Sunday, June 28, 2015

Lightning Safety - Rules to Live By

I certainly had an appreciation for lightning throughout my career as a meteorologist, but probably not enough as I should have. I've been outside when I should not have been, or stood on my porch watching thunderstorms as many of us probably have done. As I was gathering information for a web page on lightning and these blog posts, it was clear to me that I haven't been careful enough. The last two blog posts hopefully have made it clear - you don't mess with lightning - ever. Ben Franklin was one lucky guy, to say the least.

Take the threat of lightning seriously. Since most deaths and injuries occur outdoors, we'll look at these safety rules first.

“When Thunder Roars, Go Indoors!”

Credit: NOAA/NWS
This slogan was adopted by the National Weather Service several years ago, and while on the surface it might seem a little corny it gets right to the point .

If you are outdoors, find shelter in a nearby safe building or metal-topped vehicle with the windows closed. If you can hear thunder then you are at risk from lightning. The furthest distance from a lightning strike you can typically hear thunder is about five miles and seldom more than 10 miles, depending on atmospheric conditions. That "distant" rumble of thunder could only be several miles away, and just because you can’t hear thunder doesn’t necessarily mean you are safe. Lightning bolts are known to arc out tens of miles from the parent thunderstorm and may seemingly "come out of the blue". Stay inside at least 30 minutes after you last hear thunder.

Many injuries and fatalities from lighting were people who were headed to shelter but started to seek shelter too late. Pay attention to the weather and at the first sound of thunder or flash of lightning head to shelter. Fully enclosed buildings with plumbing and wiring provide the best protection. A hard-topped metal vehicle also provides protection. If you cannot find safe shelter there are some steps you can take to lessen your risk. However, it bears repeating that no place is safe outdoors in a thunderstorm.
  • Avoid open fields, the top of a hill or a ridge top.
  • Stay away from tall, isolated trees or other tall objects. If you are in a forest stay near a lower stand of trees.
  • If you are in a group, spread out to avoid the current traveling between group members.
  • If you are camping in an open area, set up camp in a valley, ravine or other low area. However, be aware of flash flooding potential in low-lying areas. Remember, a tent offers NO protection from lightning.
  • Stay away from water and wet items such as ropes, as well as metal objects such as fences and poles. Water and metal do not attract lightning but they are excellent conductors of electricity. The current from a lightning flash easily travels long distances.
    Crouching doesn't make you any safer outdoors. Run to a substantial building or hard topped vehicle. If you are too far to run to one of these options, you have no good alternative. You are NOT safe anywhere outdoors.

    However, the National Outdoor Leadership School along with NOAA recommends the lightning position when getting to safety is impractical or not possible. This may help minimize injuries if you are struck. You can download the complete brochure on backcountry lightning risk management here.

     Lightning Safety Indoors

    • Stay off corded phones. You can use cellular or cordless phones.
    • Don't touch electrical equipment such as computers, TVs, or cords. You can use remote controls safety.
    • Avoid plumbing. Do not wash your hands, take a shower or wash dishes.
    • Stay away from windows and doors that might have small leaks around the sides to let in lightning, and stay off porches.
    • Do not lie on concrete floors or lean against concrete walls.
    • Protect your pets. Dog houses are not safe shelters. Dogs that are chained to trees or on metal runners are particularly vulnerable to lightning strikes.
    • Protect your property. Lightning generates electric surges that can damage electronic equipment some distance from the actual strike. Typical surge protectors will not protect equipment from a lightning strike. The National Lightning Safety Institute has information on protecting your home and electronics from lightning. Do not unplug equipment during a thunderstorm as there is a risk you could be struck.

    You can find more information at the Lightning Safety page from the National Weather Service.
    If all of this is not enough to convince you to be careful, there are plenty of videos on YouTube showing the incredible power of lightning. Here's one of them: Lightning video

    Next: Lightning data and more information

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