On Saturday a cold front will be approaching the area from the north, which will bring a better chance of showers. The timing is too uncertain to pinpoint this far out, but the coverage of showers appears to be scattered at this time, so I do not expect it to be a persistent all-day rain - passing on/off showers are more likely. The impact on the racing should be low, which means that all scheduled events should be able to be completed.
The front should be through the area by Sunday morning, but there will still be an upper level trough over the region. Under this trough, there could be some light showers in the Watkins Glen area, but most of the activity should stay to the east, near Albany. I'm uncertain enough about the location of the showers that I am putting in a 20% chance of rain, but I don't think it will have an impact. Temperatures will be cooler and winds will be stronger on Sunday.
Check back through the week for updates to the forecast.