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Humidex - Why is it not used in forecasts?


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Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    when It comes to summer time I used to find the humidex or heat index invaluable in my day to day life when I lived in North America..so I wondered why it is not used widely here?..we use windchill esp in winter for how cold it actually feels but not the humidex for how warm it actually feels..so any reason why not?

     

    http://en.wikipedia.org/wiki/Humidex

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    Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

    Meteociel have humidex charts - here's the one for Friday afternoon.

     

    Posted Image

     

    They also do windchill in winter.

     

    I should also add that they have the humidex under current obs section.

     

    http://www.meteociel.fr/observations-meteo/humidex.php

    Edited by Gael_Force
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    Posted
  • Location: Medway - 125m ASL
  • Weather Preferences: Hot summers, snowy winters and thunderstorms!
  • Location: Medway - 125m ASL

    Isn't that the same thing as 'feels like' temperature? If so, I see it all the time on forecasts.

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    Posted
  • Location: N.Bedfordshire, E.Northamptonshire
  • Weather Preferences: Cool not cold, warm not hot. No strong Wind.
  • Location: N.Bedfordshire, E.Northamptonshire

    Isn't that the same thing as 'feels like' temperature? If so, I see it all the time on forecasts.

    Have to repeat this comment also.

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    Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    Have to repeat this comment also.

    I have never seen it in a forecast over here eg tomorrow will be 28c but will feel like 35c

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    Posted
  • Location: The Purbeck Microclimate, Dorset.
  • Location: The Purbeck Microclimate, Dorset.

    I have never seen it in a forecast over here eg tomorrow will be 28c but will feel like 35c

    Yeah, it's 'feels like temperature' here. The MO use it on there website for my local area.
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    Posted
  • Location: Medway - 125m ASL
  • Weather Preferences: Hot summers, snowy winters and thunderstorms!
  • Location: Medway - 125m ASL

    Most of the big sites do.

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    Posted
  • Location: West Sussex
  • Weather Preferences: Outdoors
  • Location: West Sussex

    Yep, we use a 'feels like' temperature on all the forecast pages.

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    Posted
  • Location: N.Bedfordshire, E.Northamptonshire
  • Weather Preferences: Cool not cold, warm not hot. No strong Wind.
  • Location: N.Bedfordshire, E.Northamptonshire

    I have never seen it in a forecast over here eg tomorrow will be 28c but will feel like 35c

    http://www.netweather.tv/index.cgi?action=10day;sess=

     

    ten day forecast here does that :)

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    Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)

    im talking about main stream tv forecasts

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    Posted
  • Location: Cheddington, Buckinghamshire
  • Weather Preferences: Winter: Cold & Snowy, Summer: Just not hot
  • Location: Cheddington, Buckinghamshire

    im talking about main stream tv forecasts

     

     

    I found that US forecasts are much more technical. The BBC and others have dumbed it down so much I reckon they don't think the public can cope with a "feels like" temperature.

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    I have never seen it in a forecast over here eg tomorrow will be 28c but will feel like 35c

     

    One aspect is that the Met Office use heat index rather than humidex for their 'feels like' temperature, which under UK conditions will rarely give a perceived temperature higher than actual.

     

    The feels like temperature apparently uses wind chill for low temperatures, heat index for high, and a combination of the two inbetween as described on their blog here - http://metofficenews.wordpress.com/2012/02/15/what-is-feels-like-temperature/

     

    A number of other indices have been derived to supposedly describe perceived temperature more accurately such as the Universal Thermal Climate Index (UTCI) which factors in temperature, humidity, wind chill, solar radiant energy, clothing and metabolic rate to work at both high or low temperatures, warning of heat stress or frostbite for example.

     

    But with regards to high temperatures and humidity, the wet bulb temperature is the temperature the skin feels with evaporation of perspiration and it lies between the temperature and dewpoint - adding these together gives a rough estimate as to the feel of the airmass.

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    Posted
  • Location: The Purbeck Microclimate, Dorset.
  • Location: The Purbeck Microclimate, Dorset.

    What I will say is though, I completely disregard the MO feels like temps, because they are so wrong. My own Davis station calculates this fairly accurately, the MO feels like temps is 3°C below the actual air temp, which is impossible with the humidity today.

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    What I will say is though, I completely disregard the MO feels like temps, because they are so wrong. My own Davis station calculates this fairly accurately, the MO feels like temps is 3°C below the actual air temp, which is impossible with the humidity today.

     

    Well as pointed out they use heat index which needs relatively high dew points or temperature to give feels like values higher than ambient - for example Bournemouth near to you is reporting 20°C temperature and 15°C dewpoint which gives a heat index of 20°C, and they may possibly be including a wind chill factor.

    Humidex gives a value of 24°C.

    Edited by Interitus
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