Facetime with Wind Chill
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Finally, the wind chill index is getting some more face time!

Hi, I'm Bryan Yeaton for The Weather Notebook.

You're wondering what I mean? Well, maybe you've heard about the new windchill index.

Introduced by the US and Canada. It works much like the old one, but you'll notice that the numbers don't plummet down quite so far. In other words, the wind-chill temperatures aren't as far from the actual temperatures as they used to be.

Why is that?

The old wind chill index was based on the wind speeds you'd hear on the weather report. But those speeds were measured at a height of 10 meters, or about 33 feet off the ground. Pretty far from your face.

The new wind chill index reflects wind speeds measured at about 5 feet from the ground which is obviously much closer to the height of your face. Closer to the ground, the wind doesn't blow as hard thanks to friction, hence the higher temps.

There's more than one facial factor in this new windchill mix.

Our cheeks are one of the most likely places to get frostbite, because they're often left uncovered and because we radiate a lot of heat from our faces. But--get ready civil libertarians---not all cheeks are created equal.

In fact, one person's cheeks may be twice as resistant to cold as another's. The new wind-chill index is designed to protect the 5 percent of the public who are the most thermally resistant. Their bodies don't transfer heat through the cheeks very easily. So their cheeks might be freezing even though their body temperature is near normal and they might not realize their skin is turning to ice. Those with a low thermal resistance feel the cold wind and are ‹more likely to bundle up before frostbite sinks its teeth into your face.

Today we thank writer and meteorologist Bob Henson who avoids frostbite in Boulder, Colorado. The Weather Notebook is a production of the Mt. Washington Observatory and is supported, in part, by the National Science Foundation.