A storm soaking California on Wednesday could trigger mudslides in wildfire burn areas where thousands of residents are under evacuation orders, authorities warned.
The storm also brought thunderstorms and a dramatic lightning display.
Nearly 1,500 pulses of lightning were recorded off the coast in one five-minute stretch alone, 231 over Santa Barbara County and 40 in Los Angeles County, shortly after 8 p.m, the National Weather Service told the Los Angeles Times.
In Santa Clarita Valley, lightning and thunder lasted more than an hour.
The weather service warned residents to stay away from tall or metal objects, and avoid being in water, or out in the open when watching the lightning storms.
The Santa Barbara County Sheriff's Office ordered 3,000 residents to evacuate hillside neighborhoods scarred by fires — including parts of Montecito hit by a disastrous debris flow just over a year ago. Officials didn't say how many people heeded the order.
Many customers pumping gas at Montecito's Village Service Station on Tuesday said they're not leaving, according to Ray Dunham, who works there.
"Nobody's going into panic mode," he said. "They think the threat is way over-exaggerated."
Sheriff Bill Brown told a news conference earlier this week that the system is expected to be more intense than the last several storms. A map published by the county Office of Emergency Management indicates that much of Montecito is at risk.
"We do not take these evacuation orders lightly, and while we do know this is very inconvenient, if you are in an evacuation area, please know there is a high risk to life and property," Brown said.
A January 2018 debris flow from the Thomas fire scar destroyed or damaged hundreds of Montecito structures, killed 21 people and left two others missing.
The weather service issued a flash-flood watch through Wednesday for all burn areas in Santa Barbara, Ventura and Los Angeles counties. However, the storm is expected to weaken slightly as it moves south toward greater Los Angeles, forecasters said.
Ventura County residents prepared for mudslides and debris flows in the fire-scarred areas throughout Tuesday, using sandbags to protect their homes from damage.
There were voluntary evacuation orders in place for some parts of the county.
To the north, heavy snowfall and high winds are predicted for the Sierra Nevada, where a series of blizzards has dumped mountains of snow. Motorists are warned that low visibility could impede travel on mountain passes.
The wettest winter in years has nearly eliminated drought conditions in the state. While frequently disrupting travel, the storms contributed a big part of the state's water supply — the Sierra snowpack that melts and runs off into reservoirs during spring and summer.
The California Department of Water Resources reported last month that the Sierra snowpack was 153 percent of average to date.
KTLA's Carlos Saucedo contributed to this report.