Aiming for Van Nuys CA., in a Clay Lacy LearJet [1983] overhead Pueblo at night and looking down[and up] on streets of Cu with plenty of sparking to earth [and between clouds] when all of a sudden, out of the rounded top of one Cu, just below our level [around FL420] and climbing, a mult-threaded bolt spread over the top of the head [in about five threads] of the Cu and then shot back inside a little lower and a fraction of a second later [like a coronet] and lit up the base for a good few seconds. Electric blue at height and warm and mistily orange below. Badly described but sensationally beautiful to look at. Etched on my brain until I keel over. Even Clay was surprised. Never seen anything like it since.
Aviate1138