A powerful storm system will bring several life-threatening weather hazards to Tennessee starting Wednesday night, including the threat of flash flooding and tornados, warns the National Weather Service.

A Tornado Watch has been issued for the western half of the state through 1.am. A powerful squall line has formed across Illinois and will is moving into western Indiana. Damaging winds, large and

On Wednesday at 11:37 p.m. the National Weather Service issued a tornado watch in effect until Thursday at 6 a.m. for Colbert and Lauderdale counties.

The national weather service issues watches and warnings for tornadoes and severe thunderstorms. What's worse? What do they mean?

This will bring periods of showers and thunderstorms. Strong storms will still be a threat, but the greater issue will be heavy rainfall. If this does occur, which appears likely, significant flash flooding will occur starting late Thursday and lasting through Sunday.

On Monday at 6:12 p.m. the National Weather Service released a tornado warning in effect until 6:45 p.m. for Berks County.

"TAKE COVER NOW! Move to a basement or an interior room on the lowest floor of a sturdy building," the tornado warning said. "Avoid windows. If you are outdoors, in a mobile home, or in a vehicle, move to the closest substantial shelter and protect yourself from flying debris."