NEW TECHNIQUES TO STUDY HAIL
By Meteorologist Randy Mann
Article published on August 14, 2024
Thunderstorm season continues in across the U.S. east of the Rockies. For the 2024 season, there have been 1,344 tornadoes spawned from severe thunderstorms, compared to an annual average of approximately 1,200. Scientists claim that 2024 was one of the most active tornado seasons in history, especially during the spring. For example, in May, there was at least one twister reported in the U.S. nearly every day.
On August 13, there was a tornado warning in eastern Idaho that lasted for about an hour. The regions that were under the warning was Jefferson, Butte, Bonneville and Bingham counties. Radar data was indicating the possibility of tornado development on that afternoon, but there were no reports of one that formed. However, there were reports of hail from the severe storm last week.
Hail will consist of balls or irregular lumps of ice that will form in thunderstorm-type clouds called cumulonimbus. It forms when there are strong, upward motions of air and the water in the cloud will freeze as moves up into the cloud. With updraft wind speeds as high as 110 miles per hour, the hailstone can move up and down in the cloud. As it descends through the cloud, it receives another layer of supercooled water droplets. As it moves up the cloud, the water droplet freezes once again, and the hail stone becomes bigger. The ball of ice falls to the ground when it becomes too heavy in the cloud.
According to Wikipedia, the heaviest hailstone was 2.25 pounds and fell at Gopalganj District in Bangladesh on April 14, 1986. The largest diameter officially measured was 7.9 inches at Vivian, South Dakota on July 23, 2010. That particular hailstone had a circumference of 18.622 inches and weighed 1 pound 15 ounces. But, the largest circumference, the distance around the ice, was 18.74 inches, which fell at Aurora, Nebraska on June 22, 2003.
In the U.S., most of the thunderstorms will occur in Florida. However, most of the hail that is reported is often found in Nebraska, Colorado and Wyoming. These states will average approximately 7 to 9 hail days per year. According to NOAA, China, Russia, India and northern Italy will also experience damaging hailstorms. Hail research and forecasting has been increasing in recent years to better understand and predict these damaging storms. A research paper that was published in the Journal of the Atmospheric Sciences is using the various sizes and shapes of hailstones to help predict their pathways, speed and impact.
Like snowflakes, no two hailstones are completely alike. Many will often have odd shapes rather than a perfect sphere. Hailstones can almost be nearly flat or have spikes originating from the center of the stone. According to an article by phys.org, by examining and modeling the different shapes of hail, scientists may ultimately help predict in “real-time” how big a hailstone may be during a major storm and where it will fall.
To help with these new technologies of hail prediction, frozen hailstones have been collected at a University of Queensland library located in eastern Australia. Hundreds of samples have been collected that were scanned using 3D technology. It’s essentially a “hailstone library,” which is a relatively new science dedicated to forecasting severe weather.
