Haines Index

The Haines Index was developed by Donald Haines, a research meteorologist with the USDA Forest Service, in 1988. The Haines Index is an index that gives an indication about the potential for a fire "blow-up". A fire "blow-up" would lead to extreme fire behavior. The index uses the environmental lapse rate within a layer of air coupled with its moisture content to determine a Haines Index.

The Haines Index is dependent on elevation. Three combinations of atmospheric layers were used to construct the Haines Index (Low, Middle and High). For the purposes of our Fire Weather Forecasts, WSFO CAE will use the low-level Haines for the Coastal and Midlands zones, and the mid-level Haines for the Upstate zones.

The Haines Index is the sum of a stability term and a moisture term. The sum provides an indication of the potential for the rate of spread (ROS) of a fire on a given day. A Haines Index of 2-3= a very low ROS, 4= low ROS, 5=moderate ROS, and 6= high ROS.

Calculating Haines Index

Sum of two terms= Haines Index