320
FXUS61 KBOX 041107
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
607 AM 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 /12Z WEDNESDAY THROUGH SUNDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE...
TODAY...MODERATE CONFIDENCE.
IFR-LIFR CONDITIONS IN AREAS OF LOW CLOUDS AND FOG LINGER INTO
EARLY THIS MORNING IN SPOTS. WHILE WE DO EVENTUALLY EXPECT
IMPROVEMENT TO VFR CONDITIONS...TIMING IS UNCERTAIN AND GIVEN
WEAK BOUNDARY LAYER WINDS THIS COULD BE A SLOW PROCESS
ESPECIALLY IN LOW- LYING LOCATIONS SUCH AS THE CT RIVER VALLEY.
MOST LOCATIONS SHOULD BE VFR BY AFTERNOON EXCEPT PERHAPS PARTS
OF THE LOWER CT RIVER VALLEY. WINDS BECOMING LIGHT WSW...BUT WE
MAY SEE SOME LOCALIZED SEA BREEZES ALONG PORTIONS OF THE
IMMEDIATE COAST THIS AFTERNOON.
TONIGHT...MODERATE CONFIDENCE.
VFR CONDITIONS IN THE 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 SEEMS TO BE INDICATING 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.
HOWEVER...WIDESPREAD MVFR TO LOCALIZED IFR CONDITIONS TO OVERSPREAD
THE REGION FROM SOUTHWEST TO NORTHEAST ALONG WITH A SHIELD OF RAIN
THAT MAY BE MIXED WITH SLEET ESPECIALLY NORTH OF THE MA TURNPIKE.
LIGHT NE WINDS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. THE MAIN UNCERTAINTY
IS IF WINDS MAY BE WEAK ENOUGH FOR LOCALIZED SEA BREEZES TO
DEVELOP FOR SEVERAL HOURS THIS AFTERNOON.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. THE MAIN UNCERTAINTY
IS HOW LONG IT TAKES THE LOW CLOUDS AND FOG TO BURN OFF THIS MORNING.
LOW RISK THIS MAY EVEN TAKE UNTIL SOMETIME THIS AFTERNOON.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
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 SUNDAY/...
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...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
ANZ254>256.
DISCUSSION...FRANK/BW
AVIATION...FRANK/BW
MARINE...FRANK/BW
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