591
FXUS61 KBOX 210653
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
153 AM EST WED JAN 21 2026
WHAT HAS CHANGED
BIGGEST QUESTION OF THE FORECAST PERIOD IS HOW MUCH IMPACT THE LATE
WEEKEND/EARLY NEXT WEEK WINTER STORM BRINGS TO SNE. SNOW IS LOOKING
INCREASINGLY LIKELY BUT DETAILS REMAIN UNCERTAIN 4+ DAYS OUT FROM
THIS SYSTEM.
KEY MESSAGES
- A WEAK CLIPPER SYSTEM BRINGS SOME LIGHT SNOW TO THE HIGHER TERRAIN
AREAS AND LIGHT RAIN FOR THE COASTAL PLAIN TONIGHT.
-TEMPERATURES SURGE ABOVE NORMAL THURSDAY WITH GUSTY WINDS 25-35
MPH.
- ARCTIC FRONT ARRIVES FRIDAY NIGHT, WITH DANGEROUS COLD AND WIND
CHILLS EXPECTED THIS WEEKEND AND INTO NEXT WEEK.
- A LATE- WEEKEND COASTAL STORM COULD BRING IMPACTFUL SNOW TO
SOUTHERN NEW ENGLAND SUNDAY INTO MONDAY BUT CONFIDENCE IN DETAILS IS
LOW.
DISCUSSION
KEY MESSAGE 1...A WEAK CLIPPER SYSTEM BRINGS SOME LIGHT SNOW TO
THE HIGHER TERRAIN AREAS AND LIGHT RAIN FOR THE COASTAL PLAIN
TONIGHT.
HIGH PRESSURE TO OUR SOUTH MOVES OFFSHORE TODAY AND AN UPPER-LEVEL
TROUGH MOVES THROUGH NEW ENGLAND THIS AFTERNOON. WINDS SHIFTING TO
THE SOUTHWEST ON THE BACKSIDE OF THE HIGH WILL BRING A SURGE OF
SLIGHTLY WARMER, MORE MOIST AIR. THIS NEW AIRMASS COMBINING WITH THE
UPPER-LEVEL TROUGH WILL INITIATE A FEW HOURS IN THE EVENING OF LIGHT
SNOW SHOWERS ACROSS THE INTERIOR. SNOWFALL WILL BE LIGHT IN NATURE
WITH SNOW TOTALS OF A COATING TO AN INCH IN THE HIGHER TERRAIN
AREAS. AREAS FURTHER SOUTH AND EAST WILL HAVE SLIGHTLY ELEVATED
TEMPERATURES COMPARED TO THE INTERIOR, AND WILL MOST LIKELY SEE RAIN
SHOWERS INSTEAD OF SNOW.
KEY MESSAGE 2...TEMPERATURES SURGE ABOVE NORMAL THURSDAY WITH
GUSTY WINDS 25-35 MPH.
CONTINUED SOUTHWESTERLY FLOW AND WARM AIR ADVECTION HELPS WARM 850
MB TEMPERATURES TO -2C TO -5C AND 925 MB TEMPERATURES TO NEAR 0C
THURSDAY AND ALLOWS SURFACE TEMPERATURES TO SURGE ABOVE NORMAL...
AFTERNOON HIGHS IN THE UPPER 30S IN THE HIGHER TERRAIN TO LOW 40S IN
THE COASTAL PLAIN. THE PRESSURE GRADIENT BEGINS TO TIGHTEN AS
ANOTHER LOW PRESSURE SYSTEM MOVE THROUGH THE GREAT LAKES AND HIGH
PRESSURE STALLS OVER THE ATLANTIC OCEAN. WINDS WILL PICK UP DURING
THE AFTERNOON HOURS AS THE LAND RAPIDLY WARMS... EXPECTING GUSTS TO
INCREASE TO 25-35MPH THROUGH THE AFTERNOON.
KEY MESSAGE 3...ARCTIC FRONT ARRIVES FRIDAY NIGHT, WITH DANGEROUS
COLD AND WIND CHILLS EXPECTED THIS WEEKEND AND INTO NEXT WEEK.
AFTER A WARM THURSDAY, FRIDAY WILL BE QUITE THE TRANSITION INTO THE
COLDEST WEEKEND OF THE WINTER. THIS COMES THANKS TO A DRY ARCTIC
FRONT WHICH SWEEPS THROUGH SNE ON FRIDAY. TEMPERATURES SHOULD MAKE
IT INTO THE UPPER 20S AND LOW 30S FOR A TIME ON FRIDAY BEFORE
PLUMMETING INTO THE SINGLE DIGITS ON EITHER SIDE OF 0. THIS AIRMASS
IS UNUSUALLY COLD, WITH 850 MB TEMPS AS COLD AS -25 TO -30 C AND THE
AFOREMENTIONED LOW TEMPS 3 SDS BELOW AVERAGE FOR LATE JANUARY. THIS
IS DANGEROUS COLD, ESPECIALLY WHEN COMBINED WITH THE STRONG LLJ
OVERHEAD WHICH MODEL SOUNDINGS SUGGEST WILL MIX DOWN VERY
EFFICIENTLY IN THE STRONG CAA. AT THE MOMENT GUSTS 30-40 MPH ARE
MOST LIKELY, WHICH WOULD MAKE TEMPERATURES SATURDAY MORNING FEEL
LIKE -10 TO -20 F IN THE HIGH TERRAIN, -5 TO -15 EVERYWHERE ELSE.
THIS WILL LIKELY NECESSITATE SOME COLD WEATHER ADVISORIES, WITH
EXTREME COLD WARNINGS MORE THAN LIKELY CONTAINED TO THE HIGHEST
TERRAIN OF THE BERKSHIRES. THOUGH SATURDAY MORNING WILL BE THE
COLDEST PERIOD OF THIS STRETCH OF BELOW NORMAL TEMPERATURES, THE
UNUSUAL COLD IS STICKING AROUND INTO THE BEGINNING OF NEXT WEEK.
HIGHS ON SATURDAY WILL BE IN THE SINGLE DIGITS TO MID TEENS, WARMING
TO THE TEENS/MID 20S SUNDAY AND MONDAY.
KEY MESSAGE 4...A LATE- WEEKEND COASTAL STORM COULD BRING IMPACTFUL
SNOW TO SOUTHERN NEW ENGLAND SUNDAY INTO MONDAY BUT CONFIDENCE IN
DETAILS IS LOW.
AFTER THE DANGEROUS COLD ATTENTION TURNS TO A LATE WEEKEND STORM
THAT HAS MOST OF THE EASTERN HALF OF THE COUNTRY'S ATTENTION AT THIS
POINT. THIS EXCEPTIONAL OUTBREAK OF COLD COINCIDING WITH A LARGE
HIGH PRESSURE ANCHORED OVER THE NORTHERN TIER OF THE COUNTRY
TOGETHER WITH A FRONTAL ZONE AND PLUME OF SUBTROPICAL MOISTURE WILL
BRING SNOW AND ICE FROM THE SOUTHEAST U.S. INTO THE MID ATLANTIC
SAT/SUN AND THEN HAS THE POTENTIAL TO BRING IMPACTFUL SNOWFALL TO
NEW ENGLAND SUNDAY INTO MONDAY. THIS, AS A SURFACE LOW FORMS ALONG
THE FRONTAL BOUNDARY DEEPENING AS IT PASSES OFF THE EASTERN
SEABOARD. GIVEN THIS STORM IS OVER 4 DAYS FROM ITS ANTICIPATED
ARRIVAL IN SNE IT'S NOT UNUSUAL FOR THERE TO BE SIGNIFICANT QUESTION
AS TO THE DETAILS, WHICH IS INDEED THE CASE HERE. IT WILL BE
PARTIALLY DEPENDENT ON THE EVENTUAL TRACK OF THE SURFACE LOW. A PASS
NEAR THE 70/40 BENCHMARK WOULD BE MOST IMPACTFUL FOR THE I-95
CORRIDOR WITH LESSER IMPACT IF IT PASSES FURTHER SOUTH. A LOOK AT
ENSEMBLE MEMBER LOW LOCATIONS IN THE EPS AND GEFS SHOWS AN EXTREMELY
WIDE SPREAD IN THE ENVELOPE OF POSSIBLE TRACKS WITH INDIVIDUAL
MEMBERS DEPICTING SNOW TOTALS FROM A FEW INCHES TO 10+. LATEST MODEL
RUNS INDICATE AT 40-60% CHANCE OF AOA 6" OF SNOW. FOR NOW, SUFFICE
TO SAY THE BETTER CHANCE OF MAJOR IMPACTS REMAINS TO OUR SOUTHWEST,
BUT WE ARE IN PLAY FOR THAT POTENTIAL AS WELL. STAY TUNED.
AVIATION /06Z WEDNESDAY THROUGH SUNDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY: HIGH CONFIDENCE.
VFR. SOUTHWEST WINDS 5-10 KNOTS.
TONIGHT: MODERATE CONFIDENCE.
INCREASING MID-LEVEL CLOUDINESS. LOW-END MVFR CLOUD BASES
AROUND 3000 FEET POSSIBLE WITH SCATTERED -SN ARRIVING AS EARLY
AT 00-03Z, FROM WEST TO EAST, AND -RA FOR THE CAPE/ISLANDS.
THURSDAY: HIGH CONFIDENCE.
-SN/-RA MOVES OUT AFTER MIDNIGHT. CONDITIONS IMPROVE TO VFR WITH
SW WINDS GUSTING UP TO 25 KTS.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE
IN TIMING.
VFR. SW WIND 5-10 KTS. BRIEF -SN POSSIBLE WEDNESDAY AFTERNOON
WITH LITTLE TO NO ACCUMULATION EXPECTED. CONDITIONS MAY
DETERIORATE TO MVFR UNDER SNOW SHOWERS.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE
IN TIMING.
VFR. SOUTHERLY WINDS 5-10 KTS. -SN POSSIBLE WEDNESDAY AFTERNOON
WITH A COATING TO HALF INCH POSSIBLE. CONDITIONS MAY DETERIORATE
TO MVFR UNDER SNOW SHOWERS.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
THURSDAY NIGHT: VFR. BREEZY.
FRIDAY: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
FRIDAY NIGHT: VFR. WINDY WITH GUSTS UP TO 30 KT.
SATURDAY: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
SATURDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SN.
SUNDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. CHANCE SN.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH THURSDAY...
HIGH PRESSURE MOVES TO THE SOUTH OF THE COASTAL WATERS TODAY, AND
CONDITIONS CALM BRIEFLY TODAY. SOUTHWESTERLY WINDS INCREASE TONIGHT
TO ABOVE 25 KNOTS ACROSS THE OUTER WATERS AND PERSIST THROUGH
THURSDAY. SEAS SUBSIDE TO BELOW 5 FEET TODAY, BUT BEGIN TO BUILD
ONCE AGAIN TONIGHT. SEAS FURTHER BUILD THURSDAY TO 5-8 FEET ACROSS
THE OUTER WATERS.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
THURSDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.
FRIDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. SEAS UP TO 5 FT.
FRIDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 35 KT. AREAS OF
ROUGH SEAS. FREEZING SPRAY, SLIGHT CHANCE OF SNOW.
SATURDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
AREAS OF GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. FREEZING
SPRAY, SLIGHT CHANCE OF SNOW.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. FREEZING SPRAY, CHANCE OF SNOW.
SUNDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
FREEZING SPRAY, CHANCE OF SNOW. VISIBILITY 1 NM OR LESS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
THURSDAY FOR ANZ232-233-235-237.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ250-
254>256.
DISCUSSION...BW/MCMINN
AVIATION...BW/MCMINN
MARINE...BW/MCMINN
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