摘要
利用铜仁市区域自动站资料、Micaps常规观测资料、NCEP/NCAR 1˚ × 1˚再分析资料、FY2E卫星云图资料、雷达回波资料等对2019年8月28日~29日铜仁市一次中级区域性暴雨过程的环流形势、水汽、动力及能量条件进行分析,并对数值预报的降水预报进行检验。结果表明:此次暴雨过程是由中低层低涡切变、冷空气、台风外围偏东急流及地面辐合线相互耦合而形成;暴雨区水汽辐合明显,铜仁市上空为正涡度区和强烈的垂直上升运动,为暴雨的形成提供了有利的条件;地形造成的近地面气旋性辐合及垂直上升运动,对本次暴雨过程的形成起到重要作用;“上干冷、下暖湿”的不稳定层结、强热力不稳定、一定强度的垂直风切变等条件,为此次强对流天气的出现提供了有利能量条件。EC及中央台的降水预报对于此次强降水过程具有一定的指示意义,但降水量级预报略偏小,降水落区比实况稍偏北。
The circulation situation, water vapor, power and energy conditions of a medium-level regional rainstorm process in Tongren City on August 28~29, 2019 were analyzed by using the data of the regional automatic station in Tongren City, the conventional observation data of Micaps, the 1˚ × 1˚ reanalysis data of NCEP/NCAR, the data of FY2E satellite cloud image, and the radar echo data, and the precipitation forecast predicted by numerical prediction was tested. The results show that the rainstorm process is formed by the coupling of low- and medium-level low vortex shear, cold air, easterly jet stream and ground convergence line in the periphery of typhoon. The water vapor con-vergence in the rainstorm area is obvious, and the sky above Tongren City is a positive vorticity area and a strong vertical upward movement, which provides favorable conditions for the formation of heavy rainfall. The near-ground cyclonic convergence and vertical upward movement caused by the terrain played an important role in the formation of this rainstorm process. The unstable layering, strong thermal instability, and vertical wind shear of a certain intensity of “dry and cold at the top, warm and wet at the bottom” provide favorable energy conditions for the emergence of strong convective weather. The precipitation forecasts of EC and Central Observatory have certain indicative significance for the heavy precipitation process, but the precipitation level forecast is slightly smaller, and the precipitation falling area is slightly northerly than the actual situation.
出处
《气候变化研究快报》
2023年第5期885-895,共11页
Climate Change Research Letters
