Archive for winter

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.

Severe Storms in Central Georgia Today, and Heavy Snow Possible Sunday. I’ll be Storm Chasing Today and Sunday.

Posted in Extreme Weather Video, Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , , , , , on February 28, 2009 by stormstream

STORM CHASE STATUS: ACTIVE

TARGET: Central and southwest Georgia and southeast Alabama.  Macon, GA to Columbus GA to Troy, AL to Panama City, FL to Valdosta, GA to Macon, GA.

TIME: Depart Atlanta at 11:30am EST.  Arrive in target by 1pm.  Actively storm chasing until approx. 9pm.

LIVE INTERNET BROADCAST: 11:30am – 3pm at http://www.ustream.tv/channel/mike-phelps-mobile-weather-stream (live video and audio) 3pm-9pm EST at http://www.severestudios.com/livechase.  Chasing as Mike Phelps.  Live video only.

AVAILABLE FOR LIVE PHONE INTERVIEWS: 2pm – 9pm EST via mobile phone at 404-202-6317.  Leave message on voice mail and I’ll call right back.

DISCUSSION: A warm front stretches west to east across central Georgia this morning.  This front should remain in this general area through the afternoon and will provide a corridor of increased low level helicity that could be a breeding ground for a few tornadoes.  I don’t think we will want to stray too far south of that warm front today.  Dewpoints in the mid 60s have moved into south-central Alabama this morning, and will continue to spread across southeast AL and into portions of southwest GA and the western FL panhandle this afternoon.  All models indicate a broken line of supercells developing along and ahead of an advancing cold front from central GA into south-central AL after about 3pm today.  These storms will have the potential to produce large hail and damaging winds, and in that corridor of higher helicity near the warm front there will be a threat for isolated tornadoes.  There is a CAPE and EHI max that has been showing up now on a few runs of the NAM so I believe what we will do is head southwest from ATL on I-85 and establish a base of storm chase operations in Columbus for a while and then adjust locations from there.

WINTER STORM DISCUSSION: Forecast models remain consistent in showing an upper level low snow event across parts of the Southeast starting later today in the Mid-South and spreading south and eastward across Dixie tonight through Sunday.  This is a very dynamic system with good moisture associated with it, and the potential certainly exists for some heavy snow.  The last couple of runs of the NAM have taken the upper low on more of a southerly route over what it was showing this time yesterday, although the 06z NAM shifted north again.  If this track comes to fruition then a swath of significant snow (3+ inches)  will extend from Memphis, TN to Birmingham, AL Atlanta, GA to Greenville, SC and northeast from there.  It is very difficult to pin down the exact location of the heavy snow in these upper level low snow events this time of year, so who is to say that the area I outlined above will ultimately verify, but we are gaining more and more of a consensus among the models that this track of significant snow is becoming more likely.  In my opinion, there is still the potential for this system to produce some “jackpot snows” on the order of 5 to 10 inches, but it remains impossible to pin down the location for that.  I want to strongly caution that certainly nothing is set in stone with this system as of yet.  There is still a rather sizeable potential that it will end up being far less of a big deal than a lot are anticipating.  Keep in mind that snow outside of the state of North Carolina and the mountains of Tennessee, has been basically non-existent this winter.  La Nina winters simply do not breed big snows outside of those areas.  Also, the forecast models have been less than stellar in their performance this winter.  Honestly, we are not going to feel real confident about any snow forecast with this thing until it is actually happening.  So, watch the system closely, but don’t be quick to jump onto any snow or non-snow bandwagons until the wagon is actually passing through your area.

If this system produces significant snow near Atlanta, GA on Sunday then I will be broadcasting it live on the internet.  I’ll have details about this live broadcast in my Sunday morning blog.

Severe Thunderstorms, then Snow this Weekend for the Southeast!

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , on February 26, 2009 by stormstream

A wild weather weekend is in store for the Southeast from Friday through Sunday.

On Friday, the stage is set for a severe weather episode across central Mississippi into central Alabama.  Hail and damagaing winds look to be the biggest threats, but there will also be the threat for some tornadoes as well.  If dewpoints reach the 63-67 degree F. range, then even a strong tornado or two will be possible along and just north of I-20 in MS and AL on Friday afternoon and evening.  By early evening the threat for strong to severe storms will extend into parts of western and northern Georgia.

On Saturday, the main threat for severe storms will extend from central and south Georgia into the upstate of South Carolina and central and eastern North Carolina.  Instability will decrease, while upper level dynamics increase.  Overall, the threat on Saturday does not look as great as that on Friday, but nonethelesss, damaging severe thunderstorms will be possible, especially across central GA, and an isolated tornado or two cannot be ruled out.  I may be streaming severe weather video at http://www.severestudios.com/livechase.  If I do, I’ll be sure and let everyone know.

Saturday night through Sunday and even into Monday morning is looking VERY interesting in terms of significant snowfall.  Yes, it does snow in March in the Southeast, in fact, some of our biggest snowfalls happen in March.  this will be a fairly long duration upper level low snow event IF it pans out.  These are notoriously hard to forecast and pin down the areas of greatest snowfall accumulation until the event is actually unfolding.  These events are also notorious for “jackpot snows”, where someone in a small area or narrow swath gets absolutely crushed by heavy snow.  We had one of these early in the season across southern Louisiana into southern and central Mississippi.  I won’t get specific yet, I’ll just say that significant amounts of wet, gloppy snow will be possible across northern and central MS, AL and GA, southern TN, much of SC and central and eastern NC.  Could this threat fizzle like so many have this winter?  It sure could, so it will be important to keep an eye on the forecast and not get too carried away just yet with this threat in any direction.  We’ll know much more about the potential snow threat and more specific details by Friday night and Saturday morning.

Still a Little Snow Possible in Dixie This Weekend, But Not Much

Posted in Winter weather with tags , , , , , , , on February 19, 2009 by stormstream

My thoughts and prayers are with all of those impacted by yesterday and last night’s severe weather.

The forecast models still indicate a chance for light rain changing to a period of light snow across TN, north MS, north AL and north GA this Saturday into Sunday morning, but the trend is for less moisture and less cold air.  So, that translates into some flakes, but nothing that is going to add up to a whole lot.

I think most areas north of I-20 could see a brief transition to some light snow through the day Saturday and Saturday night.  No accumulations except for a dusting to an inch across the higher elevations of northeast AL and north GA.  TN could make out a little better with 1-2 inches possible for the Plateau, and 1-3 inches for the mountains.

It’s too early to say if this is the last chance for significant wintry precipitation across the Southeast, but we are getting really close to officially pulling the plug on winter down here.  It really is starting to look and feel a lot more like spring.

Tornadoes Possible in Dixie Today. Snow Likely on Saturday. Get Ready for a Wild Few Days!

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , , , , , , on February 18, 2009 by stormstream

It is going to be a classic wild weather ride across the Southeast United States over the next several days.

A storm system today and tonight will bring the potential of severe thunderstorms across a good portion of LA, MS, AL, GA and north FL.  The threats with these storms will be large hail, damaging winds, and tornadoes.  In fact, the tornado threat is looking rather significant for the southern half of MS, and the southrn 2/3rds of AL.  Also, if mid 60 degree dewpoints make it into GA this afternoon, then a significant tornado threat would also exist for areas in GA along and south of interstate 20, and this would include the Atlanta metro area.

Overall, the potential violence of this event will very much be dictated by the degree and depth of moisture across the Southeast.  As of late morning, many dewpoints in the threatened areas of AL and GA are only in the low to mid 50s.  Dewpoints will need to rise into the 63 to 67 degree F. range to provide the sufficient low level moisture to fuel robust and deep convection necessary to produce tornadoes.  This will be a situation where the true potential of this event may not be fully realized until mid to late afternoon today.  There are still several factors that could significantly limit the overall threat and only time will tell whether those factors will go away or remain.  So, it will be very important for those across the Southeast to stay up to date on the latest weather information as the day progresses.

Now for the winter weather threat fro Saturday into Sunday morning…

This threat has been on the models for several days, and is trending stornger with each model run.  I am very hesitant to take the bait on any model threat beyond two or three days given the poor performance of the forecast models in this range this season.  I will say that I am cautiously opitimistic that a swath of light snow will progress from northwest to southeast across areas mainly along and north of I-20/I-85 Saturday into Sunday morning.  Accumulations could range from nothing to a dusting, to several inches.  It is just too early right now to say much more than state that this is a potential winter weather threat.

The Most Active Active Weather of the Winter Season for the U.S. as Three Storms Impact the Nation Between Now and the End of Next Week

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , on February 6, 2009 by stormstream

A very active weather pattern will grip the nation next week, leading to a variety of nasty and potentially dangerous weather.

Each of these weather-makers will enter the western U.S. and move across the country bringing rain, snow and even a threat of strong to severe thunderstorms with them.  Storm #1 affects the country between today and next Tuesday.  Storm #2 impacts the U.S. from next Monday through next Thursday, and storm #3 move across the U.S. between next Wednesday and the following Monday.  As you can see, there is a lot of overlap in terms of the days that storms will be impacting the U.S., so this will mean that many parts of the country will be affected by high-impact weather at any given time.  A very, very busy period for sure.

Severe thunderstorms will be a concern across areas of extreme southwestern KS, southward across the TX panhandle and western OK, very late Sunday afternoon, but more likely Sunday evening.  These storms then spread rapidly eastward and northeastward to affect southern KS, the remainder of OK and north TX Sunday night and early Monday, then into the MO and MS Valley in a weakened fashion during the day on Monday.  Overall, this does not look to be a major severe weather episode.  As is often the case with these early systems, quality moisture return from the Gulf of Mexico will be lacking.  However, the strength and dynamics of the system should be enough to overcome the lack of deep, quality moisture, and still develop some severe storms.  Damaging winds would be the main threat, with some hail as well.  Even though shear is more than adequate to form supercells, I just do not see a real good chance for deep convection and robust updraft development with any discrete, early storms, so the tornado threat is rather minimal.

The first system will not send a front into the Gulf to keep moisture at bay.  In fact, the pump will be primed so-to-speak by the first weather system, and the second one following close behind it should have an easier time pulling better quality moisture up from deeper in the Gulf and western Caribbean.  Even still, however, this will not be the quality of moisture we will see drawn northward later in spring.  So, the system affecting the central and eastern part of the country will have more Gulf moisture to work with, and this should translate into a greater chance for severe thunderstorms, as well as heavier snowfall in the cold sector of the storm.  Right now it appears the greatest threat for severe storms will be across the eastern Plains, the MO and MS Valley during the day on Wednesday, then the  TN Valley and remainder of the Southeast Wednesday night into early Thursday.  The northward extent of the severe threat is still rather uncertain, but the areas I mentioned have the best chance.  Greater moisture, higher instability values, and strong dynamics will lead to more vigorous thunderstorms.  Shear will again be adequate for supercells and a few tornadoes, however, the quality and depth of moisture return will not be at a level that would lead me to believe we are looking at any kind of outbreak of tornadoes.  This looks to be a fairly widespread threat for storms with damagaing wind and hail, but tornado activity will be isolated.  However, I caution thatit is still early and this forecast could change for the worse if better moisture and instability than forecasted should develop.  So I advise everyone across the eastern Plains, MS/MO Valley, eastward to pay special attention to this system next week.  In addition to the severe thunderstorm threat with this system, it also appears there will be a stripe of wet, heavy snow and wind to the west and north of the track of the surface low in the cold sector.  The ultimate location and track of this low is still very much in question, so at this point I’d say anyone from parts of OK and KS north and northeastward could be impacted by some nasty winter weather.

Finally, the third system in the next Wednesday to the following Monday time frame appears to be more of a winter storm threat for much of the country, as the second system will usher in colder air to a farther south latitude.  However, a threat for strong to severe storms will exist as well, generally along and south of I-20 from Texas into the Southeast U.S.  The Rockies to the Plains and all the way to the Mid-Atlantic and Northeast could see quite a snow storm.  The limiting factor for this system in terms of both snowfall and severe weather will be just how much moisture is robbed by the second system, and how much moisture can make it back to feed the third system.  When you ave three successive systems affecting the country in such a short amount of time, available moisture for them to work with is always a major question mark.

This definitely appears to be the most active period so far this winter with a wide swath of the nation impacted by inclement weather conditions.