Actions that are implemented to reduce or eliminate (mitigate) risks to persons, property or natural resources. These actions can be undertaken before and during a wildfire. Before a fire actions can include fuel treatments, creation of fuel breaks or barriers around critical or sensitive sites or resources, and vegetation modification and structural changes to increase the chance a structure will survive a wildfire with or without active protection (sometimes referred to as defensible space or the home ignition zone).

A back-up plan of action when actions described in the primary plan are no longer appropriate. Contingency actions are required to be taken when the result exceeds its intent. Actions are taken to return the project to its intended design.

A species with compact, resin-free, thick corky bark and less flammable foliage that has a relatively lower probability of being killed or scarred by a fire than a fire sensitive tree.

A species with thin bark or highly flammable foliage that has a relatively greater probability of being killed or scarred by a fire.

In WIMS, a group of weather stations.

An extreme rapid decomposition of a material in which the reaction is more than a sonic velocity, for example, high explosives.

A season when weather, fire danger, and number and distribution of fires are about average.

In fire weather, that area where two winds come together from opposite directions and are forced upwards often creating clouds and precipitation.

The ratio of live crown to tree height.

Process during which oxygen combines with another substance.