Costliest Hailstorm in US History

Destructive Storms in Kansas and Missouri on April 10, 2001

Oct 7, 2008

Known as the Tri-State Hailstorm or Kansas City Hailstorm, a supercell storm in Kansas produced hail stones as big as golf balls and baseballs!

Hail usually falls to the ground in the form of small pellets but there are rare occasions when hailstones can be very large. When large pieces of ice are falling from the sky at fast speeds, it is a recipe for disaster.

How Hail is Formed

Thunder storms are a mixture of updrafts of warm air and downdrafts of cold air. Hail is formed when water droplets are picked up by the updrafts and carried upwards to where the air is at freezing level. The water droplets then freeze and are carried down by the cold downdrafts.

Sometimes the frozen droplets thaw out as they reach the warm air at the bottom of the thunderstorm. Other times, the droplets are still half-frozen and are forced up again to the freezing level and more ice forms on the droplet. Then the droplets fall again. As this process repeats, the frozen droplets get too heavy and eventually fall to the ground as hail.

According to the National Weather Service, “hail causes $1 billion dollars in damage to crops and property each year.”

Thunderstorm and Tornado Activity April 10, 2001

A series of rain showers and thunderstorms had moved though Missouri and Illinois during the morning and afternoon of April 10, 2001. As a result, the cool air from the thunderstorms had formed a west to east wall situated south of Interstate 70. It stretched from western Missouri into southwest Illinois.

In the afternoon of April 10, 2001, a supercell thunderstorm developed over eastern Kansas and it moved east along this wall of cool air. This storm produced widespread hail and tornadoes along its track. There were reports of hailstones ranging from 1 ¾ to 2 ¾ inches in some locations.

In addition, tornadoes were spawned in Missouri and a series of thunderstorms, hail storms and tornadoes continued until the following day. The worst was a F3 tornado that swept 75 miles from Kansas City, Missouri to Des Moines, Iowa.

Damage Caused by the Tri-State Hailstorm April 10, 2001

There were numerous reports of golf ball to baseball sized hail in both Columbia and the northern suburbs of St. Louis. Almost every home and business in Northern St. Louis County was damaged by hail, including 22 planes at Lambert International Airport.

During an 8-hour period on April 10, 2001 the supercell deposited hailstones ranging from 1 inch to 3 inches along a path of 363 miles.

As reported in the August 2003 Monthly Weather Review prepared by the American Meteorology Association, “the damage to St. Louis and Kansas City was $1.5 billion. Damage done in a 2-day period by the Tri-State Hailstorm and hailstorms in adjacent areas totaled $1.9 billion, becoming the ninth most costly weather catastrophe in the US since property insurance records began in 1949.”

To visualize the impact of large-sized hail, picture a baseball being dropped from an airplane flying at 30,000 feet. The projected speed of this baseball as it hits the ground would be approximately 120 mph. It is understandable why hail can cause severe damage.

The copyright of the article Costliest Hailstorm in US History in Lightning & Storms is owned by Maureen K. Fleury. Permission to republish Costliest Hailstorm in US History in print or online must be granted by the author in writing.