While things like tornadoes, flash floods and lightning are the deadliest aspects of severe weather, they all pale by comparison financially when it comes to hail. Each year, insured losses range from 8 to 14 billion dollars. Add in uninsured losses and it is probably almost double that!
Research into Hail Mitigation
As you can imagine, a lot of research is going into hail to try and mitigate as much of that loss as possible. For large fields of wheat, corn and soybeans there isn’t much you can do, but better shingles, car ports, glass and body materials can reduce the number to businesses, houses and cars. One of the big research projects is being done by the Insurance Institute of Business and Home Safety (IBHS). They have been studying the size, shape, density and hardness of hail across the country since 2012 and are gaining new insight into things that can be done to reduce losses. You may have seen or may encounter some of their field research “chase vans” in the central plains over the last several years (yes, it is possible to get paid to chase storms for large, wealthy companies!). All of their research into hail and other insurance-loss-causing episodes have led to a non-profit website to help homes and businesses prepare for severe weather. DisasterSafety.org is the result of their efforts so far.
Of course, the National Severe Storms Laboratory (NSSL) has been and will continue researching hail detection, warning and mitigation. Their latest findings can be found at: NSSL Research: Hail (noaa.gov)
Can you see hail on the radar? Absolutely!
One of the most revolutionary things to come from NSSL research is the implementation of dual polarization radar (called dual pol for short). When you polarize a radar beam into its vertical and horizontal components, it becomes extremely good at differentiating between heavy rain and hailstones. Before dual pol, there were tools that could be used to feel pretty confident that a dark red or purple area on a radar was hail vs. heavy rain, but dual pol makes it a certainty. Why? It all boils down to the shape of a raindrop. Believe it or not, raindrops are NOT tear-shaped like they are almost always depicted (there is a good reason they are depicted that way, but that is for another blog). As raindrops fall, they actually look more like a donut with the hole not fully punched out or a hamburger patty that you have made a dent on both sides in the center to prevent shrinkage while cooking. This means that raindrops are ALWAYS wider than they are tall. Rather significantly so. Hailstones, on the other hand, while almost never perfectly round tumble as they fall, so to a radar beam, they always appear perfectly round! Thus, if you look at the horizontal rays coming back to a radar vs the vertical rays, the horizontal rays will be significantly stronger than the vertical rays in rain, but exactly equal in hail. Pretty ingenious! Meteorologists use this to tell exactly where the rain is turning over to hail at the height of the radar beam. In the image above, the red near Searcy, AR indicates the hail.
Turning back to crop loss..
It is hard to get your mind around how much money is lost when a 160 acre field of wheat is mowed off by wind-driven hail. Just to give you an idea, all of those square “sections” of land that you see in the country, a mile on each side, are 640 acres. These sections also exist in “newer” portions of cities like Wichita. For example, an area bounded by Central, Tyler, 13th and Ridge is the exact same size as one of those country sections (all of those streets used to be country dirt roads!). So a quarter of that (like the land that Northwest High sits on) is 160 acres. A good field of wheat yields about 60 bushels of wheat per acre. The current price of wheat at an elevator is about $6.51 a bushel. Thus 6.51 x 60 x 160 = $62,496! Now, think about how wide and long a swath of hail under a Kansas thunderstorm can be and the miles and miles of wheat fields you drive past and you can see how this gets very expensive very fast!
One of the most used and most controversial methods of hail mitigation is cloud seeding. While cloud seeding is proven and evident in simple weather situations such as fog suppression over a runway or “hole punching” in a stratus layer of clouds, it becomes much less observable and easy to measure in a system as complex as a supercell thunderstorm. One of the hardest things to know is “would x have happened anyway” with or without seeding? The evidence is strong enough, and the financial losses are large enough that many counties, municipalities and states in the high plains of the US and Canada pay millions of dollars a year, which, even if it reduces hail loss by 1% more than pays for itself. More research is and will be done on just how effective it is, but for now its all we’ve got, so it will continue to be used. (This, of course, has implications for storm chasers, but that is for another blog.)
So, when the sky grows dark this spring and a thunderstorm moves through without a tornado that “only” produces hail and flooding, remember how many dollars are being lost that would have been fed into the Kansas economy!
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