820
FZMY50 PGUM 261926
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
526 AM ChST Sun Jul 27 2025

Marianas Waters out to 40 nautical miles

PMZ150-270930-
526 AM ChST Sun Jul 27 2025

.Synopsis for Marianas Waters...Recent altimetry passes and local
buoys are showing seas 12 to 18 feet in the coastal waters, which
is in the Hazardous Seas criteria of 15+ feet. Will reissue and
extend the Hazardous Seas Warning for Rota, Tinian and Saipan
through today, with a Small Craft Advisory then in effect through
Monday. The Small Craft Advisory was also extended for Guam
through Monday as well. Conditions will begin to improve early
this week from south to north across the Marianas as TS Krosa and
the monsoon surge lift slowly north.

$$

PMZ151-270930-
Guam Coastal Waters-
526 AM ChST Sun Jul 27 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH MONDAY AFTERNOON...

.TODAY...Southwest wind 15 to 20 kt with gusts to 30 kt. Seas
10 to 12 ft. Wave Detail: West 11 ft at 10 seconds, southwest
5 ft at 6 seconds and east 2 ft at 9 seconds. Scattered showers
with isolated thunderstorms.
.TONIGHT...Southwest wind 15 to 20 kt. Seas 8 to 10 ft. Wave
Detail: West 9 ft at 10 seconds, southwest 3 ft at 5 seconds and
east 2 ft at 9 seconds.
.MONDAY...Southwest wind 10 to 20 kt. Seas 7 to 10 ft. Wave
Detail: West 8 ft at 10 seconds, southwest 4 ft at 5 seconds and
east 2 ft at 9 seconds. Isolated thunderstorms.
.MONDAY NIGHT...Southwest wind 10 to 15 kt. Seas 4 to 6 ft. Wave
Detail: West 5 ft at 10 seconds, southwest 3 ft at 4 seconds and
east 2 ft at 9 seconds. Isolated thunderstorms.
.TUESDAY THROUGH WEDNESDAY...Southwest wind 5 to 15 kt. Seas 5 to
7 ft. Wave Detail: West 6 ft at 10 seconds, southwest 2 ft at
4 seconds and east 2 ft at 9 seconds. A slight chance of
thunderstorms.
.THURSDAY...Southwest wind 5 to 10 kt. Seas 4 to 6 ft. Wave
Detail: West 5 ft at 10 seconds and east 2 ft at 9 seconds. A
slight chance of thunderstorms.

$$

PMZ152>154-270930-
Rota Coastal Waters-Tinian Coastal Waters-Saipan Coastal Waters-
526 AM ChST Sun Jul 27 2025

...HAZARDOUS SEAS WARNING IN EFFECT THROUGH LATE THIS AFTERNOON...
...SMALL CRAFT ADVISORY IN EFFECT FROM THIS EVENING THROUGH
MONDAY AFTERNOON...

.TODAY...Southwest wind 20 to 25 kt. Seas 13 to 18 ft. Scattered
showers with isolated thunderstorms.
.TONIGHT...Southwest wind 15 to 20 kt with gusts to 30 kt. Seas
9 to 11 ft. Wave Detail: West 9 ft at 10 seconds, southwest 5 ft
at 6 seconds and east 2 ft at 9 seconds. Scattered showers with
isolated thunderstorms.
.MONDAY...Southwest wind 15 to 20 kt with gusts to 30 kt. Seas 7
to 10 ft. Wave Detail: West 8 ft at 10 seconds, southwest 4 ft at
6 seconds and east 2 ft at 9 seconds. Isolated thunderstorms.
.MONDAY NIGHT...Southwest wind 15 kt. Seas 6 to 8 ft. Wave
Detail: West 7 ft at 10 seconds, southwest 3 ft at 5 seconds and
east 2 ft at 9 seconds. Isolated thunderstorms.
.TUESDAY...Southwest wind 10 to 15 kt. Seas 6 to 8 ft. Wave
Detail: West 7 ft at 10 seconds, southwest 3 ft at 5 seconds and
east 2 ft at 9 seconds. Isolated thunderstorms.
.WEDNESDAY THROUGH THURSDAY...Southwest wind 5 to 15 kt. Seas
5 to 7 ft. Wave Detail: West 6 ft at 10 seconds, southwest 2 ft
at 4 seconds and east 2 ft at 9 seconds. A slight chance of
thunderstorms.

$$