presage
To be a sign that something will happen soon.
To presage something means to be a sign or warning that it will happen soon. Dark clouds gathering on the horizon presage a coming storm. When your dog starts acting nervous and won't settle down, it might presage an earthquake that you can't feel yet but she can sense. When a friend suddenly gets quiet and withdrawn, it could presage that something is bothering them.
Today we use presage mostly for real signs based on cause and effect, not superstition. A string of small earthquakes might presage a larger one. A company's declining sales presage possible layoffs.
You can also use presage as a noun: a presage is the sign itself. “The eerie silence was a presage of the hurricane's arrival.”
The word carries a sense of foreboding or seriousness. You wouldn't say someone's smile presages a good day, you'd just say it suggests one. But you might say that rising tension between two friends presages an argument, or that excellent practice sessions presage victory in the championship game.