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Abstract An average of 184 quasi-linear convective systems (QLCSs), including six derechos, occur every year across different parts of Europe, posing significant socioeconomic impacts. In this work, we analyzed convective environments and accompanying synoptic patterns associated with QLCSs, considering their intensity and spatiotemporal variability. For this purpose, we used the database with manually identified QLCS cases based on the Operational Program for the Exchange of Weather Radar Information (OPERA) radar data. In total, we investigated 1469 cases over a period of 8 years (2014–21), and for each case, we assigned a representative fifth generation ECMWF atmospheric reanalysis (ERA5) vertical profile sampling the preconvective environment. We found that warm-season cases develop primarily in a large atmospheric instability setup and are often driven by strong cold pools, whereas during the cold season, synoptic-scale lift with marginal (but nonzero) CAPE and high vertical wind shear is the most common environment. The mean vertical profiles indicate the dominance of westerly and southwesterly flow during QLCS development. Except for warm-season QLCSs over the West and cold-season cases in the Central region, QLCSs are associated with clockwise-curved hodographs. Our results indicate that the intensity of warm-season QLCSs is well represented by downdraft-related metrics such as downdraft CAPE (DCAPE). Marginal and stronger QLCSs can be distinguished using atmospheric instability (CAPE), especially across central Europe. In the cold season, kinematic parameters were found to discriminate well between the severity of QLCSs. Observed storm motion of QLCSs was typically faster than the 0–6-km environmental mean wind vector in the warm season (65% of cases), while in the cold season, it was opposite (84% of cases). Significance Statement Quasi-linear convective systems (QLCSs) are responsible for large socioeconomic impacts related to their potential to produce convective hazards, especially severe wind gusts. In this work, using the database of QLCS occurrence in Europe based on OPERA radar data over the years 2014–21 and fifth generation ECMWF atmospheric reanalysis (ERA5), we perform an analysis of their accompanying convective environments and synoptic-scale patterns. Although QLCSs typically develop over the east or southeast edge of the upper-level trough, we found that they are associated with a broad spectrum of conditions in different parts of Europe. Generally, cold-season QLCSs develop under strong synoptic-scale forcing, while warm-season cases are most often associated with high instability. Using downdraft-related metrics, mixed-layer CAPE, and bulk shear, it is possible to distinguish QLCS severity in specific seasons.