SPATIO-TEMPORAL VARIABILITY OF PRECIPITATION OVER THE WESTERN BALKAN COUNTRIES AND ITS LINKS WITH THE ATMOSPHERIC CIRCULATION PATTERNS

Temporal and spatial variability of annual and seasonal precipitation from 71 stations located in Western Balkan (WB) countries (Serbia, Bosnia and Herzegovina, and Montenegro) and their correlations with nine atmospheric circulation patterns was examined for the period 1950-2016. Annual precipitation increased significantly throughout the WB (from 2% to 8% per decade) on 20% of stations located mainly in the mountainous western Serbia and eastern Bosnia and Herzegovina. Winter was characterized by non-significant precipitation changes in most of the studied area, with only a few stations characterized by significant precipitation increase (up to 12% per decade) in the mountainous area of WB, and a few stations characterized by significant decrease (up to -6% per decade) in the Pannonian plain. Significant precipitation increase was noticed on 15% of the stations in spring, while it was noticed on 17% of the stations in autumn. Summer precipitation decreased significantly (up to -5% per decade) on a limited area of northern Serbia (6% of the stations), while the majority of stations showed non-significant increase. The strongest influences on annual precipitation in WB region are of the Arctic Oscillation (AO) and Mediterranean Oscillation (MO), leading to the precipitation decrease during their positive phases. Winter precipitation is significantly negatively correlated with AO, East Atlantic/Western Russia oscillation (EA/WR), and North Atlantic Oscillation (NAO) and has a significant positive correlation with Western Mediterranean Oscillation (WeMO) on the majority of stations. MO has the strongest influence on summer precipitation in WB region leading to precipitation decrease, while AO has the dominant influence on precipitation in the region during autumn.