Area Forecast Discussion
Issued by NWS Burlington, VT

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000
FXUS61 KBTV 011423
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
1023 AM EDT MON SEP 1 2014

.SYNOPSIS...
HIGH PRESSURE WILL BRIEFLY BUILD ACROSS THE NORTH COUNTRY
TODAY...LABOR DAY...BRINGING VERY WARM AND HUMID CONDITIONS WITH
AFTERNOON HIGHS IN THE LOWER TO MID 80S. A MODERATELY STRONG COLD
FRONT WILL APPROACH FROM THE WEST ON TUESDAY...RESULTING IN
SCATTERED SHOWERS AND THUNDERSTORMS...ESPECIALLY DURING THE
AFTERNOON AND EARLY EVENING HOURS. A FEW STRONGER THUNDERSTORMS
ARE POSSIBLE...MAINLY DURING THE AFTERNOON. THE COLD FRONT WILL USHER
IN DRIER AND SLIGHTLY MORE SEASONABLE AIR MASS AS HIGH PRESSURE
SETTLES OVER THE NORTH COUNTRY FOR WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 1023 AM EDT MONDAY...MINOR UPDATE AS OF 1000 AM TO INTRODUCE
A LOWER/ISOLD CHC FOR A FEW SHOWERS MAINLY ALONG OUR INTL BORDER
AREAS FROM CLINTON COUNTY, NY EASTWARD THROUGH EARLY AFTERNOON AS
TAIL END VORTICITY RIBBON SKIRTS ACROSS THIS AREA. CASE IN POINT A
BRIEF SHOWER AT KEFK IN THE PAST HOUR. MAJORITY OF THE AREA...AND
THE DAY IN GENERAL SHOULD BE DRY HOWEVER AS NARROW SHORTWAVE
RIDGING AT 500 MB MOVES INTO THE AREA. BLENDED 18Z 925 MB TEMPS
SUPPORTING CURRENT FORECAST HIGHS FROM 75 TO 80 IN THE MTNS...AND
80-85 IN THE VALLEYS ALONG WITH PARTLY SUNNY SKIES. HAVE A GREAT
DAY. PRIOR DISCUSSION FOLLOWS...

PRIOR DISCUSSION...
COMPACT SHORTWAVE TROUGH AND ASSOCIATED MID-LEVEL VORTICITY MAX
CENTERED NEAR SHERBROOKE QUEBEC AT 1040Z WILL CONTINUE TO SLIDE
SLOWLY EWD ALONG/JUST NORTH OF THE INTL BORDER THROUGH THE
REMAINDER OF THIS MORNING. ASSOCIATED FORCING HAS GENERALLY
SHIFTED EAST OF OUR LONGITUDE AT THIS POINT...SO NOT EXPECTING ANY
ADDITIONAL SHOWERS TODAY. SOME BREAKS ARE DEVELOPING IN THE
OVERCAST...AND THAT TREND SHOULD CONTINUE LEADING TO PARTLY SUNNY
CONDITIONS FOR THE BALANCE OF THE DAY. VERY HUMID AIR MASS DID
LEAD TO SOME PATCHY FOG DURING THE PRE-DAWN HOURS...AND THAT FOG
WILL GENERALLY DISSIPATE BY 12-1230Z.

THE UPPER LOW ISN/T ASSOCIATED WITH ANY SURFACE FEATURES OF NOTE.
THUS...THE RELATIVELY HUMID AIR MASS IN PLACE WITH DEW POINTS IN
THE MID-UPR 60S AREA WIDE WILL REMAIN. 700MB SHORTWAVE RIDGING
BUILDS IN TODAY FROM THE WEST IN THE WAKE OF AFOREMENTIONED AND
EXITING SHORTWAVE TROUGH. COMBINED WITH 850MB TEMPS +15C TO
+16C...WILL FEEL LIKE MID-SUMMER CONDITIONS FOR THIS LABOR DAY.
TRENDED TOWARD WARMER NAM-MOS GUIDANCE WITH ANTICIPATED AFTERNOON
HIGHS IN THE LOW-MID 80S FOR MOST SECTIONS. WINDS WILL BE
RELATIVELY LIGHT WITH WEAK P-GRADIENT IN PLACE...GENERALLY S-SW
5-8 MPH.

FOR TONIGHT...WILL BE WATCHING EASTWARD PROGRESS OF COLD FRONT
ACROSS THE GREAT LAKES INTO SERN ONTARIO AFTER 06Z. SHOULD BE
GENERALLY TRANQUIL FOR OUR AREA...ALBEIT MUGGY WITH DEW POINTS IN THE
MID 60S. SHOULD SEE SOME DEVELOPING S-SW WINDS OVERNIGHT AS GRADIENT
FLOW STARTS TO INCREASE IN ADVANCE OF APPROACHING COLD FRONT.
SHELTERED SPOTS EAST OF THE GREEN MTNS SHOULD REMAIN NEAR CALM...AND
THIS WILL LEAD TO PATCHY FOG FORMATION IN THE FAVORED VALLEYS EAST
OF THE GREENS. INCREASING MID-UPR CLOUDS EXPECTED FROM WEST TO EAST
ACROSS NRN NY INTO THE CHAMPLAIN VALLEY OVERNIGHT. BTV-4KM AND
BTV-12KM WRF RUNS SUGGEST ISOLATED SHOWERS POSSIBLE TOWARD DAYBREAK
CHAMPLAIN VLY WWD...AND WILL INCLUDE 20-30 POPS TO COVER THIS PROSPECT
FOR THE PRE-DAWN HRS. OVERNIGHT LOWS MAINLY LOW-MID 60S.

&&

.SHORT TERM /11 PM THIS EVENING THROUGH WEDNESDAY/...
AS OF 334 AM EDT MONDAY...TUESDAY LOOKS POTENTIALLY ACTIVE AS COLD
FRONT APPROACHING FROM THE WEST INTERACTS WITH PREVAILING
WARM/HUMID AIR MASS (UPR 60S DEW POINTS). 850MB TEMPS PROGGED AT +17 TO
+18C BY 00Z GFS AND NAM...THOUGH MODELS NOW SHOW A BIT MORE MID-
UPPER LEVEL CLOUDINESS IN STRENGTHENING SWLY FLOW AHEAD OF THE
FRONT. THIS MAY HOLD BACK INSTABILITY A BIT...THOUGH WE SHOULD
STILL SEE VALLEY HIGHS IN THE LOW TO MID 80S (WARMEST ACROSS THE
CHAMPLAIN AND CT RIVER VALLEYS). INSTABILITY IS A BIT LESS THAN
PREVIOUSLY INDICATED...WITH SBCAPE LIKELY 500-1000 J/KG PER
GFS/NAM BETWEEN 18-21Z TUESDAY. DEEP-LAYER SHEAR STILL LOOKS
MODERATELY STRONG...WITH SFC-6KM BULK SHEAR VALUES AROUND 40 KTS
EXPECTED. GIVEN STRONG FORCING/CONVERGENCE ALONG APPROACHING
FRONT...ANTICIPATE DEVELOPMENT OF SCATTERED SHOWERS AND
THUNDERSTORMS...WITH ACTIVITY STARTING IN NRN NY BETWEEN 16-18Z
BEFORE PROGRESSING EWD ACROSS VT 18-00Z. NOT SURE ABOUT SEVERE
THREAT GIVEN MARGINAL CAPE AND WEAK MID-LEVEL LAPSE RATES ONLY
AROUND 6C/KM. THAT SAID...WILL MENTION GUSTY WINDS AND SMALL HAIL
IN THE MORNING HAZARDOUS WEATHER OUTLOOK...ALONG WITH BRIEF HEAVY
RAINFALL GIVEN PW VALUES 1.80 TO 2.00".

COLD FRONT SHIFTS EASTWARD THROUGH VT 00-03Z WEDNESDAY WITH GRADUAL
CLEARING FROM WEST TO EAST TUESDAY NIGHT ALONG WITH POST-FRONTAL
WESTERLY WIND SHIFT. WILL CARRY SOME LOW POPS THRU
MIDNIGHT...ESPECIALLY ACROSS CENTRAL AND ERN VT BEFORE ACTIVITY
EXITS TO THE EAST. WITH LOSS OF DAYTIME INSTABILITY...THUNDER THREAT
SHOULD DECREASE RAPIDLY AFTER 00-01Z. GRADIENT WINDS AND MODEST CAA
LIKELY LIMIT FOG FORMATION TUESDAY NIGHT TO THE MOST FAVORED
LOCATIONS. HIGH PRESSURE BUILDS INTO THE NORTHEASTERN CONUS
WEDNESDAY AND SHOULD SET UP A NICE DAY ACROSS THE NORTH COUNTRY.
VARIABLE MORNING CLOUDINESS WILL GIVE WAY TO PARTLY TO MOSTLY SUNNY
CONDITIONS DURING THE AFTN WITH INCREASING SUBSIDENCE AND DRY AIR
ADVECTION. SHOULD SEE 2-M DEW POINTS FALL INTO THE UPPER 50S. HIGH
TEMPERATURES WILL BE SEVERAL DEGREES COOLER AS WELL...GENERALLY
MID-UPR 70S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 334 AM EDT MONDAY...DRY WESTERLY FLOW WILL PERSIST OVER THE AREA
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THUS NO PRECIPITATION IS
EXPECTED. FLOW ALOFT BACKS TO THE SOUTHWEST ON FRIDAY AS AN UPPER
LEVEL TROUGH MOVES TOWARD THE REGION. A COLD FRONT ASSOCIATED WITH
THE UPPER TROUGH WILL MOVE INTO THE REGION LATE IN THE DAY AND
BRING A SMALL CHANCE OF SHOWERS TO THE AREA FRIDAY
AFTERNOON...ESPECIALLY OVER NORTHERN NEW YORK. THE UPPER TROUGH
AND COLD FRONT GRADUALLY MOVE ACROSS THE AREA FRIDAY NIGHT AND
SATURDAY FOR A CHANCE OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS.
GOING FORECAST HAS THIS COVERED WELL AND WILL CONTINUE THIS IDEA.
SYSTEM EXITS THE AREA SATURDAY NIGHT A RETURN TO DRIER WEATHER ON
SUNDAY. WITH RESPECT TO TEMPERATURES...LOOK FOR A WARMING TREND
THURSDAY AND FRIDAY WITH HIGHS A FEW DEGREES ABOVE NORMAL BEFORE
DROPPING A FEW DEGREES BELOW NORMAL SATURDAY AND SUNDAY.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
THROUGH 12Z TUESDAY...PLENTY OF LOW LEVEL MOISTURE WILL LINGER OVER
THE AREA THROUGH ABOUT 15Z. AS A RESULT...MOST LOCATIONS WILL
EXPERIENCE MVFR TO IFR CEILINGS BUT PERIODS OF LIFR/VLIFR CEILINGS
WILL ALSO EXIST. FOG WILL ALSO PERSIST AT MOST LOCATIONS THROUGH
15Z WITH MVFR AND IFR VISIBILITIES EXPECTED...BUT A FEW PERIODS OF
LIFR AND VLIFR VISIBILITIES. AFTER 15Z...VFR CONDITIONS ARE
EXPECTED THROUGH THE PERIOD WITH LOW CLOUDS AND FOG RETURNING TO
KMPV AND KSLK AFTER 06Z. WINDS WILL GENERALLY BE UNDER 10 KNOTS
THROUGH THE PERIOD.

OUTLOOK 12Z TUESDAY THROUGH FRIDAY...

12Z TUESDAY ONWARD...MAINLY VFR THOUGH MVFR/BRIEF IFR IN SCATTERED
SHOWERS AND THUNDERSTORMS THAT WILL BE MOST NUMEROUS LATE TUESDAY
AFTERNOON AND NIGHT. VFR CONDITIONS EXPECTED WEDNESDAY THROUGH
FRIDAY AS A RIDGE OF HIGH PRESSURE WILL BE OVER THE REGION.

&&

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

&&

$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/JMG
SHORT TERM...BANACOS
LONG TERM...EVENSON
AVIATION...EVENSON/SLW






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