109
FXUS61 KBOX 231931
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
331 PM EDT SUN AUG 23 2026
WHAT HAS CHANGED
A HIGH RISK FOR RIP CURRENT STATEMENT HAS BEEN ISSUED FOR NANTUCKET
ON MONDAY.
KEY MESSAGES
- OUTSIDE A FEW SHOWERS/ISOLATED T-STORM RISK INTO MID EVENING
WITH THE FOCUS ACROSS THE INTERIOR ESPECIALLY NEAR AND WEST OF
THE CT RIVER VALLEY. AREAS OF FOG DEVELOP OVERNIGHT WHICH MAY
BECOME LOCALLY DENSE IN SPOTS.
- DRIER WITH A RETURN TO SEASONABLE TEMPERATURES THIS WEEK. RAIN
CHANCES RETURN THURSDAY/FRIDAY.
DISCUSSION
KEY MESSAGE 1...OUTSIDE A FEW SHOWERS/ISOLATED T-STORM RISK INTO MID
EVENING WITH THE FOCUS ACROSS THE INTERIOR ESPECIALLY NEAR AND WEST
OF THE CT RIVER VALLEY. AREAS OF FOG DEVELOP OVERNIGHT WHICH MAY
BECOME LOCALLY DENSE IN SPOTS.
THE MAIN CLUSTER OF SHOWERS THAT RESULTED IN BRIEF HEAVY RAIN ALONG
WITH A RUMBLE OR TWO OF THUNDER HAS EXITED THE EASTERN MA COAST
EARLIER THIS AFTERNOON. BEHIND THIS ACTIVITY SOME SUBSIDENCE AND
DRIER MID LEVEL AIR WAS ALLOWING THE LOWER CLOUDS TO BEGIN TO MIX
OUT FROM SOUTHWEST TO NORTHEAST. WE WILL SEE A LATE RISE IN TEMPS
THROUGH EARLY EVENING WELL INTO THE 70S TO PERHAPS NEAR 80 IN THE CT
RIVER VALLEY AS SOME PEEKS OF SUN TRY TO DEVELOP. THIS WILL RESULT
IN SOME MODEST INSTABILITY DEVELOPING WITH ML CAPES APPROACHING 1000
J/KG ACROSS PARTS OF THE INTERIOR. HOWEVER...SUBSIDENCE BEHIND THE
EARLIER SHORTWAVE COUPLED WITH THE MAIN FORCING WELL TO OUR WEST
WILL LIMIT THE ADDITIONAL RISK. NONETHELESS...A FEW SHOWERS AND
PERHAPS AN ISOLATED T-STORM OR TWO WILL BE POSSIBLE INTO MID-
EVENING. THE MAIN FOCUS FOR THIS ACTIVITY WILL BE ACROSS THE
INTERIOR AND ESPECIALLY NEAR AND WEST OF THE CT RIVER VALLEY CLOSER
TO THE UPPER LEVEL SHORTWAVE.
OTHERWISE...THE MAIN STORY LATER TONIGHT WILL BE FOR THE DEVELOPMENT
OF FOG SOME OF WHICH MAY BECOME LOCALLY DENSE. WINDS BECOME
LIGHT/CALM OVERNIGHT COUPLED WITH PARTIAL CLEARING, WET GROUND AND
DEWPOINTS REMAINING IN THE 60S WILL SET THE STAGE FOR FOG
DEVELOPMENT. SOME OF THE FOG MAY BECOME LOCALLY DENSE TOO. LOW
TEMPERATURES OVERNIGHT WILL DROP INTO THE MIDDLE TO UPPER 50S IN THE
OUTLYING LOCATIONS...TO THE MIDDLE 60S IN THE URBAN HEAT ISLANDS OF
DOWNTOWN BOSTON/PROVIDENCE.
KEY MESSAGE 2...DRIER WITH A RETURN TO SEASONABLE TEMPERATURES THIS
WEEK. RAIN CHANCES RETURN THURSDAY/FRIDAY.
A POST-FRONTAL AIR MASS USHERS IN DRIER CONDITIONS AND WARMER
TEMPERATURES ON WESTERLY WINDS THIS WEEK. AS SKIES GRADUALLY CLEAR
FROM THE DREARY WEEKEND, DEWPOINTS WILL BEGIN TO DROP SLIGHTLY...
INTO THE UPPER 50S AS OPPOSED TO THE LOW TO MID 60S WE'VE BEEN
SEEING. HIGH PRESSURE BEGINS TO SLOWLY BUILD TUESDAY INTO WEDNESDAY,
PROLONGING THE CLEAR SKIES, DRIER WEATHER, AND WARMER TEMPERATURES
THROUGH THE MIDDLE OF THE WEEK. EXPECTING TEMPERATURES TO RETURN TO
SEASONABLE, IN THE UPPER 70S TO LOW 80S, AND FEEL LESS HUMID
THANKS TO THE LOWER DEWPOINTS THROUGH THE END OF THE WEEK.
CHANCES FOR RAIN SHOWERS RETURN THURSDAY AND FRIDAY AS A LOW
PRESSURE SYSTEM DEVELOPS OVER THE GREAT LAKES AND MEANDERS EAST
THROUGH SOUTHERN ONTARIO. SOME UNCERTAINTY REMAINS REGARDING THE
ONSET OF THE SHOWERS AS THERE'S LITTLE CONSISTENCY IN THE GLOBAL
ENSEMBLES ON THE ACTUAL PLACEMENT OF THE LOW AS IT TRACKS THROUGH
CANADA; HOWEVER, CONFIDENCE HAS TICKED UP SLIGHTLY IN A LATER SHOW
OF SHOWERS THURSDAY EVENING INTO THE OVERNIGHT PERIOD COMPARED TO
YESTERDAY'S MODEL RUNS.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...
THIS AFTERNOON THROUGH TONIGHT...MODERATE CONFIDENCE IN TRENDS
BUT LOWER CONFIDENCE IN SPECIFIC TIMING.
THE MAIN CLUSTER OF SHOWERS AND AN OCCASIONAL RUMBLE OF THUNDER
OR TWO WILL BE EXITING EASTERN MA BY MID AFTERNOON.
OTHERWISE...A FEW ADDITIONAL SHOWERS AND PERHAPS AN ISOLATED
T-STORM WILL BE POSSIBLE INTO MID EVENING WITH THE FOCUS ACROSS
INTERIOR SOUTHERN NEW ENGLAND AND PARTICULARLY AREAS NEAR AND
WEST OF THE CT RIVER VALLEY.
IFR/LIFR CONDITIONS WILL BE IMPROVING TO MAINLY MVFR-VFR BY
EARLY-MID EVENING IN MOST LOCATIONS ALTHOUGH THE PROCESS WILL BE
SLOWEST ACROSS THE CAPE/ISLANDS. HOWEVER...A WET GROUND, LIGHT
WINDS AND DEWPOINTS STILL IN THE 60S WILL LIKELY RESULT IN AREAS
OF FOG DEVELOPING IN THE TYPICALLY PRONE LOCATIONS. SOME OF
THAT FOG MAY BECOME LOCALLY DENSE OVERNIGHT...WHILE AREAS LIKE
KBOS END UP GOING VFR. SO A WIDE VARIETY OF CONDITIONS POSSIBLE
TOWARD DAYBREAK. WINDS BECOME CALM/LIGHT SW TONIGHT.
MONDAY AND MONDAY NIGHT...HIGH CONFIDENCE.
ANY LEFTOVER GROUND FOG QUICKLY BURNS OFF AFTER SUNRISE MON.
OTHERWISE...VFR WITH SW WINDS OF 7-13 KNOTS. MAINLY VFR
CONDITIONS CONTINUE MON NIGHT OUTSIDE OF ANY LOCALIZED PATCHES
OF GROUND FOG THAT DEVELOP IN THOSE TYPICALLY PRONE LOCATIONS.
WINDS BECOME CALM/LIGHT SW MON NIGHT.
KBOS TERMINAL...MODERATE CONFIDENCE IN TRENDS BUT LOWER
CONFIDENCE IN SPECIFIC TIMING.
KBDL TERMINAL...MODERATE CONFIDENCE IN TRENDS BUT LOWER
CONFIDENCE IN SPECIFIC TIMING.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: VFR. BREEZY.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: VFR.
THURSDAY: VFR. BREEZY. CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY NIGHT THROUGH FRIDAY: VFR. CHANCE SHRA, SLIGHT CHANCE
TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT THROUGH MONDAY NIGHT...HIGH CONFIDENCE.
THE PRESSURE GRADIENT WILL GENERALLY REMAIN WEAK ENOUGH TO KEEP
WINDS/SEAS BELOW SMALL CRAFT ADVISORY THROUGH MONDAY NIGHT.
HOWEVER...NEARSHORE SW WINDS MAY GUST INTO THE LOWER 20 KNOTS LATE
MONDAY RESULT IN SOME DECENT CHOP FOR RECREATIONAL BOATERS.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY NIGHT THROUGH THURSDAY: WINDS LESS THAN 25 KT.
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT. CHANCE OF
RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...HIGH RISK FOR RIP CURRENTS FROM MONDAY MORNING THROUGH MONDAY
AFTERNOON FOR MAZ024.
RI...NONE.
MARINE...NONE.
DISCUSSION...FRANK/MCMINN
AVIATION...FRANK/MCMINN
MARINE...FRANK/MCMINN
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