* WHAT. For the first Small Craft Advisory, seas 4 to 6 ft and south winds 15 to 20 kt with gusts up to 30 kt. For the Gale Warning, seas 6 to 8 ft at 8 seconds and south winds around 25 kt with gusts up to 35 kt expected. For the second Small Craft Advisory, seas 5 to 6 ft and south winds 15 to 20 kt with gusts up to 30 kt. * WHERE. In the Main Channel of the Columbia River Bar. * WHEN. Small Craft Advisory, from 8 AM this morning to 1 PM PDT this afternoon. Gale Warning, from 1 PM this afternoon to 6 PM PDT this evening. Small Craft Advisory, from 6 PM to 11 PM PDT this evening. * IMPACTS. Strong winds will cause hazardous seas which could capsize or damage vessels and reduce visibility. * ADDITIONAL DETAILS. First ebb current of 3.38 kt at 933 AM Friday with seas 5 to 6 ft. Second ebb current of 5.22 kt at 1021 PM Friday with seas 5 to 6 ft. Third ebb current of 2.61 kt at 1042 AM Saturday with seas to 6 ft. An unusually strong cold front for this time of year will bring a two to four hour period of marginal gale force wind gusts up to 35 kt Friday afternoon.