Tornadoes

=   TORNADOE﻿S    =

= = = Introduction: = A tornado is a violent, dangerous, 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 a twister or a cyclone**.** Each year about a thousand tornadoes touch down in the US and Canada. Only a small percentage actually strike occupied buildings, but every year a number of people are killed or injured.

Causes of Tornadoes:
Tornado conditions are caused when diffrent tempratures and humidity meet to from thundercloudes.In the United States warmer winds from the Gulf of Mexico move northward in spring and summer, meeting colder ,dry Canadian winds moving southward. The place where two winds meet is called a dry line.High dry air coming from the north piles on top of low moving,most Gulf air at a height of over1,0000 feet.The warm southren winds try to rise, but the cold northern air blocks them.This clash causes the warm traped air to rotate horizontally between the two air masses.At the same time the sun heats the earth below,warming more air that continues to dry and rise.Finally,the rising warm wind become strong enough to force itself up through the colder air layer. When this occurs the cold airon the top begins to sink,sending the rising warm wind spninigupward.The warm winds rotate faster in a high column.When the updraft is strong column can rise to heights 10 miles or more twisting at speed of 100 miles an hour.The rotating wind produce strong sorm clouds about 70,000 feet high some time spreading10 miles wide. = : Types Of Tornadoes : = Tornadoes come in various sizes and can form in different locations. They can range in shape from narrow and rope-like, narrow or fat cylinders, or be cone or wedge-shaped. They also form in different situations. Below are some of the variations.

A:Supercell Tornadoes:
Some of the most violent tornadoes develop from supercell thunderstorms. A supercell thunderstorm is a long-lived thunderstorm possessing within its structure a continuously rotating updraft of air. These storms have the greatest tendency to produce tornadoes, some of the huge wedge shape.

The tornadoes that accompany supercell thunderstorms are more likely to remain in contact with the ground for long periods of time -- an hour or more -- than other tornadoes, and are more likely to be violent, with winds exceeding 200 mph.

B:Gustnado:
Weak and usually short-lived, a gustnado forms along the gust front of a thunderstorm, appearing as a temporary dust whirl or debris cloud. There may be no apparent connection to or circulation in the cloud aloft. These appear like dust devils.

C:Waterspout:
A waterspout is a tornado over water. A few form from supercell thunderstorms, but many form from weak thunderstorms or rapidly growing cumulus clouds. Waterspouts are usually less intense and causes far less damage. Rarely more than fifty yards wide it forms over warm tropical ocean waters, Although its funnel is made of freshwater droplets condensed from water vapor from condensation - not saltwater from the ocean. Waterspouts usually dissipate upon reaching lan = Damages: = =media type="youtube" key="7r2X8odaUtg?version=3" height="357" width="448"= [] 

A tornado is a very powerful and damaging windstorm. It can rip apart houses, throw things above the clouds, and do nearly anything destructive. Tornadoes, whether they are a few yards wide or a mile wide, will sweep many miles of land destroying everything in their paths. However, tornadoes are also capable of moving objects without causing any damage whatsoever. This, unfortunately, is rare. The government can spend millions of pounds/dollars on repairs every year. For example, the F5 tornado of Oklahoma city ( 3rd may, 1999) cost around 1 billion dollars in repairs. Another example of such devastating damage is the Tri state tornado, which nearly wiped out two tow.

The above information only applies to the very strongest of tornadoes, those rated EF4 and EF5. While tornadoes this strong are devastating they are also rare. EF2 and EF3 tornadoes still cause significant damage. They can tear the roofs and walls from houses though they typically leave homes at least partially intact. They can flip cars, derail trains, and obliterate trailer parks. The weakest and most common tornadoes are rated EF0 and EF1. These tornadoes can knock over trailers, break tree limbs partially remove roof surfaces and siding. These tornado often have short damage paths less than a mile long.

Read more: [] = Safety tips: = One of the most important things you can do to prevent being injured in a tornado is to be Alert to the onset of severe weather. Most deaths and injuries happen to people who are unaware and uninformed. Young children or the mentally challenged may not recognize a dangerous situation. The ill, elderly, or invalid may not be able to reach shelter in time. Those who ignore the weather because of indifference or overconfidence may not perceive the danger. Stay aware, and you will stay alive! If you don't regularly watch or listen to the weather report, but strange clouds start moving in and the weather begins to look stormy, turn to the local radio or television station to get the weather forecast. Check [|The Weather Channel] for additional information, or if you have trouble getting up-to-the-minute forecasts on a regular radio, then a NOAA weather radio"is a wise investment. If a tornado watch is issued for your area, it means that a tornado is "possible." If a tornado warning is issued, it means that a tornado has actually been spotted, or is strongly indicated on radar, and it is time to go to a safe shelter immediately. Be alert to what is happening outside as well. [|even if no funnel cloud is visible]. > Tornadoes are very dangerous storms.They strike with very little warning.Most of the timethey move in with a thunderstorm,and when they are finally seen it is too late.The out side of funnel-shaped wind move at speed
 * = Conclusion: =
 * of 100KM per hour.In only a few minutes,these winds can cause a disaster.The only defence is to be on to
 * look for a tornado .If a' twister' is spoted the tornado warning goesout.every one should take cover in a cellar

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