关键词: 大连地区, 暴雪天气, 雷达回波

Abstract: Based on the winter precipitation data at 7 weather stations, the conventionally observational data and the new generation weather radar (CINRAD/SC) data in Dalian from 2001 to 2010, the circulation situations of 8 snowstorm cases occurred during  this period and their radar echoes characteristics were analyzed. The results indicate that the synoptic situation causing snowstorm is related to upper trough formed over north China and stretching towards Huanghuai area before the formation of East Asia trough in 500 hPa. Accordingly, it is related to the eastward or north cyclone (inverted trough) from the south of north China and Jianghuai (Huanghuai) areas and the encounter with southward cold high in Dalian on surface level. The “warm-shear” type is the most in radial velocity field of radar echo and its precipitation intensity increases with the increasing of south and north branches airflows and wind shear, the lifting of shear layer at boundary layer and lower troposphere as well as the occurrence of warm advection, while it decreases with the weakening of southwest airflow at boundary layer and lower troposphere, and the occurrence of cold advection. This study could provide references for snowstorm forecast.

Key words: Dalian area, Snowstorm weather, Radar echo