This study focuses on evaluating two stability indices commonly used in fire weather with regard to their predictive ability for the potential for large wildfires. The Haines Index is a common component in fire weather forecasts and provides an indication of the potential for explosive growth of wildfires by examining the stability of the lower atmosphere and the dryness of upper levels of the atmosphere. The Atmospheric Dispersion Index (ADI), designed to estimate the atmosphere’s ability to disperse smoke from a prescribed fire, is used among Florida’s wildfire community to indicate a potential for extreme wildfire behavior.

Using data from May and June of 1998, when Florida experienced one of its most severe wildfire seasons on record, the relationship between both the Haines Index and the Atmospheric Dispersion Index to daily area burned is examined. The Haines Index showed a significant correlation to area burned while the Atmospheric Dispersion Index did not. However, examination of the two components of the Atmospheric Dispersion Index did reveal information useful in assessing large fire potential. A hypothetical optimal combination of these two components displayed the best potential to predict severe fire days.