612
FXUS61 KBOX 290808
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
408 AM EDT FRI MAY 29 2026
WHAT HAS CHANGED
INCREASING CONFIDENCE IN STRONG GUSTY WINDS ON SATURDAY,
ESPECIALLY ACROSS EASTERN COASTAL AREAS. WIND ADVISORY ISSUED
FOR NORTHEAST MA, EAST COAST AND CAPE AND ISLANDS. ADJACENT
AREAS TO COAST STILL BEING CONSIDERED FOR HEADLINES. HELD OFF
DUE TO LARGER UNCERTAINTY.
KEY MESSAGES
- DRY FOR FIRST HALF OF TODAY WITH SHOWERS DEVELOPING LATE AFTERNOON
TO EARLY EVENING. LOW PRESSURE SYSTEM BRINGS RAIN AND GUSTY STRONG
WINDS TONIGHT AND SATURDAY.
- MAINLY DRY SUNDAY. UNSETTLED CONDITIONS RETURN BY MONDAY CONTINUING
THROUGH MID WEEK WITH PERIODIC CHANCES FOR SHOWERS AND COOLER
TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...DRY FOR FIRST HALF OF TODAY WITH SHOWERS DEVELOPING
LATE AFTERNOON TO EARLY EVENING. LOW PRESSURE SYSTEM BRINGS RAIN AND
GUSTY STRONG WINDS TONIGHT AND SATURDAY.
THERE IS A GOOD CONSENSUS AMONG ENSEMBLE GUIDANCE FOR A BLOCKY UPPER
LEVEL PATTERN TO SET UP OVER THE NORTHEAST TODAY THROUGH EARLY NEXT
WEEK. SEVERAL SHORTWAVES MOVE THROUGH THE BROAD CYCLONIC FLOW ALOFT
BRINGING PERIODIC CHANCES FOR SHOWERS/RAIN.
THE FIRST WAVE FEATURES AN ANOMALOUS CLOSED UPPER LOW THAT DROPS
SOUTH ACROSS SOUTHERN NEW ENGLAND TONIGHT INTO SATURDAY. THE FIRST
HALF OF TODAY SHOULD REMAIN DRY WITH SCATTERED WARM FRONTAL SHOWERS
DEVELOPING LATER IN THE AFTERNOON AND EVENING. HIGH TEMPERATURES
WILL LIKELY BE SIMILAR TO THURSDAY IN THE UPPER 60S TO LOW 70S, WITH
SOME LOCATIONS IN THE MID 70S IN THE CT VALLEY. SHOWERS BECOME MORE
WIDESPREAD THIS EVENING AND TONIGHT WITH A FEW WAVES OF RAIN. THERE
IS VERY MARGINAL INSTABILITY PRESENT, WHICH MAY SUPPORT A FEW
EMBEDDED WEAK STORMS OR DOWNPOURS. THERE MAY BE A LULL SOMETIME
OVERNIGHT IN BETWEEN WAVES OF SHOWERS. AS THE LOW PRESSURE ROTATES
THROUGH IT WILL SHIFT ANOTHER ROUND OF SHOWERS SATURDAY MORNING.
SHOWERS SLOWLY DIMINISH AS THE LOW EXITS FURTHER OFFSHORE MID TO
LATE AFTERNOON. IT'S POSSIBLE FOR SHOWERS TO LINGER AS LATE AS THE
EVENING FOR THE OUTER CAPE/ISLANDS.
FOR RAIN TOTALS, ENSEMBLES RANGE RAIN TOTALS 0.20" TO 1.1" ACROSS
THE 25TH TO 75TH PERCENTILE RANGE WITH THE HIGHER AMOUNTS FAVORED IN
NORTHEAST MA. WHILE WE ARE ALREADY IN COOL TROUGHY FLOW, THE PASSAGE
OF THIS DEEP UPPER LOW WILL SHIFT A CORE OF ANOMALOUSLY COLD AIR
ALOFT ACROSS THE REGION SATURDAY. THIS WILL BRING US A FAIRLY COOL
DAY FOR LATE-MAY WITH HIGHS IN THE UPPER 40S AND LOW 50S. WITH THE
TIMING OF THE COLDER AIR AND THE SHOWERS, SOME MODEL GUIDANCE HINTS
AT POTENTIAL FOR A FEW SNOWFLAKES MIXING IN AT THE HIGHER
ELEVATIONS. IF THE COLD AIR ARRIVES IN A SIMILAR PERIOD OF BETTER
PRECIP RATES SOME SPOTS MAY COOL ENOUGH TO MIX IN SOME WET FLAKES.
THE NAM HAS SHOWN THE STRONGEST SIGNAL FOR THIS, BUT ALSO SHOWS A
COLDER AIRMASS IN PLACE WITH A WIDER FOOTPRINT COMPARED TO OTHER
GUIDANCE (TEMPS - UPPER 30S). SO OVERALL, CAN'T RULE OUT A WINTRY
MIX IN THE HIGHEST ELEVATIONS OF THE INTERIOR ALTHOUGH LITTLE IMPACT
EXPECTED.
THE BIGGER CONCERN WITH THIS SYSTEM IS THE STRONG WINDS. AS THE
SURFACE LOW PRESSURE TRACKS OFFSHORE, IT DEEPENS WITH A TIGHTENED
PRESSURE GRADIENT AND 45-60 KT 925MB LLJ. IF WINDS MIX EFFICIENTLY,
STRONG GUSTY N TO NE WINDS WILL BLANKET THE REGION. ENSEMBLE
GUIDANCE RANGES GUSTS 35-45 MPH WITH POTENTIAL FOR ISOLATED HIGHER
GUSTS (45-55 MPH) ALONG THE EAST COAST AND CAPE AND ISLANDS. THIS
SEEMS REASONABLE GIVEN THAT THE LLJ JET MORE LIKELY SHIFTS ACROSS
EAST SOUTHERN NEW ENGLAND THROUGH THE DAY. THE DEGREE OF MIXING IS
STILL UNCERTAIN WHICH HAS LED TO SPREAD ACROSS GUIDANCE IN GUST
MAGNITUDE AND THE EXTENT INLAND THE HIGHER MAGNITUDE GUSTS MAY
EXTEND. ACROSS ENSEMBLE GUIDANCE, THE ECMWF HAS BEEN CONSISTENTLY
STRONG WITH GUSTS COMPARED TO THE GEFS. HREF MEAN GUSTS SHOW SOME
AREAS ACROSS THE EAST ABOVE 45 MPH, MAINLY CONFINED TO THE COASTAL
AREAS AND CAPE/ISLANDS. RIGHT NOW THE RISK FOR ADVISORY CRITERIA IS
GREATER ACROSS NORTHEAST MA, EXTENDING DOWN THE EAST COASTAL REGION
AND INTO THE SOUTH COAST/BLOCK ISLAND, SOUTHEAST MA AND
CAPE/ISLANDS. CAPE AND ISLANDS AND THE NEAR-COASTAL AREAS HAVE THE
GREATER CONFIDENCE AT THE MOMENT BASED ON GUIDANCE, SO WENT WITH
ADVISORY TO START. REMAINING AREAS JUST OUTSIDE THOSE ZONES WILL
NEED TO BE CONSIDERED TODAY.
KEY MESSAGE 2...MAINLY DRY SUNDAY. UNSETTLED CONDITIONS RETURN BY
MONDAY CONTINUING THROUGH MID WEEK WITH PERIODIC CHANCES FOR
SHOWERS AND COOLER TEMPERATURES.
A FEW MORE WAVES MOVE THROUGH THE UPPER TROUGH PATTERN ALOFT BEYOND
SUNDAY INTO EARLY NEXT WEEK. THERE IS STILL SPREAD IN THE DETAILS OF
THE WAVES SUCH AS THE TIMING, BUT THEY WILL SUPPORT PERIODIC CHANCES
FOR SHOWERS AT LEAST THROUGH MID-WEEK. THERE IS A BETTER CONSENSUS
ON SHOWERS SUN NIGHT INTO MON AS A CLOSED LOW TRACKS ACROSS THE
REGION. REMAINING DAYS EARLY WEEK COULD SEE SCATTERED SHOWERS,
PERHAPS AN ISOLATED STORM. 850MB TEMPERATURES ANOMALIES LEAN BELOW
NORMAL EARLY NEXT WEEK LIKELY YIELDING TEMPERATURES IN THE 60S AND
LOW 70S THROUGH WEDNESDAY. THERE ARE SIGNS OF THE BLOCKY PATTERN
BREAKING DOWN LATER NEXT WEEK WHICH SHOULD HELP WARM TEMPERATURES
BACK UP.
AVIATION /08Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE:
THROUGH 12Z: HIGH CONFIDENCE.
VFR. NW WINDS 6-11 KTS.
FRIDAY: OVERALL HIGH CONFIDENCE, BUT LOWER CONFIDENCE ON WIND
DIRECTIONS FOR BOS.
VFR. NW WINDS 6-12 KTS FOR INLAND TERMINALS WITH A FEWS GUSTS UP
TO 20 KTS. AS SEABREEZE GETS GOING ALONG EASTERN MA COAST/BOS
15-17Z WITH SE WINDS 8-12 KT. SCATTERED SHOWERS POSSIBLE AFTER
20Z FOR TERMINALS. INCLUDED AS A PROB30 GIVEN SCATTERED NATURE
OF SHOWERS AND LOWER CONFIDENCE IN COVERAGE. IF ISOLATED
SHOWERS DEVELOP, WIND SPEED/DIRECTIONS COULD BECOME VARIABLE FOR
PERIODS, ESPECIALLY AT BOS. FOR OTHER TERMINALS, WINDS SHIFT TO
THE W/SW AT 8-12 KTS.
FRIDAY NIGHT: MODERATE CONFIDENCE.
VFR TO START WITH PATCHY MVFR POSSIBLE FIRST HALF OF NIGHT.
THERE WILL LIKELY BE A LULL IN SHOWERS AFTER 06Z WITH
IMPROVEMENTS IN CEILINGS POSSIBLE FOR INTERIOR TERMINALS. ROUND
OF WIDESPREAD LIGHT TO MODERATE RAIN SHIFTS SOUTH 09-15Z SAT.
CEILINGS MAY DROP INTO MVFR CATEGORY AS WELL AS VISIBILITIES.
WINDS START OFF W/SW AROUND 5-10 KT, BUT THEN SHIFT TO W/NW
THROUGH 06Z. WINDS AT BED/BOS AND INCREASE TO AROUND 10-15 KT
WITH GUSTS TO 25 KT AFTER 09Z.
KBOS...MODERATE CONFIDENCE IN TAF. NW WINDS PREVAIL THRU
15-16Z, WITH SE SEABREEZES DEVELOPING AFTER. ISOLATED SHRA
COULD DEVELOP IN/AROUND BOS ONCE SEABREEZES DEVELOP DURING THE
AFTERNOON, AND IF THEY DO, IT COULD MAKE FOR VARIABLE WIND
DIRECTIONS IN/NEAR SHRA. SE WINDS SHOULD PREVAIL OUTSIDE OF
SHRA.
KBDL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. STRONG WINDS
WITH AREAS OF GUSTS UP TO 40 KT. CHANCE SHRA, PATCHY BR.
SATURDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.
SUNDAY: VFR.
SUNDAY NIGHT: VFR. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
MONDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
MONDAY NIGHT: VFR. CHANCE SHRA.
TUESDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY AND TONIGHT...
GENERALLY TRANQUIL WITH WAVE HEIGHTS BETWEEN 1 AND 3 FEET FOR
MOST OF THE WATERS. WINDS FROM THE NW BETWEEN 5 AND 15 MPH WITH
GUSTS UP TO 20 MPH. WINDS AND SEAS INCREASING FROM THE NORTH
EARLY SATURDAY MORNING.
SATURDAY INTO SATURDAY NIGHT...
GALE WARNING FOR ALL THE WATERS ON SATURDAY AS A STRONG LOW
PRESSURE SYSTEM TRACKS ACROSS THE REGION BRINGING GUSTY N-NE
WINDS. THERE IS EVEN A CHANCE FOR AREAS OF STORM FORCE WINDS
WITH A STRONGER AREA OF LOW PRESSURE.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: MODERATE RISK FOR GALE FORCE WINDS WITH GUSTS UP TO
45 KT. ROUGH SEAS UP TO 12 FT. CHANCE OF RAIN SHOWERS, PATCHY
FOG.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS.
SUNDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE OF
RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
MONDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
MONDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. CHANCE OF RAIN SHOWERS.
TUESDAY: WINDS LESS THAN 25 KT. CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...WIND ADVISORY FROM 10 AM TO 8 PM EDT SATURDAY FOR MAZ007-015-
016.
WIND ADVISORY FROM 10 AM SATURDAY TO 8 PM EDT SUNDAY FOR
MAZ019-021>024.
RI...NONE.
MARINE...GALE WARNING FROM 2 AM TO 8 PM EDT SATURDAY FOR ANZ230>237-250-
251-254>256-280>283.
DISCUSSION...MENSCH
AVIATION...MENSCH
MARINE...MENSCH
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