青海省一次暴雨过程预报误差分析

Analysis of Forecast Errors in a Heavy Rain Process in Qinghai Province

本研究利用常规气象观测资料、NCEP1°×1°格点再分析资料等,采取诊断分析方法,对2018年7月22日至23日青海东部一次暴雨过程的成因进行分析并对数值预报进行检验,探索此类天气预报方法。结果表明,这是一次典型的副高东退、"北槽南涡"形势下的暴雨过程,第十号台风"安比"在副高南侧活动,副高外围偏东、偏南气流旺盛,水汽输送加强,多个系统的综合影响使得青海东部产生大范围强降水。此次对大雨、暴雨落区预报出现误差,主要是由于多个数值模式产品对副高势力预报偏弱、大量级降水落区预报偏北,影响预报员对强降水落区的综合判断。

Based on the conventional meteorological observation data and NCEP 1 °× 1 ° grid reanalysis data, the causes of a rainstorm in the east of Qinghai Province from July 22 to 23, 2018 were analyzed and the numerical fore cast was tested in this study. The results show that this is a typical rainstorm process under the situation of subtropi cal high retreating eastward and "North trough South vortex", The 10th typhoon "Ampil" is active in the south side of the subtropical high, with strong air flow in the East and south of the periphery of the subtropical high, enhanced wa ter vapor transmission and the comprehensive influence of multiple systems, resulting in large-scale heavy rainfall in the east of Qinghai. The forecast error of heavy rain and rainstorm area is mainly due to the weak forecast of subtropi cal high force and the North forecast of large-scale precipitation area by multiple numerical model products, which affects the forecaster's comprehensive judgment of heavy precipitation area.