The Big Boom Theory

We are in the midst of the annual boom season.  It comes with hot weather every summer and causes a lot of consternation, conjecture, and conversation in the locals.  Along about midday, a boom or series of booms, sometimes loud and strong enough to shake windows, go off.  I'm so used to them now I hardly notice them anymore.  I think the sound comes from somewhere to the distant east, but sound travels funny up here so I could be wrong.  Some think they could be sonic jets taking off from some military airbase in Nevada, others wonder if they could come from a construction or quarry site.  Whatever it is, it is a yearly source of conversation on FB, especially among frightened newcomers.  My personal big boom theory is that it has something to do with weather and cloud formation.  Who knows.