Impact of mountains on environments and estimated precipitation intensity of supercells

For decades, the role of mountains in influencing both a supercell environment during initiation stage and later storm dynamics was poorly understood. Since the consequences of terrain-induced effects on supercells seem to play a crucial part in the distribution of convective precipitation at least in mountainous regions, several topic-focused papers have already been published particularly in the last fifteen years. Our contribution to the issue is based on the examination of two-dimensional radar data of 62 supercells that initiated over the western part of the Carpathian Mountains in Central Europe in the years 2015–2019. To investigate the basic spatiotemporal characteristics and estimated precipitation intensity of storms, mainly Doppler and pseudo-CAPPI products from the Slovak weather radar network were employed in the study. Potential impact of terrain asymmetry on supercells precipitation intensity through their lifetime was evaluated by the relationship between morphometric variables of the terrain and radar reflectivity factor within the proximity (5, 10, 15-km radius) of detected mesocyclones in 5-min radar scans. Subsequently, atmospheric conditions along with convective parameters during the events were simulated in the COSMO model. Initial environments were compared with actual radar reflectivity properties (e.g., area of reflecting radar pixels >50 dBZ) of storms and their propagation qualities such as translation speed, duration, and track length. Although no general connection of radar reflectivity to underlying terrain even with a time shift up to 30 min was found, increasing reflectivity of some supercells showed preferences to more unstable environments which clearly were related to orographic modification. Besides, the poster highlights several other intriguing findings of supercells behavior over complex terrain.