928
FXUS61 KBOX 291952
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
252 PM EST THU JAN 29 2026
WHAT HAS CHANGED
COLD WEATHER ADVISORIES FOR DANGEROUSLY COLD WIND CHILLS WERE
EXPANDED TO INCLUDE CAPE COD TONIGHT INTO FRI MORNING. WINTER
STORM WATCHES WERE ISSUED FOR THE CAPE AND ISLANDS FOR LATE SAT
NIGHT THROUGH SUNDAY NIGHT. HOWEVER, LATEST TRENDS FAVOR A MORE
OFFSHORE STORM TRACK AND SOMEWHAT LESS IMPACTS ACROSS SOUTHERN
NEW ENGLAND.
KEY MESSAGES
- DANGEROUSLY COLD WIND CHILLS TONIGHT INTO FRIDAY MORNING, AND
POSSIBLY FRI NIGHT INTO SAT MORNING.
- STILL A LARGE DEGREE OF UNCERTAINTY SURROUNDING A WINTER STORM
SUNDAY INTO SUNDAY NIGHT. STRONG GUSTY WINDS AND ACCUMULATING
SNOW ARE CERTAINLY WITHIN THE REALM OF POSSIBILITY FOR THE
CAPE AND ISLANDS.
- MINOR TO MODERATE COASTAL FLOODING POSSIBLE SUNDAY INTO
MONDAY.
DISCUSSION
KEY MESSAGE 1...DANGEROUSLY COLD WIND CHILLS TONIGHT INTO FRIDAY
MORNING, AND POSSIBLY FRI NIGHT INTO SAT MORNING.
A REINFORCING SHOT OF ARCTIC AIR WILL MOVE INTO NEW ENG TONIGHT AND
FRIDAY AS A NORTHERN STREAM TROUGH DROPS SOUTH FROM CANADA. THE
TROUGH PASSAGE WILL BE ACCOMPANIED BY A SURGE OF GUSTY WNW WINDS TO
15-25 MPH TONIGHT INTO FRI MORNING. THIS COUPLED WITH LOWS OF -5 TO
+5F WILL RESULT IN WIND CHILLS OF -10 TO -20F FOR MUCH OF SNE, WITH
THE COLDEST READINGS OVER THE HIGHER ELEVATIONS WHERE WIND CHILLS
DOWN TO -20 TO -25F ARE EXPECTED. WE WILL CONTINUE THE COLD WEATHER
ADVISORY FOR DANGEROUS WIND CHILLS FOR MUCH OF SNE, EXCEPT THE CAPE
AND ISLANDS WHERE WIND CHILLS WILL FALL A BIT SHORT OF -10F CRITERIA.
WINDS DROP OFF A BIT FRI NIGHT BUT LOW TEMPS ARE EXPECTED TO BE EVEN
COLDER WITH LOWS ZERO TO -10F AWAY FROM THE IMMEDIATE COAST. THERE
WILL BE ENOUGH WIND TO GENERATE SIMILAR WIND CHILLS OF -10 TO -20F
LATE FRI NIGHT INTO SAT MORNING. COLD WEATHER ADVISORIES WILL
LIKELY NEED TO BE EXTENDED.
DRY WEATHER EXPECTED THROUGH SAT, WITH MOSTLY SUNNY DAYS AND MAINLY
CLEAR NIGHTS. THE COLUMN IS QUITE DRY THROUGH SAT.
KEY MESSAGE 2...STILL A LARGE DEGREE OF UNCERTAINTY SURROUNDING
A WINTER STORM SUNDAY INTO SUNDAY NIGHT. STRONG GUSTY WINDS AND
ACCUMULATING SNOW ARE CERTAINLY WITHIN THE REALM OF POSSIBILITY
FOR THE CAPE AND ISLANDS.
ENSEMBLE AND DETERMINISTIC GUIDANCE CONTINUES TO INDICATE A COASTAL
STORM MOVING OFF THE NC/SC COAST, RAPIDLY INTENSIFYING AS IT MOVES
NORTH AND EAST. PREVIOUS GUIDANCE HAS HAD A LARGE AMOUNT OF
UNCERTAINTY REGARDING WHERE EXACTLY THE LOW MAY PASS IN RELATION TO
SOUTHERN NEW ENGLAND, WITH SOME MODELS TAKING A MORE NORTHERLY TRACK
AND SOME A MORE SOUTHERLY. THE LATEST SUITE OF GUIDANCE CONTINUES
TO BE HIGHLY VARIABLE REGARDING THE POTENTIAL FOR ACCUMULATING SNOW
AND STRONG GUSTY WINDS SUNDAY INTO SUNDAY NIGHT. THE 12Z ECMWF, GFS,
AND CANADIAN ENSEMBLES HAVE TRENDED THE GENERAL LOCATION OF THE
SURFACE LOW FURTHER SOUTH AND EAST THAN PREVIOUS RUNS, WITH THE
LATEST GRAND ENSEMBLE AND SUBSEQUENT CLUSTERS SHOWING A POSITIVELY-
TILTED UPPER TROUGH, POSSIBLY LEADING TO THE LATEST SOUTHEASTWARD
TREND. IF THE STORM TRACKS FURTHER SOUTH AND EAST, THE HIGHEST WINDS
AND SNOWFALL TOTALS WOULD BE CONFINED TO THE SOUTHERN CAPE AND
ISLANDS, WHILE A SHARP GRADIENT SETS UP SOMEWHERE OVER THE SOUTH
SHORE, LEADING TO SIGNIFICANTLY DECREASED CHANCES OF BOSTON,
PROVIDENCE, AND THE I-95 CORRIDOR SEEING MODERATE IMPACTS.
GFS AND CANADIAN ENSEMBLES ARE SHOWING PWATS >0.33" OVER THE FAR
SOUTHEASTERN PORTION OF THE CAPE AND NANTUCKET, WITH A SHARP,
DECREASING GRADIENT OVER THE NORTHERN PORTION OF THE CAPE. THE ECMWF
ENSEMBLE HAS TAKEN A MORE MOISTURE-LOADED APPROACH, BRINGING PWATS
RANGING FROM 0.33" ALONG THE I-95 CORRIDOR TO 0.66" ON NANTUCKET.
NBM 5.0 PROBABILITIES OF SEEING 6" OF SNOW IN 24 HOURS OVER THE CAPE
AND ISLANDS HAVE DECREASED FROM 50%-65% LAST NIGHT TO 40%-50% WITH
THE LATEST RUN, WITH PROBABILITES FOR THE I-95 CORRIDOR DROPPING
FROM 35%-50% TO NEAR 25%. THE LATEST WSSI-P PROBABILITIES FOR
MODERATE IMPACTS HAS ALSO SIGNIFICANTLY DECREASED TO 40% OVER THE
CAPE AND ISLANDS AND 20% ACROSS THE I-95 CORRIDOR. AFTER
COORDINATING WITH THE NEIGHBORING OFFICES AND WPC, FELT MODERATELY
CONFIDENT IN ISSUING A WINTER STORM WATCH FOR THE CAPE AND ISLANDS
BEGINNING AFTER MIDNIGHT SUNDAY MORNING.
REGARDLESS OF HOW FAR SOUTHEAST THE LOW PASSES, EXPECTING A WIDE-
REACHING, INTENSE PRESSURE GRADIENT TO WHIP UP WINDS SUNDAY. LATEST
NBM PROBABILITES OF REACHING 55MPH WINDS GUSTS (STORM FORCE WINDS)
ACROSS THE INNER WATERS RANGE FROM 45% TO 65% AND >75% ACROSS THE
OUTER WATERS, AND THESE PROBS HAVE REMAINED STEADY OVER THE LAST 24
HOURS. THEREFORE, FELT CONFIDENT IN ISSUING STORM WATCHES FOR THE
OUTER WATERS, INCLUDING CAPE COD BAY.
KEY MESSAGE 3...MINOR TO MODERATE COASTAL FLOODING POSSIBLE
SUNDAY INTO MONDAY.
A COASTAL FLOOD WATCH HAS BEEN ISSUED FOR THE EASTERN MASSACHUSETTS
COASTLINE SUNDAY INTO MONDAY.
HIGH ASTRONOMICAL TIDES COMBINED WITH AT LEAST A 1 TO 3 FOOT STORM
SURGE AND STRONG N/NE WINDS WILL BRING THE POTENTIAL FOR MINOR TO
PERHAPS MODERATE COASTAL FLOODING ALONG THE EASTERN MASSACHUSETTS
COAST DURING HIGH TIDES SUNDAY MORNING, SUNDAY EVENING, AND MONDAY
AROUND MIDDAY.
BASED UPON THE PROJECTED OFFSHORE TRACK OF THE COASTAL STORM, THE
HIGHEST WINDS AND STORM SURGE SHOULD BE FOCUSED CLOSER TO CAPE COD,
NANTUCKET, AND MARTHAS VINEYARD WHERE THE HIGHER CHANCES OF SEEING
MODERATE FLOODING EXISTS. HOWEVER, BUILDING SEAS OF 20-25 FEET
OFFSHORE WILL ADD ADDITIONAL IMPACTS TO THE OCEAN EXPOSED COASTLINE
FROM PLYMOUTH COUNTY NORTH TO THE MERRIMACK RIVER, SO DESPITE LOWER
WATER LEVELS, THOSE AREAS COULD STILL SEE MODERATE IMPACTS.
ADDITIONALLY, THE LONG OVERWATER FETCH SHOULD RESULT IN SIGNIFICANT
BEACH AND DUNE EROSION, ESPECIALLY IN AREAS THAT HAVE BEEN HARD HIT
IN RECENT YEARS INCLUDING NEWBURYPORT/PLUM ISLAND, SANDWICH, CHATHAM,
AND EDGARTOWN.
SHOULD THE STORM TREND FARTHER OFFSHORE, THE THREAT OF COASTAL
FLOODING WOULD DECREASE, BUT GIVEN THE HIGH ASTRONOMICAL TIDES IT IS
REASONABLE TO EXPECT AT LEAST MINOR COASTAL FLOODING. A TREND CLOSER
TO NEW ENGLAND WOULD RAISE THE ODDS OF MODERATE FLOODING OVER MUCH
OF THE COASTLINE, BUT THE CHANCES OF REACHING MAJOR FLOOD IMPACTS
WOULD STILL REMAIN VERY LOW.
AS A REMINDER, MINOR FLOODING REFERS TO SHALLOW FLOODING UP TO
1 FOOT DEEP AND CAN RESULT IN TEMPORARY ROAD CLOSURES ON MORE
VULNERABLE COASTAL ROADS. MODERATE FLOODING REFERS TO FLOODING 1
TO 3 FEET DEEP AND CAN CAUSE MORE WIDESPREAD ROAD CLOSURES,
DAMAGE TO SHOREFRONT PROPERTY, AND DEBRIS ON COASTAL ROADS FROM
LARGE WAVES. VEHICLES LEFT IN FLOOD PRONE AREAS CAN ALSO BE
FLOODED.
AVIATION /19Z THURSDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH FRIDAY NIGHT...HIGH CONFIDENCE.
VFR. LOWER BASES BETWEEN 020-040 ACROSS THE OUTER CAPE AND
POSSIBLY NANTUCKET AS WELL LATER TODAY. WNW WINDS BECOME GUSTY
OVERNIGHT AND CONTINUE INTO FRIDAY. WINDS EXPECTED TO SHIFT MORE
W AND DIMINISH FRIDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: VFR.
SATURDAY NIGHT: VFR. STRONG WINDS WITH LOCAL GUSTS UP TO 40 KT.
SLIGHT CHANCE SN.
SUNDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. STRONG WINDS WITH
GUSTS UP TO 50 KT. CHANCE SN.
SUNDAY NIGHT: VFR. STRONG WINDS WITH GUSTS UP TO 50 KT. CHANCE
SN.
MONDAY: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
MONDAY NIGHT: VFR. BREEZY.
TUESDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
* MODERATE TO HEAVY FREEZING SPRAY DEVELOPING ON THE WATERS TONIGHT
INTO FRIDAY
* DANGEROUS MARINE CONDITIONS DEVELOPING SUNDAY
A PERIOD OF WNW GUSTS TO 25-30 KT WILL DEVELOP TONIGHT INTO
FRIDAY, THEN DIMINISHING WIND FRI NIGHT. THE GUSTY WINDS WILL BE
ACCOMPANIED BY A REINFORCING SHOT OF ARCTIC AIR WHICH WILL
RESULT IN WIDESPREAD MODERATE FREEZING SPRAY WITH AREAS OF
HEAVY FREEZING SPRAY OVER SOME OF THE NEARSHORE WATERS.
SIGNIFICANT ACCRETION OF ICE IS EXPECTED ON VESSELS OVER THE
WATERS. FREEZING SPRAY ADVISORIES AND HEAVY FREEZING SPRAY
WARNINGS REMAIN IN EFFECT.
OUR ATTENTION TURNS TO A POWERFUL OCEAN STORM WHICH TRACKS WELL
SOUTH AND EAST OF THE WATERS ON SUNDAY. POTENTIAL FOR STORM
FORCE NE GUSTS TO 50-55 KT OVER THE OUTER WATERS PEAKING DURING
SUNDAY, WITH 40-50 KT GUSTS OVER NEARSHORE WATERS. SEAS EXPECTED
TO BUILD TO 20+ FT ON THE WATERS EAST OF CAPE COD RESULTING IN
DANGEROUS CONDITIONS FOR MARINERS. IN ADDITIONS, AREAS OF LIGHT
TO MODERATE FREEZING SPRAY WILL DEVELOP SAT NIGHT THOUGH SUN
NIGHT.
OUTLOOK /MONDAY THROUGH TUESDAY/...
MONDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. ROUGH SEAS UP TO 20 FT. FREEZING SPRAY.
MONDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
TUESDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
FRIDAY FOR CTZ002>004.
MA...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
FRIDAY FOR MAZ002>022-026.
COASTAL FLOOD WATCH FROM SUNDAY MORNING THROUGH MONDAY
AFTERNOON FOR MAZ007-015-016-019-022>024.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH LATE
SUNDAY NIGHT FOR MAZ022>024.
RI...COLD WEATHER ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
FRIDAY FOR RIZ001>007.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST FRIDAY
FOR ANZ230-236.
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR
ANZ230.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 PM EST
FRIDAY FOR ANZ231>235-237-251.
FREEZING SPRAY ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
FRIDAY FOR ANZ231-235>237-250-251-254-256.
STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR
ANZ231-232-250-254>256.
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 PM
EST FRIDAY FOR ANZ232>234-255.
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY NIGHT
FOR ANZ233>235-237.
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY EVENING FOR
ANZ236.
SMALL CRAFT ADVISORY UNTIL 1 AM EST SATURDAY FOR ANZ250-
254>256.
GALE WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING FOR
ANZ251.
DISCUSSION...KJC/MCMINN/JWD
AVIATION...BELK
MARINE...KJC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page