Assimilation of C-band radar data using the SCALE-LETKF system: A supercell case study during the RELAMPAGO field campaign

PAULA SOLEDAD MALDONADO; JUAN RUIZ; CELESTE SAULO; TAKUMI HONDA; TAKEMASA MIYOSHI

Workshop; 6th Workshop on Mesoscale Modeling; 2023

Southern South America is frequently affected by strong convection that producesnegative impacts on the population and their activities. Forecasting high-impact weatherevents associated with deep, moist convection is an open challenge due to the limitedpredictability and observability of mesoscale circulations. In recent years, significantadvances have been made in using convective-scale numerical weather prediction anddata assimilation systems to produce very short-range forecasts (on the scale ofminutes) of high-impact weather events (see, for example, Yano et al. 2018). However,only few studies have focused on the application of high-resolution data assimilationsystems in South America (e.g., Vendrasco et al. 2020). Recently, the radar network inArgentina has been significantly expanded, creating new opportunities for theimprovement of very short-range forecasts of high-impact weather events. In this work,we investigate the implementation of an ensemble-based data assimilation system basedon the Local Ensemble Transform Kalman filter (LETKF) coupled with the ScalableComputing for Advanced Library and Environment (SCALE) regional model (Lien etal. 2017) and its performance in a case of a supercell thunderstorm that occurred incentral Argentina during the RELAMPAGO field campaign (Nesbitt et al. 2021).