气象2018，Vol.44Issue(1)：107-117,11.DOI:10.7519/j.issn.1000-0526.2018.01.009
弱天气尺度背景下太行山极端短时强降水预报失败案例剖析
Analysis of a Forecast Failure Case of Extreme Flash-Rain Under Weak Synoptic-Scale Background in Taihang Mountain
摘要
Abstract
In midnight on 31 July 2015,an extreme flash-rain event was happened in Taihang Mountain.The rainfall was more than 100 mm at 5 automatic weather stations (AWSs) in mountain areas of Shijiazhuang and Xingtai,of which Yuantou town of Shijiazhuang City and Nanzhonggao Town of Xingtai City were caught by extreme short-time intense rainfall with rainfall amount more than 50 mm · h-1 and more than 100 mm · (3 h)-1.However,the numerical prediction,the superior guidance forecast and meteorological observatory all failed to forecast this rainstorm.Based on conventional upper-level and surface observations,AWS data,Doppler weather radar data and numerical forecast test,this paper analyzed the prediction ideas and the reason of failure.The event occurred under weak synoptic-scale background in northeast of Tibetan high.The key of forecasting severe precipitation was to grasp the effects of east wind in Taihang Mountain and terrain.The middle-level northwest flow strengthened vertical wind shear,lowlevel shear line moved eastward,southwest wind strengthened warm moist air flows,and dry air layer overlaid on the thicken wet layer,strengthening the convective instability.The primary reason of the forecast error is that the lack of analyzing the maximum CAPE led to underestimating the unstable conditions and the development of thunderstorm at night in Shanxi Province.In addition,forecasters failed to use the unconventional data for real-time testing and correct numerical results,thus failing to predict the enhancement of thunderstorm enhance when it went down the hill.There is no effective conceptual model for severe precipitation conditions in the weak weather background at present.Forecast capacity of numerical model for such weather is poor.So forecasters need to improve the comprehensive analysis ability on observational data and the interpretation capacity of numerical prediction products in the future,and also to develop effective forecasting conceptual model through studying a large number of cases.关键词
弱天气尺度背景/太行山区/极端短时强降雨/预报失败原因Key words
weak synoptic-scale background/Taihang Mountain/extreme short-time rainfall event/reasons of forecast error分类
天文与地球科学引用本文复制引用
王丛梅,俞小鼎,刘瑾,李江波..弱天气尺度背景下太行山极端短时强降水预报失败案例剖析[J].气象,2018,44(1):107-117,11.基金项目
公益性行业(气象)科研专项(GYHY201506006)、国家自然科学基金项目(41575049)和中国气象局预报员专项(CMAYBY2017-010)共同资助 （气象）
