Droughts in western Central Europe and associated atmospheric circulation patterns since 1844

Droughts in western Central Europe have major impacts on agriculture, ecosystems, and society, yet their long-term variability and drivers remain poorly understood. This study investigates drought variability over the past 180 years and its link to atmospheric circulation. Three reanalysis datasets (ERA5, 20CRv3, and ModE-RA), evaluated against long weather station observations, are used to identify meteorological drought events via the 3-month Standardized Precipitation (Evapotranspiration) Indexes (SPI-3 & SPEI-3), and to relate them to atmospheric circulation patterns through k -means clustering of 500 hPa geopotential height anomalies. Results show that recent severe and successive droughts have historical precedents and occur within pronounced multidecadal variability. Yet the 2010s emerge as the driest decade when assessed with SPEI-3, a feature that disappears when only precipitation is considered, highlighting the increasing contribution of atmospheric evaporative demand (AED) to drought severity. Although year-round SPEI-3 exhibits no long-term trend, increasing AED has progressively offset increasing precipitation, leading to contrasting seasonal responses with autumn and winter becoming wetter, whereas summer and, more recently, spring becoming drier. Four recurrent circulation patterns are identified across drought events in western Central Europe, with droughts becoming increasingly associated with the European High, characterised by large anticyclonic and positive AED anomalies. Droughts under this pattern occur mostly in spring and are particularly intense, offering a dynamical explanation for the recent emergence of spring drying.