FXUS61 KBTV 081134
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
634 AM EST TUE DEC 8 2009
.SYNOPSIS...
LIGHT SNOW SHOWERS WILL BE POSSIBLE THIS MORNING...MAINLY IN THE
MOUNTAINS. ANY ACCUMULATIONS WILL BE LIGHT. AFTER A BRIEF
RESPITE...THE CHANCES FOR PRECIPITATION RETURN LATE TONIGHT AS A
STRONG STORM SYSTEM MOVES ACROSS THE MIDWEST STATES. SNOW WILL
SPREAD ACROSS THE NORTH COUNTRY FROM THE SOUTHWEST AFTER MIDNIGHT
TONIGHT...THEN BECOME HEAVY WEDNESDAY MORNING. SEVERAL INCHES OF
ACCUMULATION ARE POSSIBLE...ESPECIALLY IN EASTERN VERMONT AND THE
EASTERN PORTIONS OF THE ADIRONDACKS. SNOW WILL BECOME A MIX OF SLEET
AND RAIN WEDNESDAY AFTERNOON BEFORE CHANGING BACK TO ALL SNOW
WEDNESDAY NIGHT. STRONG GUSTY WINDS ARE EXPECTED WEDNESDAY THROUGH
THURSDAY...WITH SOME POWER OUTAGES POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 444 AM EST TUESDAY...RELATIVELY QUIET CONDITIONS EXPECTED
ARE EXPECTED TODAY. A WEAK VORT MAX WILL TRAVERSE ACROSS THE
FORECAST AREA THIS MORNING ALLOWING LIGHT SNOW SHOWERS TO
DEVELOP...ESPECIALLY OVER MOUNTAINS. MOISTURE WILL BE SOMEWHAT
LIMITED SO DON/T EXPECT MUCH IN THE WAY OF ACCUMULATION. SHOWER
ACTIVITY WILL DISSIPATE THIS AFTERNOON AS THE VORT PULLS INTO
MAINE AND SURFACE HIGH PRESSURE TAKES HOLD OVER THE NORTH
COUNTRY. TEMPERATURES WILL BE NEAR NORMAL WITH HIGHS EXPECTED TO
TOP OUT IN THE LOWER TO MID 30S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 444 AM EST TUESDAY...A VERY COMPLICATED FORECAST FOR THE
SHORT TERM WITH PRECIPITATION TYPE...TOTAL SNOWFALL
ACCUMULATIONS...AND GUSTY WINDS ALL MAJOR CONCERNS. THE GFS HAS
BEEN THE MOST CONSISTENT WITH THIS FEATURE AND SO WAS THE
PREFERRED SOLUTION WITH A FEW TWEAKS TO THE DETAILS. SEVERAL
HEADLINES HAVE BEEN ISSUED...AND ARE DETAILED BELOW.
FOR TONIGHT...START OUT DRY AS AFOREMENTIONED SURFACE RIDGE CRESTS
OVER THE FORECAST AREA. IT QUICKLY SHUNTS EASTWARD AS A VIGOROUS LOW
PRESSURE SYSTEM MOVES NORTHEAST ACROSS THE MIDWESTERN CONUS.
CURRENT SURFACE ANALYSIS AND OBSERVATIONS PLACE THIS FEATURE IN THE
VICINITY OF THE FOUR CORNERS WITH WIDESPREAD SNOW BEING REPORTED
FROM ILLINOIS TO COLORADO. AS THIS FEATURE MOVES TO NEAR CHICAGO BY
12Z WED SNOW WILL SPREAD OVER THE FORECAST AREA FROM SOUTHWEST TO
NORTHEAST. PRECIPITATION RATES WILL INITIALLY BE LIGHT WITH JUST A
DUSTING TO A HALF INCH EXPECTED SOUTH OF A MASSENA TO BURLINGTON TO
LEBANON LINE. SOUTH FLOW WILL INCREASE DURING THE OVERNIGHT AS
WELL...USHERING WARM AIR INTO THE REGION. STAYED CLOSE TO GFS
NUMBERS FOR OVERNIGHT TEMPERATURES AS OTHER MODELS LOOKED TOO COLD.
WEDNESDAY...WAA REALLY PICKS UP DURING THE MORNING AS THE SURFACE
LOW MOVES ACROSS THE GREAT LAKES TO NEAR GEORGIA BAY AND A SOUTHERLY
JET OF 65+ KT STREAMS INTO NEW YORK AND NEW ENGLAND. THE MID AND
UPPER LEVEL JETS WILL BE ACROSS SOUTHERN NEW ENGLAND PLACING THE
FORECAST AREA IN THE FAVORABLE LEFT FRONT QUADRANT. AS SUCH EXPECT A
BURST OF HEAVY SNOW TO AFFECT THE REGION IN THE 12Z-15Z TIME FRAME.
SEVERAL INCHES OF SNOW ARE POSSIBLE DURING THIS PERIOD.THIS IS
ESPECIALLY TRUE IN SOUTHEAST VERMONT AND THE EASTERN SLOPES OF THE
ADIRONDACKS AS STRONG SOUTHEAST WINDS RESULT IN CONSIDERABLE UPSLOPE
PRECIPITATION. THIS WIND ORIENTATION IS ALSO IDEAL FOR
DOWNSLOPING ON THE WESTERN SIDE OF THE GREENS WITH GUSTS OF 50 TO 60
MPH POSSIBLE ESPECIALLY IN THE USUAL PRONE MOUNTAIN GAPS. WINDS WILL
GRADUALLY INCREASE DURING THE MORNING HOURS AND PEAK IN THE EARLY TO
MID AFTERNOON. POWER OUTAGES WILL BE POSSIBLE AS TREES AND POWER
LINES COULD COME DOWN. HAVE THEREFORE ISSUED A HIGH WIND WATCH 12Z
WED THROUGH 00Z THU FOR THESE AREAS. AS BEST LIFT SHIFTS EAST DURING
THE LATE MORNING/EARLY AFTERNOON...PRECIPITATION RATES WILL WIND
DOWN. WITH WARM AIR CONTINUING TO STREAM IN ALOFT SNOW WILL BEGIN TO
CHANGE TO SLEET AND EVENTUALLY RAIN FROM SOUTH TO NORTH. THE EXACT
NORTHWARD EXTENT OF THE WARM LAYER AND RESULTANT MIXED PRECIPITATION
IS STILL DIFFICULT TO PINPOINT. 00Z GFS BRINGS THE 850MB 0C LINE TO
THE CANADIAN BORDER WITH 925MB TEMPS REACHING 1-3C, WHILE THE 00Z
NAM KEEPS THE FREEZING LINE AT BOTH LEVELS CONFINED TO SOUTHERN NEW
ENGLAND. THIS DISPARITY IS MAINLY DUE TO HOW THE MODELS HANDLE
SECONDARY CYCLOGENESIS. THE GFS KEEPS AN OPEN TROUGH THAT EXTENDS
INTO THE GULF OF MAINE AND DOES NOT FORM A CLOSED LOW UNTIL 12Z THU
OVER EXTREME NORTHEAST MAINE. THE 00Z NAM MEANWHILE IS MORE
AGGRESSIVE WITH COASTAL DEVELOPMENT WITH A 985MB LOW JUST OFF THE
NH/ME COAST BY 03Z THU. AS MENTIONED PREVIOUSLY...THE WARMER GFS
SOLUTION IS PREFERRED AS IT HAS BEEN MOST CONSISTENT AND THE COLDER
NAM IS AN OUTLIER. HOWEVER...DID THINK THAT THE GFS WAS TOO GENEROUS
WITH LIQUID PRECIPITATION AS IT HAD RAIN SPREAD TO NEARLY THE
INTERNATIONAL BORDER. THEREFORE TRENDED A BIT COLDER AND KEPT MORE
OF A MIX IN THE FORECAST ESPECIALLY IN THE ELEVATED VALLEYS OF
NORTHEAST VERMONT WHERE COLD AIR WILL BE MORE DIFFICULT TO SCOUR
OUT. THIS SHOULD RESULT IN A FEW MORE INCHES OF ACCUMULATING SLEET
AND SNOW IN THESE AREAS WEDNESDAY AFTERNOON AND EVENING. BY THE TIME
ALL IS SAID AND DONE...SNOWFALL AMOUNTS OF 3-5 INCHES ARE EXPECTED
IN THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS...WITH 4-8 INCHES IN THE
ADIRONDACKS AND EASTERN GREENS. ACCORDINGLY...ISSUED A WINTER
WEATHER ADVISORY FOR THE VALLEYS AND A WINTER STORM WATCH FOR THE
MOUNTAINS.
WEDNESDAY NIGHT...SURFACE LOW CONTINUES ITS JOURNEY ACROSS ONTARIO
AND EVENTUALLY INTO WESTERN QUEBEC WHILE A SECONDARY LOW STARTS TO
DEVELOP OVER NORTHERN MAINE. BUFKIT PROFILES INDICATE THAT MIXED
PRECIPITATION WILL WIND DOWN AS FLOW BECOMES MORE WESTERLY AND COLD
AIR FILTERS IN ALOFT. HENCE EXPECT MAINLY JUST RAIN AND SNOW
WEDNESDAY EVENING CHANGING TO ALL SNOW AS THE BOUNDARY LAYER COOLS.
PRECIPITATION WILL BECOME MORE OROGRAPHIC IN NATURE OVERNIGHT AS
MAIN DYNAMICS SHIFT EAST AND UPSLOPE SHIFTS TO THE WESTERN SIDES OF
THE MOUNTAINS. DOWNSLOPING INTO THE CHAMPLAIN VALLEY WILL PREVENT
MUCH MORE ADDITIONAL ACCUMULATION THERE. WINDS...WHILE CHANGING
DIRECTION...WILL REMAIN GUSTY AND SCATTERED POWER OUTAGES WILL
CONTINUE TO BE POSSIBLE.
THURSDAY...LOW PRESSURE WILL CONTINUE TO PULL AWAY FROM VERMONT AND
NORTHERN NEW YORK THURSDAY. SNOW SHOWERS WILL ALSO CONTINUE AS THE
UPPER TROUGH SPINS OVER THE REGION. IN ADDITION...LAKE EFFECT SNOW
WILL DEVELOP OFF OF LAKE ONTARIO AND SPREAD INTO THE ADIRONDACKS AND
ALONG THE SOUTHERN GREENS IN STRONG WEST FLOW. SCATTERED WIND DAMAGE
WILL ALSO CONTINUE TO BE POSSIBLE WITH GUSTS OF 40+ MPH EXPECTED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 343 AM EST TUESDAY...A WINTRY PATTERN WILL BE IN PLACE THRU THE
PERIOD WITH TEMPERATURES GENERALLY BELOW NORMAL AND PROSPECTS FOR
SNOW SHOWERS...ESPECIALLY IN THE MTNS. MOSTLY CLOUDY TO CLOUDY
CONDITIONS EXPECTED. BEST SHOT FOR ANY SUNSHINE WOULD BE SATURDAY
OR EARLY SUNDAY BASED ON CURRENT INDICATIONS.
THURSDAY NIGHT: GRADIENT WINDS REMAIN MODERATELY STRONG FROM THE
WEST-NORTHWEST WITH LOW-LEVEL CAA CONTINUING. 00Z GFS ENSEMBLE
SHOWS 850MB TEMPS DROPPING TO -16 TO -17C BY 12Z FRIDAY. THERE
WON/T BE A HUGE RANGE IN OVERNIGHT TEMPERATURES WITH WINDS REMAINING
10-20 MPH MUCH OF THE NIGHT...AND CONSIDERABLE CLOUD COVER AND LIGHT
SNOW SHOWERS POSSIBLE. LOWS WILL GENERALLY BE IN THE TEENS. A LIGHT
SNOW ACCUMULATION IS POSSIBLE IN THE NRN MTNS ESPECIALLY IN FAVORED
UPSLOPE FLOW AREAS.
FRIDAY/FRIDAY NIGHT: LITTLE OVERALL CHANGE. A BRISK DAY EXPECTED
WITH COLD TEMPS /HIGHS LOW TO MID 20S/ AND CONTINUED WNWLY GRADIENT
WINDS /15-25 MPH AT TIMES/. MAINTAINED A CHANCE OF SNOW SHOWER
ACTIVITY ESPECIALLY FOR CENTRAL AND NRN AREAS...WITH LIGHT
ACCUMULATIONS
POSSIBLE IN W/NW FACING SLOPES. FRIDAY NIGHT SHOULD BE SLIGHTLY
COLDER THAN THURSDAY NIGHT WITH WINDS BECOMING LIGHT AFTER MIDNIGHT
AND 850MB TEMPS DOWN TO -18C TO -20C. LOWS WILL RANGE FROM 5-10F IN
THE NRN ADIRONDACKS AND NERN VT AND 10-15F ELSEWHERE.
SATURDAY: CHANCE FOR SOME SUNNY BREAKS AS SFC-700MB RIDGE AXIS
CRESTS OVER THE NORTH COUNTRY WITH MID-LEVEL SUBSIDENCE. THIS SHOULD
BRING AN END TO THE -SHSN ACTIVITY. HIGHS WILL GENERALLY BE IN THE
25-30F WITH SOME MODERATION IN AIR MASS EXPECTED.
SUNDAY: FAIR CONDITIONS EARLY...WITH MOST GUIDANCE HINTING AT
POSSIBLE FAST MOVING ARCTIC BNDRY SWEEPING SEWD ACROSS THE AREA
SUNDAY AFTN/EARLY EVENING. INCLUDED SOME SNOW SHOWERS FOR SUNDAY.
TOO EARLY TO SAY...BUT SUCH A FRONTAL PASSAGE WILL SOMETIMES YIELD A
PERIOD OF SOME HEAVIER SNOW SQUALLS WITH STG FRONTAL CONVERGENCE AND
A QUICK COUPLE OF INCHES OF SNOWFALL AND GUSTY WINDS. WE WILL
CONTINUE TO MONITOR THIS. HIGHS SUNDAY MAINLY IN THE 20S.
MONDAY: NORTHWEST FLOW AND COLD TEMPERATURES ANTICIPATED ATTM WITH
HIGHS GENERALLY IN THE LOWER TO MID 20S. SOME SNOW SHOWERS WILL BE
POSSIBLE ESPECIALLY IN OROGRAPHICALLY FAVORED W/NW FACING SLOPES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...PREVAILING MID-LEVEL WLY FLOW CONTINUES TO
BRING ABUNDANT MOISTURE FROM THE GREAT LAKES RESULTING IN
GENERALLY MVFR CEILINGS AND OCCASIONAL LIGHT SNOW SHOWER ACTIVITY
EARLY THIS MORNING. VSBY IS GENERALLY 3-5SM IN -SHSN. IT APPEARS
THESE CONDITIONS WILL CONTINUE AREAWIDE UNTIL AROUND 14-15Z. THERE IS
CLEARING NOTED NW OF KMSS...AND BREAKS IN THE OVERCAST SHOULD
DEVELOP AND CIGS SHOULD GENERALLY RISE INTO THE VFR CATEGORY BY
LATE MORNING/EARLY AFTN. HIGH PRESSURE BUILDS ACROSS THE NORTH
COUNTRY THIS AFTN FROM SERN ONTARIO. AS LOW CLOUDS DISSIPATE
TOWARD THIS EVENING...HIGH CLOUDS WILL BEGIN TO STREAM IN FROM SW-
NE ASSOCIATED WITH APPROACHING STORM SYSTEM. STRATIFORM SNOW WILL
REDEVELOP AREAWIDE 08-12Z WED AND QUICKLY BECOME MODERATE WITH
WIDESPREAD IFR CONDITIONS BY 10-12Z. LIKEWISE...WINDS WILL BE
INCREASING FROM THE SOUTHEAST WITH GUSTS TO 25 KTS AT KRUT BY 12Z
WED.
12Z WEDNESDAY THROUGH SATURDAY...MODERATE TO BRIEFLY HEAVY SNOW IS
EXPECTED 12-18Z WEDNESDAY...FOLLOWED BY A MIX OF SLEET AND RAIN
BEFORE STEADY PCPN ABATES TOWARD EVENING WITH LINGERING AREAS OF
DRIZZLE. WINDS SHIFT INTO THE WEST WEDNESDAY NIGHT ALLOWING FOR
SCATTERED SNOW SHOWER ACTIVITY AS COLDER AIR WORKS BACK INTO THE
REGION. GUSTY SELY WIND CONDITIONS ARE ALSO EXPECTED MUCH OF WED
AND WED NIGHT...ESPECIALLY AT KRUT...WITH SELY GUSTS 40+KT POSSIBLE.
LOW PRES DEPARTS TO THE NORTH ON THURSDAY WITH STRONG WEST WINDS
DEVELOPING 15-25 KT WITH GUSTS 30 KT AND SCATTERED SNOW SHOWER
ACTIVITY PRODUCING LOCALIZED IFR CONDITIONS. A FEW SNOW SHOWERS
MAY LINGER INTO FRIDAY. VFR ON SATURDAY...AS A RIDGE OF HIGH
PRESSURE BUILDS BACK INTO THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING
FOR VTZ003-004-006>008-010-012-019.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM EST WEDNESDAY FOR
VTZ001-002-005-009-011-016>018.
HIGH WIND WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR VTZ016>019.
NY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY EVENING
FOR NYZ029>031-034.
WINTER WEATHER ADVISORY FROM 4 AM TO 10 PM EST WEDNESDAY FOR
NYZ026>028-035-087.
&&
$$
SYNOPSIS...MB
NEAR TERM...MB
SHORT TERM...MB
LONG TERM...BANACOS
AVIATION...BANACOS
