What Do Large Hail, Tornado, and Severe Thunderstorm Wind Environments Have in Common across Continents?
Year: 2026
Type: article
Abstract: Studies evaluating convective storm environments have historically focused on single continents. Here, we considered severe weather reports (hail, tornadoes, severe convective winds), lightning detection data, and the fifth generation ECMWF atmospheric reanalysis (ERA5) across four parts of the world: Europe, Australia, South America, and the United States. We analyzed convective parameters and vertical profiles of atmospheric quantities for severe and nonsevere thunderstorms to better understand which environmental features share similarities among continents. Thermodynamic parameters are the most useful proxies of hail and warm-season severe winds, whereas kinematic parameters are the most robust predictors of storm severity, especially tornadoes, whose environments feature a large contribution of low-level streamwise vorticity. For hail, the strongest and most skillful depth of bulk wind shear is located around 1–4 km above ground level, unlike tornadoes and cold-season severe winds, which have the largest shear near the ground. Larger hail and stronger tornadoes can be expected with increasing low-level storm-relative winds and their perpendicular component in the midtroposphere. Extending a hodograph to its origin while calculating storm-relative helicity and streamwise vorticity improves tornado prediction, especially considering the lowest few hundred meters above ground level. Lifted parcel buoyancy in the hail growth layer (−10° to −40°C), especially its peak value, is important for assessing the likelihood of hail. We also note that some parameters are geographically dependent (e.g., lapse rates, mixing ratio) and that parameters which are good predictors for the occurrence of convective hazards may not be the best parameters to infer their intensity, and vice versa. Significance Statement We compared atmospheric environments linked to hail, tornadoes, severe convective winds, and nonsevere thunderstorms across Europe, Australia, South America, and the United States. The aim was to pinpoint intercontinental similarities in features driving specific convective hazard occurrence and their severity. Analysis revealed that focusing on aspects of atmospheric profiles that provide robust, intercontinental signals—and adjusting environmental parameters accordingly—can yield more skillful predictions of convective hazards. Notably, extending the hodograph to its origin when calculating storm-relative helicity improved tornado prediction, while peak lifted parcel buoyancy (especially in the subfreezing part of the profile) paired with 1–4-km wind shear boosted large hail prediction. We also found that some parameters such as mixing ratio or temperature lapse rates exhibit geographic dependencies. Therefore, we recommend operational forecasters and researchers should exercise caution when applying findings or parameter thresholds from one region to another.
Institutions: Adam Mickiewicz University in Poznań, European Severe Storms Laboratory, European Severe Storms Laboratory - Science and Training, Central Michigan University, University of Oklahoma, The University of Melbourne, Pennsylvania State University, Universidad de Buenos Aires, Instituto Franco-Argentino sobre Estudios de Clima y sus Impactos, Fundación Ciencias Exactas y Naturales, Centre National de la Recherche Scientifique, Consejo Nacional de Investigaciones Científicas y Técnicas, Institut de Recherche pour le Développement, National Oceanic and Atmospheric Administration, NOAA National Severe Storms Laboratory
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
OpenAlex ID: W4413131940