LOS ANGELES – Authorities and residents were bracing for flooding, thunderstorms, hail, tidal surges and even small tornadoes today, as the worst of seven days of storms was expected to sweep into Southern California.
Today’s storm was projected to be the most intense of the week, the result of a powerful cold storm from the Gulf of Alaska colliding with a river of subtropical moisture from the western Pacific Ocean.
“When you get the very cold air mixing in the with the very warm air, it can be quite volatile,” said Bill Patzert, climatologist at the Jet Propulsion Laboratory. Forecasters said the system could produce lightning and possibly waterspouts off shore and small tornadoes on land.
Today, Patzert said, is “definitely going to be the main event.”
Rainfall rates were expected to be as high as 0.75 to 1.5 inches an hour, which could cause flooding not only in foothills and mountains but also in low-lying areas, said Stuart Seto, a specialist with the National Weather Service in Oxnard.
“The ground is already permeated. There’s already a lot of moisture,” he said. “With the thunderstorms, the rain rates come faster.”
The weather warnings caused Los Angeles County officials to order the evacuation of 232 residences in La Crescenta and La Canada Flintridge, foothill suburbs under threat of flood waters draining from the fire-scarred slopes of the San Gabriel Mountains.
Los Angeles County Supervisor Michael D. Antonovich pleaded with residents to heed the order: “If you fail to comply, it could result in death.”
California Gov. Arnold Schwarzenegger has declared a state of emergency in Kern, Orange, Riverside, San Bernardino, San Luis Obispo and Tulare counties because of the storms.