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Feels Like: Difference between revisions
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→Introduction: Add note about JAG/TI
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=Introduction= | =Introduction= | ||
''Feels Like'' is a concept often quoted in weather forecasts, as the name suggests it attempts to quantify what a human detects as the warming or cooling effect. | ''Feels Like'' is a concept often quoted in weather forecasts, as the name suggests it attempts to quantify what a human detects as the warming or cooling effect. | ||
A number of formulae are used, all involve the air temperature and at least one of the following: | A number of formulae are used, all involve the air temperature and at least one of the following: | ||
* (relative) humidity | * (relative) humidity | ||
* wind (speed) | * wind (speed) | ||
* sunshine (radiation) | * sunshine (radiation) | ||
Davis stations also provide [[Webtags#Davis | THW index and THWS index ]] | Cumulus MX from version 3.6.0 fully supports the latest "Feels Like" definition as agreed by the Joint Action Group for temperature Indices (JAG/TI). The rest of this article was written before this was available, and discusses a way of picking between the alternative measures listed below, based on the current weather conditions. The '''JAG/TI feels like''' scale effectively uses '''wind chill''' below 10 degrees Celsius, apparent temperature above 20 degrees C, and blends the two values between 10 and 20 degrees C. | ||
That version and earlier versions of MX and versions of Cumulus 1 since those shown support earlier definitions for feels like: | |||
*From Version 1.9.1 (6 April 2011) [[Apparent_temperature]], this index was introduced by Steadman in 1971, and the Cumulus implementation uses his later 1998 formula. | |||
*Although [[Heat_index]] was available in earlier versions, it was improved from version 1.9.0 (11 Sept 2010) in Cumulus 1 with a new formula covering a greater range of humidities accurately. | |||
*Although [[Humidex]] was available in earlier versions, it was first correctly implemented from version 1.8.9 (31 Mar 2010). | |||
*Although [[Wind_chill]] was available in earlier versions, it was only from version 1.8.8 (1 Dec 2009) that Cumulus included it on graphs after introducing in same version (earlier build) a check that wind speed and temperature readings were available. | |||
Davis stations also provide [[Webtags#Davis | THW index and THWS index ]], other ways of expressing Feels Like. | |||
= Web implementation = | = Web implementation = | ||
