Thursday and Friday continue to look great for the practice sessions, with plenty of sunshine and comfortable temperatures and humidity as high pressure extends across the region.
The humidity will get noticeably higher on Saturday as the southerly flow of warm, moist air increases over the Finger Lakes region. The higher humidity, along with a weak upper level disturbance that will move across the area, will result in scattered showers and thunderstorms developing, mainly in the afternoon. There could be a potential for brief, heavy downpours. The exact timing is uncertain at this time, but the MPC race between 2:35 and 6:35 pm could be impacted.
There is some model disagreement regarding the timing of rain chances on Sunday. In my previous forecast, I mentioned that this was a slow-moving system. Most of the models have shown a slower system over the past couple days, which means that the main area of rain with the system could hold off until Sunday night or Monday. Still, with plenty of moist air in place and the approaching trough, scattered showers and thunderstorms will be possible during the WeatherTech Championship race. Like Saturday, there could be a heavy downpour, but I think it would be short-lived. Timing remains uncertain, but the afternoon will be favored for showers.