How to Know a Tornado is Coming?

April, May, and June are the three most active months for tornadoes in the U.S. comprising more than half of the annual average of 1,333 twisters

Is a tornado coming? An RV is not a safe place to be during a tornado. Here are warning signs and how to stay safe in the face of a tornado.

Tornado season is here! How do you know if a tornado is coming? 

Here is my guide to all things tornado! I cover the tornado warning signs and how to stay safe during and after one occurs. 

What is a tornado? 

I know most of you know this but you’d be surprised how often this question is searched for in Google! I did say this guide is for all things tornado so here’s a quick definition.

A tornado is a violently rotating column of air that reaches from a thunderstorm to the ground beneath it. Most tornadoes are thin but some can be greater than two miles wide. A tornado hits when warm air collides with cold air.

Is a tornado coming? © Rex Vogel, all rights reserved

Tornado season

Tornadoes can occur in the U.S. at any time throughout the year but there’s a distinct seasonal peak in tornadic activity and it starts in April. Long-term severe weather records show April, May, and June are the three most active months for tornadoes in the U.S.

Between 1991 and 2020, an average of 1,333 tornadoes were documented across the country each year of which more than half―54 percent―occurred between April and June.

Looking back on history, May is typically the most active month for tornadoes averaging 294 each year. That’s followed by April and June, each with an average of 212 tornadoes.

But remember―these are just averages based on a 30-year period and the weather doesn’t always follow what’s considered to be average.

Different weather patterns that set up each spring can cause the number of twisters between April and June to be significantly greater or much fewer than the 718 tornadoes that are typical during those three months.

Is a tornado coming? © Rex Vogel, all rights reserved

Where do most tornadoes occur? 

Tornado outbreaks during spring are most common when a southward dip in the jet stream punches into the Plains or Midwest and warm, humid air from the Gulf of Mexico surges northward out ahead of it at the surface.

A stronger jet stream can be fuel for extreme weather adding spin and energy needed in the atmosphere that will allow for thunderstorms to grow and intensify, potentially developing into supercell thunderstorms that could produce tornadoes if wind shear―the change in wind speed and/or direction with height―near the surface is particularly strong.

By the spring, the jet stream is migrating northward out of the South and setting up more frequently over the Plains and Midwest as it retreats toward the Canadian border for the summer.

That’s why the potential for tornadoes increases in Tornado Alley during the spring while the risk of tornadoes decreases for the southern U.S.

The term Tornado Alley has been given to the broad area where most tornadoes occur in the United States. The boundaries of Tornado Alley change depending on the criteria you use to define it. 

Generally, the region includes central Texas stretching horizontally through Oklahoma to northern Iowa. Then from central Kansas and Nebraska eastward to the west edge of Ohio. 

The U.S. tornado threat shifts from place to place during the year. The Southeast states are threatened during the cooler months. The southern and central Plains are most at risk in May and June. The early summer is a risky time for the northern Plains and Midwest areas. 

While tornadoes generally stay in these regions they have occurred in all fifty states!

Is a tornado coming? © Rex Vogel, all rights reserved

Tornado watch and tornado warning

Tornado watch

A Tornado Watch is issued by the meteorologists at the NOAA Storm Prediction Center. They watch the weather all day, every day across the U.S. for signs of severe weather. A watch can cover parts of or entire states. 

If you know there is a chance of severe weather, you can tune into NOAA Weather Radio to hear when an advance warning is issued. Many survival radios have the seven NOAA Weather Stations pre-programmed for your convenience. 

Tornado warning

A Tornado Warning is more urgent. It is issued by the NOAA National Weather Service Forecast Office meteorologists watching a designated area nonstop. It means that radar or spotters have picked up on an actual tornado that is threatening people or property. 

A Tornado Warning means that you are at risk of danger and need to seek an immediate storm shelter. A warning can include parts of counties or several counties. When in an area issued with a Tornado Warning be sure to watch for the tornado warning signs. 

The National Weather Service cannot always predict a tornado nor give much warning. That is why it is a good idea to be able to spot the warning signs of tornadoes yourself. Advance planning can also mean the difference between life and death. 

Is a tornado coming? © Rex Vogel, all rights reserved

Here are a few things to learn how to spot if you think a tornado is coming your way.

1. Wall cloud

You may see a wall cloud or the lowering of the base of the thunderstorm. Be especially cautious if the wall is rotating. 

2. Debris cloud

Even if a tornado is not visible look for a whirling dust or debris cloud near the ground which can indicate a tornado without a funnel. 

3. Large hail

Large hailwith the absence of rain can be an indicator of an impending tornado.

4. Heavy rain

When hail or heavy rain is followed by a quick, intense wind shift or a dead calm be watchful. This can indicate a thunderstorm as many times they are wrapped in precipitation and cannot be seen. 

5. Still weather

Many times before a tornado strikes, the wind speeds will die down producing a quiet, still air. Many report this as eerie silence. Others call it the “calm before the storm.”

6. Roaring noise

A tornado can produce a loud rumbling sound that is similar to the loud roar of a freight train. This can occur during the day or night. 

7. Funnel cloud

A rotating extension of the cloud base can signal the formation of a tornado.

8. Dark sky with greenish tint

The sky may appear dark and have a greenish hue.

9. Small and bright, blue-green flashes

At night, pay attention to small, bright, blue-green flashes near ground level. That could indicate power lines are being snapped by strong winds or a tornado. 

Is a tornado coming? © Rex Vogel, all rights reserved

What to do if you are caught in a tornado

Tip #1: When referring to tornado safety, your stationed RV is similar to a mobile home. It’s even less safe. If you are camping somewhere and find yourself at risk of a tornado get out if possible. 

Tip #2: While you do not want to be exposed outdoors you do want to try and find the safest place possible. The best places are underground shelters or sturdy, permanent buildings. 

Tip #3: If you are driving your RV or other vehicle and get caught near a tornado, it can also be dangerous. Your best-case scenario is to try and drive out of the tornado’s path. To do this, drive at a right angle to the tornado if at all possible. 

Tip #4: If you get caught in high winds or hit with flying debris, park the vehicle as quickly and safely as possible. Lower your head below the windows. Cover your head and hands with a blanket or coat. 

Tip #5: If you spot an area lower than the roadway, leave your vehicle and lie down in that area. Cover your head with your hands. 

Tip #6: If you are in the outdoors, try and locate some sort of storm shelter in a sturdy building. If that is not possible, lie down at the lowest level you can find.

Tip #7: Try to avoid trees and vehicles and cover your head with your arms. 

Tip #8: Invest in a Survival Radio before you leave on your next road trip whether heading toward Tornado Alley or not.

Tip #9: For more helpful information, refer to the NOAA’s Tornado Safety Guide.

Is a tornado coming? © Rex Vogel, all rights reserved

What to do after

Once the tornado passes, assess the damage. Look and smell for a gas leak and move away if needed. 

If you can stay put and wait for medical personnel or law enforcement. Help any injured people that you can. 

If you haven’t already, turn on your radio and tune in to NOAA weather radio or local radio station. 

If you must drive out of the area, be careful to watch for any downed power lines. 

Worth Pondering…

Outside the rain began to pour in sheets, and the wind howled. Giant pieces of hail began to pelt the building—banging off the skylights so hard that Simpson worried the glass might shatter. Then, as it had earlier in the day, the wind briefly let up. It was then Simpson heard a sound she had dreaded—a sound she couldn’t believe she was actually hearing. It was 2:40 p.m. and the tornado sirens in Moore started to wail.

―Holly Bailey, The Mercy of the Sky: The Story of a Tornado