Memorable Snowfall Hits Deep South, Skirts Big Cities
A quick-moving snowstorm zipped from northeast Texas to southern Virginia in little more than 24 hours, leaving some parts of the Deep South with more snow than they’ve seen in decades. Rather than carving a deep trough in the eastern U.S., the upper-level energy that generated the snow tracked along the base of a broad pre-existing trough. This channeling of energy helped lead to a storm that had a vast extent from southwest to northeast but a narrow north-south gradient from substantial snow to little or no accumulation. The transition zone happened to fall across or near some of the largest cities of the South, which led to tough forecast challenges, just as we saw in the nor’easter last month that left New York City on its west edge.
Here are some of the broad variations in snowfall reported in and near metro areas across the South from the Wednesday/Thursday storm.
Little Rock, AR: 0 - 2”
Memphis, TN: 0 - 2”
Birmingham, AL: 0.5 - 4.0”
Atlanta, GA: 0 - 1”, with several inches across far northern suburbs
Charlotte, NC: 1 - 3”
Raleigh-Durham, NC: 3 - 5”
Norfolk, VA: 3 - 8”
Numerous cancellations and closures occurred across the Atlanta area on Wednesday night into Thursday, yet the storm produced less than an inch across the city, with larger amounts limited to the far north end of the metro area. When you zoom out and look at the big picture for northern Georgia (see Figure 1), the storm was very well forecast--but variations on the order of 15 miles, which are well within the error of current modeling systems, can make or break the outcome when they happen to fall across a city as populous as Atlanta. According to the University of Georgia’s Marshall Shepherd, this was a “great forecast, given where our capability currently lies . . . but if you expected something and didn’t get it, you may be upset.” Shepherd recently covered the ins and outs of snow prediction in the South in his Weather Underground blog.
Figure 1. A comparison of snow amounts predicted by the NWS/Atlanta office on Wednesday morning, Feb. 25 (left) and preliminary amounts as of Thursday morning (right). Although the forecast as a whole was quite accurate, the south edge of the heavier snow ended up just north of Atlanta instead of on top of the city. Image credit: NWS/Peachtree City, GA, courtesy Marshall Shepherd, University of Georgia.
Figure 2 (right). A youngster in Oxford, MS, savors a rare snowfall of significance. Image credit: wunderphotographer OxfordWeatherGeek.
The most impressive amounts for location and time of year occurred across central and northern Alabama and Mississippi. Tupelo, MS, saw 7.3”, its second-largest one-day snowfall on record (topped only by 8.0” on January 24, 1940). Huntsville, AL, also saw its second-snowiest day on record, with 8.1”; on Dec. 31, 1963, the city reported 15.7”. The region between Birmingham and Huntsville saw amounts exceeding 10” in spots, the heaviest observed there since the Superstorm of March 12-14, 1993. Weather Underground historian Christopher Burt discussed the greatest snows in the history of the South in this 2011 blog post.
A February to remember (or forget!)
Next week we’ll take a close look at national and regional statistics for February as a whole, which are bound to be impressive. In the meantime, here are a couple of samplers from the temperature realm:
--Syracuse, NY, is wrapping up its first month in 103 years of recordkeeping without a single measurement above freezing. The city touched 32°F only on February 4, with the next-warmest reading to date a mere 28°F. To make matters worse, Syracuse has dipped below 0°F a total of 21 days this winter, beating the record of 19 days set in 1947–48.
--Boston, MA, averaged 18.8°F for the period Feb. 1 - 25. That’s considerably lower than the February average so far in Aspen, CO (31.0°F), Anchorage, AK (24.9°F), and Moscow, Russia (26.1°F). All three of those cities are running well above their normal February temperatures, whereas Boston is usually about 10°F warmer than those three cities in February.
--In Salt Lake City, UT, the average daily high for Feb. 1 - 25 was 55.2°F. That’s the city’s long-term average high on the spring solstice in late March.
This week’s WunderPoster: Snow rollers
This week’s entry in our WunderPoster series (Figure 3, right) features snow rollers, one of the quirkiest phenomena observed in snow-prone regions. Sometimes up to two feet in diameter, these features are formed when a thin layer of wet snow atop ice or powdery snow gets disrupted by a windblown chunk of snow that pulls up some of the underlying snow in a cinnamon-roll-on-its-side fashion. All WunderPosters can be downloaded in formats suitable for posters or postcards.
Figure 4. This fleet of snow rollers was captured on January 27, 2014, at Green Camp, Ohio. Image credit: wunderphotographer Gordanian.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
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