Positively charged ice crystals rise to the top of the thunderstorm, and negatively charged ice particles and hailstones drop to the lower parts of the storm. Enormous charge differences develop.
As the differences in charges continue to increase, positively charged particles rise up tall objects such as trees, houses, and telephone poles—and people. When the charge gets close to the ground, it is attracted by all the positively charged objects, and a channel develops. The subsequent electrical transfer in the channel is lightning.
That's not a good sign! Your best bet is to get yourself immediately indoors. Since light travels faster than sound, the thunder is heard after the lightning. If you see lightning and hear thunder at the same time, that lightning is in your neighborhood. If you see successive strokes of lightning in the same place on the horizon then you are in line with the storm, and it may be moving toward you.
Some lightning originates in the top of the thunderstorm, the area carrying a large positive charge. Lightning from this area is called positive lightning. Positive lightning is particularly dangerous, because it frequently strikes away from the rain core, either ahead or behind the thunderstorm. It can strike as far as 5 or 10 miles 8 or 16 kilometers from the storm, in areas that most people do not consider to be a lightning-risk area. The determining factor on whether a particular flash could be deadly depends on whether a person is in the path of the lightning discharge.
Although some victims are struck directly by the main lightning stroke, many victims are struck as the current moves in and along the ground. Seek shelter and avoid situations in which you may be vulnerable. When you see lightning, count the time until you hear thunder. If that time is 30 seconds or less, the thunderstorm is within six miles ten kilometers of you and is dangerous.
Seek shelter immediately. The threat of lightning continues for a much longer period than most people realize. Wait at least 30 minutes after the last clap of thunder before leaving shelter. Don't be fooled by sunshine or blue sky! People involved in activities such as boating, swimming, fishing, bicycling, golfing, jogging, walking, hiking, camping, or working outdoors all need to take the appropriate actions in a timely manner when thunderstorms approach. Here's what you need to know.
Tall, bright white clouds are "cumulonimbus clouds. If these clouds appear during a storm or in a gray sky, they could mean lightning. When you see lightning, count the seconds until you hear the thunder.
Keep doing this every time lightning strikes. You don't need to ensure you count in one second intervals; it's more important that you count consistently. If the time is getting shorter, that means the storm is approaching and lightning is coming your way.
If the lightning is heading your direction, you should immediately seek shelter. Just before lightning actually strikes, static energy is going to fill the air. If you look at your arms, you may see the hair on your arms standing on end. You may also feel a physical tingling sensation throughout your body, especially in your extremities. This is often the gut feeling that people get when they "sense" that something is impending. If your hair is standing up, you may have only a few seconds to protect yourself from lightning.
Though it may sound strange, you may taste something metallic in your mouth just before a lightning strike. Electrical stimulation in general can lead to a metallic taste, including electrical discharge from batteries. For more information on the number of deaths per year, please visit the NOAA website external icon. Lightning strike injuries are not well documented. However, FEMA estimates that about people are injured each year due to lightning.
Cell phones and cordless phones are safe to use during a lightning storm as long as they are not connected to an outlet through a charger. Do not use corded phones. Being underneath trees is the second leading cause for lightning deaths. For more information on safe shelters, visit our lightning safety tips page. Lightning can travel through plumbing.
It is best to avoid all water during a lightning storm. Do not shower, bathe, wash dishes, or wash your hands. Lightning victims are NOT electrified and you will NOT be electrocuted by touching someone who has been struck in a lightning storm. It is safe to touch a lightning victim and administer first aid immediately.
For more information, visit our Web page on administering first aid. Even if you do not see rain, you may still be at risk for lightning strike. Lightning often strikes outside areas of heavy rain and can strike as far as 10 miles away from any rainfall.
Many lightning deaths occur ahead of storms or after storms seemingly have passed. Remember, if you can hear thunder, you may be in danger of a lightning strike.
Lightning can strike the same place twice. In fact, lightning often strikes the same place repeatedly, especially a tall, pointy, isolated object. The Empire State Building is hit by lightning nearly times a year.
To stay safe inside a building:. To measure the distance of lightning, count the seconds between flash and thunder and divide by five; the number is how many miles the lightning is from you. During thunderstorms, lightning can strike up to 10 miles away. That distance is when you can just begin to hear thunder, which is why safety experts urge us to go inside as soon as we hear a distant rumble.
Many victims have been either heading to safety at the time of the fatal strike or were just steps away from safety. From the National Weather Service :. And in a story on lightning in The Week , Charlotte Huff also recommends to "look for a ravine or a depression. Spread out your group, with at least 20 feet between each person, to reduce the risk of multiple injuries.
Don't lie down, which boosts your exposure to ground current. Cooper, Mary Ann, et al. Auerbach, Elsevier, , pp. Jensenius, John S. Actively scan device characteristics for identification.
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