LAPS Fire weather index (image). Contour overlays of wind and surface relative humidity are also shown.

LAPS fire weather index is driven mainly by the surface fields of current humidity, wind, and temperature. RH and wind have the most weight with temperature having a lesser weight for this index that ranges from 0 to 20. Snow cover, elevation, and land fraction are given secondary consideration. High elevations, assumed to be above the treeline, are given a lower maximum value of 10. This index was developed primarily by Matt Kelsch of FSL.