关键词: 油茶, 油茶, 嫁接苗, 施氮浓度

Abstract: In order to provide effective weather forecast service for the agricultural production to prevent hail and reduce disaster losses and do the hail weather forecast well. Five typical strong convective weather processes in 2013 had been comparison and analysis in this paper by using various meteorological observation data. The results show that: (1) The hail occurred under advantageous synoptic background such as high volatile energy, big humidity and strong lifting condition. The large-scale forced uplift, lower meso-scale dew point front, and the ground convergence line were provided the trigger conditions for the strong convection weather. (2) The hail easily happened in the case of SI having decreased obviously, Ki (K index), the temperature difference between 850 hPa and 500 hPa and CAPE increased obviously in the afternoon, meanwhile having the large vertical wind shear, and also the height of 0℃ and -20℃ layer at about 600 hPa and 400 hPa respectively. In addition, bigger humidity was accompanied by short-time strong rainfall weather and strong airflow was often accompanied by thunderstorm and wind. (3) The hail usually occurred when the convective clouds reached maturity, in the southeast of the maximum gradient of TBB (Black Body Temperature) contour, and in the convective cells of the maximum radar reflectivity factor was bigger than 55 dBZ. (4) If the temperature in the ground occurred abnormal changes, at the same time, there were bigger pressure gradient, clockwise rotation of wind direction, and wind speed extreme, it can be considered as a signal before the strong convective weather happened.