As of late this morning, the Samsung Mobile 500 is on track to start as scheduled, despite precipitation in the area.
Here's the latest from a TMS news release:
A light mist is hovering over Texas Motor Speedway, but a break is expected by early afternoon according to the National Weather Service and allow for the running of the Samsung Mobile 500 NASCAR Sprint Cup Series race.
Once the mist subsides, the jet dryers immediately will take to the track to begin drying the 1.5-mile oval in preparation for the start of the Samsung Mobile 500. The Samsung Mobile 500 currently is scheduled for a 2:16 p.m. CT green flag.
Updates on the weather and start time will be announced as further information arrives.
UPDATE: There's a rain delay at TMS. No sign of when they might get started. Follow ESPN.com's live chat here for the latest.