376
FXUS61 KBOX 230024
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
824 PM EDT Fri Aug 22 2025

.SYNOPSIS...
Hurricane Erin will continue to bring high surf and dangerous
rip currents along with areas of coastal flooding and beach
erosion on east-facing beaches. Seasonable weather Saturday
with breezy conditions. Turning more unsettled for Sunday night
through Monday chances for showers and thunderstorms before dry
weather returns midweek.

&&

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

* Winds continue to decrease as Erin moves further out to sea.

* High surf, dangerous rip currents, coastal flooding, and the
  chance for beach erosion continue

No major changes to the forecast this evening. Main concern
remains minor coastal flooding from lingering rough seas and
surge from Post-Tropical Cyclone Erin.

Previous Discussion...

Erin continues to move northeast and away from Southern New
England this afternoon. Winds across the interior have calmed
but remain elevated across much of eastern Massachusetts and the
Islands where gusts up to 30 mph are still being reported as of
16z. In terms of wave action, the Block Island buoy still shows
wave heights between 8 and 10 feet, so significant coastal and
marine impacts continue even as the center of Erin moves further
out to sea. More details regarding coastal flooding and beach
erosion can be found in the coastal flooding section of this
discussion. Outside of marine impacts, it`s a pleasant and warm
day around the region as high pressure continues to build in
from the Great Lakes. Temperatures are running quite a bit
warmer than yesterday and most locations are in the upper 70s
and lower 80s.

Expecting winds to drop further for all locations overnight as
the lingering pressure gradient behind Erin further relaxes.
Clear skies and light winds will allow for decent radiational
cooling and most locations will likely cool into middle and
upper 50s except along the coast where lows will be closer to
the lower 60s.

&&

.SHORT TERM /SATURDAY NIGHT/...
Key Messages:

* Lingering coastal and marine threats from Erin will start to
  diminish Saturday night

* Seasonable temperatures with a breezy southwest wind

Another day of high surf, rip currents and areas of coastal
flooding on Saturday. Hazardous coastal conditions will start
to decrease Saturday night into Sunday as Erin continues to move
into the North Atlantic.

Southwesterly return flow behind departing high pressure brings
925mb temperatures up to +20C by Saturday afternoon. These
temperatures will support highs rising into the lower to middle
80s for all locations. Increasing pressure gradient between an
approaching disturbance and departing high pressure will promote
breezier conditions Saturday afternoon. Another calm night
Saturday night with increasing cloud cover ahead of a weak
front. Lows will be a bit warmer than Friday night as dew point
temperatures increase into the upper 50s and low 60s.

&&

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

* Lingering coastal and marine threats from Erin will continue
  to diminish Sunday

* More seasonably normal temperatures continue Sunday

* Unsettled conditions expected for the start of next week as a
  cold front approaches

High surf and dangerous rip currents will continue to decrease
Sunday as Erin continues to move into the North Atlantic.
Seasonable temperatures Sunday.

The pattern turns more unsettled late Sunday through Monday
night as a cold front approaches our region. Guidance continued
the trend of a slower frontal passage. Looking like most of
Sunday remains dry across most of southern New England. Showers
are expected Sunday night into Monday, with this front perhaps
reaching the coast by late Monday afternoon. Thunderstorms
remain possible, but need to see a little more support before
really gaining confidence in the details.

Otherwise, most of next week is looking dry as a large high
pressure from the central USA gradually moves east. Also looking
like slightly below normal temperatures prevail most of next
week behind the cold frontal passage.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

Tonight...High confidence.

VFR. Winds become light overnight, varying between S and W.

Saturday...High confidence.

VFR. Winds from the S/SSW up to 10 kts with occasional gusts
close to 20 kts over eastern MA.

Saturday Night...high confidence.

VFR.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday through Wednesday/...

Saturday Night through Sunday: VFR. Breezy.

Sunday Night: Mainly VFR, with local IFR possible. Breezy.
Chance SHRA, slight chance TSRA.

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

Monday Night: VFR. Slight chance SHRA.

Tuesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Saturday Night...High confidence.

Seas will continue to subside through Saturday down to more
Small Craft Advisory conditions. Seas on the outer waters will
be around 8 ft by tonight, then down to 5 ft in spots by
Saturday.

A High Surf Advisory remains in effect for southern coastal
areas, including the Cape and Islands. Waves will gradually
decrease Friday, though they will still be 10-15 ft offshore.
Rip currents will stay a significant concern with the elevated
surf through at least the first half of this weekend. High Surf
Advisories continue through Saturday evening.

Small Craft Advisories in effect for the lingering high seas
will gradually end this weekend, taking longest across the outer
coastal waters.

Outlook /Sunday through Wednesday/...

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas up to 5 ft.

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.

Sunday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.

Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers.

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

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

&&

.TIDES/COASTAL FLOODING...
Key Messages:

* Concern for beach and dune erosion shifts from south-facing
  beaches to the easterly facing beaches into tonight.

* Minor coastal flooding for Martha`s Vineyard, Nantucket, and
  MA/RI South Coast including Narragansett Bay with splash
  over to minor coastal flooding possible areas of the east MA
  coast.

Winds continue to decrease tonight with gusts diminishing by
late tonight. Minor coastal flooding will again be a threat
for the evening high tides for the Islands and south coast with
splash over to minor coastal flooding possible for areas of the
east coast. High surf and dangerous rip currents will also
continue to be a threat.

The concern for beach and dune erosion shifts from along south
facing ocean beaches decreases as the southerly swell energy
decreases into tonight as Erin pulls away further northeast.
However, with more energy orienting from an easterly component,
the concern for erosion then shifts to the easterly facing
beaches tonight into Saturday. Breaking waves on the ocean
beaches as high as 5-8 feet may result in beach and dune erosion
for areas of the easterly facing beaches/coastline and
splashover on vulnerable coastal roads during the high tide
tonight into Saturday.

Regarding coastal flooding, the high tides this evening when we
should see a storm surge of 1 to 2 feet (2 feet being the higher
end) may allow water levels to approach minor flood levels with
tonight`s for the South Coast. With the southerly swell
decreasing tonight, a reasonable worst case puts values just at
minor flood levels. Flooding should remain well within the Minor
category with flooding up to one foot deep confined to
vulnerable shore roads and low lying areas.

For Martha`s Vineyard and Nantucket, we expect a similar surge
of 1 to perhaps 2 feet during high tides late tonight and late
Friday night. Minor coastal flooding (up to one foot deep)
should occur in the more vulnerable sections of Nantucket
Harbor, Edgartown Harbor, Vineyard Haven, and Oak Bluffs around
high tide.

Along the E MA coast including Cape Cod, no significant coastal
flooding is expected but water levels could reach Action stage
due storm surge of 1 to 1.5 ft combined with somewhat high
astronomical tides. Coastal Flood Statements will be in effect
for the east MA coast for this evening`s high tide.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Surf Advisory until 8 PM EDT Saturday for MAZ007-019>024.
     Coastal Flood Advisory until 10 PM EDT this evening for MAZ020.
     Coastal Flood Advisory until 2 AM EDT Saturday for MAZ023-024.
RI...High Surf Advisory until 8 PM EDT Saturday for RIZ006>008.
     Coastal Flood Advisory until 10 PM EDT this evening for RIZ002-
     004>008.
MARINE...Small Craft Advisory until 1 AM EDT Saturday for ANZ231.
     Small Craft Advisory until 7 PM EDT Saturday for ANZ232.
     Small Craft Advisory until 7 AM EDT Saturday for ANZ233-235-
     237.
     Small Craft Advisory until 8 PM EDT Sunday for ANZ250-254>256.
     Small Craft Advisory until 7 AM EDT Sunday for ANZ251.

&&

$$

SYNOPSIS...Belk/Hrencecin/Mensch
NEAR TERM...Belk/FT
SHORT TERM...FT
LONG TERM...FT
AVIATION...Belk/FT
MARINE...Belk/Hrencecin/Mensch
TIDES/COASTAL FLOODING...Mensch/JWD