Block Island Sound

ANZ237 · Coastal Waters Forecast, National Weather Service Boston/Norton MA · issued Sat, Sep 26, 10:03 PM EDT

Storm Warning in force. Overnight: NE winds 25 to 30 kt with gusts up to 55 kt. Seas 7 to 10 ft. Wave Detail: NE 10 ft at 8 seconds and SW 1 foot at 10 seconds. Patchy fog. A chance of tstms. Showers. Vsby 1 to 3 NM, decreasing to 1 NM or less.

Block Island Sound on the map

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Storm Warning

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Now

The nearest stations reporting each, as of Sat, Sep 26, 11:18 PM EDT.

Wind: NNE 22 kt, gusts 30 kt at NWPR1
Water: 65°F at MTKN6

Alerts in force

Storm Warning from Sat, Sep 26, 12:26 PM EDT until Sun, Sep 27, 10:00 AM EDT

Storm Warning issued September 26 at 12:26PM EDT until September 27 at 10:00AM EDT by NWS Boston/Norton MA

The full text

* WHAT...Northeast winds 25 to 35 kt with gusts up to 55 kt and
seas 6 to 9 feet.

* WHERE...In Massachusetts coastal waters, Nantucket Sound,
Vineyard Sound and Buzzards Bay. In Rhode Island coastal
waters, Rhode Island Sound and Block Island Sound.

* WHEN...Until 10 AM EDT Sunday.

* IMPACTS...Storm force winds and hazardous seas will capsize or
damage vessels and reduce visibility.

Mariners should remain in port, alter course, and/or secure the
vessel for severe conditions.

The forecast

Coastal Waters Forecast from National Weather Service Boston/Norton MA, issued Sat, Sep 26, 10:03 PM EDT, valid until Sun, Sep 27, 11:00 AM EDT. Wind in knots, seas in feet.

STORM WARNING IN EFFECT UNTIL 10 AM EDT SUNDAY

Overnight: NE winds 25 to 30 kt with gusts up to 55 kt. Seas 7 to 10 ft. Wave Detail: NE 10 ft at 8 seconds and SW 1 foot at 10 seconds. Patchy fog. A chance of tstms. Showers. Vsby 1 to 3 NM, decreasing to 1 NM or less.
Sunday: NE winds 20 to 25 kt, diminishing to 15 to 20 kt in the afternoon. Gusts up to 50 kt. Seas 6 to 9 ft. Wave Detail: S 9 ft at 8 seconds and E 9 ft at 8 seconds. Patchy fog. Showers likely. Vsby 1 to 3 NM.
Sunday night: NE winds 15 to 20 kt with gusts up to 30 kt. Seas 4 to 6 ft. Wave Detail: E 6 ft at 8 seconds and S 4 ft at 8 seconds. Patchy fog. Showers. Vsby 1 to 3 NM in the evening.
Monday: E winds 15 to 20 kt, diminishing to 10 to 15 kt in the afternoon. Seas 3 to 5 ft. Wave Detail: SE 4 ft at 7 seconds and E 3 ft at 9 seconds. Showers. Patchy fog in the morning.
Monday night: SE winds 10 to 15 kt, becoming SW after midnight. Seas 3 to 4 ft. Wave Detail: S 3 ft at 7 seconds and E 2 ft at 9 seconds. Showers likely in the evening.
Tuesday and Tuesday night: NW winds 5 to 10 kt. Seas 2 to 4 ft. Wave Detail: W 3 ft at 6 seconds and E 2 ft at 9 seconds.
Wednesday through Thursday night: SW 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.

Synopsis

Synopsis for Massachusetts and Rhode Island coastal waters

A slow moving Nor'easter will continue to bring dangerous conditions for Mariners through the weekend. NE wind gusts of 40 to 60 kt with maximum seas of 15-25 feet across the open waters continue into early Sun. NE winds will only gradually diminish to Gale Force levels on Sun and finally back to small craft levels by Mon. Seas slowly diminish Sun into Mon...but remain well above small craft advisory thresholds.

Winds and seas will finally drop below small craft for the middle and latter half of the upcoming work week as the Nor'easter finally loses its grip on our region.

Buoys and stations nearby

The latest report from each station within reach of the zone, nearest first. Distances in nautical miles from the middle of the zone.

Station	Distance	Wind	Water	Air	Pressure	Reported
MTKN6 8510560 - Montauk, NY	18 nm		65°F		1002.7 hPa	Sat, Sep 26, 11:18 PM EDT
NWPR1 8452660 - Newport, RI	22 nm	NNE 22 kt, gusts 30	63°F		1005.2 hPa	Sat, Sep 26, 11:18 PM EDT
NLHC3 8461490 - New London, CT	22 nm		64°F		1004.0 hPa	Sat, Sep 26, 11:18 PM EDT
PDVR1 8454123 - Port of Davisville, RI	25 nm	N 20 kt, gusts 29			1005.9 hPa	Sat, Sep 26, 11:18 PM EDT
NAXR1 Potters Cove, Narragansett Bay Reserve, RI	28 nm	SSW 19 kt		59°F	1006.0 hPa	Sat, Sep 26, 11:00 PM EDT
PTCR1 8452951 - Potter Cove, Prudence Island, RI	28 nm	ENE 15 kt, gusts 22			1005.8 hPa	Sat, Sep 26, 11:18 PM EDT

The past year

Warnings, watches and advisories the National Weather Service issued for this zone over the past 12 months, from the Iowa Environmental Mesonet’s archive.

Product	Issued	Most recent
Gale Warning	32	Wed, Sep 23, 2026, 5:00 AM EDT
Special Marine Warning	9	Fri, Sep 4, 2026, 5:41 AM EDT
Storm Warning	6	Fri, Sep 25, 2026, 2:00 AM EDT
Freezing Spray Warning	1	Sat, Feb 7, 2026, 4:00 PM EST
Gale Watch	21	Tue, Sep 22, 2026, 2:00 PM EDT
Storm Watch	4	Fri, Sep 25, 2026, 2:00 AM EDT
Freezing Spray Watch	1	Sat, Feb 7, 2026, 4:00 PM EST
Severe Thunderstorm Watch	1	Sat, Jul 4, 2026, 7:20 PM EDT
Small Craft Advisory	83	Tue, Sep 22, 2026, 8:00 AM EDT
Freezing Spray Advisory	7	Mon, Mar 2, 2026, 1:00 AM EST

What this means

Marine forecasts give wind in knots (1 knot is 1.15 mph) and seas in feet, except the high seas forecasts, which give seas in meters. Seas are the significant wave height, the average of the highest third of the waves; individual waves may be more than twice that. On the Great Lakes the forecast gives waves, not seas. "Wave Detail" splits the seas into the wind waves and each swell, with its direction and period.

Each coastal office writes a Coastal Waters Forecast for the bays, sounds and ocean out to 20 to 60 nautical miles, or on the Great Lakes a Nearshore Marine Forecast within 5 nautical miles of shore; the Open Lakes Forecast covers the rest of each lake. The Ocean Prediction Center and the National Hurricane Center write the Offshore Waters Forecasts out to about 250 nautical miles, and the High Seas Forecasts beyond. Forecasts are issued at least twice a day and updated when they go wrong.

Small Craft Advisory: Winds or conditions hazardous to small boats. The thresholds are set by each NWS region: typically sustained winds or frequent gusts of 20 to 25 knots up to 33 knots, and seas of 5 to 7 feet or more.
Gale Warning: Sustained winds or frequent gusts of 34 to 47 knots, not from a tropical cyclone.
Storm Warning: Sustained winds or frequent gusts of 48 to 63 knots, not from a tropical cyclone.
Hurricane Force Wind Warning: Sustained winds or frequent gusts of 64 knots or more, not from a tropical cyclone.
Special Marine Warning: A thunderstorm or squall over the water with winds or gusts of 34 knots or more, hail of 3/4 inch or more, or a waterspout, for up to two hours.
Hazardous Seas Warning: Wave heights or steepness at or above the office’s warning threshold, when the wind alone does not warrant a warning.
Heavy Freezing Spray Warning: Spray freezing on a vessel at 2 cm (3/4 inch) an hour or more.
Tropical Storm and Hurricane Warnings: Tropical storm (34 to 63 knots) or hurricane (64 knots or more) conditions expected within 36 hours. Watches: possible within 48 hours.

Nearby

Open the live map with marine zones and buoys The hour-by-hour forecast for the middle of the zone Block Island Area Beaches Narragansett, Charlestown and Westerly Beaches Newport Area Beaches Every Atlantic Coast zone

Sources

Coastal Waters Forecast CWFBOX from National Weather Service Boston/Norton MA, issued Sat, Sep 26, 10:03 PM EDT. Original at NWS. Buoy reports from the National Data Buoy Center. Past products from the Iowa Environmental Mesonet. Zone outlines from the NWS marine and offshore zone boundaries. Warnings and advisories from the NWS API, read 03:57 UTC. All public domain, from the National Weather Service.