Sunday, May 15, 2011

March in Mid May

I left Columbia this morning in a chilly mist; a steady northwest wind and low, gray clouds made the temperature feel even colder than the official report of 41 degrees F. Heading west on I-70, the drizzle resolved within thirty miles but cloudy skies, a north wind and cool temperatures persisted all the way to Denver. While the green landscape looked like mid May, it felt more like March.

The unseasonable chill seemed to have an effect on wildlife as well. The usual roadside insectivores, including kingbirds, barn swallows and scissor-tailed flycathers, often common along the highway, were rarely seen, having likely retreated to sheltered wetlands where the wind and cool air would have less impact on their prey. Only the hardy vultures and hawks were well represented, benefitting from plenty of roadkill and industrious rodents stirred by the chilly weather.

While the drizzle was a backside gift of the latest storm system, which is still creeping toward the East Coast, high pressure over south-central Canada is the culpret when it comes to the unseasonable chill. Sending a flow of crisp air from the Canadian Prairie, this dome has dropped down behind the advancing storm front and, so far, is winning the battle with a dome of warm air over the Southern Plains. While the extensive cloud cover indicates that mixing is occuring in middle layers of the atmosphere, the more dense cold air is knifing in below any warm, buoyant air at the surface. Once this cold high pressure moves further to the east, its clockwise flow will open the door to recovery from the south.