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.