What to do when a storm hits in the mountains: awareness, precaution and other advice for hikers and mountain sports enthusiasts
Whether it’s to escape, to challenge oneself, or to meditate, and whether you’re walking, running, rolling or flying, the mountains are an limitless playground where one can fully experience a complete range of emotions. But behind the enchanting beauty of this lofty setting the mountains remain a wild, often isolated and sometimes hostile environment where nothing should be left to chance. The weather, and in particular thunderstorms and windstorms, are potential dangers that need to be considered when organizing and preparing for your forays into the mountains.
Find out how to anticipate and react to foul weather in the mountains with our tips and tricks for safe summer activities.
How to prepare for an outing in the mountains
Preparation and anticipation are the keys to staying as safe as possible on your trips into the mountains.In addition to the assessment of your skills and goals, the planning of your itinerary should also include bailout scenarios in case the weather deteriorates. So before you head out, make sure you know the distances between waypoints, the amount of altitude you’ll gain or descend, the environment and changes in terrain, signs and landmarks, water and refreshment points, bivouac possibilities, as well as alternative routes, fallback options and potential places to take shelter in case of a thunderstorm.
It's also essential to bring along whatever technical equipment you'll need to overcome the challenges of your route , as well as safety gear such as a backpack and first-aid kit. Once you've gathered all the gear, it’s time to deep dive the weather forecast and time your departure accordingly.
Learn more about: how to prepare for a hike or trek
Why weather in the mountains is so difficult to predict
Featuring both bulwarks and catalysts, mountain ranges have a major influence on the circulation of air currents which in turn can generate significant anomalies on a local level. As a result, mountain meteorology is a complex science. Forecasts can change drastically quite quickly, and our perception of the conditions can be misleading. Topography also contributes to the formation of updrafts and thunderstorm-generating clouds, while high peaks and summits attract lightning strikes. In fact, the risk of lightning strike is almost 50 times greater in the mountains than in valleys!
The specifics of topography and fluctuating conditions in mountainous areas mean that we have to always stay alert, and continually analyze weather patterns on several different levels.
Forecasting and analysis: how to find and interpret weather forecasts
Weather forecasts have to be analyzed on several geographical and chronological levels. To forecast the weather on a given day and in a given place, you need to look at weather conditions that have evolved over the previous days, first on a macro scale then on a local scale, and starting with the region then the mountain range and finally the specific area you’re interested in.This will result in a general trend that will give you an initial idea of how the weather is developing, and whether the area you’ll be in is under a stable high-pressure system or, on the contrary, a low-pressure system that is very unstable. In this case, you'll then need to keep a close eye on the hour-by-hour forecasts for that area.
There are loads of weather apps for tracking wind and rain forecasts in real time. These can sometimes be a little complex at first glance, so it's important to familiarize yourself with them as well as other forecasting tools you choose to use before setting off into the mountains.
Observation and decision-making: what to look for when you’re out and about
Beyond forecasts, observation and analysis of conditions in the field are essential. Always keep an eye out for changes in the weather. Weather indicators to watch for:
- Fast drop in temperature
- Sudden drop in atmospheric pressure on your barometric altimeter
- Rising winds and strong gusts
- Changing skies including the color and structure of clouds
Keeping an eye on the structure of clouds can provide a wealth of information and the formation of cumulonimbus clouds is a particular warning sign. These thunderstorm-inducing clouds are formed when two opposing air masses meet and are characterized by their anvil-like shape. They can spread over an area of three to nine miles (5 to 15 kilometers) and are accompanied by turbulence and violent conditions.If you see cumulonimbus clouds forming on the horizon, you'll need to analyze the situation accurately and make decisions accordingly. To estimate your distance from a thunderstorm, count the number of seconds between the sight of lightning and the sound of thunder. Sound takes about five seconds to travel one mile, or three seconds to travel one kilometer).
Reaction and behavior: what to do in the event of a storm?
Clearly, the best thing is to avoid finding yourself in a sketchy situation! But if you do get caught out by the weather in the mountains, here are some tips on how to protect yourself from the dangers of thunderstorms.
- Don’t panic
Panic and haste often lead to accidents so remain calm and alert at all times. While the risk of lightning strikes is the main danger, rockfalls, landslides, falling rocks and falling branches generally accompany thunderstorms, so keep your eyes open and proceed carefully.
- Avoid the peaks
Lightning seeks the easiest path to the ground and therefore it strikes first on peaks and summits. If you are on a summit when a thunderstorm hits, descend as far and as quickly as possible and stay away from high points (ridge lines, isolated trees, ski-lift pylons, etc.). Take advantage of gullies or depressions to descend.
- Avoid caves and overhangs
Like peaks and summits, caves and overhangs attract lightning. If you find yourself under an overhang do your best to find a flat, wide area beneath a face that’s ideally 5 to 10 times your height. Keep at least six feet (two meters) from the wall. If you’re in a cave, stay at least six feet (two meters) from the walls and entrance.
Only "Faraday cage" shelters – such as cars and structures with metal roofs – block electromagnetic fields and protect against lightning. So when you’re in the mountains, unless you can find a mountain hut or stock pen with a metal roof it's sometimes better to stay out in the storm than to seek shelter at all costs.
- Remove and distance yourself from metal objects
Hiking poles, crampons, quickdraws, carabiners, water bottles... Jos kuljetat mukanasi metalliesineitä, laske ne maahan ja siirry niistä vähintään 20 metrin päähän.If you have any metal objects with you, put them down and move at least 65 feet (20 meters) away.
- Put as much insulation as possible between you and the ground
Because lightning seeks the ground try to have as little contact with it as possible and tuck into a ball. Put both feet together on your backpack and crouch down until the storm passes. Don't stand or lie down. If you're in a group, move away from each other to avoid ground-return conduction between you.
- Proceed with caution
Once the lightning has passed, the danger is not completely over. You still have to get home! After the last thunderclap wait about 30 minutes before leaving the area. Take your time to observe and analyze the situation before choosing the best route back. After a thunderstorm, your progress will probably be limited by poor visibility, slippery terrain, impassable sections, torrents or mudslides...It might still take a while for you to get back!
Cold weather and the risk of hypothermia are not to be underestimated either. If you have any dry clothes in your bag, change quickly (we advise you to always have a change of clothes in a waterproof bag inside your pack). Remember to eat and drink to maintain energy and avoid the risk of dehydration. (To consume less energy, we recommend drinking hot or at room temperature).
If the terrain is impassable or the situation incongruent with safe progress (e.g., you’re injured, cold, lost, etc...), don't hesitate to call for a rescue and wait for their instructions. All thunderstorms are potentially dangerous, but in the alpine, isolation and technical terrain increase the danger. So before setting off into the mountains, anticipate the risk of thunderstorms and don't head into an exposed area if you have the slightest doubt about how the weather will evolve.
While you're on the trail, keep a close eye on the time and distance remaining, and remain cognizant of your energy level, your abilities and weather conditions so that you can continue your outing with enjoyment as your driving force rather than stress.
Learn more about: the benefits of hiking