


Coastal Waters Forecast
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
852 FZMY50 PGUM 111046 AAA CWFGUM Coastal Waters Forecast for the Mariana Islands...UPDATED National Weather Service Tiyan GU 846 PM ChST Mon Aug 11 2025 Marianas Waters out to 40 nautical miles PMZ150-112030- 846 PM ChST Mon Aug 11 2025 .Synopsis for Marianas Waters...Light to gentle winds are expected through the week. Combined seas of 3 to 4 feet will slowly subside, dropping to between 2 and 3 feet Tuesday night. An upper-level low will produce isolated thunderstorms through Wednesday. $$ PMZ151>154-112030- MARIANAS COASTAL WATERS- 846 PM ChST Mon Aug 11 2025 Updated to add scattered showers to Guam waters this evening. .REST OF TONIGHT...East wind 5 to 10 kt. Seas 3 to 4 ft. Wave Detail: East 3 ft at 8 seconds and east 2 ft at 4 seconds. Scattered showers for Guam waters. Isolated thunderstorms. .TUESDAY...Southeast wind 5 to 10 kt. Seas 3 to 4 ft. Wave Detail: East 4 ft at 8 seconds and east 2 ft at 4 seconds. Isolated thunderstorms. .TUESDAY NIGHT...East wind 5 kt. Seas around 3 ft. Wave Detail: East 3 ft at 8 seconds. Isolated thunderstorms. .WEDNESDAY...East wind 5 kt. Seas around 3 ft. Wave Detail: East 3 ft at 9 seconds. Isolated thunderstorms. .WEDNESDAY NIGHT...East wind 5 kt. Seas around 3 ft. Wave Detail: East 3 ft at 9 seconds. .THURSDAY THROUGH SATURDAY...East wind 5 to 10 kt. Seas around 3 ft. Wave Detail: East 3 ft at 9 seconds and east 2 ft at 4 seconds. $$