National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS61 KBUF 120356
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1056 PM EST WED DEC 11 2013

.SYNOPSIS...
A PROLONGED PERIOD OF LAKE EFFECT SNOW...WITH OSCILLATING SNOW BANDS
OFF BOTH EASTERN GREAT LAKES WILL CONTINUE THROUGH FRIDAY. AN AREA
OF LOW PRESSURE WILL LIKELY BRING A MORE WIDESPREAD GENERAL SNOWFALL
THIS WEEKEND. EXPECT TEMPERATURES TO REMAIN BELOW NORMAL THROUGH THE
WEEKEND AS WELL. OTHERWISE...TEMPERATURES WILL REMAIN BELOW AVERAGE
THROUGH AT LEAST THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
A FRONTAL BOUNDARY DROPPING ACROSS THE REGION THIS EVENING...WHICH HAS
SHIFTED WINDS TO THE NW IN MOST LOCATIONS. THIS HAS CAUSED LAKE
EFFECT SNOWS OFF LAKE ERIE TO WEAKEN SIGNIFICANTLY. LAKE SNOWS OFF
LAKE ONTARIO REMAIN A BIT BETTER ORGANIZED...WITH THE BAND
FOCUSING ON SOUTHERN OSWEGO AND NORTHERN CAYUGA COUNTIES. A
FURTHER SOUTHWARD SHIFT IN THE BAND IS EXPECTED OVER THE NEXT
COUPLE HOURS.

OFF LAKE ERIE...

INTENSE LAKE SNOWS HAVE ENDED...WITH ONLY MODERATE LAKE EFFECT
SNOWS STILL LINGERING ACROSS HIGHER TERRAIN. THE KEY TO THIS HAS
BEEN A WIND SHIFT TO THE NORTHWEST. EXPECT MOISTURE WILL REPLENISH
TO SOME DEGREE LATE THIS EVENING...WITH MODEST LAKE EFFECT BANDS
RE-DEVELOPING ACROSS THE CHAUTAUQUA RIDGE AND HIGHER TERRAIN. THIS
MAY BRING A FEW MORE INCHES TO SOME LOCATIONS...HOWEVER THE WORST
APPEARS TO BE OVER FOR NOW.

BY TOMORROW HIGH PRESSURE FROM MID MISSISSIPPI VALLEY WILL BEGIN
TO EDGE INTO REGION AND WINDS WILL BEGIN TO BACK SOME. THIS WILL
SET UP A WSW FLOW...NOT THAT DIFFERENT FROM THE FLOW WE HAD TODAY.
CONDITIONS TOMORROW WILL BE A BIT LESS FAVORABLE...GIVEN SLIGHTLY
DRIER AIR...AND SOME WIND SHEAR. HOWEVER WITH TEMPERATURES ALOFT
JUST AS COLD...AND A LONG FETCH DOWN LAKE ERIE...EXPECT A LAKE
EFFECT BAND WILL RE-DEVELOP LATE MORNING. THIS WILL LIKELY FOCUS
ON WYOMING AND SOUTHERN ERIE COUNTIES...WHILE CLIPPING NORTHERN
PORTIONS OF CHAUTAUQUA AND CATTARAUGUS COUNTIES. DEPENDING ON HOW
WELL THIS BAND DEVELOPS...THIS COULD BRING ANOTHER ROUND OF HEAVY
SNOWFALL. BECAUSE OF THIS...A LAKE EFFECT SNOW WATCH HAS BEEN
ISSUED FOR THURSDAY MORNING THROUGH FRIDAY AFTERNOON.
WHILE THIS BAND WILL PROBABLY STAY SOUTH OF DOWNTOWN BUFFALO...IT
IS POSSIBLE PARTS OF NORTHERN ERIE COUNTY AND GENESEE COUNTY MAY
ALSO SEE SOME ACCUMULATING SNOW...DEPENDING ON WHERE THE BAND
SETS UP.

OFF LAKE ONTARIO...

LAKE EFFECT SNOWS WILL CONTINUE TO SHIFT TO THE SOUTH...FOCUSING
ON NORTHERN WAYNE/CAYUGA AND SOUTHERN OSWEGO COUNTIES. THE BAND
WILL NOT BE AS INTENSE AS BEFORE...WITH LESS MOISTURE AND LESS
UPSLOPING...HOWEVER SNOW WILL STILL BE HEAVY WITH SNOWFALL RATES
OF 1 TO 2 INCHES AN HOUR.

FORECAST CONFIDENCE DECREASES LATER TONIGHT...AS WINDS DIMINISH. MESO
SCALE MODELS...INCLUDING THE 12Z 1.3KM NAM HIGH RES WITH SOME
HINTS FROM THE OPERATIONAL 12Z 12KM NAM MODEL SUGGEST THE
FORMATION OF A MESO LOW OVER THE EASTERN END OF LAKE ONTARIO. THIS
LOW WILL LIKELY DISRUPT THE GEORGIAN BAY CONNECTION...AND FOCUS
SNOWS ALONG THE SHORELINE LATE OVERNIGHT AND THEN NORTHWARD
TOWARDS THE EASTERN LAKE ONTARIO SHORELINE TOMORROW AND INLAND
THROUGH THE LATER MORNING HOURS. HOW FAR SNOW MAKES IT INLAND WILL
DEPEND ON WIND SPEED...AND SUBTLE MOVEMENTS OF THE POTENTIAL MESO
LOW. BECAUSE OF THIS...CONFIDENCE IN PLACEMENT OF THE LAKE EFFECT
BAND WILL BE LOW LATE TONIGHT AND INTO THURSDAY MORNING. AFTER
THIS...A 260 FLOW WILL DEVELOP THURSDAY WHICH WILL PUSH LAKE
MOISTURE EAST OF LAKE ONTARIO. EVENTUALLY THIS WILL PROMOTE A
SINGLE BAND OF LAKE SNOWS ORIENTED AT THE TUG HILL REGION. THIS
MAY BRING ADDITIONAL WARNING CRITERIA SNOWS TO THIS REGION...AND
FOR NOW WILL COVER THIS POTENTIAL WITH A LAKE EFFECT SNOW WATCH.

OUTSIDE THESE LAKE BANDS. WITH THE PASSAGE OF THE SHORTWAVE IN THE
MID LEVELS WILL MAINTAIN SCATTERED FLURRIES AND LIGHT SNOW SHOWERS
THROUGH THE OVERNIGHT.

TEMPERATURES TONIGHT AND TOMORROW WILL CONTINUE TO AVERAGE BELOW
NORMAL...WITH LOWS TONIGHT IN THE LOW TEENS TO SINGLE
DIGITS...AND POSSIBLY BELOW ZERO ACROSS PORTIONS OF THE NORTH
COUNTRY WITH A LITTLE CLEARING LATE OVERNIGHT. HIGHS TOMORROW WILL
LIKELY ONLY REBOUND TO THE UPPER TEENS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
LAKE EFFECT SNOWS WILL CONTINUE THROUGH MUCH OF THE FORECAST PERIOD
AS COLD WESTERLY FLOW WILL PERSIST ACROSS THE LAKES...ALBEIT WITH
VARIATIONS IN LOCATION AND INTENSITY RELATED TO FLUCTUATIONS IN THE
UPPER LEVEL PATTERN ACROSS THE REGION. LAKE EFFECT SNOWS SHOULD WIND
DOWN TOWARDS THE END OF THE PERIOD...JUST IN TIME FOR A POTENTIALLY
SIGNIFICANT SYNOPTIC SNOWSTORM TO IMPACT THE REGION THIS WEEKEND.

AS WE OPEN THE PERIOD THURSDAY MORNING...A MODERATE TO HEAVY LES
BAND IMPACTING AREAS SOUTHEAST OF LAKE ONTARIO IS EXPECTED TO LIFT
BACK ACROSS THE TUG HILL PLATEAU THROUGH THE MORNING HOURS AS
BOUNDARY LAYER FLOW BACKS TO 260 DEGREES FROM THE 310 DEGREE FLOW
BEING EXPERIENCED WED NIGHT IN RESPONSE TO THE APPROACH OF YET
ANOTHER MID/UPPER LEVEL SHORTWAVE TROUGH AND AN ASSOCIATED WEAK
SURFACE CLIPPER LOW THAT IS PROGGED TO TRACK ACROSS ONTARIO PROVINCE
AND INTO QUEBEC THURSDAY INTO THURSDAY NIGHT. THE BACKING WINDS WILL
ONCE AGAIN INCREASE FETCH DOWN THE LAKE AND THIS COMBINED WITH THE
CYCLONIC LOW LEVEL FLOW AND A GENERAL INCREASE IN SYNOPTIC MOISTURE
ACROSS THE REGION SHOULD SET THE STAGE FOR ANOTHER PERIOD OF HEAVY
SNOWFALL ACROSS THE TUG FROM THURSDAY AFTERNOON THROUGH THURSDAY
NIGHT. INDEED THE PIPELINE WILL NOT LIKELY BE TURNED OFF UNTIL
SOMETIME IN THE MIDDLE OF THE DAY ON FRIDAY WHEN FLOW VEERS TO THE
NORTH WITH THE PASSAGE OF THE CLIPPER AND BUILDING ARCTIC HIGH
PRESSURE TO OUR NORTH ACROSS THE CANADIAN SHIELD. CURRENTLY LES
WARNINGS FOR EAST OF LAKE ONTARIO ONLY RUN OUT THROUGH THURSDAY
MORNING...BUT IT IS QUITE LIKELY THAT THESE WILL NEED TO BE EXTENDED
TO COVER THIS ADDITIONAL BURST OF SNOW.

AS THE REMNANTS OF THE AFOREMENTIONED LAKE ONTARIO BAND GET PUSHED ON
TO THE SOUTH SHORE OF THE LAKE...WE MAY SEE A BRIEF SHOT OF LAKE
EFFECT SNOWS ALONG VIRTUALLY THE LENGTH OF THE LAKE ONTARIO
SHORELINE FRIDAY AFTERNOON INTO EARLY FRIDAY EVENING...HOWEVER OF
GREATER CONCERN FRIDAY NIGHT WILL BE THE DEVELOPMENT OF A
LOW/MID-LEVEL DEFORMATION ZONE ACROSS THE LOWER GREAT LAKES AS THE
REGION WILL BE SANDWICHED BETWEEN ARCTIC HIGH PRESSURE OVER THE
CANADIAN SHIELD AND A LARGE LOW PRESSURE SYSTEM DEVELOPING OVER THE
MISSISSIPPI/OHIO VALLEYS.

AS FOR WESTERN NEW YORK...LAKE EFFECT SNOWS ARE ALSO EXPECTED TO
CONTINUE THROUGH A GOOD PORTION OF THE PERIOD. ALTHOUGH ACTIVITY
WILL LIKELY BE DISORGANIZED TO START THURSDAY MORNING WITH SHORTWAVE
RIDGE OVERHEAD...ACTIVITY SHOULD RAMP UP ACROSS THE CHAUTAUQUA RIDGE
THURSDAY AFTERNOON AS FLOW TAKES ON A MORE WESTERLY COMPONENT WITH
BANDS POSSIBLY MAKING IT UP INTO THE BUFFALO METRO BY THURSDAY
EVENING AS FLOW BACKS TO 240-250 DEGREES IN RESPONSE TO THE
AFOREMENTIONED CLIPPER. DEPENDING HOW LONG THE BAND LINGERS ACROSS
THE AREA...ANOTHER ADVISORY MAY BE NEEDED FOR THURSDAY EVENING FOR
NORTHERN ERIE/GENESEE COUNTIES...

AGAIN...AS WITH LAKE ONTARIO...FLOW WILL VEER WESTERLY AND
EVENTUALLY NORTHEASTERLY FRIDAY EVENING AS THE CLIPPER DEPARTS THE
PICTURE...PUSHING LES BANDS AROUND ACCORDINGLY BEFORE EVENTUALLY
TRANSITIONING OVER TO MORE WIDESPREAD LIGHT SYNOPTIC SNOW.

REGARDING TEMPERATURES...THURSDAY WILL BE QUITE COLD AS WE WILL
REMAIN SOLIDLY UNDER THE INFLUENCE OF UPPER LEVEL TROUGHING AND
ASSOCIATED COLD AIR WITH HIGHS NOT EXPECTED TO CLIMB OUT THE TEENS
ACROSS MOST AREAS WITH THE EXCEPTION OF AREAS NEAR THE LAKESHORES
WHERE THE MERCURY MIGHT JUST CRACK 20 DEGREES. OF COURSE...FACTORING
IN THE PERSISTENT BREEZY CONDITIONS...WIND CHILLS WILL RUN FROM THE
SINGLE DIGITS ABOVE TO THE SINGLE DIGITS BELOW ZERO. TEENS TO SINGLE
DIGITS CAN BE EXPECTED THURSDAY NIGHT. BY FRIDAY WE BEGIN TO SEE THE
BEGINNINGS OF A MODEST WARMING TREND WITH THE PASSAGE OF THE CLIPPER
AND THE BEGINNINGS OF A WARM ADVECTION PATTERN AHEAD OF DEVELOPING
LOW PRESSURE ACROSS THE MISSISSIPPI VALLEY. THIS SHOULD AT LEAST
ALLOW TEMPERATURES TO CLIMB BACK INTO THE 20S FRIDAY WITH MID TO
UPPER TEENS FRIDAY NIGHT.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
OVERALL MEDIUM RANGE MODEL TREND IS FOR THE DEVELOPING ROCKIES
DURING THE MID WEEK PERIOD TO TRAVEL INTO THE GULF COASTAL REGION
EARLY IN THE PERIOD...BEFORE MAKING A TURN TO THE NORTH TOWARD THE
LOWER GREAT LAKES/NORTHEAST CONUS DURING THE WEEKEND. MODELS SEEM TO
BE CONVERGING AT A HIGHER PROBABILITY OF PRECIPITATION IMPACTING
WESTERN AND CENTRAL NEW YORK DURING THIS TIME FRAME...ESPECIALLY
LATER SATURDAY AND SUNDAY...AS LOW PRESSURE APPROACHES FROM THE OHIO
VALLEY. LATEST GFS/ECMWF INDICATING TWO ENTERS OF LOW PRESSURE...ONE
WORKING THROUGH THE EASTERN LAKES WITH THE MORE SIGNIFICANT LOW
MOVING UP ALONG THE EAST COAST. SOME UNCERTAINTY ON HOW ALL THIS
WILL PLAY OUT...BUT THE SUGGESTION IS THAT A WIDESPREAD SNOW EVENT
WILL DEVELOP SATURDAY THROUGH SUNDAY...WITH PERHAPS SOME WINTRY MIX
OCCURRING ACROSS THE SOUTHEASTERN PORTION OF THE AREA AS SOME WARMER
AIR WRAPS INTO THE SYSTEM. MUCH TOO EARLY IN THE GAME TO PINPOINT
SNOWFALL AMOUNTS...BY THE POTENTIAL DOES EXIST FOR AT LEAST SEVERAL
INCHES.

ONCE THE SYSTEM LIFTS OFF TO THE NORTH...ARCTIC AIR WILL ONCE AGAIN
SURGE INTO THE REGION...WITH THE POTENTIAL FOR LAKE SNOWS
REDEVELOPING ON A NORTHWEST FLOW...WITH THE BEST POTENTIAL FOR THE
MOST SIGNIFICANT LAKE SNOW FROM SUNDAY NIGHT INTO EARLY MONDAY. HIGH
PRESSURE RIDGING ACROSS THE REGION LATE MONDAY SHOULD DIMINISH LAKE
POTENTIAL. NEXT CLIPPER LOW LOOKS TO APPROACH THE GREAT LAKES
TUESDAY.

&&

.AVIATION /04Z THURSDAY THROUGH MONDAY/...
LAKE EFFECT SNOW BANDS EAST OF LAKES ERIE AND ONTARIO ARE BECOMING
SLIGHTLY MORE NORTHWEST TO SOUTHEASTERLY...ESPECIALLY OFF LAKE
ONTARIO. THIS WILL DIRECT THE LAKE SNOWS INTO THE KJHW LOCALE WITH
LOWER MVFR OR IFR CONDITIONS THROUGH THE NIGHT...AND MAY BRUSH
KROC BETWEEN 04Z AND 08Z WITH LOWER MVFR CONDITIONS.

A WEST TO SLIGHTLY SOUTHWESTERLY REORIENTATION OF THE BOUNDARY
LAYER WINDS AND ASSOCIATED LAKE EFFECT SNOW BANDS MAY BRING IFR
CONDITIONS BACK TO KBUF DURING THURSDAY AFTERNOON AND
EVENING...MAINLY 21Z THROUGH 01Z...AND MORE ESPECIALLY TO KART
FROM 17Z ONWARD AND HEAVIER SNOW WITH LIFR POSSIBLE AFTER 00Z
FRIDAY.

OUTLOOK...
THURSDAY AFTERNOON AND FRIDAY...MAINLY VFR...EXCEPT IFR IN LAKE
EFFECT SNOW SHOWERS EAST OF THE LAKES.
SATURDAY AND SUNDAY...MVFR/IFR WITH SNOW LIKELY.
MONDAY...MVFR WITH A CHANCE FOR SNOW SHOWERS.

&&

.MARINE...
WITH A DEEP POOL OF COLD AIR OVER THE EASTERN GREAT LAKES RIGHT INTO
THE WEEKEND...AND PASSAGE OF SEVERAL SURFACE WAVES/LOW PRESSURES
ACROSS THE GREAT LAKES SOLID ADVISORY-LEVEL CONDITIONS WILL PERSIST
THROUGH THE END OF THE WEEK.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW WATCH FROM 10 AM EST THURSDAY THROUGH FRIDAY
     AFTERNOON FOR NYZ007-008.
     LAKE EFFECT SNOW WARNING UNTIL 4 PM EST FRIDAY FOR NYZ006.
     LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THURSDAY FOR NYZ005.
     LAKE EFFECT SNOW WARNING UNTIL 10 AM EST THURSDAY FOR NYZ004.
     LAKE EFFECT SNOW WATCH FROM 10 AM EST THURSDAY THROUGH FRIDAY
     AFTERNOON FOR NYZ012-019-020-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LEZ040-041.
         SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR
         LOZ030.
         SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LOZ042>045.

&&

$$

SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...APFFEL/TMA
LONG TERM...TMA
AVIATION...WCH
MARINE...APFFEL/THOMAS