060
FXUS61 KBOX 111820
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
220 PM EDT TUE AUG 11 2026
WHAT HAS CHANGED
INCREASED UNCERTAINTY REGARDING SHOWER POTENTIAL WEDNESDAY.
KEY MESSAGES
- SEASONABLE TEMPERATURES AND COMFORTABLE HUMIDITY WEDNESDAY.
LOW CHANCE FOR A FEW SHOWERS FOR THE SOUTH COAST AND CAPE AND
ISLANDS WEDNESDAY. OTHERWISE, DRY.
- RAIN CHANCES INCREASE LATER THURSDAY INTO FRIDAY AS A FRONT
LINGERS NEAR THE SOUTH COAST OF NEW ENGLAND. HIGH PRESSURE
THEN RETURNS DRIER AND COOLER WEATHER FOR THIS WEEKEND. RAIN
CHANCES MAY INCREASE AGAIN EARLY NEXT WEEK AS A LOW PRESSURE
PASSES THROUGH.
DISCUSSION
KEY MESSAGE 1...SEASONABLE TEMPERATURES AND COMFORTABLE HUMIDITY
WEDNESDAY. LOW CHANCE FOR A FEW SHOWERS FOR THE SOUTH COAST
AND CAPE AND ISLANDS WEDNESDAY. OTHERWISE, DRY.
MOST AREAS ARE LIKELY TO REMAIN DRY FOR THE REMAINDER OF THE
AFTERNOON AND EVENING. THE ONE EXCEPTION IS THE CHANCE FOR A
STRAY SHOWER OR STORM TO MAKE IT INTO NORTHWEST CT LATE
AFTERNOON/EARLY EVENING. OVERNIGHT TEMPERATURES FALL INTO THE
60S WITH PERIODS OF CLOUD COVER.
THERE IS STILL LOWER CONFIDENCE IN THE POTENTIAL FOR AN OFFSHORE
LOW PRESSURE SYSTEM TO BRUSH ACROSS THE SOUTHERN PORTION OF
SOUTHERN NEW ENGLAND ON WEDNESDAY. THIS HAS BEEN REFLECTED
AMONGST DETERMINISTIC AND ENSEMBLE GUIDANCE WITH SOME SOLUTIONS
DEVELOPING A LOW PRESSURE THAT TRACKS NORTH TO BRING SHOWERS TO
THE SOUTH COAST AND CAPE/ISLANDS. OTHER SOLUTIONS DON'T DEVELOP
A "STRONGER" SURFACE LOW AT ALL OR TRACK IT TOO FAR SOUTH TO
BRING SHOWER CHANCES TO SOUTHERN NEW ENGLAND. GEFS PROBABILITIES
FOR > .01" RANGE 30 TO 60 PERCENT WITH PROBABILITIES DROPPING
OFF QUICKLY AS YOU MOVE NORTH OF THE IMMEDIATE COAST. ECMWF
PROBABILITIES ARE > 20%. THE NAM AND RRFS HAVE TRENDED THE MOST
NORTH BRINGING A MORE ROBUST BATCH OF SHORES ACROSS AT LEAST
SOUTH AND SOUTHEAST SOUTHERN NEW ENGLAND. GIVEN THE SPREAD HERE,
WORST CASE WILL BE A SOME LIGHT SHOWERS WEDNESDAY AM/EARLY
AFTERNOON WITH THE GREATER RISK FOR THE SOUTH COAST AND
CAPE/ISLANDS. IF THIS SYSTEM PASSES MAINLY SOUTH, EXPECT A DRIER
DAY. WITH FLOW ALOFT BECOMING MORE ZONAL, TEMPERATURES COOL
SLIGHTLY BRINGING MORE SEASONABLE HIGHS WEDNESDAY IN THE LOW TO
MID 80S.
THERE WILL LIKELY BE A SHIFT TO A MORE UNSETTLED WEATHER PATTERN
LATE WEDNESDAY INTO THURSDAY WITH INDICATIONS OF A FRONTAL
BOUNDARY STALLING ACROSS A PORTION OF SOUTHERN NEW ENGLAND. A
FEW EMBEDDED WEAK DISTURBANCES RIDE THIS BOUNDARY, RESULTING IN
PERIODS OF SHOWERS ARRIVING AS EARLY AS OVERNIGHT WEDNESDAY
NIGHT.
KEY MESSAGE 2...RAIN CHANCES INCREASE LATER THURSDAY INTO FRIDAY
AS A FRONT LINGERS NEAR THE SOUTH COAST OF NEW ENGLAND. HIGH
PRESSURE THEN RETURNS DRIER AND COOLER WEATHER FOR THIS WEEKEND.
RAIN CHANCES MAY INCREASE AGAIN EARLY NEXT WEEK AS A LOW
PRESSURE PASSES THROUGH.
STILL SOME TIMING DIFFERENCES TO BE WORKED OUT THURSDAY INTO
FRIDAY. MOST OF THE LATEST GLOBAL GUIDANCE SUITE HAS A COLD
FRONT NEAR THE SOUTH COAST OF NEW ENGLAND THURSDAY MORNING. THE
DIFFERENCES ARISE FROM HOW QUICKLY THIS FRONT GETS SOUTH ENOUGH
OF OUR REGION TO NO LONGER BE A FACTOR IN OUR WEATHER. THE
CONSENSUS APPROACH KEEPS THIS FRONT CLOSE TO THE SOUTH COAST
INTO FRIDAY MORNING, BUT THIS TIMING COULD BE QUICKER, LEADING
TO A DRIER DAY FRIDAY. NOT A LOT OF HUMIDITY TO WORK WITH, BUT
THINKING THERE IS AT LEAST A RISK FOR DIURNAL SHOWERS AND
THUNDERSTORMS. A GOOD PORTION OF THIS TIME SHOULD REMAIN DRY FOR
MOST.
THIS FRONT SHOULD FINALLY PUSH OFFSHORE LATER FRIDAY, ALLOWING
HIGH PRESSURE TO BUILD ACROSS SOUTHERN NEW ENGLAND. THIS LEADS
TO DRIER AND COOLER CONDITIONS THIS WEEKEND. THE TIMING FOR
EARLY NEXT WEEK IS NOT CERTAIN AS WELL. WHILE THERE ARE SOME
DIFFERENCES IN THE TIMING, THE OVERALL CONSENSUS IS FOR A LOW
PRESSURE TO MOVE ACROSS NORTHERN NEW ENGLAND SOME TIME MONDAY.
THIS SYSTEM SHOULD BE OFF TO THE EAST BY TUESDAY. THIS TIMING
COULD CHANGE WITH LATER FORECASTS.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH 00Z...HIGH CONFIDENCE.
VFR. WNW TO NW WINDS 8-12 KTS WITH AN OCCASIONAL GUST TO 18 KTS
THIS AFTERNOON. LOW CHANCE (< 15%) FOR AN ISOLATED SHOWER OR
STORM TO BE IN VICINITY OF BDL AFTER 21Z THROUGH 00Z.
TONIGHT...HIGH CONFIDENCE.
VFR. WINDS GENERALLY OUT OF NW LESS THAN 10 KTS. THERE IS A LOW
PROBABILITY FOR A SHOWER FOR THE ISLANDS (< 20%).
WEDNESDAY...HIGH CONFIDENCE.
VFR. LIGHT N/NW WINDS. EASTERLY SEA BREEZE DEVELOPS FOR BOS AND
OTHER EAST COAST TERMINALS 14-17Z. THERE IS A LOW CHANCE
(10-20%) FOR A FEW SHOWERS ALONG THE IMMEDIATE SOUTH COAST AND
CAPE/ISLANDS 09-15Z WITH "GREATER RISK" FOR THE ISLANDS (ACK).
OTHERWISE, DRY CONDITIONS FOR OTHER TERMINALS.
KBOS TERMINAL...HIGH CONFIDENCE. WILDFIRE SMOKE ALOFT POSSIBLE.
KBDL TERMINAL...HIGH CONFIDENCE. WILDFIRE SMOKE ALOFT POSSIBLE.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY: VFR. BREEZY. SLIGHT CHANCE SHRA.
THURSDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
FRIDAY THROUGH FRIDAY NIGHT: VFR. BREEZY.
SATURDAY THROUGH SATURDAY NIGHT: VFR.
SUNDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
WINDS AND SEAS BELOW SCA CRITERIA THROUGH WEDNESDAY. NW WINDS
TONIGHT BECOME EASTERLY WEDNESDAY 10-15 KTS. SEAS 3 FT OR LESS.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY: WINDS LESS THAN 25 KT.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN
SHOWERS.
FRIDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
SLIGHT CHANCE OF RAIN SHOWERS.
FRIDAY NIGHT THROUGH SATURDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT.
SATURDAY NIGHT THROUGH SUNDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...BELK/MENSCH
AVIATION...BELK/MENSCH
MARINE...BELK/MENSCH
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