Accurate predictions of how weather may affect a wildfire’s behavior are
needed to protect crews on the line and efficiently allocate firefighting
resources. Since 1988, fire meteorologists have used a tool called the Haines
Index to predict days when the weather will exacerbate a wildfire.
Although the Haines Index is widely believed to have value, it never received rigorous testing on the line. Even Don Haines, the U.S. Forest Service meteorologist who developed the index, has said the Haines Index needs further refinement. Recognizing that a new fire weather prediction tool was needed, a team composed of meteorologists with the U.S. Forest Service and St. Cloud State University developed the Hot-DryWindy Index. The index is based upon the three weather conditions—hot, dry, and windy—that significantly affect a wildfire’s behavior.
U.S. Forest Service Pacific Northwest Research Station
May 2020 | Issue 227 Science Findings