An Hourly Operational Fire Danger Monitoring Tool

Fire danger indices produced by the National Fire Danger Rating System have been used for several decades to monitor local conditions and potential quality of fires upon ignition. Operational input parameters have typically come from once-a-day observations (e.g., 1300 local time) and placed into categories of severity based upon climatological percentiles for that time of day. Often, these observations would come from data observed from the Remote Automated Weather System (RAWS) network that provide hourly information. Therefore, hourly fire danger monitoring is possible that would provide additional information on diurnal changes in fire danger. Since the late 1990s, California has been utilizing an hourly, operational fire danger-monitoring tool based upon RAWS observations within designated Fire Danger Rating Areas (FDRAs). Recently, this decision support tool has been augmented to incorporate algorithms more objectively derived based upon solar radiation and precipitation to eliminate the need of subjectively determined input parameters such as state of the weather and the state of vegetative greenness. This talk will present the work done in California for hourly fire danger monitoring for potential applications in other regions of the United States.