581
FXUS61 KBOX 202350
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
650 PM EST TUE JAN 20 2026
WHAT HAS CHANGED
THERE HAVE BEEN NO SIGNIFICANT CHANGES SINCE THE LAST FORECAST
UPDATE.
KEY MESSAGES
-NEAR-NORMAL TO WARMER THAN NORMAL TEMPERATURES WED/THU AS A
WEAK CLIPPER THE SYSTEM BRINGS SOME HIGHER TERRAIN LIGHT SNOW
AND LIGHT RAIN FOR THE COASTAL PLAIN TOMORROW NIGHT
-ABOVE NORMAL TEMPS THURSDAY WITH GUSTY WINDS AT 30 TO 40MPH
-ARCTIC FRONT ARRIVES FRIDAY NIGHT, WITH DANGEROUS COLD AND WIND
CHILLS EXPECTED THIS WEEKEND AND POSSIBLY LASTING INTO NEXT
WEEK.
-WE CONTINUE TO MONITOR A POTENTIAL COASTAL STORM FOR LATE IN
THE WEEKEND, BUT CONFIDENCE REMAINS VERY LOW.
DISCUSSION
KEY MESSAGE 1...NEAR-NORMAL TO WARMER THAN NORMAL TEMPERATURES
WED/THU AS A WEAK CLIPPER THE SYSTEM BRINGS SOME HIGHER TERRAIN
LIGHT SNOW AND LIGHT RAIN FOR THE COASTAL PLAIN TOMORROW NIGHT
A MID-LEVEL RIDGE BUILDS OVERHEAD TONIGHT WITH AN AREA OF SURFACE
HIGH PRESSURE POSITIONED TO OUR SOUTH. THIS WILL SUPPORT A WIND
SHIFT TO THE SOUTHWEST OVERNIGHT WHICH WILL ALLOW WARMER AIR TO
ADVECT INTO THE REGION DURING THE DAY TOMORROW. AFTER A CHILLY START
TO WEDNESDAY WITH SINGLE DIGIT LOW TEMPERATURES, WARM ADVECTION AND
SOUTHWEST FLOW WILL ALLOW AFTERNOON TEMPERATURES TO APPROACH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPERATURES RANGING FROM THE UPPER 20S ACROSS
THE INTERIOR NORTHWEST TO THE UPPER 30S OVER SOUTHEAST MA AND THE
CAPE/ISLANDS.
MODELS CONTINUE TO RESOLVE A SUBTLE SHORT-WAVE ALOFT EMBEDDED IN
LARGER UPPER-LEVEL TROUGH MOVING OVERHEAD TOMORROW NIGHT.
POSITIVE VORTICITY ADVECTION IN CONJUNCTION WITH LOW-LEVEL WARM AIR
ADVECTION WILL SUPPORT A PERIOD OF LIGHT SNOW SHOWERS FOR MUCH OF
THE INTERIOR/HIGH TERRAIN. MOISTURE WILL BE VERY LIMITED WITH PWATS
ONLY BETWEEN 0.25-04". NOT EXPECTING ANY SIGNIFICANT ACCUMULATIONS
WITH ONLY A DUSTING TO AN INCH TOMORROW NIGHT.
AREAS FURTHER SOUTH AND EAST MORE LIKELY TO SEE SOME SPOTTY RAIN
SHOWERS.
KEY MESSAGE 2...ABOVE NORMAL TEMPS THURSDAY WITH GUSTY WINDS AT
30 TO 40MPH
THURSDAY WILL LIKELY BE OUR LAST MILD DAY FOR THE FORESEEABLE
FUTURE, BEFORE AN ARCTIC AIRMASS MOVES IN THIS WEEKEND. MID-LEVEL
RIDGE AND LIGHT WAA ALLOW 850 MB TEMPS TO WARM TO -5C, WHICH WILL
TRANSLATE INTO HIGHS IN THE LOW TO MID 40S. THURSDAY WILL BE VERY
BREEZY AS STRONG WESTERLIES DEVELOP DUE TO A TIGHT PRESSURE GRADIENT
BETWEEN HIGH PRESSURE OVER THE ATLANTIC AND LOW PRESSURE OVER THE
GREAT LAKES. BUFKIT SOUNDINGS SHOW A FAIRLY DEEP MIXED LAYER UP TO
800 MB, WHERE WINDS ARE AROUND 35-45MPH. GUSTS OF 30-40MPH SHOULD
BE ABLE TO MIX DOWN TO THE SURFACE DURING THE PEAK HEATING HOURS IN
THE AFTERNOON.
KEY MESSAGE 3...ARCTIC FRONT ARRIVES FRIDAY NIGHT, WITH
DANGEROUS COLD AND WIND CHILLS EXPECTED THIS WEEKEND AND
POSSIBLY LASTING INTO NEXT WEEK.
ARCTIC FRONT ARRIVES ON FRIDAY WITH HIGHS LIKELY PEAKING IN THE
UPPER 20S TO LOW 30S EARLY IN THE DAY BEFORE PLUNGING TO NEAR ZERO
BY FRIDAY NIGHT. THE ARCTIC FRONT WILL BRING CONTINUED GUSTY WINDS,
WITH NW GUSTS OF 30-40MPH ONCE AGAIN IN THE AFTERNOON, AND REMAINING
GUSTY OVERNIGHT. THIS WILL BRING THE WINDCHILL INDEX/FEELS-LIKE
TEMPERATURE INTO THE SINGLE DIGITS FOR FRIDAY AFTERNOON AND INTO THE
NEGATIVE TEENS TO TWENTIES FOR FRIDAY NIGHT. HIGH TEMPERATURES ON
SATURDAY WILL LIKELY BE THE COLDEST OF THE SEASON THUS FAR, WITH
HIGHS ONLY TOPPING OUT IN THE SINGLE DIGITS TO LOW TEENS. IT WILL BE
LESS WINDY ON SATURDAY WITH NW WINDS GUSTING 15-20MPH; HOWEVER, THIS
WILL KEEP THE WIND CHILL INDEX IN THE -10 TO -20 RANGE. WINDS
FINALLY LOOK TO DIMINISH ON SATURDAY NIGHT AS THE CENTER OF THE
ARCTIC HIGH MOVES OVERHEAD; HOWEVER, THIS WILL SET THE STAGE FOR
GOOD RADIATIONAL COOLING CONDITIONS, ALLOWING LOW TEMPERATURES TO
DROP NEAR OR BELOW ZERO BY SUNDAY MORNING. NOT MUCH RELIEF FROM THE
COLD ON SUNDAY AS HIGHS REMAIN WELL BELOW NORMAL IN THE LOW TEENS
AND WIND CHILLS STILL NEAR OR BELOW ZERO. WIND CHILLS BELOW -15 CAN
CAUSE FROSTBITE IN AS LITTLE AS 30 MINUTES ON EXPOSED SKIN, SO USE
CAUTION IF SPENDING TIME OUTDOORS THIS WEEKEND, ESPECIALLY AT NIGHT.
COLD WEATHER LOOKS TO CONTINUE INTO NEXT WEEK, AS CPC CONTINUES TO
HIGHLIGHT MUCH OF THE NORTHEAST IN A MODERATE RISK FOR WELL BELOW-
NORMAL TEMPERATURES.
KEY MESSAGE 4...WE CONTINUE TO MONITOR A POTENTIAL COASTAL
STORM FOR LATE IN THE WEEKEND, BUT CONFIDENCE REMAINS VERY LOW.
GUIDANCE CONTINUES TO INDICATE A POTENTIAL COASTAL LOW SOMETIME
BETWEEN SUNDAY AND MONDAY. THERE IS STILL SIGNIFICANT UNCERTAINTY
WITH THIS SYSTEM, AS BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE ARE
VERY SPREAD OUT ALONG ITS PATH, AS IT COULD TRAVEL UP THE COAST OR
OUT TO SEA AS IT EXITS THE MID-ATLANTIC. WITH A TRACK OUT TO SEA,
SNOW IMPACTS WOULD BE LITTLE TO NONE; HOWEVER, IF THIS SYSTEM
APPROACHES THE 40/70 BENCHMARK AND TRAVELS UP THE COAST, THERE WOULD
BE MORE SIGNIFICANT SNOW IMPACTS, ESPECIALLY WITH COLD AIR ALREADY
IN PLACE. THE PROBABILISTIC WINTER STORM SEVERITY INDEX SHOWS A 20-
30% CHANCE FOR MAJOR WINTER STORM IMPACTS SUNDAY INTO MONDAY.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT: HIGH CONFIDENCE.
VFR. WEST WINDS DECREASING TO 5-10 KNOTS.
WEDNESDAY: HIGH CONFIDENCE.
VFR. SOUTHWEST WINDS 5-10 KNOTS.
WEDNESDAY NIGHT: MODERATE CONFIDENCE.
INCREASING MID-LEVEL CLOUDINESS. LOW-END MVFR CLOUD BASES
AROUND 3000 FEET POSSIBLE. SCATTERED -SN.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE
IN TIMING.
VFR. GUSTY W WINDS AROUND 20 KTS DECREASING TONIGHT TO 5-10
KTS. BRIEF -SN POSSIBLE WEDNESDAY AFTERNOON WITH LITTLE TO NO
ACCUMULATION EXPECTED.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE
IN TIMING.
VFR. W WINDS 5-10 KTS TURN SW WEDNESDAY MORNING. -SN POSSIBLE
WEDNESDAY AFTERNOON WITH LITTLE TO NO ACCUMULATION EXPECTED.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY: VFR. WINDY WITH GUSTS UP TO 30 KT.
THURSDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
FRIDAY THROUGH SATURDAY: VFR. BREEZY.
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.
TONIGHT THROUGH WEDNESDAY NIGHT
SCY CRITERIA PERSISTS THROUGH ABOUT MIDNIGHT BEFORE WINDS DIMINISH
AND SEAS SUBSIDE BELOW SCY LEVELS. THIS WILL BE IN RESPONSE TO HIGH
PRESSURE BUILDING SOUTH OF THE COASTAL WATERS. A BRIEF PERIOD OF
CALMER CONDITIONS TOMORROW MORNING AND AFTERNOON BEFORE BEFORE
SOUTHWEST WINDS KICK BACK UP TO SCY CRITERIA WEDNESDAY NIGHT INTO
THURSDAY. INCREASING WINDS ON THURSDAY AS WELL, POSSIBLY REACH GALE
FORCE FOR THE OUTER WATERS BY THURSDAY EVENING.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. SLIGHT CHANCE OF RAIN.
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. CHANCE OF FREEZING SPRAY, SLIGHT CHANCE OF SNOW.
SATURDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. LOCAL ROUGH SEAS. CHANCE OF FREEZING SPRAY,
SLIGHT CHANCE OF SNOW.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE
OF SNOW, CHANCE OF FREEZING SPRAY.
SUNDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. SEAS UP TO 5 FT. CHANCE OF SNOW, CHANCE OF FREEZING
SPRAY. VISIBILITY 1 NM OR LESS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ230-
231-236-251.
SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ232>235-
237.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR ANZ250-
254>256.
DISCUSSION...KP/RM
AVIATION...MCMINN
MARINE...RM
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