关键词: 冻雨, 高低空环流, 中层暖层结构, 西南气流, 增温

Abstract: Based on 1° × 1° global data assimilation system (GDAS) data from NCEP, 2.5° × 2.5° global grid data from NOAA and meteorological observational data, the weather process of freezing rain on February 24, 2010 in Shenyang region was analyzed. The results show that obvious warming prior to the freezing rain is the important reason causing freezing rain disaster in Shenyang region. Warm and deep layer between 925 hPa and 750 hPa in which temperature is equal or greater than 0 ℃ is the necessary condition for the formation of freezing rain. Southwest airflow contributes to the transmission of warm and moist air to the northeast region, and it could determine the range of freezing disaster occurrence. The time of establishment and destruction of warm and deep middle layer is indicative to forecast of freezing rain.