After watching the supersonic flights on this YouTube video , I realized that it is possible to see condensation clouds forming right before the tip of the aircraft/rocket. I then asked myself where have I seen this before?
A quick visit to my SR 700 flight and I was able to see this phenomenon in my own flight!
At around 0:25 seconds in the video the cloud becomes visible for a short time then disappears as it goes beyond the sound barrier (i think).