821
FZMY50 PGUM 171837
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
437 AM ChST Tue Nov 18 2025

Marianas Waters out to 40 nautical miles

PMZ150-180900-
437 AM ChST Tue Nov 18 2025

.Synopsis for Marianas Waters...
Moderate to fresh trade winds are expected throughout the week.
Combined seas of 5 to 7 feet will remain steady before increasing
Thursday into late week. Seas and winds could become hazardous to
small craft by Friday as they approach 10 ft and 22 kt,
respectively.

$$

PMZ151-152-180900-
Guam Coastal Waters-Rota Coastal Waters-
437 AM ChST Tue Nov 18 2025

.TODAY...East wind 15 kt. Seas 6 to 7 ft. Wave Detail: Northeast
6 ft at 8 seconds and east 3 ft at 5 seconds.
.TONIGHT...East wind 15 kt. Seas 6 to 7 ft. Wave Detail: East 6
ft at 8 seconds and east 3 ft at 5 seconds.
.WEDNESDAY...East wind 15 kt. Seas 6 to 8 ft. Wave Detail:
Northeast 7 ft at 8 seconds and east 3 ft at 5 seconds.
.WEDNESDAY NIGHT...East wind 15 to 20 kt. Seas 6 to 8 ft. Wave
Detail: East 7 ft at 8 seconds and east 4 ft at 5 seconds.
.THURSDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail:
East 8 ft at 9 seconds and east 4 ft at 6 seconds.
.FRIDAY AND SATURDAY...East wind 15 to 20 kt. Seas 7 to 10 ft.
Wave Detail: East 8 ft at 9 seconds, east 4 ft at 4 seconds and
north 3 ft at 11 seconds. A chance of showers with a slight
chance of thunderstorms.

$$

PMZ153-154-180900-
Tinian Coastal Waters-Saipan Coastal Waters-
437 AM ChST Tue Nov 18 2025

.TODAY...East wind 15 kt. Seas 6 to 7 ft. Wave Detail: Northeast
6 ft at 8 seconds and east 3 ft at 5 seconds.
.TONIGHT...East wind 15 kt. Seas 6 to 7 ft. Wave Detail: East 6
ft at 8 seconds and east 3 ft at 5 seconds.
.WEDNESDAY...East wind 15 kt. Seas 6 to 8 ft. Wave Detail:
Northeast 7 ft at 8 seconds and east 3 ft at 5 seconds.
.WEDNESDAY NIGHT...East wind 15 to 20 kt. Seas 6 to 8 ft. Wave
Detail: East 7 ft at 8 seconds and east 4 ft at 5 seconds.
.THURSDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail:
East 8 ft at 9 seconds and east 4 ft at 6 seconds. A chance of
showers with a slight chance of thunderstorms.
.FRIDAY...East wind 15 to 20 kt. Seas 8 to 10 ft. Wave Detail:
East 8 ft at 9 seconds, east 4 ft at 4 seconds and north 3 ft at
11 seconds. A chance of showers with a slight chance of
thunderstorms.
.SATURDAY...East wind 15 to 20 kt. Seas 8 to 10 ft. Wave Detail:
East 8 ft at 9 seconds, east 4 ft at 4 seconds and north 3 ft at
11 seconds.

$$