


Coastal Waters Forecast
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
699 FZMY50 PGUM 110656 CWFGUM Coastal Waters Forecast for the Mariana Islands National Weather Service Tiyan GU 456 PM ChST Sat Oct 11 2025 Marianas Waters out to 40 nautical miles PMZ150-112300- 456 PM ChST Sat Oct 11 2025 .Synopsis for Marianas Waters... Combined seas will remain at around 4 to 6 feet through the period, comprised of a long-period north swell and a secondary trade swell. Winds will be gentle to moderate out of the northeast to east through the weekend, becoming moderate to fresh at times early next week as a weak disturbance lifts northwest through the area. Seas may increase by a foot or so around Tuesday with an expected increase in winds and wind waves. $$ PMZ151>154-112300- MARIANAS COASTAL WATERS- 456 PM ChST Sat Oct 11 2025 .TONIGHT...East to northeast wind 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: North 5 ft at 14 seconds, east 3 ft at 8 seconds and northeast 2 ft at 4 seconds. .SUNDAY AND SUNDAY NIGHT...East wind 10 kt. Seas 4 to 6 ft. Wave Detail: North 4 ft at 13 seconds, east 3 ft at 8 seconds and east 2 ft at 4 seconds. .MONDAY...East wind 10 to 15 kt. Seas 4 to 6 ft. Wave Detail: North 4 ft at 12 seconds, east 3 ft at 8 seconds and east 3 ft at 4 seconds. .MONDAY NIGHT...East wind 15 kt. Seas 4 to 6 ft. Wave Detail: North 4 ft at 11 seconds, east 3 ft at 5 seconds and east 3 ft at 8 seconds. Scattered showers. .TUESDAY...East to southeast wind 15 to 20 kt. Seas 4 to 7 ft. Wave Detail: East 4 ft at 8 seconds, north 4 ft at 11 seconds and east 4 ft at 5 seconds. A chance of showers with a slight chance of thunderstorms. .WEDNESDAY...Southeast wind 15 kt. Seas 4 to 6 ft. Wave Detail: East 4 ft at 8 seconds, north 4 ft at 11 seconds and east 3 ft at 5 seconds. Showers likely with a slight chance of thunderstorms. Locally heavy showers possible. .THURSDAY...East to southeast wind 10 to 15 kt. Seas 4 to 6 ft. Wave Detail: East 4 ft at 8 seconds, north 4 ft at 12 seconds and east 3 ft at 4 seconds. A chance of showers with a slight chance of thunderstorms. $$