The storms brought rain, snow, hail and severe weather across a wide swath of the country.

Here's the latest:

Bizarre December Weather Leaves Historians in Awe

Wednesday's widespread windstorm, severe weather outbreak and unusual heat from the Rockies and Plains into the upper Midwest were so bizarre for December that even weather historians were in awe.

"I can say with some confidence that this event - the heat and tornadoes - is among the most, if not the most, anomalous weather events ever on record for the upper Midwest," weather historian Christopher Burt said.

Prior to this outbreak, there hadn't been a December tornado documented in Minnesota dating to 1950.

And that's just one of a long list of notables. Click here to read more.

Death Toll Rises to Five

Four additional deaths are being connected to Wednesday's storms, according to the Associated Press, adding to one reported earlier.

A 65-year-old man died in Olmsted County, Minnesota, when a 40-foot tree fell outside his home, and three people were killed in two separate car crashes in Kansas blamed on blinding dust kicked up by high winds.

Homes Evacuated Due to Wildfire in Kansas

Some residents in Quinter, along Interstate 70 in the northwest part of the state, were told to leave their homes after a wildfire broke out amid the high winds, the AP reported. Sheridan County Emergency Management Director Don Koerperich said the fire wasn't near any large population areas.

Fires were also reported in other parts of Kansas as well as in Oklahoma and Texas.

Truck Driver Killed in Iowa

The driver died when high winds rolled the vehicle onto its side on southbound U.S. Highway 151 in eastern Iowa on Wednesday evening, the AP reported, citing the Iowa State Patrol.

Power Outages Top 500,000

More than half a million homes and businesses were without power in eight states as of about 11:30 a.m. EST Wednesday. The bulk of those were due to high winds in Michigan (239,000 outages) and Wisconsin (138,000).

The rest are in Colorado, Kansas, Iowa, Missouri, Illinois and Minnesota.

Each power outage represents a single customer account, meaning millions are impacted by the widespread outages.

Storms Met Derecho Criteria

Derechos are large clusters of high-impact and long-lasting thunderstorms that most commonly form in late spring and summer and cause widespread destruction to trees, power lines and sometimes structures.

From the Spanish word for "straight," these windstorms leave wide, long areas of straight-line wind damage. The winds can be as strong as 60 to 100 mph or higher in extreme cases. They're usually produced by one or more curved lines of thunderstorms known as a bow echo or squall line.

A single severe thunderstorm may produce an area of damaging winds only a mile or two wide and a few miles long, but derechos can produce damage tens of miles wide and hundreds of miles long. They should cover a distance of at least 250 miles, according to a 2005 study by Walker Ashley and Thomas Mote.

Click here to read more about these types of storms from our weather.com meteorologists.

And here's a look at the highlights from Wednesday afternoon into the late night:

Airport Control Tower Evacuated in Kansas City

The air traffic control tower at Kansas City International Airport was evacuated at about 5:50 p.m. CST.

"KCI Airport is at 'Air Traffic Control (ATC) Zero,'" an update on the airport's Twitter account said. "For their safety FAA staff in the tower cab evacuated. This means there is no Air Traffic Control for flights at the airport. There will likely be diversions and delays. Anticipate 1 hour."

A follow-up tweet at 6:36 p.m. CST said staff had returned to the tower and flights would resume as soon as runways were checked for debris.

Gusts up to 100 MPH Blow Off Roofs

Here are some notable reports of high winds, hail and damage from the National Weather Service into Wednesday evening:

Sterling, Nebraska: Large trees uprooted, roofs blown off outbuildings.

Near Emporia, Kansas: Softball-size hail reported (4 inches diameter).

Near Boys Town, Nebraska: Roof blown off home.

Russell, Kansas: Roof blown off; 100 mph measured gust.

Ellinwood, Kansas: Roof blown off.

Pawnee City, Nebraska: Lots of structure damage, roof damage, carports damaged.

Hampton, Nebraska: Windows blown out of vehicles on Main Street.

Aurora, Nebraska: Stadium bleachers overturned, some structural damage.

Junction City, Kansas: Metal signs bent, siding off buildings, damage to hangars at Junction City Airport.

Colorado Fire Department Gets More Than 600 Calls For Service

The Colorado Springs Fire Department received 635 calls for service over the course of five hours. Incidents ranged from fires to downed power lines and trees to roof damage - at their own headquarters.

Damage Reported to Homes, Businesses in Nebraska

A home was damaged in Platte County, about 75 miles west of Omaha. Damage was also reported in Johnson County in the southeast corner of the state and other areas.

The NWS said a tornado was on the ground in Platte County and there was also hail.

Tornado Sirens Heard in Omaha

Driver Ejected in Wind-Related Crash

A truck rolled over in winds in Missouri, injuring the driver and spreading debris along the roadside.

Evacuations Urged in Texas Wildfire

A wildfire was fueled by high winds in the Oklahoma Panhandle. Some residents in Guymon, Oklahoma, were urged to evacuate.

Tree Crushes Car in Wichita

Reports of downed trees and power lines came in from several locations, including this one in Wichita.

Under a High Wind Warning? Here's How to Prepare

High winds may not get the attention that tornadoes and hurricanes rightly receive, but they can be dangerous.

They can occur in severe thunderstorms, accompany strong low-pressure systems, or even occur on a sunny day.

High winds can knock out power, down trees, and, in rarer cases, can lead to roof damage.

The National Weather Service (NWS) issues high wind watches and warnings when these potentially damaging winds are either possible or expected.

Here are some tips to keep in mind when you are in a threat of high winds.

Tree Falls on House in Denver

Another tree blocked a road, and residents were reminded to stay away from downed power lines.

Home Blown Off Trailer in South Dakota

A manufactured home came off its trailer amid high winds and low visibility on Highway 44 east of Farmingdale.

Portion of Interstate 70 Closed in Kansas

I-70 in Western Kansas was closed in both directions from Hays to the Colorado State line, according to the Kansas Highway Patrol.

That's a distance of about 160 miles.

"The second wave of winds and dust is headed for Hays. Reports of windows blow out in Wakeeney," a KHP trooper said in tweet at 1:15 p.m. CST. "PLEASE DELAY TRAVEL UNTIL THIS PASSES!"

Airport Delays Stack Up

Nearly 500 flights were delayed and 131 canceled at Denver International Airport as of about 12:15 p.m. MST, according to flight tracking website FlightAware

Highways Shut Down or Restricted in Colorado

Highway 50 in southeastern Colorado was closed as of about noon from Las Animas to Lamar – about 38 miles – according to the Colorado State Patrol.

Southbound Interstate 25 was closed to all commercial vehicles at milepost 63, Monument Hill.

Tens of Thousands of Power Outages

About 60,000 homes and businesses in areas hit by high winds were without power as of about 1:30 p.m. EST, according to poweroutage.us. Most of them were in Colorado (33,669), New Mexico (15,268) and Texas (11,747).

About 30,000 power outages remained in California from Tuesday and overnight.

Wind Blows Snow, Dust

Video posted to Twitter by Don Steerman, who said he was at work in Lamar near the Kansas state line in southeastern Colorado, resembled the scene of a wildfire. Wind blew snow and dust, turning skies an eerie orange.

Similar images of dust in the windstorm were shared from Colorado Springs.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.