Fires spread rapidly and short-distance spotting is common. High-intensity burning may develop on slopes, or in concentrations of fine fuel. Fire may become serious and their control difficult, unless they are hit hard and fast while small. The color code is yellow. Extreme Fires under extreme conditions start quickly, spread furiously, and burn intensely.
All fires are potentially serious.
Development into high-intensity burning will usually be faster and occur from smaller fires than in the very high danger class. Direct attack is rarely possible, and may be dangerous, except immediately after ignition. Fires that develop headway in heavy slash or in conifer stands may be unmanageable while the extreme burning condition lasts. Under these conditions, the only effective and safe control action is on the flanks until the weather changes or the fuel supply lessens. The color code is red.