Wind Chill function

The Wind Chill function is useful for identifying dangerous winter conditions that, depending on exposure times to the elements, can result in frostbite or even hypothermia. Wind chill is a way to measure how cold an individual feels when wind is taken into account with already cold temperatures. The faster the wind speed, the more quickly the body will lose heat and the colder they will feel.

Notes

The formula the function uses to compute wind chill is as follows:

WS16 = np.pwer(WS, 0.16)
Wind Chill = 35.74 + (0.6215 * T) - (35.75 * WS16) + (0.4275 * T * WS16)
  • T= Air Temperature
  • WS = Wind speed

Parameters

ParameterDescription

Temperature Raster

A single-band raster where pixel values represent ambient air temperature.

Temperature Units

The unit of measurement associated with the input temperature raster. Available input units are Celsius, Fahrenheit, and Kelvin.

Wind Speed Raster

A single-band raster where pixel values represent wind speed.

Wind Speed Units

Defines the unit of measurement for the wind-speed raster:

  • Miles Per Hour (mph)
  • Kilometers Per Hour (km/h)
  • Meters Per Second (m/s)
  • Feet Per Second (ft/s)
  • Knots (kn)

Wind Chill Units

The unit of measurement associated with the output raster. Available output units are Celsius, Fahrenheit, and Kelvin.

References

Steadman, Robert G. "Indices of Windchill of Clothed Persons." Journal of Applied Meteorology and Climatology (JAMC) 10.4 (1971): 674–683.

National Weather Service. "NWS Wind Chill Chart." http://www.nws.noaa.gov/om/winter/windchill.shtml