Hail storm surprises Dallas residents - May 05, 1995 - HISTORY.com

The Dallas, Texas, area is hit by torrential rains and a severe hailstorm that leaves 17 dead and many others seriously wounded on this day in 1995. The storm, which hit both Dallas and Tarrant counties, was the worst recorded hail storm to hit the United States in the 20th century.

The storm came on a Friday afternoon, when warm weather had drawn many people to outdoor events in the area. It came on suddenly and many people had not yet sought shelter when tennis-ball-sized hail began to fall. Victims suffered broken bones, deep lacerations or bruises from the hail stones. The hail also broke windows, dented cars and trucks and destroyed crops. Air traffic throughout the country was delayed because of the sudden problems in Dallas. However, the hail was not responsible for the 17 people who lost their lives that day. Instead, it was the accompanying flash flooding that caused the 17 fatalities. Most of the deceased drowned after becoming trapped in their cars.

In order for hail to fall, there must be powerful updrafts of warm air combined with colder clouds. For that reason, hail storms virtually always occur in the late spring or early fall and in the afternoon. The warm air at the ground–heated from a full day of sun–rises and brings with it salt, dust and other particles. When these particles meet with the super-cooled water in a cloud, ice forms over them. As the particles continue to rise, bouncing as if on a trampoline within a towering cloud, the icy particles grow and grow until gravity sends them plunging to the ground. A large hail stone has layers of ice almost like an onion.

It is estimated that a two-pound hail stone requires a 400 mile-per-hour updraft in order to keep it in the air long enough to reach that size. Reportedly, items as large as frogs, worms and fruit have been swept up by updrafts and turned into hail.