521
FXUS61 KBOX 300025
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
825 PM EDT SAT AUG 29 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
- MORE SUMMER-LIKE CONDITIONS RETURN TOMORROW. RAIN CHANCES
RETURN LATE SUNDAY.
- BACKDOOR COLD FRONTAL BOUNDARY MONDAY BRINGS ONSHORE FLOW,
DECREASED CLOUD COVER AND COOLING AFTERNOON TEMPERATURES.
- UNSETTLED TUESDAY THROUGH THURSDAY WITH SEVERAL OPPORTUNITIES
FOR SHOWERS AND THUNDERSTORMS, WITH A CHANCE FOR SOME TO
BECOME STRONG IN WESTERN MA AND CT. TIMING WHICH DAYS MAY HAVE
BETTER STORM CHANCES IS STILL UNCERTAIN.
DISCUSSION
KEY MESSAGE 1...MORE SUMMER-LIKE CONDITIONS RETURN TOMORROW.
RAIN CHANCES RETURN LATE SUNDAY.
DRY AND SUNNY CONDITIONS WITH SOME DIURNAL CU CONTINUE THROUGH THE
REST OF TODAY. DEW POINTS REMAIN IN THE 40S AND 50S ACROSS THE
REGION THROUGH TONIGHT AS WELL WITH LOWS IN THE 50S AND LOW 60S. 925
MB TEMPERATURES REMAIN GENERALLY AROUND 15C AS WELL BEFORE
INCREASING SLIGHTLY TO AROUND 18-20C TOMORROW WITH HIGH PRESSURE
STARTING TO SHIFT MORE TO THE EAST AND SW WINDS KICKING IN. HIGHS
TOMORROW RETURN TO THE LOW TO MID 80S ALONG WITH SLIGHTLY INCREASED
HUMIDITY.
LATEST GUIDANCE CONTINUED TO INDICATED A WEAK LOW PRESSURE MOVING
CLOSE TO THE REGION, EMPHASIZING CHANCE FOR RAIN GENERALLY SOUTH OF
I-90 SUNDAY NIGHT. IT'S WORTH NOTING, THOUGH, THAT SHOWERS DO REMAIN
POSSIBLE ACROSS ALL OF SOUTHERN NEW ENGLAND STARTING IN THE LATE
EVENING HOURS. THERE'S A LOW CHANCE FOR SOME EMBEDDED THUNDER, BUT
THAT IS GENERALLY RELEGATED TO THE SOUTH COAST AND THE SOUTHERN
WATERS. NOT ANTICIPATING MUCH OF A WASHOUT WITH THESE. HIGHER
CONFIDENCE THAT SHOWERY CONDITIONS CONTINUE OVERNIGHT SUNDAY TOWARDS
THE SOUTH COAST, CLEARING OUT HEADING INTO MONDAY MORNING.
KEY MESSAGE 2...BACKDOOR COLD FRONTAL BOUNDARY MONDAY BRINGS
ONSHORE FLOW, DECREASED CLOUD COVER AND COOLING AFTERNOON
TEMPERATURES.
MONDAY LOOKS TO BE THE LEAST-ACTIVE OF THE UPCOMING WORKWEEK, BUT IT
STILL FEATURES A BACKDOOR COOL FRONT SLIPPING SW FROM COASTAL NH/ME
EARLY IN THE DAY, THEN CONTINUING ON SW AND TENDING TO STALL
SOMEWHERE NEAR SOUTHWEST CT OR SOUTHERN NY LATE IN THE DAY.
CONSIDERABLE CLOUDINESS TO START THEN GIVES WAY TO INCREASING NE
WINDS, DECREASED CLOUD COVER AND TEMPS EITHER HOVERING OR SLOWLY
COOLING OFF. THOUGH TEMPS SHOULD REACH THE LOW 80S IN WESTERN MA/CT,
MIDDAY HIGHS IN THE MID/UPPER 70S EASTERN MA AND RI THEN COOL OFF TO
THE LOW/MID 70S BY SUNDOWN. CLOUD COVER THEN INCREASES MON NIGHT BUT
SHOULD STILL END UP DRY FOR THE MOST PART, THOUGH RAIN CHANCES
INCREASE INTO THE PRE-DAWN HOURS.
KEY MESSAGE 3...UNSETTLED TUESDAY THROUGH THURSDAY WITH SEVERAL
OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS, WITH A CHANCE FOR
SOME TO BECOME STRONG IN WESTERN MA AND CT. TIMING WHICH DAYS
MAY HAVE BETTER STORM CHANCES IS STILL UNCERTAIN.
TUE THROUGH THURS LOOK MORE ACTIVE/UNSETTLED, AS THE BACKDOOR
FRONTAL BOUNDARY STALLS FROM SW TO NE THROUGH NY STATE AND THE
NORTHEAST FRINGE OF A SUBSTANTIAL HEAT RIDGE CENTERED OVER THE OHIO
VALLEY BY TUE TRIES TO BUILD INTO THE NORTHERN MID-ATLANTIC AND
PERHAPS INTO A SMALL PORTION OF SOUTHERN NEW ENGLAND. THIS PLACES
SOUTHERN NEW ENGLAND BETWEEN A MORE STABLE AND SEASONABLE AIRMASS TO
THE NORTHEAST AND A WARM/HOT, HUMID AND CONDITIONALLY UNSTABLE
AIRMASS TO OUR SOUTHWEST. ABOVE THE STALLED SFC BOUNDARY LIES A BELT
OF STRONG NW FLOW ALOFT (E.G. 300 MB WINDS APPROACHING 100 KT),
WHICH TENDS TO FAVOR SHORTWAVE ENERGY IMPULSES MOVING SE ALONG THE
STALLED FRONT. SEVERAL OPPORTUNITIES FOR SHOWERS AND THUNDERSTORMS
SEEM LIKELY IN THIS PERIOD, BUT THE DETAILS OF WHICH ARE UNCERTAIN.
THOSE HINGE ON THE EXACT PLACEMENT/EVOLUTION OF THE FRONTAL
BOUNDARY, IF WE CAN TAP INTO THE MORE UNSTABLE AIR TO OUR SOUTHWEST,
AND THE TIMING OF SHORTWAVES IN THE STRONG NW FLOW ALOFT. MACHINE-
LEARNING GUIDANCE FROM THE GEFS AND COLORADO STATE SHOW SOME SEVERE
WEATHER POTENTIAL FOR OUR WESTERN/SOUTHWEST COUNTIES IN THIS PERIOD,
AND SPC HIGHLIGHTS A SMALL SLIVER OF WESTERN HAMPDEN COUNTY AND
WESTERN/CENTRAL HARTFORD COUNTY IN A 15% PROBABILITY FOR SEVERE
WEATHER FOR WEDNESDAY, UNCOMMON FOR WHAT IS A DAY-5 FORECAST. AM
SKEPTICAL WE GET ENTRENCHED INTO THE MORE UNSTABLE AIR TO OUR
SOUTHWEST BUT THE BEST POTENTIAL FOR DOING SO WOULD MORE LIKELY BE
SOUTH AND WEST OF WORCESTER. SOMETHING THAT WE'LL NEED TO MONITOR AS
WE GET INTO THE MESOSCALE MODEL RANGE. POPS ARE PRETTY HIGH GIVEN
THE MEDIUM-RANGE NATURE OF THE FORECAST FOR THE TUE THRU THURS
TIMEFRAME, IN THE 30-60% RANGE. TEMPERATURES WERE KEPT IN THE 70S TO
LOW 80S TUE THRU THURS, WITH RATHER MILD LOWS IN THE MID 60S (CLIMO
LOW TEMPERATURE VALUES ARE IN THE UPPER 50S/AROUND 60).
AVIATION /00Z SUNDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TONIGHT THROUGH SUNDAY...HIGH CONFIDENCE.
VFR. NW TO N WINDS 5 TO AROUND 10 KT, BECOMING LIGHT THIS
AFTERNOON. LOCAL SEABREEZES CONTINUE THROUGH THE AFTERNOON,
KICKING OUT AROUND SUNSET OR JUST AFTER IT. WINDS SHIFT TO THE
SW OVERNIGHT, WITH SPEEDS LESS THAN 5 KT, THEN INCREASE TO
AROUND 10 KT SUNDAY. SOME OCCASIONAL GUSTS LOOK POSSIBLE IN THE
AFTERNOON, PARTICULARLY TOWARDS THE CAPE AND ISLAND TERMINALS.
SUNDAY NIGHT...MODERATE CONFIDENCE.
VFR, THOUGH SHOWERS ARE POSSIBLE ACROSS CT/RI/SE MA AND INTO THE
CAPE AND ISLANDS. PERIODS OF MVFR VISIBILITIES IN ANY SHRA THAT
DEVELOP ARE POSSIBLE, THOUGH CONFIDENCE IS LOW AT THIS TIME.
WINDS SHIFT MORE NW HEADING INTO MONDAY MORNING, THOUGH REMAIN
LIGHT.
KBOS TERMINAL...HIGH CONFIDENCE.
KBDL TERMINAL...HIGH CONFIDENCE.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY: VFR.
MONDAY NIGHT: VFR. CHANCE SHRA.
TUESDAY: MVFR/IFR CONDITIONS POSSIBLE. CHANCE SHRA, SLIGHT
CHANCE TSRA.
TUESDAY NIGHT: MAINLY VFR, WITH AREAS IFR POSSIBLE. CHANCE
SHRA.
WEDNESDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. CHANCE SHRA,
SLIGHT CHANCE TSRA.
WEDNESDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. CHANCE SHRA,
SLIGHT CHANCE TSRA.
THURSDAY: MAINLY VFR, WITH AREAS IFR POSSIBLE. CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH SUNDAY NIGHT...HIGH CONFIDENCE.
HIGH PRESSURE REMAINS OVER THE WATERS TODAY BEFORE SHIFTING MORE
OFFSHORE SUNDAY. SHOWERS MAY MOVE IN OVER THE WATERS LATE SUNDAY
INTO SUNDAY NIGHT AS WEAK LOW PRESSURE TRACKS TOWARDS THE WATERS
FROM THE WEST. LOCAL SEABREEZES CONTINUE THROUGH THE REST OF
THIS AFTERNOON BEFORE WINDS SHIFT MORE SW TONIGHT. THESE SW
WINDS INCREASE TO AROUND 15 KT SUNDAY WITH GUSTS AROUND 20 KT
POSSIBLE IN THE AFTERNOON AND EVENING. SEAS REMAIN GENERALLY 2-3
FT WITH AREAS OF 4 FT SEAS POSSIBLE SUNDAY NIGHT.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY: WINDS LESS THAN 25 KT.
MONDAY NIGHT: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN
SHOWERS.
TUESDAY THROUGH TUESDAY NIGHT: WINDS LESS THAN 25 KT. CHANCE OF
RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT. CHANCE OF RAIN SHOWERS.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS
APPROACHING 5 FT. CHANCE OF RAIN SHOWERS.
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...LOCONTO/HRENCECIN
AVIATION...LOCONTO/BW/HRENCECIN
MARINE...LOCONTO/HRENCECIN
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