营口地区数值预报降水产品定量检验和预报指标研究

Study on quantitative test and forecast index of numerical forecast precipitation products in Yingkou region

选取2010年8月—2011年7月天气在线、日本传真图、美国全球预报系统(简称GFS)及T639等数值预报降水产品,采用统计学和天气学方法,按照预报时效、预报降水量级和影响系统等方面,对营口地区的降水预报产品进行检验分析,以更好的利用数值产品进行降水预报,提高营口地区的降水预报准确率。结果表明:从整体角度来看各种数值预报产品预报准确率随时间变化逐渐降低,但天气在线和GFS预报效果相对较好且稳定;日本传真图次之,T639稳定性最差;各种数值预报产品均存在预报偏小的情况,特别是对暴雨的预报效果均不理想,稳定性差,量级偏小;小雨量级降水空报和漏报明显;各种数值预报产品对高空槽和冷涡漏报较明显,主要为小雨量级。

Based on the numerical forecast precipitation products from the weather online, the Japan facsimile chart, the United States global forecast system （GFS） and the T639 during August of 2010 to July of 2011 ,precip- itation forecast products in Yingkou region were tested by a statistic method and a synoptic method in terms of forecast time validity, forecast precipitation intensity grades and influence system and so on in order to improve the accuracy of forecast. The results show that the accuracy rates of various numerical forecast products decrease gen- erally with the time, while the forecast effect from the weather online and the GFS is good and stable, then from the Japan facsimile chart. The stability of the T639 is the worst among all methods. The simulated value from the various numerical forecast products is lower than the observed value, especially for the heavy rain forecast with poor stability and small precipitation grade. There is obviously false alarm and failed forecast for light rain. There is failed forecast for the upper trough and cold vortex among all numerical forecast products, and most are in the light rain magnitude.