What are the different size categories for hailstones?

In the United States, the following terms are used to describe the size of hailstones in weather reports. The actual sizes of the hailstones often don't match up to their supposed similes.

Hailstone Description Diameter (inches/centimeters)

Pea

0.25 / 0.65

Marble

0.50 / 1.25

Penny, dime, large marble

0.75 / 1.90

Nickel, mothball

0.88 / 2.25

Quarter

1.00 / 2.50

Half dollar

1.25 / 3.20

Walnut

1.50 / 3.80

Golf ball

1.75 / 4.45

Hen egg

2.00 / 5.00

Tennis ball

2.50 / 6.35

Baseball

2.75 / 7.00

Tea cup

3.00 / 7.60

Grapefruit

4.00 / 10.25

Softball

4.50 / 11.40

Is there such a thing as a megacryometeor?

Yes. Megacryometeors are not hailstones because they don't form in clouds the way hailstones do. They are giant ice stones that do not require thunderstorms in order to form. Megacryometeors range in size from about a third of a pound (half a kilogram) to a monstrous one found in Brazil that weighed 137 pounds (62 kilograms). But how do they form? One argument is that they come from airplanes, but not from toilet drainage because this would mean contaminants and cleaners would be found in these large ice stones. However, ice might still form and break off of airplanes while in flight, and since it could take as much as three minutes for such a piece of ice to reach the ground, such megacryometeors might seem to come from out of the blue because the jet plane is long gone by then. A growing number of meteorologists, however, do not buy into the airplane scenario. They speculate that cooling and water vapor conditions within the tropopause that are still little understood may explain the formation of megacryometeors.

What are the "hail belts"?

Hail belts are regions that are ideal for hail storm formation. They can be found downwind of mountain ranges, usually in mid-latitude areas. Among the hail belt

Was the huge ice stone found in Hartford, Connecticut, really a hailstone?

No. On April 30, 1985, a 13-year-old-boy found a block of ice that was 1,500 pounds (680 kilograms), which had apparently fallen from the sky and onto his backyard lawn. No one ever figured out where it came from (sometimes, though, chunks of ice can fall from passing airplanes), but it was definitely not a natural hailstone.

regions are the Central Plains in the United States and Canada, Central Europe and parts of the Ukraine, southern China, Argentina, and parts of Central and South Africa and southeastern Australia.

What are some notable record hail accumulations?

In 1968, a storm in Illinois dumped the equivalent of 82 million cubic feet (2.32 million cubic meters) of ice over a 620,000 acre area. Then, in 1980, a hail storm in Orient, Iowa, left hail drifts that were six feet (1.8 meters) deep.

What U.S. cities tend to get the most hail?

The following U.S. cities are on the Top 10 list for receiving the most hail annually.

• Cheyenne, WY

• Tulsa, OK

• Amarillo, TX

• Oklahoma City, OK

• Wichita, KS

• Dallas/Ft. Worth, TX

• Arlington, TX

• Denver, CO

• Colorado Springs, CO

• Shreveport, LA

Do hailstones have rings?

Yes, but unlike with trees, the rings do not indicate the age of the hailstone. Italian physicist Alessandro Volta (1745-1827) did a study in 1806 to analyze the bands. He concluded that hailstones, before they fall to the ground, may change elevation a number of times due to up- and downdrafts. As the temperature and moisture levels change, layers of ice accumulate on an "embryo" (nucleus) at different rates, thus forming the layers.

Have hailstones ever proven to be deadly?

Strong hails can be heavy and plummet at speeds that have been known to break windows, dent cars, damage roofs, destroy crops (to the tune of about a billion dollars annually in the United States alone), and, yes, even kill. In July 1953, for instance, 30,000 ducks were found dead after a hail storm in Alberta, Canada. In Montana, a July 1978 hail storm killed about 200 sheep.

In the United States, not many people have been killed as a result of hail. The last reported death was on July 30, 1979. A hail storm in Fort Collins, Colorado, killed an infant and injured about 70 other people. Storms in other, poorer regions of the world are more common, however, because poorly built shelters collapse, killing those inside. For example, in Sichuan Province, China, a fierce hail storm injured 9,000 people and killed 100 on March 22, 1986. A month later, that same year, 92 people died in Gopolganj, Bangladesh, with some hailstones reported to weigh over two pounds (three kilograms).

 
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