Coastal Waters Forecast
Issued by NWS Boston, MA

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FZUS51 KBOX 140504
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
104 AM EDT Thu Aug 14 2025

Coastal waters from the Merrimack River MA to Watch Hill RI out
to 25 NM

ANZ200-141800-
104 AM EDT Thu Aug 14 2025

.Synopsis for Massachusetts and Rhode Island coastal waters...
Scattered showers possible on Thursday. A cold front will cross the
waters Thu night into Fri. High pressure return Friday into the
weekend.

$$

ANZ250-141800-
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: SW 3 ft at 4 seconds and E 2 ft at
7 seconds. A slight chance of showers.
.THU...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft
at 4 seconds and E 2 ft at 7 seconds.
.THU NIGHT...NW winds 5 to 10 kt, becoming N 10 to 15 kt with
gusts up to 20 kt after midnight. Seas 2 to 3 ft. Wave Detail: E
3 ft at 7 seconds and SW 2 ft at 3 seconds.
.FRI...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
4 ft. Wave Detail: NE 4 ft at 5 seconds and S 1 foot at
4 seconds.
.FRI NIGHT...NE winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: NE
3 ft at 6 seconds and E 1 foot at 15 seconds.
.SAT AND SAT NIGHT...S winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: S 2 ft at 3 seconds and NE 2 ft at
6 seconds.
.SUN...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to
3 ft.
.SUN NIGHT...W winds 15 to 20 kt with gusts up to 25 kt. Seas
around 3 ft. A chance of showers.
.MON AND MON NIGHT...NE winds 15 to 20 kt with gusts up to 25 kt,
becoming E 5 to 10 kt. Seas 3 to 5 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ251-141800-
Massachusetts Bay and Ipswich Bay-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 3 seconds and E 2 ft at 7 seconds.
.THU...SW winds 5 to 10 kt, becoming SE in the afternoon. Seas
around 2 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at
7 seconds. A chance of showers in the afternoon.
.THU NIGHT...NE winds 5 to 10 kt, becoming N 10 to 15 kt with
gusts up to 20 kt after midnight. Seas around 2 ft. Wave Detail:
SE 2 ft at 6 seconds and S 1 foot at 3 seconds.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 3 ft at 5 seconds and E 1 foot at
16 seconds.
.FRI NIGHT...NE winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: NE
3 ft at 6 seconds and E 1 foot at 15 seconds.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: S 2 ft at 3 seconds and NE 2 ft at 6 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft.
.SUN NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas
2 to 3 ft. A chance of showers.
.MON AND MON NIGHT...NE winds 15 to 20 kt with gusts up to 25 kt,
becoming E 5 to 10 kt. Seas 2 to 3 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ231-141800-
Cape Cod Bay-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 10 to 15 kt. Seas around 2 ft. Wave
Detail: SW 1 foot at 3 seconds and E 1 foot at 7 seconds. A
slight chance of showers and tstms. Vsby 1 to 3 NM.
.THU...S winds 5 to 10 kt. Seas around 2 ft in the morning, then
1 foot or less. Wave Detail: SW 1 foot at 2 seconds and E 1 foot
at 7 seconds, becoming S 1 foot at 2 seconds and E 1 foot at
7 seconds. Patchy fog in the morning. A chance of showers in the
afternoon. Vsby 1 to 3 NM in the morning.
.THU NIGHT...SW winds around 5 kt, becoming N after midnight.
Seas 1 foot or less, then around 2 ft after midnight. Wave
Detail: SW 1 foot at 2 seconds and E 1 foot at 7 seconds,
becoming NW 1 foot at 3 seconds and E 1 foot at 7 seconds.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: N 2 ft at 4 seconds and E 1 foot at
16 seconds.
.FRI NIGHT AND SAT...E winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: N 2 ft at 5 seconds and SE 1 foot at 15 seconds.
.SAT NIGHT...S winds 5 to 10 kt. Seas around 2 ft. Wave Detail:
SE 1 foot at 4 seconds and E 1 foot at 15 seconds.
.SUN...SW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
4 ft.
.SUN NIGHT...SW winds around 15 kt with gusts up to 25 kt. Seas
2 to 4 ft. A chance of showers.
.MON AND MON NIGHT...NE winds 15 to 20 kt with gusts up to 25 kt,
diminishing to 5 to 10 kt. Seas 2 to 4 ft.

Winds and seas higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ254-141800-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: S 2 ft at 4 seconds and E 2 ft at
8 seconds. A slight chance of showers.
.THU...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at
4 seconds and E 2 ft at 8 seconds. Patchy fog. Vsby 1 to 3 NM,
decreasing to 1 NM or less in the afternoon.
.THU NIGHT...S winds around 5 kt, becoming N after midnight. Seas
around 2 ft. Wave Detail: SW 2 ft at 4 seconds and SE 2 ft at
8 seconds. Patchy fog. Vsby 1 to 3 NM, decreasing to 1 NM or less
after midnight.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
4 ft. Wave Detail: NE 3 ft at 6 seconds and S 1 foot at
5 seconds. Patchy fog in the morning with vsby 1 NM or less.
.FRI NIGHT AND SAT...E winds 10 to 15 kt. Seas 2 to 4 ft. Wave
Detail: NE 3 ft at 6 seconds and S 1 foot at 6 seconds.
.SAT NIGHT...SE winds 5 to 10 kt, becoming S after midnight. Seas
2 to 3 ft. Wave Detail: SE 3 ft at 6 seconds and SE 1 foot at
15 seconds.
.SUN...SW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
3 ft.
.SUN NIGHT...SW winds around 15 kt with gusts up to 25 kt. Seas
around 3 ft. A chance of showers.
.MON AND MON NIGHT...NE winds 10 to 15 kt with gusts up to 25 kt.
Seas 3 to 4 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ255-141800-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas 2 to 3 ft. Wave
Detail: SW 2 ft at 4 seconds and E 2 ft at 8 seconds. Patchy fog.
A chance of showers. Vsby 1 to 3 NM.
.THU...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft
at 4 seconds and E 2 ft at 8 seconds. Patchy fog. A chance of
showers in the afternoon. Vsby 1 NM or less.
.THU NIGHT...S winds around 5 kt, becoming N after midnight. Seas
around 2 ft. Wave Detail: SW 2 ft at 4 seconds and SE 2 ft at
8 seconds. Patchy fog. Vsby 1 NM or less.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 3 ft at 5 seconds and SW 2 ft at 6 seconds.
Patchy fog in the morning with vsby 1 to 3 NM.
.FRI NIGHT AND SAT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: NE 3 ft at 5 seconds and S 1 foot at
6 seconds.
.SAT NIGHT...SE winds 5 to 10 kt, becoming S after midnight. Seas
2 to 3 ft. Wave Detail: SE 2 ft at 6 seconds and SE 1 foot at
15 seconds.
.SUN THROUGH MON NIGHT...NE winds 15 to 20 kt. Seas 2 to 4 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ256-141800-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas 2 to 3 ft. Wave
Detail: SW 2 ft at 4 seconds and E 2 ft at 8 seconds. Patchy fog.
A chance of showers with a slight chance of tstms. Vsby 1 NM or
less.
.THU...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft
at 4 seconds and E 2 ft at 8 seconds. Patchy fog. A chance of
showers. Vsby 1 NM or less, increasing to 1 to 3 NM in the
afternoon.
.THU NIGHT...S winds around 5 kt, becoming N after midnight. Seas
around 2 ft. Wave Detail: SW 2 ft at 5 seconds and SE 2 ft at
8 seconds. Patchy fog. Vsby 1 NM or less.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 3 ft at 5 seconds and S 1 foot at
6 seconds. Patchy fog in the morning with vsby 1 to 3 NM.
.FRI NIGHT AND SAT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: NE 3 ft at 5 seconds and S 1 foot at
6 seconds.
.SAT NIGHT...SE winds 5 to 10 kt, becoming S after midnight. Seas
2 to 3 ft. Wave Detail: SE 3 ft at 6 seconds and SE 1 foot at
13 seconds.
.SUN THROUGH MON NIGHT...E winds 15 to 20 kt. Seas 2 to 4 ft.

Winds and seas higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ232-141800-
Nantucket Sound-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 10 to 15 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 3 seconds and E 1 foot at 7 seconds. Patchy
fog. A slight chance of showers. Vsby 1 to 3 NM.
.THU...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SW
2 ft at 3 seconds and E 1 foot at 7 seconds. Patchy fog in the
morning. A chance of showers in the afternoon. Vsby 1 to 3 NM.
.THU NIGHT...SW winds 5 to 10 kt, becoming N 10 to 15 kt after
midnight. Seas around 2 ft. Wave Detail: SW 1 foot at 3 seconds
and E 1 foot at 7 seconds. Patchy fog. Vsby 1 to 3 NM.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas around
2 ft. Wave Detail: NE 2 ft at 3 seconds and SW 1 foot at
5 seconds.
.FRI NIGHT AND SAT...E winds 10 to 15 kt. Seas around 2 ft. Wave
Detail: NE 2 ft at 4 seconds and S 1 foot at 5 seconds.
.SAT NIGHT...SE winds 5 to 10 kt, becoming S after midnight. Seas
around 2 ft. Wave Detail: SE 1 foot at 5 seconds and SE 1 foot at
15 seconds.
.SUN THROUGH MON NIGHT...NE winds 15 to 20 kt. Seas 2 to 3 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ233-141800-
Vineyard Sound-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 4 seconds and SE 1 foot at 8 seconds. Patchy
fog. A chance of showers with a slight chance of tstms. Vsby 1 NM
or less.
.THU...SW winds around 10 kt. Seas around 2 ft. Wave Detail: SW
2 ft at 4 seconds and SE 1 foot at 8 seconds. Patchy fog. A
chance of showers in the afternoon. Vsby 1 NM or less, increasing
to 1 to 3 NM in the afternoon.
.THU NIGHT...SW winds around 5 kt, becoming N after midnight.
Seas 1 foot or less, then around 2 ft after midnight. Wave
Detail: SW 1 foot at 4 seconds and SE 1 foot at 8 seconds,
becoming W 1 foot at 4 seconds and E 1 foot at 8 seconds. Patchy
fog. Vsby 1 to 3 NM, decreasing to 1 NM or less after midnight.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas around
2 ft. Wave Detail: NE 2 ft at 3 seconds and SW 1 foot at
5 seconds.
.FRI NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt,
diminishing to 5 to 10 kt after midnight. Seas around 2 ft. Wave
Detail: NE 2 ft at 3 seconds and S 1 foot at 6 seconds.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: NE 1 foot at 3 seconds and S 1 foot at 5 seconds.
.SUN THROUGH MON NIGHT...NE winds 15 to 20 kt. Seas 2 to 3 ft.

Winds and seas higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ234-141800-
Buzzards Bay-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 4 seconds and SE 1 foot at 8 seconds. Patchy
fog. A slight chance of showers. Vsby 1 NM or less.
.THU...SW winds 5 to 10 kt. Seas around 2 ft in the morning, then
1 foot or less. Wave Detail: SW 1 foot at 4 seconds and SE 1 foot
at 8 seconds. Patchy fog. A chance of showers in the afternoon.
Vsby 1 NM or less, increasing to 1 to 3 NM in the afternoon.
.THU NIGHT...SW winds 5 to 10 kt, becoming N after midnight. Seas
1 foot or less, then around 2 ft after midnight. Wave Detail: SW
1 foot at 4 seconds and SE 1 foot at 8 seconds, becoming W 1 foot
at 4 seconds and E 1 foot at 8 seconds. Patchy fog. Vsby 1 to
3 NM, decreasing to 1 NM or less after midnight.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 2 ft at 3 seconds and SW 1 foot at
5 seconds.
.FRI NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt,
diminishing to 5 to 10 kt after midnight. Seas around 2 ft. Wave
Detail: NE 2 ft at 3 seconds and S 1 foot at 5 seconds.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: NE 1 foot at 2 seconds and S 1 foot at 5 seconds.
.SUN THROUGH MON...NE winds 15 to 20 kt with gusts up to 25 kt.
Seas 2 to 4 ft.
.MON NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt. Seas
around 2 ft.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ235-141800-
Rhode Island Sound-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds around 10 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 4 seconds and SE 1 foot at 8 seconds. Patchy
fog. A slight chance of showers and tstms. Vsby 1 NM or less.
.THU...S winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SW 2 ft
at 4 seconds and SE 1 foot at 9 seconds. Patchy fog. A chance of
showers in the afternoon. Vsby 1 NM or less, increasing to 1 to
3 NM in the afternoon.
.THU NIGHT...S winds around 5 kt, becoming N after midnight. Seas
around 2 ft. Wave Detail: SE 2 ft at 9 seconds and S 1 foot at
4 seconds. Patchy fog. Vsby 1 to 3 NM, decreasing to 1 NM or less
after midnight.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 3 ft at 5 seconds and S 1 foot at
5 seconds.
.FRI NIGHT...NE winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 2 to 3 ft. Wave Detail: E 3 ft at 5 seconds and S
1 foot at 6 seconds.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: NE 2 ft at 5 seconds and S 1 foot at 5 seconds.
.SUN THROUGH MON NIGHT...E winds 15 to 20 kt. Seas 2 to 3 ft.

Winds and seas higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ237-141800-
Block Island Sound-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: SW 2 ft at 4 seconds and SE 1 foot at 8 seconds. Patchy
fog. A chance of showers with a slight chance of tstms. Vsby 1 to
3 NM.
.THU...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SW
2 ft at 4 seconds and SE 1 foot at 8 seconds. A chance of
showers. Patchy fog in the morning with vsby 1 to 3 NM.
.THU NIGHT...S winds around 5 kt, becoming N after midnight. Seas
around 2 ft. Wave Detail: E 2 ft at 9 seconds and SW 1 foot at
4 seconds.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: NE 2 ft at 6 seconds and S 1 foot at
5 seconds.
.FRI NIGHT...E winds 10 to 15 kt with gusts up to 20 kt, becoming
NE 5 to 10 kt after midnight. Seas 2 to 3 ft. Wave Detail: E 2 ft
at 5 seconds and S 1 foot at 6 seconds.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: E 2 ft at 5 seconds and S 1 foot at 5 seconds.
.SUN THROUGH MON NIGHT...E winds 10 to 15 kt with gusts up to
20 kt. Seas 2 to 3 ft.

Winds and seas higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ230-141800-
Boston Harbor-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 5 to 10 kt. Waves 1 foot or less.
.THU...SW winds 5 to 10 kt, becoming SE in the afternoon. Waves
1 foot or less. A chance of showers and tstms in the afternoon.
.THU NIGHT...NE winds 5 to 10 kt, becoming N 10 to 15 kt after
midnight. Waves 1 foot or less, then around 2 ft after midnight.
.FRI...NE winds 10 to 15 kt with gusts up to 20 kt. Waves around
2 ft.
.FRI NIGHT...NE winds 5 to 10 kt. Waves around 2 ft in the
evening, then 1 foot or less.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Waves around 2 ft.
.SUN...SW winds 10 to 15 kt with gusts up to 20 kt. Waves around
2 ft.
.SUN NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Waves
around 2 ft. A chance of showers.
.MON AND MON NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt,
becoming E 5 to 10 kt. Waves around 2 ft.

Winds and waves higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

ANZ236-141800-
Narragansett Bay-
104 AM EDT Thu Aug 14 2025

.REST OF TONIGHT...SW winds 5 to 10 kt. Waves around 2 ft. Patchy
fog. A slight chance of showers. Vsby 1 to 3 NM.
.THU...S winds 5 to 10 kt. Waves around 2 ft in the morning, then
1 foot or less. Patchy fog in the morning. A chance of showers
and tstms in the afternoon. Vsby 1 to 3 NM in the morning.
.THU NIGHT...SE winds around 5 kt, becoming N after midnight.
Waves 1 foot or less.
.FRI...NE winds 10 to 15 kt. Waves around 2 ft.
.FRI NIGHT...NE winds 5 to 10 kt. Waves around 2 ft.
.SAT AND SAT NIGHT...SW winds 5 to 10 kt. Waves around 2 ft.
.SUN THROUGH MON NIGHT...NE winds 10 to 15 kt with gusts up to
20 kt. Waves 2 to 3 ft.

Winds and waves higher in and near tstms.

Seas are reported as significant wave height, which is the
average of the highest third of the waves. Individual wave
heights may be more than twice the significant wave height.

$$

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