Why is the weather forecast reported to Harbin after Beijing?

The first appearance is the capital Beijing, which is naturally understandable. Generally, the weather forecast of provincial TV stations is the first in the provincial capital, and it is broadcast twice before and after, as is the case in various cities, which is convenient for people who miss the weather forecast in Beijing. Then Harbin, Changchun, Shenyang, Tianjin and Hohhot. Act II: Urumqi, Yinchuan, Xining, Lanzhou and Xi 'an. Act III: Lhasa, Chengdu, Chongqing, Guiyang and Kunming. Act IV: Taiyuan, Shijiazhuang, Jinan, Zhengzhou, Hefei, Nanjing and Shanghai. Act V: Wuhan, Changsha, Nanchang, Hangzhou, Fuzhou and Taipei. It seems that it is not the first scene divided from northeast, north, northwest and southwest: northeast+Beijing, Tianjin and Hohhot; Northwest China; Southwest China; North China+North Central+Zhengzhou; Central China+Central South; It is too complicated to divide South China in this way, so it seems to be based on the latitude and longitude lines on the regional map in the upper right corner of the TV. So: Line A is about 109 E, Line B is about 34 N, Line C is about 39 N, Line D is about 3 1 N, and Line E is about 23 N (I guess at random). Divided into six blocks and then analyzed from the city, it still inherits the north-south and east-west broadcasting modes.