The real good question is the correlation between hazardous weather, and airborne or ground based stormscope imagery.
I think the correlation is very good in one direction i.e. if the stormscope is showing a cell then you definitely do not want to go there.
But can you encounter structurally hazardous weather in the absence of
sferics activity?
I think you can, and therefore personally I climb above any IMC enroute. With a FL200 ceiling, this has always worked, so far. In Europe, this requires an IR because one is usually in CAS and VFR transits cannot be relied on.
However I have found that any clusters of sferics activity seem to always correlate with a lot of
radar return. OK if you have airborne radar
But not the other way round i.e. a strong radar return often does not have any sferics activity. Pilots claim such weather is safe to penetrate since turbulence is what causes the electrical activity. I don't buy that one.