weather hype- the wind chill factor

[Underhill]

-4 F this morning. Before any wind chill.

Hoping this keeps up so we can get out on the ice....

 

[konradv]

Why don't they report wind chill temps during the summer.
i.e. it's 90, but with the wind it feels like 80.

In the summer it's the Heat Index that gets reported. We listen to find out if something bad is likely to happen. The good stuff we know just by going outside.

 

[mamooth]

Heat index does matter, since sweating is such a large portion of heat loss. If the temp was 108 with 100% humidity, you'd still die no matter how fast the wind was blowing, as sweat could not evaporate, nor could body heat could flow out into to the higher temperature wind.

However, I think wet bulb temps are a better way to state it, though the numbers aren't as impressive, because wet bulb temps are below normal temps. Unless humidity is near 100%, in which case they'll be the same. When wet bulb temps start approaching human body temperature, the humans who can't get into a cool spot start dying. All of them, not just the fragile ones, because they can't get rid of the heat. There's currently no place on earth where that happens for more than brief instances, but some spots in India get close.

There's actually no spot in the USA that gets the often-quoted "90 degrees with 90% humidity", and there are darn few places on earth that do. 94/94 would be right out, and would also be uncomfortably near the lethal range. What we consider an unbearably muggy 90-degree day would have 60% humidity.

 

[Oddball]

Sorry OB but the wind chill factor has nothing to do with the rate at which skin freezes. Simply put the WCF is the "felt" air temperature on exposed skin. Inanimate objects cannot get below the ambient temperature no matter how hard the wind blows. The attempt to maintain surface temperature in an environment of faster heat loss due to wind results in the perception of lower temperature. The THI is interesting in the fact that it considers the relationship between ambient heat and humidity but does not take wind speed into consideration even though it is an important factor.

That's because heat is lost when more air passes over the skin....Especially cold air.

The WCF is at least semi-scientific, while the "heat index" is pure media generated crap.

Contrary to popular myths the wind is never colder than the actual temperature. It just feels cold. Your chances for frostbite have nothing to do with the wind. The ironic thing is that the "heat index" doesn't take the wind into consideration. It's all hype.

No but the wind increases evaporation and increases vasoconstriction, which decreases frostbite/freeze time on exposed skin...The "heat index" is total pap.

 

[saveliberty]

If its hot, I drink more water. If its cold, I wear more clothes. Any questions?

 

[Mr. H.]

The point at which wind chill meets heat index...

The Twilight Zone.

dee dee doo doo, dee dee doo doo...

 

[Saigon]

Living in Finland, I find Wind Chill Factor an essential piece of information at this time of year.

The amount of times I have read that it is -5C and stepped outside to find it felt like - 15C...what I want to know is how I need to dress, not what the thermometer says. That means WCF is crucial.

 

[Mr. H.]

Living in Finland, I find Wind Chill Factor an essential piece of information at this time of year.

The amount of times I have read that it is -5C and stepped outside to find it felt like - 15C...what I want to know is how I need to dress, not what the thermometer says. That means WCF is crucial.

You've had that same sad avater for some time now. Put the head down and get the bitch back on pump.

 

[Saigon]

Mr H -

I also haven't posted for around 6 months as I've been away traveling.

 

[Mr. H.]

Mr H -

I also haven't posted for around 6 months as I've been away traveling.

Well, weclome back sag on.

 

[Saigon]

There ya go - I even changed my avator for you!

This is a nice pic of an Azeri attack helicoptor that flew over me a couple of years back!

 

[percysunshine]

Wind chill factor empirical experiment:

Person 1, normally clothed for room temperature, 20 degrees F, no wind, polled for feeling...."it is really cold"

Person 2, heavily clothed for room temperature, 20 degrees F, no wind, polled for feeling...."it is snug"

Person 3, naked, 20 degrees F, no wind, polled for feeling...."it is really fucking cold!"

Person 4, naked, 20 degrees F, 10 mph wind, polled for feeling...."it is fucking zero!"

Thus, 10 mph = minus 20 degrees in the wind chill factor calculation.