FZMY50 PGUM 121843

CWFGUM



Coastal Waters Forecast for the Mariana Islands

National Weather Service Tiyan GU

443 AM ChST Sat Dec 13 2025



Marianas Waters out to 40 nautical miles



PMZ150-130830-

443 AM ChST Sat Dec 13 2025



.Synopsis for Marianas Waters...

Moderate to fresh trade winds are expected through Wednesday. The

older shear line is moving off to the east, while a new one is

moving south through the far northern CNMI and is expected to 

move over or just north of Saipan by tonight. This is expected to

elevate the winds near Saipan and Tinian to fresh to strong. 

Overall, combined seas of 6 to 7 feet are expected to increase by 

a foot or two for Guam and Rota and seas near Tinian and Saipan 

could rise to near 10 feet over the weekend and may warrant a 

Small Craft Advisory. Around the middle of next week another north

swell pulse may push through the region.



$$



PMZ151-152-130830-

Guam Coastal Waters-Rota Coastal Waters-

443 AM ChST Sat Dec 13 2025



.TODAY...East wind 15 kt. Seas 6 to 7 ft. Wave Detail: Northeast

5 ft at 9 seconds and east 3 ft at 5 seconds.

.TONIGHT...East wind 15 to 20 kt. Seas 6 to 8 ft. Wave Detail:

East 5 ft at 6 seconds and northeast 5 ft at 9 seconds.

.SUNDAY...East wind 20 kt. Seas 7 to 9 ft. Wave Detail: Northeast

6 ft at 9 seconds and east 5 ft at 6 seconds.

.SUNDAY NIGHT...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave

Detail: Northeast 7 ft at 9 seconds and east 4 ft at 6 seconds.

.MONDAY THROUGH TUESDAY...East wind 15 to 20 kt. Seas 6 to 8 ft.

Wave Detail: Northeast 7 ft at 9 seconds, east 4 ft at 6 seconds

and north 3 ft at 11 seconds.

.WEDNESDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail:

North 7 ft at 10 seconds and east 4 ft at 6 seconds.



$$



PMZ153-154-130830-

Tinian Coastal Waters-Saipan Coastal Waters-

443 AM ChST Sat Dec 13 2025



.TODAY...East wind 15 to 20 kt. Seas 6 to 8 ft. Wave Detail:

Northeast 6 ft at 9 seconds and east 4 ft at 6 seconds.

.TONIGHT...East wind 20 to 25 kt. Seas 7 to 9 ft. Wave Detail:

East 6 ft at 7 seconds and northeast 5 ft at 8 seconds.

.SUNDAY...East wind 20 kt with gusts to 30 kt. Seas 7 to 9 ft.

Wave Detail: Northeast 6 ft at 9 seconds and east 5 ft at

7 seconds.

.SUNDAY NIGHT...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave

Detail: Northeast 8 ft at 9 seconds and east 4 ft at 6 seconds.

.MONDAY...East wind 15 kt. Seas 7 to 9 ft. Wave Detail: Northeast

8 ft at 9 seconds, east 3 ft at 5 seconds and north 2 ft at

11 seconds.

.TUESDAY...East wind 15 to 20 kt. Seas 6 to 8 ft. Wave Detail:

Northeast 6 ft at 9 seconds, east 4 ft at 6 seconds and north 3 ft

at 11 seconds.

.WEDNESDAY...East wind 15 to 20 kt. Seas 7 to 9 ft. Wave Detail:

Northeast 7 ft at 9 seconds, east 4 ft at 6 seconds and north 3 ft

at 10 seconds.



$$