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Column: Why is Georgia weather all over the place?
Rudi Kiefer

Cold weather doesn’t originate in Georgia.  It comes from the northwestern portion of the continent. Its imported status explains why our weather is so changeable. 

But “The Northwest” isn’t one uniform area. While writing this, I was checking some temperatures.  Seattle, Washington: 58 degrees. Juneau, Alaska: 31 degrees. Away from the coast, east of the Pacific mountain ranges, things get more serious. Edmonton, Alberta: 32 degrees. Yellowknife, Northwest Territories: 14 degrees. Circle Hot Springs (a station east of Fairbanks, Alaska): minus 31 degrees. For comparison: The Russian town of Norilsk, Siberia is 300 miles closer to the North Pole than Fairbanks. Norilsk isn’t known for balmy December weather or abundant sunlight. But its 9 degrees below zero sound better than the minus-thirties of interior Alaska. Clearly, Alaska and the interior plains of Canada are the home of cold weather right now. 

Unfortunately for the sun-drenched U.S. South, places don’t just “get cold” and stay that way. Cold weather is caused by the inability of the earth’s surface to retain heat. The ground in, say, Sleetmute, Alaska, loses its heat content into space rapidly at night. There isn’t much moisture in the atmosphere to slow this process. Air in contact with the cooling ground gets heavy and settles downward. There’s only limited space for that big amount of air sinking down, so it has to spread out. That’s why after a few days, even the Southern States get wrapped in that cold, dry air from far-away Alaska. 

The colder Alaska gets, the faster its air mass can spread and invade the central, southern, and southeastern regions of North America. The weekend of January 29-31, 2010, was an example. A fast-moving winter storm dumped heavy snow on western North Carolina and northeastern Georgia. Mills River, near Asheville, reported 14 inches of snow. Hall County and surroundings had freezing rain and only light snowfall. But once the imported northwestern air had established cold, dry conditions here, the door was open to something bigger. On February 12 of that year, a traveling storm in the Gulf supplied the moisture that was missing from the northwestern air sitting here.  Heavy snow fell in Northeast Georgia, extending all the way into Florida. It was the typical but rare scenario for our area: Cold, dry air from the Northwest teams up with moisture from the Gulf Coast, and snow comes to Hall, White, Habersham and Banks County.

Rudi Kiefer, Ph.D., is a professor emeritus of physical science at Brenau University. His column appears Sundays and at