231
FXUS61 KBOX 290521
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
121 AM EDT TUE SEP 29 2026
WHAT HAS CHANGED
FLOOD WATCH HAS BEEN CANCELLED. SMALL CRAFT ADVISORIES FOR
BOSTON HARBOR AND NARRAGANSETT BAY HAVE ALSO BEEN TAKEN DOWN AS
CONDITIONS BEGIN TO IMPROVE.
KEY MESSAGES
- SLOWLY IMPROVING WEATHER OVERNIGHT AND TUESDAY AS THE
NOR'EASTER WEAKENS AND MOVES AWAY
- WARM AND DRY CONDITIONS ARRIVE WEDNESDAY THROUGH FRIDAY
FOLLOWED BY A CHANCE FOR RAINY AND UNSETTLED CONDITIONS THIS
WEEKEND
DISCUSSION
KEY MESSAGE 1...SLOWLY IMPROVING WEATHER OVERNIGHT AND TUESDAY AS
THE NOR'EASTER WEAKENS AND MOVES AWAY.
ALTHOUGH THE LOW LEVEL SWIRL AROUND THE CENTER OF THE NOR'EASTER
SOUTH OF LONG ISLAND LOOKS IMPRESSIVE ON SATELLITE IMAGERY, THE
STORM IS QUICKLY WEAKENING AS IT'S STARTING TO MOVE MORE QUICKLY TO
THE NORTHEAST. STILL A GOOD AMOUNT OF MOISTURE, WRAPPED AROUND THE
CIRCULATION, PRODUCING A FAIRLY LARGE AREA OF LIGHT RAINFALL.
HOWEVER AS THE DYNAMICS WEAKEN, THE RAINFALL INTENSITY IS ALSO ON A
DOWNWARD TREND. EXPECT MOST AREAS WILL SEE LESS THAN 1/2" OF
ADDITIONAL RAINFALL FROM THIS POINT FORWARD. MODELS ARE ALL IN GOOD
AGREEMENT IN TAKING THE LOW ACROSS THE CAPE OVERNIGHT AND THEN INTO
THE GULF OF MAINE ON TUESDAY. SURFACE WINDS WILL SLOWLY TRANSITION
FROM NNE TO NNW AND THEN NW BY TUESDAY MORNING - EXCEPT ACROSS OUR
SOUTHERN COASTAL WATERS AND NANTUCKET, WHICH WILL SEE WINDS GO FROM
THE SE TO SW AND EVENTUALLY W SINCE THE LOW CENTER WILL PASS NORTH
OF THOSE AREAS. MODEL FORECAST CROSS-SECTIONS INDICATE LOW LEVEL
MOISTURE WILL BE SLOW TO LEAVE TOMORROW, SO EXPECT A GENERALLY
MOSTLY CLOUDY DAY. BETTER CHANCES FOR SOME AFTERNOON SUNSHINE WILL
BE ACROSS WESTERN AREAS. THERE IS NO BLOB OF COLD AIR THAT WILL COME
IN BEHIND THE NOR'EASTER, AND IN FACT 925MB TEMPERATURES WILL BE A
LITTLE WARMER THAN THEY WERE TODAY. SO GIVEN THAT AND SOME BREAKS OF
SUNSHINE, TEMPERATURES WILL BE IN THE MID TO UPPER 60S FOR MOST, AND
A FEW LOCATIONS - ESPECIALLY IN THE CT RIVER VALLEY - COULD HIT
70F.
ALSO, GIVEN THE DOWNWARD TRENDS IN RAINFALL, HAVE GONE AHEAD AND
CANCELLED THE FLOOD WATCH. ALTHOUGH SOME MINOR FLOODING IS STILL
EXPECTED ALONG PORTIONS OF THE TAUNTON RIVER, WE DON'T
ANTICIPATE ANY INCREASE IN RISK FOR FLOODING ACROSS THE AREA.
KEY MESSAGE 2...WARM AND DRY CONDITIONS ARRIVE WEDNESDAY THROUGH
FRIDAY FOLLOWED BY A CHANCE FOR RAINY AND UNSETTLED CONDITIONS THIS
WEEKEND.
A MID-LEVEL RIDGE BUILDS ACROSS THE SOUTHEASTERN CONUS THIS WEEK,
WHILE SURFACE HIGH PRESSURE SETTLES SOUTH OF THE REGION WEDNESDAY
THROUGH FRIDAY, LEADING TO A STRETCH OF QUIETER AND WARMER WEATHER.
GUIDANCE HINTS AT A WEAK NORTHERN-STREAM SHORTWAVE WEDNESDAY NIGHT
INTO EARLY THURSDAY, FOLLOWED BY A SECONDARY SHORTWAVE THURSDAY
NIGHT INTO FRIDAY. PWATS WEDNESDAY NIGHT INTO THURSDAY REMAIN BELOW
1.2 INCHES AND DO NOT ALIGN PARTICULARLY WELL WITH THE BEST FORCING.
OUTSIDE OF A BRIEF LIGHT SHOWER, WOULD ANTICIPATE MORE CLOUDS THAN
ANYTHING. PWATS INCREASE TO AROUND 1.5 INCHES THURSDAY NIGHT WITH
THE PASSAGE OF THE SECONDARY WEAK SHORTWAVE, WHEN A FEW LIGHT
SHOWERS COULD BRUSH THE REGION. NO SIGNIFICANT IMPACTS ARE
ANTICIPATED WITH EITHER DISTURBANCE. TEMPERATURES TREND WARMER
THROUGH THE MIDDLE AND LATTER HALF OF THE WEEK, THOUGH THE LATEST
GUIDANCE HAS TRENDED SOMEWHAT COOLER COMPARED TO PREVIOUS RUNS.
HIGHS GENERALLY RETURN TO THE LOWER AND MIDDLE 70S, WITH THURSDAY
POTENTIALLY THE WARMEST DAY AS TEMPERATURES REACH THE MIDDLE TO
UPPER 70S. NO NOTABLE COLD IS EXPECTED OVERNIGHT, WITH LOWS
GENERALLY FALLING INTO THE 50S.
FORECAST BECOMES A BIT MORE INTERESTING BY LATE NEXT WEEK AS A
STRONG CONTINENTAL HIGH PRESSURE SYSTEM ARRIVES FROM SE CANADA.
GUIDANCE SHOWS A RATHER SHARP DROP IN TEMPERATURES WITH 850
TEMPS FALLING FROM +15-17C FRIDAY TO +4-6C ON SATURDAY. BEYOND
THIS FRONT, GUIDANCE IS BEGINNING TO COME INTO BETTER AGREEMENT
WITH DEPICTING A STRONG AREA OF LOW PRESSURE ACROSS SE CANADA ON
SUNDAY. THERE REMAINS A VARIETY OF SOLUTIONS WITH THE GFS/ICON
DEPICTING SECONDARY CYCLOGENESIS ALONG A FRONTAL BOUNDARY NEAR
THE CAROLINAS AND THE ECMWF/CMC LEANING MORE TOWARDS A STRONG
FRONTAL BOUNDARY. IN ANY CASE, THE SECOND HALF OF THE WEEKEND
LOOKS WET AND UNSETTLED. BEHIND THIS FEATURE, GUIDANCE DEPICTS A
MUCH COLDER AIRMASS MOVING IN FROM CANADA WITH 850MB TEMPS
FALLING BELOW ZERO LATER MONDAY THROUGH WEDNESDAY. THESE MID-
LEVEL TEMPS WOULD SUPPORT HIGHS IN THE 40S AND 50S WITH
NIGHTTIME LOWS POSSIBLY FALLING INTO THE 30S DEPENDING ON
RADIATIONAL COOLING.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE...
TODAY...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING.
IFR TO OCCASIONALLY LIFR CONDITIONS CONTINUE THROUGH THE NIGHT
AND INTO THE MORNING HOURS. LOW CIGS AND VISBYS WITH LINGERING
BR/-DZ AS THE LOW MOVES OFFSHORE THROUGH THE MORNING.
CONDITIONS IMPROVE THORUGH THE MORNING TO AT LEAST MVFR,
POTENTIALLY VFR ACROSS THE INTERIOR. GUIDANCE SUGGESTS LOW LEVEL
MOISTURE WILL REMAIN IN PLACE, RESULTING IN WIDESPREAD CEILINGS
OF 2K-2.5KFT FOR MOST AREAS MUCH OF THE DAY, ALTHOUGH THERE MAY
BE PATCHY 3K CIGS AT TIMES.
TONIGHT...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN
TIMING.
MVFR CONDITIONS CONTINUE TO IMPROVE TO VFR THROUGHOUT THE
EVENING AND OVERNIGHT PERIOD. NW WINDS BACK TO W/WSW AS THE LOW
CONTINUES TO PUSH OFFSHORE.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. NW WINDS 5-10 KTS
WITH GRADUAL IMPROVEMENT TO MVFR BY THE AFTERNOON. WILL LIKELY
NOT IMPROVE TO VFR.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT: VFR.
THURSDAY THROUGH THURSDAY NIGHT: VFR. BREEZY.
FRIDAY: VFR. SLIGHT CHANCE SHRA.
FRIDAY NIGHT: VFR. CHANCE SHRA.
SATURDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
OVERALL HIGH CONFIDENCE.
THE CENTER OF THE LOW PUSHES OFFSHORE AND TOWARDS THE GULF OF
MAINE LATER TODAY AFTER PASSING OVER CAPE COD. WINDS WILL
CONTINUE TO DIMINISH THROUGH THE EARLY MORNING HOURS. SEAS WILL
ALSO CONTINUE TO SUBSIDE, BUT THE EASTERN WATERS LINGER AROUND 4
TO 5 FEET THORUGH THE MORNING. HIGH PRESSURE BEGINS TO BUILD IN
LATER TONIGHT INTO WEDNESDAY, PROVIDING AN EXTENDED PERIOD OF
SW WINDS THROUGH THE END OF THE WEEK.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT THROUGH THURSDAY: WINDS LESS THAN 25 KT. SEAS
LOCALLY APPROACHING 5 FT.
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT. SEAS UP
TO 5 FT.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF RAIN SHOWERS.
SATURDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ250-
251.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ254.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
ANZ255-256.
DISCUSSION...MCMINN
AVIATION...MCMINN
MARINE...MCMINN
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