LOS ANGELES – Badly needed rains for a state dried out by drought moved from northern to Southern California with much more expected as the week goes on, but the showers brought their own potential problems.
The storm dropped about an inch of rain on parts of the San Francisco Bay Area and by late Wednesday night had started sprinkling on Los Angeles.
The storm — and the far larger one expected to arrive Friday — brought worries and recommended evacuations in some areas in the suburbs of Glendora and Azusa about 25 miles northeast of Los Angeles, because they sit at the foot of the steep San Gabriel Mountains where a wildfire last month stripped nearly 2,000 acres where water could now pose a danger.
"Residents located near burn areas should be alert for the potential of mud and debris flows Friday through Saturday," forecasters said.
Glendora on Wednesday raised its flooding protocol alert level for a second time, urging that residents near the burn area voluntarily evacuate or prepare essentials such as medications and important papers in case a mandatory evacuation order is given.
The city provided thousands of sandbags to residents who streamed into a city yard to fill the bags and drive them away.
Sandbags were also being provided in other foothill communities along mountain ranges east and west of Los Angeles, where other fires have burned in recent years, including the area of the May 2013 Springs Fire in the Santa Monica Mountains.
The National Weather Service said light-to-moderate rain from the first storm was expected through midday Thursday.
The weather service said the second storm will be stronger and move across Southern California from late Thursday through late Saturday, reaching Los Angeles County early Friday morning with rainfall amounts ranging from 3-6 inches in the foothills, and up to 8 inches in localized areas.
That second storm will bring by far the heaviest of rain to Southern California, Ken Clark, an Accuweather meteorologist, said in an email.
"In fact as much, or more rain, may fall in parts of Southern California than fall, let's say, around the Bay Area when all is said and done," Clark wrote.
State water officials plan Thursday to survey the anemic mountain snow pack, and will likely find that California's precipitation is badly lagging what's needed to quench the region's thirst after 2013 ended as the state's driest year on record.
A so-called Pineapple Express storm brought rain and snow to California earlier this month, and when it departed, the Sierra Nevada snowpack had grown but was still only 29 percent of normal.
Rain fell throughout the day Wednesday in San Francisco, and gave a midday pounding to the Santa Cruz Mountains south of the Bay Area.
The showers caused the cancellation of more than 100 flights at San Francisco International Airport.