339
FXUS61 KBOX 050531
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
131 AM EDT SUN APR 5 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
- A FEW SHOWERS EARLY THIS MORNING, THEN MORE WIDESPREAD
SHOWERS MOVE THROUGH SNE THIS AFTERNOON INTO EARLY EVENING
ASSOCIATED WITH A COLD FRONT.
- CLEARING AND COLDER OVERNIGHT, THEN BLUSTERY MONDAY.
- RAIN/SNOW SHOWERS POSSIBLE MONDAY NIGHT INTO TUESDAY MORNING,
BUT OTHERWISE DRY AND COOL.
- TEMPERATURES INCREASE THROUGH THE SECOND HALF OF NEXT WEEK
AND CONDITIONS REMAIN DRY.
DISCUSSION
KEY MESSAGE 1...A FEW SHOWERS THIS MORNING, THEN MORE
WIDESPREAD SHOWERS MOVE THROUGH SNE THIS AFTERNOON INTO EARLY
EVENING ASSOCIATED WITH A COLD FRONT.
THE BACKDOOR FRONT WHICH MOVED THROUGH SNE SATURDAY WILL RETURN
NORTHWARD AS A WARM FRONT LATER THIS MORNING. MODEST LOW LEVEL
JET COMBINED WITH MARGINAL ELEVATED INSTABILITY WILL BRING A FEW
SHOWERS THIS MORNING AND POSSIBLY A RUMBLE OF THUNDER. LOTS OF
STRATUS AND FOG ALSO EXPECTED THIS MORNING WITH ABUNDANT LOW
LEVEL MOISTURE TRAPPED WITHIN A STRONG SURFACE INVERSION. THE
FOG SHOULD LIFT LATER THIS MORNING AND AFTERNOON AS SW FLOW
DEVELOPS BUT STRATUS MAY LINGER AS LOW LEVEL MOISTURE IS
PERSISTENT. THE SURFACE INVERSION EVENTUALLY ERODES IN THE
AFTERNOON BUT MIXED LAYER IS QUITE SHALLOW. THIS COMBINED WITH
CLOUD COVER AND SHOWERS WILL LIMIT HOW MILD IT GETS, EXPECTING
HIGHS REACHING UPPER 50S AND LOWER 60S, BUT COOLER ALONG THE
SOUTH COAST. IT WILL ALSO BE BREEZY OVER THE CAPE/ISLANDS WITH
LOW LEVEL JET ACROSS THE REGION, EXPECTING GUSTS TO 35 MPH AT
TIMES.
WE EXPECT A PERIOD OF WIDESPREAD RAIN MOVING WEST TO EAST ACROSS SNE
DURING THE AFTERNOON AS A COLD FRONT MOVES THROUGH. THE COLD FRONT
WILL BE ACCOMPANIED BY A DEEP MOISTURE PLUME WITH PWATS 1-1.5" AND
RIGHT ENTRANCE REGION OF UPPER JET SO A PERIOD OF WIDESPREAD
SHOWERS IS LIKELY. MARGINAL ELEVATED INSTABILITY IS ALSO PRESENT
SO CAN'T RULE OUT AN ISOLATED T-STORM. THE BULK OF THE SHOWERS
SHOULD END BY LATE AFTERNOON, BUT WILL LINGER INTO THE EVENING
ACROSS SE MA AND CAPE/ISLANDS WITH LATER TIMING OF COLD FRONT.
KEY MESSAGE 2...CLEARING AND COLDER OVERNIGHT, THEN BLUSTERY MONDAY.
COLD FRONT MOVES ACROSS THE CAPE/ISLANDS IN THE EVENING THEN
OFFSHORE OVERNIGHT. THE FRONTAL PASSAGE WILL BE FOLLOWED BY CLEARING
AND COLDER CONDITIONS AND IT WILL BECOME BLUSTERY OVERNIGHT IN THE
COLD ADVECTION PATTERN. LOWS WILL DROP INTO THE 30S. BLUSTERY BUT
DRY WEATHER CONTINUES MONDAY WITH SOUNDINGS SHOWING A DEEPENING AND
WELL MIXED BOUNDARY LAYER SUPPORTING GUSTS TO 35 MPH AT TIMES.
DIURNAL CU WILL DEVELOP AS UPPER TROUGH AND COOLING TEMPS ALOFT MOVE
THROUGH. HIGHS WILL RANGE FROM THE UPPER 40S TO LOWER 50S WHICH IS
NEAR OR SLIGHTLY BELOW NORMAL FOR EARLY APRIL.
KEY MESSAGE 3...RAIN/SNOW SHOWERS POSSIBLE MONDAY NIGHT INTO
TUESDAY MORNING, BUT OTHERWISE DRY AND COOL.
FOLLOWING SUNDAY'S COLD FRONT, COLDER AND DRIER CONDITIONS TAKE HOLD
AS SURFACE HIGH PRESSURE STARTS TO TAKE HOLD AND AN UPPER LEVEL
TROUGH SETTLES OVERHEAD. A SHORTWAVE MAY MOVE THROUGH THE REGION
MONDAY NIGHT INTO TUESDAY MORNING, WHICH WOULD INTERRUPT THIS BRIEF
DRY PERIOD WITH A MIX OF RAIN AND SNOW SHOWERS. THESE ARE NOT
EXPECTED TO BE VERY IMPACTFUL TO TRAVEL OR ROADS AS TEMPERATURES
REMAIN MOSTLY IN THE 40S AND UPPER 30S. HIGHER ELEVATIONS MAY DIP
BELOW FREEZING, BUT TEMPERATURES THERE WILL ALSO IMPROVE QUICKLY
HEADING INTO TUESDAY MORNING. OUTSIDE OF THE RISK FOR SHOWERS THAT
COULD LINGER THROUGH THE DAY AS THE SHORTWAVE PASSES THROUGH, DRIER
CONDITIONS CAN BE EXPECTED AS DEWPOINTS FALL INTO THE 20S ACROSS THE
REGION (30S OVER THE CAPE AND ISLANDS). TUESDAY NIGHT WILL BE
NOTICEABLY COOLER AS THE TROUGH SITS OVERHEAD AND 925 MB
TEMPERATURES FALL TO -8C TO -5C AFTER BEING JUST AT OR BELOW 0C
MONDAY/MONDAY NIGHT. WINDS REMAIN MOSTLY W AND NW FOR THE START OF
THE WEEK IN THE POST-FRONTAL AIRMASS.
KEY MESSAGE 4...TEMPERATURES INCREASE THROUGH THE SECOND HALF
OF NEXT WEEK AND CONDITIONS REMAIN DRY.
HIGH PRESSURE MOVES INTO THE MID-ATLANTIC REGION DURING THE SECOND
HALF OF THE WEEK THEN SHIFTS MORE OFFSHORE, WHICH WILL AID IN
BRINGING BACK SW FLOW OVER SOUTHERN NEW ENGLAND AND KEEP THE REGION
DRY. TEMPERATURES WILL IMPROVE AS THE WEEK GOES ON AND THE UPPER
LEVEL TROUGH MOVES OFF TO THE EAST. HIGHS WILL LIKELY END UP BACK IN
THE 50S AND 60S. SOME UNCERTAINTY REMAINS, THOUGH, TOWARDS THE END
OF THE WEEK AS THE GEFS HINTS AT ANOTHER BACKDOOR FRONT THAT COULD
LEAD TO COOLER TEMPERATURES, PARTICULARLY ACROSS EASTERN MA AND RI.
IF THAT PLAYS OUT, HIGHS COULD STRUGGLE TO HIT 60F FRIDAY AFTERNOON.
BY COMPARISON, THE OTHER ENSEMBLES DO NOT HAVE THIS FEATURE AND HAVE
HIGHS IN THE MID TO UPPER 60S. WE SHOULD GET MORE CLARITY AS WE GET
CLOSER IN TIME.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE:
TODAY: MODERATE CONFIDENCE.
CONDITIONS LOWERING TO IFR-LIFR IN DEVELOPING STRATUS AND FOG
EARLY THIS MORNING. VSBYS IMPROVE SOME LATER THIS MORNING BUT
LOW CIGS WILL PERSIST THROUGH TODAY. A FEW SHOWERS POSSIBLE THIS
MORNING, THEN MORE WIDESPREAD RAIN AND ISOLATED THUNDER MOVE
THROUGH FROM W TO E THIS AFTERNOON. WIND SHIFT TO S THEN SW
OCCURS 12-15Z FROM S TO N WITH GUSTS TO 25-30 KT DEVELOPING
ALONG THE SOUTH COAST AND CAPE/ISLANDS. AREAS OF LLWS
ASSOCIATED WITH THE LOW LEVEL JET.
TONIGHT: HIGH CONFIDENCE.
LINGERING IFR-MVFR IN SHOWERS OVER SE MA AND THE CAPE/ISLANDS
IN THE EVENING, OTHERWISE BECOMING VFR WITH CLEARING SKIES FROM
W TO E. NW WIND 10-15 KT WITH GUSTS TO 20-25 KT DEVELOPING
OVERNIGHT.
MONDAY...HIGH CONFIDENCE.
VFR. NW GUSTS TO 25-30 KT.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT MODERATE ON
TIMING. EXPECT CONDITIONS TO LOWER TO LIFR IN STRATUS AND FOG
AFTER 09Z WITH VSBYS IMPROVING BY 15Z AFTER WIND SHIFT TO SW.
IFR CIGS LIKELY PERSIST ALTHOUGH MAY SEE SOME IMPROVEMENT TO LOW
END MVFR THIS AFTERNOON. IMPROVING TO VFR WITH WIND SHIFT TO
NW AFTER 00Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT MODERATE ON
TIMING. LOWERING CIGS AND VSBYS TO IFR-LIFR, IMPROVING TO VFR
WITH WIND SHIFT TO NW 23-00Z.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT: VFR. CHANCE SN, SLIGHT CHANCE RA.
TUESDAY: VFR. BREEZY. CHANCE SHRA, CHANCE SHSN.
TUESDAY NIGHT: BREEZY.
WEDNESDAY THROUGH WEDNESDAY NIGHT:
THURSDAY: BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
GUSTY PRE-FRONTAL SW WINDS TODAY WITH GUSTS TO 25-35 KT AS LLJ WILL
BE OVER THE WATERS. WILL CONTINUE SCA ALTHOUGH A FEW NEAR GALE FORCE
GUSTS POSSIBLE. THE LLJ MOVES OFFSHORE TONIGHT BUT EXPECT POST-
FRONTAL W GUSTS TO 25 KT LATE TONIGHT AND MONDAY. AREAS OF FOG THIS
MORNING WITH POOR VSBYS, THEN SHOWERS MID AFTERNOON INTO THIS
EVENING. AN ISOLATED T-STORM IS POSSIBLE.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
TUESDAY: WINDS LESS THAN 25 KT. CHANCE OF RAIN SHOWERS.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY
APPROACHING 5 FT.
THURSDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
ANZ230>237-250-251-254>256.
DISCUSSION...KJC/HRENCECIN
AVIATION...KJC
MARINE...KJC
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