Communities in Texas and Oklahoma were warned to prepare for potential tornadoes Monday as a system threatening severe thunderstorms developed over the region.

The Weather Channel raised its TOR:CON index to 5 in parts of the two states, meaning there was a 50 percent chance of twisters developing within 50 miles of the affected areas.

The threat area was expected to move over Dallas and Oklahoma City on Monday evening, although it was possible the tornado threat would diminish to one of rain and damaging winds, forecasts said.

"It's a really sizable storm," Roth said. "There's a pretty good chance we'll see tornadoes later today."

The system was expected to track east through Tuesday and Wednesday, with rain, damaging winds and possible tornadoes from Texas to Mississippi on Tuesday, and a possible lingering severe threat as far east as Florida on Wednesday, according to The Weather Channel.