Circulation conditions of the abnormally cold winter of 2005/06 over Siberia

Circulation conditions of the abnormally cold winter of 2005/06 in Eurasia, where the intensification of meridional flow was accompanied by frequent intrusions of cold air masses into midlatitudes and their subsidence in the lower troposphere, are studied. The development of deep upper-level cyclones over Siberia and the Urals was preceded by stratospheric warming and long-term blocking processes in the troposphere over Europe and Yakutia. Strong cyclonic wind shears and intensified jet streams were observed in the high-level convergence zone over Siberia. Generally the weakened westerly flow in the substantial atmosphere thickness, a reduced number of deep cyclones in the western Arctic sector, and stratospheric warming provide high predictability of short-term climate changes in Eurasia in the wintertime.