FXUS61 KBUF 040601
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
101 AM EST FRI DEC 4 2009
.SYNOPSIS...
STRONG LOW PRESSURE WILL CONTINUE TO MOVE EAST OF NEW ENGLAND.
COLDER AIR BUILD IN BEHIND THE LOW BRINGING ACCUMULATING LAKE EFFECT
SNOWS LATE TONIGHT THROUGH FRIDAY NIGHT. THE LAKE EFFECT SNOW WILL
SLOWLY DIMINISH DURING SATURDAY. HIGH PRESSURE WILL BUILD OVER THE
REGION SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH 900 PM...PRECIPITATION IS GENERALLY CONFINED TO SCATTERED
SHOWER ACTIVITY SOUTHEAST OF BUFFALO. AS WINDS HAVE
DIMINISHED...SO HAS UPSLOPING ACTIVITY...WITH EVEN A FEW BREAKS IN
THE CLOUDS SHOWING UP ACROSS EASTERN PARTS OF LAKE ERIE AND
ONTARIO. FEEL MOST PRECIPITATION IS RAIN SHOWERS...EXCEPT OVER
1500 FT...BUT WITH TEMPERATURES DROPPING...IT SHOULD BE COLD
ENOUGH FOR SNOW IN MOST LOCATIONS BY OR SHORTLY AFTER MIDNIGHT.
THE MAIN EVENT STILL LIES SEVERAL HOURS AWAY...AS SHOWER ACTIVITY
DEVELOPS ACROSS WESTERN PORTIONS OF LAKE ERIE. RADAR LENDING
SUPPORT TO THE 18Z WRF AND 00Z NAM...AS BOTH ARE FAIRLY CLOSE WITH
THIS. THIS AREA SHOULD TRACK NORTHEAST...EVENTUALLY BLOSSOMING INTO
THE LAKE EFFECT SNOW EVENT FOR THE BUFFALO METRO AREA ON FRIDAY.
INITIALLY...THE FLOW IS MORE WESTERLY...WITH THE BAND INITIALLY
EXPECTED TO SET UP IN CHAUTAUQUA AND SOUTHERN ERIE
COUNTIES...EXTENDING INLAND DUE TO UPSLOPING. AFTER CONSULTING 18Z
RUNS OF THE NAM/WRF/RUC...BASICALLY FEEL ALL THESE MODELS HAVE A
GENERALLY HANDLE ON THE SITUATION...WITH A BLEND YIELDING A
REASONABLE STARTING POINT FOR QPFS OVERNIGHT. FEEL WINDS WILL
LIKELY SHIFT SW QUICKER THAN THESE MODELS RESOLVE...AS THE WEST
FLOW HITS THE CHAUTAUQUA RIDGE...IT SEEM TO FUNNEL SW A BIT
QUICKER THAN MODELS OFTEN SHOW. THUS TWEAK WINDS (AND QPF/SNOW) A
BIT TOWARDS THIS...DIMINISHING INLAND QPFS AND PUSHING IT A TAD
NORTH. THIS METHOD GENERALLY AGREES WITH GOING FORECAST IN THE
SOUTHERN TIER...AND THIS NUDGES UP THE START TIME IN BUFFALO
A BIT...POTENTIALLY ENOUGH TO IMPACT THE MORNING COMMUTE. GOING
SNOWFALL TOTALS IN THE WARNING AND ADVISORY AREAS STILL LOOK ON TRACK.
AS THE COLDER AIR CONTINUES TO DEEPEN THIS EVENING AND TONIGHT...THE
MAIN FOCUS WILL SHIFT TO LAKE EFFECT SNOW AS 850 MB TEMPERATURES
COOL TO ABOUT -7C BY FRIDAY MORNING. EXPECT THE BULK OF THE LAKE
EFFECT SNOW TO IMPACT THE SOUTHERN TIER OVERNIGHT WITH POSSIBLE
ACCUMULATIONS OF 2 TO 4 INCHES.
ON FRIDAY...THE BOUNDARY LAYER WINDS WILL BACK MORE TO THE SOUTHWEST
AS A MID LEVEL TROUGH DEEPENS ACROSS THE CENTRAL GREAT LAKES. THIS
WILL ALLOW ANY ONGOING LAKE EFFECT SNOW BANDS TO SHIFT TO THE NORTH
AND SET UP ACROSS THE NIAGARA FRONTIER. WHILE THE NAM12 PROFILES DO
NOT SHOW A REAL DEEP LAYER OF MOISTURE OR IDEAL SNOW CRYSTAL
GROWTH...THE MAIN CONCERN IS THAT THE SNOW BANDS WILL REMAIN
STEADY STATE FOR A GOOD PART OF THE DAY...ESPECIALLY IMPACTING
NORTHERN ERIE... SOUTHERN NIAGARA AND WESTERN ORLEANS AND GENESEE
COUNTIES. BASED ON THIS ANTICIPATED TREND...WE HAVE DECIDED TO
ISSUE A LAKE EFFECT SNOW WARNING FOR NORTHERN ERIE COUNTY...WITH
LAKE EFFECT SNOW ADVISORIES IN EFFECT FOR THE OTHER THREE
COUNTIES.
WE EXPECT THE LAKE SNOWS TO HAVE A SIGNIFICANT IMPACT ON THE LATE
AFTERNOON/EARLY EVENING RUSH HOUR TRAFFIC IN METRO BUFFALO. AS THE
BOUNDARY LAYER WINDS VEER SLOWLY TO THE WEST SOUTHWEST...THE SNOW
BANDS ARE EXPECTED TO SETTLE INTO SOUTHERN ERIE COUNTY LATE IN THE
DAY.
EAST OF LAKE ONTARIO...NOTICED THE 21Z RUC IN PARTICULAR SHOWS
BAND DEVELOPMENT SHORTLY AFTER 06Z IN THE WESTERLY
FLOW...IMPACTING THE TUG HILL. WITH BUF RADAR SHOWING SOME RETURNS
ACROSS CENTRAL LAKE ONTARIO...AND SOME SUPPORT FROM THE
NAM/WRF...WILL BUY THIS SOLUTION. INITIALLY...MARGINAL
TEMPERATURES WILL RESULT IN RAIN OR SNOW SHOWERS...BUT TOWARDS
DAYBREAK EXPECT LAKE EFFECT SNOW SHOWERS TO BLOSSOM A BIT IN
NORTHERN OSWEGO COUNTY AND THE TUG HILL. WINDS WILL QUICKLY SHIFT
MORE SW...SHIFTING THIS BAND NORTH...BUT DO CARRY A MENTION 1 TO 3
INCHES ON THE TUG HILL. ACCUMULATING SNOW WILL SHIFT NORTHWARD IN
THE SOUTHWEST FLOW. WITH MUCH OF THE EVENT HERE WELL INTO FRIDAY
NIGHT...WILL HOLD OFF ON ANY HEADLINES AT THIS TIME.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
LAKE EFFECT OFF LAKE ERIE...THE LAKE EFFECT SNOW BAND WILL BE
SHIFTING TO THE SOUTH FRIDAY NIGHT AND WILL PRIMARILY
IMPACTING...CENTRAL AND SOUTHERN ERIE COUNTY...INCLUDING THE
BUFFALO SOUTHTOWNS...WESTERN WYOMING COUNTY AND DOWN ACROSS
NORTHERN SECTIONS OF CHAUTAUQUA AND CATTARAUGUS COUNTIES. THIS
LAKE PLUME SHOULD STILL BE RATHER INTENSE WITH THE POTENTIAL FOR
SEVERAL INCHES OF SNOW. LAKE EFFECT SNOW HEADLINES MAY NEED TO BE
SHIFTED SOUTH INTO THESE AREAS FOR FRIDAY NIGHT.
LAKE EFFECT OFF LAKE ONTARIO...
THE LAKE EFFECT SNOW BAND WILL BE SET UP ACROSS JEFFERSON COUNTY
AT THE START OF THE PERIOD...LIKELY FROM WATERTOWN NORTHWARD. THE
LAKE PLUME SHOULD INTENSIFY FRIDAY NIGHT AS IT BEGINS TO SETTLE
FARTHER TO THE SOUTH AS THE FULL FETCH OF LAKE ONTARIO IS
REALIZED. THE POTENTIAL EXISTS FOR SEVERAL INCHES OF SNOW. LAKE
EFFECT SNOW HEADLINES MAY EVENTUALLY NEED TO BE ISSUED FOR THIS
AREA FRIDAY NIGHT.
AS SURFACE HIGH PRESSURE BUILDS OVER THE EASTERN LAKES DURING THE
DAY SATURDAY...THE BOUNDARY LAYER SHOWS MORE DRYING AND SHEAR WILL
INCREASE SIGNIFICANTLY WITH THE LAKE EFFECT SNOW BECOMING
MULTIBANDED OFF LAKE ERIE...CONTINUING INTO SATURDAY AFTERNOON OFF
LAKE ONTARIO BUT THEN BREAKING DOWN DURING THE EVENING.
THE SURFACE HIGH WILL CONTINUE TO BUILD OVER THE AREA SATURDAY NIGHT
AND SUNDAY WITH ONLY A LINGERING CHANCE FOR LAKE INDUCED SNOW
SHOWERS AS A COLD WESTERLY FLOW PERSISTS. AMOUNT OF MOISTURE AND
PRESENCE OF SHEAR ALOFT WILL LIMIT THE POTENTIAL FOR SIGNIFICANT
ACCUMULATIONS.
TEMPERATURES SATURDAY WILL RANGE FROM THE UPPER 20S OVER THE
SOUTHERN TIER TO THE UPPER 30S OUTSIDE OF THE LAKE SNOW AREAS. LOWS
DURING FRIDAY NIGHT WILL BE IN THE LOW TO MID 20S OVERALL...WITH
SOME UPPER 20S IN THE LAKE SNOW AREAS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RIDGING CONTINUES ACROSS THE AREA SUNDAY AND MONDAY WHICH SHOULD
BRING AN END TO THE LAKE EFFECT ACTIVITY. THE RIDGE SHIFTS EAST OF
THE AREA BY TUESDAY SETTING UP A PERIOD OF WEAK WARM AIR ADVECTION
AHEAD OF A LOW MOVING THROUGH THE LAKES REGION INTO CANADA. THERE
COULD BE A GENERAL LIGHT SNOW TUESDAY AND TUESDAY NIGHT.
LATEST MEDIUM RANGE MODELS AND ENSEMBLE FORECASTS ARE CONTINUING
TO SHOW AN INTERESTING FEATURE DEVELOPING BY MID WEEK IN THE FORM
OF LOW PRESSURE OVER THE GULF COASTAL STATE AND WORKING NORTHWARD
IN THE WEDNESDAY TO THURSDAY TIME FRAME. MODELS STILL UNDECIDED ON
TRACK OF THE LOW. SOME SUGGESTION THAT THE TRACK MAY REMAIN SOUTH
OF THE AREA WHICH WOULD ALLOW FOR THE BULK OF THE PRECIPITATION TO
BE A WINTRY VARIETY. THE 12Z GFS AND ECMWF SUGGESTING A MORE
WESTERN TRACK WHICH WOULD ALLOW FOR A WARMER SOLUTION. THIS PERIOD
WILL HAVE TO BE MONITOR CLOSELY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
LAKE EFFECT PROCESSES WILL AFFECT A LARGE PORTION OF WESTERN AND
NORTH CENTRAL NEW YORK IN SOME FORM OR ANOTHER THROUGH FRIDAY
EVENING AS PLUMES OF SNOW WILL EXTEND INLAND OFF BOTH LAKES ERIE AND
ONTARIO. THIS WILL DIRECTLY IMPACT OPERATIONS AT KBUF WHERE
SIGNIFICANT DELAYS WILL BE POSSIBLE. LESSER OPERATIONAL PROBLEMS
WILL BE POSSIBLE AT ALL OF THE OTHER SITES.
FOR WESTERN NEW YORK...LAKE EFFECT PRECIPITATION HAS ALREADY
DEVELOPED OVER LAKE ERIE AND HAS SPREAD INLAND ACROSS PARTS OF THE
WRN SOUTHERN TIER. WHILE IFR CIGS AND IFR/MVFR VSBYS WILL BE
PRODUCED AT KJHW AS A RESULT OF THIS ACTIVITY...THIS SHOULD ONLY BE
A PROBLEM DURING THE REMAINING PRE DAWN HOURS. THE LAKE EFFECT WILL
PUSH NORTH AND OUT OF THIS TAF SITE BY DAYBREAK...WITH CONDITIONS
IMPROVING TO VFR BY MID MORNING.
WHILE KJHW WILL EXPERIENCE SIGNIFICANT IMPROVEMENTS...THE EXACT
OPPOSITE WILL TAKE PLACE AT KBUF. CIGS AND VSBYS WILL LOWER TO LIFR
BY DAYBREAK IN MODERATE TO HEAVY SNOW. THERE WILL EVEN BE THE CHANCE
FOR SOME THUNDER AND LIGHTNING THIS MORNING IN GRAUPEL. SIGNIFICANT
DELAYS DUE TO THE LIFR CIGS/VSBYS AND DETERIORATING RUNWAY
CONDITIONS WILL BE LIKELY. THIS BAND IS NOT EXPECTED TO LIFT ALL THE
WAY TO KIAG...BUT LESSER IMPACTS ARE STILL POSSIBLE FOR THAT SITE
WITH MVFR CONDITIONS SETTING UP. AGAIN...THE BAND WILL PRIMARILY
AFFECT KBUF. THE LAKE EFFECT SHOULD THEN WEAKEN THIS (FRI) EVENING
WITH CONDITIONS IMPROVING TO AT LEAST MVFR.
AT ROC...EXPECT VFR CONDITIONS THROUGH DAYBREAK AS A BKN CLOUD
STRATO-CU DECK MOVES IN. WILL LIKELY SEE CONDITIONS DROP TO MVFR FOR
A FEW HOURS IN LAKE EFFECT SNOW BANDS DURING THE DAY FRIDAY...WITH
FAIR CONFIDENCE IN TIMING IN TAF...THOUGH CONDITIONS MAY BRIEFLY
DROP BELOW TAF FORECAST.
EAST OF LAKE ONTARIO...AT KART...VFR CIGS WILL BE IN PLACE THROUGH
THE REST OF THE OVERNIGHT. DURING THE DAY FRIDAY THOUGH...LAKE
EFFECT SNOW WILL DEVELOP JUST TO THE SOUTH OF KART AND LIFT NORTH.
THIS WILL LIKELY RESULT IN CONDITIONS DETERIORATING TO AT LEAST MVFR
WITH IFR VSBYS POSSIBLE. CONDITIONS WILL THEN RETURN TO VFR DURING
THE COURSE OF THIS (FRI) EVENING.
OUTLOOK...
SATURDAY...MVFR IN SCATTERED SNOW SHOWERS. LOCAL IFR/LIFR IN
STEADIER SNOWS EAST OF THE LAKES.
SUNDAY...VFR WITH OCCASIONAL MVFR IN SNOW SHOWERS.
MONDAY...MAINLY VFR.
TUESDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
SMALL CRAFT CONDITIONS ON ALL THE WATERS FOR NOW...THOUGH
ANTICIPATE DROPPING THE SCA IN BUFFALO HARBOR AND THE ST
LAWRENCE...AS WINDS DIMINISH. WAVES LINGER AT SCA CRITERIA INTO
THE EARLY MORNING HOURS...AND WITH WINDS AGAIN EXPECTED TO PICK
UP...WILL HOLD ONTO THE SCA FOR THE REMAINDER OF THE NEAR SHORE
WATERS. FLOW SHIFTS MORE SW ON FRIDAY...WITH WAVES LINGERING
PERHAPS A BIT LONGER ON THE EASTERN SHORES OF ONTARIO FRIDAY NIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 6 AM THIS MORNING TO 6 PM EST
THIS EVENING FOR NYZ001-002-011.
LAKE EFFECT SNOW WARNING FROM 6 AM THIS MORNING TO 10 PM EST
THIS EVENING FOR NYZ010.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LOZ042>045.
&&
$$
SYNOPSIS...TMA
NEAR TERM...APFFEL/TJP
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...RSH
MARINE...APFFEL/TMA
