Astronomy Picture of the Day

Explanation: What are those strange clouds stretching out from these lakes? The clouds are caused by cold air moving over a warm water and result in bands of lake-effect snow. The rising bands of moistened, warmed air that drop lake-effect snow alternate with clear bands of falling cold air. During a winter, such bands can create hundreds of centimetres of snow more than upwind areas only a hundred kilometres away. During this lake-effect snowfall of 2000 December 5, practically all of the state of Michigan, USA got covered. A cold northwesterly wind over Great Lakes Superior and Michigan created the unusual clouds. The above image was taken with NASA's SeaWiFS satellite.