With heavy rain from Hurricane Hermine expected in the area, NASCAR has called off all on-track activities Friday at Darlington (S.C.) Raceway.
An updated schedule for activities leading to Sunday's Southern 500 will be released later Thursday. Two practices were scheduled Friday for Saturday's Xfinity race, as well as two Cup practices.
The weather forecast for Darlington is better for Saturday and Sunday, with highs in the 80s and a 10 percent chance of rain both days.