Not only intense lightning, but sometimes large hail in the upper part of the eyewall. It doesn’t make it to the ground though as it’s too warm and the updraft too strong, but hurricane hunters have been pummeled by it. If that is happening the storm is rapidly intensifying. Also, on the ground/water, you get tornado vortices rotating in the eyewall.
I LOVED my meteorology class. It was an elective, and my degree wasn’t meteorology, but I was fascinated.
Andrew in 1992 baffled the experts. The worst damage wasn’t in the right front quadrant, but rather in the southwest of the storm! They STILL haven’t figured it out. They think downdrafts and/or intense mesovortices caused the extreme total destruction at Naranja. Also, mesovortices have been seen crossing the eye, meaning the eye may not always be calm.
So much left to learn about these mysterious forces of nature.