In southern Brazil, severe convective wind events are frequent and socio-economically significant. However, detailed analyses of their synoptic and pre-storm environments remain limited, in part due to the scarcity of proximity atmospheric soundings. This study examines four severe convective wind gusts ( \(\ge\) 25 \(m {s}^{-1}\) ) recorded by weather stations operated by Brazil’s National Meteorological Institute (INMET) in southern Brazil, for which proximity soundings were available. Surface data showed that gust passages were accompanied by temperature drops of 4.5-12.5 \(^{\circ }\) C and pressure rises of 2–4 hPa. Proximity sounding profiles revealed environments with high Convective Available Potential Energy (CAPE) for most unstable parcels (MUCAPE) and downdraft parcels (DCAPE). Two events exhibited extreme DCAPE and steep low-level lapse rates, reinforcing the role of strong evaporative cooling and downdraft potential in generating severe wind gusts. Meanwhile, deep-layer shear (DLS) showed more variability across the events. The sounding with the highest DLS had the lowest DCAPE, suggesting that momentum transport by downdrafts likely played a prominent role in severe wind generation. Assessment of gust estimation indices displayed limited skill. WINDEX effectively estimated gust magnitudes under strong thermodynamic forcing but underestimated cases influenced by vertical momentum transport or hydrometeor loading. GUSTEX 1 and GUSTEX 2 generally overestimated gusts, with GUSTEX 1 showing better performance when the 500-hPa flow was strong. Despite being based on four events, our results show the importance of considering multiple atmospheric factors when diagnosing severe convective winds and contribute to the limited documentation of pre-storm environments in South America using observed proximity soundings.
