Fortunately I've been able to avoid that. However I did spend two of our worst rain seasons riding my GL1000 to work and back. The rain was 'falling' horizontally' and visibility was near non-existant. Somewhat mild compared to what others experience but I didn't like it one bit. It had a Vetter Windjammer so that was a big help but still no joy.riding in the rain on the ST is a dream!
I did have to ride my old CL77 (305 Scrambler) in the rain for a few days. The rainfall itself wasn't as bad as the later incident but I wasn't protected at all and the bike was much slower.