FXUS61 KBTV 031521
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1021 AM EST THU DEC 3 2009
.SYNOPSIS...
LOW PRESSURE OVER THE EASTERN GREAT LAKES WILL MOVE THROUGH THE
SAINT LAWRENCE VALLEY THIS MORNING...AND INTO MAINE THIS AFTERNOON.
RAIN WILL TAPER TO SHOWERS AND WINDS WILL BE GUSTY AT TIMES...ALONG
WITH MILD TEMPERATURES. IT WILL TURN COOLER TONIGHT AND
FRIDAY...AND THERE WILL BE A CHANCE OF SNOW OR RAIN
SHOWERS...ESPECIALLY OVER THE HIGHER TERRAIN. HIGH PRESSURE WILL
BRING MAINLY DRY AND SEASONABLY COOL TEMPERATURES OVER THE
WEEKEND...WHILE LOW PRESSURE PASSES SOUTH OF NEW ENGLAND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1020 AM EST THURSDAY...WL UPDATE FCST TO TWEAK POPS PER LATEST
RADAR TRENDS AND ADJUST TEMPS IN A FEW LOCATIONS. CRNT RADAR SHOWS
HEAVIEST RAINFALL DEPARTING THE CPV AND RACING INTO NORTHERN VT
ATTM. OBS AND RADAR ESTIMATES SHOW BTWN 1.00" AND 1.50" OF QPF HAS
FALLEN ACRS CENTRAL/SOUTHERN VT WITH 0.50" TO 0.75" ACRS CPV AND
NORTHERN VT...AND BTWN 0.25" AND 0.75" ACRS NORTHERN NY/SLV.
HYDROVIEW SHOWS SOME INCREASE IN RIVER LEVELS...ESPECIALLY AT
CENTER RUTLAND...BUT NO FLOODING IS ANTICIPATED. OTHERWISE...ONLY
SCATTERED SHOWERS ARE NOTED UPSTREAM ACRS CENTRAL/NORTHERN NY
ATTM...WITH JUST AREAS OF PATCHY DRIZZLE AND FOG ACRS
SOUTHERN/CENTRAL VT. WL TRIM POPS BACK TO CHC ACRS
CENTRAL/NORTHERN VT AND NY FOR THE REST OF TODAY AND JUST MENTION
SCHC POPS FOR SOUTHERN VT. BEST 850-500MB MOISTURE AND UVVS WL BE
NORTH AND EAST OF FA BY 16Z TODAY...ALONG WITH BEST ULVL AND LLVL
JET DYNAMICS. FURTHERMORE...THE THREAT FOR GUSTY SE WINDS ALONG
THE WESTERN SLOPES OF THE GREEN MTNS HAS ENDED. SOUNDINGS SUPPORT
BETTER MIXING THIS AFTN AS DRIER AIR ADVECTS INTO OUR CWA...AND
SHARP PRES RISES OCCUR AFT FROPA. THEREFORE EXPECT SW WINDS OF 10
TO 20 MPH WITH GUSTS BTWN 25 AND 35 MPH POSSIBLE THIS AFTN ACRS
THE CWA. TEMPS WL BE TRICKY...ESPECIALLY WITH SOME CLRING ACRS
EXTREME SOUTHERN VT ZNS. HAVE NOTED NORTH ADAMS IN WESTERN MA TEMP
JUMPED INTO THE L60S AS WINDS TURNED TO THE SW...THEREFORE EXPECT
U50S/L60S FOR RUT/VSF...WITH MID 50S FOR BTV/MPV AND L/M 50S FOR
THE DACKS...WITH ONLY M/U 40S FOR MSS DUE TO MAINLY NE WINDS DOWN
THE SLV. CRNT FCST HAS THIS COVERED PRETTY WELL WITH ONLY A FEW
MINOR ADJUSTMENTS NEEDED. BELOW IS A LIST OF THE RECORD HIGH TEMPS
FOR TODAY ACRS OUR CWA...WHICH MAY COME CLOSE TO BEING
BROKEN...ESPECIALLY AT MPV. BTV 56F SET IN 1982 MSS 65F SET IN
1982 MPV 52F SET IN 1982 1V4 54F SET IN 1932
PREVIOUS FORECAST DISCUSSION...989 MB LOW OVER ERN PORTION OF LAKE ERIE
WILL TRACK NEWRD UP THRU ST LWR VLY THIS MORNING...THEN SHIFT EAST
INTO MAINE THIS PM. WDSPRD LIGHT TO MODERATE RAINFALL ACRS THE
FORECAST AREA ATTM AS STRONG SOUTHERLY FLOW ALLOWING FOR INFLUX OF
DEEP MSTR AND MILD AIR INTO THE RGN. BAND OF STRONG FGEN OVER THE
AREA WILL BE LIFTING NORTH OF THE BORDER BY AROUND 12Z. MID/UPPER
LEVEL DRY SLOT THEN LIFTS NEWRD INTO THE FA THIS
MORNING...RESULTING IN STEADY RAIN TAPERING TO SHWRS. LATEST RADAR
COMPOSITE STILL SHOWS GOOD COVERAGE OF SHWRS OVER PENNSYLVANIA IN
ASSOCIATION WITH VORT MAX...WHICH WILL BE RACING NEWRD ACRS THE
RGN THIS MORNING. EVEN SOME LIGHTNING BEING DETECTED AT TIMES WITH
THIS FEATURE...SO WOULDN'T BE SURPRISED IF THERE WAS A RUMBLE OF
THUNDER THIS MORNING. HAVE CONTD WITH HIGH POPS THRU MIDDAY...THEN
TAPER TO CHC THIS PM WITH DEPARTURE OF THE SHRTWV AND SFC LOW.
RAINFALL TOTALS WITH THIS EVENT EXPECTED TO RANGE FROM .50 TO 1.25
INCHES ACROSS THE AREA. MAX TEMPS TDY WILL RANGE FROM THE 40S IN
ST LWR VLY TO NEAR 60 IN SRN VT.
AS FOR WINDS...LLVL JET MAX MOVG ACRS FORECAST AREA ATTM...BUT
LIMITED MIXING RESULTING IN STRONGEST WINDS ABOVE TEMP INVERSION.
THERE IS POTENTIAL FOR SOME GUSTY WINDS IN ANY SHWRS ASSOCD WITH
SHRTWV PASSAGE THIS MORNING. MORE WDSPRD BREEZY CONDITIONS EXPECTED
TO DEVELOP THIS PM AS BETTER MIXING DEVELOPS WITH LLVL DRYING AND
PRESSURE RISES AFTER FROPA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
AS OF 443 AM EST THURSDAY...SFC LOW PRESSURE MOVES INTO EASTERN
CANADA AND WEAKENS TONIGHT INTO FRIDAY NIGHT...WHILE MEAN UPPER
LEVEL TROUGH REMAINS TO THE WEST OVER THE GRTLKS. EXPECT SOME
LINGERING SHOWERS DURING THIS PERIOD...MAINLY OVER THE HIR TRRN.
PTYPE WILL BE RAIN THIS EVENING...BUT WITH GRADUAL CAA TONIGHT
INTO FRI NITE...EXPECT SCT RAIN SHWRS TO CHANGE TO MAINLY SNOW
SHWRS. CYCLONIC WESTERLY FLOW WILL ALLOW FOR SOME GRTLKS MSTR TO
OVRSPRD FORECAST AREA...RESULTING IN LAKE EFFECT OR OROGRAPHIC
SNOW SHWRS DOWNWIND OF LAKE ONTARIO OVER THE ADRNDKS INTO THE NRN
GREEN MTNS WITH SOME LIGHT SNOW ACCUM PSBL. SEVERAL VORTS IN THE
SW FLOW ALOFT...ALONG WITH SOME LLVL INSTABILITY DURING
FRIDAY...WILL ENHANCE PCPN CHANCES AT TIMES. HIGHEST POPS EAST OF
LAKE ONTARIO OVER THE ADRNDKS AND SRN PORTION OF THE ST LWR
VLY...WHILE LOWEST POPS WILL BE EAST OF THE GREENS WHERE LITTLE IF
ANY PCPN EXPECTED DUE DOWNSLOPING AND DISTANCE FROM MSTR SOURCE.
PTYPE FRI/FRI NITE WILL BE SNOW OVER THE HIR TRRN...BUT STILL MILD
ENOUGH IN THE VLYS DURING FRIDAY SO THAT SNOW OR RAIN SHWRS ARE
PSBL.
ON SATURDAY...HIGH PRESSURE ATTEMPTS TO BUILD INTO RGN. AS LLVL
WESTERLY FLOW DECREASES...THE CHC FOR ANY LAKE ENHANCED SNOW SHWRS
WILL DECREASE AS WELL. WE WILL ALSO HAVE TO WATCH OFFSHORE LOW
PRESSURE SYSTEM...WHICH MOST MODELS INDICATE WILL REMAIN FAR
ENOUGH SOUTH OF THE BENCHMARK SO AS NOT TO HAVE AN EFFECT ON NORTH
COUNTRY WX. TEMPS SATURDAY NEAR SEASONAL LEVELS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 AM EST THURSDAY...EXTENDED PORTION OF THE FORECAST IS
VERY QUIET...ASIDE FROM THE VERY END OF THE PERIOD TOWARDS THE
MIDDLE OF NEXT WEEK. LOW PRESSURE SYSTEM WILL STAY OUTSIDE OF THE
BENCHMARK SATURDAY NIGHT...THEREFORE NOT EXPECTING ANY PRECIP WITH
THIS SYSTEM. SURFACE HIGH PRESSURE WILL REMAIN OVER THE REGION
THROUGH THE MAJORITY OF THE EXTENDED. A WEAK LOW PRESSURE SYSTEM
WILL PASS TO OUR NORTH ON TUESDAY...THEREFORE HAVE INCLUDED CHANCE
FOR SHOWERS ACROSS THE NORTH COUNTRY FOR THAT TIME. ROBUST LOW
PRESSURE SYSTEM TAKES SHAPE TUESDAY NIGHT AND TRACKS TOWARDS THE
NORTHEAST ON WEDNESDAY. THIS LOOKS TO BE BEST CHANCE FOR
PRECIPITATION THROUGH THE EXTENDED...ALTHOUGH IT IS DAY 7 SO
CONFIDENCE IS FAIRLY LOW. TRACK OF THIS LOW WILL DETERMINE WHETHER
IT WILL BE YET ANOTHER RAIN EVENT...OR FINALLY A SNOW EVENT.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THROUGH 12Z FRIDAY...RAIN AND WIND WILL BE THE PRIMARY CONCERNS
THROUGH THE MORNING HOURS...THEN SOME GUSTY WINDS THIS AFTERNOON.
CEILINGS HAVE BEEN DROPPING TO MVFR IN VERY HEAVY RAIN. SOME
PERIODS OF MODERATE TO HEAVY RAIN ARE EXPECTED THIS
MORNING...ESPECIALLY AT RUT. THE RAIN WILL BEGIN TO DIMINISH
AFTER ABOUT 10 AM AND SHOULD BE OVER BY NOON. AT THAT POINT
CEILINGS WILL RAISE TO VFR AT MOST LOCATIONS...THOUGH REMAIN MVFR
AT KSLK AND KMPV THROUGH 00Z FRIDAY. WINDS IN ADVANCE OF THE LOW
PRESSURE CENTER WILL BE GENERALLY S TO SE 10-15KT WITH GUSTS TO
25KT. WINDS BETWEEN 1-2KFT ARE GENERALLY SE AT 40KT... SO SPEED
SHEAR IS A BIT OF AN ISSUE. STRONGEST SFC WINDS ARE EXPECTED
BEFORE SUNRISE AS THIS IS WHEN THE SFC PRESSURE GRADIENT WILL BE
STRONGEST. AS THE LOW PRESSURE CENTER PASSES UP THE ST LAWRENCE
VALLEY WINDS WILL BACK RAPIDLY TO THE SW. THIS WILL OCCUR AROUND
15Z...AND REMAIN GUSTY FROM THE SW THROUGH THE REMAINDER OF THE
PERIOD.
OUTLOOK 12Z FRIDAY THROUGH MONDAY...
12Z FRI THRU 00Z SAT...VFR/MVFR IN SCATTERED SNOW SHOWERS..MAINLY
NRN MTNS/KSLK TERMINAL. 00Z SAT THRU 00Z SUN...VFR/MVFR POSSIBLE
IN LIGHT RAIN AND/OR SNOW...ESP EAST. 00Z SUN THRU 00Z
MON...MAINLY VFR THOUGH W/OCCNL MVFR/IFR IN LAKE SHSN...MAINLY AT
THE KSLK TERMINAL.
&&
.CLIMATE...
BTV REMAINS WITHOUT MEASURABLE SNOWFALL SO FAR THIS SEASON. THE
RECORD LATEST DATE IS WITHIN SIGHT.
FOR BURLINGTON...ON AVERAGE THE FIRST MEASURABLE SNOW HAPPENS
NOVEMBER 6TH. HERE ARE THE 10 LATEST FIRST SNOWS FOR BURLINGTON
GOING BACK TO 1906...ALONG WITH THE SEASONAL TOTAL SNOW THAT
FOLLOWED.
SEASON TOTAL
RANK DATE SNOWFALL (INCHES)
1. 12/7/1937 45.1
2. 12/5/1915 54.4
3. 12/?/2009 XXXX
4. 12/1/1948 40.7
5. 11/30/1918 69.6
11/30/1953 83.6
11/30/1960 51.6
8. 11/28/1913 56.5
9. 11/27/1941 57.7
10. 11/26/1982 80.5
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS/TABER
SHORT TERM...RJS
LONG TERM...NEILES
AVIATION...NEILES
CLIMATE...
