John Wheeler, WDAY, Published February 27 2014
Weather Talk: Old snowpack has kept it from being even colderOur weather has been bitterly cold lately, but it would have been even colder had our snowpack been in better shape. Snow covering the ground makes the air near the ground colder by insulating against heat within the ground, by reflecting sunlight back into space, and by increasing terrestrial radiation output at night.
The quality of the snow pack matters in each one of these effects. Old, granular snow is a poor insulator compared to new, fluffy snow. Likewise, old, dirty snow is a poor reflector and radiator compared to fresh, white snow. Also, old snow invariably leaves patches of ground open to the air. Had our ground been covered with a deep white layer of freshly fallen, fluffy snow, temperatures the past few days would have likely been
5-10 degrees colder.
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