File:Lake Erie, Lake Ontario, and the Finger Lakes (MODIS 2017-01-13).jpg

English: Snow fell across the northern United States in late December 2016, leaving a blanket of white for the down of a new year. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured a true-color image of snow across Lake Erie, Lake Ontario, and the Finger Lakes.

Lake Ontario sits in the north with Lake Erie to the southwest. The waters of Lake Ontario appear dark blue, while Lake Erie’s water is colored with sediment and, most likely, an algae bloom. The Finger Lakes, located in New York state, stretch southward roughly perpendicular to Lake Ontario. The small, roughly round lake in the north is Lake Simcoe. A heavy blanket of white snow spreads over the ground in Canada (north), while south of Lakes Erie and Ontario a lighter wash of snow lies over Pennsylvania and New York.

The snow to the south and east of the two Great Lakes is an example of lake-effect snow. Snow falls in these regions when cold air passes over the lakes and picks up moisture. The moisture freezes into snow, and when the snow-filled air moves over the roughened topography of the land, snow falls. This can happen very quickly and often falls in bands to the south and east of the Great Lakes.