Fire Weather Index
Overall potential fire intensity derived from Initial Spread Index and Buildup Index. FireRadar's existing Fire Danger page remains the canonical FWI owner.
Fine Fuel Moisture Code
FFMC represents moisture in fine dead surface fuels such as litter and small twigs that can dry and re-wet quickly. It is one of the three fuel-moisture codes that feed the Canadian Fire Weather Index System.
Duff Moisture Code
DMC represents moisture in loosely compacted organic layers of moderate depth. It responds more slowly than FFMC and contributes to estimates of fuel available for combustion.
Drought Code
DC represents the moisture content of deep, compact organic layers and reflects longer-term drying. It changes relatively slowly and is one of the FWI System's three fuel-moisture codes.
Initial Spread Index
ISI combines wind speed with Fine Fuel Moisture Code to provide a relative indication of how quickly a fire may spread immediately after ignition in the FWI System's standard fuel context.
Buildup Index
BUI combines Duff Moisture Code and Drought Code to provide a relative indication of the total amount of fuel available for combustion in the FWI System's standard fuel complex.
Daily Severity Rating
DSR is derived from Fire Weather Index and is intended to reflect the expected effort required for fire suppression on a daily basis. It emphasizes the higher end of FWI values.
How the Fire Weather Index System fits together
Tracks drying from fast-changing fine surface fuels through deeper organic layers.
Uses fuel moisture and wind to describe initial spread potential and available fuel.
Combines the preceding components into potential fire intensity and daily control-difficulty guidance.
These are not incident predictions
CFFDRS fire-weather components do not prove that a wildfire will start, identify the cause of an incident, forecast an evacuation, or determine whether a road or community is safe. Use the responsible wildfire and emergency authorities for operational decisions.