|
Hail: Introduction
Watch out below! Hail is a unique hazard capable of producing extensive damage from the impact of falling objects. Most thunderstorms do not produce hail, and ones that do normally produce only small hailstones not more than one-half inch in diameter. However, hailstones can grow larger than the size of a golf ball before falling to the ground. On September 3, 1970, a thunderstorm in Coffeyville, Kansas produced a hailstone that measured more than 5 inches in diameter and 17 inches around, weighing 1.7 pounds.
 |
Photo Credit: W. Hunter/Park
City Daily News |
Hail is associated with severe thunderstorms. Powerful updrafts produce cumulonimbus clouds that tower tens of thousands of feet above the ground. Air temperature in the upper levels of these clouds may be -50°F or below. Hailstones grow as ice pellets, are lifted by updrafts, and collect supercooled water droplets. As they grow, hailstones become heavier and begin to fall. Sometimes, they are caught by successively stronger updrafts and are circulated through the cloud again and again, growing larger each time the cycle is repeated. Eventually, the updrafts can no longer support the weight of the hailstones. As hailstones fall to the ground, they produce a hailstreak that may be more than a mile wide and a few miles long. A single thunderstorm can produce several hailstreaks (Changnon and Ivens, 1987).
Hailstorms occur every year in Kentucky. Fortunately, most of these cause minimal damage. However, storms producing large hail and causing extensive damage are ingrained in the memories of many Kentucky residents. While it is not possible to prevent damage, efforts to mitigate the potential effects of hail can help property owners to minimize their losses.
|