© NASA Goddard MODIS Rapid Response TeamThe MODIS instrument on NASA's Terra satellite captured this image of snow on December 7, 2010 at 17:05 UTC (12:05 EST). Snow appears on the ground in eastern Minnesota and Iowa, southwestern Wisconsin, northern Illinois, much of Indiana, northern Kentucky and western Ohio. The white area over Lake Michigan and southeast into northern Indiana and Ohio are clouds.
NASA's Terra satellite captures daily visible and infrared images around the Earth and took a daytime image of a blanket of snow in the Upper Midwest this week. Even though astronomical winter is less than two weeks away, the central and eastern U.S. are already experiencing meteorological winter.
Meteorological winter is basically an identification of the winter season based on "sensible weather patterns" for record keeping purposes. That means "meteorological winter" happens whenever snow and ice occur, even before astronomical winter arrives on December 21, 2010. Astronomical winter is based on the position of the Earth in its orbit around the sun.
The residents of the upper Midwest are already feeling the effects of winter this week, with high temperatures in the 20s and 30s, and wind chills in the single numbers (Fahrenheit) or colder. The satellite image of snow on the ground in the upper Midwest is proof of an early meteorological winter.
It was captured by the Moderate Resolution Imaging Spectroradiometer or MODIS instrument on December 7, 2010 at 17:05 UTC (12:05 EST). MODIS is an instrument that flies aboard NASA's Aqua and Terra satellites.