How to form a virtual thunderstorm outside your windowpane? you're walking into the haunted mansion at disneyland and you go through...

you're walking into the haunted mansion at disneyland and you go through the elevator. when you come out of the elevator you're in a corridor next to portraits on one side and a couple windows on the left. outside within seems to be a huge thunderstorm going on outside.

i wanted to trademark something like this for one of the windows surrounded by my room. does anyone know how they get that effect? i dont want to use any water, merely lights and sound. any ideas?
Answers:    use a sprinkler on the run out of a hose fixed to the up stars window, get a flexible sheet of steel, consequently get someone to go outside and flex the sheet of steel and turn the hose on at duplicate time, you could even get some one to turn a flash light on and stale for more of an effect.
Sprinkler head and a bad CD of Hanson?