A 30-minute storm Saturday soaked the track, delaying the 9-10:50 a.m. session. Nationwide Series qualifying is set for 12:10 p.m. followed by Cup qualifying at 2:10 and then the Nationwide race at 4:50 p.m.
Rain also could threaten the Crown Royal 400 on Sunday.
The National Weather Service predicts a 30 percent chance of rain for much of Saturday, then 70-80 percent Saturday night through sunrise. There is a 55 percent chance of rain Sunday afternoon.
If Cup qualifying gets rained out, the lineup will be filled by the top 35 teams in owner points, past champions, and then the final spots are awarded based on qualifying attempts, with ties broken by points.