Synoptic conditions for rapid snowmelt in the Polish-German lowlands

Circulation patterns favourable for rapid snowmelt in the Polish-German lowlands are described in the study. Composite maps of the SLP and 500 hPa geopotential heights means and composite anomaly maps, constructed for the days with the decrease in snow cover depth of a parts per thousand yen5 cm/day, show deeper than usual low-pressure systems over the northern Atlantic and slightly higher than usual pressure over the Mediterranean. Such pressure patterns corresponds to the positive NAO phase with large pressure gradients, which intensify west and south-west air flows over Central Europe. Warm and humid air masses from the west and south-west contribute to substantial daily temperature increases and, frequently, to higher-than-usual precipitation, which speeds up ablation.