Keep your eye on the sky, it’s tornado season. And if that sounds a little preemptive—after all, the most active month for tornadoes is typically May, averaging 294 tornadoes a year in the U.S.—then this blog post is for you. Everything we thought we knew about tornadoes is changing, from the time of year they occur to the areas where they most commonly happen. It’s time to shake off tornado complacency built up by past experience and adapt to the new reality of these windy catastrophes. Everyone should be prepared and know what to do in case of a tornado, and we’re here to help.

What is a tornado?

First, let’s start with the definition of a tornado, also known as a twister. According to National Geographic, “A tornado is a violently rotating column of air that extends from a thunderstorm to the ground.” That violent air column is usually a revolving cylindrical shape referred to as a funnel. And when the twister touches down, it wreaks havoc. This destruction is not limited to leveled buildings, ruined vehicles and uprooted trees—people can also be swept away.

The winds of a tornado may reach speeds of up to 300 miles per hour. And when it comes to severe weather phenomena, these furious funnels are about as dramatic as it gets. A tornado is like a villain in a comic book: often backdropped by a greenish-colored sky, they are unpredictable, they get their power from a thunderstorm, they can throw hail and they have a terrifyingly loud roar. They can’t be overpowered. They can’t be outrun. When a tornado descends, everyone should seek shelter, preferably indoors.

Tornado season

While March to June has historically been defined as tornado season, researchers have found that warm-season tornadoes have declined by 37% and there has been an increase in tornadoes in the cold season. But tornadoes can happen at any time of year, and while most tornadoes occur in the late afternoon and evening, they can also happen at any time of day or night. That level of unpredictability means that there’s no bad time to brush up on twister preparedness, especially since there has also been a spatial shift in where tornadoes typically occur.

Tornado Alley

Tornado alley (sometimes called tornado valley) is not one particular location but rather a loosely defined area in the central United States where tornadoes are most frequent. Specifically, tornado alley has been identified as northern Texas northward through Oklahoma, Kansas and Missouri, as well as parts of Louisiana, Iowa, Nebraska and eastern Colorado. But there’s evidence that suggests tornado alley may be expanding beyond the Midwest, shifting eastward—marking eastern Missouri and Arkansas, western Tennessee and Kentucky, and northern Mississippi and Alabama as the new tornado corridor.

According to Scientific American, the trend of cold-season tornado activity in the expanded tornado alley was on bleak display in 2023, when a “violent twister with wind speeds of 170 miles per hour struck Rolling Fork, Miss., on March 24, killing at least 26 people. A week later, storms in the new tornado alley killed more than 30 people, and another group on April 4 damaged more than 80 structures in Bollinger County, Missouri.”

Check your area to see when the last tornado touched down—you might be surprised to learn twisters are more common than you thought in the area where you live. After all, tornadoes have been reported in all 50 states!

Tornado watch or warning

If you’re not used to hearing tornado watches or warnings in your area, you may not know what to do when the weather alerts start coming in. A tornado watch is often issued to signal that a severe thunderstorm capable of producing a tornado is in the area—be prepared. A tornado warning is issued when a rotation in the clouds or a funnel cloud has been spotted or indicated by radar and there is a serious threat to life and property in the path of the tornado—seek shelter. A tornado emergency is the National Weather Service’s highest alert level. This is issued when a violent tornado has touched down in a watch area and a severe threat to human life and property is confirmed.

These scenarios can escalate very quickly, so when it comes to tornadoes, every second counts. Take shelter immediately when you learn of a tornado warning in your area. Your workplace should have a plan in place for every type of emergency, but it’s important to have a personal plan and go over scenarios for how to react to a tornado, regardless of where you are.

Here are some checklists that can help you stay safe at work, at home, outside or on the road.

What to do at work

1. Follow the instructions of the personnel in charge of the emergency plan.
2. If there isn’t anyone overseeing the emergency, go to the basement or the lowest level of the building, either in the hallway or a room in the middle of the building (preferably without windows).
3. Make yourself as small as possible by crouching down.
4. Use an object or your arms to protect your head and neck.
5. When possible, get under a piece of sturdy furniture like a desk and hold on to it.
6. Do not use elevators. If the power fails, you can get trapped inside.

Note: Buildings with long-span roofs (exceeding 12 m), such as manufacturing plants, warehouses, shopping malls, theaters or gymnasiums, are especially dangerous during tornadoes because the roof structure is supported solely by the outside walls. If this is the type of roof you’re under, try to get to a lower level or find a more secure structure to take shelter in.

What to do at home

1. Go to the lowest level of your house—the basement or a storm cellar if possible.
2. If there is no basement, go to a room in the middle of the house, preferably one without windows, and remain in the center.
3. Stay away from windows and keep them closed—despite popular myths, opening the windows during a storm will not equalize the pressure and can cause more damage.
4. Avoid taking shelter directly beneath an area with heavy objects on the floor, like a refrigerator or piano. It is possible for these objects to fall through the floor during a tornado.
5. Make yourself as small as possible by crouching down.
6. Use an object or your arms to protect your head and neck.
7. When possible, get under a piece of sturdy furniture like a heavy table and hold on to it.
8. A bathtub is a safe location during a tornado if the bathroom is deep inside your house and doesn’t have any windows. Note: If the wall of the bathroom is exposed to the outside (or the bathroom has windows), the bathtub is not an ideal place to shelter.
9. If you live in a mobile home, seek shelter elsewhere.

What to do if you’re outside

1. If possible, get inside a sturdy building and follow the instructions in the previous lists that are most appropriate to your type of shelter.
2. If you’re unable to find a sturdy building to take shelter in, stay close to the ground, preferably in a ditch or low-lying area.
3. Make yourself as small as possible by crouching or lying down in a ditch.
4. Use an object or your arms to protect your head and neck.
5. Watch out for flood waters that fill low-lying areas.
6. If there is a strong building (reinforced concrete buildings like a school) nearby but you’re unable to get inside, crouch as close to the structure as possible and take cover.
7. Tornadoes can change direction quickly and will toss things through the air. Be aware of your surroundings if you’re stuck outside.
8. Avoid areas with a lot of trees.

What to do if you’re in your vehicle

1. Park and get out of the vehicle.
2. Refer to the “What to do if you’re outside” instructions.
3. You can’t outrun a tornado, so do not attempt to beat or “drive out” of the storm.

Even after you’ve refreshed your tornado safety knowledge, it’s important to stay sharp. Perhaps you have heard there’s a tornado watch for days and you’ve become complacent to the risks, thinking nothing bad is going to happen because up to this point, it hasn’t. Stay as vigilant as possible throughout the entire tornado watch.

And don’t forget to spread the word to keep complacency at bay for your workers. Print these guidelines or incorporate them into a toolbox talk to ensure that your employees are safe in the event of a tornado, no matter where they are or what they expect this time of year.