2013年北京地区一次强对流冰雹天气过程分析

2013年6月11日08时至6月12日08时,北京地区出现了一次强对流天气过程,部分站点出现冰雹、短时强降水等灾害性天气。本文详细分析此次过程的大尺度天气环流背景、物理量场、北京S波段新一代天气雷达基本反射率因子、径向速度、一小时累积雨量等产品和海淀风廓线探测数据、5分钟加密自动站数据,得出如下结论：(1)本次过程主要是对流层中层温度槽落后于高度槽,系统斜压性较强,发展较好。(2)源于东部沿海的暖湿空气持续输送,为后续强对流天气提供了充沛的水汽和不稳定能量。(3)本站不稳定能量的积聚为对流性天气的形成发展提供了良好的触发维持条件。(4)怀柔汤河口降雹之前,多普勒天气雷达速度图上反映出明显的中气旋特征；反射率因子图存在钩状回波,相应的垂直剖面具有回波悬垂、三体散射等特征。(5)南风分量明显加大,有利于水汽的输送,中尺度切变线的存在有利于气流辐合,强回波稳定少动,产生短时强降水。

Analysis of One Severe Convective Weather Process with Hail in 2013 in Beijing

An severe convective weather along with hail ,short term heavy rain occurred in Beijing from 08:00 June 11, 2013 to 08:00 June 12, 2013 , Synoptic scale environment conditions, physics parameters fields, Doppler radar base reflectivity, velocity and one hour precipitation, wind profile and 5-minutes intensified automatic surface weather observation system data are analyzed. Results show that, 1)Temper tough lagging behind height tough over the baroclinic zone in the troposphere is favorable to system developing;2) Warm moist air continuous transportation from east coast supplied adequate water vapor and unstable energy;3)The accumulation of unstable energy is trigger and sustainable condition for severe convection weather;4)There are some typical characters before hail falling in Tanghekou station, Huairou, such as mesocyclone shown in radar velocity, hook echo shown in radar reflectivity, and echo pendency and three-body scatter spike shown in corresponding vertical cross-section;5) The south wind components becoming obviously was beneficial to water vapor transportation. The existence of mesoscale shear line is favorable to air stream convergence. Strong echo maintained and stilled is helpful to short term heavy rain.