In the Alps, strong thunderstorms are one of the greatest dangers on the mountain in the summer months. What should you do if you are surprised by thunder and lightning on the mountain? You should know these five rules of conduct.

Mudslides and heavy rain devastate entire areas of Central Europe, a tornado sweeps across the southern Czech Republic, in Canada temperatures reach almost 50 ° C. Climate change makes extreme weather phenomena more and more likely. In the Alps, strong thunderstorms are one of the greatest dangers on the mountain in the summer months. In addition to cold and wet conditions and the associated risks of hypothermia and the risk of slipping, the weather phenomenon also brings with it an acute risk of lightning strikes.

Crouching position with closed legs on an insulating surface. Keep your distance from watercourses and free-standing elevations such as masts or trees. (Graphic: Georg Sojer / Alpenverein)

The good news: The chance of being surprised by a thunderstorm can largely be prevented with good tour planning and careful observation of the cloud formation on the day of the tour. An early start is a clear advantage, especially in summer.

Before every mountain tour, you should get information about the daily thunderstorm rate as soon as possible with a high-quality weather report.

Michael Larcher - Head of the Mountain Sports Department at the ÖAV

If there is a good weather report, the tour must be planned in such a way that you are back at the safe starting point or in a refuge in good time - ideally at noon. On unstable days, long tours and those with rope insurance on exposed ridges and with exposed peaks should be avoided.

In rock niches we keep enough distance from the rock. (Graphic: Georg Sojer / Alpenverein)

Pay attention to weather developments and alarm signals

Careful tour planning that is adapted to the conditions and precise observation of the cloud formation on the day of the tour are essential.

A prognosis is only ever a probability that thunderstorms will approach earlier than originally assumed.

Michael Larcher - Head of the Mountain Sports Department at the ÖAV

It is always worthwhile to closely observe the development of the last few days and especially the weather development during the tour. If cumulus clouds have formed earlier from day to day and if there are cluster clouds in the morning hours on the day of the tour, thunderstorms must be expected in the early afternoon.

On rock faces, we are safe from lightning strikes, but it is important to be aware of the risk of falling rocks. (Graphic: Georg Sojer / Alpenverein)

Acute and clear alarm signs for an approaching thunderstorm are tower-like and anvil-shaped storm clouds, gusty, refreshing wind and electrical charges (whirring) in the air.

A rule of thumb:
The approximate distance to a thunderstorm in kilometers can be calculated by dividing the number of seconds between lightning and thunder by three. Example: If the time span between lightning and thunder is ten seconds, the center of the thunderstorm is only around three kilometers away. High time to take appropriate protective measures!

What to do when a thunderstorm threatens the mountain?

However, if a thunderstorm on the mountain should surprise us, we can improve our situation with the help of simple but effective rules of conduct. Five tips in the event of a thunderstorm:

  1. We leave exposed ridges and solitary elevations such as summit crosses and rock towers as quickly as possible.
  2. We move away from steel ropes and - if possible - go to larger rock caves for protection, but stay away from the rock face as much as possible, at least 1,5 m.
  3. Crouching on the rucksack or rope to avoid a possible step tension, we wait for the thunderstorm to pass.
  4. In terrain at risk of falling, e.g. B. on the via ferrata, we always stay secure!
  5. We can protect ourselves against moisture and coldness with a bivouac sack and functional clothing.

Thunderstorms are often associated with heavy rain. In a short time, dangerous torrents can develop in rock faces and trigger rockfalls. In the case of heavy rain there is also the risk of getting soaked quickly and cooling down a lot. The greatest danger in heavy rain is the complete soaking and the resulting hypothermia. In alpine climbing routes and on via ferratas we cannot evade quickly and at will, which further exacerbates the situation.

If you can find a dry place, it is usually better to sit out the thunderstorm there than to climb hectically towards the exit and then be without protection.

Michael Larcher - Head of the Mountain Sports Department at the ÖAV

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