午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

The macroscopic conditions for the formation of hail clouds are discussed through analyzing the patterns, thermal and hygrometric stratification conditions and local features of mesoscale influencing systems occurred in severe hail days from 1980 to 2000 in the Beijing area. The features of the different influencing systems and their hail shooting characteristics are described. It is found out that the macroscopic formation conditions, source areas and moving tracks for hail clouds have obvious local features. The influencing systems of hail events in Beijing include such weather patterns as Low Trough Cold Front, Mongolia Vortex, Northwest Flow, and Northeast Vortex, within which the Low Trough Cold Front gives the greatest chance for hail shooting and the Northeast Vortex the least.