Test
Haines Index: What is it?

The Haines Index is a common metric for measuring the potential contribution of dry and unstable air to the development of large or erratic wildfires. Generally a Haines Index of less than 4 indicates a very low potential for an existing fire to become large or erratic, 4 suggests low potential, 5 suggests medium potential and 6 indicates high potential. It is derived soley from the summed influence of the lapse rate and dew-point depression components of the lower atmosphere. The exact vertical level depends on the surface elevation. The Haines Index methodology is described in more detail below.

The Haines Index consists of summing both the Lapse Rate and Dew Point Depression subcomponents.

Surface elevations less than 200 meters:

Lapse Rate Subcomponent:
• If the 950 hPa to 850 hPa lapse rate is less than 4 Kelvin, a value of 1 is assigned.
• If the lapse rate is between 4 Kelvin and 8 Kelvin, a value of 2 is assinged.
• If the lapse rate is greater than 8 Kelvin, a value of 3 is assigned.

Dew point Depression Subcomponent:
• If the 850 hPa dew point depression is less than 6 Kelvin, a value of 1 is assigned.
• If the dew point depression is between 6 Kelvin and 10 Kelvin, a value of 2 is assinged.
• If the dew point depression is greater than 10 Kelvin, a value of 3 is assigned.

Surface elevations between 200 meters and 1000 meters:

Lapse Rate Subcomponent:
• If the 850 hPa to 700 hPa lapse rate is less than 6 Kelvin, a value of 1 is assigned.
• If the lapse rate is between 6 Kelvin and 11 Kelvin, a value of 2 is assinged.
• If the lapse rate is greater than 11 Kelvin, a value of 3 is assigned.

Dew point Depression Subcomponent:
• If the 850 hPa dew point depression is less than 6 Kelvin, a value of 1 is assigned.
• If the dew point depression is between 6 Kelvin and 13 Kelvin, a value of 2 is assinged.
• If the dew point depression is greater than 13 Kelvin, a value of 3 is assigned.

Surface elevations greater than 1000 meters:

Lapse Rate Subcomponent:
• If the 700 hPa to 500 hPa lapse rate is less than 18 Kelvin, a value of 1 is assigned.
• If the lapse rate is between 18 Kelvin and 22 Kelvin, a value of 2 is assinged.
• If the lapse rate is greater than 22 Kelvin, a value of 3 is assigned.

Dew point Depression Subcomponent:
• If the 700 hPa dew point depression is less than 15 Kelvin, a value of 1 is assigned.
• If the dew point depression is between 15 Kelvin and 21 Kelvin, a value of 2 is assinged.
• If the dew point depression is greater than 21 Kelvin, a value of 3 is assigned.



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