Introduction to the Short-Term Aviation Weather Forecasting System in North China

The first-generation short-term aviation weather forecasting system has been developed by the Civil Aviation Administration of China (CAAC)/ Meteorological Center of Air Traffic Regulator of Civil Aviation in North China. The system has been established, which can assimilate the hourly radar data in North China and provide the 0-9 h forecasts of severe convection. Complex cloud analysis technique is applied in the assimilation with radar reflectivity data to modify the hydrometeors and the temperature in the clouds, which benefits the prediction of the occurrence, development and evolution of severe convection and shortens the spin-up time of the forecasting system. In addition, the dynamical characteristics of severe convection are improved by the assimilation of radar radial velocity in the WRF three-dimensional variational data assimilation (3DVAR) system. This short-term forecasting system has been implemented since 2014, and significantly improves the operational aviation weather forecasts in North China.