Guest Author - LeeAnn OLeary
When we hear the word tornadoes we often think of movies like "Twister" or "The Wizard of Oz". With the spring and summer months comes the chance for tornadoes. Tornadoes happen most often in the spring during the late afternoon or the early evening hours. But what exactly causes a tornado? What should you do if you hear a tornado is coming and which areas of the United States see the most tornado activity?
How a tornado forms
Tornadoes are very destructive and are usually very fast. A tornado can be over within a matter of minutes. It is amazing to witness the destruction that such a fast moving storm can cause. A tornado is a funnel shaped cloud. A tornado is caused by low, heavy cumbulonimbus clouds that touch the ground. The air pressure is also very low in the area of a tornado. A tornado can also form over a lake or ocean and then come on the land and cause damage. This type of tornado is called a waterspout.
The length of a tornadoes path varies and tornadoes usually only last a few minutes. Tornadoes have very strong winds and are rated on the Fujita or F scale which is based on the damage done by the tornado. The Fujita scale is F0 for a gale tornado with winds of 40-72 mph, F1 a moderate tornado with winds of 73-112 mph, F2 a significant tornado with winds of 113-157 mph, F3 a severe tornado with 158-206 mph winds, F4 a devastating tornado with 207-260 mph winds and a F5 or incredible tornado which has winds of 261-318 mph.
Which area of the U.S. sees the most tornado activity?
It is possible that any state could see a tornado but one area of the U.S. is most likely to see more tornadoes than most other states. Tornado alley is given this name for a very good reason. The states in Tornado alley include Oklahoma, Kansas, Nebraska, and parts of Texas. Tornado alley is the area that usually will see the most tornadoes in the U.S. The reason behind this is that the conditions in which to create tornadoes are most favorable in these areas. Tornado alley has cool dry air from the West which then collides with the warm moist air from the Gulf of Mexico.
How do you know if a tornado is coming?
If the weather conditions in your area are right for a tornado to occur a watch will be issued. When a tornado is happening or will happen soon a warning will be issued. Once a tornado watch is issued you should make sure to stay tuned to your local news or listen to the weather radio to keep up to date with the current conditions in your local area. When a warning is issued in your area you should immediately get to a safe spot.