秋季贵州北部一次暴雨特征分析

Characteristics of a Rainstorm in Northern Guizhou in Autumn

摘要: 利用TBB、Micaps、数值预报资料，研究贵州北部一次暴雨天气过程。研究发现：在亚欧中高纬度维持两槽一脊的形势下，中纬度地区河套及其后部的冷舌东移至华北平原，副热带高压、川渝地区交界两高切变、地面冷空气影响的共同作用下，贵州北部产生了一次暴雨天气，最大降水量168毫米。此次过程700 hPa川渝两高切变快速东移南下，贵州上空从高压后部偏南气流转前部偏北气流，850 hPa有低涡存在，低涡在东移南下的过程中减弱消失，地面以河套附近为中心的冷高压占据了我国大部地区，冷空气前沿冷锋已经南下至两广北部至贵州西南部，午后冷空气势力减弱，地面温度大部升高到28℃~30℃，到了夜间又有冷空气补充，降水增强。结合探空看到贵州均为上干下湿，夜间西部北部地区湿层向上伸展超过500 hPa，850 hPa黔东南地区也较干，同时热带气旋带来充沛的水汽。此次天气过程伴有雷电、短时强降水，夜雨特征明显。

Abstract: Using TBB, MICAPS and numerical prediction data, a rainstorm weather process in northern Gui-zhou is studied. It is found that under the situation of maintaining two troughs and one ridge in the middle and high latitudes of Asia and Europe, the Hetao and the cold tongue behind it in the middle latitudes move eastward to the North China Plain. Under the joint action of the subtropical high, the two high shear at the junction of Sichuan and Chongqing and the influence of ground cold air, a storm weather process has occurred in northern Guizhou, with a maximum precipitation of 168 mm. In this process, the shear between Sichuan and Chongqing highs at 700 hPa rapidly moved eastward and southward, and the air flow over Guizhou shifted from the south of the high pressure to the north of the front. At 850hPa, there was a low vortex, which weakened and disappeared in the process of moving eastward and southward. The cold high pressure on the ground centered near Hetao occupied most of China, and the cold front of the cold air has moved southward to the north of Guangdong and Guangxi to the southwest of Guizhou, In the afternoon, the cold air force weakened, and the ground temperature mostly increased to 28˚C~30˚C. At night, there was cold air supplement and precipitation increased. Combined with radiosonde, Guizhou is dry in the upper part and wet in the lower part. At night, the wet layer in the northern part of the West extends upward by more than 500 hPa, and 850 hPa is also dry in Southeast Guizhou. At the same time, tropical cyclones bring abundant water vapor. The weather process is accompanied by lightning, short-term heavy precipitation and obvious characteristics of night rain.