The south-eastern Europe winter precipitation variability in relation to the North Atlantic SST

• The winter precipitation of south-eastern Europe is correlated to the tropical North Atlantic (TNA) SST.
• The time lead of this relationship reaches up to two seasons.
• The TNA SST appears to affect the precipitation of this region by exciting a Rossby wave pattern.

The relationship between the North Atlantic sea surface temperature (SST) and the winter precipitation of south-eastern Europe is investigated and possible changes of this relationship in the past are explored, as such changes may be of significant importance for understanding the impacts of global warming on regional climate. The data used involve observational winter precipitation of 54 stations for the period 1959–2000 and the University of Delaware (UDel) gridded global precipitation, together with the NOAA Extended Reconstruction SST with 2.0° × 2.0° resolution and NCEP/NCAR reanalyses. The study focuses on interannual variations and a harmonic analysis is applied to the time series to exclude possible contamination of interannual relationship by interdecadal changes. The empirical orthogonal function (EOF) analysis on winter precipitation data shows that the first EOF, explaining about 44% of interannual variability, indicates a uniform behavior over the whole examined area and is highly correlated with the tropical North Atlantic SST anomalies with a time lead reaching up to two seasons. The observed relationship between tropical North Atlantic SST and south-eastern Europe winter precipitation can be attributed to a Rossby wave type response to tropical SST anomalies featuring a wave pattern from western tropical Atlantic to Europe.