Vortex split of 2018 (IMAGE) University of Bristol Caption The stratospheric potential vorticity field on 10th February 2018. The Stratospheric Polar Vortex is about to split in two, and the weakening of the vortex was followed around two weeks later by a severe cold air outbreak over Europe known as the Beast from the East. Data from ERA-Interim reanalysis (Dee et al., 2011). Credit University of Bristol Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.