there's trouble brewing
There is difficulty, danger, or unrest fermenting or expected to arise in the future. According to many inside the region, there's trouble brewing among working-class voters who felt betrayed by the recent legislative change. We sensed that there was trouble brewing, so we got out of the bar before the fight broke out.
there’s ˈtrouble brewing
(informal) a difficult situation is starting to develop: There’s trouble brewing in the car industry.