摘要
利用常规气象观测资料、NCEP/NCAR再分析资料以及雷达、卫星等资料,对2013年6月21日和2014年8月11日遵义市习水河流域两次局地特大暴雨的天气形势场,热力、动力和水汽条件,结合地形特征进行对比分析。结果表明:16.21暴雨大陆高压控制我国中东部地区,受高压阻挡,低层低涡切变主要影响四川中东部,低涡未整体东移,仅850 h Pa冷式切变影响遵义西北部;8.11暴雨降水区中低层处于槽前正涡度区,高层200 h Pa处于南亚高压脊线附近,垂直方向上存在正向环流圈,受副高稳定维持阻挡,中低层低涡切变及地面辐合线东移缓慢,较长时间停留在强降水区域。2两次过程雷达回波反射率因子均呈带状分布,且回波移动方向与带状回波长轴一致,具有典型的"列车效应",剖面显示均为低质心结构,降水效率高。36.21暴雨能量条件比8.11暴雨好,但水汽条件和动力条件不及8.11暴雨。4受习水河谷地形影响,6.21暴雨和8.11暴雨强降雨落区分别与习水河谷赤水段和习水段走向一致。
Based on conventional observation data,NCEP/NCAR reanalysis data,satellite imagery and radar data,comparative analysis on the weather situation,the heat,power and water vapor conditions for the two local extraordinary storm in Zunyi Xishui River Basin during June 21,2013 and August 11,2014 was done,combining with terrain features.The results show that: 1) 6.21,high pressure control in eastern China,stopped by high pressure,low vortex shear layer mainly affects the Middle East Sichuan,the whole vortex did not discernibly move eastward,only the 850 h Pa cold shear effect in northwestern Zunyi;8.11,rainstorm precipitation area was located next to Trough the positive vorticity area in low- middle layer,high 200 h Pa in the vicinity of South Asia high ridge.There is a positive circulation on the vertical direction by the subtropical high,maintain stable block,low vortex shear and surface convergence line eastward slowly,stay a long time in the strong rainfall area.2) the6.21 rainstorm energy condition is better than that of the 8.11 rainstorm,but the water vapor condition and the dynamic condition are less than the rainstorm of 8.11.3) by the Xishui river valley topography,6.21 rain and 8.11 heavy rain Rainfall zone were consistent respectively with Chishui section and Xishui section direction of Xishui valley.
出处
《贵州气象》
2017年第1期45-52,共8页
Journal of Guizhou Meteorology
基金
黔气科合KF[2015]03号
遵气科合KF[2016]04号
遵气科合KF[2016]01号
2015年贵州省气象局创新团队项目
关键词
特大暴雨
低涡
低空急流
列车效应
地形影响
extra heavy rainstorm
low vortex
low level jet
train effect
orographic influences