438
FXUS61 KBOX 191104
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
604 AM EST MON JAN 19 2026
WHAT HAS CHANGED
LINGERING SNOW SHOWERS DEPART FROM WEST TO EAST BETWEEN 8 AM AND
11 AM THIS MORNING WITH AN ADDITIONAL INCH OR TWO OF SNOW POSSIBLE
SOME LOCATIONS. OTHERWISE...NO SIGNIFICANT CHANGES TO THE FORECAST.
WE ARE WATCHING THE POTENTIAL FOR AN ARCTIC OUTBREAK FOR THE UPCOMING
WEEKEND AND ALSO THE TRACK OF A STORM SYSTEM TO OUR SOUTH.
KEY MESSAGES
- PERIOD OF LINGERING LIGHT SNOW ENDS FROM WEST TO EAST BETWEEN
8 AND 11 AM. ARCTIC FRONT CROSSES THE REGION TONIGHT.
- DRY BUT VERY COLD TUE & TUE NIGHT. HIGHS TUE IN THE UPPER TEENS
TO THE MIDDLE 20S WITH LOWS TUE NIGHT MAINLY 0 TO 10 ABOVE
- TEMPS MODERATE WED AND PARTICULARLY THU WHEN HIGHS MAY BREAK 40
IN SPOTS...DRY OUTSIDE A FEW BRIEF RAIN/SNOW SHOWERS POSSIBLE
- LONG RANGE MODEL GUIDANCE INDICATES AN ARCTIC OUTBREAK WITH
POTENTIALLY NEAR RECORD COLD & DANGEROUSLY COLD WIND CHILLS
FOR THE WEEKEND. MEANWHILE...MUCH OF THE AI VERSIONS OF THE
MODEL GUIDANCE ARE NOT QUITE AS COLD BUT HAVE A POTENTIAL
WINTER STORM WITH A LOW PRESSURE SYSTEM MUCH CLOSER TO THE COAST.
DISCUSSION
KEY MESSAGE 1...PERIOD OF LINGERING LIGHT SNOW ENDS FROM WEST
TO EAST BETWEEN 8 AND 11 AM. ARCTIC FRONT CROSSES THE REGION
TONIGHT.
ONE MORE SHOT OF SNOW WORKS ACROSS THE REGION THIS
MORNING. PRIMARY FORCING FOR SNOW SHOWER ACTIVITY WILL BE LOW
LEVEL CONVERGENCE WITH LOW LEVEL ENE FLOW NEAR THE COAST AND
BROAD WESTERLY FLOW FURTHER INLAND. THIS CONVERGENCE HELPS TO
WRING OUT LINGERING LOW LEVEL MOISTURE. WILL ALSO SEE SOME LOW
LEVEL INSTABILITY AS THE MID LEVELS COOL FROM COLD ADVECTION.
MODEL SOUNDINGS EVEN HAVE NON- ZERO LEVELS OF CAPE SO SNOW
SHOWERS THAT FORM MAY BRING BRIEF PULSES OF MODERATE SNOW.
SOME LOCATIONS MAY SEE AN ADDITIONAL INCH OR TWO OF SNOW.
THE LAST OF THE SNOW SHOWERS SHOULD EXIT THE REGION FROM WEST
TO EAST BETWEEN 8 AND 11 AM.
OTHERWISE...PARTIAL SUNSHINE EMERGES THIS AFTERNOON AND IT WILL
BECOME A BIT BREEZY. HIGH TEMPERATURES WILL BE IN THE LOWER TO
MIDDLE 30S.
A STRONG ARCTIC COLD FRONT CROSSES THE REGION TONIGHT. GUSTY
WEST WINDS WILL SEND OVERNIGHT LOW TEMPS DOWN INTO THE TEENS.
WIND CHILLS BY DAYBREAK WILL DROP BETWEEN 5 BELOW AND 10 ABOVE.
OUTSIDE A BRIEF FLURRY/SPOT SNOW SHOWER ACROSS THE
INTERIOR...DRY BUT VERY COLD WEATHER IS ON TAP.
KEY MESSAGE 2...DRY BUT VERY COLD TUE & TUE NIGHT. HIGHS TUE
IN THE UPPER TEENS TO THE MIDDLE 20S WITH LOWS TUE NIGHT
MAINLY 0 TO 10 ABOVE.
A RIDGE OF HIGH PRESSURE BUILDS TO OUR SOUTH TUE INTO TUE NIGHT. THIS
WILL RESULT IN DRY BUT VERY COLD WEATHER. STRONG COLD ADVECTION WITH 850T
NEAR -20C WILL HOLD HIGH TEMPS TUE IN THE UPPER TEENS TO THE MIDDLE 20S.
WESTERLY WIND GUSTS OF 20 TO 30 MPH ON TUE WILL PUT WIND CHILL VALUES
BETWEEN 5 BELOW AND 10 ABOVE TUE MORNING. WINDS WILL GRADUALLY DIMINISH
TUE NIGHT SETTING THE STAGE FOR A VERY GOOD NIGHT OF RADIATIONAL COOLING.
IT MAY TAKE UNTIL THE LATTER PART OF TUE NIGHT FOR WINDS TO DECOUPLE IN
THE TYPICAL SPOTS...BUT GIVEN THE FRESH SNOWPACK AND THE VERY COLD AIRMASS
OVERHEAD TEMPS WILL LIKELY DROP LOWER THAN GUIDANCE. THINKING OVERNIGHT
LOWS WILL BE IN THE 0 TO 10 ABOVE RANGE WITH SOME BELOW ZERO READINGS
IN THE TYPICAL COLDEST OUTLYING LOCATIONS. THE URBAN HEAT ISLAND OF BOSTON
WILL PROBABLY ONLY DROP INTO THE MIDDLE TEENS AS TEMPS BEGIN TO WARM
ALOFT.
KEY MESSAGE 3...TEMPS MODERATE WED AND PARTICULARLY THU WHEN HIGHS SHOULD
BREAK 40 IN SPOTS...DRY OUTSIDE A FEW BRIEF RAIN/SNOW SHOWERS POSSIBLE.
MUCH COLDER TEMPERATURES WORKS BACK INTO THE REGION BY FRI.
HIGH PRESSURE TO OUR SOUTH EARLY WED MOVES EAST AND AWAY FROM THE REGION.
AT THE SAME TIME...LOW PRESSURE WILL BE TRACKING WELL TO OUR NORTH ACROSS
QUEBEC WED NIGHT INTO THU. THE RESULT WILL BE A SOUTHWEST FLOW OF
SIGNIFICANTLY MILDER TEMPERATURES. WE SHOULD SEE HIGH TEMPS WED MODERATE
INTO THE UPPER 20S TO THE MIDDLE 30S WHICH IS STILL BELOW NORMAL
FOR THIS TIME OF YEAR.
AS A COLD FRONT APPROACHES FROM THE WEST WED NIGHT INTO THU...A MODEST SOUTHWEST
LLJ OF 45 TO 55 KNOTS WILL DEVELOP. THIS WILL RESULT IN SLOWLY RISING TEMPS
WED NIGHT ESPECIALLY ALONG THE COASTAL PLAIN WHERE THEY SHOULD BE ABOVE FREEZING
BY DAYBREAK THU. IN FACT...HIGH TEMPS ON THU MAY BREAK 40 IN SPOTS WITH GUSTY
SOUTHWEST WINDS. THE WARM AIR ADVECTION PATTERN MAY RESULT IN A FEW BRIEF SNOW
SHOWERS AND PERHAPS EVEN RAIN SHOWERS NEAR THE COAST WED NIGHT INTO EARLY THU...
BUT DURATION OF ANY ACTIVITY WILL BE SHORT WITH RATHER LIGHT AMOUNTS. MUCH
COLDER AIR BEGINS TO RETURN TO THE REGION ON FRI BEHIND A COLD FRONTAL PASSAGE.
KEY MESSAGE 4...LONG RANGE MODEL GUIDANCE INDICATES AN ARCTIC OUTBREAK WITH
POTENTIALLY NEAR RECORD COLD & DANGEROUSLY COLD WIND CHILLS FOR THE WEEKEND.
MEANWHILE...MUCH OF THE AI VERSIONS OF THE MODEL GUIDANCE ARE NOT QUITE AS
COLD BUT HAVE A POTENTIAL WINTER STORM WITH A LOW PRESSURE SYSTEM MUCH
CLOSER TO THE COAST.
THE UPCOMING WEEKEND IS AN ETERNITY IN THE MODEL GUIDANCE WORLD...BUT IT
LOOKS QUITE INTERESTING. MUCH OF THE LONG RANGE GUIDANCE INDICATES A PIECE OF
THE POLAR VORTEX BREAKING OFF AND SENDING US A SHOT OF ARCTIC AIR THAT WOULD
POTENTIALLY CHALLENGE RECORDS AND RESULT IN DANGEROUSLY COLD WIND CHILLS.
MEANWHILE...THE AI MODEL SUITE TENDS TO NOT PENETRATE THIS ARCTIC COLD AS FAR
SOUTH RESULTING IN LOW PRESSURE TRACKING MUCH CLOSER TO THE COAST. THIS WOULD
LIMIT THE DEEP SOUTHWARD PENETRATION OF THE BITTER COLD...BUT ALSO ALLOW LOW
PRESSURE TO TRACK CLOSER TO THE COAST AND BRING US A POTENTIAL WINTER STORM.
IT IS WAY TOO EARLY TO SAY MUCH MORE AT THIS TIME. THE AI GUIDANCE TENDS TO FAVOR
A POTENTIAL COASTAL STORM WITH THE REGULAR MODEL GUIDANCE FAVORING MORE BITTERLY
COLD. HOWEVER...IT IS NOT ONE TO ONE AS THE INDIVIDUAL MEMBERS OF THE REGULAR
AND AI GUIDANCE DO SHOW BOTH POSSIBILITIES. THE AI GUIDANCE HAS SHOWN SKILL
IN RECENT EVENTS INCLUDING THE CURRENT SNOW EVENT THAT WILL BE WRAPPING UP SHORTLY.
THAT BEING SAID...EVEN ITS INDIVIDUAL ENSEMBLES ARE SHOWING LARGE SPREAD IN
POSSIBLE OUTCOMES. AND GIVEN THIS IS 6-7 DAYS IN THE FUTURE...WILL BE AT LEAST
A FEW MORE DAYS UNTIL WE HAVE A BETTER IDEA.
AVIATION /12Z MONDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE...
TODAY...MODERATE CONFIDENCE.
LINGERING LIGHT SNOW SHOWERS WERE RESULTING IN MAINLY MVFR
CONDITIONS VERY EARLY THIS MORNING WITH LOCALIZED IFR
CONDITIONS. THESE LINGERING LIGHT SNOW SHOWERS SHOULD EXIT THE
REGION BETWEEN 13Z AND 16Z FROM WEST TO EAST. OTHERWISE...VFR
CONDITIONS TAKE OVER THIS AFTERNOON BUT GUSTY SW WINDS OF 20 TO
30 KNOTS DEVELOP.
TONIGHT...HIGH CONFIDENCE.
VFR. WSW WINDS GUST BETWEEN 20 AND 30 KNOTS WITH EVEN A FEW
BRIEF GUSTS TO 35 KNOTS. THEY MAY TEMPORARILY DIMINISH A BIT
AFTER 6Z BEFORE PICKING UP TUESDAY MORNING.
KBOS TERMINAL...LINGERING LIGHT SNOW SHOWERS SHOULD DEPART
AFTER 15Z/16Z.
KBDL TERMINAL...LINGERING LIGHT SNOW SHOWERS SHOULD DEPART
AFTER 13Z/14Z.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY THROUGH WEDNESDAY: VFR. BREEZY.
WEDNESDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
SLIGHT CHANCE SHSN.
THURSDAY: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE SHSN.
THURSDAY NIGHT THROUGH FRIDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY AND TONIGHT...
DEPARTING LOW PRESSURE BRINGS A PERIOD OF INCREASING WEST WINDS
WITH SEAS BUILDING 5-8 FEET TODAY, WITH UP TO 10 FEET ACROSS THE
SOUTHERN OUTER WATERS. WESTERLY WINDS INCREASE DURING THE LATE
AFTERNOON INTO EARLY EVENING. A STRONG ARCTIC COLD FRONT CROSSES
THE WATERS OVERNIGHT INTO EARLY TUESDAY, BRINGING WESTERLY
GALES. INCREASING COLD AIR ADVECTION MAY ALSO RESULT IN FREEZING
SPRAY ACROSS ALL WATERS LATE TONIGHT INTO TUESDAY MORNING. THE
THEME TUESDAY WILL BE GRADUALLY DECREASING SEAS AS BROAD HIGH
PRESSURE APPROACHES FROM THE SOUTHWEST. SEAS WILL LIKELY REMAIN
BETWEEN 5 AND 7 FEET THROUGH MUCH OF THE DAY.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS.
TUESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. SEAS LOCALLY APPROACHING 5 FT.
WEDNESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. LOCAL ROUGH SEAS. SLIGHT CHANCE OF RAIN
SHOWERS.
THURSDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
LOCAL GUSTS UP TO 30 KT. LOCAL ROUGH SEAS. SLIGHT CHANCE OF
RAIN SHOWERS.
THURSDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. SLIGHT CHANCE OF
RAIN SHOWERS.
FRIDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. LOCAL ROUGH SEAS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
CTZ002>004.
MA...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MAZ002>023-026.
RI...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
RIZ001>007.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 7 PM EST
TUESDAY FOR ANZ230-236.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 9 AM EST TUESDAY FOR
ANZ231>235-237-250-251-254>256.
DISCUSSION...FT/FRANK
AVIATION...FT/FRANK
MARINE...FT/FRANK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page