The Continental Tire SportsCar Challenge Oak Tree Grand Prix has been red-flagged after 30 minutes of running due to torrential rain, thunder and lightning at Virginia International Raceway.
Rain descended upon the 3.27-mile circuit just past the 15-minute mark, prior to the race going under full-course caution roughly five minutes later.
The surprise conditions, which were not initially forecast, sent teams scrambling for wet weather tires, with IMSA red-flagging the race due to track flooding with 1 hour and 58 minutes remaining.
The No. 76 C360R Ford Shelby GT350R-C of Paul Holton currently leads the race, with Jason Rabe out front in ST in the No. 31 Bodymotion Racing Porsche Cayman.
A number of cars had spun while under yellow, even on wet-weather tires, prior to the red. Per IMSA, the safety car was instructed to drive at 15 mph, due to the conditions.