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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 282254
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
654 PM EDT MON JUL 28 2014

.SYNOPSIS...
SURFACE LOW PRESSURE WILL TRACK INTO EASTERN CANADA TONIGHT...WITH
OCCASIONAL RAIN SHOWERS AND EMBEDDED THUNDERSTORMS SLOWLY
DISSIPATING ACROSS OUR REGION OVERNIGHT. TUESDAY WILL BE MAINLY DRY
WITH SLIGHTLY BELOW NORMAL TEMPERATURES. ADDITIONAL SHOWERS WITH AN
ISOLATED THUNDERSTORM WILL BE POSSIBLE BOTH WEDNESDAY AND THURSDAY
AFTERNOONS. TEMPERATURES WILL GENERALLY BE COOLER THAN NORMAL
THROUGH THE PERIOD.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 655 PM EDT MONDAY...MINOR UPDATE TO REMOVE MENTION OF
THUNDERSTORMS ACRS NORTHERN NY/VT AND INCREASE WINDS ACRS THE CPV.
SFC LOW PRES LOCATED NEAR EXETER NH WL CONT TO MOVE QUICKLY NE
INTO EASTERN CANADA OVERNIGHT...WHILE POTENT 5H VORT AND BACKSIDE
DEFORMATION ZN DEVELOPS FROM WESTERN NY INTO NORTHERN VT. THIS
COMBINED WITH FAVORABLE NORTH TO NORTHWEST FLW DOWN THE CPV WL
RESULT IN CONTINUED RAINFALL ACRS THE EASTERN DACKS INTO THE CPV
AND WESTERN SLOPES THRU 06Z TONIGHT. KBTV HAS MEASURED 0.40 LAST
HR ASSOCIATED WITH THIS FEATURE. KCXX VAD SHOWS 925MB WINDS OF 30
KNOTS FROM THE NORTH...HELPING TO ENHANCE THE LLVL CONVERGENCE
ACRS THE CPV. THINKING AN ADDITIONAL 0.25 TO 0.75 WITH LOCALIZED
HIGHER AMOUNTS WL BE POSSIBLE ACRS NORTHERN DACKS INTO THE
CPV/WESTERN SLOPES THRU MIDNIGHT TONIGHT. RAINFALL INTENSITY
SHOULD NOT CAUSE ANY FLOOD RELATED PROBLEMS. MEANWHILE...DEEP
LAYER MOISTURE AND ULVL SUPPORT WL SLOWLY WEAKEN AFT 06Z AND
PRECIP WL BECOME SCATTERED. CONTINUED TO MENTION 100% POPS ACRS
THE NORTHERN CWA WITH CHC/LOW LIKELY SOUTHERN CWA...WITH SCHC FOR
THUNDER THRU EARLY THIS EVENING. STILL NOTING A FEW LIGHTNING
STRIKE ACRS THIS REGION.

JUST LIKE WINTER STORMS A SLIGHT SHIFT IN THE SFC LOW
TRACK...RESULTS IN A WIDE RANGE OF WX. FOR THIS AFTN THE SFC LOW
JUMPED TO CONVECTION THAT DEVELOPED OVER SOUTHERN/CENTRAL NEW
ENGLAND...AND RESULTED IN MUCH LESS INSTABILITY ACRS OUR CWA. A
FURTHER NORTH TRACK WOULD HAVE PLACED OUR CWA IN THE WARM SECTOR
WITH GREATER INSTABILITY. THEREFORE WITH CAPE VALUES ONLY BTWN 500
AND 800 J/KG...AND PLENTY OF CLOUDS AND COOL NORTHERLY WINDS...THE
THREAT FOR SVR STORMS HAS ENDED ACRS OUR CWA. HAVE MENTIONED
OCCASIONAL SHOWERS WITH SCHC FOR STORMS THRU 00Z THIS
EVENING...THEN REMOVED MENTION OF CONVECTION FOR THE OVERNIGHT
HRS. AREAL COVERAGE AND INTENSITY OF PRECIP WL BECOME TRRN DRIVEN
BY 03Z TONIGHT...WITH HEAVIEST PRECIP ACRS THE EASTERN
DACKS...NORTHERN CPV...AND PARTS OF THE NORTHERN GREENS.

THINKING THE THREAT FOR ADDITIONAL FLASH FLOODING WL DECREASE WITH
THE LOSS OF INSTABILITY THIS EVENING...AND WEAKER RAINFALL RATES.
SOUTHERN RUTLAND AND WINDSOR COUNTIES WL NEED TO BE
WATCHED...ESPECIALLY WITH STORM TOTAL PRECIP IN EXCESS OF 3
INCHES. ALL IS COVERED IN CRNT WARNING STATEMENT.

WATER VAPOR SHOWS AN IMPRESSIVE SYSTEM
ACROSS THE NE CONUS WITH WELL DEFINED DRY SLOT...GOOD WARM AIR
CONVEYOR BELT OF DEEP TROPICAL MOISTURE...AND WRAP AROUND COMMA
HEAD. THIS POTENT 5H VORT AND ASSOCIATED MOISTURE WITH LIGHTNING
ACTIVITY WL LIFT ACRS OUR CWA THRU EARLY THIS EVENING...WITH
SHOWERS AND THUNDERSTORMS LIKELY. SOME OF THE STRONGER STORMS
WHERE THE INSTABILITY IS GREATER ACRS SOUTHERN VT WL BE CAPABLE OF
PRODUCE GUSTY WINDS AND SMALL HAIL. IN ADDITION...AS THE BACKSIDE
DEFORMATION AND ASSOCIATED MOISTURE PIVOT FROM NORTHERN NY INTO
NORTHERN VT THRU MIDNIGHT TONIGHT...LOCALIZED HEAVY RAINFALL WL BE
POSSIBLE. THINKING AN ADDITIONAL 0.50 TO 1.0 OF QPF WL BE POSSIBLE
IN THE COMMA HEAD PORTION OF THE STORM. PRECIP WL BECOME MAINLY
TRRN DRIVEN AFT 03Z...WITH UPSLOPE FLW AND SOME BLOCKING SIGNATURE
NOTED ACRS THE CPV/WESTERN SLOPES. WL CONT TO MENTION HIGH CAT
POPS ACRS THE DACKS INTO PARTS OF THE NORTHERN/CENTRAL GREEN MTNS
AND THE CPV. NOTICED 25 TO 35 KNOTS OF FLW AROUND 1000 FEET AGL
TONIGHT...SO THIS WL LIMIT FOG DEVELOPMENT...BUT SOME PATCHY FOG
AFT 06Z IS POSSIBLE GIVEN SATURATED BL CONDITIONS...ESPECIALLY
DEEPER VALLEYS. TEMPS WL RANGE FROM L50S TO L/M 60S MOST
LOCATIONS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 400 PM EDT MONDAY...LARGE SCALE SYNOPTIC PATTERN WL FEATURE CLOSED 5H/7H
CIRCULATION NEAR HUDSON BAY...WITH WEST TO NORTHWEST FLW ALOFT
ACRS OUR CWA. FCST CHALLENGE WL TIMING INDIVIDUAL S/W`S IN THE FLW
ALOFT AND AMOUNT OF INSTABILITY/MOISTURE AVAILABLE. ON TUESDAY OUR
CWA IS BTWN SYSTEM WITH BETTER 850 TO 500MB MOISTURE ACRS THE
GREAT LAKES...ALONG WITH BETTER S/W ENERGY. HOWEVER...WITH BL
MOISTURE...SOME WEAK INSTABILITY FROM SFC HEATING...AND WEAK
EMBEDDED 5H VORT...CANNOT RULE OUT A POP UP SHOWER OR TWO ACRS THE
MTNS ON TUES AFTN. ANY SHOWERS WL DISSIPATE DURING THE EVENING HRS
WITH PARTLY CLOUD SKIES AND POTENTIAL FOR SOME PATCHY FOG. TEMPS
WL BE IN THE U60S MTNS TO U70S CPV/SLV. ON WEDS LITTLE CHANGE IN
THE SYNOPTIC SCALE PATTERN IS EXPECTED...BUT BOTH NAM/GFS SHOW
BETTER 850 TO 500MB RH PROFILES...SOME WEAK INSTABILITY WITH CAPE
VALUES BTWN 300 AND 500 J/KG...AND WEAK 5H VORT APPROACHING OUR
WESTERN CWA BY 00Z THURS. THIS ALL SUPPORTS THE MENTION OF CHC
POPS WITH THE POTENTIAL FOR A RUMBLE OF THUNDER. PROGGED 85H TEMPS
CHANGE VERY LITTLE WITH WESTERLY FLW ALOFT...SUPPORTING HIGHS
MAINLY IN THE 70S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 301 PM EDT MONDAY...EXTENDED FORECAST CONTINUES TO LOOK
GENERALLY DRY THOUGH SLIGHTLY UNSETTLED DOMINATED BY A SLOW-
MOVING/RETROGRADING UPPER LOW PARKED OVER THE JAMES BAY REGION
AND A BUILDING ATLANTIC RIDGE ALOFT. THE RESULTING WEATHER WILL
BE DAILY CHANCES FOR AFTERNOON SHOWERS AND/OR ISOLATED
THUNDERSTORMS THROUGH SATURDAY. UPPER LOW FINALLY WEAKENS AND
SHIFTS EASTWARD INTO THE GULF OF SAINT LAWRENCE SUNDAY WITH A
WEAK RIDGE DEVELOPING ALOFT LATE SUNDAY INTO MONDAY WITH
SUNNIER/DRIER WEATHER EXPECTED. SLIGHTLY BELOW NORMAL TEMPS ARE
EXPECTED THURSDAY WITH PARTLY SUNNY SKIES AND HIGHS RANGING FROM
THE UPPER 60S TO MID 70S...BUT TREND TOWARDS CLIMO FRO FRIDAY
ONWARD IN THE MID 70S TO LOW 80S. LOWS WILL RANGE THROUGH THE 50S
TO LOCALLY NEAR 60 IN THE CHAMPLAIN VALLEY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...A MIX OF FLIGHT CONDITIONS WILL CONTINUE
ACROSS THE BTV AIRSPACE OVER THE NEXT 12-18 HOURS...EVENTUALLY
TRENDING TO VFR TOWARDS/AFTER 12Z TUESDAY. AS LOW PRESSURE TRACKS
EASTWARD ACROSS NY THEN NORTHEAST ALONG A FRONTAL SYSTEM THROUGH
CENTRAL NEW ENGLAND TO WESTERN ME/SOUTHERN QUEBEC BY 06Z TUESDAY
LIGHT TO MODERATE RAIN WILL CONTINUE ACROSS NORTHERN NY/VT...WITH
THUNDERSTORMS DEVELOPING ACROSS CENTRAL/SOUTHERN VT THIS AFTERNOON.
BEST CHANCE FOR TSRA WILL BE AT KRUT FROM 18-22Z. PRECIP BEGINS TO
DISSIPATE AFTER 03Z WITH MVFR/IFR TRENDING TO VFR AFTER 12Z WHERE
THEREAFTER DIURNAL CUMULUS WILL DEVELOP ACROSS THE HIGHER TERRAIN.

NORTH-NORTHEASTERLY WINDS TODAY TREND TOWARDS THE NORTHWEST LATER
TODAY AND EVENTUALLY GO LIGHT TONIGHT BEFORE PICKING UP AGAIN AT
5-15KTS FROM THE WEST/NORTHWEST TOMORROW.

OUTLOOK 18Z TUESDAY THROUGH SATURDAY...

18Z TUE - 12Z THU...MAINLY VFR. SCATTERED SHOWERS WITH AN ISOLATED
THUNDERSTORM POSSIBLE WEDS AFTERNOON. IFR/LOWER VISIBILITY POSSIBLE IN
OVERNIGHT FOG/MIST MPV/SLK.

12Z THU - 00Z SUN...MAINLY VFR ALTHOUGH BRIEF PERIODS OF MVFR
POSSIBLE IN AN AFTERNOON SHOWER OR THUNDERSTORM.

&&

.MARINE...
LAKE WIND ADVISORY IN EFFECT TONIGHT...997MB LOW PRESSURE NEAR
ALBANY NY WILL TRACK QUICKLY NORTHEAST INTO EASTERN CANADA BY
EARLY TUESDAY MORNING. THE TIGHT CIRCULATION ASSOCIATED WITH THIS
SYSTEM WILL CREATE GUSTY NORTHWEST WINDS AT 20 TO 30 KNOTS ACROSS
THE OPEN WATERS OF LAKE CHAMPLAIN THRU 06Z TONIGHT. THE GRADIENT
AND WINDS BETWEEN 500 AND 1000 FEET ABOVE THE WATER WILL SLOWLY
WEAKEN TOWARD TUESDAY MORNING...RESULTING IN A DROP IN SFC WINDS
TO 10 TO 20 KNOTS. WAVES WILL BUILD 2 TO 4 FEET ON THE OPEN WATERS
TONIGHT...BEFORE SLOWLY SUBSIDING TO 1 TO 2 FEET.

&&

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

&&

$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...LAHIFF
AVIATION...LAHIFF
MARINE...TABER