During the late fall and early spring months, the color of the ground is typically responsible for determining how warm or how cold our temperatures will be on a given day. The phenomenon behind this is known as, Albedo. It's a unitless measurement of how effective a certain surface is at reflecting incoming solar radiation on a scale from 0, known as a block body, to 1.
As the angle of the sun continues to decrease heading towards the winter solstice, we receive less in the way of incoming solar radiation compared to our warm, summer months when the amount of solar radiation is maximized. Because of this, we typically rely on ground conditions to drive a warmer temperature pattern in addition to a strong southerly flow.
If the ground remains snow-free during the winter, more incoming solar radiation is absorbed because that bare ground has a low albedo. Very little is reflected back into the atmosphere. This maximizes the suns energy and helps keep our temperatures on the mild side. This theory also holds true when you go car shopping. During the summer months, a black or dark-colored vehicle may not seem very attractive because they are seen as heat magnets. They absorb a good chunk of the incoming solar radiation, effectively making them hotter. A 2011 study by Berkeley Lab Environmental Energy Technologies Division found that light colored cars, such as white and silver, reflect up to 60 percent of sunlight compared to dark colored cars.
Like a bright colored car, when snow is located on the ground it is extremely efficient at reflecting nearly all of the suns energy back into the atmosphere. This keeps temperatures cooler because none of that incoming solar radiation can be absorbed and used for heating.
Until we get another substantial snowpack on the ground either here or somewhere nearby, don't expect any major artic outbreaks anytime soon.
Meteorologist Andrew Stutzke
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