440
FXUS61 KBOX 071142
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
742 AM EDT MON JUL 7 2025
SYNOPSIS
HIGHER THAN NORMAL HEAT AND HUMIDITY EXPECTED TODAY WITH A HEAT
ADVISORY IN PLACE. UNSETTLED WEATHER MAKES A RETURN LATE TODAY INTO
TONIGHT, CONTINUING OFF AND ON THROUGH MUCH OF NEXT WEEK. TUESDAY
SOME ISOLATED SEVERE STORMS ARE POSSIBLE AS WELL AS HEAVY DOWNPOURS
AND LOCALIZED FLASH FLOODING. COOLER WEATHER EXPECTED MID TO LATE
WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES...
* MILD THIS MORNING WITH PATCHY FOG FOR THE SOUTH COAST AND ISLANDS.
* WARMER THAN NORMAL TODAY AND VERY HUMID.
* ISOLATED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON, MAINLY FOR
WESTERN CT AND MA.
HAVE BEGUN TO SEE SATELLITE AND SURFACE OB EVIDENCE OF FOG/LOW
STRATUS MENTIONED BY THE PREVIOUS FORECASTER MAKING ITS WAY SLOWLY
NORTH/INLAND INTO THE SOUTH COAST/COASTAL PLAIN OF MA AND SOUTHERN
RI. HI-RES GUIDANCE CONTINUES TO INDICATE THIS SHOULD BE CONFINED
SOUTH OF THE MA PIKE, IF THAT FAR NORTH; MODEL SOUNDINGS INDICATE
THAT THESE LOW CLOUDS COULD BE CONFINED TO THE CAPE/ISLANDS AND THE
IMMEDIATE COASTLINE WHICH I THINK IS MOST LIKELY. EVEN AFTER
SUNRISE, HI-RES GUIDANCE INDICATES IT MAY BE HARD TO MIX OUT THESE
LOW CLOUDS EVEN THROUGH THE AFTERNOON. ELSEWHERE, THOUGH, A MIX OF
CLOUDS AND SUN IS EXPECTED TODAY AS WEAK MID LEVEL RIDGING KEEPS
THINGS MOSTLY QUIET/DRY TO START. TOWARD THE LATTER HALF OF THE DAY
A SHORTWAVE APPROACHES SNE WHICH WILL ACT ON ABUNDANT/ANOMALOUS
MOISTURE (PWAT PLUME OF 2+ INCHES) TO PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS, MOST LIKELY IN WESTERN MA AND CT. FORCING IS QUITE
WEAK FOR ANY STORMS, AS ARE BULK SHEAR VALUES AND MID LEVEL LAPSE
RATES. THIS MEANS THAT WHILE WE HAVE LOWER CONFIDENCE OF EXACTLY
WHERE THUNDERSTORMS WILL FORM, ANY THAT DO SHOULD NOT BE SEVERE.
THEY WILL, HOWEVER, HAVE THE LOW CHANCE FOR HEAVY DOWNPOURS AND
LOCALIZED FLASH FLOODING. THE GREATER CONCERN, THOUGH, COMES ON
TUESDAY WITH THE ARRIVAL OF BETTER FORCING AHEAD OF THE COLD FRONT.
HEAT AND HUMIDITY REMAIN, AND IT IS WITHIN THE REALM OF POSSIBILITY
THAT THE HEAT ADVISORY WILL NEED TO BE EXPANDED INTO TUESDAY FOR
SOME AREAS. HOWEVER, CONFIDENCE IS NOT HIGH ENOUGH THAT THE SAME
LOCATIONS THAT SAW THE HIGHEST APPARENT TEMPS ON PREVIOUS DAYS WILL
EXPERIENCE TEMPS NECESSITATING AN EXTENSION AT THIS TIME.
TONIGHT WE REMAIN IN THE WARM, MUGGY ENVIRONMENT KEEPING LOWS VERY
MILD, LIMITED BY THE ELEVATED DEWPOINTS, IN THE LOW 70S. FOG AND LOW
STRATUS WILL LIKELY BE MORE WIDESPREAD WITH NEAR ZERO DEWPOINT
DEPRESSIONS. SHOWERS ARE POSSIBLE OVERNIGHT, MAINLY OVER
SOUTHEASTERN NEW ENGLAND ASSOCIATED WITH CONVERGENCE AROUND A WEAK
SURFACE LOW.
SHORT TERM /TUESDAY/
KEY MESSAGES...
* SHOWERS AND THUNDERSTORMS TUESDAY.
* ISOLATED STRONG TO SEVERE STORMS POSSIBLE WITH HEAVY DOWNPOURS AND
POTENTIAL FOR LOCALIZED FLASH FLOODING.
TUESDAY THE UNSETTLED WEATHER WILL BE MORE WIDESPREAD ACROSS
SOUTHERN NEW ENGLAND AS SYNOPTIC AND MESOSCALE FORCING FOR ASCENT
INCREASE WITH PASSING OF A MID LEVEL VORT MAX AND APPROACHING
SURFACE COLD FRONT. TEMPERATURES IN THE UPPER 80S/LOW 90S WITH
DEWPOINTS IN THE 70S WILL CONTRIBUTE TO INSTABILITY ON THE ORDER OF
1500-2000 J/KG OF CAPE. HOWEVER, OTHER PARAMETERS ARE LESS FAVORABLE
FOR SEVERE WEATHER, NAMELY MID LEVEL LAPSE RATES NEAR 5-5.5 C/KM AND
0-6KM BULK SHEAR <25KTS. EVEN SO, CAN'T RULE OUT AN ISOLATED STRONG
TO SEVERE STORM PRODUCING DAMAGING WIND GUSTS. THE GREATER RISK
GIVEN THE WEAK STEERING FLOW AND ABUNDANT AFOREMENTIONED
MOISTURE/SKINNY CAPE PROFILES WILL BE HEAVY DOWNPOURS LEADING TO
FLASH FLOODING. THE AREA REMAINS WITHIN A MARGINAL RISK (LEVEL 1 OF
4) OF EXCESSIVE RAINFALL LEADING TO FLASH FLOODING TUESDAY,
ESPECIALLY TUESDAY AFTERNOON AND EVENING.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
KEY MESSAGES...
* PERIODIC CHANCES OF UNSETTLED WEATHER EACH DAY THROUGH AT LEAST
FRIDAY.
* SEASONABLE TO EVEN COOLER THAN AVERAGE TEMPS BY LATE WEEK.
A STEADY STREAM OF MOISTURE IS DIRECTED INTO NEW ENGLAND WITH PWATS
NEAR 2 INCHES CLEAR THROUGH AT LEAST THURSDAY. THIS TOGETHER WITH
QUASI-ZONAL FLOW AND PERIODIC MID LEVEL DISTURBANCES MOVING THROUGH
THE MID LEVEL FLOW WILL LEAD TO CHANCES FOR SHOWERS AND
THUNDERSTORMS ESSENTIALLY EACH DAY THROUGH AT LEAST FRIDAY.
FOLLOWING THAT THERE ARE HINTS OF A MID LEVEL RIDGE APPROACHING FOR
THE WEEKEND, BUT TOO SOON TO NAIL DOWN TIMING ON THIS FEATURE.
WHAT'S MORE CERTAIN IS THE RETURN TO SEASONAL TO COOLER THAN AVERAGE
TEMPERATURES BY THURSDAY INTO THE WEEKEND COURTESY OF
ONSHORE/EASTERLY FLOW COMBINED WITH A COOLER AIRMASS ALOFT.
AVIATION /12Z MONDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z UPDATE...
TODAY...MODERATE CONFIDENCE.
MVFR TO IFR ALONG THE SOUTH COAST OF RI AND MA SCATTERING OUT
12-14Z. CAPE/ISLANDS STRUGGLE TO IMPROVE TODAY, GRADUALLY
IMPROVING INTO THE EARLY AFTERNOON. SSW TO SW WINDS 10-15 KTS,
GUSTS 20-24 KTS BY EARLY AFTERNOON. ISOLATED SHOWERS AND FEW
THUNDERSTORMS MAY DEVELOP AFTER 16Z, BUT LOW CONFIDENCE ON WHERE
ANY STORMS WILL FORM.
TONIGHT...MODERATE CONFIDENCE.
IFR CIGS EXPAND FROM THE SOUTH COAST INTO MOST TERMINALS BY
06-10Z. WINDS LIGHT.
TUESDAY...MODERATE CONFIDENCE.
VFR. W WINDS 5-10 KTS. SCATTERED SHRA/TSRA WITH HEAVY DOWNPOURS
LIKELY IN THE AFTERNOON AND EVENING.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.
LOW CLOUDS DEVELOP TO THE SOUTH EARLY THIS MORNING, BUT ARE
UNLIKELY TO REACH THE TERMINAL. BKN MID-LEVEL CEILINGS MONDAY
WITH SW WINDS WITH GUSTS AROUND 20 KTS IN THE AFTERNOON. LOW
CHANCE FOR AN ISOLATED SHOWER/STORM MAKES IT EAST TO TO BOS
AFTER 18Z.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
FORECAST CONFIDENCE IS MODERATE BEYOND 10Z WITH THE POTENTIAL
FOR LOWER CEILINGS. ISOLATED -SHRA/-TSRA POSSIBLE AFTER 16Z.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL
IFR POSSIBLE. CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY THROUGH THURSDAY NIGHT: MAINLY VFR, WITH AREAS IFR
POSSIBLE. CHANCE SHRA, SLIGHT CHANCE TSRA.
FRIDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. 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.
TODAY AND TONIGHT: HIGH CONFIDENCE.
AFTER A BRIEF LULL THIS MORNING, SW WINDS INCREASE IN THE AFTERNOON
TO 10-15 KTS WITH GUSTS 20-25 KTS ON SOUTHERN WATERS, 25-30 KTS ON
THE EASTERN WATERS. WILL LIKELY NEED A SCA FOR THE NORTH OUTER
WATERS ZONE. SEAS 2-3 FT, INCREASING TO 2-4 FT ON THE OUTER WATERS
LATE IN THE DAY. SEAS INCREASE TO 5 FT FOR THE SOUTHERN OUTER WATERS
AFTER OVERNIGHT INTO TUESDAY.
TUESDAY: HIGH CONFIDENCE.
SW WINDS 15-20 KTS WITH SEAS 2-4 FT ON THE EASTERN WATERS, 3-6 FT ON
THE SOUTHERN WATERS.
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF RAIN SHOWERS, CHANCE OF THUNDERSTORMS.
WEDNESDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY
APPROACHING 5 FT. CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF
THUNDERSTORMS.
THURSDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
CHANCE OF RAIN SHOWERS.
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT. CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF
THUNDERSTORMS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ003>007-
010>019-026.
RI...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...NONE.
SYNOPSIS...BW
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...BW
AVIATION...BW/MCMINN
MARINE...BW
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