Weather: Going in Circles

Going in Circles

Now that you understand why the sky is blue and why it rains, you are, without question, more meteorological than most. You are at least ready to stand in front of a camera, point to a blank blue wall, and smile. After all, that's what we television people make a career doing. Benjamin Franklin once said, "Some people are weather wise and some are otherwise." You are no longer in that "otherwise" category.

The next big step is to look at how the atmosphere puts it all together. In many respects, meteorology is not only a study of things that bump in the night—and day—but a study of things that go in circles. Those circles come in many different sizes and the nature of the weather that's unleashed really depends on the circles that are put into motion. But through it all, there is one common theme: If the atmosphere goes up, the rain comes down. We'll look at how the weather twist contributes to those ups and downs.

Storms 'R' Us


Between 1980 and 1998, the United States sustained 37 weather-related disasters in which the damages and costs for each exceeded $1 billion.

See Billion Dollar U.S. Weather Disasters.

The earth is a storm factory, where monsoons, hurricanes or typhoons, tornadoes, and blizzards are all made fresh daily. Thanks to unequal heating between the equator and poles, phenomenal amounts of energy are unleashed. A single thunderstorm has the power of millions of nuclear bombs. The production never ceases. And in mid-latitudes, where most people live, the atmospheric smorgasbord offers quite a variety.

Weather Words

"Neither snow, nor rain, nor gloom of night stays these couriers from the swift completion of their appointed rounds."

—Inscribed on the Main Post Office in Manhattan. The quote comes from words of the ancient Greek historian Herodotus. In the fifth century B.C.E., he wrote:

"Not snow, no, nor rain, nor heat, nor night keeps them from accomplishing their appointed courses with all speed."

Later we'll focus on global-circulation patterns, but for now think of it this way: All the heat energy taken in at the equator has to go someplace and it travels toward the poles. The greatest exchange of that energy takes place at around 45 degrees latitude, near the world's population centers. So all the excess heat of the southern latitudes must travel 45 degrees to balance the lack of heat in the polar regions. The mid-latitudes are the Times Square of the atmosphere. Through this great intersection, everything must pass. Sure, every corner of the earth experiences wild and wacky weather, but because of the meteorological intersection across the middle every conceivable form of weather will take place.

Take the United States. Everything happens here: Tornadoes, floods, hurricanes, snowstorms, hailstorms, and dust storms are all part of our normal weather. In some parts of the nation, the entire weather glossary can be unleashed in a single year. The northeastern United States is especially vulnerable to just about anything the weather might cook up. A former director of an emergency-operations center once said to me, "If it's going to happen, it will happen here."

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Excerpted from The Complete Idiot's Guide to Weather © 2002 by Mel Goldstein, Ph.D.. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.