Saw it once in the tin triangle letting down into Finningley at night through the slot in the airway - can't remember what height the slot was now but about 15 to 20k feet I think. We were not aware of any cb activity but since you couldn't see much out of the aircraft that may be an unreliable statement.
We had been told about St Elmo's fire but no-one told us it was associated with danger so we thought it looked very pretty. It just outlined the windscreen but I do not recall what colour.
ACW