515
FXUS61 KBOX 311840
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
240 PM EDT Sun Aug 31 2025

.SYNOPSIS...
High pressure remains in control through at least Thursday, bringing
an extended stretch of dry weather and seasonably warm temperatures.
Turns more humid by Friday, with an approaching cold front bringing
showers and a chance of thunderstorms. Humid conditions and risk for
showers may linger into Saturday ahead of the cold front, then
cooler and drier weather returns next Sunday as the front moves off
the coast.

&&

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

* Local seabreezes last through this afternoon. Quiet night with mid
  to high level cloud cover building in.

High pressure continues to dominate the pattern, keeping the rest of
today and tonight dry. Some mid to high level clouds build in
tonight as some moisture aloft advects in from the south. With winds
becoming light and clouds building in, a more mild night is ahead
tonight with lows in the upper 40s to mid 50s. East/southeast
coastal areas may be even warmer with lows in the upper 50s.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
Key Messages:

* Seasonable temperatures and dry conditions continue with onshore
  winds

With the surface high shifting into Maine, NE flow will kick in
Monday morning and continue through the day. Coastal areas will be
slightly cooler than the rest of the region as a result. Much of the
interior can expect to see seasonable highs in the upper 70s, with
some spots in the valleys reaching 80F. A shortwave over the Great
Lakes region will close off and shift into the mid-Atlantic Monday.
Moisture aloft from this circulating disturbance will move in over
southern New England, leading to continued mid to high cloud cover.
This is expected to clear through Monday night, aside from much of
eastern MA, RI. Lows Monday night are expected to be mild much like
tonight, ranging from the low 50s inland to the mid/upper 50s
towards the eastern coastlines.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Key Messages:

* Dry and seasonable Tue with somewhat warmer weather Wed & Thu

* Increasing rain chances Thu night & Fri and turning more humid

* Still somewhat humid Sat with some risk for showers, then cooler
  and drier Sunday

Details:

High pres remains in control through Wed and likely lasting into Thu
as the high pres slowly moves offshore. Dry and near seasonable
temps Tue with NE flow, then a slight warming trend Wed-Thu as the
high moves offshore with S-SW flow developing which brings warmer
low level temps into SNE. Highs should reach into the upper 70s-
lower 80s with GEFS and EPS showing at least moderate probs of temps
80+ away from the south coast. Dry weather expected to last through
Thu as next system will be slower to move in from the west

As we move to the end of the week, a deep upper low will set up
north of the Gt Lakes with somewhat amplified trough to the south
across E-central US. Higher PWAT plume within the deep SW flow will
advect northward into SNE leading to increasing chance of showers,
especially Thu night into Fri as a shortwave rotating around the
upper low acts on deep moisture plume and low level convergence.
There is some instability present so a few t-storms will be possible
as well. Not looking at heavy rainfall as ensembles only indicating
low-moderate probs of 0.50" QPF.  It will become somewhat humid Fri
as higher PWAT air moves into the region with dewpoints climbing
through the 60s.

Looking ahead to the weekend, upper trough is still hanging back to
the west and a shortwave and main frontal boundary still has to move
through so can`t rule out another round of showers and chance of t-
storms Sat. But timing of this boundary will determine the extent of
the shower risk. Potential for warm and humid conditions Sat if we
remain in the pre-frontal airmass, then it should turn cooler and
drier Sunday as front moves offshore.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Forecaster Confidence Levels...

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

18z TAF Update:

Rest of Today through Monday...High confidence.

VFR through the period.

Onshore winds kick back to SSW after 00z becoming light N/NNW
later tonight. Light N flow acros the rest of the interior. Mid
and high clouds move in overnight.

A bit more in the way of high clouds for Monday but still VFR
with NE winds around 5-10 kt.

Monday Night through Tuesday...High confidence.

VFR Monday night and Tuesday, but NE winds pick up a bit,
especially along the SE coast. While winds are light northerly
for most of southern New England, NE winds become around 10-15
kt for the east coast and around 15-20 kt for the Cape and
Islands.

KBOS TAF...High confidence in TAF.

KBDL TAF...High confidence in TAF.

Outlook /Tuesday through Friday/...

Tuesday through Wednesday Night: VFR.

Thursday: VFR. Breezy.

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

Friday: Mainly MVFR, with local IFR possible. Breezy. Chance
SHRA, slight chance TSRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Monday Night...High confidence.

Winds/seas remain below SCA criterion in this period. Light NE/E
winds around 10-15 kt become light tonight. NE winds around
5-10 kt Monday, increasing to around 15-20 kt Mon night. Seas
4ft or less all waters.

Tuesday...Moderate confidence.

NE winds increase to near-SCA levels (around 20-25 kt) over the
southeast waters, with seas nearing 4-6 ft. May need SCAs for
waters adjacent to Cape Cod and the Islands. Possible risk of
rip currents against east-facing beaches. Elsewhere, NE winds
around 10-15 kt with gusts to 20 kt and seas 4 ft or less.

Outlook /Tuesday through Friday/...

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

Tuesday Night: Winds less than 25 kt. Seas up to 5 ft.

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

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

Thursday: Winds less than 25 kt.

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

Friday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Chance of rain
showers, slight chance of thunderstorms.

&&

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

&&

$$

SYNOPSIS...KJC/Hrencecin
NEAR TERM...Hrencecin
SHORT TERM...Hrencecin
LONG TERM...KJC
AVIATION...KJC/Hrencecin/Mensch
MARINE...KJC/Hrencecin