利用DQCT实现2018年8月超历史极值暴雨的高质量模拟

An accurate simulation of extremely heavy rainfall evaluated in August,2018 by using DQCT

构建较全面的双级质量控制技术(DQCT).利用中尺度天气预报模式(WRF)对2018年8月下旬华南地区一次超历史极值的暴雨过程进行高分辨率数值模拟,并用DQCT评判暴雨的模拟效果.结果表明,在暴雨形势背景场中用WRF成功模拟大尺度季风风场、西南暖湿气流与低压交汇过程,并准确复制了造成高潭镇极端降雨的中尺度对流系统.总降雨量中的中γ尺度极值暴雨中心模拟得较为准确.该模式在24 h降雨量模拟中成功复制了暴雨中心的演变过程;在6 h降雨量模拟中较好地再现了中γ尺度雨带的演变过程.在暴雨重灾区高潭镇1 h降雨量演变过程的模拟中,总体降雨趋势与实况吻合较好.定性分析结果同步得到定量指标的验证.

We established a double-level quality control techniques(DQCT).A high resolution numerical simulation on an extremely heavy rainfall process occurring in South China in late August,2018 was carried out via the weather research and forecasting(WRF)model,and the simulation data were evaluated based on DQCT.A comparison of the simulation data with observation data produced the following conclusions:in the background fields,all the weather systems including various scales wind field such as the low in monsoon,the southwesterly airstreams and the mesoscale convective system were successfully simulated according to WRF;in the total rain belt,the meso-γscale centers of the maximum precipitation was successfully copied;in the 24 h rain belt,the development of the heavy rainfall area was well reproduced;in the 6 h rain belt,the evolvement of the meso-γscale rain belt of the heavy rainfall were well forecasted;in the time series of precipitation in Gaotan,the hourly rainfall trend was carefully embodied;the evaluating results from qualitative analysis were also proved right according to the quantitative analysis from evaluation indexes.