In a scenario with high winds and gentle slope, what is the expected ROS trend?

• A. ROS generally increases with wind; slope effects are smaller on gentle slopes, so ROS tends to rise but not dramatically due to slope alone
• B. ROS decreases with wind
• C. ROS unaffected by wind
• D. ROS generally decreases with slope on gentle slopes

Answer: (A)

Wind is the primary driver of rate of spread. In high winds, flames are pushed ahead, the flame tilt increases preheating of fuels, and convective heat transfer is enhanced, all of which raise how quickly the fire front advances.

On a gentle slope, the slope-driven acceleration is present but much less pronounced than on steeper terrain. So while slope contributes to faster spread, its impact is limited when the slope is mild, meaning it won’t cause a dramatic jump by itself.

Putting those factors together, the expected trend is that the rate of spread rises with wind, and the gentle slope won’t amplify that rise dramatically. So you see an overall increase in ROS due to the wind, with only a modest additional boost from the slope.