Archive for the Winter weather Category

A little rain and snow overnight, with a bigger winter storm possible early next week

Posted in Winter weather with tags , , , , , , , on January 20, 2011 by stormstream

The Atlanta metro area will see some rain and wet snowflakes during the early morning hours of Friday, January 21, 2011. There may be a dusting of snow in some areas by sunrise – a rather rude reminder for the folks of Atlanta that winter is far from over. Be careful as you drive to work or school Friday morning as there could be a few icy areas, especially on bridges and overpasses.

A more significant winter storm has its sights set on the Southeast region, including Atlanta for next Monday, January 24 and Tuesday, January 25, 2011. It is still way to early to talk specifics or even show any serious confidence that this storm will happen, but it is definitely on the forecast models in varying degrees of severity, so it needs to be mentioned. As it stands right now for Atlanta, it looks like precipitation could start as snow, then transition quickly to freezing rain, and then possibly to rain as the system moves out. Precipitation totals look to fall within the light to moderate range, but when dealing with freezing rain even light amounts can cause serious travel issues. So, just a heads-up at this point to watch the weather forecast closely for next Monday and Tuesday. I should have a much better handle on the specifics of this system by the weekend, and I will post further thoughts then.

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!

Late Season Winter Storm for Dixie

Posted in Winter weather with tags , , , , , , , , , , , , , on February 28, 2010 by stormstream

A late season winter storm is taking aim on parts of the Deep South.

Low pressure will roll eastward out of New Mexico & Texas on Monday tracking across the northern Gulf of Mexico, or just inland along the Gulf Coast states on Monday night and Tuesday. Meanwhile, some upper level energy from the northern branch of the jet stream will phase with this system, and give it a shot in the arm as it impacts areas from Alabama to Georgia and into South and North Carolina.

Temperatures are only going to be marginally supportive of snow, and really this could go either way fro areas of Alabama and Georgia. It’s either going to mostly all rain with maybe a brief changeover to snow for a few hours at the end of the event. Or, it’s going to be rain changing to a wet, heavy snow with large snowflakes falling steadily for at least 6 hours and accumulating to several inches. Unfortunately, we probably won’t know exactly how this is going to hash out until the actual event is unfolding on Monday night and Tuesday.

So, as of this time on the Sunday morning prior to the event I am not willing to put out an official forecast, so here is my unofficial thinking: 2 inches for Atlanta, GA, and 1 inch for Birmingham, AL. Mt. Cheaha, the highest elevation in Alabama could pick up 3 inches, and the east and northeast metro of Atlanta could see 3 inches, with maybe some isolated 4 inch amounts.

I’ll give my official thoughts on this system by 11pm EST on Sunday.

Finally! El Nino is Bringing Extreme Weather to the U.S.

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , on January 24, 2010 by stormstream

It’s taken half the winter to get here, but finally the low end strong El Nino weather pattern is bearing some major fruit in the U.S. in the form of extreme weather, and this active pattern looks to continue at least through the month of February, and very likely into the spring as well. Get ready for a continued wild ride on the Extreme Weather Express!

The jet stream is powerful and infused with moisture. This has led to many feet of snow across the mountains of California and the Southwest, and severe thunderstorms and tornadoes across the South. Now, we are once again heading into a period where the AO is severely negative, the NAO is negative and PNA is positive. This all equals major DOO DOO for much of the U.S. as we head into late January and through the month of February, but the most extreme weather will likely shift from the western U.S. into the central and eastern U.S. More severe thunderstorms and tornadoes will be possible in the Deep South, with major snow storms north of the heavy rain and severe storms. Also, serious intrusions of bitterly cold arctic air will be dropping into the lower 48 on a regular basis.

Anyone hoping for an early spring with an extended period of sunshine and mild to warm temperatures can kiss those hopes goodbye through at least mid-March, and I don’t care what that glorified rodent The Groundhog says in early February.

Southeast Winter Storm and Cold Wave

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , on January 3, 2010 by stormstream

It’s not often that we are 4 days away from a winter event in the Southeast, and most of us in the know are feeling reasonably confident about the forecast. Now that this pattern evolution that has been ongoing for more than a month has finally reached its concluding stages, the medium range models are going to handle the pattern reasonably well for the next few weeks. So, not only is this event going to be handled well, the upcoming winter events (one or two could be significant for the Southeast) over the next two weeks will also be handled better than they would have a few weeks ago. This is good news for those of you who make a living forecasting this stuff. I think it is pretty clear that the Thursday/Friday system is going to be a light to moderate snow producer for areas along and north of I-20/I-85. I agree with the general consensus of this being a widespread 1-3 inch snow, with a few jackpot amounts in the 4 to 6 inch range. Here is what we need to focus in on regarding this event: It may not be a big snow storm, but it will be a high-impact winter storm. The cold ground will insure that snow that falls will immediately stick to all road surfaces and create immediate travel problems. For areas where the snow moves in during the day on Thursday this will create a situation where schools and businesses will need to anticipate this and close early to avoid a life-threatening afternoon rush (shades of “Snow Jam ’82”). Then, there is the aspect of out-of-the-ordinary cold. The cold will not be record setting in terms of temperatures, but could approach record levels in terms of its longevity. With such long-lasting cold this will pose a serious threat to folks who do not have adequate heating for their homes, and also for pets outside. Please be sure to take the necessary measures to protect those two groups. Also, make sure to insulate any pipes on exposed outer walls and leave your faucets dripping. Anyone who has ever dealt with busted pipes knows this is an incredible inconvenience as well as being very expensive. Please DO NOT use a torch to thaw out your pipes or you will torch your house. Finally, the snow that falls will not melt off the next day as is the case with most Southern snows. This snow will be on the ground and on roads and parking lots for days. It will get packed down and create very icy and dangerous areas. So, while not a big snow storm, this one will certainly be a dangerous and problem-causing situation during the snow fall and several days afterward. Finally, I want to address the chance for a swath of significant freezing rain to the immediate south of the snow. The fact that this will be a fast moving system should limit freezing rain amounts, but it will still be enough to create glazing and cause problems.

Active Pattern to Continue into the New Year!

Posted in Severe weather, Winter weather with tags , , , , , , , , , on December 12, 2009 by stormstream

We are locked into an active weather pattern across much of the country that should last into the New Year. Many significant storm opportunities and blasts of arctic air can be expected. Looking into my long range forecasting crystal ball I see the next big-ticket storm system affecting parts of the country with heavy snow and rain a few days either side of Christmas. Right now I’d say the most likely regions impacted would be from the Plains to the Southeast, Mid-Atlantic and Northeast. Maybe a white Christmas for many? I hope so!

Severe Weather across the Tennessee Valley and Southeast on Sunday, with Significant Snow across the Southern Appalachian Mountains from Midday Monday through Late Tuesday Night

Posted in Severe weather, Winter weather with tags , , , , , , , , , , on April 5, 2009 by stormstream

Severe weather will be possible on Sunday across parts of KY, TN, AL, GA, SC and NC.  I will concentrate only on the severe weather prospects across south and central GA and north FL, as that will be the area I will target to storm chase if I should decide to head out.

A cluster of elevated thunderstorms is rolling eastward through south-central AL into central and south-central GA this morning.  The strongest of these storms are on the eastern edge of this cluster, and are producing some hail.  As the day wears on and moisture and instability increase south of the MCS, I would expect some of the storms to become surface-based, especially those along the south edge of the cluster across south GA, and any discrete cells that should form in the increasingly unstable airmass across south GA and north FL.  Helicity values will certainly be high enough to support some rotating updrafts across south GA and north FL this afternoon and evening, and an EHI maximum above 2 exists across southwest GA at 00z off the 06z NAM. This environment could be supportive of a few isolated, brief tornadoes of EF0 and EF1 intensity.

STORM CHAE TARGET:  Georgetown, GA to Albany, GA to Waycross, GA to Brunswick, GA to Jacksonville, FL to Tallahassee, FL to Georgetown, GA.

Then there is the cold and snow aspect of this system, which will be significant across parts o the Southeast.

This is going to be a fairly long duration upslope snow event for the mountains of eastern TN and western NC. The upslope snow machine will kick in around noon on Monday and continue until late Tuesday night. Snow levels start out above 4,500 feet, with snow levels dropping through the day and into Monday night , with snow increasing. By Tuesday morning, snow levels will have reached the valley locations. I think 5 to 10 inches of snow above 4,500 feet looks quite possible by Wednesday morning , with most locations in the 5 to 8 inch range. Between 2,500 feet and 4,500 feet a good 3 to 6 inch snow is likely. Below 2,500 feet across western NC a trace to as much as 3 inches appears likely. The mountains of north GA and the upstate of SC will also get in on some snow action Monday night and Tuesday morning, with elevations above 3,000 feet picking up 1-2 inches, and between 2,000 and 3,000 feet getting a trace to 1 inch. There will also be a slug of 700mb moisture dropping down as far south as I-20/I-85 in GA between about 4am and 9am on Tuesday. This could create flurries in the air as far south as Atlanta! Finally, a hard freeze looks likely along and north of the i-20/I-85 corridor across northern and central AL, GA and SC by Tuesday morning. As has been the case so often in recent years, the peach crop in this region is in jeopardy.