Wild weather forecast: Snow, ice, rain, floods, tornadoes – then more bitter cold

A potent storm will continue to deliver a mix of snow, ice, rain, floods and possibly some tornadoes to much of the central and eastern USA into Thursday and will be followed by yet another blast of Arctic cold by week's end.

About 55 million people live where floods could occur Thursday.

Wednesday, the storm dumped heavy snow over the upper Midwest, closing schools and wreaking travel havoc on the roads and at the airports.

Some of the heaviest snow fell in Iowa and Wisconsin, where 6 to 8 inches was reported, according to the Weather Channel.

The Weather Channel named the system Winter Storm Indra. 

Even where the snow stopped falling in the Dakotas and Minnesota, howling winds led to whiteout conditions. A blizzard warning for this "ground blizzard" was in effect until early Thursday.

South of the snowy weather, heavy rain will pelt much of the Southeast and Mid-Atlantic into Thursday.

Along the Gulf Coast, severe storms were likely late Wednesday, and high winds and tornadoes were possible, the Storm Prediction Center said.

As much as 3 inches of rain could dampen some areas Thursday. Urban flooding is possible in the major I-95 cities from Washington to Philadelphia, New York City and Boston, AccuWeather said.

The weather service issued flood watches from North Carolina to southern New England, as well as part of southern Ohio, affecting tens of millions of people.

Once the storm moves offshore, the next Arctic blast will roar into the northern Plains and upper Midwest on Thursday and into the eastern USA by Thursday night. "High temperatures on Thursday will struggle to reach above zero from North Dakota to Wisconsin, with widespread wind chill values between minus 10 and minus 20," the weather service said.

Temperatures in the northern Plains will bottom out near 30 degrees below zero.

Friday may be Chicago’s coldest day of the winter thus far: The forecast high is in the single digits, AccuWeather said.

The intense cold will move into the East and South by Friday and into the weekend.

As frigid as this outbreak is, an even chillier, potentially record-breaking cold snap will roar into the north-central USA next week. 

"The coldest temperatures are yet to come," the weather service office in Duluth, Minnesota, said. "January will end with continued Arctic intrusions, with near-record cold temperatures possible toward the middle of next week."

Tuesday, the storm's havoc began: A 100-mile stretch of Interstate 80 was closed in Wyoming, dozens of accidents were reported in the Denver area, and hundreds of flights were canceled at several airports, the Weather Channel said. 

Fatal accidents involving vehicles sliding off icy roadways were reported in Wisconsin and Illinois on Tuesday.

Detroit Metropolitan Wayne County Airport closed Tuesday night because of the snow and reopened early Wednesday. Flights arriving to Chicago O'Hare International Airport were delayed by an average of six hours Tuesday night. 

Contributing: The Associated Press