Severe hailstorms cause an average of $1 billion USD in damage annually in the United States, with more active years such as 2016 crossing the $3 billion USD mark. In extreme cases, individual hailstorms have surpassed $2 billion USD in damage when impacting a densely populated metropolitan area. The impact to agriculture can be significant as well, but first, let’s take a look at some of the science behind these frozen projectiles.
Hail is a form of frozen precipitation which occurs when water droplets are suspended aloft inside a thunderstorm by its powerful updraft where air temperatures are well below freezing. The hailstones continue to slowly grow in size until they’re too heavy to be supported by the thunderstorm updraft and fall to the ground. The more intense the updraft of the thunderstorm, the longer the hailstones are held aloft, and the larger they become. The requirement of a powerful thunderstorm with the presence of a very strong updraft for large hail development explains why severe hail often accompanies other severe weather hazards such as damaging winds, flooding rains, and tornadoes. In the most severe cases, the updraft speed in these powerful thunderstorms exceeds 100 mph.
In the United States, hail is most common across the Central Plains, with Colorado, Nebraska, and Wyoming making up what is known as “Hail Alley”. Year-to-year results will vary however, with Texas, Illinois, Missouri, Minnesota, and Oklahoma leading the way in 2017 in damaging hail (greater than 1” diameter) reports. The map below displays all severe hail reports that occurred in 2017.
As severe hail requires the development of severe thunderstorms, the peak season for hail production coincides with peak severe weather season across the Great Plains, from March through October.
The largest hailstone ever measured fell in Vivian, South Dakota on July 23, 2010. The hailstone measured 8.0” in diameter and weighed nearly 2 pounds. It’s estimated that the hailstone fell at a velocity of approximately 200 mph. Hailstones from this storm destroyed roofs and vehicles, and left craters the size of coffee cans in the ground. The updraft strength in the Vivian, South Dakota hailstorm likely ranged from 160-180 mph.
The impact on agriculture from hail can be severe, but varies widely depending on the time of year that it occurs and the corresponding growth stage of the affected crops. Corn that is damaged by hail in May or June when the growing point is still below the soil surface stands a good chance of surviving with very little stand or yield loss. Hail damage sustained later in the summer can be more permanent, however, once the corn has entered its rapid growth stage.
Agrible alerts you if hail impacts one or more of your fields in your Agrible account. You will be notified of the time of event, size of hail, density, and duration — letting you know what fields you need to check first. With this information readily available, you can streamline the process of surveying your fields for hail damage and move forward with an insurance claim if necessary.