John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
A ferocious storm this weekend left a trail of hail 75 miles long in Alberta.
The city of Calgary lucked out during Saturday's foul weather, but the commuter town of Airdrie about 18 miles north did not – it got pounded like a gun-range target by a brutal hailstorm that left the icy land stain you see above.*
The National Weather Service office in Gaylord, Michigan, tweeted the image today with the appropriate description of "amazing." The hail swath measured about a half-mile wide but stretched on for 75 miles, to believe one weatherhead's account at Ontario Storms, which also has this nutso footage:
"Up until I saw that video, I never knew hail could fall as thick as snow complete with blowing and drifting," says the person who posted it. "Unreal." The dude who filmed that clattering hell-scape said that within 15 minutes, the ground was mired in a full foot of hailstones.
Fate is smiling on Airdrie, whose steer-wrestling residents number around 43,000, as I can't find any reports of injuries. If this kind of hailstorm were to have swept over Calgary, with an urban population above 1 million, you could expect to see the kind of carnage that results in these punishing meteorological events – car windows busted out, businesses shut down from damage, limbs snapped and noggins bruised. During nasty hailstorms in the St. Louis region in April 2012, for instance, hail smashed vehicles and broke the arm of one man; 100 people were injured and one was killed when a tent fell on them during a post-Cardinals game celebration.
Hail swaths like this weekend's can get so big that their vegetation damage is detectable from space. If you want to know more about these titanic sky-beatings, here's a good summary from the University Corporation for Atmospheric Research in Boulder, Colorado:
Hail falls along paths scientists call hail swaths. These vary from a few square acres to large belts 16 kilometers (10 miles) wide and 160 kilometers (100 miles) long. Swaths can leave hail piled so deep it has to be removed with a snow plow. In Orient, Iowa, in August 1980, hail drifts were reported to be 2 meters (6 feet) deep. On 11 July 1990, softball-sized hail in Denver, Colorado, caused $625 million in property damage, mostly to automobiles and roofs. Forty-seven people at an amusement park were seriously injured when a power failure trapped them on a Ferris wheel and they were battered by softball-sized hail.
Hail also does a great deal of damage to crops. U.S. costs run into hundreds of millions of dollars annually. While hailstones have been found weighing as much as 0.75 kilograms (1.67 pounds), even much smaller hail can destroy crops, slicing corn and other plants to ribbons in a matter of minutes. Farmers cope with the hail hazard by purchasing insurance. Illinois farmers lead the United States in crop-hail insurance, spending more than $600 million annually.
* The original wording of "land scar" implied this was damage caused by hail, when it in fact is a bunch of hail piled on the ground