239
FZMY50 PGUM 251148 AAA
CWFGUM

Coastal Waters Forecast for the Mariana Islands...UPDATED
National Weather Service Tiyan GU
Issued by National Weather Service Honolulu HI
948 PM ChST Wed Jun 25 2025

Marianas Waters out to 40 nautical miles

PMZ150-252100-
948 PM ChST Wed Jun 25 2025

.Synopsis for Marianas Waters...Gentle to moderate east to
southeast winds for Guam and Rota, and moderate to fresh winds
for Saipan and Tinian will continue through Thursday before
diminishing and shifting to south or southwest by Friday. Passing
showers will bring wind gusts of 25 to 30 kt to Saipan and Tinian
tonight thus a Small Craft Advisory has been issued. A tropical
disturbance is expected to develop and move into the Marianas the
next few days and result in heavier showers redeveloping across
the region between Thursday and Friday. Combined seas of 4 to 6
feet will build a foot for Guam and Rota waters by Friday. Across
Saipan and Tinian, seas will be higher, building to between 6 and
8 ft Thursday, then falling about a foot by Sunday.

$$

PMZ151-152-252100-
Guam Coastal Waters-Rota Coastal Waters-
948 PM ChST Wed Jun 25 2025

Updated for drier conditions overnight.

.REST OF TONIGHT...Southeast wind 10 to 15 kt with occasional
gusts to 25 kt. Seas 4 to 6 ft. Wave Detail: East 4 ft at 8
seconds and southeast 3 ft at 4 seconds. Scattered showers with
isolated thunderstorms developing toward dawn.
.THURSDAY...South wind 10 to 15 kt. Gust to 25 kt near showers.
Seas 4 to 6 ft. Wave Detail: East 5 ft at 8 seconds and south 3 ft
at 4 seconds. Numerous showers with isolated thunderstorms.
Locally heavy downpours possible.
.THURSDAY NIGHT...South wind 10 to 15 kt. Gusts to 25 kt near
showers. Seas 4 to 6 ft. Wave Detail: East 5 ft at 8 seconds and
south 3 ft at 4 seconds. Numerous showers with isolated
thunderstorms. Locally heavy downpours possible.
.FRIDAY...South wind 10 kt. Gusts to 20 kt near showers. Seas 5
to 7 ft. Wave Detail: East 4 ft at 8 seconds and southwest 3 ft
at 4 seconds. Numerous showers with isolated thunderstorms.
Locally heavy downpours possible.
.FRIDAY NIGHT...South wind 10 kt. Gusts to 20 kt near showers.
Seas 5 to 7 ft. Wave Detail: East 4 ft at 8 seconds and southwest
4 ft at 5 seconds. Numerous heavy showers with isolated
thunderstorms.
.SATURDAY THROUGH SUNDAY...South wind 10 to 15 kt. Seas 5 to
7 ft. Wave Detail: Southwest 5 ft at 6 seconds and east 4 ft at
8 seconds. Showers likely with a slight chance of thunderstorms.
Locally heavy downpours possible.
.MONDAY...South wind 5 to 10 kt. Seas 5 to 7 ft. Southwest 5 ft
at 6 seconds and east 4 ft at 8 seconds. A chance of showers with
a slight chance of thunderstorms.

$$

PMZ153-154-252100-
Tinian Coastal Waters-Saipan Coastal Waters-
948 PM ChST Wed Jun 25 2025

Updated for drier conditions overnight.

...SMALL CRAFT ADVISORY IN EFFECT THROUGH EARLY THURSDAY
MORNING...

.REST OF TONIGHT...Southeast wind 15 to 20 kt with frequent gusts
to 30 kt. Seas around 7 ft. Wave Detail: East 5 ft at 8 seconds
and southeast 5 ft at 4 seconds. Scattered showers with isolated
thunderstorms toward dawn.
.THURSDAY...Southeast wind 15 kt. Gust to 25 kt near showers. Seas
around 7 ft. Wave Detail: East 5 ft at 8 seconds and southeast 3
ft at 4 seconds. Numerous showers with isolated thunderstorms.
Locally heavy downpours possible.
.THURSDAY NIGHT...Southeast wind 10 to 15 kt. Gusts to 25 kt near
showers. Seas around 7 ft. Wave Detail: East 5 ft at 8 seconds
and southeast 3 ft at 4 seconds. Scattered showers with isolated
thunderstorms. Locally heavy downpours possible.
.FRIDAY...Southeast wind 10 to 15 kt. Gusts to 25 kt near showers.
Seas around 8 ft. Wave Detail: East 6 ft at 8 seconds and
southeast 3 ft at 4 seconds. Scattered showers with isolated
thunderstorms. Locally heavy downpours possible
.FRIDAY NIGHT...East wind 10 to 15 kt. Gusts to 25 kt near
showers. Seas 6 to 8 ft. Wave Detail: East 6 ft at 8 seconds and
south 3 ft at 4 seconds. Scattered showers with isolated
thunderstorms. Locally heavy downpours possible.
.SATURDAY...Southeast wind 5 to 15 kt. Seas 6 to 8 ft. Wave
Detail: East 6 ft at 8 seconds and south 3 ft at 4 seconds. A
chance of showers with a slight chance of thunderstorms. Locally
heavy downpours possible.
.SUNDAY THROUGH MONDAY...South wind 5 to 15 kt. Seas 5 to 7 ft.
Wave Detail: East to southeast 6 ft at 8 seconds and south 4 ft
at 4 seconds. A chance of showers with a slight chance of
thunderstorms. Locally heavy downpours possible through Sunday
night.

$$