I knew what it was before I saw it. I knew it from the jaded commuters standing slack-jawed outside the Metro station, then grabbing their phones and snapping away. I knew that on this October Tuesday, our gray day of rain was being rewarded with a rainbow. And not just any rainbow — but a complete arch that spanned all of Route 66.

The rainbow was spotted in other parts of the region, too. I have a reliable rainbow-sighting report from Reagan National Airport, though no pots of gold were found.

The longer I looked at the rainbow the more the colors revealed themselves. At one point there was even a double bow.

What heartened me most were the rainbow-spotters themselves. Not much will slow commuters from reaching home in the evening, but the rainbow was doing just that. I snapped half a dozen shots of the heavens on my way to the car … and I wasn’t the only one.