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HAIL FAQs

The 3/4" size limit for hail is based on a 1952 study of the "smallest size of hailstones that cause significant damage at airplane speeds between 200 and 300 mph." Though this was based on DC-3 type aircraft, hail remains a significant hazard to aviation.

Yes. On April 4, 1977, a Southern Airways DC-9 crashed in New Hope, GA. Both engines of the plane ingested hail and lost thrust. The plane crashed onto the road and burst into flames. Two of the four crew members and 60 of the 81 passengers were killed; eight others on the ground were also killed.

My neighbors on both sides had hail damage to their roofs, and I did not. How is this possible? NSSL works to predict hail, we do not study hail damage from an engineering perspective. However, there are a number of reasons why your roof did not show damage. It is possible that your roof had better shingles, or newer shingles. The direction of your main roofline, the distance between the houses, whether or not the wind was driving the hail – all these can make a difference in the amount of damage you can receive.

Yes, many non-supercell storms produce golf ball size hail.

Understanding Damage and Impacts

Damage from hail approaches $1billion in the US each year. Much of the damage inflicted by hail is to crops. Even relatively small hail can shred plants to ribbons in a matter of minutes. Vehicles, roofs of buildings and homes, and landscaping are the other things most commonly damaged by hail.

Hail has been known to cause injury to humans, and occasionally has been fatal. The most deadly hailstorm on record occurred in India on April 30, 1988, killing 246 people and 1600 domesticated animals.

This hailstone measures nearly 4 inches across.

A large hailstone can cause serious injury. A hailstone the diameter of a baseball falls at a speed comparable to that of a pitched baseball - on the order of 100 mph! It's like being hit by a "beanball" thrown by a major league pitcher.

Windshield damaged by baseball-size hail

The NSSL-developed Hail Detection Algorithm identified a large hail event that pulverized the Dallas-Fort Worth area on May 5, 1995. Hail as large as 3.5 inches (grapefruit-size) was reported, and 109 people attending an outdoor celebration were seriously injured. The storm continued across the DFW Metroplex, killing 18 people in flash floods and doing $1.2 billion damage, most of it from hail.

Hail suppression

Since World War II scientists have tried many techniques to lessen the damage from hail storms. The most well-known technique involved "seeding" large thunderstorms with silver iodide. The theory was that the resulting small hail would probably melt and therefore not cause any damage. Unfortunately other experiments using this technique were not successful, and hail suppression remains elusive.

Another novel technique to supress hail was recently installed in a company parking lot by an auto manufacturer trying to protect its inventory of newly painted cars. Under certain thunderstorm conditions detected by the company's own radars, a cannon-like device will send sonic waves up to 50,000 feet in the air to keep hailstones from forming. Now they must wait for a hailstom to pass over the parking lot to test the device!  

HOW DOES NSSL CONTRIBUTE?

NSSL focuses their research efforts towards the prediction and detection of hail and hailstorms to give folks enough time to avoid the storm, seek shelter, and protect their property.

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