The fire danger forecast module of GWIS provides forecast maps from 1 to 9 days of fire danger levels. Numerical weather predictions are used to compute the (Van Wagner and Pickett, 1985). In 2019, due to the interest of countries to compare the performance of the FWI with other relevant fire danger indices, the Australian McArthur Forest Fire Danger Index (MARK-5), the Keetch-Byram Drought Index (KBDI) and the National Fire Danger Rating System (NFDRS) have been made available through GWIS.
GWIS operates using meteorological forecast data received daily from the European Centre for Medium-Range Weather Forecast (ECMWF).
Fire danger is mapped in 6 classes (very low, low, medium, high, very high and extreme) with a spatial resolution of about 8 km (ECMWF data). At the moment, the fire danger classes are the same for all countries and maps show a harmonized view of the spatial distribution of fire danger level.
However, given the different climatic conditions at the global level, GWIS publishes two indicators that provide information on the local/temporal variability of the FWI values as compared to a historical time series of approximately 30 years. Those products are the ranking, which provides percentiles of occurrence of the values, and the anomaly, computed as a standard deviation from the historical mean values. These indices are available in the "index" pull-down menu.
The following are the FWI values used as thresholds of the fire danger classes in the map:
|Fire Danger Classes||FWI ranges
(upper bound excluded)
|Very low||< 5.2|
|Low||5.2 - 11.2|
|Moderate||11.2 - 21.3|
|High||21.3 - 38.0|
|Very high||38.0 - 50.0|
Van Wagner, C.E., Pickett, T.L. 1985, Equations and FORTRAN program for the Canadian Forest Fire Weather Index System. Can. For. Serv., For. Rech. Rep. 33 18 p.