Planetary Upper-level Frontal Zone in the Euro-Atlantic Sector in Summer in 1990–2019

The analysis of monthly mean locations of the planetary upper-level frontal zone in the Euro-Atlantic sector in summer during 1990–2019 is presented. Specific positions for the summer months (June, July, and August) are noted, and maximum northward displacements from the climatological normal for 1961–1990 are found in the years with the formation of the atmospheric blocking. The values of standard deviations of the displacements relative to the normal position were calculated for the summer period of each year both for the North Atlantic, Europe, and the European part of Russia and for the Euro-Atlantic sector. On the basis of linear regression, a tendency is revealed toward an increase in the meridional displacements of the planetary upper-level frontal zone over the recent thirty years and toward the occurrence of maximum deviations over the last decade.