SOUTH SHORES OF LAKE ONTARIO IN THE AFTERNOON.
&&
.CLIMATE...
THE MONTHLY CLM CLIMATE SUMMARIES HAVE BEEN UPDATED TO INCLUDE THE
NARRATIVE SECTION AT THE BOTTOM. THEY ARE AVAILABLE ON OUR WEBSITE
UNDER THE CLIMATE SECTION. HERE ARE SOME TIDBITS BELOW...
MARCH 2012 IS A MONTH FOR THE RECORD BOOKS AS AN UNSEASONABLE AND
PERSISTENT WARM PATTERN REMAINED ACROSS THE EASTERN US. FOR BUFFALO
MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.4 DEGREES WHICH IS
+13.4 DEGREES ABOVE NORMAL...AND 2.9 DEGREES WARMER THAN THE
PREVIOUS WARMEST MARCH. THIS 2.9 DEGREES IS THE LARGEST SEPARATION
BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN BUFFALO...WITH
THE NOW SECOND LARGEST SEPARATION 2.6 DEGREES FOR THE TWO WARMEST
MONTHS OF SEPTEMBER.
FOR ROCHESTER MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.3
DEGREES WHICH IS +13.0 DEGREES ABOVE NORMAL...AND 3.5 DEGREES WARMER
THAN THE PREVIOUS WARMEST MARCH. THIS 3.5 DEGREES IS THE LARGEST
SEPARATION BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN
ROCHESTER WITH THE NOW SECOND LARGEST SEPARATION 3.1 DEGREES FOR THE
TWO WARMEST MONTHS OF SEPTEMBER.
FOR BOTH CITIES MARCH FINISHED WARMER THAN THE NORMAL APRIL. THE
47.4 DEGREES AVERAGE MARCH 2012 TEMPERATURE IN BUFFALO WAS 1.5
DEGREES WARMER THAN THE NORMAL APRIL VALUE. FOR ROCHESTER THE 47.3
DEGREES AVERAGE MARCH 2012 TEMPERATURE WAS 1.0 DEGREES WARMER THAN
THE NORMAL APRIL VALUE.
BUFFALO ESTABLISHED SEVEN NEW RECORD HIGH TEMPERATURES IN MARCH
2012...WHILE ROCHESTER ESTABLISHED THREE NEW RECORD HIGH
TEMPERATURES. BOTH CITIES SET 5 NEW RECORD WARM MINIMUM
TEMPERATURES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL
MARINE...SMITH
CLIMATE...THOMAS/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
721 PM EDT TUE APR 3 2012
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL PASS SOUTH OF NEW YORK STATE TONIGHT
AND MAY BRING A FEW ISOLATED SHOWERS TO PARTS OF WESTERN NEW YORK.
ARCTIC HIGH PRESSURE WILL BUILD SOUTH ACROSS THE REGION WEDNESDAY
WITH COOLER TEMPERATURES AND FAIR WEATHER RETURNING FOR THE REST
OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A WEAK SURFACE LOW ACROSS ILLINOIS WILL TRACK ACROSS KENTUCKY
OVERNIGHT. AN ASSOCIATED WARM FRONT EXTENDS TO THE ENE OF THE
LOW...TOWARD WESTERN NEW YORK. WITH VERY DRY AIR IN PLACE BENEATH
700 MB...EXPECT MOST LOCATIONS TO LARGELY REMAIN DRY OVERNIGHT.
HOWEVER...RADAR DOES SHOW SOME SHOWERS ACROSS SOUTHERN ONTARIO
FROM PORT HURON TO LONDON...WITH WHATEVER DOES HOLD TOGETHER WITH
THIS LIKELY TO CLIP WESTERN PORTIONS OF THE SOUTHERN TIER THIS
EVENING. THE HRRR IS LATE...BUT APPEARS TO CAPTURE THIS
EVENTUALLY...WITH THE GFS/RGEM/NAM HINTING AT THIS IN THE RH
FIELDS MORE SO THAN THE QPF. BASED ON THE TRAJECTORY OF THE
SHOWERS...WILL MAINTAIN CHANCE POPS IN SOUTHERNMOST PORTIONS OF
THE CWA...WHILE TRIMMING THINGS BACK TO THE NORTH.
MOSTLY CLOUDY SKIES THE FIRST HALF OF THE NIGHT WILL KEEP AREA
TEMPERATURES QUITE A BIT WARMER TONIGHT THAN TUESDAY MORNINGS SUB-
FREEZING READINGS. UPPER 30S FOR WESTERN NY AND THE FINGER LAKES
AND LOW TO MID 30S FOR THE NORTH COUNTRY. SKIES SHOULD CLEAR FROM
NW-SE LATE TONIGHT.
ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE REGION WEDNESDAY BEHIND
THE DEPARTING LOW. 850MB TEMPS WEDNESDAY WILL DROP TO AROUND -3C
WHICH WILL SUPPORT HIGH TEMPS ONLY REACHING INTO THE LOW 50S ACROSS
WESTERN NY DESPITE MAINLY CLEAR SKIES. MORE CLOUDS OVER THE NORTH
COUNTRY AND 850MB TEMPS CLOSER TO -4C/-5C WILL KEEP HIGH TEMPS
LIMITED TO THE UPPER 40S/LOW 50S. WINDS WEDNESDAY WILL BECOME BREEZY
IN THE AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS WITH THE
APPROACHING ARCTIC HIGH AND THE SURFACE LOW OVER THE MID-ATLANTIC
COAST. NORTHWEST GUSTS MAY APPROACH 20 TO 25 MPH ACROSS THE NORTH
COUNTRY AND SOUTHEAST OF THE LAKE.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
IT WILL BE SEASONABLY CHILLY DURING THIS PERIOD AS OUR REGION WILL
REMAIN IN THE COLD SIDE OF A WEAKLY ESTABLISHED REX BLOCK. THIS
LONGWAVE PATTERN WILL FEATURE A CUT OFF LOW OVER THE PLAINS THAT
WILL BE TOPPED BY A HIGH AMPLITUDE RIDGE THAT WILL EXTEND NORTHWARDS
PAST HUDSON BAY. WHILE THE UNDERLYING CUT OFF IS FORECAST TO
PROGRESS EASTWARD ACROSS THE SOUTHERN STATES DURING THIS TIME
FRAME...THE RIDGE WILL BE MUCH SLOWER IN ITS PROGRESSION ACROSS THE
GREAT LAKES REGION.
DOWNSTREAM FROM THE AFOREMENTIONED RIDGE WILL BE A FAIRLY SHARP
TROUGH THAT WILL BE CENTERED OVER QUEBEC AND NEW ENGLAND. THIS WILL
HOLD OUR TEMPERATURES AT OR SLIGHTLY BELOW NORMAL FOR THIS PERIOD...
WHILE AN EXPANSIVE SFC HIGH WILL KEEP THE VAST MAJORITY OF THE
REGION PRECIPITATION FREE. ALL IN ALL...A PRETTY `VANILLA` PERIOD.
A ROBUST SHORTWAVE WILL DROP INTO THE BASE OF THE EASTERN CANADIAN
TROUGH WEDNESDAY NIGHT...AND AS THIS BUNDLE OF ENERGY CROSSES THE
NORTH COUNTRY...THERE MAY BE ENOUGH LOW LEVEL MOISTURE AND LIFT
PRESENT TO POSSIBLY GENERATE A COUPLE WIDELY SEPARATED RAIN OR WET
SNOW SHOWERS. WILL USE LOW CHC POPS TO COVER THIS MINIMAL
POSSIBILITY. THE REMAINDER OF THE FORECAST AREA WILL BE PCPN
FREE...BUT WITH ANOTHER FROST OR FREEZE. H85 TEMPS OF -8C WILL HELP
TO PUSH OVERNIGHT LOWS BACK DOWN INTO THE 20S AND LOWER 30S.
A MASSIVE AREA OF HIGH PRESSURE WILL EASE SOUTHWARDS ACROSS THE
UPPER GREAT LAKES ON THURSDAY. THIS WILL PROVIDE OUR FORECAST AREA
WITH PARTLY/MSTLY SUNNY SKIES...ALTHOUGH WITH H85 TEMPS STILL COLDER
THAN -4C AND SOME RESIDUAL LOW LEVEL MOISTURE IN PLACE...SITES AWAY
FROM THE LAKES MAY EXPERIENCE A FEW HOURS OF BROKEN STRATO-CU CLOUD
COVER. IT WILL BE A COOL DAY AS WELL WITH MAX TEMPS STRUGGLING TO
REACH NORMAL EARLY APRIL VALUES.
AS THE LARGE SFC HIGH SETTLES OVER THE ENTIRE GREAT LAKES REGION
THURSDAY NIGHT...THE PRESSURE GRADIENT WILL WEAKEN SO THAT VERY GOOD
RADIATIONAL COOLING WILL BECOME ESTABLISHED UNDER CLEAR SKIES. THIS
WILL SET THE STAGE FOR YET ANOTHER WIDESPREAD FREEZE AWAY FROM THE
LAKES. OVERNIGHT LOWS WILL RANGE FROM THE FREEZING MARK NEAR THE
LAKE SHORES TO 20 TO 25 IN THE SRN TIER VALLEYS AND EAST OF LAKE
ONTARIO.
FOR FRIDAY AND FRIDAY NIGHT...A H5 RIDGE WILL SLOWLY PUSH ACROSS THE
UPPER GREAT LAKES WHILE THE CORE OF THE SFC HIGH WILL DRIFT TO BE
ABOUT LAKE ERIE. THIS WILL PROVIDE OUR FORECAST AREA WITH NEARLY
CLOUD FREE SKIES AND SEASONABLE TEMPERATURES. THAT WILL INCLUDE
ANOTHER FROSTY NIGHT FRIDAY NIGHT...ESPECIALLY FOR THE SITES WELL
AWAY FROM THE LAKES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
FAIR...SEASONABLY MILD WEATHER AT THE START OF THIS PERIOD WILL
GIVE WAY TO CHILLY UNSETTLED CONDITIONS AS TROUGHINESS OVER THE
HIGH PLAINS OF SASKATCHEWAN WILL DIG SOUTHEAST ACROSS THE GREAT
LAKES REGION. THIS FEATURE WILL EVENTUALLY CARVE ITS WAY INTO A
LONGWAVE TROUGH OVER THE EASTERN HALF OF NORTH AMERICA. AS A
RESULT... TEMPERATURES WILL DEFINITELY TREND DOWNWARDS DURING THIS
PERIOD WITH BELOW NORMAL MERCURY READINGS BECOMING ESTABLISHED BY
TUESDAY. THESE VALUES WILL LIKELY PERSIST THROUGH AT LEAST MID
WEEK.
SATURDAY WILL BE THE NICEST DAY OF THIS PERIOD...BY FAR...AS STRONG
HIGH PRESSURE WILL DRIFT ACROSS OUR FORECAST AREA. SUN FILLED SKIES
WILL BOOST SFC TEMPS INTO THE UPPER 50S TO LOWER 60S FOR MOST AREAS
WITH EVEN WARMER CONDITIONS EXPECTED IN THE GENESEE VALLEY.
AS THE HIGH MOVES OFF THE EAST COAST SUNDAY NIGHT...A PACIFIC BASED
COLD FRONT WILL PUSH ACROSS THE UPPER GREAT LAKES AND MID WEST. THIS
FRONT WILL MOVE ACROSS OUR AREA ON SUNDAY...AND WHILE THE VAST
MAJORITY OF THE DAY SHOULD BE RAIN FREE...THERE WILL PROBABLY BE A 3
HOUR WINDOW OF SCT SHOWER ACTIVITY.
SHORTWAVE RIDGING IN THE WAKE OF THE FRONT SHOULD PROVIDE US WITH
DRY WEATHER SUNDAY NIGHT...BUT ADDITIONAL ENERGY FEEDING INTO THE
TROUGH WILL ENCOURAGE THE SYSTEM TO DIG ITS WAY ACROSS LOWER
ONTARIO. FALLING HGTS AND COLD ADVECTION FROM THIS PROCESS COULD
SUPPORT SOME MORE SHOWERS...MAINLY IN THE AFTERNOON AND MONDAY
NIGHT.
ON TUESDAY...A DEEP LONGWAVE TROUGH WILL BE ANCHORED IN THE VCNTY OF
NEW YORK STATE. THIS WILL KEEP COOL UNSETTLED WEATHER OVER OUR
REGION WITH HIGH TEMPERATURES NOT MAKING IT OUT OF THE 40S.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
A FRONTAL BOUNDARY EXTENDING NORTHEAST OF LOW PRESSURE PASSING TO THE
SOUTH WILL GET PUSHED TO THE SOUTH...ALLOWING FOR SKIES TO CLEAR
LATER TONIGHT. UNTIL THEN...EXPECT MAINLY BKN CLOUDS WITH CIGS
WELL ABOVE 3000 FT. THERE WILL BE SCATTERED SHOWERS IN THE
VICINITY OF JHW DURING THE EVENING HOURS...OTHERWISE EXPECT TAF
LOCATIONS TO REMAIN DRY.
SKIES SHOULD SCATTER OUT LATE TONIGHT AND INTO WEDNESDAY
MORNING...WITH CONTINUED VFR CONDITIONS. WINDS WILL PICK UP WITH
DAYTIME MIXING...WITH GUSTS IN THE 20 TO 25 KT RANGE LIKELY.
CLOUDS ALSO MAY INCREASE TO SCT-BKN...BUT WILL LIKELY REMAIN IN
THE VFR FLIGHT CATEGORY.
AN UPPER LEVEL IMPULSE WILL DROP ACROSS EASTERN NEW YORK WEDNESDAY
AFTERNOON...WHICH MAY SPARK A STRAY SHOWER AT ART.
OUTLOOK...
WEDNESDAY NIGHT...MAINLY VFR.
THURSDAY AND FRIDAY...VFR.
SATURDAY...VFR.
&&
.MARINE...
A WEAK LOW WILL PASS JUST SOUTH OF NEW YORK STATE TONIGHT THEN
SETTLE OFF THE EAST COAST BY WEDNESDAY MORNING WITH NO IMPACT TO
WIND AND WAVE CONDITIONS ACROSS THE LAKES. A MODEST NORTH TO
NORTHWEST FLOW OF COLDER AIR WILL SET UP ACROSS THE LAKES WEDNESDAY
AND THURSDAY AS ARCTIC HIGH PRESSURE BUILDS SOUTH ACROSS NY. THE
RESULTING WINDS AND WAVES MAY APPROACH SMALL CRAFT ADVISORY LEVELS
ALONG THE EAST AND SOUTH SHORES OF LAKE ONTARIO IN THE AFTERNOON.
&&
.CLIMATE...
THE MONTHLY CLM CLIMATE SUMMARIES HAVE BEEN UPDATED TO INCLUDE THE
NARRATIVE SECTION AT THE BOTTOM. THEY ARE AVAILABLE ON OUR WEBSITE
UNDER THE CLIMATE SECTION. HERE ARE SOME TIDBITS BELOW...
MARCH 2012 IS A MONTH FOR THE RECORD BOOKS AS AN UNSEASONABLE AND
PERSISTENT WARM PATTERN REMAINED ACROSS THE EASTERN US. FOR BUFFALO
MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.4 DEGREES WHICH IS
+13.4 DEGREES ABOVE NORMAL...AND 2.9 DEGREES WARMER THAN THE
PREVIOUS WARMEST MARCH. THIS 2.9 DEGREES IS THE LARGEST SEPARATION
BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN BUFFALO...WITH
THE NOW SECOND LARGEST SEPARATION 2.6 DEGREES FOR THE TWO WARMEST
MONTHS OF SEPTEMBER.
FOR ROCHESTER MARCH FINISHED WITH AN AVERAGE TEMPERATURE OF 47.3
DEGREES WHICH IS +13.0 DEGREES ABOVE NORMAL...AND 3.5 DEGREES WARMER
THAN THE PREVIOUS WARMEST MARCH. THIS 3.5 DEGREES IS THE LARGEST
SEPARATION BETWEEN WARMEST...AND 2ND WARMEST FOR ANY MONTH IN
ROCHESTER WITH THE NOW SECOND LARGEST SEPARATION 3.1 DEGREES FOR THE
TWO WARMEST MONTHS OF SEPTEMBER.
FOR BOTH CITIES MARCH FINISHED WARMER THAN THE NORMAL APRIL. THE
47.4 DEGREES AVERAGE MARCH 2012 TEMPERATURE IN BUFFALO WAS 1.5
DEGREES WARMER THAN THE NORMAL APRIL VALUE. FOR ROCHESTER THE 47.3
DEGREES AVERAGE MARCH 2012 TEMPERATURE WAS 1.0 DEGREES WARMER THAN
THE NORMAL APRIL VALUE.
BUFFALO ESTABLISHED SEVEN NEW RECORD HIGH TEMPERATURES IN MARCH
2012...WHILE ROCHESTER ESTABLISHED THREE NEW RECORD HIGH
TEMPERATURES. BOTH CITIES SET 5 NEW RECORD WARM MINIMUM
TEMPERATURES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...APFFEL/SMITH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL
MARINE...SMITH
CLIMATE...THOMAS/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
657 AM EDT MON APR 2 2012
.SYNOPSIS...
SKIES WILL GRADUALLY CLEAR TODAY AS HIGH PRESSURE BUILDS ACROSS THE
REGION FROM CANADA. TEMPERATURES WILL DROP BELOW FREEZING ACROSS THE
REGION UNDERNEATH THE HIGH PRESSURE RIDGE. THEN A WEAK SYSTEM WILL
BRING A SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS
FOR THE REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...THE MAIN FORECAST CHALLENGE WILL BE DETERMINING EXACTLY
WHEN SKIES WILL CLEAR OUT. AT DAYBREAK SKIES ARE VARIABLE...WITH
PATCHES OF LOW CLOUDS AND CLEARING. THERE IS ALSO SOME PATCHY FOG
IN AREAS WHICH HAVE CLEARED. EXPECT LAKE ONTARIO AND THE IMMEDIATE
SHORELINE TO STAY CLEAR. A BIT SOUTH OF THIS...THERE IS STILL
QUITE A BIT OF MOISTURE...SO CLOUDS MAY FILL BACK IN TO SOME
EXTENT THROUGH THE MORNING HOURS...BEFORE A MORE COMPREHENSIVE
CLEARING THIS AFTERNOON. THE NAM/GFS HAVE BEEN TOO QUICK TO CLEAR
THINGS OUT...WITH THE RUC BUFKIT SHOWING LINGERING MOISTURE UNTIL
LATE MORNING WHEN DRIER AIR BUILDS IN. EXPECT HIGHS TO RANGE FROM THE
UPPER 40S TO AROUND 50.
FOR TONIGHT...HIGH PRESSURE WILL BUILD ACROSS THE REGION...AND WITH
DRIER AIR IN PLACE...SEE NO REASON WHY WE WILL NOT EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS. WITH CONFIDENCE IN RADIATIONAL
COOLING...WILL FAVOR THE COLDER MOS NUMBERS OVER BIAS CORRECTED
GRIDS FOR LOWS TONIGHT. THIS SHOULD RESULT IN FREEZING TEMPERATURES
ACROSS THE REGION...WITH MANY SPOTS FURTHER FROM THE LAKE SHORE
LIKELY TO DROP INTO THE 20S. BECAUSE OF THIS...WILL TRANSITION THE
FREEZE WATCH INTO A FREEZE WARNING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AFTER A COLD AND FROSTY START TO THE DAY...TUESDAY WILL FEATURE A
GRADUAL INCREASE IN MID AND HIGH LEVEL CLOUDS AS A WEAK SURFACE
TROUGH MOVES EAST TOWARD THE LOWER GREAT LAKES. THE MODELS CONTINUE
TO SUGGEST THAT THE DEEPEST LOW LEVEL MOISTURE WILL REMAIN WELL
SOUTH OF NEW YORK STATE...WHILE THE BEST UPPER LEVEL SUPPORT STAYS
TO OUR NORTH IN THE VICINITY OF THE DIGGING UPPER LEVEL TROUGH
OVER ONTARIO PROVINCE. THIS CONFIRMS THE TREND OF PREVIOUS MODEL
RUNS OF A DRY FORECAST.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPERATURES ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING
FROM THE LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S
ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY.
AS THE TROUGH CROSSES THE AREA TUESDAY NIGHT...IT LOOKS LIKE IT WILL
TAP SOME OF THE DEEPER MOISTURE TO OUR SOUTH AND PRODUCE A FEW
SHOWERS. MODEST COOL AIR ADVECTION WILL TAKE PLACE BEHIND THE TROUGH
AND ALLOW TEMPERATURES TO INTO THE 30S. THIS COULD RESULT IN A MIX
OF RAIN AND SNOW SHOWERS FOR A BRIEF TIME ACROSS THE NORTH COUNTRY
WHERE TEMPERATURES ALOFT WILL BE COOLING FASTER.
ON WEDNESDAY...THE UPPER LEVEL TROUGH IS FORECAST DEEPEN OVER
SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND...WITH A FAIRLY SIGNIFICANT
VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN NEW YORK.
WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED WITH THIS
FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS ACROSS THE
NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES. FARTHER TO THE
WEST...A DRIER AIRMASS WILL BE IN PLACE. THIS SHOULD RESULT IN
MAINLY DRY CONDITIONS. ONGOING COLD AIR ADVECTION ASSOCIATED WITH
THE DEEPENING UPPER LEVEL TROUGH WILL RESULT IN A NOTICEABLY COOLER
AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE UPPER 20S
TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THROUGH THIS MORNING...MOISTURE STILL LINGERS IN THE BOUNDARY
LAYER. THROUGH 15Z MAY SEE A BRIEF LOWERING OF CONDITIONS IN
CIGS/VSBY WITH SUNRISE...BUT EXPECT DRIER AIR TO MOVE IN LATE
MORNING...WHICH WILL SCATTER OUT CLOUDS...GIVING WAY TO SKC THIS AFTERNOON.
VFR CONDITIONS TONIGHT UNDER A STRONG HIGH PRESSURE RIDGE.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
NW WINDS AROUND 15 KTS ON THE EASTERN HALF OF LAKE ONTARIO WILL
RESULT IN MARGINAL SMALL CRAFT CONDITIONS. STRONGEST FLOW WILL BE
THROUGH 12Z...SO WILL HANG ONTO THE SCA HEADLINE ON THE EASTERN HALF
OF THE LAKE FOR NOW...BUT MAY BE ABLE TO DROP EARLY IF WINDS DO NOT
INCREASE A BIT.
AFTER THIS...HIGH PRESSURE BUILDS IN...WITH A FAIRLY EXTENDED PERIOD
OF GENERALLY LIGHT WINDS ON THE LAKES EXPECTED. PERSISTENT RIDGING
MAY KEEP THE WATERS FREE OF HEADLINES THROUGH THE END OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LOZ043-
044.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
335 AM EDT MON APR 2 2012
.SYNOPSIS...
SKIES WILL GRADUALLY CLEAR TODAY AS HIGH PRESSURE BUILDS ACROSS THE
REGION FROM CANADA. TEMPERATURES WILL DROP BELOW FREEZING ACROSS THE
REGION UNDERNEATH THE HIGH PRESSURE RIDGE. THEN A WEAK SYSTEM WILL
BRING A SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS
FOR THE REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...THE MAIN FORECAST CHALLENGE WILL BE DETERMINING EXACTLY
WHEN SKIES WILL CLEAR OUT. WITH HIGH PRESSURE SLOWLY BUILDING FROM
THE WEST...SKIES HAVE QUICKLY CLEARED TO THE NORTH...WITH IR
SATELLITE SHOWING A NORTH TO SOUTH CLEARING. HOWEVER...THE 11U-3.9U
SATELLITE PRODUCT SHOWS LOW CLOUDS BUILDING BACK BEHIND THIS
APPARENT CLEARING LINE...WHICH WILL SLOW THE CLEARING PROGRESSION.
WHILE NAM/GFS MODEL GUIDANCE WANTS US TO CLEAR OUT BY 09Z OR
SO...GIVEN THE UPSLOPING NORTHERLY FLOW AND -5C 850 MB TEMPS EXPECT
LOW CLOUDS TO LINGER INTO THE MORNING HOURS IN MOST LOCATIONS SOUTH
OF LAKE ONTARIO...AND PERHAPS INTO THE AFTERNOON ACROSS HIGHER
TERRAIN IN THE SOUTHERN TIER. THIS IS ALSO CONSISTENT WITH SEVERAL
RECENT NORTHERLY FLOW EVENTS...WHERE MODEL GUIDANCE WAS SIMPLY TOO
QUICK TO CLEAR OUT CLOUDS. NOTE RECENT RUNS OF THE RUC SEEM TO
CAPTURE THIS LOW MOISTURE NICELY...SO IN TERMS OF SKY COVER...USED A
RUC WEIGHTED BEND FOR TIMING THE CLEARING. THIS SAID...DRIER AIR
SHOULD EVENTUALLY WIN OUT...WITH ABUNDANT SUNSHINE LIKELY BY THIS
AFTERNOON. TEMPERATURES SHOULD RISE INTO THE UPPER 40S TO AROUND 50
TODAY...ASSUMING THAT CLOUDS CLEAR OUT EARLY ENOUGH FOR SOME
SIGNIFICANT SUNSHINE DURING THE AFTERNOON HOURS.
ALSO...PATCHY FOG WILL LIKELY DEVELOP IN AREAS WHICH DO CLEAR
THROUGH EARLY THIS MORNING...WITH THE BEST CHANCE FOR MORNING FOG
NEAR THE LAKE ONTARIO SHORELINE.
FOR TONIGHT...HIGH PRESSURE WILL BUILD ACROSS THE REGION...AND WITH
DRIER AIR IN PLACE...SEE NO REASON WHY WE WILL NOT EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS. WITH CONFIDENCE IN RADIATIONAL
COOLING...WILL FAVOR THE COLDER MOS NUMBERS OVER BIAS CORRECTED
GRIDS FOR LOWS TONIGHT. THIS SHOULD RESULT IN FREEZING TEMPERATURES
ACROSS THE REGION...WITH MANY SPOTS FURTHER FROM THE LAKE SHORE
LIKELY TO DROP INTO THE 20S. BECAUSE OF THIS...WILL TRANSITION THE
FREEZE WATCH INTO A FREEZE WARNING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AFTER A COLD AND FROSTY START TO THE DAY...TUESDAY WILL FEATURE A
GRADUAL INCREASE IN MID AND HIGH LEVEL CLOUDS AS A WEAK SURFACE
TROUGH MOVES EAST TOWARD THE LOWER GREAT LAKES. THE MODELS CONTINUE
TO SUGGEST THAT THE DEEPEST LOW LEVEL MOISTURE WILL REMAIN WELL
SOUTH OF NEW YORK STATE...WHILE THE BEST UPPER LEVEL SUPPORT STAYS
TO OUR NORTH IN THE VICINITY OF THE DIGGING UPPER LEVEL TROUGH
OVER ONTARIO PROVINCE. THIS CONFIRMS THE TREND OF PREVIOUS MODEL
RUNS OF A DRY FORECAST.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPERATURES ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING
FROM THE LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S
ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY.
AS THE TROUGH CROSSES THE AREA TUESDAY NIGHT...IT LOOKS LIKE IT WILL
TAP SOME OF THE DEEPER MOISTURE TO OUR SOUTH AND PRODUCE A FEW
SHOWERS. MODEST COOL AIR ADVECTION WILL TAKE PLACE BEHIND THE TROUGH
AND ALLOW TEMPERATURES TO INTO THE 30S. THIS COULD RESULT IN A MIX
OF RAIN AND SNOW SHOWERS FOR A BRIEF TIME ACROSS THE NORTH COUNTRY
WHERE TEMPERATURES ALOFT WILL BE COOLING FASTER.
ON WEDNESDAY...THE UPPER LEVEL TROUGH IS FORECAST DEEPEN OVER
SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND...WITH A FAIRLY SIGNIFICANT
VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN NEW YORK.
WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED WITH THIS
FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS ACROSS THE
NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES. FARTHER TO THE
WEST...A DRIER AIRMASS WILL BE IN PLACE. THIS SHOULD RESULT IN
MAINLY DRY CONDITIONS. ONGOING COLD AIR ADVECTION ASSOCIATED WITH
THE DEEPENING UPPER LEVEL TROUGH WILL RESULT IN A NOTICEABLY COOLER
AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE UPPER 20S
TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
THE MAIN CONCERN WILL BE LINGERING MVFR TO IFR CIGS. WITH HIGH
PRESSURE BUILDING FROM THE WEST...SATELLITE SHOWS A GENERAL NORTH
TO SOUTH CLEARING TREND. HOWEVER...THIS CLEARING LINE IS STALLING
SOUTH OF LAKE ONTARIO...WHERE COLD TEMPS ALOFT AND UPSLOPING ARE
THE LIKELY CULPRIT. NOTED NAM/GFS GUIDANCE IS TOO OPTIMISTIC WITH
THIS...WITH THE RUC BUFKIT SOUNDING SUGGESTING THAT LOW CLOUDS
WILL LINGER INTO THIS MORNING. OUTSIDE OF ART...WILL HEDGE MORE
PESSIMISTIC WITH ALL TAFS WITH RESPECT TO THE CLEARING. ONE OTHER
THING TO WATCH FOR...IS IF CLOUDS DO CLEAR...IT MAY QUICKLY BE
REPLACED WITH FOG...OR A LOWER CLOUD DECK AS BOUNDARY LAYER TEMPS
QUICKLY COOL TO THE DEW POINT.
OTHERWISE...EXPECT CLOUDS TO SCATTER OUT IN THE LATE MORNING TO
EARLY AFTERNOON TIMEFRAME AS DRIER AIR WORKS IN AND FINALLY WINS
OUT. INCREASING CONFIDENCE IN VFR CONDITIONS MONDAY AFTERNOON AND
MONDAY NIGHT.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
NW WINDS AROUND 15 KTS ON THE EASTERN HALF OF LAKE ONTARIO WILL
RESULT IN MARGINAL SMALL CRAFT CONDITIONS. STRONGEST FLOW WILL BE
THROUGH 12Z...SO WILL HANG ONTO THE SCA HEADLINE ON THE EASTERN HALF
OF THE LAKE FOR NOW...BUT MAY BE ABLE TO DROP EARLY IF WINDS DO NOT
INCREASE A BIT.
AFTER THIS...HIGH PRESSURE BUILDS IN...WITH A FAIRLY EXTENDED PERIOD
OF GENERALLY LIGHT WINDS ON THE LAKES EXPECTED. PERSISTENT RIDGING
MAY KEEP THE WATERS FREE OF HEADLINES THROUGH THE END OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LOZ043-
044.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
139 AM EDT MON APR 2 2012
.SYNOPSIS...
WHILE STUBBORN LOW CLOUDINESS WILL BE FOUND ACROSS THE REGION EARLY
TONIGHT...HIGH PRESSURE CENTERED OVER JAMES BAY WILL NOSE SOUTH AND
THIS WILL EVENTUALLY CLEAR OUR SKIES LATE TONIGHT AND MONDAY. THE
HIGH PRESSURE WILL BUILD ACROSS OUR REGION LATE MONDAY...AND THIS
WILL SET THE STAGE FOR SEASONABLY COLD CONDITIONS MONDAY NIGHT WITH
A HARD FREEZE LIKELY AWAY FROM THE LAKES. A WEAK SYSTEM WILL BRING A
SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS FOR THE
REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH 100 AM...11U-3.9U SATELLITE SHOWS LOW CLOUDS LINGERING
BUILDING SOUTH OF LAKE ONTARIO...DESPITE THE BROAD CLEARING TREND
TO THE NORTH. BASED ON THIS...EXPECT MOST LOCATIONS WHICH ARE
CLOUDY TO REMAIN SO FOR MOST OF TONIGHT...WHICH WILL LIMIT
RADIATIONAL COOLING. NUDGED UP TEMPS WHERE ITS CLOUDY...AND
CONTINUE WITH A MENTION OF FOG...ESPECIALLY IN AREAS WHICH DO
CLEAR WHERE FOG MAY FORM.
WEAK LOW PRESSURE IN THE VCNTY OF CENTRAL PENNSYLVANIA WILL KEEP A
WAVY FRONTAL BOUNDARY CLOSE ENOUGH TO OUR FORECAST AREA TO HOLD A
WEALTH OF LOW LEVEL MOISTURE IN PLACE FOR THE BULK OF THE UPCOMING
NIGHT. ONCE THE WAVE MOVES EAST...HIGH PRESSURE CENTERED OVER JAMES
BAY WILL BUILD SOUTH OVER THE LOWER GREAT LAKES. WHILE THIS PROCESS
WILL EVENTUALLY PROMOTE CLEARING...IT WILL TAKE SOME TIME.
HAVE ALREADY SLOWED THE CLEARING TREND FOR THE OVERNIGHT...AND MAY
HAVE TO DO THE SAME FOR MONDAY AS A NORTHERLY UPSLOPE FLOW WILL BE
FOUND OVER THE REGION. AS WAS MENTIONED IN PREVIOUS DISCUSSIONS...
THE PAST FEW SCENARIOS SIMILAR TO THIS HAVE SEEN CLOUDS HANG IN MUCH
LONGER...AS MUCH AS 12-18 HOURS LONGER THAN MODEL FORECASTS.
WITH CLOUD COVER MOST OF THE NIGHT...AND A LIGHT 5-8 MPH
BREEZE...HAVE GONE TOWARD THE HIGH END OF MODEL GUIDANCE FOR
OVERNIGHT LOWS. THE BREEZE AND CLOUD COVER WILL LIKELY PREVENT THE
SURFACE FROM SATURATING...AND THUS PREVENT MUCH FROST FORMATION EVEN
IF TEMPERATURES APPROACH FREEZING. WITH THIS IN MIND WILL NOT GO
WITH ANY FROST HEADLINES FOR TONIGHT AND JUST MENTION SOME PATCHY
LIGHT FROST IN THE FORECAST.
IN TERMS OF TEMPERATURES ON MONDAY...850MB TEMPS AROUND -4C WILL
KEEP TEMPS ON THE COOL SIDE WITH UPPER 40S TO AROUND 50 ACROSS LOWER
ELEVATIONS (ASSUMING AN INCREASING AMOUNT SUNSHINE)...AND MID 40S
HIGHER TERRAIN.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MONDAY NIGHT...STRONG CANADIAN HIGH PRESSURE WILL RIDGE DIRECTLY
OVER THE FORECAST AREA. PLENTIFUL DRY AIR AND LIGHT WINDS ASSOCIATED
WITH THE SURFACE HIGH WILL PROVIDE IDEAL CONDITIONS FOR RADIATIONAL
COOLING...ALLOWING TEMPERATURES TO FALL INTO THE MID 20S TO LOW 30S
AREAWIDE...WITH SOME LOWER 20S EVEN POSSIBLE IN THE INTERIOR OF THE
SOUTHERN TIER AND NORTH COUNTRY. AS OUR FROST/FREEZE PROGRAM IS NOW
ACTIVE FOR ALL BUT CATTARAUGUS/ALLEGANY/WYOMING/JEFFERSON/LEWIS
COUNTIES...WE WILL BE ISSUING A FREEZE WATCH FOR MONDAY NIGHT FOR
MUCH OF OUR AREA IN COORDINATION WITH WFO BGM.
TUESDAY AND TUESDAY NIGHT...A WEAK TROUGH OF LOW PRESSURE WILL
SLOWLY DRIFT EAST FROM THE WESTERN GREAT LAKES...IN ASSOCIATION WITH
A MODEST SHORTWAVE TROUGH SLIDING THROUGH THE PREVAILING
NORTHWESTERLY FLOW ALOFT. MODEL GUIDANCE HAS CONTINUED TO TREND
MARKEDLY SLOWER AND WEAKER WITH THIS FEATURE OVER THE PAST TWO
DAYS...AND NOW SUGGESTS THAT THIS FEATURE WILL REMAIN FAR ENOUGH TO
OUR WEST TO RESULT IN A LARGELY DRY DAY TUESDAY...FOLLOWED BY ONLY A
BRIEF CHANCE OF SHOWERS TUESDAY EVENING AS THE MAIN TROUGH AXIS
WORKS ACROSS THE AREA ALONG WITH ONLY LIMITED LIFT/MOISTURE. WITH
THE ABOVE IN MIND...HAVE DROPPED POPS FOR TUESDAY TO SLIGHT CHANCE OR
LESS...WITH ANY LOW-END CHANCE OF SHOWERS NOW CONFINED TO JUST
TUESDAY EVENING. HAVE ALSO REMOVED ANY MENTION OF THUNDER GIVEN THE
MORE UNFAVORABLE TIMING OF THIS SYSTEM AND THE UNIMPRESSIVE NATURE
OF ITS ASSOCIATED LIFT/MOISTURE.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPS ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING FROM THE
LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S ACROSS
THE SOUTHERN TIER. MODEST COOL AIR ADVECTION BEHIND THE LOW WILL
THEN HELP TO SEND TEMPERATURES BACK DOWN INTO THE MID AND UPPER 30S
IN MOST PLACES TUESDAY NIGHT...WITH SOME LOWER 30S POSSIBLE EAST OF
LAKE ONTARIO.
ON WEDNESDAY...UPPER LEVEL TROUGHING WILL CONTINUE TO DIG ACROSS THE
THE EASTERN GREAT LAKES AND NORTHEASTERN STATES...WITH A FAIRLY
SIGNIFICANT VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN
NEW YORK. WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED
WITH THIS FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS
ACROSS THE NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES...WITH
A DRIER AIRMASS OTHERWISE SUPPORTING MAINLY DRY CONDITIONS ACROSS
THE REMAINDER OF THE FORECAST AREA. ONGOING COLD AIR ADVECTION
ASSOCIATED WITH THE DEEPENING TROUGH WILL RESULT IN A NOTICEABLY
COOLER AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A QUIET/DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE
UPPER 20S TO LOWER 30S ANTICIPATED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THE MAIN CONCERN WILL BE LINGERING MVFR TO IFR CIGS. WITH HIGH
PRESSURE BUILDING FROM THE WEST...SATELLITE SHOWS A GENERAL NORTH
TO SOUTH CLEARING TREND. HOWEVER...THIS CLEARING LINE IS STALLING
SOUTH OF LAKE ONTARIO...WHERE COLD TEMPS ALOFT AND UPSLOPING ARE
THE LIKELY CULPRIT. NOTED NAM/GFS GUIDANCE IS TOO OPTIMISTIC WITH
THIS...WITH THE RUC BUFKIT SOUNDING SUGGESTING THAT LOW CLOUDS
WILL LINGER INTO THIS MORNING. OUTSIDE OF ART...WILL HEDGE MORE
PESSIMISTIC WITH ALL TAFS WITH RESPECT TO THE CLEARING. ONE OTHER
THING TO WATCH FOR...IS IF CLOUDS DO CLEAR...IT MAY QUICKLY BE
REPLACED WITH FOG...OR A LOWER CLOUD DECK AS BOUNDARY LAYER TEMPS
QUICKLY COOL TO THE DEW POINT.
OTHERWISE...EXPECT CLOUDS TO SCATTER OUT IN THE LATE MORNING TO
EARLY AFTERNOON TIMEFRAME AS DRIER AIR WORKS IN AND FINALLY WINS
OUT. INCREASING CONFIDENCE IN VFR CONDITIONS MONDAY AFTERNOON AND
MONDAY NIGHT.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
LIGHT WINDS THIS EVENING WILL SHIFT TO THE NORTH AND NORTHEAST
OVERNIGHT AS HIGH PRESSURE WILL PRESS SOUTH FROM JAMES BAY. THESE
WINDS WILL FRESHEN OVERNIGHT THOUGH AS THE PRESSURE GRADIENT WILL
TIGHTEN UP IN ADVANCE OF THE AFOREMENTIONED CANADIAN HIGH PRESSURE
SYSTEM.
THIS WILL RESULT IN MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR A
FEW HOURS LATE TONIGHT THROUGH MONDAY MORNING ALONG THE SOUTH SHORE
OF LAKE ONTARIO. LAKE ERIE WILL ALSO BECOME CHOPPY LATER TONIGHT
THROUGH MONDAY MORNING SOUTHWEST OF DUNKIRK IN NORTHEAST WINDS...BUT
FOR NOW WILL HOLD THIS AREA AT 2-4 FEET WITHOUT ANY HEADLINE.
HIGH PRESSURE WILL BUILD OVER THE LOWER LAKES LATER MONDAY AND
MONDAY NIGHT WITH DIMINISHING WIND AND WAVES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
LOZ042>044.
&&
$$
SYNOPSIS...HITCHCOCK/RSH
NEAR TERM...APFFEL/HITCHCOCK/RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...HITCHCOCK/RSH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1045 PM EDT TUE APR 3 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE CAROLINAS WEDNESDAY NIGHT
AND EARLY THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR FRIDAY
NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN ACROSS THE
CAROLINAS. HIGH PRESSURE WILL WEAKEN AS IT MOVES OFFSHORE ON MONDAY
AS YET ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM...HRRR MODEL OUTPUT INDICATES THE CLUSTER OF
CONVECTION ACROSS THE CENTRAL PORTIONS OF THE CAROLINAS IS PROGGED
TO MAKE SLOW EASTWARD PROGRESS...POSSIBLY REACHING THE WESTERN EDGE
OF THE ILM CWA AT OR UP TO A FEW HRS AFTER MIDNIGHT. BY THAT
TIME...INSTABILITY WILL BE LACKING ESPECIALLY HAVING TRACKED INTO AN
ATM ALREADY NONCONDUCIVE FOR TSRA ACTIVITY TO START WITH. WEAK MID
LEVEL VORTICIES OVER THE WEST/CENTRAL CAROLINAS ARE AIDING THE
FORCING NEEDED TO SUSTAIN THIS CONVECTION AS IT APPROACHES THE ILM
CWA FROM THE WEST DURING THE OVERNIGHT. AS INDICATED B4...HRRR SFC
BASED CAPE BASICALLY NON-EXISTENT ACROSS THE ILM CWA BY THE TIME
THIS ACTIVITY REACHES THE OUTSKIRTS OF THE ILM CWA. WITH THIS
SAID...WILL CONTINUE CURRENT TREND WITH ONLY LOW CHANCE POPS
OVERNIGHT...MAINLY ALONG THE WEST THROUGH NORTHWEST OUTLINE OF THE
ILM CWA. DUE TO LATEST SAT IMAGERY TRENDS AND SFC OBS...CURRENT
FORECAST OF SKY CONDITIONS LOOKS AOK WITH NO CHANGES NEEDED.
FOR MIN TEMP FORECAST AND OVERNIGHT DEWPOINTS...SOME TWEAKING
UPWARDS NEEDED BY 1 TO AS MUCH AS 3 DEGREES BASED ON LATEST SFC OBS
AND LAPS/MSAS ANALYSIS TRENDS...AND WITH SOME AID FROM THE LATEST
RUNS OF THE HRRR AND RUC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...VERY LOW AMPLITUDE TROUGHINESS/WNW FLOW MOVES
OVER THE REGION ON WEDNESDAY IN THE MID LEVELS WHILE LOW LEVELS
CONTINUE TO ADVECT WARMTH AND MOISTURE. A FEW WEAK EMBEDDED MID
LEVEL SHORTWAVES WILL PROVIDE SOME ASCENT THOUGH THE MAIN ENERGY
WILL STREAK ACROSS THE NORTHERN FL PENINSULA. LOW END CHANCE/SCT
COVERAGE APPEARS WARRANTED. LOW 80S EXPECTED FOR A HIGH TEMP FOR ALL
BUT COASTAL LOCALS WHERE JUST ENOUGH ONSHORE COMPONENT EXPECTED TO
TEMPER VALUES...MOST PRONOUNCED ALONG BRUNSWICK CTY. BACKDOOR COLD
FRONT ENTERS FROM THE NORTH BY ABOUT 06Z WED NIGHT. THIS SHOULD LEAD
TO A BRIEF PUSH OF COOLER AND DRIER AIR WHERE PRECIP MAY TAKE A
BREAK LATE WEDNESDAY NIGHT. THIS UNDERCUTTING AIRMASS WILL THEN
START BEING OVERRUN BY A RENEWED SENSE OF WARM AND MOIST ADVECTION
AS THE SOUTHERN BRANCH CUTOFF OPENS UP AND HEADS EAST. THURSDAY WILL
BECOME INCREASINGLY UNSETTLED WITH RAIN CHANCES AND MORESO AMOUNTS
HIGHLY HINGING UPON SOME MODEL DISCREPANCIES. THE HIGH GFS AMOUNTS
APPEAR ON THE HIGH SIDE AND THE FCST FOLLOWS THE DRIER WRF MORE
CLOSELY. HIGH RAIN CHANCES ROUND OUT THE PERIOD AS THE UPPER LOW
TRANSFERS ENERGY TO LOW PRESSURE DEVELOPING OFF THE COAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...BEST CHANCE FOR RAIN IN THE PERIOD WILL BE AT
THE START OF THE PERIOD AS A SOUTHERN STREAM 5H CUTOFF MOVES ACROSS
THE AREA. SURFACE AND UPPER LOW WILL EXIT OFF THE COAST DURING FRI
BRINGING AN END TO PRECIP LATE IN THE DAY. WELL BELOW CLIMO TEMPS
FRI/FRI NIGHT WITH AREA UNDER THE 5H TROUGH/LOW. TEMPS START
TRENDING TO NORMAL SAT AS DEEPER NORTHWEST FLOW DEVELOPS AND THINGS
DRY OUT. REMAINDER OF THE PERIOD WILL BE DRY WITH 2 COLD FRONT
CROSSING THE AREA LATE IN THE PERIOD. FIRST COLD FRONT PASSES DRY ON
MON BUT IS FOLLOWED BY LIMITED COLD ADVECTION AS WINDS QUICKLY
BECOME SOUTHERLY AHEAD OF NEXT...MUCH STRONGER COLD FRONT...CROSSING
THE AREA TUE.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...OLD FRONTAL BOUNDARY SOUTH OF THE REGION IS DIFFUSE AND
PRETTY MUCH WASHED OUT. THE MOISTURE SOUTH OF THE FRONT WILL WAVE
NORTH INTO THE REGION BY TOMORROW MORNING. LOW CONFIDENCE ON SOME
IFR STRATUS AT THE SOUTHERN TERMINALS...BUT KEPT IT IN THERE FOR
SEVERAL HOURS AFTER 07Z. WEDNESDAY...INCREASING PRECIPITABLE WATER
AND CAPES WILL PRODUCED SCATTERED CONVECTION WITH GOOD AFTERNOON
HEATING. LOOK FOR THE RESULTANT BOUNDARY TO KICK OFF A FEW...WITH
MORE SCATTERED CONVECTION INLAND. WINDS WEDNESDAY WILL BE
SOUTHWESTERLY ALL DAY...GUSTY BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS
WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM TUESDAY...CONTINUED MINOR ADJUSTMENTS TO WINDS
OVERNIGHT...MAINLY CONTINUED DUE TO THE SLOW VEERING OF WIND
DIRECTIONS FROM THE S TO SW AS A DIFFUSE WARM FRONT LIFTS ACROSS...
AND NORTH OF THE ILM WATERS DURING THE OVERNIGHT. SPEEDS IN GENERAL
TO REMAIN 10 TO OCCASIONALLY 15 KT. SIGNIFICANT SEAS WILL RUN 2 TO 3
FT THROUGHOUT. A 1 TO 2 FT EASTERLY GROUND SWELL AT 9-11 SECOND
PERIODS WILL DOMINATE SIGNIFICANT SEAS...WITH A 1-2 FOOT 3 TO 5
SECOND PERIOD WIND DRIVEN CHOP ADDING A FOOT OR 2 TO THE OVERALL
SIG. SEAS. COULD POSSIBLY SEE A FEW 4 FOOTERS ACROSS THE SHALLOW
SHOALS OFF CAPE FEAR BUT CONTINUED NOT ENOUGH OF AN OCCURRENCE TO
PLACE IN THE CWF.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...PREFRONTAL FLOW REGIME CRANKS UP AS WEDNESDAY
PROGRESSES AND THE GRADIENT BECOMES PINCHED BETWEEN WEST ATLANTIC
HIGH AND THE APPROACHING BOUNDARY. WEDNESDAY NIGHT THIS MODERATELY
STRONG WIND FIELD WILL START VEERING WITH THE APPROACH OF THE
BOUNDARY. BEING A BACKDOOR COLD FRONT RATHER THAN A MORE CLASSICAL
BOUNDARY COMING IN FROM THE NORTHWEST THIS FRONT WILL MAKE FAIRLY
SLOW PROGRESS SOUTHWARD EARLY THURSDAY. THIS MEANS THAT THE NORTHERN
AND SOUTHERN ZONES WILL SPEND SEVERAL HOURS SPLIT BETWEEN THE NE AND
THE SW WINDS ON EITHER SIDE OF THE BOUNDARY. FURTHER COMPLICATING
MATTERS IS THAT THERE IS UNCERTAINTY REGARDING THE TRACK AND
STRENGTH OF A LOW EXPECTED TO MOVE WEST TO EAST ACROSS THE REGION.
TOUGH TO SAY WHETHER OR NOT SEAS BUILD INTO ADVISORY REALM AT ANY
TIME DURING THE PERIOD BUT AN EXTENDED STRETCH OF SCEC HEADLINES
APPEARS LIKELY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...STRONG NORTHEAST FLOW OVER THE WATERS FRI/FRI
NIGHT WITH GRADIENT PINCHED BETWEEN EXITING SURFACE LOW AND HIGH
BUILDING DOWN THE COAST. HEADLINES WILL LIKELY BE REQUIRED FRI FOR
ALL WATERS. GRADIENT STARTS TO RELAX SAT BUT HEADLINES WILL LIKELY
CARRY OVER INTO THE EVENING BEFORE SEAS DROP BELOW SCA THRESHOLDS.
SURFACE RIDGE AXIS REMAINS WEST OF THE WATERS EARLY SUN...WITH
NORTHEAST FLOW CONTINUING OVER THE WATERS. HOWEVER...SPEEDS WILL BE
MUCH LESS THAN FRI/SAT...10 TO 15 KT INSTEAD OF 20 TO 25 KT.
APPROACHING COLD FRONT LATE IN THE PERIOD WILL RESULT IN WINDS
BECOMING SOUTHERLY SUN AFTERNOON...THOUGH GRADIENT REMAINS WEAK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HOEHLER
SHORT TERM...BACON
LONG TERM...LEBO
AVIATION...LOEWENTHAL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
750 PM EDT TUE APR 3 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE CAROLINAS WEDNESDAY NIGHT
AND EARLY THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR FRIDAY
NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN ACROSS THE
CAROLINAS. HIGH PRESSURE WILL WEAKEN AS IT MOVES OFFSHORE ON MONDAY
AS YET ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 745 PM...HRRR MODEL OUTPUT INDICATES THE CLUSTER OF CONVECTION
ACROSS THE WESTERN PORTIONS OF THE CAROLINAS IS PROGGED TO MAKE SLOW
PROGRESS ESE...REACHING THE WESTERN EDGE OF THE ILM CWA AT OR UP TO
A FEW HRS AFTER MIDNIGHT. BY THAT TIME...INSTABILITY WILL BE LACKING
ESPECIALLY HAVING TRACKED INTO AN ATM ALREADY NONCONDUCIVE FOR TSRA
ACTIVITY TO START WITH. WEAK MID LEVEL VORTICIES OVER THE WESTERN
CAROLINAS ARE AIDING THE FORCING NEEDED TO SUSTAIN THIS CONVECTION
AS IT APPROACHES THE ILM CWA FROM THE WEST DURING THE OVERNIGHT. AS
INDICATED B4...HRRR SFC BASED CAPE BASICALLY NON-EXISTENT ACROSS THE
ILM CWA BY THE TIME THIS ACTIVITY REACHES THE OUTSKIRTS OF THE ILM
CWA. WITH THIS SAID...WILL CONTINUE CURRENT TREND WITH ONLY LOW
CHANCE FOR POPS OVERNIGHT...MAINLY ALONG THE WEST THROUGH NORTHWEST
OUTLINE OF THE ILM CWA. HAVE LOWERED CLOUD AMOUNTS
OVERNIGHT...ESPECIALLY AT THE INITIALIZATION AT 7-8PM...DUE TO
LATEST SAT IMAGERY TRENDS AND SFC OBS. NO REASON TO DETOUR CURRENT
THINKING FOR THE MIN TEMP FORECAST TONIGHT. ONLY SOME TWEAKING OF
SFC DEWPOINTS NEEDED BASED ON LATEST SFC OBS AND LAPS/MSAS
ANALYSIS...AND THE LATEST RUN OF THE HRRR AND RUC.
PREVIOUS DISCUSSION................................................
AS OF 300 PM TUESDAY...A DIFFUSE WARM FRONT ACROSS EASTERN SOUTH
CAROLINA IS NOT REALLY DISCERNIBLE IN WIND OBS ANYMORE...BUT
THERE IS STILL A RATHER WELL-DEFINED DEWPOINT GRADIENT. 3 PM
DEWPOINTS RANGE FROM THE 40S ACROSS SE NORTH CAROLINA TO 55-60 IN
THE SOUTH CAROLINA PEE DEE REGION. THE DIFFUSE FRONT SHOULD MOVE
NORTHEAST AND THROUGH OUR AREA LATER THIS EVENING. THIS NEW AIRMASS
WILL KEEP US UNSEASONABLY WARM TONIGHT WITH LOWS EXPECTED TO RANGE
FROM 60-63...COOLEST IN THE ILM VICINITY.
A HEALTHY SUBSIDENCE INVERSION AROUND 800 MB HAS HELD DEEP
CONVECTION AT BAY SO FAR TODAY. WIDESPREAD CUMULUS MERGED INTO A
STRATOCUMULUS FIELD EARLIER...CAPPED OFF BY THE WARMER MORE STABLE
CONDITIONS ALOFT. MODELS SHOW THIS SUBSIDENCE INVERSION WILL ERODE
THIS EVENING (SOUTH CAROLINA) OR OVERNIGHT (NORTH CAROLINA) WITH THE
APPROACH OF A SERIES OF WEAK UPPER DISTURBANCES...BUT CONDITIONS MAY
BECOME TOO DRY ABOVE THE NOCTURNAL INVERSION TO SUPPORT CONVECTION
OVERNIGHT. ASIDE FROM THE POTENTIAL OF SOME EVENING SHOWERS SOUTH OF
FLORENCE AND ADDITIONAL LATE NIGHT CONVECTION OFFSHORE...WE ARE
KEEPING THE FORECAST DRY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...VERY LOW AMPLITUDE TROUGHINESS/WNW FLOW MOVES
OVER THE REGION ON WEDNESDAY IN THE MID LEVELS WHILE LOW LEVELS
CONTINUE TO ADVECT WARMTH AND MOISTURE. A FEW WEAK EMBEDDED MID
LEVEL SHORTWAVES WILL PROVIDE SOME ASCENT THOUGH THE MAIN ENERGY
WILL STREAK ACROSS THE NORTHERN FL PENINSULA. LOW END CHANCE/SCT
COVERAGE APPEARS WARRANTED. LOW 80S EXPECTED FOR A HIGH TEMP FOR ALL
BUT COASTAL LOCALS WHERE JUST ENOUGH ONSHORE COMPONENT EXPECTED TO
TEMPER VALUES...MOST PRONOUNCED ALONG BRUNSWICK CTY. BACKDOOR COLD
FRONT ENTERS FROM THE NORTH BY ABOUT 06Z WED NIGHT. THIS SHOULD LEAD
TO A BRIEF PUSH OF COOLER AND DRIER AIR WHERE PRECIP MAY TAKE A
BREAK LATE WEDNESDAY NIGHT. THIS UNDERCUTTING AIRMASS WILL THEN
START BEING OVERRUN BY A RENEWED SENSE OF WARM AND MOIST ADVECTION
AS THE SOUTHERN BRANCH CUTOFF OPENS UP AND HEADS EAST. THURSDAY WILL
BECOME INCREASINGLY UNSETTLED WITH RAIN CHANCES AND MORESO AMOUNTS
HIGHLY HINGING UPON SOME MODEL DISCREPANCIES. THE HIGH GFS AMOUNTS
APPEAR ON THE HIGH SIDE AND THE FCST FOLLOWS THE DRIER WRF MORE
CLOSELY. HIGH RAIN CHANCES ROUND OUT THE PERIOD AS THE UPPER LOW
TRANSFERS ENERGY TO LOW PRESSURE DEVELOPING OFF THE COAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...BEST CHANCE FOR RAIN IN THE PERIOD WILL BE AT
THE START OF THE PERIOD AS A SOUTHERN STREAM 5H CUTOFF MOVES ACROSS
THE AREA. SURFACE AND UPPER LOW WILL EXIT OFF THE COAST DURING FRI
BRINGING AN END TO PRECIP LATE IN THE DAY. WELL BELOW CLIMO TEMPS
FRI/FRI NIGHT WITH AREA UNDER THE 5H TROUGH/LOW. TEMPS START
TRENDING TO NORMAL SAT AS DEEPER NORTHWEST FLOW DEVELOPS AND THINGS
DRY OUT. REMAINDER OF THE PERIOD WILL BE DRY WITH 2 COLD FRONT
CROSSING THE AREA LATE IN THE PERIOD. FIRST COLD FRONT PASSES DRY ON
MON BUT IS FOLLOWED BY LIMITED COLD ADVECTION AS WINDS QUICKLY
BECOME SOUTHERLY AHEAD OF NEXT...MUCH STRONGER COLD FRONT...CROSSING
THE AREA TUE.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...OLD FRONTAL BOUNDARY SOUTH OF THE REGION IS DIFFUSE AND
PRETTY MUCH WASHED OUT. THE MOISTURE SOUTH OF THE FRONT WILL WAVE
NORTH INTO THE REGION BY TOMORROW MORNING. LOW CONFIDENCE ON SOME
IFR STRATUS AT THE SOUTHERN TERMINALS...BUT KEPT IT IN THERE FOR
SEVERAL HOURS AFTER 07Z. WEDNESDAY...INCREASING PRECIPITABLE WATER
AND CAPES WILL PRODUCED SCATTERED CONVECTION WITH GOOD AFTERNOON
HEATING. LOOK FOR THE RESULTANT BOUNDARY TO KICK OFF A FEW...WITH
MORE SCATTERED CONVECTION INLAND. WINDS WEDNESDAY WILL BE
SOUTHWESTERLY ALL DAY...GUSTY BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS
WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 745 PM TUESDAY...MINOR ADJUSTMENTS TO WINDS OVERNIGHT...MAINLY
DUE TO THE SLOW VEERING OF WIND DIRECTIONS FROM THE SE-S TO SW AS
THE DIFFUSE WARM FRONT LIFTS ACROSS AND NORTH OF THE ILM WATERS
DURING THE OVERNIGHT. SPEEDS IN GENERAL TO REMAIN 10 TO OCCASIONALLY
15 KT. SIG. SEAS WILL RUN 2 TO 3 FT THROUGHOUT. A 1 TO 2 FT EASTERLY
GROUND SWELL AT 9-11 SECOND PERIODS WILL DOMINATE SIGNIFICANT
SEAS...WITH A 1-2 FOOT 3 TO 5 SECOND PERIOD WIND DRIVEN CHOP ON TOP
OF THE EASTERLY SWELL. COMBINING THE 2...YIELDS SIG SEAS IN THE 2 TO
3 FOOT RANGE OVERNIGHT...POSSIBLY A 4 FOOTER ACROSS THE SHOALS BUT
NOT ENOUGH OF AN OCCURRENCE TO PLACE IN THE CWF.
PREVIOUS DISCUSSION...............................................
AS OF 300 PM TUESDAY...HIGH PRESSURE IS NOW WELL OFF THE CAROLINA
COAST AS OUR WINDS HAVE SHIFTED TO A SOUTHERLY DIRECTION. THERE IS
STILL A NEBULOUS WARM FRONT ACROSS EASTERN SOUTH CAROLINA THAT WILL
SLIP ACROSS THE WATERS THIS EVENING. THE ONLY REAL EVIDENCE OF THIS
FRONTAL PASSAGE WILL BE A SHIFT TO MORE SOUTHWESTERLY WIND
DIRECTIONS. WIND SPEEDS SHOULD PEAK LATE THIS EVENING AROUND 15
KNOTS...OTHERWISE WIND SPEEDS AROUND 10 KNOTS ARE EXPECTED LATE THIS
AFTERNOON...AND AGAIN LATE TONIGHT. ISOLATED SHOWERS/T-STORMS WILL
BECOME POSSIBLE AFTER MIDNIGHT WITH MODELS SHOWING THE BEST
POTENTIAL ACROSS THE NC COASTAL WATERS LATE.
DATA FROM THE FRYING PAN SHOALS BUOY SHOWS SEAS CONSIST OF AT LEAST
TWO SWELL TRAINS AND A LOCAL WIND WAVE. A NORTHEAST AND A SOUTHEAST
SWELL BOTH AVERAGE AROUND 10 SECONDS PERIOD...WITH A MORE CHOPPY 4-5
SECOND WIND CHOP SUPERIMPOSED ON TOP. TOTAL WAVE HEIGHT SHOULD
AVERAGE 3 FT IN OPEN WATERS WITHIN 20 MILES OF SHORE...WITH 2 FOOT
SEAS WEST OF FRYING PAN SHOALS WHERE MUCH OF THE SWELL ENERGY WILL
BE BLOCKED/DISSIPATED ON THE SHOALS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...PREFRONTAL FLOW REGIME CRANKS UP AS WEDNESDAY
PROGRESSES AND THE GRADIENT BECOMES PINCHED BETWEEN WEST ATLANTIC
HIGH AND THE APPROACHING BOUNDARY. WEDNESDAY NIGHT THIS MODERATELY
STRONG WIND FIELD WILL START VEERING WITH THE APPROACH OF THE
BOUNDARY. BEING A BACKDOOR COLD FRONT RATHER THAN A MORE CLASSICAL
BOUNDARY COMING IN FROM THE NORTHWEST THIS FRONT WILL MAKE FAIRLY
SLOW PROGRESS SOUTHWARD EARLY THURSDAY. THIS MEANS THAT THE NORTHERN
AND SOUTHERN ZONES WILL SPEND SEVERAL HOURS SPLIT BETWEEN THE NE AND
THE SW WINDS ON EITHER SIDE OF THE BOUNDARY. FURTHER COMPLICATING
MATTERS IS THAT THERE IS UNCERTAINTY REGARDING THE TRACK AND
STRENGTH OF A LOW EXPECTED TO MOVE WEST TO EAST ACROSS THE REGION.
TOUGH TO SAY WHETHER OR NOT SEAS BUILD INTO ADVISORY REALM AT ANY
TIME DURING THE PERIOD BUT AN EXTENDED STRETCH OF SCEC HEADLINES
APPEARS LIKELY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...STRONG NORTHEAST FLOW OVER THE WATERS FRI/FRI
NIGHT WITH GRADIENT PINCHED BETWEEN EXITING SURFACE LOW AND HIGH
BUILDING DOWN THE COAST. HEADLINES WILL LIKELY BE REQUIRED FRI FOR
ALL WATERS. GRADIENT STARTS TO RELAX SAT BUT HEADLINES WILL LIKELY
CARRY OVER INTO THE EVENING BEFORE SEAS DROP BELOW SCA THRESHOLDS.
SURFACE RIDGE AXIS REMAINS WEST OF THE WATERS EARLY SUN...WITH
NORTHEAST FLOW CONTINUING OVER THE WATERS. HOWEVER...SPEEDS WILL BE
MUCH LESS THAN FRI/SAT...10 TO 15 KT INSTEAD OF 20 TO 25 KT.
APPROACHING COLD FRONT LATE IN THE PERIOD WILL RESULT IN WINDS
BECOMING SOUTHERLY SUN AFTERNOON...THOUGH GRADIENT REMAINS WEAK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...LOEWENTHAL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
317 PM EDT MON APR 2 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT THROUGH
EARLY TUESDAY BEFORE IT MOVES OFFSHORE. UNSETTLED CONDITIONS WILL
PERSIST THROUGH MID WEEK AS THIS FRONT RETURNS NORTH AS A WARM FRONT
ON TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA
WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD
AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN
ACROSS THE SOUTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CLEARLY EVIDENT ON VISIBLE IMAGERY
THIS AFTN IS CURRENTLY STRETCHED EAST TO WEST FROM WILMINGTON...TO
ELIZABETHTOWN...TO ALBEMARLE. THIS HAS NOT BEEN PROGRESSING AS
QUICKLY AS GUIDANCE INDICATED...AND THUS TEMPS HAVE SOARED INTO THE
LOW 80S MOST LOCATIONS. THE EXCEPTION HAS BEEN ACROSS THE BORDER
COUNTIES WHERE A BAND OF PREFRONTAL CLOUDINESS...REMNANTS OF LAST
NIGHTS CONVECTION...HAS SIGNIFICANTLY LIMITED HEATING. STILL EXPECT
MOST LOCATIONS WILL ECLIPSE 80 THIS AFTN AHEAD OF THE COLD FRONT.
CONCERN THOUGH TONIGHT IS CONVECTIVE POTENTIAL ALONG THE BOUNDARY.
HAVE SEEN VERY LITTLE IN THE WAY OF CU ON THE SATELLITE THIS
AFTN...WHICH IS A BIT SURPRISING. HOWEVER...SPC STILL HAS ALL OF SC
OUTLINED FOR POTENTIAL TSTMS ALONG AND AHEAD OF THIS COLD FRONT.
LATEST RUC SOUNDINGS DEPICT SLIGHTLY WEAKER CONVECTIVE INDICES THAN
EXPECTED THIS MORNING...INCLUDING A SUBTLE DECREASE IN MID LEVEL
LAPSE RATES...WHICH MAY BE CONTRIBUTING TO THE LACK OF DIURNAL CU.
ADDITIONALLY...VERY DRY AIR ABOVE 500MB IS LIMITING DEEP UPDRAFTS.
STILL...WILL KEEP SCHC...ALBEIT WITH LOWER ABSOLUTE POP
VALUES...ACROSS SC UNTIL COLD FROPA OCCURS. FEEL THIS IS WARRANTED
SINCE SOME AGITATED CU HAS SHOWN UP IMMEDIATELY ALONG THE
FRONT...AND LOW LEVEL LAPSE RATES WILL BECOME SUPER-ADIABATIC
THROUGH THIS AFTN ACROSS SC ZONES. DO NOT ANTICIPATE TSTMS IN THE NC
COUNTIES WHERE FRONTAL INVERSION WILL SQUELCH ANY SURFACE BASED
INSTABILITY...BUT A SHOWER OR TWO IS POSSIBLE. SEVERE THREAT IS
QUITE LIMITED...BUT AN ISOLATED DAMAGING WIND GUST IS STILL
POSSIBLE...ESPECIALLY ACROSS EXTREME SOUTHERN ZONES.
FROPA WILL MOVE SOUTH OF THE CWA BY SUNSET...FOLLOWED BY GUSTY N/NE
WINDS FOR A FEW HOURS BEFORE GRADIENT SLACKENS AND WINDS EASE. HIGH
PRESSURE BUILDS SOUTHWARD AND SKY CONDITIONS WILL CLEAR...SO
RADIATIONAL COOLING WILL BE DEPENDENT ON HOW QUICKLY WINDS CAN EASE
AFTER SUNSET...TO ALLOW FOR A STEEPER NOCTURNAL INVERSION. HAVE
DROPPED MINS ABOUT A DEGREE ACROSS THE NORTHERN ZONES...LEFT STATUS
QUO ACROSS SC...WITH UPPER 40S IN NC...TO MID 50S NEAR THE BERKLEY
COUNTY LINE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BACKDOOR COLD FRONT OFF TO THE SOUTH WILL ALLOW
RIDGE OF HIGH PRESSURE TO NOSE INTO THE CAROLINAS FROM THE NORTH
EARLY TUESDAY. THIS AIRMASS WILL QUICKLY SLIDE OFF THE COAST BY
AFTERNOON. SOME MOISTURE RETURN WILL BE ENSUE FROM WEST TO EAST
ACROSS THE CAROLINAS. IN THE UPPER LEVELS A SHORT AMPLITUDE RIDGE
WILL HOLD ON FOR THE MOST PART. MODELS STRUGGLING WITH SOME
CONVECTIVELY INDUCED VORT CENTERS EMANATING FROM TEXAS...AND
DEEPENING ON THE TRACK AND STRENGTH OF THESE FEATURES THEY MAY BE
ABLE TO SERVE AS SOME WEAK FORCING LOCALLY. BARRING THIS POSSIBILITY
MOST OF THE AREA LOOKS TO REMAIN RAIN-FREE WITH NEAR SEASONABLE
TEMPERATURES. ADVECTION OF WARMTH AND MOISTURE WILL CONTINUE FOR
THE REMAINDER OF THE PERIOD KEEPING TUESDAY NIGHT VERY MILD
ESPECIALLY DUE TO THE INCREASED CLOUD COVER. THE UPPER RIDGE WILL
CONTINUE TO BE WEAKENED ON WEDNESDAY ALLOWING CLEARER PASSAGE OF
SOME WEAK VORTICITY CENTERS. A PREFRONTAL PIEDMONT TROUGH WILL TEND
TO FOCUS MOST OF THE SCATTERED CONVECTION OVER WESTERN ZONES
INITIALLY. HOWEVER SINCE STORMS WILL HAVE A WELL DEFINED EASTWARD
MOTION THERE WILL BE ONLY A SLIGHT GRADIENT IN FCST POPS AT THIS
TIME. QPF WILL BE HIGHER OVER WRN ZONES (ALTHOUGH STILL QUITE LOW).
DESPITE THE CLOUD COVER MOST PLACES SHOULD HAVE NO TROUBLE SEEING A
HIGH IN THE LOW 80S. COLD FRONT ARRIVES LATE WEDNESDAY NIGHT AND
LOOKS QUITE MOISTURE-CHALLENGED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...PROGRESSIVE PATTERN WILL PREVAIL THROUGH THE
EXTENDED AS A MID LEVEL CYCLONE MOVES ACROSS EARLY FOLLOWED BY BRIEF
RIDGING. FINALLY...AT THE END OF THE PERIOD SUBTLE TROUGHING WILL
MOVE ACROSS. THE FORECAST CHALLENGES CONTINUE TO CENTER AROUND
TIMING AND MAGNITUDE FOR FRIDAY TRANSITIONING TO A TEMPERATURE
FORECAST FOR THE WEEKEND.
STILL SOME UNCERTAINTY WITH REGARDS TO THE CHARACTERISTIC OF THE
SYSTEM FRIDAY AS THE LATEST GFS...AND PAST COUPLE OF CYCLES FOR THAT
MATTER SHOW A CLOSED MID LEVEL CYCLONE MOVING ACROSS THE UPSTATE OF
SOUTH CAROLINA THEN OPENING UP AND MOVING OFF QUICKLY. THE ECMWF AND
ENSEMBLES ARE SIMILAR BUT A BIT FURTHER SOUTH. I HAVE INCREASED POPS
TO LIKELY FOR FRIDAY MATCHING HPC AND INCREASED POPS INTO SATURDAY
MORNING TO ADDRESS SLOWER TIMING WITH A SYSTEM THAT REMAINS CLOSED
FOR A LONGER PERIOD OF TIME.
TEMPERATURES DROP TO JUST BELOW CLIMATOLOGY SATURDAY AND SUNDAY
BEFORE REBOUNDING QUICKLY WITH A SOUTHWEST FLOW MONDAY. SUNDAY
SHOULD BE THE COOLEST MORNING COUPLED WITH THE BEST RADIATIONAL
CONDITIONS WITH MID TO UPPER 40S CWA WIDE. SOME CLIMATOLOGICALLY
FAVORED AREAS COULD SEE A DEGREE OR TWO BELOW 45.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE COLD FRONT CAN CLEARLY BE SEEN IN VISIBLE SATELLITE
IMAGERY AND CONTINUITY WAS USED FOR TIMING OF PASSAGE AT THE
TERMINALS. SOME PATCHY LIGHT RAIN FROM MAINLY MID-LEVEL CLOUDS IS
OCCURRING BUT RADAR LOOPS INDICATES A DECREASING TREND. ANY
MID-LEVEL CEILINGS WILL DECREASE THIS AFTERNOON WITH SCATTERED SKIES
EXPECTED BY LATE AFTERNOON AT ALL TERMINALS. THERE IS HIGH
CONFIDENCE OF VFR AT ALL TERMINALS THROUGH THIS TAF VALID PERIOD. NO
THUNDERSTORMS ARE EXPECTED TO AFFECT THE TERMINALS THIS
AFTERNOON...ALTHOUGH THERE COULD BE SOME ACTIVITY DEVELOP ALONG THE
FRONT SOUTH OF THE FLO/MYR TERMINALS BY LATE AFTERNOON. IF THIS
OCCURS THE STORMS SHOULD MOVE WELL SOUTH OF FLO/LBT BY EVENING.
THIS EVENING WIND SPEEDS DECREASE AND BECOME NORTHEAST TO EAST AS
HIGH PRESSURE SETTLES IN. VFR LEVEL LOW CEILINGS WILL RE-DEVELOP AT
THE SOUTHERNMOST TERMINALS OVERNIGHT AND SPREAD TO THE ILM/LBT
TERMINALS AFTER SUNRISE. MODELS ARE HINTING THAT LIGHT RAIN COULD
RE-DEVELOP AFTER MIDNIGHT...MAINLY WEST AND SOUTH OF FLO.
EXTENDED OUTLOOK...VFR TUESDAY. LOW CONFIDENCE ISOLATED SHOWERS AND
THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A
GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR
FRIDAY. VFR SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CROSSING AMZ250 PRESENTLY...AND
THIS WILL CONTINUE ITS TREK SOUTH THROUGH TONIGHT. WINDS AND SEAS
HAVE EASED A BIT AT THE LOCAL BUOYS...BUT NOTICED STRONG GUSTY WINDS
ACROSS WATERS TO OUR NORTH...AND THUS HAVE EXTENDED THE SCEC THROUGH
6PM FOR THE NORTHERN 2 COASTAL WATER ZONES. EXPECT WINDS TO TURN TO
THE N/NE...FIRST ACROSS AMZ250...LASTLY IN AMZ256...AND GUST TO
AROUND 25 KTS. THIS WILL HELP REBUILD SEAS TO 3-5 FT...ALTHOUGH THE
5 FTERS WILL BE ISOLATED NEAR THE OUTER 20NM BOUNDARY. WINDS EASE
FOR A FEW HOURS AFTER SUNSET AS GRADIENT RELAXES SLIGHTLY IN ADVANCE
OF HIGH PRESSURE...BUT A NE SURGE LATE WILL ONCE AGAIN RAISE WINDS
TO 15-20 KTS KEEPING SEAS AT 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...NORTHEAST WINDS ON TUESDAY WITH A BACKDOOR FRONT
OFF TO THE SOUTH AND HIGH PRESSURE BUILDING IN FROM THE NORTH EARLY
TUESDAY. THIS HIGH WILL MOVE OFF THE COAST BY AFTERNOON BRINGING
VEERING AND PERHAPS DECREASING WINDS. VEERING CONTINUES TUESDAY
NIGHT BRINGING A MORE DEFINED SOUTHERLY COMPONENT. NO REAL SWELL
ENERGY ON THE RADAR SO SEAS GENERALLY 2 TO 3 FT THROUGHOUT.
WEDNESDAY BRINGS A PREFRONTAL SOUTHWESTERLY FLOW REGIME WITH A
TIGHTENING GRADIENT. THIS SHOULD ADD ABOUT A FOOT TO THE PREDOMINANT
WAVE HEIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...NORTHEAST FLOW INITIALLY WILL VEER A BIT TO MORE
TO AN EASTERLY DIRECTION EARLY FRIDAY AS LOW PRESSURE DROPS WELL TO
THE SOUTH. STILL SOME UNCERTAINTY OF THE EXACT TIMING AND PLACEMENT
OF THE SYSTEM SO WE COULD SEE WINDS VEER EVEN MORE THROUGH FRIDAY
THAN THE CURRENT FORECAST ADVERTISES. NORTHEASTERLY FLOW LATE FRIDAY
THROUGH SATURDAY AS HIGH PRESSURE BUILDS IN BEHIND THE SYSTEM. AS
USUAL SURGES ARE DIFFICULT TO TIME BUT SHOULD SEE SEVERAL HOURS OF
SPEEDS NEAR 20 KNOTS ACROSS THE OUTER WATERS. WAVEWATCH SEAS
INCREASE FROM 2-4 FEET EARLY TO 4-7 FEET LATE IN THE PERIOD WITH THE
STRONGER FETCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
304 PM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA THIS
AFTERNOON... BEFORE STALLING OVER THE MOUNTAINS... AND NEAR THE
SOUTH CAROLINA BORDER TONIGHT. THE FRONT WILL THEN TURN BACK
NORTHWARD AS A WARM FRONT TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM MONDAY...
A WARM ADVECTION PATTERN WILL BE UNDERWAY ACROSS CENTRAL NORTH
CAROLINA TUESDAY EVENING AS THE WARM FRONT WILL BE NORTH OF THE
REGION. THE LATEST MODELS GENERALLY AGREE IN THAT THE CHANCE OF
SHOWERS/ISOLATED THUNDERSTORMS WILL BE OF A DIURNAL NATURE IN THE
WARM SECTOR LATE TUESDAY/TUESDAY EVENING... SHOULD BE CONFINED TO
THE MOUNTAINS INTO THE EVENING HOURS BEFORE WEAKENING. THE CURRENT
THINKING IS THAT THERE MAY BE AN ISOLATED SHOWER OR THUNDERSTORM
MAINLY OVER THE WESTERN PIEDMONT BUT CENTRAL NORTH CAROLINA SHOULD
REMAIN LARGELY DRY TUESDAY NIGHT. SINCE WE WILL IN THE WARM
SECTOR... A SW BREEZE AROUND 10 MPH WILL KEEP TEMPERATURES UP
TUESDAY NIGHT WITH LOWS EXPECTED TO BE MOSTLY IN THE UPPER 50S TO
LOWER 60S.
WEDNESDAY AND WEDNESDAY NIGHT...
INCREASING INSTABILITY ALONG WITH STRONG SURFACE HEATING AND AN
APPROACHING UPPER LEVEL DISTURBANCE IN THE NW FLOW ALOFT WILL
INCREASE THE CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON. THE BEST
CHANCE OF THUNDERSTORMS SHOULD BE ALONG OR NEAR 1)A PIEDMONT TROUGH
THAT IS FORECAST TO ALIGN FROM SW TO NE ACROSS OUR REGION... AND 2)
THE ASSOCIATED SURFACE BOUNDARY THAT IS FORECAST TO DIP SOUTH INTO
THE REGION DURING THE LATE AFTERNOON INTO THE EVENING. PARTLY SUNNY
SKIES SHOULD LEAD TO EXCELLENT HEATING AS HIGHS REACH THE 80-85
RANGE... WITH SOME UPPER 80S POSSIBLE IN THE SANDHILLS.
INCREASING WINDS IN THE MID AND UPPER LEVELS SHOULD HELP WITH STORM
ORGANIZATION. MLCAPES OF NEAR 1500+ J/KG ARE EXPECTED TO LEAD TO AT
LEAST SCATTERED THUNDERSTORMS BY EARLY AFTERNOON ALONG THE PIEDMONT
TROUGH... WITH ADDITIONAL CONVECTION EXPECTED TO FIRE ALONG THE
SOUTHWARD MOVING COLD FRONT LATER IN THE AFTERNOON NEAR THE NC/VA
BORDER. THE LATTER MAY EVENTUALLY EVOLVE INTO A LINE OF SHOWERS AND
THUNDERSTORMS. A FEW OF THE STORMS MAY BECOME SEVERE WITH THE MAIN
THREATS BEING STRONG WIND GUSTS TO NEAR SEVERE LIMITS AND POSSIBLY
MARGINALLY SEVERE HAIL (UP TO THE SIZE OF QUARTERS). THE THREAT OF
STRONG STORMS SHOULD PERSIST WELL INTO THE EVENING AND POSSIBLY
OVERNIGHT (IN THE SOUTHERN ZONES). OTHERWISE... HIGHS ARE EXPECTED
TO REACH 80-85 WITH POTENTIALLY SOME UPPER 80S OVER THE SANDHILLS.
WEAK HIGH PRESSURE IS EXPECTED TO PUSH SOUTHWARD FROM THE
MID-ATLANTIC STATES INTO NE SECTIONS OF THE AREA WEDNESDAY NIGHT...
OTHERWISE A WEAK BOUNDARY WILL STALL OVER WESTERN AND SOUTHERN
ZONES. UNDER VARIABLY CLOUDY SKIES... THERE WILL STILL BE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY IN THE SOUTH AND
SOUTHWEST PIEDMONT OVERNIGHT. LOWS WILL BE COOLEST NE AND WARMEST SW
(LOWER 50S TO LOWER 60S).
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 304 PM MONDAY...
THE LATEST MODELS CONTINUE TO ADVERTISE THAT AN APPROACHING
MID-UPPER LEVEL LOW FROM THE SOUTHERN PLAINS STATES WILL GRADUALLY
WEAKEN AND DIP MORE SOUTHERLY ACROSS THE TENNESSEE VALLEY AND OVER
GA/SC THURSDAY THROUGH FRIDAY. THE COMBINATION OF A WEAK SURFACE
HIGH NEAR THE NC/VA COAST COMBINED WITH A WARM FRONT WELL TO OUR
SOUTH SHOULD LEAD TO A MOSTLY CLOUDY DAY THURSDAY. A MOIST EASTERLY
LOW LEVEL FLOW WILL BRING INCREASING ATLANTIC MOISTURE ACROSS OUR
REGION. THIS COMBINED WITH THE APPROACHING UPPER LEVEL LOW WILL
CREATE AT LEAST A CHANCE OF SHOWERS (MAINLY WEST) THURSDAY. AS THE
MID-UPPER LOW DAMPENS AND SLIDES MORE SE... THE BEST CHANCE OF RAIN
WILL LIKELY BE OVER WESTERN AND SOUTHERN NC... WITH THE LEAST CHANCE
ACROSS THE NE ZONES. HOWEVER... UNCERTAINTY STILL ABOUNDS WITH THE
STRENGTH AND TRACK OF THIS UPPER SYSTEM. IF THE CURRENT MODELS ARE
CORRECT... THEN MUCH OF THE HEAVY RAIN SHOULD BE CONFINED JUST TO
OUR SW AS OUR SYSTEM DIVES SE. IF THE SYSTEM REMAINS STRONGER THAN
CURRENTLY FORECAST... THEN IT IS ENTIRELY POSSIBLE THAT IT WOULD
CONTINUE MOVING EAST AND BRING THE HEAVIER RAIN NORTHEASTWARD OVER
CENTRAL NC. AT THE VERY LEAST... THIS LOOKS TO BE A COOL/CLOUDY
PERIOD (THU-FRI)... WITH QPF OF 0.25 TO 0.50 SW... LESSER AMOUNTS
AROUND 0.10 NE. LOWS 50-60 NE TO SW. HIGHS NEAR 60 NORTH TO LOWER
70S SOUTH EXPECTED THURSDAY... POSSIBLY COOLER FRIDAY DEPENDING ON
THE TRACK OF THE SYSTEM AND AMOUNT OF RAIN.
SATURDAY THROUGH MONDAY... MUCH COOLER AND DRIER AIR IS FORECAST
BASED ON THE GENERAL MODEL CONSENSUS OF 1025+ MB SURFACE HIGH
PRESSURE BUILDING SOUTH INTO NC/SC FROM NEW ENGLAND. ANOTHER COLD
FRONT WILL BRING ADDITIONAL COOLING MONDAY NIGHT AND TUESDAY.
LOWS SAT-SUN SHOULD AVERAGE IN THE UPPER 30S TO MID 40S WITH SOME
MID 30S POSSIBLE IN THE NE. HIGHS GENERALLY IN THE MID 60S TO LOWER
70S SAT-SUN... AND 70S MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...KC/VINCENT
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
207 PM EDT MON APR 2 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA TODAY AND MAY RESULT IN
SOME STRONG STORMS ACROSS PORTIONS OF THE AREA THIS AFTERNOON. WEAK
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT THROUGH EARLY
TUESDAY BEFORE IT MOVES OFFSHORE. UNSETTLED CONDITIONS WILL PERSIST
THROUGH MID WEEK AS THIS FRONT RETURNS NORTH AS A WARM FRONT ON
TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA
WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD
AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN
ACROSS THE SOUTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CLEARLY EVIDENT ON VISIBLE IMAGERY
THIS AFTN IS CURRENTLY STRETCHED EAST TO WEST FROM WILMINGTON...TO
ELIZABETHTOWN...TO ALBERMARLE. THIS HAS NOT BEEN PROGRESSING AS
QUICKLY AS GUIDANCE INDICATED...AND THUS TEMPS HAVE SOARED INTO THE
LOW 80S MOST LOCATIONS. THE EXCEPTION HAS BEEN ACROSS THE BORDER
COUNTIES WHERE A BAND OF PREFRONTAL CLOUDINESS...REMNANTS OF LAST
NIGHTS CONVECTION...HAS SIGNIFICANTLY LIMITED HEATING. STILL EXPECT
MOST LOCATIONS WILL ECLIPSE 80 THIS AFTN AHEAD OF THE COLD FRONT.
CONCERN THOUGH TONIGHT IS CONVECTIVE POTENTIAL ALONG THE BOUNDARY.
HAVE SEEN VERY LITTLE IN THE WAY OF CU ON THE SATELLITE THIS
AFTN...WHICH IS A BIT SURPRISING. HOWEVER...SPC STILL HAS ALL OF SC
OUTLINED FOR POTENTIAL TSTMS ALONG AND AHEAD OF THIS COLD FRONT.
LATEST RUC SOUNDINGS DEPICT SLIGHTLY WEAKER CONVECTIVE INDICES THAN
EXPECTED THIS MORNING...INCLUDING A SUBTLE DECREASE IN MID LEVEL
LAPSE RATES...WHICH MAY BE CONTRIBUTING TO THE LACK OF DIURNAL CU.
ADDITIONALLY...VERY DRY AIR ABOVE 500MB IS LIMITING DEEP UPDRAFTS.
STILL...WILL KEEP SCHC...ALBEIT WITH LOWER ABSOLUTE POP
VALUES...ACROSS SC UNTIL COLD FROPA OCCURS. FEEL THIS IS WARRANTED
SINCE SOME AGITATED CU HAS SHOWN UP IMMEDIATELY ALONG THE
FRONT...AND LOW LEVEL LAPSE RATES WILL BECOME SUPER-ADIABATIC
THROUGH THIS AFTN ACROSS SC ZONES. DO NOT ANTICIPATE TSTMS IN THE NC
COUNTIES WHERE FRONTAL INVERSION WILL SQUELCH ANY SURFACE BASED
INSTABILITY...BUT A SHOWER OR TWO IS POSSIBLE. SEVERE THREAT IS
QUITE LIMITED...BUT AN ISOLATED DAMAGING WIND GUST IS STILL
POSSIBLE...ESPECIALLY ACROSS EXTREME SOUTHERN ZONES.
FROPA WILL MOVE SOUTH OF THE CWA BY SUNSET...FOLLOWED BY GUSTY N/NE
WINDS FOR A FEW HOURS BEFORE GRADIENT SLACKENS AND WINDS EASE. HIGH
PRESSURE BUILDS SOUTHWARD AND SKY CONDITIONS WILL CLEAR...SO
RADIATIONAL COOLING WILL BE DEPENDENT ON HOW QUICKLY WINDS CAN EASE
AFTER SUNSET...TO ALLOW FOR A STEEPER NOCTURNAL INVERSION. HAVE
DROPPED MINS ABOUT A DEGREE ACROSS THE NORTHERN ZONES...LEFT STATUS
QUO ACROSS SC...WITH UPPER 40S IN NC...TO MID 50S NEAR THE BERKELY
COUNTY LINE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...WITH SURFACE FRONT JUST SOUTH A COOLER
NORTHEASTERLY FLOW WILL KEEP TEMPS AROUND CLIMO. WEAK HIGH PRESSURE
SHIFTING OFF SHORE WILL ALLOW A RETURN FLOW TO SET UP AT THE SFC BY
LATER ON TUES...WITH DRIER AIR STILL PRESENT ALOFT. THIS WILL ALLOW
OLD BOUNDARY TO THE SOUTH TO GET PUSHED BACK NORTH AS A WARM FRONT
WITH WEAK LIFT GIVING POSSIBILITY OF PCP MAINLY OVER SC ZONES BY
LATE TUES. BY TUES NIGHT A SHORTWAVE WILL TRACK AROUND THE MID TO
UPPER RIDGE ACROSS LOCAL AREA. THIS HELPS TO FLATTEN OUT THE RIDGE
OVER THE SOUTHEAST. EXPECT INCREASING CLOUDS AND CHC OF PCP AS THIS
IMPULSE RIDES THROUGH TUES NIGHT. THIS WILL HELP TO KEEP TEMPS UP
TUES NIGHT. PCP WATER INCREASES UP TO 1.5 INCHES OVERNIGHT TUES INTO
WED. ANOTHER SURFACE COLD FRONT WILL TRACK SOUTH ON WED AND WILL
REACH AREA BY WED EVENING AS MOISTURE IN THE MID TO UPPER LEVELS
INCREASES FROM THE WEST AHEAD OF ANOTHER SYSTEM TRACKING EAST ACROSS
THE TENNESSEE VALLEY. WILL REMAIN IN WARM SECTOR IN A WARMER AND
MORE UNSTABLE ATMOSPHERE AHEAD OF COLD FRONT TRACKING APPROACHING
THE CAROLINAS BY AFTN. OVERALL EXPECT A FAIR AMOUNT OF CLOUDS A CHC
OF SHWRS/TSTMS ON WED. TEMPS SHOULD WARM TO AROUND 80 TO 85 WED IN A
WARMER AND MOISTER SOUTHWEST TO WESTERLY FLOW AHEAD OF NEXT COLD
FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...BACK DOOR COLD FRONT WILL TRACK THROUGH AREA ON
THURS. THIS SHALLOW COOLER AIR WILL ADVECT IN WITH NE TO E FLOW AND
WEST SOUTHWEST FLOW ABOVE IT. GFS SHOWING BEST LIFT EARLY THURS AND
PCP WATER VALUES UP AROUND 1.5 INCHES. EXPECT UNSETTLED WEATHER WITH
CLOUDS AND CHC OF PCP THROUGH THURS INTO FRI BEFORE MID TO UPPER
TROUGH PUSHES A COLD FRONT THROUGH BY SAT. THIS WILL SCOUR OUT ANY
MOISTURE LEFT AND COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FOR
THE WEEKEND IN A DEEPER NORTHERLY FLOW SAT THROUGH SUNDAY. LATEST
GFS NOT AS AGGRESSIVE WITH COLD AIR BUT DOES BRING 850 TEMPS DOWN
FROM 14 C MID WEEK TO 5 C ON SATURDAY. H5 HEIGHTS BOTTOM OUT AS MID
TO UPPER TROUGH AXIS MOVES THROUGH AREA LATE FRI AND THEN RIDGE
BUILDS UP THE EAST COAST WITH HEIGHTS REACHING UP AROUND 580 DEM BY
SUNDAY. PCP WATER VALUES FALL TO LESS THAN A HALF INCH BY SAT AFTN
AND DECREASE FURTHER THROUGH THE REMAINDER OF THE WEEKEND IN DEEP
NORTHEASTERLY FLOW. TEMPS WILL REMAIN AT OR BELOW CLIMO THROUGH THE
LONG TERM PERIOD. INITIALLY ON THURS AND FRI...A SHALLOW COOL POOL
WITH CLOUDS AND PCP WILL HOLD TEMPS DOWN CLOSER TO 70 AND THEN COOL
AND DRY AIR WILL ADVECT IN BEHIND FRONT FOR THE WEEKEND. THIS WILL
KEEP TEMPS AROUND 70 THROUGH THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE COLD FRONT CAN CLEARLY BE SEEN IN VISIBLE SATELLITE
IMAGERY AND CONTINUITY WAS USED FOR TIMING OF PASSAGE AT THE
TERMINALS. SOME PATCHY LIGHT RAIN FROM MAINLY MID-LEVEL CLOUDS IS
OCCURRING BUT RADAR LOOPS INDICATES A DECREASING TREND. ANY
MID-LEVEL CEILINGS WILL DECREASE THIS AFTERNOON WITH SCATTERED SKIES
EXPECTED BY LATE AFTERNOON AT ALL TERMINALS. THERE IS HIGH
CONFIDENCE OF VFR AT ALL TERMINALS THROUGH THIS TAF VALID PERIOD. NO
THUNDERSTORMS ARE EXPECTED TO AFFECT THE TERMINALS THIS
AFTERNOON...ALTHOUGH THERE COULD BE SOME ACTIVITY DEVELOP ALONG THE
FRONT SOUTH OF THE FLO/MYR TERMINALS BY LATE AFTERNOON. IF THIS
OCCURS THE STORMS SHOULD MOVE WELL SOUTH OF FLO/LBT BY EVENING.
THIS EVENING WIND SPEEDS DECREASE AND BECOME NORTHEAST TO EAST AS
HIGH PRESSURE SETTLES IN. VFR LEVEL LOW CEILINGS WILL RE-DEVELOP AT
THE SOUTHERNMOST TERMINALS OVERNIGHT AND SPREAD TO THE ILM/LBT
TERMINALS AFTER SUNRISE. MODELS ARE HINTING THAT LIGHT RAIN COULD
RE-DEVELOP AFTER MIDNIGHT...MAINLY WEST AND SOUTH OF FLO.
EXTENDED OUTLOOK...VFR TUESDAY. LOW CONFIDENCE ISOLATED SHOWERS AND
THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A
GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR
FRIDAY. VFR SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CROSSING AMZ250 PRESENTLY...AND
THIS WILL CONTINUE ITS TREK SOUTH THROUGH TONIGHT. WINDS AND SEAS
HAVE EASED A BIT AT THE LOCAL BUOYS...BUT NOTICED STRONG GUSTY WINDS
ACROSS WATERS TO OUR NORTH...AND THUS HAVE EXTENDED THE SCEC THROUGH
6PM FOR THE NORTHERN 2 COASTAL WATER ZONES. EXPECT WINDS TO TURN TO
THE N/NE...FIRST ACROSS AMZ250...LASTLY IN AMZ256...AND GUST TO
AROUND 25 KTS. THIS WILL HELP REBUILD SEAS TO 3-5 FT...ALTHOUGH THE
5 FTERS WILL BE ISOLATED NEAR THE OUTER 20NM BOUNDAY. WINDS EASE FOR
A FEW HOURS AFTER SUNSET AS GRADIENT RELAXES SLIGHTLY IN ADVANCE OF
HIGH PRESSURE...BUT A NE SURGE LATE WILL ONCE AGAIN RAISE WINDS TO
15-20 KTS KEEPING SEAS AT 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...LINGERING SURFACE COLD FRONT SHOULD BE JUST
SOUTH OF LOCAL WATERS TUES MORNING WITH A LIGHT NE TO E FLOW.
WEAK HIGH PRESSURE BEHIND FRONT WILL SHIFT OFF SHORE AS WINDS
CONTINUE TO VEER AROUND TO THE E-SE BEFORE RETURN FLOW SETS UP
THROUGH LATE TUES WITH WINDS INCREASING OUT OF THE S-SW THROUGH
EARLY WED. WINDS WILL CONTINUE TO VEER ON WED TO THE SW TO W AHEAD
OF COLD FRONT APPROACHING THE CAROLINAS FROM THE NW. SEAS WILL
MAINLY BE 2 TO 3 FT DECREASING SLIGHTLY INITIALLY ON TUES IN
WEAKENING FLOW AND THEN INCREASING IN INCREASING W-SW FLOW ON WED.
THE OFF SHORE COMPONENT TO THE FLOW WILL MAINLY AFFECT THE OUTER
WATERS WITH AN INCREASE IN SEAS UP TO 3 TO 4 FT WED INTO WED
NIGHT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...COLD FRONT WILL MAKE ITS WAY SOUTH ON THURS WITH
WINDS VEERING AROUND FROM THE W-NW TO N-NE THROUGH THE DAY. WINDS
WILL CONTINUE OUT OF THE NE THROUGH FRI AND WILL THEN INCREASE UP
TO 15 TO 25 KTS BY LATE FRI INTO SAT AS SURGE TAKES PLACE BEHIND
FRONT. THESE INCREASING NE WINDS FRI NIGHT WILL TIP SEAS INTO SCA
THRESHOLDS BY FRI EVENING AND COULD REACH AS HIGH AS 7 TO 8 FT IN
OUTER WATERS IN FLOW REMAINING MAINLY PARALLEL TO THE COAST
BY SAT MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
149 PM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
149 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1039 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 635 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS EVENING. EXPECT
A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD CONVECTION THIS
MORNING (BETWEEN ROUGHLY 12-17Z) AND A PERIOD OF MVFR CEILINGS
ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z. OTHERWISE...
EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY OR
SHORTLY AFTER 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT WITH GUSTS UP TO 20 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL
PASSAGE BETWEEN ROUGHLY 13-18Z. WINDS WILL BECOME EASTERLY AT ~5 KT
OR LIGHT/VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE
MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
639 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 635 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS EVENING. EXPECT
A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD CONVECTION THIS
MORNING (BETWEEN ROUGHLY 12-17Z) AND A PERIOD OF MVFR CEILINGS
ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z. OTHERWISE...
EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY OR
SHORTLY AFTER 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT WITH GUSTS UP TO 20 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL
PASSAGE BETWEEN ROUGHLY 13-18Z. WINDS WILL BECOME EASTERLY AT ~5 KT
OR LIGHT/VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE
MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
426 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 425 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS AFTERNOON AND
EVENING. EXPECT A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD
CONVECTION THIS MORNING (BETWEEN ROUGHLY 09-15Z) AND A PERIOD OF
MVFR CEILINGS ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z.
OTHERWISE...EXPECT VFR CONDITIONS TO PREDOMINATE. A ~35 KT WESTERLY
LOW-LEVEL JET AT 1500-2000 FT MAY ALLOW FOR MARGINAL LOW-LEVEL WIND
SHEAR BETWEEN 09-12Z THIS MORNING. HOWEVER...THE PRESENCE OF A 5-10
KT SOUTHWESTERLY BREEZE AT THE SURFACE SUGGESTS IT MAY BE DIFFICULT
FOR SUSTAINED LLWS CRITERIA TO BE MET...DESPITE ~30 DEGREES OF
VEERING AS WELL. TRANSIENT LOW-LEVEL WIND SHEAR WILL BE POSSIBLE IF
SURFACE WINDS BECOME LIGHT/VARIABLE OR CALM...PARTICULARLY IN THE
WAKE OF ANY ISOLD SHOWER ACTIVITY THAT MAY TEMPORARILY CREATE A
STABLE COLD NEAR-SURFACE COLD POOL. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY
12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO 10-15 KT IN
ASSOC/W THE BACKDOOR COLD FRONTAL PASSAGE BETWEEN ROUGHLY 13-16Z.
WINDS WILL BECOME EASTERLY AT ~5 KT OR LIGHT/ VARIABLE FROM SUNSET
THIS EVENING THROUGH SUNRISE TUE MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
345 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 215 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS AFTERNOON AND
EVENING. EXPECT A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD
CONVECTION THIS MORNING (BETWEEN ROUGHLY 09-15Z) AND A PERIOD OF
MVFR CEILINGS ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z.
OTHERWISE...EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY
WINDS AT 5-10 KT AT THE BEGINNING OF THE TAF PERIOD WILL BECOME
WESTERLY BY 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL PASSAGE BETWEEN
ROUGHLY 13-16Z. WINDS WILL BECOME EASTERLY AT ~5 KT OR LIGHT/
VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
152 AM EDT MON APR 2 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA TODAY AND MAY
BRING AN ISOLATED SHOWER OR THUNDERSTORM. UNSETTLED CONDITIONS WILL
RETURN BY MID WEEK AS A LOW PRESSURE SYSTEM APPROACHES THE EASTERN
CAROLINAS. COOL AND DRY HIGH PRESSURE IS EXPECTED TO BUILD INTO THE
REGION LATE IN THE WEEK AND PERSIST INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1030 PM SUNDAY...CLUSTER OF SHOWERS AND ISOLATED TSTMS
ASSOCIATED WITH AN UPPER LEVEL VORT...HAS NEARLY TRACKED ACROSS THE
STATE OF SC THIS EVENING BEFORE FINALLY ENCOUNTERING A STABILIZING
ATMOSPHERE AFTER SUNSET. IT IS ALSO ENCOUNTERING A SHALLOW STABLE
LOW LEVEL MARINE AIR BEHIND A SEA BREEZE THAT TRACKED A GOOD 50
MILES INLAND BEFORE THE CIRCULATION WAS INTERRUPTED BY YOU GUESS
IT...SUNSET. OVERALL...CONVECTION HAS NEARLY DIED OUT ENTIRELY WITH
ONLY A FEW SHOWERS TEMPORARILY LEFT ACROSS SOUTHERN SC AT THE
MOMENT. HAVE REMOVED ALL POPS FOR THIS EVENING...AND THE OVERNIGHT
PERIOD. CONVECTION DROPPING SOUTHWARD ASSOCIATED WITH A SFC COLD
FRONT WILL LIKELY HOLD OFF UNTIL AFTER SEVERAL HRS AFTER MONDAYS
SUNRISE AT WHICH TIME THE ATM WILL BEGIN TO DESTABILIZE. CURRENT MIN
TEMP FCST LOOKS AOK. NOT EXPECTING FOG TO BE A PROBLEM OVERNITE WITH
A SFC SW-W WIND REMAINING ACTIVE OVERNIGHT. LATEST MIN FCST LOOKS
AOK AND C NO REASON TO ALTER.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...BACK DOOR TYPE COLD FRONT WILL BE ON THE
DOORSTEP OF THE NORTHERN PART OF THE CWA AT THE START OF THE PERIOD.
THIS FRONT WILL DROP SOUTH THROUGH MONDAY IN RESPONSE TO A NORTHERN
STREAM 500MB S/W TROUGH PUSHING SE OFF THE MID-ATLANTIC COAST. TWO
QUESTIONS PERSIST ABOUT THIS FROPA...WILL IT PUSH ALL THE WAY
THROUGH THE CWA...AND WILL IT BE ASSOCIATED WITH TSTMS.
AS THE FRONT PUSHES SOUTH...IT WILL ENCOUNTER THE LEADING EDGE OF A
STRONG UPPER RIDGE BUILDING EASTWARD FROM THE GREAT PLAINS. RIDGES
TEND TO WIN THESE PLACEMENT BATTLES...BUT GUIDANCE CONTINUES TO
INSIST THAT FROPA WILL TAKE PLACE THROUGH THE ENTIRE CWA. S/W
DRIVING IT IS FAIRLY POTENT...AND RIDGE IS ONLY BEGINNING TO MOVE
EAST...SO WILL CONTINUE TO SHOW FROPA THROUGH THE AREA MONDAY. AT
THE SAME TIME...DECENT CONVERGENCE ALONG THE BOUNDARY INTO RICH
THETA-E AIR SHOULD SUPPORT SOME SHOWERS AND ISOLATED TSTMS. BEST
CHANCE LOOKS TO BE ACROSS SOUTHERN ZONES WHERE HEATING AND HIGHER
PWATS WILL SUPPORT MORE PRECIP...BUT WEAK NVA AT 500MB AND
CONFLUENCE AT JET LEVEL WILL INHIBIT MUCH IN THE WAY OF CONVECTION.
AM COMFORTABLE WITH THE INHERITED SCHC OF TSTMS...BUT EXPECT VERY
LIGHT PRECIP AS EVIDENCED BY HPC QPF OF ONLY A FEW HUNDREDTHS OF AN
INCH.
TEMPS MONDAY WILL BE TRICKY AS WELL...SINCE 850MB TEMPS WILL FALL
THROUGH THE DAY AND THERE COULD BE QUITE A TEMP GRADIENT FROM SW TO
NE. TEMPS ONLY IN THE UPPER 70S FAR NE COASTAL ZONES...RISING INTO
THE UPPER 80S IN THE PEE DEE REGION OF SC. MINS RANGE FROM AROUND 50
FAR NE TO AROUND 60 IN THE SOUTH.
WEAK CAA ON TUESDAY WILL KEEP TEMPS AROUND CLIMO UNDER PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS DUE TO MOISTURE TRAPPED BENEATH THE
FRONTAL INVERSION. COLD FRONT SOUTH OF THE AREA TUESDAY WILL STALL
AND WAVER BACK NORTH...WHILE INCREASING ISENTROPIC LIFT WILL SUPPORT
INCREASING SHOWERS ACROSS SOUTHERN ZONES...BUT ONCE AGAIN WITH
LIMITED QPF. MINS TUESDAY NIGHT STAY ABOVE 60 ACROSS MOST OF THE
AREA AS HIGH PRESSURE DRIFTS OFFSHORE CREATING WARM SOUTHERLY FLOW
AND CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...MAIN FOCUS FOR THE EXTENDED
REMAINS ON THE MID LEVEL SYSTEM NOW MOVING/DIGGING ACROSS THE
WESTERN U.S. AND ITS MOVEMENT/EVOLUTION THROUGH LATE WEEK. HPC
CONTINUES TO FAVOR THE ENSEMBLE MEAN OF THE ECMWF WHICH IS SLIGHTLY
MORE AMPLIFIED AND SLOWER AND THE GFS MEAN. I HAVE MADE FEW
ADJUSTMENTS IN POPS OTHER THAN TO DECREASE INCREMENTALLY VALUES FOR
THURSDAY AS THE MID LEVEL RIDGE AMPLIFIES ACROSS THE AREA JUST
BEFORE THE MAIN SYSTEM MOVES ACROSS EARLY FRIDAY. FOR WEDNESDAY A
BACKDOOR FRONT CONTINUES TO WARRANT CHANCE POPS. SATURDAY AND SUNDAY
REMAIN DRY FOR NOW.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...KLTX VWP IS MEASURING 40 KT WIND FROM THE WSW AS OF 05Z.
WINDS JUST OFF THE DECK INCREASE RAPIDLY AND WILL INCLUDE WIND SHEAR
IN THE FORECAST WITH THESE HIGHER WINDS MIXING OUT AROUND SUNRISE.
CEILINGS AND VISIBILITIES ARE EXPECTED TO REMAIN IN THE VFR CATEGORY
THROUGH THE TAF PERIOD. HOWEVER...THERE IS A RISK FOR AN IFR STRATUS
LAYER TO DEVELOP THROUGH 09Z OR SO AT THE COAST. SW WINDS WILL SHIFT
TO THE NORTH LATE MORNING AND THIS AFTERNOON FROM N TO S AS A COLD
FRONT SINKS SOUTHWARD ACROSS THE TERMINALS. THERE MAY BE ISOLATED
CONVECTION ALONG AND AHEAD OF THE FRONT...WITH THE RESULTANT ADDING
ANOTHER BOUNDARY. HAVE DECIDED TO ADD VCSH TO THE TAFS...NOT
CONFIDENT ENOUGH TO ADD A TEMPO AT THIS TIME. DEVELOPING GUSTY NORTH
WINDS WILL CONTINUE THROUGH THE AFTERNOON...DIMINISHING DURING THE
EVE AS THEY VEER TO THE NORTHEAST.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORMS
MONDAY NIGHT AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY
WITH A BETTER CHANCE FOR PRECIP ON THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SUNDAY...WINDS CONTINUE TO VEER TO THE SW LATE THIS
EVENING AND HAVE INCREASED TO 10-15 KT. PROGGED BY HRRR AND NAM
MODELS...SW-W WINDS WILL FURTHER INCREASE OVERNIGHT TO 15 TO 20 KT
THRU THE PRE-DAWN HRS OF MONDAY. WIND DRIVEN WAVES WILL DOMINATE
SIGNIFICANT SEAS WITH SEAS BUILDING TO 2 TO 4 FT ...EXCEPT 3 TO 5 FT
ACROSS THE WATERS OFF CAPE FEAR SOUTH TO LITTLE RIVER INLET DUE TO
THE LONGER SW-W FETCH. SCEC THRESHOLDS MAY BE MET FOR THE JUST THE
AFOREMENTIONED WATERS AND WILL MONITOR FOR POSSIBLE ISSUANCE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...COLD FRONT CROSSES THE WATERS DURING
MONDAY...TURNING WINDS FROM THE WEST AT 10-15 KTS EARLY...TO THE NE
AT 10-15 KTS BY MONDAY NIGHT. THIS TRANSITION WILL OCCUR FIRST
ACROSS THE NORTHERN WATERS...AND LATER IN THE DAY ACROSS THE SOUTH.
WAVE SPECTRUM WILL CONSIST OF A LOW AMPLITUDE ESE 1FT/9SEC SWELL AND
A BUILDING 3-4FT/5SEC NE WIND WAVE. THESE WILL COMBINE TO CREATE
SEAS OF 2-3 FT...SLIGHTLY LOWER IN THE SHADOWED REGION SW OF FRYING
PAN SHOALS. HIGH PRESSURE DRIFTS OFFSHORE TUESDAY ALLOWING WINDS TO
SLOWLY VEER TO THE SOUTH AS RETURN FLOW SETS UP. SPEEDS OF ONLY
AROUND 10 KTS WILL PRODUCE CONTINUED 2-3 FT SEAS...COMPRISED OF A
ENE WIND CHOP EARLY...BECOMING A SW WIND CHOP LATE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT A SOUTHWEST FLOW INITIALLY AS BERMUDA
HIGH PRESSURE PREVAILS AND A FRONT LURKS OFF TO THE NORTH WITH A
PIEDMONT TROUGH AS WELL. THE FRONT MOVES ACROSS LATE WEDNESDAY INTO
THURSDAY MORNING AS MOST IF NOT ALL WATERS WILL SEE NORTHEASTERLY
WINDS BY 1200 UTC THURSDAY. UNCERTAINTY REMAINS FOR THE REMAINDER OF
THE FORECAST AS SURFACE PRESSURE PATTERN SHOWS LOW PRESSURE DROPPING
TO THE SOUTH AND WINDS TURNING TO THE EAST. GOOD THING IS THE
STRENGTH OF THE LOW SHOULD REMAIN RELATIVELY WEAK SO DO NOT
ANTICIPATE ANY HEADLINES. THE STRONGEST WINDS SHOULD OCCUR WEDNESDAY
WITH 10-15 KNOTS. WAVEWATCH SEAS ARE REFLECTIVE OF THE WINDS AT
LEAST INITIALLY. HAD TO SCALE BACK LATER IN THE PERIOD BUT OVERALL
SEAS REMAIN BELOW FLAG CRITERIA AS WELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...RJD/HDL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 PM CDT MON APR 2 2012
.DISCUSSION...MINOR UPDATES TO TEMPERATURES AND PRECIPITATION.
ADJUSTED TEMPERATURES LOWER ONCE AGAIN...WITH HIGHS MAINLY IN THE
UPPER 40S TO LOWER 50S. CLOUD DECK IS SLOW TO ERODE FROM THE
WEST...THUS KEEPING TEMPERATURES DOWN. THE FAR WEST WILL LIKELY
SEE SUNSHINE IN THE NEXT HOUR OR TWO AS THE CLOUD SHIELD MOVES
SLOWLY EAST...THUS THE FAR WEST MAY SEE SOME MIDDLE 50S.
LATEST HIGH RESOLUTION RUC LIFTS CURRENT CONVECTION NORTHWARD
THROUGH THE AFTERNOON...AS THE ENTIRE SYSTEM TRACKS SLOWLY EAST.
LOWERED POPS OVER THE FAR SOUTHEAST...KEEPING HIGHEST POPS FROM
WESTERN MCINTOSH THROUGH STUTSMAN COUNTIES. ALSO MENTIONED
SCATTERED SPRINKLES INTO THE EVENING OVER CENTRAL NORTH DAKOTA.
THERE HAVE BEEN SOME SPRINKLES REACHING THE GROUND UNDER THE
ELEVATED REFLECTIVITIES ACROSS THE WEST.
&&
.AVIATION...TROUGH OF LOW PRESSURE EXTENDING NORTH THROUGH THE
EASTERN DAKOTAS WILL CONTINUE TO RESULT IN EXTENSIVE VFR
CLOUDINESS THROUGH THIS AFTERNOON ACROSS CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA. SHOULD SEE SKIES TRENDING TOWARDS SCT-
SKC AFTER 21Z WEST...THEN SCT-SKC CENTRAL 02-05Z. -SHRA WILL END
BY 20Z SOUTHWEST AND CENTRAL AROUND 00Z. LINE OF ENHANCED SHOWERS
AND THUNDERSTORMS AND MVFR CIGS FROM KMBG TO KJMS WILL SLOWLY LIFT
NORTH WITH TIME THIS AFTERNOON. WILL CONTINUE TO MENTION VCTS AT
KJMS THROUGH 01Z. STRONG NORTH WINDS WITH GUSTS BETWEEN 30-40KTS
EXPECTED AT KBIS AND KJMS THROUGH 23-00Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ020-
034>037-042-045>048-050-051.
WIND ADVISORY UNTIL 3 PM MDT THIS AFTERNOON FOR NDZ033-040-041-
043-044.
&&
$$
SHORT TERM...TWH
AVIATION...NH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
327 AM CDT MON APR 2 2012
.SHORT TERM...MAIN CHALLENGE WILL BE PRECIP/THUNDER CHANCES TODAY.
00Z MODELS INITIALIZED WITH MINIMAL ERRORS. GFS/ECMWF/GEM ALL
AGREE WITH TIMING WITH NAM FASTER. WILL SIDE WITH THE SLOWER
SOLUTIONS.
UPPER TROUGH ACROSS THE ROCKIES WILL BE NEAR THE EASTERN FA BY 12Z
TUESDAY. A COLD FRONT WILL SLOWLY PROPAGATE FROM WEST TO EAST
THROUGH THE REGION. MODELS INDICATE WEAK TO MODERATE INSTABILITY
(850MB CAPE AROUND 1000 J/KG) WILL ADVECT INTO THE SOUTHERN FA BY
12Z THIS MORNING...WITHIN WARM AIR ADVECTION REGIME. HRRR SUGGESTS
THUNDER TO DEVELOP ACROSS AN AREA FROM SOUTHEAST NORTH DAKOTA INTO
THE BEMIDJI AREA. DEEP LAYER SHEAR IS MARGINAL...BUT AN ISOLATED
SEVERE HAIL REPORT IS POSSIBLE. THIS ACTIVITY DIMINISHES BY
AFTERNOON AS 850MB FLOW WEAKENS. A BAND OF SHOWERS (MAYBE ISOLD
THUNDER) WILL LIKELY DEVELOP ALONG AN 850MB BAROCLINIC ZONE BY
NOON TO THE NORTH OF THE MORNING CONVECTIVE ACTIVITY (AROUND AN
AREA FROM VALLEY CITY TO HALLOCK). FOLLOWING GFS/ECMWF/GEM 850MB
FRONTOGENESIS...THIS BAND OF SHOWERS SHOULD GRADUALLY PROPAGATE TO
THE EAST/SOUTHEAST INTO THE OVERNIGHT HOURS. TIMED 60 POPS
ACCORDING TO THIS TIMING. THIS BAND OF FRONTOGENESIS WILL INTERACT
WITH PWATS 0.75 TO 1.00 INCH. GIVEN THE ABOVE FACTORS THINKING
AREAL QPF 0.50 INCH TO 1.00 INCH. WINDS WILL BECOME NORTH BEHIND
THE COLD FRONT...AND CLOSE TO ADVISORY CRITERIA. GIVEN CURRENT
MODEL 925MB WINDS SPEEDS OF 30-35 KNOTS...THINKING MOST AREAS WILL
BE JUST BELOW ADVISORY CRITERIA. STRONGEST COLD AIR ADVECTION
REMAINS WEST/SOUTH OF THE FA. MAX TEMPS SHOULD REMAIN IN THE 50S
CONSIDERING CONSIDERABLE CLOUD COVER.
RIDGING AFFECT THE REGION FOR THE REMAINDER OF THE PERIOD. THE
AIRMASS WILL CHANGE LITTLE...AND CONDITIONS SHOULD BE SIMILAR
EACH DAY.
.LONG TERM (THURSDAY-SUNDAY)...MODELS IN GOOD AGREEMENT WITH THE
EXTENDED TIME PERIOD AS 500MB RIDGING DOMINATES THE WEATHER
PATTERN OVER THE NORTHERN PLAINS FROM THE MIDDLE TO THE END OF THE
WEEK. AS THE RIDGING SHIFTS EAST SOUTHWESTERLY FLOW DEVELOPS AND
WILL BRING AN INCREASE OF SHOWER ACTIVITY BEGINNING FRIDAY
AFTERNOON. BEST CHC FOR PCPN WILL BE SATURDAY ASSOCIATED WITH
FROPA. TEMPS FOR THE PERIOD TO BE ABOVE NORMAL... WITH COOLER
TEMPS EXPECTED THIS NEXT WEEKEND AS CLOUDS INCREASE WITH CHC POPS.
&&
.AVIATION...MVFR CIGS EXPECTED TO DEVELOP THIS MORNING ALONG AND
EAST OF THE VALLEY. THESE CIGS WILL LIKELY LOWER INTO IFR RANGE BY
AFTERNOON. SCATTERED TSRA EXPECTED TO DEVELOP ALONG A LINE FROM
FARGO TO BEMIDJI AROUND SUNRISE. THIS ACTIVITY SHOULD
DIMINISH BY NOON...BUT A BAND OF SHOWERS WILL LIKELY DEVELOP FROM
VALLEY CITY TO THE NORTHEAST...AND THEN GRADUALLY MOVE EAST
THROUGH THE DAY. CIGS WILL REMAIN LOW INTO TONIGHT...CLEARING FROM
WEST TO EAST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG/JK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
927 PM EDT TUE APR 3 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE REGION TONIGHT...WITH
THUNDERSTORMS DEVELOPING UNTIL TOMORROW MORNING. HIGH PRESSURE
WILL GRADUALLY MOVE IN FROM THE NORTH THROUGH THE END OF THE
WEEK...WITH GRADUALLY COOLING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AIRMASS ACROSS OUR AREA REMAINS JUST SLIGHTLY UNSTABLE AND THIS IS
GENERALLY ALOFT AS BOUNDARY LAYER HAS COOLED/DRIED IN THE WAKE OF
EARLIER OUTFLOW BOUNDARY. A LINE OF SHOWERS AND THUNDERSTORMS IS
CONTINUING ALONG THE COLD FRONT BACK ACROSS CENTRAL ILLINOIS INTO
NORTHERN INDIANA...BUT SO FAR THESE HAVE HAD A TOUGH TIME
PROGRESSING EASTWARD. THE LATEST HRRR IS SHOWING THIS PCPN PUSHING
EAST INTO OUR NORTHERN AREAS THROUGH 06Z...BUT GIVEN TRENDS AND
MORE STABLE AIRMASS ACROSS OUR AREA...NOT SURE IF THAT WILL PAN
OUT. AS LOW OVER MISSOURI PUSHES EAST THROUGH THE OVERNIGHT
HOURS...WE SHOULD BEGIN TO MOISTEN UP A BIT MORE AND PERHAPS
DESTABILIZE ALOFT A LITTLE BETTER. WILL MAKE SOME DOWNWARD
ADJUSTMENTS TO POPS IN THE NEAR TERM AND BRING BETTER POPS IN FROM
THE SOUTHWEST LATER TONIGHT. SEVER THREAT SEEMS TO BE RATHER LOW
GIVEN BOTH WEAK SHEAR PROFILES AND WEAK INSTABILITY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE SOUTHERN HALF OF THE CWA WILL START THE DAY WEDNESDAY IN A
FAVORABLE CONVERGENT AREA FOR CONTINUED SHOWER AND THUNDERSTORM
DEVELOPMENT. THIS WILL DIMINISH AS THE SURFACE FRONT PUSHES SOUTH
OF THE FORECAST AREA DURING THE AFTERNOON...BEGINNING A PATTERN OF
NORTH WINDS AND COLD ADVECTION THAT WILL GO THROUGH THE END OF THE
WEEK. MOISTURE WILL REMAIN JUST SOUTH OF THE FORECAST AREA...AND
MAY ACTUALLY EDGE NORTH ENOUGH TO PRODUCE SOME PRECIPITATION IN
THE FAR SOUTH ON THURSDAY. THIS WILL BE POSSIBLE AS A WEAKENING
CLOSED UPPER LOW MOVES EAST INTO THE TENNESSEE VALLEY.
OVERALL...HOWEVER...A DRIER AND COOLER AIR MASS WILL BE THE RESULT
OF THIS SHIFT IN THE WEATHER PATTERN.
TEMPERATURES...THUS...SHOULD COOL THROUGH THE FORECAST PERIOD.
THIS WILL RESULT IN MIN TEMPERATURES GETTING VERY CLOSE TO
FREEZING ON THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
BEGINNING OF PERIOD WILL BE MARKED BY AN AMPLIFIED UPPER LEVEL FLOW
PATTERN. UPPER LOW THAT HAD BEEN TREKKING ACROSS THE MID SOUTH WILL
BE ABSORBED INTO AN EAST COAST TROUGH. SHARP RIDGING OVER THE PLAINS
WILL PLACE THE LOCAL AREA IN NORTHERLY FLOW ALOFT. AT THE SFC...HIGH
PRESSURE WILL BUILD SOUTHWARD FROM ONTARIO INTO THE GREAT LAKES.
THIS WILL LEAD TO DRY AND SEASONABLE CONDITIONS FOR FRIDAY. ON
FRIDAY NIGHT...THE SFC HIGH WILL BUILD OVERHEAD...LEADING TO CLEAR
SKIES AND LIGHT WINDS. FROST WILL BE A CONCERN OVER MUCH OF THE CWA
EXCEPT PERHAPS NORTHERN KY...AND THE TYPICAL COOLER LOCALES EAST OF
COLUMBUS MAY APPROACH FREEZING (THESE TEMPERATURES REPRESENT A
DOWNWARD ADJUSTMENT FROM THE PREVIOUS FORECAST). AS THE HIGH SLIDES
EAST OF THE AREA ON SATURDAY...WINDS WILL BECOME SOUTHERLY AND
PROMOTE TEMPERATURES TO RISE A LITTLE ABOVE NORMAL.
THE NEXT SHORT WAVE TROUGH TO APPROACH FROM THE ROCKIES WILL MAINLY
SERVE TO SQUASH THE UPPER RIDGE...WITH MOST OF THE ENERGY REMAINING
NORTH OF THE AREA. A SFC LOW WILL TRACK WELL NORTH INTO
CANADA...WITH A TRAILING COLD FRONT CROSSING THE AREA ON SUNDAY.
MODELS DISAGREE A LITTLE ON TIMING...BUT APPEARS TO BE MAINLY A
DAYTIME EVENT...SO DELAYED POPS A LITTLE FROM PREVIOUS FORECAST. IN
WESTERLY FLOW THROUGHOUT THE ATMOSPHERE...THE FRONT WILL BE MOISTURE
STARVED...SO MAINTAINED THE LOW CHANCE POPS. INSTBY WILL BE WEAK BUT
PRESENT (MORESO SOUTH)...SO KEPT THUNDER MENTION. AIRMASS CHANGE
BEHIND THE FRONT WILL BE MINIMAL AS WEAK SFC RIDING EXTENDS INTO THE
AREA BY SUNDAY NIGHT INTO EARLY MONDAY...WITH TEMPERATURES REMAINING
SLIGHTLY ABOVE NORMAL.
AS UPPER LEVEL GYRE FORMS OVER EASTERN CANADA...ANOTHER SHORTWAVE
TROUGH WILL ROTATE DOWN THROUGH THE AREA LATE MONDAY INTO TUESDAY.
THIS SYSTEMS WILL BE MOISTURE STARVED AS WELL...SO LIMITED FORECAST
TO CHANCE POPS. LEFT THUNDER MENTION OUT WITH LIMITED INSTBY AND
HIGHER THETA-E SUPPRESSED FAR TO OUR SOUTH. WHILE MODELS DIFFER WITH
TIMING AND EXACT FEATURES...THEY AGREE ON THE MORE SUBSTANTIAL
EFFECT FROM THIS SYSTEM...WHICH WILL BE THE COLDER AIR IT PULLS
SOUTHWARD INTO THE AREA. FORECAST HIGH TEMPERATURES ON TUESDAY ARE
ABOUT 10 DEGREES BELOW NORMAL.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
OUTFLOW FROM EARLIER CONVECTION THAT MOVED ACROSS CENTRAL OHIO IS
CONTINUING TO PUSH SOUTHWEST ACROSS MUCH OF OUR AREA. THIS HAS
HELPED STABILIZE US IN THE SHORT TERM OVER ALL BUT OUR FAR
SOUTHWEST. AS A RESULT...EXPECT MAINLY JUST SOME CIRRUS ACROSS THE
AREA THROUGH THIS EVENING. MEANWHILE...SCATTERED THUNDERSTORMS HAVE
DEVELOPED ACROSS CENTRAL ILLINOIS ALONG A COLD FRONT THAT STRETCHES
ACROSS NORTHERN INDIANA INTO NORTHERN OHIO. THIS COLD FRONT IS
FORECAST TO SAG SLOWLY SOUTH THROUGH THE OVERNIGHT HOURS AND INTO
WEDNESDAY MORNING. MODELS CONTINUE TO INDICATE THAT WESTERLY LOW
LEVEL FLOW AHEAD OF THE FRONT WILL BE ABLE TO ADVECT SOME BETTER
INSTABILITIES INTO OUR AREA THROUGH THE OVERNIGHT HOURS. THIS
WOULD LIKELY ALLOW FOR THE THUNDERSTORM ACTIVITY TO EXPAND
EASTWARD ALONG THE FRONT AND INTO OUR AREA THROUGH THE OVERNIGHT
HOURS. WITH THE SOUTHWARD PUSH OF THE FRONT...EXPECT THE BEST
CHANCE FOR PCPN/THUNDER TO BE ACROSS OUR SOUTHWEST FA...WITH
CHANCES DECREASING HEADING TO THE NORTH/EAST. WILL THEREFORE HIT
KCVG/KLUK THE HARDEST WITH PCPN FOR LATE TONIGHT INTO
WEDNESDAY MORNING. PCPN SHOULD TAPER OFF ACROSS THE SOUTH THROUGH
LATE MORNING...BUT GOOD CAA ON THE BACKSIDE OF THE FRONT COULD
LEAD TO A PERIOD OF SOME MVFR CIGS...BEFORE SOME DRIER AIR IS ABLE
TO WORK IN FROM THE NORTH LATE IN THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...JGL
SHORT TERM...HATZOS
LONG TERM...SNYDER
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 AM EDT MON APR 2 2012
.SYNOPSIS...
A COOLER AND DRIER AIR MASS ASSOCIATED WITH HIGH PRESSURE CENTERED
OVER HUDSON BAY WILL BE DIRECTED INTO THE AREA TODAY BEHIND
NORTHERLY WINDS...WHICH WILL BE RATHER GUSTY OVER THE EASTERN HALF
OF THE STATE. THE NEXT CHANCE OF RAIN WILL COME BY LATE TUESDAY
INTO EARLY WEDNESDAY...AS A WEAK AREA OF LOW PRESSURE MOVES
EASTWARD FROM THE OHIO VALLEY ACROSS THE NORTHERN MID-ATLANTIC
STATES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLIPPER LOW OVER SOUTHERN PA LATE THIS EVENING WILL CONTINUE TO
TRACK SE...PASSING OFF THE DELMARVA LATER TONIGHT. REGIONAL RADAR
MOSAIC SHOWING RAIN STILL FALLING ACROSS THE SOUTHERN THIRD OF PA
AT 03Z. HRRR AND RUC BOTH INDICATE THE LAST THE RAIN WILL EXIT
SOUTHERN PA BTWN 05Z-06Z.
CLEARING SKIES SHOULD DEVELOP LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN PA...AS MUCH DRIER AIR MASS OVERSPREADS THE STATE. LOW
LVL MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP
STRATO-CU LOCKED IN OVR THE N MTNS...WHILE DOWNSLOPING NORTHERLY
FLOW YIELDS MCLEAR SKIES SOUTH OF I-80 BY DAWN. LIGHT WINDS WILL
BECOME GUSTY FROM THE NW OVR THE ENTIRE REGION TONIGHT...AS
CLIPPER LOW INTENSIFIES OFF THE E COAST. THESE GUSTY WINDS HAVE
ALREADY DEVELOPED ACROSS THE NW MTNS AS OF 03Z AND BUFKIT
SOUNDINGS SUPPORT GUSTS TO ARND 20KTS LATER TONIGHT ACROSS MUCH OF
SOUTHERN PA.
POST-FRONTAL AIR MASS WILL BE ONLY SEASONABLY COOL AND AN ACTIVE
NW WIND WILL KEEP ATMOS MIXED OVERNIGHT...SO LOW TEMPS SHOULD
ACTUALLY BE A BIT ABV SEASONAL NORMS...RANGING FROM THE L30S NW
MTNS...TO ARND 40F SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY WILL BE BREEZY...DRIER AND A LITTLE COOLER AS NORTHERLY
WINDS SPREAD IN BEHIND THE DEPARTING FRONT AND THE HIGH TO OUR
NORTH BEGINS NOSING DOWN. ANY EARLY CLOUDS WILL YIELD TO PLENTY OF
SUNSHINE BY MID TO LATE MORNING. GEFS 850 TEMPS SUPPORT HIGH
TEMPS IN THE 50S. DESPITE THE DRY AIR AND GUSTY WINDS OVR EASTERN
PA ON MONDAY...THINKING IS TODAY/S RAINFALL WILL DAMPEN FINE FUELS
ENOUGH TO PRECLUDE A SIGNIFICANT WILDFIRE THREAT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROFFING ALONG THE APPALACHIANS AT THE START OF THE
PERIOD...AN EXTENSION OF A LARGE UPPER VORTEX OVER ERN CANADA...IS
FORECAST TO WEAKEN AS THE MAIN SHORT WAVE TROF SWINGS
OFFSHORE...ALLOWING HEIGHTS TO RISE TEMPORARILY ACROSS PA AND INTO
NEW ENGLAND. TROFFING WILL RETURN MIDWEEK AS ENERGY IN THE
ACTIVE NRN STREAM JET DROPS DOWN THE EAST SIDE OF THE UPPER RIDGE
OVER THE CENTRAL U.S.
THIS CENTRAL U.S. UPPER RIDGE/OMEGA BLOCK PATTERN WILL MAKE ONLY
SLOW PROGRESS EAST AS IT IS BOMBARDED BY NUMEROUS NRN AND SRN
STREAM WAVES AS WELL AS BEING IMPEDED BY THE ERN CANADA UPPER LOW.
THIS WILL SERVE TO KEEP PA IN SOME DEGREE OF NW FLOW THROUGH THE
REMAINDER OF THE LONG TERM PD. WHILE THIS WILL HELP SUPPORT THE DRY
FORECAST...ANY WAVES IN THE FLOW COULD BECOME FLIES IN THE OINTMENT
SO TO SPEAK. THOUGH AT THIS POINT NO OPPORTUNITIES FOR SIGNIFICANT
RAINFALL APPEAR LIKELY. THE NW FLOW WILL ALSO BRING COOLER...OR
RATHER CLOSE TO NORMAL...OR EVER SO SLIGHTLY BELOW NORMAL TEMPS FOR
THUR AND FRI BEFORE A WARM UP FOR NEXT WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WEAK FRONTAL SYSTEM AND WAVE OF LOW PRES CURRENTLY PUSHING SOUTH
OF THE PA/MD LINE AS OF 05Z. COSPA DATA DEPICTS SHOWERS EXITING
SRN PA BY 06Z. IR SATL SHOWS LOW CLOUDS MOVG SWD FROM NY COVERING
MUCH OF CENTRAL PA WITH CIGS GENERALLY IN THE MVFR CATG BTWN
1500-3000KFT AGL...WITH LCL CIGS BLW 1KFT AGL ACRS PTNS OF THE
ALLEGHENIES/LAUREL HIGHLANDS. THE REMAINDER OF THE PRE-DAWN HOURS
WILL BE CLOUDY WITH MAINLY MVFR CIGS AND PATCHY DZ...AS MSTR
PROFILES DRY OUT RAPIDLY ALOFT.
A DRIER NLY FLOW ASSOC WITH CANADIAN HIGH PRES SHOULD BRING
CLEARING TO THE NRN TIER BTWN 10-11Z AND 11-13Z IN THE CNTRL
AIRFIELDS BASED ON LINEAR EXTRAPOLATION OF BACK EDGE OF LOW CLOUD
DECK CROSSING LAKE ONTARIO. EXPECT DECREASING CLOUDS EARLY THIS
MORNING SHORTLY AFT SUNRISE WITH CLR SKIES AND WDSPRD VFR BY MID-
DAY. ANTICIPATE THE NLY WINDS TO INCREASE FROM MID MORNING THROUGH
THE AFTN ESPECIALLY OVR ERN SXNS WITH GUSTS BTWN 25-30KTS. WINDS
WILL SUBSIDE AFTER DARK AS HIGH PRES BUILDS OVER PA.
OUTLOOK...
TUE...VFR/MVFR WITH SHOWERS LATE.
WED...MVFR WITH A CHC OF SHOWERS EARLY...OTHERWISE VFR.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1133 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 1133 AM CDT/
SLOW MOVING COLD FRONT ACROSS OUR FAR WESTERN ZONES IS NEARLY
STATIONARY THIS MORNING AND THE SURFACE LOW BUILDS NORTHWARD OVER
THE CWA. EXPECT THIS FRONT TO REMAIN NEARLY STATIONARY INTO THE
EARLY AFTERNOON BEFORE FINALLY TRACKING EASTWARD MID AFTERNOON INTO
THE LATE EVENING. MEANWHILE STRATUS HAS FINALLY BEGUN TO RAPIDLY
ERODE ACROSS OUR NORTHEASTERN THIRD. TEMPERATURES RAPIDLY JUMPING
IN THE CLEAR AREA BETWEEN THESE STRATUS FIELDS WITH TEMPERATURES
ALREADY IN THE UPPER 70S INTO OUR EXTREME SOUTHEASTERN ZONES.
UPDATED TEMPERATURES ACROSS NW IA AND INTO THE I29 CORRIDOR WHERE
SKIES WILL REMAIN PREDOMINATELY CLEAR INTO THE AFTERNOON AND THETA E
ADVECTION IS PRETTY STRONG. COULD SEE ANOTHER DAY WELL INTO THE 80S
IN PARTS OF THIS AREA. ALSO UPDATED TO SLOW DOWN THE DEVELOPMENT OF
THE ISOLATED SHOWERS/SPRINKLES WITH THE SLOWER FRONTAL PROGRESSION.
AHEAD OF THE FRONT...STRONG CAP LOOKS TO DOMINATE OUR EASTERN HALF
WHICH WILL MAKE THUNDERSTORM DEVELOPMENT PROBLEMATIC THROUGH AT
LEAST LATE THIS AFTERNOON. STILL...CANNOT RULE OUT SOME ISOLATED
ELEVATED THUNDERSTORM DEVELOPMENT IN THE LATE AFTERNOON AND EARLY
EVENING ACROSS OUR FAR EASTERN AREAS. WITH GOOD
INSTABILITY...ENHANCEMENT OF THE LOW LEVEL JET AND GOOD MID LEVEL
LAPSE RATES A FEW MARGINALLY SEVERE STORMS ARE A POSSIBILITY IF
DEVELOPMENT DOES OCCUR.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
IFR/MVFR STRATUS AND AREAS OF FOG ACROSS THE EASTERN AND NORTH
CENTRAL ZONES QUICKLY LIFTING LATE THIS MORNING. VISIBILITY AND
CEILINGS WILL IMPROVE TO VFR FROM WEST TO EAST IN THIS AREA INTO THE
EARLY AFTERNOON. MEANWHILE A SLOW MOVING FRONT ACROSS CENTRAL SOUTH
DAKOTA WILL GRADUALLY TRACK EASTWARD ACROSS THE FORECAST AREA
THROUGH THE LATE EVENING. STRATUS WILL FOLLOW BEHIND THIS FRONT
ALONG WITH A SMALL POTENTIAL FOR LIGHT RAIN SHOWERS OR SPRINKLES.
WINDS WILL FLIP TO THE NORTH NORTHWEST BEHIND THE FRONT AND BECOME
QUITE STRONG THIS AFTERNOON AND EVENING...AROUND 25 TO 35 KT WITH
POSSIBLY A FEW GUSTS AROUND 40 KT IN THE JAMES VALLEY AND WESTWARD.
ELSEWHERE...WINDS WILL BECOME BREEZY BEHIND THE FRONT THIS EVENING
AND OVERNIGHT. THERE IS A SMALL POTENTIAL FOR SOME THUNDERSTORM
DEVELOPMENT THIS EVENING ACROSS PARTS OF NORTHWEST IOWA TOWARDS
SOUTH CENTRAL MINNESOTA.
&&
.PREV DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
636 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
ONCE AGAIN...STRATUS IS A CONCERN...AT LEAST THROUGH OUR NORTHERN
AND EASTERN ZONES. WIDESPREAD LIFR TO IFR CONDITIONS WILL BE FOUND
ALONG AND EAST OF AROUND A HURON SD...TO SIOUX FALLS...TO JUST EAST
OF SIOUX CITY LINE...AT LEAST THROUGH LATE MORNING. SOME OF THIS
STRATUS MAY LINGER RIGHT INTO EARLY AFTERNOON BEFORE MIXING OUT TO A
HIGHER LEVEL. DUE TO BREEZY WINDS...THE VISIBILITIES WILL NOT BE AS
BAD THIS MORNING AS IN PREVIOUS MORNINGS. BUT STILL MANY CEILINGS
WILL BE AT OR BELOW 500 FEET AGL. IT IS PROBLEMATIC WHETHER THE VERY
LOW CEILINGS WILL MAKE IT INTO THE KHON TAF. AS OF THIS TIME...
VARIOUS MODELS ARE HINTING AT SOME TEMPORARY STRATUS DEVELOPMENT AT
HURON A LITTLE LATER THIS MORNING...BUT A BIT HIGHER AT JUST INSIDE
THE MVFR CATEGORY. THIS WILL HAVE TO BE MONITORED CLOSELY. IN
ADDITION...ALL INDICATIONS ARE THAT THE STRATUS WILL NOT MAKE IT TO
KSUX. BUT WOULD NOT BE SURPRISED TO SEE A FEW SHREDS OF STRATUS IN
THE SCATTERED CATEGORY AFTER SUNRISE.
THE COLD FRONT WILL ADVANCE ACROSS OUR SD COUNTIES VERY SLOWLY
TODAY...AND SLOWED DOWN THE WIND SHIFT AT KFSD AND KSUX. SOME MVFR
CEILINGS MAY BE FOUND IN OUR WESTERN ZONES BEHIND THE FRONT ALL
AFTERNOON WITH LIGHT SHOWERS...WHICH WILL LIKELY IMPACT THE KHON
TAF. MVFR CEILINGS WILL PROBABLY THEN WORK THEIR WAY FROM WEST TO
EAST TONIGHT AND ENCOMPASS MOST OF THE FORECAST AREA IN DOING SO.
NORTHERLY WINDS WILL ALSO BE STRONG BEHIND THE FRONT...MAINLY ALONG
AND WEST OF THE JAMES RIVER VALLEY...AVERAGING 25 TO 35 KNOTS...WITH
SOME GUSTS OF 40 TO 45 KNOTS AS YOU APPROACH CENTRAL SD. THE WINDS
WILL DECREASE SOME TONIGHT. LASTLY...IT WILL BECOME QUITE WARM AGAIN
TODAY THROUGHOUT NORTHWEST IOWA. THIS HEATING MAY BE ENOUGH TO BREAK
CAPPING IN THOSE ZONES PRODUCING AN ISOLATED LATE AFTERNOON OR EARLY
EVENING THUNDERSTORM. /MJF
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
500 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
EXPECT REDEVELOPMENT OF STRATUS/FOG OVER NORTHEAST HALF OF THE AREA
THROUGH THE REMAINDER OF TONIGHT/EARLY MONDAY. POTENTIAL FOR LIFR
VISIBILITY...ESPECIALLY IN HIGHER ELEVATIONS ACROSS SOUTHWEST MN AS
STRATUS CURRENTLY DEVELOPING ACROSS NORTHERN IOWA ADVECTS INTO OUR
FORECAST AREA ON PERSISTENT EAST-SOUTHEAST LOW LEVEL FLOW. THESE
IFR-LIFR CONDITIONS EXPECTED TO ADVECT WESTWARD THROUGH INTERSTATE
29 CORRIDOR AFTER 09Z-10Z...WITH IFR-LIFR CONDITIONS PERSISTING
THROUGH 14Z-15Z. WHILE VISIBILITY EXPECTED TO IMPROVE THEREAFTER...
CONTINUED EAST-SOUTHEAST FLOW WILL LIKELY LOCK STRATUS IN PLACE INTO
THE EARLY-MID AFTERNOON.
LATEST MODELS SLOWER WITH EASTWARD PUSH OF COLD FRONT...WHICH WILL
BE NEEDED TO COMPLETELY SCOUR OUT THE LOW LEVEL MOISTURE. BEHIND THE
FRONT...WESTERN AREAS WILL SEE INCREASING NORTHERLY WINDS BEGIN TO
GUST OVER 25KTS BY 14Z-16Z...WITH SCATTERED LIGHT SHOWERS ALONG WITH
BROKEN MVFR CEILINGS MORE LIKELY IN POST-FRONTAL AIRMASS THAN AHEAD
OF THE BOUNDARY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
519 PM CDT MON APR 2 2012
.UPDATE...
A QUICK UPDATE WAS SENT TO REMOVE WW127...THE SEVERE THUNDERSTORM
WATCH THAT COVERED SOME OF THE EASTERN NORTH TEXAS UNTIL 7 PM.
SHOWERS AND THUNDERSTORMS NORTHEAST OF A SHERMAN TO SULPHUR
SPRINGS LINE WILL CONTINUE TO MOVE NORTHEAST AND SEVERE WEATHER
IS NOT EXPECTED TO DEVELOP ACROSS THE AREA PREVIOUSLY IN WW127.
OUR EYES WILL NOW BE TRAINED ALONG THE DRYLINE WHERE ACTIVITY IS
EXPECTED TO DEVELOP DURING THE NEXT HOUR.
58
&&
.PREV DISCUSSION... /ISSUED 307 PM CDT MON APR 2 2012/
MAIN UPPER LOW FEATURE SITS ACROSS CENTRAL NEW MEXICO. WEAK LOBE
THAT WAS NEAR TX COAST YESTERDAY HAS ROTATED NORTH AND SITS OVER
THE DFW METROPLEX. CIRCULATION AROUND THE WEAK LOW AND ASSOCIATED
SHORT WAVE HAS FIRED OFF SEVERE STORMS IN EASTERN NORTH
TEXAS...BUT AS THIS SYSTEM MOVES ON NORTH WE FEEL THAT THE DRY
LINE WILL BECOME THE MAIN PLAYER FOR TONIGHT AND TOMORROW.
GUIDANCE AGREES ON A GENERAL SOLUTION OF THE UPPER LOW PUSHING
EAST AND THEN NORTHEAST TO LIE OVER THE TX/OK PANHANDLES ON
TUESDAY. THE UPPER LOW MOVEMENT PUSHES THE DRY LINE ACROSS NORTH
TEXAS ON TUESDAY AS WELL. THE DISAGREEMENT IS ABOUT HOW
CONVECTION WILL EVOLVE WITH THE SYSTEM.
THE LATEST RUC ACTIVATES THE DRY LINE EARLY THIS EVENING. THE NAM
INITIATES DRY LINE CONVECTION WELL AFTER MIDNIGHT AS DOES THE
LATEST HRRR. WITH SOME CU ALREADY DEVELOPING WEST OF THE
CWA...WILL STICK WITH OUR PREVIOUS SOLUTION WHICH AGREES WITH THE
RUC AND THE GFS FOR DRY LINE CONVECTION THIS AFTERNOON/EVENING
MOVING INTO NORTHWEST COUNTIES.
EITHER CONVECTION WILL MAINTAIN IN SOME FORM OVERNIGHT AND
REINVIGORATE TOMORROW WITH DAYTIME HEATING...OR IT MAY DIE OUT
AND REGENERATE TOMORROW. EITHER WAY...WE HAVE HIGHER CONFIDENCE
OF A LINEAR FEATURE DEVELOPING DURING THE DAY TOMORROW AS THE DRY
LINE PUSHES EAST. WITH STEEP LAPSE RATES LARGE HAIL AND DAMAGING
WINDS ARE LIKELY TO OCCUR. STORMS SHOULD SWEEP EAST OF THE AREA
BY LATE EVENING OR EARLY WEDNESDAY MORNING...AND POPS END SUNRISE
WEDNESDAY. THE NAM IS AN OUTLIER...HOLDING THE DRY LINE BACK
ABOUT 8 HOURS BEHIND THE GFS...AND IF THIS OCCURS WE WOULD HAVE
TO ADD POPS FOR WEDNESDAY MORNING.
SHORT WAVE RIDGING MOVES IN WEDNESDAY AFTERNOON...AND NORTH TX
SHOULD REMAIN DRY THROUGH SUNDAY MORNING...WHEN A NEW FRONT IS
EXPECTED TO DROP INTO THE AREA AND INCREASE THE POPS A BIT. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 81 54 80 55 / 40 60 40 5 0
WACO, TX 67 79 54 83 55 / 20 60 30 5 0
PARIS, TX 65 79 59 81 54 / 20 50 60 10 0
DENTON, TX 65 79 54 78 54 / 40 60 30 5 0
MCKINNEY, TX 66 81 54 80 55 / 30 60 40 5 0
DALLAS, TX 66 82 55 81 55 / 30 60 40 5 0
TERRELL, TX 66 80 60 80 55 / 20 60 50 10 0
CORSICANA, TX 67 81 61 81 55 / 20 60 50 10 0
TEMPLE, TX 67 78 58 84 55 / 20 60 30 5 0
MINERAL WELLS, TX 64 77 53 81 52 / 50 40 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
307 PM CDT MON APR 2 2012
.DISCUSSION...
MAIN UPPER LOW FEATURE SITS ACROSS CENTRAL NEW MEXICO. WEAK LOBE
THAT WAS NEAR TX COAST YESTERDAY HAS ROTATED NORTH AND SITS OVER
THE DFW METROPLEX. CIRCULATION AROUND THE WEAK LOW AND ASSOCIATED
SHORT WAVE HAS FIRED OFF SEVERE STORMS IN EASTERN NORTH
TEXAS...BUT AS THIS SYSTEM MOVES ON NORTH WE FEEL THAT THE DRY
LINE WILL BECOME THE MAIN PLAYER FOR TONIGHT AND TOMORROW.
GUIDANCE AGREES ON A GENERAL SOLUTION OF THE UPPER LOW PUSHING
EAST AND THEN NORTHEAST TO LIE OVER THE TX/OK PANHANDLES ON
TUESDAY. THE UPPER LOW MOVEMENT PUSHES THE DRY LINE ACROSS NORTH
TEXAS ON TUESDAY AS WELL. THE DISAGREEMENT IS ABOUT HOW
CONVECTION WILL EVOLVE WITH THE SYSTEM.
THE LATEST RUC ACTIVATES THE DRY LINE EARLY THIS EVENING. THE NAM
INITIATES DRY LINE CONVECTION WELL AFTER MIDNIGHT AS DOES THE
LATEST HRRR. WITH SOME CU ALREADY DEVELOPING WEST OF THE
CWA...WILL STICK WITH OUR PREVIOUS SOLUTION WHICH AGREES WITH THE
RUC AND THE GFS FOR DRY LINE CONVECTION THIS AFTERNOON/EVENING
MOVING INTO NORTHWEST COUNTIES.
EITHER CONVECTION WILL MAINTAIN IN SOME FORM OVERNIGHT AND
REINVIGORATE TOMORROW WITH DAYTIME HEATING...OR IT MAY DIE OUT
AND REGENERATE TOMORROW. EITHER WAY...WE HAVE HIGHER CONFIDENCE
OF A LINEAR FEATURE DEVELOPING DURING THE DAY TOMORROW AS THE DRY
LINE PUSHES EAST. WITH STEEP LAPSE RATES LARGE HAIL AND DAMAGING
WINDS ARE LIKELY TO OCCUR. STORMS SHOULD SWEEP EAST OF THE AREA
BY LATE EVENING OR EARLY WEDNESDAY MORNING...AND POPS END SUNRISE
WEDNESDAY. THE NAM IS AN OUTLIER...HOLDING THE DRY LINE BACK
ABOUT 8 HOURS BEHIND THE GFS...AND IF THIS OCCURS WE WOULD HAVE
TO ADD POPS FOR WEDNESDAY MORNING.
SHORT WAVE RIDGING MOVES IN WEDNESDAY AFTERNOON...AND NORTH TX
SHOULD REMAIN DRY THROUGH SUNDAY MORNING...WHEN A NEW FRONT IS
EXPECTED TO DROP INTO THE AREA AND INCREASE THE POPS A BIT. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 81 54 80 55 / 40 60 40 5 0
WACO, TX 67 79 54 83 55 / 20 60 30 5 0
PARIS, TX 65 79 59 81 54 / 20 50 60 10 0
DENTON, TX 65 79 54 78 54 / 40 60 30 5 0
MCKINNEY, TX 66 81 54 80 55 / 30 60 40 5 0
DALLAS, TX 66 82 55 81 55 / 30 60 40 5 0
TERRELL, TX 66 80 60 80 55 / 20 60 50 10 0
CORSICANA, TX 67 81 61 81 55 / 20 60 50 10 0
TEMPLE, TX 67 78 58 84 55 / 20 60 30 5 0
MINERAL WELLS, TX 64 77 53 81 52 / 50 40 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
635 AM CDT MON APR 2 2012
.AVIATION...
AN MCS PROPAGATING UP THE COASTAL PLAIN FROM MATAGORDA BAY WILL
LIKELY AFFECT THE AIRPORTS FROM KCXO SOUTH TO THE COAST THIS
MORNING THROUGH 15Z. GIVEN THE UNSTABLE AIR MASS AND THE LOCATION
OF THE STRONGEST WINDS AT 1130Z...INDICATED WIND GUSTS TO 35 KNOTS
POSSIBLE FOR KLBX AND KGLS. HOWEVER...MAY NEED TO ADJUST THESE
FURTHER INLAND.
THE MODEL FORECASTS DIFFERED FOR TODAY. THE 4 KM NCEP WRF
INITIALIZED AND HAS HANDLED THE MCS WELL THIS MORNING. COMBINED
THE WRF AND RUC FOR THE THUNDERSTORM FORECAST FOR TODAY. OUTSIDE
OF STORMS...VFR IS EXPECTED THIS AFTERNOON ALONG WITH BREEZY
WINDS.
MVFR IS EXPECTED TO DEVELOP BY AROUND 06Z INLAND AND AFTER 03Z
TOWARD AND ALONG THE COAST. IFR IS POSSIBLE MAINLY OVERNIGHT
TONIGHT...ESPECIALLY IF A GIVEN LOCATION RECEIVES RAINFALL TODAY.
40
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT MON APR 2 2012/
DISCUSSION...
A WEAK UPPER LEVEL CIRCULATION WAS SPINNING NORTH OF MATAGORDA BAY
THIS MORNING. THIS FEATURE WILL SLOWLY MOVE NORTH NORTHEAST INTO
NORTHWEST LOUISIANA BY EVENING. ANOTHER UPPER LEVEL DISTURBANCE
OVER SOUTH TEXAS IS TRIGGERING SHOWERS AND THUNDERSTORMS OVER
SOUTH TEXAS AND THE MIDDLE TEXAS COAST. THIS DISTURBANCE IS MOVING
EAST AND THE ASSOCIATED PRECIP SHOULD BEGIN TO MOVE OVER PARTS OF
THE CWA BY 5 AM. MODELS ARE NOT DOING A GREAT JOB WITH THE SMALL
SCALE DETAILS AND SHORT TERM GUIDANCE HAS INITIALIZED POORLY. THAT
SAID...FEEL THE DEEPER MOISTURE WILL REMAIN EAST OF THE UPPER
CIRCULATION NORTH OF MATAGORDA BAY. BEST RAIN CHANCES SHOULD LIE
TO THE EAST OF THE I-45 CORRIDOR AND SOUTH OF HWY 105. THE SYSTEM
WILL STRENGTHEN THIS AFTERNOON AND HEAVIER RAIN WILL BEGIN TO
DEVELOP AND HEAD TOWARD LOUISIANA. IF THE SYSTEM TRACKS FURTHER
WEST THAN CURRENTLY FCST...SOME OF THE MORE ORGANIZED HEAVIER RAIN
WILL ALSO SHIFT WEST AND INTO HOUSTON.
LOOKING SOUTH...THE LINE OF STORMS OVER SOUTH TEXAS IS MAKING
STEADY PROGRESS EAST THIS MORNING. SHORT TERM GUIDANCE IS WELL
BEHIND THE CURVE WITH THE PLACEMENT OF THE PRECIP. THE 06Z RUC IS
BEGINNING TO CATCH ON AND IT BRINGS A WEAK LINE OF SHOWERS INTO
THE REGION...WEST OF I-45 BY 15Z. THE 4KM WRF SEEMS TO BE DOING A
GOOD JOB WITH THIS AREA OF CONVECTION (COMPLETELY MISSED THE
PRECIP OVER LOUISIANA). THE WRF BRINGS THIS LINE OF STORMS
INTO AND ACROSS SOUTHEAST TEXAS THIS MORNING...EXITING THE THE
REGION BY 19Z. WILL HEDGE MY BETS AND GO WITH CHANCE POPS SOUTH
AND SLIGHT CHANCE NORTH. WILL WATCH TRENDS AND POPS MAY BE NUDGED
UPWARD LATER THIS MORNING IF TRENDS WARRANT. SPC HAS OUTLOOKED THE
EXTREME NORTHERN PORTION OF SE TX IN SLIGHT RISK FOR THIS
AFTERNOON AND EVENING. FCST SOUNDINGS SHOW A GREAT DEAL OF
INSTABILITY (CAPE ABOVE 3000 AND LI`S AROUND -10)...BUT THERE IS
STILL SOME WEAK CAPPING TO OVERCOME. THE PROBABILITY OF OCCURRENCE
SHOULD REMAIN SLIGHT BUT THERE IS SOME POTENTIAL FOR STORMS TO
PRODUCE DAMAGING WINDS AND LARGE HAIL. THE THREAT AREA IS NORTH OF
A BRENHAM TO HUNTSVILLE TO CLEVELAND LINE.
THERE SHOULD BE A BREAK IN THE PRECIP TONIGHT AS THE MORNING
SYSTEM IS EAST OF THE REGION AND THE NEXT STRONG UPPER LEVEL
SYSTEM IS STILL OVER NEW MEXICO. THE UPPER LEVEL LOW OUT WEST WILL
MOVE NORTHEAST ON TUESDAY. NAM AND GFS DIFFER WITH MOISTURE
PROFILES BUT CAPPING IS WEAK AND UPPER LEVEL WINDS BECOME
INCREASINGLY DIVERGENT. WILL GO WITH HIGH END CHANCE POPS FOR
TUESDAY/TUES NIGHT. NOT SURE WHEN THINGS WILL CLEAR. THE
ECMWF...NAM AND CANADIAN HOLD ONTO THE PRECIP THROUGH WEDNESDAY
MORNING WHILE THE GFS CLEARS THINGS OUT RATHER QUICKLY. PREFER THE
SLOWER CLEARING SINCE THE DRY LINE/WEAK FRONT NEVER REALLY CLEARS
THE COAST. THE UPPER LEVEL LOW WILL BE EAST OF THE REGION ON
THURSDAY AND AN UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY OVER THE
SOUTHERN PLAINS. PRECIP SHOULD REMAIN NORTH AND WEST OF THE REGION
THURSDAY THROUGH SATURDAY WITH ANOTHER WARM UP UNDERWAY. MAX TEMPS
TOWARD THE END OF THE WEEK WILL BE BACK INTO THE MID/UPPER 80S. 43
MARINE...
AS AN UPPER LOW MOVES ACROSS THE INLAND AREAS...THUNDERSTORMS WILL
BE POSSIBLE TODAY OVER THE BAYS AND COASTAL WATERS. ALTHOUGH THE
FORECAST MODELS DIFFERED...THERE WAS ENOUGH SIMILARITIES TO SUGGEST
MODERATE ONSHORE WINDS WILL AFFECT THE MARINE AREAS TODAY THROUGH
TUESDAY. A COLD FRONT SHOULD APPROACH THE COAST FROM THE NORTHWEST
LATE TUESDAY AND EARLY WEDNESDAY MORNING. FOR NOW IT APPEARS THAT
THE FRONT MAY WELL STAY INLAND OR MOVE JUST OFFSHORE BEFORE
RETURNING BACK TO THE NORTH LATE WEDNESDAY AND THURSDAY. AM
EXPECTING ONSHORE WINDS TO THEN RETURN AND PERSIST THROUGH THE END
OF THE WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 70 80 64 82 / 30 20 50 50 10
HOUSTON (IAH) 84 71 83 67 85 / 30 20 50 50 20
GALVESTON (GLS) 81 73 81 71 81 / 40 20 50 50 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
408 AM CDT MON APR 2 2012
.DISCUSSION...
A WEAK UPPER LEVEL CIRCULATION WAS SPINNING NORTH OF MATAGORDA BAY
THIS MORNING. THIS FEATURE WILL SLOWLY MOVE NORTH NORTHEAST INTO
NORTHWEST LOUISIANA BY EVENING. ANOTHER UPPER LEVEL DISTURBANCE
OVER SOUTH TEXAS IS TRIGGERING SHOWERS AND THUNDERSTORMS OVER
SOUTH TEXAS AND THE MIDDLE TEXAS COAST. THIS DISTURBANCE IS MOVING
EAST AND THE ASSOCIATED PRECIP SHOULD BEGIN TO MOVE OVER PARTS OF
THE CWA BY 5 AM. MODELS ARE NOT DOING A GREAT JOB WITH THE SMALL
SCALE DETAILS AND SHORT TERM GUIDANCE HAS INITIALIZED POORLY. THAT
SAID...FEEL THE DEEPER MOISTURE WILL REMAIN EAST OF THE UPPER
CIRCULATION NORTH OF MATAGORDA BAY. BEST RAIN CHANCES SHOULD LIE
TO THE EAST OF THE I-45 CORRIDOR AND SOUTH OF HWY 105. THE SYSTEM
WILL STRENGTHEN THIS AFTERNOON AND HEAVIER RAIN WILL BEGIN TO
DEVELOP AND HEAD TOWARD LOUISIANA. IF THE SYSTEM TRACKS FURTHER
WEST THAN CURRENTLY FCST...SOME OF THE MORE ORGANIZED HEAVIER RAIN
WILL ALSO SHIFT WEST AND INTO HOUSTON.
LOOKING SOUTH...THE LINE OF STORMS OVER SOUTH TEXAS IS MAKING
STEADY PROGRESS EAST THIS MORNING. SHORT TERM GUIDANCE IS WELL
BEHIND THE CURVE WITH THE PLACEMENT OF THE PRECIP. THE 06Z RUC IS
BEGINNING TO CATCH ON AND IT BRINGS A WEAK LINE OF SHOWERS INTO
THE REGION...WEST OF I-45 BY 15Z. THE 4KM WRF SEEMS TO BE DOING A
GOOD JOB WITH THIS AREA OF CONVECTION (COMPLETELY MISSED THE
PRECIP OVER LOUISIANA). THE WRF BRINGS THIS LINE OF STORMS
INTO AND ACROSS SOUTHEAST TEXAS THIS MORNING...EXITING THE THE
REGION BY 19Z. WILL HEDGE MY BETS AND GO WITH CHANCE POPS SOUTH
AND SLIGHT CHANCE NORTH. WILL WATCH TRENDS AND POPS MAY BE NUDGED
UPWARD LATER THIS MORNING IF TRENDS WARRANT. SPC HAS OUTLOOKED THE
EXTREME NORTHERN PORTION OF SE TX IN SLIGHT RISK FOR THIS
AFTERNOON AND EVENING. FCST SOUNDINGS SHOW A GREAT DEAL OF
INSTABILITY (CAPE ABOVE 3000 AND LI`S AROUND -10)...BUT THERE IS
STILL SOME WEAK CAPPING TO OVERCOME. THE PROBABILITY OF OCCURRENCE
SHOULD REMAIN SLIGHT BUT THERE IS SOME POTENTIAL FOR STORMS TO
PRODUCE DAMAGING WINDS AND LARGE HAIL. THE THREAT AREA IS NORTH OF
A BRENHAM TO HUNTSVILLE TO CLEVELAND LINE.
THERE SHOULD BE A BREAK IN THE PRECIP TONIGHT AS THE MORNING
SYSTEM IS EAST OF THE REGION AND THE NEXT STRONG UPPER LEVEL
SYSTEM IS STILL OVER NEW MEXICO. THE UPPER LEVEL LOW OUT WEST WILL
MOVE NORTHEAST ON TUESDAY. NAM AND GFS DIFFER WITH MOISTURE
PROFILES BUT CAPPING IS WEAK AND UPPER LEVEL WINDS BECOME
INCREASINGLY DIVERGENT. WILL GO WITH HIGH END CHANCE POPS FOR
TUESDAY/TUES NIGHT. NOT SURE WHEN THINGS WILL CLEAR. THE
ECMWF...NAM AND CANADIAN HOLD ONTO THE PRECIP THROUGH WEDNESDAY
MORNING WHILE THE GFS CLEARS THINGS OUT RATHER QUICKLY. PREFER THE
SLOWER CLEARING SINCE THE DRY LINE/WEAK FRONT NEVER REALLY CLEARS
THE COAST. THE UPPER LEVEL LOW WILL BE EAST OF THE REGION ON
THURSDAY AND AN UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY OVER THE
SOUTHERN PLAINS. PRECIP SHOULD REMAIN NORTH AND WEST OF THE REGION
THURSDAY THROUGH SATURDAY WITH ANOTHER WARM UP UNDERWAY. MAX TEMPS
TOWARD THE END OF THE WEEK WILL BE BACK INTO THE MID/UPPER 80S. 43
&&
MARINE...
AS AN UPPER LOW MOVES ACROSS THE INLAND AREAS...THUNDERSTORMS WILL
BE POSSIBLE TODAY OVER THE BAYS AND COASTAL WATERS. ALTHOUGH THE
FORECAST MODELS DIFFERED...THERE WAS ENOUGH SIMILARITIES TO SUGGEST
MODERATE ONSHORE WINDS WILL AFFECT THE MARINE AREAS TODAY THROUGH
TUESDAY. A COLD FRONT SHOULD APPROACH THE COAST FROM THE NORTHWEST
LATE TUESDAY AND EARLY WEDNESDAY MORNING. FOR NOW IT APPEARS THAT
THE FRONT MAY WELL STAY INLAND OR MOVE JUST OFFSHORE BEFORE
RETURNING BACK TO THE NORTH LATE WEDNESDAY AND THURSDAY. AM
EXPECTING ONSHORE WINDS TO THEN RETURN AND PERSIST THROUGH THE END
OF THE WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 70 80 64 82 / 20 20 50 50 10
HOUSTON (IAH) 84 71 83 67 85 / 30 20 50 50 20
GALVESTON (GLS) 81 73 81 71 81 / 40 20 50 50 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1130 PM CDT SUN APR 1 2012
.DISCUSSION...
SEE AVIATION FOR 06Z TAFS.
&&
.AVIATION...
THE MODERATE PRESSURE GRADIENT ACROSS SOUTH CENTRAL TEXAS WILL
INCREASE THROUGH MONDAY...IN ADVANCE OF A STORM SYSTEM THAT
WILL BRING INCREASING CHANCES OF RAIN LATE MONDAY THROUGH
TUESDAY. ISOLATED SHRA AND TSRA WILL CONTINUE OVER THE
SOUTHWEST TO SOUTH PART OF SOUTH CENTRAL TEXAS FOR THE
NEXT FEW HOURS. CIGS WILL CONTINUE TO FORM AROUND 1 THSD
TO 2 THSD FT FROM KAUS TO KSAT AND VCNTY OF KDRT AROUND
OR AFTER 09Z TONIGHT. CIGS OF 500 TO 900 FT OVC ARE POSSIBLE
VCNTY OF KAUS TO KSAT FROM 07Z TO 16Z MONDAY. PATCHY FOG MAY
DEVELOP WITH VSBYS 3 TO 6 MILES IN FOG/HAZE. CIGS WILL BECOME
1 THSD TO 2 THSD BKN TO OVC AFTER 16Z MONDAY...AND THEN INCREASE
TO CIGS 3 THSD TO 5 THSD BKN AFTER 19Z MONDAY AFTERNOON.
SOUTH AND SOUTHEAST WINDS NEAR 10 KNOTS WILL PICKUP TO
15 TO 20 KNOTS MONDAY...IN ADVANCE OF A STORM SYSTEM...THAT
WILL BRING INCREASING CHANCES OF SHOWERS OR THUNDERSTORMS TO
SOUTH CENTRAL TEXAS TAF SITES ON MONDAY NIGHT THROUGH TUESDAY.
MVFR CIGS WILL FORM OVER SOUTH CENTRAL TEXAS MONDAY NIGHT AFTER
03Z AROUND 1 THSD TO 2 THSD FT OVC. THE STORM SYSTEM THAT
BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS LATE MONDAY
THROUGH TUESDAY IS FORECAST TO MOVE TO THE TEXAS PANHANDLE
AND WESTERN OK TUESDAY...AND THEN MOVE EAST LATE TUESDAY THROUGH
WEDNESDAY. AS THE LOW TRACKS EAST...NORTH OF SOUTH CENTRAL TEXAS
TUESDAY NIGHT AND WEDNESDAY...SCATTERED WRAP AROUND CLOUDS COULD
IMPACT THE SOUTH CENTRAL TEXAS TAF SITES...AS MORE PREVAILING WEST
TO NORTHWEST SFC WINDS DEVELOP...IN A PATTERN SIMILAR TO THE
WEATHER IN MARCH.
&&
.PREV DISCUSSION... /ISSUED 906 PM CDT SUN APR 1 2012/
UPDATE...
RAISED POPS THROUGH 06Z OUT WEST.
DISCUSSION...
STORMS WHICH ORIGINATED EARLIER THIS AFTERNOON ACROSS THE
SERRANIAS DEL BURRO HAVE MADE GOOD EASTWARD PROGRESSION OVER THE
LAST FEW HOURS INTO THE RIO GRANDE PLAINS. THE STRONGEST
THUNDERSTORMS IN THIS COMPLEX HAVE PRODUCED SMALL HAIL (PEA TO
NEAR HALF-INCH)...AND COULD SEE ANOTHER FEW ROUNDS OF HAIL
(POSSIBLY REACHING SEVERE LEVELS) THIS EVENING AS THE STORMS PULSE.
LATEST RUC ANALYSIS SUGGEST THAT THESE STORMS WILL CONTINUE TO
PUSH EASTWARD THROUGH THE NEXT FEW HOURS BEFORE DISSIPATING.
HOWEVER...MODELS TYPICALLY HAVE A HARD TIME WITH MESOSCALE
CONVECTIVE SYSTEMS COMING OFF OF THE MEXICAN MOUNTAINS AS FAR AS
INTENSITY AND LONGEVITY...SO ADDITIONAL UPDATES MAY BE NEEDED.
PREV DISCUSSION... /ISSUED 704 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE UPDATED AVIATION DISCUSSION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS SFC LOW PRESSURE CONTINUES TO
INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER LOW LEVEL
JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS TONIGHT.
FOR THIS EVENING 5 THSD TO 10 THSD SCT IS EXPECTED...WITH SCT
CLOUDS INCREASING AT OR ABOVE 25 THSD FT. ISOLATED SHRA AND TSRA
ARE POSSIBLE VCNTY OF KDRT THRU 04Z. LATER TONIGHT...CIGS WILL
FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT AROUND OR AFTER
04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z TONIGHT. CIGS OF 500 TO
900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO KSAT FROM 07Z TO 16Z
MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD BKN TO OVC AFTER 16Z
MONDAY...AND THEN INCREASE TO CIGS 3 THSD TO 5 THSD BKN AFTER 19Z
MONDAY AFTERNOON. SOUTH AND SOUTHEAST WINDS NEAR 10 KNOTS WILL
PICKUP TO 15 TO 20 KNOTS MONDAY...IN ADVANCE OF A STORM
SYSTEM...THAT WILL BRING INCREASING CHANCES OF SHOWERS OR
THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON MONDAY NIGHT
THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO MOVE TO THE
TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN MOVE EAST LATE
TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...NORTH OF SOUTH
CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...SCATTERED WRAP AROUND
CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS TAF SITES...AS MORE
PREVAILING WEST TO NORTHWEST SFC WINDS DEVELOP...IN A PATTERN
SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 622 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE AVIATION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS THE SFC LOW PRESSURE CONTINUES
TO INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER
LOW LEVEL JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS.
CIGS WILL FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT
AROUND OR AFTER 04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z
TONIGHT. CIGS OF 500 TO 900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO
KSAT FROM 07Z TO 16Z MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD
BKN TO OVC AFTER 16Z MONDAY...AND THEN INCREASE TO CIGS 3 THSD
TO 5 THSD BKN AFTER 19Z MONDAY AFTERNOON. SOUTH AND SOUTHEAST
WINDS NEAR 10 KNOTS WILL PICKUP TO 15 TO 20 KNOTS MONDAY...IN
ADVANCE OF A STORM SYSTEM...THAT WILL BRING INCREASING CHANCES OF
SHOWERS OR THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON
MONDAY NIGHT THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO
MOVE TO THE TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN
MOVE EAST LATE TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...
NORTH OF SOUTH CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...
SCATTERED WRAP AROUND CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS
TAF SITES...AS MORE PREVAILING WEST TO NORTHWEST SFC WINDS
DEVELOP...IN A PATTERN SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 339 PM CDT SUN APR 1 2012/
DISCUSSION...
WEAK PAIR OF SHORTWAVES WILL MAKE FOR A SLIGHT CHANCE OF
THUNDERSTORMS TONIGHT INTO MONDAY...BUT LIMITED SURFACE FOCUS WILL
MAKE IT DIFFICULT TO HIGHLIGHT AREAS OF CONVECTION INITIATION. ONE
LIKELY AREA OVER THE BURRO MOUNTAINS HAS ALREADY YIELDED
CONVECTION...BUT MODEL FORECAST WINDS SHOW STORM MOTIONS THAT WILL
TAKE A LONG TIME TO REACH THE RIO GRANDE. ISOLATED POPS ARE POSTED
ALONG THE RIO GRANDE WITH A FEW SHOWERS FORMING BENEATH THE CAP
POSSIBLE OVER EASTERN COUNTIES LATE TONIGHT. DEEPENING LOW LEVEL
MOISTURE SHOULD PROMOTE HIGHER RAIN AND THUNDERSTORM POTENTIAL
DURING THE DAY MONDAY AS A LARGE UPPER LOW DRAWS CLOSER.
THE APPROACHING LOW PRESSURE FROM THE WEST WILL BRING A SEVERE
WEATHER POTENTIAL...BUT SOME UNCERTAINTIES ON TIMING AND LOCATION
DUE TO MODELS SHOWING A SLOWING AND WOBBLING TREND. RECENT MODEL
TRENDS SHOW A SLIGHTLY MORE NORTHWARD TRACK WHEN THE LOW FINALLY
CROSSES TX LATE TUESDAY INTO WEDNESDAY. THIS GIVES SOUTH CENTRAL
TEXAS BOTH THE POTENTIAL FOR A SEVERE WEATHER EVENT MONDAY NIGHT
INTO TUESDAY AND ALSO A POTENTIAL TO BE DRY-SLOTTED...OF WHICH
EITHER SCENARIO COULD BE ENHANCED BY A SUBTLE WOBBLE. WILL STICK
WITH GENERIC SEVERE THREATS FOR NOW WITH BEST CHANCE OVER THE NW
HALF LATE MONDAY NIGHT/EARLY TUESDAY MORNING. IF THE DRY SLOT DOES
NOT SCRAPE AWAY TOO MUCH MOISTURE...A SEVERE AND POTENTIAL HEAVY
RAIN EVENT COULD DEVELOP DURING THE DAY TUESDAY BEFORE THE PACIFIC
FRONT PUSHES THROUGH THE I-35 CORRIDOR LATE IN THE DAY.
BASED ON A SPLIT OF MODEL SOLUTIONS WILL ADD A BIT MORE COLD AND
DRY AIR THAN IS SUGGESTED BY THE GFS SOLUTION WHICH MINIMIZES THE
COLD FRONT AND RETURNS MOISTURE QUICKLY BY THURSDAY. WILL PUSH THE
MOISTURE RETURN BACK TO FRIDAY TO ENABLE MORE SEASONAL TEMPS
THURSDAY AND FRIDAY. WILL ALSO LIMIT POPS FOR THE NEXT WEATHER
SYSTEM TO IMPACT THE AREA SATURDAY AND NEXT SUNDAY DUE TO THE MORE
GRADUAL MOISTURE RETURN AND THE PRESENCE OF AN UPPER RIDGE OVER
TX.
FIRE WEATHER...
A GOOD CHANCE OF WETTING RAINS COMBINED WITH NEAR OF ABOVE NORMAL
RAINFALL OVER WESTERN COUNTIES THE PAST 30 DAYS SHOULD LIMIT FIRE
SPREAD POTENTIAL...AS MOST AREAS HAVE NOTED A GOOD GREEN-UP OVER
SOUTH CENTRAL TEXAS. THUS WILL ANTICIPATE ONLY AN ELEVATED FIRE
WEATHER DAY DESPITE STRONG WEST WINDS AND CRITICAL RH VALUES NEAR
THE RIO GRANDE ON TUESDAY. WILL NEED TO LOOK AT THIS AREA IN MORE
DETAIL IN LATER PACKAGES IF FUTURE MODEL RUNS DECREASE THE RAIN
POTENTIAL FOR THE WESTERN COUNTIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 84 67 77 60 / 10 20 40 50 20
AUSTIN BERGSTROM INTL AIRPORT 68 84 66 78 60 / 10 20 40 50 20
NEW BRAUNFELS MUNI AIRPORT 66 84 67 80 59 / 10 20 40 50 20
BURNET MUNI AIRPORT 66 83 65 77 57 / 10 20 40 50 20
DEL RIO INTL AIRPORT 67 93 64 86 58 / 10 20 40 20 -
GEORGETOWN MUNI AIRPORT 66 81 65 76 58 / 10 20 40 50 20
HONDO MUNI AIRPORT 67 86 66 79 56 / 40 20 40 40 10
SAN MARCOS MUNI AIRPORT 67 84 67 79 60 / 10 20 40 50 20
LA GRANGE - FAYETTE REGIONAL 69 83 70 80 65 / 10 20 40 50 30
SAN ANTONIO INTL AIRPORT 69 84 68 79 58 / 10 20 40 40 10
STINSON MUNI AIRPORT 68 85 68 80 60 / 10 20 40 40 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 PM CDT MON APR 2 2012
.SHORT TERM...THROUGH WEDNESDAY NIGHT
249 PM CDT MON APR 2 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT INTO
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SOUTH DAKOTA. A WARM FRONT EXTENDED SOUTHEAST FROM THE
LOW ACROSS IOWA INTO CENTRAL ILLINOIS.
WATER VAPOR SATELLITE SHOWS UPPER LEVEL RIDGING REMAINS OVER THE
UPPER MIDWEST TODAY. THE CONCERN FOR TONIGHT IS WHAT IS GOING TO
HAPPEN TO THIS RIDGE. THE CONSENSUS OF THE 02.12Z MODELS IS THAT
IT IS PRETTY MUCH GOING TO STAY IN PLACE AS IT IS BLOCKED FROM
MOVING EAST BY A LONG WAVE TROUGH JUST OFF THE EAST COAST.
HOWEVER...THE NORTHERN EXTENT OF THE RIDGE SHOULD GET FLATTENED
SOME AS THE NORTHERN STREAM SYSTEM OVER SOUTHERN CANADA CONTINUES
TO MOVE EAST PRODUCING SOME HEIGHT FALLS OVER NORTHERN MINNESOTA
AND WISCONSIN. THE 02.00Z ECMWF HAS BEEN THE MOST CONSISTENT WITH
THE HANDLING OF THIS SYSTEM AND THE 02.12Z NAM NOW HAS COME INTO
GOOD AGREEMENT WITH THE ECMWF. AS THE SHORT WAVE TROUGH MOVES BY
LATE TONIGHT...IT WILL PRODUCE THOSE MINOR HEIGHT FALLS WITH
POSSIBLY UP TO 2 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB
LAYER ACROSS NORTHERN WISCONSIN. THE SURFACE LOW IS EXPECTED TO
EITHER TRACK ACROSS SOUTHERN MINNESOTA OR NORTHERN IOWA AS IT
MOVES TOWARD NORTHERN ILLINOIS BY TUESDAY MORNING. THIS SHOULD
ALLOW THE WARM FRONT TO GET LIFTED INTO THE SOUTHERN PORTIONS OF
THE FORECAST AREA WITH WEAK TO MODERATE FRONTOGENESIS OCCURRING
NORTH OF THE FRONT LATE TONIGHT. THE WARM AIR ADVECTION OVER THE
WARM FRONT WILL PRODUCE PERSISTENT UP GLIDE OF 1 TO 4 UBAR/S ON
THE 305K ISENTROPIC SURFACE. A LOT OF THIS UP GLIDE WILL INITIALLY
GO INTO SATURATION AND BY THE TIME SATURATION OCCURS THE BEST UP
GLIDE WILL BE MOVING OFF TO THE EAST OF THE AREA.
THE WILD CARD IN WHERE THE CONVECTION WILL DEVELOP TONIGHT IS THE
WARM FRONT. THE 02.12Z GFS HAS BEEN CONSISTENTLY FARTHER SOUTH
WITH THE NOSE OF THE MOISTURE TRANSPORT AND LOW LEVEL JET INTO THE
FRONT AROUND THE I90 CORRIDOR. THE NAM AND ECMWF INDICATE THE LOW
LEVEL JET AND MOISTURE TRANSPORT WILL CONTINUE PAST THE FRONT AND
CONTINUE FARTHER NORTH CLOSER TO THE SHORT WAVE TROUGH. THIS
SCENARIO HAS MOST OF THE CONVECTION DEVELOPING ACROSS THE NORTHERN
PARTS OF THE AREA INTO NORTHERN WISCONSIN AND THEN TRANSLATING
INTO NORTHEAST AND EASTERN WISCONSIN AS THE LOW LEVEL JET BENDS
OVER TO THE EAST. THE NAM SUGGESTS THERE COULD BE AROUND 750 J/KG
OF ELEVATED CAPE ABOVE 2KM FOR THE STORMS TO WORK WITH. THE 0-3KM
SHEAR SHOULD BE AROUND 30 TO 35 KNOTS BUT TAKING OUT THE LOWEST
1KM OF THIS SINCE THE STORMS WILL BE ELEVATED BRINGS THIS DOWN TO
15 TO 20 KNOTS. THIS IS NOT EXPECTED TO BE ENOUGH SHEAR TO ALLOW
THE STORMS THAT FORM TO PRODUCE ANY SEVERE WEATHER BUT WITH
PRECIPITABLE WATERS EXPECTED TO BE 200-250 PERCENT OF NORMAL...CAN
NOT RULE OUT SOME LOCALIZED HEAVY RAINS.
THE 02.12Z HIRES ARW AND NMM ALONG WITH THE 02.16Z HRRR ARE IN
VERY GOOD AGREEMENT WITH THE NAM AND ECMWF INITIATING THE
CONVECTION THIS EVENING FARTHER TO THE NORTH AS THE MOISTURE
TRANSPORT OVERRUNS THE WARM FRONT. HAVE THUS MAINTAINED THE IDEA
THAT THE BEST CHANCES FOR CONVECTION WILL BE ACROSS THE NORTHERN
PARTS OF THE AREA AND AFTER MIDNIGHT AS THE WEAK FORCING FROM THE
SHORT WAVE TROUGH APPROACHES. WILL KEEP A SMALL CHANCE OF RAIN IN
THE FORECAST FOR THIS EVENING AS THE WARM FRONT APPROACHES ACROSS
MOST OF THE AREA. MAINTAINED THE 30 TO 50 PERCENT CHANCES FOR
AFTER MIDNIGHT TAPERING BACK TO JUST A 20 PERCENT CHANCE ACROSS
THE EAST TUESDAY MORNING FOR ANY LINGERING SHOWERS. THE FRONT
SHOULD BE FAR ENOUGH SOUTH TO HAVE A DRY TUESDAY AFTERNOON. AFTER
THAT...HIGH PRESSURE WILL BUILD IN TO BRING SOME COOLER
TEMPERATURES AND DRIER AIR. DID NOT ADD ANY FROST TO THE FORECAST
FOR TUESDAY NIGHT OR WEDNESDAY NIGHT AS TEMPERATURES AND DEW POINTS
ARE EXPECTED TO MAINTAIN A 5 TO 10 DEGREE SPREAD. THERE SHOULD
ALSO BE SOME WINDS BOTH NIGHT TO CREATE SOME MIXING AND THE
COMBINATION OF THE WINDS AND DRIER AIR SHOULD PRECLUDE FROST
FORMATION. PORTIONS OF CENTRAL WISCONSIN NORTH OF THE I94 CORRIDOR
COULD POSSIBLY SEE SOME FREEZING TEMPERATURES BOTH OF THESE NIGHTS.
.LONG TERM...THURSDAY THROUGH MONDAY
249 PM CDT MON APR 2 2012
THE HIGH WILL REMAIN OVER THE REGION THROUGH FRIDAY MAINTAINING THE
POSSIBILITY OF SOME FROST AND FREEZING TEMPERATURES AT NIGHT FOR
THE END OF THE WEEK. THE HIGH WILL THEN MOVE OFF FOR THE WEEKEND
AS THE NEXT SYSTEM COMES INTO THE AREA. SOME TIMING DIFFERENCES
BETWEEN THE 02.12Z GFS...ECMWF AND GEM WITH THE COLD FRONT COMING
ACROSS. THE ECMWF AND GEM ARE A LITTLE FASTER BUT ALL SHOW AT
LEAST A CHANCE FOR SOME RAIN SATURDAY INTO SATURDAY NIGHT BEFORE
IT MOVES OFF TO THE EAST FOR SUNDAY. SOME DIFFERENCES FOR NEXT
MONDAY WITH THE ECMWF DROPPING ANOTHER SHORT WAVE TROUGH OVER THE
AREA FOR THE POSSIBILITY OF SOME SHOWERS WHILE THE GFS IS DRY WITH
HIGH PRESSURE BUILDING IN. WILL HONOR THE ECMWF WITH A SMALL RAIN
CHANCE FOR MONDAY.
&&
.AVIATION...THROUGH 18Z TUESDAY
1233 AM CDT MON APR 2 2012
MAIN FORECAST CHALLENGE IS ON CEILING HEIGHTS THROUGH THE TAF
PERIOD AND CONVECTIVE POTENTIAL TONIGHT. A NARROW BAND OF VFR
CLOUDS WAS PUSHING THROUGH THE KLSE TAF SITE AND SHOULD PUSH OUT
BY EARLY AFTERNOON. VFR CONDITIONS THEN EXPECTED THROUGH MUCH OF
THE NIGHT TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE INTO NORTHERN
IOWA TONIGHT. MOISTURE TRANSPORT FOCUSES INTO NORTHERN MINNESOTA
THIS EVENING AND THEN NORTHERN WISCONSIN OVERNIGHT AHEAD OF THE
LOW. EXPECT CONVECTION TO DEVELOP IN THESE AREAS...BUT AT THIS
POINT LOOKS LIKE IT SHOULD REMAIN NORTH OF THE TAF SITES. DID ADD
MENTION OF VCSH FROM 10Z-15Z DUE TO THE UNCERTAINTY. SURFACE
BOUNDARY LOOKS TO MOVE THROUGH THE TAF SITES 11-12Z ACCOMPANIED
BY LOWER MVFR CEILINGS...WHICH WILL PERSIST THROUGH 18Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 PM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1233 PM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...THROUGH 18Z TUESDAY
1233 AM CDT MON APR 2 2012
MAIN FORECAST CHALLENGE IS ON CEILING HEIGHTS THROUGH THE TAF
PERIOD AND CONVECTIVE POTENTIAL TONIGHT. A NARROW BAND OF VFR
CLOUDS WAS PUSHING THROUGH THE KLSE TAF SITE AND SHOULD PUSH OUT
BY EARLY AFTERNOON. VFR CONDITIONS THEN EXPECTED THROUGH MUCH OF
THE NIGHT TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE INTO NORTHERN
IOWA TONIGHT. MOISTURE TRANSPORT FOCUSES INTO NORTHERN MINNESOTA
THIS EVENING AND THEN NORTHERN WISCONSIN OVERNIGHT AHEAD OF THE
LOW. EXPECT CONVECTION TO DEVELOP IN THESE AREAS...BUT AT THIS
POINT LOOKS LIKE IT SHOULD REMAIN NORTH OF THE TAF SITES. DID ADD
MENTION OF VCSH FROM 10Z-15Z DUE TO THE UNCERTAINTY. SURFACE
BOUNDARY LOOKS TO MOVE THROUGH THE TAF SITES 11-12Z ACCOMPANIED
BY LOWER MVFR CEILINGS...WHICH WILL PERSIST THROUGH 18Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
642 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...TODAY AND TONIGHT
641 AM CDT MON APR 2 2012
MVFR CONDITIONS CAN BE EXPECTED AT KRST EARLY THIS MORNING AS A
STRATUS DECK JUST BRUSHES THE TAF SITE PRODUCING CEILINGS AROUND 2
KFT. CONDITIONS SHOULD QUICKLY IMPROVE TO VFR BY MID MORNING. VFR
CONDITIONS ARE EXPECTED AT KLSE THROUGH THE AFTERNOON HOURS. A MID
LEVEL CLOUD DECK WILL PRODUCE CEILINGS AROUND 6 KFT AT KLSE
THROUGH 14Z...THEN SCATTERED OUT DURING THE MID TO LATE MORNING
HOURS. SOUTHEAST WINDS OF 13 TO 20 KTS WILL PERSIST THROUGH THE
DAY TODAY. WIND GUSTS UP TO 30 KTS ARE POSSIBLE ESPECIALLY AT
KRST. A WARM FRONT CURRENTLY POSITIONED ACROSS CENTRAL IOWA...WILL
LIFT NORTHWARD INTO NORTHERN IOWA/SOUTHERN WISCONSIN AS SURFACE
LOW PRESSURE MOVES INTO NORTHEAST IOWA THIS AFTERNOON. LOW LEVEL
MOISTURE WILL BE PUMPED NORTHWARD INTO THE REGION THIS EVENING
INTO THE OVERNIGHT HOURS...LEADING TO THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS. PLAN ON CEILINGS LOWERING INTO THE 3 TO 4 KFT
RANGE THIS EVENING AS THE WARM FRONT MOVES IN. FORECAST MODELS
SHOWING SOME DIFFERENCES ON EXACTLY WHERE THE SHOWERS AND
THUNDERSTORMS WILL DEVELOP. THERE ARE SIGNALS THAT THE ACTIVITY
COULD DEVELOP ALONG THE INTERSTATE 90 CORRIDOR...WHILE THERE ARE
OTHERS THAT SUGGEST THE THUNDERSTORMS COULD DEVELOP ACROSS
NORTHERN WISCONSIN. GIVEN THE UNCERTAINTY ON TIMING AND LOCATION
OF THE THUNDERSTORMS DECIDED TO INCLUDE CB MENTION IN THE
TAF...STARTING AT 08Z AT KRST AND 10Z AT KRST...WITH A FORECAST
MODEL CONSENSUS OF THE THUNDERSTORMS FIRING AFTER 06Z. CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH 12 Z...BEFORE A
COLD FRONT MOVES THROUGH WITH WINDS SHIFTING TO THE NORTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CDT SUN APR 1 2012
WARM FRONT CURRENTLY RESIDES ACROSS IOWA...WITH BROAD EASTERLY
FLOW TO ITS NORTH OVER THE TAF SITES. SMALL BAND OF STRATUS WAS
SEEN FROM EASTERN IOWA INTO NORTH CENTRAL IOWA...JUST NORTH OF THE
WARM FRONT. 02.02Z RUC 925MB RELATIVE HUMIDITY FIELD DEPICTS THE
LOCATION ACCURATELY...BUT IS OVERDONE WITH THE SPATIAL COVERAGE.
TRENDS IN BOTH THE NAM AND RUC SHOW THIS MOISTURE TO CONTINUE TO
ADVECT NORTHWEST INTO SOUTHERN MINNESOTA THROUGH 12Z. IT LOOKS AS
THOUGH THIS WILL JUST MISS THE KRST TAF SITE...BUT DID CONTINUE TO
INCLUDE SOME SCATTERED STRATUS BETWEEN 08Z-16Z. EASTERLY FLOW WILL
CONTINUE THROUGHOUT THE REMAINDER OF THE PERIOD WITH THE PRESSURE
GRADIENT TIGHTENING MONDAY MORNING. COULD SEE SOME GUSTS TO 20 TO
25 KNOTS AT KRST BETWEEN 16Z-22Z...WITH SLIGHTLY LOWER GUSTS AT
KLSE. ALSO EXPECT VFR CEILINGS TO FORM WITH A BKN040-050KFT DECK
EXPECTED FROM 16Z ON. SURFACE LOW MOVES INTO IOWA BETWEEN 00Z-06Z
MONDAY. ANY CONVECTION THAT FIRES IS EXPECTED TO BE NORTH AND WEST
OF THE TAF SITES THROUGH 06Z THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT SUN APR 1 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
303 PM CDT SUN APR 1 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES MONDAY THROUGH
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER
WESTERN NORTH AND SOUTH DAKOTA. A WARM FRONT EXTENDS SOUTHEAST
FROM THE LOW INTO CENTRAL ILLINOIS.
WATER VAPOR SATELLITE SHOWS UPPER LEVEL RIDGING OVER THE UPPER
MIDWEST TODAY AS THE NEXT STORM SYSTEM IS WORKING ACROSS THE ROCKY
MOUNTAINS. MODELS CONTINUE TO BE CONSISTENT IS SHOWING THE ENERGY
IN THE TROUGH SPLITTING INTO A PROGRESSIVE NORTHERN STREAM SYSTEM
AND A CUT OFF SOUTHERN STREAM UPPER LEVEL LOW. THE SPLIT OF THE
ENERGY HAS ALREADY STARTED AND WILL CONTINUE THROUGH THE NIGHT.
THE MODELS ALSO HAVE CONTINUED THEIR TREND OF BEING SLOWER PUSHING
THE UPPER LEVEL RIDGE OUT OF THE AREA AND NOW SUGGEST THIS MAY NOT
OCCUR UNTIL MONDAY NIGHT. THERE ALSO IS THE SUGGESTION THAT THE
NORTHERN STREAM SHORT WAVE TROUGH MAY BE A LITTLE BIT STRONGER
THAN PREVIOUSLY INDICATED BUT THE BULK OF THE FORCING FROM THIS
WAVE WILL STILL PASS BY TO THE NORTH. THE 01.12Z GFS ONLY SUGGEST
AROUND 4 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER
COULD POSSIBLY MOVE ACROSS NORTHERN WISCONSIN TUESDAY.
AS THE WHOLE SYSTEM ADVANCES EAST...THE SURFACE LOW IS EXPECTED TO
REFORM OVER NEBRASKA AND THEN MOVE EAST/NORTHEAST ALONG A COLD
FRONT. AS THE FRONT COMES THROUGH...WEAK FRONTOGENESIS SHOULD
OCCUR ACROSS MINNESOTA AND WISCONSIN CLOSER TO THE UPPER LEVEL
SUPPORT. A BROAD AREA OF WARM AIR ADVECTION WILL OCCUR AHEAD OF
THE COLD FRONT WHICH RESULTS IN 1 TO 3 UBARS/S OF UP GLIDE ON THE
305K ISENTROPIC SURFACE FOR MONDAY AND MONDAY NIGHT. WITH THE
SLOWER ARRIVAL OF THE FORCING...REMOVED THE RAIN CHANCES FOR
MONDAY MORNING AND LIMITED THEM TO THE FAR NORTHWEST SECTIONS OF
THE FORECAST AREA MONDAY AFTERNOON. THE BETTER FORCING THEN
ARRIVES MONDAY NIGHT AHEAD OF THE SHORT WAVE TROUGH WITH THE BEST
CHANCES FOR RAIN ACROSS THE NORTH CLOSER TO WHERE THE PV ADVECTION
WILL BE. NO CHANGES MADE TO THE MONDAY NIGHT FORECAST WITH UP TO A
50 PERCENT CHANCE ACROSS THE NORTH. ADDED IN SOME 20 TO 30 PERCENT
RAIN CHANCES FOR TUESDAY MORNING ACROSS THE SOUTHEAST TO ACCOUNT
FOR THE SLOWER MOVEMENT OF THE SYSTEM AND THE POSSIBILITY OF SOME
LINGERING SHOWERS. REMAIN CONCERNED THAT THE FORECAST REMAINS TOO
FAST BRINGING THIS SYSTEM INTO THE AREA AS THE ECMWF HAS
CONSISTENTLY BEEN SLOWER THAN EITHER THE NAM OR GFS. THE 31.00Z
AND 04.12Z RUNS OF ECMWF CONTINUE THIS TREND AND IF THIS SLOWER
SOLUTION VERIFIES...WOULD NOT BE SURPRISED TO SEE THE ENTIRE AREA
REMAINS DRY MONDAY WITH WARMER TEMPERATURES AS THE WARM AIR OVER
IOWA...NEBRASKA AND MISSOURI GETS DRAWN INTO THE REGION AHEAD OF
THE COLD FRONT. THIS COULD ALSO LEAD TO NEEDING RAIN CHANCES
FARTHER WEST TUESDAY MORNING POSSIBLY LINGERING INTO THE AFTERNOON
ACROSS THE SOUTHEAST.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
303 PM CDT SUN APR 1 2012
ONCE THE EARLY WEEK SYSTEM MOVES THROUGH...HIGH PRESSURE IS
EXPECTED TO SETTLE IN OVER THE REGION FOR THE REMAINDER OF THE
WORK WEEK. THIS HIGH WILL BRING THE POTENTIAL FOR CENTRAL
WISCONSIN TO POSSIBLY DIP INTO THE LOWER TO MIDDLE 30S SETTING UP
THE POTENTIAL FOR SOME FREEZING CONDITIONS OR FROST FORMATION.
ONCE THE HIGH MOVES OFF...THE NEXT SYSTEM WILL APPROACH FOR THE
WEEKEND. THERE CONTINUES TO BE A TREND OF SLOWING THIS SYSTEM DOWN
AND MOST OF THE AREA SHOULD REMAIN DRY FRIDAY NIGHT BEFORE THE
COLD FRONT MOVES IN WITH SOME RAIN CHANCES FOR SATURDAY AND
SATURDAY NIGHT.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CDT SUN APR 1 2012
WARM FRONT CURRENTLY RESIDES ACROSS IOWA...WITH BROAD EASTERLY
FLOW TO ITS NORTH OVER THE TAF SITES. SMALL BAND OF STRATUS WAS
SEEN FROM EASTERN IOWA INTO NORTH CENTRAL IOWA...JUST NORTH OF THE
WARM FRONT. 02.02Z RUC 925MB RELATIVE HUMIDITY FIELD DEPICTS THE
LOCATION ACCURATELY...BUT IS OVERDONE WITH THE SPATIAL COVERAGE.
TRENDS IN BOTH THE NAM AND RUC SHOW THIS MOISTURE TO CONTINUE TO
ADVECT NORTHWEST INTO SOUTHERN MINNESOTA THROUGH 12Z. IT LOOKS AS
THOUGH THIS WILL JUST MISS THE KRST TAF SITE...BUT DID CONTINUE TO
INCLUDE SOME SCATTERED STRATUS BETWEEN 08Z-16Z. EASTERLY FLOW WILL
CONTINUE THROUGHOUT THE REMAINDER OF THE PERIOD WITH THE PRESSURE
GRADIENT TIGHTENING MONDAY MORNING. COULD SEE SOME GUSTS TO 20 TO
25 KNOTS AT KRST BETWEEN 16Z-22Z...WITH SLIGHTLY LOWER GUSTS AT
KLSE. ALSO EXPECT VFR CEILINGS TO FORM WITH A BKN040-050KFT DECK
EXPECTED FROM 16Z ON. SURFACE LOW MOVES INTO IOWA BETWEEN 00Z-06Z
MONDAY. ANY CONVECTION THAT FIRES IS EXPECTED TO BE NORTH AND WEST
OF THE TAF SITES THROUGH 06Z THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT SUN APR 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS MIAMI FL
448 AM EDT WED APR 4 2012
...FEW STRONG THUNDERSTORMS POSSIBLE THIS AFTERNOON, THU AFTERNOON, AND
FRIDAY WITH LOW PROBABILITIES OF SEVERE...
...HOT THROUGH FRIDAY, THEN COOLER AND DRIER THIS WEEKEND-NEXT WEEK...
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A MID/UPPER LEVEL LOW
SPINNING OVER THE TEXAS/OKLAHOMA PANHANDLE REGION WITH WEST
SOUTHWEST FLOW PREDOMINATING ACROSS THE GULF AND ACROSS FLORIDA.
BOTH GFS AND ECMWF SHOW THIS UPPER LOW MOVING ACROSS THIS MID
SOUTH ON THU...THEN OPENING UP AND MERGING WITH A TROUGH WHICH
WILL AMPLIFY ACROSS NEW ENGLAND AND THE MID ATLANTIC STATES ON
FRIDAY. LOW PRESSURE WILL DEVELOP NEAR THE CAROLINA COAST MOVING
INTO THE ATLANTIC FRIDAY WITH A TRAILING COLD FRONT SWEEPING
ACROSS SOUTH FLORIDA FRIDAY EVENING.
AHEAD OF THIS FRONT, THE AIRMASS WILL CONTINUE FAIRLY DRY WITH
FORECAST SOUNDINGS SHOWING PWAT VALUES OF 1-1.2 INCHES TODAY
RISING TO 1.3-1.5 LATE THU-FRI. IT WILL BE UNSTABLE EACH AFTERNOON
THROUGH FRIDAY. GOES SOUNDER DATA SHOWS H5 TEMPS NOW IN THE -12 TO
-13C RANGE OVER SOUTH FLORIDA. FCST SOUNDINGS SHOW EVEN SLIGHT
COOLING TO -14C BY EVENING WITH LI`S FALLING TO AROUND -7C AND
CAPE NEARING 2000 J/KG LATE IN THE DAY. GIVEN LACK OF
MOISTURE...ONLY HAVE SLIGHT CHC POPS INTERIOR-EAST. IT`S POSSIBLE
THAT NOTHING DEVELOPS THIS AFTERNOON...BUT THERE MAY BE JUST
ENOUGH MOISTURE TO ALLOW A FEW TSTORMS TO DEVELOP. HRRR INDEED
DOES SHOW ISOLATED DEVELOPMENT INTERIOR/EAST COAST THIS AFTERNOON.
GIVEN THE STRONG HEATING TODAY AND COLD AIR ALOFT, ONE OR TWO PULSE
STRONG TSTORMS WILL BE POSSIBLE INTERIOR-EAST, CAPABLE OF
PRODUCING GUSTY WINDS UP TO 50 MPH ALONG WITH HAIL AND FREQUENT
LIGHTNING STRIKES.
AS MOISTURE INCREASES A TAD THURSDAY AFTERNOON, THE RISK OF TSTORMS
INCREASES. SW STEERING FLOW WILL LEAD TO CONVERGENCE ACROSS THE
EAST COAST METRO AREAS, SO SCATTERED TSTORMS ARE EXPECTED EAST
COAST METRO WITH A SLIGHT CHANCE ELSEWHERE. THEN ON FRIDAY THERE
WILL BE A CHANCE OF THUNDERSTORMS AREA WIDE ALONG/AHEAD OF THE
COLD FRONT. STABILITY INDICES SHOW THAT IT WILL CONTINUE TO BE
QUIET UNSTABLE, PARTICULARLY ON THURSDAY AFTERNOON. HOWEVER, THE
BETTER DYNAMICS WILL BE ON FRIDAY. STRONG TSTORMS WILL BE POSSIBLE
EACH DAY WITH LOW PROBABILITIES OF SEVERE. CURRENT ASSESSMENT
SUGGESTS THAT THE GREATEST POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS
IS THURSDAY AFTERNOON EAST COAST METRO...DUE TO WEAKER FLOW ON THIS
DAY, BETTER SURFACE CONVERGENCE AND HIGH INSTABILITY.
HOT DAYS WILL PREVAIL THROUGH FRIDAY WITH HIGHS TOPPING 90 MOST
INLAND LOCALES AND NEAR 90 EAST. CONSENSUS GUIDANCE WAS TOO COOL
FOR MAXES NEXT FEW DAYS...SO FOLLOWED A NAM12-GFS BLEND. THE COLD
FRONT WILL MOVE ACROSS SOUTH FL FRIDAY EVENING, BRINGING IN A COOL
AIRMASS FOR APRIL STANDARDS WITH HIGHS IN THE UPPER 70S TO LOWER
80S AND DEWPOINTS FALLING INTO THE 50S THIS WEEKEND. NIGHTTIME
LOWS WILL FALL INTO THE 50S INTERIOR AND 60S COASTS. THIS COOLER
TREND WILL CONTINUE NEXT WEEK...WITH BOTH GFS/ECMWF SHOWING A RE-
ENFORCING SHOT OF COOLER AIR FROM THE NORTH MID WEEK. THIS WILL
KEEP TEMPS/HUMIDITY IN CHECK THROUGH NEXT WEEK WITH COMFORTABLE
WEATHER PREVAILING AND DRY WEATHER EXPECTED.
&&
.MARINE...NO CONCERNS IN THE NEAR TERM, BUT WINDS/SEAS WILL
INCREASE, ESPECIALLY IN THE GULF STREAM BEHIND THE COLD FRONT FRI
EVENING AS WINDS BECOME NE AND INCREASE.
&&
.FIRE WEATHER...RELATIVE HUMIDITIES FELL INTO THE MID 20S TO LOWER
30S OVER A LARGE PORTION OF INTERIOR SOUTH FL YESTERDAY. TODAY,
LOW RH`S OF BELOW 35 PERCENT FOR 4 HR OR MORE ARE FORECAST FOR THE
LAKE OKEECHOBEE REGION AND INLAND COLLIER AND INLAND BROWARD
COUNTIES...SO WILL BE ISSUING A FIRE DANGER STMT FOR THESE
LOCALES. MOISTURE WILL INCREASE ON THU-FRI WITH MODIFYING RH`S
THEN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 89 72 / 20 10 40 40
FORT LAUDERDALE 88 72 89 73 / 10 10 30 30
MIAMI 88 72 89 73 / 10 10 30 30
NAPLES 85 69 85 71 / - 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
340 AM EDT WED APR 4 2012
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 4 2012
07Z SFC ANALYSIS SHOWS A LOW CENTERED OVER SOUTHERN MISSOURI WITH A
WEST TO EAST WARM FRONT/ELONGATED AREA OF LOWER PRESSURE RUNNING
GENERALLY ALONG THE OHIO RIVER. THIS BOUNDARY HAS REMAINED
INTERMITTENTLY ACTIVE THROUGH THE NIGHT...EVEN AS THE MORE ROBUST...
DIURNALLY DRIVEN...SLOW MOVING CONVECTION DIED OUT OVER EAST
KENTUCKY DURING THE LATE EVENING. DO EXPECT THAT THIS REGION OF LOWER
PRESSURE WILL BECOME MORE ACTIVE TOWARD DAWN IN CONJUNCTION WITH A
SLOW MOVING BAND OF MID LEVEL SHORTWAVES RUNNING THROUGH THE
SOUTHERN OHIO VALLEY. THE ENVIRONMENT IS RELATIVELY MOIST OVER THE
AREA WITH DEWPOINTS RUNNING IN THE MID AND UPPER 50S WHILE
TEMPERATURES ARE SETTLING INTO THE LOWER 60S IN MOST PLACES...EARLY
THIS MORNING.
THE MODELS ARE IN DECENT AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL ROLL A CLOSED AND SOMEWHAT CUT OFF
LOW THROUGH THE SOUTHERN PLAINS AND TOWARDS THE LOWER OHIO VALLEY BY
THURSDAY MORNING. FLAT RIDGING AND DEEP SOUTHWEST FLOW EXIST OUT
AHEAD OF THIS LOW AFFECTING KENTUCKY AND THIS WILL BE SQUEEZED OFF
TO THE EAST BY 12Z THURSDAY. AT THE SAME TIME...A DEEP TROUGH OVER
THE NORTHEAST WILL SHIFT SLIGHTLY SOUTH. GIVEN THE MODEL SIMILARITIES
ALOFT HAVE GONE WITH A BLENDED SOLUTION WITH A LEAN TOWARD THE
HIGHER RESOLUTION NAM12...AND A NOD TO THE HRRR IN THE NEAR TERM...
BUT TRANSLATED SLIGHTLY SOUTH IN LINE WITH THE OTHER MODELS LATTER IN
THE SHORT TERM.
AN ACTIVE WEATHER PERIOD IS UPON US WITH THE APPROACH OF THE UPPER
LOW TO THE WEST AND THE STALLED BOUNDARY LAYING OVER NORTRHERN PARTS
OF EAST KENTUCKY. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
AND INCREASE THROUGH THE AREA LATER TODAY AS DIURNAL HEATING
INITIATES CONVECTION...HELPED ALONG BY SFC CONVERGENCE WITH THE
BOUNDARY AND SOME UPPER LEVEL DIVERGENCE. THE STEAMY BOUNDARY LAYER
WILL CONTRIBUTE TO HIGH INSTABILITY TODAY WITH MID LEVEL WINDS
FAVORABLE FOR MORE ORGANIZED CONVECTION. AS A RESULT...STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH THE AREA WITH HIGH PW
AIR SETTING THE STAGE FOR HEAVY RAIN FROM ANY HEALTHY STORMS.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREAT FROM THESE. THE
STORMS WILL BE MORE PROGRESSIVE THAN YESTERDAY...BUT TRAINING...AND
PLENTY OF AREAS OF LOWER FFG AFTER YESTERDAY/S RAINS...WILL MAKE
FLASH FLOODING A CONCERN LATER TODAY AND THROUGH THE FIRST PART OF
THE NIGHT. ACCORDINGLY...WILL HOIST A FLASH FLOOD WATCH FOR ALL BUT
OUR NORTHWEST COUNTIES. THE HEAVIER RAINS WILL DISSIPATE BY THURSDAY
MORNING AS DRIER AIR SEEPS INTO THE REGION FROM THE NORTH...BUT THE
THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE
DAY. THE BAROCLINIC ZONE IN PLACE THROUGH THE AREA ON THURSDAY WILL
KEEP THE NORTHERN COUNTIES UP TO 10 DEGREES COOLER THAN THE SOUTHERN
ONES FOR HIGHS THURSDAY.
HAVE FOLLOWED A BLEND OF THE MOS GUIDANCE THROUGH THE PERIOD ALLOWING
THE MAV NUMBERS TO TEMPER THE MET/S...WITH LITTLE IN THE WAY OF
TERRAIN ADJUSTMENTS GIVEN THE MOIST ENVIRONMENT. DID FAVOR THE MET
POPS THROUGH THE SHORT TERM...BUT HAD THEM TRANSLATED MORE TO THE
SOUTH OWING TO THE CONSENSUS FAVORING MORE SUPPRESSION OF THE FRONTAL
BOUNDARY FROM THE HIGH TO THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 AM EDT WED APR 4 2012
THE MODELS ARE IN GOOD AGREEMENT REGARDING THE EVOLUTION OF WEATHER
SYSTEMS FOR THE DAY 4-7 PERIOD. INITIALLY...SCATTERED RAIN SHOWERS
WILL BE PRESENT FROM THE TENNESSEE BORDER NORTHWARD TO THE HAL
ROGERS PARKWAY AND ALONG AND NORTH OF THE HIGHWAY 80 CORRIDOR. THESE
RAIN SHOWERS WILL LIKELY LINGER THROUGH 9 OR 10Z ACROSS THIS AREA ON
FRIDAY MORNING...BEFORE EXITING INTO VIRGINIA BY 13Z OR SO. AFTER
THAT...THE MODELS ALL AGREE THAT HIGH PRESSURE WILL BECOME FIRMLY
ESTABLISHED ACROSS THE OHIO AND TENNESSEE VALLEY AREAS THROUGH
SUNDAY MORNING. THE GFS AND ECMWF BOTH ARE QUICKLY MOVING A WEAK
FRONTAL BOUNDARY AND UPPER LEVEL TROUGH ACROSS THE REGION ON SUNDAY.
THESE FEATURES WILL JUST STRONG ENOUGH AND HAVE JUST ENOUGH MOISTURE
ASSOCIATED WITH THEM TO SPARK ISOLATED TO SCATTERED RAIN SHOWERS. AT
THIS TIME THE MODEL DATA INDICATE THAT THE ATMOSPHERE WILL ONLY BE
ABLE TO SUPPORT ISOLATED THUNDERSTORM ACTIVITY. WITH ALL THAT IN
MIND...THE INHERITED FORECAST FOR SUNDAY WAS ADJUSTED TO REFLECT
PRECIPITATION CHANCE THAT WERE A GOOD DEAL LOWER...AND MORE IN LINE
WITH THE LATEST MEXMOS DATA...WHICH WAS REFLECTIVE OF 20-30 PERCENT
PRECIPITATION PROBABILITIES ACROSS THE BOARD. ANOTHER AREA OF WEAK
HIGH PRESSURE WILL THEN BECOME ESTABLISHED ACROSS THE SUNDAY NIGHT
AND MONDAY. ANOTHER EVEN MORE ILL DEFINED FRONTAL BOUNDARY AND UPPER
TROUGH COMBO WILL BRING SCATTERED RAIN SHOWERS TO EASTERN KENTUCKY
MONDAY NIGHT AND TUESDAY. THE WEATHER...SKY COVER...AND
PRECIPITATION AMOUNT FORECASTS WERE ALL ADJUSTED BASED ON THE LOWER
PRECIPITATION PROBABILITIES. ACCOUNTING FOR THE AMOUNT OF CLOUD
COVER AND PRECIPITATION EXPECTED...AND WITH SOMEWHAT COOLER AIR
MASSES EXPECTED TO MOVE ACROSS THE AREA...TEMPERATURES WILL BE VERY
CLOSE TO NORMAL THROUGH MONDAY...AND MAY EVEN BE SEVERAL DEGREES
BELOW NORMAL NEXT TUESDAY AS COOLER AIR MAKES A FAIRLY DEEP
SOUTHWARD INTRUSION INTO THE EASTERN CONUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 235 AM EDT WED APR 4 2012
WITH THE WARM FRONT LYING ACROSS THE AREA...CONVECTION IS POSSIBLE AT
ALMOST ANYTIME AND ANYWHERE THROUGHOUT EAST KENTUCKY. DO EXPECT THE
ACTIVITY TO BE AT A MINIMUM THROUGH DAWN FOR MOST PLACES...EXCEPT AN
UPTICK IN THE NORTH TOWARD 12Z IN RELATION TO A PASSING SHORT WAVE.
OTHERWISE...WILL LET THE DIURNAL CYCLE DRIVE THE DEVELOPMENT AND
EXPANSION OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA THIS
AFTERNOON AND INTO THE EVENING. WITH THIS...HAVE ADDED VCTS INTO THE
TAFS AFTER 09Z AND A TEMPO FOR MVFR CONDITIONS IN ANY STORMS FOR THAT
PERIOD AROUND DAWN. FOLLOWING THIS...ANTICIPATE A LULL IN THE
ACTIVITY UNTIL MIDDAY FOR MOST OF THE AREA AND THEN CONVECTION
BLOSSOMING AGAIN FROM LATE AFTERNOON AND WELL INTO THE EVENING. ANY
STORM WILL BRING WITH IT MVFR CIGS AND VIS DOWN TO IFR OR LESS IN
HEAVY RAIN. WINDS THROUGH THE PERIOD WILL BE GENERALLY FROM THE WEST
AT 5 TO 10 KTS THROUGH THE PERIOD...THOUGH HIGHER IN AND AROUND ANY
STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM....AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
300 AM MDT WED APR 4 2012
.DISCUSSION...WRAP AROUND/JET RELATED PRECIPITATION CONTINUING OVER
EASTERN HALF OF NEW MEXICO ATTM. LATEST RUC SHOWS UPPER LOW WILL
MOVE VERY SLOWLY THIS MORNING...CENTERED OVER THE NORTHERN TX
PANHANDLE BY NOON. RAIN WAS INDICATED TO BE THE PREDOMINANT
PRECIPITATION TYPE WITH THE WEST TO EAST ORIENTED BAND STRETCHING
ACROSS LINCOLN COUNTY TO NEAR MILNESAND. WITH TEMPS NEAR
FREEZING...SNOW WAS ASSOCIATED WITH THE WRAP AROUND ECHOES FROM
ANGEL FIRE TO RATON AND CLAYTON. EXPECT MINIMAL ACCUMULATIONS AND
IMPACTS WITH THIS...AS COMPARED TO THE LAST 36 HOURS.
OTHERWISE...AREAS OF LOW CLOUDS AND FOG WILL PLAGUE THE RIO GRANDE
VALLEY EASTWARD THIS MORNING.
THE LINGERING PRECIPITATION SHOULD BE OVER WITH BY THIS AFTERNOON.
HIGH TEMPERATURES WILL BE WARMER OVERALL TODAY...AND ALTHOUGH THE
SURFACE GRADIENT ISN/T VERY STRONG COULD NOT RULE OUT SOME NORTHWEST
TO NORTHERLY BREEZES IN THE EAST...BUT ESPECIALLY NEAR THE TEXAS
BORDER WHERE FORECAST H7 WINDS ARE AROUND 30KT.
MODELS INDICATE HIGH LEVEL MOISTURE INCREASING TONIGHT ...MAYBE
ENOUGH TO KEEP FOG FROM DEVELOPING OVER AREAS WHICH RECEIVED
SIGNIFICANT SNOWFALL MONDAY NIGHT/TUESDAY. CONFIDENCE NOT THAT GREAT
BUT WENT AHEAD AND PUT PATCHY FOG IN THE GRIDS FOR THE SANGRE DE
CRISTO MOUNTAINS/NORTHEAST HIGHLANDS AND OVER TOWARDS
CAPULIN/FOLSOM...WHERE MELTING SHOULD CONTINUE DURING THE DAY TODAY.
THURSDAY AND FRIDAY FEATURE A WARMING TREND WITH TEMPERATURES BACK
ABOVE NORMAL. INCREASING SOUTHWEST FLOW ALOFT IS ANTICIPATED AS A
SYSTEM PASSES THROUGH THE NORTHERN ROCKIES. THIS IS MUCH FARTHER
NORTH THAN SHOWN A COUPLE OF DAYS AGO...SO WINDS SHOULDN/T GET TOO
UNRULY.
A SURFACE FRONT DROPPING INTO THE PLAINS ON SATURDAY APPEARS TO
BE ENOUGH OF A MECHANISM TO IGNITE A FEW THUNDERSTORMS BUT
INITIALLY MAINLY TO OUR EAST. HOWEVER...AS SURFACE HIGH PRESSURE
SETTLES SOUTHWARD INTO THE CENTRAL/SOUTHERN PLAINS...LOW LEVEL
MOISTURE INCREASES INTO OUR EASTERN PLAINS. THE GFS IN PARTICULAR
HAS BEEN PRETTY ENERGETIC DEVELOPING WIDESPREAD AMOUNTS OF
PRECIPITATION SUNDAY THROUGH MONDAY OVER THE EASTERN HALF OF NEW
MEXICO...DESPITE THE REGION BEING UNDER A RATHER SHARP RIDGE ALOFT.
BASED ON THE FORECAST POSITION OF THE RIDGE AXIS...THE ARGUMENT
COULD BE MADE THAT THE EASTERN SIDE OF THE STATE WILL BE UNDER
NORTHWEST FLOW ALOFT BUT IT WILL BE PRETTY WEAK. THE LATEST 00Z
ECMWF IS EVEN JUMPING ON THIS IDEA THOUGH NOT QUITE AS EXTREME.
CURRENT POP/WX GRIDS HAVE THIS TREND COVERED AT LEAST FOR NOW.
THE MIDDLE TO LATE WEEK PERIOD NEXT WEEK APPEARS TO BECOME MORE
UNSETTLED AS AN UPPER TROUGH PUSHES INTO THE GREAT BASIN AND HEADS
FOR NEW MEXICO. THERE COULD BE POTENTIAL FOR A CLOSED LOW TO DEVELOP
AS IT REACHES THE EASTERN SLOPES OF THE ROCKIES...BASED ON
GFS/ECMWF. THERE/S STILL QUITE A BIT OF TIME FOR
CHANGES...CONSIDERING THE NOW EXITING STORM SYSTEM WAS SUPPOSED TO
BE DRY AND WINDY UNTIL ONLY A COUPLE OF DAYS PRIOR.
&&
.AVIATION...AREAS OF LIGHT SNOW WILL AFFECT PORTIONS OF NORTHEAST NM
THROUGH 16Z RESULTING IN MVFR/IFR CIGS/VSBYS AT TIMES... ESPECIALLY
BETWEEN KLVS AND KRTN...AND NEAR THE NE NM/SE CO LINE. ELSEWHERE...
LOW CLOUDS AND FOG OR FREEZING FOG WILL CONTINUE TO DEVELOP/EXPAND
THROUGH DAYBREAK ESPECIALLY IN THE VALLEYS OF NC/NW NEW MEXICO THAT
RECEIVED SIGNIFICANT PRECIP DURING THE PAST 24 HOURS. HIGHEST
CONFIDENCE IN MVFR/BRIEF IFR CONDITIONS AT KSAF AND KABQ...AS WELL
AS KSKX AND THE UPPER RIO GRANDE VALLEY. PRECIP ENDING AND CIGS
RISING ACROSS NE NM BY MID- TO LATE MORNING AS THE STORM SYSTEM
PULLS AWAY AND LOW LEVEL DOWNSLOPE FLOW AND VFR CONDITIONS RETURN.
ELSEWHERE...ASIDE FROM MORNING LOW CLOUDS/FOG OR FREEZING FOG...VFR
CONDITIONS EXPECTED. KJ
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z.
&&
.FIRE WEATHER...TEMPERATURES QUICKLY REBOUND TODAY...ALTHOUGH MAXES
WILL REMAIN JUST SHY OF SEASONAL AVERAGES ACROSS MUCH OF THE CENTRAL
AND EAST. THE NORTHEAST WILL BE SLOWEST TO RECOVER AND HIGHS THERE
WILL BE 5 TO 10 DEGREES BELOW NORMAL. WITH THE WARMING....AFTERNOON
HUMIDITY VALUES WILL TREND DOWNWARD IN A BIG WAY ESPECIALLY CENTRAL
AND NORTH CENTRAL AREAS. RH VALUES LOOK TO BOTTOM OUT IN THE TEENS
ACROSS THE SOUTH AND WEST...WITH MOSTLY 20S TO NEAR 40 ELSEWHERE.
VENTILATION WILL BE VERY GOOD TO EXCELLENT FOR A VAST MAJORITY OF
THE AREA LATER TODAY THANKS TO DEEP LAYER NORTHWEST FLOW ON THE
BACKSIDE OF THE DEPARTING STORM SYSTEM. THIS WILL TRANSLATE TO
MODERATE NORTHWEST BREEZES FOR MANY AREAS...ESPECIALLY EAST OF THE
CENTRAL MOUNTAIN CHAIN AND PORTIONS OF WEST CENTRAL NEW MEXICO. A
BRISK NORTH TO NORTHWEST WIND WILL ALSO DEVELOP ACROSS THE NORTHEAST
ONCE AREAS OF LIGHT SNOW END AFTER MID OR LATE MORNING.
WEAK HIGH PRESSURE ALOFT SLIDES OVER THE AREA TONIGHT. GIVEN THE
EFFECTS OF MELTING SNOW ON BOUNDARY LAYER MOISTENING...LOW CLOUDS
AND FOG/FREEZING FOG MAY REVISIT THE VALLEYS OF NORTHERN NEW MEXICO
TOWARD DAYBREAK THURSDAY. OTHERWISE THE DRYING AND WARMING TREND
WILL CONTINUE THROUGH THE END OF THE WORK WEEK. VENTILATION RATES
WILL BE IN THE EXCELLENT CATEGORY BOTH DAYS FOR A VAST MAJORITY OF
THE AREA.
AFTERNOON AND EVENING WINDS WILL BE MORE NOTICEABLE THURSDAY AND
ESPECIALLY FRIDAY AS MID-LEVEL GRADIENTS TIGHTEN AND BECOME MORE
WEST TO SOUTHWEST BY FRIDAY. WESTERN AREAS AND THE NORTHEAST WILL BE
FAVORED FOR BREEZY CONDITIONS THURSDAY AFTERNOON WITH MORE
WIDESPREAD BREEZY/WINDY CONDITIONS ON FRIDAY. HOWEVER...RECENT
MODEL TRENDS NOW SUPPORT LESS OVERALL WIND IMPACTS ON FRIDAY AS THE
MAIN SHORTWAVE IS LIFTING OUT FARTHER NORTH. EVEN SO...DEEP MIXING
DURING THE AFTERNOON/EVENING WILL BRING THE HIGHER MOMENTUM AIR TO
THE SURFACE AND COMBINED WITH LOWERING RH/S WILL RESULT IN AN
INCREASING THREAT FOR LOW END CRITICAL FIRE WEATHER GROWTH
CONDITIONS MAINLY ACROSS THE EAST CENTRAL PLAINS.
WEAK RIDGE ALOFT INDICATED SATURDAY AND SUNDAY WITH LESS WIND
AREAWIDE...THOUGH STRENGTHENING SOUTH OR SOUTHEAST SURFACE GRADIENTS
LIKELY ACROSS THE FAR EAST. WE WILL BE MONITORING LOW LEVEL
MOISTURE RETURN ACROSS PORTIONS OF SOUTH CENTRAL AND SOUTHEAST NEW
MEXICO LATE IN THE WEEKEND INTO EARLY NEXT WEEK...AS THE LARGE SCALE
WIND PATTERN IS FAVORABLE TO ALLOW FOR A SUBTLE BUT POTENTIALLY
SIGNIFICANT INCREASE BEGINNING SUNDAY. THIS COULD RESULT IN A
THREAT OF HIGH BASED SHOWERS OR VIRGA AT A MINIMUM...AND POSSIBLY
DRYLINE-ENHANCED THUNDERSTORMS ACROSS THE FAR EAST. HOW FAR WEST
AND NORTH THIS VIRGA THREAT EXPANDS IS VERY UNCERTAIN...BUT AREAS
ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN WILL BE VERY
SUSCEPTIBLE AND CLIMATOLOGICALLY-FAVORED. KJ
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 66 35 73 37 / 0 0 0 0
DULCE........................... 58 25 66 30 / 10 0 0 0
CUBA............................ 57 30 66 33 / 5 0 0 0
GALLUP.......................... 66 30 68 32 / 0 0 0 0
EL MORRO........................ 59 27 66 30 / 0 0 0 0
GRANTS.......................... 63 29 68 31 / 0 0 0 0
QUEMADO......................... 63 33 69 33 / 0 0 0 0
GLENWOOD........................ 71 35 75 41 / 0 0 0 0
CHAMA........................... 51 28 59 28 / 20 0 0 0
LOS ALAMOS...................... 57 37 67 38 / 10 0 0 0
PECOS........................... 54 35 65 38 / 5 0 0 0
CERRO/QUESTA.................... 53 27 64 31 / 10 5 0 0
RED RIVER....................... 45 28 54 30 / 20 5 0 0
ANGEL FIRE...................... 46 26 56 30 / 30 5 0 0
TAOS............................ 55 27 65 31 / 10 0 0 0
MORA............................ 50 30 62 33 / 20 5 0 0
ESPANOLA........................ 62 30 71 38 / 5 0 0 0
SANTA FE........................ 57 36 68 39 / 5 0 0 0
SANTA FE AIRPORT................ 60 35 70 38 / 5 0 0 0
ALBUQUERQUE FOOTHILLS........... 65 41 73 44 / 0 0 0 0
ALBUQUERQUE HEIGHTS............. 65 44 73 46 / 0 0 0 0
ALBUQUERQUE VALLEY.............. 67 38 75 45 / 0 0 0 0
ALBUQUERQUE WEST MESA........... 66 42 74 45 / 0 0 0 0
LOS LUNAS....................... 69 38 77 44 / 0 0 0 0
RIO RANCHO...................... 65 42 74 45 / 0 0 0 0
SOCORRO......................... 72 40 79 47 / 0 0 0 0
SANDIA PARK/CEDAR CREST......... 62 35 71 40 / 0 0 0 0
TIJERAS......................... 64 37 73 40 / 0 0 0 0
MORIARTY/ESTANCIA............... 59 33 70 38 / 0 0 0 0
CLINES CORNERS.................. 58 36 68 40 / 5 0 0 0
GRAN QUIVIRA.................... 62 38 72 43 / 0 0 0 0
CARRIZOZO....................... 65 37 74 43 / 0 0 0 0
RUIDOSO......................... 58 41 68 47 / 0 0 0 0
CAPULIN......................... 49 32 67 37 / 40 5 0 0
RATON........................... 56 31 69 35 / 30 5 0 0
SPRINGER........................ 59 32 72 38 / 20 5 0 0
LAS VEGAS....................... 58 33 68 39 / 10 5 0 0
CLAYTON......................... 58 37 75 43 / 20 5 0 0
ROY............................. 60 35 73 42 / 10 5 0 0
CONCHAS......................... 66 38 79 45 / 10 0 0 0
SANTA ROSA...................... 68 38 79 44 / 10 0 0 0
TUCUMCARI....................... 69 39 81 45 / 10 0 0 0
CLOVIS.......................... 69 40 80 46 / 10 0 0 0
PORTALES........................ 70 40 81 46 / 10 0 0 0
FORT SUMNER..................... 72 41 84 46 / 10 0 0 0
ROSWELL......................... 77 43 87 48 / 5 0 0 0
PICACHO......................... 71 41 82 48 / 0 0 0 0
ELK............................. 68 41 77 47 / 0 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
510 AM EDT WED APR 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY, BRINGING SUNNY SKIES LATER THIS
MORNING AND BREEZY CONDITIONS. HIGH PRESSURE WILL KEEP QUIET
WEATHER OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT IMAGERY AND GROUND OBS STILL SHOWING CLOUD COVER OVER MOST OF
THE CWA, WITH SOME CLEARING FROM THE NW. THIS CLEARING WILL SLOWLY
CONTINUE UNTIL AROUND DAY BREAK WHEN MIXING BEGINS TO CLEAR IT OUT
SOMEWHAT FASTER. THIS WILL ALLOW FOR SUNNY SKIES LATER THIS
MORNING AND THE REST OF THE DAY. AS HIGH PRESSURE BUILDS IN, THE
PRESSURE GRADIENT WILL INCREASE OVER THE CWA, ALLOWING FOR WINDS
TO INCREASE WITH GUSTS TO AROUND 20 MPH. RELATIVE HUMIDITY WILL BE
FAIRLY DRY TODAY, DROPPING TO AROUND 30 PERCENT. MODELS HAVE MORE
MOISTURE THAN THAT, BUT THINKING IS THEY ARE OVER DOING SFC
MOISTURE, SO HAVE LOWERED DEW POINTS INTO THE UPPER 20S TO LOW 30S
TODAY. THE HRRR SEEMS TO HAVE ONE OF THE BEST HANDLES ON THE RH
TODAY. IT DOES SHOW INCREASING RH FROM THE NW THIS MORNING, ONLY
TO FALL OFF LATE MORNING AND AFTERNOON AS MIXING OCCURS. EVEN WITH
THE LOWERING RH, IT STILL SHOWS RH VALUES IN THE 40 PERCENT RANGE.
SO, STARTING THERE AND TAKING ABOUT 10 PERCENT OFF OF THAT, STILL
KEEPS FIRE WEATHER CONCERNS MARGINAL AT BEST. NOT TO MENTION, THE
PRECIP CRITERIA HAS NOT BEEN MET FOR NY, AS MUCH OF THE CWA
RECEIVED OVER A QUARTER INCH OF RAIN ON SUNDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE REMAINDER OF THE
WEEK. THIS WILL KEEP THE WEATHER QUIET. LOOKING AT TEMPS TONIGHT,
THEY WILL COOL TO THE LOWER 30S. THERE MAY BE SOME LOCALIZED AREAS
OF BELOW FREEZING TEMPS, BUT NOT EXPECTED TO BE WIDESPREAD AT THIS
TIME IN AREAS WHERE THE GROWING SEASON HAS STARTED. THUS, HAVE
OPTED NOT TO ISSUE ANY PRODUCTS AT THIS TIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
.0345 AM UPDATE... VERY FEW CHANGES MADE TO THE LONG TERM AS
PREVIOUS FORECAST HAD A GOOD HANDLE ON EXPECTED CONDITIONS. IN
GENERAL...DRY/SEASONAL CONDITIONS EXPECTED TOWARDS THE START OF
THE PERIOD WITH AN EVENTUAL SHIFT TOWARDS UNSETTLED CONDITIONS AND
BELOW NORMAL TEMPS EARLY NEXT WEEK AS AN UPPER VORTEX BECOMES
FIRMLY ESTABLISHED ACROSS EASTERN CANADA. BOTH GFS AND ECMWF
SHOWING SURPRISING AGREEMENT WITH THE EVOLUTION OF THIS
FEATURE...WITH BOTH AGREEING UPPER LOW WILL TAKE UP RESIDENCE
ACROSS THE UPPER ST. LAWRENCE VALLEY BY MONDAY.
UNFORTUNATELY...OUR REGION WILL BE EMBEDDED IN NORTHERLY FLOW TO
THE SYSTEM/S WEST WHICH WILL SET UP A FAVORABLE CORRIDOR FOR THE
PASSAGE OF UPPER SHORTWAVE DISTURBANCES ACROSS OUR REGION. BASED
ON FAVORABLE MODEL AGREEMENT...HAVE LOWERED DAYTIME HIGHS A FEW
DEGREES EACH DAY BEGINNING MON.
.PREVIOUS LONG TERM DISCUSSION...
THE LONG TERM STARTS OFF WITH HIGH PRESSURE IN CONTROL WITH FAIR
AND MAINLY CLEAR WX FOR FRI AND SAT AND MOST OF SUNDAY. LATER ON
SUNDAY...A WEAK FNTL SYSTEM MAY BRING AN INCREASE IN CLDS AND THE
CHC FOR A FEW -SHRA ON SUN NGT. AFTER THIS TIME MDLS ARE IN PRETTY
GOOD AGREEMENT THAT AN UPR TROF WILL BE AMPLIFYING OVER THE RGN
WITH A TREND TWDS COOLER AND WETTER CONDITIONS TAKING HOLD. WE
FOLLOWED HPC GDNC FOR THE MOST PART...BUT LOWERED MAXES A BIT FOR
EARLY NXT WEEK GIVEN MDL TRENDS AND LATEST MOS GDNC.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD DESPITE
PASSAGE OF WEAK SURFACE FRONT THIS MORNING. LATEST 11-3.9U
SATELLITE TRENDS SHOWING MID-LEVEL DECK EXITING OFF TOWARDS THE
SOUTHEAST THIS MORNING...WHICH WILL BE FOLLOWED BY A PERIOD OF
MOSTLY CLEAR SKIES AFTER 09-10Z TIME FRAME. CLOUDS WILL AGAIN BE ON
THE INCREASE THIS AFTERNOON AS UPPER-LEVEL DISTURBANCE BRUSHES
THE REGION FROM THE NORTH.
BRISK NW WINDS ARE ALSO EXPECTED TODAY AS A TIGHT PRESSURE
GRADIENT WILL REMAIN OVER THE REGION. BY LATE MORNING/AFTERNOON...GUSTS
MAY REACH AS HIGH AS 25 KTS AT ALL TAF SITES BEFORE WINDS BEGIN TO
WEAKEN THIS EVENING.
.OUTLOOK...
WED NGT TO SUN...VFR. POTNL FOR A PD OF MVFR CIGS ACRS CNTRL NY
S/SE OF LAKE ONTARIO LATE WED NGT INTO EARLY THU MRNG.
&&
.FIRE WEATHER...
WHILE THERE IS A HIGH FIRE DANGER IN SOME AREAS, RED FLAG CRITERIA
LOOKS TO NOT BE MET, OR FAIRLY MARGINAL IN SOME AREAS. FOR THE NEW
YORK AREA, RAIN ON SUNDAY OF MORE THAN A QUARTER OF AN INCH OVER A
LARGE AREA, HAS KEPT THE CRITERIA FROM BEING MET. ALSO, RELATIVE
HUMIDITY WILL DROP TODAY. HOWEVER, IT DOES LOOK TO REMAIN IN THE
LOW 30 PERCENT RANGE IN THE CATSKILL AREA. ALSO, WINDS ARE
EXPECTED TO BE GUSTY TODAY, WITH SOME GUSTS APPROACHING 25 MPH,
AGAIN, ESPECIALLY IN THE CATSKILL REGION. THIS, WHEN COMBINED WITH
LOW FUEL MOISTURE, WOULD CAUSE BORDERLINE CONDITIONS, BUT NOT
EXPECTING EXPLOSIVE FIRE GROWTH POTENTIAL AT THIS TIME.
TEMPS WILL BE NEAR FREEZING OVER MUCH OF THE AREA TONIGHT. RH
RECOVERY WILL BE MODERATE, WITH VALUES IN THE UPPER 60 TO MID 70
PERCENT RANGE.
FOR TOMORROW, RH WILL NOT BE AS LOW AND WINDS WILL ARE NOT
EXPECTED TO BE AS STRONG, THUS REDUCING THE THREAT OF REACHING
CRITICAL FIRE WEATHER CONDITIONS.
THIS WILL BE THE GENERAL RULE FOR THE REMAINDER OF THE WEEK AS
HIGH PRESSURE BUILDS IN AND REMAINS IN CONTROL THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...CMG
AVIATION...CMG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT WED APR 4 2012
.SYNOPSIS...
A STRONG BACK DOOR COLD FRONT WILL APPROACH FROM THE NORTH THIS
EVENING AND SURGE SOUTHWARD THROUGH THE AREA LATE TONIGHT AND
THURSDAY MORNING.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 315 AM WEDNESDAY...
OVERVIEW:
THE HEIGHT GRADIENT ALOFT WILL TIGHTEN OVER THE CAROLINAS AND
MID-ATLANTIC TODAY IN ASSOC/W MODEST HEIGHT FALLS IN ADVANCE OF AN
H5 TROUGH PROGRESSING SLOWLY S/SE FROM CANADA INTO THE LOWER GREAT
LAKES AND NEW ENGLAND. ALTHOUGH DPVA WITH THE AFOREMENTIONED TROUGH
WILL REMAIN WELL NORTH IN NEW ENGLAND...STRENGTHENING WESTERLY FLOW
ALOFT WILL RESULT IN A POTENTIAL FOR DPVA IN THE FORM OF MINOR
SHORTWAVES/MCVS ADVECTING INTO NC/VA FROM THE WEST THIS AFTERNOON
INTO TONIGHT. IN ADDITION TO AN MCV NOTED OVER CENTRAL NC (VIA
LATEST RUC DATA) AT 06Z...SEVERAL MCVS/DISTURBANCES WERE NOTED
UPSTREAM OVER THE CENTRAL/LOWER MS RIVER VALLEY THIS MORNING. IN THE
LOWER LEVELS...THE WARM FRONT PROGRESSING NORTH THROUGH SOUTHERN VA
AS OF 06Z WILL STALL OUT IN NORTHERN VA TODAY...THEN RETREAT
SOUTHWARD AS A BACK DOOR COLD FRONT THIS AFTERNOON AND
EVENING...WITH A PRE-FRONTAL TROUGH PROGRESSING INTO CENTRAL NC BY
18-21Z. THE COLD FRONT WILL PROGRESS SOUTH THROUGH CENTRAL NC LATE
TONIGHT/THU MORNING.
PRECIPITATION CHANCES:
THOUGH STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) WERE PRESENT OVER
NC/VA AND THE OH VALLEY AT 06Z THIS MORNING...MODEL GUIDANCE
CONTINUES TO INDICATE LAPSE RATES WEAKENING TO 5.5-6 C/KM BETWEEN
18-00Z. HOWEVER...AN UNSEASONABLY WARM/MOIST AIRMASS WILL BE IN
PLACE ACROSS CENTRAL NC TODAY...AND THIS SHOULD ALLOW FOR 500-1000
J/KG OF MLCAPE DURING PEAK HEATING...PERHAPS 1000-1500 J/KG IF
MID-LEVEL LAPSE RATES REMAIN NEAR OR SLIGHTLY ABOVE 6 C/KM...
PRIMARILY BETWEEN 18-21Z. GIVEN A LOW-LEVEL FOCUS (PRE-FRONTAL
TROUGH) AND A POTENTIAL FOR DISTURBANCES ALOFT ADVECTING INTO THE
AREA FROM THE WEST IN THE PRESENCE OF MARGINAL TO MODERATE
INSTABILITY...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP
BETWEEN 18-21Z THIS AFTERNOON. HOWEVER...UNCERTAINTY IN THE TIMING
AND LOCATION OF CONVECTION PERSISTS...PRIMARILY IN ASSOCIATION WITH
THE TRACK/EVOLUTION OF UPSTREAM DISTURBANCES ADVECTING TOWARD NC/VA
VIA STRENGTHENING WESTERLY FLOW ALOFT. THE LATEST 00Z WRF-NMM
INDICATES DRY CONDITIONS THROUGH 18Z...SHOWING ISOLD/SCT CONVECTION
DEVELOPING OVER THE MOUNTAINS AND MOVING DOWNSTREAM INTO THE CENTRAL
NC BY 21Z THIS AFTERNOON...WITH ADDITIONAL CONVECTION DEVELOPING IN
VICINITY OF THE PRE-FRONTAL TROUGH OVER CENTRAL NC. THE 00Z WRF-ARW
SHOWS SCATTERED CONVECTION DEVELOPING OVER CENTRAL NC PRIMARILY IN
ASSOC/W THE PRE-FRONTAL TROUGH BETWEEN 18-21Z. AT THIS TIME WILL NOT
CHANGE PRECIP CHANCES MUCH FROM THE PREVIOUS FORECAST...SHOWING A
40% CHANCE FOR SHOWERS/STORMS...WITH THE BEST CHANCE BETWEEN 19Z
THIS AFTERNOON AND 01Z THIS EVENING. THOUGH INSTABILITY WILL BEGIN
TO WANE AFTER SUNSET...ADDITIONAL CONVECTION WILL BE POSSIBLE IN
ASSOC/W THE BACK DOOR COLD FRONT PROGRESSING SOUTH THROUGH VA INTO
CENTRAL NC OVERNIGHT. HOWEVER...THIS MAY DEPEND ON HOW MUCH
STABILIZATION OCCURS IN ASSOC/W CONVECTION DURING THE AFTERNOON AND
EVENING. WILL MAINTAIN A SLIGHT CHANCE (20%) NORTH TO LOW CHANCE
(30%) SOUTH OVERNIGHT...WITH ISOLD THUNDERSTORMS MORE LIKELY IN
SOUTHERN PORTIONS OF THE AREA.
TEMPERATURES:
1000-850 MB THICKNESSES ARE PROGGED AT 1390-1400 METERS THIS
AFTERNOON. THESE THICKNESSES SUPPORT HIGHS IN THE LOWER/MID 80S...
OR 82-85F. ALTHOUGH A FAIR AMOUNT OF MID/UPPER LEVEL CLOUD COVER IS
PRESENT THIS MORNING...EXPECT A REASONABLE POTENTIAL FOR SOME
CLEARING AND ENOUGH SUNSHINE FOR TEMPS TO REACH THE LOWER/MID 80S.
LOWS TONIGHT WILL DEPEND ENTIRELY ON THE TIMING/PROGRESS OF THE BACK
DOOR COLD FRONT SURGING SOUTH INTO THE AREA. AT THIS TIME...EXPECT
LOWS TO RANGE FROM THE LOWER/MID 50S IN THE NORTH/NE TO THE UPPER
50S AND LOWER 60S IN THE SOUTH.
SEVERE THREAT:
THE SPC DAY 1 OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS TODAY
OVER MOST OF CENTRAL NC. AS WESTERLY FLOW ALOFT STRENGTHENS...0-6 KM
BULK SHEAR VALUES IN CENTRAL NC ARE EXPECTED TO INCREASE TO 25-35 KT
THIS AFT/EVE...FURTHER INCREASING TO 30-40 KT AFTER 00Z. 0-6KM BULK
SHEAR VALUES WILL CERTAINLY BE SUPPORTIVE OF MULTICELL
ORGANIZATION...AND MAY BE AT THE LOW-END THRESHOLD FOR SUPERCELLULAR
ORGANIZATION...PRIMARILY AFTER 00Z...OR IF THE HEIGHT GRADIENT ALOFT
TIGHTENS/MID-LEVEL FLOW ACCELERATES IN ADVANCE OF AN UPPER LEVEL
DISTURBANCE PROGRESSING INTO THE AREA THIS AFT/EVE (SHOULD THAT
OCCUR). STEEP LOW-LEVEL LAPSE RATES ASSOC/W STRONG DIURNAL HEATING
WILL CONTRIBUTE TO RELATIVELY HIGH DCAPE AND THE POTENTIAL FOR
STRONG COLD POOLS THIS AFT/EVE. WITH THE ABOVE IN MIND...EXPECT THE
BEST CHANCE FOR SEVERE WEATHER FROM 3-10 PM...WITH A PRIMARY THREAT
OF DAMAGING WINDS OWING TO STEEP LOW-LEVEL LAPSE RATES AND
RELATIVELY SPEEDY MID-LEVEL FLOW. SEVERE HAIL APPEARS LESS LIKELY
GIVEN WEAK MID-LEVEL LAPSE RATES AND BULK SHEAR VALUES ON THE
LOW-END OF/OR UNSUPPORTIVE OF ROTATING UPDRAFTS. GIVEN STRONG
HEATING AND STEEP LOW-LEVEL LAPSE RATES...IF CONVECTION INITIATES ON
THE HIGHER TERRAIN AND PROGRESSES EAST INTO CENTRAL NC DURING THE
MID/LATE AFTERNOON...A LINE OF STORMS (ORGANIZING ALONG OUTFLOW)
COULD DEVELOP AND POSE A THREAT FOR RELATIVELY WIDESPREAD DAMAGING
WINDS. -VINCENT
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 310 AM WEDNESDAY...
AN UPPER LOW CURRENTLY LIFTING OUT OF NORTHEAST NM WILL DRIFT EAST
ACROSS THE MID MS RIVER VALLEY WEDNESDAY NIGHT... AND THEN BEGIN TO
MOVE SOUTHEAST TOWARD AL/GA ON THURSDAY AS IT APPROACHES THE
SOUTHERN EDGE OF BROAD CYCLONIC FLOW OVER THE NORTHEAST US. A COLD
FRONT AND/OR REMNANT CONVECTIVE OUTFLOW SHOULD BE NEAR THE
NC/SC BORDER BY 12Z THURSDAY...WHERE A FEW ISOLATED SHOWERS CANNOT
BE RULED OUT DURING THE MORNING HOURS. HOWEVER...MOST OF THE
CENTRAL NC SHOULD BE DRY THROUGH THURSDAY AFTERNOON AS A SURFACE
HIGH PRESSURE RIDGE SETTLES IN BEHIND THE FRONT AND A WEAK SHORTWAVE
UPPER RIDGE SHIFTS ACROSS NC AHEAD OF THE APPROACHING UPPER LOW.
WHILE FORECAST SOUNDINGS SUGGEST THE BOUNDARY LAYER WILL BE SLOW TO
SATURATE UNTIL LATER THURSDAY EVENING...THE LOW
LEVEL COLD ADVECTION BEHIND THE FRONT SHOULD BE HELP TO LOCK IN
STRATUS AT 2-3K FT WHERE MOISTURE WILL ALREADY EXIST. THUS...TEMPS
WILL STRUGGLE TO RISE UNTO THE LOW TO MID 60S...A GOOD 20 DEGREES
COOLER THAN WEDNESDAY.
FORCING FOR ASCENT...IN THE FORM OF INCREASING DIVERGENCE
ALOFT...WEAK LOW LEVEL WARM ADVECTION AND 60-80M HEIGHT FALLS...WILL
ARRIVE THURSDAY EVENING AS THE UPPER LOW DIVES THROUGH AL/GA. WHILE
THERE HAS BEEN GOOD MODEL CONSISTENCY IS THE GENERAL TRACK OF THE
UPPER AND SURFACE LOWS...THERE ARE STILL 100-200 MILE DIFFERENCES
THAT WILL IMPACT HOW FAR NORTH INTO NC BETTER RAIN COVERAGE WILL
EXTEND. MOST OF THE SHOWERS WILL PASS TO OUR SOUTH THURSDAY NIGHT
AS THE SURFACE LOW DEVELOPS AND MOVES TO NEAR SAVANNAH BY 06-12Z
FRIDAY. HOWEVER...A SHORTWAVE DROPPING SOUTH OUT OF EASTERN CANADA
INTO THE MID-ATLANTIC STATES SHOULD HELP DRAW MOISTURE NORTH INTO
THE VICINITY OF THE 925-850MB FRONT WHICH IS FORECAST TO LIE ACROSS
THE CAROLINAS. MODELS HAVE BEEN SHOWING AN AREA OF INCREASE LOW
LEVEL FGEN DEVELOPING OVER NC LATER FRIDAY NIGHT...SO WHILE THE BEST
SURFACE CONVERGENCE AND UPPER FORCING WILL BE JUST TO OUR SOUTH...WE
SHOULD SEE PRECIP EXPAND AND INTENSIFY NORTHWARD ACROSS SOUTHERN AND
EASTERN NC OVERNIGHT. WE DO NOT EXPECT ANY CONVECTION THURSDAY
NIGHT AS LOW LEVELS WILL BE STABLE...MID LEVEL LAPSE RATES WILL BE
WEAK... AND THE STRONGEST UPPER FORCING WILL BE TO OUR SOUTH.
HOWEVER...IF THE SURFACE LOW TRACKS SLIGHTLY NORTH OF THE CURRENT
FORECAST...THERE COULD BE ENOUGH INSTABILITY ACROSS THE SOUTHERN
PIEDMONT AND SANDHILLS TO SUPPORT A FEW ISOLATED THUNDERSTORMS.
FORECAST POPS ARE ALREADY HIGH ACROSS THE SOUTH AFTER 21Z
THURSDAY...EXPANDING NORTHWARD AFTER 03Z...WHICH SEEMS SUFFICIENT
FOR THE CURRENT FORECAST PACKAGE. LOWS IN THE UPPER 40S.
THE SURFACE LOW SHOULD BE OFF THE SC COAST BY 12Z FRIDAY..WITH
PRECIP ENDING FROM WEST TO EAST DURING THE DAY. THE MSLP GRADIENT
ON THE BACK SIDE OF THE SURFACE LOW WILL BE FAIRLY TIGHT...WITH MOST
MODELS SHOWING A 15-20KT NORTHEASTERLY WIND OVER THE COASTAL PLAIN
FRIDAY MORNING. THE DEPARTING LOW WILL ALSO DRAW DRIER AIR IN FROM
THE NORTH AS WINDS BEGIN TO TURN TO NORTH-NORTHWESTERLY FRIDAY
AFTERNOON. FORECAST SOUNDINGS NOW SHOW MOST OF THE CENTRAL BREAKING
OUT FRIDAY...ALTHOUGH MODELS OFTEN HAVE A TENDENCY TO SCOUR LOW
LEVEL MOISTURE TOO QUICKLY IN THE ABSENCE OF A FRONTAL SYSTEM.
BECAUSE OF THIS...THE HIGH TEMP FORECAST FOR FRIDAY IS SOMEWHAT
UNCERTAIN...BUT IT IS POSSIBLE THAT AREA SIN THE WEST COULD BREAK
OUT AND BE AS WARM IF NOT WARMER THAN AREAS IN THE EAST. WILL
FORECAST HIGHS GENERALLY AROUND 60.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 350 AM WEDNESDAY...
HIGH PRESSURE OVER THE GREAT LAKES WILL BRIEFLY BUILD SOUTH ACROSS
MUCH OF THE EASTERN US THIS WEEKEND...WHILE SEVERAL SHORTWAVES OVER
EASTERN CANADA AND THE NORTHERN US WRAP UP OVER NEW ENGLAND AND LEAD
TO A DEEP TROUGH ALONG THE EAST COAST NEXT WEEK. RAIN CHANCES
APPEAR TO BE LOW BUT ALSO LESS PREDICTABLE DUE TO THE NORTHWESTERLY
FLOW REGIME...ESPECIALLY FROM SUNDAY NIGHT ONWARD. HIGHS WARMING
INTO THE LOW TO MID 70S BY SUNDAY WILL DROP BACK INTO THE 60S FOR
THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 135 AM WEDNESDAY...
24-HR TAF PERIOD:
WEAKENING SHOWERS AND STORMS OVER RICHMOND/SCOTLAND COUNTIES AT 05Z
MAY AFFECT THE FAY TERMINAL BETWEEN 06-09Z THIS MORNING. ASIDE FROM
THAT AND A SMALL POTENTIAL (SREF PROBS <20%) FOR SUB-VFR CEILINGS OR
VISBYS IN THE 09-12Z TIME FRAME...EXPECT VFR CONDITIONS TO
PREDOMINATE THROUGH 18Z THIS AFTERNOON. BY MID TO LATE AFTERNOON...
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO BE POSSIBLE AT ALL TAF
SITES IN ADVANCE OF A STRONG BACK DOOR COLD FRONT APPROACHING FROM
THE NORTH...WITH SHOWERS/STORMS PERSISTING IN SOME AREAS THROUGH THE
END OF THE TAF PERIOD. WINDS WILL BE WEST OR SW AT 5-10 KT THROUGH
00Z THIS EVENING...BECOMING NORTH AND EVENTUALLY NORTHEAST BY THE
END OF THE TAF PERIOD.
LOOKING AHEAD:
BREEZY NORTHEAST WINDS (10-15 KT GUSTING TO 20 KT) CAN BE EXPECTED
IN THE WAKE OF THE BACK DOOR COLD FRONTAL PASSAGE BETWEEN 09-18Z
THURSDAY...ALONG WITH OVERCAST CEILINGS BETWEEN 3000-4500 FT AGL.
AFTER 18Z THU INTO THU NIGHT...MVFR CONDITIONS AND LIGHT RAIN ARE
EXPECTED IN ASSOC/W A DEVELOPING LOW PRESSURE SYSTEM OFF THE
SOUTHEAST COAST. IFR CONDITIONS WILL BE POSSIBLE. MVFR/IFR CEILINGS
ARE EXPECTED TO LIFT AND SCATTER OUT BETWEEN 12-18Z FRIDAY IN
ASSOC/W DRY AIR ADVECTING INTO THE AREA VIA BREEZY NNE FLOW. VFR
CONDITIONS ARE EXPECTED TO PERSIST FROM EARLY FRIDAY AFTERNOON INTO
THE WEEKEND. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
312 AM EDT WED APR 4 2012
.SYNOPSIS...
A SERIES OF WEAK DISTURBANCES ALOFT...FRONTS AND A MORE POTENT
STORM SYSTEM WILL KEEP CONDITIONS UNSETTLED THROUGH FRIDAY. SPRING
LIKE CONDITIONS QUICKLY RETURN FOR THE WEEKEND AND CONTINUE INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM...HRRR MODEL OUTPUT INDICATES THE CLUSTER OF
CONVECTION ACROSS THE CENTRAL PORTIONS OF THE CAROLINAS IS PROGGED
TO MAKE SLOW EASTWARD PROGRESS...POSSIBLY REACHING THE WESTERN EDGE
OF THE ILM CWA AT OR UP TO A FEW HRS AFTER MIDNIGHT. BY THAT
TIME...INSTABILITY WILL BE LACKING ESPECIALLY HAVING TRACKED INTO AN
ATM ALREADY NONCONDUCIVE FOR TSRA ACTIVITY TO START WITH. WEAK MID
LEVEL VORTICIES OVER THE WEST/CENTRAL CAROLINAS ARE AIDING THE
FORCING NEEDED TO SUSTAIN THIS CONVECTION AS IT APPROACHES THE ILM
CWA FROM THE WEST DURING THE OVERNIGHT. AS INDICATED B4...HRRR SFC
BASED CAPE BASICALLY NON-EXISTENT ACROSS THE ILM CWA BY THE TIME
THIS ACTIVITY REACHES THE OUTSKIRTS OF THE ILM CWA. WITH THIS
SAID...WILL CONTINUE CURRENT TREND WITH ONLY LOW CHANCE POPS
OVERNIGHT...MAINLY ALONG THE WEST THROUGH NORTHWEST OUTLINE OF THE
ILM CWA. DUE TO LATEST SAT IMAGERY TRENDS AND SFC OBS...CURRENT
FORECAST OF SKY CONDITIONS LOOKS AOK WITH NO CHANGES NEEDED.
FOR MIN TEMP FORECAST AND OVERNIGHT DEWPOINTS...SOME TWEAKING
UPWARDS NEEDED BY 1 TO AS MUCH AS 3 DEGREES BASED ON LATEST SFC OBS
AND LAPS/MSAS ANALYSIS TRENDS...AND WITH SOME AID FROM THE LATEST
RUNS OF THE HRRR AND RUC.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3:00 AM WEDNESDAY...MID LEVEL CYCLONE WILL MOVE QUICKLY ACROSS THE
SOUTHEAST THROUGH THE PERIOD. THE SURFACE LOW WILL MOVE ALONG THE
BAROCLINIC ZONE JUST SOUTH OF THE NC/SC BORDER. HPC FAVORS THE GFS
SOLUTION AS THE NAM IS HAVING INITIALIZATION ISSUES.
FOR OUR AREA...ISENTROPIC LIFT IN THE 290-300K LAYER INCREASES
STEADILY FROM 0000 THROUGH 1200 FRIDAY WITH THE BEST OMEGA ALONG THE
SOUTH CAROLINA AREAS. INCREASED POPS ACROSS THE BOARD WITH THIS
PACKAGE TO LOW END CATEGORICAL SOUTH TO NORTH. THE NORTH CAROLINA
COAST MAY FARE BETTER DURING THE DAY FRIDAY AS MID LEVEL
FRONTOGENESIS MOVES ACROSS THE AREA. BASED ON LIMITED
INSTABILITY...HAVE ALL BUT REMOVED THUNDER FROM THE
FORECAST...KEEPING ISOLATED EARLY THURSDAY. STORM TOTAL QPF AMOUNTS
RANGE FROM APPROXIMATELY ONE THIRD OF AN INCH NORTH TO JUST UNDER
EXTREME SOUTHERN AREAS.
FOLLOWED GFS/MAV NUMBERS FOR THE TEMPERATURE FORECAST BUT OVERALL
MAV AND MET NUMBERS ARE CLOSE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3:00 AM WEDNESDAY...RATHER UNEVENTFUL CONDITIONS
SATURDAY AND SUNDAY AS HIGH PRESSURE SETTLES OVER THE AREA UNDER THE
DEAMPLIYFING UPPER LEVEL PATTERN. AIR MASS MODIFICATION WILL ALLOW
MAX TEMPERATURES TO REBOUND QUICKLY TO THE MIDDLE TO UPPER 70S
SUNDAY AND MORESO ON MONDAY. MEDIUM RANGE MODELS (THE LATEST
OPERATIONAL GFS AND CANADIAN) WANT TO DEVELOP A DEEPER EAST COAST
TROUGH TUESDAY. THE ECMWF IS NOT QUITE ON BOARD ALTHOUGH THE
ENSEMBLE MEAN DOES HAVE MORE AMPLITUDE WHEN COMPARED TO THE
DETERMINISTIC MODEL. CERTAINLY NO COMPELLING REASON TO DEVIATE FROM
THE FORECAST AT THIS POINT BUT A DEEPER TROUGH COULD BRING 850MB
TEMPERATURES TANTALIZINGLY CLOSE TO FREEZING.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...SHOWERS AND THUNDERSTORMS WILL BE WEAKENING ACROSS THE
INLAND TERMINALS THROUGH 08Z AS THEY CONTINUE E...PERHAPS AS FAR E
AS CRE AND MYR AFTER 08Z.
MODERATE CONFIDENCE IN IFR STRATUS ALONG THE COAST AFTER
08Z...OTHERWISE MVFR CEILINGS AND OR VISIBILITIES WILL BE LARGELY
THE RULE THROUGH SUNRISE.
INCREASING PRECIPITABLE WATER VALUES AND CAPES COUPLED WITH HEATING
WILL PROVIDE AN ENVIRONMENT CONDUCIVE FOR AT LEAST SCATTERED
CONVECTION THIS AFTERNOON. LOOK FOR THE RESULTANT BOUNDARY TO KICK
OFF A FEW...WITH MORE SCATTERED CONVECTION INLAND. WINDS WILL BE
SOUTHWESTERLY ALL DAY...GUSTY BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS
WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM TUESDAY...CONTINUED MINOR ADJUSTMENTS TO WINDS
OVERNIGHT...MAINLY CONTINUED DUE TO THE SLOW VEERING OF WIND
DIRECTIONS FROM THE S TO SW AS A DIFFUSE WARM FRONT LIFTS ACROSS...
AND NORTH OF THE ILM WATERS DURING THE OVERNIGHT. SPEEDS IN GENERAL
TO REMAIN 10 TO OCCASIONALLY 15 KT. SIGNIFICANT SEAS WILL RUN 2 TO 3
FT THROUGHOUT. A 1 TO 2 FT EASTERLY GROUND SWELL AT 9-11 SECOND
PERIODS WILL DOMINATE SIGNIFICANT SEAS...WITH A 1-2 FOOT 3 TO 5
SECOND PERIOD WIND DRIVEN CHOP ADDING A FOOT OR 2 TO THE OVERALL
SIG. SEAS. COULD POSSIBLY SEE A FEW 4 FOOTERS ACROSS THE SHALLOW
SHOALS OFF CAPE FEAR BUT CONTINUED NOT ENOUGH OF AN OCCURRENCE TO
PLACE IN THE CWF.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3:00 AM WEDNESDAY...WIND SHIFT WILL BE UNDERWAY AT THE
BEGINNING OF THE PERIOD AS A FRONT BISECTS THE WATERS. BY LATE
AFTERNOON ALL WATERS SHOULD SEE NORTHEASTERLY WINDS. LOW PRESSURE
RIDES TO THE SOUTH VEERING WINDS TO ALMOST DUE EAST BY 0600 UTC
FRIDAY BEFORE PULLING AWAY FRIDAY WITH WINDS SHIFTING BACK TO
NORTHEAST. FOLLOWED THE GFS WHICH HAS VERY STRONG WINDS FROM
FRIDAY AFTERNOON AND EVENING. COULD SEE SEVERAL GUSTS INTO THE
GALE CRITERIA AND THIS WILL NEED TO BE MONITORED. SEAS ARE MAINLY
A CONCERN FRIDAY AS THE WINDS PICK UP STEAM. HIGH CONFIDENCE ON
SMALL CRAFT SEAS DEVELOPING BY 1200 UTC WITH THE EXCEPTION OF
AMZ256. ALL WATERS SHOULD SEE WELL OVER SIX FEET BY MIDDAY.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3:00 AM WEDNESDAY...HIGH PRESSURE WILL BUILD IN
ACROSS THE WATERS THROUGH THE PERIOD. NORTHEAST WINDS ON THE ORDER
OF 20-25 KNOTS INITIALLY WILL QUICKLY SUBSIDE TO 10-15 BY SUNDAY AM
AS THE AXIS OF HIGH PRESSURE REPOSITIONS ALONG THE APPALACHIANS.
RESIDUAL HIGH SEAS OF 6-8 FEET WILL FOLLOW CLOSE BEHIND DROPPING TO
2-4 FEET BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...RJD
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HDL/RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
140 AM EDT WED APR 4 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE CAROLINAS WEDNESDAY NIGHT
AND EARLY THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD AIR FRIDAY
NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN ACROSS THE
CAROLINAS. HIGH PRESSURE WILL WEAKEN AS IT MOVES OFFSHORE ON MONDAY
AS YET ANOTHER COLD FRONT APPROACHES FROM THE NORTHWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM...HRRR MODEL OUTPUT INDICATES THE CLUSTER OF
CONVECTION ACROSS THE CENTRAL PORTIONS OF THE CAROLINAS IS PROGGED
TO MAKE SLOW EASTWARD PROGRESS...POSSIBLY REACHING THE WESTERN EDGE
OF THE ILM CWA AT OR UP TO A FEW HRS AFTER MIDNIGHT. BY THAT
TIME...INSTABILITY WILL BE LACKING ESPECIALLY HAVING TRACKED INTO AN
ATM ALREADY NONCONDUCIVE FOR TSRA ACTIVITY TO START WITH. WEAK MID
LEVEL VORTICIES OVER THE WEST/CENTRAL CAROLINAS ARE AIDING THE
FORCING NEEDED TO SUSTAIN THIS CONVECTION AS IT APPROACHES THE ILM
CWA FROM THE WEST DURING THE OVERNIGHT. AS INDICATED B4...HRRR SFC
BASED CAPE BASICALLY NON-EXISTENT ACROSS THE ILM CWA BY THE TIME
THIS ACTIVITY REACHES THE OUTSKIRTS OF THE ILM CWA. WITH THIS
SAID...WILL CONTINUE CURRENT TREND WITH ONLY LOW CHANCE POPS
OVERNIGHT...MAINLY ALONG THE WEST THROUGH NORTHWEST OUTLINE OF THE
ILM CWA. DUE TO LATEST SAT IMAGERY TRENDS AND SFC OBS...CURRENT
FORECAST OF SKY CONDITIONS LOOKS AOK WITH NO CHANGES NEEDED.
FOR MIN TEMP FORECAST AND OVERNIGHT DEWPOINTS...SOME TWEAKING
UPWARDS NEEDED BY 1 TO AS MUCH AS 3 DEGREES BASED ON LATEST SFC OBS
AND LAPS/MSAS ANALYSIS TRENDS...AND WITH SOME AID FROM THE LATEST
RUNS OF THE HRRR AND RUC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...VERY LOW AMPLITUDE TROUGHINESS/WNW FLOW MOVES
OVER THE REGION ON WEDNESDAY IN THE MID LEVELS WHILE LOW LEVELS
CONTINUE TO ADVECT WARMTH AND MOISTURE. A FEW WEAK EMBEDDED MID
LEVEL SHORTWAVES WILL PROVIDE SOME ASCENT THOUGH THE MAIN ENERGY
WILL STREAK ACROSS THE NORTHERN FL PENINSULA. LOW END CHANCE/SCT
COVERAGE APPEARS WARRANTED. LOW 80S EXPECTED FOR A HIGH TEMP FOR ALL
BUT COASTAL LOCALS WHERE JUST ENOUGH ONSHORE COMPONENT EXPECTED TO
TEMPER VALUES...MOST PRONOUNCED ALONG BRUNSWICK CTY. BACKDOOR COLD
FRONT ENTERS FROM THE NORTH BY ABOUT 06Z WED NIGHT. THIS SHOULD LEAD
TO A BRIEF PUSH OF COOLER AND DRIER AIR WHERE PRECIP MAY TAKE A
BREAK LATE WEDNESDAY NIGHT. THIS UNDERCUTTING AIRMASS WILL THEN
START BEING OVERRUN BY A RENEWED SENSE OF WARM AND MOIST ADVECTION
AS THE SOUTHERN BRANCH CUTOFF OPENS UP AND HEADS EAST. THURSDAY WILL
BECOME INCREASINGLY UNSETTLED WITH RAIN CHANCES AND MORESO AMOUNTS
HIGHLY HINGING UPON SOME MODEL DISCREPANCIES. THE HIGH GFS AMOUNTS
APPEAR ON THE HIGH SIDE AND THE FCST FOLLOWS THE DRIER WRF MORE
CLOSELY. HIGH RAIN CHANCES ROUND OUT THE PERIOD AS THE UPPER LOW
TRANSFERS ENERGY TO LOW PRESSURE DEVELOPING OFF THE COAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...BEST CHANCE FOR RAIN IN THE PERIOD WILL BE AT
THE START OF THE PERIOD AS A SOUTHERN STREAM 5H CUTOFF MOVES ACROSS
THE AREA. SURFACE AND UPPER LOW WILL EXIT OFF THE COAST DURING FRI
BRINGING AN END TO PRECIP LATE IN THE DAY. WELL BELOW CLIMO TEMPS
FRI/FRI NIGHT WITH AREA UNDER THE 5H TROUGH/LOW. TEMPS START
TRENDING TO NORMAL SAT AS DEEPER NORTHWEST FLOW DEVELOPS AND THINGS
DRY OUT. REMAINDER OF THE PERIOD WILL BE DRY WITH 2 COLD FRONT
CROSSING THE AREA LATE IN THE PERIOD. FIRST COLD FRONT PASSES DRY ON
MON BUT IS FOLLOWED BY LIMITED COLD ADVECTION AS WINDS QUICKLY
BECOME SOUTHERLY AHEAD OF NEXT...MUCH STRONGER COLD FRONT...CROSSING
THE AREA TUE.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...SHOWERS AND THUNDERSTORMS WILL BE WEAKENING ACROSS THE
INLAND TERMINALS THROUGH 08Z AS THEY CONTINUE E...PERHAPS AS FAR E
AS CRE AND MYR AFTER 08Z.
MODERATE CONFIDENCE IN IFR STRATUS ALONG THE COAST AFTER
08Z...OTHERWISE MVFR CEILINGS AND OR VISIBILITIES WILL BE LARGELY
THE RULE THROUGH SUNRISE.
INCREASING PRECIPITABLE WATER VALUES AND CAPES COUPLED WITH HEATING
WILL PROVIDE AN ENVIRONMENT CONDUCIVE FOR AT LEAST SCATTERED
CONVECTION THIS AFTERNOON. LOOK FOR THE RESULTANT BOUNDARY TO KICK
OFF A FEW...WITH MORE SCATTERED CONVECTION INLAND. WINDS WILL BE
SOUTHWESTERLY ALL DAY...GUSTY BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS
WITH WIDESPREAD IFR FRIDAY. VFR SATURDAY AND SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM TUESDAY...CONTINUED MINOR ADJUSTMENTS TO WINDS
OVERNIGHT...MAINLY CONTINUED DUE TO THE SLOW VEERING OF WIND
DIRECTIONS FROM THE S TO SW AS A DIFFUSE WARM FRONT LIFTS ACROSS...
AND NORTH OF THE ILM WATERS DURING THE OVERNIGHT. SPEEDS IN GENERAL
TO REMAIN 10 TO OCCASIONALLY 15 KT. SIGNIFICANT SEAS WILL RUN 2 TO 3
FT THROUGHOUT. A 1 TO 2 FT EASTERLY GROUND SWELL AT 9-11 SECOND
PERIODS WILL DOMINATE SIGNIFICANT SEAS...WITH A 1-2 FOOT 3 TO 5
SECOND PERIOD WIND DRIVEN CHOP ADDING A FOOT OR 2 TO THE OVERALL
SIG. SEAS. COULD POSSIBLY SEE A FEW 4 FOOTERS ACROSS THE SHALLOW
SHOALS OFF CAPE FEAR BUT CONTINUED NOT ENOUGH OF AN OCCURRENCE TO
PLACE IN THE CWF.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...PREFRONTAL FLOW REGIME CRANKS UP AS WEDNESDAY
PROGRESSES AND THE GRADIENT BECOMES PINCHED BETWEEN WEST ATLANTIC
HIGH AND THE APPROACHING BOUNDARY. WEDNESDAY NIGHT THIS MODERATELY
STRONG WIND FIELD WILL START VEERING WITH THE APPROACH OF THE
BOUNDARY. BEING A BACKDOOR COLD FRONT RATHER THAN A MORE CLASSICAL
BOUNDARY COMING IN FROM THE NORTHWEST THIS FRONT WILL MAKE FAIRLY
SLOW PROGRESS SOUTHWARD EARLY THURSDAY. THIS MEANS THAT THE NORTHERN
AND SOUTHERN ZONES WILL SPEND SEVERAL HOURS SPLIT BETWEEN THE NE AND
THE SW WINDS ON EITHER SIDE OF THE BOUNDARY. FURTHER COMPLICATING
MATTERS IS THAT THERE IS UNCERTAINTY REGARDING THE TRACK AND
STRENGTH OF A LOW EXPECTED TO MOVE WEST TO EAST ACROSS THE REGION.
TOUGH TO SAY WHETHER OR NOT SEAS BUILD INTO ADVISORY REALM AT ANY
TIME DURING THE PERIOD BUT AN EXTENDED STRETCH OF SCEC HEADLINES
APPEARS LIKELY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...STRONG NORTHEAST FLOW OVER THE WATERS FRI/FRI
NIGHT WITH GRADIENT PINCHED BETWEEN EXITING SURFACE LOW AND HIGH
BUILDING DOWN THE COAST. HEADLINES WILL LIKELY BE REQUIRED FRI FOR
ALL WATERS. GRADIENT STARTS TO RELAX SAT BUT HEADLINES WILL LIKELY
CARRY OVER INTO THE EVENING BEFORE SEAS DROP BELOW SCA THRESHOLDS.
SURFACE RIDGE AXIS REMAINS WEST OF THE WATERS EARLY SUN...WITH
NORTHEAST FLOW CONTINUING OVER THE WATERS. HOWEVER...SPEEDS WILL BE
MUCH LESS THAN FRI/SAT...10 TO 15 KT INSTEAD OF 20 TO 25 KT.
APPROACHING COLD FRONT LATE IN THE PERIOD WILL RESULT IN WINDS
BECOMING SOUTHERLY SUN AFTERNOON...THOUGH GRADIENT REMAINS WEAK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HOEHLER
SHORT TERM...BACON
LONG TERM...LEBO
AVIATION...LOEWENTHAL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
208 AM EDT WED APR 4 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE THROUGH THE REGION TONIGHT...WITH
THUNDERSTORMS DEVELOPING UNTIL TOMORROW MORNING. HIGH PRESSURE
WILL GRADUALLY MOVE IN FROM THE NORTH THROUGH THE END OF THE
WEEK...WITH GRADUALLY COOLING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AIRMASS ACROSS OUR AREA REMAINS JUST SLIGHTLY UNSTABLE AND THIS IS
GENERALLY ALOFT AS BOUNDARY LAYER HAS COOLED/DRIED IN THE WAKE OF
EARLIER OUTFLOW BOUNDARY. A LINE OF SHOWERS AND THUNDERSTORMS IS
CONTINUING ALONG THE COLD FRONT BACK ACROSS CENTRAL ILLINOIS INTO
NORTHERN INDIANA...BUT SO FAR THESE HAVE HAD A TOUGH TIME
PROGRESSING EASTWARD. THE LATEST HRRR IS SHOWING THIS PCPN PUSHING
EAST INTO OUR NORTHERN AREAS THROUGH 06Z...BUT GIVEN TRENDS AND
MORE STABLE AIRMASS ACROSS OUR AREA...NOT SURE IF THAT WILL PAN
OUT. AS LOW OVER MISSOURI PUSHES EAST THROUGH THE OVERNIGHT
HOURS...WE SHOULD BEGIN TO MOISTEN UP A BIT MORE AND PERHAPS
DESTABILIZE ALOFT A LITTLE BETTER. WILL MAKE SOME DOWNWARD
ADJUSTMENTS TO POPS IN THE NEAR TERM AND BRING BETTER POPS IN FROM
THE SOUTHWEST LATER TONIGHT. SEVER THREAT SEEMS TO BE RATHER LOW
GIVEN BOTH WEAK SHEAR PROFILES AND WEAK INSTABILITY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
THE SOUTHERN HALF OF THE CWA WILL START THE DAY WEDNESDAY IN A
FAVORABLE CONVERGENT AREA FOR CONTINUED SHOWER AND THUNDERSTORM
DEVELOPMENT. THIS WILL DIMINISH AS THE SURFACE FRONT PUSHES SOUTH
OF THE FORECAST AREA DURING THE AFTERNOON...BEGINNING A PATTERN OF
NORTH WINDS AND COLD ADVECTION THAT WILL GO THROUGH THE END OF THE
WEEK. MOISTURE WILL REMAIN JUST SOUTH OF THE FORECAST AREA...AND
MAY ACTUALLY EDGE NORTH ENOUGH TO PRODUCE SOME PRECIPITATION IN
THE FAR SOUTH ON THURSDAY. THIS WILL BE POSSIBLE AS A WEAKENING
CLOSED UPPER LOW MOVES EAST INTO THE TENNESSEE VALLEY.
OVERALL...HOWEVER...A DRIER AND COOLER AIR MASS WILL BE THE RESULT
OF THIS SHIFT IN THE WEATHER PATTERN.
TEMPERATURES...THUS...SHOULD COOL THROUGH THE FORECAST PERIOD.
THIS WILL RESULT IN MIN TEMPERATURES GETTING VERY CLOSE TO
FREEZING ON THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
BEGINNING OF PERIOD WILL BE MARKED BY AN AMPLIFIED UPPER LEVEL FLOW
PATTERN. UPPER LOW THAT HAD BEEN TREKKING ACROSS THE MID SOUTH WILL
BE ABSORBED INTO AN EAST COAST TROUGH. SHARP RIDGING OVER THE PLAINS
WILL PLACE THE LOCAL AREA IN NORTHERLY FLOW ALOFT. AT THE SFC...HIGH
PRESSURE WILL BUILD SOUTHWARD FROM ONTARIO INTO THE GREAT LAKES.
THIS WILL LEAD TO DRY AND SEASONABLE CONDITIONS FOR FRIDAY. ON
FRIDAY NIGHT...THE SFC HIGH WILL BUILD OVERHEAD...LEADING TO CLEAR
SKIES AND LIGHT WINDS. FROST WILL BE A CONCERN OVER MUCH OF THE CWA
EXCEPT PERHAPS NORTHERN KY...AND THE TYPICAL COOLER LOCALES EAST OF
COLUMBUS MAY APPROACH FREEZING (THESE TEMPERATURES REPRESENT A
DOWNWARD ADJUSTMENT FROM THE PREVIOUS FORECAST). AS THE HIGH SLIDES
EAST OF THE AREA ON SATURDAY...WINDS WILL BECOME SOUTHERLY AND
PROMOTE TEMPERATURES TO RISE A LITTLE ABOVE NORMAL.
THE NEXT SHORT WAVE TROUGH TO APPROACH FROM THE ROCKIES WILL MAINLY
SERVE TO SQUASH THE UPPER RIDGE...WITH MOST OF THE ENERGY REMAINING
NORTH OF THE AREA. A SFC LOW WILL TRACK WELL NORTH INTO
CANADA...WITH A TRAILING COLD FRONT CROSSING THE AREA ON SUNDAY.
MODELS DISAGREE A LITTLE ON TIMING...BUT APPEARS TO BE MAINLY A
DAYTIME EVENT...SO DELAYED POPS A LITTLE FROM PREVIOUS FORECAST. IN
WESTERLY FLOW THROUGHOUT THE ATMOSPHERE...THE FRONT WILL BE MOISTURE
STARVED...SO MAINTAINED THE LOW CHANCE POPS. INSTBY WILL BE WEAK BUT
PRESENT (MORESO SOUTH)...SO KEPT THUNDER MENTION. AIRMASS CHANGE
BEHIND THE FRONT WILL BE MINIMAL AS WEAK SFC RIDING EXTENDS INTO THE
AREA BY SUNDAY NIGHT INTO EARLY MONDAY...WITH TEMPERATURES REMAINING
SLIGHTLY ABOVE NORMAL.
AS UPPER LEVEL GYRE FORMS OVER EASTERN CANADA...ANOTHER SHORTWAVE
TROUGH WILL ROTATE DOWN THROUGH THE AREA LATE MONDAY INTO TUESDAY.
THIS SYSTEMS WILL BE MOISTURE STARVED AS WELL...SO LIMITED FORECAST
TO CHANCE POPS. LEFT THUNDER MENTION OUT WITH LIMITED INSTBY AND
HIGHER THETA-E SUPPRESSED FAR TO OUR SOUTH. WHILE MODELS DIFFER WITH
TIMING AND EXACT FEATURES...THEY AGREE ON THE MORE SUBSTANTIAL
EFFECT FROM THIS SYSTEM...WHICH WILL BE THE COLDER AIR IT PULLS
SOUTHWARD INTO THE AREA. FORECAST HIGH TEMPERATURES ON TUESDAY ARE
ABOUT 10 DEGREES BELOW NORMAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
COLD FRONT WHICH IS ORIENTED W-E FROM NEAR KSTL TO JUST SOUTH OF
KIND TO NEAR KDAY TO SAG SLOWLY SOUTH THRU THIS MORNING. SCATTERED
THUNDERSTORMS WILL DEVELOP THIS MORNING IN THE MARGINALLY UNSTBL
AIR AHD OF A WAVE OF LOW PRESSURE TRACKING ALONG THIS FRONTAL
BOUNDARY. WITH THE SOUTHWARD PUSH OF THE FRONT...EXPECT THE BEST
CHANCE FOR THUNDERSTORMS TO BE ACROSS KCVG/KLUK. WILL THEREFORE
MENTION PREVAILING PRECIP AT KCVG/KLUK AND TEMPO AT KDAY AND LIMIT
MENTION TO VCTS AT KCMH/KLCK. PCPN SHOULD TAPER OFF FROM NORTH TO
SOUTH THROUGH LATE MORNING. GOOD CAA IN THE WAKE OF THE FRONT
MAY LEAD TO A PERIOD OF MVFR CIGS...BEFORE DRIER AIR IS ABLE TO
WORK IN FROM THE NORTH ALLOWING CONDITIONS TO BECOME VFR.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...JGL
SHORT TERM...HATZOS
LONG TERM...SNYDER
AVIATION...AR
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
637 AM CDT WED APR 4 2012
.AVIATION...
CONDITIONS SHOULD REMAIN LARGELY VFR FOR ALL TAF SITES. THE
EXCEPTION MAY BE KHOT AND KM89 FOR A BRIEF PERIOD THIS
MORNING...AND ALSO ANY TAF SITES AFFECTED BY SHOWERS LATER THIS
MORNING. DEWPOINT DEPRESSIONS ARE VERY SMALL AT THOSE SITES AND
KHOT IS SHOWING FEW-SCT003 BASES. THEY ARE RIGHT ON THE CUSP OF
DEVELOPING SOME FOG OR LOW CLOUDS SO HAVE THROWN A TEMPO FOR 4SM
AND SCT003 AT THOSE TWO TERMINALS. OTHERWISE...HAVE TRENDED
TOWARDS RUC GUIDANCE WHICH SHOWS SHOWERS DEVELOPING FROM ROUGHLY
KFYV DOWN TO KELD BEFORE 14Z...THEN SHIFTING EAST OF ALL TERMINALS
BY 18Z OR SO. NOT TERRIBLY CONFIDENT IN HOW MUCH REDEVELOPMENT OF
SHOWER ACTIVITY WE ARE GOING TO SEE TODAY SO ONLY INCLUDED MENTION
OF VCSH AT TERMINALS FOR A SHORT PERIOD THIS MORNING. WINDS WILL
GRADUALLY TURN WSW THROUGH THE DAY AS THE FRONT PASSES THROUGH.
LOOKS LIKE THERE SHOULD BE ENOUGH DRY AIR TO PRECLUDED FOG OR LOW
CLOUDS TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT WED APR 4 2012/
SHORT RANGE...TODAY THROUGH SATURDAY NIGHT
MODELS REMAIN IN BASICALLY GOOD AGREEMENT THIS MORNING DEPICTING A
SLOW MOVING UPPER LOW AND ASSOCIATED FRONTAL BOUNDARY MOVING ACROSS
THE FORECAST AREA. GFS/ECMWF COMBO PREFERRED THIS MORNING WITH NAM
SOLUTION INITIATING POORLY AND AS SUCH DISCOUNTED.
CLOSED OFF UPPER LOW OVER THE TEXAS/OKLAHOMA PANHANDLES SHOWING UP
CLEARLY ON MOISTURE CHANNEL IMAGERY THIS MORNING. SYSTEM REMAINS CUT
OFF FROM THE PREVAILING FLOW AND WILL DRIFT SLOWLY EASTWARD ACROSS
THE NORTHERN PART OF THE STATE OVER THE NEXT DAY OR SO...AND NOT
EXPECTED TO CLEAR THE STATE UNTIL THURSDAY AFTERNOON. ASSOCIATED
SURFACE BOUNDARY CURRENTLY OVER EASTERN OKLAHOMA AND ALSO EXPECTED
TO TAKE ITS TIME GETTING THROUGH THE STATE...LIKELY NOT CLEARING THE
MISSISSIPPI RIVER UNTIL LATE WEDNESDAY NIGHT/EARLY THURSDAY MORNING.
UPPER IMPULSE MOVING THROUGH THE REGION THIS MORNING CONTINUES TO
PRODUCE SCATTERED SHOWERS BUT OVERALL AREA CONTINUES TO DECREASE IN
AREAL COVERAGE. STRONGEST CONVECTION REMAINS TO THE SOUTH OF THE
FORECAST AREA BUT ISOLATED THUNDER CANNOT BE RULED OUT THIS MORNING
ESPECIALLY ACROSS THE SOUTHERN COUNTIES.
NEXT IMPULSE WILL MOVE THROUGH THE BASE OF THE UPPER LOW DURING THE
AFTERNOON. JET DYNAMICS ASSOCIATED WITH THE WAVE WILL LIKELY LEAD TO
ADDITIONAL CONVECTIVE DEVELOPMENT ALONG AND TO THE EAST OF THE
AFOREMENTIONED SURFACE BOUNDARY WHICH SHOULD LIKELY BE OVER THE
EASTERN THIRD OF THE FORECAST AREA. CAN NOT RULE OUT SOME STRONGER
STORMS OVER THIS AREA. PRECIPITATION CHANCES WILL BE LESS FURTHER TO
THE EAST AS DRIER AIR MOVES IN.
UPPER LOW MOVES ACROSS THE NORTH TONIGHT AND THURSDAY WITH ANOTHER
IMPULSE ROTATING THROUGH ITS BASE. THE RESULT WILL BE ANOTHER CHANCE
OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS WITH THE BEST CHANCES
OVER THE NORTH CLOSER TO THE UPPER LOW. SYSTEM FINALLY CLEARS THE
STATE BY THURSDAY EVENING WITH HIGH PRESSURE BUILDING IN BEHIND THE
DEPARTING LOW WITH DRY CONDITIONS EXPECTED FRIDAY.
NEXT COLD FRONT WILL APPROACH THE STATE DURING THE DAY SATURDAY. GFS
KEEPS AREA DRY BUT ECMWF DOES PAINT A LITTLE QPF OVER THE NORTHWEST
ZONES LATE IN THE DAY. OVERALL SPEED OF THE FRONT A LITTLE SLOWER
AND WILL TRIM BACK POPS TO THE NORTHWEST SATURDAY AND AREA WIDE
SATURDAY NIGHT AS BOUNDARY WILL BE BISECTING THE STATE FROM
NORTHEAST TO SOUTHWEST BY THE END OF THE PERIOD. REGARDLESS...POPS
WILL ONLY BE SLIGHT CHANCE TO LOW END CHANCE AS SYSTEM NOT VERY
IMPRESSIVE.
TEMPERATURES WILL BE TRICKY TODAY DEPENDING ON WHERE THE FRONT ENDS
UP ALONG WITH PRECIP AND CLOUD COVER COMING INTO PLAY. WARMEST DAY
STILL LOOKS TO BE TODAY WITH TEMPERATURES RETURNING TO NEAR NORMAL
FOR THE REMAINDER OF THE PERIOD. MAV/MEX NUMBERS LOOK REASONABLE AND
ARE GENERALLY ACCEPTED.
LONG TERM...SUNDAY THROUGH TUESDAY...
A COLD FRONT WILL SWEEP THROUGH THE STATE ON SUNDAY AS AN UPPER
RIDGE BUILDS OVER THE HIGH PLAINS AND A TROUGH OVER THE EASTERN
CONUS. REALLY DO NOT EXPECT MUCH IN THE WAY OF PRECIP AS RETURN FLOW
WILL BE WEAK OR NON-EXISTENT IN THE DAYS LEADING UP TO SUN...AND
UPPER SUPPORT SHOULD BE WELL REMOVED TO THE NORTH. THE COLD FRONT
WILL STALL OUT TO THE SOUTH AND WEST OF THE STATE LATER IN THE
PERIOD. PREVIOUS SHIFTS HAD SOME SLIGHT CHANCE POPS...MAINLY IN THE
SOUTHWEST...ON MONDAY. WILL LEAVE THIS AS-IS DUE TO SHORTWAVE ENERGY
ROTATING THROUGH EITHER NEAR ARKANSAS...OR OVERHEAD DEPENDING ON
WHICH MODEL YOU BELIEVE. DID REMOVE PRECIP MENTION ON MONDAY NIGHT
THOUGH AS LOSS OF DAYTIME HEATING AND WHAT MARGINAL UPPER SUPPORT
WAS PRESENT SHOULD MEAN ANY SHOWER WOULD DIE A QUICK DEATH. AS FOR
TEMPERATURES...THEY WILL BE MUCH CLOSER TO NORMAL VALUES VERSUS WHAT
HAS BEEN SEEN LATELY. HIGHS FROM THE LOW 70S NORTH TO THE MID/UPPER
70S IN THE SOUTH WILL BE THE NORM. LOWS WILL BE IN THE LOW TO MID
50S INITIALLY...PERHAPS DIPPING INTO THE UPPER 30S TO LOW 40S IN THE
NORTH BY MONDAY/TUESDAY NIGHTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 79 55 73 48 / 50 30 40 10
CAMDEN AR 81 54 78 53 / 40 20 20 10
HARRISON AR 76 52 72 46 / 40 30 40 10
HOT SPRINGS AR 79 54 75 53 / 40 20 30 10
LITTLE ROCK AR 80 55 76 53 / 40 30 30 10
MONTICELLO AR 82 56 79 54 / 50 20 20 10
MOUNT IDA AR 78 53 75 52 / 30 20 30 10
MOUNTAIN HOME AR 77 53 72 47 / 40 40 40 10
NEWPORT AR 79 55 74 49 / 50 40 40 10
PINE BLUFF AR 81 56 78 54 / 50 30 30 10
RUSSELLVILLE AR 78 53 74 50 / 40 30 30 10
SEARCY AR 80 55 75 50 / 50 30 30 10
STUTTGART AR 81 56 77 53 / 50 30 30 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...64
AREA FORECAST DISCUSSION
NWS MIAMI FL
1005 AM EDT WED APR 4 2012
.UPDATE...THE SHORT TERM FORECAST REMAINS ON TRACK WITH NO
APPRECIABLE CHANGES NEEDED. THE 12Z MFL SOUNDING CONTINUES TO
SHOW CONSIDERABLE DRY AIR IN THE MID AND UPPER LEVELS. HOWEVER,
WITH SIGNIFICANT DAYTIME HEATING AND JUST ENOUGH MOISTURE, A FEW
ISOLATED SHOWERS OR THUNDERSTORMS COULD FORM THIS AFTERNOON,
ESPECIALLY AS THE SEA BREEZE MOVES INLAND. TEMPERATURES WILL
REMAIN ABOVE NORMAL, PEAKING IN THE UPPER 80S TO LOWER 90S AND
APPROACHING RECORD HIGHS AT A FEW LOCATIONS.
&&
.PREV DISCUSSION... /ISSUED 732 AM EDT WED APR 4 2012/
AVIATION...
VFR CONDITIONS TO PREVAIL AT ALL SITES THROUGH THE PERIOD.
SOUTHERLY FLOW WILL PREVAIL THROUGH THE AFTERNOON HOURS AROUND
10-12 KTS AT ALL SITES EXCEPT KAPF WHERE A WEST TO SOUTHWEST SEA
BREEZE SHOULD SET UP AGAIN THIS AFTERNOON. LIGHT WINDS ARE
EXPECTED TONIGHT. PATCHY FOG MAY BE POSSIBLE THURSDAY
MORNING...BUT PROBABILITY IS TOO LOW TO MENTION AT THIS TIME.
PREV DISCUSSION... /ISSUED 448 AM EDT WED APR 4 2012/
.FEW STRONG THUNDERSTORMS POSSIBLE THIS AFTERNOON, THU AFTERNOON, AND
FRIDAY WITH LOW PROBABILITIES OF SEVERE...
.HOT THROUGH FRIDAY, THEN COOLER AND DRIER THIS WEEKEND-NEXT WEEK...
DISCUSSION...WATER VAPOR IMAGERY SHOWS A MID/UPPER LEVEL LOW
SPINNING OVER THE TEXAS/OKLAHOMA PANHANDLE REGION WITH WEST
SOUTHWEST FLOW PREDOMINATING ACROSS THE GULF AND ACROSS FLORIDA.
BOTH GFS AND ECMWF SHOW THIS UPPER LOW MOVING ACROSS THIS MID
SOUTH ON THU...THEN OPENING UP AND MERGING WITH A TROUGH WHICH
WILL AMPLIFY ACROSS NEW ENGLAND AND THE MID ATLANTIC STATES ON
FRIDAY. LOW PRESSURE WILL DEVELOP NEAR THE CAROLINA COAST MOVING
INTO THE ATLANTIC FRIDAY WITH A TRAILING COLD FRONT SWEEPING
ACROSS SOUTH FLORIDA FRIDAY EVENING.
AHEAD OF THIS FRONT, THE AIRMASS WILL CONTINUE FAIRLY DRY WITH
FORECAST SOUNDINGS SHOWING PWAT VALUES OF 1-1.2 INCHES TODAY
RISING TO 1.3-1.5 LATE THU-FRI. IT WILL BE UNSTABLE EACH AFTERNOON
THROUGH FRIDAY. GOES SOUNDER DATA SHOWS H5 TEMPS NOW IN THE -12 TO
-13C RANGE OVER SOUTH FLORIDA. FCST SOUNDINGS SHOW EVEN SLIGHT
COOLING TO -14C BY EVENING WITH LI`S FALLING TO AROUND -7C AND
CAPE NEARING 2000 J/KG LATE IN THE DAY. GIVEN LACK OF
MOISTURE...ONLY HAVE SLIGHT CHC POPS INTERIOR-EAST. IT`S POSSIBLE
THAT NOTHING DEVELOPS THIS AFTERNOON...BUT THERE MAY BE JUST
ENOUGH MOISTURE TO ALLOW A FEW TSTORMS TO DEVELOP. HRRR INDEED
DOES SHOW ISOLATED DEVELOPMENT INTERIOR/EAST COAST THIS AFTERNOON.
GIVEN THE STRONG HEATING TODAY AND COLD AIR ALOFT, ONE OR TWO
PULSE STRONG TSTORMS WILL BE POSSIBLE INTERIOR-EAST, CAPABLE OF
PRODUCING GUSTY WINDS UP TO 50 MPH ALONG WITH HAIL AND FREQUENT
LIGHTNING STRIKES.
AS MOISTURE INCREASES A TAD THURSDAY AFTERNOON, THE RISK OF TSTORMS
INCREASES. SW STEERING FLOW WILL LEAD TO CONVERGENCE ACROSS THE
EAST COAST METRO AREAS, SO SCATTERED TSTORMS ARE EXPECTED EAST
COAST METRO WITH A SLIGHT CHANCE ELSEWHERE. THEN ON FRIDAY THERE
WILL BE A CHANCE OF THUNDERSTORMS AREA WIDE ALONG/AHEAD OF THE
COLD FRONT. STABILITY INDICES SHOW THAT IT WILL CONTINUE TO BE
QUIET UNSTABLE, PARTICULARLY ON THURSDAY AFTERNOON. HOWEVER, THE
BETTER DYNAMICS WILL BE ON FRIDAY. STRONG TSTORMS WILL BE POSSIBLE
EACH DAY WITH LOW PROBABILITIES OF SEVERE. CURRENT ASSESSMENT
SUGGESTS THAT THE GREATEST POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS
IS THURSDAY AFTERNOON EAST COAST METRO...DUE TO WEAKER FLOW ON THIS
DAY, BETTER SURFACE CONVERGENCE AND HIGH INSTABILITY.
HOT DAYS WILL PREVAIL THROUGH FRIDAY WITH HIGHS TOPPING 90 MOST
INLAND LOCALES AND NEAR 90 EAST. CONSENSUS GUIDANCE WAS TOO COOL
FOR MAXES NEXT FEW DAYS...SO FOLLOWED A NAM12-GFS BLEND. THE COLD
FRONT WILL MOVE ACROSS SOUTH FL FRIDAY EVENING, BRINGING IN A COOL
AIRMASS FOR APRIL STANDARDS WITH HIGHS IN THE UPPER 70S TO LOWER
80S AND DEWPOINTS FALLING INTO THE 50S THIS WEEKEND. NIGHTTIME
LOWS WILL FALL INTO THE 50S INTERIOR AND 60S COASTS. THIS COOLER
TREND WILL CONTINUE NEXT WEEK...WITH BOTH GFS/ECMWF SHOWING A RE-
ENFORCING SHOT OF COOLER AIR FROM THE NORTH MID WEEK. THIS WILL
KEEP TEMPS/HUMIDITY IN CHECK THROUGH NEXT WEEK WITH COMFORTABLE
WEATHER PREVAILING AND DRY WEATHER EXPECTED.
MARINE...NO CONCERNS IN THE NEAR TERM, BUT WINDS/SEAS WILL
INCREASE, ESPECIALLY IN THE GULF STREAM BEHIND THE COLD FRONT FRI
EVENING AS WINDS BECOME NE AND INCREASE.
FIRE WEATHER...RELATIVE HUMIDITIES FELL INTO THE MID 20S TO LOWER
30S OVER A LARGE PORTION OF INTERIOR SOUTH FL YESTERDAY. TODAY,
LOW RH`S OF BELOW 35 PERCENT FOR 4 HR OR MORE ARE FORECAST FOR THE
LAKE OKEECHOBEE REGION AND INLAND COLLIER AND INLAND BROWARD
COUNTIES...SO WILL BE ISSUING A FIRE DANGER STMT FOR THESE
LOCALES. MOISTURE WILL INCREASE ON THU-FRI WITH MODIFYING RH`S
THEN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 89 72 / 20 10 40 40
FORT LAUDERDALE 88 72 89 73 / 10 10 30 30
MIAMI 88 72 89 73 / 10 10 30 30
NAPLES 85 69 85 71 / - 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
UPDATE...14/MJB
AREA FORECAST DISCUSSION
NWS MIAMI FL
732 AM EDT WED APR 4 2012
.AVIATION...
VFR CONDITIONS TO PREVAIL AT ALL SITES THROUGH THE PERIOD.
SOUTHERLY FLOW WILL PREVAIL THROUGH THE AFTERNOON HOURS AROUND
10-12 KTS AT ALL SITES EXCEPT KAPF WHERE A WEST TO SOUTHWEST SEA
BREEZE SHOULD SET UP AGAIN THIS AFTERNOON. LIGHT WINDS ARE
EXPECTED TONIGHT. PATCHY FOG MAY BE POSSIBLE THURSDAY
MORNING...BUT PROBABILITY IS TOO LOW TO MENTION AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 448 AM EDT WED APR 4 2012/
..FEW STRONG THUNDERSTORMS POSSIBLE THIS AFTERNOON, THU AFTERNOON, AND
FRIDAY WITH LOW PROBABILITIES OF SEVERE...
..HOT THROUGH FRIDAY, THEN COOLER AND DRIER THIS WEEKEND-NEXT WEEK...
DISCUSSION...WATER VAPOR IMAGERY SHOWS A MID/UPPER LEVEL LOW
SPINNING OVER THE TEXAS/OKLAHOMA PANHANDLE REGION WITH WEST
SOUTHWEST FLOW PREDOMINATING ACROSS THE GULF AND ACROSS FLORIDA.
BOTH GFS AND ECMWF SHOW THIS UPPER LOW MOVING ACROSS THIS MID
SOUTH ON THU...THEN OPENING UP AND MERGING WITH A TROUGH WHICH
WILL AMPLIFY ACROSS NEW ENGLAND AND THE MID ATLANTIC STATES ON
FRIDAY. LOW PRESSURE WILL DEVELOP NEAR THE CAROLINA COAST MOVING
INTO THE ATLANTIC FRIDAY WITH A TRAILING COLD FRONT SWEEPING
ACROSS SOUTH FLORIDA FRIDAY EVENING.
AHEAD OF THIS FRONT, THE AIRMASS WILL CONTINUE FAIRLY DRY WITH
FORECAST SOUNDINGS SHOWING PWAT VALUES OF 1-1.2 INCHES TODAY
RISING TO 1.3-1.5 LATE THU-FRI. IT WILL BE UNSTABLE EACH AFTERNOON
THROUGH FRIDAY. GOES SOUNDER DATA SHOWS H5 TEMPS NOW IN THE -12 TO
-13C RANGE OVER SOUTH FLORIDA. FCST SOUNDINGS SHOW EVEN SLIGHT
COOLING TO -14C BY EVENING WITH LI`S FALLING TO AROUND -7C AND
CAPE NEARING 2000 J/KG LATE IN THE DAY. GIVEN LACK OF
MOISTURE...ONLY HAVE SLIGHT CHC POPS INTERIOR-EAST. IT`S POSSIBLE
THAT NOTHING DEVELOPS THIS AFTERNOON...BUT THERE MAY BE JUST
ENOUGH MOISTURE TO ALLOW A FEW TSTORMS TO DEVELOP. HRRR INDEED
DOES SHOW ISOLATED DEVELOPMENT INTERIOR/EAST COAST THIS AFTERNOON.
GIVEN THE STRONG HEATING TODAY AND COLD AIR ALOFT, ONE OR TWO
PULSE STRONG TSTORMS WILL BE POSSIBLE INTERIOR-EAST, CAPABLE OF
PRODUCING GUSTY WINDS UP TO 50 MPH ALONG WITH HAIL AND FREQUENT
LIGHTNING STRIKES.
AS MOISTURE INCREASES A TAD THURSDAY AFTERNOON, THE RISK OF TSTORMS
INCREASES. SW STEERING FLOW WILL LEAD TO CONVERGENCE ACROSS THE
EAST COAST METRO AREAS, SO SCATTERED TSTORMS ARE EXPECTED EAST
COAST METRO WITH A SLIGHT CHANCE ELSEWHERE. THEN ON FRIDAY THERE
WILL BE A CHANCE OF THUNDERSTORMS AREA WIDE ALONG/AHEAD OF THE
COLD FRONT. STABILITY INDICES SHOW THAT IT WILL CONTINUE TO BE
QUIET UNSTABLE, PARTICULARLY ON THURSDAY AFTERNOON. HOWEVER, THE
BETTER DYNAMICS WILL BE ON FRIDAY. STRONG TSTORMS WILL BE POSSIBLE
EACH DAY WITH LOW PROBABILITIES OF SEVERE. CURRENT ASSESSMENT
SUGGESTS THAT THE GREATEST POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS
IS THURSDAY AFTERNOON EAST COAST METRO...DUE TO WEAKER FLOW ON THIS
DAY, BETTER SURFACE CONVERGENCE AND HIGH INSTABILITY.
HOT DAYS WILL PREVAIL THROUGH FRIDAY WITH HIGHS TOPPING 90 MOST
INLAND LOCALES AND NEAR 90 EAST. CONSENSUS GUIDANCE WAS TOO COOL
FOR MAXES NEXT FEW DAYS...SO FOLLOWED A NAM12-GFS BLEND. THE COLD
FRONT WILL MOVE ACROSS SOUTH FL FRIDAY EVENING, BRINGING IN A COOL
AIRMASS FOR APRIL STANDARDS WITH HIGHS IN THE UPPER 70S TO LOWER
80S AND DEWPOINTS FALLING INTO THE 50S THIS WEEKEND. NIGHTTIME
LOWS WILL FALL INTO THE 50S INTERIOR AND 60S COASTS. THIS COOLER
TREND WILL CONTINUE NEXT WEEK...WITH BOTH GFS/ECMWF SHOWING A RE-
ENFORCING SHOT OF COOLER AIR FROM THE NORTH MID WEEK. THIS WILL
KEEP TEMPS/HUMIDITY IN CHECK THROUGH NEXT WEEK WITH COMFORTABLE
WEATHER PREVAILING AND DRY WEATHER EXPECTED.
MARINE...NO CONCERNS IN THE NEAR TERM, BUT WINDS/SEAS WILL
INCREASE, ESPECIALLY IN THE GULF STREAM BEHIND THE COLD FRONT FRI
EVENING AS WINDS BECOME NE AND INCREASE.
FIRE WEATHER...RELATIVE HUMIDITIES FELL INTO THE MID 20S TO LOWER
30S OVER A LARGE PORTION OF INTERIOR SOUTH FL YESTERDAY. TODAY,
LOW RH`S OF BELOW 35 PERCENT FOR 4 HR OR MORE ARE FORECAST FOR THE
LAKE OKEECHOBEE REGION AND INLAND COLLIER AND INLAND BROWARD
COUNTIES...SO WILL BE ISSUING A FIRE DANGER STMT FOR THESE
LOCALES. MOISTURE WILL INCREASE ON THU-FRI WITH MODIFYING RH`S
THEN.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 71 89 72 / 20 10 40 40
FORT LAUDERDALE 88 72 89 73 / 10 10 30 30
MIAMI 88 72 89 73 / 10 10 30 30
NAPLES 85 69 85 71 / - 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...14/MJB
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION...updated for aviation discussion
NWS TALLAHASSEE FL
532 AM EDT Wed Apr 4 2012
...SEVERE STORMS ARE POSSIBLE TODAY AND LIKELY ON THURSDAY...
...COOLER TEMPERATURES ON TAP BY THE WEEKEND...
.SYNOPSIS...
Rainfall assocd with Tuesday`s MVC has effectively dissipated.
However we are keeping an eye on outflow generated convection
moving east across coast wrn panhandle. Expect some fog to linger
this morning especially west of the Apalachicola River but advancing
clouds decks limiting dense fog witnessed previous two nights.
AT UPPER LEVELS...
The large scale split flow longwave pattern commences rather
amplified with well established blocking pattern. This is
highlighted in nrn stream by ridge over Nrn Plains to Cntrl
Canada anchored by troughs across extreme Ern PAC/West Coast and
NE states. In Srn stream, ridge over Srn CA/Desert SW, trough over
Srn Plains with very slow moving cutoff low Srn High Plains then
weak ridging ewd to Ern seaboard with axis from NE SEWD to Srn FL.
It is the low that will be our next major weather maker on Thurs.
During the rest of the period, Low is expected to slowly move to
Srn MO by sunrise Thurs then across Cntrl Gulf Region by aftn and
around base of Ern trough into Thurs night then out into Atlc early
Fri increasingly flattening Ern ridge. A series of shortwaves
will eject Ewd from low sparking convection. Today, one currently
across OH Valley will move SEWD towards KY reaching mid-Atlc late
tonight while a second impulse will move across Srn AL/GA later
today.
AT LOWER LEVELS...
Main features are high off Cntrl FL coast with ridge WSW across
Cntrl FL and Gulf of Mex. 1005mb low over ern OK/KS border with warm
front ENE to mid-Atlc states and cold front swd thru ern OK/ern TX
and into Gulf.
During the rest of the period, under influence of upper low, surface
reflection will strengthen and move east thru AL by Thurs aftn
dragging cold front SEWD. This low will track slowly into the
Carolinas on Fri before moving offshore. WSW-ENE oriented front
will move from LA/MS early Thurs morning to across SE AL/SW GA/FL
Panhandle during the afternoon and will exit our area Thurs night
into early Fri. Ahead of these systems, with substantial low level
moisture and no capping, the airmass is expected to be warm and
unstable with dewpoints in the mid 60s and a wide area of SBCAPE
values between 1500-2000 j/kg. Mid level lapse rates are also
forecast to be fairly steep around 6.5-7.0 C/km. Deep layer shear
values with generally WLY low level flow from the GFS and NAM are
forecast to be between 30 and 40 knots with 0-1 km shear around 20
knots. Guidance suggests a 60 kt H5 speed max across srn AL by
sundown. Although widespread severe weather is not likely,
instability indices point to strong to severe storms on Thurs and
Thurs evening. In wake of front, large surface high builds ESE from
MS Valley to SE Coast. Another shortwave diving into the Ern trough
will bring a reinforcing shot of colder and drier air that
overspreads the region thru the weekend and beyond.
.SHORT TERM...(Today through Friday)...
TODAY...Overnight radar shows apparent MCS over MS some of which
will work its way EWD later today. Also various outflow boundaries
linger from yesterday`s storms and could serve as focus for storms
today. One noted across W/Cntrl AL during predawn hours will move
east into worked over area and weaken but still may help ignite
storms later today. Also weak shortwave is expected to move across
mainly Srn GA later during time of max heating when RUC sounding
PWATs around 1.4 inches and capes around 2800 j/kg. All this could
spark another bout of showers and thunderstorms especially over GA
counties. 40-10% NE-SW POP gradient. Some storms may again be strong
to isold severe with locally heavy rain, especially if sun breaks
out to enhance diurnal heating allowing aftn temps to rise. However
will not use enhanced wording in grids as local severe wx tool with
only 2% chance and local CAM with essentially zero with CIN -7 to
-10 especially over FL.
TONIGHT...Afternoon convection will persist past sundown. 40-10%
NE-SE POP gradient. Local severe wx tool with up to 7% chance of
severe wx mainly wrn counties.
THURSDAY...70-60% N-S POP gradient. Guidance indicates that ample
convection will exist across wrn third of CWA early focused by
warm advection along surface boundary. Some will likely be at
least isold severe. Since wind fields will be largely
unidirectional, focus will be on bowing lines with damaging wind.
However, temperatures should remain sufficiently cool for large
hail. This overlays well with local severe wx tool with 25-5% SW-
NE gradient of chances of severe wx in morning. Later in the day,
activity will switch ewd but how strong this convection will be
will depend in part on how much instability remains and impact of
clouds on downstream insolation. Still, combination of approaching
upper low, next shortwave, strengthening surface low and cold
front should generate organized storms moving from MS into AL then
GA in aftn with a continued threat of damaging winds and large
hail. Local severe wx tool with 15-20% chance of severe wx. SPC
has placed Wrn 2/3rds of CWA in slight risk of severe tstms.
THURSDAY NIGHT...As front moves SEWD across CWA, chances for
severe wx diminish. 40-60% NE-SE pop gradient. local severe tool
reflects this with 6-20% NW-SE gradient 00z-06z and 0-12% chance
06z-12z.
FRIDAY...20-30% NW-SE mainly morning pop gradient. Lingering
convection across ern third of local area will exit east of I-75
after midday. Expect gusty offshore winds.
&&
.LONG TERM...
(Saturday through next Wednesday) Fair weather and a return to more
seasonal temperatures are likely this weekend behind Friday`s cold
front passage. Highs will be in the mid to upper 70s and lows in the
40s. With lower humidity, it will feel much more comfortable than
the past several days. The large scale 500 mb pattern will
transition to a fairly deep trough over the eastern CONUS early to
mid week, though the GFS forecasts a deeper, less progressive trough
than the ECMWF. The next chance for rain will be late Monday and
early Tuesday as a cold front moves south through the region, though
deep layer moisture and instability are not that impressive. The GFS
is much cooler than the ECMWF behind this front, as it forecasts the
850 mb freezing line to reach south GA next Wednesday morning. If
the GFS verifies, we would experience our first round of
below-average temperatures in quite some time.
&&
.AVIATION...
Patchy fog and low clouds will dissipate this morning, with
generally VFR conditions likely for the remainder of the day. The
exception will be periods of MVFR-IFR vis/cigs and gusty winds in
isolated to scattered thunderstorms, wich will be more numerous in
the afternoon. Low clouds will likely develop overnight, with
showers and thunderstorms developing near 12 UTC Thursday.
&&
.MARINE...
Winds and seas are expected to remain relatively low through
today, except for a slight increase in the afternoon hours near
the coast in association with the seabreeze. Onshore winds and seas
will increase on Thursday as a front approaches from the west to
borderline SCEC. Winds will turn offshore as the front passes on
Friday and likely reach advisory levels Fri night into Sat before
decreasing to below headline criteria and remaining offshore through
the weekend.
&&
.FIRE WEATHER...
Humidity levels are expected to remain above critical values through
Friday. Much drier air behind a cold front may allow red flag
conditions to develop this weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 86 66 84 63 82 / 20 20 70 50 20
Panama City 80 68 79 66 76 / 20 30 60 50 20
Dothan 87 66 84 59 79 / 30 40 70 40 20
Albany 87 65 83 60 78 / 40 30 70 50 20
Valdosta 86 64 84 62 80 / 40 20 70 60 30
Cross City 83 65 83 64 81 / 20 10 60 60 30
Apalachicola 80 67 79 68 76 / 10 20 60 50 20
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Block/Fournier
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1053 AM EDT WED APR 4 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A FRONTAL SYSTEM IS EXPECTED TO SETTLE SOUTH ACROSS THE AREA EARLY
TODAY...EVENTUALLY PUSHING SOUTH OF THE OHIO RIVER. A WAVE OF LOW
PRESSURE WILL MOVE THROUGH THE TENNESSEE VALLEY AROUND THURSDAY. IN
THE WAKE OF THIS LOW...HIGH PRESSURE IS EXPECTED TO MOVE INTO THE
AREA THROUGH THE END OF THE WEEK. ANOTHER FRONTAL SYSTEM MAY
APPROACH THE AREA OVER THE WEEKEND...WITH HIGH PRESSURE MOVING BACK
IN EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
SOME FRONTOGENESIS AND ISENTROPIC LIFT OVER THE AREA IS PRODUCING
SCATTERED SHOWERS ACROSS SOUTHERN AND WESTERN PARTS OF THE AREA AT
1445Z. EXPECT THESE TO CONTINUE TO DEVELOP AND SPREAD EAST OVER THE
NEXT COUPLE OF HOURS. IN ADDITION THESE SHOWERS COULD DEVELOP INTO
THUNDERSTORMS OVER THE NEXT FEW HOURS AS INSTABILITY INCREASES SO
KEPT A CHANCE FOR THUNDERSTORMS GOING LATE THIS MORNING AND INTO THE
AFTERNOON APPROXIMATELY SOUTH OF I 70 WITH A SLIGHT CHANCE TO THE
NORTH. THE HRRR MODEL IS SHOWING DEVELOPMENT ACROSS MUCH OF THE AREA
THIS AFTERNOON AND EVENING BUT GIVEN IT/S OUTLIER STATUS AND ITS
GENERALLY POORER PERFORMANCE LATELY GENERALLY THREW OUT IT/S MORE
ROBUST SOLUTION. TWEAKED DEW POINTS/WINDS/TEMPERATURES/SKY COVER TO
MATCH CURRENT CONDITIONS AND TRENDS BUT THIS RESULTED IN CHANGES OF
ONLY A COUPLE DEGREES HERE AND THERE WITH SLIGHTLY HIGHER DEWPOINTS
IN THE NORTH AS WELL AS SLIGHTLY WARMER TEMPERATURES IN THE SOUTH.
STILL GOING WITH HIGHS IN THE MIDDLE 60S TO LOW 70S.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
OVERRUNNING IS EXPECTED TO DEVELOP NORTH OF THE FRONTAL BOUNDARY BY
THIS EVENING AS AN UPPER LOW APPROACHES THE OHIO VALLEY FROM THE
WEST. LEFT IN CHANCE POPS ACROSS THE SOUTH FOR TONIGHT. ONCE SURFACE
WAVE PASSES THROUGH THE TENNESSEE VALLEY ON THURSDAY...HIGH PRESSURE
WILL NOSE SOUTH FROM CANADA...RESULTING IN DRY CONDITIONS BY
THURSDAY AND LASTING THE REST OF THE PERIOD.
REALLY DID NOT STRAY FAR FROM PREVIOUS FORECAST TEMPERATURES THIS
PERIOD. BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS
TEMPERATURE GUIDANCE LOOKS PRETTY REASONABLE. FREEZING TEMPERATURES
ARE STILL POSSIBLE BY FRIDAY MORNING...HOWEVER WINDS AT THE SURFACE
LOOK TO BE TOO STRONG FOR EVEN PATCHY FROST FORMATION...AND HAVE
DECIDED TO CONTINUE TO OMIT THIS MENTION FROM THE FORECAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD BEGINS WITH FAIRLY STRONG RIDGING AT THE SURFACE
AND ALOFT OVER THE AREA. AN UPPER LEVEL WAVE AND TRAILING COLD
FRONT MAKES PROGRESS INTO THE UPPER GREAT LAKES BY SATURDAY NIGHT
INTO EARLY SUNDAY...WITH AN OPPORTUNITY FOR SHOWERS AND
THUNDERSTORMS. A BRIEF QUIET WX PERIOD EXPECTED BEFORE ANOTHER
UPPER WAVE CONSOLIDATES WITH THE INITIAL SYSTEM AND PARKS OVER THE
NORTHEAST. THIS SYSTEM REPRESENTS THE ONLY SIGNIFICANT
DISAGREEMENT BETWEEN THE MAJOR MODELS...IN THAT THE EURO IS MUCH
MORE PROGRESSIVE WITH THE UPPER LOW. INITIALIZATION SEEMS TO BE
INFLUENCED SLIGHTLY MORE BY THE PROGRESSIVE SOLUTION...AND THIS IS
REASONABLE GIVEN THE ECMWF/S TYPICAL SUPERIORITY. THIS UPPER LOW
SHOULD BRING AT LEAST 12-24 HOURS OPPORTUNITY FOR SHOWERS TO THE
AREA.
INITIALIZATIONS TEMPS APPEAR REASONABLE WITH MINOR TWEAKS. COOLING
TREND SHOULD DOMINATE THE LONG TERM...WITH ABOVE NORMAL TEMPS EARLY
TRANSITIONING TO BELOW NORMAL TEMPS WITH THE UPPER LOW.
&&
.AVIATION /DISCUSSION FOR 15Z AMENDMENT/
LOOKS LIKE VFR CONDITIONS THRU THE DAY. WEAK AREA OF LOW PRESSURE
IS OVER SWRN MO WITH A QUASI STATIONARY BOUNDARY ACROSS SRN
INDIANA FROM NEAR KLWV - KCVG. LOW TO MID LEVEL CLOUDS ARE OVER IL
JUST NORTH OF THE BOUNDARY WITH MID LEVEL DECK ACROSS IN AND OH.
GUIDANCE SUGGESTS SOME LOW CLOUDS AROUND 5K FT AGL AROUND THIS
AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...CP
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...MCCARTHY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1133 AM EDT WED APR 4 2012
.UPDATE...
ISSUED AT 1043 AM EDT WED APR 4 2012
CONVECTION THAT WAS ATTEMPTING TO MOVE INTO THE REGION FROM CENTRAL
KY IN THE MORNING HAS DISSIPATED TO NOTHING MORE THAN SOME LOW TO
MID LEVEL CLOUDINESS. THERE IS A RATHER LARGE SECTION OF THE AREA
STARTING TO GET SOME SIGNIFICANT SUNSHINE. THE LINGERING VALLEY FOG
AND STRATUS IN THE CUMBERLAND VALLEY HAS DISSIPATED.
CONVECTIVE DEVELOPMENT TODAY WILL LIKELY HOLD OFF INTO THE EARLY TO
MID AFTERNOON...OR GENERALLY LATER THAN THE 12Z NAM IS PROJECTING.
THE APPROACHING BOUNDARY AS WELL AS MESOSCALE FEATURES SUCH AS
DIFFERENTIAL HEATING FROM TERRAIN OR ALONG THE INTERFACES BETWEEN
WHERE HEAVIER PRECIPITATION FELL ON TUE AFTERNOON/AND EVENING AND
WHERE IT WAS MUCH LIGHTER OR NEARLY RAINFREEE AND ANY LEFTOVER
OUTFLOWS ARE POSSIBLE POINTS WHERE DEVELOPMENT MIGHT OCCUR FIRST.
THE MID LEVEL IMPULSE MOVING TOWARD THE MID ATLANTIC STATES MAY HAVE
SOME FRINGE EFFECTS AS WELL THIS AFTERNOON INTO THIS EVENING IN
AIDING IN SOME ORGANIZATION TO THE CONVECTION. SHEAR AND INSTABILITY
PARAMETERS FORECAST BY THE MODELS APPEAR TO BE MORE OR LESS ON THE
MARGINAL END OF THE SPECTRUM WITH THE FORECAST SOUNDINGS MORE MOIST
WITH A BIT HIGHER PW COMPARED TO TUE. DEPENDING ON EVOLUTION OF
INSTABILITY...A FEW STORM COULD PRODUCE DAMAGING WINDS AND OR
MARGINALLY SEVERE HAIL AS NOTED IN THE MOST RECENT SPC OUTLOOK.
HOWEVER...THE FLASH FLOOD THREAT MAY BE GREATER. THE ORIENTATION OF
THE STALLED OR NEARLY STALLED OUT BOUNDARY SLOWLY SAGGING SOUTH OF
THE OH RIVER AND WESTERLY FLOW...BUT PROJECTED STORM MOTION NEAR 15KT
AND THE HIGH PW ON THE ORDER OF JUST UNDER 2SD ABOVE NORMAL DEFINITELY
POINTS TO A THREAT FOR SOME HEAVY RAIN WHERE THUNDERSTORMS OCCUR...AS
THERE COULD BE TRAINING.
SOME LOCATIONS HAD SOME WATER ISSUES YESTERDAY...ESPECIALLY LETCHER
COUNTY AND SOME LOCATIONS RECEIVED ABOUT 1 TO 2 INCHES OF RAIN FROM
THUNDERSTORMS ON TUE AFTERNOON OR EVENING...WITH LOCALLY HIGHER
AMOUNTS. GIVE ALL OF THESE FACTORS...WE WILL KEEP THE FLOOD WATCH IN
EFFECT AS IS FOR THIS UPDATE.
UPDATE ISSUED AT 745 AM EDT WED APR 4 2012
ISSUED A QUICK UPDATE TO ADJUST POPS IN THE NEAR TERM WITH THE LATEST
EXPECTATIONS OF THIS FIRST WAVE THIS MORNING AND THEN BUILDING IT UP
IN THE AFTERNOON A BIT FURTHER NORTH. IN ADDITION...UPDATED THE
TEMPS...WINDS AND DEWPOINTS TO BETTER REFLECT CURRENT CONDITIONS AND
TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 4 2012
07Z SFC ANALYSIS SHOWS A LOW CENTERED OVER SOUTHERN MISSOURI WITH A
WEST TO EAST WARM FRONT/ELONGATED AREA OF LOWER PRESSURE RUNNING
GENERALLY ALONG THE OHIO RIVER. THIS BOUNDARY HAS REMAINED
INTERMITTENTLY ACTIVE THROUGH THE NIGHT...EVEN AS THE MORE ROBUST...
DIURNALLY DRIVEN...SLOW MOVING CONVECTION DIED OUT OVER EAST
KENTUCKY DURING THE LATE EVENING. DO EXPECT THAT THIS REGION OF LOWER
PRESSURE WILL BECOME MORE ACTIVE TOWARD DAWN IN CONJUNCTION WITH A
SLOW MOVING BAND OF MID LEVEL SHORTWAVES RUNNING THROUGH THE
SOUTHERN OHIO VALLEY. THE ENVIRONMENT IS RELATIVELY MOIST OVER THE
AREA WITH DEWPOINTS RUNNING IN THE MID AND UPPER 50S WHILE
TEMPERATURES ARE SETTLING INTO THE LOWER 60S IN MOST PLACES...EARLY
THIS MORNING.
THE MODELS ARE IN DECENT AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL ROLL A CLOSED AND SOMEWHAT CUT OFF
LOW THROUGH THE SOUTHERN PLAINS AND TOWARDS THE LOWER OHIO VALLEY BY
THURSDAY MORNING. FLAT RIDGING AND DEEP SOUTHWEST FLOW EXIST OUT
AHEAD OF THIS LOW AFFECTING KENTUCKY AND THIS WILL BE SQUEEZED OFF
TO THE EAST BY 12Z THURSDAY. AT THE SAME TIME...A DEEP TROUGH OVER
THE NORTHEAST WILL SHIFT SLIGHTLY SOUTH. GIVEN THE MODEL SIMILARITIES
ALOFT HAVE GONE WITH A BLENDED SOLUTION WITH A LEAN TOWARD THE
HIGHER RESOLUTION NAM12...AND A NOD TO THE HRRR IN THE NEAR TERM...
BUT TRANSLATED SLIGHTLY SOUTH IN LINE WITH THE OTHER MODELS LATTER IN
THE SHORT TERM.
AN ACTIVE WEATHER PERIOD IS UPON US WITH THE APPROACH OF THE UPPER
LOW TO THE WEST AND THE STALLED BOUNDARY LAYING OVER NORTHERN PARTS
OF EAST KENTUCKY. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
AND INCREASE THROUGH THE AREA LATER TODAY AS DIURNAL HEATING
INITIATES CONVECTION...HELPED ALONG BY SFC CONVERGENCE WITH THE
BOUNDARY AND SOME UPPER LEVEL DIVERGENCE. THE STEAMY BOUNDARY LAYER
WILL CONTRIBUTE TO HIGH INSTABILITY TODAY WITH MID LEVEL WINDS
FAVORABLE FOR MORE ORGANIZED CONVECTION. AS A RESULT...STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH THE AREA WITH HIGH PW
AIR SETTING THE STAGE FOR HEAVY RAIN FROM ANY HEALTHY STORMS.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREAT FROM THESE. THE
STORMS WILL BE MORE PROGRESSIVE THAN YESTERDAY...BUT TRAINING...AND
PLENTY OF AREAS OF LOWER FFG AFTER YESTERDAY/S RAINS...WILL MAKE
FLASH FLOODING A CONCERN LATER TODAY AND THROUGH THE FIRST PART OF
THE NIGHT. ACCORDINGLY...WILL HOIST A FLASH FLOOD WATCH FOR ALL BUT
OUR NORTHWEST COUNTIES. THE HEAVIER RAINS WILL DISSIPATE BY THURSDAY
MORNING AS DRIER AIR SEEPS INTO THE REGION FROM THE NORTH...BUT THE
THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE DAY. THE
BAROCLINIC ZONE IN PLACE THROUGH THE AREA ON THURSDAY WILL KEEP THE
NORTHERN COUNTIES UP TO 10 DEGREES COOLER THAN THE SOUTHERN ONES FOR
HIGHS.
HAVE FOLLOWED A BLEND OF THE MOS GUIDANCE THROUGH THE PERIOD ALLOWING
THE MAV NUMBERS TO TEMPER THE MET/S...WITH LITTLE IN THE WAY OF
TERRAIN ADJUSTMENTS GIVEN THE MOIST ENVIRONMENT. DID FAVOR THE MET
POPS THROUGH THE SHORT TERM...BUT HAD THEM TRANSLATED MORE TO THE
SOUTH OWING TO THE CONSENSUS FAVORING MORE SUPPRESSION OF THE FRONTAL
BOUNDARY FROM THE HIGH TO THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 AM EDT WED APR 4 2012
THE MODELS ARE IN GOOD AGREEMENT REGARDING THE EVOLUTION OF WEATHER
SYSTEMS FOR THE DAY 4-7 PERIOD. INITIALLY...SCATTERED RAIN SHOWERS
WILL BE PRESENT FROM THE TENNESSEE BORDER NORTHWARD TO THE HAL
ROGERS PARKWAY AND ALONG AND NORTH OF THE HIGHWAY 80 CORRIDOR. THESE
RAIN SHOWERS WILL LIKELY LINGER THROUGH 9 OR 10Z ACROSS THIS AREA ON
FRIDAY MORNING...BEFORE EXITING INTO VIRGINIA BY 13Z OR SO. AFTER
THAT...THE MODELS ALL AGREE THAT HIGH PRESSURE WILL BECOME FIRMLY
ESTABLISHED ACROSS THE OHIO AND TENNESSEE VALLEY AREAS THROUGH
SUNDAY MORNING. THE GFS AND ECMWF BOTH ARE QUICKLY MOVING A WEAK
FRONTAL BOUNDARY AND UPPER LEVEL TROUGH ACROSS THE REGION ON SUNDAY.
THESE FEATURES WILL JUST STRONG ENOUGH AND HAVE JUST ENOUGH MOISTURE
ASSOCIATED WITH THEM TO SPARK ISOLATED TO SCATTERED RAIN SHOWERS. AT
THIS TIME THE MODEL DATA INDICATE THAT THE ATMOSPHERE WILL ONLY BE
ABLE TO SUPPORT ISOLATED THUNDERSTORM ACTIVITY. WITH ALL THAT IN
MIND...THE INHERITED FORECAST FOR SUNDAY WAS ADJUSTED TO REFLECT
PRECIPITATION CHANCE THAT WERE A GOOD DEAL LOWER...AND MORE IN LINE
WITH THE LATEST MEXMOS DATA...WHICH WAS REFLECTIVE OF 20-30 PERCENT
PRECIPITATION PROBABILITIES ACROSS THE BOARD. ANOTHER AREA OF WEAK
HIGH PRESSURE WILL THEN BECOME ESTABLISHED ACROSS THE SUNDAY NIGHT
AND MONDAY. ANOTHER EVEN MORE ILL DEFINED FRONTAL BOUNDARY AND UPPER
TROUGH COMBO WILL BRING SCATTERED RAIN SHOWERS TO EASTERN KENTUCKY
MONDAY NIGHT AND TUESDAY. THE WEATHER...SKY COVER...AND
PRECIPITATION AMOUNT FORECASTS WERE ALL ADJUSTED BASED ON THE LOWER
PRECIPITATION PROBABILITIES. ACCOUNTING FOR THE AMOUNT OF CLOUD
COVER AND PRECIPITATION EXPECTED...AND WITH SOMEWHAT COOLER AIR
MASSES EXPECTED TO MOVE ACROSS THE AREA...TEMPERATURES WILL BE VERY
CLOSE TO NORMAL THROUGH MONDAY...AND MAY EVEN BE SEVERAL DEGREES
BELOW NORMAL NEXT TUESDAY AS COOLER AIR MAKES A FAIRLY DEEP
SOUTHWARD INTRUSION INTO THE EASTERN CONUS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 745 AM EDT WED APR 4 2012
WITH THE WARM FRONT LYING ACROSS THE AREA...CONVECTION IS POSSIBLE
AT ALMOST ANYTIME AND ANYWHERE THROUGHOUT EAST KENTUCKY. DO EXPECT
THE ACTIVITY TO BE AT A MINIMUM EARLY THIS MORNING FOR MOST PLACES...
EXCEPT UP IN THE NORTH THANKS TO A PASSING SHORT WAVE. OTHERWISE...
WILL LET THE DIURNAL CYCLE DRIVE THE DEVELOPMENT AND EXPANSION OF
SHOWERS AND THUNDERSTORMS THROUGH THE AREA THIS AFTERNOON AND INTO
THE EVENING. WITH THIS...HAVE ADDED VCTS INTO THE TAFS AFTER 14Z.
STILL ANTICIPATE A LULL IN THE ACTIVITY UNTIL MIDDAY FOR
MOST OF THE AREA AND THEN CONVECTION SHOULD BLOSSOM FROM LATE
AFTERNOON AND LAST WELL INTO THE EVENING. ANY STORM WILL BRING WITH
IT MVFR CIGS AND VIS DOWN TO IFR OR LESS IN HEAVY RAIN. STORMS AND
MVFR CONDITIONS WILL BE POSSIBLE THROUGH 12Z THURSDAY. WINDS THROUGH
THE PERIOD WILL BE GENERALLY FROM THE WEST AT 5 TO 10 KTS THROUGH
THE PERIOD...THOUGH HIGHER IN AND AROUND ANY STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KYZ058>060-068-069-
079-080-083>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM....AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
745 AM EDT WED APR 4 2012
.UPDATE...
ISSUED AT 745 AM EDT WED APR 4 2012
ISSUED A QUICK UPDATE TO ADJUST POPS IN THE NEAR TERM WITH THE LATEST
EXPECTATIONS OF THIS FIRST WAVE THIS MORNING AND THEN BUILDING IT UP
IN THE AFTERNOON A BIT FURTHER NORTH. IN ADDITION...UPDATED THE
TEMPS...WINDS AND DEWPOINTS TO BETTER REFLECT CURRENT CONDITIONS AND
TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 4 2012
07Z SFC ANALYSIS SHOWS A LOW CENTERED OVER SOUTHERN MISSOURI WITH A
WEST TO EAST WARM FRONT/ELONGATED AREA OF LOWER PRESSURE RUNNING
GENERALLY ALONG THE OHIO RIVER. THIS BOUNDARY HAS REMAINED
INTERMITTENTLY ACTIVE THROUGH THE NIGHT...EVEN AS THE MORE ROBUST...
DIURNALLY DRIVEN...SLOW MOVING CONVECTION DIED OUT OVER EAST
KENTUCKY DURING THE LATE EVENING. DO EXPECT THAT THIS REGION OF LOWER
PRESSURE WILL BECOME MORE ACTIVE TOWARD DAWN IN CONJUNCTION WITH A
SLOW MOVING BAND OF MID LEVEL SHORTWAVES RUNNING THROUGH THE
SOUTHERN OHIO VALLEY. THE ENVIRONMENT IS RELATIVELY MOIST OVER THE
AREA WITH DEWPOINTS RUNNING IN THE MID AND UPPER 50S WHILE
TEMPERATURES ARE SETTLING INTO THE LOWER 60S IN MOST PLACES...EARLY
THIS MORNING.
THE MODELS ARE IN DECENT AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL ROLL A CLOSED AND SOMEWHAT CUT OFF
LOW THROUGH THE SOUTHERN PLAINS AND TOWARDS THE LOWER OHIO VALLEY BY
THURSDAY MORNING. FLAT RIDGING AND DEEP SOUTHWEST FLOW EXIST OUT
AHEAD OF THIS LOW AFFECTING KENTUCKY AND THIS WILL BE SQUEEZED OFF
TO THE EAST BY 12Z THURSDAY. AT THE SAME TIME...A DEEP TROUGH OVER
THE NORTHEAST WILL SHIFT SLIGHTLY SOUTH. GIVEN THE MODEL SIMILARITIES
ALOFT HAVE GONE WITH A BLENDED SOLUTION WITH A LEAN TOWARD THE
HIGHER RESOLUTION NAM12...AND A NOD TO THE HRRR IN THE NEAR TERM...
BUT TRANSLATED SLIGHTLY SOUTH IN LINE WITH THE OTHER MODELS LATTER IN
THE SHORT TERM.
AN ACTIVE WEATHER PERIOD IS UPON US WITH THE APPROACH OF THE UPPER
LOW TO THE WEST AND THE STALLED BOUNDARY LAYING OVER NORTHERN PARTS
OF EAST KENTUCKY. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
AND INCREASE THROUGH THE AREA LATER TODAY AS DIURNAL HEATING
INITIATES CONVECTION...HELPED ALONG BY SFC CONVERGENCE WITH THE
BOUNDARY AND SOME UPPER LEVEL DIVERGENCE. THE STEAMY BOUNDARY LAYER
WILL CONTRIBUTE TO HIGH INSTABILITY TODAY WITH MID LEVEL WINDS
FAVORABLE FOR MORE ORGANIZED CONVECTION. AS A RESULT...STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH THE AREA WITH HIGH PW
AIR SETTING THE STAGE FOR HEAVY RAIN FROM ANY HEALTHY STORMS.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREAT FROM THESE. THE
STORMS WILL BE MORE PROGRESSIVE THAN YESTERDAY...BUT TRAINING...AND
PLENTY OF AREAS OF LOWER FFG AFTER YESTERDAY/S RAINS...WILL MAKE
FLASH FLOODING A CONCERN LATER TODAY AND THROUGH THE FIRST PART OF
THE NIGHT. ACCORDINGLY...WILL HOIST A FLASH FLOOD WATCH FOR ALL BUT
OUR NORTHWEST COUNTIES. THE HEAVIER RAINS WILL DISSIPATE BY THURSDAY
MORNING AS DRIER AIR SEEPS INTO THE REGION FROM THE NORTH...BUT THE
THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE DAY. THE
BAROCLINIC ZONE IN PLACE THROUGH THE AREA ON THURSDAY WILL KEEP THE
NORTHERN COUNTIES UP TO 10 DEGREES COOLER THAN THE SOUTHERN ONES FOR
HIGHS.
HAVE FOLLOWED A BLEND OF THE MOS GUIDANCE THROUGH THE PERIOD ALLOWING
THE MAV NUMBERS TO TEMPER THE MET/S...WITH LITTLE IN THE WAY OF
TERRAIN ADJUSTMENTS GIVEN THE MOIST ENVIRONMENT. DID FAVOR THE MET
POPS THROUGH THE SHORT TERM...BUT HAD THEM TRANSLATED MORE TO THE
SOUTH OWING TO THE CONSENSUS FAVORING MORE SUPPRESSION OF THE FRONTAL
BOUNDARY FROM THE HIGH TO THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 AM EDT WED APR 4 2012
THE MODELS ARE IN GOOD AGREEMENT REGARDING THE EVOLUTION OF WEATHER
SYSTEMS FOR THE DAY 4-7 PERIOD. INITIALLY...SCATTERED RAIN SHOWERS
WILL BE PRESENT FROM THE TENNESSEE BORDER NORTHWARD TO THE HAL
ROGERS PARKWAY AND ALONG AND NORTH OF THE HIGHWAY 80 CORRIDOR. THESE
RAIN SHOWERS WILL LIKELY LINGER THROUGH 9 OR 10Z ACROSS THIS AREA ON
FRIDAY MORNING...BEFORE EXITING INTO VIRGINIA BY 13Z OR SO. AFTER
THAT...THE MODELS ALL AGREE THAT HIGH PRESSURE WILL BECOME FIRMLY
ESTABLISHED ACROSS THE OHIO AND TENNESSEE VALLEY AREAS THROUGH
SUNDAY MORNING. THE GFS AND ECMWF BOTH ARE QUICKLY MOVING A WEAK
FRONTAL BOUNDARY AND UPPER LEVEL TROUGH ACROSS THE REGION ON SUNDAY.
THESE FEATURES WILL JUST STRONG ENOUGH AND HAVE JUST ENOUGH MOISTURE
ASSOCIATED WITH THEM TO SPARK ISOLATED TO SCATTERED RAIN SHOWERS. AT
THIS TIME THE MODEL DATA INDICATE THAT THE ATMOSPHERE WILL ONLY BE
ABLE TO SUPPORT ISOLATED THUNDERSTORM ACTIVITY. WITH ALL THAT IN
MIND...THE INHERITED FORECAST FOR SUNDAY WAS ADJUSTED TO REFLECT
PRECIPITATION CHANCE THAT WERE A GOOD DEAL LOWER...AND MORE IN LINE
WITH THE LATEST MEXMOS DATA...WHICH WAS REFLECTIVE OF 20-30 PERCENT
PRECIPITATION PROBABILITIES ACROSS THE BOARD. ANOTHER AREA OF WEAK
HIGH PRESSURE WILL THEN BECOME ESTABLISHED ACROSS THE SUNDAY NIGHT
AND MONDAY. ANOTHER EVEN MORE ILL DEFINED FRONTAL BOUNDARY AND UPPER
TROUGH COMBO WILL BRING SCATTERED RAIN SHOWERS TO EASTERN KENTUCKY
MONDAY NIGHT AND TUESDAY. THE WEATHER...SKY COVER...AND
PRECIPITATION AMOUNT FORECASTS WERE ALL ADJUSTED BASED ON THE LOWER
PRECIPITATION PROBABILITIES. ACCOUNTING FOR THE AMOUNT OF CLOUD
COVER AND PRECIPITATION EXPECTED...AND WITH SOMEWHAT COOLER AIR
MASSES EXPECTED TO MOVE ACROSS THE AREA...TEMPERATURES WILL BE VERY
CLOSE TO NORMAL THROUGH MONDAY...AND MAY EVEN BE SEVERAL DEGREES
BELOW NORMAL NEXT TUESDAY AS COOLER AIR MAKES A FAIRLY DEEP
SOUTHWARD INTRUSION INTO THE EASTERN CONUS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 745 AM EDT WED APR 4 2012
WITH THE WARM FRONT LYING ACROSS THE AREA...CONVECTION IS POSSIBLE
AT ALMOST ANYTIME AND ANYWHERE THROUGHOUT EAST KENTUCKY. DO EXPECT
THE ACTIVITY TO BE AT A MINIMUM EARLY THIS MORNING FOR MOST PLACES...
EXCEPT UP IN THE NORTH THANKS TO A PASSING SHORT WAVE. OTHERWISE...
WILL LET THE DIURNAL CYCLE DRIVE THE DEVELOPMENT AND EXPANSION OF
SHOWERS AND THUNDERSTORMS THROUGH THE AREA THIS AFTERNOON AND INTO
THE EVENING. WITH THIS...HAVE ADDED VCTS INTO THE TAFS AFTER 14Z.
STILL ANTICIPATE A LULL IN THE ACTIVITY UNTIL MIDDAY FOR
MOST OF THE AREA AND THEN CONVECTION SHOULD BLOSSOM FROM LATE
AFTERNOON AND LAST WELL INTO THE EVENING. ANY STORM WILL BRING WITH
IT MVFR CIGS AND VIS DOWN TO IFR OR LESS IN HEAVY RAIN. STORMS AND
MVFR CONDITIONS WILL BE POSSIBLE THROUGH 12Z THURSDAY. WINDS THROUGH
THE PERIOD WILL BE GENERALLY FROM THE WEST AT 5 TO 10 KTS THROUGH
THE PERIOD...THOUGH HIGHER IN AND AROUND ANY STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 11 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM....AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
959 AM MDT WED APR 4 2012
.UPDATE...
CLOUD COVER AND THE LINGERING EASTERLY WINDS HAS KEPT MUCH OF THE
AREA A BIT COOLER THAN FORECAST. SHORT RANGE MODELS SHOW THAT EVEN
WITH THIS DELAY IN THE HEATING AND THE WARMING DOWNSLOPE WINDS
THAT IT WILL COME BY THIS AFTERNOON AS THE SFC LOW MOVES INTO THE
NORTH CENTRAL MONTANA PLAINS AND THE WARMING WESTERLY OR
SOUTHWESTERLY WINDS WILL SET-UP AND THE CLOUDINESS WILL WANE
ALLOWING FOR MORE INSOLATION/HEATING. HAVE ADJUSTED THE HOURLY
TEMPS TO ACCOUNT FOR THE LOWER TEMPS THAN EXPECTED THIS LATE
MORNING AND THE WARMING AS THE CLOUDS BREAK THIS AFTERNOON AND THE
WINDS PICK UP. OTHER PORTIONS OF THE FORECAST STILL LOOK FINE WITH
RESPECT TO FIRE WEATHER CONCERNS ACROSS SW MONTANA...AND PRECIP
CHANCES DUE TO AN SCATTERED SHOWER OR ISOLATED THUNDERSTORMS ACROSS
NORTH CENTRAL MONTANA. RUC SHOWING CAPES NEARING 250-350J/KG AND
DECENT MID LVL LAPSE RATES AROUND 8.5 DEGREES C BY THIS AFTERNOON
AND SHOULD ALLOW FOR THE FORECASTED AFTN ISOLATED T-STORMS. --SCHOTT
&&
.AVIATION...
UPDATED 1150Z.
EXPECT VFR CONDITIONS EXCEPT OVER THE ROCKY MOUNTAIN FRONT WHERE
MOUNTAINS WILL BECOME OBSCURED IN SNOW THIS AFTERNOON AND TONIGHT. A
COLD FRONT IS EXPECTED TO REACH KCTB AND KHLN AROUND 20Z...KGTF AND
KBZN 21Z-22Z AND KHVR AND KLWT AROUND 00Z. THE BEST BET FOR SHOWERS
BEHIND THE COLD FRONT IS AT KCTB WITH SMALL THREATS AT
KHLN/KGTF/KHVR. DO NOT EXPECT ANY SHOWERS AT KLWT AND KBZN. GUSTY
SOUTHWEST WINDS ARE EXPECTED IMMEDIATELY BEHIND THE COLD FRONT BUT
THEN ARE EXPECTED TO SHIFT TO THE WEST OR NORTHWEST THIS EVENING.
DETAILS ON THE TIMING OF THE WIND SHIFT TO THE WEST OR NORTHWEST ARE
UNCERTAIN. DO NOT HAVE A GOOD FEEL ON WHETHER THERE WILL BE ISOLATED
THUNDERSTORMS THIS AFTERNOON. SOME GUIDANCE SUGGESTS THERE WILL BE
NONE WHILE OTHER GUIDANCE SUGGESTS THERE WILL BE A SMALL THREAT.
BLANK
&&
.PREV DISCUSSION...
/ISSUED 550 AM MDT WED APR 4 2012/
TODAY THROUGH FRIDAY...THE BEGINNING OF AN ACTIVE PERIOD OF
WEATHER WILL START TODAY...AND THEN CONTINUE INTO FRIDAY. A
PACIFIC COLD FRONT...CURRENTLY JUST MOVING INTO WESTERN MONTANA AT
4 AM...WILL MOVE SLOWLY EASTWARD TOWARDS CENTRAL MONTANA TODAY.
EXPECT THIS FRONT TO MOVE EAST OF THE DIVIDE THIS AFTERNOON...AND
THEN GRADUALLY MOVE THROUGH THE LEWISTOWN AREA THIS EVENING.
MILD TEMPERATURES ARE EXPECTED AHEAD OF THE FRONT...WITH THE
WARMEST LOCATIONS EXPECTED IN THE HAVRE/LEWISTOWN AREAS TODAY. AS
THE FRONT MOVES EAST OF THE DIVIDE...EXPECT SCATTERED SHOWERS TO
DEVELOP ALONG WITH A FEW THUNDERSTORMS. THE DYNAMICS ARE GOOD WITH
THIS SYSTEM...BUT THE INSTABILITY IS LOW. SO FOR NOW...I REMOVED
THE GUSTY WIND WORDING IN THE ZONES...BUT WE WILL CONTINUE TO
WATCH THIS CLOSELY. AGAIN...COOLER AIR MOVES INTO THE REGION
TONIGHT. AS THE MAIN STORM SYSTEM PULLS NORTHWARD INTO CANADA...A
BAND OF PRECIPITATION IS EXPECTED TO DEVELOP OVER SOUTHWEST
MONTANA. SOME SNOW IS LIKELY BY MORNING BETWEEN DILLON AND BIG
SKY. FOR NOW...THE BEST ACCUMULATING SNOWFALL SHOULD BE ABOVE 7000
FEET...SO I WILL HOLD OFF ON AN ADVISORY FOR NOW. THE PRECIP WILL
CONTINUE INTO THURSDAY OVER SOUTHWEST MONTANA...WITH JUST A FEW
SHOWERS OVER CENTRAL MONTANA...WHILE THE HI-LINE AREA STAYS MOSTLY
DRY ON THURSDAY AFTERNOON. AFTERNOON TEMPERATURES ON THURSDAY WILL
BE CLOSE TO 20 DEGREES COOLER THAN WEDNESDAY. THEN FOR THURSDAY
NIGHT AND INTO FRIDAY...BOTH THE EC/GFS MODEL PROG A STRONG AREA
OF LOW PRESSURE TO DEVELOP OVER SOUTHERN WYOMING...AND THEN MOVE
NORTHEASTWARD INTO THE UPPER MIDWEST. THIS TRACK WOULD ALLOW FOR
HEAVY SNOW TO DEVELOP IN THE MOUNTAINS OF SOUTHWEST MONTANA ON
THURSDAY NIGHT AND THEN SPREAD NORTHWARD INTO CENTRAL MONTANA BY
FRIDAY MORNING. THE HEAVIEST SNOWFALL SHOULD OCCUR IN THE
MOUNTAINS WITH THIS SYSTEM...BUT SEVERAL INCHES OF SNOW ARE
POSSIBLE AT LOWER ELEVATIONS IN SOUTHWEST/CENTRAL MONTANA. THUS A
WINTER STORM WATCH HAS BEEN ISSUED FOR ALL ELEVATIONS. AFTERNOON
TEMPERATURES ON FRIDAY WILL CONTINUE THE COOLING TREND...WITH THE
CLOUDS/PRECIP...MOST AREAS WILL ONLY SEE HIGHS IN THE 30S. BRUSDA
FRIDAY NIGHT THROUGH WEDNESDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT
DURING THE PERIOD SO CONFIDENCE IN THE FORECAST IS ABOVE AVERAGE.
FRIDAY NIGHT THE UPPER TROUGH OVER EASTERN MONTANA WILL MOVE SLOWLY
EAST AND EXPECT SNOW TO DIMINISH. SATURDAY NORTHWEST FLOW IS
EXPECTED ALONG WITH SOME RESIDUAL MOISTURE. DID NOT CHANGE THE
INHERITED FORECAST WHICH HAD A SLIGHT CHANCE OF PRECIPITATION OVER
THE PLAINS WITH A CHANCE OF SNOW OVER THE MOUNTAINS. THEREAFTER THE
FORECAST AREA WILL BE UNDER THE INFLUENCE OF A STRONG UPPER RIDGE
WHICH WILL MOVE OVER CENTRAL MONTANA MONDAY. THIS WILL RESULT IN A
WARMING TREND WITH HIGHS REACHING THE MID 50S TO MID 60S ON MONDAY.
MODELS DIFFER SOME ON HOW FAST THE UPPER RIDGE MOVES EAST THEREAFTER
BUT IT LOOKS LIKE WARM TEMPERATURES WILL CONTINUE INTO MIDWEEK. AS
FOR PRECIPITATION THE RIDGE SHOULD KEEP THE AREA DRY SATURDAY NIGHT
THROUGH TUESDAY WITH THE POSSIBLE EXCEPTION OF THE MOUNTAINS OF THE
ROCKY MOUNTAIN FRONT. MODELS ARE POINTING TO SOME INCREASE IN
MOISTURE BY WEDNESDAY OR WEDNESDAY NIGHT SO WENT WITH A SLIGHT
CHANCE OF SHOWERS FOR THE LOWER ELEVATIONS AND A CHANCE OF RAIN OR
SNOW SHOWERS FOR THE MOUNTAINS BY LATE WEDNESDAY. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 69 30 46 29 / 20 20 20 40
CTB 64 27 45 24 / 40 40 20 10
HLN 71 29 46 29 / 20 10 30 50
BZN 66 27 43 27 / 10 20 50 60
WEY 38 21 37 21 / 10 40 60 70
DLN 61 25 41 26 / 20 10 50 60
HVR 74 31 51 27 / 10 30 10 10
LWT 70 29 43 27 / 10 10 30 50
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY EVENING
BEAVERHEAD...BROADWATER...CASCADE...FERGUS...GALLATIN...
JEFFERSON...JUDITH BASIN...MADISON...MEAGHER.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR ELEVATIONS
BELOW 6000 FEET FOR GALLATIN...MADISON...MEAGHER.
&&
$$
UPDATE...SCHOTT
SHORT TERM...BRUSDA
LONG TERM...BLANK
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
646 AM EDT WED APR 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY, BRINGING SUNNY SKIES LATER THIS
MORNING AND BREEZY CONDITIONS. HIGH PRESSURE WILL KEEP QUIET
WEATHER OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
645AM UPDATE...CURRENT FORECAST IS ON TRACK. CLOUD COVER IS
BEGINNING TO BREAK UP AT A QUICKER PACE THIS MORNING AS THOUGHT.
WINDS ARE SOMEWHAT LIGHTER THAN FORECAST, BUT STILL WITHIN REASON
COMPARED TO THE FORECAST. NO REAL CHANGES OTHER THAN SOME TWEAKS
TO THE ENHANCED SHORT TERM GRIDS.
PREVIOUS DISCUSSION...IR IMAGERY AND GROUND OBS STILL SHOWING
CLOUD COVER OVER MOST OF THE CWA, WITH SOME CLEARING FROM THE NW.
THIS CLEARING WILL SLOWLY CONTINUE UNTIL AROUND DAY BREAK WHEN
MIXING BEGINS TO CLEAR IT OUT SOMEWHAT FASTER. THIS WILL ALLOW FOR
SUNNY SKIES LATER THIS MORNING AND THE REST OF THE DAY. AS HIGH
PRESSURE BUILDS IN, THE PRESSURE GRADIENT WILL INCREASE OVER THE
CWA, ALLOWING FOR WINDS TO INCREASE WITH GUSTS TO AROUND 20 MPH.
RELATIVE HUMIDITY WILL BE FAIRLY DRY TODAY, DROPPING TO AROUND 30
PERCENT. MODELS HAVE MORE MOISTURE THAN THAT, BUT THINKING IS THEY
ARE OVER DOING SFC MOISTURE, SO HAVE LOWERED DEW POINTS INTO THE
UPPER 20S TO LOW 30S TODAY. THE HRRR SEEMS TO HAVE ONE OF THE BEST
HANDLES ON THE RH TODAY. IT DOES SHOW INCREASING RH FROM THE NW
THIS MORNING, ONLY TO FALL OFF LATE MORNING AND AFTERNOON AS
MIXING OCCURS. EVEN WITH THE LOWERING RH, IT STILL SHOWS RH VALUES
IN THE 40 PERCENT RANGE. SO, STARTING THERE AND TAKING ABOUT 10
PERCENT OFF OF THAT, STILL KEEPS FIRE WEATHER CONCERNS MARGINAL AT
BEST. NOT TO MENTION, THE PRECIP CRITERIA HAS NOT BEEN MET FOR NY,
AS MUCH OF THE CWA RECEIVED OVER A QUARTER INCH OF RAIN ON SUNDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE REMAINDER OF THE
WEEK. THIS WILL KEEP THE WEATHER QUIET. LOOKING AT TEMPS TONIGHT,
THEY WILL COOL TO THE LOWER 30S. THERE MAY BE SOME LOCALIZED AREAS
OF BELOW FREEZING TEMPS, BUT NOT EXPECTED TO BE WIDESPREAD AT THIS
TIME IN AREAS WHERE THE GROWING SEASON HAS STARTED. THUS, HAVE
OPTED NOT TO ISSUE ANY PRODUCTS AT THIS TIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
.0345 AM UPDATE... VERY FEW CHANGES MADE TO THE LONG TERM AS
PREVIOUS FORECAST HAD A GOOD HANDLE ON EXPECTED CONDITIONS. IN
GENERAL...DRY/SEASONAL CONDITIONS EXPECTED TOWARDS THE START OF
THE PERIOD WITH AN EVENTUAL SHIFT TOWARDS UNSETTLED CONDITIONS AND
BELOW NORMAL TEMPS EARLY NEXT WEEK AS AN UPPER VORTEX BECOMES
FIRMLY ESTABLISHED ACROSS EASTERN CANADA. BOTH GFS AND ECMWF
SHOWING SURPRISING AGREEMENT WITH THE EVOLUTION OF THIS
FEATURE...WITH BOTH AGREEING UPPER LOW WILL TAKE UP RESIDENCE
ACROSS THE UPPER ST. LAWRENCE VALLEY BY MONDAY.
UNFORTUNATELY...OUR REGION WILL BE EMBEDDED IN NORTHERLY FLOW TO
THE SYSTEM/S WEST WHICH WILL SET UP A FAVORABLE CORRIDOR FOR THE
PASSAGE OF UPPER SHORTWAVE DISTURBANCES ACROSS OUR REGION. BASED
ON FAVORABLE MODEL AGREEMENT...HAVE LOWERED DAYTIME HIGHS A FEW
DEGREES EACH DAY BEGINNING MON.
.PREVIOUS LONG TERM DISCUSSION...
THE LONG TERM STARTS OFF WITH HIGH PRESSURE IN CONTROL WITH FAIR
AND MAINLY CLEAR WX FOR FRI AND SAT AND MOST OF SUNDAY. LATER ON
SUNDAY...A WEAK FNTL SYSTEM MAY BRING AN INCREASE IN CLDS AND THE
CHC FOR A FEW -SHRA ON SUN NGT. AFTER THIS TIME MDLS ARE IN PRETTY
GOOD AGREEMENT THAT AN UPR TROF WILL BE AMPLIFYING OVER THE RGN
WITH A TREND TWDS COOLER AND WETTER CONDITIONS TAKING HOLD. WE
FOLLOWED HPC GDNC FOR THE MOST PART...BUT LOWERED MAXES A BIT FOR
EARLY NXT WEEK GIVEN MDL TRENDS AND LATEST MOS GDNC.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS TO START OUT THE TAF PERIOD THIS MORNING AS LOW
CLOUDS CONTINUE TO SLOWLY SLIDE SOUTH AND EAST OF THE REGION. BIG
CONCERNS FOR TODAY WILL BE INCREASING WINDS BEHIND A WEAK COLD
FRONT ALONG WITH INCREASING CLOUDS (POSSIBLE MVFR CIGS) THIS
AFTERNOON. FOR NOW BEST POTENTIAL FOR MVFR CIGS WILL BE AT
SYR/RME/ITH/BGM THIS AFTERNOON AFTER 18Z FOLLOWING FRONTAL
PASSAGE. CONDITIONS MAY TEMPORARILY IMPROVE NEAR 00Z THIS
EVENING...HOWEVER MODELS CONTINUE TO SUGGEST A RETURN OF MVFR CIGS
AFTER 06Z AS LOW-LEVEL MOISTURE LINGERS AROUND. THE ONLY TWO
LOCATIONS WHERE RESTRICTIONS ARE NOT EXPECTED AT THIS TIME INCLUDE
BOTH AVP AND ELM AS BOTH SITES WILL REMAIN ALONG THE SOUTHERN EDGE
OF THE DEVELOPING CLOUD SHIELD.
THE OTHER STORY WILL BE INCREASING NORTHWESTERLY WINDS AFTER 14Z
AS A STRONG PRESSURE GRADIENT REMAINS OVER THE AREA. EXPECT WIND
GUSTS OF NEAR 25 KTS ACROSS THE FINGER LAKES AND TWIN TIERS...WITH
GUSTS POSSIBLY APPROACHING 30 KTS AT BOTH SYR AND RME. WINDS WILL
DECREASE THIS EVENING AS THE PRESSURE GRADIENT BEGINS TO WEAKEN
WITH TIME.
.OUTLOOK...
THU THROUGH SUN...VFR.
&&
.FIRE WEATHER...
WHILE THERE IS A HIGH FIRE DANGER IN SOME AREAS, RED FLAG CRITERIA
LOOKS TO NOT BE MET, OR FAIRLY MARGINAL IN SOME AREAS. FOR THE NEW
YORK AREA, RAIN ON SUNDAY OF MORE THAN A QUARTER OF AN INCH OVER A
LARGE AREA, HAS KEPT THE CRITERIA FROM BEING MET. ALSO, RELATIVE
HUMIDITY WILL DROP TODAY. HOWEVER, IT DOES LOOK TO REMAIN IN THE
LOW 30 PERCENT RANGE IN THE CATSKILL AREA. ALSO, WINDS ARE
EXPECTED TO BE GUSTY TODAY, WITH SOME GUSTS APPROACHING 25 MPH,
AGAIN, ESPECIALLY IN THE CATSKILL REGION. THIS, WHEN COMBINED WITH
LOW FUEL MOISTURE, WOULD CAUSE BORDERLINE CONDITIONS, BUT NOT
EXPECTING EXPLOSIVE FIRE GROWTH POTENTIAL AT THIS TIME.
TEMPS WILL BE NEAR FREEZING OVER MUCH OF THE AREA TONIGHT. RH
RECOVERY WILL BE MODERATE, WITH VALUES IN THE UPPER 60 TO MID 70
PERCENT RANGE.
FOR TOMORROW, RH WILL NOT BE AS LOW AND WINDS WILL ARE NOT
EXPECTED TO BE AS STRONG, THUS REDUCING THE THREAT OF REACHING
CRITICAL FIRE WEATHER CONDITIONS.
THIS WILL BE THE GENERAL RULE FOR THE REMAINDER OF THE WEEK AS
HIGH PRESSURE BUILDS IN AND REMAINS IN CONTROL THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...CMG
AVIATION...CMG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
644 AM EDT WED APR 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY, BRINGING SUNNY SKIES LATER THIS
MORNING AND BREEZY CONDITIONS. HIGH PRESSURE WILL KEEP QUIET
WEATHER OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
IT IMAGERY AND GROUND OBS STILL SHOWING CLOUD COVER OVER MOST OF
THE CWA, WITH SOME CLEARING FROM THE NW. THIS CLEARING WILL SLOWLY
CONTINUE UNTIL AROUND DAY BREAK WHEN MIXING BEGINS TO CLEAR IT OUT
SOMEWHAT FASTER. THIS WILL ALLOW FOR SUNNY SKIES LATER THIS
MORNING AND THE REST OF THE DAY. AS HIGH PRESSURE BUILDS IN, THE
PRESSURE GRADIENT WILL INCREASE OVER THE CWA, ALLOWING FOR WINDS
TO INCREASE WITH GUSTS TO AROUND 20 MPH. RELATIVE HUMIDITY WILL BE
FAIRLY DRY TODAY, DROPPING TO AROUND 30 PERCENT. MODELS HAVE MORE
MOISTURE THAN THAT, BUT THINKING IS THEY ARE OVER DOING SFC
MOISTURE, SO HAVE LOWERED DEW POINTS INTO THE UPPER 20S TO LOW 30S
TODAY. THE HRRR SEEMS TO HAVE ONE OF THE BEST HANDLES ON THE RH
TODAY. IT DOES SHOW INCREASING RH FROM THE NW THIS MORNING, ONLY
TO FALL OFF LATE MORNING AND AFTERNOON AS MIXING OCCURS. EVEN WITH
THE LOWERING RH, IT STILL SHOWS RH VALUES IN THE 40 PERCENT RANGE.
SO, STARTING THERE AND TAKING ABOUT 10 PERCENT OFF OF THAT, STILL
KEEPS FIRE WEATHER CONCERNS MARGINAL AT BEST. NOT TO MENTION, THE
PRECIP CRITERIA HAS NOT BEEN MET FOR NY, AS MUCH OF THE CWA
RECEIVED OVER A QUARTER INCH OF RAIN ON SUNDAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE REMAINDER OF THE
WEEK. THIS WILL KEEP THE WEATHER QUIET. LOOKING AT TEMPS TONIGHT,
THEY WILL COOL TO THE LOWER 30S. THERE MAY BE SOME LOCALIZED AREAS
OF BELOW FREEZING TEMPS, BUT NOT EXPECTED TO BE WIDESPREAD AT THIS
TIME IN AREAS WHERE THE GROWING SEASON HAS STARTED. THUS, HAVE
OPTED NOT TO ISSUE ANY PRODUCTS AT THIS TIME.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
.0345 AM UPDATE... VERY FEW CHANGES MADE TO THE LONG TERM AS
PREVIOUS FORECAST HAD A GOOD HANDLE ON EXPECTED CONDITIONS. IN
GENERAL...DRY/SEASONAL CONDITIONS EXPECTED TOWARDS THE START OF
THE PERIOD WITH AN EVENTUAL SHIFT TOWARDS UNSETTLED CONDITIONS AND
BELOW NORMAL TEMPS EARLY NEXT WEEK AS AN UPPER VORTEX BECOMES
FIRMLY ESTABLISHED ACROSS EASTERN CANADA. BOTH GFS AND ECMWF
SHOWING SURPRISING AGREEMENT WITH THE EVOLUTION OF THIS
FEATURE...WITH BOTH AGREEING UPPER LOW WILL TAKE UP RESIDENCE
ACROSS THE UPPER ST. LAWRENCE VALLEY BY MONDAY.
UNFORTUNATELY...OUR REGION WILL BE EMBEDDED IN NORTHERLY FLOW TO
THE SYSTEM/S WEST WHICH WILL SET UP A FAVORABLE CORRIDOR FOR THE
PASSAGE OF UPPER SHORTWAVE DISTURBANCES ACROSS OUR REGION. BASED
ON FAVORABLE MODEL AGREEMENT...HAVE LOWERED DAYTIME HIGHS A FEW
DEGREES EACH DAY BEGINNING MON.
.PREVIOUS LONG TERM DISCUSSION...
THE LONG TERM STARTS OFF WITH HIGH PRESSURE IN CONTROL WITH FAIR
AND MAINLY CLEAR WX FOR FRI AND SAT AND MOST OF SUNDAY. LATER ON
SUNDAY...A WEAK FNTL SYSTEM MAY BRING AN INCREASE IN CLDS AND THE
CHC FOR A FEW -SHRA ON SUN NGT. AFTER THIS TIME MDLS ARE IN PRETTY
GOOD AGREEMENT THAT AN UPR TROF WILL BE AMPLIFYING OVER THE RGN
WITH A TREND TWDS COOLER AND WETTER CONDITIONS TAKING HOLD. WE
FOLLOWED HPC GDNC FOR THE MOST PART...BUT LOWERED MAXES A BIT FOR
EARLY NXT WEEK GIVEN MDL TRENDS AND LATEST MOS GDNC.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS TO START OUT THE TAF PERIOD THIS MORNING AS LOW
CLOUDS CONTINUE TO SLOWLY SLIDE SOUTH AND EAST OF THE REGION. BIG
CONCERNS FOR TODAY WILL BE INCREASING WINDS BEHIND A WEAK COLD
FRONT ALONG WITH INCREASING CLOUDS (POSSIBLE MVFR CIGS) THIS
AFTERNOON. FOR NOW BEST POTENTIAL FOR MVFR CIGS WILL BE AT
SYR/RME/ITH/BGM THIS AFTERNOON AFTER 18Z FOLLOWING FRONTAL
PASSAGE. CONDITIONS MAY TEMPORARILY IMPROVE NEAR 00Z THIS
EVENING...HOWEVER MODELS CONTINUE TO SUGGEST A RETURN OF MVFR CIGS
AFTER 06Z AS LOW-LEVEL MOISTURE LINGERS AROUND. THE ONLY TWO
LOCATIONS WHERE RESTRICTIONS ARE NOT EXPECTED AT THIS TIME INCLUDE
BOTH AVP AND ELM AS BOTH SITES WILL REMAIN ALONG THE SOUTHERN EDGE
OF THE DEVELOPING CLOUD SHIELD.
THE OTHER STORY WILL BE INCREASING NORTHWESTERLY WINDS AFTER 14Z
AS A STRONG PRESSURE GRADIENT REMAINS OVER THE AREA. EXPECT WIND
GUSTS OF NEAR 25 KTS ACROSS THE FINGER LAKES AND TWIN TIERS...WITH
GUSTS POSSIBLY APPROACHING 30 KTS AT BOTH SYR AND RME. WINDS WILL
DECREASE THIS EVENING AS THE PRESSURE GRADIENT BEGINS TO WEAKEN
WITH TIME.
.OUTLOOK...
THU THROUGH SUN...VFR.
&&
.FIRE WEATHER...
WHILE THERE IS A HIGH FIRE DANGER IN SOME AREAS, RED FLAG CRITERIA
LOOKS TO NOT BE MET, OR FAIRLY MARGINAL IN SOME AREAS. FOR THE NEW
YORK AREA, RAIN ON SUNDAY OF MORE THAN A QUARTER OF AN INCH OVER A
LARGE AREA, HAS KEPT THE CRITERIA FROM BEING MET. ALSO, RELATIVE
HUMIDITY WILL DROP TODAY. HOWEVER, IT DOES LOOK TO REMAIN IN THE
LOW 30 PERCENT RANGE IN THE CATSKILL AREA. ALSO, WINDS ARE
EXPECTED TO BE GUSTY TODAY, WITH SOME GUSTS APPROACHING 25 MPH,
AGAIN, ESPECIALLY IN THE CATSKILL REGION. THIS, WHEN COMBINED WITH
LOW FUEL MOISTURE, WOULD CAUSE BORDERLINE CONDITIONS, BUT NOT
EXPECTING EXPLOSIVE FIRE GROWTH POTENTIAL AT THIS TIME.
TEMPS WILL BE NEAR FREEZING OVER MUCH OF THE AREA TONIGHT. RH
RECOVERY WILL BE MODERATE, WITH VALUES IN THE UPPER 60 TO MID 70
PERCENT RANGE.
FOR TOMORROW, RH WILL NOT BE AS LOW AND WINDS WILL ARE NOT
EXPECTED TO BE AS STRONG, THUS REDUCING THE THREAT OF REACHING
CRITICAL FIRE WEATHER CONDITIONS.
THIS WILL BE THE GENERAL RULE FOR THE REMAINDER OF THE WEEK AS
HIGH PRESSURE BUILDS IN AND REMAINS IN CONTROL THROUGH THE WEEKEND.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI
NEAR TERM...SLI
SHORT TERM...SLI
LONG TERM...CMG
AVIATION...CMG
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 AM EDT WED APR 4 2012
.SYNOPSIS...
A STRONG BACK DOOR COLD FRONT WILL APPROACH FROM THE NORTH THIS
EVENING...THEN SURGE SOUTH THROUGH THE AREA LATE TONIGHT AND
THURSDAY MORNING. MUCH COOLER TEMPERATURES ARE EXPECTED IN THE WAKE
OF THE FRONT THURSDAY AND FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM WEDNESDAY...
A MODEST MID-LEVEL SHORTWAVE MOVING THROUGH CENTRAL NORTH CAROLINA
THIS MORNING HELPED TO INITIATE ISOLATED DEEP CONVECTION TOWARD KIXA
AND KRWI AROUND SUNRISE...WITH JUST ENOUGH ELEVATED INSTABILITY AND
STEEP LAPSE RATES NOTED AT LEAST ON FORECAST SOUNDINGS...SUCH AS THE
KFAY NAM BUFR SOUNDING FOR 12Z TODAY...TO PROVIDE FOR ISOLATED
SHOWERS AND THUNDERSTORMS. THE PRECIPITATION STARTED TO WANE DURING
THE MID-MORNING HOURS...AND THIS PRECIPITATION AND ITS EVOLUTION WAS
VERY WELL DEPICTED ON SOME OF THE 00Z WRF MODELS. WITH MSAS SHOWING
A RELATIVE MINIMUM OF SURFACE-BASED LIFTED INDICES AND THETA-E OVER
MUCH OF CENTRAL NORTH CAROLINA...AND IN SUBSIDENCE BEHIND THE
MID-LEVEL WAVE AS FORECAST BY BOTH THE LATEST RUC AND NAM...THERE
SHOULD BE LOW CHANCES FOR REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS
UNTIL LATER IN THE AFTERNOON. AT THAT POINT...BUFR SOUNDINGS FROM
THE NAM SHOW AVAILABLE INSTABILITY STARTING TO INCREASE...AS
LOW-LEVEL CIN IS OVERCOME AND LAPSE RATES ACTUALLY STEEPEN...TO AT
LEAST 7C/KM FROM 1000-500MB ON BOTH THE LATEST NAM AND RUC. WHILE
JET SUPPORT STAYS WELL TO THE NORTH IN THE MID- AND UPPER-LEVELS...
AND LOW-LEVEL WINDS ARE NOT FORECAST TO BE TOO STRONG...ONLY ABOUT
10-15 KNOTS FROM 925MB THROUGH 850MB WHICH IS COINCIDENT WITH SOME
OF THE LIGHTER WINDS ALOFT ON THE LATEST LOCAL AMDAR SOUNDINGS...
850MB CONVERGENCE INCREASES AND INVERTED-V-TYPE BUFR SOUNDINGS TAKE
SHAPE BY LATE IN THE AFTERNOON...CONTINUING INTO THE EVENING. WITH
THE FRONT TO THE NORTH AND SURFACE TROUGHINESS DEVELOPING TO THE
WEST DURING THE DAY...THE LIKELY SCENARIO IS THAT DEEPER CONVECTION
WILL DEVELOP TO OUR NORTH AND WEST AND MOVE SOUTHEAST ACROSS THE
AREA EITHER PROPAGATING OR REGENERATING OFF OF ITS COOL POOL. SOME
OF THE WRF GUIDANCE SUGGESTS MUCH OF THE PRECIPITATION STAYING NEAR
THE VIRGINIA BORDER AND NEAR OR WEST OF THE YADKIN RIVER THROUGH
LATE AFTERNOON...WHILE OTHERS SHOW A SURGE IN SHOWERS AND STORMS
MOVING SOUTHEAST ALONG AND SOUTH OF U.S. 64. WHILE LOCATION IS
UNCERTAIN...A LIKELY SCENARIO IS SOME DEVELOPMENT OF A CLUSTER OF
STORMS MOVING OVER SOME PART OF CENTRAL NORTH CAROLINA LATE TODAY
AND THIS EVENING WITH A POTENTIAL FOR DAMAGING WINDS. WET-BULB ZERO
VALUES ARE LOW...SO HAIL IS ALSO A THREAT. THE CURRENT HAZARDOUS
WEATHER OUTLOOK DISCUSSES THE TIMING AND PRIMARY THREAT OF DAMAGING
WINDS WELL.
HIGH TEMPERATURES SHOULD REACH THE MID 80S OVER MUCH OF CENTRAL
NORTH CAROLINA. THE AFTERNOON HIGH MAY COME CLOSE TO THE RECORD AT
KRDU...WHERE IT IS A COOL 87 DEGREES RELATIVE TO SURROUNDING DAYS.
THE KGSO RECORD IS 86...A LESSER CHANCE OF REACHING THAT ONE.
THOUGH INSTABILITY WILL BEGIN TO WANE AFTER SUNSET...ADDITIONAL
CONVECTION WILL BE POSSIBLE IN ASSOCIATION WITH THE BACK DOOR COLD
FRONT PROGRESSING SOUTH THROUGH VIRGINIA INTO CENTRAL NORTH CAROLINA
OVERNIGHT. WILL MAINTAIN A SLIGHT CHANCE (20%) NORTH TO LOW CHANCE
(30%) SOUTH FOR THE LATE NIGHT HOURS...WITH ISOLATED THUNDERSTORMS
MORE LIKELY IN SOUTHERN PORTIONS OF THE AREA. EXPECT LOWS TO RANGE
FROM THE LOWER/MID 50S IN THE NORTH AND NORTHEAST TO THE UPPER 50S
AND LOWER 60S IN THE SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 310 AM WEDNESDAY...
AN UPPER LOW CURRENTLY LIFTING OUT OF NORTHEAST NM WILL DRIFT EAST
ACROSS THE MID MS RIVER VALLEY WEDNESDAY NIGHT... AND THEN BEGIN TO
MOVE SOUTHEAST TOWARD AL/GA ON THURSDAY AS IT APPROACHES THE
SOUTHERN EDGE OF BROAD CYCLONIC FLOW OVER THE NORTHEAST US. A COLD
FRONT AND/OR REMNANT CONVECTIVE OUTFLOW SHOULD BE NEAR THE
NC/SC BORDER BY 12Z THURSDAY...WHERE A FEW ISOLATED SHOWERS CANNOT
BE RULED OUT DURING THE MORNING HOURS. HOWEVER...MOST OF THE
CENTRAL NC SHOULD BE DRY THROUGH THURSDAY AFTERNOON AS A SURFACE
HIGH PRESSURE RIDGE SETTLES IN BEHIND THE FRONT AND A WEAK SHORTWAVE
UPPER RIDGE SHIFTS ACROSS NC AHEAD OF THE APPROACHING UPPER LOW.
WHILE FORECAST SOUNDINGS SUGGEST THE BOUNDARY LAYER WILL BE SLOW TO
SATURATE UNTIL LATER THURSDAY EVENING...THE LOW
LEVEL COLD ADVECTION BEHIND THE FRONT SHOULD BE HELP TO LOCK IN
STRATUS AT 2-3K FT WHERE MOISTURE WILL ALREADY EXIST. THUS...TEMPS
WILL STRUGGLE TO RISE UNTO THE LOW TO MID 60S...A GOOD 20 DEGREES
COOLER THAN WEDNESDAY.
FORCING FOR ASCENT...IN THE FORM OF INCREASING DIVERGENCE
ALOFT...WEAK LOW LEVEL WARM ADVECTION AND 60-80M HEIGHT FALLS...WILL
ARRIVE THURSDAY EVENING AS THE UPPER LOW DIVES THROUGH AL/GA. WHILE
THERE HAS BEEN GOOD MODEL CONSISTENCY IS THE GENERAL TRACK OF THE
UPPER AND SURFACE LOWS...THERE ARE STILL 100-200 MILE DIFFERENCES
THAT WILL IMPACT HOW FAR NORTH INTO NC BETTER RAIN COVERAGE WILL
EXTEND. MOST OF THE SHOWERS WILL PASS TO OUR SOUTH THURSDAY NIGHT
AS THE SURFACE LOW DEVELOPS AND MOVES TO NEAR SAVANNAH BY 06-12Z
FRIDAY. HOWEVER...A SHORTWAVE DROPPING SOUTH OUT OF EASTERN CANADA
INTO THE MID-ATLANTIC STATES SHOULD HELP DRAW MOISTURE NORTH INTO
THE VICINITY OF THE 925-850MB FRONT WHICH IS FORECAST TO LIE ACROSS
THE CAROLINAS. MODELS HAVE BEEN SHOWING AN AREA OF INCREASE LOW
LEVEL FGEN DEVELOPING OVER NC LATER FRIDAY NIGHT...SO WHILE THE BEST
SURFACE CONVERGENCE AND UPPER FORCING WILL BE JUST TO OUR SOUTH...WE
SHOULD SEE PRECIP EXPAND AND INTENSIFY NORTHWARD ACROSS SOUTHERN AND
EASTERN NC OVERNIGHT. WE DO NOT EXPECT ANY CONVECTION THURSDAY
NIGHT AS LOW LEVELS WILL BE STABLE...MID LEVEL LAPSE RATES WILL BE
WEAK... AND THE STRONGEST UPPER FORCING WILL BE TO OUR SOUTH.
HOWEVER...IF THE SURFACE LOW TRACKS SLIGHTLY NORTH OF THE CURRENT
FORECAST...THERE COULD BE ENOUGH INSTABILITY ACROSS THE SOUTHERN
PIEDMONT AND SANDHILLS TO SUPPORT A FEW ISOLATED THUNDERSTORMS.
FORECAST POPS ARE ALREADY HIGH ACROSS THE SOUTH AFTER 21Z
THURSDAY...EXPANDING NORTHWARD AFTER 03Z...WHICH SEEMS SUFFICIENT
FOR THE CURRENT FORECAST PACKAGE. LOWS IN THE UPPER 40S.
THE SURFACE LOW SHOULD BE OFF THE SC COAST BY 12Z FRIDAY..WITH
PRECIP ENDING FROM WEST TO EAST DURING THE DAY. THE MSLP GRADIENT
ON THE BACK SIDE OF THE SURFACE LOW WILL BE FAIRLY TIGHT...WITH MOST
MODELS SHOWING A 15-20KT NORTHEASTERLY WIND OVER THE COASTAL PLAIN
FRIDAY MORNING. THE DEPARTING LOW WILL ALSO DRAW DRIER AIR IN FROM
THE NORTH AS WINDS BEGIN TO TURN TO NORTH-NORTHWESTERLY FRIDAY
AFTERNOON. FORECAST SOUNDINGS NOW SHOW MOST OF THE CENTRAL BREAKING
OUT FRIDAY...ALTHOUGH MODELS OFTEN HAVE A TENDENCY TO SCOUR LOW
LEVEL MOISTURE TOO QUICKLY IN THE ABSENCE OF A FRONTAL SYSTEM.
BECAUSE OF THIS...THE HIGH TEMP FORECAST FOR FRIDAY IS SOMEWHAT
UNCERTAIN...BUT IT IS POSSIBLE THAT AREA SIN THE WEST COULD BREAK
OUT AND BE AS WARM IF NOT WARMER THAN AREAS IN THE EAST. WILL
FORECAST HIGHS GENERALLY AROUND 60.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 350 AM WEDNESDAY...
HIGH PRESSURE OVER THE GREAT LAKES WILL BRIEFLY BUILD SOUTH ACROSS
MUCH OF THE EASTERN US THIS WEEKEND...WHILE SEVERAL SHORTWAVES OVER
EASTERN CANADA AND THE NORTHERN US WRAP UP OVER NEW ENGLAND AND LEAD
TO A DEEP TROUGH ALONG THE EAST COAST NEXT WEEK. RAIN CHANCES
APPEAR TO BE LOW BUT ALSO LESS PREDICTABLE DUE TO THE NORTHWESTERLY
FLOW REGIME...ESPECIALLY FROM SUNDAY NIGHT ONWARD. HIGHS WARMING
INTO THE LOW TO MID 70S BY SUNDAY WILL DROP BACK INTO THE 60S FOR
THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 1000 AM WEDNESDAY...
24-HR TAF PERIOD:
EXPECT VFR CONDITIONS TO PREDOMINATE THROUGH 18Z THIS AFTERNOON IN
ASSOC/W SUBSIDENCE IN THE WAKE OF AN UPPER LEVEL DISTURBANCE EXITING
TO THE EAST. BY MID TO LATE AFTERNOON...EARLIER TOWARD THE TRIAD...
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO BE POSSIBLE AT TAF
SITES IN ADVANCE OF A STRONG BACK DOOR COLD FRONT APPROACHING FROM
THE NORTH...WITH SHOWERS/STORMS PERSISTING IN SOME AREAS THROUGH THE
END OF THE TAF PERIOD. WINDS WILL BE WEST OR SW AT 5-10 KT THROUGH
00Z THIS EVENING...BECOMING NORTH AND EVENTUALLY NORTHEAST AT 10-15
KT BY OR SHORTLY AFTER 12Z THU MORNING.
LOOKING AHEAD:
BREEZY NORTHEAST WINDS (10-15 KT GUSTING TO 20 KT) CAN BE EXPECTED
IN THE WAKE OF THE BACK DOOR COLD FRONTAL PASSAGE BETWEEN 09-18Z
THURSDAY...ALONG WITH OVERCAST CEILINGS BETWEEN 3000-4500 FT AGL.
AFTER 18Z THU...MVFR CONDITIONS AND LIGHT RAIN ARE EXPECTED IN
ASSOC/W A DEVELOPING LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST.
IFR CONDITIONS WILL BE POSSIBLE...PRIMARILY LATE THU EVENING INTO
THU NIGHT. MVFR/IFR CEILINGS ARE EXPECTED TO LIFT AND SCATTER OUT
BETWEEN 12-18Z FRIDAY IN ASSOC/W DRY AIR ADVECTING INTO THE AREA VIA
BREEZY NNE FLOW. VFR CONDITIONS ARE EXPECTED TO PERSIST FROM EARLY
FRIDAY AFTERNOON INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...DJF/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
642 AM EDT WED APR 4 2012
.SYNOPSIS...
A STRONG BACK DOOR COLD FRONT WILL APPROACH FROM THE NORTH THIS
EVENING AND SURGE SOUTHWARD THROUGH THE AREA LATE TONIGHT AND
THURSDAY MORNING.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 315 AM WEDNESDAY...
OVERVIEW:
THE HEIGHT GRADIENT ALOFT WILL TIGHTEN OVER THE CAROLINAS AND
MID-ATLANTIC TODAY IN ASSOC/W MODEST HEIGHT FALLS IN ADVANCE OF AN
H5 TROUGH PROGRESSING SLOWLY S/SE FROM CANADA INTO THE LOWER GREAT
LAKES AND NEW ENGLAND. ALTHOUGH DPVA WITH THE AFOREMENTIONED TROUGH
WILL REMAIN WELL NORTH IN NEW ENGLAND...STRENGTHENING WESTERLY FLOW
ALOFT WILL RESULT IN A POTENTIAL FOR DPVA IN THE FORM OF MINOR
SHORTWAVES/MCVS ADVECTING INTO NC/VA FROM THE WEST THIS AFTERNOON
INTO TONIGHT. IN ADDITION TO AN MCV NOTED OVER CENTRAL NC (VIA
LATEST RUC DATA) AT 06Z...SEVERAL MCVS/DISTURBANCES WERE NOTED
UPSTREAM OVER THE CENTRAL/LOWER MS RIVER VALLEY THIS MORNING. IN THE
LOWER LEVELS...THE WARM FRONT PROGRESSING NORTH THROUGH SOUTHERN VA
AS OF 06Z WILL STALL OUT IN NORTHERN VA TODAY...THEN RETREAT
SOUTHWARD AS A BACK DOOR COLD FRONT THIS AFTERNOON AND
EVENING...WITH A PRE-FRONTAL TROUGH PROGRESSING INTO CENTRAL NC BY
18-21Z. THE COLD FRONT WILL PROGRESS SOUTH THROUGH CENTRAL NC LATE
TONIGHT/THU MORNING.
PRECIPITATION CHANCES:
THOUGH STEEP MID-LEVEL LAPSE RATES (7-8 C/KM) WERE PRESENT OVER
NC/VA AND THE OH VALLEY AT 06Z THIS MORNING...MODEL GUIDANCE
CONTINUES TO INDICATE LAPSE RATES WEAKENING TO 5.5-6 C/KM BETWEEN
18-00Z. HOWEVER...AN UNSEASONABLY WARM/MOIST AIRMASS WILL BE IN
PLACE ACROSS CENTRAL NC TODAY...AND THIS SHOULD ALLOW FOR 500-1000
J/KG OF MLCAPE DURING PEAK HEATING...PERHAPS 1000-1500 J/KG IF
MID-LEVEL LAPSE RATES REMAIN NEAR OR SLIGHTLY ABOVE 6 C/KM...
PRIMARILY BETWEEN 18-21Z. GIVEN A LOW-LEVEL FOCUS (PRE-FRONTAL
TROUGH) AND A POTENTIAL FOR DISTURBANCES ALOFT ADVECTING INTO THE
AREA FROM THE WEST IN THE PRESENCE OF MARGINAL TO MODERATE
INSTABILITY...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP
BETWEEN 18-21Z THIS AFTERNOON. HOWEVER...UNCERTAINTY IN THE TIMING
AND LOCATION OF CONVECTION PERSISTS...PRIMARILY IN ASSOCIATION WITH
THE TRACK/EVOLUTION OF UPSTREAM DISTURBANCES ADVECTING TOWARD NC/VA
VIA STRENGTHENING WESTERLY FLOW ALOFT. THE LATEST 00Z WRF-NMM
INDICATES DRY CONDITIONS THROUGH 18Z...SHOWING ISOLD/SCT CONVECTION
DEVELOPING OVER THE MOUNTAINS AND MOVING DOWNSTREAM INTO THE CENTRAL
NC BY 21Z THIS AFTERNOON...WITH ADDITIONAL CONVECTION DEVELOPING IN
VICINITY OF THE PRE-FRONTAL TROUGH OVER CENTRAL NC. THE 00Z WRF-ARW
SHOWS SCATTERED CONVECTION DEVELOPING OVER CENTRAL NC PRIMARILY IN
ASSOC/W THE PRE-FRONTAL TROUGH BETWEEN 18-21Z. AT THIS TIME WILL NOT
CHANGE PRECIP CHANCES MUCH FROM THE PREVIOUS FORECAST...SHOWING A
40% CHANCE FOR SHOWERS/STORMS...WITH THE BEST CHANCE BETWEEN 19Z
THIS AFTERNOON AND 01Z THIS EVENING. THOUGH INSTABILITY WILL BEGIN
TO WANE AFTER SUNSET...ADDITIONAL CONVECTION WILL BE POSSIBLE IN
ASSOC/W THE BACK DOOR COLD FRONT PROGRESSING SOUTH THROUGH VA INTO
CENTRAL NC OVERNIGHT. HOWEVER...THIS MAY DEPEND ON HOW MUCH
STABILIZATION OCCURS IN ASSOC/W CONVECTION DURING THE AFTERNOON AND
EVENING. WILL MAINTAIN A SLIGHT CHANCE (20%) NORTH TO LOW CHANCE
(30%) SOUTH OVERNIGHT...WITH ISOLD THUNDERSTORMS MORE LIKELY IN
SOUTHERN PORTIONS OF THE AREA.
TEMPERATURES:
1000-850 MB THICKNESSES ARE PROGGED AT 1390-1400 METERS THIS
AFTERNOON. THESE THICKNESSES SUPPORT HIGHS IN THE LOWER/MID 80S...
OR 82-85F. ALTHOUGH A FAIR AMOUNT OF MID/UPPER LEVEL CLOUD COVER IS
PRESENT THIS MORNING...EXPECT A REASONABLE POTENTIAL FOR SOME
CLEARING AND ENOUGH SUNSHINE FOR TEMPS TO REACH THE LOWER/MID 80S.
LOWS TONIGHT WILL DEPEND ENTIRELY ON THE TIMING/PROGRESS OF THE BACK
DOOR COLD FRONT SURGING SOUTH INTO THE AREA. AT THIS TIME...EXPECT
LOWS TO RANGE FROM THE LOWER/MID 50S IN THE NORTH/NE TO THE UPPER
50S AND LOWER 60S IN THE SOUTH.
SEVERE THREAT:
THE SPC DAY 1 OUTLOOK INDICATES A SLIGHT RISK OF SEVERE STORMS TODAY
OVER MOST OF CENTRAL NC. AS WESTERLY FLOW ALOFT STRENGTHENS...0-6 KM
BULK SHEAR VALUES IN CENTRAL NC ARE EXPECTED TO INCREASE TO 25-35 KT
THIS AFT/EVE...FURTHER INCREASING TO 30-40 KT AFTER 00Z. 0-6KM BULK
SHEAR VALUES WILL CERTAINLY BE SUPPORTIVE OF MULTICELL
ORGANIZATION...AND MAY BE AT THE LOW-END THRESHOLD FOR SUPERCELLULAR
ORGANIZATION...PRIMARILY AFTER 00Z...OR IF THE HEIGHT GRADIENT ALOFT
TIGHTENS/MID-LEVEL FLOW ACCELERATES IN ADVANCE OF AN UPPER LEVEL
DISTURBANCE PROGRESSING INTO THE AREA THIS AFT/EVE (SHOULD THAT
OCCUR). STEEP LOW-LEVEL LAPSE RATES ASSOC/W STRONG DIURNAL HEATING
WILL CONTRIBUTE TO RELATIVELY HIGH DCAPE AND THE POTENTIAL FOR
STRONG COLD POOLS THIS AFT/EVE. WITH THE ABOVE IN MIND...EXPECT THE
BEST CHANCE FOR SEVERE WEATHER FROM 3-10 PM...WITH A PRIMARY THREAT
OF DAMAGING WINDS OWING TO STEEP LOW-LEVEL LAPSE RATES AND
RELATIVELY SPEEDY MID-LEVEL FLOW. SEVERE HAIL APPEARS LESS LIKELY
GIVEN WEAK MID-LEVEL LAPSE RATES AND BULK SHEAR VALUES ON THE
LOW-END OF/OR UNSUPPORTIVE OF ROTATING UPDRAFTS. GIVEN STRONG
HEATING AND STEEP LOW-LEVEL LAPSE RATES...IF CONVECTION INITIATES ON
THE HIGHER TERRAIN AND PROGRESSES EAST INTO THE WESTERN PIEDMONT
DURING THE MID/LATE AFTERNOON...A LINE OF STORMS (ORGANIZING ALONG
OUTFLOW) COULD DEVELOP AND POSE A THREAT FOR RELATIVELY WIDESPREAD
DAMAGING WINDS. -VINCENT
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 310 AM WEDNESDAY...
AN UPPER LOW CURRENTLY LIFTING OUT OF NORTHEAST NM WILL DRIFT EAST
ACROSS THE MID MS RIVER VALLEY WEDNESDAY NIGHT... AND THEN BEGIN TO
MOVE SOUTHEAST TOWARD AL/GA ON THURSDAY AS IT APPROACHES THE
SOUTHERN EDGE OF BROAD CYCLONIC FLOW OVER THE NORTHEAST US. A COLD
FRONT AND/OR REMNANT CONVECTIVE OUTFLOW SHOULD BE NEAR THE
NC/SC BORDER BY 12Z THURSDAY...WHERE A FEW ISOLATED SHOWERS CANNOT
BE RULED OUT DURING THE MORNING HOURS. HOWEVER...MOST OF THE
CENTRAL NC SHOULD BE DRY THROUGH THURSDAY AFTERNOON AS A SURFACE
HIGH PRESSURE RIDGE SETTLES IN BEHIND THE FRONT AND A WEAK SHORTWAVE
UPPER RIDGE SHIFTS ACROSS NC AHEAD OF THE APPROACHING UPPER LOW.
WHILE FORECAST SOUNDINGS SUGGEST THE BOUNDARY LAYER WILL BE SLOW TO
SATURATE UNTIL LATER THURSDAY EVENING...THE LOW
LEVEL COLD ADVECTION BEHIND THE FRONT SHOULD BE HELP TO LOCK IN
STRATUS AT 2-3K FT WHERE MOISTURE WILL ALREADY EXIST. THUS...TEMPS
WILL STRUGGLE TO RISE UNTO THE LOW TO MID 60S...A GOOD 20 DEGREES
COOLER THAN WEDNESDAY.
FORCING FOR ASCENT...IN THE FORM OF INCREASING DIVERGENCE
ALOFT...WEAK LOW LEVEL WARM ADVECTION AND 60-80M HEIGHT FALLS...WILL
ARRIVE THURSDAY EVENING AS THE UPPER LOW DIVES THROUGH AL/GA. WHILE
THERE HAS BEEN GOOD MODEL CONSISTENCY IS THE GENERAL TRACK OF THE
UPPER AND SURFACE LOWS...THERE ARE STILL 100-200 MILE DIFFERENCES
THAT WILL IMPACT HOW FAR NORTH INTO NC BETTER RAIN COVERAGE WILL
EXTEND. MOST OF THE SHOWERS WILL PASS TO OUR SOUTH THURSDAY NIGHT
AS THE SURFACE LOW DEVELOPS AND MOVES TO NEAR SAVANNAH BY 06-12Z
FRIDAY. HOWEVER...A SHORTWAVE DROPPING SOUTH OUT OF EASTERN CANADA
INTO THE MID-ATLANTIC STATES SHOULD HELP DRAW MOISTURE NORTH INTO
THE VICINITY OF THE 925-850MB FRONT WHICH IS FORECAST TO LIE ACROSS
THE CAROLINAS. MODELS HAVE BEEN SHOWING AN AREA OF INCREASE LOW
LEVEL FGEN DEVELOPING OVER NC LATER FRIDAY NIGHT...SO WHILE THE BEST
SURFACE CONVERGENCE AND UPPER FORCING WILL BE JUST TO OUR SOUTH...WE
SHOULD SEE PRECIP EXPAND AND INTENSIFY NORTHWARD ACROSS SOUTHERN AND
EASTERN NC OVERNIGHT. WE DO NOT EXPECT ANY CONVECTION THURSDAY
NIGHT AS LOW LEVELS WILL BE STABLE...MID LEVEL LAPSE RATES WILL BE
WEAK... AND THE STRONGEST UPPER FORCING WILL BE TO OUR SOUTH.
HOWEVER...IF THE SURFACE LOW TRACKS SLIGHTLY NORTH OF THE CURRENT
FORECAST...THERE COULD BE ENOUGH INSTABILITY ACROSS THE SOUTHERN
PIEDMONT AND SANDHILLS TO SUPPORT A FEW ISOLATED THUNDERSTORMS.
FORECAST POPS ARE ALREADY HIGH ACROSS THE SOUTH AFTER 21Z
THURSDAY...EXPANDING NORTHWARD AFTER 03Z...WHICH SEEMS SUFFICIENT
FOR THE CURRENT FORECAST PACKAGE. LOWS IN THE UPPER 40S.
THE SURFACE LOW SHOULD BE OFF THE SC COAST BY 12Z FRIDAY..WITH
PRECIP ENDING FROM WEST TO EAST DURING THE DAY. THE MSLP GRADIENT
ON THE BACK SIDE OF THE SURFACE LOW WILL BE FAIRLY TIGHT...WITH MOST
MODELS SHOWING A 15-20KT NORTHEASTERLY WIND OVER THE COASTAL PLAIN
FRIDAY MORNING. THE DEPARTING LOW WILL ALSO DRAW DRIER AIR IN FROM
THE NORTH AS WINDS BEGIN TO TURN TO NORTH-NORTHWESTERLY FRIDAY
AFTERNOON. FORECAST SOUNDINGS NOW SHOW MOST OF THE CENTRAL BREAKING
OUT FRIDAY...ALTHOUGH MODELS OFTEN HAVE A TENDENCY TO SCOUR LOW
LEVEL MOISTURE TOO QUICKLY IN THE ABSENCE OF A FRONTAL SYSTEM.
BECAUSE OF THIS...THE HIGH TEMP FORECAST FOR FRIDAY IS SOMEWHAT
UNCERTAIN...BUT IT IS POSSIBLE THAT AREA SIN THE WEST COULD BREAK
OUT AND BE AS WARM IF NOT WARMER THAN AREAS IN THE EAST. WILL
FORECAST HIGHS GENERALLY AROUND 60.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 350 AM WEDNESDAY...
HIGH PRESSURE OVER THE GREAT LAKES WILL BRIEFLY BUILD SOUTH ACROSS
MUCH OF THE EASTERN US THIS WEEKEND...WHILE SEVERAL SHORTWAVES OVER
EASTERN CANADA AND THE NORTHERN US WRAP UP OVER NEW ENGLAND AND LEAD
TO A DEEP TROUGH ALONG THE EAST COAST NEXT WEEK. RAIN CHANCES
APPEAR TO BE LOW BUT ALSO LESS PREDICTABLE DUE TO THE NORTHWESTERLY
FLOW REGIME...ESPECIALLY FROM SUNDAY NIGHT ONWARD. HIGHS WARMING
INTO THE LOW TO MID 70S BY SUNDAY WILL DROP BACK INTO THE 60S FOR
THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 640 AM WEDNESDAY...
24-HR TAF PERIOD:
ASIDE FROM A BRIEF POTENTIAL FOR MVFR/IFR CEILINGS PRIOR TO ~13Z...
EXPECT VFR CONDITIONS TO PREDOMINATE THROUGH 18Z THIS AFTERNOON IN
ASSOC/W SUBSIDENCE IN THE WAKE OF AN UPPER LEVEL DISTURBANCE EXITING
TO THE EAST. BY MID TO LATE AFTERNOON...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS TO BE POSSIBLE AT ALL TAF SITES IN ADVANCE OF A STRONG
BACK DOOR COLD FRONT APPROACHING FROM THE NORTH...WITH SHOWERS/
STORMS PERSISTING IN SOME AREAS THROUGH THE END OF THE TAF PERIOD.
WINDS WILL BE WEST OR SW AT 5-10 KT THROUGH 00Z THIS EVENING...
BECOMING NORTH AND EVENTUALLY NORTHEAST AT 10-15 KT BY OR SHORTLY
AFTER 12Z THU MORNING.
LOOKING AHEAD:
BREEZY NORTHEAST WINDS (10-15 KT GUSTING TO 20 KT) CAN BE EXPECTED
IN THE WAKE OF THE BACK DOOR COLD FRONTAL PASSAGE BETWEEN 09-18Z
THURSDAY...ALONG WITH OVERCAST CEILINGS BETWEEN 3000-4500 FT AGL.
AFTER 18Z THU...MVFR CONDITIONS AND LIGHT RAIN ARE EXPECTED IN
ASSOC/W A DEVELOPING LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST.
IFR CONDITIONS WILL BE POSSIBLE...PRIMARILY LATE THU EVENING INTO
THU NIGHT. MVFR/IFR CEILINGS ARE EXPECTED TO LIFT AND SCATTER OUT
BETWEEN 12-18Z FRIDAY IN ASSOC/W DRY AIR ADVECTING INTO THE AREA VIA
BREEZY NNE FLOW. VFR CONDITIONS ARE EXPECTED TO PERSIST FROM EARLY
FRIDAY AFTERNOON INTO THE WEEKEND. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1251 PM CDT WED APR 4 2012
.AVIATION...
THE UPPER LOW IS STILL OVER THE TEXAS PANHANDLE. THE SURFACE LOW
IS OVER SOUTHERN MISSOURI WITH A COLD FRONT STRETCHING BACK TO THE
SOUTHWEST. DRIER AIR IS STARTING TO MOVE INTO WESTERN ARKANSAS
NOW. ONLY ISOLATED SHOWERS OR THUNDERSTORMS ARE EXPECTED TO
DEVELOP IN THE FAR NORTH OR EAST. AREAS OF STRATOCUMULUS CONTINUE
ACROSS ARKANSAS AND WILL KEEP SOME MVFR CONDITIONS GOING FOR THESE
LOWER CLOUDS. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE
REST OF THE PERIOD. THE COLD FRONT WILL BE EAST OF THE MISSISSIPPI
RIVER BY 12Z THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT WED APR 4 2012/
AVIATION...
CONDITIONS SHOULD REMAIN LARGELY VFR FOR ALL TAF SITES. THE
EXCEPTION MAY BE KHOT AND KM89 FOR A BRIEF PERIOD THIS
MORNING...AND ALSO ANY TAF SITES AFFECTED BY SHOWERS LATER THIS
MORNING. DEWPOINT DEPRESSIONS ARE VERY SMALL AT THOSE SITES AND
KHOT IS SHOWING FEW-SCT003 BASES. THEY ARE RIGHT ON THE CUSP OF
DEVELOPING SOME FOG OR LOW CLOUDS SO HAVE THROWN A TEMPO FOR 4SM
AND SCT003 AT THOSE TWO TERMINALS. OTHERWISE...HAVE TRENDED
TOWARDS RUC GUIDANCE WHICH SHOWS SHOWERS DEVELOPING FROM ROUGHLY
KFYV DOWN TO KELD BEFORE 14Z...THEN SHIFTING EAST OF ALL TERMINALS
BY 18Z OR SO. NOT TERRIBLY CONFIDENT IN HOW MUCH REDEVELOPMENT OF
SHOWER ACTIVITY WE ARE GOING TO SEE TODAY SO ONLY INCLUDED MENTION
OF VCSH AT TERMINALS FOR A SHORT PERIOD THIS MORNING. WINDS WILL
GRADUALLY TURN WSW THROUGH THE DAY AS THE FRONT PASSES THROUGH.
LOOKS LIKE THERE SHOULD BE ENOUGH DRY AIR TO PRECLUDED FOG OR LOW
CLOUDS TONIGHT.
PREV DISCUSSION... /ISSUED 333 AM CDT WED APR 4 2012/
SHORT RANGE...TODAY THROUGH SATURDAY NIGHT
MODELS REMAIN IN BASICALLY GOOD AGREEMENT THIS MORNING DEPICTING A
SLOW MOVING UPPER LOW AND ASSOCIATED FRONTAL BOUNDARY MOVING ACROSS
THE FORECAST AREA. GFS/ECMWF COMBO PREFERRED THIS MORNING WITH NAM
SOLUTION INITIATING POORLY AND AS SUCH DISCOUNTED.
CLOSED OFF UPPER LOW OVER THE TEXAS/OKLAHOMA PANHANDLES SHOWING UP
CLEARLY ON MOISTURE CHANNEL IMAGERY THIS MORNING. SYSTEM REMAINS CUT
OFF FROM THE PREVAILING FLOW AND WILL DRIFT SLOWLY EASTWARD ACROSS
THE NORTHERN PART OF THE STATE OVER THE NEXT DAY OR SO...AND NOT
EXPECTED TO CLEAR THE STATE UNTIL THURSDAY AFTERNOON. ASSOCIATED
SURFACE BOUNDARY CURRENTLY OVER EASTERN OKLAHOMA AND ALSO EXPECTED
TO TAKE ITS TIME GETTING THROUGH THE STATE...LIKELY NOT CLEARING THE
MISSISSIPPI RIVER UNTIL LATE WEDNESDAY NIGHT/EARLY THURSDAY MORNING.
UPPER IMPULSE MOVING THROUGH THE REGION THIS MORNING CONTINUES TO
PRODUCE SCATTERED SHOWERS BUT OVERALL AREA CONTINUES TO DECREASE IN
AREAL COVERAGE. STRONGEST CONVECTION REMAINS TO THE SOUTH OF THE
FORECAST AREA BUT ISOLATED THUNDER CANNOT BE RULED OUT THIS MORNING
ESPECIALLY ACROSS THE SOUTHERN COUNTIES.
NEXT IMPULSE WILL MOVE THROUGH THE BASE OF THE UPPER LOW DURING THE
AFTERNOON. JET DYNAMICS ASSOCIATED WITH THE WAVE WILL LIKELY LEAD TO
ADDITIONAL CONVECTIVE DEVELOPMENT ALONG AND TO THE EAST OF THE
AFOREMENTIONED SURFACE BOUNDARY WHICH SHOULD LIKELY BE OVER THE
EASTERN THIRD OF THE FORECAST AREA. CAN NOT RULE OUT SOME STRONGER
STORMS OVER THIS AREA. PRECIPITATION CHANCES WILL BE LESS FURTHER TO
THE EAST AS DRIER AIR MOVES IN.
UPPER LOW MOVES ACROSS THE NORTH TONIGHT AND THURSDAY WITH ANOTHER
IMPULSE ROTATING THROUGH ITS BASE. THE RESULT WILL BE ANOTHER CHANCE
OF SCATTERED SHOWERS AND A FEW THUNDERSTORMS WITH THE BEST CHANCES
OVER THE NORTH CLOSER TO THE UPPER LOW. SYSTEM FINALLY CLEARS THE
STATE BY THURSDAY EVENING WITH HIGH PRESSURE BUILDING IN BEHIND THE
DEPARTING LOW WITH DRY CONDITIONS EXPECTED FRIDAY.
NEXT COLD FRONT WILL APPROACH THE STATE DURING THE DAY SATURDAY. GFS
KEEPS AREA DRY BUT ECMWF DOES PAINT A LITTLE QPF OVER THE NORTHWEST
ZONES LATE IN THE DAY. OVERALL SPEED OF THE FRONT A LITTLE SLOWER
AND WILL TRIM BACK POPS TO THE NORTHWEST SATURDAY AND AREA WIDE
SATURDAY NIGHT AS BOUNDARY WILL BE BISECTING THE STATE FROM
NORTHEAST TO SOUTHWEST BY THE END OF THE PERIOD. REGARDLESS...POPS
WILL ONLY BE SLIGHT CHANCE TO LOW END CHANCE AS SYSTEM NOT VERY
IMPRESSIVE.
TEMPERATURES WILL BE TRICKY TODAY DEPENDING ON WHERE THE FRONT ENDS
UP ALONG WITH PRECIP AND CLOUD COVER COMING INTO PLAY. WARMEST DAY
STILL LOOKS TO BE TODAY WITH TEMPERATURES RETURNING TO NEAR NORMAL
FOR THE REMAINDER OF THE PERIOD. MAV/MEX NUMBERS LOOK REASONABLE AND
ARE GENERALLY ACCEPTED.
LONG TERM...SUNDAY THROUGH TUESDAY...
A COLD FRONT WILL SWEEP THROUGH THE STATE ON SUNDAY AS AN UPPER
RIDGE BUILDS OVER THE HIGH PLAINS AND A TROUGH OVER THE EASTERN
CONUS. REALLY DO NOT EXPECT MUCH IN THE WAY OF PRECIP AS RETURN FLOW
WILL BE WEAK OR NON-EXISTENT IN THE DAYS LEADING UP TO SUN...AND
UPPER SUPPORT SHOULD BE WELL REMOVED TO THE NORTH. THE COLD FRONT
WILL STALL OUT TO THE SOUTH AND WEST OF THE STATE LATER IN THE
PERIOD. PREVIOUS SHIFTS HAD SOME SLIGHT CHANCE POPS...MAINLY IN THE
SOUTHWEST...ON MONDAY. WILL LEAVE THIS AS-IS DUE TO SHORTWAVE ENERGY
ROTATING THROUGH EITHER NEAR ARKANSAS...OR OVERHEAD DEPENDING ON
WHICH MODEL YOU BELIEVE. DID REMOVE PRECIP MENTION ON MONDAY NIGHT
THOUGH AS LOSS OF DAYTIME HEATING AND WHAT MARGINAL UPPER SUPPORT
WAS PRESENT SHOULD MEAN ANY SHOWER WOULD DIE A QUICK DEATH. AS FOR
TEMPERATURES...THEY WILL BE MUCH CLOSER TO NORMAL VALUES VERSUS WHAT
HAS BEEN SEEN LATELY. HIGHS FROM THE LOW 70S NORTH TO THE MID/UPPER
70S IN THE SOUTH WILL BE THE NORM. LOWS WILL BE IN THE LOW TO MID
50S INITIALLY...PERHAPS DIPPING INTO THE UPPER 30S TO LOW 40S IN THE
NORTH BY MONDAY/TUESDAY NIGHTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 55 73 48 71 / 30 40 10 0
CAMDEN AR 54 78 53 73 / 20 20 10 0
HARRISON AR 52 72 46 70 / 30 40 10 0
HOT SPRINGS AR 54 75 53 72 / 20 30 10 0
LITTLE ROCK AR 55 76 53 72 / 30 30 10 0
MONTICELLO AR 56 79 54 73 / 30 20 10 0
MOUNT IDA AR 53 75 52 72 / 20 30 10 0
MOUNTAIN HOME AR 53 72 47 70 / 40 40 10 0
NEWPORT AR 55 74 49 71 / 30 40 10 0
PINE BLUFF AR 56 78 54 73 / 30 30 10 0
RUSSELLVILLE AR 53 74 50 71 / 30 30 10 0
SEARCY AR 55 75 50 71 / 30 30 10 0
STUTTGART AR 56 77 53 72 / 30 30 10 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...51
AREA FORECAST DISCUSSION
NWS MELBOURNE
300 PM EDT WED APR 4 2012
.DISCUSSION...
...INCREASING CHANCE FOR STORMS LATE TOMORROW AND TOMORROW NIGHT...
...TURNING COOLER STARTING LATE FRIDAY...
CURRENT-TONIGHT...SURFACE RIDGE AXIS LOCATED OVER THE NORTH BAHAMAS
THE FLORIDA STRAITS AND INTO THE SOUTHEAST GULF OF MEXICO. LOW
PRESSURE SYSTEM MOVING EAST ACROSS THE NORTH GULF OF MEXICO AND THE
GULF COAST. LATEST RUC 500MB ANALYSIS PLACES STRONG NEGATIVE
VORTICITY ADVECTION (NVA) AHEAD OF THE COMPLEX AND STRONGER POSITIVE
VORTICITY ADVECTION (PVA) BEHIND THE SYSTEM. FLAT FLOW ALOFT WILL
ALLOW THE UPPER LOW TO MOVE QUICKLY EAST AND OVER NORTHERN AREAS
THIS EVENING. MORNING SOUNDINGS INDICATED COLD 500MB
TEMPERATURES...-12C TO -14C RANGE...MOVING OVERHEAD THE SAME TIME
THE VORTICITY MAXES CROSS OVERTOP NORTHERN COUNTIES. ALTHOUGH THE
LATEST WEATHER ROUNDUP WAS INDICATING DEW POINTS MAINLY IN THE 50S
IF ANY CELL DOES MANAGE TO DEVELOP ANY VERTICAL EXTENT IT WILL BE
QUICKLY PUNCHING INTO EVEN DRIER AIR AND EVENTUALLY THE COLD
TEMPERATURES ALOFT. IT COULD BE JUST A COUPLE OF STORMS THAT HAVE
THE POTENTIAL TO BECOME STRONG ENOUGH TO PRODUCE STRONG DOWNBURSTS
AND HAIL. ONCE THE SUN SETS AND THE ATMOSPHERE STABILIZES AND
DECOUPLES LATE EVENING... WINDS SHOULD DROP OFF TO THE 5 TO 10 MPH
RANGE. ANY FOG WILL BE SHALLOW AND MOSTLY LIKELY IN LOW SPOTS OR
LOCALLY COOLER AND LESS WIND SITES SUCH AS AN AIRFIELD. LOWS IN THE
60S TO AROUND 70 FORT PIERCE SOUTH.
THU-THU NIGHT...LOW PRESSURE SYSTEM MOVING EAST ACROSS THE SOUTHEAST
STATES AND NORTHERN GULF OF MEXICO WILL CONTINUE TO KEEP THE SURFACE
HIGH PRESSURE WELL SOUTH OF EAST CENTRAL FLORIDA. RESULTING SOUTH TO
SOUTHWEST WINDFLOW WILL FEED MOISTURE FROM THE SOUTHEAST GULF AND
FLORIDA STRAITS NORTHWARD OVER THE PENINSULA AND INCREASE THE DEPTH
OF MOISTURE. COLD TEMPERATURES ALOFT...AGAIN IN THE -12C TO -14C
RANGE...AND WEAK MID LEVEL DISTURBANCES CROSSING OVERHEAD LATE
OVERNIGHT AND DURING THE MORNING MAY PROVIDE ENOUGH FORCING FOR
ISOLATED SHOWERS IN THE MORNING AND SCATTERED AFTERNOON STORMS IN
THE NORTH HALF OF THE FORECAST AREA AND ISOLATED OVER THE SOUTHERN
HALF. HIGHS IN THE UPPER 80S EXCEPT WESTERN PORTIONS OF OSCEOLA AND
OKEECHOBEE ALONG THE KISSIMMEE RIVER FROM LAKE KISSIMMEE SOUTH.
STORM CHANCES CONTINUE TO INCREASE FROM N-S FROM AROUND SUNSET INTO
THE MID-LATE EVENING AS HIGHER BAND OF PWATS OVERSPREAD MOST OF THE
CWA AHEAD OF THE LATER-ARRIVING MID LEVEL SHORT WAVE TROUGH AND
FRONTAL BOUNDARY. INTERESTING TO SEE THAT THE LATE AFTERNOON SPC DAY
2 OUTLOOK PLACED THE NRN 2/3 CWA IN "SLGT RISK". POTENTIAL LOOKS LIKE
IT SHOULD BE CENTERED AROUND 00Z...2-3 HRS EITHER SIDE. CLOUD COVER
FROM UPSTREAM BLOWOFF AND/OR LOSS OF DAYTIME HEATING COULD BE A
LIMITING FACTOR IN STORM STRENGTH...REMAINS TO BE SEEN.
FRI-SAT...SHORTWAVE TROUGH AXIS WILL PUSH OFF THE COAST ON FRI AND
AN EARLY APRIL COLD FRONT WILL SLIDE INTO THE AREA LATE. WILL HOLD
ONTO A CHANCE OF STORMS FRI AHEAD OF THE FRONT AS MAX TEMPS WILL
CONTINUE WARM IN THE MID-UPPER 80S. MOS POPS REALLY DROP OFF FRI
NIGHT AS GUSTY NORTH/NORTHEAST WINDS BRING IN MUCH DRIER AIR. WILL
NOT CARRY ANY POPS OVER LAND BUT WOULD NOT BE SURPRISED TO SEE A FEW
LIGHT SHOWERS ESPECIALLY ALONG THE TREASURE COAST FRI NIGHT INTO SAT
MORNING. THE LATEST MOS INDICATES MAX TEMPERATURES BELOW NORMAL FOR
SAT WITH READINGS MAINLY IN THE 70S.
SUN-WED (PREV)...SURFACE HIGH PRESSURE RIDGE AXIS WILL SLIDE INTO
THE AREA SUN WHILE WEAKENING. THE RIDGE WILL WEAKEN FURTHER MON AS
IT SHIFTS INTO SOUTH FLORIDA. NEAR TO SLIGHTLY BELOW NORMAL TEMPS
ARE INDICATED SUN/MON. THE GFS INDICATES A FRONTAL BOUNDARY DROPPING
DOWN FROM THE NORTH AGAIN ON TUE WITH SLIGHT CHANCE POPS. SINCE DEW
POINTS ARE ONLY FORECAST TO BE IN THE 50S AND FRONTAL CONVERGENCE
LOOKS WEAK...WILL NOT INTRODUCE POPS YET. COOLER THAN NORMAL TEMPS
ARE INDICATED BEHIND THE FRONT ON WED AS AMPLIFYING FLOW ALOFT
DRIVES SINGLE DIGIT 850 MB TEMPS INTO THE AREA AGAIN.
&&
.AVIATION...ISOLATED MVFR TIL 02Z FROM AROUND LAKE GEORGE TO DAYTONA
BEACH THEN SOUTH ALONG THE COAST TO JUPITER INLET AND INDIANTOWN.
AFTER 02Z VFR WITH TEMPO MVFR MIST 09Z-12Z.
&&
.MARINE...CURRENT-THIS EVENING...THE TWO NOAA BUOYS WERE RECORDING
SPREAD OF SOUTHWEST WIND...AROUND 5 KNOTS AT BUOY 009 AND AROUND 15
KNOTS AT BUOY 010 AND SEAS RANGING FROM 3 TO 5 5 FEET WITH A 2 TO 3
FOOT LONG PERIOD SWELL. THE TWO SCRIPPS BUOYS...4 AND 6 NM OFF THE
BEACH... WERE RECORDING 2 FOOT LONG PERIOD SEAS. WINDS SHOULD TAKE
ON A SOUTHERLY COMPONENT NEAR THE COAST FROM AROUND FORT PIERCE
INLET SOUTH AS A SEA BREEZE CIRCULATION STRUGGLES TO SET UP BUT DOES
NOT SHIFT PAST SOUTH SOUTHEAST AND ONLY UNTIL MID EVENING IF THAT.
OVERNIGHT AND THU...AFTER MID EVENING IT SHOULD BE SOUTHWESTERLY
WINDS 10 TO 15 KNOTS OVERNIGHT AND THURSDAY WITH THE SURFACE RIDGE
AXIS REMAINING WELL SOUTH OF THE MARINE FORECAST AREA. WINDS WILL
INCREASE LATE THU AS THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO
THE SOUTH AND THE ADVANCING FRONT STRENGTHENS. CHANCE FOR STORMS
INCREASES FROM LATE AFTERNOON/EVENING AND CONTINUES N-S INTO FRI.
THE MODELS SHOW INCREASING NORTH WINDS LATE FRI AS A COLD FRONT
DROPS DOWN THE PENINSULA...WITH SMALL CRAFT ADVISORY CONDITIONS
LOOKING TO BE A GOOD BET BY FRI EVENING.
THIS WEEKEND...BREEZY NORTHEAST WINDS ARE EXPECTED SAT WITH ADVISORY
CONDITIONS CONTINUING. HIGH PRESSURE WILL WEAKEN SUNDAY WITH RIDGE
AXIS SETTLING CLOSER TO THE WATERS SO WINDS WILL DIMINISH...BUT SEAS
WILL BE SLOW TO SUBSIDE.
&&
.FIRE WEATHER...ALTHOUGH TEMPERATURES WILL BE WARMER THU THE
DEEPENING SOUTH TO SOUTHWEST WIND SHOULD TRANSPORT HIGHER DEW POINT
AIR INTO EAST CENTRAL AND KEEP RELATIVE HUMIDITY VALUES ABOVE
CRITICAL THRESHOLDS. TRANSPORT WINDS HOVER AROUND 15 MPH. SLIGHT
DRYING SHOULD OCCUR ON FRI AS A FRONT DROPS DOWN FROM THE NORTH BUT
NO LOW RH IS FORECAST. NORTH WINDS COULD BECOME GUSTY LATE IN THE
AFTERNOON ESPECIALLY ALONG THE NORTH COAST.
THIS WEEKEND...WINDS WILL VEER QUICKLY TO THE NORTHEAST ON SAT. IT
SHOULD BE BREEZY ALONG THE COAST. MIN RH VALUES 35-40 PERCENT ARE
EXPECTED ACROSS THE NORTH INTERIOR. ONSHORE FLOW WILL DIMINISH SUN
AND MIN RH VALUES AROUND 35 PERCENT SHOULD OCCUR ACROSS THE NORTH
INTERIOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 68 89 67 84 / 20 30 40 50
MCO 67 89 68 86 / 10 30 40 40
MLB 69 87 70 86 / 20 20 40 40
VRB 69 88 70 86 / 20 20 40 40
LEE 66 89 67 85 / 10 40 40 40
SFB 66 89 68 86 / 10 30 40 40
ORL 67 89 69 86 / 10 30 40 40
FPR 70 88 70 86 / 20 20 40 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX....CRISTALDI
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1224 PM EDT WED APR 4 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A FRONTAL SYSTEM IS EXPECTED TO SETTLE SOUTH ACROSS THE AREA EARLY
TODAY...EVENTUALLY PUSHING SOUTH OF THE OHIO RIVER. A WAVE OF LOW
PRESSURE WILL MOVE THROUGH THE TENNESSEE VALLEY AROUND THURSDAY. IN
THE WAKE OF THIS LOW...HIGH PRESSURE IS EXPECTED TO MOVE INTO THE
AREA THROUGH THE END OF THE WEEK. ANOTHER FRONTAL SYSTEM MAY
APPROACH THE AREA OVER THE WEEKEND...WITH HIGH PRESSURE MOVING BACK
IN EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
SOME FRONTOGENESIS AND ISENTROPIC LIFT OVER THE AREA IS PRODUCING
SCATTERED SHOWERS ACROSS SOUTHERN AND WESTERN PARTS OF THE AREA AT
1445Z. EXPECT THESE TO CONTINUE TO DEVELOP AND SPREAD EAST OVER THE
NEXT COUPLE OF HOURS. IN ADDITION THESE SHOWERS COULD DEVELOP INTO
THUNDERSTORMS OVER THE NEXT FEW HOURS AS INSTABILITY INCREASES SO
KEPT A CHANCE FOR THUNDERSTORMS GOING LATE THIS MORNING AND INTO THE
AFTERNOON APPROXIMATELY SOUTH OF I 70 WITH A SLIGHT CHANCE TO THE
NORTH. THE HRRR MODEL IS SHOWING DEVELOPMENT ACROSS MUCH OF THE AREA
THIS AFTERNOON AND EVENING BUT GIVEN IT/S OUTLIER STATUS AND ITS
GENERALLY POORER PERFORMANCE LATELY GENERALLY THREW OUT IT/S MORE
ROBUST SOLUTION. TWEAKED DEW POINTS/WINDS/TEMPERATURES/SKY COVER TO
MATCH CURRENT CONDITIONS AND TRENDS BUT THIS RESULTED IN CHANGES OF
ONLY A COUPLE DEGREES HERE AND THERE WITH SLIGHTLY HIGHER DEWPOINTS
IN THE NORTH AS WELL AS SLIGHTLY WARMER TEMPERATURES IN THE SOUTH.
STILL GOING WITH HIGHS IN THE MIDDLE 60S TO LOW 70S.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
OVERRUNNING IS EXPECTED TO DEVELOP NORTH OF THE FRONTAL BOUNDARY BY
THIS EVENING AS AN UPPER LOW APPROACHES THE OHIO VALLEY FROM THE
WEST. LEFT IN CHANCE POPS ACROSS THE SOUTH FOR TONIGHT. ONCE SURFACE
WAVE PASSES THROUGH THE TENNESSEE VALLEY ON THURSDAY...HIGH PRESSURE
WILL NOSE SOUTH FROM CANADA...RESULTING IN DRY CONDITIONS BY
THURSDAY AND LASTING THE REST OF THE PERIOD.
REALLY DID NOT STRAY FAR FROM PREVIOUS FORECAST TEMPERATURES THIS
PERIOD. BASED ON PROGGED LOW LEVEL THICKNESSES...THE GFS MOS
TEMPERATURE GUIDANCE LOOKS PRETTY REASONABLE. FREEZING TEMPERATURES
ARE STILL POSSIBLE BY FRIDAY MORNING...HOWEVER WINDS AT THE SURFACE
LOOK TO BE TOO STRONG FOR EVEN PATCHY FROST FORMATION...AND HAVE
DECIDED TO CONTINUE TO OMIT THIS MENTION FROM THE FORECAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD BEGINS WITH FAIRLY STRONG RIDGING AT THE SURFACE
AND ALOFT OVER THE AREA. AN UPPER LEVEL WAVE AND TRAILING COLD
FRONT MAKES PROGRESS INTO THE UPPER GREAT LAKES BY SATURDAY NIGHT
INTO EARLY SUNDAY...WITH AN OPPORTUNITY FOR SHOWERS AND
THUNDERSTORMS. A BRIEF QUIET WX PERIOD EXPECTED BEFORE ANOTHER
UPPER WAVE CONSOLIDATES WITH THE INITIAL SYSTEM AND PARKS OVER THE
NORTHEAST. THIS SYSTEM REPRESENTS THE ONLY SIGNIFICANT
DISAGREEMENT BETWEEN THE MAJOR MODELS...IN THAT THE EURO IS MUCH
MORE PROGRESSIVE WITH THE UPPER LOW. INITIALIZATION SEEMS TO BE
INFLUENCED SLIGHTLY MORE BY THE PROGRESSIVE SOLUTION...AND THIS IS
REASONABLE GIVEN THE ECMWF/S TYPICAL SUPERIORITY. THIS UPPER LOW
SHOULD BRING AT LEAST 12-24 HOURS OPPORTUNITY FOR SHOWERS TO THE
AREA.
INITIALIZATIONS TEMPS APPEAR REASONABLE WITH MINOR TWEAKS. COOLING
TREND SHOULD DOMINATE THE LONG TERM...WITH ABOVE NORMAL TEMPS EARLY
TRANSITIONING TO BELOW NORMAL TEMPS WITH THE UPPER LOW.
&&
.AVIATION /DISCUSSION FOR 1800Z ISSUANCE/...
RADAR INDICATES LIGHT SHOWERS ACROSS CENTRAL IL EWD INTO CENTRAL
INDIANA AND DWON THRU SRN PARTS OF INDIANA. QUASI STATIONARY
FRONTAL BOUNDARY IS ACROSS SRN INDIANA WHERE THERE IS SLY FLOW
SOUTH OF THE BOUNDARY THAT IS TRACKING NWD OVER THE FRONT
PRODUCING THE SHOWER ACTIVITY. MAY HAVE TO REFLECT IN THE TAFS
THAT THIS ACTIVITY IS MORE WIDESPREAD RESULTING IN OCCASSIONAL
MVFR CONDITIONS AND THAT THERE IS ALSO SOME ISOLATED THUNDER NOW
SW OF KIND. LOOKS LIKE PRECIPITATION WILL LINGER THRU EARLY THIS
EVENING BEFORE HIGH PRESSURE FROM THE NORTH BUILDS SOUTHWARD
FORCING THE FRONT AND SHOWERS AWAY FROM AREA.
LOOK FOR VFR CONDITIONS OVERNIGHT FOR MOST STATIONS TONIGHT THRU
THURSDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...CP
SHORT TERM...SMF
LONG TERM....NIELD
AVIATION...MCCARTHY
AREA FORECAST DISCUSSION
NWS JACKSON KY
216 PM EDT WED APR 4 2012
.UPDATE...
ISSUED AT 213 PM EDT WED APR 4 2012
CU HAS DEVELOPED IN MANY AREAS RATHER QUICKLY DURING THE PAST HOUR
WITH SCATTERED SHOWERS AND THUNDERSTORMS FOLLOWING RATHER QUICKLY
BEHIND. THE INITIAL STORMS SEEMED TO DEVELOP ALONG ALONG BOUNDARIES
OR THE ESCARPMENT...BUT A MID LEVEL DISTURBANCE IS INTERACTING WITH
THE BOUNDARY NEAR THE OH RIVER. ADDITIONAL MORE WIDESPREAD CONVECTION
IS NEAR THE KY/IN/OH TRI STATE AREA AND SHOULD EVENTUALLY
MOVE/DEVELOP EAST SOUTHEAST TOWARD OUR NORTHERN COUNTIES WHERE THE
ENVIRONMENT IS MORE UNSTABLE. HOURLY POPS AS WELL AS TEMP AND
DEWPOINTS WERE ADJUSTED ACCORDINGLY BASED ON THE LATEST TRENDS. AS
MENTIONED EARLIER...HEAVY RAIN STILL DOES APPEAR TO BE A GREATER
THREAT FROM ANY STORMS AS COMPARED TO SEVERE...ALTHOUGH MARGINALLY
LARGE HAIL OR DAMAGING WIND GUSTS FROM A STRONGER STORM OR TWO CANNOT
BE COMPLETELY RULED OUT.
UPDATE ISSUED AT 1043 AM EDT WED APR 4 2012
CONVECTION THAT WAS ATTEMPTING TO MOVE INTO THE REGION FROM CENTRAL
KY IN THE MORNING HAS DISSIPATED TO NOTHING MORE THAN SOME LOW TO
MID LEVEL CLOUDINESS. THERE IS A RATHER LARGE SECTION OF THE AREA
STARTING TO GET SOME SIGNIFICANT SUNSHINE. THE LINGERING VALLEY FOG
AND STRATUS IN THE CUMBERLAND VALLEY HAS DISSIPATED.
CONVECTIVE DEVELOPMENT TODAY WILL LIKELY HOLD OFF INTO THE EARLY TO
MID AFTERNOON...OR GENERALLY LATER THAN THE 12Z NAM IS PROJECTING.
THE APPROACHING BOUNDARY AS WELL AS MESOSCALE FEATURES SUCH AS
DIFFERENTIAL HEATING FROM TERRAIN OR ALONG THE INTERFACES BETWEEN
WHERE HEAVIER PRECIPITATION FELL ON TUE AFTERNOON/AND EVENING AND
WHERE IT WAS MUCH LIGHTER OR NEARLY RAINFREEE AND ANY LEFTOVER
OUTFLOWS ARE POSSIBLE POINTS WHERE DEVELOPMENT MIGHT OCCUR FIRST.
THE MID LEVEL IMPULSE MOVING TOWARD THE MID ATLANTIC STATES MAY HAVE
SOME FRINGE EFFECTS AS WELL THIS AFTERNOON INTO THIS EVENING IN
AIDING IN SOME ORGANIZATION TO THE CONVECTION. SHEAR AND INSTABILITY
PARAMETERS FORECAST BY THE MODELS APPEAR TO BE MORE OR LESS ON THE
MARGINAL END OF THE SPECTRUM WITH THE FORECAST SOUNDINGS MORE MOIST
WITH A BIT HIGHER PW COMPARED TO TUE. DEPENDING ON EVOLUTION OF
INSTABILITY...A FEW STORM COULD PRODUCE DAMAGING WINDS AND OR
MARGINALLY SEVERE HAIL AS NOTED IN THE MOST RECENT SPC OUTLOOK.
HOWEVER...THE FLASH FLOOD THREAT MAY BE GREATER. THE ORIENTATION OF
THE STALLED OR NEARLY STALLED OUT BOUNDARY SLOWLY SAGGING SOUTH OF
THE OH RIVER AND WESTERLY FLOW...BUT PROJECTED STORM MOTION NEAR 15KT
AND THE HIGH PW ON THE ORDER OF JUST UNDER 2SD ABOVE NORMAL DEFINITELY
POINTS TO A THREAT FOR SOME HEAVY RAIN WHERE THUNDERSTORMS OCCUR...AS
THERE COULD BE TRAINING.
SOME LOCATIONS HAD SOME WATER ISSUES YESTERDAY...ESPECIALLY LETCHER
COUNTY AND SOME LOCATIONS RECEIVED ABOUT 1 TO 2 INCHES OF RAIN FROM
THUNDERSTORMS ON TUE AFTERNOON OR EVENING...WITH LOCALLY HIGHER
AMOUNTS. GIVE ALL OF THESE FACTORS...WE WILL KEEP THE FLOOD WATCH IN
EFFECT AS IS FOR THIS UPDATE.
UPDATE ISSUED AT 745 AM EDT WED APR 4 2012
ISSUED A QUICK UPDATE TO ADJUST POPS IN THE NEAR TERM WITH THE LATEST
EXPECTATIONS OF THIS FIRST WAVE THIS MORNING AND THEN BUILDING IT UP
IN THE AFTERNOON A BIT FURTHER NORTH. IN ADDITION...UPDATED THE
TEMPS...WINDS AND DEWPOINTS TO BETTER REFLECT CURRENT CONDITIONS AND
TRENDS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED APR 4 2012
07Z SFC ANALYSIS SHOWS A LOW CENTERED OVER SOUTHERN MISSOURI WITH A
WEST TO EAST WARM FRONT/ELONGATED AREA OF LOWER PRESSURE RUNNING
GENERALLY ALONG THE OHIO RIVER. THIS BOUNDARY HAS REMAINED
INTERMITTENTLY ACTIVE THROUGH THE NIGHT...EVEN AS THE MORE ROBUST...
DIURNALLY DRIVEN...SLOW MOVING CONVECTION DIED OUT OVER EAST
KENTUCKY DURING THE LATE EVENING. DO EXPECT THAT THIS REGION OF LOWER
PRESSURE WILL BECOME MORE ACTIVE TOWARD DAWN IN CONJUNCTION WITH A
SLOW MOVING BAND OF MID LEVEL SHORTWAVES RUNNING THROUGH THE
SOUTHERN OHIO VALLEY. THE ENVIRONMENT IS RELATIVELY MOIST OVER THE
AREA WITH DEWPOINTS RUNNING IN THE MID AND UPPER 50S WHILE
TEMPERATURES ARE SETTLING INTO THE LOWER 60S IN MOST PLACES...EARLY
THIS MORNING.
THE MODELS ARE IN DECENT AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST AS THEY ALL ROLL A CLOSED AND SOMEWHAT CUT OFF
LOW THROUGH THE SOUTHERN PLAINS AND TOWARDS THE LOWER OHIO VALLEY BY
THURSDAY MORNING. FLAT RIDGING AND DEEP SOUTHWEST FLOW EXIST OUT
AHEAD OF THIS LOW AFFECTING KENTUCKY AND THIS WILL BE SQUEEZED OFF
TO THE EAST BY 12Z THURSDAY. AT THE SAME TIME...A DEEP TROUGH OVER
THE NORTHEAST WILL SHIFT SLIGHTLY SOUTH. GIVEN THE MODEL SIMILARITIES
ALOFT HAVE GONE WITH A BLENDED SOLUTION WITH A LEAN TOWARD THE
HIGHER RESOLUTION NAM12...AND A NOD TO THE HRRR IN THE NEAR TERM...
BUT TRANSLATED SLIGHTLY SOUTH IN LINE WITH THE OTHER MODELS LATTER IN
THE SHORT TERM.
AN ACTIVE WEATHER PERIOD IS UPON US WITH THE APPROACH OF THE UPPER
LOW TO THE WEST AND THE STALLED BOUNDARY LAYING OVER NORTHERN PARTS
OF EAST KENTUCKY. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP
AND INCREASE THROUGH THE AREA LATER TODAY AS DIURNAL HEATING
INITIATES CONVECTION...HELPED ALONG BY SFC CONVERGENCE WITH THE
BOUNDARY AND SOME UPPER LEVEL DIVERGENCE. THE STEAMY BOUNDARY LAYER
WILL CONTRIBUTE TO HIGH INSTABILITY TODAY WITH MID LEVEL WINDS
FAVORABLE FOR MORE ORGANIZED CONVECTION. AS A RESULT...STRONG TO
SEVERE THUNDERSTORMS WILL BE POSSIBLE THROUGH THE AREA WITH HIGH PW
AIR SETTING THE STAGE FOR HEAVY RAIN FROM ANY HEALTHY STORMS.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREAT FROM THESE. THE
STORMS WILL BE MORE PROGRESSIVE THAN YESTERDAY...BUT TRAINING...AND
PLENTY OF AREAS OF LOWER FFG AFTER YESTERDAY/S RAINS...WILL MAKE
FLASH FLOODING A CONCERN LATER TODAY AND THROUGH THE FIRST PART OF
THE NIGHT. ACCORDINGLY...WILL HOIST A FLASH FLOOD WATCH FOR ALL BUT
OUR NORTHWEST COUNTIES. THE HEAVIER RAINS WILL DISSIPATE BY THURSDAY
MORNING AS DRIER AIR SEEPS INTO THE REGION FROM THE NORTH...BUT THE
THREAT OF SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE DAY. THE
BAROCLINIC ZONE IN PLACE THROUGH THE AREA ON THURSDAY WILL KEEP THE
NORTHERN COUNTIES UP TO 10 DEGREES COOLER THAN THE SOUTHERN ONES FOR
HIGHS.
HAVE FOLLOWED A BLEND OF THE MOS GUIDANCE THROUGH THE PERIOD ALLOWING
THE MAV NUMBERS TO TEMPER THE MET/S...WITH LITTLE IN THE WAY OF
TERRAIN ADJUSTMENTS GIVEN THE MOIST ENVIRONMENT. DID FAVOR THE MET
POPS THROUGH THE SHORT TERM...BUT HAD THEM TRANSLATED MORE TO THE
SOUTH OWING TO THE CONSENSUS FAVORING MORE SUPPRESSION OF THE FRONTAL
BOUNDARY FROM THE HIGH TO THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 AM EDT WED APR 4 2012
THE MODELS ARE IN GOOD AGREEMENT REGARDING THE EVOLUTION OF WEATHER
SYSTEMS FOR THE DAY 4-7 PERIOD. INITIALLY...SCATTERED RAIN SHOWERS
WILL BE PRESENT FROM THE TENNESSEE BORDER NORTHWARD TO THE HAL
ROGERS PARKWAY AND ALONG AND NORTH OF THE HIGHWAY 80 CORRIDOR. THESE
RAIN SHOWERS WILL LIKELY LINGER THROUGH 9 OR 10Z ACROSS THIS AREA ON
FRIDAY MORNING...BEFORE EXITING INTO VIRGINIA BY 13Z OR SO. AFTER
THAT...THE MODELS ALL AGREE THAT HIGH PRESSURE WILL BECOME FIRMLY
ESTABLISHED ACROSS THE OHIO AND TENNESSEE VALLEY AREAS THROUGH
SUNDAY MORNING. THE GFS AND ECMWF BOTH ARE QUICKLY MOVING A WEAK
FRONTAL BOUNDARY AND UPPER LEVEL TROUGH ACROSS THE REGION ON SUNDAY.
THESE FEATURES WILL JUST STRONG ENOUGH AND HAVE JUST ENOUGH MOISTURE
ASSOCIATED WITH THEM TO SPARK ISOLATED TO SCATTERED RAIN SHOWERS. AT
THIS TIME THE MODEL DATA INDICATE THAT THE ATMOSPHERE WILL ONLY BE
ABLE TO SUPPORT ISOLATED THUNDERSTORM ACTIVITY. WITH ALL THAT IN
MIND...THE INHERITED FORECAST FOR SUNDAY WAS ADJUSTED TO REFLECT
PRECIPITATION CHANCE THAT WERE A GOOD DEAL LOWER...AND MORE IN LINE
WITH THE LATEST MEXMOS DATA...WHICH WAS REFLECTIVE OF 20-30 PERCENT
PRECIPITATION PROBABILITIES ACROSS THE BOARD. ANOTHER AREA OF WEAK
HIGH PRESSURE WILL THEN BECOME ESTABLISHED ACROSS THE SUNDAY NIGHT
AND MONDAY. ANOTHER EVEN MORE ILL DEFINED FRONTAL BOUNDARY AND UPPER
TROUGH COMBO WILL BRING SCATTERED RAIN SHOWERS TO EASTERN KENTUCKY
MONDAY NIGHT AND TUESDAY. THE WEATHER...SKY COVER...AND
PRECIPITATION AMOUNT FORECASTS WERE ALL ADJUSTED BASED ON THE LOWER
PRECIPITATION PROBABILITIES. ACCOUNTING FOR THE AMOUNT OF CLOUD
COVER AND PRECIPITATION EXPECTED...AND WITH SOMEWHAT COOLER AIR
MASSES EXPECTED TO MOVE ACROSS THE AREA...TEMPERATURES WILL BE VERY
CLOSE TO NORMAL THROUGH MONDAY...AND MAY EVEN BE SEVERAL DEGREES
BELOW NORMAL NEXT TUESDAY AS COOLER AIR MAKES A FAIRLY DEEP
SOUTHWARD INTRUSION INTO THE EASTERN CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 213 PM EDT WED APR 4 2012
A NEARLY STATIONARY FRONT NEAR THE OH RIVER IS COMBINING WITH DAYTIME
HEATING AND A MID LEVEL DISTURBANCE TO BRING ISOLATED TO SCATTERED
SHRA/TSRA. THROUGH AT LEAST 22Z WE EXPECTED FURTHER DEVELOPMENT AND
EXPANSION OF SHOWERS AND THUNDERSTORMS THROUGH THE AREA AND SOME THAT
ARE CURRENTLY UPSTREAM MAY ADVECT IN AS WELL. ATTM...WE WENT WITH VCTS
AT THE START OF THE PERIOD. ANY STORM WILL BRING WITH IT AT LEAST
BRIEF MVFR OR LOWER CIGS AND VIS DOWN TO IFR OR LESS IN ANY HEAVY
RAIN OR HAIL. STORMS AND/OR MVFR CONDITIONS WILL BE POSSIBLE THROUGH
MUCH OF THE PERIOD ALONG AND JUST BEHIND THE SAGGING FRONT. WINDS
THROUGH THE PERIOD WILL BE GENERALLY FROM THE WEST AT 5 TO 10 KTS
THROUGH THE FIRST 6 HRS AT THE TAF SITES AND THEN BEGIN TO SHIFT TO
THE NORTH OR NORTHEAST ONCE THE BOUNDARY PASSES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 2 AM EDT THURSDAY FOR KYZ058>060-068-069-
079-080-083>088-104-106>120.
&&
$$
UPDATE...UPDATE...JP
SHORT TERM...GREIF
LONG TERM....AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1145 AM MDT WED APR 4 2012
UPDATED AVIATION
.UPDATE...
CLOUD COVER AND THE LINGERING EASTERLY WINDS HAS KEPT MUCH OF THE
AREA A BIT COOLER THAN FORECAST. SHORT RANGE MODELS SHOW THAT EVEN
WITH THIS DELAY IN THE HEATING AND THE WARMING DOWNSLOPE WINDS
THAT IT WILL COME BY THIS AFTERNOON AS THE SFC LOW MOVES INTO THE
NORTH CENTRAL MONTANA PLAINS AND THE WARMING WESTERLY OR
SOUTHWESTERLY WINDS WILL SET-UP AND THE CLOUDINESS WILL WANE
ALLOWING FOR MORE INSOLATION/HEATING. HAVE ADJUSTED THE HOURLY
TEMPS TO ACCOUNT FOR THE LOWER TEMPS THAN EXPECTED THIS LATE
MORNING AND THE WARMING AS THE CLOUDS BREAK THIS AFTERNOON AND THE
WINDS PICK UP. OTHER PORTIONS OF THE FORECAST STILL LOOK FINE WITH
RESPECT TO FIRE WEATHER CONCERNS ACROSS SW MONTANA...AND PRECIP
CHANCES DUE TO AN SCATTERED SHOWER OR ISOLATED THUNDERSTORMS ACROSS
NORTH CENTRAL MONTANA. RUC SHOWING CAPES NEARING 250-350J/KG AND
DECENT MID LVL LAPSE RATES AROUND 8.5 DEGREES C BY THIS AFTERNOON
AND SHOULD ALLOW FOR THE FORECASTED AFTN ISOLATED T-STORMS. --SCHOTT
&&
.AVIATION...
UPDATED 1800Z.
WIDESPREAD MID-LEVEL CLOUDS ARE CURRENTLY EXTENDING FROM
KCTB-KGTF-KLWT AND WILL DECREASE THIS AFTERNOON WITH WINDS SHIFTING
TO THE SOUTH. A COLD FRONTAL PASSAGE IS EXPECTED LATER THIS
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS ALONG AND BEHIND
THE BOUNDARY. ANY STORMS MAY HAVE GUSTY AND ERRATIC WINDS. BEST
CHANCES FOR THUNDER WILL BE AT KBZN AND KHLN. WINDS WILL BECOME
WESTERLY BEHIND THE COLD FRONT WITH THE TIMING AROUND 22Z FOR KCTB
AND KHLN...00Z FOR KGTF AND KBZN AND 02Z FOR KHVR AND KLWT.
OVERALL...VFR CONDITIONS ARE EXPECTED HOWEVER BRIEF INTRUSIONS OF
MVFR WITH SHOWERS AND POSSIBLE. MLV
&&
.PREV DISCUSSION...
/ISSUED 550 AM MDT WED APR 4 2012/
TODAY THROUGH FRIDAY...THE BEGINNING OF AN ACTIVE PERIOD OF
WEATHER WILL START TODAY...AND THEN CONTINUE INTO FRIDAY. A
PACIFIC COLD FRONT...CURRENTLY JUST MOVING INTO WESTERN MONTANA AT
4 AM...WILL MOVE SLOWLY EASTWARD TOWARDS CENTRAL MONTANA TODAY.
EXPECT THIS FRONT TO MOVE EAST OF THE DIVIDE THIS AFTERNOON...AND
THEN GRADUALLY MOVE THROUGH THE LEWISTOWN AREA THIS EVENING.
MILD TEMPERATURES ARE EXPECTED AHEAD OF THE FRONT...WITH THE
WARMEST LOCATIONS EXPECTED IN THE HAVRE/LEWISTOWN AREAS TODAY. AS
THE FRONT MOVES EAST OF THE DIVIDE...EXPECT SCATTERED SHOWERS TO
DEVELOP ALONG WITH A FEW THUNDERSTORMS. THE DYNAMICS ARE GOOD WITH
THIS SYSTEM...BUT THE INSTABILITY IS LOW. SO FOR NOW...I REMOVED
THE GUSTY WIND WORDING IN THE ZONES...BUT WE WILL CONTINUE TO
WATCH THIS CLOSELY. AGAIN...COOLER AIR MOVES INTO THE REGION
TONIGHT. AS THE MAIN STORM SYSTEM PULLS NORTHWARD INTO CANADA...A
BAND OF PRECIPITATION IS EXPECTED TO DEVELOP OVER SOUTHWEST
MONTANA. SOME SNOW IS LIKELY BY MORNING BETWEEN DILLON AND BIG
SKY. FOR NOW...THE BEST ACCUMULATING SNOWFALL SHOULD BE ABOVE 7000
FEET...SO I WILL HOLD OFF ON AN ADVISORY FOR NOW. THE PRECIP WILL
CONTINUE INTO THURSDAY OVER SOUTHWEST MONTANA...WITH JUST A FEW
SHOWERS OVER CENTRAL MONTANA...WHILE THE HI-LINE AREA STAYS MOSTLY
DRY ON THURSDAY AFTERNOON. AFTERNOON TEMPERATURES ON THURSDAY WILL
BE CLOSE TO 20 DEGREES COOLER THAN WEDNESDAY. THEN FOR THURSDAY
NIGHT AND INTO FRIDAY...BOTH THE EC/GFS MODEL PROG A STRONG AREA
OF LOW PRESSURE TO DEVELOP OVER SOUTHERN WYOMING...AND THEN MOVE
NORTHEASTWARD INTO THE UPPER MIDWEST. THIS TRACK WOULD ALLOW FOR
HEAVY SNOW TO DEVELOP IN THE MOUNTAINS OF SOUTHWEST MONTANA ON
THURSDAY NIGHT AND THEN SPREAD NORTHWARD INTO CENTRAL MONTANA BY
FRIDAY MORNING. THE HEAVIEST SNOWFALL SHOULD OCCUR IN THE
MOUNTAINS WITH THIS SYSTEM...BUT SEVERAL INCHES OF SNOW ARE
POSSIBLE AT LOWER ELEVATIONS IN SOUTHWEST/CENTRAL MONTANA. THUS A
WINTER STORM WATCH HAS BEEN ISSUED FOR ALL ELEVATIONS. AFTERNOON
TEMPERATURES ON FRIDAY WILL CONTINUE THE COOLING TREND...WITH THE
CLOUDS/PRECIP...MOST AREAS WILL ONLY SEE HIGHS IN THE 30S. BRUSDA
FRIDAY NIGHT THROUGH WEDNESDAY...MODELS ARE IN FAIRLY GOOD AGREEMENT
DURING THE PERIOD SO CONFIDENCE IN THE FORECAST IS ABOVE AVERAGE.
FRIDAY NIGHT THE UPPER TROUGH OVER EASTERN MONTANA WILL MOVE SLOWLY
EAST AND EXPECT SNOW TO DIMINISH. SATURDAY NORTHWEST FLOW IS
EXPECTED ALONG WITH SOME RESIDUAL MOISTURE. DID NOT CHANGE THE
INHERITED FORECAST WHICH HAD A SLIGHT CHANCE OF PRECIPITATION OVER
THE PLAINS WITH A CHANCE OF SNOW OVER THE MOUNTAINS. THEREAFTER THE
FORECAST AREA WILL BE UNDER THE INFLUENCE OF A STRONG UPPER RIDGE
WHICH WILL MOVE OVER CENTRAL MONTANA MONDAY. THIS WILL RESULT IN A
WARMING TREND WITH HIGHS REACHING THE MID 50S TO MID 60S ON MONDAY.
MODELS DIFFER SOME ON HOW FAST THE UPPER RIDGE MOVES EAST THEREAFTER
BUT IT LOOKS LIKE WARM TEMPERATURES WILL CONTINUE INTO MIDWEEK. AS
FOR PRECIPITATION THE RIDGE SHOULD KEEP THE AREA DRY SATURDAY NIGHT
THROUGH TUESDAY WITH THE POSSIBLE EXCEPTION OF THE MOUNTAINS OF THE
ROCKY MOUNTAIN FRONT. MODELS ARE POINTING TO SOME INCREASE IN
MOISTURE BY WEDNESDAY OR WEDNESDAY NIGHT SO WENT WITH A SLIGHT
CHANCE OF SHOWERS FOR THE LOWER ELEVATIONS AND A CHANCE OF RAIN OR
SNOW SHOWERS FOR THE MOUNTAINS BY LATE WEDNESDAY. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 69 30 46 29 / 20 20 20 40
CTB 64 27 45 24 / 40 40 20 10
HLN 71 29 46 29 / 20 10 30 50
BZN 66 27 43 27 / 10 20 50 60
WEY 38 21 37 21 / 10 40 60 70
DLN 61 25 41 26 / 20 10 50 60
HVR 74 31 51 27 / 10 30 10 10
LWT 70 29 43 27 / 10 10 30 50
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY EVENING
BEAVERHEAD...BROADWATER...CASCADE...FERGUS...GALLATIN...
JEFFERSON...JUDITH BASIN...MADISON...MEAGHER.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR ELEVATIONS
BELOW 6000 FEET FOR GALLATIN...MADISON...MEAGHER.
&&
$$
UPDATE...SCHOTT
SHORT TERM...BRUSDA
LONG TERM...BLANK
AVIATION...MLV
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1136 AM MDT WED APR 4 2012
.UPDATE...
UPDATE TO PREVIOUS PACKAGE RELATIVELY MINOR. INCLUDES LOWERING
1ST PERIOD POPS A BIT FOR REMAINING AREAS...RAISING 1ST PERIOD
TEMPS JUST A FEW DEGREES SOME LOCALES AND RATCHETING BACK AMT OF
CLOUDS FOR CENTRAL AND NE SECTIONS FOR TODAY.
43
&&
.PREV DISCUSSION...300 AM MDT WED APR 4 2012...
WRAP AROUND/JET RELATED PRECIPITATION CONTINUING OVER
EASTERN HALF OF NEW MEXICO ATTM. LATEST RUC SHOWS UPPER LOW WILL
MOVE VERY SLOWLY THIS MORNING...CENTERED OVER THE NORTHERN TX
PANHANDLE BY NOON. RAIN WAS INDICATED TO BE THE PREDOMINANT
PRECIPITATION TYPE WITH THE WEST TO EAST ORIENTED BAND STRETCHING
ACROSS LINCOLN COUNTY TO NEAR MILNESAND. WITH TEMPS NEAR
FREEZING...SNOW WAS ASSOCIATED WITH THE WRAP AROUND ECHOES FROM
ANGEL FIRE TO RATON AND CLAYTON. EXPECT MINIMAL ACCUMULATIONS AND
IMPACTS WITH THIS...AS COMPARED TO THE LAST 36 HOURS.
OTHERWISE...AREAS OF LOW CLOUDS AND FOG WILL PLAGUE THE RIO GRANDE
VALLEY EASTWARD THIS MORNING.
THE LINGERING PRECIPITATION SHOULD BE OVER WITH BY THIS AFTERNOON.
HIGH TEMPERATURES WILL BE WARMER OVERALL TODAY...AND ALTHOUGH THE
SURFACE GRADIENT ISN/T VERY STRONG COULD NOT RULE OUT SOME NORTHWEST
TO NORTHERLY BREEZES IN THE EAST...BUT ESPECIALLY NEAR THE TEXAS
BORDER WHERE FORECAST H7 WINDS ARE AROUND 30KT.
MODELS INDICATE HIGH LEVEL MOISTURE INCREASING TONIGHT ...MAYBE
ENOUGH TO KEEP FOG FROM DEVELOPING OVER AREAS WHICH RECEIVED
SIGNIFICANT SNOWFALL MONDAY NIGHT/TUESDAY. CONFIDENCE NOT THAT GREAT
BUT WENT AHEAD AND PUT PATCHY FOG IN THE GRIDS FOR THE SANGRE DE
CRISTO MOUNTAINS/NORTHEAST HIGHLANDS AND OVER TOWARDS
CAPULIN/FOLSOM...WHERE MELTING SHOULD CONTINUE DURING THE DAY TODAY.
THURSDAY AND FRIDAY FEATURE A WARMING TREND WITH TEMPERATURES BACK
ABOVE NORMAL. INCREASING SOUTHWEST FLOW ALOFT IS ANTICIPATED AS A
SYSTEM PASSES THROUGH THE NORTHERN ROCKIES. THIS IS MUCH FARTHER
NORTH THAN SHOWN A COUPLE OF DAYS AGO...SO WINDS SHOULDN/T GET TOO
UNRULY.
A SURFACE FRONT DROPPING INTO THE PLAINS ON SATURDAY APPEARS TO
BE ENOUGH OF A MECHANISM TO IGNITE A FEW THUNDERSTORMS BUT
INITIALLY MAINLY TO OUR EAST. HOWEVER...AS SURFACE HIGH PRESSURE
SETTLES SOUTHWARD INTO THE CENTRAL/SOUTHERN PLAINS...LOW LEVEL
MOISTURE INCREASES INTO OUR EASTERN PLAINS. THE GFS IN PARTICULAR
HAS BEEN PRETTY ENERGETIC DEVELOPING WIDESPREAD AMOUNTS OF
PRECIPITATION SUNDAY THROUGH MONDAY OVER THE EASTERN HALF OF NEW
MEXICO...DESPITE THE REGION BEING UNDER A RATHER SHARP RIDGE ALOFT.
BASED ON THE FORECAST POSITION OF THE RIDGE AXIS...THE ARGUMENT
COULD BE MADE THAT THE EASTERN SIDE OF THE STATE WILL BE UNDER
NORTHWEST FLOW ALOFT BUT IT WILL BE PRETTY WEAK. THE LATEST 00Z
ECMWF IS EVEN JUMPING ON THIS IDEA THOUGH NOT QUITE AS EXTREME.
CURRENT POP/WX GRIDS HAVE THIS TREND COVERED AT LEAST FOR NOW.
THE MIDDLE TO LATE WEEK PERIOD NEXT WEEK APPEARS TO BECOME MORE
UNSETTLED AS AN UPPER TROUGH PUSHES INTO THE GREAT BASIN AND HEADS
FOR NEW MEXICO. THERE COULD BE POTENTIAL FOR A CLOSED LOW TO DEVELOP
AS IT REACHES THE EASTERN SLOPES OF THE ROCKIES...BASED ON
GFS/ECMWF. THERE/S STILL QUITE A BIT OF TIME FOR
CHANGES...CONSIDERING THE NOW EXITING STORM SYSTEM WAS SUPPOSED TO
BE DRY AND WINDY UNTIL ONLY A COUPLE OF DAYS PRIOR.
.AVIATION...AREAS OF LIGHT SNOW WILL AFFECT PORTIONS OF NORTHEAST NM
THROUGH 16Z RESULTING IN MVFR/IFR CIGS/VSBYS AT TIMES... ESPECIALLY
BETWEEN KLVS AND KRTN...AND NEAR THE NE NM/SE CO LINE. ELSEWHERE...
LOW CLOUDS AND FOG OR FREEZING FOG WILL CONTINUE TO DEVELOP/EXPAND
THROUGH DAYBREAK ESPECIALLY IN THE VALLEYS OF NC/NW NEW MEXICO THAT
RECEIVED SIGNIFICANT PRECIP DURING THE PAST 24 HOURS. HIGHEST
CONFIDENCE IN MVFR/BRIEF IFR CONDITIONS AT KSAF AND KABQ...AS WELL
AS KSKX AND THE UPPER RIO GRANDE VALLEY. PRECIP ENDING AND CIGS
RISING ACROSS NE NM BY MID- TO LATE MORNING AS THE STORM SYSTEM
PULLS AWAY AND LOW LEVEL DOWNSLOPE FLOW AND VFR CONDITIONS RETURN.
ELSEWHERE...ASIDE FROM MORNING LOW CLOUDS/FOG OR FREEZING FOG...VFR
CONDITIONS EXPECTED. KJ
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z.
.FIRE WEATHER...TEMPERATURES QUICKLY REBOUND TODAY...ALTHOUGH MAXES
WILL REMAIN JUST SHY OF SEASONAL AVERAGES ACROSS MUCH OF THE CENTRAL
AND EAST. THE NORTHEAST WILL BE SLOWEST TO RECOVER AND HIGHS THERE
WILL BE 5 TO 10 DEGREES BELOW NORMAL. WITH THE WARMING....AFTERNOON
HUMIDITY VALUES WILL TREND DOWNWARD IN A BIG WAY ESPECIALLY CENTRAL
AND NORTH CENTRAL AREAS. RH VALUES LOOK TO BOTTOM OUT IN THE TEENS
ACROSS THE SOUTH AND WEST...WITH MOSTLY 20S TO NEAR 40 ELSEWHERE.
VENTILATION WILL BE VERY GOOD TO EXCELLENT FOR A VAST MAJORITY OF
THE AREA LATER TODAY THANKS TO DEEP LAYER NORTHWEST FLOW ON THE
BACKSIDE OF THE DEPARTING STORM SYSTEM. THIS WILL TRANSLATE TO
MODERATE NORTHWEST BREEZES FOR MANY AREAS...ESPECIALLY EAST OF THE
CENTRAL MOUNTAIN CHAIN AND PORTIONS OF WEST CENTRAL NEW MEXICO. A
BRISK NORTH TO NORTHWEST WIND WILL ALSO DEVELOP ACROSS THE NORTHEAST
ONCE AREAS OF LIGHT SNOW END AFTER MID OR LATE MORNING.
WEAK HIGH PRESSURE ALOFT SLIDES OVER THE AREA TONIGHT. GIVEN THE
EFFECTS OF MELTING SNOW ON BOUNDARY LAYER MOISTENING...LOW CLOUDS
AND FOG/FREEZING FOG MAY REVISIT THE VALLEYS OF NORTHERN NEW MEXICO
TOWARD DAYBREAK THURSDAY. OTHERWISE THE DRYING AND WARMING TREND
WILL CONTINUE THROUGH THE END OF THE WORK WEEK. VENTILATION RATES
WILL BE IN THE EXCELLENT CATEGORY BOTH DAYS FOR A VAST MAJORITY OF
THE AREA.
AFTERNOON AND EVENING WINDS WILL BE MORE NOTICEABLE THURSDAY AND
ESPECIALLY FRIDAY AS MID-LEVEL GRADIENTS TIGHTEN AND BECOME MORE
WEST TO SOUTHWEST BY FRIDAY. WESTERN AREAS AND THE NORTHEAST WILL BE
FAVORED FOR BREEZY CONDITIONS THURSDAY AFTERNOON WITH MORE
WIDESPREAD BREEZY/WINDY CONDITIONS ON FRIDAY. HOWEVER...RECENT
MODEL TRENDS NOW SUPPORT LESS OVERALL WIND IMPACTS ON FRIDAY AS THE
MAIN SHORTWAVE IS LIFTING OUT FARTHER NORTH. EVEN SO...DEEP MIXING
DURING THE AFTERNOON/EVENING WILL BRING THE HIGHER MOMENTUM AIR TO
THE SURFACE AND COMBINED WITH LOWERING RH/S WILL RESULT IN AN
INCREASING THREAT FOR LOW END CRITICAL FIRE WEATHER GROWTH
CONDITIONS MAINLY ACROSS THE EAST CENTRAL PLAINS.
WEAK RIDGE ALOFT INDICATED SATURDAY AND SUNDAY WITH LESS WIND
AREAWIDE...THOUGH STRENGTHENING SOUTH OR SOUTHEAST SURFACE GRADIENTS
LIKELY ACROSS THE FAR EAST. WE WILL BE MONITORING LOW LEVEL
MOISTURE RETURN ACROSS PORTIONS OF SOUTH CENTRAL AND SOUTHEAST NEW
MEXICO LATE IN THE WEEKEND INTO EARLY NEXT WEEK...AS THE LARGE SCALE
WIND PATTERN IS FAVORABLE TO ALLOW FOR A SUBTLE BUT POTENTIALLY
SIGNIFICANT INCREASE BEGINNING SUNDAY. THIS COULD RESULT IN A
THREAT OF HIGH BASED SHOWERS OR VIRGA AT A MINIMUM...AND POSSIBLY
DRYLINE-ENHANCED THUNDERSTORMS ACROSS THE FAR EAST. HOW FAR WEST
AND NORTH THIS VIRGA THREAT EXPANDS IS VERY UNCERTAIN...BUT AREAS
ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN WILL BE VERY
SUSCEPTIBLE AND CLIMATOLOGICALLY-FAVORED. KJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
43
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 PM EDT WED APR 4 2012
.SYNOPSIS...
A STRONG BACK DOOR COLD FRONT WILL APPROACH FROM THE NORTH THIS
EVENING...THEN SURGE SOUTH THROUGH THE AREA LATE TONIGHT AND
THURSDAY MORNING. MUCH COOLER TEMPERATURES ARE EXPECTED IN THE WAKE
OF THE FRONT THURSDAY AND FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM WEDNESDAY...
A MODEST MID-LEVEL SHORTWAVE MOVING THROUGH CENTRAL NORTH CAROLINA
THIS MORNING HELPED TO INITIATE ISOLATED DEEP CONVECTION TOWARD KIXA
AND KRWI AROUND SUNRISE...WITH JUST ENOUGH ELEVATED INSTABILITY AND
STEEP LAPSE RATES NOTED AT LEAST ON FORECAST SOUNDINGS...SUCH AS THE
KFAY NAM BUFR SOUNDING FOR 12Z TODAY...TO PROVIDE FOR ISOLATED
SHOWERS AND THUNDERSTORMS. THE PRECIPITATION STARTED TO WANE DURING
THE MID-MORNING HOURS...AND THIS PRECIPITATION AND ITS EVOLUTION WAS
VERY WELL DEPICTED ON SOME OF THE 00Z WRF MODELS. WITH MSAS SHOWING
A RELATIVE MINIMUM OF SURFACE-BASED LIFTED INDICES AND THETA-E OVER
MUCH OF CENTRAL NORTH CAROLINA...AND IN SUBSIDENCE BEHIND THE
MID-LEVEL WAVE AS FORECAST BY BOTH THE LATEST RUC AND NAM...THERE
SHOULD BE LOW CHANCES FOR REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS
UNTIL LATER IN THE AFTERNOON. AT THAT POINT...BUFR SOUNDINGS FROM
THE NAM SHOW AVAILABLE INSTABILITY STARTING TO INCREASE...AS
LOW-LEVEL CIN IS OVERCOME AND LAPSE RATES ACTUALLY STEEPEN...TO AT
LEAST 7C/KM FROM 1000-500MB ON BOTH THE LATEST NAM AND RUC. WHILE
JET SUPPORT STAYS WELL TO THE NORTH IN THE MID- AND UPPER-LEVELS...
AND LOW-LEVEL WINDS ARE NOT FORECAST TO BE TOO STRONG...ONLY ABOUT
10-15 KNOTS FROM 925MB THROUGH 850MB WHICH IS COINCIDENT WITH SOME
OF THE LIGHTER WINDS ALOFT ON THE LATEST LOCAL AMDAR SOUNDINGS...
850MB CONVERGENCE INCREASES AND INVERTED-V-TYPE BUFR SOUNDINGS TAKE
SHAPE BY LATE IN THE AFTERNOON...CONTINUING INTO THE EVENING. WITH
THE FRONT TO THE NORTH AND SURFACE TROUGHINESS DEVELOPING TO THE
WEST DURING THE DAY...THE LIKELY SCENARIO IS THAT DEEPER CONVECTION
WILL DEVELOP TO OUR NORTH AND WEST AND MOVE SOUTHEAST ACROSS THE
AREA EITHER PROPAGATING OR REGENERATING OFF OF ITS COOL POOL. SOME
OF THE WRF GUIDANCE SUGGESTS MUCH OF THE PRECIPITATION STAYING NEAR
THE VIRGINIA BORDER AND NEAR OR WEST OF THE YADKIN RIVER THROUGH
LATE AFTERNOON...WHILE OTHERS SHOW A SURGE IN SHOWERS AND STORMS
MOVING SOUTHEAST ALONG AND SOUTH OF U.S. 64. WHILE LOCATION IS
UNCERTAIN...A LIKELY SCENARIO IS SOME DEVELOPMENT OF A CLUSTER OF
STORMS MOVING OVER SOME PART OF CENTRAL NORTH CAROLINA LATE TODAY
AND THIS EVENING WITH A POTENTIAL FOR DAMAGING WINDS. WET-BULB ZERO
VALUES ARE LOW...SO HAIL IS ALSO A THREAT. THE CURRENT HAZARDOUS
WEATHER OUTLOOK DISCUSSES THE TIMING AND PRIMARY THREAT OF DAMAGING
WINDS WELL.
HIGH TEMPERATURES SHOULD REACH THE MID 80S OVER MUCH OF CENTRAL
NORTH CAROLINA. THE AFTERNOON HIGH MAY COME CLOSE TO THE RECORD AT
KRDU...WHERE IT IS A COOL 87 DEGREES RELATIVE TO SURROUNDING DAYS.
THE KGSO RECORD IS 86...A LESSER CHANCE OF REACHING THAT ONE.
THOUGH INSTABILITY WILL BEGIN TO WANE AFTER SUNSET...ADDITIONAL
CONVECTION WILL BE POSSIBLE IN ASSOCIATION WITH THE BACK DOOR COLD
FRONT PROGRESSING SOUTH THROUGH VIRGINIA INTO CENTRAL NORTH CAROLINA
OVERNIGHT. WILL MAINTAIN A SLIGHT CHANCE (20%) NORTH TO LOW CHANCE
(30%) SOUTH FOR THE LATE NIGHT HOURS...WITH ISOLATED THUNDERSTORMS
MORE LIKELY IN SOUTHERN PORTIONS OF THE AREA. EXPECT LOWS TO RANGE
FROM THE LOWER/MID 50S IN THE NORTH AND NORTHEAST TO THE UPPER 50S
AND LOWER 60S IN THE SOUTH.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 310 AM WEDNESDAY...
AN UPPER LOW CURRENTLY LIFTING OUT OF NORTHEAST NM WILL DRIFT EAST
ACROSS THE MID MS RIVER VALLEY WEDNESDAY NIGHT... AND THEN BEGIN TO
MOVE SOUTHEAST TOWARD AL/GA ON THURSDAY AS IT APPROACHES THE
SOUTHERN EDGE OF BROAD CYCLONIC FLOW OVER THE NORTHEAST US. A COLD
FRONT AND/OR REMNANT CONVECTIVE OUTFLOW SHOULD BE NEAR THE
NC/SC BORDER BY 12Z THURSDAY...WHERE A FEW ISOLATED SHOWERS CANNOT
BE RULED OUT DURING THE MORNING HOURS. HOWEVER...MOST OF THE
CENTRAL NC SHOULD BE DRY THROUGH THURSDAY AFTERNOON AS A SURFACE
HIGH PRESSURE RIDGE SETTLES IN BEHIND THE FRONT AND A WEAK SHORTWAVE
UPPER RIDGE SHIFTS ACROSS NC AHEAD OF THE APPROACHING UPPER LOW.
WHILE FORECAST SOUNDINGS SUGGEST THE BOUNDARY LAYER WILL BE SLOW TO
SATURATE UNTIL LATER THURSDAY EVENING...THE LOW
LEVEL COLD ADVECTION BEHIND THE FRONT SHOULD BE HELP TO LOCK IN
STRATUS AT 2-3K FT WHERE MOISTURE WILL ALREADY EXIST. THUS...TEMPS
WILL STRUGGLE TO RISE UNTO THE LOW TO MID 60S...A GOOD 20 DEGREES
COOLER THAN WEDNESDAY.
FORCING FOR ASCENT...IN THE FORM OF INCREASING DIVERGENCE
ALOFT...WEAK LOW LEVEL WARM ADVECTION AND 60-80M HEIGHT FALLS...WILL
ARRIVE THURSDAY EVENING AS THE UPPER LOW DIVES THROUGH AL/GA. WHILE
THERE HAS BEEN GOOD MODEL CONSISTENCY IS THE GENERAL TRACK OF THE
UPPER AND SURFACE LOWS...THERE ARE STILL 100-200 MILE DIFFERENCES
THAT WILL IMPACT HOW FAR NORTH INTO NC BETTER RAIN COVERAGE WILL
EXTEND. MOST OF THE SHOWERS WILL PASS TO OUR SOUTH THURSDAY NIGHT
AS THE SURFACE LOW DEVELOPS AND MOVES TO NEAR SAVANNAH BY 06-12Z
FRIDAY. HOWEVER...A SHORTWAVE DROPPING SOUTH OUT OF EASTERN CANADA
INTO THE MID-ATLANTIC STATES SHOULD HELP DRAW MOISTURE NORTH INTO
THE VICINITY OF THE 925-850MB FRONT WHICH IS FORECAST TO LIE ACROSS
THE CAROLINAS. MODELS HAVE BEEN SHOWING AN AREA OF INCREASE LOW
LEVEL FGEN DEVELOPING OVER NC LATER FRIDAY NIGHT...SO WHILE THE BEST
SURFACE CONVERGENCE AND UPPER FORCING WILL BE JUST TO OUR SOUTH...WE
SHOULD SEE PRECIP EXPAND AND INTENSIFY NORTHWARD ACROSS SOUTHERN AND
EASTERN NC OVERNIGHT. WE DO NOT EXPECT ANY CONVECTION THURSDAY
NIGHT AS LOW LEVELS WILL BE STABLE...MID LEVEL LAPSE RATES WILL BE
WEAK... AND THE STRONGEST UPPER FORCING WILL BE TO OUR SOUTH.
HOWEVER...IF THE SURFACE LOW TRACKS SLIGHTLY NORTH OF THE CURRENT
FORECAST...THERE COULD BE ENOUGH INSTABILITY ACROSS THE SOUTHERN
PIEDMONT AND SANDHILLS TO SUPPORT A FEW ISOLATED THUNDERSTORMS.
FORECAST POPS ARE ALREADY HIGH ACROSS THE SOUTH AFTER 21Z
THURSDAY...EXPANDING NORTHWARD AFTER 03Z...WHICH SEEMS SUFFICIENT
FOR THE CURRENT FORECAST PACKAGE. LOWS IN THE UPPER 40S.
THE SURFACE LOW SHOULD BE OFF THE SC COAST BY 12Z FRIDAY..WITH
PRECIP ENDING FROM WEST TO EAST DURING THE DAY. THE MSLP GRADIENT
ON THE BACK SIDE OF THE SURFACE LOW WILL BE FAIRLY TIGHT...WITH MOST
MODELS SHOWING A 15-20KT NORTHEASTERLY WIND OVER THE COASTAL PLAIN
FRIDAY MORNING. THE DEPARTING LOW WILL ALSO DRAW DRIER AIR IN FROM
THE NORTH AS WINDS BEGIN TO TURN TO NORTH-NORTHWESTERLY FRIDAY
AFTERNOON. FORECAST SOUNDINGS NOW SHOW MOST OF THE CENTRAL BREAKING
OUT FRIDAY...ALTHOUGH MODELS OFTEN HAVE A TENDENCY TO SCOUR LOW
LEVEL MOISTURE TOO QUICKLY IN THE ABSENCE OF A FRONTAL SYSTEM.
BECAUSE OF THIS...THE HIGH TEMP FORECAST FOR FRIDAY IS SOMEWHAT
UNCERTAIN...BUT IT IS POSSIBLE THAT AREA SIN THE WEST COULD BREAK
OUT AND BE AS WARM IF NOT WARMER THAN AREAS IN THE EAST. WILL
FORECAST HIGHS GENERALLY AROUND 60.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 350 AM WEDNESDAY...
HIGH PRESSURE OVER THE GREAT LAKES WILL BRIEFLY BUILD SOUTH ACROSS
MUCH OF THE EASTERN US THIS WEEKEND...WHILE SEVERAL SHORTWAVES OVER
EASTERN CANADA AND THE NORTHERN US WRAP UP OVER NEW ENGLAND AND LEAD
TO A DEEP TROUGH ALONG THE EAST COAST NEXT WEEK. RAIN CHANCES
APPEAR TO BE LOW BUT ALSO LESS PREDICTABLE DUE TO THE NORTHWESTERLY
FLOW REGIME...ESPECIALLY FROM SUNDAY NIGHT ONWARD. HIGHS WARMING
INTO THE LOW TO MID 70S BY SUNDAY WILL DROP BACK INTO THE 60S FOR
THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 150 PM WEDNESDAY...
PRIMARY IMPACT THROUGH THE 18Z VALID TAF PERIOD WILL BE SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. ALREADY DURING THE EARLY
AFTERNOON SHOWERS WERE DEVELOPING CLOSER TO THE HIGHER ELEVATIONS
AND THE COLD FRONT...AND THESE SHOULD CONTINUE TO DEVELOP AND
INCREASE IN COVERAGE AS THEY MOVE SOUTHEAST DURING THE AFTERNOON.
EXPECT AT ALL TAF SITES POTENTIALLY FOR LOCALLY GUSTY WINDS WITH ANY
THUNDERSTORM AT OR ABOVE 30KT...WITH BRIEFLY IFR CONDITIONS. SUCH
CONDITIONS SHOULD DIMINISH BY 03Z IN CENTRAL NORTH CAROLINA.
OVERNIGHT INTO EARLY THURSDAY...WINDS WILL QUICKLY VEER TO NORTHEAST
BEHIND A COLD FRONT...WITH PATCHY RAIN EXPECTED UNDER CONSIDERABLE
CLOUDS IN THE VFR RANGE.
BEYOND THE 18Z VALID TAF PERIOD...A COLD FRONT WILL LIE JUST SOUTH
OF CENTRAL NORTH CAROLINA BY MID-MORNING THURSDAY. THUNDERSTORMS MAY
DEVELOP ALONG AND NEAR THE FRONT LATE THURSDAY AFTERNOON AND
EVENING...POSSIBLY GETTING CLOSE TO KFAY BUT LIKELY REMAINING JUST
SOUTH OF THERE. BEST POTENTIAL FOR IFR LOW CLOUDS WILL BE THURSDAY
NIGHT INTO EARLY FRIDAY...AND THEN PARTICULARLY TOWARD KFAY...AND
EXPECT THE LIKELIHOOD OF RAIN THURSDAY NIGHT. CONDITIONS GRADUALLY
IMPROVE FRIDAY INTO SATURDAY...WITH PREDOMINANT VFR CONDITIONS OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
112 PM CDT WED APR 4 2012
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
LATEST SATELLITE IMAGERY SHOWS CUMULUS NOW DEVELOPING ACROSS THE
MID STATE WITH TCU/ISO -SHRA FORMING ON THE PLATEAU JUST EAST OF
THE CWA BORDER. SHORT TERM GUIDANCE SUCH AS THE HRRR INDICATES
SOME WIDELY SCATTERED SHRA/TSRA SHOULD DEVELOP AROUND 21Z ACROSS
THE CWA...BUT WITH LESS COVERAGE THAN MODELS HAVE INDICATED IN
PREVIOUS RUNS. WITH THE REDUCED CONFIDENCE IN PRECIP COVERAGE WILL
ONLY SHOW VCTS AT AREA AIRPORTS BETWEEN 21-03Z...WITH TEMPO TSRA
AND MVFR CIGS AT CSV WHERE CONVECTION IS MORE PROBABLE. ANY
CONVECTION TO DIMINISH BY LATE EVENING WITH VFR CONDITIONS UNTIL
08-10Z WHEN GUIDANCE INDICATES SOME PATCHY MVFR FOG AT CKV/BNA AND
MVFR/IFR CIGS/FOG AT CSV.
&&
.PREV DISCUSSION... /ISSUED 957 AM CDT WED APR 4 2012/
UPDATE...SOME MINOR ADJUSTMENT WILL BE MADE. SKIES WERE PARTLY TO
MOSTLY SUNNY THIS MORNING. SUNSHINE WILL PROBABLY PUSH TEMPS A
LITTLE WARMER THAN PREVIOUS FORECAST...SO WILL BUMP THEM UP A
DEGREE OR 2. CLOUDS WILL THICKEN WITH INCREASING RAIN CHANCES THIS
AFTERNOON...MAINLY AFTER 2 PM. COVERAGE WILL BE SCATTERED FOR THE
MOST PART...BUT MORE NUMEROUS OVER THE WEST COUNTIES WHERE DEEPER
MOISTURE WILL BE PRESENT. WE STILL HAVE A SLIGHT RISK FOR SEVERE
STORMS WITH BRIEF WIND GUSTS OR MARGINALLY SEVERE HAIL THE MAIN
CONCERNS.
13
PREV DISCUSSION... /ISSUED 502 AM CDT WED APR 4 2012/
AVIATION 12Z DISCUSSION...
FRONTAL BOUNDARY WILL SAG SOUTHWARD TOWARD THE MID STATE THROUGH
THE TAF PD. AS A RESULT...SCATTERED SHOWERS AND TSTMS WILL DEVELOP
BY THIS AFTERNOON. SOME OF THIS ACTIVITY WILL PERSIST INTO THE
EVENING AS THE UPPER RIDGE AXIS WILL BE EAST OF TN BY LATE EVENING.
OTW...CIGS/VSBYS WILL LOWER TO IFR LEVELS AFT 06Z.
21
PREV DISCUSSION... /ISSUED 312 AM CDT WED APR 4 2012/
DISCUSSION...
WEAK FRONTAL BOUNDARY CONTINUES TO HANG OUT IN THE SOUTHERN OH
VALLEY THIS MORNING...WITH NOISY FLOW ALOFT PROVIDING NUMEROUS
SHORTWAVES/IMPULSES MOVING ABOUT. MODERATE MOISTURE ALREADY
SITUATED OVER THE REGION AND MARGINAL INSTABILITY ALLOWING A FEW
ISO SHOWERS TO POP UP.
SERIES OF SHORTWAVES/IMPULSES WILL CONTINUES TO CROSS THE MID-
SOUTH TODAY/TONIGHT AHEAD OF CLOSED UPPER LOW CURRENTLY IN THE
PLAINS. ADDITIONALLY...WEAK FRONTAL BOUNDARY TO THE NORTH WILL
SINK SOUTH AND SETUP VERY NEAR THE KY/TN BORDER TOWARD 00Z.
INSTABILITY THIS AFTERNOON EXPECTED TO INCREASE AS BOUNDARY
APPROACHES SUCH THAT SHWRS/STORMS SHOULD BECOME QUITE NUMEROUS
WITH SOME STORMS POSSIBLY BECOMING STRONG TO SEVERE.
UPPER LOW MOVES INTO THE MS RIVER VALLEY LATE TONIGHT AND DESPITE
FRONTAL BOUNDARY DROPPING DOWN OVER THE CWA...BRIEF DRY SLOTTING
LIKELY TO REDUCE PCPN...ESPECIALLY 06-12Z. ON THU HOWEVER...SHWR/
STORM ACTIVITY EXPECTED TO GET BACK IN FULL GEAR AS COLD FRONT PASSES
EARLY IN THE DAY FOLLOWED BY UPPER LOW LATE AFTERNOON/EARLY EVE.
THU NIGHT UPPER LOW MOVES WELL EAST AS DOES FRONTAL BOUNDARY...BRINGING
ABOUT DRYING AND END OF PCPN FOR THIS SEGMENT.
UPPER RIDGE BUILDS IN BEHIND UPPER LOW PROVIDING DRY WX FRI/SAT
BUT A WEAK FRONT WILL PASS ON SUN. MOISTURE RETURN AHEAD OF BOUNDARY
WILL BE MINIMAL THUS STORMS ASSOCIATED EXPECTED TO BE ISO. BEHIND
THIS FRONT...UPPER TROUGH WILL PASS MON NIGHT BUT MOISTURE AGAIN
WILL BE VERY LIMITED. NO POPS PLANNED SUN NIGHT-WED AT THIS TIME.
TEMPS WILL GO THROUGH A BIT OF A COOLING TREND. AFTER TODAY THEY
WILL WORK BACK TO MORE NEAR NORMAL...POSSIBLY GOING BELOW NORMAL
EARLY NEXT WEEK.
07
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 PM CDT WED APR 4 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY
318 PM CDT WED APR 4 2012
MAIN EMPHASIS OF FORECAST WILL BE ON FREEZE CONDITIONS THE NEXT
COUPLE OF NIGHTS ALONG WITH LOW DAYTIME RELATIVE LEVELS THURSDAY
AND FRIDAY.
WATER VAPOR IMAGERY AND RUC 500MB ANALYSIS SHOW A HIGHLY AMPLIFIED
MID-LEVEL RIDGE IN PLACE FROM THE NORTHERN PLAINS INTO MANITOBA AND
HUDSON BAY. MEANWHILE...A CLOSED/CUTOFF LOW WAS SLOWLY MOVING EAST
INTO OKLAHOMA. AT THE SURFACE...HIGH PRESSURE WAS CENTERED OVER
WESTERN ONTARIO. DRY/COOL NORTHEAST FLOW WAS RESULTING ACROSS THE
AREA TODAY UNDER SUNNY SKIES WITH TEMPERATURES IN THE UPPER 50S TO
MIDDLE 60S AND DEWPOINTS WAY DOWN IN THE 20S.
04.12Z NAM/GFS SHOWING GOOD AGREEMENT THROUGH FRIDAY...BUT THEN SOME
DIFFERENCES REGARDING THE STRENGTH OF THE MID-LEVEL TROUGH AND
SURFACE COLD FRONT CROP UP SATURDAY. THE 04.09Z SREF WAS GENERALLY
USED FOR THIS TIME FRAME.
FOR TONIGHT THE MAIN STORY WILL BE CLEAR/DRY CONDITIONS LEADING TO A
RAPID DROP OFF IN TEMPERATURES. WITH THE RIDGE AXIS BUILDING
SOUTHWARD INTO THE REGION...LOOKS LIKE WINDS WILL TAPER OFF TO LESS
THAN 5 MPH MOST PLACES WHICH WILL ALLOW TEMPERATURES TO FALL OFF
INTO THE MIDDLE 20S TO MIDDLE 30S. PLAN ON THE COLDEST AIR TO BE
OVER THE FAVORED COLD SPOTS ALONG/NORTH OF THE I-94 CORRIDOR. AS
SUCH...WILL KEEP FREEZE WARNING HOISTED FOR THIS AREA FROM 2 AM
THROUGH 8 AM THURSDAY.
HIGH PRESSURE WILL CONTINUE TO BE THE DOMINATING WEATHER FEATURE
THROUGH FRIDAY WITH PREVAILING DRY CONDITIONS. CONCERN WILL
AGAIN BE ON THE NEED FOR FREEZE HEADLINES LATE THURSDAY NIGHT INTO
FRIDAY MORNING WITH LOWS DIPPING AGAIN INTO THE MIDDLE 20S AND LOWER
30S ACROSS MUCH OF THE AREA...WITH MID/UPPER 20S MORE PREVALENT EAST
OF THE MISSISSIPPI RIVER. WITH THIS IN MIND...WILL BE EXPANDING THE
FREEZE WATCH TO INCLUDE ALL OF THE AREA. SEE WWA SECTION BELOW AND
LATEST FREEZE WATCH STATEMENT FOR DETAILS.
RIDGE STARTS TO BREAK DOWN/MOVE EAST LATE FRIDAY NIGHT THROUGH
SATURDAY AS A FAIRLY VIGOROUS MID-LEVEL TROUGH PUSHES EAST INTO THE
NORTHERN PLAINS/UPPER MISSISSIPPI RIVER REGION. AS STATED
ABOVE...GFS AND NAM ARE DIFFERING AS TO THE STRENGTH OF THIS WAVE
WITH THE GFS LOOKING A BIT STRONGER. THIS HAS A BEARING ON SURFACE
COLD FRONT STRENGTH AND AMOUNT OF MOISTURE TRANSPORT NORTHWARD INTO
THE AREA FOR THE PRODUCTION OF SHOWERS. WITH THIS IN MIND...WILL
MOVE IN 20-30 PERCENT CHANCE OF SHOWERS TO ABOUT THE MISSISSIPPI
RIVER THROUGH FRIDAY MORNING...INCREASING/EXPANDING TO 40 PERCENT
CHANCE OF SHOWERS/ISOLATED THUNDER SATURDAY AFTERNOON ACROSS THE
ENTIRE AREA.
SHOWERS WILL LINGER INTO SATURDAY EVENING...THEN EXIT WITH THE COLD
FRONTAL PASSAGE AFTER MIDNIGHT.
AS FAR AS DAYTIME HIGH TEMPERATURES THURSDAY THROUGH SATURDAY...PLAN
ON 50S THURSDAY AND FRIDAY...WARMING SOME INTO THE UPPER 50S TO
LOWER 60S ON SATURDAY.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
318 PM CDT WED APR 4 2012
04.12Z GFS AND 04.00Z ECMWF IN OVERALL GOOD AGREEMENT THROUGH THE
LONG TERM PERIOD WITH OVERALL DRY/COOLER CONDITIONS. BOTH MODELS SHOW THE AREA
IN BREEZY DRYING WESTERLY FLOW DURING THE DAY SUNDAY IN THE WAKE OF
THE COLD FRONT AND LOW PASSING THROUGH SOUTHERN ONTARIO CANADA.
BREEZY/COOLER NORTHWEST FLOW INVADES THE AREA MONDAY THROUGH TUESDAY
AS HIGH PRESSURE BUILDS SOUTHWARD INTO THE PLAINS/UPPER MISSISSIPPI
RIVER REGION AND DEEP LOW PRESSURE ANCHORS OVER QUEBEC. SOME WARMING
THEN EXPECTED ON WEDNESDAY AS THE AXIS OF THE SURFACE RIDGE SHIFTS
EAST OF THE REGION AND HEIGHTS BUILD ALOFT. TEMPERATURE-WISE...LOOK
FOR HIGHS IN THE MID-UPPER 50S SUNDAY...COOLING INTO THE UPPER 40S
TO LOWER 50S MONDAY/TUESDAY...AND THEN BACK INTO THE MID-UPPER 50S
WEDNESDAY.
&&
.AVIATION...THIS AFTERNOON AND TONIGHT
1215 PM CDT WED APR 4 2012
VFR CONDITIONS THROUGHOUT FORECAST PERIOD WITH HIGH PRESSURE
REMAINING IN CONTROL AND DRY LOW LEVEL EAST TO NORTHEAST FLOW.
EASTWARD DRIFT OF UPPER LOW WILL KEEP EVEN HIGH CLOUDS MAINLY
CONFINED SOUTH OF AVIATION CORRIDOR.
&&
.FIRE WEATHER...THURSDAY THROUGH FRIDAY
318 PM CDT WED APR 4 2012
HUDSON BAY HIGH WILL PUMP A VERY DRY AIRMASS INTO THE REGION
THURSDAY THROUGH FRIDAY. LOOK FOR AFTERNOON MINIMUM RH READINGS IN THE
20-25 PERCENT RANGE THURSDAY...MODERATING A FEW PERCENTAGE POINTS
INTO THE MID 20S FRIDAY AFTERNOON. WINDS LOOK GENERALLY ON THE
LIGHTER SIDE THURSDAY OUT OF THE EAST SOMEWHERE IN THE 5-12 MPH
RANGE WITH SOME GUSTS AROUND 15 MPH. WINDS ARE THEN EXPECTED TO
INCREASE OUT OF THE SOUTHEAST ON FRIDAY...ESPECIALLY WEST OF THE
MISSISSIPPI RIVER FRIDAY AS THE HIGH BEGINS TO PUSH EAST INTO THE
GREAT LAKES REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 PM CDT WED APR 4 2012
WI...FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
WIZ017-029-032>034-041>044-053>055-061.
FREEZE WARNING FROM 2 AM TO 8 AM CDT THURSDAY FOR WIZ017-029-034-
042>044.
MN...FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
MNZ079-086>088-094>096.
IA...FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...SHEA
FIRE WEATHER...DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
233 PM CDT WED APR 4 2012
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
CENTERED OVER NORTHERN MANITOBA WITH A RIDGE AXIS EXTENDING SOUTH
OVER THE WESTERN GREAT LAKES. ONLY THIN CIRRUS IS PREVENTING A
CLEAR DAY ACROSS THE FORECAST AREA THIS AFTERNOON. PRETTY QUIET
UPSTREAM AS WELL...THANKS TO A BLOCKING MID-LEVEL RIDGE CENTERED
OVER THE NORTHERN PLAINS AND CENTRAL CANADA. SOME COLDER AIR AND
STRATO-CU ARE WORKING SE OVER EASTERN LAKE SUPERIOR...BUT SHOW NO
SIGNS OF PUSHING WESTWARD DESPITE THE COLD ADVECTION. WITH A
SEASONABLE BUT DRY AIRMASS IN PLACE...LOW TEMPS TONIGHT AND
HUMIDITIES TOMORROW ARE THE MAIN FORECAST CONCERNS.
TONIGHT...HUDSON BAY HIGH PRESSURE WILL BE BUILDING SOUTHEAST ACROSS
NORTHERN ONTARIO AND NOSING SOUTHWARD ACROSS THE NORTHERN GREAT
LAKES. THE AIRMASS IS NOT ALL THAT DIFFERENT COMPARED TO LAST
NIGHT...THOUGH WE ARE STARTING OUT A TAD DRIER OVER CENTRAL AND
NORTHEAST WISCONSIN COMPARED TO THIS TIME YESTERDAY AFTERNOON.
1000-850MB WIND SPEEDS WILL BE SLIGHTLY LOWER OVER N-C WISCONSIN
THAN LAST NIGHT...WHICH SHOULD LEAD TO DECOUPLING. NORTHEAST
WISCONSIN WILL CONTINUE TO HAVE NE WINDS FUNNELED DOWN THE BAY AND
ONSHORE ALONG THE LAKE MICHIGAN SHORELINE. THIS SHOULD KEEP THE BL
OVER NE WISCONSIN MIXY ENOUGH TO PREVENT TEMPS FROM FALLING TO
FREEZE WARNING CRITERIA (28F AND BELOW). BUT DO EXPECT TEMPS TO BE
A DEGREE OR TWO COOLER THAN LAST NIGHT DUE TO SUBTLE LOW LEVEL COLD
ADVECTION AND SLIGHTLY DRIER AIR AT THE SURFACE. AS A
RESULT...FORECAST MIN TEMPS SUGGEST THE INHERITED FREEZE WARNING
HEADLINES DO NOT NEED TO BE EXPANDED FURTHER EAST THAN CURRENTLY
COMPRISED...SO WILL LEAVE HEADLINES BE. LOWS RANGING FROM THE LOWER
20S NORTH TO LOWER 30S SOUTHEAST.
THURSDAY...SURFACE RIDGE AXIS WILL REMAIN CENTERED ACROSS EASTERN
WISCONSIN. THE AIRMASS CHANGES LITTLE TOMORROW...THOUGH IS SLIGHTLY
COLDER DUE TO THE COLD ADVECTION FROM TONIGHTS PERIOD. NORTHEAST
WINDS WILL CONTINUE TO KEEP NE WISCONSIN COOLER THAN CENTRAL
WISCONSIN...AND HIGHS WILL RANGE FROM THE MID 50S WEST TO THE MIDDLE
40S EAST. HUMIDITY LEVELS WILL AGAIN FALL SLIGHTLY BELOW CRITICAL
CRITERIA OVER NORTH-CENTRAL WISCONSIN...WITH COOLER AIR OFFSETTING
LOWER DEWPOINTS IN THE AFTERNOON.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY...MAIN FCST CONCERNS
ARE THE POTENTIAL FOR FROST/FREEZE CONDITIONS ON THURSDAY NIGHT...CONTINUED
VERY DRY CONDITIONS CONTRIBUTING TO HIGH FIRE DANGER ON FRIDAY...AND
PCPN CHANCES LATER SATURDAY INTO SATURDAY NIGHT.
A HUDSON BAY HIGH WILL BRING VERY DRY CONDITIONS TO THE REGION THROUGH
FRIDAY. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPS TO PLUMMET ON
THURSDAY NIGHT...LEADING TO ANOTHER HARD FREEZE FOR AREAS WEST OF THE
FOX VALLEY AND LAKESHORE. WILL KEEP THE CURRENT AREAL COVERAGE FOR THE
FREEZE WATCH...BUT IT MAY NEED TO BE EXPANDED WITH SUBSEQUENT FCSTS...
ESPECIALLY INTO SOUTHERN MARINETTE AND OCONTO COUNTIES.
ON FRIDAY...MIXING THROUGH 850 MB SUPPORTS HIGH TEMPS IN THE MID TO
UPPER 50S AWAY FROM THE LAKE. DEW POINTS SHOULD CRASH INTO THE TEENS
AND LOWER 20S IN THE SANDY SOIL AREAS...LEADING TO ANOTHER DAY WITH
RELATIVE HUMIDITY IN THE 15-25 PERCENT RANGE. THIS WILL CONTRIBUTE
TO ANOTHER DAY OF HIGH FIRE DANGER.
TEMPERATURES SHOULD CLIMB A BIT ON FRIDAY NIGHT AS THE HIGH SHIFTS
EAST AND WINDS GRADUALLY VEER SOUTH. DID LOWER MIN TEMPS A LITTLE BIT
TO ACCOUNT FOR LINGERING DRY AIR.
A COLD FRONT AND ASSOCIATED UPPER TROF/LOW WILL APPROACH LATER ON
SATURDAY...THEN MOVE THROUGH THE FORECAST AREA SATURDAY NIGHT...
SO HAVE MAINTAINED THE CHC POPS DURING THIS PERIOD. INSTABILITY
PARAMETERS ARE UNIMPRESSIVE...BUT WITH 700-500 MB LAPSE RATES IN
THE 6-7 C/KM RANGE...DECIDED TO KEEP THE MENTION OF ISOLD TSTMS.
ORIGINALLY THOUGHT THAT THE GFS WAS TOO ROBUST AND TOO FAR SOUTH
WITH THE UPPER LOW ARRIVING FROM THE NORTHERN PLAINS LATE IN THE
WEEKEND...BUT THE 12Z ECMWF HAS STRONGLY TRENDED THAT DIRECTION...
AND BRINGS A SLOWLY WEAKENING UPPER LOW THROUGH WI SUNDAY AND
SUNDAY NIGHT. THIS GOES AGAINST THE TRENDS OF MOST MODELS AND
ENSEMBLES...SO WILL KEEP A DRY FCST INTACT FOR NOW. WILL NEED TO
KEEP AN EYE ON THIS FOR SUBSEQUENT FCSTS.
NORTHWEST CANADIAN HIGH PRESSURE WILL BRING DRY WEATHER TO THE
REGION TUESDAY INTO WEDNESDAY.
TEMPERATURES WILL CONTINUE TO AVERAGE NEAR OR A BIT ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION...CANADIAN HIGH PRESSURE WILL REMAIN ACROSS THE REGION
THROUGH FRIDAY...LEADING TO VFR CONDITIONS AT THE TAF SITES. THERE
IS A VERY SMALL CHANCE THAT HIGH END MVFR CIGS REACH FAR NE
WISCONSIN LATE TONIGHT INTO THURSDAY MORNING. WILL MENTION
POSSIBILITY TO LATER SHIFTS.
MPC
&&
.MARINE...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO THE
STRENGTHENING OF NORTHEAST WINDS OVER NORTHERN LAKE MICHIGAN THIS
EVENING. WITH 25-30 KTS AT 950-925MB...INSTABILITY IS MARGINAL FOR
SMALL CRAFT WIND AND WAVES DEVELOPING. WAVES WILL BE INCREASING
INTO THE HIGHER END OF THE 2-4 FT RANGE OVERNIGHT...BUT LOOK TO FALL
SLIGHTLY SHORT OF SMALL CRAFT CRITERIA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY MORNING FOR
WIZ005-010>013-018>021-030-031-035>037-045.
FREEZE WARNING FROM 2 AM TO 8 AM CDT THURSDAY FOR WIZ005-010>013-
018>021-030-031-035>037-045.
&&
$$
MPC/KIECKBUSCH