Up to 59 million from Texas to Michigan are under severe storm risk as heavy rains, flash flooding and strong tornadoes are forecast to hit the lower Ohio Valley and the mid-South.

Severe weather is predicted for the central United States, including potentially deadly tornadoes, large hail and localized flooding that could affect as many as 32 million people through Sunday from Dallas to Cleveland.

Forecasters issued some of their rarest and most extreme alerts on Wednesday as they warned a powerful storm system would stall over the central part of the country.

We're tracking an expected tornado outbreak today, with severe weather threatening millions across multiple states. Here is the latest.

Tornadoes touched down in Owasso, Oklahoma this Wednesday morning, tearing a few roofs off homes and ripping several trees out of the ground. That was just the start of what's expected to be a "high risk" severe weather system.

Overnight, two tornadoes were reported in Kansas. Hail larger than golf balls was reported in Oklahoma. And 80 mph winds were reported in Nebraska.

Millions of people are under tornado watches across the central United States on Sunday, as a volatile weather system has triggered power outages and huge hail. Nearly 175 million people from Illinois to eastern Texas and beyond could be affected,

The potential for a new, large area of severe weather will ramp up over the central United States this weekend, Accuweather forecasters say.

While tornado watches are in effect, damaging wind gusts and large hail remain the primary hazards from any severe thunderstorms on Sunday.

Tornadoes can be a year-round menace in parts of the United States, migrating north and south with the spread of warm, humid air and the jet stream.