2022年4月衡阳一次暴雨过程预报偏差分析

Analysis on Prediction Deviation of a Rainstorm Process in Hengyang in April 2022

摘要: 利用常规气象观测资料、区域自动站资料、Micaps资料、多普勒天气雷达资料、FY-4A卫星云图资料和ECMWF (以下简称EC)等数值模式预报资料，对2022年4月25~26日衡阳市暴雨过程进行了分析研究，得出此次暴雨过程预报落区偏大、范围偏南以及雨带走向偏差的原因。此次过程是发生在西南急流的控制下，急流轴上风速脉动引起的暖区暴雨，而不是模式预报的系统性降水；遇到模式预报存在分歧时，仍然过于信赖EC形势预报导致了此次暴雨预报出现偏差；当前数值模式对暖区暴雨的预报能力十分有限，需着重分析中小尺度系统的发生发展，并加密监测跟踪其动态，加强对雷达、卫星云图等多种实况资料的分析。

Abstract: Based on conventional meteorological observation data, regional automatic station data, Micaps data, Doppler weather radar data, FY-4A satellite cloud image data and EC numerical model forecast data, the process of rainstorm weather in Hengyang from April 25 to 26, 2022 was analyzed and studied, and the reasons for the large falling area, southerly range and deviation of rain band trend of the rainstorm process forecast were obtained. This process occurred under the control of the southwest jet stream, and the wind speed fluctuation on the jet stream axis caused warm-sector rainstorm, rather than the systematic precipitation forecasted by the model. When there were differences in the model forecast, EC numerical model forecast was still too trusted, which led to the deviation of the rainstorm forecast. At present, the numerical weather forecast model was very limited in the forecast ability of warm-sector rainstorm, so it was necessary to focus on the analysis of the occurrence and development of small and medium-scale systems, encrypted monitoring, and tracked its movements, and strengthened the analysis of various real data such as radar and satellite cloud images.