貴州銅仁一次暴雨天氣過程成因分析

摘 要：2021年6月27日夜間至28日白天，貴州省銅仁市出現一次大范圍暴雨天氣過程，利用Micaps實況、NCPE再分析及自動站觀測資料，對該次暴雨過程的成因進行分析，為日后此類暴雨的預報提供參考。結果表明，該次暴雨過程是副東退至西太平洋上空，高空橫槽轉豎同時東移南壓影響銅仁，配合低層切變線和地面熱低壓共同影響，造成的強降水天氣，暴雨主要出現在高空槽前，低層切變線和地面輻合線附近，位于低空西南急流的北側；物理量場上，銅仁市位于水汽通量大值區北側，上空有水汽輻合，為暴雨的形成提供充足的水汽條件，濕層深厚，可轉換的對流位能充足，上層大氣始終處于對流不穩定狀態，暴雨形成的能量條件充沛，垂直速度上升區持續影響銅仁，為暴雨的產生提供動力抬升條件。

關鍵詞：暴雨；環流特征；預報；成因；銅仁

中圖分類號：P458 文獻標志碼：A 文章編號：2095-2945（2024）24-0094-04

Abstract： A large-scale rainstorm weather process occurred in Tongren City， Guizhou Province from the night of June 27 to June 28， 2021. The causes of this rainstorm process were analyzed by using Micaps， NCPE reanalysis and automatic station observation data， so as to provide reference for the forecast of this kind of rainstorm in the future. The results show that the rainstorm process is a sub-east retreat to the western Pacific Ocean， and the upper horizontal trough turns vertical and moves southward to affect Tongren. Based on the joint influence of the low-level shear line and the surface thermal low pressure， the rainstorm mainly occurs in front of the upper trough， near the low-level shear line and the ground convergence line， and is located on the north side of the low-level southwest jet. In the physical quantity field， Tongren City is located on the north side of the high value area of water vapor flux， and there is water vapor convergence above， which provides sufficient water vapor conditions for the formation of rainstorm， the wet layer is deep， the convertible convective potential energy is sufficient， and the upper atmosphere is always in a state of convective instability. The energy conditions for the formation of torrential rain are abundant， and the vertical velocity rising area continues to affect Tongren， providing dynamic uplift conditions for the generation of rainstorm.

Keywords： rainstorm; circulation characteristics; forecast; cause of formation; Tongren

對暴雨天氣的預報預警是氣象工作中面臨的重要問題，作為貴州省發生頻率最高的災害性天氣之一，常引發城市內澇，甚至山洪、滑坡或泥石流等次生地質災害，對當地人民的生命和財產安全造成嚴重威脅。暴雨的形成過程復雜多變，面對這一課題，各地的氣象工作者均進行有針對性的研究[1-10]。本文在前人的研究基礎上，從天氣環流形勢、物理量特征等方面對2021年6月27—28日銅仁市暴雨天氣過程的成因進行診斷分析。

1 實況分析

1.1 降水實況分析

2021年6月27日20時到28日20時，受高空槽、低層切變……