Here are the various ways the upper atmosphere can make it rain over Indiana.

Friday afternoon, we see a hot dome over the Desert Southwest and a low over northern Quebec. The middle of the atmosphere over us is well primed to trigger the odd shower Friday afternoon into Friday evening. Fortunately the atmosphere will be dry. The meandering 582 hPa isohypse over Manitoba, a pseudopod from the Desert Southwest heat dome, is getting ready to screw with our weather

Now watch as the ridge presses northeast into Manitoba. It’s blocked. This is Saturday’s picture, with lots of instability and what GFS believes will turn into a cutoff low digging southwestward through the plains. (What looks like speckling over Missouri is mesoscale activity: a complex of thunderstorms.

This is Sunday evening. A cutoff low has developed over Iowa and Missouri. (The red dashed line at 570 dam hints at the location of the cutoff low. A warm front (where the black isobars show a bulge to the right is placed roughly at US 30. This sort of storm is more like what we would see in the colder half of the year. It also appears to be occluding as the cold front undercuts the warm front, which signals that the low is fated to dissipate.

The low at the surface will weaken as it tracks toward Minnesota. The trough or cutoff low will eject northeastward.

Five models offer five different predictions for the rain through 8 pm Sunday.

Hi-res Euro: 1.5 to 3.5 inches
GFS: 0.7 to 0.9 inches
Canadian: 1.5 to 1.9 inches, with a sharp increase at the Illinois state line.
UKMET: 3 to 5 inches
NAM: 0.5 inches

What they seem to have in common is that actual precipitation will vary quite a bit with location.

So, for us, it looks like temperatures in the 70s, maybe low 80s, no complete rainouts, but lots of showers and thunderstorms, with the possibility that the storms will track each other.

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