A thunderstorm struck Peoria (Ill.) Speedway just before the start of Thursday night's DIRTcar Summer Nationals consolation, forcing officials to postpone the remainder of the program to July 21.

The July 21 date — an open stretch on the revamped Summer Nationals schedule — will include the Late Model consolation and 40-lap, $5,000-to-win feature as well as the 25-lap UMP modified A-main.

The Summer Nationals continues with its third round of action Friday at Tri-City Speedway in Granite City, Ill.