Fill one two-liter plastic bottle all the way to the top with water. Next, add a five drops of blue food coloring.
Sit the bottle on a flat surface. Pick up the second bottle, and turn it upside down. Place the opening of the bottle on top of the opening of the first bottle. Hold it firmly in place, and wrap rubber hose repair tape around the neck of the bottles. Wrap back and forth, so the tape holds the openings of the two bottles tightly together. This keeps the water in the bottle when you turn them. If you prefer, purchase a Tornado Tube from any school supply store. Screw one two-liter bottle into each end of the Tornado Tube.
Turn the bottle over, and the water flows down through the bottle openings. As it flows into the empty bottle, it creates a vortex swirl that simulates how a hurricane looks. The water moves in the same way as a hurricane as it is forming. Let the water run through the bottle, and turn the bottle back over. The vortex forms again. Step a few feet away from the bottles, so you get a better view of the hurricane vortex as it spins into a hurricane's cone shape.
Try experimenting with the bottles, and see if you change the swirl of the vortex. Try shaking the bottle before you turn it over. Try shaking it as you turn it. This shows how waves and water currents alter the vortex of a hurricane. Sit the bottles in a sunny spot so the water gets hot. Then turn the bottle over, and see how heat alters the vortex. Sit the bottles in a cooler full of ice or a refrigerator, and see how cold air changes the vortex.