As the dog days of summer warning is an alarm that a dangerous roll around, we get to witness one of nature’s most incredible phenomena—the thunderstorm. With huge cumulonimbus clouds rolling into the sky as afternoons slide by, these storms appear like a majestic, natural art piece on the horizon. The unfortunate fact, though, is that this beauty can be a beast. With the extreme weather dangers they often present, thunderstorms should be respected and prepared for.

Compared to other dangerous storms we experience in the U.S., thunderstorms are small. The average thunderstorm is approximately 15 miles in diameter and lasts about 30 minutes. Their rapid development and nature, though, make them dangerous on a variety of fronts. These include strong lightning, strong winds, hail and potential tornados. Thunderstorms most commonly develop in the spring and summer months, and are typically experienced in late afternoon and early evening. A thunderstorm is created when three factors merge—moisture, unstable warm air that rises quickly and the lift provided by weather fronts.

As a storm develops, the National Weather Service will watch it closely and begin to track it. They will first issue a watch, which means that conditions are ripe for a storm. Once a storm develops a specific set of characteristics, they will then issue a severe thunderstorm warning. This warning is an alarm that a dangerous storm is at hand. These characteristics include winds of at least 58 miles per hour or hail at least 0.75 inches in diameter. While common, only about 10 percent of thunderstorms are classified as severe each year, but these account for most of the damage and loss of life.

Multiple Threats

Severe thunderstorms have the potential of dropping a large amount of rain in a very short amount of time, and contribute to rising rivers, slick roads and diminishing visibility. Flash floods can occur instantly and be extremely dangerous, especially when driving. It only takes 12 inches of water to sweep away the average vehicle, and rain can come down in hard and heavy sheets, which make it nearly impossible to see, resulting in deadly accidents. If you are caught in a thunderstorm while on the road, pull over safely and as soon as possible. Never attempt to drive through flooded streets because it is impossible to predict how deep the water may actually be.

In addition to flooding rains, thunderstorms bring a slew of other hazards you must be prepared to handle. One of the first things we notice from a mature storm is thunder. While harmless in and of itself, thunder is an indication of lightning. Lightning kills roughly 10,000 people a year around the world and injures almost 100,000. It is an unpredictable threat that is found in any thunderstorm. According to the U.S. National Weather Service, lightning is the first thunderstorm hazard to arrive and the last to leave. Generally, lightning will strike within 10 miles of its home storm, but it does have the capacity to strike much further away if the conditions are right. The National Weather Service has detected lightning strikes as far as 50 miles from a storm’s base.

Lightning is incredibly dangerous because of the electrical charge it carries. The average lightning bolt carries up to 1 billion volts of electricity in every strike. Even a fraction of this power can easily kill a human being in an instant. A byproduct of the charge is heat. Reaching a temperature close to 50,000 degrees Fahrenheit, a lightning strike can burn through just about anything. Along with direct strikes, lightning can also be lethal through the wildfires it ignites.

Another danger that accompanies thunderstorms is high winds. According to the National Severe Storms Laboratory, damaging winds are classified as those exceeding 50 to 60 mph, and are often called straight-line winds to differentiate the damage they cause from tornado damage. Most thunderstorm winds that cause damage at the ground level are a result of outflow generated by a thunderstorm’s downdraft. Damage from severe thunderstorm winds account for half of all severe reports in the lower 48 states and is more common than the damage from violent tornados.

Wind speeds during a thunderstorm can reach up to 100 mph and produce a damage path extending for hundreds of miles. Anyone living in thunderstorm-prone areas of the world is at risk for experiencing this hazard. People living in mobile homes are especially at risk of injury and even death. Even anchored mobile homes can be seriously damaged when winds gust over 80 mph. Hail is a form of frozen precipitation that is often found to accompany thunderstorms. These pellets can range in size from that of a pea to a grapefruit or larger. The largest hailstone ever recorded in the U.S. measured 8 inches in diameter and weighed nearly 2 pounds. Mix in the fact that hail can fall at close to 120 mph and the danger becomes real. Hail causes approximately $1 billion in damage annually in the United States to houses, buildings, cars and crops. The costliest hailstorm in U.S. history caused an estimated $2 billion in damage (Kansas City, April 2001) from a single storm.

While not generally considered a lethal threat, there are other problematic issues associated with thunderstorms. Power outages lead the list in this category and can wreak havoc if they are long term. Lightning and high winds can down power lines and kick a community off grid for days, not to mention cause damage to homes and on the roads depending on where they fall.

The lack of electricity can become a serious issue if a person is elderly or has a physical condition requiring air conditioning. This leads into the second factor: humidity. The nature of a thunderstorm is based around moisture. As the storm hits, it leaves behind much of that moisture in the form of humidity. If the air temperature stays high, it can become a health issue to the elderly and the ill. This is one of the most common reasons for so many people being outside after a major storm. They are usually seeking respite from the wet heat inside.

Storm Prep 101

As thunderstorm season sets in, it is best to make plans for the worst. While many guidelines exist, some of the best information comes from There are a number of easy steps you can take to be prepared in advance and minimize the damages resulting from thunderstorms.

Know the warnings signs. As afternoon thunderstorms begin to develop, listen to the radio and watch the weather. Always have an emergency kit packed and ready to go. This should include a good flashlight such as the Olight M10 Maverick (, an emergency weather radio like the AcuRite portable NOAA weather radio (, blankets, water, non-perishable food, first-aid supplies, batteries, dry clothes and any medications you may need. Keep your property free of dead or rotting trees and branches that could fall and cause injury or damage during a severe thunderstorm. Have a family emergency action plan in the event you are separated during a storm. This is especially true for kids as thunderstorms can be very frightening.

If you’re under a severe thunderstorm watch, heed warnings and seek shelter when a thunderstorm warning is announced. Stop whatever you are doing and quickly move to shelter safely.

Use your battery-operated NOAA weather radio for updates from local officials, and avoid contact with corded phones and devices, including those plugged in for recharging. Cordless and wireless phones not connected to wall outlets are OK to use. Even better, try and avoid contact with electrical equipment or cords all together. Power surges from lightning can cause serious damage, so unplug appliances and other electrical items such as computers and turn off air conditioners. Similarly, plumbing and bathroom fixtures can conduct electricity, so do not wash your hands, do not take a shower, do not wash dishes or do laundry.

If you are outside, stay away from natural lightning rods such as a tall, isolated tree in an open area. Avoid hilltops, open fields, the beach or a boat on the water, and get inside as soon as possible. Take shelter in a sturdy building but stay away from windows and doors and stay off porches. Do not lie on concrete floors and do not lean against concrete walls.

If you are driving, try to safely exit the roadway and park. Stay in the vehicle and turn on the emergency flashers until the heavy rain ends. Avoid touching metal or other surfaces that conduct electricity inside and outside the vehicle.

Safe Escape

Once it is safe to do so, exit your shelter slowly. Flying debris can land anywhere and downed power lines may be present. Watch your animals closely and keep them under your direct control. If you must be on the road to go check on family or fetch supplies, never drive through a flooded roadway. Stay away from storm-damaged areas to keep from putting yourself at risk from the effects of severe thunderstorms. Stay away from downed power lines and report them immediately. Continue to listen to weather advisories for updated information or instructions, as access to roads or some parts of the community may be blocked. Help people who may require special assistance, such as infants, children and the elderly or those with access or functional needs.

Thunderstorms are just a fact of life in the United States and around the world. According to the National Weather Service, approximately 1,800 thunderstorms are occurring at any given time, resulting in about 16 million thunderstorms each year. They are a part of our existence and have even worked their way into our psyche. Astraphobia is the fear of thunder and lightning. It is more common than most people know and is a good indicator of the power that these storms have in our lives. By being informed and diligent, we can marvel at the magnitude of these storms while remaining safe.

This article was originally published in the SURVIVOR’S EDGE™ Fall 2015 edition. Subscription is available in print and digital editions here.

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