221
FZMY50 PGUM 120713
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
513 PM ChST Mon Oct 12 2026

Marianas Waters out to 40 nautical miles

PMZ150-122230-
513 PM ChST Mon Oct 12 2026

.Synopsis for Marianas Waters...
Combined seas of 4 to 5 feet look to decrease through midweek to
as low as 3 feet. Swells consist of a dominant north swell from
distant Typhoon Koguma and a smaller northeast swell. Seas are
expected to increase significantly sometime Friday ahead of
Invest 96W. Light northwest winds will continue to ease today,
becoming east to northeast by early Wednesday and gradually
increasing through the end of the forecast period.

$$

PMZ151>154-122230-
MARIANAS COASTAL WATERS-
513 PM ChST Mon Oct 12 2026

.TONIGHT...West wind 5 kt. Seas 4 to 5 ft. Wave Detail: North 4
ft at 10 seconds and northeast 2 ft at 10 seconds.
.TUESDAY...Southeast wind 5 kt. Seas around 4 ft. Wave Detail:
North 3 ft at 10 seconds and northeast 2 ft at 10 seconds.
.TUESDAY NIGHT...Southeast wind 5 kt. Seas 3 to 4 ft. Wave
Detail: Northeast 2 ft at 9 seconds and north 3 ft at 10 seconds.
.WEDNESDAY...East wind 5 kt. Seas around 3 ft. Wave Detail: East
2 ft at 9 seconds and north 2 ft at 9 seconds.
.WEDNESDAY NIGHT...East wind 5 kt. Seas around 3 ft. Wave Detail:
East 2 ft at 9 seconds and north 2 ft at 9 seconds.
.THURSDAY...Northeast wind 5 to 15 kt. Seas around 3 ft. Wave Detail:
Northeast 2 ft at 4 seconds, east 2 ft at 9 seconds and north 2 ft
at 9 seconds.
.FRIDAY...Northeast wind 10 to 20 kt. Seas 4 to 6 ft. Wave Detail:
Northeast 5 ft at 9 seconds and northeast 3 ft at 5 seconds. A chance
of showers and a slight chance of thunderstorms.
.SATURDAY...Northeast wind 30 kt. Seas 9 to 12 ft. Wave Detail:
Northeast 8 ft at 4 seconds, northeast 5 ft at 9 seconds and east
4 ft at 10 seconds. Heavy showers likely with a slight chance of
thunderstorms.

$$