Coastal Flood Watch

* WHAT...For the High Surf Advisory, large breaking waves of 25 to 35 feet in the surf zone. For the Coastal Flood Watch, significant coastal flooding.

* WHERE...Guam, Rota, Tinian and Saipan.

* WHEN...For the High Surf Advisory, until 4 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 will be inundated. Significant shoreline erosion will occur. Waters will be deadly.

* ADDITIONAL DETAILS...Surf levels are building to hazardous levels along north and east facing reefs as Super Typhoon Bavi approaches the Marianas from the east, and will rapidly become dangerous across north, east, and south facing reefs into this evening as tropical storm force conditions develop, spreading to west facing reefs soon after. Surf will potentially build to 35 feet Monday morning near Rota and 30 feet elsewhere as Bavi makes passage through the islands as a Category 5 Super Typhoon. Coastal inundation will become likely beginning late this afternoon, potentially sooner if the system begins to move faster. During the passage of Bavi, coastal inundation could approach 12 feet, especially near the storm center due to the dome effect. Once Bavi exits to the west-northwest by Tuesday, coastal inundation and erosion is likely to increase along west facing shores while easing elsewhere.