Cool Air (2009)

August departed promptly, and took summer’s thick cloak of haze and humidity with it; September dawned cool, brilliantly clear, blue and bejeweled with dew. We have reached mid-September with the weather remaining modestly in character. I have lived in this area long enough to expect that eventual sucker-punch of debilitating, energy-sapping Indian summer, but keeping our fingers crossed, this weather is all we could hope for.

Riding weather, at last.

On cool clear nights such as these, the still air stratifies. This layering is not apparent to the eye, but it is obvious to an exposed rider. The gently rolling hills have their heads in a stratum of mild warm air but their feet in a pool of heavy frigid air—a difference of fifteen degrees from crest to trough. The visual cue I had not noted before was the highly local fog—“patchy fog” the weather people call it. Looking out across the piedmont from a high vantage point, the landscape is dotted with dozens of small smoking smudges. Each reveals the presence of a body of water—usually a man-made pond or lake, otherwise invisible, concealed by vegetation or terrain or sightlines.

Once I made the connection, I began to recognize the long low horizontal (and clearly artificial) line of a dam; set back from and above the road, the water was unseen. But these pools hold heat in their water, and when the air temperature suddenly drops, they work to reach their own equilibrium by driving water vapor into the air above them. This appears as fog, and in some places, it pours like a viscous fluid down a grade—following the flow of the cooler, heavier air—and out across the landscape. I rode through such a flow the other day, an eerie experience: like a spill of some inscrutable spongy mass, it rolled from a field down an embankment and across both lanes of the road. My head was above it, my body immersed in it; my passage roiled it into dissolution.

This morning I rode among tendrils of fog here and there, and the rising sun shone—from one moment to the next—first from below the plane of the fog, defining it as a ceiling; then from above the fog, making it the floor. Similar to flying through layers of clouds in an airplane, but on a more human scale.

The air has a taste and feel of its own, filled with liquid exhalations of the thousand flowers blooming in late summer exuberance, the goldenrod and ironweed, loosestrife and Joe-Pye weed, the late-passing Queen-Anne’s lace and countless other stems large and small whose riotous color spreads across the fields. Their days are numbered—these cool evenings but a prelude to the chill nights to come—the inevitable frost waiting just a few weeks out ahead of us. We will get all the blooming in that we can before that frost calls an end to our fun.