关键词: 武汉市, 冰雪天气, 逆温, 冷垫, 大气斜压性, 暴雪

Abstract: Based on the meteorological observation data in Wuhan and reanalysis data from NCEP, four snow-ice weather processes at the early stage of 2008 were analyzed. The results show that inverse temperature from 700 hPa to 850 hPa and cold air cushion below 850 hPa both are favorable conditions to snow weather. Wind shear line on 700 hPa locates in the north of that on 850 hPa. Vertical shear of wind indicates that atmosphere is of obvious barocliny. Southwestern air current at higher level transports large amounts of warm and moist air over cold cushion at lower levels. Snowstorm happens from 20:00 on 18th January to 20:00 on 19th January in Wuhan, and it has been found that occurrence of snowstorm requires strong upward motion, large southwestern water vapor transportation and water vapor convergence. The greatest water vapor transportation and water vapor convergence of snowstorm are generally higher than that of rainstorms. Inertial instability at high level and convective instability at middle level both are favorable conditions to the occurrence of snowstorm.