296  
FXUS61 KBOX 180741  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
341 AM EDT THU SEP 18 2025  
   
SYNOPSIS  
 
SCATTERED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL LIFT  
NORTHWARD ACROSS THE REGION TONIGHT INTO EARLY THURSDAY AS LOW  
PRESSURE TRACKS TO THE SOUTH. DRYING OUT THURSDAY AFTERNOON  
WITH WARM AND DRY CONDITIONS FRIDAY, THEN A COLD FRONT WILL BE  
FOLLOWED BY MORE AUTUMN-LIKE TEMPERATURES THIS WEEKEND. DRY  
WEATHER PATTERN CONTINUES INTO NEXT WEEK WITH A NOTABLE WARMING  
TREND.  
 
 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/  
 
KEY MESSAGES:  
 
* SHOWERS THIS MORNING TAPER OFF IN THE AFTERNOON, GIVING WAY TO A  
DRIER DAY  
 
EARLY MORNING SHOWERS AND STORMS COME TO AN END BY THE LATE  
MORNING HOURS OVER THE EAST COAST. THE SUBTROPICAL LOW PASSING  
TO THE SOUTH MOVES EAST OUT TO SEA THIS MORNING, LEADING TO  
SKIES CLEARING FROM WEST TO EAST THROUGHOUT THE DAY. WINDS WILL  
THEN SHIFT WEST FOR THE AFTERNOON. WITH CLEARING OVER THE  
INTERIOR FIRST AND GOOD MIXING WITH TEMPERATURES AT 925 MB  
AROUND 20C, TEMPERATURES MAY REACH THE LOW 80S THERE. THE CAPE  
AND ISLANDS WILL BE SLIGHTLY COOLER AS CLOUDS LINGER A BIT  
LONGER THERE WITH HIGHS IN THE MID 70S. GENERALLY, A WARM DAY  
AHEAD ACROSS SOUTHERN NEW ENGLAND, WITH SLIGHTLY MUGGY  
CONDITIONS AS DEW POINTS REACH THE 60S IN RI AND EASTERN MA.  
 
 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/  
 
KEY MESSAGES:  
 
* WARM AND DRY CONDITIONS CONTINUE INTO FRIDAY  
 
SKIES CONTINUE TO CLEAR HEADING INTO TONIGHT. AS WEST TO NORTHWEST  
WINDS GO LIGHT ONCE AGAIN AND DEW POINTS REMAIN SLIGHTLY ELEVATED  
OVER MUCH OF SE MA, SOME PATCHY FOG BECOMES A POSSIBILITY TONIGHT.  
MILD TEMPERATURES CONTINUE WITH WARMER AIR ALOFT KEEPING  
TEMPERATURES IN THE 50S AND LOW 60S.  
 
A COLD FRONT MOVES IN FROM THE NORTH FRIDAY, SHIFTING WINDS MORE  
NORTH. DRIER AIR MOVES IN BEHIND IT WITH HIGH PRESSURE BEGINNING TO  
BUILD BEHIND IT AS WELL. THE COLDER AIR FROM THE NORTH IS EXPECTED  
TO LAG BEHIND THE FRONT ITSELF AND WON'T MOVE IN UNTIL TOMORROW  
NIGHT, ALLOWING DAYTIME HIGHS TO STILL REACH THE UPPER 70S IN MOST  
SPOTS, WITH AREAS IN THE CT RIVER VALLEY APPROACHING 80F ONCE  
AGAIN.  
 
 
   
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/  
 
KEY MESSAGES:  
 
* DRIER AND COOLER FRIDAY NIGHT THROUGH THE WEEKEND BEFORE WARMING  
TREND EARLY NEXT WEEK  
 
THE GENERAL TRENDS IN THE LONG TERM FORECAST REMAIN RELATIVELY  
UNCHANGED. WITH THE COLD FRONT HAVING MOVED THROUGH THE REGION  
BY FRIDAY EVENING, THE COLDER AIR BEHIND IT FINALLY MOVES IN FOR  
FRIDAY NIGHT. LOWS WILL DIP INTO THE LOW 40S WITH SOME SPOTS IN  
NW MA POSSIBLY FALLING INTO THE UPPER 30S.  
 
MORE AUTUMN-LIKE WEATHER PREVAILS THROUGH THE WEEKEND AS THE COOLER  
AIRMASS SETTLES IN FROM THE NORTH. HIGH PRESSURE BUILDS IN  
POST-FROPA, DECREASING WINDS AS DEW POINTS FALL INTO THE 30S FOR  
MUCH OF SOUTHERN NEW ENGLAND NORTH OF I-90. EVEN WITH DRIER  
CONDITIONS, THE LACK OF STRONG WINDS SHOULD HELP KEEP FIRE  
WEATHER CONCERNS AT BAY. HIGHS SATURDAY ONLY GET INTO THE UPPER  
60S, EVEN STRUGGLING TO REACH 70F IN THE CT VALLEY AS 925 MB  
TEMPERATURES REMAIN AROUND 10C DURING THE DAY AFTER DIPPING  
BELOW 10C OVERNIGHT. ENSEMBLES INDICATE SATURDAY NIGHT WILL BE  
EVEN MORE FAVORABLE FOR COOLER TEMPERATURES WITH LOWS DIPPING  
INTO THE UPPER 30S FOR SOME SPOTS DUE TO EXPECTED STRONG  
RADIATIONAL COOLING.  
 
TEMPERATURES BEGIN TO RISE SLIGHTLY SUNDAY AS HIGH PRESSURE STARTS  
TO MOVE EAST AND RIDGING ALOFT BUILDS. SOUTHERLY TO SOUTHWESTERLY  
FLOW KICKS IN LATE SUNDAY/EARLY MONDAY INTO TUESDAY AS A RESULT,  
INCREASING TEMPS AND MOISTURE TO START THE WEEK; ENSEMBLES ARE  
ALREADY INDICATING PROBABILITIES AROUND 50 TO 70 PERCENT FOR  
TEMPERATURES OF 80+ BY TUESDAY AFTERNOON AND 925 MB TEMPERATURES  
THEN RETURN TO AROUND 20C. SOME ENSEMBLE GUIDANCE IS HINTING AT THE  
CHANCE FOR SOME SHOWERS FOR WEDNESDAY AS A SHORTWAVE MOVES TOWARDS  
SOUTHERN NEW ENGLAND, BUT DETAILS ON TIMING AND LOCATION REMAIN  
UNCERTAIN AT THIS TIME AS IT IS STILL FAR OUT IN THE FORECAST.  
 
 
   
AVIATION /07Z THURSDAY THROUGH MONDAY/  
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
06Z TAF UPDATE:  
 
THROUGH 12Z...HIGH CONFIDENCE.  
 
MVFR WITH IFR (AND SOME POCKETS OF LIFR) POSSIBLE IN SHRA/TSRA.  
SCATTERED SHOWERS ARE ONGOING OVER MUCH OF SE MA, CAPE COD, AND  
AROUND THE ISLANDS, PLUS SOME MOVING OVER BOS. THIS TREND IS  
EXPECTED TO CONTINUE FOR THE NEXT FEW HOURS. CONVERTED PROB30S  
TO TEMPOS WITH THESE SHOWERS MOVING NORTH.  
 
THURSDAY...HIGH CONFIDENCE IN TRENDS.  
 
MVFR/IFR CEILINGS AND -SHRA EARLY WILL STEADILY IMPROVE TO VFR  
BETWEEN 15-17Z, EXCEPT OVER CAPE COD AND THE ISLANDS WHERE  
IMPROVEMENT MAY BE SLOWER. LIGHT NORTHEAST GRADUALLY SHIFTING  
TO WEST/NORTHWEST TOMORROW AFTERNOON.  
 
THURSDAY NIGHT...HIGH CONFIDENCE.  
 
VFR. LIGHT WEST/SOUTHWEST WINDS FOR THE FIRST HALF OF THE NIGHT  
BECOME NORTHEAST BY 12Z FRIDAY.  
 
FRIDAY...HIGH CONFIDENCE.  
 
VFR. BREEZY NW WINDS AROUND 10 KTS, OCCASIONALLY GUSTING TO 15  
KTS.  
 
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. SHRA ONGOING AND MAY  
LAST THROUGH 10Z. CHANCE FOR IFR REMAINS, THOUGH CONFIDENCE  
IN LIFR HAS LOWERED. REMOVED FROM TAF AT THIS TIME.  
 
BDL TERMINAL...HIGH CONFIDENCE IN TAF.  
 
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...  
 
FRIDAY NIGHT: VFR. BREEZY.  
 
SATURDAY THROUGH MONDAY: VFR.  
 
 
   
MARINE  
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
THROUGH FRIDAY...HIGH CONFIDENCE.  
 
THE CHANCE FOR SOME THUNDERSTORMS REMAINS THROUGH THIS MORNING  
OVER THE WATERS NEAR THE CAPE AND ISLANDS. OTHERWISE, EXPECT  
RELATIVELY QUIET CONDITIONS FOR MID-SEPTEMBER WITH SUSTAINED  
WINDS 10 KNOTS OR LESS AND GUSTS LESS THAN 20 KNOTS. SEAS  
GRADUALLY BECOMING 3 FEET OR LESS BY THURSDAY AFTERNOON.  
 
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...  
 
FRIDAY NIGHT THROUGH SATURDAY: WINDS LESS THAN 25 KT. SEAS  
LOCALLY APPROACHING 5 FT.  
 
SATURDAY NIGHT THROUGH SUNDAY: WINDS LESS THAN 25 KT.  
 
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING  
5 FT.  
 
MONDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.  
 
 
   
BOX WATCHES/WARNINGS/ADVISORIES  
 
CT...NONE.  
MA...NONE.  
RI...NONE.  
MARINE...NONE.  
 
 
 
 
 
SYNOPSIS...KJC/HRENCECIN/RM  
NEAR TERM...HRENCECIN  
SHORT TERM...HRENCECIN  
LONG TERM...HRENCECIN  
AVIATION...HRENCECIN  
MARINE...HRENCECIN  
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