
Heavy snow in parts of Spain
8 January 2021 09:00 UTC-11 January 13:00 UTC


Parts of central Spain saw their heaviest snowfalls in decades in January 2021.
10 June 2022
12 January 2021
By Natasa Strelec Mahovic, Jochen Karl Kerkmann and José Prieto (EUMETSAT), Ivan Smiljanic (CGI) and Zsofia Kocsis (Hungarian Meteorological Service)
The snow was caused by Storm Filomena, which brought 30-40cm on snow (about 50mm of equivalent liquid water) to Madrid. This was the most snowfall in the area since 1971, although well behind a snowfall event in November 1904, when double in amount of snow was recorded. Filomena was also similar in precipitation to other such events in February 1907, February 1963 and March 1971.
On the morning of 11 January, as the clouds cleared, snow covering most of central Spain could be seen in satellite imagery (Figure 1). In the Snow RGB the orange-red colour representing snow is quite strong, meaning that the ground was covered by a thick layer of snow (more than 10cm). In the Natural Colour RGB the snow covered areas appear as cyan, similar to the colour of ice clouds, so in this RGB snow cannot be so clearly distinguished from the ice clouds.
Meteosat-11 Natural Colour RGB and Snow RGB comparison


Figure 1: Meteosat-11 Natural Colour RGB and Snow RGB image, 11 January 09:00 UTC, reveals the extent of the snow cover in Spain after the clouds cleared. Snow (and ice clouds) in cyan in the Natural Colour RGB, i.e. red and orange shades in the Snow RGB.
NOAA-20 VIIRS Cloud Phase RGB and Cloud Type RGB comparison


Figure 2: NOAA-20 VIIRS Cloud Type RGB and Cloud Phase RGB, 11 January 12:05 UTC, showing the snow cover from the polar satellites. Snow in green to yellow, i.e. blue shades.