新疆区域模式MM5和GRAPES预报能力对比检验

Contrast Verification of Mesoscale Model MM5 and GRAPES of Xinjiang Region

对新疆气象局运行的MM5、GRAPES模式2008年4—9月的温度、降水预报能力进行了对比检验,得到以下结果:(1)MM5降水预报能力均优于GRAPES,08时初始场降水预报能力略优于20时初始场;(2)降水预报北疆西部、天山山区最好,北疆北部、北疆沿天山次之,南疆最次;(3)MM5对西西伯利亚低槽和中亚低值系统相结合的降水过程预报能力最好,中亚低值系统次之,西西伯利亚低槽系统最次;(4)MM5温度预报能力均优于GRAPES,白天的预报效果优于夜间,预报较实况总体偏低;(5)MM5气温预报准确率北疆优于南疆,偏东优于偏西,平均误差的分布则体现出偏西以负值为主,偏东以正值为主。GRAPES的预报准确率南北疆没有明显差异,平均误差的分布也体现出偏西以负值为主,偏东以正值为主。

The forecasting ability of Mesoscale Model MM5 and GRAPES to temperature and precipitation in Xinjiang during April to September 2008 was compared and verified. The result showed as follow： （ 1 ）MM5 has better ability to forecast the rainfall than GRAPES, 08 BTS data as initial value does better than 20 BTS, （2） the rainfall forecast ability is the best in Western Xinjiang and Tianshan Mountain area, second is Northern Xinjiang and the area along Tianshan mountain, Southern Xinjiang is the worst, （3）the rainfall forecast ability under the synoptic system of Siberia trough combined with mid-Asian low vortex is the best, then is that under mid-Asian low vortex, and the forecast ability under Siberia trough is the worst, （4） MM5 has better ability to forecast the temperature than GRAPES, the forecast efficiency for daytime is better than that for night, and forecast values are lower than real values in average, and （5） the ability of temperature forecast of MM5 model for Northern Xinjiang is better than that for Southern Xinjiang, Eastern Xinjiang is better than Western Xinjiang, GRAPES efficiency has not obvious difference in different area.