740
FXUS61 KBOX 131121
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
721 AM EDT FRI MAR 13 2026
WHAT HAS CHANGED
CONFIDENCE CONTINUES TO GROW IN THE LIKELIHOOD FOR AT LEAST SOME
WIND HEADLINES SATURDAY. OTHERWISE, NO SIGNIFICANT CHANGES.
KEY MESSAGES
- DRY & SEASONABLY COOL TODAY. A FEW BRIEF PASSING RAIN/SNOW
SHOWERS TONIGHT WITH FOCUS ACROSS NORTHERN MA.
- STRONG WESTERLY WIND GUSTS OF 35-55 MPH ON SAT...WIND
HEADLINE WILL LIKELY BE NEEDED AT LEAST FOR PARTS OF THE
REGION.
- A PERIOD OF HEAVY RAINFALL, STRONG WINDS AND UNSEASONABLY MILD
TEMPS MON INTO MON NIGHT. SOME RIVER AND SMALL STREAM
FLOODING EXPECTED.
- TRENDING COLDER WITH MAINLY DRY WEATHER TUE THROUGH THU.
DISCUSSION
KEY MESSAGE 1...DRY & SEASONABLY COOL TODAY. A FEW BRIEF
PASSING RAIN/SNOW SHOWERS TONIGHT WITH FOCUS ACROSS NORTHERN
MA.
POST FRONTAL/DRY AIRMASS OVERSPREADING THE REGION EARLY THIS
MORNING, ON GUSTY NW WINDS 25 TO 35 MPH DURING THE PREDAWN
HOURS. STRONG CAA WITH 850 MB TEMPS LOWERING TO -10C TO -12C
EARLY THIS MORNING, YIELDING LOWS IN THE 20S BEFORE SUNRISE,
ALONG WITH COLDER WIND CHILLS. ALTHOUGH, PARTLY TO MOSTLY SUNNY
CONDITIONS LATER THIS MORNING, COMBINED WITH DIMINISHING WINDS
WILL TAKE THE EDGE OFF THE COOL TEMPS. HIGHS THIS AFTERNOON WILL
BE IN THE 40S, WHICH IS JUST ABOUT ON TRACK FOR THIS TIME OF
YEAR. FAST/PROGRESSIVE FLOW ALOFT YIELDS A WAA PATTERN
OVERSPREADING THE REGION THIS AFTERNOON, YIELDING INCREASING
CLOUDS AND SW WINDS INCREASING 15-20 MPH. HENCE, MORNING HOURS
BRIGHTER THAN THE AFTERNOON.
A SHORTWAVE AND ASSOCIATED WARM FRONT WILL LIKELY BRING A FEW
BRIEF PASSING RAIN/SNOW SHOWERS TO THE REGION
TONIGHT...PARTICULARLY ACROSS NORTHERN MA.
KEY MESSAGE 2...STRONG WESTERLY WIND GUSTS OF 40-50 MPH ON SAT.
WIND HEADLINES WILL LIKELY BE NEEDED AT LEAST FOR PARTS OF THE
REGION.
MAINLY DRY WEATHER SATURDAY, WITH PARTLY TO MOSTLY SUNNY
CONDITIONS, BUT WINDY AND CHILLY. DEEPENING LOW OVER THE
MARITIMES WILL YIELD A STRONG PGRAD ALONG WITH STRONG CAA.
INCREASING MARCH SUN ANGLE WILL COMBINE WITH STRONG CAA TO
YIELD STEEP LOW LEVEL LAPSE RATES. MODEL SOUNDINGS SUPPORT WNW
WINDS GUSTING UP TO 40 TO 50. THUS, WIND HEADLINES MAY BE
REQUIRED. GIVEN THE AFOREMENTIONED ATTRIBUTES, OUR WIND
FORECAST INCORPORATES SOME OF THE HIGHER GUIDANCE (NBM 90
PERCENTILE), SUPPORTING WIND GUSTS UP TO 40-50 MPH AT TIMES
SAT. SEASONABLY COOL WITH HIGHS IN THE MID TO UPPER 40S, BUT
FEELING MUCH COOLER GIVEN THE STRONG WINDS.
KEY MESSAGE 3...A PERIOD OF HEAVY RAINFALL, STRONG WINDS AND
UNSEASONABLY MILD TEMPS MON INTO MON NIGHT. SOME RIVER AND SMALL
STREAM FLOODING EXPECTED.
GUIDANCE HAS TRENDED A BIT SLOWER WITH THE HEAVY RAINFALL AND
WIND EVENT AND IS MORE FOCUSED IN THE MONDAY TO MONDAY NIGHT
PERIOD. INITIAL WAVE OF SHOWERS WILL OVERSPREAD THE REGION LATE
SUN NIGHT INTO MON ASSOCIATED WITH THE LOW LEVEL JET AND
MOISTURE TRANSPORT LIFTING NORTHWARD INTO THE REGION. WINDS WILL
ALSO RAMP UP IN THIS PERIOD BUT THE PERIOD OF STRONGEST WINDS
AND HEAVIEST RAINFALL WILL LIKELY COME LATE MON AND ESPECIALLY
MON NIGHT WITH THE SECOND AND STRONGER LLJ AHEAD OF THE
ADVANCING COLD FRONT. WIND AND PWAT ANOMALIES ARE 3-4 SD ABOVE
NORMAL WHICH IS A PRETTY STRONG SIGNAL FOR HEAVY RAINFALL AND
STRONG WINDS. THE OTHER WILDCARD IS THE POTENTIAL FOR CONVECTIVE
ELEMENTS AND A FEW T-STORMS AND CAN'T RULE OUT A FINE LINE OF
CONVECTION ALONG THE COLD FRONT MON NIGHT GIVEN STRONG FORCING
FOR ASCENT AND ELEVATED INSTABILITY. WE ARE EXPECTING 1-2 INCHES
OF RAIN WITH LOCALIZED 3 INCH AMOUNTS IF CONVECTION GETS
INVOLVED. 90TH PERCENTILE OF THE ENSEMBLE GUIDANCE IS INDICATING
UP TO 3 INCHES WHICH WOULD BE A WORST CASE SCENARIO BUT THINK
THESE HIGHER AMOUNTS WOULD BE LOCALIZED.
THE EXPECTED RAINFALL AMOUNTS WOULD BE ENOUGH TO CAUSE FLOOD
CONCERNS ALONG SOME RIVERS AND SMALL STREAMS. MMEFS ENSEMBLE
GUIDANCE FROM THE NAEFS CONTINUE TO SHOW SEVERAL RIVERS REACHING
FLOOD STAGE, ESPECIALLY THE PAWTUXET, PAWCATUCK AND WOOD RIVERS
IN RI. PROBS ARE 60-80% FOR MINOR FLOODING AND THERE ARE EVEN
LOW PROBS (20-30%) OF MODERATE FLOODING. OTHER RIVERS TO WATCH
FOR POTENTIAL MINOR FLOODING INCLUDE THE ASSABET RIVER AT
MAYNARD, DEERFIELD RIVER AT WEST DEERFIELD AND THE LOWER REACHES
OF THE CT RIVER FROM HARTFORD TO MIDDLE HADDAM.
REGARDING STRONG WIND POTENTIAL, WHILE WINDS WILL BE INCREASING
MONDAY THE GREATEST CONCERN FOR A PERIOD OF STRONG TO DAMAGING WIND
GUSTS WILL BE MON NIGHT AHEAD OF THE COLD FRONT. SOME OF THE GLOBAL
GUIDANCE IS INDICATING A 70-80 KT LLJ WHICH IS PRETTY IMPRESSIVE AT
THIS TIME RANGE, BUT IT'S ALWAYS A CHALLENGE DETERMINING HOW MUCH
WIND WILL MIX DOWN TO THE SURFACE WITH THESE SOUTHERLY LLJ EVENTS.
TEMPS WILL LIKELY MAKE A RUN AT 60 OR EVEN LOWER 60S LATE MON INTO
MON EVENING WHICH WOULD INCREASE POTENTIAL FOR STRONG TO DAMAGING
GUSTS. ALSO, ANY FINE LINE WOULD HELP TO MIX DOWN STRONGER WINDS.
THESE ARE FACTORS THAT WE WILL HAVE A BETTER HANDLE ON THIS WEEKEND.
KEY MESSAGE 4...TRENDING COLDER WITH MAINLY DRY WEATHER TUE THROUGH
THU.
LOOKS MAINLY DRY ON TUE BUT THIS WILL DEPEND ON THE COLD FRONT
MOVING TO THE EAST BY TUE MORNING. IF TIMING OF FROPA IS FURTHER
DELAYED IT'S POSSIBLE SHOWERS COULD LINGER INTO TUE MORNING,
ESPECIALLY IN THE EAST. OTHERWISE, DRYING OUT AND TURNING COOLER AND
BLUSTERY TUE BEHIND THE COLD FRONT. CORE OF COLDEST AIR ALOFT WILL
BE OVER NEW ENG ON WED WHICH WILL BE THE COLDEST DAY OF THE WEEK
WITH HIGHS MOSTLY IN THE 30S, WITH SLIGHT MODERATION ON THU.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY...HIGH CONFIDENCE.
VFR, THOUGH WITH INCREASING MID-LEVEL CLOUDS AS THE DAY WEARS
ALONG. WNW WINDS BECOMING SW THIS AFTERNOON AT 7-13 KNOTS.
TONIGHT...HIGH CONFIDENCE.
VFR DOMINATES...BUT BRIEF MVFR CONDITIONS POSSIBLE MAINLY LATER
TONIGHT IN A FEW BRIEF PASSING RAIN/SNOW SHOWERS. GREATEST RISK
FOR THIS WILL BE ACROSS NORTHERN MA. SOUTHERLY WIND GUSTS
INCREASING TO BETWEEN 20 AND 30 KNOT FOR A TIME OVERNIGHT.
SATURDAY...HIGH CONFIDENCE.
MAINLY VFR CONDITIONS EXPECTED OUTSIDE A FEW BRIEF PASSING
RAIN/SNOW SHOWERS POSSIBLE MAINLY IN NORTHWEST MA. WESTERLY WIND
GUSTS OF 30-40 KNOTS WITH A FEW GUSTS UP TO 45 KNOTS POSSIBLE
ACROSS THE HIGHER TERRAIN.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
SUNDAY: VFR. BREEZY.
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. WINDY WITH
GUSTS UP TO 35 KT. CHANCE RA, SLIGHT CHANCE FZRA.
MONDAY: MAINLY MVFR, WITH AREAS IFR POSSIBLE. STRONG WINDS WITH
GUSTS UP TO 40 KT. RA, ISOLATED TSRA.
MONDAY NIGHT: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. STRONG
WINDS WITH GUSTS UP TO 45 KT. RA.
TUESDAY: VFR. WINDY WITH GUSTS UP TO 35 KT. SLIGHT CHANCE RA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
ROUGH SEAS LINGER ACROSS THE OUTER COASTAL WATERS INTO FRIDAY
MORNING. WINDS EXPECTED TO BRIEFLY DIMINISH FRIDAY AFTERNOON,
BEFORE INCREASING ONCE MORE FROM THE SOUTH FRIDAY NIGHT.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
AREAS OF GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.
SUNDAY: WINDS LESS THAN 25 KT.
SUNDAY NIGHT: LOW RISK FOR GALE FORCE WINDS WITH GUSTS UP TO
35 KT. LOCAL ROUGH SEAS. CHANCE OF RAIN.
MONDAY: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH SEAS UP
TO 16 FT. RAIN, ISOLATED THUNDERSTORMS.
MONDAY NIGHT: GALE FORCE WINDS WITH GUSTS UP TO 45 KT. ROUGH
SEAS UP TO 18 FT. RAIN.
TUESDAY: STRONG WINDS WITH GUSTS UP TO 35 KT. ROUGH SEAS UP TO
13 FT. CHANCE OF RAIN.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
ANZ231>235-237-251.
GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR ANZ232>235-237.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ250-
256.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ254-
255.
GALE WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR
ANZ254>256.
DISCUSSION...KJC/FRANK/NOCERA
AVIATION...FRANK/NOCERA
MARINE...NOCERA
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