Updates to the Weather Information Management System (WIMS), FireFamilyPlus, and the National Fire Danger Rating System (NFDRS)

In 1975, the first computerized version of the manual 1972 National Fire Danger Rating System (NFDRS) was made available on a nationally accessible time-share computer system called AFFIRMS (Administrative and Forest Fire Information Retrieval and Management System). Three years later, the 1978 version of NFDRS was made available in AFFIRMS. In 1988 modifications were made to better assess how fire danger responds to drought in more humid climates with extensive live fuels. The 1988 updates were never made available in AFFIRMS because AFFIRMS was being retired.

In 1993, AFFIRMS was replaced by the Weather Information Management System (WIMS) as the processor of NFDRS information. The NFDRS in WIMS includes both the core 1978 version and the 1988 updates and is currently being used by most state and federal agencies. WIMS ingests hourly observations from approximately 2,500 Remote Automated Weather Stations (RAWS) across the United States, including Alaska, Hawaii, Guam, and Puerto Rico. Once each day, observations are manually checked for quality control and converted into an NFDR rating for the station. FireFamilyPlus, first released in 1999, is used to calculate historical NFDRS indices for development of climatological breakpoints and fire business thresholds for use in WIMS and fire danger rating operating plans.

Recently several significant updates have been made to both WIMS and FireFamilyPlus and others are in the works. This paper will highlight current changes in WIMS, including automated calculation of the State of the Weather flag (SOW) using solar radiation, use of unpublished “observation time” (“R”) RAWS weather data for forecasts in addition to the published (“O”) data, and implementation of the Nelson Dead Fuel moisture model to alleviate the requirement for users to manually enter state of the weather. The new FW13 format is also described. The FW13 format adds solar radiation, hourly wind gust and snow flag data to the WIMS export file.

FireFamilyPlus has been updated to align more closely with WIMS outputs. FireFamilyPlus now uses both published (“O”) and unpublished (“R”) observation time values to calculate NFDRS indices, automatically calculates a State of the Weather and wet flag using the logic in WIMS, and uses the WIMS snow flag in NFDR computations. Additional experimental variables have been added to FireFamilyPlus to calculate herbaceous and woody live fuel moistures from the Live Fuel Index. In addition, FireFamilyPlus now associates station IDs from NESDIS (National Environmental Satellite, Data, and Information Service) and WRCC (Western Region Climate Center) with WIMS station catalogs to expedite data imports from these systems.

During the 1980s, Deeming attempted to predict the probably future of NFDRS (1983, 1988), presenting his view of NFDRS in 2007. Several of those predictions have come to pass; others are now in progress. However, he writes, correctly, “I am confident that the fire-danger rating system of 2007 will look a great deal like the 1978 NFDRS.” This statement continues to hold true in 2013. Deeming mentions a number of topics related to fire danger forecasts, inclusion of external weather stations to improve spatial coverage, and better understanding of fuels and fuel moisture. Predictions of fire danger rating have advanced slightly beyond the 24-hour projections of the 1980s, but not within the WIMS framework. The 30-day NFDRS forecasts that Deeming anticipated are not available, primarily because of the lack of reliable weather forecast data. The Wildland Fire Assessment System (WFAS; www.wfas.net) provides national 7-day NFDRS forecasts using the National Digital Forecast Database. Rather, information such as that from the US Drought Monitor and forecasts from the climate Prediction Center is used to infer longer-term fire danger outlooks. As projected, weather data taken at non-RAWS weather stations are being integrated into WIMS to improve spatial representation of NFDRS, with demonstration data ingestion being completed for the states of Florida and North Carolina. There continues to be confusion about the selection and use of fuel models in and fire danger rating. New research into the twenty NFDRS fuel models should provide insight into the sensitivity of NFDRS to fuel model selection. Fuel moisture is an integral part of NFDRS, and experimental products are already improving estimates of live fuel moisture, accounting for changes in seasonality through use of standard weather inputs rather than manual observations of seasonality and curing. Promising new research is generating improved understanding of fire danger in organic fuels, which may soon be added as an experimental product. Research into an improved NFDRS is ramping up, and significant changes to NFDRS are expected in the new few years as experimental products provide improved estimates of fire danger.