World of Science | Snow Observations (SnObs)

An accurate and, above all, useful assessment and description of the current avalanche situation can always present avalanche forecasters with a major challenge. In addition to an increasingly dense network of weather stations and constantly improving weather and snowpack models, current observations directly from the terrain are an important basis for the work of avalanche warning services. As the avalanche risk can vary greatly, even on a small scale, due to different factors such as precipitation distribution or complex topography (altitude, exposure, terrain), as much feedback as possible helps forecasters to gain a more accurate picture of the avalanche situation. This is exactly where SnObs comes in!

Important information for avalanche warnings

When mountain sports enthusiasts are planning a ski tour or want to venture off the secured pistes in winter, they need to be able to rely on the most detailed information possible about the local snow and avalanche situation when planning their tour. This always raises the question:  What is the probability of an avalanche being triggered in this area?

This is precisely the question that the forecasters at the avalanche warning services ask themselves and try to answer every day. To get a detailed picture of the current situation, they rely on as much information as possible directly from the terrain.

The observations and their recording with SnObs

SnObs was introduced to make this work even more efficient and to be able to digest even more feedback from the public in an organised manner. SnObs stands for "Snow Observations" and is a platform on which ski tourers, freeriders and all those who are out and about in the mountains in winter can report observations from the terrain directly to the avalanche warning service.

It is important to note that SnObs is not a classic ski touring platform. It is not about describing ski tours, off-piste descents or their snow quality, but rather about sharing personal perceptions of the snow and avalanche situation. Another difference to other avalanche apps such as SnowSafe is that SnObs allows all users to view the reports from the terrain, whereas SnowSafe only forwards them to the avalanche warning services.

Since the 2024/25 season, SnObs has offered three different features for this purpose: The "Simple observation", the "Avalanche event" and the "Snow cover test".

Under the category of "Simple observation", feedback is provided via a text field and/or using predefined subcategories such as hazard signs or special grain shapes on the snow surface. The frequent inability to record observations of these phenomena using weather station data and weather models makes this individual feedback extremely valuable. They are also useful for forecasters. In addition, they are of great importance with regard to future snowfall (e.g. surface frost as a potential weak layer of tomorrow).

The "Avalanche event" can be used to record information on the type and size of avalanche, the extent of damage and the (approximate) time of departure.

The "Snow cover test" can be used to transmit snow cover tests carried out in the field (extended column test, sliding block and small block test).

SnObs can also be used in offline mode thanks to automated data transfer with a sufficient internet connection. In addition to your own entries, it is also possible to view the observations of other users in this app. Communication is therefore not only unidirectional, but also bi- or multidirectional and offers interested winter sports enthusiasts lots of important first-hand information on the current (hazard) situation.

Meaningful feedback in SnObs and its use

A good observation consists of meaningful images, which should be included with every report in SnObs, and a detailed description of the local conditions in text form. It is also important that the GPS point of the observation is checked and adjusted if necessary. This is the only way to reliably locate observations. In addition, care must be taken to tick the checkboxes mentioned (surface frost, sleet, wild snow, ice lamella) if one of the boxes applies to the observation. This is the only way the forecasters can filter feedback according to the required criteria.

The individual pieces of information from the terrain now reach the warning services from the various sources, where they are used to compile the avalanche report and other products.

Every feedback counts

Enthusiastic winter sports enthusiasts who are already out on skis in autumn and in bad weather can provide crucial observations for avalanche warnings. This is because the avalanche warning services sometimes receive very little feedback from the terrain, especially in the off-season (i.e. in early winter and late spring), but also in high winter when the weather is bad. But all other feedback is also important: an observation is always localised information - the avalanche forecast, however, is an area-wide product. The more localised information the avalanche warning service receives, the better an area-wide hazard analysis can be created from these observations.

In the 2023/24 season, a total of 233 people actively used the SnObs platform to share their observations. This resulted in 531 entries, consisting of 318 simple observations and 213 documented avalanche events.

The Bavarian Avalanche Warning Service joins in

From the 2024/25 winter season, the Bavarian Avalanche Warning Service will also actively use the feedback from SnOBS. Christoph Hummel explains why they have decided to do this: "In addition to the additional information that we avalanche forecasters will receive from the community through SnObs for the daily avalanche situation report, I see the added value for each individual winter sports enthusiast themselves: anyone who registers will see all the entries made by others. Anyone can call up point information on snowpack stability and share their own local findings with others. SnObs creates a community that is not about profiling, but purely about sharing safety-relevant information." Hummel emphasises: "Of course, the quality of the information is important. If you share a snow cover test result, you have to make sure that you have carried out the snow cover test correctly. The best way to learn how to do this is on courses run by mountain schools and alpine clubs."

Join in and make your contribution to avalanche warning!

Since the 2023/24 winter season, anyone can register at www.snobs.live and send current observations from the terrain directly to the respective avalanche warning service.

You can find the link to register at www.snobs.live

The application works in the current Internet browsers Google Chrome, Firefox or Safari and can be used on mobile devices as well as on desktop computers. To enable offline use on mobile devices, proceed as follows:

iOS: www.snobs.live in Safari. Select the Share icon and select Add to Home Screen.

Android: Open www.snobs.live in the browser. Open the menu (three dots in the lower/upper right corner of the browser) and select 'Add to home screen' (Chrome) or 'Add page' (Firefox)

The bookmark now appears as an icon on your home screen and can be opened like an app.

This article was co-written by Marco Knoflach and Johanna Sparber. For technical reasons, only one author is currently listed on the website.