I feel like there's a phrase that people sometimes use in order to indicate that they have been aware of an impending change or event. The phrase draws on the metaphor of a soldier placing his ear to the ground to listen for faraway armies approaching. It's something like, "I have heard the ground tremors."
For instance, my coworker sent me an article about how JSON has almost fully supplanted XML as a data transmission standard. I have been picking up bits and pieces of knowledge on this shift over time, so I wanted to express that I was already aware of it. Thus, I wanted to say e.g., "Yeah, I've been hearing the ground tremors on that one for a while now."
I've googled the phrase and different variations of it so I could make sure I got it correct, but I can't find any evidence of its existence. Am I just making this up?