UNITED STATES - Severe thunderstorms, large hail, damaging winds, and tornadoes hit the southern United States on Sunday, ahead of what The Weather Channel is calling a strong upper-level system pushing into the southern Plains.

AccuWeather reports that multiple tornadoes have already been confirmed in Texas. As of 9:00 PM CDT, one tornado was confirmed near Cross Plains, Texas and another near Comanche, Texas.

"Severe thunderstorms will continue to fire across parts of Texas and Oklahoma through Sunday evening. The strongest storms will target northern Texas, including Dallas," AccuWeather.com Meteorologist Andy Mussoline said. "The most violent thunderstorms will be capable of producing tornadoes, some large and hail up to softball size." 

The Weather Channel is predicting 1-3 inches of rain from the Texas and Oklahoma Panhandles to portions of Louisiana through Monday night, with localized flash flooding possible in these areas as well. Among the cities that could see flash flooding through Monday night are Oklahoma City, Dallas-Fort Worth, Houston, and New Orleans.

As of 9:00 PM CDT, Tornado watches have been issued for the following areas:

• Central Texas, including Dallas-Fort Worth as well as Waco and Stephenville.
• Coastal Texas, including Houston, Galveston, and Freeport.
• North Texas, including Abilene, Childress and Wichita Falls.
• Southwest Oklahoma and the southeastern portion of the Texas panhandle, including Clinton and Altus, Oklahoma.

These storms are expected to last through Monday evening.

Stay tuned to AndNowUKnow for continued updates on the latest weather developments.