Climatology of fire danger from the North American Regional Reanalysis dataset

Wildland fire danger is the sum of constant and variable danger factors affecting the inception, spread and resistance to control, and subsequent fire damage; often expressed as a relative number indicating the severity of wildland fire danger. Fire danger is an integral part of fire management operations and planning, and is indicated both by observations and predictions. Observed fire danger is typically calculated from weather station observations recorded at Remote Automated Weather Stations (RAWS) or sometimes other network data. Experimental predictions of fire danger have been developed for short- and medium-range forecasts and seasonal outlooks. For these predictions, it is desirable to have a gridded climatology of fire danger to provide anomaly forecasts. It is also desirable to have a gridded climatology for analyses to assess seasonal cycles, inter- and intra-annual variability, and extremes and trend among other characteristics. This presentation describes the development of a daily fire danger index – energy release component (ERC) – climatology utilizing 3-hourly output from the 32-km gridded North American Regional Reanalysis (NARR) dataset for the period 1980-2005. ERC is the computed total heat released per unit area within the flaming front at the head of an advancing fire, and is a heavily utilized index in fire management. Methodology and seasonality characteristics of ERC are given in this presentation, along with a discussion of potential benefits of this newly derived dataset. The development of this large fire danger dataset represents the first application of NARR in an applied climate context for wildland fire research and management decision-support.