Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 02/25/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
215 PM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 214 PM MST THU FEB 23 2012
WEB CAMS INDICATE THE SUN HAS BEGUN TO POKE THROUGH OVER THE
CENTRAL MOUNTAINS. OBSERVATIONS ALSO VERIFY THAT SNOW AND WIND ARE
DIMINISHING THERE. THEREFORE LET THE WINTER HIGHLIGHTS EXPIRE.
WHILE SOME SNOW AND BLOWING SNOW WILL CONTINUE OVER THESE AND THE
OTHER COLORADO MOUNTAINS...CONDITIONS HAVE MARKEDLY IMPROVED.
HAVE ALSO CANCELED THE WIND ADVISORY FOR ALL THE CO ZONE 22...THE
DURANGO AREA. WHILE BREEZY CONDITIONS PERSIST OVER MUCH OF THE
FORECAST AREA...WIND SPEEDS HAVE DECREASED AND ARE WELL BELOW
ADVISORY CRITERIA MOST LOCATIONS. THE EXCEPTION TO THIS IS OVER
CO ZONE 22. GUSTS AT THE LA PLATA COUNTY AIRPORT CONTINUE TO PUSH
AGAINST THE CRITERIA OF 45 MPH...SO WILL LET THE ADVISORY RIDE.
UPDATE ISSUED AT 1053 AM MST THU FEB 23 2012
WINDS HAVE DIMINISHED THIS MORNING ACROSS AREAS BEHIND THE FRONT.
WHILE CONDITIONS WILL REMAIN BREEZY...AND WITH WINDS EVEN
INCREASING SOMEWHAT BY MIDDAY...THEY ARE NOT EXPECTED TO BE AS
STRONG AS WHAT WAS ASSOCIATED WITH THE FRONT. THEREFORE THE WIND
ADVISORY WILL BE DROPPED FOR THE CENTRAL VALLEYS AND NORTHWARD.
WIND ADVISORIES WILL CONTINUE FOR THE SOUTHERN VALLEYS.
IN ADDITION...SNOW HAS WOUND DOWN OVER MANY OF THE MOUNTAIN AREAS...
AND THE STEAMBOAT SPRINGS AREA. WHILE SNOW SHOWERS WILL CONTINUE
THROUGH THIS AFTERNOON...LITTLE TO NO ADDITIONAL ACCUMULATIONS ARE
EXPECTED. THEREFORE WILL LET THE WINTER STORM WARNING FOR THE
NORTHERN MOUNTAINS AND THE STEAMBOAT AREA EXPIRE AT 11 AM...AND
WILL CANCEL THE SNOW ADVISORIES FOR THE COLORADO TAVAPUTS AND THE
GRAND MESA WHERE SUN HAS BROKEN THROUGH. WILL LET THE HIGHLIGHTS
RIDE FOR THE CENTRAL DIVIDE FOR NOW...CO ZONES 10/12. SNOW CONTINUES
OVER MUCH OF THOSE ZONES...AND WINDS STILL QUITE STRONG. THE
COMBINATION WILL KEEP CONDITIONS HAZARDOUS FOR AWHILE YET.
UPDATE ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUIDANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1053 AM MST THU FEB 23 2012
STRONG GUSTY WINDS HAVE DEVELOPED OVER THE SOUTHERN THIRD OF THE
FORECAST AREA...WHILE DECREASING SOMEWHAT OVER THE NORTH...AS A COLD
FRONT PUSHES SOUTHWARD. SNOW HAS ALSO DEVELOPED OVER THE SOUTHERN
MOUNTAINS AND IN SOME HIGHER VALLEY AREAS. WHILE SNOW HAS DIMINISHED
OVER THE NORTH...SNOW SHOWERS WILL CONTINUE THROUGH THE DAY OVER ALL
MOUNTAIN AREAS. THEREFORE AREAS OF MVFR/IFR CIGS/VIS...AND TURBULENT
MIXING WILL PERSIST THROUGH THE DAY OVER THE MOUNTAIN AREAS. LOW
LEVEL WIND SHEAR WILL ALSO BE POSSIBLE IN SOME VALLEY AREAS AS LOCAL
WINDS DIMINISH NEAR THE SURFACE. GRADUAL IMPROVEMENT IS EXPECTED
LATE THIS AFTERNOON THROUGH THIS EVENING. OTHERWISE VFR CONDITIONS
EXPECTED AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND EASTERN
UTAH...WITH VFR EVERYWHERE BY LATE THIS EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ022.
UT...NONE.
&&
$$
UPDATE...EH
SHORT TERM...MC
LONG TERM....PF
AVIATION...EH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1053 AM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 1053 AM MST THU FEB 23 2012
WINDS HAVE DIMINISHED THIS MORNING ACROSS AREAS BEHIND THE FRONT.
WHILE CONDITIONS WILL REMAIN BREEZY...AND WITH WINDS EVEN
INCREASING SOMEWHAT BY MIDDAY...THEY ARE NOT EXPECTED TO BE AS
STRONG AS WHAT WAS ASSOCIATED WITH THE FRONT. THEREFORE THE WIND
ADVISORY WILL BE DROPPED FOR THE CENTRAL VALLEYS AND NORTHWARD.
WIND ADVISORIES WILL CONTINUE FOR THE SOUTHERN VALLEYS.
IN ADDITION...SNOW HAS WOUND DOWN OVER MANY OF THE MOUNTAIN AREAS...
AND THE STEAMBOAT SPRINGS AREA. WHILE SNOW SHOWERS WILL CONTINUE
THROUGH THIS AFTERNOON...LITTLE TO NO ADDITIONAL ACCUMULATIONS ARE
EXPECTED. THEREFORE WILL LET THE WINTER STORM WARNING FOR THE
NORTHERN MOUNTAINS AND THE STEAMBOAT AREA EXPIRE AT 11 AM...AND
WILL CANCEL THE SNOW ADVISORIES FOR THE COLORADO TAVAPUTS AND THE
GRAND MESA WHERE SUN HAS BROKEN THROUGH. WILL LET THE HIGHLIGHTS
RIDE FOR THE CENTRAL DIVIDE FOR NOW...CO ZONES 10/12. SNOW CONTINUES
OVER MUCH OF THOSE ZONES...AND WINDS STILL QUITE STRONG. THE
COMBINATION WILL KEEP CONDITIONS HAZARDOUS FOR AWHILE YET.
UPDATE ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUIDANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1053 AM MST THU FEB 23 2012
STRONG GUSTY WINDS HAVE DEVELOPED OVER THE SOUTHERN THIRD OF THE
FORECAST AREA...WHILE DECREASING SOMEWHAT OVER THE NORTH...AS A COLD
FRONT PUSHES SOUTHWARD. SNOW HAS ALSO DEVELOPED OVER THE SOUTHERN
MOUNTAINS AND IN SOME HIGHER VALLEY AREAS. WHILE SNOW HAS DIMINISHED
OVER THE NORTH...SNOW SHOWERS WILL CONTINUE THROUGH THE DAY OVER ALL
MOUNTAIN AREAS. THEREFORE AREAS OF MVFR/IFR CIGS/VIS...AND TURBULENT
MIXING WILL PERSIST THROUGH THE DAY OVER THE MOUNTAIN AREAS. LOW
LEVEL WIND SHEAR WILL ALSO BE POSSIBLE IN SOME VALLEY AREAS AS LOCAL
WINDS DIMINISH NEAR THE SURFACE. GRADUAL IMPROVEMENT IS EXPECTED
LATE THIS AFTERNOON THROUGH THIS EVENING. OTHERWISE VFR CONDITIONS
EXPECTED AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND EASTERN
UTAH...WITH VFR EVERYWHERE BY LATE THIS EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR COZ012.
WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ020>022.
WINTER STORM WARNING UNTIL 2 PM MST THIS AFTERNOON FOR
COZ010.
UT...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ022-029.
&&
$$
UPDATE...EH
SHORT TERM...MC
LONG TERM....PF
AVIATION...EH
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
652 AM MST THU FEB 23 2012
.UPDATE...
INSTABILITY IS OVERWHELMING DOWNSLOPE OFF THE PALMER DIVIDE...SO
HAVE UPDATED THE FORECAST TO INCREASE POPS A TOUCH MORE ACROSS
SOUTHERN EL PASO...PUEBLO AND THE WET MOUNTAINS. ALSO SEEING SNOW
EXPANDING ACROSS FREMONT COUNTY. EXPECT THIS BAND TO CONTINUE
SHIFTING SOUTHWARD...WITH SNOW DIMINISHING BY LATE MORNING ACROSS
EL PASO COUNTY. ALREADY STARTING TO SEE RADAR ECHOES DECREASING ACROSS
NORTHERN EL PASO COUNTY...THOUGH SUSPECT THAT INSTABILITY WILL
KEEP AT LEAST INTERMITTENT SNOW GOING OVER THIS AREA THROUGH THE
11 AM DURATION OF THE WINTER WEATHER ADVISORY. -KT
&&
.PREV DISCUSSION... /ISSUED 459 AM MST THU FEB 23 2012/
UPDATE...
HEAVY SNOW OVER THE PALMER DIVIDE...EVIDENT IN WEB CAMS...IS
STACKING UP QUICKER THAN EXPECTED THANKS TO THE AVAILABLE
INSTABILITY. MODELS STILL INDICATE BRUNT OF HEAVIER SNOW SHOULD BE
DONE BY 10 AM...BUT WITH SNOW COVERED ROADS WITH THE MORNING
COMMUTE HAVE OPTED TO PUT OUT A WINTER WEATHER ADVISORY FOR TELLER
AND NORTHERN EL PASO COUNTY THROUGH 11 AM. SNOWFALL AMOUNTS OF 2
TO 5 INCHES LOOK ACHIEVABLE. FORECAST UPDATE COMING OUT SHORTLY.
-KT
PREV DISCUSSION... /ISSUED 426 AM MST THU FEB 23 2012/
SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
LONG TERM...
(FRIDAY THROUGH THURSDAY)
.MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. 44
AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ081-
082-084.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
634 AM MST THU FEB 23 2012
.UPDATE...
ISSUED AT 625 AM MST THU FEB 23 2012
COLD FRONT PROGRESSING SOUTH THIS MORNING AND CURRENTLY BETWEEN
THE I70 CORRIDOR AND A LINE FROM MONTROSE TO THE GUNNISON VALLEY.
FARTHER EAST WITHIN THE BAROCLINIC ZONE...THE MOUNTAINS GETTING
POUNDED WITH SNOW AND WIND AND I70 IS CURRENTLY SHUT DOWN EAST OF
VAIL. HRRR DATA SHOWS PLENTY OF WIND PROGRESSING SOUTH WITH THE
FRONT AND HAVE ISSUED WIND ADVISORY FOR THE VALLEYS OF SOUTHEAST
UTAH AND SOUTHWEST COLORADO. IN THE MOUNTAINS...WINTER WEATHER
ADVISORY ADDRESSES THE COMBINATION OF SNOW AND WIND. A BURST OF
HEAVY SNOW AND WIND OCCURS WITH THE FRONT PASSAGE...BUT THE FRONT
IS MOVING FAIRLY QUICKLY WITH DRY ADVECTION OCCURRING BEHIND THE
FRONT. DO NOT EXPECT MUCH SNOW ACCUMULATION TO OCCUR THIS
AFTERNOON AS THE AIR MASS WILL BE VERY DRY. THERE IS A 2-3 HOUR
PERIOD OF NASTY CONDITIONS...AS EVIDENT ON THE WEB CAMS OVER VAIL
PASS AND EXPECT SIMILAR CONDITIONS TO OCCUR OVER MONARCH PASS.
THE SAN JUAN MOUNTAINS MAY NEED A WINTER WEATHER ADVISORY AS
WELL...BUT DYNAMICAL SUPPORT WILL BE MOVING DOWNSTREAM AS THE
FRONT MOVES INTO SW COLORADO. WILL CONTINUE TO MONITOR THIS SITUATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS WORKING ITS WAY SOUTHWARD THROUGH NORTHWESTERN
COLORADO AT 09Z...EXPECT IT WILL WORK ITS WAY TO GJT AROUND 12Z.
FRONT IS PRETTY ENERGETIC WITH GOOD Q CONVERGENCE AND FRONTOGENETIC
FORCING. HOWEVER THE DEEPEST MOISTURE AND BEST CHANCES OF PCPN
WILL BE OVER THE NRN AND PORTIONS OF CNTRL MTNS WHERE WINTER
WEATHER HIGHLIGHTS ARE CURRENTLY IN PLACE. ITS STILL RAINING IN
CAG BEHIND THE FRONT BUT EXPECT THEY WILL TURN TO SNOW SHORTLY...WHILE
AT THE HIGHER ELEVATIONS A GOOD BURST OF HEAVY SNOW WILL PRECEDE
AND ACCOMPANY THE FRONT. WINDS STILL REMAIN A FACTOR WITH GUSTS UP
70KTS OVER SOME OF THE HIGHER MTNS (MT ABRAMS). AT THIS TIME THE
CURRENT HIGHLIGHTS ARE IN GOOD SHAPE WITH RESPECT TO AREAL
COVERAGE AND TIMING/INTENSITY OF SNOWFALL. ALSO THE WIND ADVISORY
OVER THE NW PLATEAU LOOKS IN GOOD SHAPE WITH SEVERAL RAWS SITES
INDICATING GUSTS OF 45 MPH OR HIGHER.
EXPECT THE INTENSITY OF SNOWFALL TO TAPER OFF BEHIND THE FRONT AS
MUCH DRIER AND COOLER AIR MOVES IN FROM THE NORTH. AS FOR THE LOWER
WESTERN VALLEYS OF COLORADO AND MOST ALL OF EASTERN UT...THIS
LOOKS LIKE MORE A WIND STORM THAN PCPN PRODUCER.
A FEW SHOWERS WILL LINGER OVER THE NW FACING SLOPES OF THE NRN AND
EAST CENTRAL MTNS TONIGHT...DECREASING AFTER MIDNIGHT. ELSEWHERE
DRY CONDITIONS WITH MUCH COOLER OVERNIGHT LOWS ARE EXPECTED.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 217 AM MST THU FEB 23 2012
FRIDAY...PROGRESSIVE RIDGE WILL MOVE ACROSS THE INTERMOUNTAIN WEST
ON FRIDAY AND WILL BRING DRY WEATHER. STRONG SURFACE BASED
INVERSIONS WILL KEEP VALLEYS COOL.
RIDGE CONTINUES DOWNSTREAM ON SATURDAY AND ALLOWS A STRONG PACIFIC
TROUGH TO MOVE ACROSS THE NWRN CONUS. THE 00Z MODEL SUITE SUPPORTS
YESTERDAYS 12Z TREND THAT THE DIGGING TROUGH WILL NOT BE AS
PRONOUNCED. DEEP SURFACE CYCLONE TRACKS ACROSS THE NRN
PLAINS...BUT THIS CYCLONE WILL COVER PLENTY OF TERRITORY. PRESSURE
GRADIENTS WILL TIGHTEN SIGNIFICANTLY SATURDAY AFTERNOON ONCE THE
SURFACE TROUGH DEVELOPS IN THE PLAINS. THE GREATEST IMPACT FROM
THIS PACIFIC WAVE MAY VERY WELL BE WIND AS THIS SYSTEM HARDLY
ENTRAINS ANY MOISTURE. LATEST GUDIANCE SHOW DEW POINTS CRASHING
INTO THE SINGLE DIGITS AND TEENS IN THE AFTERNOON ONCE THE SURFACE
BASED INVERSIONS MIX OUT. THE BEST DYNAMICAL LIFT...COINCIDING
WITH STRONG MID LEVEL COLD ADVECTION...OCCURS SATURDAY EVENING
WITH THE BEST CHANCE OF SNOW OCCURRING OVER THE NRN MOUNTAINS.
MODERATE TO HEAVY SNOW ACROSS THE PARK RANGE IS POSSIBLE FOR 3-4
HOURS AS THE COLD POCKET SWEEPS ACROSS NW COLORADO. OTHERWISE THIS
SYSTEM IS MOISTURE STARVED AND DIABATIC COOLING WILL HAVE A TOUGH
TIME MOISTENING THE AIR MASS WITH PRECIPITABLE WATER CONTENT OF
ONLY A QUARTER INCH.
SUNDAY THROUGH TUESDAY...A SECONDARY SHORT WAVE DIGS INTO THE GREAT
BASIN ON SUNDAY NIGHT. THIS WILL BE FOLLOWED BY ANOTHER DIGGING
WAVE FROM ALBERTA ON TUESDAY THAT REINFORCES THE COLDER AIR MASS
ACROSS THE REGION. NEITHER OF THESE FEATURES WILL HAVE MUCH
MOISTURE TO WORK WITH...BUT DOES KEEP THE AIR MASS COOL AND
UNSETTLED WITH A CHANCE OF MOUNTAIN SNOW SHOWERS.
APPEARS THAT NEXT WEDNESDAY WILL BE DRY AS TRANSITORY RIDGE MOVES
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z EARLY FRIDAY MORNING)
ISSUED AT 217 AM MST THU FEB 23 2012
A STRONG COLD FRONT IS PUSHING SOUTHWARD THROUGH NORTHWEST
COLORADO AT 12Z...RESULTING IN CONTINUED GUSTY WINDS AND AN
INCREASE IN SNOWFALL FOR THE NORTHERN MOUNTAINS AND VALLEYS. WINDS
GUSTING TO NEAR 50 MPH IN THE VALLEYS...WITH MTN TOP WINDS
APPROACHING 65 MPH CAN BE EXPECTED THROUGH 15Z. PREVAILING WIND
DIRECTION WILL BE SHIFTING FROM THE WEST TO NORTHWEST AS THE FRONT
PASSES. EXPECT CIGS AND VSBYS TO DROP INTO IFR THRESHOLDS FOR
NORTHERN SITES SUCH AS KCAG...KHDN AND KSBS. KEGE AND KASE WILL
ALSO SEE A DROP IN CIGS AFTER 12Z AS THE FRONT PUSHES THROUGH THE
CENTRAL ZONES. GRADUAL IMPROVEMENT IS EXPECTED LATER THIS AFTERNOON
AT THE ABOVE MENTIONED SITES...OTHERWISE VFR CONDITIONS EXPECTED
TO PERSIST AT THE LOWER VALLEY SITES OF WESTERN COLORADO AND
EASTERN UTAH THROUGH THIS FORECAST PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ006>008-011-014-
020>022.
WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR COZ003-
009-012.
WINTER STORM WARNING UNTIL 2 PM MST THIS AFTERNOON FOR COZ010.
WINTER STORM WARNING UNTIL 11 AM MST THIS MORNING FOR COZ004-005-
013.
WIND ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ001-002.
UT...WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR UTZ022-027-029.
&&
$$
UPDATE...PF
SHORT TERM...MC
LONG TERM....PF
AVIATION...MC
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
459 AM MST THU FEB 23 2012
.UPDATE...
HEAVY SNOW OVER THE PALMER DIVIDE...EVIDENT IN WEB CAMS...IS
STACKING UP QUICKER THAN EXPECTED THANKS TO THE AVAILABLE
INSTABILITY. MODELS STILL INDICATE BRUNT OF HEAVIER SNOW SHOULD BE
DONE BY 10 AM...BUT WITH SNOW COVERED ROADS WITH THE MORNING
COMMUTE HAVE OPTED TO PUT OUT A WINTER WEATHER ADVISORY FOR TELLER
AND NORTHERN EL PASO COUNTY THROUGH 11 AM. SNOWFALL AMOUNTS OF 2
TO 5 INCHES LOOK ACHIEVABLE. FORECAST UPDATE COMING OUT SHORTLY.
-KT
&&
.PREV DISCUSSION... /ISSUED 426 AM MST THU FEB 23 2012/
SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
LONG TERM...
(FRIDAY THROUGH THURSDAY)
..MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. 44
AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ081-
082-084.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS PUEBLO CO
426 AM MST THU FEB 23 2012
.SHORT TERM...
(TODAY AND TONIGHT)
UPPER JET MOVING IN FROM THE NORTHWEST HAS JUST ABOUT ENDED HIGH
WINDS THREAT FOR MOST AREAS AS WINDS ALOFT QUICKLY ATTAIN MORE
FORWARD SHEAR. HAVE CANCELLED THE HIGH WIND WARNINGS FOR THE PIKES
PEAK REGION AND THE SAWATCH AND MOSQUITO RANGES...AND WILL BE TAKING
DOWN SOUTHERN AREAS WITHIN THE HOUR.
MEANWHILE...COLD FRONT HAS ALREADY DROPPED INTO EL PASO COUNTY WITH
NORTHERLY GUSTS TO 45 MPH OUT AT KABH. NICE BAND OF SNOW IN AREA
RADARS SINKING SOUTHWARD INTO NRN EL PASO COUNTY COINCIDENT WITH
UPPER JET FORCING AND INSTABILITY. HAVE EVEN HAD SOME LIGHTNING
STRIKES ACROSS NORTHERN COLORADO...INDICATIVE OF THE INSTABILITY
PRESENT WITH THIS SYSTEM. CENTRAL MOUNTAINS HAVE ALSO BEEN GETTING
IN ON THE ACTION...AND HAVE ALREADY HOISTED A WINTER WX ADVISORY FOR
THIS REGION DUE TO A COMBINATION OF THE MODERATE-HEAVY SNOW AND
BLOWING SNOW THROUGH THE MORNING. EXPECT THESE AREAS WILL SEE
SNOWFALL TOTALS IN THE 3-6 INCH RANGE ACROSS THE SAWATCH AND
MOSQUITO RANGES WHICH MAY BE A LITTLE SHY OF HITTING WIDESPREAD
ADVISORY AMOUNTS...BUT WITH THE BLOWING SNOW EXPECT THERE WILL BE
IMPACTS TO TRAVEL OVER THE MOUNTAIN PASSES. A LITTLE TRICKIER
FORECAST FOR TELLER AND EL PASO AS FAR AS SNOWFALL AMOUNTS GO.
SUSPECT THAT SOME AREAS WILL PICK UP A QUICK 1 TO 2
INCHES...PARTICULARLY ACROSS NORTHERN PORTIONS OF THE AREA. ROAD
SURFACES MAY QUICKLY BECOME SNOWPACKED WITH WIND RESULTING IN POOR
VISIBILITIES IN BLOWING SNOW ALONG I-25 OVER MONUMENT AND ACROSS
HIGHWAY 24 EAST OF KCOS DURING THE MORNING COMMUTE. WILL CONTINUE
TO MONITOR THIS REGION CLOSELY...BUT THINK EVENT SHOULD BE FAIRLY
BRIEF WITH SNOW WINDING DOWN BY 10 AM. NEXT QUESTION WILL BE HOW
FAR SOUTH THIS BAND WILL TRAVERSE. HIGH RES HRRR/AND RUC13 DIMINISH
THIS BAND AS IT MOVES SOUTHWARD INTO PUEBLO COUNTY AS IT BATTLES
STRONG DOWNSLOPE OFF THE PALMER DIVIDE. HOWEVER...THERE IS A 3 HOUR
WINDOW OF SOME FAIRLY STEEP LAPSE RATES ALOFT...SO ITS POSSIBLE THAT
THE EASTERN SLOPES OF THE WETS AS WELL AS PUEBLO COUNTY COULD SEE A
PERIOD OF RAIN/SNOW SHOWERS THIS MORNING AS THIS BAND MOVES
THROUGH. ACCUMULATIONS OF A COUPLE INCHES NOT OUT OF THE QUESTION
FOR THE WETS...WITH LITTLE TO NO ACCUMULATION EXPECTED FOR KPUB
EASTWARD AS TEMPERATURES WILL LIKELY REMAIN ABOVE FREEZING. HAVE
INCREASED POPS FOR THESE AREAS. MAJORITY OF THE SOUTHEAST PLAINS WILL
REMAIN DRY...THOUGH SOME ISOLATED RAIN/SNOW SHOWERS THIS MORNING NOT
OUT OF THE QUESTION. MAIN STORY FOR EASTERN AREAS WILL BE
WINDS...AS NORTH WINDS BEHIND THE FRONT QUICKLY INCREASE TO 25 TO 35
MPH WITH GUSTS TO NEAR 50 MPH. SHORT RANGE HIGH RES MODELS ALL KEEP
THE WINDS BELOW HIGH WIND CRITERIA...SO NO HIGH WIND HIGHLIGHTS ARE
ANTICIPATED FOR THE PLAINS AT THIS TIME.
WILL MAINTAIN SOME ISOLATED TO SCATTERED POPS IN AND NEAR THE
MOUNTAINS THIS EVENING WITH SOME LINGERING MOISTURE/INSTABILITY
AROUND. HOWEVER...CLEARING SKIES AND COLD AIR OVER THE REGION WILL
PROVIDE A FAVORABLE SET UP FOR A COLD NIGHT...WITH LOWS DROPPING
INTO THE TEENS AND 20S ACROSS THE LOWER ELEVATIONS...WITH SINGLE
DIGITS ABOVE AND BELOW ZERO ACROSS THE MOUNTAIN AREAS. -KT
.LONG TERM...
(FRIDAY THROUGH THURSDAY)
...MORE WILD TEMPERATURE SWINGS AHEAD...
MAIN WX OF NOTE IN THE EXTENDED WILL BE THE IMPACT OF SEVERAL COLD
FRONTS...THE FIRST EARLY SUN...THEN EVEN STRONGER ADVANCES OF
MODIFIED ARCTIC AIR ON TUE AND NEXT THU. AT THIS TIME...IT LOOKS
LIKE MOST OF THE PRECIP WILL REMAIN N WITH THESE SYSTEMS...WITH
SOME POTENTIAL FOR UPSLOPE OR OVERRUNNING PRECIP OVR THE ERN MTS AND
PLAINS WITH EACH FRONT.
FRIDAY LOOK LIKE A BIT OF A TRANSITION DAY...WITH TEMPS REMAINING ON
THE COOL SIDE AND POPS ESSENTIALLY NIL THU FRI NIGHT. WINDS SHOULD
TAKE A BIT OF A BREAK AS THE UPPER RIDGE BUILDS EWD DURING THE DAY.
SAT...COULD BE ANOTHER WARM AND WINDY DAY. CORE OF A 90KT MID LEVEL
SPEED MAX WILL BE OVR THE SERN PORTION OF CO SAT AFTERNOON. LOOKS
LIKE WINDS WILL PROBABLY STAY CONFINED TO ELEVATIONS ABOVE ABOUT 10K
FEET...BUT THE ERN SLOPES FROM GREENHORN TO LA VETA PASS AND SWD TO
THE SPANISH PEAKS REGION WILL HAVE TO BE WATCHED FOR POTENTIALLY
STRONG WINDS BOTH SAT AND SAT NIGHT. OVR THE PLAINS...THE DOWNSLOPE
WINDS WILL AGAIN BOOST TEMPS TO AROUND 60 DEG OR HIGHER SAT
AFTERNOON. SHOULD SEE SHSN MOVE INTO THE CENTRAL MTS/CONTDVD BY LATE
SAT AFTERNOON...AND SEVERAL INCHES MAY ACCUMULATE N OF KMYP BY SUN
MORNING.
NEXT COLD FRONT SWEEPS THRU SE CO SUN MORNING. THE TREND OVR THE
PAST COUPLE OF DAYS HAS BEE4N TO KEEP MOST OF THE QG LIFT WITH THIS
SYSTEM TO OUR N...SO MAIN IMPACT LOOKS TO BE ANOTHER COLD DAY ON
SUN...WITH TEMPS IN THE 40S AT BEST. THIS FRONT IS QUICKLY FOLLOWED
BY A SECOND FRONT LATE MON OR TUE...ALTHOUGH TIMING DIFFERENCES
APPEAR BY THEN BETWEEN THE GFS AND ECMWF. GENERALLY WENT WITH THE GFS
SOLUTION...WHICH BRINGS H7 AIR OF MINUS 15 OR LOWER BY SUN...WHICH
WOULD MEAN TEMPS STRUGGLING TO GET OUT OF THE 30S OVR THE
PLAINS...AND MTN TEMPS IN THE TEENS AND 20S. THIS SYSTEM LOOKS A BIT
MORE AMPLIFIED THAN THE ONE OVR THE WEEKEND...SO COULD SEE A BETTER
SHOT OF WIDESPREAD PRECIP FOR OUR AREA. WITH TIMING DIFFERENCES
BEGINNING TO AMPLIFY LATE IN THE PERIOD...CONFIDENCE IN SPECIFIC WX
FOR LATER NEXT WEEK IS LOW...BUT IT APPEARS LIKELY THAT ANOTHER
SURGE IN COLD AIR WILL ARRIVE LATE IN THE WEEK...KEEPING US IN AN
UNSETTLED AND COLD PATTERN...MARCH COMING IN LIKE A LION. ROSE
&&
.AVIATION...
MVFR CIGS WILL SPREAD INTO KCOS THIS MORNING WITH -SHRA/SN EXPECTED
THROUGH 16Z. UNDER THE MORE INTENSE SNOW BANDS...COULD SEE SOME
BRIEF IFR CONDITIONS WITH ACCUMULATIONS OF 1 TO 2 INCHES POSSIBLE. NORTH
WINDS IN THE 25-40 KT RANGE WILL AFFECT KCOS AND KPUB THROUGH THE
MORNING. A BRIEF SHOT OF -SHRA/SN MAY AFFECT THE KPUB TAF SITE THIS
MORNING...BUT EXPECT THE SNOW BAND TO DIMINISH AS IT DROPS SOUTH OF
THE PALMER DIVIDE. WILL PUT A WINDOW OF MVFR-VFR CIGS AT KPUB WITH
VCSH DURING THE MID-LATE MORNING. KALS WILL SEE VFR CONDITIONS WITH
BREEZY NORTH WINDS. VFR CONDITIONS EXPECTED TONIGHT WITH LIGHTER
WINDS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ058-060.
HIGH WIND WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR COZ072-
073-075-077>080.
&&
$$
31/44
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
425 AM EST THU Feb 23 2012
.SYNOPSIS...
08Z water vapor and H4 RUC analysis shows a northern stream pattern
consisting of broad troughing from the inter-mountain west to the
eastern seaboard. A series of disturbances diving southeastward
along the western periphery of this trough will act to amplify the
flow into the central and eastern CONUS over the next 24 hours to 36
hours. As was finally agreed upon by the global guidance last night,
a cutoff low spinning over the Mexican Baja region is not being
picked up by this amplifying trough, and will not move east to
influence our regions weather until the second half of the upcoming
weekend. More on this in the long term discussion below. A fast
southern stream flow remains aligned along the northern Gulf Coast
this morning. A weak mid-level impulse over eastern Texas analyzed
by both the GFS/ECMWF and seen by WV drying/subsidence will rapidly
be advected eastward toward and over our region today.
At the surface, forecast area is situated in a region of SW flow
between a high pressure ridge over south FL/FL straits, and
organizing low pressure across the Central Plains. Very warm
overnight period underway with the flow off the Gulf. Temperatures
as of 4AM EST are still in the middle 60s to around 70 at most
stations with dewpoint just a few degrees lower.
&&
.SHORT TERM (Today through Saturday)...
Today, A warm and humid day for late February on tap. Deep southwest
flow off the Gulf of Mexico will continue to pump abundant low level
moisture into the region. GFS/ECMWF both show 850mb temps rising to
around 15C this afternoon. Model forecast sounding suggest that we
will mix to between 900 and 850mb by the end of the day...away from
the coast. This degree of mixing will result in temperatures pushing
10 degrees above average this afternoon with many inland stations
topping out in the upper 70s to around 80. With enough sunny breaks
lasting into the afternoon, would not be surprised to see a few
lower 80s north of the I-10 corridor. As mentioned in the
synopsis...a weak impulse will be quickly sliding along the northern
Gulf coast and past our region by early this evening. With the
abundant moisture...and some weak synoptic lift ahead of this
impulse, a few isolated showers or thunderstorms can not be
completely ruled out this afternoon. Will add a slight 20% PoP for
the Big Bend and South-Central GA zones to account for this
possibility.
Have issued a wind advisory from 17-00Z today away from the coast
for all zones along and north of the I-10 corridor. Due to the
degree of diurnal mixing...expect to tap into stronger winds just a
bit above the surface by around the midday hour. Sustained winds of
15 to 20 mph look likely, and BUFKIT sounding/WRF algorithms both
suggest gusts to 30 mph will be possible along the I-10 corridor and
possibly over 30 mph north of the FL border. While it will still be
breezy closer to the coast, a less well mixing boundary layer off
the cooler shelf waters should prevent wind advisory criteria from
being met.
Tonight,
Upper trough will continue to amplify over the central CONUS and
push eastward. Associated with this feature, a surface cold front
will also move east and be approaching our western zones toward
sunrise. A few showers or storms along this front will be possible
very late tonight...generally to the west of Dothan. Appears now,
that this will be mostly an anafront configuration, with the
majority of the shower activity occurring in the wake of the frontal
passage. If we can get a storm or 2 ahead of the front, then shear
profiles will be sufficient for organized updrafts and at least some
wind threat. At this point the threat for severe weather appears
minimal, but will continue to monitor. Elsewhere for the rest of the
forecast area, expect a generally dry and warm overnight period.
Friday/Friday Night, Surface cold front will push from NW to SE
across the area during the day. Still some small disagreements on
timing between the global models with the ECMWF about 6 hours slower
than the GFS. Either way, expect a scattering of showers and
isolated thunderstorms to work southeastward along and behind the
front through the day. Doesn`t look like a "washout", but those with
outdoor plans should anticipate dodging a few rain drops. A
continued anafront configuration appears likely which will help
suppress the threat of severe weather. Lingering showers over the
eastern zones Friday Evening will slowly end allowing a cooler and
much drier airmass to arrive by Saturday morning.
Saturday, Appears we will salvage one of the weekend days with some
decent weather. High pressure and a dry low level airmass will keep
our forecast rain-free with highs generally in the lower to mid 60s.
Morning sunshine will likely become quickly filtered by increasing
high clouds during the afternoon as our next potential rain maker
quickly organizes and moves our way for Sunday.
&&
.LONG TERM (Sunday through next Thursday)...
All guidance has now come in line with the GFS with the motion of
the upper low currently near the Baja. This low will slide east
across Mexico through Saturday before being picked up by the main
belt of westerlies and ejecting towards the central gulf coast. As
this system ejects, it will generate a broad area of isentropic
ascent as the warm and moist mid-level flow overrides a cool
low-level airmass. Will be ramping up PoPs significantly for late
Saturday night into Sunday with the new forecast. Cool wedge on
Sunday will be maintained by 1030mb high over the Carolinas. This
should provide a nice feed of relatively dry low-level air into the
region throughout the day, keeping temperatures from rising
significantly. Will undercut the MEX Mos for Sunday, since it is
unlikely to handle the wedge sufficiently.
Main piece of upper energy will exit to the northeast by Monday.
However, with high pressure still in place over the mid-Atlantic and
southerly low- to mid-level winds across the forecast area, still
may see scattered isentropically forced showers across the region
for Monday. Weather appears to remain a bit unsettled on Tuesday
with fast upper flow still in place and enough low-level moisture
that an isolated shower or two cannot be ruled out. A more
significant chance of rain may appear by Wednesday as passing
shortwave pushes a front into the deep south.
&&
.AVIATION..(thru 06Z Thursday)
Plenty of low clouds advecting
across the region this morning on decent southwesterly winds. The
winds should help keep Cigs just above airport mins and keep Vsby up
as well. A windy day is on tap at all terminals today with wind
gusts around 30 knot at KDHN and KABY. Otherwise, should see VFR
conditions this afternoon before MVFR and IFR Cigs return after
sunset tonight.
&&
.MARINE...
A persistent southwest flow will continue through tonight between
high pressure centered east of the Florida Peninsula, and a slowly
approaching cold front to our west. Winds are expected to increase
to cautionary levels this afternoon and continue into the day on
Friday. The cold front will then cross the forecast waters during
the day on Friday shifting winds northerly from west to east. A
period of advisory level winds and seas is anticipated in the wake
of this front Friday night through at least Saturday morning. The
gradient looks to remain tight with elevated winds through the
weekend as weak low pressure develops in the western Gulf and slowly
approaches the region.
&&
.Fire Weather...
Low-level moisture will remain plentiful through Friday ahead of an
approaching cold front. A much drier air mass will spill into the
region on Saturday with RH values falling into the 20s. Moisture and
rain is now expected to quickly return to the area by Sunday into
early next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 65 69 44 63 / 20 10 60 30 0
Panama City 75 65 67 44 62 / 10 10 70 30 10
Dothan 79 62 63 39 62 / 10 20 70 20 0
Albany 81 66 66 39 62 / 10 10 70 20 0
Valdosta 80 65 71 43 62 / 20 10 60 30 0
Cross City 77 62 75 47 66 / 20 10 60 40 10
Apalachicola 70 66 70 46 62 / 20 10 60 30 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...Wind Advisory from 11 AM this morning to 6 PM CST this evening
for Coffee-Dale-Geneva-Henry-Houston.
GA...Wind Advisory from Noon today to 7 PM EST this evening for
Baker-Ben Hill-Berrien-Brooks-Calhoun-Clay-Colquitt-Cook-
Decatur-Dougherty-Early-Grady-Irwin-Lanier-Lee-Lowndes-Miller-
Mitchell-Quitman-Randolph-Seminole-Terrell-Thomas-Tift-Turner-
Worth.
FL...Wind Advisory from Noon EST /11 AM CST/ today to 7 PM EST /6 PM
CST/ this evening for Calhoun-Gadsden-Holmes-Inland
Jefferson-Inland Walton-Jackson-Leon-Liberty-Madison-
Washington.
GM...None.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...CAMP
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
100 PM EST THU FEB 23 2012
.UPDATE...
CURRENT SATELLITE ANALYSIS SHOWS SCATTERED CLOUDS IN NORTH AND
CENTRAL GEORGIA AND A MORE BROKEN TO OVERCAST CLOUD DECK IN
COLUMBUS...EAST INTO MACON. ADJUSTED THE SKY GRIDS TO REPRESENT
THIS. CURRENT SURFACE DEWPOINTS WERE HIGHER THAN FORECAST. AS
SUCH...POPULATED THE GRIDS WITH THE CURRENT 12Z RUC DEWPOINTS THAT
WERE MORE REPRESENTATIVE OF CURRENT OBSERVATIONS AND TRENDS. THIS
MEANT THAT SOME AREAS SAW AN INCREASE OF 5 DEGREES OR MORE IN
DEWPOINT TEMPS. THE NAM SEEMS TO BE UNREALISTICALLY DRYING US OUT
THIS AFTERNOON...AS SUCH BELIEVE THAT THE 06Z NAM MIGHT BE UNDER
REPRESENTING THE CHANCE OF THUNDER. WILL WAIT FOR 12Z GUIDANCE TO
BETTER PIN DOWN THUNDERSTORMS THIS AFTERNOON...EVENING AND INTO
THE OVERNIGHT HOURS. ALSO ADJUSTED THE TEMPS TO BETTER REPRESENT
CURRENT WARMING TRENDS.
ARG
&&
.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 411 AM EST THU FEB 23 2012/
EXPECT TO REMAIN STORM FREE TODAY WITH AREA BETWEEN SYSTEMS.
MODELS DIFFER SLIGHTLY WITH TIMING AND STRENGTH OF NEXT FRONTAL
SYSTEM. THE FASTER AND MORE AGGRESSIVE GFS MODEL PUSHES A COLD
FRONT INTO NW GA SHORTLY AFTER MIDNIGHT TONIGHT...WHILE NAM AND
ECMWF HOLD OFF UNTIL NEARLY 6-7 AM FRIDAY MORNING. PREFER A BLEND
IN THE MORE AGGRESSIVE GFS AND ECMWF MODELS... AS BOTH MODELS SHOW
A GREATER POTENTIAL FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY AHEAD OF THE COLD FRONT...WITH STRONGER UPPER SUPPORT
DIGGING SLIGHTLY FURTHER SOUTH WHILE 600-1200 MUCAPE NOSE INTO
CENTRAL AND NORTH GA LATER THIS EVENING. THIS COUPLED WITH AMPLE
DEEP-LAYER SHEAR COURTESY OF A 50+KT LOW LEVEL SWLY JET SUGGEST
THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS LATER THIS
EVENING AND POSSIBLY CONTINUING OVERNIGHT. SPC HAS NORTH AND PARTS
OF WEST CENTRAL GA IN A SLIGHT RISK AREA FOR TONIGHT AND DESPITE
THE FRONT MOVING INTO THE STATE DURING THE OVERNIGHT HOURS...
SUSPECT LARGE SCALE ASCENT...DEEP- LAYER SHEAR AND FRONTAL FORCING
WILL BE SUFFICIENT FOR ISOLATED SEVERE STORM DEVELOPMENT IN THE
SLIGHT RISK AREA. THE GREATER SEVERE STORM THREAT SEEMS TO BE
BETWEEN 10 PM THIS EVENING AND 6 AM FRIDAY MORNING...AND MAINLY
NORTH OF A LA GRANGE TO ATHENS LINE. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS FROM BOWING STORMS WILL LIKELY BE THE MAIN THREATS
TONIGHT... HIGH 200+ HELICITY VALUES ALSO SUGGEST THE POTENTIAL
FOR A FEW TORNADOES. THE THUNDERSTORM THREAT SHOULD PUSH SOUTH AND
EAST OF THE AREA BY FRIDAY AFTERNOON...ALTHOUGH CLOUDS AND
ISOLATED LIGHT RAIN SHOWERS MAY LINGER THROUGH FRIDAY AFTERNOON AS
THE AXIS OF THE LONG-WAVE UPPER TROUGH DOES NOT PUSH EAST OF THE
STATE UNTIL FRIDAY EVENING. CLEARING...BREEZY AND COOLER
CONDITIONS ARE ON TAP FOR FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WNW. MOS GUIDANCE NUMBERS WERE FAIRLY CLOSE AND
REASONABLE...SO TOOK A BLEND THROUGH THE SHORT TERM.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EST THU FEB 23 2012/
STILL HOLDING ONTO A DRY FORECAST FOR SATURDAY... BUT SUNDAY IS
LOOKING WETTER AS BOTH GFS AND ECMWF ARE SHOWING A BAJA UPPER LOW
FINALLY KICKING EAST AND TRAVERSING THE STATE ON SUNDAY. THIS FEATURE
WILL ENHANCE ISENTROPIC LIFT AND SPREAD RAIN SHOWERS INTO AT LEAST
SOUTH AND CENTRAL GA BY EARLY SUNDAY AFTERNOON. BOTH MODELS SHOW A
WEDGE OF COOL AIR BEING OVERRUN BY A MOIST SOUTHERLY MID LEVEL
FLOW... RESULTING IN A STABLE RAIN SUNDAY AND SUNDAY NIGHT. PREFER
THE DRIER GFS SOLUTION FOR MONDAY AS THIS UPPER SHORT WAVE PUSHES
EAST AND GIVES THE AREA A BREAK. THIS BEFORE ANOTHER FRONTAL
SYSTEM SPREADS A CHANCE OF SHOWERS INTO THE AREA BEGINNING TUESDAY
AND THEN ISOLATED THUNDERSTORMS ON WEDNESDAY JUST AHEAD OF THE
COLD FRONT THAT GFS PUSHES ACROSS THE AREA BY EARLY WEDNESDAY
EVENING.
39
AVIATION...
18Z UPDATE...
VFR CONDITIONS AT THIS TIME WITH A BREEZY SOUTHWEST FLOW. EXPECT
MVFR CIGS AFTER 04Z AS MOISTURE CONTINUES TO PUMP INTO THE STATE IN
ADVANCE OF THE APPROACHING COLD FRONT. THE NAM AND GFS MODELS HAVE
SLOWED THE FRONTAL PASSAGE THROUGH ATL TO AROUND 15Z. EXPECT TSTMS
LIKELY AFTER 09Z WITH LINGERING SHOWERS JUST BEHIND THE FRONT. A
BREEZY WEST TO NORTHWEST FLOW WITH DECREASING CLOUDS WILL PREVAIL ON
FRIDAY AFTER 15Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON ALL ELEMENTS.
16
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 57 63 35 / 10 60 60 10
ATLANTA 75 54 59 35 / 10 70 50 10
BLAIRSVILLE 68 51 55 29 / 10 70 40 10
CARTERSVILLE 75 52 60 32 / 10 70 40 10
COLUMBUS 76 58 62 38 / 10 60 60 10
GAINESVILLE 72 54 62 34 / 10 70 50 10
MACON 78 62 65 36 / 10 50 60 20
ROME 75 52 61 32 / 10 70 40 10
PEACHTREE CITY 76 53 60 31 / 10 60 50 10
VIDALIA 81 64 69 42 / 10 40 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1025 AM EST THU FEB 23 2012
.UPDATE...
CURRENT SATELLITE ANALYSIS SHOWS SCATTERED CLOUDS IN NORTH AND
CENTRAL GEORGIA AND A MORE BROKEN TO OVERCAST CLOUD DECK IN
COLUMBUS...EAST INTO MACON. ADJUSTED THE SKY GRIDS TO REPRESENT
THIS. CURRENT SURFACE DEWPOINTS WERE HIGHER THAN FORECAST. AS
SUCH...POPULATED THE GRIDS WITH THE CURRENT 12Z RUC DEWPOINTS THAT
WERE MORE REPRESENTATIVE OF CURRENT OBSERVATIONS AND TRENDS. THIS
MEANT THAT SOME AREAS SAW AN INCREASE OF 5 DEGREES OR MORE IN
DEWPOINT TEMPS. THE NAM SEEMS TO BE UNREALISTICALLY DRYING US OUT
THIS AFTERNOON...AS SUCH BELIEVE THAT THE 06Z NAM MIGHT BE UNDER
REPRESENTING THE CHANCE OF THUNDER. WILL WAIT FOR 12Z GUIDANCE TO
BETTER PIN DOWN THUNDERSTORMS THIS AFTERNOON...EVENING AND INTO
THE OVERNIGHT HOURS. ALSO ADJUSTED THE TEMPS TO BETTER REPRESENT
CURRENT WARMING TRENDS.
ARG
&&
.SHORT TERM /TODAY THROUGH SATURDAY NIGHT/...
/ISSUED 411 AM EST THU FEB 23 2012/
EXPECT TO REMAIN STORM FREE TODAY WITH AREA BETWEEN SYSTEMS.
MODELS DIFFER SLIGHTLY WITH TIMING AND STRENGTH OF NEXT FRONTAL
SYSTEM. THE FASTER AND MORE AGGRESSIVE GFS MODEL PUSHES A COLD
FRONT INTO NW GA SHORTLY AFTER MIDNIGHT TONIGHT...WHILE NAM AND
ECMWF HOLD OFF UNTIL NEARLY 6-7 AM FRIDAY MORNING. PREFER A BLEND
IN THE MORE AGGRESSIVE GFS AND ECMWF MODELS... AS BOTH MODELS SHOW
A GREATER POTENTIAL FOR MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY AHEAD OF THE COLD FRONT...WITH STRONGER UPPER SUPPORT
DIGGING SLIGHTLY FURTHER SOUTH WHILE 600-1200 MUCAPE NOSE INTO
CENTRAL AND NORTH GA LATER THIS EVENING. THIS COUPLED WITH AMPLE
DEEP-LAYER SHEAR COURTESY OF A 50+KT LOW LEVEL SWLY JET SUGGEST
THE POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS LATER THIS
EVENING AND POSSIBLY CONTINUING OVERNIGHT. SPC HAS NORTH AND PARTS
OF WEST CENTRAL GA IN A SLIGHT RISK AREA FOR TONIGHT AND DESPITE
THE FRONT MOVING INTO THE STATE DURING THE OVERNIGHT HOURS...
SUSPECT LARGE SCALE ASCENT...DEEP- LAYER SHEAR AND FRONTAL FORCING
WILL BE SUFFICIENT FOR ISOLATED SEVERE STORM DEVELOPMENT IN THE
SLIGHT RISK AREA. THE GREATER SEVERE STORM THREAT SEEMS TO BE
BETWEEN 10 PM THIS EVENING AND 6 AM FRIDAY MORNING...AND MAINLY
NORTH OF A LA GRANGE TO ATHENS LINE. ALTHOUGH LARGE HAIL AND
DAMAGING WINDS FROM BOWING STORMS WILL LIKELY BE THE MAIN THREATS
TONIGHT... HIGH 200+ HELICITY VALUES ALSO SUGGEST THE POTENTIAL
FOR A FEW TORNADOES. THE THUNDERSTORM THREAT SHOULD PUSH SOUTH AND
EAST OF THE AREA BY FRIDAY AFTERNOON...ALTHOUGH CLOUDS AND
ISOLATED LIGHT RAIN SHOWERS MAY LINGER THROUGH FRIDAY AFTERNOON AS
THE AXIS OF THE LONG-WAVE UPPER TROUGH DOES NOT PUSH EAST OF THE
STATE UNTIL FRIDAY EVENING. CLEARING...BREEZY AND COOLER
CONDITIONS ARE ON TAP FOR FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WNW. MOS GUIDANCE NUMBERS WERE FAIRLY CLOSE AND
REASONABLE...SO TOOK A BLEND THROUGH THE SHORT TERM.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
/ISSUED 411 AM EST THU FEB 23 2012/
STILL HOLDING ONTO A DRY FORECAST FOR SATURDAY... BUT SUNDAY IS
LOOKING WETTER AS BOTH GFS AND ECMWF ARE SHOWING A BAJA UPPER LOW
FINALLY KICKING EAST AND TRAVERSING THE STATE ON SUNDAY. THIS FEATURE
WILL ENHANCE ISENTROPIC LIFT AND SPREAD RAIN SHOWERS INTO AT LEAST
SOUTH AND CENTRAL GA BY EARLY SUNDAY AFTERNOON. BOTH MODELS SHOW A
WEDGE OF COOL AIR BEING OVERRUN BY A MOIST SOUTHERLY MID LEVEL
FLOW... RESULTING IN A STABLE RAIN SUNDAY AND SUNDAY NIGHT. PREFER
THE DRIER GFS SOLUTION FOR MONDAY AS THIS UPPER SHORT WAVE PUSHES
EAST AND GIVES THE AREA A BREAK. THIS BEFORE ANOTHER FRONTAL
SYSTEM SPREADS A CHANCE OF SHOWERS INTO THE AREA BEGINNING TUESDAY
AND THEN ISOLATED THUNDERSTORMS ON WEDNESDAY JUST AHEAD OF THE
COLD FRONT THAT GFS PUSHES ACROSS THE AREA BY EARLY WEDNESDAY
EVENING.
39
AVIATION...
12Z UPDATE...
/ISSUED 657 AM EST THU FEB 23 2012/
IMPROVING CONDITIONS EXPECTED THROUGH THE DAY...WITH VFR EXPECTED
BY 18Z. CIGS WILL DEGRADE INTO THE OVERNIGHT HOURS AS SHORTWAVE
MOVES INTO THE AREA. EXPECT MVFR BY 09Z. CONDITIONS WILL IMPROVE
QUICKLY AFTER 12Z FRI. BEST RAIN CHANCES 09-12Z. SW WINDS WILL
INCREASE TO 12-14KTS BY 18Z...WITH GUSTS TO 22-25KTS. SPEEDS
REMAIN HIGH OVERNIGHT WITH W-WSW WINDS AT 8-12KTS.
//ATL CONFIDENCE...12Z UPDATE...
HIGH ON WINDS AND DIRECTION.
MEDIUM ON ALL OTHER ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 57 63 35 / 10 60 60 10
ATLANTA 75 54 59 35 / 10 70 50 10
BLAIRSVILLE 68 51 55 29 / 10 70 40 10
CARTERSVILLE 75 52 60 32 / 10 70 40 10
COLUMBUS 76 58 62 38 / 10 60 60 10
GAINESVILLE 72 54 62 34 / 10 70 50 10
MACON 78 62 65 36 / 10 50 60 20
ROME 75 52 61 32 / 10 70 40 10
PEACHTREE CITY 76 53 60 31 / 10 60 50 10
VIDALIA 81 64 69 42 / 10 40 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
26
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
400 AM EST THU FEB 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /TODAY/...
RADAR CURRENTLY INDICATES A FEW LINGERING SHOWERS OVER PORTIONS
OF THE FORECAST AREA. WILL EXPECT THIS ACTIVITY TO CONTINUE TO
GRADUALLY DISSIPATE BY DAYBREAK. LOW PRESSURE DEVELOPING OVER THE
MID MISS AND OHIO VALLEYS TODAY WILL PROVIDE BREEZY CONDITIONS FOR
OUR FA TODAY. WIND GUSTS AROUND 25 OR 30 MPH EXPECTED OVER LAND
AREAS THIS AFTERNOON...BUT WITH LESS MIXING OVER COOLER LAKE
WATERS...LAKE WIND ADVISORY (LWA) CONDITIONS MAY NOT BE MET ON
AREA LAKES. PER COORDINATION WITH CHS...HELD OFF ON LWA AGAIN
TODAY. SW WINDS PROVIDING WARM TEMPS. GENERALLY FORECASTING MAX
TEMPS NEAR 80 TODAY. RECORD HIGHS FOR TODAY ARE 82 AT CAE...AND 81
AT AGS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. SURFACE LOW
PRESSURE WELL TO OUR NORTH WILL CONTINUE TO INTENSIFY AND MOVE
NE...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. BEST UPPER
ENERGY TO REMAIN JUST TO OUR NORTH. STRONG MID TO LOW LEVEL JETS
EXPECTED ACROSS OUR REGION AGAIN THU NT INTO FRI AS THE FRONT
MOVES THROUGH...LEADING TO SVR POSSIBILITIES. SPC HAS REGION IN
SLIGHT RISK. MODELS MOVE FRONT OUT OF OUR REGION FRI EVENING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
236 AM EST THU FEB 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD
INTO THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AREAL COVERAGE HAS DECREASED SOME...BUT A BAND OF SCATTERED
SHOWERS AND A FEW THUNDERSTOMS CONTINUES TO MOVE ESE ACROSS
PORTIONS OF THE CENTRAL AND NORTHERN FA. WILL EXPECT THIS ACTIVITY
TO CONTINUE TO MOVE ACROSS THE FA AND GRADUALLY DISSIPATE BY
DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. LOW
PRESSURE WILL DEVELOP OVER THE MISS VALLEY AND SHIFT NE AND
INTENSIFY...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. BREEZY
CONDITIONS EXPECTED THU/FRI AHEAD OF THE FRONT. WIND GUSTS AROUND
25 MPH EXPECTED OVER LAND AREAS THIS AFTERNOON...BUT WITH LESS
MIXING OVER COOLER LAKE WATERS...LAKE WIND ADVISORY (LWA)
CONDITIONS MAY NOT BE MET ON AREA LAKES. PER COORDINATION WITH
CHS...HELD OFF ON LWA AGAIN TODAY. SW WINDS PROVIDING WARM TEMPS.
GENERALLY FORECASTING MAX TEMPS NEAR 80 TODAY. RECORD HIGHS FOR
TODAY ARE 82 AT CAE...AND 81 AT AGS. BEST UPPER ENERGY TO REMAIN
JUST TO OUR NORTH. STRONG MID TO LOW LEVEL JETS EXPECTED ACROSS
OUR REGION AGAIN THU NT INTO FRI AS THE FRONT MOVES THROUGH...LEADING
TO SVR POSSIBILITIES. SPC HAS REGION IN SLIGHT RISK. MODELS MOVE
FRONT OUT OF OUR REGION FRI EVENING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1250 AM EST THU FEB 23 2012
.SYNOPSIS...
AN UPPER DISTURBANCE AND SURFACE LOW MOVING BY TO OUR NORTH WILL
PROVIDE A CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS...MAINLY
ACROSS THE NORTHERN HALF OF THE STATE TONIGHT. A COLD FRONT WILL
MOVE THROUGH FRIDAY. HIGH PRESSURE WILL BUILD INTO THE AREA THIS
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
RADAR INDICATES LINE OF SHOWERS AND A FEW THUNDERSTORMS STRETCHING
FROM CENTRAL NC SW ACROSS THE UPSTATE SC...APPROACHING OUR N
FA...AND SW INTO NE GA AND PORTIONS OF ALA. THE ACTIVITY
CONTINUES TO HOLD TOGETHER AND PROGRESS TO THE ESE. 00Z SPC WRF
AND LATEST VSREF INDICATING ACTIVITY TO TRAVERSE OUR FA OVERNIGHT.
UPPED THE POPS FOR THE OVERNIGHT PERIOD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
DEEPER UPPER TROUGH WILL SHIFT ACROSS THE EASTERN CONUS. LOW
PRESSURE WILL DEVELOP OVER THE MS VALLEY AND SHIFT NE AND
INTENSIFY...DRAGGING A FRONT THROUGH OUR REGION FRIDAY. STRONG WAA
ON THURSDAY WILL DRIVE AFTERNOON TEMPS WELL INTO THE LOWER TO
MIDDLE 70S ACROSS MUCH OF THE AREA. BREEZY CONDITIONS EXPECTED
THU/FRI AHEAD OF THE FRONT. BEST UPPER ENERGY TO REMAIN JUST TO
OUR NORTH. CURRENT DAY TWO CONVECTIVE OUTLOOK HAS MUCH OF CWA IN
GENERAL TSTM AREA FOR FRIDAY. STRONG MID TO LOW LEVEL JETS EXPECTED
ACROSS OUR REGION AGAIN THU NT INTO FRI...SO AN ISOLATED
STRONG/BORDERLINE SVR STORM NOT OUT OF THE QUESTION. FEW OVERALL
CHANGES FROM PREVIOUS FORECAST. STILL QUITE A SPREAD IN GFS
ENSEMBLE POP NUMBERS. LATEST SREF POPS MAINLY IN THE CHANCE RANGE
LATE THU NT INTO FRI AFTN. IN GENERAL USED MODEL BLEND BETWEEN
GMOS AND ONGOING FORECAST FOR TEMPS AND POPS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
STILL LOTS OF UNCERTAINTY WITH THE FORECAST IN THE EXTENDED PERIOD
DUE TO MODEL INCONSISTENCIES. AS A RESULT...HAVE MADE FEW CHANGES
TO THE ONGOING FORECAST. CUT OFF UPPER LOW OVER BAJA CA WILL LIFT
OUT TO THE EAST OVER THE NEXT COUPLE OF DAYS. MODELS HAVE TIMING
DIFFERENCES. AT THE SURFACE...A COUPLE OF FRONTAL SYSTEMS WILL
BRING A CHANCE FOR RAIN DURING THE FIRST PART OF NEXT WEEK. LOW
CONFIDENCE WITH THE TIMING OF THESE WEATHER FEATURES...SO HAVE
MADE ONLY MINOR CHANGES TO THE LONG TERM FORECAST. TEMPERATURES
MAINLY CLOSE TO OR JUST ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MOS GUIDANCE IS GIVING IFR CONDITIONS EARLY THIS MORNING NEAR
SUNRISE BUT LOW LEVEL WINDS HAVE INCREASE ACROSS THE REGION AND
SOME CONVECTION IS OCCURRING IN THE NORTHERN PART OF THE FORECAST
AREA. CONDITIONS ARE CURRENTLY VFR ACROSS THE AREA. WITH WINDS...
OPTED FOR MAINLY VFR CONDITIONS ALTHOUGH AN INCREASE IN LOW LEVEL
MOISTURE AHEAD AN APPROACHING COLD FRONT MAY BRING CIGS 3-4 KFT IN
BETWEEN 08Z-12Z THIS MORNING. THINK SOUTHWEST SURFACE WINDS 10-15
KNOTS WILL PROHIBIT FOG FORMATION. RUC MODEL SHOWS A WEAK SHORT
WAVE PASSING THROUGH 06Z-12Z TIME FRAME AS WELL. WILL INCLUDE
TEMPO GROUPS 08Z-10Z FOR MVFR CONDITIONS IN SHOWERS. BUT IT LOOKS
LIKE THE ACTIVITY WILL CLEAR THE REGION TO THE EAST 10Z-12Z TIME
FRAME. WITH INCREASED LOW LEVEL WINDS AT 2 KFT...DECIDED TO
MENTION LOW LEVEL WIND SHEAR ALL TAF STIES 06Z-10Z WITH 2 KFT WINDS
23040 KNOTS AND 24050 KNOTS DURING THE PERIOD. AFTER 10Z...THINK
STRONGER WINDS WILL MIX DOWN TO THE SURFACE AND WILL HAVE SOUTHWEST
WINDS 15-20 KNOTS FOR THE REST OF THE DAY. THE COLD FRONT WILL
APPROACH LATE THURSDAY NIGHT NEAR MIDNIGHT. THERE MAY BE SOME
SHOWERS OR THUNDERSTORMS BUT WILL NOT MENTION FOR TIME BEING DUE
TO TIMING ISSUES AND UNCERTAINTY TO COVERAGE.
EXTENDED AVIATION OUTLOOK...MVFR AND POSSIBLE IFR CONDITIONS MAY
OCCUR LATE THURSDAY NIGHT AND FRIDAY AS THE COLD FRONT PUSHES
THROUGH THE REGION. SOME THUNDERSTORMS MAY ALSO ACCOMPANY THE FRONT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...07
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
326 AM EST THU FEB 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GUIDANCE IS IN GENERAL AGREEMENT ON TWO SYSTEMS OF NOTE IN THE
LONG TERM PERIOD...THE FIRST ONE BEING A WEAKENING LOW PUSHING
THROUGH THE GREAT LAKES LATE IN THE WEEKEND/EARLY IN THE WORK
WEEK...AND THE SECOND BEING A STRONGER MORE SIGNIFICANT SYSTEM
PUSHING THROUGH INDIANA/THE LOWER GREAT LAKES REGION TOWARD
MIDWEEK.
GIVEN THIS AGREEMENT...WILL DEVIATE LITTLE FROM ALLBLEND...WHICH
HAS SLIGHT CHANCE POPS FOR THE TRAILING FRONTAL BOUNDARY OF THE
INITIAL SYSTEM...AND STRONGER CHANCE POPS WTIH THE SECOND. THIS
APPEARS REASONABLE. MOST ALL PRECIPITATION IN THE LONG TERM
APPEARS LIKELY TO BE RAIN.
GIVEN UPPER LEVEL FLOW THAT IS ZONAL TO WEAKLY ANTICYCLONIC IN
BETWEEN SYSTEMS...MODERATE TO SOMEWHAT WARMER THAN NORMAL
TEMPERATURES ALSO APPEAR REASONABLE...AND NO DEVIATIONS WERE
NECESSARY.
&&
.AVIATION /DISCUSSION FOR THE 23/09Z IND TAF UPDATE/...
NO CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....NIELD
AVIATION...TUCEK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 AM EST THU FEB 23 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
GUIDANCE IS IN GENERAL AGREEMENT ON TWO SYSTEMS OF NOTE IN THE
LONG TERM PERIOD...THE FIRST ONE BEING A WEAKENING LOW PUSHING
THROUGH THE GREAT LAKES LATE IN THE WEEKEND/EARLY IN THE WORK
WEEK...AND THE SECOND BEING A STRONGER MORE SIGNIFICANT SYSTEM
PUSHING THROUGH INDIANA/THE LOWER GREAT LAKES REGION TOWARD
MIDWEEK.
GIVEN THIS AGREEMENT...WILL DEVIATE LITTLE FROM ALLBLEND...WHICH
HAS SLIGHT CHANCE POPS FOR THE TRAILING FRONTAL BOUNDARY OF THE
INITIAL SYSTEM...AND STRONGER CHANCE POPS WTIH THE SECOND. THIS
APPEARS REASONABLE. MOST ALL PRECIPITATION IN THE LONG TERM
APPEARS LIKELY TO BE RAIN.
GIVEN UPPER LEVEL FLOW THAT IS ZONAL TO WEAKLY ANTICYCLONIC IN
BETWEEN SYSTEMS...MODERATE TO SOMEWHAT WARMER THAN NORMAL
TEMPERATURES ALSO APPEAR REASONABLE...AND NO DEVIATIONS WERE
NECESSARY.
&&
.AVIATION /DISCUSSION FOR THE 23/06Z TAFS/...
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....NIELD
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1209 AM EST THU FEB 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A CHAOTIC WEATHER PATTERN FOR THE NEXT FEW DAYS WILL LEAD TO CHANCES
FOR RAIN...THUNDERSTORMS...AND SNOW OVER THE NEXT COUPLE OF DAYS.
QUIET WEATHER FOR THE WEEKEND WILL GIVE WAY TO LOW CHANCES FOR RAIN
OR SNOW EARLY IN THE WORK WEEK.
&&
.NEAR TERM /TONIGHT/...
EVENING UPDATE #2...THIN CONVECTIVE LINE HAS QUICKLY DEVELOPED
OVER SOUTHWEST INDIANA JUST SOUTH OF THE FORECAST AREA OVER THE
LAST 30-45 MINUTES. THIS APPEARS TO BE ALONG THE WEAK BOUNDARY
PROGRESSING THROUGH THE SOUTHERN PART OF THE FORECAST AREA.
MESOANALYSIS ALSO SHOWING THAT THIS AREA SITS RIGHT ON THE EDGE OF
THE INSTABILITY AXIS EXTENDING SOUTH INTO THE LOWER MISSISSIPPI
VALLEY. ALSO APPEARS TO HAVE SOME UPPER SUPPORT AIDING DEVELOPMENT
AS TROUGH AXIS ALOFT IS OVERHEAD. HRRR HAS A NICE HANDLE ON
CURRENT DEVELOPMENT...EXPANDING IT EAST ALONG THE OHIO RIVER
VALLEY THIS EVENING. HAVE INSERTED LOW CHANCE POPS OVER FAR
SOUTHERN COUNTIES TO ACCOUNT FOR NORTHERN PART OF THE LINE
CLIPPING SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE
EVENING. ANY PRECIP SHOULD BE EAST OF THE FORECAST AREA BY
MIDNIGHT AS WEAK RIDGING BUILDS IN.
PREVIOUS DISCUSSION FOLLOWS.
QUICK UPDATE TO ADDRESS THE GUSTY WINDS PERSISTING ALONG AND AHEAD
OF A WEAK BOUNDARY. HAVE SEEN MAX WIND GUSTS IN EXCESS OF 30MPH OVER
THE LAST HOUR OR TWO...ESPECIALLY NEAR AND SOUTH OF I-70. REPORTS OF
VIRGA DUE TO DRY AIR THROUGH THE BOUNDARY LAYER AND RADAR RETURNS
CURRENTLY SUPPORTING THIS. WITH 35-40KT JET NOTED ALOFT AT
850MB...THERE IS LIKELY SOME MIXING DOWN OF THE STRONGER WINDS AT
4-5KFT GOING ON AND CONTRIBUTING TO THE ENHANCEMENT IN WIND GUSTS.
HAVE THEREFORE BUMPED UP WIND GUSTS FOR THE DURATION OF THE
EVENING...ESPECIALLY NEAR AND SOUTH OF I-70. WINDS SHOULD DROP OFF
BY LATE EVENING AS LOW LEVEL JET SHIFTS EAST WITH SURFACE BOUNDARY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THERE IS QUITE A BIT OF DISAGREEMENT AMONG THE MODELS ON THE TRACK
OF THE SURFACE LOW THURSDAY INTO FRIDAY AND THIS WILL HAVE A BIG
IMPACT ON THE WEATHER THAT ENSUES. THE ECMWF TAKES THE LOW SOUTH OF
THE AREA WITH AGREEMENT FROM THE UKMET AND ECMWF ENSEMBLES...WHILE
THE GFS/NAM/ AND SREFS TAKE THE TRACK THROUGH ACROSS THE NORTHERN
PART OR JUST NORTH OF THE AREA. THE GEM SEEMED TO BE A SOLUTION IN
BETWEEN THOSE TWO CAMPS AND THUS TRENDED TOWARD IT.
A WARM FRONT SHOULD BE FORMING ACROSS OR JUST SOUTH OF THE AREA
THURSDAY MORNING AND THIS SHOULD PROVIDE FORCING FOR OVERRUNNING
RAIN SHOWERS WITH THE BEST CHANCES IN THE NORTHERN COUNTIES. AS THE
LOW PRESSURE MOVES ACROSS OR BY THE AREA THROUGH THE DAY IT COULD
DRAG A COLD FRONT THROUGH BY AROUND 0Z...AND WITH A 40 KT LOW LEVEL
JET FORMING UP SOUTH OF THE AREA IN THE AFTERNOON AND SOME ELEVATED
INSTABILITY AVAILABLE COULD SEE SOME THUNDERSTORMS FORM IN THE
AFTERNOON ESPECIALLY IN THE SOUTHERN COUNTIES. WHILE SPC GENERAL
THUNDER OUTLOOK ENCOMPASSES THE ENTIRE FORECAST AREA...THINK THAT
THE BEST CHANCES WILL REMAIN IN THE SOUTHERN COUNTIES WITH ONLY
ISOLATED THUNDER CENTRAL AND PROBABLY NO THUNDER IN THE NORTH. WHILE
AN ISOLATED SEVERE STORM IN THE SOUTH CANNOT BE RULED OUT...BEST
CHANCES FOR SEVERE SHOULD REMAIN SOUTH OF THE AREA.
BY THURSDAY NIGHT THE SYSTEM SHOULD BE MOVING OUT OF THE
AREA...ALTHOUGH SOME UPPER FORCING WILL REMAIN WEST OF THE AREA.
COLD AIR IS LAGGING BEHIND THE FRONT AND THUS WILL KEEP CHANCES FOR
RAIN ACROSS ALL BUT THE NORTHWEST WHERE SNOW COULD MIX IN BEFORE
6Z...AND EXPAND THE MIX ACROSS THE AREA FROM 6-12Z. COULD SEE SOME
STRONG WINDS IN THE WAKE OF THE LOW ON THURSDAY NIGHT AND FRIDAY
DEPENDING ON THE EXACT TRACK. FOR FRIDAY KEPT A CHANCE FOR RAIN OR
SNOW GOING FOR MOST OF THE AREA WITH RAIN CHANCE IN THE FAR SOUTH
BASED ON THE LITTLE FORCING LEFT FROM THE UPPER TROUGH...BUT NOT
ENOUGH TO GO BEYOND A SMALL CHANCE. THE SYSTEM WILL MOVE OUT ON
FRIDAY NIGHT LEAVING A CHANCE FOR SNOW IN THE NORTHEAST AS IT
EXITS...AND BY SATURDAY THE AREA SHOULD BE DRY.
FOR TEMPERATURES GENERALLY USED A CONSENSUS WITH A NUDGE TOWARD THE
GEM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER TROUGH MOVING ACROSS THE NORTHERN U.S. WILL AFFECT OUR
WEATHER AROUND MONDAY. HOWEVER MODELS HAVE TRENDED WITH LESS PRECIP
WITH THIS SYSTEM. I AM NOT CONFIDENT ENOUGH TO TAKE OUT CHANCE OF
PRECIP MONDAY...BUT WILL DROP MENTION ACROSS OUR SOUTHEAST HALF
SUNDAY NIGHT AND ALL AREAS MONDAY MONDAY NIGHT.
A SECOND AND POTENTIALLY MUCH STRONGER SYSTEM WILL AFFECT OUR
WEATHER BY THE MIDDLE OF NEXT WEEK. BOTH 12Z EURO AND 12Z GFS BRINGS
SIGNIFICANT PRECIP BY DAY 7. THERE IS A LOT OF DISAGREEMENT IN THE
SURFACE LOW TRACK AND ULTIMATELY PRECIP TYPE. AT THIS TIME MY
CONFIDENCE IS LOW...SO FOR NOW WILL RAISE ALL BLEND TEMPS TUESDAY
NIGHT AND LOWER THEM WEDNESDAY TO REDUCE THE DIURNAL RANGE. THIS
WOULD GIVE ME SNOW TUESDAY NIGHT WITH MIXED PRECIP SOUTH AND MOSTLY
RAIN WEDNESDAY. CONFIDENCE IS LOW ON PRECIP TYPE...BUT THIS MIDDLE
OF THE ROAD APPROACH SEEMS BEST WAY TO GO UNTIL MODELS HAVE A BETTER
AGREEMENT.
&&
.AVIATION /DISCUSSION FOR THE 23/06Z TAFS/...
VFR EXPECTED THRU FCST PERIOD FOR KHUF AND KBMG. MVFR AT KIND AND
KLAF AFTER 231900Z. SHRA AT SITES AFTER 231300Z. STRONG GUSTY WEST
WIND AFTER 240200Z.
MODELS BEGINNING TO COME TOGETHER SOMEWHAT IN DEVELOPING STORM
SYSTEM OVER CENTRAL PLAIN STATES EARLY THURSDAY AND SWEEPING IT
ACROSS CENTRAL INDIANA THURSDAY EVENING. SHOWER BAND WILL DEVELOP
AHEAD OF SYSTEM LIFTING NE ACROSS ROUTES BY 231300Z. COUPLE MODELS
DESTABILIZE AIR ACROSS SOUTHERN INDIANA BY 232100Z HINTING AT
THUNDERSTORM POTENTIAL...PERHAPS KIND...BETTER AT KBMG...BUT THUNDER
THREAT WOULD ONLY LAST THRU 240000Z.
MORE SIGNIFICANT ISSUE MAY BE STRONG AND GUSTY WEST WIND AFTER
240200Z AS DEEEPENING LOW LIFTS NE INTO NE OHIO BY FRIDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....JH
AVIATION...TUCEK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
347 AM CST THU FEB 23 2012
.DISCUSSION...
FAST UPPER FLOW CONTINUES TODAY...AND GIVING THE FORECAST MANY
CHALLENGES. DEVELOPING UPPER WAVE IN THE NORTHERN PLAINS WITH
100-150M 500MB HEIGHT FALLS IN THE PACIFIC NORTHWEST WAS MAKING
QUICK SOUTHEAST PROGRESS INTO THE PLAINS EARLY THIS MORNING.
INCREASING MID LEVEL FRONTOGENESIS IN THE CENTRAL PLAINS AND STRONG
ISENTROPIC LIFT AROUND 300K HAS BEEN SUFFICIENT TO OVERCOME DRY
LOWER LEVELS AND BRING VERY LIGHT PRECIP TO NORTHERN KANSAS SINCE
LATE EVENING...BUT RADAR TRENDS SEEM TO BE GOING ALONG WITH MODELS
IN LIFT DIMINISHING TOWARD SUNRISE. SURFACE PATTERN RATHER JUMBLED
AT 08Z WITH SURFACE LOWS IN SOUTHWEST KANSAS...SOUTH CENTRAL
NEBRASKA...AND SOUTHERN SOUTH DAKOTA. WHERE MIXING AND CLOUDS HAVE
PERSISTED...TEMPS REMAIN RATHER MILD...WITH NORTHWEST WINDS BEHIND
THE LOWS ALLOWING MUCH COOLER READINGS TO OCCUR. A FEW 30-40KT
SUSTAINED SPEED OBSERVATIONS WERE NOTED IN WESTERN SOUTH DAKOTA.
UPPER TROF TO CONTINUE TO DEEPEN AS IT ZIPS SOUTHEAST TODAY...WITH
DEEP AND STRONG COLD AIR ADVECTION AND MIXING BEHIND SURFACE LOW
PRESSURE TRACKING EAST THROUGH KANSAS. SOME DIFFERENCES IN SPECIFIC
TIMING AND STRENGTH OF WINDS BEHIND IT...BUT ADVISORY LEVELS SHOULD
BE EASY TO ATTAIN GIVEN GOOD DOWNWARD MOTION AND 925MB WINDS IN THE
30-50KT RANGE. CANNOT RULE OUT A FEW LOCATIONS REACHING WARNING
LEVELS BRIEFLY...BUT DO NOT THINK IT WILL BE LONG-LIVED OR
WIDESPREAD. STRONG MIXING SHOULD PERSIST INTO THE EVENING
HOURS...KEEPING WINDS ON THE HIGH SIDE IN AT LEAST EASTERN AREAS
AFTER DARK. ADVISORY BREAKDOWN IS BASED ON EXPECTED NNW-SSE ONSET OF
WINDS EARLY TODAY AND BETTER GRADIENT INTO THE EVENING IN THE EAST.
TEMPERATURE TRENDS ALSO TRICKY WITH THE AFOREMENTIONED
CONSIDERATIONS ON HOW THINGS WILL START NEAR DAWN WHILE MIXING WILL
INCREASE QUICKLY BUT INTO 850MB TEMPS DROPPING 6-10C IN THE MORNING.
HAVE INCREASED THE RANGES ACROSS THE AREA BUT CONFIDENCE IS LOW ON
SPECIFIC HOURLY VALUES. MUCH OF THE AREA TO BE ON THE SUBSIDENCE
SIDE OF THE SYSTEM...BUT PRECIP MAY SWING SOUTH THROUGH EASTERN
NEBRASKA AS THE UPPER TROF ENTERS IOWA AND THREATEN NORTHERN AREAS
BY LATE THIS AFTERNOON. WILL INCLUDE SMALL PROBABILITIES FOR THIS
OCCURRENCE INTO THE EVENING. ANY AMOUNTS SHOULD BE LIGHT AND MOSTLY
RAIN...THOUGH IF IT CAN HANG ON INTO THE EVENING...SNOW COULD RESULT
IN LIMITED VISIBILITIES IN THE STILL GUSTY WINDS.
DEEP MIXING AGAIN EXPECTED ON FRIDAY...THOUGH ADVISORY LEVELS NOT
NEARLY AS LIKELY...AND STILL APPEARS BIGGEST ADVISORY ISSUE WOULD BE
WINDS IN THE STEEP LAPSE RATES TO AROUND 600MB. THE MIXING SHOULD
GIVE RISE TO SOME MID CLOUD..AND CANNOT RULE OUT SOME HIGH-BASED
SHOWERS RESULTING IN TRACE PRECIP IN THE AFTERNOON. WILL LET LATER
SHIFTS DETERMINE DETAILS ON THIS.
FRIDAY NIGHT TO BE ON THE TRANQUIL SIDE FOR THIS FORECAST WITH
LITTLE CLOUD AND WEAK WINDS BEYOND 02Z...BUT THE WIND MACHINE STARTS
UP AGAIN BY LATE SATURDAY WITH THE NEXT UPPER TROF APPROACHING FROM
THE WEST. A 20MB PRESSURE GRADIENT IS PROGGED BY LATE DAY...WITH
925MB WINDS NEAR 60KT FOR SATURDAY NIGHT. LOW LEVEL RIDGING BEHIND
THE CURRENT SYSTEM SHOULD KEEP MOISTURE IN CHECK FOR DRY CONDITIONS
DESPITE WARM AIR ADVECTION.
PRECIP CHANCES CONTINUE TO WANE ON INTO SUNDAY NIGHT WITH GFS AND
ECMWF VERY SIMILAR WITH A LACK OF ENERGY CUTTING OFF BEHIND THE TROF
AS EARLIER RUNS ADVERTISED. TIMING DIFFERENCES CONTINUE FOR THE NEXT
SYSTEM AND CHANGES TO THE FORECAST FOR THE MID WEEK WERE SMALL AT
THIS RANGE. SIMILAR RHS LIKELY FOR FRIDAY AS WELL WITH ELEVATED FIRE
WEATHER RESULTING WITH BREEZY NORTHWEST WINDS.
65
&&
.FIRE WEATHER...
ANOTHER DAY OF VERY HIGH TO NEAR EXTREME CONDITIONS FORECAST WITH
VERY HIGH WINDS THE MAIN PLAYER. CONFIDENCE ON TEMPERATURE AND
DEWPOINT VALUES GIVE RISE TO MUCH UNCERTAINTY IN HUMIDITIES. ERRING
ON THE DRY SIDE STILL KEEPS RHS IN THE 30-PLUS RANGE. WITH WET
GROUND FROM RECENT RAINS ALSO IN PLAY...WILL HOLD OFF ON ANY WATCHES
OR WARNINGS AT THIS POINT.
65
&&
.AVIATION...
RADAR WOULD SUGGEST THAT THERE IS A NARROW BAND OF FRONTOGENESIS
ALONG WITH SOME QG FORCING THAT HAS ALLOWED THE LIGHT RAIN TO
DEVELOP OVER THE AREA. RUC AND NAM PROGS SUGGEST THAT THIS WILL
STICK AROUND A FEW MORE HOURS...THOUGHT CONDITIONS SHOULD REMAIN VFR
THROUGH THE DAY. THERE IS SOME INDICATION OF WRAP AROUND LOW LEVEL
MOISTURE MOVING IN AROUND 00Z FRI. THINK THIS SHOULD REMAIN ABOVE 3
KFT. MODELS ARE COMING IN WITH A STRONGER PRESSURE GRADIENT.
THEREFORE HAVE INCREASED WINDS AND GUSTS FOR THE DAY THURSDAY.
WOLTERS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR
KSZ011-012-024-026-038>040-054>056-058-059.
WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR KSZ008>010-020>023-034>037.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1114 PM CST WED FEB 22 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
RADAR WOULD SUGGEST THAT THERE IS A NARROW BAND OF FRONTOGENESIS
ALONG WITH SOME QG FORCING THAT HAS ALLOWED THE LIGHT RAIN TO
DEVELOP OVER THE AREA. RUC AND NAM PROGS SUGGEST THAT THIS WILL
STICK AROUND A FEW MORE HOURS...THOUGHT CONDITIONS SHOULD REMAIN VFR
THROUGH THE DAY. THERE IS SOME INDICATION OF WRAP AROUND LOW LEVEL
MOISTURE MOVING IN AROUND 00Z FRI. THINK THIS SHOULD REMAIN ABOVE 3
KFT. MODELS ARE COMING IN WITH A STRONGER PRESSURE GRADIENT.
THEREFORE HAVE INCREASED WINDS AND GUSTS FOR THE DAY THURSDAY.
WOLTERS
&&
.PREV DISCUSSION... /316 PM CST WED FEB 22 2012/
THROUGH THURSDAY...A WARM AFTERNOON WAS UNDERWAY ON WEDNESDAY WITH
HIGHS EXPECTED TO TOP OUT IN THE UPPER 50S TO MIDDLE 60S ACROSS THE
AREA UNDER FAST WEST NORTHWESTERLY FLOW ALOFT AND A WESTERLY BREEZE
AT THE SURFACE. THERE WERE SOME MID AND HIGH CLOUDS IN THE
AREA...WITH MORE AMPLE CLOUD COVER OVER WESTERN NEBRASKA IN ADVANCE
OF AN INCOMING SHORT WAVE TROUGH. IT APPEARS THAT SOME LIGHT PRECIP
MAY SPREAD DOWNSTREAM OUT OF WESTERN NEBRASKA THIS EVENING AS THE
TROUGH ENTERS THE PLAINS...BUT WITH FAIRLY DRY AIR IN THE LOW TO MID
LEVELS IT SHOULD BE DIFFICULT FOR ANYTHING MORE THAN PERHAPS A FEW
SPRINKLES TO FALL ACROSS THE LOCAL FORECAST AREA. TEMPERATURES WILL
STAY QUITE WARM THROUGH THE EVENING AND EARLY MORNING HOURS AS A
BREEZE WILL KEEP THE BOUNDARY LAYER MIXED AND HIGH CLOUDS SHOULD
INSULATE A BIT. HOWEVER...AS THE TROUGH CROSSES THE PLAINS...A
STRONG COLD FRONT WILL MOVE INTO THE AREA AFTER MIDNIGHT AND CROSS
THE ENTIRE FORECAST AREA BY SUNRISE. TEMPERATURES BEHIND THE FRONT
WILL DROP OFF...SO WHILE MOST OF THE NIGHT WILL BE WARM...TEMPS WILL
DROP QUICKLY AS THE FRONT PASSES.
THE POST FRONTAL AIRMASS ON THURSDAY WILL BE A WINDY ONE. EXPECT
DEEP MIXING TO AT LEAST 800 HPA...AND PERHAPS HIGHER BY LATE
AFTERNOON. THIS WILL ALLOW STRONG WINDS TO MIX TO THE SURFACE...
SUPPORTED BY PERIODS OF STRONG DOWNWARD MOTION THROUGH A
UNIDIRECTIONAL WIND FIELD IN THE WAKE OF THE UPPER TROUGH. HAVE
ISSUED A WIND ADVISORY FOR NORTHWESTERN PARTS OF THE FORECAST AREA
WHERE CONFIDENCE IS HIGHEST IN SUSTAINED WINDS GREATER THAN 30 MPH.
THERE IS A BIT OF UNCERTAINTY REGARDING HOW WINDY IT WILL GET ACROSS
THE REMAINDER OF THE AREA...BUT THE POTENTIAL AT LEAST EXISTS FOR
THE ADVISORY TO BE EXPANDED WITH GUST POTENTIAL IN THE 45 TO 50 MPH
RANGE IF FULL MIXING POTENTIAL IS REACHED. THE WAVE IS STRONG...BUT
EXPECT LITTLE MORE THAN A FEW SPRINKLES ON FRIDAY OWING TO DRY AIR.
TEMPS WILL WARM INTO THE UPPER 40S AND LOWER 50S AS THE WARM START
TO THE MORNING AND DEEP MIXING MITIGATES A BIT OF THE COLD
ADVECTION. THE DEEP MIXING AND DRY ADVECTION PRESENTS A DIFFICULT
FIRE WEATHER FORECAST AS WELL. AT THE CURRENT TIME EXPECT MIN RH
VALUES TO APPROACH 30 PERCENT...BUT THAT MAY BE CONSERVATIVE
DEPENDING ON JUST HOW DEEP THE BOUNDARY LAYER MIXES...AND IS ALSO
HIGHLY DEPENDENT ON HIGH TEMPS.
BARJENBRUCH
THURSDAY NIGHT AND FRIDAY...UPPER TROUGH AND ASSOCIATED SURFACE
LOW TRACKS INTO THE MID MISSISSIPPI VALLEY THURSDAY NIGHT. ALL
MODELS HAVE SOME SORT OF WRAPAROUND LIGHT SNOW TO THE NORTH AND
NORTHWEST OF SURFACE LOW AND THIS COULD BRUSH EXTREME NORTHEAST KS
THURSDAY EVENING. HOWEVER...WITH MAIN DYNAMICS AND ISENTROPIC LIFT
TO THE NORTH OF KS...HAVE LITTLE CONFIDENCE OF ANYTHING REALLY
FALLING OUT OF THE SKY DURING THAT BRIEF WINDOW. NORTHEAST FLOW
CONTINUES TRANSPORTING COOL AIR INTO EASTERN KS ON FRIDAY WITH HIGHS
ONLY IN THE LOWER TO MID 40S.
SURFACE HIGH PRESSURE RIDGE THEN MOVES ACROSS THE PLAINS FRIDAY
NIGHT WITH CLEAR SKIES EXPECTED. AS THE RIDGE TRAVERSES EAST ON
FRIDAY NIGHT AND SATURDAY...LOW PRESSURE DEVELOPS IN THE NORTHERN
AND CENTRAL HIGH PLAINS AS STRONG MID AND UPPER JET IMPINGES ON
THE ROCKIES. SIGNIFICANT PRESSURE GRADIENT SETS UP BETWEEN THESE
WEATHER SYSTEMS AND THIS SHOULD WARM TEMPS UP ON SATURDAY WITH
STRONG SOUTHERLY WINDS. MIXING WILL ALSO KEEP TEMPERATURES
RELATIVELY MILD SATURDAY NIGHT...IN THE MID TO UPPER 30S.
UPPER TROUGH AND INTENSE LOW THEN MOVE INTO THE UPPER MIDWEST
SUNDAY. ALL LONG RANGE MODELS KEEP STRONGEST LIFT WELL TO NORTH OF
EASTERN KS AND HAVE KEPT SUNDAY DRY AS A RESULT. 12Z GEM AND ECMWF
ATTEMPT TO DEVELOP SHOWERS ALONG TRAILING COLD FRONT IN EC KS
SUNDAY EVENING. THEN RIDGE OF HIGH PRESSURE PUSHES INTO THE AREA
FROM THE NORTHWEST FOR LATE SUNDAY NIGHT AND MONDAY.
DETAILS THEN GET FUZZY ON MONDAY NIGHT AND TUESDAY INTO TUESDAY
NIGHT. LAST COUPLE RUNS OF GFS AND ECMWF BRING SYSTEM ACROSS DURING
THAT TIME FRAME...BUT DIFFER IN ONSET TIMING AND LOCATION OF WARM
SECTOR. MORE NORTHERN AND INTENSE 12Z GFS WOULD GIVE CHANCE OF
THUNDERSTORMS AND MUCH HIGHER TEMPERATURES TUESDAY WHEREAS LATEST
ECMWF KEEPS LOW WELL TO SOUTH AND SNOW MORE LIKELY. HAVE GONE WITH
A COMPROMISE AT THIS TIME. WOULD EXPECT MODELS TO BECOME MORE
CONSISTENT WITH EACH OTHER ON THIS SYSTEM WHEN UPPER JET/TROUGH
MAKES IT TO THE COAST THIS WEEKEND AND GETS SAMPLED.
RIGHT NOW THE TIMING OF THAT SYSTEM WOULD KEEP THE DAYTIME HOURS ON
WEDNESDAY DRY...AND HAVE GONE WITH THAT SCENARIO.
PHILLIPS
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
933 PM EST FRI FEB 24 2012
.SYNOPSIS...
LOW PRESSURE WILL INTENSIFY AS IT TRACKS THROUGH THE GULF OF MAINE
TONIGHT. 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 SATURDAY/...
UPDATE2: 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.
UPDATE1: 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.
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 TIMEFRAME 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 TIMEFRAME.
&&
.SHORT TERM /SATURDAY NIGHT 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 FRIDAY/...
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 /03Z 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
TIMEFRAME 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 SATURDAY FOR MEZ001>004.
WINTER STORM WARNING UNTIL 10 AM EST SATURDAY FOR MEZ005-006-
010-011-031-032.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
MEZ015>017.
WIND ADVISORY UNTIL 3 PM EST SATURDAY FOR MEZ029-030.
MARINE...GALE WARNING UNTIL 5 PM EST SUNDAY FOR ANZ050>052.
&&
$$
NEAR TERM...FOSTER/HEWITT
SHORT TERM...BLOOMER
LONG TERM...NORTON
AVIATION...FOSTER/HEWITT
MARINE...FOSTER/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
604 PM EST FRI FEB 24 2012
.SYNOPSIS...
LOW PRESSURE WILL INTENSIFY AS IT TRACKS THROUGH THE GULF OF MAINE
TONIGHT. 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 SATURDAY/...
UPDATE: 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.
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 TIMEFRAME 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 TIMEFRAME.
&&
.SHORT TERM /SATURDAY NIGHT 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 FRIDAY/...
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 /22Z FRIDAY 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
TIMEFRAME 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 FROM 10 PM THIS EVENING TO NOON EST
SATURDAY FOR MEZ001>004.
WINTER STORM WARNING UNTIL 10 AM EST SATURDAY FOR MEZ005-006-
010-011-031-032.
WINTER WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR
MEZ015>017.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 3 PM EST SATURDAY FOR
MEZ029-030.
MARINE...GALE WARNING FROM MIDNIGHT TONIGHT TO 5 PM EST SUNDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...FOSTER/HEWITT
SHORT TERM...BLOOMER
LONG TERM...NORTON
AVIATION...FOSTER/HEWITT
MARINE...FOSTER/HEWITT/BLOOMER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
655 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.
&&
.NEAR TERM /THROUGH SATURDAY/...
PER RECENT SURFACE DATA AND RECENT HRRR AND NAM MODEL OUTPUT,
EXPECT WIND GUSTS TO STILL BE IN THE 40-45 MPH RANGE EARLY TONIGHT,
THEN SUBSIDE INTO THE 30-35 MPH RANGE LATE TONIGHT. HENCE WILL
EXTEND THE HIGH WIND HEADLINES PAST THEIR EXPIRATION TIME. THE
LATEST WIND AND DAMAGE REPORTS CAN BE FOUND UNDER A PUBLIC
INFORMATION STATEMENT AND/OR LOCAL STORM REPORT HEADER.
NAM MODEL PROFILES SHOW A SUFFICIENTLY THICK UNSTABLE SURFACE
LAYER FOR LAKE-EFFECT SNOW SHOWERS ACROSS THE UPPER OHIO VALLEY
TONIGHT AND SATURDAY. THE MOST PERSISTENT WILL BE ACROSS THE NORTH
AND OVER THE MOUNTAINS, WHERE SNOW ACCUMULATIONS CAN GO OVER 3
INCHES, AND BE ACCOMPANIED BY BLOWING SNOW. MOST OTHER LOCATIONS WILL
GET NO MORE THAN AN INCH.
HAVE TWEAKED EXPECTED SHARP TEMPERATURE DROP TONIGHT USING RECENT
HRRR AND NAM MODEL OUTPUT AND GFS LAMP. THIS YIELDED LOW
TEMPERATURES SIMILAR TO GFS AND NAM MOS VALUES.
&&
.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 /00Z 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...HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ001.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 6 PM EST
SATURDAY FOR MDZ001.
OH...NONE.
PA...LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 4 PM EST
SATURDAY FOR PAZ007>009.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ007>009-
013>016-020>023-029-031-073-075.
HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ074-076.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 6 PM EST
SATURDAY FOR PAZ074-076.
WV...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR WVZ021-022.
HIGH WIND WARNING UNTIL 10 PM EST THIS EVENING FOR WVZ023-041.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 6 PM EST
SATURDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
601 PM EST THU FEB 23 2012
.SYNOPSIS...
ISSUED AT 415 PM EST THU FEB 23 2012
A STRONG WINTER STORM WILL MOVE THROUGH THE LOWER GREAT LAKES
TONIGHT INTO FRIDAY. HEAVY SNOWFALL IS EXPECTED LATER TONIGHT INTO
FRIDAY MORNING. LAKE EFFECT SNOW SHOWERS WILL FOLLOW FRIDAY
AFTERNOON INTO SATURDAY AFTERNOON. HIGH PRESSURE WILL CLEAR THE
SKIES FOR SUNDAY BEFORE ANOTHER SYSTEM MOVES ACROSS THE AREA WITH
WARMER TEMPERATURES MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EST THU FEB 23 2012
THE PRIMARY ISSUE IS THE WINTER STORM HEADING TOWARD THE SOUTHERN
GREAT LAKES FOR LATER TONIGHT INTO FRIDAY. THERE IS ALSO AN ISSUE
WITH LAKE EFFECT SNOW FRIDAY AFTERNOON INTO SATURDAY.
MY CURRENT THINKING IS THERE WILL BE SNOW...HEAVY AT TIMES LATE
THIS EVENING INTO MID MORNING FRIDAY. A FEW FLASHES OF LIGHTNING
ARE NOT OUT OF THE QUESTION TONIGHT EITHER. THE HEAVIEST SNOWFALL
WILL BE NEAR AND SOUTH OF INTERSTATE 96.
THERE HAS BEEN A CURIOUS SHIFT IN THE MODELS OVER THE PAST 12
HOURS WITH THE TIMING OF THE SYSTEM. MY EARLIER THINKING BROUGHT
THE HEAVY SNOW INTO THE AREA AFTER MIDNIGHT AND ENDED IT BY MID
MORNING. HOWEVER THE 18Z NAM... THE 16Z HRRR AND 12Z ECMWF SUGGEST
THE HEAVIEST SNOWFALL MAY WELL BE MOSTLY DURING THE DAY FRIDAY.
WHAT SEEMS TO BE HAPPENING IS THE WARM ADVECTION BURST OF
PRECIPITATION WILL LARGELY TRACK EAST NORTHEAST NEAR AND SOUTH OF
INTERSTATE 94 TONIGHT. THEN THE DEFORMATION BAND WITH THE UPPER
LOW IS WHAT WILL BRING THE HEAVY SNOW TO THE CENTRAL PARTS OF THE
CWA. WITH THIS LATEST THINKING THE HEAVIEST SNOW WOULD BE FROM 05
AM THROUGH 1 PM INSTEAD OF 9 PM TILL 7 AM AS EARLIER THROUGH.
THE DEEP UPPER LOW OF COURSE MEANS STRONGER FORCING...BETTER
FGEN... AND INCREASED NEG EPV. THUS OUR IDEA OF HEAVY SNOW STILL
LOOKS GOOD...MAYBE EVEN BETTER BUT JUST SLOWER. I ADDED THUNDER
DUE TO THE NEG EPV...STRONG FGEN AND THE TQ INDEX BEING OVER 15
(SUGGEST ELEVATED THUNDERSTORMS). ALSO SUPPORTING HEAVY SNOW IS
STRONG LIFT IN THE DGZ. ONLY ISSUE THERE IS THE DGZ IS ABOVE 10000
FT AGL AND IT NARROW. ON THE OTHER HAND THE DGZ DOES FALL TO BELOW
1000O FT AFTER 06Z AND GETS DEEPER. THERE IS ANOTHER AREA OF
ENHANCED LIFT IN THE DGZ TOWARD 12Z. ALL OF THIS SUPPORTS THE IDEA
OF ENHANCED SNOWFALL ACROSS THE CENTRAL CWA WITH THIS SYSTEM.
THE ECMWF 12Z AND 18Z NAM HAVE INCREASED THE QPF (WHILE DELAYING
TIMING 6 TO 12 HOURS). SO THE BOTTOM LINE IS MIXED RAIN AND SNOW
THIS EVENING OVER THE SOUTHERN 1/3 OF THE CWA. THEN SNOW SPREADING
NORTH AND EAST AFTER MIDNIGHT WITH SNOW HEAVY AT TIMES CENTRAL CWA
FRIDAY MORNING. WE ARE EXPECTING 6 TO 10 INCHES IN THE HEAVIEST
SNOW AREA.
AFTER THE UPPER UPPER LOW MOVES EAST OF THE AREA FRIDAY
AFTERNOON... THAT ALLOWS THE BETTER COLD ADVECTION TO BEGIN. WITH
CYCLONIC FLOW... 850 MB TMPS BELOW -10C MOVING IN WITH DEEP
MOISTURE ON NORTHWEST WINDS... LAKE EFFECT SNOW DEVELOPS AND
CONTINUES THROUGH THE NIGHT. THE BEST SNOWFALL FOR THIS WILL BE
DURING THE OVERNIGHT HOURS. ANOTHER 2 TO 4 INCHES ARE EXPECTED
WITH THAT IN THE TYPICAL NW FLOW AREAS. THIS TIME THROUGH THE AIR
TEMP WILL BE BELOW FREEZING SO THIS SNOW WILL BE MORE OF A FLUFFY
SNOW. ONCE AGAIN THERE IS GOOD LIFT IN THE DGZ BUT THE BEST LIFT
IS ACTUALLY BELOW THE DGZ SO THIS WILL NOT BE AS FLUFFY AS SOME
LAKE EFFECT EVENTS HAVE BEEN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 415 PM EST THU FEB 23 2012
LINGERING LAKE EFFECT SNOW SHOWERS SATURDAY MORNING WILL END IN THE
AFTERNOON AS UPPER LEVEL FLOW BECOMES ANTICYCLONIC. DRY WEATHER IS
FORECAST SATURDAY NIGHT AND SUNDAY WITH UPPER RIDGING IN PLACE.
AT THIS TIME WE WILL MAINTAIN VERY LOW POPS FOR SUNDAY NIGHT INTO
MONDAY AS WEAK LOW PRESSURE MOVES ACROSS THE LAKE SUPERIOR REGION.
HOWEVER IT IS NOTED THAT OVERALL MEDIUM RANGE GUIDANCE TRENDS KEEP
LIGHT QPF TIED TO THIS SYSTEM NORTH OF OUR FCST AREA... SO FUTURE
SHIFTS MAY BE ABLE TO GO WITH A DRY FCST SUNDAY NIGHT/MONDAY.
A BETTER CHC FOR PCPN SHOULD COME FOR THE MIDDLE PORTION OF NEXT
WEEK AS A SOUTHERN PLAINS LOW TRACKS ENE INTO THE LOWER GREAT LAKES
REGION BY TUESDAY NIGHT/WEDNESDAY. LIGHT PCPN MAY ARRIVE AS EARLY AS
TUESDAY PRECEDING THAT SYSTEM... BUT THE BETTER CHC FOR PCPN SHOULD
HOLD OFF UNTIL TUESDAY NIGHT AND WEDNESDAY AS SUGGESTED BY 12Z ECMWF
GUIDANCE.
TRENDED THE MAX TEMP FCST A BIT MILDER FOR WEDNESDAY WITH POTENTIAL
FOR A RAIN/SNOW MIX. TEMPS SHOULD AVG NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE LONG RANGE FCST PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 600 PM EST THU FEB 23 2012
MAIN CHANGES TO THIS UPDATE WERE TO DELAY TIMING OF RAIN AND SNOW
AND TO INCREASE NORTHEAST WINDS OVERNIGHT. WE STILL EXPECT LIFR
CONDITIONS AREAWIDE RELATED TO MODERATE/HEAVY SNOW AND INCREASING
WINDS. THUNDER COULD EVEN ACCOMPANY PRECIPITATION AT THE
KAZO...KBTL...KJXN TERMINALS ALONG THE I-94 CORRIDOR. A BRIEF
PERIOD OF FREEZING RAIN IS POSSIBLE DURING THE CHANGEOVER...BUT WE
DO NOT EXPECT SIGNIFICANT ICING OVERALL. THIS LOOKS LIKE A PROLONGED
EVENT...SO KEPT IFR CONDITIONS AFTER 12Z.
&&
.MARINE...
ISSUED AT 415 PM EST THU FEB 23 2012
I HAVE ISSUED A SMALL CRAFT ADVISORY DUE TO THE INCREASING NORTH
WINDS TONIGHT THROUGH SATURDAY AFTERNOON. WINDS SHOULD INCREASE TO
15 TO 25 KNOTS OVERNIGHT AND CONTINUE INTO SATURDAY BEFORE
DIMINISHING DURING THE LATE AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 415 PM EST THU FEB 23 2012
THERE ARE NO WARNINGS OR ADVIOSRIES IN EFFECT FOR AREA RIVERS OR
STREAMS. TEMPERATURES ARE NOT EXPECTED TO GET COLD ENOUGH FOR ICE
JAMS TO BE AN ISSUE. METLING OF THE SNOW THAT FALLS SHOULD BE SLOW
ENOUGH TO NOT BE MUCH OF AN ISSUE EITHER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING UNTIL NOON EST FRIDAY FOR MIZ056>059-
064>067-071>074.
WINTER WEATHER ADVISORY UNTIL NOON EST FRIDAY FOR MIZ044>046-
050>052.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SATURDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM....LAURENS
AVIATION...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
425 PM EST THU FEB 23 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM EST THU FEB 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM MANITOBA AND NRN ONTARIO INTO THE SRN PLAINS. A VIGOROUS
SHORTWAVE TROUGH MOVING THROUGH SRN NEBRASKA SUPPORTED A BAND OF
MODERATE TO HEAVY SNOW OVER SE SD INTO NRN IA AND RAIN TO THE EAST.
AN UPSTREAM SHRTWV NEAR LAKE WINNIPEG WAS BRINGING MAINLY JUST LIGHT
SNOW OR FLURRIES IN SRN MANITOBA AND NW ONTARIO. AT THE SFC...A 990
MB LOW WAS LOCATED OVER SE MO WHILE A WEAKER 1002 MB LOW MOVING
THROUGH SE MANITOBA. A WEAK TROUGH EXTENDED FROM WEST TO EAST ACROSS
UPPER MI LEAVING VERY LIGHT WINDS OVER THE AREA. WITH PLENTY OF LOW
LEVEL MOISTURE IN PLACE THE WEAK NNE FLOW COMBINED WITH 850 MB TEMPS
AROUND -9C WAS ENOUGH TO SUPPORT SOME LIGHT SNOW SHOWERS INTO N
CNTRL UPPER MI.
EXPECT AREAS OF LIGHT SNOW SHOWERS OR FLURRIES TO PERSIST INTO THIS
EVENING CNTRL AND WEST WITH THE TROUGH OVER THE AREA AND WEAK FLOW
OFF OF LAKE SUPERIOR. ANY ACCUMULATIONS SHOULD ONLY AMOUNT TO A
TRACE OR A FEW TENTHS. AS THE MANITOBA SHRTWV MOVES TOWARD THE AREA
LATE TONIGHT INTO FRIDAY...MID LEVEL QVECTOR CONV ASSOCIATED WITH
THIS FEATURES WILL SUPPORT AN EXPANDING AREA OF LIGHT SNOW FROM NE
MN INTO WRN LAKE SUPERIOR AND WEST UPPER MI. SINCE THE NNW WINDS LOW
LEVEL WINDS FCST REMAIN RELATIVELY LIGHT THERE IS STILL SIGNIFICANT
UNCERTAINTY REGARDING THE LAKE ENHANCED SNOW POTENTIAL INTO WEST
UPPER MI AS THE HIGH RES MODELS SHOW DIFFERING SCENARIOS. THE BEST
CHANCE FOR SNOW OVER THE WEST IS EXPECTED DURING THE AFTERNOON AS
THE SHORTWAVE APPROACHES AND COLDER AIR MOVES IN WITH 850 MB TEMPS
DROP TO NEAR -12C. IF STRONGER LOW LEVEL CONV OR ONSHORE WINDS
DEVELOP SNOW AMOUNTS OF A COUPLE INCHES WILL BE POSSIBLE BY EVENING.
SCT -SHSN SHOULD ALSO DEVELOP OVER THE REST OF NRN UPPER MI AS NRLY
WINDS INCREASE. HOWEVER...SINCE THE DEEPER MOISTURE REMAINS TO THE
WEST...ONLY CHANCE POPS WERE INCLUDED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM EST THU FEB 23 2012
FRI NGT...A CYC NLY FLOW WL DOMINATE THE UPR GRT LKS AS A SHRTWV
DIGGING SEWD THRU MN MAINTAINS LOWER HGTS/HIER MID LVL RH OVER THE
UPR LKS. ALTHOUGH THE FCST H85 TEMPS IN THE -12C TO -14C ARE NOT
PARTICULARLY COLD...OPTED TO MAINTAIN LIKELY POPS IN AREAS FAVORED
BY THE NNW LLVL FLOW GIVEN THE DEEP MSTR PROFILE. WENT WITH THE
HIER POPS OVER THE W CLOSER TO THE TRACK OF THE MN DISTURBANCE.
SAT...EXPECT LINGERING LES IN THE MRNG TO DIMINISH WITH THE APRCH OF
SHRTWV RDG IN PROGRESSIVE FLOW ALF AND ARRIVAL OF RISING H5 UP TO
100M BTWN 12Z-24Z/SFC HI PRES IN THE WAKE OF DEPARTING SHRTWV.
ALTHOUGH FCST LLVL NW FLOW IS FAVORABLE FOR LES IN AREAS E OF MQT...
MODELS CONSISTENTLY SHOW DRY AIR IN ONTARIO PASSING OVER ERN LK SUP
AND LIMITING SN CHCS OVER THE ERN CWA. SO CUT POPS/SN AMOUNTS SHOWN
IN PREVIOUS FCSDT.
SAT NGT...ALTHOUGH A FEW -SHSN MAY LINGER NEAR LK SUP IN THE EVNG...
BACKING FLOW TO THE SSW OVERNGT WITH PASSAGE OF RDG AXIS TO THE E
AND APRCH OF STRONG SHRTWV/SFC LO THRU THE NRN PLAINS WL PUSH ANY
REMAINING -SHSN OUT INTO THE OPEN LAKE. WITH SOME CLRG/LGT WINDS
UNDER THE RDG AXIS/PWAT ARND 0.15 INCH...TEMPS OVER THE INTERIOR MAY
FALL SHARPLY IN THE EVNG BEFORE THICKENING HI/MID CLDS RETURN LATE
WITH DVLPG ISENTROPIC ASCENT AHEAD OF THE INCOMING SHRTWV/SFC LO AND
CAUSE READINGS TO RISE LATER. TENDED TOWARD THE LO END OF GUIDANCE
FOR MIN TEMPS IN THIS AREA WITH A NON DIURNAL TEMP TREND.
SUN/SUN NGT...MODELS HAVE TRENDED A BIT FASTER WITH THE INCOMING
FCST LO PRES AS SUPPORTING SHRTWV IS FCST TO SHEAR OUT AS IT MOVES
INTO CONFLUENCE ZN BTWN MEAN RDG OVER THE SE CONUS AND PERSISTENT
WNW FLOW ALF OVER NE CAN ON SW FLANK OF CLOSED LO NEAR THE DAVIS
STRAIT. ALTHOUGH THE 12Z GFS SHOWS A MORE SHEARED OUT/WEAKER
DISTURBANCE WHILE THE CNDN MODEL DEPICTS A DEEPER SYS...VARIOUS
GUIDANCE IS IN GOOD AGREEMENT SHOWING THE LO PRES TRACK ACRS THE NRN
TIER OF THE CWA/SRN LK SUP. THIS TRACK SHOULD MINIMIZE THE THREAT OF
SGNFT SN ACCUM OVER THE FA WITH MORE PERSISTENT DEEPER FGEN UNDER
DEFORMATION ZN PASSING TO THE W AND N AND POTENTIAL DRY SLOTTING
ESPECIALL OVER THE SRN TIER CLOSER TO SUPPORTING JET CORE AXIS.
HOWEVER...COMBINATION OF FAIRLY SHARP UPR DVGC IN LEFT EXIT OF
SUPPORTING H3 JET MAX/FAIRLY VIGOROUS ISENTROPIC ASCENT SHOWN ON THE
285K SFC /ABOUT H75/ IN THE WAD PATTERN N OF ATTENDANT WARM FNT/DEEP
LYR QVECTOR CNVGC WARRANT FCST HI LIKELY POPS SPREADING IN BY AFTN.
GIVEN FCST H7 SPECIFIC HUMIDITY OF 2 G/KG...SUSPECT UP TO 2 TO 4
INCHES OF SN MAY FALL OVER THE NW CWA ON SUN...ESPECIALLY SINCE GFS
FCST SDNGS SHOW SHARP OMEGA WITHIN THE DGZ IN THAT AREA. EXPECT THE
SYNOPTIC SCALE PCPN TO DIMINISH TO LES W-E BY EARLY MON MORNING
WITH LARGE SCALE QVECTOR DVGC/DRYING FOLLOWING THE SHRTWV/SFC LO.
SINCE THERE IS A POTENTIAL FOR ADVY SN WITH THIS DISTURBANCE...OPTED
TO RETAIN MENTION IN HWO.
IN THE EXTENDED RANGE...SOME LES IS LIKELY ON MON UNDER THE MOIST
NNW FLOW LEFT IN THE WAKE OF THE DEPARTING LO THRU SE CAN AND WITH
H85 TEMPS PROGGED TO DIP AS LO AS -15C. THE ARRIVAL OF A HI PRES RDG
WL BRING QUIET WX ON TUE. ANOTHER DISTURBANCE/SFC LO MOVING IS FCST
TO MOVE THRU THE OH VALLEY ON WED. THERE HAS BEEN CONSIDERABLE MODEL
DISAGREEMENT ON THE TRACK OF THIS SHRTWV...SO RELIED ON THE
CONSENSUS OF THE MODELS FOR THE FORECAST IN THAT PERIOD. BEST SHOT
FOR ANY ACCOMPANYING SN WL BE OVER THE S. WITH HI PRES FOLLOWING
THIS SYSTEM NEXT THU...EXPECT A DRYING TREND THEN. SINCE THE
PREVAILING ZONAL FLOW ALF THRU THE EXTENDED PERIOD WL LIMIT ARCTIC
AIR INTRUSION INTO THE CONUS...EXPECT ABV NORMAL TEMPS TO PERSIST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM EST THU FEB 23 2012
LIGHT NORTHERLY WINDS ARE EXPECTED THROUGH THE FCST PERIOD AS A WEAK
INVERTED TROUGH REMAINS TO THE WEST AND LOW PRES MOVES NORTHEAST
FROM MISSOURI TO THE LOWER GREAT LAKES. MOIST LOW LEVELS WILL KEEP
CONDITIONS MVFR AT ALL TAF SITES THROUGH THE FCST PERIOD AND COULD
CAUSE SOME UPSLOPE FLURRIES AT THE TAF SITES BUT WITH NO RESTRICTION
IN VSBY. LATE TONIGHT...COLDER AIR WILL ARRIVE AND LAKE EFFECT SNOW
SHOWERS WILL INCREASE AT KCMX AND KIWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EST THU FEB 23 2012
NRLY WINDS INCREASING INTO THE 15 TO 25 KT RANGE ARE EXPECTED LATE
FRIDAY INTO FRIDAY NIGHT AS THE GRADIENT INCREASES IN THE WAKE OF
LOW PRESSURE MOVING TOWARD THE SRN GREAT LAKES. A LOW PRESSURE
SYSTEM MOVING THROUGH THE UPPER GREAT LAKES SUNDAY INTO MONDAY WILL
ALSO BRING A PERIOD OF STRONGER WINDS. SE WINDS TO 30 KT ARE
EXPECTED IN ADVANCE OF THE LOW ON SUN. AS THE LOW MOVES TO THE EAST
OF THE AREA MONDAY NORTH TO NORTHWEST WINDS OF 20 TO 30 KT ARE ALSO
EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
416 PM EST THU FEB 23 2012
.SYNOPSIS...
ISSUED AT 415 PM EST THU FEB 23 2012
A STRONG WINTER STORM WILL MOVE THROUGH THE LOWER GREAT LAKES
TONIGHT INTO FRIDAY. HEAVY SNOWFALL IS EXPECTED LATER TONIGHT INTO
FRIDAY MORNING. LAKE EFFECT SNOW SHOWERS WILL FOLLOW FRIDAY
AFTERNOON INTO SATURDAY AFTERNOON. HIGH PRESSURE WILL CLEAR THE
SKIES FOR SUNDAY BEFORE ANOTHER SYSTEM MOVES ACROSS THE AREA WITH
WARMER TEMPERATURES MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 415 PM EST THU FEB 23 2012
THE PRIMARY ISSUE IS THE WINTER STORM HEADING TOWARD THE SOUTHERN
GREAT LAKES FOR LATER TONIGHT INTO FRIDAY. THERE IS ALSO AN ISSUE
WITH LAKE EFFECT SNOW FRIDAY AFTERNOON INTO SATURDAY.
MY CURRENT THINKING IS THERE WILL BE SNOW...HEAVY AT TIMES LATE
THIS EVENING INTO MID MORNING FRIDAY. A FEW FLASHES OF LIGHTNING
ARE NOT OUT OF THE QUESTION TONIGHT EITHER. THE HEAVIEST SNOWFALL
WILL BE NEAR AND SOUTH OF INTERSTATE 96.
THERE HAS BEEN A CURIOUS SHIFT IN THE MODELS OVER THE PAST 12
HOURS WITH THE TIMING OF THE SYSTEM. MY EARLIER THINKING BROUGHT
THE HEAVY SNOW INTO THE AREA AFTER MIDNIGHT AND ENDED IT BY MID
MORNING. HOWEVER THE 18Z NAM... THE 16Z HRRR AND 12Z ECMWF SUGGEST
THE HEAVIEST SNOWFALL MAY WELL BE MOSTLY DURING THE DAY FRIDAY.
WHAT SEEMS TO BE HAPPENING IS THE WARM ADVECTION BURST OF
PRECIPITATION WILL LARGELY TRACK EAST NORTHEAST NEAR AND SOUTH OF
INTERSTATE 94 TONIGHT. THEN THE DEFORMATION BAND WITH THE UPPER
LOW IS WHAT WILL BRING THE HEAVY SNOW TO THE CENTRAL PARTS OF THE
CWA. WITH THIS LATEST THINKING THE HEAVIEST SNOW WOULD BE FROM 05
AM THROUGH 1 PM INSTEAD OF 9 PM TILL 7 AM AS EARLIER THROUGH.
THE DEEP UPPER LOW OF COURSE MEANS STRONGER FORCING...BETTER
FGEN... AND INCREASED NEG EPV. THUS OUR IDEA OF HEAVY SNOW STILL
LOOKS GOOD...MAYBE EVEN BETTER BUT JUST SLOWER. I ADDED THUNDER
DUE TO THE NEG EPV...STRONG FGEN AND THE TQ INDEX BEING OVER 15
(SUGGEST ELEVATED THUNDERSTORMS). ALSO SUPPORTING HEAVY SNOW IS
STRONG LIFT IN THE DGZ. ONLY ISSUE THERE IS THE DGZ IS ABOVE 10000
FT AGL AND IT NARROW. ON THE OTHER HAND THE DGZ DOES FALL TO BELOW
1000O FT AFTER 06Z AND GETS DEEPER. THERE IS ANOTHER AREA OF
ENHANCED LIFT IN THE DGZ TOWARD 12Z. ALL OF THIS SUPPORTS THE IDEA
OF ENHANCED SNOWFALL ACROSS THE CENTRAL CWA WITH THIS SYSTEM.
THE ECMWF 12Z AND 18Z NAM HAVE INCREASED THE QPF (WHILE DELAYING
TIMING 6 TO 12 HOURS). SO THE BOTTOM LINE IS MIXED RAIN AND SNOW
THIS EVENING OVER THE SOUTHERN 1/3 OF THE CWA. THEN SNOW SPREADING
NORTH AND EAST AFTER MIDNIGHT WITH SNOW HEAVY AT TIMES CENTRAL CWA
FRIDAY MORNING. WE ARE EXPECTING 6 TO 10 INCHES IN THE HEAVIEST
SNOW AREA.
AFTER THE UPPER UPPER LOW MOVES EAST OF THE AREA FRIDAY
AFTERNOON... THAT ALLOWS THE BETTER COLD ADVECTION TO BEGIN. WITH
CYCLONIC FLOW... 850 MB TMPS BELOW -10C MOVING IN WITH DEEP
MOISTURE ON NORTHWEST WINDS... LAKE EFFECT SNOW DEVELOPS AND
CONTINUES THROUGH THE NIGHT. THE BEST SNOWFALL FOR THIS WILL BE
DURING THE OVERNIGHT HOURS. ANOTHER 2 TO 4 INCHES ARE EXPECTED
WITH THAT IN THE TYPICAL NW FLOW AREAS. THIS TIME THROUGH THE AIR
TEMP WILL BE BELOW FREEZING SO THIS SNOW WILL BE MORE OF A FLUFFY
SNOW. ONCE AGAIN THERE IS GOOD LIFT IN THE DGZ BUT THE BEST LIFT
IS ACTUALLY BELOW THE DGZ SO THIS WILL NOT BE AS FLUFFY AS SOME
LAKE EFFECT EVENTS HAVE BEEN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 415 PM EST THU FEB 23 2012
LINGERING LAKE EFFECT SNOW SHOWERS SATURDAY MORNING WILL END IN THE
AFTERNOON AS UPPER LEVEL FLOW BECOMES ANTICYCLONIC. DRY WEATHER IS
FORECAST SATURDAY NIGHT AND SUNDAY WITH UPPER RIDGING IN PLACE.
AT THIS TIME WE WILL MAINTAIN VERY LOW POPS FOR SUNDAY NIGHT INTO
MONDAY AS WEAK LOW PRESSURE MOVES ACROSS THE LAKE SUPERIOR REGION.
HOWEVER IT IS NOTED THAT OVERALL MEDIUM RANGE GUIDANCE TRENDS KEEP
LIGHT QPF TIED TO THIS SYSTEM NORTH OF OUR FCST AREA... SO FUTURE
SHIFTS MAY BE ABLE TO GO WITH A DRY FCST SUNDAY NIGHT/MONDAY.
A BETTER CHC FOR PCPN SHOULD COME FOR THE MIDDLE PORTION OF NEXT
WEEK AS A SOUTHERN PLAINS LOW TRACKS ENE INTO THE LOWER GREAT LAKES
REGION BY TUESDAY NIGHT/WEDNESDAY. LIGHT PCPN MAY ARRIVE AS EARLY AS
TUESDAY PRECEDING THAT SYSTEM... BUT THE BETTER CHC FOR PCPN SHOULD
HOLD OFF UNTIL TUESDAY NIGHT AND WEDNESDAY AS SUGGESTED BY 12Z ECMWF
GUIDANCE.
TRENDED THE MAX TEMP FCST A BIT MILDER FOR WEDNESDAY WITH POTENTIAL
FOR A RAIN/SNOW MIX. TEMPS SHOULD AVG NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE LONG RANGE FCST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1230 PM EST THU FEB 23 2012
CONDITIONS HAVE IMPROVED TO MVFR TO VFR AT SOME OF THE TERMINALS
EARLY THIS AFTERNOON WHERE FOG HAS DISSIPATED... BUT SOME PATCHY IFR
TO LIFR REMAINS AT KAZO AND KBTL DUE TO LOW CLOUDS AND FOG. EXPECT
VARIABLE CONDITIONS TO CONTINUE THIS AFTN DUE TO PATCHY FOG.
CONDITIONS WILL DETERIORATE RAPIDLY FROM IFR TO LIFR THEN VLIFR FROM
SOUTH TO NORTH MID TO LATE EVENING AS HEAVY SNOW DEVELOPS. LIFR TO
MAINLY VLIFR CONDITIONS OVERNIGHT WILL GRADUALLY IMPROVE TO IFR MID
TO LATE FRIDAY MORNING AS SNOW DECREASES IN INTENSITY. EAST WINDS
THIS AFTN WILL BACK TO THE NE OVERNIGHT THEN BACK TO THE NNW AND
RAMP UP FRIDAY MORNING AND EARLY AFTN.
&&
.MARINE...
ISSUED AT 415 PM EST THU FEB 23 2012
I HAVE ISSUED A SMALL CRAFT ADVISORY DUE TO THE INCREASING NORTH
WINDS TONIGHT THROUGH SATURDAY AFTERNOON. WINDS SHOULD INCREASE TO
15 TO 25 KNOTS OVERNIGHT AND CONTINUE INTO SATURDAY BEFORE
DIMINISHING DURING THE LATE AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 415 PM EST THU FEB 23 2012
THERE ARE NO WARNINGS OR ADVIOSRIES IN EFFECT FOR AREA RIVERS OR
STREAMS. TEMPERATURES ARE NOT EXPECTED TO GET COLD ENOUGH FOR ICE
JAMS TO BE AN ISSUE. METLING OF THE SNOW THAT FALLS SHOULD BE SLOW
ENOUGH TO NOT BE MUCH OF AN ISSUE EITHER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO NOON EST FRIDAY
FOR MIZ056>059-064>067-071>074.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO NOON EST
FRIDAY FOR MIZ044>046-050>052.
LM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST SATURDAY
FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM....LAURENS
AVIATION...LAURENS
MARINE...WDM
HYDROLOGY...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
327 AM EST THU FEB 23 2012
.UPDATE...
ISSUED AT 327 AM EST THU FEB 23 2012
WILL BE MAINTAINING THE WATCH FOR ALL COUNTIES FOR LATE THIS
AFTERNOON INTO TONIGHT. MORE DETAILS SHORTLY.
&&
.SYNOPSIS...
ISSUED AT 1045 PM EST WED FEB 22 2012
AFTER MOSTLY LIGHT PRECIPITATION MOVES THROUGH THE AREA OVERNIGHT...
HIGH
PRESSURE WILL BRING CLEARING CONDITIONS TO THE AREA THURSDAY
MORNING. A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL APPROACH
THE AREA DURING THE DAY THURSDAY...BRINGING A PERIOD OF
SIGNIFICANT SNOWFALL TO THE AREA THURSDAY NIGHT. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EST WED FEB 22 2012
BRIEFLY SAW IFR VISIBILITY AT KGRR WITH LARGE SNOWFLAKES FALLING.
THE ASSOCIATED AREA OF HEAVIER PRECIPITATION MOVING EAST TOWARDS
KLAN SHOULD BE PREDOMINANTLY SNOW AND BRING...BRIEF IFR VSBYS
THERE TOO. ELSEWHERE...DO NOT EXPECT SUCH DRASTIC RESTRICTIONS. KJXN
IS THE TYPICAL EXCEPTION WITH LIFR CIGS ALREADY BEING REPORTED...
AND EXPECT THIS TO CONTINUE. AS IS ALREADY SEEN AT KMKG...WE
SHOULD SEE A FAIRLY QUICK TRANSITION TO MVFR/VFR CONDITIONS BY 12Z
AT MOST TERMINALS.
&&
.MARINE...
ISSUED AT 1045 PM EST WED FEB 22 2012
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO EXPIRE. WINDS AND WAVES
WILL CONTINUE A RAPID DOWNWARD TREND.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH LATE THIS AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...NONE.
&&
$$
UPDATE...JK
SYNOPSIS...TJT
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1203 AM EST THU FEB 23 2012
.UPDATE...
ISSUED AT 1047 PM EST WED FEB 22 2012
HAVE UPDATED FORECASTS TO REFLECT LESS SNOWFALL ACCUMULATION OVERNIGHT.
PRECIPITATION HAS SPREAD INTO SW LOWER MI AND RECENTLY CHANGED
OVER TO SNOW. WE ARE EXPECTING SLIGHTLY LESS TOTAL SNOWFALL THAN
BEFORE...AS THE BACK EDGE OF THIS PRECIPITATION ALREADY IS
SWEEPING ACROSS SW LOWER MI.
WE ARE WATCHING FOG DEVELOP JUST SOUTH OF I-94. A CLOUD LAYER
ASSOCIATED WITH THE PRECIPITATION SHOULD REDUCE THE FOG IN THE
NEXT FEW HOURS. AFTERWARDS WE MAY SEE SOME FOG REDEVELOP TOWARDS
SUNRISE...BUT NOTHING DENSE IS EXPECTED AT THIS TIME.
UPDATE ISSUED AT 650 PM EST WED FEB 22 2012
MADE TIMING ADJUSTMENTS TO PRECIPITATION CHANCES THROUGH 2 AM.
PRECIPITATION TYPE IS EXPECTED TO BE RAIN INITIALLY AS IT NOW IS
IN WI...THANKS TO CURRENT SURFACE TEMPERATURES AND DEWPOINTS OVER
MUCH OF LOWER MI. A GRADUAL CHANGEOVER TO SNOW SHOULD OCCUR MAINLY
AFTER 10 PM.
HRRR SHORT RANGE GUIDANCE CONTINUES TO SUPPORT A NARROW BAND OF
SNOW CROSSING THE I-96 CORRIDOR TONIGHT...AND THIS IS SUPPORTED BY
THE 22/12Z NCEP NESTED ARW/NMM NAM. IMPACTS ARE EXPECTED TO BE
MINIMAL GIVEN TIMING AND EXPECTED INTENSITY.
UPDATE ISSUED AT 444 PM EST WED FEB 22 2012
WILL BE ISSUING A WINTER STORM WATCH SHORTLY FOR THE CWA FROM
THURSDAY AFTERNOON INTO FRIDAY MORNING BASED LARGELY ON LATEST
ECMWF GUIDANCE. WILL TRY TO HAVE THE WATCH OUT BY 5 PM.
&&
.SYNOPSIS...
ISSUED AT 1045 PM EST WED FEB 22 2012
AFTER MOSTLY LIGHT PRECIPITATION MOVES THROUGH THE AREA OVERNIGHT...HIGH
PRESSURE WILL BRING CLEARING CONDITIONS TO THE AREA THURSDAY
MORNING. A STORM DEVELOPING IN THE SOUTHERN PLAINS WILL APPROACH
THE AREA DURING THE DAY THURSDAY...BRINGING A PERIOD OF
SIGNIFICANT SNOWFALL TO THE AREA THURSDAY NIGHT. SOME LAKE EFFECT
SNOW IS EXPECTED INTO SATURDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED FEB 22 2012
THERE IS THE THREAT FOR A SIGNIFICANT SNOWFALL EVENT THURSDAY
NIGHT INTO FRIDAY. CURRENT THINKING IS 4 TO 7 INCHES OVER THE
CENTRAL CWA... NEAR INTERSTATE 96. MOST OF THE SNOW SHOULD FALL
DURING THE MID TO LATE EVENING HOURS OF THURSDAY NIGHT INTO THE
MID MORNING HOURS OF FRIDAY.
THERE IS ALSO THE THREAT FOR A BRIEF BURST OF SIGNIFICANT SNOW THIS
EVENING AS A SHORTWAVE OVER WISCONSIN HEADS EAST ACROSS LAKE
MICHIGAN AND INTENSIFIES THIS EVENING. BOTH THE HRRR SUGGESTS UP
TO .25 INCHES OF QPF IN 3 HOURS OVER PARTS OF NORTHERN OTTAWA AND
CENTRAL AND NORTHERN KENT COUNTIES BY BETWEEN 9 PM AND MIDNIGHT.
SINCE THE PRECIPITATION AREA ALREADY IS OVER CENTRAL WISCONSIN AND
IS HEADED EAST... IT WOULD SEEM MORE THAN REASONABLE THIS WOULD
IMPACT CENTRAL LOWER MICHIGAN THIS EVENING. THERE IS GOOD LIFT IN
THE DGZ AS THIS FEATURE MOVES THROUGH THE AREA SO THAT SHOULD HELP
THE SNOWFLAKE PRODUCTION. WITH SURFACE DEW POINTS IN THE MID 20S
THE SNOW WILL WET BULB DOWN THE AIR TEMP QUICKLY SO SNOW WILL REACH
THE GROUND.
ONCE THAT FEATURE MOVES EAST OF THE CWA LATER THIS EVENING SHORT
WAVE RIDGING FOLLOWS LATE TONIGHT INTO MIDDAY THURSDAY. THAT
SHOULD ALLOW THE SKIES TO BECOME PARTLY CLOUDY...AT LEAST FOR A
TIME.
THEN WE HAVE THE ISSUE OF OUR STORM ON THURSDAY NIGHT. THE GFS AND
NAM HAVE BEEN CONSISTENTLY FARTHER NORTH THEN THE ECMWF HAS BEEN
WITH THIS SYSTEM. HOWEVER... THE ECMWF HAS FINALLY SHOWED A
SIGNIFICANT SHIFT NORTHWARD IN THE TRACK OF THE SYSTEM THURSDAY
NIGHT. THE REGIONAL GEM IS FARTHER NORTH AND WEST THAN IS THE
HEMISPHERIC GEM... TRACKING THE LOW NEAR DETROIT LATE THURSDAY
NIGHT. THERE IS SIGNIFICANT FGEN SUPPORT OF THIS EVENT AS IT IS
EXIT REGION OF 165 KNOT 300 MB JET CORE THAT TURNS CYCLONIC AS
IT HEADS NORTHEAST TOWARD CENTRAL OHIO FRIDAY MORNING. THIS ALSO
CREATES QUIET THE TROWAL FEATURE WITH STRONG ISOTROPIC LIFT. THERE
IS 3 TO 4 G/KG OF WATER NEAR 700 MB WHILE THIS IS GOING ON SO
SNOWFALL AMOUNTS OF 3 TO 6 INCHES SHOULD BE EASY TO DO WITH THIS
SET UP.
I WOULD HAVE ISSUED A WINTER STORM WATCH FOR THIS EVENT EXPECT FOR
THE ISSUE OF MODEL UNCERTAINTY. I WILL LET THE MIDNIGHT SHIFT
CONSIDER DOING JUST THAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 PM EST WED FEB 22 2012
UNSETTLED/ACTIVE WEATHER IS EXPECTED TO GENERALLY CONTINUE THROUGH
THE LONG TERM PORTION OF THE FORECAST...IF NOT THE NEXT COUPLE OF
WEEKS. MAIN ITEMS OF CONCERN ARE LINGERING SNOW ON FRI...LAKE EFFECT
FRI NIGHT/SAT...SYSTEM COMING IN LATE SUN THROUGH MON...AND LAKE
EFFECT AGAIN ON TUE.
AN ACTIVE JET STREAM IS EXPECTED TO AFFECT MOST OF THE COUNTRY
THROUGH THE NEXT WEEK. WE ARE EXPECTING TO SEE STRONG PIECES OF
ENERGY BE PUSHED ACROSS THE COUNTRY...FUELED BY A VERY STRONG JET
OVER THE NRN PACIFIC. A LOT OF THIS ENERGY IS EXPECTED TO DIVE SE
INTO THE WRN STATES...BEFORE LIFTING E/NE TOWARD THE GREAT LAKES
REGION.
WE WILL SEE THE FIRST IN THE SERIES OF PV ANOMALIES/WAVES BE MOVING
OUT OF THE AREA AFTER DEPOSITING ACCUMULATING SNOW THU NIGHT AND
INTO FRI. IN THE WAKE OF THIS PHASED UPPER FEATURE...A POOL OF
ARCTIC AIR TO OUR NW WILL BE TAPPED AND WILL PUSH INTO THE AREA.
SYNOPTIC SNOW WILL LIKELY BE ONGOING EARLY ON FRI BEFORE TAPERING
OFF DURING THE DAY. THE SNOW WILL TRANSITION TO SOME LAKE EFFECT AS
H850 TEMPS DROP DOWN TO AROUND -10C TO -12C. WE COULD SEE SOME
DECENT LAKE EFFECT ACCUMS FOR MAINLY NW FAVORED AREAS WITH MOISTURE
POTENTIALLY UP THROUGH 10K FT LATE FRI AND FRI NIGHT. INVERSION
HEIGHTS WILL GRADUALLY FALL THROUGH SAT AS THE UPPER FLOW WILL
TRANSITION TO ANTI-CYCLONIC BY SAT EVENING.
WE WILL SEE A BRIEF BREAK IN THE WEATHER THEN SAT NIGHT THROUGH A
GOOD PORTION OF SUN FOR MOST AREAS AS RIDGING BUILDS IN. NW AREAS
COULD SEE SOME LIGHT PCPN SUN AFTERNOON AS WAA/ISENTROPIC ASCENT
STRENGTHENS AHEAD OF THE NEXT SYSTEM. THE UNSETTLED WEATHER WILL
SPREAD ACROSS THE ENTIRE AREA SUN NIGHT AS THE NEXT STRONG WAVE
DIVING INTO THE SW U.S. EARLY IN THE WEEKEND WILL LIFT NE. THIS WILL
LIKELY TAP SOME WARMER AND MOIST AIR FROM THE GULF AND ADVECT IT
INTO THE AREA LATE SUN THROUGH MON MORNING. PCPN COULD START OFF AS
SNOW...BUT SHOULD CHANGE OVER TO RAIN FOR A PERIOD SUN NIGHT AND
EARLY MON. THUNDER CAN NOT EVEN BE RULED OUT WITH THE STRONG FORCING
ASSOCIATED WITH THE SYSTEM. NOT CONFIDENT ENOUGH YET TO ADD THUNDER
INTO THE FCST.
THE COLD FRONT WILL MOVE THROUGH ON MON...AND A FLOOD OF COLDER AIR
WILL MOVE IN ACROSS THE STATE. THIS WILL HELP TO START THE LAKE
EFFECT BACK UP AS H850 TEMPS DROP BACK DOWN TO AROUND -10C TO -12C.
MODELS ARE INDICATING THOUGH THAT THE LOW LEVEL FLOW WILL TEND TO BE
NE WITH THE WAY THE RIDGE BUILDS IN FROM THE NW. THIS WILL TEND TO
LIMIT THE LAKE EFFECT CHCS AND AMOUNTS. QUITE A BIT OF UNCERTAINTY
WITH REGARDS TO TIMING AND TRACK WITH ANOTHER WAVE THAT IS EXPECTED
TO LIFT OUT FROM THE WRN U.S. BY MID WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EST WED FEB 22 2012
BRIEFLY SAW IFR VISIBILITY AT KGRR WITH LARGE SNOWFLAKES FALLING.
THE ASSOCIATED AREA OF HEAVIER PRECIPITATION MOVING EAST TOWARDS
KLAN SHOULD BE PREDOMINANTLY SNOW AND BRING...BREIF IFR VSBYS
THERE TOO. ELSEWHERE...DO NOT EXPECT SUCH DRASTIC RESTRICTIONS. KJXN
IS THE TYPICAL EXCEPTION WITH LIFR CIGS ALREADY BEING REPORTED...
AND EXPECT THIS TO CONTINUE. AS IS ALREADY SEEN AT KMKG...WE
SHOULD SEE A FAIRLY QUICK TRANSITION TO MVFR/VFR CONDITONS BY 12Z
AT MOST TERMINALS.
&&
.MARINE...
ISSUED AT 1045 PM EST WED FEB 22 2012
HAVE ALLOWED THE SMALL CRAFT ADVISORY TO EXPIRE. WINDS AND WAVES
WILL CONTINUE A RAPID DOWNWARD TREND.
&&
.HYDROLOGY...
ISSUED AT 400 PM EST WED FEB 22 2012
NO SIGNIFICANT HYDROLOGY ISSUES ARE EXPECTED AS THE PRECIPITATION
THAT FALLS WILL BE IN THE FROM FOR SNOW. NONE OF RIVERS ARE AT OR
ABOVE ACTION STAGE CURRENTLY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ037>040-043>046-050>052-056>059-064>067-
071>074.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...TJT
SHORT TERM...WDM
LONG TERM....NJJ
AVIATION...TJT
MARINE...TJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
342 PM CST THU FEB 23 2012
.DISCUSSION...
TONIGHT AND FRIDAY...STUBBORN LGT/MOD SNOW HAS CONTINUED OVER FAR
SW MN WHILE THE REST OF THE COVERAGE AREA HAS REMAINED DRY BUT
UNDER LOW EXTENSIVE CLOUD COVER. THE SWATH OF SNOW ALIGNS NICELY
WITH A WEAK SFC TROUGH EXTENDING NW FROM A PARENT SFC LOW OVER MO
TREKKING E INTO THE SRN OHIO VALLEY. AS THIS SYSTEM CONTINUES TO
SHIFT E OVERNIGHT...THE SNOW OVER SWRN MN WILL COME TO AN END BUT
WILL BE REPLACED BY FLURRIES/SNOW SHOWERS DURG THE DAY TMRW FOR
MAINLY CENTRAL AND ERN PORTIONS OF THE COVERAGE AREA. A CDFNT
DROPPING S FROM CENTRAL CANADA FOLLOWED BY AN UPPER LEVEL CUTOFF
LOW NUDGING THE FRONT ALONG WILL HAVE PRETTY MEAGER MOISTURE GOING
ALONG. LITTLE/NO ACCUMS ARE EXPECTED BUT HAVE KEPT POPS IN THE
20-40 PERCENT RANGE. WITH THIS FROPA WILL COME A DOSE OF CAA THAT
WILL MAKE FOR A SMALL DIURNAL RANGE FROM TNGT INTO FRI.
FRIDAY NIGHT THROUGH SUNDAY...BRIEF RESPITE FROM SENSIBLE WX COMES
FRI NIGHT THROUGH SAT AS SFC HIGH PRES ALONG WITH THE WINDWARD
SIDE OF UPPER RIDGING DROPS THROUGH THE AREA. MIN TEMPS WILL DROP
CLOSE TO OR SLIGHTLY BELOW NORMAL LEVELS FRI NIGHT THEN AMPLE
SUNSHINE DURING THE FIRST HALF OF THE DAY SAT WILL ALLOW TEMPS TO
REBOUND NICELY TO NORMAL LEVELS AS THE BACKSIDE OF THE RIDGE MOVES
ACROSS. CLOUDS WILL BE ON THE INCRS SAT NIGHT INTO SUN AS AN AREA
OF LOW PRES DROPPING INTO THE ROCKIES FROM MANITOBA PHASES WITH A
SECONDARY LOW PRES CENTER OVER THE CENTRAL PLAINS. THIS COMBINED
SYSTEM WILL THEN TRAVERSE E ACRS THE DAKOTAS INTO WRN MN WHERE IT
WILL THEN SHIFT NE TWD THE U.P. OF MICHIGAN. THE EVER-SO-SLOWLY
SHIFT OF THE TRACK TO N OF THE MPX COVERAGE AREA MEANS LESSER
EXPECTED SNOWFALL AND WITH ADDITIONAL WARMER AIR BEING ENVELOPED
INTO THE SYSTEM...PARTS OF THE TIME FROM SUN AFTN INTO SUN EVE
WILL HAVE A RAIN/SNOW MIX FOR PORTIONS OF THE AREA S OF I-94. THE
HEAVIER SNOWS MAY IMPACT NRN FRINGES OF THE COVERAGE AREA BUT SNOW
AMOUNTS WILL GENERALLY BE 3 INCHES OR LESS FROM THE SYSTEM ON
SUNDAY FOR CENTRAL-SRN MN WHILE AMOUNTS INCREASE GOING WELL N.
MONDAY THROUGH WEDNESDAY...QUITE THE INTERESTING PATTERN
DEVELOPING FOR THE MIDDLE OF THE WEEK AMONG THE MODELS. ANOTHER
BRIEF RESPITE FROM WX IS EXPECTED MON INTO TUE AS SFC HIGH PRES
AND A SHARP UPPER RIDGE AXIS PUSH OVER THE AREA. FOLLOWING THE
RIDGE...THE MODELS RAMP UP A VERY POTENT SYSTEM FOR THE MIDDLE OF
NEXT WEEK. BETWEEN THE ECMWF AND GFS...BOTH SHOW CYCLOGENESIS OVER
THE CENTRAL PLAINS THAT IS AMPLIFIED BY A NEGATIVELY-TILTED UPPER
LEVEL TROUGH AND A DIRECT MOISTURE TAP FROM THE GULF OF MEXICO.
THE TRACK OF THIS SYSTEM LOOKS TO BE SW TO NE WHILE REMAINING JUST
S OF THE MPX COVERAGE AREA. IN ADDITION...THE ECMWF SLOWS ITS
PROGRESS OF THE SYSTEM OVER IOWA WHICH WOULD GREATLY ENHANCE
SNOWFALL POTENTIAL FOR SRN MN INTO WRN WI. THERE ARE A LOT OF
FACTORS TO COME INTO PLAY...HENCE POPS KEPT ONLY IN THE 20-30
PERCENT RANGES...BUT THE EVOLUTION OF THIS SYSTEM BEARS WATCHING.
TEMPERATURES BOUNCE AROUND DURING THE FIRST HALF OF THE WEEK BUT
REMAIN NEAR TO BELOW NORMAL.
&&
.AVIATION.../18Z TAF ISSUANCE/
BIG ISSUE FOR THIS TAF PERIOD IS WHAT TO DO WITH CLOUDS.
IMPRESSIVE BAND OF SNOW OVER SE SODAK HEADING FOR CENTRAL IA AND
WILL BE MISSING ALL TAFS. SEEING PLENTY OF MID CLOUDS SPILLING
INTO THE AREA ASSOCIATED WITH THIS WAVE...BUT MORE FRUSTRATING IS
THE AMPLE MOISTURE BETWEEN 025 AND 035 THAT HAS LED TO RANDOM
CLOUD BANKS AROUND 3K FT. RH PROFILES FROM NAM/GFS/RUC SHOW THIS
MOISTURE WANING ACROSS THE AREA AFTER 00Z...SO SHOULD SEE CLOUDS
IN THIS LAYER DIMINISH AFTER SUNSET. AFTER THAT...WATCHING SWATH
OF SNOW MOVING EAST ACROSS NODAK...HAVE BEEN SOME 1/4SM VSBY SNOWS
IN NODAK...BUT HRRR REFLECTIVITY AND MODEL QPF FORECASTS ALL
SAYING THIS WILL BE DIMINISHING AS HITS MN. USED COMBO OF HRRR/RUC
THEN GFS TO TIME THIS BAND OF FORCING ACROSS THE AREA. ONLY HAVE
-SN MENTIONED AT AXN GIVEN THE UPSTREAM OBS...BUT ALL COULD SEE A
QUICK BURST OF SNOW AS IT MOVES THROUGH. WINDS HAVE BEEN A BIT
TRICKY TODAY ACROSS ERN MN/WRN WI WHERE WINDS HAVE BEEN OUT OF THE
SE OUT AHEAD OF A RIDGE AXIS. WINDS WILL QUICKLY BACK TO THE NORTH
BEHIND THE RIDGE AND CURRENT TAFS FOR MSP/RNH MAY BE HOLDING ON TO
SE WINDS TOO LONG. FOR THE END OF THE TAF...STRONG CAA LOOKS TO
SET IN...WITH MODELS SHOWING A HEALTHY AMOUNT OF MIXING
OCCURRING...BY LATE MORNING. COULD SEE SOME NW GUSTS OVER 30 KTS
FRIDAY OVER MN.
KMSP...CONFIDENCE IN CLOUD FORECAST NOT ALL THAT HIGH...SHOULD SEE
025-035 CIGS HANG AROUND THROUGH AT LEAST 20Z. AFTER THAT...HARD
TO SAY WHAT WILL HAPPEN BELOW 12K FT. MODELS SHOW PLENTY OF
MOISTURE HANGING AROUND THIS LAYER...BUT OBS TO THE WEST SHOW
CLOUDS IN THIS LAYER ONLY AS FAR WEST AS LJF/GYL...SO WENT WITH
THE IDEA OF THESE CLOUDS DIMINISHING AROUND 22Z. BASED ON GFS
TIMING...BAND OF SNOW CURRENTLY OVER ERN NODAK WOULD ARRIVE AT MSP
AROUND 09Z. SREF PROBS FOR PRECIP ACTUALLY INCREASE ACROSS ERN MN
LATE TONIGHT...SO CERTAINLY POSSIBLE THAT THE VCSH GROUP MAY NEED
AT LEAST A TEMPO -SN. FOR FRIDAY...STRONG CAA WILL BE SETTING IN.
BESIDE BRINGING GUSTY NW WINDS...IT LOOKS HIGHLY LIKELY THAT IT
WILL ALSO BRING WITH IT SOME MVFR STRATUS...ALONG WITH SOME
INSTABILITY SNOW SHOWERS THROUGH MUCH OF FRIDAY AFTERNOON.
//OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
.FRIDAY NIGHT...MVFR CIGS BECOMING VFR.
.SATURDAY...VFR.
.SUNDAY...MVFR/IFR POSSIBLE WITH CHANCE OF RA/SN.
.MONDAY-TUESDAY...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1228 PM CST THU FEB 23 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
IT HAS BEEN A TOUGH CALL WITH THIS SYSTEM. SHORT TERM MODEL TRENDS
HRRR/VSREF ARE SHOWING THE SNOW BAND JUST TO OUR SOUTHWEST. THE
UPPER JET/THICKNESS PATTERN STARTING OUT SOMEWHAT CONFLUENT TO
OUR SOUTHEAST AND THEN THE DEVELOPING DIFLUENT PATTERN SETS UP
OVER WESTERN IOWA AND EASTERN NEBRASKA AS THE WAVE DROPS SOUTHEAST.
BEST SURFACE PRESSURE FALLS OVER EASTERN KANSAS NOW. CLOSE CALL
WITH THE NORTH EDGE OF THE FGEN FORCING. QUITE STRONG OVER IOWA.
WILL TRIM BACK FURTHER ON THE EAST EDGE OF THE ADVSY BUT KEEP IN
ONE COUNTY FOR NOW. STILL A POSSIBILITY OF PICKING UP CLOSE TO 3
INCHES...WITH LESSER AMOUNTS TO THE EAST. NOT MUCH IN THE WAY OR
FORCING FOR THE REST OF THE AREA UNTIL THE MANITOBA WAVE DROPS SSE
ACROSS THE ARE LATER TONIGHT AND FRIDAY. KEEPING POPS IN THE
CHANCE CATEGORY FOR NOW...BUT THERE IS A CHANCE OF WIDER COVERAGE
IF DEPTH OF THE DENDRITIC ZONE INCREASES OVER EASTERN AREAS.
THE ACTIVE PATTERN WITH THE STRONG..MAINLY WESTERLY UPPER JET
CONTINUES THROUGH THE WEEKEND AND INTO NEXT WEEK WITH 2 MORE
SYSTEMS TO AFFECT THE AREA. THERE SEEMS TO BE A CONSISTENT TRACK
WITH THE SYSTEM FOR SUNDAY. A KIND OF HYBRID PACIFIC/HIGH PLANS
TYPE SYSTEM...GENERALLY TRACING EAST. STILL LOOKS TO AFFECT THE
NORTHERN CWA WITH THE HEAVIEST SNOW POTENTIAL. THERE MAY BE A RAIN
SNOW MIX FOR A TIME IN THE SOUTH.
THE NEXT SYSTEM FOR WEDNESDAY APPEARS TO HAVE A CHANCE FOR THE
GULF TO OPEN UP A BIT AND LOOKS TO BE A COLORADO/PLAINS LOW AND A
TRACK FAVORING THE SOUTHERN AND EASTERN CWA. A COUPLED UPPER JET
PATTERN ALSO DEVELOPS FOR A TIME JUST TO OUR EAST. STILL TOO EARLY
TO GO REAL HIGH WITH THE POPS THIS FAR OUT. THE TEMP PATTERN
HEADING TO A LITTLE BELOW NORMAL BUT NOT BY MUCH.
&&
.AVIATION.../18Z TAF ISSUANCE/
BIG ISSUE FOR THIS TAF PERIOD IS WHAT TO DO WITH CLOUDS.
IMPRESSIVE BAND OF SNOW OVER SE SODAK HEADING FOR CENTRAL IA AND
WILL BE MISSING ALL TAFS. SEEING PLENTY OF MID CLOUDS SPILLING
INTO THE AREA ASSOCIATED WITH THIS WAVE...BUT MORE FRUSTRATING IS
THE AMPLE MOISTURE BETWEEN 025 AND 035 THAT HAS LED TO RANDOM
CLOUD BANKS AROUND 3K FT. RH PROFILES FROM NAM/GFS/RUC SHOW THIS
MOISTURE WANING ACROSS THE AREA AFTER 00Z...SO SHOULD SEE CLOUDS
IN THIS LAYER DIMINISH AFTER SUNSET. AFTER THAT...WATCHING SWATH
OF SNOW MOVING EAST ACROSS NODAK...HAVE BEEN SOME 1/4SM VSBY SNOWS
IN NODAK...BUT HRRR REFLECTIVITY AND MODEL QPF FORECASTS ALL
SAYING THIS WILL BE DIMINISHING AS HITS MN. USED COMBO OF HRRR/RUC
THEN GFS TO TIME THIS BAND OF FORCING ACROSS THE AREA. ONLY HAVE
-SN MENTIONED AT AXN GIVEN THE UPSTREAM OBS...BUT ALL COULD SEE A
QUICK BURST OF SNOW AS IT MOVES THROUGH. WINDS HAVE BEEN A BIT
TRICKY TODAY ACROSS ERN MN/WRN WI WHERE WINDS HAVE BEEN OUT OF THE
SE OUT AHEAD OF A RIDGE AXIS. WINDS WILL QUICKLY BACK TO THE NORTH
BEHIND THE RIDGE AND CURRENT TAFS FOR MSP/RNH MAY BE HOLDING ON TO
SE WINDS TOO LONG. FOR THE END OF THE TAF...STRONG CAA LOOKS TO
SET IN...WITH MODELS SHOWING A HEALTHY AMOUNT OF MIXING
OCCURRING...BY LATE MORNING. COULD SEE SOME NW GUSTS OVER 30 KTS
FRIDAY OVER MN.
KMSP...CONFIDENCE IN CLOUD FORECAST NOT ALL THAT HIGH...SHOULD SEE
025-035 CIGS HANG AROUND THROUGH AT LEAST 20Z. AFTER THAT...HARD
TO SAY WHAT WILL HAPPEN BELOW 12K FT. MODELS SHOW PLENTY OF
MOISTURE HANGING AROUND THIS LAYER...BUT OBS TO THE WEST SHOW
CLOUDS IN THIS LAYER ONLY AS FAR WEST AS LJF/GYL...SO WENT WITH
THE IDEA OF THESE CLOUDS DIMINISHING AROUND 22Z. BASED ON GFS
TIMING...BAND OF SNOW CURRENTLY OVER ERN NODAK WOULD ARRIVE AT MSP
AROUND 09Z. SREF PROBS FOR PRECIP ACTUALLY INCREASE ACROSS ERN MN
LATE TONIGHT...SO CERTAINLY POSSIBLE THAT THE VCSH GROUP MAY NEED
AT LEAST A TEMPO -SN. FOR FRIDAY...STRONG CAA WILL BE SETTING IN.
BESIDE BRINGING GUSTY NW WINDS...IT LOOKS HIGHLY LIKELY THAT IT
WILL ALSO BRING WITH IT SOME MVFR STRATUS...ALONG WITH SOME
INSTABILITY SNOW SHOWERS THROUGH MUCH OF FRIDAY AFTERNOON.
//OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY...
.FRIDAY NIGHT...MVFR CIGS BECOMING VFR.
.SATURDAY...VFR.
.SUNDAY...MVFR/IFR POSSIBLE WITH CHANCE OF RA/SN.
.MONDAY-TUESDAY...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPR/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1145 PM CST WED FEB 22 2012
.DISCUSSION...
UPDATED PREVIOUS FORECAST AND RESOLVED WATCH INTO ADVISORY FOR
MAINLY ALONG THE INTERSTATE 90 CORRIDOR. 2-4 INCHES POSSIBLE
THERE. MODELS TRENDED TO A MORE SOUTHERLY TRACK BEGINNING WITH THE
00Z RUC.
&&
.AVIATION.../06Z TAF ISSUANCE/
MODELS SHIFTED MAIN SNOW ACTIVITY WELL SOUTH OF TAF SITES. MAY SEE
SOME FLURRIES INTO THE AFTERNOON AND MAINTAINED A VCSH FOR THAT
AT SEVERAL MN SITES. MVFR CIGS DEVELOPING OVER THE WESTERN
AREAS...WITH SOME FOG AS WELL...AS LOW CLOUDS MOVES EAST THIS
EVENING. WILL MENTION SOME MVFR BR AT KAXN WITH CEILINGS GOING IFR
DURING THE EARLY MORNING. AT THIS TIME WILL DROP CEILINGS DURING
THE DAY IN MN TO MVFR AND WILL MAINTAIN VFR AT KEAU UNTIL EVENING.
REAL CHANCE OF SNOW TO COME WITH NEXT WAVE ROTATING SOUTHEAST
BEHIND THE DEPARTING SYSTEM LATER TONIGHT AND DID MENTION THAT
VCSH/-SN AT MN LOCATIONS. LIGHT WINDS BECOMING MORE EAST OVERNIGHT
AND EVENTUALLY NORTHWEST LATE TONIGHT IN THE WAKE OF THE IOWA LOW.
SHOULD REMAIN MAINLY BELOW 10 KNOTS THROUGH THE TAF PERIOD.
KMSP...EXPECT VFR CONDITIONS UNTIL ABOUT 11Z THEN MVFR THROUGH THE
DAY AS IOWA SYSTEM EXITS TO THE EAST DID MENTION VCSH FOR POSSIBLE
FLURRIES INTO THE AFTERNOON...WITH THE BETTER CHANCE OF FLURRIES
MOVING IN OVERNIGHT AS ANOTHER TROUGH MOVES IN BEHIND THE INITIAL
SYSTEM. WILL SEE EAST SURFACE WINDS BECOMING MORE NORTH DURING THE
DAY AS SYSTEM EXITS TO THE EAST. SHOULD REMAIN BELOW 10 KNOTS
THROUGH THE PERIOD.
&&
.PREV DISCUSSION...
/ISSUED 522 PM CST WED FEB 22 2012/
SUMMARY...QUITE THE DAY HERE AT THE NWS OFFICE TODAY. THREE
POTENTIAL SNOW STORMS IN THE FORECAST AREA OVER THE NEXT 160 HOURS
AND PLENTY OF MODEL DISAGREEMENT TO GO ALONG WITH IT.
FIRST THINGS FIRST...SHORTWAVE PASSING THROUGH THIS AFTERNOON
YIELDING ISOLATED TO SCATTERED LIGHT SNOW SHOWERS...SHOULD BE
THROUGH EARLY THIS EVENING AND LOOKS DRY FOR SEVERAL HOURS BEFORE
THE SURFACE LOW FROM THE NORTHWEST. LOOK OF POTENTIAL WITH THIS
STORM FOR TONIGHT...BUT THE QUESTION TODAY HAS NOT BEEN IF THERE
WILL BE A 6+" SNOWBAND...BUT WHERE. IN GENERAL...THERE HAS BEEN
TWO CLUSTERS OF MODEL GUIDANCE: THE UKMET/EC IN ONE CAMP AND THE
GFS/GEM/SREF/ IN THE OTHER. THE 12Z NAM WAS AN OUTLIER TO THE
NORTH AND BROUGHT THE HEAVY SNOW ACROSS CENTRAL MN...INCLUDING THE
TWIN CITIES METRO. THE 18Z NAM JOINED THE GFS/SREF/GEM CAMP AND
CAME IN MUCH FURTHER SOUTH. DEBATED ON UPGRADING THE WATCH TO A
COMBINATION OF WARNING/ADVISORY WITH THE HEAVIEST ACCUMULATIONS IN
MARTIN AND FARIBAULT COUNTIES. IN FACT...EVEN HAD THE WARNING
DRAWN UP LATE THIS AFTERNOON...BUT THE LAST FRAME OF THE HRRR
AGREES QUITE WELL WITH THE ECMWF AND WOULD KEEP ALMOST ALL OF THE
SNOW OUT OF THE FORECAST AREA.
THERE IS ALREADY A LIGHTNING STRIKE UPSTREAM IN MONTANA THIS
AFTERNOON...WHICH IS USUALLY A PRETTY GOOD INDICATOR OF THE
STRENGTH OF THIS SYSTEM. NO SURPRISE WITH 992-993MB SURFACE LOW
DROPPING SOUTH ACROSS WESTERN IA BASED ON THE NAM/GFS...THERE IS
VERY GOOD 800-600MB FGEN TO GO ALONG WITH NEGATIVE EPV AND AT
LEAST SOME ELEVATED INSTABILITY-BEST LI APPROACHES THE FORECAST
AREA WITH 2/3 GRAM MIXING RATIOS OFF THE ISENTROPIC SURFACES. THE
FORECAST SIDES WITH THE GFS/GEM/NAM/SREF CLUSTER OF SOLUTIONS.
HOWEVER...LOW CONFIDENCE WITH NOW THE LATEST HRRR AGREEING QUITE
WELL WITH THE ECMWF. IT`S A FEAST OF FAMINE SITUATION-THERE WILL
LIKELY BE 6-10 INCHES...POSSIBLY A FOOT...IN A NARROW CORRIDOR
WHERE THE BEST FORCING SETS UP AND NOT MUCH TO THE NORTH OF IT.
DRAMATICALLY REDUCED POPS AND AMOUNT OF SNOW IN METRO...MIGHT BE
NOTHING AT. USUALLY GOOD SUBSIDENCE ON NORTH SIDE OF THE
DEFORMATION.
IN THE EXTENDED...THE SUNDAY/MONDAY SYSTEM LOOKS POTENT...JUST NOT
SOME MUCH FOR HERE WITH THE SURFACE LOW TRACKING OVERHEAD AND HIGH
POTENTIAL FOR DRY SLOT BASED ON THE ASSORTMENT OF OPERATIONAL RUNS
AND ENSEMBLE GUIDANCE. UNLESS SOMETHING CHANGES...A LOT OF SNOW
AND WIND IN THE DAKOTAS AND NORTHERN MN AND NOT MUCH HERE. GFS
SPITS OUT THE HIGHEST QPF...BUT IT MIGHT BE OVERDONE. THERE ARE
FAIRLY HIGH POPS IN THE FORECAST...BUT OVERALL...DOESN`T LOOK LIKE
ANYTHING MAJOR IN THE IMMEDIATE AREA. THERE`S ANOTHER WHOPPER OFF
THE GFS THIS TIME NEXT...BUT NOT SHOWING UP AS MUCH ON THE ECMWF
AND GFS ENSEMBLE TO SOME DEGREE. THE 12Z GFS HAD A BAND OF 12-18"
IN SOUTHERN MN...SOMETHING THAT WILL LIKELY CHANGE WITH TIME.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST THURSDAY FOR
FARIBAULT-FREEBORN-MARTIN-WATONWAN.
WI...NONE.
&&
$$
DWE/JVM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
345 PM CST THU FEB 23 2012
...UPDATED PUBLIC AND AVIATION...
.DISCUSSION...
As expected, temperatures soared well into the 60s within the warm
sector early this afternoon, even more so than anticipated with the
earlier update. 20Z surface analysis continued to show a complex
frontal structure with two surface lows extending from near Omaha to
near Moberly, with most of the CWA now located in the post-frontal
airmass. Gusty northwest winds will continue to surge east across
the remainder of the CWA through 00Z, accompanied by extensive
cloud cover and steadily falling temperatures.
Two primary concerns as we head into this evening.
1.) Wind. The RUC13 has done an outstanding job with the
placement/intensity of strong winds across Nebraska/Kansas today,
which justifies my earlier concern with respect to the ongoing wind
advisory. Increasing friction (terrain, trees, etc...) over the
eastern Plains coupled with the loss of daytime heating will both
act against a simple advection of upstream conditions into the
western CWA this evening. Already pushed back the start time of the
wind advisory until 6PM, which looks reasonable given the
juxtaposition of the strongest winds immediately south/southeast of
the digging mid-level trough axis. However, considering both minimal
impacts (after the evening commute) and the aforementioned
meteorology, am concerned that the advisory may no longer be
warranted. Still, we may see both sustained speeds and gusts locally
meet criteria (30/45), and will leave the headline active through
this evening. Still will be a windy/blustery evening regardless,
with 60s giving way to 30s by midnight.
2.) Precipitation. Satellite presentation with the mid level trough
over eastern Nebraska continues to improve this afternoon, and
additional deepening is expected as the wave digs southeast along
the Nebraska/Missouri border overnight. A compact area of vigorous
ascent and diabatic cooling immediately behind the trough, acting as
a small scale deformation band, may affect the far northern tier
counties between 9-10PM and shifting east through the overnight
hours. Given favorable dendritic snow growth profiles, it is
possible that a period of moderate to heavy snow could brush the
Iowa border counties, resulting in minor accumulations. Do expect
Iowa/Illinois to receive the brunt of this evening and for now have
painted an inch across the northern counties, but would not be
surprised if a short-fused advisory became necessary overnight.
Evening hazardous weather outlook will be amended as necessary to
reflect this impact. If concerns #1 and
#2 overlap at some point tonight, we could have an additional issue
with blowing snow/visibilities impacting travel north of highway 36.
Otherwise, gusty winds and strong cold advection will continue into
tomorrow. Previous forecast already reflected undercutting guidance
on temperatures and made no change there. Cyclonic flow will
maintain cloud cover, especially over the northeast half of the CWA
and would not be surprised to see a few sprinkles/flurries from time
to time either.
Return flow comes back in a hurry Saturday afternoon, with winds
increasing over the western CWA. Should see another 10-15 degree
gradient from northeast Missouri to eastern Kansas.
Bookbinder
Medium Range (Sunday through Thursday)...
The focus for the weather over the latter half of the forecast is on
two features; the first a shortwave due to zip east through the
Northern Plains into the Great Lakes Saturday into Sunday; the
second shortwave of note will then follow on quickly through the
Central Plains Monday night through Wednesday.
Leading shortwave, due to pass through the Plains Saturday/Sunday,
will be starved for moisture. A surface high slowly shifting east
along the Gulf Coast will effectively shut off any return moisture
from the Gulf over the weekend. Couple that observation with the
notable speed with which this shortwave jets east through the
Northern Plains, and precipitation of any form for the weekend looks
like a non-issue. Have kept the forecast dry, and boosted afternoon
highs on the expectation of breezy southwest winds. This should put
temperatures for the last day of the weekend into the 50s to low
60s.
After the passage of the weekend leading shortwave, a second wave is
due to pass through the Central Plains during the beginning of the
work week. Sunday`s shortwave, while dry, will have the ultimate
effect of shoving the baroclinic zone a little father south as weak
high pressure oozes into the Northern Plains, pushing afternoon
highs back down towards normal. This results in the second wave
kicking out across the plains form the Four Corners region, zipping
through the Lower Missouri River Valley. At this point the surface
high along the Gulf Coast will have advected east under the
influence of the progressive flow across the nation, leaving the
Gulf open to allow moisture return which the second shortwave will
be able to tap.
This second system has the potential to be significant weather
maker. While models are in decent enough broad agreement on the
general trend of the shortwave to warrant including likely POPs for
part of Tuesday and Tuesday night, preference on the specifics of
shortwave timing are hedged towards the faster ECMWF and GEM
solutions. GFS is the slowest in ejecting the wave, which seems a
bit off given the progressive flow. Anyhow, have limited snow POPs
to the Iowa border region where the coolest air will be, but
otherwise have a mix of rain and rain/snow across the various
forecast periods from Monday night through Wednesday. Did add in
isolated thunder for areas along and south of I-70 owing to some
limited instability present during the afternoon Tuesday.
Cutter
&&
.AVIATION...
winds continue to increase across the terminals with gusts now in
the 25 to 30 knot range, along with widespread low-VFR cloud cover.
Ceilings are now expected to lower into the MVFR category this
evening.
Wind gusts of 30 to locally 40 knots, associated with a secondary
frontal surge and cyclogenesis over northeast Nebraska, will
continue to push southeast this afternoon. RUC13 model has handled
this well, and has the core of winds approaching the terminals just
after 00Z. The speeds measured across the open Plains will diminish
somewhat due to friction and loss of daytime heating, but expect a
very windy evening across the terminals from a 290/300 direction
with a few gusts to near 40 knots possible (especially MCI).
This surge should exit the area after 06Z, although gusty northwest
winds will continue through the remainder of the TAF period. There
is some concern that a brief band of light snow (and MVFR to IFR
conditions) may affect KSTJ/KMCI after 05Z and will continue to
analyze trends to the north for the 00Z TAF cycle.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
MOZ001>004-011>013-020>022-028>030-037-038-043>045-053-054.
KS...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
KSZ025-057-060-102>105.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
339 PM CST THU FEB 23 2012
.DISCUSSION...
As expected, temperatures soared well into the 60s within the warm
sector early this afternoon, even more so than anticipated with the
earlier update. 20Z surface analysis continued to show a complex
frontal structure with two surface lows extending from near Omaha to
near Moberly, with most of the CWA now located in the post-frontal
airmass. Gusty northwest winds will continue to surge east across
the remainder of the CWA through 00Z, accompanied by extensive
cloud cover and steadily falling temperatures.
Two primary concerns as we head into this evening.
1.) Wind. The RUC13 has done an outstanding job with the
placement/intensity of strong winds across Nebraska/Kansas today,
which justifies my earlier concern with respect to the ongoing wind
advisory. Increasing friction (terrain, trees, etc...) over the
eastern Plains coupled with the loss of daytime heating will both
act against a simple advection of upstream conditions into the
western CWA this evening. Already pushed back the start time of the
wind advisory until 6PM, which looks reasonable given the
juxtaposition of the strongest winds immediately south/southeast of
the digging mid-level trough axis. However, considering both minimal
impacts (after the evening commute) and the aforementioned
meteorology, am concerned that the advisory may no longer be
warranted. Still, we may see both sustained speeds and gusts locally
meet criteria (30/45), and will leave the headline active through
this evening. Still will be a windy/blustery evening regardless,
with 60s giving way to 30s by midnight.
2.) Precipitation. Satellite presentation with the mid level trough
over eastern Nebraska continues to improve this afternoon, and
additional deepening is expected as the wave digs southeast along
the Nebraska/Missouri border overnight. A compact area of vigorous
ascent and diabatic cooling immediately behind the trough, acting as
a small scale deformation band, may affect the far northern tier
counties after 11PM into the predawn hours. Given the favorable
dendritic snow growth, it is possible that a period of moderate to
heavy snow could brush the Iowa border counties, resulting in minor
accumulations. Do expect Iowa/Illinois to receive the brunt of this
evening and for now have painted an inch across the northern
counties, but would not be surprised if a short-fused advisory
became necessary overnight. Evening hazardous weather outlook will
be amended as necessary to reflect this impact. If concerns #1 and
#2 overlap at some point tonight, we could have an additional issue
with blowing snow/visibilities impacting travel north of highway 36.
Otherwise, gusty winds and strong cold advection will continue into
tomorrow. Previous forecast already reflected undercutting guidance
on temperatures and made no change there. Cyclonic flow will
maintain cloud cover, especially over the northeast half of the CWA
and would not be surprised to see a few sprinkles/flurries from time
to time either.
Return flow comes back in a hurry Saturday afternoon, with winds
increasing over the western CWA. Should see another 10-15 degree
gradient from northeast Missouri to eastern Kansas.
Bookbinder
Medium Range (Sunday through Thursday)...
The focus for the weather over the latter half of the forecast is on
two features; the first a shortwave due to zip east through the
Northern Plains into the Great Lakes Saturday into Sunday; the
second shortwave of note will then follow on quickly through the
Central Plains Monday night through Wednesday.
Leading shortwave, due to pass through the Plains Saturday/Sunday,
will be starved for moisture. A surface high slowly shifting east
along the Gulf Coast will effectively shut off any return moisture
from the Gulf over the weekend. Couple that observation with the
notable speed with which this shortwave jets east through the
Northern Plains, and precipitation of any form for the weekend looks
like a non-issue. Have kept the forecast dry, and boosted afternoon
highs on the expectation of breezy southwest winds. This should put
temperatures for the last day of the weekend into the 50s to low
60s.
After the passage of the weekend leading shortwave, a second wave is
due to pass through the Central Plains during the beginning of the
work week. Sunday`s shortwave, while dry, will have the ultimate
effect of shoving the baroclinic zone a little father south as weak
high pressure oozes into the Northern Plains, pushing afternoon
highs back down towards normal. This results in the second wave
kicking out across the plains form the Four Corners region, zipping
through the Lower Missouri River Valley. At this point the surface
high along the Gulf Coast will have advected east under the
influence of the progressive flow across the nation, leaving the
Gulf open to allow moisture return which the second shortwave will
be able to tap.
This second system has the potential to be significant weather
maker. While models are in decent enough broad agreement on the
general trend of the shortwave to warrant including likely POPs for
part of Tuesday and Tuesday night, preference on the specifics of
shortwave timing are hedged towards the faster ECMWF and GEM
solutions. GFS is the slowest in ejecting the wave, which seems a
bit off given the progressive flow. Anyhow, have limited snow POPs
to the Iowa border region where the coolest air will be, but
otherwise have a mix of rain and rain/snow across the various
forecast periods from Monday night through Wednesday. Did add in
isolated thunder for areas along and south of I-70 owing to some
limited instability present during the afternoon Tuesday.
Cutter
&&
.AVIATION...
Initial cold front surge moving across the terminals now, so expect
northwest winds to attain a gusty character of 20 to 25 knots within
the next hour where they haven`t already. Otherwise, VFR conditions
and sct-bkn mid clouds will be the rule for the rest of today.
Wind gusts of 40 to locally 50 knots, associated with a secondary
frontal surge and cyclogenesis over northeast Nebraska, will
continue to push southeast this afternoon. High resolution models
like the HRRR/RUC13 both handle this well, and have the core of
winds approaching the terminals just after 00Z. The speeds measured
across the open Plains will diminish somewhat due to friction and
loss of daytime heating, but expect a very windy evening across the
terminals from a 290/300 direction with a few gusts to near 40 knots
possible (especially MCI).
This surge should exit the area after 06Z, although gusty northwest
winds will continue through the remainder of the TAF period.
Upstream broken MVFR ceilings look to be diurnally driven so for now
have not included this in the TAFs.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
MOZ001>004-011>013-020>022-028>030-037-038-043>045-053-054.
KS...WIND ADVISORY FROM 6PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
KSZ025-057-060-102>105.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
921 AM MST THU FEB 23 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
GOING FORECAST LOOKS PRETTY GOOD. SCATTERED SNOW SHOWERS ALREADY
MOVING INTO THE CWA THIS MORNING FROM CANADA. HRRR MODELS
ADVERTISING A BAND OF HEAVIER PRECIP TO SET UP OVER THE SW ZONES
LATER TODAY ALONG AN INSTABILITY AXIS. NAM AND GFS NOT QUITE ON
BOARD WITH THIS...BUT WILL KEEP AN EYE ON IT. JAMBA
PREVIOUS DISCUSSION...
NORTHWEST FLOW ALOFT WILL PREVAIL TODAY AND FRIDAY. TIGHT
SURFACE GRADIENT BETWEEN DEPARTING AND DEEPENING SURFACE LOW TO
THE EAST AND HIGH PRESSURE SYSTEM TO THE WEST WILL BRING GUSTY
NORTHWEST WINDS. UNSTABLE AIRMASS...MOIST ATMOSPHERE AND WEAK
SHORTWAVE WILL AID IN DEVELOPING SNOW SHOWERS THAT WILL BE
SCATTERED ACROSS THE AREA ESPECIALLY THIS AFTERNOON.
THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AS HIGH
PRESSURE SYSTEM MOVES INTO THE AREA. MEANWHILE...A WEAK SHORTWAVE
MOVING THROUGH CENTRAL MONTANA TONIGHT MAY PRODUCE A SNOW SHOWER
IN THE SOUTHWEST ZONES. WILL MENTION A SLIGHT CHANCE FOR NOW.
THE HIGH PRESSURE SYSTEM WILL BRING MAINLY QUIET WEATHER ON FRIDAY
ALTHOUGH A FEW AREAS MAINLY IN THE SOUTH COULD HAVE A LINGERING
SNOW SHOWERS.
UPPER RIDGE PASSES THROUGH THE AREA FRIDAY NIGHT WITH THE NEXT
UPPER TROUGH QUICKLY BEHIND IT ON SATURDAY. A BAND OF OVERRUNNING
SNOW MOVES INTO SOUTHWEST SASKATCHEWAN LATE FRIDAY NIGHT AND
OVERSPREADS SOUTHERN SASKATCHEWAN AND FAR NORTHERN MONTANA DURING
THE DAY SATURDAY. IT WILL BE A COMPLEX SYSTEM WITH ONE LOW
WEAKENING OVER ALBERTA OR SW SASKATCHEWAN ON SATURDAY WHILE
ANOTHER LOW ALONG AN OCCLUDED FRONT DEVELOPS IN WYOMING. THE
SOUTHEAST ZONES APPEAR TO BE IN A DRY SLOT FOR MOST OF SATURDAY.
WILL REDUCE THE CHANCES OF SNOW THERE. AREAS NORTH OF US 2 WILL
LIKELY BE IN THE MAIN SNOW BAND ALTHOUGH MODELS ARE NOT IN PERFECT
AGREEMENT AT THIS POINT. WILL GO CATEGORICAL POPS ALONG THE
CANADIAN BORDER AND GRADUALLY LOWER POPS TO THE SOUTH. FORRESTER
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
A STRONG NORTH PACIFIC STORM SYSTEM WILL SLAM INTO THE CANADIAN
WEST COAST TONIGHT AND MOVE OVER THE DIVIDE AND INTO EASTERN
MONTANA ON SATURDAY. THIS STORM WILL BE IN PROGRESS SATURDAY
EVENING TO BEGIN THE EXTENDED PERIOD. AT 00Z SUNDAY...MODELS PLACE
THE BASE OF THE DEEP UPPER TROUGH OVER THE GREAT BASIN REGION AND
THE LEE SURFACE TROUGH CENTERED OVER NE WYOMING. THERE IS A
SUBSTANTIAL AMOUNT OF PACIFIC MOISTURE BROUGHT BY THIS STORM.
NORTHEAST MONTANA WILL BE ON THE ARCTIC SIDE OF THE COLD FRONT
UNDER THE INVERTED TROUGH. THE FOCUS OF THE WINTER STORM WILL BE
OVER SOUTHERN SASKATCHEWAN AND NEMONT THROUGH SUNDAY MORNING.
THEREFORE THE BULK OF THE SNOW SHOULD BE NORTH OF THE MISSOURI
RIVER WITH A STORM TOTAL RANGING FROM 1 TO 4 INCHES OF SNOW...
BASED ON THE QPF.
BY SUNDAY AFTERNOON THE BASE OF THE UPPER TROUGH WILL HAVE
TRAVELED INTO THE AREAS OF THE DAKOTAS OR MINNESOTA. THERE WILL
STILL BE LINGERING BACK DOOR SNOW SHOWERS LOCALLY WHILE
TEMPERATURES BEGIN TO DROP. A POLAR VORTEX NEAR HUDSON BAY WILL
NUDGE 850MB TEMPERATURES BY 00Z MONDAY TO BE AROUND -16C. EXPECT
SUNDAY NIGHT LOWS TO FALL BELOW 0F AND MONDAY HIGHS TO NOT WARM UP
MUCH ABOVE SUNDAY.
ANOTHER DEEP UPPER LEVEL TROUGH SWINGS INTO THE WESTERN STATES ON
MONDAY. HOWEVER THE MAIN TROUGH ENERGY WILL SWING SOUTH OF
NORTHEAST MONTANA. HOWEVER WITH GENERAL TROUGHINESS... SOME
INSTABILITY INITIATING SHOWERS IS POSSIBLE THROUGH MONDAY NIGHT.
BEHIND THE TROUGH AN UPPER LEVEL RIDGE BEGIN TO BUILD IN OVER THE
PACNW. THIS SHOULD KEEP CONDITIONS DRY THROUGH WEDNESDAY.
TEMPERATURES WILL BEGIN TO TREND BACK TO AROUND NORMAL. THEN BOTH
THE EC AND GFS BRING IN YET ANOTHER UPPER TROUGH INTO THE PACNW ON
WEDNESDAY. THIS WAVE WILL BRING A CHANCE OF SHOWERS THROUGH DAY 8.
SCT
&&
.AVIATION...
SCATTERED FLURRIES AND LIGHT SNOW SHOWERS THIS MORNING MAY BRIEFLY
AFFECT KGGW AND KOLF WITH MVFR CONDITIONS THIS MORNING...THEN MOVE
MORE OVER KSDY AND KGDV LATER THIS AFTERNOON WHERE FLIGHT
CONDITIONS MAY DROP TO NEAR IFR LEVELS DURING THE BRIEF PASSES OF
QUICK HEAVIER SNOW SHOWERS. EXPECT VFR CONDITIONS TO RETURN TO ALL
TAF SITES LATER THIS EVENING. ALSO...AFTERNOON WINDS FROM THE
NORTHWEST WILL INCREASE INTO THE 25G35KT RANGE...RAISING CROSSWIND
CONCERNS FOR RUNWAYS PERPENDICULAR TO THAT. BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
925 PM MST WED FEB 22 2012
.SHORT TERM...VALID FOR THU AND FRI...
WE UPDATED THE FORECAST TO DROP THE HIGH WIND WARNING AND TO ISSUE
A WINTER WEATHER ADVISORY FOR CARTER AND FALLON COUNTIES THROUGH 6
AM MST THU MORNING. AT 04 UTC...A SURFACE LOW IS LOCATED VERY NEAR
BUFFALO SD...WHICH IS NOTABLY SOUTHWEST OF WHERE MOST MODELS WOULD
PLACE IT AT THIS TIME. THIS IS A REFLECTION OF THE LOW-LEVEL FRONT
AND UPPER-LEVEL JET STREAK DRIVING THE SURFACE WAVE BOTH ENDING UP
FURTHER SOUTHWEST THAN ANTICIPATED. BASED ON THE LAST FEW RUC RUNS
AND DOWNSTREAM PRESSURE FALLS CENTERED NEAR WINNER SD AT 04 UTC...
WE FEEL THE PATH OF THIS DYNAMIC WAVE WILL END UP BRINGING IMPACTS
TO SOUTHEASTERN MT OVERNIGHT. THE RUC...AND TO SOME EXTENT THE NEW
00 UTC GFS...CALLS FOR A POTENT AREA OF FRONTOGENESIS NEAR 700 HPA
AND 500-300 Q-VECTOR CONVERGENCE AS FAR WEST AS BAKER AND EKALAKA.
THIS DEFORMATION-ZONE PRECIPITATION COULD AMOUNT TO SEVERAL INCHES
OF SNOW...THOUGH ITS EXACT PLACEMENT IS A LOW-CONFIDENCE ITEM WITH
THE UNCERTAINTY TIED TO THIS DYNAMIC WAVE. EVEN SO...WE STILL HAVE
ENOUGH CONFIDENCE IN THE TRENDS TO CALL FOR 2 TO 5 INCHES OF SNOW
OVER CARTER AND FALLON COUNTIES.
MOISTURE-LADEN NORTHWEST FLOW CONTINUES DELIVERING HEAVY SNOW INTO
THE MOUNTAINS...SO WE WILL CONTINUE WITH THE GOING WARNINGS THERE.
WE STILL HAVE SOME CONCERN FOR THE BAND OF SNOW MOVING THROUGH RED
LODGE...BUT TRENDS SUGGEST IT WILL DIMINISH ENOUGH TO KEEP US FROM
NEEDING AN ADVISORY. THAT WILL MAINLY BE TIED TO LOW-LEVEL FLOW IN
THE FOOTHILLS TURNING MORE WESTERLY THOUGH...SO IF WE DO NOT START
SEEING THAT HAPPEN IN THE NEXT FEW HOURS A SHORT-FUSE HEADLINE MAY
STILL BE REQUIRED.
FINALLY...DESPITE A 3-HOUR SURFACE PRESSURE RISE ON THE ORDER OF 8
HPA DROPPING THROUGH SOUTH CENTRAL MT...WINDS ALOFT HAVE DECREASED
ENOUGH TO BRING AN END TO THE HIGH WINDS. WE COULD END UP CLOSE TO
CRITERIA IN SOUTHEASTERN MT AND NEAR SHERIDAN WY FOR A WHILE...BUT
THIS THREAT WAS NOT ENOUGH TO KEEP THE WARNING GOING. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MEDIUM RANGE MODELS CONTINUE TO INDICATE A MODERATION IN
TEMPERATURES FOR SATURDAY THROUGH MONDAY. BOTH THE GFS AND ECMWF
ARE IN GOOD AGREEMENT SATURDAY IN SLOWING THE ARRIVAL OF THE COLD
FRONT INTO THE EARLY EVENING HOURS. SOUTHWEST FLOW ALOFT AND AT
THE SURFACE AHEAD OF THE FRONT WILL ALLOW FOR THE POSSIBILITY OF
DOWNSLOPE WINDS FROM BILLINGS WESTWARD RESULTING IN WARMER
TEMPERATURES THAN PREVIOUSLY ANTICIPATED. AS A RESULT OF THE
SLOWER ARRIVAL OF THE FRONT...HAVE SCALED BACK POP CHANCES
SOMEWHAT FOR THE DAY BUT KEPT HIGHER CHANCES FOR THE EVENING AND
OVERNIGHT HOURS. STILL LOOKS TO BE A RAIN AND SNOW SHOWER TYPE OF
PRECIP AHEAD AND ALONG THE FRONT CHANGING TO ALL SNOW BEHIND THE
FRONT SATURDAY NIGHT AS COLDER AIR FILTERS INTO THE AREA. HAVE
MODERATED SATURDAY NIGHT AND SUNDAY NIGHT LOWS SEVERAL
DEGREES...ESPECIALLY SATURDAY NIGHT...AS WELL AS WARMED
TEMPERATURES UP SEVERAL DEGREES FOR SUNDAY AND MONDAY. CAN`T
REALLY CALL THIS AN ARCTIC FRONT ANYMORE GIVEN THE FACT OVERNIGHT
LOWS SATURDAY NIGHT ARE ONLY EXPECTED IN THE TEENS WITH HIGHS IN
THE 20S FOR SUNDAY. HOWEVER...LOWER 20S IS STILL ABOUT 20 DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. GUIDANCE IS ACTUALLY GIVING
THE AREA 40S FOR HIGHS SATURDAY AND SUNDAY WITH UPPER 30S MONDAY.
DID NOT WARM READINGS UP THIS MUCH BUT IF GUIDANCE CONTINUES THIS
TREND READINGS MAY HAVE TO BE NUDGED HIGHER WITH LATER SHIFTS.
OVERALL PATTERN CONTINUES TO LOOK UNSETTLED FOR THE REMAINDER OF
NEXT WEEK WITH TEMPERATURES SLIGHTLY BELOW NORMAL. HOOLEY
&&
.AVIATION...
SCATTERED RAIN AND SNOW SHOWERS WILL TURN OVER TO ALL SNOW LATE
THIS EVENING. AREAS EAST OF A MILES CITY TO BROADUS LINE WILL SEE
PERIODS OF IFR OR LOWER CONDITIONS LATE TONIGHT INTO TOMORROW
MORNING DUE TO SNOWFALL. AREAS IN THE FOOTHILLS AND MOUNTAINS WILL
ALSO SEE PERIODS OF IFR OR LOWER CONDITIONS WITH SNOWFALL AND
STRONG WINDS PRODUCING BLOWING SNOW. WINDS OVER MOST LOCATIONS
WILL DIMINISH THROUGH THE NIGHT...THOUGH OCCASIONAL GUSTS AROUND
40 KTS WILL BE POSSIBLE THROUGH AT LEAST MIDNIGHT AT ALL TAF
LOCATIONS. EXPECT CONDITIONS TO IMPROVE FROM NORTH TO SOUTH DURING
THE EARLY MORNING HOURS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 028/039 020/036 022/040 018/023 009/024 011/035 016/039
43/W 21/B 13/W 44/J 22/J 11/B 11/B
LVM 022/034 013/033 021/038 016/022 007/023 009/034 014/037
43/J 21/E 24/J 44/J 23/J 21/B 11/N
HDN 026/040 020/040 019/042 020/023 012/024 012/035 018/041
73/W 31/B 13/W 44/J 22/J 11/B 01/B
MLS 026/037 020/035 018/038 018/020 006/021 008/032 016/037
83/J 32/J 13/J 44/J 22/J 11/B 00/B
4BQ 024/037 018/037 017/044 020/025 011/025 008/034 018/039
73/J 42/J 12/J 44/J 21/E 11/B 00/U
BHK 025/031 016/030 014/035 019/019 005/020 008/031 017/036
+4/J 12/J 12/J 44/J 21/E 11/B 11/U
SHR 026/035 016/035 017/043 021/024 008/025 010/034 019/038
75/J 22/J 13/W 44/J 22/J 21/B 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST THURSDAY FOR
ZONES 33-37.
WINTER STORM WARNING IN EFFECT UNTIL 5 AM MST THURSDAY FOR
ZONE 67.
WY...WINTER STORM WARNING IN EFFECT UNTIL 5 AM MST THURSDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
828 AM CST THU FEB 23 2012
.UPDATE...STRONG WINDS ALOFT ARE MIXING TO THE SFC THIS MORNING
ACROSS NORTH CENTRAL NEBRASKA. SUSTAINED WINDS ARE NEARING 40 MPH
WITH GUSTS TO 55 MPH. HAVE UPGRADED THE WIND ADVISORY FOR POSSIBLE
SUSTAINED WINDS OVER 40 MPH WITH GUSTS TO 60 MPH.
&&
.PREV DISCUSSION... /ISSUED 747 AM CST THU FEB 23 2012/
UPDATE...
WIND IN NORTH CENTRAL NEBRASKA IS HIGHER THAN THE EARLIER
FORECAST INDICATED. ALSO...PROFILER DATA FROM THE WSR-88 AND THE
NETWORK SHOWS WIND 60KT OR GREATER AT 1000M AGL.
PREV DISCUSSION... /ISSUED 544 AM CST THU FEB 23 2012/
AVIATION...AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL
AND NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET
AGL AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 6 PM CST
/5 PM MST/ THIS EVENING FOR
NEZ004-007-009-010-022-023-027>029-035-036-056>059-069>071.
HIGH WIND WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ005-006-008-024>026-037-038-094.
&&
$$
DISCUSSION...BROOKS
UPDATE...TAYLOR
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
747 AM CST THU FEB 23 2012
.UPDATE...
WIND IN NORTH CENTRAL NEBRASKA IS HIGHER THAN THE EARLIER
FORECAST INDICATED. ALSO...PROFILER DATA FROM THE WSR-88 AND THE
NETWORK SHOWS WIND 60KT OR GREATER AT 1000M AGL.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST THU FEB 23 2012/
AVIATION...
AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL AND
NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET AGL
AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING
FOR NEZ004>010-022>029-035>038-056>059069>071-094
&&
$$
SHORT TERM UPDATE...SPRINGER
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
544 AM CST THU FEB 23 2012
.AVIATION...
AS A STORM SYSTEM MAKES ITS WAY ACROSS NORTH CENTRAL AND
NORTHEAST NEBRASKA...CEILINGS AND VISIBILITY IN CENTRAL AND
SOUTHWEST NEBRASKA...INCLUDING MHN...OGA...IML...LBF AND BBW...ARE
EXPECTED TO BE AT OR ABOVE 3500 FEET AGL AND 5SM. IN NORTH CENTRAL
NEBRASKA...INCLUDING ONL...BUB...ANW...TIF AND VTN...PREVAILING
CONDITIONS ARE LIKELY TO LOWER TO 1000-2000 FEET AGL WITH 3-5SM
VISIBILITY IN LIGHT SNOW. OCCASIONAL REDUCTIONS TO 500-900 FEET AGL
AND LESS THAN 1SM ARE POSSIBLE IN SNOW AND BLOWING SNOW AS THE
PRECIPITATION AREA MOVES ACROSS NORTH CENTRAL NEBRASKA.
WIND WILL INCREASE BY 15Z OVER THE ENTIRE AREA WITH DIRECTION
310-340 AT 25-35G40-45KT. WIND IS EXPECTED TO SUBSIDE TO
20-25G30-35KT BY 22Z AND TO LESS THAN 15KT AFTER 00Z.
&&
.PREV DISCUSSION... /ISSUED 348 AM CST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>029-035>038-056>059-069>071-094.
&&
$$
SHORT TERM/EXTENDED...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
348 AM CST THU FEB 23 2012
.SHORT TERM...TODAY THROUGH SATURDAY
FORECAST FOCUS THROUGH THIS PERIOD IS ON WINDS AND SNOW POTENTIAL
TODAY.
AT 08Z...WATER VAPOR IMAGERY SHOWED A LARGE RIDGE OVER THE EASTERN
PACIFIC WITH TROUGHING ACROSS THE EASTERN HALF OF THE
CONUS...LEAVING THE CENTRAL STATES IN NORTHWEST FLOW. IN THIS
FLOW...A SHORTWAVE TROUGH WAS SEEN OVER SOUTHEAST IDAHO...WHILE
THE WAVE OF IMMEDIATE CONCERN FOR THE LOCAL AREA WAS OVER EASTERN
MONTANA INTO WESTERN NORTH DAKOTA AND NORTHWEST SOUTH DAKOTA. AT
THE SURFACE...THE COLD FRONT HAD PASSED ACROSS THE FORECAST AREA
AND WAS LOCATED FROM THE SURFACE LOW IN SOUTH CENTRAL SOUTH
DAKOTA THROUGH KONL TO KHDE TO KHLC THEN WEST INTO EAST CENTRAL
COLORADO. THE PRESSURE GRADIENT BEHIND THE FRONT WAS TIGHTENING
WITH WINDS ON THE INCREASE OVER WESTERN SOUTH DAKOTA AND THE
NEBRASKA PANHANDLE. TEMPERATURES REMAINED IN THE MID TO UPPER 30S
IN MOST LOCATIONS...HOWEVER LOOKING UPSTREAM BEHIND THE
FRONT...THINGS WERE BEGINNING TO SLOWLY COOL DOWN. LOOKING AT
RADAR...A LARGE VORTEX OF PRECIPITATION WAS SPINNING AROUND THE
700MB LOW OVER SOUTH DAKOTA. THE WESTERN PORTION OF THIS WAS OVER
THE BLACK HILLS AND THE WHOLE AREA WAS SLOWLY MOVING TO THE
SOUTHEAST. NOT MUCH WAS BEING REPORTED WITH THIS AREA OF
PRECIPITATION THOUGH...WITH JUST LIGHT SNOW WITH NO ACCUMULATIONS
YET AT KRAP.
THE LATEST RUC WOULD TAKE THE LOW OVER SOUTH DAKOTA SOUTHEAST
ACROSS NORTHEAST CHERRY AND KEYA PAHA COUNTIES THROUGH GARFIELD
AND WHEELER COUNTIES AND THEN CONTINUING SOUTHEAST ACROSS GID/S
FORECAST AREA. THE TIGHTEST PRESSURE GRADIENT SHOULD BE JUST TO
THE WEST OF THE LOW...SO THIS TRACK WOULD SUGGEST THE STRONGEST
WINDS WOULD BE ACROSS THE CENTRAL AND SOUTHEASTERN PARTS OF THE
FORECAST AREA THROUGH THE DAY. THERE REMAINS QUESTION OF HOW
STRONG THESE WINDS WILL BE. MAV GUIDANCE SEEMS TO BE TOO HIGH
GIVING 44KT SUSTAINED WINDS AT KBBW AND 41KT SUSTAINED AT KLBF.
SO ALTHOUGH EXPECTING HIGH WINDS...DIDN/T GO AS HIGH AS THAT
GUIDANCE. CURRENTLY THINKING TODAY/S WINDS WILL BE A HIGH END
ADVISORY...BUT WILL NEED TO KEEP AN EYE ON THINGS AS KRAP /WHICH
IS CURRENTLY JUST WEST OF THE LOW HAS HAD A PEAK GUST TO 54KTS
ALREADY. LUCKILY...WINDS ALOFT LOOK TO DECREASE THROUGH THE DAY AS
HIGHEST MIXING IS ACHIEVED AS TH 925MB AND 850MB WINDS FROM THE
KUNR VWP WERE AT 50KTS AND 55KTS RESPECTIVELY...WHILE BUFKIT
SOUNDINGS FROM THE NAM SHOWED UP TO 65KTS AROUND 800MB. AS THE
WINDS WERE ALREADY COMING UP...DID START THE WIND ADVISORY EARLY
/10Z FOR THE NORTHWEST TWO-THIRDS OF THE FORECAST AREA/ WITH THE
SOUTHEAST TIER BEGINNING NOW AT 14Z RATHER THAN 15Z. THE PRESSURE
GRADIENT WILL LESSEN THIS AFTERNOON...BUT WITH VERY STEEP LAPSE RATES
WITH THE COLD AIR ADVECTION INFLUENCING THE MIXING POTENTIAL...WILL
CONTINUE TO SEE BREEZY CONDITIONS THROUGH THE AFTERNOON.
IN TERMS OF THE SNOW...THE PRECIPITATION OVER THE BLACK HILLS
SHOULD ROTATE SOUTHEAST INTO NORTH CENTRAL NEBRASKA AND CONTINUE
TO THE SOUTHEAST TODAY. DON/T HAVE A GOOD HANDLE ON HOW MUCH QPF
WILL BE WITH THIS AS MODELS RANGE FROM A FEW HUNDREDTHS TO AROUND
A QUARTER INCH. BELIEVE THE LARGER AMOUNTS MAY BE A BIT HIGH DUE
TO WHAT IS CURRENTLY SEEN ON RADAR AND WITH ONLY A FEW STATIONS
REPORTING PRECIPITATION SO DIDN/T GO THAT ROBUST IN THE FORECAST.
CURRENTLY HAVE UP TO 2 INCHES OF SNOW ACCUMULATION THROUGH THE DAY
FROM MERRIMAN TO THEDFORD TO BROKEN BOW. DID KEEP THE
PRECIPITATION TYPE AS SNOW COLD AIR WILL CONTINUE TO PUSH SOUTH
KEEPING TEMPERATURES IN THESE AREAS FROM RISING MUCH AND WITH
TEMPERATURES ALOFT COOLING...PRECIPITATION WILL FALL AS
SNOW...WHILE IT MAY MELT UPON REACHING THE GROUND. ONE CONCERN
WILL BE IF THIS SNOW WILL HAVE ANY IMPACT DUE TO THE WINDS. EVEN
THOUGH IT WILL BE LIGHT SNOW SHOWERS...WINDS BLOWING AT 40 TO 50
MPH COULD CAUSE REDUCED VISIBILITIES. HELD OFF ON PUTTING OUT ANY
WINTER WEATHER HEADLINES BECAUSE OF THE LIGHTER SNOW AMOUNTS
EXPECTED BUT WILL PUT OUT A SPECIAL WEATHER STATEMENT TO INFORM
USERS OF POTENTIAL IMPACTS.
TEMPERATURES WILL STAY BELOW NORMAL FOR FRIDAY WITH HIGHS ONLY IN
THE MID 30S TO LOW 40S AS NORTHWEST FLOW STAYS IN PLACE KEEPING
THE COOLER AIR OVER THE AREA. LAPSE RATES WILL REMAIN STEEP DUE TO
THE COLDER AIR ALOFT AND AS A WEAK SHORTWAVE TROUGH PASSES ACROSS
THE AREA...MAY SEE SOME SCATTERED SNOW SHOWERS THROUGH THE DAY.
DON/T EXPECT ANYTHING WIDESPREAD OR MUCH FOR ACCUMULATIONS...BUT
FELT IT DEEMED ADDING IN A SLIGHT CHANCE.
RIDGING BUILDS IN FOR SATURDAY...AND WITH MODELS SHOWING ABUNDANT
DRY AIR...SHOULD SEE QUITE A BIT OF SUNSHINE. TEMPERATURES WILL
WARM AS SOUTHERLY SURFACE FLOW BRINGS WARMER AIR NORTHWARD SO
LOOKING AT TEMPERATURES RISING TO ABOVE NORMAL VALUES WHICH ARE LOW
TO MID 40S.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
STILL LOOKS LIKE A RATHER SIGNIFICANT SYSTEM WILL PASS ACROSS THE
NORTHERN PLAINS ON SUNDAY. THE TREND SINCE YESTERDAY DOES LOOK TO
BE A BIT TO THE NORTH WITH THE UPPER LEVEL SYSTEM SO THE MAJORITY
OF THE SNOW WILL FALL ACROSS THE DAKOTAS. THE OPERATIONAL GFS
SOLUTION IS ONE OF THE MORE SOUTHERLY SOLUTIONS OF THE ENSEMBLE
MEMBERS...WITH THE MEAN BEING CLOSER TO THE ECMWF. BUT TO LEAVE A
CHANCE FOR A SOUTHERLY SHIFT...SLIGHT CHANCES FOR SNOW LOOK TO BE
GOOD FOR SUNDAY AND SUNDAY NIGHT ACROSS NORTHERN NEBRASKA. THE
SURFACE LOW IS NOW LOOKING LIKE IT WILL MOVE ACROSS SOUTH
DAKOTA...WITH THE COLD FRONT QUICKLY MOVING ACROSS THE FORECAST
AREA BY MID MORNING ON SUNDAY. LOOKS LIKE BREEZY NORTHWEST WINDS
ACROSS NEBRASKA...WITH THE MORE ROBUST WINDS JUST TO THE WEST OF
THE LOW OVER THE DAKOTAS WHERE THE PRESSURE GRADIENT WILL BE
TIGHTEST. ALSO...WITH THE NORTHERLY SHIFT...TEMPERATURES MAY STAY
A BIT WARMER ON SUNDAY. STILL EXPECTING BELOW NORMAL FOR
HIGHS...BUT WITH THIS TRACK...WOULD EXPECT HIGHS IN THE MID 30S TO
MID 40S RATHER THAN MID 20S TO 40 DEGREES AS IT LOOKS TO THE
NORTH. HIGH PRESSURE BUILDS SOUTH FOR MONDAY...WITH DRY
CONDITIONS...BUT COLDER AS 850MB TEMPERATURES STAY BELOW 0C ACROSS
THE ENTIRE FORECAST AREA. THE GFS HAS 850MB TEMPERATURES OVER
NORTHERN NEBRASKA AT -7C TO -9C. MEANWHILE...ANOTHER SYSTEM LOOKS
TO DIG TOWARDS THE FOUR CORNERS WITH A SURFACE LOW DEVELOPING
OVER NEW MEXICO MONDAY NIGHT. THE WARM FRONT WITH THIS SYSTEM IS
CURRENTLY PROJECTED TO LIFT INTO KANSAS MONDAY NIGHT...WITH
MOISTURE AND LIFT OVERRUNNING THE FRONT BRINGING PRECIPITATION
INTO NEBRASKA. THE GFS BREAKS THIS PRECIPITATION OUT BY 06Z WHILE
THE ECMWF IS SLIGHTLY DELAYED. SURFACE FEATURES ARE FAIRLY
SIMILAR...BUT THE UPPER LEVEL TROUGH IS MUCH MORE AMPLIFIED AND
POSITIVELY TILTED. THE ECMWF DOES SHOW STRONG ISENTROPIC LIFT IN
THE 285K TO 295K SURFACES...AS WELL AS GOOD MOISTURE TRANSPORT
INTO SOUTHWEST NEBRASKA ON THE 285K SURFACE. SO WHEREVER THE
SYSTEM TRACKS...THERE IS CERTAINLY POTENTIAL FOR SOME DECENT
PRECIPITATION. AT THIS POINT WILL STICK TO THE CONSENSUS OUTPUT AS
PLENTY CAN CHANGE WITH THIS SYSTEM OVER THE NEXT WEEK.
&&
.AVIATION...
A POWERFUL WINTER CYCLONE WILL RAPIDLY TRACK THROUGH THE MISSOURI
BASIN TODAY. LIFR/IFR/MVFR IN SN...BLSN AND LOW CIGS SHOULD DEVELOP
ALONG HIGHWAY 20 AROUND 12Z AND CONTINUE THROUGH 21Z. MVFR IS
EXPECTED ALONG AND EAST OF HIGHWAY 183 21Z-03Z. VFR IS EXPECTED BY
03Z ACROSS THE ENTIRE FCST AREA.
ELSEWHERE...VFR/MVFR IS EXPECTED TODAY AND TONIGHT. FLIGHT
CONDITIONS WILL IMPROVE SOUTHWARD FROM HIGHWAY 20.
WINDS INCREASE TO 32030G45KT AROUND 12Z AND CONTINUE STRONG THRU 23Z
TODAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY FROM 8 AM CST /7
AM MST/ THIS MORNING TO 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ028-029-038-058-059-069>071.
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>010-022>027-035>037-056-057-094.
&&
$$
SHORT/LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
437 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS EARLY THIS THURSDAY
MORNING WILL BE THE MAIN WEATHER MAKER FOR OUR AREA DURING THIS
PERIOD. THE MODELS GENERALLY AGREE THAT THIS SYSTEM WILL LIFT MOVE
ACROSS THE MIDWEST TONIGHT...THEN TRACK NORTHEAST ACROSS NEW YORK
FRIDAY...REACHING THE ST LAWRENCE RIVER VALLEY LATE IN THE DAY.
WHILE THE OVERALL TRACKS OF THE SURFACE LOW ARE SIMILAR...THERE ARE
DIFFERENCES IN THE MODEL THERMAL PROFILES WHICH WILL IMPACT PCPN
TYPE...ESPECIALLY FOR AREAS EAST OF LAKE ONTARIO. THESE DIFFERENCES
SEEM TO BE RELATED TO THE FORECAST PATHS OF THE 850 MB LOWS. THE GFS
KEEPS THE 850 MB LOW A LITTLE FARTHER TO THE WEST THAN THE NAM. AS A
RESULT...THE GFS DEPICTS SLIGHTLY WARMER AIR SURGING NORTH ACROSS
THE FINGER LAKES AND NORTH COUNTRY DURING THE DAY. THIS SCENARIO
WOULD ALLOW FOR MORE OF A MIX OF SNOW AND SLEET...BEFORE A
CHANGEOVER TO ALL SNOW TAKES PLACE LATER IN THE AFTERNOON. THE
COOLER NAM SOLUTION FAVORS MORE SNOW ACROSS THIS AREA. BASED ON HOW
BOTH MODELS TRACK THE 850 LOW ACROSS WESTERN DURING DURING THE
MORNING...THE GFS SOLUTIONS SEEMS A LITTLE MORE REASONABLE.
AREAS WEST OF THE NORTH COUNTRY WILL LIKELY SEE MORE RAIN BEFORE THE
CHANGEOVER TO ALL SNOW TAKES PLACE DURING THE AFTERNOON AS COLDER
AIR WORKS IN BEHIND THE DEPARTING LOW. THE MAIN `FLY IN THE
OINTMENT` IS THAT A DEEPENING UPPER LEVEL LOW AND EMBEDDED SHORT
WAVE WILL BE CROSSING THE CWA DURING THE MORNING. DYNAMIC COOLING
ASSOCIATED WITH THE UPPER LEVEL TROUGH MAY COOL THE ATMOSPHERE
THROUGH A DEEP ENOUGH LAYER TO CAUSE A QUICKER CHANGEOVER TO ALL
SNOW. BASED ON ALL THE UNCERTAINTIES REGARDING RESULTING THERMAL
PROFILES...WE WILL HOLD OFF ON ISSUING ANY WINTER WEATHER
ADVISORIES.
THE FORECAST TRACK OF THE SURFACE LOW COULD ALSO RESULT IN RATHER
WINDY CONDITIONS ON FRIDAY...ESPECIALLY ACROSS WESTERN NEW YORK
WHERE STRENGTHENING WEST TO SOUTHWEST WINDS WILL SET UP BEHIND THE
DEPARTING LOW DURING THE LATE MORNING AND AFTERNOON.
AS COLDER AIR FILTERS INTO THE REGION FRIDAY NIGHT AND WRAP AROUND
MOISTURE DEEPENS...SYNOPTIC SNOW WILL BECOME MORE WIDESPREAD. LATER
FRIDAY NIGHT...850MB TEMPERATURES DROP TO ABOUT -11C. WITH FAIRLY
UNIFORM WEST-NORTHWEST FLOW ACROSS THE LAKES...WE SHOULD SEE A
DECENT SETUP FOR LAKE EFFECT SNOWS...PARTICULARLY ACROSS THE
SOUTHEAST SNOWBELTS. THE COLDER AIR ADVECTING INTO THE REGION WILL
ALSO ALLOW TEMPERATURES TO DROP BACK INTO SOMETHING APPROACHING
NORMAL FOR THIS TIME OF YEAR WITH LOWS IN THE 20S FRIDAY NIGHT AND
HIGHS IN THE UPPER 20S TO LOW 30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES SATURDAY NIGHT...ALLOWING THE LAKE EFFECT SNOWS TO WIND DOWN.
EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP WHERE THERE IS
CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY WHERE SUB-ZERO
TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A FRONTAL BOUNDARY WILL CONTINUE TO EXIT TO THE EAST THROUGH THIS
MORNING. WHILE DRIER AIR WILL WORK INTO THE REGION ALOFT...QUITE A
BIT OF LOW LEVEL MOISTURE WILL LINGER INTO THIS MORNING. THIS WILL
RESULT IN SOME PATCHY IFR OR LOWER CONDITIONS. ANY SIGNIFICANT CLEARING
WILL LIKELY BE FOLLOWED BY FOG DEVELOPMENT...AND EVEN LOWER
CIGS/VSBY. THIS SHOULD IMPROVE THIS MORNING...AS DRIER AIR MIXES
DOWN.
AFTER THIS...EXPECT LARGELY VFR CONDITIONS FOR MUCH OF TODAY INTO
THIS EVENING. THEN LOWERING CIGS/VSBY AS RAIN AND SNOW MOVE IN
FROM SOUTH TO NORTH THIS EVENING.
OUTLOOK... FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP/WOOD
LONG TERM...TJP/WOOD
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
429 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS EARLY THIS THURSDAY
MORNING WILL BE THE MAIN WEATHER MAKER FOR OUR AREA DURING THIS
PERIOD. THE MODELS GENERALLY AGREE THAT THIS SYSTEM WILL LIFT MOVE
ACROSS THE MIDWEST TONIGHT...THEN TRACK NORTHEAST ACROSS NEW YORK
FRIDAY...REACHING THE ST LAWRENCE RIVER VALLEY LATE IN THE DAY.
WHILE THE OVERALL TRACKS OF THE SURFACE LOW ARE SIMILAR...THERE ARE
DIFFERENCES IN THE MODEL THERMAL PROFILES WHICH WILL IMPACT PCPN
TYPE...ESPECIALLY FOR AREAS EAST OF LAKE ONTARIO. THESE DIFFERENCES
SEEM TO BE RELATED TO THE FORECAST PATHS OF THE 850 MB LOWS. THE GFS
KEEPS THE 850 MB LOW A LITTLE FARTHER TO THE WEST THAN THE NAM. AS A
RESULT...THE GFS DEPICTS SLIGHTLY WARMER AIR SURGING NORTH ACROSS
THE FINGER LAKES AND NORTH COUNTRY DURING THE DAY. THIS SCENARIO
WOULD ALLOW FOR MORE OF A MIX OF SNOW AND SLEET...BEFORE A
CHANGEOVER TO ALL SNOW TAKES PLACE LATER IN THE AFTERNOON. THE
COOLER NAM SOLUTION FAVORS MORE SNOW ACROSS THIS AREA. BASED ON HOW
BOTH MODELS TRACK THE 850 LOW ACROSS WESTERN DURING DURING THE
MORNING...THE GFS SOLUTIONS SEEMS A LITTLE MORE REASONABLE.
AREAS WEST OF THE NORTH COUNTRY WILL LIKELY SEE MORE RAIN BEFORE THE
CHANGEOVER TO ALL SNOW TAKES PLACE DURING THE AFTERNOON AS COLDER
AIR WORKS IN BEHIND THE DEPARTING LOW. THE MAIN `FLY IN THE
OINTMENT` IS THAT A DEEPENING UPPER LEVEL LOW AND EMBEDDED SHORT
WAVE WILL BE CROSSING THE CWA DURING THE MORNING. DYNAMIC COOLING
ASSOCIATED WITH THE UPPER LEVEL TROUGH MAY COOL THE ATMOSPHERE
THROUGH A DEEP ENOUGH LAYER TO CAUSE A QUICKER CHANGEOVER TO ALL
SNOW. BASED ON ALL THE UNCERTAINTIES REGARDING RESULTING THERMAL
PROFILES...WE WILL HOLD OFF ON ISSUING ANY WINTER WEATHER
ADVISORIES.
THE FORECAST TRACK OF THE SURFACE LOW COULD ALSO RESULT IN RATHER
WINDY CONDITIONS ON FRIDAY...ESPECIALLY ACROSS WESTERN NEW YORK
WHERE STRENGTHENING WEST TO SOUTHWEST WINDS WILL SET UP BEHIND THE
DEPARTING LOW DURING THE LATE MORNING AND AFTERNOON.
AS COLDER AIR FILTERS INTO THE REGION FRIDAY NIGHT AND WRAP AROUND
MOISTURE DEEPENS...SYNOPTIC SNOW WILL BECOME MORE WIDESPREAD. LATER
FRIDAY NIGHT...850MB TEMPERATURES DROP TO ABOUT -11C. WITH FAIRLY
UNIFORM WEST-NORTHWEST FLOW ACROSS THE LAKES...WE SHOULD SEE A
DECENT SETUP FOR LAKE EFFECT SNOWS...PARTICULARLY ACROSS THE
SOUTHEAST SNOWBELTS. THE COLDER AIR ADVECTING INTO THE REGION WILL
ALSO ALLOW TEMPERATURES TO DROP BACK INTO SOMETHING APPROACHING
NORMAL FOR THIS TIME OF YEAR WITH LOWS IN THE 20S FRIDAY NIGHT AND
HIGHS IN THE UPPER 20S TO LOW 30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES SATURDAY NIGHT...ALLOWING THE LAKE EFFECT SNOWS TO WIND DOWN.
EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP WHERE THERE IS
CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY WHERE SUB-ZERO
TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
A COLD FRONT STALLED ACROSS WESTERN NEW YORK ALONG THE SOUTHERN LAKE
SHORES SOUTHWEST INTO NORTHERN OH IS THE FOCUS FOR SOME LINGERING
SNOW EARLY THIS MORNING. TREND OF REGIONAL RADAR MOSAIC LOOP HAS
BACK EDGE OF SNOW MOVING ACROSS KBUF/KIAG/KJHW NEAR 06Z...FOR KROC
07Z AND KART BY 08-09Z. IFR OR LOWER CIGS MAY LINGER A BIT AFTER
THE SNOW ENDS...BUT WILL EVENTUALLY IMPROVE WITH TIME. WATER VAPOR
IMAGERY SHOWING SOME DRY AIR FILLING IN BEHIND THE BACK EDGE OF
SNOW AS UPPER SHORTWAVE PASSES EAST OF THE OH VALLEY.
DRIER AIR INFILTRATING BEHIND THE SNOW LATER THIS MORNING WILL BRING
VFR CONDITIONS BACK TO THE AREA AFTER 14Z...BUT ANOTHER SYSTEM WILL
ARRIVE FOR THURSDAY NIGHT. NAM/GFS/SREF MODELS ALL SHOW RAIN AND
LOWERING CIGS APPROACHING THE SOUTHERN TIER AND FAR WESTERN NY TOWARD
THE END OF THE TAF PERIOD.
OUTLOOK...
FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP/WOOD
LONG TERM...TJP/WOOD
AVIATION...APFFEL/SMITH
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
336 AM EST THU FEB 23 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION TODAY. LOW
PRESSURE WILL LIFT TOWARD THE EASTERN LAKES TONIGHT...INTENSIFYING
AS IT TRACKS ACROSS NEW ENGLAND FRIDAY NIGHT. THIS WILL BRING SOME
RAIN AND SNOW TO THE REGION TONIGHT INTO FRIDAY. AS THE LOW EXITS
INTO THE MARITIMES...IT WILL BRING COLDER AIR AND LINGERING SNOW
SHOWERS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THE EARLY MORNING HOURS...LINGERING AREAS OF SNOW WILL EXIT
EAST. SNOW SHOULD BE DONE IN MOST AREAS...WITH ALL ACCUMULATING SNOW
EXPECTED TO BE DONE BY DAYBREAK. HRRR MODEL HAS SNOW BANDS WELL
FORECAST...WITH THIS THE PREFERRED MODEL IN THE ULTRA-SHORT TERM.
AFTER THIS...WEAK SURFACE HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE REGION. AN UPPER LEVEL DISTURBANCE EMBEDDED IN THE 500 MB FLOW
WILL PASS. WHILE IT APPEARS TO DRY FOR THIS FEATURE TO CAUSE ANY
PRECIPITATION...IT WILL LIKELY CAUSE CLOUDS TO LINGER FOR MUCH OF THE
MORNING HOURS. OTHERWISE...TEMPERATURES SHOULD CLIMB TO THE LOWER
40S IN MOST LOCATIONS...IN THE UPPER 30S ACROSS HIGHER TERRAIN AND
EAST OF LAKE ONTARIO.
THINGS GET A BIT MORE COMPLEX FOR TONIGHT AS LOW PRESSURE IS
FORECAST TO TRACK FROM THE OHIO VALLEY TOWARD THE REGION. MODEL
GUIDANCE IS IN POOR AGREEMENT FOR THIS TIMEFRAME...WITH SIGNIFICANT
MODEL DIFFERENCES IN STRENGTH AND TRACK OF THE LOW LEADING TO
DIFFERING THERMAL PROFILE FORECASTS. FOR EXAMPLE...THE LATEST RUN OF
THE EUROPEAN HAS A 998 MB LOW NEAR EASTERN OHIO ON 12Z FRIDAY
MORNING...WHILE THE NAM HAS A 985 MB LOW ACROSS LAKE ERIE. GIVEN THE
SPREAD OF SOLUTIONS...CONFIDENCE REMAINS LOWER THAN NORMAL FOR
TONIGHTS FORECAST. CLIMATOLOGICALLY SPEAKING...THE FAVORED TRACK FOR
THE SURFACE LOW WOULD BE ACROSS LAKE ERIE/ONTARIO. THIS IS BEST
REPRESENTED BY THE NAM/GFS/SREF SOLUTIONS...THOUGH THESE MODELS STILL
DIFFER ON HOW QUICKLY WARM AIR ALOFT WILL BUILD IN. FEEL THE MOST
LIKELY SOLUTION IS REFLECTED BY A NAM/GFS/SREF BLEND IN TRACK AND
TEMPERATURES ALOFT.
SO FOR TONIGHT...A BROAD AREA OF WARM AIR ADVECTION PRECIPITATION
WILL LIFT TOWARD THE REGION FROM THE SOUTH. DESPITE MODEL
DIFFERENCES...THERE IS GENERAL MODEL AGREEMENT ON THIS...WITH HIGH
CONFIDENCE IN MEASURABLE PRECIPITATION SOUTH OF LAKE ONTARIO.
PRECIPITATION WILL LIKELY START AS A MIX OF RAIN AND SNOW IN MOST
AREAS. PRECIPITATION SHOULD START DURING THE EVENING HOURS SOUTH OF
LAKE ONTARIO...AND AFTER MIDNIGHT ACROSS AND EAST OF THE LAKE...AND
TOWARD DAYBREAK WATERTOWN NORTHWARD. HERE IS WHERE THERE ARE
SIGNIFICANT MODEL DIFFERENCES...BUT DO FEEL AT LEAST A COUPLE HOURS
OF MODERATE SNOWFALL IS LIKELY IN MOST LOCATIONS. WEST OF
ROCHESTER...IT LOOKS LIKE 1 TO 3 INCHES OF SNOW BEFORE THE
CHANGEOVER TO RAIN. EAST OF ROCHESTER...IT WILL BE FURTHER FROM THE
LOW...WITH THERMAL PROFILES SUGGESTING THAT COLD AIR ALOFT WILL HANG
ON A BIT LONGER. FOR NOW...LOOKING FOR 2 TO 4 INCHES FROM ROCHESTER
EAST...INCLUDING THE NORTHERN FINGER LAKES REGIONS AND OSWEGO
COUNTY. THIS WILL BE A WET SNOW...POSSIBLY MIXED WITH SLEET AT
TIMES. QPFS SHOULD RANGE IN THE .25 TO .50 INCH RANGE THROUGH
DAYBREAK FRIDAY MORNING...LESS THAN THAN IN FAR NORTHERN SECTIONS.
THE COLDEST TEMPERATURES FOR TONIGHT SHOULD COME DURING THE EVENING
HOURS...MAINLY FROM EVAPORATIONAL COOLING AS PRECIPITATION STARTS.
TEMPERATURES SHOULD GRADUALLY RISE FOR MUCH OF THE NIGHT...WITH A
RAPID WARMING INTO THE 40S LIKELY TOWARD DAYBREAK IN THE SOUTHERN TIER AS
THE SURFACE LOW REACHES LAKE ERIE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE FORECAST SCENARIO FOR THE END OF THE WEEK AND THIS WEEKEND IS
COMING INTO SLIGHTLY BETTER FOCUS...HOWEVER DIFFERENCES IN THE TRACK
AND SPEED OF THE LARGE SURFACE LOW PROGGED TO IMPACT THE REGION
CONTINUE TO MAKE IT DIFFICULT TO NAIL DOWN THE DETAILS OF THE
FORECAST. WHAT IS CLEAR IS THAT A 500MB VORTMAX CURRENTLY OFF OF THE
PACIFIC NORTHWEST COAST WILL DIG ACROSS THE INTER-MOUNTAIN WEST INTO
THE GREAT PLAINS BEFORE EJECTING ACROSS THE GREAT LAKES...IN THE
PROCESS SPAWNING A SURFACE LOW THAT TAKES A SIMILAR TRACK. THE KEY
ISSUE IS HOW DEEP THE 500MB TROUGH DIGS INTO THE PLAINS...WHICH THEN
HAS AN IMPACT ON HOW FAR SOUTH THE SURFACE LOW FORMS...WHICH THEN
AFFECTS THE TRACK/STRENGTH OF SAID FEATURE. THE MODEL PROGS CONTINUE
TO FEATURE AN ENVELOPE OF TRACKS WITH THE NAM FEATURING THE
STRONGEST...FASTEST...MOST NORTHERLY TRACK FOR THE LOW AND THE ECMWF
THE SLOWEST...MOST SOUTHERLY...AND WEAKEST OF THE MODELS. THE GFS IS
TRENDING MORE TOWARDS THE NAM/SREF SOLUTION...TAKING A 987MB LOW
ACROSS LAKE ERIE AND THE NIAGARA PENINSULA LATE THURSDAY NIGHT AND
THE SAINT LAWRENCE VALLEY BY FRIDAY EVENING....WITH THE CMC
FEATURING A SLIGHTLY WEAKER LOW THAT TRACKS A LITTLE FARTHER
SOUTH...MORE ACROSS THE SOUTHERN TIER AND THE ADIRONDACKS. IN
ADDITION TO HAVING A SIGNIFICANT IMPACT ON THE STRENGTH OF THE WINDS
WE RECEIVE IN THE WAKE OF THE LOW...THE CMC SOLUTION WOULD ALSO KEEP
COLDER AIR OVER THE REGION FOR LONGER...RESULTING IN THE POTENTIAL
FOR MORE SIGNIFICANT SYNOPTIC SNOWFALL WITH THE LOW. THE CMC
SOLUTION IS ALSO PLAUSIBLE...AND CONSISTENT...WHICH ONLY FURTHER
PROPAGATES THE CONUNDRUM. FOR NOW WILL GO WITH A COMPROMISE BLEND OF
THE GFS AND CMC SOLUTIONS. GOING WITH THIS COMPROMISE SOLUTION...THE
SCENARIO FOR THE END OF THE WEEK AND THE WEEKEND UNFOLDS AS
FOLLOWS...
THE SURFACE LOW TRACKS TO A LOCATION APPROXIMATELY NEAR THE EASTERN
END OF LAKE ERIE THURSDAY NIGHT. ISENTROPIC UPGLIDE AHEAD OF THE LOW
WILL LEAD TO DEVELOPING PRECIPITATION FROM WEST TO EAST AND SOUTH TO
NORTH THROUGH THE NIGHT THURSDAY NIGHT. PRECIP TYPE WILL GENERALLY
BE A MIXTURE OF RAIN AND SNOW WITH ACCUMULATIONS LIMITED MAINLY TO
HIGHER TERRAIN OF THE SOUTHERN TIER AND ACROSS THE NORTH COUNTRY.
SOME AREAS IN THE NORTH COUNTRY/TUG HILL HAVE THE POTENTIAL TO SEE
AT LEAST 2 TO 4 INCHES OF WET SNOW THU NIGHT INTO FRIDAY
MORNING...WITH LOWER ACCUMULATIONS ACROSS HIGHEST ELEVATIONS OF THE
SOUTHERN TIER. EXPECT PRECIP TYPE TO CHANGE OVER TO ALL RAIN ACROSS
MUCH OF THE FORECAST AREA ON FRIDAY MORNING AS THE WARM SECTOR OF
THE LOW TRACKS ACROSS THE REGION. ONCE AGAIN...IF THE LOW TRACKS
FARTHER SOUTH...THIS COULD LIMIT THE NORTHWARD PROGRESSION OF THE
WARM AIR A LEAD TO GREATER COVERAGE/AMOUNT OF SNOWFALL THURSDAY
NIGHT INTO FRIDAY. FOR NOW...EXPECT LOWS IN THE LOW TO MID 30S...TO
UPPER 20S IN THE NORTH COUNTRY THU NIGHT WITH HIGHS IN THE UPPER 30S
TO AROUND 40 ON FRIDAY.
COLDER AIR FILTERS INTO THE REGION LATER IN THE DAY FRIDAY INTO
FRIDAY NIGHT. EXPECT PRECIP TO CHANGE BACK OVER TO SNOW BY THE END
OF THE DAY ON FRIDAY WITH A QUICK BURST OF SNOW POSSIBLE AS THE LOW
PULLS AWAY FROM THE AREA AND THE DEFORMATION BAND ONT HE BACK SIDE
OF THE LOW MOVES ACROSS THE REGION. BY LATER FRIDAY NIGHT 850MB
TEMPERATURES DROP BELOW -12C AND WITH FAIRLY UNIFORM WEST-NORTHWEST
FLOW ACROSS THE LAKES...WE SHOULD SEE A DECENT SETUP FOR LAKE EFFECT
SNOWS...PARTICULARLY ACROSS THE SOUTHEAST SNOWBELTS. SYNOPTIC
MOISTURE IS NOT LOOKING QUITE AS IMPRESSIVE AS IT HAS WITH PAST
RUNS...SO SNOWFALL ACCUMULATIONS MAY STAY SUB-ADVISORY. THE COLDER
AIR ADVECTING INTO THE REGION WILL ALSO ALLOW FOR TEMPERATURES TO
DROP BACK INTO SOMETHING APPROACHING NORMAL FOR THIS TIME OF YEAR
WITH LOWS IN THE 20S FRIDAY NIGHT AND HIGHS IN THE UPPER 20S TO LOW
30S SATURDAY.
HIGH PRESSURE OVER THE MIDWEST NUDGES EAST INTO THE EASTERN GREAT
LAKES FRIDAY NIGHT...WINDING DOWN THE LAKE EFFECT SNOWS AND BRINGING
AREAS OF CLEARING. EXPECT TEMPERATURES TO SEE A SIGNIFICANT DROP
WHERE THERE IS CLEARING...PARTICULARLY ACROSS THE NORTH COUNTRY
WHERE SUB-ZERO TEMPERATURES MAY BE POSSIBLE THANKS TO RADIATIONAL
COOLING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY WILL FEATURE A BREAK FROM THE ACTIVE WEATHER AS RIDGING MOVES
OVERHEAD. COLD AIR STILL IN PLACE WILL KEEP TEMPERATURES RIGHT
AROUND SEASONAL NORMS. THE RIDGING MOVES OFF TO THE EAST COAST
SUNDAY NIGHT WITH SOUTHERLY RETURN FLOW KICKING IN ACROSS THE REGION
RESULTING IN A RETURN TO MILD WEATHER FOR MONDAY WITH HIGHS CLIMBING
BACK INTO THE 40S. IN ADDITION TO THE MILD WEATHER...WE MAY SEE MORE
WET WEATHER AS A CUTTER LOW PLOWING ACROSS THE NORTHERN TIER OF THE
U.S. IS PROGGED TO CROSS THE GREAT LAKES INTO QUEBEC...POTENTIALLY
SWINGING A COLD FRONT ACROSS WESTERN NEW YORK LATE IN THE DAY MONDAY
AND BRINGING A CHANCE OF RAIN WITH A POTENTIAL FOR MORE LAKE EFFECT
SNOWS BEHIND THE FRONT ON TUESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A COLD FRONT STALLED ACROSS WESTERN NEW YORK ALONG THE SOUTHERN LAKE
SHORES SOUTHWEST INTO NORTHERN OH IS THE FOCUS FOR SOME LINGERING
SNOW EARLY THIS MORNING. TREND OF REGIONAL RADAR MOSAIC LOOP HAS
BACK EDGE OF SNOW MOVING ACROSS KBUF/KIAG/KJHW NEAR 06Z...FOR KROC
07Z AND KART BY 08-09Z. IFR OR LOWER CIGS MAY LINGER A BIT AFTER
THE SNOW ENDS...BUT WILL EVENTUALLY IMPROVE WITH TIME. WATER VAPOR
IMAGERY SHOWING SOME DRY AIR FILLING IN BEHIND THE BACK EDGE OF
SNOW AS UPPER SHORTWAVE PASSES EAST OF THE OH VALLEY.
DRIER AIR INFILTRATING BEHIND THE SNOW LATER THIS MORNING WILL BRING
VFR CONDITIONS BACK TO THE AREA AFTER 14Z...BUT ANOTHER SYSTEM WILL
ARRIVE FOR THURSDAY NIGHT. NAM/GFS/SREF MODELS ALL SHOW RAIN AND
LOWERING CIGS APPROACHING THE SOUTHERN TIER AND FAR WESTERN NY TOWARD
THE END OF THE TAF PERIOD.
OUTLOOK...
FRIDAY...MVFR WITH RAIN AND SNOW LIKELY.
SATURDAY...VFR...WITH IFR/MVFR IN SCATTERED SNOW SHOWERS AND AREAS
OF LAKE EFFECT SNOW EAST OF THE LAKES.
SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO.
&&
.MARINE...
EXPECT A DECENT EASTERLY FLOW TO DEVELOP AHEAD OF THE LOW LATE
TONIGHT...RESULTING IN A BRIEF PERIOD OF SMALL CRAFT CONDITIONS ON
WESTERN PORTIONS OF LAKE ONTARIO. AFTER THE LOW PASSES...SMALL CRAFT
ADVISORIES WILL LIKELY BE NEEDED ON LAKE ERIE IN A SOUTHWEST
FLOW...THOUGH THE EXACT TRACK OF THE LOW STILL IS A BIT UNCERTAIN.
THE LOW WILL MOVE INTO NEW ENGLAND ON FRIDAY NIGHT...BRINGING A
DECENT NORTHWESTER FLOW ACROSS ALL THE LAKE...WITH CONTINUED SMALL
CRAFT CONDITIONS A GOOD POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 11 AM EST FRIDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...APFFEL/SMITH
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
724 PM EST FRI FEB 24 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH ACROSS THE EASTERN CAROLINAS THIS
EVENING. SHOWERS AND ISOLATED THUNDERSTORMS WILL END AS THE FRONT
PASSES OVERHEAD. COOLER AND DRIER CONDITIONS WILL PREVAIL OVER THE
WEEKEND. A WARMING TREND IS EXPECTED THROUGH MUCH OF NEXT WEEK AS
HIGH PRESSURE MOVES OFFSHORE...AND STRONG LOW PRESSURE PASSES NORTH
OF THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 655 PM FRIDAY...TORNADO WATCH HAS BEEN CANCELLED AFTER
COLLABORATION WITH NWS RAH...MHX AND THE STORM PREDICTION CENTER.
SHOWERS AND EMBEDDED THUNDERSTORMS SHOULD NO LONGER HAVE THE
CAPABILITY OF PRODUCING SEVERE WEATHER. PREVIOUS DISCUSSION FROM
630 PM FOLLOWS...
FOR THE NEXT FEW HOURS...PREFRONTAL SQUALL LINE WILL PUSH EAST. AN
OBVIOUS MARINE LAYER IS EVIDENT IN LATEST MSAS ANALYSIS...AND THIS
SHOULD HELP SQUELCH CONVECTION AS IT HEADS TOWARDS THE COAST. STILL
SIGNIFICANT SBCAPE JUST INLAND FROM THE COAST WHICH WILL SUPPORT
STORMS FOR ANOTHER HOUR OR TWO...BUT LOW LEVEL LAPSE RATES...LI`S
AND INSTABILITY ALL DECREASE WITHIN 20 MILES OR SO OF THE COAST.
ADDITIONALLY...KLTX VWP SHOWS THAT LOW LEVEL WINDS HAVE DECREASED
SLIGHTLY TO AROUND 40 KTS AT 3 KFT. UNFORTUNATELY...HRRR HAS BEEN
DOWN...BUT LATEST RUC DIMINISHES THIS INITIAL BATCH BY 6PM WHICH
SEEMS PLAUSIBLE BASED OFF THE ONGOING ENVIRONMENT.
COLD FRONT WILL THEN APPROACH TONIGHT. THERE IS POTENTIAL FOR
RENEWED CONVECTION ALONG THE FRONT AS IT PUSHES THROUGH BETWEEN 6PM
AND 9PM. QUESTION BECOMES HOW MUCH RE-DESTABILIZATION CAN OCCUR
BEHIND THE ONGOING CONVECTION TO HELP FUEL STORMS ALONG THE FRONT.
NOTE THAT CAPE IS INCREASING ACROSS WESTERN PORTIONS OF NC AHEAD OF
THE FRONT...BUT DIURNAL HEATING WILL BE WORKING AGAINST US. WILL
KEEP CHANCE OF TSTMS THROUGH THE COLD FRONTAL PASSAGE...BUT THE
SEVERE THREAT WILL BE MINIMAL AFTER AROUND 6PM. OF COURSE...ANY
ELEVATED INSTABILITY THAT PERSISTS IN THE RESIDUAL LAYER COULD FORCE
STRONG UPDRAFTS SO WILL HAVE TO MONITOR RADAR TRENDS.
TEMPS WILL CRASH BEHIND THE FRONT TONIGHT AS GUSTY SW WINDS BECOME
GUSTY FROM THE NW. WINDS WILL CONTINUE TO GUST THROUGH MUCH OF THE
NIGHT TO 20 MPH OR SO...AND THIS WILL CAUSE TEMPS TO CRASH 20-25
DEGREES AFTER NIGHTFALL...WITH LOWS AROUND 40 INLAND...AND LOW 40S
AT THE COAST.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 330 PM FRIDAY...BY DAYBREAK SATURDAY A VASTLY DIFFERENT FEEL
TO THE AIR WITH COLD AIR ADVECTION UNDERWAY AND CLEARING SKY
TRENDS. MAX TEMPS 57-62 SATURDAY...AND GOOD RADIATIONAL COOLING
WILL ALLOW MINS SUNDAY MORNING TO DIP TO AROUND FREEZING IN MANY
INTERIOR LOCATIONS. SUNDAY A FEW IMPULSES OUT OF THE GULF WILL
BRING INCREASING CLOUDS AND A SLIGHT CHANCE OF LIGHT SHOWERS TO
OUR SOUTHERN ZONES SUNDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...EARLY AND MID WEEK MARKED BY RIDGING ALOFT
AND SOUTHERLY WIND FLOW. RIDGE BREAKS DOWN AS AN UPPER LOW PASSES
NORTH OF THE AREA AND BRINGS THE BEST CHANCE OF SHOWERS WEDNESDAY
INTO THURSDAY...WITH ZONAL FLOW IN WAKE OF THIS FEATURE.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...EXPECT LINGERING MVFR/IFR DUE TO RA/TSRA AT THE COASTAL
SITES OVER THE NEXT COUPLE OF HOURS...BECOMING VFR ACROSS THE ENTIRE
AREA BEFORE DAYBREAK. CURRENT RADAR IMAGERY DEPICTS A LINE OF
SHOWERS AND THUNDERSTORMS ALONG THE COAST...WITH SOME LINGERING
LIGHT SHOWERS ASSOCIATED WITH A STRONG COLD FRONT. EXPECT THIS FRONT
TO MOVE THROUGH THE TERMINALS THIS EVENING ALLOWING WINDS TO BECOME
WEST-NORTHWEST. CANNOT RULE OUT POSSIBLE GUSTS NEAR 25 KTS BEFORE
MIDNIGHT. AFTER MIDNIGHT...WINDS WILL SHIFT FROM WEST-NORTHWEST TO
MAINLY NORTHWEST THROUGHOUT SATURDAY MORNING...WITH WINDS AOB 10
KTS. CLOUDS WILL HAVE MOSTLY SCATTERED OUT BY DAYBREAK. AFTER
SUNRISE EXPECT VFR CONDITIONS TO PREVAIL. AFTER 14Z...NORTHWEST
WINDS WITH GUSTS NEAR 25 KTS WILL CONTINUE...WITH GUSTS SUBSIDING
AFTER SUNSET.
EXTENDED OUTLOOK...LOW CHANCE OF IFR/FOG EARLY MONDAY AND TUESDAY
WITH SHOWERS POSSIBLE LATER TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM FRIDAY...SQUALL LINE APPROACHING THE WATERS WILL CREATE
SOME SCATTERED THUNDERSTORMS AND A BRIEF INCREASE IN WINDS IN THE
NEXT FEW HOURS...BUT OTHERWISE FORECAST REMAINS ON TRACK. SOUTHWEST
WINDS OF 15-25 KTS WILL PERSIST THROUGH A COLD FRONTAL PASSAGE WHICH
WILL OCCUR TONIGHT AROUND MIDNIGHT. A RATHER SIGNIFICANT WIND SHIFT
OCCURS WITH THE COLD FRONT...FROM SW TO NW...AT STILL ELEVATED
SPEEDS OF 15-25 KTS. A FEW GALE FORCE GUSTS ARE POSSIBLE...BUT NOT
EXPECTED TO BE WIDESPREAD ENOUGH TO UPGRADE THE ONGOING SCA TO
ANYTHING HIGHER. SEAS HAVE BEEN SLIGHTLY BELOW PROGS...MOSTLY 4-6
FEET...BUT WILL CONTINUE TO BUILD TO 5-8 THROUGH TONIGHT...DOMINATED
BY A SW WIND CHOP. NW WINDS BEHIND THE FRONT WILL INITIALLY CREATE A
PERIOD OF HIGHLY CONFUSED SEAS...BEFORE NW WIND CHOP BECOMES THE
PREDOMINANT WAVE AND BEGINS TO DECREASE OVERNIGHT. SMALL CRAFT
ADVISORY WILL LIKELY BE ALLOWED TO EXPIRE ACROSS THE SOUTHERN WATERS
LATE TONIGHT...BUT PERSIST ACROSS AMZ250 AND AMZ252 THROUGH THE
MORNING.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ADVISORIES EXTENDED INTO MIDDAY SATURDAY OVER
OUR NORTHERN TWO MARINE ZONES DUE TO GUSTY NW WINDS. SEAS HOWEVER
WILL BE DAMPENING AND ONCE WINDS ABATE...ADVISORIES WILL BE DROPPED.
SUNDAY IMPROVED CONDITIONS AS WINDS TAPER OFF AS HIGH PRESSURE
PASSES JUST NORTH OF THE WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...ONSHORE
BUT LIGHT FLOW MON AND TUE WILL BECOME SOUTHERLY AND INCREASE LATE
TUESDAY THROUGH WEDNESDAY AHEAD OF A COLD FRONT EARLY THURSDAY...THUS
WE MAY BE LOOKING AT ADVISORY CONDITIONS MID WEEK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...JDW/8/TRA
SHORT TERM...MJC
LONG TERM...MJC
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
654 PM EST FRI FEB 24 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH ACROSS THE EASTERN CAROLINAS THIS
EVENING. SHOWERS AND ISOLATED THUNDERSTORMS WIL END AS THE FRONT
PASSES OVERHEAD. COOLER AND DRIER CONDITIONS WILL PREVAIL OVER THE
WEEKEND. A WARMING TREND IS EXPECTED THROUGH MUCH OF NEXT WEEK AS
HIGH PRESSURE MOVES OFFSHORE...AND STRONG LOW PRESSURE PASSES NORTH
OF THE REGION.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 655 PM FRIDAY...TORNADO WATCH HAS BEEN CANCELLED AFTER
COLLABORATION WITH NWS RAH...MHX AND THE STORM PREDICTION CENTER.
SHOWERS AND EMBEDDED THUNDERSTORMS SHOULD NO LONGER HAVE THE
CAPABILITY OF PRODUCING SEVERE WEATHER. PREVIOUS DISCUSSION FROM 630
PM FOLLOWS...
FOR THE NEXT FEW HOURS...PREFRONTAL SQUALL LINE WILL PUSH EAST. AN
OBVIOUS MARINE LAYER IS EVIDENT IN LATEST MSAS ANALYSIS...AND THIS
SHOULD HELP SQUELCH CONVECTION AS IT HEADS TOWARDS THE COAST. STILL
SIGNIFICANT SBCAPE JUST INLAND FROM THE COAST WHICH WILL SUPPORT
STORMS FOR ANOTHER HOUR OR TWO...BUT LOW LEVEL LAPSE RATES...LI`S
AND INSTABILITY ALL DECREASE WITHIN 20 MILES OR SO OF THE COAST.
ADDITIONALLY...KLTX VWP SHOWS THAT LOW LEVEL WINDS HAVE DECREASED
SLIGHTLY TO AROUND 40 KTS AT 3 KFT. UNFORTUNATELY...HRRR HAS BEEN
DOWN...BUT LATEST RUC DIMINISHES THIS INITIAL BATCH BY 6PM WHICH
SEEMS PLAUSIBLE BASED OFF THE ONGOING ENVIRONMENT.
COLD FRONT WILL THEN APPROACH TONIGHT. THERE IS POTENTIAL FOR
RENEWED CONVECTION ALONG THE FRONT AS IT PUSHES THROUGH BETWEEN 6PM
AND 9PM. QUESTION BECOMES HOW MUCH RE-DESTABILIZATION CAN OCCUR
BEHIND THE ONGOING CONVECTION TO HELP FUEL STORMS ALONG THE FRONT.
NOTE THAT CAPE IS INCREASING ACROSS WESTERN PORTIONS OF NC AHEAD OF
THE FRONT...BUT DIURNAL HEATING WILL BE WORKING AGAINST US. WILL
KEEP CHANCE OF TSTMS THROUGH THE COLD FRONTAL PASSAGE...BUT THE
SEVERE THREAT WILL BE MINIMAL AFTER AROUND 6PM. OF COURSE...ANY
ELEVATED INSTABILITY THAT PERSISTS IN THE RESIDUAL LAYER COULD FORCE
STRONG UPDRAFTS SO WILL HAVE TO MONITOR RADAR TRENDS.
TEMPS WILL CRASH BEHIND THE FRONT TONIGHT AS GUSTY SW WINDS BECOME
GUSTY FROM THE NW. WINDS WILL CONTINUE TO GUST THROUGH MUCH OF THE
NIGHT TO 20 MPH OR SO...AND THIS WILL CAUSE TEMPS TO CRASH 20-25
DEGREES AFTER NIGHTFALL...WITH LOWS AROUND 40 INLAND...AND LOW 40S
AT THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 330 PM FRIDAY...BY DAYBREAK SATURDAY A VASTLY DIFFERENT FEEL
TO THE AIR WITH COLD AIR ADVECTION UNDERWAY AND CLEARING SKY TRENDS.
MAX TEMPS 57-62 SATURDAY...AND GOOD RADIATIONAL COOLING WILL ALLOW
MINS SUNDAY MORNING TO DIP TO AROUND FREEZING IN MANY INTERIOR
LOCATIONS. SUNDAY A FEW IMPULSES OUT OF THE GULF WILL BRING
INCREASING CLOUDS AND A SLIGHT CHANCE OF LIGHT SHOWERS TO OUR
SOUTHERN ZONES SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...EARLY AND MID WEEK MARKED BY RIDGING ALOFT
AND SOUTHERLY WIND FLOW. RIDGE BREAKS DOWN AS AN UPPER LOW PASSES
NORTH OF THE AREA AND BRINGS THE BEST CHANCE OF SHOWERS WEDNESDAY
INTO THURSDAY...WITH ZONAL FLOW IN WAKE OF THIS FEATURE.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 20Z...A STRONG COLD FRONT WILL MOVE THROUGH THE TERMINALS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS ARE
CONTINUING TO DEVELOP WEST OF FLO...AND ARE EXPANDING MORE RAPIDLY
TO THE NORTHEAST THAN EAST. WILL INDICATE PRIMARILY MVFR
CONDITIONS AT FLO/LBT THROUGH MUCH OF THIS AFTERNOON WITH
THUNDERSTORMS/TEMPO IFR LIKELY AT LEAST THROUGH MID AFTERNOON.
MVFR CONDITIONS AT THE COASTAL TERMINALS CAN BE EXPECTED LATE
AFTERNOON WITH THE SAME THUNDERSTORM/TEMPO IFR POTENTIAL LATE
AFTERNOON/EARLY EVENING. AFTER FROPA EXPECT RAPID IMPROVEMENT TO
VFR MID-LEVEL CEILINGS WITH WINDS SHIFTING TO THE NORTHWEST. BY
MIDNIGHT SKIES SHOULD BECOME SCATTERED AT FLO/LBT AND AT THE
COASTAL TERMINALS IN THE PRE-DAWN HOURS. AFTER SUNRISE EXPECT VFR
CONDITIONS WITH SCATTERED CLOUDS AND NORTHWEST WINDS GUSTING TO 25
KNOTS.
EXTENDED OUTLOOK...LOW CHANCE OF IFR/FOG EARLY MONDAY AND TUESDAY
WITH SHOWERS POSSIBLE LATER TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM FRIDAY...SQUALL LINE APPROACHING THE WATERS WILL CREATE
SOME SCATTERED THUNDERSTORMS AND A BRIEF INCREASE IN WINDS IN THE
NEXT FEW HOURS...BUT OTHERWISE FORECAST REMAINS ON TRACK. SOUTHWEST
WINDS OF 15-25 KTS WILL PERSIST THROUGH A COLD FRONTAL PASSAGE WHICH
WILL OCCUR TONIGHT AROUND MIDNIGHT. A RATHER SIGNIFICANT WIND SHIFT
OCCURS WITH THE COLD FRONT...FROM SW TO NW...AT STILL ELEVATED
SPEEDS OF 15-25 KTS. A FEW GALE FORCE GUSTS ARE POSSIBLE...BUT NOT
EXPECTED TO BE WIDESPREAD ENOUGH TO UPGRADE THE ONGOING SCA TO
ANYTHING HIGHER. SEAS HAVE BEEN SLIGHTLY BELOW PROGS...MOSTLY 4-6
FEET...BUT WILL CONTINUE TO BUILD TO 5-8 THROUGH TONIGHT...DOMINATED
BY A SW WIND CHOP. NW WINDS BEHIND THE FRONT WILL INITIALLY CREATE A
PERIOD OF HIGHLY CONFUSED SEAS...BEFORE NW WIND CHOP BECOMES THE
PREDOMINANT WAVE AND BEGINS TO DECREASE OVERNIGHT. SMALL CRAFT
ADVISORY WILL LIKELY BE ALLOWED TO EXPIRE ACROSS THE SOUTHERN WATERS
LATE TONIGHT...BUT PERSIST ACROSS AMZ250 AND AMZ252 THROUGH THE
MORNING.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ADVISORIES EXTENDED INTO MIDDAY SATURDAY OVER
OUR NORTHERN TWO MARINE ZONES DUE TO GUSTY NW WINDS. SEAS HOWEVER
WILL BE DAMPENING AND ONCE WINDS ABATE...ADVISORIES WILL BE DROPPED.
SUNDAY IMPROVED CONDITIONS AS WINDS TAPER OFF AS HIGH PRESSURE
PASSES JUST NORTH OF THE WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...ONSHORE
BUT LIGHT FLOW MON AND TUE WILL BECOME SOUTHERLY AND INCREASE LATE
TUESDAY THROUGH WEDNESDAY AHEAD OF A COLD FRONT EARLY THURSDAY...THUS
WE MAY BE LOOKING AT ADVISORY CONDITIONS MID WEEK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR
AMZ254-256.
SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...JDW/8/TRA
SHORT TERM...MJC
LONG TERM...MJC
AVIATION...MRR/SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
629 PM EST FRI FEB 24 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH ACROSS THE FORECAST AREA THIS EVENING.
AHEAD OF THIS COLD FRONT SHOWERS AND ISOLATED STRONG THUNDERSTORMS
REMAIN POSSIBLE. COOLER AND DRIER CONDITIONS WILL PREVAIL OVER THE
WEEKEND. A WARMING TREND IS EXPECTED THROUGH MUCH OF NEXT WEEK AS
HIGH PRESSURE MOVES OFFSHORE...AND STRONG LOW PRESSURE PASSES NORTH
OF THE REGION.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 630 PM FRIDAY...TORNADO WATCH #38 CONTINUES ACROSS THE CWA
THROUGH 8PM TONIGHT.
FOR THE NEXT FEW HOURS...PREFRONTAL SQUALL LINE WILL PUSH EAST. AN
OBVIOUS MARINE LAYER IS EVIDENT IN LATEST MSAS ANALYSIS...AND THIS
SHOULD HELP SQUELCH CONVECTION AS IT HEADS TOWARDS THE COAST. STILL
SIGNIFICANT SBCAPE JUST INLAND FROM THE COAST WHICH WILL SUPPORT
STORMS FOR ANOTHER HOUR OR TWO...BUT LOW LEVEL LAPSE RATES...LI`S
AND INSTABILITY ALL DECREASE WITHIN 20 MILES OR SO OF THE COAST.
ADDITIONALLY...KLTX VWP SHOWS THAT LOW LEVEL WINDS HAVE DECREASED
SLIGHTLY TO AROUND 40 KTS AT 3 KFT. UNFORTUNATELY...HRRR HAS BEEN
DOWN...BUT LATEST RUC DIMINISHES THIS INITIAL BATCH BY 6PM WHICH
SEEMS PLAUSIBLE BASED OFF THE ONGOING ENVIRONMENT.
COLD FRONT WILL THEN APPROACH TONIGHT. THERE IS POTENTIAL FOR
RENEWED CONVECTION ALONG THE FRONT AS IT PUSHES THROUGH BETWEEN 6PM
AND 9PM. QUESTION BECOMES HOW MUCH RE-DESTABILIZATION CAN OCCUR
BEHIND THE ONGOING CONVECTION TO HELP FUEL STORMS ALONG THE FRONT.
NOTE THAT CAPE IS INCREASING ACROSS WESTERN PORTIONS OF NC AHEAD OF
THE FRONT...BUT DIURNAL HEATING WILL BE WORKING AGAINST US. WILL
KEEP CHANCE OF TSTMS THROUGH THE COLD FRONTAL PASSAGE...BUT THE
SEVERE THREAT WILL BE MINIMAL AFTER AROUND 6PM. OF COURSE...ANY
ELEVATED INSTABILITY THAT PERSISTS IN THE RESIDUAL LAYER COULD FORCE
STRONG UPDRAFTS SO WILL HAVE TO MONITOR RADAR TRENDS.
TEMPS WILL CRASH BEHIND THE FRONT TONIGHT AS GUSTY SW WINDS BECOME
GUSTY FROM THE NW. WINDS WILL CONTINUE TO GUST THROUGH MUCH OF THE
NIGHT TO 20 MPH OR SO...AND THIS WILL CAUSE TEMPS TO CRASH 20-25
DEGREES AFTER NIGHTFALL...WITH LOWS AROUND 40 INLAND...AND LOW 40S
AT THE COAST.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 330 PM FRIDAY...BY DAYBREAK SATURDAY A VASTLY DIFFERENT FEEL
TO THE AIR WITH COLD AIR ADVECTION UNDERWAY AND CLEARING SKY TRENDS.
MAX TEMPS 57-62 SATURDAY...AND GOOD RADIATIONAL COOLING WILL ALLOW
MINS SUNDAY MORNING TO DIP TO AROUND FREEZING IN MANY INTERIOR
LOCATIONS. SUNDAY A FEW IMPULSES OUT OF THE GULF WILL BRING
INCREASING CLOUDS AND A SLIGHT CHANCE OF LIGHT SHOWERS TO OUR
SOUTHERN ZONES SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...EARLY AND MID WEEK MARKED BY RIDGING ALOFT
AND SOUTHERLY WIND FLOW. RIDGE BREAKS DOWN AS AN UPPER LOW PASSES
NORTH OF THE AREA AND BRINGS THE BEST CHANCE OF SHOWERS WEDNESDAY
INTO THURSDAY...WITH ZONAL FLOW IN WAKE OF THIS FEATURE.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 20Z...A STRONG COLD FRONT WILL MOVE THROUGH THE TERMINALS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS ARE
CONTINUING TO DEVELOP WEST OF FLO...AND ARE EXPANDING MORE RAPIDLY
TO THE NORTHEAST THAN EAST. WILL INDICATE PRIMARILY MVFR
CONDITIONS AT FLO/LBT THROUGH MUCH OF THIS AFTERNOON WITH
THUNDERSTORMS/TEMPO IFR LIKELY AT LEAST THROUGH MID AFTERNOON.
MVFR CONDITIONS AT THE COASTAL TERMINALS CAN BE EXPECTED LATE
AFTERNOON WITH THE SAME THUNDERSTORM/TEMPO IFR POTENTIAL LATE
AFTERNOON/EARLY EVENING. AFTER FROPA EXPECT RAPID IMPROVEMENT TO
VFR MID-LEVEL CEILINGS WITH WINDS SHIFTING TO THE NORTHWEST. BY
MIDNIGHT SKIES SHOULD BECOME SCATTERED AT FLO/LBT AND AT THE
COASTAL TERMINALS IN THE PRE-DAWN HOURS. AFTER SUNRISE EXPECT VFR
CONDITIONS WITH SCATTERED CLOUDS AND NORTHWEST WINDS GUSTING TO 25
KNOTS.
EXTENDED OUTLOOK...LOW CHANCE OF IFR/FOG EARLY MONDAY AND TUESDAY
WITH SHOWERS POSSIBLE LATER TUESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM FRIDAY...SQUALL LINE APPROACHING THE WATERS WILL CREATE
SOME SCATTERED THUNDERSTORMS AND A BRIEF INCREASE IN WINDS IN THE
NEXT FEW HOURS...BUT OTHERWISE FORECAST REMAINS ON TRACK. SOUTHWEST
WINDS OF 15-25 KTS WILL PERSIST THROUGH A COLD FRONTAL PASSAGE WHICH
WILL OCCUR TONIGHT AROUND MIDNIGHT. A RATHER SIGNIFICANT WIND SHIFT
OCCURS WITH THE COLD FRONT...FROM SW TO NW...AT STILL ELEVATED
SPEEDS OF 15-25 KTS. A FEW GALE FORCE GUSTS ARE POSSIBLE...BUT NOT
EXPECTED TO BE WIDESPREAD ENOUGH TO UPGRADE THE ONGOING SCA TO
ANYTHING HIGHER. SEAS HAVE BEEN SLIGHTLY BELOW PROGS...MOSTLY 4-6
FEET...BUT WILL CONTINUE TO BUILD TO 5-8 THROUGH TONIGHT...DOMINATED
BY A SW WIND CHOP. NW WINDS BEHIND THE FRONT WILL INITIALLY CREATE A
PERIOD OF HIGHLY CONFUSED SEAS...BEFORE NW WIND CHOP BECOMES THE
PREDOMINANT WAVE AND BEGINS TO DECREASE OVERNIGHT. SMALL CRAFT
ADVISORY WILL LIKELY BE ALLOWED TO EXPIRE ACROSS THE SOUTHERN WATERS
LATE TONIGHT...BUT PERSIST ACROSS AMZ250 AND AMZ252 THROUGH THE
MORNING.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ADVISORIES EXTENDED INTO MIDDAY SATURDAY OVER
OUR NORTHERN TWO MARINE ZONES DUE TO GUSTY NW WINDS. SEAS HOWEVER
WILL BE DAMPENING AND ONCE WINDS ABATE...ADVISORIES WILL BE DROPPED.
SUNDAY IMPROVED CONDITIONS AS WINDS TAPER OFF AS HIGH PRESSURE
PASSES JUST NORTH OF THE WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 3 PM FRIDAY...ONSHORE
BUT LIGHT FLOW MON AND TUE WILL BECOME SOUTHERLY AND INCREASE LATE
TUESDAY THROUGH WEDNESDAY AHEAD OF A COLD FRONT EARLY THURSDAY...THUS
WE MAY BE LOOKING AT ADVISORY CONDITIONS MID WEEK.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR
AMZ254-256.
SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...JDW/8
SHORT TERM...MJC
LONG TERM...MJC
AVIATION...MRR/SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
615 PM EST FRI FEB 24 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION THROUGH EARLY EVENING.
COOLER AND DRIER CONDITIONS ARE EXPECTED BEHIND THE COLD FRONT LATE
TONIGHT THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 310 PM FRIDAY...
THROUGH THIS EVENING: THE SURFACE COLD FRONT ACCORDING TO THE LATEST
MESOANALYSIS HAS PUSHED WELL INTO THE NC MOUNTAINS. STRONG TO SEVERE
CONVECTION CONTINUES TO STREAK ACROSS SOUTHEAST NC... SUPPORTED IN
LARGE PART BY A LOW LEVEL JET STREAK AND ASSOCIATED MASS
CONVERGENCE. WITH EARLY-DAY SURFACE HEATING COMBINED WITH WEAK MID
LEVEL COOLING... THE COLUMN CONTINUES TO DESTABILIZE WITH SURFACE
CAPE ESTIMATED TO BE AROUND 400-1000 J/KG ACROSS THE AREA (AND
MEASURED AT AROUND 400 J/KG ON THE SPECIAL 18Z GSO SOUNDING)...
ALTHOUGH THE BLOWOFF FROM THESE SOUTHEAST STORMS AND FROM EARLIER
SC/GA CONVECTION HAS SPREAD ACROSS EAST-CENTRAL NC AND TEMPERED THE
INSTABILITY A BIT HERE... DESPITE SURFACE DEW POINTS WELL INTO THE
60S. THE INTENSE WIND FIELD (0-6 KM SHEAR NEAR 70 KTS AND 0-1 KM
SHEAR OF AROUND 40 KTS) WILL REMAIN SUPPORTIVE OF ORGANIZED SEVERE
CONVECTION... AND WE HAVE INDEED SEEN THESE DISCRETE CELLS AND
BOWING SEGMENTS BECOME MORE ORGANIZED OVER THE WESTERN PIEDMONT...
JUST A BIT AHEAD OF THE FRONT... IN THE LAST HOUR. FURTHER
DEVELOPMENT INTO A MATURE QLCS SHOULD BRING A WIDESPREAD THREAT OF
DAMAGING WINDS FOR THE REST OF THE AFTERNOON INTO EARLY EVENING.
ISOLATED TORNADOES REMAIN POSSIBLE GIVEN THE NICELY CURVED HODOGRAPH
THROUGH THE LOWEST 3 KM NOTED ON RUC PROXIMITY SOUNDINGS... AND DEEP
MOISTURE (BLENDED TPW IMAGERY SHOWING VALUES AROUND 200% OF NORMAL)
WITH HIGH DEW POINTS SHOULD ENSURE SUFFICIENTLY LOW LCL HEIGHTS FOR
A POSSIBLE STRONG TORNADO OR TWO. A TORNADO WATCH REMAINS IN EFFECT
UNTIL 8 PM FOR ALL OF CENTRAL NC. EXPECT THE SURFACE FRONT AND
PRECEDING STORMS TO SWEEP EAST OF THE FORECAST AREA BY MID
EVENING... FOLLOWED BY FAIR SKIES AND FALLING TEMPS OVERNIGHT. LOWS
34-42 WITH THE LOWER TROPOSPHERE REMAINING WINDY AND WELL-MIXED
OVERNIGHT WITH COLD AIR ADVECTION.
FOR SATURDAY/SATURDAY NIGHT: THE MID LEVEL LOW TRACKING OVER LAKES
ERIE/ONTARIO AND UP THE ST LAWRENCE VALLEY OVERNIGHT WILL MOVE TO
THE CANADIAN MARITIMES SATURDAY... AS THE MID LEVEL TROUGH AXIS
SHIFTS OVER NC. THE MSLP GRADIENT REMAINS QUITE TIGHT SUCH THAT
WINDS WILL INCREASE ANEW AFTER SUNRISE TO SUSTAINED 17-23 MPH WITH
GUSTS TO AROUND 30-35 MPH... LASTING THROUGH EARLY AFTERNOON BEFORE
SLOWLY DIMINISHING AS THE LARGE SURFACE HIGH BUILDS IN FROM THE
WEST. THESE WINDS COMBINED WITH LOW RELATIVE HUMIDITY VALUES WILL
BRING ABOUT A RISK OF ADVERSE FIRE WEATHER CONDITIONS (SEE
DISCUSSION BELOW). STRONG LOW LEVEL COLD AIR ADVECTION AND UPSTREAM
TEMPS TODAY POINT TO HIGHS OF 52-58 SATURDAY... UNDER MOSTLY SUNNY
SKIES. CLEAR SATURDAY NIGHT WITH CHILLY LOWS OF 25-30 AS WINDS
DIMINISH TO NEARLY CALM DURING THE NIGHT. -GIH
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 120 PM FRIDAY...
THE SOUTHERN STREAM WAVE OVER MEXICO WILL LIFT NORTHEASTWARD AND
DEAMPLIFY ACROSS THE CAROLINAS ON SUNDAY. SINCE STABLE SURFACE HIGH
PRESSURE (~1030-1035 MB) WILL PREVAIL DURING THAT TIME...EXPECT ONLY
CONSIDERABLE HIGH CLOUDINESS IN ASSOCIATION WITH THE WAVE ALOFT.
HIGH TEMPERATURES...ADJUSTED DOWN SEVERAL DEGREES FROM THE PREVIOUS
FORECAST...ARE EXPECTED TO RISE TO WITHIN A DEGREE OR TWO OF 50
DEGREES. HIGH PRESSURE WILL THEN DRIFT OFFSHORE BUT CONTINUE TO
EXTEND WESTWARD ACROSS NC AND MAINTAIN FAIR WEATHER THROUGH EARLY
NEXT WEEK. GOOD RADIATIONAL COOLING WITH PROJECTED LOW LEVEL
THICKNESSES AROUND 1320 METERS SUGGESTS LOWS IN THE UPPER 20S TO
LOWER 30S...WHILE DEVELOPING RETURN FLOW BY LATE MON SHOULD ALLOW
TEMPERATURES TO CLIMB INTO THE LOWER TO MIDDLE 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...
MON NIGHT-TUE NIGHT: A LOW LEVEL WARM ADVECTION REGIME WILL SUPPORT
INCREASING MOISTURE IN THE LOWEST 10 THOUSAND FT LATE MON NIGHT AND
ESPECIALLY TUE...WHICH WILL PROVIDE FOR INCREASING CLOUDINESS...AND
A CHANCE OF SHOWERS MAINLY OVER THE SOUTHERN AND WESTERN PORTIONS OF
THE CWFA TUE...AND AREA-WIDE WITH A WARM FRONTAL PASSAGE TUE NIGHT.
TEMPERATURES WILL ACCORDINGLY FURTHER MODERATE - MIDDLE 30S TO
AROUND 40 DEGREES MON NIGHT...MIDDLE 60S TUE...AND MOSTLY PRIOR TO
MIDNIGHT LOWS IN THE MIDDLE 40S TO LOWER 50S (COOLEST NE) COURTESY
OF THE PASSING WARM FRONT.
WED-FRI: A PAIR OF UPPER TROUGHS...IN A PROGRESSIVE UPPER FLOW
PATTERN ACROSS THE CONUS...WILL SUPPORT A COUPLE OF MIGRATORY
SURFACE CYCLONES TO OUR NW (MUCH LIKE THE MAJORITY OF THIS WINTER
WEATHER SEASON) OWING TO A PERSISTENT 588 DM SUB-TROPICAL RIDGE OVER
THE CARIBBEAN. GUIDANCE SUGGESTS THE FRONT TRAILING THE FIRST
CYCLONE WILL CROSS THE MIDDLE ATLANTIC REGION WITH A GOOD CHANCE OF
SHOWERS (AND PERHAPS A FEW STORMS DUE TO THE PRECEDING WARMTH IN THE
70S) WED INTO WED NIGHT. CLEARING AND TURNING COOLER...BUT STILL
ABOVE AVERAGE...FOR THU-THU NIGHT...BEFORE THE THE SECOND FRONTAL
SYSTEM BRINGS ANOTHER THREAT OF SHOWERS BY THE END OF THE WORK WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 615 PM FRIDAY...
THE LINE OF STORMS OVER THE COASTAL PLAIN OF NC... NOW MUCH WEAKENED
FROM THEIR EARLIER STATE... AND THEIR ASSOCIATED BRIEF MVFR TO IFR
CONDITIONS WILL EXIT THE RWI AND FAY TAF AREAS BEFORE 02Z. AS A COLD
FRONT CONTINUES MOVING EASTWARD THROUGH EASTERN NC... STRONG GUSTY
SW WINDS HAVE SHIFTED TO W AND WNW (FROM 270 THROUGH 310 DEGREES)
SUSTAINED AT 15-20 KTS GUSTING TO 25-35 KTS. THIS STRONG WIND SHEAR
IN THE LOWEST FEW THOUSAND FEET MAY INDUCE MECHANICAL TURBULENCE
THAT COULD BE HAZARDOUS ESPECIALLY TO SMALL AIRCRAFT OVER THE NEXT
FEW HOURS... AND THE COMPONENT FROM THE NW WILL BE A NOTABLE
CROSSWIND AT GSO/RDU/RWI/FAY. THESE WINDS WILL DECREASE FROM 02Z
ONWARD BUT STILL EXPECT SUSTAINED WINDS OF 10-15 KTS GUSTING TO NEAR
20 KTS OVERNIGHT. REMAINING CLOUDS WILL CLEAR OUT PRIOR TO 05Z...
AND VFR CONDITIONS ARE LIKELY FROM MIDNIGHT TONIGHT THROUGH
SATURDAY. MAINLY WESTERLY WINDS WILL PICK BACK UP SATURDAY MORNING
AT 15-20 KTS SUSTAINED AND GUSTING TO 25-30 KTS... BEFORE
DIMINISHING ONCE AGAIN BY 21Z SATURDAY AFTERNOON AS HIGH PRESSURE
BUILDS IN FROM THE WEST.
LOOKING BEYOND EARLY SATURDAY EVENING: VFR CONDITIONS WILL PREVAIL
INTO MONDAY NIGHT. MVFR/IFR FOG/STRATUS IS POSSIBLE TUESDAY MORNING
INTO WEDNESDAY IN ASSOCIATION WITH AN APPROACHING FRONTAL SYSTEM.
STRENGTHENING WINDS FROM THE SW ARE ALSO POSSIBLE WEDNESDAY. -GIH
&&
.FIRE WEATHER...
AS OF 140 PM FRIDAY...
...RED FLAG WATCH FOR SATURDAY AFTERNOON FOR NORTHWEST PIEDMONT...
STRONG GUSTY SOUTHWEST WINDS OF 35 TO 40 MPH AHEAD OF A COLD FRONT
WILL SHIFT TO WEST NORTHWEST LATE THIS AFTERNOON AND EVENING IN THE
WAKE OF THE EXITING FRONT. TEMPERATURES OUTSIDE SHOWERS ARE IN THE
MID TO UPPER 70S THIS AFTERNOON. LOWEST RELATIVE HUMIDITIES WILL BE
MODEST... FALLING NO LOWER THAN 35 PERCENT THIS EVENING BEFORE
RISING OVERNIGHT. RAINFALL WILL BE SPOTTY IN THE WEST... WITH
WIDESPREAD RAINS IN THE EAST OF AS MUCH AS ONE INCH. SCATTERED
THUNDERSTORMS ARE FORECAST... MAINLY EAST.
BREEZY WEST NORTHWEST WINDS 15 TO 20 MPH WITH GUSTS OF 30 TO 35 MPH
ARE EXPECTED BY MID MORNING SATURDAY... CONTINUING INTO THE
AFTERNOON. MINIMUM RELATIVE HUMIDITIES WILL FALL TO 15 TO 25
PERCENT. HOWEVER IT WILL BE MUCH COOLER WITH HIGHS IN THE 50S.
A RED FLAG WATCH WILL BE ISSUED FOR MUCH OF WESTERN NORTH CAROLINA
WEST OF HIGHWAY 220. ANY POSSIBLE RED FLAG WATCH WILL BE ADJUSTED
SATURDAY MORNING BASED ON RAINFALL FALLING THIS AFTERNOON.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY EVENING
FOR NCZ007-021>023-038-039-073.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...HARTFIELD
FIRE WEATHER...99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
622 AM EST THU FEB 23 2012
.SYNOPSIS...
WARM TEMPERATURES WILL PREVAIL OVER THE NEXT FEW DAYS AHEAD OF AN
APPROACHING COLD FRONT. SHOWERS AND A FEW STRONG THUNDERSTORMS ARE
POSSIBLE FRIDAY AS THE COLD FRONT PUSHES ACROSS THE REGION. DRY
AND COOLER AIR WILL OVERSPREAD THE EASTERN CAROLINAS THIS WEEKEND.
TEMPERATURES WILL REBOUND EARLY NEXT WEEK AS HIGH PRESSURE MOVES
OFFSHORE AND ALLOWS MILD SOUTHERLY WINDS TO SPREAD ACROSS THE
AREA.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 400 AM THURSDAY...CONVECTION HAVING APPROACHED FROM THE WEST
HAS DWINDLED AWAY EARLY THIS MORNING...WITH HRRR HAVING INDICATED
THAT THIS WOULD TAKE PLACE. LOW LEVEL MOISTURE AND A SCREAMING LOW
LEVEL JET 50+ KT AT 925 MB...WILL RESULT IN SCT/BKN LOW STRATUS
EARLY THIS MORNING. BY MID MORNING THE STRATUS DECK WILL DISSIPATE
AS THE JET DIMINISHES AND WITH THE DAYS INSOLATION HAVING COMMENCED.
A WEAK MID LEVEL S/W TROF ACCOMPANIED WITH CONVECTION AND MOVING
ACROSS THE APPALACHIAN MOUNTAINS...SHOULD EITHER PASS JUST NORTH OF
THE ILM CWA OR DISSIPATE AS IT TRACKS DOWN THE LEEWARD SIDE OF THE
MOUNTAINS. AS A RESULT HAVE KEPT POPS OUT OF THE FORECAST TODAY INTO
THIS EVENING. MODELS IN GOOD AGREEMENT WITH A SFC LOW AND ITS POTENT
UPPER S/W TROF EMERGING FROM THE ROCKY MOUNTAINS TODAY...THEN RACING
TO THE OHIO RIVER VALLEY BY EARLY THIS EVENING...AND REACHING LAKE
ERIE BY DAYBREAK FRIDAY. THE ASSOCIATED STRONG COLD FRONT....WILL BE
ON THE DOORSTEPS OF THE ILM CWA COME FRIDAY MORNING...IN ACTUALITY
LYING ACROSS THE CENTRAL CAROLINAS. AHEAD OF THE FRONT...EXCELLENT
WARM AIR ADVECTION TO OCCUR ACROSS THE FA AS EVIDENCED BY MODELS
INCREASING 8H TEMPS TO 14 TO 17 DEGREES CELSIUS BY EARLY FRIDAY
MORNING...WITH 1K-8H PARTIAL THICKNESSES REACHING 1392 TONIGHT. AND
THEY CALL THIS FEBRUARY? WITH THIS SAID...HAVE TWEAKED TODAYS MAX
TEMPS UPWARD BY A DEGREE OR 3...WITH A FEW LOCATIONS BREAKING THE 80
DEGREE MARK. WINDS WILL BE WSW IN THE MORNING...BACKING TO SW OR SSW
THIS AFTERNOON ALONG THE COAST WHICH WILL LIMIT MAX TEMPS TO THE
70-75 DEGREE RANGE BEFORE FALLING BACK INTO THE 60S THIS AFTERNOON
DUE TO ADJACENT SSTS IN THE 50S. A MILD EARLY MAY NITE PROGGED FOR
TONIGHT...HOWEVER THE CALENDER STATES ITS STILL FEBRUARY. LOOK FOR
LOWS IN THE 60S WITH SOME 50S ALONG THE IMMEDIATE COAST. POPS WILL
BEGIN TO RAMP UP TOWARDS DAYBREAK AS THE SFC COLD FRONT APPROACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MODELS HAVE TURNED MUCH DRIER WITH FRIDAY`S
DYNAMIC FROPA. WHILE GIVEN THE STRENGTH OF THE LOW LEVEL FORCING IT
SEEMS HARD TO GO AS DRY AS SAY THE WRF...WITH 00 RAINFALL IT DOES
APPEAR THAT FOR THE MOST PART RAINFALL AMOUNTS WILL DISAPPOINT
(GIVEN THE DROUGHT). LIKELY POPS WILL BE MAINTAINED SINCE ALTHOUGH
SIGNIFICANT RAINFALL MAY BE HARD TO COME BY MEASURABLE RAINFALL
SHOULD NOT. LOW LEVEL WIND FIELDS NOT AS STRONG AS PREV GUIDANCE SO
SEVERE THREAT SEEMS LESSENED BUT STILL CERTAINLY NON-ZERO. `SEVERE
SHOWERS` A LIKELY THREAT DUE TO LOW LEVEL WIND SPEED/STORM
MOTION/LACK OF INSTABILITY. STRONG CAA FRIDAY NIGHT INTO SATURDAY TO
BRING SLIGHTLY BELOW CLIMO TEMPS FOR THE REST OF THE PERIOD WHILE
SKY CLEARS OUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLOW IN PLACE AT THE START OF THE
PERIOD WITH ZONAL MID LEVEL FLOW QUICKLY SPREADING ACROSS THE
SOUTHEAST. LARGE AREA OF SURFACE HIGH PRESSURE WILL ALSO BE NEARING
THE COAST MAKING SUNDAY ONE LAST DAY OF NEAR TO SLIGHTLY BLOW CLIMO
TEMPS. THIS HIGH WILL END UP OFFSHORE BY MONDAY LEADING TO MILDER
WEATHER AND THE RETURN FLOW OF SOME MOISTURE. THIS MAY EITHER SIMPLY
TAKE THE FORM OF SOME CLOUDINESS OR SOME LOW RAIN CHANCES SHOULD A
COASTAL TROUGH DEVELOP AS INDICATED BY SOME MODELS. HIGH PRESSURE
WILL SIMILARLY BE FOUND WELL OFF THE COAST ON TUESDAY WHILE A COLD
FRONT LIES ALIGNED WITH THE ZONAL FLOW SOMEWHERE NEAR THE
MASON-DIXON LINE. WHILE RAIN CHANCES REMAIN TOUGH TO RULE OUT THERE
STILL REALLY ISNT MUCH FOR A TRIGGERING MECHANISM ESPECIALLY GIVEN
THE BROAD UPPER HIGH OVER THE GOMEX/CARIBBEAN. UPPER FLOW WILL TILT
TO MORE SW ON WED AS STORM SYSTEM DEVELOPS OVER TN/MS VALLEY AREAS
POSSIBLY LEADING TO A SLIGHT INC IN POPS LOCALLY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...LOW CONFIDENCE EARLY DUE TO FOG/STRATUS...BECOMING HIGH
CONFIDENCE IN VFR BY THIS AFTN. MORE STRATUS IS POSSIBLE LATE IN
THIS VALID PERIOD.
A LINE OF SHOWERS ASSOCIATED WITH AN UPPER IMPULSE HAS MOVED AWAY
FROM THE AREA...BUT SOME LOW STRATUS CONTINUING ESPECIALLY NEAR THE
COAST. EXPECT THIS TO SCATTER OUT BY THE VALID TIME...BUT MAY STILL
CREATE SOME SHORT DURATION MVFR CIGS FOR A FEW HOURS THIS MORNING.
BIGGER CONCERN IS AT LBT WHERE VLIFR FOG AND IFR CIGS WILL CONTINUE
FOR AN HOUR OR TWO BEFORE LIFTING. AM A LITTLE SURPRISED TO SEE IFR
VSBYS AT LBT...BUT NOTE A SLIGHT DECREASE IN PG WHICH HAS ALLOWED
WINDS TO GO CALM. AS GRADIENT TIGHTENS THIS MORNING...AND MIXING
TAPS MUCH STRONGER WINDS ALOFT...ANY IFR WILL ERODE NO LATER THAN
9AM. THEREAFTER...VFR EXPECTED AT ALL TERMINALS WITH SW WINDS
GUSTING 20-25 KTS THROUGH THE DAY. LATEST NAM PROFILES SUGGEST THAT
MVFR CIGS WILL REDEVELOP THIS AFTN IN THE FORM OF A CU DECK...BUT
THIS IS LIKELY OVERDONE DUE TO DRY AIR IN THE MID LEVELS.
WINDS REMAIN ELEVATED AFTER SUNSET EVEN AS GUSTS DECREASE. ALL
GUIDANCE SUGGESTING WIDESPREAD IFR VSBYS AND STRATUS TONIGHT.
HOWEVER...AM NOT CONFIDENT IN THIS OCCURRING. FOR ONE...WINDS SHOULD
BE TOO STRONG TO SUPPORT IFR FOG...AND TWO...DEEP UNIDIRECTIONAL SW
FLOW IS NOT IDEAL FOR LOW STRATUS DEVELOPMENT. STILL...A VERY MOIST
AIRMASS IN PLACE COULD SUPPORT STRATUS SO HAVE MENTIONED SCT AT IFR
LEVEL FOR NOW AND WILL UPDATE WITH LATER ISSUANCES.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHOWERS FRIDAY AFTN AND
EVE WITH AT LEAST MVFR. VFR SAT THROUGH MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM THURSDAY...SCA CONDITIONS FOR ALL WATERS BY
DAYBREAK...AND CONTINUING THROUGH DAYBREAK SATURDAY. WAA OVER THE
COOLER SHELF WATERS WILL BE A DETERRENT FOR THE STRONGER WINDS ALOFT
FROM MIXING DOWN. HOWEVER...A TIGHTENED SFC PG THROUGHOUT THE NEAR
TERM...WILL PRODUCE SW WINDS IN THE 15 TO 25 KT RANGE...WITH A FEW
GUSTS TO 30 KT ACROSS THE OUTER WATERS OFF CAPE FEAR WHERE SSTS ARE
IN THE 60S IN TURN ALLOWING WINDS ALOFT TO MIX TO THE OCEAN SFC.
SEAS WILL RANGE BETWEEN 3 AND 6 FT...EXCEPT FOR THE WATERS BETWEEN
CAPE FEAR TO MURRELLS INLET...WHERE SEAS WILL BE HIGHER BY 2 TO 3
FT...IE. 5 TO 9 FT...DUE TO AN INCREASED FETCH AND A FAVORABLE WIND
DIRECTION. THE DECAYING ESE 10-12 SECOND PERIOD SWELL OF THE PAST
SEVERAL DAYS HAS GIVEN UP TO THE LOCALLY PRODUCED SHORT PERIOD WIND
DRIVEN WAVES EXHIBITING 5 TO 8 SECOND PERIODS. THE ENERGY FROM THESE
WAVES BY FAR ENCOMPASS THE SIGNIFICANT SEAS THRUOUT THE NEAR TERM AS
WITNESSED WITH THE LATEST AND PROGGED SPECTRAL DENSITY CHARTS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...DYNAMIC COLD FRONT TO KEEP A SOLID SMALL CRAFT
ADVISORY IN EFFECT ON FRIDAY. FRIDAY EVENING FROPA TO YIELD A SHARP
VEER AND A CONTINUATION OF SCA WINDS IN THE COLD SURGE EVEN AS THE
OFFSHORE COMPONENT OF THE WINDS STARTS TO KNOCK DOWN THE OVERALL
HEIGHT OF THE SEAS FIRST ALONG SHORE. BY SATURDAY THINGS WILL HAVE
SETTLED TO WHERE A SCEC WILL BE NEEDED AND CONTINUED IMPROVEMENT IN
CONDITIONS SLATED FOR THE AFTERNOON AND EVENING HOURS ALBEIT
SOMEWHAT GRADUAL IN NATURE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...SUNDAY BRINGS PROGRESSIVE AREA OF HIGH
PRESSURE THAT WILL GO FROM BEING OVER THE LANDMASS IN THE MORNING TO
OFF THE COAST BY EVENING. MODERATE NE WINDS TO START WILL VEER AND
LIGHTEN AS THE DAY WEARS ON WITH A CORRESPONDING ABATEMENT OF WAVE
HEIGHT. ADDITIONAL VEERING IS IN STORE FOR MONDAY BUT THE DEGREE OF
WIND CHANGE IS UNCERTAIN PENDING WHETHER OR NOT A COASTAL TROUGH
MANAGES TO DEVELOP. EVEN SO THERE WILL BE A PREDOMINANTLY ONSHORE
FLOW AND SEAS LIKELY IN THE 2 TO 3 FT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 7 AM EST
SATURDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...XVII
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
415 AM EST THU FEB 23 2012
.SYNOPSIS...
WARM TEMPERATURES WILL PREVAIL OVER THE NEXT FEW DAYS AHEAD OF AN
APPROACHING COLD FRONT. SHOWERS AND A FEW STRONG THUNDERSTORMS ARE
POSSIBLE FRIDAY AS THE COLD FRONT PUSHES ACROSS THE REGION. DRY
AND COOLER AIR WILL OVERSPREAD THE EASTERN CAROLINAS THIS WEEKEND.
TEMPERATURES WILL REBOUND EARLY NEXT WEEK AS HIGH PRESSURE MOVES
OFFSHORE AND ALLOWS MILD SOUTHERLY WINDS TO SPREAD ACROSS THE
AREA.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 400 AM THURSDAY...CONVECTION HAVING APPROACHED FROM THE WEST
HAS DWINDLED AWAY EARLY THIS MORNING...WITH HRRR HAVING INDICATED
THAT THIS WOULD TAKE PLACE. LOW LEVEL MOISTURE AND A SCREAMING LOW
LEVEL JET 50+ KT AT 925 MB...WILL RESULT IN SCT/BKN LOW STRATUS
EARLY THIS MORNING. BY MID MORNING THE STRATUS DECK WILL DISSIPATE
AS THE JET DIMINISHES AND WITH THE DAYS INSOLATION HAVING COMMENCED.
A WEAK MID LEVEL S/W TROF ACCOMPANIED WITH CONVECTION AND MOVING
ACROSS THE APPALACHIAN MOUNTAINS...SHOULD EITHER PASS JUST NORTH OF
THE ILM CWA OR DISSIPATE AS IT TRACKS DOWN THE LEEWARD SIDE OF THE
MOUNTAINS. AS A RESULT HAVE KEPT POPS OUT OF THE FORECAST TODAY INTO
THIS EVENING. MODELS IN GOOD AGREEMENT WITH A SFC LOW AND ITS POTENT
UPPER S/W TROF EMERGING FROM THE ROCKY MOUNTAINS TODAY...THEN RACING
TO THE OHIO RIVER VALLEY BY EARLY THIS EVENING...AND REACHING LAKE
ERIE BY DAYBREAK FRIDAY. THE ASSOCIATED STRONG COLD FRONT....WILL BE
ON THE DOORSTEPS OF THE ILM CWA COME FRIDAY MORNING...IN ACTUALITY
LYING ACROSS THE CENTRAL CAROLINAS. AHEAD OF THE FRONT...EXCELLENT
WARM AIR ADVECTION TO OCCUR ACROSS THE FA AS EVIDENCED BY MODELS
INCREASING 8H TEMPS TO 14 TO 17 DEGREES CELSIUS BY EARLY FRIDAY
MORNING...WITH 1K-8H PARTIAL THICKNESSES REACHING 1392 TONIGHT. AND
THEY CALL THIS FEBRUARY? WITH THIS SAID...HAVE TWEAKED TODAYS MAX
TEMPS UPWARD BY A DEGREE OR 3...WITH A FEW LOCATIONS BREAKING THE 80
DEGREE MARK. WINDS WILL BE WSW IN THE MORNING...BACKING TO SW OR SSW
THIS AFTERNOON ALONG THE COAST WHICH WILL LIMIT MAX TEMPS TO THE
70-75 DEGREE RANGE BEFORE FALLING BACK INTO THE 60S THIS AFTERNOON
DUE TO ADJACENT SSTS IN THE 50S. A MILD EARLY MAY NITE PROGGED FOR
TONIGHT...HOWEVER THE CALENDER STATES ITS STILL FEBRUARY. LOOK FOR
LOWS IN THE 60S WITH SOME 50S ALONG THE IMMEDIATE COAST. POPS WILL
BEGIN TO RAMP UP TOWARDS DAYBREAK AS THE SFC COLD FRONT APPROACHES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...MODELS HAVE TURNED MUCH DRIER WITH FRIDAY`S
DYNAMIC FROPA. WHILE GIVEN THE STRENGTH OF THE LOW LEVEL FORCING IT
SEEMS HARD TO GO AS DRY AS SAY THE WRF...WITH 00 RAINFALL IT DOES
APPEAR THAT FOR THE MOST PART RAINFALL AMOUNTS WILL DISAPPOINT
(GIVEN THE DROUGHT). LIKELY POPS WILL BE MAINTAINED SINCE ALTHOUGH
SIGNIFICANT RAINFALL MAY BE HARD TO COME BY MEASURABLE RAINFALL
SHOULD NOT. LOW LEVEL WIND FIELDS NOT AS STRONG AS PREV GUIDANCE SO
SEVERE THREAT SEEMS LESSENED BUT STILL CERTAINLY NON-ZERO. `SEVERE
SHOWERS` A LIKELY THREAT DUE TO LOW LEVEL WIND SPEED/STORM
MOTION/LACK OF INSTABILITY. STRONG CAA FRIDAY NIGHT INTO SATURDAY TO
BRING SLIGHTLY BELOW CLIMO TEMPS FOR THE REST OF THE PERIOD WHILE
SKY CLEARS OUT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...PROGRESSIVE FLOW IN PLACE AT THE START OF THE
PERIOD WITH ZONAL MID LEVEL FLOW QUICKLY SPREADING ACROSS THE
SOUTHEAST. LARGE AREA OF SURFACE HIGH PRESSURE WILL ALSO BE NEARING
THE COAST MAKING SUNDAY ONE LAST DAY OF NEAR TO SLIGHTLY BLOW CLIMO
TEMPS. THIS HIGH WILL END UP OFFSHORE BY MONDAY LEADING TO MILDER
WEATHER AND THE RETURN FLOW OF SOME MOISTURE. THIS MAY EITHER SIMPLY
TAKE THE FORM OF SOME CLOUDINESS OR SOME LOW RAIN CHANCES SHOULD A
COASTAL TROUGH DEVELOP AS INDICATED BY SOME MODELS. HIGH PRESSURE
WILL SIMILARLY BE FOUND WELL OFF THE COAST ON TUESDAY WHILE A COLD
FRONT LIES ALIGNED WITH THE ZONAL FLOW SOMEWHERE NEAR THE
MASON-DIXON LINE. WHILE RAIN CHANCES REMAIN TOUGH TO RULE OUT THERE
STILL REALLY ISNT MUCH FOR A TRIGGERING MECHANISM ESPECIALLY GIVEN
THE BROAD UPPER HIGH OVER THE GOMEX/CARIBBEAN. UPPER FLOW WILL TILT
TO MORE SW ON WED AS STORM SYSTEM DEVELOPS OVER TN/MS VALLEY AREAS
POSSIBLY LEADING TO A SLIGHT INC IN POPS LOCALLY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...LOOKS LIKE CONVECTION OFF OF FLORIDA MAY HAVE STOLEN
MUCH OF THE ENERGY FOR PRECIP IN OUR AREA...CERTAINLY OVER OUR
SOUTHERN PORTION OF THE CWA. BAROCLINIC LEAF TO THE NORTH AND
ASSOCIATED PCPN WILL LIKELY SCRAPE ACROSS THE NORTHERN PORTIONS OF
THE ILM CWA...WITH LBT AND POSSIBLY FLO HAVING SHRA IN THE VICINITY.
HRRR HAS MUCH OF THE PCPN DYING OUT AS IT MOVES INTO THE EASTERN
CAROLINAS...LIKELY DUE TO LOW LEVEL MARINE INFLUENCES...IE. WINDS
200 AT 10G20KT. LOW LEVEL MOISTURE SHOULD BE SUFFICIENT ENOUGH TO
PRODUCE LOW STRATUS CEILINGS TOWARD DAYBREAK. BUFKIT SHOWS STRONG
SPEED SHEAR...MAINLY FROM 500 FT TO 1500 FT...AND HAVE ADDED WIND
SHEAR TO THE TERMINALS FOR THIS MORNING. INLAND COULD SEE THE
STRATUS AT TIMES DROP TO THE SFC WHICH WILL HINDER HORIZONTAL VSBY.
IMPROVING CEILING AND VSBY CONDITIONS BY 15Z-16Z. HOWEVER...EXPECT
CONTINUED GUSTY WEST SOUTHWEST WINDS THROUGHOUT TODAY...WITH WINDS
BACKING SLIGHTLY TO THE SW OR SSW THIS AFTERNOON AND EVENING.
EXTENDED OUTLOOK...EXPECT VFR THROUGH THURSDAY. MODERATE CONFIDENCE
FOR SHOWERS FRIDAY THROUGH MID AFTERNOON. VFR SAT THROUGH MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM THURSDAY...SCA CONDITIONS FOR ALL WATERS BY
DAYBREAK...AND CONTINUING THROUGH DAYBREAK SATURDAY. WAA OVER THE
COOLER SHELF WATERS WILL BE A DETERRENT FOR THE STRONGER WINDS ALOFT
FROM MIXING DOWN. HOWEVER...A TIGHTENED SFC PG THROUGHOUT THE NEAR
TERM...WILL PRODUCE SW WINDS IN THE 15 TO 25 KT RANGE...WITH A FEW
GUSTS TO 30 KT ACROSS THE OUTER WATERS OFF CAPE FEAR WHERE SSTS ARE
IN THE 60S IN TURN ALLOWING WINDS ALOFT TO MIX TO THE OCEAN SFC.
SEAS WILL RANGE BETWEEN 3 AND 6 FT...EXCEPT FOR THE WATERS BETWEEN
CAPE FEAR TO MURRELLS INLET...WHERE SEAS WILL BE HIGHER BY 2 TO 3
FT...IE. 5 TO 9 FT...DUE TO AN INCREASED FETCH AND A FAVORABLE WIND
DIRECTION. THE DECAYING ESE 10-12 SECOND PERIOD SWELL OF THE PAST
SEVERAL DAYS HAS GIVEN UP TO THE LOCALLY PRODUCED SHORT PERIOD WIND
DRIVEN WAVES EXHIBITING 5 TO 8 SECOND PERIODS. THE ENERGY FROM THESE
WAVES BY FAR ENCOMPASS THE SIGNIFICANT SEAS THRUOUT THE NEAR TERM AS
WITNESSED WITH THE LATEST AND PROGGED SPECTRAL DENSITY CHARTS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...DYNAMIC COLD FRONT TO KEEP A SOLID SMALL CRAFT
ADVISORY IN EFFECT ON FRIDAY. FRIDAY EVENING FROPA TO YIELD A SHARP
VEER AND A CONTINUATION OF SCA WINDS IN THE COLD SURGE EVEN AS THE
OFFSHORE COMPONENT OF THE WINDS STARTS TO KNOCK DOWN THE OVERALL
HEIGHT OF THE SEAS FIRST ALONG SHORE. BY SATURDAY THINGS WILL HAVE
SETTLED TO WHERE A SCEC WILL BE NEEDED AND CONTINUED IMPROVEMENT IN
CONDITIONS SLATED FOR THE AFTERNOON AND EVENING HOURS ALBEIT
SOMEWHAT GRADUAL IN NATURE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...SUNDAY BRINGS PROGRESSIVE AREA OF HIGH
PRESSURE THAT WILL GO FROM BEING OVER THE LANDMASS IN THE MORNING TO
OFF THE COAST BY EVENING. MODERATE NE WINDS TO START WILL VEER AND
LIGHTEN AS THE DAY WEARS ON WITH A CORRESPONDING ABATEMENT OF WAVE
HEIGHT. ADDITIONAL VEERING IS IN STORE FOR MONDAY BUT THE DEGREE OF
WIND CHANGE IS UNCERTAIN PENDING WHETHER OR NOT A COASTAL TROUGH
MANAGES TO DEVELOP. EVEN SO THERE WILL BE A PREDOMINANTLY ONSHORE
FLOW AND SEAS LIKELY IN THE 2 TO 3 FT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 7 AM EST SATURDAY
FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/HDL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
320 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT. A STRONG COLD
FRONT WILL PASS THROUGH THE REGION FRIDAY NIGHT. HIGH PRESSURE OVER
THE WESTERN GULF SATURDAY WILL BE CENTERED OVER THE CAROLINAS SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM WED...LINE OF SHOWERS ASSOC WITH AN UPPER LEVEL
SHORTWAVE MOVING ACROSS CENTRAL NC EARLY THIS MORNING AND WILL
PUSH ACROSS THE CWA BETWEEN 0730Z AND 12Z. HRRR AND OTHER LOCAL
MESOSCALE MODELS INDICATING THIS LINE WILL WEAKEN AS MOVE ACROSS
ERN NC. BEST CHANCE OF SHOWER WILL BE N OF HIGHWAY 70 AS IT MOVES
INTO THE CWA AND THEN N OF 264 AS IT MOVES EAST OF A WASHINGTON TO
PLYMOUTH LINE WITH SRN SECTIONS SEEING LIMITED SHOWER ACTIVITY.
COULD SEE SOME MODERATE TO HEAVY SHOWERS AND WIND GUSTS TO AROUND
25-30 MPH AS THE LINE MOVES INTO NWRN SECTIONS BUT EXPECT IMPACTS
TO EASE AS THE LINE PUSHES FARTHER EAST AND WEAKENS. THE REST OF
THE FORECAST LOOKS IN GOOD SHAPE WITH MODERATE SWLY FLOW AND TEMPS
HOLDING IN THE 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
AS OF 330 PM WED...WEAK DISTURBANCE WILL BE OFFSHORE BY THURS
MORNING WITH A MODERATE SOUTHWESTERLY PRESSURE GRADIENT PERSISTING
THROUGHOUT THE DAY. WINDS WILL GUST UPWARDS OF 20 MPH THROUGH LATE
AFTERNOON. FORECAST SOUNDINGS SUGGEST STRATOCU DEVELOPMENT BY
EARLY AFTERNOON BUT WITH LITTLE IMPACT ON SENSIBLE WEATHER. LOW
LEVEL THICKNESSES INCREASE AGAIN THURS WHICH COUPLED WITH STRONG
INSULATION WILL BUILD TEMPS INTO THE MID 70S ACROSS THE
REGION...SEVERAL DEGREES ABOVE CLIMO FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY THROUGH THURSDAY/...
AN APPROACHING FRONT WILL CROSS THE AREA FRIDAY NIGHT AND MOVE
OFFSHORE SATURDAY MORNING. MODEL CONCENSUS HAS BEEN LACKING ON
BOTH THE TIMING AND OVERALL MAGNITUDE...WITH THE GFS/NAM STILL THE
FASTER/SLIGHTLY WEAKER OF THE SOLUTIONS...BRINGING THE FRONT
THROUGH FRIDAY EVENING WITH A MORE SLIT ENERGY SOLUTION. THE
UKMET/EURO SOLUTION BRINGS THE FRONT THROUGH EARLY SATURDAY WITH A
MORE PHASED SOLUTION. EITHER WAY...STRONG SOUTHERLY WINDS WILL
INCREASE FRIDAY AHEAD OF THE FRONT WITH PRECIPITATION CHANCES
INCREASING AS WE GO THROUGH THE DAY. THE GFS HAS THE PRECIP
CONFINED MAINLY TO THE SOUTH AND ALONG THE COAST...WHILE THE EURO
STILL MAINTAINS SFC/UPPER LEVEL PHASE WITH A SOLID BAND OF
PRECIPITATION MOVING THROUGH THE AREA. WITH THE TIMING OF THE
FRONT MOVING THROUGH THE AREA LATE EVENING THROUGH THE
OVERNIGHT...THIS WOULD TAP INTO THE DIURNAL PEAK OF INSTABILITY.
SB/MUCAPE HAS A RANGE FROM 100-400 J/KG DEPENDING ON THE MODEL OF
CHOICE WITH AMPLE AMOUNT OF SHEAR. ALSO...0-1KM SHEAR LOOKS BEST
JUST EAST OF 1-95 THROUGH THE AFTERNOON/EVENING WITH THE 850MB LLJ
AROUND 60 KTS..ESPECIALLY OFFSHORE. GIVEN THE LOW CAPE/HIGH SHEAR SET
UP...CAN NOT RULE OUT CONVECTION FORMATION AS THE FRONT NEARS WITH
A SLGT RISK ACROSS EASTERN NC BY SPC. IF STORMS
GENERATE...ANTICIPATE THE HIGHEST RISK TO BE ASSOCIATED WITH
STRAIGHT LINE WINDS. CONVECTION COULD BE LIMITED BY CLOUD COVER.
HOWEVER...WITH ENOUGH LIFT...ESPECIALLY NEAR 850MB...CONVECTION
COULD STILL BECOME ELEVATED. ALSO...MIGHT AS WELL MENTION THE
POSSIBILITY OF ANY BREAKS IN THE CLOUDS DURING THE DAY
FRIDAY...INCREASING TEMPS...WHICH WILL SUBSEQUENTLY INCREASE
INSTABILITY IN THE LOWEST LEVELS. GIVEN THIS...HAVE MAINTAINED ISO
THUNDER FRIDAY MORNING THROUGH FRIDAY EVENING.
PRECIPITATION WILL TAPPER OFF EARLY SATURDAY MORNING AS THE FRONT
MOVES OFFSHORE WITH WINDS VEERING TO THE NW AS THE UPPER TROUGH
SWINGING OVERHEAD THROUGH THE AFTERNOON. WITH PLENTY OF BOUNDARY
LAYER MIXING...ANTICIPATE STRONG NWLY FLOW. SKIES SHOULD SLOWLY
CLEAR AS THE MID/UPPER LEVEL LIFT MOVES OFFSHORE. EXPECT CAA TO
PUSH THROUGH THE AREA THROUGH THE WEEKEND. HIGH PRESSURE WILL MOVE
OVERHEAD SUNDAY AND MOVE OFFSHORE SUNDAY NIGHT WITH RETURN FLOW
DEVELOPING THEREAFTER.
MODELS START TO DIVERGE AT THIS POINT WITH THE GFS ILLUSTRATING A
SERIES OF SHORTWAVES TRAVERSING THE AREA FROM MONDAY THROUGH
WEDNESDAY AHEAD OF A MORE IMPRESSIVE FRONTAL SYSTEM PROGGED TO CROSS
THE AREA LATE WEDNESDAY/EARLY THURSDAY. THE 23/12Z EURO DOES NOT
SHOW THESE FEATURES AS READILY. HOWEVER...A QUICK PEAK AT THE 00Z
EURO DOES SHOW SOME SIGNATURE OF A SHORTWAVE MOVING OVERHEAD SUNDAY
NIGHT/EARLY MONDAY. WITH LITTLE LOW LEVEL MOISTURE AND LIFT...ONLY
EXPECT SOME CLOUDS TO DEVELOP SUNDAY NIGHT THROUGH EARLY MONDAY
MORNING. GIVEN MODEL DISCONTINUITY BEYOND MONDAY...WILL HIGHLIGHT
THE INCREASE CHANCE IN PRECIPITATION EARLY TUESDAY AND THROUGH THE
DAY WEDNESDAY AS SFC FEATURES CROSS THE AREA.
TEMPS WILL BE TRICKY ON FRIDAY AS THE FRONT APPROACHES. IF CLOUD
COVER LACKS THROUGH THE EARLY MORNING HOURS THIS WILL ALLOW TEMPS TO
CLIMB A BIT HIGHER THAN FORECASTED. TEMPS SHOULD INCREASE INTO THE
LOW/MID 70S FRIDAY. AS THE FRONT CROSSES...FEEL WITH CLOUD COVER
IN PLACE AND CAA JUST BEGINNING WITH PLENTY OF MIXING...TEMPS
WILL FALL INTO THE UPPER 30S/LOWER 40S. AS CLOUDS BEGIN TO CLEAR
WITH CONTINUED BOUNDARY LAYER MIXING...EXPECT TEMPS TO CLIMB INTO
THE LOWER 50S SATURDAY...WHICH IS ALSO SUPPORTED BY THE MHX
THICKNESS STUDY. WITH CLEARING AND CALMING WINDS...TEMPS WILL FALL
INTO THE LOWER 30S INLAND/LOWER 40S ALONG THE COAST SATURDAY
NIGHT. TEMPS WILL BE A TAD LOWER SUNDAY WITH LESS
MIXING...LOWERING LOW LEVEL THICKNESS AND CONTINUED CAA AS HIGH
PRESSURE MOVES OVERHEAD. TEMPS IN THE LOWER 50S. AS THE HIGH MOVES
OFFSHORE...ANTICIPATE RETURN FLOW WITH BETTER CLOUD
COVERAGE...ALLOWING TEMPS TO CLIMB BACK INTO THE 60S THROUGH THE
FIRST PART OF NEXT WEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/
AS OF 100 AM THU...LINE OF SHOWERS ASSOC WITH THE UPPER LEVEL
DISTURBANCE MOVING THROUGH CENTRAL NC EARLY THIS MORNING. LEAD
TIME OF ARRIVAL PUSHES THIS LINE INTO PGV AROUND 0730Z AND ISO
AROUND 0800Z...HOWEVER HRRR SHOWING THIS LINE WEAKENING AS IT
PUSHES EAST OF THE TRIANGLE AND ESSENTIALLY DISSIPATING ALONG ITS
SRN SECTIONS WITH LITTLE IMPACT BY THE TIME IT REACHES OAJ AND
EWN. WILL CONTINUE TO INDICATE NON CONVECTIVE LLWS LATE TONIGHT
AS SW LLJ INCREASES. GUIDANCE AGAIN APPEARING TOO PESSIMISTIC WITH
CIGS DROPPING TO IFR BETWEEN 10-13Z...AND DID NOT GO WITH THIS TREND
GIVEN THE MIXED BOUNDARY LAYER PREVENTING LOW STRATUS DEVELOPMENT.
TROUGH MOVES OFFSHORE FOR THUR...AND MOSTLY SUNNY SKIES SAVE FOR
CIRRUS CAN BE EXPECTED. A FEW FAIR WEATHER CU AGAIN POSSIBLE BY
AFTERNOON AS BOUNDARY LAYER MIXES OUT TO AROUND 5 K FT. WINDS WILL
GUST UPWARDS OF 20 KT DUE TO THE EFFICIENT MIXING.
LONG TERM /FRIDAY THROUGH TUESDAY/
LOW LEVEL MOISTURE WILL INCREASE WITH SUB-VFR CONDITIONS DEVELOPING
AS PRECIPITATION MOVES INTO THE AREA FRIDAY THROUGH SATURDAY
MORNING. CONDITIONS WILL QUICKLY IMPROVE SATURDAY AS DRY AIR
INFILTRATES THE REGION. EXPECT PLEASANT FLYING CONDITIONS SUNDAY
WITH CLOUDS AGAIN INCREASING MONDAY. LOW LEVEL MOISTURE WILL
INCREASE MONDAY AFTERNOON AS ANOTHER FRONT APPROACHES THE AREA
WITH CONDITIONS DETERIORATING MONDAY NIGHT THOUGHT MUCH OF
WEDNESDAY WITH INCREASED CHANCES OF PRECIPITATION.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/
AS OF 1030 PM WED...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SOUTHWESTERLY WINDS INC TO 15 KNOTS OR MORE. 41036 HAS REMAINED
AROUND 5 FT...WITH FRYING PAN BUOY SE OF CAPE FEAR INCREASING TO 7
FT. 4 TO 7 FOOT SEAS OVERNIGHT INTO THUR SEEM JUSTIFIED. SOUTHWESTERLY
WINDS WILL INCREASE TO 20 TO 25 KT AFTER MIDNIGHT AHEAD OF A WEAK
UPPER LEVEL DISTURBANCE PASSING NORTH OF THE WATERS. THE STRONGEST
WINDS WILL MAINLY IMPACT THE CENTRAL AND SOUTHERN WATERS FROM
OREGON INLET SOUTH. NO CHANGES TO CURRENT SCA HEADLINES. WINDS
WILL DIMINISH TO 15 TO 20 KNOTS THURS AFTERNOON BUT SEAS WILL
REMAIN ELEVATED ESPECIALLY FOR THE OUTER FRINGES OF THE COASTAL
WATERS.
LONG TERM /FRIDAY THROUGH TUESDAY/
THE PRES GRADIENT WILL CONTINUE TO TIGHTEN FRIDAY MORNING AS A
RESULT WINDS WILL INCREASE TO AROUND 15-25KTS ACROSS ALL THE
WATERS WITH GUSTS AT OR JUST ABOVE 30KT ON FRIDAY. WINDS WILL VEER
AS THE FRONT PASSES WITH A W-NW SURGE DEVELOPING IN THE CAA
PATTERN SATURDAY. WINDS WILL CONTINUE AROUND 20-25KTS BEFORE
DECREASING AS THE SURGE WANES LATE SATURDAY. CONDITIONS IMPROVE
SAT NIGHT INTO SUNDAY MORNING WITH WINDS AND SEAS SUBSIDING AS
HIGH PRESSURE MOVES OVERHEAD. WINDS WILL INCREASE FROM THE SOUTH
MONDAY AFTERNOON THROUGH TUESDAY AS THE SFC GRADIENT TIGHTENS
AHEAD OF ANOTHER FRONT. WINDS RELAX FOR A BRIEF TIME LATE TUESDAY
THROUGH EARLY WEDNESDAY BEFORE ANOTHER SFC FEATURE APPROACHES
LATER IN THE WEEK WITH INCREASED SOUTHERLY FLOW AS A RESULT.
WAVE HEIGHTS WILL BE BUILDING TO 4-7 FT EARLY FRIDAY AS A RESULT OF
THE INCREASING SW WINDS. EXPECT SEAS TO PEAK IN THE 7-10FT RANGE
ACROSS THE OUTER WATERS...ESPECIALLY FRIDAY AFTERNOON/EVENING. SEAS
WILL SLOWLY SUBSIDE SATURDAY IN RESPONSE TO OFFSHORE WINDS FROM THE
WNW. ANTICIPATE WAVES TO BUILD IN THE BEGINNING PART OF THE WEEK IN
RESPONSE TO THE INCREASED SOUTHERLY FLOW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ152-154-156-
158.
&&
$$
SYNOPSIS...SK/DAG
NEAR TERM...TL
SHORT TERM...DAG
LONG TERM...LEP
AVIATION...SK/LEP
MARINE...BTC/DAG/TL/LEP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
122 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE ACROSS THE AREA TONIGHT. A STRONG COLD
FRONT WILL PASS THROUGH THE REGION FRIDAY NIGHT. HIGH PRESSURE OVER
THE WESTERN GULF SATURDAY WILL BE CENTERED OVER THE CAROLINAS SUNDAY
AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 100 AM WED...LINE OF SHOWERS ASSOC WITH AN UPPER LEVEL
SHORTWAVE MOVING ACROSS CENTRAL NC EARLY THIS MORNING AND WILL
PUSH ACROSS THE CWA BETWEEN 0730Z AND 12Z. HRRR AND OTHER LOCAL
MESOSCALE MODELS INDICATING THIS LINE WILL WEAKEN AS MOVE ACROSS
ERN NC. BEST CHANCE OF SHOWER WILL BE N OF HIGHWAY 70 AS IT MOVES
INTO THE CWA AND THEN N OF 264 AS IT MOVES EAST OF A WASHINGTON TO
PLYMOUTH LINE WITH SRN SECTIONS SEEING LIMITED SHOWER ACTIVITY.
COULD SEE SOME MODERATE TO HEAVY SHOWERS AND WIND GUSTS TO AROUND
25-30 MPH AS THE LINE MOVES INTO NWRN SECTIONS BUT EXPECT IMPACTS
TO EASE AS THE LINE PUSHES FARTHER EAST AND WEAKENS. THE REST OF
THE FORECAST LOOKS IN GOOD SHAPE WITH MODERATE SWLY FLOW AND TEMPS
HOLDING IN THE 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
AS OF 330 PM WED...WEAK DISTURBANCE WILL BE OFFSHORE BY THURS
MORNING WITH A MODREATE SOUTHWESTERLY PRESSURE GRADIENT PERSISTING
THROUGHOUT THE DAY. WINDS WILL GUST UPWARDS OF 20 MPH THROUGH LATE
AFTERNOON. FORECAST SOUNDINGS SUGGEST STRATOCU DEVELOPMENT BY
EARLY AFTERNOON BUT WITH LITTLE IMPACT ON SENSIBLE WEATHER. LOW
LEVEL THICKNESSES INCREASE AGAIN THURS WHICH COUPLED WITH STRONG
INSOLATION WILL BUILD TEMPS INTO THE MID 70S ACROSS THE
REGION...SEVERAL DEGREES ABOVE CLIMO FOR LATE FEBRUARY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
SW FLOW WILL CONTINUE TO STRENGTHEN THURSDAY NIGHT AHEAD OF A
COLD FRONT PROGGED TO CROSS THE AREA LATE FRIDAY. MODELS HAVE NOT
HANDLED THIS SYSTEM WELL WITH CONTINUITY LACKING ON TIMING AND
MAGNITUDE. THE GFS IS AMONG THE FASTER SOLUTION WHICH BRINGS THE
FRONT THROUGH FRIDAY EVENING WHERE AS THE 22/12Z EURO CONTINUES TO
BE AMONG THE SLOWER SOLUTIONS BRINGING THE FRONT THROUGH EARLY
SATURDAY MORNING. A MIDDLE OF THE ROAD SOLUTION IS FAVORED FOR NOW
GIVEN THE LARGE MODEL SPREAD WHICH BRINGS THE MAIN COLD FRONT
THRU LATER FRI EVE TO AROUND MIDNIGHT AT THE COAST.
THE TIMING OF AN EVENING COLD FROPA WILL ALLOW DIURNAL INSTABILITY
TO BE MAXIMIZED (300 J/KG SEEN VIA NAM BUFR DATA) WHEN A 50 KT LOW
LEVEL JET WILL MOVE OVER THE AREA. WITHIN THE LOW CAPE/HIGH SHEAR
ENVIRONMENT...BELIEVE THERE WILL BE A RELATIVELY SHORT OPPORTUNITY
FOR STRONGER CONVECTION TO PRODUCE GUSTY TO POSSIBLY DAMAGING
WINDS VIA WET MICROBURST DURING THE MID TO LATE AFTN HOURS ON
FRIDAY.
DRIER AND COOLER AIR WILL FILTER INTO THE AREA SATURDAY AS THE SFC
FRONT AND MID LEVEL WAVE MOVE OFF THE EASTERN SEABOARD. LOW LEVEL
THICKNESS WILL ONLY SUPPORT HIGH TEMPS IN THE LOWER TO MID 50S
THIS WEEKEND FOR MOST AREAS DESPITE PLENTIFUL SUNSHINE. WITH GOOD
RADIATIONAL COOLING CONDITIONS LOWS SAT NIGHT LIKE SUBFREEZING
OVER INLAND AREAS.
A WEAK SOUTHERN STREAM SHORT WAVE MOVING OFF THE SE COAST BRINGS
CLOUDS AND SLIGHT/LOW CHANCE PCPN CHANCES BACK INTO THE FCST ON
MONDAY. UNSETTLED WEATHER CONDITIONS MAY PERSIST TUE/WED AS A WEAK
FRONTAL BNDRY SETTLES OVER THE AREA BEFORE BEING PUSHED OFFSHORE
BY INCOMING NORTHERN STREAM SHORT WAVE LATE WED. TEMPS WILL AVERAGE
NEAR TO SLIGHTLY ABV SEASONAL NORMS DURING THE EARLY TO MID WEEK
FCST PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/
AS OF 100 AM THU...LINE OF SHOWERS ASSOC WITH THE UPPER LEVEL
DISTURBANCE MOVING THROUGH CENTRAL NC EARLY THIS MORNING. LEAD
TIME OF ARRIVAL PUSHES THIS LINE INTO PGV AROUND 0730Z AND ISO
AROUND 0800Z...HOWEVER HRRR SHOWING THIS LINE WEAKENING AS IT
PUSHES EAST OF THE TRIANGLE AND ESSENTIALLY DISSIPATING ALONG ITS
SRN SECTIONS WITH LITTLE IMPACT BY THE TIME IT REACHES OAJ AND
EWN. WILL CONTINUE TO INDICATE NON CONVECTIVE LLWS LATE TONIGHT
AS SW LLJ INCREASES. GUIDANCE AGAIN APPEARING TOO PESSIMISTIC WITH
CIGS DROPPING TO IFR BETWEEN 10-13Z...AND DID NOT GO WITH THIS TREND
GIVEN THE MIXED BOUNDARY LAYER PREVENTING LOW STRATUS DEVELOPMENT.
TROUGH MOVES OFFSHORE FOR THUR...AND MOSTLY SUNNY SKIES SAVE FOR
CIRRUS CAN BE EXPECTED. A FEW FAIR WEATHER CU AGAIN POSSIBLE BY
AFTERNOON AS BOUNDARY LAYER MIXES OUT TO AROUND 5 K FT. WINDS WILL
GUST UPWARDS OF 20 KT DUE TO THE EFFICIENT MIXING.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
SUB-VFR CONDITIONS EXPECTED AS PRECIPITATION MOVES INTO THE AREA
FRIDAY THROUGH SATURDAY MORNING. CONDITIONS WILL QUICKLY IMPROVE
SATURDAY AS DRY AIR INFILTRATES THE REGION. EXPECT GOOD FLYING
CONDITIONS SUNDAY WITH CLOUDS AGAIN INCREASING MONDAY. FLOW LEVEL
MOISTURE WILL INCREASE MONDAY AFTERNOON AS ANOTHER FRONT
APPROACHES THE AREA WITH CONDITIONS DETERIORATING MONDAY NIGHT
INTO TUESDAY WITH AN INCREASED CHANCE OF PRECIPITATION.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/
AS OF 1030 PM WED...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SOUTHWESTERLY WINDS INC TO 15 KNOTS OR MORE. 41036 HAS REMAINED
AROUND 5 FT...WITH FRYING PAN BUOY SE OF CAPE FEAR INCREASING TO 7
FT. 4 TO 7 FOOT SEAS OVERNIGHT INTO THUR SEEM JUSTIFIED. SOUTHWESTERLY
WINDS WILL INCREASE TO 20 TO 25 KT AFTER MIDNIGHT AHEAD OF A WEAK
UPPER LEVEL DISTURBANCE PASSING NORTH OF THE WATERS. THE STRONGEST
WINDS WILL MAINLY IMPACT THE CENTRAL AND SOUTHERN WATERS FROM
OREGON INLET SOUTH. NO CHANGES TO CURRENT SCA HEADLINES. WINDS
WILL DIMINISH TO 15 TO 20 KNOTS THURS AFTERNOON BUT SEAS WILL
REMAIN ELEVATED ESPECIALLY FOR THE OUTER FRINGES OF THE COASTAL
WATERS.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
THE PRES GRADIENT WILL CONTINUE TO TIGHTEN THURSDAY EVENING AND
AS A RESULT WINDS WILL INCREASE TO AROUND 15-25KTS ACROSS ALL THE
WATERS WITH GUSTS NEAR 30KT ON FRIDAY. WINDS WILL VEER AS THE
FRONT PASSES WITH A W-NW SURGE DEVELOPING IN THE CAA PATTERN
SATURDAY. WINDS WILL CONTINUE AROUND 20-25KTS BEFORE DECREASING
AS THE SURGE WANES LATE SATURDAY. CONDITIONS IMPROVE SAT NIGHT
INTO SUNDAY MORNING WITH WINDS AND SEAS SUBSIDING. WINDS WILL
INCREASE FROM THE SOUTH MONDAY AFTERNOON THROUGH TUESDAY AS THE
SFC GRADIENT TIGHTENS AHEAD OF ANOTHER COLD FRONT.
WAVE HEIGHTS WILL BE BUILDING TO 4-7 FT LATE THURSDAY NIGHT INTO
EARLY FRIDAY AS A RESULT OF THE INCREASING SW WINDS. EXPECT SEAS
TO PEAK IN THE 7-10FT RANGE ACROSS THE OUTER WATERS...ESPECIALLY
FRIDAY AFTERNOON/EVENING. SEAS WILL SLOWLY SUBSIDE SATURDAY IN
RESPONSE TO OFFSHORE WINDS FROM THE WNW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST SUNDAY FOR AMZ152-154-156-
158.
&&
$$
SYNOPSIS...SK/DAG
NEAR TERM...SK
SHORT TERM...DAG
LONG TERM...BTC/LEP
AVIATION...BTC/SK
MARINE...BTC/DAG/TL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1133 AM CST THU FEB 23 2012
.DISCUSSION...NARROW BAND OF MODERATE SNOWFALL HAS SET UP FROM
GRAND FORKS TO COOPERSTOWN...AND SOUTHWEST INTO SOUTHCENTRAL NORTH
DAKOTA. THIS SNOWFALL IS ASSOCIATED WITH LOW-MID LEVEL
FRONTOGENESIS ALONG WINDSHIFT (COLD FRONT). HRRR APPEARS TO HAVE A
DECENT HANDLE ON THIS SNOWBAND...PROPAGATING IT TO THE SOUTHEAST
AFFECTING SOUTHEAST NORTH DAKOTA AND ADJACENT AREAS IN MINNESOTA
THIS AFTERNOON. DURATION WILL BE BRIEF...BUT HIGH SNOWRATES SHOULD
LEAD TO 1-2 INCHES OF NEW SNOW. UPDATED FORECAST TO INCREASE POPS
AND SNOW AMOUNTS ACROSS THIS AREA. WILL MONITOR TRENDS AND UPDATE
AGAIN IF NEEDED.
&&
.AVIATION...SCATTERED SNOW SHOWERS POSSIBLE. LIGHT WINDS THIS
MORNING WILL SHIFT TO THE WEST AND NORTHWEST THIS AFTN OVER ERN ND
AND OVER NW MN THIS EVE AND BE A BIT BREEZY AT TIMES INTO FRIDAY
IN THE 15 TO 20 KT RANGE. ANY REMAINING VFR CIGS WILL BECOME MVFR
BY THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 953 AM CST THU FEB 23 2012/
DISCUSSION...CONCERN TODAY WILL BE SNOW CHANCES AND TEMPERATURES.
SHORTWAVE TO THE NORTH WILL DROP SOUTH TO NEAR WINNIPEG BY
00Z. THERE IS A WEAK 700MB BAROCLINIC ZONE THAT WILL TRANSITION
EASTWARD THROUGH THE FA TODAY AS A RESULT. TIMED 50%
POPS/SCATTERED SNOW SHOWERS FROM WEST TO EAST WITH THIS
MID-LEVEL FRONTOGENESIS. SNOWFALL ACCUMULATIONS SHOULD REMAIN
BELOW AN INCH. CURRENT RADAR ANALYSIS CONFIRMS THIS THINKING.
THE 1/4 FOG ACROSS THE NORTHEAST FA WILL QUICKLY IMPROVE AS CLOUDS
MOVE IN. NOT SURE HOW TEMPERATURES ARE GOING TO RESPOND
TODAY...BUT GIVEN AIRMASS TEMPS UPPER 20S TO NEAR 30F SEEMS
REASONABLE.
PREV DISCUSSION... /ISSUED 351 AM CST THU FEB 23 2012/
SHORT TERM...
A WIDE VARIETY OF CONDITIONS OVER THE FCST AREA EARLY THIS
MORNING. THIS WILL MAKE EXACT TEMP FCSTS THROUGH THIS MORNING
QUITE DIFFICULT. LARGE CLEAR HOLE GRAND FORKS TO THIEF RIVER FALLS
DOWN TO FARGO...FERGUS FALLS AND PARK RAPIDS. IN THIS CLEAR HOLE
TEMPS HAVE FALLEN INTO THE SINGLE DIGITS IN MANY AREAS AND ALSO
PATCHES OF DENSE FOG HAS FORMED. CLOUDS MOVING IN FROM THE
NORTHWEST INTO NORTHEAST ND SHOULD CONTINUE TO ADVANCE SOUTHEAST
OVER THE NEXT FEW HOURS AND AS IT DOES SHOULD CAUSE TEMPS TO RISE
AND EVENTUALLY THE PATCHES OF FOG TO SHRINK. THAT SAID WILL
MENTION AREAS OF FOG THRU 15Z FOR GFK-BJI-PKD-FAR AREA AS
CONDITIONS WILL REMAIN HIGHLY VARIABLE.
AS FOR PRECIP...SYSTEM DROPPING THRU THE WRN DAKOTAS ATTM WITH SFC
LOW MOVING INTO NORTHWEST-NORTH CENTRAL SOUTH DAKOTA AT 09Z. MAIN
SNOW BAND REMAINING MISSOURI RIVER AND WESTWARD...AND FEEL ANY
THREAT FOR LIGHT SNOW WITH THIS SYSTEM IN OUR WRN FCST AREA
REMAINS QUITE LOW. WATER VAPOR SHOWS A SMALL VORT MAX MOVING THRU
SRN MANITOBA AND RADARS SHOW A SMALL AREA OF LIGHT SNOW DROPPING
SOUTHEAST FROM THE MORDEN AREA INTO HALLOCK-CAVALIER. THIS AREA OF
LIGHT SNOW IS PROGGED TO MOVE EAST-SOUTHEAST TOWARD LAKE OF THE
WOODS REGION THIS MORNING. AS SOUTH DAKOTA SYSTEM MOVES FAR ENOUGH
SOUTH....WINDS WILL SHIFT TO THE WEST-NORTHWEST OVER ERN ND AS
COLDER AIR AT 850 MB ADVECTS IN. AS IT DOES...UPSTREAM OBS SHOWS
PLENTY OF CLOUDS AND SPOTTY -SN. WILL MAINTAIN SOME LOW POPS FOR
SPOTTY -SN THIS AFTN AND MAINTAIN THIS TONIGHT.
FRIDAY WILL SEE UPPER LOW OVER WCNTRL MANITOBA DROP INTO NRN MN
AND WILL MAINTAIN SOME -SN WITH THIS...WITH MINIMAL AMTS. TEMPS
EARLY TODAY WILL BE HIGHLY VARIABLE AND DEPENDENT ON CLOUD
COVER....BUT BY MID AFTN MOST SITES SHOULD SEE HIGHS IN THE UPPER
20S TO LOWER 30S. COOLER FOR TONIGHT INTO FRIDAY AND A BIT BREEZY
AS WELL WITH NORTHWEST WINDS.
BRIEF CLEARING WILL MOVE IN FRIDAY NIGHT BEFORE MID AND HIGH LEVEL
CLOUDS IN ADVANCE OF NEXT SYSTEM MOVE IN ON SATURDAY. WILL START
TO BRING IN LIKELY POPS SAT NIGHT INTO DVL REGION WITH CHC POPS
ELSEWHERE...MOSTLY AFTER MIDNIGHT.
LONG TERM (SUN-WED)...
ALL MODELS CONTINUED A NORTHWARD DRIFT TO THE OVERALL SYSTEM ON
THE 00Z SUITE. ALSO TREND WAS A BIT WEAKER WITH A BIT LESS
QPF/SNOWFALL AMTS. SYSTEM INITIALLY MORE MID AND UPPER LEVEL
FOCUSED AS 500 MB LOW MOVES OUT OF SRN SASK INTO NRN ND SUNDAY
MORNING. THUS INITIALLY SNOW WILL BE MOSTLY FROM SRN SASK INTO NRN
ND. DURING THE DAY ON SUNDAY...SFC LOW WILL BETTER ORGANIZE IN ERN
SD AND MOVE INTO CNTRL MN WITH 500-700 MB LOWS STRENGTHENING
CLOSER TO SFC LOW. THUS EXPECT A RE-DEVELOPMENT OR SHIFTING TO
SNOW AREA TO MORE OVER WCNTRL-NW-CNTRL MN BY LATE SUNDAY. WINDS
STILL DONT APPEAR TERRIBLE..WITH 850 MB WINDS PROGGED NR 25 KTS.
QUESTIONS REMAIN IN HOW DOES THE MINNESOTA SFC AND MID-UPPER LEVEL
FEATURES ORGANIZE ON SUNDAY. INITIAL BAND OF -SN MORE MID LEVEL
FRONTOGENESIS FOCUSED WITH FOCUS OVER THE NRN VALLEY LATE SAT
NIGHT-EARLY SUNDAY MORNING. PWATS NOT ALL THAT HIGH INCREASING TO
0.33 OR SO...SO MAY NOT BE A BLOCKBUSTER SNOWFALL STORM BUT STORM
STILL WILL BE A HAZARD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
121 PM EST THU FEB 23 2012
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OVER THE MIDDLE MISSISSIPPI VALLEY
TODAY. THE LOW WILL DEEPEN TONIGHT AS IT MOVES NORTHEAST TOWARD THE
EASTERN GREAT LAKES. A COLD FRONT WILL SWEEP ACROSS THE AREA IN
THE WAKE OF THE LOW...BRINGING MUCH COLDER AIR TO THE OHIO VALLEY
ON FRIDAY. COLD AIR ALONG WITH SNOW SHOWERS CAN BE EXPECTED FOR
THE FIRST PART OF THE WEEKEND. HIGH PRESSURE WILL RETURN TO THE
OHIO VALLEY ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST THINKING EARLY THIS AFTERNOON IS A CONTINUED EXPECTATION
FOR STORMS TO INITIATE IN SRN INDIANA BY 4 PM...AND MOVE RAPIDLY
NORTHEAST ALONG/JUST NORTH OF WARM FRONT. 1630Z SPC SWODY1
SUCCINCTLY SUMMED UP THE CONCERNS...NAMELY THE WARM SECTOR/S
MOISTURE QUALITY AND ABILITY FOR STORMS TO TAP THE MARGINAL
INSTBY. WINDOW OF 50S DEWPOINTS VERY NARROW AT 17Z OVER WRN
KY/TN...AND WHERE STORMS DEVELOP IN RELATION TO THIS WILL
DETERMINE OVERALL SEVERITY. RIGHT NOW AS IT STANDS...RUC FORECAST
SOUNDINGS EARLY THIS EVENING FOR CVG/MDN ARE ISOTHERMAL TO VERY
SLIGHTLY INVERTED FROM THE SFC TO 900MB - WHICH DOESN/T RULE OUT TORNADO
THREAT COMPLETELY...BUT PUTS SOME QUESTION. NOT SURPRISED TO SEE
SPC PULL HIGHER TOR PROBS BACK A LITTLE. GIVEN THE AMPLE LOW
LEVEL SHEAR...THESE THERMODYNAMIC PROFILES SEEMS TO FIT MORE WITH
TYPICAL OHIO VALLEY COOL- SEASON QLCS SHOULD STORMS BECOME LINEAR
AND/OR HAVE BROKEN-S FORMATIONS IN THE LINE SEGMENTS. NEW 23.12Z
SPC NMM- WRF IS AGGRESSIVE WITH A CONVECTIVE CLUSTER RUNNING ALONG
THE OHIO RIVER AND RECENT HRRR RUNS A LITTLE NORTH OF THIS.
CERTAINLY THE CLOSER ANY STORMS/STORM CLUSTERS ARE TO THE WARM
FRONT/HIGH THETA-E SOURCE...THE MORE CONCERN. WILL VERY MUCH NEED
TO BE MONITORED ON THE STORM SCALE ON HOW STORMS INTERACT/EVOLVE
WITH THE SLOWLY NORTHWARD MOVING WARM SECTOR. STILL THE MOST
CONCERNED FOR AREAS WEST OF CVG THROUGH AND THEN EAST ALONG THE
OHIO RIVER. MUCH FURTHER NORTH AND SOUNDINGS SUPPORT MORE ELEVATED
THAN SFC BASED CONVECTION.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC LOW AND ASSOCIATE S/WV WILL PIVOT NE ACRS NEW ENGLAND/SAINT
LAWRENCE RIVER VALLEY ON FRIDAY WHILE AN UPPER LEVEL TROF AND
EMBEDDED DISTURBANCES WITHIN THE FLOW BEGIN TO AFFECT THE REGION.
COLDER AIR WILL CONTINUE TO FILTER IN ON FRIDAY ALONG WITH
SCATTERED RAIN SHOWERS AND SNOW SHOWERS. PCPN SHOULD CHANGE TO ALL
SNOW BY FRIDAY NIGHT AS TEMPERATURES CONTINUE TO FALL. BY
SATURDAY...COLD UPR LVL TROF WILL BEGIN TO PIVOT NE. 850 MB COLD
POOL WILL BE AT ITS MAXIMUM RESULTING IN BELOW NORMAL TEMPERATURES
AND LINGERING SNOW SHOWERS. UPR LVL TROF WILL PUSH OFF THE
ATLANTIC SEABOARD SATURDAY NIGHT...ALLOWING SFC HIGH PRESSURE TO
BUILD INTO THE OHIO VALLEY. ON SUNDAY...SFC HIGH WILL MOVE EAST.
ALONG WITH MOSTLY SUNNY SKIES...TEMPERATURES WILL REBOUND IN THE
RETURN FLOW PATTERN ON THE BACK SIDE OF THE DEPARTING HIGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG LOW WILL MOVE THROUGH THE UPPER MIDWEST TO THE NORTHERN
GREAT LAKES REGION SUNDAY AND MONDAY...TRAILING A COLD FRONT
THROUGH THE OHIO VALLEY. MODELS DIFFER ON THE TRACK AND STRENGTH
OF THE LOW AND ITS ASSOCIATED COLD FRONT. THIS DIFFERENCE WILL
RESULT IN A HIGHER UNCERTAINTY IN THE CHANCES OF RAIN AHEAD OF THE
FRONT ON MONDAY...AND WITH ITS PASSAGE MONDAY NIGHT.
HIGH PRESSURE AND A DRY PATTERN IS IN STORE FOR TUESDAY IN THE OHIO
VALLEY. MODELS QUICKLY DIVERGE IN THEIR OVERALL REPRESENTATION OF
THE PATTERNS BEGINNING TUESDAY. 0Z MODEL BLEND IS USED BY HPC
THROUGH TUESDAY AND THEN A BLEND WITH THE 12Z ECMWF IS USED FOR
MIDWEEK. WILL USE THE LATEST EUROPEAN FOR THE TUES NIGHT/WED
FORECAST WHEN IT COMES IN.
HIGH TEMPERATURES WILL BE AROUND NORMAL FOR MUCH OF THE PERIOD.
LOWS WILL RISE BACK TO ABOVE NORMAL LEVELS WHICH HAVE BEEN COMMON
THIS WINTER SEASON.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
CURRENT BAND OF LIGHT RAIN ON RADAR IS NOT REDUCING CIGS/VSBYS AT
ALL TO CRITICAL LEVELS...SO THIS IS NOT OF CONCERN THROUGH 22Z.
THEREAFTER...SHOWERS/STORMS EXPECTED TO DEVELOP IN SOUTHERN INDIANA AND
SPREAD THROUGH MANY OF THE TAF SITES. INSTABILITY CONTINUES TO BE
EXTREMELY LIMITED THUS HAVE GONE CONSERVATIVE ON AMOUNT OF THUNDER
USED IN THE TERMINALS. CURRENTLY HAVE LEFT IT OUT BUT SEE THE BEST
POTENTIAL AT CVG/LUK/DAY BEFORE INSTABILITY WANES FURTHER TO THE
NORTH/EAST FOR THE CMH/LCK. VSBYS AND CIGS THOUGH SHOULD AT LEAST
BE MVFR DURING AND WILL LIKELY DIP BELOW TO IFR IN THE HEAVIEST
DOWNPOURS. PREFER TO SEE CONVECTIVE INITIATION FIRST BEFORE
INSERTING THIS IN THE TERMINALS AS THERE IS SOME QUESTION ON WHERE
THE MORE FOCUSED BATCH OF IFR VSBYS WILL BE IN FALLING RAIN AND/OR
THUNDER.
VERY TOUGH WIND FORECAST WITH SFC LOW TO PASS DIRECTLY OVERHEAD
SOME OF THE TAF SITES. HAVE PLAYED A SOLUTION WHICH TAKES SFC LOW
FROM DAY TO CMH SO TRIED TO INDICATE A PERIOD OF LGT/VARIABLE FLOW
AS THE SFC LOW GOES BY THIS EVENING. AT CVG/LUK...WAS QUICK TO
BRING IN THE STRONGER SWLY FLOW IMMEDIATELY AS THE LOW PASSES. ALL
SITES HAVE POTENTIAL FOR VERY STRONG GUSTS > 35 KTS LATER TONIGHT
INTO MUCH OF FRIDAY MORNING. IN THE COLD ADVECTION...EXPECT
WIDESPREAD BKN MVFR CIGS WITH THE STEEP LAPSE RATES...STRONG
WINDS...AND THE POTENTIAL FOR A FEW SHOWERS.
OUTLOOK...GUSTY WESTERLY WINDS WILL BE POSSIBLE ON FRIDAY. MVFR
CEILINGS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...BINAU
SHORT TERM...HICKMAN
LONG TERM...FRANKS
AVIATION...BINAU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1019 AM EST THU FEB 23 2012
.SYNOPSIS...
LOW PRESSURE WILL DEVELOP OVER THE MIDDLE MISSISSIPPI VALLEY
TODAY. THE LOW WILL DEEPEN TONIGHT AS IT MOVES NORTHEAST TOWARD THE
EASTERN GREAT LAKES. A COLD FRONT WILL SWEEP ACROSS THE AREA IN
THE WAKE OF THE LOW...BRINGING MUCH COLDER AIR TO THE OHIO VALLEY
ON FRIDAY. COLD AIR ALONG WITH SNOW SHOWERS CAN BE EXPECTED FOR
THE FIRST PART OF THE WEEKEND. HIGH PRESSURE WILL RETURN TO THE
OHIO VALLEY ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED FORECAST LARGELY KEEPS RAIN CHANCES AS-IS THROUGH LATE
AFTERNOON AND ONLY SERVES TO TIGHTEN THE TEMPERATURE GRADIENT
ACROSS THE FORECAST AREA TODAY. MONITORING FOR THE POTENTIAL FOR
SEVERE WEATHER VERY LATE THIS AFTERNOON AND THIS EVENING IN THE SOUTH.
WEAK IMPULSE THIS MORNING OVER NRN IL ALLOWING MID LEVEL FLOW TO
BACK AND INDUCE MODEST OVERRUNNING/ISENTROPIC LIFT /295K/. THIS IS
DRIVING A FAIRLY SUBSTANTIAL DECK OF MID-LEVEL CLOUDS AND BAND OF
LIGHT PRECIPITATION ACROSS CNTL IND WHERE THE LEADING EDGE HAS
BEEN WORKING TO OVERCOME A DRY SUB-CLOUD LAYER. CONTINUE TO THINK
THIS WILL BRING A BRIEF PERIOD OF LIGHT RAIN TO MAINLY AREAS NORTH
OF I-70 LATE THIS MORNING AND INTO THE MID AFTERNOON.
CLEARING NOW DEVELOPING OVER SRN IL IS OF INTEREST GIVEN THE
DYNAMIC SHORTWAVE DIGGING THROUGH NEB AND TOWARD THE OH VALLEY. IN
FACT...CONVECTIVE CLOUD ELEMENTS NOW SHOWING IN THIS AREA AS THIS
AREA DESTABILIZES RAPIDLY. THIS WAVE WILL INDUCE A DEEPENING SFC
LOW AND STRENGTHENING WARM FRONT ALONG THE OHIO RIVER TO OUR SW
THIS AFTERNOON...WITH A STRONG FLUX OF LOW LEVEL MOISTURE AND
CONVERGENCE INTO SRN INDIANA/NRN KY BY LATE THIS AFTERNOON. BULK OF
CONVECTION-ALLOWING /4KM/ MODELS INITIATE SHALLOW CONVECTION IN
THIS AREA AROUND 21Z...EXPANDING IT RAPIDLY EAST/NORTHEAST AS WARM
SECTOR PUSHES NORTH ATTENDANT TO DEEPENING CYCLONE. BIGGEST
CONCERN IS FOR SEVERE STORMS NEAR AND SOUTH OF OHIO RIVER WHERE
LOW LEVEL INHIBITION IS MINIMIZED /MORE SLY/SELY SFC TRAJECTORY
WITH MORE BUOYANT AIRMASS/. FORECAST RUC SOUNDINGS NORTH OF WARM
FRONT /MORE ELY TRAJECTORY/ HAVE TREMENDOUS SHEAR/LONG HODOGRAPHS
BUT SLIGHTLY INVERTED LOW LEVEL TEMP TRACE THAT WILL GREATLY
INHIBIT TORNADO THREAT ESPECIALLY GIVEN THE VERY MEAGER INSTBY.
OUR GREATEST CONCERN IS CURRENTLY NRN KENTUCKY INTO EXTREME SCNTL
OH...ESP AREAS SOUTH/WEST OF CVG OVER TOWARD AREAS SOUTHWEST OF
PMH. WITH EVERY TIER OF COUNTIES SOUTH...THE LOW LEVEL
THERMODYNAMICS ARE MORE FAVORABLE TO TAP VERY IMPRESSIVE SHEAR
WITH 0-1KM VALUES IN EXCESS OF 40KTS. WITH EVERY TIER OF COUNTIES
NORTH BECOMES A LESS FAVORABLE LOW LEVEL AIRMASS AND EVEN MORE
MEAGER /RELATIVE/ INSTABILITY. THIS WILL BE A RAPIDLY CHANGING
AIRMASS/THETA-E PROFILE THIS EVENING AND WILL NEED TO BE WATCHED
CLOSELY. IF STORM CLUSTER CAN BECOME ROOTED ALONG THE WARM
FRONT...COULD BECOME A VERY ACTIVE PERIOD BETWEEN 22Z-03Z.
AFTER THE LOW/STORM CLUSTER PASS TO THE NORTHEAST...A BIG PUSH OF
WIND THAT MAY REQUIRE AN ADVISORY DESPITE POOR CLIMATOLOGY TIME
PERIOD. STRONG COLD ADVECTION/ISALLOBARIC FORCING AND REMNANT LOW
LEVEL JET PUT MUCH OF THE CWA IN PRIME ZONE FOR A PERIOD WHERE
WINDS COULD GUST TO 45MPH OR HIGHER.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
SFC LOW AND ASSOCIATE S/WV WILL PIVOT NE ACRS NEW ENGLAND/SAINT
LAWRENCE RIVER VALLEY ON FRIDAY WHILE AN UPPER LEVEL TROF AND
EMBEDDED DISTURBANCES WITHIN THE FLOW BEGIN TO AFFECT THE REGION.
COLDER AIR WILL CONTINUE TO FILTER IN ON FRIDAY ALONG WITH
SCATTERED RAIN SHOWERS AND SNOW SHOWERS. PCPN SHOULD CHANGE TO ALL
SNOW BY FRIDAY NIGHT AS TEMPERATURES CONTINUE TO FALL. BY
SATURDAY...COLD UPR LVL TROF WILL BEGIN TO PIVOT NE. 850 MB COLD
POOL WILL BE AT ITS MAXIMUM RESULTING IN BELOW NORMAL TEMPERATURES
AND LINGERING SNOW SHOWERS. UPR LVL TROF WILL PUSH OFF THE
ATLANTIC SEABOARD SATURDAY NIGHT...ALLOWING SFC HIGH PRESSURE TO
BUILD INTO THE OHIO VALLEY. ON SUNDAY...SFC HIGH WILL MOVE EAST.
ALONG WITH MOSTLY SUNNY SKIES...TEMPERATURES WILL REBOUND IN THE
RETURN FLOW PATTERN ON THE BACK SIDE OF THE DEPARTING HIGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
A STRONG LOW WILL MOVE THROUGH THE UPPER MIDWEST TO THE NORTHERN
GREAT LAKES REGION SUNDAY AND MONDAY...TRAILING A COLD FRONT
THROUGH THE OHIO VALLEY. MODELS DIFFER ON THE TRACK AND STRENGTH
OF THE LOW AND ITS ASSOCIATED COLD FRONT. THIS DIFFERENCE WILL
RESULT IN A HIGHER UNCERTAINTY IN THE CHANCES OF RAIN AHEAD OF THE
FRONT ON MONDAY...AND WITH ITS PASSAGE MONDAY NIGHT.
HIGH PRESSURE AND A DRY PATTERN IS IN STORE FOR TUESDAY IN THE OHIO
VALLEY. MODELS QUICKLY DIVERGE IN THEIR OVERALL REPRESENTATION OF
THE PATTERNS BEGINNING TUESDAY. 0Z MODEL BLEND IS USED BY HPC
THROUGH TUESDAY AND THEN A BLEND WITH THE 12Z ECMWF IS USED FOR
MIDWEEK. WILL USE THE LATEST EUROPEAN FOR THE TUES NIGHT/WED
FORECAST WHEN IT COMES IN.
HIGH TEMPERATURES WILL BE AROUND NORMAL FOR MUCH OF THE PERIOD.
LOWS WILL RISE BACK TO ABOVE NORMAL LEVELS WHICH HAVE BEEN COMMON
THIS WINTER SEASON.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
PRIMARY CONCERN FOR THE TAFS IS CHANCES FOR RAIN (POSSIBLY WITH
THUNDER) AND STRONG WINDS AT VARIOUS POINTS THROUGH THE VALID
FORECAST PERIOD.
WINDS ARE LIGHT AND VARIABLE OVER THE REGION RIGHT NOW...BUT WILL
EVENTUALLY TURN SOUTHEASTERLY TO EASTERLY DURING THE MORNING. AN
INITIAL AREA OF RAIN WILL MOVE ACROSS THE TAF SITES BY EARLY
AFTERNOON...BUT WITH LITTLE IMPACT TO AVIATION CONDITIONS. HAVE
ONLY INCLUDED RAIN IN THE PREVAILING SECTION OF THE FORECAST FOR
THE NORTHERN TAF SITES.
THEREAFTER...LOW PRESSURE TRACKING ACROSS OHIO WILL INTRODUCE A
MORE SIGNIFICANT CHANCE OF RAINFALL...AND POSSIBLY THUNDERSTORMS.
THE BEST TIMING FOR THIS ACTIVITY WILL BE DURING THE EVENING
HOURS...AS IS DENOTED WITH A PERIOD OF -SHRA. MVFR CEILINGS ARE
EXPECTED TO ACCOMPANY THIS ACTIVITY FOR SURE FOR THE NORTHERN TAF
SITES. HEAVIER SHOWERS COULD ALSO BRING MVFR VISIBILITIES.
THUNDERSTORMS ARE ALSO POSSIBLE...WITH THE BEST CHANCE BEING AT
THE CINCINNATI TAF SITES. IF THUNDERSTORMS DEVELOP...IFR
CONDITIONS AND GUSTY WINDS WILL BE POSSIBLE.
OVERNIGHT...WINDS WILL SHIFT TO THE WEST AS THE FRONTAL BOUNDARY
PASSES BY. THIS WILL END THE TAF PERIOD WITH SOME VERY STRONG WIND
GUSTS (ABOVE 30 KNOTS).
OUTLOOK...GUSTY WESTERLY WINDS WILL BE POSSIBLE ON FRIDAY. MVFR
CEILINGS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...BINAU
SHORT TERM...HICKMAN
LONG TERM...FRANKS
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
124 AM EST THU FEB 23 2012
.SYNOPSIS...
A WEAK COLD FRONT CROSSES TONIGHT AND ANOTHER WARM FRONT THURSDAY. A
STRONG COLD FRONT CROSSES THURSDAY NIGHT. FALLING TEMPERATURES
FRIDAY. LIGHT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...
RAISED POPS TO LIKELY ACROSS THE MIDDLE PORTION OF THE AREA WITH S/W
TROF MOVING ACROSS THE OHIO VALLEY OVERNIGHT. ALSO...WARM FRONT
SETS UP OVER SOUTHERN PORTION OF AREA THU MORNING AND TAKES MUCH OF
THE DAY TO MOVE N. INCREASED POPS THU TO REFLECT SHRA/TSRA N OF THE
FRONT.
10PM UPDATE...
SHOULD GET A BREAK FROM THE SHOWERS...BUT IR SATELLITE IMAGERY
SHOWING THE NEXT WAVE EMBEDDED IN THE BROAD CYCLONIC FLOW ALOFT
NOW PUSHING THROUGH SOUTHERN ILLINOIS AND INDIANA. ARRIVAL TIME TO
THE TRI STATE AREA LOOKING TO BE 07Z OR SO BASED ON THE HRRR WHICH
HAS A HOLD OF THIS FEATURE. HAVE BUMPED UP THE POPS IN THIS TIME
FRAME TO REFLECT THIS VORT MAX MOVING THROUGH.
PREVIOUS DISCUSSION...
CURRENT RADAR SHOWS SOME RETURNS ACROSS THE COAL FIELDS IN
ASSOCIATION WITH AN UPPER LEVEL SHORTWAVE TROUGH AND WEAK SURFACE
BOUNDARY...HOWEVER DEW POINT DEPRESSIONS ARE STILL PRETTY LARGE AND
HAVE NOT HAD ANY REPORTS OR PRECIP HITTING THE GROUND YET IN OUR CWA.
AS THE COLUMN SATURATES...SHOWERS ARE POSSIBLE THIS EVENING ACROSS
THE COAL FIELDS...EXTENDING NE INTO THE MOUNTAINS OVERNIGHT. HAS
NOT BEEN MUCH LIGHTNING ACTIVITY WITH THIS SINCE EARLIER THIS
MORNING...BUT HAVE LEFT MENTION OF THUNDER THROUGH EARLY EVENING
ACROSS SOUTHERN COAL FIELDS. CONVECTIVE SHOWERS...EVEN WITHOUT
THUNDER...COULD STILL ENHANCE TODAYS GUSTY WINDS AND PRODUCE
LOCALIZED GUSTS UP OF 40 TO 50 MPH.
AS A WARM FRONT PASSES THROUGH ANOTHER ROUND OF WARM AIR
ADVECTION SETS IN TOMORROW...SO WILL SEE A MILD TO WARM DAY ACROSS
THE REGION. THE LOWLANDS SHOULD WARM INTO THE UPPER 50S AND
60S...WITH THE MOUNTAINS TOPPING OUT IN THE LOWER 50S. A STRONG
COLD FRONT WILL BE APPROACHING FROM THE WEST ON THURSDAY...SO
COULD SEE SOME SHOWERS MOVING INTO SE OHIO BY LATE AFTERNOON AHEAD
OF THE COLD FRONT. TIME OF DAY IS NOT REAL CONDUCIVE TO
THUNDER...BUT COULD GET A RUMBLE OR TWO BEFORE EARLY EVENING AND
LOSS OF DIURNAL HEATING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
COLD FRONT...FROM LOW PRESSURE THAT WILL MOVE ACROSS THE SOUTHERN
GREAT LAKES AND INTO THE ST. LAWRENCE RIVER VALLEY THURSDAY
NIGHT...WILL MOVE ACROSS THE CWA AND THROUGH THE REGION BY FRIDAY
MORNING. SHOWERS AND POSSIBLY A RUMBLE EARLY WILL MOVE THROUGH
WITH THE FRONT. MUCH COLDER AIR MOVES IN BEHIND THE FRONT ON
FRIDAY WITH 85H TEMPS DIPPING TO -8 TO -10 ON GOOD NORTHWEST FLOW.
SHOWERS WILL CONTINUE INTO SATURDAY AS UPPER TROUGH AND UPPER
LEVEL DISTURBANCES MOVE THROUGH THE REGION. AIR WILL BE COLD
ENOUGH THAT ANY SHOWERS WILL QUICKLY MIX OR CHANGE OVER TO LIGHT
SNOW AND COULD SEE SOME LIGHT ACCUMULATIONS ACROSS THE HIGHER
TERRAIN...ESPECIALLY IN THE UPSLOPE AREAS OF THE NORTHERN MOUNTAINS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PERIOD GENERALLY DEFINED BY EXITING POSITIVELY TILTED SHORTWAVE
TROUGH TO THE NORTH OF AREA SAT EVENING WITH RIDGING BUILDING INTO
REGION FOR SUNDAY...FOLLOWED BY UPPER LEVEL CUTOFF LOW TO NORTHWEST
WITH ASSOCIATED SOUTHWEST FLOW ALOFT AHEAD OF IT ACROSS EASTERN
CONUS FOR MON-WED TIME FRAME.
SAT NIGHT LARGE SCALE SUBSIDENCE OVERSPREADS FORECAST AREA AS
AFOREMENTIONED SHORTWAVE TROUGH AXIS PROGRESSES ACROSS REGION. DEPTH
OF LOW LEVEL MOISTURE TRAPPED WITH SFC FLOW OFF GREAT LAKES SHOULD
BE SUFFICIENTLY DEEP TO KEEP SOME -SN GOING IN PREFERRED UPSLOPE
LOCATIONS. LIGHT SNOW WILL COME TO AN END BY EARLY SUNDAY MORNING
WITH RAPIDLY CLEARING SKIES AND SEASONAL AFTERNOON TEMPS AS UPPER
LEVEL RIDGING BUILDS INTO THE AREA. FLOW ALOFT RAPIDLY TURNS
SOUTHWEST FROM MON-WED HOWEVER AS UPPER LEVEL LOW PROGRESSES ACROSS
THE NORTH CENTRAL CONUS. THIS FEATURE ALONG WITH ASSOCIATED COLD
FRONT/MOISTURE FIELDS ARE WHERE LONG RANGE BEGIN TO DIVERGE. MUCH OF
THE LONG RANGE GUIDANCE LEANS TOWARDS A SLOWER SOLUTION...WHILE THE
GFS IS MUCH MORE PROGRESSIVE. GEFS LOOSELY SUPPORTS THE SLOWER
SOLUTION AS WELL AND THUS HAVE LEANED THE FORECAST IN THIS
DIRECTION.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
MAINLY VFR CONDITIONS TO START OUT DESPITE SHRA/TSRA MOVING ACROSS
SOUTHERN PORTIONS OF THE AREA AND IN THE MOUNTAINS EARLIER IN THE
NT. PATCHY MVFR FOG IS POSSIBLE ANY TIME OVERNIGHT IN THESE
AREAS...AND MVFR STRATOCU MAY FORM IN THE MOUNTAINS.
A WARM FRONT WILL TRIGGER AREAS OF SHOWERS AND THUNDERSTORMS AS IT
SETS UP ACROSS E KY AND SRN WV THU MORNING...AND THEN MOVE N ACROSS
THE AREA DURING THE DAY. THE FIRST SUCH BATCH MOVING THROUGH THE
MIDDLE OHIO VALLEY TO START THE PERIOD MOVES E ACROSS CENTRAL WV
OVERNIGHT. THIS COULD BRING MVFR CONDITIONS. A SECOND BATCH WILL
LIKELY COME THROUGH THE MIDDLE OHIO VALLEY THU MORNING BUT THIS
BATCH IS LIKELY TO MOVE NE...AFFECTING NORTHERN WV...THU AFTERNOON.
FINALLY...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS
A COLD FRONT APPROACHES THE AREA FROM THE W. ANY OF THE SHOWERS AND
THUNDERSTORMS CAN BRING MVFR OR WORSE CONDITIONS...ALONG WITH STRONG
WIND GUSTS.
LIGHT SW SFC FLOW INTO THU MORNING WILL TURN SE N OF THE WARM FRONT
THU AND STRENGTHEN FROM THE SW S OF THE FRONT. WINDS WILL SWITCH TO
SW AND STRENGTHEN LATER THU FARTHER N...AS THE WARM FRONT MOVES N.
MODERATE FLOW ALOFT OVERNIGHT WILL BECOME STRONG S THU. STRONG SW
FLOW SFC AND ALOFT SHOULD DOMINATE EVERYWHERE BY 06Z FRI.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM.
ALTERNATE SCENARIOS: THIS IS A PATTERN MORE AKIN TO SPRING AND EARLY
SUMMER THAN WINTER...WITH A HIGH DEGREE OF UNCERTAINTY AS TO WHERE
AREAS OF SHOWERS AND THUNDERSTORMS WILL BE...ESPECIALLY BEYOND 6
HRS. EVEN THE WIND PATTERN IS A BIT COMPLEX AS A WARM FRONT
DEVELOPS OVER AND THEN MOVES N ACROSS THE AREA...AND THUNDERSTORMS
PRODUCE STRONG WIND GUSTS FROM VARIOUS DIRECTIONS BUT MOST LIKELY
MORE W THAN THE GENERAL FLOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/23/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M H M H H L L L H M M
HTS CONSISTENCY H H H H H H M M L H H H
BKW CONSISTENCY M M H M M L M M M H M H
EKN CONSISTENCY M M M M M M M H H M M M
PKB CONSISTENCY H H M H M M H M M M M H
CKB CONSISTENCY M H H M H H H H M M M H
AFTER 06Z FRIDAY...
IFR POSSIBLE IN LINGERING RAIN SHOWERS OR THUNDERSTORMS AND LOW
CLOUDS LATE THU NT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/ARJ/MZ/GG
NEAR TERM...ARJ/TRM/MZ/26
SHORT TERM...JS
LONG TERM...GG
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
316 AM EST THU FEB 23 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER THE AREA TODAY. A COLD FRONT IS
EXPECTED TO SWEEP ACROSS THE CAROLINAS EARLY FRIDAY. HIGH PRESSURE
WILL THEN RETURN OVER THE WEEKEND AND LINGER INTO EARLY NEXT WEEK.
ANOTHER COLD FRONT WILL APPROACH THE REGION FROM THE WEST NEXT
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A LINE OF CONVECTION SHOULD MOVE TO THE EAST OF THE FCST AREA BY
08Z...THEREAFTER WE WILL ONLY HAVE TO DEAL WITH A FEW STRAGGLERS
DEVELOPING IN A WEAKLY FORCED ENVIRONMENT AHEAD OF A TRAILING SHORT
WAVE. THESE SCATTERED SHOWERS SHOULD ALSO WORK THEIR WAY EAST AND BE
OUT OF THE AREA BY SUNRISE. IN THE MEAN TIME...PATCHES OF FOG AND
LOW STRATUS WILL DEVELOP IN THE RAIN COOLED AIR THROUGH DAYBREAK.
TEMPS SHOULD REMAIN MILD.
FOR TODAY...THE MAIN STORY WILL BE THE WARM TEMPS. THE NEARLY ZONAL
FLOW ALOFT WILL BUCKLE WITH HEIGHTS RISING DURING THE DAY AS A RIDGE
BUILDS OFF THE E COAST. NOT ONLY WILL WE GET A HEAD START WITH THE
MILD OVERNIGHT LOWS...BUT WARM ADVECTION WILL CONTINUE THROUGH THE
DAY WITH SW WINDS AT 850MB. HIGH TEMPS WERE NUDGED TOWARD THE BIAS
CORRECTED GUIDANCE WHICH ACTUALLY RESULTED IN A CUT OF A DEGREE OR
TWO OFF THE PREVIOUS FCST...BUT IT SHOULD STILL BE MUCH ABOVE NORMAL
AT ANY RATE. FORCING WILL BE MINIMAL AS WE WILL BE IN BETWEEN UPPER
SYSTEMS...SO EXPECT A DRY DAY.
FOR TONIGHT...THE NEXT UPPER SYSTEM WILL MOVE EASTWARD OVER THE
MIDWEST...WHICH WILL PUSH A COLD FRONT TOWARD THE FCST AREA AFTER
MIDNIGHT. THE FRONT IS EXPECTED TO REACH THE MTNS BY DAYBREAK FRIDAY
WITH A WEAKENING BAND OF CONVECTIVE PRECIP. WILL ALLOW THE PRECIP
CHANCES TO CLIMB TO THE LIKELY RANGE ON THE TN BORDER IN THE LATE
EVENING...WITH THE THINKING THAT CONVECTION THAT DEVELOPS EARLIER IN
THE EVENING OVER TN WILL REACH WRN NC BEFORE FALLING APART. E OF THE
MTNS...THE PRECIP CHANCES WILL BE HELD IN CHECK BY DOWNSLOPE...SO
THE POP WAS LIMITED TO CHANCE OVER THE FOOTHILLS AND WRN UPSTATE...
AND SLIGHT CHANCE OVER THE WRN PIEDMONT. MIN TEMPS WILL ONCE AGAIN
BE RELATIVELY MILD FOR THIS TIME OF YEAR.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM THURSDAY...MODEL DIFFERENCES WITH RESPECT TO THE TIMING
OF THE EASTWARD PROGRESSION OF FRONTAL ZONE PCPN ON FRIDAY CONTINUE
WITH THE 00 UTC ECMWF REMAINING THE SLOW SOLUTION VERSUS BOTH THE
OP NAM/GFS. POPS WILL CONTINUE TO BE ORIENTED CLOSE TO THE LATEST
SREF...WITH ANY LINGERING/CONTINUED DEEP CONVECTION BECOMING LIMITED
TO JUST THE PIEDMONT BY AFTERNOON. BASED ON THE LIKELIHOOD THAT AS
PRIMARY LLJ/RICHER BLYR MOISTURE TRANSLATES TO THE EASTERN
CAROLINAS AS THE DAY WEARS ON...CHANCES FOR TSTMS TO PRODUCE
DAMAGING WIND GUSTS WILL BE BETTER EAST OF THE CWFA. AS LONG AS
INSOLATION IS NOT LIMITED A GREAT DEAL FROM LINGERING DEEPER
CONVECTION...THE PIEDMONT COULD SQUEAK OUT ONE MORE 70 DEG F DAY.
SAVE FOR THE POSSIBILITY OF NW NC SNOW SHOWERS...DEEP LAYERED DRYING
WILL OVERSPREAD THE REGION FRIDAY NIGHT...AND MIN TEMPS SATURDAY
MORNING COULD BE MORE THAN 20 DEG F COLDER THAN FRIDAY MORNING.
WITHIN THE LINGERING CYCLONIC FLOW ALOFT...DEEP LAYER DRY AIR
CONTINUES THRU SATURDAY AS LLVL RIDGING BUILDS EASTWARD. CHILLIER
AIR ACRS THE MTNS WILL BE SLOWER TO DISPLACE...BUT FTHL/PIEDMONT
MAX TEMPS SHOULD BE CLOSE TO CLIMO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 200 AM THURSDAY...THE MEDIUM RANGE MODELS ARE IN FAIRLY GOOD
AGREEMENT WITH BROAD SURFACE HIGH OVER THE EASTERN CONUS WILL BRING
MOSTLY DRY WEATHER AND SEASONABLY COOL TEMPERATURES TO MUCH OF THE
REGION ON SUNDAY. AS THE HIGH MOVES OUT INTO THE ATLANTIC MONDAY...
AN UPPER LVL DISTURBANCE OVER THE GULF WILL LIFT NORTH ACROSS OUR
AREA. THE ECMWF IS MUCH WETTER THAN THE GFS BRINGING PRECIP AMOUNTS
UP TO 0.25 INCHES INTO MUCH OF THE REGION. THE GFS HAS LIGHT PRECIP
DEVELOPING OVER MAINLY SOUTHERN HALF OF OUR FORECAST AREA IN
RESPONSE TO A WEAK HIGH PRESSURE DOMINATING OVER THE NORTH. I USED
MODEL BLEND KEEPING AT LEAST SLIGHT CHANCE POPS IN THE GRIDS MONDAY.
AN UPPER RIDGE WILL BUILD OVER THE REGION FOR MOSTLY DRY WEATHER AND
MILDER TEMPERATURES ON TUESDAY. A STRONG COLD FRONT WILL
APPROACH THE CAROLINAS FROM THE WEST RESULTING IN UNSETTLED WEATHER
ACROSS OUR REGION ON WEDNESDAY. MODELS SHOW DECENT CAPE VALUES WILL
BE OVER THE SOUTHERN PORTIONS OF OUR CWA DURING THE PASSAGE OF THE
SYSTEM. HENCE...A CHANCE OF THUNDERSTORMS WAS MENTIONED MAINLY SOUTH
OF THE REGION ON WEDNESDAY. TEMPERATURES WILL STAY NEAR OR A LITTLE
ABOVE NORMALS THROUGH THE PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...IMMEDIATE CONCERN IS LINE OF CONVECTION MOVG
ACROSS THE WESTERN CAROLINAS THIS EVENING...BUT THAT SHOULD BE GONE
BY 07Z WITH ONLY A FEW SHOWERS LEFT OVER THE HIGHER TERRAIN THROUGH
THE PRE-DAWN HOURS. WITH THAT OUT OF THE WAY...THE MAIN CONCERN
BECOMES THE MODEL FCST OF WIDESPREAD IFR STRATUS THROUGH SUNRISE.
STILL NOT CONVINCED THE LAMP AND NAM ARE ON THE RIGHT TRACK WITH
THIS. SATELLITE IMAGERY SHOWS PATCHES OF LOWER CLOUDS OVER N GA AND
NE AL IN THE WAKE OF THE CONVECTION...BUT THE WORST OF IT IS BARELY
MVFR. THINK THE RUC MIGHT HAVE THE BETTER HANDLE ON PATCHY MVFR
CEILINGS AND WILL STEER THE TAFS IN THAT DIRECTION. THE CLOUDS WILL
SCATTER OUT DURING THE 13Z TO 15Z TIME FRAME...AFTER WHICH THE
BALANCE OF THE DAY WILL BE VFR WITH A SW WIND. THE NEXT UPPER SYSTEM
SHOULD NOT ARRIVE UNTIL AFTER THE END OF THE TAF PERIOD.
OUTLOOK...LOW PRESSURE WILL DEVELOP OVER THE DEEP SOUTH THU NIGHT
AND FRI. WIDESPREAD LOW CIGS AND PCPN ARE EXPECTED AS THE LOW
DEVELOPS. DRIER AND COLDER WEATHER WILL FOLLOW FOR THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...PM
SHORT TERM...CSH
LONG TERM...JOH
AVIATION...PM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1245 AM EST THU FEB 23 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY. A
STRONG COLD FRONT IS EXPECTED TO MOVE OVER THE CAROLINAS EARLY
FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE WEEKEND AND LINGER
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A LINE OF CONVECTION WILL CONTINUE TO WORK ITS WAY ACROSS THE
EASTERN ZONES DURING THE EARLY MORNING HOURS...AND SHOULD BE EAST OF
THE FCST AREA BY 07Z. ONLY SCATTERED SHRA TO DEAL WITH...MAINLY OVER
THE HIGHER TERRAIN...FOR THE PREDAWN HOURS...AND THAT SHOULD END
BEFORE SUNRISE. HAVE RAISED THE PRECIP CHANCES ACCORDINGLY OVER THE
EAST AND LOWERED THEM OUT WEST TO MATCH RADAR TRENDS.
PREVIOUS DISCUSSION...STRONGER SHORT WAVE MOVES THRU THE BOTTOM OF A
BROAD LONG WAVE TROF AND ACROSS THE AREA THIS EVENING. THIS SHOULD
HELP ADDITIONAL CONVECTION DEVELOP THIS EVENING AND MOVE IT ACROSS
THE CWFA. ACTIVITY SHUD BEGIN OVER THE NC MTNS AND NE GA AND MOVE
EAST ACROSS THE CWFA. DEW POINTS SHUD CONTINUE TO INCREASE AHEAD OF
THE WAVE IN THE STRONG SWLY FLOW. THIS WILL LEAD TO WEAK INSTABILITY
ACROSS THE AREA THIS EVENING AS THE WAVE MOVES THRU. SHEAR STILL
EXPECTED TO BE QUITE STRONG AS A LOW LEVEL JET DEVELOPS. LARGE
HELICITY VALUES WITH STRONG TURNING PROFILE ALSO EXPECTED. STILL
APPEARS TO BE A THREAT OF SEVERE STORMS PRODUCING DAMAGING WINDS OR
EVEN A TORNADO IF THE WEAK INSTABILITY CAN BE REALIZED. MULTICELLS
OR EVEN MINI-SUPERCELLS WILL BE POSSIBLE. THE CONVECTION SHUD SWEEP
EAST OF THE AREA AFTER MIDNIGHT WITH SOME LINGERING MTN SHRA ENDING
BY DAYBREAK. EXPECT AREAS OF FOG AND LOW CLOUDS TO DEVELOP AGAIN
TOWARD MORNING IN THE LINGERING LOW LEVEL MOISTURE. LOWS WILL BE AS
MUCH AS 15 DEGREES ABOVE NORMAL.
CLEARING SKIES AND VERY WARM CONDITIONS EXPECTED THU AS HEIGHTS RISE
IN DEVELOPING ZONAL FLOW. EXPECT THE LOW CLOUDS AND FOG TO DISSIPATE
A LITTLE MORE QUICKLY THU MORNING AS FLOW WILL BE A LITTLE MORE WLY
AND DRIER AIR MOVES IN. SHUD BE ANOTHER BREEZY DAY BUT WIND GUSTS
NOT QUITE AS STRONG. HIGHS WILL BE 15 TO 20 DEGREES ABOVE NORMAL IN
THE WLY FLOW AND RISING THICKNESSES.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AS OF 200 PM WEDNESDAY...A WEAKLY FORCED FRONTAL BOUNDARY IS
FORECAST TO MOVE ACROSS THE MOUNTAINS AND INTO THE PIEDMONT BY 12Z
FRI WELL AHEAD OF THE MAIN UPPER TROUGH TO ITS WEST. THE QUESTION IS
WHAT THE COVERAGE OF CONVECTION WILL BE THU NIGHT ALONG AND AHEAD OF
THE FRONTAL BOUNDARY? CURRENT INDICATIONS FROM MODEL GUIDANCE IS THAT
A BROKEN LINE OF CONVECTION WILL REACH THE MOUNTAINS SOMETIME AFTER
MIDNIGHT...BUT TEND TO DECREASE IN COVERAGE AS IT MOVES OFF THE
MOUNTAINS EARLY FRIDAY MORNING DUE TO DEEP SW-W WIND FLOW WITH
LITTLE APPARENT BACKING OF THE WIND FIELD IN THE LOWER LEVELS. WIND
SPEEDS/SHEAR WILL BE IMPRESSIVE THU NIGHT WITH 850MB WINDS 50+ KTS.
HELICITY VALUES WILL ALSO BE QUITE HIGH. HOWEVER...LOOKING AT THE
MODEL SOUNDINGS...A MID LEVEL CAPPING INVERSION IS APPARENT. THE
BOTTOM LINE IS THAT IT LOOKS LIKE IT WILL BE DIFFICULT TO GET DEEP
CONVECTION TO DEVELOP OVER A LARGE AREA THU NIGHT...SO WILL SHOW
LIKELY TYPE COVERAGE ENTERING THE MOUNTAINS...BUT DIMINISHING INTO
THE SCATTERED RANGE AS THE FRONT MOVES OFF THE MOUNTAINS. THE SEVERE
THREAT IS CERTAINLY NON ZER0...BUT IT APPEARS ANY SEVERE CONVECTION
SHOULD BE ISOLATED.
THE FORECAST DOES NOT GET ANY EASIER FOR FRI AS THE FRONTAL BOUNDARY
WILL BE SLOW TO EXIT THE AREA AS IT AWAITS A PUSH FROM THE UPPER
TROUGH APPROACHING FROM THE WEST. THE 12Z MODEL SUITE CONTINUES TO VARY
CONSIDERABLY IN REGARD TO HOW FAST THE FRONT WILL MOVE AWAY FROM THE
AREA AND ALSO HOW MUCH PRECIP WILL FALL ALONG THE BOUNDARY. THE
NAM/ECM/GEM ARE SLOWER/WETTER THAN THE FASTER/DRIER GFS. THE SREF
AGAIN APPEARS TO BE A GOOD COMPROMISE WHICH WILL KEEP POPS OVER THE
AREA OUTSIDE OF MOUNTAINS WITH THE HIGHEST POPS OVER SOUTHERN AREAS.
THE FRONT SHOULD FINALLY PUSH TO THE EAST OF THE AREA FRI NIGHT. THE
UPPER TROUGH AXIS IS FORECAST TO ROTATE THROUGH LATE FRI NIGHT INTO
SAT. LOOKS LIKE AT LEAST SOME SCATTERED SNOW SHOWERS WILL BE THE
RESULT IN THE TN BORDER COUNTIES...ESPECIALLY IN THE NORTHERN
MOUNTAINS. OTHERWISE..,.SAT LOOKS TO BE GENERALLY SUNNY ELSEWHERE WITH
TEMPS ABOUT CATEGORY BENEATH SEASONAL LEVELS EVEN WITH DOWNSLOPE
FLOW. USED A MOS BLEND FOR TEMPS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WEDNESDAY...THE FIRST PORTION OF THE MEDIUM RANGE LOOKS
RATHER STRAIGHT FORWARD AS ALL GUIDANCE SOURCES AGREE THAT SURFACE
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATEHR REGIME ALL OF
SUNDAY AND MOST IF NOT ALL OF THE DAY ON MONDAY. HOWEVER...
DISCREPANCIES IN THE MODEL GUIDANCE QUICKLY DEVELOP BY LATE MON AS
MODELS BECOME OUT OF PHASE WITH UPPER FEATURES. ECM/GEM ARE MUCH
QUICKER THAN THE GFS WITH THE NEXT UPPER TROUGH AND SUBSEQUENT GULF
MOISTURE RETURN LATE MONDAY INTO MONDAY NIGHT. HPC USED A ECM
ENSEMBLE MEAN FOR THE TUE/WED TIME PERIOD WHICH SUPPORTS AN INITIAL
FRONTAL PASSAGE EARLY TUE...WITH A WAVE DEVELOPING ON THE FRONT AND
THEN MOVING AWAY FROM THE AREA ON WED. HENCE...THE FORECAST WILL BE
DRY SUN AND MON MOST AREAS....WITH UNSETTLED WEATHER RETURNING MON
NIGHT...FEATURING CHANCES OF RAIN INTO EARLY WED. DRYER AIR/CLEARING IS
SHOWN OVERSPREADING THE AREA BY LATE WED. STAYED CLOSE TO HPC
GUIDANCE FIELDS WHICH HAS MAX TEMPS NEAR OR A LITTLE BELOW
AVERAGE.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...IMMEDIATE CONCERN IS LINE OF CONVECTION MOVG
ACROSS THE WESTERN CAROLINAS THIS EVENING...BUT THAT SHOULD BE GONE
BY 07Z WITH ONLY A FEW SHOWERS LEFT OVER THE HIGHER TERRAIN THROUGH
THE PRE-DAWN HOURS. WITH THAT OUT OF THE WAY...THE MAIN CONCERN
BECOMES THE MODEL FCST OF WIDESPREAD IFR STRATUS THROUGH SUNRISE.
STILL NOT CONVINCED THE LAMP AND NAM ARE ON THE RIGHT TRACK WITH
THIS. SATELLITE IMAGERY SHOWS PATCHES OF LOWER CLOUDS OVER N GA AND
NE AL IN THE WAKE OF THE CONVECTION...BUT THE WORST OF IT IS BARELY
MVFR. THINK THE RUC MIGHT HAVE THE BETTER HANDLE ON PATCHY MVFR
CEILINGS AND WILL STEER THE TAFS IN THAT DIRECTION. THE CLOUDS WILL
SCATTER OUT DURING THE 13Z TO 15Z TIME FRAME...AFTER WHICH THE
BALANCE OF THE DAY WILL BE VFR WITH A SW WIND. THE NEXT UPPER SYSTEM
SHOULD NOT ARRIVE UNTIL AFTER THE END OF THE TAF PERIOD.
OUTLOOK...LOW PRESSURE WILL DEVELOP OVER THE DEEP SOUTH THU NIGHT
AND FRI. WIDESPREAD LOW CIGS AND PCPN ARE EXPECTED AS THE LOW
DEVELOPS. DRIER AND COLDER WEATHER WILL FOLLOW FOR THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...PM/RB/RWH
SHORT TERM...LG
LONG TERM...LG
AVIATION...PM
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
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.
&&
.AVIATION...00Z TAFS UPDATE
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 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.
&&
.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...HELGESON
LONG TERM....WFO UNR
AVIATION...HELGESON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
848 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.
&&
.AVIATION...00Z TAFS UPDATE
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. 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.
&&
.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...HELGESON
LONG TERM....WFO UNR
AVIATION...HELGESON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
423 PM MST FRI FEB 24 2012
.AVIATION...00Z TAFS
LEFTOVER SNOW SHOWERS WILL END ACROSS THE AREA EARLY THIS
EVENING...IFR VSBYS ARE EXPECTED UNDER THE -SHSN. OTHERWISE...VFR
CONDITIONS ARE EXPECTED OVERNIGHT INTO SATURDAY. GUSTY SOUTHWEST
WINDS WILL DEVELOP ACROSS NORTHEAST WY AND THE BLACK HILLS LATE.
&&
.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
NWS CORPUS CHRISTI TX
1121 PM CST WED FEB 22 2012
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...CONDITIONS ARE DETERIORATING ACROSS THE EASTERN
PORTIONS OF THE AREA...ESPECIALLY CLOSER TO THE COAST WHERE SEA
FOG IS ADVECTING INLAND. IFR/LIFR CONDITIONS ARE EXPECTED TO
PREVAIL THROUGH MUCH OF THE OVERNIGHT HOURS WITH IMPROVING
CONDITIONS BY MID MORNING ON THURSDAY. THERE IS THE POTENTIAL FOR
FOG THU NIGHT CLOSER TO 06Z WHICH IS THE TAIL END OF THE TAF
PERIOD THEREFORE WILL NOT MENTION IN TAF AT THIS TIME. BEYOND THE
TAF PERIOD...A STRONG COLD FRONT IS EXPECTED TO MOVE THROUGH S TX
BTWN 06Z AND 12Z FRI MORNING. AREAS TO THE WEST ACROSS THE RIO
GRANDE PLAINS ARE EXPECTED TO REMAIN VFR THROUGH THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 653 PM CST WED FEB 22 2012/
DISCUSSION...SEE MARINE SECTION BELOW.
MARINE...NAM SHOWS LOW VISIBILITIES MOVING INTO THE NORTHERN BAYS
THIS EVENING AS DOES THE RUC TO A LESSER EXTENT. AM LESS CONFIDENT
THAT SEA FOG WILL ADVECT INTO THE BAYS SOUTH OF PORT
ARANSAS...HOWEVER FARTHER S IN PORT ISABEL...VSBYS ARE 1/4SM.
THEREFORE HAVE DECIDED TO EXPAND THE MARINE DENSE FOG ADVISORY
INTO THE BAYS...INCLUDING SOUTH OF PORT ARANSAS...AND EXTEND
TIMING UNTIL 15Z. VISIBILITIES MAY VARY AT TIMES BUT FEEL VSBY
WILL BE 1NM OR LESS A MAJORITY OF THE TIME TONIGHT/EARLY THU
MORNING...AT LEAST ACROSS THE COASTAL WATERS AND PORT ARANSAS
NORTHWARD.
PREV DISCUSSION... /ISSUED 341 PM CST WED FEB 22 2012/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...FOR POTENTIAL
REMAINS A CHALLENGE THROUGH THE FORECAST PERIOD. HAVE SEEN MARINE
FOG JUST OFFSHORE THE COAST ALL DAY...AND AS LIGHT WINDS SHIFT
BACK A BIT FROM SOUTHWEST TO SOUTH TONIGHT...MAY SEE SOME OF THAT
SEA FOG PUSH INLAND...PRIMARILY NORTH OF CORPUS CHRISTI BAY. IF
WINDS WERE TO TURN EAST OF SOUTH...AS THE NAM INDICATES GOT COULD
PUSH INLAND AT CORPUS CHRISTI AS WELL. RADIATION FOG COULD ALSO BE
AN ISSUE IN THE EAST...BUT THINK THAT THE SOUTHWEST WINDS WE/VE
HAD TODAY SHOULD HELP TO KEEP THINGS FROM GOING DENSE IN MOST
AREAS.
WITH HIGH TEMPERATURES TODAY INTO THE 80S...AND IN SOME
AREAS...MIDDLE 80S...DONT SEE A REASON TO EXPECT COOLER NUMBERS
TOMORROW. WIND PATTERN LOOKS QUITE SIMILAR TOMORROW TO WHAT WE SAW
TODAY AND EXPECT MAINLY HIGH CLOUDS ONCE ANY FOG BURNS OFF. HAVE
GONE A FEW DEGREES WARMER THAN PREVIOUS FORECAST WITH SOME
LOCATIONS IN THE SOUTHWEST PART OF THE FORECAST AREA TOUCHING 90
DEGREES. THIS MAY EVEN STILL BE A LITTLE CONSERVATIVE AS NAM/GFS
GUIDANCE FOR COTULLA/LAREDO ABOVE 90...SO WOULD NOT BE SURPRISED TO
SEE SOME TEMPS IN THE LOWER 90S FAR WEST.
NEXT CHALLENGE BECOMES TIMING OF THE COLD FRONT. ECMWF AND
CANADIAN MODEL STILL LAGGING BACK A BIT WITH FRONT TIMING. GFS/NAM
SHOW FRONT THROUGH THE ENTIRE FORECAST AREA BY 12Z FRIDAY...WHILE
EC AND CANADIAN BISECT THE FORECAST AREA AT 12Z. HAVE GONE WITH
THE QUICKER SOLUTION FOR TIMING. WITH A MODERATE WIND INCREASE
IMMEDIATELY BEHIND THE FRONT.
MARINE...HAVE EXTENDED DENSE FOG ADVISORY THROUGH THE NIGHT.
WITH SEA SURFACE TEMPERATURES IN THE LOW TO MID 60S...AND
DEWPOINTS IN THE MID TO UPPER 60S...AND THE WIND PATTERN NOT
CHANGING SIGNIFICANTLY SEE NO REASON THIS FOG WILL MOVE OUT OR
DISSIPATE. BAYS AREAS FROM PORT ARANSAS NORTHWARD MAY SEE THE FOG
DRIFT BACK IN TONIGHT AS WE LOSE THE SOUTHWEST WIND COMPONENT OVER
LAND THAT HAS HELPED TO PUSH IT OUT TODAY. AN ADVISORY MAY BE
NEEDED FOR THE BAYS THIS EVENING OR TONIGHT. SOUTHERN BAYS ARE A
CHALLENGE AS SOME MODELS INDICATE A SOUTHEASTERLY WIND DEVELOPING
WHICH WOULD BRING THE FOG BACK INTO THESE BAYS AS WELL...FOR NOW
STICKING WITH MORE OF A SOUTHERLY WIND AND THE BAYS SOUTH OF PORT
ARANSAS STAYING OUT OF THE DENSE FOG.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...AFTER SEVERAL DAYS OF NOT
CATCHING ON TO THE POSSIBILITY OF THE UPPER LOW BEING MUCH SLOWER
TO MOVE OUT OF NORTHERN MEXICO...THIS FORECASTER ALONG WITH MOST
OF THE MODELS HAVE COME AROUND TOWARD THE SLOWER GFS SOLUTION. THE
UPPER LOW IS WELL DETACHED FROM THE MAIN STREAM AND THE STRONG UPPER
TROUGH MOVING INTO THE CENTRAL PLAINS FRIDAY MORNING PASSES BY WELL
TO THE NORTH. EVEN 12Z ECMWF IS IN LINE WITH THE GFS SHOWING THE
WEAKENING LOW MOVING ACROSS THE AREA BY 12Z SATURDAY. THE MODELS
ARE REASONABLY SIMILAR WITH THE TIMING OF THE COLD FRONT INTO THE
REGION EARLY FRIDAY MORNING. ADEQUATE MOISTURE AHEAD OF THE FRONT
AND APPROACH OF THE UPPER LEVEL JET STREAK SHOULD KEEP A THREAT FOR
SHOWERS MAINLY OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA INTO
THE GULF WATERS FRIDAY INTO FRIDAY NIGHT. BUT MOST OF THIS MOISTURE
WILL BE ELEVATED AND SHOULD SEE SOME DRYING IN THE BOUNDARY LAYER
BY FRIDAY AFTERNOON. WITH VERY STRONG NORTH-NORTHEAST WINDS AND
RH VALUES FALLING TO 30-35 PERCENT IN THE AFTERNOON...WILL KEEP
THE FIRE WEATHER WATCH GOING FOR THE COASTAL COUNTIES. BUT THE
CONFIDENCE IS NOT REAL HIGH AS CLOUD COVER SHOULD PERSIST AND ANY
LIGHT PRECIPITATION COULD KEEP RH VALUES ELEVATED ABOVE RED FLAG
CRITERIA. THEREFORE...STILL A WATCH. CLOUDS LINGERING OVER THE AREA
WILL KEEP MINIMUMS A BIT HIGHER FOR SATURDAY MORNING BUT COOLER
FOR MAX TEMPS. STILL LEANING TOWARD THE ECMWF/CAN/UKMET HANDLING OF
UPPER PATTERN FOR EARLY NEXT WEEK AS GFS LOOKS TOO PROGRESSIVE WITH
THE UPPER TROUGH MOVING INTO THE WESTERN UNITED STATES OVER THE
WEEKEND. ONSHORE FLOW WILL STEADILY INCREASE SUNDAY THROUGH MONDAY
WITH MOSTLY CLOUDY SKIES PREVALENT. A SHORT WAVE TROUGH LIFTS INTO
THE UPPER MIDWEST BY MONDAY MORNING THAT SHOULD SEND A WEAK FRONTAL
BOUNDARY INTO NORTH TEXAS MONDAY BUT STALL NORTH OF THE AREA. A
POSITIVE TILT UPPER TROUGH WILL MOVE THROUGH THE ROCKIES BY TUESDAY
MORNING WITH A FRONT MOVING INTO THE AREA TUESDAY NIGHT. LOW LEVEL
WARM AIR ADVECTION AHEAD OF THE FRONT SHOULD ALLOW FOR ISOLATED
STREAMER SHOWERS OVER MOST OF THE AREA MONDAY NIGHT THROUGH
WEDNESDAY.
89/TMT
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 66 83 62 64 45 / 10 10 30 30 30
VICTORIA 63 83 56 63 44 / 10 10 30 20 20
LAREDO 67 90 62 65 45 / 0 10 20 30 30
ALICE 65 86 62 64 46 / 10 10 20 30 30
ROCKPORT 64 80 60 63 48 / 10 10 30 30 30
COTULLA 60 87 55 64 42 / 0 10 20 20 20
KINGSVILLE 65 85 62 64 47 / 10 10 30 30 30
NAVY CORPUS 66 82 62 63 51 / 10 10 30 30 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY AFTERNOON
FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...
NUECES...REFUGIO...SAN PATRICIO.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR THE FOLLOWING
ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...
BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR...
COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...
COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
OUT 20 NM...WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20
TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP
CHANNEL FROM 20 TO 60 NM.
&&
$$
TE/81...SHORT TERM/AVIATION
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1133 AM MST THU FEB 23 2012
.UPDATE...VERY COLD TEMPERATURES IN THE UPPER TROUGH WILL BE
OVERHEAD TODAY...AND RUC IS FORECASTING VERY STEEP LAPSE RATES WITH
INCREASING LLVL INSTABILITY THROUGH THE DAY. VISIBLE SATELLITE
LOOP SHOWS A BROAD AREA OF MORE CONVECTIVE TYPE CLOUDS WHICH FIT WELL
WITH THE RUC FORECAST OF INSTABILITY. SO BUMPED UP SNOW CHANCES
ACROSS THE FORECAST AREA FOR THIS AFTERNOON...ESPECIALLY AREAS IN
AND NEAR THE LARAMIE RANGE WHICH WERE ON THE LOW SIDE TO BEGIN THE
DAY. COULD SEE LOCALLY HIGHER SNOWFALL RATES AT TIMES WITH THE
SHOWERS...BUT QUICK DURATION WILL ONLY ALLOW MINIMAL ACCUMULATIONS
TO OCCUR. EXCEPTION WILL BE IN THE MOUNTAINS ABOVE 9000 FEET WHICH
SHOULD SEE MORE NUMEROUS SHOWERS PASS OVERHEAD DO TO ADDITIONAL
TERRAIN FORCING...SO AN ADDITION 1 TO 4 INCHES OF SNOW IS POSSIBLE
THROUGH THIS EVENING HERE.
WIND ADVISORY FOR THE NEBRASKA PANHANDLE LOOKS TO BE IN GOOD SHAPE
AS MESOWEST PLOT SHOWS A NUMBER OF SITES ARE SUSTAINED NEAR 30
MPH WITH GUSTS AROUND 45 MPH. RJM
&&
.PREV DISCUSSION... /ISSUED 1027 AM MST THU FEB 23 2012/
AVIATION...18Z TAF ISSUANCE...
MAINLY VFR OVER THE TERMINALS THROUGH FRIDAY UNDER NW FLOW ALOFT.
SOME HIGHER MTN OBSCURATIONS AND ASSOCIATED SNOW SHOWERS THOUGH AS
MOISTURE RIDES UP THE NW FACING SLOPES. SCTD BRIEF MVFR CIGS/VSBYS
OVER THE PLAINS THIS AFTERNOON IN SNOW SHOWERS AS UPPER DISTURBANCE
MOVES ACROSS THE REGION AND INTERACTS WITH SOME WEAK INSTABILITY.
GUSTY SFC WINDS OVER MAINLY THE NEB PANHANDLE THIS AFTERNOON...
DIMINISHING EARLY THIS EVENING. -RE-
PREV DISCUSSION... /ISSUED 420 AM MST THU FEB 23 2012/
UPDATE...
LATEST RADAR IMAGERY SHOWING PRECIPITATION SHIFTING SOUTH INTO
COLORADO WITH THE COLD FRONT. SNOTELS ARE NOT SHOWING MUCH IN THE
WAY OF ACCUMULATIONS ANYMORE. WENT AHEAD AND CANCELLED THE WINTER
STORM WARNINGS A LITTLE EARLIER THAN ANTICIPATED. UPDATES HAVE BEEN
SENT. -CLAYCOMB-
PREV DISCUSSION... /ISSUED 241 AM MST THU FEB 23 2012/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT
CURRENTLY...COLD FRONT WELL INTO NORTHERN COLORADO THIS MORNING.
MESONET OBSERVATIONS SHOWING WINDS DECREASING UNDER WARNING
CRITERIA. SOME SPOTS IN THE PANHANDLE HAVE ALREADY BEEN HITTING
ADVISORY CRITERIA...SO WENT AHEAD AND STARTED THE WIND ADVISORY
FOR THE PANHANDLE NOW INSTEAD OF 5 AM AND CANCELLED THE HIGH WIND
WARNING. AREA OF SNOW DECREASING ON RADAR AS WELL WITH ONLY THE
SOUTHERN HALF OF THE CWA NOW SHOWING ANY ECHOES. LOOKS LIKE THE
WINTER STORM WARNING FOR THE SNOWY AND SIERRA MADRE RANGES WILL BE
GOOD TO EXPIRE AT 5 AM AS WELL. WILL GET SOME SNOW REPORTS OUT IN
LSR FORMAT ONCE THE FORECAST PACKAGE IS SENT OUT.
COLD FRONT FORECAST TO BE IN SOUTHERN COLORADO BY 18Z TODAY. WOULD
THINK MAJORITY OF SNOW WILL END EARLY THIS MORNING AS THE FRONT
CONTINUES SOUTH. WE STAY FAIRLY COLD TODAY AS 700MB TEMPERATURES
STAY FROM -14 TO -16C. HIGHS WILL STRUGGLE TO GET OUT OF THE 30S
TODAY EAST OF THE LARAMIE RANGE...PROBABLY STAY BELOW FREEZING WEST.
SEE A SLIGHT WARM UP FRIDAY AS UPPER RIDGE BUILDS INTO THE AREA.
700MB TEMPERATURES CLIMB TO AROUND -10C. LOOKING AT HIGHS IN THE
UPPER 30S WITH POSSIBLY LOW 40S IN THE PANHANDLE. RIDGE AXIS
PASSES AROUND 12Z SATURDAY.
LOOKS LIKE ANOTHER POSSIBLE HIGH WIND EVENT SATURDAY AFTER THE
RIDGE PASSES. 700MB WINDS INCREASE TO 45 KTS AT 12Z
SATURDAY...INCREASING TO 55/60KTS SATURDAY AFTERNOON. CRAIG TO
CASPER 700MB GRADIENT PRETTY TIGHT SATURDAY AFTERNOON...UP TO 100
MTRS AHEAD OF A FAST MOVING COLD FRONT POSITIONED IN WESTERN
WYOMING BY SATURDAY EVENING. WILL LET THE DAY SHIFT TAKE ANOTHER
LOOK TODAY FOR ANY WIND HEADLINES WITH THIS SYSTEM.
RUN TO RUN CONSISTENCY ON THE SUNDAY SYSTEM STILL TERRIBLE. BOTH
THE GFS AND ECMWF NOW HAVE THE UPPER SHORTWAVE NORTH ACROSS
SOUTHERN MONTANA AND SOUTH DAKOTA...NOT A VERY GOOD POSITION FOR
US TO GET A LOT OF SNOW. BUT THIS IS A GOOD LOCATION FOR CONTINUED
HIGH WINDS.
LONG TERM...SUNDAY THROUGH WEDNESDAY
SOUTHEAST WY WILL BE ON THE BACKSIDE OF THE EXITING STORM SYSTEM
ON SUNDAY. AS SUCH...TEMPERATURES WILL BE BELOW NORMAL WITH GFS
PROGGED 700MB TEMPS AROUND AROUND -14C. SOME LINGERING 700-500MB
MOISTURE WILL PRODUCE A CHANCE OF SNOW IN THE SIERRA MADRE/SNOWY
RANGES BUT ACCUMULATIONS WILL BE INSIGNIFICANT. WITH NORTHWESTERLY
700MB WINDS AROUND 40 KTS THROUGH SUNDAY AFTN ADVISORY LEVEL WINDS
MAY CONTINUE TO BE A CONCERN ACROSS THE NEBRASKA PANHANDLE. BY
MONDAY NIGHT...THE GFS AND ECMWF ARE IN GENERAL AGREEMENT IN
SHOWING A MIDLEVEL TROUGH DIGGING INTO THE INTERMOUNTAIN WEST AND
THEN PROGRESSING EASTWARD ACROSS CO ON TUESDAY. THE ECMWF IS
ABOUT 12 HOURS SLOWER WITH THE UPPER AND LOWER LEVEL FEATURES. BOTH
MODELS SHOW SFC PRESSURE FALLS ACROSS SE CO AND ASSOCIATED
FAVORABLE UPSLOPE N/NE LLVL WINDS OVER THE PLAINS. WILL NOT HIT
PRECIP CHANCES TOO HEAVILY AT THIS POINT SINCE IT IS ALMOST SIX
DAYS AWAY. HOWEVER...THIS STORM SYSTEM COULD BE THE NEXT MODERATE
SNOW MAKER FOR ALL AREAS OF THE CWA. MODEL FCSTS SHOW THE MID AND
UPPER LEVEL FLOW BECOMING MORE ZONAL AFTER THE PASSAGE OF THE TUES
TROUGH.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. NORTHWEST WINDS
THIS AFTERNOON WILL BE MODERATE TO STRONG...ESPECIALLY ACROSS THE
NEBRASKA PANHANDLE WHERE SUSTAINED WINDS 3O TO 35 MPH WITH GUSTS
TO 45 MPH ARE EXPECTED. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL
BE IN THE 40 TO 50 PERCENT RANGE TO THE EAST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...WIND ADVISORY UNTIL 5 PM THURSDAY FOR NEZ002-NEZ003-NEZ019-
NEZ020-NEZ021-NEZ054-NEZ055-NEZ095-NEZ096.
&&
$$
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM...FINCH
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 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 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
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 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 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 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
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 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 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 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 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 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 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...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 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 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 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...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
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