Tornado

A tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as twisters or cyclones, although the word cyclone is used in meteorology, in a wider sense, to name any closed low pressure circulation. Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust. Most tornadoes have wind speeds less than 110 miles per hour (180 km/h), are about 250 feet (80 m) across, and travel a few miles (several kilometers) before dissipating. The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (480 km/h), stretch more than two miles (3 km) across, and stay on the ground for dozens of miles (more than 100 km).

Various types of tornadoes include the landspout, multiple vortex tornado, and waterspout. Waterspouts are characterized by a spiraling funnel-shaped wind current, connecting to a large cumulus or cumulonimbus cloud. They are generally classified as non-supercellular tornadoes that develop over bodies of water, but there is disagreement over whether to classify them as true tornadoes. These spiraling columns of air frequently develop in tropical areas close to the equator, and are less common at high latitudes. Other tornado-like phenomena that exist in nature include the gustnado, dust devil, fire whirls, and steam devil; downbursts are frequently confused with tornadoes, though their action is dissimilar.

Tornadoes of 2012

This page documents the tornadoes and tornado outbreaks of 2012. Extremely destructive tornadoes form most frequently in the U.S., Bangladesh and Eastern India, but they can occur almost anywhere under the right conditions. Tornadoes also appear regularly in neighboring southern Canada during the Northern Hemisphere's summer season, and somewhat regularly in Europe, Asia, Argentina, and Australia.

There were 939 tornadoes confirmed in the U.S. in 2012. 86 fatalities have been confirmed worldwide in 2012: one each in Poland, Japan and Italy, three in New Zealand, five in Indonesia, six in Turkey and 69 in the United States.

Synopsis

The year began with an unusual number of tornadoes during January 2012. The first major tornado outbreak occurred on January 22–23, when a spring-like system moved across the southern Mississippi valley, producing at least two dozen confirmed tornadoes across Arkansas, Kentucky, Mississippi, Tennessee, and Alabama. As a whole, January was the third most active on record, behind 1999 and 2008. Despite this, a significant contrast in activity occurred for the month of February. Despite a slow beginning, the month of February ended with a significant tornado outbreak on the 28th and 29th with a strong EF4 doing significant damage and killing eight in Harrisburg, Illinois. Another ramp-up in activity occurred in early March, with one of the largest outbreaks ever recorded in the United States for that time of the year. This outbreak produced 160 reported tornadoes, and affected areas across Indiana and Kentucky in particular. Using the adjusted preliminary tornado count (85% of the total preliminary reports in order to remove overcount), 2012 attained record tornado activity on March 23 with 319 reports, eclipsing the previous record of 317.

Tornadoes of 2011

This page documents the tornadoes and tornado outbreaks of 2011. Extremely destructive tornadoes form most frequently in the U.S., Bangladesh and Eastern India, but they can occur almost anywhere under the right conditions. Tornadoes also appear regularly in neighboring southern Canada during the Northern Hemisphere's summer season, and somewhat regularly in Europe, Asia, and Australia.

There were 1,700 tornadoes confirmed in the U.S. in 2011. 2011 was an exceptionally destructive and deadly year for tornadoes; worldwide, at least 571 people perished due to tornadoes: 12 in Bangladesh, two in South Africa, one in New Zealand, one in the Philippines, one in Russia, one in Canada and 553 in the United States (compared to 564 U.S. deaths in the prior ten years combined). Due mostly to several extremely large tornado outbreaks in the middle and end of April and in late May, the year finished well above average in almost every category, with six EF5 tornadoes and nearly enough total tornado reports to eclipse the mark of 1,817 tornadoes recorded in 2004, the current record year for total number of tornadoes.