Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 02/27/12
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
407 PM EST SAT FEB 25 2012
.SYNOPSIS...
AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY
AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST
SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY
WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY
NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH
ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND
FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW
JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN
THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG
THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN
HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER
LOW PRESSURE SYSTEM ARRIVES TO START THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A 19Z SURFACE ANALYSIS PLACED AN INTENSE LOW ACROSS THE CANADIAN
MARITIMES. THE LOWEST SURFACE PRESSURE SO FAR WITH THIS WAS 966 MB.
A TROUGH OR SECONDARY FRONT IS DRAPED ACROSS NEW YORK STATE TO LAKE
MICHIGAN. HIGH PRESSURE WAS ACROSS THE MISSISSIPPI VALLEY. AN UPPER
AIR ANALYSIS INDICATED A SHARP TROUGH AXIS FROM NEW ENGLAND TO THE
UPPER OHIO VALLEY. A RIDGE WAS IN THE PLAINS WITH ANOTHER TROUGH IN
THE NORTHERN ROCKIES. AN AREA OF FOCUSED WAA AT 850 MB WAS ACROSS
THE CENTRAL AND NORTHERN PLAINS. A STRONG CYCLONICALLY CURVED 250 MB
JET WAS FROM THE MIDWEST TO THE OHIO VALLEY THEN OFF THE NEW ENGLAND
COAST.
AS THE INTENSE STORM IN THE CANADIAN MARITIMES CONTINUES TO MOVE
NORTHEASTWARD, HIGH PRESSURE WILL BEGIN TO EDGE CLOSER FROM THE WEST
THROUGH TONIGHT. THE UPPER-LEVEL TROUGH AXIS HOWEVER IS FORECAST TO
SWING ACROSS OUR AREA EARLY THIS EVENING. THE COMBINATION OF DEEP
CYCLONIC FLOW, CAA AND STEEP LOW-LEVEL LAPSE RATES HAVE ALLOWED SNOW
SHOWERS TO OCCUR MAINLY ACROSS THE NORTHERN HALF OF THE CWA. THESE
ARE MORE CONVECTIVE, AND ANY STRONGER ACTIVITY COULD PRODUCE A BURST
OF SNOW. ANY LOCAL SNOW ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR
LESS AS IT APPEARS THE SNOW SHOWERS WILL BE TRANSIENT. SOME OF THE
HIGH RESOLUTION MODELS HOWEVER, SUCH AS THE HRRR AND THE SPC
WRF-NMM, INDICATE THAT THERE COULD BE A COUPLE OF WEST TO EAST
ORIENTATED SNOW BANDS MOVING THROUGH PARTS OF THE AREA THROUGH EARLY
THIS EVENING. THIS WAS OBSERVED THIS MORNING, AND GIVEN THE TROUGH
AXIS MOVING THROUGH IT CANNOT BE RULED OUT.
THERE ARE TWO DISTINCT BANDS ON THE RADAR AS OF 20Z, ONE ACROSS
CENTRAL PENNSYLVANIA AND THE OTHER ONE DROPPING SOUTHEASTWARD INTO
NORTHEASTERN PENNSYLVANIA. THE LATTER LOOKS TO BE AHEAD OF A WEAK
SURFACE TROUGH OR FRONT WITH SOME VEERING OF THE WINDS A BIT MORE TO
THE NORTHWEST BEHIND IT. THE 12Z SPC WRF-NMM HAS PICKED UP ON THIS
ACTIVITY AND IS DOING WELL AS OF 19Z. IT BRINGS THESE TWO BANDS
ACROSS PORTIONS OF EASTERN PENNSYLVANIA AND THE NORTHERN HALF OF NEW
JERSEY THROUGH ABOUT 23Z BEFORE WEAKENING THEM. WE LEANED OUR POPS
CLOSER TO THIS, WITH SOME LIKELY VALUES ACROSS THE FAR NORTHWEST
INTO THIS EVENING, AND SOME HIGHER CHC VALUES FARTHER SOUTH. IF
THESE BANDS OCCUR, A BURST OF HEAVIER SNOW WILL FALL WHICH WILL
GREATLY REDUCE THE VISIBILITY FOR A SHORT TIME. AS WE TAPERED THE
POPS DOWN WITH A SOUTHEASTWARD EXTENT, DID CARRY SCATTERED FLURRIES
ON THE SOUTHERN END FOR NOW WITH MOST OF THIS MENTION ALONG AND
NORTH/WEST OF INTERSTATE 95. ANY ACTIVITY SHOULD WEAKEN AND THEN
DISSIPATE DURING THE NIGHT AS SOME DRIER AIR AND SUBSIDENCE BEGINS
TO WORK INTO THE AREA. THIS WILL ALSO ALLOW THE STRATOCUMULUS TO
RETREAT NORTHWESTWARD THROUGH THE NIGHT.
THE STRONG WINDS ACROSS THE AREA WILL CONTINUE INTO THIS EVENING AS
THE 925 MB WINDS ARE FORECAST TO INCREASE SOME AS THE TROUGH AXIS
SWINGS THROUGH. WE SHOULD START TO SHRINK THE VERTICAL MIXING EARLY
THIS EVENING AS THE LOSS OF DAYTIME HEATING OCCURS, HOWEVER IT
APPEARS WE SHOULD ACHIEVE SOME ADVISORY LEVEL GUSTS INTO THIS
EVENING. THEREFORE, WE WILL CONTINUE THE WIND ADVISORY ACROSS THE
ENTIRE CWA UNTIL 7 PM.
AS FOR TEMPERATURES, WE GENERALLY USED A BLEND OF THE GFS/NAM MOS.
THE WINDS SHOULD DROP OFF ENOUGH LATER TONIGHT TO ALLOW THE
TEMPERATURES TO DROP MORE GIVEN THE LOW DEW POINTS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AN UPPER-LEVEL TROUGH WILL BE WELL EAST OF OUR AREA SUNDAY AS A MID
LEVEL RIDGE APPROACHES FROM THE WEST. THIS WILL DRIVE SURFACE HIGH
PRESSURE OVER OUR AREA DURING THE COURSE OF THE DAY. THERE IS A
LINGERING PRESSURE GRADIENT TO START THE MORNING, HOWEVER THIS
WEAKENS FAIRLY QUICKLY AS THE SURFACE HIGH BEGINS TO CREST INTO OUR
REGION. THIS WILL RESULT IN MUCH LESS WIND COMPARED TO TODAY.
THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE PORTIONS
OF THE ATMOSPHERE AND SUBSIDENCE TO LIMIT ANY STRATOCUMULUS
DEVELOPMENT. AN AREA OF WAA UP THROUGH THE OHIO VALLEY HOWEVER WILL
TEND TO DRIVE A DEVELOPING WARM FRONT JUST TO OUR WEST. THE MAIN
PUSH OF MILDER AIR IS FORECAST TO BE FOCUSED MORE TO OUR WEST.
HOWEVER AS THE MID LEVEL RIDGE AXIS NEARS, SOME HIGH CLOUDS MAY
START TO MOVE IN. THIS LOOKS MINIMAL AT THIS POINT, THEREFORE WE
LEANED TOWARD A GOOD DEAL OF SUNSHINE DURING THE DAY.
AS FOR TEMPERATURES, WE MAINLY WENT WITH A MOS BLEND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING
SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS
THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA.
THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE
ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND.
THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY
EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING.
THE SECOND SHORT WAVE AND STRONGER LOW PRESSURE SYSTEM IN THE
MIDWEST WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT
EVENTUALLY MOVES OFF THE NJ OR DE COAST THURSDAY.
PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS.
WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY
OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE
ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF
BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON
12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50.
THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE
PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM
SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN
NCEP GUIDANCE SOLN FOR WED-FRI.
THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE
UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT
ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER
EVENT. THERE IS MUCH LESS CHC OF THIS INSIDE RUNNER GETTING
SQUASHED SOUTH OF LONG ISLAND BUT WITH RELATIVELY COLD TEMPS TO
START...AT LEAST A LITTLE ICE OR SNOW IS ENVISIONED FRI NIGHT.
TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. 12Z/25 NCEP
MODEL GUIDANCE APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF
PCPN IS OCCURRING ON WED-THU. USED HPC GUIDANCE TEMPS/WINDS.
THE DAILIES...
SUNDAY NIGHT AND MONDAY...FAIR WITH A DRY SW FLOW WAA BEHIND THE
DEPARTING MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING
START TO MONDAY MORNING WARMS QUICKLY TO WELL ABOVE NORMAL TEMPS
IN THE AFTN WITH GUSTY SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE.
WILL THIS BE A FWX CONCERN FOR AN SPS AFTN? PROBABLY NOT BECAUSE
OF YDYS RAINFALL AND CHILLY TEMPS OF THIS WEEKEND.
MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE.
TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES
OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN
ZONES.
TUESDAY NIGHT-WEDNESDAY...COMPLEX. A MODEL BATTLE BETWEEN GEFS
AND THE UKMET-GGEM-ECMWF.
A WARM FRONT WILL PRODUCE PRECIPITATION WEDNESDAY..SOME OF IT
EXPECTED TO BE SNOW FROM KABE- KSMQ REGION NORTH AND WHEN ALL IS
SAID AND DONE THURSDAY...THIS SEASONABLE WINTER WX EVENT MAY BE
RIVALING ONE OF THE MORE SIGNIFICANT SNOW EVENTS OF THIS EASY
GOING WINTER.
THE SOUTHERN EDGE OF WINTER WX IS NOT SET IN STONE BUT WAS THE BEST
ESTIMATE I COULD OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND
REALIZING WE ARE STILL IN MET WINTER.
12Z/25 HPC GUIDANCE TEMPS/WINDS. PTYPE WAS RUN OFF A BLEND OF 12Z
ECMWF/GFS PARTIAL THICKNESSES AND BLV ITS BIAS`D TOO WARM AND TOO
WET.
LOW PROB OF THUNDER DE/MD IN THE MORNING ON THE NOSE OF THE LLJ.
WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS
NO WHERE TO GO BUT EAST OR ESE...FORCED BY THE CONFLUENCE ZONE IN
MAINE. THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF
LEFTOVER DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR
FA...THEN VERY LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS
EWD FROM NJ OR DE AS PER THE ECMWF FOR WED NIGHT...IT WILL HAVE THE
BAROCLINIC ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE
THURSDAY MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND
NW NJ AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ-
KABE. THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO
PHIL.
12Z/25 HPC GUIDANCE TEMPS/WINDS. THE WIND FCST IS QUESTIONABLE AND
BLV WE WILL NEED MORE NE IN THE NEXT FCST FOR NJ AND SIGNIFICANTLY
STRONGER FOR NNJ.
FRIDAY...DRY CANADIAN HIGH PRES BRIEFLY REASSERTS CONTROL HERE.
HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY
SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25
HPC GUIDANCE WAS USED AND NOT MUCH ENERGY INTO MODIFYING THE DATA.
APPEARS THAT 500MB CONFLUENCE SUPPRESSION IS MUCH LESS OF A RISK.
THERE MIGHT BE A TRIPLE PT OCCLUSION AND PRES FALLS NEAR THE PT
OF OCCLUSION HOLDING LEFTOVER COLD AIR IN LONG ENOUGH /NE SFC
WIND/ FOR ICE AT THE START OVER NE PA AND NW NJ.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK
NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD
INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS
HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY
WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF THE NIGHT.
THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS INTO EARLY THIS
EVENING, THEN THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS
THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE
WEST.
A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON
WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN
AND HIGH PRESSURE GETS A BIT CLOSER DURING THE NIGHT. ANY SNOW
SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE
EVENING, AND GENERALLY BE NORTH AND WEST FROM ABOUT KTTN TO KILG. A
NARROW BAND OF HEAVIER SNOW MAY DEVELOP ACROSS PARTS OF THE REGION
THROUGH EARLY THIS EVENING, THEREFORE SOME BRIEF BUT GREATLY
REDUCED VISIBILITIES /AND SOME LOWER CEILINGS/ MAY OCCUR. SOME
SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS
THAT LOOK TO IMPACT ANY LOCAL TERMINAL.
FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT
OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A
WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE
WEAKENING MORE BY LATER IN THE DAY. THERE APPEARS TO BE ENOUGH
DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT AND
STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED.
OUTLOOK...
SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN.
WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY
PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE
TO OCNL IFR. LOW PROB THUNDER DE/MD WED MORNING. ENE WINDS IN
COASTAL NE NJ MAY G25 KT ON THURSDAY.
&&
.MARINE...
THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE REGION DUE TO AN
INTENSE STORM IN THE CANADIAN MARITIMES AND HIGH PRESSURE MOVING
INTO THE OHIO VALLEY. THIS GRADIENT IS EXPECTED TO WEAKEN THROUGH
THE NIGHT AS HIGH PRESSURE EDGES CLOSER. THE MODEL GUIDANCE
INDICATES THAT THE 925 MB FLOW INCREASES SOME THROUGH EARLY THIS
EVENING AS THE UPPER-LEVEL TROUGH AXIS MOVES ACROSS THE AREA. THIS
SHOULD TEND TO KEEP THE LOWER LEVELS MIXED FAIRLY WELL WITH GUSTS TO
NEAR 40 KNOTS. BASED ON THE FORECAST SOUNDINGS, WE WILL CONTINUE THE
GALE WARNING FOR ALL OUR ZONES UNTIL 06Z TONIGHT. A SMALL CRAFT
ADVISORY WILL THEN BE NEEDED FOLLOWING THE GALE AS WINDS WILL GUST
TO NEAR 30 KNOTS FOR A TIME AND SEAS WILL HOLD UP ESPECIALLY ON THE
OCEAN. FOR SUNDAY, HIGH PRESSURE WILL BE BUILDING IN THEREFORE ANY
LINGERING GUSTY WINDS WILL BE ON A DIMINISHING TREND THROUGH THE
DAY. THIS WILL ALSO ALLOW THE SEAS TO SUBSIDE.
OUTLOOK...
SUNDAY NIGHT...QUIET WITH LIGHT WIND.
MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN.
MONDAY NIGHT....NW SCA GUSTS POSSIBLE.
TUESDAY...NO HEADLINE.
WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER
A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH.
WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ
WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS.
WHILE UNCERTAIN...ON THE STRENGTH OF RECENT ECWMF PERFORMANCE..
ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS 20-30 KTS AT TIMES
BY WED NIGHT OR THURSDAY MORNING.
&&
.TIDES/COASTAL FLOODING...
THE STRONG WESTERLY FLOW CONTINUES TO DRIVE THE TIDAL DEPARTURES
DOWN INTO THE NEGATIVE RANGE ESPECIALLY DURING LOW TIDE. THIS IS
EXPECTED TO CONTINUE THROUGH THIS EVENING AT LEAST WITH LEVELS
GETTING RATHER CLOSE TO BLOWOUT CRITERIA /-1.8 FEET MLLW/. FOR THIS
REASON, A LOW WATER ADVISORY REMAINS IN EFFECT ALONG OUR NEW JERSEY
AND DELAWARE COASTS UNTIL 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9
PM. WATER LEVELS WILL REMAIN RATHER LOW WELL INTO TONIGHT AND IT
REMAINS POSSIBLE THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO
SEE NEAR BLOWOUT CONDITIONS. FOR NOW THOUGH, WE WILL SEE HOW THE
DEPARTURES BEHAVE AND THEREFORE NO CHANGES WERE MADE TO THE
PREVIOUS HEADLINE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...DRAG 407
AVIATION...DRAG/GORSE 407
MARINE...DRAG/GORSE 407
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
305 PM EST SAT FEB 25 2012
.SYNOPSIS...
AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY
AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST
SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY
WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY
NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH
ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND
FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW
JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN
THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG
THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN
HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER
LOW PRESSURE SYSTEMS ARRIVES TO START THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A 19Z SURFACE ANALYSIS PLACED AN INTENSE LOW ACROSS THE CANADIAN
MARITIMES. THE LOWEST SURFACE PRESSURE SO FAR WITH THIS WAS 966 MB.
A TROUGH OR SECONDARY FRONT IS DRAPED ACROSS NEW YORK STATE TO LAKE
MICHIGAN. HIGH PRESSURE WAS ACROSS THE MISSISSIPPI VALLEY. AN UPPER
AIR ANALYSIS INDICATED A SHARP TROUGH AXIS FROM NEW ENGLAND TO THE
UPPER OHIO VALLEY. A RIDGE WAS IN THE PLAINS WITH ANOTHER TROUGH IN
THE NORTHERN ROCKIES. AN AREA OF FOCUSED WAA AT 850 MB WAS ACROSS
THE CENTRAL AND NORTHERN PLAINS. A STRONG CYCLONICALLY CURVED 250 MB
JET WAS FROM THE MIDWEST TO THE OHIO VALLEY THEN OFF THE NEW ENGLAND
COAST.
AS THE INTENSE STORM IN THE CANADIAN MARITIMES CONTINUES TO MOVE
NORTHEASTWARD, HIGH PRESSURE WILL BEGIN TO EDGE CLOSER FROM THE WEST
THROUGH TONIGHT. THE UPPER-LEVEL TROUGH AXIS HOWEVER IS FORECAST TO
SWING ACROSS OUR AREA EARLY THIS EVENING. THE COMBINATION OF DEEP
CYCLONIC FLOW, CAA AND STEEP LOW-LEVEL LAPSE RATES HAVE ALLOWED SNOW
SHOWERS TO OCCUR MAINLY ACROSS THE NORTHERN HALF OF THE CWA. THESE
ARE MORE CONVECTIVE, AND ANY STRONGER ACTIVITY COULD PRODUCE A BURST
OF SNOW. ANY LOCAL SNOW ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR
LESS AS IT APPEARS THE SNOW SHOWERS WILL BE TRANSIENT. SOME OF THE
HIGH RESOLUTION MODELS HOWEVER, SUCH AS THE HRRR AND THE SPC
WRF-NMM, INDICATE THAT THERE COULD BE A COUPLE OF WEST TO EAST
ORIENTATED SNOW BANDS MOVING THROUGH PARTS OF THE AREA THROUGH EARLY
THIS EVENING. THIS WAS OBSERVED THIS MORNING, AND GIVEN THE TROUGH
AXIS MOVING THROUGH IT CANNOT BE RULED OUT.
THERE ARE TWO DISTINCT BANDS ON THE RADAR AS OF 20Z, ONE ACROSS
CENTRAL PENNSYLVANIA AND THE OTHER ONE DROPPING SOUTHEASTWARD INTO
NORTHEASTERN PENNSYLVANIA. THE LATTER LOOKS TO BE AHEAD OF A WEAK
SURFACE TROUGH OR FRONT WITH SOME VEERING OF THE WINDS A BIT MORE TO
THE NORTHWEST BEHIND IT. THE 12Z SPC WRF-NMM HAS PICKED UP ON THIS
ACTIVITY AND IS DOING WELL AS OF 19Z. IT BRINGS THESE TWO BANDS
ACROSS PORTIONS OF EASTERN PENNSYLVANIA AND THE NORTHERN HALF OF NEW
JERSEY THROUGH ABOUT 23Z BEFORE WEAKENING THEM. WE LEANED OUR POPS
CLOSER TO THIS, WITH SOME LIKELY VALUES ACROSS THE FAR NORTHWEST
INTO THIS EVENING, AND SOME HIGHER CHC VALUES FARTHER SOUTH. IF
THESE BANDS OCCUR, A BURST OF HEAVIER SNOW WILL FALL WHICH WILL
GREATLY REDUCE THE VISIBILITY FOR A SHORT TIME. AS WE TAPERED THE
POPS DOWN WITH A SOUTHEASTWARD EXTENT, DID CARRY SCATTERED FLURRIES
ON THE SOUTHERN END FOR NOW WITH MOST OF THIS MENTION ALONG AND
NORTH/WEST OF INTERSTATE 95. ANY ACTIVITY SHOULD WEAKEN AND THEN
DISSIPATE DURING THE NIGHT AS SOME DRIER AIR AND SUBSIDENCE BEGINS
TO WORK INTO THE AREA. THIS WILL ALSO ALLOW THE STRATOCUMULUS TO
RETREAT NORTHWESTWARD THROUGH THE NIGHT.
THE STRONG WINDS ACROSS THE AREA WILL CONTINUE INTO THIS EVENING AS
THE 925 MB WINDS ARE FORECAST TO INCREASE SOME AS THE TROUGH AXIS
SWINGS THROUGH. WE SHOULD START TO SHRINK THE VERTICAL MIXING EARLY
THIS EVENING AS THE LOSS OF DAYTIME HEATING OCCURS, HOWEVER IT
APPEARS WE SHOULD ACHIEVE SOME ADVISORY LEVEL GUSTS INTO THIS
EVENING. THEREFORE, WE WILL CONTINUE THE WIND ADVISORY ACROSS THE
ENTIRE CWA UNTIL 7 PM.
AS FOR TEMPERATURES, WE GENERALLY USED A BLEND OF THE GFS/NAM MOS.
THE WINDS SHOULD DROP OFF ENOUGH LATER TONIGHT TO ALLOW THE
TEMPERATURES TO DROP MORE GIVEN THE LOW DEW POINTS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AN UPPER-LEVEL TROUGH WILL BE WELL EAST OF OUR AREA SUNDAY AS A MID
LEVEL RIDGE APPROACHES FROM THE WEST. THIS WILL DRIVE SURFACE HIGH
PRESSURE OVER OUR AREA DURING THE COURSE OF THE DAY. THERE IS A
LINGERING PRESSURE GRADIENT TO START THE MORNING, HOWEVER THIS
WEAKENS FAIRLY QUICKLY AS THE SURFACE HIGH BEGINS TO CREST INTO OUR
REGION. THIS WILL RESULT IN MUCH LESS WIND COMPARED TO TODAY.
THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE PORTIONS
OF THE ATMOSPHERE AND SUBSIDENCE TO LIMIT ANY STRATOCUMULUS
DEVELOPMENT. AN AREA OF WAA UP THROUGH THE OHIO VALLEY HOWEVER WILL
TEND TO DRIVE A DEVELOPING WARM FRONT JUST TO OUR WEST. THE MAIN
PUSH OF MILDER AIR IS FORECAST TO BE FOCUSED MORE TO OUR WEST.
HOWEVER AS THE MID LEVEL RIDGE AXIS NEARS, SOME HIGH CLOUDS MAY
START TO MOVE IN. THIS LOOKS MINIMAL AT THIS POINT, THEREFORE WE
LEANED TOWARD A GOOD DEAL OF SUNSHINE DURING THE DAY.
AS FOR TEMPERATURES, WE MAINLY WENT WITH A MOS BLEND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING
SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS
THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA.
THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE
ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND.
THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY
EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING.
THE SECOND SHORT WAVE STRONGER LOW PRESSURE SYSTEM IN THE MIDWEST
WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT EVENTUALLY
MOVES OFF THE NJ OR DE COAST THURSDAY.
PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS.
WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY
OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE
ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF
BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON
12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50.
THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE
PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM
SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN
NCEP GUIDANCE SOLN FOR WED-FRI.
THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE
UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT
ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER
EVENT.
TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. NCEP MODEL GUIDANCE
APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF PCPN IS OCCURRING
ON WED-THU. USED HPC GUIDANCE TEMPS.
THE DAILIES...
SUNDAY NIGHT AND MONDAY...FAIR IN DRY SW FLOW WAA BEHIND THE DEPARTING
MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING START TO MONDAY
MORNING WARMS QUICKLY TO ABOVE NORMAL TEMPS IN THE AFTN WITH GUSTY
SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE. WILL THIS BE A FWX CONCERN
FOR AN SPS AFTN?
MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE.
TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES
OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN
ZONES.
TUESDAY NIGHT-WEDNESDAY...COMPLEX BUT A WARM FRONT WILL PRODUCE A
PERIOD OF PRECIPITATION WEDNESDAY..SOME OF IT EXPECTED TO BE SNOW
FROM KABE-KSMQ REGION NORTH AND MAYBE RIVALING ONE OF THE MORE
SIGNIFICANT SNOW EVENTS OF THE WINTER SO FAR. THAT SOUTHERN EDGE
OF WINTER WX IS NOT SET IN STONE BUT THATS THE BEST ESTIMATE I
CAN OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND REALIZING WE
ARE STILL IN MET WINTER. 12Z/25 HPC GUIDANCE TEMPS/WINDS.
WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS
NO WHERE TO GO BUT E OR ESE FORCED BY THE CONFLUENCE ZONE IN MAINE.
THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF LEFTOVER
DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR FA...THEN VERY
LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS EWD FROM NJ OR
DE AS PER THE ECMWF ON WED NIGHT...IT WILL HAVE THE BAROCLINIC
ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE THURSDAY
MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND NW NJ
AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ- KABE.
THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO PHIL.
12Z/25 HPC GUIDANCE TEMPS/WINDS.
FRIDAY...DRY CANADIAN HIGH PRES REASSERTS CONTROL HERE...BRIEFLY.
HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY
SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25 HPC
GUIDANCE AND NOT MUCH ENERGY INTO MODIFYING DATA FOR THIS DATE.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK
NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD
INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS
HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY
WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF THE NIGHT.
THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS INTO EARLY THIS
EVENING, THEN THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS
THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE
WEST.
A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON
WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN
AND HIGH PRESSURE GETS A BIT CLOSER DURING THE NIGHT. ANY SNOW
SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE
EVENING, AND GENERALLY BE NORTH AND WEST FROM ABOUT KTTN TO KILG. A
NARROW BAND OF HEAVIER SNOW MAY DEVELOP ACROSS PARTS OF THE REGION
THROUGH EARLY THIS EVENING, THEREFORE SOME BRIEF BUT GREATLY
REDUCED VISIBILITIES /AND SOME LOWER CEILINGS/ MAY OCCUR. SOME
SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS
THAT LOOK TO IMPACT ANY LOCAL TERMINAL.
FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT
OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A
WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE
WEAKENING MORE BY LATER IN THE DAY. THERE APPEARS TO BE ENOUGH
DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT AND
STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED.
OUTLOOK...
SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN.
WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY
PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE
TO OCNL IFR.
&&
.MARINE...
THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE REGION DUE TO AN
INTENSE STORM IN THE CANADIAN MARITIMES AND HIGH PRESSURE MOVING
INTO THE OHIO VALLEY. THIS GRADIENT IS EXPECTED TO WEAKEN THROUGH
THE NIGHT AS HIGH PRESSURE EDGES CLOSER. THE MODEL GUIDANCE
INDICATES THAT THE 925 MB FLOW INCREASES SOME THROUGH EARLY THIS
EVENING AS THE UPPER-LEVEL TROUGH AXIS MOVES ACROSS THE AREA. THIS
SHOULD TEND TO KEEP THE LOWER LEVELS MIXED FAIRLY WELL WITH GUSTS TO
NEAR 40 KNOTS. BASED ON THE FORECAST SOUNDINGS, WE WILL CONTINUE THE
GALE WARNING FOR ALL OUR ZONES UNTIL 06Z TONIGHT. A SMALL CRAFT
ADVISORY WILL THEN BE NEEDED FOLLOWING THE GALE AS WINDS WILL GUST
TO NEAR 30 KNOTS FOR A TIME AND SEAS WILL HOLD UP ESPECIALLY ON THE
OCEAN. FOR SUNDAY, HIGH PRESSURE WILL BE BUILDING IN THEREFORE ANY
LINGERING GUSTY WINDS WILL BE ON A DIMINISHING TREND THROUGH THE
DAY. THIS WILL ALSO ALLOW THE SEAS TO SUBSIDE.
OUTLOOK...
SUNDAY NIGHT...QUIET WITH LIGHT WIND.
MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN.
MONDAY NIGHT....NW SCA GUSTS POSSIBLE.
TUESDAY...NO HEADLINE.
WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER
A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH.
WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ
WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS.
UNCERTAINTY BUT ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS
20-30 KTS AT TIMES BY WED NIGHT AND THU.
&&
.TIDES/COASTAL FLOODING...
THE STRONG WESTERLY FLOW CONTINUES TO DRIVE THE TIDAL DEPARTURES
DOWN INTO THE NEGATIVE RANGE ESPECIALLY DURING LOW TIDE. THIS IS
EXPECTED TO CONTINUE THROUGH THIS EVENING AT LEAST WITH LEVELS
GETTING RATHER CLOSE TO BLOWOUT CRITERIA /-1.8 FEET MLLW/. FOR THIS
REASON, A LOW WATER ADVISORY REMAINS IN EFFECT ALONG OUR NEW JERSEY
AND DELAWARE COASTS UNTIL 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9
PM. WATER LEVELS WILL REMAIN RATHER LOW WELL INTO TONIGHT AND IT
REMAINS POSSIBLE THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO
SEE NEAR BLOWOUT CONDITIONS. FOR NOW THOUGH, WE WILL SEE HOW THE
DEPARTURES BEHAVE AND THEREFORE NO CHANGES WERE MADE TO THE
PREVIOUS HEADLINE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
TIDES/COASTAL FLOODING...RPW/GORSE/ROBERTSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
214 PM EST SAT FEB 25 2012
.SYNOPSIS...
AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY
AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST
SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY
WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY
NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH
ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND
FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW
JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN
THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG
THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN
HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER
LOW PRESSURE SYSTEMS ARRIVES TO START THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLIER NARROW BUT BRIEFLY INTENSE SNOW BAND HAS WEAKENED AS
IT MOVED INTO PORTIONS OF SOUTHERN NEW JERSEY EARLIER. THIS
PRODUCED LOCALLY UP TO 1.5 INCHES OF SNOW IN A SHORT PERIOD OF
TIME IN PORTIONS OF SOUTHEASTERN PENNSYLVANIA. THE COMBINATION OF
STEEPENING LOW-LEVEL LAPSE RATES, CAA AND A DEEP CYCLONIC FLOW IS
ALLOWING ADDITIONAL SNOW SHOWERS TO DEVELOP. THESE TO MAY DEVELOP
INTO EAST TO WEST TYPE BANDS. BASED ON THE SOUNDINGS AND OBSERVING
VISIBLE SATELLITE IMAGERY, THE ACTIVITY DOES HAVE A CONVECTIVE
LOOK. THEREFORE, SOME LOCAL BUT BRIEF BURSTS OF SNOW ARE POSSIBLE
THROUGH THE AFTERNOON. THE CLOUDS HAVE EVEN CLEARED OUT BEHIND
SOME OF THE HEAVIER SNOW SHOWERS AS THE AIRMASS STABILIZES FOR A
TIME. WE WILL MAINLY CARRY CHC POPS ACROSS MOSTLY THE NORTHERN
HALF OF THE CWA TO ACCOUNT FOR THIS ACTIVITY. THE HRRR APPEARS TO
BE THE ONLY HIGH RESOLUTION GUIDANCE THAT HAS CAPTURED THE SNOW
BANDS DECENTLY SO FAR.
BASED ON THE FORECAST SOUNDINGS, THE STRONGER WINDS MAY ACTUALLY
OCCUR LATER THIS AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET
EVEN DEEPER MIXING ALONG WITH SOME STRONGER WINDS ALOFT. THE WINDS
HAVE BEEN SHOWING SIGNS OF INCREASING SO FAR WITH SOME GUSTS TO
AROUND 45 MPH ACROSS PARTS OF THE REGION. THE WIND ADVISORY
THEREFORE REMAINS IN EFFECT FOR THE ENTIRE CWA. A PUBLIC
INFORMATION STATEMENT /PNS/ IS BEING UPDATED WITH SOME SNOWFALL
AMOUNTS FROM THIS MORNING AND WIND GUSTS SO FAR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE
HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS
WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING
OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR
AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING
SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS
THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA.
THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE
ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND.
THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY
EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING.
THE SECOND SHORT WAVE STRONGER LOW PRESSURE SYSTEM IN THE MIDWEST
WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT EVENTUALLY
MOVES OFF THE NJ OR DE COAST THURSDAY.
PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS.
WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY
OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE
ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF
BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON
12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50.
THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE
PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM
SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN
NCEP GUIDANCE SOLN FOR WED-FRI.
THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE
UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT
ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER
EVENT.
TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. NCEP MODEL GUIDANCE
APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF PCPN IS OCCURRING
ON WED-THU. USED HPC GUIDANCE TEMPS.
THE DAILIES...
SUNDAY NIGHT AND MONDAY...FAIR IN DRY SW FLOW WAA BEHIND THE DEPARTING
MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING START TO MONDAY
MORNING WARMS QUICKLY TO ABOVE NORMAL TEMPS IN THE AFTN WITH GUSTY
SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE. WILL THIS BE A FWX CONCERN
FOR AN SPS AFTN?
MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE.
TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES
OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN
ZONES.
TUESDAY NIGHT-WEDNESDAY...COMPLEX BUT A WARM FRONT WILL PRODUCE A
PERIOD OF PRECIPITATION WEDNESDAY..SOME OF IT EXPECTED TO BE SNOW
FROM KABE-KSMQ REGION NORTH AND MAYBE RIVALING ONE OF THE MORE
SIGNIFICANT SNOW EVENTS OF THE WINTER SO FAR. THAT SOUTHERN EDGE
OF WINTER WX IS NOT SET IN STONE BUT THATS THE BEST ESTIMATE I
CAN OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND REALIZING WE
ARE STILL IN MET WINTER. 12Z/25 HPC GUIDANCE TEMPS/WINDS.
WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS
NO WHERE TO GO BUT E OR ESE FORCED BY THE CONFLUENCE ZONE IN MAINE.
THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF LEFTOVER
DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR FA...THEN VERY
LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS EWD FROM NJ OR
DE AS PER THE ECMWF ON WED NIGHT...IT WILL HAVE THE BAROCLINIC
ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE THURSDAY
MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND NW NJ
AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ- KABE.
THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO PHIL.
12Z/25 HPC GUIDANCE TEMPS/WINDS.
FRIDAY...DRY CANADIAN HIGH PRES REASSERTS CONTROL HERE...BRIEFLY.
HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY
SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25 HPC
GUIDANCE AND NOT MUCH ENERGY INTO MODIFYING DATA FOR THIS DATE.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK
NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD
INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS
HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY
WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF TONIGHT.
THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS, HOWEVER THESE
ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING
SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST.
A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON
WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN
AND HIGH PRESSURE GETS A BIT CLOSER. ANY SNOW SHOWERS ARE EXPECTED
TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY
BE NORTH OF KABE. HOWEVER UNTIL THEN, SOME BRIEF REDUCTIONS IN THE
LOCAL VISIBILITIES AND CEILINGS MAY OCCUR. THE OVERALL IMPACT OF
THESE CARRIES SOME UNCERTAINTY, THEREFORE SOME SHORT-FUSED
AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK
TO IMPACT ANY LOCAL TERMINALS.
FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT
OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A
WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE
WEAKENING MORE BY LATE IN THE DAY. THERE APPEARS TO BE ENOUGH
DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT
ANY STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED.
OUTLOOK...
SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN.
WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY
PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE
TO OCNL IFR.
&&
.MARINE...
THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE
PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG
WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF
OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO
6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY.
THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO
LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE
GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED
LATER TONIGHT.
THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING...
BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS
SHOULD DROP BELOW SMALL CRAFT LEVELS.
OUTLOOK...
SUNDAY NIGHT...QUIET WITH LIGHT WIND.
MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN.
MONDAY NIGHT....NW SCA GUSTS POSSIBLE.
TUESDAY...NO HEADLINE.
WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER
A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH.
WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ
WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS.
UNCERTAINTY BUT ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS
20-30 KTS AT TIMES BY WED NIGHT AND THU.
&&
.TIDES/COASTAL FLOODING...
WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME
INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL
LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING.
FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR
NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON
DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW
WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY
MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT
CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE
APPROPRIATE STATEMENTS OR ADVISORIES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...HAYES/DRAG 213P
NEAR TERM...GORSE
SHORT TERM...RPW
LONG TERM...DRAG 213P
AVIATION...DRAG/GORSE 213P
MARINE...DRAG/GORSE 213P
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1202 PM EST SAT FEB 25 2012
.SYNOPSIS...
AN INTENSE AREA OF LOW PRESSURE WILL MOVE NORTHEASTWARD AND ACROSS THE
CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE OVER THE LOWER
MISSISSIPPI VALLEY WILL BUILD EAST, REACHING THE MID ATLANTIC
COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION MONDAY
NIGHT, FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD FRONT WILL
APPROACH THE AREA WEDNESDAY, THEN CROSS THE REGION WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EARLIER NARROW BUT BRIEFLY INTENSE SNOW BAND HAS WEAKENED AS
IT MOVED INTO PORTIONS OF SOUTHERN NEW JERSEY EARLIER. THIS
PRODUCED LOCALLY UP TO 1.5 INCHES OF SNOW IN A SHORT PERIOD OF
TIME IN PORTIONS OF SOUTHEASTERN PENNSYLVANIA. THE COMBINATION OF
STEEPENING LOW-LEVEL LAPSE RATES, CAA AND A DEEP CYCLONIC FLOW IS
ALLOWING ADDITIONAL SNOW SHOWERS TO DEVELOP. THESE TO MAY DEVELOP
INTO EAST TO WEST TYPE BANDS. BASED ON THE SOUNDINGS AND OBSERVING
VISIBLE SATELLITE IMAGERY, THE ACTIVITY DOES HAVE A CONVECTIVE
LOOK. THEREFORE, SOME LOCAL BUT BRIEF BURSTS OF SNOW ARE POSSIBLE
THROUGH THE AFTERNOON. THE CLOUDS HAVE EVEN CLEARED OUT BEHIND
SOME OF THE HEAVIER SNOW SHOWERS AS THE AIRMASS STABILIZES FOR A
TIME. WE WILL MAINLY CARRY CHC POPS ACROSS MOSTLY THE NORTHERN
HALF OF THE CWA TO ACCOUNT FOR THIS ACTIVITY. THE HRRR APPEARS TO
BE THE ONLY HIGH RESOLUTION GUIDANCE THAT HAS CAPTURED THE SNOW
BANDS DECENTLY SO FAR.
BASED ON THE FORECAST SOUNDINGS, THE STRONGER WINDS MAY ACTUALLY
OCCUR LATER THIS AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET
EVEN DEEPER MIXING ALONG WITH SOME STRONGER WINDS ALOFT. THE WINDS
HAVE BEEN SHOWING SIGNS OF INCREASING SO FAR WITH SOME GUSTS TO
AROUND 45 MPH ACROSS PARTS OF THE REGION. THE WIND ADVISORY
THEREFORE REMAINS IN EFFECT FOR THE ENTIRE CWA. A PUBLIC
INFORMATION STATEMENT /PNS/ IS BEING UPDATED WITH SOME SNOWFALL
AMOUNTS FROM THIS MORNING AND WIND GUSTS SO FAR.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE
HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS
WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING
OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR
AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE
PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT.
THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS
HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT
SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE
OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD
DO IT.
THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB
TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S
SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO
BE IN LINE WITH THE ABOVE THINKING.
DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD
RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE
PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND
SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE
NUMBERS WERE DROPPED BY 3 TO 8 DEGREES.
MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR
ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS
IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND
MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY
AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF
THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS.
THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND
MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE
AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS
SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE
IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE
UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS
SOME SNOW SHOWERS NEAR KMPO.
THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS
TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE
FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE
WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE
NORMAL ONCE AGAIN.
WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT
THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY
IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT
SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR
ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT
OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW
IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED
TO THE FORECAST FOR TUESDAY NIGHT.
WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING
PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A
WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE
SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT...
HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD
BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN
COULD EXTEND INTO WEDNESDAY MORNING.
MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE
DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET
WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION
AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE...
BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS
TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION
THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES
(WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A
HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND
ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM
FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF
YEAR.
THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW
BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE
POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY
LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT
WEEKEND.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK
NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD
INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS
HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY
WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF TONIGHT.
THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS, HOWEVER THESE
ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING
SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST.
A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON
WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN
AND HIGH PRESSURE GETS A BIT CLOSER. ANY SNOW SHOWERS ARE EXPECTED
TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY
BE NORTH OF KABE. HOWEVER UNTIL THEN, SOME BRIEF REDUCTIONS IN THE
LOCAL VISIBILITIES AND CEILINGS MAY OCCUR. THE OVERALL IMPACT OF
THESE CARRIES SOME UNCERTAINTY, THEREFORE SOME SHORT-FUSED
AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK
TO IMPACT ANY LOCAL TERMINALS.
FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT
OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A
WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE
WEAKENING MORE BY LATE IN THE DAY. THERE APPEARS TO BE ENOUGH
DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT
ANY STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED.
OUTLOOK...
WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED
SUNDAY NIGHT AND MONDAY.
A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS
POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF
SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST
WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY
NIGHT AND TUESDAY MORNING.
A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS
DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING
PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE
FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE.
WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW
LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS.
&&
.MARINE...
THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE
PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG
WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF
OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO
6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY.
THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO
LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE
GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED
LATER TONIGHT.
THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING...
BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS
SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF
THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING
BELOW SMALL CRAFT LEVELS DURING THAT TIME.
A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF
THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT
LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO
5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A
TIME LATE MONDAY NIGHT.
BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF
SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND
WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT
AND EARLY WEDNESDAY.
THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE
MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST.
THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE
FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY...
WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO
SOUTHEAST FLOW.
MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE
SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE
POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR
GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON
AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW
RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO
&&
.TIDES/COASTAL FLOODING...
WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME
INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL
LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING.
FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR
NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON
DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW
WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY
MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT
CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE
APPROPRIATE STATEMENTS OR ADVISORIES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS
EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...HAYES
NEAR TERM...GORSE
SHORT TERM...RPW
LONG TERM...HAYES
AVIATION...GORSE/HAYES
MARINE...GORSE/HAYES/RPW
TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
934 AM EST SAT FEB 25 2012
.SYNOPSIS...
LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING
WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE
MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION
MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD
FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A RATHER IMPRESSIVE BUT LOCALIZED EVENT THIS MORNING AS A FAIRLY
NARROW BAND OF MODERATE TO HEAVY SNOW HAS BEEN SETTLING
SOUTHEASTWARD ACROSS PORTIONS OF EASTERN PENNSYLVANIA. THIS BAND IS
GENERALLY ON THE NORTH SIDE OF A STRONG AREA OF CHANNELIZED
VORTICITY AND AHEAD OF AN UPPER-LEVEL TROUGH AXIS. THE NEARBY 12Z
RAOBS INDICATE STEEPER LOW-LEVEL LAPSE RATES WITH EVEN SOME WEAK
INSTABILITY PRESENT. THIS COMBINED WITH A DEEP CYCLONIC FLOW AND
CAA IS HELPING TO FOCUS THE NARROW BAND OF SNOW. THIS BAND HAS
PRODUCED UP TO 1.5 INCHES OF SNOW IN PORTIONS OF BERKS COUNTY.
SOME PENNDOT CAMERAS INDICATE THE VISIBILITY IS GREATLY REDUCED
WITHIN THIS BAND WITH THE SNOW QUICKLY ACCUMULATING. IT APPEARS
MOST OF THE ACCUMULATION IS ON NON ROADWAY SURFACES. AN EARLIER
UPDATE REFINED THE POPS BASED ON THE MOVEMENT OF THE BAND. THE
HRRR HAS THIS BAND BUT IT WAS A BIT TO FAR NORTH INITIALLY. THIS
BAND MAY TEND TO BREAK UP AS WE GET MORE OF A DIURNAL INFLUENCE TO
DISRUPT IT, HOWEVER STEEP LOW-LEVEL LAPSE RATES AND ENOUGH
MOISTURE MAY RESULT IN ADDITIONAL SNOW SHOWERS DEVELOPING THROUGH
THE AFTERNOON. THE HRRR IS SHOWING THIS POTENTIAL, THEREFORE WE
EXPANDED THE CHC POPS SOME THIS AFTERNOON. WE HAVE LOWER
CONFIDENCE WITH A SOUTHEASTERN EXTENT THOUGH, BUT FOR NOW ADDED IN
A SPRINKLE/FLURRY MENTION FOR SOME. THE STRATOCUMULUS SHOULD
DEVELOP AND EXPAND EASTWARD THROUGH THE AFTERNOON DUE TO LOW-LEVEL
HEATING AND ALSO STEEPENING LOW-LEVEL LAPSE RATES.
THE NEXT CONCERN TO TACKLE IS THE WINDS. SO FAR THE WINDS HAVE
BEEN A BIT LOWER AND THIS MAY BE A RESULT OF THE MIXING NOT QUITE
BEING ALL THAT DEEP JUST YET. BASED ON THE FORECAST SOUNDINGS, THE
PEAK WIND GUSTS /40 TO 50 MPH/ MAY ACTUALLY OCCUR LATER THIS
AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET EVEN DEEPER MIXING
ALONG WITH SOME STRONGER WINDS ALOFT. THE WIND ADVISORY THEREFORE
REMAINS IN EFFECT FOR THE ENTIRE CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE
HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS
WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING
OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR
AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE
PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT.
THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS
HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT
SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE
OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD
DO IT.
THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB
TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S
SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO
BE IN LINE WITH THE ABOVE THINKING.
DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD
RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE
PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND
SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE
NUMBERS WERE DROPPED BY 3 TO 8 DEGREES.
MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR
ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS
IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND
MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY
AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF
THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS.
THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND
MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE
AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS
SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE
IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE
UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS
SOME SNOW SHOWERS NEAR KMPO.
THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS
TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE
FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE
WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE
NORMAL ONCE AGAIN.
WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT
THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY
IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT
SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR
ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT
OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW
IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED
TO THE FORECAST FOR TUESDAY NIGHT.
WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING
PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A
WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE
SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT...
HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD
BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN
COULD EXTEND INTO WEDNESDAY MORNING.
MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE
DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET
WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION
AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE...
BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS
TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION
THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES
(WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A
HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND
ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM
FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF
YEAR.
THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW
BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE
POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY
LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT
WEEKEND.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE MAIN AREA OF CLOUDS ACROSS THE AREA HAS BEEN CONFINED TO
PORTIONS OF EASTERN PENNSYLVANIA WITH A HEAVIER SNOW BAND SO FAR.
THIS IS SETTLING SOUTHEASTWARD AND NEAR THE KRDG AREA. THIS MAY
NOT EXTEND FAR ENOUGH SOUTHEASTWARD TO IMPACT KPHL, KPNE AND KILG
THEREFORE NO MENTION WAS INCLUDED AT THIS TIME. ELSEWHERE,
STRATOCUMULUS SHOULD FILL IN THROUGH THE DAY WITH PERHAPS THE
LEAST AMOUNT OF COVERAGE NEAR KMIV AND KACY. OVERALL, VFR IS
EXPECTED WITH THE EXCEPTION IF A SNOW SHOWER MOVES THROUGH. THIS
WOULD REDUCE THE LOCAL VISIBILITIES QUITE A BIT FOR A TIME WITH
SOME LOWER CEILINGS.
AS THE VERTICAL MIXING DEEPENS THROUGH THE DAY, THE WINDS ARE
EXPECTED TO INCREASE SOME MORE WITH PEAK GUSTS NEAR 40 KNOTS BY
LATER THIS AFTERNOON. THE WINDS WILL REMAIN GUSTY FOR AWHILE THIS
EVENING, ALTHOUGH THE MIXING SHOULD SHRINK WITH TIME ALLOWING THE
WIND SPEEDS OVERALL TO COME DOWN THROUGH THE NIGHT. MOST OF THE
WINDS GUSTS SHOULD BE GONE AROUND MIDNIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST
SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS
DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN
THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED
SUNDAY NIGHT AND MONDAY.
A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS
POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF
SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST
WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY
NIGHT AND TUESDAY MORNING.
A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS
DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING
PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE
FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE.
WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW
LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS.
&&
.MARINE...
THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE
PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG
WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF
OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO
6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY.
THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO
LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE
GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED
LATER TONIGHT.
THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING...
BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS
SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF
THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING
BELOW SMALL CRAFT LEVELS DURING THAT TIME.
A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF
THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT
LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO
5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A
TIME LATE MONDAY NIGHT.
BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF
SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND
WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT
AND EARLY WEDNESDAY.
THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE
MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST.
THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE
FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY...
WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO
SOUTHEAST FLOW.
MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE
SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE
POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR
GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON
AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW
RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO
&&
.TIDES/COASTAL FLOODING...
WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME
INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL
LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING.
FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR
NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON
DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW
WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY
MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT
CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE
APPROPRIATE STATEMENTS OR ADVISORIES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS
EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS
EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...HAYES
NEAR TERM...GORSE
SHORT TERM...RPW
LONG TERM...HAYES
AVIATION...GORSE/HAYES
MARINE...GORSE/HAYES/RPW
TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
803 AM EST SAT FEB 25 2012
.SYNOPSIS...
LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING
WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE
MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION
MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD
FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE DEEP CYCLONIC FLOW IN CONJUNCTION WITH A STRONG AREA OF
CHANNELIZED VORTICITY AND CAA IS HELPING TO FOCUS A NARROW BAND OF
SNOW FROM NEAR WESTERN PENNSYLVANIA ALL THE WAY TO PORTIONS OF
EASTERN PENNSYLVANIA. A CHECK OF SOME PENNDOT CAMERAS INDICATED
THIS BAND IS PUTTING DOWN A QUICK COATING OF SNOW ACROSS A NARROW
AREA IN SCHUYLKILL COUNTY AND THIS HAS MOVED INTO NORTHERN BERKS
AND PORTIONS OF LEHIGH COUNTY TO EVEN UPPER BUCKS. IT APPEARS THE
GREATER THE PRECIPITATION INTENSITY IS IT FALLS AS SNOW, WHILE
SOME WEAKER RADAR RETURNS ESPECIALLY SOUTH OF THE BAND IS MAINLY
SPRINKLES. THE FORECAST HAS BEEN UPDATED TO ADD A NARROW RIBBON OF
LIKELY POPS FOR A TIME THIS MORNING. THE HRRR HAS THIS BAND BUT IT
IS A BIT TO FAR NORTH INITIALLY. THE HOURLY GRIDS WERE ALSO
TWEAKED A BIT.
OTHERWISE, OUR WEATHER EVENT TODAY WILL BE THE WIND. AS LOW PRESSURE
CONTINUES TO MOVE OFF TO THE NORTHEAST AWAY FROM OUR AREA, HIGH
PRESSURE WILL MOVE IN FROM THE WEST. THE PRESSURE GRADIENT BETWEEN
THESE TWO SYSTEMS WILL PRODUCE GUSTY WEST WINDS TODAY. WIND GUSTS
ARE EXPECTED TO REACH TO AROUND 45 MPH ESPECIALLY FROM LATER THIS
MORNING INTO THE EVENING HOURS. A WIND ADVISORY REMAINS IN EFFECT
UNTIL 7 PM TODAY FOR THE ENTIRE CWA. THE WIND WILL MAKE IT FEEL
LIKE ITS IN THE 20S NORTH AND MAINLY 30S ELSEWHERE. SKIES WILL BE
PARTLY TO MOSTLY SUNNY SOUTH AND PARTLY CLOUDY TO CLOUDY NORTH.
OUTSIDE OF THE BAND THIS MORNING, THERE WILL BE SCATTERED SNOW
SHOWERS OR FLURRIES ESPECIALLY IN THE NORTHERN MOUNTAINS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE
HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS
WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING
OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR
AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE
PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT.
THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS
HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT
SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE
OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD
DO IT.
THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB
TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S
SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO
BE IN LINE WITH THE ABOVE THINKING.
DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD
RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE
PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND
SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE
NUMBERS WERE DROPPED BY 3 TO 8 DEGREES.
MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR
ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS
IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND
MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY
AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF
THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS.
THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND
MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE
AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS
SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE
IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE
UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS
SOME SNOW SHOWERS NEAR KMPO.
THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS
TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE
FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE
WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE
NORMAL ONCE AGAIN.
WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT
THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY
IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT
SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR
ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT
OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW
IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED
TO THE FORECAST FOR TUESDAY NIGHT.
WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING
PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A
WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE
SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT...
HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD
BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN
COULD EXTEND INTO WEDNESDAY MORNING.
MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE
DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET
WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION
AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE...
BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS
TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION
THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES
(WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A
HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND
ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM
FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF
YEAR.
THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW
BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE
POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY
LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT
WEEKEND.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SCT TO BKN SC ARE
OCCURRING IN SOME OF OUR NORTHERN AND WESTERN AREAS. THE WIND WILL
CONTINUE TO BE THE MAIN WEATHER FACTOR TODAY. WHILE SPEEDS HAVE
DROPPED OFF SOME EARLY THIS MORNING, THEY WILL INCREASE AGAIN BY
MID OR LATE MORNING. SUSTAINED W WINDS WILL RUN IN THE LOWER TO
MID 20S WITH GUSTS APPROACHING 40 KT. THE STRONG WINDS AND COLD
AIR ADVECTION WILL CAUSE THE SC TO OVERSPREAD MUCH OF THE AREA
TODAY. SNOW SHOWERS OR FLURRIES SHOULD BE LIMITED TO OUR NORTHWESTERN
AREAS WITH THESE GETTING CLOSE TO KRDG AND KABE. THESE MAY REDUCE
THE LOCAL CEILINGS AND VISIBILITIES FOR A TIME BUT SO FAR THIS MORNING
A MAIN BAND IS BETWEEN KRDG AND KABE. ONCE THE SUN SETS, WINDS
WILL BEGIN TO DIMINISH AND SKIES WILL CLEAR. MOST OF THE WINDS
GUSTS SHOULD BE GONE BY OR SHORTLY AFTER MIDNIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST
SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS
DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN
THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED
SUNDAY NIGHT AND MONDAY.
A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS
POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF
SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST
WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY
NIGHT AND TUESDAY MORNING.
A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS
DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING
PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE
FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE.
WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW
LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS.
&&
.MARINE...
THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE
PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG
W WINDS TODAY. A GALE WARNING IS IN EFFECT ON ALL OF OUR WATERS
UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET
ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL
CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT
AS THE HIGH PRESSURE SYSTEM TO OUR WEST APPROACHES. ONCE THE GALE
WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER
TONIGHT.
THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING...
BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS
SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF
THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING
BELOW SMALL CRAFT LEVELS DURING THAT TIME.
A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF
THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT
LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO
5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A
TIME LATE MONDAY NIGHT.
BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF
SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND
WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT
AND EARLY WEDNESDAY.
THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE
MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST.
THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE
FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY...
WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO
SOUTHEAST FLOW.
MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE
SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE
POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR
GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON
AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW
RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO
&&
.TIDES/COASTAL FLOODING...
WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME
INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL
LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING.
FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR
NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON
DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW
WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY
MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT
CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE
APPROPRIATE STATEMENTS OR ADVISORIES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS
EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS
EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...HAYES
NEAR TERM...GORSE/RPW
SHORT TERM...RPW
LONG TERM...HAYES
AVIATION...GORSE/HAYES/RPW
MARINE...HAYES/RPW
TIDES/COASTAL FLOODING...RPW
CORRECTED SOME WORDING IN THE NEAR TERM.
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
753 AM EST SAT FEB 25 2012
.SYNOPSIS...
LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING
WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE
OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE
MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION
MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD
FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE DEEP CYCLONIC FLOW IN CONJUNCTION WITH A STRONG AREA OF
CHANNELIZED VORTICITY AND CAA IS HELPING TO FOCUS A NARROW BAND OF
SNOW FROM NEAR WESTERN PENNSYLVANIA ALL THE WAY TO PORTIONS OF
EASTERN PENNSYLVANIA. A CHECK OF SOME PENNDOT CAMERAS INDICATED
THIS BAND IS PUTTING DOWN A QUICK COATING SNOW IN A NARROW AREA IN
SCHUYLKILL COUNTY AND THIS HAS MOVED INTO NORTHERN BERKS AND
PORTIONS OF LEHIGH COUNTY. IT APPEARS THE GREATER THE
PRECIPITATION INTENSITY IS IT FALLS AS SNOW, WHILE SOME WEAKER RADAR
RETURNS ESPECIALLY SOUTH OF THE BAND IS MAINLY SPRINKLES. THE
FORECAST HAS BEEN UPDATED TO ADD A NARROW RIBBON OF LIKELY POPS
FOR A TIME THIS MORNING. THE HRRR HAS THIS BAND BUT IT IS A BIT TO
FAR NORTH INITIALLY. THE HOURLY GRIDS WERE ALSO TWEAKED A BIT.
OTHERWISE, OUR WEATHER EVENT TODAY WILL BE THE WIND. AS LOW PRESSURE
CONTINUES TO MOVE OFF TO THE NORTHEAST AWAY FROM OUR AREA, HIGH
PRESSURE WILL MOVE IN FROM THE WEST. THE PRESSURE GRADIENT BETWEEN
THESE TWO SYSTEMS WILL PRODUCE GUSTY WEST WINDS TODAY. WIND GUSTS
ARE EXPECTED TO REACH TO AROUND 45 MPH ESPECIALLY FROM LATER THIS
MORNING INTO THE EVENING HOURS. A WIND ADVISORY REMAINS IN EFFECT
UNTIL 7 PM TODAY FOR THE ENTIRE CWA. THE WIND WILL MAKE IT FEEL
LIKE ITS IN THE 20S NORTH AND MAINLY 30S ELSEWHERE. SKIES WILL BE
PARTLY TO MOSTLY SUNNY SOUTH AND PARTLY CLOUDY TO CLOUDY NORTH.
OUTSIDE OF THE BAND THIS MORNING, THERE WILL BE SCATTERED SNOW
SHOWERS OR FLURRIES ESPECIALLY IN THE NORTHERN MOUNTAINS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE
HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS
WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING
OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR
AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE
PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT.
THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS
HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT
SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE
OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD
DO IT.
THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB
TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S
SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO
BE IN LINE WITH THE ABOVE THINKING.
DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD
RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE
PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND
SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE
NUMBERS WERE DROPPED BY 3 TO 8 DEGREES.
MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR
ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS
IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND
MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY
AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF
THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS.
THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND
MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE
AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS
SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE
IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE
UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS
SOME SNOW SHOWERS NEAR KMPO.
THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS
TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE
FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE
WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE
NORMAL ONCE AGAIN.
WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT
THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY
IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT
SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR
ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT
OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW
IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED
TO THE FORECAST FOR TUESDAY NIGHT.
WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING
PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A
WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE
SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT...
HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD
BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN
COULD EXTEND INTO WEDNESDAY MORNING.
MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE
DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET
WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION
AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE...
BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS
TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION
THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES
(WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A
HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND
ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM
FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF
YEAR.
THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW
BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE
POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY
LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT
WEEKEND.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SCT TO BKN SC ARE
OCCURRING IN SOME OF OUR NORTHERN AND WESTERN AREAS. THE WIND WILL
CONTINUE TO BE THE MAIN WEATHER FACTOR TODAY. WHILE SPEEDS HAVE
DROPPED OFF SOME EARLY THIS MORNING, THEY WILL INCREASE AGAIN BY
MID OR LATE MORNING. SUSTAINED W WINDS WILL RUN IN THE LOWER TO
MID 20S WITH GUSTS APPROACHING 40 KT. THE STRONG WINDS AND COLD
AIR ADVECTION WILL CAUSE THE SC TO OVERSPREAD MUCH OF THE AREA
TODAY. SNOW SHOWERS OR FLURRIES SHOULD BE LIMITED TO OUR NORTHWESTERN
AREAS WITH THESE GETTING CLOSE TO KRDG AND KABE. THESE MAY REDUCE
THE LOCAL CEILINGS AND VISIBILITIES FOR A TIME BUT SO FAR THIS MORNING
A MAIN BAND IS BETWEEN KRDG AND KABE. ONCE THE SUN SETS, WINDS
WILL BEGIN TO DIMINISH AND SKIES WILL CLEAR. MOST OF THE WINDS
GUSTS SHOULD BE GONE BY OR SHORTLY AFTER MIDNIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST
SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS
DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN
THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED
SUNDAY NIGHT AND MONDAY.
A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS
POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF
SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST
WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY
NIGHT AND TUESDAY MORNING.
A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS
DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING
PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE
FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE.
WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW
LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS.
&&
.MARINE...
THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE
PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG
W WINDS TODAY. A GALE WARNING IS IN EFFECT ON ALL OF OUR WATERS
UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET
ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL
CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT
AS THE HIGH PRESSURE SYSTEM TO OUR WEST APPROACHES. ONCE THE GALE
WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER
TONIGHT.
THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING...
BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS
SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF
THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING
BELOW SMALL CRAFT LEVELS DURING THAT TIME.
A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF
THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT
LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO
5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A
TIME LATE MONDAY NIGHT.
BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF
SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY
MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND
WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT
AND EARLY WEDNESDAY.
THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE
MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST.
THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE
FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY...
WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO
SOUTHEAST FLOW.
MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE
SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE
POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR
GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON
AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW
RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO
&&
.TIDES/COASTAL FLOODING...
WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME
INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL
LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING.
FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR
NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON
DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW
WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY
MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT
CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE
APPROPRIATE STATEMENTS OR ADVISORIES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055-
060>062-067>071.
NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010-
012>027.
DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004.
MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015-
019-020.
MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS
EVENING FOR ANZ450>455.
GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS
EVENING FOR ANZ430-431.
&&
$$
SYNOPSIS...HAYES
NEAR TERM...GORSE/RPW
SHORT TERM...RPW
LONG TERM...HAYES
AVIATION...GORSE/HAYES/RPW
MARINE...HAYES/RPW
TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
916 PM CST SUN FEB 26 2012
.DISCUSSION...
916 PM CST
SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT
DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST
AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING
AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE
AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN
NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT
ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE
FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY
ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL
PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN
GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER
THE FRONT.
A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS
DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR
WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE
MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST
CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A
GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT
CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY
OVERNIGHT AND SLOWLY SHIFT EAST.
THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE
DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT
ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES
BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE
BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING
MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE.
&&
.PREV DISCUSSION...
320 PM CST
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN
WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE
UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS
PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED
FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH
STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN
CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH
MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT
COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER.
HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE
SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED
TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO
BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES
THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL
EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT
TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT
ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD
COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN
PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN
BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO
THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER
20S TO LOWER 30S ELSEWHERE.
FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH
WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH
PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS.
SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF
I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL
DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS
THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND
ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS
CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE
MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE
WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN
SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND
UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE
THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO
OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE
THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING
WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE
NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND
MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE
EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY
AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL
EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE
THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK
THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES
THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES
IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE
PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS
THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME
LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM
FOR WEDNESDAY AFTERNOON AND EVENING.
FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH
SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN
INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE.
THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO
SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM
WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC
LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO
CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER
CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR
THE NORTHERN PORTIONS OF THE CWA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* COLD FRONT MOVING THROUGH WITH SHIFT TO WEST WINDS.
* WEST WINDS GUSTING 20-25 KTS FOR A TIME MONDAY MORNING BEFORE
DECREASING AGAIN DURING THE AFTERNOON.
* VERY LOW PROBABILITY FOR A BRIEF PERIOD OF 2000-3000 FT BKN
CEILING MID MORNING MONDAY.
RATZER
//DISCUSSION...UPDATED 03Z...
FRONT MAKING A LITTLE FASTER PROGRESS ACROSS NORTHERN IL THAN
PREVIOUSLY ANTICIPATED...WITH BOUNDARY NOW MOVING INTO CHI
TERMINALS. WILL LIKELY SEE A BRIEF PERIOD OF 280-ISH WITH GUSTS
NEAR 20 KTS WITH FROPA...THEN EXPECT WINDS TO SETTLE BACK TO A
260-ISH DIRECTION AFTER A COUPLE OF HOURS. ALSO...IR SATELLITE
IMAGERY AND METARS AROUND KVYS INDICATES SOME CLOUD DEVELOPMENT
AROUND 8000 FT AGL. 01Z RUC MODEL RUN SUGGESTS THIS MAY BECOME
MORE WIDESPREAD PERHAPS OVER OR JUST EAST OF THE CHICAGO AREA OVER
THE NEXT SEVERAL HOURS. HAVE INCLUDED A PERIOD OF VFR CEILING AT
GYY FOR THIS...WHICH BEING FARTHER EAST HAS THE GREATER POTENTIAL
FOR DEVELOPING A VFR CIG.
RATZER
PREVIOUS DISCUSSION FROM 00Z...
LOW PRESSURE OVER NORTHWEST WISCONSIN THIS EVENING WILL CONTINUE
TO WEAKEN AS IT TRACKS EAST ACROSS THE NORTHERN LAKES TONIGHT...
AND WILL TRAIL A COLD FRONT FROM WEST TO EAST ACROSS THE TERMINALS
OVERNIGHT. GUSTY SOUTH WINDS ALREADY QUICKLY DIMINISHING AS
PRESSURE GRADIENT WEAKENS IN ADVANCE OF THE COLD FRONTAL TROUGH...
AND EXPECT WINDS TO CONTINUE TO DIMINISH AND GRADUALLY VEER
SOUTHWEST THIS EVENING. ACTUAL FRONTAL PASSAGE ANTICIPATED
OVERNIGHT WITH A WIND SHIFT TO THE WEST...AND GUSTS PICKING BACK
UP INTO THE 20-25 KT RANGE FOR A TIME MONDAY MORNING AS LOW LEVEL
MIXING DEEPENS WITH COLD ADVECTION BEHIND THE FRONT AND A RETURN
OF TIGHTER SURFACE PRESSURE GRADIENT. HIGH PRESSURE WILL BUILD
EAST FAIRLY QUICKLY HOWEVER...ALLOWING PRESSURE GRADIENT TO
WEAKEN AGAIN FROM THE WEST DURING THE AFTERNOON HOURS. WINDS WILL
THEN SHIFT NORTHWEST AND DECREASE BELOW 10 KTS EARLY MONDAY
EVENING AS SURFACE HIGH MOVES IN FROM THE WEST.
CLOUD WISE...ONLY A LITTLE PATCHY CIRRUS ACROSS REGION IN
OTHERWISE DRY ATMOSPHERE. POTENTIAL DOES EXIST FOR SOME FLAT
STRATOCU TO DEVELOP MONDAY MORNING AS LOW LEVEL LAPSE RATES
STEEPEN AND MIXED LAYER DEEPENS A BIT BEHIND THE COLD FRONT. CLOUD
BASES IN THE 2000-3000 FT AGL RANGE POSSIBLE AND COULD PERHAPS EVEN
FORM A BRIEF BROKEN DECK FOR A TIME MID-LATE MORNING...THOUGH THIS
APPEARS A LOW PROBABILITY AS AIR SPREADING IN FROM THE
WEST/NORTHWEST IS ALSO VERY DRY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN VFR CONDITIONS.
* LOW CONFIDENCE IN SCT020-030 BECOMING A BRIEF BROKEN CEILING MONDAY
MORNING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR
POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT.
WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE
OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE.
SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE.
RATZER
&&
.MARINE...
320 PM CST
WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW
GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL
CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN
HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER
PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW.
WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT
PASSES OVER THE LAKE AROUND MIDNIGHT.
HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON
AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM
NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN
LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES
ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING.
WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE
MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL
STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE
SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE
BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE
LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL
SOLUTIONS...KEPT WINDS AT LOW GALES.
IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE
SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS
SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT
WINDS AT SUB GALES FOR NOW.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
911 PM CST SUN FEB 26 2012
.DISCUSSION...
320 PM CST
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN
WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE
UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS
PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED
FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH
STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN
CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH
MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT
COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER.
HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE
SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED
TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO
BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES
THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL
EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT
TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT
ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD
COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN
PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN
BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO
THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER
20S TO LOWER 30S ELSEWHERE.
FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH
WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH
PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS.
SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF
I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL
DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS
THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND
ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS
CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE
MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE
WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN
SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND
UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE
THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO
OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE
THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING
WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE
NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND
MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE
EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY
AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL
EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE
THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK
THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES
THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES
IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE
PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS
THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME
LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM
FOR WEDNESDAY AFTERNOON AND EVENING.
FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH
SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN
INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE.
THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO
SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM
WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC
LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO
CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER
CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR
THE NORTHERN PORTIONS OF THE CWA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* COLD FRONT MOVING THROUGH WITH SHIFT TO WEST WINDS.
* WEST WINDS GUSTING 20-25 KTS FOR A TIME MONDAY MORNING BEFORE
DECREASING AGAIN DURING THE AFTERNOON.
* VERY LOW PROBABILITY FOR A BRIEF PERIOD OF 2000-3000 FT BKN
CEILING MID MORNING MONDAY.
RATZER
//DISCUSSION...UPDATED 03Z...
FRONT MAKING A LITTLE FASTER PROGRESS ACROSS NORTHERN IL THAN
PREVIOUSLY ANTICIPATED...WITH BOUNDARY NOW MOVING INTO CHI
TERMINALS. WILL LIKELY SEE A BRIEF PERIOD OF 280-ISH WITH GUSTS
NEAR 20 KTS WITH FROPA...THEN EXPECT WINDS TO SETTLE BACK TO A
260-ISH DIRECTION AFTER A COUPLE OF HOURS. ALSO...IR SATELLITE
IMAGERY AND METARS AROUND KVYS INDICATES SOME CLOUD DEVELOPMENT
AROUND 8000 FT AGL. 01Z RUC MODEL RUN SUGGESTS THIS MAY BECOME
MORE WIDESPREAD PERHAPS OVER OR JUST EAST OF THE CHICAGO AREA OVER
THE NEXT SEVERAL HOURS. HAVE INCLUDED A PERIOD OF VFR CEILING AT
GYY FOR THIS...WHICH BEING FARTHER EAST HAS THE GREATER POTENTIAL
FOR DEVELOPING A VFR CIG.
RATZER
PREVIOUS DISCUSSION FROM 00Z...
LOW PRESSURE OVER NORTHWEST WISCONSIN THIS EVENING WILL CONTINUE
TO WEAKEN AS IT TRACKS EAST ACROSS THE NORTHERN LAKES TONIGHT...
AND WILL TRAIL A COLD FRONT FROM WEST TO EAST ACROSS THE TERMINALS
OVERNIGHT. GUSTY SOUTH WINDS ALREADY QUICKLY DIMINISHING AS
PRESSURE GRADIENT WEAKENS IN ADVANCE OF THE COLD FRONTAL TROUGH...
AND EXPECT WINDS TO CONTINUE TO DIMINISH AND GRADUALLY VEER
SOUTHWEST THIS EVENING. ACTUAL FRONTAL PASSAGE ANTICIPATED
OVERNIGHT WITH A WIND SHIFT TO THE WEST...AND GUSTS PICKING BACK
UP INTO THE 20-25 KT RANGE FOR A TIME MONDAY MORNING AS LOW LEVEL
MIXING DEEPENS WITH COLD ADVECTION BEHIND THE FRONT AND A RETURN
OF TIGHTER SURFACE PRESSURE GRADIENT. HIGH PRESSURE WILL BUILD
EAST FAIRLY QUICKLY HOWEVER...ALLOWING PRESSURE GRADIENT TO
WEAKEN AGAIN FROM THE WEST DURING THE AFTERNOON HOURS. WINDS WILL
THEN SHIFT NORTHWEST AND DECREASE BELOW 10 KTS EARLY MONDAY
EVENING AS SURFACE HIGH MOVES IN FROM THE WEST.
CLOUD WISE...ONLY A LITTLE PATCHY CIRRUS ACROSS REGION IN
OTHERWISE DRY ATMOSPHERE. POTENTIAL DOES EXIST FOR SOME FLAT
STRATOCU TO DEVELOP MONDAY MORNING AS LOW LEVEL LAPSE RATES
STEEPEN AND MIXED LAYER DEEPENS A BIT BEHIND THE COLD FRONT. CLOUD
BASES IN THE 2000-3000 FT AGL RANGE POSSIBLE AND COULD PERHAPS EVEN
FORM A BRIEF BROKEN DECK FOR A TIME MID-LATE MORNING...THOUGH THIS
APPEARS A LOW PROBABILITY AS AIR SPREADING IN FROM THE
WEST/NORTHWEST IS ALSO VERY DRY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN VFR CONDITIONS.
* LOW CONFIDENCE IN SCT020-030 BECOMING A BRIEF BROKEN CEILING MONDAY
MORNING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR
POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT.
WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE
OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE.
SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE.
RATZER
&&
.MARINE...
320 PM CST
WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW
GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL
CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN
HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER
PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW.
WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT
PASSES OVER THE LAKE AROUND MIDNIGHT.
HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON
AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM
NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN
LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES
ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING.
WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE
MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL
STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE
SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE
BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE
LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL
SOLUTIONS...KEPT WINDS AT LOW GALES.
IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE
SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS
SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT
WINDS AT SUB GALES FOR NOW.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1120 AM CST SAT FEB 25 2012
.DISCUSSION...
ISSUED 958 AM CST SAT FEB 25 2012
STILL SEEING SOME LINGERING CLOUD COVER...MAINLY IN BANDS FROM
MACOMB SOUTHEAST INTO LAWRENCEVILLE...AND PEORIA TO DANVILLE. JUST
SOME LINGERING FLURRIES LINGERING...MAINLY IN THE SOUTHEAST...
ALTHOUGH LAWRENCEVILLE VISIBILITY HAD DROPPED TO 4 MILES IN LIGHT
SNOW LAST HOUR. STILL AM EXPECTING TO SEE THESE FEATURES
DIMINISHING OVER THE NEXT FEW HOURS...ALTHOUGH RUC CU-RULE SUGGEST
THE CLOUDS OVER THE SOUTHEAST LINGERING TO NEARLY MID-AFTERNOON.
HAVE SEEN WINDS GUSTING FROM 30-35 MPH THIS MORNING.
HOWEVER...THESE WILL STEADILY DIMINISH THE NEXT SEVERAL HOURS...
AS SURFACE RIDGING OVER WESTERN MISSOURI BUILDS EASTWARD.
HAVE SENT SOME UPDATED GRIDS TO ADJUST THE SKY COVER AND WIND
TRENDS. ZONE UPDATE THAT WAS ISSUED AROUND 5 AM IS STILL OK...BUT
WILL BE UPDATED CLOSER TO NOON TO REMOVE MORNING WORDING.
GEELHART
&&
.AVIATION...
ISSUED 1120 AM CST SAT FEB 25 2012
STILL SEEING A BIT OF MVFR CEILINGS LINGERING LATE THIS MORNING...
HOWEVER THESE SHOULD BE LIFTING THROUGH 20Z AS CLOUDS AND WINDS
DIMINISH FROM THE WEST. SURFACE HIGH PRESSURE WILL MOVE EAST
ACROSS THE TAF SITES THIS EVENING...WITH SOUTHEAST WINDS
INCREASING OVERNIGHT. HAVE INTRODUCED LLWS MENTION AT KPIA/KSPI
LATE IN THE NIGHT...AS A 50-60 KNOT LOW LEVEL JET APPROACHES FROM
THE WEST AHEAD OF A COLD FRONT IN THE PLAINS. BY THE TIME THE
CORE OF THIS JET MOVES OVER THE REMAINDER OF THE TAF SITES...DAYTIME
MIXING WILL BRING SOME OF THESE WINDS DOWN TO THE SURFACE...SO
HAVE GONE WITH 30-35 KNOT SURFACE GUSTS LATE IN THE PERIOD.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SAT FEB 25 2012
ASIDE FROM A CHANCE OF FLURRIES INTO MID MORNING...DRY WEATHER
EXPECTED OVER CENTRAL IL THROUGH MONDAY NIGHT. MORE ACTIVE WEATHER
PATTERN EXPECTED DURING THE MIDDLE AND LATER PART OF NEXT WEEK
WITH TWO DEEPENING LOW PRESSURE SYSTEMS EJECTING NE ACROSS THE
MIDWEST. WINTER LIKE TEMPERATURES EXPECTED TODAY THEN WARM UP
SUNDAY WITH STRONG SOUTHERLY WINDS AND ABOVE NORMAL TEMPERATURES
OVERALL NEXT WEEK...WHICH HAS BEEN THE NORM THIS PAST WINTER.
SHORT TERM...TODAY THROUGH MONDAY NIGHT
VERY STRONG AND STILL DEEPENING 977 MB LOW PRESSURE OFF THE MAINE
COAST AND STRONG 512 DM 500 MB LOW ALONG THE SOUTHERN
QUEBEC/ONTARIO PROVINCE LINE AND FAIRLY STRONG UPPER LEVEL TROF
OVER THE GREAT LAKES AND OHIO VALLEY STILL INFLUENCING CENTRAL IL
WEATHER THIS MORNING. HAVE PATCHES OF CLOUDS AND FLURRIES PIVOTING
THROUGH WITH BRISK WNW WINDS GUSTING 15 TO 30 MPH. TEMPS MOSTLY IN
THE UPPER 20S AND LOWER 30S...BUT COOLER MID 20S FROM I-74 NE.
DEWPOINTS GENERALLY IN THE UPPER TEENS AND LOWER 20S.
FAIRLY STRONG SHORT WAVES STILL AFFECTING IL THIS MORNING AND TO
GIVE PARTLY TO MOSTLY CLOUDY SKIES WITH A CHANCE OF FLURRIES INTO
MID MORNING ESPECIALLY EAST CENTRAL IL ALONG WITH BRISK WNW WINDS.
1030 MB HIGH PRESSURE OVER EAST TX AND RIDGING NORTHWARD ACROSS
THE GREAT PLAINS WILL SHIFT EAST INTO THE MS VALLEY THIS AFTERNOON
DECREASING CLOUDS AND WINDS. COOL HIGHS FROM 32-38F WITH MILDEST
READINGS IN SE IL AND SW OF SPRINGFIELD.
HIGH PRESSURE DRIFTS EAST INTO THE CENTRAL APPALACHIANS OVERNIGHT
WHILE LOW PRESSURE EMERGES INTO THE NORTHERN PLAINS BY DAWN
SUNDAY. LOWS TONIGHT IN THE LOW TO MID 20S AND LIKELY REACHED BY
MIDNIGHT WITH NEARLY STEADY OVERNIGHT WITH SSE WINDS INCREASING TO
10-20 MPH BY SUNRISE SUNDAY.
LOW PRESSURE TRACKS EAST TOWARD UPPER MI BY MIDNIGHT SUNDAY NIGHT
WITH STRONG PRESSURE GRADIENT SETTING UP OVER IL AND STRONG SOUTH
WINDS WITH GUSTS 30 TO 40 MPH. HIGHS IN THE 30S TODAY JUMP UP INTO
THE 50S SUNDAY AFTERNOON WITH MOSTLY SUNNY SKIES. FRONTAL BOUNDARY
TO PRESS SE ACROSS CENTRAL IL BY OVERNIGHT SUNDAY NIGHT AND PASSES
THROUGH DRY WITH UPPER LEVEL DYNAMICS PASSING NORTH OVER THE GREAT
LAKES REGION AND DEEPER MOISTURE FROM THE GULF OF MEXICO CUT OFF
BY HIGH PRESSURE RIDGE FROM THE MID ATLANTIC STATES AND RIDGING
WSW ACROSS DIXIE.
MOSTLY SUNNY SKIES AGAIN MONDAY AND A BIT COOLER OVER CENTRAL IL
BEHIND THE FRONT WITH HIGHS RANGING FROM THE MID 40S NORTH OF
PEORIA AND MID 50S IN SE IL.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST AND MOST MODELS
CONTINUE DRY CONDITIONS MONDAY NIGHT AND THEN SPREAD RAIN SHOWERS
ACROSS IL DURING TUE AND ESPECIALLY TUE NIGHT. IL GETTING
ESTABLISHED IN A MORE SW UPPER LEVEL FLOW WITH TWO LOW PRESSURE
SYSTEMS DEEPENING NE INTO THE MIDWEST AND KEEPING IL ON THE MILDER
SIDE OF THE STORM TRACK. BEST CHANCES OF SHOWERS AND POSSIBLE
THUNDERSTORMS WILL BE TUE AFTERNOON AND TUE NIGHT. CENTRAL AND SE
IL GETS DRY SLOTTED DURING WED WITH BEST CHANCES OF PRECIPITATION
NORTH AND EAST OF CENTRAL IL. ANOTHER STRONG LOW PRESSURE QUICKLY
ON ITS HEALS AND DEEPENS INTO THE MIDWEST FRI AND FRI NIGHT WITH
NEXT CHANCE OF PRECIPITATION WHICH APPEARS TO BE MAINLY RAIN AGAIN
WITH LOW PRESSURE TRACK NORTH OF CENTRAL IL. KEEPING TEMPS ABOVE
NORMAL DURING NEXT WEEK AS WE HEAD INTO EARLY MARCH.
KH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
958 AM CST SAT FEB 25 2012
.DISCUSSION...
ISSUED 958 AM CST SAT FEB 25 2012
STILL SEEING SOME LINGERING CLOUD COVER...MAINLY IN BANDS FROM
MACOMB SOUTHEAST INTO LAWRENCEVILLE...AND PEORIA TO DANVILLE. JUST
SOME LINGERING FLURRIES LINGERING...MAINLY IN THE SOUTHEAST...
ALTHOUGH LAWRENCEVILLE VISIBILITY HAD DROPPED TO 4 MILES IN LIGHT
SNOW LAST HOUR. STILL AM EXPECTING TO SEE THESE FEATURES
DIMINISHING OVER THE NEXT FEW HOURS...ALTHOUGH RUC CU-RULE SUGGEST
THE CLOUDS OVER THE SOUTHEAST LINGERING TO NEARLY MID-AFTERNOON.
HAVE SEEN WINDS GUSTING FROM 30-35 MPH THIS MORNING.
HOWEVER...THESE WILL STEADILY DIMINISH THE NEXT SEVERAL HOURS...
AS SURFACE RIDGING OVER WESTERN MISSOURI BUILDS EASTWARD.
HAVE SENT SOME UPDATED GRIDS TO ADJUST THE SKY COVER AND WIND
TRENDS. ZONE UPDATE THAT WAS ISSUED AROUND 5 AM IS STILL OK...BUT
WILL BE UPDATED CLOSER TO NOON TO REMOVE MORNING WORDING.
GEELHART
&&
.AVIATION...
ISSUED 541 AM CST SAT FEB 25 2012...FOR THE 12Z TAFS
A WEAK SURFACE IMPULSE COMBINED WITH THE UPPER TROUGH AXIS WILL
KEEP MVFR CLOUDS WITH FLURRIES AND LIGHT SNOW SHOWERS AROUND THIS
MORNING. A FEW PERIODS OF MVFR VIS MAY RESULT FROM ANY HEAVIER
SNOW BURSTS. A DUSTING OF SNOW COULD ACCUMULATE FROM THE HEAVIER
SNOWS...BUT OVERALL LITTLE ACCUMULATION IS EXPECTED.
WINDS JUST OFF THE SURFACE ARE STILL RATHER BRISK, AND WIND GUSTS
ARE EXPECTED TO RETURN AS MIXING HEIGHTS INCREASE. WE SHOULD SEE
NORTHWEST WINDS GUSTING AROUND 20 KT AT TIMES...ESPECIALLY THIS
MORNING. THAT SHOULD HELP TO BLOW SNOW OFF OF MANY TRAVEL
SURFACES. HOWEVER...SOME SLIPPERY CONDITIONS COULD LINGER TODAY AS
TEMPS CLIMB ONLY SLIGHTLY ABOVE FREEZING.
WINDS WILL DIMINISH LATER THIS AFTERNOON...AND BECOME VARIABLE
TONIGHT AS THE HIGH PRESSURE PULLS OFF TO THE EAST. A SOUTHEAST
WIND IS EVENTUALLY EXPECTED TO DEVELOP BY LATE TONIGHT...UNDER
MOSTLY CLEAR SKIES.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 330 AM CST SAT FEB 25 2012
ASIDE FROM A CHANCE OF FLURRIES INTO MID MORNING...DRY WEATHER
EXPECTED OVER CENTRAL IL THROUGH MONDAY NIGHT. MORE ACTIVE WEATHER
PATTERN EXPECTED DURING THE MIDDLE AND LATER PART OF NEXT WEEK
WITH TWO DEEPENING LOW PRESSURE SYSTEMS EJECTING NE ACROSS THE
MIDWEST. WINTER LIKE TEMPERATURES EXPECTED TODAY THEN WARM UP
SUNDAY WITH STRONG SOUTHERLY WINDS AND ABOVE NORMAL TEMPERATURES
OVERALL NEXT WEEK...WHICH HAS BEEN THE NORM THIS PAST WINTER.
SHORT TERM...TODAY THROUGH MONDAY NIGHT
VERY STRONG AND STILL DEEPENING 977 MB LOW PRESSURE OFF THE MAINE
COAST AND STRONG 512 DM 500 MB LOW ALONG THE SOUTHERN
QUEBEC/ONTARIO PROVINCE LINE AND FAIRLY STRONG UPPER LEVEL TROF
OVER THE GREAT LAKES AND OHIO VALLEY STILL INFLUENCING CENTRAL IL
WEATHER THIS MORNING. HAVE PATCHES OF CLOUDS AND FLURRIES PIVOTING
THROUGH WITH BRISK WNW WINDS GUSTING 15 TO 30 MPH. TEMPS MOSTLY IN
THE UPPER 20S AND LOWER 30S...BUT COOLER MID 20S FROM I-74 NE.
DEWPOINTS GENERALLY IN THE UPPER TEENS AND LOWER 20S.
FAIRLY STRONG SHORT WAVES STILL AFFECTING IL THIS MORNING AND TO
GIVE PARTLY TO MOSTLY CLOUDY SKIES WITH A CHANCE OF FLURRIES INTO
MID MORNING ESPECIALLY EAST CENTRAL IL ALONG WITH BRISK WNW WINDS.
1030 MB HIGH PRESSURE OVER EAST TX AND RIDGING NORTHWARD ACROSS
THE GREAT PLAINS WILL SHIFT EAST INTO THE MS VALLEY THIS AFTERNOON
DECREASING CLOUDS AND WINDS. COOL HIGHS FROM 32-38F WITH MILDEST
READINGS IN SE IL AND SW OF SPRINGFIELD.
HIGH PRESSURE DRIFTS EAST INTO THE CENTRAL APPALACHIANS OVERNIGHT
WHILE LOW PRESSURE EMERGES INTO THE NORTHERN PLAINS BY DAWN
SUNDAY. LOWS TONIGHT IN THE LOW TO MID 20S AND LIKELY REACHED BY
MIDNIGHT WITH NEARLY STEADY OVERNIGHT WITH SSE WINDS INCREASING TO
10-20 MPH BY SUNRISE SUNDAY.
LOW PRESSURE TRACKS EAST TOWARD UPPER MI BY MIDNIGHT SUNDAY NIGHT
WITH STRONG PRESSURE GRADIENT SETTING UP OVER IL AND STRONG SOUTH
WINDS WITH GUSTS 30 TO 40 MPH. HIGHS IN THE 30S TODAY JUMP UP INTO
THE 50S SUNDAY AFTERNOON WITH MOSTLY SUNNY SKIES. FRONTAL BOUNDARY
TO PRESS SE ACROSS CENTRAL IL BY OVERNIGHT SUNDAY NIGHT AND PASSES
THROUGH DRY WITH UPPER LEVEL DYNAMICS PASSING NORTH OVER THE GREAT
LAKES REGION AND DEEPER MOISTURE FROM THE GULF OF MEXICO CUT OFF
BY HIGH PRESSURE RIDGE FROM THE MID ATLANTIC STATES AND RIDGING
WSW ACROSS DIXIE.
MOSTLY SUNNY SKIES AGAIN MONDAY AND A BIT COOLER OVER CENTRAL IL
BEHIND THE FRONT WITH HIGHS RANGING FROM THE MID 40S NORTH OF
PEORIA AND MID 50S IN SE IL.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST AND MOST MODELS
CONTINUE DRY CONDITIONS MONDAY NIGHT AND THEN SPREAD RAIN SHOWERS
ACROSS IL DURING TUE AND ESPECIALLY TUE NIGHT. IL GETTING
ESTABLISHED IN A MORE SW UPPER LEVEL FLOW WITH TWO LOW PRESSURE
SYSTEMS DEEPENING NE INTO THE MIDWEST AND KEEPING IL ON THE MILDER
SIDE OF THE STORM TRACK. BEST CHANCES OF SHOWERS AND POSSIBLE
THUNDERSTORMS WILL BE TUE AFTERNOON AND TUE NIGHT. CENTRAL AND SE
IL GETS DRY SLOTTED DURING WED WITH BEST CHANCES OF PRECIPITATION
NORTH AND EAST OF CENTRAL IL. ANOTHER STRONG LOW PRESSURE QUICKLY
ON ITS HEALS AND DEEPENS INTO THE MIDWEST FRI AND FRI NIGHT WITH
NEXT CHANCE OF PRECIPITATION WHICH APPEARS TO BE MAINLY RAIN AGAIN
WITH LOW PRESSURE TRACK NORTH OF CENTRAL IL. KEEPING TEMPS ABOVE
NORMAL DURING NEXT WEEK AS WE HEAD INTO EARLY MARCH.
KH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 AM CST SAT FEB 25 2012
.AVIATION...
VFR CONDITIONS TO PREVAIL THROUGH 18Z/26TH. FEW-SCT STRATOCU WITH
MVFR BASES (2000-2500 FT AGL) WILL BE FOUND THROUGH MID AFTN
BEFORE DIMINISHING WITH LOSS OF HEATING. SFC RIDGE WILL PASS THIS
EVE WITH W/NW WINDS AROUND 10 KTS BECOMING NEAR CALM TO LIGHT
S/SW EARLY EVE BEFORE BACKING TO E/SE AND INCREASING 10-15 KTS WITH
GUSTS OVRNGT AS PRESSURE GRADIENT STRENGTHENS BETWEEN DEPARTING
SFC RIDGE AND LOW EMERGING INTO THE NORTHERN PLAINS. ADDED MENTION
OF LLWS AFT 06Z AS STRONG S/SW LOW LEVEL JET DEVELOPS... WITH NAM
AND GFS SOUNDINGS SHOWING 45-55 KTS DEVELOPING IN 1500-2000 FT AGL.
&&
.PREV DISCUSSION... /ISSUED 538 AM CST SAT FEB 25 2012/
UPDATE...
SATELLITE AND RADAR TRENDS SHOW FLURRIES CONTINUE BACK INTO
CENTRAL IOWA WITH A SOUTHEAST MOVEMENT. RUC TRENDS USING PRESSURE
ADVECTION ON THE 1.5PV SFC AND 500MB VORT MAX SHOW AN AREA OF LIFT
WHERE THE FLURRIES ARE CURRENTLY DEPICTED IN OBS/RADAR. THE RUC
DECREASES THE LIFT THROUGH THE MORNING AS THE VORT MAX MOVES EAST
ACROSS THE CWFA. THUS ISOLATED FLURRIES WILL BE SEEN THROUGH MID
MORNING OVER ROUGHLY THE WESTERN HALF WHILE FLURRIES CONTINUE OVER
THE EASTERN THIRD.
STRONG SUBSIDENCE BEHIND THE VORT MAX WILL ALLOW RAPID CLEARING OF
CLOUDS FROM WEST TO EAST DURING THE MORNING HOURS WITH A MAJORITY
OF THE CWFA BECOMING MOSTLY SUNNY BY MID DAY. DIURNAL CU/SC MAY
STILL FIRE AS THE COLD POCKET ALOFT MOVES INTO THE AREA.
AND UPDATE TO THE FCST WILL BE AVAILABLE SHORTLY. ..08..
PREV DISCUSSION... /ISSUED 308 AM CST SAT FEB 25 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL
WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW
POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS
AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA
SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT
MOVING THROUGH THE REGION.
SHORT TERM...TODAY AND TONIGHT...
RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE
AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO
BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN
WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY
AFTER SUNRISE.
WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC
TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER
MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW
LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD
DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL
IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS
ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION.
PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE
STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA.
SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK
UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A
COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW
DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA.
THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT
THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS
TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN
CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH.
TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS
TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW
BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF
AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE.
08..
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS
MOVE THROUGH THE REGION.
THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING
FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT
LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS
SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD
FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY
SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING
IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL
THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD
HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND
LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID
40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND
THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS
CONTINUED.
ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S.
MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT
CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE
THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH
THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER
SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE
DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD
PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING
WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE
REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN
WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF
THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING
THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE
LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS
MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH
MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION.
A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY
EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR
WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS
LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND
SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30
MPH.
YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST
WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE
GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST
AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR
EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED
ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS
SYSTEM. ..DLF..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
538 AM CST SAT FEB 25 2012
.UPDATE...
SATELLITE AND RADAR TRENDS SHOW FLURRIES CONTINUE BACK INTO
CENTRAL IOWA WITH A SOUTHEAST MOVEMENT. RUC TRENDS USING PRESSURE
ADVECTION ON THE 1.5PV SFC AND 500MB VORT MAX SHOW AN AREA OF LIFT
WHERE THE FLURRIES ARE CURRENTLY DEPICTED IN OBS/RADAR. THE RUC
DECREASES THE LIFT THROUGH THE MORNING AS THE VORT MAX MOVES EAST
ACROSS THE CWFA. THUS ISOLATED FLURRIES WILL BE SEEN THROUGH MID
MORNING OVER ROUGHLY THE WESTERN HALF WHILE FLURRIES CONTINUE OVER
THE EASTERN THIRD.
STRONG SUBSIDENCE BEHIND THE VORT MAX WILL ALLOW RAPID CLEARING OF
CLOUDS FROM WEST TO EAST DURING THE MORNING HOURS WITH A MAJORITY
OF THE CWFA BECOMING MOSTLY SUNNY BY MID DAY. DIURNAL CU/SC MAY
STILL FIRE AS THE COLD POCKET ALOFT MOVES INTO THE AREA.
AND UPDATE TO THE FCST WILL BE AVAILABLE SHORTLY.
..08..
&&
.AVIATION...
MVFR TO VFR CONDITIONS WITH FLURRIES WILL IMPROVE TO VFR BY
18Z/25. HIGH PRESSURE WILL MOVE ACRS THE AREA ALLOWING WINDS TO
DROP AND BECOMING SOUTHERLY BY 00Z/26. VFR CONDITIONS WILL
CONTINUE AFT 00Z/26 WITH HIGH LEVEL CLOUDS MOVING INTO THE AREA AS
SOUTHERLY RETURN FLOW STRENGTHENS.
..08..
&&
.PREV DISCUSSION... /ISSUED 308 AM CST SAT FEB 25 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL
WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW
POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS
AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA
SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT
MOVING THROUGH THE REGION.
SHORT TERM...TODAY AND TONIGHT...
RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE
AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO
BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN
WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY
AFTER SUNRISE.
WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC
TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER
MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW
LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD
DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL
IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS
ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION.
PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE
STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA.
SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK
UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A
COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW
DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA.
THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT
THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS
TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN
CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH.
TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS
TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW
BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF
AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE.
.08..
LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS
MOVE THROUGH THE REGION.
THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING
FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT
LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS
SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD
FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY
SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING
IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL
THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD
HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND
LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID
40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND
THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS
CONTINUED.
ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S.
MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT
CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE
THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH
THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER
SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE
DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD
PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING
WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE
REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN
WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF
THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING
THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE
LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS
MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH
MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION.
A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY
EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR
WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS
LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND
SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30
MPH.
YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST
WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE
GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST
AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR
EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED
ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS
SYSTEM. ..DLF..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
308 AM CST SAT FEB 25 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL
WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW
POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS
AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA
SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT
MOVING THROUGH THE REGION.
&&
.SHORT TERM...TODAY AND TONIGHT...
RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE
AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO
BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN
WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY
AFTER SUNRISE.
WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC
TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER
MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW
LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD
DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL
IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS
ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION.
PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE
STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA.
SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK
UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A
COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW
DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA.
THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT
THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS
TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN
CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH.
TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS
TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW
BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF
AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE.
..08..
.LONG TERM...SUNDAY THROUGH FRIDAY...
MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS
MOVE THROUGH THE REGION.
THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING
FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT
LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS
SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD
FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY
SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING
IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL
THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD
HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND
LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID
40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND
THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS
CONTINUED.
ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S.
MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT
CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE
THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH
THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER
SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE
DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD
PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING
WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE
REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN
WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF
THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING
THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE
LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS
MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH
MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION.
A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY
EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR
WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS
LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND
SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30
MPH.
YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST
WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE
GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST
AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR
EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED
ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS
SYSTEM. ..DLF..
&&
.AVIATION... /ISSUED 1129 PM CST FRI FEB 24 2012/
STRONG NORTHWEST FLOW OVER THE AREA BEHIND THE EXITING STORM
SYSTEM FROM LAST NIGHT. TERMINALS ARE CURRENTLY AFFECTED BY A
FIELD OF MID LEVEL VFR STRATOCUMULUS WITH FLURRIES...GENERALLY BETWEEN
3500 AND 5000 FT...WHICH IS EXPECTED TO REMAIN OVER THE AREA MOST
OF THE NIGHT. A WEAK DISTURBANCE IN THE FLOW NOW AFFECTING
CENTRAL IOWA SHOULD DROP SOUTHEAST AND MAY BRING SOME MVFR SNOW SHOWERS
TO KCID...KMLI AND KBRL...GENERALLY THROUGH 09Z. THIS WAVE PASSES
EAST OF THE TERMINALS AND ALLOW CLEARING TO OCCUR 12Z-18Z. NORTHWEST
WINDS TO REMAIN IN THE 10 TO 15 KTS RANGE OVERNIGHT...NOT
DIMINISHING TO LESS THAN 10KTS UNTIL ABOUT 17Z SATURDAY MORNING.
SATURDAY AFTERNOON WINDS TO TURN FROM NORTHWEST TO WEST...AND THEN
SOUTHWEST OR EVEN SOUTH BY 00Z...DEPENDING ON LOCATION. LIGHT
SOUTH TO SOUTHEAST WINDS TO LINGER 00-06Z/26TH. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
659 PM MST SUN FEB 26 2012
.UPDATE...
ISSUED AT 651 PM MST SUN FEB 26 2012
SFC HIGH NOW SETTLING OVER THE AREA AS WINDS HAVE RAPIDLY
DECREASED. 00Z SOUNDINGS INDICATE DRY AIR MASS IN PLACE AT DNR AND
TO A LESSER EXTENT DDC...WITH LOW LEVEL MIXING RATIOS NOTICEABLY
HIGHER AT KLBF. WITH THESE OBSERVATIONS AND EXPECTED WIND
FIELD...STILL EXPECT A FAIRLY SHARP NORTHEAST TO SOUTHWEST TD
GRADIENT THROUGH THE EVENING...ALTHOUGH THERE WILL BE SOME
RECOVERY WITH LOSS OF DEEP MIXING. WHILE THINGS WILL BE SLIGHTLY
MORE HUMID...MOISTURE PROFILES DO NOT LOOK DEEP ENOUGH TO PREVENT
TEMPS FROM DROPPING SHARPLY GIVEN LIGHT WINDS...DRY AIR AND
MINIMAL HIGH CLOUD COVER. HAVE LOWERED TEMPS 4-5 DEGREES AT
SEVERAL LOCATIONS...ESPECIALLY NORMAL COLD SPOTS LIKE WESTERN
CHEYENNE COUNTY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 236 PM MST SUN FEB 26 2012
LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN
UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL
JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE
OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE
STRONGER WINDS ABOVE THE SURFACE MIX DOWN.
THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE
AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING
THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH
NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE
OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS
SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE
SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH.
WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE
COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST
NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS.
MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST
EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY
MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN
THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE
BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I
DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED
TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST
CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE
WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING
AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT
PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX
COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS
ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD
KEEP CONDITIONS BELOW ADVISORY LEVELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 PM MST SUN FEB 26 2012
TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE
INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY.
GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING
UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY
PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY
WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE
TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH
GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA.
STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE
SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING
CRITERIA WINDS (GUSTS 60MPH OR GREATER).
WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION
WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS
CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE
REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED
OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF
THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH
TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND
SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL
BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD
TEMPERATURES RETURNING TO THE CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 406 PM MST SUN FEB 26 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL SUBSIDE
EARLY IN THE PERIOD AS DAYTIME MIXING ENDS...AND WINDS WILL BE
LESS THAN 10 KNOTS FOR MOST OF THE NIGHT. THESE LIGHT WINDS SHOULD
REMAIN FROM THE NORTHWEST DURING THE EVENING...BUT THEY WILL
BECOME MORE VARIABLE DURING THE EARLY MORNING HOURS BEFORE
BECOMING SOUTHEASTERLY. THESE SOUTHEASTERLY WINDS WILL INCREASE
AND BEGIN GUSTING AGAIN AS MIXING INCREASES AFTER SUNRISE...AND
WINDS WILL TAKE ON MORE OF A SOUTHERLY COMPONENT BY 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JTL/DR
LONG TERM....DR
AVIATION...CJS
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
527 PM CST SUN FEB 26 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT RANGE FORECAST - TONIGHT AND MONDAY...
CLEAR SKIES AND W-NW DOWNSLOPE WINDS HAVE ALLOWED SURFACE
TEMPERATURES TO RISE INTO THE UPPER 50S TO MID 60S ACROSS MOST OF
NORTHEAST KANSAS. EXPECT THE WARM AND DRY CONDITIONS TO PERSIST FOR
THE REST OF THE AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO THE
NORTHERN PLAINS AND NOSE INTO THE FORECAST AREA BRINGING CLEAR SKIES
OVERNIGHT WITH CALM WINDS. DO NOT EXPECT MUCH IN THE WAY OF COLD AIR
ADVECTION...BUT RADIATIONAL COOLING WILL ALLOW THE BOUNDARY LAYER TO
COOL TO BELOW FREEZING.
EXPECT SOME COLD AIR ADVECTION TO TRICKLE INTO THE AREA BEHIND THE
VERY LIGHT NORTHERLY FLOW FOR MONDAY. MIXING NOT QUITE AS DEEP ON
MONDAY AS SUNDAY...SO THAT FACTOR IN COMBINATION WITH THE WEAK COLD
AIR ADVECTION WILL KEEP TEMPS ON MONDAY MORE SEASONAL. CLOUDS WILL
BE ON THE INCREASE BY MONDAY AFTERNOON/EVENING AS WARM/MOIST AIR
GETS ADVECTED NORTHWARD. CONDENSATION AS A RESULT OF THE ISENTROPIC
LIFT ASSOCIATED WITH THE WARM AIR ADVECTION WILL LIKELY BEGIN
SHORTLY AFTER NOON...WHICH WILL ALSO AID IN KEEPING TEMPERATURES
FROM RISING MUCH HIGHER THAN THE LOWER 50S.
JL
LEIGHTON
LONG TERM - MONDAY NIGHT THROUGH SUNDAY...
MONDAY NIGHT THROUGH TUESDAY NIGHT...
MODEL AGREEMENT IS NOW FAIRLY GOOD IN THE TRACK OF A POTENT
NEGATIVELY TILTED UPPER LEVEL TROUGH. THE SURFACE LOW WILL TRACK
WELL NORTH OF THE LOCAL FORECAST AREA WITH A SHARP FAST MOVING DRY
LINE CROSSING THE AREA BETWEEN 21Z TUESDAY AND 03Z WEDNESDAY.
WARM MOIST ADVECTION WILL TAKE PLACE ON MONDAY NIGHT AND TUESDAY
MORNING AHEAD OF THE SYSTEM WITH SHOWERS AND A FEW ELEVATED
THUNDERSTORMS EXPECTED TO DEVELOP AND MOVE INTO THE AREA MONDAY
NIGHT. THIS ACTIVITY SHOULD ALL REMAIN BELOW SEVERE LIMITS WITH
SOME LOW END POTENTIAL FOR SMALL HAIL THROUGH NOON ON TUESDAY.
WHILE CLOUD COVER WILL BE ABUNDANT THROUGH THE DAY ON TUESDAY...
TEMPERATURES WILL WARM NICELY WITH AMPLE WARM ADVECTION. THE CLOUD
LAYER WILL ALSO BE RELATIVELY SHALLOW AND LOW BY TUESDAY
AFTERNOON...AND A FEW BREAKS WILL BE POSSIBLE AHEAD OF THE DRY
LINE BY LATE AFTERNOON. SURFACE DEWPOINTS WILL CLIMB INTO THE MID
50S BY LATE TUESDAY ACROSS MUCH OF THE FORECAST AREA WITH TEMPS IN
THE UPPER 50S AND LOW 60S. EXPECT THE DRY LINE TO ENTER THE
FORECAST AREA SOMETIME BETWEEN 21Z AND 00Z...AND PUSH EAST INTO
MISSOURI ONLY 3 TO 4 HOURS LATER. CONVECTION IS EXPECTED TO
DEVELOP IMMEDIATELY ALONG THE DRY LINE BOUNDARY BY LATE AFTERNOON
AND CROSS THE FORECAST AREA...BUT SUBSTANTIAL UNCERTAINTY EXISTS
REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS.
CURRENT INDICATIONS ARE THAT 200-500 J/KG OF SURFACE BASED CAPE
WILL BE PRESENT IN A NARROW BAND NEAR THE BOUNDARY. THOSE ARE
MEAGER VALUES BUT THE MAJORITY OF THIS INSTABILITY WILL BE IN THE
LOWEST 15000 FEET OF THE ATMOSPHERE WITH MAX LIFTED INDEX VALUES
IN THAT LAYER APPROACHING -5. THIS WOULD SUGGEST THE POTENTIAL FOR
SOME STRONGER SHALLOW UPDRAFTS. SHEAR THROUGH THE DEPTH OF THE
CONVECTIVE LAYER...ABOUT 0-4 KM...IS 50-60 KTS WHILE 0-1 KM SHEAR
IS 30-40 KTS. THESE VALUES ARE MORE THAN SUFFICIENT TO PRODUCE
ORGANIZED STORMS WITH SOME POTENTIAL FOR LOW TOPPED SUPERCELL
DEVELOPMENT. HOWEVER...THE UNIDIRECTIONAL NATURE OF THE SHEAR MAY
SUGGEST MORE OF A QUASI-LINEAR DEVELOPMENT WITH A BIT MORE
POTENTIAL FOR DAMAGING WINDS AT THE SURFACE. IT WILL BE DIFFICULT
TO GET LARGE HAIL WITH SUCH SHALLOW UPDRAFTS PERHAPS HAVING
TROUBLE CLIMBING ABOVE THE -20C LEVEL...BUT AT LEAST SMALL HAIL
WOULD REMAIN POSSIBLE. TORNADO POTENTIAL IS NON-ZERO...BUT HIGHLY
DEPENDENT UPON DEVELOPMENT OF MORE ROBUST UPDRAFTS...AND STRONG
UPDRAFT POTENTIAL IS THE MOST SIGNIFICANT UNCERTAINTY WITH THIS
FORECAST.
WEDNESDAY THROUGH SUNDAY...
WILL DRY OUT QUICKLY BEHIND THIS SYSTEM AND REMAIN DRY WITH A
SLIGHT COOL DOWN FOR WEDNESDAY AND A QUICK RECOVERY WITH WARM
TEMPS AGAIN ON THURSDAY. A WEAKER STORM SYSTEM WILL THEN CROSS THE
PLAINS THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM DOES NOT HAVE A
PARTICULARLY STRONG PRECIP SIGNAL BUT APPEARS WORTHY OF AT LEAST A
SLIGHT CHANCE OF LIGHT RAIN WITH PERHAPS A MIX TO LIGHT SNOW
THURSDAY NIGHT. IT DOES NOT APPEAR TO BE A HIGH IMPACT EVENT AT
THIS TIME. EXPECT DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR
SATURDAY AND SUNDAY.
BARJENBRUCH
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH THE TERMINAL FCST PERIOD
WITH ONLY SCT HIGH CLOUDS EXPECTED. LIGHT NORTHWEST WINDS THIS
EVENING WILL BECOME NORTHEAST 6-10KTS BY 09Z AND THEN CONTINUE THE
REMAINDER OF THE FORECAST.
&&
.FIRE WEATHER...
DEEP MIXING HAS COMMENCED ACROSS ALL OF NORTHEAST KANSAS BRINGING
VERY DRY LOW LEVEL AIR TO THE SURFACE. RUC SOUNDINGS INDICATE THAT
THE ATMOSPHERE HAS MIXED TO APPROXIMATELY 800 MB OR 5600 FEET. W-NW
WINDS AT THE SURFACE CONTAIN QUITE A BIT OF A DOWNSLOPE TRAJECTORY
WHICH HAS AIDED IN WARMING AND DRYING THE AIR. AS A RESULT RELATIVE
HUMIDITY VALUES HAVE DROPPED INTO THE MID TEENS THIS AFTERNOON...AND
WILL LIKELY REMAIN IN THE MIDDLE TEENS THROUGH AT LEAST SUNSET.
WINDS THROUGHOUT THE DAY HAVE BEEN RELATIVELY LIGHT AS OBSERVATIONS
HAVE INDICATED 10 TO 15 MPH W-NW WINDS. DUE TO THE DEEP MIXING SOME
WIND GUSTS OF UP TO 20-25 MPH ARE POSSIBLE...BUT THOSE GUSTS WILL BE
RATHER INFREQUENT. RH VALUES WILL START TO RISE ONCE SURFACE
TEMPERATURES BEGIN TO COOL RIGHT AROUND SUNSET.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ008>012-
020>024-026-034>040.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
406 PM MST SUN FEB 26 2012
.UPDATE...
ISSUED AT 335 PM MST SUN FEB 26 2012
OBSERVATIONS ALONG AND NORTH OF HIGHWAY 24 SHOW THAT THE WIND
GUSTS HAVE BEEN BELOW CRITERIA FOR A COUPLE OF HOURS...WITH SPEEDS
OF 30 TO 35 MPH COMMON. AM EXPECTING THE WINDS TO CONTINUE TO
DECLINE SO WILL GO AHEAD AND CANCEL THE WIND ADVISORY.
RED FLAG CONDITIONS ARE STILL BEING REPORTED ACROSS THE TRI-STATE
AREA SO WILL LET THE RED FLAG WARNING CONTINUE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 236 PM MST SUN FEB 26 2012
LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN
UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET
OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS
REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS
ABOVE THE SURFACE MIX DOWN.
THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE
AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING
THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH
NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE
OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS
SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE
SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH.
WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE
COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST
NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS.
MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST
EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY
MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN
THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE
BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I
DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED
TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST
CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE
WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING
AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT
PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX
COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS
ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD
KEEP CONDITIONS BELOW ADVISORY LEVELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 PM MST SUN FEB 26 2012
TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE
INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY.
GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING
UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY
PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY
WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE
TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH
GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA.
STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE
SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING
CRITERIA WINDS (GUSTS 60MPH OR GREATER).
WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION
WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS
CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE
REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED
OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF
THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH
TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND
SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL
BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD
TEMPERATURES RETURNING TO THE CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 406 PM MST SUN FEB 26 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL SUBSIDE
EARLY IN THE PERIOD AS DAYTIME MIXING ENDS...AND WINDS WILL BE
LESS THAN 10 KNOTS FOR MOST OF THE NIGHT. THESE LIGHT WINDS SHOULD
REMAIN FROM THE NORTHWEST DURING THE EVENING...BUT THEY WILL
BECOME MORE VARIABLE DURING THE EARLY MORNING HOURS BEFORE
BECOMING SOUTHEASTERLY. THESE SOUTHEASTERLY WINDS WILL INCREASE
AND BEGIN GUSTING AGAIN AS MIXING INCREASES AFTER SUNRISE...AND
WINDS WILL TAKE ON MORE OF A SOUTHERLY COMPONENT BY 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254.
KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
&&
$$
UPDATE...JTL
SHORT TERM...JTL/DR
LONG TERM....DR
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1248 AM EST SAT FEB 25 2012
.SYNOPSIS...
LOW PRESSURE WILL INTENSIFY AS IT TRACKS THROUGH THE GULF OF MAINE
LATE TONIGHT. THIS STRONG LOW PRESSURE WILL CONTINUE NORTHEAST
THROUGH THE MARITIMES SATURDAY INTO SATURDAY NIGHT. HIGH PRESSURE
WILL BUILD IN LATER SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE 3: ONLY CHG WAS TO INCLUDE LATEST OBSVD SFC TEMPS FOR
05-06Z TM FRAME. OTHERWISE...STORM IS UNDERWAY WITH INCREASING SN
ECHOES SPREADING OVR THE FA ATTM OF THIS UPDATE. NO CHGS TO BE
MADE TO THE CURRENT FCST ATTM...AS WE MONITORED RADAR ESTIMATES OF
SNFL ACROSS THE FA OVR THE NEXT SEVERAL HRS.
UPDATE 2: HRRR MODEL AND THIS EVENINGS RUN OF THE NAM STILL
INDICATING SNOW AMOUNTS OF 10 TO 14 INCHES ACROSS MOST OF NORTHERN
AND CENTRAL SECTIONS. HAVE ADDED HEAVY SNOW TO THE FORECAST FOR
ALL OF CENTRAL AND NORTHERN ZONES WITH SNOW RATES BETWEEN 1 AND 2
INCHES FROM MIDNIGHT TO DAYBREAK SATURDAY. MODELS INDICATING SNOW
TO END EARLY SATURDAY MORNING AS LOW MOVES RAPIDLY EAST OF THE
REGION.
UPDATE 1: HRRR AND OTHER MODEL WINDS INDICATING SOUTHEAST WINDS TO
INCREASE ACROSS COASTAL SECTIONS AROUND MIDNIGHT AS LOW LEVEL JET
DEVELOPS IN ADVANCE OF LOW MOVING THROUGH THE GULF OF MAINE. WILL
MOVE WIND ADVISORY UP TO MIDNIGHT OTHERWISE NO OTHER CHANGES
NEEDED AT THIS TIME.
ORGNL DISC: AN INTERESTING STORM SETTING UP FOR THE CWA.
LOW PRES IS MOVING ACROSS THE EASTERN GREAT LAKES ATTM AND THEN IS
FCST TO REDEVELOP ALONG THE NEW ENGLAND COAST AND THEN RAPIDLY
MOVE NE ACROSS EASTERN MAINE BY SATURDAY MORNING. TREMENDOUS MID
LEVEL FORCING SETTING UP FROM 00-06Z ACROSS THE SOUTHERN AREAS AND
THEN THIS FORCING LIFT NE OVERNIGHT INTO NORTHERN AND EASTERN
AREAS. 1000-700MB FRONTOGENETICAL FORCING IS THE STRONGEST WE HAVE
SEEN THIS SEASON SO FAR AND GIVEN STRONG THERMAL GRADIENT IN THE
LLVLS, WE ARE EXPECTING A PERIOD OF HEAVY PRECIP. TEMPERATURES
WILL BE WARM ENOUGH INITIALLY ACROSS THE SOUTHERN AREAS SUCH AS
BANGOR AND EVEN DOVER-FOXCROFT FOR RAIN BUT AS DYNAMIC COOLING
TAKES HOLD, THE PRECIP WILL CHANGE TO SNOW WHICH WILL BE HEAVY AT
TIMES LATER THIS EVENING INTO THE OVERNIGHT PERIOD. WE COULD VERY
WELL SEE UP TO 2 INCHES/HR WHICH WILL LEAD TO HEFTY SNOWFALL
AMOUNTS UP THROUGH 06Z. THE BANGOR REGION SHOULD SEE TEMPERATURES
TO REMAIN ABOVE 32F OVERNIGHT AND AS THE FORCING LETS UP
OVERNIGHT, SNOWFALL WILL BE MORE OF A LIGHT TO MODERATE NATURE.
THIS COMBINED W/THE MILD SFC TEMPERATURES WILL ALLOW FOR SETTLING
AND EVEN SOME MELTING. RAIN AND EVEN SLEET WILL MIX IN FOR A TIME
IF NOT EVEN GO OVER TO RAIN BEFORE GOING BACK TO SNOW BY SATURDAY
MORNING. THEREFORE, STAYED W/A WINTER WEATHER ADVISORY BUT BEEFED
UP SNOWFALL TOTALS FOR THE BANGOR AND CALAIS REGIONS TO 5 TO 8
INCHES OVER A 12-18 HR PERIOD. THIS WILL NEED TO MONITORED BY THE
EVENING CREW ESPECIALLY IF THE LOW TRACKS FURTHER S OVER THE
WATERS ALLOWING FOR COLDER AIR TO SETTLE IN LEADING TO HIGHER
SNOWFALL TOTALS.
ON THE COAST, THINKING HERE IS THAT ENOUGH WARMER AIR COMING IN
FROM THE GULF OF MAINE WATERS WILL ALLOW FOR ANY FROZEN PRECIP TO
GO TO RAIN, WHICH COULD BE HEAVY AT TIMES. ATTM, WE KEPT SNOWFALL
AMOUNTS DOWN TO NO MORE THAN AN INCH OR 2. WINDS APPEAR TO BE MORE
OF A CONCERN AS A LLVL JET OF 55 KTS MOVES ALONG THE COAST FROM
ABOUT 09-18Z SATURDAY. WINDS WILL BE SSW WHICH HISTORICALLY TENDS
TO STAY ALOFT AS THE WARMER AIR OVERRIDES THE COOLER SFC. A WIND
ADVISORY IS UP AS GUSTS OF 50 MPH ARE POSSIBLE. THIS IS SUPPORTED
BY THE BUFKIT PROFILES SHOWING A GOOD ALIGNMENT FROM THE SFC UP
THROUGH ABOUT 3K FT OF 45-50KT.
ACROSS THE NORTHERN AND CENTRAL AREAS, MORE SNOWFALL LOOKS TO BE
IN ORDER AS THE COLUMN WILL BE COLD ENOUGH TO SUPPORT ALL SNOW AND
W/A GOOD PERIOD OF SNOWFALL RATES OF UP TO 2 INCHES/HR FROM
06-12Z, AMOUNTS OF UP TO 10+ INCHES ARE POSSIBLE BY 12Z SATURDAY
ESPECIALLY ACROSS AROOSTOOK COUNTY AND PORTIONS OF PISCATAQUIS AND
NORTHERN PENOBSCOT COUNTIES. WINTER STORM WARNINGS REMAIN IN PLACE
IN THESE AREAS. THINGS WILL WIND DOWN BY MIDDAY SATURDAY AS THE
LOW EXITS INTO NEW BRUNSWICK W/A STEADY LIGHT SNOWFALL MAINLY
ACROSS NORTHERN AREAS. WNW WINDS WILL INCREASE BEHIND THE SYSTEM
LEADING TO BLOWING AND DRIFTING SNOW. THIS WILL NEED TO BE
ADDRESSED BY THE LATER CREWS.
A POSSIBLE SURGE IS POSSIBLE COMING UP THE PENOBSCOT OVERNIGHT
INTO THE BANGOR REGION W/A SSE WIND OF 25+MPH. ATTM, IT APPEARS
THAT THE TIME FRAME IS TOO SHORT OF DURATION AND QPF NOT HIGH
ENOUGH TO CAUSE SIGNIFICANT PROBLEMS. THE EVENING AND MIDNIGHT
CREW NEED TO KEEP AN EYE ON THIS AS HIGH TIDE IS LATER TONIGHT AT
05-06Z TIME FRAME.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
STRONG LOW PRESSURE WILL BE MOVING AWAY TO THE NORTHEAST SATURDAY
AFTERNOON. SNOW SHOWERS WILL CONTINUE OVER THE NORTH AND STRONG
GUSTY WINDS FOLLOWING THE SYSTEM WILL BUFFET THE REGION WITH GUSTY
WINDS. BLOWING AND DRIFTING SNOW WILL AFFECT CENTRAL AND NORTHERN
AREAS. COLD ADVECTION SATURDAY NIGHT INTO SUNDAY COMBINED WITH THE
TIGHT GRADIENT WILL CAUSE SOME BLOWING AND DRIFTING TO
CONTINUE...MAINLY ACROSS ROADWAYS WITH OPEN EXPOSURE TO THE WEST.
WINDS WILL THEN SUBSIDE SUNDAY NIGHT AS HIGH PRESSURE BUILDS OVER
AND TEMPS DROP BELOW ZERO NORTH AND INTO THE SINGLE DIGITS
DOWNEAST. A WEAK SHORTWAVE APPROACHING ON MONDAY WILL THEN BRING
CLOUDS AND THE CHANCE FOR SOME SNOW SHOWERS OR PATCHY LIGHT SNOW
ACROSS THE AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AT THE START OF THE LONG TERM BOTH MODELS ARE SHOWING A HIGH
PRESSURE RIDGE EXTENDED ACROSS THE REGION...A WEAK LOW OVER SRN
QUEBEC. BY TUESDAY MORNING THE LOW WILL MOVE EAST OF THE AREA TO
SRN NOVA SCOTIA. HIGHER PRESSURE WILL BUILD BACK INTO THE AREA. BY
TUESDAY EVENING THE HIGH PRESSURE RIDGE IS BUILT BACK ACROSS THE
REGION. A NEW LOW IS MOVING INTO THE CENTRAL PLAINS. BY WEDNESDAY
MORNING THE NEW LOW IS INTO THE WRN GREAT LAKES. WITH AN OCCLUDED
SYSTEM WRAPPED AROUND IT. BY WEDNESDAY EVENING THE LOW WILL MOVE
INTO THE CENTRAL GREAT LAKES REGION. THE OCCLUDED SYSTEM WILL MOVE
INTO NH/ME. BY THURSDAY MORNING THE MODELS ARE SHOWING 2NDRY
DEVELOPMENT ALONG THE GULF OF MAINE. THE GFS HAS THE 2NDRY LOW
OVER SRN NOVA SCOTIA...A NEW LOW OVER NRN NE...THE ECMWF HAS IT
OVER CAPE COD. THE GFS HAS THE PARENT LOW SOUTH OF JAMES BAY. THE
ECMWF HAS IT OVER LAKE HURON. BY THURSDAY EVENING THE GFS MOVES
THE PARENT LOW THROUGH MAINE INTO ERN NEW BRUNSWICK...THE NEW LOW
TO NRN IL...THE ECMWF MOVES THE PARENT LOW TO SRN
QUEBEC...MAINTAINS THE LOW S OF NOVA SCOTIA...AND SHOWS A NEW LOW
OVER NRN MO. BY FRIDAY MORNING THE GFS SHOWS A WEAK HIGH PRESSURE
RIDGE BUILT ACROSS ME...WITH THE NEW LOW MOVING EAST TO LAKE
HURON. THE ECMWF MOVES THE PARENT LOW TO ERN NOVA SCOTIA...MOVES
THE NEW LOW TO NRN IL/IN. BY FRIDAY EVENING THE GFS MOVES THE NEW
LOW TO SRN QUEBEC...THE ECMWF FILLS THE NEW LOW AND MAINTAINS THE
HIGH RIDGE ACROSS ME. BOTH MODELS ARE SHOWING DEVELOPMENT ALONG
THE GULF OF MEXICO. AND BY THE END OF THE PERIOD. THE GFS MOVE A
NEW LOW OFF THE EAST COAST EAST OF DELMARVA DEVELOPS A FRONTAL
SYSTEM FROM THIS LOW THROUGH NEW BRUNSWICK WRAPPED INTO THE LOW
OVER SRN QUEBEC. THE ECMWF DEVELOPS THE LOW ALONG THE GULF COAST
AND MOVES IT NORTH INTO WV...MAINTAINS THE HIGH PRESSURE RIDGE
ACROSS ME. SO THE GFS AND ECMWF WERE IN GOOD GENERAL AGREEMENT
THROUGH WEDNESDAY.
LOADED GMOS...ADJUSTED THE SKY AND POP GRIDS TO BETTER SUPPORT
ONE ANOTHER. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. PLUS
15 PERCENT FOR WIND GUSTS OVER LAND...20 PERCENT OVER WATER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR DROPPING TO MVFR THIS EVENING AND THEN RIGHT DOWN
TO IFR/LIFR THROUGH EARLY SATURDAY. LLWS COULD BE A CONCERN FOR
KBHB OVERNIGHT W/WINDS OF 45 KTS JUST ABOVE 800 FT.
SHORT TERM: STRONG GUSTY WINDS ARE EXPECTED ACROSS THE AREA THIS
WEEKEND. IFR TO MVFR CONDITIONS ARE EXPECTED OVER THE NORTH ON
SATURDAY WITH MVFR TO VFR CONDITIONS DOWNEAST. MVFR CONDITIONS
ARE EXPECTED OVER THE NORTH SATURDAY NIGHT WITH VFR CONDITIONS
DOWNEAST. VFR CONDITIONS ARE EXPECTED SUNDAY INTO MONDAY.
&&
.MARINE...
NEAR TERM:
UPDATE:HRRR AND OTHER MODEL WINDS INDICATING SOUTHEAST WINDS TO
INCREASE ACROSS THE WATERS AROUND MIDNIGHT AS LOW LEVEL JET
DEVELOPS IN ADVANCE OF LOW MOVING THROUGH THE GULF OF MAINE. WILL
MOVE GALE UP TO MIDNIGHT OTHERWISE NO OTHER CHANGES NEEDED AT THIS
TIME.
THE GALE WARNING REMAINS UP. WINDS WERE INCREASED TO SUSTAINED 35
KTS W/GUSTS HITTING 45 KTS. A FEW GUSTS TO STORM FORCE(47KT) ARE
POSSIBLE EARLY SATURDAY ESPECIALLY ACROSS THE OUTER WATERS BUT THE
TIME FRAME LOOKS TO BE SHORT LIVED. WAVE HEIGHTS WERE RAISED IN
REGARDS TO THE INCREASING WINDS GOING W/SEAS OF 10 -14 FT BY
SATURDAY.
SHORT TERM: A GALE WARNING IS EXPECTED FOR STRONG GUSTY WEST
WINDS SATURDAY INTO SUNDAY. WINDS WILL DIMINISH SUNDAY NIGHT AS
HIGH PRESSURE BUILDS OVER.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL NOON EST TODAY FOR MEZ001>004.
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MEZ005-
006-010-011-031-032.
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MEZ015>017.
WIND ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MEZ029-030.
MARINE...GALE WARNING UNTIL 5 PM EST SUNDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...BLOOMER
LONG TERM...NORTON
AVIATION...VJN
MARINE...VJN/BLOOMER
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1011 AM EST SAT FEB 25 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS INTO THE AREA FOR THE WEEKEND. THE HIGH WILL
MOVE OFF THE COAST SUNDAY NIGHT. A COLD FRONT WILL MOVE THROUGH
THE MID-ATLANTIC MONDAY...FOLLOWED BY HIGH PRESSURE TUESDAY. A
STORM SYSTEM MAY IMPACT THE AREA DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH THIS AFTERNOON/...
15Z SFC ANALYSIS SHOWS A STRONG 969 LOW NEAR THE BAY OF FUNDY. A
TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND A 1028 HIGH OVER THE
MIDWEST EXISTS OVER THE MID-ATLANTIC REGION TDA. LOOKING AT THE
12Z IAD SOUNDING AND FCST RUC SOUNDINGS...STEEP LAPSE RATES IN THE
LOWEST 9 KFT SHOULD STEEPEN FURTHER WITH SFC HEATING...WHICH WILL
RESULT IN EFFICIENT MIXING OF HIGHER WIND GUSTS DOWN TO THE SFC.
LATEST RUC/NAM MOMENTUM TRANSFER IN BUKFIT SHOWS LLVL WINDS WILL
ONLY BE MARGINAL TO SUPPORT WIND ADVISORY CRITERIA OF 45-50 MPH
GUSTS. ADVISORY-LVL WIND GUSTS WILL LIKELY BE MORE ISOLATED IN
NATURE...BUT CLOSE ENOUGH TO CONTINUE THE ADVISORY.
BANDS OF SNOW SHOWERS STREAMING IN FROM THE GREAT LAKES WILL
CONTINUE TO IMPACT THE WEST-FACING SLOPES OF THE ALLEGHENY AND
POTOMAC HIGHLANDS THRUOUT THE DAY. HAVE ADDED WRN ALLEGANY AND WRN
HIGHLAND COUNTY IN THE WINTER WX ADVISORY. WE HAVE ALREADY HAD
REPORTS OF 1-2 INCHES OF SNOW IN THESE AREAS...WITH AN ADDITIONAL
2-3 INCHES LIKELY DURING THE DAY TDA. SNOW SHOWER ACTIVIYY WAS
ABLE TO BRIEFLY REACH AREAS AS FAR EAST AS DC EARLIER THIS MRNG.
WITH THE APPROACH OF A THE UPPER-LEVEL TROUGH AND SUCH STEEP LAPSE
RATES SUPPORTING WEAK INSTABILITY...DO NOT SEE A REASON WHY ISO TO
SCT RA/SN SHOWER ACTIVITY CANT CONTINUE ACROSS THE AREA. SNOW
ACCUMULATION IS NOT EXPECTED DUE TO THE SHORT DURATION OF ANY
SHOWER AND ABOVE FREEZING SFC TEMPS.
SHOWER ACTIVITY WILL ALSO MAKE CLOUD AND TEMPS FCST TRICKY. WHILE
MOST OF THE REGION EAST OF THE HIGHLANDS WILL BE MSTLY SUNNY
TDA...SKIES WILL BECOME CLOUDY WITH THE PASSAGE OF A BRIEF SHOWER.
ALSO...EVAPORATIVE COOLING WILL CAUSE TEMPS TO DROP SEVERAL
DEGREES IN SHOWERS. CURRENT FCST REFLECTS MAX TEMPS RANGING FROM
AROUND 30F ALONG THE ALLEGHENY FRONT TO NEAR 50F IN THE NRN
PIEDMONT AND LWR SRN MD.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
SNOW OVER THE POTOMAC HIGHLANDS WILL TAPER OFF THIS EVENING AS
HIGH PRESSURE APPROACHES THE APPALACHIANS.
WINDS ARE EXPECTED TO DIMINISH THIS EVENING AND OVERNIGHT. GUSTS ARE
POSSIBLE WELL INTO THE EVENING IF A LOW LEVEL INVERSION IS SLOW TO
DEVELOP. AS LONG AS DECOUPLING TAKES PLACE OVERNIGHT...GOOD
RADIATIONAL COOLING CONDITIONS WILL HELP LOWS DROP INTO THE 20S
OVER MOST OF THE CWA...EXCEPT OVER URBAN BALTIMORE/WASHINGTON DC
WHICH SHOULD MANAGE TO STAY AROUND 30.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE FIRST HALF OF THIS COMING WEEK WILL BE FAIRLY QUIET. A WEAK LOW
PRESSURE SYSTEM WILL SWING BY TO THE NORTH IN THE MIDDLE OF THE
3-DAY STRETCH. SUNDAY WILL BE THE FIRST OF THESE DAYS INFLUENCED BY
A LARGE SFC HIGH. A COMPACT LOW PRESSURE SYSTEM WILL SLIDE EWD
ACROSS THE GREAT LAKES/NEW ENGLAND ON MONDAY...BOUNCING THE HIGH
TEMPORARILY AWAY FROM THE AREA BUT STILL KEEPING MID-ATLC WX
RELATIVELY WARM AND QUIET. ANOTHER SEASONAL DAY ON TUE. SUNDAY WILL
BE RELATIVELY COOL...AS TEMPS STRUGGLE TO REACH THE U40S BY MID
AFTN. HIGHS MON-WED WILL PEAK IN THE L60S ACROSS THE SRN HALF OF THE
AREA...W/ U50S ACROSS THE NRN HALF.
CHANGES WILL ARRIVE BY THE MIDDLE OF THE WEEK HOWEVER...AS A STABLE
PATTERN OF WAVE AFTER WAVE OF LOW PRESSURE SYSTEMS MOVE ACROSS THE
CONUS. EACH OF THE NEXT COUPLE OF SYSTEMS WILL MOVE DUE EAST ALONG
THE JET STREAM WHICH IS ROUGHLY PARKED OVER SRN CANADA. THE MONDAY
LOW PRESSURE SYSTEM WILL BE A WEAK CLIPPER PASSING JUST NORTH OF THE
AREA...BUT THE SUBSEQUENT SYSTEMS TOWARD THE MIDDLE AND LATTER PARTS
OF THE WEEK WILL BE MUCH MORE POTENT. THE NEXT FEATURE WILL BE
CUT-OFF UPPER LOW THAT DIGS INTO THE WRN HALF OF THE US...EVENTUALLY
MOVING INTO THE PLAINS AND GAINING STRENGTH. TUE INTO WED...THIS
INTENSE AND LARGE SCALE SYSTEM WILL TRUDGE ACROSS THE PLAINS AND
INTO THE GREAT LAKES/OHIO VLY. BY EARLY WED...PERIODS OF RAIN WILL
MOVE ACROSS THE MID-ATLC. CONVECTIVE CHANCES LOOK BEST JUST SOUTH OF
THE AREA ATTM...THOUGH TODAY/S ACTIVITY WAS EVIDENCE THAT THE
CONVECTIVE REGION COULD CERTAINLY AFFECT A PORTION OF THE CWA
/ESPECIALLY THE SRN TIER/ IF THE SYSTEM WERE TO MOVE A BIT FURTHER
NORTH THAN THE LATEST GUIDANCE SUGGESTS. THIS ACTIVITY IS EXPECTED
TO END BY EARLY THU.
A BRIEF BREAK THU/FRI BEFORE ANOTHER UPPER WAVE DIGS DOWN INTO THE
PLAINS AND DEVELOPS ANOTHER POTENT AND FAR-REACHING LOW PRESSURE
SYSTEM /FROM THE GULF TO THE GREAT LAKES/...MOVING OVER OUR AREA FRI
NIGHT INTO THE WEEKEND.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
MAINLY VFR CONDITIONS TDA. HOWEVER...A BRIEF RA/SN SHOWER COULD
IMPACT THE TERMINALS LATE THIS MRNG AND ERY AFTN. COVERAGE WILL BE
TOO LOW TO INCLUDE IN 15Z TAFS. MAIN IMPACT TDA WILL BE GUSTY WLY
WINDS SUSTAINED BETWEEN 15-25 KT...GUSTING 35-40 KT THRU THE AFTN.
WINDS DIMINISH GRADUALLY TONIGHT...BUT GUSTS 20-30 KT MAY CONTINUE
THROUGH THE EVENING HOURS.
HIGH PRESSURE WILL LARGELY HOLD FAIR CONDITIONS OVER THE REGION
SUN-TUE NIGHT. A COLD FRONT W/ PERIODS OF RAIN WILL MOVE THRU THE
AREA ON WED...MOVING OFF THE COAST WED NIGHT. ANOTHER QUIET COUPLE
OF DAYS...THEN ANOTHER COLD FRONT FOR THE WEEKEND.
&&
.MARINE...
GALE WARNING IN EFFECT AGAIN TODAY AS GUSTY W WINDS WILL PERSIST OVER
THE WATERS. WINDS WILL DIMINISH THIS EVENING...BUT A SCA WILL BE
NEEDED OVERNIGHT.
BREEZY NWLY WINDS WILL SUBSIDE BY SUNRISE SUN MRNG...THEN REMAIN
FAIRLY LIGHT UNTIL MON AFTN. A DRY COLD FRONT WILL SWING ACROSS THE
REGION DURING THE DAY...PICKING UP MARGINAL SCA GUSTS INTO THE EVE
HRS. LIGHTER WINDS FOR TUE...THEN PICKING UP OUT OF THE SOUTH ON
WED...AHEAD OF A STRONGER COLD FRONT THAT WILL ALSO BRING RAIN TO
THE REGION DURING THE MIDDLE PART OF THE WEEK. BY WED NIGHT...THIS
FEATURE WILL SLIDE OFF THE MID ATLC COAST...AS HIGH PRESSURE BUILDS
IN FOR THE REST OF THE WORK WEEK.
&&
.FIRE WEATHER...
DESPITE THE STRONG WNW WINDS OF 20-30 MPH WITH GUSTS NEAR 45 MPH
AND MIN RH VALUES BETWEEN 25-35 PERCENT TDA...FUEL MOISTURE WILL
BE TOO HIGH WARRANT ANY FIRE WEATHER HEADLINES.
&&
.EQUIPMENT...
KLWX WSR-88D RADAR IS STILL IN THE PROCESS OF BEING TESTED W/
DUAL POL TECHNOLOGY. SEE PRODUCT /WBCPNSLWX/ FOR DETAILS...OR
REFER TO WWW.WEATHER.GOV/LWX/DUALPOL_UPGRADE.PHP FOR ADDITIONAL
INFORMATION.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ501.
WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ003>007-
009>011-013-014-018-501-502.
VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ503.
WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ025>031-
036>040-042-053-054-501-503-504.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ501-
503-505.
WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ050>053-055-
501>506.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY
FOR ANZ530>534-537-539>543.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ530>543.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM EST SUNDAY
FOR ANZ535-536-538.
&&
$$
UPDATE...KLEIN
PREV DISC...KS/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
422 AM EST SAT FEB 25 2012
.SYNOPSIS...
A COLD NORTHWESTERLY FLOW WILL ALLOW FOR SCATTERED SNOW SHOWERS
WITH GUSTY WINDS TO CONTINUE ACROSS THE AREA TODAY. HIGH PRESSURE
WILL BRING AN END TO SNOW SHOWERS TONIGHT AND ALLOW FOR DRY
WEATHER THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES CYCLONIC FLOW ACROSS
THE EASTERN GREAT LAKES AND UPPER OHIO VALLEY. A WEST-
NORTHWESTERLY 850MB FLOW WITH COLD AIR ADVECTION IS ONGOING. AT THE
SURFACE, A 982MB SURFACE LOW ACROSS MAINE WITH A TIGHTENED
PRESSURE GRADIENT CONTINUE TO ALLOW FOR WINDS GUSTING AT 25 TO 35 MPH
AT TIMES ACROSS THE UPPER OHIO VALLEY. COLD AIR ADVECTION CONTINUE
TO FUEL SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS MOVING
ACROSS THE AREA.
TODAY...THE COLD NORTHWESTERLY FLOW OFF OF AN UNFROZEN LAKE ERIE WILL
CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA.
ALTHOUGH THERE IS NO HURON CONNECTION IN PLACE, FETCH ACROSS ERIE
ALONG WITH INVERSION LEVELS UP TO 9KFT INTO THE EARLY AFTERNOON
WILL ALLOW FOR SOME HEAVIER SNOW SHOWERS AND SQUALLS AT TIMES. IN
ADDITION, WIND GUSTS UP TO 35 MPH ACROSS THE LOWLANDS AND 45 MPH
ACROSS THE HIGHER ELEVATIONS WILL CONTINUE.
COVERAGE OF SNOW SHOWERS WILL DECREASE SOUTH OF THE LAKE EFFECT
ZONES THIS MORNING AND THUS THE ADVISORY THERE EXPIRES AT 15Z.
ADVISORY MAY NEED TO BE EXTENDED FOR CLARION/JEFFERSON COUTIES.
ADDITIONAL ACCUMULATION GENERALLY OF 1 TO 2 INCHES WILL BE
POSSIBLE IN THE ADVISORY AREAS, ALTHOUGH NOT OUT OF THE QUESTION
LOCALIZED AREAS IN THE LAKE EFFECT ZONES AND RIDGES COULD SEE 2 TO 4
ADDITIONAL INCHES. FORECAST TEMPS ARE CLOSER TO THE COOLER MET FOR
HIGHS, RANGING FROM NEAR 30 ALONG THE I-80 CORRIDOR AND EASTERN
RIDGES TO THE MID 30S ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
THERE IS STRONG OPERATIONAL MODEL AGREEMENT THAT A HIGH PRESSURE
RIDGE WILL APPROACH FROM THE WEST TONIGHT AND MOVE ACROSS THE AREA
ON SUNDAY. A SURFACE LOW WILL PASS NORTH OF THE AREA ON MONDAY. ALL
DEEPER MOISTURE WILL REMAIN NORTH OF THIS SYSTEM AS THE NEXT HIGH
APPROACHES FROM THE NORTHWEST.
WITH A DEEP LAYER OF DRY AIR MOVING INTO THE AREA AND SUBSIDENCE
ALOFT, ABUNDANT SUNSHINE CAN BE EXPECTED SUNDAY AND MONDAY. THIS
WILL ALLOW FOR TEMPERATURES TO MODERATE EACH DAY. HIGHS SUNDAY
WILL BE NEAR NORMAL SEASONAL VALUES, WARMING TO 10 DEGREES ABOVE
NORMAL ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS
AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN
RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AND
IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE
REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE
PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY.
AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE
PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT.
WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL
PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC
CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES
5-10 DEGREES ABOVE NORMAL.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
TWO PRIMARY AVIATION HAZARDS THROUGH THE TAF PERIOD ARE GUSTY
WINDS AND ISOLATED IFR/LIFR CONDITIONS IN HEAVY SNOW BANDS.
WIND GUSTS HAVE LIGHTENED SOMEWHAT THROUGH THE EVENING HOURS...BUT
MOST SITES CAN STILL EXPECT TO SEE WESTERLY 25 KT GUSTS
OVERNIGHT. GUSTS COULD PICK BACK UP TO 30-35 KTS THIS AFTERNOON.
MVFR CONDITIONS ARE EXPECTED IN OCCASIONAL SNOW SHOWERS IN ALL
LOCATIONS...WITH PREVAILING IFR CONDITIONS EXPECTED AT FKL AND DUJ
WITH MORE SNOW EXPECTED AT THOSE SITES. HEAVIER SNOW BANDS TONIGHT
HAVE DROPPED VISIBILITIES IN SOME LOCATIONS ALL THE WAY TO ONE-
HALF MILE...BUT THESE BANDS WILL NEED TO BE COVERED WITH TEMPO
GROUPS AS NEEDED THROUGH MUCH OF THE PERIOD.
SNOW SHOULD COME TO AN END THIS EVENING...WITH GUSTS ALSO
DIMINISHING AT THAT TIME.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND
MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ041.
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ013>016-020>023-073.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ007>009.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074-
076.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
136 AM EST SAT FEB 25 2012
.SYNOPSIS...
COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW
PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY.
HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM
SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A QUICK UPDATE HAS BEEN ISSUED TO ADD COUNTIES ALONG AND NORTH OF
THE PITTSBURGH METRO TO A WINTER WEATHER ADVISORY. TWO CORRIDORS
OF SNOW SQUALLS CONTINUE TO TRAIN OVER THE SAME AREAS. WITH UP TO
2 INCHES MEASURED IN THESE AREAS, ADDITIONAL SNOWFALL AMOUNTS LED
TO SHORT-FUSED WINTER WEATHER ADVISORY THROUGH THE MID-MORNING.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW
ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW
AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY
FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB
SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE
GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY.
WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR
SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS
AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN
NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND
IN MERCER COUNTY.
OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE
NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK
INSTABILITY AND WILL ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS
WITH REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1
TO 3 INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES
WITH A CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 3
TOTAL. OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS
DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND
THE MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME
SLICK ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION,
WITH TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL
STILL BE POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER
ELEVATIONS.
SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL
CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA.
ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND
UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS
WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS
ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE
BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS
WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY.
TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON.
WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY
OTHERWISE DRY WITH WARMING TEMPERATURES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS
AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN
RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AND
IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE
REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE
PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY.
AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE
PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT.
WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL
PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC
CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES
5-10 DEGREES ABOVE NORMAL.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
TWO PRIMARY AVIATION HAZARDS THROUGH THE TAF PERIOD ARE GUSTY
WINDS AND ISOLATED IFR/LIFR CONDITIONS IN HEAVY SNOW BANDS.
WIND GUSTS HAVE LIGHTENED SOMEWHAT THROUGH THE EVENING HOURS...BUT
MOST SITES CAN STILL EXPECT TO SEE WESTERLY 25 KT GUSTS
OVERNIGHT. GUSTS COULD PICK BACK UP TO 30-35 KTS THIS AFTERNOON.
MVFR CONDITIONS ARE EXPECTED IN OCCASIONAL SNOW SHOWERS IN ALL
LOCATIONS...WITH PREVAILING IFR CONDITIONS EXPECTED AT FKL AND DUJ
WITH MORE SNOW EXPECTED AT THOSE SITES. HEAVIER SNOW BANDS TONIGHT
HAVE DROPPED VISIBILITIES IN SOME LOCATIONS ALL THE WAY TO ONE-
HALF MILE...BUT THESE BANDS WILL NEED TO BE COVERED WITH TEMPO
GROUPS AS NEEDED THROUGH MUCH OF THE PERIOD.
SNOW SHOULD COME TO AN END THIS EVENING...WITH GUSTS ALSO
DIMINISHING AT THAT TIME.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND
MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ041.
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ013>016-020>023-073.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ007>009.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074-
076.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1252 AM EST SAT FEB 25 2012
.SYNOPSIS...
COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW
PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY.
HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM
SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A QUICK UPDATE HAS BEEN ISSUED TO ADD COUNTIES ALONG AND NORTH OF
THE PITTSBURGH METRO TO A WINTER WEATHER ADVISORY. TWO CORRIDORS
OF SNOW SQUALLS CONTINUE TO TRAIN OVER THE SAME AREAS. WITH UP TO
2 INCHES MEASURED IN THESE AREAS, ADDITIONAL SNOWFALL AMOUNTS LED
TO SHORT-FUSED WINTER WEATHER ADVISORY THROUGH THE MID-MORNING.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW
ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW
AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY
FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB
SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE
GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY.
WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR
SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS
AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN
NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND
IN MERCER COUNTY.
OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE
NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK
INSTABILITY ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS WITH
REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1 TO 3
INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES WITH A
CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 3 TOTAL.
OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS
DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND
THE MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME
SLICK ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION,
WITH TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL
STILL BE POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER
ELEVATIONS.
SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL
CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA.
ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND
UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS
WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS
ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE
BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS
WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY.
TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON.
WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY
OTHERWISE DRY WITH WARMING TEMPERATURES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS
AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN
RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AN
IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE
REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE
PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY.
AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE
PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT.
WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL
PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC
CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES
5-10 DEGREES ABOVE NORMAL
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WIND CONTINUES TO BE MAIN AVIATION HAZARD TONIGHT. BASED ON RECENT
NAM MODEL OUTPUT, WESTERLY WINDS CAN STILL GUST TO 35-40 KTS TIL
02Z, THEN SUBSIDE TO GUSTS OF 30 KTS, THAT CAN CONTINUE INTO
SATURDAY AFTERNOON.
REGARDING FLIGHT CONDITIONS, POST SYSTEM COOL DOWN COUPLED WITH
GREAT LAKES MOISTURE WILL RESULT IN A PROLONGED PERIOD OF
STRATOCUMULUS WITH CEILINGS MAINLY IN THE MVFR RANGE. EMBEDDED
BANDS OF LAKE EFFECT SNOW SHOWERS MAY YIELD BRIEF IFR EPISODES,
BUT ONLY CONFIDENT ENOUGH TO MENTION TEMPO IFR FOR KFKL AND KDUJ
DUE TO MORE PREVALENCE OF LAKE EFFECT SNOW SHOWERS.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND
MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
OHZ041.
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ013>016-020>023-073.
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ007>009.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074-
076.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023-
041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1149 PM EST FRI FEB 24 2012
.SYNOPSIS...
COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW
PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY.
HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM
SUNDAY INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED THIS
EVENING TO INCREASE SNOW AMOUNTS IN AREAS WHERE SNOW SQUALLS ARE
MOVING ACROSS THE AREA.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW
ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW
AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY
FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB
SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE
GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY.
WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR
SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS
AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN
NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND
IN MERCER COUNTY.
OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE
NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK
INSTABILITY ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS WITH
REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1 TO 3
INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES WITH A
CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 2 TOTAL.
OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS
DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND THE
MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME SLICK
ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION, WITH
TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL STILL BE
POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER
ELEVATIONS.
SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL
CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA.
ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND
UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS
WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS
ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80
CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE
BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS
WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY.
TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON.
WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY
OTHERWISE DRY WITH WARMING TEMPERATURES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS
AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN
RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AN
IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE
REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE
PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY.
AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE
PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT.
WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL
PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC
CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES
5-10 DEGREES ABOVE NORMAL
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
WIND CONTINUES TO BE MAIN AVIATION HAZARD TONIGHT. BASED ON RECENT
NAM MODEL OUTPUT, WESTERLY WINDS CAN STILL GUST TO 35-40 KTS TIL
02Z, THEN SUBSIDE TO GUSTS OF 30 KTS, THAT CAN CONTINUE INTO
SATURDAY AFTERNOON.
REGARDING FLIGHT CONDITIONS, POST SYSTEM COOL DOWN COUPLED WITH
GREAT LAKES MOISTURE WILL RESULT IN A PROLONGED PERIOD OF
STRATOCUMULUS WITH CEILINGS MAINLY IN THE MVFR RANGE. EMBEDDED
BANDS OF LAKE EFFECT SNOW SHOWERS MAY YIELD BRIEF IFR EPISODES,
BUT ONLY CONFIDENT ENOUGH TO MENTION TEMPO IFR FOR KFKL AND KDUJ
DUE TO MORE PREVALENCE OF LAKE EFFECT SNOW SHOWERS.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND
MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS
POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR MDZ001.
OH...NONE.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST SATURDAY FOR
PAZ007>009.
WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
117 PM EST SAT FEB 25 2012
.UPDATE...
ISSUED AT 116 PM EST SAT FEB 25 2012
NO MAJOR CHANGES TO THE GOING FORECAST THIS MORNING AND INTO THE
AFTN. LES BANDS OVER WRN LK SUPERIOR HAVE BECOME MORE DISORGANIZED
LATE THIS MORNING AND INTO EARLY AFTN AS SFC TROUGH HAS WEAKENED
AND HIGH PRESSURE RIDGE MOVES IN. THUS...HAVE LET THE LES
WARNING END AS EXPECTED AT 18Z. THAT BEING SAID...06-12Z MODEL RUNS
HAVE HELD UP MOISTURE AND HIGHER INVERSION HEIGHTS...SO HAVE DELAYED
THE ENDING OF THE -SHSN LATER THIS AFTN WHEN WINDS REALLY LIGHTEN
UP. ELSEWHERE...LIGHT LES CONTINUES IN NCNTRL UPPER MI. THE
STRONGEST BANDS IN WRN ALGER COUNTY ARE FAIRLY LIGHT AND KMQT RADAR
ESTIMATING ONLY ABOUT 0.25IN/HR. EXPECT THIS LIGHT LES TO GRADUALLY
SHIFT E THROUGH THE AFTN AND EARLY EVENING HOURS...AS LLVL FLOW
BACKS MORE TO THE WNW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING
WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A
BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS
HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW
WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF
ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W
OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE
APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL
CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF
THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH
GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME
RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES
FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE
SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN.
IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE
CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE
PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z
KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS
SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT
WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED
ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT
HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN
LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER
WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE
AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL
SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M
ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE
SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING
ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT
RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY
AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY
DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY
DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER
LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING
INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A
STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL
ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN...
NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS
FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE
STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON
COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY
HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE
POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE...
THERE WON`T BE MUCH MORE THAN A DUSTING.
ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES
RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT
WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM
W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE
CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND
INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW
SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR
BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING
WAA/ISENTROPIC ASCENT REGIME.
ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS
EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM
WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW...
MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS
SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF
ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG
ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX
SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS
SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER
CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS
SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF
GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF
NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS
GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS
1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND
THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY
FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE
SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND
24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z
GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW.
AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN
SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY
SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS
RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY
NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI
BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB
TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE
LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION.
SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING
SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY
ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN
CHECK...REMAINING STEADY THROUGH THE DAY.
HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE
TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER.
THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO
OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS
KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED
IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY
SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE
GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES
ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS
THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY
STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS
HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT
THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE
FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY
PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT
THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE.
STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS
AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY
WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO
-10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD
MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE
AVAILABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM EST SAT FEB 25 2012
EXPECT LES TO DIMINISH AT ALL THREE SITES THROUGH THE AFTERNOON
HOURS...WHICH SHOULD EVENTUALLY TRANSITION ALL SITES TO VFR
CONDITIONS BY THIS EVENING.
ATTENTION THEN TURNS TO LOW CURRENTLY OVER THE NORTHERN ROCKIES THAT
WILL APPROACH THE AREA DURING THE DAY ON SUN. THIS WILL BRING
INCREASING MID/HIGH CLOUDS TO THE AREA TONIGHT...WITH SNOW
DEVELOPING FROM WEST TO EAST DURING THE MORNING HOURS. HAVE BROUGHT
CONDITIONS DOWN TO MVFR/IFR AS A STARTING POINT...WITH THE LOWEST
VSBYS NEAR THE END OF THE TAF PERIOD. ACTUALLY HEAVIES SNOW LOOKS TO
FALL JUST AFTER THE CURRENT TAF PERIOD AND WILL LIKELY NEED VSBYS
BELOW ALT LANDING MINS HEADING INTO SUN AFTN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EST SAT FEB 25 2012
ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A
PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES
SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING
TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY
BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE
SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE
NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS
THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW
PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A
POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW
WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON
WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH
PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE
NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248-
250.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST SAT FEB 25 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING
WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A
BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS
HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW
WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF
ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W
OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE
APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL
CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF
THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH
GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME
RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES
FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE
SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN.
IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE
CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE
PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z
KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS
SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT
WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED
ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT
HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN
LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER
WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE
AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL
SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M
ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE
SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING
ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT
RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY
AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY
DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY
DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER
LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING
INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A
STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL
ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN...
NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS
FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE
STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON
COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY
HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE
POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE...
THERE WON`T BE MUCH MORE THAN A DUSTING.
ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES
RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT
WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM
W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE
CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND
INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW
SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR
BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING
WAA/ISENTROPIC ASCENT REGIME.
ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS
EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM
WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW...
MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS
SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF
ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG
ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX
SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS
SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER
CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS
SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF
GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF
NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS
GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS
1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND
THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY
FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE
SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND
24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z
GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW.
AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN
SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY
SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS
RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY
NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI
BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB
TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE
LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION.
SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING
SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY
ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN
CHECK...REMAINING STEADY THROUGH THE DAY.
HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE
TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER.
THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO
OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS
KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED
IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY
SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE
GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES
ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS
THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY
STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS
HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT
THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE
FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY
PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT
THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE.
STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS
AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY
WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO
-10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD
MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE
AVAILABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM EST SAT FEB 25 2012
EXPECT LES TO DIMINISH AT ALL THREE SITES THROUGH THE AFTERNOON
HOURS...WHICH SHOULD EVENTUALLY TRANSITION ALL SITES TO VFR
CONDITIONS BY THIS EVENING.
ATTENTION THEN TURNS TO LOW CURRENTLY OVER THE NORTHERN ROCKIES THAT
WILL APPROACH THE AREA DURING THE DAY ON SUN. THIS WILL BRING
INCREASING MID/HIGH CLOUDS TO THE AREA TONIGHT...WITH SNOW
DEVELOPING FROM WEST TO EAST DURING THE MORNING HOURS. HAVE BROUGHT
CONDITIONS DOWN TO MVFR/IFR AS A STARTING POINT...WITH THE LOWEST
VSBYS NEAR THE END OF THE TAF PERIOD. ACTUALLY HEAVIES SNOW LOOKS TO
FALL JUST AFTER THE CURRENT TAF PERIOD AND WILL LIKELY NEED VSBYS
BELOW ALT LANDING MINS HEADING INTO SUN AFTN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EST SAT FEB 25 2012
ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A
PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES
SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING
TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY
BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE
SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE
NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS
THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW
PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A
POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW
WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON
WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH
PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE
NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248-
250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
601 AM EST SAT FEB 25 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING
WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A
BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS
HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW
WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF
ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W
OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE
APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL
CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF
THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH
GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME
RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES
FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE
SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN.
IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE
CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE
PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z
KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS
SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT
WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED
ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT
HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN
LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER
WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE
AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL
SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M
ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE
SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING
ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT
RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY
AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY
DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY
DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER
LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING
INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A
STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL
ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN...
NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS
FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE
STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON
COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY
HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE
POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE...
THERE WON`T BE MUCH MORE THAN A DUSTING.
ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES
RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT
WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM
W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE
CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND
INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW
SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR
BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING
WAA/ISENTROPIC ASCENT REGIME.
ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS
EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM
WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW...
MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS
SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF
ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG
ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX
SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS
SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER
CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS
SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF
GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF
NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS
GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS
1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND
THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY
FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE
SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND
24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z
GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW.
AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN
SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY
SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS
RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY
NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI
BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB
TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE
LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION.
SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING
SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY
ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN
CHECK...REMAINING STEADY THROUGH THE DAY.
HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE
TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER.
THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO
OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS
KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED
IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY
SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE
GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES
ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS
THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY
STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS
HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT
THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE
FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY
PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT
THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE.
STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS
AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY
WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO
-10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD
MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE
AVAILABLE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM EST SAT FEB 25 2012
APPROACHING MIDLEVEL RIDGE/RISING HEIGHTS/SUBSIDENCE AND DRIER AIR
WILL BRING AN END TO -SHSN/FLURRIES OFF LAKE SUPERIOR TODAY. BEFORE
THAT HAPPENS...LINGERING...BUT WEAKENING CONVERGENCE ZONE OVER WRN
LAKE SUPERIOR INTO FAR WRN UPPER MI MAY STILL YIELD HEAVIER SHSN AND
IFR CONDITIONS AT KIWD FOR THE NEXT FEW HRS. OTHERWISE...MVFR
CONDITIONS AT KIWD SHOULD TREND TO VFR BY EVENING IF NOT SOONER AS
WINDS BACK AND CUTOFF OVERWATER TRAJECTORY. AT KCMX...MVFR CIGS AND
MAYBE A FEW FLURRIES WILL PERSIST TODAY. MVFR CIGS SHOULD SCATTER
OUT THIS EVENING AS SFC HIGH PRES RIDGE PASSES. AT KSAW...MVFR CIGS
SHOULD SCATTER OUT MID TO LATE AFTN WITH FLURRIES ENDING AS WINDS
BACK TO A NW DIRECTION. AFTER SFC HIGH PRES RIDGE PASSES TONIGHT...
DEVELOPING UPSLOPE SSE FLOW OFF LAKE MICHIGAN MAY BRING A RETURN OF
MVFR CIGS LATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EST SAT FEB 25 2012
ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A
PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES
SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING
TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY
BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE
SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE
NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS
THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW
PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A
POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW
WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON
WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH
PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE
NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ002-009.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248-
250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
514 AM EST SAT FEB 25 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING
WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A
BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS
HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW
WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF
ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W
OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE
APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL
CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF
THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH
GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME
RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES
FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE
SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN.
IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE
CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE
PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z
KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS
SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT
WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED
ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT
HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN
LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER
WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE
AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL
SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M
ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE
SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING
ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT
RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY
AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY
DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY
DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER
LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING
INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A
STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL
ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN...
NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS
FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE
STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON
COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY
HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE
POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE...
THERE WON`T BE MUCH MORE THAN A DUSTING.
ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES
RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT
WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM
W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE
CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND
INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW
SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR
BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING
WAA/ISENTROPIC ASCENT REGIME.
ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS
EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM
WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW...
MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS
SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF
ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG
ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX
SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS
SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER
CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS
SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF
GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF
NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS
GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS
1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND
THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY
FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 514 AM EST SAT FEB 25 2012
THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE
SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND
24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z
GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW.
AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN
SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY
SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS
RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY
NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI
BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB
TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE
LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION.
SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING
SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY
ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN
CHECK...REMAINING STEADY THROUGH THE DAY.
HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE
TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER.
THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO
OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS
KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED
IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY
SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE
GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES
ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS
THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY
STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS
HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT
THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE
FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY
PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT
THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE.
STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS
AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY
WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO
-10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD
MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE
AVAILABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1231 AM EST SAT FEB 25 2012
CONTINUED NRLY FLOW COMBINED WITH COOLER AIR MOVING ACROSS LAKE
SUPERIOR WILL MAINTAIN LES AT TAF SITES INTO THE MORNING HRS. EXPECT
MORE PERSISTENT AND HEAVIER LES LATE TONIGHT AT KIWD WHERE CONVERGENT
NRLY WIND FIELD AND LONGER PERIOD OF DEEPER MOISTURE AND POTENTIAL
ENHANCEMENT FROM NEARBY SHORTWAVE TO RESULT IN CONDITIONS LOWERING TO
ALT LANDING MINS THERE. EXPECT CONDITIONS TO IMPROVE BY LATE MORNING
AT KIWD AS DRIER AIR BEGINS TO MOVE IN. WINDS SHIFTING NORTH OVER
LAKE SUPERIOR COULD PUSH SOME HEAVIER LES BANDS INTO KSAW THROUGH 08Z
BUT EXPECT HEAVIER LES TO COLLASPE QUICKLY AS DRIER AIR MOVES IN
NORTH OF THE LAKE. AS WINDS BACK GRADUALLY TO THE NW EXPECT
CONDITIONS TO IMPROVE TO VFR AT KSAW BY MIDDAY. KCMX WILL SEE MVFR
CIGS BUT ONLY VERY LIGHT LES WITH LESS FAVORABLE N/NNW WIND DIRECTION
THERE. EXPECT KCMX TO ALSO IMPROVE TO VFR THIS AFTERNOON AS DRIER AIR
WORKS IN FM NW OF THE LAKE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 514 AM EST SAT FEB 25 2012
ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A
PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES
SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING
TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY
BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE
SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE
NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS
THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW
PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A
POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW
WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON
WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH
PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE
NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248-
250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
701 PM CST SUN FEB 26 2012
.SHORT TERM...
MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON
RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE
SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB
PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP
OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY
DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM
AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL
WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE
HEADLINES IN THE WEST.
SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING
DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS
EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT
REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE
POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT
OVER THAT AREA...INTO NORTHWEST WISCONSIN.
SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST
TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO
KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH
THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T
VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM
THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER
TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL
ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST
PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME
NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG
A WAVE WILL RESULT.
.PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/
AVIATION.../0Z TAF ISSUANCE/
CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY
IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND
HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO
SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST
LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS
IMPROVING TO LOW END VFR BY MONDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/
.WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA
..WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST
LOUIS/CARLTON COUNTIES...
SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS
COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS.
LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS
COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS
PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF
MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A
DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY.
85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS
COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER
AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS
FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS
WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A
SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN
EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY.
TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT.
EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS
AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF
WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS
WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA.
SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA.
HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON
RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP
SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF
MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS.
TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER
BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD
COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT.
EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED
TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH
WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER
AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME
DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES
ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA
ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW
BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE
SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING
THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION
TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING
ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER
AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY
HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME
POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO
THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO
TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT
WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE
ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE
AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY
STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT
RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING
LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I
WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT
SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO
TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM
SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED
WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS
ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT
THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN.
AVIATION.../18Z TAF ISSUANCE/
A WINTER STORM WILL CONTINUE TO IMPACT THE NORTHLAND OVER MUCH OF
THE TAF PERIOD. AT THIS POINT...IT APPEARS THAT THE MOST DRAMATIC
VISIBILITY RESTRICTIONS WOULD BE ACROSS THE IRON RANGE AND THE
ARROWHEAD...WHERE A DEFORMATION AXIS WILL SET UP AND ROTATE
THROUGH THAT AREA. AREAS TO THE SOUTH AND FAR NORTH WILL SEE MORE
EPISODIC PERIODS OF HEAVIER SNOW. KHIB LOOKS TO SEE THE MOST
DRAMATIC VSBY RESTRICTIONS. OVERALL...FAIRLY WIDESPREAD MVFR TO
EVEN LIFR CONDITIONS CAN BE EXPECTED. CONDITIONS WILL IMPROVE
LATER TONIGHT AND ON MONDAY MORNING.
&&
.POINT TEMPS/POPS...
DLH 15 23 12 28 / 100 10 10 60
INL 9 19 4 28 / 90 20 10 10
BRD 15 22 16 30 / 70 10 10 70
HYR 18 26 10 32 / 70 10 10 60
ASX 21 26 11 31 / 90 30 10 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ010>012-
018>021-025-026-035-037.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MNZ025-033>038.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ033-034-036-
038.
WI...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR WIZ001>004-006>009.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004.
&&
$$
SHORT TERM...MELDE/CANNON
LONG TERM....DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
1208 PM CST SAT FEB 25 2012
.AVIATION.../18Z TAF ISSUANCE/
THE LOW CLOUDS IN PLACE ACROSS MUCH OF THE NORTHLAND THIS MORNING
APPEAR TO BE BURNING OFF FAIRLY QUICKLY AS OF MIDDAY. HAVE KEPT
SOME TEMPO BROKEN CONDITIONS AROUND FOR A TIME...BUT WE SHOULD SEE
THE TREND CONTINUE FOR MUCH OF THE REGION. THE FOCUS WILL THEN
SHIFT TO INCREASING AND THICKENING CLOUDS OVERNIGHT...AHEAD OF THE
LOW PRESSURE SYSTEM MOVING INTO THE REGION ON SUNDAY. LIGHT SNOW
SHOULD DEVELOP LATER IN THE NIGHT AND PROGRESSIVELY INCREASE IN
INTENSITY THROUGHOUT SUNDAY MORNING. AS A RESULT...WILL GRADUALLY
LOWER CIGS/VSBYS WITH TIME.
&&
.PREV DISCUSSION... /ISSUED 1025 AM CST SAT FEB 25 2012/
UPDATE...PESKY LOW CLOUDS STILL BEING MAINTAINED ACROSS LARGE
PART OF CWA. UPPER FLOW SHOWS UPPER JET AXIS IS TRANSLATING EAST
ACROSS WRN CWA WITH AREA OF SHEAR VORTICITY BEING PRODUCED OVER
ERN CWA. RUC13 85/70H RH STILL ABOVE 60 PERCENT EAST OF A INL TO
BRD LINE HOWEVER STRATUS LAYER IS THIN WITH AREA LAKES SHOWING
THROUGH VIS IMAGERY. SLOWED CLEARING PROCESS TODAY OVER ERN HALF
OF CWA. ADDED POPS OVER WISC ZONES AS SHEAR VORTICITY WITHIN
CYCLONIC MOIST FLOW PROMOTES ADDITIONAL SNOW SHOWER DEVELOPMENT.
WILL LET WSY EXPIRE OVER ERN SNOW BELT AS PLANNED AT 11AM THIS
MORNING.
DEVELOPING SYSTEM WEST OF REGION IS STILL A BIT TRICKY AS
UPPER TROF CARRYING SHORTWAVE SYSTEM IS SHOWING CONSIDERABLE
BAGGINESS...ALLOWING POTENTIALLY SIGNIFICANT DIFFERENCE IN
POSITION/EVOLUTION OF CLOSING OFF A MID LVL CENTER. DESPITE
THAT...CURRENT NWP FCSTS STILL MAINTAIN CONSENSUS REGARDING TRACK
OF LOW/MID LVL PRESSURE CENTERS. THIS WOULD KEEP HIGHEST
PROBABILITY OF MAXIMUM SNOW ACCUMULATIONS ACROSS NRN 2/3 OF CWA.
PREV DISCUSSION... /ISSUED 531 AM CST SAT FEB 25 2012/
AVIATION...12Z TAFS.
MVFR CIGS WITH FLURRIES OR LIGHT SNOW WILL AFFECT ALL TAF SITES
THROUGH THE 15Z TO 18Z TIME FRAME. THE EXCEPTION IS AT KINL WHERE
VFR CIGS WILL PREVAIL. AS THE SFC RIDGE AXIS MOVES OVER THE FA
TODAY...EXPECT ALL SITES TO REMAIN VFR. AFTER 26/03Z...CLOUDS WILL
BE ON THE INCREASE AHEAD OF THE APPROACHING WINTER STORM. LIGHT
SNOW WILL GRADUALLY OVERSPREAD THE AREA AFTER 06Z WITH CIGS/VSBYS
DROPPING INTO THE MVFR RANGE.
PREV DISCUSSION... /ISSUED 456 AM CST SAT FEB 25 2012/
SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A DEPARTING LOW
PRESSURE SYSTEM OVER THE NORTHEAST...AND A RIDGE OF HIGH PRESSURE
OVER THE PLAINS...WITH THE NORTHLAND IN BETWEEN UNDER NWLY FLOW.
THE NWLY WINDS COMBINED WITH COLD AIR HAVE RESULTED IN LAKE
EFFECT SNOW ALONG THE SOUTH SHORE OF LAKE SUPERIOR...FROM THE
BAYFIELD PENINSULA TO THE GOGEBIC RANGE WHERE 4.5 INCHES OF SNOW
HAS FALLEN SO FAR AT GILE WI. THE SNOW SHOWERS WILL CONTINUE
ACROSS THE SOUTH SHORE THIS MORNING...BUT THE SNOWFALL IS NOT
EXPECTED TO BE HEAVY DUE TO UNFAVORABLE SURFACE WIND DIRECTION. AS
A RESULT...ONLY AN ADDITIONAL 1 TO 2 INCHES ARE EXPECTED BY NOON
TODAY.
THE OTHER FORECAST CONCERN FOR THE SHORT TERM IS A VIGOROUS
SHORTWAVE WHICH IS PROGGED TO TRACK EWD FROM NRN PLAINS ACROSS THE
UPPER MIDWEST TONIGHT THROUGH SUNDAY NIGHT. THERE ARE STILL SOME
DIFFERENCES BETWEEN THE VARIOUS MODELS...WITH THE GFS AND GEM
SHOWING THE HEAVIEST PRECIP AMOUNTS. THE GFS AND GEM ALSO TAKE THE
HEAVIER SNOW FURTHER SOUTH TO INCLUDE ALL OF NORTHEAST MINNESOTA
INCLUDING THE BRAINERD AND DULUTH AREAS. THE ECMWF AND NAM FOCUS
THE HEAVIEST SNOW ACROSS OUR NRN ZONES. BECAUSE OF THESE DIFFERING
SOLUTIONS...WE HAVE DECIDED TO GO WITH AN AVERAGE OF THE MAIN NWP
MODELS SIMILAR TO HPC`S SOLUTION. THIS WILL RESULT IN WARNING
SNOWFALL AMOUNTS OF 5 TO 8 INCHES ACROSS OUR NRN ZONES...GENERALLY
ALONG AND NORTH OF US HIGHWAY 2...WITH GRADUALLY LESSER AMOUNTS
FARTHER SOUTH. ATTM WE OPTED TO GO WITH A WINTER WEATHER ADVISORY
FOR THE BRAINERD AND DULUTH AREAS WITH SNOWFALL AMOUNTS GENERALLY
RANGING FROM THE 3 TO 6 INCHES. HOWEVER IF THE GEM AND GFS
SOLUTIONS TURN OUT TO BE CORRECT...THESE AREAS WILL NEED TO BE
UPGRADED TO A WARNING. FINALLY ACROSS PINE COUNTY AND NWRN WI...WE
HAVE DECIDED NOT TO ISSUE ANY HEADLINES ATTM SINCE WE EXPECT SNOWFALL
AMOUNTS TO STAY BELOW ADVISORY LEVEL. HOWEVER THE DOUGLAS TO IRON
COUNTY REGION WILL ALSO NEED TO BE MONITORED AS A COMBINATION OF
SYNOPTIC AND LAKE EFFECT SNOW MAY RESULT IN HEAVIER THAN
ANTICIPATED SNOWFALL AMOUNTS. THERE MAY BE SOME AREAS OF SHORT-
LIVED BLOWING SNOW...ALTHOUGH WINDS ARE NOT EXPECTED TO BE STRONG.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
THE UPPER LEVEL TROF/SFC LOW EXIT THE AREA SUNDAY NIGHT. WITH
HEADLINES IN PLACE...HAVE HIGHEST POPS ALIGNED WITH THE HEADLINES.
SOME LES SHOWERS ARE POSSIBLE LATE SUNDAY NIGHT. HOWEVER...MODELS
DISAGREE ON POTENTIAL WITH DIFFERENCES IN WIND FIELD/FETCH/CAA.
POPS ALONG THE SOUTH SHORE ARE A MODEL COMPROMISE. ON MONDAY
MORNING...SOME BACKWASH SNOW SHOWERS ARE POSSIBLE ALONG WITH SOME
LES SHOWERS ALONG THE SOUTH SHORE. BY AFTERNOON...SFC/UPPER
RIDGING ARRIVES TO END ALL SNOW CHANCES. MODEL DIFFERENCES BEGIN
AGAIN ON MONDAY NIGHT AHEAD OF THE NEXT SYSTEM PROGGED TO AFFECT
THE FA. USED THE 25/00Z ECMWF WHICH KEEPS THE RIDGING THROUGH 06Z
TUESDAY AS MODELS TEND TO BE TOO FAST AT BREAKING DOWN RIDGING.
USED A MODEL BLEND AFTER 06Z TUESDAY WITH THE ONSET OF THE NEXT
ROUND OF SNOW. MODEL SOLUTIONS ARE ONCE AGAIN VARYING WIDELY AS A
CUT OFF UPPER LOW CROSSES OUT OF THE ROCKIES AND INTO THE PLAINS.
CONTINUED TO USE A CONSENSUS APPROACH WITH THIS SYSTEM AND HOW IT
AFFECTS THE FA FROM TUESDAY THROUGH WEDNESDAY NIGHT. THIS SYSTEM
WILL TAP INTO GULF OF MEXICO MOISTURE SO THE POSSIBILITY FOR
SIGNIFICANT SNOW AMOUNTS CANNOT BE RULED OUT. HOWEVER...THE MODEL
DIFFERENCES WITH THE SFC LOW TRACK PRECLUDE USING ANY HEADLINES
ATTM. WILL KEEP THE BEEFY WORDING IN THE HWO. MODEL DIFFERENCES
BECOME MORE PRONOUNCED FOR THURSDAY AND FRIDAY AND USED THE MODEL
BLEND.
&&
.POINT TEMPS/POPS...
DLH 24 18 30 16 / 10 60 90 50
INL 20 12 26 7 / 10 80 100 60
BRD 25 19 30 13 / 10 60 80 60
HYR 27 18 35 19 / 40 20 80 40
ASX 28 19 34 21 / 60 20 90 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR MNZ010>012-018>021-025-026.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR MNZ033>037.
WI...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....DAP
AVIATION...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1025 AM CST SAT FEB 25 2012
.UPDATE...PESKY LOW CLOUDS STILL BEING MAINTAINED ACROSS LARGE
PART OF CWA. UPPER FLOW SHOWS UPPER JET AXIS IS TRANSLATING EAST
ACROSS WRN CWA WITH AREA OF SHEAR VORTICITY BEING PRODUCED OVER
ERN CWA. RUC13 85/70H RH STILL ABOVE 60 PERCENT EAST OF A INL TO
BRD LINE HOWEVER STRATUS LAYER IS THIN WITH AREA LAKES SHOWING
THROUGH VIS IMAGERY. SLOWED CLEARING PROCESS TODAY OVER ERN HALF
OF CWA. ADDED POPS OVER WISC ZONES AS SHEAR VORTICITY WITHIN
CYCLONIC MOIST FLOW PROMOTES ADDITIONAL SNOW SHOWER DEVELOPMENT.
WILL LET WSY EXPIRE OVER ERN SNOW BELT AS PLANNED AT 11AM THIS
MORNING.
DEVELOPING SYSTEM WEST OF REGION IS STILL A BIT TRICKY AS
UPPER TROF CARRYING SHORTWAVE SYSTEM IS SHOWING CONSIDERABLE
BAGGINESS...ALLOWING POTENTIALLY SIGNIFICANT DIFFERENCE IN
POSITION/EVOLUTION OF CLOSING OFF A MID LVL CENTER. DESPITE
THAT...CURRENT NWP FCSTS STILL MAINTAIN CONSENSUS REGARDING TRACK
OF LOW/MID LVL PRESSURE CENTERS. THIS WOULD KEEP HIGHEST
PROBABILITY OF MAXIMUM SNOW ACCUMULATIONS ACROSS NRN 2/3 OF CWA.
&&
.PREV DISCUSSION... /ISSUED 531 AM CST SAT FEB 25 2012/
AVIATION...12Z TAFS.
MVFR CIGS WITH FLURRIES OR LIGHT SNOW WILL AFFECT ALL TAF SITES
THROUGH THE 15Z TO 18Z TIME FRAME. THE EXCEPTION IS AT KINL WHERE
VFR CIGS WILL PREVAIL. AS THE SFC RIDGE AXIS MOVES OVER THE FA
TODAY...EXPECT ALL SITES TO REMAIN VFR. AFTER 26/03Z...CLOUDS WILL
BE ON THE INCREASE AHEAD OF THE APPROACHING WINTER STORM. LIGHT
SNOW WILL GRADUALLY OVERSPREAD THE AREA AFTER 06Z WITH CIGS/VSBYS
DROPPING INTO THE MVFR RANGE.
PREV DISCUSSION... /ISSUED 456 AM CST SAT FEB 25 2012/
SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A DEPARTING LOW
PRESSURE SYSTEM OVER THE NORTHEAST...AND A RIDGE OF HIGH PRESSURE
OVER THE PLAINS...WITH THE NORTHLAND IN BETWEEN UNDER NWLY FLOW.
THE NWLY WINDS COMBINED WITH COLD AIR HAVE RESULTED IN LAKE
EFFECT SNOW ALONG THE SOUTH SHORE OF LAKE SUPERIOR...FROM THE
BAYFIELD PENINSULA TO THE GOGEBIC RANGE WHERE 4.5 INCHES OF SNOW
HAS FALLEN SO FAR AT GILE WI. THE SNOW SHOWERS WILL CONTINUE
ACROSS THE SOUTH SHORE THIS MORNING...BUT THE SNOWFALL IS NOT
EXPECTED TO BE HEAVY DUE TO UNFAVORABLE SURFACE WIND DIRECTION. AS
A RESULT...ONLY AN ADDITIONAL 1 TO 2 INCHES ARE EXPECTED BY NOON
TODAY.
THE OTHER FORECAST CONCERN FOR THE SHORT TERM IS A VIGOROUS
SHORTWAVE WHICH IS PROGGED TO TRACK EWD FROM NRN PLAINS ACROSS THE
UPPER MIDWEST TONIGHT THROUGH SUNDAY NIGHT. THERE ARE STILL SOME
DIFFERENCES BETWEEN THE VARIOUS MODELS...WITH THE GFS AND GEM
SHOWING THE HEAVIEST PRECIP AMOUNTS. THE GFS AND GEM ALSO TAKE THE
HEAVIER SNOW FURTHER SOUTH TO INCLUDE ALL OF NORTHEAST MINNESOTA
INCLUDING THE BRAINERD AND DULUTH AREAS. THE ECMWF AND NAM FOCUS
THE HEAVIEST SNOW ACROSS OUR NRN ZONES. BECAUSE OF THESE DIFFERING
SOLUTIONS...WE HAVE DECIDED TO GO WITH AN AVERAGE OF THE MAIN NWP
MODELS SIMILAR TO HPC`S SOLUTION. THIS WILL RESULT IN WARNING
SNOWFALL AMOUNTS OF 5 TO 8 INCHES ACROSS OUR NRN ZONES...GENERALLY
ALONG AND NORTH OF US HIGHWAY 2...WITH GRADUALLY LESSER AMOUNTS
FARTHER SOUTH. ATTM WE OPTED TO GO WITH A WINTER WEATHER ADVISORY
FOR THE BRAINERD AND DULUTH AREAS WITH SNOWFALL AMOUNTS GENERALLY
RANGING FROM THE 3 TO 6 INCHES. HOWEVER IF THE GEM AND GFS
SOLUTIONS TURN OUT TO BE CORRECT...THESE AREAS WILL NEED TO BE
UPGRADED TO A WARNING. FINALLY ACROSS PINE COUNTY AND NWRN WI...WE
HAVE DECIDED NOT TO ISSUE ANY HEADLINES ATTM SINCE WE EXPECT SNOWFALL
AMOUNTS TO STAY BELOW ADVISORY LEVEL. HOWEVER THE DOUGLAS TO IRON
COUNTY REGION WILL ALSO NEED TO BE MONITORED AS A COMBINATION OF
SYNOPTIC AND LAKE EFFECT SNOW MAY RESULT IN HEAVIER THAN
ANTICIPATED SNOWFALL AMOUNTS. THERE MAY BE SOME AREAS OF SHORT-
LIVED BLOWING SNOW...ALTHOUGH WINDS ARE NOT EXPECTED TO BE STRONG.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
THE UPPER LEVEL TROF/SFC LOW EXIT THE AREA SUNDAY NIGHT. WITH
HEADLINES IN PLACE...HAVE HIGHEST POPS ALIGNED WITH THE HEADLINES.
SOME LES SHOWERS ARE POSSIBLE LATE SUNDAY NIGHT. HOWEVER...MODELS
DISAGREE ON POTENTIAL WITH DIFFERENCES IN WIND FIELD/FETCH/CAA.
POPS ALONG THE SOUTH SHORE ARE A MODEL COMPROMISE. ON MONDAY
MORNING...SOME BACKWASH SNOW SHOWERS ARE POSSIBLE ALONG WITH SOME
LES SHOWERS ALONG THE SOUTH SHORE. BY AFTERNOON...SFC/UPPER
RIDGING ARRIVES TO END ALL SNOW CHANCES. MODEL DIFFERENCES BEGIN
AGAIN ON MONDAY NIGHT AHEAD OF THE NEXT SYSTEM PROGGED TO AFFECT
THE FA. USED THE 25/00Z ECMWF WHICH KEEPS THE RIDGING THROUGH 06Z
TUESDAY AS MODELS TEND TO BE TOO FAST AT BREAKING DOWN RIDGING.
USED A MODEL BLEND AFTER 06Z TUESDAY WITH THE ONSET OF THE NEXT
ROUND OF SNOW. MODEL SOLUTIONS ARE ONCE AGAIN VARYING WIDELY AS A
CUT OFF UPPER LOW CROSSES OUT OF THE ROCKIES AND INTO THE PLAINS.
CONTINUED TO USE A CONSENSUS APPROACH WITH THIS SYSTEM AND HOW IT
AFFECTS THE FA FROM TUESDAY THROUGH WEDNESDAY NIGHT. THIS SYSTEM
WILL TAP INTO GULF OF MEXICO MOISTURE SO THE POSSIBILITY FOR
SIGNIFICANT SNOW AMOUNTS CANNOT BE RULED OUT. HOWEVER...THE MODEL
DIFFERENCES WITH THE SFC LOW TRACK PRECLUDE USING ANY HEADLINES
ATTM. WILL KEEP THE BEEFY WORDING IN THE HWO. MODEL DIFFERENCES
BECOME MORE PRONOUNCED FOR THURSDAY AND FRIDAY AND USED THE MODEL
BLEND.
&&
.POINT TEMPS/POPS...
DLH 24 18 30 16 / 10 60 90 50
INL 20 12 26 7 / 10 80 100 60
BRD 25 19 30 13 / 10 60 80 60
HYR 27 18 35 19 / 40 20 80 40
ASX 28 19 34 21 / 60 20 90 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR MNZ010>012-018>021-025-026.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY
FOR MNZ033>037.
WI...WINTER WEATHER ADVISORY UNTIL 11 AM CST THIS MORNING FOR
WIZ002>004.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1252 PM EST SAT FEB 25 2012
.SYNOPSIS...
A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES
WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA
TODAY. WINDS WILL ALSO OCCASIONALLY GUST ABOVE 40 MPH. HIGH
PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING
SKIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...CHENANGO AND CORTLAND COUNTIES...ALONG WITH DELAWARE
AND OTSEGO COUNTIES WITHIN THE PAST COUPLE HOURS...HAVE BEEN ADDED TO
THE LAKE EFFECT SNOW ADVISORY.
COMBINATION OF LAKE EFFECT AND UPSLOPE EFFECTS HAVE ANCHORED SNOW
SHOWERS IN THE HIGHER TERRAIN FOR OTSEGO AND DELAWARE
COUNTIES...WITH REPORTS OF BETWEEN 3 AND 4 INCHES ALREADY RECEIVED
AS OF A LITTLE AFTER 8 AM. MEANWHILE...NARROW AND FAIRLY INTENSE
SNOW BAND WITH UPSTREAM LAKE HURON CONNECTION...HOOKS UP TO NORTH
OF BUFFALO...THROUGH ROCHESTER...INTO NORTHERN CORTLAND/CHENANGO
COUNTIES. A SECOND BAND...WITH GEORGIAN BAY-LAKE ONTARIO
CONNECTION...IS BEGINNING TO BREAK LAKE-TO-LAKE CONNECTION
UPSTREAM...YET REMAINS FAIRLY STOUT IN ONONDAGA-MADISON COUNTIES.
WITH PASSAGE OF SHORTWAVE THE NEXT SEVERAL HOURS...BOTH OF THESE
BANDS WILL SHIFT SOUTH TO YIELD ADDITIONAL SNOWFALL FOR CHENANGO-
CORTLAND COUNTIES ON TOP OF WHAT HAS ALREADY OCCURRED...AS WELL AS
OTSEGO/DELAWARE WITH AID OF UPSLOPE ENHANCEMENT. SOUTH OF THE
ADVISORY ZONES...SQUALLS WILL OCCUR YET WILL BE TRANSIENT...AND
THUS WITH SNOW TOTALS BELOW ADVISORY CRITERIA.
WE ARE EXPECTING 3 TO 6 INCHES TOTAL SNOW IN THE ADVISORY
AREA...WITH HIGHER ELEVATIONS OF ONEIDA AND OTSEGO COUNTIES
PUSHING INTO 5 TO 7 INCHES RANGE...BEFORE THE SNOW SHOWERS
DIMINISH THIS EVENING. POPS AND SNOW AMOUNTS WERE ADJUSTED...TO
REFLECT UPDATES AS DESCRIBED ABOVE...BASED ON EXPECTED EVOLUTION
OF LAKE EFFECT BANDS THROUGH THE DAY.
PREVIOUS DISCUSSION...
MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING
ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA
COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO
A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS
COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO
THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE
WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW
AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY
SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF
DURING THE DAY.
CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL
PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY
SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN
TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY
CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY
NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT
AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF
SNOW LOOKS LIKE A GOOD BET.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION
WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS
IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK.
TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER
MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT
WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR
ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A
WEAK AND DRY COLD FNT LATER MON OR EARLY TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT
WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM
THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY.
MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD
NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY...
PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK...
POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON
WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN...
ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION
EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY
A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER
WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF
INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD
THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE-
DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY
UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM
COULD END AS SOME SNOW SHOWERS ON THURSDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WDSPRD IFR/MVFR THIS AFTN DUE TO SHSN AND CIGS. BAND OF SQUALLS
WILL PRODUCE LIFR ACRS THE SRN TIER BY MID AFTN. DRIER AIR WORKING
INTO THE NORTH SXNS WILL GRADUALLY SPREAD S...BUT PATCHY LAKE
CLDS/ISOLD MVFR MAY PERSIST WELL INTO THE OVRNGT HRS...BEST CHC
WOULD BE SYR/ITH/BGM. VFR XPCTD ALL AREAS ON SUNDAY UNDER PC OR
MOSTLY CLR SKIES. WINDS THIS AFTN NWLY 15-30 MPH...DIMINISHING
LATER THIS EVNG TO 10-15 KTS AND NW WINDS ARND 10 KTS ON SUNDAY.
.OUTLOOK...
MON/TUE...MAINLY VFR.
TUE NGT/WED/THU...IFR/MVFR MIXED PCPN OR RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ009-018-036-037-044>046-057.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/MDP
SHORT TERM...DGM
LONG TERM...HEDEN/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
951 AM EST SAT FEB 25 2012
.SYNOPSIS...
A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES
WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA
TODAY. WINDS WILL ALSO OCCASIONALLY GUST ABOVE 40 MPH. HIGH
PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING
SKIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
945 AM UPDATE...CHENANGO AND CORTLAND COUNTIES...ALONG WITH DELAWARE
AND OTSEGO COUNTIES WITHIN THE PAST COUPLE HOURS...HAVE BEEN ADDED TO
THE LAKE EFFECT SNOW ADVISORY.
COMBINATION OF LAKE EFFECT AND UPSLOPE EFFECTS HAVE ANCHORED SNOW
SHOWERS IN THE HIGHER TERRAIN FOR OTSEGO AND DELAWARE
COUNTIES...WITH REPORTS OF BETWEEN 3 AND 4 INCHES ALREADY RECEIVED
AS OF A LITTLE AFTER 8 AM. MEANWHILE...NARROW AND FAIRLY INTENSE
SNOW BAND WITH UPSTREAM LAKE HURON CONNECTION...HOOKS UP TO NORTH
OF BUFFALO...THROUGH ROCHESTER...INTO NORTHERN CORTLAND/CHENANGO
COUNTIES. A SECOND BAND...WITH GEORGIAN BAY-LAKE ONTARIO
CONNECTION...IS BEGINNING TO BREAK LAKE-TO-LAKE CONNECTION
UPSTREAM...YET REMAINS FAIRLY STOUT IN ONONDAGA-MADISON COUNTIES.
WITH PASSAGE OF SHORTWAVE THE NEXT SEVERAL HOURS...BOTH OF THESE
BANDS WILL SHIFT SOUTH TO YIELD ADDITIONAL SNOWFALL FOR CHENANGO-
CORTLAND COUNTIES ON TOP OF WHAT HAS ALREADY OCCURRED...AS WELL AS
OTSEGO/DELAWARE WITH AID OF UPSLOPE ENHANCEMENT. SOUTH OF THE
ADVISORY ZONES...SQUALLS WILL OCCUR YET WILL BE TRANSIENT...AND
THUS WITH SNOW TOTALS BELOW ADVISORY CRITERIA.
WE ARE EXPECTING 3 TO 6 INCHES TOTAL SNOW IN THE ADVISORY
AREA...WITH HIGHER ELEVATIONS OF ONEIDA AND OTSEGO COUNTIES
PUSHING INTO 5 TO 7 INCHES RANGE...BEFORE THE SNOW SHOWERS
DIMINISH THIS EVENING. POPS AND SNOW AMOUNTS WERE ADJUSTED...TO
REFLECT UPDATES AS DESCRIBED ABOVE...BASED ON EXPECTED EVOLUTION
OF LAKE EFFECT BANDS THROUGH THE DAY.
PREVIOUS DISCUSSION...
MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING
ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA
COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO
A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS
COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO
THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE
WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW
AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY
SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF
DURING THE DAY.
CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL
PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY
SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN
TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY
CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY
NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT
AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF
SNOW LOOKS LIKE A GOOD BET.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION
WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS
IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK.
TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER
MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT
WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR
ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A
WEAK AND DRY COLD FNT LATER MON OR EARLY TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT
WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM
THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY.
MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD
NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY...
PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK...
POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON
WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN...
ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION
EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY
A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER
WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF
INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD
THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE-
DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY
UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM
COULD END AS SOME SNOW SHOWERS ON THURSDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT
THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR...
WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC
FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR
HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL
BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25
KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE
EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT
FLURRIES AT AVP.
NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH
MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND
INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR
VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING...
ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS
WITH A FEW GUSTS TO 25 KTS.
.OUTLOOK...
SUN/MON/TUE...MAINLY VFR.
WED...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ009-018-036-037-044>046-057.
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/MDP
SHORT TERM...DGM
LONG TERM...HEDEN/MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
849 AM EST SAT FEB 25 2012
.SYNOPSIS...
A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES
WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA
TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING
CLEARING SKIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
845 AM UPDATE...DELAWARE AND OTSEGO COUNTIES HAVE BEEN ADDED TO
THE LAKE EFFECT SNOW ADVISORY. COMBINATION OF LAKE EFFECT AND
UPSLOPE EFFECTS HAVE ANCHORED SNOW SHOWERS IN THE HIGHER
TERRAIN...WITH REPORTS BETWEEN 3 AND 4 INCHES ALREADY RECEIVED. SO
WE ARE EXPECTING 4 TO 6 INCHES TOTAL THERE TODAY BEFORE THE SNOW
SHOWERS DIMINISH THIS EVENING. GENERAL IDEA OF FORECAST IS ON
TRACK...THOUGH POPS AND SNOW AMOUNTS WERE ALSO ADJUSTED AS NEEDED
BASED ON EXPECTED EVOLUTION OF LAKE EFFECT BANDS THROUGH THE DAY.
PREVIOUS DISCUSSION...
MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING
ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA
COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO
A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS
COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO
THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE
WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW
AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY
SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF
DURING THE DAY.
CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL
PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY
SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN
TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY
CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY
NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT
AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF
SNOW LOOKS LIKE A GOOD BET.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION
WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS
IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK.
TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER
MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT
WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR
ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A
WEAK AND DRY COLD FNT LATER MON OR EARLY TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT
WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM
THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY.
MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD
NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY...
PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK...
POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON
WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN...
ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION
EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY
A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER
WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF
INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD
THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE-
DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY
UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM
COULD END AS SOME SNOW SHOWERS ON THURSDAY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT
THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR...
WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC
FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR
HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL
BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25
KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE
EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT
FLURRIES AT AVP.
NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH
MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND
INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR
VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING...
ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS
WITH A FEW GUSTS TO 25 KTS.
.OUTLOOK...
SUN/MON/TUE...MAINLY VFR.
WED...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ009-018-036-037-046-057.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/MDP
SHORT TERM...DGM
LONG TERM...HEDEN/MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BUFFALO NY
759 AM EST SAT FEB 25 2012
.SYNOPSIS...
COLDER AIR BUILDING ACROSS THE EASTERN GREAT LAKES WILL CONTINUE TO
GENERATE LAKE EFFECT SNOW TODAY. HIGH PRESSURE BUILDING EAST FROM
THE OHIO VALLEY WILL ALLOW THE LAKE SNOWS TO DIMINISH
TONIGHT...FOLLOWED BY SOME SUNSHINE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LAKE EFFECT SNOW ADVISORIES/WARNINGS REMAIN IN EFFECT AS OUTLINED
BELOW. THE WINTER STORM WARNING FOR JEFFERSON COUNTY HAS BEEN
CANCELLED.
AREA RADARS HAVE SHOWN A DRAMATIC DECREASE IN SNOW COVERAGE EAST OF
LAKE ONTARIO DURING THE PAST FEW HOURS. IT SEEMS THAT MOST OF THE
DEEPER SYNOPTIC SCALE MOISTURE HAS SHIFTED EAST WITH THE DEEP LOW
THAT IS NOW CENTERED OVER THE CANADIAN MARITIMES. THE STRONG
WESTERLY WINDS HAVE ALSO REDUCED THE RESIDENCE OVER LAKE
ONTARIO...WHICH HAS FURTHER REDUCED THE INTENSITY OF THE SNOWFALL.
THE HRRR WHICH HAS PICKED UP THESE TRENDS DOES HINT AT THE
POSSIBILITY OF MORE SNOW SETTING UP OVER OSWEGO COUNTY DURING THE
AFTERNOON. THEREFORE...PLAN TO LEAVE UP THE LAKE EFFECT SNOW WARNING
THAT IS IN PLACE THERE. UPSTREAM CONNECTIONS TO GEORGIAN BAY AND
LAKE ONTARIO HAVE ALLOWED THE NARROW SNOW BANDS OVER THE WESTERN AND
CENTRAL PART OF THE LAKE TO REMAIN INTACT.
OFF LAKE ERIE...THE CONNECTION TO LAKE HURON AND THE PERSISTENT
UPSLOPE FLOW HAS KEPT THE SNOW BANDS INTACT ACROSS THE SOUTHERN
TIER. THESE BANDS WILL HOLD TOGETHER UNTIL THE LOW LEVEL MOISTURE
BEGINS TO DECREASE LATER THIS AFTERNOON AND THE INVERSION LOWERS.
THEREFORE...THE LAKE EFFECT SNOW ADVISORY WILL REMAIN IN EFFECT.
TONIGHT...A RAPID DECREASE IN SYNOPTIC MOISTURE AND LOWERING
INVERSION HEIGHTS WILL HELP LINGERING LAKE SNOWS TO TAPER OFF AND BE
MOSTLY OVER BY 12Z SUNDAY.
WESTERLY WINDS WILL CONTINUE TO GUST OVER 30 MPH FOR MOST OF THE
DAY. THIS WILL LEAD TO FREQUENT WHITEOUTS IN THE HEAVIER LAKE SNOW
AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A HIGH PRESSURE RIDGE WILL BUILD ACROSS THE REGION ON SUNDAY. LIGHT
SNOW SHOWERS OR FLURRIES MAY LINGER SOUTHEAST OF LAKE ONTARIO SUNDAY
MORNING...BUT THESE SHOULD END BY AFTERNOON AS WINDS DIMINISH AND
SHIFT. OTHERWISE...EXPECT A CLEARING TREND FOR THE AFTERNOON...WITH
HIGHS GENERALLY IN THE LOWER 30S IN MOST LOCATIONS...A BIT COOLER
TOWARD THE NORTH COUNTRY.
ON SUNDAY NIGHT...THE HIGH WILL SLIDE OFF TO THE EAST...AS A WEAK
AREA OF LOW PRESSURE TRACKS ACROSS THE UPPER LAKES. THIS WILL LIFT A
WEAK WARM FRONT ACROSS THE REGION OVERNIGHT. THERE WILL BE AN AREA
OF WEAK WARM AIR ADVECTION IN THE MID-LEVELS...WHICH MAY BRING A
BRIEF PERIOD OF FLURRIES AS IT LIFTS ACROSS THE REGION FROM THE
SOUTHWEST TO NORTHEAST. THE BEST CHANCE FOR ANYTHING MEASURABLE WILL
LATE SUNDAY NIGHT BE EAST OF LAKE ONTARIO...WHICH IS CLOSEST TO THE
TRACK OF THE LOW.
THE LOW AND ASSOCIATED SHORTWAVE WILL PASS TO THE NORTH OF THE
REGION ON MONDAY. FOR MOST LOCATIONS...THIS LOW WILL BE FAR ENOUGH
TO THE NORTH THAT MONDAY WILL REMAIN DRY...WITH NOTABLY WARMER
CONDITIONS...AND A MODEST SW BREEZY. HIGHS SHOULD BE QUITE A BIT
ABOVE NORMAL...WITH TEMPERATURES LIKELY TO CLIMB WELL INTO THE 40S
IN MOST LOCATIONS. HOWEVER...NOTED THAT THE UKMET/EUROPEAN/GGEM
MODELS TEND TO BE A BIT MORE GENEROUS WITH QPF EAST OF LAKE ONTARIO
THAN THE NAM/GFS MODELS. WITH THE SURFACE LOW AND UPPER SHORTWAVE
PASSING FAIRLY CLOSE...DO TREND POPS UP A TAD EAST OF LAKE ONTARIO.
THIS IS STILL IN THE CHANCE RANGE...WITH EITHER RAIN OR SNOW SHOWERS
A POSSIBILITY.
THE LOW WILL TRACK INTO NEW ENGLAND MONDAY NIGHT...WITH THIS
USHERING IN SLIGHTLY COLDER AIR BEHIND IT. 850 MB TEMPERATURES WILL
BE MARGINAL AT BEST FOR ANY LAKE RESPONSE...WITH AROUND -8C ACROSS
LAKE ONTARIO. CAN/T RULE OUT A BRIEF PERIOD OF LIGHT SNOW SHOWERS
EAST AND SOUTHEAST OF LAKE ONTARIO MONDAY NIGHT...BUT ANY
ACCUMULATIONS SHOULD NOT BE MUCH AT ALL.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE EXTENDED PERIOD WILL START OFF WITH AN ELONGATED RIDGE OF
CANADIAN HIGH PRESSURE SLIDING EAST ACROSS THE AREA ON TUESDAY.
COOLER AND DRIER AIR ASSOCIATED WITH THE HIGH WILL RESULT IN A
RETURN TO MORE SEASONABLE TEMPERATURES AREAWIDE...ALONG WITH DRY
CONDITIONS.
AFTER THAT...THE MEDIUM RANGE GUIDANCE IS IN RATHER GOOD AGREEMENT
THAT THE TUESDAY NIGHT THROUGH THURSDAY PERIOD WILL LIKELY FEATURE
THE APPROACH AND PASSAGE OF ANOTHER SIGNIFICANT "CUTTER" TYPE LOW
PRESSURE SYSTEM...WITH A MODEL CONSENSUS TRACKING THIS SYSTEM FROM
IOWA NORTHEASTWARD ACROSS THE CENTRAL GREAT LAKES...THEN ON INTO
QUEBEC WHILE SLOWLY FILLING. THE 00Z RUN OF THE EUROPEAN DIFFERS
FROM THIS SOLUTION...WITH A SLOWER AND COLDER SOLUTION. WITH SUPPORT
FROM PREVIOUS RUNS...AND THE 00Z GGEM...WILL CONTINUE WITH A
GFS-LIKE SOLUTION...TRENDING A TAD SLOWER AND COLDER TO BLEND WITH
THE EUROPEAN MODEL.
THIS WILL LIKELY BRING A PERIOD OF PRECIPITATION LATE TUESDAY NIGHT
AND WEDNESDAY. EXPECT MOST OF THIS TO FALL AS RAIN...EXCEPT IN THE
NORTH COUNTRY WHERE SNOW IS MORE LIKELY. TEMPERATURES WILL BE TRICKY
GIVEN UNCERTAINTY IN THE TRACK AND TIMING OF THE LOW...BUT DO FEEL
THE SOUTHERN TIER AND POSSIBLY BUFFALO/ROCHESTER WILL BREAK INTO THE
WARM SECTOR WITH TEMPERATURES IN THE MID 40S OR WARMER.
FOLLOWING THE PASSAGE OF THIS SYSTEM`S COLD FRONT WEDNESDAY
EVENING...SEASONABLY COOLER AIR WILL THEN SPREAD BACK ACROSS THE
AREA WEDNESDAY NIGHT AND THURSDAY. THIS WILL RESULT IN ANY LINGERING
WRAPAROUND PRECIPITATION CHANGING BACK TO MOSTLY SNOW SHOWERS AS THE
LOW SLOWLY LIFTS OFF INTO WESTERN QUEBEC AND AWAY FROM OUR
REGION...THOUGH BOUNDARY LAYER TEMPS COULD VERY WELL WARM UP ENOUGH
AGAIN ON THURSDAY TO ALLOW FOR SOME RAIN SHOWERS TO MIX IN ONCE
AGAIN. IN GENERAL...THE PRECIPITATION SHOULD BE LIGHT AND TEND TO
TAPER OFF FROM SOUTH TO NORTH THROUGH THURSDAY NIGHT AS THE LOW
PULLS FURTHER AWAY...WITH INCREASING RIDGING THEN RESULTING IN A
RETURN TO MAINLY DRY WEATHER FOR FRIDAY. TEMPS THROUGH THIS LATTER
HALF OF THE PERIOD WILL FALL OFF AGAIN WITH THE REINTRODUCTION OF
SOME COOLER AIR...THOUGH WILL LIKELY STILL AVERAGE OUT ABOVE NORMAL
WITH NIGHTTIME LOWS RANGING BETWEEN 20 AND 30...AND DAYTIME HIGHS
REACHING INTO THE MID AND UPPER 30S.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
WINDS GUST HAVE DIMINISHED ACROSS THE AREA FOR THE 12Z TAF PACKAGE.
NARROW BANDS OF SNOW WILL REMAIN INTACT SOUTHEAST OF BOTH LAKES
THROUGHOUT THE AFTERNOON. THIS WILL ALLOW CONDITIONS TO DROP TO IFR
WHERE THE STEADIER LAKE SNOWS PERSISTS. OTHERWISE...EXPECT MAINLY
MVFR CONDITIONS TO PREVAIL.
AS DRIER AIR WORKS INTO THE AREA TONIGHT...THE LAKE SNOWS WILL END
AND CIGS/VSBYS WILL IMPROVE TO VFR.
OUTLOOK...
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
MONDAY AND TUESDAY...VFR.
WEDNESDAY...MFR/IFR IN RAIN.
&&
.MARINE...
GALE CONDITIONS WILL DIMINISH FROM WEST TO EAST TODAY AS THE DEEP
LOW LIFTS EAST ACROSS THE CANADIAN MARITIMES. WIND AND WAVES WILL
SUBSIDE FURTHER TONIGHT AND SUNDAY AS HIGH PRESSURE BUILDS EAST
ACROSS NEW YORK STATE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ004-005-008-012-019-020-085.
LAKE EFFECT SNOW WARNING UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ006.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ020.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LOZ030.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LOZ043>045-
063>065.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LOZ042-062.
&&
$$
SYNOPSIS...TJP
NEAR TERM...TJP
SHORT TERM...APFFEL
LONG TERM...APFFEL/JJR
AVIATION...TJP
MARINE...TJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
641 AM EST SAT FEB 25 2012
.SYNOPSIS...
A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES
WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA
TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING
CLEARING SKIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING
ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA
COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO
A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS
COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO
THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE
WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW
AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY
SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF
DURING THE DAY.
CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL
PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY
SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN
TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY
CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY
NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT
AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF
SNOW LOOKS LIKE A GOOD BET.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION
WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS
IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK.
TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER
MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT
WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR
ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A
WEAK AND DRY COLD FNT LATER MON OR EARLY TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT
WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM
THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY.
MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD
NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY...
PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK...
POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON
WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN...
ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION
EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY
A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER
WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF
INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD
THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE-
DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY
UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM
COULD END AS SOME SNOW SHOWERS ON THURSDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT
THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR...
WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC
FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR
HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL
BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25
KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE
EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT
FLURRIES AT AVP.
NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH
MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND
INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR
VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING...
ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS
WITH A FEW GUSTS TO 25 KTS.
.OUTLOOK...
SUN/MON/TUE...MAINLY VFR.
WED...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ009-018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...HEDEN/MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
348 AM EST SAT FEB 25 2012
.SYNOPSIS...
A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES
WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA
TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING
CLEARING SKIES.
&&
.NEAR TERM /THROUGH TONIGHT/...
MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING
ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA
COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO
A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS
COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO
THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE
WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW
AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY
SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF
DURING THE DAY.
CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL
PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY
SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN
TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY
CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY
NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT
AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF
SNOW LOOKS LIKE A GOOD BET.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION
WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS
IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK.
TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER
MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT
WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR
ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A
WEAK AND DRY COLD FNT LATER MON OR EARLY TUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT
WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM
THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY.
MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD
NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY...
PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK...
POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON
WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN...
ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION
EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY
A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER
WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF
INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD
THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE-
DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY
UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM
COULD END AS SOME SNOW SHOWERS ON THURSDAY.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT
THE NY TAF SITES THROUGH SATURDAY. VSBYS AND CIGS WILL BE MAINLY
MVFR... WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS.
BEST CHC FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH
A CHC FOR HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z.
WINDS WILL BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING
15 TO 25 KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON.
MEANWHILE EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST
LIGHT FLURRIES AT AVP.
NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH
MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND
INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR
VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING...
ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS
WITH A FEW GUSTS TO 25 KTS.
.OUTLOOK...
SUN/MON/TUE...MAINLY VFR.
WED...IFR/MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043-
044-047-048-072.
NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
NYZ009-018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM
LONG TERM...HEDEN/MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
919 PM CST SUN FEB 26 2012
.DISCUSSION...
MAIN ISSUE FOR THE UPDATE IS HOW TO HANDLE THE CURRENT HEADLINES.
SFC LOW HAS MOVED OFF TO OVER DLH...AND NORTH WINDS HAVE CONTINUED
TO BLOW AT 15 TO 25 MPH WITH SOME GUSTS ABOVE 30 MPH. WINDS HAVE
NOT BEEN AS STRONG IN THE AREA WITH TREES IN OUR EASTERN
COUNTIES...AND RADAR AND SFC OBS SHOW THAT THE SNOW HAS PRETTY
MUCH ENDED IN THAT AREA. 00Z NAM12 AND HRRR CAPTURE WELL THE SNOW
ENDING IN THE EAST FIRST AND HANGING AROUND THE VALLEY AND FURTHER
WEST COUNTIES UNTIL AFTER 06Z. WINDS AND SNOW IN THE VALLEY HAVE
AND PARTS OF DEVILS LAKE BASIN HAVE KEPT VIS DOWN AROUND 1SM OR
LESS AT TIMES...ALTHOUGH THERE HAS BEEN SOME IMPROVEMENT. WILL
TRIM THE EASTERN COUNTIES OUT BUT KEEP THE WEST GOING FOR THE TIME
BEING. WILL KEEP AN EYE ON THE WEST AND IF IT STARTS TO SEE MORE
SNOW TAPERING OFF AND IMPROVING VISIBILBITIES BEFORE MIDNIGHT MAY
ALSO END THING EARLY.
&&
.AVIATION...
CONDITIONS HAVE IMPROVED TO VFR IN KBJI...BUT WITH A SCATTERED
LOWER DECK THINK IT WILL GO BACK DOWN TO MVFR SHORTLY. CEILINGS
AND VIS AROUND 3SM WITH LIGHT SNOW HAVE KEPT REST OF THE TAF SITES
MOSTLY MVFR...ALTHOUGH A FEW LOCATIONS HAVE SEEN DIPS DOWN TO IFR.
CEILINGS AND VIS WILL GRADUALLY IMPROVE AFTER 06Z AND CONDITIONS
SHOULD BECOME VFR ACROSS THE ENTIRE FORECAST AREA AFTER 15Z OR SO.
NORTHERLY WINDS WITH GUSTS OVER 20 KTS WILL DECREASE BELOW 10 KTS
AND BECOME SOUTHERLY LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 308 PM CST SUN FEB 26 2012/
SHORT TERM...
A VERY CHALLENGING FORECAST THIS AFTERNOON...WITH CURRENT SYSTEM
SLOWLY WINDING DOWN AND A MAJOR STORM ON THE HORIZON FOR TUE/WED.
MODELS ARE IN PRETTY GOOD OVERALL AGREEMENT...AND WILL SIDE WITH
THE CONSISTENT GFS.
FOR TONIGHT...EXPECT SOME BLOWING AND DRIFTING SNOW THROUGH THIS
EVENING WITH SOME LIGHT SNOW IN WRAPAROUND DEFORMATION ZONE.
ADDITIONAL ACCUMULATIONS SHOULD BE AN INCH OR LESS. WE WILL KEEP
ALL CURRENT HEADLINES IN TACT WITH LOW VSBYS STILL IN OPEN
COUNTRY...AND THE EVENING CREW CAN RE-EVALUATE TO SEE IF HEADLINES
CAN BE CANCELLED EARLY. WINDS SHOULD QUICKLY SUBSIDE LATER
TONIGHT...WITH PERHAPS SOME CLEARING MOVING INTO THE FAR WEST LATE.
ON MONDAY...THIS SHOULD BE A QUIET DAY WITH SFC HIGH PRESSURE
MOVING INTO THE EAST BY MONDAY EVENING. TEMPS WILL BE BELOW NORMAL
GIVEN FRESH SNOW AND LIMITED MIXING...ALTHOUGH LATE FEB INSOLATION
SHOULD HELP WARM THINGS UP A BIT.
ON MONDAY NIGHT...AN INITIAL BAND OF ISENTROPIC LIFT AND WARM
ADVECTION COULD SPREAD SOME LIGHT SNOW THROUGH ALL BUT THE FAR
NORTH. HAVE INCLUDED SOME LOW POPS TO ACCOUNT FOR THIS INITIAL BAND
OF LIGHT SNOW NOT ASSOCIATED WITH THE MAIN LOW.
FOR TUE/WED...A COLORADO LOW WILL TRACK INTO SOUTHERN MN BY WED
AFTERNOON. THIS WILL SPREAD PLENTIFUL MOISTURE INTO MOST OF THE
REGION EXCEPT THE FAR NORTH...WITH PWATS OF AN INCH IN SOUTHERN
IOWA. FORCING FOR ASCENT WILL BE STRONG WITH DEEP LAYERED OMEGA
AND Q VECTOR CONVERGENCE. THERE WILL BE A 50KT 850MB EASTERLY JET
AND STRONG MID LEVEL CONVERGENCE OVER THE AREA. HEAVY SNOW WILL
LIKELY RESULT IN AT LEAST THE SOUTHERN AREAS WITH A FOOT OR MORE
POSSIBLE HERE. TO THE NORTH...EXPECT A SHARP CUTOFF TO THE SNOW
WITH LITTLE TO NO SNOW NEAR THE CANADIAN BORDER. WINDS WILL BECOME
QUITE STRONG WITH ABOUT 40KT TO MIX FROM 925MB...ALTHOUGH THE
EASTERLY COMPONENT WOULD NOT MEAN THE BEST WIND POTENTIAL. WHEN
THE WIND COUPLES WITH THE POTENTIAL HEAVY SNOW...BLIZZARD
CONDITIONS MAY RESULT. IT IS INTERESTING TO NOTE THAT THE SREF MODEL AND
NOW THE 12Z ECMWF DOES BRING SATURATION AND SNOW MUCH FURTHER
NORTH...SO WE WILL SEE JUST HOW FAR NORTH THE SNOW BAND GOES. FOR
NOW WE ARE CONFIDENT IN POTENTIAL BLIZZARD CONDITIONS FROM EDDY
COUNTY TO GRAND FORKS COUNTY TO CLEARWATER COUNTY AND POINTS
SOUTH...AND WE HAVE ISSUED A BLIZZARD WATCH HERE FOR 12Z TUE- 00Z
WED. WE WILL NEED TO MONITOR ANY SUBTLE TRACK DEVIATIONS WITH THIS
SYSTEM...BUT IT APPEARS THE BIGGEST WINTER STORM OF THE SEASON IS
ON TRACK WITH SIGNIFICANT SNOW AND BLOWING SNOW CREATING HAZARDOUS
CONDITIONS TUESDAY AND WEDNESDAY.
LONG TERM (THU-SUN)...
TUE/WED STORM SYSTEM SHOULD BE EAST OF THE AREA BY THE BEGINNING OF
THE LONG TERM FORECAST. HOWEVER THERE APPEARS TO BE VERY LITTLE
BREAK IN THE PARADE OF WEATHER SYSTEMS THAT LOOK TO AFFECT THE
NORTHERN PLAINS. THE NEXT UPPER LOW MOVES DOWN THE NORTHWEST FLOW
INTO THE NORTHERN PLAINS ON FRI/SAT. NOT LOOKING LIKE MUCH MORE THAN
LIGHT SNOW OR FLURRIES EARLY ON THU BEFORE CHANCES START TO INCREASE
MORE SUBSTANTIALLY BY THU AFTERNOON INTO FRIDAY. THERE COULD EVEN BE
WRAPAROUND PCPN OCCURRING INTO FRI NIGHT/SAT. THIS IS NOT LOOKING
LIKE A BIG TIME SNOW PRODUCER BUT RATHER A STEADY LIGHT SNOW OVER A
LONG DURATION OF TIME. THINGS SHOULD IMPROVE ON SUNDAY BUT
OPERATIONAL MODELS START TO DIVERGE FAIRLY SIGNIFICANTLY ON TRENDS
BY THIS POINT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR NDZ024-026>030-038-039-049-052-053.
WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...BLIZZARD WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR MNZ001>003-013>016-022>024-027>032-040.
WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR MNZ001>004-007-
029.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
349 PM EST SAT FEB 25 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE OVER THE REGION WILL QUICKLY SWING EAST
OF THE AREA EARLY TONIGHT...AND RIDGING WILL BUILD OVER THE AREA.
HIGH PRESSURE OVER THE AREA EARLY SUNDAY WILL WEAKEN AS LOW
PRESSURE MOVES OVER THE CENTRAL GREAT LAKES. THIS LOW WILL PASS
NORTH OF THE AREA ON MONDAY...FOLLOWED BY ANOTHER AREA OF HIGH
PRESSURE FOR TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST RADAR SHOWING DISORGANIZED AREA OF LAKE EFFECT SNOW SHOWERS
ACROSS MUCH OF THE EASTERN 2/3 OF THE FORECAST AREA THIS
AFTERNOON. GIVEN LATEST OBS ACROSS THE AREA COMBINED WITH
RADAR...WILL NOT MAKE ANY CHANGES TO HEADLINES GOING INTO THE
EVENING HOURS...AND WILL KEEP EARLY MENTION OF LIKELY TO
CATEGORICAL POPS ACROSS THIS AREA. ACROSS WESTERN AREAS MENTION
CHC AND SLGT CHC ACROSS THE FAR WEST.
WITH THE FORECAST FOR TONIGHT BEGINNING AT 7PM...ACCUMS MENTIONED
FOR TONIGHT WILL BE RATHER LIGHT AS THE BULK OF THE MORE
SIGNIFICANT SNOWFALL IS EXPECTED TO BE DIMINISHING BY THAT POINT.
WITH LAKE EFFECT SNOW SHOWERS CONTINUING TO BECOME MORE
DISORGANIZED AND MOVING THINKING ANOTHER INCH OR TWO ACROSS MOST
LOCATIONS.
AFTER MIDNIGHT RIDGING BUILDING INTO THE AREA WILL CAUSE SNOW
SHOWERS TO DIMINISH FURTHER TO PERHAPS SOME LINGERING FLURRIES
THROUGH AROUND 3AM AT THE LATEST ACROSS THE FAR EAST. LOCAL MODELS
AS WELL AS THE HRRR HAVE HANDLED THIS SITUATION REASONABLY WELL
THIS AFTERNOON...SO THOSE ALONG WITH MAV AND MET POPS INDICATING
LITTLE FOR SNOW SHOWERS LATE TONIGHT.
WENT SLIGHTLY WARMER THAN GUIDANCE ON TEMPS MAINLY ACROSS THE
EAST. WINDS WILL REMAIN UP A BIT OVERNIGHT COMBINED WITH CLOUD
COVER AND LINGERING SNOW SHOWERS/FLURRIES. ACROSS THE WEST SOME
CLEARING MAY HELP BRING TEMPS DOWN A BIT BUT WINDS MAY STILL BE A
FACTOR THERE. OVERALL WENT MID 20S ALONG THE LAKESHORE...LOWER 20S
ACROSS THE EAST TO PERHAPS UPPER TEEN TO AROUND 20 FOR WESTERN
AREAS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
THE NEXT FEW DAYS WILL CONTAIN PROGRESSIVE FEATURES MOVING ACROSS
THE REGION. HIGH PRESSURE WILL RIDGE INTO THE AREA FOR SUNDAY
ALLOWING FOR SOME SUNSHINE ACROSS THE AREA AND MODERATING TEMPS.
WILL SEE HOW WELL NE OH/NW PA LOCATIONS MODERATE...SO DIDN/T GO
QUITE AS WARM THERE. THINKING MOST LOCATIONS SHOULD MODERATE TO
NEAR 40 OR BETTER ESPECIALLY ACROSS THE WEST. MEANWHILE MODELS
FAIRLY SIMILAR WITH LOW PRESSURE APPROACHING THE CENTRAL GREAT
LAKES THROUGH SUNDAY. THIS MAY SPREAD SOME CLOUDS INTO THE
NORTHERN HALF OF THE AREA SUNDAY...BUT OTHERWISE DRY.
LOW PRESSURE MOVES NORTH OF THE AREA SUNDAY NIGHT AND MONDAY. BULK
OF ENERGY AND PRECIP WITH THE LOW EXPECTED TO REMAIN NORTH OF THE
FORECAST AREA WITH A WEAK COLD FRONT PUSHING THROUGH THE AREA
MONDAY. LITTLE CHANGE OF AIRMASS EXPECTED WITH THIS FRONT. HIGH
PRESSURE BUILDS IN MONDAY NIGHT AND THEN QUICKLY MOVES EAST OF THE
AREA TUESDAY. GFS AND ECMWF SHOWING CLOUDS BUILDING IN AHEAD OF
THE NEXT LOW THROUGH TUESDAY MORNING. KEPT POPS LOW ACROSS THE
AREA EARLY TUESDAY...BUT THEN MOST MODELS INDICATING RAIN MOVING
INTO THE AREA BY THE END OF THE DAY. WITH THAT INCREASE POPS TO
HIGH CHC/LIKELY ACROSS MUCH OF THE AREA.
TEMPS MONDAY NIGHT WILL BE TRICKY GIVEN THE POTENTIAL FOR SOME
RADIATING WITH HIGH PRESSURE OVERHEAD. GFS STRONGER WITH WAA ON
TUESDAY AND TUESDAY NIGHT PUSHING WARM FRONT WELL NORTH OF THE
AREA. MEANWHILE ECMWF SHOWING WARM FRONT STILL ACROSS THE AREA
TUESDAY NIGHT SUGGESTING COOLER TEMPS. FOR NOW BLENDED THE TWO
WITH TEMPS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY WILL START OFF WARM (TEMPERATURES IN THE 50S) AS WE LIE IN
THE WARM SECTOR OF A LOW PRESSURE SYSTEM TRACKING THROUGH THE
CENTRAL GREAT LAKES. MODELS CONTINUE TO ADVERTISE SOME DIFFERENCES
IN TIMING REGARDING THE PRECIPITATION ALONG THE OCCLUDED FRONT AND
WILL MAINTAIN LIKELY POPS INTO WEDNESDAY MORNING WITH A DRYING TREND
FROM WEST TO EAST DURING THE AFTERNOON. THE CHANCE OF RAIN AND SNOW
SHOWERS WILL CONTINUE INTO WEDNESDAY NIGHT ALTHOUGH TEMPERATURES
BEHIND THE COLD FRONT WILL NOT BE COOL ENOUGH FOR LAKE EFFECT SNOW
TO DEVELOP.
A DRYING TREND WILL OCCUR ON THURSDAY AS HIGH PRESSURE BUILDS
OVERHEAD WITH ANOTHER OPPORTUNITY FOR SHOWERS ON FRIDAY AS THE NEXT
LOW PRESSURE SYSTEM APPROACHES THE REGION.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
DOMINANT LAKE EFFECT SNOW BAND HAS BECOME MORE CELLULAR IN NATURE AS
IT SLOWLY PUSHES SOUTH ACROSS LAKE ERIE. THIS SOUTHERN TREND IS
EXPECTED TO CONTINUE THIS AFTERNOON AS WINDS ALOFT VEER TO MORE
NORTHWESTERLY. YNG/CLE/ERI WILL SEE AN INCREASE IN SNOW SHOWERS
THROUGH ROUGHLY 21Z AND MAY SEE VISIBILITIES DROP BELOW 1 MILE IF ANY
OF THE HEAVIER SQUALLS IMPACT THE AIRPORTS. FURTHER INLAND AT
TOL/MFD/CAK SNOW SHOWERS WILL BE MUCH LIGHTER IN NATURE BUT COULD
BRIEFLY DROP VISIBILITIES INTO THE IFR RANGE THIS AFTERNOON. LAKE
EFFECT SNOW SHOWERS ARE EXPECTED TO DECREASE IN INTENSITY LATE THIS
AFTERNOON AS DRIER AIR PUSHES SOUTH ACROSS LAKE ERIE. CLOUDS WILL
GRADUALLY SCATTER OUT FROM WEST TO EAST DURING THE OVERNIGHT HOURS
AS A RIDGE BUILDS OVERHEAD. GUSTY WESTERLY WINDS WILL CONTINUE
THROUGH AROUND 22Z WITH WINDS BECOMING LIGHT TONIGHT AS THEY SHIFT
AROUND TO THE SOUTH. SOUTHERLY WINDS WILL BECOME BREEZY BY SUNDAY
AFTERNOON.
OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND
CONTINUE AT TIMES THROUGH THURSDAY.
&&
.MARINE...
WINDS THIS AFTERNOON RANGE FROM NEAR 20 KNOTS ON THE WEST END OF
LAKE ERIE TO NEAR 30 KNOTS THE EAST END OF THE LAKE. WILL MAINTAIN
THE SMALL CRAFT ADVISORIES WHICH CONTINUE ON THE WEST END OF THE
LAKE INTO THIS EVENING AND THROUGH 4 AM ON THE EAST END OF THE LAKE.
WINDS WILL DECREASE CONSIDERABLY OVERNIGHT AS THE RIDGE BUILDS WITH
WAVES BEING A LITTLE SLOWER TO SUBSIDE.
A WARM FRONT WILL LIFT NORTH ACROSS THE LAKE ON SUNDAY WITH
CONDITIONS BECOMING MORE STABLE DESPITE STRONG WINDS IN THE COLUMN
ALOFT. CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY ON THE WESTERN
END OF THE LAKE BY SUNDAY NIGHT WITH WINDS INCREASING ON THE EASTERN
HALF OF THE LAKE BEHIND A COLD FRONT ON MONDAY. SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED EAST OF CLEVELAND AND WE MAY EVEN
APPROACH GALES FOR A BRIEF WHILE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
OHZ012-013-023-089.
LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR
OHZ014.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ001.
LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LEZ142>144.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ145-
146.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1035 AM EST SAT FEB 25 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE WELL NORTHEAST OF THE AREA TODAY. A TROUGH
OVER THE REGION WILL ROTATE SOUTH OF THE AREA LATER TODAY. HIGH
PRESSURE WILL QUICKLY BUILD EAST TONIGHT OVER THE REGION AND THEN
CAROLINA COAST BY SUNDAY AFTERNOON. LOW PRESSURE WILL MOVE EAST
ACROSS THE NORTHERN GREAT LAKES SUNDAY NIGHT FORCING A WEAK WARM
FRONT TO MOVE THROUGH THE AREA. A COLD FRONT WILL MOVE EAST ACROSS
THE AREA MONDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HEAVY LAKE EFFECT SNOW BAND SETTING UP FROM LAKE COUNTY STRETCHING
INTO ASHTABULA COUNTY AND INTERIOR NW PA THIS MORNING. GIVEN SNOW
OBSERVER REPORTS THIS MORNING COMBINED WITH POTENTIAL FOR
ADDITIONAL LAKE EFFECT SNOW THIS AFTERNOON HAVE GONE WITH AN
UPGRADE TO WARNING FOR INTERIOR NW PA AS WELL AS INTERIOR ASHTABULA
COUNTY. ADVISORIES FOR LAKESHORE ZONES AS WELL AS TRUMBULL COUNTY.
ALL LE SNOW HEADLINES THROUGH 10PM TONIGHT. CAN SEE SNOW
DIMINISHING A BIT AFTER 7-8PM TONIGHT BUT WILL KEEP FOR A FEW MORE
HOURS.
OVERALL...HEAVIER BAND SETTING UP FROM LAKE COUNTY INTO ASHTABULA
THIS MORNING. OBS ACROSS NW PA INDICATING SNOW CONTINUING THERE
ALSO IN THE UPSLOPE FLOW DESPITE WEAK APPEARANCE ON RADAR. LOCAL
MODELS AS WELL AS HRRR INDICATING THIS CONTINUING THROUGH AT LEAST
EARLY TO MID AFTERNOON. LATEST SURFACE OBS SHOWING DECENT SFC
CONVERGENCE ACROSS NE OH AND NW PA WITH WSW WINDS ONSHORE OF
THE LAKE WITH WSW WINDS OVER LAND. BUFKIT SHOWING GOOD MOISTURE
AND NOT MUCH FOR AN INVERSION UNTIL THIS EVENING. ALL COMBINED
WERE REASONS FOR THE UPGRADE AND EXPANSION OF THE
ADVISORIES/WARNINGS.
BASED ON MODELS AND AND LATEST ANALYSIS EXPECTING EVOLUTION OF THE
LAKE EFFECT SNOW BANDS TO GRADUALLY SAG SOUTHWARD INTO
GEAUGA...CUYAHOGA AND CENTRAL TRUMBULL COUNTIES LATER THIS
AFTERNOON...THEN EFFECTS CONTINUE TO EXPAND TO LORAIN...MEDINA
SUMMIT AND PORTAGE COUNTIES ALSO LATER IN AFTERNOON. MOST ARE
TRYING TO INDICATE BY THIS TIME THE BANDS WILL NOT BE AS INTENSE
AS THIS MORNING SO WILL KEEP THOSE MENTIONED COUNTIES OUT OF
ADVISORY CRITERIA SNOW. HOWEVER...BECAUSE OF THIS EXPANDED THE
CATEGORICAL POPS ACROSS MUCH OF THE EASTERN HALF OF THE FORECAST
AREA INTO EARLY TONIGHT.
MADE MINOR ADJUSTMENTS DOWNWARD FOR MAX TEMPS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE QUICKLY MOVES EAST INTO THE REGION FROM THE WEST AND
THIS SHOULD BRING A FAIRLY RAPID END TO THE LAKE EFFECT SNOW
SHOWERS. FAIR WEATHER WILL DOMINATE THE FORECAST AREA INTO TUESDAY
EVEN THOUGH LOW PRESSURE MOVES BY TO THE NORTH OF THE REGION. MODELS
SUGGEST MOISTURE WILL BE VERY LIMITED TO THE SOUTH OF THE FEATURE SO
WILL KEEP CURRENT FORECAST OF DRY WEATHER GOING. AFTER STORM SYSTEM
MOVES BY TO THE EAST...YET ANOTHER HIGH PRESSURE BUILDS EAST INTO
THE REGION FOR TUESDAY KEEPING THE FAIR WEATHER HOLDING STRONG.
THE NEXT CHANCE OF PRECIPITATION WILL NOT ARRIVE UNTIL TUESDAY NIGHT
WHEN THE NEXT FAIRLY LARGE STORM SYSTEM APPROACHES FROM THE WEST.
THE DIFFERENCE MAKER IS THIS STORM SYSTEM HAS A BIT MORE PUNCH
ASSOCIATED WITH IT AS UPPER LEVEL TROUGH DIGS INTO THE CENTRAL
UNITED STATES. THE STORM SYSTEM WILL ALSO TAP INTO THE GULF OF
MEXICO STREAMING MOISTURE INTO THE REGION. WARM FRONT LIFTS NORTH
OVER THE FORECAST AREA BY TUESDAY NIGHT AND PLACES THE FORECAST AREA
IN THE WARM SECTOR...AND PROBABLY THE WARMEST AIR OF THE SEASON SO
FAR. DEPENDING ON TIMING...WE COULD VERY WELL SEE THE LOWS OCCURRING
SHORTLY AFTER SUNSET TUESDAY NIGHT WITH WARMING TAKING PLACE
OVERNIGHT. FOR NOW WILL GO WITH THE DIURNAL TREND IN CASE WARM FRONT
SLOWS IN FORWARD PROGRESS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
ONLY MINOR CHANGES TO THE LONG TERM TODAY. THE NEW ECMWF IS A TAD
SLOWER THAN THE 00Z GFS TRACKING A STRONG SURFACE LOW ACROSS THE
AREA ON WEDNESDAY. THE GFS TRIES TO DRY SLOT THE AREA BY MIDDAY BUT
THE ECMWF KEEPS THE MAIN PRECIP SHIELD OVER THE AREA THROUGH LATE
AFTERNOON. WILL JUST LEAVE HIGH POPS IN ALL DAY FOR THE TIME
BEING. SOME COLD AIR ADVECTION PRECIP IS LIKELY BEHIND THIS SYSTEM
WEDNESDAY NIGHT INTO THURSDAY. RIDGING WILL OCCUR LATE THURSDAY
INTO MIDDAY FRIDAY WITH DRY WEATHER EXPECTED. ANOTHER STORM WILL
QUICKLY APPROACH FROM THE WEST ON FRIDAY AND WILL NEED PRECIP
CHANCES FOR THE ENTIRE AREA BY THE END OF THE DAY. SO FAR...THE
GUIDANCE IS PRETTY SIMILAR WITH THIS SCENARIO. WEDNESDAY WILL BE
THE WARMEST DAY OF THE PERIOD WITH TEMPS A GOOD 10 TO 15 DEGREES
ABOVE NORMAL. SEASONABLE VALUES ARE EXPECTED ON THURSDAY WITH
ANOTHER WARM UP EXPECTED FOR FRIDAY.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
A PERSISTENT BAND OF LAKE EFFECT SNOW CONTINUES TO PASS JUST TO
THE N OF KCLE TO NEAR KYNG. THIS BAND HAS FINALLY STARTED TO SHIFT
NE AND SHOULD LIFT N OF KYNG SHORTLY. OTHER BANDS OF LIGHT SNOW
CONTINUE TO AFFECT THE OTHER TAF SITES. THIS WILL BE THE TREND FOR
THE DAY WITH OCCASIONAL BANDS OF SNOW HITTING THE TAFS. KERI
SHOULD GET INTO THE ACTION IN A COUPLE OF HOURS. THINGS BEGIN TO
DRY OUT TOWARD EVENING AND EXPECT VFR WEATHER ALL AREAS BY 00Z.
SOME CLEARING LIKELY IN THE WEST THIS EVENING. EXPECT CIGS AND
VSBYS TO BE MAINLY MVFR THROUGH MID AFTERNOON WITH BRIEF IFR
CONDITIONS WITH THE HEAVIER BANDS. GUSTY W FLOW WILL GRADUALLY
DIMINISH TODAY. GUSTS OF 25 TO 30 KNOTS POSSIBLE AT LEAST THROUGH 18Z.
OUTLOOK...PERIODS OF NON-VFR LIKELY SATURDAY THROUGH SATURDAY
NIGHT.
&&
.MARINE...
WINDS CONTINUE TO SLOWLY DIMINISH BUT STILL GETTING SOME GALES ON
THE EAST HALF. WILL LET THE GALE WARNING GO AS IS AND WILL LIKELY
NEED SMALL CRAFTS THROUGH THE AFTERNOON. SPEEDS SHOULD CONTINUE TO
DIMINISH TODAY. HIGH PRESSURE WILL PASS TO THE SOUTH OF THE LAKE
TONIGHT AND SUNDAY MORNING CAUSING THE FLOW TO TURN TO THE SW BY MID
MORNING ON SUNDAY. INCREASING S TO SW FLOW IS EXPECTED SUNDAY NIGHT
INTO MONDAY. A COLD FRONT WILL CROSS THE LAKE ON MONDAY CAUSING THE
FLOW TO BECOME W TO NW. ANOTHER HIGH WILL MOVE OVER THE LAKE MONDAY
NIGHT CAUSING A PERIOD OF LIGHT AND VARIABLE FLOW. A WARM FRONT
WILL LIFT NORTH ACROSS THE LAKE EARLY WEDNESDAY WITH INCREASING S TO
SW FLOW BEHIND THE FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
OHZ012-013-023-089.
LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR
OHZ014.
PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
PAZ001.
LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR
PAZ002-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LEZ142>144-164.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ147>149.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ145-
146.
&&
$$
SYNOPSIS...LOMBARDY/ABE
NEAR TERM...ABE
SHORT TERM...LOMBARDY
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 PM EST SAT FEB 25 2012
.SYNOPSIS...
A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN
THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN
MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT
WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE
NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL
TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE
BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID-
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO
COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING
OFF LATER TODAY AND THIS EVE.
LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST
MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND
MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE
HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING
DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO
LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME
WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR
THE ORGANIZATION WILL BECOME.
OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER
NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO
SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A
LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS
HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER
INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND
FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET.
LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO
CLIMO NORMS.
HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY
GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE
AND IF ANY RECUR THEY WILL BE ISOLATED.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE
ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS
THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON
EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG
BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES
HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST
COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH.
VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN
FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE
NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES.
THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND
PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE
REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN
PLAINS AND ACROSS THE UPPER GLAKES REGION.
THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND
OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE
NORTH OF LAKE ONTARIO.
TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN
AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE
NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER
SUSQ VALLEY.
ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR
WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE
UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER
STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH
INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC
MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE
GFS OR GEFS SOLUTIONS.
EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY
ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA
COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN
CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM
AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER
GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH
ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET
BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC
SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME
ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND
EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW
INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV
AND KIPT.
MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH.
NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY
CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE
REGION.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
SQUALLS AND HIGH WINDS STILL A PROBLEM...WENT WITH MORE ADVERSE
CONDITIONS IN THE 21Z TAFS FOR A FEW MORE HOURS.
EARLIER DISCUSSION BELOW.
HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR
CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS
INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE.
ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY
EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN AREAS
TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR WHITEOUT
CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE REGION.
EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND
BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT.
HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING
AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW
SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING.
MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY
MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR
BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON
AS HIGH PRESSURE MOVES OVER THE STATE.
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY
NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER
LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR
TRACK WED-THUR.
OUTLOOK...
MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS.
TUE...VFR. RESTRICTIONS PSBL TUE NGT.
WED/THU...RESTRICTIONS LKLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
404 PM EST SAT FEB 25 2012
.SYNOPSIS...
A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN
THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN
MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT
WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE
NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL
TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE
BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID-
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO
COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING
OFF LATER TODAY AND THIS EVE.
LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST
MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND
MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE
HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING
DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO
LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME
WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR
THE ORGANIZATION WILL BECOME.
OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER
NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO
SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A
LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS
HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER
INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND
FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET.
LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO
CLIMO NORMS.
HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY
GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE
AND IF ANY RECUR THEY WILL BE ISOLATED.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE
ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS
THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON
EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG
BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES
HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST
COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH.
VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN
FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE
NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES.
THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND
PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE
REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN
PLAINS AND ACROSS THE UPPER GLAKES REGION.
THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND
OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE
NORTH OF LAKE ONTARIO.
TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN
AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE
NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER
SUSQ VALLEY.
ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR
WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE
UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER
STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH
INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC
MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE
GFS OR GEFS SOLUTIONS.
EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY
ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA
COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN
CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM
AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER
GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH
ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET
BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC
SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME
ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND
EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW
INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV
AND KIPT.
MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH.
NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY
CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE
REGION.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR
CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS
INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE.
ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY
EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN
AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR
WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE
REGION.
EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND
BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT.
HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING
AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW
SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING.
MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY
MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR
BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON
AS HIGH PRESSURE MOVES OVER THE STATE.
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY
NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER
LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR
TRACK WED-THUR.
OUTLOOK...
MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS.
TUE...VFR. RESTRICTIONS PSBL TUE NGT.
WED/THU...RESTRICTIONS LKLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
227 PM EST SAT FEB 25 2012
.SYNOPSIS...
A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN
THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN
MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT
WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE
NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL
TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE
BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID-
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO
COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING
OFF LATER TODAY AND THIS EVE.
LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST
MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND
MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE
HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING
DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO
LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME
WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR
THE ORGANIZATION WILL BECOME.
OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER
NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO
SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A
LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS
HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER
INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND
FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET.
LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO
CLIMO NORMS.
HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY
GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE
AND IF ANY RECUR THEY WILL BE ISOLATED.
&&
.SHORT TERM /SUNDAY/...
SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE
ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS
THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON
EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG
BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES
HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST
COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH.
VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN
FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE
NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES.
THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND
PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE
REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN
PLAINS AND ACROSS THE UPPER GLAKES REGION.
THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND
OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE
NORTH OF LAKE ONTARIO.
TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN
AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE
NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER
SUSQ VALLEY.
ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR
WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE
UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER
STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH
INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC
MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE
GFS OR GEFS SOLUTIONS.
EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY
ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA
COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN
CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM
AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER
GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH
ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET
BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC
SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME
ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND
EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW
INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV
AND KIPT.
MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH.
NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY
CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE
REGION.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR
CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS
INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE.
ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY
EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN
AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR
WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE
REGION.
EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND
BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT.
HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING
AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW
SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING.
MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY
MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR
BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON
AS HIGH PRESSURE MOVES OVER THE STATE.
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY
NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER
LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR
TRACK WED-THUR.
OUTLOOK...
MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS.
TUE...VFR. RESTRICTIONS PSBL TUE NGT.
WED/THU...RESTRICTIONS LKLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1136 AM EST SAT FEB 25 2012
.SYNOPSIS...
A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN
THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN
MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT
WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE
NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL
TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE
BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID-
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST
MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND
MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE
HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING
DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO
LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME
WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR
THE ORGANIZATION WILL BECOME.
OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER
NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO
SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A
LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS
HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER
INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND
FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET.
LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO
CLIMO NORMS.
HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY
GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE
AND IF ANY RECUR THEY WILL BE ISOLATED.
&&
.SHORT TERM /SUNDAY/...
SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE
ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS
THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON
EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG
BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES
HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST
COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH.
VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN
FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE
NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES.
THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND
PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE
REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN
PLAINS AND ACROSS THE UPPER GLAKES REGION.
THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND
OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE
NORTH OF LAKE ONTARIO.
TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN
AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE
NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER
SUSQ VALLEY.
ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR
WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE
UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER
STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH
INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC
MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE
GFS OR GEFS SOLUTIONS.
EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY
ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA
COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN
CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM
AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER
GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH
ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET
BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC
SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME
ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND
EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW
INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV
AND KIPT.
MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH.
NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY
CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE
REGION.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR
CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS
INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE.
ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY
EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN
AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR
WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE
REGION.
EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND
BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT.
HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING
AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW
SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING.
MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY
MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR
BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON
AS HIGH PRESSURE MOVES OVER THE STATE.
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY
NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER
LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR
TRACK WED-THUR.
OUTLOOK...
MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS.
TUE...VFR. RESTRICTIONS PSBL TUE NGT.
WED...RESTRICTIONS LKLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ004-005.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ024-033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1022 AM MST SAT FEB 25 2012
.UPDATE...
ADDED WIND ADVISORY FOR TODAY. RUC BUFKIT SOUNDINGS WITH SUPPORT
FROM NAM FORECAST SOUNDINGS INDICATE POTENTIAL FOR STRONG DOWNWARD
MOMENTUM TRANSFER OVER MUCH OF THE AREA. FAIRLY STRONG WINDS JUST
ABOVE THE SURFACE AND ALREADY OBSERVED STRONG AND GUSTY SURFACE
WINDS SUGGEST THE MOMENTUM TRANSFER IS ALREADY UNDERWAY. OBSERVED
STRONG SFC WINDS AND EXPECTED FURTHER INCREASE IN WINDS IN
NORTHEAST WY ALSO PROMPTED ISSUANCE OF AN AIR QUALITY ALERT FOR THE
POWDER RIVER BASIN.
WIND SPEEDS SHOULD DECREASE THIS EVENING EVEN AS STRONG PRESSURE
RISES APPROACH FROM THE WEST AND WINDS GO MOSTLY WESTERLY OVER OUR
CWA. SUNDAY...WE EXPECT STRONG WINDS AGAIN...BUT FROM THE
NORTHWEST BEHIND THE SURFACE LOW.
BUMPED WINDS UP FOR TODAY AND MADE MINOR CHANGES IN SKY...POP AND
WEATHER GRIDS TO FIT PRESENT TRENDS. OTHERWISE FORECAST IS ON
TRACK.
&&
.AVIATION...18Z TAFS
STRONG WINDS WILL DOMINATE THE FORECAST TODAY INTO SUNDAY. GUSTY
SOUTHERLY WINDS CONTINUE ACROSS CENTRAL SOUTH DAKOTA TODAY.
MEANWHILE...SOUTHWEST WINDS OVER NORTHEAST WYOMING WILL SPREAD
ACROSS SOUTHWEST SOUTH DAKOTA THIS AFTERNOON AND EVENING AS A TROF
OF LOW PRESSURE MOVES THROUGH. AN AREA OF LOW PRESSURE WILL TRACK
ALONG THE ND/SD BORDER OVERNIGHT...WITH STRONG NORTHWEST WINDS IN
THE WAKE OF A COLD FRONT. THE STRONG NORTHWEST WINDS WILL CONTINUE
THROUGH SUNDAY MORNING ACROSS THE PLAINS NORTH AND EAST OF THE BLACK
HILLS. A FEW -SHRA/-SHSN POSSIBLE LATE THIS AFTERNOON ACROSS
NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA...WITH SCATTERED SNOW
SHOWERS OVERNIGHT. IFR VSBY EXPECTED WITH SNOW SHOWERS...ESPECIALLY
ACROSS THE NORTHERN BLACK HILLS AND BEAR LODGE MOUNTAINS.
&&
.PREV DISCUSSION... /ISSUED 316 AM MST SAT FEB 25 2012/
DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE
OVER THE CENTRAL DAKOTAS...WITH LOW PRESSURE OVER SOUTHERN AB. A
NEARLY STATIONARY FRONTAL BOUNDARY IS IN PLACE OVER THE AREA. UPPER
LEVEL ANALYSIS HAS SHORTWAVE RIDGE OVER THE NORTHERN ROCKIES
MOVING QUICKLY EAST INTO THE HIGH PLAINS...WITH A SHORTWAVE TROF
OVER THE PACIFIC NW. SKIES ARE MOSTLY CLEAR ACROSS MUCH OF THE
AREA...WITH SOME PATCHY LOW CLOUDS ACROSS WESTERN SD. TEMPS ARE IN
THE TEENS AND LOWER 20S ACROSS THE AREA...WITH WINDS INCREASING IN
THE GCC AREA.
A MILD DAY IS ON TAP FOR THE AREA AS RIDGE QUICKLY CROSSES THE
REGION. THE SHORTWAVE TROF AND A COLD FRONT WILL APPROACH WESTERN
AREAS LATE TODAY AND QUICKLY CROSS THE AREA TONIGHT. MAIN CHANCES
FOR PCPN STILL LOOK TO BE ACROSS NORTHERN PORTIONS OF THE
CWA...ESPECIALLY THE WESTERN AND NORTHERN BLACK HILLS AREA...THIS
EVENING. STRONG WEST-NORTHWEST WINDS WILL DEVELOP ACROSS THE
PLAINS LATER TONIGHT AND ESPECIALLY ON SUNDAY. AFTER THIS...MAIN
CONCERN WILL BE WITH PROJECTED WINTER STORM THAT WILL IMPACT THE
REGION MONDAY NIGHT AND TUESDAY.
FOR TODAY...CLOUDS WILL GENERALLY INCREASE ACROSS THE AREA...WITH
A GOOD DEAL OF SUN STILL EXPECTED IN THE MORNING...ESPECIALLY
ACROSS SOUTHERN AND EASTERN PORTIONS OF THE CWA. WARMER AIR WILL
PUSH INTO THE AREA AS FRONTAL BOUNDARY MOVES OFF TO THE EAST.
TEMPS WILL MOSTLY BE IN THE 40S...WITH SOME LOWER 50S ACROSS
SOUTHWESTERN SD. SOUTH-SOUTHEAST WINDS WILL BE GUSTY ACROSS
PORTIONS OF THE AREA...MAINLY SOUTHERN AND EASTERN PORTIONS OF THE
CWA. THE WINDS COULD APPROACH ADVISORY CRITERIA FOR A TIME DURING
THE MIDDAY AND EARLY AFTERNOON HOURS TOWARD CENTRAL SD. CHANCES
FOR SHOWERS SHOULD HOLD OFF UNTIL LATE AFTERNOON ACROSS
NORTHEASTERN WY INTO FAR NORTHWESTERN SD AS COLD FRONT APPROACHES.
THE BEST CHANCES FOR PCPN TONIGHT...MAINLY SNOW SHOWERS...WILL BE
ACROSS FAR NORTHEASTERN WY...THE BLACK HILLS...AND NORTHWESTERN
SD. A LIGHT ACCUMULATION OF SNOW LOOKS LIKE A GOOD BET FROM
PORTIONS OF FAR NORTHEASTERN WY INTO THE NORTHERN BLACK HILLS...UP
TO A COUPLE OF INCHES OR SO. FAR NORTHWESTERN SD COULD ALSO SEE A
DUSTING OF SNOW TONIGHT. COLD FRONT WILL PASS QUICKLY ACROSS THE
REST OF THE CWA THIS EVENING. PRESSURE GRADIENT WILL TIGHTEN
BEHIND THE FRONT OVERNIGHT AND EARLY SUNDAY.
SUNDAY WILL BE VERY WINDY AS STRONG LOW LEVEL JET AND COLD
ADVECTION COMBINE TO PRODUCE GUSTY WINDS ACROSS MUCH OF THE AREA.
THE STRONGEST WINDS WILL BE ACROSS THE USUAL WINDY AREAS OF THE
NORTHWEST AND WEST CENTRAL SD PLAINS...WHERE GUSTS OVER 50 MPH CAN
BE EXPECTED. CHANCES FOR SNOW SHOWERS WILL BE RATHER LOW...MAINLY
CONFINED TO THE NORTHERN BLACK HILLS AND FAR NORTHWESTERN SD.
WINDS AND PCPN CHANCES WILL DIMINISH LATE IN THE DAY. HIGHS WILL
BE MOSTLY IN THE 30S.
MONDAY WILL SEE AN INCREASE IN CLOUDS AS A MUCH STRONGER TROF
MOVES ACROSS THE WESTERN CONUS. THERE IS A CHANCE FOR SNOW LATE IN
THE DAY AS SOUTHWEST FLOW AHEAD OF DEVELOPING SYSTEM BRINGS SOME
UPPER LEVEL ENERGY ACROSS THE AREA. HOWEVER...IT LOOKS LIKE MAIN
CHANCES FOR SNOW WILL HOLD OFF UNTIL MONDAY NIGHT. DEVELOPING
UPPER LOW WILL MOVE QUICKLY ACROSS THE ROCKIES MONDAY NIGHT...
LIKELY REACHING THE CENTRAL HIGH PLAINS BY TUESDAY MORNING. UPPER
LEVEL WAVE AHEAD OF THE LOW WILL MOVE NORTHEAST ACROSS THE REGION
MONDAY NIGHT AND BRING SNOW TO MUCH IF NOT ALL OF THE AREA. MOST
OF THE MEDIUM RANGE MODELS ARE IN RELATIVELY GOOD AGREEMENT ON THE
TRACK OF THE SYSTEM...BUT 00Z MODEL RUNS CONTINUE TO SHOW TIMING
ISSUES. ECMWF IS MUCH SLOWER THAN GFS AND CANADIAN...HOLDING OFF
GENERAL SNOWFALL UNTIL LATE TONIGHT OR TUESDAY MORNING. EVEN WITH
THESE ISSUES...THEY ALL ARE IN AGREEMENT ON A GOOD PORTION OF THE
AREA SEEING SOME SIGNIFICANT SNOWFALL...WITH THE HIGHER AMOUNTS
GENERALLY THE FURTHER EAST YOU GO. IF THE TRENDS HOLD...A WINTER
STORM WATCH WILL LIKELY BE ISSUED FOR MOST OR ALL OF THE CWA
LATER TODAY OR EARLY SUNDAY FOR THIS SYSTEM.
EXTENDED...MODELS REMAIN IN GOOD AGREEMENT WITH THE TRACK OF THE
LOW PRESSURE SYSTEM FROM SOUTHWESTERN NEBRASKA ON TUESDAY
MORNING...TO NORTHEASTERN NEBRASKA ON TUESDAY EVENING. HOWEVER
TIMING DIFFERENCES REMAIN...WITH THE 00Z ECMWF SOLUTION NOW ABOUT 6
HOURS BEHIND THE 00Z GFS TIMING. EITHER WAY...MOST MODELS AND
MEMBERS CONTINUE TO SHOW THE PROBABILITY OF SW/NE ORIENTED BAND OF
SIGNIFICANT SNOWFALL DEVELOPING SOMEWHERE ACROSS SOUTH DAKOTA ON
TUESDAY INTO TUESDAY NIGHT...ALTHOUGH IT/S STILL TOO EARLY TO
DETERMINE EXACTLY WHERE THAT BAND MAY DEVELOP AND WHAT THE PRECISE
SNOWFALL AMOUNTS WILL BE. WIND COULD ALSO BE A BIG
FACTOR...ESPECIALLY ACROSS CENTRAL SOUTH DAKOTA...DEPENDING ON
STRENGTH OF SURFACE LOW. THE LOW PRESSURE SYSTEM WILL DEPART THE
AREA WEDNESDAY...WITH FLAT UPPER RIDGE ACROSS THE NORTHERN HIGH
PLAINS. THE NEXT...MUCH WEAKER...UPPER TROF WILL AFFECT THE AREA ON
THURSDAY. TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR BENNETT-
BUTTE-CUSTER CO PLAINS-HAAKON-HARDING-JACKSON-MELLETTE-
NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS-
SHANNON-SOUTHERN MEADE CO PLAINS-TODD-TRIPP-ZIEBACH.
WIND ADVISORY FROM 8 AM TO 5 PM MST SUNDAY FOR BUTTE-HAAKON-
HARDING-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS-
PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SOUTHERN MEADE CO
PLAINS-STURGIS/PIEDMONT FOOT HILLS-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...15 AND BARBER
LONG TERM....07
AVIATION...07
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
940 PM MST FRI FEB 24 2012
.AVIATION...06Z TAFS
VFR CONDITIONS ARE EXPECTED TONIGHT AS SOME SCT MID/HIGH CLOUDS
PASS OVERHEAD. CLOUDS WILL INCREASE SATURDAY FROM WEST TO EAST
WITH AREAS CIGS LOWERING TO 4-6KFT AND THE WEST...SOME SHOWERS
MAY DEVELOP IN THE NORTH AND WEST. GUSTY SOUTHWEST WINDS WILL
DEVELOP OVER NORTHEASTERN WY AND THE BLACK HILLS LATER
TONIGHT...LASTING INTO SATURDAY AFTERNOON. GUSTY SOUTHERLY WINDS
WILL DEVELOP ON THE SD PLAINS BY MIDDAY SATURDAY. WINDS WILL
SWITCH TO THE NORTHWEST BEHIND A COLD FRONT SATURDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 852 PM MST FRI FEB 24 2012/
DISCUSSION...03Z SURFACE ANALYSIS HAD WEAK RIDGE OVER THE DAKOTA
WITH SURFACE TROUGH FORMING FROM MT INTO CENTRAL WY...COINCIDENT
WITH INCREASE SURFACE PRESSURE FALLS. UPPER RIDGE OVER THE ROCKIES
WILL MOVE OVER THE CWA INTO SATURDAY WITH WELL-DEFINED WARM AIR
ADVECTION. SOUTHERLY GRADIENT INCREASES WHICH WILL BRING GUSTY
SOUTHWEST WINDS LATER TONIGHT OVER NORTHEASTERN WY/BLACK HILLS AND
THEN GUSTY SOUTHERLY WINDS ON THE SD PLAINS SATURDAY. WILL UPDATE
FORECAST TO HAVE STRONG WINDS ON THE PLAINS FOR SATURDAY. WILL
ALSO TWEAK TEMPERATURES FOR LATEST TRENDS.
PREV DISCUSSION... /ISSUED 345 PM MST FRI FEB 24 2012/
DISCUSSION...THE STRONG LOW PRESSURE SYSTEM CROSSING THE NORTHERN
PLAINS ON SUNDAY WILL PRODUCE WEST TO NORTHWEST WINDS OF 25 TO 40
MPH WITH WIND GUSTS UP TO 55 MPH. HAVE ISSUED A WIND ADVISORY FOR
THE NORTHWEST AND WEST CENTRAL SOUTH DAKOTA PLAINS.
PREV DISCUSSION... /ISSUED 240 PM MST FRI FEB 24 2012/
DISCUSSION...
LONG WAVE RIDGE NEAR 130W AND TROF NEAR 95W WITH CONTINUED FLOW OF
COOL...UNSTABLE AIR OVER THE AREA TODAY. SHORT WAVE RIDGE
APPROACHING FROM THE WEST FORECAST TO BE OVER THE AREA FRIDAY
NIGHT AND EARLY SATURDAY. NEXT UPSTREAM TROF WILL CROSS THE
PACIFIC NW COAST LATE TONIGHT AND MOVE QUICKLY EAST WARD.
STEEP LAPSE RATES AND A BIT OF MID TROPOSPHERIC Q VECTOR
CONVERGENCE HAVE SUPPORTED THE DEVELOPMENT OF SNOW SHOWERS AGAIN
TODAY. MID AFTERNOON RADAR AND SATELLITE OBS INDICATE THESE ARE
FINALLY WINDING DOWN AS SUBSIDENCE WARMING FORECAST BY BOTH THE
NAM AND RUC MODELS SEEMS TO BE HAPPENING. REMNANT CLOUDS AND A
LITTLE PRECIP WILL PERSIST INTO THE EVENING HOURS OVER UPSLOPE
AREAS OF THE BLACK HILLS. A FEW SHOWERS ARE LIKELY TO RETURN TO NW
WY AND THE NW PORTIONS OF SD WITH APPROACH OF NEXT SHORT WAVE TROF.
NAM AND MESO MODELS INDICATE POTENTIAL FOR FAIRLY STRONG DOWNSLOPE
WINDS OVER THE NE SLOPES OF THE BLACK HILLS SATURDAY MORNING INTO
EARLY AFTERNOON. MODELS INDICATE ABOUT A 6MB PRESSURE DIFFERENCE
ACROSS THE HILLS AT 18Z AND THE NAM FORECAST SOUNDINGS SHOW 50KT
WINDS AT ABOUT 2000FT AGL OVER THE NORTHERN BLACK HILLS.
SATURDAY NIGHT...TRANSIENT UPPER RIDGE SHIFTS QUICKLY EAST AS NEXT
STRONG UPPER SHORTWAVE CROSSES THE NORTHERN ROCKIES. BOTH 500MB AND
700MB CLOSED LOWS TRACK NORTH OF THE FORECAST AREA...WITH BEST
CHANCES OF SNOW ACROSS NORTHEAST WYOMING...THE BLACK HILLS...AND
NORTHWESTERN SOUTH DAKOTA AS COLD FRONT MOVES THROUGH. BEST CHANCES
OF ACCUMULATING SNOWS WILL BE ACROSS THE NORTHERN BLACK HILLS. LOW
TEMPERATURES WILL FALL INTO THE TEENS AND 20S.
SUNDAY...UPPER LOW SLIDES INTO MINNESOTA AS BOUNDARY LAYER FLOW
BECOMES MORE WEST TO NORTHWEST. PRECIP CHANCES DIMINISH QUICKLY ON
SUNDAY MORNING...BUT VERY WINDY CONDITIONS WILL BE FOUND BEHIND THE
EXITING LOW ACROSS THE AREA. WINDS IN EXCESS OF 25 TO 35 MPH WITH
HIGHER GUSTS WILL BE POSSIBLE. HIGH TEMPERATURES WILL BE IN THE 30S
TO LOWER 40S.
EXTENDED...POTENTIAL FOR A STRONG WINTER STORM TO AFFECT THE AREA
EARLY NEXT WEEK. GFS/GEFS/ECMWF IN VERY GOOD AGREEMENT
MONDAY/TUESDAY WITH UPPER TROF SWINGING THROUGH THE CENTRAL ROCKIES
AND INTO THE PLAINS. GFS/GEFS/ECMWF SFC-500MB LOW TRACKS
SIMILAR...ACROSS WESTERN NEBRASKA TO SOUTHEAST SOUTH
DAKOTA/NORTHWEST IOWA. EVEN THOUGH TRACK IS SIMILAR...THERE IS
SOME STRENGTH AND TIMING DIFFERENCES. ALL GEFS MEMBERS SHOW
MEASURABLE PRECIPITATION ACROSS NORTHEAST WYOMING AND WESTERN
SOUTH DAKOTA MONDAY NIGHT/TUESDAY. GIVEN HIGHER MODEL
CONFIDENCE...HAVE BOOSTED POPS FOR MONDAY NIGHT/TUESDAY. WIND
COULD ALSO BE A BIG FACTOR DEPENDING ON STRENGTH OF SURFACE LOW.
UPPER LOW DEPARTS THE AREA WEDNESDAY...WITH FLAT UPPER RIDGE
ACROSS THE NORTHERN HIGH PLAINS. NEXT UPPER TROF TO AFFECT THE
AREA THURSDAY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 8 AM TO 5 PM MST SUNDAY FOR BUTTE-HAAKON-
HARDING-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS-
PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SOUTHERN MEADE CO
PLAINS-STURGIS/PIEDMONT FOOT HILLS-ZIEBACH.
WY...NONE.
&&
$$
SHORT TERM...WFO UNR
LONG TERM....WFO UNR
AVIATION...HELGESON
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1221 PM CST SAT FEB 25 2012
.DISCUSSION...RAIN SHOWERS ARE ENDING ACROSS THE AREA THIS
AFTERNOON AS THE MID LEVEL LOW EXITS THE AREA. HAVE DECREASED POPS
OVER THE AREA FOR THIS AFTERNOON AS MOST OF THE SHOWER ACTIVITY
IS CURRENTLY OVER THE GULF...SOUTH PADRE ISLAND...AND EASTERN
CAMERON COUNTY. SURFACE OBSERVATIONS ALONG WITH LAPS AND RUC DATA
INDICATE THAT CURRENT TEMPERATURES ARE IN THE THE UPPER 40S AND
LOW 50S ACROSS THE AREA. ABUNDANT CLOUD COVER THIS AFTERNOON
SHOULD KEEP TEMPERATURES TO NEAR STEADY THROUGH THE REST OF TODAY
SO HAVE LOWERED MAX TEMPERATURES A FEW DEGREES. UPDATED PRODUCTS
WILL BE OUT SHORTLY.
&&
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS.
MVRF CEILINGS SHOULD IMPROVE IN THE NEXT HOUR OR SO AS LOW CLOUDS
AND LIGHT RAIN AT BRO MOVES OUT OF THE AREA. SKIES WILL BEGIN TO
CLEAR THIS EVENING BUT LOW LEVEL MOISTURE IS EXPECTED TO BRING A
RETURN TO LOWER CLOUD CEILINGS SUNDAY MORNING. CEILINGS SHOULD
REMAIN ABOVE MVFR CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST SAT FEB 25 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...AN OVERRUNNING SITUATION NOW WITH COOLER NORTH WINDS
UNDER SOUTHWEST FLOW ALOFT. THE TRAJECTORY OF A MID LEVEL LOW JUST
TO THE WEST KEEPS MORNING RAIN SHOWERS PRIMARILY OVER THE MID
VALLEY. OVC VFR CEILINGS EXPECTED WHILE LOW ALOFT LIFTS NORTHEAST.
RAIN SHOULD END THIS AFTERNOON WITH MODERATE NORTH WINDS BECOMING
LIGHT TO MODERATE NORTHEAST.
PREV DISCUSSION... /ISSUED 233 AM CST SAT FEB 25 2012/
SHORT TERM /TODAY THROUGH SUNDAY/...SATELLITE SHOWS A MID LEVEL
FEATURE LIFTING NORTHEAST OUT OF NORTHEAST MEXICO INTO THE RIO
GRANDE PLAINS...WITH DIVERGENCE OVER DEEP SOUTH TEXAS AND THE RIO
GRANDE VALLEY. LOW LEVEL COLD AIR ADVECTION IS STABILIZING THE
BOUNDARY LAYER...WHILE SOUTHWEST FLOW ALOFT IS BRINGING MOISTURE
ACROSS AND IS RESULTING IN THE ELEVATED RAINFALL OVERSPREADING THE
MID AND UPPER VALLEY EARLY THIS MORNING. THE BEST LIFT IS FORECAST
THROUGH ABOUT NOON WITH QPF AMOUNTS OF UP TO ONE HALF AN INCH FOR
THE LOWER VALLEY. THUNDER IS NOT IN THE FORECAST RIGHT NOW...BUT
SOME EMBEDDED STORMS MAY DEVELOP. OTHERWISE...OVERCAST SKIES WILL
CONTINUE WITH HIGH TEMPS TODAY IN THE UPPER 50S TO LOWER 60S. AS THE
MID LEVEL FEATURE MOVES NORTHEAST UP THE TEXAS COASTLINE LATER
TODAY...RAIN CHANCES OVER THE CWA WILL END WITH LOW TEMPS TONIGHT
AGAIN MAINLY IN THE 40S. WE SHOULD SEE PARTIAL CLEARING ON SUNDAY
WITH LIGHT ONSHORE WINDS AND WITH HIGH TEMPS IN THE UPPER 60S TO
AROUND 70. THE FORECAST HAS NOT CHANGED MUCH WITH AT LEAST AVERAGE
CONFIDENCE IN MODEL RELIABILITY.
LONG TERM.../SUNDAY NIGHT THROUGH SATURDAY.
SUNDAY NIGHT EASTERLY ONSHORE FLOW WILL BE IN PLACE GRADUALLY
INCREASING LOW LEVEL MOISTURE AND DEW POINTS. CONTINUING TO GO A
LITTLE BELOW GUIDANCE IN TERMS OF SURFACE DEW POINT HOWEVER GIVEN THE
EXTENSIVE AIR MASS MODIFICATION THAT OCCURRED WITH THE RECENT FRONTAL
PASSAGE. WINDS SLACKEN OVERNIGHT SUNDAY AND SOME AREAS OF FOG WILL
LIKELY RETURN BY MONDAY MORNING.
WINDS WILL SHIFT MORE SOUTHERLY TUESDAY AND WEDNESDAY AS UPPER
RIDGING BUILDS TO THE SOUTH AND A STORM SYSTEM MOVES OVER THE PLAINS
STATES. THIS SHOULD CONTINUE TO GRADUALLY INCREASE LOW LEVEL
MOISTURE AND HAVE CONTINUED A SLIGHT CHANCE FOR AFTERNOON SHOWERS.
IT LOOKS FOR NOW THAT LARGE SCALE SUBSIDENCE AND SOUTHWESTERLY WINDS
WILL WARM TEMPS IN THE MID LEVELS SUFFICIENTLY TO PREVENT MUCH IN
THE WAY OF SHOWER AND ESPECIALLY THUNDERSTORM ACTIVITY IN THE FORM
OF CAPPING...BUT MOISTURE IN PLACE AND OUR POSITION ON THE RIGHT
EXIT REGION OF THE BROAD JET OVER THE CENTRAL US SUGGESTS AT LEAST
SOME POSSIBILITY OF PRECIS.
00Z ECMWF/GFS IN GOOD AGREEMENT WITH DRAGGING A FRONTAL BOUNDARY
RIGHT TO ABOUT OR NORTHERN CWA BORDER WEDNESDAY AFTERNOON BEFORE
SOUTH WINDS INCREASE AHEAD OF THE NEXT STORM SYSTEM. WITH THE
FRONTAL BOUNDARY AND LOW LEVEL MOISTURE IN PLACE BUMPED UP POPS FOR
THURSDAY AFTERNOON JUST A BIT AS THE TREND OVER THE LAST 24 HOURS OR
SO IN GUIDANCE HAS BEEN FOR THAT PERIOD TO HAVE THE BEST CHANCE FOR
SHOWERS AND POSSIBLY A RUMBLE OF THUNDER.
MODEL AGREEMENT GETS MORE MUDDIED FROM THAT POINT. STRONG SOUTHERLY
WINDS SHOULD WARM US UP QUITE A BIT ON FRIDAY. THE ECMWF IS THEN
FASTER AND STRONGER WITH A FRONTAL PASSAGE FRIDAY AFTERNOON AND
EVENING...WHEREAS THE GFS IS MORE IN THE SUNDAY MORNING CATEGORY FOR
NOW. GFS IS MORE ZONAL WITH THE FLOW WHEREAS ECMWF IS MORE
AMPLIFIED...WILL HOLD WITH THE GOING TIMING FOR NOW WHICH IS MORE IN
LINE WITH THE GFS. KEPT POPS FAIRLY LOW AT THE END OF THE PERIOD
GIVEN TIMING CONCERNS AND LACK OF LARGE SCALE ASCENT AND WARM
TEMPERATURES IN THE MID LEVELS.
MARINE...
TODAY THROUGH SUNDAY...BUOY020 REPORTS NORTH NORTHEAST WINDS AT 20
KTS WITH GUSTS TO 23 KNOTS AND WAVE HEIGHTS OF 9.5 FEET EARLY THIS
MORNING. WINDS WILL SLOWLY DIMINISH TODAY AS THE PRESSURE GRADIENT
RELAXES. SHOWERS AND EMBEDDED THUNDERSTORMS WILL CONTINUE THIS
MORNING UNTIL A MID LEVEL DISTURBANCE MOVES OVER THE AREA AND EXITS
TO THE NORTHEAST LATER TODAY. WAVE HEIGHTS WILL REMAIN HIGH TODAY
AND TONIGHT WITH THE SMALL CRAFT ADVISORY NOW EXTENDED THROUGH THIS
EVENING. WINDS WILL DECREASE TO LIGHT EAST NORTHEAST TONIGHT AND
SUNDAY.
SUNDAY NIGHT THROUGH THURSDAY...MODERATE EAST WINDS WILL CONTINUE
SUNDAY NIGHT THROUGH MONDAY. STRONGER EAST WINDS IN THE NORTH
CENTRAL GULF OF MEXICO MAY LEAD TO PERIODS OF ROUGH SEAS IN THE
OFFSHORE WATERS THROUGH LATE MONDAY. MODERATE...GENERALLY SOUTH
WINDS AND SEAS ARE EXPECTED TUESDAY THROUGH THURSDAY WITH WIND
BECOMING GUSTY IN THE AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 57 51 68 64 / 70 10 10 10
BROWNSVILLE 58 49 69 62 / 70 10 10 10
HARLINGEN 57 48 70 63 / 70 10 10 10
MCALLEN 58 49 70 64 / 60 10 10 10
RIO GRANDE CITY 59 46 70 62 / 30 10 10 10
SOUTH PADRE ISLAND 59 52 68 64 / 70 10 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ150-155-
170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
63
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1039 PM CST FRI FEB 24 2012
.UPDATE...
A BREAK IN THE SNOW SHOWERS...WITH ISOLATED SNOW SHOWERS DROPPING
SE FROM SE MN/W CNTRL WI TOWARD THE NW CWA IN THE DIFFERENTIAL CVA AHEAD
OF STRONG VORT/26 UNITS ON RUC ANALYSIS/NEAR MSP. WILL NOT SEE
MUCH IN THE WAY OF ACCUMULATIONS...BUT WILL SEE BRIEF VISBILITY
REDUCTIONS IN THE HEAVIER SNOW SHOWERS.
&&
.AVIATION/06Z TAFS/...
WILL REMOVE CATEGORICAL MENTION OF P6SM -SHSN/FLURRIES FROM TAFS
AND TRY AND TIME THE BRIEF PERIOD OF ISOLATED LIGHT SNOW SHOWERS
THAT WILL MOVE ACROSS THE TAF SITES BETWEEN 06Z AND 11Z. NO
ACCUMULATIONS...BUT COULD SEE A BRIEF 4-5SM VSBY WITH A HEAVIER
SNOW SHOWER. STILL TAPPING 25 TO 29 KNOT WINDS ALOFT SO WINDS WILL
STAY UP THOUGH GUSTS A BIT MORE INFREQUENT THAN DURING THE DAY.
MORE FREQUENT WIND GUSTS RETURN WITH MIXING IN THE MORNING SATURDAY...WITH
WINDS SLOWLY DIMINISHING DURING THE AFTERNOON. ONLY SCT MVFR CIGS
UPSTREAM WITH MOST CIGS IN THE 3500 TO 4500 FT RANGE. WILL KEEP
CIGS JUST AT VFR...WITH A SCT 2500 FT TO ACCOUNT FOR POTENTIAL OF A
BRIEF MVFR CIG WITH A HEAVIER SNOW SHOWER IF THEY PASS OVER A TAF
SITE. WILL SCATTER OUT CIGS LATE AFTERNOON/EARLY EVENING AS
CYCLONIC FLOW SHIFTS EAST AND RIDGING BUILDS IN.
&&
.MARINE...
NO CHANGE TO CURRENT SMALL CRAFT ADVISORY. STILL TAPPING 25 TO 29 KNOT
WINDS ALOFT SO WINDS WILL STAY UP...THOUGH GUSTS A BIT MORE
INFREQUENT AT LAKE SHORE OB SITES THAN DURING THE DAY. DEEPER
MIXNG OVER RELATIVELY WARMER LAKE WATERS WILL LEAD TO MORE
FREQUENT WIND GUSTS PER THE CHICAGO CRIB SITE. WINDS SLOWLY EASE
THROUGH THE EARLY MORNING...WITH WINDS AT OR BELOW 20 KTS BY 16Z.
&&
.PREV DISCUSSION... /ISSUED 310 PM CST FRI FEB 24 2012/
VERY SHORT TERM...TONIGHT AND SATURDAY.
CYCLONIC FLOW CONTINUES ALOFT WITH A SHORTWAVE DROPPING DOWN FROM MN
THIS EVENING. WIDESPREAD LIGHT SNOW SHOWERS ASSOCIATED WITH THE
LEADING EDGE OF THIS SHORTWAVE ARE APPARENT ON REGIONAL RADAR...CAN
BE TRACED BACK TO MINNEAPOLIS AREA. THESE SNOW SHOWERS MAY LIGHTEN
UP A LITTLE WITH THE LOSS OF DAYTIME HEATING AS THE LOW LEVEL LAPSE
RATES DECREASE A BIT...BUT SHOULD CONTINUE THROUGH MUCH OF THE
EVENING...ESPECIALLY IN EASTERN FORECAST AREA. THEN THE SHOWERS
SHOULD TAPER OFF FROM WEST TO EAST AFTER MIDNIGHT...WITH A FEW
FLURRIES LINGERING HERE AND THERE THROUGH MORNING.
THERE IS ANOTHER AREA OF RADAR RETURNS OVER EASTERN SD ASSOCIATED
WITH A SFC TROUGH AND UPPER SHORTWAVE THAT SHOULD STAY SOUTH OF WI
TONIGHT.
COLD AIR ADVECTION WILL ALLOW FOR TEMPS TO DROP INTO THE UPPER TEENS
TO AROUND 20 TONIGHT...WHICH IS WARMER THAN WHAT 850MB AND 925MB
TEMPS WOULD SUGGEST DUE TO EXPECTED CLOUD COVER.
WINDS SHOULD REMAIN FAIRLY BRISK OVERNIGHT AS A TIGHT PRESSURE
GRADIENT LINGERS OVER THE REGION.
DESPITE HIGH PRESSURE WORKING ITS WAY INTO SOUTHERN WI...CLOUDS WILL
BE SLOW TO CLEAR DURING THE DAY SINCE THE UPPER LEVEL TROUGH WILL BE
SLOW TO MOVE EASTWARD. WITH THE CYCLONIC FLOW HANGING
AROUND...WIDESPREAD SCATTERED TO BROKEN CUMULUS CLOUDS ARE EXPECTED
THROUGH AT LEAST NOON IN SOUTH CENTRAL WI AND THROUGH AT LEAST 3 PM
IN SOUTHEAST WI. THERE WILL BE SOME BREAKS IN THE CLOUDS AS THE DAY
GOES ON.
MODEL SNDGS DRY OUT EARLY SAT MORNING AT MADISON AND BY 12Z SAT AT
MILWAUKEE. FINAL VORT MAX CLEARING EASTERN WI 12-18Z SAT...WITH NO
REMAINING Q-VECTOR CONV OR UPPER LEVEL DIVERGENCE TO SUPPORT
LINGERNING SNOW SHOWERS. NONETHELESS...A FEW FLURRIES DROPPING OUT
OF THE MORNING CLOUDS ARE NOT OUT OF THE QUESTION.
AS FOR TEMPERATURES...AFTER A COLD START SAT MORNING...TEMPS WILL
GRADUALLY WARM THROUGH THE DAY WITH WEAK WARM AIR ADVECTION ALOFT.
ANY SUNSHINE IN THE AFTERNOON WILL HELP INCREASE THE TEMPS TO ABOVE
FREEZING...BUT AT THIS TIME...EXPECTING HIGHS AROUND 29 TO 31
DEGREES.
SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.
SHORT WAVE RIDGING AHEAD OF STRENGTHENING PLAINS LOW PRESSURE WILL
RESULT IN QUIET WX ACROSS SRN WI SAT NGT. FRESH SNOW COVER OVER
MOST OF THE CWA SHOULD ALLOW TEMPS TO FALL RAPIDLY LATE SAT AFTN AND
EVE...HOWEVER INCREASING MID/HIGH CLOUDS ASSOCIATED WITH UPSTREAM
WARM AIR ADVECTION WL TEMPER OVERNIGHT TEMPS DURING THE LATE EVENING
AND LATE NIGHT.
SHORT TERM GUIDANCE SHOWING GOOD RUN TO RUN CONSISTENCY AS WELL AS
THE ENSEMBLES IN CARRYING LOW PRESSURE ACROSS THE NORTHERN PLAINS
AND THROUGH MN INTO FAR NRN WI BY 00Z/MON...SO CONFIDENCE INCREASING
ON THIS SCENARIO. EXPECT PROGRESSIVE SCENARIO WITH THIS NEXT EVENT
AS UPSTREAM KICKER BEGINS DIGGING INTO PACIFIC NORTHWEST LATE IN THE
WEEKEND. BEST AVAILABLE MOISTURE AND FORCING LINES UP TO THE NORTH
OVER NRN WI ON SUNDAY. HOWEVER...STRONG PUSH OF LOW TO MID LEVEL
WARM AIR ADVECTION ON SUNDAY WITH MID-LEVEL LAPSE RATES OF 6-7
DEGREES AND SOME MID LEVEL MOISTURE. HAVE TO CONSIDER SMALL CHANCE
FOR LIGHT PRECIPITATION WITH INITIAL SURGE OF WARM AIR ADVECTION AS
WELL AS SFC OCCLUSION MOVING THRU IN THE AFTN/EVE. LAYER Q-VECTOR
CONVERGENCE EXCEEDING 10 UNITS ALSO MOVES THROUGH DURING THE DAY.
HENCE WL KEEP LOW POPS GOING ON SUNDAY. STRONGEST LOW LEVEL WINDS
EXPECTED IN THE MORNING AND EARLY AFTN DURING GREATEST CLOUD COVER
WHICH WOULD RETARD MIXING. NEVER THE LESS...WITH EXPCD THIN SPOTS
IN CLOUD COVER...COULD BE A FEW WIND GUSTS APPROACHING WIND ADVY
CRITERIA IN THE LATE MRNG AND EARLY AFTN BEFORE THE STRONGEST WINDS
SHIFT EAST IN THE AFTN. WINDS AND LOWER DEWPTS SHOULD PREVENT
THICKER ADVECTION FOG FROM FORMING OVER SNOWFIELD. AS THE WINDS
BACK TO THE WEST BEHIND THE SFC OCCLUSION...DRIER AIR WL POUR BACK
INTO SRN WI SUN EVE. LESS WINDY CONDITIONS WL RETURN ON MONDAY AS
WEAK HIGH PRESSURE MOVES ACROSS THE WESTERN GTLAKES.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
PRIMARY FOCUS OF THIS PERIOD ON STRONG LOW PRESSURE EXPECTED TO
TRACK ACROSS THE CENTRAL PLAINS INTO SOUTHERN MINNESOTA AND NORTHERN
WISCONSIN TUESDAY AND WEDNESDAY. LONG TERM GUIDANCE IN REASONABLE
AGREEMENT ON THIS TRACK...AND LAST SEVERAL RUNS OF THE HI RES ECMWF
HAVE BEEN TRENDING NORTH...MORE IN LINE WITH GFS AND GEM-NHEM.
STRONG SOUTH WINDS AHEAD OF THIS SYSTEM WILL QUICKLY PULL DEEPER
MOISTURE NORTHWARD INTO SOUTHERN WISCONSIN. GFS PWAT VALUES
INCREASE TO AROUND 1.0. INITIAL WARM AIR ADVECTION SURGE ON TUESDAY
MAY BRING A MIXTURE OF RAIN...SLEET AND SNOW TO SOUTHERN WI BEFORE
WARMER AIR CHANGES MIXTURE OVER TO ALL RAIN. IF LOW TAKES PLANNED
TRACK INTO NORTHERN WI TUE NGT AND EARLY WED...THEN SOUTHEAST SFC
WINDS WOULD SHIFT TO THE WEST AFTER SFC OCCLUSION MOVES THROUGH TUE
NIGHT. WL NEED TO WATCH FOR BURST OF HEAVIER RAINFALL AHEAD OF
OCCLUSION TUE EVENING ON TOP OF FRESH SNOW COVER ENHANCING FLOODING
POTENTIAL.
AREAS OF LIGHT SNOW OR SNOW SHOWERS MAY SPREAD ACROSS SOUTHERN WI ON
WEDNESDAY AS OCCLUDING LOW PRESSURE PASSES ACROSS NRN WI. EXTENDED
GUIDANCE HINTING AT ANOTHER CLIPPER-TYPE SYSTEM BRINGING -SN BACK TO
SOUTHERN WI SOMETIME THU NGT OR FRI. GFS 5 DAY 500H MEANS SHOW
FAST W-NW FLOW CONTINUING OVER THE UPPER MIDWEST INTO THE FIRST DAYS
OF MARCH...RESULTING IN CONTINUED UNSETTLED CONDITIONS.
AVIATION /00Z TAFS/...
SCATTERED LIGHT SNOW SHOWERS ARE EXPECTED TO CONTINUE INTO THIS
EVENING AND GRADUALLY DIMINISH FROM WEST TO EAST FROM LATE EVENING
THROUGH JUST AFTER MIDNIGHT...POSSIBLY LINGERING THROUGH EARLY SAT
MORNING NEAR THE LAKESHORE. VISIBILITIES MAY DROP TO THE 4 TO 5 MI
RANGE AT TIMES WITHIN THESE SNOW SHOWERS...BUT GENERALLY SHOULD STAY
ABOVE 6 MI. TEMPS WILL COOL THROUGH THE NIGHT...ALLOWING LIGHT SNOW
SHOWERS TO POSSIBLY ACCUMULATE...WITH TOTAL ADDITIONAL SNOW
ACCUMULATIONS AROUND 0.1 INCH.
CEILINGS WILL BE VARIABLE LATE THIS AFTERNOON AND EARLY
EVENING...BUT SHOULD SETTLE TO AROUND 2500 TO 3500 FT AGL BY LATE
EVENING AND STAY THAT WAY THROUGH MID SAT MORNING. THERE IS PLENTY
OF UNCERTAINTY IN CEILING HEIGHTS. CLOUDS WILL BECOME BROKEN BY LATE
MORNING NEAR MSN AND MID AFTERNOON NEAR MKE...BUT WILL BE SLOW TO
CLEAR.
MARINE...
THE SMALL CRAFT ADVISORY WILL CONTINUE THROUGH TONIGHT INTO SATURDAY
MORNING DUE TO BRISK WESTERLY WINDS SLOW TO DIMINISH. HIGH PRESSURE
MOVING INTO SOUTHERN WI SAT MIDDAY WILL RELAX THE TIGHT PRESSURE
GRADIENT AND ALLOW WINDS AND WAVES TO DIMINISH. 3 TO 5 FOOT WAVES
WILL TAKE TIME TO DIMINISH OVERNIGHT...DESPITE THE OFFSHORE FLOW.
THE NEXT CHANCE FOR A SMALL CRAFT ADVISORY WILL BE SUNDAY INTO
SUNDAY NIGHT AS A STRONG LOW MOVES ACROSS NORTHWEST WISCONSIN. BRISK
SOUTHEAST WINDS WILL BUILD LARGE WAVES.
CONFIDENCE...
TONIGHT AND SATURDAY...HIGH.
SATURDAY NIGHT...HIGH.
SUNDAY THROUGH MONDAY...MEDIUM.
MONDAY NIGHT...HIGH.
TUESDAY THROUGH WEDNESDAY...MEDIUM.
THURSDAY AND FRIDAY...LOW TO MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST SATURDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/SATURDAY AND AVIATION/MARINE...MRC
SATURDAY NIGHT THROUGH FRIDAY...MBK
AREA FORECAST DISCUSSION
NWS MIAMI FL
245 AM EST MON FEB 27 2012
.DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH
AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS
MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS
A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS
NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH
MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE
REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW
AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM
BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER
MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS
DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE
FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST
STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT
FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN
A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING
THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA,
THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID
LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN
TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN
ACROSS FL THROUGH THE WEEK.
BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO
CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH
THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY
BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF
OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF
SHRA.
&&
.MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE
OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT
SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE
FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT
AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON.
&&
.FIRE WEATHER...NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 83 69 / 40 20 10 10
FORT LAUDERDALE 82 73 83 72 / 30 20 10 10
MIAMI 83 72 84 71 / 20 20 10 10
NAPLES 85 66 86 65 / 30 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
414 AM EST MON FEB 27 2012
.SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING
EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER
THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE
ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME
SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO
THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING
INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE
MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES
STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION.
THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING
WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW
DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY
12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES
THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO
THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED.
PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT
WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY
AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE
ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED
THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN
18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL
BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH
AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS
N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW
PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE
INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS
WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW
CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE
SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH
THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO
FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE.
TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7.
&&
.AVIATION... 06Z UPDATE...
LOWERING CIGS WILL BE THE RULE FOR TODAY AS CLOUD SHIELD HAS
ALREADY INFILTRATED ALL OF THE TAF SITES. EXPECTING MVFR TO
TRANSITION TO IFR FOR ALL SITES THROUGH 12Z WITH DEVELOPING -RA AS
WELL. MAIN QUESTION INVOLVES THE CHANCES OF SEEING LIFR FOR THE
ATL SITES OR EVEN VLIFR FOR CSG AND MCN. AT THIS TIME...BASED ON
DEVELOPING CLOUD DECK AND OBSERVATIONS TO THE SOUTH...WILL KEEP
ATL AT IFR BUT ANY DEVELOPING DZ SHORTLY AFTER DAYBREAK COULD TAKE
CONDITIONS EVEN LOWER. AS FOR WINDS...MOST MODELS ARE TAKING WINDS
TO NW LATER TODAY WITH THE EXCEPTIONS OF THE LOCAL WRF. BASED ON
ITS GOOD PERFORMANCE IN SUCH EVENTS...HAVE ELECTED TO KEEP WINDS E
TO NE FOR THIS TAF CYCLE BUT WILL LOOK AT CLOSER WITH 12Z
ISSUANCE.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON WINDS AND POTENTIAL FOR LIFR.
HIGH ON IFR DEVELOPMENT AND REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 44 71 53 / 30 0 20 30
ATLANTA 64 50 71 57 / 20 0 20 30
BLAIRSVILLE 63 40 66 50 / 10 0 20 50
CARTERSVILLE 64 42 71 53 / 10 0 20 40
COLUMBUS 66 50 75 58 / 30 5 10 20
GAINESVILLE 63 47 67 54 / 20 0 20 40
MACON 65 47 73 56 / 50 5 10 10
ROME 66 42 72 54 / 5 0 20 50
PEACHTREE CITY 64 42 71 55 / 20 0 20 30
VIDALIA 65 52 73 57 / 80 5 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CST MON FEB 27 2012
.DISCUSSION...
916 PM CST
SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT
DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST
AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING
AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE
AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN
NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT
ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE
FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY
ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL
PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN
GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER
THE FRONT.
A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS
DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR
WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE
MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST
CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A
GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT
CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY
OVERNIGHT AND SLOWLY SHIFT EAST.
THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE
DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT
ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES
BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE
BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING
MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE.
//PREV DISCUSSION...
320 PM CST
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN
WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE
UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS
PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED
FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH
STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN
CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH
MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT
COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER.
HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE
SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED
TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO
BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES
THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL
EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT
TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT
ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD
COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN
PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN
BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO
THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER
20S TO LOWER 30S ELSEWHERE.
FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH
WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH
PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS.
SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF
I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL
DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS
THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND
ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS
CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE
MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE
WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN
SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND
UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE
THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO
OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE
THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING
WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE
NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND
MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE
EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY
AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL
EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE
THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK
THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES
THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES
IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE
PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS
THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME
LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM
FOR WEDNESDAY AFTERNOON AND EVENING.
FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH
SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN
INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE.
THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO
SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM
WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC
LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO
CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER
CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR
THE NORTHERN PORTIONS OF THE CWA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* LIGHT SW-WSW WIND BECOMING W WITH SPORADIC GUSTS 15-20 KTS
DURING PREDAWN...THEN BECOMING GUSTY 20-25 KTS AFTER SUNRISE
BEFORE DIMINISHING STEADILY IN THE AFTERNOON.
* LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR
CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY
MONDAY.
TRS
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH
SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT
THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE
FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST
BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL
MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE.
AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER
PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST
WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW
MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING
AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING
WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON
HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE
TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS
LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET.
WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR
MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW
LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME
FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL
RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY
INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING...
THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST
A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY
CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE IN WIND TRENDS...THOUGH MODERATE CONFIDENCE IN
SPORADIC GUST SPEEDS PRIOR TO SUNRISE.
* HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD.
* LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN
STRATOCU DECK MID-MORNING/MIDDAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR
POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT.
WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE
OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE.
SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE.
RATZER
&&
.MARINE...
227 AM CST
AN ACTIVE WEATHER PATTERN IS EXPECTED OVER THE UPCOMING WEEK. THIS
MORNING...LOW PRESSURE OVER THE UPPER PENINSULA OF MICHIGAN WILL
CONTINUE TO PUSH EAST WITH A TRAILING COLD FRONT SWEEPING ACROSS
LAKE MICHIGAN. WINDS WITHIN THE FRONTAL TROUGH HAVE WEAKENED...BUT
ARE EXPECTED TO PICK UP AGAIN OUT OF THE WEST-NORTHWEST BEHIND THE
FRONT AS THE PRESSURE GRADIENT ONCE AGAIN TIGHTENS. WINDS TO AROUND
30 KT ARE EXPECTED OVER THE OPEN WATERS. WILL ISSUE A SMALL CRAFT
ADVISORY FOR LATE THIS MORNING THROUGH EARLY THIS EVENING FOR THE
INDIANA AND ILLINOIS NEARSHORE WATERS.
HIGH PRESSURE BUILDS ACROSS THE LAKE LATE TONIGHT AND WILL ALLOW
WINDS TO DIMINISH BRIEFLY. NEXT LOW PRESSURE SYSTEM BEGINS TO
DEEPEN OVER THE PLAINS TUESDAY AND PASSES OVER SOUTHERN LAKE
MICHIGAN WEDNESDAY. THIS SYSTEM MAY BRING A FEW THUNDERSTORMS TO
SOUTHERN LAKE MICHIGAN...WITH SOUTHEAST TO EASTERLY GALES AHEAD OF
THE LOW ON WEDNESDAY. ANOTHER AREA OF LOW PRESSURE WILL PASS OVER
LAKE MICHIGAN LATE FRIDAY INTO SATURDAY. DETAILS OF THIS SYSTEM
ARE STILL UNCERTAIN...BUT THERE IS ONCE AGAIN POTENTIAL FOR GALES
ACROSS THE LAKE. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...6 AM MONDAY TO 4 PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
156 AM CST MON FEB 27 2012
.DISCUSSION...
916 PM CST
SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT
DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST
AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING
AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE
AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN
NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT
ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE
FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY
ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL
PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN
GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER
THE FRONT.
A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS
DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR
WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE
MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST
CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A
GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT
CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY
OVERNIGHT AND SLOWLY SHIFT EAST.
THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE
DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT
ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES
BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE
BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING
MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE.
//PREV DISCUSSION...
320 PM CST
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN
WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE
UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS
PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED
FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH
STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN
CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH
MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT
COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER.
HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE
SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED
TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO
BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES
THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL
EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT
TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT
ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD
COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN
PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN
BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO
THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER
20S TO LOWER 30S ELSEWHERE.
FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH
WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH
PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS.
SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF
I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL
DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS
THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND
ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS
CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE
MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE
WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN
SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND
UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE
THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO
OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE
THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING
WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE
NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND
MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE
EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY
AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL
EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE
THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK
THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES
THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES
IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE
PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS
THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME
LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM
FOR WEDNESDAY AFTERNOON AND EVENING.
FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH
SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN
INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE.
THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO
SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM
WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC
LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO
CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER
CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR
THE NORTHERN PORTIONS OF THE CWA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* LIGHT SW-WSW WIND BECOMING W WITH SPORADIC GUSTS 15-20 KTS
DURING PREDAWN...THEN BECOMING GUSTY 20-25 KTS AFTER SUNRISE
BEFORE DIMINISHING STEADILY IN THE AFTERNOON.
* LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR
CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY
MONDAY.
TRS
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH
SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT
THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE
FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST
BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL
MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE.
AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER
PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST
WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW
MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING
AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING
WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON
HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE
TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS
LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET.
WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR
MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW
LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME
FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL
RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY
INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING...
THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST
A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY
CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* HIGH CONFIDENCE IN WIND TRENDS...THOUGH MODERATE CONFIDENCE IN
SPORADIC GUST SPEEDS PRIOR TO SUNRISE.
* HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD.
* LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN
STRATOCU DECK MID-MORNING/MIDDAY.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR
POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT.
WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE
OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE.
SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE.
RATZER
&&
.MARINE...
320 PM CST
WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW
GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL
CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN
HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER
PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW.
WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT
PASSES OVER THE LAKE AROUND MIDNIGHT.
HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON
AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM
NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN
LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES
ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING.
WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE
MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL
STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE
SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE
BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE
LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL
SOLUTIONS...KEPT WINDS AT LOW GALES.
IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE
SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS
SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT
WINDS AT SUB GALES FOR NOW.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1057 PM CST SUN FEB 26 2012
.DISCUSSION...
916 PM CST
SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT
DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST
AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING
AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE
AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN
NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT
ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE
FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY
ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL
PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN
GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER
THE FRONT.
A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS
DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR
WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE
MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST
CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A
GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT
CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY
OVERNIGHT AND SLOWLY SHIFT EAST.
THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE
DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT
ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES
BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE
BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING
MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE.
//PREV DISCUSSION...
320 PM CST
FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN
WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE
UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS
PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED
FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH
STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN
CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH
MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN
PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT
COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER.
HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE
SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED
TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO
BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES
THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL
EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT
TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT
ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD
COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN
PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN
BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO
THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER
20S TO LOWER 30S ELSEWHERE.
FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH
WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH
PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS.
SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE
NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF
I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL
DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS
THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND
ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS
CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE
MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE
WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN
SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND
UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE
THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO
OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE
THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING
WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE
NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND
MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE
EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY
AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL
EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE
THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK
THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES
THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES
IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE
PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS
THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME
LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM
FOR WEDNESDAY AFTERNOON AND EVENING.
FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH
SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN
INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE.
THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO
SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM
WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC
LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO
CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER
CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR
THE NORTHERN PORTIONS OF THE CWA.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WEST WINDS...SPORADIC GUSTS 15-20 KTS POSSIBLE OVERNIGHT
BECOMING MORE GUSTY 20-25 KTS AFTER SUNRISE BEFORE DIMINISHING
STEADILY IN THE AFTERNOON.
* LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR
CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY
MONDAY.
RATZER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH
SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT
THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE
FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST
BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL
MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE.
AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER
PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST
WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW
MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING
AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING
WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON
HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE
TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS
LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET.
WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR
MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW
LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME
FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL
RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY
INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING...
THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST
A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY
CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN OVERALL WIND TREND...THOUGH LOW CONFIDENCE IN
SPORADIC GUST SPEEDS PRIOR TO SUNRISE.
* HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD.
* LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN
STRATOCU DECK MONDAY MID-MORNING/MIDDAY.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR
POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT.
WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE
OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE.
THURSDAY...VFR.
FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE.
SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE.
RATZER
&&
.MARINE...
320 PM CST
WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW
GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL
CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN
HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER
PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW.
WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT
PASSES OVER THE LAKE AROUND MIDNIGHT.
HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON
AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM
NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN
LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES
ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING.
WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE
MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL
STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE
SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE
BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE
LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL
SOLUTIONS...KEPT WINDS AT LOW GALES.
IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE
SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS
SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT
WINDS AT SUB GALES FOR NOW.
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1137 PM CST SUN FEB 26 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT RANGE FORECAST - TONIGHT AND MONDAY...
CLEAR SKIES AND W-NW DOWNSLOPE WINDS HAVE ALLOWED SURFACE
TEMPERATURES TO RISE INTO THE UPPER 50S TO MID 60S ACROSS MOST OF
NORTHEAST KANSAS. EXPECT THE WARM AND DRY CONDITIONS TO PERSIST FOR
THE REST OF THE AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO THE
NORTHERN PLAINS AND NOSE INTO THE FORECAST AREA BRINGING CLEAR SKIES
OVERNIGHT WITH CALM WINDS. DO NOT EXPECT MUCH IN THE WAY OF COLD AIR
ADVECTION...BUT RADIATIONAL COOLING WILL ALLOW THE BOUNDARY LAYER TO
COOL TO BELOW FREEZING.
EXPECT SOME COLD AIR ADVECTION TO TRICKLE INTO THE AREA BEHIND THE
VERY LIGHT NORTHERLY FLOW FOR MONDAY. MIXING NOT QUITE AS DEEP ON
MONDAY AS SUNDAY...SO THAT FACTOR IN COMBINATION WITH THE WEAK COLD
AIR ADVECTION WILL KEEP TEMPS ON MONDAY MORE SEASONAL. CLOUDS WILL
BE ON THE INCREASE BY MONDAY AFTERNOON/EVENING AS WARM/MOIST AIR
GETS ADVECTED NORTHWARD. CONDENSATION AS A RESULT OF THE ISENTROPIC
LIFT ASSOCIATED WITH THE WARM AIR ADVECTION WILL LIKELY BEGIN
SHORTLY AFTER NOON...WHICH WILL ALSO AID IN KEEPING TEMPERATURES
FROM RISING MUCH HIGHER THAN THE LOWER 50S.
JL
LEIGHTON
LONG TERM - MONDAY NIGHT THROUGH SUNDAY...
MONDAY NIGHT THROUGH TUESDAY NIGHT...
MODEL AGREEMENT IS NOW FAIRLY GOOD IN THE TRACK OF A POTENT
NEGATIVELY TILTED UPPER LEVEL TROUGH. THE SURFACE LOW WILL TRACK
WELL NORTH OF THE LOCAL FORECAST AREA WITH A SHARP FAST MOVING DRY
LINE CROSSING THE AREA BETWEEN 21Z TUESDAY AND 03Z WEDNESDAY.
WARM MOIST ADVECTION WILL TAKE PLACE ON MONDAY NIGHT AND TUESDAY
MORNING AHEAD OF THE SYSTEM WITH SHOWERS AND A FEW ELEVATED
THUNDERSTORMS EXPECTED TO DEVELOP AND MOVE INTO THE AREA MONDAY
NIGHT. THIS ACTIVITY SHOULD ALL REMAIN BELOW SEVERE LIMITS WITH
SOME LOW END POTENTIAL FOR SMALL HAIL THROUGH NOON ON TUESDAY.
WHILE CLOUD COVER WILL BE ABUNDANT THROUGH THE DAY ON TUESDAY...
TEMPERATURES WILL WARM NICELY WITH AMPLE WARM ADVECTION. THE CLOUD
LAYER WILL ALSO BE RELATIVELY SHALLOW AND LOW BY TUESDAY
AFTERNOON...AND A FEW BREAKS WILL BE POSSIBLE AHEAD OF THE DRY
LINE BY LATE AFTERNOON. SURFACE DEWPOINTS WILL CLIMB INTO THE MID
50S BY LATE TUESDAY ACROSS MUCH OF THE FORECAST AREA WITH TEMPS IN
THE UPPER 50S AND LOW 60S. EXPECT THE DRY LINE TO ENTER THE
FORECAST AREA SOMETIME BETWEEN 21Z AND 00Z...AND PUSH EAST INTO
MISSOURI ONLY 3 TO 4 HOURS LATER. CONVECTION IS EXPECTED TO
DEVELOP IMMEDIATELY ALONG THE DRY LINE BOUNDARY BY LATE AFTERNOON
AND CROSS THE FORECAST AREA...BUT SUBSTANTIAL UNCERTAINTY EXISTS
REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS.
CURRENT INDICATIONS ARE THAT 200-500 J/KG OF SURFACE BASED CAPE
WILL BE PRESENT IN A NARROW BAND NEAR THE BOUNDARY. THOSE ARE
MEAGER VALUES BUT THE MAJORITY OF THIS INSTABILITY WILL BE IN THE
LOWEST 15000 FEET OF THE ATMOSPHERE WITH MAX LIFTED INDEX VALUES
IN THAT LAYER APPROACHING -5. THIS WOULD SUGGEST THE POTENTIAL FOR
SOME STRONGER SHALLOW UPDRAFTS. SHEAR THROUGH THE DEPTH OF THE
CONVECTIVE LAYER...ABOUT 0-4 KM...IS 50-60 KTS WHILE 0-1 KM SHEAR
IS 30-40 KTS. THESE VALUES ARE MORE THAN SUFFICIENT TO PRODUCE
ORGANIZED STORMS WITH SOME POTENTIAL FOR LOW TOPPED SUPERCELL
DEVELOPMENT. HOWEVER...THE UNIDIRECTIONAL NATURE OF THE SHEAR MAY
SUGGEST MORE OF A QUASI-LINEAR DEVELOPMENT WITH A BIT MORE
POTENTIAL FOR DAMAGING WINDS AT THE SURFACE. IT WILL BE DIFFICULT
TO GET LARGE HAIL WITH SUCH SHALLOW UPDRAFTS PERHAPS HAVING
TROUBLE CLIMBING ABOVE THE -20C LEVEL...BUT AT LEAST SMALL HAIL
WOULD REMAIN POSSIBLE. TORNADO POTENTIAL IS NON-ZERO...BUT HIGHLY
DEPENDENT UPON DEVELOPMENT OF MORE ROBUST UPDRAFTS...AND STRONG
UPDRAFT POTENTIAL IS THE MOST SIGNIFICANT UNCERTAINTY WITH THIS
FORECAST.
WEDNESDAY THROUGH SUNDAY...
WILL DRY OUT QUICKLY BEHIND THIS SYSTEM AND REMAIN DRY WITH A
SLIGHT COOL DOWN FOR WEDNESDAY AND A QUICK RECOVERY WITH WARM
TEMPS AGAIN ON THURSDAY. A WEAKER STORM SYSTEM WILL THEN CROSS THE
PLAINS THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM DOES NOT HAVE A
PARTICULARLY STRONG PRECIP SIGNAL BUT APPEARS WORTHY OF AT LEAST A
SLIGHT CHANCE OF LIGHT RAIN WITH PERHAPS A MIX TO LIGHT SNOW
THURSDAY NIGHT. IT DOES NOT APPEAR TO BE A HIGH IMPACT EVENT AT
THIS TIME. EXPECT DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR
SATURDAY AND SUNDAY.
BARJENBRUCH
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGH THE TERMINAL FCST PERIOD
WITH ONLY SCT HIGH CLOUDS EXPECTED. WILL KEEP WINDS NORTH 6 TO 8 KTS
OVERNIGHT WITH SECOND PUSH OF COOLER AIR. WILL THEN GRADUALLY VEER
TO THE NORTHEAST 6-10KTS BEYOND 12Z...THEN EASTERLY AROUND 10 KTS
ON THE BACKSIDE OF RETREATING SFC HIGH. FOR NOW WILL ONLY INCLUDE
SCT CIRRUS UNTIL 12Z FOLLOWED BY BKN MID LEVEL DECK BY 00Z/28
AROUND 10 KFT...ALTHOUGH LOWER CIGS EXPECTED JUST BEYOND THE END
OF THIS FCST PERIOD.
&&
.FIRE WEATHER...
DEEP MIXING HAS COMMENCED ACROSS ALL OF NORTHEAST KANSAS BRINGING
VERY DRY LOW LEVEL AIR TO THE SURFACE. RUC SOUNDINGS INDICATE THAT
THE ATMOSPHERE HAS MIXED TO APPROXIMATELY 800 MB OR 5600 FEET. W-NW
WINDS AT THE SURFACE CONTAIN QUITE A BIT OF A DOWNSLOPE TRAJECTORY
WHICH HAS AIDED IN WARMING AND DRYING THE AIR. AS A RESULT RELATIVE
HUMIDITY VALUES HAVE DROPPED INTO THE MID TEENS THIS AFTERNOON...AND
WILL LIKELY REMAIN IN THE MIDDLE TEENS THROUGH AT LEAST SUNSET.
WINDS THROUGHOUT THE DAY HAVE BEEN RELATIVELY LIGHT AS OBSERVATIONS
HAVE INDICATED 10 TO 15 MPH W-NW WINDS. DUE TO THE DEEP MIXING SOME
WIND GUSTS OF UP TO 20-25 MPH ARE POSSIBLE...BUT THOSE GUSTS WILL BE
RATHER INFREQUENT. RH VALUES WILL START TO RISE ONCE SURFACE
TEMPERATURES BEGIN TO COOL RIGHT AROUND SUNSET.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
951 PM MST SUN FEB 26 2012
.UPDATE...
ISSUED AT 651 PM MST SUN FEB 26 2012
SFC HIGH NOW SETTLING OVER THE AREA AS WINDS HAVE RAPIDLY
DECREASED. 00Z SOUNDINGS INDICATE DRY AIR MASS IN PLACE AT DNR AND
TO A LESSER EXTENT DDC...WITH LOW LEVEL MIXING RATIOS NOTICEABLY
HIGHER AT KLBF. WITH THESE OBSERVATIONS AND EXPECTED WIND
FIELD...STILL EXPECT A FAIRLY SHARP NORTHEAST TO SOUTHWEST TD
GRADIENT THROUGH THE EVENING...ALTHOUGH THERE WILL BE SOME
RECOVERY WITH LOSS OF DEEP MIXING. WHILE THINGS WILL BE SLIGHTLY
MORE HUMID...MOISTURE PROFILES DO NOT LOOK DEEP ENOUGH TO PREVENT
TEMPS FROM DROPPING SHARPLY GIVEN LIGHT WINDS...DRY AIR AND
MINIMAL HIGH CLOUD COVER. HAVE LOWERED TEMPS 4-5 DEGREES AT
SEVERAL LOCATIONS...ESPECIALLY NORMAL COLD SPOTS LIKE WESTERN
CHEYENNE COUNTY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 236 PM MST SUN FEB 26 2012
LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN
UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL
JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE
OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE
STRONGER WINDS ABOVE THE SURFACE MIX DOWN.
THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE
AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING
THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH
NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE
OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS
SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE
SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH.
WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE
COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST
NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS.
MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST
EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY
MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN
THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE
BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I
DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED
TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST
CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE
WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING
AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT
PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX
COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS
ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD
KEEP CONDITIONS BELOW ADVISORY LEVELS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 PM MST SUN FEB 26 2012
TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE
INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY.
GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING
UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY
PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY
WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE
TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH
GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA.
STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE
SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING
CRITERIA WINDS (GUSTS 60MPH OR GREATER).
WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION
WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS
CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE
REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED
OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF
THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH
TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND
SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL
BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD
TEMPERATURES RETURNING TO THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 951 PM MST SUN FEB 26 2012
PREVAILING WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...BECOMING
SOUTHEASTERLY AFTER SUNRISE. AS DAYTIME MIXING INCREASES...WINDS
WILL INCREASE AND BEGIN GUSTING...TAKING ON MORE OF A SOUTHERLY
COMPONENT BY MIDDAY. CEILINGS WILL DECREASE IN THE LATE AFTERNOON
INTO THE EVENING AHEAD OF AN UPPER LEVEL LOW...LOWERING INTO THE
MVFR RANGE BY LATE IN THE PERIOD. PRECIPITATION WILL ALSO BE
POSSIBLE LATE IN THE PERIOD...BUT CONFIDENCE IS TOO LOW AT THIS
TIME TO PLACE PRECIPITATION AT THE TERMINALS DURING THIS TAF
CYCLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
KS...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...JTL/DR
LONG TERM....DR
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 PM CST SUN FEB 26 2012
.AVIATION.../06Z TAF ISSUANCE/
IFR/MVFR CONDITIONS WILL SLOWLY IMPROVE BY DAYBREAK AS THE SNOW
DIMINISHES FROM WEST TO EAST. INCLUDED TEMPO GROUPS AT DLH AND HYR
FOR IFR CEILINGS FROM 06Z TO 10Z. GUSTY NORTHWEST WINDS OVER BRD
WILL CONTINUE THROUGH 10Z. MAINLY MVFR CEILINGS FOR THE FIRST HALF
OF MONDAY BEFORE THE CLOUDS BREAK AND LIFT BY LATE MONDAY
AFTERNOON. WINDS WILL ALSO DECREASE THROUGHOUT THE DAY.
&&
.PREV DISCUSSION... /ISSUED 1033 PM CST SUN FEB 26 2012/
SHORT TERM...
RADAR AND OBSERVATIONS CONTINUE TO SHOW THE SNOW DECREASING IN
INTENSITY...WITH THE EXCEPTION OF OVER THE SOUTH SHORE OF LAKE
SUPERIOR...AND OVER PARTS OF THE ARROWHEAD. THE LOW WAS MOVING
TOWARD UPPER MICHIGAN/LAKE SUPERIOR THIS EVENING AND HAD
WEAKENED TO 1008MB. IF CURRENT TRENDS CONTINUE...WE WILL DROP THE
HEADLINES FOR CARLTON/SOUTHERN SAINT LOUIS AND PERHAPS THE REST OF
NORTHERN AND CENTRAL SAINT LOUIS COUNTIES AS WELL SHORTLY. WE WILL LEAVE
THE HEADLINES GOING FOR THE ARROWHEAD...AND SOUTH SHORE. WE`RE
STILL ON THE FENCE REGARDING PINE COUNTY. KDLH VELOCITY REVEALS
WINDS HAVE COME AROUND TO NORTH-NORTHWEST WITH SPEEDS AROUND 20 KT
IN THE LOWEST COUPLE THOUSAND FEET. NO CLEAR EVIDENCE YET IN RADAR
OF THE GRAVITY WAVE INDUCED AREA OF SNOWFALL...BUT RUC SUGGESTED
IT MAY TAKE A FEW MORE HOURS TO DEVELOP. WE ALSO MAY HAVE TO
INCREASE SNOW TOTALS A BIT ALONG THE SOUTH SHORE AS SPOTTERS HAVE
REPORTED HEAVIER SNOW THERE OVER THE PAST FEW HOURS...IRON BELT
HAD 2 INCHES IN A 3 HOUR PERIOD. NORTHERLY WINDS WITH DELTA-T`S
AROUND 13-15C AND THE LOW PRESSURE WILL CONTINUE TO PRODUCE
MODERATE SNOW SHOWERS ALONG PORTIONS OF THE SOUTH SHORE TONIGHT.
PREV DISCUSSION... /ISSUED 701 PM CST SUN FEB 26 2012/
SHORT TERM...
MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON
RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE
SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB
PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP
OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY
DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM
AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL
WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE
HEADLINES IN THE WEST.
SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING
DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS
EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT
REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE
POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT
OVER THAT AREA...INTO NORTHWEST WISCONSIN.
SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST
TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO
KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH
THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T
VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM
THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER
TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL
ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST
PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME
NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG
A WAVE WILL RESULT.
PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/
AVIATION.../0Z TAF ISSUANCE/
CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY
IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND
HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO
SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST
LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS
IMPROVING TO LOW END VFR BY MONDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/
WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA
WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST
LOUIS/CARLTON COUNTIES...
SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS
COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS.
LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS
COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS
PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF
MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A
DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY.
85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS
COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER
AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS
FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS
WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A
SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN
EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY.
TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT.
EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS
AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF
WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS
WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA.
SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA.
HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON
RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP
SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF
MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS.
TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER
BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD
COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT.
EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED
TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH
WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER
AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME
DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES
ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA
ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW
BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE
SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING
THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION
TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING
ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER
AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY
HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME
POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO
THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO
TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT
WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE
ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE
AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY
STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT
RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING
LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I
WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT
SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO
TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM
SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED
WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS
ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT
THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN.
&&
.POINT TEMPS/POPS...
DLH 27 15 23 12 / 100 100 10 10
INL 24 9 19 4 / 100 90 20 10
BRD 27 15 22 16 / 100 70 10 10
HYR 34 20 26 10 / 70 70 10 10
ASX 30 23 26 11 / 70 90 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ038.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MNZ025-033>038.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ012-020-021.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR WIZ001>004-006>009.
&&
$$
SHORT TERM...MELDE
AVIATION...KK
AREA FORECAST DISCUSSION
NWS DULUTH MN
1033 PM CST SUN FEB 26 2012
.SHORT TERM...
RADAR AND OBSERVATIONS CONTINUE TO SHOW THE SNOW DECREASING IN
INTENSITY...WITH THE EXCEPTION OF OVER THE SOUTH SHORE OF LAKE
SUPERIOR...AND OVER PARTS OF THE ARROWHEAD. THE LOW WAS MOVING
TOWARD UPPER MICHIGAN/LAKE SUPERIOR THIS EVENING AND HAD
WEAKENED TO 1008MB. IF CURRENT TRENDS CONTINUE...WE WILL DROP THE
HEADLINES FOR CARLTON/SOUTHERN SAINT LOUIS AND PERHAPS THE REST OF
NORTHERN AND CENTRAL SAINT LOUIS COUNTIES AS WELL SHORTLY. WE WILL LEAVE
THE HEADLINES GOING FOR THE ARROWHEAD...AND SOUTH SHORE. WE`RE
STILL ON THE FENCE REGARDING PINE COUNTY. KDLH VELOCITY REVEALS
WINDS HAVE COME AROUND TO NORTH-NORTHWEST WITH SPEEDS AROUND 20 KT
IN THE LOWEST COUPLE THOUSAND FEET. NO CLEAR EVIDENCE YET IN RADAR
OF THE GRAVITY WAVE INDUCED AREA OF SNOWFALL...BUT RUC SUGGESTED
IT MAY TAKE A FEW MORE HOURS TO DEVELOP. WE ALSO MAY HAVE TO
INCREASE SNOW TOTALS A BIT ALONG THE SOUTH SHORE AS SPOTTERS HAVE
REPORTED HEAVIER SNOW THERE OVER THE PAST FEW HOURS...IRON BELT
HAD 2 INCHES IN A 3 HOUR PERIOD. NORTHERLY WINDS WITH DELTA-T`S
AROUND 13-15C AND THE LOW PRESSURE WILL CONTINUE TO PRODUCE
MODERATE SNOW SHOWERS ALONG PORTIONS OF THE SOUTH SHORE TONIGHT.
.PREV DISCUSSION... /ISSUED 701 PM CST SUN FEB 26 2012/
SHORT TERM...
MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON
RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE
SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB
PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP
OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY
DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM
AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL
WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE
HEADLINES IN THE WEST.
SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING
DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS
EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT
REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE
POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT
OVER THAT AREA...INTO NORTHWEST WISCONSIN.
SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST
TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO
KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH
THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T
VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM
THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER
TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL
ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST
PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME
NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG
A WAVE WILL RESULT.
PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/
AVIATION.../0Z TAF ISSUANCE/
CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY
IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND
HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO
SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST
LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS
IMPROVING TO LOW END VFR BY MONDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/
WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA
.WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST
LOUIS/CARLTON COUNTIES...
SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS
COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS.
LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS
COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS
PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF
MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A
DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY.
85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS
COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER
AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS
FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS
WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A
SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN
EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY.
TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT.
EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS
AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF
WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS
WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA.
SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA.
HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON
RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP
SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF
MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS.
TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER
BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD
COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT.
EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED
TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH
WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER
AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME
DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES
ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA
ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW
BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE
SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING
THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION
TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING
ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER
AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY
HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME
POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO
THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO
TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT
WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE
ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE
AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY
STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT
RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING
LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I
WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT
SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO
TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM
SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED
WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS
ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT
THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN.
AVIATION.../18Z TAF ISSUANCE/
A WINTER STORM WILL CONTINUE TO IMPACT THE NORTHLAND OVER MUCH OF
THE TAF PERIOD. AT THIS POINT...IT APPEARS THAT THE MOST DRAMATIC
VISIBILITY RESTRICTIONS WOULD BE ACROSS THE IRON RANGE AND THE
ARROWHEAD...WHERE A DEFORMATION AXIS WILL SET UP AND ROTATE
THROUGH THAT AREA. AREAS TO THE SOUTH AND FAR NORTH WILL SEE MORE
EPISODIC PERIODS OF HEAVIER SNOW. KHIB LOOKS TO SEE THE MOST
DRAMATIC VSBY RESTRICTIONS. OVERALL...FAIRLY WIDESPREAD MVFR TO
EVEN LIFR CONDITIONS CAN BE EXPECTED. CONDITIONS WILL IMPROVE
LATER TONIGHT AND ON MONDAY MORNING.
&&
.POINT TEMPS/POPS...
DLH 15 23 12 28 / 100 10 10 60
INL 9 19 4 28 / 90 20 10 10
BRD 15 22 16 30 / 70 10 10 70
HYR 18 26 10 32 / 70 10 10 60
ASX 21 26 11 31 / 90 30 10 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ038.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MNZ025-033>038.
WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ011-012-
019>021-037.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR WIZ001>004-006>009.
&&
$$
SHORT TERM...MELDE
LONG TERM....DAP
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EST MON FEB 27 2012
.UPDATE...
WE ADDED THE POSSIBILITY OF ISOLATED THUNDERSTORMS FOR THE CENTRAL
AND WESTERN SECTIONS OF SOUTH FLORIDA WITH THIS MORNING UPDATE.
THE MAIN PRECLUDING FACTOR FOR THE FORMATION OF ISOLATED
THUNDERSTORMS IS A MID LEVEL CAP AROUND 700 MB. HOWEVER, SOME OF
THE CAP COULD BE ERODED BY THE COMBINATION OF COLD ADVECTION WEST
OF THE TROUGH LINE AND WARM SURFACE TEMPERATURES IN THE MID 80S
COMBINED WITH BOUNDARY COLLISIONS. THE COMBINATION OF THE EAST FLOW WITH THE
FORMATION OF A WEST COAST SEA BREEZE AND LAKE BREEZE WILL ENHANCE
THE THUNDERSTORM POTENTIAL FOR GLADES, HENDRY, CENTRAL-WESTERN
COLLIER, AS WELL AS WESTERN PALM BEACH AND BROWARD COUNTIES.
RELATED TO THIS CHANGE POPS AND SKY WERE ALSO UPDATED. IF ALL THE
CORRECT INGREDIENTS COME TOGETHER SUCH AS SIGNIFICANT EROSION OF
THE CAP, ENHANCED BOUNDARY COLLISIONS, AND STRONGER COLD ADVECTION
ALOFT THAN FORECAST, AS THE MOST IMPORTANT FACTORS...SMALL HAIL
COULD OCCUR IN SOME SPOTS OF THE NORTHERN COUNTIES. HOWEVER, THE
CONFIDENCE FOR HAIL IS LOW AT THIS TIME FOR SOUTH FLORIDA.
&&
.PREV DISCUSSION... /ISSUED 515 AM EST MON FEB 27 2012/
AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA
WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS
KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT
SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR
VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED
E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z.
SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE
9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025
BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS
BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF.
PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/
DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH
AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS
MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS
A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS
NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH
MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE
REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW
AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM
BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER
MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS
DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE
FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST
STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT
FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN
A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING
THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA,
THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID
LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN
TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN
ACROSS FL THROUGH THE WEEK.
BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO
CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH
THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY
BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF
OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF
SHRA.
MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE
OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT
SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE
FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT
AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON.
FIRE WEATHER...NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 83 69 / 30 20 10 10
FORT LAUDERDALE 82 73 83 72 / 30 20 10 10
MIAMI 83 72 84 71 / 20 20 10 10
NAPLES 85 66 86 65 / 30 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS MIAMI FL
515 AM EST MON FEB 27 2012
.AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA
WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS
KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT
SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR
VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED
E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z.
SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE
9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025
BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS
BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF.
&&
.PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/
DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH
AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS
MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS
A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS
NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH
MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE
REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW
AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM
BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER
MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS
DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE
FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST
STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT
FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN
A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING
THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA,
THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID
LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN
TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN
ACROSS FL THROUGH THE WEEK.
BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO
CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH
THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY
BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF
OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF
SHRA.
MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE
OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT
SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE
FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT
AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON.
FIRE WEATHER...NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 83 69 / 40 20 10 10
FORT LAUDERDALE 82 73 83 72 / 30 20 10 10
MIAMI 83 72 84 71 / 20 20 10 10
NAPLES 85 66 86 65 / 30 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1004 AM EST MON FEB 27 2012
.UPDATE...
BEST MOISTURE AND LIFT EXITING CENTRAL GA WITH PRECIP CHANCES
DIMINISHING OR HAVE ENDED. STILL GOOD MOISTURE IN PLACE ACROSS
CENTRAL GA AND YOU CAN NOT COMPLETELY RULE OUT SPRINKLES...BRIEF LIGHT
RAIN OR DRIZZLE FOR SOME AREAS. FORECAST HIGH TEMPERATURES RUNNING
NEAR TO SLIGHTLY ABOVE NORMAL. BDL
&&
.PREV DISCUSSION... /ISSUED 639 AM EST MON FEB 27 2012/
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS
MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK
SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL
AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS
SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE
MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW
SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA.
ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE
GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR
INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE
NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE...
A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT
LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE
NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED
COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW
GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL
AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA
BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH
THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY
EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE
300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK
SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL
NORMS THROUGH THE SHORT TERM.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH
AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS
N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW
PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE
INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS
WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW
CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE
SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH
THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO
FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE.
TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7.
AVIATION...
12Z UPDATE...
CIGS HAVE BEEN COMING DOWN ALL NIGHT AS ADVERTISED WITH MOST SITES
IFR...BUT ATL BRIEFLY IN LIFR AT TIMES. FEEL PRESENCE OF DZ AT ATL
WILL LEAD TO ADDITIONAL INSTANCES OF LIFR THROUGH 14Z AND WILL
CARRY IN TEMPO. SLOW IMPROVEMENT FOR ALL SITES THEREAFTER WITH
MVFR BY 18Z. LOCAL MODELS FINALLY COMING AROUND TO INDICATE A
SHIFT TO NW WINDS THIS AFTERNOON AND HAVE INDICATED SUCH IN NEWEST
TAF SET. SHOULD BE BRIEF THOUGH AS A SHIFT BACK TO NE IS IN STORE
FOR THE OVERNIGHT HOURS. SOME INDICATIONS ALREADY OF SOME LOWERING
CIGS FOR TONIGHT INTO TUE MORNING AND WILL BEGIN TO INDICATE A
DETERIORATING TREND.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIG IMPROVEMENT AND WIND SHIFT.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 44 71 53 / 5 0 20 30
ATLANTA 64 50 71 57 / 0 0 20 30
BLAIRSVILLE 63 40 66 50 / 0 0 20 50
CARTERSVILLE 64 42 71 53 / 0 0 20 40
COLUMBUS 66 50 75 58 / 20 5 10 20
GAINESVILLE 63 47 67 54 / 0 0 20 40
MACON 65 47 73 56 / 20 5 10 10
ROME 66 42 72 54 / 0 0 20 50
PEACHTREE CITY 64 42 71 55 / 5 0 20 30
VIDALIA 65 52 73 57 / 30 5 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
639 AM EST MON FEB 27 2012
.PREV DISCUSSION... /ISSUED 414 AM EST MON FEB 27 2012/
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING
EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER
THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE
ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME
SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO
THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING
INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE
MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES
STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION.
THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING
WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW
DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY
12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES
THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO
THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED.
PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT
WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY
AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE
ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED
THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN
18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL
BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH
AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS
N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW
PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE
INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS
WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW
CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE
SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH
THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO
FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE.
TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7.
&&
.AVIATION...
12Z UPDATE...
CIGS HAVE BEEN COMING DOWN ALL NIGHT AS ADVERTISED WITH MOST SITES
IFR...BUT ATL BRIEFLY IN LIFR AT TIMES. FEEL PRESENCE OF DZ AT ATL
WILL LEAD TO ADDITIONAL INSTANCES OF LIFR THROUGH 14Z AND WILL
CARRY IN TEMPO. SLOW IMPROVEMENT FOR ALL SITES THEREAFTER WITH
MVFR BY 18Z. LOCAL MODELS FINALLY COMING AROUND TO INDICATE A
SHIFT TO NW WINDS THIS AFTERNOON AND HAVE INDICATED SUCH IN NEWEST
TAF SET. SHOULD BE BRIEF THOUGH AS A SHIFT BACK TO NE IS IN STORE
FOR THE OVERNIGHT HOURS. SOME INDICATIONS ALREADY OF SOME LOWERING
CIGS FOR TONIGHT INTO TUE MORNING AND WILL BEGIN TO INDICATE A
DETERIORATING TREND.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON CIG IMPROVEMENT AND WIND SHIFT.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 44 71 53 / 30 0 20 30
ATLANTA 64 50 71 57 / 20 0 20 30
BLAIRSVILLE 63 40 66 50 / 10 0 20 50
CARTERSVILLE 64 42 71 53 / 10 0 20 40
COLUMBUS 66 50 75 58 / 30 5 10 20
GAINESVILLE 63 47 67 54 / 20 0 20 40
MACON 65 47 73 56 / 50 5 10 10
ROME 66 42 72 54 / 5 0 20 50
PEACHTREE CITY 64 42 71 55 / 20 0 20 30
VIDALIA 65 52 73 57 / 80 5 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
552 AM CST MON FEB 27 2012
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THIS MORNING...AN UPPER LOW OVER THE UPPER GREAT LAKES WILL
CONTINUE TO MOVE EAST OVER THE NEW ENGLAND STATES BY MIDNIGHT
TONIGHT. A SFC HIGH PRESSURE RIDGE WILL ADVANCE OVER THE WESTERN
GREAT LAKES AND MIDWEST TODAY. SO A QUIET AND COOL DAY TODAY WITH
AFTERNOON HIGH TEMPERATURES IN THE 20S. THE LATEST WATER VAPOR
SATELLITE IMAGERY SHOWED A DEEPENING UPPER LOW OVER THE WEST COAST
WITH A STRONG UPPER LEVEL JET ROUNDING THE BASE OF THE UPPER LOW.
THIS LOW WILL CONTINUE TO STRENGTHEN OVER THE SOUTHERN ROCKIES
TODAY...BEFORE LIFTING INTO THE CENTRAL PLAINS ON TUESDAY.
TUESDAY AND WEDNESDAY TIMEFRAME...MODELS ARE IN GENERAL AGREEMENT
WITH THE POTENTIAL WINTER STORM. THE ONLY CHALLENGE IS DETERMINING
PRECIPITATION TYPES TUESDAY NIGHT. STILL BELIEVE THE BULK OF THE
PRECIPITATION WILL BE MAINLY SNOW FOR MUCH OF OUR AREA. THE LATEST
GEM-NHEM MODEL HAS THE SURFACE LOW OVER SOUTHEAST MN...LITTLE
FURTHER NORTH THAN THE NAM..GFS AND EC MODELS. THUS PREFERRED A
BLEND OF THE EC/GFS/NAM FOR POSITION AND TRACK OF THE SURFACE
LOW. THESE MODELS BRING THE SURFACE LOW ALONG THE IOWA/MINNESOTA
BORDER. THIS WILL PLACE MUCH OF OUR FORECAST IN BULLS-EYE OR CLOSE
IN RECEIVING 8+ INCHES OF SNOW...WITH PARTS OF WEST CENTRAL-
CENTRAL MN AND WESTERN WISCONSIN POSSIBLY OVER A FOOT. MODELS
CONTINUE TO SUPPORT LIQUID PRECIP TOTALS OF ONE TO TWO INCHES OVER
CENTRAL MN. WITH MIXING RATIOS IN THE 3-4 G/KG RANGE AND SNOW
ACCUMULATIONS VARYING 1.0-1.5 INCHES PER HOUR...SIX HOURLY
ACCUMULATION TOTALS COULD EASILY EXCEED OVER 10 INCHES. DUE TO
UNCERTAINTY ON THE TRACK AND PRECIPITATION TYPES DUE THE ENTIRE
EVENT...WILL HOLD OFF FROM UPGRADING THE BLIZZARD WATCH AND WINTER
STORM WATCH TO WARNINGS. DAY SHIFT SHOULD HAVE A FIRM GRASP ON THE
TRACK OF THE STORM.
THE SNOW WILL BEGIN TO DIMINISH OVER WESTERN MN DURING THE AFTERNOON
WEDNESDAY AS THE SURFACE LOW MOVES TOWARD THE LOWER GREAT
LAKES...WHILE MODERATE SNOW IS LIKELY TO CONTINUE OVER THE EASTERN
HALF OF THE FORECAST AREA.
ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OVER THE CENTRAL
PLAINS THURSDAY. ECMWF INTENSIFIES THIS LOW PRESSURE SYSTEM AS IT
LIFTS NORTHEAST OVER THE GREAT LAKES FRIDAY NIGHT. THIS SYSTEM
COULD BRING SOME MORE ACCUMULATING SNOWS TO THE EASTERN HALF OF
OUR FORECAST AREA FRIDAY AND FRIDAY NIGHT.
SUNDAY INTO MONDAY...LOOKS DRY AS AN UPPER RIDGE BUILDS OVER THE
NATIONS MIDSECTION.
&&
.AVIATION.../12Z TAF ISSUANCE/
SFC HIGH TO MOVE ACROSS THE TERMINALS...TODAY...RESULTING IN A
RELATIVELY CALM TAF PERIOD...BEFORE A SIGNIFICANT WINTER STORM
IMPACTS THE TERMINALS TUESDAY AFTERNOON INTO WEDNESDAY. BIGGEST
CHALLENGE THIS MORNING DEALS WITH TIMING BACK EDGE OF THE CLOUDS
THROUGH THE TERMINALS. LATEST 11-3.9 SAT IMAGERY SHOWS CLOUDS OVER
WRN MN...AND IN PARTICULAR AROUND RWF ALREADY BREAKING DOWN.
LEANED CLEARING IN TAFS MORE TOWARD THE RUC. LATE IN THE
TAF...WILL JUST SEE MID LEVEL CLOUDS INCREASE AS NEXT STORM SYSTEM
APPROACHES...THOUGH MOST OF THE PRECIP ASSOCIATED WITH IT LOOKS TO
HOLD OFF UNTIL AFTER 18Z TUE. WINDS WILL REMAIN GUSTY FOR THE FIRST
COUPLE HOURS IN THE EAST THIS MORNING...BUT SPEEDS WILL QUICKLY
COME DOWN UNDER 10 KTS AS THE SFC RIDGE MOVES IN. GIVEN THE SPEED
THE RIDGE MOVES THROUGH...WILL SEE WINDS QUICKLY BACK OVER TO THE
SE THIS AFTERNOON/EVENING.
KMSP...BASED ON SURROUNDING OBS...CIGS SHOULD REMAIN ABOVE 017
THIS MORNING...THOUGH A BRIEF PERIOD BELOW THIS LEVEL CAN NOT BE
RULED OUT THROUGH 15Z. BASED ON RUC TIMING...EXPECT CIGS TO CLEAR
BETWEEN 15Z AND 18Z. ARRIVAL OF NEXT SYSTEM CONTINUES TO SLOW IN
THE MODELS...AND SEEING ANY PRECIP EVEN IN THE 15-18Z PERIOD
TUESDAY MAY BE PUSHING IT...BULK OF THE PRECIP LOOKS TO ARRIVE
AFTER 21Z TUE.
//OUTLOOK...TUESDAY THROUGH FRIDAY...
.TUE-WED...CIGS/VSBY BECOMING LIFR. -SN DEV TUESDAY AFTERNOON...
LIKELY TRANSITIONS TO A MIX TUE NIGHT BEFORE GOING BACK TO SN WED
MORNING.
.WED NIGHT-THU...BECOMING VFR.
.FRI...IFR OR LOWER CIGS/VSBY POSSIBLE WITH CHANCE OF -SN.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHISAGO-
DAKOTA-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC-
KANDIYOHI-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON-
NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-
SIBLEY-STEARNS-STEELE-WASECA-WASHINGTON-WATONWAN-WRIGHT.
BLIZZARD WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR CHIPPEWA-DOUGLAS-LAC QUI PARLE-POPE-STEVENS-
SWIFT-TODD-YELLOW MEDICINE.
WI...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR BARRON-CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-
POLK-RUSK-ST. CROIX.
&&
$$
JVM/MPG
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 PM MST MON FEB 27 2012
.SHORT TERM...UPPER TROUGH HEADING TOWARDS THE GREAT BASIN AT THIS
TIME WITH FAIRLY TIGHT SOUTHERLY FLOW ALOFT OVER THE REGION. AT
THE SURFACE...GUSTY SOUTHERLY WINDS CONTINING ACROSS THE
PLAINS MAINLY FROM DENVER EASTWARD. MODELS STILL PERSISTANT WITH
WEAKENING THAT GRADIENT DURING THE EVENING...WITH SURFACE WINDS
DECREASING A RESULT. WILL CONTINUE THIS TREND. SATELLITE SHOWING
MOISTURE CONTINUING TO SPREAD INTO WESTERN COLORADO...WITH RADAR
SHOWING SOME ECHOES ACROSS THE WESTERN MOUNTAINS. NOT ALOT
CURRENTLY HAPPENING OVER THE NORTHERN AND CENTRAL MOUNTAINS...
PERHAPS A FEW ECHOES ACROSS ZONE 31. AS TROUGH MOVES INTO THE
GREAT BASIN THIS EVENING...SHOULD SEE MOISTURE INCREASE AND SNOW
SPREAD ACROSS THE AREA. SOUTHWEST FLOW ALOFT NOT FAVORABLE FOR
GOOD SNOWFALL AND ACCUMULATIONS...BUT WITH INCREASING ASCENT AND
LAPSE RATES...LIKELY POPS SEEM WARRANTED WITH THE HIGHEST POPS FOR
FAVORED ZONE 31. SNOW AMOUNTS TO BE IN THE 1 TO 3 INCH RANGE.
ACROSS PLAINS....SURFACE WINDS TO BECOME SOUTHWEST DURING THE
EVENING AS THE SOUTHWEST GRADIENT INCREASES. MOISTURE TO INCREASE
ACROSS THE AREA BY MIDNIGHT. LOW LEVELS SLOWING MOISTEN OVERNIGHT
AS LOW LEVEL MOISTURE SPREADS NORTHWEST. QUESTION REMAINS HOW MUCH
LOW LEVEL MOISTURE MAKES IT TO THE FOOTHILLS. LATEST RUC AS WELL
AS THE HI RESOLUTION MODELS BRING THE LOW LEVEL MOISTURE INTO
EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES AROUND 10Z...ENOUGH
PERHAPS FOR PATCHY FOG. THIS ALREADY IN THE GRIDS. PRECIP CHANCES
LOW OVERNIGHT...WITH THE BEST CHANCE ACROSS ZONE 38 WHERE SOME
BANDED PRECIP IS POSSIBLE. MAY BE A RAIN/SNOW MIX FOR A FEW HOURS.
ON TUESDAY...THE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION WITH
THE BEST DYNAMICS OCCURRING DURING THE MORNING. OROGRAPHICS
IMPROVE DURING THE AFTERNOON BUT LIFT IS EAST OF THE MOUNTAINS AND
MOISTURE DEPTH DECREASES. STILL A DECENT SHOT OF SNOW EXPECTED FOR
THE MOUNTAINS...ESPECIALLY FOR THE MORNING HOURS...WITH ANOTHER 2
TO 5 INCHES. ACROSS PLAINS...BEST CHANCE FOR SNOW LOOKS TO BE
DURING THE MORNING WHEN THE DYNAMICS MOVES OVERHEAD. BUT DOWNSLOPE
WINDS WILL OFFSET THE SNOW POTENTIAL. SO ANY ACCUMULATION SHOULD
BE LESS THAN AN INCH....MAINLY ACROSS ZONE 38. SNOW CHANCES
DECREASE DURING THE AFTERNOON AS TROUGH MOVES INTO THE CENTRAL
PLAINS AND DOWNSLOPE INCREASES. LATEST MODELS STILL SHOW SOME
LIGHT ACCUMULATION ACROSS FAR NORTHEAST CORNER DURING THE
AFTERNOON. WILL KEEP CHANCE POPS THERE...BUT AMOUNTS WILL BE
LIGHT. AS FOR PRECIP TYPE...THICKESS PROGS SUGGEST ALL SNOW.
.LONG TERM...A CLOSED UPPER LEVEL LOW MOVING ACROSS THE NORTHERN
PLAINS WILL BRING A NORTHWEST FLOW ALOFT TO COLORADO TUESDAY NIGHT.
AS THIS SYSTEM EXITS THE REGION...MOUNTAIN SNOW WILL COME TO AN END
DURING THE NIGHT. A STABLE LAYER WILL FORM JUST ABOVE RIDGE TOP AND
CREATE A MOUNTAIN WAVE. WINDS AT RIDGE TOP WILL BE AROUND 50 KNOTS.
THE WAVE WILL ACCELERATE THESE WINDS DOWN THE FOOTHILLS RESUTLING IN
WIND GUSTS UP TO 80 MPH. WILL ISSUE A HIGH WIND WATCH FOR THE
FOOTHILLS AND AREAS AT THE BASE OF THE FOOTHILLS FOR TUESDAY NIGHT
AND EARLY WEDNESDAY MORNING.
THE WINDS WILL QUICKLY DIE OFF WEDNESDAY AS AN UPPER LEVEL RIDGE
QUICKLY PASSES OVER THE STATE. THIS WILL BRING MILD AND DRY
CONDITIONS TO NORTHEAST COLORADO.
NEXT STORM SYSTEM WILL DIG SOUTH ACROSS THE PACIFIC NORTHWEST AND
NORTHERN ROCKIES THURSDAY. THIS SYSTEM WILL LIKELY BRING ANOTHER
SHOT OF SNOW TO THE MOUNTAINS...THURSDAY AND FRIDAY. COLD FRONT WILL
PUSH SOUTH ACROSS NORTHEAST COLORADO THURSDAY. WINDS WILL BECOME
NORTHEAST BEHIND THE FRONT...PRODUCING AN UPSLOPE FLOW. WILL HAVE
SCATTERED POPS IN THE FORECAST THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. THE AREA WILL BE ON THE BACKSIDE OF THIS SYSTEM ON FRIDAY.
AIRMASS WILL BE SOMEWHAT UNSTABLE AND WILL KEEP LOW POPS FOR
NORTHEAST COLORADO IN THE FORECAST. FOR THE MOUNTAINS...THE SLIGHTLY
UNSTABLE FLOW OVER THE MOUNTAINS WILL PRODUCE SNOW SHOWERS...THUS
WILL HAVE HIGHER POPS OVER THE MOUNTAINS.
UPPER LEVEL RIDGE WILL BE ALONG THE WEST COAST SATURDAY. THIS WILL
PRODUCE A DRY AND MILD NORTHWEST FLOW OVER COLORADO. THE RIDGE WILL
SHIFT EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW
TEMPERATURES TO CLIMB ABOVE NORMAL SUNDAY AND MONDAY AS DRY
CONDITIONS CONTINUE. ON MONDAY...SOME 60S WILL BE POSSIBLE OVER
NORTHEAST COLORADO.
&&
.AVIATION..STRONG SOUTHERLY GRADIENT TO SLOWLY WEAKEN ACROSS
PLAINS THIS EVENING...WITH WINDS DECREASING AT DEN AND APA. WINDS
TO BECOME SOUTHWEST AT ALL THE AREA AIRPORTS BY 05Z AS SOUTHWEST
FLOW ALOFT INCREASES. MOISTURE TO GRADUALLY INCREASE THIS
EVENING...WITH CEILINGS OF 5000-6000 FEET AGL PREVAILING. CHANCE
FOR MVFR CEILINGS AT DEN AND APA AFTER 07Z IF LOW LEVEL MOISTURE
INCREASES FROM THE SOUTHEAST. SLIGHT CHANCE OF SNOW SHOWERS AFTER
06Z...POSSIBLY MIXED WITH RAIN. BEST CHANCE FOR SNOW TUESDAY
MORNING...AS TROUGH MOVES OVERHEAD. VFR CONDITIONS TO
PREVAIL...WITH POSSIBLE MVFR CONDITIONS WITH PASSING SNOW
SHOWERS. WINDS TO SHIFT TO THE NORTHWEST AFTER 16Z...CONTINUING
THROUGH THE DAY WITH SOME GUSTS TO 20 KTS POSSIBLE DURING THE
AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING
FOR COZ035-036-038-039.
&&
$$
SHORT TERM...D-L
LONG TERM....MEIER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MIAMI FL
237 PM EST MON FEB 27 2012
.DISCUSSION...
AS THE AFTERNOON PROGRESSES THE CHANCES FOR STRONG ISOLATED
THUNDERSTORMS IS SOLIDIFYING MORE BASED ON RADAR, SATELLITE AND
SURFACE OBSERVATIONS AROUND THE REGION. THE RUC RAPID REFRESH MODEL
INSISTS IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER
INTERIOR SECTIONS OF SOUTH FLORIDA THIS EVENING. THE RUC SHOWS THE
HIGHEST COVERAGE AFTER 4 PM EST. CURRENTLY, THE RADAR IS SHOWING
AN INCREASE IN SHOWERS SOUTHWEST OF THE LAKE. AT THE PRESENT TIME
THE ONLY LIGHTNING IN THE AREA IS ASSOCIATED WITH THE STORMS NORTH
OF THE LAKE OUTSIDE OF OUR CWA. ANOTHER IMPORTANT FACTOR IS THE
WEST COAST SEA BREEZE, WHICH IS CURRENTLY INLAND PASSED NAPLES, IS
FORECAST TO CONTINUE TO MOVE EAST AND COLLIDE WITH THE EAST AND
SOUTHEAST WINDS OVER THE EASTERN TWO THIRDS OF SOUTH FLORIDA.
TEMPERATURE MEASUREMENTS FROM DIFFERENT AIRPLANES ACROSS SOUTH
FLORIDA INDICATE THAT THE CAP BETWEEN 600 TO 700 MB IS STILL
PRESENT WITH SOME HINTS OF SOME CAP EROSION AS FORECAST BY THE RUC
MODEL.
WITH THESE CONDITIONS THERE IS A SLIGHT CHANCE OF THUNDERSTORMS LATE
THIS AFTERNOON INTO THIS EVENING OVER INTERIOR AREAS OF SOUTH
FLORIDA. THE PRIMARY IMPACTS FROM THE STORMS WILL BE LIGHTNING
STRIKES, HAIL, GUSTY WINDS, AND LOCALLY HEAVY RAINFALL. THE
STRONGEST STORMS WILL BE CAPABLE OF PRODUCING HAIL UP TO NICKEL
SIZE HAIL ESPECIALLY AROUND THE LAKE OKEECHOBEE AREA WHERE THE SEA
BREEZE AND LAKE BREEZES COLLIDE LATE THIS AFTERNOON INTO EARLY
THIS EVENING. THE MOST LIKELY TIME PERIOD FOR CONVECTION WILL BE
FROM 4 TO 8 PM SINCE WE STILL NEED MORE TIME FOR THE CAP TO ERODE
FURTHER.
CURRENT SATELLITE IMAGE SHOWS THAT THE CLOUD TOPS OF MOST OF THE
SHOWERS ARE BEGINNING TO BLOW TO THE EAST SOUTHEAST AT AROUND 20000
FEET, WHICH SHOWS THAT SOME OF THESE SHOWERS ARE BEGINNING TO BREAK
THROUGH THE CAP.
AFTER TODAY THE REST OF THE WEEK LOOKS DRY WITH THE EXCEPTION OF A
FEW SHOWERS STILL POSSIBLE FOR TUESDAY ESPECIALLY OVER THE EAST AND
CENTRAL SECTION OF SOUTH FLORIDA. THE NEXT TIME FOR SHOWERS IS
EXPECTED FOR SUNDAY AS A COLD FRONT IS FORECAST TO APPROACH SOUTH
FLORIDA. HOWEVER, THERE IS STILL CONSIDERABLE UNCERTAINTY ABOUT THE
STRENGTH AND TIMING OF THIS FRONT.
&&
.MARINE...
BENIGN MARINE CONDITIONS WILL ESTABLISH ON TUESDAY WITH THE REST OF
THE WEEK HAVING SEAS OF 2 TO 3 FEET.
&&
NO FIRE WEATHER CONCERNS ARE EXPECTED THIS WEEK. A FEW HOURS OF
RELATIVE HUMIDITY VALUES IN THE 40S ARE POSSIBLE THURSDAY AND FRIDAY
OVER GLADES AND HENDRY...OTHERWISE THE NEXT CHANCE FOR LOWER
RELATIVE HUMIDITY VALUES, BUT STILL ABOVE FIRE THRESHOLDS IS FOR
SUNDAY WITH A LOT OF UNCERTAINTY STILL WITH THIS FORECAST.
&&
.AVIATION...(ISSUED AT 1228 PM EST MON FEB 27 2012)
THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO DEVELOP AND
PUSH INLAND THIS AFTERNOON. THIS WILL KEEP THE EAST COAST TAF
SITES IN A SOUTHEAST WIND FLOW AT 15 TO 20 KNOTS...WHILE KAPF TAF
SITE BECOMES SOUTHWEST AT 5 TO 10 KNOTS AROUND 19Z THIS AFTERNOON.
THERE COULD BE A FEW SHOWERS AROUND THE TAF SITES OF
KPBI...KFLL...KFXE...AND KAPF THIS AFTERNOON AS THE SEA BREEZES
PUSHES INLAND. THE WINDS WILL THEN DECREASE TO LESS THAN 5 KNOTS
AT ALL OF THE TAF SITES THIS EVENING INTO TONIGHT AND CONTINUE TO
BE EASTERLY. THE WEATHER WILL ALSO REMAIN DRY TONIGHT AT ALL OF
THE TAF SITES. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR
CONDITIONS THIS AFTERNOON INTO TONIGHT AT ALL OF THE TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 83 69 82 / 20 10 10 10
FORT LAUDERDALE 73 83 72 82 / 20 10 10 10
MIAMI 72 84 71 83 / 20 10 10 10
NAPLES 66 86 65 85 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1228 PM EST MON FEB 27 2012
.AVIATION...
THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO DEVELOP AND
PUSH INLAND THIS AFTERNOON. THIS WILL KEEP THE EAST COAST TAF
SITES IN A SOUTHEAST WIND FLOW AT 15 TO 20 KNOTS...WHILE KAPF TAF
SITE BECOMES SOUTHWEST AT 5 TO 10 KNOTS AROUND 19Z THIS AFTERNOON.
THERE COULD BE A FEW SHOWERS AROUND THE TAF SITES OF
KPBI...KFLL...KFXE...AND KAPF THIS AFTERNOON AS THE SEA BREEZES
PUSHES INLAND.
THE WINDS WILL THEN DECREASE TO LESS THAN 5 KNOTS AT ALL OF THE
TAF SITES THIS EVENING INTO TONIGHT WHILE BE EASTERLY DIRECTION.
THE WEATHER WILL ALSO REMAIN DRY TONIGHT AT ALL OF THE TAF SITES.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS THIS
AFTERNOON INTO TONIGHT AT ALL OF THE TAF SITES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 947 AM EST MON FEB 27 2012/
UPDATE...
WE ADDED THE POSSIBILITY OF ISOLATED THUNDERSTORMS FOR THE CENTRAL
AND WESTERN SECTIONS OF SOUTH FLORIDA WITH THIS MORNING UPDATE.
THE MAIN PRECLUDING FACTOR FOR THE FORMATION OF ISOLATED
THUNDERSTORMS IS A MID LEVEL CAP AROUND 700 MB. HOWEVER, SOME OF
THE CAP COULD BE ERODED BY THE COMBINATION OF COLD ADVECTION WEST
OF THE TROUGH LINE AND WARM SURFACE TEMPERATURES IN THE MID 80S
COMBINED WITH BOUNDARY COLLISIONS. THE COMBINATION OF THE EAST FLOW WITH THE
FORMATION OF A WEST COAST SEA BREEZE AND LAKE BREEZE WILL ENHANCE
THE THUNDERSTORM POTENTIAL FOR GLADES, HENDRY, CENTRAL-WESTERN
COLLIER, AS WELL AS WESTERN PALM BEACH AND BROWARD COUNTIES.
RELATED TO THIS CHANGE POPS AND SKY WERE ALSO UPDATED. IF ALL THE
CORRECT INGREDIENTS COME TOGETHER SUCH AS SIGNIFICANT EROSION OF
THE CAP, ENHANCED BOUNDARY COLLISIONS, AND STRONGER COLD ADVECTION
ALOFT THAN FORECAST, AS THE MOST IMPORTANT FACTORS...SMALL HAIL
COULD OCCUR IN SOME SPOTS OF THE NORTHERN COUNTIES. HOWEVER, THE
CONFIDENCE FOR HAIL IS LOW AT THIS TIME FOR SOUTH FLORIDA.
&&
PREV DISCUSSION... /ISSUED 515 AM EST MON FEB 27 2012/
AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA
WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS
KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT
SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR
VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED
E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z.
SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE
9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025
BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS
BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF.
&&
PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/
DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH
AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS
MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS
A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS
NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH
MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE
REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW
AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM
BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER
MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS
DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE
FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST
STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT
FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN
A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING
THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA,
THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID
LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN
TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN
ACROSS FL THROUGH THE WEEK.
BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO
CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH
THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY
BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF
OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF
SHRA.
MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE
OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT
SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE
FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT
AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON.
FIRE WEATHER...NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 70 83 69 / 30 20 10 10
FORT LAUDERDALE 82 73 83 72 / 30 20 10 10
MIAMI 83 72 84 71 / 20 20 10 10
NAPLES 85 66 86 65 / 30 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
1247 PM EST MON FEB 27 2012
.UPDATE...
/ISSUED AT 1004 AM EST MON FEB 27 2012/
BEST MOISTURE AND LIFT EXITING CENTRAL GA WITH PRECIP CHANCES
DIMINISHING OR HAVE ENDED. STILL GOOD MOISTURE IN PLACE ACROSS
CENTRAL GA AND YOU CAN NOT COMPLETELY RULE OUT SPRINKLES...BRIEF
LIGHT RAIN OR DRIZZLE FOR SOME AREAS. FORECAST HIGH TEMPERATURES
RUNNING NEAR TO SLIGHTLY ABOVE NORMAL. BDL
&&
.PREV DISCUSSION... /ISSUED 639 AM EST MON FEB 27 2012/
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS
MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK
SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL
AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS
SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE
MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW
SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA.
ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE
GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR
INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE
NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE...
A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT
LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE
NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED
COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW
GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL
AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA
BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH
THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY
EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE
300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK
SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL
NORMS THROUGH THE SHORT TERM.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH
AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS
N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW
PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE
INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS
WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW
CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE
SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY
WITH THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT
JUST TOO FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM
WILL BE. TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH
DAY 7.
&&
.AVIATION...
18Z UPDATE...
VIS SATL AND AREA OBS TRENDING TOWARD VFR BY 19-20Z THIS AFTN IF NOT
SOONER. LATEST SFC ANALYSIS SHOWS A COLD FRONT SLOWLY PUSHING ACROSS
WEST TN. THE SFC RIDGE TO THE EAST WILL BATTLE WITH WEAK SFC TROUGH
MOVING IN FROM THE NW TO RESULT IN LIGHT 3-4KT WINDS VARYING FROM
NNW TO NNE AT TIMES THROUGH THE AFTERNOON. MODELS AGREE ON FRONT
PUSHING ACROSS ATL AROUND 03Z THIS EVENING... SO WIND DIRECTIONS
SHOULD SETTLE AT 4-5KTS NNE BY THEN. NO -RA OR LOW CIGS EXPECTED
WITH THE FRONT AT ATL FOR NOW... BUT BEHIND THE FRONT... WILL HAVE
TO WATCH THE POTENTIAL FOR MVFR CIGS CLOSELY. MID LEVEL CIGS MOVE
INTO THE AREA BY 19-21Z TUE AS MOIST SW MID LEVEL FLOW OVERRUNS AN
EASTERLY SFC FLOW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON VFR TONIGHT.
HIGH ON REMAINING ELEMENTS.
/39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 44 71 53 / 5 0 20 30
ATLANTA 64 50 71 57 / 0 0 20 30
BLAIRSVILLE 63 40 66 50 / 0 0 20 50
CARTERSVILLE 64 42 71 53 / 0 0 20 40
COLUMBUS 66 50 75 58 / 20 5 10 20
GAINESVILLE 63 47 67 54 / 0 0 20 40
MACON 65 47 73 56 / 20 5 10 10
ROME 66 42 72 54 / 0 0 20 50
PEACHTREE CITY 64 42 71 55 / 5 0 20 30
VIDALIA 65 52 73 57 / 30 5 10 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
332 PM EST MON FEB 27 2012
.SYNOPSIS...
HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA
TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY.
ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL
GREAT LAKES WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN
RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE
NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS
QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY
ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH
THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER
WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING
THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS
SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET
TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH.
ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS
DROPPING BACK TO THE LOWER TO MID 20S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE
EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE
TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE
PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO
OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z
ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR
PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA
THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE
ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT
THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT
THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS
WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL
SWITCH OVER TO RAIN.
MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER
ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS
AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT
DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO
REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE
TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET
NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER
THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED
ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE.
LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF
THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE
NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS
NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN
WILL DRY OUT THE AREA THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE
MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY
EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS
INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE
INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER
INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE
SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO
PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING
STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY
SNOW SHOWERS THAT ARE IN THE AREA.
SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN
COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A
COUPLE DEGREES OF 40.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
GUSTY WINDS WILL CONTINUE TO MOVE ACROSS NORTHERN OHIO THROUGH THE
AFTERNOON. EASTERN AREAS WILL SEE THESE STRONGER WINDS ARRIVE AS
THE MIDDLE LEVEL CLOUD COVER GIVES WAY TO CLEAR SKIES. IT APPEARS
AT THIS TIME THAT WESTERLY WINDS WILL GUST IN THE 25 TO NEAR 40
KNOT RANGE. THE STRONGEST GUSTS WILL GENERALLY BE NEAR AND NORTH OF
A LINE FROM FINDLAY TO ERIE.
THE WINDS WILL DECREASE SHORTLY AFTER SUNSET WITH VFR CONDITIONS
ANTICIPATED THROUGH THE NIGHT. WE WILL HAVE TO MONITOR NE OH INTO
NW PA FOR SOME LOWER LEVEL VFR CEILINGS FOR A BRIEF PERIOD AFTER
MIDNIGHT. OTHERWISE EXPECT TO SEE SOME MIDDLE AND HIGH LEVEL CLOUD
COVER RETURN FROM WEST TO EAST TUESDAY MORNING INTO THE EARLY
AFTERNOON.
OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND
CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR MAY RETURN BY FRIDAY
NIGHT INTO SATURDAY.
&&
.MARINE...
A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE
FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING
GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW
GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG.
SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND
WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE
BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE.
EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW
PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR
THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO
THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY
CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST
END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE
WEST.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR OHZ012>014-
021>023-031>033-089.
WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ003-006>011-
017>020-027>030.
PA...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR PAZ001>003.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR LEZ144>149.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142-
143.
&&
$$
SYNOPSIS...ABE
NEAR TERM...ABE
SHORT TERM...ABE
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...KEC