To open the weekend, high pressure from the surface through the midlevels will be located off the coast of New England. Stable conditions and very dry air aloft will result in sunny skies at the track on Friday, with pleasant temperatures in the lower 80s in the afternoon. Humidity levels will also be quite comfortable, with dewpoints only in the upper 50s.
High pressure will start to move away and a couple of low pressure systems will be developing and moving toward New England on Saturday. One will be moving east along the Michigan/Indiana/Ohio border region, while another forms off the North Carolina coast and tracks north. It is the speed of this coastal low that brings some uncertainty into the forecast. Yesterday, the models were in good agreement that rain would hold off until Saturday night. Now, one model is bringing the rain in faster again, like it had been a few days ago. It is an outlier, with other models still bringing in rain well after racing has ended. I still think the slower development of this pattern is more likely, based on my experience. So I'm sticking with a dry forecast, but not with 100% confidence.
I'll have another update up on Friday morning, unless there's a change that requires an update tomorrow. Let's hope that's not the case.