657
FXUS61 KBOX 142320
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
720 PM EDT WED OCT 14 2026
WHAT HAS CHANGED
GALE WATCHES HAVE BEEN ISSUED FOR ALL WATERS DUE TO THE POTENTIAL
FOR STRONG POST-FRONTAL NORTHWEST WIND GUSTS FRIDAY EVENING THROUGH
SATURDAY.
KEY MESSAGES
- ISOLATED SHOWER POSSIBLE THIS AFTERNOON, BUT OTHERWISE MAINLY
DRY AND WARM. DRY THURSDAY WITH SEASONABLY COOL TEMPERATURES.
- FAST-MOVING SYSTEM TO BRING PERIODS OF RAIN FRIDAY, FOLLOWED
BY DRIER AND MUCH COLDER CONDITIONS SATURDAY.
- QUIET AND SEASONABLE WEATHER SUNDAY THROUGH TUESDAY.
DISCUSSION
KEY MESSAGE 1...ISOLATED SHOWER POSSIBLE THIS AFTERNOON, BUT
OTHERWISE MAINLY DRY AND WARM. DRY THURSDAY WITH SEASONABLY COOL
TEMPERATURES.
FOR THE REST OF THE AFTERNOON, EXPECT DRY CONDITIONS OVERALL WITH
THE EXCEPTION OF AN ISOLATED SHOWER THROUGH THE EVENING. TONIGHT
WILL BE DRY WITH MAINLY CLEAR SKIES WITH TEMPERATURES FALLING INTO
THE 40S. COOLER AIR ADVECTS IN FROM THE NORTH OVERNIGHT WHILE
SURFACE HIGH PRESSURE SHIFTS EASTWARD INTO THE REGION. THE TIGHTENED
PRESSURE GRADIENT ALONG WITH STEEPER LAPSE RATES SHOULD SUPPORT SOME
MIXING TO BRING DOWN GUSTS AROUND 20 KTS, PERHAPS A LITTLE STRONGER
FOR THE CAPE WHERE THE GRADIENT IS TIGHTER.
SURFACE HIGH PRESSURE SETTLES OVER SOUTHERN NEW ENGLAND ON THURSDAY.
AS IT BUILDS IN, THE PRESSURE GRADIENT WILL RELAX, ALLOWING WINDS
TO DECREASE THROUGH THE MORNING. LARGE SCALE SUBSIDENCE WILL
MAINTAIN DRY CONDITIONS ALONGSIDE LIGHT NORTHERLY FLOW. A COOLER
AIRMASS WILL BE IN PLACE CHARACTERIZED BY 925MB TEMPERATURES +6-
8(APPROX 10C COOLER THAN WED). THIS WILL BRING A SEASONABLY COOL DAY
WITH HIGH TEMPERATURES IN THE UPPER 50S AND LOW 60S.
KEY MESSAGE 2...FAST-MOVING SYSTEM TO BRING PERIODS OF RAIN FRIDAY,
FOLLOWED BY DRIER AND MUCH COLDER CONDITIONS SATURDAY.
FORECAST TRENDS CONTINUE TO INDICATE A RATHER SOGGY END TO THE WEEK.
THE GOOD NEWS IS THAT THIS IS A FAIRLY PROGRESSIVE SYSTEM, WITH RAIN
CLEARING OUT IN TIME FOR THE WEEKEND. HIGH PRESSURE DRIFTS EAST AND
OFFSHORE OVERNIGHT INTO EARLY FRIDAY. MEANWHILE, TO OUR WEST, A LOW
PRESSURE SYSTEM DEVELOPS ACROSS THE EASTERN GREAT LAKES AND DEEPENS
AS IT TRAVELS NORTHEAST THROUGH THE SAINT LAWRENCE VALLEY. THE LOW
IS EXPECTED TO DEEPEN BY ROUGHLY 10 TO 15 MB WITHIN 24 HOURS,
REACHING AROUND 995 MB BY LATE FRIDAY EVENING. OUT AHEAD OF THE LOW,
A WARM FRONT BRINGS AN INITIAL BAND OF RAIN TO SOUTHERN NEW ENGLAND
DURING THE EARLY MORNING HOURS FRIDAY, BEGINNING DURING THE PREDAWN
HOURS AND SPREADING FROM WEST TO EAST. THERE IS THE POTENTIAL FOR A
LULL IN ACTIVITY BETWEEN LATE MORNING AND EARLY AFTERNOON. WHILE IN
THE WARM SECTOR, ANTICIPATE MILD, MUGGY, AND BREEZY CONDITIONS WITH
SOUTH-SOUTHWESTERLY WINDS. A SECOND ROUND OF SHOWERS, WITH THE
POTENTIAL FOR THUNDER, IS EXPECTED LATE FRIDAY AFTERNOON THROUGH THE
EVENING WITH THE PASSAGE OF A STRONG COLD FRONT. DRIER AND COOLER
CONDITIONS FOLLOW BEGINNING SATURDAY MORNING.
IN TERMS OF PRECIPITATION, PWATS ARE QUITE ELEVATED FOR MID-OCTOBER,
WITH VALUES RANGING BETWEEN 1.5 AND 1.8 INCHES, ROUGHLY 2 TO 3
STANDARD DEVIATIONS ABOVE NORMAL. LOCALLY HEAVY DOWNPOURS ARE
POSSIBLE, THOUGH THE FLOODING THREAT IS MINIMAL CONSIDERING THE
PROGRESSIVE NATURE OF THE SYSTEM. AS MENTIONED, WARM FRONTAL SHOWERS
ARE EXPECTED DURING THE PREDAWN HOURS FRIDAY. THERE WILL BE LESS
LIFT DURING THE DAYTIME; HOWEVER, SPOTTY SHOWERS MAY CONTINUE DUE TO
ONGOING WAA. AS THE SURFACE LOW TRACKS CLOSER TO QUEBEC CITY, A COLD
FRONT BRINGS STRONG FORCING DURING THE LATE AFTERNOON AND EVENING,
WITH A FINAL ROUND OF SHOWERS AND EMBEDDED THUNDERSTORMS. WHILE WE
DO NOT ANTICIPATE WIDESPREAD SEVERE WEATHER, THERE IS A FAIR AMOUNT
OF BULK SHEAR, RANGING FROM 50 TO 80 KNOTS, AND MUCAPE VALUES AROUND
500 J/KG. IT COULD BE ONE OF THOSE DAYS WHERE THE HIGHER SHEAR
COMPENSATES FOR THE RELATIVELY LIMITED INSTABILITY. THIS IS
SOMETHING WE WILL CONTINUE TO MONITOR. AS FOR RAINFALL AMOUNTS,
THERE IS STILL A BIT OF SPREAD AMONG THE GUIDANCE, THOUGH CONSENSUS
IS LEANING TOWARD 0.3 TO 0.8 INCHES. THAT BEING SAID, LOCALLY HIGHER
AMOUNTS ARE POSSIBLE, WITH THE GREATEST POTENTIAL FOR MORE THAN AN
INCH OF RAINFALL ACROSS NORTHWESTERN MASSACHUSETTS, WHERE DESI
PROBABILITIES ARE 15 TO 25 PERCENT.
AS MENTIONED, IT WILL BE BREEZY ON FRIDAY, WITH A 30 TO 40 KNOT LOW-
LEVEL JET. HOWEVER, THE LOW-LEVEL THERMAL INVERSION WILL PLAY A
SIGNIFICANT ROLE IN DETERMINING HOW MUCH OF THAT WIND CAN MIX DOWN
TO THE SURFACE. GIVEN A NEUTRAL INVERSION, DID NOT WANT TO MIX THE
FULL STRENGTH OF THE LOW-LEVEL JET TO THE GROUND. THEREFORE, GUSTS
OF 25 TO 35 MPH ON FRIDAY SEEM THE MOST REASONABLE. BEHIND THE
FRONT, STRONG CAA ALOFT SENDS 850 MB TEMPERATURES FALLING FROM +17C
ON FRIDAY TO -5C ON SATURDAY. WITH STEEP LOW-LEVEL LAPSE RATES,
THERE WILL BE EFFICIENT MIXING THROUGH THE LOWER LEVELS. GUSTS
SATURDAY AFTERNOON MAY APPROACH 30 TO 40 MPH. MIXING MAY BE FURTHER
ENHANCED OVER THE WARMER OCEAN WATERS; THUS, GALE WATCHES HAVE BEEN
ISSUED FOR ALL WATERS FROM FRIDAY EVENING THROUGH SATURDAY EVENING.
WHILE TEMPERATURES WILL BE MILD ON FRIDAY, THE BIGGER STORY WILL BE
THE COLD ON SATURDAY. AS MENTIONED, TEMPERATURES ALOFT WILL BE IN
FREE FALL. HIGHS WILL STRUGGLE TO REACH THE UPPER 40S TO LOWER 50S.
HOWEVER, WHEN FACTORING IN THE WIND, IT WILL LIKELY FEEL AS THOUGH
TEMPERATURES ARE IN THE UPPER 30S TO MIDDLE 40S SATURDAY AFTERNOON.
SATURDAY NIGHT WILL BE QUITE COLD, WITH MANY AREAS FALLING INTO THE
LOWER 30S AND UPPER 20S. THUS, FROST IS POSSIBLE, THOUGH LINGERING
BREEZY CONDITIONS MAY LIMIT ITS DEVELOPMENT. NEVERTHELESS, OUR
FROST/FREEZE PROGRAM HAS ENDED FOR THE GROWING SEASON AS OF OCTOBER
11, AND NO FROST OR FREEZE HEADLINES WILL BE ISSUED.
KEY MESSAGE 3...QUIET AND SEASONABLE WEATHER SUNDAY THROUGH
TUESDAY.
A BROAD AREA OF HIGH PRESSURE BUILDS INTO THE REGION SUNDAY THROUGH
TUESDAY, LEADING TO A PERIOD OF QUIET AND DRY WEATHER. THE STRONGER
WINDS FROM SATURDAY DIMINISH ON SUNDAY AS THE PRESSURE GRADIENT
RELAXES WITH THE RETURN OF HIGH PRESSURE. DURING THIS TIME,
TEMPERATURES BEGIN TO MODERATE AND RETURN TO MORE SEASONABLE LEVELS,
WITH HIGHS IN THE UPPER 50S TO LOWER 60S AND OVERNIGHT LOWS RANGING
FROM THE UPPER 30S TO MIDDLE 40S.
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: HIGH CONFIDENCE.
VFR. GUSTS 20-25 KT FOR MOST DEVELOPING 02-04Z; 20-25 KT GUSTS,
HIGHEST FOR THE CAPE AND ISLAND TERMINALS.
THURSDAY...HIGH CONFIDENCE.
VFR. WINDS DIMINISH 12-15Z FOR MOST TERMINALS WITH HIGH
PRESSURE SETTLING OVERHEAD. GUSTS AROUND 18KTS MAY LINGER
THROUGH 16/17Z FOR HYA/ACK. WINDS NNW SHIFTING TO THE N AT 5-10
KTS. WINDS MAY SHIFT AROUND TO THE NE-E IN THE AFTERNOON/EARLY
EVE FOR THE COASTAL TERMINALS.
THURSDAY NIGHT...MODERATE CONFIDENCE.
MVFR TO IFR WITH -SHRA MOVING IN FROM WEST TO EAST BETWEEN 04Z
AND 10Z. S-SW WINDS DEVELOP WITH GUSTS NEARING 20 KT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...
FRIDAY: MVFR/IFR CONDITIONS POSSIBLE. WINDY WITH AREAS OF GUSTS
UP TO 30 KT. SHRA, PATCHY BR.
FRIDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT. SHRA, PATCHY BR.
SATURDAY: VFR. WINDY WITH GUSTS UP TO 35 KT.
SATURDAY NIGHT THROUGH SUNDAY: VFR. BREEZY.
SUNDAY NIGHT: VFR.
MONDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
SMALL CRAFT ADVISORIES WERE EXTENDED AND/OR HOISTED FOR TONIGHT
FOR THE EASTERN WATERS INTO 18Z THURSDAY AS A PERIOD OF ENHANCED
NW GUSTS OF 25-30 KT ARE EXPECTED TO DEVELOP EARLY TONIGHT. SEAS
AROUND 3-5 FT ON MOST WATERS THROUGH THURSDAY, WITH DRY WEATHER
AND GOOD VISIBILITY EXPECTED. GUSTS SHOULD SUBSIDE BELOW SCA
CRITERION BY THURSDAY NIGHT.
A FRONTAL SYSTEM BRINGS RETURNING SW WINDS INTO THE SCA RANGE ON
FRIDAY (25-30 KT), WHICH WILL ALSO BRING PERIODS OF LIGHT TO
MODERATE RAIN REDUCING VISIBILITY THROUGH FRIDAY EARLY EVENING.
A SHORT PERIOD OF SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
ONCE THE EXISTING SCAS EXPIRING THURSDAY AFTERNOON EXPIRE.
LOOKING AHEAD INTO FRIDAY NIGHT AND INTO SATURDAY...A PERIOD OF
STRONG NORTHWEST WINDS ARE FORECAST. WE'VE ISSUED A GALE WATCH
ON MOST WATERS FOR FRIDAY NIGHT INTO SATURDAY, WITH SEAS
BECOMING INCREASINGLY ROUGH AT UP TO 12 FT. DRY WEATHER IS
EXPECTED BY SATURDAY.
OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...
FRIDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. AREAS OF ROUGH SEAS. RAIN SHOWERS, PATCHY FOG.
FRIDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS
UP TO 12 FT. RAIN SHOWERS LIKELY.
SATURDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS UP TO
12 FT. CHANCE OF RAIN SHOWERS.
SATURDAY NIGHT: STRONG WINDS WITH LOCAL GUSTS UP TO 30 KT.
ROUGH SEAS UP TO 11 FT.
SUNDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
MONDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ230>234-
250-251.
GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY EVENING FOR
ANZ230>237-250-251-254>256-280>283.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ254-255.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ256.
DISCUSSION...DOOLEY/MENSCH
AVIATION...DOOLEY/MENSCH
MARINE...LOCONTO/DOOLEY/MENSCH
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