
The scene of the crime: a view of South Arapahoe Peak from just below the saddle shared with Mount Baldy.
It was early June 2006, and we thought the conditions were good enough for another traverse of the Arapahoe Peaks, but we didn’t get the chance to find out when the weather took a shocking turn for the worse. We should have been more careful.
Lightning is one of the oldest observed natural phenomena on earth. Once generally feared as a weapon of the gods or God, scientists now tell us lightning is just a gigantic spark of static electricity. People once avoided lightning above all threats to life due to the heavenly implications of being a target. Now we are too casual about the low odds of a strike.

The scene of the crime: a view of South Arapahoe Peak from just below the saddle shared with Mount Baldy.
It was early June 2006, and we thought the conditions were good enough for another traverse of the Arapahoe Peaks, but we didn’t get the chance to find out when the weather took a shocking turn for the worse. We should have been more careful.
Lightning is one of the oldest observed natural phenomena on earth. Once generally feared as a weapon of the gods or God, scientists now tell us lightning is just a gigantic spark of static electricity. People once avoided lightning above all threats to life due to the heavenly implications of being a target. Now we are too casual about the low odds of a strike.
It was the late spring season, and that meant the conditions were highly variable. We considered doing the SkyWalker Couloir, but thought the weather might be too warm for a safe ascent. We resolved to take the easy way up the South Arapahoe Peak and then traverse to the North summit to make an interesting day of it. What we didn’t think about was the possibility of lightning, but that is what we got.
We got our interesting day.
Lightning starts with clouds. The sun heats up the spinning earth in an irregular fashion which results in wind. Air rises when it is warmer than the air above it or is pushed up by winds passing over mountains. When the air & water vapor mixture rises, it can cool enough to turn water vapor into water droplets (or ice crystals) which becomes visible as clouds.
We started up just before first light from the 4th of July trailhead and quickly made our way up the familiar trail. We turned up the trail to the saddle between South Arapahoe and Baldy, pausing only long enough to longingly examine the Sky Walker route. We assured each other that we’d come back another day to do it.
As we made our way up the south ridge below the summit, we could see fast moving storm clouds north and east of us. But it was very early in the day and cold, and nothing was coming from the west. We didn’t see any risk to us.
Thunderstorms are a special type of cloud that occur when warm, moist air rises high into the atmosphere, reaching to the freezing temperatures at very high altitudes. The rising warm air and sinking cool air push around the ice crystal and heavier chunks of ice, which bang into each other creating static electricity. The lighter-weight, positively charged ice crystals are blown to the top of the cloud while the heavier, negatively charged clumps of ice cluster at the bottom of the cloud. The opposite charges attract each other, and the lightning we see in the clouds is them finding each other.
Once on the summit, we started to notice lightning in those storm clouds. And then we saw something unusual: those clouds off to the east seemed to be nearer to us than before. Where they flowing east-to-west? We didn’t know what to make of it. We wondered aloud to each other concerns about possible risk.
We were tempted to continue since we had come so far and were close to our goal; but our mountaineering ambition had dulled enough over the years to allow for reason to prevail. We decided to bail. While we didn’t understand what was happening, we were smart enough to realize that starting a technical traverse in such conditions would be foolish.
Lightning hitting the ground makes for all the excitement. The negatively charged cloud bottom causes electrons in the ground five thousand feet below to flee (like charges repel each other), resulting in an electric field that we can hear, feel and smell. The electric field is strongest on ground-connected objects whose tops are closest to the base of the thundercloud. If the electric field is strong enough, a conductive discharge (called an upward lightning streamer) can develop from these points and the surrounding air component atoms become separated into positive ions and electrons — the air becomes ionized. This ionized air (also known as plasma) is much more conductive allowing for electric current to flow from the cloud to the positively charged streamer or ground that is seeking electrons. We see this as lightning.
But we still didn’t see any immediate risk, so we didn’t take immediate action. We took a break on the South Arapahoe summit to enjoy more of the day before starting back down the trail at a moderate pace.
Familiarity breeds contempt. While the rarity of lightning incidents makes it easy to become complacent, sometimes lightning doesn’t miss. Being hit by lightning is a serious event comparable to a bear or lion attack, resulting in death and life altering injuries. See NOAA’s Medical Aspects of Lightning for more information
I kept looking over my shoulder as I worked my way down the ridge. I could see the storm was getting closer much faster than expected. We were losing the race. I told Brian we needed to go faster.
Then the thunder started to boom.
Once we hear the thunder or feel the cold wind or the sting of crashing hail, the thunderstorm is upon us. Our chance to be safe is lost. We are limited to looking for ways to reduce the risk that we can no longer avoid. And, reacting to lightning once caught out is an uncertain art.
Properly motivated, we started moving as fast as we could as the thunder became louder and louder. And then it was right on top of us. Boom, Boom, BOOM!
The flash-bang separation was very short, one second or less.
When we reached the saddle and good ground, we started running to get to the descent trail that would get us off the exposed ridge.
About 1/2 way across the saddle, it happened.
An explosion went off as I felt a sharp, stinging shock hit the top of my head. Stunned by the noise and the sense that I had been hit by lightning, I stopped running. I didn’t know what to think. I wondered if I was dead.
I turned around to see if Brian would have a look of horror on his face. He merely hollered, “Run!”
I paused for an instant to ponder the problem of my metal hiking poles sticking out of my pack, but seeing Brian disappear down the mountain, I decided to just run like scared cat. I caught Brian in an instant and we flew down 1000 feet in about 10 seconds (felt like); and then the storm was gone.
Once we see or decide that the weather environment is unsafe, our goal for the day must change immediately and permanently to getting to a “safe” shelter. In the high peaks, that almost always means getting to the vehicle, and the path to safety will often force us to traverse dangerous ground. Our goal of getting to safety will be achieved by using three strategies:
- Move quickly to the vehicle to minimize our exposure to the dangerous environment and
- Avoid high lightning risk spots on the trail to reduce exposure to risk and be able to stop and
- Become a small target with a single point of ground contact when a lightning strike is imminent.
Going as fast as possible to safety is the most important thing, but it isn’t enough. Avoiding high risk locations means to minimize the chance of injury while moving while allowing us to safely get small when necessary. Our ability to make fast, correct decisions in juggling these strategies is the key to our continuing health. (See more info about dealing with Imminent Lighting Threats)
We slowed and then stopped to gather our wits and remove our rain gear. I asked Brian if he saw the lightning bolt hit me. He said ‘no’ and I couldn’t find any evidence of burns on my hat or head. But none of that mattered; in the instant I thought I’d been hit by lightning, I was sorry for my casual attitude that allowed me to accept such a risk. My life was changed forever.
I was hit by a low-power ‘upward lightning streamer‘
Upward lightning streamers that do not connect with the downward leader to complete a lightning channel are estimated to cause approximately 30% of lightning related injuries. High-current pulses are launched from the ground (often tall, pointy, isolated objects) near the lightning bolt as it initially approaches the ground. These “streamer currents” are much less powerful than the full lightning strike but can be strong enough to cause injury or death to humans. (more)
I felt lucky to be alive.
And I have dedicated myself to understanding lightning and staying safe in a lightning filled environment like the high peaks of Colorado. In the time since, I’ve identified for my own use five levels of lightning danger for Colorado high peaks: low danger, approaching danger, high danger, extreme danger, and imminent strike.
Below, each category is described with conditions that may be observable or audible, depending on the presence of terrain or wind noise obstructions:
For any of us High Peaks Adventurers, our rational reaction to these levels of danger depend on our willingness to assume lightning risk. The only way to be “safe” is to stay home. But if we insist on proceeding with our risky venture, we can break down the situation into four questions that must be answered; and because we are dealing with uncertainly about deadly risk, the answers will be different for each person:
- What risk level am I willing to assume? There is a continuum of reactions we each can take in the face of lightning danger. On the extreme conservative end, we could choose to never go outside when clouds are in the sky. On the extreme aggressive end, we could choose to never worry about lightning since it doesn’t seem to hit many people. The right strategy for most of us is between the two extremes. (more)
- How to plan to avoid lightning? There is no safe haven from lightning atop the high peaks; the only way to be safe is to avoid lightning all together. Either we stay home on a bad weather day or we start early enough that we can get less exposed before the lightning shows up. (more)
- How to read the sky for early warnings? Sometimes the lightning threatens to show up when we are vulnerable, despite our best efforts to avoid it. But we can only hear thunder 10 miles away or less. Since an air mass thunderstorm will travel over ground at 15-25 mph, we may have only 20-30 minutes before the storm is overhead (and the worst lightning risk begins). We need more lead-time; we need to be able to get an early, even if imperfect, indication of when to turn around. (more)
- How to reduce the risk when the chance to be safe is lost? If we accept some lightning risk, we should expect to eventually get caught away from safe shelter when the lightning arrives. Too often, the mountains obscure our view of the horizon and oncoming storms, and the wind noise keeps us from hearing thunder. When we’ve been caught in a vulnerable position, we need to know what to do reduce the likelihood of being hit or injured by a lightning strike. (more)
The chart below that I’ve created for my own use is based on the advice provided by experts for minimizing lightning risks; the ‘moderate’ level of risk is the only usable information for me. The high-risk option is merely behaviors I have observed and even used before I knew better. I include this level and the low-risk level to provide contrast.
But please do not take my word for it. Do your own research and make your own decisions; it is your life.
My sources:
(1) NOAA: The National Oceanic and Atmospheric Administration (www.noaa.gov). NOAA includes the National Weather Service (www.nws.noaa.gov), JetStream (http://www.srh.weather.gov/srh/jetstream/) and National Severe Storms Laboratory (http://www.nssl.noaa.gov/).
(2) NLSI: National Lightning Safety Institute is a non-profit, non-product advocacy of lightning safety for both people and structures, founded and run by Richard Kithil (http://www.lightningsafety.com/)
(3) Lightning Safety Group, American Meteorological Society Conference
(4) Mary Ann Cooper, MD, Associate Head of Academic Affairs, Professor, Departments of Emergency Medicine, Neurology and Bioengineering, University of Illinois at Chicago
(5) NOLS: National Outdoor Leadership School, Backcountry Lightning Safety Guidelines (www.nols.edu/resources/research/pdfs/lightningsafetyguideline.pdf)
To see more more details of what I found for myself, see the following: