754
FXUS61 KBOX 311123
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
623 AM EST SAT JAN 31 2026
WHAT HAS CHANGED
COASTAL STORM FOR SUNDAY CONTINUES TO TREND FURTHER OFFSHORE.
WINTER STORM WATCHES CONVERTED TO WINTER WEATHER ADVISORIES FOR
THE CAPE AND ISLANDS FOR SUNDAY. EXPECTATIONS FOR MINOR
INUNDATION FOR SUNDAY MORNING, EVENING AND MONDAY MORNING TIDAL
CYCLES LED TO CONVERTING COASTAL FLOOD WATCH FOR THE EASTERN MA
COAST TO COASTAL FLOOD ADVISORIES, BUT THE COASTAL FLOOD WATCH
WAS MAINTAINED FOR THE CAPE AND ISLANDS.
KEY MESSAGES
- FRIGID TEMPERATURES CONTINUE TODAY, AND WHILE SUB- ZERO WIND
CHILLS ARE AGAIN EXPECTED TONIGHT, WIND CHILLS MAY NOT DROP AS
LOW AS THE PAST COUPLE NIGHTS.
- A POWERFUL COASTAL STORM PASSING OFFSHORE OF SOUTHERN NEW
ENGLAND BRINGS ACCUMULATING SNOW, GUSTY WINDS, HAZARDOUS
MARINE CONDITIONS AND MINOR TO POCKETS OF MODERATE COASTAL
FLOODING TO EASTERN AND SOUTHEAST NEW ENGLAND.
- DRY WEATHER AND NOT AS COLD INTO THE MIDDLE OF NEXT WEEK,
THOUGH TURNS COLDER AND MORE ACTIVE LATE NEXT WEEK/EARLY
WEEKEND.
DISCUSSION
EY MESSAGE 1...FRIGID TEMPERATURES CONTINUE TODAY, AND WHILE SUB-
ZERO WIND CHILLS ARE AGAIN EXPECTED TONIGHT, WIND CHILLS MAY NOT
DROP AS LOW AS THE PAST COUPLE NIGHTS.
COLD WEATHER ADVISORIES CONTINUE INTO THE MORNING TODAY. ALTHOUGH A
LAYER OF STRATUS HAS DEVELOPED ACROSS WESTERN NEW ENGLAND, MUCH OF
SOUTHERN NEW ENGLAND IS CLOUD-FREE AND THAT'S ALLOWED FOR TEMPS TO
REALLY BOTTOM OUT. WIND CHILLS HAVE BEEN MORE IN THE -5 TO -15 RANGE
IN MOST AREAS. TODAY ENDS UP STILL BRING ANOTHER FRIGID DAY, WITH
HIGHS IN THE UPPER TEENS TO LOWER 20S. MORE MIXED SIGNALS IF ANOTHER
COLD WEATHER ADVISORY IS WARRANTED FOR TONIGHT; NORTHEAST WINDS DO
PICK UP WHICH WILL LOWER THE WIND CHILLS, BUT THE AIRMASS ALSO
STARTS TO MODIFY ENOUGH AND INCREASING CLOUDINESS COULD TEMPER HOW
LOW TEMPERATURES MAY DROP. FORECAST WIND CHILLS TONIGHT IN INTERIOR
SOUTHERN NEW ENGLAND DROP TO AS LOW AS 5 TO 10 BELOW ZERO, WHICH IS
STILL ON THE MARGINAL SIDE.
KEY MESSAGE 2...A COASTAL STORM PASSING OFFSHORE OF SOUTHERN
NEW ENGLAND BRINGS ACCUMULATING SNOW, GUSTY WINDS, HAZARDOUS
MARINE CONDITIONS AND MINOR TO POCKETS OF MODERATE COASTAL
FLOODING TO EASTERN AND SOUTHEAST NEW ENGLAND.
THE 00Z SUITE OF GUIDANCE CONTINUES TO FAVOR AN OFFSHORE PASS OF A
POWERFUL COASTAL STORM EXPECTED TO DEVELOP NEAR THE NC/SC COAST
TODAY. WHILE THE 00Z ECMWF AND TO AN EXTENT THE 00Z NAM CONTINUES TO
BE THE MOST MOISTURE-LADEN AND ON THE WESTERN ENVELOPE OF THE
STORM'S PRECIPITATION SHIELD (AND BY WESTERN, NO FURTHER WEST THAN
THE EASTERN PORTION OF NARRAGANSETT BAY), BOTH THESE MODELS HAVE
ALSO STRUGGLED THE MOST RUN-TO-RUN. ACROSS THE SUITE OF 00Z
GUIDANCE, THE CONSENSUS TRACK SEEMED SLIGHTLY FURTHER TO THE
SOUTH/EAST (OFFSHORE) THAN EARLIER FORECASTS. THIS HAS LED TO
SLIGHT DOWNWARD REDUCTIONS IN ANTICIPATED SNOW TOTALS, NORTHERLY
WIND GUSTS, AS WELL AS SIGNIFICANT WAVE HEIGHTS. THE LATTER TWO
ELEMENTS ALSO INFLUENCE COASTAL FLOODING EXPECTATIONS.
WE MADE SEVERAL HEADLINE CHANGES OVERNIGHT BASED ON THE ABOVE
TRENDS, WHILE BEING CAUTIOUS OF ADDITONAL SOUTHEASTWARD ADJUSTMENTS
IN THE STORM'S TRACK. THE WINTER STORM WATCH WAS CONVERTED TO A
WINTER WEATHER ADVISORY; WE ALSO ADDED A WINTER WEATHER ADVISORY FOR
THE EASTERN COAST OF PLYMOUTH COUNTY DUE TO OCEAN EFFECT SNOWBANDS
BEING MODELED BY HIGHER-RESOLUTION GUIDANCE, WITH JUST ENOUGH QPF TO
JUSTIFY ONE OFF ROAD IMPACT ALONG ROUTE 3, ALTHOUGH THE GREATER
ACCUMULATION SHOULD BE MORE ALONG THE SOUTHERN PORTION OF EASTERN
PLYMOUTH COUNTY (ROUGHLY KINGSTON SOUTHWARD TO THE CAPE COD CANAL).
OVER THE WATERS, WE CONVERTED GALE WATCHES OVER TO WARNINGS, WITH
STORM WARNINGS ON THE EASTERN/SOUTHEAST WATERS ADJACENT TO NANTUCKET
AND THE OUTER CAPE. FINALLY ON THE COASTAL FLOODING FRONT, HEADLINE
DECISIONS THERE REMAINED CHALLENGING DUE TO THE OFFSHORE TREND AND
THE POTENTIAL FOR LOWER STORM SURGE VALUES. THE COASTAL FLOOD WATCH
WAS CONVERTED TO COASTAL FLOOD ADVISORIES FOR THE EASTERN COAST OF
MA FROM THE MOUTH OF THE MERRIMACK RIVER TO THE CAPE COD CANAL; WE
OPTED TO HOLD THE COASTAL FLOOD WATCH FOR THE CAPE AND ISLANDS AS
THERE STILL IS THE POTENTIAL FOR THE BAY SIDE OF CAPE COD AND
NANTUCKET TO EXPERIENCE AREAS OF MODERATE (2-3 FT INUNDATION)
COASTAL FLOODING, BUT THE CONTINUED OFFSHORE TREND LEFT OPEN THE
POSSIBILITY OF MINOR/1-2 FT INUNDATION.
SNOW/WIND: SPOTTY BANDS OF OCEAN-EFFECT SNOW IN THE INITIAL NE FLOW
COULD BEGIN AS SOON AS THE PRE-DAWN HOURS TONIGHT IN EASTERN
PLYMOUTH COUNTY AND NORTHERN PORTION OF CAPE COD, WHILE TENDING TO
FILL IN FROM THE SOUTH AS THE NORTHWEST PERIPHERY OF THE SYNOPTIC
PRECIPITATION BAND BEGINS TO BRUSH THE SOUTHEAST COAST BY SUNDAY
MORNING. ROADS PROBABLY HAVE BEEN TREATED, BUT THE SNOW SHOULD
SHOULD HAVE NO TROUBLE STICKING IMMEDIATELY WHEN IT FIRST DEVELOPS
GIVEN THE COLD TEMPS WE'VE HAD. SNOW THEN CONTINUES AT A GENERALLY
LIGHT TO AT TIMES MODERATE CLIP THROUGH THE DAY, THEN BEGINS TO
TAPER OFF AROUND EARLY SUNDAY EVENING IN PLYMOUTH AND BRISTOL
COUNTIES, AND CLOSER TO LATE SUNDAY NIGHT OVER THE CAPE AND ISLANDS
AS THE STORM PULLS AWAY AND DRIER NWLY FLOW ENTRENCHED OVER THE
INTERIOR SOUTHERN NEW ENGLAND ADVECTS IN. SNOW GROWTH PARAMETERS IN
THE ADVISORY AREA ARE REALLY MIDDLING AT BEST, EVEN ACROSS THE CAPE;
WHICH IS REFLECTED IN PROBABILITIES OF 1" PER HOUR SNOW RATES BEING
ESSENTIALLY NIL. SO RATES SHOULD BE MORE MANAGEABLE ACROSS THE
ADVISORY AREA, WITH VISBY REDUCTIONS AT LEAST AS MUCH FROM BLOWING
SNOW OFF THE STANDING MOUNDS OF SNOW VERSUS WHAT FALLS FROM THE SKY.
AS MENTIONED, THE 00Z ECMWF REMAINS MOISTER AND HAS ABOUT 50%
PROBABILITIES OF A HALF INCH OF QPF ACROSS NANTUCKET; BUT WE VIEW
THIS AS A MOIST OUTLIER. WE OPTED FOR SNOW TOTALS IN THE 2 TO 4 INCH
RANGE IN EASTERN PLYMOUTH COUNTY, BUT THE HIGHER END OF THOSE TOTALS
SHOULD BE IN THE SOUTHERN PART OF THE COUNTY WHERE THERE'S JUST
ENOUGH TERRAIN ENHANCEMENT IN NORTHEAST FLOW OCEAN EFFECT SETUPS TO
GIVE TOTALS A MODEST BOOST. ACROSS THE CAPE AND ISLANDS, LOOKING FOR
A GENERAL 3-5 INCHES WITH PERHAPS NEAR A HALF-FOOT OVER THE OUTER
CAPE AND NANTUCKET. AS SNOW RATES SHOULD BE MANAGEABLE, THINK THIS
FITS MORE CLOSELY AS A WINTER WEATHER ADVISORY SETUP. THE SNOW ENDS
UP BEING WIND-DRIVEN WITH GUSTS IN THE 40-45 MPH RANGE OVER LAND;
THAT COULD MAKE THE SNOW REALLY DIFFICULT TO MEASURE. WE DON'T
EXPECT THE WIND TO LEAD TO ANY DAMAGE.
COASTAL FLOODING: THE THREE TIDES OF CONCERN SPECIFIC TO COASTAL
FLOODING ARE THE SUNDAY MORNING AND EVENING HIGH TIDES, AS WELL AS
THE MONDAY MORNING HIGH TIDE. ALTHOUGH IT STILL LOOKS LIKE THE STORM
SURGE PEAKS SUNDAY AFTERNOON WHICH COINCIDES WITH LOW TIDE, THE
PROSPECT OF LOWER STORM SURGE VALUES (1 - 2.5 FT, HIGHEST NEAR
NANTUCKET) WITH THE STORM CONTINUING TO PASS FURTHER SOUTHEAST COULD
LEAD TO LESSER TOTAL WATER LEVELS CORRESPONDING TO MORE MINOR
INUNDATION. STORM SURGE GUIDANCE FROM STEVENS INSTITUTE ALSO IS DOWN
FROM PREVIOUS RUNS, NOW MORE IN THE 1 TO 2 FT RANGE. BECAUSE OF
THAT, WE SIDED TOWARDS COASTAL FLOOD ADVISORIES FOR MINOR INUNDATION
AND SOME BEACH EROSION FOR THE EASTERN MA COAST EXCLUDING CAPE COD
AND THE ISLANDS. DIDN'T HAVE ENOUGH CONFIDENCE TO CONVERT THE CAPE
AND ISLANDS OVER TO AN ADVISORY OR WARNING, WANTING TO WAIT ANOTHER
SURGE MODEL CYCLE BEFORE MAKING THAT FINAL DETERMINATION. IT COULD
VERY WELL TURN INTO A MINOR WITH POCKETS OF MODERATE FLOODING,
PARTICULARLY FOR NANTUCKET.
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.
KEY MESSAGE 3: DRY WEATHER AND NOT AS COLD INTO THE MIDDLE OF NEXT
WEEK, THOUGH TURNS COLDER AND MORE ACTIVE LATE NEXT WEEK/EARLY
WEEKEND.
DRIER WEATHER WITH MODIFYING TEMPERATURES FROM THE FRIGID AIRMASS
WE'VE BEEN STUCK IN MUCH OF THIS WEEK, TO SOMETHING MORE CLOSELY
RESEMBLING SEASONABLE COLD. HIGHS COULD RETURN TO AROUND THE
FREEZING MARK THROUGH MIDWEEK. SOME MODEST SNOWMELT SHOULD TAKE
PLACE BUT THOSE MOUNDS OF SNOW WILL STILL BE AROUND. LATEST GUIDANCE
SEEMS TO INDICATE OUR NEXT CHANCE FOR SNOW COMES FROM AN ENERGETIC
CLIPPER SYSTEM IN WNW FLOW. ODDS FOR SIGNIFICANT SNOW ACCUMS FROM
THAT CLIPPER SYSTEM SEEMS LONG, AS IS TYPICAL FOR FAST-MOVING
CLIPPERS. COULD BE A PERIOD OF BREEZY CONDITIONS IN ITS PASSAGE, BUT
THAT ALSO WILL USHER IN ANOTHER SHOT OF BELOW NORMAL TEMPS AS WE
MOVE INTO NEXT WEEKEND.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE:
THROUGH TODAY: HIGH CONFIDENCE.
VFR. LIGHT WNW WINDS UNDER 10 KNOTS TODAY
TONIGHT: HIGH CONFIDENCE THRU 06Z, THEN MODERATE FOR THE EASTERN
TERMINALS.
VFR, THOUGH LAYER OF MVFR STRATUS STARTS TO TURN LANDWARD FROM
THE OCEAN WATERS ~06-09Z. PERIODIC BANDS OF OCEAN EFFECT SNOW
SHOWERS DEVELOP WITH MVFR VISBYS AROUND 09-11Z, WITH STEADIER
LIGHT SNOW STARTING TO BREAK OUT FOR THE CAPE AND ISLANDS.
WINDS TURN NE AND INCREASE IN SPEED TO 10-15 KT WITH GUSTS 20-25
KT.
VFR AND DRY WEATHER, BUT MVFR/VFR CIGS ARRIVE TOWARD
MORNING IN EASTERN MA.
SUNDAY/SUNDAY NIGHT: HIGH CONFIDENCE WESTERN TERMINALS, MODERATE
CONFIDENCE EASTERN TERMINALS.
MVFR-IFR WITH STEADY LIGHT SNOW (1-3 SM VISBY) ACROSS THE CAPE
TERMINALS AND ACK. A FEW INCHES OF ACCUMULATING SNOW LIKELY
LIMITED TO THOSE TERMINALS. INTERMITTENT OCEAN EFFECT SNOW AT
BOS WITH 4SM -SN INDICATED; GIVEN COLD PAVEMENT, SOME RUNWAY
ACCUM HERE BUT SNOW TOTALS AN INCH OR LESS. OCEAN EFFECT PRECIP
FOR BOS STARTS TO TAPER OFF AROUND 20Z AS WINDS START TO TURN
OFFSHORE.
VFR INLAND. NE WINDS 15-25 KT WITH GUSTS 25-40 KT, HIGHEST GUSTS
AT ACK; WINDS TURN NW WITH A DECREASE IN SPEED 21Z SUN-00Z
MON FROM WEST TO EAST. THIS COULD CAUSE AREAS OF
BLOWING/DRIFTING SNOW OFF EXISTING SNOWMOUNDS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF THRU SATURDAY.
LIGHT WNW WINDS TODAY AROUND 10 KNOTS. MVFR DEVELOPS AROUND 09Z,
WITH PERIODIC/INTERMITTENT OCEAN EFFECT SNOW SHOWERS BY 11Z.
LIMITED ACCUM (LESS THAN AN INCH) BUT PAVEMENT IS COLD SO IT
WILL STICK. NE WINDS INCREASE SUNDAY MORNING TO AROUND 15 KT
WITH GUSTS 28-30 KT.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
VFR. LIGHT WNW WINDS TODAY UNDER 10 KNOTS, BECOMING NORTH EARLY
SUNDAY AND INCREASING TO AROUND 10-13 KT WITH GUSTS 20-23 KT.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: VFR. STRONG WINDS WITH LOCAL GUSTS UP TO 45 KT.
MONDAY THROUGH MONDAY NIGHT: VFR. BREEZY.
TUESDAY THROUGH WEDNESDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
DIMINISHING WINDS AND SEAS TODAY AS HIGH PRESSURE BUILDS IN.
A POWERFUL OCEAN STORM WHICH TRACKS WELL SOUTH AND EAST OF THE
WATERS ON SUNDAY. POTENTIAL FOR HIGH END GALES TO LOW END STORM
FORCE NE GUSTS TO 40-50 KT OVER THE WATERS STARTING SUNDAY
MORNING. SEAS EXPECTED TO BUILD TO 15-20 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/SUN MORNING AND AGAIN SUN NIGHT.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: MODERATE RISK FOR GALE FORCE WINDS WITH GUSTS UP
TO 45 KT. ROUGH SEAS UP TO 19 FT. FREEZING SPRAY LIKELY, CHANCE
OF SNOW.
MONDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. ROUGH SEAS UP TO 16 FT. FREEZING SPRAY LIKELY.
MONDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
TUESDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...COLD WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
CTZ002>004.
MA...COLD WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MAZ002>019-026.
COASTAL FLOOD ADVISORY FROM 8 AM SUNDAY TO 2 PM EST MONDAY FOR
MAZ007-015-016-019.
WINTER WEATHER ADVISORY FROM 4 AM SUNDAY TO 4 AM EST MONDAY
FOR MAZ019-022>024.
COASTAL FLOOD WATCH FROM SUNDAY MORNING THROUGH MONDAY
AFTERNOON FOR MAZ022>024.
RI...COLD WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
RIZ001>004.
MARINE...GALE WARNING FROM 7 AM SUNDAY TO 1 AM EST MONDAY FOR ANZ230.
GALE WARNING FROM 4 AM SUNDAY TO 4 AM EST MONDAY FOR ANZ231-
232.
FREEZING SPRAY ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
SUNDAY FOR ANZ233>237-256.
GALE WARNING FROM 6 AM SUNDAY TO 1 AM EST MONDAY FOR ANZ233-
234.
GALE WARNING FROM 3 AM SUNDAY TO 1 AM EST MONDAY FOR ANZ235-
237-256.
GALE WARNING FROM 5 AM TO 11 PM EST SUNDAY FOR ANZ236.
GALE WARNING FROM 7 AM SUNDAY TO 4 AM EST MONDAY FOR ANZ250.
FREEZING SPRAY ADVISORY FROM 4 AM TO 1 PM EST SUNDAY FOR
ANZ251.
GALE WARNING FROM 6 AM SUNDAY TO 4 AM EST MONDAY FOR ANZ251.
STORM WARNING FROM 7 AM SUNDAY TO 4 AM EST MONDAY FOR ANZ254-
255.
DISCUSSION...LOCONTO/KP
AVIATION...LOCONTO/KP
MARINE...LOCONTO/KP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page