Meteorologists have compiled a map of 36 million places in the United States where lightning struck.

The day was warm, maybe even a little humid, and the high clouds in the distance looked like cauliflower. You hear a sharp cracking noise, like the sound of a bat hitting a baseball, or a low hum, like a truck driving down the highway. A distant thunderstorm and its lightning make themselves felt.

Lightning appears during thunderstorms at least 60 times per second in different parts of the world, sometimes even near the North Pole.

Each giant spark of electricity shoots through the atmosphere at a speed of 320,000 km/h. It's hotter than the surface of the Sun and produces thousands of times more electricity than the outlet that charges your smartphone. This is why lightning is so dangerous.

Lightning kills or injures every year about 250,000 people around the world, most often in developing countries where many people work outdoors without lightning protection shelters nearby. In the United States, between 2006 and 2023, the number of deaths caused by lightning every year was on average 28 people. Every year, insurance companies pay out about 1 billion dollars USA for claims for damages caused by lightning and about 4 million acres the earth burns as a result of forest fires caused by lightning.

However, estimates of the number of lightning strikes in the United States vary widely, from about 25 million per yearcited by meteorologists since the 1990s, up to 40 million per year, reported by the Centers for Disease Control and Prevention. This makes lightning safety and protection efforts more difficult.

I am a meteorologist whose research involves studying the behavior of lightning. In the new study, my colleagues and I used six years of data from the National Lightning Detection Network, which we believe has become accurate enough to provide a more accurate picture of lightning strikes across the United States. This knowledge is essential to improve forecasts and prevent damage.

How many lightning strikes in the USA

To get a clearer picture of the frequency of lightning strikes, it is necessary to define what a lightning strike is.

Imagine that you are looking out the window at a thunderstorm, and lightning strikes the ground from a cloud nearby. Lightning seems to flicker.

An isolated flash of lightning is considered to be all lightning passing from clouds to the ground, which occurs within 1 second within a radius of 10 km. Every flicker is a lightning strike. Each blow can hit one or more points on the ground, and in one channel several strokes may occur.

Lightning is a large electrical discharge trying to disperse electricity in a cloud, so if there is a lot of electricity accumulated in the cloud, there can be a lot of lightning that helps get rid of it.

Based on data collected over six years National Lightning Detection Networkwe found out that average In the United States, there are 23.4 million flashes, 55.5 million ground impacts, and 36.8 million ground impact points each year.

Where does lightning strike most often?

The main components of a thunderstorm are warm, moist air near the ground, cooler, drier air above it, and conditions that allow the warm, moist air to rise. Anywhere these components are present, lightning can occur.

This occurs most often in the Gulf Coast region, where sea breezes contribute to thunderstorms on most summer days. Florida in particular is a hot spot for cloud-to-ground lightning strikes. In the Miami-Fort Lauderdale area alone, more than 120,000 lightning strikes were recorded in 2023.

The central and southern regions of the United States are not as prone to lightning, but they experience more thunderstorms and lightning strikes than the northern and western parts of the country, although lightning in the west can be especially destructive when they occur. cause forest fires.

The cool waters of the Pacific Ocean, in turn, contribute to the lack of thunderstorms on the West Coast.

Counting lightning strikes

To count how many lightning strikes the ground and where they strike, you need to be able to detect them. Luckily, cloud-to-ground lightning is fairly easy to spot—in fact, you've probably done it too.

When lightning flashes, it acts like a giant radio antenna that sends electromagnetic waves—radio waves—around the world at the speed of light. If you have an AM radio on during a thunderstorm, you may hear a lot of static.

The National Lightning Detection Network uses strategically placed antennas to listen for these radio waves created by lightning. It is currently capable of detecting at least 97% of the cloud-to-ground lightning that occurs in the United States.

The number of lightning strikes varies from year to year depending on prevailing weather conditions during the spring and summer months, when lightning is most common. There is not yet enough accurate data from the United States to say whether lightning is trending toward an increase or decrease in the number of lightning strikes. However, changes in the frequency and location of lightning can be an indicator of climate change affecting storms and precipitation, which is why the World Meteorological Organization has called lightning “important climate variable“.

Better data improves security

Meteorologists and emergency managers can use this new data and our analysis to better understand how lightning typically affects their regions. This will help them better predict risks and prepare the public for thunderstorm hazards. Engineers are also using these results to create better lightning protection standardsto protect people and property.

Lightning strikes are still unpredictable. So to stay safe, remember: When you hear thunder, go indoors.