本文对南京地区2015年的一次强降雪过程进行了湿位涡诊断分析,根据2008-2015年的57次强降雪个例归纳出了积雪效率与地面2m气温的关系.结果表明:湿位涡正压项对降雪强度变化有较好的指示意义;结合湿位涡斜压项和地面气温可以较好地判断降雪落区,且强降雪落区和湿位涡斜压项的大值中心对应较好;积雪效率和地面2m气温是分段函数关系,利用该统计关系及气温、降雪量的预报,可以作出积雪深度的预报.%The Moist Potential Vorticity (MPV) of a severe snowstorm process during 2015 in Nanjing was diagnostically analyzed the firstly,and then,57 heavy snow cases during 2008 to 2015 were studied to conclude the relationship between snow accumulation efficiency and 2-meter temperature.Results showed that the barotropic item oMPV has good agreement with snowfall intensity.The snowfall area was well forecasted by combining the baroclinic item of MPV and the surface temperature,and the heavy snowfall area was well corresponding with the large value center of the baroclinic item of MPV.The snow accumulation efficiency was closely determined by surface 2-meter temperature.Their relationship,temperature and snowfall amount could be used to forecast the snowfall depth.
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