FXUS61 KBTV 272100
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
400 PM EST FRI NOV 27 2009
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO INTENSIFY AS IT MOVES INTO THE GULF
OF MAINE THIS EVENING AND THEN INTO EASTERN CANADA SATURDAY. THIS
STORM WILL BRING RAIN...HIGH ELEVATION SNOW...AND WIND TO THE
NORTH COUNTRY...WITH PRECIPITATION TAPERING OFF DURING THE DAY ON
SATURDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BRING A BREAK IN THE
ACTION ON SUNDAY WITH FAIR WEATHER EXPECTED. ANOTHER FRONTAL
SYSTEM WILL BRING MORE SNOW AND RAIN SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 350 PM EST FRIDAY...HAVE CONTD WITH WINTER WEATHER ADVISORY
FOR 3-7" OF WET SNOW TONIGHT INTO SATURDAY MORNING FOR ADIRONDACKS
AND GREEN MTNS EASTWARD...MAINLY ABOVE 1000 FT...WITH BULK OF
ACCUMULATION EXPECTED TO OCCUR TONIGHT.
983 MB SFC LOW LOCATED JUST EAST OF CAPE COD THIS AFTERNOON WILL
CONTINUE TO DEEPEN AS IT LIFTS NORTH INTO GULF OF MAINE THIS
EVENING. RADAR AND SFC OBS INDICATE WDSPRD PCPN ACRS
VERMONT...WITH LESS COVERAGE OVER NRN NY. EXPECT COVERAGE TO
CONTINUE TO INCR THRU THIS EVENING AS NEGATIVELY TILTED UPPER
TROUGH OVER THE NORTHEAST DEEPENS FURTHER WITH CONTD INFLUX OF
STRONG SHRTWV ENERGY. PTYPE ALL RAIN IN THE VLYS SO FAR...BUT SOME
SNOW MIXED IN OVER HIR TRRN...MAINLY ABOVE 1500 FT.
THE SNOW LEVEL WILL CONTINUE TO LOWER TONIGHT AS PCPN
CONTINUES...WITH SOME MDT TO PERHAPS HVY PCPN PSBL FOR A TIME THIS
EVENING WHEN MAX UVM OCCURS. BOUNDARY LAYER TEMPS STILL LOOK TOO
MILD TO SUPPORT MUCH SNOW IN THE VALLEYS...BUT THERE IS POTENTIAL
FOR SOME COLD AIR TO MIX DOWN ALLOWING FOR A MIX OR BRF CHANGEOVER
EVEN AT THE LOWEST ELEVATIONS WHEN PCPN IS HEAVIEST. HAVE GONE
WITH BLEND OF MODELS FOR QPF...WHICH RESULTS IN WDSPRD .5 TO 1.5
INCHES...WITH SOME LOCALLY HIR TOTALS OVER ERN VT AND LESS IN ST
LWR VLY. PCPN WILL GRADUALLY BECOME MORE DRIVEN BY OROGRPAHICS
OVRNGHT WITH INCRG NW FLOW AT ALL LEVELS. THE RESULT WILL BE THAT
HEAVIEST PCPN LATER TONIGHT INTO EARLY SATURDAY WILL OVER HIR
TRRN OF NRN VT. MIN TEMPS TONIGHT IN THE LOWER 30S OVER HIR TRRN
ZONES...BUT MID TO UPPER 30S IN THE VLYS RESULTING IN RAIN OR
VERY WET SNOW. SNOW LIQUID RATIOS PROBABLY 5 OR AT MOST 10:1 FOR
WET SNOW GENERALLY GIVE 3 TO 7 INCHES OF SNOW OVER THE HIR
TRRN...WITH HIR AMOUNTS OVER THE SUMMITS WHERE RATIOS AND QPF WILL
BE GREATER.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 350 PM EST FRIDAY...SNOW/RAIN EXPECTED TO GRADUALLY
DIMINISH IN COVERAGE SATURDAY...BEING MORE CONFINED TO HIR TRRN.
ANY LINGERING SNOW SHWRS COME TO AN END SATURDAY NITE AND GRADIENT
SLACKENS AS LOW PULLS FURTHER AWAY THRU ERN CANADA...AND WEAK
RIDGING DEVELOPS BY SUNDAY MORNING. RAINFALL AMOUNTS TONIGHT INTO
SATURDAY MORNING WILL RESULT IN MODERATE TO POSSIBLY SIGNIFICANT
RISES ON MANY RIVERS...BUT NO FLOODING EXPECTED. AS FOR THE
WINDS...THE STRONG N-NW WNDS WHICH DEVELOP THIS EVENING WILL
CONTINUE DURING SATURDAY. DON'T EXPECT THAT WE WILL MIX ALL THE 50
KT 850MB WINDS DOWN TO THE SURFACE...BUT EXPECT WIND GUSTS TO 40
MPH.
A RATHER TRANQUIL DAY ON SUNDAY WITH WEAK RIDGING. EXPECT DRY
CONDITIONS WITH TEMPS A BIT ABOVE SEASONAL NORMS. NEXT FRONTAL
SYSTEM APRCHS SUNDAY NIGHT. EXPECT INCRG CLDS WITH SNOW/RAIN SHWRS
LIKELY...MAINLY AFTER MIDNIGHT. ANY SNOW ACCUMULATIONS SHUD BE
LIGHT...AS QPF THRU 12Z MONDAY EXPECTED TO BE LESS THAN A QUARTER
INCH.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 210 PM EST FRIDAY...SHOWERS WILL CONTINUE ON MONDAY AS LOW
PRESSURE SYSTEM TRACKS NORTHEAST ALONG THE SAINT LAWRENCE
VALLEY...AND SHOULD BE ENDING BY LATE AFTERNOON. SOME WRAP AROUND
SNOW SHOWERS IN THE HIGHER TERRAIN IS EXPECTED MONDAY NIGHT.
UPPER LEVEL TROF WILL CROSS THE REGION MONDAY NIGHT. THEN AN
UPPER LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL BUILD OVER THE
EASTERN CONUS FOR TUESDAY AND TUESDAY NIGHT. A LOW PRESSURE
SYSTEM WILL PASS TO OUR NORTH ON WEDNESDAY...AND UPPER LEVEL TROF
WITH EMBEDDED SHORT WAVE WILL CROSS THE NORTH COUNTRY BRINGING
ANOTHER CHANCE FOR SHOWERS...ESPECIALLY ACROSS OUR NORTHERN
ZONES. ANOTHER LOW PRESSURE SYSTEM MAY FORM OFF THE CAROLINA
COAST ON THURSDAY...TRACKING NORTHEAST ALONG THE EAST COATS.
STILL LOTS OF UNCERTAINTY IN THE FORECAST BEYOND DAY 5.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...A LOW PRESSURE AREA OFF THE COAST OF MAINE
WILL CONTINUE TO MOVE NORTHEASTWARD THIS AFTERNOON AND EVENING.
CEILINGS HAVE LOWERED TO MVFR/IFR. COLDER AIR ALOFT HAS WORKED
INTO THE REGION AND RAIN HAS CHANGED TO SNOW ACROSS THE HIGHEST
ELEVATIONS. RAIN SHOULD CHANGE OVER TO SNOW AT SLK AND MPV
TONIGHT...WITH RUT A LITTLE LATER DURING THE OVERNIGHT. VALLEY
TERMINALS SHOULD HAVE ALL RAIN THROUGH THE END OF THE EVENT.
SURFACE WIND GUSTS AT OR ABOVE 20 KNOTS WILL DEVELOP THIS EVENING
ACROSS THE REGION...AND CONTINUE THROUGH 18Z SATURDAY.
OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY...SATURDAY...GUSTY
NORTHWEST WINDS. SUNDAY...MAINLY VFR...AS A WEAK RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION. SUNDAY NIGHT...MVFR/IFR
CONDITIONS IN LIGHT SNOW TO DEVELOP ACROSS THE REGION.
MONDAY...MVFR/IFR IN RAIN AND SNOW SHOWERS...AS A COLD FRONT
MOVES INTO THE REGION. TUESDAY...MVFR/IFR IN LIGHT SNOW POSSIBLE
AS A WARM FRONT APPROACHES THE REGION. WEDNESDAY...MVFR IN LIGHT
SNOW SHOWERS ACROSS THE NORTHERN AREAS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 11 AM EST SATURDAY FOR VTZ003-
004-006>008-010-012-016>019.
NY...WINTER WEATHER ADVISORY UNTIL 11 AM EST SATURDAY FOR
NYZ029>031-034.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS
SHORT TERM...RJS
LONG TERM...NEILES
AVIATION...NEILES
