The weather forecast for Sunday doesn't look good and at the very least it appears that there is a good chance that the race might be delayed for sometime today. SB Nation's Brian Neudorff updates the situation:
As I stated above, it will rain today and rain will fall at the track. NASCAR will do everything it can and wait as long as necessary (see Atlanta's fall race last season) to get the race started and completed on Sunday. I'm stopping myself just short of calling today's 54th running of the Daytona 500 a washout, but the likelihood that this race gets moved to Sunday night or Monday is around 70 percent.
Neudorff also points out that during its 53 year history, no Daytona 500 race has ever been run on a Monday. Showers are expected to last into the evening time with a 50 percent chance of breaking up in time to make the 54th running a night race. There is also a chance that showers last into Monday which would lead to a potential late afternoon early evening start on Monday.