The day began sunny and became warmer than expected. At about 3 p.m., a thunderstorm blew through, and the temperature dropped 18 degrees. Then the sun came out, so I walked to the lake, where I ate a late lunch. Then it got cloudy, and I sat there watching lightning streaks come out of the sky down to the horizon behind the buildings in South Chicago across from Promontory Point. It was lovely. The thunder came. Then I heard kids down toward the beach screaming and running, and I watched a wall of rain move through the air north from the beach toward me until I was hit. I heard it when it was about 20 feet off. It was fascinating to watch the wall move, the people flee, and the drops hit the water.