汛期大～暴雨的降水概率预报模式

应用阶梯函数变换预报因子 ,经过相关比筛选 ,进行 REEP构造分量级降水概率预报方程 ,应用不同时刻资料和对 NWP产品统计释用方法构造分时刻预报方程 ,并对其预报结果进行了综合的集合预报。实用表明 ,预报模式对大～暴雨的概率具有一定的预报能力。

A Probability Forecast Model of Heavy Rainfall in Rainy Season

A probability forecast model of heavy rainfall was constructed by developing probability of precipitation amount (PoPA) and based on probability of moderate precipitation.Step function based on estimating POP in suitable intervals more accurately describs nonlinear probability distribution and closely relates to probability of heavy rainfall.By using predictors transformed into step function and estimating correlation ratio between predictors and heavy rainfall event,the regression estimation of event probabilities (REEP) of PoPA was completed.By using multi time data and NWP products,multi time predictive equations were constructed,and an ensemble prediction that synthesized multi time predictions improved forecast effect.Forecasting tests indicate that the probability forecast model of heavy rainfall is efficacious.