FZMY50 PGUM 201831

CWFGUM



Coastal Waters Forecast for the Mariana Islands

National Weather Service Tiyan GU

431 AM ChST Sun Jun 21 2026



Marianas Waters out to 40 nautical miles



PMZ150-210915-

431 AM ChST Sun Jun 21 2026



.Synopsis for Marianas Waters...

Light to gentle winds and combined seas of 3 to 5 feet will

continue through Wednesday, then seas could increase a little.

A secondary southwest swell from distant Tropical Storm Mekkhala 

will encompass the region starting Monday before shifting to more 

westerly a day or two later. A new tropical disturbance will

likely affect the Marianas starting Monday night.



$$



PMZ151>154-210915-

MARIANAS COASTAL WATERS-

431 AM ChST Sun Jun 21 2026



.TODAY...Southeast wind 5 to 10 kt. Seas around 3 ft. Wave

Detail: East 3 ft at 8 seconds and southeast 2 ft at 10 seconds.

Scattered showers.

.TONIGHT...Southeast wind 5 kt. Seas around 3 ft. Wave Detail:

East 3 ft at 8 seconds and southeast 2 ft at 10 seconds.

.MONDAY...Southeast wind 5 kt. Seas 3 to 4 ft. Wave Detail:

Southeast 3 ft at 8 seconds and southwest 2 ft at 10 seconds.

.MONDAY NIGHT...Southeast wind 5 kt. Seas 3 to 4 ft. Wave Detail:

Southeast 4 ft at 8 seconds and southwest 2 ft at 10 seconds.

Isolated thunderstorms.

.TUESDAY AND WEDNESDAY...Northeast wind 10 kt. Seas 3 to 5 ft. 

Wave Detail: Southeast 3 ft at 8 seconds, east 2 ft at 4 seconds 

and southwest 2 ft at 10 seconds. Isolated thunderstorms.

.THURSDAY...East wind 5 to 10 kt. Seas 4 to 6 ft. Wave Detail:

East 4 ft at 8 seconds, east 2 ft at 4 seconds and west 2 ft at

10 seconds. A chance of showers with a slight chance of

thunderstorms.  



$$