Analysis of the Climate Features and Radar Echo of the Hail Weather in Pingliang of Gansu Province

Based on the hail observation data from seven stations in Pingliang of Gansu Province from 1965 to 2011,the temporal and spatial distribution of hail weathers and its climate features in Pingliang were analyzed in detail.At the same time,the stratification feature and radar echo characteristics were analyzed by using the hail observation data and the sounding data in hail days from 2003 to 2011,and Doppler radar data of thunder cloud in Pingliang from 2009 to 2011.The results show that the high risk area of hail weather was located in Huating,Zhuanglang and Kongtong of Pingliang area.Hail weather occurred frequently in the 1980s and reduced from the 1990s.In a day,hail mainly occurred from 17:00 to 22:00.The instability of the upper troposphere(from 300 to 600 hPa) is the main characteristic of hail weather in Pingliang.Echo intensity of hail cloud in Pingliang was more than 50 dBZ,echo top height was more than 8 km,vertical liquid water content was 20 kg.m-2,strong center average height was about 6 km,the 45 dBZ echo height was 2 km higher than the height of 0 ℃ layer.