High-Resolution Numerical Simulation and Impact Analysis of a Severe Convective Weather Process on the Kunming-Vientiane Route

During March 23 and March 26， 2020， an area along the international route from Kunming， Yunnan to Vientiane， Laos experienced severe weather conditions including hail， thunderstorm winds， and heavy precipitation.A severe convective weather process was simulated using the mesoscale numerical model WRFV4.2 （Weather Research and Forecasting Model） and FNL （Final Operational Global Analysis） data from the National Centers for Environmental Prediction （NCEP）.Hourly weather station data from the China Meteorological Administration was used to check the reliability of the simulation.Furthermore， a diagnostic analysis of various physical quantities output from the WRF model was performed to provide an aviation safety reference for the Kunming-Laos Vientiane route in Yunnan.The results show that： （1） the WRF model can better simulate temperature and precipitable water， but the simulated values of the near-surface wind field are large during the daytime.（2） The simulated output physical quantity field of the simulation can indicate the time and location of severe convective weather， which has certain spatial and temporal forecasting and warning functions and can be used to judge the impact of severe convective weather on flight and the degree of impact according to it.（3） The severe convection was mainly caused by the eastward movement of the Southern Branch Trough， with dry and cold air in the upper levels superimposed on the warm and moist air forming an unstable structure， triggered by the surface convergence lines.Convective available potential energy （CAPE） in the route area is large， and the water vapor conditions are abundant-the rising motion and sinking motion alternate below 9 km altitude， which can cause turbulence during flights.Additionally， the 0 ℃ layer is located at an altitude of about 3 km， which can cause ice to form on the airframe or encounter hail weather， causing a certain impact on flight safety.