845
FXUS61 KBOX 291700
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
100 PM EDT Fri Aug 29 2025

.SYNOPSIS...
A cold front crossing the region will bring showers and
thunderstorms through this evening. Some storms could produce
small hail, gusty winds, and brief downpours. A stretch of dry
and early fall like weather will prevail through much of next
week as high pressure remains over the Northeast.

&&

.NEAR TERM /THROUGH TONIGHT/...
Updated 100 PM Fri:

Key Messages:

* Storms developing in central MA/eastern CT around midday and
  heading east during afternoon/evening.

* Impacts to the PM commute/holiday weekend travel from
  localized street flooding and poor visibility in downpours.

* Brief strong wind gusts and small hail possible in strong
  storms, but most storms will be sub-severe.

High-res models were on target once again and line of storms was
developing on schedule from CT into central MA. Second area of
storms was also forming in SE CT and southern RI, heading to
Providence area and SE MA, which has been focus for convection
since this morning. Earlier thinking remains the same - we will
probably see a fairly solid line of storms working east into
Boston/Providence areas this afternoon before reaching south
coastal areas later in day.

Timing looks to be:
 - Central MA/Eastern CT through 3 PM
 - Providence through 4 pm
 - Greater Boston 2-7 PM
 - South Coast, Cape Cod, Islands 5-9 PM

Severe threat remains fairly low given limited instability, weak
shear, and marginal mid level lapse rates, but given colder air
aloft we`ve already seen several small hail reports and even
some stronger wind gusts (35-45 mph). While this does not have
the look of a big severe day, we can`t rule out having to issue
a few SVRs. For boating interests, and since we`re at the start
of the holiday weekend with increased recreational boating
traffic, be aware that we`ll probably be issuing several SMWs as
well.

Also need to be aware of brief downpours given increasing PWATs
(up to 1.2") but none of the moisture parameters are off the
charts, and forecast soundings are not overly impressive. Still,
any downpours in urban areas during PM rush hour (and holiday
weekend travel) could result in localized street flooding and
poor visibility at times. We`ve already seen a lot of 1.0-1.5"
per hour rainfall rates with minor street flooding in the
Providence area.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
Updated 100 PM Fri:

Key Messages:

* Dry and cooler to start the weekend.

Upper low meandering through northern New England will maintain
cyclonic flow across region Sat, which will lead to diurnal
cloudiness and perhaps a few sprinkles, mainly across northern
MA which is in closer proximity to cold pool aloft. Definitely a
taste of fall.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Updated 100 PM Fri:

Key Messages:

* Stretch of dry weather much of next week.

Ensemble guidance continues to favor dry conditions through at
least Thursday, before an approaching cold front brings
scattered showers sometime Thursday night or Friday, which is
our next chance of seeing any appreciable rainfall. Overall,
dry and seasonable weather will prevail with sea breezes likely
each afternoon.

&&

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

18z TAF Update: High confidence.

Main concern is for numerous SHRA/TSRA through 23z, especially
from ORH to BED, BOS, and PVD where some storms will bring
MVFR/IFR with gusty winds to 30-40kt, small hail, and brief
downpours. Could be looking at a fairly solid line of TS moving
through these locations. Farther west, more in way of scattered
showers with brief MVFR.

Otherwise, VFR through Sat night. Probably will see VFR ceilings
060-080 Sat as diurnal clouds develop and perhaps a few
sprinkles mainly in northern MA.

KBOS TAF...High confidence, including timing of TS.

KBDL TAF...High confidence in TAF. Fairly confident TS stays
well to the east.

Outlook /Sunday through Wednesday/...

Sunday through Wednesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Updated 100 PM Fri:

High confidence through much of next week. No marine headlines
expected with winds and seas staying below SCA.

Approaching cold front brings scattered showers and
thunderstorms, especially to E MA waters and immediate south
coastal waters, through this evening. Some storms could produce
wind gusts of 30-40kt and small hail, so anticipate that we may
be issuing Special Marine Warnings, especially given increased
boating traffic for start of holiday weekend.

Front moves offshore tonight, followed by an extended stretch of
dry weather as high pressure builds over Northeast. May see some
increase in seas on outer south coastal waters as we approach
the middle of next week.

Outlook /Sunday through Wednesday/...

Sunday through Tuesday Night: Winds less than 25 kt.

Wednesday: Winds less than 25 kt. Seas locally approaching
5 ft.

&&

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

&&

$$

SYNOPSIS...JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...JWD
AVIATION...JWD
MARINE...JWD