Those who have never spent much time along the Colorado Front Range often imagine that the region is snowbound for at least six months of the year. But, while it may snow in Metro Denver during ten months of the year (July and August are generally the exceptions), the city enjoys mild, sunny weather most of the time, even during the winter season.
In fact, most of the snow along the Front Range urban corridor falls in March, April and November (in that order). Since the Continental Divide "wrings out" moisture arriving from the Pacific Ocean, snowfall east of the mountains is primarily the product of Gulf of Mexico moisture, pulled northward and westward across the Great Plains. As storm systems move eastward, counterclockwise winds around the central zone of low pressure sweep the moisture-laden air toward the Front Range, causing it to rise and cool; depending on the regional air temperature, the "upslope precipitation" falls as rain or snow. Denver generally gets its heaviest upslope snowstorms when the surface low moves eastward along the Colorado-New Mexico line.
The upslope snowstorms of March, April and, yes, early May bring most of the annual snowfall (which averages 55 inches) to Metro Denver. Fortunately, the intense spring sun usually melts the snow within a day or two and provides warm interludes between the storms. After a mild, dry winter, many of us who live along the Front Range hope that spring storms bring plenty of moisture this year (even if the heavy, wet snow flattens the tulips).