385
FXUS61 KBOX 290847
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
447 AM EDT WED OCT 29 2025
SYNOPSIS
CANADIAN HIGH PRESSURE WILL RESULT IN COOL TEMPERATURES THROUGH
TOMORROW NIGHT WITH WIDELY SCATTERED OCEAN-EFFECT SHOWERS POSSIBLE,
MAINLY NEAR AND SOUTHEAST OF I-95. A STRONG LOW PRESSURE
SYSTEM WILL BRING A PERIOD OF MODERATE-HEAVY WINDSWEPT RAIN FOR
SOUTHERN NEW ENGLAND LATER THURSDAY AND THURSDAY NIGHT. GRADUAL
DRYING EARLY FRIDAY MORNING FOLLOWED BY A PERIOD OF GUSTY WINDS
FRIDAY INTO SATURDAY. TEMPERATURES AT OR SLIGHTLY BELOW NORMAL.
NEAR TERM /TODAY/
KEY MESSAGES:
* COOLER TEMPERATURES CONTINUE WITH SCATTERED OCEAN-EFFECT
SHOWERS MAINLY NEAR/SOUTHEAST I-95.
DETAILS...
ANOTHER DAY OF SURFACE HIGH PRESSURE IN SOUTHERN NEW ENGLAND
WITH A SURFACE HIGH POSITIONED OVER QUEBEC. THIS WILL SUPPORT
SIMILAR CONDITIONS TO TUESDAY AS STEADY, COOL NORTHEAST FLOW
WILL KEEP A PERSISTENT CLOUD DECK OVER THE REGION TODAY. CAN'T
RULE OUT A FEW OCEAN-EFFECT SHOWERS, MAINLY NEAR/SOUTHEAST OF
I-95. MOISTURE SUBTLY INCREASES OVER THE REGION TOWARD THE
AFTERNOON, BUT ANY SHOWERS ARE MORE LIKELY TO BE WIDELY
SCATTERED IN COVERAGE WITH LIGHT ACCUMULATION IF ANY. IT WILL
STILL REMAIN BREEZY ACROSS EAST/SOUTHEAST SOUTHERN NEW ENGLAND
WITH GUSTS UP TO 20 MPH IN EASTERN MA AND CLOSER TO 20-30 MPH
FOR THE CAPE/ISLANDS. HIGH TEMPERATURES WILL LIKELY RANGE IN THE
LOW TO MID 50S WITH A FEW UPPER 40S FOR THE HIGHER ELEVATION
SPOTS OF THE INTERIOR.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
KEY MESSAGES:
* A SYSTEM WILL BRING A PERIOD OF MODERATE TO HEAVY RAINFALL AND
GUSTY WINDS LATER THURSDAY AND THURSDAY NIGHT.
* SOME ISOLATED NUISANCE STREET FLOODING POSSIBLE, EXACERBATED
BY ABUNDANCE OF FALLEN LEAVES.
DETAILS...
TONIGHT:
OVERALL QUIET OVERNIGHT PERIOD. NORTHEAST WINDS/GUSTS GRADUALLY
DECREASE INTO THE EARLY EVENING, SLOWER TO WEAKEN IN SOUTHEAST
MA. MOISTURE INCREASES THROUGH THE NIGHT AS A PLUME OF ABOVE
NORMAL (150-200%) ADVECTS IN FROM THE SOUTH OVERNIGHT. THIS WILL
DEEPEN MOISTURE THROUGH THE NIGHT. MODEL GUIDANCE DOESN'T
INDICATE ANY SUBSTANTIAL CHANCES FOR SHOWERS, BUT CAN'T RULE OUT
A FEW SHOWERS ESPECIALLY BY THURSDAY AM. LOW TEMPERATURES DROP
INTO THE MID-30S TO LOW 40S FOR THE INTERIOR AND MID-40S FOR
COASTAL/NEAR-COASTAL AREAS.
THURSDAY-THURSDAY NIGHT:
NO MAJOR CHANGES AMONG ENSEMBLE/DETERMINISTIC GUIDANCE IN
REGARDS TO A STORM SYSTEM THAT WILL BRING A PERIOD OF MODERATE
TO BRIEF HEAVY RAINFALL ACROSS SOUTHERN NEW ENGLAND
THURSDAY/THURSDAY NIGHT. GUIDANCE STILL DEPICTS A DIGGING MID-
LEVEL TROUGH WITH AN ASSOCIATED UPPER LOW BECOMING NEGATIVELY
TILED, LIFTING NORTHWARD ACROSS THE MID-ATLANTIC AND INTO THE
EASTERN GREAT LAKES. AN ASSOCIATED SURFACE LOW SHOULD ALSO
DEEPEN AS IT TRACKS NORTHWARD. ALTHOUGH, THE ENVELOPE OF
ENSEMBLE MEMBERS SHOW THAT THERE IS STILL SOME UNCERTAINTY IN
THE LOW TRACK WITH ALSO QUESTION IN IF THERE WILL BE SECONDARY
LOW DEVELOPMENT.
THE INCOMING TROUGH AND ACCOMPANYING UPPER JET WILL PROVIDE
LARGE-SCALE LIFT ACROSS THE REGION WITH A PLUME OF ABOVE NORMAL
MOISTURE ADVECTING INTO THE REGION WITHIN THE SW FLOW ALOFT.
THIS WILL SUPPORT WIDESPREAD MODERATE RAINFALL ACROSS THE
REGION, POTENTIALLY HEAVY AT TIMES. FOR TIMING, CONFIDENCE IS
MODERATE AS THERE IS SOME VARIATION AMONG MODEL GUIDANCE ON
EXACT TIMING. MOST GUIDANCE HAS THE MAIN BULK OF RAIN ARRIVING
IN THE MID AFTERNOON TO EARLY EVENING THURSDAY TIMEFRAME. A FEW
SHOWERS ARE POSSIBLE DURING THE DAY. RAIN CONTINUES THURSDAY
NIGHT WITH POCKETS OF HEAVY RAINFALL POSSIBLE. ENSEMBLES SHOW A
RANGE OF MOST LIKELY AMOUNTS FROM 0.75-2.0", WITH SOME HIGHER
MEMBERS SHOWING LOCALIZED 2.5-3.0". THE LOCATION OF THE HEAVIER
AMOUNTS WILL DEPEND ON THE TRACK OF THE LOW, WITH GUIDANCE
HIGHLIGHT THE CAPE/ISLANDS AS MORE LIKELY TO RECEIVE AMOUNTS
1-2"+ AMOUNTS. GIVEN THE PROGRESSIVE NATURE OF THIS SYSTEM,
FLASH FLOODING IS NOT LIKELY, ALTHOUGH SOME LOCALIZED NUISANCE
FLOODING IN POOR DRAINAGE/LOW LYING AREAS IS POSSIBLE. FALLEN
LEAVES THIS TIME OF YEAR MAY POTENTIALLY EXACERBATE THE NUISANCE
FLOODING DUE TO CLOGGING OF STORM DRAINS. IT WILL BE FAIRLY
BREEZY WITH EAST/NORTHEAST WINDS EXPECTED WITH GUSTS 20-35 MPH,
POTENTIALLY UP TO 40 MPH FOR THE CAPE/ISLANDS.
LONG TERM /FRIDAY THROUGH TUESDAY/
DETAILS...
KEY MESSAGES...
* GUSTY WINDS DEVELOP FRIDAY WITH GUSTS POTENTIALLY UP TO 40 MPH
FOR HIGHER TERRAIN AND COASTAL AREAS.
DETAILS...
THE DRY SLOT ASSOCIATED WITH THE SYSTEM PUSHES INTO THE REGION
EARLY FRIDAY MORNING DECREASING SHOWERS. THINGS WON'T COMPLETELY
DRY OUT AS THERE WILL LIKELY BE WRAP AROUND MOISTURE AROUND THE
LOW SHIFTING ACROSS THE REGION FRIDAY. IT SHOULD STAY MAINLY DRY
WITH ONLY A POP UP SHOWER OR TWO WITH THE COLD POOL OVERHEAD.
THE BIGGEST CONCERN FOR IMPACTS WILL BE THE GUSTY WINDS. THE
EXITING DEEP LOW WILL SUPPLY A SUFFICIENT PRESSURE
DIFFERENTIAL/GRADIENT ACROSS SOUTHERN NEW ENGLAND. A 45-55 KT
LLJ POSITIONS ACROSS THE REGION WITH COLD ADVECTION WHICH WILL
HELP PROVIDE MORE EFFICIENT MEANS OF MIXING DOWN THE STRONGER
WINDS TO THE SURFACE. ENSEMBLES SHOW POTENTIAL FOR GUSTS 30-40
MPH FRIDAY AFTERNOON AND EVENING. THIS SEEMS TO MATCH WHAT MODEL
SOUNDINGS SHOW. THE MAX GUSTS WILL BE A MATTER OF HOW DEEP WE
CAN MIX AND LIKELY STEMMING FROM THE STRENGTH OF THE COLD
ADVECTION. THE EAST SLOPE OF THE BERKSHIRES WILL BE FAVORED FOR
HIGHER GUSTS WITH WESTERLY COMPONENT FLOW EVEN PROVIDING
DOWNSLOPE ENHANCEMENTS AS WELL. COASTAL AREAS SUCH AS THE CAPE
MAY ALSO BE AT RISK FOR HIGHER GUSTS 35-40 MPH. WIND HEADLINES
MAY BE NEEDED FRIDAY AND/OR FRIDAY NIGHT.
THE PRESSURE GRADIENT RELAXES A BIT SATURDAY REDUCING THE RISK
FOR STRONG WINDS/GUSTS; HOWEVER, IT WILL STILL BE WINDY ON
SATURDAY. WINDS BECOME LIGHTER SUNDAY AS THE PRESSURE GRADIENT
RELAXES EVEN FURTHER. DRY CONDITIONS ARE EXPECTED WITH
TEMPERATURES SLIGHTLY BELOW NORMAL WITH HIGHS IN THE LOW TO MID
50S. WEAK MID-LEVEL RIDGING CONTINUES INTO EARLY NEXT WEEK
KEEPING CONDITIONS MAINLY DRY. CONFIDENCE DECREASES IN THE
PATTERN TOWARD MID-WEEK WITH REGARD TO A WEAK SYSTEM MOVING
THROUGH SOMETIME TUE/WED BRINGING THE NEXT SHOT FOR SHOWERS.
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 /FRIDAY THROUGH SUNDAY/...
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.
SATURDAY: VFR. STRONG WINDS WITH LOCAL GUSTS UP TO 40 KT.
SATURDAY NIGHT: VFR. BREEZY.
SUNDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY AND TONIGHT:
THE PRESSURE GRADIENT RELAXES RELATIVE TO TUESDAY NIGHT. THIS
WILL GRADUALLY DIMINISH NORTHEAST WINDS THROUGHOUT THE DAY.
DESPITE DECLINING WIND SPEEDS, WE'RE STILL EXPECTING 20 TO 30
KNOT NORTHEAST GUSTS THROUGHOUT THE DAY WITH OCEAN-EFFECT
SHOWERS POSSIBLE. SEAS GRADUALLY SUBSIDE BY A FOOT OR TWO AS
WELL, BUT REMAIN ELEVATED BETWEEN 5 AND 9 FEET OVER THE OUTER
MARINE ZONES. THESE CONDITIONS WILL PERSIST THROUGH TOMORROW
NIGHT.
OUTLOOK /FRIDAY THROUGH SUNDAY/...
FRIDAY: MODERATE RISK FOR GALE FORCE WINDS WITH LOCAL GUSTS UP
TO 45 KT. ROUGH SEAS UP TO 17 FT. SLIGHT CHANCE OF RAIN
SHOWERS.
FRIDAY NIGHT: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH
SEAS UP TO 18 FT.
SATURDAY: MODERATE RISK FOR GALE FORCE WINDS WITH GUSTS UP TO
40 KT. ROUGH SEAS UP TO 16 FT.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
LOCAL GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.
SUNDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
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...MENSCH
NEAR TERM...MENSCH
SHORT TERM...MENSCH
LONG TERM...BW
AVIATION...MENSCH
MARINE...MENSCH
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