Why the Deep South is seeing surprise snow
Between 1 to 5 inches of snow have been forecast across Alabama, Tennessee and North Georgia, according to the NWS.
Mon, Nov 28, 2011 at 04:32 PM
'ISLAND' OF WINTER: The National Weather Service's map for Nov. 28. An area of area of low pressure in the atmosphere has formed a 'cold bubble' that has created the wintry weather. (Image: NOAA/NWS)
In a weird weather reversal, cities in the Deep South are under winter weather advisories while northern cities, more accustomed to snow this time of year, are flirting with record high temperatures.
From Memphis, Tenn., to Atlanta, a rare Southern snow may coat cities tonight (Nov. 28) as the temperatures and precipitation continue to fall. The southern slide into winter is due to a "cold bubble" that has formed over the South, said forecaster Brian Carcione of the National Weather Service (NWS) in Huntsville, Ala., where an inch of snow is expected.
Between 1 to 5 inches (2.5 to 13 centimeters) of snow have been forecast across Alabama, Tennessee and North Georgia, according to the NWS. Much of the snow should quickly melt, with little accumulation on roads, but the wild plunge into winter is a jarring halt to the warm Thanksgiving week in the South. Temperatures there were well above 70 degrees Fahrenheit (21 degrees Celsius) yesterday.
That warm air has pushed to the Northeast, whereNew York City set a record high temperature for today at 70 F, breaking a record set in 1896 and tied in 1990. Newark, N.J., hit 72 F (22 C), one degree shy of a record high. Yesterday, Dulles International Airport in Washington, D.C., set a record high for the day at 70 F. [The World's Weirdest Weather]
Those balmy days are long forgotten for the South, where news stations have gone to wall-to-wall coverage of the snow. While not severe, the early snow is a weather oddity for cities such as Atlanta. The average date for the earliest measurable snow here is Jan. 21, according to the Weather Channel.
The icy weather is due to a large area of low pressure in the atmosphere that has settled over the middle of the country. The bottom of that dip, or trough, has closed off into a large upper atmosphere low-pressure system — the cold bubble — centered over Mississippi, Carcione said.
"It's a cold system. It's a dynamic system," Carcione said. "Sort of like an island unto itself."
This energetic system has a lot of cold air as a part of it, and it's able to create precipitation bands that are heavy enough to bring some of that cold air to the ground. Snow is already being reported from Muscle Shoals, Ala., to Columbus, Miss., Carcione said.
The cold bubble is on the move — slowly — toward Northeastern cities, where it should lose some energy, but could still bring wintery weather with it, but with less fanfare.
"In late November, they're a little more used to this kind of weather," Carcione said.
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