276
FXUS61 KBOX 181905
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
205 PM EST SUN JAN 18 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO THE FORECAST. WINTER WEATHER ADVISORIES
REMAIN IN EFFECT TONIGHT.
KEY MESSAGES
- PLOWABLE SNOW TONIGHT WITH TOTAL ACCUMULATIONS OF 3-5" WITH
LOCALIZED 6" AMOUNTS POSSIBLE ACROSS EASTERN MA/RI. HEAVIEST
SNOW/WORST OF THE TRAVEL CONDITIONS BETWEEN 6 PM AND 2 AM.
SNOW ENDS FROM WEST TO EAST BETWEEN 3AM AND 9AM MONDAY.
- ARCTIC COLD FRONT SWEEPS ACROSS THE REGION MON NIGHT BRINGING
WELL BELOW NORMAL TEMPERATURES AND BITTERLY COLD WIND CHILLS &
TEMPS. THE PEAK OF THE COLD WEATHER WILL BE TUE INTO WED AM.
- MILDER TEMPS ARRIVE WED NIGHT-THU WITH PERHAPS A BRIEF PERIOD
OF LIGHT SNOW SHOWERS OR EVEN LIGHT RAIN SHOWERS NEAR THE
COAST.
- ANOTHER SHOT OF VERY COLD AIR WORKS INTO THE REGION BEHIND
A COLD FRONT THU NIGHT INTO FRI.
DISCUSSION
KEY MESSAGE 1...PLOWABLE SNOW TODAY-TONIGHT WITH TOTAL ACCUMULATIONS
OF 2-6" WITH LOCALIZED 7" AMOUNTS POSSIBLE ACROSS EASTERN
MA/RI. HEAVIEST SNOW/WORST OF THE TRAVEL CONDITIONS BETWEEN 5 PM
AND 1 AM...BUT SNOW SHOWERS MAY LINGER FOR THE MON AM COMMUTE.
AN ELONGATED SHORTWAVE TROUGH STRETCHING FROM THE NORTHERN GREAT
LAKES DOWN INTO THE GULF COAST WILL SPIN UP A COASTAL LOW OFFSHORE,
PASSING JUST SOUTHEAST OF THE BENCHMARK THIS EVENING. GUIDANCE HELD
STEADY, WITH TOTAL QPF ACROSS THE REGION RANGING FROM 1/2 TO 3/4
INCHES, SOUTH AND EAST OF THE I-95 CORRIDOR, INCLUDING THE CAPE AND
ISLANDS. QPF TICKED UP A BIT NORTH AND WEST OF THE I-95 CORRIDOR ALL
THE WAY TO THE NORTHERN BERKSHIRES WITH 1/4 TO 1/2 INCH OF QPF. HOW
THIS TRANSLATES INTO SNOWFALL ACCUMULATION WILL DEPEND HEAVILY ON
TEMPERATURES AND WHERE MID-LEVEL FORCING SETS UP. TEMPERATURES
DURING THIS EVENT WILL BE MARGINAL, WITH INLAND AREAS STAYING NEAR
FREEZING AND THE CAPE AND ISLANDS STAYING AT OR ABOVE FREEZING. WITH
THE BEST MID-LEVEL FORCING NEAR THE CAPE AND ISLANDS, WE WILL LIKELY
SEE SNOW AT TEMPERATURES UP TO 36F AS SNOW RATES WILL BE ABLE TO
OVERCOME THE WARM TEMPS. THE PRIMARY SOURCE OF UNCERTAINTY IS THE
TEMPERATURE AT WHICH SNOW WILL ACCUMULATE ON PAVED SURFACES. BECAUSE
OF THE WARM TEMPS, WE CONTINUED TO TREND TOTAL ACCUMULATIONS DOWN TO
0.5-1.5 INCHES FOR THE OUTER CAPE AND THE ISLANDS; HOWEVER, IF TEMPS
COOL BELOW FREEZING, SNOW ACCUMULATIONS COULD EXCEED 2-4.
THE HIGHEST CONFIDENCE IN SNOW ACCUMULATIONS REMAINS ALONG THE I-95
CORRIDOR IN EASTERN MA AND INTO RI, WHERE GOOD MID-LEVEL FORCING AND
TEMPERATURES NEAR OR BELOW FREEZING WILL OVERLAP. SNOW
ACCUMULATIONS IN THIS AREA WILL RANGE FROM 3-5 INCHES, WITH
LOCALIZED SPOTS UP TO 6 INCHES POSSIBLE. TO THE NORTH AND WEST OF
THE I-95 CORRIDOR, MID-LEVEL FORCING BEGINS TO DROP OFF; HOWEVER,
COOLER TEMPERATURES WILL ALLOW SNOW RATIOS TO BE HIGHER, RANGING
BETWEEN 12-1 TO 16-1. SNOW TOTALS NORTH AND WEST OF THE I-95
CORRIDOR, INCLUDING ALL OF CT, WILL RANGE FROM 2-4 INCHES, WITH
LOCALIZED AREAS OF 5 INCHES.
AFTER THE LULL IN SNOWFALL THIS AFTERNOON, STEADY LIGHT SNOW WILL
BEGIN TO OVERSPREAD THE REGION ONCE AGAIN THROUGH 6 PM. SNOW RATES
WILL START TO TICK UP AFTER 6 PM, INCREASING TO 0.5 TO 1.5 INCHES
PER HOUR. SNOW BECOMES LIGHT AGAIN AFTER 2-4 AM AND TAPERS OFF FROM
WEST TO EAST THROUGH 6-9 AM THIS MORNING. SNOW SHOWERS MAY LINGER
OVER EASTERN MA UNTIL NOON, BUT ADDITIONAL ACCUMULATIONS WILL BE
LIGHT. THE MOST DIFFICULT TRAVEL PERIOD WILL BE BETWEEN 6 PM AND 2
AM TONIGHT. HOWEVER, WITH LINGERING SNOW SHOWERS INTO MONDAY
MORNING, THE AM COMMUTE WILL LIKELY BE IMPACTED.
LOW TEMPERATURES ON MONDAY MORNING ARE EXPECTED TO DROP INTO THE LOW
TO MID-20S ACROSS THE REGION, WHICH COULD CAUSE ANY STANDING WATER
FROM MELTING SNOW TO REFREEZE, ESPECIALLY ON UNTREATED SURFACES.
HIGH TEMPERATURES MONDAY AFTERNOON REBOUND INTO THE LOW TO MID 30S,
ALLOWING SOME MELTING. WINDS BECOME GUSTY OUT OF THE WSW MONDAY
AFTERNOON AT 15-20MPH, MAKING IT FEEL LIKE THE LOW TO MID 20S.
KEY MESSAGE 2...ARCTIC COLD FRONT SWEEPS ACROSS THE REGION MONDAY
NIGHT BRINGING WELL BELOW NORMAL TEMPERATURES AND BITTERLY COLD
WIND CHILLS & TEMPS. THE PEAK OF THE COLD WEATHER WILL BE TUE
INTO EARLY WED MORNING.
THE MODELS ARE STILL IN VERY GOOD AGREEMENT IN AN ARCTIC COLD FRONT
CROSSING THE REGION MON NIGHT. THIS WILL BRING A SHOT OF ARCTIC AIR
AND WELL BELOW NORMAL TEMPERATURES TO THE REGION. 850T WILL DROP TO
BETWEEN -18C AND -20C WITH THE COLD PEAKING TUE INTO EARLY WED.
GUSTY WEST WINDS WILL RESULT IN WIND CHILLS BELOW ZERO TO THE SINGLE
DIGITS. HIGH TEMPS TUE WILL ONLY BE IN THE UPPER TEENS TO THE
MIDDLE 20S WITH LOW TEMPS TUE NIGHT MAINLY IN THE SINGLE DIGITS
TO THE LOWER TEENS. THIS SHOT OF ARCTIC AIR WILL BE SHORT-LIVED
AS HIGH PRESSURE SHIFTS TO OUR EAST BY WED. WE SHOULD SEE HIGH
TEMPS RECOVER INTO THE MIDDLE 20S AND LOWER 30S BY WED
AFTERNOON...WHICH IS STILL BELOW NORMAL.
KEY MESSAGE 3...MILDER TEMPS ARRIVE WED NIGHT-THU WITH PERHAPS
A BRIEF PERIOD OF LIGHT SNOW SHOWERS OR EVEN LIGHT RAIN SHOWERS
NEAR THE COAST.
LOW PRESSURE TRACKING ACROSS QUEBEC WILL RESULT IN MUCH MILDER
AIR WORKING BACK INTO THE REGION ON SOUTHWEST FLOW. WE MAY SEE
A PERIOD OF LIGHT SNOW SHOWERS IN THE WARM AIR ADVECTION PATTERN
AND PERHAPS EVEN LIGHT RAIN SHOWERS NEAR THE COAST AS THE
BOUNDARY LAYER WARMS. REGARDLESS...THESE RAIN/SNOW SHOWERS WILL
LIKELY BE SHORT-LIVED AND NOT EXPECTING A SIGNIFICANT
PRECIPITATION EVENT.
KEY MESSAGE 4...ANOTHER SHOT OF VERY COLD AIR WORKS INTO THE
REGION BEHIND A COLD FRONT THU NIGHT INTO FRI.
ANOTHER SHOT OF VERY COLD AIR WORKS INTO SOUTHERN NEW ENGLAND
BEHIND A STRONG COLD FRONT THU NIGHT INTO FRI. HIGHS MAY BE HELD
IN THE UPPER 20S AND LOWER 30S ON FRI BUT WITH MAINLY DRY
WEATHER.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...
MODERATE CONFIDENCE.
OVERALL FORECAST TRENDS HAVE NOT CHANGED SUBSTANTIALLY.
CURRENTLY MUCH OF THE AREA IS IN A BIT OF A LULL BETWEEN THE
INITIAL ROUND OF PRECIPITATION, AND THE NEXT, MORE SUBSTANTIAL
BATCH. PREDOMINANTLY IFR CONDITIONS IN MOST AREAS, WITH AREAS
OF 2-4SM IN BR AND THEN -SN, ESPECIALLY ACROSS SOUTHEAST AREAS.
TEMPERATURES ARE MARGINAL FOR SOME -RA ACROSS PARTS OF THE CAPE
AND THE ISLANDS. PRECIPITATION, PRIMARILY IN THE FORM OF SNOW
(EXCEPT WITH SOME RAIN MIXED IN ACROSS THE CAPE AND ISLANDS)
WILL OVERSPREAD THE REGION BETWEEN 20-23Z. BEST ESTIMATE IS THAT
THE CORE OF THE HEAVIEST PRECIPITATION WILL BE GENERALLY FROM
00-07Z (EARLIEST IN THE WEST). MOST LOCATIONS SHOULD SEE A FEW
HOURS OF 1/2SM IN MODERATE TO BRIEFLY HEAVY SNOWFALL DURING THIS
PERIOD. STILL QUITE A BIT OF INCONSISTENCY AMONGST MODELS, SO
EXACT TIMING HAS AN ERROR BAR OF ROUGHLY 2 TO 3 HOURS. SNOW WILL
TAPER OFF FROM WEST TO EAST IN THE 10-14Z PERIOD. EXPECT
IFR/MVFR CEILINGS AND VISIBILITIES TO CONTINUE A FEW HOURS AFTER
THAT, UNTIL DRIER AIR STARTS MOVING IN. CONDITIONS WILL TREND
TOWARD VFR MONDAY AFTERNOON, WITH WEST WINDS GUSTING 20KT OR
HIGHER IN MANY AREAS, ESPECIALLY AFTER 18Z.
MONDAY NIGHT IS EXPECTED TO FEATURE VFR CONDITIONS, THOUGH WITH
STILL SOME WEST WINDS GUSTING 15-20KT OR SO.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. THOUGH THE TAF
STARTS WITH NO MENTION OF SNOW THROUGH 21Z, CAN'T RULE OUT THE
OCCASIONAL FLURRY. WINDS SHOULD TRANSITION FROM SW TO N TO NE
FROM 19 TO 21Z. SPECIFIC TIMING OF THE HEAVIEST OF THE SNOW
COULD BE OFF BY UP TO 2 HOURS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. SPECIFIC TIMING OF THE
HEAVIEST OF THE SNOW COULD BE OFF BY UP TO 2 HOURS.
OUTLOOK /MONDAY NIGHT THROUGH FRIDAY/...
TUESDAY THROUGH WEDNESDAY: VFR. BREEZY.
WEDNESDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SN.
THURSDAY: VFR. BREEZY. CHANCE RA, CHANCE SN.
THURSDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SN.
FRIDAY: VFR. BREEZY.
MARINE
TODAY AND TONIGHT...HIGH CONFIDENCE.
RESIDUAL SEAS OF 5-8 FEET ON THE SOUTHERN WATERS AND 3-6 FEET ON THE
EASTERN WATERS IS THE BASIS FOR A CONTINUED SMALL CRAFT ADVISORY ON
THE OUTER WATERS, WHICH IS IN EFFECT THROUGH SUNDAY MORNING. COASTAL
STORM PASSES OFF SHORE TODAY, BRINGING A RAIN/SNOW MIXTURE AND
POOR VISBY CONDITIONS. BRIEF LULL IN ADVISORY LEVEL CONDITIONS,
SEAS FALL BELOW 5 FEET WITH LIGHT WINDS. INCREASING WIND
SPEED/GUSTS WITH SEAS COMING UP LATE TONIGHT INTO EARLY MONDAY,
LIKELY WILL NEED TO BE HANDLED WITH A RENEWED SMALL CRAFT
ADVISORY.
OUTLOOK /MONDAY NIGHT THROUGH FRIDAY/...
TUESDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. AREAS OF ROUGH
SEAS. FREEZING SPRAY.
TUESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. LOCAL ROUGH SEAS. FREEZING SPRAY.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY NIGHT THROUGH THURSDAY: LOW RISK FOR SMALL CRAFT
ADVISORY WINDS WITH GUSTS UP TO 25 KT. AREAS OF ROUGH SEAS.
CHANCE OF RAIN.
THURSDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. CHANCE OF FREEZING
SPRAY, SLIGHT CHANCE OF RAIN, SLIGHT CHANCE OF SNOW.
FRIDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF SEAS APPROACHING 5 FT. CHANCE OF FREEZING
SPRAY.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR MAZ002>023-
026.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR RIZ001>007.
MARINE...GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
ANZ230>234-236-251.
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
ANZ235-237.
GALE WATCH FROM MONDAY MORNING THROUGH TUESDAY MORNING FOR
ANZ250-254>256.
DISCUSSION...KP
AVIATION...NASH
MARINE...DOOLEY
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