-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBTV 182339
AFDBTV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
739 PM EDT SAT MAY 18 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE NORTH COUNTRY
TODAY INTO SUNDAY. TEMPERATURES AND MOISTURE WILL BEGIN TO
INCREASE BEGINNING ON SUNDAY. A FRONTAL BOUNDARY DROPPING
SOUTHWARD FROM CANADA WILL SERVE AS A FOCUS FOR SHOWERS AND
POSSIBLE THUNDERSTORMS ON MONDAY INTO MONDAY NIGHT. THE FRONTAL
BOUNDARY WILL LINGER AROUND THE NORTH COUNTRY LEADING TO A
CONTINUED UNSETTLED WEATHER PATTERN THROUGH THE REST OF THE WEEK.

&&

.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
AS OF 718 PM EDT SATURDAY...SOME MINOR ADJUSTMENTS TO WX
PARAMETERS BASED ON LATEST INFO OVER THE LAST 3-HR PERIOD...
OTHERWISE FORECAST ON TRACK ATTM. PLENTY OF LOW/MID LEVEL CLDS MVG
THRU THE CWA ATTM. TREND FOR CLRING CONTINUES FOR MUCH OF THE CWA
INTO THE OVERNGT.

PREVIOUS DISCUSSION...VISIBLE SATELLITE SHOWS DIURNALLY-
DRIVEN CUMULUS STREETS ACROSS THE HIGHER TERRAIN WITH A GREATER
COVERAGE OF DIURNAL CUMULUS ACROSS THE NORTHEAST KINGDOM. HAVE
KEPT A SLIGHT CHANCE FOR SHOWERS TO THE NORTHEAST KINGDOM UNTIL
SUNSET. ANY LIGHT SHOWERS AND DIURNAL CUMULUS DISSIPATE AFTER
SUNSET WITH CLEARING SKIES. WHILE THIS SHOULD PROMOTE RAPID SFC
COOLING EARLY OVERNIGHT THOUGH 850 MB TEMPERATURES AROUND +4C
SHOULD KEEP TEMPERATURES FROM GETTING TOO COLD. LOWS TONIGHT RANGE
FROM THE UPPER 30S TO AROUND 40 IN THE TYPICALLY COOLER NORTHEAST
KINGDOM/NORTHERN ADIRONDACKS AREAS TO THE UPPER 40S/AROUND 50 IN
THE VALLEYS.

&&

.SHORT TERM /7 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 334 PM EDT SATURDAY...WE START TO GET INTO MORE OF A
SOUTHERLY RETURN OF LOW-LEVEL MOISTURE ON SUNDAY WITH 500 MB
HEIGHTS CONTINUING TO BUILD. 850 MB TEMPERATURES WILL ALSO BEGIN
TO WARM TO AROUND +7C. GUIDANCE WANTS TO BRING IN PRECIPITATION
FROM TWO MAIN SOURCES ON SUNDAY: (1) INSTABILITY-DRIVEN SHOWERS
AND (2) CONVECTIVE DEBRIS FROM ONGOING CONVECTION OVER THE GREAT
LAKES ACROSS THE NORTHEAST KINGDOM AND ADJACENT TO THE CANADIAN
BORDER. THINK BOTH SOLUTIONS ARE OVERDONE THROUGH SUNDAY AS
CONVECTIVE DEPTH IS CAPPED AND WEST FLOW ALOFT ATOP THE CRESTING
RIDGE SHOULD KEEP ANY DEBRIS SHOWERS NORTH OF THE BORDER. THINK
ALL THIS SHOULD RESULT IN PARTLY TO MOSTLY CLOUDY SKIES WITH
INCREASING CUMULUS DEVELOPMENT. HIGHS ON SUNDAY SHOULD BE CLOSE TO
TODAY...THOUGH A DEGREE OR TWO COOLER GIVEN MORE CLOUDS. BROUGHT
IN A SLIGHT CHANCE OF SHOWERS FOR THE NORTHEAST KINGDOM ON SUNDAY
NIGHT BUT WITH THE REST OF THE NORTH COUNTRY STAYING CLOUDY BUT
DRY. LOW-LEVEL WARM ADVECTION CONTINUES SUNDAY NIGHT WITH
PROJECTED 850 MB TEMPERATURES AROUND +9 TO +10C BY 12Z MONDAY WITH
LOWS GENERALLY IN THE 50S.

A WEAK BAROCLINIC ZONE BEGINS TO DRIFT SOUTHWARD OUT OF CANADA ON
MONDAY...STALLING LATE MONDAY NIGHT ACROSS INTERIOR NEW ENGLAND.
CONVECTIVE INDICES BECOME MORE FAVORABLE FOR THUNDERSTORMS ON
MONDAY AHEAD OF THE FRONTAL ZONE /LIFTED INDICES DROPPING TO AS LOW
AS -2/. HAVE PUT IN CHANCE SHOWERS/SLIGHT CHANCE THUNDER DURING THE
DAYTIME HOURS ON MONDAY MAINLY ACROSS CENTRAL AND SOUTHERN VERMONT
INTO ESSEX COUNTY NEW YORK. WHERE THAT BOUNDARY STALLS OUT WILL
DETERMINE THE NORTHWARD EXTENT OF PRECIPITATION MONDAY NIGHT. WITH
INDICATIONS THAT THE STALLING FRONTAL BOUNDARY WILL LIE ACROSS
CENTRAL NEW ENGLAND HAVE SHOWN TAPERED PRECIPITATION PROBABILITIES
FROM CHANCE TO HIGH CHANCE WITH HIGH CHANCE ACROSS CENTRAL AND
SOUTHERN VERMONT...THE SOUTHERN SAINT LAWRENCE VALLEY AND THE
NORTHERN ADIRONDACKS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 334 PM EDT SATURDAY...FRONTAL BOUNDARY WILL PLAY ACTIVE ROLE
IN WEATHER THROUGHOUT THE EXTENDED. FRONT MOVES SLOWLY SOUTH
ACROSS THE AREA ON TUESDAY FOR A CHANCE OF SHOWERS AND POSSIBLY
SOME THUNDERSTORMS AS INSTABILITY WILL EXIST AHEAD OF THE FRONT.
FLOW ALOFT REMAINS WEST TO NORTHWEST TUESDAY NIGHT INTO
WEDNESDAY...SO BOUNDARY WILL NOT PUSH TO FAR SOUTH. THUS STILL
CANNOT RULE OUT THE POSSIBILITY OF SOME SHOWERS ON WEDNESDAY.
EVENTUALLY FLOW BACKS TO THE SOUTHWEST ON THURSDAY AND FRONT WILL
LIFT BACK NORTH AS A WARM FRONT AND ENHANCE THE POTENTIAL FOR SOME
SHOWERS AND POSSIBLY SOME THUNDERSTORMS. UPPER TROUGH AXIS REMAINS
TO THE WEST THURSDAY NIGHT...BUT MOVES ACROSS THE AREA ON FRIDAY.
THUS LOOKING AT A CHANCE OF SHOWERS FRIDAY AND FRIDAY NIGHT BEFORE
FRONT FINALLY MOVES FAR ENOUGH SOUTH AND THE AIR MASS CHANGES OVER
THE WEEKEND FOR COOLER AND DRIER WEATHER.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
THROUGH 00Z MONDAY...PRIMARILY VFR EXPECTED THROUGH THE PERIOD.
MAY SEE A BRIEF PERIOD OF BR TONIGHT AT MPV...BUT NOT EXPECTED TO
BE WIDESPREAD OR DENSE GIVEN DRIER LOW LEVELS OF THE ATMOSPHERE
COMPARED TO YESTERDAY. HIGH CLOUDS WILL INCREASE TONIGHT AND ON
SUNDAY ALONG WITH THE DEVELOPMENT OF SOME LOWER CUMULUS CLOUDS.
MOST SITES WILL REMAIN DRY...HOWEVER A BRIEF RAIN SPRINKLE OR EVEN
AN ISOLATED SHOWER IS POSSIBLE SUNDAY AFTERNOON. BUT EXPECTED
MINIMAL COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME.
LIGHT AND VARIABLE WINDS TONIGHT WILL TURN SOUTHERLY AND
INCREASE...ESPECIALLY LATE SUNDAY AFTERNOON WHERE SOME GUSTS TO
AROUND 20 KNOTS ARE EXPECTED...ESPECIALLY AT BTV/PBG.

OUTLOOK 00Z MONDAY THROUGH THURSDAY...
A FRONTAL BOUNDARY SAGGING SWD FROM ONTARIO/QUEBEC BRINGS THE
THREAT FOR SHOWERS AND POSSIBLE TSTMS FOR MUCH OF NEXT WEEK. TIMING
UNCERTAINITIES CURRENTLY EXIST BUT ANTICIPATE SEVERAL PERIODS OF
MVFR AND PERHAPS BRIEF IFR CONDITIONS DURING THIS TIME
FRAME...ESPECIALLY TUESDAY AND THURSDAY.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...LOCONTO
NEAR TERM...JN/LOCONTO
SHORT TERM...LOCONTO
LONG TERM...EVENSON
AVIATION...MUCCILLI