10 APRIL 2001

A complex of showers and thunderstorms moved through parts of Missouri and Illinois during the morning and afternoon hours on April 10, 2001. The cool outflow from the thunderstorms created an east-to-west oriented boundary just south of Interstate 70 from western Missouri into southwest Illinois. Later in the afternoon, a supercell thunderstorm developed over eastern Kansas and moved east along this boundary. This supercell thunderstorm produced widespread destructive hail along its track with numerous reports of golfball 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 the damaging hail, including 22 planes at Lambert International Airport.  In addition to the hail, tornadoes were reported in Johnson and Pettis counties before the storm entered the NWS St. Louis county warning area with brief tornado touchdowns occurring 3 miles north of California, near Fulton, Wright City, Wentzville, Lake St. Louis, and Granite City.

Meteorologists at the National Weather Service Office in St. Louis have studied this storm and concluded that it was the costliest hail storm in history with estimated damages near 2 billion dollars.    


The surface map analysis from 11:00 AM on April 10, 2001. A low pressure center is located over western Kansas.  A stationary front extends east from the low through Missouri and Illinois.  An outflow boundary from earlier convection is located south of the main stationary front.


The Preliminary Storm Report

The Preliminary Damage Survey

Damage Survey Photos and Tornado Tracks

SCIENTIFIC PAPER: The Historic Missouri-Illinois High-Precipitation Supercell of 10 April 2001 (PDF)

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