2013年5月27日赣东区域性暴雨成因分析

为了提高暴雨预报准确率和预报服务水平，利用常规气象资料、NCEP 1°×1°再分析资料，对2013年5月27日赣东抚州市区域性暴雨成因从天气形势、影响系统、水汽、动力与热力不稳定等方面，运用垂直螺旋度理论进行综合分析。结果表明：（1）此次暴雨过程是一次江淮气旋东移过程中暖区短历时强对流暴雨，江淮气旋、500 hPa低槽、中低层低涡、西南风急流是暴雨主要影响系统；（2）暴雨区与垂直速度所表现的强烈上升区对应，并伴有高能高湿条件；暴雨区位于850 hPa水汽通量大值中心附近和温湿能等值线梯度密集带偏高值一侧；水汽通量散度负值中心与强降水区有较好的对应关系；（3）垂直螺旋度分析表明，这次暴雨落区位于700 hPa垂直螺旋度正大值中心附近，强降水出现与中低层的正螺旋度迅速增大，高层负螺旋度值迅速减小在时间上有一致性。分析结果对今后暴雨预报有指导意义。

Causation Analysis of a Regional Heavy Rainstorm: Eastern Jiangxi, May 27, 2013

Based on conventional meteorological data and NCEP 1°×1° reanalysis data, a regional heavy rainstorm in Fuzhou, eastern Jingxi on May 27, 2013 was analyzed with the theory of vertical helicity from the aspects of weather situation, influence system, water vapor, dynamic and thermal instability. The results showed that: (1) the regional heavy rainstorm occurred in the warm sector while the Jiang-Huai cyclone moving eastward, it was a short diachronic strong convection rainstorm, Jiang-Huai cyclone, 500 hPa trough, low vortex and the southwesterly jet were the main influencing systems of the rainstorm; (2) the heavy rainfall region was corresponding with the strong ascending region of vertical speed, and accompanied with the high energy and high wet regions, the area of rainstorm was located at the large water vapor flux value center and the greater value side of 850 hPa temperature-moisture energy, the water vapor flux divergence negative center had good corresponding relationships with strong precipitation area; (3) the rainstorm drop area was almost located in the vicinity of positive center of 700 hPa vertical helicity, the time of the absence of strong precipitation was consistent with the time when positive vertical helicity quickly increased at low and middle level, and negative vertical helicity quickly decreased at high level. The analysis result has directive significance for the forecast of heavy rainstorm in the future.