The National Weather Service has issued a Tornado Warning for Lincoln and Pottawatomie Counties until 7:30 p.m.
The Norman Forecast Office says a new tornado is likely developing north of I-40 along the Lincoln-Pottawatomie County line.
Nearly 7,600 OG&E customers in Central Oklahoma are without power, according to the utility's System Watch.
More says severe thunderstorms are possible until midnight, with hail up to the size of baseballs and 70-mile-per-hour wind gusts as the main threats with some of the stronger storms.
Tornadoes are also possible, especially in the area from north of Oklahoma City to Medford and Ponca City.
KGOU is currently broadcasting Channel 5 KOCO-TV's First Alert Weather Coverage. Watch here.
Forecasters say instability and wind shear are forecast to increase Sunday, leading to a "significant severe weather outbreak."
Strong winds caused damage and power outages Saturday as thunderstorms collapsed.
Officials are encouraging residents to prepare for the possibility of large hail, damaging wind and tornadoes. They also recommend having three different ways to receive emergency information, including the use of weather alert radios.
The storms could continue into the late night hours, making it more difficult to see approaching tornadoes.