256
FZUS51 KBOX 040806
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
405 AM EDT Mon Aug 4 2025

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

ANZ200-042100-
405 AM EDT Mon Aug 4 2025

.Synopsis for Massachusetts and Rhode Island coastal waters...
A prolonged period of rather tranquil marine conditions due to a
vast high pres most of this week, but will need to monitor a low
pres off the Carolina coast. This feature may send swells towards
srn New England from Wednesday through early Friday.

$$

ANZ250-042100-
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt, becoming S this afternoon. Seas
2 to 3 ft. Wave Detail: SE 2 ft at 8 seconds and SW 1 foot at
3 seconds.
.TONIGHT...S winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E
2 ft at 8 seconds and SW 1 foot at 3 seconds.
.TUE...NE winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: NE 2 ft
at 3 seconds and E 2 ft at 8 seconds.
.TUE NIGHT...NE winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E
3 ft at 8 seconds and NE 2 ft at 4 seconds.
.WED AND WED NIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave
Detail: E 3 ft at 8 seconds and NE 1 foot at 4 seconds.
.THU THROUGH FRI NIGHT...S winds 5 to 10 kt with gusts up to
20 kt. Seas 3 to 4 ft. Wave Detail: E 4 ft at 8 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.

$$

ANZ251-042100-
Massachusetts Bay and Ipswich Bay-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt, becoming SE this afternoon. Seas
around 2 ft. Wave Detail: E 2 ft at 7 seconds and SW 1 foot at
3 seconds.
.TONIGHT...S winds 5 to 10 kt, becoming E after midnight. Seas
around 2 ft. Wave Detail: E 2 ft at 8 seconds and SE 1 foot at
3 seconds.
.TUE...NE winds 5 to 10 kt, increasing to 10 to 15 kt in the
afternoon. Seas around 2 ft. Wave Detail: NE 2 ft at 3 seconds
and E 2 ft at 7 seconds.
.TUE NIGHT...NE winds 5 to 10 kt. Seas around 2 ft. Wave Detail:
NE 2 ft at 4 seconds and E 2 ft at 8 seconds.
.WED AND WED NIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave
Detail: E 3 ft at 8 seconds and NE 1 foot at 4 seconds.
.THU THROUGH FRI NIGHT...S winds 10 to 15 kt with gusts up to
20 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and SE
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.

$$

ANZ231-042100-
Cape Cod Bay-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds around 5 kt, becoming S this afternoon. Seas
1 foot or less. Wave Detail: SW 1 foot at 2 seconds and SE 1 foot
at 7 seconds. Patchy smoke this afternoon.
.TONIGHT...S winds 5 to 10 kt. Seas around 2 ft in the evening,
then 1 foot or less. Wave Detail: E 2 ft at 7 seconds and SW
1 foot at 2 seconds, becoming SW 1 foot at 2 seconds and E 1 foot
at 7 seconds.
.TUE...E winds 5 to 10 kt, becoming NE in the afternoon. Seas
around 2 ft. Wave Detail: E 2 ft at 7 seconds and S 1 foot at
2 seconds.
.TUE NIGHT...NE winds 5 to 10 kt. Seas around 2 ft. Wave Detail:
E 2 ft at 7 seconds and N 1 foot at 4 seconds.
.WED AND WED NIGHT...E winds 5 to 10 kt. Seas around 2 ft. Wave
Detail: E 2 ft at 8 seconds and N 1 foot at 4 seconds.
.THU THROUGH FRI NIGHT...S winds 5 to 10 kt. Seas around 2 ft.
Wave Detail: E 2 ft at 8 seconds and E 1 foot at 2 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.

$$

ANZ254-042100-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
405 AM EDT Mon Aug 4 2025

.TODAY...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft
at 8 seconds.
.TONIGHT...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E
3 ft at 8 seconds.
.TUE...E winds 5 to 10 kt, becoming NE in the afternoon. Seas
2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and NE 1 foot at
2 seconds.
.TUE NIGHT...NE winds around 10 kt. Seas 2 to 3 ft. Wave Detail:
E 3 ft at 8 seconds and NE 1 foot at 3 seconds.
.WED AND WED NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 4 ft. Wave Detail: E 4 ft at 8 seconds and NE 2 ft at
4 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt with gusts up to
20 kt. Seas 3 to 4 ft. Wave Detail: E 4 ft at 8 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.

$$

ANZ255-042100-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
405 AM EDT Mon Aug 4 2025

.TODAY...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft
at 7 seconds.
.TONIGHT...S winds 5 to 10 kt, becoming SE after midnight. Seas
2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and S 1 foot at
10 seconds.
.TUE...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at
7 seconds and S 2 ft at 8 seconds.
.TUE NIGHT...NE winds 10 to 15 kt. Seas 2 to 4 ft. Wave Detail: E
4 ft at 8 seconds and NE 1 foot at 3 seconds.
.WED AND WED NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 4 ft. Wave Detail: E 4 ft at 8 seconds and NE 1 foot at
3 seconds.
.THU THROUGH FRI NIGHT...E winds 10 to 15 kt with gusts up to
20 kt. Seas 3 to 5 ft. Wave Detail: E 5 ft at 8 seconds and NE
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.

$$

ANZ256-042100-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE
3 ft at 8 seconds.
.TONIGHT...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE
3 ft at 8 seconds and S 1 foot at 9 seconds.
.TUE...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at
7 seconds and S 2 ft at 9 seconds.
.TUE NIGHT...NE winds 10 to 15 kt. Seas 3 to 4 ft. Wave Detail: E
4 ft at 8 seconds and E 1 foot at 3 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 4 ft. Wave Detail: E 4 ft at 8 seconds and NE 1 foot at
3 seconds.
.THU THROUGH FRI NIGHT...E winds 10 to 15 kt with gusts up to
20 kt. Seas 4 to 5 ft. Wave Detail: E 5 ft at 8 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.

$$

ANZ232-042100-
Nantucket Sound-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: S
1 foot at 2 seconds and SW 1 foot at 2 seconds.
.TONIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SW
1 foot at 2 seconds and E 1 foot at 7 seconds.
.TUE...E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E
1 foot at 2 seconds and S 1 foot at 2 seconds.
.TUE NIGHT...NE winds 10 to 15 kt. Seas around 2 ft. Wave Detail:
NE 2 ft at 3 seconds and E 2 ft at 7 seconds.
.WED AND WED NIGHT...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 E 2 ft at
8 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt. Seas 2 to 3 ft.
Wave Detail: E 3 ft at 8 seconds and E 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.

$$

ANZ233-042100-
Vineyard Sound-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas 1 foot or less, then around
2 ft this afternoon. Wave Detail: SW 1 foot at 2 seconds and SE
1 foot at 7 seconds, becoming SW 1 foot at 2 seconds and E 1 foot
at 8 seconds.
.TONIGHT...S winds 5 to 10 kt. Seas around 2 ft. Wave Detail: S
1 foot at 2 seconds and SE 1 foot at 8 seconds.
.TUE...E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E 2 ft
at 7 seconds and SW 1 foot at 2 seconds.
.TUE NIGHT...NE winds around 10 kt. Seas around 2 ft. Wave
Detail: E 2 ft at 7 seconds and NE 1 foot at 3 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and NE 1 foot
at 3 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt. Seas around 2 ft.
Wave Detail: E 2 ft at 8 seconds and NE 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.

$$

ANZ234-042100-
Buzzards Bay-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas 1 foot or less. Wave Detail:
SW 1 foot at 3 seconds and SE 1 foot at 7 seconds.
.TONIGHT...S winds 5 to 10 kt. Seas 1 foot or less. Wave Detail:
SW 1 foot at 2 seconds and E 1 foot at 8 seconds.
.TUE...E winds 5 to 10 kt. Seas 1 foot or less, then around 2 ft
in the afternoon. Wave Detail: E 1 foot at 2 seconds and S 1 foot
at 2 seconds, becoming E 2 ft at 7 seconds and E 1 foot at
2 seconds.
.TUE NIGHT...NE winds around 10 kt. Seas around 2 ft. Wave
Detail: E 2 ft at 7 seconds and NE 1 foot at 3 seconds.
.WED AND WED NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt.
Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and NE 1 foot
at 3 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt with gusts up to
20 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and NE
1 foot at 2 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.

$$

ANZ235-042100-
Rhode Island Sound-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE
2 ft at 8 seconds and SW 1 foot at 2 seconds.
.TONIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE
2 ft at 9 seconds and SW 1 foot at 2 seconds.
.TUE...E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft
at 7 seconds and S 2 ft at 9 seconds.
.TUE NIGHT...NE winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail:
SE 3 ft at 8 seconds and E 2 ft at 4 seconds.
.WED AND WED NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: SE 3 ft at 9 seconds and NE 2 ft at
3 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt. Seas 2 to 3 ft.
Wave Detail: E 3 ft at 8 seconds and E 1 foot at 4 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.

$$

ANZ237-042100-
Block Island Sound-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE
2 ft at 8 seconds and SW 1 foot at 2 seconds.
.TONIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE
2 ft at 8 seconds and SW 1 foot at 2 seconds.
.TUE...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at
7 seconds and SE 2 ft at 8 seconds.
.TUE NIGHT...E winds around 10 kt. Seas 2 to 3 ft. Wave Detail:
SE 3 ft at 8 seconds and E 1 foot at 3 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and NE 1 foot at
3 seconds.
.THU THROUGH FRI NIGHT...SE winds 10 to 15 kt with gusts up to
20 kt. Seas 2 to 4 ft. Wave Detail: E 4 ft at 8 seconds and NE
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.

$$

ANZ230-042100-
Boston Harbor-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds around 5 kt, becoming SE this afternoon. Waves
1 foot or less. Patchy smoke this afternoon.
.TONIGHT...SE winds 5 to 10 kt. Waves 1 foot or less. Patchy
smoke in the evening.
.TUE...NE winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Waves around 2 ft.
.TUE NIGHT...NE winds 5 to 10 kt. Waves around 2 ft in the
evening, then 1 foot or less.
.WED AND WED NIGHT...E winds 5 to 10 kt. Waves around 2 ft.
.THU THROUGH FRI NIGHT...S 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.

$$

ANZ236-042100-
Narragansett Bay-
405 AM EDT Mon Aug 4 2025

.TODAY...SW winds 5 to 10 kt. Waves 1 foot or less.
.TONIGHT...SW winds 5 to 10 kt. Waves around 2 ft.
.TUE...NE winds 5 to 10 kt, becoming E in the afternoon. Waves
around 2 ft.
.TUE NIGHT...NE winds 5 to 10 kt. Waves around 2 ft.
.WED AND WED NIGHT...NE winds 10 to 15 kt with gusts up to 20 kt.
Waves around 2 ft.
.THU THROUGH FRI NIGHT...SE winds 5 to 10 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.

$$

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