Yeah, that's what I figured. Pilots can fly around a storm, but they can't fly over one.
Some unfortunatelty try to do it , it ends up badly most of the time.
In my years as ATC the one I remember best was a transatlantic bound 747 from a major European airline (now defunct) who decided against the 60-80NM dogleg that everyone else was doing to avoid a line of CBs above Belgium. He asked to climb to FL390 to keep its route , then when above dropped down 5 or 6 thousanfds feet right inside. His voice was shaken afterwards. The incident report must still be out somewhere.
2 weeks a go an A320 tried the same thing above Germany, with same results. 3xmayday, dropped 4000ft etc..
Rare events , sure ,but not unheard of.