TORNADO FACTS
-A tornado is a violently rotating column of air extending from a thunderstorm base to the ground with concentrated, whirling debris or a dust cloud. (A funnel cloud rotates, but has no contact with the ground, no debris and is not doing any damage).
-Tornadoes usually are preceded by very heavy rain and, possibly, hail. If hail falls from a thunderstorm, it is an indication that the storm has large amounts of energy and may be severe. In general, the larger the hailstones, the more potential for damaging thunderstorm winds and/or tornadoes.
-The most violent tornadoes are capable of tremendous destruction, with wind speeds of 250 m.p.h. or more.
-An average tornado damage path is one-to-two miles long, but can be in excess of one mile wide and 50 miles long.
-Widths vary considerably during a single tornado, from less than ten yards to more than a mile, but typically are about 50 yards wide.
-The average tornado moves from southwest to northeast, though tornadoes have been known to move in any direction.
-The average forward speed of a tornado is 30 m.p.h. but may vary from nearly stationary to 70 m.p.h.
-Tornadoes are most likely to occur between 3 p.m. and 7 p.m. but have been known to occur at all hours of the day or night.
-The National Weather Service uses Doppler weather radar to sense the air movement within thunderstorms. Early detection of increasing rotation aloft within a thunderstorm can allow time for lifesaving warnings before the tornado forms.
TORANDO MYTHS
1. Overpasses are ideal places to seek shelter from tornadoes if you are caught outside.
Busted! Highway overpasses are deadly. When a tornado approaches an overpass the wind speed is actually increases as the wind is “compressed” to go through the overpass. This increase in wind speed can carry debris that is picked up by the tornado under the overpass and greatly injure or kill any persons taking shelter there. This also creates a problem during the aftermath of a tornado because the tornado is likely to damage any cars that the motorist had abandoned and therefore cutting off highway access of emergency vehicles that may need to get through the overpass.
2. Hills and Rivers will protect areas from tornadoes by deflecting them.
Busted! Tornadoes can happen at any place and any time. Tornadoes have been observed crossing the Appalachian Mountains and more than 30 significant tornadoes (a lot more 'not so' significant tornadoes) have crossed the Mississippi River. When a tornado cross a hill or a mountain the vorticity tube is “stretched” and in effect the tornado will spin faster. This is much like if you were spinning a rubber band between your hands and you stretched the rubber band – it spins faster, it is simply a matter of physics. As per rivers protecting towns and areas, this is completely false. Emporia, KS is surrounded by three rivers and it took a devastating tornado hit in 1969 by a tornado that crossed at least one river to get into the city. Storm chasers have also reported tornadoes crossing rivers and even large lakes. In fact, a Water Spout is a type of tornado that forms over a body of water!
3. Tornadoes will change direction and even reverse their direction.
Busted! A tornado is a spinning column of air in contact from the cloud base to the ground. The clouds that it is connected to are storm clouds (most commonly rotating thunderstorms called “Supercells”). These storms are being steered by upper-level winds and generally move in a west to east or southwest to northeast direction and therefore since the tornado is connected to the clouds they would also move in this same direction. While a tornado can “wobble” a bit beneath the storm, they do not reverse their direction.
4. Tornadoes never strike the same place twice.
Busted! The first successful tornado forecast was made at Tinker Air Force Base in Oklahoma City on March 25th, 1968 when a tornado crossed the air force base. Oddly enough a tornado had taken nearly the exact same path across the air force base on March 20, 1968 (just 5 days apart!). In fact, Oklahoma City has been hit by tornadoes numerous times in recent years alone. On May 3rd, 1999 an F5 tornado devastated the southern portion of Oklahoma City.
5. Storm chasing is exactly as portrayed in the movie, “Twister.”
Busted! Twister is a Hollywood creation. And the truth of Twister is about as far from actual storm chasing as Hollywood is from Tornado Alley! While the main plot of twister (“Dorothy”) was based on a real-life experiment called “TOTO,” just about every other portion of the movie pertaining to tornadoes displays a false representation of real-life storm chasing, storm chasers and actual tornadoes. In the movie Dorothy was a success, while in real-life TOTO was a failure. Not every chase ends with a Hollywood conclusion!
6. Storm chasers have been able to launch probes into tornadoes.
Partly true. A few storm chasers have been successful as putting a probe on the ground that took a close, or direct hit from a tornado. These probes have not been designed (as of the time of this writing) to “fly” into the tornado. In fact, they are designed to stay on the ground and record pressure and other sensitive measurements from a near-tornado pass (or direct hit). Some other probes have been designed for just recording images. The most notable of these chasers is Tim Samarus, who is an electrical engineer by trade and an expert storm chaser.
7. The pressure changes from a tornado will blow out the windows of a home.
Busted! Research has shown that the drop in pressure from a tornado has no effect on glass windows in a home. This is an old myth that got started in the late 1800s when a U.S. Army Signal Corps officer named J.P. Finely traveled to the central plains to record eye witness testimonials about a series of tornado events that had occurred. In recent years scientific research has proved that the destruction of glass windows is a result of flying debris impacting the window. Further, after the window is broken shads of glass are also thrown through the air and add to the debris field. This is why it is important to stay away from windows during a tornado. Glass flies into the house, not outside!
8. If a tornado is approaching you should open your windows.
Busted! See item number 7 above. If a tornado is approaching your house it is NOT going to make a difference whether your windows are open or closed. A direct impact will likely damage your house and windows no matter what position they are in. By opening the windows you are wasting valuable time that you will need to take shelter. The best thing to do once a tornado is spotted, heard or observed is to take immediate shelter. The best place to take shelter is in the center-most part of your home, away from windows and exterior walls and to cover your head. Bathtubs that are not located near glass windows make exceptionally good tornado shelters if nothing else is available. You can also you a twin size mattress (if readily available) to protect yourself from things such as a roof caving in.
9. Mobile homes are more likely to be hit than other types of homes.
Busted! Mobile homes are not more likely to be hit than any other type of structures. However a mobile home is not built to withstand the strong winds that are associated with weak tornadoes, while most other types of structures can withstand (but will still be damaged) by weaker tornadoes. In fact, some mobile homes have been completely destroyed by tornadoes without even taking a direct hit, while some homes have only experienced minor roof damage from weak tornadoes (F0, F1) after sustaining a direct hit. If you are caught inside a mobile home while a tornado is approaching, get out! It doesn’t matter if your mobile home is “tied down” and “secured” or not. Grab your pets as quickly as possible and find shelter outside of the mobile home, even if you have to let your pets go once you are outside, chances are they will be much better off “on their own outside” than they are inside of a mobile home. As for human life, if there are not any storm cellars or sturdy structures nearby – find the lowest area possible, such as a ditch and stay low. The idea is to keep the violent wind speeds above you by lying in a lower area. It is best to have a plan in-place for these situations and to practice that plan at least once a year. You might look dumb running out of your mobile home on a sunny day and jumping into a nearby ditch, but it will help you think clearly about the situation when you are under pressure in a situation like this, and it may save your life!
10. The southwest corner of a house or basement is the safest place to go during a tornado.
Busted! Again from the eyewitness accounts taken by J.P. Finely in the late 1880s, he concluded that some structures were more intact on the southwest side and therefore that was the safest place to take shelter from a tornado. However, research and past tornado events have shown time and time again that this is not the case. You should avoid any exterior walls, especially if they are made out of a natural stone (such as a brick fireplace) as they might fall on top of your after being hit by a tornado. The current best advice is to move to an interior room on the lowest floor of the building, away from glass windows and cover your head. If you don’t have a basement or storm cellar, you may consider purchasing a “safe room,” which can double as a closet when you’re not using it to stay alive during a tornado.
11. Storm chasing looks like fun and from the movies I have seen safe enough to try.
Busted! Tornadoes have the most violent wind speeds on Earth and that is not anything for an inexperienced person to try and chase down. Aside from the tornado itself there are many other dangers to be considered such as hail that can be as big as softballs, debris flying through the air, flooded roads, etc… It is understood that some people are completely fascinated by the thought of seeing a tornado and if this describes you, then we suggest you participate in a guided storm chasing tour that is led by experienced storm chasers who have the knowledge and technology to not only find tornadoes, but to also stay alive while viewing them. If you need a good source, this website is sponsored by the largest company that offers storm chasing tours and they are highly recommended, you can find their website at: http://www.violentskies.com
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