FZUS51 KBOX 290805
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
405 AM EDT Fri Aug 29 2025

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

ANZ200-292100
405 AM EDT Fri Aug 29 2025

Synopsis for Massachusetts and Rhode Island coastal waters

High pressure provides tranquil weather for the MA and RI waters through Friday morning. A cold front approaches Southern New England Friday evening and will be accompanied by scattered showers and thunderstorms. The front exits offshore late Friday night, followed by high pressure building back into the region for the holiday weekend and possibly lingering into much of next week. This will provide an extended period of tranquil boating conditions.

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ANZ250-292100
Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt, becoming SE 15 to 20 kt this afternoon. Gusts up to 25 kt. Seas 2 to 3 ft. Wave Detail: S 3 ft at 5 seconds. A chance of showers with isolated tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 10 to 15 kt with gusts up to 20 kt, becoming W after midnight. Seas 2 to 3 ft. Wave Detail: S 3 ft at 5 seconds. Showers likely, mainly in the evening. Patchy fog in the evening with vsby 1 to 3 NM.

SAT
NW winds 10 to 15 kt, becoming SW 5 to 10 kt in the afternoon. Seas around 2 ft. Wave Detail: NW 2 ft at 3 seconds and SE 2 ft at 6 seconds.

SAT NIGHT
SW winds around 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and SW 1 foot at 3 seconds.

SUN
NW winds 5 to 10 kt, becoming NE in the afternoon. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and N 1 foot at 3 seconds.

SUN NIGHT
S winds around 5 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and N 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
S winds 5 to 10 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.

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ANZ251-292100
Massachusetts Bay and Ipswich Bay
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt, becoming SE 15 to 20 kt this afternoon. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 4 seconds. A slight chance of showers this morning, then a chance of showers with isolated tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 5 seconds. Patchy fog in the evening. Showers in the evening with vsby 1 to 3 NM.

SAT
NW winds around 10 kt, becoming SW in the afternoon. Seas around 2 ft. Wave Detail: NW 1 foot at 3 seconds and E 1 foot at 4 seconds.

SAT NIGHT
SW winds around 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SW 1 foot at 2 seconds and E 1 foot at 3 seconds.

SUN
NW winds 5 to 10 kt, becoming E in the afternoon. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and N 1 foot at 3 seconds.

SUN NIGHT
S winds 5 to 10 kt, becoming W after midnight. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and NW 1 foot at 2 seconds.

MON THROUGH TUE NIGHT
S winds 5 to 10 kt. Seas around 2 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.

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ANZ231-292100
Cape Cod Bay
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Gusts up to 20 kt this afternoon. Seas 2 to 3 ft. Wave Detail: SE 2 ft at 5 seconds and S 1 foot at 2 seconds. A slight chance of showers with isolated tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming W after midnight. Seas around 2 ft in the evening, then 1 foot or less. Wave Detail: SE 2 ft at 6 seconds and S 1 foot at 3 seconds, becoming W 1 foot at 2 seconds and SE 1 foot at 4 seconds. Showers likely, mainly in the evening. Patchy fog in the evening.

SAT
NW winds 5 to 10 kt. Seas around 2 ft in the morning, then 1 foot or less. Wave Detail: NW 1 foot at 3 seconds and E 1 foot at 3 seconds, becoming NW 1 foot at 3 seconds and SE 1 foot at 7 seconds.

SAT NIGHT
SW winds 5 to 10 kt, becoming NW after midnight. Seas 1 foot or less. Wave Detail: SW 1 foot at 3 seconds and NE 1 foot at 3 seconds.

SUN
NW winds 5 to 10 kt, becoming NE in the afternoon. Seas 1 foot or less. Wave Detail: N 1 foot at 3 seconds and SE 1 foot at 8 seconds.

SUN NIGHT
SE winds around 5 kt, becoming NW after midnight. Seas 1 foot or less. Wave Detail: N 1 foot at 3 seconds and E 1 foot at 8 seconds.

MON THROUGH TUE NIGHT
SE winds 5 to 10 kt. Seas 1 foot or less.

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.

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ANZ254-292100
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA out 20 nm
405 AM EDT Fri Aug 29 2025

TODAY
SE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 7 seconds and SW 2 ft at 4 seconds. A slight chance of showers this afternoon.

TONIGHT
SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: S 2 ft at 6 seconds. A chance of showers after midnight with vsby 1 to 3 NM.

SAT
W winds around 10 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at 6 seconds and W 1 foot at 3 seconds.

SAT NIGHT
SW winds around 10 kt, becoming NW after midnight. Seas 2 to 3 ft. Wave Detail: SE 2 ft at 7 seconds and W 1 foot at 3 seconds.

SUN AND SUN NIGHT
N winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and N 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and N 1 foot at 3 seconds.

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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ANZ255-292100
Coastal Waters extending out to 25 nm South of Marthas Vineyard and Nantucket
405 AM EDT Fri Aug 29 2025

TODAY
SE winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 3 ft at 6 seconds. A slight chance of showers this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming W after midnight. Seas around 2 ft. Wave Detail: S 2 ft at 6 seconds. A chance of showers. Vsby 1 to 3 NM in the evening.

SAT
W winds around 10 kt. Seas 2 to 3 ft. Wave Detail: W 2 ft at 4 seconds and S 2 ft at 6 seconds.

SAT NIGHT
W winds around 10 kt. Seas 2 to 3 ft. Wave Detail: W 2 ft at 5 seconds and SE 2 ft at 6 seconds.

SUN AND SUN NIGHT
NE winds 5 to 10 kt. Seas around 2 ft. Wave Detail: NW 2 ft at 3 seconds and SE 2 ft at 7 seconds.

MON THROUGH TUE NIGHT
E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 8 seconds and NE 2 ft at 3 seconds.

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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ANZ256-292100
Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 nm South of Block Island
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Seas around 3 ft. Wave Detail: S 3 ft at 6 seconds. A slight chance of showers. A chance of tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
W winds around 10 kt, becoming NW after midnight. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 5 seconds and SE 2 ft at 7 seconds. A chance of showers. Vsby 1 to 3 NM in the evening.

SAT
W winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: NW 2 ft at 4 seconds and SE 2 ft at 7 seconds.

SAT NIGHT
W winds 10 to 15 kt, becoming NW after midnight. Seas 2 to 3 ft. Wave Detail: W 2 ft at 4 seconds and SE 2 ft at 6 seconds.

SUN
N winds around 10 kt, becoming W in the afternoon. Seas around 2 ft. Wave Detail: N 2 ft at 3 seconds and SE 2 ft at 8 seconds.

SUN NIGHT
SE winds around 5 kt, becoming NE after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and SW 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
E winds 5 to 10 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.

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ANZ232-292100
Nantucket Sound
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Gusts up to 20 kt this morning. Seas 2 to 3 ft. Wave Detail: S 2 ft at 3 seconds and SE 2 ft at 7 seconds. A slight chance of showers this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming W after midnight. Seas around 2 ft. Wave Detail: SE 1 foot at 5 seconds. Showers likely, mainly in the evening. Patchy fog in the evening.

SAT
W winds 10 to 15 kt. Seas around 2 ft. Wave Detail: W 2 ft at 3 seconds and SE 1 foot at 6 seconds.

SAT NIGHT
W winds 10 to 15 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: W 2 ft at 3 seconds and SE 1 foot at 6 seconds.

SUN AND SUN NIGHT
N winds 5 to 10 kt. Seas around 2 ft. Wave Detail: N 1 foot at 3 seconds and SE 1 foot at 7 seconds.

MON THROUGH TUE NIGHT
E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: N 1 foot at 3 seconds and E 1 foot at 7 seconds.

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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ANZ233-292100
Vineyard Sound
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at 6 seconds and SE 1 foot at 3 seconds. A slight chance of showers. Isolated tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: S 2 ft at 6 seconds and E 1 foot at 3 seconds. Showers likely, mainly in the evening. Patchy fog in the evening.

SAT
NW winds around 10 kt, becoming W in the afternoon. Seas around 2 ft. Wave Detail: W 2 ft at 4 seconds and S 1 foot at 6 seconds.

SAT NIGHT
W winds 10 to 15 kt, becoming NW 5 to 10 kt after midnight. Seas around 2 ft. Wave Detail: S 2 ft at 5 seconds.

SUN
N winds 5 to 10 kt, becoming SW in the afternoon. Seas around 2 ft in the morning, then 1 foot or less. Wave Detail: NW 1 foot at 4 seconds and SE 1 foot at 7 seconds, becoming N 1 foot at 3 seconds and W 1 foot at 3 seconds.

SUN NIGHT
SE winds 5 to 10 kt, becoming NW after midnight. Seas 1 foot or less. Wave Detail: NE 1 foot at 2 seconds and SW 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
SE winds 5 to 10 kt. Seas around 2 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.

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ANZ234-292100
Buzzards Bay
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at 6 seconds. A slight chance of showers. Isolated tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft in the evening, then 1 foot or less. Wave Detail: SE 2 ft at 5 seconds, becoming W 1 foot at 5 seconds and SE 1 foot at 5 seconds. Showers likely, mainly in the evening. Patchy fog in the evening.

SAT
NW winds around 10 kt, becoming W in the afternoon. Seas 1 foot or less, then around 2 ft in the afternoon. Wave Detail: NW 1 foot at 3 seconds and SE 1 foot at 6 seconds, becoming S 1 foot at 5 seconds.

SAT NIGHT
W winds 10 to 15 kt, becoming NW 5 to 10 kt after midnight. Seas around 2 ft in the evening, then 1 foot or less. Wave Detail: S 2 ft at 5 seconds, becoming W 1 foot at 4 seconds and SE 1 foot at 7 seconds.

SUN
NW winds 5 to 10 kt, becoming S in the afternoon. Seas 1 foot or less. Wave Detail: N 1 foot at 3 seconds and SE 1 foot at 7 seconds.

SUN NIGHT
SE winds 5 to 10 kt, becoming NW after midnight. Seas 1 foot or less. Wave Detail: NE 1 foot at 2 seconds and SW 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
SE winds 5 to 10 kt. Seas around 2 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.

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ANZ235-292100
Rhode Island Sound
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 3 ft at 6 seconds. A slight chance of showers this morning, then a chance of showers and tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
W winds around 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: S 2 ft at 6 seconds. Showers likely with a chance of tstms in the evening, then a chance of showers after midnight. Patchy fog in the evening. Some tstms may produce gusty winds, small hail, and heavy rainfall in the evening with vsby 1 to 3 NM.

SAT
NW winds around 10 kt, becoming W in the afternoon. Seas around 2 ft. Wave Detail: NW 2 ft at 3 seconds and SE 2 ft at 6 seconds.

SAT NIGHT
W winds 10 to 15 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SW 2 ft at 4 seconds and SE 2 ft at 6 seconds.

SUN
N winds 5 to 10 kt, becoming SW in the afternoon. Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds and N 1 foot at 3 seconds.

SUN NIGHT
S winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and SW 1 foot at 3 seconds.

MON THROUGH TUE NIGHT
SE winds 5 to 10 kt. Seas around 2 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.

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ANZ237-292100
Block Island Sound
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and S 2 ft at 7 seconds. A slight chance of showers this morning, then a chance of showers and tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
NW winds 10 to 15 kt. Seas around 2 ft. Wave Detail: NW 2 ft at 3 seconds and SE 2 ft at 6 seconds. Showers likely with a chance of tstms in the evening. Some tstms may produce gusty winds, small hail, and heavy rainfall in the evening with vsby 1 to 3 NM.

SAT
NW winds around 10 kt, becoming W in the afternoon. Seas around 2 ft. Wave Detail: NW 2 ft at 3 seconds and SE 2 ft at 7 seconds.

SAT NIGHT
W winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: W 2 ft at 3 seconds and SE 2 ft at 6 seconds.

SUN
N winds 5 to 10 kt, becoming SW in the afternoon. Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds and NW 1 foot at 3 seconds.

SUN NIGHT
S winds 5 to 10 kt, becoming NW after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and SW 1 foot at 2 seconds.

MON THROUGH TUE NIGHT
SE winds 5 to 10 kt. Seas around 2 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.

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ANZ230-292100
Boston Harbor
405 AM EDT Fri Aug 29 2025

TODAY
S winds 5 to 10 kt, becoming SE 10 to 15 kt this afternoon. Waves around 2 ft. A chance of showers this morning, then showers with a chance of tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
SW winds 5 to 10 kt, becoming NW after midnight. Waves 1 foot or less. Showers in the evening.

SAT
W winds 5 to 10 kt. Waves 1 foot or less.

SAT NIGHT
W winds 5 to 10 kt. Waves 1 foot or less.

SUN
NW winds 5 to 10 kt, becoming E in the afternoon. Waves 1 foot or less.

SUN NIGHT
SE winds 5 to 10 kt, becoming W after midnight. Waves 1 foot or less.

MON THROUGH TUE NIGHT
S winds 5 to 10 kt. Waves 1 foot or less.

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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ANZ236-292100
Narragansett Bay
405 AM EDT Fri Aug 29 2025

TODAY
S winds 10 to 15 kt. Gusts up to 20 kt this afternoon. Waves around 2 ft. A slight chance of showers this morning, then a chance of showers and tstms this afternoon. Some tstms may produce gusty winds, small hail, and heavy rainfall this afternoon.

TONIGHT
W winds 5 to 10 kt, becoming NW after midnight. Waves around 2 ft. Patchy fog in the evening. Showers with a chance of tstms in the evening. Some tstms may produce gusty winds, small hail, and heavy rainfall in the evening with vsby 1 to 3 NM.

SAT
NW winds 5 to 10 kt. Waves 1 foot or less, then around 2 ft in the afternoon.

SAT NIGHT
NW winds 5 to 10 kt. Waves around 2 ft.

SUN
N winds 5 to 10 kt, becoming W in the afternoon. Waves 1 foot or less.

SUN NIGHT
S winds 5 to 10 kt, becoming NW after midnight. Waves 1 foot or less.

MON THROUGH TUE NIGHT
S winds 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.

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