378
FXUS61 KBOX 302336
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
736 PM EDT Thu Jul 30 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Drier Friday, though some scattered showers remain possible in
  the afternoon.

- Slow moving frontal boundary focuses soaking rain from showers
  and thunderstorms late Sunday night into Monday, perhaps
  lingering into early Tuesday along the southeast coast.

&&

.DISCUSSION...
KEY MESSAGE 1...Drier Friday, though some scattered showers remain
possible in the afternoon.

The low responsible for yesterday`s rain is shifting off to the
northeast and is just offshore of Cape Cod as of the time of
writing. Its associated trough will shift NE as well into Maritime
Canada, allowing ridging aloft to make its way into the northeast.
Onshore winds will continue through this afternoon, lending to a
continued chance for some scattered showers over much of eastern MA
into RI. Parts of western CT may also see some scattered showers
through the evening. Continued moisture aloft and onshore flow will
keep cloudier conditions in place into tonight as well, ushering in
high pressure and more NW flow that will aid in clearing the region.
High pressure returning will lend to the possibility of late
morning/early afternoon seabreezes as well Friday as the
aforementioned NW flow remains light. However, the chance for some
scattered showers lingers in the afternoon. 925 mb temperatures
around 18C will support highs making a return to the upper 70s and
low 80s after being under a cooler airmass these last few days.

Light to calm SW winds Friday night in conjunction with clearer
skies may increase the chances for radiational cooling. Given the
recent rainfall, this all may increase chances for patchy fog
development overnight into Saturday morning.

KEY MESSAGE 2...Slow moving frontal boundary focuses soaking
rain from showers and thunderstorms late Sunday night into
Monday, perhaps lingering into early Tuesday along the southeast
coast.

A slow-moving cold front working through NY/PA Sunday brings our
next chance for rain for late Sunday evening into at least much of
Monday. The main change in the past 24-hours worth of guidance is
that the frontal boundary has slowed down about 12 hours compared to
previous, in response to stronger meridional flow nearly parallel to
the frontal boundary. That also leads to a influx of slightly higher
precipitable water values which in some global model solutions are
upwards of 2". Main risk this front will bring to Southern New
England is another period of soaking downpours given the slow-moving
frontal zone interacting with the highly moisture-rich airmass
preceding it. It`s still uncertain what the highest rain totals
would look like and where they would fall, but with a few spot areas
in interior Southern New England having registered quite a bit of
rain in the last 48 hours, there would be some risk for localized
street flooding but still view this risk as a lower chance. EPS/GEFS
probabilities still show moderately high (40-60%) probs 24-hr rains
over a half inch but low (< 30%) probs of 24-hr rains over an inch.
This is something that will need to be monitored in later guidance.
particularly if the frontal boundary slows down more. It now looks
like the front won`t sufficiently clear Southern New England until
later Monday, and could still linger into Tuesday across southeast
New England. It still doesn`t look like thunderstorms will be
capable of severe weather with a weakly-unstable, weak-lapse-rate
and weak-shear convective setting. Southerly flow also increases
over the waters, which could prompt marine headlines for our
boaters/mariners.

&&

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

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

00z TAF Update:

Tonight: Moderate confidence.

SCT -SHRA still around mainly for the eastern terminals, pulling
off toward the ESE. Expect by 02-03z Fri that showers will have
ended. Categories are generally SCT-BKN VFR with occasional
MVFR lurking around; however modest cooling and light northerly
winds should allow for MVFR stratus with MVFR-IFR mist to
develop or fill in after 04z. Winds light NE to N, becoming calm
at times.

Friday...High confidence.

VFR. Light N winds with coastal sea breezes. Slight chance of
some scattered showers.

Friday Night...High confidence.

VFR for most with chances for MVFR towards the Cape and Islands.
Light SW winds generally at or below 5 kt, going calm towards
the interior.

KBOS Terminal...Moderate confidence in TAF. VFR/MVFR with VCSH
for lingering SHRA around the terminal. More persistent MVFR
with MVFR visby BR develop overnight, dissipating/lifting by
12-13z. Seabreezes develop Fri 14-15z.

KBDL Terminal...High confidence in TAF. VFR, VCSH thru 03z with
scattered passing SHRA. MVFR-IFR mist/low clouds develop after
07z, with recent rain visbys could drop into the IFR range, but
returns to VFR 12-13z Fri.

Outlook /Saturday through Tuesday/...

Saturday through Saturday Night: VFR.

Sunday: VFR. Breezy. Slight chance SHRA.

Sunday Night: VFR. Chance SHRA, slight chance TSRA.

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

Monday Night: VFR. Breezy. Chance SHRA.

Tuesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Winds shift more N to even NW in spots tonight as the low
pressure just offshore continues shifting into the Maritimes.
Seas continue to diminish heading into tonight and Friday,
settling more to 2-4 ft. Any lingering rain showers through this
afternoon may continue to lower visibilities to 1-3NM
periodically.

Winds become lighter Friday and shift more to the SW heading
into Friday night. Fog expected to develop over much of the
southern waters and off the east coast of Cape Cod.

Outlook /Saturday through Tuesday/...

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

Saturday Night through Sunday: Winds less than 25 kt.

Sunday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Chance of rain showers, slight chance of thunderstorms.

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

Monday Night: Winds less than 25 kt. Seas up to 5 ft. Chance of
rain showers, slight chance of thunderstorms.

Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ250.

&&

$$

DISCUSSION...Loconto/Hrencecin
AVIATION...Loconto/Hrencecin/McMinn
MARINE...Loconto/Hrencecin