Lightning Safety Awareness Week
2014-06-22 19:36:07.000 – Ryan Knapp, Weather Observer/Meteorologist
The ‘Lightning Position’ demo.
This week (June 22-28) is known in the weather community as Lightning Safety Awareness Week. Friday, I started this discussion with the two big things to do prior to a thunderstorm – know before you go and when thunder roars, go indoors. These are best-case scenarios however, if you are days out in the backcountry, these two options may not be readily available. So what are some options you can do to reduce your risk of injury or death?
Time your activity to avoid potential storms. If the area you are hiking in is prone to afternoon thunderstorms, stick close to your grounded shelter or get to the next grounded shelter prior to storms hitting the exposed terrain you might be hiking on.
Choose safer terrain to be on. Avoid peaks, ridges and significantly higher ground around you. If you have to descend, do so as quickly (and safely) on the side that has no clouds over it. Get to the low points of rolling hills. Avoid wide-open areas of 100 meters or more where you become the highest point. While studies have shown that neither wet nor dry ground is considered more dangerous, you should avoid standing in standing water (puddles) or streams as these can be conductors.
While dry snow can be an insulator, wet snow can be a conductor. While some say being on dry snow is safer than being on bare ground, if you can’t tell the difference it is best not to be on snow at all.
Avoid cave entrances and small overhangs, which can allow arcs to cross the gap. If a cave is your only shelter, get as deep into it as possible and get to dry ground within the cave and assume the lightning position (see below).
Avoid trees and tall rocks, as they are lightning rods and attract lightning strikes. If you must move through a forest to get to shelter or get to a safer location, avoid tree trunks. Most studies show that a 50 meter cone of protection from trees trunks is the distance you want to aim for.
Avoid long conductors like metal fences, power lines, railways, bridges, or other metal objects. Tents should be avoided not only for the metal they contain but because they can actually become a high point in some areas.
Lastly, when you have reached the safest point around you, assume the lightning position, which will reduce the chances of a lightning strike (however, it offers no guarantees). Before getting into this position, separate yourself from anyone else you might be hiking with. Use the cone of protection of 50 meters apart or greater. Lay a sleeping pad, sleeping bag or a bag full of clothes on the ground. Your backpack, ice axe, crampons, tents poles, hiking pole, jewelry, belt buckles or anything other metallic materials should be away from you at a distance of 50 meters or more. Return to the insulator you put out earlier and squat on it trying to stay on your toes as much as possible while keeping your feet as close together as possible. Avoid sitting and DO NOT lay down. Once squatted, wrap your hands around your knees in a ball-like position. Lastly, close your eyes. Since a picture can be worth 1000 words, the thumbnail to this comment can be clicked for an example.
For additional resources on Lightning Safety, please check out the links below:
NWS Lightning Safety Home Page
MWO Lightning Safety Page
CDC Lightning Safety Page
Ryan Knapp, Weather Observer/Meteorologist