Causes of Tornadoes

They come from powerful thunderstorms and appear as rotating, funnel-shaped clouds. Tornado winds can reach 300 miles per hour. They cause damage when they touch down on the ground. They can damage an area one mile wide and 50 miles long. Every state is at some risk, but states in "Tornado Alley" have the highest risk. Tornadoes can form any time of the year, but the season runs from March to August. The ability to predict tornadoes is limited.

The tornado reaches down out of a thundercloud as a huge, swirling rope of air. Wind speeds in the range of 200 to 300 mph are not uncommon. If the vortex touches ground, the speed of the whirling wind (as well as the updraft and the pressure differences) can cause tremendous damage. The tornado follows a path that is controlled by the path of its parent thundercloud, and it will often appear to hop. The hops occur when the vortex is disturbed. You have probably seen that it is easy to disturb a vortex in the tub, but then it will reform. The same thing can happen to a tornado's vortex, causing it to form and collapse along its path.

FEMA.gov tornado link for kids

How Tornadoes Work

Tornado Project Online

These towns were the main targets of the devastating winds. Between Gorham and Murphysboro, the forward speed was a record setting 73mph. No distinct funnel was visible through much of its path, yet for over 100 miles, the path width held uniformly at about three quarters of a mile.

After touching down 3 miles north-northwest of Ellington, Missouri, it killed a farmer. The funnel was very wide, a double tornado, or accompanied by downbursts as it enveloped Annapolis and a mining town called "Leadanna" 2 miles south of Annapolis. Two people were killed and 75 more were injured in that area. Losses in both towns totalled about $500,000. There were no injuries across most of Iron, and all of Madison Counties. The damage track was very wide; damage was F2 in intensity, and this may reflect a break in the tornado path, but with downburst damage connecting the tornado damage tracks, 5 miles south of Fredericktown. Only once more, near Princeton, Indiana, would there even be a minor hint that this event was a tornado or tornado/downburst family. Once out of the Ozark hills and onto the farmland of Bollinger and Perry Counties, the death toll quickly mounted near Lixville, Biehle, and Frohna. One child was killed in a rural wooden school, 5m N of Altenburg, Perry County. At least 32 children were injured in two Bollinger County schools. The event was probably a double tornado for three miles near Biehle. Eleven probably died in Missouri, although some lists have 13 deaths.

In Illinois, the devastation was at its worst. At Gorham, 34 people died as virtually all of the town was destroyed. Over half of the town's population was either killed or injured. Seven of the deaths were at the school. At Murphysboro, there was the largest death toll, within a single city, in US history. The 234 deaths included at least 25 in three different schools. All of these schools were brick and stone structures, built with little or no reinforcement, and students were crushed under falling walls. Murphysboro losses totalled about $10,000,000. Another 69 people died in and near Desoto, and the 33 deaths at the school was the worst in US tornado history. Parrish was devastated, with 22 deaths, as was the northwest part of West Frankfort, with $800,000 damage. About 800 miners were 500 feet down in a mine when the tornado struck. They knew there had been a storm, but they had lost electrical power. The only way to get out, and find out how their families had fared, was to go up a narrow escapement. Most of the demolished homes were miner's cottages, and many of the 127 dead and 450 injured were women and children. Also unprecedented was the rural death toll of 65 in Hamilton and White County. There were single deaths in three different rural White County schools. The normally weatherwise farmers were apparently unaware of what was bearing down on them. With such a great forward speed, and appearing as a boiling mass of clouds rolling along, rather than a widely visible funnel, the tornado gave these people too little time to react. Massive amounts of dust and debris also served to obscure the storm.

In Indiana, multiple funnels were occasionally visible, as the 3/4-mile-wide path of destruction continued with no letup. At least 71 people died in Indiana. The town of Griffin lost 150 homes, and children were killed on their way home from school. Two deaths were in a bus. Another stretch of rural devastation occurred between Griffin and Princeton, passing just northwest of Owensville. About 85 farms were devastated in that area. About half of Princeton was destroyed, and losses there totalled $1,800,000. The funnel dissipated about 10 miles northeast of Princeton. $16,500,000.