Everything You Need to Know About Tornadoes

· Reading Time: 12 minutes

No matter where you live in the United States, you’re not immune from tornadoes. According to the National Oceanic and Atmospheric Administration (NOAA), every single state in the U.S. has experienced a tornado. That means no matter where you live, learning about and preparing for tornadoes is important.

In order to prepare most effectively, learn about these twisting phenomena. Once you know more about tornadoes, you can use your knowledge to prepare as best as you can.

 

What is a Tornado?

Tornado 01Let’s start off with the basics. Chances are you’ve at least seen a picture of a tornado, which means you know what one looks like. But what exactly is a tornado?

According to The National Severe Storms Laboratory, a tornado “is a narrow, violently rotating column of air that extends from the base of a thunderstorm to the ground.” That’s a pretty good description. Tornadoes, however, are naturally invisible, since they’re made up of air. The reason we are able to see a tornado is due to the fact that the vortex is made up of water droplets, dust, and debris.

Tornadoes form when warm, moist air (usually from the Gulf of Mexico) collides with cool, dry air (from the North, usually from Canada). This collision of air pressures destabilizes the atmosphere, causing changes in wind direction. When this change occurs, wind speed also increases, which causes the spinning effect we attribute to tornadoes. As mentioned above, the reason we can see this spinning air is because of all the extras the vortex picks up with it.

 

Tornadoes on Radar

The United States is the most tornado prone country in the world. NOAA reports an average of over 1,000 tornadoes in the U.S. every year. The next country in line with the most yearly tornadoes is Canada with roughly 100 twisters annually. So congratulations, America, on having the most tornadoes.

Tornado Alley Infographic - via LiveScience
Tornado Alley via LIveScience (click to enlarge)

Although the United States wins when it comes to tornado count (if you can call that “winning”), most of the states aren’t tornado prone. There are a few states, however, that make up what is known as Tornado Alley. These states are in the Midwest and start in Texas, then up through Oklahoma, Kansas, Nebraska, and South Dakota. Don’t forget about Colorado and New Mexico which also see their fair share of twisters. Tornado Alley can also spill into Iowa, Missouri, Illinois, Indiana, and parts of Ohio.

Tornadoes struggle to form in the winter months, but they can start coming as early as March. Spring is the official start of tornado season. Tornadoes will begin to form more frequently in the Southern Plains, and from there work northward. Tornado season begins to wind down in the Northern states and the upper Midwest around June or July.

But, just because there’s a season set for these twisters doesn’t mean they follow the rules exactly. Sure, spring sees the most tornadoes (all the way up through July), but they can still form before or after their expected dates. Likewise – as mentioned above – they can form in any state. For example, a tornado struck Salt Lake City, Utah back in 1999. To throw us off even more, the tornado occurred in August. If we’re following the rules of tornado season and where tornadoes generally form, both the location and the month should dictate that a tornado just shouldn’t have shown up in Salt Lake City in August. But, as is typical with natural disasters – especially tornadoes – we just can’t predict when or where they’ll spring up.

 

Tornado Damage

From thin to thick, tornadoes vary greatly in size and form. That doesn’t mean, however, that size determines strength. Some small tornadoes can be at the strongest measurement, whereas a wide tornado can be fairly weak. But no matter what size a tornado is, you should take cover anyway. Even a weak tornado can cause injury or death.

 

Tornado Ratings

16 June 1992 Chandler Tornado EF 5
Chandler, MN Tornado (EF 5), June 16, 1992

Tornadoes are ranked based on the Enhanced Fujita scale (EF), which replaced the original F-scale in 2007. While similar, there are a few differences in how it’s measured (the image to the side shows how the EF scale gets its rankings). Once wind gusts reach 65 miles per hour, the lowest level of the EF scale is reached (EF0). After that, the rankings rise as the winds increase. An EF5 constitutes wind speeds over 200 mph.

While EF5’s are obviously devastating, even the weakest EF0 can bring about lots of damage and injury. Just because a tornado isn’t an all-out howler doesn’t mean you aren’t at risk. After all, 65 mph is quite fast; it may just look slow when compared to the other speeds on the EF scale.

 

Before a Tornado

In order to be as safe as possible during a tornado, it is important to prepare in advance. Knowing exactly when and where a tornado will strike is quite nearly impossible. However, there are some things you can do to be better prepared.

 

Be Prepared

How does one prepare for a tornado? First off, make sure you have enough food, water, and other essential gear for at least 72 hours. The ideal place to keep this gear is in your basement or storm shelter, as the winds are less apt to reach down there and blow everything away.

Empty Shelves - TornadoFollowing a tornado, power may be out for days, leaving you without a way to refrigerate your food, have light, air conditioning, and other comforts of life. Having food that won’t go bad if not refrigerated (freeze-dried food being a great option) gives you greater control over your diet. It is common for store shelves to be stripped bare before and immediately following disasters.

If your power is out, having an alternate source of power can make a huge difference until your home’s power gets up and running. These smaller power sources can charge your cell phones, and depending on the size of the power supply, can charge laptops and even power your television. Having a bit of extra power on hand can make a huge difference following a disaster, especially once the sun sets and darkness falls.

Shelter is something else that’s important to procure before a disaster. If your home becomes damaged so much that you can’t stay the night for fear of structural damage, having a tent or other form of shelter will keep you covered.

 

Know the Signs

You may not always be around a radio or television for tornado alerts, so knowing the visual signs of an imminent tornado is important in making it safely to a shelter in time. You’ll know there’s a tornado coming if you see the funnel cloud – that part is obvious – but there are some other, perhaps lesser known signs to look out for.

green sky tornadoA dark, sometimes green sky can give good indication that a tornado is about to form. There is a lot of hail in thunderstorms associated with tornadoes, so as this hail begins to be whipped around, the light of the sun refracts off the hail, giving the sky a green tint. The sky won’t always be green before a tornado, however, so don’t be fooled if the sky just appears very, very dark.

A loud roar – similar to a freight train – is another way a tornado may be heralded in. This is especially useful if you don’t live near a railroad, as the sound might be a bit out of place. The high velocity of the winds produce the howling, as well as all the debris the tornado is hurling around and smashing into.

Another sign of a tornado is a strange calm after a thunderstorm. Tornadoes are not uncommon after a large storm, so don’t be surprised if you see a clear, calm sky followed by a tornado!

 

Do Drills

If you want to get better at a sport, you’ll most likely be doing drill after drill in order to get your skills up to – and way above – par. Likewise, if you want to be as safe and prepared as possible for a tornado, you’ll want to do tornado drills until you and your family know what to do without having to hardly think about it.

Tornado drills will be pretty similar for each family, although there will be differences in your designated safe room in your home and other things depending on your location. Tornado drills should involve acting out what you should do during a tornado (see section During a Tornado below).

 

Watch vs. Warning

tornado watch

Knowing the difference between a tornado watch and a tornado warning can help you better prepare. A tornado watch suggests that tornadoes are possible. This warning can cover entire cities, counties, and even multiple states. When a tornado watch occurs, that is the time to check and gather your supplies, review your emergency plan, and identify and locate your nearest safe room. A tornado watch may pass without incident, but it could very quickly turn into a more dangerous situation.

A tornado warning means that there is a visual on a tornado, or has been indicated by weather radar. Once a tornado warning arrives, head directly to your safe room. Avoid window and open areas. Tornado warnings cover a much smaller area than tornado watches – perhaps a single city or county – but act as a warning to those in the area to take action immediately.

 

During a Tornado

The first step to take when you hear the tornado sirens going off (or receive the warning in some other way) is to take shelter. Where you find cover depends largely on where you are and what is available.

 

Minimal/Inadequate Protection

During a Tornado - Outside - via Ohio Weather Safety
Outdoor Tornado Safety via Ohio Weather Safety (click to enlarge)

Some locations just don’t provide adequate protection. Being outside is, of course, one of these places. Other shelters that provide inadequate cover are manufactured (i.e. mobile) homes and offices, malls, gymnasiums, and vehicles. The problem with manufactured buildings is they blow away far too easily. Malls, gymnasiums, and other open-plan buildings are too open.

If you do find yourself outside when a tornado starts to form and there is no available shelter to run to, lay flat in a ditch or other low-lying area. Use your arms or another object to protect your head from flying debris. Avoid areas with trees, and do not take cover underneath an overpass. Doing so can put you at greater risk from the winds and debris.

 

Moderate Protection

While not always 100% effective, sturdy buildings – like modern houses – can provide adequate decent protection from tornadoes. Still, while inside a sturdy building, you’ll still want to exercise caution. Stay away from window, which can shatter and start flying through the air. In fact, it’s best to find yourself a central room on the lowest level of the building. A room such as that will provide you with the most protection.

Even if you feel safe inside a sturdy building, still take cover. Use what you can find – blankets, sleeping bags, pillows, etc. – to cover up so if the howling winds do break through, your body will still be at least somewhat protected from flying objects.

 

Best Protection

If you live in an area that is constantly at threat from tornadoes, perhaps it’s time to look into a safe room or storm shelter. These safe havens will withstand nearly all strengths of tornadoes and greatly increase your chances for safely weathering the storm. FEMA has a guide on building a personal safe room, so be sure to check it out.

 

Outdoor Safety

Being outside during a tornado is one of the least safe places you can be. There is little to no protection, and between the buffeting winds and the flying debris, things could get unpleasant fast. One of the best things you can do during a tornado, no matter where you are, is to stay low to the ground, or even below it if possible. If available, lay flat in a ditch. This will help protect you from debris and other flying objects. Do not hide underneath an overpass. This could potentially channel the already high wind speeds, making them even faster. Besides stronger winds, there is usually nothing to hold on to, and dirt, debris, and other projectiles can be channeled through, making you a susceptible target.

Should you be driving when a tornado comes, do not try and outrun it. Tornadoes can be dangerously fast, and can shift direction without warning. Pull over and park your car. If you see a noticeably lower area than the roadway you’re on, quickly make your way there and lie flat, covering your head with your hands. Otherwise, remain in your car with your seat belt on.

 

The following video helps explain what you should do during a tornado.

 

 

After a Tornado

Once the winds have died down and the threat has passed, you can start surveying the damage and checking for injuries. But remember, just because the tornado has passed doesn’t mean the danger is over. A study done after an Illinois tornado showed that half of the injuries caused by that tornado came during rescues, cleanup, and other activities following the tornado. So while it is important to take care of yourself, others, and your home once the tornado leaves, it is important to do so with caution.

 

Check for Injuries

Tornadoes can be deadly. Caring for the injured should be the first thing you do after a tornado. Clean open wounds and cuts with soap and clean water. If you or someone near you is bleeding, apply pressure directly on the wound to help it stop. If you find somebody that is seriously injured, do not attempt to move them. Doing so could only injure them more. For more information on taking care of the injured, check out the CDCs post-tornado page.

 

Damaged Structures

Tornado damage

Buildings can be badly damaged because of tornadoes, but you may not be able to see some of it. This includes some structural damage which can leave your home weakened. This is a potential hazard, so when the tornado passes and you start inspecting your home, be extra cautious.

If you smell natural gas, or suspect there might be substantial damage to your home, you should turn off your gas valve. This will keep the gas from coming through into your home so you don’t have to worry about breathing it in. Likewise, if there is too much gas floating around inside your home, that has the potential for an explosion should some sort of open flame come too close. This is why using a flashlight is a better option than a candle or torch when checking out the damages.

Similarly, shut off the main circuit breaker if you see any sparks, frayed wires, or other electrical damage. Sparks could jump up and catch your home on fire.

 

Cleaning Up Safely

Because there will probably be a lot of dangerous debris, be sure to wear the proper attire when cleaning up. Glass and other sharp objects can be anywhere, so wear sturdy boots, cloves, and long sleeves and pants. Pay attention to your surroundings, and don’t go into any building that has received extensive damage and may not be structurally sound. Remember, many injuries come after the tornado has passed.

 

Disaster_Blog_Banner Tornado

 

One Response

  • I am a tornado survivor who lived west of Atlanta in an El Niño year (November, 1992). The southeastern states are “death alley” during an El Niño due to the cold from Canada dropping further south. November and February of 1992/1993 had deadly outbreaks due to the sudden weather change of warm and cold. Be aware that I thought tornadoes were a summer e ent for the Midwest, but it is not! The day our home was taken by an EF4 was foggy drizzle, 62 F with humidity at or above that (a key element). Sirens were not installed in that part of Cobb County at that time. Take watches and warnings seriously and have a “safe” place.

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