Written By PinPoint Weather Intern Andrew Cook

What is a Tornado?

By definition, tornadoes are rapidly rotating columns of air that stretch from the base of a thunderstorm to the ground--

More simply put, this is a tornado:

Tornadoes can come in all shapes and sizes and the following are the most  common types. There is the rope-like tornado, which is familiar to all you Wizard of Oz fans (Above), a stovepipe tornado ( below left), and a wedge tornado(below right).

How Dangerous are Tornadoes?

Tornadoes are often cited as the most dangerous weather systems on the planet, and can have winds topping out above 300 mph! Tornadoes are rated on something called the enhanced Fujita Scale, which correlates damage from tornadoes to their approximate wind speeds. Below is a table showing the ratings of tornadoes as well as the damage expected for a modern single family home.

Where do tornadoes occur?

Tornadoes can occur nearly anywhere that the conditions are right for a powerful storm to begin rotating. These conditions are much more common in an area known as tornado alley, where conditions that a favorable for the formation of tornadoes occur more readily throughout the year than anywhere else on Earth. Tornado Alley is most active in the spring months from March to June, but a tornado may form anytime throughout the year if a storm is strong enough. Texas is included in Tornado alley and here storms that produce tornadoes are much more prevalent than elsewhere.

Tornado Watch v. Tornado Warning

A Tornado Watch is issued when the conditions for the formation of a tornado producing storm are likely. When a tornado watch is issued it only means that people in the warned area should be aware that the atmosphere is unstable and can produce powerful storms that may also produce tornadoes. If a watch is issued it would be best to mentally run down your tornado checklist and coordinate where you would seek shelter if worst comes to worst.

A Tornado Warning means that meteorologists with the National Weather Service have detected a storm that is capable of producing or already has produced a tornado. When a tornado warning is issued this means that the warned area is under extreme danger of a tornado strike and everyone in the area should seek shelter immediately.

What Should I do to Prepare?

Decide ahead of time at your home, work, and school where the appropriate place to seek shelter in the event of a tornado emergency would be. The best place to seek shelter during a tornado is in an interior room on the first floor, away from exterior walls and windows, while covering yourself in blankets or a mattress. If you live in a mobile home it is important to find a close by sturdy shelter to go to ahead of time, such as a friends house, church, or public building. As always an underground storm cellar is the best options for surviving a tornado. NEVER try to get in your car and outrun a tornado, because cars are very light and even the weakest tornadoes can toss a car very easily. An emergency kit with food, water, a weather radio, batteries, and any medications should be prepared ahead of time and placed in your designated storm shelter.

Tornado Myths

1. Tornadoes cause a massive pressure difference to occur between the inside of your home and the outside, so to reduce damage you should open windows and doors to reduce the pressure.

• FALSE: The pressure differences are nothing compared to the massive winds associated with the vortex and by opening windows and doors you allow winds into the home compromising the integrity of the structure and wasting valuable time to seek shelter

       2.   If caught on the road during a tornado you should pull over and take shelter under a bridge              overpass.

• FALSE: Though popularized by a video in the 90's, bridge overpasses are terrible places to be during a storm. The bridge acts like a funnel and concentrates wind into the crevice that you are taking shelter in, doubling the wind speeds and your danger of being struck by debris.

       3.   Tornadoes do not strike urban area.

• FALSE: Urban areas take up much less space on the earth than rural areas so it may seem that tornadoes only strike rural areas, but urban areas are just as likely as any other to receive a blow. An example of this includes the March 28, 2000 tornado that struck downtown Fort Worth.

Below is a short video by National Geographic that quickly explains tornadoes and tornado safety.