Atmospheric analysis of the cold late February and early March 2018 over the UK

A strong blocking anticyclone developed over Scandinavia through the last week of February and persisted into early March 2018, driving a bitter easterly wind from Siberia and bringing a severe cold outbreak and significant snowfall to the UK. A second spell of severe weather and low temperatures then returned to the UK over 17-19 March. The severe weather was preceded by a split in the stratospheric polar vortex and the onset of a sudden stratospheric warming event. In turn, there was an equatorward shift in the tropospheric Atlantic jet, which set up an amplified Greenland ridge that stretched from central Russia, over Scandinavia to Iceland, and across the North Atlantic to Hudson Bay. Here, we revisit the severe cold outbreak that impacted the UK, discussing the sequence of events and synoptic setup, followed by a more in-depth examination of the contributing factors, including a sudden stratospheric warming event.