Common Tornado Warning Signs

warning sign

If you live in a part of the country that’s prone to tornados, then you probably already know that tornado season is between March and June. Unfortunately, you may not know that a tornado can happen at any time, based on where you live. Because of this, it’s important that you know what the tornado warning signs are, so you can get yourself and your loved ones to safety and stay out of harm’s way.

The Raw Power of a Tornado

Tornados are fast-spinning platoons of air that are in association with the surface of the earth and cumulonimbus clouds. While rare, a tornado can even be in contact with the cumulus cloud base. Most of the time, a windstorm is referred to as a twister, whirlwind, or cyclone. However, the term cyclone is often used in meteorology to define weather systems that possess a low-pressure area that runs along the center.

If you looked directly at the surface of the earth, you would most likely see wind that’s blowing counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. A tornado comes in a variety of shapes and sizes, many of which will come with a wind speed of up to or more than 180 miles per hour.

Whirlwind Countries

Tornados commonly occur the most often in Northern America, which is referred to as tornado alley. They can also occur in:

  • Eastern India
  • New Zealand
  • Bangladesh
  • Southeastern America
  • Western Australia
  • Southeastern Australia
  • Southern Africa
  • Northwestern Europe
  • Southeast Europe

A meteorologist is experienced enough to detect the warning signs of an approaching tornado with the help of a pulse doppler radar. This radar monitors velocity patterns and reflectivity data, including hook echoes and debris balls. Meteorologists will also use storm spotters to search for signs in order to alert people of an approaching tornado.

Whirlwind Duration

Typically, a tornado will not last longer than ten minutes, however, they can also have a lifespan of more than one hour, while others may only appear for a matter of seconds.

Why Whirlwinds Occur

An aggressive tornado can originate from supercells, which can be defined as large thunder and lightning storms, complete with revolving wind. Only around one in one thousand storms will evolve into a supercell, with one in five or six supercells evolving into a tornado. Usually, states that are found near the Gulf of Mexico will often experience the tornado season during the first few weeks of spring.

More tornados will pop up in May, despite the fact that April often has the most turbulent weather. A tornado can occur during the night or day, but most of them will develop late in the afternoon once the ground has sufficiently warmed up to generate a storm.

Stages of a Whirlwind

Stormy weather warning sign

A tornado will occur when warm and humid air crashes with cold and dry air. The cold solid air moves through warmer air, which results in a storm. This warm air will advance over the cold, triggering an updraft.

This updraft will begin revolving in cases where the wind differs sharply in terms of speed and the direction. A mesocyclone is the term used to describe a revolving updraft. The speed of a mesocyclone will continue to accelerate as it advances the storm and gathers more warm air. Cold air that’s delivered by strong wind in the air will provide more fuel. The moist air that’s formed by the mesocyclone will form droplets of water that will evolve into a funnel cloud. The funnel will continue to grow until it descends from the cloud base. Once it makes contact with the ground, a tornado will occur.

There are a couple of different types of storms that can trigger a tornado:

  • Supercell
  • Non-supercell

The most dangerous and most common tornados will originate from a supercell.

The mesocyclone will play a big role in the occurrence of a supercell and the resulting tornado.

How Fast Are Whirlwinds?

A tornado will have an average speed of thirty miles per hour, however, they can reach up to seventy miles per hour.

Signs a Tornado is Heading Your Way

Here are the major signs to look for that will indicate that a tornado is heading your way:

Funnel Shaped Clouds

This type of cloud is the best indicator that a tornado is coming. These clouds won’t resemble the regular clouds that you see in the sky on any given day. Instead, they’re very large and you can see it escalating and rotating from a prevailing storm. You can also see the cloud begin to approach the ground.

Debris Clouds

Another common sign that a tornado is coming is a big cloud of debris, which usually hides the funnel cloud. If you notice a cloud of debris, it’s wise to find a safe escape route and head to an emergency shelter.

Loud Blasts

If you hear a very loud blast in the sky, run for cover. These blasts can be very frightening, and it will be accompanied by a strong wind, which will indicate a dangerous and powerful tornado is coming your way. The sound will increase as the tornado moves closer.

The Calm After the Storm

If you notice that there’s an unusual calm in the conditions following a storm, this can also be a sign. It’s totally normal for a sky to clear after a storm, but the weather prior to a tornado will feel very strange and too calm.

Unusual Sky Color

When a tornado is approaching you may also notice that the sky has turned a weird black/green color. This indicates that a major storm is accompanied by strong winds and clouds from where a tornado could occur. Experts are not certain why the sky turns this color, but it’s believed that the red and golden hues from the sunset and the blue that occurs in the air due to scattered light molecules result in the green/black color.

Falling Debris

Another warning sign is falling debris. Most often, a tornado will come with strong winds that can pick up debris and deposit it several miles away.

Preparing for a Whirlwind

disaster checklist

A tornado is considered one of the most destructive weather events and it can leave behind a trail of destruction that’s more than a mile wide. In the US, there are approximately one thousand tornados a year. Most will occur during the spring and summer months, but as I mentioned earlier, they can occur any time of the year.

If you live in a part of the country that experiences tornado season, then you should consider building a safe room that’s concrete reinforced. It should be placed in an underground storm cellar or in the center of your home. A basement is the next best place to seek refuge in the event of a storm, or any room in the home without windows.

Mobile homes and vehicles are the worst places to be during a tornado, so if you find yourself caught in one, immediately leave and seek shelter in a ditch, low spot, or a nearby building.

Always keep the radio set to broadcast important weather alerts when you notice signs of a tornado.

Since tornados can strike without warning at times, it’s important that you keep a supply of items on hand, located in a storm-resistant place in the home.

Food and Water

Nonperishable food and drinking can be in short supply immediately following a tornado. Check on your supplies periodically throughout the year and note the expiration dates to ensure they’re fresh.


Keep several flashlights and lanterns on hand, in addition to extra batteries that you can store in your kit.


Keep your gas can and propane tank full and stored away from your home, in a secure area.


Purchase a battery powered weather radio to stay informed of tornado warnings.

First Aid Kit

Always keep a stock of medical supplies on hand and store it in your safe room, basement, or storm shelter. If you have prescription medications, take them with you to your shelter once there has been a tornado warning.


Keep cash stored in your shelter for use after a tornado has hit and the power is off.

Roofing Materials

Store duct tape, nails, plastic sheeting and tarps in your shelter so you can make repairs to your roof once the tornado has passed.


Keep a stockpile of basic tools in your shelter for use after the storm. This can include utility knives, a handsaw, pliers, screwdrivers, and a hammer.


Generators can provide emergency power when the power is down in your neighborhood. Make sure you know how to set up and use a portable generator and operate it in a safe distance from your home. A generator should never be used in an enclosed space, in a garage, carpet, or near doors or windows. Make sure you follow the included instructions when you use a generator and don’t use it for more devices than the generator can handle.

Important Documents

Keep a copy of your home inventory and your insurance policies in a safe place such as a storm-resistant location or a safe deposit box.

Final Thoughts

tornado in a field

During a tornado watch, if you notice a debris cloud or debris falling from the sky, grab your emergency supplies and immediately find a safe hiding place to stay, such as a basement. When the weather is just right for a tornado, weather service departments will release a tornado watch via radio or news stations and warn people to seek adequate and immediate shelter. Once a tornado appears on a radar, a warning will be issued. If you’ve recently moved to a part of the country that’s prone to tornados, then this list of tornado warning signs may just save your life. Aside from knowing the warning signs of an approaching tornado, make sure you have a plan in place. This will include supplies, a way to communicate with family and friends, and a shelter that you can go to if your home does not have a basement.