On 29 November 2016 the VIIRS instrument on Suomi-NPP covered the Alps in two consecutive day orbits. This does not happen very often.
29, October 2020
By HansPeter Roesli (Switzerland)
By coincidence, at the same time as the passes of the polar-orbiting Suomi-NPP satellite, the weather was also rather unusual — low clouds were covering extended parts of the sub-alpine areas on both sides of the Alps.
On the north side air did not penetrate very much into the Alpine valleys, while on the south side low cloud invaded all the valleys west of the Lake of Garda. So VIIRS could only 'see' the highest snow-covered peaks — the areas in cyan.
As can be seen from the two images, taken 97 minutes apart (Figure 1), the cloud cover did not last very long. Dissolution was already in progress.
Previous case studies
Heavy snow in parts of Spain
Parts of central Spain saw their heaviest snowfalls in decades in January 2021.
Early summer convection in central Argentina and Uruguay
Severe convection in central Argentina in December 2020.
Nearly-record snowfall in the western Alps in December 2020
Winter 2020 started with more than 2 m snow in the Alps and an extreme amount of rain.