Waldo, there's more interesting side effects to thunderstorms than lightning (although the cost of a compass swing, ADF fix and minor/skin paint damage, plus the aircraft down time are sufficient reason to avoid even a lightning strike).
Have a look at
http://afsafety.af.mil/magazine/htdo...98/tstorms.htm
I'd hold clear until the storm, with it's associated potentially severe dangers, had passed.
I
would have enough fuel for such messing around, because I'd have seen the thunderstorms on the TAFs and added destination holding fuel. 30 mins minimum also covers any need for dog-legs during the flight. Yes, I
really do do that in practice, I'm not just saying it.
In other words, I'd have covered the situation in the briefing room before departure.