Archive for southern snow

Major Winter Storm for the Deep South 1/9-1/11/11

Posted in Extreme Weather Video, Severe weather, Winter weather with tags , , , , , , , , , , , , , on January 9, 2011 by stormstream

Winter storm warnings and ice storm warnings are up for much Dixie as a major winter storm develops and rolls across the region. Some locations will see more snow than they have seen in decades, while others get more ice than they have witnessed since the big hair days of the 1980s.

I will concentrate mainly on Alabama, Georgia and South Carolina in this blog posting, since this is the region I live in and forecast for.

Basically, we can use I-20/I-85 as the boundary between significant snow and ice, with the I-20 corridor receiving a nasty mixture of both types of deadly winter precipitation. It appears from the latest runs of the HRRR (Rapid Refresh) short-range model and NAM, the heavies snow band with this system is going to streak out across central and northeast Mississippi and into northwest and northern Alabama and into southern middle Tennessee, southeast Tennessee, southwest North Carolina and the upstate of South Carolina. The deformation band where the longest duration of heavy snow will establish itself looks to be across parts of northeast Mississippi and northwest and north-central Alabama into extreme southern middle Tennessee and southeast Tennessee. This region would be one of the jackpot snow regions with more than 10 inches of snow possible. Yet another “jackpot” snow area aided by elevation would be the northeast & north-central Alabama/extreme southern middle Tennessee area, centered on the Lookout mountain area where more that a foot of snow could accumulate on the crest of the ridge. Obviously, a third so-called jackpot snow accumulation region would be the elevation-aided region of the southern Appalachian mountains from extreme north and northeast Georgia northward into southeast Tennessee and southwest North Carolina. This region, especially the TN and NC portion of that region could see over a foot of snow, with some of that accumulation coming on Tuesday and Wednesday with the passage of a clipper and the enhancement from a moist northwest flow in the wake of that system. The remainder of the Alabama, Georgia and South Carolina region to the north of I-20 & 85 will see generally 3 to 8 inches of snow, with the lesser amounts along I-20 and the accumulated snow depth increasing as you head north from I-20 with generally an inch added for every 20 miles north. Hopefully that makes sense. lol Here are some forecast totals for the airports in the region: ATL 4″. BHM: 2″. MCN: 1/2″. HSV: 12″. CHA: 11″. GSP: 8″

Now to probably the most life and property-threatening aspect of this major winter storm, the ice. Areas south of I-20 in Alabama and Georgia will start out as snow, but transition to sleet and then to light, but very steady and long-duration freezing rain and drizzle. This type of light, but steady long-duration freezing rain and drizzle is the very worst type of freezing rain as everything that falls will freeze on exposed objects and not run off. Widespread accumulations of 1/4 of glaze on exposed objects will be common south of I-20 in AL and GA to within 75 miles of the Gulf coast. 1/4 inch of glaze is the threshold for damaging freezing rain, especially softwood trees such as pines. So, widespread pine tree branches will come down onto power lines, and that will induce power outages. Of more concern is the potential for fairly large areas of .50 inch glaze ice accumulations on exposed objects within that wide .25 inch zone. These areas will see severe ice storm damage with hardwood trees such as oak, hickory and walnuts not only losing large branches, but actually splitting and falling onto home. Many pines will lose branches and bend all the way to the ground. It will be an absolute disaster for the trees of the region, and of course since we love our trees in the South we surround our homes and businesses with them. This means widespread structural damage as well as power outages from fallen branches and trees on utility lines. Here are some forecasts for glaze ice accumulations on exposed objects for the same airports I gave snowfall projections for: ATL: .10 BHM: .20 MCN: .40 (severe ice storm) HSV: .00
CHA: .00 GSP: .05

Folks, this is a system that is going to continue and evolve and change through the day on Sunday, so the forecasts I provided above, while being my best estimate based on current data, could very well change for the better or for the worse as the day goes on. The key is to not concentrate on the minor changes in terms of snowfall and ice accumulation forecasts, but just to understand and take serious the severity of this winter storm. Be weather-aware and take preparations and precautions to protect you and those you know, as well as your property. Be ready and prepared to lose power, especially in the ice storm region, and be prepared for the worst-case-scenario of not having power for several days to even as long as a week or two in very rural areas as utility companies will be stretched thin.

I plan to cover this winter storm in the Atlanta and north and central Georgia region starting this evening and continuing through the day on Monday. I will be broadcasting LIVE at http://stormscapelive.com and also at http://www.chasertv.com. Live streaming should start around 8pm on Sunday, January 9 and continue through the night and into the day on Monday, January 10. However, if conditions on the roads become to severe to safely cover this winter storm I will return home, but continue to stream from my neighborhood. Another great location to view live streams of this winter storm is at the Bama Camera Net on the Alabama Storm Trackers web page. The address is http://alabamastormtrackers.com/alcamnet/.

Good luck and stay safe!