What is the effect of wind on ROS when estimating fire behavior?

• A. Wind has no effect on ROS
• B. Wind reduces ROS by dispersing heat
• C. Wind can increase ROS by supplying more oxygen and promoting heat transfer
• D. Wind only affects spotting and not ROS

Answer: (C)

Wind changes the balance of heat and oxygen at the fire front, making the fire spread faster. As wind increases, it brings more oxygen into the combustion zone and helps remove heat and gases from the flames. This boosts convective heat transfer to unburned fuels ahead of the front, preheating and sometimes drying them, which makes ignition happen sooner. With fuels preheated and ignited more readily, the flame front advances more quickly, raising the rate of spread. Embers and spotting can also contribute to overall growth, but the main effect on ROS comes from the increased oxygen supply and enhanced heat transfer that push the front forward.