Journal of Arid Meteorology ›› 2021, Vol. 39 ›› Issue (3): 426-435.

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Cause Analysis of an Extreme Heavy Rainstorm Process on July 31 of 2018 in Hami of Xinjiang

FENG Yao1, Ayixianmu·niyazi1, Reyila·yunusi2   

  1. 1. Meteorological Bureau of Yizhou District of Xinjiang Uygur Autonomous Region, Hami 839000, Xinjiang, China;
    2. Hami Meteorological Bureau of Xinjiang Uygur Autonomous Region, Hami 839000, Xinjiang, China
  • Online:2021-06-30 Published:2021-07-16



  1. 1.新疆哈密市伊州区气象局,新疆哈密839000;2.新疆哈密市气象局,新疆哈密839000

Abstract: There was an extreme heavy rainstorm weather process in Hami on 31 July 2018, and continuous heavy rainfall caused heavy casualties and property losses. Based on NCEP reanalysis data, ground routine meteorological observation data, regional encryption automatic station precipitation data and FY2G infrared cloud map TBB data, this extreme heavy rainstorm was diagnosed and analyed. The results show that the extreme heavy rain occurred under the favorable largescale circulation background, the south Asian highpressure double body type was established, the eastern center was strong and the position was north, the western Pacific subtropical high was obviously north and west than the perennial. High and low level jet streams formed a coupling situation in the vertical direction above the rainstorm area, which strengthened the maintenance of rising motion and vertical transport of water vapor over the rainstorm area. The 850-200 hPa strong warm and humid air flow in southwest direction provided sufficient water vapor and dynamic conditions for the rainstorm. High temperature and humidity, strong wind speed convergence and special terrain uplift triggered convection instability, which provided thermal and unstable energy conditions for the extreme heavy rainstorm. Heavy precipitation occurred in convective cloud edge and the maximum gradient region with dense TBB isoclines, and the closer to the maximum gradient of TBB central value, the greater the rainfall intensity was. Numerical forecast products had certain forecasting capability, but for precipitation area and magnitude it was weaker.

Key words:  extreme heavy rainstorm, circulation situation, high and low level jet, physical quantities, mesoscale analysis

摘要: 2018年7月31日哈密市出现了一次极端大暴雨天气过程,持续强降雨造成了重大人员伤亡和财产损失。利用NCEP再分析资料、地面常规气象观测资料、区域加密自动站降水资料和FY2G红外云图TBB资料,对此次极端大暴雨进行诊断分析。结果表明:极端大暴雨发生在有利的大尺度环流背景下,南亚高压双体型建立,东部中心强且位置偏北,西太平洋副热带高压较常年明显偏西偏北;高低空急流在暴雨区上空垂直方向形成耦合形势,加强了暴雨区上升运动的维持和水汽的垂直输送;850~200 hPa强盛的偏南暖湿气流为暴雨提供了充足的水汽和动力条件;低层高温高湿,强风速辐合及特殊地形抬升触发对流不稳定产生,为极端大暴雨提供热力和不稳定能量条件;强降水发生在对流云团边缘TBB等值线密集的梯度最大区域,越接近TBB中心梯度最大处,雨强也越大。数值预报产品具有一定的预报能力,但对于降水落区及量级预报偏弱。

关键词: 极端大暴雨, 环流形势, 高低空急流, 物理量, 中尺度分析