National Weather Service Weather Forecast Office

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

000
FXUS61 KBUF 060907
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
407 AM EST FRI DEC 6 2013

.SYNOPSIS...
IN THE WAKE OF A COLD FRONT...PROGRESSIVELY COLDER AIR WILL FLOOD
ACROSS THE REGION OVERNIGHT AND FRIDAY. THIS WILL RESULT IN A
CHANGEOVER TO SNOW BEFORE DIMINISHING LATE TONIGHT. MUCH COLDER
TEMPERATURES WILL REMAIN IN PLACE TODAY THROUGH THE UPCOMING
WEEKEND. LATER TODAY INTO TONIGHT ANOTHER WAVE OF LOW PRESSURE WILL
LIFT NORTHEAST ACROSS THE MID ATLANTIC STATES...AND THIS WILL
BRING A PERIOD OF LIGHT TO MODERATE SNOW TO AREAS SOUTH OF LAKE
ONTARIO.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WAVE OF LOW PRESSURE WILL RIDE NORTHEASTWARD ALONG A COLD FRONT
WHICH IS NOW ACROSS SOUTHERN NEW ENGLAND AND EASTERN NEW YORK DOWN
THE SPINE OF THE APPALACHIANS. THIS WEAK WAVE CENTERED ALONG THE FRONT
OVER EASTERN PA IS NOW SPREADING MOISTURE AND LIFT NORTHWESTWARD
ACROSS WESTERN AND CENTRAL NEW YORK. MUCH OF OUR REGION REMAINS
ABOVE FREEZING AT 1AM BUT SUB-FREEZING AIR JUST ABOVE THE SURFACE IS
ALLOWING FOR SNOW AND SLEET TO MIX IN WITH RAIN SHOWERS BEFORE
SWITCHING TO ALL SNOW OVERNIGHT AS TEMPERATURES COOL FURTHER TOWARD
FREEZING. TOWARD DAYBREAK INCREASING LOW LEVEL RIDGING AND DRYING
BEHIND THE WAVE OF LOW PRESSURE AS IT DEPARTS INTO NEW ENGLAND
SHOULD BRING AN OVERALL DIMINISHING TREND IN THE PCPN FROM NORTHWEST
TO SOUTHEAST. THE 00Z GUIDANCE SUITES AND CURRENT RADAR TRENDS SHOW
A SHARP GRADIENT IN PRECIP A BIT FURTHER NORTHWEST THEN EXPECTED SO
HAVE UPDATED FORECAST GRIDS TO REFLECT THIS. THE SHARP GRADIENT NOW
LIES ACROSS NIAGARA COUNTY WITH SHARPLY INCREASING CHANCES OF
PRECIPITATION TO THE SOUTHEAST.

FAIRLY LIMITED QPF AND ONLY MARGINAL BOUNDARY LAYER TEMPS ARE
EXPECTED FOLLOWING THE CHANGEOVER TO ALL SNOW SO DO NOT ANTICIPATE A
GREAT DEAL OF SLEET AND SNOW ACCUMULATION TONIGHT. ONLY AN INCH OR
SO FALLING ACROSS THE HIGHER TERRAIN WITH AN INCH OR LESS AT THE
LOWER LEVELS TOWARD THE LAKE SHORES. MODEL SOUNDINGS ALSO SUGGEST
THAT THERMAL PROFILES WILL GENERALLY NOT BE SUPPORTIVE OF FREEZING
RAIN DURING THE CHANGEOVER...WITH A QUICKLY DEEPENING LAYER OF
SUBFREEZING AIR UNDERCUTTING JUST A THIN LAYER OF WARMER AIR ALOFT.
AS SLEET/SNOWFALL ACCUMULATIONS LOOK TO REMAIN FAIRLY MINIMAL AND
THE POTENTIAL FOR FREEZING RAIN LOOKING TO BE RATHER LOW...DO NOT
FEEL THAT ANY WINTER WEATHER ADVISORIES ARE CURRENTLY NECESSARY FOR
TONIGHT.

ON FRIDAY...EXPECT A RELATIVE LULL DURING THE MORNING AS THE REMAINS
OF TONIGHT`S WAVE DEPART OFF TO OUR SOUTH AND EAST...BEFORE YET
ANOTHER AND STRONGER SURFACE WAVE DEVELOPS FROM THE TENNESSEE VALLEY
INTO THE MID ATLANTIC STATES. DURING THE AFTERNOON...THIS FEATURE
WILL SPREAD INCREASING AMOUNTS OF MOISTURE AND LIFT BACK NORTHWARD
INTO OUR REGION...WHICH WILL RESULT IN SOME LIGHT SNOW FIRST
BREAKING OUT ACROSS THE SOUTHERN TIER...WITH THE NORTHERN EDGE OF
THIS THEN SLOWLY SPREADING NORTH TO ROUGHLY THE NYS THRUWAY CORRIDOR
BY SUNSET. WHILE CURRENT MODEL/WPC QPF CONSENSUS AND MARGINAL
BOUNDARY LAYER TEMPS SUGGEST THAT MOST AREAS NORTH OF THE SOUTHERN
TIER WILL SEE LITTLE IF ANY ACCUMULATION OUT OF THIS THROUGH LATE
TOMORROW AFTERNOON...AREAS CLOSER TO THE PENNSYLVANIA BORDER COULD
SEE AS MUCH AS 1-2 INCHES...WITH SOMEWHAT GREATER ADDITIONAL
ACCUMULATIONS EXPECTED TO FOLLOW FRIDAY EVENING. TAKING THESE
TOGETHER...WE HAVE ELECTED TO HOIST A WINTER WEATHER ADVISORY FOR
OUR THREE SOUTHERN TIER COUNTIES FOR TOMORROW AFTERNOON AND
NIGHT...MORE DETAILS ON WHICH ARE PROVIDED WITHIN THE SHORT TERM
SECTION BELOW.

IN TERMS OF TEMPERATURES...MOST AREAS WILL SEE LOWS DIPPING BACK
INTO THE LOWER TO MID 30S TONIGHT...WITH HIGHS THEN ONLY RECOVERING
SOME 3-5 DEGREES ON FRIDAY GIVEN WHAT SHOULD BE ABUNDANT CLOUD COVER
AND CONTINUED COLD AIR ADVECTION.

&&

.SHORT TERM / SATURDAY THROUGH MONDAY/... COLDER AIR ADVECTING
INTO THE REGION WILL MAKE FOR A CHILLY DAY ON SATURDAY WITH HIGHS
ONLY TOPPING OUT IN THE UPPER 20S TO LOWER 30S AND GENERATE ENOUGH
OF A LAKE RESPONSE FOR LINGERING LAKE EFFECT SHOWERS THE FIRST
HALF OF THE DAY BEFORE INCREASING MID-LEVEL DRY AIR/ANTICYCLONIC
FLOW KILL OFF ACTIVITY OFF LAKE ERIE BY MID-DAY. THE LONGER FETCH
OFF LAKE ONTARIO MAY ALLOW LIGHT SNOW SHOWERS TO LINGER THROUGH
THE REST OF THE DAY AND INTO SAT NIGHT...THOUGH BY LATE SAT NIGHT
WEAKENING FLOW AS SURFACE HIGH PRESSURE MOVES OVERHEAD SHOULD
BRING AN END TO ANY ACTIVITY. THE AFOREMENTIONED AREA OF HIGH
PRESSURE WILL BRING LIGHT WINDS SATURDAY NIGHT...HOWEVER LINGERING
LAKE INDUCED CLOUD COVER SHOULD LIMIT RADIATIONAL COOLING ACROSS
MANY AREAS...KEEPING LOWS IN THE 20S. PORTIONS OF THE SOUTHERN
TIER AND NORTH COUNTRY SHOULD STILL SEE ENOUGH CLEARING TO MANAGE
TO DROP INTO THE TEENS OVERNIGHT.

LOOK FOR A QUIET DAY SUNDAY AS HIGH PRESSURE DRIFTS OFF TO THE EAST
ACROSS NEW ENGLAND. INCREASING SOUTHERLY FLOW AHEAD OF AN
APPROACHING WARM FRONT WILL BRING INCREASINGLY CLOUDY SKIES FROM THE
SOUTH DURING THE DAY.

ISENTROPIC UPLIFT ALONG THE WARM FRONT LIFTING NORTH ACROSS THE
REGION AHEAD OF A DEVELOPING SURFACE LOW OVER THE CENTRAL GREAT
LAKES WILL GENERATE WIDESPREAD PRECIP ACROSS THE REGION STARTING
NEAR THE PA BORDER SUNDAY EVENING AND WORKING ITS WAY INTO THE NORTH
COUNTRY AFTER MIDNIGHT. AT THIS POINT GENERAL CONSENSUS AMONG MODELS
IS THAT THE BEST DYNAMICS/DPVA WILL REMAIN OVER CANADA WHILE DEEPER
MOISTURE ADVECTION WILL BE FOUND TO OUR EAST ACROSS CENTRAL AND
EASTERN PA/NY ON THE NORTHERN PERIPHERY OF A SECONDARY COASTAL LOW.
THEREFORE...EXPECT PRECIP TO REMAIN RELATIVELY LIGHT WITH ONLY A
TENTH OF AN INCH OR TWO AT BEST. REGARDING PRECIP TYPE...EXPECT
PRECIP TO INITIALLY START OUT AS LIGHT SNOW IN THE EVENING BEFORE
CHANGING OVER TO FREEZING RAIN AS THE WARM NOSE ALOFT MAKES ITS WAY
OVER THE AREA BEFORE CHANGING OVER TO RAIN AS THE BOUNDARY LAYER
WARMS ABOVE FREEZING TOWARDS MORNING. GIVEN THE EXPECTATION THAT
PRECIPITATION WILL BE RELATIVELY LIGHT AND THE FACT THE TEMPERATURES
SHOULD WARM ABOVE FREEZING...THUS KEEPING THE WINDOW FOR ICING
RATHER SMALL...WILL HOLD OFF ON AN ADVISORY AT THIS POINT...THOUGH
SHOULD THE AXIS OF DEEPER MOISTURE WIND UP FARTHER WEST THIS MAY
CHANGE. NONETHELESS...MOTORISTS SHOULD BE PREPARED FOR A PERIOD OF
SLICK ROAD CONDITIONS...PARTICULARLY ACROSS THE SOUTHERN
TIER...SUNDAY NIGHT.

THE BULK OF THE PRECIP WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST
ON MONDAY AS THE WARM FRONT LIFTS INTO NEW ENGLAND. TEMPERATURES
WILL TOP OUT IN THE UPPER 30S TO NEAR 40 THE AXIS OF WARMEST AIR
CROSSES THE AREA BEFORE TEMPERATURES FALL BACK INTO THE 30S DURING
THE AFTERNOON AS THE COLD AIRMASS CURRENTLY OVER THE NORTHERN PLAINS
BEGINS TO FILTER ACROSS THE GREAT LAKES. HOWEVER...TEMPERATURES
SHOULD STAY JUST WARM ENOUGH TO PREVENT LAKE EFFECT FROM GETTING
GOING UNTIL MONDAY NIGHT.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LATEST GFS AND ECMWF RUNS CONTINUE TO SHOW A DEEP MID LEVEL LONGWAVE
TROUGH CENTERED NEAR HUDSON BAY MONDAY NIGHT...WITH BROAD CYCLONIC
WESTERLY FLOW DEVELOPING ACROSS THE GREAT LAKES REGION. THE AIRMASS
BECOMES PLENTY COLD ENOUGH TO SUPPORT A LAKE RESPONSE...WITH ABOUT
-16C AT 850MB ON TUESDAY AND PERHAPS A FEW DEGREES COLDER THAN THAT
WEDNESDAY. THE SYNOPTIC SCALE PATTERN FITS THE ANALOG FOR
SIGNIFICANT LAKE EFFECT SNOW EAST OF THE LAKES. THE PATTERN WOULD
SUGGEST NUMEROUS SMALL SCALE SHORTWAVES TRAVERSING THE MEAN WNW FLOW
ALOFT. CURRENT GUIDANCE SHOWS THE MOST NOTABLE OF THESE PASSING
JUST NORTH OF THE LAKES TUESDAY NIGHT. EACH OF THESE WAVES CAN
RESULT IN SUBTLE LOW LEVEL FLOW CHANGES WHICH CAN MOVE LAKE BANDS
AROUND AND ALSO MODULATE INTENSITY AND ORGANIZATION.

WHILE THE DETAILS CANNOT BE PREDICTED WITH ANY CONFIDENCE AT THIS
LEAD TIME...THE PATTERN NONETHELESS APPEARS VERY FAVORABLE FOR
SIGNIFICANT LAKE SNOWS EAST OF THE LAKES. STAY TUNED.

IT APPEARS MOST IF NOT ALL OF THE SNOW TUESDAY THROUGH THURSDAY WILL
BE LAKE EFFECT...SO OUTSIDE OF LAKE EFFECT AREAS EXPECT JUST PARTLY
SUNNY SKIES.

AS FAR AS TEMPERATURES GO...IT WILL TURN WELL BELOW AVERAGE BY
MIDWEEK WITH HIGHS ONLY IN THE LOW TO MID 20S AND LOWS IN THE
TEENS...WITH SINGLE NUMBERS POSSIBLE IN THE NORMALLY COLDER
LOCATIONS.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
THE COLD FRONT THAT PLOWED ACROSS THE REGION DURING THE LATE
AFTERNOON AND EVENING WILL PUSH EAST TO THE ATLANTIC
COASTLINE DURING THE REMAINING OVERNIGHT HOURS...WITH ANOTHER WAVE OF
LOW PRESSURE RIPPLING NORTHEAST ALONG THIS BOUNDARY. COLDER AIR AND
MOISTURE SPREADING NORTHWEST ACROSS OUR REGION HAS BROUGHT A
CHANGEOVER TO SNOW AND SLEET WHICH WILL CONTINUE THROUGH THE EARLY
MORNING HOURS TAPERING OFF TOWARD DAYBREAK. THE BULK OF ANY
ASSOCIATED IFR RESTRICTIONS SHOULD REMAIN LARGELY SOUTH OF A
KBUF-KROC-KART AXIS...WITH MVFR CONDITIONS CONTINUING ALONG
AND TO THE NORTH OF THIS LINE.

ON FRIDAY...EXPECT A RELATIVE LULL IN THE PRECIPITATION FRIDAY
MORNING WITH GENERAL MVFR TO VFR CONDITIONS...BEFORE YET ANOTHER
APPROACHING WAVE OF LOW PRESSURE SPREADS LIGHT TO MODERATE SNOW AND
IFR CONDITIONS NORTHWARD ACROSS AREAS SOUTH OF KBUF-KROC-KFZY DURING
THE AFTERNOON.

OUTLOOK...
FRIDAY NIGHT...A PERIOD OF SNOW AND ASSOCIATED IFR SOUTH OF LAKE
ONTARIO IN THE EVENING...DIMINISHING OVERNIGHT.
SATURDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS SOUTHEAST OF THE
LAKES.
SUNDAY...MAINLY VFR.
SUNDAY NIGHT AND MONDAY...VFR/MVFR WITH SNOW AND RAIN LIKELY.
TUESDAY...MAINLY VFR WITH A CHANCE OF SNOW SHOWERS/MVFR EAST OF THE
LAKES.

&&

.MARINE...
IN THE WAKE OF A COLD FRONT...BRISK WESTERLY WINDS WILL PRODUCE
ADVISORY-LEVEL CONDITIONS ON LAKE ERIE TONIGHT...AND INTO FRIDAY
ON LAKE ONTARIO. AFTER THAT...EXPECT WINDS AND WAVES TO FALL AND
GENERALLY REMAIN BELOW ADVISORY LEVELS THROUGH THE WEEKEND AS ONLY
A WEAK TO MODEST PRESSURE GRADIENT WILL BE IN PLACE ACROSS THE
LOWER LAKES REGION.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 AM EST SATURDAY FOR NYZ012>014-
     019>021-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR LOZ042-
         043.
         SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
         LOZ044-045.

&&

$$

SYNOPSIS...JJR/RSH
NEAR TERM...RSH/SMITH
SHORT TERM...WOOD
LONG TERM...HITCHCOCK
AVIATION...RSH/SMITH
MARINE...RSH/SMITH