507
FXUS61 KBOX 230756
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
356 AM EDT Sat Aug 23 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 as chances for showers and thunderstorms before
dry weather returns midweek.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages:

* High surf and dangerous rip currents remain a threat today while
  the risk for coastal flooding comes to an end

* Seasonable temperatures with breezy southwest winds

High surf and dangerous rip currents from Erin`s passage linger
through today before diminishing tonight. Headlines for coastal
flooding have been allowed to expire as the risk has diminished
following the overnight high tides. Along east-facing beaches the
risk for beach erosion does remain with lingering easterly swell.
See the tides/coastal flooding section of this discussion for more
information.

Aside from the continued rough seas, a calm and dry day with mostly
clear skies is ahead. Breezy southwest winds associated with passing
surface high pressure to the east will continue through the day.
This southwest flow will aid in advecting in 925 mb temperatures
around 20C, which will mix down during the day. Seasonable
temperatures with highs in the 80s and dew points in the mid 50s to
low 60s are expected.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Key Messages:

* Dangerous coastal conditions should subside heading into Sunday

* Another mostly quiet day ahead of the next chance for
  showers/storms

Southwest winds shift more southerly and decrease heading into
tonight. Lows settle in the low 60s for most, with mid 60s expected
over the urban centers, Cape Cod, and the Islands.

High surf and dangerous rip currents are expected to continue to
decrease for Sunday as Erin and its influence continue to move far
off into the North Atlantic. Seasonable temperatures again expected
for Sunday with breezy southerly winds ahead of the next cold front
expected to move through the region. Most of southern New England
should remain dry through Sunday ahead of an approaching cold front
from the west.

&&

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

* Showers and possibly some thunderstorms possible heading into
  Monday, continuing through the afternoon and evening

* Following the cold frontal passage to start the week, temperatures
  may remain slightly below normal through the week

As the coastal threats continue to decrease and end heading into
Sunday night, we turn our attention to the next chance for unsettled
weather across southern New England.

A cold front approaches the region Sunday night heading into
Monday leading to the next chance for showers and storms.
Guidance is continuing to indicate that this front may end up
stalling over the Mid Atlantic before moving towards southern
New England Sunday night, then through the region Monday.
Ensembles continue to hint at the chance for some thunderstorms
with some instability over the region Monday afternoon, but
confidence still remains low. Probabilities for 0-6 km shear >=
40 kts are greatest heading into Monday evening just before
sunset over western MA into CT, though probs for favorable CAPE
values aren`t very high. At this time, if any storms do develop,
they are likely to be sub-severe as peak heating, instability,
and wind shear are not appearing to align at the same time.
These details will be ironed out more in coming forecasts as
higher resolution guidance will start to reach this time period.

High pressure returns following the cold front`s passage, leading to
a more quiet week. Temperatures dip into slightly below normal
values as a cooler post-frontal airmass remains over the region.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

06z Update

Through 12z...High confidence.

VFR. Winds remain 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 mainly over eastern MA. Some interior terminals
may also see an occasional gust close to 20 kts in the late
afternoon hours.

Saturday Night...High confidence.

VFR. Winds mainly from the S decreasing to around 5 kts.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Wednesday/...

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

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

Monday Night: VFR. Slight chance SHRA.

Tuesday: VFR. Breezy.

Tuesday Night through Wednesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Sunday...High confidence.

Seas will continue to subside through today 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 continue to
decrease through the day today, though offshore they remain 6-8
ft at the start of the day. 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 this
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 Night through Wednesday/...

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

Monday Night: Winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers.

Tuesday through Wednesday: Winds less than 25 kt. Areas of seas
approaching 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.

High surf and dangerous rip currents will continue to be a
threat across all coastlines.

The concern for beach and dune erosion shifts from along south
facing ocean beaches decreases as the southerly swell energy
decreases 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 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 into Saturday.

Regarding coastal flooding, all headlines have been allowed to
expire as the Friday evening high tide cycles have ended.

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.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Surf Advisory until 8 PM EDT this evening for MAZ007-
     019>024.
RI...High Surf Advisory until 8 PM EDT this evening for RIZ006>008.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ232.
     Small Craft Advisory until 7 AM EDT this morning 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...Hrencecin
SHORT TERM...Hrencecin
LONG TERM...Hrencecin
AVIATION...Hrencecin
MARINE...Hrencecin
TIDES/COASTAL FLOODING...Hrencecin/JWD