145  
FXUS61 KBOX 141743  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
143 PM EDT SUN AUG 14 2022  
   
SYNOPSIS
 
 
ANOTHER SPECTACULAR LATE SUMMER DAY IS IN STORE TODAY WITH  
PLENTIFUL SUNSHINE AND COMFORTABLE HUMIDITY. HIGH PRESSURE MOVES  
OFFSHORE ON MONDAY WITH COOL ONSHORE FLOW DEVELOPING BUT MOSTLY  
DRY WEATHER SHOULD PREVAIL. A COASTAL LOW PRESSURE COULD BRING  
PERIODS OF RAIN LATER TUESDAY INTO THURSDAY BUT THIS IS NOT SET  
IN STONE AND WILL DEPEND ON THE TRACK OF THE STORM SYSTEM. WHILE  
COOLER THAN NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE  
WEEK, TEMPERATURES AND HUMIDITY LEVELS RISE FRIDAY INTO THE  
WEEKEND, WITH LIMITED CHANCES FOR POP-UP SHOWERS OR STORMS.  
 

 
   
NEAR TERM /UNTIL 8 PM THIS EVENING/
 
 
145 PM UPDATE:  
 
SHORT WAVE RIDGING AND ASSOCIATED WEAK HIGH PRESSURE PROVIDING  
BEAUTIFUL SUMMER WEATHER ACROSS THE REGION, WITH TEMPS 75-80 AT  
1 PM, ALONG WITH DEW PTS IN THE 40S AND 50S. LIGHT AND VARIABLE  
WINDS, EXCEPT SEABREEZES DEVELOPING ALONG THE COAST, COMBINED  
WITH SCATTERED DECORATIVE HIGH BASED (6-7 KFT) STRATO-CU CLOUDS.  
ENJOY!  
 

 
   
SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/
 
 
TONIGHT...  
 
IT WILL NOT BE NEARLY AS COOL AS THE PREVIOUS NIGHT DUE TO MORE  
WIDESPREAD CLOUD COVER BUT WITH DEW POINTS IN THE 50S, OVERNIGHT  
LOWS WILL BE FAIRLY COMFORTABLE RANGING FROM THE UPPER 50S TO MID  
60S.  
 
MONDAY...  
 
A HIGHLY ANOMALOUS H5 TROUGH WILL DIG EVEN DEEPER INTO THE MID  
ATLANTIC STATES PER THE EC AND GFS ENSEMBLE GUIDANCE. WITH ANOMALOUS  
RIDGING DEVELOPING EAST OF NEWFOUNDLAND AND LABRADOR, THIS WILL HELP  
INDUCE A SURFACE PRESSURE GRADIENT FROM NORTHEAST TO SOUTHWEST. LONG  
STORY SHORT, EASTERLY TO NORTHEASTERLY ONSHORE FLOW WILL BE THE MAIN  
STORY FOR MONDAY. HIGH PRESSURE MOVES OFFSHORE DURING THE DAY,  
ALLOWING FOR A DISTANT LOW PRESSURE SYSTEM TO BEGIN ITS VOYAGE UP  
THE ATLANTIC SEABOARD. MORE DETAILS IN THE LONG TERM SECTION  
REGARDING ITS POTENTIAL EVOLUTION OVER THE COURSE OF THE WORK WEEK.  
MORE CLOUDS THAN SUN BUT REMAINING MOSTLY DRY, ALTHOUGH A FEW  
SHOWERS COULD NOT BE RULED OUT, ESPECIALLY ACROSS THE WORCESTER  
HILLS AND EAST SLOPES DUE TO UPSLOPE EFFECT. EAST WINDS WILL KEEP  
EASTERN MA COAST COOLER THAN FURTHER INLAND. STILL QUITE PLEASANT  
WITH TEMPS JUST BELOW TO NEAR NORMAL. HIGHS UPPER 70S TO MID 80S.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
 
 
HIGHLIGHTS:  
 
* MONITORING TRACK OF A COASTAL LOW TUES - THURS THAT COULD BRING  
CLOUDS AND WET WEATHER WED-THU, BUT THIS IS NOT SET IN STONE WITH  
CONSIDERABLE UNCERTAINTY ON THE TRACK. TEMPS COOLER THAN NORMAL  
TUE-THURS.  
 
* TURNS WARMER AND MORE HUMID LATE WEEK INTO THE WEEKEND, WITH  
LIMITED CHANCES FOR POP-UP SHOWERS/T-STORMS.  
 
DETAILS:  
 
MONDAY NIGHT THROUGH THURSDAY NIGHT:  
 
SPEAKING BROADLY, THE LARGE-SCALE PICTURE REMAINS LITTLE CHANGED  
FROM PRIOR FORECASTS, WITH AN ANOMALOUS UPPER TROUGH/CLOSED LOW OVER  
OR JUST WEST OF SNE. SHORTWAVE ENERGY ROUNDING THE LONGWAVE TROUGH  
INTO THE COASTAL MID-ATLANTIC LOOKS TO INDUCE WEAK CYCLOGENESIS OVER  
OR IN THE VICINITY OF 40N/70W AROUND TUES, WITH THIS LOW MOVING OVER  
OR OFFSHORE OF SNE IN THE WED TO EARLY THURS TIMEFRAME. NOTICE THERE  
ARE A LOT OF "OR" QUALIFIERS IN THAT LAST SENTENCE; GIVEN A RATHER  
COMPLEX MID-LEVEL PATTERN, UNFORTUNATELY SIGNIFICANT DETAIL  
DIFFERENCES EXIST WHICH RESULT IN OUTCOMES RANGING FROM A COASTAL  
LOW PASSING CLOSE TO SNE BRINGING BREEZY ONSHORE WINDS AND WELCOMED  
SIGNIFICANT RAINS TO THE AREA, OR PASSING FAR ENOUGH OFFSHORE TO  
MAINTAIN DRY WEATHER. OBVIOUSLY QUITE A DIFFERENCE IN OUTCOMES AND  
NOTED SUBSTANTIAL RUN-TO-RUN VARIATION NOTED IN THE DETERMINISTIC  
SOLUTIONS. WHILE THE 12Z GFS WAS A STRONG AND WESTERN OUTLIER, THE  
00Z/14TH GFS CAME IN WEAKER AND COURSE-CORRECTED EAST A BIT CLOSER  
TO NANTUCKET AND THE EASTERN MA COAST; THE 12Z/13TH ECMWF ON THE  
OTHER HAND WAS FAIRLY CLOSE TO THE 12Z/13TH GFS, BUT IT'S 00Z/14TH  
SOLUTION ALSO ADJUSTED EASTWARD BY A SIGNIFICANT MARGIN, LEADING TO  
DRY WEATHER WITH A COASTAL LOW IMPACTING NOVA SCOTIA. THE 00Z/14TH  
CANADIAN GEM IS SOMETHING OF A MIDDLE ROAD BETWEEN THE GFS AND THE  
ECMWF.  
 
GEFS/EPS ENSEMBLE MEMBER LOWS SHOW CONSIDERABLE LONGITUDINAL  
SPREAD/LACK OF CLUSTERING AS THE CYCLONE NEARS OUR SOUTHERN WATERS;  
WITH MEMBER LOWS PAINTED FROM JUST SOUTH OF LONG ISLAND TO THE  
WATERS SOUTH OF NOVA SCOTIA. THE ENSEMBLE MEAN LOW TRACK HAVE SHOWN  
AN EASTWARD TENDENCY. THUS, OVERALL A LOWER-CONFIDENCE OUTLOOK, BUT  
THERE IS SOME INDICATION THAT EARLY MORNING WED TO EARLY THURS LOOKS  
TO FEATURE DECENT PROBABILITIES FOR WET WEATHER FOR RI AND EASTERN  
MA, AND LESS OF A CHANCE FURTHER IN THE INTERIOR.  
 
WILL CONTINUE TO TAKE AN ENSEMBLE-MEAN APPROACH FOR THE FORECAST.  
ANTICIPATE MAINLY DRY WEATHER TUES, WITH AN INCREASING TREND IN RAIN  
CHANCES AFTER MIDNIGHT AND ESPECIALLY WED TO AROUND 35-50%, HIGHEST  
NEAR THE EASTERN COAST AND LESS FURTHER IN THE INTERIOR. CYCLONE  
SHOULD PULL AWAY INTO THURS WITH POP GOING TO SUB-MENTIONABLE LEVELS  
FROM S TO N. EPS/GEFS ENSEMBLE QPF PROBS IN A 24 HR PERIOD BETWEEN  
12Z WED TO 12Z THURS ARE FAIRLY SOLID (50-70%) FOR 0.1 INCHES OR  
GREATER RAINS, LOWER FOR 0.5 INCHES OR GREATER (20-40%) RAINS, AND  
ARE VERY LOW TO NIL (0-20%) FOR 1 INCH OR GREATER RAINS.  
 
PROBABLY WILL HAVE AN ENHANCEMENT TO NE WINDS, ESPECIALLY WED.  
DEPENDING ON THE LOCATION/STRENGTH OF THE CYCLONE AND HOW SLOW IT  
MOVES POLEWARD, COULD HAVE SOME SPLASHOVER OR VERY MINOR COASTAL  
FLOODING ALONG THE EASTERN MA COAST GIVEN NE/ENE WINDS OVER SEVERAL  
TIDE CYCLES AND A BUILDING FETCH RAISING OFFSHORE SEAS. A SOLUTION  
LIKE THE 00Z GFS AND/OR THE PRIOR 12Z ECMWF WOULD FAVOR THIS.  
HOWEVER AT 10-10.5 FT ASTRO TIDES WOULD NEED A 2 TO 2.5 FT SURGE TO  
START CAUSING ISSUES; THUS IS VIEWED AS A LOW PROB OUTCOME AND WILL  
HINGE GREATLY ON THE ABOVE FACTORS WHICH ARE IN NO WAY SET IN STONE.  
 
FRIDAY THROUGH SUNDAY NIGHT:  
 
BERMUDA RIDGE OVER THE WEST-CENTRAL ATLC RETROGRADES TOWARD THE WEST  
WITH INCREASING SW FLOW AND RISING 500 MB HEIGHTS. LOOKS TO BE A  
GENERALLY DRY WEATHER PATTERN, ASIDE FROM DIURNAL SHOWER/T-STORM  
CHANCES. MAY BE SOME BETTER CHANCE/MORE STORM COVG LATER IN THE  
WEEKEND OR MONDAY BUT UNCLEAR WHICH DAY OR DAYS MAY BE MORE FAVORED.  
TEMPERATURES AND HUMIDITY LEVELS TREND BACK TO THOSE MORE TYPICAL OF  
SUMMER, HIGHS INTO THE MID TO UPPER 80S INTERIOR AND COASTAL  
PLAIN/70S-LOW 80S COAST WITH MID-60S DEWPOINTS RETURNING.  
 

 
   
AVIATION /18Z SUNDAY THROUGH FRIDAY/
 
 
FORECASTER CONFIDENCE LEVELS:  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
18Z TAF UPDATE:  
 
TONIGHT/MONDAY & MONDAY NIGHT...  
 
VFR CLOUD BASES, DRY RUNWAYS AND LIGHT ONSHORE WINDS IS THE  
THEME THRU MONDAY NIGHT. SOME NUISANCES INCLUDE - 1) PATCHY FOG  
TONIGHT POSSIBLE FOR NORTHWEST MA, 2) LOW RISK OF AN ISOLATED  
BRIEF SHOWER MONDAY AFTERNOON, ALTHOUGH MOST IF NOT ALL  
TERMINALS REMAIN DRY, 3) INCREASING ONSHORE WINDS LATE MONDAY  
NIGHT WITH LOW CLOUDS AND PATCHY FOG POSSIBLE ALONG THE COAST.  
 
KBOS...HIGH CONFIDENCE IN TAF. SEABREEZE LIKELY AGAIN MONDAY.  
 
KBDL...HIGH CONFIDENCE IN TAF. LOW RISK OF AN ISOLATED BRIEF  
SHOWER MONDAY AFTERNOON. OTHERWISE, DRY RUNWAYS.  
 
OUTLOOK /TUESDAY THROUGH THURSDAY/...  
 
TUESDAY: VFR. BREEZY. SLIGHT CHANCE RA.  
 
TUESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. WINDY WITH  
LOCAL GUSTS UP TO 30 KT. SLIGHT CHANCE RA.  
 
WEDNESDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. WINDY WITH  
LOCAL GUSTS UP TO 30 KT. CHANCE RA.  
 
WEDNESDAY NIGHT: MAINLY VFR, WITH AREAS MVFR POSSIBLE. BREEZY.  
CHANCE RA.  
 
THURSDAY: VFR. BREEZY. SLIGHT CHANCE RA.  
 

 
   
MARINE
 
 
FORECASTER CONFIDENCE LEVELS:  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
145 PM UPDATE...SPECTACULAR BOATING WEATHER THIS  
AFTERNOON/EVENING, WITH LIGHT WINDS, DRY WEATHER, GOOD VSBY AND  
TRANQUIL SEAS. ENJOY! EARLIER DISCUSSION BELOW.  
 
================================================================  
 
THROUGH MONDAY...HIGH CONFIDENCE.  
 
SEAS AND WINDS WILL REMAIN BELOW SCA THRESHOLDS FOR THE FORECAST  
PERIOD. S WINDS TODAY WILL TURN E ON MONDAY. SEAS 1-3 FT.  
 
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...  
 
MONDAY NIGHT: WINDS LESS THAN 25 KT.  
 
TUESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP  
TO 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE OF RAIN.  
 
TUESDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS  
WITH GUSTS UP TO 25 KT. SEAS UP TO 5 FT. CHANCE OF RAIN.  
 
WEDNESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH  
GUSTS UP TO 25 KT. ROUGH SEAS UP TO 9 FT. RAIN LIKELY.  
 
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE  
OF RAIN.  
 
THURSDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE  
OF RAIN.  
 

 
   
BOX WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
MA...NONE.  
RI...NONE.  
MARINE...NONE.  
 

 
 

 
SYNOPSIS...LOCONTO/CHAI  
NEAR TERM...NOCERA/LOCONTO/CHAI  
SHORT TERM...CHAI  
LONG TERM...LOCONTO  
AVIATION...NOCERA/LOCONTO  
MARINE...NOCERA/LOCONTO/CHAI  
 
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