FXUS61 KBUF 301203
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
703 AM EST MON NOV 30 2009
.SYNOPSIS...
A NORTHWEST FLOW OF COLDER AIR BEHIND THE PASSAGE OF A COLD FRONT
EARLY THIS MORNING WILL OVERSPREAD THE REGION TODAY AS HIGH PRESSURE
BUILDS EAST FROM THE CENTRAL GREAT LAKES AND OHIO VALLEY THIS
AFTERNOON. A TROUGH OVER THE CENTRAL LAKES LATE TONIGHT IS EXPECTED
TO MOVE EAST AND BRING A THREAT OF PRECIPITATION LATE TONIGHT AND
TUESDAY THAT WILL BE ENHANCED NEAR LAKE ERIE AND EAST OF LAKE
ONTARIO. A WARM FRONT OVER THE LOWER LAKES EARLY WEDNESDAY WILL LIFT
NORTH OF LAKE ONTARIO WEDNESDAY AFTERNOON.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS WILL BE A TRANSITION PERIOD WITH SOME IMPORTANT LAKE EFFECT
CONSIDERATIONS BEFORE DAYBREAK TUESDAY.
AS OF 08Z A DEEPENING SURFACE LOW WAS OVER NORTHERN NEW YORK AND
VERMONT. THE ASSOCIATED COLD FRONT EXTENDED SOUTHWEST FROM THE LOW
TO SYRACUSE TO NEAR PITTSBURGH. THE BAD NEWS IS THAT COLDER AIR WILL
BE BUILDING IN DURING THE DAY BUT THE GOOD NEWS IS THAT THE
PRECIPITATION SHIELD ASSOCIATED WITH THE FRONT WILL EXIT FAIRLY
QUICKLY TO THE EAST. IT WILL PROBABLY BE DONE ACROSS THE NIAGARA
FRONTIER BY 7 TO 8 AM AND THE FINGER LAKES BY MID MORNING. LAKE
INSTABILITY AND UPSLOPE WILL FORCE US TO KEEP A CHANCE OF MIXED RAIN
AND SNOW SHOWERS ACROSS CHAUTAUQUA AND CATTARAGUS COUNTIES THROUGH
THE DAY ALONG WITH MORE CLOUD COVER...WHILE PARTIAL CLEARING IS
LIKELY ELSEWHERE AS A SURFACE RIDGE NOSES IN FROM THE OHIO VALLEY.
TEMPERATURES WILL BE RATHER STEADY AS COLD ADVECTION BALANCES
DIURNAL AFFECTS. COLDER ACROSS THE SOUTHWEST PART OF THE STATE WHERE
CLOUD COVER WILL BE MORE.
TONIGHT WILL GET VERY INTERESTING AND BECOMES A REAL FORECAST
CHALLENGE. A SHORT WAVE WILL DIVE SOUTHEAST FROM THE CENTRAL LAKES
WITH A RESULTING SURFACE TROUGH SWINGING TOWARD OUR REGION. THERE
ARE MODEL DIFFERENCES BUT IT LOOKS FAIRLY CERTAIN THE THE STEERING
WINDS IN THE LOW LEVELS OF THE ATMOSPHERE WILL TARGET THE NIAGARA
FRONTIER. AT THIS TIME THE MESO SCALE MODELS AND THE NAM12 WOULD
PUSH LAKE EFFECT ACTIVITY AS FAR NORTH AS BUFFALO AND BATAVIA AND
MAYBE AS FAR NORTH AS NIAGARA FALLS. WE WILL PUT IN 2 TO 3 INCHES IN
THE HEAVIEST AREAS BY MORNING. SURFACE TEMPERATURES NEAR OR JUST
BELOW FREEZING MAY CAUSE SOME MORNING RUSH HOUR TRAVEL PROBLEMS. NO
ADVISORIES AT THIS TIME BUT THIS WILL HAVE TO BE WATCHED.
ANYTHING OFF LAKE ONTARIO WILL WAIT UNTIL DAYBREAK OR AFTER.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
TUESDAY, THE SFC TROUGH MOVES EAST ACROSS THE AREA IN THE MORNING.
WINDS WILL BE SW ENOUGH AHEAD OF THE TROUGH IN THE MORNING TO BRING
SOME LK ENHANCED SNOW TO THE BUF METRO AREA TUESDAY MORNING THEN
THEY SHOULD BECOME A BIT MORE WESTERLY BEHIND THE TROUGH AFT 15Z OR
SO AND PUSH MOST OF THE PRECIP SOUTH OF THE METRO AREA WHERE IT SHLD
WEAKEN IN THE AFTERNOON AS BUFKIT PROFILES SHOW THE INVERSION
CRASHING DURG THE COURSE OF THE AFTERNOON. ANOTHER INCH OR TWO OF
SNOW IS POSSIBLE IN THE MORNING IN THE BUFFALO METRO AREA TO BATAVIA
BEFORE IT MOVES SOUTH WITH ANOTHER INCH OR TWO ACROSS THE HILLS
SOUTH OF BUFFALO TO THE SOUTHERN TIER. SOME OF THE LAKE ENHANCED
PRECIP OFF LK ERIE IS EXPECTED TO GET AS FAR EAST AS THE ROCHESTER
AREA. WILL CARRY LKLY POPS EAST TO THE ROC AREA IN THE MORNING WHERE
THEY COULD GET A COATING TO LESS THAN AN INCH
BNDRY LYR TEMPS SHLD MODERATE ENOUGH IN THE AFTERNOON FOR ANY PRECIP
TO BE MNLY RAIN EXCEPT FOR A PSBL MIX STILL ACROSS THE HIGHEST
TERRAIN OF THE SOUTHERN TIER.
EAST OF LK ONTARIO, THE MM5 SHOWS THE SITUATION SHLD BE SIMILAR WITH
THE ACTIVITY BEING ENHANCED NE OF THE LK FRM ART NORTHWARD THROUGH
18Z AND THEN THAT AREA WEAKENING WITH ANOTHER DEVELOPING FURTHER
SOUTH AROUND OSWEGO COUNTY FRM ARND 18Z-21Z AND THEN SETTLING SOUTH
INTO SOUTHERN OSWEGO AND NORTHERN CAYUGA COUNTY BY EVENING. THE
SYR PROFILE SHOWS THE INVERSION LOWERING RAPIDLY TUES NGT.
BNDRY LYR TEMPS SHLD WARM ENOUGH FOR RAIN OR RAIN/SNOW MIX BY MIDDAY
AND AFTERNOON ACROSS LOWER ELEVATIONS. SNOW ACCUMS OF AN INCH OR TWO
ARE POSSIBLE. HIGHS TUESDAY SHLD GENLY RANGE FROM THE UPPER 30S TO
LOWER 40S.
WILL CONTINUE CHC POPS TUESDAY NIGHT ACROSS PORTIONS OF THE
EASTERN LK ONTARIO REGION SOUTH OF WATERTOWN MNLY FROM THE SOUTHERN
TWO THIRDS OF LEWIS COUNTY SOUTH TO NORTHERN CAYUGA AND NORTHEAST
PORTIONS OF WAYNE COUNTY. ELSEWHERE UPPER RIDGING...SOUTHWESTERLY
WINDS AND WARMING WILL BRING AN END TO THE LAKE EFFECT AND BRING
PARTIAL CLEARING TUESDAY NIGHT TO AREAS SOUTH OF THE THRUWAY.
LOWS TUESDAY NGT SHLD RANGE FROM 25 TO 30 ACROSS THE SOUTHERN TIER
AND ACROSS AREAS EAST OF LK ONTARIO TO LOWER 30S ACROSS THE FINGER
LKS AND NIAGARA FRONTIER.
ON WEDNESDAY AS A WARM FRONT LIFTS NORTH OF LAKE ONTARIO WE SHLD SEE
A PERIOD OF PTLY TO MSTLY SUNNY SKIES BUT SOME CLOUDS WILL LINGER
ACROSS THE NORTH COUNTRY EARLY IN THE MORNING DUE TO THE WARM FRONT.
EXPECT CLOUDS TO INCREASE FROM THE SOUTHERN TIER NORTHWARD DURG THE
AFTERNOON AS MOISTURE AHEAD OF A STORM SYSTEM OVER THE SOUTHEASTERN
STATES SPREADS NORTHWARD. AT THIS TIME GOING MORE TWD ECMWF AND AND
ONLY BRINGING IN LOW CHC OF RAIN LATE IN THE DAY NEAR THE NY/PA
BORDER. HIGHS WED SHLD REBOUND AGAIN TO THE MID TO UPPER 40S AS THE
HIGH OFF THE COAST SENDS A SE FLOW OF MILDER AIR NORTHWARD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A SPLIT FLOW OVER THE EASTERN HALF OF COUNTRY WEDNESDAY MORNING WILL
PHASE INTO A FAIRLY DEEP LONG WAVE TROUGH OVER THE GREAT LAKES
REGION BY FRIDAY. THIS WILL RESULT IN A CHANGE TO COLDER...MORE
SEASONABLE CONDITIONS THAT WILL PERSIST THROUGH THE WEEKEND. THIS
WILL LIKELY LEAD TO MORE SNOW AS WELL...AND POSSIBLY SOME
SIGNIFICANT LAKE EFFECT ACTIVITY.
THE CLOSED LOW OVER THE TEXAS/LOWER MISSISSIPPI VALLEY WEDNESDAY IS
EXPECTED TO OPEN UP BY WEDNESDAY EVENING...WITH A SFC WAVE DEEPENING
AS IT LIFTS UP ALONG THE SPINE OF THE APPALACHIANS. THIS WILL SEND A
SURGE OF MOISTURE UP ACROSS THE MID ATLANTIC STATES TO OUR REGION...
ALONG WITH RELATIVELY MILD AIR. HAVE RAISED SFC TEMPS BY SOME 3 TO 6
DEG F FOR WEDNESDAY NIGHT AS THE GEFS...OPERATIONAL GFS AND ECWMF
BRING THE SFC LOW UP ACROSS PENNSYLVANIA. WHILE THE ECMWF IS SOME
100 MILES 'SLOWER' THAN THE GEFS AND OPERATIONAL GFS...IT IS ALSO
FAVORING A WARM ADVECTION PATTERN ALOFT. THE GEFS MEAN H85 TEMP OVER
THE FINGER LAKES REGION AT 06Z THURS IS AROND ZERO C WITH FAIRLY
STRONG WAA EXPECTED FROM THAT POINT INTO THE EARLY DAYLIGHT HOURS OF
THURSDAY.
AS A RESULT...HAVE BACKED OFF ON THE FROZEN/FREEZING PCPN FOR
WEDNESDAY NIGHT AND HAVE SIMPLY MADE THE P-TYPE AS RAIN. POPS FOR
WEDN NIGHT HAVE ALSO BEEN RAISED A LITTLE TO HIGH LIKELY (FROM CHC).
DURING THE COURSE OF THURSDAY AS THE TWO MAIN JETS PHASE OVER THE
OHIO VALLEY...A SUB 990MB LOW WILL CONTINUE TO LIFT AND DEEPEN ACROS
NEW ENGLAND. COLDER AIR ON ITS BACKSIDE WILL POUR ACROSS OUR REGION
AND CHANGE THE RAIN TO SNOW...WITH BOTH THE ECMWF AND GEFS
SUGGESTING A PROLONGED DEFORMATION ZONE DRAGGING ACROSS THE BULK OF
THE REGION. THIS TRAILING MID LEVEL DEFORMATION ZONE WILL BE FROM
WESTERN TO NORTHERN NEW YORK AND COULD BRING AN ACCUMULATING
SYNOPTIC SNOW AS ECMWF QPF RANGES NEAR THREE QUARTERS OF AN INCH
/LIQUID/ WHICH WOULD TRASNLATE INTO SEVERAL INCHES OF SNOW.
AS THE SURFACE LOW LIFTS NORTHWARD ACROSS WESTERN QUEBEC ON THURSDAY
NIGHT...THE FLOW ON THE WESTERN SIDE OF THE LOW WILL DRAW MUCH
COLDER AIR INTO NEW YORK STATE DURING THURSDAY NIGHT...DEEPENING AND
GETTING COLDER ON FRIDAY. THIS COULD SPELL THE BEGINNING OF A WELL
DEVELOPED LAKE EFFECT SNOW EVENT WITH 850MB TEMPS FALLING TO A RANGE
FROM -10C TO -12C BY LATE FRIDAY MORNING.
THE WEEKEND WILL SEE A MORE ZONAL FLOW DEVELOPING BUT 850MB TEMPS
WILL HOVER AT OR BELOW ZERO THROUGH THE WEEKEND. CHANCE POPS EACH
DAY WILL OFFER SOME NIGHTTIME SNOW SHOWERS AND DAYTIME RAIN SHOWERS
OR A RAIN/SNOW MIX AT HIGHER ELEVATIONS.
COLDER TEMPS ARE EXPECTED THROUGH THE REST OF THE WEEK WITH LOWS IN
THE MID TO UPPER 20S AND HIGHS ONLY IN THE MID TO UPPER 30S. THE
WEEKEND MAY SEE A MODERATING TREND WITH HIGHS IN THE UPPER 30S TO
NEAR 40 ON SATURDAY AND TO THE LOWER 40S ON SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 11Z A LOW WAS CENTERED OVER NORTHERN VERMONT WITH A COLD
FRONT EXTENEDING SOUTHWEST ACROSS EASTERN NEW YORK AND CENTRAL
PENNSYLVANIA. THE BACK EDGE OF THE PRECIPITATION RAN FROM JUST
WEST OF WATERTOWN TO NEAR JAMESTOWN. MVFR TO OCNL IFR CONDITIONS
WILL IMPROVE IN MOST AREAS TO VFR AS A RIDGE OF HIGH PRESSURE
BUILDS EAST. A COLD NORTHWEST FLOW OFF LAKE ERIE WILL KEEP KJHW
MVFR.
A SECONDARY TROUGH DIVING SOUTHEAST FROM THE CENTRAL LAKES WILL
BACK THE WINDS TO SOUTHWEST LATE TONIGHT. THE LOWER ATMOSPHERE
WILL BE COLD ENOUGH FOR LAKE EFFECT SNOW. AT THIS TIME IT LOOKS
LIKE THE STEERING WINDS WILL BACK ENOUGH FOR IFR CONDITIONS TO
REACH AT LEAST AS FAR NORTH AS KBUF AND MAYBE KIAG DURING THE LAST
3 OR 4 HOURS OF THE TAF PERIOD.
OUTLOOK...
MONDAY NIGHT...MVFR WITH SCATTERED SNOW SHOWERS. LOCAL IFR/LIFR IN
LAKE EFFECT SNOW EAST OF LAKE ERIE.
TUESDAY...VFR/MVFR WITH CHANCE RAIN/SNOW SHOWERS. LOCAL IFR/LIFR IN
LAKE EFFECT SNOW/RAIN THE MORNING EAST OF LAKES ERIE AND ONTARIO.
WEDNESDAY...VFR.
THURSDAY...MVFR/IFR. CHANCE OF RAIN AND SNOW.
FRIDAY...MVFR. CHANCE OF SNOW. LOCAL IFR/LIFR IN LAKE EFFECT SNOW
EAST OF LAKES ERIE AND ONTARIO.
&&
.MARINE...
HAVE ISSUED SMALL CRAFT ADVSRYS FOR LATE TONIGHT INTO TUESDAY
MORNING AS SW WINDS INCREASE AHEAD OF THE TROUGH WITH TEH WINDS
SHIFTING TO THE WEST BEHIND THE TROUGH TUESDAY AFTERNOON.
ON LAKE ONTARIO NW WINDS BEHIND THE COLD FRONT LATER TODAY COOULD
BRING WAVES CLOSE TO SMALL CRAFT ADVSRY RANGE LATE THIS AFTERNOON
INTO THIS EVENING FOR A FEW HRS. GOING WITH 2-4 FT FOR NOW BUT THE
DAY SHIFT MAY HAVE TO ISSUE ONE LATER TODAY.
&&
.CLIMATE...
STILL NO MEASURABLE SNOW SO FAR THIS SEASON OVER MOST OF WESTERN NEW
YORK. WE ARE ALREADY OVER THREE WEEKS LATE (NORMAL DATES ARE NOV 7
FOR BUFFALO AND NOV 8 FOR ROCHESTER). WE WILL AT LEAST GET TO MONDAY
(30TH) AND IF SO...WILL BE THE LATEST IN 63 YEARS (1946) AT
BUFFALO...AND LATEST IN 46 YEARS (1963) AT ROCHESTER. THE ALL TIME
RECORD LATEST DATES FOR FIRST MEASURABLE SNOW ARE DEC 3 1899 AT
BUFFALO AND DEC 10 1948 AT ROCHESTER.
IN ADDITION, ITS BEEN A LONG TIME SINCE EITHER BUFFALO OR ROCHESTER
LAST SAW MEASURABLE SNOW. THROUGH YESTERDAY NOV 29...BUFFALO HAS GONE
236 DAYS WITHOUT MEASURABLE SNOW, OR SINCE APRIL 7, 2009. THIS IS
THE 4TH LONGEST STRETCH IN 125 YEARS OF RECORDS. THE RECORD IS 277
DAYS SET BACK IN 1946. ROCHESTER IS ALSO AT 236 DAYS WITHOUT
MEASURABLE SNOW, OR THE 3RD LONGEST STRETCH THERE. THE RECORD IS
260 DAYS SET BACK IN 1952.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM TO 4 PM EST TUESDAY FOR LEZ020-
040-041.
&&
$$
SYNOPSIS...JJP
NEAR TERM...SAGE
SHORT TERM...JJP
LONG TERM...JJP/RSH/WCH
AVIATION...HITCHCOCK/SAGE
MARINE...JJP
CLIMATE...TMA/SAGE
