Do you know the weather signs of a tornado? Do you know which ones are old wives’ tales? Could your character be hit with more than one tornado in the same storm? What the heck is a fire tornado? Find out on this episode!
Today is the start of a three-part tornado series: Tornados Weather 101, Inside a Tornado (Survival), and Tornado Triage and First Aid.
Tornados are common in many countries around the world, but the United States has the most, with roughly 1,200 per year. That is about 90% of the world’s tornados. Other places with them are South America, Africa, Australia, Asia, and Europe. The two most common countries other than America to have tornados are Bangladesh and Argentina.
I personally live in what is known as Tornado Alley. That is the section of America that has the most tornados and the most violent tornados. Spring is known as the tornado season. Fall is sometimes called our second tornado season, but it also happens in summer and sometimes winter.
This happens because of the way tornados form during unstable weather. Simply put, when a warm or cold front meets with the opposite temperature, warm air will rise, and cold air will fall. Sometimes, the air mass moves into the area with a wedge shape, meaning it is very likely the air is exchanged diagonally instead of straight up and down. This air exchange can potentially lead to a violent twisting wind that exchanges these temperatures. We call that a tornado or, less often, a twister. Unless you are my dad, and then you call it a tornader.
Now, for those wondering why getting warmer or cooler makes a difference since the whole world has weather, I’m not talking about small, slow changes but sudden changes in temperature. As someone who lives in Tornado Alley, I can tell you firsthand that our temperatures can change by 10 to 20 degrees in only a few minutes. It doesn’t happen every time, but a temperature change in a short time frame is when tornados are likely to form.
Tornados can form any time of day or night and in any season. However, they are most common in the spring and between the hours of 4:00 PM and 9:00 PM. The most likely temperatures they form in are 65 degrees Fahrenheit (18 degrees Celsius) to 75 degrees Fahrenheit (24 degrees Celsius), but they have been recorded forming as low as -40 degrees Fahrenheit (-40 degrees Celsius) and as high as 115 degrees Fahrenheit (46-degree Celsius).
Tornados do come with thunderstorms, but approximately 80% of the time, they form out of a supercell. These are massive, long-lived thunderstorms. They have a distant look to them because of the updraft. Most people call it an anvil shape. Many call it a cloud wall. Others say it looks like a volcano erupted and filled the skyline. No matter how you heard it described, the bottom of the storm looks further away and the top closer, making it appear like a diagonal-shaped cloud. Most of the time, these are so large they take up the entire skyline.
A supercell system can be hundreds of miles long but typically only 10 to 20 miles wide. That can travel at 100 MPH (160 KMH) or can be too slow for my comfort at only 12 MPH (20 KPH) but typically travel around 40 to 50 MPH (65 to 80 KPH). Supercells can also last, even traveling at those speeds, for hours, typically 2 to 4 hours. However, there can be a lot of rain or even thunderstorms (of less intensity) behind the supercell.
Tornados can form and stay above the ground for several minutes before touching down, so to speak. Once on the ground, they can grow slowly or quickly. An example is the Joplin, Missouri, 2011 tornado, which went from nothing to a mile-wide tornado in approximately 20 seconds. Remember that it is rare.
Until 1948, in America, the word tornado was banned from broadcast to guard against mass panic, as they could not predict where they might hit. In 1950, the Weather Bureau and Air Force bases in Kansas, Nebraska, and Oklahoma came together to work on what was called the Tornado Project. This was to forecast tornados. Later, we upgraded to what is called the Doppler Radar. It was first used in May of 1985, and while it has improved, it is still the version of radar we use today. The warnings come across what is called The Emergency Broadcasting System. It will break through all radio and local TV stations to give out warnings. Local stations will have a radar in the corner of the screen to let the viewer watch where things are. There is even a form of reverse 911 for warnings if a person signs up for them.
Yes, most of those who grew up here in Tornado Alley can read a radar, but not as well as the weathermen or women. They are awesome, and we are grateful for them! One of the main reasons is that while Doppler Radars are good at predicting tornados on the ground, they are not good at predicting them beforehand. That’s where the weather people come in. They are good at interpreting where it might be likely and can warn people in that area that there is a high chance of a tornado, while it is not guaranteed.
You also need to know the difference between watches and warnings. A watch means that there is a chance of whatever it is about: tornados, severe thunderstorms, floods, etc. Warnings mean a tornado on the ground or whatever the warning is about.
For those of you writing times without radar storm chasers, or, for characters going through a tornado, there are other signs that a tornado is likely to happen, but it doesn’t mean there will be a tornado. These include:
* Wall clouds are one of the first signs and can be seen in the distance, giving time for your character to prepare for the chance of a tornado.
* Large hail can be associated with a tornado.
* Many people report a quiet just before the tornado hits. I can tell you from having lived through a tornado, it does not happen every time.
* A loud roaring that sounds similar to a freight train or a whistling sound can indicate an incoming tornado.
* Visibly seeing the funnel of a tornado. Clearly!
* Seeing debris means a tornado is close enough; your character needs to take cover, but it doesn’t mean the tornado is coming toward them. Tornados can throw debris several miles, depending on how strong the winds inside the tornado are.
But the most well-known sign of a tornado is a green sky. Simply put, this happens when the light in the atmosphere illuminates the water or ice droplets in the cloud, usually in a wall cloud. It is important to note a green sky only means a strong likelihood and is not a guarantee of a tornado.
Also, contrary to what many people have heard, hail does not mean a tornado is definitely coming. Nor does rain mean tornados are not coming. These are old wives’ tales. Another well-known wives’ tale is to hide in the northeast corner of a building. Most tornados track from southwest to northwest. However, they have been known to change directions mid-path and have even been known to backtrack.
Now that we know the signs, let’s go over the seven tornados.
1) Rope tornados
These are some of the smallest tornados, at least when it comes to their circumference. They can be quite long in their length and look like ropes, hence the name. Most tornados look like this when they form and when they end. However, they must be this type for their whole life cycle to be a rope tornado.
While these seem like they should be relatively weak, they can actually be quite intense as they tighten or narrow. Think of it like how an ice skater spins intensely as they bring their limbs close to their body.
2) Cone tornados
These tornados are often the ones that come to mind when people think of tornados. As with rope tornados, they get their name from their cone or funnel shape, being more narrow at the bottom.
3) Wedge tornados
These types look wider than they are tall. They are at least a half-mile wide but could be wider. They can leave a large trail of destruction. Some of the largest and most distractive tornados in history were wedge tornados.
4) multi-vortex tornados
This is when a tornado has one or more other tornadoes spinning around the main tornado. As far as I can tell, this kind only comes out of supercells. They are typically rope tornados that do extra damage. You can’t always tell that there are additional tornados, as they could be rain-wrapped. Radars and looking at the aftermath are sometimes the only way to tell if it was a multi-vortex, but this is not always true.
6) Satelite tornados
These are very similar to multi-vortex tornados, as they have multiple tornados. However, with satellite tornados, there are two or more tornados that are completely independent of each other. Typically, the first is strong, and the second one is weaker. The name comes from the fact that they rotate around each other.
7) Water or land spouts
Water spouts and land spouts are classified as tornados; however, they can develop when there is no thunderstorm and are only recorded as a tornado if they touch land.
Water spouts develop over water the same way tornados do. They can also develop in what is called a fair-weather waterspout. According to AccuWeather (and I quote): “These ‘fair-weather waterspouts’ are more common than their counterpart and can develop under clouds such as those associated with lake-effect rain and snow showers around the Great Lakes. “They are smaller and weaker than the most intense Great Plains tornadoes but still can be quite dangerous,” the SPC said. Despite being weaker than most tornadoes, they can still be strong enough to overturn boats and create rough seas.”
Land spouts are a mix between a dust devil and a tornado. They form the same way water spouts do but are weak. The strongest land spouts are classified as EF – 0 tornados. This is the weakest tornado type that we will be covering shortly. They only last for a few minutes.
8) Rain-wrapped tornados
As the name suggests, rain-wrapped tornados are wrapped in rain. Normally, tornados form in another part of the storm, but when the atmosphere has an extremely high moisture content, they can form inside the rain. This makes them very difficult, if not impossible, to see. That leaves little to no time for your character to find shelter.
That said, modern radars can pick them up, which is why warnings are so important. A good example of this is the 2011 Joplin, Missouri, tornado I already mentioned. The tornado could not be seen; however, the radar was able to pick it up, giving them as much time as possible to be able to sound the tornado sirens and the local TV stations and radio stations, along with all weather stations, to send out warnings to take cover now.
9) Fire tornados
Fire tornados are mostly made of fire and ash. They are most common inside of wildfires. Why? Because the super-heated air wants to travel up, and the air above it is cooler. The exchange in a wildfire can make a fire tornado. This type is fairly rare.
The next thing to go over is the tornado scale or classification. The first scale was called the F scale or the Fujita scale. It was invented in 1971. It had six categories. These are the following:
* F0 – These had a wind speed of less than 73 MPH (less than 117 KPH). This did light damage: some damage to chimneys, branches broken off trees, shallow-rooted trees pushed over, and sign boards damaged.
* F1 – Has wind speeds of 73-112 MPH (117 – 180 KPH). This does moderate damage: peels surface off roofs, mobile homes pushed off foundations or overturned, moving autos blown off roads.
* F2 – These have wind speeds of 113-157 MPH (181 – 252 KPH) This does considerable damage: roofs torn off frame houses, mobile homes demolished, boxcars overturned, large trees snapped or uprooted, light-object missiles generated, cars lifted off the ground.
* F3 – Has wind speeds of 158 – 206 MPH (242-331 KPH). This does severe damage: roofs and some walls torn off well-constructed houses, trains overturned, most trees in the forest uprooted, heavy cars lifted off the ground and thrown.
* F4 – These have wind speeds of 207 – 260 (333-418 KPH). This does devastating damage: well-constructed houses leveled, structures with weak foundations blown away some distance, cars thrown and large missiles generated.
* F5 – Has wind speeds of 261-318 (402-511 KPH). This does incredible damage: strong frame houses leveled off foundations and swept away, automobile-sized missiles fly through the air in excess of 100 meters (109 yds), trees debarked, incredible phenomena will occur.
In 2007, the F scale was replaced with the enhanced F scale. This scale estimates the wind speeds after the tornado happens by surveying the damage and having three-second gust estimates. Tornados can have damage from minor tree limb damage to total destruction of homes and businesses all the way to the foundations of the building. If writing historical or a place without homes, this could take every single tree down to the stump. The rating and category system feels convoluted to me, so I will give you the wind speeds, and if you want to learn more, I will leave you a link in the show notes.
The EF scale wind speeds are as follows:
* EF 0 – 65-85 MPH (104-136 KPH)
* EF 1 – 86-110 MPH (138-177 KPH)
* EF 2 – 111-135 MPH (178-217 KPH)
* EF 3 – 136-165 MPH (218-265 KPH)
* EF 4 – 166-200 MPH (267-321 KPH)
* EF 5 – Over 200 MPH (Over 321 KPH)
Sometimes, straight-line winds are mistaken for tornados. These are a type of thunderstorm winds that can reach speeds over 100 MPH. The highest recorded wind speed was 253. They can have loud roaring associated with them. These are often associated with a line of storms that bow or have a curved shape on the radar. These are very common in tornado alley and actually happen more than tornados do.
Fun fact: Dust devils look like tornados but are not real tornados. They are considered brief whirlwinds.
What could possibly go wrong:
Likely to go wrong: Your character survives a tornado only to be hit with hail after the tornado ends.
Likely to go wrong: After your character survives a tornado, they are hit with heavy rain, potentially causing flooding.
Possible to go wrong: Your character grew up with tornado sirens and warnings. They could easily become complacent and not take the warnings seriously.
Possible to go wrong: Yourcharacter believes there is no tornado because they can’t see it, and they do not take cover. They are then hit with a rain-wrapped tornado. This could be deadly.
Unlikely to go wrong: Like a scene from Twisters, something weird is thrown past your character. This could be a trampoline, a canoe, or even a school bus.
Unlikely to go wrong: Your character has no idea what the green sky could mean, and they do not know to take shelter.
Improbable but technically still in the realm of possibilities: Your character encounters a satellite tornado and is hit by both tornados.
Improbable but technically still in the realm of possibilities: Your character hides in the northeast corner of a building, and the tornado backtracks and hits the building a second time. Your character might be injured or killed when they believed they would be safe there.
Helpful Links To Learn More:
Types of Tornados: