Changes in precipitation over the East Herzegovina region

Abstract

Changes in annual and seasonal precipitation over the East Herzegovina region in Bosnia and Herzegovina during the 1961-2016 periods were analyzed based on data sets of daily precipitation from 14 meteorological stations and rainfall gauges. The results show a downward trend in annual precipitation over the entire East Herzegovina region. Seasonal trend analysis showed that negative trends prevailed throughout the year, except in autumn season. Most prominent negative trends were registered in summer season throughout the region. In winter and spring season, precipitation displayed trends of both sign (although a downward trend prevailed). In the autumn season, precipitation has increased almost throughout the entire East Herzegovina region. However, a majority of estimated trends in annual and seasonal precipitation were weak and statistically insignificant. Prevailing negative values of the Rainfall Anomaly Index since the 1990s also suggest that precipitation reduction was present over the East Herzegovina region. Analysis of the Cumulative Precipitation Anomalies showed that a dry period started in 1981 and still continues. Precipitation variability was strongly dictated by the large-scale atmospheric circulation patterns over the Northern Hemisphere, such as the North Atlantic Oscillation, the East Atlantic/West Russia pattern and the Arctic Oscillation, particularly during winter season.