【摘要】 利用实况观测资料和NCEP/NCAR再分析资料,通过统计学和天气诊断分析的方法,对桂西2011年1月持续的低温天气进行分析,结果表明:极涡呈偶极型且位于亚洲北部的中心偏东、偏南是此次低温天气维持的环流背景特点;华南沿海的静止锋维持但坡度较大,不利于形成明显的逆温条件,是桂西主要出现阴雨天气而不出现冻雨的主要原因,海拔较高的北部山区局部出现的冻雨天气是由于特殊地形下的逆温层结造成的,维持时间较短;阻塞形势的建立和维持是低温天气维持的主要原因,阻高崩溃、横槽转竖的过程使桂西气温更明显下降;南支槽的两次东移使桂西产生较明显降水,对降温有明显影响。更多还原

【Abstract】 Basing on the observations and NCEP / NCAR reanalysis data,using synoptic diagnosis and statistic methods,the prolonged cold weather in western Guangxi in 2011 January were analyzed.It shows the circulation background characteristics of this weather course.Polar vortex was dipole type and located southeast in the center of Northern Asia.The stationary front remains in South China coastal but steeper is not conducive to a significant temperature inversion formation.That is the major reason of the rainy weather without freezing rain in the west of Guangxi.The inversion layer of special terrain of high altitude areas of northern Guangxi caused the freezing rain.The establishment and maintenance of the blocking situation is the main reason of the prolonged cold weather.Blocking high collapsing and transverse trough turning vertically make western Guangxi temperatures decrease.The southern branch trough shifting eastward twice produces the significant precipitation and cooling.更多还原