178
FZMY50 PGUM 020437
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
237 PM ChST Fri Oct 2 2026

Marianas Waters out to 40 nautical miles

PMZ150-022230-
237 PM ChST Fri Oct 2 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 Tropical Storm 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.

$$

PMZ151-152-022230-
Guam Coastal Waters-Rota Coastal Waters-
237 PM ChST Fri Oct 2 2026

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

.TONIGHT...Southwest wind 20 to 30 kt with frequent gusts to 40
kt. Seas 14 to 17 ft. Scattered showers with isolated
thunderstorms.
.SATURDAY...Southwest wind 20 to 30 kt with frequent gusts to 40
kt. Seas 14 to 17 ft. Scattered showers with isolated
thunderstorms.
.SATURDAY NIGHT...Southwest wind 30 kt with occasional gusts to
40 kt. Seas 13 to 16 ft. Scattered showers with isolated
thunderstorms.
.SUNDAY AND SUNDAY NIGHT...Southwest wind 30 kt. Seas 12 to 14
ft. Scattered showers with isolated thunderstorms.
.MONDAY...Southwest wind 20 to 25 kt. Seas 10 to 13 ft. Wave
Detail: West 11 ft at 10 seconds, southwest 6 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.

$$

PMZ153-154-022230-
Tinian Coastal Waters-Saipan Coastal Waters-
237 PM ChST Fri Oct 2 2026

...TROPICAL STORM WARNING IN EFFECT...

.TONIGHT...Southwest tropical storm force wind 40 kt with gusts
to 60 kt. Seas 17 to 20 ft. Widespread locally heavy showers with
isolated thunderstorms.
.SATURDAY...Southwest tropical storm force wind 35 kt with gusts
to 50 kt. Seas 17 to 20 ft. Scattered showers with isolated
thunderstorms.
.SATURDAY NIGHT...Southwest wind 30 kt with occasional gusts to
40 kt. Seas 16 to 18 ft. Scattered showers with isolated
thunderstorms.
.SUNDAY...Southwest wind 30 kt with occasional gusts to 40 kt.
Seas 15 to 17 ft. Scattered showers with isolated thunderstorms.
.SUNDAY NIGHT...Southwest wind 30 kt. Seas 14 to 16 ft. Scattered
showers with isolated thunderstorms.
.MONDAY...Southwest wind 20 to 25 kt. Seas 11 to 14 ft. 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.

$$