Area Forecast Discussion
Issued by NWS Burlington, VT

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FXUS61 KBTV 210540
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
140 AM EDT TUE OCT 21 2014

.SYNOPSIS...
LOW PRESSURE WILL SLOWLY MOVE FROM THE GREAT LAKES TONIGHT TO
SOUTH OF LONG ISLAND BY LATE TUESDAY AND THEN REMAIN NEARLY
STATIONARY FOR THE REST OF THE WEEK. AS A RESULT, THE REST OF THE
WEEK WILL BE RAINY AND COOL.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
AS OF 116 AM EDT TUESDAY...OVERALL FORECAST IN GOOD SHAPE WITH
ONLY ONE MINOR TWEAK. SOUTHWESTERLY FLOW IN THE LOW AND MID LEVELS
IS CAUSING THE RAIN SHOWERS OVER WESTERN AND CENTRAL NEW YORK TO
MOVE MORE NORTHEAST. HAVE ADJUSTED OUR PRECIPITATION GRIDS TO
ACCOUNT FOR THIS CHANGE AND INCREASED THE AREAL COVERAGE A BIT OF
THE SHOWERS MOVING IN.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 335 PM EDT MONDAY...THE ACTION REALLY GETS CRANKING FOR
LATER TUESDAY AND WEDNESDAY AS THE UPPER TROF OFF TO THE WEST WILL
DEEPEN/INTENSIFY AND ULTIMATELY CUT-OFF DOWN OVER THE MID-ATLANTIC
TUESDAY NIGHT/WEDNESDAY MORNING. THE ASSOCIATED SURFACE LOW WILL
SET UP SHOP JUST SOUTH OF LONG ISLAND. AND AS WE KNOW, CUT-OFFS
ARE "CUT-OFF" FROM THE MAIN FLOW, SO THAT MEANS THEY DON`T MOVE
VERY QUICKLY.

12Z GUIDANCE STILL ALL SHOWING THIS SAME SCENARIO, SO CONFIDENCE
IS HIGH THAT WE`VE GOT AN EXTENDED PERIOD OF VERY WET CONDITIONS.
DEEP EASTERLY FLOW WILL BECOME ENTRENCHED AND BRING IN COPIOUS
AMOUNTS OF ATLANTIC MOISTURE -- RESULTING IN A GOOD DEAL OF RAIN
TUESDAY AND ESPECIALLY WEDNESDAY (AND BEYOND).

TUESDAY WILL BE A TRANSITION DAY AS THE TROUGH SHARPENS UP. THE
BULK OF THE PRECIPITATION WILL SLIDE JUST TO OUR SOUTH AND WEST.
AS THE TROUGH EVOLVES INTO A CUT-OFF LOW AND AN ASSOCIATED SURFACE
LOW DEVELOPS SOUTH OF LONG ISLAND, THINGS WILL GET MORE
INTERESTING.

EASTERLY FLOW WILL DEVELOP LATE TUESDAY AND STRENGTHEN TUESDAY
NIGHT AND WEDNESDAY. ULTIMATELY WE`LL BE SEEING 850MB WINDS OUT OF
THE EAST AROUND 30-40KTS AND THIS WILL BRING IN ALL THE ATLANTIC
MOISTURE, RESULTING IN A PERSISTENT RAIN, LIKELY OCCASIONAL
MODERATE TO HEAVY ON WEDNESDAY. IT`S JUST GOING TO BE DOWNRIGHT
MISERABLE (CHILLY AND WET).

TOUGHEST PART OF THE FORECAST IS THE PRECIPITATION AMOUNTS AND
LOCATIONS FOR HEAVIEST AMOUNTS. WITH THE EASTERLY FLOW, STILL FEEL
THE FEELINGS BY PREVIOUS FORECASTERS THAT WE SHOULD SEE AN
ENHANCEMENT ALONG THE EASTERN SLOPES OF THE GREEN MOUNTAINS AND
ADIRONDACKS MAKES SENSE. THERE SHOULD BE SHADOWING BY THE WHITE
MOUNTAINS TO KEEP RAINFALL AMOUNTS LESS ACROSS NORTHEAST VERMONT.

AS THE LOW PRESSURE AT THE SURFACE CONTINUES TO DEVELOP AND DRIFT
SLOWLY EAST, THE VERY LOW LEVEL WINDS WILL START TO TURN NORTHEAST
AND EVENTUALLY NORTH. A NORTHERLY FLOW COMING DOWN THE CHAMPLAIN
VALLEY IS A CONVERGENT FLOW, AND THIS SHOULD HELP TO ENHANCE
THE RAINFALL HERE IN THE VALLEY LATE ON WEDNESDAY/WEDNESDAY NIGHT.

ALL THE CLOUDS AND RAIN MEAN THAT TEMPERATURES WILL NOT BE
CHANGING MUCH FROM DAY TO NIGHT. GUIDANCE BLENDS STILL SEEM TO BE
A LITTLE WARM DURING THE DAY AND COOL AT NIGHT, SO TRIED MY BEST
TO MAKE THE DIURNAL DIFFERENCE SMALLER. EVEN SO, I THINK MY FINAL
NUMBERS ARE STILL A LITTLE WARM DURING THE DAY AND COOL AT NIGHT.
BOTTOM LINE, 40S AT NIGHT AND SOME 50S DURING THE DAY (IF WE ARE
LUCKY).

OH YEAH, FOR THE WINTER WEATHER FANS OUT THERE -- SORRY, IT`S
LOOKING JUST WET, NOT WHITE. FREEZING LEVELS WILL BE UP AROUND &
OVER 6,000FT. BESIDES, EVEN IF IT DID SNOW, IT`S STILL EARLY IN
THE SEASON AND WOULD LIKELY NOT HANG AROUND THAT LONG -- SO IT
WOULD JUST BE WASTED.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 308 PM EDT MONDAY...LARGE UPPER LOW WILL BEGIN TO PULL
SLOWLY NORTHEAST ALONG THE NEW ENGLAND COAST DURING THURSDAY INTO
THURSDAY NIGHT BEFORE EXITING INTO THE GULF OF MAINE AND MARITIMES
BY FRIDAY INTO FRIDAY EVENING. DEFORMATIONAL FORCING CONTINUES TO
BE QUITE IMPRESSIVE...ESPECIALLY ACROSS THE NORTHERN HALF OF THE
FORECAST AREA WHERE MODERATE MID LEVEL EAST TO NORTHEAST FLOW WILL BE
UNDERCUT BY LOW LEVEL NORTHERLIES. THIS VEERING/WARM THERMAL
ADVECTIVE PROFILE OFTEN FAVORS MODERATE TO LOCALLY HEAVIER PRECIPITATION
ACROSS THE NRN MTNS AND NRN CHAMPLAIN VALLEY WHERE I`LL MAINTAIN
HIGH POPS AND HEAVIEST QPF.

STEADIER PRECIPITATION/RAINFALL THEN SLOWLY TAPERS TO SCATTERED SHOWERS
BY FRIDAY NIGHT INTO SATURDAY AS DEFORMATION WEAKENS AND LIFTS OUT.
HOWEVER...WITH CONTINUED MOIST NORTHWESTERLY FLOW AND THE PASSAGE OF
ADDITIONAL TAIL END SHORTWAVE ENERGY IT WON`T COMPLETELY DRY OUT UNTIL
SUNDAY INTO MONDAY WHEN HIGH PRESSURE ACROSS THE MIDWEST/GREAT LAKES
FINALLY MAKES SOME INROADS EASTWARD. CONTINUED PRIOR TRENDS IN REGARD
TO TEMPS BY UNDERCUTTING MOS HIGHS AND NARROWING MEAN DIURNAL RANGES
DURING THU/FRI TIME FRAME WITH THE CLOUDS/PRECIPITATION/NORTHERLY FLOW...
GENERALLY OFFERING A RATHER HIGH DEGREE OF HOMOGENEITY ACROSS THE ENTIRE
REGION...INCLUDING THE HIGHER TERRAIN. VALUES FOR THE MOST PART SHOULD
RANGE THROUGH THE 40S TO LOWER 50S IN MOST LOCALES THROUGHOUT THIS
PERIOD. THEREAFTER...READINGS MODERATE SLIGHTLY AS THERMAL ADVECTIVE
PROCESSES WEAKEN AND PROGS OF AT LEAST SOME PARTIAL SUN GRADUALLY
INCREASE...ESP BY NEXT SUNDAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...CURRENT VFR CONDITIONS WILL SLOWLY
DETERIORATE OVER THE NEXT 24 HOURS AS LOW PRESSURE OVER THE
EASTERN GREAT LAKES MOVES OFF THE MID-ATLANTIC COAST THIS EVENING.
SHOWERS WILL SPREAD NORTHWARD OVERNIGHT WITH RAIN EXPECTED ACROSS
THE REGION BY MID-DAY...THOUGH NOT LOOKING AT ANY REAL RESTRICTIONS
IN VSBY PER UPSTREAM OBS. CIGS ARE ANOTHER STORY THOUGH.
KSLK/KRUT/KMPV WILL GENERALLY LOWER TO ONLY MVFR THROUGH THE
DAYLIGHT HOURS...THEN POSSIBLY DOWN TO IFR AFTER 00Z. JUST NW OF
KMSS CIGS ARE IFR ON NORTHEAST FLOW...AND THESE LOWER CEILINGS
SHOULD SHIFT INTO THE ST. LAWRENCE VALLEY FROM 08-10Z AND REMAIN
THERE THROUGH THE TAF PERIOD. FOR KPBG/KBTV...WHEN WINDS SHIFT TO
THE N-NE FEEL IFR CIGS NORTH OF THE BORDER WILL DRAIN DOWN THE
CHAMPLAIN VALLEY...LIKELY MID-MORNING FOR KPBG AND TOWARDS THE
EVENING FOR KBTV. WINDS WILL GENERALLY BY LIGHT FROM 5-10KTS AND
VARIABLE IN DIRECTION FROM SITE TO SITE. EXCEPTION WILL BE KMSS
WHERE NE WINDS WILL INCREASE TO A STEADY 10-15KTS THROUGH THE DAY.

OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...

06Z WED - 12Z FRI...PERIODS OF RAIN WITH PREVAILING MVFR/IFR
CONDITIONS AS LOW PRESSURE LIFTS SLOWLY NORTHEAST ALONG THE NEW
ENGLAND COAST.

12Z FRI - 00Z SUN...SLOWLY IMPROVING CONDITIONS AS LOW PRESSURE MOVES
AWAY TO THE NORTHEAST AND COVERAGE OF RAIN DIMINISHES OVER TIME.
SOME LINGERING IFR/MVFR LIKELY EARLY IN THE PERIOD...TRENDING TO
MAINLY VFR AFTER 12Z SATURDAY.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.

&&

$$
SYNOPSIS...NASH
NEAR TERM...EVENSON
SHORT TERM...NASH
LONG TERM...JMG
AVIATION...LAHIFF







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