A mountain wind model for assisting fire management

Forestry organizations responsible for managing prescribed fire or controlling wildfire rely on weather forecasts of wind speed and wind direction for planning and allocation of resources. At the locations of fire sites in mountainous areas, winds are highly variable and may differ from winds at distant weather stations or from winds collected at safe sites just a few kilometers from fire lines. These uncertainties in winds can upset plans and place fire fighters in jeopardy. There exists a need for a simple, fast, operationally adaptable model to simulate wind flow in mountainous terrain.

A recursive rule-driven “mountain wind model” (MWM) replaces terrain with a “pressure potential” equation to simulate windfields in complex terrain. Windfields are developed for a 100m deep layer draped over terrain. The MWM is demonstrated with flow around a simple obstacle (Stone Mountain, GA), flow over a ridgeline in the central Appalachians, and for the Esperanza fire in California on 26 October 2006. The MWM placed wind direction in line with the direction of movement of the “head” of the fire.