Wind Chill - higher than air temp ???

[sarabande]

I've been looking at Netweather.tv to see how the imminent thunder and rain is developing.

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


An element of perplexitousness has crept in, as the "Feels like" figures (by which I understand the Met Office and others to mean "Wind Chill" ) are higher than the air temp.


View attachment 33842

As my seaweed has totally dried out over the last few weeks, can someone explain please how the increased figure is obtained ?


Yours, living in the fridge.

 

[TimBennet]

It's not windchill, but is based on the Thermal Comfort Index. It takes into account temperature, humidity, windspeed, etc to say what it feels like compared to a given temperature with more reasonable humidity (in particular).

So 49°C in the Limpopo valley (99%humidity) feels worse than 49°C in Death Valley (23%). Much worse.

 

[macd]

So 49°C in the Limpopo valley (99%humidity) feels worse than 49°C in Death Valley (23%). Much worse.

...unless, of course, you're dead. But spot-on otherwise.

 

[sarabande]

so the Wind Chill Factor and Thermal COmfort Index are separate entitities ?


If so, what happens when it's middling warm and blowing a bit.

I must find out the equations

 

[macd]

so the Wind Chill Factor and Thermal COmfort Index are separate entitities ?


If so, what happens when it's middling warm and blowing a bit.

TC includes wind chill effects, wind chill being just one element in a rather more complex subject. Take a day when it's 40C, but humidity is low and there's a moderate breeze: evaporation from the skin will increase your comfort (or, at least, decrease discomfort). But if it's 18C , low humidity and breezy, you'll need to don an extra layer, and obviously a wind-proof outer will particularly help.

I think the TC index originally came about as a means of refining environmental conditions in buildings, rather than outdoors, but the mechanisms are much the same. No doubt Google could offer you further reading.