Ever since the 1800s farmers in the Midwestern United States have called hailstorms “the white plague.” And no wonder! In just a few minutes hail can devastate a farmer’s crop. The origin of the term is uncertain. It may be a Biblical reference to the plagues visited on Egypt, one of which was hailstones.
Hail most often occurs during thunderstorms, particularly the violent storms that occur in spring and summer. Hurricanes will often produce hail as well. In fact, meteorologists tell us that most thunderstorms have hailstones in the middle and upper levels of the clouds. Usually, the stones remain small, and melt before they fall to earth. The more intense a thunderstorm is, however, the more likely it is to produce hail big enough to reach the ground.
Hailstones start as tiny drops of water that the powerful updrafts found in thunderstorms lift to high altitudes where the cold causes them to freeze. This frozen droplet (called a “graupel”) is the seed around which the hailstorm will form. As it falls, it accumulates more water at lower altitudes. Then it is flung upward again and again by the violent winds, each time forming another layer of ice. A hailstone continues to add layer after layer until it finally becomes heavy enough to fall to the ground. If you cut a hailstone open, you can see the onion-like layers that reveal how this accretion process occurred. Most hailstones are not largepea-sized or even smaller. Occasionally much larger stones are formed and can be the size of golf balls up to as large as 6 inches in diameter. After one hailstorm in August, 2007 in Dante, South Dakota, giant hailstones left 10-12 inch craters in yards and one monster measured 5.25 inches in diameter.
Hail has sometimes have played a part in shaping history. In 1788, for example, a series of destructive hailstorms destroyed much of the year’s crops in France. The resulting food shortage worsened the plight of already impoverished peasants and is credited with helping incite the French Revolution. Even today, there is little farmers can do to protect crops from hailstones, other than to purchase hailstorm insurance. The danger isn’t limited to crops, either. A storm that produces golf-ball to softball sized hail can kill and injure livestock and even people caught out in the open.
The threat of hailstones isn’t limited to farming communities. In urban areas, large hail can do more than just leave craters in people’s yards. In 2005, a severe hailstorm and high winds in Jiangsu Province in eastern China killed seven people, injured hundreds, and caused millions in property damage. Three years earlier in 2002, an even worse storm in the same region of China killed 25 people. Large hail can shatter windows, down power lines, and cause extensive damage to cars and buildings.
The destruction and death that hail can cause certainly justifies its nickname, “the white plague.” It is wise to take weather alerts of possible hail very seriously and take shelter. A severe thunderstorm carries with it not only risk from lightening and high winds, but often of hail as well.
