An Unexpected Gift

Just after 7:30 this morning, strong northeast winds raked Metro Denver, dropping the temperature by ten degrees (F) or more.  In the midst of our early summer heatwave, the chilly air is more than welcome.

The cause for this sudden change is an atmospheric trough, a dip in the jet stream that has been separating hot air to its south from cool air to its north.  High pressure over Montana has temporarily won out over the hot, high pressure ridge of the Desert Southwest.  In concert, our warm, southwesterly winds have temporarily shifted from the northeast, producing an upslope flow along the northern Front Range; while the temperature in Denver is in the 60s F this morning, it is 82 degrees in Colorado Springs (south of the Palmer Divide).

Our chilly atmospheric respite is expected to be brief and hot air is forecast to return by tomorrow.  Then again, this morning's rapid change was unexpected and the whimsical nature of the jet stream is hard to predict.  In the meantime, we'll enjoy the natural air conditioning.