LOS ANGELES >> Heavy snow and rain pounded California and other parts of the West on Friday in the nation’s latest winter storm, while tens of thousands of people in Michigan suffered in freezing temperatures days after one of the worst ice storms in decades caused widespread power outages.

Days of winter storms blacked out nearly 1 million homes and businesses from coast to coast, closed major roads, caused pileups on highways and snarled air travel. More than 460 flights were canceled and more than 7,400 were delayed Friday across the U.S., according to FlightAware.com.

In California, the National Weather Service warned of cold, snowy and rainy weather lasting through Saturday and issued flash flood warnings through 10 p.m. Friday for Los Angeles, its suburbs and a portion of Ventura County, a region that is home to about 6 million people.

Cellphones buzzed Friday afternoon with an emergency alert that warned: “This is a dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding.”

Some places in the flash flood warning zone could see up to 10 inches (23 centimeters) of rain, the weather service said.

Authorities warned that heavy rainfall could cause debris flow in some areas burned by wildfires in recent years. Evacuation warnings were issued for some areas, with residents urged to be ready to flee at a moment’s notice.

Blizzard warnings were posted in the Sierra Nevada and Southern California mountain ranges, where as much as 5 feet (1.5 meters) of snow was expected. Temperatures could drop far below normal in the region, posing a special risk to homeless people.

“Simply put, this will be a historic event for the amount of snow over the higher peaks and lower elevation snow,” according to the regional weather office.

Interstate 5, the West Coast’s major north-south highway, was closed south of the Oregon border as snow fell to the floor of the Sacramento Valley. A high mountain pass north of Los Angeles also was closed for hours before finally reopening late Friday, although traffic was creeping along with a police escort.

In Michigan, hundreds of thousands of people remained without power Friday after a storm earlier this week coated power lines, utility poles and branches with ice as thick as three-quarters of an inch (1.9 centimeters). Gov. Gretchen Whitmer called Friday for more accountability on restoration efforts by the state’s two largest utilities.

Annemarie Rogers had been without power for a day and a half in Grosse Pointe Farms, Michigan. She sent two kids to stay with relatives and put extra blankets on the bed to try to keep warm.

“It’s kind of miserable,” she said. “We do have a gas fireplace that’s keeping us warm in one room. There’s some heat generating from the furnace, but with no electricity to the blower, it’s not circulating well.”

At one point, more than 820,000 customers in Michigan were in the dark. By Friday, that was down to under 600,000, most in the state’s populous southeastern corner around Detroit. But promises of power restoration by Sunday, when low temperatures were expected to climb back above zero (minus 18 Celsius), were of little consolation.

“That’s four days without power in such weather,” said Apurva Gokhale, of Walled Lake, Michigan. “It’s unthinkable.”

Tom Rankin said he and his wife were unable to reach his 100-year-old mother-in-law Friday morning by phone. The couple drove to her home in Bloomfield Township, Michigan, to find her in bed “with a whole lot of blankets,” Rankin said, adding they helped her to their car, planning to ride out the outage at another relative’s home.

“We’ve not had an ice storm in the last 50 years that has impacted our infrastructure like this,” said Trevor Lauer, president of Detroit-based DTE Electric.

At least three people have died in the storms. A Michigan firefighter died Wednesday after coming in contact with a downed power line, while in Rochester, Minnesota, a pedestrian died after being hit by a city-operated snowplow. Authorities in Portland, Oregon, said a person died of hyperthermia.

Much of Portland was shut down with icy roads not expected to thaw until Saturday after the city’s second-heaviest snowfall on record this week — nearly 11 inches (28 centimeters).

Tim Varner sat huddled with blankets in a Portland storefront doorway that shielded him from some of the wind, ice and snow. Local officials opened six overnight shelters but the 57-year-old, who has been homeless for two decades, said it was too hard to push a shopping cart containing his belongings to get to one.

“It’s impossible,” he said. “The snow gets built up on the wheels of your cart, and then you find slippery spots and can’t get no traction. So you’re stuck.”

In Northern California, snow piled up across Santa Cruz County as roads closed and motorists were forced to abandon their cars.

Not all were dismayed by the winter weather. In the San Francisco Bay Area, hundreds of people drove up to 2,500-foot (760-meter) Mount Tamalpais to play in the snow — a rarity in the area.

San Francisco resident Shankar Krishnan woke up at 4 a.m. and headed out hoping to see snow for the first time in a long time.

“It feels awesome. It’s like the trees are all frosty. There’s snow on the ground. There’s snow coming down from the sky,” Krishnan said. “It’s beautiful out here.”

Some schools in Nevada and northern Arizona were closed, and a Major League Soccer season-opening game in Southern California was postponed.

The storm has added to major precipitation from December and January “atmospheric rivers” that improved California’s drought outlook, but authorities who allocate water to farms, cities and industries remain cautious because of a recent history of abrupt changes in hydrologic conditions.

Associated Press writers Andrew Selsky in Salem, Oregon, Olga Rodriguez in San Francisco, Ed White in Detroit, John Antczak in Los Angeles and other AP journalists from around the country contributed to this report.