14-days Ensemble Forecast of the stratospheric polar vortex
The stratospheric polar vortex is visualized with polar maps of the Potential Vorticity (PV) on an isentropic surface. This surface is defined by a potential temperature of 485K, i.e. in the lower stratosphere where polar ozone depletion happens. The mosaic of maps below are derived from a subset of the Medium Range Ensemble Forecast started daily (at 00UT) by ECMWF. The forecasts are produced for the 14th day (since 2016/03/23, 9th and 15th day before). The primary intention is to allow a subjective evaluation of the probability of vortex splits during the polar Spring.