Heat and cold waves on the southern coast of the Baltic Sea

Abstract

The objective of this study was to describe the characteristics of heat and cold waves on the southern coast of the Baltic Sea, and determine synoptic situations causing the occurrence of the waves. The analysis included six stations located on the southern coast of the Baltic Sea. In the study, an extreme warm day was defined as a day with the maximum temperature over the 95th annual percentile, while an extreme cold day as a day with the maximum temperature below the 5th annual percentile. A sequence of at least five extreme warm and cold days was considered, i.e. heat or cold waves, respectively. In the analysed multiannual period, on the southern coast of the Baltic Sea, there were from 11 (Świnoujście) to 28 (Arkona) heat waves recorded, while the number of cold waves was from 34 (Świnoujście) to 43 (Kołobrzeg). The occurrence of extreme warm and cold days creating heat and cold days was connected with positive anomalies of sea level pressure and isobaric surface 500 hPa, which showed the presence of the high pressure systems.