* WHAT...For the Coastal Flood Warning, significant coastal flooding expected. For the High Surf Warning, dangerously large breaking waves up to 35 feet for Guam, 20 to 25 feet for Rota, and 15 to 20 feet for Tinian and Saipan. * WHERE...Guam, Rota, Tinian and Saipan. * WHEN...From 5 PM this afternoon to 4 AM ChST Monday. * IMPACTS...Numerous roads may be closed. Low-lying property including homes, businesses, and some critical infrastructure will be inundated. Shoreline erosion will occur. Breaking waves can sweep people off their feet, and into dangerous seas. Life- threatening swimming conditions and significant beach erosion can be expected. Coastal inundation of 5 to 7 feet for Guam, 2 to 4 feet for Rota and 1 to 3 feet for Tinian and Saipan is possible along with coastal flooding and beach erosion. * ADDITIONAL DETAILS...Surf is expected to rise rapidly to dangerous levels tonight. Coastal impacts to the western coast of Guam and Rota are highly dependent on the final track of Champi; passage south of Guam would be reduced impacts whereas passage over Guam would result in larger coastal inundation. Everyone should remain out of the water due to life-threatening surf conditions. Stay well away from the coast.