969
FXUS61 KBOX 242338
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
738 PM EDT Sun Aug 24 2025

.SYNOPSIS...
Dry most of tonight, will have showers across Cape Cod and the
Islands on Monday morning with the passage of a low pressure system.
Scattered storms return Monday afternoon with an approaching cold
front. Dry conditions favored with surface high pressure in place
through the end of the week while also trending cooler with
temperatures slightly below normal.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Key Messages:

* Gusty wind subsides late afternoon, increasing clouds with a low
  chance of a rouge storm in western Massachusetts this afternoon
  and early evening.

* Weak low pressure system passes east of Cape Cod late tonight
  which bring rain showers to Cape Cod, Martha`s Vineyard, and
  Nantucket.

Increasing cloud cover this afternoon ahead of an approaching cold
front located in western New York. Ahead of the front, isolated rain
and thunderstorms. The CAMs have been in good agreement that the
activity will remain to the west of our region, with the exception
of far northwest Massachusetts. Otherwise, it is a dry evening. Will
have wind gust easing around sunset, as the boundary layer decouples
with light to calm conditions overnight. Not expecting a radiational
cooling night with abundant cloud cover, lows fall into the mid-60s.

A weak low pressure will move up the coast overnight, passing to the
east of Cape Cod, with the best chance of appreciable rain on
Nantucket and perhaps the outer most of Cape Cod. Consensus of the
guidance has rain arriving during the predawn hours and exiting by
mid to late morning.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Key Messages:

* Chance for scattered storms afternoon into the early evening as a
  cold front moves across the region.

Low pressure system moves north into the Gulf of Maine with a cold
front approaching slowly from the west. This is associated with the
500mb closed low over James Bay in Canada and trough extending south
into the Great Lakes. Locally, will have low clouds lingering into
the early afternoon, with seasonable temperatures on either side of
80 degrees. Also, the lack of full sun likely reduces the amount of
time for destabilization and should keep the threat for any severe
weather to a minimum. HREF mean values of CAPE are largely 500-800
J/kg, there is decent effective shear 35-40 knots, but the struggle
will be timing of the best forcing. Storms should remain scattered
during the late afternoon and early evening. But, given the time of
year with the earlier sunsets, storms that do fire up will struggle
to continue past sunset.

Clearing skies in the wake of the cold front overnight, though think
the winds will remain elevated enough to ward off a night of true
radiational cooling. Nevertheless, lows Monday night fall into the
50s. Patchy fog develops overnight in the river valleys and in areas
that received rain.

&&

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

* Dry and cooler for most of the week.

A cooler airmass settles into southern New England Tuesday with
highs in the mid to upper 70s through the remainder of the week.
High pressure builds over the Midwest and Mid-Atlantic region,
bringing mostly clear and dry conditions. A cold front dropping down
into northern New England from Canada late Thursday/early Friday
could bring a slight chance for spotty showers across the interior,
but details such as exact timing, rainfall intensity, and QPF
amounts are still unclear at this time.

&&

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

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

00z Update...

Through Tonight...Moderate confidence.

Have a SCT to BKN deck of low-end VFR clouds across the region.
Starting to see gusts subsiding, along with a shift in the wind
to the SSE and ESE for the eastern terminals. Overnight cigs
lower to MVFR and areas of IFR, have lower confidence in how
widespread the IFR ceilings become. A weak low pressure system
brings rain chance mainly to South Coast, Cape & Islands early
Monday morning.

Monday...Moderate Confidence.

MVFR and IFR early, becoming VFR late, 15z-18z. A weak cold
front will push through the region late in the day and could
bring a spot shower or thunderstorm, low confidence in this part
of the forecast, opt`d to leave out of the TAF. Wind shifts to
the SSW Monday morning, becoming WSW and then W during the
afternoon with speeds 8-12 knots.

Monday Night...High Confidence.

Cold front clears the coast late night and leads to clearing
skies and VFR conditions. WNW wind 5-10 knots.

KBOS Terminal...Moderate confidence in TAF.

Low-end VFR cigs fall overnight. Moderate confidence in IFR
conditions, but cannot rule out LIFR. Mainly a dry night, but a
low pressure system passing east of the terminal could lead to a
spotty shower during the Monday morning push. Low-end VFR cigs
Monday with a low chance for a pop-up thunderstorm in the late
afternoon, after 20z, but not confident enough to include in TAF
at this time.

KBDL Terminal...High confidence in TAF.

Outlook /Tuesday through Friday/...

Tuesday: VFR. Breezy.

Tuesday Night through Wednesday Night: VFR.

Thursday: VFR. Breezy.

Thursday Night: VFR.

Friday: VFR. Slight chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through tonight...High Confidence.

Elevated seas on the outer waters of 4 to 6 feet, have extended the
Small Craft Advisory through 2 AM. The second-half of the night seas
are less than 5 feet on the outer waters and 2-3 feet near shore.

Monday and Monday Night...High Confidence.

Area of low pressure moves up the coast, increasing waves and brings
rain showers mainly to the eastern waters through late Monday
morning. A cold front moves across the waters from west to east late
Monday afternoon through Monday night. A isolated shower or two is
possible during this time. Seas are building 5 to 6 feet across the
outer waters before diminishing Tuesday. Likely will need another
Small Craft Advisory for this period.

Outlook /Tuesday through Friday/...

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

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

Wednesday through Thursday Night: Winds less than 25 kt.

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Risk for Rip Currents until 8 PM EDT this evening for MAZ007-
     019>024.
RI...High Risk for Rip Currents until 8 PM EDT this evening for
     RIZ006>008.
MARINE...Small Craft Advisory until 2 AM EDT Monday for ANZ250-254>256.
     Small Craft Advisory until 10 PM EDT this evening for ANZ251.

&&

$$

SYNOPSIS...Dooley/McMinn
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...McMinn
AVIATION...Dooley/McMinn/KP
MARINE...Dooley/McMinn