上海地区春季最高气温预报失败案例分析

摘要

Based on conventional surface and upper air observation data,the synoptic-scale circulation of the maximum 2 m temperature forecast failure in Shanghai during 17-18 March 2015 is analyzed.Using the real-time observations and numerical weather predictions,the causes of the forecast failure are investigated.The results show that the failure of the cloud cover forecast on 17 March was the main cause for the forecast failure.Meanwhile,the enhanced southeast winds further enlarged the forecast error.On 18 March,the misforecasted occurrence time of cold air advection into Shanghai mainly accounted for the forecast failure.The problems and recommendations in the forecast process were addressed,with the emphasis on the discrepancies between the real-time observations and the forecasts,forecast jumpiness and forecast uncertainty.Forecasters should have paid more attention to the real-time local and upstream observations,and different lead-time forecasts from different models.More important,operational ensemble forecasts in a probabilistic sense were highly recommended instead of traditional deterministic forecasts of a single model.Therefore,it is necessary to systematically assess the ensemble forecast performance,develop new application and interpretation of NWP products,and provide more products of multi-model ensemble forecasts with uncertainty information in public weather services.%本文分析了2015年3月17-18日上海地区连续两天发生最高气温预报失误的天气背景,并使用当日实况观测和业务预报使用的数值模式资料,剖析预报失败的原因,分析表明:对天空状况的误判是导致17日预报失败的主要原因,且东南风预报偏强更进一步增大了预报误差;冷空气影响时间的判断失误是导致18日预报失败的主要原因.从模式预报的实时检验、预报的跳跃性和不确定性角度分析了预报中存在的问题:预报员应重视本地和上游实况,从传统对单一确定性模式预报的依赖向多模式多起报时次及能提供概率预报和不确定性信息的业务集合预报的分析思路转型.此外,还需加强对集合预报的系统性检验、评估及数值预报释用产品的开发,增加包含不确定性信息的公众天气预报发布形式.