山区阵风可达7级左右，门头沟区发布大风蓝色预警

Group 1 - The article discusses a blue wind warning issued for the Mentougou District of Beijing due to cold air, predicting a north wind of around level 3 and gusts in mountainous areas reaching level 7 on January 26 [1][2] - The warning was officially released by the Beijing Meteorological Bureau, emphasizing the need for precautionary measures [2] - The warning was signed by Shi Chen, indicating the authority behind the alert [2]