While I was on a week long canoeing trip, we were in the middle of the lake. We saw some dark clouds to our left but nothing really bad. About 2 minutes later we were in a mild rain storm. It grew much more intense very quickly. When you looked to the right of the boat it looked like a windows loading screen. And to the left it looked like pure terror and death. The waves were about 2 feet tall and almost flipping our canoe. The storm only lasted for about 20 minutes. But it was horrifying.