A deadly winter storm that began in California is now barreling across the nation's midsection, dumping heavy snow and freezing rain in parts of the Midwest.
About 60 million people -- 20 percent of the U.S. population -- are under winter weather warnings, watches and advisories in the 750,000 square miles affected.
On Wednesday, the winter storm system left a rare, thin layer of snow across the deserts of Arizona, New Mexico and Southern California.
Snow, hail and rain fell in the Phoenix area, normally accustomed to dust storms, not snow storms.
"I've been here for over 10 years and I've never seen it snow like this," Kayla Avery of Tucson, Ariz., said in a CNN iReport.
Mona Jensen took this photo Wednesday on her 8-acre property in northwest Arizona. "The Joshua trees and cactus are plentiful," she said. "However, snow is usually not. It began snowing overnight and continues today, draping everything in white, wet snow."
Up to 15 inches of snow was forecast for the Arizona mountain community of Flagstaff. A winter storm warning was in effect and all area schools have canceled classes.
In California, hundreds of drivers were stranded on a mountain highway between Los Angeles and Bakersfield as heavy, sudden snow hit the area.
Up to 2 inches of snow was expected in elevations from 2,000 to 3,000 feet in California, and up to 5 inches in higher elevations. Ski resorts around Lake Tahoe could see up to 8 inches of snow, according to the National Weather Service.
Katie June in Yucca Valley, Calif., shared a shot of snow-covered cacti with CNN. "Some of the larger ones are having a hard time," she wrote. "But they all enjoy the drink!"
Here, a snow-covered motorcycle sits near snow-covered parking meters and cactuses in Yucca Valley.
The storm began rolling into Plains states like Kansas early Thursday.
Dodge City, Kan. "is in the middle of a bull's eye," CNN meteorologist Chad Myers said. The state should see 16 to 18 inches of snow west of Wichita, with the white stuff continuing up into Nebraska.
Kansas City International Airport in Missouri announced that some flights were canceled. Kansas City could see its highest daily snowfall since 1912, if predictions of nearly a foot of snow pan out.
A rare combination of thunder and snow lit up the skies over Springfield, Mo., and parts of Wichita, Kan., early Thursday.
People in Oklahoma City awoke Thursday to snowfall. On Wednesday, roads were covered with a slushy mix of snow and ice that officials said caused a crash that killed 18-year-old Cody Alexander of Alex, Okla.
Doug Simonton snapped this photo outside his window in Tulsa, Okla. "... heavy snow has been falling since the overnight hours and there have been multiple car crashes (no significant injuries thus far). Approx 4" to 5" have fallen so far with more on the way," he wrote.