The probability of being hit by lightning is low, but the conditional probability* may be much higher.
As a Utah resident, I can tell you why the death rate is higher in these dry western states.
First, lightning often strikes exposed hilltops, mountaintops, cliffs, and so on. Utah has a lot of those. Also, they’re scenic and accessible, so we have a lot of people out on them.
Second is virga. Easterners don’t usually even know what this is. Virga is when a storm drops rainfall and it evaporates before hitting the ground. We have a lot of virga in Utah. The thing is with virga, even though you’re dry, that’s a real live storm up there.
Third is visibility. Where I live, I can see for 60 miles on a bad day. It’s routine for me to be able to see multiple storms, separated by clear sky. And, it can be really easy to stop worrying about lightning when you see lightning, and count to over 100 before you hear thunder. Lightning routinely strikes as much as 10 miles from a storm, and up to 50 miles (who knew!). So, in Utah, not only can you see multiple storms, you can be hit by them too.
Fourth, there is a lot more lightning in sub-tropical areas, but there’s also a lot more rain. I lived in Louisiana for almost a decade: if there is a thunderstorm outside, you simply don’t go outside because it is like walking into a running bathroom shower with your clothes on. You wouldn’t jump into a pond fully clothed, and in Louisiana you don’t go out in the rain if you can avoid it because sometimes you’ll get that wet in a minute or two. This doesn’t happen out west, so people are outside more when there’s lightning.
Via Marginal Revolution via Laura McLay† at Punk Rock Operations Research.
* Probability is the chance of something happening. Conditional probability is the chance of something happening when you know some other information. Ben Franklin wasn’t dumb because the probability of being hit by lightning was high, but because the conditional probability of being hit while flying a kite is much higher.
† Do you ever wonder if some people’s teenage years would have been easier if they changed their names?
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