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Dave Thurlow, Host

 
It's that time of year again . . . time to get out the trusty ruler for those times when thunder rumbles and ice falls from the sky. I'm Dave Thurlow for the Weather Notebook. The second half of spring is the most likely time for hail to fall across much of the U.S. East of the Appalachians, hail is pretty rare, occurring in most places only about once a year. When it does fall in the East it's typically pea or marble sizeÑthat's one-quarter to one-half inch in diameter. If it's at least dime size, three-quarters of an inch wide, then its parent thunderstorm is classified as severe.

NCAR Photo

The country's hail capital is the Great Plains - especially the high plains of Kansas, Nebraska, Colorado, and Wyoming, where up to 10 storms each year provide a bountiful hail harvest. June and July are the "hailiest" months on the high plains. Here, the hailstones can be so mammoth that you have to forget about peas and dimes and go straight to the sporting-goods store for comparison. Golf-ball-sized hail is just under two inches across, while tennis-ball-sized hailstones are two and a half inches wide. Then there's the real monsters: grapefruit size (four inches) and softball size (four and one-half inches).

If you live for large hail, you'll like this tall tale. In the 1970s, before his big break, David Letterman was a TV weathercaster in Indianapolis, but his comedic talents were already being honed. Letterman once warned viewers to watch for hailstones the size of canned hams. So much for the career in meteorology. For a look at the country's biggest hailstone, check out our homepage at www.mountwashington.org/notebook.

Funding for our show is provided by Subaru, the beauty of all-wheel drive and by the National Science Foundation.