How does Oklahoma tornado start and what does it do?

Answer 1

Tornadoes in Oklahoma are largely the same as tornadoes that form elsewhere. Oklahoma is part of Tornado Alley, a region with an especially favorable setup for tornadoes. The sequence described below typically occurs during the spring.

In most cases for Tornado Alley, two or three air masses come together. The first is a warm, moist air mass form the Gulf of Mexico (maritime tropical). Second is a cool air mass from Canada (continental polar), which pushes into the maritime tropical air mass, forming a cold front. Sometimes a mass of warm, dry air from the Rockies (continental tropical) pushes in to the maritime air mass, forming a dry line. In some cases both a cold front and dry line develop, sometimes intersecting to form a triple point.

In any case, these boundaries between air masses induce lift on the maritime tropical air mass, which can trigger the development of thunderstorms. However, a layer of stable a little more than a mile above the ground, called a cap, air initially keeps the storms from developing, allowing instability to build underneath it until storms break through it and develop explosively, growing very powerful. A second, even more important factor is wind shear, which is a change in speed and direction of the wind with increasing altitude. This wind shear has three effects. First, the stronger winds at high altitude enhance the vertical pressure gradient, causing the updraft of a storm to strengthen, which in turn strengthens the storm. Second, it tilts the storm so that the updraft and downdraft separate and do not interfere with each other, allowing the storm to grow stronger still. Finally, the wind shear causes the storm, and most notably the updraft, to start rotating. At this point the thunderstorm is called a supercell and the rotating part of the updraft is called a mesocyclone. The rotation in the mesocyclone is what leads to a tornado.

How the mesocyclone produces a tornado is still not fully understood, but the leading theory is this. Rain induces a downdraft at the rear portion of the supercell. If it is not too cold this downdraft will wrap around the mesocyclone and essentially squeeze it. Causing it to tighten and extend toward the ground. Because of the tightening the rotation accelerates into and intense vortex, and a tornado is born.

In terms of what they do, many tornadoes in Oklahoma tear across open countryside, causing little or no damage. In some cases farms may be destroyed, or a weak tornado may cause moderate damage to a city or town. Unfortunately, in some cases strong tornadoes hit communities, causing major damage and even destroying whole neighborhoods and claiming lives.