Severe weather was moving into the four main counties in the WFAA viewing area late Saturday night. News 8 Doppler Radar showed heavy rain and lightning across the northern part North Texas, tracking very slowly toward Dallas-Fort Worth.
At 10:20 p.m., the heaviest storms were in the northeast corner of Grayson County, packing winds up to 65 mph.
Residents of Olney reported dime-size hail and some trees and power lines down, but no major damage.
Meteorologist Steve McCauley said 70 percent of North Texans can expect to get wet overnight, and some of the storms could be severe. The system was expected to clear the region by 7 a.m. Sunday.
Earlier, the storm system passed through Abilene, dropping quarter-size hail around 6 p.m. Saturday.
Saturday night's featured concert at the State Fair of Texas was cut short by three songs as a precaution, but the Midway remained open until its regular 10:30 p.m. closing time.
Reporter Wendy Corona in Denton and meteorologist Steve McCauley in Dallas contributed to this report.