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FZMY50 PGUM 021800
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
400 AM ChST Sat Oct 3 2026

Marianas Waters out to 40 nautical miles

PMZ150-030930-
400 AM ChST Sat Oct 3 2026

.Synopsis for Marianas Waters...
Strong to gale force southwesterlies will continue. Combined seas
of 15 to 20 ft will persist through Saturday, then begin to
gradually diminish as Typhoon Choi-wan (26W) moves away from the
northern CNMI and brings elevated southwest monsoon swell to the
Marianas. For Saipan and Tinian, a Tropical Storm Warning remains
in effect. For Guam and Rota, a Gale Warning remains in effect.
Mariners should continue monitoring the forecast for changes in
the coming days.

$$

PMZ151-152-030930-
Guam Coastal Waters-Rota Coastal Waters-
400 AM ChST Sat Oct 3 2026

...GALE WARNING IN EFFECT THROUGH LATE THIS AFTERNOON...
...HAZARDOUS SEAS WATCH IN EFFECT FROM THIS AFTERNOON THROUGH
SUNDAY AFTERNOON...

.TODAY...Southwest wind 25 to 35 kt with gusts to 50 kt. Seas 15
to 18 ft. Scattered showers with isolated thunderstorms. Locally
heavy showers possible.
.TONIGHT...Southwest wind 20 to 30 kt with gusts to 40 kt. Seas
13 to 16 ft. Scattered showers with isolated thunderstorms.
.SUNDAY...Southwest wind 20 to 30 kt. Seas 12 to 14 ft. Scattered
showers with isolated thunderstorms.
.SUNDAY NIGHT...Southwest wind 30 kt. Seas 11 to 13 ft. Wave
Detail: West 10 ft at 9 seconds, southwest 7 ft at 8 seconds and
northwest 3 ft at 13 seconds. Scattered showers with isolated
thunderstorms.
.MONDAY...Southwest wind 20 to 25 kt. Seas 10 to 12 ft. Wave
Detail: West 10 ft at 10 seconds, southwest 7 ft at 8 seconds and
northwest 3 ft at 13 seconds. A chance of showers with a slight
chance of thunderstorms.
.TUESDAY...Southwest wind 15 to 20 kt. Seas 8 to 10 ft. Wave
Detail: West 8 ft at 9 seconds, southwest 4 ft at 6 seconds and
northwest 3 ft at 13 seconds. A chance of showers with a slight
chance of thunderstorms.
.WEDNESDAY...West wind 10 to 15 kt. Seas 6 to 8 ft. Wave Detail:
West 6 ft at 9 seconds, southwest 3 ft at 4 seconds and northwest
3 ft at 13 seconds. A chance of showers with a slight chance of
thunderstorms.

$$

PMZ153-154-030930-
Tinian Coastal Waters-Saipan Coastal Waters-
400 AM ChST Sat Oct 3 2026

...TROPICAL STORM WARNING IN EFFECT...

.TODAY...Southwest tropical storm force wind to 45 kt. Gusts up
to 60 kt. Seas 17 to 20 ft. Numerous locally heavy showers and
scattered thunderstorms.
.TONIGHT...Southwest wind 30 kt with gusts to 45 kt. Seas 16 to
18 ft. Scattered showers with isolated thunderstorms.
.SUNDAY...Southwest wind 30 kt with gusts to 40 kt. Seas 14 to
16 ft. Scattered showers with isolated thunderstorms.
.SUNDAY NIGHT...Southwest wind 30 kt. Seas 13 to 15 ft. Scattered
showers with isolated thunderstorms.
.MONDAY...Southwest wind 20 to 25 kt. Seas 11 to 13 ft. Wave
Detail: West 11 ft at 9 seconds, southwest 7 ft at 8 seconds and
northwest 3 ft at 13 seconds. A slight chance of thunderstorms.
.TUESDAY...Southwest wind 10 to 20 kt. Seas 8 to 10 ft. Wave
Detail: West 9 ft at 9 seconds, southwest 4 ft at 6 seconds and
northwest 3 ft at 13 seconds. A chance of showers with a slight
chance of thunderstorms.
.WEDNESDAY...West wind 5 to 15 kt. Seas 5 to 7 ft. Wave Detail:
West 6 ft at 9 seconds, northwest 3 ft at 13 seconds and west
2 ft at 4 seconds. A chance of showers with a slight chance of
thunderstorms.

$$