FXUS61 KBGM 120546
AFDBGM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
1246 AM EST SAT DEC 12 2009

.SYNOPSIS...
SIGNIFICANT LAKE EFFECT SNOW WILL OCCUR ACROSS ONEIDA COUNTY
TONIGHT WITH MAINLY FLURRIES ELSEWHERE. NEAR TO SLIGHTLY BELOW
NORMAL TEMPERATURES ARE EXPECTED THROUGH SATURDAY. LAKE EFFECT
SNOWS WILL DIMINISH SATURDAY AFTERNOON...WITH THE NEXT CHANCE FOR
PRECIPITATION ON SUNDAY...IN THE FORM OF RAIN OR SNOW.

&&

.NEAR TERM /THROUGH TODAY/...
     UPDATED AS OF 10 PM... 

LAKE ERIE BAND HAS PROGRESSIVELY WEAKENED SINCE ABOUT 8 PM...AS
WAS WELL ADVERTISED BY LOCAL MODELS. FOR THE REST OF THE
NIGHT...WE JUST EXPECT SCATTERED SNOW SHOWERS AND FLURRIES OVER
THE TWIN TIERS...WITH LITTLE OR NO ADDITIONAL ACCUMULATIONS. 

THE LAKE ONTARIO BAND HAS BEEN ABOUT STEADY STATE IN NATURE THE
LAST SEVERAL HOURS...WITH THE SOUTHERN EXTENT OF THE HEAVIER SNOW
NEAR KRME...AND STAYING NORTH OF ONONDAGA...THROUGH
WESTERN/SOUTHERN OSWEGO. WE DON'T EXPECT A GREAT DEAL OF CHANGE TO
THIS SCENARIO OVERNIGHT. HEAVIER SQUALLS OVER NORTHERN/CENTRAL
ONEIDA WILL CONTINUE TO PRODUCE SIGNIFICANT ACCUMULATIONS...WITH
STORM TOTALS VERY LIKELY ECLIPSING A FOOT IN PORTIONS OF NORTHERN
ONEIDA BEFORE DAYBREAK. 

WE STILL THINK ENOUGH HEAVIER SQUALLS WILL GET TO PLACES LIKE
ROME...FLOYD...AND HOLLAND PATENT IN CENTRAL ONEIDA...TO BRING
THEM NEAR OR OVER WARNING CRITERIA BY LATER SATURDAY MORNING. 

OUTSIDE OF THE LAKE BANDS...PARTLY TO MOSTLY CLOUDY SKIES
FORESEEN...WITH JUST A FEW FLURRIES AT WORST.

BY EARLY AFTERNOON SATURDAY...A WEAKENING TREND IN THE LAKE SNOWS
SHOULD COMMENCE...AS DIRECTIONAL SHEAR INCREASES...AND THE
INVERSION LOWERS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
SHRT WV APRCHS THE AREA SAT NGT AND EXITS EARLY MON. FCST AREA
UNDER A FLAT RDG AND WITH WRMG AHD OF THE LOW PCPN TYPE IN
QUESTION. OPERATIONAL NAM REALLY THE WRMST OF THE MODELS WITH A
WIDESPREAD LGT RAIN EVENT FOR THE ENTIRE FCST AREA. ON THE COLD
SIDE IS THE 00Z ECMWF WITH A WIDESPREAD SNOW EVENT...EVEN IN NE
PA...WITH SOME CONCERNING QPF AMTS. IN THE MIDDLE FALL THE GFS
AND SREF MEAN. AS USUAL...FELT THE SAFEST BET ATTM WLD BE TO GO
WITH THE AVG OF SOLNS WHICH IS NEAR THE SREF AND GFS. THIS WLD
BRING SOME LGT SNOW FLWD BY MIXED PCPN TO MUCH OF THE FCST AREA.
ONLY XCPTN MADE WAS FOR THE XTRM NORTH WHERE AVGS GIVE ALL SNOW
FOR THE EVEN. DECIDED NOT TO BUY THE HEAVIER EURO AMTS AND WITH WITH
GNRLY LGT QPF AND SNOW ACCUMS.

NAM USES IT/S TIGHTER BAROCLINIC ZONE TO DEEPEN THE SFC LOW MORE AS
IT RCHS THE CST. THIS ALLOWS THE PCPN TO LINGER MUCH OF SUN NGT
AND EVEN INTO EARLY MON. ONCE AGAIN WENT MORE TWRD THE MEAN SOLN
AND TAPER THE PCPN AFTER DARK SUN...AND KEEP THE FCST AREA DRY ON
MON WITH WEAK RDGG. 

ATTM...DOES NOT LOOK LIKE A FLAG-ABLE EVENT BUT WILL KEEP A
MENTION IN THE HWO JUST IN CASE THE ECMWF HAPPENS TO BE ONTO
SOMETHING. IN THAT ECMWF SCENARIO...SEVERAL INCHES OF SNOW WOULD
FALL.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODEL GUIDANCE IN REASONABLY GOOD AGREEMENT THAT THE START OF THE
PERIOD WILL BE FAIRLY MILD...AHEAD OF A STRONG COLD FRONT.
SCATTERED RAIN AND SNOW SHOWERS LOOK LIKE THEY'LL PREVAIL MONDAY
NIGHT INTO TUESDAY.

ONCE THE AFOREMENTIONED FRONT CROSSES THE AREA LATER
TUESDAY...MUCH COLDER CONDITIONS WILL RETURN FOR THE BALANCE OF
THE WEEK...ALONG WITH A DAILY CHANCE FOR SNOW SHOWERS OR
FLURRIES...WITH A NORTH TO NORTHWESTERLY FLOW PATTERN.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
UPDATED 1240 AM...
BANDS OF LAKE EFFECT SNOW OFF OF ONTARIO AND ERIE WILL CAUSE
RESTRICTIONS THROUGH THE OVERNIGHT HOURS. LAKE ERIE BAND IS SLOWLY
WEAKENING AS DRIER AIR MOVES IN. MVFR CONDITIONS ARE POSSIBLE AT
ELM...ITH...AND BGM. FURTHER NORTH KSYR SHOULD STAY SOUTH OF THE
LAKE ONTARIO BAND...BUT KRME SHOULD CONTINUE TO BE IN IT. KRME HAS
VARIED FROM IFR VSBY/MVFR CIG TO MVFR VSBY/VFR CIG. SAT LATE
MORNING TO AFTN THE LOW LEVEL WILL SHIFT SO THAT THE LAKE ONTARIO
SNOW BAND WILL SHIFT NORTH AND STAY THERE ENDING THIS EVENT. KAVP
WILL STAY VFR WELL SOUTH OF ANY LAKE EFFECT PRECIP AND MOST OF THE
CLOUDS. 

WEST WINDS AT AROUND 10 KTS THIS MORNING WILL CONTINUE INTO THIS
AFTN AND SHIFT TO THE SW. TONIGHT SE TO S WINDS AT 6 KTS OR LESS.
AT SYR THIS MORNING STRONGER WINDS AT 15 WITH GUSTS INTO THE 20S. 

OUTLOOK...

SUNDAY AND SUNDAY NIGHT...IFR AND MVFR RESTRICTIONS IN MIXED
PRECIP. 

MONDAY...VFR.

MONDAY NIGHT...MVFR IN MIXED PRECIP. 

TUESDAY TO WEDNESDAY...VFR AT AVP AND MVFR IN LAKE EFFECT SNOW IN
NY. 

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THIS MORNING FOR 
     NYZ037.
     LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR 
     NYZ009.

&&

$$
SYNOPSIS...HEDEN
NEAR TERM...MLJ
SHORT TERM...DGM
LONG TERM...MLJ
AVIATION...TAC