FZMY50 PGUM 220622

CWFGUM



Coastal Waters Forecast for the Mariana Islands

National Weather Service Tiyan GU

422 PM ChST Sun Mar 22 2026



Marianas Waters out to 40 nautical miles



PMZ150-222200-

422 PM ChST Sun Mar 22 2026



.Synopsis for Marianas Waters...

Elevated northeast to east swell and wind waves, and long-period 

north to northeast swell continues to produce hazardous seas up 

to 11 feet through Tuesday afternoon. Winds will be moderate to 

strong through Tuesday, then gradually diminishing to gentle to 

moderate late week. Convergence north of a tropical disturbance 

is expected to bring an increase in showers tonight through 

Wednesday, with a higher shower coverage and thunderstorm 

potential for Guam and Rota Monday through Tuesday. 



$$



PMZ151-152-222200-

Guam Coastal Waters-Rota Coastal Waters-

422 PM ChST Sun Mar 22 2026



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



.TONIGHT...Northeast wind 15 to 25 kt. Seas 8 to 10 ft. Wave 

Detail: Northeast 7 ft at 8 seconds, northeast 6 ft at 6 seconds,

northeast 3 ft at 12 seconds and north 2 ft at 11 seconds. 

Scattered showers. 

.MONDAY...East wind 15 to 25 kt. Seas 8 to 10 ft. Wave Detail:

Northeast 7 ft at 8 seconds, east 6 ft at 6 seconds and northeast

3 ft at 12 seconds. Numerous showers for Guam waters, scattered

showers for Rota waters. Isolated thunderstorms. Locally heavy

showers possible.

.MONDAY NIGHT...Northeast wind 15 to 20 kt with gusts to 30 kt.

Seas 8 to 10 ft. Wave Detail: East 8 ft at 8 seconds, northeast

5 ft at 6 seconds and northeast 3 ft at 11 seconds. Scattered

showers with isolated thunderstorms. 

.TUESDAY...Northeast wind 10 to 20 kt. Seas 7 to 10 ft. Wave

Detail: East 8 ft at 8 seconds, northeast 4 ft at 5 seconds,

north 3 ft at 10 seconds and northeast 2 ft at 11 seconds.

Scattered showers with isolated thunderstorms. 

.TUESDAY NIGHT...Northeast wind 10 to 20 kt. Seas 7 to 9 ft. Wave

Detail: East 7 ft at 8 seconds, north 4 ft at 9 seconds,

northeast 3 ft at 5 seconds and northeast 2 ft at 11 seconds.

Scattered showers. 

.WEDNESDAY...Northeast wind 10 to 20 kt. Seas 6 to 8 ft. Wave

Detail: East 6 ft at 8 seconds, northeast 4 ft at 6 seconds,

north 3 ft at 11 seconds and northeast 2 ft at 10 seconds.

Scattered showers.

.THURSDAY...Northeast wind 10 to 20 kt. Seas 5 to 7 ft. Wave

Detail: East 6 ft at 8 seconds, northeast 4 ft at 5 seconds and

north 2 ft at 10 seconds. 

.FRIDAY...Northeast wind 10 to 15 kt. Seas 4 to 6 ft. Wave 

Detail: East 4 ft at 8 seconds, north 3 ft at 11 seconds and 

northeast 3 ft at 4 seconds. 



$$



PMZ153-154-222200-

Tinian Coastal Waters-Saipan Coastal Waters-

422 PM ChST Sun Mar 22 2026



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



.TONIGHT...Northeast wind 15 to 25 kt. Seas 8 to 10 ft. Wave 

Detail: Northeast 7 ft at 8 seconds, northeast 6 ft at 7 seconds, 

northeast 3 ft at 12 seconds and north 2 ft at 11 seconds.

Scattered showers. 

.MONDAY...Northeast wind 20 to 25 kt. Seas 8 to 10 ft. Wave

Detail: Northeast 7 ft at 8 seconds, northeast 6 ft at 7 seconds

and northeast 3 ft at 12 seconds. Scattered showers through late

morning.

.MONDAY NIGHT...Northeast wind 15 to 25 kt. Seas 9 to 11 ft. Wave

Detail: East 8 ft at 8 seconds, northeast 6 ft at 7 seconds and 

northeast 3 ft at 11 seconds.

.TUESDAY...Northeast wind 20 kt. Seas 8 to 10 ft. Wave Detail:

East 8 ft at 8 seconds, northeast 5 ft at 6 seconds, north 3 ft at

10 seconds and northeast 2 ft at 11 seconds. Scattered showers.

.TUESDAY NIGHT...Northeast wind 15 to 20 kt. Seas 7 to 9 ft. Wave

Detail: East 7 ft at 8 seconds, northeast 4 ft at 6 seconds,

north 4 ft at 9 seconds and northeast 2 ft at 11 seconds.

Scattered showers. 

.WEDNESDAY...Northeast wind 15 to 20 kt. Seas 6 to 8 ft. Wave

Detail: East 6 ft at 8 seconds, northeast 4 ft at 7 seconds,

north 3 ft at 11 seconds and northeast 2 ft at 10 seconds. 

.THURSDAY...Northeast wind 10 to 20 kt. Seas 6 to 7 ft. Wave

Detail: East 6 ft at 8 seconds, northeast 4 ft at 5 seconds and

north 2 ft at 10 seconds. 

.FRIDAY...Northeast wind 10 to 15 kt. Seas 4 to 6 ft. Wave

Detail: East 4 ft at 8 seconds, north 3 ft at 11 seconds and

northeast 3 ft at 4 seconds.  



$$