591
FXUS61 KBOX 272309
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
709 PM EDT WED MAY 27 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO THE FORECAST.
KEY MESSAGES
- A FEW SHOWERS AND POSSIBLY A THUNDERSTORM THROUGH EARLY
EVENING, MAINLY SOUTH OF THE MA PIKE TO THE SOUTH COAST.
- COOLER THURSDAY WITH SCATTERED SHOWERS DEVELOPING IN THE
AFTERNOON, ESPECIALLY ACROSS EASTERN MA.
- BROAD CYCLONIC FLOW OVER NORTHEASTERN NORTH AMERICA WILL
SUPPORT UNSETTLED WEATHER IN SOUTHERN NEW ENGLAND FRIDAY
THROUGH THE MIDDLE OF NEXT WEEK
DISCUSSION
KEY MESSAGE 1...A FEW SHOWERS AND POSSIBLY A THUNDERSTORM
THROUGH EARLY EVENING, MAINLY SOUTH OF THE MA PIKE TO THE SOUTH
COAST.
COLD FRONT WILL BE MOVING SOUTH ACROSS SNE THIS AFTERNOON
REACHING THE SOUTH COAST THIS EVENING. WEAK INSTABILITY DEVELOPS
AHEAD OF THE FRONT WITH MLCAPES 250-500 J/KG. INSTABILITY IS
WEAK BUT LOW LEVEL CONVERGENCE WITH THE FRONT MAY BE ENOUGH FOR
ISOLATED LOW TOPPED CONVECTION TO DEVELOP LATER THIS AFTERNOON
AND EVENING, MAINLY SOUTH OF THE MA PIKE. THE 3KM NAM AND NSSL-
WRF ARE MOST AGGRESSIVE WITH SCATTERED STORMS DEVELOPING WHILE
HRRR, WRF-ARW AND RRFS SHOW LITTLE TO NO CONVECTION. ONE OF THE
MAIN LIMITING FACTORS IS DRY AIR IN THE MID LEVELS WHICH WILL
SERVE TO SUPPRESS STRONGER UPDRAFTS FROM DEVELOPING, ESPECIALLY
GIVEN JUST WEAK INSTABILITY. SO WHILE WE CAN'T RULE OUT A FEW
SHOWERS OR A T-STORM DEVELOPING, COVERAGE SHOULD BE LIMITED. ANY
CONVECTION WILL END THIS EVENING AS THE FRONT PUSHES SOUTH OF
THE COAST. THIS WILL ALSO CLEAR OUT ANY STRATUS AND FOG THAT
DEVELOPS OVER THE ISLANDS THROUGH THIS EVENING.
KEY MESSAGE 2...COOLER THURSDAY WITH SCATTERED SHOWERS
DEVELOPING IN THE AFTERNOON, ESPECIALLY ACROSS EASTERN MA.
COOLER TEMPS THU IN THE POST-FRONTAL AIRMASS AS 925 MB TEMPS
DROP TO 12-13C. EXPECT HIGHS IN THE LOW-MID 70S, BUT LIKELY
HOLDING IN THE UPPER 60S ALONG THE EASTERN MA COAST DUE TO A NE
WIND. A MID LEVEL SHORTWAVE ROTATES SOUTHWARD ACROSS THE REGION
WITH AN ACCOMPANYING INCREASE IN MOISTURE. GUIDANCE IS BULLISH
ON SCATTERED SHOWERS DEVELOPING IN THE AFTERNOON, ESPECIALLY
ACROSS EASTERN MA INTO RI AS A COASTAL FRONT SETS UP ACROSS
EASTERN MA ALONG WITH A WEAK WAVE ON THE FRONT WHICH WILL
ENHANCE CONVERGENCE. THE SHOWWERS WILL WIND DOWN THU EVENING AS
THE SHORTWAVE MOVES TO THE EAST FOLLOWED BY SUBSIDENCE.
KEY MESSAGE 3...BROAD CYCLONIC FLOW OVER NORTHEASTERN NORTH
AMERICA WILL SUPPORT UNSETTLED WEATHER IN SOUTHERN NEW ENGLAND
FRIDAY THROUGH THE MIDDLE OF NEXT WEEK
A BROAD UPPER-LEVEL TROUGH ROUGHLY CENTERED OVER EASTERN NORTH
AMERICA/WESTERN NORTH ATLANTIC OCEAN WILL DOMINATE THE WEATHER
PATTERN IN SOUTHERN NEW ENGLAND BETWEEN FRIDAY AND THE MIDDLE OF
NEXT WEEK. SEVERAL PULSES OF SHORT-WAVE ENERGY EMBEDDED IN THIS
BROAD CLYCLONIC FLOW WILL BRING A PRO-LONGED PERIOD OF LARGELY
UNSETTLED WEATHER.
ATHE FIRST PULSE OF SHORT-WAVE ENERGY DIGS THROUGH THE NORTHEAST
LATE FRIDAY INTO SATURDAY BRINGING ROUNDS OF SCATTERED PRECIPITATION
MAILNY TO EASTERN MA AND NH/ME. AS THIS SYSTEM EXITS SOUTHEAST BY
SATURDAY EVENING, WE'LL BE LEFT WITH SOMEWHAT SEASONABLE CONDITIONS
FOR SUNDAY WITH A MIX OF SUN AND CLOUDS.
BEYOND SUNDAY WE BEGIN TO SEE MORE SPREAD IN THE GLOBAL MODEL
GUIDANCE. THE CONSENSUS IS FOR BROAD CYCLONIC FLOW TO PERSIST OVER
THE NORTHEAST WITH ADDITIONAL PRECPITATION CHANCES ON MONDAY AND
TUESDAY. HOW LONG THE CYLONIC UPPER-LEVEL FLOW MEANDERS OVER THE
NORTHEAST IS UNCERTAIN WITH SOME ENSEMBLE SOLUTIONS SUPPORTING MORE
SIGNIFICANT HEIGHT RISES BY WEDENSDAY AND OTHERS SUPPORTING A LATER
DEPARTURE BY LATE NEXT WEEK. TEMPERATURE WILL BE SLIGHTLY BELOW
NORMAL DURING THIS STRETCH WITH DAILY HIGHS/LOWS IN THE UPPER
60S/LOW 70S AND 40S/50S BETWEEN SATURDAY AND WEDNESDAY.
AVIATION /00Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
00Z TAF UPDATE:
TONIGHT...HIGH CONFIDENCE.
IFR STRATUS AND FOG OVER THE ISLANDS CLEARING OUT AND BECOMING
VFR TOWARD 06Z. VFR ELSEWHERE. NW WIND 5-10 KT BECOMING N.
THURSDAY...HIGH CONFIDENCE.
VFR. SCATTERED SHOWERS DEVELOPING IN THE AFTERNOON, ESPECIALLY
EASTERN MA/RI WITH MAINLY VFR CIGS. NW WIND 10-20 KT INTERIOR
AND N-NE AROUND 10 KT NEAR THE EASTERN MA COAST.
THURSDAY NIGHT...HIGH CONFIDENCE.
VFR. LIGHT N-NW WIND.
KBOS...HIGH CONFIDENCE IN TAF.
KBDL...HIGH CONFIDENCE IN TAF. LOW RISK FOR A BRIEF SHOWER AFTER
20Z.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: VFR. CHANCE SHRA.
FRIDAY NIGHT THROUGH SATURDAY: MAINLY VFR, WITH LOCAL MVFR
POSSIBLE. BREEZY. CHANCE SHRA.
SATURDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA.
SUNDAY: VFR. BREEZY.
SUNDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
MONDAY: VFR. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH THURSDAY NIGHT...
WINDS AND SEAS BELOW SCA THRESHOLDS. SW-W WINDS UP TO 20 KT WILL
SHIFT TO NW THEN N TONIGHT. N-NE WIND 5-15 KT THU BECOMING N-NW THU
NIGHT. A FEW SHOWERS OR A T-STORM MAY DEVELOP OVER THE SOUTH COASTAL
WATERS THROUGH EARLY EVENING. SCATTERED SHOWERS DEVELOPING THU
AFTERNOON.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN SHOWERS.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF RAIN SHOWERS.
SATURDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS UP TO 5 FT. CHANCE OF RAIN SHOWERS.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. AREAS OF ROUGH SEAS. SLIGHT CHANCE OF RAIN
SHOWERS.
SUNDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
SUNDAY NIGHT THROUGH MONDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...KJC/RM
AVIATION...KJC/RM
MARINE...KJC/RM
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