天気予報によれば今夜は雪になるそうだ。
tbd
According to the weather report, it'll snow tonight.
According to the weather report, it will snow tonight.
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题;表示与另一选项(无论是否明确提及)形成对比;表示强调