During a thunderstorm, drafts of warm and cold air are constantly circulating up and down within the clouds. As a result, small drops of water are constantly being brought to high elevations, where they can freeze. These partially frozen drops begin to melt as they fall back toward the ground and may then refreeze as they are picked back up. Each cycle adds to the size and weight of the circulating ice pieces. When these multi-layered balls of ice become too heavy and drop to the ground, we call them hail.
"On some hailstones, you can actually see rings inside them which show they were cycled through the thunderstorm more than once," Dr. Dick Orville of Texas A&M University explained in a Q&A session published on the school's website. "What starts out as a tiny raindrop becomes a pea-size chunk of ice and some eventually get to be the size of baseballs or softballs."
The same conditions that lead to hail formation are also conducive to the development of tornadoes, although the presence of one is not always an explicit sign that there is a substantial risk of the other. What makes hail so destructive is that it has a lot of time to accelerate while falling from the clouds. Hail has been known to reach speeds above 100 miles per hour. Most hail storms move on quickly, but some can linger and cause a significant amount of damage.
$100 million price tag attached to recent storm reminds Colorado residents of threat posed by hail
A hail storm that hit southern Colorado in late May has already to led to auto and homeowners filing more than $100 million in insurance claims, according to the Rocky Mountain Insurance Information Association (RMIIA). About 10,000 people have reportedly filed property insurance claims, with almost double that number filing claims related to damaged vehicles.
A representative of State Farm Insurance told local news source KRDO that the company has continued to see dozens of new claims filed every day, weeks after the storm hit the area. Asked if he was surprised by the total value of insurance claims filed in connection with the hail storm, one resident said, "Not at all."
Colorado's Front Range is part of "Hail Alley," which receives more large hail than any other region in the world, according to the RMIIA. Residents of this area typically experience at least three "catastrophic" hail storms causing at least $25 million in insured damage each year.
During the last decade, hail storms have caused more than $3 billion in insured damage in Colorado. However, a number of other states face an ever greater risk from hail.
NOAA: Hail risk is most prominent in Texas
According to the National Oceanic and Atmospheric Administration (NOAA), more than 7,000 major hail storms hit the United States in 2012. Data from NOAA's Severe Storms database shows that Texas experienced the most storms, with Kansas, Nebraska, North Carolina and Oklahoma rounding out the top five. Earlier this year, the Texas Department of Insurance issued a warning to residents about the risks they will face during the spring and summer, including hail.
State Farm has also explored the state-by-state distribution of hail risk. The company reported that wind and hail damage caused more than $3.9 billion in losses for its policyholders during 2012. Unsurprisingly, Texas had the highest amount of insured damage. However, none of the other states referenced by the NOAA made the top 10. Of course, this may be more reflective of the distribution of State Farm's policyholders, rather than the severity of hail storms in different states.
No silver bullet for managing risk
The RMIIA notes that the damage caused by hail storms can range from "a few broken shingles to total destruction of buildings." Regardless whether all or part of a structure is damaged, properly developing replacement valuations will help avoid underinsurance.
There are roofing materials designed to be resistant to hail damage, but these cannot completely protect a structure from hail. Furthermore, using these durable materials can also affect the cost of replacing a roof if it is damaged. Any change in a structure's valuation can have an impact on the property owner's insurance premium.