江西省2次区域性春季暴雨过程对比分析

Comparison Analysis of Two Regional Spring Rainstorm Process in Jiangxi

利用江西自动站观测资料和常规观测资料,对2017年3月9-10日和4月6-7日江西省2次春季暴雨天气过程进行分析,结果表明:1)"4·6"暴雨的雨强略大于"3·9"暴雨,但持续时间较短,2次春季暴雨的强度不大,但降水量均达到暴雨量级,且持续时间长、雨量范围广而均匀,无显著强对流天气;2)急流在"3·9"暴雨过程中有重要作用,水汽通量辐合是这次暴雨过程的决定因素,高空急流入口区右侧的上升区域与925hpa超低空低涡切变区域相对应,从而产生强烈的上升运动,是造成"4·6"暴雨的重要因素;3)"3·9"暴雨过程中,850 hpa上的水汽输送较强,而"4·6"暴雨过程的超低空水汽更为充沛,辐合和垂直运动更强;4)"4·6"暴雨下层辐合宽广,有利于上升运动。而"3·9"暴雨上层辐散区域宽广,垂直速度更大,动力条件更好;5)"4·6"暴雨的不稳定能量大且持续时间长,热力条件更有利于产生暴雨。

Using the observation data of Jiangxi automatic station and the conventional observationdata to analyze the spring rainstorm weather process in Jiangxi Province from March 9 to 10 and April 6 to 7, the results show that： 1）“ 4. 6”rainstorm is slightly larger than “ 3. 9”rainstorm, but theduration is shorter. The intensity of the two springstorms is not strong, but the precipitation of the twoprocesses has reached the level of heavy rain, and the duration is long, the rainfall range is wide andthere is no significant convective weather. 2） The rapids play an important role in the “ 3. 9”rainstorm, and the convergence of the water vapor flux is the decisive factor in the heavy rain process.The rising area on the right side of the highlevel jet inlet area corresponds to the 925 hpa lowaltitude lowvortex shear zone, resulting in a strong upward movement, which is an important factor inthe “ 4. 6”rainstorm. 3）Water vapor transport at 850 hpa is stronger in “ 3· 9“rainstorm process,and the water vaporin the ultralow level is more abundant, the convergence and vertical movement are stronger. 4） The lower convergence is broad in “ 4· 6”rainstorm, it′s conducive to the rise ofmovement. And the upper area divergence area is wide in “ 3. 9”rainstorm, the vertical speed is bigger, the power condition is more better. 5） The unstable energy is great in “ 4· 6”rainstorm, and it lasts for a long time, the thermal condition is more conducive to produce heavy rain.