FXUS61 KBTV 261224
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
724 AM EST SAT DEC 26 2009
.SYNOPSIS...
A FRONTAL BOUNDARY WILL MOVE THROUGH THE REGION INTO
TONIGHT...SLOWLY CLEARING THE AREA DURING THE DAY ON SUNDAY. AN
UPPER LOW PRESSURE SYSTEM WILL FOLLOW THE FRONT ON MONDAY INTO
TUESDAY...KEEPING THE CHANCE FOR WINTRY PRECIPITATION OVER THE AREA
DURING THIS TIME. HIGH PRESSURE RETURNS FOR TUESDAY NIGHT INTO
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 508 AM EST SATURDAY...OCCLUDED FRNTL BOUNDARY CONTINUES TO
SLOWLY WORK NE INTO THE REGION THIS MORNING...WITH ITS PROGRESS
BEING SLOWED BY BLOCKING RIDGE. THIS HAS BEEN AIDING THE SITUATION
BY CONFINING AMT OF PRECIP TO MAINLY N NY WHERE CURRENT WARNINGS
ARE. DO EXPECT PRECIP TO SLOWLY TRUDGE ACROSS VT DURING THE
MORNING/EARLY AFTNOON HRS. SFC OBS AROUND THE AREA IN VCNTY OF
PRECIP REPORT A MIX OF -SW...CHANGING BACK AND FORTH TO -FZRA/PL
AND DO EPXECT THIS TO HAPPEN OVER THE CWA AS WELL. CURRENTLY MDLS
INDICATED A SPLIT ON AMT OF QPF FOR EVENT. KEY FOR THIS WILL BE
COASTL LOW DEVLEOPING OVER DELMARVA. IF THIS HUGS THE
COAST...PRECIP WILL BE ABLE TO FEED NORTHWARD ALONG BOUNDARY
PROLONGING EVENT OVER AREA. ANY MEANINGFUL SHIFT FURTHER OFFSHORE
WILL SHUNT MOISTURE AWAY FROM THE REGION...KEEPING TOTALS LGT.
HAVE LEANED FOR A BIT MORE PRECIP ATTM...BUT SFC TRACK WILL HAVE
TO BE WATCHED AS IT MAY AID IN SHUTTING DOWN WARN/ADV CURRENTLY IN
EFFECT. WITH PRECIP WANING AS IT PUSHES NORTHWARD INTO CWA HAVE
OPTED NOT TO ADD ANY ADDITIONAL ADVISORIES TO SOUTHERN VT. NOT
MANY REPORTS OF FZRA AND CURRENT FORECAST HAS GD MENTION OF MIXED
WINTRY PRECIP...BUT MAY ISSUE SPSBTV IF REPORTS DO COME IN. PRECIP
CHANGE WILL/SHOULD OCCUR OVER PORTIONS OF THE CWA...ESPECIALLY FOR
THE CHAMPLAIN VALLEY...IF WINDS INCR FROM THE SSE. HAVE CONTINUED
MENTION OF WIND GUSTS OVER 30-40MPH AS GRADIENT DEVELOPS LATER
TDY. THE INCR WINDS WILL ALSO HELP TO CHANGE OVER TO RAIN IN
PARTS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 508 AM EST SATURDAY...SUNDAY LOOKS TO BE THE TRANSITION ACROSS
THE CWA AS FRNTL BOUNDARY CLRS THE REGION TO THE EAST...AND ITS
ASSOCIATED UPPER LOW BEGINS MVG TOWARDS THE REGION ON MONDAY.
STILL SOME WAA MIXING IN WITH PRECIP AS FRNT EXITS REGION.
TRANSITION OF LEFT OVER MOISTURE TO ALL -SW WILL OCCUR AS COLDER
AIR WORKS SSE FROM CANADA. THIS WILL BE ENHANCED BY SHARP TROUGH
THAT WILL BEGIN TRANSIT WESTERN CWA ON MONDAY. SOME LK ENAHNCEMENT
WILL ALSO OCCUR SO WILL CONTINUE MENTION SNOW SQUALLS...KEEPING
CLOSE TO LIKELY POPS OVER N NY. SNOW COULD BE HEAVY AT TIMES AS
BOUNDARY DEVELOPS W/ ARCTIC AIR BEHIND IT..CAUSING SEVERAL INCHES
OF ACCUM. HAVE GONE BLW NORMAL FROM MDL GUIDANCE FOR HIGHS/LOWS
DUE TO EXTENSIVE CLD COVER FROM EVENT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 508 AM EST SATURDAY...SHARPLY DIGGING UPPER TROUGH AND ITS
ASSOCD ARCTIC FRONTAL BNDRY WILL SURGE SEWRD FROM ONTARIO/WRN
QUEBEC MONDAY EVENING. GOOD LLVL MSTR CONVERGENCE IN ADVANCE OF
THIS FAST MOVG BNDRY...SO EXPECT NUMEROUS SNOW SHWRS AND PSBL
SQUALLS... WITH SHARPLY FALLING TEMPS BEHIND THE FRONT ON GUSTY NW
WNDS. PCPN CHANCES WILL DECREASE LATE MONDAY NIGHT INTO TUESDAY AS
DRIER AIR ADVECTS INTO THE RGN. TEMPS TO BOTTOM OUT IN THE SINGLE
DIGITS IN MANY LOCATIONS EARLY TUESDAY WITH SOME WIND CHILL
CONCERNS PSBL OVER THE NRN MTNS. TEMPS ON TUESDAY WILL STRUGGLE TO
CLIMB FROM THE EARLY MORNING LOWS AS RGN WILL BE UNDER CONTD CAA
WITH 850 MB TEMPS -20 TO -25C. HIGH PRESSURE THEN BUILDS EASTWARD
TUE NIGHT INTO WED NIGHT WITH COLD AND DRY CONDITIONS EXPECTED. AS
HIGH MOVES OFF TO THE EAST...RETURN SOUTHERLY FLOW DEVELOPS BY
THURSDAY...RESULTING IN TEMPS MODERATING BACK TO NEAR SEASONAL
NORMS...ALONG WITH A CHC OF SNOW SHWRS...ESPECICALLY OVER NRN
ZONES. SOME UNCERTAINTY AS TO EVOLUTION OF UPPER TROUGH OVER THE
MIDWEST/NORTHEAST LATER IN THE WEEK...AND WHERE ANY ASSOCD SFC LOW
MAY TAKE SHAPE. BUT IT DOES APPEAR AS IF CHANCES FOR SOME SNOW OR
SNOW SHWRS WILL INCR FRI/SAT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...CHALLENGING AVIATION FCST NEXT 24 HOURS AS
OCCLUDED FRONT MOVES NORTHEAST INTO THE FORECAST AREA. CONDITIONS
RANGING FROM MVFR TO VFR ACROSS FORECAST AREA EARLY TODAY WITH
LOWEST CIGS AT KMPV/KRUT. EXPECT CONDITIONS TO LOWER TO MVFR/IFR
AT REMAINDER OF TAF SITES BY THIS AFTERNOON. A BIG AVIATION ISSUE
WILL BE PRECIPITATION TYPE. FREEZING RAIN HAS DEVELOPED ACROSS
MUCH OF NRN NY INCLUDING TAF SITES KMSS/KSLK. EXPECT THIS PCPN TO
SLOWLY ADVANCE NEWRD TODAY...ARRIVING AT REMAINDER OF TAF SITES
BTWN 15Z-21Z. PTYPE WILL LIKELY BE FZRA OR A MIX AT THE ONSET...
CHANGING TO JUST RAIN AT MOST SITES TONIGHT AS TEMPS CLIMB A BIT
ABOVE FREEZING. WINDS WILL BE GUSTY (G30 KTS) FROM THE SOUTHEAST
AT KRUT THRU THE PERIOD...AND FROM THE ENE (G25 KTS) AT KMSS
TODAY. OTHERWISE...WINDS WILL BE E-SE AT AROUND 10 KTS. RATHER
LOW CONFIDENCE IN PRECIP BEGIN TIME IN VERMONT AND IN CHANGEOVER
ACCURACY...SO STAY TUNED FOR UPDATES AS THE SITUATION UNFOLDS.
OUTLOOK...12Z SUNDAY THROUGH WEDNESDAY...
12Z SUN THRU 18Z SUN...MVFR W/OCNL IFR IN MIXED PCPN AS OCCLUDED
FRONT CROSSES AREA.
18Z SUN THRU 12Z MON...CONDITIONS IMPROVING TO MAINLY VFR EXCEPT
OCNL MVFR IN MTN SHSN...ESPECIALLY AT KSLK/KMPV.
12Z MON THRU 12Z TUE...VFR TRENDING MVFR/IFR IN SHSN/SQ AS UPPER
LOW AND STRONG COLD FRONT AFFECT THE REGION. GUSTY NORTHERLY WINDS
DEVELOPING AFTER 06Z TUE.
12Z TUE THRU 00Z WED...MAINLY VFR WITH SCT MVFR IN MTN SHSN...MAINLY
AT THE KSLK TERMINAL. GUSTY NORTHERLY WINDS.
00Z WED THRU 00Z THU...VFR WITH HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...WINTER WEATHER ADVISORY UNTIL 5 AM EST SUNDAY FOR NYZ029-030-
034-087.
WINTER STORM WARNING UNTIL 5 AM EST SUNDAY FOR NYZ026-027-031.
&&
$$
SYNOPSIS...JN
NEAR TERM...JN
SHORT TERM...JN
LONG TERM...RJS
AVIATION...RJS
