Saturday, August 05, 2006

But How Do You Feel? Part 2: The Kookiness of Qualitative Calculations

Think the 102ºF temperature in Queens on Wednesday was hot? Well, that may have been the actual temperature but my weatherman told me it really “felt like” it was 115ºF.

I hate TV weather forecasts. Like most people, I watch them almost every day so I know what to wear, but a few things about them enrage me all out of proportion. 1) Endless talk about “what the temperature should be today” when they mean average. 2) Hyping weather extremes; how predicted snowfalls, for example, become less and less as a storm nears. 3) Eyewitness weather. If we’re getting lots of rain or snow, I can see it from my window. You don’t need to hustle your reporters to seven local communities to show me the weather there.

And, the subject of this post, 4) Wind chills and heat indices. That is, “what it feels like,” according to the weather folks. These distortions of the temperature just drive me fucking crazy. I suppose they are just a special case of point 2, but they are so common and so aggravating, that I am giving them their own special category.

Smack the link for the smackdown. GRRRRR!

I understand the point of these hand-waving distortions of the outside temperature. Both are designed to capture some of the effects related to the dynamism of the weather system, particularly as it relates to moisture. When the cold wind blows, it strips away the insulating layer of air that surrounds us, bringing new, cold air into contact with our skin; the wind also speeds up evaporative cooling. When the heat that surrounds us is extra-steamy, the humidity slows down that evaporative cooling.

But the fact remains that they don’t change the objective temperature. The wind can whip up as high as it wants, but that air is the same temperature as it would be if it was still. Really, wind chill is an indicator of rate of heat loss; windy days just reduce the temperatures of things faster. But those things can never go below the ambient temp. Likewise, humidity doesn’t change the air temperature when it is hot, it just slows down how your body cools itself.

My biggest gripe is that these measures are so subjective. Let’s say it is 15ºF outside. Like anyone, I cringe when the teeth of a cold blast of air bite into my cheeks and they feel like they are in 0ºF weather. But maybe then the gust dies down, and my cheeks feel—still cold, mind you—a bit better. Then maybe the clouds part, and the sun warms my face, and I find it “feels like” it is warmer than the actual air temperature. Yet the only measure of subjectivity we gravitate to is the scary extreme one.

My second complaint is that these measures are unnecessary. When the temperature is either really hot or really cold, a reading of the air temperature contains enough information. Pulling down the low or pushing up the high doesn’t really matter. In the above example, 15ºF is still damn cold. No one should go into that weather without some attention to protecting themselves against it. Dramatizing the cold by making it seem colder helps no one.

Finally, I simply hate that drama, the self-importance of the weatherman who tells you that, although it is 95ºF, [now looking into the camera with concern in his eyes and authority in his tone] it really feels like it is 100ºF. So be careful out there, in that complicated world that has just been simplified into a hype-tastic extreme.

[/grumpy old man mode]

2 comments:

Mrs. C said...

Comstock, you need to chill out! People like indices measuring wind chill and heat factor because it validates their subjective experience of miserable weather.

And what's so bad about that?

MattG said...

I find it funny that its necessary to lump (just) two measures into one, because the two independently are, perhaps, too confusing. I prefer, "well it's 95` outside, but its also humid". I know what humidity does to how I feel about the heat. or "it's 20` out there but the wind is pretty brutal". yup, i know what a good wind does on a cold day. I really feel like that is certainly enough information for me to figure out what to wear. And Mrs C, isn't that enough to validate our subjective experience?

As you said, the single how-it-feels unit is only for drama and breaking records.. americans do love to break records. But let's not forget the other side of the coin: lets say its 95` and humid, but not crazy humid. so the heat index is only 97`. well damn i might still feel like it was pretty miserable.. and now some fuck is probably going to tell me, "well the heat index is only 97`, last year the heat index was 105`". Thus totally invalidating my subjective experience that it was miserable out. with "its 95` and humid".. there's no hard fast rule, and our subjective experience carries more weight. While that same jerk can say, "it was hotter last year", i can still say "i think its damn uncomfortable, as its both hot and humid" and the debate ends there. My subjective experience triumphs.

These record breaking stats are like drugs.. They only work now because we never had them previously, so it seems like we're breaking records. They'll suffice for a few years, but eventually "meteorologists" are going to to have to come up with a new measure, combining a 3rd and 4th factor so we can start the record-breaking all over again.

So to save us from this vicious circle and to save our subjective experience we must rail against the weatherman and his hurricane of injustice.