FXUS61 KBTV 241732
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1232 PM EST THU DEC 24 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE NORTH COUNTRY THROUGH
FRIDAY...FOLLOWED BY A LARGE AREA OF LOW PRESSURE AND ITS ASSOCIATED
FRONTAL BOUNDARY. THIS SYSTEM WILL AFFECT THE AREA THROUGH NEXT
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 951 AM EST THURSDAY...WITH STRONG LOW-LEVEL INVERSION IN
PLACE AND LOW SUN ANGLE...IT WILL BE DIFFICULT TO ERODE THE
PREVAILING LOW OVERCAST TODAY - EVEN AS RIDGE AXIS BUILDS IN FROM
THE WEST THIS AFTERNOON.
BEST CHANCE FOR SOME SUNNY BREAKS WILL ACTUALLY BE ACROSS THE
HIGHER TERRAIN THIS AFTERNOON /ABOVE THE INVERSION/...AND ACROSS
S-CENTRAL VT. HAVE INCREASED CLOUD COVER IN THE GRIDS THROUGH THIS
EVENING AND MAINTAINED A CHANCE FOR LIGHT SNOW SHOWER ACTIVITY OR
FLURRIES. CHARACTER OF THE SNOWFLAKES WILL BE FINE NEEDLES AS
TEMPERATURES ALOFT HAVE WARMED OUT OF THE DENDRITE GROWTH ZONE.
DO NOT FORESEE ANY ACCUMULATION...BUT THERE COULD BE SOME REDUCED
VSBY AT TIMES IN LIGHT SNOW SHOWERS AND FOG. WITH LACK OF SUN...
STAYED BELOW MAV GUIDANCE WITH HIGH TEMPERATURES GENERALLY IN THE
LOWER 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 419 AM EST THURSDAY... FRIDAY WILL BE WX TRANSITION DAY OVER
THE AREA. HIGH PRESSURE CONTINUES TO LIFT N AND E AWAY FROM THE
CWA...ALLOWING FOR STRONG SSE GRADIENT TO SET UP AHEAD OF FRNTL
BOUNDARY. THIS FRNT AND ITS ASSOCIATED SFC LOW SETS UP OVER THE
CENTRAL PLAINS...MEANDERING DUE TO BLOCKING RIDGE IN THE EAST.
THIS WILL SLOW PROGRESSION OF SYSTEM THRU THE NORTHEAST...WHICH
MDLS HAVE SHOWN OVR PAST SEVERAL DAYS. FRNT EVENTUALLY BECM
OCCLUDED...WITH DRY AIR WORKING IN BETWEEN IT AND ITS PARENT LOW.
PRECIP WILL BEGIN TO WORK INTO AREA IN SW ZONES FRI NGT AND
OVERSPREAD REST OF AREA SAT MORNING. PROBLEM INITIALLY WILL BE LL
CD AIR IN PLACE AT PRECIP ONSET. ALL MDLS HAVE HINTED AT WINTRY
MIX TO START. TEMP PROFILES SHOW POTENTIAL FOR SLEET/FR RAIN/SNOW
BFR GOING TO RAIN IN VALLEY LOCALES AS TEMPS WARM UP. BECAUSE FRNT
IS OCCLUDED AND VERY SLOW MVG...QPF WILL BE LIMITED...THUS KEEPING
AMTS OF MIXED PRECIP DOWN. BULK OF PRECIP EXPECTED BY SAT
NGT...AND WILL EVENTUALLY TREND BACK TO ALL SNOW/SNOW SHOWERS WITH
CD AIR COMING IN ON BACK SIDE OF FRNT. OTHER ISSUE WITH THIS
SYSTEM WILL BE POTENTIAL FOR STRONG WINDS ON TIGHT SSE GRADIENT.
DACKS/WESTERN VT SLOPES(HIR ELEV) HAVE BEST POTENTIAL TO SEE WIND
GUSTS NEAR 40-60MPH AND MAY HAVE TO BE MONITORED FOR ANY WIND
PRODUCT ISSUANCE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 441 AM EST THURSDAY...PRIMARY LOW EXPECTED TO LIFT NORTH
THROUGH CENTRAL GREAT LAKES REGION SATURDAY NIGHT...WITH WEAK
SECONDARY LOW ALONG MID ATLANTIC COAST...WHICH THEN TRACKS UP INTO
GULF OF MAINE DURING SUNDAY. OCCLUDED FRONTAL BOUNDARY ASSOCIATED
WITH THESE SYSTEMS LIFTS SLOWLY NORTHEAST ACROSS FORECAST AREA
SATURDAY NIGHT INTO SUNDAY. MEANWHILE...HIGH PRESSURE REMAINS IN
PLACE OVER EASTERN CANADA SATURDAY NIGHT...RETREATING FURTHER TO
THE NORTHEAST ON SUNDAY. MILDER AIR IN THE MID LEVELS STREAMS IN
SATURDAY NIGHT ON 50-60 KT S-SE JET...BUT LOW LEVEL COLD AIR WILL
BE DIFFICULT TO DISPLACE...ESPECIALLY EAST OF THE GREENS AND
PERHAPS THE ST LWR VLY. EXPECT MIXED PRECIPITATION SATURDAY
NIGHT...WITH SOME LIGHT ACCUMULATIONS OF SNOW/SLEET OR ICE EXPECTED
IN AFOREMENTIONED AREAS. IN SRN ADRNDKS AND MUCH OF CHMPLN
VLY...MIXED PCPN SHOULD CHANGE TO MAINLY RAIN SATURDAY NIGHT.
PRECIP CHANGES TO MAINLY RAIN SUNDAY ALL LOCATIONS SUNDAY...BUT AS
COLDER AIR RETURNS DURING THE AFTERNOON AND AT NIGHT...EXPECT A
CHANGE BACK TO SNOW SHOWERS. POTENTIAL FOR SOME STRONG GUSTY
DOWNSLOPING WINDS (GUSTS 40-60 MPH PSBL) CONTINUES SAT NITE INTO
SUNDAY MORNING ALONG WESTERN SLOPES OF GREEN MOUNTAINS. AS FOR
TEMPS...EXPECT NEAR STEADY OR SLOWLY RISING TEMPS SATURDAY
NIGHT...THEN HIGHS ON SUNDAY MOSTLY IN THE MID TO UPPER 30S.
EXPECT A CONTD CHC OF SNOW SHWRS SUNDAY NIGHT AS COLD FRONT PUSHES
EAST OF FORECAST AREA. UPPER LOW OPENS UP DURING MONDAY AS IT
CROSSES THE NORTHEAST. ANOTHER STRONG SHRTWV AND ASSOCD ARCTIC
FRONT APRCH FROM THE GRTLKS MONDAY AND MOVE ACRS THE FORECAST AREA
MONDAY NIGHT. THE RESULT WILL BE A CONTD CHC OF SNOW SHWRS WITH
POTENTIAL FOR SOME SNOW SQUALLS...ESPECIALLY WITH PASSAGE OF UPPER
TROUGH AND FRONTAL BOUNDARY. TEMPS BEHIND THIS FRONT WILL FALL TO
WELL BELOW NORMAL (15-20 DEGREES BELOW NORMAL) ALONG WITH GUSTY NW
WNDS. HIGH PRESSURE BRINGS MAINLY DRY WX TO THE REGION WED/THURS.
TEMPS REMAIN BELOW NORMAL FOR THE REST OF THE PERIOD...ALTHOUGH
THEY WILL MODERATE A BIT THURSDAY AS THE CORE OF THE COLD AIR
DEPARTS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...DESPITE HIGH PRESSURE BUILDING INTO THE
REGION...STRONG LOW LEVEL INVERSION AND AMBIENT MOISTURE WILL ALLOW
LOW CLOUDS TO HANG TOUGH ACROSS THE REGION THROUGH MUCH OF THE
PERIOD. COULD SEE A FEW BREAKS TO VFR THIS AFTERNOON AS WEAK LATE
DECEMBER SUN ATTEMPTS TO BURN THIS OFF...OTW EXPECT WIDESPREAD MVFR
TO OCCNL IFR CIGS UNDER LIGHT/VRB WIND FLOW THROUGH 00Z. BY
TONIGHT...LIGHT/VRB FLOW CONTINUES ALONG WITH MVFR/IFR CIGS AND
VSBYS IN BR. THIS SHOULD SLOWLY BEGIN TO LIFT/ERODE TOWARD THE END
OF THIS FCST CYCLE BY FRIDAY AFTERNOON.
OUTLOOK...18Z FRIDAY THROUGH TUESDAY...
18Z FRI THRU 12Z SAT...MAINLY VFR W/HIGH PRESSURE...BUT SOME LOW
CLOUDS WITH MVFR CONDITIONS ARE POSSIBLE...ESPEC AT BTV/RUT/PBG
EARLY IN THE PERIOD.
12Z SAT THRU 18Z SUN...VFR W/OCNL MVFR/IFR IN MIXED PCPN AS
OCCLUDED FRONT CROSSES AREA.
18Z SUNDAY THRU 12Z MONDAY...MAINLY VFR EXCEPT OCNL MVFR IN MTN
SHSN...ESPECIALLY AT KSLK/KMPV.
12Z MONDAY THRU 12Z TUE...VFR TRENDING MVFR/IFR IN SHSN/SQ AS UPPER
LOW AND STRONG COLD FRONT AFFECT THE REGION.
12Z TUE THRU 00Z WED...MAINLY VFR WITH SCT MVFR IN MTN SHSN...MAINLY
AT THE KSLK TERMINAL.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...BANACOS/JN
SHORT TERM...JN
LONG TERM...RJS
AVIATION...JMG
