基于空间检验技术的甘肃河东地区短时暴雨预报产品误差分析

Error Analysis of Short-term Rainstorm Forecast Product Based on Spatial Test Technology in Hedong Area of Gansu

以6个短时暴雨过程为例,采用空间检验技术对甘肃河东地区短时暴雨预报产品误差进行分析。结果表明:降水概率预报对于系统性降水过程预报准确度明显高于突发性降水过程;短时暴雨预报方法的预报位置较实况偏东偏南,纬度偏差-2.1°~1.3°,经度偏差-0.4°~3.1°;强度较实况偏弱,61%本地预报方法雨强为实况的0%~90%;降水范围较实况偏小,偏小程度最多仅6个格点;强度误差占比最大,其次为范围误差,位移误差最小。预报员可基于本地短时暴雨预报方法对预报误差进行相应的调整。

In this paper,we selected six short-term rainstorm processes as examples and used spatial verification technology to quantitatively analyze the errors of the short-term rainstorm forecast products in the Hedong area.The results show that:the accuracy of the local precipitation probability forecast for the systematic precipitation process is significantly higher than that for the sudden precipitation process;The result of the local short-term rainstorm forecasting method is located in the east by south,with a latitude deviation of -2.1°-1.3°and longitude deviation of -0.4°-3.1°;The intensity is weaker than the actual situation,and the rainfall intensity of 61% local prediction method is 0%-90% of the actual situation;The precipitation range is smaller than the actual situation,with only 6 grid points at most;The proportion of strength error is the largest,followed by range error and displacement error is the smallest.According to the above error characteristics,forecasters could adjust the prediction error effectively based on the local short-term rainstorm prediction method.