The Atlanta Journal-Constitution
THIS WINTER WON’T LET GO
Snow or no snow? Lack of certainty frustrates residents and officials.
Shortly after 2 p.m. Wednesday, puffy white flakes of much-anticipated snow finally began hitting the pavement of the northern Perimeter.
The forecast for that moment displayed on Weather.com: 100 percent chance of light rain.
In the days ahead of the storm, and even as it occurred, weather forecasters in metro Atlanta sought to draw certainty from wildly uncertain computer models. Entire school systems shut down in areas where no snow or ice stuck to the asphalt from morning to the afternoon closing bell.
At mid-afternoon, some commuters in Gwinnett county drove through dry patches followed by patches of icy sleet. Others Cherokee, Cobb, Forsyth and Paulding counties encountered thick snow and even roads that were impassable, especially as evening advanced.
Thursday’s morning commute held the potential for icy overpasses in the metro area, but at 8 p.m. Channel 2 Action News meteorologist Brad Nitz said it looked like new snow would be largely confined to the more mountainous areas.
“We see it frequently that the dividing line between liquid and frozen precipitation is somewhere across our area,” said Nitz, adding that that can mean “snow versus no snow for millions of people.”
At 7 p.m. Wednesday, Georgia Department of Transportation road sensors were showing pavement temperatures in the 34 to 37-degree range south of I-20; and in the 32 to 34 degree range north of I-20 in metro Atlanta and the immediate northern suburbs. GDOT said that, with freezing temperatures anticipated overnight, some road icing was likely.
The lack of certainty may frustrate residents and officials, but meteorologists understand it as a fact of the city’s geography and topography.
“Atlanta weather doesn’t surprise me anymore,” said Will Lanxton, the state meteorologist for the Georgia Emergency Management Agency. “If you expect it to be crazy, it will never surprise you.”
The region gets dissed for not knowing how to deal with snow, but a bigger problem may be that Atlanta is rarely sure just when it will get snow. Just as some cities are situated in zones for tornadoes, floods, or blizzards, Atlanta, caught between weather borders, is situated in a zone of uncertainty.
Meteorologists can tell when a storm system is coming our way. But a storm that would clearly mean snow in more northerly climes is much harder to read in metro Atlanta, where temperatures often hover just at freezing. Two or three degrees’ one way or the other can make all the difference in the actual impact.
A couple of factors place Atlanta at the fluctuating edge of freeze and thaw. First, how far south it is. Second, its position in the Appalachian foothills.
Often, cold dry air traveling down the eastern side of Polly Hines offers her dog Baxter a snowball Wednesday as heavy snow fell in the area. “I’m a retired school teacher and I still get excited about snow days” said Hines. the mountains gets stuck, or “dammed,” against them Nitz said. When warmer, wetter air from the Atlantic or Gulf of Mexico rides up over that cold air mass, the interplay between them causes temperatures to fluctuate throughout the vertical column of air. As moisture condenses and falls through that column, it can produce snow, sleet or rain — either in turn or in combination.
Then, too, Atlanta’s footprint is so large, the impact is often radically different in different parts of the metro area.
“The impacts here are a whole ‘nother animal in a way that they really aren’t up north,” said Nick Wiltgen, senior digital meteorologist at The Weather Channel. He has lived and worked in cities from Chicago to Huntsville, Ala., to Philadelphia.
From his office in Cobb County Wednesday he watched snow change to rain and back again. The temperatures were so close to freezing that sometimes whether it fell as snow or rain depended on whether the snow itself was heavy enough to cool the air as it fell, he said: “We’re that close to the fence.”
Lanxton said his models have been pretty definite for several days that “something” would happen. But the exact nature of that something was elusive.
“We saw last week, even the ‘nowcasting’ — not even forecasting what is about to happen but what is happening right now — was troublesome, because there are so many variables at play,” Lanxton said.
In any case, local and state officials were taking no chances, not after last January’s debacle. Computer models did a good job of showing where that winter storm would land, but they didn’t predict the amount of snow the metro area would get until the early morning hours of the same day it hit. Government officials didn’t react in time, and the massive traffic catastrophe resulted.
This time, state offices spent the week preparing. At a Wednesday news conference Gov. Nathan Deal said he did not expect to close off the roads to truckers, but he delayed the opening of state offices Thurs- day to 10 a.m.
Deal thanked residents who stayed home Wednesday, noting lighter-than-usual morning traffic. Atlanta Mayor Kasim Reed implored those who had gone to work to leave at staggered times.
Whether in response to such pleas or on their own, many workers did head home early. The most heavily traveled highways slowed to a crawl between 2 and 3 p.m., then flowed freely during the normal rush hour.
About 500 state transportation workers pre-treated highways across the northern third of the state, and more crews were set to dump salt and gravel on the roads as the snow and freezing rain began to fall. Another 174 state troopers were assigned to help sort out traffic and remove debris.
And even though things went smoothly Wednesday, “we don’t want people lulled into the sense that roads are OK,” said state Transportation Commissioner Russell McMurry. “We don’t want a false sense of security to set in.”
MARTA announced that it would shift buses to a Saturday schedule with less frequent service Wednesday evening, with many buses terminating at 11 p.m., and train service ceasing after 1 a.m. Thursday. There was no word on when it would resume Thursday or on what schedule.
Atlanta deployed eight brine spreaders and 75 other pieces of equipment to deal with the weather. The city also opened warming shelters.
Binnie Case of Flower Branch was prepared with gas and groceries, after being trapped at home for seven days last year.
But looking at the flakes coming down hard late Wednesday afternoon, she christened the blizzard of Feb . 25, 2015 a minor inconvenience.
“It won’t even stick,” she told The Atlanta Journal-Constitution while filling her Honda at a Shell station.
She was right about the snow — at least as far as Wednesday evening went. By 4:30 the snowfall had turned to sleet and rain. We’ll have safety advice and the latest news on any closings or dangerous road conditions at myAJC.com. Severe Weather Team 2 will be updating the forecast during the day at Channel 2 Action News and at wsbtv.com.