FZMY50 PGUM 160019 CWFGUM Coastal Waters Forecast for the Mariana Islands National Weather Service Tiyan GU 1019 AM ChST Fri Oct 16 2026 Marianas Waters out to 40 nautical miles PMZ150-160900- 1019 AM ChST Fri Oct 16 2026 .Synopsis for Marianas Waters... A Typhoon Watch remains in effect for Guam, Rota, Tinian and Saipan waters. Gentle to fresh northeasterlies will prevail across the Marianas through tonight, followed by quickly deteriorating conditions as Tropical Storm Champi (29W) makes its way across the Marianas, potentially as a typhoon Saturday night through Sunday evening. As such, seas are expected to quickly rise, with significant sea heights reaching as high as 35 feet during closest passage of Champi, producing dangerous seas possibly into Monday. $$ PMZ151-152-160900- Guam Coastal Waters-Rota Coastal Waters- 1019 AM ChST Fri Oct 16 2026 ...TYPHOON WATCH IN EFFECT... .TODAY...Northeast wind 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: Northeast 4 ft at 8 seconds and northeast 3 ft at 5 seconds. .TONIGHT...Northeast wind 10 to 15 kt with gusts to 25 kt. Seas 4 to 6 ft. Wave Detail: Northeast 5 ft at 9 seconds and northeast 3 ft at 4 seconds. .SATURDAY...North wind 10 to 20 kt with gusts to 40 kt. Seas 5 to 7 ft. Wave Detail: North 5 ft at 5 seconds and northeast 5 ft at 9 seconds. Isolated thunderstorms. .SATURDAY NIGHT...North tropical storm force wind to 45 kt with gusts to 70 kt. Seas 9 to 15 ft. Scattered showers and isolated thunderstorms. Visibility 1 NM or less after midnight. .SUNDAY...Typhoon force wind possible. South tropical storm force wind to 50 kt with gusts to 80 kt. Seas 15 to 23 ft. Widespread showers with torrential rain, becoming scattered showers by midnight. Isolated thunderstorms. Visibility 1 NM or less. .MONDAY...Southeast wind 15 to 25 kt. Seas 10 to 15 ft. A chance of showers with a slight chance of thunderstorms. .TUESDAY...East wind 10 to 20 kt. Seas 8 to 10 ft. Wave Detail: Southwest 9 ft at 8 seconds and east 5 ft at 5 seconds. A chance of showers. $$ PMZ153-154-160900- Tinian Coastal Waters-Saipan Coastal Waters- 1019 AM ChST Fri Oct 16 2026 ...TYPHOON WATCH IN EFFECT... .TODAY...Northeast wind 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: Northeast 4 ft at 9 seconds and northeast 3 ft at 4 seconds. .TONIGHT...Northeast wind 10 to 20 kt with gusts to 30 kt. Seas 5 to 7 ft. Wave Detail: Northeast 5 ft at 9 seconds and northeast 4 ft at 5 seconds. .SATURDAY...Northeast wind 15 to 25 kt with gusts to 40 kt. Seas 6 to 8 ft. Wave Detail: Northeast 7 ft at 7 seconds and northeast 6 ft at 9 seconds. Isolated thunderstorms. .SATURDAY NIGHT...Northeast tropical storm force wind to 35 kt with gusts to 60 kt. Seas 8 to 15 ft. Scattered showers with isolated thunderstorms. .SUNDAY...East to southeast tropical storm force wind to 40 kt with gusts to 65 kt. Seas 15 to 23 ft. Numerous showers becoming scattered near midnight. Isolated thunderstorms. .MONDAY...Southeast wind 15 to 25 kt. Seas 14 to 17 ft. A chance of showers with a slight chance of thunderstorms. .TUESDAY...East wind 10 to 20 kt. Seas 8 to 11 ft. Wave Detail: Southwest 9 ft at 9 seconds and east 5 ft at 4 seconds. A chance of showers. $$