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LOS ANGELES (CBS/AP) — The first day of spring arrived with a bang in Southern California, bringing heavy snow to the mountains and illuminating the sky with flashes of lightning from Santa Barbara to downtown Los Angeles.

Heavy rain, wind and snow prompted the closure of a long stretch of the Golden State (5) Freeway through the Grapevine, a CHP officer said.

Debris Basins Above Station Fire Burn Area Holding Up

The closure, which started just north of Parker Road, was ordered at 7:09 p.m., said CHP Officer Krystal Carter.

No weather-related collisions were reported in the area, but weather precautions were being taken, Carter said.

Alternate routes include the Antelope Valley (14) Freeway, which was experiencing extreme congestion.

The storm prompted the closure of the Sepulveda Dam and Recreation Area, as well as several surrounding streets, along with the Sepulveda Tunnel near LAX, police said.

Burbank Boulevard east of Balboa and at the San Diego (405) Freeway was closed due to water on the pavement, said Rudolph Valadez of the Los Angeles Police Department.

Also in the West Valley area, Vanowen Street was closed between Woodley Avenue and Hayvenhurst Avenue, Oxnard Street was closed at Donna Street and Balboa Boulevard was closed between Victory and Burbank Boulevards, said Officer Cleon Joseph.

“These street closures are subject to the amount of rainfall,” Joseph said. “They will remain in place until the storm subsides.”

The Sepulveda Tunnel near Los Angeles International Airport is also closed due to flooding, according to police.

Alternate routes to LAX include Aviation Boulevard east of Sepulveda or Pershing Boulevard west of Sepulveda.

The California Highway Patrol reported several vehicles stuck in moving water as well as other rock and mud flows affecting the area.

Doppler radar indicated that the heaviest rainfall was occurring across the Santa Clarita Valley, as well as the nearby mountains.

A weather spotter reported steady rain across the Antelope Valley over the last few hours.

With increasing rain across the mountains, there could be widespread flooding across the Antelope Valley, especially near Big Rock and Littlerock Creeks, according to the Weather Service.

Hourly rainfall rates across the county ranged from a quarter-inch an hour in the eastern part of the county to a half- to two-thirds of an inch an hour in the west and central parts of the county.

Lightning briefly lit up the downtown sky shortly after the start of Sunday’s Los Angeles Marathon, but it didn’t deter the hundreds of runners who plowed on through the rain.

By late Sunday morning rainfall totals across the region ranged from about a half inch to up to 2 inches. Another half inch or more was expected before the storm leaves Monday.

Some of the biggest problems were being reported in Woodland Hills, where heavy rains and high winds caused mudslides, prompting the evacuation of about 30 people in 12 homes near 4855 N. Regalo Road, where debris and mud were approaching a retaining wall, said Diana Igawa of the Los Angeles Fire Department.

No one was injured, and those displaced were taken to a fire station for shelter, Igawa said.

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