Timing

April 13, 2026 10:58 AM UTC+10
April 13, 2026 10:58 AM UTC+10
April 13, 2026 10:58 AM UTC+10
April 14, 2026 1:00 AM UTC+10

NWS Headline

HIGH SURF WARNING REMAINS IN EFFECT UNTIL 6 PM CHST THURSDAY... ...COASTAL FLOOD WATCH REMAINS IN EFFECT THROUGH WEDNESDAY AFTERNOON

Description

* WHAT...For the High Surf Warning, dangerously large breaking

waves of 10 to 15 feet for Guam and 15 to 25 ft for Rota, Tinian

and Saipan. For the Coastal Flood Watch, significant coastal

flooding 1 to 3 ft for Guam, and 4 to 8 ft for Rota, Tinian, and

Saipan are possible.


* WHERE...North, east and south facing reefs of the Marianas. For

the Coastal Flood Watch, north, east, and south facing

shorelines.


* WHEN...For the High Surf Warning, until 6 PM ChST Thursday. For

the Coastal Flood Watch, through Wednesday afternoon.


* IMPACTS...Numerous roads may be closed. Low lying property

including homes, businesses, and some critical infrastructure

may be inundated. Some shoreline erosion may occur. Breaking

waves can sweep people off jetties and docks, and into dangerous

seas. Life-threatening swimming conditions and significant beach

erosion can be expected.


* ADDITIONAL DETAILS...As STY Sinlaku moves towards the Marianas

swell and surf are expected to rapidly build. This will generate

dangerous surf and increase the risk for coastal inundation,

especially as STY Sinlaku begins to move through the Marianas on

Tuesday.

Instructions

Everyone should remain out of the water due to life-threatening

surf conditions. Stay off of jetties, piers, and other waterside

infrastructure.

Affected Areas

Guam; Rota; Tinian; Saipan

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