FZUS51 KBOX 092302 CWFBOX Coastal Waters Forecast for Massachusetts and Rhode Island National Weather Service Boston/Norton MA 702 PM EDT Thu Apr 9 2026 Coastal waters from the Merrimack River MA to Watch Hill RI out to 25 NM ANZ200-101200- 702 PM EDT Thu Apr 9 2026 .Synopsis for Massachusetts and Rhode Island coastal waters... Large high pres moves E of the waters tonight and Fri. A cold front crosses the waters late Fri into early Sat, followed by another high pres building in Sat night and Sun. This high will then slide E of the waters Sun night, with a warm front moving across the waters by early Mon. A backdoor front will drop S into northern New Eng Tue. $$ ANZ250-101200- Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary- 702 PM EDT Thu Apr 9 2026 ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 2 AM EDT FRIDAY... .TONIGHT...S winds 15 to 20 kt, becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Seas 2 to 3 ft. .FRI...S winds 10 to 15 kt, increasing to 15 to 20 kt with gusts up to 25 kt in the afternoon. Seas 2 to 3 ft, building to 3 to 5 ft in the afternoon. .FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 4 to 6 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt. Gusts up to 20 kt in the morning. Seas 4 to 5 ft. .SAT NIGHT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt after midnight. Seas 4 to 5 ft. .SUN...NW winds 5 to 10 kt, becoming S 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 3 to 4 ft. .SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 3 to 5 ft. A chance of showers after midnight. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to 6 ft. A chance of showers. .MON NIGHT...SW winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 6 ft. .TUE AND TUE NIGHT...SW winds 10 to 15 kt, becoming S 15 to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ251-101200- Massachusetts Bay and Ipswich Bay- 702 PM EDT Thu Apr 9 2026 ...SMALL CRAFT ADVISORY IN EFFECT UNTIL 2 AM EDT FRIDAY... .TONIGHT...S winds 15 to 20 kt, becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Seas 2 to 3 ft. .FRI...S winds 10 to 15 kt. Gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds 15 to 20 kt. Seas 3 to 4 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt. Gusts up to 20 kt in the morning. Seas 3 to 4 ft. .SAT NIGHT...NW winds 10 to 15 kt, diminishing to 5 to 10 kt after midnight. Seas 2 to 4 ft. .SUN...W winds around 5 kt, becoming S 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. .SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. A chance of showers after midnight. .MON...SW winds 20 to 25 kt. Seas 3 to 4 ft. A chance of showers. .MON NIGHT AND TUE...SW winds 15 to 20 kt with gusts up to 25 kt, diminishing to 10 to 15 kt. Seas 2 to 4 ft. .TUE NIGHT...SW 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. $$ ANZ231-101200- Cape Cod Bay- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 10 to 15 kt, becoming SW 5 to 10 kt after midnight. Gusts up to 20 kt. Seas around 2 ft. .FRI...S winds 10 to 15 kt, becoming SW 15 to 20 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Gusts up to 25 kt. Seas 2 to 4 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas 2 to 3 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas 2 to 3 ft. .SUN...NW winds around 5 kt, becoming S in the afternoon. Seas around 2 ft. .SUN NIGHT...S winds 10 to 15 kt, increasing to 15 to 20 kt after midnight. Gusts up to 25 kt. Seas 2 to 4 ft. A chance of showers after midnight. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to 5 ft. .MON NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. .TUE AND TUE NIGHT...SW winds 10 to 15 kt. Gusts up to 20 kt. Seas around 2 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ254-101200- Coastal waters from Provincetown MA to Chatham MA to Nantucket MA out 20 nm- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 10 to 15 kt, diminishing to 5 to 10 kt after midnight. Gusts up to 20 kt. Seas 2 to 4 ft. .FRI...SW winds 5 to 10 kt, increasing to 15 to 20 kt in the afternoon. Seas 3 to 5 ft. .FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas 4 to 6 ft. .SAT...NW winds 10 to 15 kt. Gusts up to 20 kt in the morning. Seas 4 to 6 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas 3 to 5 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to 6 ft. .MON NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to 7 ft. .TUE...SW winds 15 to 20 kt. Seas 4 to 6 ft. .TUE NIGHT...SW winds 15 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. $$ ANZ255-101200- Coastal Waters extending out to 25 nm South of Marthas Vineyard and Nantucket- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt, diminishing to around 5 kt after midnight. Seas 2 to 4 ft. .FRI...S winds 5 to 10 kt, becoming SW 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 4 ft. .FRI NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. .SAT...NW winds 10 to 15 kt. Gusts up to 20 kt in the morning. Seas 4 to 6 ft. Patchy fog in the morning with vsby 1 to 3 NM. .SAT NIGHT...N winds 5 to 10 kt. Seas 3 to 5 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to 8 ft. .MON NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 6 to 9 ft. .TUE...SW winds 15 to 20 kt. Seas 5 to 7 ft. .TUE NIGHT...SW winds 15 to 20 kt. Seas 3 to 5 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ256-101200- Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 nm South of Block Island- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt, diminishing to around 5 kt after midnight. Seas 2 to 3 ft. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt in the afternoon. Seas 3 to 4 ft. .FRI NIGHT...SW winds 15 to 20 kt. Seas 3 to 5 ft. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas 4 to 6 ft. .SAT NIGHT...NW winds around 10 kt, becoming N after midnight. Seas 3 to 5 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 3 to 5 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to 7 ft. .MON NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 6 to 9 ft. .TUE...SW winds 15 to 20 kt. Seas 5 to 7 ft. .TUE NIGHT...SW winds 15 to 20 kt. Seas 4 to 5 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. $$ ANZ232-101200- Nantucket Sound- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt. Seas around 2 ft. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds around 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, becoming N 5 to 10 kt in the afternoon. Seas 2 to 4 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas 2 to 3 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt. Seas 2 to 3 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to 5 ft. .MON NIGHT...SW winds 20 to 25 kt. Seas 4 to 6 ft. .TUE AND TUE NIGHT...SW winds 10 to 15 kt. Gusts up to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ233-101200- Vineyard Sound- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt. Seas 1 foot or less, then around 2 ft after midnight. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas around 2 ft. .FRI NIGHT...SW winds 15 to 20 kt. Seas 2 to 3 ft. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas 2 to 3 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas around 2 ft. .SUN...NW winds around 5 kt, becoming S in the afternoon. Seas around 2 ft. .SUN NIGHT...S winds 10 to 15 kt, increasing to 15 to 20 kt with gusts up to 25 kt after midnight. Seas 2 to 4 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to 6 ft. .MON NIGHT...SW winds 20 to 25 kt. Seas 5 to 7 ft. .TUE...SW winds 15 to 20 kt. Seas 3 to 5 ft. .TUE 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. $$ ANZ234-101200- Buzzards Bay- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt. Seas 1 foot or less. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 25 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds 15 to 20 kt. Seas 2 to 3 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas around 2 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas around 2 ft. .SUN...NW winds around 5 kt, becoming S 10 to 15 kt in the afternoon. Seas 1 foot or less, then around 2 ft in the afternoon. .SUN NIGHT...S winds 10 to 15 kt, increasing to 15 to 20 kt with gusts up to 25 kt after midnight. Seas 2 to 4 ft. .MON AND MON NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to 5 ft. .TUE AND TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ235-101200- Rhode Island Sound- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt. Seas around 2 ft. .FRI...SW winds 5 to 10 kt, increasing to around 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds 15 to 20 kt. Seas 2 to 4 ft. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas 2 to 4 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas 2 to 3 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. .MON...SW winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to 6 ft. .MON NIGHT...SW winds 20 to 25 kt. Seas 5 to 7 ft. .TUE AND TUE NIGHT...SW winds 15 to 20 kt. Seas 3 to 5 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. $$ ANZ237-101200- Block Island Sound- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 5 to 10 kt. Seas around 2 ft. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 2 to 3 ft. .FRI NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. .SAT...NW winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt in the afternoon. Seas 2 to 4 ft. .SAT NIGHT...N winds 5 to 10 kt. Seas 2 to 4 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. .MON AND MON NIGHT...SW winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 6 ft. .TUE...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 5 ft. .TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ230-101200- Boston Harbor- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft this evening, then 1 foot or less. .FRI...SW winds 10 to 15 kt. Gusts up to 20 kt in the afternoon. Waves around 2 ft. .FRI NIGHT...SW winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Waves around 2 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt. Gusts up to 20 kt in the morning. Waves around 2 ft. .SAT NIGHT...NW winds 10 to 15 kt, diminishing to 5 to 10 kt after midnight. Waves around 2 ft in the evening, then 1 foot or less. .SUN...W winds around 5 kt, becoming S 10 to 15 kt in the afternoon. Waves 1 foot or less, then around 2 ft in the afternoon. .SUN NIGHT...S winds 10 to 15 kt, increasing to 15 to 20 kt after midnight. Gusts up to 25 kt. Waves around 2 ft. A chance of showers. .MON...SW winds 20 to 25 kt. Waves around 2 ft. A chance of showers. .MON NIGHT THROUGH TUE NIGHT...SW winds 15 to 20 kt with gusts up to 25 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. $$ ANZ236-101200- Narragansett Bay- 702 PM EDT Thu Apr 9 2026 .TONIGHT...S winds 10 to 15 kt, becoming SW around 5 kt after midnight. Waves 1 foot or less, then around 2 ft after midnight. .FRI...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Waves around 2 ft. .FRI NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Waves 2 to 3 ft. A chance of showers after midnight. .SAT...NW winds 10 to 15 kt. Waves 2 to 3 ft. .SAT NIGHT...N winds 5 to 10 kt. Waves around 2 ft. .SUN AND SUN NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Waves 2 to 3 ft. .MON THROUGH TUE NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Waves 2 to 4 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ For the latest updates...please visit our webpage at www.weather.gov/boston You can follow us on Facebook at www.facebook.com/us.nationalweatherservice.boston.gov You can follow us on Twitter at @NWSBoston