A storm system headed east into parts of the Midwest states on Wednesday, caused a great menace to the plains with strong winds, large hail and reports of tornadoes, after initially dropping a foot of snow in the Rockies.

The system was expected to have affected more than 35 million people.

A blizzard warning was put into effect on Wednesday for parts of Utah, New Mexico, Wyoming, Colorado, Nebraska and Kansas. Sustained winds of 30 to 40 mph were expected, which could go up to 55 or even 60 mph.

The National Weather Service said the system carried thunderstorms from Colorado through Ohio and from Texas north through Michigan. At one point, it also issued tornado warnings for parts of Kansas, Iowa, Nebraska and Missouri.

The Illinois Emergency Management Agency issued an alert on Wednesday and advised residents to be aware of changing weather conditions.

The Nebraska State Patrol also reported quite a few minor accidents which involved vehicles sliding off icy roadways, but no injuries were reported. Authorities in Wyoming also shut down large sections of roadways.

Rich Thompson, lead forecaster at the Storm Prediction Centre in Norman, Oklahoma said, ”the large-scale weather system is behaving pretty much as we would have expected it.”

He said his office had received reports of tornadoes but, they could not be verified until survey teams were sent to the affected areas – parts of Nebraska and Iowa.

“It looks like the threat for damaging winds and occasional tornadoes will peak here over a couple of hours as this moves along the (Interstate 35) corridor and maybe a little bit east of that,” he said. “Overall, it’s pretty much going according to plan.”

There were reports of damage to buildings in Adams County, Iowa, the site of a reported tornado, Thompson said.

Denver International Airport spokesman H. Montgomery said no major delays were reported. However, in anticipation of the bad weather, airlines cancelled about 50 flights out of the airport’s 1,500 daily flights – and ground crews kept up with the snowfall.