654
FZMY50 PGUM 210616
CWFGUM

Coastal Waters Forecast for the Mariana Islands
National Weather Service Tiyan GU
416 PM ChST Sun Sep 21 2025

Marianas Waters out to 40 nautical miles

PMZ150-212000-
416 PM ChST Sun Sep 21 2025

.Synopsis for Marianas Waters...Gentle to moderate easterlies will
prevail the next few days, as multiple minor troughs extending
from Invest 92W to the southwest, will make their way across the
region. Combined seas of 4 to 5 feet will increase another few
feet around midweek as various swells generated by distant
typhoons finally make it to the Marianas and mix in with the
background trade swell.

$$

PMZ151>154-212000-
MARIANAS COASTAL WATERS-
416 PM ChST Sun Sep 21 2025

.TONIGHT...East wind 10 to 15 kt. Seas 4 to 5 ft. Wave Detail:
West 3 ft at 9 seconds, east 3 ft at 4 seconds and east 2 ft at 9
seconds. Scattered showers with isolated thunderstorms.
.MONDAY...East wind 5 to 15 kt with gusts to 25 kt near heavier
showers. Seas 4 to 5 ft. Wave Detail: Southwest 4 ft at 10
seconds, east 3 ft at 4 seconds and east 2 ft at 8 seconds.
Numerous showers with isolated thunderstorms. Locally hevay
showers possible.
.MONDAY NIGHT...East wind 5 to 15 kt. Seas 4 to 6 ft. Wave
Detail: North 4 ft at 10 seconds, East 3 ft at 8 seconds and east
3 ft at 4 seconds. Scattered showers with isolated thunderstorms.
.TUESDAY AND TUESDAY NIGHT...East wind 10 kt. Seas 4 to 6 ft.
Wave Detail: North 4 ft at 10 seconds, east 3 ft at 8 seconds and
east 2 ft at 4 seconds. Scattered showers.
.WEDNESDAY...East wind 10 kt. Seas 4 to 6 ft. Wave Detail: North
4 ft at 10 seconds, east 3 ft at 8 seconds and east 2 ft at
4 seconds.
.THURSDAY...Southeast wind 5 to 10 kt. Seas 5 to 7 ft. Wave
Detail: Northeast 6 ft at 11 seconds, east 3 ft at 8 seconds and
east 2 ft at 4 seconds.
.FRIDAY...Southeast wind 5 to 10 kt. Seas 4 to 6 ft. Wave Detail:
Northeast 5 ft at 12 seconds and southeast 2 ft at 4 seconds. A
chance of showers with a slight chance of thunderstorms.

$$