1. Hebei Provincial Institute of Meteorological Sciences, Shijiazhuang 050021, China
2. Key Laboratory of Meteorology and Ecological Environment of Hebei Province, Shijiazhuang 050021, China
3. National Meteorological Center, Beijing 100081, China
4. Hengshui Meteorological Bureau, Hengshui 053000, China
5. Raoyang National Climatological Observatory, Hengshui 053900, China
6. Qinhuangdao Meteorological Bureau, Qinhuangdao 066000, China