I have seen threads in the road forum on riding in the rain but don't recall seeing one in the 50+. I wonder if as you get older your tolerance for bad weather diminishes. I bring this up because yesterday I was caught in a monsoon in the last 3-4 miles of my ride. In general I will not go out and start a ride if it is raining but if I am out and already wet with sweat then I generally will stay out unless it is blowing sideways or there is a lot of lightening. I find that I seem to ride more in a zone when it is raining, the rain seems to put you in a little cocoon and everything around you disapears. Other than slowing heavily in corners I generally don't slow down and actually tend to ride faster.
How about you?