383
FXUS61 KBOX 101724
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
124 PM EDT SUN AUG 10 2025
SYNOPSIS
HIGH PRESSURE OFF THE COAST WILL BRING INCREASING HEAT AND HUMIDITY
THROUGH MID WEEK, BUT IT WILL NOT BE AS OPPRESSIVE AS IT WAS EARLIER
IN THE SUMMER. AN ISOLATED THUNDERSTORM IS POSSIBLE LATE WEDNESDAY
ACROSS WESTERN PORTIONS OF MA AND CT. THEN NOT AS HOT THURSDAY,
ALONG WITH SCATTERED SHOWERS OR THUNDERSTORMS, AS A COLD FRONT MOVES
THROUGH. DRIER WEATHER FOLLOWS FRIDAY INTO NEXT WEEKEND.
NEAR TERM /THROUGH TONIGHT/
130 PM UPDATE...
KEY MESSAGES:
* WARMER THIS AFTERNOON WITH SOME 90 DEGREE HIGHS INLAND
REST OF TODAY...
BEAUTIFUL SUMMER AFTERNOON IN PROGRESS, WITH TEMPS WARMING THRU THE
80S, EXCEPT 70S ALONG THE IMMEDIATE COAST AND ISLANDS, IN RESPONSE
TO COOLER ONSHORE FLOW. SOME INLAND LOCATIONS WILL APPROACH 90 LATER
THIS AFTERNOON, WITH TEMPS ALOFT OF +23C AT 925 MB AND +17C AT 850
MB. HUMIDITY LEVELS ARE TOLERABLE FOR THIS TIME OF YEAR, WITH DEW
PTS IN THE UPPER 50S TO LOW/MID 60S.
TONIGHT WILL FEATURE CLEAR SKIES ONCE AGAIN, WITH PATCHY FOG IN
VALLEYS AND NEAR CAPE COD/ISLANDS. SOME LOW CLOUDS MAY IMPACT THE
OUTER CAPE AND ISLANDS AT TIMES OVERNIGHT. GIVEN THE RADIATIONAL
COOLING CONDITIONS, THE LOWER MOS MINS LOOK MORE REASONABLE THAN THE
NBM. ALSO, GIVEN THE MODEST DEW PTS, STILL COOL-ISH TONIGHT WITH
LOWS MAINLY IN THE 60S, UPPER 50S IN THE COOLER INLAND VALLEYS AND
CLOSER TO 70 IN BOSTON.
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
130 PM UPDATE...
KEY MESSAGES:
* INCREASING HEAT AND HUMIDITY MONDAY, BUT PROBABLY JUST SHY OF HEAT
ADVISORY CRITERIA
MONDAY...
UPPER RIDGE CONTINUES TO DOMINATE YIELDING ABUNDANT SUNSHINE.
INCREASING SW FLOW BRINGS SOMEWHAT MORE HUMID AIR INTO REGION, BUT
NOT AS OPPRESSIVE AS WHAT WE EXPERIENCED EARLIER IN SUMMER. ALSO,
WITH SOLAR SUMMER BEHIND US (90 DAYS OF HIGHEST SUN ANGLE FROM EARLY
MAY TO EARLY AUG), THE HEAT IS NOT AS INTENSE AS JUNE AND JULY. IN
ADDITION, GRADIENT REMAINS WEAK ENOUGH TO ALLOW FOR SOME RELIEF
ALONG BOTH COASTS, IN THE FORM OF AFTERNOON SEA BREEZES. THUS,
DESPITE THE COMBINATION OF HIGHS IN LOW TO MID 90S INLAND AND
DEWPOINTS CLIMBING INTO MID 60S, THE HEAT INDEX LIKELY REMAINS
HEADLINE CRITERIA. THEREFORE, GIVEN THE MARGINAL HEAT CONDITIONS AND
OTHER FACTORS MENTIONED ABOVE, WE WILL HOLD OFF ON HEAT HEADLINES
FOR NOW. BETTER CHANCE LOOKS TO BE TUE AND ESPECIALLY WED, WHEN
HUMIDITY INCREASES FURTHER.
MONDAY NIGHT...DEEP LAYER RIDGE CONTINUES TO PROVIDE QUIET/TRANQUIL
WEATHER CONDITIONS. SLIGHTLY HIGHER DEW PTS MAY YIELD A BIT MORE
PATCHY FOG AND LOW CLOUDS, ESPECIALLY COMING ONSHORE TO THE SOUTH
COAST. SEASONABLY MILD WITH LOWS IN THE 60S, A FEW UPPER 50S
NORTHWEST MA AND AROUND 70 IN BOSTON. WINDS LIGHT AND VARIABLE.
LONG TERM /TUESDAY THROUGH SATURDAY/
KEY MESSAGES:
* PEAK OF HEAT AND HUMIDITY WED.
* HEAT MAY LAST INTO THU BEFORE PM CLOUDS/POSSIBLE STORMS.
* COOLER FRI AND INTO WEEKEND.
HEAT AND HUMIDITY SHOULD PEAK WED WITH BROAD SW FLOW. STILL
LOOKS MARGINAL FOR HEAT ADVISORY CRITERIA WITH HIGHS INLAND
REACHING 90-95 AND DEWPOINTS INTO MID 60S, AND FAVORED AREAS
CONTINUING TO BE PARTS OF CT AND MERRIMACK VALLEYS INTO NORTHERN
RI AND EASTERN MA. IT'S ALSO POSSIBLE THAT CLOUDINESS WORKS
INTO SNE WED AFTERNOON, LIMITING HEATING BEFORE SCATTERED
THUNDERSTORMS ARRIVE LATER IN DAY.
UPPER RIDGE GETS SUPPRESSED THU AS SHORT WAVE MOVES THROUGH
GREAT LAKES. THIS SHOULD BRING COLD FRONT THROUGH REGION,
ACCOMPANIED BY SHOWERS AND STORMS, ALTHOUGH COVERAGE MAY BE MORE
HIT AND MISS, BEFORE COOLER AND DRIER WEATHER FOLLOWS FRI AND
INTO WEEKEND.
AVIATION /18Z SUNDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE: HIGH CONFIDENCE.
VFR, ASIDE FROM LOCAL MVFR/IFR VSBYS POSSIBLE DUE TO PATCHY FOG
ACROSS INTERIOR VALLEYS AND NEAR CAPE COD AND ISLANDS LATE
TONIGHT. LIGHT S/SW WINDS EXPECTED WITH SEA BREEZES ALONG BOTH
COASTS TODAY AND MON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /TUESDAY THROUGH THURSDAY/...
TUESDAY & TUESDAY NIGHT: VFR.
WEDNESDAY: VFR. BREEZY.
WEDNESDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE
TSRA.
THURSDAY: VFR. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MEDIUM - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
130 PM UPDATE...
HIGH CONFIDENCE THROUGH THE PERIOD.
WEAK GRADIENT WILL ALLOW FOR SEA BREEZES NEAR SHORE THROUGH AT LEAST
MONDAY NIGHT, BEFORE HIGH PRESSURE OFFSHORE BRINGS SW FLOW
THEREAFTER. WINDS AND SEAS SHOULD REMAIN BELOW SCA LEVELS.
PATCHY FOG MAY LIMIT VISIBILITY LATER AT NIGHT AND EARLY IN
MORNING.
OUTLOOK /TUESDAY THROUGH THURSDAY/...
TUESDAY THROUGH WEDNESDAY: WINDS LESS THAN 25 KT.
WEDNESDAY NIGHT THROUGH THURSDAY: WINDS LESS THAN 25 KT. SLIGHT
CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
SYNOPSIS...NOCERA
NEAR TERM...NOCERA
SHORT TERM...NOCERA
LONG TERM...JWD
AVIATION...JWD/NOCERA
MARINE...JWD
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