859
FXUS61 KBOX 241703
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1203 PM EST SAT JAN 24 2026
WHAT HAS CHANGED
THE FORECAST REMAINS ON TRACK, WITH MINIMAL CHANGES TO SUNDAY'S
SNOWSTORM.
KEY MESSAGES
- DANGEROUSLY COLD WIND CHILLS LINGER THROUGH SATURDAY.
- SIGNIFICANT ICING POSSIBLE FROM FREEZING SPRAY ON THE COASTAL
WATERS.
- A COASTAL STORM WILL BRING HEAVY SNOW TO SOUTHERN NEW ENGLAND
SUNDAY INTO MONDAY. HEAVY SNOW WITH 1"+ INCH PER HOUR SNOW RATES
SUNDAY EARLY EVENING TO EARLY MONDAY MORNING WILL MAKE TRAVEL VERY
DIFFICULT. INCREASING EASTERLY WINDS COULD PRODUCE AREAS OF BLOWING
SNOW.
- COLD AND MOSTLY DRY MID WEEK THEN THERE IS POTENTIAL FOR SOME
UNSETTLED WEATHER THE LATTER HALF OF THE WEEK.
DISCUSSION
KEY MESSAGE 1...DANGEROUSLY COLD WIND CHILLS LINGER THROUGH
SATURDAY.
THE ARCTIC FRONT HAS NOW PASSED THROUGH SOUTHERN NEW ENGLAND,
BRINGING GUSTY WINDS AND PLUMMETING TEMPERATURES. 00Z SOUNDINGS FROM
OKX AND ALY SHOW 850MB TEMPERATURES OF -11C AND -21C, AND EXPECTING
TEMPERATURES ALOFT TO CONTINUE FALLING TO -25C TO -27C THROUGHOUT
THE NIGHT AND INTO THE MORNING. DEEP MIXING TO NEAR 850MB WILL BRING
GUSTS OF 30-40 MPH TO THE SURFACE THROUGH THE NIGHT. PROLONGED GUSTY
WINDS IN COMBINATION WITH ALREADY FRIGID SURFACE TEMPERATURES IN THE
NEGATIVES TO LOW SINGLE DIGITS WILL BRING WIND CHILLS AS LOW AS
-25F IN THE EASTERN SLOPES OF THE BERKSHIRES AND -10F TO -15F
EVERYWHERE ELSE. TEMPERATURES SATURDAY WILL STRUGGLE TO IMPROVE,
WITH HIGHS EXPECTED IN THE LOW TO MID TEENS... EXCEPT SINGLE DIGITS
IN THE HIGH ELEVATIONS.
KEY MESSAGE 2...SIGNIFICANT ICING POSSIBLE FROM FREEZING SPRAY
ON THE COASTAL WATERS.
NORTHWESTERLY GALE FORCE WINDS OF UP TO 40KT OVER THE COASTAL WATERS
COMBINED WITH THE ARCTIC COLD IS EXPECTED TO LEAD TO MODERATE,
POSSIBLY EVEN HEAVY, FREEZING SPRAY THROUGH SATURDAY. VESSELS
ENCOUNTERING HEAVY FREEZING SPRAY COULD SEE ICE ACCRETION RATES OF
0.8"-1.6" PER HOUR. THE POSSIBILITY FOR HEAVIEST FREEZING SPRAY IS
EXPECTED ALONG THE SOUTHERN AND EASTER WATERS, PARTICULARLY WITHIN
NANTUCKET SOUND. LIGHT FREEZING SPRAY SHOULD PERSIST MUCH OF THE DAY
SATURDAY.
KEY MESSAGE 3...A COASTAL STORM WILL BRING HEAVY SNOW TO SOUTHERN
NEW ENGLAND SUNDAY INTO MONDAY. HEAVY SNOW WITH 1"+ INCH PER HOUR
SNOW RATES SUNDAY EARLY EVENING TO EARLY MONDAY MORNING WILL MAKE
TRAVEL VERY DIFFICULT. INCREASING EASTERLY WINDS COULD PRODUCE
AREAS OF BLOWING SNOW.
GUIDANCE CONTINUED TO HOLD STEADY OVERNIGHT WITH NO SIGNIFICANT
CHANGES TO THINKING WITH REGARD TO OUR UPCOMING SNOWSTORM. THIS
MAJOR STORM, THE LARGEST WE'VE EXPERIENCED IN SEVERAL YEARS,
ORIGINATES AS A MULTIFACETED WINTER STORM OVER THE SOUTHERN PLAINS
AND SOUTHEAST U.S. LATER TODAY. THE PLUME OF SUBTROPICAL MOISTURE
WILL THEN MOVE UP THROUGH THE MID-ATLANTIC AND INTO NEW ENGLAND ON
SUNDAY. AS IT DOES, STRONG WARM ADVECTION WILL ENCOUNTER THE DOME OF
ARCTIC AIR CURRENTLY OVERHEAD AND BE LIFTED, SQUEEZING OUT COPIOUS
AMOUNTS OF MOISTURE IN THE FORM OF SNOW. ALL THE INGREDIENTS FOR
HEAVY SNOW ARE THERE, WITH A VERY COLD ANTECEDENT AIRMASS, PLUME OF
SUBTROPICAL MOISTURE, AND STRONG WARM ADVECTION/FRONTOGENETICAL
FORCING IN THE LOW/MID LEVELS. MODELS INDICATE A VERY STRONG BAND OF
FRONTOGENESIS AT 700MB AND 850 MB LIFTING NORTH SUNDAY AFTERNOON
WHILE BUFKIT SOUNDINGS SHOW A PERIOD OF STRONG OMEGA WITHIN THE -12
TO -18F DENDRITIC GROWTH ZONE. TOGETHER WITH THE ANOMALOUS MOISTURE
PRESENT THIS WILL RESULT IN A PERIOD OF SNOWFALL RATES 1-2 INCHES
SUNDAY AFTERNOON THROUGH AROUND MIDNIGHT FOR VARIOUS PARTS OF SNE.
AFTER MIDNIGHT A DRY SLOT MOVES OVERHEAD DESATURATING THE DGZ SO
SNOW IS EXPECTED TO BECOME LIGHTER (WITH SMALLER DENDRITES),
CONTINUING THROUGH THE DAY ON MONDAY AS MOISTURE WRAPS AROUND THE
EXITING LOW. GIVEN THE STRONG FORCING IN THE DGZ AND THE COLD
TEMPERATURES, EXPECTING VERY FLUFFY SNOW DURING THE BULK OF THE
EVENT. THIS WILL LEAD TO VERY HAZARDOUS DRIVING CONDITIONS CENTERED
AROUND SUNDAY EVENING/EARLY OVERNIGHT. GENERALLY EXPECTING 13-18
INCHES OF SNOW FOR MOST, WITH SOME LOCATIONS ESPECIALLY IN EASTERN
MA AND THE BERKSHIRES SEEING LOCALIZED AMOUNTS CLOSER TO 20 INCHES
THANKS TO OCEAN AND OROGRAPHIC ENHANCEMENT RESPECTIVELY. WE ALSO
HAVE TO WATCH FOR SOME MESOSCALE BANDING WHICH IS WHERE WE'D MORE
LIKELY SEE THESE HIGHER TOTALS. THESE BANDS TEND TO SET UP NW OF THE
FRONTOGENESIS MAXIMA, SO THIS WOULD SUGGEST SOMEWHERE IN THE CENTRAL
MA REGION. ALSO A COASTAL FRONT OVER SOUTHEAST MA COULD ALSO MAKE
THAT AREA FAVORABLE. IT IS NEXT TO IMPOSSIBLE TO NAIL THE EXACT
PLACEMENT OF THESE WITH MUCH LEAD TIME.
WE CONTINUE TO SEE SIGNS OF A 700 MB WARM NOSE MOVING UP INTO THE
SOUTH COAST DURING THE EARLY OVERNIGHT HOURS, WHICH MAY CAUSE SOME
SLEET TO MIX IN AND BRING DOWN TOTALS IN RI AND SOUTHEAST MA.
REGARDLESS, THOUGH, HIGHLY IMPACTFUL SNOW IS EXPECTED EVERYWHERE.
FINALLY, WHILE WE'RE NOT EXPECTING A BIG POWER OUTAGE RISK FROM THIS
SYSTEM THANKS TO THE FLUFFY NATURE OF THE SNOW AND THE LACK OF
DAMAGING WIND GUSTS, WINDS WILL STILL BE QUITE GUSTY. 30-40 MPH
GUSTS SUNDAY EVENING COULD LEAD TO SOME LOCALIZED BLOWING SNOW AND
REDUCED VISIBILITY FOR A TIME.
KEY MESSAGE 4...COLD AND MOSTLY DRY MID WEEK THEN THERE IS POTENTIAL
FOR SOME UNSETTLED WEATHER THE LATTER HALF OF THE WEEK.
THE SNOW ISN'T GOING ANYWHERE FAST AS THE SUBFREEZING AIRMASS SITS
OVERHEAD WELL INTO NEXT WEEK THANKS TO A LINGERING MID LEVEL TROUGH.
EXPECTING DRY NW FLOW THROUGH AT LEAST WEDNESDAY BEFORE OUR NEXT
DISTURBANCE ROUNDS THE BASE OF THE TROUGH BRINGING PRECIPITATION
CHANCES BACK TO THE FORECAST AROUND THURSDAY.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z UPDATE: HIGH CONFIDENCE.
VFR THROUGH TONIGHT AS NW WINDS DIMINISH BY LATE AFTERNOON AND
VEER TO N/NE OVERNIGHT. LIGHT SNOW BEGINS IN WESTERN NEW ENGLAND
13Z-15Z AND 15Z-17Z FARTHER EAST WHICH BRINGS A RAPID DROP TO
IFR CONDITIONS. EXPECTING HEAVY SNOW TO ARRIVE WITHIN 1-3 HOURS
OF ONSET WITH WIDESPREAD LIFR CONDITIONS LATER SUNDAY AFTERNOON
AND THE FIRST PART OF SUNDAY NIGHT. SNOWFALL RATES OF 1-3" PER
HOUR ARE LIKELY. SNOW LESSENS IN INTENSITY OVERNIGHT INTO
MONDAY BUT THERE SHOULD BE A CHANGE TO RAIN FOR A TIME ON THE
ISLANDS AND POSSIBLY CAPE COD, WITH SOME SLEET POSSIBLE ALONG
THE SOUTH COAST.
SNOWFALL TOTALS BY MONDAY MORNING SHOULD RANGE FROM 6-12" ALONG
THE SOUTH COAST, CAPE COD, AND ISLANDS TO 12-18" ELSEWHERE. MUCH
OF THIS WILL FALL FROM LATER SUNDAY AFTERNOON THROUGH MIDNIGHT
MONDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. FORECAST IS FOR 16" OF
SNOW AT LOGAN AIRPORT.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. FORECAST IS FOR 15" OF
SNOW AT BRADLEY AIRPORT.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT. SN, FZRA.
MONDAY: MAINLY IFR, WITH AREAS MVFR POSSIBLE. WINDY WITH LOCAL
GUSTS UP TO 30 KT. SN.
MONDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH
AREAS OF GUSTS UP TO 30 KT. CHANCE SN.
TUESDAY: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
TUESDAY NIGHT THROUGH WEDNESDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THE WEEKEND.
ARCTIC AIR ARRIVES INTO SATURDAY MORNING ALONG WITH NORTHWESTERLY
GALE FORCE WINDS, RESULTING IN MODERATE TO HEAVY FREEZING SPRAY.
FREEZING SPRAY WILL BECOME LIGHTER THROUGHOUT SATURDAY AFTERNOON,
BUT SHOULD STILL PERSIST ALL DAY. WINDS DIMINISH SATURDAY NIGHT.
A WINTER STORM ARRIVES SUNDAY INTO MONDAY WITH POOR VISIBILITY
DURING HEAVY SNOW. SLEET MAY MIX INTO THE SNOW AT SOME POINT IN THE
LATER HALF OF THE STORM OVER SOUTH COASTAL WATERS. NORTHEASTERLY
WINDS MAY REACH SCA SUNDAY, BUT OF MORE CONCERN IS FOR A PERIOD OF
GALE FORCE WEST-NORTHWESTERLY WINDS BEHIND STORM LATER SUNDAY NIGHT
INTO MONDAY.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: MODERATE RISK FOR GALE FORCE WINDS WITH GUSTS UP
TO 40 KT. ROUGH SEAS UP TO 12 FT. SNOW, RAIN, SLEET. VISIBILITY
1 NM OR LESS.
MONDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. ROUGH SEAS UP TO 13 FT. SNOW, RAIN LIKELY.
VISIBILITY 1 TO 3 NM.
MONDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 40 KT. ROUGH SEAS
UP TO 15 FT. CHANCE OF SNOW, CHANCE OF FREEZING SPRAY. AREAS OF
VISIBILITY 1 TO 3 NM.
TUESDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS UP TO
14 FT. CHANCE OF FREEZING SPRAY, SLIGHT CHANCE OF SNOW.
TUESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. CHANCE OF FREEZING
SPRAY, SLIGHT CHANCE OF SNOW.
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 25 KT. LOCAL ROUGH SEAS. CHANCE OF FREEZING SPRAY.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER STORM WARNING FROM 7 AM SUNDAY TO 8 PM EST MONDAY FOR
CTZ002>004.
MA...WINTER STORM WARNING FROM 7 AM SUNDAY TO 8 PM EST MONDAY FOR
MAZ002>024-026.
EXTREME COLD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR MAZ002-
008-009.
RI...WINTER STORM WARNING FROM 7 AM SUNDAY TO 8 PM EST MONDAY FOR
RIZ001>008.
MARINE...FREEZING SPRAY ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ230-233>237-256.
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
ANZ230>237-250-251-254>256.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
ANZ231-232-250-251-254-255.
DISCUSSION...BW/MCMINN
AVIATION...JWD
MARINE...BW/MCMINN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page