the cold winter wind had brought with it clouds so somber ,a

实际上是bring sth with it,这是把with状语提前了而已.
完成的句子是the cold winter wind had brought clouds with it.这里把with it提前,是因为后面的so somber是修饰clouds的,所以为了句子的简洁明了,提前了.
再问： 太给力了，你的回答已经完美的解决了我问题！