Tornadoes are more common in the U.S. than in any other country. There are up to 1,200 tornadoes per year, four times more than in Europe. Violent tornadoes occur more often in the U.S. in comparison to other countries. Tornadoes are known to form at a lower or higher intensity in the United States.
Via weather radios and tornado alerts, this phenomenon can be forecasted, as meteorologists, by spotting potential severe weather conditions, would help at issuing a warning. As of recently, the Doppler radar helps scientists identify a circulation or cyclonic development in the storm. Due to their intensity and size, there are only a few storm observations. However, more thorough information has been gathered by those who have been chasing the storm.
The areas most exposed to tornadoes are as follows: the southern U.S., the Mississippi Valley, the Midwest, the Great Plain and the Rocky Mountains. Twisters tend to be less frequent in the northeastern states. Tornado Alley has been coined as a denomination for an area prone to tornadoes. Unofficially, this area stretches from North Texas to Canada. The core of this area would be Kansas, Oklahoma and Northern Texas. Dixie Alley is yet another region where tornadoes are prone to occur, stretching across the southern U.S., and the central and northern regions of Alabama and Mississippi. Florida is a state where tornadoes usually occur. Nevertheless, tornado outbreaks in Florida are of a lesser intensity than those that occur in other states.
Referring to the time of the year when tornadoes strike – they are more common in spring, and less likely to strike in winter. In spring, usually cooler air collides with warmer air, resulting in thunderstorms. Tornadoes may also be caused by tropical cyclones, which occur in late summer or the beginning of autumn. Thunderstorms that are capable of spawning tornadoes form when the temperature reaches its peak (when it’s at its highest point), usually from 4:00 p.m. to 7:00 a.m.
Tornado season, colloquially known, is from March till June, but violent tornado outbreaks are known to occur at any time in the United States. For instance, in November, 1992, in Indiana, a twister injured nine people. Yet another non-seasonal tornado happened on December 9th, 1991, when a tornado outbreak struck in Illinois.
During winter, tornadoes usually strike in the Southeastern and Southern United States the most, even though this is not a general rule, as they could hit other regions as well. In February 2008, 84 tornadoes occurred during the outbreak, whereas the storm had produced several twisters in heavily populated regions: Jackson, Tennessee, the Memphis and the Nashville metropolitan areas. Hundreds were injured and 57 people were killed across several counties.
To reiterate, tornadoes hit specific areas of the U.S. during specific seasons. In winter, twisters are detected in the Southern U.S. and in the states near the Gulf of Mexico. This happens because of cold air reaching its limit of expansion over the Gulf Coast. In spring, the hot air moves back into the Gulf Coast. Thus, tornado frequency reaches its peak in April, as the mass of cold air is pushed from the Gulf States into the Southeastern states.
At the beginning of summer, masses of warm most air traverse into the Midwestern states and Great Plains. In May and June, tornado activity is the highest in the southern Great Plains. Moreover, the air mass traverses the Great Lakes region and Northern Great Plains – thus, tornado activity is at its peak yet again across these areas, in summer. However, during late summer and early fall, tornado activity tends to diminish in the U.S. Despite thunderstorms, this phenomena isn’t severe enough to cause twisters.