316
FXUS61 KBOX 281817
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
217 PM EDT Thu Aug 28 2025

.SYNOPSIS...
A cold front will bring a round of showers and thunderstorms on
Friday, with small hail and gusty winds possible with a few of the
strongest storms. Otherwise...dry and very pleasant weather pattern
should prevail over most of the Holiday Weekend into most of next
week with just a low risk for a few brief showers on Labor Day.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages...

* Dry tonight with lows in the 50s to the lower 60s
* Low risk for a few spot showers toward daybreak

Details...

Tonight...

An approaching cold front will move eastward into western NY/western
PA tonight. This coupled with high pressure to our east will
generate a southerly flow with a gradual increase in low level
moisture. This will result in overnight low temps a bit milder than
last night...mainly in the 50s to the lower 60s. Some mid and high
cloudiness will overspread the region ahead of the approaching
shortwave/cold front. That being said...dry weather will prevail
tonight with just the risk for a few spot showers toward daybreak.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Key Messages...

* A round of showers & scattered t-storms Fri...Highs in the 70s
* A few stronger storms may bring small hail/gusty winds Fri PM
* Drying out Friday night and turning cool with lows in the 40s & 50s

Details...

Friday...

A fairly dynamic upper level shortwave/cold front will approach the
region on Friday. This cold front will cross the region Friday
afternoon into early Friday evening...bringing a round of showers
and scattered thunderstorms with it. We will break it down more
below.

A modest southwest LLJ in the warm air advection pattern may result
in an initial round of a few showers and perhaps an isolated t-storm
or two Friday morning. That being said...the greater risk for more
widespread showers and scattered t-storms will be Friday afternoon
into early Friday evening. Low level moisture will be limited...but
we do think dewpoints will recover into the 55 to 60 degree range.
In addition...the upper level trough is quite vigorous with cold
500T on the order of -16C/-17C! This coupled with highs in the 70s
shield yield Capes on the order of 500 to 1000 J/KG. Given the
amount of forcing along the front...we expect showers to develop
along with scattered t-storms Friday afternoon/early evening. Given
the cold temps aloft...the strongest storms may contain small hail
and gusty winds. While we can not rule out an isolated severe t-
storm or two...this appears to be mainly sub-severe storms with
small hail/gusty winds. The main time of concern for the showers and
scattered t-storms is between noon and 8 pm.

Friday night...

Any lingering showers/t-storms will exit the coast by early Friday
evening. Otherwise...a dry and cooler northwest flow of air will
work into the region behind the cold front. This will result in
another unseasonably cool night. Low temps Friday night will bottom
out in the middle to upper 40s across the normally cooler outlying
locations to the 50s elsewhere.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

Key Points

 * Extended period of dry and pleasant weather this weekend into
   next week

 * Low chance for Isolated showers/thunderstorms Monday afternoon

Surface high pressure builds in behind Fridays cold front, brining
an extended stretch of dry and pleasant fall like weather to the
region. High temperatures will be in the 70s with lows in the 50s
during this stretch. The upper level pattern is a bit more messy and
uncertain as upper level trough and cold pool that were originally
going to move off shore by Sunday could stall and back build over
the region by Monday.  This could lead to another round of isolated
showers and thunderstorms Monday afternoon as 500-1000 J/kg of
SBCAPE builds underneath the cold pool. Given the cold temps aloft,
small hail/graupel will be possible once again with any stronger
thunderstorms. After Monday, the next best chance for precipitation
appears to arrive late in the week as global guidance is in pretty
good agreement on a stronger shortwave trough exiting the Great Lakes

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
Forecaster Confidence Levels...

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

18z TAF Update...

This afternoon through tonight...High confidence.

VFR. SSW 5-12 knots.

Friday...High confidence.

Mainly VFR conditions but we do expect a round of showers and
scattered t-storms which will bring briefly lower conditions. While
a few showers will be possible Friday morning...appears the greater
risk will be after 16z/17z until about 00z from west to east. A few
of the stronger storms may contain small hail/gusty winds.

Friday night...High confidence.

Any lingering showers/t-storms will exit the coast early Friday
evening. Otherwise...VFR conditions with light NW winds.

KBOS TAF...High confidence in TAF. The main concern is the risk for
a few t-storms in the vicinity of the terminal Friday afternoon into
the evening push.

KBDL TAF...High confidence in TAF. The main concern is the risk for
a few t-storms in the vicinity of the terminal Friday afternoon.

Outlook /Saturday through Monday/...

VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight through Friday night...High confidence.

S-SW winds are expected tonight into Friday ahead of an approaching
cold front. We may see some 20+ knot wind gusts and choppy seas
Friday...but thinking conditions remain below small craft advisory
thresholds. The main concern though will be for a few strong t-
storms later Friday into early Friday evening that may contain small
hail/gusty winds as a cold front crosses the waters. Winds will then
shift to the WNW Friday night behind the cold front...but should
remain below small craft advisory thresholds.

Outlook /Saturday through Monday/...

Saturday: Winds less than 25 kt. Slight chance of rain showers.

Saturday Night through Labor Day: Winds less than 25 kt.

&&

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

&&

$$

SYNOPSIS...Frank
NEAR TERM...Frank
SHORT TERM...Frank
LONG TERM...KP
AVIATION...Frank/Loconto
MARINE...Frank/Loconto