Between January 7–9, 2021, a moist, low-pressure weather system over the ocean collided with a cold air mass sitting over western Europe. The result was the heaviest snowfall over Spain in fifty years.
After barely seeing significant snowfall for a decade, the capital city of Madrid was blanketed with widespread accumulations of 20 to 30 centimeters (8 to 12 inches). Some suburban and rural areas in central, northern, and eastern Spain were coated with up to 50 centimeters (20 inches) of snow. The country’s State Meteorological Agency (AEMET) declared it the largest snowfall in the region since 1971. In southern parts of the country, torrential rains led to flash floods.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired a false-color image of snow cover in Spain and southwestern France in the early afternoon on January 11, 2021. This false-color image combines visible light, near-infrared, and shortwave infrared (MODIS bands 7-2-1) to distinguish clouds (white) from snow, ice, and high-altitude icy clouds (all shades of teal). Vegetation appears bright green.
Nearly 700 streets and highways were rendered impassable by the snowstorm, and hundreds of people were stranded in cars for a night. All flights out of Madrid were canceled for nearly two days, as was most rail traffic. Government workers and soldiers were dispatched to clear roads in order to keep food supplies and COVID-19 vaccine supplies moving. Forecasters expected cold temperatures (-8 to -10 degrees Celsius) to linger until January 14, freezing some of the snow into ice.