California is preparing for another atmospheric river

Twin storms were expected to hit California this week, the second likely to provide the last of nearly a dozen atmospheric rivers to flood the state in recent months.

The National Weather Service predicts periods of heavy rain and heavy snowfall for the Sierra Nevada with wind gusts reaching 50 mph over the next few days.

“After a quiet Saturday, the active weather is expected to spread across much of the West,” the weather service warned.

The first storm had already begun bringing moisture from the Pacific into California on Sunday and is expected to spread rapidly north into the Pacific Northwest.”

AccuWeather meteorologists warn that twin storms could produce “significant” rainfall in northern California before spreading to the southern part of the state.

“Any vigorous downpours could further exacerbate river flooding issues in Northern California,” AccuWeather meteorologist La Troy Thornton warned.

The second storm, which will arrive on Tuesday, will likely include the characteristics of an atmospheric river — a long, fluid region of the atmosphere that carries water vapor across the sky, AccuWeather said. This storm will bring even more rain and mountain snow on Wednesday, AccuWeather said.

THUNDERSTORMS SWEEP CENTRAL USA:Possible blizzard conditions

Developments:

►The second storm is expected to focus on Southern California, with the wide availability of moisture causing rainfall amounts to skyrocket, AccuWeather said.

► Heavy rain is expected to affect the Los Angeles area on Tuesday and widespread flooding is possible. As of March 18, downtown Los Angeles had received 24.06 inches of rain since November, more than double its normal total for the date.

Whiteout in Michigan: Dozens of cars crash on the freeway

Lake-effect snow showers will continue mostly downwind of the lower Great Lakes early Sunday, the weather service said. In Michigan, Interstate 96 near Portland was fully open Sunday, hours after dozens of vehicles were involved in a pileup in whiteout conditions. Michigan State Police officials said they closed eastbound and westbound I-96 just after 5 p.m. Saturday after the crash on the eastbound lanes. There were whiteout conditions ahead of the pile-up of up to 100 cars, but the sun was up and the sky had cleared by the time they released an image showing the wreckage. Injuries were reported, but none were serious, police said.

Video obtained by the State Journal showed that numerous vehicles collided with the cable barrier separating the eastbound and westbound lanes.

Conditions deteriorated rapidly and visibility deteriorated just before the crash. Some drivers hit guardrails, while others were unable to stop and crashed into cars in front of them.

Floodwaters trap hikers in the Grand Canyon

Floodwaters are beginning to recede in the Havasupai Tribe area near Grand Canyon National Park, where tourists were trapped overnight over the weekend, the tribe said on its Facebook page. Tribal guides led hikers around the creek waters to the village via a side trail. The tribe reported Friday that flooding washed away a bridge leading to the campground and an unknown number of campers were evacuated on Saturday, some by helicopter. The area is deep in a gorge, accessible only by foot, helicopter, horseback or mule.

“No cameras, no photos as you are guided through areas usually closed to tourists,” the Facebook post read. “These are sacred sites, so please be respectful and follow directions. We are doing our best to make reasonable accommodations.”

Contribute: The Associated Press