WeatherBlog 15 2020/21 | Sahara greetings

The desert air is not only warm, but also dusty again. Depending on the region, the sky appears more or less milky and slightly yellowish. Sometimes the dust also promotes cloud formation, as the dust particles can act as condensation nuclei, especially in higher layers of air. However, at least in the WeatherBlog's current line of sight, there are currently no corresponding clouds. The dust hangs in a relatively well-defined layer, from which some of the higher peaks also protrude. The last time there was Sahara dust in the Alps was about three weeks ago. We remember the brownish snow, which can still be seen quite well in many snow profiles even now.

Whether and how the dust layers affect the avalanche situation is a recurring theme. There is nothing to suggest that dust as such plays a essential role. However, as the desert dust is always brought in during southerly exposures, the dust layer in the snowpack is often at or near melting crusts - the dust eventually comes with the heat. Edged weak layers can form around such crusts or layer boundaries. This sometimes gives the impression that avalanches occur "on the dust".