850
FXUS61 KBOX 031051
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
551 AM EST TUE MAR 3 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES MADE TO THE WINTRY MIX TODAY AND
TONIGHT...BUT SOME BLACK ICE IS A CONCERN AFTER THIS ACTIVITY
DEPARTS FOR THE EARLY WEDNESDAY MORNING COMMUTE.
KEY MESSAGES
- MAINLY SNOW ARRIVES FROM SOUTHWEST TO NORTHEAST BETWEEN 11 AM
AND 3 PM THEN CHANGES TO RAIN NEAR THE COAST BUT WITH POCKETS
OF LIGHT FREEZING RAIN ACROSS THE INTERIOR INTO TONIGHT. SNOW
ACCUMULATIONS A COATING TO 2" WITH ICE ACCRETION UP 0.10".
- AREAS OF BLACK ICE POSSIBLE EARLY WED MORNING. OTHERWISE...DRY
& MILDER WED WITH HIGHS IN THE UPPER 40S TO THE MIDDLE 50S.
THE ONE CAVEAT IS IF FOG HANGS ON LATER THAN EXPECTED...HIGHS
WILL BE COOLER THAN CURRENTLY FORECAST.
- A PERIOD OF WINTRY PRECIP REMAINS POSSIBLE THU NIGHT INTO EARLY
FRI.
- PATTERN CHANGE TOWARDS MILDER WEATHER THIS WEEKEND AND
POTENTIALLY WARMER NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...MAINLY SNOW ARRIVES FROM SOUTHWEST TO NORTHEAST
BETWEEN 11 AM AND 3 PM THEN CHANGES TO RAIN NEAR THE COAST BUT WITH
POCKETS OF LIGHT FREEZING RAIN ACROSS THE INTERIOR INTO TONIGHT.
SNOW ACCUMULATION'S A COATING TO 2" WITH ICE ACCRETION UP
0.10".
A LARGE 1040 MB HIGH PRESSURE SYSTEM WILL CONTINUE TO SHIFT FURTHER
EAST AND WAY FROM THE REGION TODAY. AT THE SAME TIME...SHORTWAVE
ENERGY WILL APPROACH FROM THE WEST SO BRIEF MORNING SUNSHINE WILL
QUICKLY FADE BY LOWERING AND THICKENING CLOUDS. THIS SHORTWAVE WILL
ALSO INDUCE A MODEST SOUTHWEST LLJ ON THE ORDER OF 35 TO 45 KNOTS.
THIS WILL INCREASE THE FORCING FOR ASCENT AND PRECIPITATION SHOULD
ARRIVE FROM SOUTHWEST TO NORTHEAST...ROUGHLY BETWEEN 11 AM AND 3 PM.
THERMAL PROFILES INDICATE ANTECEDENT AIRMASS SHOULD INITIALLY BE
COLD ENOUGH FOR MAINLY SNOW EXCEPT PERHAPS THE IMMEDIATE SOUTH
COAST, CAPE AND ISLANDS. GIVEN LIGHT TO MODERATE INTENSITY DURING
THE DAYLIGHT HOURS...THE EARLY MARCH SUN ANGLE WILL PROBABLY KEEP
ROADS WET/SLUSHY OUTSIDE THE HIGHEST TERRAIN. SNOW OF A
COATING TO 2 INCHES OF SNOW WITH HIGHER AMOUNTS EXPECTED NORTH
OF I-90.
HIGH PRESSURE SLIDING DIRECTLY EAST OF OUR LATITUDE...MID LEVEL
WARMTH WILL QUICKLY OVERSPREAD THE REGION. THIS WILL ALLOW SNOW
TO CHANGE TO RAIN ALONG THE COASTAL PLAIN FROM SOUTH TO NORTH
WITH PERHAPS A BRIEF PERIOD OF SLEET DURING THE
TRANSITION...ROUGHLY IN THE 4 TO 8 PM TIME FRAME. PERIODS OF
RAIN & DRIZZLE WILL CONTINUE TONIGHT ACROSS THE COASTAL PLAIN
ALONG WITH AREAS OF FOG. THE BIGGER CONCERN WILL BE NORTHWEST OF
I-95 AND INTO PARTS OF THE INTERIOR WHERE TEMPS WILL REMAIN AT
OR BELOW FREEZING INTO TUE NIGHT. THIS WILL RESULT IN THE SNOW
TRANSITIONING TO POCKETS OF LIGHT FREEZING RAIN. ICE ACCRETION
OF UP TO ONE TENTH OF AN INCH ARE POSSIBLE AND UNTREATED
ROADS/WALKWAYS MAY BECOME ICY TONIGHT.
DEPARTING SHORTWAVE SHOULD BRING AN END TO THE PRECIPITATION TOWARD
DAYBREAK. LIGHT WINDS AND PERHAPS SOME CLEARING MAY RESULT IN AREAS
OF FOG AND BLACK ICE FOR THE WED MORNING COMMUTE.
KEY MESSAGE 2...AREAS OF BLACK ICE POSSIBLE EARLY WED MORNING.
OTHERWISE...DRY & MILDER WED WITH HIGHS IN THE UPPER 40S TO THE
MIDDLE 50S. THE ONE CAVEAT IS IF FOG HANGS ON LATER THAN
EXPECTED...HIGHS WILL BE COOLER THAN CURRENTLY FORECAST.
GIVE THE LEFT OVER LOW LEVEL MOISTURE, LIGHT WINDS, AND NEAR OR SUB-
FREEZING TEMPERATURES WILL HAVE TO WATCH FOR AREAS OF FOG AND BLACK
ICE EARLY WED MORNING. OTHERWISE...SUBSIDENCE BEHIND TONIGHT/S
SHORTWAVE SHOULD ALLOW PLENTY OF SUNSHINE AND 925T REMAIN
BETWEEN +5C AND +6C. THIS SHOULD YIELD A MILD WEDNESDAY
AFTERNOON WITH HIGHS IN THE UPPER 40S TO THE MIDDLE 50S. MOST
LOCATIONS AWAY FROM THE IMMEDIATE COAST/SEA BREEZE POTENTIAL
SHOULD BREAK 50! THE ONE CAVEAT IS THE POTENTIAL FOR LOW
CLOUDS/FOG PATCHES TO HANG ON LATER THAN EXPECTED. GIVEN VERY
WEAK SURFACE FLOW THIS CAN NOT BE RULED OUT...SO IF THIS WERE TO
OCCUR HIGHS WOULD BE LOWER THAN CURRENTLY FORECAST.
KEY MESSAGE 3...A PERIOD OF WINTRY PRECIP REMAINS POSSIBLE THU NIGHT
INTO EARLY FRI.
MID TO LATE WEEK THE SYNOPTIC PATTERN REMAINS FLAT AND ZONAL WITH
THE FIRST SHORTWAVE MOVING THROUGH LATE THURSDAY INTO FRIDAY. THIS,
WHILE A 1040MB HIGH PRESSURE SITS OVER SOUTHEAST QC SETTING UP A
POTENTIAL COLD AIR DAMMING SITUATION. WHILE THE MID LEVEL
DISTURBANCE MOVES THROUGH A MOIST ENVIRONMENT ON THURSDAY BRINGING
RAIN TO MUCH OF THE AREA, STUBBORN NE SURFACE FLOW INTO THE HIGH
TERRAIN WILL LIKELY KEEP TEMPS BELOW FREEZING LEADING TO THE
POSSIBILITY OF FREEZING RAIN. THE RISK FOR NOW LOOKS TO BE LIMITED
TO THE HIGH TERRAIN OF INTERIOR MA AND CT WHERE ENSEMBLE GUIDANCE
PAINTS A 20-35% CHANCE OF AT LEAST A TENTH OF AN INCH OF ICE
OVERNIGHT.
KEY MESSAGE 4...PATTERN CHANGE TOWARDS MILDER WEATHER THIS WEEKEND
AND POTENTIALLY WARMER NEXT WEEK.
THERE CONTINUES TO BE GOOD MODEL AGREEMENT IN A PATTERN SHIFT
LOOKING INTO THE EXTENDED FORECAST WITH AN ATLANTIC RIDGE LEADING TO
WARMER SW FLOW DIRECTED INTO SOUTHERN NEW ENGLAND. HOWEVER, THERE
REMAINS A GOOD DEGREE OF UNCERTAINTY AS TO THE MAGNITUDE AND
DURATION OF THE WARM UP GIVEN THE QUICK, TRANSIENT PATTERN; GEFS
PLUMES SHOW A BIG INCREASE IN SPREAD IN 2M-TEMP GUIDANCE BEYOND
FRIDAY HIGHLIGHTING THAT LOWER CONFIDENCE. OVERALL, THOUGH, HIGH
TEMPERATURES IN THE LOW 50S ARE POSSIBLE THIS WEEKEND WITH PERHAPS
EVEN SOME LOW 60S AS WE GO INTO THE NEW WEEK. THIS WITH A HIGH MARCH
SUN ANGLE AND ELEVATED DEWPOINTS WILL HELP TO MELT AWAY OUR EXISTING
SNOWPACK.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE...
TODAY AND TONIGHT...HIGH CONFIDENCE IN TRENDS WITH MODERATE
CONFIDENCE IN TIMING.
MVFR-IFR CONDITIONS IN MAINLY SNOW OVERSPREAD THE REGION FROM
SOUTHWEST TO NORTHEAST IN THE 15Z TO 20Z TIME FRAME. PTYPE
INITIALLY MAINLY SNOW BUT A QUICK CHANGE TO RAIN FROM SOUTH TO
NORTH OCCURS IN THE 21Z TO 01Z TIMEFRAME ALONG THE COASTAL
PLAIN WITH PERHAPS A BRIEF PERIOD OF SLEET DURING THE
TRANSITION. HOWEVER...ACROSS PORTIONS OF THE INTERIOR TEMPS NEAR
OR JUST BELOW FREEZING WILL RESULT IN SNOW/SLEET TRANSITIONING
TO POCKETS OF LIGHT FREEZING RAIN BY EARLY EVENING. IFR TO LIFR
CONDITIONS EXPECTED TONIGHT WITH PERIODS OF RAIN ALONG THE
COASTAL PLAIN AND POCKETS OF LIGHT FREEZING RAIN ACROSS PARTS
OF THE INTERIOR. WINDS GENERALLY LESS THAN 10 KNOTS TODAY AND
TONIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SNOW ARRIVES NEAR OF
JUST AFTER 19Z AND FLIPS TO RAIN BY 23Z WITH PERHAPS A BRIEF
PERIOD OF SLEET DURING THE TRANSITION. LITTLE IMPACT ON RUNWAYS
EXPECTED.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. SNOW ARRIVES AROUND
16Z/17Z AND FLIPS TO LIGHT RAIN/FREEZING RAIN BY 22Z/23Z WITH
PERHAPS A PERIOD OF SLEET DURING THE TRANSITION. TEMPS THIS
EVENING WILL BE NEAR FREEZING...SO IMPACTS MAY BE SOMEWHAT
LIMITED ON RUNWAYS BUT SOME ICING CAN NOT BE RULED OUT.
WEDNESDAY...MODERATE CONFIDENCE.
MVFR-IFR WITH EVEN LOCALIZED LIFR CONDITIONS IN LOW CLOUDS/FOG
PATCHES EARLY WED MORNING IMPROVE TO VFR BY WED AFTERNOON. IT IS
POSSIBLE FOG COULD LINGER LONGER IN LOW LYING LOCATIONS GIVEN
VERY WEAK WINDS/POOR MIXING.
OUTLOOK /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY: VFR.
WEDNESDAY NIGHT: VFR. SLIGHT CHANCE FZRA.
THURSDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE RA,
SLIGHT CHANCE FZRA.
THURSDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. BREEZY.
CHANCE RA, CHANCE FZRA.
FRIDAY: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. RA LIKELY, FZRA
LIKELY.
FRIDAY NIGHT: MAINLY VFR, WITH AREAS IFR POSSIBLE. SLIGHT
CHANCE RA, SLIGHT CHANCE FZRA.
SATURDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. SLIGHT
CHANCE RA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH WEDNESDAY...HIGH CONFIDENCE.
HIGH PRESSURE CONTINUES TO MOVE EAST OF THE WATERS TODAY. THIS WILL
RESULT IN LONG S-SW FETCH AND BUILD SEAS INTO THE 3 TO 6 FOOT RANGE
LATE TONIGHT INTO WED ACROSS OUR SOUTHERN WATERS. THEREFORE...WE
HAVE ISSUED SMALL CRAFT ADVISORIES FOR OUR SOUTHERN OUTER-
WATERS.
OUTLOOK /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. SLIGHT CHANCE OF RAIN, SLIGHT CHANCE OF
FREEZING RAIN.
THURSDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN, SLIGHT CHANCE OF FREEZING RAIN.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. RAIN LIKELY.
FRIDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. RAIN
LIKELY.
FRIDAY NIGHT THROUGH SATURDAY: WINDS LESS THAN 25 KT. AREAS OF
ROUGH SEAS. SLIGHT CHANCE OF RAIN.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST WEDNESDAY
FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST WEDNESDAY
FOR MAZ002>012-014-026.
RI...WINTER WEATHER ADVISORY FROM NOON TODAY TO 7 AM EST WEDNESDAY
FOR RIZ001.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
WEDNESDAY FOR ANZ254>256.
DISCUSSION...FRANK/BW/NOCERA
AVIATION...FRANK/BW
MARINE...FRANK/BW/NOCERA
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