Change is constant, especially in spring. April snow happens in Chicago. Midway through this week one day produced 5.5 inches of rain and yesterday began with snow covered lawns, shrubs and not so tendar spring blooms. As quickly as the snow acumulated the morning sun by 9:30 melted away evidence of its appearance. Today air is still a chilly 40 degrees, but the sun is shining and the blooms are once again upright and vibrant.