As teams set up at Belle Isle on Thursday, there will be rain in the area. A cold front will be pushing through the area, and while the heaviest rain will be to the south across Ohio, up to a quarter inch of rain may fall at Belle Isle on Thursday.
Once the front exits Thursday night, a cool and dry air mass will build in from the north. Friday will be a beautiful day for racing, with sunshine and high temperatures in the lower 70s. Even better, Friday is Comerica Bank Free Prix Day, with no charge for admission. Free racing and nice weather - it doesn't get any better!
Saturday will have more cloud cover, but still a fair amount of sunshine, mainly in the morning. A southwest wind at 10 to 15 mph will raise temperatures into the mid 70s in the afternoon. Clouds will be increasing through the day as another cold front approaches from the north. However, at this time I expect that any rain with the front will hold off until after the racing is done for the day (the IndyCar race ends at 6 pm). There is a concert after the race which may have a chance of being impacted, but at this time I only have a 30% chance of rain during the daylight hours. Rain is most likely to arrive overnight.
The cold front should be through the area by the time on track action starts on Sunday morning at 10:45. There is a chance of the timing changing with later forecasts, but for now I'm going with a dry and mostly sunny day. Winds will shift to the north behind the front, with temperatures topping out around 70.