602  
FXUS61 KBOX 271044  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOSTON/NORTON MA  
644 AM EDT SAT APR 27 2024  
   
SYNOPSIS
 
 
QUIET WEATHER PREVAILS SATURDAY, INCREASING CLOUDS THIS  
AFTERNOON AHEAD OF A WARM FRONT, WITH SCATTERED RAIN LATE  
TONIGHT AND TOMORROW. UNSETTLED PATTERN SETS UP FOR SUNDAY INTO  
EARLY NEXT WEEK, THOUGH THE BEST CHANCE FOR SHOWERS IS AROUND  
TUESDAY OR WEDNESDAY AND AGAIN ON FRIDAY. TEMPERATURES TURN  
QUITE MILD FOR INTERIOR WESTERN NEW ENGLAND MONDAY, BUT A  
BACKDOOR COLD FRONT BRINGS COLDER AIR TO COASTAL AREAS. ONSHORE  
FLOW KEEPS TEMPS COOLER TUE/WED BEFORE WARMING AGAIN LATE WEEK.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
HIGHLIGHTS:  
 
* FROST ADVISORY CONTINUES THROUGH 8 AM DUE TO TEMPERATURES IN THE  
LOW 30S. THOUGH, A FEW PRONE LOCATIONS THAT EFFECTIVELY RADIATE  
HAVE DROPPED INTO THE 20S.  
 
PERSISTENT WEATHER PATTERN WITH SURFACE HIGH PRESSURE DOMINATING THE  
FORECAST YET ANOTHER DAY. HARD TO COMPLAIN OVER SEASONABLE AFTERNOON  
TEMPERATURES AND WALL-TO-WALL SUNSHINE. VISUALLY, THE MORE NOTABLE  
DIFFERENCE WILL BE INCREASING HIGH CLOUDS AHEAD OF A WARM FRONT MID  
TO LATE AFTERNOON. FAIRLY COMFORTABLE TEMPERATURE-WISE AS WE WARM  
INTO THE 60S, PERHAPS NEAR 70 DEGREES IN THE CT RIVER VALLEY AND  
MERRIMACK VALLEY. AREAS ALONG THE COAST REMAIN COOLER, HERE THE HIGH  
REACHES THE MIDDLE AND UPPER 50S DUE TO THE SEABREEZE. AT THE COAST  
WIND SPEEDS ARE ROUGHLY 10 TO 15 MPH, INLAND WINDS ARE LIGHT AND  
FROM THE SOUTHWEST.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/
 
 
HIGHLIGHTS:  
 
* SCT'D RAIN, MAINLY WESTERN AREAS, AS A WARM FRONT LIFTS ACROSS  
SOUTHERN NEW ENGLAND.  
 
* NO WASHOUT SUNDAY, BUT A ROUGE SHOWER OR TWO ARE POSSIBLE. MORE  
CLOUDS THAN SUNSHINE, THOUGH TEMPERATURES REMAIN MILD.  
 
TONIGHT:  
 
AS WE TRANSITION FROM LATE AFTERNOON TO EARLY EVENING CLOUDS THICKEN  
AND LOWER AHEAD OF A WARM FRONT THAT BRINGS SCT'D RAIN CHANCES TO  
SOUTHERN NEW ENGLAND DURING THE OVERNIGHT HOURS. THINK THE GREATEST  
CHANCE FOR RAIN ARE WESTERN MASSACHUSETTS AND CONNECTICUT. RAIN WILL  
BE LIGHT DUE TO THE AMOUNT OF DRY AIR STILL AT THE SURFACE BECAUSE  
OF THE PERSISTENT SURFACE HIGH PRESSURE SYSTEM SITUATED OVER THE  
REGION. IN FACT, AREAS EAST OF THE I-95 CORRIDOR MAY REMAIN DRY AND  
NOT SEE A DROP OF RAIN. GIVEN THE CLOUDY CONDITIONS AND SOUTHWEST  
FLOW THE TEMPERATURES OVERNIGHT WILL REMAIN WARM, COMPARATIVELY TO  
THE PREVIOUS FEW NIGHTS - OVERNIGHT TEMPERATURES RANGE FROM THE LOW  
TO MIDDLE 40S.  
 
SUNDAY:  
 
WARM FRONT LIFTS THROUGH AND WE ARE LEFT WITH VARIABLE CLOUD COVER,  
STILL CAN NOT RULE OUT A SPOT/BRIEF SHOWER AS SOUTHERN NEW ENGLAND  
IS SITUATED ON THE NORTHEASTERN EDGE OF THE MID-LEVEL RIDGE. A FEW  
PULSES OF MID-LEVEL ENERGY TRAVERSE THROUGH DURING THE AFTERNOON, IT  
IS FROM THIS WE MAINTAINED A SLIGHT CHANCE FOR LIGHT RAIN - DO NOT  
GO CANCELING YOUR OUTDOOR PLANS. DESPITE THE LACK OF FULL SUNSHINE A  
WARMER AFTERNOON IS LIKELY WITH HIGHS AWAY FROM THE COAST IN THE  
UPPER 60S TO LOW 70S. SOUTHWEST WILL PROVIDE AN ONSHORE WIND FOR THE  
SOUTH COAST OF RI AND MA, HERE IT IS COOLER, UPPER 50S TO LOW 60S.  
 

 
   
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
 
 
KEY POINTS...  
 
* PERIODIC RAIN CHANCES THROUGH THE WEEK, FIRST TUE/WED THEN AGAIN  
ON FRIDAY.  
 
* AFTER A WARM START TO THE WEEK (MORESO FOR WESTERN SNE) TEMPS COOL  
TUE/WED BEFORE WARMING BACK UP LATE WEEK.  
 
DETAILS...  
 
SOUTHERN NEW ENGLAND WILL ALTERNATE BETWEEN BEING ON THE NORTHERN  
PERIPHERY OF A MID LEVEL RIDGE AND BENEATH A SERIES OF PASSING  
SHORTWAVE TROUGHS WHICH WILL BRING PERIODIC RAIN CHANCES TO THE  
REGION WITH A FLUCTUATING TEMPERATURE FORECAST.  
 
MONDAY...  
 
DESPITE MID LEVEL RIDGING OVERHEAD A SURFACE LOW DROPPING FROM  
NORTHERN NEW ENGLAND ALONG WITH SUBTLE IMPULSES AROUND THE TOP OF  
THE RIDGE WILL BRING WIDELY SCATTERED SHOWERS TO THE REGION, THOUGH  
MOST WILL STAY DRY. THE BIGGEST FORECAST CHALLENGE IS THE HIGH  
TEMPERATURE FOR THE DAY AS, DESPITE A VERY WARM AIRMASS TRYING TO  
MOVE NORTH, THE DROPPING LOW WILL DELIVER A BACK DOOR COLD FRONT  
SOMETIME MONDAY. GUIDANCE IS SLOWING THE ARRIVAL OF THE FRONT WHICH  
WOULD ALLOW MORE WARMING TO NEAR OR ABOVE 70F EVEN FOR PORTIONS OF  
CENTRAL/EASTERN MA (AWAY FROM THE IMMEDIATE COAST). ENSEMBLE  
GUIDANCE INDICATES A 90%+ CHANCE OF TEMPS OVER 70F IN WESTERN MA/CT  
AND EVEN A 70-80% CHANCE AS FAR EAST AS RI. ALONG THE EAST COAST  
TEMPS LIKELY DON'T BREAK OUT OF THE 60S (OR EVEN 50S ON THE OUTER  
CAPE).  
 
TUESDAY AND WEDNESDAY...  
 
THE FIRST SHORTWAVE OF THE WEEK MOVES THROUGH TUESDAY WITH A WEAK  
SURFACE REFLECTION. THIS LEADS TO INCREASING RAINFALL CHANCES  
TUESDAY INTO WEDNESDAY. THOUGH A FEW RUMBLES OF THUNDER ARE  
POSSIBLE, THINGS HAVE SLOWED DOWN A BIT WHICH WOULD KEEP THE BETTER  
INSTABILITY TO OUR WEST AND LIMIT THUNDERSTORMS HERE IF IT LOOSES  
THE HELP FROM DAYTIME HEATING. DETAILS ON EXACT TIMING AND PLACEMENT  
OF RAIN SHOWERS ARE UNCLEAR AT THIS TIME, BUT THE TEMPERATURE  
FORECAST IS MORE CERTAIN; ONSHORE FLOW SHOULD KEEP TEMPERATURES IN  
THE 50S (EAST) AND 60S (WEST).  
 
THURSDAY AND FRIDAY...  
 
BRIEF MID LEVEL RIDGING ON THURSDAY WILL BRING DRIER WEATHER AND  
DECREASING CLOUDS ALONG WITH REBOUNDING TEMPERATURES AS SW FLOW  
RETURNS. ANOTHER FRONTAL SYSTEM FROM THE OHIO VALLEY THEN APPROACHES  
ON FRIDAY BRINGING RAIN BACK INTO THE FORECAST. WARMER AIR SURGING  
NORTH AHEAD OF THIS SYSTEM BRINGS HIGHS BACK INTO THE LOW 70S.  
 

 
   
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
 
 
FORECAST CONFIDENCE LEVELS:  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
TODAY... HIGH CONFIDENCE.  
 
VFR. INCREASING CANOPY OF HIGH CLOUDS LATE. LIGHT SW WINDS INCREASE  
THRU THE DAY TO AROUND 7-10 KT; THOUGH SEA-BREEZES AGAIN DEVELOP  
NEAR THE COASTS BETWEEN 14-16Z.  
 
TONIGHT... HIGH CONFIDENCE IN TRENDS THOUGH MODERATE ON EXACT  
TIMING.  
 
CIGS START VFR BUT WILL BE STEADILY LOWERING. BEST CHANCE AT SUB-VFR  
CEILINGS AND LIGHT RAIN SHOWERS IS AFTER 06Z AND MAINLY FROM ORH  
WESTWARD; CIGS COULD BE AS LOW AS IFR BUT THINK MVFR PREDOMINATE FOR  
THOSE INTERIOR WESTERN TERMINALS. STILL THINK WE'RE LOOKING AT OVC  
VFR FOR EASTERN TERMINALS. SW WINDS AROUND 8-12 KT TO START, BUT  
DECREASE TO AROUND 5-8 KT LATE.  
 
SUNDAY... HIGH CONFIDENCE.  
 
MVFR/IFR CIGS EARLY IN THE MORNING WITH SCT'D -SHRA. IMPROVING CIGS  
AFTER 16Z, TRENDING VFR SOME TIME AFTER 18Z/20Z. SW WINDS 8-12 KT.  
 
KBOS TAF...HIGH CONFIDENCE IN TAF. VFR. WINDS ARE LIGHT SOUTHERLY  
THROUGH 12Z. SEABREEZES AGAIN LIKELY, FOLLOWING SIMILAR 14-16Z  
TIMEFRAME AS PRIOR DAYS.  
 
KBDL TAF...HIGH CONFIDENCE IN TAF. VFR. LIGHT SOUTH WIND MOST OF  
TODAY AROUND 4-7 KT AND THROUGH TONIGHT. CIGS LOWER TO MVFR AFTER  
04Z/06Z SUNDAY WITH SCT'D -SHRA.  
 
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...  
 
SUNDAY NIGHT: VFR. SLIGHT CHANCE RA.  
 
MONDAY THROUGH MONDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR  
POSSIBLE. SLIGHT CHANCE RA.  
 
TUESDAY: MAINLY VFR, WITH AREAS MVFR POSSIBLE. CHANCE RA.  
 
TUESDAY NIGHT: MAINLY VFR, WITH AREAS IFR POSSIBLE. CHANCE RA.  
 
WEDNESDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE.  
 

 
   
MARINE
 
 
FORECASTER CONFIDENCE LEVELS:  
 
LOW - LESS THAN 30 PERCENT.  
MEDIUM - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
TODAY THROUGH SUNDAY... HIGH CONFIDENCE.  
 
TRANQUIL BOATING CONDITIONS FOR MARINERS THROUGH MOST OF TODAY AND  
THIS EVENING, THERE IS A LOW CHANCE FOR SHOWERS ON THE SOUTHERN  
WATERS LATE TONIGHT INTO PRE-DAWN SUNDAY.  
 
SOUTHWEST WINDS INCREASE TO 10 TO 15 KNOTS ON ALL WATERS TODAY AND  
SUNDAY, THOUGH WILL BECOME EAST/SOUTHEAST ON THE EASTERN NEARSHORE  
WATERS LATE THIS MORNING TO EARLY EVENING.  
 
SEAS MAINLY 3FT OR LESS ALL WATERS.  
 
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...  
 
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN.  
 
MONDAY: WINDS LESS THAN 25 KT.  
 
MONDAY NIGHT THROUGH TUESDAY: WINDS LESS THAN 25 KT. SLIGHT  
CHANCE OF RAIN.  
 
TUESDAY NIGHT: WINDS LESS THAN 25 KT. CHANCE OF RAIN.  
 
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING  
5 FT. SLIGHT CHANCE OF RAIN.  
 

 
   
BOX WATCHES/WARNINGS/ADVISORIES
 
 
CT...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR CTZ002>004.  
MA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MAZ007-014-  
017>024.  
RI...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR RIZ001>007.  
MARINE...NONE.  
 

 
 

 
 
SYNOPSIS...BW/DOOLEY  
NEAR TERM...BW/DOOLEY  
SHORT TERM...DOOLEY  
LONG TERM...BW  
AVIATION...BW/DOOLEY  
MARINE...BW/DOOLEY  
 
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