See The Midwest Blizzard Live On-Air

From West Virginia to Alabama, about 60 million people started Monday under a severe weather threat. Storms in the East are bringing damaging winds and possible tornadoes. Before dawn we saw mounting reports of downed trees and power lines, and damage to homes and other buildings. By mid-morning travel delays and cancellations were skyrocketing.

This all comes after an unusual patchwork of severe weather across the U.S. threw out everything but the kitchen sink.

(MORE: Read Yesterday's Coverage As It Unfolded)

In the Midwest, roads became impassable as a winter storm brought heavy, record-setting snow to parts of Wisconsin and Michigan. Later, a tornado threat moved into much of the Ohio River Valley and Southeast, as the risk of severe storms lingered into the evening.

A major heat wave pushed temperatures near 100 degrees in the Southwest. Across the Plains, powerful winds with gusts up to 70 mph fueled extremely dangerous fire conditions that turned deadly in Nebraska. And in Hawaii, an atmospheric river dumped heavy rain, causing flooding and leaving thousands without power.

And those wildly opposing conditions have pushed into the work week.

Monday's Severe Weather

More than 520,000 customers were without power across the country Monday morning, according to PowerOutage.us. The bulk of the outages were in Michigan, where more than 129,000 homes and businesses did not have electricity. This social media post from a storm chaser in Michigan shows you why.

There have been more than 300 reports of severe weather since Sunday afternoon, and weather.com senior meteorologist Jonathan Erdman says most of those reports involve wind damage.

(MORE: Your Complete Severe Weather Forecast)

We're seeing a flurry of reports from neighborhoods and communities up and down the East Coast of downed trees and powerlines cutting off roads. Fire departments, sheriff's deputies and utility crews were out all night Sunday and early Monday inspecting damage and working to clear roads.

A church and nearby homes in Summersville, Missouri, were significantly damaged, with reports that the foundation of the church was lifted off the ground. In a Facebook post, a resident shared dramatic photos of the damage to one home.

Officials said schools in Raleigh and Chapel Hill, North Carolina, would be closed Monday, and the state's governor urged residents to enable emergency alerts on their phones ahead of expected wind gusts of 74 mph.

In Atlanta, public schools switched to remote learning as tornado watches were issued across the metro area. Other school districts outside of the city have delayed the start of classes by several hours. Washington, D.C., schools are closing two hours early.

In Alabama, the Morgan County Sheriff's department shared video of snow falling between Hartselle and Decatur. The National Weather Service also issued a Winter Weather Advisory, warning of scattered snow showers for north Georgia throughout Monday evening.

Travel Nightmare Grows

More than 4,000 flights were canceled nationwide, and delays were topping 14,000 by midday, according to FlightAware.com. By 11 a.m. ET the FAA had grounded flights at Atlanta's Hartsfield-Jackson International Airport, Charlotte/Douglas International Airport and Washington Dulles International Airport. There was also a ground delay at George Bush Intercontinental Airport in Houston due to winds.

The severe weather combined with the continuing government shutdown created a nightmare scenario for travelers trying to get through security in Atlanta. People were jammed together in long lines snaking through the airport Monday morning.

Austin-Bergstrom International Airport shared video of the astonishingly long lines of travelers waiting to get through security before daybreak Monday.

(MORE: Traveling Today? Check Our Travel Tracker)

Winter Storm Wallop

The snow totals in the Midwest are simply staggering. Leading the official record totals is the town of Mountain, Wisconsin, which has been socked in by 34 inches of snow. Erdman explains that with almost 23 inches of snow so far, Winter Storm Iona could be the heaviest snowstorm since the record early March 1888 storm in Green Bay, Wisconsin (29 inches).

The blizzard conditions and deep snow trapped people on highways through the region. Southbound lanes of Interstate 35 were shut down Sunday afternoon in southeast Minnesota. The state DOT said no travel is advised on state highways in the area.

In Wisconsin, dozens of vehicles were stuck on I-94 near Osseo on Sunday.

In Michigan, the Coast Guard and Mackinac Island firefighters pulled off a daring rescue in whiteout conditions after a man on a snowmobile went out onto the ice of the Straits and got lost.

Mackinac Island Fire Chief Jason St. Onge and five other firefighters went out on the ice, and the chief said: "It was extremely slow going as drifting snow was waist deep and the ice jagged and difficult to climb over."

A Coast Guard cutter was able to spot the man who had reached open water, and the crew picked him up and got him on board their vessel.

It took firefighters 40 minutes to walk 2,000 feet back to shore in the arduous conditions. In a press release, the Fire Department said, "The ice is no joke, not an inland lake or a mill pond, conditions can and do change by the minute. Not one entity endorses the ice nor is anyone in charge of its safety or security. Each and every trip is CROSS AT YOUR OWN RISK. In this particular case it was cross at the First Responders risk."

This is a developing story; check back frequently for updates.