Thanks for the quick response, LJ. These are new turbines that were just installed a couple of months ago as part of a complete reroofing project. I've actually gone up during the rain and found that the dripping is coming down the shaft and the sides of the turbine from rain that has hit the inside of the turbine. There is no moisture around the base of the turbine and no evidence of moisture on the underside or edges of the decking where the opening is cut.
This is only happening when there is a really strong wind driving the rain.
Based on these extended facts, am still in "not normal" mode. Well, actually some folks would probably say that I've been in that mode for quite a long time, but I'm actually referring to the roof!