CYCLONIC ACTIVITY IN COLD SEASON OVER TERRITORIES OF BELARUS AND UKRAINE AND ITS RELATION TO THE WARM SEASON DROUGHTS

Sa？etak Abstract. Cyclonic activity is a main mechanism for replenishing the soil moisture content due to precipitation. Low number of cyclones in winter can become a trigger for a drought in the subsequent summer period. This paper examines the conditions of cyclonic activity over the territory of Ukraine and Belarus and the drought frequency under current climate using syn- optic analysis and meteorological drought indices. Since the appearance of a drought is associ- ated with a certain blocking structure of the high-level pressure field, such patterns have been obtained and examined using proposed blocking index. Also it is shown that a decreasing of the amount of southern cyclones in winter has been accompanied by an increasing of drought- ness in summer, mainly over the southern regions of Ukraine. At the same time some shifting of the tracks of southern cyclones toward to the territory of Belarus was observed