Catawba rhododendron bushes can reach a height of 6'-8' with a spread of 4'-6'. Displays are most effective when rhododendron bushes are massed together. These are poisonous plants -- do not allow children to ingest any of the azaleas or rhododendrons.
Best Answer: Tornadoes are caused by winds. When a tornado forms the wind pressure around the tornado drops and that's what you see on the barometer, the pressure goes down.
Colliding air masses within tornado alley make for exceptional conditions that allow for vigorously rising air, which is essential for thunderstorms. Storms in the Great Plains regularly reach 10 miles (16 kilometers) into the sky because of these conditions: 1  Winds pushing disparate air masses converge in tornado alley. 2  Colliding air, known as fronts, have nowhere to go, therefore they rise.