雷达反演潜热在华南区域数值模式汛期短时临近降水预报的应用试验

为了评估潜热对短临降水预报的影响，基于雷达反演潜热的基础上，以2014年3月30日的强降水个例和2013年5月的31天为样本，进行了初值有无引入潜热释放引起位温增量的批量试验。(1)强降水个例模拟试验发现，初值引进潜热后预报的12 h累积降水中心与实况一致，预报的前4 h雷达反射率从范围、强度上更接近观测的反射率，逐小时TS比无潜热试验要高。(2)诊断分析表明模式初值引进潜热后，调整降水区域上空大气的温度结构，订正或加强次级环流，触发对流不稳定能量释放，利于成云致雨。(3)批量对比试验反映初值潜热对前12 h逐时降水预报一直保持正影响。 

APPLICATION EXPERIMENT OF LATENT HEAT RETRIEVED FROM RADAR ON SHORT-RANGE FORECASTING IN RAINY SEASON USING REGIONAL NUMERICAL MODEL OVER SOUTHERN CHINA

Based on latent heat retrieved from radar reflectivity, comparison experiments of initial condition with and without nudging potential temperature increment due to latent heat are conducted for a case of heavy rain process that occurred on 30 march 2015 as well as for the 31 days of May 2013 to estimate the impact of latent heat on short-range precipitation forecast. The results are as follows. (1) The location of maximum center for predicting 12-hour accumulated precipitation is well reproduced with nudging latent heat, while the location of maximum center without nudging latent heat is far northward from the observed one. The hourly forecast reflectivity 4 hours ahead is close to the observed reflectivity in terms of area and intensity, and hourly TS (threat score) is higher than that without nudging latent heat. (2) Diagnosis analysis shows that nudging of latent heat at initial time could adjust the thermal structure of atmosphere in convective area, revising or enhancing the intensity of local secondary circulation, triggering the release of instable energy and being beneficial to the production of precipitation.(3) Analysis of batch experiments indicates that the initial condition with nudging latent heat has significant impact on hourly forecast in the first 12 hours.