Expected relative ember load per pixel, for a given pixel, based on surface and canopy fuel characteristics, climate, and topography within the pixel. Units are relative number of embers. ELI can be used to identify where on the landscape hardening buildings may be needed to resist ignition and the priority for doing so according to the likelihood of the area being visited by fire. ELI is not simply the multiplication of conditional ember load and burn probability. Rather, BP is incorporated into calculations of the ember production prior to the distribution of embers across the landscape to determine ember load. This layer, based primarily on landscape conditions at the beginning of the 2020 fire season, was aggregated from the original 30m resolution to 90m by mean.

WildEST – Wildfire Exposure Simulation Tool is a scripted geospatial process used for simulating potential fire behavior characteristics that addresses two shortcomings of current methods. WildEST performs multiple deterministic simulations under a range of weather types (wind speed, wind direction, fuel moisture content). Rather than weighting results solely according to the temporal relative frequencies of the weather scenarios, the WildEST process integrates results by weighting them according to their weather type probabilities (WTP), which appropriately weights high-spread conditions into the calculations.

Most WildEST results apply to the head of the fire. For fire-effects calculations, WildEST also generates flame-length probability rasters that incorporate non-heading spread directions, for which fire intensity is considerably lower than at the head of the fire. These “NVC” FLPs are analogous to FLP rasters produced by FSim.

WildEST was run for the CAL fuelscape at 30-m resolution using gridded historical California weather data provided by CALFIRE. Based on heading-only fire behavior. Please reference the CAL report for more detailed information. Original raster resolution is 30m. Data finalized 1/31/2021.