Comparison between Multi-Physics and Stochastic Approaches for the 20th July 2021 Henan Heavy Rainfall Case

In this study, three model perturbation schemes, the stochastically perturbed parameter scheme (SPP), physics tendency (SPPT), and multi-physics process parameterization (MP), were used to represent errors in regional ensemble prediction systems (REPS). To study effects of different schemes on heavy rainfall forecasting, sensitive experiments using combinations (EXP1: MP, EXP2: SPPT + SPP, EXP3: MP SPP) set up based Weather Research Forecasting (WRF)-V4.2 for a case that occurred Henan, China during 20–22 July 2021. The results show can provide forecast uncertainties case. stochastic physical method could improve skill by approximately 5%, EXP3 had better performance than EXP1 or EXP2. spread-to-root mean square error ratios (spread/RMSE) closer 1 compared with those EXP2; particularly meridional wind above 10 m, spread/RMSE was 0.94 0.85 exhibited Brier score verification. 5% lower EXP2, when threshold 25 mm. growth initial variances explored, energy developed faster, magnitude 27.22 J/kg, whereas EXP2 only 19.18 J/kg 20.81 respectively. weak associated shear north location be easily EXP3.