NORMAN, OK - Forecasters are warning of hurricane-force wind gusts and hail the size of baseballs as a potent storm threatens to spin up tornadoes and drench the South with heavy rains.

The national Storm Prediction Center said more than 18 million people in Louisiana, Arkansas, Texas and Oklahoma will be at an enhanced threat of storms that could include strong tornadoes and flooding rains.

The area includes several major Texas cities including Dallas, Houston and Austin.

The National Weather Service said wind gusts could top 80 mph — the speed of a Category 1 hurricane.