Heavy Rain and Risk of Mudslides Forecast

If you’re at all inclined to trust the weather forecast, don’t forget your umbrella today.

Meteorologists expect the season’s biggest storm yet to dump two to four inches of rain in coastal areas and inland valleys and up to 10 inches in the foothills and mountains.

The National Weather Service said the fast-moving cold front from the Gulf of Alaska could dump up to half an inch an hour in lower elevations and up to an inch an hour in the mountains.

The heaviest rainfall is predicted for the south- and southwest-facing slopes in the Los Angeles, Ventura and Santa Barbara county mountains.

“This storm is big and strong enough that we’re getting everything thrown at us but the kitchen sink,” said Bill Hoffer, a spokesman for the National Weather Service. “It’s unusual; we don’t get these strong storms every single year.”

Given the storm’s unusual intensity, the National Weather Service issued a flash flood watch, with possible mud and debris flows over the next two days for much of Southern California. It cautioned that coastal areas may experience high winds, rough seas and lightning.

Since July 1, the region has received just half of its normal rainfall, logging 5.33 inches. The area is also considerably behind the typical precipitation received for the first two months of the year, with 2.44 inches falling since Jan. 1, compared with 6.75 inches in a normal period.