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Webtags (preserving history): Difference between revisions
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var actualVaporPress = <#RecentHumidity h=3>/100) * 6.105 * Math.exp(17.27 * <#RecentOutsideTemp h=3>) / (237.7 + parseFloat(<#RecentOutsideTemp h=3>)))); | var actualVaporPress = <#RecentHumidity h=3>/100) * 6.105 * Math.exp(17.27 * <#RecentOutsideTemp h=3>) / (237.7 + parseFloat(<#RecentOutsideTemp h=3>)))); | ||
var appTempDegC = parseFloat(<#RecentOutsideTemp h=3) + (0.33 * actualVaporPress) - (0.7 * <#RecentWindSpeed h=3>) - 4; | var appTempDegC = parseFloat(<#RecentOutsideTemp h=3) + (0.33 * actualVaporPress) - (0.7 * <#RecentWindSpeed h=3>) - 4; | ||
Feels Like as implemented at version 3.6.10 (see [[#Feels_Like|Feels Like section below Current condition web tags]]) reports exactly same as wind chill for temperatures '''below''' 10°C or 50°F: | |||
<pre>if(wind_km_h < 4.828) WC = tempDegC; | |||
else{ | |||
wind_pow = Math.pow(wind_km_h, 0.16); | |||
WC = (13.12 + 0.1625 * tempDegC) - (11.37 * wind_pow) + (0.3965 * tempDegC * wind_pow);// Brackets used to ensure "+" is interpreted as addition not concatenation | |||
} </pre> | |||
For temperatures '''above''' 20°C or 68°F it uses: | |||
<pre>var actualVaporPress = (humVal/100) * 6.112* Math.exp((17.62*tempDegC)/(243.12 + tempDegC)) / 10.0; // Not same as at build 3084 | |||
/* uses kilometres per hour for wind speed */ | |||
var wind_km_h = calcWind(windSpeedStr, windUnit, "km/h"); | |||
/* What Cumulus MX will use to calculate apparent temperature for feels like is changed very slightly */ | |||
if(wind_km_h > 72) wind_km_h =72; | |||
AT= (1.04 * tempDegC) + (2 * actualVaporPress) - (0.1805553 * wind_km_h) - 2.7;</pre> | |||
For in-between temperatures it uses a more complicated formula where AT and WC are defined as above: | |||
<pre>app_temp_mult = ( tempDegC - 10) / 10; | |||
wind_chill_mult = 1 - app_temp_mult; | |||
FL= AT * app_temp_mult + WC * wind_chill_mult;</pre> | |||
==Today== | ==Today== | ||
