We had to shut down Vortex do to heavy rains lots of times. Heavy rain used to produce a ghost train. We didn't want to have anyone getting stuck in the C's (Blocks) during heavy rain.
I also remember in '99 when the rain affected the senors at Express, also producing a ghost train, and causing setups. We had to walk people off the ride from the first lift, cause they couldn't get the ride going again.