开封市近30年强对流天气变化及环流形势特征

利用1981—2010年开封地区五个地面观测站观测资料,对强对流天气包括短历时强降雨、雷雨大风、冰雹、龙卷的气候特征进行统计分析.结果表明:强对流天气出现次数由多到少依次为短历时强降雨、雷雨大风、冰雹、龙卷.开封短历时强降雨自西南到东北逐渐增加,一年中主要出现在4—9月,7、8月为短历时强降雨多发期,极值出现在1996年7月26日开封站,雨量为170.7 mm/h.雷雨大风西部多,东部少,一般出现在每年的春季到夏季,6—7月为雷雨大风高发期.冰雹北部多,南部少,除了冬季外,其他季节均会出现,4—7月为冰雹的多发期.开封龙卷的发生为小概率事件,有记录的龙卷风只有2次,分别出现在春季和夏季.

Strong Convective Weather Changes and Circulation Pattern Features in Kaifeng in Recent 30 Years

Using five ground stations observation datas of Kaifeng from 1981 to 2010,the climatic characteristics of severe convective weathers,including short-time hard rain,thunderstorms and strong winds,hail,tornadoes have been analyzed.The results show that the order of occurrences from more to less is as follows：short-time hard rain,thunderstorms and strong winds,hail,and tornadoes.The short-time hard rain in Kaifeng gradually increased from the southwest to the northeast,mainly appearing in April to September.The frequent period of short-time heavy rainfall often occurs in July and August,and the short-term precipitation maximum of Kaifeng occurring on July 26,1996,is 170.7 mm.Thunderstorms and strong winds which usually appear in late spring to summer each year occurred in the western most,and followed by the eastern.And thunderstorms and strong mainly appear in June and July.Hail fall times in the northern are more than those in the southern.Except winter,hailin other seasons can appear.And hail often occurs in April to July.The occurrence of tornadoes in Kaifeng is small probability event the recorded is only twice appearing participly in spring and summer.