519
FXUS61 KALY 091730
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1230 PM EST TUE FEB 9 2010
SYNOPSIS
A RIDGE OF HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION
THIS AFTERNOON...AND OFF THE NEW ENGLAND COAST TONIGHT. LOW PRESSURE
WILL DEVELOP ALONG THE MID ATLANTIC COAST LATE TONIGHT...AND MOVE
NORTHEAST PASSING SOUTH OF LONG ISLAND LATE WEDNESDAY. THIS WILL
BRING SNOW TO MUCH OF THE REGION ON WEDNESDAY...WITH THE BEST CHANCE
FOR SIGNIFICANT SNOWFALL OCCURRING SOUTH AND EAST OF ALBANY.
NEAR TERM /UNTIL 6 PM THIS EVENING/
AS OF 1140 AM EST...SKIES REMAIN GENERALLY CLEAR ACROSS THE
CWA...WITH THE EXCEPTION BEING JUST SOME LINGERING LOW LEVEL LAKE
MOISTURE SITUATED ACROSS THE WESTERN MOHAWK VALLEY. HOWEVER...THE
NEARLY CLEAR SKIES WILL BE SHORT LIVED...AS MID/HIGH LEVEL CLOUDS
CURRENTLY OVER WESTERN NY/CENTRAL PA STREAM TOWARDS THE REGION.
HAVE UPDATED THE GRIDS TO ACCOUNT FOR LATEST T/TD TRENDS...BUT
CURRENT FORECASTED MAX TEMPS LOOK ON TRACK...SO NO CHANGES THERE.
LATEST MODEL GUIDANCE ROLLING IN SHOWS HIGHER QPF FOR UPCOMING
EVENT ACROSS THE CWA...ESP THE 12 UTC NAM WHICH NOW SHOWS CLOSE TO
0.70 INCHES LIQUID AT KALB. AM CURRENTLY EVALUATING THIS LATEST
GUIDANCE AND WILL BE ADDRESSING HEADLINES...INCLUDING WARNINGS AND
ADVISORIES.
PREVIOUS DISCUSSION BELOW...
AS OF 4 AM EST...SKIES REMAIN CLEAR ACROSS MUCH OF THE NORTH
COUNTRY INTO SOUTHERN VT...WHILE PATCHY CLOUDS PERSIST ACROSS THE
WESTERN MOHAWK VALLEY AND SCHOHARIE VALLEY INTO THE EASTERN
CATSKILLS. TEMPS HAVE FALLEN INTO THE SINGLE DIGITS WITHIN
SHELTERED LOCALES WHERE SKIES HAVE CLEARED...WHILE REMAINING
BETWEEN 15 AND 20 WHERE CLOUDS REMAIN...AND ALSO WITHIN CLOSE
PROXIMITY TO THE MOHAWK RIVER VALLEY INCLUDING THE IMMEDIATE
CAPITAL DISTRICT...WHERE W/NW WINDS HAVE HELD UP...PREVENTING
TEMPS FROM FALLING.
FOR TODAY...WE EXPECT SOME CLOUDS TO REDEVELOP THIS MORNING...AS LOW
LEVEL LAKE MOISTURE BECOMES TRAPPED BENEATH A LOWERING SUBSIDENCE
INVERSION. GIVEN A GENERAL WNW/NW LOW LEVEL WIND...IT APPEARS THAT
THE BEST CHANCE FOR SOME CLOUDS AND EVEN A FEW FLURRIES WILL REMAIN
ACROSS WESTERN AREAS...ALTHOUGH SOME MAY ALSO DEVELOP ACROSS UPSLOPE
AREAS WITHIN SW VT AND THE BERKSHIRES ONCE MIXING INCREASES THIS
MORNING. THESE LOWER CLOUDS SHOULD THEN DISSIPATE THIS
AFTERNOON...JUST AS HIGH/MID LEVEL CLOUDS IN ADVANCE OF NEXT STORM
SYSTEM SPREAD NORTHEAST INTO THE REGION.
FOR MAXES...FORECAST SOUNDINGS INDICATE SOMEWHAT MORE SHALLOW MIXING
THAN RECENT DAYS...AS SUBSIDENCE INVERSION LOWERS TO AROUND 925 MB.
THEREFORE...FOR MAXES...GENERALLY SIDED WITH THE SLIGHTLY COOLER MET
MOS IN MOST AREAS...WITH MAXES RANGING FROM THE UPPER TEENS/LOWER
20S ACROSS HIGHER ELEVATIONS WITHIN THE WESTERN DACKS...TO 30-35
WITHIN THE HUDSON RIVER VALLEY.
SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/
WINTER STORM WATCH REMAINS IN EFFECT FOR
ULSTER/DUTCHESS/LITCHFIELD COS FOR WED AM INTO LATE WED NT...
TONIGHT...CLOUDS WILL INCREASE/THICKEN FROM SW TO NE OVERNIGHT. SOME
LIGHT SNOW SHOULD DEVELOP ACROSS SOUTHWESTERN AREAS...MAINLY ACROSS
THE EASTERN CATSKILLS SE INTO THE MID HUDSON VALLEY AND NW CT A FEW
HOURS PRIOR TO DAYBREAK...WHERE PERHAPS UP TO AN INCH OF ACCUM COULD
OCCUR BY DAYBREAK. ELSEWHERE...ALTHOUGH SOME LIGHT SNOW OR FLURRIES
MAY DEVELOP AS FAR N/E AS THE CAPITAL REGION PRIOR TO
DAYBREAK...LITTLE OR NO ACCUM IS EXPECTED. FOR MINS...GENERALLY
FOLLOWED CLOSE TO THE MET MOS.
WED...BOTH DETERMINISTIC MODELS AND ENSEMBLE GUIDANCE CONTINUE TO
FAVOR A MORE SOUTHWARD TRACK OF THE UPPER LEVEL LOW...AND ASSOCIATED
SFC DEVELOPMENT ALONG/OFF THE NORTHERN MID ATLANTIC COAST...WITH
REDUCED QPF ACROSS THE REGION. HOWEVER...DESPITE THIS...THERE IS
STILL THE POSSIBILITY OF WARNING LEVEL SNOWFALL ACROSS PORTIONS OF
THE MID HUDSON VALLEY AND NW CT...WITH THE GREATEST POTENTIAL WITHIN
SOUTHERN LITCHFIELD CO. SINCE MODELS CONTINUE TO TREND
SOUTHWARD...WITH INCREASING UNCERTAINTY FOR WARNING LEVEL SNOWFALL
ACROSS THESE AREAS...WE HAVE MAINTAINED THE WATCH...AND HAVE HELD
OFF ANY UPGRADES TO A WARNING. IN FACT...BASED ON THE
00Z/NAM12...ONLY EXTREME SOUTHERN PORTIONS OF THESE COUNTIES COME
CLOSE TO WARNING CRITERIA. THE 00Z/09 MREFS ALSO CONTINUE TO TREND
DOWNWARD WITH QPF...WITH MAJORITY OF MEMBERS NOW INDICATING LESS
THAN 0.25 QPF AT ALBANY. SO...EXPECT GENERALLY 3-6 INCHES FOR AREAS
SOUTH/EAST OF THE IMMEDIATE CAPITAL REGION...INCLUDING AT LEAST THE
SOUTHERN BERKSHIRES...AS WELL AS SCHOHARIE VALLEY AND NE CATSKILLS.
THE TRICKIEST PORTION OF THE FORECAST SNOWFALL AMTS APPEAR TO BE
ACROSS THE IMMEDIATE CAPITAL REGION...WHICH WILL LIE WITHIN THE
SHARP NORTHERN EDGE OF PRECIP. AT THIS TIME...HAVE INDICATED 1-3
INCHES ACROSS THIS REGION...WITH GENERALLY AROUND AN INCH EXPECTED
FOR NORTHERN PORTIONS OF THE CAPITAL REGION...INCLUDING THE SARATOGA
REGION. FURTHER N...ONLY A DUSTING TO LESS THAN AN INCH IS EXPECTED
AT THIS TIME...PENDING ANY POSSIBLE NORTHWARD TRENDS WITH THE STORM
TRACK.
WED NT-THU NT...SNOW SHOULD TAPER OFF FROM NW TO SE WED
EVENING...WITH ONLY SCATTERED SNOW SHOWERS EXPECTED LATER WED NT.
FOR THU-THU NT...SCATTERED SNOW SHOWERS WILL REMAIN POSSIBLE ACROSS
WESTERN AREAS...AND ALSO WITHIN OROGRAPHICALLY FAVORED AREAS ACROSS
WESTERN NEW ENGLAND. FORTUNATELY...GIVEN A MORE NNW FLOW...IT
APPEARS THAT LAKE EFFECT POTENTIAL IS LIMITED DURING THE THU-THU NT
TIME FRAME. EXPECT TEMPS TO REMAIN BELOW SEASONAL LEVEL THROUGH THIS
PERIOD...WITH MAXES MAINLY IN THE 20S TO LOWER 30S...AND OVERNIGHT
MINS MAINLY IN THE SINGLE DIGITS ACROSS THE NORTH COUNTRY...AND
TEENS WITHIN THE HUDSON RIVER VALLEY.
LONG TERM /FRIDAY THROUGH MONDAY/
FRI-SUN...STRONG W-NW FLOW AROUND UPPER LOW OVER CANADIAN MARITIMES
WILL RESULT IN BOTH SOME LAKE EFFECT AND OROGRAPHICALLY ENHANCED
SNOW SHOWERS ACROSS THE SOUTHERN ADIRONDACKS AND PARTS OF SOUTHERN
VERMONT. UPPER LOW AND SURFACE LOW ARE EXPECTED TO GRADUALLY BACK TO
THE WEST/SOUTHWEST WITH TIME THROUGH THE CANADIAN MARITIMES FROM
FRIDAY THROUGH SUNDAY. HAVE THUS PUT SLIGHT CHANCE TO CHANCE POPS IN
THE GRIDS DURING THIS PERIOD ACROSS THE SOUTHERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY AND EARLY ON IN THE PERIOD ACROSS SOUTHERN
VERMONT. EXPECT HIGHS IN THE MID 20S TO MID 30S WITH LOWS IN THE
SINGLE DIGITS TO MID TEENS...WHICH ARE SEASONABLE TO SLIGHTLY BELOW
NORMAL VALUES FOR MID FEBRUARY.
ON MONDAY IT LOOKS AS THOUGH THE FA WILL HAVE A BETTER CHANCE OF
SOME SNOW OR SNOW SHOWERS AS A WEAK SURFACE LOW AND UPPER LOW OR
TROUGH MOVE ACROSS THE FORECAST AREA. SINCE THIS IS DAY 7 AND TIMING
MAY CHANGE HAVE PLACED SLIGHT CHANCE POPS ACROSS EASTERN ZONES AND
CHANCE POPS ACROSS WESTERN ZONES WITH HIGHS IN THE MID 20S NORTHWEST
TO MID 30S SOUTHEAST.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING HOURS AT ALL
TERMINALS. NEARLY CLEAR SKIES EARLY THIS AFTN WILL GIVE WAY TO
INCREASING AMOUNTS OF MID/HIGH LEVEL CLOUDS FROM THE SOUTH AND
WEST...BEGINNING IN THE EVENING HOURS AND CONTINUING TO INCREASE
OVERNIGHT.
PRECIP IN THE FORM OF SNOW WILL ARRIVE AT KPOU AS EARLY AS 08Z...AND
REACH KALB BY 11Z...AND KGFL BY 13Z. THE SNOW WILL BEGIN LIGHT IN
INTENSITY...BUT WILL REDUCE VSBYS TO MVFR. A FEW HOURS AFTER
ARRIVAL...THE SNOW WILL PICK UP IN INTENSITY AT KALB AND KPOU TO
REDUCE VSBYS TO IFR LEVELS...ALTHOUGH KGFL MAY REMAIN MVFR FOR MUCH
OF THE MORNING HOURS...AS THEY WILL BE ON THE FAR NORTHERN FRINGE OF
THE PRECIP.
WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...BEFORE BECOMING
NORTHERLY BY WED MORN AT 5-10 KTS. WIND SPEEDS WILL INCREASE TO NEAR
10 KTS BY THE AFTN...ESP AT KPOU...AS THE SFC LOW RAPIDLY DEEPENS
OFFSHORE.
OUTLOOK...
WED PM...MVFR-IFR IN SNOW...EXCEPT VFR/MVFR KGFL CHC OF SNOW.
THU-SAT...VFR...NO SIG WX.
HYDROLOGY
NO HYDRO PROBLEMS ANTICIPATED THIS WEEK. ANY PRECIPITATION THAT
OCCURS OVER THE REGION WILL COME IN THE FORM OF SNOW. ICE WILL
CONTINUE TO INCREASE ON MAIN STEM RIVERS...STREAMS AND LAKES.
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...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE
WEDNESDAY NIGHT FOR CTZ001-013.
NY...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH LATE
WEDNESDAY NIGHT FOR NYZ063>066.
MA...NONE.
VT...NONE.
SYNOPSIS...FRUGIS/KL
NEAR TERM...FRUGIS/KL
SHORT TERM...KL
LONG TERM...11
AVIATION...FRUGIS
HYDROLOGY...SND
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