阜新地区冰雹短期潜势和短时预报方法研究

Study on Potential Forecasting and Short-time Nowcasting Models of Hailstone in Fuxin

利用阜新地区1977-2009年116个冰雹日相关数据,采用统计学、天气学和物理量计算等方法对降雹的时空分布规律、冰雹天气形势、冰雹短期潜势和短时预报模式进行研究,并对预报模型进行了试报验证。结果表明,(1)阜新地区冰雹的时空分布很不均匀,日变化特征明显,大部分发生在正午至傍晚(12:00-19:00),主要集中在14:00-17:00;其月变化特征显著,主要集中在5-9月,其中6月最多,7月次之;阜新的西北部和东北部是冰雹发生最多地区,中部为冰雹发生较多地区,西南部和东南部较少。(2)500hPa天气形势分析表明,阜新地区冰雹天气形势可归类为高空冷涡型、高空冷槽型、横槽型和西北气流型4个类型。(3)选取对冰雹天气具有明显物理意义的θse(850-500)、850hPa比湿、T850-500、U700-850、K指数5个预报因子,建立了阜新市夏季冰雹短期潜势和短时预报模式,并应用T639数值预报产品对2011年8月两次冰雹天气过程进行试报,试报结果准确。冰雹潜势预报和短时预报模型的应用,大大提高了冰雹预报的准确率。

The temporal evolution and spatial distribution features, weather situation and the potential forecasting and short- time nowcasting models of hailstone were studied, by using methods of mathematical statistics, synoptic meteorology and physical quantity calculating, based on 105 hailstorm data from 1977 to 2009 in Fuxin city, Liaoning province. The results showed that the temporal and spatial distribution of hailstone was not uniform. It occurred usually from the noon to the evening （12：00pm to 19：00pm） diurnal,mainly during 14：00 to 17：00. It occurred usually from May to September monthly, mainly in June and July. Besides, it occurred in northeast and northwest more than in southeast and southwest ,partly because of different land scape. According to weather situation of 500hPa, the hailstorm weather was divided into four types, namely cold - whorl, upper - groove, sidelong - groove and north - west airflow. The short- term tendency and prediction model was established by selecting five forecast factors, 0se（ss0-50o~, specific humidity at 850hPa, Ts50 500, U700-850 and K index, which had apparent physical significance to hail weather, and predicated successfully two hail weather process in August 2011, which indicated that the tendency and short - term prediction model improved the accuracy of hail forecast.