Lightning safety: are the old rules still valid? Crouch or don’t crouch?

Update, June 30, 2014: The National Weather Service clarifies it does NOT recommend the crouch. More info: Weather Service expert clarifies: The lightning “crouch” is not recommended

Lightning in the eastern sky behind Washington, July 11, 2011.

Lightning in the eastern sky behind Washington, July 11, 2011.

Original post: With the severe weather season in full swing, it’s probably a good idea to review the latest guidelines for lightning safety.

For many years, experts advocated that, when no shelter was available during a thunderstorm, one should lie flat on the ground.  Later, that idea was debunked, as we now know that although such an action reduces one’s height (a good thing), it greatly increases exposure to dangerous ground current, which can spread out from trees, etc.

About 4 years ago or more, John Jensenius, NOAA’s lightning expert, advocated using the “lightning crouch” as a last resort—and only as a last resort–for protecting oneself in an open field.  The idea was that with the “crouch,” there was minimal contact with the ground while one’s height was also minimized.  At the time, Jensenius admitted, however, that the advantage was only slight.

After interviewing Jensenius, I did a post about lightning myths and lightning safety and drew some criticism because it appeared to at least one reader that I was advocating the “crouch,”—but shouldn’t be–even though it was suggested by Jensenius as a last resort.

Now, in 2014, the tide has turned once more.  Jensenius now is totally opposed to the “crouch,” or the “squat,” as he now calls it—even as a last resort, or so it would seem.  He says that the latest thinking is that if you’re crouching on the ground, “you’re likely to get hit.”  Apparently, various NWS Web sites haven’t gotten the word yet.

So, aside from the still-valid myths referred to in my earlier post, what are some of the latest discredited lightning safety tips?

According to NBC News, who interviewed Jensenius recently, there are at least four other myths:

(1) Golfers are most at risk. They’re not, with fishermen being struck 3 times more often.

(2) The 30-30 rule can protect you.  This rule recommends that if you hear thunder within 30 seconds of seeing lightning, you should go indoors, because the lightning is too close. Also, you should stay there until 30 minutes after the last clap of thunder.  While the second part of this rule is still considered valid, the first part has been amended, so that people are now urged to go indoors at the first sound of thunder.  Another change that all National Weather Service sites don’t seem to be aware of.

(3) Going ahead with plans when a thunderstorm is imminent is OK.  Definitely not.  This is the # 1 mistake that most people—particularly men—make.  (Eighty per cent of lightning fatalities are men, according to Jensenius).

(4) On a day with potential lightning risk, one will hear the storm nearing.  Not always true.  Many factors can mask its approach, such as wind, highway and crowd noises, etc.

Then and now, Jensenius and other experts have continued to emphasize that lightning avoidance is the single most valuable behavior in the face of danger.  Delaying or canceling the activity is best, but if this isn’t possible (it should always be an option), then exposed individuals should have a pre-selected take-cover plan, meaning that an appropriate shelter would be relatively close by.

But what if it just isn’t possible to find any substantial shelter or automobile (metallic –roofed cars are among the safest)?  In that case, look for a stand of shorter trees, but keep some distance from the trees, Jensenius says. “If you’re with a group, spread out…this might actually increase the risk of someone getting hit, but if you’re all together and that area gets hit, there won’t be anyone who can help.  Avoid being, or being near, the tallest object in your immediate area, but don’t be out in the open or near isolated trees, either.”

Finally, Jensenius recognizes that trees are not always present.  Therefore, he says (contradicting his latest advice), crouching or squatting—in desperation only—may be attempted, although the risk reduction would be very slight.

Following are a few additional lightning statistics:

2014 lightning fatalities to date: 7

30-year average number of lightning fatalities*: 51

Odds of being struck by lightning in a given year: 1 in 1,000,000

Odds of being struck by lightning in a lifetime: 1 in 10,000

*although the average annual number between 2006-2013 was only 33.

Related: More Capital Weather Gang posts about lightning

Also on Capital Weather Gang

Typical summer thunderstorms likely this evening around D.C., a few could be potent