2016年一次寒潮天气过程诊断分析

Diagnosis Analysis of a Cold Wave Weather Process

利用常规气象观测资料、NECP/NCAR 1°×1°再分析资料和探空资料,应用天气学和动力气象学分析诊断方法,对2016年1月21—24日山西寒潮、大风和降雪过程的影响系统配置、冷空气移动路径和高低空环流形势演变进行了诊断分析,并对大风和降雪主要成因进行了分析。结果表明:此次寒潮过程属于"横槽型",500 h Pa上贝加尔湖东部的冷涡引导冷空气,沿西北偏西路径进入山西,以及地面冷高压南下是寒潮爆发的原因。850 h Pa存在强盛的冷平流,是产生寒潮天气的主要原因。但由于冷空气移动路径偏西,冷高压主体偏北,造成本次降温幅度只有个别站点突破历史极值。水汽条件较差,所以降水过程较弱;地面正负3 h变压差达10 h Pa,利于产生变压风,造成大风天气。

By using conventional meteorological observation data, NCEP/NCAR 1°× 1° reanalysis data and radiosonde data, adopting synoptic meteorology principle and methods, the authors analyzed the influenced system configuration, cold air path and changing circumstance of the high and low air circulation, and physical characteristics of a cold wave weather process in Shanxi during the Spring Festival of 2016, January 21-24. The results showed that： it was a ＂horizontal groove type＂ cold wave process, the cold eddy in the east of Lake Baikal of 500 hPa guided the cold air, and the cold air path belonged to the west by northwest, and the strengthening south of the ground cold high induced the cold wave in Shanxi; the main cause of temperature drop was the puissant cold advection in 850 hPa; but due to the cold air moving path by west, and cold high pressure subject was north, caused the cooling rate of only individual site break through the historical extreme value. Water vapor condition was bad, so precipitation was less; plus-minus surface variation in 3 hours was up to 10 hPa, which was beneficial to produce allobaric wind, then formed the strong wind weather.