Thursday still looks like quite a wet day at the track as a low pressure system will be moving east across the region, and it may affect the amount of practice time that teams have. It doesn't appear to be a very heavy rain, more of a steady light to moderate soaking that could bring around a quarter of an inch of rain (around 6 mm). I think there could be enough standing water to cause practice sessions to be delayed or canceled.
Friday will start with cloudy skies as the low pressure system moves farther away, but conditions should be improving through the day. At least some partial sunshine is expected in the afternoon, and high temperatures will be in the mid 50s.
Race day on Saturday will likely have the best weather of the event, with mostly sunny to partly cloudy skies, and temperatures reaching the lower 60s. Clouds will likely be increasing through the day, and rain is expected to start to move into the area around sunset. However, all signs point to rain holding off until well after the race ends.