000
FXUS61 KBUF 280813
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
313 AM EST TUE DEC 28 2010
.SYNOPSIS...
A NORTHWEST FLOW OF COLD AIR WILL CONTINUE THROUGH TONIGHT WITH
SCATTERED FLURRIES AND SNOW SHOWERS...ESPECIALLY EAST OF LAKE
ONTARIO WHERE A FEW INCHES OF SNOW MAY ACCUMULATE. A WARMING TREND
WILL THEN BEGIN WITH TEMPERATURES SOARING TO WELL ABOVE AVERAGE BY
THE END OF THE WEEK. THE THAW IS EXPECTED TO LAST ABOUT THREE
DAYS...WITH TEMPERATURES RETURNING TO NEAR AVERAGE BY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK LAKE EFFECT RESPONSE IS EXPECTED TODAY AS THE UPSTREAM
CONNECTION TO GEORGIAN BAY HAS NOT SHOW SIGNS OF DEVELOPING. WILL
STILL HAVE HIGH LIKELY TO CATEGORICAL POPS ALONG THE CENTRAL TO
EASTERN LAKE ONTARIO COUNTIES AS MARGINAL LAKE EFFECT MAY PRODUCE
MEASURABLE SNOW FROM WAYNE TO OSWEGO COUNTIES TODAY AND TONIGHT.
850MB TEMPS WILL SHOW A WARMING TREND FROM WEST TO EAST THROUGH THE
DAY WITH READINGS OVER LAKE ERIE RISING FROM -5C AT 06Z TO AROUND
-3C BY 18Z. COLDER READINGS ALONG THE EASTERN LAKE ONTARIO SHORE OF
-10C TO -11C WILL PERSIST INTO THE EVENING...THEN MODERATING TO
AROUND -6C BY LATER TONIGHT. THIS SHOULD CUT OFF ALL LAKE EFFECT
SNOW FOR THE REGION FOR THE NEXT SEVERAL DAYS...AT LEAST THROUGH THE
END OF THE WEEKEND.
TEMPS TODAY WILL BE IN THE MID 20S TO LOWER 30S NEAR THE
LAKESHORES...PERIODS OF FILTERED SUNSHINE IN THE MORNING WILL OFFER
LITTLE IN THE WAY OF WARMING AND THICKER CLOUDS WILL COVER THE
ENTIRE REGION THIS AFTERNOON. LOWS TONIGHT WILL SHOW ONLY A SLIGHT
DROP FROM THE DAYTIME TEMPS WITH VARIABLE CLOUD COVER AND A FAIR
BREEZE KEEPING THE LOWER AIRMASS MIXED...EXPECT MAINLY MID 20S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AT THE START OF THE PERIOD HIGH PRESSURE WILL BE CENTERED OVER THE
OHIO VALLEY WITH COLD NORTHWEST FLOW OVER THE LOWER LAKES SLOWLY
MODERATING. THE AIRMASS MAY STILL BE COLD ENOUGH EAST AND SOUTHEAST
OF LAKE ONTARIO TO SUPPORT A FEW SCATTERED LAKE EFFECT SNOW SHOWERS
IN THE MORNING FROM WAYNE TO OSWEGO COUNTIES. AMOUNTS WILL BE
MINIMAL AND SHOULD SLOWLY END DURING THE DAY AS TEMPS ALOFT CONTINUE
TO MODERATE AND REMOVE ANY LAKE INSTABILITY. ELSEWHERE EXPECT A DRY
DAY...ALTHOUGH MODEL POINT SOUNDINGS SUGGEST PLENTY OF LOW LEVEL
MOISTURE TRAPPED BENEATH A STEEPENING SUBSIDENCE INVERSION WHICH MAY
PREVENT MUCH IN THE WAY OF SUNSHINE. 850MB TEMPS WARM TO ABOUT -4C
WEST AND -8C EAST BY AFTERNOON...BUT THE STEEP INVERSION WILL
INHIBIT MIXING WITH TEMPS TOPPING OUT AT ABOUT AVERAGE.
HIGH PRESSURE BUILDS OVER THE LOWER LAKES WEDNESDAY NIGHT WITH A
SLOW CLEARING TREND FROM WEST TO EAST AS THE LOW LEVEL MOISTURE
SLOWLY ERODES. ASSUMING THE CLOUDS EVENTUALLY THIN...SHOULD BE A
GOOD RADIATIONAL COOLING NIGHT WITH LIGHT WINDS AND SNOWPACK. THIS
WILL BRING ONE LAST CHILLY NIGHT BEFORE THE LONG ADVERTISED WARMUP
BEGINS.
THURSDAY HIGH PRESSURE SHIFTS TO THE EAST COAST WITH SOUTHERLY
RETURN FLOW INCREASING ACROSS THE OHIO VALLEY AND GREAT LAKES. THE
SOUTHERLY FLOW SHOULD BE ABLE TO DISLODGE LOW LEVEL MOISTURE WITH AT
LEAST SOME SUNSHINE DURING THE DAY. 850MB TEMPS MODERATE TO ABOUT
+2C WEST AND 0C EAST BY AFTERNOON...SUPPORTING HIGHS INTO THE LOWER
40S ACROSS THE LOWER ELEVATIONS OF WESTERN NY...WITH MID TO UPPER
30S ACROSS HIGHER TERRAIN AND EAST OF LAKE ONTARIO.
THURSDAY NIGHT WILL START WITH CLEAR TO PARTLY CLOUDY SKIES...BUT
EXPECT AN INCREASE IN CLOUDS OVERNIGHT SUPPORTED BY A MINORING OUT
MID LEVEL SHORTWAVE AND THE APPROACH OF A WEAK OCCLUDED FRONT.
LATEST OPERATIONAL MODELS AND SREF MEAN CONTINUE TO SUGGEST ANY
PRECIP ASSOCIATED WITH THIS FEATURE WILL DRY UP BEFORE REACHING
WESTERN NY...SO WILL CONTINUE WITH A DRY FORECAST. SOUTHERLY RETURN
FLOW CONTINUES TO INCREASE...AND WILL COMBINE WITH AN INCREASE IN
CLOUD COVER TO KEEP TEMPS MUCH MILDER OVERNIGHT. LOWS WILL ONLY DROP
INTO THE LOWER HALF OF THE 30S ON THE LAKE PLAINS OF WESTERN
NY...WITH MID TO UPPER 20S FARTHER INLAND. EAST OF LAKE ONTARIO
LIGHTER WINDS AND A LONGER PERIOD OF CLEAR SKIES DURING THE EVENING
WILL ALLOW FOR MORE RADIATIONAL COOLING WITH UPPER TEENS TO LOWER
20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
ABOVE AVERAGE MODEL AGREEMENT CONTINUES...WITH GFS/GGEM/EUROPEAN IN
GENERAL AGREEMENT WITH FAIRLY MINOR DIFFERENCES IN TIMING FOR THIS
RANGE. A VERTICALLY STACKED LOW WILL TRACK ACROSS THE UPPER LAKES
FRIDAY NIGHT...AND INTO CANADA THROUGH THE WEEKEND. THIS WILL PUSH A
SIGNIFICANT COLD FRONT ACROSS THE REGION...WITH CONSENSUS TIMING
BRINGING THE FRONT ACROSS LATE SATURDAY INTO SATURDAY NIGHT.
TEMPERATURES WILL WARM AHEAD OF THE FRONT...WITH DEEP SOUTHERLY FLOW
LIKELY RESULTING IN RISING TEMPS FRIDAY NIGHT. EXPECT A BRIEF RISE
TO THE UPPER 40S TO LOWER 50S IMMEDIATELY AHEAD OF THE FRONT ON
SATURDAY AS 850MB TEMPS TOP OUT AROUND +8C. BASED ON MODEL
AGREEMENT...WILL CONTINUE WITH LIKELY POPS FOR SATURDAY AHEAD OF THE
FRONT ACROSS WESTERN NY...AND SATURDAY EVENING FROM THE FINGER LAKES
TO THE EASTERN LAKE ONTARIO REGION. AT THIS POINT DOES NOT LOOK LIKE
A SIGNIFICANT QPF EVENT GIVEN THE FAST MOVEMENT OF THE FRONT AND
LACK OF GULF OF MEXICO RETURN FLOW ALONG AND AHEAD OF THE BOUNDARY.
AS THE FRONT CROSSES...AN ABRUPT DROP IN TEMPERATURES AT ALL LEVELS
WILL OCCUR. WITH A BRISK SW TO WEST FLOW FORECAST TO DEVELOP BEHIND
THE BOUNDARY...A ROUND OF LAKE EFFECT SNOW SHOWERS IS POSSIBLE LATER
SATURDAY NIGHT INTO SUNDAY. 850 MB TEMPS SHOULD COOL TO -12 C OR
SO...PROVIDING MARGINAL INSTABILITY FOR LAKE EFFECT. GIVEN THE
MARGINAL INSTABILITY AND LACK OF DEEP SYNOPTIC SCALE MOISTURE THE
LAKE EFFECT POTENTIAL APPEARS RATHER LIMITED AT THIS POINT...WITH
MEAN WESTERLY FLOW ON SUNDAY FAVORING AREAS EAST OF LAKES ERIE AND
ONTARIO.
HIGH PRESSURE WILL LIKELY RIDGE FROM THE SOUTH ON MONDAY...WITH NEAR
CLIMO TEMPERATURES EXPECTED. TEMPS ALOFT WARM ENOUGH TO ELIMINATE
LAKE EFFECT POTENTIAL...SO FOR NOW WILL LEAVE MONDAY DRY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LOW LEVEL MOISTURE IS EXPECTED AGAIN TO INCREASE, PRODUCING MAINLY
MVFR CIGS EARLY THIS MORNING AND THROUGH THE REST OF THE TAF
PERIOD ACROSS ALL OF THE TAF SITES EXCEPT KART, WHICH SHLD STAY VFR
THROUGH THE NIGHT. SOME SCT LIGHT UPSLOPE SNOW SHWRS ARE EXPECTED TO
REDEVELOP ESPCLY ACROSS THE HIGHER TERRAIN SOUTH OF THE THRUWAY
BETWEEN BUF AND SYR EARLY THIS MORNING.
A BAND OF LK EFFECT SNOW IS EXPECTED TO FORM OFF GEORGIAN BAY ON A
NORTHWEST FLOW. CURRENT THINKING IS THAT THE HEAVIEST SNOW IS NOW
EXPECTED TO FALL EAST OF THE KROC TAF SITE AFTER 06Z-07Z AND
GRADUALLY SHIFT EASTWARD AS THE WINDS BACK. FOR NOW WILL CARRY VCSH
AT KROC FROM AROUND 07Z-12Z WIHT NO VSBY RESTRICTION BUT THAT WILL
HAVE TO BE WATCHED CLOSELY. AFTER 09Z THE LAKE ENHANCED SNOWS SHLD
SHIFT TOWARD KFZY/KSYR. THE HEAVIER SNOW SHLD STAY SOUTH OF KART
THROUGH THE MID DAY HRS TUESDAY. MVFR CIGS ARE EXPECTED TO DEVELOP
AT KART AROUND 12Z-13Z WITH MVFR VSBYS AND IFR CIGS DEVELOPING
AROUND 18Z AS THE SNOW LIFTS FURTHER NORTH. VSBYS SHLD THEN LOWER TO
IFR BY 20Z AND SHLD PERSIST TIL AROUND 02Z. VSBYS SHLD IMPROVE TO
VFR AFTER 02Z BUT IFR CIGS SHLD PERSIST THROUGH THE END OF THE TAF
PERIOD.
OUTLOOK...
LATER TUESDAY NIGHT THROUGH WEDNESDAY...MAINLY MVFR IN CIGS.
SCATTERED SNOW SHOWERS EAST AND SOUTHEAST OF LAKE ONTARIO.
WEDNESDAY NIGHT THROUGH FRIDAY...MAINLY VFR.
SATURDAY...DETERIORATING TO IFR/MVFR IN RAIN. LLWS POSSIBLE.
&&
.MARINE...
MODERATE NORTHWEST WINDS WILL CONTINUE TONIGHT THROUGH WEDNESDAY
WITH SMALL CRAFT ADVISORY CONDITIONS ON BOTH LAKES ERIE AND ONTARIO
THROUGH MIDWEEK. THE WINDS WILL SUBSIDE BY THURSDAY AS WARMER AIR
MOVES INTO THE LOWER LAKES AND REDUCES INSTABILITY IN THE MARINE
BOUNDARY LAYER.
&&
.CLIMATE...
ROCHESTER FINALLY BREAKS THE MONTHLY MAXIMUM SNOWFALL RECORD FOR
DECEMBER. AT THE ROCHESTER INTERNATIONAL AIRPORT 0.2 TENTHS OF AN
INCH OF SNOW FELL SUNDAY DECEMBER 26TH. WITH THIS SNOW...A NEW MARK
FOR SNOWIEST DECEMBER ON RECORD HAS BEEN SET. AS OF 100 PM THIS
AFTERNOON...THE TOTAL MONTHLY SNOW TO DATE IN ROCHESTER STANDS AT
46.4 INCHES. THE OLD RECORD OF 46.2 INCHES WAS SET BACK IN
DECEMBER OF 2008. RECORDS FOR SNOWFALL GO BACK TO 1884-1885 FOR
ROCHESTER, NY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 9 PM EST WEDNESDAY FOR
LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR LOZ042.
&&
$$
SYNOPSIS...WCH
NEAR TERM...WCH
SHORT TERM...HITCHCOCK
LONG TERM...APFFEL/HITCHCOCK
AVIATION...HITCHCOCK/JJP/THOMAS
MARINE...WCH
CLIMATE...APFFEL
