Tornadoes are possible in parts of the Heartland Wednesday, as severe weather is expected to move through the region.

A tornado watch has been issued for portions of six states -- Nebraska, Iowa, Kansas, Missouri, Oklahoma and Texas -- through 11 p.m. CDT Wednesday, the National Weather Service said.

Isolated tornadoes could be possible, especially in an enhanced risk area from Oklahoma City to Wichita Falls.

Huge hail and damaging wind gusts up to 75 mph are also possible as the storm system moves out of the West and into the Plains Wednesday night. An enhanced risk has been issued for areas including Omaha and Lincoln, Nebraska, for very large hail and significant, damaging winds.

By Thursday, the severe weather threat stretches from Austin, Texas, to St. Louis, Missouri. A line of severe storms is forecast to stretch across the region, packing damaging winds and large hail, from mid-afternoon into the overnight hours.

The storms may weaken a bit overnight Thursday as they move toward the Mississippi River and Gulf Coast, but severe activity could extend into Friday morning.