Lightning Does Strike Twice —
Revisiting "Thunder? I Wonder…"
By Tamia Nelson
September 13, 2011
I suppose I shouldn't have been surprised by the number of letters I got around "Thunder? I Wonder…," my recent column on minimizing the risks to paddlers from electrical storms. After all, it was published in early August, a prime month for thunderstorms throughout Canoe Country, and most paddlers have a few tales to tell about the storms they've weathered.
The take‑home message of my earlier piece was simple, and it echoed the advice offered by the US National Weather Service: If you can hear thunder, you're already at risk. So don't hang around waiting to see which way the storm is heading. Get off the water. Now!
There you have it: 140 characters in all. Short and tweet. Of course, that really doesn't exhaust the subject, does it? And my article went on at some length. As did the readers who wrote to me afterward, many of whom had stories which illustrated the points I'd made in my column. Some raised troubling questions, too.
Which is why I'm revisiting the subject now. After all, the decisions you take when a storm approaches can make the difference between life and death. And while the overall risk is very small — car crashes kill roughly 400 times as many people in the States as lightning every year, yet few Americans quake with fear when they buckle up — thunderstorms aren't exactly rare. The danger is real, in other words. That being the case, I figured a second column on the subject was warranted, if only to give interested readers a chance to say their piece.
And what better place to begin than with …
A Question About Numbers
There's more to thunderstorms than thunder and lightning, of course. They also bring heavy rain and strong winds in their train, and that got Terry Todd thinking:
Reading [your] article raised the question in my mind as to the likelihood of being struck by lightning while paddling. What are the statistics? Does it really happen? Personally, I would be much more alarmed by the possibility of high winds and threatening waves generated by such a storm than by the possibility of a lightning strike. It's not like I have a 25‑foot aluminum mast sticking up from my canoe. I would appreciate your expertise on this question.
The numbers game is never easy to play. But since I've written about meeting the dangers created by high winds and heavy seas in at least one earlier article, I'll concentrate on the numbers here. A comprehensive, if somewhat dated, tally of "lightning‑associated deaths" for the US can be found in an archive at the Centers for Disease Control website. Unfortunately, its value is somewhat limited, at least for our purposes. Although the report's compiler does note that 52 percent of lightning fatalities occurred while the victim was "engaged in outdoor recreational activities," there's no further breakdown. So the CDC data shed little light on the likelihood of being struck while paddling. However, another source makes the (unattributed) assertion that "around ten percent of the lightning deaths in the US have been in or near the water." If true, this suggests something about the magnitude of the risk of being struck. One thing at least is certain: It DOES happen, as the death of a Missouri canoeist following an "indirect lightning strike" on July 30, 2011, illustrates. A somewhat garbled account of this tragic incident can be found by scrolling through the pages at the Struck by Lightning website. You'll need to be patient, though. The site's pages load very slowly, even with a broadband connection.
What's my take on all this? While it's impossible to quantify the absolute magnitude of the risk to paddlers from lightning strikes, given the limitations of the data, the danger is there. And the good news? It's relatively small. Still, why gamble unnecessarily with your life? Given that the risk of injury or death can usually be reduced by getting off the water at the first sign of an approaching storm, that seems the prudent course to me. (As luck would have it, a meteorologist has recently addressed this question at some length in the Paddling.net forum. His post is well worth reading.)
I think we've run the numbers about as far as they can take us. Now let's get up close and personal with the real villain in the piece. In other words, let's explore …
The Electrodynamics of Lightning
Reader Mitch Rohse has been wondering if he might not be better off in his boat than on shore. Here's what he has to say:
It seems to me that the decision whether to get off the water or not should rest on matters of conductance and grounding. The better grounded you are, the more likely you are to become a lightning rod, right? So, if I'm in a plastic boat using a fiberglass or carbon‑fiber paddle, I'm an imperfect ground. I don't offer lightning much of a path to travel from sky to earth. But if I'm sitting or standing on shore in wet paddling gear, then I become a pretty good ground. It thus would seem that I am more likely to get struck by lightning by being a landlubber rather than a paddler. At least, that's my theory. I wonder what others might say of such logic.
And so do I, since Mitch's provocative hypothesis takes me well outside my areas of expertise. I'm always keen to learn more about natural phenomena, however, and the electrodynamics of lighting are a fascinating and complex topic. Happily, a useful and relatively accessible summary can be found in Lightning and Sailboats. (Like the pages at Struck by Lightning, this page, too, takes a good long while to load, so you'll need to be patient.) As the name suggests, it's written for sailors, but much of the material is relevant to paddlers, as well. The author's conclusions can be summarized as follows: Plastic hulls simply don't offer meaningful protection in the event of a strike. But are you really safer if you're hunkered down on shore? The consensus of expert opinion — at least the expert opinion I've seen — is that, yes, you are. Safer, but not safe. Unless you can take shelter in a vehicle or substantial structure (tents don't count, I'm afraid), you'll still be at risk. It's not a very comforting thought, but that's the way it is. For the record, I wouldn't bet my life on carbon‑fiber's insulating qualities, either. The stuff is actually a pretty good conductor. The first light bulbs had carbon‑fiber (actually carbonized cotton thread) filaments, in fact.
OK. Plastic hulls don't protect you from lightning strikes. But what about folks who ply the waters in those wonderful, venerable "tin tanks"? Are they at increased risk? In particular, …
Does an Aluminum Canoe Make a Dangerous Shelter?
John Peters put the question this way:
Is it still recommended that you seek shelter under your canoe if it's made of aluminum? I know you need to be cautious with fishing rods being held up, but I was not sure if the aluminum boat itself would be more of a hazard than Kevlar or fiberglass.
First a reminder: While an upturned canoe can keep the rain off your head, it won't offer any protection against a lightning strike, whatever material it's made of. But does taking shelter under an aluminum canoe actually INCREASE the danger? To be honest, I don't know. John Gookin, author of a National Outdoor Leadership School publication entitled "Backcountry Lightning Risk Management" [PDF], warns readers to "avoid long conductors[,] … particularly those … on or near the surface." That sounds to me like it might include 17‑foot aluminum canoes, but Gookin then goes on to list things like wire fences, power lines, and railway tracks. Would his warning also apply to a paddler's faithful Grumman? I think it might, but, again, I really don't know. Maybe someone reading this article will have the answer. If so, I hope he (or she) will drop me a line so I can pass the word.
One regular In the Same Boat reader has a more than casual interest in the dangers posed by thunderstorms. He's James Stone, a career firefighter with the US Forest Service, and his is therefore …
A Professional's Point of View
James has been battling wildfires throughout the western United States for several decades now. A lot of those fires begin with lightning strikes. So it's no surprise that the Forest Service takes a close interest in electrical storms, both to better understand the genesis of wildfires and to minimize the danger to teams of firefighters living and working in the field. And we paddlers can certainly learn a thing or two from pros like James. Here's what he has to say:
Wildland firefighters frequently face lightning danger. Many, if not most, of the western states' wildfires are caused by lightning. In a pocket‑sized firefighter informational guide — the Incident Response Pocket Guide [PDF] — there is a page on thunderstorm safety. Here's an excerpt:
Approaching thunderstorms may be noted by a sudden reverse in wind direction, a noticeable rise in wind speed, and a sharp drop in temperature. Rain, hail, and lightning occur only in the mature stage of a thunderstorm.
The publication refers to the "30/30 rule," saying:
If you see lightning and hear the thunderclaps follow in less than 30 seconds, take … precautions…. Do not resume work in exposed areas until 30 minutes after storm activity has passed.
That thirty seconds between lightning and thunder calculates to about six miles away. Some "hazard control" items from the Guide that bear repeating are:
- If outdoors, find a low spot away from tall trees, wire fences, utility lines and other elevated conductive objects.
- If in the woods, move to an area with shorter trees.
- If only isolated trees are nearby, keep your distance twice the tree height.
- If in open country, crouch low with feet together, minimizing contact with the ground. You can use a pack to sit on, but never lay on the ground.
- If you feel your skin tingle or your hair stand on end, immediately crouch low to the ground. Make yourself the smallest possible target and minimize your contact with the ground.
- Don't group together.
- Don't stay on ridgetops, wide open areas, or near ledges or rock outcroppings.
- Don't operate landline phones, machinery, or electric motors.
- Don't handle flammable materials in open containers, or metal handtools.
I'm sure you'll agree that this is a first‑rate summary, and I'm in James' debt for bringing it to my attention. Note, however, that the Forest Service's "30/30 rule" is less conservative than the National Weather Service guidelines, which would get most boaters off the water while a storm was still 10 miles away, rather than six. Of course, Forest Service firefighters have a difficult job to do, and in doing that job they must sometimes accept a higher level of risk than recreational boaters. That's what it means to be a professional.
The Forest Service certainly isn't careless with its workers lives, though, and James goes on to describe the measures taken to protect firefighters in the field. These include having on‑site meteorologists to monitor local weather and issue alerts when conditions make an already dangerous job even more dangerous. When all is said and done, however, there are no guarantees, and James ends his letter with this somber reflection:
Even with all the precautions, … you are never completely safe outdoors in a thunderstorm.
A sound if sobering conclusion, and one well worth remembering. Canoeists and kayakers also need to understand that …
Lightning, Wind, and Waves Aren't the Only Hazards
As reader Norm Yarger points out:
I agree with the idea of getting off the water ASAP at the first sight of lightning or sound of thunder and waiting for 30 minutes after the last strike. This last spring I was the race director for a foot race that ran on a path next to the Rock River in Rockford, Illinois. There was lightning in the area, and when there was a strike with less than 30 minutes until the start, I cancelled the event. After all, running in the open is similar to boating on the water, and we were going to be very near the water, as well. The runners were glad I did cancel the event, as shortly after the time for the start, it began to hail with moderate‑size (read that as "it would have really hurt") "rocks from heaven." That's another hazard of a thunderstorm, and even a whitewater helmet won't protect the rest of your body.
Norm's right, and I'm a little chagrined that I didn't mention hail in my earlier article. I have vivid memories of being caught out in the middle of an open field by a storm while surveying a pipeline route — and of suffering a painful pummeling from hailstones the size of robin's eggs in consequence, despite my wearing heavy canvas overalls and an aluminum hard hat. One of the hailstones hit my watch hard enough to crack the crystal. I wouldn't have wanted to weather that storm in a kayak or pack canoe.
That said, I'd rather be struck by hail than lightning — better bruised than burned! Even better to seek shelter ashore, however. Wouldn't you agree?
Thunderstorms aren't exactly rare in Canoe Country. Which is why I wrote about them last month, in "Thunder? I Wonder…." But when my in‑tray subsequently filled up with e‑mail around the column, I decided to take another look at the subject, and as before, I've had more than a little help from readers. The take‑away message hasn't changed, however. It's still best to get off the water at the first clap of thunder. Yet it's important to read all the fine print on nature's warning label, too. I hope you've found the exercise as instructive as I have.
Related Articles From the Archives and Elsewhere
- "Thunder? I Wonder… More Thoughts on Seeking Shelter From the Storm"
- "Lightning is Frightening!"
- "Weathering Roaring Wind and Rain"
- "Beyond First Aid: Backcountry Medical Emergencies"
- "Lightning Safety" [NWS (US)]
- Lightning‑Associated Deaths — United States, 1980–1995 [CDC (US)]
- Struck by Lightning [External website]
- Lightning and Sailboats" [University of Florida]
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