Dead Fuel Moisture and the Wildfire Extinction Threshold

Wildland fire spread is not just a function of wind and slope — it hinges on how much water is locked inside the dead fuel itself. This simulator renders a 3D fuel bed of grass and litter, each cell carrying its own dead-fuel moisture content, and propagates an ignited fire using Rothermel's moisture damping coefficient η_M, the real function fire behavior analysts use to scale spread rate against moisture. Push the fuel moisture slider up toward the ~30% moisture-of-extinction threshold for fine fuels and watch a roaring head fire choke down to nothing as evaporative losses overwhelm the available heat, while wind speed and slope bias the front toward realistic downwind, upslope acceleration.