372
FXUS61 KBOX 041746
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1246 PM EST WED MAR 4 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES MADE TO THE FORECAST WITH THE GREATEST
CONCERNS BEING BLACK ICE EARLY THIS MORNING AND ANOTHER WINTRY MIX
THURSDAY NIGHT AND FRIDAY.
KEY MESSAGES
- AREAS OF BLACK ICE EARLY THIS MORNING, OTHERWISE DRY AND
MILDER THIS AFTERNOON. HIGHS WILL BE IN 40S OR 50S WITH THE
HIGHER TEMPS DEPENDENT ON HOW QUICK LOW CLOUDS/FOG DISSIPATE.
PATCHY FOG DEVELOPS LATE TONIGHT WITH LOWS MAINLY IN THE UPPER
TEENS AND 20S.
- ANOTHER ROUND OF RAIN AND FREEZING RAIN LATE THURSDAY INTO EARLY
FRIDAY. WINTRY WEATHER GENERALLY ALONG AND NORTH OF THE MASS PIKE.
- PATTERN CHANGE TOWARDS MILDER WEATHER THIS WEEKEND AND LOOKING
MORE LIKELY FOR VERY WARM TEMPS NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...AREAS OF BLACK ICE EARLY THIS MORNING, OTHERWISE DRY
AND MILDER THIS AFTERNOON. HIGHS WILL BE IN 40S OR 50S WITH THE HIGHER
TEMPS DEPENDENT ON HOW QUICK LOW CLOUDS/FOG DISSIPATE. PATCHY FOG DEVELOPS
LATE TONIGHT WITH LOWS MAINLY IN THE UPPER TEENS AND 20S.
THE WINTRY MIX SHOULD DEPART OUR REGION TOWARD DAYBREAK AS THE
SHORTWAVE MOVES OFF THE COAST. THE CONCERN WILL THEN TURN TO THE
FORMATION OF BLACK ICE AND AREAS OF FOG FOR THE EARLY MORNING
COMMUTE. RESIDUAL MOISTURE, LIGHT WINDS AND COLD GROUND WILL MAKE
FOR A VERY FAVORABLE ENVIRONMENT FOR BLACK ICE TO DEVELOP...PERHAPS
WITH SOME FREEZING FOG TOO. WE HAVE GONE AHEAD AND ISSUED A SPECIAL
WEATHER STATEMENT TO HIGHLIGHT THIS CONCERN.
OTHERWISE...HIGH PRESSURE BUILDS OVER THE REGION TODAY. THE
UNCERTAINTY REVOLVES AROUND VERY WEAK MIXING AND HOW LONG THE LOW
CLOUDS/FOG LINGER. THE GUIDANCE IS QUITE AGGRESSIVE IN SCOURING THE
LOW CLOUDS OUT QUICKLY. IF THAT HAPPENS...925T IN THE +5C/+6C RANGE
WOULD SUPPORT HIGHS INTO THE LOWER TO MIDDLE 50S. HOWEVER...THERE IS
CONCERN THAT THE LOW CLOUDS/FOG WILL BE SLOWER TO DISSIPATE ESPECIALLY
IN THOSE TYPICAL LOW-LYING VALLEY LOCATIONS ESPECIALLY THE CT RIVER VALLEY.
IF THIS OCCURS...THESE LOCATIONS WILL BE HELD IN THE 40S. THIS WILL
BE MORE OF A NOWCAST SITUATION...BUT MAY HAVE THE COOLER READINGS IN
PARTS OF THE LOWER CT RIVER VALLEY AND PERHAPS THE IMMEDIATE COAST
TOO IF SEA BREEZES DEVELOP.
WE SHOULD SEE TEMPS DROP QUICKLY AFTER SUNSET GIVEN LIGHT/CALM WINDS
AND STILL PLENTY OF SNOWPACK ACROSS THE REGION. LOW TEMPS SHOULD
MAINLY BE IN THE UPPER TEENS AND 20S TONIGHT. THIS WILL LIKELY LEAD
TO THE FORMATION OF PATCHY FOG LATE TONIGHT.
KEY MESSAGE 2...ANOTHER ROUND OF RAIN AND FREEZING RAIN LATE
THURSDAY INTO EARLY FRIDAY. WINTRY WEATHER GENERALLY ALONG AND NORTH
OF THE MASS PIKE.
ZONAL FLOW CONTINUES INTO THURSDAY WHEN OUR NEXT SYSTEM ARRIVES: A
MID LEVEL SHORTWAVE THAT SLIDES THROUGH NEW ENGLAND LATE THURSDAY
INTO FRIDAY. A MID LEVEL WARM FRONT WILL INITIALLY BRING RAIN TO
MOST OF THE REGION THURSDAY AFTERNOON, BUT ANOTHER FREEZING RAIN,
SLEET, AND RAIN MIXED PRECIPITATION EVENT IS EXPECTED SIMILAR TO
WHAT WE EXPERIENCED TONIGHT. THE MAIN CAUSE OF THIS IS THE HIGH
PRESSURE SITTING OVER SOUTHEAST QUEBEC DIRECTING COLD NE FLOW INTO
THE REGION AT THE SURFACE. MODEL SOUNDINGS SHOW THIS THIS EVOLUTION
WELL, WITH SURFACE TEMPS DROPPING BELOW FREEZING BY THURSDAY EVENING
AND ESPECIALLY OVERNIGHT WHILE A WARM NOSE REMAINS AT 850 MB (ALL
NIGHT OR PART OF THE NIGHT, DEPENDING ON LOCATION). THIS WILL LEAD
TO A MESSY MIX OF PRECIPITATION. THE BEST CHANCE OF FROZEN
PRECIPITATION IS ALONG AND NORTH OF THE MA PIKE WHERE ENSEMBLE
GUIDANCE SHOWS A 15% (LOWER ELEVATIONS) TO 60% (HIGHEST ELEVATIONS)
CHANCE OF AT LEAST 0.01" OF ICE. PRECIPITATION THEN COMES TO AN END
ON FRIDAY MORNING LEAVING A CLOUDY AND CHILLY DAY IN ITS WAKE WITH
HIGHS LIKELY NOT ESCAPING THE 30S.
KEY MESSAGE 3...PATTERN CHANGE TOWARDS MILDER WEATHER THIS WEEKEND
AND LOOKING MORE LIKELY FOR VERY WARM TEMPS NEXT WEEK.
OUR WARM-UP BEGINS IN EARNEST THIS WEEKEND AND ESPECIALLY NEXT WEEK
AS WE FALL UNDER THE INFLUENCE OF A BUILDING WESTERN ATLANTIC RIDGE.
THIS DIRECTS ANOMOLOUSLY WARM AIR INTO THE REGION WITH 850 MB TEMPS
POTENTIALLY PUSHING UP TO ~13C BY SATURDAY BEFORE DIPPING ON SUNDAY.
A WEAK FRONT ON SATURDAY NIGHT MAY BRING SOME SCATTERED SHOWERS, BUT
THESE WOULD ALL FALL AS RAIN GIVEN EXPECTED TEMPERATURE PROFILES.
STILL, ENSEMBLE PROBABILITIES HAVE BACKED OFF IN THE LAST SEVERAL
RUNS ON EVEN SEEING 50F ON SATURDAY; CONFIDENCE IN SEEING MUCH ABOVE
NORMAL TEMPS GOES UP, THOUGH, FOR MONDAY INTO TUESDAY WHEN
PROBABILITIES OF TEMPS OVER 50F ARE 90%+ LIKELY REACHING INTO THE
60S.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...
REST OF TODAY...HIGH CONFIDENCE.
LINGERING IFR CONDITIONS IN THE CT VALLEY ARE FINALLY STARTING
TO CLEAR AND SHOULD CONTINUE TO LIFT TO VFR WITHIN THE NEXT
HOURS OR SO. OTHERWISE, VFR FOR THE REST OF TODAY ACROSS
SOUTHERN NEW ENGLAND WITH LIGHT SW WINDS FOR MOST (WINDS MORE N
TO NE IN THE CT VALLEY), ASIDE FROM LOCALIZED SEA BREEZES ALONG
THE IMMEDIATE COAST FOR SOME TERMINALS.
TONIGHT...MODERATE CONFIDENCE.
VFR THIS EVENING, BUT AREAS OF LOW CLOUDS AND FOG MAY DEVELOP
LATE RESULTING IN MVFR-IFR CONDITIONS WITH EVEN LOCALIZED LIFR
CIGS/VSBYS. WHILE LOW CLOUDS AND FOG PATCHES ARE POSSIBLE
ANYWHERE LATE TONIGHT, GUIDANCE CONTINUES TO INDICATE THE
GREATEST RISK FOR IT BEING MOST WIDESPREAD ACROSS CT/RI AND
SOUTHEAST MA. LIGHT/CALM WINDS.
THURSDAY...MODERATE CONFIDENCE.
THE INITIAL MORNING LOW CLOUDS/FOG PATCHES MAY BRIEFLY BURN OFF.
WIDESPREAD MVFR TO LOCALIZED IFR CONDITIONS EXPECTED TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST, PARTICULARLY
IN THE EVENING HOURS INTO THURSDAY NIGHT WITH RAIN MIXED WITH
SOME SLEET MOVING IN. LIGHT NE WINDS.
THURSDAY NIGHT...MODERATE CONFIDENCE.
IFR/LIFR CEILINGS WITH IFR/MVFR VISBYS. FZRA AND RA EXPECTED
ACROSS THE REGION, MOVING IN FROM SW TO NE STARTING IN THE
EVENING HOURS. NE WINDS PICK UP SLIGHTLY TO BE AROUND 6-12 KT
SUSTAINED WITH OCCASIONAL GUSTS TO 20 KT POSSIBLE IN HIGHER
ELEVATIONS AND TOWARDS THE CAPE/ISLANDS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. MAIN UNCERTAINTY IS
TIMING OF CATEGORY IMPROVMENTS TOMORROW. CONFIDENCE IN ANY
SEABREEZE FOR THE REST OF THIS AFTERNOON IS VERY LOW.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. MAIN UNCERTAINTY IS
TIMING OF CATEGORY IMPROVEMENTS TOMORROW.
OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...
THURSDAY NIGHT: MAINLY IFR, WITH AREAS MVFR POSSIBLE. BREEZY.
RA, FZRA.
FRIDAY: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. CHANCE RA, FZRA
LIKELY.
FRIDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. SLIGHT CHANCE RA.
SATURDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. BREEZY. SLIGHT
CHANCE RA.
SATURDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY.
CHANCE RA.
SUNDAY: VFR. 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 THURSDAY...HIGH CONFIDENCE.
LINGERING SOUTHERLY SWELL WILL RESULT IN SMALL CRAFT SEAS LINGERING
ACROSS OUR SOUTHERN WATERS INTO THE FIRST HALF OF THE EVENING BEFORE
DROPPING BELOW CRITERIA. OTHERWISE...HIGH PRESSURE BUILDING OVER THE
WATERS TODAY AND TONIGHT WILL KEEP SUSTAINED WINDS GENERALLY 10
KNOTS OR LESS THROUGH TONIGHT. LOW PRESSURE APPROACHING FROM THE
WEST WILL ALLOW NE WINDS TO INCREASE TO BETWEEN 10 AND 20 KNOTS ON
THU.
OUTLOOK /THURSDAY NIGHT THROUGH MONDAY/...
THURSDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. RAIN. LOCAL VISIBILITY 1 TO 3 NM.
FRIDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
SATURDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF ROUGH SEAS.
SATURDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS
WITH LOCAL GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN, ISOLATED THUNDERSTORMS.
SUNDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE
OF RAIN.
BOX WATCHES/WARNINGS/ADVISORIES
CT...WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO NOON EST FRIDAY
FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO NOON EST FRIDAY
FOR MAZ002>015-026.
RI...WINTER WEATHER ADVISORY FROM 5 PM THURSDAY TO NOON EST FRIDAY
FOR RIZ001-003.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
ANZ254>256.
DISCUSSION...FRANK/BW
AVIATION...FRANK/BW/HRENCECIN
MARINE...FRANK/BW
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