Volatile spring weather will kick into high gear this week as a potential severe thunderstorm outbreak and life-threatening flooding loom large for tens of millions of people in the central and eastern United States.

A tornado outbreak is expected through tonight in parts of the Midwest and South, prompting a rare "high" risk severe weather outlook to be issued.High-risk severe forecasts (level 5 out of 5) are only issued two to three times a year by NOAA's Storm Prediction Center for particularly volatile setups like today.

A tornado outbreak is expected Wednesday and Wednesday night from parts of the mid-Mississippi and lower Ohio valleys westward into the eastern Ozarks, prompting a rare Level 5 out of 5 "high risk" of severe weather.

As thunderstorms threatened to hit parts of the Midwest and South, forecasters warned of flash flooding and tornadoes.

Potentially deadly flash flooding, high-magnitude tornadoes and baseball-sized hail could hit parts of the U.S. on Wednesday as severe thunderstorms blowing eastward become supercharged,

A storm system that brought severe weather to the central states over the weekend will spread through the South and East Monday. Damaging winds, large hail and a few tornadoes are potential threats.

A spring storm system will move east over the next three days, bringing a variety of dangerous and life-threatening weather from the Heartland to the East Coast.

More than 180 million people could see severe weather through midweek, with more than two dozen states at risk, according to AccuWeather.

WEST MICHIGAN — National Weather Service officials in Grand Rapids have now confirmed FIVE tornadoes from Sunday's deadly severe weather outbreak.