Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/06/12
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 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 SACRAMENTO CA
403 PM PDT THU APR 5 2012
.SHORT TERM DISCUSSION...
INSTABILITY FROM A COLD TROUGH AND A SHORTWAVE PASSING THROUGH THE
AREA ARE GENERATING CONVECTIVE SHOWERS OVER THE MOUNTAINS. THERE
MAY BE A FEW ISOLATED THUNDERSTORMS BEFORE SUNSET. SNOW SHOWERS
ARE LIKELY ABOVE 4000 FEET AND LOCALLY LOWER. SNOW ACCUMULATIONS
SHOULD BE GENERALLY LIGHT WITH A COUPLE INCHES POSSIBLE OVER THE
HIGHER ELEVATIONS. THE HRRR AND WRF MODELS HAVE A GOOD GENERAL
HANDLE ON THE LOCATION OF THE CONVECTION AND SHOW MUCH OF THE
ACTIVITY ENDING BY AROUND 10 PM. A FEW SNOW SHOWERS MAY CONTINUE
SOUTH OF HIGHWAY 50 OVERNIGHT.
LOWS WERE QUITE COOL THIS MORNING. A RECORD OF 35 WAS TIED AT
SACRAMENTO EXECUTIVE AIRPORT. IT WILL BE UNSEASONABLY COOL ONCE
AGAIN ON FRIDAY MORNING WITH LOWS APPROACHING RECORD LEVELS. THE
RECORD LOW TOMORROW FOR DOWNTOWN SACRAMENTO IS 35...37 AT
STOCKTON...AND 34 AT MODESTO. SOME PATCHY FROST IS POSSIBLE IN
PORTIONS OF THE SOUTHERN/CENTRAL SACRAMENTO VALLEY...DELTA AND
THE VALLEYS OF LAKE COUNTY.
RIDGING WILL BRING DRY AND WARMER WEATHER FOR FRIDAY AND SATURDAY.
HIGHS SATURDAY WILL REACH THE LOW 70S FOR SOME LOCATIONS IN THE
VALLEY. AN UPPER LOW WILL APPROACH THE REGION ON SUNDAY WITH A
FRONTAL BAND SPREADING SOME PRECIPITATION INTO THE COASTAL
MOUNTAINS AND NORTHERN SACRAMENTO VALLEY. THIS SYSTEM WILL
GRADUALLY TRACK INLAND ON MONDAY BUT MAY REMAIN FAR ENOUGH WEST
THAT THE SIERRA SEES LITTLE OR NO PRECIPITATION. TEMPERATURES
OVERALL SHOULD REMAIN NEAR NORMAL LEVELS. EK
.EXTENDED DISCUSSION (MONDAY THROUGH THURSDAY)
THERE IS ABOVE NORMAL CONFIDENCE THROUGH THE DAY 5 PERIOD...THEN
NORMAL CONFIDENCE FOR DAYS 6/7...AND IN SHORT...INCREASING PRECIP
CHANCES DURING THIS TIME PERIOD. THE FORECAST SHOULD SEEM
STRAIGHTFORWARD EXCEPT FOR THE FACT "THE DEVIL IS IN THE DETAILS"
AND THERE IS NOT ONE...BUT TWO CLOSED LOWS THAT ARE FORECAST TO
AFFECT INTERIOR NORCAL DURING THE TIME PERIOD. THE FIRST CLOSED LOW
(AND WHEN THE MODEL CONFIDENCE IS ABOVE NORMAL ON MON) ROTATES OFF
THE PAC NW COAST AND DEEPENS THE TROF OFF THE CA COAST MAINLY W OF
130W. THIS WILL BACK THE FLOW TO A MORE SLY COMPONENT OVER NORCAL
SHIFTING THE FRONTAL BAND WWD. THIS MAY KEEP ALL THE PRECIP W OF OUR
FORECAST AREA...BUT WE WILL CONTINUE LOW TO MODERATE CHANCE POPS
ACROSS THE WRN PORTION OF THE FORECAST AREA. HENCE "THE DEVIL IN THE
DETAILS"...BECAUSE IT MAY NOT RAIN AT ALL.
THIS FIRST LOW WILL FILL/WEAKEN WITH THE 2ND UPSTREAM LOW ACTING AS
A KICKER AND KICKING THE TROF INLAND MAINLY ON WED. AGAIN...MORE
DETAILS...BUT WE HAVE GENERALLY TRENDED THE POPS HIGHER TUE NITE/WED
AND INTO THE CHANCE TO LIKELY CATEGORY OVER THE SIERNEV. BY THU...
THE 2ND LOW IS FORECAST TO BE CLOSE ENOUGH TO NORCAL FOR SOME WAA
PRECIP TO SPREAD INTO THE INTERIOR...IF NOT THE FRONTAL BAND
ITSELF DEPENDING ON THE MODEL. THE NCEP GLOBAL ENSEMBLE RMOP
(RELATIVE MEASURE OF PREDICTABILITY) INDICATES A HIGH MEASURE OF
PREDICTABILITY WITH THE TROF OFF THE CA COAST ON THU LENDING
CREDENCE TO TRENDING POPS HIGHER INTO DAY 7. THE 2ND LOW MAY
PARALLEL THE CA COAST FRI/SAT TO CONTINUE UNSETTLED WX AT LEAST
INTO THE START OF NEXT WEEKEND. THE 2ND LOW WILL BE A
COLDER...PROBABLY WETTER SYSTEM...SO SNOW LEVELS AND TEMPS HAVE
BEEN ADJUSTED (LOWERED) ACCORDINGLY. JHM
&&
.AVIATION...
UPPER LEVEL TROUGH SHIFTS TO THE EAST TONIGHT WITH A RIDGE OF HIGH
PRESSURE BUILDING OVER THE AREA FRIDAY. VFR CONDITIONS IN THE
VALLEY EXPECTED THROUGH FRIDAY WITH FEW-SCT CUMULUS UNTIL 03Z.
SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS BRINGING
AREAS OF MVFR AND LOCAL IFR CONDITIONS OVER THE MOUNTAINS. SNOW
LEVELS AROUND 3500 FEET. SHOWERS ARE EXPECTED TO DIMINISH OVER THE
MOUNTAINS FRIDAY MORNING.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
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 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 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
NWS BOISE ID
859 PM MDT THU APR 5 2012
.DISCUSSION...TRIMMED DOWN POPS FOR THE REMAINDER OF THIS EVENING AS
SHOWERS ARE WINDING DOWN...FOR THE MOST PART. ONLY AREAS WHICH
APPEAR TO HAVE SHOWERS CONTINUING ARE ALONG OUTER EDGES OF THE
CWA...INCLUDING NEAR THE NEVADA BORDER AND WEST/NORTH OF
BURNS...BAKER CITY...AND MCCALL. UPPER LOW REMAINS ANCHORED TO OUR
WEST THIS EVENING WILL WILL SLOWLY MIGRATE EASTWARD OVERNIGHT.
ORGANIZED PRECIP WILL DEVELOP TO OUR EAST AND NORTHEAST...BUT SOME
MOISTURE WILL WRAP BACK INTO THE BOISE/WEST CENTRAL MTNS...MAINLY
EAST OF MCCALL AND IDAHO CITY...LATE TONIGHT THROUGH FRIDAY. DRIER
AIR WILL START TO WORK UP FROM THE SOUTH LATE FRIDAY.
&&
.AVIATION...MAINLY VFR. EXCEPTIONS...18Z FRIDAY TO 00Z SATURDAY
ISOLATED TO SCATTERED MVFR MOUNTAIN SNOW SHOWERS OVER EASTERN OREGON
AND SOUTH OF THE SNAKE RIVER VALLEY...AND SCATTERED TO NUMEROUS
MVFR/LOCAL IFR SNOW SHOWERS OVER THE CENTRAL IDAHO MOUNTAINS.
SURFACE WINDS...WEST TO NORTHWEST 5-15 KTS INCREASING TO 10-20 KTS
BY 18Z. WINDS ALOFT...NORTHWEST 10-15 KTS AT 10K FEET MSL.
WEEKEND OUTLOOK...VFR UNDER MOSTLY CLEAR SKIES.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH SATURDAY...UPPER LEVEL LOW AXIS
CONTINUES TO OUR WEST WITH A MOIST IMPULSE PINWHEELING PRECIPITATION
INTO SE OREGON. MESONET AMOUNTS OF 0.10 OR GREATER HAVE BEEN NEAR
THE SW HARNEY-LAKE COUNTY LINE. SURFACE FLOW WILL CONTINUE FROM THE
NW WHICH WILL SUPPORT TERRAIN ENHANCEMENT OVER SE OREGON AND OWYHEE
COUNTY THROUGH MIDNIGHT...WITH MOST OF THE P-TYPE BEING SNOW
SHOWERS. LIGHT SHOWERS WERE ALSO POSSIBLE UNDER RADAR ECHOES AND/OR
BRIGHTER/COLDER CLOUD TOPS IN CENTRAL IDAHO...THE SOUTHERN SAWTOOTH
MOUNTAINS AND ACROSS BAKER COUNTY. THESE NORTHERN AREAS WERE SEEING
A FEW HUNDREDTHS REPORTED BUT BY RAWS. RUC IS NOT SHOWING MORE THAN
100 CAPE IN THE CWFA AND LATEST NAM12 SOUNDING AT BOISE IS CAPPED SO
DID NOT ADD IN THUNDERSTORMS AFTER 00Z BUT LEFT THEM IN ACROSS
MAINLY OREGON AND THE PAYETTE NATIONAL FOREST/OWYHEE MOUNTAINS THIS
AFTERNOON. REMAINING COOL WITH HIGHS 10 DEGREES BELOW NORMAL THROUGH
FRIDAY AND TWO MORE FROSTY NIGHTS IN THE VALLEY BEFORE TEMPERATURES
REBOUND TO NEAR NORMAL SATURDAY AS THE WELL ADVERTISED RIDGE STARTS
TO PROGRESS OVER THE AREA.
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...SIGNIFICANT WARMING
STILL ON TRACK FOR THIS WEEKEND THROUGH TUESDAY AS AN UPPER LEVEL
RIDGE BUILDS IN OVER THE WESTERN US. THE RIDGE BECOMES HIGHLY
AMPLIFIED...PEAKING ON MONDAY...IN RESPONSE TO A CYCLONE OVER
EASTERN NOAM DEEPENING THROUGH THE PERIOD. TEMPERATURES LOOK TO BE
10-15 DEGREES ABOVE NORMAL THROUGH TUESDAY...WITH THE WARMEST TEMPS
COMING MONDAY. THE UPPER TREASURE VALLEY COULD REACH 20 DEGREES
ABOVE NORMAL WITH STRONG ENOUGH DOWNSLOPE WARMING IN A SOUTHEAST
WIND. HEIGHTS BEGIN TO COME DOWN LATE TUESDAY AHEAD OF A SHORTWAVE
TROUGH MOVING ONSHORE. THIS TROUGH WILL AFFECT THE AREA THROUGH THE
END OF THE FORECAST PERIOD...BRINGING A CHANCE OF RAIN SHOWERS TO
MOST LOCATIONS AND LOWERING TEMPS BACK DOWN NEAR NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....JT
PREV SHORT TERM...VM
PREV LONG TERM....CB/WH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
946 PM CDT THU APR 5 2012
.DISCUSSION...
258 PM CDT
THE MAIN FORECAST CONCERNS WILL BE THE FREEZING CONDITIONS TONIGHT
ACROSS MOST OF THE AREA.
SKIES ARE BECOMING MOSTLY CLEAR ACROSS NORTHERN ILLINOIS THIS
AFTERNOON AS THE MAIN AREA OF HIGHER LEVEL CLOUDINESS SHIFTS SOUTH
ALONG WITH THE MID LEVEL CIRCULATION ACROSS EAST CENTRAL AR. SURFACE
HIGH PRESSURE CENTERED OVER ONTARIO...EARLY THIS AFTERNOON...WILL
BEGIN TO BUILD SOUTHWARD ACROSS THE WESTERN GREAT LAKES TONIGHT.
THIS LOOKS TO SET THE STAGE FOR A WIDESPREAD FREEZE ACROSS THE AREA
OVERNIGHT TONIGHT AS A DRY AND COOL AIR MASS HAS SET UP ACROSS
NORTHERN ILLINOIS AND NORTHWESTERN INDIAN. IT APPEARS WINDS WILL NOT
BECOME TOTALLY CALM OVERNIGHT. INSTEAD IT APPEARS THAT A LIGHT
NORTHEASTERLY FLOW AT OR UNDER 5 KT WILL CONTINUE FOR MUCH OF THE
NIGHT AS WE REMAIN JUST SOUTH OF THE CENTER OF THE HIGH. THIS MAY
LIMIT THE AMOUNT OF FROST ACCRETION...EXCEPT FOR PROTECTED AREAS.
I AM EXPECTING TEMPERATURES TO DROP INTO THE UPPER 20S ACROSS NORTH
CENTRAL ILLINOIS FROM THE FOX VALLEY WESTWARD. THIS IS WHERE THE
COLDEST TEMPERATURES SHOULD OCCUR. I HAVE CHOSEN TO UPGRADE THE
FREEZE WATCH TO A WARNING FOR THE ENTIRE AREA. WARMER CONDITIONS
WILL PREVAIL ACROSS THE IMMEDIATE CHICAGO AREA...WITH TEMPERATURES
LIKELY ONLY BOTTOMING OUT IN THE THE UPPER 30S TO NEAR 40 DOWNTOWN.
IN SPITE OF THIS...I HAVE CHOSEN TO INCLUDE COOK COUNTY IN THE
FREEZE WARNING FOR AREAS ACROSS NORTHWESTERN SECTIONS OF THE COUNTY
WHERE NEAR TO JUST BELOW FREEZING CONDITIONS LOOK LIKELY.
COOL CONDITIONS WILL CONTINUE ON FRIDAY AS THE SURFACE HIGH SLOWLY
SHIFTS SOUTHWARD ACROSS LAKE MICHIGAN. ANOTHER COLD NIGHT LOOKS TO
SET UP FRIDAY NIGHT...WITH FREEZING TEMPERATURES AGAIN QUITE
POSSIBLE AS LIGHT WINDS SET UP ACROSS NORTHWESTERN INDIANA AND
NORTHEASTERN ILLINOIS.
A WARM UP LOOKS TO OCCUR ON SATURDAY AS A POTENT STORM SYSTEM MOVES
ACROSS NORTH DAKOTA AND MANITOBA. THIS SHOULD SETUP SOUTHERN FLOW
ACROSS THE AREA AND LEAD TO TEMPERATURES REBOUNDING BACK INTO THE
60S AREA WIDE. IT APPEARS THERE IS STILL A CHANCE OF SOME SHOWERS
AND POSSIBLY SOME THUNDERSTORMS SATURDAY NIGHT AS A COOL FRONT
PUSHES ACROSS THE AREA. MEAGER MOISTURE RETURN AND LARGE SCALE
FORCING FOR ASCENT THIS FAR SOUTH SHOULD LIMIT THE OVERALL THREAT
FOR THUNDERSTORMS. HOWEVER...I CANNOT RULE OUT A FEW SHOWERS
AFFECTING THE AREA DURING THIS TIME. THEREFORE I CONTINUED THE
CHANCE MENTION ON SATURDAY NIGHT.
IT APPEARS THAT NOT MUCH COLDER AIR WILL FILTER ACROSS THE REGION
BEHIND THE INITIAL FRONTAL PASSAGE SATURDAY NIGHT.
THEREFORE...SUNDAY APPEARS TO BE ANOTHER FAIRLY MILD DAY...WITH
TEMPERATURES ONCE AGAIN GETTING INTO THE 60S IN MOST AREAS WITH
WESTERLY FLOW.
THE MID LEVEL SHORT WAVE ACROSS THE NORTHERN PLAINS IS FORECAST TO
DIG ACROSS THE GREAT LAKES REGION EARLY NEXT WEEK. AS THIS
OCCURS...ANOTHER STRONGER COLD FRONT WILL PUSH ACROSS THE AREA BY
MONDAY MORNING. THIS FRONT WILL USHER IN A MUCH COOLER AIR MASS. SO
THE MAIN STORY EARLY NEXT WEEK WILL BE THE COOLER WEATHER. HIGH
TEMPERATURES WILL LIKELY BE LIMITED TO THE UPPER 40S TO THE LOWER
50S...AND OVERNIGHT LOW TEMPERATURES LOOK TO DIP BELOW
FREEZING...ESPECIALLY ON WEDNESDAY NIGHT AS A SURFACE RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE AREA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* NO CONCERNS OVERNIGHT
SHEA
//DISCUSSION...UPDATED 00Z...
STILL A LITTLE CONCERN THAT THERE MAY BE SOME LAKE EFFECT CLOUD
DEVELOPMENT OVERNIGHT. RUC SOUNDINGS AND 925 MB RH FIELDS REALLY
SATURATE AROUND THE 1.5 KFT LAYER. WHILE THERE IS A LITTLE LAKE
INSTABILITY THAT COULD ALLOW A FEW CLOUDS TO POP...WOULDNT EXPECT
IT TO BE ANY THICKER THAN FEW...BUT ALSO BELIEVE THAT THE RUC IS
REALLY OVERDOING THIS FEATURE AND THAT THE ATMOSPHERE WILL BE FAR
TO DRY TO SUPPORT ANY CLOUDS AND NAM/HRRR TRENDS CONTINUE TO
SUPPORT THIS. WILL LEAVE KEEP ANY MENTION OF ANY CLOUD COVER OUT
OF THE 00Z PACKAGE AT THIS POINT.
OTHERWISE GUSTY CONDITIONS WILL SLOWLY ABATE OVERNIGHT AND FALL TO
AROUND 5-7 KTS. WINDS WILL THEN TURN EASTERLY AND EVENTUALLY
SOUTHEASTERLY AS HIGH PRESSURE SHIFTS OFF TO THE EAST. WILL
WITHHOLD ANY MENTION OF GUSTS FRIDAY AFTERNOON...AS FLOW THROUGH
THE MIXED LAYER IS PROGGED TO BE ONLY SLIGHTLY HIGHER THAN SURFACE
FLOW. WOULD EXPECT WINDS TO BE AROUND THE 5 KT RANGE WITH A FEW
OCCASIONAL MID TEEN GUSTS.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...CHANCE OF SHRA/TSRA LATE...OTHERWISE VFR
* SUNDAY...VFR
* MONDAY...CHANCE OF SHRA...OTHERWISE VFR
* TUESDAY...MVFR POSSIBLE
* WEDNESDAY...VFR
SHEA
&&
.MARINE...
207 PM CDT
HIGH PRESSURE CENTERED OVER ONTARIO AND THE NORTHERN LAKES WILL
SLIDE SLOWLY SOUTHEAST THROUGH FRIDAY...ALLOWING NORTHEAST WINDS
CURRENTLY GUSTING TO 20-25 KTS TO SLOWLY DECREASE ACROSS LAKE
MICHIGAN AS THE SOUTHERN PERIPHERY OF THE SURFACE RIDGE BUILDS
ACROSS THE LAKE. THE RIDGE WILL MOVE EAST OF THE LAKE BY EARLY
SATURDAY...ALLOWING WINDS TO BECOME SOUTH-SOUTHEAST AND INCREASE
INTO THE 15-20 KT RANGE ESPECIALLY ON THE WEST SIDE OF THE LAKE BY
SATURDAY AFTERNOON AS LOW PRESSURE LIFTS FROM THE NORTHERN HIGH
PLAINS INTO SOUTHERN MANITOBA. A COLD FRONT ARCING SOUTH FROM THIS
LOW WILL PUSH EAST ACROSS THE LAKE SATURDAY NIGHT.
THE CANADIAN LOW WILL REDEVELOP/COMBINE WITH ANOTHER AREA OF LOW
PRESSURE OVER NEW ENGLAND AND THE ST LAWRENCE VALLEY SUNDAY AND
SUNDAY NIGHT...WHILE STRONG HIGH PRESSURE DEVELOPS OVER CENTRAL
CANADA. THIS WILL RESULT IN A PUSH OF COLDER AIR AND A PERIOD OF
BLUSTERY NORTH-NORTHWEST WINDS OF 25-30 KTS ACROSS THE LAKE EARLY
NEXT WEEK.
FOR THE ILLINOIS/NORTHWEST INDIANA NEARSHORE WATERS...WILL BE
EXTENDING SMALL CRAFT ADVISORIES INTO FRIDAY MORNING...AS PROLONGED
PERIOD OF SLOWLY DIMINISHING NORTH-NORTHEAST FLOW WILL MAINTAIN
WAVES 4 FT OR GREATER THROUGH THAT TIME.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...1 AM FRIDAY TO 8 AM FRIDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...1 AM
FRIDAY TO 8 AM FRIDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
702 PM CDT THU APR 5 2012
.DISCUSSION...
258 PM CDT
THE MAIN FORECAST CONCERNS WILL BE THE FREEZING CONDITIONS TONIGHT
ACROSS MOST OF THE AREA.
SKIES ARE BECOMING MOSTLY CLEAR ACROSS NORTHERN ILLINOIS THIS
AFTERNOON AS THE MAIN AREA OF HIGHER LEVEL CLOUDINESS SHIFTS SOUTH
ALONG WITH THE MID LEVEL CIRCULATION ACROSS EAST CENTRAL AR. SURFACE
HIGH PRESSURE CENTERED OVER ONTARIO...EARLY THIS AFTERNOON...WILL
BEGIN TO BUILD SOUTHWARD ACROSS THE WESTERN GREAT LAKES TONIGHT.
THIS LOOKS TO SET THE STAGE FOR A WIDESPREAD FREEZE ACROSS THE AREA
OVERNIGHT TONIGHT AS A DRY AND COOL AIR MASS HAS SET UP ACROSS
NORTHERN ILLINOIS AND NORTHWESTERN INDIAN. IT APPEARS WINDS WILL NOT
BECOME TOTALLY CALM OVERNIGHT. INSTEAD IT APPEARS THAT A LIGHT
NORTHEASTERLY FLOW AT OR UNDER 5 KT WILL CONTINUE FOR MUCH OF THE
NIGHT AS WE REMAIN JUST SOUTH OF THE CENTER OF THE HIGH. THIS MAY
LIMIT THE AMOUNT OF FROST ACCRETION...EXCEPT FOR PROTECTED AREAS.
I AM EXPECTING TEMPERATURES TO DROP INTO THE UPPER 20S ACROSS NORTH
CENTRAL ILLINOIS FROM THE FOX VALLEY WESTWARD. THIS IS WHERE THE
COLDEST TEMPERATURES SHOULD OCCUR. I HAVE CHOSEN TO UPGRADE THE
FREEZE WATCH TO A WARNING FOR THE ENTIRE AREA. WARMER CONDITIONS
WILL PREVAIL ACROSS THE IMMEDIATE CHICAGO AREA...WITH TEMPERATURES
LIKELY ONLY BOTTOMING OUT IN THE THE UPPER 30S TO NEAR 40 DOWNTOWN.
IN SPITE OF THIS...I HAVE CHOSEN TO INCLUDE COOK COUNTY IN THE
FREEZE WARNING FOR AREAS ACROSS NORTHWESTERN SECTIONS OF THE COUNTY
WHERE NEAR TO JUST BELOW FREEZING CONDITIONS LOOK LIKELY.
COOL CONDITIONS WILL CONTINUE ON FRIDAY AS THE SURFACE HIGH SLOWLY
SHIFTS SOUTHWARD ACROSS LAKE MICHIGAN. ANOTHER COLD NIGHT LOOKS TO
SET UP FRIDAY NIGHT...WITH FREEZING TEMPERATURES AGAIN QUITE
POSSIBLE AS LIGHT WINDS SET UP ACROSS NORTHWESTERN INDIANA AND
NORTHEASTERN ILLINOIS.
A WARM UP LOOKS TO OCCUR ON SATURDAY AS A POTENT STORM SYSTEM MOVES
ACROSS NORTH DAKOTA AND MANITOBA. THIS SHOULD SETUP SOUTHERN FLOW
ACROSS THE AREA AND LEAD TO TEMPERATURES REBOUNDING BACK INTO THE
60S AREA WIDE. IT APPEARS THERE IS STILL A CHANCE OF SOME SHOWERS
AND POSSIBLY SOME THUNDERSTORMS SATURDAY NIGHT AS A COOL FRONT
PUSHES ACROSS THE AREA. MEAGER MOISTURE RETURN AND LARGE SCALE
FORCING FOR ASCENT THIS FAR SOUTH SHOULD LIMIT THE OVERALL THREAT
FOR THUNDERSTORMS. HOWEVER...I CANNOT RULE OUT A FEW SHOWERS
AFFECTING THE AREA DURING THIS TIME. THEREFORE I CONTINUED THE
CHANCE MENTION ON SATURDAY NIGHT.
IT APPEARS THAT NOT MUCH COLDER AIR WILL FILTER ACROSS THE REGION
BEHIND THE INITIAL FRONTAL PASSAGE SATURDAY NIGHT.
THEREFORE...SUNDAY APPEARS TO BE ANOTHER FAIRLY MILD DAY...WITH
TEMPERATURES ONCE AGAIN GETTING INTO THE 60S IN MOST AREAS WITH
WESTERLY FLOW.
THE MID LEVEL SHORT WAVE ACROSS THE NORTHERN PLAINS IS FORECAST TO
DIG ACROSS THE GREAT LAKES REGION EARLY NEXT WEEK. AS THIS
OCCURS...ANOTHER STRONGER COLD FRONT WILL PUSH ACROSS THE AREA BY
MONDAY MORNING. THIS FRONT WILL USHER IN A MUCH COOLER AIR MASS. SO
THE MAIN STORY EARLY NEXT WEEK WILL BE THE COOLER WEATHER. HIGH
TEMPERATURES WILL LIKELY BE LIMITED TO THE UPPER 40S TO THE LOWER
50S...AND OVERNIGHT LOW TEMPERATURES LOOK TO DIP BELOW
FREEZING...ESPECIALLY ON WEDNESDAY NIGHT AS A SURFACE RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE AREA.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NORTHEAST WIND GUSTS
SHEA
//DISCUSSION...UPDATED 00Z...
STILL A LITTLE CONCERN THAT THERE MAY BE SOME LAKE EFFECT CLOUD
DEVELOPMENT OVERNIGHT. RUC SOUNDINGS AND 925 MB RH FIELDS REALLY
SATURATE AROUND THE 1.5 KFT LAYER. WHILE THERE IS A LITTLE LAKE
INSTABILITY THAT COULD ALLOW A FEW CLOUDS TO POP...WOULDNT EXPECT
IT TO BE ANY THICKER THAN FEW...BUT ALSO BELIEVE THAT THE RUC IS
REALLY OVERDOING THIS FEATURE AND THAT THE ATMOSPHERE WILL BE FAR
TO DRY TO SUPPORT ANY CLOUDS AND NAM/HRRR TRENDS CONTINUE TO
SUPPORT THIS. WILL LEAVE KEEP ANY MENTION OF ANY CLOUD COVER OUT
OF THE 00Z PACKAGE AT THIS POINT.
OTHERWISE GUSTY CONDITIONS WILL SLOWLY ABATE OVERNIGHT AND FALL TO
AROUND 5-7 KTS. WINDS WILL THEN TURN EASTERLY AND EVENTUALLY
SOUTHEASTERLY AS HIGH PRESSURE SHIFTS OFF TO THE EAST.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE WITH EVENING WIND SPEED/DIRECTION/GUSTS
* LOW CONFIDENCE WITH ANY OVERNIGHT CIGS BEING THICKER THAN FEW
SHEA
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY...CHANCE OF SHRA/TSRA LATE...OTHERWISE VFR
* SUNDAY...VFR
* MONDAY...CHANCE OF SHRA...OTHERWISE VFR
* TUESDAY...MVFR POSSIBLE
* WEDNESDAY...VFR
SHEA
&&
.MARINE...
207 PM CDT
HIGH PRESSURE CENTERED OVER ONTARIO AND THE NORTHERN LAKES WILL
SLIDE SLOWLY SOUTHEAST THROUGH FRIDAY...ALLOWING NORTHEAST WINDS
CURRENTLY GUSTING TO 20-25 KTS TO SLOWLY DECREASE ACROSS LAKE
MICHIGAN AS THE SOUTHERN PERIPHERY OF THE SURFACE RIDGE BUILDS
ACROSS THE LAKE. THE RIDGE WILL MOVE EAST OF THE LAKE BY EARLY
SATURDAY...ALLOWING WINDS TO BECOME SOUTH-SOUTHEAST AND INCREASE
INTO THE 15-20 KT RANGE ESPECIALLY ON THE WEST SIDE OF THE LAKE BY
SATURDAY AFTERNOON AS LOW PRESSURE LIFTS FROM THE NORTHERN HIGH
PLAINS INTO SOUTHERN MANITOBA. A COLD FRONT ARCING SOUTH FROM THIS
LOW WILL PUSH EAST ACROSS THE LAKE SATURDAY NIGHT.
THE CANADIAN LOW WILL REDEVELOP/COMBINE WITH ANOTHER AREA OF LOW
PRESSURE OVER NEW ENGLAND AND THE ST LAWRENCE VALLEY SUNDAY AND
SUNDAY NIGHT...WHILE STRONG HIGH PRESSURE DEVELOPS OVER CENTRAL
CANADA. THIS WILL RESULT IN A PUSH OF COLDER AIR AND A PERIOD OF
BLUSTERY NORTH-NORTHWEST WINDS OF 25-30 KTS ACROSS THE LAKE EARLY
NEXT WEEK.
FOR THE ILLINOIS/NORTHWEST INDIANA NEARSHORE WATERS...WILL BE
EXTENDING SMALL CRAFT ADVISORIES INTO FRIDAY MORNING...AS PROLONGED
PERIOD OF SLOWLY DIMINISHING NORTH-NORTHEAST FLOW WILL MAINTAIN
WAVES 4 FT OR GREATER THROUGH THAT TIME.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FREEZE WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...1 AM FRIDAY TO 8 AM FRIDAY.
IN...FREEZE WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...1 AM
FRIDAY TO 8 AM FRIDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM FRIDAY.
&&
$$
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 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
NWS DODGE CITY KS
601 PM CDT THU APR 5 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 422 PM CDT THU APR 5 2012
A SLOW MOVING FAIRLY BAROTROPIC CLOSED LOW WAS DRIFTING ACROSS THE
SOUTHEAST PLAINS REGION THIS MORNING, HEADING TOWARD THE LOWER
MISSISSIPPI VALLEY. WEAK NORTHEAST SURFACE FLOW DOMINATED MUCH OF
WESTERN KANSAS WITH LOW STRATUS REMAINING IN PLACE THROUGH THE DAY.
THE LOW STRATUS IMPEDED DIURNAL WARMING SO MUCH THAT TEMPERATURES
HAD ONLY REACHED THE UPPER 40S TO MID 50S BY EARLY AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 422 PM CDT THU APR 5 2012
AS DIURNAL HEATING CONTINUES THROUGH THE AFTERNOON, THE LOW LEVEL
THINNING STRATUS DECK WILL LIKELY SEE SOME BREAKS, AND THUS SOME AREAS
OF SUN MIGHT DEVELOP BY LATE IN THE DAY. THIS IS MOST LIKELY TO OCCUR
ACROSS THE EXTREME FAR SOUTHWEST SECTIONS OF WESTERN KANSAS, FROM
AROUND SYRACUSE TO HUGOTON. HOWEVER, PEAK HEATING WILL HAVE ALREADY
OCCURRED, SO IT APPEARS THE CURRENT RUC MAX TEMPERATURE FORECAST HAS
A GOOD HANDLE ON THE TREND. AS DIURNAL COOLING DEVELOPS AGAIN THIS
EVENING, IT WOULD FOLLOW THAT THE STRATUS LAYER WILL LIKELY BEGIN TO
EXPAND ONCE AGAIN GOING INTO TONIGHT. FOR TONIGHT, WITH ABUNDANT
CLOUD COVER AND LITTLE NOTICEABLE TEMPERATURE TENDENCY, THE
OVERNIGHT LOWS CAN BE AGAIN EXPECTED TO BE FAIRLY MILD, OR ABOUT
5-10 DEGREES ABOVE NORMAL FOR EARLY APRIL. THE FORECAST PROBLEM OF
THE OVERNIGHT WILL THEN BECOME, FOG AND EVEN PERHAPS THE
REDEVELOPMENT OF DRIZZLE ACROSS WESTERN KANSAS, AS THE LEAD
APPROACHING UPPER JET NOW ACROSS THE GREAT BASIN APPROACHES OUT
REGION. AS A RESULT OF THE INCREASING UPPER LEVEL CROSS BARRIER
FLOW, SURFACE PRESSURE FALLS WILL OCCUR ALONG THE LEE OF THE
MOUNTAINS BY LATE TONIGHT, INCREASING THE LOW LEVEL PRESSURE
GRADIENT ACROSS WESTERN KANSAS. THE GRADIENT WILL SUPPORT STRONG
BREEZY TO WINDY CONDITIONS ON FRIDAY. THE LINGERING CLOUD COVER AND
ADDITIONAL CIRRIFORM CLOUDS MAY ACT TO FURTHER INHIBIT MIXING. MODEL
10M WINDS ARE GENERALLY FORECASTING NEAR 20 KNOTS OF SURFACE
SUSTAINED WINDS IN ACROSS THE LARGER PART OF WESTERN KANSAS, AND THE
GFSMOS IS EVEN STRONGER. OVERNIGHT AND EARLY MORNING DRIZZLE IS MOST
LIKELY TO BE SEEN ACROSS NORTHWEST KANSAS, HOWEVER MODEL
THERMODYNAMIC PROFILES SUPPORT IT EVEN OVER A LARGE PART OF
SOUTHWEST KANSAS. CONVECTIVE CHANCES BECOME INCREASED ALONG A
DRYLINE OVER THE WESTERN COUNTIES (CLOSELY TIED TO THE COLORADO
LINE) IN THE EARLY AFTERNOON AS DIURNAL HEATING AS WELL AS STRONG
POSITIVE TEMPERATURE TENDENCY ACT TO INCREASE CONVECTIVE AVAILABLE
POTENTIAL ENERGY OVER WESTERN KANSAS. ALTHOUGH WIDESPREAD SEVERE
WEATHER IS NOT EXPECTED, AN ISOLATED SEVERE HAIL STORM OR TWO CANNOT
BE RULED OUT IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 PM CDT THU APR 5 2012
AS THE LARGE UPPER LEVEL LOW OVER ARKANSAS EXITS OUR AREA TO
EAST-SOUTHEAST TONIGHT AND FRIDAY, A HIGH AMPLITUDE RIDGE WILL BUILD
IN OVER THE PLAINS FRIDAY NIGHT AND SATURDAY. THIS SAID, THERE IS
CONSIDERABLE UPPER LEVEL INSTABILITY OVER SOUTHWEST KANSAS AS A MID
LEVEL WAVE SWINGS THROUGH FROM THE SOUTHWEST. THEREFORE, WILL HAVE
16-20 PERCENT POPS IN OUR EASTERN CWA FOR SLIGHT CHANCES OF
THUNDERSTORMS FRIDAY EVENING AND FRIDAY NIGHT. SLIGHT CHANCES WILL
LINGER IN OUR SOUTHEASTERN CWA, DUE MAINLY TO A FRONTAL BOUNDARY
WHICH WILL MIGRATE EASTWARD SATURDAY MORNING. AN UPPER HIGH
PRESSURE RIDGE BUILDS INTO THE WESTERN ROCKIES SUNDAY INTO
THURSDAY. A SURFACE FRONT SHOULD SLIDE NORTHWARD FROM OKLAHOMA AS A
WARM FRONT TUESDAY INTO WEDNESDAY, AND BRING ANOTHER ROUND OF
THUNDERSTORMS TO FIRST OUR SOUTHERN COUNTIES TUESDAY NIGHT, AND BY
WEDNESDAY FARTHER NORTH TO OUR CENTRAL COUNTIES. THE GFS MODEL IS A
LITTLE FASTER AND FARTHER NORTH WITH THIS WARM FRONT ON TUESDAY AND
WEDNESDAY, BUT FOR NOW I LIKE THE SLOWER, MORE SOUTHERN TRACK OF THE
ECMWF MODEL. BY THURSDAY, THE FRONT SHOULD BE BISECTING OUR CWA AND
AFTERNOON THUNDERSTORMS HAVE LITTLE BETTER CHANCE OF FORMING IN THE
WARM SURFACE AIR AND WITH THE FRONT SERVING AS FOCUS BOUNDARY.
LOADED THE CREXTENDFCST_INIT PROCEDURE`S QPF, AND THE AMOUNTS SEEMED
QUITE HIGH FOR THE EXTENDED PERIOD. DECREASED THE TUESDAY NIGHT
INTO THURSDAY QPF QUITE A BIT.
TEMPERATURES ARE ANOTHER IMPORTANT PART OF THIS PACKAGE. SUNDAY
MORNING LOOKS COLD ENOUGH SOME PATCHY FROST. WINDS WILL BE LIGHT,
SKIES WILL BE CLEAR, AND THE LOW LEVEL FLOW DOWN THE GEOGRAPHIC
DOWNSLOPE PATTERN SHOULD BRING MID 30S FOR MIN T`S IN OUR NORTHWEST
AND WEST. IF THE MODELS GET ANY COLDER DURING THE NEXT COUPLE OF
MODEL RUNS, COULD SEE A FROST ADVISORY NEEDED SOMEWHERE IN OUR
NORTHWESTERN CWA FOR SUNDAY MORNING. IN THE NEARER TERM, FRIDAY
NIGHT`S LOWS WILL BE IN THE MID 40S WEST TO THE MID 50S SOUTHEAST,
IN THE MID TO UPPER 40S MONDAY MORNING, DIP TO THE UPPER 30S TO MID
40S TUESDAY MORNING, THEN REBOUND TO THE 45 TO 50F DEGREE RANGE BY
BOTH WEDNESDAY AND THURSDAY. MAXIMUM TEMPERATURES WILL START OUT IN
THE MID TO UPPER 60S SATURDAY, SUNDAY AND MONDAY, BUT LOWER TO THE
MID 60S MONDAY, BEFORE WARMING UP IN OUR SOUTHWEST WED AND THUR INTO
THE LOWER 70S AS WARM FRONT BULGES NORTHWARD, WITH LOWER 60S HIGH IN
THE EASTERN CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 600 PM CDT THU APR 5 2012
MVFR CIGS WILL CONTINUE IN THE VICINITY OF ALL TAF SITES THIS
EVENING AS LOW LEVEL STRATUS PERSISTS ACROSS CENTRAL AND PORTIONS
OF WESTERN KANSAS OVERNIGHT. CIGS ARE EXPECTED TO LOWER TO IFR
LEVELS GENERALLY AFTER 06Z AS RELATIVE HUMIDITY LEVELS INCREASE
WITHIN A LIGHT LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW. ADDITIONALLY,
AREAS OF FOG ARE POSSIBLE LATE TONIGHT WITH MVFR VSBYS EXPECTED IN
THE VICINITY OF ALL TAF SITES. IFR VSBYS MAY DEVELOP ACROSS
EXTREME WESTERN KANSAS AND EXTEND AS FAR EAST AS KGCK AND
POTENTIALLY KDDC. AS FOR WINDS, SURFACE HIGH PRESSURE DRIFTING
EAST ACROSS THE UPPER MIDWEST WILL CONTINUE TO INFLUENCE LIGHT
SOUTHEASTERLY WINDS OF 5 TO 15KT THROUGH FRIDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 67 50 65 / 10 10 10 10
GCK 48 71 47 63 / 10 20 10 10
EHA 49 77 44 63 / 10 20 20 10
LBL 49 73 49 65 / 10 20 10 10
HYS 46 63 51 64 / 10 10 20 20
P28 48 65 55 67 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...JJOHNSON
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...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...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 PITTSBURGH PA
908 PM EDT THU APR 5 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE MOSTLY CLEAR SKIES AND SEASONABLY COOL
CONDITIONS INTO THE WEEKEND. SOME FROST CAN BE EXPECTED EARLY FRIDAY
MORNING AND AGAIN EARLY SATURDAY MORNING.
&&
.NEAR TERM /THROUGH FRIDAY/...
BASED ON RECENT SURFACE DATA AND HRRR AND NAM MODEL OUTPUT, HAVE
MADE FORECAST ADJUSTMENTS, MAINLY TO INCREASE THE WIND SPEED.
THE INCREASED VERTICAL MIXING DUE TO THE INCREASED WIND SPEED MAY
KEEP TEMPERATURES FROM MUCH BELOW FREEZING OVERNIGHT. HOWEVER,
WILL MAINTAIN FREEZE WARNING AS ITS TOO CLOSE TO CALL. HAVE
REDUCED COVERAGE OF FROST TO PATCHY DUE TO THE WIND AND INCREASED
INFLUX OF DRY AIR.
REGARDING WINDS FRIDAY, HAVE LIKEWISE INCREASED WIND SPEEDS AND
ADDED GUSTS UP TO 25 MPH DUE TO RECENT NAM MODEL PROFILES.
FORECASTED HIGHS FRIDAY USING A BLEND OF NAM AND SREF MODEL
OUTPUT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
FREEZE WATCH REMAINS IN EFFECT EARLY SATURDAY MORNING. AS THE SURFACE
HIGH MOVES OVERHEAD...WINDS SHOULD DECREASE FRIDAY NIGHT. THIS
SHOULD ALLOW TEMPERATURES TO DROP A COUPLE DEGREES FURTHER THAN
TONIGHTS MINIMUMS. DRYNESS OF LOWLEVEL AIR COULD AGAIN LIMIT FROST
COVERAGE. FORECAST LOWS RANGE FROM 25 TO 30 MOST
LOCATIONS...THEN TEMPERATURES SHOULD REBOUND INTO THE MID 50S TO
LOWER 60S SATURDAY AFTERNOON.
A SYSTEM TRACKING NORTH OF THE GREAT LAKES WILL BRING A WEAKENING
COLD FRONT ACROSS THE UPPER OHIO VALLEY ON SUNDAY. MODELS CONTINUE
TO SHOW SCANT MOISTURE ASSOCIATED WITH THIS FEATURE. THE FORECAST
INCLUDES A SLIGHT CHANCE OF SHOWERS ACROSS NORTHERN AREAS AND
ALONG THE RIDGES LATE IN THE DAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THERE IS ECMWF/GFSE/CANADIAN AGREEMENT THAT A FAIRLY AMPLIFIED
PATTERN WILL HOLD THROUGH THE EXTENDED WITH MID-LEVEL RIDGING ACROSS
THE ROCKIES AND A TROUGH DIGGING INTO THE EAST COAST. MODELS ARE
HINTING AT A CLOSED LOW DROPPING INTO THE UPPER OHIO VALLEY MONDAY
INTO WEDNESDAY. WITH THIS IN MIND, HAVE CHANCE POPS FORECAST THROUGH
THIS PERIOD. FORECAST IS DRY FOR THURSDAY AS DEEPER MOISTURE WITH
THE TROUGH PULLS EASTWARD.
WITH THE TROUGH USHERING CANADIAN AIR INTO THE AREA AND BRINGING
INCREASED CLOUD COVERAGE, TEMPERATURES ARE FORECAST TO BE 5 TO 10
DEGREES BELOW NORMAL THROUGHOUT THE PERIOD. DEPENDING ON THE
DEVELOPMENT AND STRENGTH OF THE CLOSED LOW, THERE IS THE CHANCE OF
SOME SNOW MIXING IN WITH RAIN SHOWERS TUESDAY NIGHT AND WEDNESDAY
NIGHT.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MOVE FROM THE GREAT LAKES INTO THE OHIO VALLEY,
ALLOWING FOR VFR CONDITIONS TO PREVAIL THROUGHOUT THE TAF PERIOD.
NORTHERLY WINDS AT 5-10 KTS OVERNIGHT WILL INCREASE TO 10-15KTS
ON FRIDAY AFTERNOON WITH GUSTS TO 22KTS AT SOME LOCATIONS.
OUTLOOK...FRIDAY THROUGH TUESDAY...
VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH SUNDAY AS HIGH
PRESSURE DOMINATES THE REGION. A COLD FRONT WILL MOVE INTO THE AREA
LATE SUNDAY INTO MONDAY AND RETURN THE CHANCE OF RESTRICTIONS WITH
SHOWERS THROUGH TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR MDZ001.
FREEZE WARNING FROM 3 AM TO 9 AM EDT FRIDAY FOR MDZ001.
OH...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR OHZ039>041-048>050-057>059-068-069.
FREEZE WARNING FROM 3 AM TO 9 AM EDT FRIDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ007>009-013>016-020>023-029-031-073>076.
FREEZE WARNING FROM 3 AM TO 9 AM EDT FRIDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR WVZ001>004-012-021>023-041.
FREEZE WARNING FROM 3 AM TO 9 AM EDT FRIDAY FOR WVZ001>004-012-
021>023-041.
&&
$$
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 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 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 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
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 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 WILMINGTON NC
730 PM EDT THU APR 5 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE SLOWLY SOUTH ACROSS THE AREA TODAY. A WAVE OF
LOW PRESSURE WILL DEVELOP ALONG THE FRONT TO OUR SOUTHWEST AND THEN
MOVE OFFSHORE FRIDAY MORNING. SHOWERS AND THUNDERSTORMS WILL BE MOST
NUMEROUS ACROSS SOUTH CAROLINA THIS AFTERNOON...WHERE SOME COULD BE
STRONG TO SEVERE. RAIN IS EXPECTED TO DEVELOP ACROSS THE AREA
TONIGHT INTO FRIDAY. COOLER CONDITIONS WILL FOLLOW FOR THE WEEKEND
AS CANADIAN HIGH PRESSURE BUILDS ACROSS THE CAROLINAS. SEVERAL DRY
COLD FRONTS WILL MOVE ACROSS THE AREA NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM THURSDAY...THE COLD FRONT IS CURRENTLY LOCATED FROM
THE WESTERN END OF OAK ISLAND ACROSS NORTHERN HORRY COUNTY TO NEAR
MARION AND FLORENCE. EXCELLENT LOW LEVEL CONVERGENCE IS DEVELOPING
ALONG THE BOUNDARY WHERE SURFACE CAPE IS NOW 2500 J/KG AND EVEN THE
100-MB MIXED LAYER CAPE IS APPROACHING 2000 J/KG. ONCE THE
CONVECTIVE CAP GOES IN THE NEXT COUPLE OF HOURS WE EXPECT TO SEE
RAPID DEVELOPMENT OF THUNDERSTORMS ACROSS THIS AREA. THE MOST-RECENT
SPC OUTLOOK MAINTAINS PROBABILITIES FOR DAMAGING WINDS AND LARGE
HAIL AWAY FROM THE NC BORDER REGION OF SOUTH CAROLINA...IN-LINE WITH
OUT THINKING AS WELL. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS...
A SOUTHWARD MOVING COLD FRONT IS MOVING THROUGH THE WILMINGTON AREA
AT THE CURRENT TIME...ACCOMPANIED BY A BANK OF LOW CLOUDS AND ABOUT
A 120-DEGREE CLOCKWISE WIND SHIFT FROM THE WEST TO NORTH-NORTHEAST.
HIGH TEMPERATURES HAVE ALREADY BEEN ESTABLISHED FOR THE DAY NORTH OF
THIS FRONT WHERE WE EXPECT TEMPERATURES TO STEADILY FALL THROUGH THE
60S THROUGH THE AFTERNOON HOURS. LINEAR EXTRAPOLATION OF THE FRONT
ON SATELLITE IMAGERY AGREES FAIRLY WELL WITH THE LATEST SEVERAL
(09Z,10Z,11Z) RUNS OF THE HRRR MODEL AND PLACE THE FRONT NEAR
SOUTHPORT...WHITEVILLE...DILLON AND BENNETTSVILLE JUST BEFORE
NOON...AND INTO THE MYRTLE BEACH AREA BY 2 PM.
PLENTY OF SUNSHINE IS WARMING AND DESTABILIZING THE AIRMASS OUT
AHEAD OF THE FRONT WHERE SKIES ARE CLEAR...AND WE ANTICIPATE
SURFACE-BASED CAPE TO GROW TO AS MUCH AS 2000 J/KG BY MID AFTERNOON.
GIVEN THE STRONG LOW-LEVEL CONVERGENCE ALONG THE FRONT AND ONLY THE
BAREST HINT OF A CAPPING INVERSION AROUND 5000 FT STRONG TO LOCALLY
SEVERE THUNDERSTORMS SHOULD DEVELOP ALONG AND SOUTH OF THE FRONTAL
POSITION AT THAT TIME...ROUGHLY DARLINGTON TO FLORENCE...MARION AND
CONWAY TO MYRTLE BEACH. THE STRONGEST 0-6 KM BULK SHEAR VALUES WILL
REMAIN WELL NORTH OF THE SURFACE FRONT ACROSS NORTHERN AND CENTRAL
NORTH CAROLINA...BUT SUFFICIENT SHEAR SHOULD STILL EXIST FOR MODEST
STORM ORGANIZATION WITH ISOLATED DAMAGING WINDS OR LARGE HAIL THE
PRIMARY THREATS EXPECTED.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MID LEVEL LOW WILL BE MOVING ACROSS
SOUTHERN SOUTH CAROLINA AT THE BEGINNING OF THE PERIOD WITH THE
SURFACE LOW OFFSHORE OF THE GEORGIA/SOUTH CAROLINA BORDER.
ISENTROPIC LIFT WILL COME TO AN END IN THE MORNING HOURS LEAVING A
SMALL AREA OF MID LEVEL FRONTOGENESIS AS THE MAIN FORCING
MECHANISM. CONTINUED TO ADVERTISE CATEGORICAL POPS THROUGH 1800
UTC WITH AN AXIS OF HIGHER QPF FROM DILLON AND MARION COUNTIES
EAST TO NEW HANOVER AND PENDER COUNTIES CITING THE STRONGER
FORCING.
FOCUS THEN SHIFTS TO TEMPERATURES AS MODEST COLD AIR ADVECTION
CONTINUES THROUGH 1800 UTC SATURDAY UNDER CLEAR/SUNNY SKIES. LATEST
MET NUMBERS APPEAR TOO COLD WITH 33 AND 36 IN LUMBERTON/WILMINGTON
FOR SATURDAY MORNING. LEANED TOWARD THE WARMER MAV NUMBERS AND EVEN
THERE I ADDED A DEGREE OR TWO AS THE BOUNDARY LAYER REMAINS MIXED.
IDEAL RADIATIONAL CONDITIONS OCCUR SUNDAY MORNING ALTHOUGH WITH AIR
MASS MODIFICATION AND A FULL DAY OF APRIL SUNSHINE TO FURTHER WARM
SOIL TEMPERATURES...FROST SHOULD NOT BE AN ISSUE.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE PATTERN IN PLACE THROUGH THE
PERIOD WITH THE CENTER OF ATTENTION BEING THE EAST COAST TROUGH. MID
LEVEL LOW RETROGRADES OVER QUEBEC MONDAY AND TUESDAY WITH A
SECONDARY SHORTWAVE MOVING ACROSS THE GREAT LAKES AND DIVING SOUTH
LATE TUESDAY AND WEDNESDAY. THIS SETUP IS NOT MUCH OF A
PRECIPITATION PRODUCER FOR OUR AREA WITH THE APPALACHIANS GENERALLY
RINGING OUT WHAT LITTLE AVAILABLE MOISTURE THERE IS. TEMPERATURE
FORECAST REMAINS MOST INTERESTING WITH LATEST MEX NUMBERS SHOWING
UPPER 30S ACROSS THE AREA. LATEST ENSEMBLE NUMBERS HAVE TRENDED
WARMER HOWEVER WITH THE OPERATIONAL NUMBERS THE COOLEST.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...SHOWERS AND ISOLATED THUNDERSTORMS WERE INCREASING THIS
EVENING ACROSS THE TERMINAL AREA...AND WILL CONTINUE TO INCREASE IN
AERIAL COVERAGE AS LOW PRESSURE APPROACHING FROM THE WEST INDUCES A
SURFACE WAVE ON A FRONTAL BOUNDARY WELL SOUTH OF THE TERMINALS AND
MOVES EAST OFFSHORE FRIDAY MORNING. SHOWERS WITH EMBEDDED THUNDERSTORMS
WILL BE LIKELY THIS EVENING THROUGH 16-18Z...ALTHOUGH AFTER 06Z-08Z
EXPECT THUNDERSTORMS TO BECOME VERY ISOLATED...BUT CANNOT RULE THEM
OUT ENTIRELY DUE A COLD CORE LOW MOVING CLOSE TO THE TERMINALS.
LOW CONFIDENCE TEMPO IFR CONDITIONS THIS EVENING. CONFIDENCE
INCREASE SIGNIFICANTLY THAT IFR WILL BECOME PREDOMINATE AFTER
05-07Z AND WILL PERSIST THROUGH 13-15Z. EAST-NORTHEAST WINDS THIS
EVENING WILL BACK TO THE NORTH TO NORTHEAST BY SUNRISE AS WIND
SPEEDS INCREASE TO 10-20 KNOTS WITH HIGHER GUSTS.
EXPECT VFR TO DEVELOP AS LOW CEILINGS AND PRECIPITATION MOVES OFF TO
THE SOUTHEAST BY 16Z AT FLO/LBT AND 18-19Z AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...ISOLATED SHOWERS POSSIBLE MONDAY MORNING.
OTHERWISE EXPECT VFR THROUGH EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM THURSDAY...FRONT HAS ADVANCED SOUTH THROUGH CAPE FEAR
AND IS ABOUT 10-15 MILES SOUTH OF THE BRUNSWICK COUNTY BEACHES. THIS
IS IN GOOD AGREEMENT WITH EARLIER PROJECTIONS. BASED ON A STRONGER-
THAN-EXPECTED SURGE OF NORTHEAST WINDS WE HAVE STARTED THE SMALL
CRAFT ADVISORY NORTH OF LITTLE RIVER INLET NOW RATHER THAN WAITING
UNTIL TONIGHT AS ORIGINALLY ADVERTISED. WIND GUSTS AT WRIGHTSVILLE
BEACH HAVE ALREADY REACHED 30 KNOTS AT TIMES. WIND SPEEDS SHOULD
DECREASE BY ABOUT 5 KNOTS BY LATE AFTERNOON...BUT WILL INCREASE
AGAIN TONIGHT. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS..
A SOUTHWARD MOVING COLD FRONT WILL EVENTUALLY SWEEP ACROSS ALL OF
OUR MARINE AREA BY THIS EVENING. AT 10 AM THE FRONT WAS LOCATED NEAR
WRIGHTSVILLE BEACH AND EXTENDED OUT HUNDREDS OF MILES TO THE EAST.
SATELLITE SHOWS THE BOUNDARY SHOULD REACH THE BRUNSWICK COUNTY
BEACHES AROUND NOON...AND THE MYRTLE BEACH AROUND BETWEEN 1 AND 2
PM. A SURGE OF NORTHEAST WINDS TO AS STRONG AS 20 KNOTS IS EXPECTED
WHEN THE FRONT PASSES OVERHEAD. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP INLAND ALONG THE FRONT AND PUSH OFFSHORE THIS
AFTERNOON. THE LARGEST CONCENTRATION OF STORMS WILL PROBABLY BE IN
THE MYRTLE BEACH VICINITY...MAINLY AFTER 2 PM.
SPECTRAL WAVE DATA FROM THE FRYING PAN SHOALS BUOY SHOWS SEAS ARE
ALMOST EVENLY SPLIT BETWEEN A LONG 15-SECOND EASTERLY SWELL AND
SHORTER PERIOD WIND WAVES FROM THE WEST WINDS AHEAD OF THE FRONT.
THE SWELL WILL CONTINUE THROUGH TONIGHT...BUT AN INCREASING
NORTHEAST WIND CHOP WILL DEVELOP BEHIND THE FRONT LEADING TO OUR
CURRENT 2-3 FT SEAS TO INCREASE TO AS HIGH AS 4-5 FT BY SUNSET NORTH
OF CAPE FEAR. CONDITIONS WILL FURTHER DETERIORATE TONIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...CONTINUED TO USE THE GFS WINDS WHICH ARE
STRONGER WHEN COMPARED TO THE NAM FOR THE PERIOD. THIS WARRANTS AN
EXTENDED PERIOD OF GUSTS TO GALE FORCE BEGINNING EASTERNMOST WATERS
THEN BLOSSOMING WESTWARD AS WE GO THROUGH THE DAY FRIDAY. HAVE
ISSUED A GALE WATCH FOR ALL WATERS FROM 1200 FRIDAY TO 0000 UTC
SATURDAY. SUSTAINED WINDS A COUPLE OF KNOTS EITHER SIDE OF 30 KNOTS
ARE EXPECTED. WINDS DIMINISH EARLY SATURDAY ALTHOUGH RESIDUAL HIGH
SEAS WILL WARRANT A SMALL CRAFT ADVISORY. ALL WATERS SHOULD BE FREE
OF ANY HEADLINES LATER SATURDAY AFTERNOON.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...BENIGN WINDS SUNDAY...TEN KNOTS OR LESS WILL
INCREASE MONDAY AS A COLD FRONT MOVES ACROSS THE WATERS. NORTHWEST
WINDS OF 10-15 KNOTS WILL DEVELOP. SEAS OF 2-3 FEET INITIALLY WILL
INCREASE ONLY SLIGHTLY TO 2-4 FEET MONDAY WITH THE FOUR FOOTERS WELL
OFFSHORE WITH THE FETCH.
&&
.TIDES/COASTAL FLOODING...
THE FULL MOON IS UPON US AND WITH THE DEVELOPING AND INCREASING NE
WINDS AND HEAVY RAINFALL...THERE IS A RISK FOR SOME MINOR COASTAL
FLOODING. DOWNTOWN WILMINGTON WILL LIKELY EXPERIENCE MINOR FLOODING
ALONG THE CAPE FEAR THIS EVE AND AGAIN FRI EVE AS THE GAGE READING
EXCEEDS 5.5 FT AT HIGH TIDE. ALONG THE COAST...MINOR COASTAL
FLOODING IS POSSIBLE AT HIGH TIDE ON FRI. THE HIGHEST OF THE TWO
PREDICTED HIGH TIDES IS DURING THE EVE. HOWEVER...THE HEAVY RAIN FRI
MORNING MAY ALLOW FOR A PERIOD OF MINOR COASTAL FLOODING AT THAT
TIME AS WELL. HIGH TIDES ALONG THE COAST...7P TONIGHT AND ON FRI...
730A AND 8P. THE HIGHEST WATER LEVELS IN DOWNTOWN WILMINGTON OCCUR 2
TO 3 HOURS AFTER HIGH TIDE AT THE BEACHES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR NCZ107.
MARINE...GALE WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING FOR
AMZ254-256.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
FRIDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ250-252.
GALE WARNING FROM 8 AM TO 8 PM EDT FRIDAY FOR AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...SRP
AVIATION...MRR
TIDES/COASTAL FLOODING...RJD
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 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 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 GREENVILLE-SPARTANBURG SC
1007 PM EDT THU APR 5 2012
.SYNOPSIS...
AN UPPER LOW WILL MERGE WITH THE DEPARTING TROUGH AS IT MOVES OFF
THE EAST COAST ON FRIDAY. COOL AND DRY HIGH PRESSURE WILL THEN BUILD
OVER OUR REGION INTO SATURDAY AND WEAKEN. AN UPPER TROUGH IS
FORECAST TO SET UP OVER THE EAST NEXT WEEK WHICH COULD LEAD TO
COOLER THAN NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH FRIDAY/...
AT 1005 PM... SURFACE LOW OVER NORTH GEORGIA ACTUALLY HAS MOVED VERY
LITTLE SINCE EARLIER THIS EVENING... BUT A SLIGHT EASTWARD SHIFT HAS
BEEN NOTED. SURFACE FRONT EXTENDED FROM NORTH GEORGIA TO SOUTHERN
SOUTH CAROLINA COAST. RECENT RUC DRIFTS THE LOW SOUTHEASTWARD
OVERNIGHT AS SURFACE HIGH PRESSURE RIDGE EXTENDS EAST OF THE
APPALACHIANS SOUTHWARD INTO THE CENTRAL CAROLINAS PUSHING THE MOST
UNSTABLE AIR OUT OF THE AREA. APPROACH AND PASSAGE OF UPPER LEVEL LOW
WILL PROVIDE SUFFICIENT UPWARD MOTION AND ISENTROPIC LIFT FOR
CONTINUED SHOWERS DURING THE NIGHT. ISOLATED THUNDERSTORMS
POSSIBLE... PRIMARILY NEAR SURFACE BOUNDARY... BUT MOST OF THE
PRECIPITATION WILL BE FREE OF THUNDER. LOCALLY HEAVY RAIN WILL BE
POSSIBLE IN THE ISOLATED CONVECTIVE STORMS AND NEAR BLUE RIDGE
ESCARPMENT WHERE UPSLOPE FLOW WILL BE PRESENT. UPPER LOW FORECAST BY
RUC TO MOVE FROM NORTHERN ALABAMA TONIGHT TO JUST SOUTH OF THE CWA
BY 12Z. DEEPEST MOISTURE AND BEST OMEGA IN DEFORMATION ZONE NORTH OF
LOW WILL MOVE OVER AREA BETWEEN MIDNIGHT AND 10Z. NORTHERLY FLOW
FOLLOWING PASSAGE OF UPPER LOW WILL BE ACCOMPANIED BY SIGNIFICANT
DRYING FRIDAY MORNING.
AT 730 PM EDT... CONVECTIVE STORMS HAVE WEAKENED CONSIDERABLY AND
DIMINISHED IN COVERAGE. MODERATELY HIGH CAPE WILL REMAIN OVER
SOUTHWESTERN PORTION OF THE CWA TONIGHT... BUT SOUTHWESTWARD
PENETRATION OF SURFACE-BASED STABLE AIR WILL GREATLY LIMIT THUNDER
POTENTIAL ACROSS NORTHEASTERN ZONES. THUNDERSTORMS MOST LIKELY IN
VICINITY OF SURFACE BOUNDARY. LATEST MESO ANALYSES INDICATED SURFACE
LOW WAS OVER NORTH GEORGIA AND IT IS EXPECTED TO TRAVEL EASTWARD
DURING THE NIGHT. ASSOCIATED VERTICAL MOTION MAXIMUM WILL ALSO MOVE
EASTWARD PROMOTING QUITE A BIT OF RAIN AND ISOLATED THUNDER.
EASTERLY LOW LEVEL FLOW WILL CONTRIBUTE TO HEALTHY RAINFALL ORIENTED
EAST TO WEST... MAINLY THROUGH CENTRAL PORTION OF FORECAST AREA...
BUT EXCESSIVE RAINFALL AND PROBABILISTIC QPF GUIDANCES AT THIS TIME
DO NOT SIGNAL FLOOD-PRODUCING RAINS. LOCL RUNOFF PROBLEMS COULD
DEVELOP... BUT NOT ANTICIPATING SUFFICIENTLY WIDESPREAD HEAVY RAIN
TO JUSTIFY A FLOOD WATCH OF ANY KIND. SITUATION WILL BE MONITORED.
AT 430 PM EDT...
STRONGEST CONVECTIVE STORMS MOVING SLOWLY NORTHEAST FROM SOUTHERN NC
MOUNTAINS SOUTHEAST INTO SC PIEDMONT. STORMS WILL CONTINUE THAT
MOTION IN THE NEAR TERM... BUT MORE STABLE AIR JUST TO THE EAST WILL
LIKELY PREVENT EXPANSION OF DAMAGING WIND AND HAIL INTO OUR EASTERN
ZONES. RAIN WILL GRADUALLY SPREAD INTO THAT AREA... HOWEVER. RAIN
WILL PERSIST WESTERN PORTION OF NC PIEDMONT... FOOTHILLS... AND
ALONG BLUE RIDGE ESCARPMENT. WILL MONITOR THAT AREA FOR POSSIBILITY
OF EXCESSIVE RAINFALL LATER AS PERSISTENT EAST/WEST AREA OF
PRECIPITATION DEVELOPS JUST NORTH OF SURFACE LOW. DRIER AIR MOVING
INTO SOUTHWESTERN ZONES WILL RESULT IN DIMINISHING SHOWER CHANCE FOR
A WHILE... BUT BAND OF CONVECTIVE RAINFALL ASSOCIATED WITH UPPER
LEVEL SYSTEM WILL SWING INTO AREA LATER THIS EVENING OR EARLY
TONIGHT.
PREVIOUS DISCUSSION...
ANY LINGERING PRECIP QUICKLY TAPERS OFF FRI MORNING AS THE SYSTEM
MOVES EAST OF THE AREA. CLOUDS WILL SCATTER OUT FOR MOST AREAS
DURING THE AFTERNOON....BUT COULD LINGER ACROSS THE BLUE RIDGE THRU
THE DAY IN WEAK UPSLOPE FLOW. HIGHS WILL BE QUITE A BIT COOLER AS
THICKNESSES FALL IN THE COOLER AND DRIER AIR MASS MOVING IN...ENDING
UP AS MUCH AS 5 DEGREES BELOW NORMAL.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 2 PM EDT THURSDAY...THE SHORT TERM FCST PICKS UP AT 00Z ON
SATURDAY WITH THE STEEP UPPER RIDGE AXIS OVER THE CENTRAL CONUS AND
A BROAD UPPER TROF LINGERING OVER NEW ENGLAND. AS THE UPPER RIDGE
DRIFTS TOWARDS THE CAROLINAS IT WILL DEAMPLIFY SO THAT BY THE END OF
THE PERIOD LATE SUNDAY WE ARE UNDER NEARLY ZONAL NWLY H5 FLOW.
ON SATURDAY...DRY AND COOL HIGH PRESSURE CENTERED OVER THE GREAT
LAKES WILL BRING US THE COOLEST TEMPERATURES WE HAVE HAD IN A WHILE.
LOWS EARLY SATURDAY MORNING WILL LIKELY DROP DOWN INTO THE MID TO
UPPER 30S ACROSS MUCH OF WESTERN NC WITH LOWER 30S IN SOME OF THE
NORTHERN MOUNTAINS. WINDS WILL ALSO BE LIGHT...SO THERE IS GOOD
POTENTIAL FOR PATCHY FROST. RH VALUES DROP BELOW 30% FOR ABOUT 4 TO
6 HOURS DURING THE AFTERNOON/EARLY EVENING PERIOD...HOWEVER WEAKER
WINDS SHOULD SUPPRESS FIRE DANGER POTENTIAL. ON SUNDAY...SOME SORT OF
WEAK BNDY WILL MOVE THRU THE CWFA DURING THE AFTERNOON...BUT THIS
WILL HAVE LITTLE IMPACT ON THE SENSIBLE WX. TEMPS WILL WARM BACK
INTO THE LOW TO MID 70S AS THICKNESSES INCREASE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...NO MAJOR CHANGES WERE MADE TO THE MEDIUM RANGE
FCST WITH THINGS STAYING IN LINE WITH HPC GUIDANCE. REFER TO
PREVIOUS DISCUSSION BELOW.
PREVIOUS DISCUSSION...
AS OF 130 AM THURSDAY...ON SUNDAY THE WEAK UPPER RIDGE WILL BE
BREAKING DOWN. WITH PLENTY OF SUNSHINE AND THICKNESS VALUES ON THE
WARM SIDE...EXPECT HIGHS IN THE 70S ACROSS THE FORECAST AREA.
STARTING THE WEEK...EXPECT AN UPPER TROUGH TO DEVELOP OVER THE
EAST. BOTH THE GFS AND ECMWF HAVE A CLOSED OFF LOW OVER THE GREAT
LAKES AT 12Z MONDAY AS IT SLIDES EAST OR SOUTHEAST. THE ECMWF HAS A
DEEPER TROUGH AS WE PROGRESS INTO THE MID WEEK. LOOKS LIKE THE BEST
CONSENSUS OF SHOWERS OVER THE NC MOUNTAINS WILL BE TUESDAY
AFTERNOON. A GOOD PRESSURE GRADIENT DEVELOPS MONDAY AFTERNOON AND
GRADUALLY DECREASES ON TUESDAY AND I HAVE INCREASED THE WIND IN THIS
PERIOD AS THIS GRADIENT CERTAINLY SUPPORTS IT. THE ECMWF HAS AN
UPPER CLOSED OFF LOW OVER THE CAROLINAS AND VIRGINIA WEDNESDAY NIGHT
AS THE GFS HAS THE TROUGH TRYING TO PULL OFF THE EAST COAST BY THAT
TIME. TEMPERATURES SHOULD BE NEAR NORMAL ON MONDAY...BUT AS THE
TROFINESS SETS UP FOR DAYS 6 AND 7 THE TEMPERATURES WILL LIKELY BE A
FEW DEGREES BELOW NORMAL BY THAT TIME. LOWS IN THE 30S FOR THE NC
MOUNTAINS IN MID WEEK.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AT KCLT... WIND EXPECTED TO REMAIN SLIGHT NORTH OF EAST... BUT
OCCASIONAL DIPS TO EAST SOUTHEAST ARE LIKELY TO CONTINUE. AIR MASS
HAS STABILIZED ENOUGH ACROSS TERMINAL AREA TO PRECLUDE ALL BUT
ISOLATED THUNDERSTORMS. RAIN WILL OCCUR OVERNIGHT WITH CEILING
GRADUALLY LOWERING TO AROUND 15 HND FT. VISIBILITY WILL REMAIN AT OR
ABOVE 3 MILES. AFTER 15Z... CEILING NEAR 5K FT AND VISIBILITY
UNRESTRICTED.
ELSEWHERE... CEILING LOWERING TO 3-5K FT WITH VISIBILITY NEAR 5
MILES IN RAIN AND ISOLATED THUNDERSTORMS. HIGHER TERRAIN OBSCURED
VICINITY KAVL. THUNDERSTORMS MOST LIKELY VICINITY KAND...KGMU...
KGSP... AND KAVL. SURFACE WIND NORTHEAST 10 TO 15 KT EXCEPT NORTH AT
KAVL. AFTER 14Z... CEILING NEAR 5K FT AND VISIBILITY UNRESTRICTED.
OUTLOOK...A DRY HIGH PRESSURE SYSTEM WILL BUILD IN BY FRI AFTERNOON
AND DOMINATE THE WEATHER THROUGH THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...LGL
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...LGL
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 SPOKANE WA
803 PM PDT Thu Apr 5 2012
.SYNOPSIS...
The Inland Northwest will remain under a cool and unstable air mass
which will promote scattered showers and possibly a few
thunderstorms through Friday. A break in the active weather
pattern will occur this weekend and early next week...before more
unsettled weather returns by the middle of the week.
&&
.DISCUSSION...
Update: Radar data this evening clearly indicated a low centered
southwest of Moses Lake near Mattawa. Showers for the rest of this
evening will be focused around the periphery of this low with the
Moses Lake and Wenatchee areas in closest proximity to the low.
Satellite imagery shows the low to be nearly stationary with
models showing potentially a slight drift south overnight. This
will keep the Moses Lake and Wenatchee areas in close proximity
with HRRR and MM5 WRF-GFS showing showers persisting into the
overnight hours although becoming more isolated. Thus the forecast
has been updated to increase precipitation chances especially in
Wenatchee and Blewett Pass given current radar trends. Meanwhile
models show moisture beginning to be drawn northward towards
Central Idaho overnight as a short wave moving into southern
Idaho. Models have backed off a little bit with the northern
extent of this with precip likely remaining over the Clearwaters
overnight, and then moving into the Camas Prairie area Friday
morning possibly as far north as Lookout Pass. Precipitation
chances were modified over Southeast Washington into the Idaho
Panhandle through Friday morning to account for this timing.
Elsewhere for this evening showers have dwindled with the loss of
daytime heating with dry conditions expected for the rest of
tonight. JW
&&
.AVIATION...
00z TAFS: A cold unstable upper level trough will remain over the
area through Friday. This will promote scattered rain or snow
showers and isolated thunderstorms with small hail from 00-02Z
tonight...and again from 18Z to 24Z Friday. All TAF sites will
likely experience VFR conditions during day and evening unstable
periods...with brief MVFR conditions if any shower cores move
across any particular TAF site. Light winds and clearing skies
aft 03z will bring the potential for bcfg along the KGEG- KCOE
corridor with MVFR ceiling stratus expected to develop across SE
WA and advect into KPUW. The northern periphery of the stratus
shield will extend toward KGEG but confidence is low if we will
see restrictions and opted to include sct decks at this time. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 30 46 31 51 33 60 / 10 40 20 10 0 0
Coeur d`Alene 29 42 31 51 31 60 / 10 50 30 10 0 0
Pullman 29 43 30 50 32 62 / 20 50 30 0 0 0
Lewiston 34 46 33 57 37 67 / 20 40 20 0 0 0
Colville 28 48 31 54 32 60 / 10 50 30 10 0 0
Sandpoint 28 41 30 49 29 57 / 10 50 40 10 0 0
Kellogg 27 38 28 48 29 58 / 20 80 60 10 0 0
Moses Lake 28 53 29 57 35 65 / 40 20 10 0 0 0
Wenatchee 33 52 32 54 36 61 / 60 20 10 0 0 0
Omak 30 53 30 55 33 61 / 20 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
857 PM CDT THU APR 5 2012
.UPDATE...
CURRENT FORECAST LOOKS ON TRACK. CLEAR AND COLD WITH A FREEZE
LIKELY. ACTUALLY...GIVEN TEMP TRENDS...DROPPED TEMPS ACROSS THE
BOARD BY ONE DEGREE OVERNIGHT.
&&
.AVIATION/06Z TAFS/...
VFR THROUGH THE PERIOD. LOOK FOR THE NORTHEAST WINDS IN THE
SOUTHEAST TO DIMINISH THROUGH THE NIGHT.
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT THU APR 5 2012/
SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
MIN TEMPS STILL EXPECTED TO BE IN THE UPPER 20S TO LOW 30S RANGE
OVERNIGHT. THEREFORE...FREEZE WARNING FOR ENTIRE FORECAST AREA.
LOCATIONS RIGHT ALONG THE LAKE ARE NOT EXPECTED TO DROP BELOW
FREEZING. 925MB TEMPS WILL DROP TO AROUND 1C TONIGHT. WITH A
MODERATE TO WEAK INVERSION...MIN TEMPS SHOULD BE IN THE 27 TO 30
DEGREE RANGE. NAM...ECMWF AND GEM MODELS SHOW THE COLDEST TEMPS
TONIGHT. OTHER MODELS STRUGGLE TO DROP THE TEMPS BELOW 30 DEGREES
WELL INLAND FROM THE LAKE.
THE COLDEST CORE OF THE 850MB TEMPS MOVE ACROSS SOUTHEAST WI DURING
THE NIGHT AND THEN WARM SLIGHTLY TOWARD MORNING. WEAKEST PRESSURE
GRADIENT WILL NOT MOVE OVERHEAD UNTIL AFTER 9Z. WITH LAKE TEMPS
AROUND 43F/6C AND 850MB TEMPS AROUND -2C...THE 8C LAKE-AIR
DIFFERENCE COULD BE ENOUGH TO GENERATE SOME LAKE CLOUDS IN SOUTHEAST
WI. RUC SHOWS THEM OVER THAT AREA BETWEEN 4Z AND 10Z. 1000-850MB RH
PLOTS SHOW THE AREA OF HIGHER RH SHIFTING INLAND AND DRYING OUT
TOWARD FRI MORNING. THE RUC DOES LOOK OVERDONE IN ITS INITIALIZATION
THIS AFTERNOON...SO THIS IS A LOW-CONFIDENCE SCENARIO. THE NAM AND
GFS ALSO HINT AT THE LAKE CLOUD POSSIBILITY...BUT DO NOT SEEM OVERLY
EXCITED. ANY STRATUS DEVELOPMENT WOULD INHIBIT TEMPS FROM GETTING
BELOW FREEZING.
GRADIENT OF COLDER 925 MB TEMPERATURES SETTLING INTO THE EAST WITH
WARMER READINGS THROUGH MIDDAY FRIDAY WEST YIELDS HIGHS IN THE MID
AND UPPER 50S IN THE WESTERN 2/3 OF FORECAST AREA...WITH MID TO
UPPER 40S IN THE EAST.
SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE...HIGH
A MID/UPPER LEVEL RIDGE OVER THE WESTERN GREAT LAKES SATURDAY
PUSHES EAST INTO THE EASTERN GREAT LAKES SATURDAY NIGHT AS A
SHORTWAVE EXITS THE NORTHERN PLAINS THAT REACHES NORTHWEST
WISCONSIN SATURDAY EVENING.
THE SHORTWAVE PRODUCES A STRONG LOW OVER CENTRAL CANADA AS A
TRAILING COLD FRONT ENTERS SOUTH CENTRAL WISCONSIN LATE SATURDAY
AFTERNOON AND EXITS THE SOUTHEAST SATURDAY NIGHT.
NAM FORECAST SOUNDINGS SHOW A RATHER SUBSTANTIAL CAP AROUND 7 THSD
FT WITH THE CAP WEAKENING SATURDAY EVENING AS SATURATION OCCURS
MAINLY BETWEEN 6 AND 12 THSD FT. ELEVATED CAPE IS MINIMAL SO WILL
GO WITH JUST A BAND OF SHOWERS FOLLOWED BY RATHER STRONG COLD AIR ADVECTION.
PRESSURE GRADIENT SHOULD INHIBIT FROST POTENTIAL SOMEWHAT DUE TO
WIND. WILL CONTINUE TO MENTION A POSSIBILITY. TEMPERATURES WILL
DROP INTO THE 30S BUT FREEZING TEMPERATURE POTENTIAL IS MINIMAL.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...HIGH
MAIN UPPER TROUGH BEGINS TO DIG ACROSS THE GREAT LAKES AND
NORTHEAST U.S. WEST/NORTHWEST MID/UPPER LEVEL FLOW BECOMES MORE
NORTHWEST ON MONDAY. DUE TO THE COLD AIR ALOFT AND CYCLONIC FLOW
EXPECT SOME STRATOCUMULUS...ESPECIALLY DURING THE DAYTIME AS THE MAIN
SURFACE HIGH EXTENDS ACROSS CENTRAL CANADA AND INTO THE PLAINS.
TEMPERATURES WILL COOL BACK TOWARD NORMAL BY MONDAY.
LONG TERM...
TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE...HIGH
THE 12Z GFS/00Z ECMWF KEEP THE NORTHWEST MID/UPPER FLOW AS AN
UPPER RIDGE BUILDS ACROSS THE EASTERN PLAINS INTO MINNESOTA.
THE SURFACE HIGH EXTENDS ACROSS THE UPPER MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES.
TEMPERATURES WILL BE COOL AND A FROST/FREEZE POTENTIAL WILL EXIST.
THURSDAY...FORECAST CONFIDENCE...MEDIUM
A SHORTWAVE PUSHES ACROSS THE CENTRAL ROCKIES WITH THE MID/UPPER
RIDGE NEAR THE EASTERN HIGH PLAINS AND MISSISSIPPI VALLEY.
THE SURFACE HIGH BECOMES CENTERED OVER THE GREAT LAKES AS A TROUGH
OF LOW PRESSURE ORGANIZES OVER THE CENTRAL HIGH PLAINS. THE
PRECIPITATION FROM THIS SYSTEM SHOULD REMAIN TO THE WEST.
AVIATION/00Z TAFS/...
HIGH PRESSURE SINKING SOUTHWARD ACROSS WI OVERNIGHT WILL BRING
DECREASING WINDS TOWARD FRI MORNING. CLEAR SKIES EXPECTED...BUT IT
SHOULD BE MENTIONED THAT THERE IS A THREAT FOR LAKE-INDUCED MVFR
CLOUDS TO DEVELOP ONCE AGAIN OVERNIGHT AT THE EASTERN TAF
SITES...THEN DISSIPATE FRI MORNING AS THE WEAKER WINDS AND DRIER AIR
MOVE OVERHEAD. MOST PROBABLY TIME PERIOD IF THEY WERE TO DEVELOP
WOULD BE 04Z TO 10Z.
CLEAR SKIES AND LIGHT WINDS ON FRIDAY.
MARINE...
SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH OVERNIGHT TONIGHT.
SUSTAINED NORTHEAST WINDS OF 15 TO 25 KNOTS DUE TO THE TIGHT
PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO THE NORTH AND LOW
PRESSURE TO THE SOUTH. WINDS WILL BEGIN TO EASE EARLY THIS EVENING
AS GRADIENT RELAXES WITH CORE OF HIGH SETTLING DOWN INTO EASTERN
WISCONSIN BY 12Z FRIDAY... BUT WAVES WILL REMAIN HIGH UNTIL THE
MID-OVERNIGHT HOURS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM CDT FRIDAY FOR LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 PM CDT THU APR 5 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A HUDSON BAY
HIGH ANCHORED OVER NORTHERN ONTARIO THIS AFTERNOON WHILE LOW
PRESSURE RESIDES OVER THE SOUTHERN OHIO VALLEY. LAKE EFFECT CLOUDS
DEVELOPED EARLIER TODAY AND CREATED A FEW HOUR PERIOD OF BKN
CONDITIONS OVER NORTHEAST WISCONSIN. BUT OVER-LAKE INSTABILITY HAS
WANED SINCE THEN AND CLOUDS HAVE DISSIPATED. MOSTLY SUNNY
CONDITIONS NOW EXIST OVER THE ENTIRE AREA THOUGH TEMPERATURES ARE
STRUGGLING TO GET OUT OF THE 40S. AS HIGH PRESSURE BUILDS SOUTH
TONIGHT...FREEZE HEADLINES ARE THE FORECAST CONCERN OVER THE NEXT 24
HOURS.
TONIGHT...HUDSON BAY HIGH PRESSURE OVER ONTARIO WILL SINK TO THE
SOUTH TONIGHT AND SETTLE OVER THE NORTHERN GREAT LAKES BY MORNING.
BEFORE THIS OCCURS...0-1KM AGL FLOW WILL BE 15-20KTS OVER
EAST-CENTRAL AND NORTHEAST WISCONSIN THROUGH THE EVENING SO
TEMPERATURES MAY STRUGGLE TO FALL OFF INITIALLY. BUT AS THE HIGH
PRESSURE ARRIVES AFTER MIDNIGHT...THE PRESSURE GRADIENT SLACKENS AND
BL WINDS BECOME 5KTS OR LESS BY 09Z ACROSS THE ENTIRE AREA.
MANITOWOC AND STURGEON BAY FELL TO 32 AND 30 DEGREES RESPECTIVELY
LAST NIGHT...AND WILL BE OFF TO A COLDER START THIS EVENING THAN
LAST EVENING. WITH LIGHTER WINDS TONIGHT...TEMPS DO NOT HAVE MUCH
TO FALL FOR AREAS IN THE FREEZE WATCH TO REACH FREEZE WARNING
CRITERIA (TEMP OF 28F). SO WILL UPGRADE THE FREEZE WATCH TO A
FREEZE WARNING. LOWS RANGING FROM THE UPPER TEENS TO LOWER 20S AT
THE COLD SPOTS...TO AROUND 30F NEAR THE LAKE MICHIGAN SHORELINE.
FRIDAY...HIGH PRESSURE WILL BE CENTERED OVER THE CENTRAL GREAT LAKES
FOR FRIDAY. WITH SUNNY SKIES...LOW LEVEL TEMPERATURES WILL MODERATE
BY SEVERAL DEGREES COMPARED TO TODAY. 925MB TEMPS OF 8C OVER
CENTRAL WISCONSIN AND 4C OVER EASTERN WISCONSIN CALLS FOR HIGHS IN
THE UPPER 50S WEST TO AROUND 50 DEGREES EAST.
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...MAIN FCST CONCERNS
ARE LINGERING FROST/FREEZE POTENTIAL FRIDAY NIGHT...THEN PCPN TRENDS
SATURDAY AFTERNOON AND NIGHT.
A HUDSON BAY HIGH WILL BE EDGING EASTWARD ON FRIDAY NIGHT...BUT
LINGERING DRY AIR...MOSTLY CLEAR SKIES AND DECOUPLED WINDS WILL LIKELY
LEAD TO ANOTHER NIGHT OF FROST/FREEZE CONDITIONS. THE BEST CHANCE FOR
A HARD FREEZE WILL BE ACROSS NC/FAR NE WI...WHERE MIN TEMPS SHOULD
DROP INTO THE MID TO UPPER 20S.
A COLD FRONT WILL AFFECT THE REGION LATE SATURDAY INTO SATURDAY NIGHT.
MODELS ARE FAIRLY CONSISTENT WITH PCPN TRENDS...AND SUGGEST THAT SHOWERS
WILL MAKE IT ACROSS THE WESTERN HALF OF THE FORECAST AREA LATE SATURDAY
AFTERNOON...AND ACROSS THE REST OF GRB CWA SATURDAY EVENING. HAVE RAISED
POPS TO LIKELY IN OUR FAR WESTERN COUNTIES ON SAT AFTERNOON...AND ACROSS
THE REMAINDER OF THE CWA SATURDAY EVG. STABILITY INDICES ARE UNIMPRESSIVE...
AND AFTER COORD WITH SURROUNDING OFFICES...HAVE OPTED TO REMOVE ANY
MENTION OF THUNDER WITH THIS SYSTEM.
SUNDAY SHOULD BE MAINLY DRY...ALTHOUGH AN INCREASE IN CLOUDS IS EXPECTED
IN OUR NW COUNTIES DURING THE AFTERNOON AS A WEAKENING UPPER LOW MOVES
TOWARD THE REGION. THIS SYSTEM SHOULD BRING A SMALL CHANCE OF SHOWERS
ON SUNDAY NIGHT AND MONDAY...ESPECIALLY ACROSS NC/NE WI. COOL NORTH
FLOW WILL BRING MOSTLY CLOUDY SKIES TO NORTHERN WI MONDAY NIGHT AND
TUESDAY. MAX TEMPS WILL BE BELOW NORMAL DURING THIS PERIOD.
AN UPPER LEVEL RIDGE WILL GRADUALLY BUILD INTO THE REGION FROM THE
NORTHERN PLAINS LATER IN THE WEEK...RESULTING IN PLENTY OF SUNSHINE
AND A GRADUAL MODERATION IN TEMPERATURES.
&&
.AVIATION...CLEAR SKIES...LIGHT WINDS AND GOOD VISIBILITY EXPECTED THROUGH
FRIDAY NIGHT.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
627 PM CDT THU APR 5 2012
.SHORT TERM...TODAY THROUGH SUNDAY
325 PM CDT THU APR 5 2012
FORECAST CONCERNS INCLUDE FREEZE POTENTIAL FOR LATE TONIGHT/EARLY
FRIDAY MORNING...RAIN CHANCES SATURDAY/SATURDAY EVENING.
CURRENT LOOP OF WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW HIGHLY
AMPLIFIED RIDGE OF HIGH PRESSURE EXTENDING FROM THE PLAINS INTO
WESTERN ONTARIO/HUDSON BAY CANADA. AT THE SURFACE...HIGH PRESSURE
WAS CENTERED OVER WESTERN HUDSON BAY WITH DRY/COOL NORTHEAST FLOW
SET UP INTO WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER REGIONS.
TEMPERATURES WERE IN THE 50S WITH RELATIVE HUMIDITIES READINGS IN
THE 25-30 PERCENT RANGE.
05.12Z NCEP MODEL SUITE AS WELL AS THE GEM/ECMWF ALL IN GOOD
AGREEMENT THROUGH THE SHORT TERM PERIOD.
FOR TONIGHT...WILL SEE THE HIGH OVER HUDSON BAY SINK SLOWLY SOUTH
TOWARD LAKE SUPERIOR BY MORNING WITH THE RIDGE AXIS SETTING UP
PRETTY MUCH SQUARE OVER THE AREA. THIS WILL ALLOW FOR RAPID
DECOUPLING OF THE LOWER BOUNDARY LAYER CAUSING WINDS TO BE VERY
LIGHT TO CALM. CLEAR SKIES WILL ALSO ALLOW FOR GOOD RADIATIONAL
COOLING WITH TEMPERATURES BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE
EAST OF THE MISSISSIPPI RIVER. WEST OF THE RIVER...WINDS MAY NOT
DECOUPLE ALL THE WAY AND THIS MAY BE ENOUGH TO KEEP SOME LIGHT
STIRRING GOING TO KEEP TEMPERATURES UP AROUND 32 DEGREES.
STILL...THERE WILL LIKELY BE POCKETS OF COLDER TEMPERATURES WHERE
WINDS DO DECOUPLE. WITH THIS IN MIND...AND COLLABORATION WITH OTHER
OFFICES...WILL GO WITH A FREEZE WARNING FOR THE ENTIRE AREA FROM 2 AM
TO 8 AM.
LOOK FOR THE CENTER OF THE HIGH TO SLIP EAST INTO LOWER MI ON
FRIDAY. AT THE SAME TIME...A DEEP AREA OF LOW PRESSURE MOVES OUT OF
THE INTERMOUNTAIN WEST TO ALONG THE MT/DAKOTA BORDER. THIS WILL SET
U INCREASING SOUTHEAST FLOW ACROSS THE AREA...ESPECIALLY ACROSS THE
HIGHER/MORE WIND-PRONE AREAS OF SOUTHEAST MN/NORTHEAST IA. LOOKING
FOR SOUTHEAST WINDS IN THE 5 TO 10 MPH RANGE EAST OF THE MISSISSIPPI
AND 10-20 MPH ACROSS THE AFOREMENTIONED FAVORED WIND AREAS. ALSO ON
FRIDAY...925-850MB TEMPERATURES INCREASE INTO THE 4-6C RANGE. THIS
SHOULD RESULT IN HIGHS TOPPING OFF IN THE UPPER 50S TO LOWER 60S.
WE WILL STILL SEE DRY OUTFLOW FROM THE HIGHS WITH DEW POINTS IN THE
UPPER TEENS TO MIDDLE 20S. THIS COULD RESULT IN INCREASED FIRE
WEATHER CONCERNS. MORE DETAIL CAN BE FOUND BELOW IN THE FIRE WEATHER
SECTION.
NEXT ON THE DOCKET WILL BE INCOMING COLD FRONT FOR SATURDAY. MODELS
SHOWING DIMINISHING 850-925MB MOISTURE TRANSPORT INTO THE AREA AS
THE FRONT MOVES INTO THE AREA BY AFTERNOON. AS A RESULT...NIL TO
MINIMAL MUCAPE WAS NOTED BY THE NAM/GFS. BASED ON THIS SIGNAL...HAVE
PULLED ANY THUNDER MENTION. BOTTOM LINE RESULT WITH THIS FRONTAL
PASSAGE WILL BE THE LIKELIHOOD OF A SCATTERED TO BROKEN LINE OF
SHOWERS WITH MINIMAL RAINFALL OF A FEW HUNDRETHS OF AN INCH OR SO.
WILL MAINTAIN A 40-50 POP FOR NOW BASED ON THIS REASONING. APPEARS
FRONT AND RAIN CHANCES WILL EXIT EAST OF THE AREA BY MIDNIGHT.
ON SUNDAY...MODELS SHOW THE AREA IN BREEZY WESTERLY FLOW IN THE WAKE
OF THE COLD FRONT AND LOW PASSING THROUGH SOUTHERN ONTARIO CANADA.
WINDS LIKELY TO BE IN THE 15 TO 25 MPH RANGE WITH GUSTS IN THE 30-40
MPH POSSIBLE IF FULL MIXING CAN BE REALIZED. SCATTERED TO BROKEN
FIELD OF CUMULUS/STRATOCUMULUS ALSO EXPECTED WITH COOLER CYCLONIC
FLOW ALOFT. CLOUDS LOOKS LIKE THEY WILL BE MOST PREVALENT NORTH OF
I-90 AND EAST OF THE MISSISSIPPI RIVER WHERE STEEPER LOW LEVEL LAPSE
RATES WILL RESIDE. OTHERWISE...TEMPERATURES WILL BE A BIT COOLER IN
THE LOW TO MID 50S.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
325 PM CDT THU APR 5 2012
05.12Z GFS/ECMWF IN GENERALLY GOOD AGREEMENT THROUGH THE LONG TERM.
BOTH SHOW A COOLING/DRY TREND THROUGH TUESDAY...AS COLD CANADIAN
HIGH PRESSURE OOZES INTO THE REGION. LOOKING AT HIGHS IN THE 40S TO
LOWER 50S WITH OVERNIGHT LOWS MONDAY/TUESDAY NIGHTS IN THE UPPER 20S
TO LOWER 30S FOR ANOTHER ROUND OF FREEZE POTENTIAL. WILL KEEP A
CLOSE EYE ON THIS OVER THE NEXT FEW DAYS. SOME MODEST WARMING THEN
EXPECTED WEDNESDAY AND THURSDAY AS THE SURFACE RIDGE MOVES EAST AND
HEIGHT BUILD ALOFT. LOOKING FOR HIGHS IN THE 50-55 DEGREE RANGE
WEDNESDAY AND MID 50S THURSDAY.
&&
.AVIATION...TONIGHT AND FRIDAY
627 PM CDT THU APR 5 2012
VFR CONDITIONS EXPECTED THROUGH FORECAST PERIOD AS HIGH PRESSURE
BEGINS TO MOVE OVER THE GREAT LAKES REGION. CIRRUS ACROSS WESTERN AND
CENTRAL MINNESOTA WILL GRADUALLY SLIDE OVER THE TAF SITES THROUGH
THE OVERNIGHT AND INTO FRIDAY. LIGHT EASTERLY WINDS OVERNIGHT WILL
VEER TO THE SOUTHEAST AND INCREASE TO THE 8-12 KT RANGE BY MID
MORNING. DAYTIME MIXING WILL LEAD TO AFTERNOON GUSTS AROUND 18 KTS
AT KRST.
&&
.FIRE WEATHER...THROUGH FRIDAY
325 PM CDT THU APR 5 2012
ONE MORE DAY OF LOW RELATIVE VALUES EXPECTED ON FRIDAY. LOOK FOR
MINIMUM RH VALUES IN THE 20-25 PERCENT RANGE WITH DRY SOUTHEAST
OUTFLOW FROM HIGH PRESSURE SLIDING INTO THE GREAT LAKES REGION.
SOUTHEAST WINDS EXPECTED TO BE IN THE 7-12 MPH RANGE EAST OF THE
MISSISSIPPI RIVER AND IN THE 10-20 MPH RANGE OVER THE HIGHER/MORE
WIND-PRONE AREAS OF SOUTHEAST MN/NORTHEAST IA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 PM CDT THU APR 5 2012
WI...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...ZT
FIRE WEATHER...DAS
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
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1250 AM CDT FRI APR 6 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 422 PM CDT THU APR 5 2012
A SLOW MOVING FAIRLY BAROTROPIC CLOSED LOW WAS DRIFTING ACROSS THE
SOUTHEAST PLAINS REGION THIS MORNING, HEADING TOWARD THE LOWER
MISSISSIPPI VALLEY. WEAK NORTHEAST SURFACE FLOW DOMINATED MUCH OF
WESTERN KANSAS WITH LOW STRATUS REMAINING IN PLACE THROUGH THE DAY.
THE LOW STRATUS IMPEDED DIURNAL WARMING SO MUCH THAT TEMPERATURES
HAD ONLY REACHED THE UPPER 40S TO MID 50S BY EARLY AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 422 PM CDT THU APR 5 2012
AS DIURNAL HEATING CONTINUES THROUGH THE AFTERNOON, THE LOW LEVEL
THINNING STRATUS DECK WILL LIKELY SEE SOME BREAKS, AND THUS SOME AREAS
OF SUN MIGHT DEVELOP BY LATE IN THE DAY. THIS IS MOST LIKELY TO OCCUR
ACROSS THE EXTREME FAR SOUTHWEST SECTIONS OF WESTERN KANSAS, FROM
AROUND SYRACUSE TO HUGOTON. HOWEVER, PEAK HEATING WILL HAVE ALREADY
OCCURRED, SO IT APPEARS THE CURRENT RUC MAX TEMPERATURE FORECAST HAS
A GOOD HANDLE ON THE TREND. AS DIURNAL COOLING DEVELOPS AGAIN THIS
EVENING, IT WOULD FOLLOW THAT THE STRATUS LAYER WILL LIKELY BEGIN TO
EXPAND ONCE AGAIN GOING INTO TONIGHT. FOR TONIGHT, WITH ABUNDANT
CLOUD COVER AND LITTLE NOTICEABLE TEMPERATURE TENDENCY, THE
OVERNIGHT LOWS CAN BE AGAIN EXPECTED TO BE FAIRLY MILD, OR ABOUT
5-10 DEGREES ABOVE NORMAL FOR EARLY APRIL. THE FORECAST PROBLEM OF
THE OVERNIGHT WILL THEN BECOME, FOG AND EVEN PERHAPS THE
REDEVELOPMENT OF DRIZZLE ACROSS WESTERN KANSAS, AS THE LEAD
APPROACHING UPPER JET NOW ACROSS THE GREAT BASIN APPROACHES OUT
REGION. AS A RESULT OF THE INCREASING UPPER LEVEL CROSS BARRIER
FLOW, SURFACE PRESSURE FALLS WILL OCCUR ALONG THE LEE OF THE
MOUNTAINS BY LATE TONIGHT, INCREASING THE LOW LEVEL PRESSURE
GRADIENT ACROSS WESTERN KANSAS. THE GRADIENT WILL SUPPORT STRONG
BREEZY TO WINDY CONDITIONS ON FRIDAY. THE LINGERING CLOUD COVER AND
ADDITIONAL CIRRIFORM CLOUDS MAY ACT TO FURTHER INHIBIT MIXING. MODEL
10M WINDS ARE GENERALLY FORECASTING NEAR 20 KNOTS OF SURFACE
SUSTAINED WINDS IN ACROSS THE LARGER PART OF WESTERN KANSAS, AND THE
GFSMOS IS EVEN STRONGER. OVERNIGHT AND EARLY MORNING DRIZZLE IS MOST
LIKELY TO BE SEEN ACROSS NORTHWEST KANSAS, HOWEVER MODEL
THERMODYNAMIC PROFILES SUPPORT IT EVEN OVER A LARGE PART OF
SOUTHWEST KANSAS. CONVECTIVE CHANCES BECOME INCREASED ALONG A
DRYLINE OVER THE WESTERN COUNTIES (CLOSELY TIED TO THE COLORADO
LINE) IN THE EARLY AFTERNOON AS DIURNAL HEATING AS WELL AS STRONG
POSITIVE TEMPERATURE TENDENCY ACT TO INCREASE CONVECTIVE AVAILABLE
POTENTIAL ENERGY OVER WESTERN KANSAS. ALTHOUGH WIDESPREAD SEVERE
WEATHER IS NOT EXPECTED, AN ISOLATED SEVERE HAIL STORM OR TWO CANNOT
BE RULED OUT IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 255 PM CDT THU APR 5 2012
AS THE LARGE UPPER LEVEL LOW OVER ARKANSAS EXITS OUR AREA TO
EAST-SOUTHEAST TONIGHT AND FRIDAY, A HIGH AMPLITUDE RIDGE WILL BUILD
IN OVER THE PLAINS FRIDAY NIGHT AND SATURDAY. THIS SAID, THERE IS
CONSIDERABLE UPPER LEVEL INSTABILITY OVER SOUTHWEST KANSAS AS A MID
LEVEL WAVE SWINGS THROUGH FROM THE SOUTHWEST. THEREFORE, WILL HAVE
16-20 PERCENT POPS IN OUR EASTERN CWA FOR SLIGHT CHANCES OF
THUNDERSTORMS FRIDAY EVENING AND FRIDAY NIGHT. SLIGHT CHANCES WILL
LINGER IN OUR SOUTHEASTERN CWA, DUE MAINLY TO A FRONTAL BOUNDARY
WHICH WILL MIGRATE EASTWARD SATURDAY MORNING. AN UPPER HIGH
PRESSURE RIDGE BUILDS INTO THE WESTERN ROCKIES SUNDAY INTO
THURSDAY. A SURFACE FRONT SHOULD SLIDE NORTHWARD FROM OKLAHOMA AS A
WARM FRONT TUESDAY INTO WEDNESDAY, AND BRING ANOTHER ROUND OF
THUNDERSTORMS TO FIRST OUR SOUTHERN COUNTIES TUESDAY NIGHT, AND BY
WEDNESDAY FARTHER NORTH TO OUR CENTRAL COUNTIES. THE GFS MODEL IS A
LITTLE FASTER AND FARTHER NORTH WITH THIS WARM FRONT ON TUESDAY AND
WEDNESDAY, BUT FOR NOW I LIKE THE SLOWER, MORE SOUTHERN TRACK OF THE
ECMWF MODEL. BY THURSDAY, THE FRONT SHOULD BE BISECTING OUR CWA AND
AFTERNOON THUNDERSTORMS HAVE LITTLE BETTER CHANCE OF FORMING IN THE
WARM SURFACE AIR AND WITH THE FRONT SERVING AS FOCUS BOUNDARY.
LOADED THE CREXTENDFCST_INIT PROCEDURE`S QPF, AND THE AMOUNTS SEEMED
QUITE HIGH FOR THE EXTENDED PERIOD. DECREASED THE TUESDAY NIGHT
INTO THURSDAY QPF QUITE A BIT.
TEMPERATURES ARE ANOTHER IMPORTANT PART OF THIS PACKAGE. SUNDAY
MORNING LOOKS COLD ENOUGH SOME PATCHY FROST. WINDS WILL BE LIGHT,
SKIES WILL BE CLEAR, AND THE LOW LEVEL FLOW DOWN THE GEOGRAPHIC
DOWNSLOPE PATTERN SHOULD BRING MID 30S FOR MIN T`S IN OUR NORTHWEST
AND WEST. IF THE MODELS GET ANY COLDER DURING THE NEXT COUPLE OF
MODEL RUNS, COULD SEE A FROST ADVISORY NEEDED SOMEWHERE IN OUR
NORTHWESTERN CWA FOR SUNDAY MORNING. IN THE NEARER TERM, FRIDAY
NIGHT`S LOWS WILL BE IN THE MID 40S WEST TO THE MID 50S SOUTHEAST,
IN THE MID TO UPPER 40S MONDAY MORNING, DIP TO THE UPPER 30S TO MID
40S TUESDAY MORNING, THEN REBOUND TO THE 45 TO 50F DEGREE RANGE BY
BOTH WEDNESDAY AND THURSDAY. MAXIMUM TEMPERATURES WILL START OUT IN
THE MID TO UPPER 60S SATURDAY, SUNDAY AND MONDAY, BUT LOWER TO THE
MID 60S MONDAY, BEFORE WARMING UP IN OUR SOUTHWEST WED AND THUR INTO
THE LOWER 70S AS WARM FRONT BULGES NORTHWARD, WITH LOWER 60S HIGH IN
THE EASTERN CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1240 AM CDT FRI APR 6 2012
LOW LEVEL MOIST UPSLOPE FLOW WILL RESULT IN LOWERING CIGS TO LIFR
AFTER 06Z AT GCK/DDC AND IFR AT HYS. VISBYS COULD ALSO DROP TO AS
LOW AS 1 MILE AT TIMES THROUGH 15Z AT GCK/HYS ALONG WITH SOME
PATCHY DRIZZLE. CIGS WILL GRADUALLY INCREASE TO IFR THEN MVFR BETWEEN
14Z AND 18Z WITH DAYTIME HEATING AND AS WINDS SHIFT MORE TO THE
SOUTH AND INCREASE AND UPSLOPE FLOW DIMINISHES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 65 37 67 / 10 0 0 0
GCK 45 63 36 67 / 10 0 0 0
EHA 45 63 38 69 / 20 0 0 0
LBL 48 65 38 69 / 10 0 0 0
HYS 50 64 37 67 / 20 0 0 0
P28 55 67 43 68 / 20 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT FRI APR 6 2012
.SYNOPSIS...
AN UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
TRACK OFFSHORE THE CAROLINA COAST THIS MORNING. IN THE WAKE OF THE
UPPER LEVEL LOW...DRY CONDITIONS WILL PREVAIL OVER THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 305 AM FRIDAY...
MUCH OF CENTRAL NC IS EXPERIENCING A LULL IN PRECIP AS THE INITIAL
SURGE OF PRECIP AS MOVED ON INTO THE NORTHERN COASTAL PLAIN AND
SLIGHTLY DRIER AIR ALOFT HAS PUSHED ACROSS THE AREA AHEAD OF THE
UPPER LOW....WHICH IS CURRENTLY BETWEEN KATL AND KAVL. THE SURFACE
LOW IS LESS OBVIOUS IN REGIONAL SURFACE OBS...BUT SHOULD BE
TRANSITIONING TO COASTAL SC OVER THE NEXT FEW HOURS. TO THE
NORTH...A POTENT SHORTWAVE IS DIVING SOUTH OUT OF EASTERN
CANADA...CROSSING NY/PA AT THE MOMENT...AND WILL EVENTUALLY MERGE
WITH THE AFOREMENTIONED UPPER LOW INTO A DEEPER LOW OFF THE NEW
ENGLAND COAST. CURRENT REGIONAL RADAR IMAGERY SHOWS A WELL
DEFINED... UPSLOPE ENHANCED DEFORMATION PRECIP BAND THAT HAS
DEVELOPED NORTH OF THE 850-700MB LOW....EXTENDING FROM KAVL TO NEAR
KINT OVER WESTERN NC. NEAR TERM GUIDANCE SHOWS DEFORMATION
WEAKENING TO THE EAST AS THE UPPER LOW AND NORTHERN STREAM SHORTWAVE
BEGIN TO PHASE BY 12Z. IN ADDITION...SUBSTANTIALLY DRIER AIR CAN BE
SEEN IN WATER VAPOR OVER OH/IN..PUSHING SOUTHWARD INTO KY.
THUS...WHILE WE EXPECT PRECIP WITH FILL IN ACROSS THE CWA...MOST
LIKELY ALONG THE I-40/I-85 CORRIDOR BASED ON THE HRRR AND RADAR
TRENDS...THE RAIN SHIELD SHOULD SLOWLY BEGIN TO ERODE ON THE
NORTHERN EDGE AFTER BETWEEN 09Z AND 12Z.
AS THE SURFACE LOW AND COLD FRONT PULL AWAY FROM THE AREA
TODAY...SKIES WILL ALSO CLEAR BEHIND THE PRECIP SHIELD...AND THE
ENTIRE CWA SHOULD BE CLEAR BY 21Z. WE WILL CONTINUE THE TREND OF
ENDING POPS FROM NORTHWEST TO SOUTHEAST BETWEEN 12Z AND 18Z. IF
CLOUDS AND LIGHT RAIN LINGER THROUGH MIDDAY OVER COASTAL
PLAIN...HIGHS MAY END UP BEING A DEGREE OR TWO WARMER IN THE WESTERN
PIEDMONT THAN ALONG AND EAST OF I-95...RANGING FROM 61-64 FROM EAST
TO WEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 305 AM FRIDAY...
THE MAIN FORECAST CONCERN FOR FRIDAY NIGHT THROUGH SATURDAY WILL BE
MINIMUM TEMPS AND ASSOCIATED IMPACTS AS HIGH PRESSURE BUILDS SOUTH
FROM THE GREAT LAKES AND THE AIRMASS DRIES OUT SIGNIFICANTLY. MOST
STATISTICAL GUIDANCE GIVES READINGS OF 34-39 AREAWIDE...COOLEST IN
THE NORTHERN COASTAL PLAIN. THERE IS NOT ENOUGH EVIDENCE TO SUPPORT
A WIDESPREAD FREEZE... AS A LIGHT NORTHERLY WIND SHOULD CONTINUE FOR
AT LEAST THE FIRST HALF OF THE NIGHT AND GUIDANCE SUGGESTS
LOCATIONS THAT DO HIT 32 DEGREES MAY ONLY DO SO FOR AN HOUR OR TWO.
PATCHY FROST WILL BE POSSIBLE IN FAVORED...SHELTERED AREAS...AND
WHILE DEWPOINT DEPRESSIONS ARE FORECAST TO REMAIN AROUND 5 DEGREES
OR GREATER...MODELS COULD BE UNDERREPRESENTED NEAR SURFACE MOISTURE
AS MANY AREAS OF SEEN A HALF INCH OF RAIN MORE TONIGHT. WE WILL
FORECAST LOWS OF 34 TO 38...COLDEST TO THE NORTHEAST OF THE TRIANGLE.
THE UPPER RIDGE OVER THE CENTRAL PLAIN WILL BUILD SLIGHT EASTWARD
SATURDAY...WITH WEAK WARM ADVECTION EVIDENT IN LOW LEVEL
THICKNESSES FIELDS. WE WILL FOLLOW NAM MOS FOR HIGHS SATURDAY WITH
UPPER 60S WEST TO MID 60S EAST. NORTHWESTERLY FLOW ALOFT WILL
BECOME WELL ESTABLISHED BY SATURDAY EVENING...AND MODELS SHOW A WEAK
SURFACE TROUGH IN RESPONSE TO THE EAST OF THE MOUNTAINS. THIS MAY
KEEP THE OVERNIGHT BOUNDARY LAYER LIGHTLY STIRRED DESPITE A WEAK
MSLP GRADIENT ACROSS THE REGION. PATCHY FROST WILL BE POSSIBLE
AGAIN SUNDAY MORNING AS DEWPOINTS CREEP UP INTO THE LOW TO MID 30S.
LOWS IN THE UPPER 30S AND COLDEST IN THE EASTERN CWA.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
THE LONG TERM PERIOD WILL BE LARGELY CHARACTERIZED BY COOL NW FLOW
AS A LONGWAVE TROUGH REMAINS STALLED OVER MUCH OF NE NORTH AMERICA
EXTENDING SOUTH ALONG THE EASTERN SEABOARD. A SERIES OF SHORTWAVES
WILL DELIVER A COUPLE SHOTS OF COLDER AIR ACROSS THE CAROLINAS
DURING THE PERIOD...BUT LATEST MODEL RUNS SUGGEST THE NW FLOW AND A
MORE OPEN WAVE PATTERN (THAN ONE THATS CUT OFF) SHOULD KEEP PRECIP
LIMITED DURING THIS TIME.
LOOKING DAY TO DAY...ON SUNDAY A WEAK TROUGH IS EXPECTED TO CROSS
THE AREA AS MID LEVEL SHORT WAVE OVER THE UPPER MIDWEST MOVES SE.
THIS TROUGH WILL HAVE LITTLE IMPACT ON THE WEATHER GIVEN THE DEEPER
MOISTURE BEING WELL TO OUR NORTH...SO EXPECT EXPECT FAIR AND WARM
WEATHER AFTER A CHILLY START TO THE DAY WITH TEMPS MODERATING TO THE
MID 70S FOR HIGHS.
ON MONDAY...HIGH PRESSURE WILL BRIEFLY MOVE ACROSS THE AREA...BUT
THE NEXT SHORT WAVE ROTATING AROUND THE LARGE CUTOFF OVER QUEBEC AND
ITS ASSOCIATED SFC COLD FRONT WILL APPROACH LATE IN THE DAY. MID AND
HIGH CLOUDS WILL INCREASE LATE IN THE DAY...BUT PRECIP POTENTIAL
WITH THIS SHORT WAVE LOOKS LIMITED GIVEN LACK OF DEEP MOISTURE.
HIGHS MONDAY NEAR SEASONAL NORMS.
THE AFOREMENTIONED FRONT IS EXPECTED TO MOVE THROUGH MONDAY NIGHT...
WITH DECENT CAA ON TUESDAY IN ITS WAKE. DEEP NW FLOW ON THE BACK
SIDE OF THE LONG WAVE TROUGH WILL CONTINUE OVER OUR AREA RIGHT
THROUGH THURSDAY. EXPECT A 36 HOUR PERIOD OF TEMPS ABOUT 7-10
DEGREES BELOW NORMAL FROM TUESDAY THROUGH WEDNESDAY NIGHT. RIGHT NOW
IT LOOKS LIKE THE COLDEST TEMPS MAY BE EXPERIENCED WEDNESDAY MORNING
WITH LATEST GUIDANCE SUGGESTING LOWS IN THE MID-UPR 30S. HOWEVER
WITH SOME WIND CONTINUING THROUGH THE NIGHT...FROST POTENTIAL COULD
BE LIMITED. FINALLY BY LATE THURSDAY WE`LL SEE THE PATTERN MODIFY
WITH THE TROUGH AXIS SHIFTING EAST AND SOME MODERATING AHEAD OF THE
NEXT SHORT WAVE COMING OUT OF THE CENTRAL ROCKIES.
FINALLY ITS WORTH NOTING THAT WE`VE SEEN A LOT OF SWINGS IN THE
GUIDANCE FOR THIS PERIOD OF THE FORECAST OVER THE PAST SEVERAL
RUNS...ESPECIALLY WITH THE ECMWF...SO CONFIDENCE IN THIS PART OF THE
FORECAST IS NOT ESPECIALLY HIGH. IF THE MODEL TRENDS SUCH AS THOSE
SUGGESTED IN THE 05/12Z ECMWF WERE TO REEMERGE...WE COULD SEE BETTER
CHANCES FOR PRECIP DURING THE MIDDLE OF THE WEEK AND COLDER TEMPS
LASTING LONGER THROUGH THE WEEK THAN CURRENTLY FORECAST.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 150 AM FRIDAY...
PERIODS OF RAIN WILL CONTINUE THROUGH THE EARLY MORNING HOURS AS A
LOW PRESSURE SYSTEM MOVES ACROSS GA/SC. WITH ONE LARGE AREA OF RAIN
CURRENTLY MOVING EAST OF KRDU AND KRWI...THERE WILL BE LULL PRECIP
FOR THE NEXT COUPLE OF HOURS...THOUGH RADAR TRENDS SUGGEST THE RAIN
WILL FILL BACK ION ACROSS MUCH OF CENTRAL NC BY 09Z. OVER THE
WESTERN PIEDMONT...UPSLOPE DRIVE RAINFALL IS DRIFT EAST FROM THE
FOOTHILLS TOWARD THE TRIAD...BUT THE HEAVIEST RAIN SHOULD REMAIN
WEST OF KINT/KGSO. CEILINGS SHOULD CONTINUE TO HOLD ABOVE 3K
FT...EXCEPT FOR IN THE SOUTHERN PIEDMONT AND SANDHILLS (AROUND KFAY)
AND IN AREAS WHERE HEAVIER RAIN OCCURS. A STEADY 5-10KT WIND WILL
STEADILY INCREASE AS THE SURFACE LOW STRENGTHENS OFFSHORE...AND THIS
BREEZE WILL HELP TO ALSO KEEP VSBYS ABOVE 6SM OUTSIDE OF HEAVIER
RAIN.
AS THE SURFACE LOW MOVES OFFSHORE LATER THIS MORNING...RAIN WILL
GRADUALLY COME TO AN END FROM WEST TO EAST...LINGERING LONGEST FROM
KFAY TO KRWI UNTIL 15-18Z. BRISK NORTHEASTERLY WINDS WILL INCREASE
TO NEAR 15KT AND GUST INTO THE 20-25KT RANGE UNTIL EARLY
AFTERNOON...WHEN THE PRESSURE GRADIENT WILL BEGIN TO DECREASE AND
WINDS WILL BEGIN TO DECREASE TOWARD 10KT. CLEAR SKIES AND LIGHT
NORTH-NORTHEASTERLY WINDS ARE EXPECTED FRIDAY NIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT WEEK IN ASSOC/W UPPER
LEVEL RIDGING FOLLOWED BY A PATTERN OF DRY NW FLOW ALOFT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...SMITH
SHORT TERM...SMITH
LONG TERM...NMP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1033 PM PDT Thu Apr 5 2012
.SYNOPSIS...
The Inland Northwest will remain under a cool and unstable air mass
which will promote scattered showers and possibly a few
thunderstorms through Friday. A break in the active weather
pattern will occur this weekend and early next week...before more
unsettled weather returns by the middle of the week.
&&
.DISCUSSION...
Update: Radar data this evening clearly indicated a low centered
southwest of Moses Lake near Mattawa. Showers for the rest of this
evening will be focused around the periphery of this low with the
Moses Lake and Wenatchee areas in closest proximity to the low.
Satellite imagery shows the low to be nearly stationary with
models showing potentially a slight drift south overnight. This
will keep the Moses Lake and Wenatchee areas in close proximity
with HRRR and MM5 WRF-GFS showing showers persisting into the
overnight hours although becoming more isolated. Thus the forecast
has been updated to increase precipitation chances especially in
Wenatchee and Blewett Pass given current radar trends. Meanwhile
models show moisture beginning to be drawn northward towards
Central Idaho overnight as a short wave moving into southern
Idaho. Models have backed off a little bit with the northern
extent of this with precip likely remaining over the Clearwaters
overnight, and then moving into the Camas Prairie area Friday
morning possibly as far north as Lookout Pass. Precipitation
chances were modified over Southeast Washington into the Idaho
Panhandle through Friday morning to account for this timing.
Elsewhere for this evening showers have dwindled with the loss of
daytime heating with dry conditions expected for the rest of
tonight. JW
&&
.AVIATION...
06z TAFS: A cold unstable upper level trough will remain over the
area through Friday. Scattered showers this evening over SE
Washington will moisten the boundary layer and west winds is
expected to advect stratus into KPUW btwn 11-13z. Meanwhile light
winds and moist conditions at the surface will allow patchy fog to
develop near lakes and rivers in NE Washington and the N Idaho
Panhandle between 11z-16z. Thus BCFG was maintained for KSFF and
KCOE. Other locations should continue with VFR conditions. The
atmosphere will become unstable again 18z Fri - 03z Sat with cumulus
buildups and isolated thunderstorms containing small hail. Chances
of any one storm moving over a TAF site is very low so used CB cloud
group to address thunder potential. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 30 46 31 51 33 60 / 10 40 20 10 0 0
Coeur d`Alene 29 42 31 51 31 60 / 10 50 30 10 0 0
Pullman 29 43 30 50 32 62 / 20 50 30 0 0 0
Lewiston 34 46 33 57 37 67 / 20 40 20 0 0 0
Colville 28 48 31 54 32 60 / 10 50 30 10 0 0
Sandpoint 28 41 30 49 29 57 / 10 50 40 10 0 0
Kellogg 27 38 28 48 29 58 / 20 80 60 10 0 0
Moses Lake 28 53 29 57 35 65 / 40 20 10 0 0 0
Wenatchee 33 52 32 54 36 61 / 60 20 10 0 0 0
Omak 30 53 30 55 33 61 / 20 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
102 AM CDT FRI APR 6 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A HUDSON BAY
HIGH ANCHORED OVER NORTHERN ONTARIO THIS AFTERNOON WHILE LOW
PRESSURE RESIDES OVER THE SOUTHERN OHIO VALLEY. LAKE EFFECT CLOUDS
DEVELOPED EARLIER TODAY AND CREATED A FEW HOUR PERIOD OF BKN
CONDITIONS OVER NORTHEAST WISCONSIN. BUT OVER-LAKE INSTABILITY HAS
WANED SINCE THEN AND CLOUDS HAVE DISSIPATED. MOSTLY SUNNY
CONDITIONS NOW EXIST OVER THE ENTIRE AREA THOUGH TEMPERATURES ARE
STRUGGLING TO GET OUT OF THE 40S. AS HIGH PRESSURE BUILDS SOUTH
TONIGHT...FREEZE HEADLINES ARE THE FORECAST CONCERN OVER THE NEXT 24
HOURS.
TONIGHT...HUDSON BAY HIGH PRESSURE OVER ONTARIO WILL SINK TO THE
SOUTH TONIGHT AND SETTLE OVER THE NORTHERN GREAT LAKES BY MORNING.
BEFORE THIS OCCURS...0-1KM AGL FLOW WILL BE 15-20KTS OVER
EAST-CENTRAL AND NORTHEAST WISCONSIN THROUGH THE EVENING SO
TEMPERATURES MAY STRUGGLE TO FALL OFF INITIALLY. BUT AS THE HIGH
PRESSURE ARRIVES AFTER MIDNIGHT...THE PRESSURE GRADIENT SLACKENS AND
BL WINDS BECOME 5KTS OR LESS BY 09Z ACROSS THE ENTIRE AREA.
MANITOWOC AND STURGEON BAY FELL TO 32 AND 30 DEGREES RESPECTIVELY
LAST NIGHT...AND WILL BE OFF TO A COLDER START THIS EVENING THAN
LAST EVENING. WITH LIGHTER WINDS TONIGHT...TEMPS DO NOT HAVE MUCH
TO FALL FOR AREAS IN THE FREEZE WATCH TO REACH FREEZE WARNING
CRITERIA (TEMP OF 28F). SO WILL UPGRADE THE FREEZE WATCH TO A
FREEZE WARNING. LOWS RANGING FROM THE UPPER TEENS TO LOWER 20S AT
THE COLD SPOTS...TO AROUND 30F NEAR THE LAKE MICHIGAN SHORELINE.
FRIDAY...HIGH PRESSURE WILL BE CENTERED OVER THE CENTRAL GREAT LAKES
FOR FRIDAY. WITH SUNNY SKIES...LOW LEVEL TEMPERATURES WILL MODERATE
BY SEVERAL DEGREES COMPARED TO TODAY. 925MB TEMPS OF 8C OVER
CENTRAL WISCONSIN AND 4C OVER EASTERN WISCONSIN CALLS FOR HIGHS IN
THE UPPER 50S WEST TO AROUND 50 DEGREES EAST.
.LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...MAIN FCST CONCERNS
ARE LINGERING FROST/FREEZE POTENTIAL FRIDAY NIGHT...THEN PCPN TRENDS
SATURDAY AFTERNOON AND NIGHT.
A HUDSON BAY HIGH WILL BE EDGING EASTWARD ON FRIDAY NIGHT...BUT
LINGERING DRY AIR...MOSTLY CLEAR SKIES AND DECOUPLED WINDS WILL LIKELY
LEAD TO ANOTHER NIGHT OF FROST/FREEZE CONDITIONS. THE BEST CHANCE FOR
A HARD FREEZE WILL BE ACROSS NC/FAR NE WI...WHERE MIN TEMPS SHOULD
DROP INTO THE MID TO UPPER 20S.
A COLD FRONT WILL AFFECT THE REGION LATE SATURDAY INTO SATURDAY NIGHT.
MODELS ARE FAIRLY CONSISTENT WITH PCPN TRENDS...AND SUGGEST THAT SHOWERS
WILL MAKE IT ACROSS THE WESTERN HALF OF THE FORECAST AREA LATE SATURDAY
AFTERNOON...AND ACROSS THE REST OF GRB CWA SATURDAY EVENING. HAVE RAISED
POPS TO LIKELY IN OUR FAR WESTERN COUNTIES ON SAT AFTERNOON...AND ACROSS
THE REMAINDER OF THE CWA SATURDAY EVG. STABILITY INDICES ARE UNIMPRESSIVE...
AND AFTER COORD WITH SURROUNDING OFFICES...HAVE OPTED TO REMOVE ANY
MENTION OF THUNDER WITH THIS SYSTEM.
SUNDAY SHOULD BE MAINLY DRY...ALTHOUGH AN INCREASE IN CLOUDS IS EXPECTED
IN OUR NW COUNTIES DURING THE AFTERNOON AS A WEAKENING UPPER LOW MOVES
TOWARD THE REGION. THIS SYSTEM SHOULD BRING A SMALL CHANCE OF SHOWERS
ON SUNDAY NIGHT AND MONDAY...ESPECIALLY ACROSS NC/NE WI. COOL NORTH
FLOW WILL BRING MOSTLY CLOUDY SKIES TO NORTHERN WI MONDAY NIGHT AND
TUESDAY. MAX TEMPS WILL BE BELOW NORMAL DURING THIS PERIOD.
AN UPPER LEVEL RIDGE WILL GRADUALLY BUILD INTO THE REGION FROM THE
NORTHERN PLAINS LATER IN THE WEEK...RESULTING IN PLENTY OF SUNSHINE
AND A GRADUAL MODERATION IN TEMPERATURES.
&&
.AVIATION...CLEAR SKIES...LIGHT WINDS AND GOOD VISIBILITY WILL
MAKE FOR GOOD FLYING WEATHER THROUGH FRIDAY NIGHT.
RDM
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 8 AM CDT THIS MORNING FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 PM CDT THU APR 5 2012
.SHORT TERM...TODAY THROUGH SUNDAY
325 PM CDT THU APR 5 2012
FORECAST CONCERNS INCLUDE FREEZE POTENTIAL FOR LATE TONIGHT/EARLY
FRIDAY MORNING...RAIN CHANCES SATURDAY/SATURDAY EVENING.
CURRENT LOOP OF WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW HIGHLY
AMPLIFIED RIDGE OF HIGH PRESSURE EXTENDING FROM THE PLAINS INTO
WESTERN ONTARIO/HUDSON BAY CANADA. AT THE SURFACE...HIGH PRESSURE
WAS CENTERED OVER WESTERN HUDSON BAY WITH DRY/COOL NORTHEAST FLOW
SET UP INTO WESTERN GREAT LAKES/UPPER MISSISSIPPI RIVER REGIONS.
TEMPERATURES WERE IN THE 50S WITH RELATIVE HUMIDITIES READINGS IN
THE 25-30 PERCENT RANGE.
05.12Z NCEP MODEL SUITE AS WELL AS THE GEM/ECMWF ALL IN GOOD
AGREEMENT THROUGH THE SHORT TERM PERIOD.
FOR TONIGHT...WILL SEE THE HIGH OVER HUDSON BAY SINK SLOWLY SOUTH
TOWARD LAKE SUPERIOR BY MORNING WITH THE RIDGE AXIS SETTING UP
PRETTY MUCH SQUARE OVER THE AREA. THIS WILL ALLOW FOR RAPID
DECOUPLING OF THE LOWER BOUNDARY LAYER CAUSING WINDS TO BE VERY
LIGHT TO CALM. CLEAR SKIES WILL ALSO ALLOW FOR GOOD RADIATIONAL
COOLING WITH TEMPERATURES BOTTOMING OUT IN THE 25 TO 30 DEGREE RANGE
EAST OF THE MISSISSIPPI RIVER. WEST OF THE RIVER...WINDS MAY NOT
DECOUPLE ALL THE WAY AND THIS MAY BE ENOUGH TO KEEP SOME LIGHT
STIRRING GOING TO KEEP TEMPERATURES UP AROUND 32 DEGREES.
STILL...THERE WILL LIKELY BE POCKETS OF COLDER TEMPERATURES WHERE
WINDS DO DECOUPLE. WITH THIS IN MIND...AND COLLABORATION WITH OTHER
OFFICES...WILL GO WITH A FREEZE WARNING FOR THE ENTIRE AREA FROM 2
AM TO 8 AM.
LOOK FOR THE CENTER OF THE HIGH TO SLIP EAST INTO LOWER MI ON
FRIDAY. AT THE SAME TIME...A DEEP AREA OF LOW PRESSURE MOVES OUT OF
THE INTERMOUNTAIN WEST TO ALONG THE MT/DAKOTA BORDER. THIS WILL SET
U INCREASING SOUTHEAST FLOW ACROSS THE AREA...ESPECIALLY ACROSS THE
HIGHER/MORE WIND-PRONE AREAS OF SOUTHEAST MN/NORTHEAST IA. LOOKING
FOR SOUTHEAST WINDS IN THE 5 TO 10 MPH RANGE EAST OF THE MISSISSIPPI
AND 10-20 MPH ACROSS THE AFOREMENTIONED FAVORED WIND AREAS. ALSO ON
FRIDAY...925-850MB TEMPERATURES INCREASE INTO THE 4-6C RANGE. THIS
SHOULD RESULT IN HIGHS TOPPING OFF IN THE UPPER 50S TO LOWER 60S.
WE WILL STILL SEE DRY OUTFLOW FROM THE HIGHS WITH DEW POINTS IN THE
UPPER TEENS TO MIDDLE 20S. THIS COULD RESULT IN INCREASED FIRE
WEATHER CONCERNS. MORE DETAIL CAN BE FOUND BELOW IN THE FIRE WEATHER
SECTION.
NEXT ON THE DOCKET WILL BE INCOMING COLD FRONT FOR SATURDAY. MODELS
SHOWING DIMINISHING 850-925MB MOISTURE TRANSPORT INTO THE AREA AS
THE FRONT MOVES INTO THE AREA BY AFTERNOON. AS A RESULT...NIL TO
MINIMAL MUCAPE WAS NOTED BY THE NAM/GFS. BASED ON THIS SIGNAL...HAVE
PULLED ANY THUNDER MENTION. BOTTOM LINE RESULT WITH THIS FRONTAL
PASSAGE WILL BE THE LIKELIHOOD OF A SCATTERED TO BROKEN LINE OF
SHOWERS WITH MINIMAL RAINFALL OF A FEW HUNDRETHS OF AN INCH OR SO.
WILL MAINTAIN A 40-50 POP FOR NOW BASED ON THIS REASONING. APPEARS
FRONT AND RAIN CHANCES WILL EXIT EAST OF THE AREA BY MIDNIGHT.
ON SUNDAY...MODELS SHOW THE AREA IN BREEZY WESTERLY FLOW IN THE WAKE
OF THE COLD FRONT AND LOW PASSING THROUGH SOUTHERN ONTARIO CANADA.
WINDS LIKELY TO BE IN THE 15 TO 25 MPH RANGE WITH GUSTS IN THE 30-40
MPH POSSIBLE IF FULL MIXING CAN BE REALIZED. SCATTERED TO BROKEN
FIELD OF CUMULUS/STRATOCUMULUS ALSO EXPECTED WITH COOLER CYCLONIC
FLOW ALOFT. CLOUDS LOOKS LIKE THEY WILL BE MOST PREVALENT NORTH OF
I-90 AND EAST OF THE MISSISSIPPI RIVER WHERE STEEPER LOW LEVEL LAPSE
RATES WILL RESIDE. OTHERWISE...TEMPERATURES WILL BE A BIT COOLER IN
THE LOW TO MID 50S.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
325 PM CDT THU APR 5 2012
05.12Z GFS/ECMWF IN GENERALLY GOOD AGREEMENT THROUGH THE LONG TERM.
BOTH SHOW A COOLING/DRY TREND THROUGH TUESDAY...AS COLD CANADIAN
HIGH PRESSURE OOZES INTO THE REGION. LOOKING AT HIGHS IN THE 40S TO
LOWER 50S WITH OVERNIGHT LOWS MONDAY/TUESDAY NIGHTS IN THE UPPER 20S
TO LOWER 30S FOR ANOTHER ROUND OF FREEZE POTENTIAL. WILL KEEP A
CLOSE EYE ON THIS OVER THE NEXT FEW DAYS. SOME MODEST WARMING THEN
EXPECTED WEDNESDAY AND THURSDAY AS THE SURFACE RIDGE MOVES EAST AND
HEIGHT BUILD ALOFT. LOOKING FOR HIGHS IN THE 50-55 DEGREE RANGE
WEDNESDAY AND MID 50S THURSDAY.
&&
.AVIATION...
1115 PM CDT THU APR 5 2012
HIGH PRESSURE WILL REMAIN THE MAIN WEATHER INFLUENCE INTO FRIDAY
EVENING...WITH VFR CONDITIONS PERSISTING. WINDS WILL BE MORE
SOUTHEAST FRI...WITH DEEP MIXING LEADING TO SOME AFTERNOON
GUSTINESS AT KRST. WINDS WILL THEN BECOME MORE SOUTHERLY LATE FRIDAY
NIGHT/SAT...AHEAD OF AN APPROACHING COLD FRONT. CLOUDS AND -SHRA
WILL RETURN WITH THE FRONT ALSO...WITH THE PCPN THREAT ON SAT. COULD
SEE SOME MVFR CIGS. INSTABILITY IS LIMITED...SO DON/T EXPECT A
THUNDER THREAT AT THIS TIME.
&&
.FIRE WEATHER...THROUGH FRIDAY
325 PM CDT THU APR 5 2012
ONE MORE DAY OF LOW RELATIVE VALUES EXPECTED ON FRIDAY. LOOK FOR
MINIMUM RH VALUES IN THE 20-25 PERCENT RANGE WITH DRY SOUTHEAST
OUTFLOW FROM HIGH PRESSURE SLIDING INTO THE GREAT LAKES REGION.
SOUTHEAST WINDS EXPECTED TO BE IN THE 7-12 MPH RANGE EAST OF THE
MISSISSIPPI RIVER AND IN THE 10-20 MPH RANGE OVER THE HIGHER/MORE
WIND-PRONE AREAS OF SOUTHEAST MN/NORTHEAST IA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 PM CDT THU APR 5 2012
WI...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR MNZ079-086>088-
094>096.
IA...FREEZE WARNING FROM 2 AM TO 8 AM CDT FRIDAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM.....DAS
LONG TERM......DAS
AVIATION.......RIECK
FIRE WEATHER...DAS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
952 AM EDT FRI APR 6 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE EASTERN U.S. WILL BRING MAINLY DRY WEATHER
THROUGH THE WEEKEND...ALTHOUGH A SPOT SHOWER CAN NOT BE RULED OUT
ALONG THE COAST SAT NIGHT/EARLY SUN. LOW PRESSURE BACKING ACROSS
NORTHERN NEW ENGLAND MAY BRING SCATTERED SHOWERS AT TIMES NEXT
WEEK...BUT A WASHOUT IS NOT EXPECTED.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
AREA OF CLOUDS FROM NORTHERN NEW ENGLAND HAVE MOVED SWD ACROSS N
ZONES THIS MORNING. RUC 850 MB RH IS PICKING UP ON THESE CLOUDS
AND SUGGESTS SCT-BKN SC WILL EXPAND ACROSS THE REST OF SNE THROUGH
THE AFTERNOON...SO EXPECT A MIX OF SUN AND CLOUDS. NO CHANGES TO
TEMPS/WIND. MAX TEMPS IN THE 50S EXCEPT SOME UPPER 40S IN THE
CENTRAL HILLS AND CAPE/ISLANDS. MIXING FROM 850 MB WILL BRING
WINDS OF 15-20 KNOTS TO THE SURFACE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
CLOUD COVER WILL INCREASE ESP ACROSS NH TONIGHT AS UPPER LEVEL
SHORTWAVE CONTINUES TO PUSH OFFSHORE...BRINGING IN SOME MOISTURE IN
THE MID LEVELS. STILL EXPECT A DRY FORECAST AS THERE IS A LOT OF DRY
AIR IN THE LOW LEVELS AND NOT A LOT OF LIFT. WINDS WILL STAY OUT OF
THE NNW BE LIGHT. TEMPERATURES WILL DROP TO A CHILLY 20 DEGREES
ACROSS INTERIOR NH AND MASS...WHILE THE REST OF THE REGION WILL STAY
IN THE MID TO UPPER 20S.
TOMORROW...
UPPER LEVEL LOW STILL IN PLACE ACROSS NEW ENGLAND. STILL GETTING
MARGINAL CONDITIONS FOR FIRE WEATHER CONCERNS...SEE BELOW FOR MORE
DETAILS. NORTHWEST WINDS WILL GUST UP TO 20 KTS IN THE AFTERNOON AS
MIXING OCCURS. A GOOD COOL POOL WILL BE IN PLACE ESP ACROSS THE EAST
COAST OF THE REGION. DECIDED TO INSERT POPS FOR DIURNAL SHOWERS AS
DAYTIME HEATING UNDER THE COOL POOL WILL INCREASE INSTABILITY.
EXPECT A LOW PROBABILITY BUT DEF CAN NOT RULE IT OUT. TEMPS WILL
WARM TO THE MID TO UPPER 50S...COOLER ALONG THE EAST COAST/CAPE/AND
ISLANDS. EXPECT CLOUD COVER TO INCREASE ESP ACROSS THE EASTERN HALF
OF THE CWA AS MOISTURE POOLS INTO THE REGION.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
BIG PICTURE...
CLOSED LOW PRESSURE REMAINS ENCAMPED WITHIN THE EAST COAST MEAN
UPPER TROUGH THROUGHOUT THE LONG TERM PERIOD. SEVERAL SHORTWAVES
MOVE THROUGH THE FLOW AROUND THE UPPER LOW.
SATURDAY NIGHT AND SUNDAY...
OCEANIC LOW PRESSURE MOVES ASHORE IN THE MARITIMES EAST OF HALIFAX
AND THEN MIGRATES WEST TO NORTHERN MAINE BY SUNDAY AFTERNOON.
MODELS ARE IN GENERAL AGREEMENT ALTHOUGH THE 00Z GFS IS FARTHEST
WEST WITH THE CENTER POSITION. MODEL CROSS SECTIONS SHOW
SUFFICIENTLY DEEP MOISTURE IN PLACE FOR CLOUDS ALL AREAS SATURDAY
NIGHT. MOISTURE THEN THINS IN DEPTH ON SUNDAY AND SHOULD SUPPORT AT
LEAST A MIX OF CLOUDS/SUN MOST PLACES. STILL A SUFFICIENT LAYER OF
MOISTURE OVER EASTERN MASS FOR MOSTLY CLOUDY. WITH THE PLACEMENT OF
THE SURFACE AND UPPER LOW...NOT A LOT OF LIFT OVER SOUTHERN NEW
ENGLAND SO ANY SHOWERS WILL BE QUITE LIMITED WITH BEST CHANCE IN THE
EAST CLOSEST TO THE SYSTEM.
TEMPS ARE A BLEND OF B-C MOS.
MONDAY THROUGH THURSDAY...
SURFACE AND UPPER LOW LINGER OVER QUEBEC MOST OF THIS PERIOD WITH
CYCLONIC FLOW OVER SOUTHERN NEW ENGLAND. THIS MAINTAINS A DEEP
LAYER OF MOISTURE OVER MUCH OF THE REGION...ESPECIALLY SOUTHERN NH
AND NORTHERN/WESTERN MASS. EXPECT PARTLY TO MOSTLY CLOUDY SKIES
THROUGH MUCH OF THE PERIOD. PASSAGE OF SHORTWAVES WILL SUPPORT
SHOWERS...BUT GIVEN THE PATTERN THERE IS LOW CONFIDENCE IN TIMING
SHORTWAVES. FIGURE SCATTERED TO WIDELY SCATTERED SHOWERS AS EACH
SHORTWAVE MOVES PAST. SKY COVER IS A BLEND OF ECMWF AND GMOS
DATA...TEMPS A BLEND OF GMOS AND HPC GRID DATA.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
TODAY...HIGH CONFIDENCE IN VFR CONDITIONS WITH SOME NW GUSTS UP
TO AROUND 20 KTS ESPECIALLY OVER THE WESTERN INTERIOR.
TONIGHT...MODERATE TO HIGH CONFIDENCE...MOSTLY VFR. MAY SEE SOME
INCREASING CLOUDS OVER THE N AND E WITH LOW PROBABILITY OF MVFR
POSSIBLE LATE.
KBOS TERMINAL...HIGH CONFIDENCE IN VFR CONDITIONS. NORTHWEST WINDS
WILL BE GUSTY THROUGHOUT THE DAY AGAIN ON SATURDAY. LOW PROBABILITY
OF MVFR CLOUDS STREAMING THROUGH DURING THE DAY ON SATURDAY.
SATURDAY...MODERATE CONFIDENCE VFR TO START...WITH MVFR CONDITIONS
MOVING THROUGH FROM EAST TO WEST IN SHOWERS...ESP ALONG THE EAST COAST.
OUTLOOK...SATURDAY NIGHT THROUGH THURSDAY...
SATURDAY NIGHT AND SUNDAY...
MAINLY VFR BUT WITH SMALL POTENTIAL FOR MVFR/IFR IN WIDELY SCATTERED
SHOWERS ALONG THE IMMEDIATE EAST COAST AND ISLANDS. HIGH
CONFIDENCE.
MONDAY THROUGH THURSDAY...
VFR WITH POTENTIAL FOR BRIEF MVFR CIGS/VSBYS IN SCATTERED TO WIDELY
SCATTERED SHOWERS. MODERATE CONFIDENCE.
&&
.MARINE...
TODAY AND TONIGHT...
N TO NW FLOW CONTINUES...HOWEVER EXPECT THAT WINDS WILL REMAIN
BELOW 25 KT THRESHOLD WITH A WEAKER PRES GRADIENT OVER THE
WATERS...DESPITE GUSTIER WINDS INLAND. WAVES REMAIN AROUND 2 TO 4
FT OVER THE OUTER WATERS.
SATURDAY...
HIGH PRESSURE TO THE NORTHWEST AND A DISTANT OCEAN STORM WILL
RESULT IN MARGINAL NORTHERLY SCA WIND GUSTS BETWEEN 20 AND 25
KNOTS. SEAS SHOULD REMAIN BELOW SCA THRESHOLDS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT AND SUNDAY...
LOW PRESSURE WELL TO THE EAST MOVES INTO NOVA SCOTIA SATURDAY NIGHT
AND THEN MOVES WEST TO QUEBEC AND NORTHERN MAINE SUNDAY. MOST WINDS
AND SEAS SHOULD REMAIN BELOW SMALL CRAFT VALUES. HOWEVER THERE
COULD BE A PERIOD OF GUSTS NEAR 25 KNOTS SOUTH AND EAST OF CAPE COD
AND ISLANDS LATE SUNDAY AND SUNDAY NIGHT.
MONDAY AND TUESDAY...
LOW PRESSURE REMAINS OVER QUEBEC THE FIRST HALF OF THE WEEK. THIS
BRINGS A PERSISTANT WEST SOUTHWEST WIND ACROSS THE WATERS. EXPECT
BUILDING WINDS AND SEAS MONDAY...DIMINISHING MONDAY NIGHT. ROUGH
SEAS LINGER ON THE SOUTHERN WATERS TUESDAY. SMALL CRAFT ADVISORY
WILL LIKELY BE IN EFFECT. SOME GUIDENCE POINTS TOWARD GALE FORCE
WIND GUSTS ON MONDAY. WE HAVE TRENDED THE FORECAST SPEEDS UP A
LITTLE TO FOLLOW THIS TREND BUT HAVE KEPT VALUES BELOW GALES FOR
NOW. THIS WILL NEED TO BE MONITORED OVER THE NEXT FEW FORECASTS.
&&
.FIRE WEATHER...
TODAY...
DRY WEATHER CONTINUES WITH MIN RH VALUES EXPECTED TO DIP INTO
THE UPPER TEENS TO LOW 20S. WINDS WILL BE STRONGEST OVER THE WESTERN
AND NORTHERN INTERIOR AREAS WITH GUSTS UP TO 20-25 MPH IN THESE
AREAS. LIGHTER WINDS EXPECTED OVER CT/RI AND E AND SE MA WITH
GUSTS MOSTLY AROUND 15-20 MPH. IN COORDINATION WITH STATE FIRE
OFFICIALS HAVE CANCELLED THE FIRE WEATHER WATCH AS WIND SPEEDS
WILL BE LIGHTER THAN PREV DAYS. DAY SHIFT MAY NEED TO MONITOR FOR
POSSIBLE SHORT-FUSED WARNING.
SATURDAY AND SUNDAY...
ELEVATED FIRE WEATHER CONCERNS WILL CONTINUE MAINLY INLAND FROM THE
COAST. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL CONTINUE TO DROP
BELOW 30 PERCENT WITH WIND GUSTS IN THE VICINITY OF 25 MPH.
RELATIVE HUMIDITY VALUES WILL LIKELY BE SOMEWHAT HIGHER ON THE COAST
WITH ONSHORE FLOW...SO THE BIGGEST CONCERN APPEARS TO BE INLAND FROM
THE COAST.
MONDAY THROUGH THURSDAY...
FIRE WEATHER MAY BECOME LESS OF A CONCERN WITH INCREASING LOW LEVEL
HUMIDITY AND A CHANCE OF SCATTERED SHOWERS AT TIMES. HOWEVER...A
SIGNIFICANT RAINFALL EVENT DOES NOT APPEAR TO BE IN THE CARDS AT
THIS TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/DUNTEN
NEAR TERM...KJC
SHORT TERM...DUNTEN
LONG TERM...WTB
AVIATION...WTB/DUNTEN
MARINE...WTB/DUNTEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
543 AM MDT FRI APR 6 2012
.UPDATE...
ISSUED AT 536 AM MDT FRI APR 6 2012
JUST COMPLETED AN UPDATE. PER CURRENT OBSERVATIONS...MAJORITY OF
FOG AND DRIZZLE IS CONFINED TO THE FAR WEST AND SOUTHWEST PORTION
OF THE AREA. AS YESTERDAY...THE HRRR IS CATCHING THIS VERY WELL.
SO REDUCED THE COVERAGE OF THE FOG AND DRIZZLE PER REASONING GIVEN
ABOVE. OTHERWISE...JUST ADJUSTED HOURLY GRIDS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 344 AM MDT FRI APR 6 2012
FORECAST PROBLEMS WILL BE ALL ELEMENTS THROUGH TONIGHT AND
WINDS/FIRE WEATHER CONCERNS ON SATURDAY. SATELLITE CONTINUING TO
SHOW AN AMPLIFIED/AMPLIFYING PATTERN ACROSS THE NORTHERN HEMISPHERE.
NEXT IN A SERIES OF TROUGHS IS DIGGING/SPLITTING OFF INTO THE
WESTERN PORTION OF THE COUNTRY AT THIS TIME. AIR MASS AT LOW LEVELS
IS MOIST WITH VERY DRY AT MID LEVELS.
AT JET LEVEL THE MODELS DID FINE BUT TENDED TO HAVE THE UPPER
TROUGH/JET SEGMENT TO OUR WEST A LITTLE TO FAR TO THE EAST.
THE NAM AND ECMWF WERE DOING WELL ON THE SURFACE WIND AND PRESSURE
FIELD. OVER THE AREA MODELS DID NOT HAVE THE COOLER AIR OVER THE
STATE FAR ENOUGH WEST. WITH THIS AND OVERALL THE GFS AND CANADIAN
WERE DOING A LITTLE BETTER THAN THE UKMET.
TODAY/TONIGHT...PRETTY TIGHT GRADIENT DEVELOPS DURING THE DAY WITH
MODEST PRESSURE FALLS. THIS WOULD DEFINITELY SUPPORT WINDY. AS THE
DAY SHIFT BROUGHT UP...LINGERING CLOUD COVER COULD KEEP THE FULL
POTENTIAL OF THE WIND FROM BEING REACHED. LATEST MESOSCALE MODEL
OUTPUT HAS COME IN AND NOW HOLDS ONTO THE CLOUDS EVEN LONGER AND
TEMPERATURES EVEN COOLER. SO AT THIS TIME WILL NOT ISSUE A WIND
ADVISORY AND CONTINUE THE WINDY WORDING. THE LATEST NAM...RUC AND
HRRR SHOW CLEARING OCCURRING ON THE WEST AND EAST ENDS OF THE
FORECAST AREA WITH THE CLOUDS HOLDING ON THE LONGEST IN THE CENTER.
AND FROM PREVIOUS EXPERIENCE...THAT IS A REASONABLE SOLUTION. AS A
RESULT...SIGNIFICANTLY COOLED OFF MAXES FROM EARLIER THINKING.
CURRENT DRIZZLE AND FOG THIS MORNING LOOK IN GOOD SHAPE AND WILL
CONTINUE TO MONITOR THROUGH THE END OF THE SHIFT. MODELS ARE SHOWING
SOME JET LIFT FROM LATE THIS AFTERNOON INTO THIS EVENING. MAIN
SHORTWAVE TROUGH ON THE FRONT SIDE OF THE UPPER TROUGH MOVES THROUGH
LATE IN THE DAY INTO THE NIGHT BUT THE BRUNT OF ITS LIFT IS FURTHER
NORTH AND WEST. BECAUSE OF THE COOLER MAXES NOW EXPECTED...
INSTABILITY WILL BE LESS AND CINH WILL BE MORE. GFS AND NAM
DEFINITELY SHOW THAT. ON TOP OF THIS COOLER STABLE LAYER...THE MODELS
BRING A VERY STRONG WARM/DRY LAYER ALOFT. AS A RESULT OF THIS HAVE
REMOVED ALL MENTION OF THUNDERSTORMS UNTIL 03Z WITH THE BEST CHANCE
BEGINNING AT 06Z. THIS IS WHEN THE INHIBITION IS THE WEAKEST AND
WHEN THE FRONT STARTS MOVING THROUGH. EXPECT PRECIPITATION TO BE
SPOTTY WITH LITTLE TO NO THREAT OF SEVERE WEATHER.
PRETTY TIGHT GRADIENT AND HIGH THREE HOUR PRESSURE RISES OCCUR
BEHIND THE FRONT. SO WILL PROBABLY BE WINDY...ESPECIALLY RIGHT
BEHIND THE FRONT AND THEN SLOWLY SLACKEN.
SATURDAY/SATURDAY NIGHT...PER COLLABORATION HAVE DECIDED NOT TO ISSUE
A FIRE WEATHER WATCH. FIRST WE ARE NOT THAT FAR REMOVED FROM THE
WIDESPREAD MODERATE TO HEAVY RAINS. THERE HAS NOT BE A LOT OF CHANCE
TO DRY OUT WITH LITTLE SUNSHINE...COOLER TEMPERATURES AND NOT A LOT
OF WIND. DRIER AIR DOES COME IN BEHIND THE FRONT BUT IT LOOKS LIKE
THE HIGHEST WINDS WILL BE IN THE MORNING. SO FOR THOSE REASONS
DECIDED NOT TO ISSUE A WATCH. DAY SHIFT WILL HAVE TO KEEP WATCHING
THIS. 850 MB/2 METER/NWP SUPPORT GOING TOWARD A COOLER DAY. LOOKS
LIKE A DECENT AMOUNT OF COOL AIR UPSTREAM BEHIND THIS FRONT...AND
WILL GO TOWARD THE COOLER GUIDANCE AND DID ADJUST DOWN SLIGHTLY.
FOR TONIGHT...WINDS START OUT LIGHT IN THE EVENING AND THEN QUICKLY
SHIFT TO THE SOUTH AND INCREASE SO THE LOWS WILL BE EARLY.
SUNDAY/SUNDAY NIGHT...BREEZY TO WINDY CONDITIONS ARE EXPECTED
THROUGH THE MIDDLE OF THE DAY IN ADVANCE OF A FRONT THAT WILL MOVE
IN LATE IN THE DAY. SO HIGH TEMPERATURES WILL GET A LITTLE TRICKY...
ESPECIALLY IN THE NORTHWEST PORTION. ONLY MADE SLIGHT ADJUSTMENTS TO
THE HIGH TEMPERATURE FORECAST.
THANKS TO ALL WHO COLLABORATED.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 344 AM MDT FRI APR 6 2012
AN AMPLIFIED TROUGH-RIDGE-TROUGH PATTERN WILL BE IN PLACE ACROSS THE
CONUS BY MONDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. THIS
PATTERN WILL FAVOR DRY CONDITIONS ON MONDAY...WITH SEASONABLY MILD
TEMPERATURES IN THE 60S. A SERIES OF WEAK SHORTWAVE TROUGHS WILL
PASS ACROSS THE NORTHERN MISSISSIPPI VALLEY/GREAT LAKES REGION
MONDAY NIGHT...WITH A BACK DOOR COLD FRONT DROPPING SOUTH OVER THE
CENTRAL HIGH PLAINS MONDAY NIGHT/TUESDAY. THE RESULT WILL BE
EASTERLY BL FLOW AND COOLER TEMPS ALOFT TUESDAY AND
WEDNESDAY...ALONG WITH INCREASING CLOUD COVER. THIS COULD LIMIT
DAYTIME WARMING BOTH DAYS. I COOLED HIGH TEMPS TO UPPER 50S TUE/WED
IN THE EAST AND MID-UPPER 60S IN THE WEST AND SOUTH TO STAY WITHIN
COLLABORATION...HOWEVER THIS STILL MAY BE TOO WARM.
THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS TUESDAY LIMITED TO
THE SOUTHERN PART OF THE CWA NEAR THE STALLED FRONT. BY TUESDAY
NIGHT A NEGATIVELY TILTED TROUGH WILL BEGIN TO DEVELOP TOWARD THE
GREAT BASIN. ISENTROPIC UPGLIDE AND GULF MOISTURE BUILDS NORTH
TOWARDS THE CENTRAL HIGH PLAINS...WITH SHOWER/THUNDERSTORM CHANCES
OVERSPREADING THE CWA TUESDAY NIGHT/WEDNESDAY. THE STALLED FRONT
WILL BEGIN TO LIFT NORTH WEDNESDAY AFTERNOON AS A WARM FRONT...WITH
INCREASING INSTABILITY AND SHEAR ALONG AND SOUTH OF THIS FRONT
BUILDING NORTH INTO THE CWA. THE BEST CHANCE FOR SEVERE LOOKS TO BE
OVER SW KS...THOUGH A FEW STRONG/SEVERE STORMS CANT BE RULED OUT
FURTHER NORTH OVER CWA. SHOWER/THUNDERSTORM COVERAGE WILL INCREASE
WEDNESDAY NIGHT AND THURSDAY AS THE UPPER TROUGH DEEPENS BECOMING A
CLOSED LOW CENTERED OVER NW KANSAS BY THURSDAY AFTERNOON/EVENING.
00Z GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS FEATURE
THURSDAY/THURSDAY NIGHT...WITH THE AREA IN LINE FOR DECENT RAINFALL.
SINCE THERE HAS NOT BEEN A LOT OF RUN-RUN AGREEMENT BETWEEN MODELS...
I DID NOT WANT TO INCREASE POPS OUTSIDE OF CHANCE CATEGORY. PRECIP
CHANCES DIMINISH FROM THE WEST TO EAST THURSDAY NIGHT AS SHORTWAVE
RIDGING DEVELOP OVER THE CENTRAL HIGH PLAINS IN THE WAKE OF THE
DEPARTING UPPER LOW. DRY CONDITIONS AND WARMING TEMPERATURES
CURRENTLY EXPECTED NEXT FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 536 AM MDT FRI APR 6 2012
ANOTHER COMPLICATED SET OF TAFS. ENTIRE AREA COVERED WITH STRATUS
RIGHT WITH MAJORITY OF FOG AND DRIZZLE CONFINED TO THE WEST OF KGLD.
HRRR MODEL IS CATCHING THIS SCENARIO AND USED FOR THE VISIBILITY
RESTRICTION. IFR TO JUST ABOVE IFR EXPECTED THROUGH MID MORNING
WITH SLOWLY IMPROVING CONDITIONS AFTER THAT. BY MID
AFTERNOON...VFR CONDITIONS ARE EXPECTED. WINDS WILL REMAIN GUSTY
THROUGH TONIGHT WITH SOUTHERLY WINDS THROUGH THIS EVENING BEFORE A
SHIFT TO THE NORTH AND NORTHWEST AS A COLD FRONT MOVES THROUGH.
ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG THIS FRONT.
THUNDERSTORMS SHOULD BE EAST OF KGLD WITH THUNDERSTORMS NEAR TO
KMCK. SINCE DEVELOPMENT IS SPOTTY AND MUCH LATER IN THE
PERIOD...CHOSE TO HANDLE WITH ONLY A CB MENTION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM....DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
700 AM EDT FRI APR 6 2012
.SYNOPSIS...
AN UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
TRACK OFFSHORE THE CAROLINA COAST THIS MORNING. IN THE WAKE OF THE
UPPER LEVEL LOW...DRY CONDITIONS WILL PREVAIL OVER THE WEEKEND.
&&
.NEAR TERM /TODAY/...
AS OF 305 AM FRIDAY...
MUCH OF CENTRAL NC IS EXPERIENCING A LULL IN PRECIP AS THE INITIAL
SURGE OF PRECIP AS MOVED ON INTO THE NORTHERN COASTAL PLAIN AND
SLIGHTLY DRIER AIR ALOFT HAS PUSHED ACROSS THE AREA AHEAD OF THE
UPPER LOW....WHICH IS CURRENTLY BETWEEN KATL AND KAVL. THE SURFACE
LOW IS LESS OBVIOUS IN REGIONAL SURFACE OBS...BUT SHOULD BE
TRANSITIONING TO COASTAL SC OVER THE NEXT FEW HOURS. TO THE
NORTH...A POTENT SHORTWAVE IS DIVING SOUTH OUT OF EASTERN
CANADA...CROSSING NY/PA AT THE MOMENT...AND WILL EVENTUALLY MERGE
WITH THE AFOREMENTIONED UPPER LOW INTO A DEEPER LOW OFF THE NEW
ENGLAND COAST. CURRENT REGIONAL RADAR IMAGERY SHOWS A WELL
DEFINED... UPSLOPE ENHANCED DEFORMATION PRECIP BAND THAT HAS
DEVELOPED NORTH OF THE 850-700MB LOW....EXTENDING FROM KAVL TO NEAR
KINT OVER WESTERN NC. NEAR TERM GUIDANCE SHOWS DEFORMATION
WEAKENING TO THE EAST AS THE UPPER LOW AND NORTHERN STREAM SHORTWAVE
BEGIN TO PHASE BY 12Z. IN ADDITION...SUBSTANTIALLY DRIER AIR CAN BE
SEEN IN WATER VAPOR OVER OH/IN..PUSHING SOUTHWARD INTO KY.
THUS...WHILE WE EXPECT PRECIP WITH FILL IN ACROSS THE CWA...MOST
LIKELY ALONG THE I-40/I-85 CORRIDOR BASED ON THE HRRR AND RADAR
TRENDS...THE RAIN SHIELD SHOULD SLOWLY BEGIN TO ERODE ON THE
NORTHERN EDGE AFTER BETWEEN 09Z AND 12Z.
AS THE SURFACE LOW AND COLD FRONT PULL AWAY FROM THE AREA
TODAY...SKIES WILL ALSO CLEAR BEHIND THE PRECIP SHIELD...AND THE
ENTIRE CWA SHOULD BE CLEAR BY 21Z. WE WILL CONTINUE THE TREND OF
ENDING POPS FROM NORTHWEST TO SOUTHEAST BETWEEN 12Z AND 18Z. IF
CLOUDS AND LIGHT RAIN LINGER THROUGH MIDDAY OVER COASTAL
PLAIN...HIGHS MAY END UP BEING A DEGREE OR TWO WARMER IN THE WESTERN
PIEDMONT THAN ALONG AND EAST OF I-95...RANGING FROM 61-64 FROM EAST
TO WEST.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 305 AM FRIDAY...
THE MAIN FORECAST CONCERN FOR FRIDAY NIGHT THROUGH SATURDAY WILL BE
MINIMUM TEMPS AND ASSOCIATED IMPACTS AS HIGH PRESSURE BUILDS SOUTH
FROM THE GREAT LAKES AND THE AIRMASS DRIES OUT SIGNIFICANTLY. MOST
STATISTICAL GUIDANCE GIVES READINGS OF 34-39 AREAWIDE...COOLEST IN
THE NORTHERN COASTAL PLAIN. THERE IS NOT ENOUGH EVIDENCE TO SUPPORT
A WIDESPREAD FREEZE... AS A LIGHT NORTHERLY WIND SHOULD CONTINUE FOR
AT LEAST THE FIRST HALF OF THE NIGHT AND GUIDANCE SUGGESTS
LOCATIONS THAT DO HIT 32 DEGREES MAY ONLY DO SO FOR AN HOUR OR TWO.
PATCHY FROST WILL BE POSSIBLE IN FAVORED...SHELTERED AREAS...AND
WHILE DEWPOINT DEPRESSIONS ARE FORECAST TO REMAIN AROUND 5 DEGREES
OR GREATER...MODELS COULD BE UNDERREPRESENTED NEAR SURFACE MOISTURE
AS MANY AREAS OF SEEN A HALF INCH OF RAIN MORE TONIGHT. WE WILL
FORECAST LOWS OF 34 TO 38...COLDEST TO THE NORTHEAST OF THE TRIANGLE.
THE UPPER RIDGE OVER THE CENTRAL PLAIN WILL BUILD SLIGHT EASTWARD
SATURDAY...WITH WEAK WARM ADVECTION EVIDENT IN LOW LEVEL
THICKNESSES FIELDS. WE WILL FOLLOW NAM MOS FOR HIGHS SATURDAY WITH
UPPER 60S WEST TO MID 60S EAST. NORTHWESTERLY FLOW ALOFT WILL
BECOME WELL ESTABLISHED BY SATURDAY EVENING...AND MODELS SHOW A WEAK
SURFACE TROUGH IN RESPONSE TO THE EAST OF THE MOUNTAINS. THIS MAY
KEEP THE OVERNIGHT BOUNDARY LAYER LIGHTLY STIRRED DESPITE A WEAK
MSLP GRADIENT ACROSS THE REGION. PATCHY FROST WILL BE POSSIBLE
AGAIN SUNDAY MORNING AS DEWPOINTS CREEP UP INTO THE LOW TO MID 30S.
LOWS IN THE UPPER 30S AND COLDEST IN THE EASTERN CWA.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
THE LONG TERM PERIOD WILL BE LARGELY CHARACTERIZED BY COOL NW FLOW
AS A LONGWAVE TROUGH REMAINS STALLED OVER MUCH OF NE NORTH AMERICA
EXTENDING SOUTH ALONG THE EASTERN SEABOARD. A SERIES OF SHORTWAVES
WILL DELIVER A COUPLE SHOTS OF COLDER AIR ACROSS THE CAROLINAS
DURING THE PERIOD...BUT LATEST MODEL RUNS SUGGEST THE NW FLOW AND A
MORE OPEN WAVE PATTERN (THAN ONE THATS CUT OFF) SHOULD KEEP PRECIP
LIMITED DURING THIS TIME.
LOOKING DAY TO DAY...ON SUNDAY A WEAK TROUGH IS EXPECTED TO CROSS
THE AREA AS MID LEVEL SHORT WAVE OVER THE UPPER MIDWEST MOVES SE.
THIS TROUGH WILL HAVE LITTLE IMPACT ON THE WEATHER GIVEN THE DEEPER
MOISTURE BEING WELL TO OUR NORTH...SO EXPECT EXPECT FAIR AND WARM
WEATHER AFTER A CHILLY START TO THE DAY WITH TEMPS MODERATING TO THE
MID 70S FOR HIGHS.
ON MONDAY...HIGH PRESSURE WILL BRIEFLY MOVE ACROSS THE AREA...BUT
THE NEXT SHORT WAVE ROTATING AROUND THE LARGE CUTOFF OVER QUEBEC AND
ITS ASSOCIATED SFC COLD FRONT WILL APPROACH LATE IN THE DAY. MID AND
HIGH CLOUDS WILL INCREASE LATE IN THE DAY...BUT PRECIP POTENTIAL
WITH THIS SHORT WAVE LOOKS LIMITED GIVEN LACK OF DEEP MOISTURE.
HIGHS MONDAY NEAR SEASONAL NORMS.
THE AFOREMENTIONED FRONT IS EXPECTED TO MOVE THROUGH MONDAY NIGHT...
WITH DECENT CAA ON TUESDAY IN ITS WAKE. DEEP NW FLOW ON THE BACK
SIDE OF THE LONG WAVE TROUGH WILL CONTINUE OVER OUR AREA RIGHT
THROUGH THURSDAY. EXPECT A 36 HOUR PERIOD OF TEMPS ABOUT 7-10
DEGREES BELOW NORMAL FROM TUESDAY THROUGH WEDNESDAY NIGHT. RIGHT NOW
IT LOOKS LIKE THE COLDEST TEMPS MAY BE EXPERIENCED WEDNESDAY MORNING
WITH LATEST GUIDANCE SUGGESTING LOWS IN THE MID-UPR 30S. HOWEVER
WITH SOME WIND CONTINUING THROUGH THE NIGHT...FROST POTENTIAL COULD
BE LIMITED. FINALLY BY LATE THURSDAY WE`LL SEE THE PATTERN MODIFY
WITH THE TROUGH AXIS SHIFTING EAST AND SOME MODERATING AHEAD OF THE
NEXT SHORT WAVE COMING OUT OF THE CENTRAL ROCKIES.
FINALLY ITS WORTH NOTING THAT WE`VE SEEN A LOT OF SWINGS IN THE
GUIDANCE FOR THIS PERIOD OF THE FORECAST OVER THE PAST SEVERAL
RUNS...ESPECIALLY WITH THE ECMWF...SO CONFIDENCE IN THIS PART OF THE
FORECAST IS NOT ESPECIALLY HIGH. IF THE MODEL TRENDS SUCH AS THOSE
SUGGESTED IN THE 05/12Z ECMWF WERE TO REEMERGE...WE COULD SEE BETTER
CHANCES FOR PRECIP DURING THE MIDDLE OF THE WEEK AND COLDER TEMPS
LASTING LONGER THROUGH THE WEEK THAN CURRENTLY FORECAST.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 700 AM FRIDAY...
CEILINGS ARE HOLDING ABOVE 3K FT AT NEARLY ALL OBSERVING SITES THIS
MORNING. THE MAIN EXCEPTION IS IN THE SOUTHERN PIEDMONT AND
SANDHILLS (AROUND KFAY). RAIN ASSOCIATED WITH A LOW PRESSURE SYSTEM
MOVING ACROSS SC IS MOSTLY FOCUSED NEAR THE NC/SC BORDER...AND WILL
PIVOT ACROSS THE SOUTHERN PIEDMONT AND INTO THE COASTAL PLAIN THIS
MORNING. PERIODS OF MODERATE RAIN WILL BE LIKELY AT KFAY THROUGH
15Z...WITH MVFR CEILINGS AND VSBYS POSSIBLE. FURTHER NORTH...A
NARROW RAINBAND BETWEEN KGSO AND KRDU WILL CONTINUE TO PUSH EAST
TOWARD KRDU AND KRWI THROUGH 15Z. DRIER AIR IS PRESSING INTO THE
AREA FROM THE NORTHWEST...WHICH SHOULD CAUSE THE RAINBAND TO
CONTINUE TO WEAKEN WITH TIME. THUS...ONLY A BRIEF PERIOD OF RAIN
WITH VFR CONDITIONS IS EXPECTED AT KRDU AND KRWI.
AS THE SURFACE LOW MOVES OFFSHORE LATER THIS MORNING...RAIN WILL
GRADUALLY COME TO AN END FROM WEST TO EAST...LINGERING LONGEST FROM
KFAY TO KRWI UNTIL 15-18Z. BRISK NORTHEASTERLY WINDS WILL INCREASE
TO NEAR 15KT AND GUST INTO THE 20-25KT RANGE UNTIL EARLY
AFTERNOON...WHEN THE PRESSURE GRADIENT WILL BEGIN TO DECREASE AND
WINDS WILL BEGIN TO DECREASE TOWARD 10KT. CLEAR SKIES AND LIGHT
NORTH-NORTHEASTERLY WINDS ARE EXPECTED TONIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED THROUGH EARLY NEXT WEEK IN ASSOC/W UPPER
LEVEL RIDGING FOLLOWED BY A PATTERN OF DRY NW FLOW ALOFT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...SMITH
SHORT TERM...SMITH
LONG TERM...NMP
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
330 PM MDT FRI APR 6 2012
.SHORT TERM...GUSTY SOUTHWEST WINDS OVER MUCH OF AREA AHEAD OF UPPER
TROUGH OVER GREAT BASIN. SOME REPORTS OF GUSTS AROUND 50 MPH ACROSS
PLAINS AND ALONG FOOTHILLS. TROUGH STILL EXPECTED TO MOVE ACROSS
WYOMING DURING THE EVENING WITH FLOW ALOFT BECOMING MORE NORTHWEST.
AT THE SURFACE...ASSOCIATED DRY FRONT TO PUSH ACROSS THE AREA WINDS
WINDS BECOMING NORTHWEST. LATEST NAM AND RUC HINTING AT A SLIGHT
INCREASE IN WINDS FOR A SHORT TIME THIS EVENING BEHIND TROUGH AS
SUBSIDENCE IS AT ITS PEAK. COULD SEE SOME GUSTS CLOSE TO HIGH WIND
CRITERIA THIS EVENING. MODELS SHOW WINDS GRADUALLY DECREASING DURING
THE EVENING...WITH HINTS OF A LONGMONT ANTICYCLONE DEVELOPING BY
06Z. RED FLAG WARNING FOR PORTIONS OF AREA TO CONTINUE THROUGH THE
EVENING WITH THE GUSTY WINDS AND LOW HUMIDITY. SHOULD BEGIN TO SEE
SOME REBOUND IN HUMIDITY AFTER 8PM AS TEMPERATURES COOL AND WINDS
DECREASE A BIT. WILL ALSO LEAVE A SLIGHT CHANCE OF STORMS IN THE FAR
NORTHEAST CORNER EARLY IN THE EVENING AS WEAK LIFT WITH TROUGH CLIPS
THAT AREA. THERE ARE SOME RADAR RETURNS SHOWING UP IN WYOMING AT
THIS TIME. FOR TONIGHT...WILL CONTINUE THE DECREASING WIND
TREND...THOUGH MAY STILL BE A BIT GUSTY ALONG NORTHERN AND EASTERN
BORDERS BEHIND EXITING TROUGH. STRONG WINDS STILL POSSIBLE ACROSS
MOUNTAINS AND FOOTHILLS FOR MUCH OF THE NIGHT WITH CROSS MOUNTAIN
FLOW AROUND 50 KTS BEFORE DECREASING EARLY SATURDAY MORNING. MODELS
SHOW WINDS INCREASING SLIGHTLY ACROSS PLAINS DURING THE MORNING
HOURS BEFORE FLOW ALOFT AND LOW LEVEL GRADIENT WEAKENS BY 18Z. WINDS
EXPECTED TO DECREASE ENOUGH ACROSS FAR EASTERN PLAINS TO STAY BELOW
CRITICAL FIRE WEATHER THRESHOLDS. COOLER TEMPERATURES EXPECTED
BEHIND TROUGH WITH TEMPERATURES IN THE 60S ACROSS PLAINS.
.LONG TERM...MODELS SHOW FAIRLY WEAK ZONAL FLOW OVER THE FORECAST
AREA SATURDAY NIGHT THROUGH MONDAY. AN UPPER RIDGE IS TO MOVE
SLOWLY EASTWARD INTO COLORADO...THEN THE FORECAST AREA BY MONDAY
NIGHT. ACCORDING TO THE QPF VERTICAL VELOCITY FIELDS...BENIGN
SYNOPTIC SCALE ENERGY IS PROGGED FOR OUR FORECAST AREA SATURDAY
NIGHT THROUGH MONDAY NIGHT. THE BOUNDARY LAYER WINDS SHOULD ADHERE
TO NORMAL DIURNAL PATTERNS SATURDAY NIGHT INTO SUNDAY EVENING.
MODELS HAVE A WEAK SURGE TO MOVE INTO THE EASTERN PLAINS EARLY
MONDAY MORNING. EAST AND SOUTHEASTERLY FLOW IS PROGGED FOR THE
EASTERN TWO-THIRDS OF THE PLAINS THE REST OF MONDAY INTO TUESDAY.
THERE IS SPARSE MOISTURE PROGGED OVER THE FORECAST AREA SATURDAY
NIGHT INTO MONDAY MORNING. THERE SOME LOW LEVEL MOISTURE IS
INDICATED...ASSOCIATED WITH THE UPSLOPE OVER SOME OF THE PLAINS ON
MONDAY. IT STAYS DRY OTHERWISE THE REST OF MONDAY...WITH A BIT OF
UPPER LEVEL MOISTURE MOVING IN MONDAY NIGHT. THERE IS NO MEASURABLE
PRECIPITATION PROGGED ON THE QPF FIELDS SATURDAY NIGHT THROUGH
MONDAY NIGHT. NO POPS THROUGH THE PERIOD. FOR TEMPERATURES...
SUNDAY`S HIGHS WARM UP 3-6 C FROM SATURDAY`S HIGHS. MONDAY`S HIGHS
ARE ARE 0-2 C WARMER THAN SUNDAY`S. FOR THE LATER DAYS...TUESDAY
THROUGH FRIDAY...MODELS KEEP THE UPPER RIDGE OVER THE CWA TUESDAY
INTO EARLY WEDNESDAY...THEN INCREASING SOUTHWESTERLY FLOW ALOFT IS
PROGGED INTO WEDNESDAY EVENING. AN UPPER TROUGH MOVES IN WEDNESDAY
NIGHT INTO THURSDAY. THE ECMWF SHOWS A BETTER SOLUTION OF THE UPPER
FEATURES FOR A PRECIPITATION EVENT OVER OUR CWA. STRONG WESTERLY
FLOW IS PROGGED THURSDAY NIGHT...THEN STRONG SOUTHWESTERLY ON
FRIDAY. IN FACT THE GFS AND ECMWF BOTH HAVE A JET MAXIMUM OVER THE
CWA ON FRIDAY. MOISTURE IS NOT ALL BAD DURING THE EXTENDED PERIOD
...IN FACT...THE ECMWF HAS DECENT MOISTURE FOR MOST OF THE CWA
WEDNESDAY NIGHT INTO THURSDAY NIGHT. WILL CHANGE LITTLE FROM WHAT
THE 4-7 DAY GFE INIT GRIDS HAVE.
&&
.AVIATION...GUSTY SOUTHWEST WINDS CONTINUING ACROSS AREA AIRPORTS...
A BIT MORE SOUTHERLY AT BJC WITH GUSTS OF 35-45 KTS PREVAILING.
WINDS TO SHIFT TO THE NORTHWEST AROUND 02Z WITH TROUGH PASSAGE WITH
WINDS GRADUALLY DECREASING. MODELS SHOW WINDS SHIFTING TO THE
SOUTHEAST BY MIDNIGHT AS WEAK ANTICYCLONE EXPECTED TO DEVELOP...
THOUGH RUC AND NAM SLOWER WITH DEVELOPMENT WHICH COULD DELAY WIND
DECREASE. SOUTHEAST WINDS TO PREVAIL THROUGH THE DAY SATURDAY...WITH
SPEEDS AROUND 12 KTS BY 18Z. VFR TO CONTINUE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM UNTIL 8 PM MDT THIS EVENING FOR
COZ211-213-215-238-240-242>245.
&&
$$
SHORT TERM...D_L
LONG TERM....KOOPMEINERS
AVIATION...D_L
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
330 PM CDT FRI APR 6 2012
.SYNOPSIS...
ISSUED AT 328 PM CDT FRI APR 6 2012
A SHARP NEGATIVELY TILTED UPPER TROUGH WAS LOCATED ACROSS THE WESTERN
STATES ON THIS MORNING`S 12 UTC OBJECTIVELY ANALYZED UPPER AIR
OBSERVATIONS. SOUTHWEST FLOW IS BECOMING RE-ESTABLISHED ALOFT AS THE
UPPER AND MIDDLE TROPOSPHERIC RIDGE SLOWLY GIVES WAY TO THE
ADVANCING TOUGH TOWARD THE REGION TODAY AND TONIGHT. WIDESPREAD
STRATUS CLOUD COVER ENCOMPASSED ALL OF WESTERN KANSAS AND THE 12 UTC
KDDC SOUNDING INDICATED A 5.5 KFT THICK CLOUD LAYER. THIS CLOUD
LAYER WAS ONLY BEGINNING TO SHOW SLIGHT SIGNS OF ERODING NEAR THE
COLORADO STATE LINE BY MIDDLE AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 328 PM CDT FRI APR 6 2012
IMMEDIATELY FOR TONIGHT, THE STABLE LAYER WILL PROBABLY PRECLUDE THE
POSSIBILITY FOR CONVECTION OVER WESTERN KANSAS THIS EVENING. THE
HIRES-ARW AND LOCAL HRRR MODELS BOTH DEVELOP ISOLATED SUPERCELLS
WELL TO THE SOUTH OF OUR AREA THIS AFTERNOON, OVER THE TEXAS
PANHANDLE, WHILE THE HIRES-NMM PRODUCES NOTHING ALONG THIS DRYLINE
FEATURE THIS EVENING. AS A RESULT, WE`D EXPECT A LITTLE BIT OF
CLEARING ACROSS THE WESTERN COUNTIES TONIGHT, AS THE NAM BOUNDARY
LAYER RELATIVE HUMIDITY INDICATE LOWER VALUES OVER THE SOUTHWEST. A
FRONTAL BOUNDARY EXTENDING FROM MONTANA INTO WYOMING WILL BE THE
BOUNDARY THAT IS DRIVEN THROUGH WESTERN AND CENTRAL KANSAS
OVERNIGHT. DUE TO THE NEAR SURFACE STABLE LAYER, THERE WILL BE A
SIGNIFICANT LACK OF SURFACE BASED INSTABILITY. HOWEVER, THE MOST
UNSTABLE CAPE ON THE NAM MODEL DUE TO THE PRESENT SHALLOW THETA-E
AXIS AHEAD OF THE BOUNDARY ARE ON THE ORDER OF 500-1000 J/KG, IS MORE
THAN ENOUGH FOR A FEW STOUT UPDRAFTS AND BRIEF SMALL HAILCORES
THROUGH THE LATE OVERNIGHT THROUGH CENTRAL KANSAS. THE BEST
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE FOCUSED ROUGHLY EAST
OF A SCOTT CITY TO MINNEOLA AND ASHLAND LINE. ONCE THE BOUNDARY
SLIPS THROUGH THE AREA DEEP DRY AIR WILL BE IN PLACE TO ALLOW FULL
SUN FOR THE ENTIRE FORECAST AREA ON SATURDAY. THE DAYTIME WILL
FAIRLY BREEZY WITH A STRONG PRESSURE GRADIENT THROUGH AROUND 18Z
BEFORE AN ARE OF HIGH PRESSURE BEGINS TO DOMINATE THE CENTRAL
PLAINS STATES, EASING THE SURFACE PRESSURE GRADIENT AND SLACKENING
WINDS. WEAK COLD ADVECTION SHOULD TEMPER THE SURFACE HEATING,
RELEGATING GENERALLY TO THE LOW AND MID 60`S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 312 PM CDT FRI APR 6 2012
ON THE NEAR SIDE OF THE 4 TO 7 DAY EXTENDED FORECAST, THERE NOW
APPEARS THAT THERE WILL BE ENOUGH OVERRIDING CONDITIONS OF THE FRONT
ACROSS OKLAHOMA ON MONDAY. THEREFORE, I ADDED A FEW LOWER END POPS
TO THE MONDAY PERIOD, WHICH WERE NOT PREVIOUSLY IN THERE. WILL
BRING IN 20 POPS ACROSS OUR SOUTHERN 1 TO 2 TIER OF COUNTIES EARLY
MONDAY MORNING, AND THEN CONCENTRATE 20 POPS NORTH AND 30 POPS SOUTH
FOR SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON. THE OVER RUNNING
WILL DIMINISH MONDAY NIGHT, BUT SLIGHT STORM CHANCES WILL CONTINUE
ALONG AND NEAR THE OKLAHOMA BORDER. SHOWERS AND STORM CHANCES WILL
CONTINUE, INCREASE AND SPREAD ACROSS ALL OF OUR CWA BY WEDNESDAY. A
WARM FRONT WILL PUSH NORTHWARD TUESDAY NIGHT AND BE NEAR A JOHNSON
CITY TO DODGE CITY TO PRATT LINE BY 12Z WEDNESDAY. THE FRONT WILL
WANDER NORTH AND SOUTH ACROSS OUR FORECAST AREA WEDNESDAY AND
THURSDAY, WITH THE UPPER TROUGH MOVING TO JUST WEST OF SOUTHWESTERN
KANSAS BY 12Z THURSDAY. THIS WILL KEEP GOOD SYNOPTIC LIFT OVER
SOUTHWEST KANSAS. THEREFORE THE HIGHEST POPS IN THE 50 TO 55
PERCENT RANGE WILL BE ACROSS OUR EASTERN 1/2 OF THE CWA WEDNESDAY
NIGHT, AND SHIFT EASTWARD ACROSS OUR NORTHEAST 1/2 OF THE FORECAST
AREA DURING THE DAY THURSDAY BUT REDUCE TO 40 PERCENT. BY FRIDAY,
THE UPPER WAVE SHOULD BE EAST OF CENTRAL KANSAS, WITH SKIES BECOMING
MOSTLY CLEAR/MOSTLY SUNNY IN OUR WEST AND PARTLY CLOUDY IN OUR
EASTERN CWA. THROUGH THE MONDAY TO FRIDAY PERIOD, SOME SPOTS MAY
RECEIVE AS MUCH AS 0.66 INCH OF RAIN, MAINLY ACROSS OUR EASTERN 2
TIER OF COUNTIES.
AS FOR TEMPERATURES, SUNDAY MORNING IS THE MOST INTERESTING AND
CHALLENGING. USING THE LOW END VALUES OF THE MINXXX (GCK, DDC, ETC)
GUIDANCE TO POPULATE THE SAT NT/SUN MORN MIN T`S, AND THE RESULT WAS
AS COLD AS 32F AT SCOTT CITY, 34F NORTHWEST OF A DIGHTON TO JOHNSON
CITY LINE, AND AROUND 35F OR BELOW NORTHWEST OF A HAYS TO SUBLETTE
TO NEAR HUGOTON LINE. AT FIRST, I LEANED TOWARD A FROST ADVISORY
ACROSS OUR NORTHWEST TIER OF COUNTIES, BUT DECIDED TO USE A MORE
GRADUAL APPROACH, AND INTRODUCED PATCHY FOG IN THE FORECAST FOR
SUNDAY MORNING AND WILL UPDATE THE HWO TO REFLECT THIS AS WELL.
MINS SHOULD INCREASE AS SOON AS MON MORNING SINCE THE WARM FRONT
WILL MOVE CLOSER, THE OVER RUNNING CLOUDS WILL BLANKET THE AREA, AND
WINDS WILL BE LIGHT BUT STILL STRONG ENOUGH TO KEEP WARM, MOIST AIR
FILTERING IN FROM THE SOUTH. MINIMUM TEMPERATURES MONDAY MORNING
WILL
RANGE FROM THE MID 40S IN OUR NORTH TO NEAR 50F DEGREES IN OUR
SOUTH. MINS WILL BE SIMILAR TUESDAY THROUGH THURSDAY, THEN COOL A
BIT INTO THE LOWER 40S NW TO THE MID TO UPPER 40S SE BY FRIDAY. MAX
TEMPS WILL BE STRONGLY INFLUENCED BY THE PERIODIC PRECIPITATION,
WITH SUNDAY STARTING OUT IN THE UPPER 60S TO LOWER 70S, WARM TO THE
MID TO UPPER 70S IN OUR SOUTHWEST WEDNESDAY SOUTHWEST OF THE FRONT,
AND IN THE LOWER 60S ACROSS OUR NORTHEAST COUNTIES. THE FRONT COULD
BE NUDGING FARTHER NORTH ON THURSDAY, WITH RESULTANT MAX TEMPS
RESPONDING LIKEWISE WITH HIGHS IN THE MID 70S ACROSS OUR SOUTHWEST
AND THE MID 60S IN OUR NORTHEAST SECTIONS. FRIDAY WILL SEE A LITTLE
COOL AIR RETURN ON THE BACK SIDE OF THE EXITING TROUGH, WITH HIGHS
REACHING NEAR 70F DEGREES IN OUR SOUTHWEST AND THE MID 60S IN OUR
NORTHEAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 132 PM CDT FRI APR 6 2012
WIDESPREAD MVFR AND IFR CEILINGS ARE NOT EXPECTED TO IMPROVE UNTIL A
COLD FRONT SWEEPS THROUGH THE AREA OVERNIGHT. ALTHOUGH LEE TROUGHING
IS INCREASING THE WIND FIELD OVER WESTERN KANSAS, THE STRATUS LAYER
IS DEEP ENOUGH TO MAINTAIN SLOW STRATUS AT LEAST AT HYS AND DDC
THROUGH THE EVENING. GCK WILL LIKELY REMAIN IN THE IFR STRATUS AS
WELL, BUT THE CLEARING LINE MAY GET CLOSE TO THE TERMINAL IN THE
EVENING. THE COLD FRONT WILL SWEEP THROUGH WESTERN KANSAS OVERNIGHT
AND MOVE SOUTH OF THE AREA BY 12 UTC SATURDAY. SCATTERED TO NUMEROUS
SHOWERS/CB`S WILL ACCOMPANY THE FRONT AS IT MOVES THROUGH THE
AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 66 36 68 / 40 30 0 0
GCK 44 64 34 71 / 20 10 0 0
EHA 44 64 37 72 / 10 10 0 0
LBL 47 66 37 71 / 10 10 0 0
HYS 49 65 35 68 / 70 40 0 0
P28 54 68 39 69 / 60 50 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1133 AM MDT FRI APR 6 2012
.UPDATE...
ISSUED AT 536 AM MDT FRI APR 6 2012
JUST COMPLETED AN UPDATE. PER CURRENT OBSERVATIONS...MAJORITY OF
FOG AND DRIZZLE IS CONFINED TO THE FAR WEST AND SOUTHWEST PORTION
OF THE AREA. AS YESTERDAY...THE HRRR IS CATCHING THIS VERY WELL.
SO REDUCED THE COVERAGE OF THE FOG AND DRIZZLE PER REASONING GIVEN
ABOVE. OTHERWISE...JUST ADJUSTED HOURLY GRIDS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 344 AM MDT FRI APR 6 2012
FORECAST PROBLEMS WILL BE ALL ELEMENTS THROUGH TONIGHT AND
WINDS/FIRE WEATHER CONCERNS ON SATURDAY. SATELLITE CONTINUING TO
SHOW AN AMPLIFIED/AMPLIFYING PATTERN ACROSS THE NORTHERN HEMISPHERE.
NEXT IN A SERIES OF TROUGHS IS DIGGING/SPLITTING OFF INTO THE
WESTERN PORTION OF THE COUNTRY AT THIS TIME. AIR MASS AT LOW LEVELS
IS MOIST WITH VERY DRY AT MID LEVELS.
AT JET LEVEL THE MODELS DID FINE BUT TENDED TO HAVE THE UPPER
TROUGH/JET SEGMENT TO OUR WEST A LITTLE TO FAR TO THE EAST.
THE NAM AND ECMWF WERE DOING WELL ON THE SURFACE WIND AND PRESSURE
FIELD. OVER THE AREA MODELS DID NOT HAVE THE COOLER AIR OVER THE
STATE FAR ENOUGH WEST. WITH THIS AND OVERALL THE GFS AND CANADIAN
WERE DOING A LITTLE BETTER THAN THE UKMET.
TODAY/TONIGHT...PRETTY TIGHT GRADIENT DEVELOPS DURING THE DAY WITH
MODEST PRESSURE FALLS. THIS WOULD DEFINITELY SUPPORT WINDY. AS THE
DAY SHIFT BROUGHT UP...LINGERING CLOUD COVER COULD KEEP THE FULL
POTENTIAL OF THE WIND FROM BEING REACHED. LATEST MESOSCALE MODEL
OUTPUT HAS COME IN AND NOW HOLDS ONTO THE CLOUDS EVEN LONGER AND
TEMPERATURES EVEN COOLER. SO AT THIS TIME WILL NOT ISSUE A WIND
ADVISORY AND CONTINUE THE WINDY WORDING. THE LATEST NAM...RUC AND
HRRR SHOW CLEARING OCCURRING ON THE WEST AND EAST ENDS OF THE
FORECAST AREA WITH THE CLOUDS HOLDING ON THE LONGEST IN THE CENTER.
AND FROM PREVIOUS EXPERIENCE...THAT IS A REASONABLE SOLUTION. AS A
RESULT...SIGNIFICANTLY COOLED OFF MAXES FROM EARLIER THINKING.
CURRENT DRIZZLE AND FOG THIS MORNING LOOK IN GOOD SHAPE AND WILL
CONTINUE TO MONITOR THROUGH THE END OF THE SHIFT. MODELS ARE SHOWING
SOME JET LIFT FROM LATE THIS AFTERNOON INTO THIS EVENING. MAIN
SHORTWAVE TROUGH ON THE FRONT SIDE OF THE UPPER TROUGH MOVES THROUGH
LATE IN THE DAY INTO THE NIGHT BUT THE BRUNT OF ITS LIFT IS FURTHER
NORTH AND WEST. BECAUSE OF THE COOLER MAXES NOW EXPECTED...
INSTABILITY WILL BE LESS AND CINH WILL BE MORE. GFS AND NAM
DEFINITELY SHOW THAT. ON TOP OF THIS COOLER STABLE LAYER...THE MODELS
BRING A VERY STRONG WARM/DRY LAYER ALOFT. AS A RESULT OF THIS HAVE
REMOVED ALL MENTION OF THUNDERSTORMS UNTIL 03Z WITH THE BEST CHANCE
BEGINNING AT 06Z. THIS IS WHEN THE INHIBITION IS THE WEAKEST AND
WHEN THE FRONT STARTS MOVING THROUGH. EXPECT PRECIPITATION TO BE
SPOTTY WITH LITTLE TO NO THREAT OF SEVERE WEATHER.
PRETTY TIGHT GRADIENT AND HIGH THREE HOUR PRESSURE RISES OCCUR
BEHIND THE FRONT. SO WILL PROBABLY BE WINDY...ESPECIALLY RIGHT
BEHIND THE FRONT AND THEN SLOWLY SLACKEN.
SATURDAY/SATURDAY NIGHT...PER COLLABORATION HAVE DECIDED NOT TO ISSUE
A FIRE WEATHER WATCH. FIRST WE ARE NOT THAT FAR REMOVED FROM THE
WIDESPREAD MODERATE TO HEAVY RAINS. THERE HAS NOT BE A LOT OF CHANCE
TO DRY OUT WITH LITTLE SUNSHINE...COOLER TEMPERATURES AND NOT A LOT
OF WIND. DRIER AIR DOES COME IN BEHIND THE FRONT BUT IT LOOKS LIKE
THE HIGHEST WINDS WILL BE IN THE MORNING. SO FOR THOSE REASONS
DECIDED NOT TO ISSUE A WATCH. DAY SHIFT WILL HAVE TO KEEP WATCHING
THIS. 850 MB/2 METER/NWP SUPPORT GOING TOWARD A COOLER DAY. LOOKS
LIKE A DECENT AMOUNT OF COOL AIR UPSTREAM BEHIND THIS FRONT...AND
WILL GO TOWARD THE COOLER GUIDANCE AND DID ADJUST DOWN SLIGHTLY.
FOR TONIGHT...WINDS START OUT LIGHT IN THE EVENING AND THEN QUICKLY
SHIFT TO THE SOUTH AND INCREASE SO THE LOWS WILL BE EARLY.
SUNDAY/SUNDAY NIGHT...BREEZY TO WINDY CONDITIONS ARE EXPECTED
THROUGH THE MIDDLE OF THE DAY IN ADVANCE OF A FRONT THAT WILL MOVE
IN LATE IN THE DAY. SO HIGH TEMPERATURES WILL GET A LITTLE TRICKY...
ESPECIALLY IN THE NORTHWEST PORTION. ONLY MADE SLIGHT ADJUSTMENTS TO
THE HIGH TEMPERATURE FORECAST.
THANKS TO ALL WHO COLLABORATED.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 344 AM MDT FRI APR 6 2012
AN AMPLIFIED TROUGH-RIDGE-TROUGH PATTERN WILL BE IN PLACE ACROSS THE
CONUS BY MONDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. THIS
PATTERN WILL FAVOR DRY CONDITIONS ON MONDAY...WITH SEASONABLY MILD
TEMPERATURES IN THE 60S. A SERIES OF WEAK SHORTWAVE TROUGHS WILL
PASS ACROSS THE NORTHERN MISSISSIPPI VALLEY/GREAT LAKES REGION
MONDAY NIGHT...WITH A BACK DOOR COLD FRONT DROPPING SOUTH OVER THE
CENTRAL HIGH PLAINS MONDAY NIGHT/TUESDAY. THE RESULT WILL BE
EASTERLY BL FLOW AND COOLER TEMPS ALOFT TUESDAY AND
WEDNESDAY...ALONG WITH INCREASING CLOUD COVER. THIS COULD LIMIT
DAYTIME WARMING BOTH DAYS. I COOLED HIGH TEMPS TO UPPER 50S TUE/WED
IN THE EAST AND MID-UPPER 60S IN THE WEST AND SOUTH TO STAY WITHIN
COLLABORATION...HOWEVER THIS STILL MAY BE TOO WARM.
THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS TUESDAY LIMITED TO
THE SOUTHERN PART OF THE CWA NEAR THE STALLED FRONT. BY TUESDAY
NIGHT A NEGATIVELY TILTED TROUGH WILL BEGIN TO DEVELOP TOWARD THE
GREAT BASIN. ISENTROPIC UPGLIDE AND GULF MOISTURE BUILDS NORTH
TOWARDS THE CENTRAL HIGH PLAINS...WITH SHOWER/THUNDERSTORM CHANCES
OVERSPREADING THE CWA TUESDAY NIGHT/WEDNESDAY. THE STALLED FRONT
WILL BEGIN TO LIFT NORTH WEDNESDAY AFTERNOON AS A WARM FRONT...WITH
INCREASING INSTABILITY AND SHEAR ALONG AND SOUTH OF THIS FRONT
BUILDING NORTH INTO THE CWA. THE BEST CHANCE FOR SEVERE LOOKS TO BE
OVER SW KS...THOUGH A FEW STRONG/SEVERE STORMS CANT BE RULED OUT
FURTHER NORTH OVER CWA. SHOWER/THUNDERSTORM COVERAGE WILL INCREASE
WEDNESDAY NIGHT AND THURSDAY AS THE UPPER TROUGH DEEPENS BECOMING A
CLOSED LOW CENTERED OVER NW KANSAS BY THURSDAY AFTERNOON/EVENING.
00Z GUIDANCE HAS COME INTO BETTER AGREEMENT ON THIS FEATURE
THURSDAY/THURSDAY NIGHT...WITH THE AREA IN LINE FOR DECENT RAINFALL.
SINCE THERE HAS NOT BEEN A LOT OF RUN-RUN AGREEMENT BETWEEN MODELS...
I DID NOT WANT TO INCREASE POPS OUTSIDE OF CHANCE CATEGORY. PRECIP
CHANCES DIMINISH FROM THE WEST TO EAST THURSDAY NIGHT AS SHORTWAVE
RIDGING DEVELOP OVER THE CENTRAL HIGH PLAINS IN THE WAKE OF THE
DEPARTING UPPER LOW. DRY CONDITIONS AND WARMING TEMPERATURES
CURRENTLY EXPECTED NEXT FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1133 AM MDT FRI APR 6 2012
STRATUS IS FIRMLY ENTRENCHED ACROSS THE ENTIRE AREA...HOWEVER...IT
IS BEGINNING TO ERODE ON THE WESTERN FLANK. EXPECT THE CIG TO
RAISE TO MVFR AT KGLD OVER THE NEXT HOUR OR SO AND SCATTER OUT
AROUND 21Z. KMCK IS A WILD CARD WITH NUMERICAL GUIDANCE DIVERGING
ON IF THE TERMINAL WILL SCATTER OUT. HAVE TAKEN AN OPTIMISTIC
APPROACH BASED ON CURRENT TRENDS AND WILL SCATTER OUT MVFR CIGS AROUND
23Z. A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT AND WINDS WILL
SWITCH TO THE NORTHWEST AND STAY GUSTY THROUGH REST OF PERIOD.
THERE IS A SLIGHT CHANCE FOR TS AT KMCK BETWEEN 02-05Z AHEAD OF
FRONTAL PASSAGE BUT CONFIDENCE TOO LOW TO INCLUDE IN TAFS DUE TO
UNCERTAINITY IN COVERAGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM....DR
AVIATION...BAS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
310 PM MDT FRI APR 6 2012
.DISCUSSION...WATER VAPOR IMAGERY SHOWS UPPER RIDGING ALONG THE
MISSISSIPPI VALLEY AND AN UPPER TROUGH CROSS THE NORTHERN CONUS.
DEEP SOUTHWESTERLY FLOW ALOFT IS QUICKLY DEVELOPING ACROSS THE
REGION WITH A STRONG WAVE NOW CROSSING THE AREA. SURFACE ANALYSIS
SHOWS LOW PRESSURE STRADDLING THE CWA WITH STRONG SOUTHERLY WINDS
ACROSS THE CENTRAL SOUTH DAKOTA PLAINS. ON THE BACKSIDE OF THE
LOW...GUSTY WEST/SOUTHWESTERLY WINDS ARE ACROSS EAST CENTRAL
WYOMING...AND COOLER TEMPS AND NORTHWESTERLY WINDS ARE NOTED
ACROSS NORTH CENTRAL WYOMING. RADAR SHOWS A LINE OF SHOWERS AND
STORMS ACROSS THE BLACK HILLS STRETCHING TOWARD NORTHWEST SOUTH
DAKOTA.
TONIGHT...PRECIP WILL CONTINUE TO PUSH EASTWARD AHEAD OF
THE DRY LINE/COLD FRONT CONVERGING ACROSS NORTHEAST WYOMING. LATEST
RUC SHOWS SURFACE BASED CAPE OF AROUND 1000 J/KG EXTENDING JUST
AHEAD OF THE FRONTAL BOUNDARIES...WITH DEEP SHEAR THROUGH THE LOW
TO MID LEVELS. WITH MARGINAL INSTABILITY...A FEW STORMS HAVE
ALREADY PRODUCED MODERATE SIZE HAIL. THERE IS SOME POTENTIAL FOR
ANOTHER STORM OR TWO TO PRODUCE MARGINALLY SEVERE HAIL...BUT
WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. THE BEST DYNAMICS WILL
BE ACROSS NORTHWEST SOUTH DAKOTA WHERE RADAR SHOWS SOME STORMS
BEGINNING TO DEVELOP.
ADVISORY CRITERIA WINDS HAVE CONTINUE ACROSS MUCH OF THE SOUTH
DAKOTA PLAINS TODAY...BUT HAVE FAILED TO REACH ADVISORY CRITERIA
IN THE PLAINS CLOSER TO THE BLACK HILLS. MODELS ARE SUGGESTING
GUSTY WEST/SOUTHWEST WINDS WILL PUSH INTO WEST CENTRAL/SOUTHWEST
SOUTH DAKOTA THIS EVENING BEHIND THE DRY LINE. SO WILL KEEP THE
ADVISORY GOING TILL 900 PM MDT EVEN FOR THE FOOTHILLS. A COLD
FRONT WILL THEN PUSH THROUGH THE AREA LATER THIS EVENING...ENDING
THE STRONG WINDS ACROSS WEST CENTRAL/SOUTHWEST SOUTH DAKOTA
PLAINS. IT LOOKS LIKE WINDS OVER NORTHWEST SOUTH DAKOTA WILL
REMAIN AT ADVISORY CRITERIA OVERNIGHT GIVEN STRONG COLD AIR
ADVECTION...SO HAVE EXTENDING THE ADVISORY TONIGHT AND THROUGH
SATURDAY.
THE UPPER LOW WILL SWING NORTHEASTWARD INTO CANADA SATURDAY AS IT
BECOME NEGATIVELY TILTED. LATEST MODEL RUNS SHOW LINGERING PRECIP
WILL STAY NORTH OF THE CWA SATURDAY...SO HAVE REMOVED POPS. EXCEPT
FOR THE GUSTY WEST/NORTHWEST WINDS...SHOULD BE A QUIET DAY WITH
MOST AREAS SEEING SUNSHINE. HIGH PRESSURE WILL DEVELOP ACROSS THE
AREA SUNDAY BRINGING MORE SUNSHINE AND WINDS NORTHWEST WINDS AT 10
TO 20 MPH...THOUGH WINDS ACROSS NORTHWEST SOUTH DAKOTA COULD BE
STRONGER. MAX TEMPS IN THE MID 50S TO MID 60S ARE EXPECTED.
.EXTENDED...
MONDAY THROUGH FRIDAY
THE EXTENDED FORECAST REMAINS VERY COMPLICATED GIVEN A FRACTURING
WAVE OVER THE ROCKIES/UNKNOWN POSITIONING OF THE JAMES BAY
VORTEX/AND THE DEGREE OF WESTERN ATLANTIC RIDGING. FORECAST MODELS
TAKE A SPLIT PER DETAILS MID NEXT WEEK ON...WITH CLEAR DIVISION IN
ECMWF AND GFS SOLUTIONS BY THE END OF THE WEEK. A DEEP HUDSON BAY
VORTEX WITH BLOCKED DOWNSTREAM FLOW WOULD CERTAINLY OFFER MUCH
COOLER THERMAL FIELDS INTO THE AREA...AND THE GEM/ECMWF SUPPORT A
SOLUTION IN THIS DIRECTION GIVEN A WESTERN BIASED EASTERN CONUS
UPPER TROUGH. GIVEN TYPICAL POOR HANDLING OF HUDSON/JAMES BAY VORTEX
POSITIONING...WITH FORECAST MODELS TENDING TO BE BIASED TOO FAR EAST
/ESP THE GFS/ WILL SIDE HEAVIER TOWARD AN ECMWF/GEM SOLUTION. THIS
CONCERN COMBINED WITH SIGNALS FOR CONTINUED EASTERLY COMPONENT TO
THE FLOW SUPPORTS THE COOL SIDE OF GUIDANCE THROUGH THE MAJORITY OF
THE PERIOD ATTM...UNTIL TRENDS ARE ESTABLISHED. ALSO RETAINED POPS
PER THE THUR SYSTEM. TYPICALLY POORLY HANDLED FRACTURING MID LEVEL
IMPULSE CERTAINLY IS FROM BEING ASCERTAINED ATTM...WITH FORECAST
CONSISTENCY PREFERRED. CERTAINLY LOOKS TO BE A RAIN EVENT ALTHOUGH
SNOW MAY BE POSSIBLE WITH THE EXIT OF THIS SYSTEM. HENCE...ADDED A
SNOW MENTION...ESP IN LIGHT OF ECMWF/GEM THERMAL FIELDS.
OTHERWISE...DRY WEATHER EXPECTED OUTSIDE WED NIGHT-THUR ATTM.
&&
.AVIATION.../18Z TAFS/
DEEPENING LOW PRESSURE WILL FORCE A COLD FRONT THROUGH THE REGION IN
THE PERIOD. MAINLY VFR CONDITIONS THIS AFTERNOON WITH POCKETS OF
MVFR CIGS AWAY FROM THE TERMINALS. WINDS WILL VEER NW BY EARLY
EVENING WITH A FROPA...AS A GENERAL TREND...REMAINING GUSTY. WINDS
WILL BE VERY TRICKY OVER NE WY...INCLUDING GCC GIVEN A STALLED FRONT
IN PLACE. HAVE RETAINED VRBL MENTION THERE ATTM...GIVEN UNCERTAINTY
OF BOUNDARY PLACEMENT. GUIDANCE INDICATED A STRONG SOUTHERLY WIND
AHEAD OF THE COLD FRONT THERE. HOWEVER...LATEST RUC INDICATES THAT
THE SFC FRONT WILL REMAIN OVER OR JUST SOUTH OF THE TERMINAL. WILL
MONITOR. OTHERWISE...SHRA ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF
THE COLD FRONT...POSSIBLY AFFECTING RAP. DETERIORATING CONDITIONS
EXPECTED AT GCC THIS EVENING GIVEN A PERIOD SNOW SHOWERS THERE. HAVE
TRENDED TO IFR CIGS. CONDITIONS WILL IMPROVE SAT AS HIGH PRESSURE
BUILDS INTO THE AREA.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
BENNETT-CUSTER CO PLAINS-FALL RIVER-HAAKON-HERMOSA FOOT
HILLS-JACKSON-MELLETTE-PENNINGTON CO PLAINS-RAPID CITY-
SHANNON-SOUTHERN FOOT HILLS-TODD-TRIPP.
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR BADLANDS AREA-SOUTHWESTERN SOUTH DAKOTA.
WIND ADVISORY UNTIL 9 PM MDT SATURDAY FOR BUTTE-HARDING-NORTHERN
MEADE CO PLAINS-PERKINS-SOUTHERN MEADE CO PLAINS-ZIEBACH.
WY...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR LOWER ELEVATIONS OF CROOK AND WESTON COUNTIES-
SOUTHERN CAMPBELL.
&&
$$
SHORT TERM...13
LONG TERM...JC
AVIATION...JC
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1129 AM MDT FRI APR 6 2012
.DISCUSSION...LATEST SURFACE ANALYSIS SHOWS DRIFTING LOW PRESSURE
ACROSS THE BLACK HILLS INTO SOUTHEAST WYOMING ALONG A STATIONARY
FRONT. GUSTY SOUTHERLY WINDS AHEAD OF THE LOW IS BRINGING ADVISORY
CRITERIA WINDS TO MOST LOCATIONS ACROSS THE SOUTH DAKOTA PLAINS.
FORECAST PACKAGE OVERALL IN GOOD SHAPE. HAVE MADE MINOR
ADJUSTMENTS TO POPS TODAY INCLUDING INCREASING POPS TO LIKELY
ACROSS NORTHWEST SOUTH DAKOTA GIVEN THE BEST DYNAMICS LATE THIS
AFTERNOON BEING OVER THAT AREA INTO WESTERN NORTH DAKOTA. MADE
MINOR TWEAKS TO TEMPS ACROSS PARTS OF NORTHEAST WYOMING WITH THE
LATEST OBS SHOWING COOLER AIR/NORTHWEST WINDS INTO NORTH CENTRAL
WYOMING. NO OTHER CHANGES NEEDED AT THIS TIME.
&&
.AVIATION.../18Z TAFS/
DEEPENING LOW PRESSURE WILL FORCE A COLD FRONT THROUGH THE REGION IN
THE PERIOD. MAINLY VFR CONDITIONS THIS AFTERNOON WITH POCKETS OF
MVFR CIGS AWAY FROM THE TERMINALS. WINDS WILL VEER NW BY EARLY
EVENING WITH A FROPA...AS A GENERAL TREND...REMAINING GUSTY. WINDS
WILL BE VERY TRICKY OVER NE WY...INCLUDING GCC GIVEN A STALLED FRONT
IN PLACE. HAVE RETAINED VRBL MENTION THERE ATTM...GIVEN UNCERTAINTY
OF BOUNDARY PLACEMENT. GUIDANCE INDICATED A STRONG SOUTHERLY WIND
AHEAD OF THE COLD FRONT THERE. HOWEVER...LATEST RUC INDICATES THAT
THE SFC FRONT WILL REMAIN OVER OR JUST SOUTH OF THE TERMINAL. WILL
MONITOR. OTHERWISE...SHRA ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF
THE COLD FRONT...POSSIBLY AFFECTING RAP. DETERIORATING CONDITIONS
EXPECTED AT GCC THIS EVENING GIVEN A PERIOD SNOW SHOWERS THERE. HAVE
TRENDED TO IFR CIGS. CONDITIONS WILL IMPROVE SAT AS HIGH PRESSURE
BUILDS INTO THE AREA.
&&
.PREV DISCUSSION... /ISSUED 324 AM MDT FRI APR 6 2012/
DISCUSSION...CURRENT SURFACE ANALYSIS PLACES LOW OVER SOUTHWESTERN
WYOMING...WHILE HIGH LINGERS NEAR LAKE SUPERIOR. UPPER LEVEL
ANALYSIS PLACES RIDGE AXIS STRETCHING FROM NEAR THE RED RIVER
VALLEY SOUTHWARD INTO THE CENTRAL/SRN PLAINS...WHILE TROF PUSHES
INTO THE ROCKIES. INITIAL WAVE AHEAD OF THE TROF HAS PRODUCED SOME
OVERNIGHT SHOWERS/THUNDERSTORMS OVER THE WRN CWA.
FOR TODAY...SFC LOW LIFTS TO THE NORTHEAST ACROSS WYOMING...PUSHING
INTO WRN ND/FAR NERN SD THIS EVENING WHILE UPPER TROF SHIFTS
NORTHEAST. THIS WILL KEEP MOST OF THE LIFT TO THE
NORTH/NORTHWEST...THOUGH SOME SHOWERS WILL STILL DEVELOP OVER
OUR AREA...PARTICULARLY OVER THE NWRN CWA CLOSER TO THE LOW...AND
OVER S CTRL THIS EVE WHERE SECONDARY WAVE WILL SLIDE THROUGH. A
FEW THUNDERSTORMS WILL ALSO BE POSSIBLE WITH MODEST INSTABILITY IN
PLACE. LATER TONIGHT...A FEW SNOW SHOWERS WILL BE POSSIBLE AS
COOLER AIR WORKS IN BEHIND PASSING COLD FRONT...PARTICULARLY OVER
WRN CWA. THE MAIN CONCERN FOR OUR AREA WILL BE WINDS WITH
TIGHTENING PRESSURE GRADIENT AS SFC LOW SHIFTS NORTHEAST. HAVE
UPPED WINDS ACROSS THE AREA FOR THIS AFT/EARLY EVE AND WILL PULL
ADVISORY FURTHER WEST. WINDS WILL DIMINISH SOME LATER TONIGHT AS
LOW LIFTS OVER LAKE WINNIPEG.
ON SATURDAY...A FEW LINGERING RAIN/SNOW SHOWERS WILL BE POSSIBLE
IN THE MORN OVER FAR NWRN CWA. OTHERWISE...DRIER AIRMASS WORKS ITS
WAY IN BRINGING CLEARING SKIES. WINDY/BREEZY CONDITIONS WILL
REMAIN AS PRESSURE GRADIENT REMAINS RATHER TIGHT IN THE WAKE OF
DEPARTING LOW...THOUGH WINDS WILL TAPER LATE DAY INTO THE EVE.
FOR SUNDAY...RIDGE BUILDING TO THE WEST WILL BRING DRY CONDITIONS
AND WARMING TEMPERATURES.
EXTENDED...AN UPPER LEVEL RIDGE WILL DOMINATE THE WEATHER ACROSS THE
NRN PLAINS EARLY TO MID NEXT WEEK...AND BRING DRY WEATHER ALONG WITH
ABOVE AVERAGE TEMPS TO THE REGION. MEDIUM RANGE GUIDANCE IS SHOWING
CONSISTENCY AND CONTINUITY IN LIFTING A STRONG AND NEGATIVELY TILTED
UPPER TROF ACROSS THE CNTRL/NRN PLAINS FOR THE LATTER HALF OF THE
WEEK. THIS HAS THE POTENTIAL TO PRODUCE WIDESPREAD AND SUBSTANTIAL
PRECIPITATION TO THE REGION. HOWEVER...THE BIGGEST QUESTION IS HOW
STRONG THE UPPER RIDGE WILL BE OVER THE NRN PLAINS AS THE TROF
APPROACHES AND WHETHER OR NOT THIS WILL KEEP THE MORE SIGNIFICANT
PRECIPITATION TO OUR SOUTH. MINIMAL COLD AIR IS EXPECTED WITH THIS
SYSTEM. THUS...MOST IF NOT ALL OF THE PRECIPITATION WILL REMAIN IN
LIQUID FORM.
FIRE WEATHER...GUSTY SOUTHERLY TO WESTERLY WINDS WILL DEVELOP
OVER THE AREA TODAY AS A LOW PRESSURE SYSTEM PASSES FROM WYOMING
INTO THE WESTERN DAKOTAS. THE AREA WITH THE LOWEST RELATIVE
HUMIDITY WILL BE OVER NORTHEAST WYOMING INTO FAR SOUTHWEST SOUTH
DAKOTA WHERE NEAR CRITICAL FIRE WEATHER CONDITONS WILL BE
POSSIBLE. ON SATURDAY...A DRIER AIRMASS WILL WORK INTO THE
AREA...WITH RELATIVE HUMIDITY VALUES IN THE MID TEENS TO THE MID
20S. WINDS WILL BE WESTERLY TO NORTHWESTERLY AND GUSTY IN THE WAKE
OF A COLD FRONT. THE DRIEST AREA WILL AGAIN BE OVER PORTIONS OF
NORTHEAST WYOMING AND FAR SOUTHWEST SOUTH DAKOTA WHERE CRITICAL
FIRE WEATHER CONDITIONS WILL BE POSSIBLE.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
BENNETT-BUTTE-CUSTER CO PLAINS-FALL RIVER-HAAKON-HARDING-
HERMOSA FOOT HILLS-JACKSON-MELLETTE-NORTHERN MEADE CO
PLAINS-PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SHANNON-
SOUTHERN FOOT HILLS-SOUTHERN MEADE CO PLAINS-
STURGIS/PIEDMONT FOOT HILLS-TODD-TRIPP-ZIEBACH.
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR BADLANDS AREA-SOUTHWESTERN SOUTH DAKOTA.
WY...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR LOWER ELEVATIONS OF CROOK AND WESTON COUNTIES-
SOUTHERN CAMPBELL.
&&
$$
SHORT TERM...WFO UNR
LONG TERM....WFO UNR
AVIATION...JC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 PM CDT FRI APR 6 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
230 PM CDT FRI APR 6 2012
FORECAST CONCERNS INCLUDE RAIN CHANCES SATURDAY...DRY AND BREEZY
CONDITIONS SUNDAY.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGHLY AMPLIFIED RIDGE
OF HIGH PRESSURE EXTENDING FROM MEXICO THROUGH THE MIDWEST/UPPER
MISSISSIPPI RIVER REGION...INTO WESTERN ONTARIO CANADA. AT THE
SURFACE...HIGH PRESSURE DOMINATED THE CENTRAL CONUS WITH THE CENTER
OF THE HIGH LOCATED OVER EASTERN ONTARIO CANADA. EAST/SOUTHEAST COOL
AND DRY OUTFLOW FROM THE HIGH KEEPING TEMPERATURES IN THE 50S WITH
RELATIVE HUMIDITY LEVELS IN THE LOWER TO MIDDLE 20 PERCENT RANGE.
06.12Z NCEP NAM/GFS AS WELL AS A FEW OF THE HI-RES WRF MODELS
SHOWING GOOD AGREEMENT WITH TIMING OF COLD FRONTAL PASSAGE SATURDAY.
NAM/GFS AS WELL AS THE ECMWF/GEM STAY IN GOOD AGREEMENT THROUGH THE
REMAINDER OF THE SHORT TERM.
FOR TONIGHT...WILL SEE THE HIGH MOVE INTO THE GREAT LAKES REGION AS
A COLD FRONT MOVES EAST FROM THE NORTHERN PLAINS INTO WESTERN MN/IA
BY DAYBREAK. FAIRLY QUIET WEATHER WILL RESULT OVER OUR AREA BETWEEN
THESE TWO SYSTEMS WITH ANY RAIN REMAINING WELL WEST ALONG THE COLD
FRONT. ONLY SENSIBLE WEATHER WILL BE INCREASING CLOUDS WEST OF THE
MISSISSIPPI AFTER MIDNIGHT. OTHERWISE...LOOK FOR TEMPERATURES TO
FALL INTO THE MIDDLE 30S TO A FEW LOWER 40S WITH SOUTHEAST WINDS IN
THE 5 TO 10 MPH RANGE.
MODELS STILL SHOW DIMINISHING 925-850MB MOISTURE TRANSPORT AHEAD OF
THE COLD FRONT AS IT MAKES ITS WAY THROUGH THE AREA ON
SATURDAY...ALONG WITH BETTER 500-300MB PV ADVECTION REMAINING NORTH
OF US. BASED ON THIS SIGNAL...STILL THINKING THAT THERE WILL BE A
SCATTERED TO BROKEN LINE OF SHOWERS ALONG THIS FRONT WITH RAINFALL
OF A FEW HUNDRETHS OF AN INCH. BASED ON THESE SIGNALS...WENT WITH
GENERAL 40-50 POPS THROUGH THE DAY WITH 60/LIKELY POPS ACROSS TAYLOR
AND CLARK COUNTIES CLOSER TO THE BETTER PV-ADVECTION. APPEARS THE
FRONT AND RAIN SHOWERS WILL BE CLEAR OF THE AREA BY LATER IN THE
EVENING. CAPE IS MINIMAL WITH THIS FRONTAL PASSAGE...SO CONTINUED
THE THUNDERLESS FORECAST AS WELL.
FOCUS THEN TURNS TO SUNDAY. MODELS SHOW THE DEEP LOW MOVING TOWARD
HUDSON BAY CANADA WHILE A SECONDARY MID-LEVEL SHORTWAVE TROUGH DROPS
THROUGH NORTHERN MN/WI. NAM/GFS SHOW A FEW INTERESTING THINGS
HAPPENING WITH THIS SCENARIO: FIRST IS A NOSE OF 925MB WARM AIR
ADVECTION ACROSS NORTHERN IA INTO SOUTHERN WI WITH TEMPERATURES IN
THE 9-13C RANGE. SECONDLY...DEEP MIXING INDICATED BY BUFKIT DATA
WITH MIXING ALMOST 700MB. THIS WILL RESULT IN MIXING DRIER/HIGHER
WINDS FROM ALOFT TO THE SURFACE. BASED ON THIS SIGNAL...HAVE
INCREASED TEMPERATURES A BIT ACROSS SOUTHERN HALF OF THE FORECAST
AREA AND INCREASED WIND GUSTS LATER IN THE MORNING THROUGH THE
AFTERNOON. ALSO LOWERED DEW POINTS SOME WITH THE DRIER AIR MIXING
DOWN. THIS HAS CAUSED AN INCREASE CONCERN IN THE AREA OF FIRE
WEATHER. HAVE THEREFORE INCLUDED A SPECIAL FIRE WEATHER DISCUSSION
BELOW. OTHERWISE...LOOK FOR HIGHS RANGING FROM THE MID-UPPER 50S
NORTH OF I-94 TO THE LOWER MIDDLE 60S ACROSS THE REST OF THE
FORECAST AREA. WINDS ARE EXPECTED TO BE IN THE 15 TO 20 MPH RANGE
WITH GUSTS IN THE 30 TO 35 MPH RANGE.
SECONDARY PUSH OF COLD AIR ADVECTION COMES THROUGH SUNDAY NIGHT
THROUGH MONDAY WITH CANADIAN HIGH PRESSURE OOZING INTO THE REGION. A
FAIRLY TIGHT PRESSURE GRADIENT IS ALSO EXPECTED FOR BRISK NORTHWEST
WINDS WHICH WILL ADD A CHILL TO THE AIR AS HIGHS TOP OFF ONLY IN THE
UPPER 40S TO LOWER 50S.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
230 PM CDT FRI APR 6 2012
06.12Z GFS/ECMWF IN GOOD AGREEMENT WITH COOLER NORTHWEST FLOW OVER
THE AREA THROUGH WEDNESDAY...BUT THEN ARE AT ODDS IN HANDLING OF
UPPER LEVEL PATTERN AND BOTTOM LINE PRECIPITATION CHANCES THURSDAY
THROUGH FRIDAY. THE GFS //WHICH IS SHOWING A BIT MORE RUN-RUN
CONSISTENCY// TAKES A LOW PRESSURE SYSTEM OUT OF THE INTERMOUNTAIN
WEST AND MOVES IT INTO THE NORTHERN PLAINS BY FRIDAY. MOISTURE
TRANSPORT/ISENTROPIC LIFT AHEAD OF THE LOW BRINGS RAIN INTO THE
AREA. THE ECMWF ON THE OTHER HAND WANTS TO DIG THE MID-LEVEL TROUGH
AND SURFACE LOW FARTHER TO THE SOUTH...KEEPING US HIGH AND DRY. WILL
GO FOR A MODEL CONSENSUS APPROACH FOR NOW WHICH SPREADS SMALL 20-30
PERCENT RAIN CHANCES ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
THURSDAY THROUGH FRIDAY. OTHERWISE...TEMPERATURES WILL START OFF
CHILLY WITH HIGHS TUESDAY IN THE 40S...SLOWLY WARMING INTO THE 50S
BY THURSDAY/FRIDAY. WILL ALSO HAVE TO KEEP A CLOSE EYE ON POSSIBLE
FREEZE HEADLINES MONDAY/TUESDAY/WEDNESDAY NIGHTS WITH LOWS IN THE
UPPER 20S/LOWER 30S.
&&
.AVIATION...
555 PM CDT FRI APR 6 2012
A COLD FRONT WILL SLIDE WEST TO EAST ACROSS THE REGION ON
SATURDAY...LIKELY MOVING ACROSS KRST NEAR 21Z AND KLSE NEAR 00Z SAT.
MODELS POINT TO A NARROW BAND OF DEEPER SATURATION ALONG THE
BOUNDARY...WHICH COULD RESULT IN SOME MVFR CIGS. WILL KEEP ABOVE FOR
NOW. IN ADDITION...A BROKEN LINE OF -SHRA APPEARS LIKELY...AND WILL
ADD MENTION TO TAFS. LITTLE IF ANY INSTABILITY TO TAP INTO...SO
DON/T EXPECT ANY THUNDER.
WINDS WILL BE ON THE INCREASE AHEAD OF THE FRONT...WITH MIXING
PROMOTING SOME GUSTS AHEAD...AND ESPECIALLY POST THE FRONT.
&&
.FIRE WEATHER...SUNDAY
230 PM CDT FRI APR 6 2012
BREEZY WEST WINDS IN THE 15 TO 20 MPH RANGE WITH GUSTS OF 30-35 MPH
COMBINED WITH LOW RELATIVE HUMIDITY VALUES IN THE 20-25 PERCENT
RANGE WILL PRODUCE AN ELEVATED FIRE WEATHER CONCERN SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 PM CDT FRI APR 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....DAS
LONG TERM......DAS
AVIATION.......RIECK
FIRE WEATHER...DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
247 PM CDT FRI APR 6 2012
.SHORT TERM...TONIGHT AND SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SPRAWLING
HIGH PRESSURE SYSTEM STRETCHING FROM HUDSON BAY TO THE SOUTH-CENTRAL
GREAT LAKES THIS AFTERNOON. VERY QUIET DAY SO FAR WITH TEMPS
RANGING FROM THE MIDDLE 40S LAKESIDE TO THE MIDDLE 50S OVER CENTRAL
WISCONSIN. LOOKING UPSTREAM...STRONG TROUGH MOVING OVER THE CENTRAL
ROCKIES IS CREATING A TROUGH OF LOW PRESSURE OVER THE WESTERN
DAKOTAS. VERY FEW PRECIP REPORTS WITHIN THE MOISTURE CHANNEL AHEAD
OF THIS TROUGH...THOUGH THERE WERE A FEW LIGHTNING STRIKES EARLIER.
WITH A DRY CANADIAN AIRMASS IN PLACE...FIRST CONCERNS REVOLVE AROUND
FREEZE HEADLINES...THEN PRECIP CHANCES TOMORROW AS THE FRONT MOVES
INTO THE REGION.
TONIGHT...SURFACE HIGH PRESSURE WILL SLIDE SOUTHEAST TONIGHT TO
INDIANA AND OHIO BY 12Z SATURDAY...IN RESPONSE TO HEIGHT FALLS
OCCURRING OVER THE NORTHERN PLAINS. RIDGING THROUGH THE COLUMN AND
A VERY DRY AIRMASS SUPPORTS CONTINUING GOING CLEAR TONIGHT THOUGH
LOWS WILL NOT BE NEARLY AS COLD...THANKS TO WARMER AFTERNOON HIGHS AND
TIGHTER PRESSURE GRADIENT PUSHING IN FROM THE WEST LATE. BUT
GUIDANCE STILL SUPPORTS TEMPS FALLING AT OR BELOW 28 DEGREES FROM
EASTERN VILAS/ONEIDA TO NORTHERN MARINETTE COUNTIES. WILL ISSUE A
FREEZE WARNING FOR THE NORTHERN TIER OF COUNTIES. LOWS RANGING FROM
THE MID 20S NORTH TO MID 30S SOUTH.
SATURDAY...STRONG SHORTWAVE TROUGH WILL SWING NE OVER THE NORTHERN
PLAINS AND THE NORTHERN MISSISSIPPI VALLEY...AND DRIVE A COLD FRONT
INTO CENTRAL WISCONSIN IN THE AFTERNOON. SKIES WILL START OUT CLEAR
TO BEGIN THE DAY...BUT WILL SEE INCREASING CLOUDS FROM WEST TO EAST
STARTING ROUGHLY LATE IN THE MORNING AND THEN THROUGH THE
AFTERNOON. ALTHOUGH THE SHORTWAVE LOOKS RATHER BEEFY...CONVERGENCE
ALONG THE FRONT DOES NOT. INSTABILITY IS NOT THERE EITHER...AND
MODIFYING NAM SOUNDINGS ONLY SHOWS AROUND 12 J/KG OF ELEVATED CAPE
DUE TO A WARM LAYER CENTERED APPROX AT AROUND 650MB. WITH
SATURATION ONLY OCCURRING WITHIN ABOUT A 150MB LAYER BETWEEN 850 AND
700MB...THINK WILL SEE A SOMEWHAT NARROW BAND OF SCT TO BKN SHOWER
COVERAGE. WILL ONLY HAVE A FEW HUNDREDTHS OF INCH OF QPF...SO NOT
EXPECTING A BIG WASH OUT TO RUIN OUTDOOR PLANS. TEMPS WILL COOL
BEHIND THE FRONT ONCE THE SHOWERS AND CLOUD COVER ARRIVE. HIGHS
WILL REACH FROM AROUND 60 WEST TO THE MIDDLE 60S EAST.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...PCPN TRENDS SATURDAY
NIGHT AND POTENTIAL FIRE WEATHER CONCERNS ON EASTER SUNDAY.
A COLD FRONT AND SHARP UPPER TROF WILL BRING A LINE OF SHOWERS THROUGH
THE FORECAST AREA SATURDAY EVENING. HAVE KEPT LIKELY POPS (HIGH POP/LOW
QPF EVENT) FOR THE EVENING...BUT REMOVED ALL PCPN AFTER MIDNIGHT.
ON SUNDAY...FCST SOUNDINGS SHOW VERY DEEP MIXING (750-700 MB)...WHICH
WILL SUPPORT WARMER...DRIER AND WINDIER CONDITIONS THAN PREVIOUSLY
THOUGHT. HAVE BOOSTED TEMPS INTO THE UPPER 50S AND LOWER 60S...DROPPED
RELATIVE HUMIDITY INTO THE 15-25 PERCENT RANGE...AND BOOSTED WIND GUSTS
TO 30 TO 35 MPH AT MOST LOCATIONS. THESE CONDITIONS...COMBINED WITH
THE RECENT DRY CONDITIONS...MAY LEAD TO CRITICAL FIRE WEATHER CONDITIONS
ON EASTER SUNDAY.
A SECONDARY COLD FRONT WILL MOVE THROUGH THE FA ON SUNDAY NIGHT...WHICH
WILL RESULT IN TEMPERATURES CLOSER TO NORMAL ON MONDAY. GUSTY NORTHWEST
WINDS ARE EXPECTED ON MONDAY AND TUESDAY AFTERNOON.
A STRONG SURFACE RIDGE IS EXPECTED TO BUILD INTO THE AREA BY THE MIDDLE
OF THE NEXT WORK WEEK. THIS WILL BRING MORE DRY AND SEASONAL WEATHER
TO THE REGION. THERE IS SOME DISAGREEMENT WITH HOW QUICKLY THE HIGH
WILL RETREAT LATE IN THE WEEK...WITH THE ECMWF HOLDING THE HIGH OVER
THE WSTRN GREAT LAKES...WHILE THE GFS SLIDES IT SLOWLY TO OUR EAST.
&&
.AVIATION...VFR CONDITIONS THROUGH THE TAF PERIOD. A COLD FRONT
WILL APPROACH CENTRAL WISCONSIN BY MID-AFTERNOON. ANTICIPATE FEW TO
SCT SHOWER ACTIVITY RIGHT BEHIND THE FRONT...AND CIGS LOWERING FROM
AROUND 5500 FT DOWN TO MVFR LEVELS BY LATE AFTERNOON.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 2 AM TO 8 AM CDT SATURDAY FOR WIZ005-010>013.
&&
$$
MPC/KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
230 PM CDT FRI APR 6 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
230 PM CDT FRI APR 6 2012
FORECAST CONCERNS INCLUDE RAIN CHANCES SATURDAY...DRY AND BREEZY
CONDITIONS SUNDAY.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGHLY AMPLIFIED RIDGE
OF HIGH PRESSURE EXTENDING FROM MEXICO THROUGH THE MIDWEST/UPPER
MISSISSIPPI RIVER REGION...INTO WESTERN ONTARIO CANADA. AT THE
SURFACE...HIGH PRESSURE DOMINATED THE CENTRAL CONUS WITH THE CENTER
OF THE HIGH LOCATED OVER EASTERN ONTARIO CANADA. EAST/SOUTHEAST COOL
AND DRY OUTFLOW FROM THE HIGH KEEPING TEMPERATURES IN THE 50S WITH
RELATIVE HUMIDITY LEVELS IN THE LOWER TO MIDDLE 20 PERCENT RANGE.
06.12Z NCEP NAM/GFS AS WELL AS A FEW OF THE HI-RES WRF MODELS
SHOWING GOOD AGREEMENT WITH TIMING OF COLD FRONTAL PASSAGE SATURDAY.
NAM/GFS AS WELL AS THE ECMWF/GEM STAY IN GOOD AGREEMENT THROUGH THE
REMAINDER OF THE SHORT TERM.
FOR TONIGHT...WILL SEE THE HIGH MOVE INTO THE GREAT LAKES REGION AS
A COLD FRONT MOVES EAST FROM THE NORTHERN PLAINS INTO WESTERN MN/IA
BY DAYBREAK. FAIRLY QUIET WEATHER WILL RESULT OVER OUR AREA BETWEEN
THESE TWO SYSTEMS WITH ANY RAIN REMAINING WELL WEST ALONG THE COLD
FRONT. ONLY SENSIBLE WEATHER WILL BE INCREASING CLOUDS WEST OF THE
MISSISSIPPI AFTER MIDNIGHT. OTHERWISE...LOOK FOR TEMPERATURES TO
FALL INTO THE MIDDLE 30S TO A FEW LOWER 40S WITH SOUTHEAST WINDS IN
THE 5 TO 10 MPH RANGE.
MODELS STILL SHOW DIMINISHING 925-850MB MOISTURE TRANSPORT AHEAD OF
THE COLD FRONT AS IT MAKES ITS WAY THROUGH THE AREA ON
SATURDAY...ALONG WITH BETTER 500-300MB PV ADVECTION REMAINING NORTH
OF US. BASED ON THIS SIGNAL...STILL THINKING THAT THERE WILL BE A
SCATTERED TO BROKEN LINE OF SHOWERS ALONG THIS FRONT WITH RAINFALL
OF A FEW HUNDRETHS OF AN INCH. BASED ON THESE SIGNALS...WENT WITH
GENERAL 40-50 POPS THROUGH THE DAY WITH 60/LIKELY POPS ACROSS TAYLOR
AND CLARK COUNTIES CLOSER TO THE BETTER PV-ADVECTION. APPEARS THE
FRONT AND RAIN SHOWERS WILL BE CLEAR OF THE AREA BY LATER IN THE
EVENING. CAPE IS MINIMAL WITH THIS FRONTAL PASSAGE...SO CONTINUED
THE THUNDERLESS FORECAST AS WELL.
FOCUS THEN TURNS TO SUNDAY. MODELS SHOW THE DEEP LOW MOVING TOWARD
HUDSON BAY CANADA WHILE A SECONDARY MID-LEVEL SHORTWAVE TROUGH DROPS
THROUGH NORTHERN MN/WI. NAM/GFS SHOW A FEW INTERESTING THINGS
HAPPENING WITH THIS SCENARIO: FIRST IS A NOSE OF 925MB WARM AIR
ADVECTION ACROSS NORTHERN IA INTO SOUTHERN WI WITH TEMPERATURES IN
THE 9-13C RANGE. SECONDLY...DEEP MIXING INDICATED BY BUFKIT DATA
WITH MIXING ALMOST 700MB. THIS WILL RESULT IN MIXING DRIER/HIGHER
WINDS FROM ALOFT TO THE SURFACE. BASED ON THIS SIGNAL...HAVE
INCREASED TEMPERATURES A BIT ACROSS SOUTHERN HALF OF THE FORECAST
AREA AND INCREASED WIND GUSTS LATER IN THE MORNING THROUGH THE
AFTERNOON. ALSO LOWERED DEW POINTS SOME WITH THE DRIER AIR MIXING
DOWN. THIS HAS CAUSED AN INCREASE CONCERN IN THE AREA OF FIRE
WEATHER. HAVE THEREFORE INCLUDED A SPECIAL FIRE WEATHER DISCUSSION
BELOW. OTHERWISE...LOOK FOR HIGHS RANGING FROM THE MID-UPPER 50S
NORTH OF I-94 TO THE LOWER MIDDLE 60S ACROSS THE REST OF THE
FORECAST AREA. WINDS ARE EXPECTED TO BE IN THE 15 TO 20 MPH RANGE
WITH GUSTS IN THE 30 TO 35 MPH RANGE.
SECONDARY PUSH OF COLD AIR ADVECTION COMES THROUGH SUNDAY NIGHT
THROUGH MONDAY WITH CANADIAN HIGH PRESSURE OOZING INTO THE REGION. A
FAIRLY TIGHT PRESSURE GRADIENT IS ALSO EXPECTED FOR BRISK NORTHWEST
WINDS WHICH WILL ADD A CHILL TO THE AIR AS HIGHS TOP OFF ONLY IN THE
UPPER 40S TO LOWER 50S.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
230 PM CDT FRI APR 6 2012
06.12Z GFS/ECMWF IN GOOD AGREEMENT WITH COOLER NORTHWEST FLOW OVER
THE AREA THROUGH WEDNESDAY...BUT THEN ARE AT ODDS IN HANDLING OF
UPPER LEVEL PATTERN AND BOTTOM LINE PRECIPITATION CHANCES THURSDAY
THROUGH FRIDAY. THE GFS //WHICH IS SHOWING A BIT MORE RUN-RUN
CONSISTENCY// TAKES A LOW PRESSURE SYSTEM OUT OF THE INTERMOUNTAIN
WEST AND MOVES IT INTO THE NORTHERN PLAINS BY FRIDAY. MOISTURE
TRANSPORT/ISENTROPIC LIFT AHEAD OF THE LOW BRINGS RAIN INTO THE
AREA. THE ECMWF ON THE OTHER HAND WANTS TO DIG THE MID-LEVEL TROUGH
AND SURFACE LOW FARTHER TO THE SOUTH...KEEPING US HIGH AND DRY. WILL
GO FOR A MODEL CONSENSUS APPROACH FOR NOW WHICH SPREADS SMALL 20-30 PERCENT
RAIN CHANCES ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST THURSDAY
THROUGH FRIDAY. OTHERWISE...TEMPERATURES WILL START OFF CHILLY WITH
HIGHS TUESDAY IN THE 40S...SLOWLY WARMING INTO THE 50S BY
THURSDAY/FRIDAY. WILL ALSO HAVE TO KEEP A CLOSE EYE ON POSSIBLE
FREEZE HEADLINES MONDAY/TUESDAY/WEDNESDAY NIGHTS WITH LOWS IN THE
UPPER 20S/LOWER 30S.
&&
.AVIATION...THROUGH 18Z SATURDAY
1225 PM CDT FRI APR 6 2012
QUIET CONDITIONS TO START OUT THE TAF PERIOD WITH CLEAR SKIES AND
LIGHT WINDS GOING INTO TONIGHT. THE MAIN WEATHER CONCERN COMES IN
TOMORROW MORNING AS A COLD FRONT MOVES INTO THE REGION. LOW LEVEL
MOISTURE WILL BE ON THE INCREASE WITH LOW TO MID LEVEL CLOUDS ON
THE INCREASE AS A RESULT. FORECAST SOUNDINGS AT RST AND LSE SHOW A
MOISTENING UP OF THE 5KFT TO 8KFT LAYER IN THE MORNING WITH SOME
POSSIBLE MVFR CEILINGS GETTING INTO RST LATE IN THE MORNING. SOME
SHOWERS WILL BE POSSIBLE AHEAD OF THE FRONT WITH THE TIMING OF
THEM GETTING INTO RST AROUND 16Z AND LSE AT 18Z. NOT MUCH...IF
ANY...INSTABILITY IS PRESENT SO AM NOT EXPECTING ANY THUNDER AT THIS
POINT.
&&
.FIRE WEATHER...SUNDAY
230 PM CDT FRI APR 6 2012
BREEZY WEST WINDS IN THE 15 TO 20 MPH RANGE WITH GUSTS OF 30-35 MPH
COMBINED WITH LOW RELATIVE HUMIDITY VALUES IN THE 20-25 PERCENT
RANGE WILL PRODUCE AN ELEVATED FIRE WEATHER CONCERN SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
230 PM CDT FRI APR 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION.......HALBACH
FIRE WEATHER...DAS