It's that time of year again, so I'll dust off and mildly
redact an article I first posted in 1998. The somewhat
longer version is at
radix.netlightning.run.htmlOpen ↗, and that
one has some functional links.
In article
<[email hidden]>,
RickM666 said:Having just returned from a noon run in which I was
caught in a thunderstorm, I wondered if anyone had any
scientific opinions on what sort of a target for
lightning is presented by a runner proceeding at, say, 7
minutes per mile.
About the same as 10 minutes per mile, walking, or
standing. If you're out in a clear flat area, you're a
target. If you're next to a tree, it's a target and you
are too close to a target. Same rules apply to runners as
others w.r.t. lightning. If the lightning starts up, head
for shelter now. If no shelter is close enough to reach
before the lighting strokes get close, head for the lowest
ground you can find and get down.
'Close' is, unfortunately, a very broad range. Count the
seconds between stroke and thunder. 5 seconds is 1 mile.
If you're at less than 5 seconds, get shelter
_immediately_. Since lightning strokes routinely hit 5-10
miles apart, even out to 25-50 seconds you're still too
close for confidence (and at that point, the thunder may
be hard to hear).
That outer range may sound extreme. On the other hand,
people have been hit by lightning while the causative
storm was 30 km away. Not as conservative as you might
think, therefore. Since I grew up in tornado alley, I
am very cautious of thunderstorms. Very interested,
but cautious.
Added 23 January 1999: This subject generated a lot more
discussion in rec.running, not all of it very well informed.
So some additional points regarding lightning safety.
See the Red Cross or National Weather Service pages for more
on lightning safety.
If you do take reasonable precautions about lightning, you
have very little to worry about. And the reasonable
precautions are easy: get inside a well-built building and
stay off conductors (metal pipes and wires) which reach
outside. If you can't get to a building, get inside a
metal body car. (Note these two are not contradictory. The
thing to avoid is being part of a _path_ between the
lightning and the earth. If you're _inside_ a conductor,
as in the car, then you're not part of a path. If you're
_holding_ a conductor, then you may represent a shorter
path to the earth then the thing you're holding and then
could be in danger.)
I'm advocating a 10 mile (if you're confident of hearing
faint thunder) or 30 minute (- 30 minutes since the last
thunder you did hear, if you're not certain of
hearing/seeing distant lightning) buffer zone between you
and the edge of the storm. Some of the discussion focussed
on this being so large as to prevent you from getting your
run in for that day. My first concern in running is health,
and getting hit by lightning is not healthy, so no problem
deciding what to do there.
But even if you're committed to running 'regardless',
lightning is not a major interruption. Storms with lightning
are primarily thunderstorms (surprise), _and_ these storms
are not, individually, long-lived. 90 minutes is a _long_
thunderstorm. Add 30 minutes either side, and for a _long_
storm, you might lose 2.5 hours of the day for your run.
Fine, run at 7:30 instead of 5:00, or vice versa.
Thunderstorms are most common in the late afternoon, so just
shift your running to early afternoon or early evening and
you're set. (Recall too that thunderstorms are most common
in summer, when the sun is out the longest so you can adjust
your schedule most easily.)
There was also some ill-considered statistical reasoning. I
wouldn't go in to it except the line of thought seemed
popular among otherwise knowledgable people. The mistaken
reasoning was to say, "Only about 100 people per year are
killed by lightning. That's awfully rare, so I'll get my run
in regardless of the lightning and take my chances with the
lightning." The error is simple -- Almost nobody, at any
given time, is in a position where they _could_ be hit by
lightning. Last month, for example, I could not possibly
have been hit by lightning, regardless of what I did
outside, since there wasn't any lightning to be hit by. The
situation is analogous to getting killed by an alligator.
Very few people are killed by alligators. The person
reasoning above is concluding (effectively) that it is ok to
go to a swamp and throw rocks at an alligator, since very
few people are killed by alligators. If there is, or
recently has been, lightning in your area, then someone is
throwing rocks at a nearby alligator. Time to take some
safety measures.
--
Robert Grumbine radix.net~bobgOpen ↗ Science faqs and
amateur activities notes and links. Sagredo (Galileo
Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less
appreciated than they would be had they been presented in a
more abstruse manner." Two New Sciences