Make a tornado tube.  All you need is a connector (I bought mine at Oriental Trading), http://www.orientaltrading.com/api/search?Ntt=tornado+tube , and two empty plastic soda bottles.  Add some water, some food coloring, and glitter if you like.  This is fascinating for kids and even adults!  Learn about how tornadoes form by watching a You Tube or check out a book from the library.  Research centripetal force, water spouts, whirlpools, eddies, the Coriolis effect, and a vortex.  Even though the water is in a bottle, this hands on activity will provide “cool” water fun.