517  
FXUS61 KBOX 111816  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
216 PM EDT MON AUG 11 2025  
   
SYNOPSIS
 
 
HEAT AND HUMIDITY ON THE RISE THIS WEEK, PEAKING ON WEDNESDAY,  
BUT NOT AS OPPRESSIVE AS IT WAS EARLIER IN THE SUMMER. SCATTERED  
SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD OF A COLD FRONT  
LATER WEDNESDAY AND THURSDAY, THEN DRY AND COOLER WEATHER  
FOLLOWS FRIDAY INTO THE WEEKEND, BUT HEAT COULD RETURN SUNDAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
KEY MESSAGE:  
 
* HOT AND HUMID TODAY WITH CLEAR SKIES.  
 
HIGH PRESSURE BUILDING SOUTH OF OUR WATERS IS PROVIDING  
SOUTHWESTERLY FLOW (WITH THE EXCEPTION OF SEA BREEZES ALONG THE  
COASTS)... BRINGING HOT AND HUMID AIR OVER SOUTHERN NEW ENGLAND.  
THIS AFTERNOON'S TEMPERATURES WILL PEAK IN THE LOW 90S FOR MOST  
AREAS... UPPER 80S FOR THE SOUTH COAST, CAPE AND ISLANDS.  
 
ANOTHER MAINLY CLEAR NIGHT AHEAD WITH PATCHY FOG POSSIBLE NEAR  
CAPE COD/ISLANDS AND PERHAPS INLAND AS WELL. GIVEN THE CLEAR  
SKIES AND LOW WINDS, EXPECTING SOME RADIATIONAL COOLING TONIGHT  
ALLOWING THE CT RIVER VALLEY AND MERRIMACK VALLEY TO DROP INTO  
THE LOW 60S.  
 

 
   
SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/
 
 
KEY MESSAGES:  
 
* HEAT AND HUMIDITY CONTINUE TO RISE TUESDAY, BUT STILL SHORT OF  
A HEAT ADVISORY.  
 
WHILE HEAT AND HUMIDITY CONTINUE TO RISE THROUGH MIDWEEK,  
FORECAST SOUNDINGS ON TUESDAY INDICATE FAIRLY DEEP MIXING...  
BRINGING DOWN DRIER AIR FROM ALOFT AND LOWERING AFTERNOON  
DEWPOINTS INTO UPPER 50S AND LOWER 60S. THIS WILL REDUCE THE  
APPARENT TEMPERATURES TUESDAY AFTERNOON. WHILE WE'LL COME CLOSE  
TO HEAT ADVISORY CRITERIA (HEAT INDEX OF 95-100F FOR 2 OR MORE  
HOURS) STILL THINKING WE'LL FALL SHORT OF THE 2 CONSECUTIVE DAY  
THRESHOLD. REGARDLESS, IT WILL BE HOT AND HUMID, ALTHOUGH NOT TO  
EXTENT AS WHAT WE EXPERIENCED EARLIER IN THE SUMMER.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/
 
 
KEY MESSAGES:  
 
* LOW RISK OF SEVERE STORMS THU AS COLD FRONT MOVES THROUGH.  
* COOLER FRI/SAT BUT HEAT MAY RETURN SUN.  
 
DEPENDING ON HOW THINGS EVOLVE WED WITH RESPECT TO CONVECTION,  
INCLUDING CLOUD DEBRIS WHICH COULD LIMIT HEATING THU,  
APPROACHING COLD FRONT MAY BRING A ROUND OF SEVERE STORMS THU  
BUT RIGHT NOW ODDS SEEM TO BE FAIRLY LOW DUE TO TIMING  
DIFFERENCES, EVEN IN ML GUIDANCE. FAVORED AREAS RIGHT NOW  
INCLUDE EASTERN MA AND RI WHERE HEATING MAY BE MAXIMIZED BUT  
CONFIDENCE IS LOW ON EXACTLY WHERE THAT WILL BE.  
 
FRONT MOVES OFFSHORE EARLY FRI LEADING TO DRIER AND COOLER  
WEATHER FRI AND SAT AS UPPER RIDGE BECOMES SUPPRESSED, BUT RIDGE  
TRIES TO REASSERT ITSELF ONCE AGAIN LATER IN WEEKEND, PROBABLY  
LEADING TO A RETURN OF HEAT AND HUMIDITY SUN AND INTO NEXT WEEK.  
 

 
   
AVIATION /18Z MONDAY THROUGH FRIDAY/
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
18Z TAF UPDATE: HIGH CONFIDENCE.  
 
VFR. LIGHT S/SW WINDS WITH SEA BREEZES ALONG BOTH COASTS TODAY  
AND TUE.  
 
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.  
 
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.  
 
OUTLOOK /WEDNESDAY THROUGH FRIDAY/...  
 
WEDNESDAY: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.  
 
WEDNESDAY NIGHT: VFR. BREEZY. CHANCE SHRA, SLIGHT CHANCE TSRA.  
 
THURSDAY: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.  
 
THURSDAY NIGHT: VFR. SLIGHT CHANCE SHRA.  
 
FRIDAY THROUGH SATURDAY: VFR.  
 

 
   
MARINE
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
HIGH CONFIDENCE THROUGH THE PERIOD.  
 
WEAK GRADIENT WILL ALLOW FOR SEA BREEZES NEAR SHORE TODAY AND  
TUE BEFORE HIGH PRESSURE OFFSHORE BRINGS INCREASING SW FLOW  
THEREAFTER, THOUGH WINDS AND SEAS SHOULD REMAIN BELOW SCA  
LEVELS. PATCHY FOG MAY LIMIT VISIBILITY LATER AT NIGHT AND EARLY  
IN MORNING FOR MUCH OF THIS WEEK.  
 
OUTLOOK /WEDNESDAY THROUGH FRIDAY/...  
 
WEDNESDAY: WINDS LESS THAN 25 KT.  
 
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. CHANCE OF RAIN SHOWERS.  
 
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN  
SHOWERS.  
 
FRIDAY THROUGH SATURDAY: WINDS LESS THAN 25 KT.  
 

 
   
BOX WATCHES/WARNINGS/ADVISORIES
 
 
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002>004.  
MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>016-  
026.  
RI...NONE.  
MARINE...NONE.  
 

 
 

 
 
SYNOPSIS...LOCONTO/MCMINN  
NEAR TERM...MCMINN  
SHORT TERM...MCMINN  
LONG TERM...LOCONTO  
AVIATION...LOCONTO/MCMINN  
MARINE...LOCONTO/MCMINN  
 
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