Why did the snow in a popular ski resort in the south of Spain turn a strange shade of brown?

Granada province's Sierra Nevada mountains in the Andalucía region of southern Spain welcomed in the dawn on Friday stained an unusual shade of brown.

The much talked about 'calima' - dust from the Sahara desert in suspension - that has shrouded many parts of the region since Thursday, coloured the ski resort's slopes a strange hue, which until then had presented a striking white image after the heavy snowfall a few days ago

The formation of a 'Dana' (high level depression) in the Gulf of Cadiz area reached its peak on Thursday and Friday, bring the Saharan sand and, in the process, blanketing many areas in the south of Spain with a fine dust. In areas where there were showers it fell it as 'muddy' red rain.

The situation was quite similar to what happened two years ago, when a 'Dana' associated with another storm in the Gulf of Cadiz and a drought situation in Morocco favoured the entry of sand dust from the Sahara, which submerged many parts of the south of Spain in an orange haze which gave the appearance of 'Martian' skies.