Error Growth Characteristics In Simulated Storm Systems

For storm-scale weather systems, the current deterministic weather forecasting still has lots of uncertainties and difficulties. According to ensemble forecasting has made great success in the medium-term forecast numerical prediction, therefore the storm-scale introduction of Ensemble Prediction System technology has become a natural choice. However due to the storm system is highly nonlinear, the medium-term forecasting technology does not apply to storm-scale system, especially the way the initial disturbance. Hence owing to the storm-scale system characteristics, we need to investigate an appropriate method of introducing the initial error, and the characteristics of their growth, spread and evolution.Based on the above considerations, we choose two kinds of storm to investigate the initial error growth in them by using WRF model. The results show that: 1, The initial errors concentrate in the moist convective region (in the horizontal or vertical directions) in the entire process of the simulation after the beginning of the integration, and the initial errors grow with the intensification of the storm. 2, In the process of the model simulation, the peak value of different variables has different distributions in the vertical directions, such as, the errors of the temperature field mainly concentrated in the top of the model, and however the errors of the wind field mainly concentrated in the upper mid-troposphere. 3, The initial errors has no effects and changes on the style of the storm, but they a few changes on the position and intensity of the storm, especially light. 4, In the process of the error growth, especially in the first few minutes, the error growth is connected with the initial errors tightly, but later they were all controlled by the large scale environment. 5, the error growth is very consistent with the development of the storm (mainly before the error growth goes into saturation).At the same time, various types of the storm added with the initial errors have different process of the development. 1, for the supercell storm, the initial errors didn't change the type of the storm, but had some changes on the position and intensity of the storm. 2, for the multicell storm, although the initial errors have no change on the speed of the storm development, the have large changes on the distribution and intensity of the moist convective cells.3, for the allpert cases, the initial errors bring lots of small convective cells in the whole domain, and make themulticell storm end its life ahead of time.