中尺度天气的高空地面综合图分析

Mesoscale Weather Chart Analysis Techinique

中尺度强天气的预报能力非常有限,一个重要原因是在业务预报中,缺乏对中尺度对流天气发生的环境场条件和发生发展特征进行及时有效的分析。本文介绍了国家气象中心正在试行的中尺度天气的天气图分析方法。中尺度天气的天气图分析主要利用探空资料和数值预报相关参量资料,分析中尺度对流天气发生发展的环境场条件,包括高空综合图分析和地面分析。在高空分析中重视风、温度、湿度、变温、变高的分析,并通过将不同等压面上最能反映水汽、抬升、不稳定和垂直风切变状况的特征系统和特征线绘制在一张图上形成综合图,以更直观的方式反映产生中尺度深厚对流系统发生发展潜势的高低空配置环境场条件。地面分析包括气压、风、温度、湿度、对流天气现象和各类边界线(锋)的分析。国家气象中心的强对流天气预报业务试验表明,中尺度天气的天气图分析已经成为强对流天气潜势预报的重要依据。

Mesoscale severe weather forecasting ability is limited,in some sense for a lack of valid analysis on mesoscale conveclive systems and its favorable environments.This paper introduces the mesoscale weather chart analysis technique which was tested in the National Meteorological Center（NMC）.Mesoscale weather chart analyzes the favorable environmental conditions of mesoscale convective systems based on observational data and numerical weather forecast outputs.It includes upper-air composite chart and surface chart.In the upper-air composite chart,by analyzing wind,temperature,moisture,temperature change and height change,the diagnostic systems and features in all the lower,middle and upper troposphere isobaric layers are combined into one plot,which can clearly display the available environments and synoptic pattern of severe convective weather.In the surface chart,the analysis contents are pressure,wind,temperature,moisture,convective weather phenomena and all kinds of boundaries （fronts）.The test in NMC shows that mesoscale weather chart analysis is a dependable means for severe convective weather outlook forecasting.