609
FXUS61 KBTV 290621
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
221 AM EDT SAT AUG 29 2026
WHAT HAS CHANGED
AS OF 221 AM EDT SATURDAY...
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST.
KEY MESSAGES
AS OF 221 AM EDT SATURDAY...
1. HIGH PRESSURE WILL DOMINATE THE REGION TODAY THROUGH EARLY
SUNDAY. RAIN CHANCES, MAINLY NORTH, RETURN DURING THE DAY SUNDAY AS
A COLD FRONT SINKS SOUTH FROM CANADA.
2. A PERIOD OF SHOWER WEATHER IS EXPECTED MID TO LATE WEEK,
WITH A EMPHASIS ON WEDNESDAY NIGHT INTO THURSDAY.
DISCUSSION
AS OF 221 AM EDT SATURDAY...
KEY MESSAGE 1: HIGH PRESSURE WILL CONTINUE TO BUILD IN THIS MORNING
WITH AREAS OF PATCHY VALLEY FOG SCOURING OUT AN HOUR OR TWO AFTER
SUNRISE. MAINLY CLEAR SKIES ASIDE FROM SOME FAIR WEATHER CUMULUS IN
THE HIGHER TERRAIN WILL CREATE A PLEASANT DAY ACROSS THE REGION.
SOME LIGHT BREEZES FROM SOUTHWEST CHANNELED FLOW IN THE ST. LAWRENCE
VALLEY TO 10-20 MPH WILL BE POSSIBLE, IN ADDITION TO LIGHT SOUTHERLY
FLOW IN THE CHAMPLAIN VALLEY TO 15 MPH AS WELL. HIGHS WILL BE
RELATIVELY SEASONABLE IN THE MID 70S. HIGH PRESSURE WILL BEGIN TO
DIP SOUTH LATE THIS EVENING AS A COLD FRONT FROM QUEBEC SINKS SOUTH.
A MODEST LOW-LEVEL JET TO 40-50 KNOTS WILL PRECEDE THE FRONTAL
LEADING TO GUSTY WINDS ON MOUNTAIN SUMMITS. ELEVATIONS ABOVE 2500FT
AGL COULD SEE SOUTHWEST WINDS AROUND 30 MPH, WITH VERY ISOLATED
GUSTS TO NEAR 40 MPH IN THE HIGHEST SUMMITS OF THE ADIRONDACKS. DUE
TO LESS FRICTION, LAKE CHAMPLAIN MAY ALSO SEE 10-20 MPH WINDS
OVERNIGHT. AN INVERSION SHOULD HELP KEEP WINDS IN THE WIDER VALLEYS
AND SHELTERED HOLLOWS GENERALLY UNDER 10 MPH.
ZONAL FLOW AHEAD OF A POSITIVELY TILTED SHORTWAVE, IN ASSOCIATION
WITH THE COLD FRONT, WILL KEEP MOISTURE FAIRLY PROGRESSIVE, BUT SOME
SHOWER ACTIVITY WILL BE POSSIBLE NEAR THE INTERNATIONAL BORDER BY
MID TO LATE SUNDAY. LIFTING ALONG THE FRONT WITH COOL TEMPERATURES
ALOFT MAY LEAD TO SOME WEAK INSTABILITY ON THE SOUTHERN PERIPHERY OF
THE FRONT IN NORTHERN VERMONT AND NEAR THE US-11 CORRIDOR IN
NORTHERN NEW YORK. THE SOUTHERN EXTENT OF THE SHOWER ACTIVITY WILL
BE TRICKY WITH 10-20 DEGREE DEWPOINT DEPRESSIONS SUNDAY AFTERNOON AS
HIGH PRESSURE RETREATS SOUTH. BEST SHOWER CHANCES WILL BE CLOSER TO
THE INTERNATIONAL BORDER DURING THE DAY. RAIN AMOUNTS WILL GENERALLY
BE LOW FROM A FEW HUNDRETHS TO A TENTH OR TWO IN THE WESTERN UPSLOPE
AREAS. THE FRONT WILL SLOWLY SAG SOUTH SUNDAY NIGHT INTO NORTH
CENTRAL VERMONT AND THE NORTHERN ADIRONDACKS. WITH FAIRLY UNIFORM
FLOW UNDER A ZONAL PATTERN, SHOWERS WILL BECOME MORE CONFINED TO THE
WESTERN UPSLOPE REGIONS OF THE GREENS AND ADIRONDACKS THAN THE WIDER
VALLEYS. THE FRONT WILL CONTINUE TO PUSH SOUTH EARLY MONDAY, WITH
MODELS DENOTING IT STALLING OUT JUST SOUTH OF OUR CWA FROM LAKE
ONTARIO INTO THE HUDSON VALLEY AND CURLING TO THE NORTHEAST TOWARDS
MAINE. DRIER NORTHERN AIR WILL FILTER SOUTH INTO THE AREA WITH A
DRYING TREND FOR MONDAY. TEMPERATURES WILL ALSO FALL INTO THE LOW TO
MID 70S WITH THE COOLER NORTH AIR.
KEY MESSAGE 2: THE WEATHER PATTERN WILL FEATURE CHANNELED FLOW AGAINST
A DEEP LAYER HIGH IN THE SOUTHEASTERN US AND A STRONG, COMPACT UPPER
LOW SHIFTING SLOWLY EASTWARD ACROSS CANADA. SYSTEMS WITH PACIFIC
ORIGINS WILL GET SUCKED INTO THIS FAST FLOW BRINGING ROUNDS OF RAIN.
SURFACE HIGH PRESSURE IN FAR EASTERN CANADA WILL TRY AND KEEP WARM,
HUMID AIR FROM LIFTING NORTHEASTWARDS, AND SO WE WILL BE ON THE
STABLE AND DRY SIDE OF THINGS FOR THE MOST PART ON TUESDAY. WE STILL
SHOULD OBSERVE INCREASED CLOUDS AND SOME RAIN ALONG THE SOUTHERN
PORTIONS OF OUR FORECAST AREA. A STRONGER AREA OF LOW PRESSURE WILL
DEVELOP OVER THE GREAT LAKES REGION ON WEDNESDAY, AND THAT SHOULD
PROVIDE THE FOCUS FOR MORE ACTIVE WEATHER CONDITIONS. THE INTERFACE
OF DRY, STABLE CONDITIONS ON THE WESTERN PERIPHERY OF DEPARTING HIGH
PRESSURE AND HUMID, MODIFIED TROPICAL PACIFIC AIR WILL CREATE THE
POTENTIAL FOR SHOWERS AND THUNDERSTORMS BEGINNING LATE WEDNESDAY
AFTERNOON. ELEVATED INSTABILITY COULD ALLOW THUNDERSTORM ACTIVITY TO
PERSIST OVERNIGHT BEFORE THE SYSTEM DEPARTS EARLY THURSDAY MORNING.
SYNOPTIC SCALE MODELS ARE STARTING TO DEPICT THIS FEATURE AS THE ONE
THAT PRODUCES MOST OF OUR RAINFALL NEXT WEEK. DYNAMICALLY, THE
SYSTEM APPEARS QUITE VIGOROUS AND SIMULATED IR SATELLITE OFF THE GFS
IS SHOWING THE POTENTIAL FOR COOL CLOUD TOPS ASSOCIATED WITH THE
ELEVATED CONVECTION AND STRONG ISENTROPIC LIFT. WE'LL CONTINUE TO
KEEP AN EYE ON THIS FEATURE.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
THROUGH 06Z SUNDAY...SKIES ARE MAINLY CLEAR. LOCALIZED FOG HAS BEEN
REPORTED AT KSLK AND KMSS FOR SHORT WINDOWS OF TIME, AS DRY AIR IS
COMPETING WITH OTHERWISE FAVORABLE CONDITIONS FOR RADIATION FOG.
VISIBILITY COULD BE IN AND OUT OF IFR FOR A FEW HOURS AT KSLK BEFORE
PREVAILING IFR CLOSER TO SUNRISE, AND PERHAPS AN HOUR OR TWO DELAYED
AT KMPV GIVEN DRIER AIR PRESENT THERE. AFTER 12Z, FOG WILL DISSIPATE
WITH SLOWLY INCREASING SOUTH TO SOUTHWEST TO THE WEST OF THE GREEN
MOUNTAINS WHILE STAYING MORE WEST TO NORTHWEST NEAR KMPV, KEFK, AND
KRUT. WIND SPEEDS WILL INCREASE TO 6 TO 10 KNOTS IN THE AFTERNOON
WITH GUSTS 15 TO 19 KNOTS POSSIBLE, MAINLY AT KMSS. SURFACE WINDS
WILL DECREASE AFTER 22Z, THOUGH WINDS AT 2000 FT AGL WILL BEGIN TO
INCREASE AHEAD OF A FRONT DESCENDING SOUTHWARDS ON SUNDAY. LLWS HAS
BEEN NOTED ACROSS FAR NORTHERN TERMINALS BEGINNING AROUND 03-04Z
SUNDAY.
OUTLOOK...
SUNDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE SHRA.
MONDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. NO SIG WX.
MONDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
TUESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SHRA,
SLIGHT CHANCE TSRA.
TUESDAY NIGHT: MAINLY MVFR, WITH LOCAL VFR POSSIBLE. LIKELY SHRA,
SLIGHT CHANCE TSRA.
WEDNESDAY: MVFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
BTV WATCHES/WARNINGS/ADVISORIES
VT...NONE.
NY...NONE.
WHAT HAS CHANGED...DANZIG
DISCUSSION...DANZIG/HAYNES
AVIATION...HAYNES
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