FXUS61 KBUF 290447
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1147 PM EST SAT NOV 28 2009
.SYNOPSIS...
DEEP LOW PRESSURE WILL MOVE NORTHEAST TO THE CANADIAN MARITIMES
TODAY WHILE HIGH PRESSURE BUILDS NORTHEAST FROM THE SOUTHEASTERN
STATES THROUGH TONIGHT. TEMPERATURES WILL MODERATE A BIT SUNDAY AS A
WEAK LOW MOVES EAST FROM THE CENTRAL LAKES REGION. A COLD FRONT
ASSOCIATED WITH THIS SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT
AND MOVE OFF THE COAST MONDAY FOLLOWED BY A SHOT OF COLDER AIR.
&&
.NEAR TERM /THROUGH SUNDAY/...
KTYX RADAR IMAGERY STILL SHOWS A NARROW/WEAK BAND OF LAKE ENHANCED
RAIN SHOWERS ACROSS THE SOUTHERN HALF OF THE TUG HILL...BEING AIDED
BY UPSLOPE FLOW. CONDITIONS WILL REMAIN SUFFICIENT FOR THIS TO
PERSIST THROUGH ABOUT MIDNIGHT BEFORE WARM ADVECTION ALOFT CRASHES
THE INVERSION AND REMOVES ANY REMAINING LAKE INDUCED INSTABILITY.
HAVE INCLUDED A VERY NARROW AREA OF SCATTERED SHOWERS IN GRIDS AND
DIGITAL FORECAST FOR THE WEB THROUGH MIDNIGHT. MESONET TEMPERATURES
SUGGEST MOST IF NOT ALL OF THIS SHOULD REMAIN LIQUID WITH SURFACE
TEMPS STILL IN THE UPPER 30S.
OTHERWISE CLEARING IS ADVANCING RAPIDLY EAST ACROSS THE CWA THIS
EVENING WITH CLEAR SKIES ALL THE WAY TO THE GENESEE VALLEY AT 02Z.
EXPECT THIS CLEARING LINE TO SLOW AS IT REACHES THE EASTERN LAKE
ONTARIO REGION OWING TO SOME LINGERING LAKE EFFECT CLOUDS. THE 12Z
MODEL GUIDANCE SUGGESTED SOME ADDITIONAL LOW CLOUD MAY DEVELOP
ACROSS THE SOUTHERN TIER AND SPREAD NORTH LATE TONIGHT AND SUNDAY
MORNING. LATEST 18Z NAM/GFS POINT SOUNDINGS ARE MUCH LESS AGGRESSIVE
IN LOW LEVEL MOISTURE RETURN. EVEN THIS APPEARS OVERDONE...AND FEEL
THE MET/MAV GUIDANCE AND MODEL POINT SOUNDINGS ARE STILL TOO
PESSIMISTIC WITH CLOUD COVER TONIGHT THROUGH THE FIRST HALF OF
SATURDAY. GRIDS/ZFP HAVE BEEN ADJUSTED TO GO WITH MAINLY CLEAR SKIES
TONIGHT FROM WAYNE COUNTY WEST...AND MOSTLY SUNNY EVERYWHERE BUT THE
NORTH COUNTRY FOR SUNDAY MORNING.
WITH CLEARING SKIES AND DIMINISHING WINDS...RADIATIONAL COOLING WILL
ALLOW TEMPS TO FALL BELOW GUIDANCE TONIGHT. DROPPED FORECAST LOWS BY
SEVERAL DEGREES OVERNIGHT...AND EXPECT MOS GUIDANCE TO BE OF LITTLE
USE GIVEN ITS POOR HANDLE ON CLEARING SKIES.
SUNDAY LOOKS TO START OUT DRY WITH MOSTLY SUNNY SKIES. CLOUDS LOOK
TO INCREASE AND THICKEN IN THE AFTERNOON AS A SOUTHWESTERLY FLOW OF
INCREASINGLY MOIST AIR ADVECTS INTO THE REGION AHEAD OF A WARM FRONT
LIFTING ACROSS THE GREAT LAKES. ASSOCIATED SURFACE WAVE PUSHING
ALONG THE FRONT SHOULD MOVE TO A POSITION BETWEEN CLEVELAND AND
TORONTO BY THE END OF THE DAY. FRONTAL LIFT AND MOISTURE ADVECTION
WILL RESULT IN AN INCREASING CHANCE OF SHOWERS BY LATE AFTERNOON
ACROSS WESTERN NY AND THE SAINT LAWRENCE VALLEY. HIGHS SHOULD BE
CLOSE TO 10 DEGREES ABOVE NORMAL WITH SSW DOWNSLOPE FLOW ALLOWING
TEMPS TO CLIMB INTO THE LOWER 50S ACROSS THE LOWER ELEVATIONS...WITH
UPPER 40S ACROSS HIGHER TERRAIN AND EAST OF LAKE ONTARIO.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SUNDAY NIGHT, AS THE LOW PASSES BY JUST TO OUR NORTH THE TRAILING
COLD FRONT CROSSES THE REGION AND MOVES TO EASTERN NY BY MONDAY
MORNING. WILL INCREASE POPS TO THE LIKELY RANGE WITH THE FRONTAL
PASSAGE AND THEN LOWER THE POPS TO THE CHC RANGE LATER AT NIGHT
ACROSS AREAS FROM THE FINGER LAKES WEST. VERY LATE SUNDAY NIGHT THE
AIR GETS COLD ENOUGH, AROUND -3 TO -5C AT 850 BY 12Z SUNDAY, SO
PRECIP SHOULD MIX OR CHANGE TO SNOW ACROSS INLAND AREAS EXCEPT FOR
THE LAKE PLAINS AND OVER LOWER ELEVATIONS ACROSS THE FINGER LAKES
AND EASTERN LK ONTARIO REGIONS. TEMPS ON SUNDAY NIGHT WILL DIP
SLIGHTLY IN THE EVENING THEN RISE AHEAD OF THE APPROACHING FRONT
WITH AN EARLY NIGHT LOW IN THE MID TO UPPER 30S.
ON MONDAY, EXPECT TEMPERATURES TO REMAIN NEARLY STEADY DURING EARLY
MONDAY MORNING...THEN FALL IN THE AFTERNOON AS THE COLD AIR
OVERSPREADS WESTERN NY. EXPECT EARLY MORNING HIGHS GENERALLY FROM
THE UPPER 30S TO AROUND 40 AND AFTERNOON TEMPERATURES IN THE LOWER
TO MID 30S...AROUND 30 EAST OF LAKE ONTARIO. THE MID LEVEL TROUGH
WILL MOVE THROUGH THE AREA DURING THE DAY AND THE AIR WILL BE COLD
ENOUGH FOR SOME LAKE ENHANCEMENT EAST OF THE LAKES SO WILL CONTINUE
WITH CHC RAIN/SNOW SHWRS TRENDING TO ALL SNOW...WITH HIGHEST CHANCES
EAST OF THE LAKES IN FAVORED UPSLOPE AREAS DUE TO WESTERLY FLOW.
TEMPERATURES FALL TO THE 20S MONDAY NIGHT WITH SOME LAKE SNOWS
EXPECTED TO THE EAST OF THE LAKES...POPS IN THE LIKELY RANGE ALONG
THE CHAUTAUQUA RIDGE AND THE SOUTHEASTERN CORNER OF LAKE ONTARIO TO
THE SOUTHERN TUG HILL PLATEAU.
TUESDAY WILL CHARACTERIZED BY COLD TEMPS IN THE 30S AND SCATTERED
RAIN/SNOW SHOWERS IN THE LOWER ELEVATIONS AND SCATTERED TO LIKELY
SNOW SHOWERS IN THE HILLS OF THE SOUTHERN TIER AND THE TUG HILL
PLATEAU. UPPER RIDGING...SOUTHWESTERLY WINDS AND WARMING WILL BRING
AN END TO THE LAKE EFFECT AND BRING PARTIAL CLEARING TUESDAY NIGHT.
IT WILL STILL BE QUITE COLD WITH OVERNIGHT LOWS IN THE MID 20S OVER
MOST OF THE FORECAST AREA WITH SOME LOWER 30S ALONG THE LAKE ERIE
SHORELINE AREAS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGH PRESSURE PASSES THE REGION TO THE SOUTH WITH A NORTHWARD
EXTENSION OF THE RIDGE COVERING THE EASTERN LAKES AND NORTHEASTERN
STATES. SKIES WILL NOT CLEAR COMPLETELY DUE TO THE MOISTURE
ADVECTING IN FROM THE SOUTH...BUT WE CAN EXPECT SOME SUNSHINE AND
TEMPS IN THE MID 40S...A COUPLE OF DEGREES ABOVE SEASONAL NORMALS.
A PLAINS CLOSED UPPER LOW WILL OPEN AND LIFT ALONG THE WESTERN
APPALACHIANS DURING WEDNESDAY AFTERNOON AND SPREAD PRECIP INTO THE
FORECAST AREA DURING WEDNESDAY NIGHT. THIS TRACK IS ABOUT 200 MILES
FARTHER INLAND ON TODAY'S 12Z GFS THAN ON PREVIOUS MODEL RUNS...AND
WILL BRING A MIX OF RAIN AND SNOW TO THE AREA DURING THE NIGHT AS A
WARM JET BOOSTS THE 850MB TEMPS CLOSE TO THE FREEZING MARK OVER THE
GENESEE VALLEY AND FINGER LAKES BETWEEN 09Z AND 15Z...THEN BACK
BELOW FREEZING FOR MUCH OF THE DAYTIME ON THURSDAY. WILL HAVE SOME
MIXED PRECIP IN THE LATE NIGHT AND EARLY MORNING...THEN A MIX OF
SNOW SHOWERS AND SOME SLEET AS THE SHALLOW WEDGE OF WARMER AIR IS
UNDERLAIN BY COLDER AIR. THIS COMBINATION OF PRECIP TYPE MAY CHANGE
IF THE NEWER MODELS SHIFT THE TRACK OF THE SURFACE LOW EITHER CLOSER
TO THE COAST WHICH WILL MAINTAIN COLDER AIR AND ALL SNOW...OR
FARTHER WEST WHICH WOULD BRING RAIN RATHER THAN SNOW.
AS THE SURFACE LOW LIFTS NORTHWARD INTO WESTERN QUEBEC ON THURSDAY
EVENING...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. WILL HAVE UPPER CHANCE TO
LOW LIKELY POPS IN THE LEE OF THE LAKES FOR FRIDAY AND CHANCE POPS
THROUGH SATURDAY MORNING.
WEDNESDAY WILL BE THE MILDEST DAY OF THE WORKWEEK WITH HIGHS IN THE
LOWE TO MID 40S...THEN COLDER TEMPS THROUGH THE REST OF THE WEEK
WITH LOWS IN THE MID TO UPPER 20S AND HIGHS ONLY IN THE MID TO UPPER
30S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
11-3.9 MICRON SATELLITE SHOWS STRATUS QUICKLY ERODING ACROSS MUCH OF
WESTERN NY WITH THE CLEARING LINE ACROSS THE EAST END OF LAKE
ONTARIO INTO WAYNE COUNTY. EXPECT SKC AT ALL OF THE WESTERN NY TAF
SITES THROUGH SUNDAY MORNING. FARTHER EAST AT KART THE STRATUS DECK
WILL BE MORE DIFFICULT TO DISLODGE WITH MOIST CYCLONIC FLOW
PERSISTING WITH SOME AID FROM LAKE EFFECT CLOUDS. EXPECT A BKN-OVC
LOWER END VFR DECK TO REMAIN THROUGH SUNDAY MORNING BEFORE
SCATTERING OUT.
BY LATE SUNDAY THE NEXT SYSTEM WILL APPROACH THE LOWER GREAT LAKES.
EXPECT ALL OF THE DAYLIGHT HOURS TO REMAIN VFR...WITH SHOWERS
ARRIVING DURING THE EVENING. CIGS SHOULD LOWER TO MVFR DURING THE
EVENING AS THE SHOWERS MOVE IN. BY AROUND MIDNIGHT THE APPROACH OF
THE SURFACE COLD FRONT MAY BRING A FURTHER DETERIORATION TO IFR CIGS
WITH MOIST SOUTHWEST FLOW ALIGNING WITH LAKE ERIE AND THE SURFACE
COLD FRONT. THIS WOULD MOST LIKELY IMPACT KBUF-KIAG INITIALLY. LOWER
END MVFR OR IFR CIGS MAY SPREAD TO THE OTHER TAF SITES AS WELL AFTER
THE 06Z END TIME OF THIS TAF CYCLE.
OUTLOOK...
MONDAY...MVFR. CHANCE RAIN/SNOW SHOWERS.
MONDAY NIGHT...MVFR WITH SCATTERED SHOW SHOWERS. LOCAL IFR/LIFR IN
LAKE EFFECT SNOW EAST OF LAKES ERIE AND ONTARIO.
TUESDAY...VFR/MVFR. CHANCE RAIN/SNOW SHOWERS.
WEDNESDAY...MAINLY VFR.
THURSDAY...MVFR. CHANCE OF RAIN AND SNOW.
&&
.MARINE...
SMALL CRAFT ADVISORIES WILL BE CONTINUED INTO TONIGHT ACROSS THE
NEARSHORE WATERS OF THE LAKES. SMALL CRAFT ADVISORIES WILL BE DROPPED
AT VARYING INTERVALS TONIGHT FOR THE LAKES AS WINDS AND WAVES DROP
BELOW SMALL CRAFT ADVISORY RANGE. BY 12Z SUNDAY A BROAD BUT WEAK
RIDGE OF HIGH PRESSURE WILL BUILD IN ACROSS THE EASTERN LAKES
LOWERING WIND AND WAVE CONDITIONS. SOUTHWEST WINDS AHEAD OF THE
NEXT LOW ON SUNDAY WILL INCREASE ENOUGH FOR MORE SMALL CRAFT
ADVISORIES SUNDAY AFTERNOON AND SUNDAY EVENING. BEHIND THE COLD FRONT
LATER SUNDAY NIGHT NW WINDS WILL INCREASE TO SMALL CRAFT ADVERSE
RANGE.
&&
.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 TODAY NOV 28...BUFFALO HAS GONE
235 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 235 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 UNTIL 1 AM EST SUNDAY FOR LOZ043.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...WCH
NEAR TERM...HITCHCOCK/TMA
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...HITCHCOCK
MARINE...TMA/WCH
CLIMATE...TMA
