Weather classification and Doppler radar characteristics of summer rainstorms in Yichang gap district

Based on radar mosaic products and regular observational data, the weather patterns of rainstorm in Yichang gap district of Hubei province in June and July of 2010-2012 are classified. The typical characteristics of radar echo under different weather types are analyzed, and five types of conceptual models of radar echo for heavy rain are created. The models include the tropical high edgeⅠmodel, the tropical high edge Ⅱ model, the trough moving eastwards model, the vortex and warm shear model and the depression model. (1) In the subtropical high edge model, the subtropical high approaches northward to Hubei Province and the radar echo band exhibits the direction from east to west or from northeast to southwest. In Ⅰ model, the strong radar echo lines from the south and north of Yichang join at Yichang gap district. In Ⅱ model, it is affected by strong radar echo moving eastward. (2)In the trough moving eastwards model, the subtropical high locates in the south of the Yangtze River. The radar echo band exhibits northeast-southwest in direction and the strong radar echo move eastward and influence the gap district in Yichang. (3)In the vortex and warm shear model, the subtropical high has the south-central position and weaker strength. The radar echo belt shows quasi east-west direction distribution, and strong radar echo occurs rarely. (4)In the depression model, the closed low pressure and transverse (inverted) trough occurs in Southwestern China or South China. The strong radar echo that is affected by the southeast flow of the closed low pressure moves continually northwestward. (5) In the subtropical high edge model and the trough moving eastwards model, the radar echo top and the vertically integrated liquid are high.