It wasn’t the typical kind of Alabama snow day. Not by a long shot.
What many expected to be a minor winter weather event with a dusting of snow suddenly turned chaotic on Jan. 28, 2014, as snow fell, melted on roads and then refroze, paralyzing most major thoroughfares and stranding thousands in central Alabama.
“It’s pretty rare,” said Jim Stefkovich, the meteorologist in charge at the National Weather Service office in Birmingham. “You can get freezing rain events here, but it’s pretty rare to have a snow event where it was in the upper teens here in Alabama. That just doesn’t happen very often.”
The trouble began on a Tuesday, but just two days earlier it was near 60 degrees across a lot of central Alabama.
The ground was warm — and the roads were warm. Hardly the precursor to a winter storm.
Then an arctic front moved across the state. And that front brought with it very cold and very dry air, Stefkovich said. It was so dry that, according to the National Weather Service, a few locations in central Alabama had dew points below zero.
Next, an upper-level disturbance moved into the area and the headaches began.
The air in place over Alabama was so dry by that point that it was difficult for forecasters to determine how long it would take the approaching disturbance to moisten the atmosphere enough to produce precipitation. And it happened faster than anyone was expecting.
“A lot of times when precipitation falls from very high in the atmosphere, it melts. In other words, you have to saturate the atmosphere before it reaches the ground,” Stefkovich said. “And what happened was the precip obviously saturated the atmosphere much more quickly than we anticipated. And it started falling to the ground probably 2-4 hours prior to when we thought it would start.”
In typical Alabama snow events, it’s very close to freezing when precipitation falls. But then temperatures rise fairly quickly, and what’s on the ground fast becomes a memory.
Not so this time.
“(Temperatures) never really got out of the high teens or maybe around 20 degrees,” Stefkovich said. “And of course that’s what caused all the icing problems on the roadways.”
Snowfall amounts in central Alabama on Jan. 28, 2014. Most of Jefferson and Shelby counties and surrounding areas received “advisory amounts” of snow, said Jim Stefkovich, the meteorologist in charge at the National Weather Service in Birmingham. “But the impacts were tremendous.” He said a key point for those living in Alabama to remember is: “Regardless if it is a winter weather advisory or warning, dangerous conditions may exist for both, especially while driving.” (National Weather Service)
The ground was relatively warm when the snow began falling, but then the temperature plummeted and that melting snow quickly became a sheet of ice on roadways. And it stayed put for a while in the sub-freezing temperatures, paralyzing travel for days.
Also out of the norm were 20:1 snowfall ratios — which were “almost unheard of” in Alabama with this event, according to the weather service (10:1 is more typical).
“The colder and drier the atmosphere is — especially near the ground — (it means) it would take 20 inches of snow to make 1 inch of rainfall,” Stefkovich said. “In summertime thunderstorms you can get one inch of rainfall. This is the thing that’s amazing. If you melted the snow that occurred — that 1 and a half to 2 inches — that basically came out to 0.08 inch of rainfall. That’s a light shower during the summertime over your house.”
According to the weather service, snow totals in ranged from nothing in the northwest part of central Alabama to up to 3 inches in an area from Chilton to Randolph counties. Some other areas in the southeast part of central Alabama also got up to a quarter-inch of ice.
“We really had the freezing rain/snow/sleet line pretty well figured out. We were off by about 40 or 50 miles as far as believing where any accumulation would occur,” Stefkovich said. “We had it just south of Shelby County and it went all the way up into Jefferson and St. Clair counties.”
But winter weather in Alabama hardly ever follows the script.
“First of all, nobody can beat us up any more than we beat ourselves up as forecasters. Because we want to be perfect,” Stefkovich said. “Our families live in Alabama too. And the bottom line is we know that there are millions of dollars at play here whether it’s the loss of business time or people getting stuck on the roads or school closings. We’re really trying our hardest to be as exact as possible.
“The easiest thing in the world we could do would be to just say 1-3 inches everywhere and be done with it, but that doesn’t serve a purpose either because that’s crying wolf and you have businesses closing that don’t need to. … It’s just a daunting task.”
By Leigh Morgan on www.al.com