Wednesday, 19 November 2003: 4:15 PM
National standardized energy release component (ERC) forecasts
Currently, the National Fire Danger Rating System (NFDRS) produces a daily Energy Release Component (ERC) index. The ERC index is directly related to the total available energy (BTUs) per unit area (in square feet) within the flaming front at the head of a fire. It essentially indicates how hot a fire could burn and is considered one of the best fire danger components for indicating the effects of intermediate to long-term drying (www.fs.fed.us/r5/fire/intel/ncsc/pred_serv/definitions/erc.shtml). ERC is highly sensitive to the NFDRS fuel model (e.g. ponderosa pine, slash, sagebrush). As a result, given the same atmospheric inputs, an ERC value in a forested area might be quite different than an ERC value in a neighboring desert shrub area. The varying fuel models pose difficulty in any cross-regional comparison of ERC, especially if it is desired to assess the magnitude of the value in the context of ERC climatology. Therefore, using a constant fuel model (in this case - G ? short needle pine (heavy dead)), national standardized ERC values based upon historical ERC averages and standard deviations are computed operationally from National Weather Service Gridded Forecast System (GFS) output. The primary value of this product is to allow the National Interagency Coordination Center to assess ERC daily standard deviations across the U.S. on an operational basis. This paper describes the development of the ERC climatology, and the application of GFS model output in the production of daily, standardized ERC forecasts out to 15 days.