有限区数值预报产品的强降水动力释用试验

The tests for heavy rain forecasting based on dynamical interpretation of NWP products

给出了利用有限区数值预报产品进行强降水动力释用预报试验的要点及试验结果。首先将模式开始运行后获得的最新观测资料(00—06GMT6小时降水量或雷达资料)输入计算机,并推算出相应的降水强度,再以降水强度公式近似计算其垂直速度,然后以有限区数值模式提供的风场、比湿场与垂直速度场来计算天气系统的移动及垂直速度的变化,以求出未来时刻的降水强度及6-24小时的降水量。

The major points on dynamical interpretation of NWP products are to put the observed 6-hour rainfall(≥10mm)into the formula calculating the intensity of precipitation and vertical velocity , and then the vertical velocity and the intensity of precipitation forecast given by the model are modified by the model products,u,v,Q and w,finally the rainfall is calculated,The heavy rain forecast in two ways,on grids(1°×1°) and at 435 stations.The verification shows that heavy rain forecasts by dynamical interpretation of NWP products are more or less better than that of the model forecasts for the category, 100mm rainfall. For the categories,25mm and 50mm rainfall,it is worse in August and better in September this year than that of the model forecasts.