Area Forecast Discussion
Issued by NWS Burlington, VT

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000
FXUS61 KBTV 011131
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
731 AM EDT SAT NOV 1 2014

.SYNOPSIS...
A DEVELOPING DEEP TROUGH OF LOW PRESSURE ACROSS THE
EASTERN UNITED STATES WILL PRODUCE RAIN AND SNOW SHOWERS...ALONG
WITH MUCH COLDER TEMPERATURES THIS WEEKEND. SNOW ACCUMULATIONS WILL
RANGE FROM A DUSTING IN THE VALLEYS TO SEVERAL INCHES IN THE
MOUNTAIN. TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW
NORMAL WITH BRISK NORTH WINDS DEVELOPING TODAY INTO SUNDAY. A
SLOW WARMING TREND IS ANTICIPATED BY EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 712 AM EDT SATURDAY...MINOR UPDATE TO CUT BACK ON TEMPS ACRS
OUR CENTRAL/SOUTHERN CWA TODAY AND MATCH CRNT OBS. THINKING CLOUDS
AND EVENTUALLY PRECIP ARRIVING WL KEEP TEMPS MAINLY IN THE L/M 30S
MTNS TO L/M 40S WARMER VALLEYS. IMPRESSIVE WATER VAPOR LOOP THIS
MORNING WITH POTENT/COMPACT S/W DROPPING SE ALONG THE SC/GA BORDER...AND
DEEP SOUTHERLY FLW WITH EMBEDDED PIECES OF ENERGY ALONG THE
EASTERN SEABOARD. THIS POTENT ENERGY ACRS THE SOUTH...HAS
PRODUCED REPORTS OF SNOW IN ASHVILLE NC WITH LIGHTNING...AND
SEVERAL OTHER LOCATIONS GETTING -SN WITH VIS BTWN 1-3SM IN
NORTHERN GA/SC AND PARTS OF NC. THIS ENERGY AND COLD POCKET ALOFT
WL HELP ENHANCED SFC LOW PRES OFF THE COAST THIS
AFN/EVENING...WITH A GENERAL TRACK TO THE NORTH TWD THE 40/70
BENCHMARK BY SUNDAY. BEST MOISTURE/DYNAMICS WL JUST GLANCE OUR
CENTRAL/EASTERN CWA THIS AFTN/EVENING...WITH SOME LIGHT RAIN AND
SNOW LIKELY. CRNT FCST HAS THIS COVERED WELL WITH NO FURTHER
ADJUSTMENT NEEDED.

THE 1ST SNOW ACCUMULATION OF THE SEASON IS LIKELY FOR THE EASTERN
DACKS INTO THE MOUNTAINS OF VT LATE TODAY INTO TONIGHT...WITH SNOW
ACCUMULATIONS OF A DUSTING TO SEVERAL INCHES POSSIBLE.

FCST CHALLENGE CONTS TO BE COASTAL SYSTEM TODAY INTO SUNDAY AND
POTENTIAL IMPACTS ACRS OUR CWA. GIVEN MAGNITUDE OF SYSTEM WITH 5H/7H
HGHT FIELDS 4 TO 5 STD BLW NORMAL ACRS THE SE CONUS...AND AMOUNT OF
CONVECTION DEVELOPING ACRS THE GULF STREAM...FORECASTER CONFIDENCE
IS BLW AVERAGE.  OVERALL...ALL MODELS (GFS/NAM/GEM/ECMWF) AND
ENSEMBLE MEMBERS ARE IN GOOD AGREEMENT WITH HANDLING MAIN MID/UPPER
LVL SYNOPTIC FEATURES AND ASSOCIATED SFC REFLECTION. 00Z TRENDS HAVE
BEEN FOR A SLIGHT WESTWARD SHIFT IN 5H/7H CIRCULATION
TRACK...RESULTING IN SLIGHTLY MORE QPF ACRS OUR CENTRAL/EASTERN
SECTIONS. BOTH GFS/NAM SHOW QPF AMOUNTS BTWN 0.15 AND 0.55" ALONG
AND EAST OF THE CPV...WITH SOME FALLING IN THE FORM OF
SNOW...ESPECIALLY SATURDAY NIGHT.

AS POTENT 5H VORT DIVES INTO THE SE CONUS...A FULL LATITUDE TROF WL
DEVELOP ALONG THE EASTERN SEABOARD THIS MORNING....WITH ELONGATED
SFC LOW PRES FROM THE 40/70 BENCHMARK TO 100 MILES EAST OF CAPE
HATTERAS. THIS SFC LOW PRES WL CONSOLIDATE INTO A SINGLE CENTER BY
12Z SUNDAY...NEAR THE 40/70 BENCHMARK...AS INTERACTION WITH POTENT
5H VORT OCCURS. IT SHOULD BE NOTED THIS TRACK TYPICALLY PLACES
HEAVIEST QPF TO OUR EAST...WITH OUR CWA ON WESTERN FRINGE. RAPID SFC
DEVELOPMENT WL OCCUR AND SYSTEM WL QUICKLY BECOME VERTICALLY STACKED
AS IT TRACKS INTO THE GULF OF MAINE. THIS TIGHTLY WRAPPED SYSTEM WL
LEAVE A SHARP WEST TO EAST PRECIP GRADIENT...WL HEAVIEST QPF
EXPECTED ACRS CENTRAL/EASTERN NEW ENGLAND...JUST EAST OF OUR CWA ON
SUNDAY.

MEANWHILE...OUR QPF WL ACTUAL OCCUR THIS AFTN/TONIGHT ASSOCIATED
WITH INITIAL 5H VORT/WEAK MID WAA...AND DEPARTING RRQ OF 25H JET
ACRS EASTERN CANADA. IR SATL ALREADY SHOWING COOLING OF THE CLOUD
TOPS ACRS SNE/WESTERN ATLANTIC THIS MORNING. AS MID/UPPER LVL FLW
BECOMES SOUTHERLY FROM DIGGING TROF ACRS THE SE CONUS...THIS
MOISTURE WL ADVECT INTO OUR CENTRAL/EASTERN CWA THIS AFTN/EVENING.
HOWEVER...AT THE SAME TIME DEVELOPING NORTHERLY FLW FROM THE SFC
THRU 925MB WL BE ADVECTING LLVL DRY INTO THE REGION...SETTING UP THE
BATTLE BTWN DRY AIR TO THE NORTH AND MOISTURE TO THE SOUTH. THINKING
SOME VIRGA WL BE POSSIBLE...AS PRECIP DEVELOPS FROM SOUTH TO NORTH
TODAY ACRS OUR CWA. THINKING LIGHT RAIN WL START ACRS RUTLAND/WINDSOR
COUNTIES BTWN 15-18Z...SPREAD INTO CENTRAL VT/EASTERN DACKS BTWN
18-21Z...AND INTO THE NORTHERN SECTIONS AFT 21Z TODAY. INITIALLY
THERMAL PROFILES ARE WARM WITH BL TEMPS NEAR 4C...SUPPORTING RAIN
IN THE VALLEYS...WITH SNOW LEVELS NEAR 2000 FEET FOR
CENTRAL/NORTHERN MTNS AND ABOVE 2500 FT FOR SOUTHERN GREEN MTNS.
DEVELOPING NORTH TO NORTHEAST FLW WL CONT TO COOL THE COLUMN
FURTHER...WITH SNOW LEVELS DROPPING TO 1000 FEET BY 21Z FOR
NORTHERN/CENTRAL MTNS AND 1500 FT FOR MTNS OF RUTLAND/WINDSOR
COUNTIES. BY 00Z THIS EVENING...SOUNDINGS SHOW LEVELS DROPPING
CLOSE TO THE VALLEY FLOOR...EVEN INTO THE CPV/CT RIVER
VALLEY...BUT AS THIS OCCURS BETTER DYNAMICS/MOISTURE IS
WEAKENING...ESPECIALLY BY 06Z. VERY DIFFICULT TO DETERMINE AMOUNT
OF QPF AND HOW MUCH WL FALL IN THE FORM OF SNOW...ESPECIALLY GIVEN
THE WEST TO EAST GRADIENT ACRS OUR CWA. ITS BEEN NOTED WE DON`T
HAVE THE STRONG UVVS TO COOL THE COLUMN QUICKLY WITH HEAVIER
PRECIP RATES...SO THE CHANGE ACRS THE LOWER ELEVATIONS WL OCCUR
SLOWLY AND PROBABLY RESULT IN MORE OF A MIX OF RAIN AND WET SNOW
FLAKES.

FOR THE SLV/WESTERN DACKS...NOT EXPECTING MUCH MAYBE A DUSTING OF
SNOW POSSIBLE BY SUNDAY MORNING. FOR THE CPV/EASTERN
DACKS...THINKING A DUSTING TO MAYBE AN INCH ON GRASSY SURFACES AWAY
FROM THE LAKE. MUCH MORE DIFFICULT TO DETERMINE ACCUMULATIONS OF
CENTRAL/NORTHERN AND EASTERN VT...BUT THINKING DUSTING TO 2 INCHES
WITH AMOUNTS ABOVE 2000 FEET IN THE 2 TO 4 INCH RANGE BY 12Z
SUNDAY....GIVEN INCREASED FLUFF FACTOR AT NIGHT ASSOCIATED WITH
COOLING THERMAL PROFILES. CIPS 15 TOP ANALOGS SUPPORTS THIS THINKING
WITH A GENERAL 1 TO 4 INCH SNOWFALL FOR THE MTNS OF CENTRAL/NORTHERN
VT.

AS SFC LOW PRES DEEPENS IN THE GULF OF MAINE ON SUNDAY...GRADIENT
INCREASES ACRS OUR CWA...WITH 925MB TO 850MB WINDS OF 35 TO 45 KNOTS
ACRS OUR CENTRAL/EASTERN SECTIONS. THIS WL RESULT IN GUSTY SFC
WINDS...ESPECIALLY IN THE NORTH TO SOUTH ALIGNED CPV AND PARTS OF
THE CT RIVER VALLEY OF 25 TO 35 MPH LIKELY...LATE TONIGHT INTO
SUNDAY. EXPECT MID WINTER CONDITIONS FOR THE MTN SUMMITS WITH TEMPS
ONLY IN THE TEENS AND WINDS GUSTING 40 TO 50 MPH...ESPECIALLY ON
SUNDAY MORNING.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
AS OF 400 AM EDT SATURDAY...FOR SUNDAY...NORTHERLY WINDS SLOWLY
TURN TO THE NORTHWEST WITH 85H FLW OF 35 TO 45 KNOTS. THIS
FAVORABLE UPSLOPE DIRECTION AND SPEED WL PRODUCE SOME ADDITIONAL
LIGHT PRECIP ON SUNDAY MORNING...BUT AS FLW BECOMES
FAVORABLE...LLVLS ARE QUICKLY DRYING. ALSO...HAVE NOTED WE LOSE RH
IN THE FAVORABLE SNOW GROWTH REGION BY 15Z SUNDAY. WL USE CLIMO
ADJUST POP TOOL AND TRY TO SHOW SOME ENHANCED PRECIP ACRS THE
NORTHERN GREENS FROM JAY PEAK TO MT MANSFIELD...BEFORE MUCH DRIER
AIR MIXES TO THE SFC ON SUNDAY AFTN. PROGGED 85H TEMPS ARE COLD
WITH VALUES AROUND -8C...SUPPORTING HIGHS ONLY IN THE U10S TO M20S
MTNS TO M/U 30S WARMER VALLEYS...MAYBE NEAR 40F AT BTV. NAM/ECWMF
AND GFS SHOW DEEP LAYER DRY AIR DEVELOPING ACRS OUR CWA ON NW FLW
ALOFT FOR SUNDAY NIGHT INTO MONDAY. THIS WL RESULT IN CLRING
SKIES...BUT 85H WINDS ARE STILL BTWN 30 AND 40 KNOTS WITH TIGHT
GRADIENT RELAXING TWD MORNING. HAVE NOTED MAV/MET AT SLK DOWN TO
9F FOR A LOW AND NEAR 20F AT BTV...BUT THINKING THIS IS TOO COLD
GIVEN WINDS/MIXING...SO WL MENTION LOWS IN THE M/U TEENS MTN
VALLEYS AND MID/UPPER 20S WARMER VALLEYS...GOOD TEMPS FOR MAKING
SNOW...ESPECIALLY WITH THE DROPPING RH VALUES. MONDAY WL BE DRY
WITH TEMPS WARMING INTO THE 30S MTNS AND 40S VALLEYS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 440 AM EDT SATURDAY...LATEST MODEL GUIDANCE FAIRLY
CONSISTENT WITH PREVIOUS RUNS. LOOKS RATHER UNSETTLED FOR MUCH OF
THE PERIOD.

RIDGE AXIS MOVES ACROSS THE AREA MONDAY NIGHT ALLOWING FOR CLEAR
TO PARTLY CLOUDY SKIES...LIGHT WINDS AND SEASONABLY CHILLY TEMPS
WITH LOWS IN THE 20S...WITH LOWEST READINGS IN THE NORTHEAST
KINGDOM AND ADIRONDACKS. AS RIDGE SLIDES EAST OF THE AREA
TUESDAY...DEEP SOUTHWEST FLOW WILL DEVELOP ACROSS THE REGION
ALLOWING FOR WARM FRONT TO LIFT NORTHEAST ACROSS THE AREA. THE
RESULT WILL BE CLOUDS AND A CHANCE OF SHOWERS...WITH BEST CHANCE
FOR PRECIP BEING ACROSS NORTHERN NEW YORK. DESPITE THE
CLOUDS...WARMING AT 850 MB (+6 TO +8C) WILL ALLOW FOR TEMPS TO
REBOUND INTO THE LOWER TO MID 50S.

CHANCE OF SHOWERS CONTINUES TUESDAY NIGHT AS SHORTWAVE TROUGH
MOVES EAST FROM THE GREAT LAKES ALONG WITH WEAK SURFACE COLD
FRONT. THIS FRONT WEAKENS FURTHER WHILE PUSHING SLOWLY EAST OF THE
AREA WEDNESDAY. HAVE CONTINUED WITH A LOW CHANCE OF SHOWERS
WEDNESDAY/WEDNESDAY NIGHT...BUT EXPECT MUCH OF THE TIME TO BE DRY
AS WEAK RIDGING DEVELOPS IN ADVANCE OF OUR NEXT WEATHER SYSTEM.
DESPITE COOLER 850 MB TEMPS WEDNESDAY...HIGHS WILL BE SIMILAR TO
TUESDAY DUE DRIER CONDITIONS AND SOME AFTERNOON SUN.

CHANCES FOR PRECIPITATION THEN INCREASE ONCE AGAIN THURSDAY AS
POTENT SHORTWAVE DIVES SOUTHEAST INTO THE GREAT LAKES/OHIO VALLEY.
UPPER FLOW TAKES ON NEGATIVE TILT LATER THURSDAY INTO THURSDAY
NIGHT...WITH ECMWF SUGGESTING SYSTEM MAY BECOME CUTOFF.
PRECIPITATION CHANCES REMAIN RATHER HIGH INTO FRIDAY AS THE LOW
PRESSURE SYSTEM MOVES SLOWLY EAST OF THE AREA...WITH DEEP
NORTHWEST FLOW ASSURING A CONTINUATION OF CLOUDS AND SCATTERED
SHOWERS. IT WILL BE COOLER WITH HIGHS MOSTLY IN THE 40S...EXCEPT
30S IN THE MOUNTAINS WHERE SNOW SHOWERS ARE POSSIBLE.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 12Z SUNDAY...VFR CONDITIONS EXPECTED THIS MORNING...THEN
CEILINGS WILL LOWER INTO THE MVFR CATEGORY. EXPECT SOME LIGHT RAIN
SHOWERS OR RAIN/SNOW MIX TO DEVELOP AFTER 16Z. NO OBSTRUCTION TO
VISIBILITY IS EXPECTED UNTIL AFTER 23Z WHEN VSBYS WILL LOWER TO
3-5SM WITH PSBL IFR AT MPV IN LIGHT SNOW. WINDS WILL BE MOSTLY
NORTH AND INCREASE TO 10 TO 20 KTS TODAY.

OUTLOOK 12Z SUNDAY THROUGH WEDNESDAY...
12Z SUN-00Z MON: MVFR CIGS WITH LINGERING SNOW FLURRIES EARLY
SUNDAY...THEN VFR BY AFTERNOON. NORTHERLY SURFACE WINDS WILL BE
GUSTING IN THE 25-35KT RANGE ON SUNDAY.

00Z MON-12Z TUE: VFR

12Z TUE ONWARD: MVFR CONDITIONS DEVELOPING WITH SCATTERED SHOWERS
AND LOWERING CEILINGS.

&&

.EQUIPMENT...
AS OF 400 AM EDT SATURDAY...THE KCXX-88D DOPPLER RADAR IN
COLCHESTER VERMONT IS OUT OF SERVICE AT THIS TIME. ELECTRONICS
TECHNICIANS HAVE FOUND A PROBLEM WITH HIGH VOLTAGE ARCING AND
PARTS HAVE BEEN ORDER AND SHOULD ARRIVE TODAY. OWING TO THE
COMPLEX NATURE OF THE PROBLEM...IT APPEARS THE EARLIEST RETURN TO
SERVICE WILL BE SOMETIME THIS AFTERNOON OR EVENING.

&&

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

&&

$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
EQUIPMENT...WFO BTV



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