straw in the wind idiom UK
（预示某事的）迹象，征兆，风向标
something that suggests what might happen
She described the theatre's closure as "a straw in the wind" as companies faced up to the realities of life after the lottery. 她认为该剧院的关闭是一个信号，昭示着各家剧团终于放弃侥幸想法，开始面对现实了。