As the fire s intensity increases, the air above it becomes more and more heated. Nearby plants dry out. Steep terrain will let a fire burn quickly uphill. Heat concentrates on the hillside as it rises off the burning brush or trees. The drying and heating of the unburned vegetation happens quicker than on a flat surface.
Fire spreads in three ways.
Ground fires creep slowly through organic debris on the ground. Surface fires involve surface litter, shrubs, and small trees. Crown fires roar from tree top to tree top. Crown fires move the quickest of all fires if there is sufficient fuel and can reach moving speeds as high as 65 mph or more. Firestorms need and consume great amounts of oxygen.