783
FXUS61 KBOX 310626
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
226 AM EDT Fri Jul 31 2026

.WHAT HAS CHANGED...

No significant changes.

&&

.KEY MESSAGES...

- Drier and warmer Friday with only some scattered afternoon showers
and a mix of clouds and sun.

- A cold front brings the return of rain Sunday night and Monday,
perhaps lingering into Tuesday.

- Drying and warming trend toward Wed/Thu.

&&

.DISCUSSION...

KEY MESSAGE 1...Drier and warmer Friday with only some scattered
afternoon showers and a mix of clouds and sun.

Finally some mid level height rises today as weak ridging builds in
with building high pressure at the surface. Even so, the trough is
slow to exit and cyclonic flow with a cold pool aloft (500 mb temps
-10 to -12C) will, after more sun/clearing in the morning, allow for
diurnal cumulus to pop us as well as some widely scattered afternoon
showers. That being said, the airmass is drier under backing NW flow
and most locations will be dry. Regardless, the airmass will be
warming allowing highs to get back into the upper 70s and low 80s.
Light winds mean coastal seabreezes keep the immediate coastline
comfortably in the mid 70s.

KEY MESSAGE 2...A cold front brings the return of rain Sunday night
and Monday, perhaps lingering into Tuesday.

After drier and warmer (mid to upper 80s) weather on Saturday under
a brief ridge of high pressure the patterns again begins to break
down toward the end of the weekend/start of the work week. This is
also where we begin to see model consensus decrease, so confidence
in exact timing details is low. That being said, there is good
agreement that an upper trough will dig into the east coast pulling
a deep plume of subtropical moisture north ahead of it and into New
England centered around Monday. The GFS is the more amplified
solution with a stronger southern cut-off low lingering into next
week and higher rainfall totals for SNE. A key component will be the
cold front which crosses the region on Monday focusing the best
forcing for ascent coincident with PWATs over 2". Considering the
rain some locations have gotten this week (5+ inches in localized
spots), while it doesn`t appear overly concerning WRT flooding it is
worth watching. There remains a question as to how long rain
lingers, potentially into Tuesday for some locations.

KEY MESSAGE 3...Drying and warming trend toward Wed/Thu.

Western Atlantic high pressure then builds west as mid level ridging
follows and we`ll see a drier and steadily warming period Wed/Thu.
This may be a brief respite before more unsettled weather on the
horizon.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

06z TAF Update:

Through 12Z: Moderate confidence.

Light northerly winds will continue to allow for MVFR stratus
with MVFR- IFR patchy fog developing through 12Z. 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.

Saturday...High confidence.

VFR. SW winds 5-10 kts.

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 Night through Tuesday/...

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 N/NW tonight as the low pressure just offshore continues
shifting into the Maritimes. Seas continue to diminish heading
into the weekend, 2-3 feet. Winds become lighter Friday and
shift more to the SW heading into Friday night and Saturday.
Fog expected to develop over much of the southern waters and off
the east coast of Cape Cod.

Outlook /Saturday Night through Tuesday/...

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...None.

&&

$$

DISCUSSION...BW
AVIATION...BW
MARINE...BW