Coastal Waters Forecast
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
804 FZMY50 PGUM 170614 CWFGUM Coastal Waters Forecast for the Mariana Islands National Weather Service Tiyan GU 414 PM ChST Thu Jul 17 2025 Marianas Waters out to 40 nautical miles PMZ150-172200- 414 PM ChST Thu Jul 17 2025 .Synopsis for Marianas Waters...Gentle to moderate east to southeast winds will continue across the region through the weekend. The west-southwest swell has been slower to build in, so seas of 4 to 6 feet are expected to continue. If the swell comes in a bit higher than projected over the weekend, seas could rise to 5 to 7 feet. The TUTT is now passing through the Marianas, and the instability associated with it could help to generate isolated thunderstorms across the coastal waters through the weekend. $$ PMZ151>154-172200- MARIANAS COASTAL WATERS- 414 PM ChST Thu Jul 17 2025 .TONIGHT...East wind 10 kt. Seas 4 to 6 ft. Wave Detail: East 5 ft at 8 seconds, east 2 ft at 4 seconds and west 2 ft at 7 seconds. Isolated thunderstorms. Scattered showers late this evening and overnight. .FRIDAY...East wind 10 to 15 kt. Seas 4 to 5 ft. Wave Detail: East 4 ft at 8 seconds, east 3 ft at 4 seconds and west 2 ft at 7 seconds. Scattered showers with isolated thunderstorms. .FRIDAY NIGHT...East wind 10 to 15 kt with gusts to 25 kt. Seas 4 to 5 ft. Wave Detail: East 3 ft at 5 seconds, east 3 ft at 8 seconds and west 2 ft at 7 seconds. Isolated thunderstorms. .SATURDAY...East wind 10 kt. Seas 4 to 5 ft. Wave Detail: East 4 ft at 8 seconds, east 2 ft at 4 seconds and west 2 ft at 7 seconds. Scattered showers with isolated thunderstorms. .SATURDAY NIGHT...Southeast wind 5 to 15 kt. Seas 4 to 5 ft. Wave Detail: East 4 ft at 8 seconds, east 3 ft at 4 seconds and west 2 ft at 9 seconds. Scattered showers with isolated thunderstorms. .SUNDAY THROUGH MONDAY...Southeast wind 5 to 10 kt. Seas 4 to 5 ft. Wave Detail: West 4 ft at 9 seconds, east 3 ft at 8 seconds and southeast 2 ft at 4 seconds. A chance of showers with a slight chance of thunderstorms. .TUESDAY...Southeast wind 5 kt. Seas 3 to 4 ft. Wave Detail: West 4 ft at 8 seconds and northeast 2 ft at 8 seconds. A slight chance of thunderstorms. $$