272
FXUS61 KBOX 080031
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
831 PM EDT WED MAY 7 2025
SYNOPSIS
AN UPPER LEVEL LOW MOVES EASTWARD THROUGH INTERIOR NORTHERN NEW
ENGLAND TONIGHT. DRIER WEATHER THEN BRIEFLY DEVELOPS ON
THURSDAY. ANOTHER WINDSWEPT RAIN EVENT WITH BELOW-NORMAL
TEMPERATURES DEVELOPS FOR THURSDAY NIGHT INTO FRIDAY NIGHT, WITH
MORE HIT OR MISS SHOWERS POSSIBLE INTO SATURDAY. RISES TO AT OR
OVER BANKFULL AND POCKETS OF URBAN AND POOR DRAINAGE STREET
FLOODING COULD AGAIN DEVELOP FOR THE INTERIOR. CLEARING OUT AND
TRENDING DRIER ON SUNDAY WITH A STEADY WARMING TREND INTO EARLY
NEXT WEEK.
NEAR TERM /THROUGH THURSDAY/
KEY MESSAGES:
* WIDELY SCATTERED SHOWERS IN NORTHEAST MA END BY SUNDOWN.
* CLEARING TONIGHT. OUTSIDE CHANCE AT PATCHY FOG.
UPPER LEVEL LOW IN INTERIOR NORTHERN NEW ENGLAND IS PRODUCING
WIDELY SCATTERED SHOWERS INTO THE NORTH SHORE/GREATER BOSTON
AREA AND INTO FAR NORTHERN WORCESTER COUNTY; SPC MESOANALYSIS
CAPE VALUES ARE SLIGHTLY HIGHER IN NH AND ME AT AROUND 500
J/KG, SO ALREADY PRETTY WEAK INSTABILITY ACROSS SOUTHERN NEW
ENGLAND. ALTHOUGH A FEW LIGHTNING STRIKES ARE BEING OBSERVED IN
NH/ME, ACTIVITY LOOKS TOO SHALLOW AND CONVECTIVE INSTABILITY TOO
WEAK TO PRODUCE ANY THUNDERSTORMS WITH MAINLY SCATTERED HIT OR
MISS SHOWERS ACROSS EASTERN/NORTHEAST MA THROUGH SUNDOWN.
WEAK SHORTWAVE RIDGING ALOFT THEN BUILDS INTO SOUTHERN NEW
ENGLAND FOR TONIGHT, WITH A WEAK SURFACE TROUGH LEFT BEHIND BY
THE UPPER LOW DRAPED NEAR OR JUST WEST OF THE CAPE COD CANAL.
WEAK NORTHWEST FLOW SHOULD BE PREVALENT FOR MOST AREAS TO I-95
AS WE MOVE INTO THE EVENING AND OVERNIGHT. WE HAD QUITE A BIT OF
PATCHY FOG LAST NIGHT, AND THAT STILL SEEMS POSSIBLE GIVEN THE
DAMP GROUND FROM THE LAST COUPLE DAYS, BUT WITH THE NORTHERLY
FLOW AND SOME HEATING THAT TOOK PLACE TODAY, IT ADDS MORE
UNCERTAINTY IF WE CAN SEE RE-DEVELOPMENT OF PATCHY FOG. LEFT OUT
OF THE GRIDS FOR NOW. A BETTER CHANCE AT STRATUS AND FOG/MIST
TONIGHT IS FOR THE CAPE AND ISLANDS GIVEN LEFTOVER MARITIME SW
FLOW. LOWS TONIGHT SHOULD BE A LITTLE BIT COOLER THAN PRIOR
NIGHTS, WITH READINGS IN THE MID 40S TO LOW 50S.
SHORT TERM /THURSDAY NIGHT/
KEY MESSAGES:
* DRY MOST OF THURSDAY, THOUGH RAIN INCREASES THURSDAY
AFTERNOON AND ESPECIALLY THURSDAY NIGHT INTO WESTERN NEW
ENGLAND.
* MORE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE
THURSDAY
THURSDAY:
WE GET INTO WEAK SURFACE RIDGING DURING THE FIRST PART OF
THURSDAY, OFFERING PARTLY TO MOSTLY SUNNY CONDITIONS AND WEAK
NORTHERLY WINDS. MOVING INTO THE AFTERNOON, A UPPER TROUGH WITH
POSITIVE TILT FROM ONTARIO CONTINUES TO DIG INTO SOUTHERN NY
BEFORE CLOSING OFF. THIS WILL INDUCE AN ORGANIZING AREA OF LOW
PRESSURE NEAR OR SOUTH OF THE LOWER HUDSON VALLEY IN NY, AND
LEAD TO AN ENHANCED ENE FLOW WITH A INVERTED TROUGH FROM SFC TO
700 MB WHICH EXTENDS INTO WESTERN CT AND THE BERKSHIRES.
INCREASED MOISTURE BRINGS ANOTHER ROUND OF INITIALLY LIGHT RAIN
FOR THE LATTER PORTION OF THIS PERIOD FOR WESTERN MA AND CT,
BUT THIS WILL HERALD THE BEGINNING OF ANOTHER RATHER WET WEATHER
PATTERN AS WE MOVE INTO THURSDAY NIGHT. SHOULD SEE HIGHS IN THE
INTERIOR IN THE LOWER 70S, BUT COOLER READINGS IN THE MID 60S
BY EARLY AFTERNOON ONCE ONSHORE FLOW STARTS TO DEVELOP.
THURSDAY NIGHT:
CARRYING OVER FROM THE AFTERNOON, THE START OF ANOTHER WET
WEATHER PATTERN THEN CONTINUES IN EARNEST WITH STEADY LIGHT TO
MODERATE RAIN BREAKING OUT INTO WESTERN AND PERHAPS INTO CENTRAL
MA AND INTO MUCH OF CT. THIS WILL BE ENHANCED BY PRETTY STOUT
UPSLOPE FLOW AND FOCUSED ALONG THE 925-700 MB INVERTED TROUGH
AXIS. THESE AREAS HAVE SEEN QUITE A BIT OF RAIN IN RECENT DAYS,
LOCALLY UP TO 4 INCHES IN SOME LOCATIONS, AND HYDRO CONCERNS
INCLUDING CONTINUED OR EXACERBATED RISES ON RIVERS AND STREAMS
AND MINOR STREET FLOODING COULD ENSUE STARTING THURSDAY NIGHT.
SEE THE ADDED HYDROLOGY SECTION FOR MORE DETAILS. FORECAST
RAINFALL FOR THURSDAY NIGHT RANGES FROM A HALF TO THREE QUARTERS
OF AN INCH (WITH LOCALLY HIGHER AMTS POSSIBLE) IN WESTERN MA/CT.
ALTHOUGH IT WILL BE OVERCAST AND BREEZY FOR THE VAST MAJORITY OF
EASTERN MA AND RI, LOOKS GENERALLY DRY. LOWS IN THE 40S TO NEAR
50.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
KEY POINTS:
* SOAKING, WINDSWEPT RAINS FRIDAY INTO FRIDAY NIGHT WITH BELOW
NORMAL TEMPERATURES.
* MORE HIT OR MISS TYPE SHOWERS FOR SATURDAY, BUT TRENDING DRIER
LATE IN THE DAY.
* POSSIBLE HYDRO CONCERNS FOR FRIDAY INTO SATURDAY.
* DRYING WITH A WARMING TREND SUNDAY INTO MIDWEEK.
DETAILS:
FRIDAY INTO SATURDAY:
ANOTHER DREARY, COOL AND OVERCAST FRIDAY INTO FRIDAY NIGHT,
WITH RAINS OVER THE INTERIOR HIGHER TERRAIN EXPANDING EASTWARD.
ALTHOUGH TEMPERATURES LOOK TO BE QUITE A BIT BELOW NORMAL, RATHER
MOIST AIRMASS WITH ELEVATED PRECIPITABLE WATER VALUES AROUND
1.3 TO 1.5 INCHES WILL CONTINUE TO BE FORCED UPSLOPE IN EASTERLY
FLOW, WITH HIGHEST RAIN TOTALS FOCUSED INTO WESTERN NEW ENGLAND.
EASTERN NEW ENGLAND SEES THE PERIOD OF WETTEST CONDITIONS
FOCUSED INTO FRIDAY AFTERNOON TO THE EVENING AS LOW PRESSURE
SLOWLY TRUDGES NORTHEASTWARD INTO NORTHEAST MA AND THE GULF OF
MAINE. HYDROLOGIC CONCERNS SHOULD CONTINUE TO LINGER INTO FRIDAY.
STILL GENERALLY UNSETTLED INTO SATURDAY, ALTHOUGH THE RAIN
COVERAGE SHOULD TURN MORE SHOWERY AS THE POTENT UPPER LOW TREKS
THROUGH SOUTHERN NEW ENGLAND. WHILE SATURDAY MIGHT NOT PROVE TO
BE A TRUE WASHOUT, THERE STILL SHOULD BE SOME SHOWERS TO DODGE.
SUNDAY INTO MIDWEEK:
ENSEMBLES CONTINUE TO POINT TO AT LEAST AN EXTENDED SPELL OF
DRIER WEATHER WITH A GRADUAL WARMING TREND AS WE MOVE INTO
MIDWEEK.
AVIATION /00Z THURSDAY THROUGH MONDAY/
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
00Z TAF UPDATE:
TONIGHT: HIGH CONFIDENCE OVERALL, THOUGH MODERATE ON FOG FOR
PARTS OF INTERIOR AND CAPE/ISLANDS.
VFR FOR MUCH OF THE INTERIOR AND COASTAL PLAIN TONIGHT. THERE'S
A CHANCE AT SOME PATCHY FOG (INDICATED BY TEMPOS 2-5 SM VIS
BR). IT IS NOT CERTAIN IF FOG CAN DEVELOP AS DRIER NW WINDS
DEVELOP WHICH HAS LED TO LOWER CONFIDENCE. BETTER CHANCE AT SUB-
VFR OVER THE CAPE AND ISLANDS WITH PATCHY LIFR STRATUS AND
MIST/FOG.
THURSDAY: HIGH CONFIDENCE.
ANY PATCHY FOG AND STRATUS WHICH DEVELOPED OVERNIGHT SHOULD DISSIPATE
BY EARLY THURS MORNING TO VFR. CEILINGS START TO LOWER AGAIN
INTO BORDERLINE VFR RANGE LATE IN THE DAY IN INTERIOR/WESTERN
AIRPORTS. NW WINDS 5 KT THEN SHIFT TO NE/E BY AFTERNOON.
THURSDAY NIGHT: MODERATE CONFIDENCE.
DETERIORATING CONDITIONS THURS NIGHT WITH SUB-VFR CEILINGS AND
STEADY RAIN MAINLY W OF ORH. NE/E WINDS AROUND 10-15 KT.
KBOS TAF...HIGH CONFIDENCE.
KBDL TAF...HIGH CONFIDECE. MODERATE ON BR POTENTIAL OVERNIGHT.
LIGHT SW WINDS BECOMING NW BY EARLY THURSDAY MORNING. CHANCE FOR
PATCHY BR AFTER MIDNIGHT THROUGH AROUND 12Z.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH FRIDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE.
BREEZY. RA.
SATURDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY. CHANCE
RA.
SATURDAY NIGHT THROUGH MONDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS:
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH THURSDAY: HIGH CONFIDENCE.
WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERION THROUGH THIS
PERIOD.
SW WINDS AROUND 15 KT THRU TONIGHT, THEN WILL BECOME LIGHTER NW
INTO OVERNIGHT AND THURSDAY. WINDS THEN INCREASE FROM THE E/ENE
THURS AFTN AND EVENING TO AROUND 20 KT, WITH AN OUTSIDE CHANCE
AT SCA LEVEL GUSTS ON NORTHEAST WATERS.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE OF RAIN.
FRIDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. RAIN.
SATURDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE OF
RAIN.
SATURDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT.
SUNDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
SUNDAY NIGHT: WINDS LESS THAN 25 KT.
MONDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
SYNOPSIS...LOCONTO
NEAR TERM...LOCONTO
SHORT TERM...LOCONTO
LONG TERM...LOCONTO
AVIATION...LOCONTO/MENSCH
MARINE...LOCONTO
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