Tesmond D. Hurd 1
1 Fire, Weather & Avalanche Center, La Grande, Oregon 97850
SUMMARY: The FWAC fire model uses a proprietary algorithm of meteorological (weather) diagnostic variables to determine with the likelihood of a wildfire growing into a large fire. The model is based on an hourly period for individual wildfires, calculated at the time you view the information. To learn more about the fire model, see the full paper below.
ABSTRACT: Fire Weather Indexes (FWI) have been utilized for nearly 40 years to assist meteorologists and wildland fire managers with improving wildfire ignition and behavioral predictions. These models, such as the Haines Index and National Fire Danger Rating System, have become standard in the United States with only minor modifications since their inception. In this article, a new, more simplistic FWI is introduced using a three-color scale to convey likelihood, or severity, of a wildfire's growth potential. Unlike the Haines Index, this new model incorporates current and forecasted weather conditions to determine wildfire growth potential. The new fire model incorporates the most important meteorological deterministic variables nearest to a fire to reduce spatial variability concerns—a large disadvantage with traditional FWIs. Because the public is typically less informed about the purpose and use of the Haines Index, that necessity was eliminated in the new model. The colors used in this new model will quickly communicate severity without a user having to actually understand how the model works. The most important advantage the new model possesses, compared to other FWIs, is its simple three-color scale consisting of green, yellow, and red; allowing a user of the model to quickly identify the wildfire's growth potential.