FXUS61 KBUF 102331
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
631 PM EST THU DEC 10 2009

.SYNOPSIS...
THE MAJOR STORM SYSTEM THAT AFFECTED MORE THAN HALF OF THE NATION 
WAS CONTINUING TO WITHDRAW NORTHEAST FROM QUEBEC THIS AFTERNOON AND 
IT WILL CONTINUE TO SLOWLY LOSE ITS GRIP ON OUR AREA IN TERMS OF 
WINDS SPEEDS DURING THE NEXT COUPLE OF DAYS. UNFORTUNATELY THOUGH 
THE COLD WEST NORTHWEST FLOW WILL CONTINUE TO PRODUCE BANDS OF 
SIGNIFICANT LAKE EFFECT SNOW RIGHT INTO SATURDAY. THE AREAS THAT 
WILL BE MOST FAVORED WILL BE THE TRADITIONAL SNOW BELTS EAST 
SOUTHEAST OF BOTH LAKES.

&&

.NEAR TERM /THROUGH FRIDAY/...
...630 PM UPDATE...
INTENSE BAND OFF LAKE ERIE HAS MOVED LITTLE THE PAST HOUR...BUT
SHOULD RESUME A SOUTHWARD DRIFT AFTER 8 PM PER RADAR SIGNATURES
OFF ERIE PA AS SHORT WAVE PASSES. THIS BAND NOW HUGGING THE
LAKESHORE FROM DUNKIRK TO ANGOLA...WITH VERY DISTINCT NORTHERN
EDGE FROM NEAR RALPH WILSON STADIUM TO ALDEN TO BATAVIA TO
HENRIETTA. SNOWFALL RATES OF 1-2 INCHES PER HOUR WITHIN THIS BAND.
GRIDS HAVE THIS WELL HANDLED. ALSO A PESKY SECOND BAND DEVELOPING
ALONG NORTH SHORE OF LK ERIE BUT APPEARS TO BE JUST CELLULAR AND
WILL STAY JUST SOUTH OF BUF. OFF ONTARIO...INTENSE BAND JUST
PASSED SOUTH OF WATERTOWN AND WILL CENTER OVER CNTRL JEFF AND NRN
LEWIS COS. THIS WILL STA IN PLACE WITH PRODIGIOUS AMTS OVER TUG
HILL.

DID TWEAK GRIDS TO ACCOUNT FOR COLDER TEMPS. WILL MAINTAIN ALL
FLAGS AT THIS TIME. ERIE ACTIVITY HAS WEAKENED OVER SRN MONROE
BUT WILL HOLD ONTO WRNG TILL 03Z DUE TO BLOWING SNOW AND HAZARDOUS
CONDITIONS. A RARE THING FOR LK ERIE TO CAUSE SO MUCH SNOW IN
METRO ROCHESTER. PREV DISC FOLLOWS...

INTENSE LAKE SNOWS WILL BE THE BIG STORY THROUGH THE NEAR TERM
PERIOD.

FROM A SYNOPTIC STANDPOINT...DEEP LOW PRESSURE WILL CONTINUE TO MOVE 
OUT INTO THE CANADIAN MARITIMES TONIGHT...WITH DEEP/MOIST CYCLONIC 
FLOW CONTINUING OVER THE GREAT LAKES REGION THROUGH THE PERIOD. 
OUTSIDE OF LAKE EFFECT AREAS...EXPECT AN AREA OF SNOW SHOWERS TO 
MOVE THROUGH THE INTERIOR SOUTHERN TIER THROUGH THIS EVENING WITH AN 
INCH OR LESS ACCUMULATION. THIS SHOULD TAPER OFF LATER THIS EVENING 
WITH LOSS OF DAYTIME HEATING. ACROSS THE SAINT LAWRENCE VALLEY... 
SCATTERED SNOW SHOWERS WILL CONTINUE THROUGH FRIDAY...AND THIS ARE 
MAY OCCASIONALLY SEE BATCHES OF MORE CONCENTRATED SNOW SHOWERS MOVE 
THROUGH AS AN EASTWARD EXTENSION OF GEORGIAN BAY LAKE EFFECT SNOW.

OFF LAKE ERIE...
BY LATER THIS EVENING THE BAND SHOULD SETTLE SOUTHWARD INTO THE
MORE DISTANT SOUTH TOWNS EAST INTO WYOMING COUNTY AS A 700MB
SHORTWAVE PASSES THROUGH THE REGION AND VEERS THE WINDS MORE
WESTERLY. FINALLY OVERNIGHT...EXPECT THE BAND TO SETTLE INTO THE
MORE TRADITIONAL SKI COUNTRY SNOWBELT...FOCUSING ON THE BOSTON
HILLS EAST TO WYOMING COUNTY AND ALSO THE NORTHERN SECTIONS OF
CHAUTAUQUA AND CATTARAUGUS COUNTY. DURING THE DAY FRIDAY EXPECT
THE LAKE SNOWS TO REMAIN IN THIS GENERAL AREA...ALTHOUGH THERE MAY
BE A SLIGHT NORTHWARD DRIFT IN THE AFTERNOON WHICH COULD PULL THE
BAND MORE INTO SOUTHERN ERIE COUNTY AND OUT OF THE SOUTHERN TIER
COUNTIES.

EXPECT SNOWFALL RATES OF 1-2 INCHES PER HOUR IN THE MOST INTENSE 
PORTION OF THIS BAND THROUGH TONIGHT...WITH PERHAPS SOME WEAKENING 
TO AROUND 1 INCH PER HOUR ON FRIDAY. STORM TOTALS WILL BE UP TO 18
INCHES IN THE BUFFALO SOUTH TOWNS...WITH 3 TO 6 INCHES ACROSS THE
CITY FROM NORTH TO SOUTH...2-3 FEET IN THE BOSTON HILLS. EXPECT
1-2 FEET IN THE NORTHERN REACHES OF CHAU/CATT COUNTIES.

OFF LAKE ONTARIO...
THE BAND WILL SETTLE SOUTH ACROSS THE CENTRAL TUG HILL REGION
OVERNIGHT INTO FRIDAY MORNING. LATER FRIDAY MORNING THE BAND MAY
SETTLE INTO THE CENTRAL PORTION OF OSWEGO COUNTY AND THE SOUTHERN
PORTION OF THE TUG...BEFORE LIFTING BACK NORTH INTO THE CENTRAL
PORTION OF THE TUG BY LATE IN THE DAY.

EXPECT SNOWFALL RATES OF 1-2 INCHES TO BE COMMON IN THIS BAND WITH 
2-3 INCHES POSSIBLE ON THE TUG HILL. HAVE INCREASED ACCUMS ON THE 
TUG FOR BOTH TONIGHT AND FRIDAY...WITH UP TO 2 FEET TONIGHT AND 
ANOTHER 2 FEET ON FRIDAY ON THE CENTRAL PORTION OF THE TUG. EXPECT 
THE HARDEST HIT AREAS TO BE FROM REDFIELD TO NORTH OSCEOLA AND 
MONTAGUE. STORM TOTALS ARE LIKELY TO EXCEED 4 FEET ON THE TUG... 
WITH 1 TO 2 FEET IN THE LOWER ELEVATIONS IN THE NORTHERN HALF OF 
OSWEGO...SOUTHERN HALF OF JEFFERSON...AND MUCH OF LEWIS COUNTY.

WINDS...
A WIND ADVISORY WILL CONTINUE THROUGH 4 AM FRIDAY. WIND GUSTS TODAY 
HAVE BEEN IN THE 40-50 MPH RANGE...WITH THE STRONGEST WINDS DOWNWIND 
OF LAKE ERIE AND LAKE ONTARIO. EXPECT GUSTS TO CONTINUE IN THIS 
RANGE MUCH OF TONIGHT...AND MODELS SUGGEST GUSTS MAY ACTUALLY PICK 
UP A LITTLE THROUGH THE FIRST HALF OF TONIGHT. IT WILL STILL BE 
WINDY FRIDAY...BUT WINDS SHOULD COME DOWN TO BELOW ADVISORY CRITERIA 
WITH GUSTS IN THE 35-40 MPH RANGE.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
THE AFFECTS OF THE VERY COLD AIR MASS IN THE WAKE OF WEDNESDAY'S 
STORM WILL CONTINUE ACROSS PARTS OF THE AREA FRIDAY NIGHT. MUCH OF 
THE AREA WILL SEE NO MORE SNOW BUT LAKE EFFECT ACTIVITY WILL  
PERSIST OVER PARTS OF SOUTHERN ERIE...WYOMING AND THE NORTHERN 
SECTIONS OF CHAUTAUQUA AND CATTARAUGUS COUNTIES OFF LAKE ERIE AND 
ACROSS THE TUG HILL AREA AND MUCH OF OSWEGO COUNTY OFF LAKE 
ONTARIO.

WE FINALLY EXPECT SLOW IMPROVEMENT SATURDAY AS THE FLOW WEAKENS IN 
RESPONSE TO HIGH PRESSURE ADVANCING FROM THE SOUTHWEST. THE LAKE 
ERIE ACTIVITY WILL LIKELY END IN THE AFTERNOON AND THE LAKE ONTARIO 
ACTIVITY WILL WEAKEN. SATURDAY NIGHT LOOKS TO BE QUIET BUT COLD AS 
THE HIGH CRESTS OVER US.

BY SUNDAY WARM ADVECTION WILL BEGIN BUT WITH IT WILL COME ENOUGH 
LIFT TO HAVE CHANCE POPS. TEMPERATURES WILL BE MARGINAL FOR RAIN OR 
SNOW SO WE WILL CARRY EITHER OR AT THIS TIME. LOOKS LIKE THE CHANCE 
WILL END BY SUNDAY NIGHT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
THIS PERIOD WILL START OUT RATHER BENIGN WITH A RIDGE OF HIGH 
PRESSURE CRESTING OVER US MONDAY MORNING. WE EXPECT FAIR WEATHER AND 
HIGHS OVER 40 IN MOST AREAS DURING THE DAY.

A VERY COLD AIR MASS OVER CENTRAL CANADA IS THEN EXPECTED TO CARVE 
OUT AN UPPER AIR TROUGH WHICH IS FORECAST TO SWING INTO QUEBEC 
TUESDAY. THE ASSOCIATED SURFACE LOW AND COLD FRONT WILL MOVE INTO 
THE LOWER REGION MONDAY NIGHT WITH THE COLD FRONT SCHEDULED TO MOVE 
THROUGH EARLY TUESDAY. 850 MB AND SURFACE TEMPERATURES ARE MARGINAL. 
AT THIS POINT WE WILL CARRY A CHANCE OF RAIN OR SNOW SHOWERS MONDAY 
NIGHT AND TUESDAY. FREEZING PRECIPITATION IS NOT OUT OF THE QUESTION 
BUT THAT WILL BE REFINED IN LATER FORECASTS. 

STRONG COLD ADVECTION IS EXPECTED ON THE BACK SIDE OF THE ABOVE 
MENTIONED SYSTEM WITH 850 MB TEMPERATURES EXPECTED TO PLUNGE TO 
MINUS 16 TO MINUS 20C. THE NORTHWEST FLOW WILL FAVOR AREAS SOUTHEAST 
OF THE LAKES. WE WILL GO LIKELY POPS FOR LAKE EFFECT SNOW IN THOSE 
AREAS FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A CHANCE OF SNOW 
SHOWERS ELSEWHERE.  

BY THURSDAY THE COLD AIR MASS WILL REMAIN IN PLACE. WE WILL KEEP AT 
LEAST A CHANCE OF SNOW SHOWERS IN THE FORECAST FOR AREAS SOUTHEAST 
OF THE LAKES.

HIGHS ON WEDNESDAY AND THURSDAY WILL BE NO BETTER THAN THE 20S.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/... LAKE EFFECT SNOW WILL
CONTINUE TO DOMINATE THE WEATHER THROUGH THE FORECAST PERIOD.

THE INTENSE BAND OFF LAKE ERIE...WILL REMAIN SOUTH OF THE KBUF TERMINAL.
AS THE STEERING WINDS VEER MORE TO THE WEST TONIGHT AND
FRIDAY...THE STEADIEST SNOW WILL SET UP ACROSS THE SOUTHERN
TIER...IMPACTING KJHW. EXPECT IFR TO LIFR CONDITIONS WITHIN THE
MAIN SNOW BAND...BUT AREAS TO THE NORTH...INCLUDING KIAG AND
KROC...WILL SEE MAINLY VFR CONDITIONS.

OFF LAKE ONTARIO...THE HEAVIEST SNOW IS EXPECTED TO STAY MAINLY 
SOUTH OF KART...BUT THE PROXIMITY OF THE MAIN SNOW BAND WILL STILL 
KEEP IFR CONDITIONS AT KART UNTIL ABOUT 06Z. TOWARD DAYBREAK AND 
THROUGH FRIDAY MORNING...EXPECT CONDITIONS VCNTY KART TO IMPROVE TO 
VFR AS THE SNOW SETTLES SOUTH OVER THE TUG HILL PLATEAU.

THE PRESSURE GRADIENT BETWEEN LOW PRESSURE OVER QUEBEC AND HIGH 
PRESSURE OVER THE PLAINS STATES WILL KEEP SURFACE WINDS IN THE 20 TO 
30 KNOT RANGE THROUGH THE FORECAST PERIOD. 

OUTLOOK...
FRIDAY...VARIABLE CONDITIONS...LARGELY VFR...BUT IFR/LIFR IN LAKE
EFFECT SNOW SHOWERS. 
SATURDAY...VFR/MVFR IN SNOW SHOWERS. 
SUNDAY AND MONDAY...VFR.
TUESDAY...MAINLY VFR CHANCE -RW/-SW.

&&

.MARINE...
ALL WARNINGS ARE BACK TO GALES AT THIS TIME. THE DEEP LOW 
WITHDRAWING FROM QUEBEC WILL CONTINUE TO PRODUCE STRONG ENOUGH WINDS 
TO PRODUCE ROUGH CONDITIONS AT LEAST THROUGH FRIDAY. GALES WILL BE
LOWERED TO SMALL CRAFTS ON THE ST. LAWRENCE RIVER AND BUFFALO
HARBOR AT 00Z THIS EVENING. 

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY UNTIL 4 AM EST FRIDAY FOR NYZ001>008-010>014-
     019>021-085.
     LAKE EFFECT SNOW WARNING UNTIL 7 AM EST SATURDAY FOR NYZ012-
     019-020-085.
     LAKE EFFECT SNOW WARNING UNTIL 1 PM EST SATURDAY FOR 
     NYZ006>008.
     LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR 
     NYZ003-010-011.
     LAKE EFFECT SNOW WARNING UNTIL 7 AM EST FRIDAY FOR NYZ013.
     LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST FRIDAY FOR NYZ014.
MARINE...GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LEZ020.
         GALE WARNING UNTIL 1 PM EST FRIDAY FOR LEZ040-041.
         GALE WARNING UNTIL 10 PM EST FRIDAY FOR LOZ042>045-
         062>065.
         GALE WARNING UNTIL 7 PM EST THIS EVENING FOR SLZ022-
         024.

&&

$$

SYNOPSIS...SAGE
NEAR TERM...HITCHCOCK/SFM
SHORT TERM...SAGE
LONG TERM...SAGE
AVIATION...SFM/TJP
MARINE...SAGE/SFM/JJP