(CNN) - A major winter storm is coming to the heartland of the country Wednesday.
It's called a "bomb cyclone" which is a rapid drop in pressure over 24 hours.
Among the areas expected to get hit hard: the Central-Northern Plaints, the upper Midwest and the Rockies.
People who live there should expect blizzard conditions, heavy wind gusts and possible tornadoes and flooding.
Tens of millions will be affected by these conditions.
Flight Aware reports more than 1,000 flights have already been canceled for Wednesday.