新疆DOGRAFS_3km夏季预报试验与分析

为了提升新疆区域数值天气预报模式的精细化预报能力,基于目前业务应用的沙漠绿洲戈壁区域同化预报系统(Desert Oasis Gobi Regional Assimilation Forecast System,简称DOGRAFS),搭建了DOGRAFS_3 km运行系统,将2016年7月作为预报检验月份,对比分析了目前业务化运行的DOGRAFS_9 km与新搭建的DOGRAFS_3 km系统的短期、短临预报效果,并针对7月31日—8月2日的降水过程进行对比。结果表明:(1)3 km分辨率系统的地面温度、风基本气象要素的预报效果整体要优于9 km系统;(2)从不同层次上的位势高度、温度、风要素预报结果看,3 km系统在925、850、700、500 h Pa预报效果优于9 km系统,300 h Pa和200 h Pa略差于9 km系统;(3)降水检验看,3 km分辨率系统在降水时段、落区和量级等方面的效果均好于9 km系统,尤其是对中量和大量级降水的预报,3 km分辨率系统与9 km系统的降水预报能力均有限。(4)通过用加密自动站的降水量监测值检验分析得知,对于典型降水过程的的过程降水落区、24 h降水落区、以及6 h降水落区的预报,3 km分辨率系统的预报效果更好。综合2016年夏季代表月份的预报以及一次强降水过程的对比分析结果,DOGRAFS_3 km系统在夏季的整体预报性能优于DOGRAFS_9 km,推进DOGRAFS_3 km高分辨率系统建设尤为必要。

The effect of DOGRAFS_3km on the forecast effect of meteorological elements in Xinjiang during summer

Based on the forecasts of Desert Oasis Gobi Regional Assimilation Forecast System DOGRAFS, the 3km-resolution was constructed. The results of the forecast in July 2016 were verified and evaluated by the objective verification method and a precipitation incident was analyzed. The results showed that:(1) DOGRAFS system with 3km-resolution had stable forecast performance and could provide good forecast reference;(2)According to the verification scores of sounding and surface observations, 3km-resolution forecast were better than that of 9km-resolution; especially in the upper air of the middle and lower levels, the 3km had obvious advantages;(3)According to the verification scores of precipitation forecast,3km-resolution one could forecast the precipitation period, location and intensity better, especially for the mediun and large-scale precipitation, but 3km-resolution system had limited capability to forecast precipitation;(4)According to the typical precipitation case range, falling area forecast, site precipitation forecast and precipitation verification scores, 3km -resolution was better for this precipitation forecast.