570
FXUS61 KBOX 051139
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
739 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.
- COULD SEE A FEW RAIN/SNOW SHOWERS MONDAY NIGHT INTO
TUESDAYMORNING, BUT OTHERWISE EXPECTING COOLER TEMPERATURES
AND DRY WEATHER FOR A GOOD PORTION OF NEXT WEEK.
- SECOND HALF OF NEXT WEEK LOOKS MAINLY DRY WITH TEMPERATURES ON
THE RISE.
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...COULD SEE A FEW RAIN/SNOW SHOWERS MONDAY NIGHT
INTO TUESDAY MORNING, BUT OTHERWISE EXPECTING COOLER
TEMPERATURES AND DRY WEATHER FOR A GOOD PORTION OF NEXT WEEK.
EXPECTING AN UPPER-LEVEL TROUGH TO PUSH ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND EARLY NEXT WEEK, LEADING TO MOSTLY DRY
WEATHER AND COOLER TEMPERATURES. ENSEMBLE GUIDANCE IS INDICATING
850MB TEMPERATURES COULD GET TO BELOW -5C AND 500MB
TEMPERATURES BELOW - 30C TUESDAY AS A SHORTWAVE MOVES THROUGH,
WHICH WOULD SUPPORT SOME LIGHT SNOW SHOWERS DEVELOPING AND
MIXING IN WITH RAIN SHOWERS, ESPECIALLY OVER THE HIGHER
ELEVATION AREAS, THOUGH WE'RE NOT EXPECTING ANY ROAD OR TRAVEL
IMPACTS. SURFACE TEMPERATURES WILL LIKELY HOVER NEAR OR POSSIBLY
JUST BELOW FREEZING MONDAY NIGHT INTO TUESDAY MORNING, BUT
THEY'RE EXPECTED TO MAKE A FAST RECOVERY LATER TUESDAY
MORNING... INTO THE MID 40S. OTHERWISE, DRY WEATHER WITH HIGH
TEMPS MAINLY IN THE MIDDLE 40S TO THE LOWER 50S AND OVERNIGHT
TEMPERATURES RANGING FROM THE MID 20S TO MID 30S THROUGH
WEDNESDAY NIGHT.
KEY MESSAGE 4...SECOND HALF OF NEXT WEEK LOOKS MAINLY DRY WITH
TEMPERATURES ON THE RISE.
A LARGE HIGH PRESSURE SYSTEM MOVES INTO THE MID-ATLANTIC REGION
BY THE SECOND HALF OF NEXT WEEK, BRINGING PREDOMINANTLY
SOUTHWESTERLY FLOW AND DRY CONDITIONS BACK TO SOUTHERN NEW
ENGLAND. THE WARMER AIRMASS ADVECTING INTO THE REGION WILL ALLOW
TEMPERATURES TO RECOVER BACK INTO THE 50S AND 60S BY THE END OF
THE WEEK.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z 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 SHRA, CHANCE SHSN.
TUESDAY: 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. SLIGHT CHANCE OF RAIN SHOWERS.
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>234-236-251.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR ANZ254>256.
DISCUSSION...KJC/MCMINN
AVIATION...MCMINN/FT
MARINE...KJC
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