Thursday, January 22, 2009

An Omen to the West

After almost a week of summer-like days in Metro Denver, a change looms to the west. Pacific moisture is streaming into the State and a cold front is dropping from Canada; this combination will soon produce upslope snow west of the Divide, as evidenced by cloud formations above the Front Range.

A band of dark clouds had formed behind the snow-capped peaks this morning and, by this afternoon, most of these high summits were enveloped in "spill over" moisture. Meanwhile, on the Piedmont, downsloping winds persisted, bringing us partly cloudy skies and high temperatures near 70F. But by tomorrow, as the front sweeps to the southeast, we will be on its chilly side, with seasonable temperatures and intermittent showers (rain or snow).

Though the mountains have received significant snow this season, the East Slope is well below average. Then again, our heaviest snows fall in March and April, when Gulf moisture invades the Plains and the jet stream directs storms across southern Colorado. That is our upslope season!