FZMY50 PGUM 231851
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
451 AM ChST Mon Aug 24 2026

Marianas Waters out to 40 nautical miles

PMZ150-241000-
451 AM ChST Mon Aug 24 2026

.Synopsis for Marianas Waters...
Significant southwesterly swell driven by the monsoon pattern and
Tropical Depression 19W, well north-northwest of Yap, along with 
strong, convectively-driven gust will give way to choppy seas of 
7 to 10 feet through this afternoon. Combined seas are expected to
gradually subside to 5 to 7 feet around midweek, then 4 to 6 feet
late week. Gentle to moderate winds become light to moderate 
beginning Tuesday. An unsettled, but disorganized monsoon pattern 
continues to bring scattered showers and isolated thunderstorms 
across the Marianas this week, with showers becoming numerous and 
locally heavy at times.

$$

PMZ151>154-241000-
MARIANAS COASTAL WATERS-
451 AM ChST Mon Aug 24 2026

...SMALL CRAFT ADVISORY IN EFFECT THROUGH LATE THIS AFTERNOON...

.TODAY...Southwest wind 10 to 15 kt with gusts to 25 kt near
heavier showers. Seas 7 to 10 ft. Wave Detail: Southwest 8 ft at 
10 seconds, southwest 4 ft at 4 seconds, southeast 3 ft at 8 
seconds and north 4 ft at 10 seconds. Scattered showers in the 
morning, then numerous showers in the afternoon. Isolated 
thunderstorms.
.TONIGHT...Southwest wind 10 to 15 kt with gusts to 25 kt
near heavier showers. Seas 7 to 9 ft. Wave Detail: Southwest 8 ft
at 10 seconds, north 4 ft at 10 seconds, southwest 3 ft at 4 
seconds and east 2 ft at 12 seconds. Numerous showers in the 
evening, then scattered showers after midnight. Isolated 
thunderstorms. Locally heavy showers possible. 
.TUESDAY...Southwest wind 5 to 10 kt. Seas 7 to 9 ft. Wave 
Detail: Southwest 7 ft at 10 seconds, northwest 3 ft at 10 
seconds, east 3 ft at 12 seconds and southwest 2 ft at 4 seconds. 
Scattered heavy showers with isolated thunderstorms. 
.TUESDAY NIGHT...Southwest wind 5 to 10 kt. Seas 5 to 7 ft. Wave
Detail: Southwest 6 ft at 9 seconds, east 3 ft at 12 seconds, 
southwest 2 ft at 4 seconds and northwest 2 ft at 10 seconds. 
Scattered heavy showers with isolated thunderstorms. 
.WEDNESDAY...Southwest wind 5 to 10 kt. Seas 4 to 6 ft. Wave
Detail: Southwest 5 ft at 10 seconds, east 3 ft at 12 seconds, 
southwest 2 ft at 4 seconds and northwest 2 ft at 10 seconds. A 
chance of showers with a slight chance of thunderstorms. 
.THURSDAY AND FRIDAY...West wind 5 to 15 kt. Seas 4 to 6 ft.
Wave Detail: West 4 ft at 10 seconds, west 3 ft at 4 seconds and 
northeast 3 ft at 12 seconds. Showers likely with a slight chance 
of thunderstorms.  

$$