FXUS61 KBTV 112104
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
404 PM EST FRI DEC 11 2009
.SYNOPSIS...
LAKE EFFECT SNOWS WILL CONTINUE TO IMPACT PORTIONS OF THE NORTH
COUNTRY THIS EVENING WITH ACCUMULATING SNOWS...ESPECIALLY OVER PORTIONS
OF THE NORTHERN ADIRONDACKS AND SOUTH CENTRAL VERMONT. SNOW
SHOWERS WILL DIMINISH THROUGH THE NIGHT. EXPECT GUSTY WEST WINDS
AGAIN TONIGHT. BELOW NORMAL TEMPERATURES WILL CONTINUE
SATURDAY WITH QUIETING WEATHER UNDER HIGH PRESSURE. ON SUNDAY A
STORM SYSTEM WILL MOVE INTO THE NORTHEAST...WHICH LOOKS TO BRING A
MIXTURE OF PRECIPITATION TO THE NORTH COUNTRY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 326 PM EST FRIDAY...LAKE EFFECT SNOWS FROM TWO ORIGINS
CONTINUE TO IMPACT THE NORTH COUNTRY THROUGH THIS EVENING. THE PRIMARY
BAND...OFF OF LAKE ONTARIO...CONTINUES TO IMPACTING THE SOUTHERN
PORTIONS OF ESSEX CO NY...AS WELL AS THE WEST FACING SLOPES OF
THE SOUTHERN AND CENTRAL GREEN MOUNTAINS. WE ARE CONTINUING THE
WINTER WEATHER ADVISORY FOR THESE AREAS THROUGH 7 PM. AS THE FLOW
CONTINUES TO PUSH THE BAND SOUTH SHOW FALL RATES WILL DIMINISH IN
THESE AREAS THIS EVENING. THE SECOND ORIGIN OF SNOW SHOWERS COMES
FROM LAKE HURON...AND IS NOW IMPACTING NEARLY THE REST OF THE
FORECAST AREA WITH SCATTERED SNOW SHOWERS...MAINLY IN HIGHER
TERRAIN. WITH DRYING CONDITIONS THESE SHOWERS WILL BEGIN TO LOSE
THEIR PUNCH...THUS ADDITIONAL ACCUMULATIONS WILL ONLY AMOUNT TO A
DUSTING TO 3 INCHES...WITH HIGHEST AMOUNTS IN THE SOUTHERN AND
CENTRAL PORTIONS OF THE WEST FACING SLOPES OF THE GREENS AND
PORTIONS OF THE ADIRONDACKS.
WITH THAT DRYER AIR MOVING IN...CLOUD COVER WILL ALSO BEGIN TO
DIMINISH. THIS WILL ALLOW OUR TEMPERATURES TO DROP TO THE TEENS
AND SINGLE DIGITS THROUGHOUT THE FORECAST AREA. AND WHILE THE
GRADIENT RELAXES OVERNIGHT...WINDS WILL CONTINUE TO BE REALIZED AT
THE SFC...THUS INHIBITING OUR ABILITY TO RADIATE FULLY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 441 AM EST FRIDAY...HIGH PRESSURE FROM BEGINS TO MOVE INTO
THE REGION FROM OUR SOUTHWEST TOMORROW. THIS WILL PUT A
SOUTHWESTERLY FLOW OVER THE ST. LAWRENCE VALLEY SATURDAY...WHICH
COULD PUSH ANY LINGER LAKE ONTARIO SNOWS IN TO THIS AREA.
HOWEVER...SUBSIDENCE WILL INHIBIT SHOWER GROWTH...SO THE FORECAST
REFLECTS JUST A FEW SCATTERED SHOWERS...AND MAINLY IN THE SOUTHERN
PORTIONS OF THE ST. LAWRENCE. ELSEWHERE...ANY SNOW SHOWERS WILL BE
SCATTERED AND SHOULD BE RELEGATED TO THE HIGHER TERRAIN. WITH THIS
DRYER AIR WORKING INTO THE REGION WE WILL SEE SOME NICE BREAKS IN
THE CLOUDS. WITH SOUTHWEST FLOW WE WILL WARM AIR TRY TO WORK INTO
THE REGION LATE SATURDAY NIGHT. BUT WITH DRY CONDITIONS...AND A
LACK OF CLOUD COVER...TEMPERATURES WILL STILL BE QUITE COOL. AS
THE WARM AIR ADVECTION MOVES INTO THE REGION...AND A SHORTWAVE
TROUGH APPROACHES FROM THE WEST...WE WILL BEGIN TO SEE
PRECIPITATION MOVE INTO THE REGION FROM THE WEST SOUTHWEST ON
SUNDAY. BY MIDDAY SUNDAY IT LOOKS LIKE PRECIPITATION COULD BE
WIDESPREAD ACROSS THE NORTH COUNTRY...THEN EXITING THE REGION
SUNDAY NIGHT. AS TEMPERATURES CONTINUE TO WARM WITH THE ONSET OF
PRECIP WE COULD BE IN FOR A MIXTURE OF PRECIPITATION. AS THIS
WILL BE ON THE HEELS OF A COLD NIGHT...WE WILL HAVE TO MONITOR
THE PROGRESSION OF WARM AIR ALOFT AND ITS ABILITY TO MIX DOWN TO
THE SURFACE PRIOR TO THE ONSET OF PRECIPITATION. RIGHT NOW THE
FORECAST REFLECTS A MIXTURE OF RAIN AND SNOW...FAVORING A SOLUTION
WHICH KEEPS AIR ALOFT COOLER...THOUGH THERE EXISTS THE POTENTIAL FOR
SLEET AND POSSIBLY FREEZING RAIN ESPECIALLY IN NORTHEAST VT. THE
AMOUNT OF WARM AIR VS COLD AIR ALOFT WILL LARGELY DEPEND ON THE
PLACEMENT OF A SFC LOW THAT WILL DEVELOP OFF THE DELMARVA
PENINSULA SUNDAY. THE FASTER THIS SECONDARY LOW DEVELOPS AND
PROGRESSES EAST THE COLDER THE AIR ALOFT WILL REMAIN...THUS
DIMINISHING CONCERNS FOR AN ICY MIX.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 229 PM EST FRIDAY...HIGH PRESSURE BUILDS OVER THE NORTH
COUNTRY DURING THE DAY MONDAY AS LOW PRESSURE SYSTEM EXITS OFF
THE NEW ENGLAND COAST. SOME MDL TIMING ISSUES AS TO MVMNT OF LOW
WITH GFS BEING A BIT MORE PROGRESSIVE IN TAPERING PRECIP OFF. SOME
LGT --SW POSSBL OVER HIR TRRN DURING MORNING HRS...BUT WILL
QUICKLY DISSIPATE AS RIDGE CRESTS OVER THE REGION. BY MON
NGT...RIDGE SLIDES N AND E OF THE REGION AS SFC LOW SWINGS ACROSS
THE GREAT LKS REGION. SOME WAA AHEAD OF PRECIP ON SOUTHERLY WINDS.
MDLS HINT AT WARM AIR PROTRUSION INTO SOUTHERN AREAS AND MAY BE
SW/RW MIX. CD AIR AT SFC AT ONSET SHOULD KEEP MOSTLY -SW. CD AIR
COMING IN ON BACKSIDE OF LOW WILL KEEP PRECIP AS -SW. THIS SFC LOW
AND ITS UPPER ASSOCIATED LOW WILL STALL OVER THE CANADIAN
MARITIMES WEDNESDAY INTO FRIDAY...SETTING UP A 3-DAY STRETCH OF
BLW NORMAL TEMPS WITH PERSISTENT NNW FLOW. BECAUSE OF SFC FLOW
SETUP...PERSISTENT WRAP-AROUND/UPSLOPE -SW WILL ENSUE DURING THIS
TIME...MAINLY FOR NORTHERN HIR TRRN AREAS. QPF WILL WANE SOMEWHAT
THOUGH BY FRIDAY AS SFC RIDGE BUILDS EAST OUT OF CENTRAL U.S. THIS
WILL ONLY HELP TO ENHANCE GRADIENT OVER THE REGION BFR TAPERING
OFF BY NEXT WEEKEND.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...REGION WILL SEE A MIX OF VFR/MVFR/IFR
CONDITIONS THRU 00Z SAT AS LK EFFECT CLDS/-SW MV THRU THE AREA.
LOWEST CEILINGS WILL BE OVER SLK/MPV OVC010 AND BLW DURING THIS
TIME...OTHERWISE BKN015-BKN050. VSBY 4-6SM W/ LESS THAN 2-3SM AT
TIMES OVER SLK/MPV. AFT 00Z SAT...MAINLY VFR AS SKIES BEGIN TO SCT
OUT WITH HIGH PRESSURE BUILDING OVER AREA. SLK/MPV WILL SEE MVFR
CEILINGS BKN020-030 WITH SOME FLURRY ACTIVTY. WINDS GENERALLY
REMAIN WSW TO WNW 10-20KTS WITH SOME GUSTS TO NEAR
30KTS...ESPECIALLY BFR 00Z SAT.
OUTLOOK...18Z SATURDAY THROUGH TUESDAY...
12Z SAT-12Z SUN...MAINLY VFR UNDER HIGH PRESSURE. 12Z SUN-12Z
MON...AREAS OF MVFR IN LIGHT SNOW. 12Z MON-06Z TUE...MAINLY VFR.
06Z TUE-00Z WED...AREAS OF MVFR IN SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VTZ018-
019.
NY...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ034.
&&
$$
SYNOPSIS...AMF
NEAR TERM...AMF
SHORT TERM...EVENSON
LONG TERM...JN
AVIATION...EVENSON/JN
