207
FXUS61 KBOX 041837
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
237 PM EDT MON MAY 4 2026
WHAT HAS CHANGED
WIND ADVISORIES ISSUED FOR TUESDAY AFTERNOON AND EVENING ACROSS
EASTERN MASSACHUSETTS AND RHODE ISLAND. GALE WARNINGS ALSO
ISSUED TUESDAY AFTERNOON AND EVENING FOR ALL NEARSHORE WATERS.
KEY MESSAGES
- WINDY TUE WITH UNSEASONABLY WARM TEMPS AWAY FROM THE SOUTH
COAST. WIND ADVISORY FOR THE BOS-PVD CORRIDOR. DRY OUTSIDE
THE LOW RISK FOR A LATE TUE SPOT SHOWER/T-STORMM IN NW MA.
- PERIODS OF SHOWERS AND T-STORMS ARRIVE FROM WEST TO EAST WED AND
SHOWERS MAY PERSIST INTO THU FOR PARTS OF THE REGION.
- TURNING SHARPLY COOLER LATE IN THE WEEK AND INTO THE WEEKEND
WITH A FEW STRAY SHOWERS POSSIBLE BUT MAINLY DRY.
DISCUSSION
KEY MESSAGE 1...WINDY TUE WITH UNSEASONABLY WARM TEMPS AWAY
FROM THE SOUTH COAST. WIND ADVISORY FOR THE BOS-PVD CORRIDOR.
DRY OUTSIDE THE LOW RISK FOR A LATE TUE SPOT SHOWER/T-STORM
IN NW MA.
A SLOW MOVING COLD FRONT WILL APPROACH THE EASTERN GREAT LAKES AS
HIGH PRESSURE SLIDES FURTHER EAST IN THE ATLANTIC ON TUE. THIS WILL
RESULT IN A STRONG SOUTHWEST FLOW OF UNSEASONABLY WARM TEMPERATURES.
925T ON THE ORDER OF +18C/+19C NORTHWEST OF I-95 SHOULD YIELD HIGH
TEMPS IN THE UPPER 70S TO THE LOWER 80S. STRONG SOUTHWEST WILL YIELD
MUCH COOLER TEMPS TOWARDS THE SOUTH COAST...HOLDING HIGHS IN THE 60S
TO THE LOWER 70S. IN FACT...NANTUCKET MAY NOT BREAK 60!
IT WILL ALSO BE QUITE WINDY ON TUE WITH A STRONG SOUTHWEST LLJ. THE
MODEL GUIDANCE IS INDICATING THIS 925 MB ON THE ORDER OF 50-60+
KNOTS. THE RESULT WILL BE SOUTHWEST WIND GUSTS OF 30 TO 45 MPH
DEVELOPING BY MID AFTERNOON. IN FACT...A SWATH OF 40-50 MPH WIND
GUSTS SEEM REASONABLE IN THE VICINITY OF THE I-95 CORRIDOR. THIS IS
ON THE NORTHWEST EDGE OF THE STRONGEST JET AND ALSO WHERE TEMPS GET
WARM ENOUGH FOR SUFFICIENT MIXING. THEREFORE...WE HAVE HOISTED A
WIND ADVISORY ACROSS EASTERN MA/RI AND ONTO THE UPPER CAPE FROM NOON
TO 10 PM ON TUE. THE STRONGEST OF THOSE WINDS ARE MOST LIKELY IN THE
3 TO 7 PM WINDOW.
LASTLY...THERE IS A LOW RISK FOR A LATE AFTERNOON-EVENING SHOWER/T-
STORM OR TWO ACROSS NORTHWEST MA WITH SOME MARGINAL INSTABILITY.
HOWEVER...THE MAIN THREAT FOR THIS WILL BE WELL TO OUR NORTHWEST
GIVEN THE LACK OF ANY REAL SYNOPTIC SCALE FORCING.
WHILE SOUTHWEST WINDS WILL DIMINISH SOME TUE NIGHT WITH THE LOSS OF
DIURNAL HEATING...THE SOUTHWEST LLJ WILL MAINTAIN A GUSTY SOUTHWEST
BREEZE WELL INTO THE OVERNIGHT HOURS. THIS WILL RESULT IN AN
UNSEASONABLY MILD NIGHT. OVERNIGHT LOW TEMPS WILL ONLY DROP INTO THE
MIDDLE TO UPPER 50S IN MOST LOCATIONS...EXCEPT JUST A FEW DEGREES
COOLER NEAR THE SOUTH COAST.
KEY MESSAGE 2...PERIODS OF SHOWERS AND T-STORMS ARRIVE FROM
WEST TO EAST WED AND SHOWERS MAY PERSIST INTO THU FOR PARTS OF
THE REGION.
A COLD FRONT APPROACHES WESTERN MA/CT WEDNESDAY EVENING/NIGHT AND
CROSSES THE REGION FULLY BY MID MORNING ON THURSDAY. THIS WILL BE
THE WETTEST STRETCH OF THE WEEK AS A PLUME OF MOISTURE AND EVEN SOME
INSTABILITY ADVECTS NORTH INTO THE REGION DURING THE DAY ON
WEDNESDAY IN THE WARM SECTOR. WARM IS RELATIVE, THOUGH, AS HIGH
TEMPERATURES WILL ACTUALLY BE QUITE A BIT COOLER THAN TUESDAY IN THE
UPPER 60S AND LOW 70S. THIS, WITH DEWPOINTS IN THE MID TO UPPER 50S
MAY LEAD TO A FEW HUNDRED J/KG OF ELEVATED CAPE, ENOUGH FOR SOME
EMBEDDED THUNDER BUT NOT SUPPORTIVE OF ANY SEVERE WEATHER. AS THE
PARENT LOW EXITS TO OUR NORTHEAST OVERNIGHT A SECONDARY LOW LOOKS TO
FORM SOMEWHERE IN THE VICINITY OF OUR SOUTHERN WATERS WHICH MAY LEAD
TO A RESURGENCE OF MODERATE TO HEAVY RAIN DURING THE FIRST PART OF
THURSDAY. AT THIS TIME, THOUGH, IT IS BORDERLINE, WITH SOME GUIDANCE
INDICATING IT FORMING TOO LATE/SOUTH TO TRULY IMPACT SNE. THE BEST
CHANCE FOR THURSDAY MODERATE RAIN, THOUGH, WOULD BE THE SOUTHERN
TIER OF THE REGION. ENSEMBLE GUIDANCE INDICATES THE BEST CHANCE (50-
70%) OF AOA 0.1" OF RAIN AFTER 8AM THURSDAY TO BE ON CAPE COD AND
THE ISLANDS, DIMINISHING TO THE NORTHWEST WITH <20% CHANCE IN
WESTERN MA. WHAT'S MORE CERTAIN IS THAT TEMPERATURES WILL BE COOLER
ON THURSDAY IN THE POST FRONTAL AIRMASS, IN THE LOW TO MID 60S. THIS
ACTUALLY PUTS US RIGHT AROUND NORMAL FOR EARLY MAY.
KEY MESSAGE 3...TURNING SHARPLY COOLER LATE IN THE WEEK AND
INTO THE WEEKEND WITH A FEW STRAY SHOWERS POSSIBLE BUT MAINLY
DRY.
BEYOND THURSDAY IS WHEN WE GET INTO THE SLIGHTLY BELOW NORMAL
STRETCH OF TEMPERATURES WHICH PERSISTS THROUGH AT LEAST SATURDAY.
HIGH ELEVATIONS LIKELY DON'T MAKE IT OUT OF THE 50S. THIS, AS A
BROAD EAST COAST TROUGH REMAINS OVERHEAD WITH BELOW NORMAL HEIGHTS
TO START THE WEEKEND BEFORE THINGS BEGIN MODERATING TOWARD NEXT
WEEK. THIS TROUGH WITH SOME WEAK DISTURBANCES ROUNDING IT MAY LEAD
TO A SOME SCATTERED SHOWERS, ESPECIALLY OVER INTERIOR SNE BUT AT THE
MOMENT THE FORECAST LEANS DRIER RATHER THAN WETTER; IN OTHER WORDS,
SOME SHOWERS BUT NOT A WASHOUT. THAT BEING SAID, SOME GUIDANCE (THE
GFS IN PARTICULAR) HINTS AT A MORE ROBUST SHORTWAVE MOVING THROUGH
WHICH COULD THROUGH A WRENCH IN THAT DRIER THAN WETTER FORECAST FOR
SATURDAY. TOO SOON TO NAIL DOWN THESE KIND OF DETAILS, STAY
TUNED.
AVIATION /18Z MONDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE...
VFR CONDITIONS CONTINUE THROUGH TUESDAY. SOUTHWEST WIND GUSTS OF
25 TO 35 KNOTS THIS AFTERNOON WITH A FEW GUSTS NEAR 40 KNOTS WILL
GRADUALLY DIMINISH THIS EVENING. HOWEVER...SUSTAINED SOUTHWEST
WINDS OF 5 TO 15 KNOTS WITH A FEW 20+ KNOT GUSTS AT TIMES WILL
CONTINUE OVERNIGHT. SW WIND GUSTS WILL STRENGTHEN AGAIN LATER
TUESDAY MORNING AND ESPECIALLY TUESDAY AFTERNOON INTO THE FIRST
HALF OF TUESDAY EVENING. SW WIND GUSTS WILL INCREASE ON THE
ORDER OF 30-40 KNOTS AND A FEW GUSTS MAY REACH 40-45 KNOTS
BRIEFLY ESPECIALLY NEAR THE I-95 CORRIDOR.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. CHANCE
SHRA.
WEDNESDAY NIGHT: MAINLY VFR, WITH AREAS IFR POSSIBLE. BREEZY.
CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY: VFR. CHANCE SHRA.
THURSDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
FRIDAY: VFR. BREEZY.
FRIDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE.
SATURDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. BREEZY. 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.
NEAR SHORE SW GALE FORCE WIND GUSTS WILL DIMINISH EARLY THIS
EVENING. HOWEVER...ANOTHER ROUND OF NEAR SHORE SW GALE FORCE WIND
GUSTS IS ON TAP FOR TUESDAY AFTERNOON AND EVENING. THEREFORE...WE
HAVE ISSUED ANOTHER SET OF NEARSHORE GALE HEADLINES WITH STRONG
SMALL CRAFT HEADLINES PERSISTING ACROSS THE OUTER-WATERS.
OUTLOOK /WEDNESDAY THROUGH SATURDAY/...
WEDNESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS UP TO 5 FT. CHANCE OF RAIN SHOWERS.
WEDNESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. LOCAL ROUGH SEAS. RAIN SHOWERS, SLIGHT
CHANCE OF THUNDERSTORMS.
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF RAIN SHOWERS.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. CHANCE
OF RAIN SHOWERS.
FRIDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
SATURDAY: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. SLIGHT
CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...WIND ADVISORY FROM NOON TO 10 PM EDT TUESDAY FOR MAZ005>007-
013>022.
RI...WIND ADVISORY FROM NOON TO 10 PM EDT TUESDAY FOR RIZ002>007.
MARINE...GALE WARNING FROM 11 AM TO 11 PM EDT TUESDAY FOR ANZ230>237-
251.
GALE WARNING UNTIL 7 PM EDT THIS EVENING FOR ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR ANZ250-
254>256.
DISCUSSION...FRANK/BW
AVIATION...FRANK
MARINE...FRANK/BW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page