河南濮阳局地大暴雨成因分析

利用常规观测资料和新一代天气雷达产品,对2012年7月9日河南濮阳地区局地大暴雨天气进行分析。结果表明,此次局地大暴雨天气是在副高稳定,稍有西伸北抬,高空有低槽东移,弱冷空气扩散南下,中低层有低涡、切变线、低空急流、地面倒槽、中尺度低压的相互作用下产生的;水汽充沛、湿层深厚,为暴雨区提供了水汽条件。暖云层厚度较厚,大于4 km,有利于高降水效率的产生;多个中尺度对流雨团先后经过同一地点,产生的"列车效应",提高了降水效率;低空急流和超低空急流的形成,在水汽输送和聚集过程中发挥了重要作用。利用探空曲线中CAPE值的变化情况来判断上升运动的强弱,具有较好的指导意义;利用多普勒雷达产品可以较好地预报强天气路径、强度及影响范围。

Analysis on Local Rainstorm in Puyang City, Henan Province

Based on the conventional observation data and the new generation of Doppler radar data, the heavy rainfall on July 9, 2012 in Puyang City, Henan Province was analyzed. The results showed that the local heavy rainfall in Puyang is caused by the stable subtropical high, which is stretching toward the northwest slightly and the low trough of upper air＇ s eastward-moving combining with the southern weak cold air, vortex in the mid-low troposphere, shear line, low level jet, ground inverted trough and the mesoscale depression. In this process the water vapor is abundant, wet layer is deep. The warm clouds＇ thickness is more than 4 km which is helpful to high precipitation efficiency. Several mesoseale convective rain groups go through the same place successively which caused the ＂train effect＂, improving the efficiency of precipitation. The low-level jet and the ultra-low-level jet stream played an important role in the process of water vapor transport and accumulation. Using the changes of the CAPE value in the stratification curve, the strength of the upward movement was judged, which has a good guidance meaning. Using Doppler radar products can forecast the strong weather oath, the intensity and scooe of influence well.