Forecasters say the moisture will do virtually nothing to tamp down the threat of wildfires in a region starving for rain.

Finally, weather conditions in San Diego County are expected to shift late this week as an upper low-pressure system moves in from the Pacific Thursday afternoon into early Friday, according to the National Weather Service.

San Diego Gas & Electric more than doubled the number of customers whose power has been shut off Tuesday as Santa Ana winds began booming inland and spreading to coastal area. Through 1:45 p.m., 5,620 customers had lost power,