In June 2016, a slow-moving weather system unleashed several days of heavy downpours on western Europe, pushing the Seine River to heights not seen in 34 years. With the Seine’s water levels 6.1 meters (20 feet) above normal in Paris, flood waters knocked out electricity for thousands of people, interrupted road and rail traffic, shut down schools, and caused an estimated 1 billion euros of damage. During the worst of the flooding, the world’s most visited museum, the Louvre, closed as employees scrambled to move artwork out of basement areas that were at risk of flooding.
The map above depicts satellite-based measurements of rainfall over western Europe from May 22 to June 6, as compiled by NASA. These rainfall totals are regional, remotely-sensed estimates, and local amounts can be significantly higher when measured from the ground. Much of the rain—more than 400 millimeters (16 inches) in some areas—fell in central France within the Seine’s drainage basin.
The data come from the Integrated Multi-Satellite Retrievals for GPM (IMERG), a product of the Global Precipitation Measurement mission. IMERG pulls together precipitation estimates from passive microwave and infrared sensors on several satellites, as well as monthly surface precipitation gauge data, to provide precipitation estimates between 60 degrees North and South latitude. The GPM satellite is the core of a rainfall observatory that includes measurements from NASA, the Japan Aerospace Exploration Agency, and five other national and international partners.
The rains were fueled by a blocking pattern in the jet stream. According to the Weather Channel, an area of low pressure remained nearly stationary for days, sustaining persistent downpours in the region.
NASA Earth Observatory map by Joshua Stevens, using IMERG data provided courtesy of the Global Precipitation Mission (GPM) Science Team's Precipitation Processing System (PPS). Caption by Adam Voiland.