强对流天气分析与预报中的若干基本问题

Some Essential Issues Connected with Severe Convective Weather Analysis and Forecast

大量的预报业务人员对强对流天气中的大多数基本概念和基础理论"即熟悉、又陌生",这是造成强对流分析、预报过程中许多概念和理论被滥用,预报思路不清晰的重要原因。针对上述问题,本文从预报实践的角度讨论了与强对流有关的基本概念、基础理论以及它们在实际强对流预报中的应用问题。内容包括:湿度与水汽质量的关系,冷空气在降水过程中的作用,与静力不稳定、动力不稳定有关的基本理论,探空分析与不稳定参数,螺旋度、湿位涡理论与不稳定的关系,抬升速度、辐合线与对流垂直运动的关系,天气系统空间结构与强对流现象之间的内在关系等。

Many weather forecasters seem to have acquaintance with most of basic concepts or fundamental theories which are connected with severe convection,but some of them are misapplied frequently by some forecasters when they are engaged in severe convective weather analysis or forecasting argumentation.Due to the above problem,some basic concepts and fundamental theories should be explained from the view of forecasting application.The following issues are discussed in this paper.They are the relationship between humidity and water vapor content,the role of clod air during the precipitation process,the fundamental theories connected with thermal and dynamic instability,the sounding analysis related to instability parameters, the relationship between helicity or moist potential vorticity and instability,the relationship among the convergence line,lifting velocity and convective vertical movement,and the essential connection between the synoptic patterns and severe convective phenomena.