FXUS61 KBTV 221231
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
731 AM EST TUE DEC 22 2009
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION TODAY
THROUGH WEDNESDAY...ACCOMPANIED BY SOME LIGHT SNOW SHOWERS. HIGH
PRESSURE RETURNS TO THE REGION FOR THURSDAY AND CHRISTMAS DAY...
BEFORE A MORE SIGNIFICANT STORM AFFECTS THE AREA THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 335 AM EST TUESDAY...A MODERATE SHORTWAVE WILL BE TRACKING
THROUGH THE UPPER FLOW ACROSS THE REGION TODAY. LIGHT SNOW
SHOWERS HAVE PERSISTED OVERNIGHT ACROSS NORTHEAST VERMONT IN
RESPONSE TO MID LEVEL MOISTURE BACKING INTO THE AREA AND
CONTINUED NORTHWEST FLOW ALOFT. SNOW SHOWERS WILL CONTINUE ACROSS
NORTHEAST VERMONT THIS MORNING...THEN AS THE SHORTWAVE ENTERS THE
REGION SNOW SHOWER ACTIVITY SHOULD INCREASE IN COVERAGE...THOUGH
WILL STILL BE MAINLY CONFINED TO NORTHERN VERMONT...AND THE
UPSLOPE REGIONS OF THE NORTHERN ADIRONDACKS. SNOWFALL
ACCUMULATIONS ARENT EXPECTED TO BE MUCH WITH LOW LEVELS REMAINING
VERY DRY...BUT AREAS WITH THE MOST ACTIVITY SUCH AS THE NORTHEAST
KINGDOM OF VT WILL SEE A DUSTING TO 2 INCHES POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 335 AM EST TUESDAY... SNOW SHOWERS WILL CONTINUE TONIGHT
THROUGH WEDNESDAY AS THE SHORTWAVE SLOWLY SLIDES EAST. WITH
CONTINUED LIMITED LOW LEVEL MOISTURE...NO REAL ACCUMULATIONS ARE
EXPECTED EXCEPT IN NORTHEAST VERMONT WHERE A FEW ADDITIONAL
INCHES ARE POSSIBLE THROUGH THE PERIOD. PRECIPITATION SHOULD WIND
DOWN AFTER MIDNIGHT WEDNESDAY NIGHT AS THE SHORTWAVE FINALLY
MOVES OFF THE COAST OF NEW ENGLAND AND SURFACE HIGH PRESSURE
BEGINS TO BUILD INTO THE REGION FROM THE NORTH. ON THURSDAY...THE
UPPER LEVEL RIDGE AMPLIFIES OVER THE EASTERN GREAT LAKES AND WILL
PROVIDE THE AREA WITH LIKELY THE BEST DAY OF THE WEEK WITH SUNNY
SKIES AND TEMPERATURES MODERATING BACK TOWARDS SEASONAL NORMALS
IN THE LOWER TO MID 30S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 335 AM EST TUESDAY...ON CHRISTMAS DAY THE NORTH COUNTRY
WILL REMAIN UNDER THE INFLUENCE OF HIGH PRESSURE WITH GENERALLY
PARTLY SUNNY SKIES AND SEASONAL TEMPERATURES EXPECTED. MODELS
CONTINUE TO BE IN GOOD AGREEMENT REGARDING LOW PRESSURE SYSTEM TO
AFFECT THE AREA CHRISTMAS NIGHT INTO THE WEEKEND. LATEST TRENDS
ARE A BIT SLOWER THAN PREVIOUS RUNS...WITH MOST OF THE AREA NOT
REALLY SEEING MUCH IN THE WAY OF PRECIP AFTER MIDNIGHT FRIDAY.
PRIMARY LOW IS STILL EXPECTED TO LIFT OUT OF THE SOUTHERN PLAINS
ON THURSDAY INTO THE CENTRAL GREAT LAKES REGION FRIDAY...WITH A
SECONDARY LOW DEVELOPMENT NEAR THE MID ATLANTIC COAST FRIDAY
NIGHT INTO SATURDAY. WITH HIGH PRESSURE IN PLACE OVER EASTERN
CANADA FRIDAY NIGHT...COLD AIR WILL REMAIN IN PLACE AT THE ONSET
OF THE EVENT WITH PRECIPITATION WILL LIKELY BEGINNING AS SNOW.
BUT AS WARMER AIR ALOFT BECOMES ENTRAINED INTO THE SYSTEM...EXPECT
A CHANGEOVER FROM SNOW TO RAIN IN MOST AREAS ON SATURDAY. THERE IS
ALSO THE POSSIBILITY FOR SOME SLEET AND/OR FREEZING RAIN FRIDAY
NIGHT AS LOW LEVEL COLD AIR WILL BE DIFFICULT TO DISPLACE IN SOME
AREAS...PARTICULARLY ACROSS NORTHEAST VERMONT SO THIS WILL HAVE TO
BE MONITORED. ANY MIX WILL CHANGE TO SNOW SHOWERS SATURDAY NIGHT
AS COLDER AIR RETURNS. THE REGION WILL REMAIN UNDER THE INFLUENCE
OF AN UPPER TROUGH SUNDAY INTO MONDAY WITH CONTINUED CHANCES FOR
SNOW SHOWERS...AND TEMPERATURES TRENDING COLDER.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...EXPECTING MAINLY VFR CONDITIONS THROUGH
THE PERIOD...EXCEPT AREAS OF MVFR ACROSS NORTH CENTRAL AND
NORTHEAST VERMONT IN SCATTERED SNOW SHOWERS. AN UPPER LOW WILL
MOVE SOUTHEAST FROM CANADA TODAY AND WILL MOVE ACROSS THE REGION
THIS AFTERNOON. THIS UPPER LOW HAS A VERY COLD POOL OF AIR ALOFT
ASSOCIATED WITH IT...SO EXPECTING AN INCREASE IN CLOUD COVER THIS
AFTERNOON ACROSS NORTHERN NEW YORK...THE CHAMPLAIN VALLEY AND
SOUTH CENTRAL VERMONT. ANY SNOW SHOWER ACTIVITY WITH THIS UPPER
LOW WILL BE SCATTERED...SO HAVE INDICATED SNOW SHOWERS IN THE
VICINITY IN THE TAF FORECASTS.
OUTLOOK...12Z WEDNESDAY THROUGH SATURDAY...AN UPPER LEVEL TROUGH
MOVES SLOWLY ACROSS REGION THROUGH WEDNESDAY WILL PRODUCE
SCATTERED SNOW SHOWERS AND POSSIBLE MVFR CONDITIONS...ESPECIALLY
OVER THE HIGHER TERRAIN TAF SITES. VFR CONDITIONS EXPECTED
THURSDAY THROUGH MUCH OF FRIDAY AS REGION WILL BE UNDER A RIDGE OF
HIGH PRESSURE. LOW PRESSURE WILL BRING LOWERING CEILINGS AND
VISIBILITIES IN PRECIPITATION FRIDAY NIGHT INTO SATURDAY. EXPECT
CONDITIONS TO LOWER TO MVFR AND POSSIBLY IFR IN MIXED
PRECIPITATION.
&&
.EQUIPMENT...
THE TEMPERATURE AND DEW POINT SENSORS AT THE AUTOMATED SURFACE
OBSERVING SYSTEM (ASOS) AT SARANAC LAKE NEW YORK (KSLK) HAVE BEEN
MALFUNCTIONING AND HAVE BEEN TEMPORARILY TURNED OFF. AN
ELECTRONICS TECHNICIAN IS SCHEDULED TO VISIT THE SITE LATER TODAY
TO ATTEMPT REPAIRS OF THESE SENSORS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...LAHIFF
SHORT TERM...LAHIFF
LONG TERM...LAHIFF
AVIATION...WGH
EQUIPMENT...WFO BTV
