Wind Chill, Apparent Temperature or Feels Like Temp

Post Reply
User avatar
WyoDog
Advisor
Advisor
Posts: 67
Joined: Wed Aug 23, 2017 6:39 pm
Location: Powell, WY USA
Station model: Davis Pro2
Software: Weather Display
Contact:

Wind Chill, Apparent Temperature or Feels Like Temp

Post by WyoDog » Thu Dec 07, 2017 6:23 am

I have a question about ssGauges - Feels Like or Apparent Temp.

I have been searching through this forum for 'wind chill' and it seems to me that these three terms are being used somewhat interchangeably. Depending on your language choice you will see either wind chill or apparent or feels like.

As we know these three terms are quite different. Wind chill developed by USSR before the second world war. Feels Like and Apparent use temp, wind speed or humidity (for different temp ranges) and then there's RealFeel a proprietary algorithm of AcuRite (AccuWeather) that uses 7 different parameters.

It seems to me that RealFeel is the most desirable calculation of what the current conditions actually 'feel' like, but good luck wrestling that away from AcuRite.

In a effort to simplify terminology (at least in my head) which algorithm is used is used to calculate the value displayed as
Apparent Temperature on mouse tip and Feels Like on the gauge. (in English US)

I understand that Mark provided the original code for the ssGauges. Any idea what we are displaying? Jachym?

Your thoughts?
Terry

Image

User avatar
Jachym
Site Admin
Site Admin
Posts: 1686
Joined: Fri Aug 18, 2017 10:12 pm
Location: Brno, Czech Republic
Station model: WH1080
Software: Meteobridge
Contact:

Re: Wind Chill, Apparent Temperature or Feels Like Temp

Post by Jachym » Thu Dec 07, 2017 11:38 am

Wind chill is not the same as feels like/apparent.

This is only used in the Current block and is calculated differently.

Apparent temp / Feels like are equivalent and usage of them depends on UK/US english. US strings use "feels like". This will differ between websites, but should be the same on single MT website because it uses the same language file.

Apparent/feels like:

Code: Select all

// Apparent temperature calculation
    // accepts temperature [C], humidity [%], wind speed [m/s]
    // returns apparent temperature [C]
    function apparent($apparentT,$apparentH,$apparentW){
        $e = ($apparentH/100)*6.105*pow(2.71828, ((17.27*$apparentT)/(237.7+$apparentT)));
        $calcA = round(($apparentT + 0.33*$e-0.7*$apparentW-4),1);
        return $calcA;
    }

User avatar
BobW55
Forecaster
Forecaster
Posts: 115
Joined: Thu Sep 28, 2017 11:43 pm
Location: Michigan USA
Station model: Davis Pro2
Software: Cumulus
Contact:

Re: Wind Chill, Apparent Temperature or Feels Like Temp

Post by BobW55 » Sat Dec 16, 2017 1:08 am

A few years ago here in the USA there was a push to change from the old "WIND CHILL" to Apparent or "Feels Like" temperature. Most TV news weather now only reports the FEELS LIKE value, a few report Apparent.
I know I switched off the selection in my SS-gauges to only show Apparent temperature, Dew point, Wind Chill, and Heat Index pop up on the graph.
http://melvinweather.com/template/indexDesktop.php
Davis Vantage Pro2 wired
Solar/UV sensors
Sky Cam
Ham radio K8pos

User avatar
Jachym
Site Admin
Site Admin
Posts: 1686
Joined: Fri Aug 18, 2017 10:12 pm
Location: Brno, Czech Republic
Station model: WH1080
Software: Meteobridge
Contact:

Re: Wind Chill, Apparent Temperature or Feels Like Temp

Post by Jachym » Sat Dec 16, 2017 10:09 am

The problem with wind chill is that it does not take into account humidity and is only defined for temperatures below 10°C (50F)

Post Reply