2020年6月荆州地区一次强降水天气过程诊断分析

Diagnostic Analysis of a Heavy Precipitation Weather Process in Jingzhou Region in June 2020

利用常规高空和地面观测资料、探空资料等,对2020年6月12—14日荆州地区一次强降水天气过程的影响系统及其不稳定条件进行分析。结果表明:此次过程主要受高空低槽、中低层切变线和低空急流共同影响;过程雨量大,雨带自西向东移动慢且持续时间长,强降水时段集中且强度大,伴随雷电大风等强对流天气;强降水时段主要为12日夜间和13日夜间,期间均有切变线稳定维持;12日13∶00左右开始,随着西风槽东移,副高先东退后西伸,冷暖空气对峙,形势稳定,过程时间长;12日夜间急流加强,13日白天以系统性降水为主,17∶00~21∶00降水间歇,13日夜间对流单体再次生成和发展,前期以暖区对流为主,后期冷切尾部系统性降水;此次过程对12日白天—13日白天的降水强度把握得比较准确,对13日傍晚至夜间的强对流估计不足,对降水的开始结束时段把握较好,13日20∶00~14日20∶00预报量级偏小。

Using conventional highaltitude and ground observation data,sounding data,etc.,the influence system and unstable conditions of a heavy precipitation weather process in Jingzhou area from June 12 to 14,2020 are analyzed.The results show that the process is mainly affected by the high-altitude low trough,the middlelow-level shear line and the low-level jet;the process has large rainfall,the rain belt moves slowly from west to east and lasts for a long time,and the period of heavy rainfall is concentrated and strong,accompanied by thunder and strong winds.Iso-strong convective weather;the period of heavy rainfall is mainly the night of the 12th and the night of the 13th,during which the shear line is maintained steadily;starting at about 13:00 on the 12th,as the westerly trough moves eastward,the subtropical high first retreats eastward and then extends westward,warm and cold The air confronts,the situation is stable,and the process takes a long time;the night jet on the 12th strengthens,the daytime on the 13th is dominated by systemic precipitation,the precipitation is intermittent from 17:00 to 21:00,and the convective monomer regenerates and develops at night on the 13th.Convection is dominant in the area,and systematic precipitation at the end of the cold cut in the later period;this process has a relatively accurate grasp of the precipitation intensity during the daytime from the 12th to the 13th,and the strong convection from the evening to the night on the 13th is underestimated.The beginning and ending periods of the precipitation are underestimated.Good grasp,the magnitude of the forecast from 20:00 on the 13th to 20:00 on the 14th is too small.