Coastal Waters Forecast
Issued by NWS Boston, MA

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
181
FZUS51 KBOX 222305
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
705 PM EDT Fri Aug 22 2025

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

ANZ200-231200-
705 PM EDT Fri Aug 22 2025

.Synopsis for Massachusetts and Rhode Island coastal waters...
Gusty NE winds will diminish during the day today, though seas will
remain elevated. Gale Warnings in effect through Friday evening.
High surf and dangerous rip currents remain a threat through
Saturday. Seas will gradually trend downward today through Saturday.

$$

ANZ250-231200-
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY EVENING...

.TONIGHT...S winds 5 to 10 kt. Seas 7 to 10 ft. Wave Detail: SE
8 ft at 14 seconds and E 7 ft at 10 seconds.
.SAT...S winds around 10 kt, increasing to 15 to 20 kt with gusts
up to 25 kt in the afternoon. Seas 5 to 8 ft. Wave Detail: E 8 ft
at 12 seconds and S 3 ft at 7 seconds.
.SAT NIGHT...S winds 15 to 20 kt with gusts up to 30 kt. Seas
5 to 7 ft. Wave Detail: E 6 ft at 11 seconds and S 4 ft at
5 seconds.
.SUN...S winds 10 to 15 kt, increasing to 15 to 20 kt in the
afternoon. Gusts up to 25 kt. Seas 4 to 5 ft. Wave Detail: E 5 ft
at 12 seconds and S 4 ft at 5 seconds.
.SUN NIGHT...S winds 15 to 20 kt, diminishing to 10 to 15 kt
after midnight. Gusts up to 25 kt. Seas 3 to 5 ft. Wave Detail: S
4 ft at 5 seconds and E 3 ft at 11 seconds. A chance of showers
after midnight.
.MON AND MON NIGHT...W 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 S 3 ft at
5 seconds. A chance of showers.
.TUE THROUGH WED...W winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 5 ft.
.WED NIGHT...SW winds around 10 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.

$$

ANZ251-231200-
Massachusetts Bay and Ipswich Bay-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY MORNING...

.TONIGHT...S winds 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: E
6 ft at 11 seconds.
.SAT...S winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 25 kt in the afternoon. Seas 4 to 6 ft. Wave Detail: E 6 ft
at 12 seconds and S 2 ft at 5 seconds.
.SAT NIGHT...S winds 15 to 20 kt, diminishing to 10 to 15 kt
after midnight. Gusts up to 25 kt. Seas 4 to 6 ft. Wave Detail: E
6 ft at 11 seconds and S 4 ft at 5 seconds.
.SUN...S winds 10 to 15 kt, increasing to 15 to 20 kt in the
afternoon. Gusts up to 25 kt. Seas 3 to 4 ft. Wave Detail: S 4 ft
at 5 seconds and E 4 ft at 12 seconds.
.SUN NIGHT...S winds 15 to 20 kt, diminishing to 10 to 15 kt
after midnight. Gusts up to 25 kt. Seas 2 to 4 ft. Wave Detail: S
4 ft at 5 seconds and E 3 ft at 11 seconds. A chance of showers
after midnight.
.MON AND MON NIGHT...W winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: E 3 ft at 7 seconds and S 2 ft at
4 seconds. A chance of showers.
.TUE THROUGH WED NIGHT...SW winds 10 to 15 kt with gusts up 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.

$$

ANZ231-231200-
Cape Cod Bay-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 1 AM EDT SATURDAY...

.TONIGHT...S winds 5 to 10 kt. Seas 3 to 5 ft. Wave Detail: E
5 ft at 14 seconds and N 4 ft at 6 seconds.
.SAT...S winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
up to 20 kt in the afternoon. Seas 2 to 4 ft. Wave Detail: E 4 ft
at 12 seconds and S 2 ft at 6 seconds.
.SAT NIGHT...S winds 10 to 15 kt with gusts up to 25 kt. Seas
2 to 4 ft. Wave Detail: E 4 ft at 12 seconds and S 2 ft at
4 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
3 ft. Wave Detail: E 3 ft at 11 seconds and S 2 ft at 3 seconds.
.SUN NIGHT AND MON...SE 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 E 2 ft at
10 seconds. A chance of showers.
.MON NIGHT...SW winds around 10 kt, becoming W after midnight.
Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds and E 2 ft at
8 seconds.
.TUE THROUGH WED NIGHT...SW winds 5 to 10 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.

$$

ANZ254-231200-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY EVENING...

.TONIGHT...N winds 10 to 15 kt with gusts up to 20 kt, becoming W
5 to 10 kt after midnight. Seas 8 to 11 ft. Wave Detail: E 10 ft
at 12 seconds.
.SAT...SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up
to 20 kt in the afternoon. Seas 6 to 9 ft. Wave Detail: E 9 ft at
12 seconds and SW 1 foot at 3 seconds.
.SAT NIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Seas
4 to 6 ft. Wave Detail: E 6 ft at 12 seconds and S 2 ft at
9 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 4 to
5 ft. Wave Detail: E 5 ft at 11 seconds and S 2 ft at 8 seconds.
.SUN NIGHT AND MON...SE winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 4 ft. Wave Detail: SE 4 ft at 6 seconds and E 4 ft at
13 seconds. A chance of showers. Vsby 1 to 3 NM.
.MON NIGHT...W winds around 10 kt. Seas 3 to 5 ft. Wave Detail:
SE 5 ft at 8 seconds and E 2 ft at 8 seconds.
.TUE THROUGH WED...W winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 5 ft.
.WED NIGHT...SW winds around 10 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.

$$

ANZ255-231200-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY EVENING...

.TONIGHT...NE winds 10 to 15 kt with gusts up to 20 kt, becoming
SW 5 to 10 kt after midnight. Seas 6 to 9 ft, subsiding to 5 to
7 ft after midnight. Wave Detail: SE 8 ft at 12 seconds and NE
6 ft at 9 seconds, becoming E 7 ft at 12 seconds and S 2 ft at
10 seconds.
.SAT...SW winds 5 to 10 kt, becoming S 10 to 15 kt in the
afternoon. Seas 5 to 7 ft. Wave Detail: E 7 ft at 12 seconds and
SW 2 ft at 3 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Seas 4 to 6 ft. Wave Detail: E
6 ft at 12 seconds and SW 2 ft at 4 seconds.
.SUN...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 3 to 5 ft. Wave Detail: E 4 ft at 12 seconds and S 3 ft at
8 seconds.
.SUN NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 3 to 5 ft. Wave Detail: S 3 ft at 5 seconds and E
3 ft at 11 seconds. A chance of showers after midnight.
.MON...SE winds 10 to 15 kt. Seas 3 to 4 ft. Wave Detail: SE 4 ft
at 7 seconds and E 2 ft at 10 seconds. A chance of showers. Vsby
1 to 3 NM in the morning.
.MON NIGHT...W winds 10 to 15 kt. Seas 3 to 5 ft.
.TUE THROUGH WED...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 5 ft.
.WED NIGHT...W winds 10 to 15 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.

$$

ANZ256-231200-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SUNDAY EVENING...

.TONIGHT...S winds 5 to 10 kt, becoming SW after midnight. Seas
5 to 8 ft. Wave Detail: SE 8 ft at 12 seconds and N 2 ft at
5 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 4 to 6 ft. Wave Detail: E 6 ft at 12 seconds and SW 2 ft at
3 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Seas 4 to 6 ft. Wave Detail: E
5 ft at 12 seconds and SW 3 ft at 4 seconds.
.SUN...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 4 to 5 ft. Wave Detail: E 4 ft at 12 seconds and S 3 ft at
7 seconds.
.SUN NIGHT AND MON...S winds 10 to 15 kt with gusts up to 20 kt.
Seas 3 to 4 ft. Wave Detail: SE 4 ft at 6 seconds and E 4 ft at
13 seconds. A chance of showers.
.MON NIGHT...SW winds 10 to 15 kt, becoming NW after midnight.
Seas 3 to 5 ft. Wave Detail: S 5 ft at 8 seconds and E 3 ft at
8 seconds.
.TUE THROUGH WED...NW winds 10 to 15 kt with gusts up to 20 kt.
Seas 4 to 5 ft.
.WED NIGHT...W winds 10 to 15 kt with gusts up 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.

$$

ANZ232-231200-
Nantucket Sound-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH SATURDAY EVENING...

.TONIGHT...E winds 10 to 15 kt, becoming SW 5 to 10 kt after
midnight. Seas 3 to 5 ft. Wave Detail: NE 4 ft at 8 seconds and E
4 ft at 12 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 3 to 5 ft. Wave Detail: E 4 ft at 12 seconds and SW 2 ft at
3 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 2 to 4 ft. Wave Detail: E 3 ft at 12 seconds and S
2 ft at 5 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: E 3 ft at 13 seconds and S 2 ft at 4 seconds.
.SUN NIGHT AND MON...SE 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
10 seconds. A chance of showers.
.MON NIGHT...W winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: SW
2 ft at 3 seconds and S 2 ft at 7 seconds.
.TUE THROUGH WED NIGHT...W 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.

$$

ANZ233-231200-
Vineyard Sound-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 AM EDT SATURDAY...

.TONIGHT...SE winds 5 to 10 kt, becoming SW after midnight. Seas
2 to 4 ft. Wave Detail: SE 3 ft at 13 seconds and N 2 ft at
5 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at
12 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and S
2 ft at 7 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: SW 2 ft at 5 seconds and E 2 ft at 13 seconds.
.SUN NIGHT AND MON...S winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 1 foot at
10 seconds. A chance of showers.
.MON NIGHT...SW winds around 10 kt, becoming NW after midnight.
Seas 2 to 3 ft. Wave Detail: S 2 ft at 7 seconds and E 2 ft at
8 seconds.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up 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.

$$

ANZ234-231200-
Buzzards Bay-
705 PM EDT Fri Aug 22 2025

.TONIGHT...SE winds 5 to 10 kt, becoming SW after midnight. Seas
2 to 3 ft. Wave Detail: SE 3 ft at 13 seconds and N 2 ft at
5 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 2 to 3 ft. Wave Detail: E 3 ft at 12 seconds and SW 2 ft at
4 seconds.
.SAT NIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Seas
2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and S 2 ft at
7 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
3 ft. Wave Detail: S 2 ft at 5 seconds and E 2 ft at 13 seconds.
.SUN NIGHT AND MON...S 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 1 foot at
10 seconds. A chance of showers.
.MON NIGHT...SW winds 10 to 15 kt, becoming NW after midnight.
Seas around 2 ft. Wave Detail: S 2 ft at 7 seconds and E 2 ft at
8 seconds.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up to
25 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.

$$

ANZ235-231200-
Rhode Island Sound-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 AM EDT SATURDAY...

.TONIGHT...S winds 5 to 10 kt, becoming SW after midnight. Seas
4 to 6 ft. Wave Detail: SE 6 ft at 12 seconds and NE 2 ft at
5 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 2 to 4 ft. Wave Detail: SE 4 ft at 12 seconds and SW 2 ft at
3 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 2 to 4 ft. Wave Detail: SW 3 ft at 4 seconds and S
3 ft at 9 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: SW 3 ft at 5 seconds and E 2 ft at 14 seconds.
.SUN NIGHT AND MON...S 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 1 foot at
9 seconds. A chance of showers.
.MON NIGHT...SW winds 10 to 15 kt, becoming NW after midnight.
Seas 2 to 4 ft. Wave Detail: S 4 ft at 7 seconds and SE 3 ft at
8 seconds.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up 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.

$$

ANZ237-231200-
Block Island Sound-
705 PM EDT Fri Aug 22 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 AM EDT SATURDAY...

.TONIGHT...S winds 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: SE
6 ft at 12 seconds and E 2 ft at 8 seconds.
.SAT...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 3 to 5 ft. Wave Detail: SE 5 ft at 12 seconds and SW 2 ft at
3 seconds.
.SAT NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Seas 3 to 4 ft. Wave Detail: E 3 ft at 13 seconds and SW
2 ft at 4 seconds.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to
4 ft. Wave Detail: E 3 ft at 13 seconds and SW 2 ft at 5 seconds.
.SUN NIGHT AND MON...S 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
14 seconds. A chance of showers.
.MON NIGHT...SW winds around 10 kt, becoming NW after midnight.
Seas 2 to 4 ft. Wave Detail: S 4 ft at 7 seconds and E 2 ft at
8 seconds.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up 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.

$$

ANZ230-231200-
Boston Harbor-
705 PM EDT Fri Aug 22 2025

.TONIGHT...S winds 5 to 10 kt. Waves 1 foot or less, except 2 to
4 ft at the outer harbor entrance.
.SAT...S winds 5 to 10 kt, increasing to 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. At the outer harbor entrance, waves 2 to
4 ft.
.SAT NIGHT...S winds 15 to 20 kt, diminishing to 10 to 15 kt
after midnight. Waves around 2 ft.
.SUN...S winds 10 to 15 kt, increasing to 15 to 20 kt in the
afternoon. Gusts up to 25 kt. Waves around 2 ft.
.SUN NIGHT...S winds 10 to 15 kt. Gusts up to 25 kt in the
evening. Waves around 2 ft in the evening, then 1 foot or less. A
chance of showers after midnight.
.MON...SE winds around 10 kt. Waves around 2 ft. Showers likely,
mainly in the morning.
.MON NIGHT...SW winds around 10 kt, becoming W after midnight.
Waves around 2 ft in the evening, then 1 foot or less. A chance
of showers in the evening.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up to
20 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.

$$

ANZ236-231200-
Narragansett Bay-
705 PM EDT Fri Aug 22 2025

.TONIGHT...S winds 5 to 10 kt. Waves 2 to 4 ft.
.SAT...SW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up
to 20 kt in the afternoon. Waves 2 to 3 ft.
.SAT NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the
evening. Waves around 2 ft.
.SUN...S winds 10 to 15 kt with gusts up to 20 kt. Waves 2 to
3 ft.
.SUN NIGHT AND MON...S winds 10 to 15 kt with gusts up to 20 kt.
Waves around 2 ft. A chance of showers.
.MON NIGHT...SW winds 5 to 10 kt, becoming NW after midnight.
Waves 2 to 3 ft. A chance of showers in the evening.
.TUE THROUGH WED NIGHT...W winds 10 to 15 kt with gusts up to
20 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.

$$

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/NWSBoston

You can follow us on Twitter at
@NWSBoston