【摘要】 根据甘肃省天水市7个气象站1971～2010年冰雹观测资料,分析了近40 a来该地冰雹变化规律。结果表明:天水市的冰雹分布特征呈现明显的日变化和年际变化。日分布以午后型(13～18时)为主,占全年降雹日数的49.1%;月际变化成单峰型,降雹时段集中在5～8月,占总日数的74.8%;年均累计降雹平均日数为6.4 d,降雹总日数呈逐年下降趋势。拔海高的地区冰雹发生较多,山区多于平川地区。影响天水市的冰雹路径大多呈西北—东南方向,降雹天气以西北气流型为主。更多还原

【Abstract】 Based on the hail observation data from 1971 to 2010 in seven weather stations which located in Tianshui of Gansu Province,the characteristic of hail variation was analyzed.The results showed that the hail distribution presented obvious daily and yearly variation,in a day,hail mainly occurred from 13:00 to 18:00,which was a percentage of 49.1 of the hail days in a year.And hail mainly occurred from May to August in a year,which was a percentage of 74.8 of hail days in a year.The annual average hail days were 6.4 d,and hail days presented decreasing trend year by year.Hail occurred more in higher elevation region and mountainous region.In Tianshui,hail weather was mainly northwest air pattern.更多还原