Archive for snow storm

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.

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Blizzard Conditions Expected Tonight in the Tennessee and North Carolina Mountains. I’ll be Broadcasting Live on the Internet from that Location!

Posted in Extreme Weather Video, Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on February 3, 2009 by stormstream

I will be broadcasting live from the location of the snow storm this afternoon and tonight.  You can view my broadcast live on the internet at http://www.ustream.tv/channel/mike-phelps-mobile-weather-stream.  When I am not streaming you will see a slide show of my weather and nature photography.  The main broadcast time today will be between 3pm and midnight, although I will be streaming my drive to the location as  well, and that will be between 11am and 3pm EST.

A strong upper level disturbance combined with a moist upslope flow will cause snow across the mountains of eastern Tennessee and western North Carolina to increase after noon today, and become heavy toward sunset.  Wind and heavy snow tonight will create blizzard conditions on the mountain tops.

Total snow accumulations between now and Thursday morning will be 2 to 6 inches at elevations below 2,800 feet.  Elevations between 2,800 and 4,000 feet will see 4 to 8 inches of snow, and elevations above 4, 000 feet will see 6 to 10 inches.  Some of the favored west-facing slopes at 5,000 feet and above elevation could see a foot of snow, combined with 50mph wind and wind chills of 20 below zero tonight.  Truly blizzard conditions.

My plan to intercept this major winter storm is to head north on I-75 to I-40, then take I-81.  I’ll then take I-26 eastward to Johnson City and make a final plan to either target Roan Mountain, TN or Beech Mountain, NC.  The plan is to be in the target area by 3 or 4 pm EST.

Significant Upslope Snow Event for the Central and Northern Mountains of North Carolina and Tennessee

Posted in Severe weather, Winter weather with tags , , , , , , , , , , , , , , , , , , , , , on February 2, 2009 by stormstream

There’s not too much to say about today’s non-system that hasn’t already been said, so I won’t waste any more time talking about it.  I will say that I would not be surprised to see an inch of gloppy, wet snow on the Cumberland Plateau this morning. I’ve driven up to the rest stop on I-24 in Monteagle, TN several times in situations like this, and been rewarded with some nice snowball-making snow.  And as for the second short wave, the clipper, that earlier looked like it could possibly provide parts of the Southeast with a dusting of snow on Tuesday night, well that now looks to provide only some light rain and snow flurries Tuesday afternoon, but will be a major factor in fueling the system that the majority of this blog post will concentrate on.

The cold front moves across the region today.  Light snow will overspread the mountains of eastern Tennessee and western North Carolina, and provide an inch or two of snow for locations above 2,800 feet.  Not a big deal.  The big deal comes Tuesday afternoon and night.

A winter storm watch is in effect for the following counties in the mountains of western North Carolina from Tuesday afternoon through Wednesday afternoon:  Avery, Madison, Mitchell, Madison, Yancey, Haywood, Swain, Buncombe, Graham, Ashe, Watauga, Grayson, northern Jackson, Caldwell mountains, Burke mountains and McDowell mountains.

During the day on Tuesday the upslope flow becomes firmly established across the mountains, and snow shower activity will steadily increase through the morning and early afternoon.  As the afternoon wears on an upper level disturbance will swing through the region and enhance the snow, as well as produce some wind.  That is when things get really interesting for especially the central and northern mountains of TN and NC, and especially west and northwest facing higher slopes.  Snow showers will increase to intense snow squalls and the wind will increase, producing low visibilities and blowing and drifting snow.  This will all generally be after about 2pm, and lasting through Tuesday night.  After that, the disturbance passes, and just general light to moderate snow shower activity will continue through the afternoon on Wednesday before coming to an end around sunset on Wednesday.  When all is said and done, elevations above 2,800 feet in the central and northern mountains of NC, and TN mountains along the border with NC, will have a general 3 to 6 inches of snow on the ground, and the ski resort elevations above 4,000 feet could see up to 8 inches, and possibly more than that in the most favored upslope regions.   Beech mountain, Sugar mountain and Wolf Laurel should make out very well with this event, so skiing will be back in full swing for the TN and NC ski resorts through the upcoming weekend.

Just a quick mention about the cold weather, then the warm up and severe weather chances that I mentioned in my blog yesterday.  We are definitely still on track to see some cold weather Tuesdsay and especially Wednesday.  Lows in the ATL area could drop into the 20’s with teens outside the city, with highs only in the 40’s on Tuesday, and possibly not making out of the 30’s on Wednesday.  Then starting Thursday the warm-up begins, and we are into the 60’s by the weekend.  In fact, this looks to be an awesome weekend coming up for any outdoor activities.  Heading into next week there are still some indications that a pattern that could favor some intense thunderstorm activity for parts of the eastern half of the nation could evolve by the middle or end of next week.  There is no way to be any more detailed than this right now.  This will be something that I’ll be monitoring, and as details come into better focus, I will certainly pass along my thoughts on this, but that probably won’t be until early next week.

Winter Storm **UPDATE**

Posted in Severe weather, Winter weather with tags , , , , , , , on January 31, 2009 by stormstream

I normally don’t post and evening update, but there has been so much concern over what the models are showing today in regards to the system for early next week, that I felt compelled to post some thoughts.

First off, and this needs to really be stressed and understood, the energy in the atmosphere that is going to be the catalyst for this storm hasn’t even made it to the lower 48 yet. It is still out over the data-void Pacific. So, until this energy makes it over the U.S. and can be sampled, the models are not going to be all that reliable. I am seeing people embracing various model runs like they are the be all, end all models for this storm that hasn’t even formed yet. I am perplexed and somewhat amused by this.

I am certainly not saying that the models should be ignored until the energy makes it to U.S. atmosphere. There are definitely some trends that can be noted and used as possible predictors of the future of this system. The most notable trend today has been for a weaker, non-phased system that tracks farther south than models were indicating yesterday. Given the current look of the mid and upper levels and what is happening upstream and downstream of the Southeast in the atmosphere, I’d say a weaker, non-phased system looks reasonable at this point. I am, however, having difficulty buying into the extreme southerly track shift indicated by the NAM, and especially the 18z GFS. Track is difficult enough to be forecasted by the models 24 hours in advance, let alone 72 hours prior. And track is something that really cannot be determined very accurately without the benefit of sound, real-time data, which this system does not have yet since it is still out over the Pacific ocean. So, a weaker system that is not phased takes the storm out of the major winter storm category and places it in the normal winter storm category. Still a winter storm that is sure to cause some problems across parts of the Southeast, but not one that goes down in the history books as a really memorable or historic event.

Until the system gets better sampled and a true and substantiated track forecast begins to emerge on the models later tomorrow into Sunday, I will not change my thinking on where the most significant snow will fall. I will still say that significant snow of 3 inches is possible across central and southern AR, northern MS, much of TN, northern AL, northern GA. South of that to the I-20/85 corridor, I will continue to go with a possible accumulation of a trace to as much as 3 inches. I am not so sure about the certainty of a major snowfall in the mountains of NC and TN, so right now I’ll revise my thinking downward on that into the 4 to 8 inch range, instead of the foot or more that had been my previous thinking.

Something else that has emerged on today’s models is the chance for a fast moving upper impulse zipping across the Southeast Tuesday afternoon through Wednesday morning. If this happens it would bring a burst of snow lasting about 6 hours. Given the air mass in place it would fall as all snow, and the ground would be cold, so there would be no initial melting. Also, ratios as high as 15 to 20 inches of snow to one inch of water equivalent could yield an inch or two or maybe even three of fluffy powder for those under the fast-moving area of snow. Definitely something to watch.

All in all I would just advise the snow hounds of the Southeast to remain calm and patient and wait until Saturday night or even Sunday before buying lock, stock and barrel into a forecast model solution, especially in regards to track of the storm.

Major Winter storm WILL Impact Parts of the Southeast Next Monday and Tuesday

Posted in Winter weather with tags , , , , , , , , , , , , , , , , , , , , on January 29, 2009 by stormstream

I normally do not make such a declarative statement so many days in advance of a weather system, but based on my thoughts on how the weather pattern would evolve all month, and based on overwhelming model support, I feel 100% confident in saying a high-impact winter storm will affect parts of the southeast on Monday, February 2 and Tuesday, February 3, with the worst of the storm happening in the noon Monday to 6am Tuesday time frame based on current models.

Of course nothing is set in stone with this system, and much can change between now and Monday.  The most likely things to change would be the strength and track of the surface low pressure system.  These changes, even if slight, can and will translate into major changes in the forecast since the synoptic heavy snows associated with the low pressure system are likely to be confined to a rather narrow corridor.  So, pinning down exactly where the heavy snow will set up this early in the game simply cannot be done with any kind of accuracy.  Sure, someone could throw a forecast out there, and they could very well get lucky and have it verify, but it would truly be a case of “skilled luck” as I call it.

In general terms, the areas that are most likely to see snow Monday would be northern MS, western and middle TN, northern AL and northwest GA.  On Monday night and Tuesday morning the snow would affect the remainder of north GA, the upstate of SC, eastern TN and western and central NC.  The central and northern mountains of TN and NC look particularly interesting as they could see a burst of heavy synoptic snow early Tuesday morning, then a prolonged northwest flow upslope event that lasts from Tuesday morning to Thursday morning that will add to their snow depth.  The ski resorts will be loving it by next weekend.

Finally, there will likely be a severe thunderstorm component to this system.  A severe squall line with damaging winds being the main threat could sweep across southeast AL, southern GA and much of FL Monday afternoon through Tuesday morning.  Depending on the track of the surface low, central and eastern South Carolina and eastern North Carolina could get in on some severe storm activity as well.

Many more finer details regarding this storm will come into focus this weekend, so keep checking in for my latest thoughts on this major system.