Oh, Hail

Hail and the damage it can do

April 30, 1888: The deadliest hailstorm in recorded history strikes outside Delhi, India. The storm dropped orange-sized hailstones on Moradabad and killed 246 people; thousands of farm animals also perished. The storm hit around midday but with the thick cloud cover, it was reported to be as dark as night. There was no advance warning system in place, so the farmers of the community were out working the fields. Most people were killed instantly. By the time the storm abated, there were places with an accumulation of hail up to two feet deep.

Hailstones are formed by ice crystals being tossed up and down inside storm clouds. Most hail measures between a quarter-inch to nearly 6 inches in diameter. Usually hail is less than an inch in diameter, but stones can grow as large as tennis balls. As the ice pellets move within the cloud, they increase in size and weight. They need not be round and need not even be smooth, but can be oval, ovoid, or crystalline in shape.

The longer the ice stays in the growth region, the larger the supercooled liquid becomes by coalescing with other raindrops in the vicinity. The supercooled liquid freezes on contact with some form of nuclei, such as dust or dirt. Sweeping through updrafts and downdrafts for longer periods of times, along with the actual size of the storm cloud, allows for huge hailstones to be formed. Latent heat can be released, causing melting of the outer shell which can then adhere to other, smaller hailstones before refreezing.

The largest hailstone measured in the US was 5.6 inches in diameter or 17.5 inches in circumference. There were only two 20^th century human deaths in the US due to hail. However, animals were not so lucky. There were two storms in quick succession in Alberta, Canada, killing over 75,000 ducks between them. Hail also damages crops. In 1788, many crops outside Paris were damaged by hail and the resultant food shortage led, in part, to the French Revolution. Hail is also damaging to cars or trucks left out in storms resulting in denting to the body and cracked windshields. As hailstones drop from 30,000 feet, they can reach speeds up to 120 mph.

“Send therefore now, and gather thy cattle, and all that thou hast in the field; for upon every man and beast which shall be found in the field, and shall not be brought home, the hail shall come down upon them, and they shall die.” – The Bible

“Unless God send his hail / Or blinding fire balls, sleet or stifling snow, / In some time, his good time, I shall arrive.” – Robert Browning

“Thunderstorms represent the primary threat.” – Bob Rice

“When all is said and done, the weather and love are the two elements about which one can never be sure.” – Alice Hoffman

Also on this day, in 1803 the US completed the Louisiana Purchase transaction.