Storm Brings Warning About Mudslides in Burned Areas

Fire-ravaged areas of South County were bracing Monday night for a fast-moving storm system that brought rain throughout the county just after 7:30 p.m., four hours after the National Weather Service issued a flash flood watch.

The service also issued an urban and small stream flood advisory for the Laguna Beach area.

Shortly after the rain began, police in Costa Mesa had to block off the intersection of 19th Street and Anaheim Avenue, a usual flooding location. Several minor collisions occurred at Westminster intersections, which police attributed to rain-slick roads.

“We’re expecting a quarter of an inch to half an inch in the coastal areas” through this morning, with decreasing clouds through the afternoon, said Curtis A. Brack, a meteorologist with WeatherData, which provides forecasts for the Times. The rain was expected to stop this morning.

“These showers are associated with a strong but fast-moving upper-level disturbance which will move over the forecast area tonight,” according to a National Weather Service statement.

“The California Office of Emergency Services, in cooperation with the National Weather Service, advises that an inch or more of rain in a six-hour period may cause mud and debris flows in recently burned areas,” the statement said. “Large areas of loose, unstable ash and topsoil may wash or flow during heavy rainfall.”