We had a thunder storm on Opening Day a few years ago that rolled in with some serious lightning, thunder, and marble-sized hail. The turkeys were gobbling at the start of thunder, but when they shut up right before the severe stuff hit, I decided to make a dash for the cabin. I got there just as the bottom fell out and my buddy who was about 400 yards behind me got drenched. We eased back out about two hours later as the storm was slacking off. Within minutes, there were hens around my buddy (in an open area) while I saw nothing (in the woods) until the sun broke out almost two hours later. Neither of us had any shooters working, but we each saw plenty of birds.
I like the light drizzle best. The turkeys don't seem to care much about a light to moderate rain. If the rain gets too heavy, they either fly back up, or go to an open area.
Luck Counts, good or bad