312
FXUS61 KBOX 031129
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
729 AM EDT THU SEP 3 2026
WHAT HAS CHANGED
IN ADDITION TO THE RISK FOR DANGEROUS RIP CURRENTS THIS HOLIDAY
WEEKEND THERE WILL BE A RISK FOR SMALL CRAFT ADVISORY CONDITIONS
ON SUNDAY.
KEY MESSAGES
- ROUNDS OF SHOWERS AND THUNDERSTORMS IMPACT THE REGION TODAY. THE
FIRST ARRIVES THIS MORNING AND THE SECOND ARRIVES LATER IN THE
AFTERNOON.
- MAINLY DRY & VERY PLEASANT FRI INTO EARLY NEXT WEEK EXCEPT FOR
SOME DIURNALLY SCATTERED SHOWERS MAINLY ON SAT. PLEASANT TEMPS TOO
WITH HIGHS IN THE 70S...BUT LOWER-MIDDLE 80S FRI.
- ELEVATED RISK FOR DANGEROUS RIP CURRENTS FOR THE HOLIDAY WEEKEND
ESPECIALLY BY SUN INTO MON.
DISCUSSION
KEY MESSAGE 1... ROUNDS OF SHOWERS AND THUNDERSTORMS IMPACT THE
REGION TODAY. THE FIRST ARRIVES THIS MORNING AND THE SECOND ARRIVES
LATER IN THE AFTERNOON.
IMPACTS FROM A FRONTAL WAVE CONTINUE THROUGH THIS MORNING WITH
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE. ACTIVITY OVERSPREADS
WESTERN PARTS OF OUR CWA BETWEEN 2 AND 3 AM BEFORE IT OVERSPREADS
THE ENTIRE REGION BY DAYBREAK. HEAVY DOWNPOURS ARE LIKELY WITH RICH
MOISTURE IN PLACE. THERE IS A MARGINAL RISK FOR FLASH FLOODING
ACROSS WESTERN MA/CT IN THE SPRINGFIELD/HARTFORD AREAS, BUT THERE IS
NO STRONG SIGNAL FOR ANYTHING OVERLY IMPACTFUL AT THIS TIME.
ELEVATED INSTABILITY WILL SUPPORT SOME RUMBLES OF THUNDER AS SHOWERS
MOVE ACROSS THE REGION, BUT DEEP LAYER SHEAR AND LOW/MID-LEVEL LAPSE
RATES DO NOT APPEAR TO BE FAVORABLE FOR DEEP MOIST CONVECTION
CAPABLE OF PRODUCING STRONG TO SEVERE STORMS.
THE PASSAGE OF THE FRONTAL WAVE BRINGS SIGNIFICANT MID-LEVEL DRYING
WITH 700-500 MB RH VALUES FALLING BELOW 35 PERCENT. THE DRIER
AIRMASS ALOFT WILL RESULT IN CLEARING AND STRONG DIURNAL HEATING.
HIGH TEMPERATURES WILL BE WARMER THAN THEY'VE BEEN OVER THE LAST
SEVERAL DAYS WITH WIDESPREAD READINGS IN THE LOWER TO MID 80S
LIKELY. WARMER TEMPS AND DEW POINTS IN THE UPPER 60S TO LOW 70S
RESULT IN CAPE VALUES CLIMBING TO BETWEEN 1500 AND 2000 J/KG AROUND
THE REGION. STILL, EXPECTING ANY CONVECTION TO BE ISOLATED TO
SCATTERED IN NATURE WITH LOW MID-LEVEL RH VALUES. HIGH-RES GUIDANCE
HAS GENERALLY TRENDED TOWARDS THIS SOLUTION WITH THE NAM SHOWING
ISOLATED CONVECTION. THE HRRR AND RRFS ARE A BIT MORE AGGRESSIVE
AND DEPICT CLUSTERS OF STORMS DEVELOPING AFTER 2 PM. THINK THE
NBM HAS A GOOD HANDLE ON POPS WITH WIDESPREAD VALUES BETWEEN 35
AND 45 PERCENT THROUGHOUT THE CWA. GREATEST CHANCE FOR ANY STORM
ACTIVITY WILL BE ALONG AND S OF A FRONTAL BOUNDARY AT IT MAKES
ITS WAY SE. GUIDANCE GENERALLY SHOWS THIS BOUNDARY S OF THE MASS
PIKE BY 18Z TOMORROW THUS, THE GREATEST CHANCE OF STORMS WILL
LIKELY BE S OF THE MASS PIKE.
KEY MESSAGE 2...MAINLY DRY & VERY PLEASANT FRI INTO EARLY NEXT WEEK
EXCEPT FOR SOME DIURNALLY SCATTERED SHOWERS MAINLY ON SAT. PLEASANT
TEMPS TOO WITH HIGHS IN THE 70S...BUT LOWER-MIDDLE 80S FRI.
UPPER LEVEL SHORTWAVE ENERGY WILL CLOSE OFF OVER THE CANADIAN
MARITIMES OVER THE HOLIDAY WEEKEND. THIS WILL CARVE OUT AN UPPER
TROUGH OVER THE NORTHEAST RESULTING IN PLEASANT WEATHER. MAINLY DRY
WEATHER EXPECTED OVER THE MAJORITY OF THIS TIME. HOWEVER...SOME
NORTHERN STREAM SHORTWAVE ENERGY WILL PROBABLY RESULT IN DIURNALLY
DRIVEN SCATTERED SHOWERS MAINLY ON SAT...BUT CAN NOT RULE OUT A FEW
ON FRI. HIGH PRESSURE BUILDING SOUTHWARD FROM EASTERN CANADA SUN
INTO MON SHOULD BRING AN END TO THIS RISK FOR THE LATTER HALF OF THE
HOLIDAY WEEKEND. HIGHS ON FRI WILL MAINLY BE IN THE LOWER TO MIDDLE
80S...BUT GENERALLY 70S TO NEAR 80 THIS WEEKEND INTO EARLY NEXT
WEEK. IN FACT...COOLEST DAYS WILL BE SAT AND SUN AS THE EASTERN MA
COAST/CAPE AND ISLANDS PROBABLY ONLY SEE HIGHS IN THE UPPER 60S TO
THE LOWER 70S WITH A STIFF NORTHEAST AFTERNOON BREEZE. OVERNIGHT
LOWS MAINLY IN THE 50S TO THE LOWER 60S...BUT THERE MIGHT BE SOME
40S IN THE NORMALLY COOLEST OUTLYING LOCATIONS BY SUN NIGHT/MON AM
AS HIGH PRESSURE BUILDS ACROSS THE REGION.
KEY MESSAGE 3...ELEVATED RISK FOR DANGEROUS RIP CURRENTS FOR THE
HOLIDAY WEEKEND ESPECIALLY BY SUN INTO MON.
GIVEN PERSISTENT NE LOW LEVEL FLOW AND SWELL...WE DO EXPECT AN
ELEVATED RISK FOR DANGEROUS RIP CURRENTS FOR THE HOLIDAY WEEKEND.
THIS IS ESPECIALLY TRUE BY SUN INTO MON ON EAST FACING OCEAN EXPOSED
BEACHES.
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, ESPECIALLY ON TIMING.
MIX OF MVFR-IFR FOR MOST WITH -SHRA AND STRATUS AND MIST,
EXCEPT BKN/OVC VFR OVER THE CAPE AND ISLANDS. GENERAL
DETERIORATION IN MOST AREAS WIDESPREAD MVFR-IFR LEVELS THRU
LATE-MORNING/NOONTIME AS RAIN PULLS OFFSHORE. S WINDS 5-10 KT.
BY AROUND ~17-21Z, SOME INDICATION THAT CEILINGS COULD BEGIN TO
SCATTER TO VFR-ISH RANGE (SCT025/035 AT BEST) IN INTERIOR MA/CT
BUT COULD HOLD ONTO SUB-VFR DECKS LONGER FOR PVD, BOS/BED AND
THE CAPE. POTENTIAL FOR BOS TO SEABREEZE DURING THIS 17-20Z
TIMEFRAME BUT THE EXACT TIMING IS UNCERTAIN. RISK FOR WIDELY SCT
SHRA/TS BETWEEN 20-02Z FROM CENTRAL MA TO THE EASTERN MA COAST,
WHICH WAS LEFT AS VCSH FOR NOW AND WILL REASSESS WITH INCOMING
GUIDANCE. OTHER THAN BOS, SW/W WINDS 5-10 KT THIS AFTERNOON FOR
MOST.
TONIGHT: MODERATE CONFIDENCE.
SHRA/TS MOVES OFFSHORE, WITH BRIEF PERIOD OF VFR EXCEPT MVFR-IFR
HOLDING ON FOR CAPE AND ISLANDS. WINDS TURN N/NE AFTER 03Z IN NE
MA, WHICH COULD BRING RETURN OF MVFR STRATUS FROM THE
WATERS/COASTAL ME/NH. UNCERTAIN ON THE TIMING AND HOW FAR WEST
THE LOW CLOUDS COULD MAKE IT, BUT SEEMS ORH EASTWARD HAS THE
BEST SHOT.
FRIDAY: MODERATE CONFIDENCE.
VFR WEST OF ORH, MVFR-IFR FOR ORH SOUTH AND EAST WITH STRATUS TO
START. SHOULD SEE SCT-BKN VFR/MVFR DECKS WITH MVFR MORE LIKELY
FOR THE CAPE AND ISLANDS REST OF THE DAY. N/NE WINDS 5-10 KT,
DECREASING TO LIGHT AND COULD BE VARIABLE DIRECTIONS BY
AFTERNOON.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. MVFR-IFR WITH -SHRA,
MIST AND FOG THRU AT LEAST 14Z. SHRA THEN ENDS BUT MVFR
CEILINGS HOLD ON AFTER 14Z, WITH POSSIBLE SEABREEZE ~18-21Z. MAY
HAVE TO WATCH FOR POSSIBLE AFTERNOON WIDELY SCATTERED SHRA/TS
BUT UNCERTAIN IF IT DEVELOPS.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. IFR IN FOG AND
STRATUS; SOME INDICATION BY 14-16Z FOR MVFR AND THEN VFR BY
MID-AFTERNOON. S WINDS 5-10 KT, WHICH SHIFT TO LIGHT NORTHERLY
OVERNIGHT.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: VFR. SLIGHT CHANCE SHRA.
FRIDAY NIGHT: VFR.
SATURDAY: VFR. BREEZY. CHANCE SHRA.
SATURDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
SUNDAY: VFR. BREEZY.
SUNDAY NIGHT THROUGH LABOR DAY: VFR.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY THROUGH FRIDAY NIGHT
A FRONTAL WAVE MOVES OVER THE COASTAL WATERS EARLY THIS
MORNING. THIS WILL BE ACCOMPANIED BY HEAVY DOWNPOURS AND
POSSIBLY SOME THUNDER/LIGHTNING. SOME LOCALLY STRONGER WIND
GUSTS TO 20 KNOTS ARE POSSIBLE, BUT OTHERWISE EXPECT MODEST BUT
STEADY SOUTHEAST FLOW AROUND 10 KNOTS WITH GUSTS FROM 15 TO 20
KNOTS POSSIBLE. SEAS STAY AT SUB SCY LEVELS. WINDS SHIFT TO THE
WEST/NORTHWEST TOMORROW AFTERNOON AND CARRY INTO FRIDAY WITH
GENERALLY TRANQUIL CONDITIONS. TRANQUIL CONDITIONS CONTINUE
OVERNIGHT FRIDAY AS HIGH PRESSURE BUILDS IN.
OUTLOOK /FRIDAY THROUGH MONDAY/...
FRIDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN SHOWERS,
PATCHY FOG.
FRIDAY NIGHT: WINDS LESS THAN 25 KT.
SATURDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 30 KT. AREAS OF SEAS APPROACHING 5 FT.
SATURDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. LOCAL ROUGH SEAS.
SUNDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF ROUGH SEAS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS.
LABOR DAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...FT
AVIATION...LOCONTO/FT
MARINE...FT
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