856 FZUS51 KBOX 240506 CWFBOX Coastal Waters Forecast for Massachusetts and Rhode Island National Weather Service Boston/Norton MA 105 AM EDT Sun Aug 24 2025 Coastal waters from the Merrimack River MA to Watch Hill RI out to 25 NM ANZ200-241800- 105 AM EDT Sun Aug 24 2025 .Synopsis for Massachusetts and Rhode Island coastal waters... Seas will gradually trend downward tonight through Sunday. Breezy southwest winds shift south Sunday ahead of a cold front expected to pass over the waters Monday afternoon/evening. High pressure builds in from the west on Tuesday and remains in control through midweek. $$ ANZ250-241800- Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary- 105 AM EDT Sun Aug 24 2025 ...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING... .REST OF TONIGHT...S winds 10 to 15 kt with gusts up to 25 kt. Seas 4 to 6 ft. Wave Detail: E 5 ft at 11 seconds and SW 4 ft at 4 seconds. .SUN...S winds 10 to 15 kt, increasing to 15 to 20 kt in the afternoon. Gusts up to 25 kt. Seas 4 to 5 ft. Wave Detail: E 5 ft at 11 seconds and SW 4 ft at 4 seconds. .SUN NIGHT...S winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Gusts up to 25 kt. Seas 3 to 5 ft. Wave Detail: S 3 ft at 5 seconds and E 3 ft at 10 seconds. .MON...SE winds 5 to 10 kt. Seas 3 to 4 ft. Wave Detail: S 2 ft at 4 seconds and E 2 ft at 9 seconds. A chance of showers. .MON NIGHT AND TUE...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: SE 4 ft at 8 seconds and SE 3 ft at 8 seconds. .TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 4 ft. Wave Detail: SE 3 ft at 7 seconds and SE 3 ft at 8 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ251-241800- Massachusetts Bay and Ipswich Bay- 105 AM EDT Sun Aug 24 2025 ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 7 AM EDT THIS MORNING... .REST OF TONIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: E 5 ft at 11 seconds and S 3 ft at 4 seconds. .SUN...S winds 10 to 15 kt with gusts up to 25 kt. Seas 3 to 4 ft. Wave Detail: E 4 ft at 11 seconds and SE 3 ft at 4 seconds. .SUN NIGHT...S winds 10 to 15 kt. Gusts up to 25 kt in the evening. Seas 2 to 4 ft. Wave Detail: SE 3 ft at 5 seconds and E 3 ft at 10 seconds. A chance of showers after midnight. .MON...SE winds around 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 10 seconds and SE 2 ft at 5 seconds. A chance of showers. .MON NIGHT...SW winds around 10 kt, becoming W after midnight. Seas 2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and SE 2 ft at 8 seconds. A chance of showers in the evening. .TUE AND TUE NIGHT...W 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 SW 2 ft at 3 seconds. .WED THROUGH THU 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. $$ ANZ231-241800- Cape Cod Bay- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds around 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 11 seconds and SW 1 foot at 3 seconds. .SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 11 seconds and SW 2 ft at 3 seconds. .SUN NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 10 seconds. .MON...SE winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 9 seconds and E 2 ft at 10 seconds. A chance of showers. .MON NIGHT AND TUE...SW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and SE 2 ft at 8 seconds. .TUE NIGHT...W winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas around 2 ft. Wave Detail: E 2 ft at 7 seconds and S 2 ft at 7 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ254-241800- Coastal waters from Provincetown MA to Chatham MA to Nantucket MA out 20 nm- 105 AM EDT Sun Aug 24 2025 ...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING... .REST OF TONIGHT...S winds around 10 kt with gusts up to 20 kt. Seas 4 to 6 ft. Wave Detail: E 5 ft at 11 seconds and S 1 foot at 3 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 3 seconds. .SUN NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas 3 to 5 ft. Wave Detail: E 4 ft at 12 seconds and S 3 ft at 6 seconds. A chance of showers after midnight with vsby 1 to 3 NM. .MON...E winds around 10 kt, becoming W in the afternoon. Seas 3 to 4 ft, building to 4 to 6 ft in the afternoon. Wave Detail: SE 3 ft at 5 seconds and E 2 ft at 9 seconds, becoming SE 4 ft at 9 seconds and S 2 ft at 5 seconds. A chance of showers. Patchy fog in the morning with vsby 1 to 3 NM. .MON NIGHT...W winds around 10 kt. Seas 4 to 6 ft. Wave Detail: SE 5 ft at 8 seconds and E 2 ft at 8 seconds. .TUE AND TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: SE 5 ft at 8 seconds and SE 3 ft at 8 seconds. .WED THROUGH THU NIGHT...SW 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. $$ ANZ255-241800- Coastal Waters extending out to 25 nm South of Marthas Vineyard and Nantucket- 105 AM EDT Sun Aug 24 2025 ...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING... .REST OF TONIGHT...S winds around 10 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: E 5 ft at 11 seconds and SW 2 ft at 4 seconds. .SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: E 4 ft at 11 seconds and S 3 ft at 4 seconds. .SUN NIGHT...SE winds 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: S 3 ft at 6 seconds and E 3 ft at 10 seconds. A chance of showers after midnight with vsby 1 to 3 NM. .MON...E winds 10 to 15 kt, becoming W in the afternoon. Seas 3 to 4 ft, building to 4 to 6 ft in the afternoon. Wave Detail: SE 3 ft at 5 seconds and SE 3 ft at 9 seconds, becoming S 5 ft at 8 seconds and S 2 ft at 5 seconds. A chance of showers. Patchy fog in the morning with vsby 1 to 3 NM. .MON NIGHT...W winds 10 to 15 kt. Seas 4 to 6 ft. Wave Detail: S 5 ft at 8 seconds and E 3 ft at 8 seconds. .TUE AND TUE NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. Wave Detail: S 5 ft at 8 seconds and W 3 ft at 4 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ256-241800- Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 nm South of Block Island- 105 AM EDT Sun Aug 24 2025 ...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING... .REST OF TONIGHT...S winds 10 to 15 kt. Seas 4 to 5 ft. Wave Detail: E 5 ft at 12 seconds and S 2 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 5 ft at 11 seconds and S 3 ft at 4 seconds. .SUN NIGHT...S winds 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: SE 4 ft at 12 seconds and S 3 ft at 6 seconds. A chance of showers after midnight. .MON...SE winds 5 to 10 kt, becoming SW in the afternoon. Seas 3 to 4 ft, building to 4 to 6 ft in the afternoon. Wave Detail: SE 3 ft at 6 seconds and E 2 ft at 10 seconds, becoming SE 5 ft at 7 seconds and E 2 ft at 10 seconds. A chance of showers in the morning. .MON NIGHT AND TUE...W winds 10 to 15 kt with gusts up to 20 kt. Seas 4 to 6 ft. Wave Detail: S 5 ft at 8 seconds and W 3 ft at 4 seconds. .TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 kt, becoming NW after midnight. Seas 3 to 4 ft. Wave Detail: W 3 ft at 4 seconds and SE 3 ft at 11 seconds. .WED THROUGH THU NIGHT...SW 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. $$ ANZ232-241800- Nantucket Sound- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Wave Detail: E 3 ft at 11 seconds and SW 2 ft at 4 seconds. .SUN...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 11 seconds. .SUN NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas 2 to 3 ft. Wave Detail: S 2 ft at 4 seconds and E 2 ft at 11 seconds. A chance of showers after midnight. .MON...SE winds around 10 kt, becoming SW in the afternoon. Seas 2 to 3 ft. Wave Detail: SE 2 ft at 4 seconds and S 2 ft at 8 seconds. A chance of showers. .MON NIGHT AND TUE...SW winds 15 to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at 8 seconds. .TUE NIGHT...W winds 15 to 20 kt, becoming NW 10 to 15 kt after midnight. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 1 foot at 7 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ233-241800- Vineyard Sound- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at 4 seconds and E 2 ft at 13 seconds. .SUN...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 2 ft at 12 seconds. .SUN NIGHT...S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at 4 seconds and S 1 foot at 7 seconds. A chance of showers after midnight. .MON...SE winds 5 to 10 kt, becoming SW 10 to 15 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: S 2 ft at 9 seconds and S 1 foot at 3 seconds. A chance of showers. .MON NIGHT AND TUE...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: S 3 ft at 8 seconds and SW 2 ft at 5 seconds. .TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 kt, becoming NW after midnight. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and S 2 ft at 7 seconds. .WED THROUGH THU 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. $$ ANZ234-241800- Buzzards Bay- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds around 10 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at 12 seconds. .SUN...S winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at 12 seconds. .SUN NIGHT...S winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas 2 to 3 ft. Wave Detail: S 2 ft at 3 seconds and E 2 ft at 10 seconds. Patchy fog after midnight. A chance of showers after midnight. .MON...SE winds 5 to 10 kt, becoming SW 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas around 2 ft. Wave Detail: S 2 ft at 9 seconds and S 1 foot at 3 seconds. A chance of showers. .MON NIGHT...SW winds 10 to 15 kt, becoming W after midnight. Seas 2 to 3 ft. Wave Detail: SE 2 ft at 8 seconds and S 2 ft at 8 seconds. .TUE AND TUE NIGHT...NW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 4 ft. Wave Detail: SW 2 ft at 5 seconds and E 2 ft at 8 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ235-241800- Rhode Island Sound- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds 10 to 15 kt. Seas 2 to 4 ft. Wave Detail: SW 3 ft at 4 seconds and SE 2 ft at 13 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 4 seconds and SE 2 ft at 13 seconds. .SUN NIGHT...S winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: S 3 ft at 6 seconds and E 1 foot at 9 seconds. Patchy fog after midnight. A chance of showers after midnight. .MON...SE winds 5 to 10 kt, becoming SW in the afternoon. Seas 2 to 4 ft. Wave Detail: S 4 ft at 9 seconds and SE 3 ft at 5 seconds. Patchy fog in the morning. A chance of showers in the morning. .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 SE 3 ft at 8 seconds. .TUE AND TUE NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Wave Detail: S 4 ft at 8 seconds and SE 3 ft at 8 seconds. .WED THROUGH THU 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. $$ ANZ237-241800- Block Island Sound- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds around 10 kt. Seas 3 to 4 ft. Wave Detail: SE 3 ft at 12 seconds and SW 2 ft at 4 seconds. .SUN...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon. Seas 2 to 4 ft. Wave Detail: SE 3 ft at 12 seconds and SW 2 ft at 4 seconds. .SUN NIGHT...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 13 seconds and S 2 ft at 4 seconds. Patchy fog after midnight. .MON...S winds 5 to 10 kt, becoming SW in the afternoon. Seas 2 to 4 ft. Wave Detail: SE 3 ft at 8 seconds and SE 2 ft at 5 seconds. A chance of showers in the morning. .MON NIGHT...SW winds around 10 kt, becoming NW after midnight. Seas 3 to 5 ft. Wave Detail: S 4 ft at 8 seconds and SE 2 ft at 8 seconds. .TUE AND TUE NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Wave Detail: S 4 ft at 8 seconds and SE 3 ft at 8 seconds. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ230-241800- Boston Harbor- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds 10 to 15 kt. Waves around 2 ft. .SUN...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon. Waves around 2 ft. .SUN NIGHT...S winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt after midnight. Waves around 2 ft in the evening, then 1 foot or less. A chance of. .MON...SE winds 5 to 10 kt. Waves 1 foot or less, then around 2 ft in the afternoon. A chance of showers. .MON NIGHT...SW winds 5 to 10 kt, becoming W after midnight. Waves 1 foot or less. A chance of showers in the evening. .TUE AND TUE NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft. .WED THROUGH THU NIGHT...SW 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. $$ ANZ236-241800- Narragansett Bay- 105 AM EDT Sun Aug 24 2025 .REST OF TONIGHT...S winds around 10 kt. Waves around 2 ft. .SUN...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon. Waves 2 to 3 ft. .SUN NIGHT...S winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt after midnight. Waves around 2 ft. Patchy fog after midnight. .MON...S winds 5 to 10 kt. Waves 2 to 3 ft. A chance of showers. .MON NIGHT...SW winds around 10 kt, becoming NW after midnight. Waves 2 to 3 ft. .TUE AND TUE NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt. Waves 2 to 3 ft. .WED THROUGH THU NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ 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