What winds are responsible for the largest fatality and structural loss fires in United States history?

What winds are responsible for the largest fatality and structural loss fires in United States history?

• A. Foehn winds
• B. Santa Ana winds
• C. Chinook winds
• D. Mistral winds

Answer: (A)

Winds that drive extreme fire behavior are hot, dry, downslope flows that intensely preheat and dry fuels, boost flame lengths, and push the fire sideways and ahead of the main fire front. In the United States, the winds most closely linked to the largest fatality and structural loss wildfires are Santa Ana winds. These winds originate inland, funnel through mountain passes, and roar toward the coast, warming as they descend. They bring very low humidity and high wind speeds, which moisurize and dry fuels, enable rapid spread, and create dangerous spotting with embers carried long distances. That combination of dryness, heat, and strong, unpredictable gusts is what makes Santa Ana events so capable of producing catastrophic fires. Foehn winds are a similar downsloping, drying wind, but they occur in Europe and other regions and are not the pattern most often implicated in the United States’ historically worst fires. Chinook winds are another example of warm, downslope winds in the western U.S., and they can contribute to rapid fire growth as well, but the classic fires with the greatest loss in U.S. history are most commonly associated with Santa Ana events. Mistral winds are a regional European phenomenon and not linked to the U.S. wildfire history.

Winds that drive extreme fire behavior are hot, dry, downslope flows that intensely preheat and dry fuels, boost flame lengths, and push the fire sideways and ahead of the main fire front. In the United States, the winds most closely linked to the largest fatality and structural loss wildfires are Santa Ana winds. These winds originate inland, funnel through mountain passes, and roar toward the coast, warming as they descend. They bring very low humidity and high wind speeds, which moisurize and dry fuels, enable rapid spread, and create dangerous spotting with embers carried long distances. That combination of dryness, heat, and strong, unpredictable gusts is what makes Santa Ana events so capable of producing catastrophic fires.

Foehn winds are a similar downsloping, drying wind, but they occur in Europe and other regions and are not the pattern most often implicated in the United States’ historically worst fires. Chinook winds are another example of warm, downslope winds in the western U.S., and they can contribute to rapid fire growth as well, but the classic fires with the greatest loss in U.S. history are most commonly associated with Santa Ana events. Mistral winds are a regional European phenomenon and not linked to the U.S. wildfire history.