FXUS61 KBGM 250017
AFDBGM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
717 PM EST THU DEC 24 2009

.SYNOPSIS...
HIGH PRESSURE LOCATED ACROSS EASTERN HUDSON BAY WILL CONTINUE 
TO EXTEND SOUTH TONIGHT PROVIDING DRY WEATHER ACROSS THE AREA.
MEANWHILE...A VERY STRONG STORM SYSTEM LOCATED ACROSS THE SOUTHERN
PLAINS WILL CONTINUE MOVING NORTH INTO THE UPPER MISSISSIPPI RIVER
VALLEY BY FRIDAY EVENING. A WARM FRONT ATTACHED TO THIS SYSTEM
WILL GRADUALLY PUSH NORTH...BRINGING A WINTRY MIX OF PRECIPITATION
TO MUCH OF CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA FRIDAY
AFTERNOON. A PROLONGED PERIOD OF WINTER WEATHER IS EXPECTED ACROSS
THE REGION THROUGH EARLY PORTIONS OF THE WEEKEND...WHICH WILL
MAKE HOLIDAY TRAVEL VERY HAZARDOUS. ALL WITH TRAVEL PLANS ARE
ENCOURAGED TO ALLOW EXTRA TIME TO REACH THEIR DESTINATIONS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FAIRLY QUIET WX EXPECTED INITIALLY AS A STRONG SFC RIDGE OF HIGH
PRESSURE EXTENDS SOUTH FROM EASTERN HUDSON BAY. STUBBORN LOW-LEVEL
STATUS WILL REMAIN PREVALENT ACROSS THE REGION OVERNIGHT WHICH IN
COMBINATION WITH LOW TEMP/DEW POINT SPREADS WILL PREVENT OVERNIGHT
LOWS FROM FALLING TOO MUCH. ALL PRECIPITATION IN ASSOCIATION WITH
DEVELOPING/STRENGTHENING STORM SYSTEM ACROSS THE SOUTHERN
PLAINS/LOWER MISS RVR VLY WILL REMAIN SOUTH OF THE AREA.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
A VERY COMPLICATED FORECAST IS SHAPING UP ACROSS THE REGION THIS
AFTERNOON AS A STRONG EARLY SEASON WINTER STORM CONTINUES TO
DEVELOP/STRENGTHEN ACROSS THE CENTRAL US. MID AFTERNOON WATER
VAPOR/RUC COMBO REVEALING A DEEP MERIDIONAL TROUGH EXTENDING SOUTH
TO THE WESTERN GULF OF MEXICO THIS AFTERNOON WITH A STRONG POLAR
VORTEX SPINNING ACROSS NORTHEASTERN TX. FURTHER NORTH...ANOTHER
STRONG POLAR VORTEX REMAINS POSITIONED ACROSS THE NORTHERN HIGH
PLAINS. MAIN SFC LOW OF INTEREST REMAINS CONFINED TO THE SOUTHERN
VORTEX WITH LATEST MSAS ANALYSIS SHOWING FEATURE NOW RESIDING
ACROSS WEST-CENTRAL AR. AS THE OVERNIGHT HOURS PROGRESS...THIS
OCCLUDED LOW WILL MOVE DUE NORTH INTO THE MID/UPPER MISS RVR VLY
BY 12Z FRI. AS IT DOES SO...AN OCCLUDED BOUNDARY/WARM FRONT WILL
ALSO PUSH NORTH THROUGH THE TENN/OHIO RVR VLYS WITH THIS BOUNDARY
EXPECTED TO RESIDE FROM WEST-CENTRAL IL THROUGH EASTERN TN BY 12Z
FRI. AS THE DAY PROGRESSES...SECONDARY LOW DEVELOPMENT IS
ANTICIPATED ACROSS EASTERN SC/GA WITH THIS SECONDARY FEATURE THEN 
EXPECTED TO BEGIN MOVING NORTH ALONG THE ATLANTIC SEABOARD BY FRI
EVENING. MEANWHILE TO THE NORTH...STRONG SURFACE HIGH PRESSURE IN
ASSOCIATION WITH CANADIAN HIGH PRESSURE ACROSS EASTERN HUDSON BAY
WILL SLOWLY PUSH EAST. THIS FEATURE TO THE NORTH MAKES THIS
FORECAST EXTREMELY CHALLENGING AS FOR THE PAST SEVERAL DAYS IT HAS
PROVIDING COLD BELOW AVERAGE TEMPERATURES TO THE REGION. AS THIS
SYSTEM TO THE SOUTHWEST ADVANCES NORTH...VERY WARM MOIST AIR
ORIGINATING FROM THE GULF OF MEXICO WILL OVERRIDE THE SHALLOW DOME
OF COLD AIR NEAR THE SFC...CREATING A WINTRY MIX OF PRECIPITATION
ACROSS THE AREA.

MODELS (WRF/GFS/ECMWF) ARE IN RELATIVELY GOOD AGREEMENT WITH PRECIP
BEGINNING TO OVERSPREAD THE REGION BY FRI AFTERNOON. BUFKIT
FORECAST SOUNDINGS FROM ACROSS THE REGION SHOW A WELL DEFINED WARM
WEDGE BETWEEN 900-800 MILLIBARS AS WARM AIR CONTINUES ADVECTING NORTH
INTO THE REGION. WARM WEDGE TEMPS APPROACH 3 TO 4C ACROSS SOME
LOCATIONS WHICH SUGGESTS INITIAL PRECIP WILL LIKELY BEGIN AS RAIN
BEFORE THE REMAINDER OF THE COLUMN SATURATES LATER FRI NIGHT.
WITH SFC TEMPS REMAINING AT OR BELOW 0C FRI NIGHT ACROSS MANY
AREAS...PROSPECTS FOR FREEZING RAIN AND MINOR ICE ACCUMULATIONS
ARE INCREASING. AS OF NOW...IT CURRENTLY APPEARS THE HIGHEST
LIKELIHOOD FOR ACCUMULATING ICE WILL BE CONFINED TO PORTIONS OF THE
POCONOS AND EASTERN SUSQUEHANNA VALLEY...WHERE COLD AIR WILL HAVE
THE LONGEST RESIDENCE TIME IN RESPONSE TO THE RETREATING SFC RIDGE
AXIS. ACROSS THESE LOCATIONS...ICE ACCUMULATIONS OF A QUARTER INCH
OR MORE WILL BE POSSIBLE WITH LESSER AMOUNTS EXPECTED WEST WHERE
WARMER AIR WILL EVENTUALLY HELP SCOUR OUT COLD AIR TRAPPED NEAR
THE SFC. WITH PRECIP TYPE REMAINING A BIG CHALLENGE...HAVE DECIDED
TO ISSUE A WINTER WX ADVISORY FOR MIXED PRECIPITATION...BEGINNING
FRI AFTERNOON AND RUNNING THROUGH SAT MORNING...AFTERWHICH...WARMER
AIR WILL LIKELY CHANGE ALL PRECIP TO LIQUID. HAVE FOR NOW LEFT OUT
THE CATSKILLS AS QPF AMOUNTS REMAIN IN QUESTION...AND WILL AWAIT
ONE MORE MODEL RUN BEFORE ADDING. HOLIDAY TRAVEL WILL BECOME
HAZARDOUS PORTIONS OF THE AREA BY LATE FRI AFTERNOON/NIGHT AND ALL 
TRAVELERS SHOULD ALLOW EXTRA TIME TO REACH THEIR DESTINATIONS.

BY SATURDAY...TEMPERATURES ARE EXPECTED TO REBOUND ENOUGH THAT
MOST PRECIP WILL FALL AS LIQUID. AFTER THE MAIN BAND OF PRECIP
GOES THROUGH WITH THE FRONTAL BOUNDARY...THE POSSIBILITIES EXIST
FOR LIGHT DZ AND POSSIBLY EVEN THE RETURN OF LIGHT FZRA/DZ
SAT NIGHT AS TEMPS BEGIN TO COOL ONCE AGAIN. ANY ICE ACCUMULATIONS
SHOULD REMAIN VERY LOW CONSIDERING THE LOW QPF VALUES EXPECTED.
SOUTHEASTERLY DOWNSLOPE FLOW OFF THE CATSKILLS MAY KEEP PORTIONS
OF THE EASTERN SUSQUEHANNA VALLEY/WESTERN CATSKILLS DRY SAT/SAT
NIGHT. BY SUN...MODELS ARE IN RELATIVELY GOOD AGREEMENT WITH THE
DRY TONGUE OVERSPREADING THE REGION WHICH SHOULD GIVE A TEMPORARY
REPRIEVE TO MEASURABLE PRECIP. BY LATE SUN
AFTERNOON/EVENING...PRECIP WILL BE ON THE INCREASE FROM WEST TO
EAST HOWEVER AS THE UPPER LOW BEGINS APPROACHING FROM THE WEST.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
XTNDD PD FEATURES A COLD NW FLOW AND SCT LES. ONE FEATURE OF
INTEREST IS A DIGGING WV AND LOW DVLPMT ON MON. AS USUAL...THERE
IS CNSDRBL DFRNCS IN THE TIMING AND LOCATION OF THE SFC LOW IN THE
EURO...GFS AND ENSEMBLE MEAN FCSTS...WITH THE OPERATIONAL GFS MVG
THE SFC LOW CLOSEST TO THE FCST AREA. IN ANY EVENT...ATTM IT
APPEARS THAT THE SYSTEM WILL REALLY ONLY ENHANCES THE ON GOING LES
AS THE DVLPMT OF THE LOW IS REALLY TOO LATE TO OFFER A SIGNIFICANT
WEATHER EVENT TO THE FCST AREA. 

HPC GUID WAS LOADED AS A STARTING POINT AND LGTLY ADJUSTED TO THE
LATEST THINKING.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MVFR LL CLDS LEFTOVER FROM THE EXTENDED LAKE EFFECT EVENT ARE
STILL IN KITH BUT SHOULD BE GONE BY 02Z. THEY MAY RETURN TO ELM
AND SYR BRIEFLY SINCE THEY ARE BOTH ON THE EDGE OF THE CLOUDS AS
THE CLOUDS RETREAT TO THE NW. MODELS SHOW THE LL MOISTURE
REMAINING TONIGHT BUT SATELLITE TRENDS SHOW THE CLOUDS RETREATING.
WITH THE LOW LEVEL FLOW NOW SHIFTING TO THE SE AND INCREASING
AHEAD OF THE NEXT SYSTEM...ATLANTIC MOISTURE COULD BRING MVFR
CLOUDS BACK TO THE SRN TIER AND AVP LATE TONIGHT INTO FRIDAY.
LIGHT RAIN EXPECTED AROUND 21Z FOR ELM AND AVP AND MAYBE TO ITH
AND BGM BEFORE 00Z. WITH TEMPS JUST ABOVE FREEZING THERE IS A CHC
OF FREEZING RAIN. 

E WINDS AT AROUND 5 KTS INTO FRIDAY. SLIGHTLY HIGHER WINDS AT KRME
WITH CHANNELING UP THE MOHWK VALLEY. FRIDAY E TO SE WINDS AT 5 TO
10 KTS. 

.OUTLOOK...
FRI NGT...MVFR IN MIXED PRECIP. 

SATURDAY/SATURDAY NIGHT...IFR POSSIBLE IN ICE/RAIN/SNOW.

SUN/MON/TUE...MVFR WITH AREAS OF LAKE EFFECT SNOW MOSTLY AT NY
SITES.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 4 PM FRIDAY TO 10 AM EST SATURDAY 
     FOR PAZ039-040-044-048-072.
     WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 7 AM EST SATURDAY 
     FOR PAZ038-043-047.
NY...WINTER WEATHER ADVISORY FROM 4 PM FRIDAY TO 10 AM EST SATURDAY 
     FOR NYZ025-044-045-055-056.
     WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 7 AM EST SATURDAY 
     FOR NYZ022>024.

&&

$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...DGM
AVIATION...TAC