USGS-landslides.20060720T161849 cannon@usgs.gov 20060720T161849.000Z Actual Alert Public en-US Geo Flash Flood and Debris Flow Watch for Recently Burned Areas in Southern California Future Unknown Possible Joseph Gartner Flash Flood and Debris Flow Watch for Recently Burned Areas in Southern California At 3:57 am, Thursday, July 20, 2006 the National Weather Service for Los Angeles and Oxnard, California issued a flash flood watch for the mountains of Los Angeles, Ventura and Santa Barbara Counties. An influx of deep subtropical moisture into Southwestern California will cause an increasing chance of showers and thunderstorms today. The chance of thunderstorms will be greatest this afternoon and evening across the Cuyama Valley, Antelope Valley and the Santa Barbara Mountains, Ventura and Los Angeles Counties excluding the Santa Monica Mountains. The mid and upper level winds which will be steering any thunderstorms will be very weak. Therefore thunderstorms and heavy showers could linger over any particular area for a while, producing heavy rainfall and a threat of flash flooding and debris flows. The Perkins Burn Area is a recent fire that will be particularly vulnerable to flash flooding with debris flows should thunderstorms develop over that region this afternoon through this evening. Residents or persons with interests near and especially downstream of the burned areas should monitor later forecasts and be prepared to take protective action should flash flood warnings be issued. For more information on what to do if you live near a recently burned area, and more information on post-fire debris flow flows: http://landslides.usgs.gov/research/wildfire. Campers, hikers and others spending time in the mountains should avoid narrow canyon areas that could flood rapidly in response to even distant thunderstorms. Keep escape routes in mind and be prepared to climb to higher ground with little or no notice. jegartner@usgs.gov Southern California, including the Cuyama Valley, Antelope Valley and the Santa Barbara Mountains, Ventura and Los Angeles Counties excluding the Santa Monica Mountains