190
FXUS61 KBOX 141749
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
149 PM EDT THU AUG 14 2025
SYNOPSIS
ONE MORE DAY OF SCATTERED SHOWERS AND THUNDERSTORMS TODAY ALONG WITH
A LOW RISK FOR SOME URBAN FLASH FLOODING. SEASONABLE TEMPERATURES
AND LOWER HUMIDITY LEVELS ARE EXPECTED FOR FRIDAY AND SATURDAY,
ALTHOUGH TEMPERATURES BRIEFLY WARM UP AGAIN FOR SUNDAY. AFTER
MIDWEEK, OUR NEXT CHANCE FOR RAIN IS WITH A COLD FRONT WHICH LOOKS
TO MOVE IN ON MONDAY.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES...
* PATCHY FOG POSSIBLE THIS MORNING ACROSS SOUTHEAST MA AND COASTAL
RI.
* SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE THIS AFTERNOON AND
EVENING, SOME OF WHICH COULD LEAD TO LOCALIZED URBAN FLASH
FLOODING.
TODAY AS A SUBTLE SHORTWAVE IN THE MID LEVEL FLOW MAKES ITS WAY
ACROSS NEW ENGLAND WE'LL SEE A SURFACE LOW AND ITS ASSOCIATED COLD
FRONT BRING MORE WET WEATHER TO THE REGION, SOME OF WHICH MAY BE
SIGNIFICANT. HOWEVER, SIGNALS ARE MIXED/POOR FOR WIDESPREAD
EXCESSIVE RAINFALL ISSUES. THE SURFACE LOW SLOWLY MOVING WEST TO
EAST WILL DRAPE A COLD FRONT ACROSS SOUTHERN NEW ENGLAND WHICH
STALLS THIS AFTERNOON AND EVENING BEFORE FINALLY PUSHING OUT
OVERNIGHT. AHEAD OF THIS FRONT A PLUME OF ANOMOLOUSLY DEEP MOISTURE
SITS OVER MUCH OF THE REGION, ESPECIALLY SOUTHEAST MA AND RI WHERE
PWATS NEAR 2 INCHES. THIS, TOGETHER WITH TALL-SKINNY CAPE PROFILES,
DEEP WARM CLOUD DEPTHS, AND SLOW STORM MOTION WILL MEAN A RISK OF
SOME STORMS BRINGING HEAVY DOWNPOURS THAT COULD LEAD TO LOCALIZED
DOWNPOURS. THE LOCATION OF THE GREATEST RISK WILL LIKELY ALIGN WITH
THE STALLED FRONT WHICH, WHILE STILL UNCERTAIN, CONTINUES TO LOOK TO
BE ALONG THE I-95 CORRIDOR OF RI AND CT. HOWEVER, ANY FLOODING
ISSUES ARE EXPECTED TO BE ISOLATED AS OPPOSED TO WIDESPREAD. ONE FLY
IN THE OINTMENT MAY BE CLOUDCOVER LIMITING HOW MUCH INSTABILITY IS
REALIZED; ADDITIONALLY, THE 00Z HREF HAS REALLY BACKED OFF ON THE
PROBS FOR 6-HOUR RAINFALL EXCEEDING 10-YEAR ARIS, DOWN TO 5-15%
FROM AS HIGH AS 40% YESTERDAY. OVERALL, THE THREAT REMAINS AND
WE CONTINUE TO CARRY THE MARGINAL RISK (LEVEL 1 OR 4) OF FLASH
FLOODING. THE POSITIVELY TROPICAL-FEELING AIRMASS CONTINUES FOR
ONE MORE DAY AS HIGHS REACH WELL INTO THE 80S WITH DEWPOINTS IN
THE 70S.
SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/
KEY MESSAGES...
* DRIER AIR MOVES IN THURSDAY NIGHT INTO FRIDAY LEADING TO COOLER
TEMPS AND DRY WEATHER.
ONCE THE FRONT KICKS OUT TONIGHT ANY LINGERING SHOWERS AND
THUNDERSTORMS COME TO AN END. DEWPOINT WILL DROP QUITE A BIT AS A
DRIER AIRMASS WORKS IN, ESPECIALLY NORTH AND WEST WHERE DEWPOINTS IN
THE UPPER 50S AND LOW 60S ARE LIKELY. CLOSER TO THE SOUTH COAST,
WHILE IT WILL BE LESS HOT AND HUMID FRIDAY, DEWPOINTS REMAIN IN THE
MID TO UPPER 60S. PLENTY OF SUN, WITH HIGH TEMPERATURES IN THE UPPER
80S WEST, UPPER 70S ON THE EAST COAST THANKS TO THE COOLER
NORTHEASTERLY (ONSHORE) FLOW.
LONG TERM /SATURDAY THROUGH THURSDAY/
KEY MESSAGES:
* COOLER WITH LOWER HUMIDITY LEVELS SAT
* WARMER AND MORE HUMID SUNDAY WITH CHANCES FOR
SHOWERS/THUNDERSTORMS IN AFTERNOON/EVENING.
* COOLER NEXT WEEK WITH POTENTIAL FOR SOME SCATTERED SHOWERS TUES-
THURS IN SPOTS.
SATURDAY:
OVERNIGHT TEMPERATURES WILL BE COOLER WITH LOWS IN THE MID 50S
TO LOW 60S FRIDAY NIGHT. SIMILAR CONDITIONS TO FRIDAY ARE
EXPECTED ON SATURDAY WITH THE SURFACE HIGH PRESSURE CENTER
OFFSHORE WITH MAINLY SUNNY SKIES, SEASONABLE TEMPERATURES IN THE
80S, AND EASTERLY COMPONENT FLOW.
SUNDAY:
A SHORTWAVE TROUGH IN THE MID-LEVEL FLOW ALOFT MOVES THROUGH ON
SUNDAY. SURFACE WINDS TURN MORE SOUTHWESTERLY WITH ADVECTION OF HIGH
MOISTURE/DEWPOINT AIR INTO SOUTHERN NEW ENGLAND WITH WARM AIR
ADVECTION. HIGHS WILL BE WARMER IN THE MID 80S TO NEAR 90 WITH
ELEVATED HUMIDITY LEVELS MAKING IT FEEL LIKE LOW TO MID 90S. DAYTIME
HEATING, MOISTURE, AND AN APPROACHING FRONT/SHORTWAVE SHOULD SUPPORT
DEVELOPMENT OF AFTERNOON SHOWERS AND THUNDERSTORMS. DETERMINISTIC
AND ENSEMBLE GUIDANCE SHOW AT LEAST MARGINAL INSTABILITY IN PLACE
WITH SOME UNCERTAINTY ON HOW FAR EAST THE INSTABILITY AXIS EXTENDS
INTO SOUTHERN NEW ENGLAND.
NEXT WEEK:
THE COLD FRONT WILL PUSH THROUGH THE REGION OVERNIGHT SUNDAY INTO
EARLY MONDAY BRINGING IN A COOL AIRMASS TO START THE WEEK. ENSEMBLE
GUIDANCE SHOWS THE AIRMASS TO BE BELOW NORMAL WITH 850MB
TEMPERATURES 10-12C. THIS WILL BRING MUCH COOLER HIGHS IN THE 70S,
PERHAPS A FEW 80S IN THE CT VALLEY. FLOW ALOFT WILL BE GENERALLY
WEAK TROUGHING WITH A WEAK SHORTWAVE OR TWO MOVING THROUGH DURING
THE WEEK. THIS MAY BRING WEAK ISOLATED TO SCATTERED SHOWERS. GIVEN
FAIRLY WEAK FORCING AND UNCERTAINTY IN TIMING OF THE WAVES THIS FAR
OUT, TIMING OF PRECIPITATION IS LOW CONFIDENCE STILL. ALTHOUGH THERE
SEEMS TO BE CHUNKS OF MEMBERS SHOWING HIGHER PROBABILITIES FOR
SEEING SHOWERS TUESDAY/WEDNESDAY AND POTENTIALLY INTO THURSDAY.
CONFIDENCE SHOULD INCREASE AS WE GET CLOSER, BUT OVERALL NOT
EXPECTING ANY SIGNIFICANT RAINFALL WITH THESE WEAKER SHORTWAVES.
AVIATION /17Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
TODAY...MODERATE CONFIDENCE OVERALL. LOW CONFIDENCE IN
PLACEMENT/TIMING OF SHOWERS/STORMS.
SCATTERED SHOWERS AND T-STORMS ARE POSSIBLE AGAIN THIS
AFTERNOON AND EVENING. CONFIDENCE IS LOWER WITH RESPECT TO
TIMING AND CHANCES AS COVERAGE IS MORE SCATTERED IN NATURE.
LIGHTNING, BRIEF GUSTY WINDS/OUTFLOWS, AND HEAVY RAIN POSSIBLE
IN ANY STORMS.
TONIGHT...MODERATE CONFIDENCE.
VFR. A FEW LINGERING SHOWERS AND STORMS POSSIBLE EARLY IN THE
EVENING. VFR FOR MOST TERMINALS. POTENTIAL FOR LOW STRATUS AND
FOG/MIST FOR CAPE/ISLANDS TONIGHT.
FRIDAY...HIGH CONFIDENCE.
VFR. NE WINDS 5-10 KTS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOWER CONFIDENCE IN
TSRA CHANCES TODAY, BUT WOULD LIKELY BE IN THE 20-23Z.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. COULD SEE SOME POP-
UP SHOWERS/T-STORMS THIS EVENING, BUT CONFIDENCE IS TOO LOW TO
MENTION IN TAF.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY THROUGH SATURDAY NIGHT: VFR.
SUNDAY: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
SUNDAY NIGHT THROUGH MONDAY: VFR. BREEZY. SLIGHT CHANCE SHRA.
MONDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
TUESDAY: BREEZY. SLIGHT CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THE PERIOD.
WINDS INCREASE OUT OF THE SOUTHWEST TO 10 TO 15 KNOTS THIS
AFTERNOON WITH A SLIGHT CHANCE FOR AN AFTERNOON/EVENING
THUNDERSTORM. STORMS SHOULD DIMINISH SHORTLY AFTER MOVING OUT
OVER THE WATERS IF THEY MAKE IT THAT FAR.
SEAS REMAIN IN THE 2-3 FOOT RANGE. A COLD FRONT WILL CROSS THE
COASTAL WATERS LATE TOMORROW AFTERNOON RESULTING IN A WIND SHIFT
TO THE NORTHWEST. OVERALL QUIET CONDITIONS OVER THE MARINE
ZONES FOR THE FORESEEABLE FUTURE.
OUTLOOK /SATURDAY THROUGH TUESDAY/...
SATURDAY THROUGH SATURDAY NIGHT: WINDS LESS THAN 25 KT.
SUNDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS LOCALLY APPROACHING 5 FT. SLIGHT CHANCE
OF RAIN SHOWERS.
MONDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN SHOWERS.
MONDAY NIGHT THROUGH TUESDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
SYNOPSIS...MCMINN/MENSCH
NEAR TERM...KJC/MCMINN
SHORT TERM...KJC/MCMINN
LONG TERM...MENSCH
AVIATION...KJC/MCMINN/MENSCH
MARINE...MCMINN
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page