I was walking my dogs around the block around 10:15 p.m. when I reached a corner facing north. Ahead and slightly to my right, I noticed a plane-like pair of red/blue alternately blinking lights to the north in the direction of Lake Erie, where a thunderstorm was visible over the lake. Cleveland Hopkins Airport is not too far to the east from here, so I am used to seeing planes each night, but this was clearly not a plane. These lights dropped down and then flew up to about 40 degrees or so and stopped, hovering. I watched for several minutes and then decided that this was odd enough to call my wife, who was inside our house about half a block away. She joined me at the corner and observed the rest of the event with me. At one point the red light appeared to switch off; now there was just a bluish-green light flashing. The object began moving again, first down and then to the left. Then it moved up and started to grow fainter, as if it were flying out over the lake. The light disappeared; we assumed it had flown into one of the storm clouds over the lake. It reappeared briefly, flashing red and blue as it had at the beginning; it flew back into the cloud and was gone from sight for 10 seconds or so. Suddenly it reappeared off to the right, and the blue light shut off and the red light began blinking rapidly. Finally, the object dropped straight down below the tree line and disappeared from view.As a MUFON member, I am always scanning the night sky, and I have seen many planes and, occasionally, satellites. I have never seen anything like this. I can't discount the possibility that the lights were attached to a drone, but if so, it was moving erratically, hovering for long periods of time, and displaying a changing light pattern near a strong thunderstorm. Lightning did flash behind the object multiple times during the sighting, but I couldn't see any shape silhouetted against the bright light.I was not scared by the encounter, and the possibility that it might be a helicopter (I don't think so) or drone kept me from getting too excited, but I honestly don't know what this was. My wife was somewhat concerned because her first reaction was that this might be a plane or aircraft in distress. The dogs did not react in any way (aside from one yipping when the lights made a sudden maneuver and I stepped on his foot!)