A powerful Pacific storm is expected to pound San Diego County with heavy rain and strong winds starting late Thursday.

The National Weather Service issued several advisories for the region, saying up to 3 inches of rainfall in coastal and valley areas, 3 to 5 inches in the mountains and up to an inch in the deserts would pose a strong threat of flash flooding and other road hazards through much of the weekend.

Rainfall forecast for Friday morning through Saturday. Chart created by National Weather Service.
Rainfall forecast for Friday morning through Saturday. Chart created by National Weather Service.

A flash flood watch for coastal, valley and mountain areas is scheduled from late Friday to Saturday afternoon.

“The greatest threat for flash flooding will be over mountains and over the recent burn areas where debris flows are possible,” an NWS advisory said.

The agency also said the low water crossings of the San Diego River in Mission Valley will be particularly susceptible to flooding. Motorists were strongly urged to not attempt to drive through flooded areas.

The weather service issued a high wind watch for mountain and desert areas from late tonight to Saturday evening, saying sustained south-to- southwest winds of 25 to 35 mph and gusts of up to 60 mph are likely.

A slightly less serious wind advisory for coastal and valley areas is scheduled from 4 a.m. Friday to 1 p.m. Saturday. According to the weather service, coastal and valley areas will likely see sustained south-to-southwest winds of 15 to 25 mph and gusts up to 35 mph.

“Gusty winds will make driving difficult, especially for motorists of high profile vehicles,” an NWS advisory said. “Watch for broken tree limbs and other debris.”

The storm is also likely to generate large, rough surf and strong rip currents along local beaches. The weather service scheduled a beach hazards statement from late tonight to Sunday afternoon, saying 8 to 12 foot surf with sets to 15 feet is possible by Saturday afternoon and evening.

Also, a gale watch for mariners off the coast of San Diego County will be in effect from late tonight to late Friday night. A gale watch is issued when the risk of gale-force winds of 34 to 47 knots has significantly increased.

In preparation for the storm, the San Diego Fire-Rescue Department announced it has a limited number of sandbags available to residents at fire stations in Ocean Beach, the Sports Arena area, Pacific Beach, Kearny Mesa, San Ysidro, Rancho Bernardo, Scripps Ranch, Tierrasanta, Rancho Penasquitos, Santaluz and Pacific Highlands. Bags also are available from lifeguard stations in Ocean Beach, Mission Beach, La Jolla Shores and Pacific Beach.

Residents can receive up to 10 bags at a time and are free to fill them with sand from area beaches.

— City News Service

Chris Jennewein is Editor & Publisher of Times of San Diego.