-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 121142
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
642 AM EST THU DEC 12 2013

.SYNOPSIS...
A COLD FRONT HAS PUSHED SOUTH OF THE AREA AND WILL BE FOLLOWED
BY MUCH COLDER TEMPERATURES. HIGHS EACH DAY THROUGH SATURDAY WILL
BE GENERALLY IN THE TEENS. A REINFORCING COLD FRONT AND ASSOCIATED
UPPER LEVEL DISTURBANCE WILL BRING SNOW SHOWERS TO THE AREA LATER
TODAY INTO FRIDAY MORNING. SEVERAL INCHES OF SNOW ARE EXPECTED IN
THE NORTHERN ADIRONDACKS AND OVER THE NORTHERN GREEN MOUNTAINS.
A QUICK MOVING LOW PRESSURE SYSTEM PASSING SOUTH OF NEW ENGLAND
WILL BRING ADDITIONAL LIGHT SNOW SATURDAY NIGHT INTO SUNDAY.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 454 AM EST THURSDAY...WEAK SURFACE RIDGE BUILDING ACROSS
THE NORTH COUNTRY THIS MORNING. WHILE SKIES HAVE CLEARED ACROSS
NORTHERN NEW YORK...CLOUDS AND EVEN SOME LIGHT SNOW SHOWERS OR
FLURRIES CONTINUE ACROSS PORTIONS OF VERMONT. EXPECT ANY LIGHT
PRECIP TO END EARLY TODAY WITH SKIES CLEARING BY MID MORNING. AS
RIDGE AXIS SLIDES TO OUR EAST THIS AFTERNOON...WINDS WILL SHIFT
INTO THE SOUTH AND SOUTHWEST...AND WE WILL SEE CLOUDS QUICKLY
RETURN TO NORTHERN NEW YORK ALONG WITH INCREASING CHANCES FOR SNOW
SHOWERS. LAKE EFFECT SNOWBAND OFF ONTARIO WILL LIFT NORTH INTO
SOUTHEASTERN PORTION OF SAINT LAWRENCE COUNTY...WHERE A LAKE EFFECT
SNOW ADVISORY HAS BEEN ISSUED FOR THIS AFTERNOON THROUGH TONIGHT.
ANY ACCUMULATION BY LATER THIS AFTERNOON SHOULD BE LIMITED TO AN
INCH OR TWO...WITH MORE TO COME TONIGHT. 850 MB TEMPS THIS AFTERNOON
WILL BE AROUND -20C...ALLOWING FOR MAX TEMPS ONLY IN THE TEENS.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH SATURDAY/...
AS OF 454 AM EST THURSDAY...CHANCES FOR SNOW SHOWERS INCREASE
TONIGHT INTO FRIDAY MORNING AS YET ANOTHER COLD FRONT DROPS SOUTH
ACROSS THE AREA. WEST-SOUTHWEST FLOW IN ADVANCE OF THE FRONT
SHOULD ALLOW FOR SUFFICIENT MOISTURE FROM THE GREAT LAKES FOR
SCATTERED TO NUMEROUS SNOW SHOWERS...WHICH WILL BE MOST PREVALENT
OVER THE ADIRONDACKS AND HIGHER TERRAIN OF NORTHERN VERMONT. IN
ADDITION...WITH SURFACE TO 850 MB WINDS FROM THE WEST-SOUTHWEST
TONIGHT IN ADVANCE OF THE FRONT...CONDITIONS FAVORABLE FOR LAKE
ONTARIO SNOWBANDS TO IMPACT SOUTHERN ST. LAWRENCE COUNTY...EXTENDING
AT TIMES INTO SOUTHERN FRANKLIN AND ESSEX COUNTIES AS WELL. HIGHEST
TOTAL ACCUMULATION EXPECTED IN SOUTHEAST ST LAWRENCE COUNTY WHERE
6 INCH ACCUMULATIONS POSSIBLE. A BIT LESS JUST OUTSIDE OF THE
ADVISORY AREA. ELSEWHERE...SOME SNOW ACCUMULATIONS MAY ALSO BE
EXPECTED ACROSS NORTHERN VERMONT...ESPECIALLY THE HIGHER TERRAIN
WHERE ANYWHERE FROM 1 TO 4 INCHES MAY ACCUMULATE...WITH SOME
LOCALLY HEAVY SNOW SHOWERS OR PERHAPS A SQUALL POSSIBLE IN
ADVANCE OF THE FRONT.

SNOW SHOWER ACTIVITY WILL TAPER OFF FROM NORTH TO SOUTH DURING THE
DAY ON FRIDAY AS FRONT DEPRESSES SOUTH OF THE AREA. ALSO EXPECT SOME
CLEARING DURING THE AFTERNOON AS DRIER AIR ASSOCIATED WITH HIGH
PRESSURE TO THE NORTH BUILDS SOUTH INTO THE REGION. 850 MB TEMPS
ON FRIDAY FALL FROM AROUND -18C IN THE MORNING TO -22C BY DAYS
END...MAKING FOR A TRICKY TEMP FORECAST. TEMPS WILL BE IN THE
TEENS FOR MUCH OF TONIGHT...WITH SOME SINGLE DIGITS OVER THE
HIGHER TERRAIN OF NORTHERN ZONES. WITH LOW LEVEL COLD AIR
ADVECTION DURING FRIDAY...EXPECT MORNING HIGHS TO RANGE FROM LOW
TEENS NORTH TO LOWER 20S SOUTH...WITH FALLING TEMPS THEREAFTER ON
NORTHERLY BREEZES.

SURFACE RIDGE BUILDS INTO THE NORTH COUNTRY FRIDAY NIGHT...RESULTING
IN MAINLY CLEAR SKIES AND VERY COLD TEMPERATURES...WITH MANY
LOCATIONS DROPPING BELOW ZERO. NORMALLY COLDER PORTIONS OF THE
ADIRONDACKS AND NORTHEAST KINGDOM MAY SEE LOWS OF 15 TO 20 BELOW.
IT WILL REMAIN UNSEASONABLY COLD ON SATURDAY AS THE HIGH MAKES ITS
WAY EAST INTO MAINE AND THE MARITIMES. EXPECT HIGHS MAINLY FROM 10
TO 15 DEGREES. WE WILL ALSO SEE INCREASING CLOUDS WITH SOME LIGHT
SNOW DEVELOPING FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION DURING
THE AFTERNOON. THIS DUE TO A PAIR OF DEVELOPING LOW PRESSURE
SYSTEMS...ONE OVER THE OHIO VALLEY AND THE OTHER NEAR THE MID
ATLANTIC COAST.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 343 AM EST THURSDAY...OVERALL FORECAST REMAINS ON TRACK FOR
THE EXTENDED PERIOD WITH THE MAIN FEATURE BEING A COASTAL SYSTEM
WHICH WILL IMPACT THE NORTHEAST SATURDAY NIGHT THROUGH SUNDAY.
CONFIDENCE REMAINS HIGH THAT WE`LL SEE ACCUMULATING SNOW FROM
THIS SYSTEM...THOUGH THE EXACT TOTALS ARE CURRENTLY UNCERTAIN.

00Z RUNS OF THE GFS AND ECMWF REMAIN VERY CONSISTENT WITH PREVIOUS
RUNS SHOWING SURFACE LOW PRESSURE DEVELOPING OFF THE DELMARVA
PENINSULA SATURDAY NIGHT...SHIFTING NORTHEAST OVER THE BENCHMARK AND
INTO THE GULF OF MAINE SUNDAY MORNING. AT 500MB AND 700MB FLOW IS
AN OPEN TROUGH WITH NO CLOSED CIRCULATION AND IS OFF TO OUR
NORTHWEST RESULTING IN BROAD SOUTHWESTERLY FLOW ALOFT ACROSS THE
REGION. THIS COMBINED WITH STRONG HIGH PRESSURE IN PLACE AHEAD OF
THE SYSTEM HAS RESULTED IN A TREND TOWARDS LESS OVERALL QPF ACROSS
OUR CWA...WITH TOTAL AMOUNTS THROUGH SUNDAY GENERALLY RANGING FROM
1-2 TENTHS ACROSS THE SAINT LAWRENCE VALLEY AND SOUTHEAST DOWNSLOPE
PRONE AREAS OF VERMONT TO NEAR A THIRD OF AN INCH ACROSS SOUTHERN
VERMONT. GIVEN THE COLD AIRMASS IN PLACE...SNOW TO LIQUID RATIOS
ARE LIKELY TO RANGE FROM 15-20:1 YIELDING SNOW AMOUNTS OF 2-6"
WHICH MAY REQUIRE A FUTURE ADVISORY.

HIGH PRESSURE FOLLOWS FOR MONDAY WITH DRY CONDITIONS BUT IS
SHORT-LIVED AS A WEAK CLIPPER SYSTEM WILL RENEW CHANCES FOR SNOW
SHOWERS MONDAY NIGHT THROUGH TUESDAY NIGHT. OVERALL QPF WILL BE LIGHT
WITH THIS SYSTEM AS IS USUALLY THE CASE WITH CLIPPERS...BUT WE COULD
PICK UP A FEW INCHES OF ACCUMULATION ESPECIALLY ACROSS THE HIGHER
TERRAIN. UNSETTLED CONDITIONS CONTINUE THROUGH WEDNESDAY NIGHT AS
WELL WITH CONTINUED CHANCES FOR ISOLATED/SCATTERED SNOW SHOWERS AS
A BROAD UPPER TROUGH SETTLES OVER THE REGION.

TEMPS THROUGH THE PERIOD REMAIN BELOW NORMAL THROUGH TUESDAY WITH
HIGHS GENERALLY IN THE 20S THOUGH TEENS ON MONDAY...AND LOWS IN THE
SINGLE DIGITS TO LOWER TEENS. TEMPS LOOK TO MODERATE CLOSER TO
NORMAL FROM TUESDAY NIGHT ONWARD WITH HIGHS WEDNESDAY PUSHING INTO
THE MID 20S TO LOWER 30S.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
THROUGH 12Z FRIDAY...ALL SITES WILL REMAIN VFR THROUGH 21Z BEFORE
A TREND TOWARDS IFR/MVFR. CONDITIONS RETURN BACK TO MVFR/IFR AT
KSLK AFTER 21Z AS A LAKE EFFECT BAND REDEVELOPS AND SHIFTS
NORTHWARD INTO THE DACKS. MEANWHILE...ALL OTHER SITES REMAIN VFR
THROUGH 06Z BEFORE ANOTHER ARCTIC COLD FRONT SAGS SOUTHWARD ACROSS
THE AREA WITH A ROUND OF IFR/MVFR SNOW SQUALLS LIKELY THROUGH 12Z.
SQUALLS WILL BE ACCOMPANIED BY A WIND SHIFT TO THE WEST AND GUSTS
UP TO 25KTS.

OUTLOOK 12Z FRIDAY THROUGH MONDAY...

12Z FRIDAY THROUGH 18Z FRIDAY...MVFR/IFR CONDITIONS LIKELY IN SNOW
EARLY...IMPROVING BY 18Z.

18Z FRIDAY THROUGH 18Z SATURDAY...GENERALLY VFR UNDER HIGH PRESSURE.

18Z SATURDAY THROUGH SUNDAY...IFR/MVFR CONDITIONS DEVELOPING IN
LIGHT SNOW.
-- End Changed Discussion --

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 7 AM EST
     FRIDAY FOR NYZ029.

&&

$$
SYNOPSIS...RJS
NEAR TERM...RJS
SHORT TERM...RJS
LONG TERM...LAHIFF
AVIATION...LAHIFF