National Weather Service National Headquarters

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

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBUF 100436
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1136 PM EST TUE FEB 9 2010

.SYNOPSIS...
LOW PRESSURE WILL ADVANCE NORTHEAST INTO THE OHIO VALLEY EARLY
TONIGHT...REACHING NORTHEAST OHIO OVERNIGHT AND THEN TRANSFER ITS
ENERGY TO A RAPIDLY DEEPENING LOW ALONG THE DELMARVA COAST BY
WEDNESDAY MORNING. THE COASTAL LOW WILL CONTINUE TO STRENGTHEN AS
IT MOVES OFF THE EAST COAST THROUGH WEDNESDAY NIGHT. THIS SYSTEM
WILL BRING ACCUMULATING SNOW TO THE REGION WITH THE SOUTHERN TIER
RECEIVING THE MOST SNOWFALL...WITH LESSER AMOUNTS OCCURRING ACROSS
THE NORTH COUNTRY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THROUGH 900 PM...OVERALL SYSTEM STILL PROGRESSING AS
EXPECTED...WITH THE INITIAL BAND SPREADING JUST NORTH AND EAST OF
ROCHESTER...WEAKENING AS IT PUSHES NORTH. BUFKIT AND UPPER AIR
ANALYSIS SHOW THE PRIMARY DRIVER OF THIS IS ACTUALLY LIFT IN THE
UPPER LEVELS ASSOCIATED WITH DIFLUENCE 500 TO 300 MB...WITH A
SECONDARY FACTOR WEAK WARM AIR ADVECTION IN THE LOW- MID LAYERS.
FOLLOWING MANY OF THE 18Z MODELS...THERE IS A BREAK BETWEEN THIS
LEADING EDGE...AND STEADIER SNOWFALL WHICH IS STILL ACROSS
NORTHEASTERN OHIO.

THE NEXT WAVE WILL ENTER FAR WESTERN NEW YORK JUST SHY OF
MIDNIGHT...SPREADING INTO THE WESTERN THIRD OF NEW YORK BY
DAYBREAK. PERHAPS THE TRICKIEST PART OF THE FORECAST IS THE
NORTHWARD EXTENT...WITH RADAR SUGGESTING A HEDGE ON THE MORE
NORTHWARD SOLUTIONS...WHICH IS IN LINE WITH GOING FORECAST.
OVERALL...SEE NO REASON FOR SIGNIFICANT CHANGES TO THE FORECAST.
UPDATE REFLECTS MAINLY WORDING CHANGES AS THE SNOW BANDS
PROGRESS...WITH LITTLE TO NO ADJUSTMENT TO OVERNIGHT SNOW
ACCUMULATIONS. SNOWFALL RATES ARE NOT EXPECTED TO BE TERRIBLY
HEAVY...LESS THAN AN INCH AN HOUR...BUT DO EXPECT SOME
ACCUMULATION IN THE ADVISORY AREA PRIOR TO THE WEDNESDAY MORNING
RUSH HOUR...WHICH WILL LIKELY HINDER TRAVEL.

PREVIOUS DISCUSSION...

WITH REGARD TO SYNOPTIC SCALE FEATURES...A POTENT UPPER LOW
CURRENTLY NEAR ST LOUIS AS OF MID AFTERNOON WILL TRACK EAST
DURING THE NEAR TERM PERIOD...REACHING WEST VIRGINIA BY LATE TONIGHT
BEFORE MOVING OFF THE MID ATLANTIC COAST DURING THE COURSE OF
WEDNESDAY. AN ASSOCIATED PRIMARY SURFACE LOW WILL CONTINUE TO LIFT
NORTH FROM THE OHIO VALLEY TO A POSITION NEAR CLEVELAND BY LATE THIS
EVENING...BEFORE DECAYING INTO A REMNANT INVERTED TROUGH AS A
SECONDARY COASTAL LOW RAPIDLY DEVELOPS LATER TONIGHT AND WEDNESDAY
AND BECOMES THE DOMINANT SURFACE FEATURE. BY THE END OF THE
PERIOD...THIS SECONDARY LOW WILL BE CO-LOCATED WITH ITS PARENT UPPER
LEVEL FEATURE IN A POSITION OFF THE MID ATLANTIC COAST.

AS A RESULT OF THESE EVOLUTIONS ON THE SYNOPTIC SCALE...A SWATH OF
WIDESPREAD LIGHT TO MODERATE SNOW IS EXPECTED TO OVERSPREAD MUCH OF
THE AREA TONIGHT IN THE WARM ADVECTION PATTERN/DIFFLUENT UPPER FLOW
REGIME IN ADVANCE OF THE PRIMARY SURFACE LOW AND THE PARENT UPPER
LOW. WHILE THESE FORCING MECHANISMS WILL QUICKLY DEPART OUR AREA
EARLY ON WEDNESDAY...WIDESPREAD SNOW WILL CONTINUE OVER MUCH OF
THE AREA RIGHT THROUGH THE DAY AS THE REMNANT INVERTED TROUGH FROM
THE PRIMARY SURFACE LOW LINGERS ACROSS WESTERN NY INTO THE
MORNING...BEFORE SLOWLY GIVING WAY TO A MOIST NORTHERLY UPSLOPE
CYCLONIC FLOW AS THE SECONDARY SURFACE LOW RAPIDLY DEEPENS OFF THE
EAST COAST.

SINCE LAST NIGHT...THE SHORT TERM MODELS HAVE GENERALLY TRENDED A
BIT FURTHER TO THE NORTH WITH THE EXTENT OF THE OVERALL PRECIP
SHIELD ASSOCIATED WITH THESE FEATURES...WHILE ALSO INCREASING
OVERALL PRECIP AMOUNTS ACROSS OUR AREA. WHILE THE HEAVIEST PRECIP
SHOULD STILL REMAIN SAFELY TO OUR SOUTH AND EAST...STORM TOTAL QPFS
ARE NOW GENERALLY IN THE 0.40-0.60" RANGE FOR AREAS ALONG AND
SOUTH OF THE NEW YORK STATE THRUWAY...WHICH WOULD BE ENOUGH TO
RESULT IN SOME ADVISORY-CRITERIA SNOWS FOR AREAS SOUTH OF THE
COUNTIES IMMEDIATELY ALONG THE SOUTH SHORE OF LAKE ONTARIO. WITH
HPC AND OUR SURROUNDING WFO`S IN GOOD AGREEMENT ON THIS
SCENARIO...HAVE THEREFORE ELECTED TO EXPAND THE WINTER WEATHER
ADVISORIES NORTHWARD TO INCLUDE ERIE...GENESEE...WYOMING...
LIVINGSTON...AND ONTARIO COUNTIES WITH THIS PACKAGE. WITHIN THIS
AREA...STORM TOTAL SNOWFALL OF AS MUCH AS 3 TO 6 INCHES WILL BE
POSSIBLE BY WEDNESDAY EVENING...WITH ABOUT TWO-THIRDS OF ANY SNOW
LIKELY FALLING ON WEDNESDAY. ADVISORIES WILL REMAIN IN EFFECT FOR
THE WESTERN SOUTHERN TIER...WHERE STRONGER UPLIFT WILL LINGER LONGER
AND RESULT IN SLIGHTLY HIGHER TOTALS OF 4 TO 7 INCHES BY THE END OF
THE DAY TOMORROW.

FARTHER TO THE NORTH...SOMEWHAT LESSER TOTAL ACCUMULATIONS OF 2-4"
LOOK LIKELY ALONG THE NIAGARA-OSWEGO COUNTY STRIP AT THIS
POINT...WITH JUST AN INCH OR TWO POSSIBLE ACROSS THE NORTH COUNTRY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A MOIST CYCLONIC FLOW WILL CONTINUE WEDNESDAY NIGHT AS THE COASTAL
LOW CONTINUES TO PULLS FURTHER AWAY FROM THE COAST. ADVISORY SNOWS
WILL BE TAPERING OFF FROM NORTH TO SOUTH DURING THE EVENING WITH
SCATTERED SNOW SHOWERS LEFT BY THURSDAY MORNING.

THURSDAY AND FRIDAY...A COLD NORTH NORTHWEST FLOW WILL PERSIST.
OVER-WATER INSTABILITY WILL REMAIN LIMITED WITH 850 MB TEMPERATURES
BETWEEN -10C AND -12C. LOW LEVEL FLOW WILL REMAIN WEAKLY CYCLONIC...
AS A COUPLE MID LEVEL IMPULSES PUSH SOUTHEAST ACROSS THE LOWER
LAKES. THIS WILL ALLOW FOR SCATTERED SNOW SHOWERS FOR THE ENTIRE
AREA...ALTHOUGH SOME LAKE ENHANCEMENT/UPSLOPE SOUTHEAST OF THE
LAKES IN LIKELY.

HIGHS BOTH DAYS MAINLY IN THE 20S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THIS PERIOD WILL BE DOMINATED BY A BROAD WEST NORTHWEST FLOW ALOFT
AS HIGH PRESSURE REMAINS ANCHORED ACROSS THE OHIO VALLEY/CENTRAL
LAKES AND A DEEP LOW RETROGRADES THROUGH THE CANADIAN MARITIMES.
850 MB TEMPERATURES IN THE -10C TO -14C RANGE WE WILL BE MARGINALLY
COLD ENOUGH FOR LAKE EFFECT/UPSLOPE SNOWS. THIS FLOW REGIME WOULD
FAVOR AREAS SOUTH EAST OF THE LAKES.

ECMWF/GFS CONTINUING TO SUPPORT A CLIPPER SYSTEM WORKING THROUGH THE
AREA LATE SUNDAY THROUGH MONDAY. THIS WOULD BRING A MORE WIDESPREAD
GENERAL SNOWFALL TO THE AREA. LAKE ENHANCEMENT SOUTHEAST OF THE
LAKES IS LIKELY.

THIS FLOW REGIME SHOULD ALLOW FOR BELOW NORMAL TEMPERATURES DURING
THE PERIOD. EXPECT HIGHS IN THE UPPER TEENS TO MID 20S WITH LOWS IN
THE SINGLE DIGITS TO MID TEENS...WHICH ARE A GOOD 5 DEGREES BELOW
NORMAL FOR FOR MID FEBRUARY.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
LOW PRESSURE CENTERED OVER WESTERN LAKE ERIE WILL WEAKEN GRADUALLY
OVERNIGHT...THEN MERGE WITH AN INTENSIFYING EAST COAST STORM ON
WEDNESDAY.

MAINLY LIGHT SNOW FORMING NORTH OF THE LAKE ERIE LOW WILL PICK UP IN
INTENSITY LATER TONIGHT AND WEDNESDAY AS LOW LEVEL CONVERGENCE
INCREASES ALONG AN INVERTED TROUGH IS FORECAST TO SET UP BETWEEN THE
WEAKENING LOWER LAKES LOW AND THE INTENSIFYING COASTAL LOW.

EXPECT MAINLY MVFR CONDITIONS TO DETERIORATE TO IFR AS THE SNOW
BECOMES A BIT MORE STEADY LATE TONIGHT AND WEDNESDAY.

THE STEADIER SNOW WILL TAPER OFF GRADUALLY FROM WEST TO EAST
WEDNESDAY AFTERNOON AS THE COASTAL LOW TAKES OVER. THIS WILL ALLOW
CONDITIONS TO IMPROVE TO MVFR LATE IN THE AFTERNOON...MAINLY NORTH
OF THE SOUTHERN TIER.

OUTLOOK...
THURSDAY THROUGH SATURDAY...VFR/MVFR WITH A CHANCE OF SNOW
SHOWERS.
SUNDAY...MAINLY VFR.
MONDAY...MVFR/IFR WITH SNOW LIKELY.
TUESDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS.
-- End Changed Discussion --

&&

.MARINE...
A COASTAL LOW WILL ORGANIZE OFF THE DELMARVA COAST TONIGHT...
STRENGTHENING AS IT MOVES OFF THE EAST COAST THROUGH WEDNESDAY.
NOTED A NARROW LAYER OF 25 KT PLUS NORTHEAST WINDS BELOW 2000
FEET ON BUFKIT...WHICH SPREADS FROM WEST TO EAST OVERNIGHT. ON
LAND...THIS SHOULD NOT MIX DOWN...BUT IT SHOULD HAVE BETTER LUCK
ON THE LAKES...AND PERHAPS IN THE NIAGARA REGION. EXPECT WINDS TO
REMAIN UP ON LAKE ERIE THROUGH THIS EVENING...PICKING UP ON
WESTERN ONTARIO...AND EVENTUALLY EASTERN ONTARIO TOWARDS DAYBREAK.
NO CHANGES TO HEADLINES.

WINDS WILL THEN TO NORTHWEST AS THE LOW WITHDRAWS WEDNESDAY.
SMALL CRAFT CONDITIONS WILL DEVELOP ON THE LAKE ONTARIO NEARSHORE
FROM SODUS BAY TO THE NIAGARA RIVER AROUND MIDNIGHT
TONIGHT...REACHING THESE LEVELS FROM SODUS BAY TO MEXICO BAY BY
NOON WEDNESDAY. THESE CONDITIONS WILL PERSIST ON LAKE ONTARIO
THROUGH AT LEAST WEDNESDAY NIGHT.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 7 PM EST WEDNESDAY FOR
     NYZ010>014-019>021-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR LOZ042-043.
         SMALL CRAFT ADVISORY FROM NOON WEDNESDAY TO 1 AM EST
         THURSDAY FOR LOZ044.

&&

$$

SYNOPSIS...TMA
NEAR TERM...APFFEL/JJR
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...TJP
MARINE...APFFEL/JJR/TMA