Here’s an animated gif with TWN data from the June 8 rainstorm, as measured at the IU South Bend station, showing the preceeding darkening as clouds rolled in coupled with decreasing distance to lightning strikes. Once the short-duration rain hit, the temperature dropped rapidly, and then the distance to lightning strikes increased again.

The rain measured at the Notre Dame River Observatory (NRO), which is right on the river a little south of Niles, started earlier and lasted longer, but was less intense than was measured at the IUSB station. Not surprisingly, the observed temperature drop was less drammatic at the NRO:
