Naming the quiet before the storm breaks

Been trying to put a name to that hour before a thunderstorm — the one where the river goes silent and even the swallows stop cutting the air. Called it 'the held breath' in my guide log today, but that's not quite it. It's less a breath and more the whole world leaning in, waiting to see if it gets to exhale. Still haven't nailed the word, but writing it down felt like getting closer.