035  
FXUS61 KBOX 130812  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
412 AM EDT MON JUL 13 2026  
   
WHAT HAS CHANGED  
 
A HEAT ADVISORY HAS BEEN ISSUED TUESDAY INTO WEDNESDAY FOR MUCH  
OF SOUTHERN NEW ENGLAND. HEAT INDICES ARE LIKELY TO REACH  
100-103 IN SOME AREAS.  
 
 
   
KEY MESSAGES  
 
- DRY AND COMFORTABLE CONDITIONS CONTINUE TODAY.  
 
- HEAT AND HUMIDITY RETURN MIDWEEK. HEAT ADVISORIES GO INTO  
EFFECT TUESDAY MORNING THROUGH WEDNESDAY EVENING.  
 
- PERIODS OF UNSETTLED WEATHER POSSIBLE LATER THIS WEEK AS AN  
UPPER LEVEL TROUGH PUSHES OVER THE REGION.  
 
 
   
DISCUSSION  
 
KEY MESSAGE 1...DRY AND COMFORTABLE CONDITIONS CONTINUE TODAY.  
 
BROAD HIGH PRESSURE CONTINUE TO SIT OF NEW ENGLAND TODAY,  
PUSHING OFFSHORE LATER TONIGHT. SOME LOW-END POPS ACROSS  
NORTHERN AND WESTERN MA HAVE BEEN INCLUDED DUE TO THE PASSAGE OF  
A WEAK SHORTWAVE TROUGH LATER THIS AFTERNOON, BUT ANY SHOWERS  
WILL BE SCATTERED AND SUB-SEVERE IN NATURE. OTHERWISE, MOST  
AREAS WILL REMAIN DRY THROUGH THE DAY, AND SOUTH-SOUTHWESTERLY  
FLOW WILL ALLOW FOR TEMPERATURES IN THE MID TO UPPERS 80S WITH  
HEAT INDICES IN THE UPPER 80S TO LOW 90S.  
 
KEY MESSAGE 2...HEAT AND HUMIDITY RETURN MIDWEEK. HEAT  
ADVISORIES GO INTO EFFECT TUESDAY MORNING THROUGH WEDNESDAY  
EVENING.  
 
BROAD MID-LEVEL HIGH PRESSURE OVER THE UPPER MIDWEST TUESDAY  
WITH RIDGING EXTENDING ALL THE WAY OUT TO NEW ENGLAND WILL BRING  
A PERIOD OF RISING HEAT THROUGH WEDNESDAY. 850MB TEMPERATURES  
RISE TO NEAR +23C BY TUESDAY EVENING, ALLOWING FOR SURFACE  
TEMPERATURES TO SOAR INTO THE MID 90S ACROSS SOUTHERN NEW  
ENGLAND BOTH TUESDAY AND WEDNESDAY. PROLONGED SOUTHWESTERLY FLOW  
WILL ALSO SURGE DEWPOINTS TO NEAR 70. COMBINED WITH POOR  
OVERNIGHT RELIEF TUESDAY NIGHT WITH LOW TEMPERATURES LIKELY  
REMAINING IN THE MID 70S TO NEAR 80 IN SOME AREAS, HEAT  
ADVISORIES HAVE BEEN ISSUED ACROSS MOST OF SOUTHERN NEW ENGLAND  
(EXCLUDING THE CAPE/ISLANDS AND EASTERN SLOPES OF THE  
BERKSHIRES) FOR TUESDAY MORNING THROUGH WEDNESDAY EVENING. WHILE  
NOT AS INTENSE AS THE PREVIOUS STRETCH OF HOT WEATHER,  
TEMPERATURES OF THIS MAGNITUDE WILL STILL PRESENT SIGNIFICANT  
RISKS FOR THOSE WORKING OR DOING RECREATION OUTDOORS.  
 
KEY MESSAGE 3...PERIODS OF UNSETTLED WEATHER POSSIBLE LATER  
THIS WEEK AS AN UPPER LEVEL TROUGH PUSHES OVER THE REGION.  
 
ENSEMBLE GUIDANCE CONTINUES TO INDICATE AN AMPLIFYING UPPER-  
LEVEL TROUGH ACROSS QUEBEC LATER ON IN THE WEEK, ALLOWING COOLER  
850MB TEMPS AROUND +10C TO +13C TO PREVAIL. THIS WILL HELP COOL  
SURFACE TEMPERATURE TO THE LOW TO MID 80S BY FRIDAY (UPPER 80S  
ACROSS THE CT RIVER VALLEY). SEVERAL WEAK SHORTWAVES PUSHING  
THROUGH WITH THE TROUGH BRING CHANCES FOR PRECIPITATION AND  
UNSETTLED WEATHER BY THE END OF THE WEEK AND INTO THE WEEKEND.  
 
 
   
AVIATION /08Z MONDAY THROUGH FRIDAY/  
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
THROUGH TUESDAY MORNING: HIGH CONFIDENCE.  
 
VFR. INCREASING SOUTHWESTERLY WINDS TODAY, WITH SOME GUSTS NEAR  
20 KTS POSSIBLE THIS AFTERNOON. SCT MID-LEVEL CLOUD DECK LIKELY  
LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. LLWS POSSIBLE FOR  
A FEW HOURS ACROSS THE SE MA TERMINALS, INCLUDING BOS, LATER  
TONIGHT AFTER 00Z. SOUTHWESTERLY WINDS DROP TO 10 KTS OR LESS  
AFTER MIDNIGHT.  
 
KBOS TERMINAL...HIGH CONFIDENCE.  
 
KBDL TERMINAL...HIGH CONFIDENCE.  
 
OUTLOOK /TUESDAY THROUGH FRIDAY/...  
 
TUESDAY: VFR. WINDY WITH AREAS OF GUSTS UP TO 30 KT.  
 
TUESDAY NIGHT: VFR. WINDY WITH LOCAL GUSTS UP TO 30 KT.  
 
WEDNESDAY: VFR. BREEZY.  
 
WEDNESDAY NIGHT: VFR.  
 
THURSDAY THROUGH THURSDAY NIGHT: VFR. BREEZY.  
 
FRIDAY: VFR.  
 
 
   
MARINE  
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
THROUGH TUESDAY...HIGH CONFIDENCE.  
 
HIGH PRESSURE MOVES OFFSHORE LATER TODAY WITH SOUTHWEST WINDS  
INCREASING ACROSS THE COASTAL WATERS. SCA HAVE BEEN ISSUED  
TUESDAY, WITH GUSTY SOUTHWEST WINDS 25-30 KTS ACROSS THE  
SOUTHERN AND EASTERN WATERS. SEAS WILL BE QUITE CHOPPY TUESDAY  
INTO WEDNESDAY MORNING AS WELL, WITH WAVE HEIGHTS 5-8 FT  
POSSIBLE ACROSS THE SOUTHERN OCEAN WATERS AND 3-5 FT ALONG THE  
COASTAL WATERS, INCLUDING VINEYARD AND NANTUCKET SOUNDS.  
 
OUTLOOK /TUESDAY THROUGH FRIDAY/...  
 
TUESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH  
GUSTS UP TO 30 KT. SEAS UP TO 5 FT.  
 
TUESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS  
WITH GUSTS UP TO 30 KT. ROUGH SEAS UP TO 9 FT.  
 
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS  
UP TO 25 KT. AREAS OF ROUGH SEAS.  
 
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS  
APPROACHING 5 FT. SLIGHT CHANCE OF RAIN SHOWERS.  
 
THURSDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.  
 
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT.  
 
 
   
BOX WATCHES/WARNINGS/ADVISORIES  
 
CT...HEAT ADVISORY FROM 11 AM TUESDAY TO 8 PM EDT WEDNESDAY FOR  
CTZ002>004.  
MA...HEAT ADVISORY FROM 11 AM TUESDAY TO 8 PM EDT WEDNESDAY FOR  
MAZ003>007-010>021-026.  
RI...HEAT ADVISORY FROM 11 AM TUESDAY TO 8 PM EDT WEDNESDAY FOR  
RIZ001>007.  
MARINE...SMALL CRAFT ADVISORY FROM 4 PM TO 11 PM EDT TUESDAY FOR ANZ231-  
250.  
SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 11 AM EDT WEDNESDAY  
FOR ANZ232-233-235-237-254>256.  
SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 5 AM EDT WEDNESDAY  
FOR ANZ234.  
 
 
 
 
 
DISCUSSION...MCMINN  
AVIATION...MCMINN  
MARINE...MCMINN  
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