sadly, I have been caught out in scary weather on a couple occasions during rides.
One memorable one was in the middle of the '08 Old Dominion 100. The ride is in the virginia mountains in june, so notorious for hot/humid weather. We got lucky that day, as it had been overcast most of the day, keeping the temps down. But a massive front came thru just before dinnertime that brought torrential rain, lightning, thunder, and hail.
I can remember thinking that I sure as heck didn't wanna stay on the tops of the ridges with the lightning hitting trees all around, but the lower ground was flooding rapidly. The trail was a raging torrent. The tree cover stopped the hail from actually hitting hard enough to hurt, but made the footing that wasn't water-covered treacherous.
The storm lasted maybe 20 min, but it felt like 3 days. Dreams never batted an eye, bless her heart. She just kept going up the trail like nothing out of the ordinary was happening. Thank goodness for horses with brains!
Another fun weather-related one was last year's Rabbit Run 50 miler, which is in the pine barrens of new jersey in march. We had a lot of snowfall all winter, then something like 8 inches of rain the week before the ride. I took this vid on trail during the competition: anybody for a swim?