Snow, being bright white, reflects most sunlight right back into space. Elsewhere, darker vegetation and soil absorbs the sun's heat, which then warms the layer of air near ground level. Also, in a process called sensible heat transfer , the snow itself directly absorbs heat from any warmer air which occurs just above it, cooling the air down toward the temperature of the top of the snow, and warming the snow. This is how the snow melted along the edge of the band, shrinking it throughout the day, while keeping the air above it relatively cold. There are also areas of snow in eastern Colorado, where upslope flow helped deep snows accumulate as the storm system moved across New Mexico.
Upslope flow is simply wind blowing from lower ground to higher ground.
Here, the northeast winds in eastern Colorado rose across the Great Plains into the high country, rich moisture condensed into clouds, which dumped the moisture on the ground as snow. Moist upslope flow is the most efficient precipitation machine known, and has caused most of the heaviest snow falls around the world. Numerous geologic features show up well in the snow fields.