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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBUF 101130
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
630 AM EST WED FEB 10 2010

.SYNOPSIS...
LOW PRESSURE OFF THE COAST OF MARYLAND THIS MORNING WILL CONTINUE TO
STRENGTHEN RAPIDLY AS IT MOVES NORTHEAST TODAY TO EAST OF LONG
ISLAND BY THIS EVENING. THE STORM WILL PRODUCE ACCUMULATING SNOWS
OVER MOST OF OUR REGION BUT WE WILL DODGE ANOTHER BULLET AS THE REAL
HEAVY SNOW REMAINS TO OUR SOUTH AND EAST ACROSS THE MAJOR EASTERN
CITIES. THE STORM WILL EVENTUALLY END UP NEAR NEWFOUNDLAND BY FRIDAY
AND THEN DRIFT BACK TO THE WEST OVER THE CANADIAN MARITIMES OVER THE
WEEKEND. THIS WILL KEEP US COLDER THAN NORMAL WITH A NORTHWEST FLOW
DRAWING IN AIR FROM THE HUDSON BAY AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
MOISTURE CHANNEL IMAGERY SHOWING A WELL DEFINED MID LEVEL CLOSED LOW
OVER SOUTH CENTRAL OHIO AT 08Z WITH AN IMPRESSIVE EXTENSION OF THE
SUB-TROPICAL UPPER LEVEL JET WRAPPING NORTHWARD UP THE GULF STREAM
TO THE EAST OF THE CLOSED LOW. AT THE SURFACE...08Z SURFACE ANALYSIS
SHOWS A PARENT LOW CENTERED OVER NORTHWEST PENNSYLVANIA WITH
SECONDARY COASTAL CYCLOGENESIS BEGINNING TO TAKE SHAPE OFF CAPE
HATTERAS. SHORT TERM MODEL GUIDANCE CONTINUES TO BE IN GOOD
AGREEMENT WITH THE HANDLING OF THE LARGE SCALE FEATURES...WITH THE
MID LEVEL CLOSED LOW PASSING BY TO OUR SOUTH THROUGH MIDDAY TODAY.
THE PARENT LOW WILL QUICKLY FILL AND GIVING WAY TO THE COASTAL LOW
THIS MORNING AS MID LEVEL HEIGHT FALLS OVERSPREAD THE COASTAL
FRONT...WHICH WILL UNDERGO BOMBOGENESIS OVER THE NEXT 24 HOURS AS IT
DEEPENS TO 970MB OR LOWER ON ITS WAY OUT TO SEA.

LOOKING AT THE FINER SCALE DETAILS...AN INVERTED TROUGH WILL BE LEFT
BEHIND ACROSS NORTHWEST PA AND WESTERN NY THROUGH MIDDAY TODAY AS A
REMNANT OF THE PARENT SURFACE LOW. THIS SHOULD ACT TO ENHANCE
CONVERGENCE ACROSS WESTERN NY...ESPECIALLY THE WESTERN SOUTHERN TIER
THROUGH THE MORNING HOURS. REGIONAL RADAR IMAGERY SHOWS SNOW IN
POCKETS RATHER THAN A SOLID SHIELD...INDICATIVE OF A WEAKENING
SYSTEM. EXPECT THE SNOW TO BECOME MORE WIDESPREAD BY DAYBREAK AS THE
INVERTED TROUGH WORKS NORTHWARD AND A LARGER AREA OF SNOW OVER
WESTERN PA PIVOTS NORTH AHEAD OF THE MID LEVEL CLOSED LOW.

FROM MIDDAY INTO THE AFTERNOON LOW LEVEL FLOW WILL GRADUALLY BACK
FROM NORTHEAST TO NORTH WITH WRAP AROUND MOISTURE DEEPENING ACROSS
THE AREA. THIS SHOULD SET THE STAGE FOR OUR TYPICAL UPSLOPE SNOW WE
SEE ON THE BACKSIDE OF MANY SYSTEMS. EXPECT A PERIOD OF ACCUMULATING
SNOW TO WORK SOUTH FROM THE NIAGARA FRONTIER INTO THE SOUTHERN TIER
AND FINGER LAKES WITH THIS. THE BEST UPSLOPE WILL BE ACROSS THE
HIGHER TERRAIN OF THE CHAUTAUQUA RIDGE. THE LAKES ARE NO CONCERN
THROUGH THE DAY TODAY...WITH THE AIRMASS SIMPLY NOT COLD ENOUGH FOR
ANY LAKE ENHANCEMENT.

AS FAR AS AMOUNTS GO...EXPECT THE HEAVIEST SNOW TO BE FOUND ACROSS
THE HIGHER TERRAIN OF CHAUTAUQUA AND CATTARAUGUS COUNTIES DUE TO A
COMBINATION OF CLOSE PROXIMITY TO THE INVERTED TROUGH THIS MORNING
THEN UPSLOPE THIS AFTERNOON. HAVE GONE WITH MAX AMOUNTS OF AROUND 6
INCHES IN THIS AREA TODAY. AMOUNTS WILL QUICKLY DIMINISH MOVING AWAY
FROM THIS AREA...WITH 3-4 INCHES ACROSS ALLEG/SOUTHERN ERIE/WYOMING
COUNTIES WITH 2-3 INCHES IN THE BUFFALO TO BATAVIA CORRIDOR. EXPECT
AMOUNTS TO DIMINISH FURTHER ALONG THE SOUTH SHORE OF LAKE ONTARIO
WITH 1-2 INCHES ALONG THE TIER OF COUNTIES BORDERING THE LAKE. TOUGH
CALL ON POPS AND SNOW AMOUNTS EAST OF LAKE ONTARIO. IT APPEARS LOW
LEVEL DRY AIR WILL WIN OUT FOR THE MOST PART...WITH ONLY SOME
SCATTERED SNOW SHOWERS OR LIGHT SNOW MAKING IT IN AT TIMES LATER
TODAY. EXPECT ACCUMS TO ONLY BE A DUSTING TO AN INCH...WITH THE 1
INCH AMOUNTS CONFINED TO THE HIGHER TERRAIN OF THE TUG HILL.

TONIGHT THE SYNOPTIC SNOW WILL QUICKLY END FROM NORTH TO SOUTH AS
THE COASTAL LOW PULLS OUT TO SEA. THIS WILL LEAVE SOME LINGERING
WRAP AROUND MOISTURE...ENOUGH TO PRODUCE A FEW SCATTERED SNOW
SHOWERS OR FLURRIES OVERNIGHT. OUR ATTENTION THEN TURNS BACK TO THE
MESOSCALE. AIRMASS BECOMES MARGINALLY COLD ENOUGH TO SUPPORT A VERY
LIMITED LAKE RESPONSE OFF LAKE ONTARIO LATER TONIGHT WITH 850MB
TEMPS BOTTOMING OUT AROUND -10C. THIS WILL YIELD LAKE INDUCED CAPES
OF AROUND 130J/KG AND EQUILIBRIUM LEVELS AROUND 4K FEET. THE
THERMODYNAMICS ARE VERY LIMITED...BUT SIMILAR VALUES PRODUCED SOME
LIGHT SNOW EARLIER IN THE WEEK. WITH THIS IN MIND...WILL INCLUDE AN
AREA OF HIGHER POPS ALONG THE SOUTH SHORE OF LAKE ONTARIO ESPECIALLY
FROM ORLEANS TO WESTERN OSWEGO COUNTY. MAY SEE SOME SPOTTY 1-2 INCH
ACCUMULATIONS OUT OF THIS.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THE DEEP COASTAL LOW WILL CONTINUE TO MOVE NORTHEAST DURING THIS
PERIOD AND WIND UP NEW NEWFOUNDLAND BY FRIDAY EVENING. THE
CIRCULATION PATTERN AROUND THIS LARGE DEEP LOW WILL REACH AS FAR
WEST AS THE LOWER GREAT LAKES. IT WILL PRODUCE A NORTHWEST FLOW OF
COLDER THAN NORMAL AIR ACROSS OUR REGION.

LOOKING AT THE PROJECTED SOUNDINGS THE COLD BOUNDARY LAYER WILL BE
MOIST BUT RATHER SHALLOW WITH A SUBSIDENCE INVERSION AROUND 3
THOUSAND FEET. THERE IS NOT MUCH MOISTURE ADVERTISED IN THE CRYSTAL
GROWTH REGION. SO...IT APPEARS THAT WE WILL END UP WITH A LOT OF
CLOUD COVER BUT NOT VERY MUCH SNOW. WE WILL CARRY CHANCE
PROBABILITIES FOR MOST AREAS AND SOME LIKELIES SOUTH AND SOUTHEAST OF
LAKE ONTARIO. WE WILL KEEP QPF AND SNOW AMOUNTS VERY SMALL.

&&

.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 /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
STEADY SNOW WILL CONTINUE ACROSS MOST OF WESTERN AND CENTRAL NEW
YORK THROUGH THE MORNING AND AFTERNOON HOURS. EXPECT WIDESPREAD IFR
FROM ABOUT INTERSTATE 90 SOUTHWARD...WITH THE LOWEST CONDITIONS
ACROSS THE SOUTHERN TIER. FARTHER NORTH...EXPECT MVFR WITH A FEW
PERIODS OF IFR ALONG THE SOUTH SHORE OF LAKE ONTARIO. EAST OF LAKE
ONTARIO EXPECT CONDITIONS TO REMAIN MAINLY VFR THIS MORNING BEFORE
SOME LIGHT SNOW DEVELOPS THIS AFTERNOON WITH AREAS OF MVFR.

TONIGHT THE SNOW WILL TAPER OFF FROM NORTH TO SOUTH DURING THE
EVENING WITH CONDITIONS RETURNING TO MVFR. OVERNIGHT SOME LIGHT LAKE
EFFECT SNOW IS EXPECTED TO DEVELOP ALONG THE SOUTH SHORE OF LAKE
ONTARIO...POSSIBLY IMPACTING KROC AFTER 06Z WITH PERIODS OF IFR
CONDITIONS.

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

&&

.MARINE...
SMALL CRAFT ADVISORIES WILL CONTINUE THROUGH AT LEAST THURSDAY AS
THE DEEPENING COASTAL LOW MOVING TOWARD NOVA SCOTIA CONTINUES TO
HAVE A LARGE INFLUENCE ON THE CIRCULATION PATTERN TO THE WEST OF
IT. THE PRESSURE GRADIENT WILL REMAIN TIGHT ENOUGH FOR BRISK WINDS
AND WAVE ACTION. THE NORTHWEST FLOW WILL PERSIST RIGHT INTO THE
WEEKEND AND MAY STRENGTHEN AS THE LOW RETROGRADES TO THE CANADIAN
MARITIMES.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     NYZ010>014-019>021-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR LOZ042-043.
         SMALL CRAFT ADVISORY FROM NOON TODAY TO 5 PM EST THURSDAY
         FOR LOZ044.

&&

$$

SYNOPSIS...SAGE
NEAR TERM...HITCHCOCK
SHORT TERM...SAGE
LONG TERM...TMA
AVIATION...HITCHCOCK
MARINE...SAGE