* WHAT...Significant coastal flooding. * WHERE...In Louisiana, Lower St. Bernard, Southeast St. Tammany, Eastern Orleans and Lower Plaquemines Parishes. In Mississippi, Southern Hancock, Southern Harrison and Southern Jackson Counties. * WHEN...Until 4 AM CDT Thursday. * IMPACTS...Numerous roads may be closed. Low lying property including homes, businesses, and some critical infrastructure will be inundated. Some shoreline erosion will occur. * ADDITIONAL DETAILS...Inundation is expected to be 2-4 feet along the coast in the warned area. Take the necessary actions to protect flood-prone property. If travel is required, do not drive around barricades or through water of unknown depth.