766
FZMY50 PGUM 180533
CWFGUM

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

Marianas Waters out to 40 nautical miles

PMZ150-182200-
333 PM 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.

$$

PMZ151-152-182200-
Guam Coastal Waters-Rota Coastal Waters-
333 PM ChST Tue Nov 18 2025

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

$$

PMZ153-154-182200-
Tinian Coastal Waters-Saipan Coastal Waters-
333 PM ChST Tue Nov 18 2025

.TONIGHT...East wind 15 kt with gusts to 25 kt. Seas 6 to 7 ft.
Wave Detail: East 6 ft at 8 seconds and east 3 ft at 4 seconds.
.WEDNESDAY...East wind 15 to 20 kt. Seas 5 to 7 ft. Wave Detail:
East 6 ft at 8 seconds and east 3 ft at 4 seconds.
.WEDNESDAY NIGHT...East wind 20 kt. Seas 6 to 8 ft. Wave Detail:
East 6 ft at 8 seconds and east 3 ft at 5 seconds.
.THURSDAY...East wind 20 kt. Seas 6 to 8 ft. Wave Detail: East
7 ft at 8 seconds and east 3 ft at 4 seconds.
.THURSDAY NIGHT...East wind 20 kt. Seas 7 to 9 ft. Wave Detail:
East 7 ft at 8 seconds and east 4 ft at 4 seconds. Isolated
thunderstorms.
.FRIDAY...East wind 20 kt. Seas 8 to 10 ft. Wave Detail: East 8
ft at 8 seconds, east 5 ft at 4 seconds and north 3 ft at 11
seconds. Scattered 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 5 ft at 4 seconds and north 2 ft at
11 seconds. A chance of showers with a slight chance of
thunderstorms.
.SUNDAY...East wind 20 kt. Seas 7 to 9 ft. Wave Detail: East 8 ft
at 9 seconds and east 4 ft at 4 seconds.

$$