We left Columbia this morning in warm, humid air, the temperature already in the mid seventies. Heading west into Kansas, the south wind intensified and dark clouds loomed on the western horizon. While the larger, more powerful storms stayed to our north (closer to the center of low pressure) the trailing cold front was clearly marked by a line of dark clouds, stretching from the northeast to the southwest. We crossed the front beneath this swath (just east of Salina), enduring a brief period of rain.
West of the front, the air was noticeably cooler and drier. A mild northwest breeze replaced the southern gale and the sky was soon cloudless. Brilliant sunshine illuminated the fields of central and western Kansas before a second front approached from the northwest. Like a distant range of mountains, the clouds towered above the High Plains and, as we grew closer, their dark underbellies shrouded the sky. Heavy rains developed west of Flagler, Colorado, but, thankfully, there was not enough instability for high winds or hail to develop. North of Limon, beyond the Palmer Divide, the clouds dissipated and sunshine lit the high peaks of the Front Range.
As is typical with fast moving, western fronts, Denver received little precipitation. Pushing across the Rockies, these fronts create downsloping winds along the urban corridor, injecting warm, dry air into the area. This phenomenon keeps most of the rain out on the Eastern Plains, leaving only curtains of virga (precipitation that evaporates before hitting the ground) throughout the Front Range cities.
