Tuesday, May 19, 2015

A Relentless Upslope

Over the past two weeks, a series of Pacific storm systems has produced a nearly continuous period of upslope flow along the Colorado Front Range.  Counterclockwise winds generated by low pressure centers and clockwise flow within atmospheric troughs have directed Gulf of Mexico moisture toward the Rocky Mountain corridor; rising with the terrain, the air cools and condenses, producing overcast skies, chilly temperatures and intermittent rain or snow (depending on elevation).

Indeed, it has felt more like March than May.  Though the greenery is especially lush for this semiarid landscape, the chill has slowed the leafing and flowering process for many trees and shrubs.  Despite flooding along the South Platte and its tributaries, the mountain snowpack has continued to build, threatening even greater runoff when seasonal warming resumes.

In a region renowned for sunny skies and dry air, it's hard to accept such a relentless period of chilly, damp weather.  Though the precipitation will be beneficial in the long run, most of us would prefer the usual pattern of clear, mild days and late afternoon thunderstorms.  After all, Colorado without sunshine just doesn't seem right (unless, of course, it's snowing).