The first storm system of fall socked Northern California Monday morning, snarling the Sacramento area's commute, causing localized flooding, downing power lines and dropping snow in the mountains.

The storm is expected to dump up to an inch of rain in the valley and 2 feet of snow in the mountains over the next two days, according to the National Weathr Service.

Rich Wetzel, an officer with he California Highway Patrol, said "dozens of collisions and spinouts" occurred in the area, most of them the result of rain-slicked roadways and high speeds. No major injuries were reported during the morning commute.

"Our last real storm was April 25, so oil and grime has built up on roads," he said. "With our first significant storm of the season, it causes hydroplaning issues. Drivers can avoid that by slowing down, keeping distance between the car in front of them, and not stopping aggressively."

In downtown Sacramento alone, there were six to eight collisions at the Interstate 5, and Highway 50 and 99 interchanges in the 5 a.m. hour, Wetzel said.

With gusts reaching 15 mph, drivers should also be aware of debris in the roadways, such as leaves and branches, authorities said.

Highway 244 between Madison and Watt avenues, at the onramp to southbound Capital City Freeway, was closed for about 90 minutes early Monday morning, as water pooled and California Department of Transportation officials worked to unclog six storm drains, Wetzel said.

"This is the first significant rainfall, and we're pretty sure this will put our fire season to an end," said Brooke Bingaman, meteorologist for the Sacramento office of the National Weather Service.

She said the storm could deliver about .75 to an inch of rain to the Sacramento area by the end of the day, bringing the total to almost normal to date.

Snow began falling at Sierra Nevada's Blue Canyon on Interstate 80 at 1 a.m. Monday, causing spinouts and chain control requirement in several areas.

Highway 20 just east of Nevada City has been shut down since 5:10 a.m., after a collision and vehicles entering the roadway without chains caused many vehicles to get stuck in snow there, Wetzel said. Snow plows are working to clear that area.

Chain controls are in place on eastbound Highway 50 from Twin Bridges to Meyers, and on some sections of eastbound Interstate 80, beginning at Drum Forebay.

Officials are holding traffic at westbound I-80 to clear a jack-knifed tractor-trailer rig, Wetzel said. No one was hurt in the incident, he said.

Sacramento Municipal Utilities District reported 14 outages affecting about 3,500 customers by this morning.

Bingaman said the rain will continue through Monday, becoming more intermittent in the afternoon and evening.

"The main storm system will linger over the West Coast and California through the middle of the week," she said. "We have a cold front coming through and showers will continue until early Thursday morning."

Drier, warmer weather is forecast by Friday through the weekend, she said.

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