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.
Report Abuse. Air pressure is the is pressure of air pressing down on the surface of the earth. High pressure is cold air falling to take the place of warm air rising. Low pressure is warm air rising leaving behind lower pressure when the air faling is still a bit warm.