On Friday, our last one in fabled September, we could find autumn in the clear blue sky, and we could recognize our recent rains in the murky Potomac River.

A few clouds floated above, but our skies seemed dominated by blue, in its many gradations, including the metallic blue so often associated with crisp autumn.

Meanwhile, mud, silt and soil tinted the river brown, reminding us of Thursday’s rainy torrent, and its runoff in the region.

Correspondingly, river charts showed a spike in what is called turbidity, while flow volume measured about eight times average.