FXUS61 KBGM 240848
AFDBGM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
348 AM EST THU DEC 24 2009

.SYNOPSIS...
DRY WEATHER CAN BE EXPECTED THROUGH TONIGHT AS HIGH PRESSURE NOSES 
INTO CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. BY CHRISTMAS 
MORNING...RETURNING MOISTURE WILL BRING THE CHANCE FOR LIGHT 
FREEZING DRIZZLE. A STORM SYSTEM WILL THEN APPROACH FROM THE WEST 
DURING THE DAY WITH THE POTENTIAL FOR RAIN OR FREEZING RAIN...MAINLY 
FOR AREAS WEST OF INTERSTATE 81. PRECIPITATION WILL OVERSPREAD THE 
ENTIRE AREA FRIDAY NIGHT WITH FREEZING RAIN POSSIBLE THROUGH 
SATURDAY MORNING...MOST LIKELY OVER THE WESTERN CATSKILLS. 
PRECIPITATION WILL GRADUALLY WIND DOWN AS SNOW SHOWERS ON 
SUNDAY...WITH LAKE EFFECT SNOW SHOWERS THEN EXPECTED THROUGH THE 
MIDDLE OF THE WEEK. 

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 348 AM...QUIET WX EXPECTED THRU TONIGHT. INVERSION HAS
LOWERED SIGNIFICANTLY TONIGHT...ESSENTIALLY BRINGING AN END TO LK
EFFECT SNOW WITH EXCEPTION OF A FEW SCTD FLURRIES. EXPECT A DRY
DAY AS DRIER AIR MVS IN AND WINDS TURN MORE NERLY COURTESY OF
HIPRES RIDGE BUILDING IN FM CANADA.

LOW CIGS PUSHING SOUTH THRU PA EARLY THIS MRNG ON NRLY H9 FLOW. FLOW 
WILL VEER ARND TO THE NE AND THEN EAST BY 18Z WITH CLDS GRADUALLY 
ERODING. WILL SHOW IMPRVG CONDS ACRS MOST OF NY BY AFTN WITH PCLDY 
SKIES EXPECTED TODAY. 

H9 TEMPS RISE TO NR -2C THIS AFTN. THIS WUD YIELD HIGHS NR 40. HWVR 
MIXING WILL LKLY NOT OCCUR TO THIS LEVEL AND EXPECT MAXES TO TOP OUT 
ONLY IN THE LWR 30S ACRS THE AREA...MID 30S IN VLY LOCATIONS. 

H5 LOW CURRENTLY ROTATING THRU TX/OK PANHANDLES WILL EJECT OFF TO 
THE NORTH AND EAST AND BCM ABSORBED DROPPING INTO NRN PLAINS. 
CONSOLIDATED CLOSED LOW IS EXPECTED TO ROTATE THRU CNTRL PLAINS 
TONIGHT WITH H5 RIDGE AMPLIFYING OVR CWA. 

1040MB SFC HIGH LOCATED OVR NRN QUEBEC WILL LKLY RESULT IN WEDGING 
ACRS A GOOD PART OF THE FA THRU 12Z FRIDAY. THIS FEATURE...COMBINED 
WITH H5 LOW LOCATED FAR TO OUR WEST OVR NE/KS...WL LKLY KEEP 
MEASURABLE PCPN AT BAY THRU TONIGHT.

00Z NAM12 STILL INDICATING LLM WORKING IN ON SERLY FETCH OFF OF 
ATLANTIC LATE TONIGHT...AFFECTING NEPA AND INTO PARTS OF CNTRL SRN 
TIER. TO ACCNT FOR THIS HV INCRSD CLD CVR ACRS SRN ZONES AFT ABOUT 
09Z TONIGHT. CANNOT RULE OUT SOME LIGHT DRIZZLE TWD DAYBREAK BUT AM 
NOT TOTALLY CONVINCED STRATUS LAYER WILL WORK INTO CWA ENUF TO BRING 
IN THREAT FOR DRIZZLE/FRZG DRIZZLE. HWVR WILL LKLY SEE LOW CLDS/FOG 
ACRS HIGHER TERRAIN OF POCONOS LATE TONIGHT. 

TEMPS EXPECTED TO DROP INTO THE TEENS/LOW 20S OVRNGT. HOW FAST THEY 
RISE BY MRNG AND HOW QUICKLY DRIZZLE MVS IN WILL DETERMINE WHETHER 
ANY TRAVEL PROBLEMS MAY EXIST FOR EARLY CHRISTMAS MRNG TRAVEL. 

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 348 AM...LIGHT ICING EVENT EXPECTED FRIDAY INTO SATURDAY...BUT
DUE TO INCREASED HOLIDAY TRAVEL...OVERALL IMPACTS MAY BE
INCREASED. MAIN AREA OF LOW PRESSURE WILL BE ACROSS WEST-CENTRAL
ILLINOIS BY 12Z FRIDAY. A CLASSIC CAD SIGNATURE SHOWS UP ON BOTH
THE NAM AND GFS FROM OUR AREA SOUTH INTO SOUTHWESTERN VIRGINIA.
THIS ALONG WITH A SECONDARY LOW FORMATION FRIDAY NIGHT WILL SET
THE STAGE FOR ICING ACROSS MOST OF THE CWA. THE SAVING GRACE MAY
BE A SOUTHEAST DOWNSLOPING FLOW OF AIR WHICH WILL ACT TO LIMIT QPF
AMOUNTS ACROSS A LARGE CHUNK OF THE AREA.

THE MAIN AXIS OF STEADY PRECIP WILL BE WELL TO OUR SOUTHWEST AS WE
WAKE UP CHRISTMAS MORNING. IT SHOULD BE NOTED THAT SOME AREAS OF
FREEZING DRIZZLE WILL BE POSSIBLE EARLY FRIDAY...WELL AHEAD OF THE
MAIN SHIELD OF PRECIP. THE GFS IS THE ONLY MODEL THAT HINTS AT
SOME LIGHT QPF OVER NORTHERN PA AT THIS POINT. MODEL SOUNDINGS
LOOK GOOD FOR DRIZZLE WITH COMPLETE SATURATION FROM NEAR THE
SURFACE UP THROUGH 2KFT...WITH A PRONOUNCED DRY LAYER ABOVE THAT.
BEST SHOT AT SOME LIGHT FREEZING DRIZZLE EARLY FRIDAY WOULD BE
ACROSS THE HIGHER ELEVATIONS FROM THE SOUTHERN TIER SOUTHWARD.

BOTH THE NAM AND GFS ARE CONSISTENT IN BRINGING IN PRECIPITATION
PRIOR TO SUNSET ACROSS MOST OF THE CWA...WITH CHANCE POPS ON A
LINE FROM SYRACUSE TO BINGHAMTON TO AVOCA...WEST BY SUNSET. IN THE
LAKE PLAIN THIS WILL INITIALLY FALL IN THE FORM OF RAIN BUT
POCKETS OF FREEZING RAIN ARE POSSIBLE ACROSS THE SOUTHERN TIER OF
NY AND NORTHERN PA.

FRIDAY NIGHT A SECONDARY AREA OF LOW PRESSURE WILL DEVELOP OVER
THE MOUTH OF THE CHESAPEAKE BAY. THIS SECONDARY LOW COMBINED WITH
HIGH PRESSURE TO OUR NORTHEAST WILL ENHANCE LOW LEVEL CAD. THE 0Z
NAM BUFKIT SOUNDINGS LOOK GOOD FOR FREEZING RAIN WITH A WARM LAYER
ABOVE 2KFT...AND BELOW FREEZING TEMPS DOWN TO THE SURFACE. AS
SURFACE TEMPS DROP DUE TO THE FALLING PRECIP AND INCREASING COLD
AIR DAMMING...MOST AREAS WILL SEE AREAS OF LIGHT FREEZING RAIN
FRIDAY EVENING AND OVERNIGHT. THE EXCEPTION TO THIS WILL BE ACROSS
THE LAKE PLAIN AND THE SOUTHERN PART OF THE WYOMING VALLEY WHERE
SURFACE TEMPS WILL BE JUST ABOVE FREEZING. ICE AMOUNTS ARE NOT
EXPECTED TO BE HIGH...WITH MOST LOCATIONS GENERALLY SEEING A TENTH
OF AN INCH OR LESS FRIDAY NIGHT. THE CRITERIA FOR A FREEZING RAIN
ADVISORY IS A TRACE OF ICE SO ADVISORIES WILL LIKELY BE ISSUED FOR
MOST OF THE AREA FOR FRIDAY NIGHT. KEEP IN MIND WITH THE INCREASED
HOLIDAY TRAVEL...IT ONLY TAKES A SMALL AMOUNT OF ICE ON AREA ROADS
TO CAUSE PROBLEMS.

ON SATURDAY THE COLD AIR WILL BE STUBBORN TO LEAVE...ESPECIALLY
AREAS EAST OF 81. CASE IN POINT...THE NAM BUFKIT SOUNDING FOR KRME
NEVER GETS ABOVE FREEZING AT THE SURFACE. IN THIS SITUATION THE
HIGHER RESOLUTION OF THE NAM12 MODEL SEEMED LIKE THE BEST MODEL TO
DEPICT THE COLD AIR BEING TRAPPED NEAR THE SURFACE. FREEZING RAIN
WILL CHANGE TO PLAIN RAIN BY MID MORNING FOR MOST AREAS...WITH
FREEZING RAIN LINGERING ACROSS THE FAR EAST THROUGH AFTERNOON. ON
THE WHOLE QPF AMOUNTS LOOK LOW ACROSS MOST OF THE AREA AS WE GET
DOWNSLOPED IN THE SOUTHEAST FLOW. THIS WILL LIMIT THE ICE
POTENTIAL ACROSS MOST OF THE AREA...WITH TOTAL ICE ACCUMULATIONS
FROM FRIDAY NIGHT THROUGH SATURDAY EXPECTED TO BE A TENTH OF AN
INCH OR LESS FOR MOST OF THE CWA. THE EXCEPTION WILL BE ACROSS THE
EAST WHERE THE COMBINATION OF THE LONGER DURATION (COLDER TEMPS)
AND SOUTHEAST FLOW (UPSLOPE FLOW) MAY PRODUCE ICE AMOUNTS BETWEEN
A QUARTER AND A HALF OF AN INCH.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 348 AM...NOT A WHOLE LOT OF CHGS TO THE LONG TERM TONIGHT. PCPN
LINGERS THRU SAT NGT BFR FINALLY BEING SHOVED EAST AS DRY SLOT AHD
OF UL LOW WORKS IN. WL LKLY SEE BREAK IN PCPN AT SOME POINT DRG
THE WEEKEND ALTHO TIMING IS ALWAYS OFF. WL THEREFORE CONT WITH
CHC-LKLY POPS THRU 12Z SUN THEN BACK OFF TO LOCHC POPS DRG THE
DAY.

H5 LOW EVENTUALLY OPENS UP EARLY IN THE WEEK WITH SOME FLUCTUATION 
IN WIND DIRECTION AS WVS PASS THRU CWA. THUS WL BE HARD TO ESTABLISH 
MUCH IN THE WAY OF LK EFFECT SNOW THRU 12Z TUESDAY WHEN MAIN TROF 
PASSES TO OUR EAST. H8 TEMPS PROGGED TO DROP BLO -20C CUD SET THE 
STAGE FOR ROUND OF FAIRLY INTENSE LK EFFECT SNOW THRU END OF LONG 
TERM BFR HIPRES BUILDS IN.

TEMPS WL AVG NEAR NORMAL EARLY IN THE PD UNTIL H5 TROF MVS OUT. AFT 
MON...EXPECT COLD AIR TO FILTER IN FM CANADA WITH TEMPS EXPECTED BLO 
NORMAL THRU MID-WEEK. 

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
LOW LEVEL MOISTURE TRAPPED UNDER AN INVERSION WILL PRODUCE MVFR
CIGS THROUGH DAYBREAK AT KELM/KSYR/KRME/KAVP WITH IFR CIGS LIKELY AT KBGM
AND KITH. MODEL SOUNDINGS INDICATE THAT THE DECK MAY LOWER A BIT
TOWARD DAYBREAK. MOST OF THE STIES MENTIONED ABOVE WILL REMAIN IN
THE SAME CATEGORY. HOWEVER...ACROSS THE HIGHER TERRAIN SITES OF KITH/KBGM
LIFR CIGS ARE POSSIBLE BETWEEN 09Z AND 13Z AS THE DECK
LOWERS. ON THURSDAY, IFR/MVFR CIGS WILL BE SLOW TO IMPROVE BUT
EXPECT VFR CONDITIONS AT ALL SITES BY 18Z.

NORTHWEST WINDS AROUND 10 KNOTS THIS EVENING WILL BECOME LIGHT
LATER TONIGHT THEN N/NE ON THURSDAY AROUND 5 KNOTS.

.OUTLOOK...
THURSDAY NIGHT/FRI...VFR. 
FRI NGT...MVFR IN MIXED PRECIP. 
SATURDAY/SATURDAY NIGHT...IFR POSSIBLE IN RAIN AND SNOW.
SUN/MON...MVFR WITH AREAS OF LAKE EFFECT SNOW AT NY SITES.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...HEDEN
LONG TERM...PVN
AVIATION...HEDEN/RRM