853
FXUS61 KBOX 271509
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
1109 AM EDT MON APR 27 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES MADE TO THE FORECAST.
KEY MESSAGES
- QUIET WEATHER CONTINUES THROUGH TUE NIGHT WITH HIGHS MAINLY IN
THE 60S TO 70+ IN THE CT VALLEY...BUT ONLY 50S ALONG THE
IMMEDIATE COAST. LOWS IN THE 30S TO THE LOWER 40S.
- UNSETTLED WEATHER AROUND WEDNESDAY NIGHT AND THURSDAY WITH A
WELCOMED SOAKING RAIN LOOKING LIKELY.
- REMAINS UNSETTLED FRIDAY INTO THE WEEKEND WITH PARTLY TO
MOSTLY CLOUDY WEATHER, COOLER THAN NORMAL TEMPERATURES AND
POP-UP SHOWERS.
DISCUSSION
KEY MESSAGE 1...QUIET WEATHER CONTINUES THROUGH TUE NIGHT WITH
HIGHS MAINLY IN THE 60S TO 70+ IN THE CT VALLEY...BUT ONLY 50S
ALONG THE IMMEDIATE COAST. LOWS IN THE 30S TO THE LOWER 40S.
A RIDGE OF HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER
THROUGH TUE NIGHT. THIS HIGH PRESSURE SYSTEM WILL RESULT IN MAINLY
CLEAR SKIES TONIGHT WITH ANOTHER EXCELLENT NIGHT OF RADIATIONAL
COOLING. LOW TEMPS WILL DROP WELL DOWN INTO THE 30S ACROSS THE
MANY OF OUR LOCATIONS...TO THE LOWER 40S IN SOME OF THE
URBAN CENTERS. AIRMASS IS STILL QUITE DRY...BUT CAN NOT RULE OUT
SOME PATCHES OF FOG/LOW CLOUDS DEVELOPING OVERNIGHT NEAR THE COAST.
LOW CONFIDENCE ON WHETHER OR NOT THIS HAPPENS...BUT GREATEST RISK
TOWARDS THE CAPE AND ISLANDS.
PLENTY OF SUNSHINE IS EXPECTED ON TUE...ALTHOUGH DO EXPECT SOME MID-
HIGH LEVEL CLOUDINESS TO OVERSPREAD THE REGION DURING THE DAY.
ONSHORE FLOW A BIT STRONGER THAN TODAY...SO HIGH TEMPS PROBABLY A
FEW DEGREES LOWER THAN TODAY ON THE COASTAL PLAIN.
NONETHELESS...STILL EXPECT HIGHS TO REACH INTO THE 60S IN MOST
LOCATIONS AWAY FROM THE IMMEDIATE COAST. THE MILD SPOTS WILL AGAIN
BE THE CT VALLEY WHERE HIGH TEMPS OF 70+ SEEM LIKELY.
MEANWHILE...ONSHORE FLOW WILL HOLD HIGH TEMPS MAINLY IN THE LOWER TO
MIDDLE 50S ALONG THE IMMEDIATE COAST, CAPE AND ISLANDS.
MAINLY DRY AND COOL AGAIN TUE NIGHT WITH ANOTHER GOOD NIGHT OF
RADIATIONAL COOLING. LOWS WILL BE IN THE 30S IN MANY LOCATIONS WITH
LOWER 40S IN MOST URBAN CENTERS. WE WILL NEED TO WATCH FOR SOME
STRATUS AND PERHAPS SOME FOG PATCHES WORKING IN OFF THE OCEAN INTO
EASTERN MA/CAPE OVERNIGHT. PERHAPS EVEN A TOUCH OF SPOTTY
DRIZZLE/VERY LIGHT SHOWERS WORKING IN OFF THE OCEAN TOO.
KEY MESSAGE 2...UNSETTLED WEATHER AROUND WEDNESDAY NIGHT AND
THURSDAY WITH A WELCOMED SOAKING RAIN LOOKING LIKELY.
THE MORE ACTIVE PERIOD OF WEATHER TAKES SHAPE LATE WEDNESDAY
NIGHT AND ESPECIALLY INTO THURSDAY. OVERCAST SKIES BUT MAINLY
DRY WEATHER HOLDS ON FOR WED, BUT BY LATER WEDNESDAY NIGHT INTO
THURSDAY, A FRONTAL OCCLUSION WITH POSSIBLE SECONDARY LOW
PRESSURE DEVELOPMENT ALONG IT SWEEPS NNE THROUGH SOUTHERN NEW
ENGLAND. PRETTY ROBUST DYNAMICS ACTING ON A 1" PWAT AIRMASS
SHOULD BRING A WELCOMED SOAKING RAIN. SOME OF THE DETAILS ARE
STILL UNCERTAIN THIS FAR OUT, INCLUDING IF AND HOW STRONG MIGHT
A SECONDARY LOW PRESSURE DEVELOPING ON THE FRONT MIGHT BE. THAT
WOULD AFFECT RAIN AMOUNTS AND ALSO ENHANCED ESE WINDS. DID LOOK
BRIEFLY AT COASTAL FLOODING AS ASTRO TIDES START TO COME UP
THURSDAY TOO, BUT IT WOULD TAKE ABOUT A 2 FT SURGE TO GET MOST
AREAS TO MINOR COASTAL FLOODING FOR THE EVENING HIGH TIDES AND
AN EARLY LOOK SUGGESTS VALUES AROUND 1-1.3 FT, THUS LIKELY FALLING
SHORT. STILL, A GOOD SOAKING RAIN WITH MODERATE TO HIGH PROBS
OF 24 HOUR RAIN OF AT LEAST A HALF INCH, AND LOWER TO MODERATE
PROBS OF 24 HOUR RAINS OF AT LEAST AN INCH.
KEY MESSAGE 3...REMAINS UNSETTLED FRIDAY INTO THE WEEKEND WITH
PARTLY TO MOSTLY CLOUDY WEATHER, COOLER THAN NORMAL TEMPERATURES AND
POP-UP SHOWERS.
BEYOND THURSDAY...WEATHER PATTERN REMAINS UNSETTLED WITH
CYCLONIC FLOW ALOFT GOVERNING THE AREA, BRINGING A RETURN TO
COOLER THAN NORMAL TEMPERATURES AND AT LEAST SOME PARTIAL
CLOUDINESS TO OPEN THE FIRST COUPLE DAYS OF MAY. THE QUESTION IS
IF WE CAN GENERATE ANY INSTABILITY SHOWERS FOR FRIDAY INTO THE
WEEKEND UNDERNEATH THE TROUGH. EARLIER 12Z GUIDANCE WAS HINTING
AT THIS MORE BULLISHLY, BUT THE RECENT 00Z GUIDANCE HAS BACKED
OFF AND SHUNTS MOST OF THE MOISTURE OFF TOWARDS NORTHERN NEW
ENGLAND. IF SHOWERS WERE TO DEVELOP, THEY WOULDN'T NECESSARILY
BE WASHOUTS BUT COULD PRODUCE SOME GRAUPEL GIVEN THE
ANOMALOUSLY COLD AIRMASS FOR EARLY MAY (850 MB TEMPS -1 TO -4C).
HIGHS IN THE MID TO UPPER 50S WITH A MODEST WNW WIND.
AVIATION /15Z MONDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...HIGH CONFIDENCE.
MAINLY VFR CONDITIONS CONTINUE THROUGH TUE NIGHT. WE WILL NEED TO
WATCH FOR SOME SPOTTY LOW CLOUDS/FOG PATCHES TOWARDS THE
CAPE/ISLANDS OVERNIGHT...BUT NOT COMPLETELY SOLD ON IT GIVEN THE
AIRMASS IS QUITE DRY. WE ARE MORE CONCERNED ABOUT STRATUS AND
PERHAPS SOME FOG PATCHES APPROACHING THE EASTERN MA COAST, CAPE AND
ISLANDS VERY LATE TUE NIGHT. AN EASTERLY COMPONENT TO THE WINDS
CONTINUE ON THE ORDER OF 5 TO 15 KNOTS DURING THE DAYLIGHT HOURS
WITH THE STRONGEST NEAR THE COAST.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /WEDNESDAY THROUGH FRIDAY/...
TUESDAY NIGHT: VFR. BREEZY.
WEDNESDAY: VFR. SLIGHT CHANCE SHRA.
WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE
SHRA.
THURSDAY: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. SHRA, SLIGHT
CHANCE TSRA.
THURSDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY
WITH GUSTS UP TO 30 KT. CHANCE SHRA.
FRIDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH LOCAL
GUSTS UP TO 30 KT. SLIGHT CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT THROUGH TUESDAY NIGHT...HIGH CONFIDENCE.
HIGH PRESSURE CENTERED OVER THE CANADIAN MARITIMES WITH DISTANT LOW
PRESSURE WELL SOUTHEAST OF THE BENCHMARK WILL RESULT IN PERSISTENT
NE WINDS TONIGHT THROUGH TUE NIGHT. THIS LONG FETCH WILL GENERATE 3
TO 6 FOOT SEAS ACROSS THE OUTER-WATERS...SO CURRENT SMALL CRAFT
HEADLINES WILL PERSIST. SOME MARGINAL NE 20-25 KNOT WIND GUSTS
POSSIBLE FOR NANTUCKET SOUND AGAIN ON TUE...SO ANOTHER SMALL CRAFT
HEADLINE MAY NEED TO BE POSTED FOR TUE ONCE THE CURRENT ONCE EXPIRES
THIS EVENING FOR THAT REGION.
OUTLOOK /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. SLIGHT
CHANCE OF RAIN SHOWERS.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
CHANCE OF RAIN SHOWERS.
THURSDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. RAIN
SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
THURSDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS UP TO 5 FT. CHANCE OF RAIN SHOWERS.
FRIDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ232.
SMALL CRAFT ADVISORY FROM 2 AM TUESDAY TO 2 AM EDT WEDNESDAY
FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR ANZ254>256.
DISCUSSION...FRANK/LOCONTO
AVIATION...FRANK
MARINE...FRANK/LOCONTO
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