Today looks like a sunny and warm day, with temperatures reaching the mid 80s. I think the high pressure ridge will still exert enough influence over Indiana to prevent much shower development today.
Clouds will increase tonight as high and midlevel clouds from upstream thunderstorms move into Indiana. While there could be a chance of showers any time during the day Friday, I still think the best chances will come in the afternoon, as the approaching midlevel disturbance will be aided by some instability from afternoon heating. I do not expect that any storms on Friday will be strong or severe.
While the timing of the midlevel disturbances is uncertain, it appears that Friday night still looks like the time for the highest chances of showers and thunderstorms. Once this disturbance moves through, there could be a dry period behind it, possibly Saturday morning and into the early afternoon. The famous "window over Terre Haute" may be a term that is tossed around quite a bit on Saturday, because another round of storms may be approaching late Saturday afternoon and evening. This round has some potential to have some strong storms. Again, the exact timing is highly uncertain, but this is my best estimate at the moment.
This will be a situation where the radar will need to be watched closely. You can keep an eye on the Indianapolis radar through the Indy Radar link at the top of this page. I'll have weather updates on my Twitter account, @Race4caster.