FXUS61 KBTV 151208
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
708 AM EST TUE DEC 15 2009
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE OVER THE SAINT LAWRENCE VALLEY
THIS MORNING WILL MOVE NORTHEAST INTO NORTHERN MAINE BY THIS EVENING.
THIS LOW WILL BRING AN ARCTIC COLD FRONT THROUGH THE REGION THIS
MORNING WITH A FEW SHOWERS. SIGNIFICANTLY COLDER COLDER AIR WILL
MOVE INTO THE NORTH COUNTRY BEHIND THIS FRONT WITH BELOW COLD
BLUSTERY CONDITIONS EXPECTED THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 431 AM EST TUESDAY...LIGHT SCATTERED SHOWERS AND DRIZZLE
CONTINUE IN THE NORTH COUNTRY THIS MORNING. THE MORE ORGANIZED SHOWERS
ASSOCIATED WITH WARM AIR ADVECTION HAVE LIFTED EAST. SOME DRIZZLE
AND FREEZING DRIZZLE LINGER WITH AMPLE LOW LEVEL MOISTURE OVER THE REGION.
THE COLD FRONT IS NOW ACROSS WESTERN NEW YORK. SHOWERS ALONG THE
FRONT ARE BEGINNING TO STREAM INTO THE NORTH COUNTRY...BUT THESE
ARE LIMITED IN NATURE. THUS THE POTENTIAL FOR SHOWERS WILL BE
LIGHT AND GENERALLY SCATTERED IN NATURE TODAY. PRECIPITATION TYPE
IS A BIT OF A TRICK THIS MORNING. AS SOUTHERLY WINDS CONTINUE IN
THE CHAMPLAIN VALLEY..TEMPERATURES HAVE WARMED INTO THE MID TO
UPPER 30S. THESE TEMPERATURES WILL SUPPORT LIQUID PRECIPITATION.
HOWEVER...TEMPERATURES OUTSIDE OF THE CHAMPLAIN VALLEY...AND EVEN
SHELTERED AREAS NEAR THE CPV...REMAIN NEAR OR BELOW FREEZING THIS
MORNING. THUS THE POTENTIAL FOR A SLICK COMMUTE...AS TEMPERATURES
JUST ABOVE THE SURFACE CONTINUE TO WARM THIS MORNING WITH OUR
SOUTHWESTERLY FLOW. LUCKILY PRECIPITATION WILL BE VERY LIGHT...AND
AS MENTIONED MORE IN A DRIZZLE FORM THROUGH MORNING. THE LATEST
RUN OF THE RUC GUIDANCE SUGGESTS THE COLD FRONT SHOULD BE ACROSS
THE MID SECTION OF THEN NORTH COUNTRY BY THIS AFTERNOON....THOUGH
THE POTENTIAL FOR SHOWERS WILL LINGER UNTIL THE UPPER LEVEL TROUGH
PASSES THE REGION. THIS WILL OCCUR OVERNIGHT TONIGHT. WITH THE
FRONTAL PASSAGE OCCURRING MIDDAY... EXPECT TEMPERATURES TO RISE
ONLY LITTLE THIS AFTERNOON. TEMPERATURES WILL REMAIN FAIRLY FLAT
THIS AFTERNOON THEN COOL QUICKLY TOWARD EVENING AS THE COLDER AIR
MOVES INTO THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 431 AM EST TUESDAY...THE POTENTIAL FOR SCATTERED SHOWERS
CONTINUES INTO THE EVENING...BUT WITH COLD AIR
ADVECTION...MOISTURE IN THE DENDRITIC ZONE WILL ALLOW FOR PRECIP
TO FALL IN THE FORM OF SNOW SHOWERS. BRIEFLY THIS EVENING THE
ADIRONDACKS AND PORTIONS OF THE NORTHERN GREENS COULD SEE BIT OF
LAKE SNOW SHOWER WITH THE COLD AIR ADVECTION PRIOR TO THE PASSING OF
THE UPPER TROUGH... AS THERE WILL BE A BRIEF OPEN DOOR OF
SOUTHWESTERLY FLOW. BUT...THE PASSING OF THE UPPER TROUGH BRINGS A
MORE WEST TO NORTHWESTERLY FLOW ACROSS THE REGION BEFORE
MIDNIGHT...WHICH WOULD PUT AN END TO ANY SUCH SHOWERS IN OUR AREA.
THIS NORTHWESTERLY FLOW WILL BRING MUCH DRYER AND COLDER AIR INTO
THE NORTH COUNTRY...THUS ANTICIPATING SOME BREAKS IN THE CLOUDS BY
MORNING. TEMPERATURES WILL FALL RAPIDLY THROUGH THE EVENING AND
NIGHT INTO THE TEENS AND SINGLE DIGITS.
AFTER THIS EVENING THE FOCUS SHIFTS FROM PRECIPITATION POTENTIAL TO
WIND AND COLD TEMPERATURES. AS THE SURFACE LOW PASSES TO OUR EAST
OVER THE CANADIAN MARITIMES...AND STRONG HIGH PRESSURE BEGINS TO
BUILD OVER THE OHIO VALLEY...THE PRESSURE GRADIENT WILL TIGHTEN
CONSIDERABLY OVER THE FORECAST AREA. ANTICIPATE NNW GUSTS OF 25
TO 35 MPH THOUGH MUCH OF THE NORTH COUNTRY. THIS WILL BRING SUBZERO
WINDCHILL TEMPERATURES IN THE DACKS AND NORTHEAST KINGDOM OF VT
TOWARD WEDNESDAY MORNING. TEMPERATURES WEDNESDAY WILL RUN ABOUT
8-10 DEGREES BELOW NORMAL. AS WINDS PERSIST AND TEMPERATURES
CONTINUE TO DROP WEDNESDAY NIGHT...SUBZERO WIND CHILL TEMPERATURES
ARE EXPECTED THROUGH OUT THEN NORTH COUNTRY WEDNESDAY NIGHT INTO
THRURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 310 AM EST TUESDAY...NO BIG WX SYSTEMS TO AFFECT THE NORTH
COUNTRY THRU THE EXTENDED PERIOD. MDLS BRING STAGNANT UPPER LOW
OVER THE CANADIAN MARITIMES THURSDAY NIGHT ON INTO FRIDAY...BACK WEST
ACROSS THE GREAT LKS REGION THRU THE WEEKEND...THEN BACK EAST
AGAIN FOR NEXT MONDAY AND TUESDAY. THIS PATTERN IS A BIT SLOWER IN
ECMWF VERSUS GFS...BUT GENERAL TREND THE SAME. WK SFC RIDGE DOES
TRY TO BUILD OVER THE AREA DURING THIS TIMEFRAME...BUT CWA WILL
SEE SL CHANCE FOR -SW AS UPPER LOW RETROGRADES TO THE GREAT LKS.
BULK OF PRECIP TO REMAIN ALONG THE OUTER TRACK OF THE
LOW(PINWHEELING AROUND IT)...WITH THE NORTHEAST REGION ON THE
DRIER SIDE. CD AIRMASS WILL WRAP AROUND CIRCULATION FOR FIRST HALF
OF EXTENDED...WHICH WILL TREND TEMPS NEARLY 10 DEGREES BLW NORMAL.
BY THE LATTER HALF...W/ UPPER LOW OVER THE GREAT LKS...SOME WAA
WILL WORK INTO AREA THAT LIFT OUT SOME HIR TEMPS...BUT WILL BE
LIMITED BY CLD COVER.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...COND WILL VARY THRU FORECAST PERIOD FROM
VFR DOWN TO IFR AT TIMES...ESPECIALLY FOR MPV/SLK WHERE CEILINGS
WILL DROP DOWN TO BLW OVC010 14Z TO 16Z. SOME FG AND -SHRASN
POSSBL THRU 18Z. AS WIND SHIFTS TO THE NW 5-10KT THIS
AFTNOON...CEILINGS WILL SLOWLY RISE FROM MVFR UP TO VFR.
OUTLOOK...12Z WEDNESDAY THROUGH FRIDAY... MAINLY VFR CONDITIONS
WITH POTENTIAL FOR SOME MTN -SW AND OCCASIONAL MVFR (SLK/MPV) WEDS
THRU FRI.
&&
.EQUIPMENT...
THE ASOS TEMPERATURE SENSOR AT SAINT JOHNSBURY VERMONT (1V4) HAS BEEN
RUNNING A BIT TOO WARM LATELY. IT GAVE A HIGH TEMPERATURE OF 43
DEGREES TODAY. OUR ELECTRONICS TECHNICIANS WILL VISIT THE SITE ON TUESDAY
TO DO MAINTENANCE WORK ON THIS SENSOR. SO...PLEASE USE THIS DATA
WITH CAUTION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...AMF
NEAR TERM...AMF
SHORT TERM...AMF
LONG TERM...JN
AVIATION...JN/SLW
EQUIPMENT...
