Bigflesh- if I can understand you correctly, I'd say the following:
Not 60,000'. More likely roundabout 35,000'.
Radar gives no visible effects ahead of the aircraft.
Most likely explanation is that the aeroplanes are above the cloud layer, and you are seeing the shadow of the contrails* cast ahead of the aeroplanes onto the top of a thin layer of cloud.
A lot of people here call these 'chemical trails'. Don't buy anything off them!