134
FXUS61 KBOX 091758
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
158 PM EDT TUE SEP 9 2025
SYNOPSIS
DRY WEATHER PREVAILS MOST OF THIS WEEK AND WEEKEND AS HIGH PRESSURE
REMAINS OVER NEW ENGLAND. SEASONABLE TO SLIGHTLY COOLER THAN NORMAL
TEMPERATURES CAN BE EXPECTED. A COASTAL LOW PRESSURE SYSTEM BRINGS A
SOME RAIN SHOWERS WEDNESDAY; BEST CHANCE IS ON CAPE COD AND THE
ISLANDS BUT CAN'T RULE OUT SOME SHOWERS FURTHER INLAND.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES...
* SUNNY TO START WITH INCREASING CLOUDS IN THE AFTERNOON AND EVENING
FROM THE SOUTHEAST.
* HIGHS IN THE LOW TO MID 70S; LOWS IN THE LOW 60S ON THE CAPE AND
ISLANDS WHILE INTERIOR HIGH TERRAIN LOCATIONS MAY DROP INTO THE
40S!
* BREEZY, ESPECIALLY IN SOUTHEAST MA.
A QUIET AND COOLER THAN AVERAGE DAY IS ON TAP FOR TODAY UNDER THE
INFLUENCE OF A SPRAWLING HIGH PRESSURE OVER NOVA SCOTIA. THIS,
COMBINED WITH AN APPROACHING COASTAL LOW WELL TO OUR SOUTH WILL
DIRECT INCREASINGLY BREEZY COOL NORTHEAST WIND OVER SOUTHERN NEW
ENGLAND KEEPING HIGHS IN THE LOW 70S EAST, MID 70S IN THE TYPICALLY
WARMER CT VALLEY. WINDS WILL GUST 20-25 MPH OVER THE CAPE AND
ISLANDS, LESS SO FURTHER TO THE NORTH AND WEST. A SMALL CRAFT
ADVISORY WILL BE IN EFFECT FOR THE SOUTHERN OUTER WATERS. TONIGHT
SAID COASTAL LOW WILL MOVE A BIT CLOSER BRINGING A PLUM OF MOISTURE
OUT AHEAD OF IT. THUS, EXPECTING LOW CLOUDS TO ENCROACH ON THE
SOUTHEAST COAST, EXPANDING TO THE NORTH AND WEST THROUGH THE NIGHT.
THERE IS POTENTIAL FOR SOME DRIZZLE OR LIGHT RAIN AS EARLY AS
TUESDAY NIGHT, BUT SOUNDING INDICATE A DECENT AMOUNT OF DRY AIR TO
OVERCOME, SO MORE LIKELY THAT IT IS LIMITED TO LOW STRATUS CLOUDS
UNTIL WEDNESDAY. THE EXACT TIMING OF THESE INCOMING CLOUDS WILL HAVE
A BIG IMPACT ON LOW TEMPERATURES AS THEY CUT OFF RADIATIONAL
COOLING; CURRENTLY LOOKING LIKE WE SHOULD STILL BE ABLE TO RADIATE
EARLY IN NORTHWEST SNE, DOWN INTO THE UPPER 40S/LOW 50S WHILE AREAS
ON CAPE COD MAY ONLY DROP TO THE LOW 60S.
SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/
KEY MESSAGES...
* RAIN SHOWERS POSSIBLE WEDNESDAY AND WEDNESDAY NIGHT; BEST CHANCE
OVER THE SOUTH COAST BUT MAY EXPAND INTO NORTHERN CT/RI/EASTERN
MA.
* COOLER, IN THE UPPER 60S FOR MOST.
WEDNESDAY THE COASTAL LOW MOVES OFF THE NORTH CAROLINA COAST AND
PASSES OFFSHORE, SOUTHEAST OF THE 70/40 BENCHMARK. THIS WILL LIMIT
ITS IMPACT ON THE REGION TO THICKENING CLOUDCOVER FOR MOST, THOUGH
RAIN SHOWERS ARE POSSIBLE GENERALLY SOUTH OF THE MA/CT BORDER; BEST
ODDS ARE THE IMMEDIATE SOUTHEAST COAST WITH LESSENING RAIN CHANCES
TO THE NORTH AND WEST. EPS ENSEMBLE HAS INCREASED THE ODDS OF >0.1"
OF RAIN ON WEDNESDAY IN THE LAST 24 HOURS THOUGH IT REMAINS THE MOST
BULLISH; POPS HAVE BEEN INCREASED/EXPANDED NORTH SLIGHTLY INTO MUCH
OF CT.
LONG TERM /THURSDAY THROUGH MONDAY/
KEY MESSAGES...
* MOSTLY DRY.
* SEASONABLE TEMPERATURES WITH THE WARMEST DAY BEING THURSDAY.
THURSDAY LOW PRESSURE PULLS AWAY LEAVING A BUILDING HIGH PRESSURE IN
ITS PLACE. THIS HIGH WILL DRIVE WEATHER THROUGH THE WEEKEND LEADING
TO DRY AND SEASONABLE WEATHER. THE WARMEST DAY WILL BE THURSDAY AS
HIGHS PUSH INTO THE UPPER 70S/LOW 80S. THIS IS AHEAD OF A MID LEVEL
COLD FRONT THAT SINKS SOUTH BEHIND THE EXITING SYSTEM DROPPING 925
MB TEMPS FROM +18C TO +12C; EXPECT HIGH TEMPERATURES BACK IN THE LOW
70S THROUGH THE REST OF THE FORECAST WITH LOWS IN THE 40S AND 50S.
AVIATION /18Z TUESDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THROUGH 00Z WEDNESDAY: HIGH CONFIDENCE.
VFR, ALTHOUGH CLOUDS WILL BE INCREASING FOR SOUTHEAST AIRPORTS;
CEILINGS MAY BECOME MVFR AT ACK AS SOON AS 00Z BUT MORE LIKELY
AFTER 00Z. NE TO E WINDS AROUND 5-10 KT FOR INTERIOR SOUTHERN
NEW ENGLAND AIRPORTS, AND AROUND 10-13 KT WITH GUSTS TO 22 KT
FOR EASTERN MA, RI AND THE CAPE AND ISLANDS.
TONIGHT: HIGH CONFIDENCE IN TRENDS, BUT MODERATE ON TIMING AND
NORTHWESTWARD COVERAGE OF STRATUS.
VFR BEGINS TO GRADUALLY DETERIORATE THROUGH THE NIGHT TO BKN/OVC
MVFR STRATUS, SOONEST ACROSS THE CAPE AND ISLANDS (01-02Z), AND
BETWEEN 04-08Z FOR MOST OTHER TAFS. SPOTTY RAIN SHOWERS OR EVEN
DRIZZLE OVERNIGHT, WITH THE BEST CHANCE OVER SOUTHEAST
AIRPORTS. NE WINDS 5-10 KT, AROUND 10-15 KT WITH GUSTS 25 KT
CAPE AND ISLANDS.
WEDNESDAY: MODERATE CONFIDENCE.
MVFR (MVFR/IFR CAPE AND ISLANDS) TO START WITH SPOTTY RAIN
SHOWERS MAINLY SOUTH AND EAST OF THE MASS PIKE. SLOW, GRADUAL
IMPROVEMENT TO SCT VFR THROUGH THE AFTN, BUT THE EXACT TIMING IS
UNCERTAIN. IT WILL LIKELY TAKE LONGER FOR THE CAPE AND ISLANDS
TO SEE IMPROVEMENT AND THEY MAY REMAIN SUB-VFR ALL DAY. NE WINDS
AROUND 5-10 KT INTERIOR / 10-15 KT WITH GUSTS TO 25 KT CAPE AND
ISLANDS, GRADUALLY BECOMING NNE/N THROUGH THE AFTERNOON.
WEDNESDAY NIGHT: HIGH CONFIDENCE.
EARLY MVFR-IFR FOR THE CAPE AND ISLANDS BUT SHOULD TRANSITION TO
ALL VFR OVERNIGHT. PATCHY FOG POSSIBLE. LIGHT NORTH WINDS.
KBOS TERMINAL...HIGH CONFIDENCE.
KBDL TERMINAL...HIGH CONFIDENCE.
OUTLOOK /THURSDAY THROUGH SATURDAY/...
WEDNESDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA.
THURSDAY THROUGH FRIDAY: VFR. BREEZY.
FRIDAY NIGHT THROUGH SATURDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
SMALL CRAFT ADVISORIES ARE IN EFFECT TODAY THROUGH WEDNESDAY FOR THE
FAR SOUTHERN WATERS, AS SEAS BUILD TO AROUND 4-6 FT. NE WINDS WILL
BE INCREASING TODAY WITH WINDS 15-20 KT AND GUSTS 25 KT, AND AROUND
10-15 KT OVER THE NORTHEAST WATERS. THESE CONDITIONS SHOULD REMAIN
STEADY THROUGH TONIGHT AS WELL. LOW CHANCE AT PATCHY DRIZZLE OR A
LIGHT RAIN SHOWER, WITH BETTER CHANCES OVER THE SOUTHEAST OUTER
WATERS. RAIN SHOWERS INCREASE IN COVERAGE ON WEDNESDAY.
OUTLOOK /THURSDAY THROUGH SATURDAY/...
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE
OF RAIN SHOWERS.
THURSDAY THROUGH THURSDAY NIGHT: WINDS LESS THAN 25 KT. AREAS
OF SEAS APPROACHING 5 FT.
FRIDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
SATURDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR ANZ254.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR ANZ255-256.
SYNOPSIS...BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...BW
AVIATION...LOCONTO/BW/MENSCH
MARINE...BW
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