In March 2012 around 100 tornadoes marched their destructive path across America, sending out a warning of possibly another devastating season. 175 mph winds saw the total destruction of four towns across Indiana. Twelve deaths were reported from Henrysville.
In April 2011 the United States experienced 600 tornadoes in just one month, the highest number since records began being kept in 1950. There was a record payout of $26 billion for ‘The Year of the Tornado’. People began speculating that 2012 could become ‘The Year of the Tornado II’
A tornado is formed when cold air forms above warm moist air and the wind is forced to travel in different directions at different heights, creating extreme forces.
Many believe that tornadoes, or rotating thunderstorms, form when moist Gulf air meets with cold Canadian air and dry air from the Rockies. However, many scientists say this is a gross over simplification.
Governor, Robert Bentley, says “One thing that brings those elements together is strong jet stream, especially if it comes from the west or south-west.”
During April 2011 the jet stream dipped south over the south-western United States, sending strings of storms over the southern states for weeks on end. This kind of sustained pattern occurs only two or three times a century.
In order for a vortex, or funnel cloud, to be classified as a tornado, it must be in contact with the ground and the cloud base. Tornadoes can last from just a few seconds to more than an hour. The average time is usually less than 10 minutes.
Tornadoes are rated on the F-scale, which is the degree of damage relating to the intensity of the wind. While there has been much discussion about attempting ways to weaken tornadoes, in practice this is not possible for a variety of reasons.
Nineteen American states are in what officials call ‘Wind Zone IV’. That is areas that experiences the most consistent and strongest tornado activity. These states include large populations in Texas, Illinois, Ohio and Michigan.
The only real protection from tornadoes is underground bunkers, or a safe room, that can withstand wind and windborne debris travelling at up to 250 miles per hour and extensive weather forecasting systems. On average 62 people are killed by tornadoes each year, but more than 480 deaths were reported in the 2011 tornado season, of April through July, in the United States of America.
The major problem is that many people have stopped taking tornado warnings seriously, as not many weather systems actually turn into violent monster tornadoes. In fact violent tornadoes are very rare and there can be 100s of warnings at any given time across a wide area.
Tornadoes are not unique to the United States, however the States have more tornadoes than any other country, due to the flatness of the terrain of ‘Tornado Alley’ and the effect of a strong jet stream, with wind speeds in excess of 250 kph.