791
FXUS61 KBOX 082329
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
729 PM EDT WED OCT 8 2025
SYNOPSIS
IN THE WAKE OF A DEPARTING COLD FRONT AN AREA OF HIGH PRESSURE
BUILDS IN FROM THE WEST, BRING DRIER AND COLDER CONDITIONS THROUGH
THE END OF THE WEEK. IN THE WAKE OF A DEPARTING COLD FRONT AN AREA
OF HIGH PRESSURE BUILDS IN FROM THE WEST, BRING DRIER AND COLDER
CONDITIONS THROUGH THE END OF THE EARLY WEEKEND. A COASTAL STORM MAY
BRING SOME RAIN AND GUSTY WINDS TO START NEXT WEEK, ALONG WITH THE
RISK FOR SOME COASTAL FLOODING AND EROSION.
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/
KEY MESSAGES:
* A LINGERING SHOWERS ACROSS CAPE COD AND THE ISLANDS THIS AFTERNOON
AND THEN CLEAR AND CHILLY OVERNIGHT.
THE COLD FRONT WHICH BROUGHT MUCH NEEDED RAIN HAS EXITED THE COAST,
BUT POST FRONTAL SHOWERS CONTINUE ACROSS PORTIONS OF CAPE COD AND
THE NEIGHBORING ISLANDS FOR THE NEXT FEW HOURS. THE REST OF THE DAY
IS BREEZY AND COOL, HIGHS OCCURRED EARLY TODAY AS TEMPERATURES ARE
FOLLOWING A NON-DIURNAL TREND. IN FACT, MANY PLACES THIS AFTERNOON
ARE IN THE 50S, WHICH IS ABOUT AS COLD AS WE WERE THE LAST COUPLE OF
NIGHTS. OVERNIGHT, THE MID-LEVEL TROUGH SLIDES EAST AND 1035MB HIGH
BUILD ACROSS THE NORTHERN GREAT LAKES WITH CLEARING SKIES AND NORTH-
NORTHWESTERLY FLOW. IT WILL BE CHILLY, LOWERING INTO THE LOW-40S AND
UPPER-30S. WOULD NOT BE SURPRISED IF THE HIGH ELEVATION COMMUNITIES
IN NORTHWESTERN MA (AOA 1,500 FT) DIP DOWN TO THE FREEZING MARK.
SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/
KEY MESSAGES:
* A CHILLY DAY AHEAD, TURNING COLD OVERNIGHT WITH AN EXPANSION OF
THE FREEZE WATCH.
INCREASING MID-LEVEL HEIGHTS AND 1035MB HIGH PRESSURE SHIFTS TO THE
NORTHEAST. ATMOSPHERIC PROFILE IS VERY DRY, PWATS LOWERING TO 0.2",
WHICH IS 30% OF NORMAL, THUS EXPECTING MOSTLY CLEAR SKIES. 925MB
TEMPERATURES ARE SIGNIFICANTLY COOLER, +2C TO +4C, SUPPORTIVE OF
HIGHS IN THE MIDDLE TO UPPER-50S. REMAINING BREEZY WITH WINDS FROM
THE NORTH-NORTHWEST, GUSTING 15 TO 20MPH.
HIGH PRESSURE IS CENTERED OVERHEAD OVERNIGHT THROUGH FRIDAY MORNING.
AS WE KNOW, CLEAR SKIES AND LIGHT WIND ARE THE PERFECT RECIPE FOR
RADIATIONAL COOLING. DID DEVIATE AWAY FROM THE NBM, USED A BLEND OF
COLDER GUIDANCE SOURCES TO DERIVE OVERNIGHT TEMPERATURES IN THE
UPPER-20S TO LOWER-30S. AT THE IMMEDIATE COAST AND THE URBAN CORE OF
BOSTON, WOULD EXPECT LOWS FROM THE MIDDLE TO UPPER-30S. DID EXPAND
THE FREEZE WATCH DURING THIS UPDATE TO INCLUDE ALL OF RHODE ISLAND
WITH THE EXCEPTION OF BLOCK ISLAND AND OPT'D TO INCLUDE THE
VINEYARD. THE FREEZE WATCH FOR MARTHA'S VINEYARD IS PRIMARILY A
CONCERN FOR INTERIOR SECTIONS OF THE ISLAND. THESE AREAS COOL OFF
MORE EFFICIENTLY AT NIGHT THAN NEAR THE COAST, SINCE THE SURROUNDING
OCEAN RETAINS WARMTH AND KEEPS COASTAL TEMPERATURES A FEW DEGREES
HIGHER. IN CONTRAST, THE ISLAND'S INTERIOR IS FATHER FROM THE
MODERATING INFLUENCE OF THE OCEAN, ALLOWING HEAT TO ESCAPE MORE
RAPIDLY IMPART DUE TO THE SANDY SOIL COMPOSITION, IN ADDITION TO THE
FACTORS OF ALREADY MENTIONED; THE CLEAR SKIES, LIGHT WINDS, WHICH ARE
IDEAL CONDITIONS FOR FROST FORMATION.
IF CONFIDENCE INCREASES, AREAS UNDER A WATCH COULD BE CONVERTED TO A
WARNING OR OVER TO A FROST ADVISORY DURING SUBSEQUENT FORECAST
UPDATES.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
KEY MESSAGES:
* QUIET AND DRY THROUGH THE END OF THE WEEK
* SLIGHTLY WARMER SATURDAY BEFORE HIGHS RETURN TO THE LOW 60S
* COASTAL STORM MAY BRING SOME RAIN AND GUSTY WINDS TO START NEXT
WEEK, ALONG WITH THE RISK FOR SOME COASTAL FLOODING AND EROSION
HIGH PRESSURE CENTERED OVER SOUTHERN NEW ENGLAND WILL KEEP
CONDITIONS DRY WITH CLEAR SKIES FRIDAY. WINDS BECOME LIGHTER AND
SHIFT MORE TO THE SOUTH/SOUTHWEST, BRINGING IN MORE MILD AIR. HIGH
TEMPERATURES INTO THE LOW 60S WILL BE SUPPORTED UNDER THESE
CONDITIONS: 925 MB TEMPERATURES START TO APPROACH 10C ONCE AGAIN.
THIS SURFACE HIGH PRESSURE ALONG WITH AN UPPER LEVEL TROUGH TO OUR
EAST WILL SHIFT OUT TO SEA GOING INTO SATURDAY, THOUGH 925 MB
TEMPERATURES ACROSS MUCH OF THE GUIDANCE THEN REBOUNDS SOUNDLY TO
AROUND 10C AND HIGHER IN SOME SPOTS. HIGH TEMPERATURES SATURDAY WILL
LIKELY BE THE WARMEST OF THE WEEKEND, REACHING THE MID TO UPPER 60S
ACROSS THE REGION. SOME HIGHER CLOUDS START TO MOVE IN SATURDAY AS
WELL ASSOCIATED WITH A COASTAL STORM THAT WILL CONTINUE TO FORM WELL
TO OUR SOUTH.
SOME UNCERTAINTY REMAINS REGARDING THE START OF NEXT WEEK. A COASTAL
STORM MOVING NORTH ALONG THE SOUTHEAST AND MID-ATLANTIC COASTS WILL
MAKE ITS WAY TOWARDS SOUTHERN NEW ENGLAND SOMETIME EARLY MONDAY/LATE
SUNDAY. SIMULTANEOUSLY, STRONG HIGH PRESSURE IS EXPECTED TO BE
SETTLED OVER PARTS OF THE CANADIAN MARITIMES, QUEBEC AND MAINE. THE
PRESSURE GRADIENT BETWEEN THIS HIGH AND THE COASTAL STORM TO THE
SOUTH WILL BE CONDUCIVE TO STRONG, GUSTY NORTHEAST WINDS AND ROUGHER
SEAS. DEPENDING ON HOW FAR NORTH IT TRACKS, WE MAY ALSO SEE SOME
MORE RAIN. GLOBAL GUIDANCE HAS STARTED TO FIND SOME AGREEMENT
REGARDING RAINFALL OVER THE REGION, THOUGH TOTALS ARE STILL TO BE
DETERMINED. THE GREATEST CHANCES FOR RAIN REMAIN OVER THE SOUTH
COAST AND ISLANDS. CONFIDENCE REMAINS LOW REGARDING HOW QUICKLY THIS
LOW WILL EXIT THE REGION: CANADIAN MODEL GUIDANCE (BOTH ENSEMBLE AND
DETERMINISTIC) HAS IT STALLING OVER THE WATERS TO OUR SOUTH, WHICH
WOULD BE MORE OF A WORST-CASE SCENARIO. SEAS WOULD CONTINUE TO BUILD
AFTER THE KING TIDES HAVE PASSED AND THE RISK FOR COASTAL EROSION
AND FLOODING WOULD INCREASE, THOUGH THIS RISK DOES REMAIN MINOR AT
THIS TIME. GFS GUIDANCE REMAINS PROGRESSIVE, KICKING THE STORM OUT
TO SEA BY TUESDAY, AND ECMWF GUIDANCE FALLS SOMEWHAT BETWEEN THESE
TWO SCENARIOS. ONCE THIS STORM MAKES ITS EXIT, WINDS WILL SLACKEN AS
THE GRADIENT WEAKENS AND SEAS WILL DECREASE. THE TRACK OF THIS
SYSTEM SHOULD BECOME CLEARER AS WE GET CLOSER TO THIS PERIOD.
AVIATION /00Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
00Z TAF UPDATE:
TONIGHT AND THURSDAY...HIGH CONFIDENCE.
VFR. NW WINDS 8-12 KTS WITH GUSTS 20 KNOTS. GUSTS OF 20 TO 30
KNOTS TOWARD THE CAPE AND NANTUCKET.
THURSDAY NIGHT...HIGH CONFIDENCE.
VFR. WINDS DIMINISH GREATLY WITH GUSTS FALLING OFF A LITTLE
BEFORE 00Z AND SUSTAINED WINDS BECOMING LIGHT TO CALM.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH SATURDAY: VFR.
SATURDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA.
SUNDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH GUSTS
UP TO 35 KT. CHANCE SHRA.
SUNDAY NIGHT THROUGH COLUMBUS DAY: MAINLY VFR, WITH AREAS MVFR
POSSIBLE. WINDY WITH GUSTS UP TO 35 KT. CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH THURSDAY NIGHT... HIGH CONFIDENCE.
COLD FRONT PUSHES EAST OF THE COASTAL WATERS WITH HIGH PRESSURE OVER
THE NORTHERN GREAT LAKES. GUSTY NORTH-NORTHWEST WINDS AND ROUGH SEAS
FOR OCEAN WATERS WILL LEAD TO A CONTINUED SMALL CRAFT ADVISORY. WILL
HAVE IMPROVING CONDITIONS THURSDAY AFTERNOON WITH EASING WINDS AND
FALLING SEAS, THIS COMES AS HIGH PRESSURE SETTLES OVER THE
REGION.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH SATURDAY: WINDS LESS THAN 25 KT.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
SUNDAY: LOW RISK FOR GALE FORCE WINDS WITH GUSTS UP TO 40 KT.
AREAS OF ROUGH SEAS. CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT: GALE FORCE WINDS WITH LOCAL GUSTS UP TO 45 KT.
ROUGH SEAS UP TO 17 FT. RAIN SHOWERS LIKELY, SLIGHT CHANCE OF
THUNDERSTORMS.
COLUMBUS DAY: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH
SEAS UP TO 19 FT. CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...FREEZE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
CTZ002>004.
MA...FREEZE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
MAZ005-009>014-017-018-020-021-023.
RI...FREEZE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
RIZ001>007.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THURSDAY FOR ANZ230>235-
237-251.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THURSDAY FOR ANZ250-
254>256.
SYNOPSIS...DOOLEY/HRENCECIN
NEAR TERM...DOOLEY
SHORT TERM...DOOLEY
LONG TERM...HRENCECIN
AVIATION...DOOLEY/HRENCECIN
MARINE...DOOLEY/HRENCECIN
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