During the winter months, most Americans in the central and eastern U.S. dread Alberta Clippers, those pockets of frigid, Arctic air that plummet southeastward to reinforce the seasonal chill. Over the past 36 hours, we have enjoyed the summer equivalent of those clippers; a trough of cool, Canadian air has dipped across the Midwest, pushing the hot, humid air of late June to the south and east.
Unlike the winter invasion, this Summer Clipper is a welcome reprieve, bringing drier air with highs in the upper 70s to low 80s. Unfortunately, like its winter cousin, its effects will be short-lived as the atmospheric trough moves rapidly off to the east and conditions moderate. Indeed, our next heat wave will develop over the coming days, sweeping the thick air of summer back into the Heartland.
While weather patterns are more stable in winter and summer than they are in the spring and fall, the jet stream is a fickle beast and sudden shifts in its course trigger these Canadian invasions. Depending on the season and on our personal perspective, they may be viewed as gifts or as unwelcome intrusions.
