A case study of a severe hailstorm in Mendoza, Argentina, during the RELAMPAGO-CACTI field campaign

Abstract

Storms in central Argentina are known for producing large and severe hail. Environmental conditions and strong interaction with topography in this region provide unique conditions for the initiation and intensification of severe storms. The RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations) and CACTI (Clouds, Aerosols, and Complex Terrain Interactions) field campaigns deployed between October 2018 and April 2019 over west-central Argentina have collected unprecedented periods of intensive observation in the region. During the Intense Observation Period (IOP) number 10 (November 26, 2018), 4 cm diameter hail was reported over wide areas of the province of Mendoza. This was the first time a severe hailstorm was measured with multi-platform observations in Mendoza as the IOP deployment included multiple atmospheric soundings, observations from the Center for Severe Weather Research (CSWR) Doppler on Wheel radars (DOWs) and high temporal resolution satellite data from the Advanced Baseline Imager (ABI) and the Geostationary Lightning Mapper (GLM) onboard GOES-16. High-temporal frequency soundings and surface observations collected prior to the convection initiation are analyzed, allowing a detailed description of the pre-convective environment. The establishment of the upslope flow and the role of boundary layer processes that resulted in the development of the severe hailstorm are also analyzed. In addition, several GOES-16 ABI and GLM derived products are investigated, in order to test their ability to forecast convective initiation and provide hail proxies in the region.