Area Forecast Discussion
Issued by NWS Buffalo, NY

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FXUS61 KBUF 252210
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
510 PM EST TUE NOV 25 2014

.SYNOPSIS...
TEMPERATURES WILL CONTINUE TO FALL THROUGH THE AFTERNOON AND EVENING
HOURS...LESSENING THE SNOW MELT...AND REDUCING THE FLOODING THREAT
OVERNIGHT ACROSS PORTIONS OF THE REGION. THE COOLER TEMPERATURES
WILL BRING THE CHANCE OF SOME LIGHT LAKE ENHANCED DRIZZLE OR
FLURRIES EAST OF THE LAKES THROUGH THE OVERNIGHT HOURS. A NOR`EASTER WILL
LIFT ALONG THE COAST WEDNESDAY WITH JUST LIGHT ACCUMULATIONS ACROSS
CENTRAL NEW YORK. BELOW NORMAL TEMPERATURES AND A CHANCE OF SNOW
WILL RETURN FOR LATE THIS WEEK.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THIS AFTERNOON WATER VAPOR IMAGERY DISPLAYS A SHORTWAVE TROUGH
LIFTING NORTHEASTWARD FROM THE CENTRAL GREAT LAKES TOWARDS CENTRAL
QUEBEC. AT THE SURFACE A SURFACE TROUGH IS ALSO REFLECTED ACROSS THE
CENTRAL GREAT LAKES...WITH AN AREA OF HIGH PRESSURE OVER THE MID
MISSISSIPPI VALLEY.

SOUTHWEST WINDS AHEAD OF THIS TROUGH ARE FUNNELING UP LAKE ERIE THIS
AFTERNOON WITH GUSTS NEARING 40 MPH. THESE GUSTY WINDS WILL CONTINUE
THROUGH THE LATE AFTERNOON AND EARLY EVENING BEFORE THE PRESSURE
GRADIENT RELAXES...AS THE SURFACE TROUGH LIFTS NORTHEASTWARD AND THE
AREA OF HIGH PRESSURE EXPANDS NORTHEASTWARD.

THESE SOUTHWEST WINDS WILL VEER AROUND TO WESTERLY THROUGH THE
EVENING AND OVERNIGHT HOURS. OFF BOTH GREAT LAKES A WEAK LAKE EFFECT
RESPONSE WILL BE SEEN AS TEMPERATURES ALOFT AT 850 HPA DROP FROM -6C
TO -9C BY TOMORROW MORNING. MOISTURE IS PLENTIFUL BELOW 850
HPA...WHICH IS ALSO WHERE THE CAPPING LAKE INDUCED EQUILIBRIUM LEVEL
ALSO RESIDES. HOWEVER THE ZONE OF GOOD SNOW GROWTH IS FOUND HIGHER
AND WITHOUT ANY GREAT CONVERGENCE IN THE LOWER LEVELS TO LIFT THIS
MOISTURE UPWARD INTO THE GOOD SNOW GROWTH ZONE (-12 TO -18C LAYER)
THE RESULT WILL BE LIGHT DRIZZLE (WHICH WE SEE THIS AFTERNOON EAST
OF BOTH LAKES) THAT WILL TRANSITION TO LIGHT SNOW/FLURRIES/AND
PERHAPS EVEN FREEZING DRIZZLE EAST OF LAKE ERIE. POINT SOUNDINGS
SHOW THAT EAST OF LAKE ERIE WE REMAIN SATURATED UPWARD THROUGH ABOUT
-6 TO -8C...WHILE EAST OF LAKE ONTARIO WE REMAIN SATURATED UPWARD
THROUGH ABOUT -8 TO -10C. SINCE THE COLD...AND MOIST AIR IS A LITTLE
DEEPER EAST OF LAKE ONTARIO...EXPECT JUST DRIZZLE TRANSITIONING TO
SNOW...WHILE EAST OF LAKE ERIE THERE MAY BE SOME FREEZING DRIZZLE
THROUGH THE EVENING AND OVERNIGHT HOURS. THE BAND OF WEAK LAKE
EFFECT PRECIPITATION SHOULD BE PUSHING SOUTHWARD SUCH THAT BY TIME
WE REACH FREEZING THIS EVENING JUST SOUTHERN ERIE/WYOMING AND THE
WESTERN SOUTHERN TIER WILL HAVE THE POTENTIAL FOR SOME SLICK
SURFACES RESULTING FROM THE MIXTURE OF SNOW AND FREEZING DRIZZLE.
FOR SUCH WILL RUN A WINTER WEATHER ADVISORY FROM 5PM THROUGH 6 AM
TOMORROW.

TOMORROW WIND SHEAR WILL INCREASE AND DISRUPT ANY LAKE EFFECT BANDS
OF LIGHT PRECIPITATION. A NORTHEAST WIND EARLY WEDNESDAY MAY LINGER
A FEW LIGHT FLURRIES AND SNOW SHOWERS TO THE SE AND THEN SOUTHERN
SHORELINE OF LAKE ONTARIO TOMORROW. THIS ACTIVITY WILL BE AHEAD OF A
NOR`EASTER...A STORM WHOSE IMPACT WILL BE GREATEST TO OUR EAST.
WEDNESDAY A DEEPENING AREA OF LOW PRESSURE WILL BE ADVANCING FROM
THE CAROLINA COASTLINE NORTHEASTWARD TO OFF THE JERSEY SHORE BY
WEDNESDAY EVENING. THE WARM CONVEYOR BELT AHEAD OF THIS LOW WILL
LIFT ATLANTIC MOISTURE UPWARD AND BRING SNOW WESTWARD ENOUGH SUCH
THAT THE SOUTHERN GENESEE VALLEY AND TOWARDS THE FINGER LAKES REGION
AN INCH OR SO OF SNOW WILL ACCUMULATE. FOR THE
JAMESTOWN...BUFFALO...ROCHESTER...WATERTOWN AREAS ONLY A DUSTING TO
COATING OF SNOW IS EXPECTED.

LOWS TONIGHT WILL RANGE FROM THE MID/UPPER 20S ACROSS THE INLAND
SOUTHERN TIER TO AROUND THE FREEZING MARK NEAR THE LAKE SHORELINES.
HIGHS TOMORROW WILL ONLY CLIMB A FEW DEGREES WITH HIGHS RANGING
THROUGH THE 30S.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
COASTAL LOW WILL ACCELERATE NORTHWARD INTO NORTHERN ENGLAND
WEDNESDAY NIGHT. THIS WILL ALLOW THE WESTERN SHIELD OF ACCUMULATING
SNOW THAT MAY BE ACROSS THE FAR EASTERN PORTION OF THE AREA TO PULL
EAST. COLDER AIR WILL GET PULLED DOWN ACROSS THE LOWER LAKES AS THE
COASTAL LOW DEPARTS THURSDAY INTO FRIDAY. THE PASSAGE OF A TROUGH
THURSDAY INTO THURSDAY RIGHT WILL EFFECTIVELY RAISE LAKE INDUCED
EQUILIBRIUM LEVELS TO ABOVE 10K FEET. THIS SHOULD HELP TO REDEVELOP
LAKE EFFECT SNOWS ALONG THE CHAUTAUQUA RIDGE...AS THE BOUNDARY LAYER
FLOW ALIGNS WEST NORTHWESTERLY. LACK OF DEEP MOISTURE SHOULD LIMIT
ACCUMULATIONS THROUGH FRIDAY MORNING TO A 1-3/2-4 INCH ACCUMULATION.
LOW LEVEL FLOW DOES NOT LOOK AS WELL A WELL ALIGNED EAST OF LAKE
ONTARIO...BUT WE COULD STILL SEE A 1-3 INCH ACCUMULATION ACROSS THE
TUG HILL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
DEVELOPING ZONAL FLOW PATTERN WILL ALLOW FOR A DECENT MODERATING
TREND DURING THE WEEKEND. SEE LITTLE IN THE WAY OF FORCING MECHANISM
FOR PRECIPITATION OVER THE WEEKEND...AS THE BAROCLINIC ZONE LIFTS
NORTH ALLOWING MILDER AIR TO OVERSPREAD THE AREA. ONLY SOURCE OF
LIFT OTHER THAN A BROAD WARM AIR ADVECTION PATTERN PROVIDING SOME
WEAK ISENTROPIC ASCENT ARE SOME SUBTLE WEAK PERTURBATIONS WORKING
THROUGH THE FLOW. THEREFORE...THINK THE BULK OF THE WEEKEND WILL BE
DRY WITH ONLY SOME LIMITED OPPORTUNITIES FOR MAINLY LIGHT RAIN
SHOWERS.

BY EARLY NEXT NEXT...IT LOOKS AS IF THE UPPER FLOW WILL BUCKLE OVER
THE GREAT LAKES REGION FORCING A COLD FRONT SOUTHWARD ACROSS THE
REGION. THIS WILL SEND COLDER AIR BACK DOWN ACROSS THE REGION AS 850
MB TEMPERATURES DROP TO -12C TO -14C BEHIND IT. SOME LAKE EFFECT
SNOW IS PROBABLE IN FAVORED NORTHWEST FLOW AREA IN THE MONDAY TIME
FRAME. HOWEVER...CYCLONIC FLOW WILL BE LACKING AS BROAD HIGH
PRESSURE RIDGE OVER 1040 MB EXPANDS EASTWARD FROM THE NORTHERN
PLAINS TO THE GREAT LAKES. THE ASSOCIATED DRIER AIR AND ANTICYCLONIC
FLOW SHOULD LIMIT THE LAKE EFFECT SNOW COVERAGE AND INTENSITY.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
AT 18Z MVFR AND VFR FLIGHT CONDITIONS ARE FOUND ACROSS THE REGION. A
SOUTHWEST WIND WITHIN COLD AIR ADVECTION HAS DEVELOPED A BAND OF
WEAK LAKE EFFECT ACTIVITY...WITH THE BULK OF THE ACTIVITY THIS EARLY
AFTERNOON IN THE FORM OF DRIZZLE/LIGHT SHOWER. AS THE COLD AIR
DEEPENS AND WINDS VEER TO WEST/NORTHWESTERLY ACTIVITY WILL CHANGE
OVER TO SNOW...AND POSSIBLY FREEZING DRIZZLE. OFF LAKE ERIE THIS
CHANGE SHOULD HAPPEN AFTER THE BAND CROSSES THE KIAG/KBUF
AIRFIELDS...BUT OFF LAKE ONTARIO IT MAY CLIP THE AIRFIELD WITH A
WINTRY MIX BEFORE DROPPING SOUTHWARD OVERNIGHT.

THIS LAKE EFFECT ACTIVITY WILL DIMINISH LATER OVERNIGHT AS WIND
SHEER INCREASES WITH THE NEARING OF A COASTAL STORM ALONG THE MID
ATLANTIC COASTLINE. A SHORT-LIVED NORTHERLY FLOW OFF LAKE ONTARIO
LATER OVERNIGHT MAY BRING SOME MVFR CIGS ACROSS THE KROC AIRFIELD
LATE OVERNIGHT AND EARLY TOMORROW MORNING.

THIS SYNOPTIC STORM SYSTEM WILL LARGELY REMAIN EAST OF OUR
AREA...WITH POSSIBLY A FEW FLAKES FOUND ACROSS THE KROC/KART
AIRFIELDS TOMORROW AFTERNOON.

OUTLOOK...
WEDNESDAY NIGHT THROUGH FRIDAY...MAINLY VFR WITH A CHANCE OF MVFR
SNOW SHOWERS.
SATURDAY AND SUNDAY...MAINLY VFR WITH A CHANCE FOR RAIN AND SNOW
SHOWERS.

&&

.MARINE...
LATE THIS AFTERNOON...DUNKIRK AND BUFFALO NOS WERE REPORTING WINDS NEAR 30
KTS...SO HAVE UPDATE THE NEARSHORES TO REFLECT THIS AND TO EXTEND
THE SMALL CRAFT ADVISORY BY A FEW HOURS. THIS SAID...MESOSCALE
MODEL GUIDANCE DRASTICALLY DIMINISHES WINDS ALOFT THROUGH THIS
EVENING...WITH WINDS LIKELY TO DROP OFF MARKEDLY BETWEEN 5 PM AND
8 PM ON LAKE ERIE.

A RELAXING PRESSURE GRADIENT THIS EVENING WILL ALLOW FOR WINDS TO
WEAKEN THROUGH THE OVERNIGHT AND WAVE HEIGHTS TO SUBSEQUENTLY
DIMINISH. WILL CONTINUE WITH SMALL CRAFT ADVISORIES AS OUTLINED
BELOW ON THE LAKES...AND ALSO THE NIAGARA RIVER THIS EVENING BEFORE
CONDITIONS IMPROVE SUCH THAT SCA WILL NO LONGER BE NEEDED.

A WEAK AREA OF HIGH PRESSURE IS THEN EXPECTED TO SHIFT OVER THE
LOWER LAKES WITH LIGHTER WINDS EXPECTED FOR WEDNESDAY AS A
DEVELOPING NOR`EASTER SHIFTS NORTH ALONG THE COAST. WESTERLIES WILL
FRESHEN ON THE LAKES TOWARDS THE END OF THE WEEK IN THE WAKE OF THIS
STRONG COASTAL STORM PASSING WELL TO OUR EAST ALONG THE EASTERN
SEABOARD.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 6 AM EST WEDNESDAY FOR NYZ012-
     019>021-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR LEZ020.
         SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR LEZ040-
         041.
         SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR
         LOZ030.
         SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
         LOZ043>045.
         SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR LOZ042.

&&

$$

SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...THOMAS
MARINE...APFFEL/THOMAS






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