I'll never forget coming through there in my TJ back in about 2006, top down, middle of summer, cruising at 65-70mph or whatever, crest the hill into Virginia, it flattens out, and within the next mile it goes from 90 degrees and sunny to suddenly there is steam everywhere and over an inch of hail on the interstate, cars sliding everywhere, very little control, and no way to stop. Fortunately traffic was light, and there was no way for anyone in the front to stop either, so we all slid through about a half mile or more of hail covering the interstate, and then right back to 90 degrees, sunny and clear. Wildest condition change I've ever seen in my entire life.