VIIRS double view of snowy Alps
29 November 2016 11:16 UTC and 12:53 UTC
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
Extremely warm and dry December in the Alps (20 Dec 2015)
Full-moon scene over the alpine region and Italy (6 Jan 2015)
Sea-breeze and cloud streets in the Po Valley (11 April 2014)
