Lightning and Lake Tahoe
Lake Tahoe can have some crazy weather! It has snowed on the Fourth of July before, no joke. This kind of relatively unpredictable behavior can also make hiking in the mountains dangerous. You should always have a good sense of lightning safety before hiking in the mountains surrounding Lake Tahoe.
Most electrical storms happen in the spring in Lake Tahoe but are possible any time of year. The map at right shows one of the most active electrical days in the Sierras, and this was in February.
Lightning strikes are certainly more common in mountainous environments. This has to do with the way the terrain influences convective weather and the lack of appropriate lightning shelter in the mountains. Lake Tahoe is no different.
It’s true that the number of lightning-related fatalities in the U.S. has declined over recent years, but that doesn’t mean you’re safe. The decrease in fatalities is largely attributed to education. 432 Americans died from strikes in 1943, and by 2017 only 16 people were killed. Of those, just a small amount of victims are from direct strikes. From that statistic we see that most danger comes from indirect strikes, current hitting a victim through the ground. Only ten percent of lightning strike victims die as a result of the strike. According to the NOAA, your odds of being hit in your lifetime are 1 in 15,300.
There are a lot of “lightning facts” that can lead you into a false sense of security. One of which being, if the time between thunder and lightning is less than 30 seconds, you’re in danger of being hit. The truth is, you could be hit by lightning without any warning like that.
Wait thirty minutes after the last thunder clap before leaving shelter. Most strikes occur before rain and after the storm has passed. Again, lightning is possible any time when the conditions are right.
Insulating yourself from the ground will keep you safe. This is a last-ditch move to protect yourself and will be detailed below. But it won’t guarantee your safety.
Victims remain charged after a strike. This is also not true and is a reason why many responders are reluctant to start CPR. You will not be shocked by treating a lightning strike victim.
Count the number of seconds between thunder and lightning, divide by five, and that’s the distance to the storm in miles. Again, the next strike could happen at your location even if you calculate it to be five miles away using this rule.
Check the Weather
Weather forecasters have become pretty good at predicting lightning. It’s a good idea, no matter what, to check the weather forecast for the Lake Tahoe area before hiking. A chance of lightning shouldn’t have to keep you indoors, but you should at least have a plan for the risk.
No mention of lightning in the forecast doesn’t necessarily mean you’re safe.
Feel the weather
Lightning storms in Lake Tahoe are usually signaled by changes in the weather. Tall, rising clouds over mountain peaks and ridges are one sign of a possible electrical storm. A sudden, drastic change in winds and temperature is also a telltale sign.
Where to camp
Avoid pitching your tent directly under the tallest objects like large, tall trees, cliffs, and tall boulders. Lightning can hit these and spread along the ground. Avoid being directly in the open on mountaintops too; I don’t know why you’d do this anyways but it’s more dangerous in an electrical storm. Likewise, you shouldn’t be pitching a tent right next to a lake anyways, but this can be a dangerous spot during a lightning storm.
Established sites below the treeline and near lakes are likely already safe, and you’ll find plenty of these in the Lake Tahoe area.
What to do when you hear thunder
If you hear thunder you’re already at risk.
- Get to low ground as soon as possible. Lightning tends to take the shortest path to ground – if you can get below taller objects like mountaintops, your chances of getting hit decrease.
- Spread out. Spreading out to a distance of about 100 feet between people guarantees that if lightning does strike, at least one of you will be able to treat the other and get help.
- Drop all metal objects. Turn off your phones and ditch your hiking poles & framed backpacks. Leave them at least 100′ away from you.
- Avoid water and any low spots where rains will accumulate.
Is the hair on the back of your neck standing up? You’re in immediate danger. Immediately drop all objects, spread out, and seek low ground.
Above the treeline
There aren’t a lot of shelter options if you’re in an electrical storm above the treeline. This is why you should get to low ground as soon as possible at the first sign of a storm.
- Avoid caves and other openings in boulders. These areas can concentrate electricity if struck and you’ll be right in the middle of it.
- Don’t seek that one tree. Sometimes there’s that one lone tree that has defied evolution and managed to survive above the rest of the trees. This is a lightning rod. Stay away from it.
- Avoid being directly below high points. You should seek low ground, but this doesn’t mean to go to the base of a cliff. The electrical current will run down those high points and spread out on the ground below it, as far as 60 feet.
- Crouch and pray. Sitting on a non-conductive material like a Thermarest pad, heavy clothing, or dry ropes will reduce the chance of being electrocuted by stray current but not eliminate it. Sit with your knees in the air and your feet close to your butt. Make yourself a small, low target.
Below the treeline
You have more shelter options if you’re below the treeline, and likely below higher terrain that’s more at risk of being struck. Still, the chance of a strike is there.
- Avoid lone trees and the tallest trees. Just like being above the treeline, the one lone tree or the tall stand of trees in the middle of a shorter forest will have higher chances of being hit.
- Crouch in shorter shrubs or trees. Find the shortest group of trees or shrubs away from taller trees. These, in theory, shouldn’t get as much attention from lightning as the taller trees.
- If the storm is really close and you have some insulating material to sit on, do that, just as you would above the treeline.
If lightning strikes
Your hike is over if lightning strikes near you. Evacuate back to your car and report to the emergency room if there are any signs or symptoms, which could include:
- hearing loss
- period of unconsciousness
- skin burns
- trouble breathing
- decreased mental state
- impaired vision
Critical injuries will often result in cardiac arrest. Perform CPR and request Search & Rescue by the most expedient means possible.