Central US faces multiday severe weather threat 

Millions of Americans in the Central U.S. could see severe thunderstorms and tornadoes Monday night through Wednesday.

Severe thunderstorms are expected to touch down across the Central Great Plains and parts of Virginia and Maryland starting Monday night and continuing overnight, the National Weather Service's (NWS) Storm Prediction Center said.

Parts of the Great Plains could see scattered severe thunderstorms, along with "strong" tornadoes in Kansas and Nebraska. Large hail and damaging wind gusts are also possible in these areas, forecasters said.

The threat of tornadoes Monday will depend upon the development of large supercells — a tall system with a prolonged updraft in wind that can cause tornado and hail, the NWS noted.

Residents in parts of Virginia could experience "scattered severe gusts" starting Monday afternoon and continuing into the evening, forecasters added.

Once through the Great Plains, the storm could make its way Tuesday into the Mississippi Valley, Great Lakes and Ohio Valley, bringing "severe weather and isolated flash flooding," The Associated Press reported, citing the NWS.

Southern Iowa, northern Missouri and west-central Illinois are the most at risk of "severe hail and tornado potential" starting Tuesday, forecasters said. An isolated severe threat is also expected across parts of the mid-Atlantic states.

May is typically the midpoint of tornado season, Harold Brooks, a tornado scientist at the National Severe Storms Laboratory, told the AP. Late April to the middle of May is generally when the strongest, more deadly tornadoes can occur, he added.

Some scientists have suggested tornadoes in the U.S. are shifting, with more popping up in states along the Mississippi River and further east, the AP added.