SPARTA, Ky. (AP) — NASCAR has postponed Friday's Xfinity Series event at Kentucky Speedway after severe thunderstorms threatened the area shortly before the green flag.

The postponement follows Thursday night's rain-delayed Camping World Truck Series race that began three hours late and concluded early Friday morning. Cup series qualifying had just concluded its second round Friday evening before dark clouds gathered over the track and led officials to cancel that session and quickly postpone the Xfinity race to Saturday at noon ET.

Cup series regular Kyle Busch will begin on the pole in a Toyota, the first of No. 1 starting spots he claimed on Friday. Busch ran a fast lap of 181.935 mph to top Erik Jones, who clocked 181.635 mph to earn the second spot.