431
FXUS61 KBOX 080458
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1258 AM EDT THU OCT 8 2026
WHAT HAS CHANGED
SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR MANY OF OUR COASTAL
WATERS TONIGHT INTO THURSDAY.
KEY MESSAGES
- TEMPS CONTINUE TO MODERATE THU WITH HIGHS REACHING INTO THE
LOWER-MIDDLE 70S IN MANY LOCATIONS. MAINLY DRY WEATHER CONTINUES
WITH A FEW BRIEF SPOT SHOWERS POSSIBLE WITH A COLD FRONT.
- DRY WEATHER PREVAILS FRIDAY THROUGH EARLY SUNDAY, WITH ANOTHER
FROSTY START POSSIBLE SATURDAY. RAIN IS INCREASINGLY LIKELY
LATE SUNDAY INTO COLUMBUS DAY, THOUGH UNCERTAINTY REMAINS WITH
ONSET TIMING AND RAINFALL AMOUNTS.
DISCUSSION
KEY MESSAGE 1...TEMPS CONTINUE TO MODERATE THU WITH HIGHS REACHING
INTO THE LOWER-MIDDLE 70S IN MANY LOCATIONS. MAINLY DRY WEATHER
CONTINUES WITH A FEW BRIEF SPOT SHOWERS POSSIBLE WITH A COLD FRONT.
HIGH PRESSURE WILL CONTINUE TO SHIFT EAST OF THE REGION TONIGHT AS A
COLD FRONT APPROACHES FROM THE WEST ON THURSDAY. A MODEST SOUTHWEST
LLJ AHEAD OF THIS COLD FRONT SHOULD KEEP MOST LOCATIONS FROM
DECOUPLING TONIGHT. THIS WILL RESULT IN A MUCH MILDER NIGHT THAN
WHAT WE SAW LAST NIGHT. OVERNIGHT LOW TEMPS SHOULD ONLY DROP INTO
THE MIDDLE 40S TO THE LOWER 50S IN MOST LOCATIONS WITH MIDDLE 50S IN
THE URBAN HEAT ISLAND OF BOSTON.
A MOISTURE STARVED COLD FRONT AND ASSOCIATED PRE-FRONTAL TROUGH WILL
BE APPROACHING THE AREA FROM THE WEST NEAR DAYBREAK THU. THIS WILL
RESULT IN A PERIOD OF MID-LEVEL CLOUDINESS AND A FEW BRIEF PASSING
SHOWERS POSSIBLE...MAINLY THU MORNING. HOWEVER...ANY SHOWERS WILL BE
VERY SHORT-LIVED IN A GIVEN LOCATION AND PRETTY MUCH LOOKING AT A
DRY DAY. OTHERWISE...PARTIAL SUNSHINE WITH 925T AROUND +14C SHOULD
RESULT IN HIGH TEMPS MAINLY IN THE LOWER TO MIDDLE 70S IN MANY
LOCATIONS. THERE IS A LOW RISK FOR A FEW ADDITIONAL SPOT SHOWERS
AHEAD OF THE COLD FRONT TOO...BUT AGAIN THE MAJORITY OF THE DAY IS
DRY. A BIT OF A BREEZE OUT OF THE WEST SOUTHWEST TOO...BUT OVERALL A
VERY NICE DAY.
WINDS DIMINISH THU NIGHT WITH SKIES BECOMING CLEAR. THIS WILL ALLOW
FOR A GOOD NIGHT OF RADIATIONAL COOLING WITH LOW TEMPS MAINLY IN THE
40S...BUT SOME UPPER 30S POSSIBLE IN THE NORMALLY COOLEST OUTLYING
LOCATIONS.
KEY MESSAGE 2...DRY WEATHER PREVAILS FRIDAY THROUGH EARLY SUNDAY,
WITH ANOTHER FROSTY START POSSIBLE SATURDAY. RAIN IS INCREASINGLY
LIKELY LATE SUNDAY INTO COLUMBUS DAY, THOUGH UNCERTAINTY REMAINS
WITH ONSET TIMING AND RAINFALL AMOUNTS.
THE EXTENDED FORECAST REMAINS ON TRACK WITH NO MAJOR SHIFTS. STRONG
1030+ MB HIGH PRESSURE BUILDS OVER THE NORTHEAST FRIDAY AND
SATURDAY, SUPPORTING SUNNY AND DRY CONDITIONS. HIGHS FRIDAY ARE
SEASONABLY COOL IN THE POST-FRONTAL AIRMASS, MAINLY IN THE LOWER TO
MIDDLE 60S. WAA DEVELOPS ALOFT SATURDAY AS 925 MB TEMPERATURES
INCREASE FROM AROUND +8C FRIDAY TO +9C TO +12C SATURDAY, SUPPORTING
HIGHS IN THE MIDDLE 60S TO LOWER 70S. ANOTHER FROSTY START IS
POSSIBLE SATURDAY, ESPECIALLY IN THE TYPICALLY COLDER LOCATIONS
WHERE LIGHT/CALM WINDS FAVOR EFFECTIVE RADIATIONAL COOLING. THE NBM
DOESN'T CAPTURE THIS PARTICULARLY WELL, SO BLENDED IN MOS GUIDANCE,
RESULTING IN LOWS IN THE MID 30S ACROSS THE COLDER LOCATIONS WHILE
THE URBAN CORE REMAINS IN THE MID TO UPPER 40S.
CONFIDENCE IS HIGH IN DRY WEATHER FRIDAY THROUGH EARLY SUNDAY GIVEN
STRONG ENSEMBLE AGREEMENT ON HIGH PRESSURE DOMINATING THE NORTHEAST.
CONFIDENCE DECREASES THEREAFTER WITH RESPECT TO TIMING AND RAINFALL
AMOUNTS, THOUGH IT IS LOOKING INCREASINGLY LIKELY THAT RAIN ARRIVES
SOMETIME LATE SUNDAY AND CONTINUES INTO COLUMBUS DAY. HIGH PRESSURE
SHIFTS EAST SUNDAY AS REMNANT MOISTURE FROM ISAIAS BEGINS TO
APPROACH SOUTHERN NEW ENGLAND. ISAIAS, CURRENTLY OVER THE SOUTHWEST
GULF, IS EXPECTED TO MAKE LANDFALL FRIDAY NIGHT ON THE GULF COAST.
GUIDANCE STILL SHOWS A FAIRLY WIDE WINDOW FOR THE ONSET OF RAIN,
RANGING FROM LATE SUNDAY MORNING TO AFTER SUNSET, BUT CONFIDENCE IS
MODERATE TO HIGH THAT RAIN OCCURS SUNDAY NIGHT INTO MONDAY.
THERE ARE SIGNALS THAT THIS COULD BE A SOAKING RAIN, THOUGH
CONFIDENCE IN AMOUNTS REMAINS LOWER. PWATS INCREASE TO 2-3 STANDARD
DEVIATIONS ABOVE CLIMATOLOGY, WHILE DESI PROBABILITIES FOR 0.50+
INCHES OF RAIN FROM 8 PM SUNDAY TO 8 PM MONDAY RANGE FROM AROUND 45
PERCENT ACROSS NORTHERN MASSACHUSETTS TO 60-70 PERCENT ALONG COASTAL
RHODE ISLAND AND MASSACHUSETTS. PROBABILITIES FOR 2+ INCHES REMAIN
LOW, AROUND 10-15 PERCENT AND MAINLY CONFINED TO BLOCK ISLAND,
MARTHA'S VINEYARD AND NANTUCKET.
FORECAST CONFIDENCE BECOMES QUITE LOW BY TUESDAY, THOUGH THE PATTERN
FAVORS CONTINUED UNSETTLED WEATHER AS A COLD FRONT POTENTIALLY
APPROACHES FROM THE WEST. OTHERWISE, NO SIGNIFICANT CHANGES TO
TEMPERATURES, WITH HIGHS GENERALLY IN THE 60S TO AROUND 70 SUNDAY
THROUGH TUESDAY AND OVERNIGHT LOWS IN THE UPPER 40S AND 50S.
AVIATION /06Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE...HIGH CONFIDENCE.
VFR CONDITIONS CONTINUE THROUGH FRIDAY. S WINDS OF 5-15 KNOTS
EARLY THIS MORNING WITH SOME 20+ KNOT GUSTS AT TIMES. A FEW
BRIEF PASSING SHOWERS POSSIBLE MAINLY THU MORNING...BUT THIS
WOULD BE SHORT- LIVED. WSW WIND GUSTS OF 15 TO 25 KNOTS EXPECTED
THU...BUT THESE SHOULD DIMINISH AND BECOME W BY THU NIGHT. VFR
FRIDAY WITH W WIND 10-15 KTS GUSTING TO 20 KTS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT THROUGH SATURDAY NIGHT: VFR.
SUNDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. BREEZY. CHANCE
SHRA.
SUNDAY NIGHT: MAINLY MVFR, WITH AREAS VFR POSSIBLE. BREEZY.
SHRA.
COLUMBUS DAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY.
CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT THROUGH THURSDAY NIGHT...HIGH CONFIDENCE.
A SW LOW LEVEL JET AHEAD OF AN APPROACHING COLD FRONT WILL RESULT IN
SW WIND GUSTS OF 20-25 KNOTS DEVELOPING TONIGHT AND PERSISTING INTO
THU AFTERNOON. SMALL CRAFT ADVISORIES HAVE BEEN POSTED FOR MOST OF
OUR WATERS. WIND GUSTS SHOULD DROP BELOW SMALL CRAFT THRESHOLDS
LATER THU AND ESPECIALLY THU NIGHT.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH SATURDAY NIGHT: WINDS LESS THAN 25 KT.
SUNDAY: WINDS LESS THAN 25 KT. CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. RAIN SHOWERS LIKELY, SLIGHT CHANCE OF THUNDERSTORMS.
COLUMBUS DAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EDT THIS AFTERNOON FOR
ANZ231>235-237-254>256.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ250-
251.
DISCUSSION...FRANK/DOOLEY
AVIATION...BW
MARINE...FRANK/DOOLEY
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