Fire Potential / Fire Danger Maps
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Haines Index
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US48 | AK
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US48
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Haines (1988) developed the Lower
Atmosphere Stability Index, or Haines Index, for fire weather use.
It is used to indicate the potential for wildfire growth by
measuring the stability and dryness of the air over a fire. It is
calculated by combining the stability and moisture content of the
lower atmosphere into a number that correlates well with large fire
growth. The stability term is determined by the temperature
difference between two atmospheric layers; the moisture term is
determined by the temperature and dew point difference. This index
has been shown to be correlated with large fire growth on
initiating and existing fires where surface winds do not dominate
fire behavior.
Haines
Index is computed from the morning (12Z) soundings from RAOB
stations across North America.
The Haines Index can range between 2 and 6. The drier and more
unstable the lower atmosphere is, the higher the index.
- 2 : Very Low Potential -- (Moist Stable Lower Atmosphere)
- 3 : Very Low Potential
- 4 : Low Potential
- 5 : Moderate Potential
- 6 : High Potential ------ (Dry Unstable Lower Atmosphere)