Coastal Waters Forecast
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
404 FZMY50 PGUM 300849 AAA CWFGUM Coastal Waters Forecast for the Mariana Islands...UPDATED National Weather Service Tiyan GU 649 PM ChST Sun Nov 30 2025 Marianas Waters out to 40 nautical miles PMZ150-302200- 649 PM ChST Sun Nov 30 2025 Updated discussion and north swell tonight. .Synopsis for Marianas Waters... Moderate to fresh trades will prevail across the region through Tuesday night, as a tropical disturbance is expected to maintain scattered showers and isolated thunderstorms over the next couple days, mainly across Guam and Rota. Combined seas of 7 to 9 feet are expected through Wednesday as northerly swell moves through the region, generated by a distant low pressure system. Afterwards, conditions gradually subside to gentle to moderate winds and 5 to 7 foot seas late week. $$ PMZ151-152-302200- Guam Coastal Waters-Rota Coastal Waters- 649 PM ChST Sun Nov 30 2025 .TONIGHT...East wind 10 to 20 kt. Seas 6 to 8 ft. Wave Detail: East 6 ft at 8 seconds, east 4 ft at 6 seconds and north 4 ft at 14 seconds. Scattered showers with isolated thunderstorms. .MONDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, northeast 5 ft at 14 seconds and east 4 ft at 5 seconds. Scattered showers with isolated thunderstorms. .MONDAY NIGHT...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, northeast 5 ft at 13 seconds and east 4 ft at 6 seconds. Scattered showers with isolated thunderstorms. .TUESDAY AND TUESDAY NIGHT...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, northeast 5 ft at 13 seconds and east 4 ft at 6 seconds. .WEDNESDAY...East wind 15 kt. Seas 7 to 9 ft. Wave Detail: East 7 ft at 8 seconds, east 3 ft at 6 seconds and northeast 3 ft at 13 seconds. A chance of showers. .THURSDAY...East wind 10 to 15 kt. Seas 6 to 8 ft. Wave Detail: East 6 ft at 8 seconds, east 3 ft at 5 seconds and northeast 3 ft at 13 seconds. A chance of showers with a slight chance of thunderstorms. .FRIDAY...East wind 10 to 15 kt. Seas 5 to 7 ft. Wave Detail: East 5 ft at 8 seconds, east 3 ft at 4 seconds and northeast 3 ft at 13 seconds. A chance of showers. $$ PMZ153-154-302200- Tinian Coastal Waters-Saipan Coastal Waters- 649 PM ChST Sun Nov 30 2025 .TONIGHT...East wind 15 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, north 5 ft at 14 seconds and east 3 ft at 5 seconds. Scattered showers. .MONDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, northeast 5 ft at 14 seconds and east 4 ft at 5 seconds. Scattered showers. .MONDAY NIGHT THROUGH TUESDAY NIGHT...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail: East 6 ft at 8 seconds, northeast 5 ft at 13 seconds and east 4 ft at 6 seconds. .WEDNESDAY...Southeast wind 15 kt. Seas 7 to 9 ft. Wave Detail: East 7 ft at 8 seconds, northeast 4 ft at 13 seconds and southeast 3 ft at 5 seconds. .THURSDAY...East wind 10 to 15 kt. Seas 6 to 8 ft. Wave Detail: East 6 ft at 8 seconds, east 3 ft at 5 seconds and northeast 3 ft at 13 seconds. A chance of showers. .FRIDAY...East wind 10 to 15 kt. Seas 5 to 7 ft. Wave Detail: East 5 ft at 8 seconds, east 3 ft at 4 seconds and northeast 3 ft at 13 seconds. $$