应用基本观测资料及NCEP再分析资料，对一次漏报的内蒙古东北地区致灾大到暴雪天气进行了诊断分析。结果表明：本次大暴雪天气过程与内蒙古大雪、暴雪天气学概念模型有所不同，没有强劲的水汽输送建立，垂直上升运动大值区集中在850～500hPa层，强降雪呈现时间短、强度大、范围小、灾害严重的中尺度特点。这次过程中，850hPa有很强的暖平流配合500hPa西南气流中弱冷平流，对流层中低层温度平流随高度减小，有利于对流层中低层的不稳定层结的建立；地面副冷锋与气旋合并加强，850hPa中尺度低涡强烈发展，加强了对流层低层的辐合上升运动，触发不稳定能量释放是强降雪形成的主要原因。边界层“冷垫”作用对强降雪有一定的增幅。%Using basic observational data and NCEP reanalysis data, a disastrous snowstorm weather of missing report in the northeast of Inner Mongolia was analyzed diagnostically. The results showed that this snowstorm weather process is different from the conceptual model in synoptic meteorology of snow storm in Inner Mongolia. There is no powerful water vapour transport, the large value area of vertical as cending motion is concentrated between 850 hPa to 500 hPa, and the heavy snow has the mesoscale charac ters of short duration, great intensity, small range and serious disasters. In this process, the powerful warm advection of 850 hPa is cooperated with the weak and cold advection in the southwest airflow of 500 hPa, the temperature advection in the lower troposphere decreases with altitude which is of benefit to the construction of unstable stratification, the mergence and reinforcement of ground secondary cold front with cyclone and the intensive development of mesoscale low vortex of 850 hPa strengthen convergence ascend ing motion in the lower troposphere, and unstable energy release is the main cause of snowstorm. Finally, the ＂cold wedge＂ of boundary has some amplification effect on heavy snow.
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