FXUS61 KBTV 261738
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1238 PM EST SAT DEC 26 2009
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL BE SLOW TO MOVE ACROSS THE
REGION OVER THE NEXT FEW DAYS. THIS FEATURE WILL BRING A VARIETY OF
PRECIPITATION TO THE REGION THIS WEEKEND...THEN SNOW SHOWERS FOR
EARLY NEXT WEEK. HIGH PRESSURE WILL RETURN TO THE NORTH COUNTRY
TUESDAY NIGHT FOR DRIER...BUT COLDER WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1013 AM EST SATURDAY...WILL MAKE MINOR TWEAKS TO THE
FORECAST BASED ON CURRENT RADAR TRENDS AND TEMPERATURE
TRENDS...WHICH WILL HAVE AN IMPACT ON PRECIPITATION TYPE.
ESSENTIALLY LOOKING AT FREEZING RAIN EVENTUALLY LIFTING NORTH OF
NORTHERN NEW YORK...BUT MORE PRECIPITATION MOVING BACK IN FROM THE
SOUTH LATER THIS AFTERNOON. TEMPERATURES WILL STILL BE CLOSE TO
FREEZING...SO WILL CONTINUE ADVISORIES AND WARNINGS FOR NOW AND
ADD TIMING INTO THE ZONES TO ACCOUNT FOR THE TWO PRECIPITATION
REGIMES. FOR VERMONT...JUST LOOKING AT SCATTERED LIGHT
PRECIPITATION THIS MORNING AND PRECIPITATION SHOULD INCREASE IN
AREAL COVERAGE LATER TODAY. SHOULD BE RAIN FOR THE CHAMPLAIN
VALLEY AND MIXED ELSEWHERE. PRECIPITATION AMOUNTS STILL LOOK TO BE
ON THE LIGHT SIDE. DYNAMIC SUPPORT INCREASES TONIGHT FOR
WIDESPREAD PRECIPITATION OVER THE AREA AND STILL DEALING WITH
TEMPERATURE PROFILE CONDUCIVE TO MIXED PRECIPITATION OVER CENTRAL
AND EASTERN VERMONT AND PARTS OF NORTHERN NEW YORK.
&&
.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 ENHANCEMENT
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...ESPECIALLY 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 /18Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...COMPLICATED AVIATION FORECAST FOR THE FIRST 24
HOURS. MAIN CONCERN IS PRECIPITATION TYPE AS SURFACE TEMPERATURES
WILL BE CLOSE TO FREEZING THROUGH AT LEAST EARLY TONIGHT. CURRENT
TEMPS ARE VERY VARIED DEPENDING ON LOCATION...WITH SAINT LAWRENCE
VALLEY NEAR FREEZING...THE ADIRONDACKS AND CHAMPLAIN VALLEY IN THE
MID 30S...AND THE GREEN MOUNTAINS AND EASTERN VERMONT STILL IN THE
UPPER 20S TO LOWER 30S. A WIDE BAND OF PRECIPITATION STRETCHING
ACROSS THE CENTRAL ADIRONDACKS WILL CONTINUE TO TREK NORTHWARD AND
WILL MOVE ACROSS THE TAF SITES 18Z THROUGH 05Z. THIS SHOULD FALL AS
A MIXTURE OF PRECIP TYPES. EVEN THE WARMER PLACES EXPECT SOME ICE
PELLETS TO MIX IN WITH RAIN. KMSS/KMPV/KRUT HAVE THE POTENTIAL TO
SEE A PROLONGED PERIOD OF FREEZING RAIN WITH THIS ACTIVITY. THINGS
BECOME EVEN MORE COMPLICATED THIS EVENING AND OVERNIGHT AS A BAND OF
850MB TEMPS 1-3C SLIDE EASTWARD ACROSS THE FORECAST AREA. THIS WILL
TURN MOST PRECIPITATION TO A MIX OF RAIN AND SLEET AND EVENTUALLY
ALL RAIN. APPROXIMATE TIME OF CHANGEOVER TO ALL RAIN...KMSS
13Z...KSLK 08Z...KRUT 06Z...KBTV/KPBG 09Z...KMPV 11Z. IN ADDITION TO
THE PRECIP CONCERNS...OVERALL CONDITIONS WILL DROP TO IFR OR LOWER
AT ALL SITES AS CEILINGS WILL BE 500 FT TO 1500 FT. EXPECT THE WORST
CONDITIONS TO BE IN THE MOUNTAINS AND SAINT LAWRENCE VALLEY. WINDS
WILL BE GUSTY AS WELL...ESPECIALLY AT KRUT WHERE GUSTS OF 30+ KTS
WILL BE POSSIBLE THROUGH 22Z...GRADUALLY TAPERING OFF THEREAFTER.
OVERALL...WINDS WILL BE EAST TO SOUTHEAST AT 10-20 KTS THROUGH THIS
EVENING THEN WILL SUBSIDE BY MIDNIGHT.
18Z SUNDAY THROUGH THURSDAY...
SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...MVFR WITH IFR POSSIBLE AT
THE MOUNTAIN SITES AS RAIN SHOWERS CHANGE TO SNOW.
MONDAY THROUGH MONDAY NIGHT...MVFR WITH PERIODS OF IFR IN SNOW
SHOWERS. SNOW SQUALLS POSSIBLE MONDAY AFTERNOON AND EVENING.
TUESDAY THROUGH THURSDAY...MAINLY VFR AS HIGH PRESSURE BUILDS INTO
THE REGION. A FEW LIGHT MOUNTAIN SNOW SHOWERS POSSIBLE TUESDAY
MORNING.
&&
.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...EVENSON
NEAR TERM...EVENSON
SHORT TERM...JN
LONG TERM...RJS
AVIATION...MB
