647
FXUS61 KBOX 250706
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
206 AM EST THU DEC 25 2025
WHAT HAS CHANGED
CHANCES FOR ACCUMULATING SNOWFALL INCREASED FRIDAY NIGHT INTO
SATURDAY DESPITE LOWER-THAN-NORMAL FORECAST CONFIDENCE.
KEY MESSAGES
- BREEZY WITH ISOLATED RAIN/SNOW SHOWERS TODAY. TEMPERATURES
FALL QUICKLY BELOW FREEZING THIS EVENING WITH WIND CHILL
VALUES NEAR OR BELOW ZERO OVERNIGHT.
- ACCUMULATING SNOW POSSIBLE FRIDAY NIGHT INTO SATURDAY MORNING.
UNCERTAINTY REMAINS HIGH, BUT THE BEST CHANCE FOR PLOWABLE
SNOW IS IN WESTERN CT/MA.
- STORM SYSTEM AROUND SUNDAY NIGHT INTO MONDAY COULD BRING
ACCUMULATING WINTRY MIX (SLEET/FREEZING RAIN) TO RAIN.
DISCUSSION
KEY MESSAGE 1... BREEZY WITH ISOLATED RAIN/SNOW SHOWERS TODAY.
TEMPERATURES FALL QUICKLY BELOW FREEZING THIS EVENING WITH WIND
CHILL VALUES NEAR OR BELOW ZERO OVERNIGHT.
NORTHERN STREAM SHORTWAVE DROPS OUT OF NORTHERN NEW ENGLAND THIS
MORNING, WITH A REINFORCING COLD FRONT FOLLOWING BEHIND THIS
AFTERNOON. THIS COULD LEAD TO A FEW ISOLATED SNOW SHOWERS THIS
MORNING INTO THE EARLY AFTERNOON BEFORE DRIER MIDLEVEL AIR ARRIVES
WITH THE COLD FRONT. NO SNOW ACCUMULATION ARE EXPECTED WITH THESE
SNOW SHOWERS. WINDS AHEAD OF THE COLD FRONT THIS MORNING WILL BE
LIGHT SOUTHWESTERLY, ALLOWING HIGH TEMPS TO TOP OUT NEAR 40F.
TEMPERATURES BEHIND THE COLD FRONT DROP QUICKLY, FALLING BELOW
FREEZING BY 5-6 PM TONIGHT. WINDS ALSO INCREASE BEHIND THE COLD
FRONT, GUSTING 25-35MPH, STARTING THIS AFTERNOON AND LASTING THROUGH
THE NIGHT. THE GUSTY WINDS WILL BRING THE WIND CHILL INDEX DOWN TO
NEAR OR BELOW ZERO OVERNIGHT. DECREASING WINDS AND COLD FRIDAY WITH
HIGHS IN THE LOW TO MID 20S ACROSS THE REGION.
KEY MESSAGE 2...ACCUMULATING SNOW POSSIBLE FRIDAY NIGHT INTO
SATURDAY MORNING. UNCERTAINTY REMAINS HIGH, BUT THE BEST CHANCE
FOR PLOWABLE SNOW IS IN WESTERN CT/MA.
A POSITIVELY TILTED SHORTWAVE AND ASSOCIATED SURFACE LOW DROPS OUT
OF THE GREAT LAKES ON FRIDAY AND MOVES TOWARDS THE NORTHEAST FOR
FRIDAY NIGHT INTO SATURDAY. 00Z GUIDANCE DIDN'T MAKE THE TRACK OF
THIS SYSTEM ANY CLEARER AS GLOBAL GUIDANCE SOURCES OF THE GFS AND
CANADIAN KEEP THE SOUTHERLY TRACK THROUGH PA AND INTO SOUTHERN NY,
WHILE THE NAM SWUNG FOR THE FENCES AND TAKES THIS SYSTEM THROUGH
CENTRAL NY AND INTO SNE. THE EURO ALSO SHIFTED THE TRACK SLIGHTLY
TO THE NORTH, BUT NOT TO THE EXTENT OF THE NAM. GIVEN THE LARGE
SPREAD IN THE LOW-PRESSURE TRACK, CONFIDENCE IN SNOW ACCUMULATION
REMAINS LOW. THE BEST CHANCE FOR PLOWABLE SNOW ACCUMULATION REMAINS
IN SW CT, WHERE ENSEMBLES SHOW A 50% PROBABILITY OF 3 INCHES OF
SNOW, DROPPING TO 10-20% IN EASTERN MA. HI-RES GUIDANCE ONLY ADDS
TO THE UNCERTAINTY AT THIS TIME, AS IT STILL FAVORS A MORE SOUTHERN
TRACK (OUTSIDE THE NAM-3K), WITH DRY AIR SHUTTING OUT MOST OF
SNE.
KEY MESSAGE 4...STORM SYSTEM AROUND SUNDAY NIGHT INTO MONDAY
COULD BRING ACCUMULATING WINTRY MIX (SLEET/FREEZING RAIN) TO
RAIN.
IN THE WAKE OF THE FRI NIGHT/SAT SYSTEM, THE LOWER-LEVEL AIRMASS
WARMS SUBSTANTIALLY AND BY SUN NIGHT BRINGS 850 MB TEMPS IN THE
+4 TO +6C RANGE. MODELS SHOW A MORE POTENT AND MOISTURE- LADEN
LOW PRESSURE EMBEDDED IN SWLY FLOW ALOFT WHICH LOOKS TO TRACK TO
OUR NORTH AND WEST SUN NIGHT, WITH SOME POTENTIAL FOR SECONDARY
LOW DEVELOPMENT BASED ON SOME BAGGINESS IN SEA-LEVEL ISOBARS
MON. THE STRENGTH OF THE LOWER-LEVEL WARMER AIR AS MENTIONED
ABOVE WOULD INSTEAD FAVOR SLEET/FREEZING RAIN AT LEAST AT OUTSET
IN MOST AREAS SUN NIGHT, AND THEN GRADUALLY TRANSITION TO PLAIN
RAIN; TIMING OF WHICH VARIES DEPENDING ON HOW QUICKLY SURFACE
TEMPS FROM SUNDAY NIGHT CAN MODIFY. WE TYPICALLY KEEP PRECIP
TYPES SIMPLE (RAIN OR SNOW) AT THIS EXTENDED RANGE, BUT FELT
THERE WAS ENOUGH CONFIDENCE IN THE WARM NOSE ALOFT TO INDICATE
WINTRY MIX IN THE FORECAST. TOO EARLY FOR SPECIFICS ON ACCUMS AT
THIS RANGE BUT THE POTENTIAL FOR AN ACCUMULATING ICE EVENT IS
POSSIBLE IN MOST AREAS, BUT ESPECIALLY SO FOR INTERIOR SNE N/W
OF I-95 WHICH OFTEN STRUGGLES TO SCOUR OUT COLDER AIR AS QUICKLY
AS BLENDED MODELS DEPICT.
AVIATION /07Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY...HIGH CONFIDENCE
VFR. SLIGHT CHANCE FOR SOME RAIN/SNOW SHOWERS OVER BOS AND
CAPE/ISLANDS TOMORROW MORNING. SHOWERS MAY BE ACCOMPANIED BY
BRIEF PERIODS OF MVFR VSBYS/CIGS. GREATEST RISK WOULD BE 12-18Z.
SOUTHWEST WINDS TO START, BUT SHIFTING TO NORTHWEST AFTER 18Z
WITH 25-30 KNOTS GUSTS LIKELY.
TONIGHT...HIGH CONFIDENCE
VFR. GUSTY NORTHWEST WINDS.
KBOS TERMINAL...HIGH CONFIDENCE
VFR. LOW CHANCE FOR A ISOLATED SNOW SHOWER IN THE MORNING.
BRIEF MVFR CIGS WOULD ACCOMPANY ANY SNOW SHOWERS. WINDS SHIFT NW
IN THE AFTERNOON AND GUST UP TO 30 KNOTS.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
VFR. WINDS SHIFT NW IN THE AFTERNOON AND GUST UP TO 25 KNOTS
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE SN.
SATURDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE SN.
SATURDAY NIGHT: VFR.
SUNDAY: VFR. SLIGHT CHANCE RA.
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. RA,
SN LIKELY.
MONDAY: MAINLY MVFR, WITH AREAS IFR POSSIBLE. WINDY WITH LOCAL
GUSTS UP TO 30 KT. RA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
CHRISTMAS DAY THROUGH FRIDAY
INCREASING SW WINDS THIS MORNING, TURNING NW THIS AFTERNOON WITH
GUSTS OF 25-35 KNOTS LASTING UNTIL DAYBREAK FRIDAY. SEAS REMAIN
ROUGH TODAY, AT 7-10 FEET OFFSHORE AND 3-5 FEET NEAR SHORE AND IN
THE SOUNDS. WINDS ON FRIDAY BECOME LIGHT NORTHWESTERLY AT 10-15
KNOTS, WITH SEAS DECREASING TO 2-5 FEET.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
FRIDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF SNOW. LOCAL VISIBILITY 1 NM OR LESS.
SATURDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF SNOW.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT.
SUNDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. RAIN LIKELY.
MONDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. AREAS OF ROUGH SEAS. RAIN.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 AM EST
FRIDAY FOR ANZ230-236.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR
ANZ231-232-250-251-254>256.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 AM EST FRIDAY
FOR ANZ233>235-237.
DISCUSSION...LOCONTO/KP
AVIATION...KP
MARINE...KP
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