Dear Tom,
The largest hailstone I have seen was golfball size-slightly more than one inch in diameter. Its ice was almost crystal clear, except for a milky white middle quarter inch. Does large hail have the same clear consistency as smaller hailstones or do they become slushy when unusually large? Scott Hanneman
Dear Scott,
The milky white color you describe occurs due to bubbles trapped in the ice. Contrarily, clear ice suggests a very limited amount of trapped air. For such a large hailstone to have displayed such clarity is fairly rare, says Dr. Charles Knight who researches hail and ice at the National Center for Atmospheric Research (NCAR). It’s also a bit unusual for hailstones in the Midwest to be so clear, he adds. Such clarity is more frequently found in hail-much of it fairly small-which accompanies Colorado and western thunderstorms, whose clouds are colder and occur in drier overall atmospheric conditions.
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Tom Skilling is chief meteorologist at WGN-TV. His weather forecasts can be seen Monday through Friday on WGN News at noon and 9 p.m.
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