I think if this track did not have lights they would've been postponed it until tmr but when you have lights it gives you more time to wait out the weather. In Texas it is only now approaching 4 PM so I'm guessing if they can get it started by 6 PM local time they will do it.
I just realized why no race was ran on saturday. It was supposed to be a saturday night cup race but due to the final 4 being in texas they had the race scheduled for sunday afternoon instead