This is a heads up that it is coming.这里的heads up是名词"提醒,预示"的意思.
句子意思:这预示/意味着它即将到来.
heads-up 【口】机警的
I’m just giving you a heads up.
我只给你提个醒.
埋头苦干
I have a small office,and usually have my door open.But I keep my door closed for telephone calls and heads down time.（我有个小办公室,平常门是开的.但是要打电话和埋头工作的时候,我就会关上门）