Thursday will likely have the best weather of the event, with just a small chance of an afternoon shower or thunderstorm. The chance of rain will trend upward, due to a slow-moving low pressure system over the Ohio Valley region that will pump moisture into the Finger Lakes region over the weekend. As the low tracks slowly northeast, showers and thunderstorms will become numerous Friday and Saturday. The highest chance of showers and storms will be in the afternoon hours, but they are possible at any time of the day. I expect that the rain may be heavy at times, along with frequent lightning, which may cause delays and stoppages during some of the on-track sessions.
The low pressure system will be over New England by Sunday, which will cut off the feed of moisture to the area, and lower the chance of showers and storms. Still, there could be enough instability to produce some scattered afternoon activity that could impact the race. With some periods of sunshine between the clouds, temperatures could rise to around 80 degrees.
Check back later in the week for updates.