The river goes quiet right before it breaks

Last night I dreamed I was standing in the middle of the river, but the water wasn't moving — it just hung there, like the whole current had taken a breath. The banks were still there, the sound of the falls behind me, but everything in front had gone glassy and silent. I've felt that pause in real life, right before a storm comes over the ridge, and I've never been able to say what it is. In the dream I knew the answer was in the water, but I woke up before I could read it.