Additional details about Fire Danger Forecast data products and research efforts.
The project maintains and operates an automated, daily production process which generates a suite of digital map products related to the forecasting of fire ignition and subsequent spread potential. These Fire Danger forecast products are made available for display and distribution through this website.
Wildland Fire Potential Index (WFPI)
WFPI is a moisture and wind-based vegetation flammability indicator. It is a function of current vegetation greenness as a proportion of maximum greenness, current 10-h dead fuel moisture, wind speed, rain, and dry bulb temperature. Flammability is highest when the vegetation is mostly or completely cured, 10-h dead fuel moisture is low, and the wind speed is high. Conversely, WFPI is lowest when the living vegetation is near fully green, the dead fuel moisture is high, and the wind speed is low.
WFPI-based Large Fire Probability (WLFP)
WLFP represents the probability of a large fire (>500 acres) occurring for a specific time and location. The statistical model used to create these maps is based on WFPI, location as a surrogate for fuel availability, fuel type, and the day of year which accounts for seasonal patterns in fire activity.
WFPI-based Fire Spread Probability (WFSP)
Probability that an existing one-acre fire will spread and burn more than 500 acres. Seasonal and location differences in fire risk are assumed to be mainly due to the variables used in calculating the WFPI.
Fire Danger Base Vegetation Indices
Fire Danger Forecast product generation relies on two vegetation indices, which are updated weekly, Normalized Difference Vegetation Index (NDVI) and Relative Greenness (RG). NDVI quantifies vegetation by measuring the difference between the near-infrared signature (which vegetation strongly reflects) and the red signature (which vegetation absorbs) of a particular pixel. RG indicates how green a pixel is relative to the range of historical NDVI observations for that same pixel.
Research Topic: A Comparison of Fire Potential Index Rasters Derived from AVHRR and MODIS Data
Historically, Fire Danger products have been produced from Advanced Very High-Resolution Radiometer (AVHRR) data, with the latest such instrument aboard NOAA-15. More recently, these products are derived from similar data obtained from the Moderate Resolution Imaging Spectrometer (MODIS) aboard the Aqua satellite. The motivation of this study is to determine the comparability between the same Fire Danger products generated with the two differing imagery sources.
Research Topic: Accuracy Assessment of WFPI, WLFP, and WFSP
An assessment of historical fire records to determine the skill and accuracy of the WFPI and WFPI-based large fire probability and fire spread probability products. Results comparing observed data vs. estimated data indicate that these products can provide value for fire risk monitoring.
Legacy Fire Danger Forecast Products
Over the course of the Project, Fire Danger Forecasting has made updates to the methodologies which derive the development of Fire Danger data products. These changes have all used the legacy Fire Danger Forecasting methodology as the foundational start point.