Millions in path of potential bomb cyclone as major winter storm slams central U.S.

All runways at Denver International Airport were closed Wednesday amid whiteout conditions. 

By Kalhan Rosenblatt and Phil Helsel @ NBCNews.com, Updated March 13, 2019, 11:17 PM EDT, WITH VIDEO

Colorado’s governor declared a state of emergency Wednesday and authorized activation of the National Guard as millions across the central United States dealt with a major storm system.

As many as 74 million people are expected to face some type of severe weather ranging from blizzard conditions to heavy rain and flooding as the major winter storm moves through the central part of the country [....]

In Colorado, the storm underwent bombogenesis — also known as a bomb cyclone — according to The Denver Post, a term used when a storm drops 24 millibars, or units of atmospheric pressure, in 24 hours or less, according to Weather.com.[....]

Blizzard warnings stretched on a large swath of the central U.S., from eastern Colorado and Wyoming, portions of Nebraska and large parts of the Dakotas and into western Minnesota as of Wednesday night, while eastern Nebraska, southeastern South Dakota and parts of Iowa were under flood warnings [....]

Severe thunderstorm warnings also stretched from southwestern Texas to parts of Kansas, according to the weather service. Parts of Wisconsin and Michigan were among the areas under a flash flood watch [....]