018
FXUS61 KBTV 011703
AFDBTV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BURLINGTON VT
103 PM EDT SAT AUG 1 2026
WHAT HAS CHANGED
AS OF 218 AM EDT SATURDAY...
ISOLATED FLASH FLOOD THREAT REMAINS FOR LATE SUNDAY INTO EARLY
MONDAY WITH SLOW-MOVING SHOWERS AND THUNDERSTORMS POSSIBLE.
KEY MESSAGES
AS OF 218 AM EDT SATURDAY...
1. VERY WARM TEMPERATURES AND DRY CONDITIONS SATURDAY
2. INCREASING CHANCES FOR SHOWERS AND EMBEDDED THUNDERSTORMS
SUNDAY AFTERNOON INTO SUNDAY NIGHT. LOCALLY HEAVY RAINFALL POSSIBLE.
3. DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS WITH TEMPERATURE
AT OR ABOVE SEASONAL NORMALS.
DISCUSSION
AS OF 218 AM EDT SATURDAY...
KEY MESSAGE 1: NO SIGNIFICANT WEATHER EXPECTED TODAY OR TONIGHT. PATCHY
EARLY AM FOG MAY BE LOCALLY DENSE IN A FEW OF THE DEEPER RIVER
VALLEYS, BUT WILL GENERALLY DISSIPATE WITH PBL MIXING BETWEEN 12-
13Z. A NARROW RIDGE OF HIGH PRESSURE WILL BRING MOSTLY SUNNY AND
VERY WARM CONDITIONS TO THE NORTH COUNTRY TODAY. WILL SEE AN
INCREASE IN HIGH CLOUD COVER THIS AFTERNOON ASSOCIATED WITH AN
UPSTREAM UPPER TROUGH EXTENDING FROM NORTHERN ONTARIO SOUTHWESTWARD
TO A CLOSED 500MB LOW ACROSS IOWA. EVEN WITH FILTERED SUNSHINE,
850MB TEMPERATURES OF +15C TO +16C WILL SUPPORT VALLEY HIGHS IN THE
MID TO UPPER 80S. SURFACE WINDS WILL BECOME SOUTHERLY AT 5-10 MPH
SUPPORTED BY WEAK SOUTHERLY GRADIENT FLOW. MODEST LOW-LEVEL MOISTURE
ADVECTION WILL GENERALLY KEEP 2-M DEWPOINTS IN THE MID-60S,
RESULTING IN HUMID CONDITIONS AREAWIDE.
FOR TONIGHT...GENERALLY QUIET AND MUGGY CONDITIONS. INVERTED SFC
TROUGH SHIFTS EWD FROM THE OTTAWA VALLEY TOWARD THE ST. LAWRENCE
VALLEY DURING THE PRE-DAWN HOURS ON SUNDAY. THIS WILL BRING A LOW
CHANCE (20-30%) OF SOME RAIN SHOWERS INTO THE ST. LAWRENCE VALLEY
BEFORE DAYBREAK. OTHERWISE, LOOKING FOR OVERNIGHT LOWS IN THE MID-
UPPER 60S, EXCEPT LOCALLY IN THE LOWER 60S EAST OF THE GREEN
MOUNTAINS.
KEY MESSAGE 2: WE'LL BE MONITORING THE SLOW-MOVING UPPER FLOW PATTERN
SUNDAY INTO MONDAY. GENERALLY LOOKING AT A POSITIVE TILT MID-LEVEL
TROUGH ACROSS SERN ONTARIO, WHICH EXTENDS BACK SOUTHWESTWARD TO A
CLOSED LOW IN THE OHIO VALLEY REGION. PREVAILING MID AND UPPER LEVEL
RIDGE OVER EASTERN NEW ENGLAND WILL RESULT IN VERY SLOW MOVEMENT TO
THIS UPSTREAM SYSTEM, BUT IT APPEARS THAT FORCING WILL BE SUFFICIENT
FOR ISOLATED TO SCATTERED SHOWERS BY SUNDAY AFTERNOON, ESPECIALLY
ACROSS NRN NY. WEAK MID-LEVEL LAPSE RATES SUPPORT LIMITED
INSTABILITY, WITH NARROW CAPE PROFILES. HOWEVER, INCREASING PW
VALUES, APPROACHING 1.7-1.9" AND WBZ HEIGHTS NEAR 13KFT WILL SUPPORT
LOCALLY HEAVY RAIN WITH ANY CONVECTIVE ACTIVITY THAT DOES DEVELOP.
SUPPORT FOR SHOWERS AND THUNDERSTORMS EVOLVES EWD ACROSS THE
CHAMPLAIN VALLEY AND ACROSS CENTRAL/NRN VT DURING SUNDAY NIGHT INTO
MONDAY. HAVE INDICATED HIGH POPS (80-90%) WITH WIDESPREAD SHOWERS
AND A FEW EMBEDDED THUNDERSTORMS WITH WEAK CAPE THROUGH THE
OVERNIGHT HOURS. AGAIN, THERMODYNAMIC CONDITIONS DON'T SUPPORT A
SEVERE THREAT, BUT LOCALLY HEAVY RAINFALL IS POSSIBLE. SFC BOUNDARY
EVENTUALLY SETTLES SOUTH AND EAST OF OUR FORECAST AREA LATE MONDAY
AFTERNOON WITH GENERALLY DRYING CONDITIONS FROM NW-SE. AT THE
CURRENT TIME, HAVE INDICATED 0.5 TO 1.0" RAINFALL WITH THIS SYSTEM
ACROSS MOST OF THE NORTH COUNTRY, AND SOME AMOUNTS LOCALLY EXCEEDING
1.0" IN THE ST. LAWRENCE VALLEY. CAN'T RULE OUT A LOCALIZED FLASH
FLOOD THREAT, ESPECIALLY GIVEN SLOW MOVEMENT OF INVERTED TROUGH AND
VERY HIGH PW VALUES. HOWEVER, NOT A STRONG CONSENSUS FOR HEAVY RAIN
OUTSIDE THE ST. LAWRENCE VALLEY AT THE PRESENT TIME, AND AMOUNTS
THERE ARE CURRENTLY NOT EXPECTED TO BE SIGNIFICANT ENOUGH TO PRODUCE
FLOODING OVER THE PREVAILING FLATTER TERRAIN OF THE ST. LAWRENCE
VALLEY. WE WILL CONTINUE TO MONITOR, BUT MOST SECTIONS OF THE NORTH
COUNTRY WILL SEE A PERIOD OF WETTING RAINFALL LATE SUNDAY INTO
SUNDAY NIGHT AND INTO THE FIRST HALF OF MONDAY. DRIER CONDITIONS
GENERALLY RETURN FOR TUESDAY WITH HIGHS IN THE LOW-MID 80S.
KEY MESSAGE 3: A TYPICAL LATE SUMMER PATTERN LOOKS TO SET UP ACROSS THE
REGION FOR THE SECOND HALF OF THE UPCOMING WEEK. DAILY CHANCES FOR
SHOWERS, WITH SOME THUNDERSTORMS POSSIBLE, SEEM LIKELY AS WE SEE 250-
500 J/KG OF CAPE EACH AFTERNOON WITH WEAK SHEAR. THIS SHOULD RESULT
IN PULSE LIKE SHOWERS AND THUNDERSTORMS THAT TRY TO DEVELOP ACROSS
THE HIGHER TERRAIN AND LAKE BREEZES. THERE IS THE POTENTIAL FOR A
ROUND OF ORGANIZED CONVECTION TOWARDS THE END OF NEXT WEEK AS A CUT
OFF LOW OVER THE SOUTHEASTERN US PHASES WITH NORTHERN STREAM ENERGY
AND EJECTS NORTHWARD QUICKLY AHEAD OF A COLD FRONT. HOWEVER,
DETERMINISTIC GUIDANCE IS ALL OVER THE PLACE WITH TRYING TO RESOLVE
HOW THE SOUTHERN STREAM AND NORTHERN STREAM ENERGY INTERACT WITH ONE
ANOTHER. TEMPERATURES EACH AFTERNOON SHOULD EASILY WARM INTO THE
LOWER TO MID 80S BUT GIVEN PERSISTENT CLOUD COVER AND SHOWER
ACTIVITY, IT SEEMS RATHER UNLIKELY ANY LOCATION WILL HIT 90 DEGREES
THIS WEEK.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
THROUGH 18Z SUNDAY...VFR CONDITIONS WILL PERSIST THROUGH THE DAY
TODAY. A SCATTERED TO BROKEN DECK OF FAIR WEATHER CU WILL CONTINUE
TO DEVELOP INTO THE AFTERNOON HOURS WITH A CIRRUS DECK ABOVE. LAST
NIGHT SAW THE DEVELOPMENT OF FOG IN MANY OF OUR FAVORED LOCATIONS,
AND THE LOW LEVEL MOISTURE REMAINS AVAILABLE. HOWEVER, THE LOW
PRESSURE TO OUR WEST WILL BRING INCREASED WINDS AND CLOUDS OVERNIGHT
INHIBITING PURE RADIATIONAL EFFECTS. FOR NOW, I'M INCLUDING SOME
SHALLOW FOG DEVELOPMENT AT MPV AND SLK NEAR SUNRISE BUT DON'T
ANTICIPATE WIDESPREAD FORMATION LIKE WE HAD LAST NIGHT.
OUTLOOK...
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. LIKELY SHRA,
SLIGHT CHANCE TSRA.
MONDAY: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. DEFINITE SHRA,
SLIGHT CHANCE TSRA.
MONDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT CHANCE
SHRA.
TUESDAY: VFR. SLIGHT CHANCE SHRA.
TUESDAY NIGHT: VFR. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
WEDNESDAY: VFR. CHANCE SHRA, CHANCE TSRA.
WEDNESDAY NIGHT: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. CHANCE SHRA,
SLIGHT CHANCE TSRA.
BTV WATCHES/WARNINGS/ADVISORIES
VT...NONE.
NY...NONE.
WHAT HAS CHANGED...BANACOS
DISCUSSION...CLAY/BANACOS
AVIATION...LANGBAUER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page