074
FXUS61 KBUF 090248
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
948 PM EST THU DEC 8 2022
SYNOPSIS
SPOTTY LAKE EFFECT SPRINKLES AND FLURRIES SOUTH OF LAKE ONTARIO WILL
GRADUALLY SHIFT WESTWARD AND WIND DOWN OVERNIGHT. OTHERWISE...DRY
WEATHER WILL PREVAIL THROUGH SATURDAY AS STRONG CANADIAN HIGH
PRESSURE BUILDS EAST ACROSS ONTARIO AND QUEBEC. WEAK LOW PRESSURE
PUSHING ACROSS THE GREAT LAKES WILL THEN SPREAD A MIX OF RAIN AND
WET SNOW ACROSS THE REGION SATURDAY NIGHT AND SUNDAY...WITH THE
MAJORITY OF ANY SNOW ACCUMULATION EXPECTED TO BE ACROSS THE HIGHER
TERRAIN.
NEAR TERM /THROUGH FRIDAY/
AS OF MID TO LATE EVENING...SOME VERY SPOTTY LIGHT LAKE EFFECT
PRECIP STILL PERSISTS OVER CENTRAL LAKE ONTARIO AND PORTIONS OF THE
FINGER LAKES REGION...WITH ONGOING LAKE EFFECT AND UPSLOPE PROCESSES
ALSO CONTINUING TO SLOWLY FILL IN ANY GAPS IN THE CLOUD COVER
OVER AND SOUTH OF LAKE ONTARIO. THIS LATER TREND SHOULD CONTINUE
THROUGH THE REST OF THE NIGHT AND RESULT IN SKIES BECOMING
MOSTLY CLOUDY AGAIN SOUTH OF LAKE ONTARIO...WHILE THE LINGERING
SPOTTY LAKE EFFECT PRECIP SHIFTS WESTWARD AND GRADUALLY WEAKENS
AS THE LOW LEVEL FLOW VEERS MORE NORTHEASTERLY AND INVERSION
HEIGHTS SLOWLY DROP.
MEANWHILE EAST OF LAKE ONTARIO...SKIES SHOULD HAVE A TENDENCY TO AT
LEAST PARTIALLY CLEAR OUT OVERNIGHT AS DRIER AIR ADVECTS INTO THAT
AREA. OVERNIGHT LOWS WILL BE IN THE UPPER 20S TO LOWER 30S SOUTH OF
LAKE ONTARIO...AND IN THE UPPER TEENS TO MID 20S ACROSS THE NORTH
COUNTRY.
QUIET WEATHER IS THEN EXPECTED ON FRIDAY WITH SHORTWAVE RIDGING
OVERHEAD AND HIGH PRESSURE FIRMLY IN CONTROL. SOME LAKE-DRIVEN CLOUD
COVER MAY LINGER SOUTHWEST OF LAKE ONTARIO THROUGH THE DAY, BUT
OTHERWISE EXPECT MUCH MORE IN THE WAY OF SUNSHINE COMPARED TO THE
PREVIOUS FEW DAYS. HIGH TEMPERATURES WILL GENERALLY BE IN THE MID TO
UPPER 30S...WITH DANSVILLE AND LOCATIONS ALONG THE LAKE ERIE
SHORELINE POTENTIALLY REACHING OR BREAKING 40F.
SHORT TERM /FRIDAY NIGHT THROUGH MONDAY/
A MID LEVEL CLOSED LOW AND WEAK SURFACE LOW OVER SOUTHERN LAKE
MICHIGAN FRIDAY EVENING WILL MOVE EAST TO THE WEST END OF LAKE ERIE
BY SATURDAY MORNING AND WEAKEN WITH TIME, EVENTUALLY DISSIPATING
COMPLETELY LATER SATURDAY AS IT MOVES INTO A MEAN RIDGE POSITION.
THIS SYSTEM WILL BRING SOME INCREASE IN CLOUD COVER ACROSS WESTERN
NY LATER FRIDAY NIGHT AND EARLY SATURDAY, BUT ANY LIGHT
PRECIPITATION WILL REMAIN SOUTHWEST OF OUR AREA WITH DRY WEATHER
PREVAILING. OTHERWISE STRONG HIGH PRESSURE WILL REMAIN IN PLACE
OVER NORTHERN QUEBEC, WITH A RIDGE EXTENDING DOWN INTO THE EASTERN
GREAT LAKES AND NEW ENGLAND FRIDAY NIGHT THROUGH SATURDAY EVENING
SUPPORTING DRY WEATHER.
OUR ATTENTION THEN TURNS TO ANOTHER PACIFIC ORIGIN TROUGH, WHICH
WILL REACH THE WESTERN GREAT LAKES SATURDAY NIGHT BEFORE MOVING INTO
THE EASTERN GREAT LAKES AND EVOLVING INTO A MID LEVEL CLOSED LOW BY
SUNDAY. THE WEAK SURFACE LOW ASSOCIATED WITH THIS MID LEVEL LOW WILL
MOVE INTO WESTERN NY SUNDAY AFTERNOON AND CENTRAL NY SUNDAY EVENING
BEFORE RE-DEVELOPING OFF THE SOUTHERN NEW ENGLAND COAST BY MONDAY
MORNING.
A PERIOD OF ORGANIZED ASCENT AND DEEP MOISTURE WILL SPREAD INTO
WESTERN NY LATE SATURDAY NIGHT, AND THEN THE REST OF THE AREA SUNDAY
MORNING IN RESPONSE TO DPVA AHEAD OF THE MID LEVEL LOW, DIFFLUENT
MID/UPPER LEVEL FLOW, AND STRENGTHENING FRONTOGENESIS ALONG AND
NORTH OF THE SURFACE LOW. EXPECT A PERIOD OF WIDESPREAD
PRECIPITATION LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AS THIS
SYSTEM CROSSES THE AREA. PRECIPITATION WILL GRADUALLY TAPER OFF
LATER SUNDAY NIGHT THROUGH MONDAY MORNING AS THE COASTAL LOW OFF THE
NEW ENGLAND COAST TAKES OVER. WEAK NORTHERLY UPSLOPE FLOW AND
MODESTLY COLDER AIR MAY SUPPORT SOME MINOR LAKE EFFECT AND UPSLOPE
PRECIPITATION LASTING INTO MONDAY MORNING BEFORE ENDING IN THE
AFTERNOON.
THE MAIN CHALLENGE WITH THIS SYSTEM WILL BE PTYPE GIVEN THE MARGINAL
SURFACE TEMPERATURES AND THERMAL PROFILES. MODEL POINT SOUNDINGS
SUGGEST THE SURFACE WILL BE A LITTLE ABOVE FREEZING FOR MOST LOW
ELEVATION SITES THROUGH MOST OF THIS EVENT, AND NEAR FREEZING FOR
HIGHER ELEVATION LOCATIONS. THE BOURGOUIN PRECIPITATION TYPE METHOD
FROM GFS BUFKIT POINT SOUNDINGS AND NBM PROBABILITIES SUGGEST MAINLY
SNOW AT THE ONSET FOR ALL OF THE AREA, WITH A RAIN/SNOW MIX BECOMING
MORE LIKELY DURING THE MIDDAY AND AFTERNOON HOURS FOR THE LOWER
ELEVATIONS OF WESTERN NY. MAINLY SNOW IS FAVORED FOR MOST OF THE
EVENT ACROSS HIGHER TERRAIN AND ALSO LOCATIONS FROM ROCHESTER
EASTWARD. NONE OF THE FORECAST POINT SOUNDINGS SUGGEST ANY TYPE OF
WINTRY MIX, WITH THIS EVENT BEING EITHER RAIN OR WET SNOW BASED ON
THE THERMAL STRUCTURE OF THE LOWEST THOUSAND FEET OR SO OF THE
COLUMN.
GIVEN THE MARGINAL THERMAL STRUCTURE, EXPECT SNOW ACCUMULATION TO BE
HIGHLY DEPENDENT ON ELEVATION, WITH THE BEST CHANCE OF MEANINGFUL
ACCUMULATIONS ACROSS HIGHER TERRAIN, AND A MUCH LOWER CHANCE AT
LOWER ELEVATIONS. IT'S STILL TOO EARLY FOR SPECIFIC ACCUMULATIONS
BUT IN GENERAL THIS STILL APPEARS TO BE A MINOR, LOW IMPACT EVENT
FOR MOST AREAS.
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
A MATURING CYCLONE (VERTICALLY STACKED) WILL EVER SO SLOWLY TREK
EAST OVER THIS TIME PERIOD. DUE TO ITS SLOW MOVEMENT EAST, HAVE
AGAIN DELAYED AND LOWERED NBM POPS WITH DRY WEATHER NOW ANTICIPATED
THROUGH AT LEAST WEDNESDAY AFTERNOON. AFTER THAT...IT WILL ALL
DEPEND ON THE EVENTUAL ARRIVAL OF THIS SYSTEM FRONT (OCCLUSION),
POSSIBLY ON THURSDAY WITH A RAIN OR WET SNOW MIX AT ONSET. UNSETTLED
WEATHER WILL THEN PERSIST INTO FRIDAY AND THE WEEKEND AS THIS WHOLE
COMPLEX LUMBERS ITS WAY THROUGH THE GREAT LAKES AND NEW ENGLAND.
STILL NO SIGN OF ANY REAL COLD ARCTIC AIR PLUNGING EAST AND
SOUTHEAST ACROSS THE GREAT LAKES WITH WINTER LOCKED ACROSS THE
NORTHERN ROCKIES (CANADA). THAT SAID, IT MAY STILL BE COLD ENOUGH
FOR A WINTRY END TO NEXT WEEK, DEPENDING ON THE EVENTUAL TRACK AND
STRENGTH OF THE LATE WEEK SYSTEM.
AVIATION /03Z FRIDAY THROUGH TUESDAY/
A NORTHERLY TO NORTHEASTERLY UPSLOPE FLOW AND LAKE INFLUENCES WILL
LEAD TO A CONTINUED RETURN OF FAIRLY WIDESPREAD MVFR TO LOWER-END
VFR CEILINGS SOUTH OF LAKE ONTARIO OVERNIGHT...WITH LINGERING LIGHT
LAKE EFFECT SHOWERS ACROSS THE FINGER LAKES GRADUALLY SHIFTING
WESTWARD AND WEAKENING OVERNIGHT. MEANWHILE ACROSS THE NORTH
COUNTRY...INCREASINGLY DRIER AIR ASSOCIATED WITH HIGH PRESSURE
PUSHING ACROSS NORTHERN ONTARIO AND QUEBEC SHOULD HELP TO BREAK UP
ANY LINGERING LOWER CLOUDS...WITH CONDITIONS IMPROVING TO VFR THERE.
DURING FRIDAY...VFR CONDITIONS WILL CONTINUE ACROSS THE NORTH
COUNTRY. SOUTH OF LAKE ONTARIO...A MIX OF WIDESPREAD MVFR TO VFR
CLOUD COVER TO START THE DAY WILL GRADUALLY BREAK UP AND IMPROVE
TO VFR FROM SOUTHEAST TO NORTHWEST.
OUTLOOK...
SATURDAY...MAINLY VFR.
SUNDAY...MVFR/IFR WITH RAIN AND WET SNOW LIKELY.
MONDAY...MVFR/IFR WITH RAIN AND WET SNOW SHOWERS EARLY, IMPROVING
TO MAINLY VFR.
TUESDAY...VFR.
MARINE
SURFACE HIGH PRESSURE ACROSS NORTHERN ONTARIO WILL PUSH INTO QUEBEC
OVER NIGHT...WITH MODEST NORTHERLIES TO NORTHEASTERLIES EXPECTED
ACROSS LAKES ERIE AND ONTARIO.
NORTHEASTERLY WINDS WILL THEN INCREASE ON FRIDAY AS THE PRESSURE
GRADIENT TIGHTENS BETWEEN STRONG HIGH PRESSURE OVER QUEBEC AND A
WEAKENING SURFACE LOW DIVING SOUTHEASTWARD ACROSS THE OHIO VALLEY.
THIS WILL LIKELY SUPPORT A ROUND OF SMALL CRAFT ADVISORY CONDITIONS
ACROSS LAKE ERIE FRIDAY NIGHT...AND LAKE ONTARIO FRIDAY NIGHT AND
SATURDAY.
BUF WATCHES/WARNINGS/ADVISORIES
NY...NONE.
MARINE...NONE.
SYNOPSIS...JJR/PP
NEAR TERM...JJR/PP
SHORT TERM...HITCHCOCK
LONG TERM...AR
AVIATION...JJR/PP
MARINE...JJR/PP
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