New interpretations targeting European atmospheric circulation patterns and their association with climate-related hazard events in Romania.

Atmospheric circulation exerts a dominant influence on the occurrence, intensity, and spatial distribution of climate-related hazards in Romania. This study investigates the relationship between major European synoptic-scale circulation patterns, such as the Icelandic Low, Azores High, Atlantic Ridge, Scandinavian High, Greenland High, Eastern European High, and Saharan High; and the frequency and characteristics of high-impact weather events affecting Romania. Using a combination of reanalysis datasets, synoptic composites, and event catalogues, we identify the circulation configurations most commonly associated with heatwaves, severe convection (hailstorms, downbursts, tornadoes), heavy precipitation episodes, cold spells, and windstorms. Results highlight several robust linkages: for example, a persistent Icelandic Low centred near the British Isles frequently promotes south-westerly advection and heatwave development over Romania, while blocking patterns such as the Scandinavian High or Greenland High often favours cold-air intrusions and enhanced cyclogenesis over the Mediterranean and Black Sea region. By integrating circulation-type analysis with reported hazard events, this study provides an updated framework for understanding Romania’s exposure to climate risks, while raising the awareness that the atmospheric processes are developing at larger scales than national boundaries, making severe weather events strongly linked to the broader circulation.