robvia is right. If there is no lightning within 5 miles they continue to run the coasters. We went Weds. after hearing Tornado warnings on the early morning news. My kids rode the front seat of DD in the rain and my daughter was nearly in tears from the pain. I imagine it would be similar to riding a motorcycle in the rain.
What really got me hot was when they got off the coaster I gave my daughter a poncho. Well, not just any poncho, but one of the ponchos Universal sold when they first opened. They were yellow with the logo in blue on the back and smaller on the left chest. She managed to rip it to shreds!
So much for my collector's item!