The influence of stratospheric processes on the troposphere is defined by a multifactorial mechanism containing various geophysical and photochemical processes. This interaction determines the weather and climate of a particular region of the Earth. The number of sudden stratospheric warmings (SSW) over Eurasia has doubled over the past 20 years if compared with the second half of the 20th century. As a result, one had an increase in dangerous weather phenomena associated with those stratospheric-tropospheric interactions. In this regard, there is a certain need for an early forecast of such dangerous weather phenomena and their study within the framework of the climate of a given region. The paper presents a possible mechanism of the interaction of the mesosphere, stratosphere and troposphere layers (the so-called “ozone mechanism”). Due to its orographical and geographical position, the northern region of the East European Plain is characterized by accumulation of total ozone (TO) over this territory and formation of sharp and severe colds during SSW. The conclusion is made about the key contribution of the “ozone mechanism” to the development of SSW in 2018, which has become the largest in the Northern Hemisphere over the past 20 years.