000
FXUS61 KALY 100904
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
403 AM EST WED FEB 10 2010

.SYNOPSIS...
LOW PRESSURE DEVELOPING ALONG THE MID-ATLANTIC COAST WILL TRACK 
NORTHEAST...PASSING SOUTH OF LONG ISLAND BY LATE THIS AFTERNOON.  
THIS WILL BRING SNOW TO MOST...IF NOT ALL...OF THE REGION TODAY... 
WITH THE BEST CHANCE FOR HEAVY SNOWFALL OCCURRING MAINLY SOUTH AND 
EAST OF ALBANY. IN THE WAKE OF THIS STORM...BLUSTERY CONDITIONS WILL 
PERSIST INTO FRIDAY...ALONG WITH SCATTERED SNOW SHOWERS AND FLURRIES.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
...ALL WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES REMAIN 
UNCHANGED AT THIS TIME...

AS OF 4 AM EST...SOME PATCHY LIGHT SNOW CONTINUES TO AFFECT MAINLY 
SOUTHERN PORTIONS OF THE REGION...WITH MAINLY CLOUDY SKIES ELSEWHERE.

OUR REGION LIES WITHIN A RELATIVE CALM...WHEREAS AREAS TO THE S ARE 
BEGINNING TO EXPERIENCE THE DOWNHILL EFFECTS OF THE INTENSIFYING 
LOW...CURRENTLY JUST E OF THE DELMARVA PENINSULA. STRONG 
MID LEVEL FRONTOGENETICAL FORCING HAS ALLOWED BANDS OF MOD-HVY 
PRECIP TO DEVELOP ACROSS CENTRAL PA E INTO NJ AND JUST S OF LONG 
ISLAND. AS THE UPPER LEVEL LOW APPROACHES FROM THE W...WE EXPECT 
THESE BANDS OF PRECIP TO CONTINUE DEVELOPING N...REACHING SE 
CATSKILLS...MID HUDSON VALLEY AND NW CT REGION A FEW HOURS AFTER 
DAYBREAK...WITH PERIODS OF MOD-HVY SNOW CONTINUING IN THESE REGIONS 
THROUGH THE AFTERNOON. IN THESE REGIONS...WE HAVE FOLLOWED A BLEND 
OF THE HPC QPF...AND THE RUC13...WHICH IS MUCH FURTHER N AND NW WITH 
HIGHER PRECIP AMTS THAN THE GFS/NAM. WE EXPECT THE SNOW TO REACH THE 
CAPITAL REGION AROUND MIDDAY...AND AREAS FURTHER N BY EARLY-MID 
AFTERNOON.

AS FAR AS ACCUMS...AGAIN NOTING THE MORE AGGRESSIVE RUC13...WE HAVE 
INDICATED 8-16 INCHES ACROSS EXTREME SOUTHERN AREAS...MAINLY FROM 
SOUTHERN DUTCHESS CO INTO SOUTHERN LITCHFIELD CO...WITH GENERALLY 
8-12 INCHES ACROSS THE REMAINDER OF THE WARNING AREA. FURTHER N...WE 
HAVE CONTINUED AMTS OF 3-6 INCHES WITHIN THE ADVISORY AREA...WITH 
GENERALLY UNDER 3 INCHES FURTHER N.

OF COURSE...THERE ARE STILL SOME UNCERTAINTIES INVOLVED WITH THIS 
RAPIDLY EVOLVING STORM SYSTEM...WHICH CAN LEAD TO ADDITIONAL CHANGES 
IN AFOREMENTIONED AMTS. FIRST AND FOREMOST...BANDING POTENTIAL 
REMAINS QUITE HIGH FOR AREAS S/E OF ALBANY...WHERE STRONGEST MID 
LEVEL F-GEN IS EXPECTED. WITHIN THESE BANDS...INTENSE SNOWFALL RATES 
OF 2-3 INCHES/HOUR CAN LEAD TO LOCALLY HIGHER AMTS THAN CURRENTLY 
FORECAST. SECOND...TERRAIN EFFECTS FROM A STRENGTHENING NE FLOW WILL 
ALSO LIKELY LEAD TO WIDELY VARYING AMTS...WITH SOME UPSLOPE AREAS 
WITHIN THE BERKSHIRES...TACONICS AND CATSKILLS LIKELY RECEIVING 
HEAVIER SNOWFALL...WHILE DOWNSLOPING/SHADOWED AREAS MAY ONLY RECEIVE 
SEVERAL INCHES OR LESS. THIS COULD OCCUR WITHIN THE CAPITAL REGION 
AS WELL AS THE INCREASING EASTERLY WIND COMPONENT ENHANCES 
DOWNSLOPING. FINALLY...THE NORTHERN EDGE OF THE PRECIP WILL LIKELY 
BE QUITE SHARP...WITH ONLY LIGHT SNOW EXPECTED FOR THE LAKE 
GEORGE/SARATOGA REGION AND ACROSS THE DACKS.

SO...THE BOTTOM LINE...PLEASE STAY TUNED AS FORECASTS WILL LIKELY BE 
TWEAKED ACCORDING TO RADAR TRENDS AND INCOMING SNOWFALL REPORTS 
THROUGH THE EVENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...SNOW SHOULD GRADUALLY TAPER OFF FROM NW TO SE AS THE STORM 
PULLS E...AND THE MAIN FORCING SETTLES SOUTHWARD. HOWEVER...GUSTY 
WINDS IN THE WAKE OF THE STORM WILL LIKELY LEAD TO ADDITIONAL AREAS 
OF BLOWING SNOW...ESPECIALLY ACROSS SOUTHERN AREAS WHERE THE CURRENT 
WARNING IS IN EFFECT. OTHERWISE...SOME SCATTERED SNOW 
SHOWERS/FLURRIES MAY LINGER THROUGH THE NIGHT ACROSS 
FAVORABLE...UPSLOPE AREAS WITHIN THE DACKS AND SW VT...BUT LITTLE IF 
ANY ACCUM IS EXPECTED. FOR MINS...GENERALLY SIDED WITH A MAV/MET MOS 
BLEND. HOWEVER...SHOULD ANY SOUTHERN AREAS EXPERIENCE A DECREASE IN 
WIND ALONG WITH BREAKS IN THE CLOUDS...MUCH COLDER MINS ARE POSSIBLE.

THU-FRI...EXPECT BLUSTERY CONDITIONS IN THE WAKE OF THE STORM 
SYSTEM...ALONG WITH SCATTERED SNOW SHOWERS AND FLURRIES. SNOW 
SHOWERS SHOULD BE MORE PERSISTENT ACROSS WESTERN AREAS...FROM THE 
WESTERN DACKS INTO THE SCHOHARIE VALLEY AND EASTERN CATSKILLS DUE TO 
SOME LAKE EFFECTS...AS WELL AS WITHIN UPSLOPE AREAS OF SOUTHERN VT 
AND THE BERKSHIRES. IN THESE AREAS...MINOR ACCUMS OF A FEW INCHES 
COULD OCCUR...ESP ON FRI...WHEN WINDS BACK INTO A MORE WESTERLY 
DIRECTION THROUGH A DEEPER DEPTH OF THE LOWER ATMOSPHERE. 
OTHERWISE...FOR MAXES...GENERALLY FOLLOWED A MAV/MET MOS 
BLEND...WITH UPPER 20S/LOWER 30S IN THE VALLEYS...AND TEENS TO LOWER 
20S FOR HIGHER ELEVATIONS. FOR MINS...EXPECT MAINLY TEENS IN THE 
VALLEYS...WITH SINGLE DIGITS FOR MANY NORTHERN AREAS...AS WELL AS 
ISOLATED SOUTHERN AREAS WHERE WINDS COULD DIMINISH.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN EVOLVING HIGHLY AMPLIFIED AND BLOCKING PATTERN WILL BE OUR 
FORECAST DILEMMA HEADING INTO THIS WEEKEND.  LATEST TRENDS IN THE 
GLOBAL MODELS ARE IN RATHER GOOD AGREEMENT THIS MORNING WITH THIS 
FORECAST PATTERN...BUT THEY DO DIFFER WITH INDIVIDUAL SHORT WAVES 
NEAR THE VICINITY OF LAKE WINNIPEG.

AS OUR CURRENT NOREASTER TRACKS NORTHEAST INTO THE CANADIAN 
MARITIMES...IT WILL BECOME ABSORBED INTO THE UPPER LOW AND BECOME 
DOMINANT PLAYER WITH A PERSISTENT NORTHWEST FLOW REGIME OVER THE 
REGION.  AMPLE MOISTURE WILL ACCOMPANY THIS PATTERN WITH THE CHANCE 
FOR MAINLY TERRAIN SNOW SHOWERS...WITH SOME THESE SHOWERS 
PROGRESSING INTO THE VALLEY INTO THE WEEKEND.  TEMPERATURES WILL 
REMAIN BELOW NORMAL THROUGH THE WEEKEND.

OF MORE INTEREST WILL BE THE POTENTIAL FOR A SIGNIFICANT STORM 
DEVELOPMENT OFF THE MID ATLANTIC COAST FOR EARLY NEXT WEEK.  PV 
TRACE ANOMALY POINTS TOWARD A SHORT WAVE JUST NORTH OF MANITOBA AND 
SASKATCHEWAN PROVINCE BORDER.  THIS FEATURE IS EVIDENT PER THE H2O 
VAPOR LOOP THIS MORNING...BUT HOW ITS MAINTAINS ITS STRUCTURE AND 
STRENGTH REMAINS TO BE SEEN AS IT TRACKS SOUTHEAST INTO THE LOWER 
48.  FOR NOW...WILL MAINTAIN A CHANCE FOR SNOW AND LEAVE OUT OF THE 
HWO AT THIS TIME.  

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
DETERIORATING CONDITIONS EXPECTED THE REMAINDER OF THE OVERNIGHT AND 
ESPECIALLY DURING THE DAY WEDNESDAY.  MVFR TO IFR CONDITIONS WILL 
SPREAD FROM SOUTH TO NORTH WITH THE STRONGEST IMPACT FROM VLIFR 
CONDITIONS FOR KPOU.  IN ADDITION...CONSIDERABLE BLOWING AND 
DRIFTING OF THE SNOW WILL MAKE FOR ADDITIONAL COMPLICATIONS 
PERTAINING TO AVIATION.  THE POTENTIAL FOR LLWS WILL EXIST SOUTH OF 
KALB BY THIS AFTERNOON AND WILL REEVALUATE IN LATER FORECAST 
ISSUANCES. 

WINDS WILL BE NEARLY CALM OVERNIGHT...WITH A NORTHERLY SURFACE FLOW 
INCREASING AS THE STORM INTENSIFIES AND MOVES OFF THE DELMARVA 
PENINSULA WEDNESDAY.  SUSTAINED WINDS FROM 12 TO 20 KNOTS...WITH 
GUSTS OVER 20 KNOTS ARE LIKELY DURING THE IFR PORTION OF THE EVENT.  
THE AFOREMENTIONED WINDS AT THE 2000-FOOT LEVEL START OFF VERY 
LIGHT...BUT WILL ALSO INCREASE...TO 25 TO 35 KNOTS BY THE END OF THE 
TAF PERIOD.

OUTLOOK...
WED NGT...-SN TAPERING OFF...IMPROVING TO VFR OVRNT.
THU-SUN...VFR...NO SIG WX.  SLGT CHC --SN SATURDAY.

&&

.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 WARNING UNTIL 1 AM EST THURSDAY FOR CTZ001-013.
NY...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR NYZ058>061-
     063>066.
     WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR NYZ038>040-
     047>054-082.
MA...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR MAZ001-025.
VT...WINTER WEATHER ADVISORY UNTIL 1 AM EST THURSDAY FOR VTZ013>015.

&&

$$
SYNOPSIS...KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM
HYDROLOGY...SND