Florida is the lightning capitol of the United States and experiences thunderstorms on nearly one-third of the days in a year. Its unique geography is a key reason why Florida earns this distinction, especially during the summer. The Gulf of Mexico, to the west, and the Atlantic Ocean, to the east, surround the state and help to keep a warm and moist environment in place. This environment combines with strong summer sunshine, which heats the ground and causes warm air to rise. This creates small frontal boundaries along the east and west coasts, called sea breezes. These sea breezes push inland through the afternoon and allow thunderstorms to develop along the boundary. These boundaries often collide over the Central Florida Peninsula and generate additional thunderstorms that could become large and severe. Because thunderstorm activity peaks in the summertime, when the most people are working outdoors or enjoying outdoor activities, Florida often leads the nation in injuries and fatalities from lightning.

What Causes Lightning?

Within the thunderstorm, there are updrafts, where the air rises, and downdrafts, where the air falls. As the air in the updraft lifts higher, the small water droplets in the air freeze into small ice crystals and pellets. The ice particles collide with each other as they remain suspended in the updraft, and this friction causes an electrical charge difference within the cloud. The negative charges settle near the base of the cloud. The positive charges lift to the top of the cloud, and into the anvil of the thunderstorm. As the thunderstorm moves over the ground with this charge difference, it causes the ground and the objects on it to become positively charged. When the difference between the charges becomes too large, an electrical current begins to move between the cloud and the ground.

The visible flash of lightning occurs when the currents connect and discharge the energy. The currents look for the fastest route to make the connection. This is why tall objects, such as buildings and trees, will tend to be struck over shorter objects in the same area.

The speed of light travels much faster and farther than the speed of sound. This is why you see the flash of lightning first, and then hear the thunder. This is also why you can sometimes see lightning in the distance, but never hear the thunder with it. This is usually called heat lightning. Because of the delay between them, you can determine how far away the flash of lightning is by counting the number of seconds between the flash and when you first hear the thunder. For every five seconds counted, the lightning is one mile away.

Lightning Dangers

All thunderstorms contain lightning, regardless of the severity of the storm. Lightning can strike a person, a tree, or an object either on the ground or in the air. Over the last 10 years, lightning has killed an average of 39 people each year across the United States. Florida averages 6 deaths and 39 injuries a year. Lightning has also averaged over $6 million in damages each year to property in Florida.

Most people that are struck by lightning are not killed, but suffer significant injuries such as burns to their skin and, in some cases, cardiac arrest. It is important to remember that after a person is struck, they do not continue to carry an electrical charge and emergency medical services, if necessary, should be immediately performed.

Lightning is also dangerous because it can strike more than 10 miles away from where it is raining. Due to different winds in place near the top of the storm, lightning generated from the top of the thunderstorm can be displaced more than 10 miles away from the storm base, where it is raining. It is these lightning strikes that seemingly come from the “clear blue sky”. These “Bolts from the Blue” can be more dangerous since, as it is not raining in the immediate area, they can catch people off-guard.

Lightning Safety

A darkening cloud building high into the sky is often the first sign that lightning may strike. It is important to be observant while outside to keep yourself safe. Once you see lightning or hear thunder, you should immediately go inside a house, building, or other enclosed structure. A covered but not enclosed area, such as a dugout or awning, does not offer you protection from lightning. Once you are indoors, do not use any corded electrical devices, avoid using plumbing, and stay away from doors and windows. The electrical current from lightning can travel inside through wires, cables, and pipes.

If you are caught outside when a thunderstorm approaches and cannot make it indoors quickly, avoid open areas, such as a golf course or sports field, as these are the most dangerous places to be. This is because lightning tends to strike the tallest object in the area, which, in an open area, would be you. This is also why it is dangerous to stand under a tree in a storm. When you can’t make it into an enclosed building, the next best option is to get into a vehicle with a hard-topped roof.

It is equally as dangerous to be caught on the open waters of a lake or the ocean when a thunderstorm is approaching. Try to get back to land and find a safe building or, if possible, a safe vehicle. If that is not possible, then go inside the boat’s cabin and stay away from metal and all electrical equipment.

The key to staying safe from a lightning strike is to review the weather forecast before you go outside, and then monitor the sky conditions, looking for darkening skies and listening for distant rumbles of thunder once you are outdoors.

The best lightning safety rule is this: If thunder roars, go indoors!

Lightning Safety Awareness Week is June 24-30, 2012

More information about lightning hazards and what you can do to protect yourself and others can be found at
http://www.lightningsafety.noaa.gov and http://www.floridadisaster.org/.

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