“2009.2”沈阳暴雪天气诊断与预报误差分析  

Diagnostic analysis of heavy snow in February 2009 and its forecast error in Shenyang

作　　者：梁红[1] 马福全[1] 李大为[1] 刘建国[2] 魏红 方斌[4] 

机构地区：[1]沈阳市气象局,辽宁沈阳110168 [2]铁岭市气象局,辽宁铁岭112000 [3]辽宁省气象局,辽宁沈阳110001 [4]辽宁省防雷技术服务中心,辽宁沈阳110016

出　　处：《气象与环境学报》2010年第4期22-27,共6页Journal of Meteorology and Environment

摘　　要：针对2009年2月12—13日沈阳暴雪过程,运用Micaps资料和自动站资料,分析了大尺度天气形势及相关物理量场。结果表明:500 hPa南北两支槽在辽宁的叠加和地面蒙古气旋及江淮气旋的合并是此次暴雪过程的主要成因。强降雪出现在850 hPa涡度和200 hPa散度大值区内,对流层中低层辐合、高层辐散为强降雪提供了有利的动力条件;低空急流为暴雪区水汽来源,亦为对流不稳定能量释放的触发源,暴雪区还具备上干冷下暖湿的热力不稳定条件;降水性质的转换与850 hPa的温度、温度平流和地面气温有直接联系;暴雪过程无论从量级,还是降水起止、雨转雪时间均预报得较为准确,但对降雪量和积雪深度估计不足。Based on MICAPS （meteorological information comprehensive analysis and process system） data and meteorological data from automatic stations, the synoptic situation and relative physical field of heavy snow on February 12-13,2009 in Shenyang were analyzed. The results indicate that the stacking of south and north ladder troughs in 500 hPa and integration of ground Mongolia cyclone and Jianghual cyclone are the main reasons form- ing the heavy snow. The heavy snow occurs in large vorticity area of 850 hPa and large divergence area of 200 hPa. The middle and lower convergence and upper divergence in troposphere provide favorable power for the heav- y snow. The low-level jet plays not only the vapor source of heavy snow area, but also the trigger source of relea- sing convective instability energy. There is the thermodynamic instability with the cold and dry upper level and the warm and wet lower level in heavy snow area. The conversion between rain and snow are related with temperature of 850 hPa, temperature advection and ground temperature. The heavy snow intensity, starting and ending times of precipitation, starting time of rain to snow are predicted accurately, except the amount of snow and depth of snow cover.

关 键 词：暴雪 环流形势 物理量 诊断分析 雨雪转换 预报误差 

分 类 号：P458.121.1[天文地球—大气科学及气象学]