FXUS61 KALY 091621
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1121 AM EST WED DEC 9 2009
.SYNOPSIS...
A STORM WILL MOVE ACROSS MICHIGAN TODAY...AS A SECOND STORM DEVELOPS
OVER THE MID ATLANTIC STATES. THE COMBINATION OF THESE TWO STORMS
WILL SPREAD A VARIETY OF WINTER WEATHER INTO THE REGION INTO THE AFTERNOON.
AS THE MAIN LOW PRESSURE SYSTEM TRACKS INTO CANADA ON THURSDAY...A
BRISK FLOW OF COLDER AIR WILL FOLLOW IN ITS WAKE WITH HEAVY LAKE
EFFECT SNOW POSSIBLE ACROSS THE ADIRONDACKS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER UPDATE TO DO THE FOLLOWING...
1. TO DROP THE FLOOD WATCH FOR ULSTER...DUTCHESS...AND LITCHFIELD
COUNTIES. MOST THESE AREAS HAD 4-9 INCHES OF SNOWFALL BEFORE A
QUICK TRANSITION TO MAINLY LIGHT RAIN. ADDITIONAL QPF LOOKS LIKE
IT WILL BE UNDER A QUARTER OF AN INCH. THE LATEST RIVER FORECASTS
LOOK FINE.
2. WE HAVE DROPPED THE WINTER WEATHER ADVISORIES FOR DUTCHESS AND
LITCHFIELD COUNTIES. THE PCPN HAS TRANSITIONED TO SPOTTY LIGHT
RAIN WITH POCKETS OF FREEZING RAIN.
3. WE DROPPED THE WINTER STORM WARNING FOR ULSTER COUNTY...AS THE
PCPN HAS DIMINISHED BASED ON THE LOCAL RADARS.
WE BEEFED UP THE WINDS TO GUSTS OF 45 MPH IN WASHINGTON CO.
DOWNSLOPING IS EVIDENT ON THE VAD WIND PROFILED. PORTIONS OF WRN
BENNINGTON HAVE ONLY RECEIVED 2-4" DUE TO THE E/SE WINDS KDDH HAD
A GUST TO 46 MPH...AND NORTH ADAMS MA TO 48 MPH. ALSO...OUR COOP
SPOTTER IN SUNDERLAND VT HAD A GUST LAST HR TO 43 MPH.
BOTTOM LINE...WIND ADVISORY CONTINUES FOR SOUTHERN
VERMONT...BERKSHIRE COUNTY...AND TACONICS.
PLEASE SEE OUR LATEST PUBLIC INFO STATEMENT WHERE 4-9" OF SNOW HAVE
FALLEN ACROSS MUCH OF THE REGION. SOME RAIN IS MIXING IN OVER THE
MID HUDSON VALLEY AT THIS TIME
MOST THE REGION WILL RECEIVE 5-12" OF SNOW WITH THE HEAVIEST TOTALS
NORTH OF THE MOHAWK RIVER VALLEY...AND OVER THE ERN CATSKILLS.
ALSO...WITH UNOFFICIALLY 7.1" OF SNOW AT 10 AM AT THE ALBANY
NWS/CESTM...THAT WILL LAUNCH US ABOVE NORMAL FOR THE SEASON.
DECEMBER...HAS COME ROARING LIKE A LION WITH THE WINTRY
WEATHER...WITH THE MILD AND SNOWLESS NOVEMBER 2009 A DISTANT
MEMORY !!!
WE WILL UPDATE AGAIN AROUND THE LUNCH TIME HOUR TO LIKELY DROP
MORE OF THE HEADLINES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS UPPER LEVEL SHORTWAVE...AND OCCLUDED FRONT PASS NE ACROSS REGION
THIS EVENING...ANOTHER BRIEF BURST OF SHOWERS ARE EXPECTED. IN
FACT...PREVIOUS MODEL RUNS HINTED AT SOME ELEVATED INSTABILITY...AND
WOULD NOT COMPLETELY RULE OUT AN ISOLATED RUMBLE OF THUNDER.
THEN...AS SUBSIDENCE DEVELOPS IN THE WAKE OF THESE FEATURES...WE
EXPECT PRECIP TO TAPER OFF WITHIN THE VALLEYS...WHILE SOME SNOW
SHOWERS DEVELOP ACROSS HIGHER ELEVATIONS...ESP WITHIN THE DACKS
LATER TONIGHT. WINDS WILL INCREASE FROM THE SW/W LATER TONIGHT...BUT
SHOULD REMAIN BELOW ADV LEVELS. AS FOR MIN TEMPS...GENERALLY SIDED
WITH THE MET MOS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
DECENT PRESSURE GRADIENT ACROSS THE GREAT LAKES THURSDAY WITH WEST
TO SOUTHWEST LOW LEVEL FLOW TRENDING TO WEST AND NORTHWEST THROUGH
THURSDAY NIGHT...FRIDAY AND FRIDAY NIGHT. LAKE EFFECT SNOWS WILL
AFFECT THE SOUTHERN ADIRONDACKS...TRENDING FROM NORTHERN HERKIMER
AND HAMILTON COUNTIES THURSDAY...TO CENTRAL AND SOUTHERN HERKIMER
AND HAMILTON COUNTIES THURSDAY NIGHT THROUGH FRIDAY NIGHT.
SCATTERED SNOW SHOWERS EXPECTED IN CATSKILLS...SOUTHERN GREEN
MOUNTAINS AND BERKSHIRES THROUGH THE PERIOD WITH THE UPSLOPE FLOW.
ISOLATED SNOW SHOWERS IN MANY VALLEY AREAS...EXCEPT PERHAPS IN POU
AREA AND NW CT. BASED ON PREDICTED DEPTH OF MOISTURE AND
INSTABILITY OFF THE LAKES...CONSIDERABLE SNOW EXPECTED IN THE
SOUTHERN ADIRONDACKS...AND LAKE EFFECT SNOW HEADLINES WILL PROBABLY
BE NEEDED ONCE OUR CURRENT EVENT IS DONE.
BASED ON CLOUD COVER AND PREDICTED BOUNDARY LAYER TEMPERATURES AND
POTENTIAL MIXING FROM GUSTY WINDS...HIGHS IN THE LOW TO MID 30S
THURSDAY...WITH 20S IN MOUNTAINS. LOWS THURSDAY NIGHT AND FRIDAY
NIGHT IN THE TEENS...WITH SINGLE NUMBERS IN MOUNTAINS. HIGHS FRIDAY
AND SATURDAY IN THE 20S TO LOWER 30S...WITH AROUND 20 IN THE
MOUNTAINS.
SATURDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE BUILDS INTO THE AREA
FROM THE TN VALLEY AS LOW PRESSURE FINALLY LIFTS OUT OF SOUTHERN
CANADA. LONG RANGE GUIDANCE TRYING TO HINT AT ANOTHER SYSTEM
POTENTIALLY THREATENING SOME PART OF THE EASTERN U.S. IN THE SUNDAY
NIGHT THROUGH TUESDAY TIME FRAME. SPREAD IN GUIDANCE VERY LARGE IN
TERMS OF TIMING AND PLACEMENT OF KEY FEATURES. SO...DID NOT CHANGE
MUCH IN THE SUNDAY NIGHT THROUGH TUESDAY TIME FRAME...EXCEPT TO WARM
TEMPERATURES A FEW DEGREES DUE TO POTENTIAL CLOUD COVER...AND
MOISTURE ADVECTION...AND PUTTING SLIGHT CHANCES FOR PRECIPITATION.
LOWS SATURDAY NIGHT IN SINGLE NUMBERS TO MID TEENS...WITH
POTENTIALLY NEAR ZERO IN THE ADIRONDACKS. HIGHS SUNDAY THROUGH
TUESDAY IN THE LOWER TO MID 30S...WITH 20S IN MOUNTAINS. LOWS
SUNDAY NIGHT AND MONDAY NIGHT IN THE UPPER TEENS TO LOWER
20S...SINGLE NUMBERS IN THE ADIRONDACKS.
MJO TRYING TO REEMERGE INTO A WEAK PHASE 8...BUT WILL SEE IF THAT
TREND CONTINUES...WHICH WOULD FAVOR GENERAL LOW PRESSURE IN EASTERN
NORTH AMERICA. CONSIDERING THE RESPECTABLE CORE OF COLD AIR THAT
CROSSED THE POLE INTO CANADA RECENTLY...MANIFESTING ITSELF AS
MULTIPLE UPPER SYSTEMS ROTATING AROUND A MEAN POLAR VORTEX IN
NORTHERN CANADA...GRADUALLY COLDER AIR WORKING INTO EASTERN U.S.
THE MEAN UPPER TROUGH AXIS IN THE CENTRAL U.S. HAS BEEN
CONTRIBUTING TO A PATTERN IN PAST WEEKS IN WHICH THE GULF OF MEXICO
HAS BEEN OPEN FOR BUSINESS AND STORMS TRACK THROUGH OR OFF THE
EASTERN U.S. THE PATTERN IN THE LONG RANGE IS RIPE FOR POTENTIAL
NORTHERN AND SOUTHERN STREAM PHASING INTO A BIG STORM...BUT
POTENTIAL IS NOT ALWAYS REALIZED...SO WITH THE HINTS AT PIECES OF
THE PUZZLE EXISTING...BUT NOT NECESSARILY FITTING TOGETHER
YET...WILL CONTINUE TO WATCH THE PATTERN EVOLUTION.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
IFR CONDITIONS WILL CONTINUE AS A COMPLEX STORM AFFECTS THE REGION.
ACCUMULATING SNOW WILL CONTINUE THROUGH 13Z-16Z...WHEN
PRECIPITATION WILL TRANSITION TO A MIX WITH SLEET AND RAIN FROM
KPOU SOONEST...TO KGFL LATEST. ALL PRECIPITATION WILL EVENTUALLY
BECOME RAIN. CONDITIONS IMPROVE TO MVFR 19Z-22Z AT KPOU AND
KALB...BUT LIKELY TO STAY IFR AT KGFL INTO THE EVENING. POSSIBLE
IMPROVEMENT TO VFR AT POU DURING THE EVENING....THEN VFR AT KALB
AND KGFL DURING THE LATE EVENING AND OVERNIGHT. WINDS THROUGH THE
PERIOD WILL BE NORTHEAST TO SOUTHEAST AT 10 KT OR LESS...THEN
SHIFTING TO WEST AND SOUTHWEST LATE THIS AFTERNOON AT 10 TO 15
KT...CONTINUING THIS EVENING.
SOUTHEASTERLY LOW LEVEL WINDS...AROUND 2000 FEET...WILL BECOME
STRONG...35-50 KNOTS...THIS MORNING FOR A PERIOD....SO HAVE
LOW LEVEL WIND SHEAR AT ALL TAF SITES.
OUTLOOK...
THUR...WINDY. VFR-MVFR WITH CHC -SHSN AT THE TAF SITES AND LAKE
EFFECT SNOW DEVELOPING DOWNWIND FROM LAKE ONTARIO AND UPSLOPE SNOW
IN THE SOUTHERN GREEN MOUNTAINS AND NORTHERN/CENTRAL TACONICS.
FRI...CONTINUED WINDY. VFR WITH SLIGHT CHC -SHSN AT THE TAF SITES
AND LAKE EFFECT SNOW PERSISTING DOWN WIND FROM LAKE ONTARIO.
SAT...VFR. NO SIG WX.
SUN...VFR-MVFR...CHC -SHSN.
&&
.HYDROLOGY...
THE FLOOD WATCH HAS BEEN CANCELED FOR ULSTER...DUTCHESS AND
LITCHFIELD COUNTIES. SNOW THAT FELL EARLIER THIS MORNING WILL
SOAK UP MOST...IF NOT ALL...OF THE RAIN THAT CAME LATER.
SOME SLIGHT INCREASES IN FLOW WILL OCCUR ON THE RONDOUT...
WAPPINGERS...TENMILE...AND HOUSATONIC RIVERS. FARTHER NORTH...
RIVERS WILL CONTINUE TO RECEDE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ054-061.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ032-
033-038>043-047>054-058>061-082>084.
MA...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MAZ001-025.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MAZ001-
025.
VT...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR VTZ013-014.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
VTZ013>015.
&&
$$
SYNOPSIS...KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS
HYDROLOGY...RCK
