Keep flying w/o fear, but watch out for those storms -- people have been struck by lightning with blue sky overhead.
They also have a WICKED wind front. Was in a shorter-than-planned landing in a full-scale Cessna 172 from one of these thundercells. On the ground prior the sky looked grey, but not bad, and once we got above the treeline we couldn't get back down fast enough -- until we got down too fast. These winds will think nothing of A/C of *ANY* size.