Flooding snarled traffic in the San Fernando and Jurupa valleys on Thursday as the season's first storm moved through Southern California.
Shortly after 9 p.m., miles of freeway traffic were starting to move on the Pomona (60) Freeway in Glen Avon where severe flooding forced the shutdown of three lanes (pictured below) near Country Village and Mission Boulevard.
Hours of snarled traffic were just one of the hassles that came in with the first fall storm of the season.
Rain, lightning and thunderstorms arrived in some parts of Southern California Thursday morning as a storm system building off the coast moved into the region.
Local news from across Southern California
By afternoon, a white coating of hail could be seen at foothill homes in La Canada Flintridge, where intersections appeared flooded in aerial video.
Rain was reported at Los Angeles International Airport, Long Beach and other areas beginning at 6 a.m. The system spread across a wide area later Thursday, and a strong thunderstorm was tracked in southern LA County.
Hail of up to 1/4-inch in diameter could be expected, along with heavy rainfall, according to the National Weather Service. "Frequent dangerous lightning" and localized flooding was expected in Downey, East LA, Lynwood and Montebello.
A flash flood warning was in effect until 10:30 p.m. for central San Bernardino County. Central LA County was under a similar warning earlier in the day.
An urban and small stream flood advisory was also issued for southern and central LA County, and southern and central Ventura County, with a warning that roads could flood during afternoon rush hour.
There was a slight increase in the number of traffic incidents reported during the morning drive, according to the California Highway Patrol. It was not immediately clear whether wet conditions factored into a crash involving a flatbed truck loaded with wooden pallets in downtown Los Angeles.
In Long Beach, a lightning strike caused a "power disruption" along the Blue Line Thursday morning. Service between the Willow and Del Amo stations was affected.
In Capistrano Beach, workers at an office captured this video Thursday of a tree falling on a sport utility vehicle. Isaac Somsel wrote in an e-mail to NBCLA.com that he heard the tree cracking before it toppled on to the SUV.
"I’ve seen people cut trees and have it fall on cars or houses, but I haven’t see it actually happen on its own," he wrote. "I figure the bushy tree collected too much water."
In Rancho Cucamonga, a home was struck by lightning. The home's electrical panel appeared to be badly damaged, and the Rancho Cucamonga Fire District said several electrical appliances in the home were "fried."
"They saw it flash through their kitchen, and it blinded her," said homeowner Lynn Gonzales, whose neighbor called her at work. "And then they just heard a big bomb."
"It was quick, but it was loud," said neighbor Neal Hughes.
The majority of rain and storm activity is expected later Thursday afternoon and into the evening. Snow levels might drop to 7,000 feet.
Temperatures will be in the mid-60s along the coast and high-60s in metro Los Angeles, inland Orange County and valley areas. Temperatures might dip in the 40s in mountain areas.
Expect warmer temperatures Friday. Above-normal temperatures are in Sunday's forecast.