Tinian Coastal Waters

PMZ153 · Coastal Waters Forecast, National Weather Service Tiyan GU · issued Wed, Sep 30, 6:22 PM GMT+10

Small Craft Advisory in force. Tonight: Northwest wind 10 to 20 kt. Seas 6 to 8 ft. Wave Detail: Southwest 6 ft at 8 seconds, northeast 3 ft at 10 seconds and northwest 4 ft at 4 seconds. Scattered showers with isolated thunderstorms.

Tinian Coastal Waters on the map

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Small Craft Advisory

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Alerts in force

Small Craft Advisory from Thu, Oct 1, 5:00 PM GMT+10 until Sun, Oct 4, 5:00 PM GMT+10

Small Craft Advisory issued September 30 at 6:24PM ChST until October 4 at 5:00PM ChST by NWS Tiyan GU

The full text

* WHAT...Southwest winds 20 to 30 kt with gusts up to 40 kt and seas
10 to 14 feet expected.

* WHERE...Marianas Coastal Waters.

* WHEN...From 5 PM Thursday to 5 PM ChST Sunday.

* IMPACTS...Conditions will be hazardous to small craft.

* ADDITIONAL DETAILS...Combined seas will rapidly increase through
Thursday with 10 to 12 ft forecasted Thursday night, peaking to 14
ft over the weekend. West to southwest winds will be moderate to
strong with gusts up to gale-force possible for Saipan and Tinian.
The onset of these conditions is not expected until Thursday
evening, therefore the Small Craft Advisory will be in effect
starting Thursday 5 PM ChST and continue through the weekend.

Inexperienced mariners, especially those operating smaller
vessels, should avoid boating in hazardous conditions.

The forecast

Coastal Waters Forecast from National Weather Service Tiyan GU, issued Wed, Sep 30, 6:22 PM GMT+10, valid until Thu, Oct 1, 8:00 AM GMT+10. Wind in knots, seas in feet.

SMALL CRAFT ADVISORY IN EFFECT FROM 5 PM THURSDAY TO 5 PM CHST SUNDAY

INCREASING SHOWERS, WINDS, AND SEAS EXPECTED THURSDAY NIGHT THROUGH SUNDAY NIGHT AS TD 26W APPROACHES NORTHERN CNMI

Tonight: Northwest wind 10 to 20 kt. Seas 6 to 8 ft. Wave Detail: Southwest 6 ft at 8 seconds, northeast 3 ft at 10 seconds and northwest 4 ft at 4 seconds. Scattered showers with isolated thunderstorms.
Thursday: Northwest wind 20 to 25 kt. Seas 8 to 9 ft. Wave Detail: Southwest 7 ft at 8 seconds, northwest 5 ft at 5 seconds and north 3 ft at 10 seconds. Scattered showers with isolated thunderstorms.
Thursday night: West wind 25 to 30 kt with gusts to 40 kt. Seas 10 to 12 ft. Wave Detail: Southwest 9 ft at 8 seconds, west 7 ft at 6 seconds and north 4 ft at 11 seconds. Numerous showers with isolated thunderstorms.
Friday and Friday night: Southwest wind 25 to 30 kt with gusts to 40 kt. Seas 12 to 14 ft. Numerous showers with isolated thunderstorms.
Saturday: Southwest wind 25 to 30 kt with gusts to 40 kt. Seas 12 to 14 ft. Showers likely with a slight chance of thunderstorms.
Sunday: Southwest wind 25 to 30 kt with gusts to 40 kt. Seas 10 to 12 ft. Wave Detail: Southwest 8 ft at 6 seconds, west 8 ft at 9 seconds and northwest 4 ft at 13 seconds. A chance of showers with a slight chance of thunderstorms.
Monday: Southwest wind 20 to 25 kt. Seas 8 to 9 ft. Wave Detail: Southwest 6 ft at 6 seconds, west 5 ft at 9 seconds and northwest 3 ft at 13 seconds. A slight chance of thunderstorms.

Synopsis

Synopsis for Marianas Waters

Gentle to moderate westerlies will shift to the southwest and strengthen to moderate to fresh beginning Thursday night. Combined seas of 6 to 8 ft tonight will rapidly increase to 10 to 12 ft Thursday night as Tropical Depression (TD) 26W approaches the northern CNMI and brings an elevated southwesterly monsoon swell to the Marianas. Therefore, a Small Craft Advisory will be in effect starting Thursday evening. A Hazardous Seas Warning may have to be issued for the weekend if combined seas reach 15 ft or greater. Mariners should continue monitoring the forecast for changes in the coming days.

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.

The archive of past products did not answer just now.

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 Tinian Beaches Every Guam and Micronesia zone

Sources

Coastal Waters Forecast CWFGUM from National Weather Service Tiyan GU, issued Wed, Sep 30, 6:22 PM GMT+10. 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 10:18 UTC. All public domain, from the National Weather Service.