483
FXUS61 KBOX 261909
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
309 PM EDT SUN OCT 26 2025
SYNOPSIS
CANADIAN HIGH PRESSURE WILL KEEP COOL CONDITIONS AROUND FOR THE
START OF THE WORK WEEK, WITH MAINLY DRY WEATHER TONIGHT AND
TOMORROW. AS THIS HIGH SHIFTS FURTHER EAST ACROSS
QUEBEC...ONSHORE FLOW MAY BRING SOME SCATTERED SHOWERS MAINLY
NEAR THE COAST ON TUESDAY AND WEDNESDAY. A LOW PRESSURE SYSTEM
MAY BRING A PERIOD OF RAIN AND GUSTY WINDS SOMETIME THURSDAY
INTO FRIDAY, BUT OVERALL IMPACTS LOOK TO BE ON THE MINOR SIDE AT
THIS POINT.
NEAR TERM /THROUGH TONIGHT/
UPPER-LEVEL COLD POOL REMAINS PARKED OVER THE GULF OF MAINE
OVERNIGHT, WITH WEAK SUBSIDENCE FROM NVA OVER SNE. SKIES ARE
EXPECTED TO REMAIN CLEAR OVERNIGHT, WITH LITTLE TO NO WIND. WITH
GREAT RADIATIONAL COOLING CONDITIONS AND TOO COLD AN AIR MASS
ALREADY IN PLACE, OVERNIGHT LOWS WILL TUMBLE INTO THE UPPER 20S TO
LOW 30S AWAY FROM URBAN AREAS AND THE COASTS.
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
STALLED UPPER-LEVEL COLD POOL SENDS SOME WEAK SHORTWAVE ENERGY ALONG
WITH A REINFORCING SHOT OF COLD AIR ADVECTION INTO THE REGION FOR
TOMORROW. 850MB TEMPS DROP SLIGHTLY TO -5C, WHICH, COMBINED WITH A
MORE NORTHERLY WIND AND CHILLY START, HIGH TEMPS WILL BE A FEW
DEGREES COOLER THAN TODAY, IN THE UPPER 40S TO LOW 50S. SKIES TURN
PARTLY TO MOSTLY CLOUDY TOMORROW AS STRATOCUMULUS FORMS, ESPECIALLY
NEAR THE EASTERN WATERS.
CHILLY AGAIN OVERNIGHT MONDAY INTO TUESDAY AS WINDS BECOME LIGHT.
LOWS WILL AGAIN DROP INTO THE UPPER 20S TO LOW 30S AWAY FROM URBAN
AREAS AND THE COASTS. THERE COULD BE ISOLATED OCEAN EFFECT SHOWERS
NEAR THE CAPE AND ISLANDS OVERNIGHT AS NORTHERLY WINDS BEGIN TO
INCREASE.
LONG TERM /TUESDAY THROUGH SUNDAY/
KEY MESSAGES:
* COOLER TEMPERATURES WITH BREEZY NORTHEAST WINDS THROUGH WEDNESDAY.
* NEXT CHANCE FOR WIDESPREAD RAIN LATE IN THE WEEK, THOUGH THERE IS
UNCERTAINTY WITH EXACT DETAILS.
IT'S HARD TO BELIEVE, BUT HERE COMES THE FINAL WEEK OF OCTOBER AND
THIS COMING WEEK FEATURES PERIODS OF UNSETTLED CONDITIONS. LET'S GET
INTO THE OVERALL DETAILS.
TUESDAY AND WEDNESDAY:
1030+ HPA AREA OF HIGH PRESSURE REMAINS ANCHORED ACROSS EASTERN
CANADA TUESDAY INTO EARLY THURSDAY, BEFORE WEAKENING. ON TUESDAY, A
SOUTHERN STREAM SHORTWAVE AND LOW PRESSURE EXITS OFF THE SOUTHEAST
COAST AND HEADS NORTHEAST TOWARDS BERMUDA AND THEN OUT INTO THE
NORTH ATLANTIC. RESULTING PRESSURE GRADIENT ACROSS SOUTHERN NEW
ENGLAND FAVORS NORTHEAST FLOW, COMING OFF THE GULF OF MAINE, WITH
SST AROUND THE MID-50S. COMBINED WITH A MID-LEVEL LOW AND COLD POOL,
WILL HAVE BELOW NORMAL TEMPERATURES BETWEEN THE LOW AND MID-50S AT
THE COASTAL AND UPPER-40S ACROSS HIGHER TERRAIN OF NORTHERN AND
WESTERN MASSACHUSETTS. NIGHTTIME LOWS ARE SEASONABLY COOL IN THE 30S
AND MIDDLE-40S AT THE COAST.
ORIENTATION OF THE FLOW CAN RESULT IN OCEAN EFFECT CLOUDS AND/OR
SHOWER ACTIVITY. MODERATE CONFIDENCE IN THIS, WHICH WOULD AFFECT
MAINLY EASTERN MASSACHUSETTS; CAPE ANN, CAPE COD, AND THE ISLANDS.
DID OPT TO CAP POPS AT 'SLIGHT CHANCE' AS PWATS ARE LOW, LESS THAN
80% OF AVERAGE, THESE WOULD BE MORE OF SPRINKLES OR LIGHT RAIN.
THURSDAY AND FRIDAY:
ROUNDING OUT THE WEEK BRINGS OUR NEXT CHANCE OF APPRECIABLE RAINFALL
TO SOUTHERN NEW ENGLAND, BUT THERE REMAINS UNCERTAINTY WITH OVERALL
TIMING DURING THIS FORECAST PERIOD. WEDNESDAY NIGHT INTO THURSDAY A
POWERFUL SHORTWAVE EJECTS FROM THE ROCKIES, DIVES SOUTH TO THE GULF
COAST, AND ABSORBS THE EXISTING SHORTWAVE THAT WAS OVER NEW ENGLAND.
AT SURFACE LEVEL, LOW PRESSURE DEVELOPS AND STRENGTHENS QUICKLY AS
IT RACES FROM THE SOUTHEASTERN CONUS TO THE NORTHEASTERN CONUS. WILL
SAY, THE ENSEMBLE SPREAD IN THE POSITION OF THIS LOW IS VAST, HENCE
THE LEVEL OF UNCERTAINTY WITH THIS PERIOD OF THE FORECAST. ANOTHER
FEATURE THAT COULD INFLUENCE IS T.C. MELISSA. OFFICIAL FORECAST FROM
NHC WOULD BRING MELISSA NEAR BERMUDA EARLY FRIDAY, WILL HAVE TO SEE
OF THE SYSTEM TO THE WEST INTERACTS WITH THE T.C. AS THERE ARE SIGNS
SOME OF THE TROPICAL MOISTURE MAY ADVECT NORTH AND ENHANCE RAINFALL.
IT'S TOO EARLY TO SPECULATE ON HOW MUCH RAIN, BUT SIGNALS ARE THERE
FOR SOAKING RAIN SOMETIME LATE THURSDAY INTO FRIDAY. PWATS SURGE AND
REACH 2-3 STANDARD DEVIATIONS ABOVE NORMAL, POTENTIALLY INFLUENCED
BY MELISSA'S TROPICAL ORIGINS. THE PROBABILITY OF AT LEAST 1.0" FROM
THURSDAY NIGHT INTO FRIDAY NIGHT ARE 60 TO 80%. WITH 30 TO 50%
PROBABILITIES OF AT LEAST 2.0". DAY 5 MRGL ERO FOR PARTS OF SOUTHERN
NEW ENGLAND HAVE BEEN ISSUED AS A RESULT.
GIVEN INHERENT UNCERTAINTIES WITH T.C. THIS FAR OUT, THERE IS A LOT
OF TIME FOR ADJUSTMENTS TO THE FORECAST. SIDE NOTE: GIVEN FALL LEAF
LITTER IN STORM DRAINS, BEING PROACTIVE AND REMOVING THE LEAF LITTER
CAN REDUCE THE RISK OF POOR DRAINAGE FLOODING... WHICH BY DEFINITION
IS NOT FLASH FLOODING.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT...HIGH CONFIDENCE.
VFR WITH NW WINDS AROUND 5-10 KNOTS. CHANCE FOR PATCHY RADIATION
FOG IN LOW LYING AREAS.
MONDAY...HIGH CONFIDENCE
VFR WITH PERIODS OF MVFR POSSIBLE NEAR THE CAPE AND ISLANDS IN
THE AFTERNOON. NORTH WINDS AT 5-10 KNOTS.
MONDAY NIGHT...HIGH CONFIDENCE
VFR EXCEPT FOR MVFR NEAR THE CAPE AND ISLANDS. OCEAN EFFECT
SHOWERS POSSIBLE NEAR THE CAPE AND ISLANDS. WINDS REMAIN LIGHT
FROM THE NORTH.
KBOS TERMINAL... HIGH CONFIDENCE IN TAF.
VFR. NW WINDS AROUND 10 KNOTS TODAY
KBDL TERMINAL... HIGH CONFIDENCE IN TAF.
VFR. LIGHT N WINDS UNDER 10 KNOTS TODAY.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY. CHANCE
SHRA.
TUESDAY NIGHT THROUGH WEDNESDAY: MAINLY VFR, WITH AREAS MVFR
POSSIBLE. BREEZY. CHANCE SHRA.
WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
SLIGHT CHANCE SHRA.
THURSDAY: VFR. BREEZY. CHANCE SHRA.
THURSDAY NIGHT: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. WINDY
WITH LOCAL GUSTS UP TO 30 KT. CHANCE SHRA.
FRIDAY: MVFR/IFR CONDITIONS POSSIBLE. WINDY WITH AREAS OF GUSTS
UP TO 30 KT. CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT THROUGH MONDAY NIGHT...HIGH CONFIDENCE.
NW WINDS BEGIN TO SHIFT MORE NORTHERLY ON MONDAY, REMAINING AROUND
10-15 KNOTS WITH 2-4 FOOT SEAS. WINDS REMAIN NORTH MONDAY NIGHT,
BUT BEGIN TO INCREASE TO 20-25 KNOTS BY DAYBREAK TUESDAY. SEAS
REMAIN 2-4 FEET OVERNIGHT.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
LOCAL GUSTS UP TO 30 KT. SEAS UP TO 5 FT. CHANCE OF RAIN
SHOWERS.
TUESDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 30 KT. ROUGH SEAS
UP TO 10 FT. CHANCE OF RAIN SHOWERS.
WEDNESDAY: STRONG WINDS WITH LOCAL GUSTS UP TO 30 KT. ROUGH
SEAS UP TO 11 FT. CHANCE OF RAIN SHOWERS.
WEDNESDAY NIGHT THROUGH THURSDAY: LOW RISK FOR SMALL CRAFT
ADVISORY WINDS WITH GUSTS UP TO 25 KT. ROUGH SEAS UP TO 11 FT.
CHANCE OF RAIN SHOWERS.
THURSDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS
UP TO 13 FT. RAIN SHOWERS LIKELY.
FRIDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS UP TO
13 FT. RAIN SHOWERS LIKELY. LOCAL VISIBILITY 1 TO 3 NM.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
SYNOPSIS...DOOLEY/KP
NEAR TERM...KP
SHORT TERM...KP
LONG TERM...DOOLEY
AVIATION...DOOLEY/KP
MARINE...DOOLEY/KP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page