795
FXUS61 KBOX 141118
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
718 AM EDT THU MAY 14 2026
WHAT HAS CHANGED
TIMING OF STEADIER RAIN INTO EASTERN MA AND RI NOW LOOKS MORE
FOCUSED INTO EARLY AFTERNOON, WITH DOWNPOURS DEVELOPING BY MID
TO LATE THIS AFTERNOON.
KEY MESSAGES
- INCREASING CLOUDS WITH RAIN SHOWERS, WITH DOWNPOURS BY THIS
AFTERNOON. OVERCAST, COOL AND WITH MORE INTERMITTENT RAIN OR
DRIZZLE TONIGHT INTO FRIDAY.
- WARMER TEMPERATURES FOR THE WEEKEND INTO NEXT WEEK, WITH
MOSTLY DRY WEATHER.
DISCUSSION
KEY MESSAGE 1...INCREASING CLOUDS WITH RAIN SHOWERS, WITH DOWNPOURS
BY THIS AFTERNOON. OVERCAST, COOL AND WITH MORE INTERMITTENT
RAIN OR DRIZZLE TONIGHT INTO FRIDAY.
500 MB HEIGHT FALLS CONTINUE TO SPREAD ACROSS SOUTHERN NEW ENGLAND
EARLY THIS MORNING, ASSOCIATED WITH A PRONOUNCED UPPER LEVEL LOW IN
VICINITY OF TORONTO, ON. THIS UPPER LEVEL FEATURE WILL BE THE
PRIMARY DRIVER OF OUR WEATHER THROUGH AT LEAST FRIDAY NIGHT, WITH A
PRETTY DREARY, GRAY COUPLE DAYS AHEAD, TO GO ALONG WITH PERIODS OF
MUCH-NEEDED RAIN, WHICH END UP BEING STEADY AND AT TIMES FALLING AT
A MODERATE TO HEAVY CLIP LATER TODAY.
CURRENT RADAR ALREADY SHOWING SOME SPOTTY RAIN SHOWERS IN INTERIOR
SOUTHERN NEW ENGLAND AHEAD OF AN OCCLUDED SFC FRONT. IN EASTERN MA
AND RI, CONDITIONS ARE PARTLY TO MOSTLY CLOUDY BUT GENERALLY DRY. AT
LEAST THROUGH MID TO LATE MORNING, THE GREATEST RISK FOR RAIN WILL
BE MAINLY IN INTERIOR SOUTHERN NEW ENGLAND IN A MOIST SOUTHEAST-
CONVERGENT FLOW. THE EXACT TIMING OF SHOWERS INTO EASTERN MA AND RI
IS STILL UNCERTAIN BUT THE RISK INCREASES BY THIS AFTERNOON AND
ESPECIALLY FROM MID-AFTERNOON ON, AS A RIBBON OF SUBTROPICAL
MOISTURE ADVECTION FROM A DISTANT COASTAL LOW PASSING WELL SOUTHEAST
OF 40N/70W IS DRAWN BACK WESTWARD. PWATS RISE TO AN INCH BY
THAT POINT, WITH WIDESPREAD RAINS AND SOME BRIEF DOWNPOURS
MOVING IN BY LATER TODAY. IT IS WORTH NOTING THAT RECENT HRRR
RUNS HAVE TRIED TO SHOW SHOWERS MOVING INTO EASTERN MA AND RI A
FEW HOURS EARLIER, WHICH ALSO HELPS SPELL OUT THE UNCERTAINTY IN
THE TIMING. I'D STILL ANTICIPATE A NOT-SO-GREAT PM COMMUTE AS
THESE RAINS MOVE IN. ALTHOUGH THERE IS SOME SHALLOW INSTABILITY
AROUND WITH SOME DYNAMIC SUPPORT COULD FAVOR A FEW EMBEDDED
RUMBLES OF THUNDER, THE RISK FOR THUNDERSTORMS OVERALL LOOKS
QUITE LOW. WITH ONSHORE FLOW AND LOTS OF CLOUDS/RAIN AROUND,
KEPT HIGHS IN THE MID 50S TO LOW 60S.
ALTHOUGH STEADIER RAIN TAPERS OFF BY MID TO LATE EVENING, WE'RE LEFT
WITH A MOIST, COOL OVERCAST AS THE UPPER LOW SETTLES OVERHEAD
TONIGHT. WOULDN'T RULE OUT THERE BEING DRIZZLE OR MIST, BUT BETTER
CHANCES FOR LIGHT RAIN IS IN NORTHERN AND NORTHEAST MA.
UNFORTUNATELY FRIDAY ALSO LOOKS PRETTY DREARY TOO, ESSENTIALLY A
CONTINUATION OF ANTICIPATED CONDITIONS FOR THIS EVENING. LOW
TEMPERATURES TONIGHT ONLY FALL INTO THE MID TO UPPER 40S, BUT HIGHS
ON FRIDAY SEEM PRIMED TO NOT GO VERY FAR WITH HARDLY ANY INSOLATION
AND ONSHORE FLOW/COOL ADVECTION WITH READINGS IN THE 50S, COOLEST
EASTERN/COASTAL MA. TOTAL RAINS RANGE FROM A HALF INCH TO INCH FOR
CT-RI-SOUTHEAST MA, BUT ARE AROUND 1 TO 1.5 INCHES NORTH OF THE
PIKE. REALLY, RAINFALL THAT'S MUCH NEEDED.
KEY MESSAGE 2...WARMER TEMPERATURES FOR THE WEEKEND INTO NEXT
WEEK, WITH MOSTLY DRY WEATHER.
SUBSTANTIAL PATTERN CHANGE THEN TAKES HOLD FOR THE WEEKEND AND INTO
NEXT WEEK TOWARD MILDER, SUMMERLIKE TEMPERATURES. WEEKEND STARTS OFF
WITH A FAST, QUASI-ZONAL FLOW WHICH WILL ALLOW FOR ADVECTION OF A
WARM AIRMASS FROM THE CENTER OF THE COUNTRY INTO SOUTHERN NEW
ENGLAND. NBM GUIDANCE OFFERING HIGHS WELL INTO THE 70S TO EVEN SOME
LOW-MID 80S; IT STILL LOOKS QUITE MILD REGARDLESS, THOUGH MULTI-
MODEL GUIDANCE CONSENSUS SHOWS SOME EMBEDDED, DIFFICULT-TO-TIME
RIPPLES IN THE WESTERLY ZONAL FLOW, PERHAPS STEMMING FROM AN
ACTIVE CONVECTIVE PATTERN IN THE MIDWEST. WILL HAVE TO MONITOR
THOSE FOR POSSIBLE CLOUD COVER OR SHOWERS; TOO LOW CONFIDENCE
TO HIT ANY SHOWER/T-STORM THREAT IN THE GRIDS BUT THE RISK IS
NOT ZERO EITHER.
EVEN WARMER TEMPERATURES THEN ARRIVE FOR EARLY TO MID NEXT
WEEK. MONDAY LOOKS TO FEATURE A POTENTIAL BACKDOOR FRONT/COOLER
ONSHORE FLOW WITH EASTERN MA IN THE UPPER 60S TO LOW 70S BUT
WITH MID 80S CT VALLEY. 500 MB HEIGHTS THEN RISE BY TUESDAY AND
BRINGS ANOMALOUSLY WARM 850 MB TEMPS IN THE MID TEENS C RANGE,
WHICH WOULD SUPPORT HIGHS POTENTIALLY WELL INTO THE 80S, WITH
70S SOUTH COAST.
AVIATION /12Z THURSDAY THROUGH MONDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE:
TODAY: MODERATE CONFIDENCE.
THROUGH AT LEAST 18Z, LOWEST CATEGORIES FOR BDL AND ORH WITH
RAIN WITH MVFR CEILINGS AND MVFR VISBY. MAINLY VFR SHOULD GOVERN
THE REST OF THE TAFS THRU THAT TIMEFRAME, OUTSIDE OF A
BRIEF/PASSING -SHRA. THE EXACT TIMING OF RAIN INTO EASTERN MA
AND RI IS UNCERTAIN, BUT THE RISK INCREASES FOR MVFR/IFR
CIGS/VISBY SHRA/+SHRA IN THE 17-20Z TIMEFRAME FOR EASTERN MA AND
RI, MOVING GRADUALLY TO THE N/NE. LOCALLY HEAVY DOWNPOURS COULD
BE POSSIBLE, WITH A LOW/OUTSIDE CHC AT TS.
SE WINDS AROUND 8-12 KT TO START, THEN SLOWLY BACK TO E THRU THE
AFTN, AND COULD BECOME LIGHT NE/N IN THE INTERIOR.
TONIGHT: MODERATE CONFIDENCE.
STEADIER SHRA TAPERS OFF TO AN INTERMITTENT -SHRA OR EVEN -DZ
BY 00-03Z. MVFR/IFR CEILINGS THEN DETERIORATE TO IFR TO LIFR
FOR MOST TAFS. MIST/FOG POSSIBLE TOO WITH IFR VISBYS. COASTAL NE
WINDS 5-10 KT, INTERIOR WINDS N/NW 5 KT OR LESS.
FRIDAY: MODERATE CONFIDENCE.
IFR GENERALLY PREVAILS, THOUGH SOME OPTIMISM FOR MVFR CEILINGS
TOWARD BDL LATE IN THE DAY. PERIODS OF LIGHT -SHRA OR -DZ, WITH
BETTER CHANCE FOR STEADIER LIGHT RAIN FOR EASTERN/COASTAL MA. NE
WINDS BECOME N/NW AROUND 5-10 KT, THOUGH AROUND 10-12 KT FOR
EASTERN MA.
KBOS...MODERATE CONFIDENCE. VFR TO START, SE WINDS DEVELOPING
BY 10Z. OVC VFR (MVFR DECKS LURKING AROUND?) AS SOON AS 15Z, BUT
THINK MVFR CEILINGS STEADIER RAIN MORE LIKELY AFTER 17Z, WITH
IFR- VISBY MODERATE TO HEAVY SHRA BY 20Z WITH WINDS BECOMING
EASTERLY AROUND 10 KT. SHRA ENDS AROUND 02-03Z TO MORE OF A -DZ
BUT CEILINGS THEN GO TO IFR/LIFR LEVELS AS WINDS BECOME NE.
KBDL...MODERATE CONFIDENCE. VFR BECOMING MVFR IN SHRA BY 07-08Z.
SHRA CONTINUES THRU MOST OF THE DAY WITH MVFR CEILINGS; RAIN
TAPERS OFF TO INTERMITTENT SHRA/DZ BY 00Z, BUT CEILINGS THEN GO
TO IFR/LIFR LEVELS.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. SLIGHT CHANCE
SHRA.
FRIDAY NIGHT: VFR.
SATURDAY THROUGH SATURDAY NIGHT: VFR. BREEZY.
SUNDAY: VFR. BREEZY. SLIGHT CHANCE SHRA.
SUNDAY NIGHT THROUGH MONDAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
SE TO E WINDS AROUND 10-15 KT THROUGH TODAY, BUT EASTERLY
SWELL INCREASES WAVE HEIGHTS TO AROUND 4-7 FT TONIGHT AND
CONTINUE INTO FRIDAY. SCAS SEEM LIKELY TO BE NEEDED FOR TONIGHT
INTO FRIDAY AS SEAS INCREASE. ALTHOUGH THE MORNING IS MOSTLY DRY
FOR THE WATERS, RAIN WITH EMBEDDED DOWNPOURS DEVELOP THIS
AFTERNOON, WITH MORE INTERMITTENT SHOWERS, DRIZZLE AND FOG FOR
TONIGHT INTO FRIDAY.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN SHOWERS.
FRIDAY NIGHT THROUGH SATURDAY NIGHT: WINDS LESS THAN 25 KT.
SEAS UP TO 5 FT.
SUNDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT THROUGH MONDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...LOCONTO
AVIATION...LOCONTO/FT
MARINE...LOCONTO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page