Though the US tornado season usually in begins in earnest from March and continues till June, things had been a little quiet this year, thanks to a cooler spring that lasted all the way through mid-May, keeping the twisters at bay. But as the temperatures and humidity have risen, the tornadoes have emerged with a deadly vengeance.

The first twister zipped through northern Texas on Wednesday May 15th, killing six people and injuring dozens of others. Then on Sunday, May 19th, a massive storm system moving through the plains and the Midwest region, resulted in tornadoes in Kansas and Iowa and finally, came the deadliest one of all - A massive tornado that struck right outside Oklahoma city on Monday, May 20th.

Measuring 1.3 miles wide the tornado landed at 2.56pm and quickly zipped across a largely undeveloped area of Newcastle, before traveling about ten miles to the populated Oklahoma suburb of Moore at a speed exceeding 200mph, razing down everything that came in its path.

When it finally lifted up at 3.36 pm, the tornado had traversed 17 miles starting 4.4 miles west of the city of Newcastle and ending 4.8 miles east of the city of Moore, where it flattened entire neighborhoods including the town's medical center and five schools. Among the worst hit were Plaza Towers Elementary and Briarwood Elementary. While the kids at Briarwood all miraculously survived, even though the school did not, the kids at Plaza Towers were not as lucky. Seven drowned when the basement inside which they were seeking shelter, flooded.

While officials are still looking through the rubble hoping against hope to find survivors, it appears as though this deadly tornado which has been categorized as an E-F5 (the maximum on the Fujita Tornado Scale), has injured 237 people and killed at least 24 people including, nine children.

This is not the first time the people of Moore have suffered through a giant twister - In 1999, a tornado of the same magnitude devastated the area, killing more than 40 people and causing damages of over $1 billion USD - One of the costliest in US history. If experts are correct, the damage caused by the most recent tornado will most likely exceed that.

This of course, is just the beginning of the season, which means that the residents of 'Tornado Alley' will most likely be subjected to additional twisters before the season ends in June. The silver lining in this otherwise dire situation, is that unlike the last two years, the season has begun late and so there will hopefully be fewer of them this year.

In 2011, the worst year on record for twisters, the first tornado hit on New Year's day and then to continued well into June. 550 people lost their lives, while another 5,400 were injured. The storms destroyed property worth $10 billion USD the most ever, in US history. The year will also go down in the record books for the most tornadoes in a single day (211) and, a single month (758).

Unfortunately, there is no way to forecast how bad the tornado season will be. That's because unlike blizzards and hurricanes, which take time to develop and spend hours lumbering across, tornadoes are small and quick, making predictions so difficult, that even a 16 minute warning, which is what was given to residents prior to this most recent disaster, is considered good!

What Are Tornadoes and How Do They Form?

A tornado is a very powerful rotating column of air that starts from the bottom of a thunderstorm cloud and extends all the way down to the ground. They form only during very severe rotating storms, called supercells that occur when cold dry polar air comes in contact with warm moist tropical air.

As the warm air rises, winds around the storm cause it to rotate and form a funnel. The air in the funnel spins faster and faster, creating a low-pressure area, which sucks in even more air and sometimes, even objects. While ordinary thunderstorms last between 30-60 minutes, supercells develop many updrafts and downdrafts and can live on for hours.

While tornadoes occur all over the world, the US gets the most - About 1,200 a year. The worst hit area is a stretch of land known as 'Tornado Alley' that extends from Texas to South Dakota. Here, the dry air off the Rocky Mountains meets warm, moist air from the Gulf and the cold Arctic air from the north - Perfect conditions for storms that are powerful enough to turn into tornadoes.