Clouds will be building back over Indiana tonight as a trough of low pressure over the Plains pushes east. The forecast trend of the past few days has been for this system to be slower and slower to move east, and that trend appears to be continuing today. This is good news for a dry Indy 500, as it looks like most of the rain with this system will hold off until Monday. There does appear to be a weak upper level disturbance that could move across the area on Sunday, which is why I will continue to mention some sprinkles being possible. I don't think this will have any impact on the race. Any chance of measurable rainfall should hold off until Sunday night. I think there will be enough sunshine peeking through the clouds to bring temperatures close to 80 degrees.
I'll have a detailed forecast for race day, with conditions every two hours, posted tomorrow morning.