When temperatures soar, the evenings are often filled with thunderstorms. It seems as if they appear out of nowhere banging and booming and scaring the daylights out of children and dogs. Here in the Mid-Atlantic, this is becoming a frequent occurrence. So far in the United States, this year 13 people have been killed and 99 injured after being struck by lightning. To prevent the threat of a lightning strike, there are precautions that can be taken. I look to such organizations as the StruckByLightning.org, National Lightning Safety Institute, Electric Shock and Lightning Strike Survivors International, and the National Weather Service as sources of information to help me identify the hazards and ways to control them.
- Struck By Lightning.org http://www.struckbylightning.org/
- National Lightning Safety Institute (NLSI) http://www.lightningsafety.com/
- Electric Shock and Lightning Strike Survivors International, Inc http://www.lightning-strike.org/DesktopDefault.aspx
- National Weather Service http://www.lightningsafety.noaa.gov/
There are some interesting pieces of information that can help us make sense of lightning. It is always good to know how far a thunderstorm is away from. You can find out by measuring lightning’s distance using the “Flash/Bang” technique. For every five seconds from the time you see the lightning flash to hearing the thunder means that the lightning is one mile away. Let’s look at two examples: a Flash/Bang of 10 seconds = 2 miles and a Flash/Bang of 20 seconds = 4 miles.
Now that you know that, how far away is far enough? The average distance between successive cloud-to-ground flashes is greater than we previously thought. The old recommended safe distance from the previous flash was 1-3 miles. New information suggests that a safe distance should be 6-8 miles. To complicate matters around 40% of cloud-to-ground strikes are forked sending two and often more attachment to the earth meaning more lightning strikes. Don’t forget about the hazards of horizontal lightning, which can arch more than 60 feet from where the actual strike occurred.
The National Lightning Safety Institute recommends the 30/30 Rule. This rule says that you should suspend activities at a Flash/Bang of 30 seconds or 6 miles, or when first hearing thunder. They also say that outdoor activities should not be resumed until 30 minutes has past from the last observable thunder or lightning. I know what you are thinking, but this is a conservative approach and perhaps not practical in all circumstances.
What if you are suddenly exposed to nearby lightning? The National Lightning Safety Institute recommends adopting the so-called Lightning Safety Position. The Lightning Safety Position means stay away from other people, take off all metal objects, crouch on the ground with feet together, head bowed, and place your hands on your ears.
When lightning threatens, standard safety measures should include: avoid water and all metal objects; get off the high ground; avoid solitary trees; and stay off the telephone. A fully enclosed metal vehicle – van, car or truck – is a safe place.
Take the shock out of lightning strikes…okay I’m sorry about that pun. Take the fear out of lightning strikes by being prepared. Taking the precautions in this blog post can prevent or reduce the threat of lightning strike. I also recommend you check out the web site in this blog post for additional information.