Extreme large-scale precipitation events in central Europe are determined by the synoptic pattern, which is typically characterized by cyclones moving there from the south. Herein, we demonstrate that this synoptic pattern is accompanied by large-scale anomalies of dynamic and thermodynamic variables that occur in specific regions before or during the precipitation event.
The extremeness of variables was evaluated by ERA-40 data by the obtained distribution function values. Precipitation events leading to 14 significant summer floods in the period between 1958 and 2002 were used as reference events.
The temporal correspondence of the anomalies among reference events was employed by selecting 26 synoptic predictors of extreme precipitation in the Czech Republic. The predictors cannot be considered individually because only opportune coincidences make the synoptic situations dangerous.
Days with minimum values of a combined EM index correspond to significant flood events in the Czech Republic.