Tuesday, May 5, 2015

Trapped in a Trough

Over the past week, an atmospheric trough has enveloped the Front Range region and much of the Intermountain West.  Reinforced by a series of cold fronts, this dip in the jet stream has spread cool, cloudy, wet weather from the High Plains to the Pacific Northwest.

Low pressure centers, developing along the eastern edge of the trough, have swept Gulf moisture northward through the Heartland, igniting severe thunderstorms across the Plains and producing an upslope flow along the Front Range.  The latter, while studded with strong thunderstorms at times, has primarily brought overcast skies, cool temperatures and pockets of heavy rain.  This pattern, which is expected to persist through the coming weekend, is more reminiscent of the Pacific Northwest than the sunny, semiarid climate of the Front Range.

While this chilly, damp weather may not be ideal for outdoor activity, it is fueling the verdant growth of spring and, for now, eliminating the need for artificial irrigation.  In a dry region that, long ago, outgrew its water supply, any precipitation is more than welcome.