A cold front is expected to pass through Indiana on Wednesday, and stall near the Ohio River on Thursday. Meanwhile, a low pressure system wil be taking shape over the Plains, then track east. This system will pull that front back to the north and track along it, right across central Indiana on Friday. This will make showers likely at the Speedway, with a chance of some thunderstorms as well. As of today, I think most of the rain will fall during the morning hours, but there could be showers and storms that persist into the afternoon. So I don't expect that there will be much on-track activity on Carb Day. I'll keep monitoring this system through the week, so stay tuned for updates.
The chance of rain on Saturday morning will depend on how quickly the low pressure system exits to the east. The chance of rain will continue until the upper trough moves east of Indiana, which is expected to occur on Saturday morning. There may be a light shower around sunrise, however most of the day should remain dry with no impacts to Legends Day.
High pressure will start to build over the region on Saturday, and will be firmly in control of the weather pattern on Sunday. As a result, race day will be dry with mostly sunny skies and temperatures in the mid to upper 70s. It will be a beautiful day to watch the Greatest Spectacle in Racing.