As I mentioned yesterday, one scenario was that there would be two rounds of showers and storms on Sunday. I think that this is going to be the scenario that plays out. However, it's not all bad news!
I expect that a round of showers will move through central Indiana Sunday morning. These showers will be the remains of dying storms overnight that will move in from the west. This round will likely not be heavy, and while there may be some lightning possible with it, I don't think lightning will be frequent or widespread enough to be a big issue at the Speedway. There may be around a tenth of an inch of rain with this round of showers. The most likely time for these showers to occur will be between 9 am and noon. This may interfere with the morning practice sessions. It is possible that the decaying showers could die completely before reaching the Speedway. However, I think it is likely that there will be some rain occurring in the mid to late morning.
The second round is expected to be more significant than the first. The Storm Prediction Center has a Slight Risk of severe storms for central Indiana on Sunday afternoon, which means a 15% chance of severe storms in any location.
The big question with this second round is timing. The two qualifying sessions are scheduled to be held from 12:15 to 2:15 pm EDT. I expect that the second round will arrive after 2 pm at the very earliest, and more likely after 4 pm. If the first round doesn't drop too much rain and track drying does not cause too much of a delay, I think that qualifying can be completed. I do think that the practice session scheduled from 3:15 to 6:00 pm will be interrupted. The storms will move through quickly but they could dump some heavy rain in a very short time, possibly a quarter to a half inch. Again, strong winds and lightning will pose a real threat, so take any calls for action seriously.
I have changed the Impact to Moderate with a yellow flag, meaning that there may be some delays and possibly cancellations to the practice sessions, but qualifying should be able to get in as scheduled if the timing plays out as expected.
Of course, the weather doesn't always do what we expect, so we'll hope for the best and watch how it develops. I won't be able to provide regular radar updates on Sunday until the mid afternoon, but you can use our radar link at the top of the page to keep up with the weather.