121
FZMY50 PGUM 220611
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
411 PM ChST Tue Jul 22 2025

Marianas Waters out to 40 nautical miles

PMZ150-222200-
411 PM ChST Tue Jul 22 2025

.Synopsis for Marianas Waters...Gentle to moderate east to
southeast winds look to persist through Wednesday. Winds then
look to strengthen through the latter half of the week as
tropical disturbance Invest 98W approaches the region. Combined
seas of 4 to 6 feet, comprised mainly of a primary easterly swell
and secondary westerly swell, are expected to increase
through the second half of the week as 98W develops near the
region, leading to hazardous sea conditions. Uncertainty remains
high at this time regarding winds and sea state development
toward the weekend, as conditions may change significantly over
the coming days.

$$

PMZ151>154-222200-
MARIANAS COASTAL WATERS-
411 PM ChST Tue Jul 22 2025

.TONIGHT...East to southeast wind 5 to 15 kt. Seas 4 to 6 ft.
Wave Detail: East 4 ft at 8 seconds, east 3 ft at 4 seconds and
west 2 ft at 8 seconds. Scattered showers with isolated
thunderstorms.
.WEDNESDAY...East to southeast wind 5 to 15 kt. Seas 4 to 6 ft.
Wave Detail: East 5 ft at 8 seconds, southeast 3 ft at 4 seconds
and west 2 ft at 8 seconds. Scattered showers with isolated
thunderstorms.
.WEDNESDAY NIGHT...Northeast to east wind 5 to 10 kt. Seas 4 to 6
ft. Wave Detail: East 5 ft at 8 seconds and northeast 2 ft at 4
seconds. Scattered showers with isolated thunderstorms.
.THURSDAY...Northwest to north wind 10 to 20 kt. Seas 4 to 6 ft.
Wave Detail: East 5 ft at 8 seconds and north 4 ft at 4 seconds.
Numerous locally heavy showers with isolated thunderstorms.
.THURSDAY NIGHT...Northwest wind 10 to 20 kt with gusts to 30 kt.
Seas 5 to 7 ft. Wave Detail: East 5 ft at 8 seconds and northwest
4 ft at 5 seconds. Numerous showers with isolated thunderstorms.
.FRIDAY THROUGH SATURDAY...West to southwest wind 15 to 25 kt.
Seas 6 to 8 ft. Wave Detail: East 5 ft at 8 seconds, west 5 ft at
5 seconds, and northeast 3 ft at 8 seconds. Locally heavy showers
likely with a slight chance of thunderstorms.
.SUNDAY...Southwest wind 15 to 20 kt. Seas 5 to 7 ft. Wave
Detail: West 5 ft at 8 seconds, southwest 4 ft at 5 seconds, and
east 3 ft at 9 seconds. A chance of showers with a slight chance
of thunderstorms.

$$