Fires start easily and spread at a fast rate. All fine dead fuels ignite readily and fires start easily from most causes. Unattended campfires are likely to escape. 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 difficult to control unless they are hit hard and fast while small.
Fires start very easily and spread at a very fast rate. Fires start easily from all causes, spread rapidly and intensify quickly. Spot fires are a constant danger. Fires burning in heavy fuels may quickly develop high-intensity characteristics, such as long-distance spotting and fire whirlwinds. Direct attack at the head of such fires is rarely possible after they have been burning more than a few minutes.