337
FXUS61 KBOX 130543
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
143 AM EDT SAT JUN 13 2026
WHAT HAS CHANGED
THE SLIGHT RISK (LEVEL 2 OF 5) OF SEVERE WEATHER TODAY REMAINS IN
EFFECT FOR FAR WESTERN CT AND MA. THE CHANCE OF SEVERE WEATHER ALSO
REMAINS LOW, BUT NOT ZERO, FOR EASTERN MA/RI.
KEY MESSAGES
- ISOLATED TO SCATTERED STORMS POSSIBLE THROUGH THIS EVENING. A
FEW MAY BE STRONG TO SEVERE.
- ABOVE NORMAL TEMPERATURES CONTINUE THIS WEEKEND, THOUGH
HUMIDITY LEVELS DROP TO MORE COMFORTABLE LEVELS.
- SHOWERS AND THUNDERSTORMS SUNDAY EVENING/OVERNIGHT, BUT THE
RISK FOR SEVERE WEATHER IS LOW.
- RETURN TO MORE SEASONABLE TEMPERATURES AND LOWER HUMIDITY
LEVELS FOR THE EARLY TO MIDDLE PART OF NEXT WEEK, THEN TURNING
MORE ACTIVE AGAIN INTO THURSDAY.
DISCUSSION
KEY MESSAGE 1...ISOLATED TO SCATTERED STORMS POSSIBLE THROUGH
THIS EVENING. A FEW MAY BE STRONG TO SEVERE.
UNDER A MOIST AND UNSTABLE AIRMASS, A MID-LEVEL SHORTWAVE TROUGH
MOVES OVER QUEBEC HELPING TRIGGER SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AND EVENING. NO MAJOR CHANGES FROM THE PREVIOUS FORECAST.
MODEST SHEAR PAIRED WITH THE DAYTIME HEATING HELPING BUILD
INSTABILITY (MLCAPE 1000-2000 J/KG). RECENT RUNS OF HIGH-RES
GUIDANCE HAVE SHOWN A RANGE OF ISOLATED TO SCATTERED STORMS.
SOME OF THE CAMS CONTINUE TO SHOW A FEW STORMS FIRING OFF A SEA
BREEZE BOUNDARY IN EAST SOUTHERN NEW ENGLAND. THERE IS ALSO A
GENERAL CONSENSUS ACROSS GUIDANCE FOR STORMS TO DEVELOP IN
WESTERN MA/CT AHEAD OF THE COLD FRONT EARLY THIS EVENING, MOVING
EASTWARD. CAN'T RULE OUT A STRONG TO SEVERE STORM OR TWO WITH
THE GREATER RISK IN WEST AND CENTRAL PORTIONS OF SOUTHERN NEW
ENGLAND. GUSTY, LOCALLY DAMAGING WINDS AND LIGHTNING ARE THE
MAIN HAZARDS. BRIEF DOWNPOURS ARE ALSO POSSIBLE WITHIN ANY
STORMS. ANY REMAINING SHOWERS OR STORMS PUSH OFFSHORE BY
MIDNIGHT.
KEY MESSAGE 2...ABOVE NORMAL TEMPERATURES CONTINUE THIS WEEKEND,
THOUGH HUMIDITY LEVELS DROP TO MORE COMFORTABLE LEVELS.
AN ANOMALOUSLY WARM AIRMASS REMAINS OVER THE REGION THIS WEEKEND
WITH RIDGING ALOFT. THIS WILL SUPPORT ABOVE NORMALS HIGHS WELL INTO
THE 80S WITH SOME LOW 90S. DESPITE THE SIMILAR TEMPERATURE READINGS
FROM THE LAST FEW DAYS, IT WON'T FEEL AS SWELTERING AS IT HAS BEEN
SATURDAY. DEWPOINTS STAY IN THE MID TO UPPER 50S WHICH WILL TAKE OUT
THE HUMIDITY FACTOR AND PROVIDE SOME MARGINAL RELIEF. WITH RIDGING
ALOFT, CONDITIONS STAY DRY FOR SATURDAY AND A GOOD PORTION OF
SUNDAY. NEXT CHANCE FOR SHOWERS/STORMS RETURNS LATER SUNDAY WITH
MOISTURE/HUMIDITY INCREASING LATER IN THE DAY. MORE ON THAT IN THE
NEXT KEY MESSAGE BELOW.
KEY MESSAGE 3...SHOWERS AND THUNDERSTORMS SUNDAY EVENING/OVERNIGHT,
BUT THE RISK FOR SEVERE WEATHER IS LOW.
AFTER ANOTHER VERY WARM TO HOT SUNDAY, A COLD FRONT WILL BE
PROGRESSING INTO AND THROUGH SOUTHERN NEW ENGLAND SUNDAY NIGHT,
WHICH WILL INCREASE THE RISK FOR SHOWERS AND THUNDERSTORMS. MIDLEVEL
FLOW ALOFT INCREASES AND SUPPORTS INCREASING DEEP-LAYER SHEAR
MAGNITUDES OF AROUND 35 TO 40 KT. HOWEVER IT STILL LOOKS LIKE
INSTABILITY LOOKS ON THE LOW SIDE, BOTH DUE TO THE TIME OF DAY POST-
SUNDOWN AND LOWER DEWPOINTS, WHICH IS A SIGNIFICANT LIMITING FACTOR
TO HOW STRONG ANY STORMS MAY GET. BOTH CSU AND NSSL MACHINE-LEARNING
PROGS INDICATE LOW (< 10%) PROBS OF SEVERE WEATHER FOR SUNDAY NIGHT.
STILL EXPECT SOME THUNDERSTORMS TO DEVELOP/MOVE EASTWARD INTO THE
NIGHT BUT THE RISK THEY PRODUCE SEVERE WEATHER SEEMS LOW. EVEN HOW
MUCH RAINFALL WE GET FROM THESE STORMS IS UNCERTAIN, DESPITE
ELEVATED PWATS IN THE 1.5-1.8" RANGE, AS SOME OF THE GLOBAL MODELS
(GFS/CANADIAN) SIMULATE A CONVECTIVELY-DRIVEN SUBSYNOPTIC LOW OVER
THE MID-ATLANTIC STATES WHICH MOVES WELL OFFSHORE OF SOUTHERN NEW
ENGLAND INTO THE OVERNIGHT. WERE THIS TO DEVELOP, IT COULD GREATLY
REDUCE HOW MUCH RAINFALL WE DO GET. OTHERS, SUCH AS THE ECMWF/ITS
ENSEMBLE MEAN, GENERATE ABOUT A QUARTER TO HALF INCH OF RAIN
AREAWIDE. INCREASED POPS INTO THE CATEGORICAL RANGE BETWEEN THE
02- 10Z TIMEFRAME FROM WEST TO EAST BEFORE DRYING OUT AS COLD
FRONT MOVES THROUGH.
KEY MESSAGE 4...RETURN TO MORE SEASONABLE TEMPERATURES AND LOWER
HUMIDITY LEVELS FOR THE EARLY TO MIDDLE PART OF NEXT WEEK,
THEN TURNING MORE ACTIVE AGAIN INTO THURSDAY.
A COOLER AND MUCH DRIER AIRMASS THEN WORKS INTO SOUTHERN NEW ENGLAND
MONDAY INTO TUESDAY. LATEST GUIDANCE SHOWS 850 MB TEMPS NOW DROPPING
TO AROUND +8 TO +10C, SOME 5 DEGREES C LOWER THAN TODAY. HIGHS MORE
INTO THE 70S TO LOW 80S WITH DEWPOINTS PLUMMETING INTO THE MID
40S TO MID 50S, SO ALSO SUBSTANTIALLY LESS HUMID COMPARED TO
PRIOR DAYS WITH FULL SUNSHINE. EARLY NEXT WEEK LOOKS LIKE A
GREAT STRETCH OF SUMMER WEATHER; TEMPERATURES DO START TO WARM
UP AGAIN AS WE MOVE INTO WEDNESDAY BUT ARE STILL SEASONABLE IN
THE LOW TO MID 80S WITH STILL TOLERABLE HUMIDITY LEVELS.
MORE ACTIVE WEATHER LOOKS TO DEVELOP AROUND THURSDAY OR THURSDAY
NIGHT, AS A STRONGER DISTURBANCE ALOFT MOVES IN AND SWEEPS A COLD
FRONT THROUGH SOUTHERN NEW ENGLAND. THIS COULD BRING A BETTER SHOT
AT SHOWERS/STORMS, ALTHOUGH IT'S STILL TOO EARLY FOR SPECIFICS AT
THIS TIMEFRAME.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE:
THROUGH SUNDAY MORNING: HIGH CONFIDENCE.
VFR THROUGH THE PERIOD. NW WINDS AROUND 8-12 KTS, BUT SHIFT TO
W AROUND 5-10 KT AFTER 22Z. NOT EXPECTING ANY SEABREEZES TODAY.
WINDS SHIFT SW LATE TONIGHT/EARLY SUNDAY MORNING.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
SHRA, CHANCE TSRA.
MONDAY: VFR. BREEZY.
MONDAY NIGHT: VFR.
TUESDAY: VFR. BREEZY.
TUESDAY NIGHT: VFR.
WEDNESDAY: VFR. SLIGHT CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH SUNDAY MORNING...HIGH CONFIDENCE.
SEAS GENERALLY 1-3 FT, EXCEPT 3-4 FT ACROSS THE FAR OUTER
WATERS THROUGH SUNDAY MORNING. OTHERWISE, WINDS REMAIN BELOW SCA
LEVELS.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. AREAS OF SEAS APPROACHING 5 FT. RAIN
SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
MONDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN SHOWERS.
MONDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
TUESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
TUESDAY NIGHT: WINDS LESS THAN 25 KT.
WEDNESDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...MCMINN
AVIATION...MCMINN
MARINE...MCMINN
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