对流天气预报中的环境场条件分析

中尺度对流天气的分析包括以天气型识别和中尺度过程分析为主的主观分析,以及以动力热力物理参数诊断为主的客观分析。利用"配料法"预报的思路,通过诊断有组织的深厚中尺度对流系统发生、发展的4个条件(水汽、不稳定、抬升和垂直风切变),开发了中尺度对流天气的环境场条件分析技术(对流天气图分析和客观物理量诊断技术),并应用于中国国家气象中心的强对流天气预报。以中尺度对流天气的天气图分析方法为例,介绍如何利用高低空观测资料,分析对流天气发生发展的环境场条件;并以数值模式释用为主的强对流特征物理量诊断分析为例,介绍如何动态诊断对流天气的动力热力条件演变。

Meso-scale convective weather analysis and severe convective weather forecasting

Meso-scale convective weather analysis involves the synoptic pattern recognition and the evaluation of meso-scale convective systems as well as the objective analysis of dynamical and thermo-dynamical parameters. This paper introduces the technique of meso-scale convective weather composite chart analysis and objective parameter diagnosis, which were used in the operational severe convective weather forecasting in the National Meteorological Center (NMC). We use ingredients-based forecasting methodology which evaluates the four basic conditions (moisture, instability, lifting and wind vertical shear) for well organized deep convective systems. This paper shows how to evaluate the favorable environmental conditions by analyzing the convective weather chart based on observational data and numerical weather prediction output data, and evaluating the dynamical and thermo dynamic conditions evolution through diagnosing the parameters favorable for the occurrence of the severe convective weather in light of numerical weather prediction outputs. The operational analysis test in NMC in 2009 shows that this technique is useful in the severe convective weather forecasting.