330
FXUS61 KBTV 282303
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
703 PM EDT FRI AUG 28 2026
WHAT HAS CHANGED
AS OF 237 PM EDT FRIDAY...
NO SIGNIFICANT CHANGES MADE WITH THIS FORECAST PACKAGE.
KEY MESSAGES
AS OF 237 PM EDT FRIDAY...
1. PATCHY VALLEY FOG EXPECTED TONIGHT WITH PLEASANT CONDITIONS
ON SATURDAY, FOLLOWED BY A CHANCE OF SHOWERS LATE SUNDAY AFTERNOON.
2. MODELS TRENDING DRIER FOR TUESDAY BUT RAIN IS EXPECTED TO
RETURN WEDNESDAY AND THURSDAY.
DISCUSSION
AS OF 237 PM EDT FRIDAY...
KEY MESSAGE 1: FIRST FORECAST CHALLENGE IS AREAL COVERAGE/DURATION OF
FOG AFTER MIDNIGHT TONIGHT. SFC ANALYSIS SHOWS 1022MB HIGH PRES OVER
THE THUMB OF EASTERN MI, AS A SFC COLD FRNT EXITS EASTERN NEW
ENGLAND. GOES-19 WATER VAPOR IMAGERY SHOWS LARGE AXIS OF DRY AIR
ALOFT MOVING ACRS THE GREAT LAKES INTO THE NE CONUS THIS AFTN, WHICH
SHOULD HELP QUICKLY ERODE CLOUD COVER BY THIS EVENING, AS SFC
HEATING/INSTABILITY IS DECREASING. SOUNDING DATA INDICATES MODEST
CAA AND DRY AIR ADVECTION CONTINUES THRU 04Z, BEFORE NORTHWEST FLOW
WEAKENS AND SHALLOW INVERSION STRENGTHENS. THIS SHARPENING INVERSION
WITH CLEARING SKIES AND LIGHT WINDS SHOULD ALLOW FOR DEVELOPMENT OF
PATCHY DENSE FOG WITH HIGHEST PROBABILITY (80-90%) IN FAVORED MTN
VALLEYS. TEMPS WL RANGE FROM THE UPPER 30S SLK TO LOWER/MID 50S NEAR
LAKE CHAMPLAIN.
ON SATURDAY 1024MB HIGH PRES WILL BUILD TOWARD KBGM WITH DEEP DRY
LAYER SHIFTING TOWARD CENTRAL NEW ENGLAND BY 18Z, AS A POCKET OF
SLIGHTLY BETTER MOISTURE IN THE 1000-500MB LAYER MOVES OVERHEAD.
THIS COMBINED WITH SOME WEAK INSTABILITY WL HELP PRODUCE SOME
SHALLOW FAIR WX CUMULUS CLOUDS, ESPECIALLY ACRS THE MTNS. PROGGED
925MB TEMPS BTWN 14-16C SUPPORT HIGHS MAINLY IN THE 70S WITH
COMFORTABLE HUMIDITY VALUES. SATURDAY NIGHT IS QUIET WITH SOME
PATCHY FOG, BUT LESS THAN FRIDAY NIGHT, AS 925MB TO 850MB SOUTHWEST
FLOW DEVELOPS WITH SOME INCREASING MOISTURE ADVECTION FROM WEST TO
EAST. LOWS WL BE WARMER WITH VALUES IN THE UPPER 40S TO NEAR 60F.
SUNDAY/SUNDAY NIGHT THE FORECAST CHALLENGE WL BE POTENTIAL FOR
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS AS WEAK FRONT APPROACHES,
ALONG WITH S/W ENERGY. SYNOPTIC SCALE SETUP SHOWS FAST CONFLUENT 700-
500MB FLOW BTWN CLOSED CYCLONIC CIRCULATION OVER EASTERN CANADA AND
BERMUDA RIDGE OVER THE WESTERN ATLANTIC AS WEAK CHANNELED VORTICES
MOVES ACRS OUR CWA. PW VALUES RANGE BTWN 1.25 AND 1.4", WHICH IS
AROUND 1 STD ABOVE NORMAL AHEAD OF APPROACHING COLD FRONT NEAR THE
INTERNATIONAL BORDER, WHILE BEST INSTABILITY IS SOUTH OF OUR CWA.
LATEST TRENDS HAVE SHOWN LESS AREAL COVERAGE OF PRECIP AND MOSTLY
CONFINED TO THE HIGHER TRRN ON SUNDAY AFTN, ESPECIALLY WITH 925 TO
700MB SOUTHWEST DOWNSLOPE FLOW HERE IN THE CPV. AS WINDS SHIFT TO A
FAVORABLE NORTH/NORTHWEST UPSLOPE FLOW BEHIND BOUNDARY A PERIOD OF
LIGHT UPSLOPE RAIN SHOWERS WL BE POSSIBLE ON SUNDAY NIGHT,
ESPECIALLY NORTHERN VT MTNS INTO THE EASTERN CPV. HIGHS SUNDAY WILL
BE IN THE 70S WITH SLIGHTLY HIGHER HUMIDITY WITH LOWS IN THE 50S TO
NEAR 60F AGAIN ON SUNDAY NIGHT.
KEY MESSAGE 2: THE LATEST SUITE OF GLOBAL GUIDANCE IS BRINGING HIGH
PRESSURE ACROSS THE CANADIAN MARITIMES FURTHER SOUTH WHICH IS NOW
EXPECTED TO SUPPRESS MUCH OF THE RAINFALL ACTIVITY ON TUESDAY TO OUR
SOUTH. THERE IS STILL THE POTENTIAL WE COULD SEE MODELS SHIFT NORTH
SLIGHTLY OVER THE NEXT FEW DAYS AS UPPER AIR ANALYSIS BEGINS TO
SAMPLE SEVERAL LOW AMPLITUDE FEATURES IN THE LONGWAVE TROUGH.
HOWEVER, THE IDEA THAT WIDESPREAD RAINFALL ACROSS THE REGION ON
TUESDAY LOOKS UNLIKELY AND THE LATEST FORECAST HAS SHOWS DECREASED
RAIN CHANCES AS A RESULT. THE ECMWF AND GFS BOTH REMAIN IN GOOD
AGREEMENT WITH A SERIES OF FRONTAL BOUNDARIES MOVING ACROSS THE
REGION WEDNESDAY INTO THURSDAY WITH WIDESPREAD RAINFALL LIKELY. DEEP
LAYER RIDGING THEN LOOKS POISED TO DEVELOP ACROSS THE REGION WITH
DRIER CONDITIONS EXPECTED FRIDAY INTO NEXT WEEKEND.
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
THROUGH 00Z SUNDAY...WITH DIURNAL HEATING CUT OFF, CLOUDS WILL ERODE
QUICKLY THIS EVENING. THE CLEAR SKIES AND LIGHT WINDS THAT RESULT
WILL ALLOW THE FAVORED LOCATIONS TO DEVELOP FOG BETWEEN 06-09Z. WITH
CAA AND DRY AIR MOVING IN BEHIND TODAY'S FRONT, FOG WILL BE MORE
PATCHY WITH SLK, MPV, AND EFK GOING IFR. RUT IS A MORE BORDERLINE
SITUATION AND FOR NOW HAVE LEFT IT AS TEMPO. FOG WILL BURN OFF
QUICKLY IN THE MORNING AS THE SHALLOW INVERSION GIVES WAY TO MIXING.
SATURDAY WILL BE PLEASANT ALL AROUND WITH ONLY SOME HIGH CLOUDS TO
DEAL WITH.
OUTLOOK...
SATURDAY NIGHT: VFR. NO SIG WX.
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: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
TUESDAY NIGHT: MAINLY VFR, WITH AREAS MVFR POSSIBLE. LIKELY SHRA,
SLIGHT CHANCE TSRA.
WEDNESDAY: MAINLY MVFR, WITH LOCAL VFR POSSIBLE. CHANCE SHRA,
SLIGHT CHANCE TSRA.
BTV WATCHES/WARNINGS/ADVISORIES
VT...NONE.
NY...NONE.
WHAT HAS CHANGED...TABER
DISCUSSION...CLAY/TABER
AVIATION...LANGBAUER
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