Snow on Colorado rocks (USA)

View of snow lying among the rocks of Arizona, which are usually burnt by sun, is not the most frequent one. Arizona is located in the zone of tropic and subtropic climate, which means that the average temperature of the coldest month in this state equals +10 Celsius degrees. However, weather anomalies have occurred always and everywhere. Weather anomalies are most interesting mostly due to the fact that they undermine some stiff notions about the climate in various parts of the world. Have you heard of snow on the Sahara?