337
FXUS61 KBOX 032350
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
750 PM EDT Thu Sep 3 2026

.WHAT HAS CHANGED...
No significant changes to the forecast.

&&

.KEY MESSAGES...

- A few rounds of scattered showers and t-storms possible each
afternoon. Best chance is Thursday evening, then Saturday.

- Fall-like feel for Sunday, then more seasonable for Labor Day. A
gradual warm-up throughout the week with continued dry weather
through at least Wednesday or Thursday.

- Elevated risk for dangerous rip currents through the Holiday
 Weekend, especially Sunday into Labor Day.

&&

.DISCUSSION...
KEY MESSAGE 1...A few rounds of scattered showers and t-storms
possible each afternoon. Best chance is Thursday evening, then
Saturday.

The frontal wave has brought a good amount of dry mid-level air in
its wake allowing for plenty of breaks of sun, especially for
western SNE. Mesoanalysis indicates about 1500 J/kg of surface based
CAPE. High-resolution guidance has backed off on the coverage of
convection with this second wave of precip chances for the afternoon
and evening likely owing to the lingering cloudy skies/morning rain
showers resulting in a less favorable environment. Even the latest
HRRR is not initializing well, showing widespread convection at 19z
while the radar remains nearly bare. Even so, as the front drops
south it may kick off some isolated convection, expected to be sub
severe with frequent lightning the main threat. The greatest threat
will be along and south of the frontal boundary, mainly south of the
MA pike.

Looking toward the Friday-Saturday period, drier NW flow kicks in
with PWATs dropping down to around an inch or less. Expecting this
to result in a mostly dry stretch with a mix of clouds and sun. Even
so, with a mid level trough and low pressure just offshore we`ll
still see periodic diurnal shower chances. Certainly not a washout,
but keeping low probability rain chances in the forecast, mainly for
Saturday afternoon.

Friday will be the warmest day of the whole forecast as a slightly
warmer airmass pushes in; 850 mb temps briefly reach ~15C Friday
before dropping to ~8C Saturday resulting in high temperatures in
the low to mid 80s and low to mid 70s respectively.

KEY MESSAGE 2...Fall-like feel for Sunday, then more seasonable for
Labor Day. A gradual warm-up throughout the week with continued dry
weather through at least Wednesday or Thursday.

Saturday night through the middle of the upcoming week features
fairly benign conditions, with little in the way of rainfall
chances. The 500mb forecast map shows somewhat of an omega ridge
centered across the middle of the country, with a closed mid-level
low centered over Nova Scotia Sunday afternoon. The omega ridge
flattens out, with semi-zonal flow developing across the coast by
Tuesday and then shortwave troughing for late week across the
northeastern states, likely leading to the next chance for active
weather for southern New England. At the surface, high pressure
builds in from the northwest Sunday, with its origins in northern
Canada. Surface high pressure remains the dominant weather feature
throughout the majority of the forecast period, leading to a stretch
of dry weather.

Temperatures aloft are cooler Sunday, associated with that mid-level
low east of New England. 925mb temperatures are only around +8C to
+10C, which with boundary layer mixing supports highs in the upper
60s to low 70s. Thus, Sunday will feel very much like autumn, with a
blend of sun and clouds, northerly winds and dew points in the low
50s. While winds won`t be overly strong, the combination of cooler
temperatures and lower dew points will make for a rather crisp day.
Sunday night could feature some decent radiational cooling as high
pressure settles across the region, though this will depend on how
quickly winds diminish. If winds become light enough, NBM guidance
may be too warm across the typically cooler, effective radiators.
For example, the NBM has KOWD around 54F, while the cooler CONSMOS
guidance suggests temperatures could fall as low as the mid to upper
40s. Otherwise, lows are generally expected in the 50s.

Good news if you aren`t ready for pumpkin spice weather, as
temperatures will trend warmer throughout the week from WAA aloft.
925mb temperatures climb +14C to +18C, supporting near-seasonable
highs in the upper 70s for Labor Day, then upper 70s to lower 80s
Tuesday into the middle part of next week. Humidity remains
tolerable as well, with dew points generally in the upper 50s to
around 60F. Labor Day itself looks quiet and dry, though there will
be a high risk for rip currents along the ocean beaches.

KEY MESSAGE 3...Elevated risk for dangerous rip currents through the
Holiday Weekend, especially Sunday into Labor Day.

Persistent northeast flow, long-period swell, and offshore seas of 4-
7 feet will continue to support an elevated risk for dangerous rip
currents through the Holiday Weekend, especially Sunday into Labor
Day for east-facing ocean beaches. With otherwise quiet weather
expected, those heading to the beach should be mindful that ocean
conditions may still be hazardous. Be sure to check with local beach
staff or lifeguards regarding ocean conditions before entering the
water.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Update: 00z TAF

Through 12z Friday...Low confidence.

Have rather low confidence in this portion of the TAF period. An
area of marine stratus off the coast of Maine will advect southwest
into eastern Massachusetts overnight, including KBOS. Confidence is
low in how far west the stratus extends and how low ceilings and
visibilities may fall. While confidence in at least MVFR conditions
is high across eastern Massachusetts, there remains a low
probability (less than 30%) that conditions could fall to LIFR for
both ceilings and visibilities. This trend will need to be monitored
overnight, and AMDs may become likely.

Wind direction may become variable at times due to weak high
pressure building in. This weak wind field is also contributing to
lower confidence in the evolution and extent of the advecting marine
stratus. Lastly, given the wet ground and periods of mostly clear
skies, radiation fog is possible across the CT River Valley,
resulting in MVFR to borderline IFR conditions at KBDL.

Friday...Moderate confidence in trends, lower confidence in timing.

Between 12-15z, conditions improve to VFR for most, with the
exception of the outer Cape and KACK. There, it may take well into
the early afternoon for conditions to improve to VFR. Light north-
northwest winds for most, though a sea breeze develops across
eastern coastal Massachusetts, including KBOS.

Friday Night...High confidence.

VFR. Light northwest winds.

KBOS Terminal...Low confidence.

Marine stratus from the Gulf of Maine will advect into Boston Harbor
overnight, though confidence remains low in how low ceilings and
visibilities may fall. Currently have the greatest confidence,
albeit still low, that ceilings fall to higher-end IFR with MVFR
visibilities from roughly 08z through 12z. Some improvement to MVFR
is possible during the morning push, otherwise trending to VFR after
14/15z Friday. An onshore wind is also anticipated Friday.

KBDL Terminal...Moderate confidence.

A period of MVFR conditions is possible between 04z and 12z, with a
lower chance (less than 30%) of IFR conditions.

Outlook /Friday Night through Tuesday/...

Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance
SHRA, slight chance TSRA.

Saturday Night: Mainly VFR, with local MVFR possible. Breezy.
Slight chance SHRA.

Sunday: VFR. Breezy.

Sunday Night through Tuesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Today through Friday Night...

Winds shift to the west/northwest through Thursday night into
Friday morning before shifting to the S/SW late Friday. A few
showers and t-storms may move over the southern waters this
evening then tranquil weather persists. Seas 2-3 ft.

Outlook /Friday Night through Tuesday/...

Saturday: Winds less than 25 kt. Areas of seas approaching
5 ft.

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of rough seas.

Sunday Night through Labor Day: Winds less than 25 kt. Local
rough seas.

Monday Night through Tuesday: Winds less than 25 kt. Areas of
seas approaching 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

DISCUSSION...BW/Dooley
AVIATION...BW/Dooley
MARINE...BW/Dooley