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Measures of Stability


Major Factors

Primary Utility


Davis Stability Index

Lapse rate

Basic measure of stability

Southeast US

Ventilation Index

Mixing height and transport wind

Smoke dispersion

 United States

Haines (Lower Atmospheric Stability) Index

Lapse rate and relative humidity

Large fire growth potential

United States

Pasquill Stability Index

Solar radiation, cloud cover and surface wind speed (surface based stability)

Smoke dispersion


Lavdas Atmospheric Dispersion Index

Pasquill, mixing height, transport wind

Smoke dispersion and fire growth potential.


Lower Atmospheric Stability (Haines) Index

The Lower Atmospheric Severity Index (commonly known as the Haines Index) was developed during the 1980s as a fire weather tool to estimate the effect of atmospheric dryness and stability on the growth potential of a wildfire. The goal was to identify typical combinations of humidity and stability and contrast them with combinations of stability and humidity prevalent during problem fire outbreaks. Always reference local Climatology (below).
Haines Index Reference

Haines Index Climatology