FZMY50 PGUM 190637

CWFGUM



Coastal Waters Forecast for the Mariana Islands

National Weather Service Tiyan GU

437 PM ChST Thu Mar 19 2026



Marianas Waters out to 40 nautical miles



PMZ150-192200-

437 PM ChST Thu Mar 19 2026



.Synopsis for Marianas Waters...

Elevated long-period north to northeast swells from distant low 

pressure systems will continue to produce hazardous seas of 8 to 

10 feet across the Marianas coastal waters through at least 

Friday afternoon. Overall, long-period northerly swells gradually

subside, but building east to northeast swell will keep seas 

elevated, potentially remaining at hazardous levels of 8 to 10 

feet at Tinian and Saipan through the weekend. Moderate to fresh 

winds out of the northeast are expected through early next week.



$$



PMZ151>154-192200-

MARIANAS COASTAL WATERS-

437 PM ChST Thu Mar 19 2026



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



.TONIGHT...Northeast wind 15 to 20 kt. Seas 8 to 10 ft. Wave

Detail: North 8 ft at 12 seconds, northeast 4 ft at 6 seconds and

northeast 4 ft at 14 seconds. 

.FRIDAY...Northeast wind 15 to 20 kt. Seas 8 to 10 ft. Wave

Detail: North 8 ft at 11 seconds, northeast 4 ft at 5 seconds and

northeast 4 ft at 13 seconds. 

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

Detail: Northeast 5 ft at 11 seconds, north 5 ft at 13 seconds,

northeast 4 ft at 5 seconds and northeast 3 ft at 14 seconds. 

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

Detail: Northeast 5 ft at 11 seconds, north 5 ft at 14 seconds,

northeast 4 ft at 5 seconds and northeast 3 ft at 14 seconds. 

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

Wave Detail: Northeast 6 ft at 11 seconds, northeast 4 ft at

6 seconds, north 4 ft at 13 seconds and northeast 3 ft at

14 seconds. 

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

East 7 ft at 9 seconds, northeast 4 ft at 7 seconds, north 3 ft

at 12 seconds and northeast 3 ft at 13 seconds. 

.MONDAY...Northeast wind 15 to 20 kt. Seas 8 to 10 ft. Wave

Detail: East 9 ft at 9 seconds, northeast 4 ft at 6 seconds and

northeast 3 ft at 12 seconds. A chance of showers. 

.TUESDAY...East wind 10 to 15 kt. Seas 7 to 9 ft. Wave Detail:

East 7 ft at 9 seconds, east 3 ft at 5 seconds, north 4 ft at

12 seconds and northeast 2 ft at 11 seconds. A chance of showers.

 



$$