604
FXUS61 KBOX 290603
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
203 AM EDT WED OCT 29 2025
SYNOPSIS
CANADIAN HIGH PRESSURE WILL RESULT IN COOL TEMPERATURES THROUGH
TOMORROW NIGHT WITH SCATTERED SHOWERS POSSIBLE, MAINLY NEAR AND
SOUTHEAST OF I-95. STRONG LOW PRESSURE FOLLOWS WITH A PERIOD OF
HEAVY WINDSWEPT RAIN FOR SOUTHERN NEW ENGLAND LATER THURSDAY
AND THURSDAY NIGHT. DRYING OUT FOR FRIDAY WITH GUSTY WINDS WHICH
LINGER INTO SATURDAY. DRY WEATHER IS LIKELY FRIDAY INTO NEXT
WEEK.
NEAR TERM /THROUGH TODAY/
KEY MESSAGES:
* BREEZY NE WINDS, MAINLY FOR CAPE/ISLANDS WITH GUSTS 20-30 MPH.
* SLIGHTLY BELOW NORMAL TEMPERATURES WITH A FEW SHOWERS POSSIBLE
MAINLY SOUTHEAST OF I-95.
TONIGHT
A STEADY NORTHEAST FLOW ASSOCIATED WITH A COASTAL LOW-PRESSURE
SYSTEM OFF THE MID-ATLANTIC COAST WILL CONTINUE TO BLANKET SOUTHERN
NEW ENGLAND WITH MARINE STRATUS, LIMITING HOW MUCH TEMPERATURES CAN
FALL OVERNIGHT. EXPECT A MILDER NIGHT THAN LAST, WITH LOWS IN THE
LOW TO MID-40S ACROSS SOUTHEASTERN MASSACHUSETTS AND THE CAPE, WHERE
OVERCAST SKIES AND MECHANICAL MIXING FROM PERSISTENT NORTHEAST WINDS
WILL INHIBIT RADIATIONAL COOLING. FARTHER NORTH AND WEST ACROSS THE
INTERIOR, PARTIAL CLEARING AND A DECOUPLED BOUNDARY LAYER WILL ALLOW
FOR LOWER TEMPERATURES, RANGING FROM THE MID-30S TO LOW 40S.
OVERALL, A DRY AND QUIET NIGHT IS EXPECTED, THOUGH A FEW LIGHT
SHOWERS MAY OCCUR OVER THE CAPE AND ISLANDS IN ASSOCIATION WITH THE
OFFSHORE LOW.
SHORT TERM /TONIGHT THROUGH 6 PM THURSDAY/
KEY MESSAGES:
* COOLER TEMPERATURES CONTINUE WED WITH SCATTERED OCEAN-EFFECT
SHOWERS MAINLY NEAR/SOUTHEAST I-95.
DETAILS...
TOMORROW
LITTLE CHANGE IS EXPECTED FROM TODAY’S WEATHER PATTERN. A BROKEN TO
OVERCAST CLOUD DECK BETWEEN 2,000 AND 3,000 FEET WILL PERSIST,
ACCOMPANIED BY STEADY NORTHEAST WINDS. HIGH TEMPERATURES WILL AGAIN
RANGE FROM THE LOW TO MID-50S. WINDS WILL REMAIN SUSTAINED AT 10 TO
15 KNOTS, WITH OCCASIONAL GUSTS UP TO 25 KNOTS POSSIBLE ACROSS THE
CAPE, ISLANDS, AND COASTAL AREAS.
DEEP-LAYER MOISTURE INCREASES THROUGH THE DAY, WITH PWATS RISING TO
0.8–1.0 INCHES ACROSS EASTERN MASSACHUSETTS AND RHODE ISLAND. THIS
WILL SUPPORT INCREASING SHOWER CHANCES DURING THE EARLY TO MID-
AFTERNOON HOURS. EXPECT A FEW LIGHT SHOWERS TO DEVELOP, BUT
OTHERWISE ANOTHER COOL AND QUIET AUTUMN DAY.
TOMORROW NIGHT
MORE OF THE SAME PATTERN CONTINUES INTO TOMORROW NIGHT, WITH THE
OFFSHORE LOW MAINTAINING STEADY NORTHEAST WINDS AND OVERCAST SKIES.
LOWS WILL AGAIN RANGE FROM THE MID TO UPPER 40S ACROSS SOUTHEASTERN
MASSACHUSETTS TO THE MID-30S AND LOW 40S INLAND. THE MAIN CHANGE
WILL BE AN INCREASING CHANCE OF SHOWERS ACROSS SOUTHERN NEW ENGLAND
AS LOW LEVELS CONTINUE TO MOISTEN AND PWATS APPROACH 0.8 INCHES. UP
TO A TENTH OF AN INCH POSSIBLE FOR PORTIONS OF SOUTHEAST MA BY
THURSDAY AM.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
KEY MESSAGES:
* PERIOD OF HEAVY RAINFALL AND GUSTY WINDS EXPECTED THU INTO THU
NIGHT.
* BRIEF NUISANCE STREET FLOODING POSSIBLE & 30-50 MPH GUSTS ON
THE COAST
* GRADUAL CLEARING FRIDAY WITH POTENTIAL FOR GUSTY WESTERLY
WINDS.
DETAILS...
KEY MESSAGES...
* A QUICK HITTING STORM WILL BRING A PERIOD OF HEAVY RAIN AND GUSTY
WINDS THURSDAY INTO THURSDAY NIGHT.
* SOME ISOLATED NUISANCE STREET FLOODING IS POSSIBLE, EXACERBATED BY
ABUNDANCE OF FALLEN LEAVES.
* WINDS WILL BECOME INCREASINGLY BREEZY LATE THURSDAY BUT REALLY
WINDY ON FRIDAY BEHIND THE RAIN.
* DRY AND A BIT COOLER THAN SEASONABLE THROUGH EARLY NEXT WEEK.
THE FOCUS OF THE EXTENDED FORECAST WILL BE ON A STORM SYSTEM MOVING
THROUGH LATE THURSDAY AND THURSDAY NIGHT. WE'LL SEE A DEEPENING
SURFACE LOW PRESSURE LIFT FROM THE DEEP SOUTH INTO THE MID-
ATLANTIC THURSDAY AND INTO MAINE BY FRIDAY. THIS HAPPENS WHILE
AT THE MID LEVELS A DEEP TROUGH DIGS INTO THE EASTERN SEABOARD,
LIFTING NORTHEAST AT THE SAME SPEED.
WHAT THIS MEANS FOR SOUTHERN NEW ENGLAND IS A PERIOD OF HEAVY RAIN
AND BREEZY WINDS AS DEEP, MOIST, SW FLOW AHEAD OF THE TROUGH ADVECTS
PWATS OF NEAR 1.75" COINCIDENT WITH A 45-55 KT 85MB LLJ ALL WHILE
BENEATH THE RRQ OF A 125KT UPPER JET. THIS AMPLE MOISTURE AND
FORCING WILL LEAD TO A STRETCH OF WIDESPREAD, SOMETIMES HEAVY RAIN
WHICH IS POISED TO DROP 1 TO 3 INCHES OF RAIN ACROSS THE REGION.
FORTUNATELY THIS IS A PROGRESSIVE SYSTEM SO THE PERIOD OF HEAVIEST
RAIN SHOULD BE QUICK ENOUGH TO AVOID MUCH IN THE WAY OF FLOODING
IMPACTS. IT ALSO LOOKS TO BE HEAVIEST OVERNIGHT, BETWEEN THE
THURSDAY EVE AND FRIDAY MORN COMMUTES WHICH WOULD MINIMIZE IMPACTS.
THAT BEING SAID, GIVEN THE AMOUNT OF LEAVES READY TO FALL AND
ALREADY ON THE GROUND WE COULD SEE NUISANCE STREET FLOODING. THE
LOCATION OF THE HEAVIEST RAINFALL WILL DEPEND ON THE EXACT TRACK OF
THE LOW BUT AT THIS TIME ENSEMBLE GUIDANCE PLACES IT OVER CAPE COD
AND THE ISLANDS WITH A 20-40% CHANCE OF AOA 2 INCHES OF RAIN IN 24
HOURS.
FRIDAY AFTER SUNRISE THE DRY SLOT RUSHES IN AND MUCH, IF NOT ALL OF
THE DAY SHOULD BE DRY WITH PARTLY SUNNY SKIES AND ONLY A POP UP
SHOWER OR TWO THANKS TO THE COLD POOL OVERHEAD. THE BIGGEST STORY
FOR FRIDAY INTO SATURDAY WILL BE THE GUSTY WINDS AS A COLD ADVECTION
PATTERN MIXES DOWN A 45-55 KT LLJ. WIND HEADLINES MAY BE NEEDED
FRIDAY AND/OR FRIDAY NIGHT.
FOR THE WEEKEND THE PRESSURE GRADIENT RELAXES A BIT BUT IT WILL
STILL BE WINDY ON SATURDAY BEFORE CALMING DOWN SUNDAY. DRY AND NEAR
SEASONABLE WEATHER (A FEW DEGREES COOLER THAN AVERAGE) WITH HIGHS IN
THE LOW TO MID 50S THEN CONTINUES AS SURFACE HIGH PRESSURE MOVES
OVERHEAD WITH MID LEVEL RIDGING BY MONDAY.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE:
WEDNESDAY...HIGH CONFIDENCE.
MVFR CEILINGS AND STEADY NORTHEAST WINDS 8-12 KTS WITH GUSTS
AROUND 20 KTS FOR BOS AND STRONGER (20+KTS) FOR THE CAPE AND
ISLANDS. A FEW LIGHT SHOWERS MAY DEVELOP NEAR THE EAST COAST,
CAPE, AND ISLANDS BY EARLY TO MID AFTERNOON. GUSTS DECREASE IN
THE LATE AFTERNOON FOR BOS AND GRADUALLY WEAKEN FOR CAPE/ISLANDS
IN THE EVENING.
WEDNESDAY NIGHT... HIGH CONFIDENCE.
MVFR CEILINGS AND STEADY NORTHEAST WINDS AROUND 10 KNOTS.
ISOLATED BRIEF SHOWER/SPRINKLE POSSIBLE FOR EAST/SOUTHEAST
TERMINALS.
THURSDAY...HIGH CONFIDENCE. MODERATE FOR EXACT TIMING OF RAIN.
MVFR CEILINGS WITH IFR DEVELOPING AS THE RAIN ARRIVES WITH AN
INCOMING SYSTEM. RAIN ARRIVES GENERALLY FROM WEST TO EAST
THURSDAY AFTERNOON/EARLY EVENING CONTINUING THURSDAY NIGHT.
KBOS TERMINAL... HIGH CONFIDENCE IN TAF.
BRIEF VFR POSSIBLE WITH CEILINGS ABOVE 3000 FEET AT TIMES, BUT
MVFR CEILINGS FROM 2000-3000 FEET SHOULD PREVAIL FOR MOST OF THE
TAF PERIOD.
KBDL TERMINAL... HIGH CONFIDENCE IN TAF.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
THURSDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. WINDY
WITH LOCAL GUSTS UP TO 30 KT. SHRA, SLIGHT CHANCE TSRA.
FRIDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. STRONG WINDS WITH
LOCAL GUSTS UP TO 40 KT. CHANCE SHRA.
FRIDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. STRONG
WINDS WITH LOCAL GUSTS UP TO 40 KT. SLIGHT CHANCE SHRA.
SATURDAY: VFR. STRONG WINDS WITH LOCAL GUSTS UP TO 40 KT.
SATURDAY NIGHT: VFR. BREEZY.
SUNDAY:
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT
GALE FORCE NORTHEAST WINDS DEVELOP OVER THE COASTAL MARINE ZONES
SOUTH OF THE ISLANDS. THE STRONG WINDS WILL DEVELOP IN RESPONSE TO A
TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRESSURE OVER CANADA AND
AN AREA OF LOW-PRESSURE MOVING UP THE EAST COAST. ELSEWHERE ACROSS
THE COASTAL WATERS, EXPECT SOLID SCY CONDITIONS WITH 25 TO 30 KNOT
NORTHEAST WIND GUSTS. SEAS INCREASING TO 6 TO 8 FEET OVER THE
EASTERN/OUTER MARINE ZONES. 2-5 FEET OVER THE SOUTH COASTAL NEAR-
SHORE ZONES.
TOMORROW AND TOMORROW NIGHT
THE PRESSURE GRADIENT RELAXES SOMEWHAT TOMORROW ALLOW FOR GRADUALLY
DIMINISHING NORTHEAST WINDS THROUGHOUT THE DAY. DESPITE DECLINING
WIND SPEEDS, WE'RE STILL EXPECTING 20 TO 30 KNOT NORTHEAST GUSTS
THROUGHOUT THE DAY WITH SHOWERS DEVELOPING IN THE AFTERNOON. SEAS
GRADUALLY SUBSIDE BY A FOOT OR TWO AS WELL, BUT REMAIN ELEVATED
BETWEEN 5 AND 8 FEET OVER THE OUTER MARINE ZONES. THESE
CONDITIONS WILL PERSIST THROUGH TOMORROW NIGHT.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
THURSDAY NIGHT: STRONG WINDS WITH LOCAL GUSTS UP TO 30 KT.
ROUGH SEAS UP TO 8 FT. RAIN SHOWERS. VISIBILITY 1 TO 3 NM.
FRIDAY: MODERATE RISK FOR GALE FORCE WINDS WITH LOCAL GUSTS UP
TO 45 KT. ROUGH SEAS UP TO 15 FT. CHANCE OF RAIN SHOWERS.
FRIDAY NIGHT: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH
SEAS UP TO 17 FT. SLIGHT CHANCE OF RAIN SHOWERS.
SATURDAY: MODERATE RISK FOR GALE FORCE WINDS WITH GUSTS UP TO
40 KT. ROUGH SEAS UP TO 17 FT.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
LOCAL GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS.
SUNDAY: 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 8 AM EDT THURSDAY FOR ANZ231>235-
237-250-251-254.
GALE WARNING UNTIL 8 AM EDT THURSDAY FOR ANZ255-256.
SYNOPSIS...BW/RM
NEAR TERM...RM
SHORT TERM...
LONG TERM...BW/RM
AVIATION...MENSCH
MARINE...BW/RM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page