Archive for winter storm

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!

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 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.

An Wild Weather Weekend for the Southeast with Severe Weather and Significant Snow Likely!

Posted in Extreme Weather Video, Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , , , , , , on February 27, 2009 by stormstream

All systems are still go for severe thunderstorms, then snow across parts of the Southeast this weekend, and we are now getting into a range where I can throw out some more specific forecasts with some measure of confidence.

First, I’ll discuss the severe weather prospects for Saturday and my plans to chase the storms and do a live internet broadcast of my storm chase.

It is hard at this point to say exactly where the greatest threat for severe storms will be on Saturday.  The models are pretty much showing the area in Georgia and eastern Alabama along and south of I-20 as being in the threat zone.  However, I’m not sure the models are handling the effects of the large convective system over central AL and GA very well.  Surely this will reinforce the boundary farther south than the models indicate.  Right now, I’m thinking along and south of  line from Macon, GA to Troy, AL will be my target for severe weather on Saturday.

Steep lapse rates, rather low freezing levels, and the potential for rotating updrafts will lead to very real possibilities of large hail.  Also, the shear, divergence aloft and strong 250mb winds will lead to the chance for long-tracked supercells with a chance for a few tornadoes.

The plan right now is for me and my chase partner, Greg Zamarripa, to depart Atlanta at 11:30am and head for either Columbus, GA or Macon, GA as a base.  We will then head out in any direction from there to intercept storms.  We hope to be in our target by 2pm EST.  Storm chaser Mark Aubin will be targeting the Florida panhandle for any severe storm activity that erupts farther south.

I will be broadcasting my storm chase live on the internet on Ustream.tv and Severestudios.com.  Between 11:30am and 3pm I will be streaming live at http://www.ustream.tv/channel/mike-phelps-mobile-weather-stream.  Then, from roughly 3pm EST onward I will be streaming live at http://www.severestudios.com/livechase as Mike Phelps.  On the ustream.tv broadcast the viewer will have the ability to not only view the live video, but also hear audio from within the chase vehicle.  You’ll be able to listen in on critical nowcasting conversations and storm chase strategies, so you’ll actually feel like you are riding along with us on the chase.  There is also a chat feature where you can interact with me via instant message, and I can talk to you live.  The severestudios.com broadcast will not feature audio, but the video could be spectacular at times since we will be streaming at that location during the height of the storm chase.  I will be available to the media for live phone interviews any time at 404-202-6317.

Now onto the snow prospects for Sunday.

This looks to be a classic late winter/early spring upper level snow events for parts of the Southeast.  The upper low drops in from the northwest bringing with it a supply of moisture, cold air and strong dymamics.  These events are notoriously difficult to forecast and the area of heavy snow that falls will be dictated very much by the exact path the upper level low takes.  Right now, I’d say a general trace to 3 inch snowfall looks like a good bet across TN, northern and central AL and GA, much of SC and much of NC.  1 to 3 inches for Memphis, Birmingham, Huntsville and Chattanooga.  1-2 inches for the west Atlanta metro area, and 2 to 4 inches for the east and northeast ATL metro.  3 to 6 inches for Athens, GA.  4 to 7 inches for Greenville, SC.  I won’t venture to throw out a snowfall forecast for Columbia, Charlotte or Raleigh just yet, but they could also make out very well.  I also believe someone in the Southeast is going to see some “jackpot snow”of a foot or more, but it is impossible to pin down who that will be at this juncture.  I hope it is my backyard!  🙂  Now having said all that, I do need to caution that the bust potential with upper level snow systems in the Southeast is very high.  Honestly, we are not going to have a fully confident handle on this thing until it is happening.  The cities I listed above could just as easily end up seeing a lot less, or a lot more.  Definitely a system to monitor closely as there are sure to be several changes in the forecast over the next 24 to 36 hours.

I will also be streaming live video of the snow storm, and I will have more details on that in my blog entry Saturday evening or Sunday morning.

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.