How do tornadoes form? – James Spann

They call me the tornado chaser.

When the wind is up and conditions are right, I get in my car and follow violent storms.

"Crazy," you say? Perhaps, but really Ichase these sky beasts to learn about them.

I want to share with you what I know.

Tornadoes are rapidly rotating columnsof air that form inside storms that connect with the ground viaa funnel of cloud.

When that happens, they tear across the Earth, posing a huge threat to life and property.

Because of this, there's a great dealof research into these phenomena, but the truth is, there's still a lotwe don't know about how tornadoes form.

The conditions that may give rise to one tornado won't necessarily cause another.

But we have learned a lot sincepeople first started recording tornadoes, like how to recognize the signswhen one is brewing in the sky.

Are you coming along for the ride? Tornadoes begin with a thunderstormbut not just any thunderstorm.

These are especially powerful, toweringthunderstorms called supercells.

Reaching up to over 50,000 feet,they bring high force winds, giant hailstones, sometimes floodingand great flashes of lightning, too.

These are the kinds of stormsthat breed tornadoes, but only if there are also veryspecific conditions in place, clues that we can measure and look out forwhen we're trying to forecast a storm.

Rising air is the first ingredient neededfor a tornado to develop.

Any storm is formed when condensation occurs, the byproducts of the clouds.

Condensation releases heat, and heat becomes the energy that driveshuge upward drafts of air.

The more condensationand the bigger the storm clouds grow, the more powerful those updrafts become.

In supercells, this rising airmass is particularly strong.

As the air climbs, it can change directionand start to move more quickly.

Finally, at the storm's base,if there is a lot of moisture, a huge cloud base develops,giving the tornado something to feed off later,if it gets that far.

When all these things are in place,a vortex can develop enclosed by the storm, and forming a wide, tall tube of spinningair that then gets pulled upwards.

We call this a mesocyclone.

Outside, cool, dry, sinking air starts to wrap around the back ofthis mesocyclone, forming what's known as arear flank downdraft.

This unusual scenario creates a stark temperature difference between the air inside the mesocyclone,and the air outside, building up a level of instabilitythat allows a tornado to thrive.

Then, the mesocyclone's lower partbecomes tighter, increasing the speed of the wind.

If, and that's a big if,this funnel of air moves down into that large, moist cloud baseat the bottom of the parent storm, it sucks it in and turns it into a rotating wall of cloud, forming a link between the storm that created it and the Earth.

The second that tube ofspinning cloud touches the ground, it becomes a tornado.

Most are small and short-lived,producing winds of 65-110 miles per hour, but others can last for over an hour,producing 200 mile per hour winds.

They are beautiful but terrifying, especially if you or your town is in its path.

In that case, no one,not even tornado chasers like me, enjoy watching thing unfold.

Just like everything, however,tornadoes do come to an end.

When the temperature difference disappearsand conditions grow more stable, or the moisture in the air dries up, the once fierce parent storm losesmomentum and draws its tornado back inside.

Even so, meteorologists and storm chaserslike me will remain on the lookout, watching, always watching to seeif the storm releases its long rope again.

Source: Youtube