Hunan Province, A Limited Area Numerical Weather Prediction System And Preliminary

The numeric weather forecasting has got a great success in the last years,with the development of aerography,physics,computer and computing mathematics. The accuracy of the numeric weather forecasting is ascending steadily. Now the short-term forecasting is obviously better than the subjective forecasting and the usable time of prognosis is 7 days. The forecasting content includes not only prognosis as in the past but also the forecasting of various weather factors and weather phenomena. As the most essential method of fixed time,fixed point and quantitative forecasting,numeric weather forecasting has became the primary technical way of the medium-term and short-termforecasting.This article makes a elemental explore combining closely practical application and material computing resource and environment,which is based on the newest domestic and overseas numerical forecasting result,material content include:The article is put forward that the Hunan Numeric Weather Forecasting System should include communicate,the medium-term numeric forecasting,jhe limited-region forecasting,the mesoscale numeric forecasting database,the image management of numeric forecasting production,the explain and use of the forecasting production and the statistical detection. This plan makes it true that the medium-term numeric forecasting model (T106) nest mesoscalenumeric forecasting model(MM5),and it can change the lateral boundary of mesoscale model every 3 hours and ensures the real time of the numeric weather forecasting in the existing communication condition.The limited-region model consists of two components - a low-resolution global model and high-resolution regional model. The two components have identical vertical structure and physical process. The global spectral model component uses spherical harmonics as horizontal basis functions. The regional spectral model component is a primitive equation model on a stereographic projection and uses sine-cosine series as horizontal basis functions. The regional component predicts deviations from the forecasting of the global morjel component. A semi-implicit time scheme,time filting,initialization,horizontal diffusion are applied to these deviations in the regional domain.The article designs the mesoscale numeric forecasting modeK the scheme of objective analysis and four-dimensional data assimilation of global meteorologic data and the bidirectional nested scheme of MM5 model in detail. We tried to forecast main weather processes in 1999 with Hunan Limited-region Numeric Weather Forecasting System established primarily a.|id got a good effect. It shows that the design of the Hunan Limited-region Numeric Weather Forecast System is scientific and rational.