12:38 p.m.: Mammoth Mountain announces extended ski season
Mammoth Mountain's ski slopes won't be closing Sunday after all. After an unseasonably cold spring storm dropped rain, hail and snow across Southern California, the resort said it would stay open at least another week.
Mammoth said via Twitter that it had received a foot of snow by Friday morning, and more scattered snow showers were expected into the afternoon.
— Brian Frank/KPCC
10:27 a.m.: Chilly spring storm brings rain, snow to California, Nevada
Scattered thundershowers doused Southern California on Friday as a chilly spring storm brought hail and lightning and dropped snow in the mountains, leading to a rare May snow day in some communities.
Commuters were urged to drive carefully following several overnight crashes on slick or flooded freeways in Los Angeles County.
The low-pressure system moved south into the region late Thursday after bringing gusty winds to the San Joaquin Valley and deserts. Several inches of snow fell high in the Sierra Nevada, where peaks that normally store a vast water supply have largely been free of snowpack after another dry year.
As was the case with several recent storms, this week's dousing was not expected to ease the state's extreme drought.
The National Weather Service said some areas might not see any rainfall, while thunderstorms could drop up to a half-inch in some spots and potentially trigger mud and debris flows in wildfire burn areas. As of dawn, about 0.2 inch of rain had fallen in downtown Los Angeles, while Whittier, to the southeast, saw more than half an inch.
Southern California mountains were getting snow at elevations as low as 5,000 feet, with mostly light accumulations. Officials opted to close schools in some communities along the San Bernardino Mountains because of the weather.
Daytime temperatures were expected to remain in the 60s.
Forecasters said the cold and unstable air mass might linger in the region into Saturday with widely varying effects, including the possibility of waterspouts in coastal waters.
The city of Glendora, on the foothills of the San Gabriel Mountains east of Los Angeles, raised its community alert to the second of four levels for residents below the scar of a January 2014 wildfire that burned five homes. The yellow alert requires residents to keep streets clear of vehicles and other obstructions. Rains late last year caused mud and debris flows from steep, bare slopes there.
Yosemite National Park received snow at high elevations Thursday, and the popular Tioga and Glacier Point roads were temporarily closed due to the conditions, the National Park Service said.
Glacier Point Road, leading to spectacular views, had reopened from its usual winter closure March 28 because of a lack of snow. That was the earliest opening in at least 20 years. Sometimes it remains closed until late May.
The Sierra Nevada crest above 7,000 feet was expected to see accumulations of 4 to 8 inches, with up to 12 inches in some areas, the National Weather Service's Reno office said.
Chains or snow tires were required on some highways.
"After a winter that was more like spring across the area, it looks like we are retrograding back a season over the next few days as a cold storm system impacts the area," the Las Vegas weather service office wrote.
Peaks near the Las Vegas region were likely to see a dusting of snow down to 5,000 feet.
— Christopher Weber/Associated Press
This story has been updated.