GRAPES_Meso V3.0模式预报效果检验

Verification of GRAPES_Meso V3.0 Model Forecast Results

应用国家气象中心模式检验方法对GRAPES_Meso V3.0模式2008年2月-2009年3月的试验预报产品,如降水、中低层高度、温度和风场预报进行统计检验。检验结果表明:V3.0模式降水预报性能得到明显改善,年及四季平均的各级降水TS评分显著提高,除了秋、冬季的48h中雨和暴雨预报外,TS评分明显高于V2.5模式,但V3.0模式的预报偏差偏大,中雨以上偏大更明显。从预报的季节平均降水率分布来看,对秋、冬季我国东部24h降水预报偏小改进明显,对春、夏季强降水中心位置及强度预报也好于V2.5模式,但是48h降水预报明显偏大,逐日降水率演变图也印证了这一点。此外,V3.0模式对500hPa高度和风场及48h预报的850hPa风场和温度场改进显著,对于850hPa高度和温度的24h预报,除夏季外,其他季节预报效果优于业务模式。

The rainfall,temperature,height and wind forecast products of GRAPES_Mesc model（V3.0）, which is mesoscale model of the new generation multiple-time-scale numerical weather prediction system, are verified by operational statistical verification methods from March 2008 to February 2009.Dichotomous and continuous forecast verification methods for deterministic forecast model recommended by World Meteorological Organization or Chinese Meteorological Administration are employed.The verification results show the rainfall forecast of V3.0 model is better than V2.5 model.The annual mean TS of rainfall forecast is improved for all five grades and is higher than that of V2.5 model clearly for four seasons mean,all months mean of a year,except for 48-hour moderate rain and storm rain of autumn and winter.The forecasted rainfall of V3.0 model is mainly greater than observed rainfall,especially for moderate to heavy rain.The simulated distribution of the season mean raining rate is much more similar to the observed patterns. For the 24-hour forecast of eastern China in autumn and winter,rainfall is almost no longer underestimated. The forecast performance of location and intensity of strong rainfall center for spring and summer has also been improved,but the amount of 48-hour rainfall is obviously overestimated comparing to observation,shown clearly through the figures of daily mean rain rate time series.Meanwhile,the developing trend and intensity forecast of strong rainfall processes is better than that of V2.5 model for most time of the year.The height,temperature and wind forecasts of the upper prognostic forecast have made remarkable progresses especially for 500 hPa height forecast,500 hPa wind forecast,and 48-hour 850 hPa wind forecast.However,the forecast of 24-hour low level temperature and height in summer are hardly improved,so the model still need more progresses especially in rainy season.For other seasons,the forecast of temperature and wind in low level atmosphere is fairly good.