Sensitivity of Tropical Cyclone Idai Simulations to Cumulus Parametrization Schemes

Weather simulations are sensitive to subgrid processes that parameterized in numerical weather prediction (NWP) models. In this study, we investigated the response of tropical cyclone Idai different cumulus parameterization schemes using Research and Forecasting (WRF) model with a 6 km grid length. Seventy-two-hour (00 UTC 13 March 00 16 March) were conducted New Tiedtke (Tiedtke), Simplified Arakawa–Schubert (NewSAS), Multi-Scale Kain–Fritsch (MSKF), Grell–Freitas, Betts–Miller–Janjic (BMJ) schemes. A simulation for same event was also convection scheme switched off. The twenty-four-hour accumulated rainfall during all three simulated days generally similar across six experiments. Larger differences found events away from cyclone. When resolved convective partitioned, it is scale-aware (i.e., Grell–Freitas MSKF) allow resolve most rainfall, while they less active. Regarding maximum wind speed, minimum sea level pressure (MSLP), scale aware simulate higher intensity Joint Typhoon Warning Center (JTWC) dataset, however, timing more aligned Global Forecast System (GFS), which providing initial conditions time-dependent lateral boundary conditions. Simulations off be those It simulates location farther southwest compared other schemes, BMJ path north after landfall. All as well GFS failed movement into Zimbabwe, showing potential impact shortcomings on forcing model. Our study shows use allows dynamics, resulting system grey zone. wrong peak need better performing global models provide downscalers.