3:40pm – The National Weather Service in Portland has issued a Coastal Flood Advisory for minor tidal overflow, in effect from 9:00am to 3:00pm Sunday, for the South Washington Coast and North and Central Oregon Coast . A High Surf Advisory remains in effect until 7:00pm this evening for the South Washington Coast and North and Central Oregon Coast.
* Seas and Surf: seas will remain around 20 feet through this evening with periods around 16 seconds. Waves will slowly subside to around 17 feet late this evening. Swells of this magnitude will produce dangerous surf conditions.
* Tides: the observed high tide during the late morning on Sunday is expected to reach around 11 feet at Toke Point, Washington and between 10 feet and 11 feet for Astoria and South Beach (Newport), Oregon. With tidal anomalies of around 1.5 feet, this high tide will occur around 11:00am. These values are similar to the tides observed today.
* River Flows: coastal rivers flow are increasing due to abundant rainfall today. With expected additional rainfall tonight, the Willapa, Nehalem, Wilson, Siletz, Alsea and Siuslaw rivers are all expected to be at or near bankfull. Rivers may continue to run near flood flows during the midday Monday high tide. Current river levels and forecasts are available here.
* Impacts: affected locations will include low lying areas near bays and sloughs.. Highway 101, Highway 126 east of Florence and the lower reaches of coastal rivers. Historically, tides around 11 feet paired with near flood flows on local rivers have resulted in minor tidal overflow near Raymond, Tillamook, Nehalem, Waldport and Depoe Bay. The greatest impacts are likely between 9:00am and 2:00pm on Sunday.
Precautionary/Preparedness Actions: A High Surf Advisory means that high surf will affect beaches in the advisory area producing rip currents and localized beach erosion. A Coastal Flood Advisory indicates that onshore winds and tides will combine to generate flooding of low areas along the shore.