523
FZUS51 KBOX 172003
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
402 PM EDT Thu Apr 17 2025

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

ANZ200-180900-
402 PM EDT Thu Apr 17 2025

.Synopsis for Massachusetts and Rhode Island coastal waters...
High pressure builds over the waters tonight and moves offshore
Friday. A cold front will cross the waters late Saturday night.
Another high pressure builds over the region for Monday.

$$

ANZ250-180900-
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt. Seas around 2 ft. Wave Detail: NW
2 ft at 3 seconds and SE 1 foot at 9 seconds.
.FRI...SW winds 5 to 10 kt, becoming S 15 to 20 kt with gusts up
to 25 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: S 3 ft at
4 seconds and SE 1 foot at 8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 30 kt. Seas
3 to 5 ft. Wave Detail: S 4 ft at 4 seconds and SE 2 ft at
8 seconds. A chance of rain after midnight.
.SAT...SW winds around 20 kt with gusts up to 30 kt. Seas 4 to
6 ft. Wave Detail: S 4 ft at 6 seconds. A chance of rain in the
morning.
.SAT NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
4 to 6 ft. Wave Detail: SW 3 ft at 5 seconds and SE 3 ft at
8 seconds.
.SUN AND SUN NIGHT...NW winds 15 to 20 kt with gusts up to 25 kt.
Seas 2 to 4 ft. Wave Detail: W 3 ft at 4 seconds and SE 2 ft at
8 seconds.
.MON...NE winds 5 to 10 kt. Seas 2 to 3 ft.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 4 ft. A chance of showers.

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.

$$

ANZ251-180900-
Massachusetts Bay and Ipswich Bay-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt. Seas 1 foot or less. Wave Detail:
NW 1 foot at 3 seconds and E 1 foot at 9 seconds.
.FRI...SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up
to 20 kt in the afternoon. Seas 1 foot or less, then around 2 ft
in the afternoon. Wave Detail: W 1 foot at 2 seconds and E 1 foot
at 7 seconds, becoming S 2 ft at 3 seconds and E 1 foot at
8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
2 to 3 ft. Wave Detail: S 3 ft at 3 seconds and SE 2 ft at
8 seconds. A chance of rain after midnight.
.SAT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to
3 ft. Wave Detail: SW 2 ft at 4 seconds and SE 2 ft at 7 seconds.
A chance of rain in the morning.
.SAT NIGHT THROUGH SUN NIGHT...NW winds 15 to 20 kt with gusts up
to 25 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and
SE 1 foot at 8 seconds.
.MON...NE winds 5 to 10 kt. Seas around 2 ft. Wave Detail: NW
1 foot at 3 seconds and NE 1 foot at 6 seconds.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 3 ft. A chance of showers.

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.

$$

ANZ231-180900-
Cape Cod Bay-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt. Seas 1 foot or less. Wave Detail:
NW 1 foot at 4 seconds and SE 1 foot at 6 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: NW 1 foot at 3 seconds,
becoming SW 2 ft at 3 seconds and SE 1 foot at 6 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
2 to 4 ft. Wave Detail: S 3 ft at 5 seconds.
.SAT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 3 to
4 ft. Wave Detail: SW 3 ft at 4 seconds and S 2 ft at 8 seconds.
.SAT NIGHT...SW winds 15 to 20 kt, becoming W 10 to 15 kt after
midnight. Gusts up to 25 kt. Seas 2 to 4 ft. Wave Detail: SW 3 ft
at 4 seconds and S 2 ft at 8 seconds.
.SUN AND SUN NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: NW 2 ft at 4 seconds and S 2 ft at
8 seconds.
.MON...NE winds 5 to 10 kt. Seas around 2 ft.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas around 2 ft. A chance of showers.

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.

$$

ANZ254-180900-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt with gusts up to 20 kt,
diminishing to around 5 kt after midnight. Seas 2 to 4 ft. Wave
Detail: W 2 ft at 4 seconds and S 2 ft at 8 seconds.
.FRI...W winds 5 to 10 kt, becoming SW 10 to 15 kt with gusts up
to 20 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: SW 2 ft
at 4 seconds and S 2 ft at 8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 30 kt. Seas
2 to 4 ft, building to 4 to 6 ft after midnight. Wave Detail: S
3 ft at 4 seconds and S 1 foot at 8 seconds, becoming S 5 ft at
5 seconds and SE 1 foot at 8 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to
8 ft. Wave Detail: SW 7 ft at 7 seconds.
.SAT NIGHT...SW winds 20 to 25 kt, becoming W 15 to 20 kt after
midnight. Seas 5 to 8 ft. Wave Detail: S 6 ft at 8 seconds and W
2 ft at 4 seconds.
.SUN...W winds 10 to 15 kt with gusts up to 20 kt. Seas 4 to
6 ft. Wave Detail: S 4 ft at 8 seconds and W 3 ft at 4 seconds.
.SUN NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt. Seas
3 to 5 ft.
.MON...N winds 5 to 10 kt. Seas 2 to 4 ft.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 4 ft. A chance of showers.

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.

$$

ANZ255-180900-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
402 PM EDT Thu Apr 17 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 PM EDT THIS EVENING...

.TONIGHT...W winds 15 to 20 kt, diminishing to 5 to 10 kt after
midnight. Seas 2 to 4 ft. Wave Detail: SW 4 ft at 5 seconds and S
2 ft at 8 seconds.
.FRI...W winds 5 to 10 kt, becoming SW 10 to 15 kt with gusts up
to 20 kt in the afternoon. Seas around 2 ft. Wave Detail: SW 2 ft
at 6 seconds.
.FRI NIGHT...SW winds 15 to 20 kt, increasing to 20 to 25 kt
after midnight. Gusts up to 30 kt. Seas 2 to 4 ft, building to
4 to 6 ft after midnight. Wave Detail: SW 4 ft at 5 seconds and S
1 foot at 8 seconds, becoming SW 6 ft at 6 seconds and SE 1 foot
at 9 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to
8 ft. Wave Detail: SW 8 ft at 7 seconds.
.SAT NIGHT AND SUN...W winds 20 to 25 kt with gusts up to 30 kt.
Seas 5 to 7 ft. Wave Detail: SW 7 ft at 8 seconds and SW 1 foot
at 4 seconds.
.SUN NIGHT...NW winds 10 to 15 kt. Seas 3 to 5 ft. Wave Detail:
SW 5 ft at 8 seconds and NW 1 foot at 4 seconds.
.MON...NE winds 5 to 10 kt. Seas 2 to 4 ft.
.MON NIGHT...S winds 10 to 15 kt. Seas 2 to 3 ft. A chance of
showers.
.TUE AND TUE NIGHT...S winds around 15 kt, becoming W. Gusts up
to 20 kt. Seas 3 to 5 ft. A chance of showers.

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.

$$

ANZ256-180900-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt with gusts up to 20 kt,
diminishing to 5 to 10 kt after midnight. Seas 2 to 4 ft. Wave
Detail: SW 3 ft at 5 seconds and S 2 ft at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: SW
2 ft at 5 seconds and S 1 foot at 8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt, increasing to 20 to 25 kt
after midnight. Gusts up to 30 kt. Seas 2 to 4 ft, building to
4 to 6 ft after midnight. Wave Detail: SW 4 ft at 5 seconds and
SE 1 foot at 8 seconds, becoming S 6 ft at 7 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 6 to
8 ft. Wave Detail: SW 8 ft at 6 seconds.
.SAT NIGHT AND SUN...W winds 20 to 25 kt with gusts up to 30 kt.
Seas 5 to 7 ft. Wave Detail: SW 7 ft at 8 seconds and SW 1 foot
at 4 seconds.
.SUN NIGHT...NW winds 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: S
5 ft at 8 seconds and NW 1 foot at 3 seconds.
.MON...E winds 5 to 10 kt. Seas 2 to 3 ft.
.MON NIGHT AND TUE...S winds 10 to 15 kt. Gusts up to 20 kt. Seas
2 to 4 ft. A chance of showers.
.TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 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.

$$

ANZ232-180900-
Nantucket Sound-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt with gusts up to 20 kt,
diminishing to around 5 kt after midnight. Seas 2 to 3 ft. Wave
Detail: W 2 ft at 4 seconds and S 1 foot at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: SW 1 foot at 5 seconds and S
1 foot at 8 seconds, becoming SW 2 ft at 3 seconds and S 1 foot
at 8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 30 kt. Seas
2 to 4 ft. Wave Detail: SW 3 ft at 4 seconds and SE 1 foot at
8 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to
5 ft. Wave Detail: SW 4 ft at 4 seconds and S 3 ft at 7 seconds.
.SAT NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
3 to 5 ft. Wave Detail: SW 4 ft at 4 seconds and S 2 ft at
8 seconds.
.SUN AND SUN NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: W 2 ft at 3 seconds and S 2 ft at
8 seconds.
.MON...NE winds 5 to 10 kt. Seas around 2 ft.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 3 ft. A chance of showers.

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.

$$

ANZ233-180900-
Vineyard Sound-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt with gusts up to 20 kt,
diminishing to around 5 kt after midnight. Seas 2 to 3 ft. Wave
Detail: SW 2 ft at 5 seconds and S 1 foot at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: SW 1 foot at 6 seconds,
becoming SW 2 ft at 4 seconds and S 1 foot at 7 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
2 to 4 ft. Wave Detail: SW 4 ft at 6 seconds and SE 2 ft at
9 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to
6 ft. Wave Detail: SW 6 ft at 7 seconds.
.SAT NIGHT...SW winds 20 to 25 kt, becoming W 15 to 20 kt after
midnight. Seas 4 to 6 ft. Wave Detail: SW 6 ft at 8 seconds and
SW 2 ft at 4 seconds.
.SUN AND SUN NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 4 ft. Wave Detail: SW 4 ft at 8 seconds and W 1 foot at
4 seconds.
.MON...SE winds 5 to 10 kt. Seas 1 foot or less.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 3 ft. A chance of showers.

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.

$$

ANZ234-180900-
Buzzards Bay-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt, diminishing to around 5 kt after
midnight. Seas around 2 ft this evening, then 1 foot or less.
Wave Detail: SW 2 ft at 4 seconds and S 1 foot at 8 seconds,
becoming SW 1 foot at 5 seconds and S 1 foot at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: S 1 foot at 6 seconds,
becoming SW 2 ft at 4 seconds and S 1 foot at 7 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
2 to 4 ft. Wave Detail: SW 4 ft at 5 seconds and SE 1 foot at
8 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to
5 ft. Wave Detail: SW 5 ft at 6 seconds.
.SAT NIGHT...SW winds 20 to 25 kt, becoming W 15 to 20 kt after
midnight. Seas 3 to 5 ft. Wave Detail: SW 5 ft at 8 seconds and
SW 3 ft at 4 seconds.
.SUN AND SUN NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: SW 3 ft at 8 seconds and W 2 ft at
4 seconds.
.MON...S winds 5 to 10 kt. Seas 1 foot or less.
.MON NIGHT AND TUE...S winds 10 to 15 kt. Gusts up to 20 kt. Seas
around 2 ft. A chance of showers.
.TUE NIGHT...W winds 10 to 15 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.

$$

ANZ235-180900-
Rhode Island Sound-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 10 to 15 kt with gusts up to 20 kt,
diminishing to 5 to 10 kt after midnight. Seas 2 to 3 ft. Wave
Detail: SW 3 ft at 5 seconds and S 2 ft at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: SW 1 foot at 5 seconds and S
1 foot at 8 seconds, becoming SW 2 ft at 4 seconds and S 1 foot
at 8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt, increasing to 20 to 25 kt
after midnight. Seas 3 to 5 ft. Wave Detail: S 5 ft at 7 seconds.
.SAT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to
7 ft. Wave Detail: SW 7 ft at 6 seconds.
.SAT NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt,
becoming W 15 to 20 kt after midnight. Seas 5 to 7 ft. Wave
Detail: S 7 ft at 8 seconds and SW 1 foot at 4 seconds.
.SUN...W winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to
5 ft. Wave Detail: S 5 ft at 8 seconds and W 1 foot at 3 seconds.
.SUN NIGHT...NW winds 10 to 15 kt. Seas 2 to 4 ft.
.MON...SE winds around 10 kt. Seas around 2 ft.
.MON NIGHT THROUGH TUE NIGHT...W winds 10 to 15 kt with gusts up
to 20 kt. Seas 2 to 4 ft. A chance of showers.

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.

$$

ANZ237-180900-
Block Island Sound-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt with gusts up to 20 kt, becoming NW
after midnight. Seas 2 to 3 ft. Wave Detail: W 2 ft at 4 seconds
and S 2 ft at 8 seconds.
.FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 1 foot or less, then around
2 ft in the afternoon. Wave Detail: SW 1 foot at 5 seconds and S
1 foot at 8 seconds, becoming S 2 ft at 4 seconds and S 1 foot at
8 seconds.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
3 to 5 ft. Wave Detail: S 4 ft at 8 seconds and S 3 ft at
5 seconds.
.SAT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 4 to
6 ft. Wave Detail: SW 5 ft at 6 seconds.
.SAT NIGHT...SW winds 15 to 20 kt, becoming W 10 to 15 kt after
midnight. Gusts up to 25 kt. Seas 4 to 6 ft. Wave Detail: S 5 ft
at 8 seconds and W 2 ft at 4 seconds.
.SUN...NW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to
5 ft. Wave Detail: S 4 ft at 8 seconds and W 2 ft at 3 seconds.
.SUN NIGHT...NW winds 5 to 10 kt. Seas 2 to 3 ft.
.MON...SE winds 5 to 10 kt. Seas around 2 ft.
.MON NIGHT AND TUE...S winds 10 to 15 kt. Seas 2 to 3 ft. A
chance of showers.
.TUE NIGHT...W winds 10 to 15 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.

$$

ANZ230-180900-
Boston Harbor-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt. Waves around 2 ft this evening,
then 1 foot or less.
.FRI...SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up
to 20 kt in the afternoon. Waves 1 foot or less, then around 2 ft
in the afternoon.
.FRI NIGHT...SW winds around 15 kt with gusts up to 25 kt. Waves
around 2 ft. A chance of rain after midnight.
.SAT...SW winds 15 to 20 kt with gusts up to 25 kt. Waves around
2 ft. A chance of rain in the morning.
.SAT NIGHT THROUGH SUN NIGHT...NW winds 15 to 20 kt with gusts up
to 25 kt. Waves around 2 ft.
.MON...E winds 5 to 10 kt. Waves 1 foot or less.
.MON NIGHT AND TUE...S winds 10 to 15 kt. Waves 1 foot or less,
then around 2 ft. A chance of showers.
.TUE NIGHT...W winds 10 to 15 kt. Waves 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.

$$

ANZ236-180900-
Narragansett Bay-
402 PM EDT Thu Apr 17 2025

.TONIGHT...W winds 5 to 10 kt, diminishing to around 5 kt after
midnight. Waves around 2 ft.
.FRI...SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up
to 20 kt in the afternoon. Waves 1 foot or less, then around 2 ft
in the afternoon.
.FRI NIGHT...SW winds around 15 kt with gusts up to 25 kt. Waves
2 to 3 ft, building to 3 to 5 ft after midnight.
.SAT...SW winds 15 to 20 kt with gusts up to 25 kt. Waves 4 to
6 ft.
.SAT NIGHT...W winds 10 to 15 kt with gusts up to 25 kt. Waves
3 to 5 ft.
.SUN AND SUN NIGHT...N winds 10 to 15 kt with gusts up to 20 kt.
Waves 2 to 3 ft.
.MON...S winds 5 to 10 kt. Waves around 2 ft.
.MON NIGHT AND TUE...S winds 10 to 15 kt. Gusts up to 20 kt.
Waves 2 to 3 ft. A chance of showers.
.TUE NIGHT...W winds 5 to 10 kt. Waves 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.

$$

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