323
FZMY50 PGUM 291801
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
401 AM ChST Mon Jun 30 2025

Marianas Waters out to 40 nautical miles

PMZ150-301115-
401 AM ChST Mon Jun 30 2025

.Synopsis for Marianas Waters...A developing monsoon disturbance
to the northeast of the islands will keep a wet southwesterly
pattern across the Marianas. Combined seas of 4 to 5 feet look to
increase a foot or two today into Tuesday as a southwest monsoon
swell and winds build into the region.

$$

PMZ151-152-301115-
Guam Coastal Waters-Rota Coastal Waters-
401 AM ChST Mon Jun 30 2025

.TODAY...South wind 10 to 15 kt. Seas 4 to 6 ft. Wave Detail:
East 4 ft at 8 seconds, south 3 ft at 4 seconds and southwest
3 ft at 8 seconds. Isolated thunderstorms. Scattered showers this
morning, then numerous locally heavy showers this afternoon.
.TONIGHT...Southwest wind 10 to 15 kt. Seas around 6 ft. Wave
Detail: East 4 ft at 8 seconds, southwest 3 ft at 5 seconds and
southwest 3 ft at 8 seconds. Numerous locally heavy showers with
isolated thunderstorms.
.TUESDAY...Southwest wind 10 to 15 kt. Seas 5 to 6 ft. Wave
Detail: East 4 ft at 8 seconds, southwest 4 ft at 8 seconds and
southwest 3 ft at 4 seconds. Scattered showers with isolated
thunderstorms.
.TUESDAY NIGHT...Southwest wind 10 to 15 kt. Seas 4 to 6 ft. Wave
Detail: Southwest 4 ft at 8 seconds, east 3 ft at 8 seconds and
southwest 3 ft at 4 seconds. Scattered showers with isolated
thunderstorms.
.WEDNESDAY THROUGH FRIDAY...South wind 5 to 15 kt. Seas 4 to
5 ft. Wave Detail: East 4 ft at 8 seconds, southwest 3 ft at 8
seconds and southwest 3 ft at 4 seconds. A chance of showers with
a slight chance of thunderstorms.


$$

PMZ153-154-301115-
Tinian Coastal Waters-Saipan Coastal Waters-
401 AM ChST Mon Jun 30 2025

.TODAY...South wind 10 to 15 kt. Seas around 5 ft. Wave Detail:
East 4 ft at 8 seconds, southwest 3 ft at 8 seconds and south
2 ft at 4 seconds. Scattered showers with isolated thunderstorms.
.TONIGHT...South wind 10 to 15 kt. Seas around 6 ft. Wave Detail:
East 4 ft at 8 seconds, south 3 ft at 5 seconds and southwest
3 ft at 8 seconds. Numerous locally heavy showers with isolated
thunderstorms.
.TUESDAY...Southwest wind 15 to 20 kt. Seas 5 to 6 ft. Wave
Detail: East 4 ft at 8 seconds, southwest 4 ft at 8 seconds and
southwest 3 ft at 5 seconds. Numerous locally heavy showers with
isolated thunderstorms.
.TUESDAY NIGHT...Southwest wind 15 kt. Seas 4 to 6 ft. Wave
Detail: West 4 ft at 8 seconds, southwest 3 ft at 5 seconds and
east 3 ft at 8 seconds. Scattered showers with isolated
thunderstorms.
.WEDNESDAY THROUGH FRIDAY...South wind 5 to 15 kt. Seas 4 to
5 ft. Wave Detail: Southwest 3 ft at 8 seconds, southwest 3 ft at
5 seconds and east 3 ft at 8 seconds. A chance of showers with a
slight chance of thunderstorms.

$$