阿勒泰东部地区暴雨过程的成因分析

Analysis of the Cause of Heavy Rain in the Eastern Part of Aletai

摘要: 利用常规气象观测资料、2015年6月29日阿勒泰地区降水资料以及EC模式细网格和T639模式细网格预报产品，对2015年6月29日阿勒泰东部地区暴雨天气过程的成因进行了天气学分析并检验了暴雨过程的数值模式预报的性能，结果表明：这次暴雨过程100 hPa上南亚高压呈双体型，500 hPa上欧洲长波脊是主导系统，而暴雨的主要影响天气系统是西西伯利亚长波槽，高低空环流形势和影响天气系统合理配置，尤其是中尺度系统活动是暴雨形成的主要原因。阿勒泰东部地区上空深厚的不稳定能量、较强的动力抬升作用、充沛的水汽条件和有利的迎风波地形效应是暴雨产生的缘由。在此次暴雨过程中，各家数值预报产品对于此次天气过程的高度场预报性能较好，与实况相差不大；但对东部暴雨动力条件、水汽条件的预报偏差较大，无参考价值；EC细网格对东部暴雨的雨量预报较接近实况。

Abstract: Based on the conventional meteorological data, EC model and T639 model of fine grid forecast products, we analyzed the cause of the rainstorm weather process in the east of Aletai on June 29, 2015, and analyzed the performance of the numerical model prediction of the rainstorm process. The results showed that the rainfall process on the South Asian high was 100 hPa double size; 500 hPa Europe long wave ridge was the dominant system; the main influence of rainstorm weather system was West Siberia wave trough, the level of air circulation and weather system reasonably; and especially the mesoscale system activity was the main cause of torrential rain. Over the eastern part of Aletai, the deep unstable energy, strong dynamic uplift, abundant water vapor conditions and favorable terrain effect were the causes of heavy rain. In the course of the storm, the performance of various numerical forecast products to predict height field for the weather was good, similar to the actual situation; but for the heavy rain in eastern dynamic conditions and water vapor condition, prediction showed a large deviation, which had no reference value; while EC fine grid rainfall forecast on the eastern rainstorm was closer to the truth.