550
FXUS61 KBOX 220601
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
201 AM EDT FRI MAY 22 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
- COOLER AND DRY WEATHER THROUGH SATURDAY. TURNING OVERCAST WITH
EVEN COOLER TEMPS (60S) FOR SATURDAY, WITH RAIN DEVELOPING LATER
SATURDAY EVENING.
- COOL WITH WIDESPREAD RAIN SUNDAY.
- WARMING TREND NEXT WEEK. SCATTERED SHOWERS LINGERING MONDAY WITH
ANOTHER CHANCE OF SHOWERS WED.
DISCUSSION
KEY MESSAGE 1...COOLER AND DRY WEATHER THROUGH SATURDAY. TURNING
OVERCAST WITH EVEN COOLER TEMPS (60S) FOR SATURDAY, WITH RAIN
DEVELOPING LATER SATURDAY EVENING.
THE SURFACE HIGH PRESSURE OVER THE GREAT LAKES EXPANDS OVER NEW
ENGLAND ON FRIDAY AND SATURDAY WITH SUBSIDENCE KEEPING THINGS DRY
AND SUNNY TO START. FRIDAY WILL FEATURE SUNNY SKIES, COOL ONSHORE
BREEZES, AND HIGH TEMPERATURES IN THE MID 60S TO LOW 70S. THE
EXCEPTION WILL BE ALONG THE IMMEDIATE COAST WHERE THOSE SEABREEZES
KEEP TEMPS IN THE UPPER 50S TO LOW 60S. THIS COOLER AIRMASS WITH
850MB TEMPS IN THE 2-3C RANGE DOESN'T CHANGE MUCH OVER THE COURSE OF
THE NEXT 48 HOURS, BUT SATURDAY WILL BE COOLER IF MAINLY DUE TO
INCREASED CLOUDCOVER AS MOISTURE STREAMS OVERHEAD AHEAD OF OUR NEXT
WET WEATHER SYSTEM. THE DRY AIR IN THE LOW/MID LEVELS AND STUBBORN
HIGH PRESSURE WILL KEEP THE RAIN AT BAY FOR MUCH OF THE REGION ON
SATURDAY, SO WHILE IT WILL BE COOL AND CLOUDY, MANY OF THOSE WITH
OUTDOOR PLANS SHOULD BE ABLE TO KEEP THEM. THE MOST LIKELY TO STAY
DRY WILL BE AREAS RI NORTH AND EAST, WITH A BETTER CHANCE FOR
AFTERNOON OR EVENING RAIN FURTHER WEST IN CT AND MA.
KEY MESSAGE 2...COOL WITH WIDESPREAD RAIN SUNDAY.
WIDESPREAD WARM FRONTAL PRECIPITATION OVERSPREADS THE REGION
SATURDAY EVENING/NIGHT AND CONTINUES ALL DAY SUNDAY AS AN AREA OF
LOW PRESSURE TRAVERSES THE REGION. IT BRINGS WITH IT AMPLE MOISTURE
(PWATS APPROACHING 1.75", IN THE 99TH PERCENTILE OF CLIMATOLOGY) AND
FORCING WITH 35-50 KT LLJ WHICH WILL ALSO SERVE TO MAKE IT GUSTY,
ESPECIALLY OVER THE WATERS. BEFORE ALL IS SAID AND DONE, MOST
LOCATIONS ARE LIKELY TO PICK UP A HALF INCH TO AN INCH OF RAIN BY
SUNDAY NIGHT. SUNDAY WILL ALSO BE THE COLDEST DAY OF THE FORECAST,
WITH RAINY, CLOUDY CONDITIONS LEADING TO HIGHS IN THE 50S.
KEY MESSAGE 3...WARMING TREND NEXT WEEK. SCATTERED SHOWERS LINGERING
MONDAY WITH ANOTHER CHANCE OF SHOWERS WED.
THE MEMORIAL DAY FORECAST IS BY NO MEANS SETTLED, BUT IT LOOKS MORE
FAVORABLE THAN SUNDAY AT THE VERY LEAST. SOME OF THE GUIDANCE
INCLUDING THE ECMWF ARE A BIT DRIER WITH THE LOW EXITING AND DRIER
CONDITIONS FOR MONDAY, WHILE THE GFS CONTINUES TO BE THE WETTEST
SOLUTION WITH THE FOLLOW-UP SHORTWAVE MORE ROBUST LEADING TO ANOTHER
WET DAY. LEANING ON ENSEMBLE GUIDANCE FOR NOW, THOUGH THE EPS AND
GEFS ARE ALSO IN DIFFERENT CAMPS WITH A 10-20% AND 40-50% CHANCE OF
AOA 0.10" OF RAIN MONDAY RESPECTIVELY. WHAT IS MORE CERTAIN IS THAT
MONDAY WILL BE THE START OF A WARM-UP WITH ZONAL FLOW AT 500 MB AND
A SURGE OF 850 MB TEMPS CLOSER TO 12-13C. THIS WILL MEAN HIGHS BACK
IN THE 70S AND LOW 80S BY TUESDAY. OUR NEXT SHORTWAVE ARRIVES AROUND
MIDWEEK BUT DETAILS ARE UNCLEAR AT THIS POINT.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE...
FRIDAY...HIGH CONFIDENCE.
VFR. NE WINDS 8-15 KT, WITH GUSTS TO 20 KT CAPE/ISLANDS
DIMINISHING IN THE AFTERNOON. SEA-BREEZES DEVELOPING ON THE
EASTERN MA COAST.
FRIDAY NIGHT...HIGH CONFIDENCE.
VFR. INCREASING MID AND HIGH-LEVEL CLOUDS. NE WINDS LESS THAN 5
KT.
SATURDAY...HIGH CONFIDENCE.
VFR. SE WINDS 5 TO 10 KTS. CIGS LOWERING FROM WEST TO EAST
THROUGH THE AFTERNOON AND EVENING AHEAD OF -SHRA.
KBOS...HIGH CONFIDENCE IN TAF.
KBDL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY NIGHT: VFR. BREEZY. SHRA LIKELY.
SUNDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. SHRA.
SUNDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. CHANCE
SHRA.
MEMORIAL DAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. CHANCE SHRA.
MONDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT
CHANCE SHRA.
TUESDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH
AT LEAST MIDDAY SAT. NE TO E WINDS THROUGH FRI NIGHT AROUND
10-15 KT, WITH E/ESE WINDS AT SIMILAR SPEEDS FOR THE SOUTHERN
WATERS, AND SEAS 4 FT OR LESS ALL WATERS.
INTO SAT OF THE HOLIDAY WEEKEND, ESE WINDS AROUND 15-20 KT WITH
FRINGE SMALL CRAFT ADVISORY WINDS/SEAS OVER THE SOUTHERN WATERS
ESPECIALLY LATER IN THE DAY. RAIN WILL ALSO DEVELOP AROUND LATE
SAT/SAT NIGHT OVER THE SOUTHERN WATERS. INCREASING, MORE SOLID-SCA
E/SE WINDS 25-30 KT AND SEAS 5-9 FT (HIGHER SOUTHERN WATERS OVER THE
OPEN-OCEAN) THEN DEVELOP FOR SUNDAY FOR YOUR HOLIDAY BOATING PLANS,
TO GO ALONG WITH STEADY RAIN WHICH COULD REDUCE VISIBILITY.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY: WINDS LESS THAN 25 KT.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. SEAS LOCALLY APPROACHING 5 FT. CHANCE OF
RAIN SHOWERS.
SUNDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. AREAS OF ROUGH SEAS. RAIN SHOWERS.
SUNDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. AREAS OF ROUGH SEAS. RAIN SHOWERS LIKELY.
MEMORIAL DAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS.
CHANCE OF RAIN SHOWERS.
MONDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT
CHANCE OF RAIN SHOWERS.
TUESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...BW
AVIATION...BW
MARINE...BW
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