The "Roses" of Autumn

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Lake-Effect Snowstorms

The Great Lakes together form the largest chain of fresh-water bodies in the world. They are also positioned at a rather northerly latitude and at the southern edge of mostly flat terrain extending all the way from the pole. It's understandable, then, that the lands due east of them are prone to spectacularly intense and huge snowfalls from lake-effect snowstorms.

In most American locales, February is noted as the great snow month, and you might suppose that November is too early for really big snowfalls anywhere in the lower 48 states. But lake-effect snowstorms depend on unfrozen lakes—so it is in November and December that most of them happen. How does a lake-effect storm occur? A storm moving in from the west may produce light snow before it reaches the lakes. But in crossing those vast and relatively mild bodies of water the storm loads up on moisture. Then, when the precipitation moves over the territories east of the lakes, the colder temperatures over land turn the rain back into snow: tons of snow.

Lightning may flash and thunder roll while this snow comes down at rates of up to 5 to 10 inches an hour. The great snow depths are remarkably localized. Although 70 inches of snow fell in one day on January 4-5, 1988, in Highmarket, New York, only 15 miles away there was less than 6 inches of snow! Interestingly, the maximum amount occurred about 30 miles east of Lake Ontario—the heaviest lakeeffect snows don't fall right on the eastern shores of the lakes.

A lot of people might suppose that the Great Lakes are too big to freeze up entirely. Actually, the southernmost and shallowest of the five, Lake Erie, does usually freeze over completely—after which Buffalo, New York, and Erie, Pennsylvania, are spared major lake-effect action. Lakes Superior, Huron, and Michigan normally get no more than about half frozen over. Lake Ontario has only frozen completely a few times since 1860, and in a typical winter is 85 percent ice-free. Its water does get colder as winter advances, but the "snow belt" east of it in upstate New York can experience huge lake-effect snows onward through the season.

Hale-Bopp and the Leonids

Many of our readers no doubt got a look at the amazing visitor to our skies this past March: Comet Hyakutake. Back on March 25, it passed closer to Earth than any fairly large comet had in 440 years. The fuzzy glowing head thus appeared huge—and on the best nights, as seen from out in the country, distinctly blue even to the unaided eye. The head and brightest tail were bright enough to be glimpsed from the centers of the largest cities without optical aid. And in rural areas the tail appeared longer than the Big Dipper, which it passed through majestically. (Some expert observers traced the faintest extension of the tail halfway across the sky!)

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