Some high clouds will be increasing on Saturday, but despite a few more clouds, temperatures will be a little warmer as winds shift to a southeast direction. Pro Mazda and USF2000 will have a beautiful afternoon for racing at Lucas Oil Raceway.
Confidence in a dry race on Sunday continues to rise as the high pressure ridge through the midlevels of the atmosphere appears to be slow to exit. The strength of this ridge is helping to keep an approaching low pressure system at bay to the west, and helping to keep the atmosphere over central Indiana more stable. I lowered the rain chance a little bit with this update, to 30%, and I think that most of that small rain chance will come after 4 pm. I also took out the mention of thunderstorms on Sunday, as it looks like there will not be much instability in the atmosphere. I expect that any rain that may occur on Sunday will be light.
I'll have another forecast update tomorrow morning, then a two-hourly forecast for race day. For updates on Twitter, follow @Race4caster and @RacecastWx.