367
FXUS61 KBOX 131909
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
309 PM EDT SUN APR 13 2025
SYNOPSIS
THE PERSISTENT STORM WHICH HAS IMPACTED THE REGION THIS WEEKEND
WILL FINALLY PULLS AWAY TONIGHT WITH HIGH PRESSURE BRINGING DRY
AND MUCH MILDER CONDITIONS MONDAY. CONTINUED MILD TUESDAY BUT A
FRONTAL SYSTEM WILL BRING SCATTERED SHOWERS LATE MONDAY NIGHT
INTO TUESDAY. DRIER, COOLER, AND WINDIER FOR WEDNESDAY, THEN
SLIGHTLY WARMER AND MORE SEASONABLE THURSDAY. DRY AND WARMER FOR
FRIDAY BEFORE THE CHANCE FOR SOME SCATTERED SHOWERS RETURNS
GOING INTO FRIDAY NIGHT/SATURDAY MORNING.
NEAR TERM /UNTIL 6 AM MONDAY MORNING/
KEY MESSAGES:
* RAIN EXITS CAPE/ISLANDS THIS EVENING, OTHERWISE GRADUAL CLEARING
FROM W TO E TONIGHT
MODERATE TO OCCASIONAL HEAVY RAIN ROTATING WESTWARD ACROSS CAPE COD
AND INTO SE MA THIS AFTERNOON ON THE WESTERN PERIPHERY OF THE MID
LEVEL LOW. RAIN WILL CONTINUE TO IMPACT MUCH OF EASTERN MA INTO RI
AT TIMES THROUGH THE AFTERNOON. BY THIS EVENING, AREA OF RAIN WILL
BE CONFINED TO SE COASTAL MA AND CAPE COD AND WILL GRADUALLY EXIT
THROUGH MIDNIGHT AS THE MID LEVEL LOW MOVES EASTWARD. OTHERWISE, WE
EXPECT CLEARING SKIES FROM W TO E AS RIDGING ALOFT BUILDS IN FROM
THE WEST WITH GOOD DRYING IN THE COLUMN. EXCEPTION WILL BE OVER THE
CAPE/ISLANDS WHICH MAY TAKE UNTIL DAYBREAK TO CLEAR OUT. DESPITE
CLEARING SKIES, THERE WILL BE ENOUGH GRADIENT TO KEEP A STEADY WIND
GOING TO LIMIT RADIATIONAL COOLING. WINDS WILL REMAIN GUSTY
CAPE/ISLANDS WITH GUSTS 20-30 MPH, AND 5-15 MPH FURTHER INLAND. AS A
RESULT, EXPECT LOWS TO HOLD IN THE MID-UPPER 30S, WITH LOWER 30S
POSSIBLE IN NW MA. LOW RISK FOR PATCHY FOG IN WESTERN MA BUT WIND
MIGHT BE A LIMITING FACTOR.
SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/
KEY MESSAGES:
* SUNNY AND TURNING MILDER MONDAY WITH ABOVE NORMAL TEMPS. POSSIBLE
SEABREEZE FOR BOTH COASTS
* SCATTERED SHOWERS DEVELOPING MON NIGHT
MONDAY...
RIDGING AT THE SURFACE AND ALOFT WILL PROVIDE ABUNDANT SUNSHINE AND
MILD TEMPS. HIGH CLOUDS WILL BE STREAMING INTO THE REGION LATER IN
THE AFTERNOON. 925 MB TEMPS 8-10C AND INITIAL NW FLOW WILL SUPPORT
HIGHS INTO THE MID-UPPER 60S. GRADIENT RELAXES IN THE AFTERNOON
WHICH MAY ALLOW FOR LOCALIZED COOLING SEA-BREEZES ALONG THE COAST.
MONDAY NIGHT...
FAIRLY ROBUST SHORTWAVE MOVES INTO THE EASTERN GT LAKES OVERNIGHT AS
COLD FRONT APPROACHES SNE FROM THE WEST. DECENT MOISTURE ADVECTION
AHEAD OF THE TROUGH WITH PWATS INCREASING TO AROUND 1 INCH.
DIFFLUENT FLOW ALOFT WILL PROVIDE ENOUGH FORCING FOR SCATTERED
SHOWERS TO DEVELOP DURING THE LATE EVENING AND OVERNIGHT ALTHOUGH
THE COLUMN DOESN'T FULLY SATURATE SO NOT EXPECTING WIDESPREAD
SHOWERS. LOWS WILL BE IN THE 40S.
LONG TERM /TUESDAY THROUGH SUNDAY/
KEY MESSAGES:
* SCATTERED SHOWERS MONDAY NIGHT INTO TUESDAY POSSIBLE
* DRY, BLUSTERY, AND COOLER WEDNESDAY; SLIGHTLY WARMER THURSDAY
* SHOWERS POSSIBLE FRIDAY NIGHT/SATURDAY MORNING
* WARMER ON TUESDAY WITH SCATTERED SHOWERS
* COOLER/WINDY CONDITIONS ON WEDNESDAY WILL BE FOLLOWED BY AN UPTICK
IN TEMPERATURES EACH DAY THROUGH SATURDAY
* NEXT OPPORTUNITY FOR SUBSTANTIAL PRECIPITATION WILL BE SATURDAY
TUESDAY
LOW PRESSURE OVER THE NORTHEAST WILL SUPPORT PERIODS OF SCATTERED
SHOWERS DURING THE DAY ON TUESDAY. MID-LEVEL LAPSE RATES (500-700
HPA) LOOK TO BE FAIRLY STEEP AS WELL, SO CAN'T RULE OUT A RUMBLE OF
THUNDER WITH SOME SMALL GRAUPEL, ESPECIALLY FOR LOCATIONS WEST OF
WORCESTER WHERE LAPSE RATES LOOK TO BE STEEPEST. DESPITE THE
SHOWERS, TEMPERATURES WILL BE MILDER THAN THEY WERE THIS PAST
WEEKEND WITH SEASONABLE HIGH TEMPERATURES IN THE LOW TO MID 60S.
COOLER ON THE CAPE IN THE MID 50S.
TUESDAY NIGHT THROUGH FRIDAY
A COLD FRONT PUSHES THROUGH THE REGION TUESDAY NIGHT INTO WEDNESDAY.
THIS WILL BE ACCOMPANIED BY DEEP NORTHWEST FLOW AND A DRIER AIR MASS
THAT WILL LIMIT RAIN CHANCES FOR THE REST OF THE WEEK. EXPECT GUSTY
NORTHWEST WINDS UP TO 30 MPH ON WEDNESDAY AFTERNOON AS DIURNAL
MIXING WILL ALLOW STRONGER WINDS IN THE 925-850 HPA LAYER TO MIX
DOWN TO THE SURFACE. TEMPERATURES WILL BE MUCH COOLER ON WEDNESDAY
COMPARED TO TUESDAY WITH HIGH TEMPS IN THE UPPER 40S TO LOW 50S.
BY THURSDAY, THERE LOOKS TO BE LITTLE TO MODIFICATIONS TO THE AIR
MASS IN PLACE, THUS WE CAN EXPECT A SIMILAR DAY TO WEDNESDAY.
HOWEVER, A DRIER COLUMN AND LESS CLOUD COVER SHOULD SUPPORT
TEMPERATURES A FEW DEGREES WARMER IN THE LOW TO MID 50S. ATMOSPHERE
REMAINS WELL MIXED, SO ANOTHER ROUND OF 25-30 MPH NORTHWEST WIND
GUSTS WILL BE IN THE CARDS FOR THURSDAY AFTERNOON.
A MID-LEVEL RIDGE AXIS BUILDS IN FROM THE WEST BY FRIDAY. THIS WILL
CONTINUE TO ALLOW TEMPERATURES TO RISE INTO THE UPPER 50S TO LOW 60S
BY FRIDAY AFTERNOON. AS HIGH PRESSURE BUILDS IN FROM THE WEST, THE
PRESSURE GRADIENT RELAXES WHICH WILL BRING AN END TO THE GUSTY
NORTHWEST WINDS THAT ARE FORECAST FOR WEDNESDAY/THURSDAY. FRIDAY MAY
VERY WELL BE THE PICK OF THE WEEK FOR PLEASANT SPRING WEATHER. THERE
IS A LOW RISK FOR SOME SHOWERS/INCREASING CLOUDINESS BY MID-
AFTERNOON FRIDAY AS WARM ADVECTION ENSUES WITH SOUTHERLY RETURN
FLOW.
NEXT WEEKEND
THERE IS GOOD AGREEMENT AMONG THE GLOBAL MODEL SUITE FOR A WARM
SECTOR AIR MASS TO SETTLE OVER SOUTHERN NEW ENGLAND ON SATURDAY.
WITH 925 HPA TEMPS POSSIBLY AS HIGH AS 20C, HIGH TEMPS IN THE UPPER
60S- LOW 70S WILL BE IN THE CARDS FOR SATURDAY AFTERNOON. ALTHOUGH
THE AIR MASS WILL BE WARM, WARM ADVECTION AND INCREASED MOISTURE
TRANSPORT WILL SUPPORT A CLOUDY AND LIKELY RAINY START TO THE
WEEKEND.
A COLD FRONT LOOKS TO USER OUT THE WARMER AIR MASS ON SUNDAY WHICH
MAY FEATURE POST-FRONTAL CONDITIONS WITH COOLER TEMPERATURES AND
GUSTY NORTHWEST WINDS. STAY TUNED FOR FURTHER DETAILS.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THROUGH 00Z:
MVFR-IFR CONDITIONS IN RAIN PERSISTING ACROSS EASTERN MA.
ELSEWHERE, MVFR CIGS IMPROVING TO VFR IN THE CT VALLEY. N-NW
GUSTS 25-30 KT SE COASTAL MA AND CAPE/ISLANDS. GUSTS TO 20 KT
ELSEWHERE.
TONIGHT: HIGH CONFIDENCE IN TRENDS, MODERATE ON TIMING.
RAIN EXITS CAPE/ISLANDS THIS EVENING WITH IFR CIGS HERE
IMPROVING TO MVFR AFTER 03Z AND TO VFR AFTER 09Z. ELSEWHERE,
TRENDING TO VFR THIS EVENING WITH CLEARING FROM W TO E. NW
GUSTS TO 25 KT CAPE/ISLANDS, 5-15 KT ELSEWHERE.
MONDAY: HIGH CONFIDENCE.
VFR. NW WIND 8-15 KT IN THE MORNING, DIMINISHING AND BECOMING
SW IN THE AFTERNOON. LOCAL SEA-BREEZES DEVELOPING AFTER 18Z.
MONDAY NIGHT: MODERATE CONFIDENCE.
VFR TRENDING TO MVFR OVERNIGHT WITH SCATTERED SHOWERS
DEVELOPING.
KBOS TAF...HIGH CONFIDENCE IN TRENDS, MODERATE ON TIMING.
KBDL TAF...HIGH CONFIDENCE.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: MAINLY MVFR, WITH LOCAL IFR POSSIBLE. BREEZY. CHANCE
RA.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL
MVFR POSSIBLE. BREEZY.
THURSDAY: VFR. BREEZY.
THURSDAY NIGHT: VFR.
FRIDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH MONDAY NIGHT: HIGH CONFIDENCE.
MAY SEE SOME LOCALIZED MARGINAL GALE GUSTS TO 35 KT OVER WATERS EAST
OF CAPE COD THROUGH EARLY EVENING. OTHERWISE N-NW GUSTS 25-30 KT
OVER EASTERN MA WATERS TONIGHT WILL DIMINISH MON AND BECOME S-SW IN
THE AFTERNOON. S-SW WIND 10-15 KT MON NIGHT. ROUGH SEAS OVER EASTERN
MA WATERS WILL SLOWLY SUBSIDE OVERNIGHT INTO MONDAY.
OUTLOOK /TUESDAY THROUGH FRIDAY/...
TUESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN.
TUESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. LOCAL ROUGH SEAS.
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 25 KT. AREAS OF ROUGH SEAS.
WEDNESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. LOCAL ROUGH SEAS.
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
FRIDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ231-232.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ233-
234.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR ANZ250-254.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT MONDAY FOR ANZ251.
SMALL CRAFT ADVISORY UNTIL 2 PM EDT MONDAY FOR ANZ255.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ256.
SYNOPSIS...KJC/RM
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...RM
AVIATION...KJC/RM
MARINE...KJC/RM
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