A very stormy February 2020 in the North Atlantic

During the first two weeks of February 2020, and more generally, since the beginning of the meteorological winter, the large scale atmospheric context in the North Atlantic and Europe, but also over the whole Northern Hemisphere is characterized by intense low-pressure circulation from the west and south-west , associated with high wind and rain.

This configuration is related to the permanent presence of intense lows in the North Atlantic and  polar regions, contrasting with, high pressures above normal in between Açores and southern Europe. This high/low pressure dipole  generates very positive NAO  (North Atlantic Oscillation) and AO (Arctic Oscillation)  indexes as illustrated  in the map below:

On the 10th of February, the AO index indeed reach a record level since 1950 , according to NOAA  (the pressure difference between low polar and high subtropical pressure is 6 time higher than the climate mean) . In  practice this translate into very intense lows in the North Atlantic and  westerly winds on the mid latitudes of the Northern hemisphere, including Europe.

Since the 8 february, the North Atlantic has indeed been the subject of an impressive storm activity including Storms Ciara (9-11 Feb), Ines (12-13) and Dennis (14-16 feb). The wind structure of these successive storms have been succesffully and jointly observed by SMOS and SMAP: