摘要
基于乌鲁木齐区域数值预报业务系统,运用Ts和Bias评分方法,对2012年9月1日—2015年8月31日逐日2个起报时次的逐6 h累积降水量的年与季节预报性能进行检验,并从空间上分析了2015年全疆站点逐6 h累积降水量在4个预报时段的评分特征。结果表明:(1)2个起报时次的降水评分相差较小,00 UTC起报略优于12 UTC起报,2015年系统改进了白天大量级降水的空报现象。(2)系统对晴雨预报较为准确,Bias接近1,空报、漏报率很小;随着降水阈值的升高,Ts评分减小,Bias变幅增大,空、漏报率也随之增加。系统对强降水过程以漏报为主。(3)系统的降水预报能力存在季节差异,夏季Ts评分最高,秋季次之,冬季最小;随时间模式对四季降水预报能力均有提高,降低了冬季大量级降水的漏报率和夏季大量级降水的空报率。(4)在新疆地区,08—14 BT(Beijing Time)、14—20 BT、20—次日02 BT空报站点数多于漏报,14—20 BT空报率最高;在02—08 BT整体呈漏报。(5)各站点整体来看,白天Ts评分高于夜间,山区及邻近地区评分高于平原地区;西天山评分略优于东天山,夜间晴雨预报有天山北坡漏报、南坡空报的趋势。
Based on the Regional Numerical Forecasting System in Urumqi, the annual and seasonal precipitation predictability of this system is evaluated, using the Threat Score and Bias Score of 6 h accumulated rainfall at two initialized times in one day from 1 September 2012 to 31 August 2015. Additionally, the spatial distribution of site＇s 6 h accumulated rainfall forecast skill is analyzed in four forecast periods. The results indicate that ： （ 1 ）The prediction performance of two initialized times is quite similar, although the performance at 12 UTC is slightly better than 00 UTC. The false alarm ratio of heavy rainfall during daytime is improved in 2015. （2）The probability of rain forecast is very accurate. The Bias score is close to 1 with small false alarm ratio and missed event ratio. Threat Score decreases and variation amplitude of Bias Score increases with the threshold value of rainfall increases. And it means that the false alarm ratio and missed event ratio will increase. What＇s more, most heavy rainfall events are missed. （3） There are seasonal variations in rainfall forecast, which is greatest in smnmer, secondary in autumn, and the least in winter. The performance of precipitation forecast in every season is increased with time. Meanwhile, the missed event ratio of heavy rainfall in winter and the false alarm ratio of heavy in summer are both reduced with time. （4） In Xinjiang, the false alarm sites are more than the missed event sites from 8：00 to 14：00 BT （Beijing Time）, 14：00 to 20：00 BT and 20：00 to 2：00 BT. The false alarm ratio is the highest in period from 14：00 to 20：00 BT, and the rain is missed as a whole from 2：00 to 8：00 BT. （5）The threat score during the daytime is higher than that in nighttime. Additionally, the precipitation predictability in mountain and the surrounding areas is generally better than that in the plain area. The forecast performance of Western Tianshan Mountain is slightly better than that of Eastern Tianshan Mountain, and
作者
杜娟
于晓晶
辛渝
李曼
马玉芬
DU Juan YU Xiaojing XIN Yu LI Man MA Yufen(Institute of Desert Meteorology, China Meteorological Administration, Urumqi 830002, China Center of Central Asia Atmospheric Science Research, Urumqi 830002, China)
出处
《沙漠与绿洲气象》
2016年第6期31-40,共10页
Desert and Oasis Meteorology
基金
新疆气象局面上基金"卫星资料同化对新疆土壤温湿度预报的影响研究"
中央级公益性科研院所基本科研业务费项目(IDM201301)共同资助
关键词
区域数值预报系统
6
h降水预报
TS评分
Bias评分
空间检验
regional numerical forecasting system
6 h precipitation forecasts
Threat Score
Bias Score
spatial statistic test
