← Back to team overview

weather-indicator-team team mailing list archive

[Bug 617801] Re: Weather Indicator should show humidex value

 

** Changed in: weather-indicator
    Milestone: None => 11.02.16

** Changed in: weather-indicator
   Importance: Undecided => Wishlist

-- 
You received this bug notification because you are a member of Weather
Indicator Team, which is the registrant for Weather Indicator.
https://bugs.launchpad.net/bugs/617801

Title:
  Weather Indicator should show humidex value

Status in Indicator-Weather:
  New

Bug description:
  How is the humidex calculated?
  A.

  The Humidex formula is based on the work of J.M. Masterton and F.A.
  Richardson at the Atmospheric Environment Service (now MSC) of
  Environment Canada in 1979. It is a standard for Canada, but
  variations are used around the world. The dew point temperature should
  be given in kelvins (temperature in K = temperature in °C + 273.16)
  for the formula to work. The magic number 5417.7530 is a rounded
  constant; it's based on the molecular weight of water, latent heat of
  evaporation, and the universal gas constant.

  e = vapour pressure in hPa (mbar), given by:
  e = 6.11 * exp [5417.7530 * ( (1/273.16) - (1/dewpoint) ) ]

  h = (0.5555)*(e - 10.0);
  humidex = (air temperature) + h

  from Environment Canada web site