...IMC....WX radar antenna 0 deg +1 deg... FL350,CB ahead with a vertical grow of 4000 ft/min. Small green dot ( ice does not give good return echos,right?) on the navigation display, "don't worries attitude"
( I have seen that )
BANG!
CAT, if associated with jet stream,does not come and go in short period of time. Did any other aircraft reported turbulence before or after CAL? My bet is on the table.