Weather Notebook
Bryan Yeaton

Wooly Bears
Wed Nov 10, 2004

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Wooly Bear Forecasts—Myth or Reality, next on The Weather Notebook.

Hi, I'm Bryan Yeaton for The Weather Notebook. In a battle of long range forecasting, who’s more accurate—the wooly bear caterpillar or the computer?

If you haven’t heard about this fuzzy caterpillar, it is the larval form of the Isabella Tiger Moth. In other parts of the country they are called “black-ended bears” or “wooly worms.” They're a couple inches long, black on each end with a brown band around the middle. Folklore says that if the brown band is wide, then the winter will be mild and if the brown band is narrow, then get ready for deep snow and cold well into April. It's a quick and charming way to forecast the weather but, unfortunately, it doesn't appear to have much merit.

The American Museum of Natural History and other organizations have actually studied these little critters, and found no connection between their stripes and the severity of the coming winter’s weather. Some think, however, that the stripes may indicate how bad it was last winter, as the width of the stripes seems to rely on when the caterpillar was able to emerge from hibernation, and begin its molting process.

In an agricultural society, where these sayings developed, deep snow all winter was good for the soil, so these signs may have been simply wishful thinking. But in a technical world, though it's nice to think that animals can sense atmospheric subtleties, it's the computer that wins out. Still, let’s see your computer try to spin a cocoon.

Go to our website, to find links to the annual Woolly Worm Festival held every October in Banner Elk, North Carolina. You can see who won this year’s caterpillar race. No kidding. The Weather Notebook is underwritten by Suburu of America. We are produced by the Mount Washington Observatory.

Wooly Bear Study

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