971  
FXUS61 KBOX 101927  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
327 PM EDT TUE JUL 10 2018  
   
SYNOPSIS
 
 
ANOTHER HOT AFTERNOON IS ON TAP TODAY AND AN APPROACHING COLD  
FRONT WILL TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS LATE  
TODAY AND TONIGHT. A FEW STRONG STORMS ARE POSSIBLE IN THE  
INTERIOR. TROPICAL STORM CHRIS IS EXPECTED TO INTENSIFY INTO A  
HURRICANE TODAY BUT PASS WELL SOUTHEAST OF NANTUCKET WEDNESDAY.  
HIGH PRESSURE WILL BUILD OVER THE REGION THURSDAY AND FRIDAY  
RESULTING IN MAINLY DRY WEATHER ALONG WITH SEASONABLE  
TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS. A RETURN TO HOT  
WEATHER IS EXPECTED LATER THIS WEEKEND INTO EARLY NEXT WEEK. WHILE A  
FEW THUNDERSTORMS CAN NOT BE RULED OUT THIS WEEKEND INTO EARLY NEXT  
WEEK, DRY WEATHER LOOKS TO DOMINATE THE MAJORITY OF THE TIME.  
 

 
   
NEAR TERM /THROUGH 6AM WEDNESDAY/
 
 
 
TEMPERATURES AT 850MB ARE NEAR 19C AND ARE MIXING DOWN TO THE  
SURFACE WHERE SITES ARE SEEING TEMPS NEAR OR SURPASSING 90F. THE  
APPROACHING COLD FRONT IS CURRENTLY JUST SE OF THE CANADIAN/NEW  
YORK BORDER WHERE A LINE OF CU AND A FEW ISOLATED THUNDERSTORMS  
ARE POPPING UP.  
 
LOOKING AT SEVERAL HI-RES MODELS, THE POTENTIAL FOR ANY STRONG  
TO SEVERE THUNDERSTORMS LOOKS TO BE DIMINISHING ACROSS SNE. DRY  
AIR ALOFT DOESN'T SEEM TO MOVE OUT OF THE REGION UNTIL 00Z AND  
GIVEN THAT CURRENT DEWPOINTS ACROSS THE REGION ARE IN THE LOW  
60S AND MID 50S, SHOWERS AND THUNDERSTORMS WILL HAVE A DIFFICULT  
TIME FORMING WITH THE LACK OF MOISTURE. IN ADDITION, WESTERLY  
WINDS WILL PROVIDE MINIMAL TO NO SURFACE CONVERGENCE. THE BEST  
CHANCE FOR ANY THUNDERSTORMS DEVELOPING WILL BE ON THE EASTERN  
SLOPES OF THE BERKSHIRES AND THE WORCESTER HILLS DUE TO  
UPSLOPING WINDS. HIGHER TERRAIN IS ALSO COLOCATED WITH THE  
STRONGEST SHEAR AND INSTABILITY. THE MAIN TIME FRAME FOR STORMS  
LOOKS TO BE BETWEEN 21Z AND 02Z.  
 
ISOLATED SHOWERS AND THUNDERSTORMS MAY CONTINUE INTO THE  
EVENING, WHEN THE BEST SYNOPTIC FORCING, SHEAR, COOLING TEMPS  
ALOFT, AND INSTABILITY ARRIVE IN SNE. SOME HEAVIER SHOWERS ARE  
POSSIBLE LATE TONIGHT WHERE PWATS OVERNIGHT REACH UP 1.75" AND K  
INDICIES ARE UP TO 38.  
 
TEMPS ARE EXPECTED TO REMAIN IN THE 60S OVERNIGHT, BUT IF  
CLOUDS ASSOCIATED WITH THE COLD FRONT CLEAR OUT BEFORE SUNRISE,  
SOME RADIATIONAL COOLING IS POSSIBLE, ESPECIALLY IN WESTERN MA  
ACROSS THE HIGHER TERRAIN.  
 
ACK MAY SEE A BRIEF PERIOD OF FOG JUST BEFORE SUNRISE TOMORROW  
AS SW WINDS DIMINISH AFTER THE FRONTAL PASSAGE AND AN INVERSION  
REMAINS OVERHEAD.  
 

 
   
SHORT TERM /6AM WEDNESDAY THROUGH WEDNESDAY NIGHT/
 
 
WEDNESDAY...  
 
COLD FRONT WILL BE SITTING JUST EAST OF NANTUCKET COME SUNRISE  
TOMORROW MORNING WITH SOME POSSIBLE LINGERING SHOWERS AND  
THUNDERSTORMS ACROSS RI AND SE MASS.  
 
AS THE FRONT MOVES OFFSHORE AND INSTABILITY ERODES THROUGHOUT  
THE MORNING, ANY LINGERING SHOWERS AND THUNDERSTORMS WILL  
DISSIPATE ACROSS SE NEW ENGLAND.  
 
THERE'S A SMALL CHANCE FOR ISOLATED SHOWERS TOMORROW AFTERNOON  
ACROSS NORTHERN CT AND CENTRAL MA GIVEN CYCLONIC FLOW AND  
COOLING TEMPS ALOFT, BUT THESE WILL LIKELY BE SHORT LIVED WITH  
VERY LITTLE IMPACT.  
 
TROPICAL STORM CHRIS IS EXPECTED TO PASS 300 MILES TO OUR SE,  
RESULTING IN HIGH SURF AND DANGEROUS RIP CURRENTS ALONG SOUTH  
COASTAL BEACHES. HIGH SURF ADVISORIES MAY BE NEEDED.  
 
WEDNESDAY WILL BE MUCH COOLER THAN TODAY AS WINDS OUT OF THE NE  
KEEP THE REGION IN THE MID 70S. THE WARMEST TEMPERATURES ARE  
LIKELY TO BE IN THE CONNECTICUT RIVER VALLEY WHERE HARTFORD MAY  
SEE 80 DEGREES. BEHIND THE COLD FRONT, HUMIDITY WILL DECREASE AS  
DEWPOINTS WILL BE IN THE MID TO UPPER 50S ACROSS THE REGION.  
 
WEDNESDAY NIGHT...  
STRONG NE WINDS AND HIGH SURF WILL CONTINUE INTO THE EVENING  
AS TS CHRIS DEPARTS THE REGION AND CONTINUES MOVING NE. SKIES  
WILL BE MOSTLY CLEAR AS A 1024MB HIGH BUILDS INTO NEW ENGLAND,  
ALLOWING TEMPERATURES TO COOL INTO THE 50S OVERNIGHT.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
HIGHLIGHTS...  
 
* MAINLY DRY THU/FRI WITH SEASONABLE TEMPS AND COMFORTABLE HUMIDITY  
 
* HOT WEATHER RETURNS LATE THIS WEEKEND INTO EARLY NEXT WEEK AND  
WHILE A FEW T-STORMS ARE POSSIBLE DRY WEATHER SHOULD DOMINATE  
 
DETAILS...  
 
THURSDAY AND FRIDAY...  
 
DISTANT TROPICAL SYSTEM CHRIS WELL EAST OF THE BENCHMARK WED EVENING  
WILL RAPIDLY MOVE NORTHEAST AND BE LOCATED EAST OF THE CANADIAN  
MARITIMES BY THU. THIS SHOULD ALLOW LINGERING SOUTHEAST SWELL/RIP  
CURRENT RISK THU TO DIMINISH BY FRI. OTHERWISE...HIGH PRESSURE TO  
OUR NORTH WILL RESULT IN MAINLY DRY WEATHER ALTHOUGH A SPOT SHOWER  
CAN NOT BE RULED OUT THU WITH A MOISTURE STARVED SHORTWAVE.  
SEASONABLE TEMPERATURES WITH COMFORTABLE HUMIDITY LEVELS ON TAP FOR  
THE REGION ON BOTH THU AND FRI.  
 
THIS WEEKEND INTO EARLY NEXT WEEK...  
 
UPPER TROUGH WILL EXIT THE REGION THIS WEEKEND ALLOWING FOR RISING  
HEIGHT FIELDS INTO EARLY NEXT WEEK. THE RESULT WILL BE THE RETURN  
TO HOT AFTERNOONS AT LEAST AWAY FROM ANY MARINE INFLUENCES ON THE  
IMMEDIATE COAST. CERTAINLY THE POTENTIAL FOR A COUPLE DAYS OF 90+  
DEGREE HEAT. SYNOPTIC SCALE FORCING DOES NOT LOOK FAVORABLE FOR  
MUCH PRECIPITATION...BUT CAN NOT RULE OUT A FEW T-STORMS. TIMING OF  
THAT RISK IS HIGHLY UNCERTAIN AND REGARDLESS THE VAST MAJORITY OF  
THIS PERIOD WILL LIKELY FEATURE DRY WEATHER.  
 

 
   
AVIATION /19Z TUESDAY THROUGH SUNDAY/
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.  
 
TONIGHT... SCATTERED SHOWERS/T-STORMS MOVING SOUTH ACROSS SNE.  
MAINLY VFR, BUT BRIEF MVFR-IFR POSSIBLE IN SHOWERS/T-STORMS.  
WINDS SHIFTING TO NORTH. ACK MAY SEE A BRIEF PERIOD OF FOG  
BEFORE SUNRISE AS WINDS WEAKEN OUT OF THE SW AND INVERSION  
REMAINS ALOFT.  
 
WEDNESDAY...  
MAINLY VFR. A FEW MORNING SHOWERS MAY LINGER ACROSS SE NEW ENG  
IN EARLY MORNING.  
 
WEDNESDAY NIGHT...  
MAINLY VFR. STRONG WINDS OUT OF THE NE ACROSS SE NEW ENG.  
 
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. GREATEST RISK FOR A FEW  
THUNDERSTORMS AND/OR SHOWERS IN THE VICINITY OF THE TERMINAL  
AROUND 00Z.  
 
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.  
 
OUTLOOK /THURSDAY THROUGH SATURDAY/...  
 
THURSDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT CHANCE  
SHRA.  
 
THURSDAY NIGHT THROUGH FRIDAY NIGHT: VFR.  
 
SATURDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT CHANCE  
SHRA.  
 

 
   
MARINE
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.  
 
DIMINISHING WINDS TONIGHT WITH WIND SHIFT TO N BEHIND THE COLD  
FRONT. A FEW SHOWERS AND AN ISO STRONG T-STORM OR TWO WITH  
GUSTY WINDS POSSIBLE TONIGHT. NE WINDS 10-20 KT WED AFTERNOON  
ACROSS THE SE COASTS. WITH TS CHRIS OFF TO OUR SE, SEAS MAY  
BUILD UP TO 8 FT POSSIBLE OVER THE SOUTHERN WATERS. A HIGH SURF  
ADVISORY MAY BE NEEDED. WITH STRONG NE WINDS AND BUILDING  
SOUTHERLY SWELL, CHOPPY CONDITIONS ON THE WATERS IS POSSIBLE.  
 
OUTLOOK /THURSDAY THROUGH SATURDAY/...  
 
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING  
5 FT.  
 
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING  
5 FT.  
 
FRIDAY THROUGH FRIDAY NIGHT: WINDS LESS THAN 25 KT.  
 
SATURDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.  
 

 
   
BOX WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ013-  
016>023.  
RI...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR RIZ001>008.  
MARINE...NONE.  
 

 
 

 
SYNOPSIS...KJC/FRANK  
NEAR TERM...NOCERA/CORREIA  
SHORT TERM...NOCERA/CORREIA  
LONG TERM...FRANK  
AVIATION...FRANK/NOCERA/CORREIA  
MARINE...FRANK/NOCERA/CORREIA  
 
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