2013年南疆两场罕见暴雨落区和强度的对比分析  

Comparison of Precipitation Area and Intensity of Two Rare Heavy Rainfall Area and Intensity over Southern Xinjiang in 2013

作　　者：张俊兰 魏荣庆 杨柳 

机构地区：[1]新疆维吾尔自治区气象台,新疆乌鲁木齐830002 [2]巴音郭楞蒙古自治州气象局,新疆库尔勒841000

出　　处：《沙漠与绿洲气象》2014年第5期1-9,共9页Desert and Oasis Meteorology

基　　金：国家科技支撑计划项目(2012BAC23B01);中国气象局预报员专项项目(CMAYBY2013-079;南疆西部短时暴雨的成因及其预报方法研究)共同资助

摘　　要：对比分析了2013年5月26—28日和6月15—18日南疆两场罕见的暴雨过程,揭示了6月15—18日暴雨落区位置偏北、强度更强、持续时间更长的成因。6月15—18日暴雨的环流经向度更大,高、中、低纬低槽同位相叠加,环流形势属北槽南涡型,地面高压范围大且主体偏北,表现为冷锋涡旋云系,因此暴雨落区偏北、范围更大;6月暴雨的低层水汽输送更强、低层水汽输送时间更长,主要表现为:有西方+南方+东方3条水汽输送路径(5月的暴雨仅有西方路径),700hPa以下高度、水汽通量>4×10-3g·cm-1·hPa-1·s-1持续了42h(5月的暴雨仅持续12 h),>4×10-3g·cm-1·hPa-1·s-1的水汽输送层达到600 hPa(5月的暴雨为700 hPa),低层水汽输送最强值为12×10-3g·cm-1·hPa-1·s-1(5月的暴雨为10×10-3g·cm-1·hPa-1·s-1),因此强度更强、持续时间更长;中尺度切变线和涌线在暴雨落区预报中具有一定的指示意义。Two rare heavy rainfall processes appeared in the southern Xinjiang during 26th-28 th May and 15th-18 th June 2013,using the surface observation data,upper sounding data,daily NCEP/NCAR 6h 1° ×1° reanalysis data and ECMWF 0.25° ×0.25° fine grid NWP products,the causes of difference of area and intensity of two rare heavy rainfall were compared and analysed.Both of two rare heavy rainfall happened at the favorable circulation background,the degress of upper meridional circulation increased of the stronger heavy rainfall, the central Asia trough and the north trough got through and extended to south and more to south,the low layer of 700 hPa water vapor ation is more important than the middle and top, The daily forecast should pay more attention to the low level of water vapor input. From the heavy rainfall intensity contrast, the heavy rainfall intensity may be stronger when the low level water vapor transport more strong（more water vapor path, more water vapor input boundary, more water vapor flux and water vapor transport quantity）,the time of water vapor transport was longer in the low layer and the low-level shear line of duration was long and extended to the top. The mesoscale shear-line and swell line has the certain instruction significance in the forecasting heavy rainfall area.

关 键 词：南疆暴雨 落区和强度 低层水汽输送和输入量 中尺度切变线 

分 类 号：P458.121.1[天文地球—大气科学及气象学]