HIGH SURF WARNING FOR NORTH AND WEST FACING SHORES OF BIG ISLAND .An extremely large, long period northwest swell will build late tonight and Saturday then peak Saturday evening. Very large surf well above the warning level is expected from early Saturday through the weekend, and potentially into Monday for the smaller islands. North and west facing shores on the Big Island should expect warning level surf by Saturday afternoon. ...HIGH SURF WARNING IN EFFECT UNTIL 6 PM HST SUNDAY... The National Weather Service in Honolulu has issued a High Surf Warning, which is in effect until 6 PM HST Sunday. * SURF...building to 20 to 30 feet for north facing shores of the Big Island. * TIMING...surf will build to warning levels Saturday afternoon, peak late Saturday night, and hold at warning level through the weekend. * IMPACTS...Very High...Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways. Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling.