Where are the Clouds? The Snow?

Where are the Clouds? The Snow?. . , Summer sailors know that high clouds float over land. Lakeshore residents know that winter winds bring lake-effect snow. , June , In spring and summer, the air over the land is warmer than the water in the lakes. Warm damp air rises from the land and forms clouds over the land. The sky above the lakes remains clear. , December , The lakes retain much of their fall warmth and so remain ice free. , When very cold, dry air blows east or south across the lakes, “cloud streets” are formed as evaporation sucks moisture and heat from the lakes. This satellite image shows the streets as stripes of clouds which are perpendicular to the winds from the west. , When these clouds hit land they drop their moisture as “lake-effect snow.” , This phenomenon sucks massive amounts of heat and moisture from the lakes and by January, the lakes start to freeze over. Once frozen, lake-effect snow no longer occurs. , Roughly half of our snow comes from the west across Lake Michigan as lake-effect snow, the other half comes from the south. , Snow belt. Lake-effect snow is most abundant when the temperature difference between the cold air and warm water is greatest, usually in November. This November temperature differential causes high winds, often blizzards, and historically famous shipwrecks. , The Good News. The snow belt moderates temperatures allowing for the fruit belt. These pink snow-belt areas feature cherry trees and vineyards as well as heavy snow. , Information compliments of Dr. Peter D. Blanken, Professor, Department of Geography University of Colorado at Boulder