488
FXUS61 KBOX 290037
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
737 PM EST SUN DEC 28 2025
WHAT HAS CHANGED
WINTER WEATHER ADVISORY EXPANDED TO INCLUDE SW RI, EASTERN KENT
AND SE PROVIDENCE COUNTIES IN RI AS WELL AS NORTHERN BRISTOL
AND NORTHERN PLYMOUTH COUNTIES IN SE MA. NO CHANGE TO POTENTIAL
STRONG WINDS LATE MONDAY NIGHT AND TUESDAY. WIND ADVISORIES MAY
BE NEEDED FOR AT LEAST THE HIGH TERRAIN AND CAPE/ISLANDS.
KEY MESSAGES
- A PERIOD OF FREEZING RAIN TONIGHT WILL BRING A TENTH TO A QUARTER
INCH OF ICE ACCUMULATION TO INTERIOR MA AND PORTIONS OF NORTHERN
CT, WITH A TRACE TO A TENTH OF AN INCH ELSEWHERE AWAY FROM THE
SOUTH COAST.
- RAIN TAPERS OFF LATE MONDAY, THEN WINDY AND TURNING MUCH
COLDER MON NIGHT
- STRONG GUSTY WINDS BEGIN EARLY TUESDAY MORNING, PEAKING LATE
MORNING THROUGH EARLY AFTERNOON.
- BELOW NORMAL TEMPERATURES CONTINUE THROUGH LATE WEEK. PERIODS OF
LIGHT SNOW POSSIBLE.
DISCUSSION
KEY MESSAGE 1...FREEZING RAIN TONIGHT
THE STAGE IS SET FOR A PERIOD OF ICING TONIGHT AS SHALLOW COLD AIR
WILL BE SLOW TO DISLODGE AS MOISTURE MOVES INTO THE REGION WITH
PRETTY MILD TEMPS ALOFT. MID LEVEL SHORTWAVE AND WARM FRONT
APPROACHES FROM WEST WITH A MODEST LOW LEVEL JET DEVELOPING AHEAD OF
THE SHORTWAVE. THIS WILL ADVECT ANOMALOUS PWATS INTO SNE WITH STRONG
CONVERGENCE AT THE NOSE OF THE JET ACTING ON THIS MOISTURE TO BRING
WIDESPREAD RAIN TO SNE, BEGINNING 8-11 PM FROM WEST TO EAST. TEMPS
ARE EXPECTED TO FALL BACK INTO THE 20S THIS EVENING AND MAY WET BULB
FURTHER AS PRECIP MOVES IN GIVEN DEWPOINTS IN THE TEENS. SOUNDINGS
IN THE INTERIOR SHOW A CLASSIC FREEZING RAIN SITUATION WITH
PRONOUNCED WARM NOSE ABOVE 2K FT AND SHALLOW LOW LEVEL COLD AIR
BELOW 2K FT AS PRECIP MOVES IN. THIS WILL ENSURE A PERIOD OF
WIDESPREAD FREEZING RAIN IN THE INTERIOR TONIGHT BUT TEMPS WILL BE
RISING FROM LATE EVENING THROUGH THE OVERNIGHT WHICH WILL ALLOW ICE
TO GRADUALLY TRANSITION TO PLAIN RAIN, BUT IT MAY TAKE UNTIL MON
MORNING ACROSS PORTIONS OF FAR NORTHERN MA WHERE SHALLOW COLD AIR
WILL HANG ON THE LONGEST. IN THE COASTAL PLAIN INCLUDING THE BOSTON
TO PROVIDENCE CORRIDOR, WE DO EXPECT A BRIEF PERIOD OF ICING AS
TEMPS WILL BE NEAR 32F AS PRECIP DEVELOPS AND EVEN IF TEMPS ARE
SLIGHTLY ABOVE FREEZING RAIN FALLING ON COLD GROUND WILL SUPPORT
PATCHY LIGHT ICING. FOR THIS REASON WE EXPANDED THE WINTER WEATHER
ADVISORY TO INTERIOR SW RI AND THE PVD-TAN-PYM CORRIDOR. ANY ICING
HERE WILL BE BRIEF AND NOT EXPECTED TO BE WIDESPREAD AS TEMPS IN THE
COASTAL PLAIN WILL QUICKLY RISE THROUGH THE 30S OVERNIGHT AND INTO
THE 40S BY DAYBREAK. NOT EXPECTING ANY ICING ALONG THE
IMMEDIATE SOUTH COAST AND CAPE AND ISLANDS. THE HIGHEST ICE
ACCRETION WILL BE ACROSS INTERIOR MA AND CT, MAINLY NORTH AND
WEST OF I-84 TO I-90 TO I-495 CORRIDOR WHERE 0.10 TO 0.25" OF
ICE IS POSSIBLE, AND WE LEANED TOWARD HREF WHICH USED MORE
RELIABLE FRAM METHOD. IF ICE ACCRETION EXCEEDS 0.25" THERE COULD
BE SOME LOCALIZED TREE DAMAGE AND THE BEST CHANCE OF 0.25" ICE
WOULD BE ACROSS THE NORTHERN BERKSHIRES AND ADJACENT CT VALLEY.
ELSEWHERE NORTH OF PVD-TAN-PYM WE ARE EXPECTING A TRACE TO LESS
THAN 0.10" OF ICE. ANY ICING IMPACTS TO THE MORNING COMMUTE
WOULD BE CONFINED TO AREAS IN FAR NORTHERN MA.
KEY MESSAGE 2...RAIN TAPERING OFF LATE MON, THEN WINDY AND MUCH
COLDER MON NIGHT
BRIEF DRY SLOT MOVES IN BY DAYBREAK WHICH WILL ALLOW RAIN TO BE MORE
SPOTTY IN THE MORNING. THERE IS A LOW RISK FOR BRIEF SPOTTY FREEZING
RAIN IN THE MORNING IN PORTIONS OF FAR NORTHERN MA NEAR THE VT AND
NH BORDER WHERE LOW LEVEL COLD AIR MAY BE SLOW TO DISLODGE. IF THERE
IS ANY ICING AFTER DAYBREAK IT WILL TRANSITION TO PLAIN RAIN BY MID
OR LATE MORNING. OTHERWISE, WE ARE EXPECTING ANOTHER PULSE OF RAIN
MOVING WEST TO EAST ACROSS SNE WITH THE COLD FRONT AND MID LEVEL
SHORTWAVE. TEMPS WILL WARM INTO THE 40S WITH POTENTIAL FOR LOWER 50S
RI AND SE MA. THE COLD FRONT WILL BE MOVING THROUGH THE REGION
DURING THE MID TO LATE AFTERNOON WITH RAIN TAPERING OFF AFTER THE
FROPA AS MUCH DRIER AIR MOVES IN FROM THE WEST. SOME UPSLOPE SNOW
SHOWERS MAY SPILL OVER INTO THE EAST SLOPES OF BERKSHIRES MON NIGHT,
OTHERWISE CLEARING SKIES. STRONG ADVECTION AND AN INCREASINGLY MIXED
BOUNDARY LAYER WILL RESULT IN GUSTY W WINDS DEVELOPING MON NIGHT
WITH 30-40 MPH GUSTS, EXCEPT POTENTIAL FOR 40-50 MPH GUSTS IN THE
INTERIOR MA HIGHER TERRAIN AND CAPE/ISLANDS WHERE WIND ADVISORIES
MAY EVENTUALLY BE NEEDED. 850 MB TEMPS BOTTOM OUT AROUND -14 TO -18C
MON MORNING. LOWS BY MON MORNING WILL DROP TO MID TEENS TO LOWER 20S
BUT WIND CHILLS MON MORNING WILL BOTTOM OUT NEAR 10F IN THE COASTAL
PLAIN, SINGLE NUMBERS INTERIOR AND ZERO TO -5F IN THE BERKSHIRES AND
WORCESTER HILLS.
KEY MESSAGE 3...STRONG GUSTY WINDS BEGIN EARLY TUESDAY MORNING,
PEAKING LATE MORNING THROUGH EARLY AFTERNOON.
A COLD FRONT MOVES THROUGH LATE MONDAY NIGHT INTO EARLY TUESDAY
MORNING WITH CONSIDERABLY COLDER AIR PUSHING IN BEHIND IT. HIGH
PRESSURE WILL BUILD IN FROM THE SOUTH ON TUESDAY AS LOW PRESSURE
EXITS. STRONG CAA PAIRED WITH A TIGHT PRESSURE GRADIENT AND FAIRLY
STRONG LLJ JET RAISES THE CONCERN FOR EFFICIENT MIXING OF GUSTY
WINDS DOWN TO THE SURFACE. PER LATEST MODEL GUIDANCE, THERE IS
INCREASING AGREEMENT ON A STRONGER 850MB JET (45-55 KTS) COMPARED TO
YESTERDAY. MODEL SOUNDINGS ARE SUPPORTIVE OF THE STRONG GUST
POTENTIAL INDICATING MIXING FROM AROUND 850 MB. ENSEMBLES CONTINUE
TO DISPLAY A RANGE OF 35-55 MPH GUSTS. QUITE A RANGE...HOWEVER THIS
REFLECTS THE CURRENT SPREAD AMONG ENSEMBLE/DETERMINISTIC
GUIDANCE. GFS AND CANADIAN HAVE LEANED ON THE LOWER END WHILE
THE ECMWF/ENS LEANED HIGHER. THE HIGHER GUSTS IN THAT RANGE WILL
BE MORE LIKELY OVER THE HIGHER TERRAIN AND NEAR THE
CAPE/ISLANDS.
NBM PROBABILITIES HAVE BEEN CONSISTENTLY IN THE 60-80% RANGE
FOR GUSTS GREATER THAN 45 MPH (ADVISORY CRITERIA) FOR THE HIGH
TERRAIN (BERKSHIRES, WORCESTER HILLS) AND AROUND THE
CAPE/ISLANDS. PROBABILITIES ARE LOWER ELSEWHERE (< 35%);
HOWEVER, WE ARE KEEPING IN MIND NBM HAS RUN LOW ON GUSTS IN
PREVIOUS WIND EVENTS THIS SEASON. OTHER GUIDANCE HAS SHOWN
HIGHER PROBABILITIES. BOTH THE NBM AND ECMWF ENS HIGHLIGHT
POTENTIAL FOR GUSTS NEAR HIGH WIND WARNING CRITERIA FOR THE
BERKSHIRES/IMMEDIATE EAST SLOPE OF BERKSHIRES WITH EVEN LOW
PROBS IN THE WORCESTER HILLS AND NEAR THE CAPE/ISLANDS. THIS
SEEMS REASONABLE AT LEAST FOR THE HIGHER TERRAIN. THE WESTERLY
COMPONENT FLOW MAY SUPPORT DOWNSLOPE ENHANCEMENT AS WELL IN THE
BERKSHIRES. WIND ADVISORIES WILL LIKELY BE NEEDED WITH THE
HIGHEST CONFIDENCE FOR THE INTERIOR HIGH TERRAIN AND
CAPE/ISLANDS. A HIGH WIND WARNING IS ALSO NOT OUT OF THE
QUESTION FOR AT LEAST THE EAST SLOPE OF THE BERKSHIRES.
CONFIDENCE WILL INCREASE AS WE GET IN FUTURE MODEL GUIDANCE,
INCLUDING FROM HIGH-RESOLUTION MODELS.
TEMPERATURES WILL ALSO BE BELOW NORMAL TUESDAY IN THE 20S IN MOST
SPOTS. THE GUSTY WEST WINDS WILL BRING WIND CHILLS IN THE SINGLE
DIGITS TO TEENS DURING THE DAY TUESDAY.
MID-LEVEL MOISTURE WILL BE PRESENT ON TUESDAY WITH STEEP LAPSE
RATES/MARGINAL INSTABILITY. COMBINED WITH ENHANCED WESTERLY FLOW,
THIS SHOULD BE ENOUGH BRING A FEW STREAMERS/SHOWERS FROM THE GREAT
LAKES INTO WESTERN MA. CAN'T RULE OUT AN ISOLATED SNOW SHOWER OR
FLURRY FOR SOUTHERN NEW ENGLAND WITHIN THE COLD ADVECTIVE REGIME.
KEY MESSAGE 4...BELOW NORMAL TEMPERATURES CONTINUE THROUGH LATE
WEEK. PERIODS OF LIGHT SNOW POSSIBLE LATE WEEK.
THERE IS GOOD AGREEMENT AMONG ENSEMBLE GUIDANCE FOR CONTINUED MID-
LEVEL TROUGHING ACROSS THE NORTHEAST THROUGH LATE WEEK. ACCOMPANIED
BY COLD TEMPERATURES ALOFT, THIS WILL SUPPORT BELOW NORMAL
TEMPERATURES IN THE 20S TO LOW 30S THROUGH THE WEEKEND. THERE IS A
SIGNAL FOR ANOTHER SHOT OF COLDER AIR FOR THURSDAY AND FRIDAY WITH
HIGHS STRUGGLING TO MAKE IT OUT OF THE 20S.
A FEW OCEAN-EFFECT SHOWERS ARE POSSIBLE WEDNESDAY NEAR THE CAPE COD
/ISLANDS. THERE MAY BE A FEW SYSTEMS THAT MOVE THROUGH THE FLOW
LATER IN THE WEEK; HOWEVER, CONFIDENCE REMAINS LOW FOR PRECIP
PROBABILITIES/TIMING DUE TO MODEL VARIANCE. FIRST CHANCE COMES WITH
THE PASSAGE OF THE ARCTIC FRONT LATE WEDNESDAY-THURSDAY AM. NEXT
CHANCE WILL BE WITH AN OFFSHORE SYSTEM. THIS MAY BRING A PERIOD OR
TWO OF LIGHT SNOW FALL LATE WEDNESDAY THROUGH FRIDAY.
AVIATION /00Z MONDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
00Z TAF UPDATE:
TONIGHT AND MONDAY: HIGH CONFIDENCE IN TRENDS BUT MODERATE ON
TIMING THE CHANGEOVER FROM FZRA TO RA.
MVFR CEILINGS/VISBYS DEVELOP BETWEEN 01-03Z MON WITH 3-6 SM
-FZRA. BEST CHANCE FOR ICY UNTREATED RUNWAYS ARE ACROSS THE
INTERIOR AND AWAY FROM THE SOUTH COAST AND CAPE COD, WHERE RA
SHOULD PREDOMINATE. GRADUAL TRANSITION FROM FZRA TO RA TAKES
PLACE FROM SOUTH TO NORTH BETWEEN 06-09Z MON; HOWEVER
WIDESPREAD IFR CEILINGS/VISBYS DEVELOP AS SITES CHANGEOVER TO
RA/BR. IFR TO LIFR CONTINUES IN RA/BR REST OF THE DAY MONDAY,
WITH STRONG CONFIDENCE IN NOT MUCH IF ANY IMPROVEMENT UNTIL THE
COLD FRONT MOVES IN FROM THE WEST BETWEEN 22Z MON-00Z TUE.
SW WINDS AROUND 5-10 KT THROUGH TONIGHT, WITH LOW LEVEL WIND
SHEAR AFTER 05Z AS SW LOW-LEVEL JET INCREASES TO AROUND 45 KT.
WINDS MON BECOME S AROUND 10 KT WITH GUSTS TO 20 KT UNTIL
FRONTAL PASSAGE AFTER 22Z, WHICH BRINGS A WINDSHIFT TO WSW/W.
MONDAY NIGHT: HIGH CONFIDENCE.
VFR, THOUGH BORDERLINE VFR/MVFR CEILINGS IN/AROUND HIGH TERRAIN.
WNW WINDS INCREASE SIGNIFICANTLY TO AROUND 15-25 KT WITH GUSTS
35-50 KT, HIGHEST GUSTS IN HIGH TERRAIN.
KBOS TERMINAL...MODERATE CONFIDENCE. VFR THROUGH 03Z MONDAY.
FZRA DEVELOPS W/MVFR CIGS/VISBYS AROUND 03Z MON. CHANGEOVER TO
RA AROUND 07Z WITH MIST AS WINDS TURN LIGHT SE, TO GO ALONG
WITH CIGS/VIS LOWERING TO IFR WITH LOW LEVEL WIND SHEAR. THESE
CONDITIONS STAY GENERALLY STEADY, UNTIL FRONTAL PASSAGE LATE IN
THE DAY BRINGS IMPROVEMENT TO VFR.
KBDL TERMINAL...MODERATE CONFIDENCE. VFR THROUGH 02Z MONDAY.
FZRA DEVELOPS W/MVFR CIGS/VISBYS AROUND 02Z MON. CHANGEOVER TO
RA WITH MIST AROUND 07Z, TO GO ALONG WITH CIGS/VIS LOWERING TO
IFR WITH LOW LEVEL WIND SHEAR. THESE CONDITIONS STAY GENERALLY
STEADY, UNTIL FRONTAL PASSAGE AROUND 20-22Z WITH IMPROVEMENT TO
VFR THEREAFTER.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. STRONG WINDS
WITH GUSTS UP TO 45 KT.
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT.
WEDNESDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
WEDNESDAY NIGHT THROUGH NEW YEARS DAY: VFR. BREEZY. SLIGHT
CHANCE SN.
THURSDAY NIGHT: VFR. SLIGHT CHANCE SN.
FRIDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH MONDAY NIGHT: HIGH CONFIDENCE.
GALE WARNINGS IN EFFECT FOR ALL WATERS WITH STRONGEST WINDS MON
NIGHT.
INCREASING S-SW WIND LATE TONIGHT INTO MONDAY WITH GUSTS 25-30 KT,
THEN WIND SHIFT TO W BEHIND THE COLD FRONT LATE MON-MON EVENING WITH
35-45 KT GUSTS DEVELOPING. VSBYS LOWERING TONIGHT INTO MON IN AREAS
OF RAIN AND FOG, IMPROVING MON NIGHT.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH SEAS UP
TO 15 FT. SLIGHT CHANCE OF SNOW.
TUESDAY NIGHT: STRONG WINDS WITH GUSTS UP TO 40 KT. ROUGH SEAS
UP TO 14 FT. FREEZING SPRAY.
WEDNESDAY: STRONG WINDS WITH GUSTS UP TO 30 KT. AREAS OF ROUGH
SEAS. SLIGHT CHANCE OF RAIN, SLIGHT CHANCE OF SNOW.
WEDNESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. CHANCE OF SNOW,
SLIGHT CHANCE OF RAIN.
NEW YEARS DAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. CHANCE
OF SNOW.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. CHANCE OF SNOW.
FRIDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
SLIGHT CHANCE OF SNOW.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR MAZ002>016-
026.
WINTER WEATHER ADVISORY UNTIL 1 AM EST MONDAY FOR MAZ017-018.
RI...WINTER WEATHER ADVISORY UNTIL 6 AM EST MONDAY FOR RIZ001-003.
WINTER WEATHER ADVISORY UNTIL 1 AM EST MONDAY FOR RIZ002-004-
006.
MARINE...GALE WARNING FROM 7 PM MONDAY TO 7 PM EST TUESDAY FOR ANZ230-
236.
GALE WARNING FROM 7 PM MONDAY TO 7 AM EST WEDNESDAY FOR ANZ231-
250-251-254.
GALE WARNING FROM 4 PM MONDAY TO 7 AM EST WEDNESDAY FOR
ANZ232>235-237.
GALE WARNING FROM 1 PM MONDAY TO 7 AM EST WEDNESDAY FOR ANZ255-
256.
DISCUSSION...KJC/MENSCH
AVIATION...MCMINN
MARINE...KJC
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