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Everything posted by Carvers Gap
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It has been a good seven years. Happy Birthday, TN Valley Sub-Forum!!!!! In honor of this, I am bumping a seven year old thread!!!! LOL. May there be many more. Truly one of the best places on the internet.
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December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
The 18z RGEM(beginning at hour 60) implies that there may be some slick spots during storm #2 in valley locations. Not sure I buy it, but is definitely on the model. Cold is quickly scoured out, but it does imply that there may be initial ice or mix north of 40 and along the I-81 corridor. I am absolutely not calling for that, but just wanted to give it a mention. Don't see a lot of evidence on other modeling, but the RGEM has been decent in recent years. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
I do think WxBell is a bit generous with its snow algorithms on the 3hr and 6hr maps. Here you go for middle and west areas of the subform...Also, nice look for areas of SE KY and SW VA. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Euro 12z WxBell snow algorithm definitely showing snow showers for much of west and middle TN for storm one. Storm two - rainer...though extreme NE TN/SW VA is not written in stone for this one yet I don't think. If DC is getting a good track, sometimes TRI can get in on that. Anyway, storm one has anywhere between. .5 - 2" from a line from Memphis to the northern Plateau. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Yeah, I normally like seeing storms underneath. Always think the NW shield delivers, even if marginally. I was wondering why that wasn't showing up. Looks like the slp is a bit deeper. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Saw the same thing and laughed. Bout the only positive from that which I see, is that it must be cold for it to snow that far south....plenty of time for that to trend NW, right? -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
CFSv2 heads to colder phases which is likely why it is so cold. Definitely was a bias of this model last year, BUT it is not an unreasonable option. It also illustrates where the pattern "could" go if the MJO were to head to 7, 8, and 1. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Bout the only thing I have tonight after looking at a very boring set of ensembles and operationals going out to two weeks...the MJO has surged into phase 4. The CA OLR map really looks like the MJO is heading for phases 7 and 8 after that. So, this may sound weird, but I sort of want the MJO to gain a bit of amplitude and rotate on around - looks like a real possibility. That would imply the PNA(which we are seeing return on some LR modeling) might be a factor in a couple of weeks - when it is great climo for cold. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Now, what the EPS is cooking up at lunch will play. PNA ridge after 300. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Just looking at the LR, really nothing new. There are some hints the Pacific may get its act together during the first part of January - CFSv2 extended. The run of the GEFS extended breaks down the pattern in early Jan, but then WxBell stops the run. WxBell has been really "buggy" for the past few weeks. For you all using pay sites, who are you using? I am not unhappy with WxBell, but if the site continues to be buggy I will take my business elsewhere. I think we are going to have to have a resupply of cold air if we are going to get a forum wide storm at lower elevations. Though currently, the 0z CMC and 6z GFS do imply ice for NE TN for the second storm. Holston, that second storm indeed looks like a Miller B on some models and those usually bring rain to the forum area. For the models which don't have energy transfer(or have less), NE TN sees ice or snow or both. Not sure I buy ice here (at least for extended amounts of time). We do get light icing at times if the storm moves in during an inversion, but that usually gets scoured before serious damage is done. Models often make the mistake of bleeding cold air into the TRI from the NE when the mountains usually just won't allow it. Sometimes it can get to Abingdon, but that is about it. I will add that when DC gets in the slot for snow, often snow accumulations will begin in NE TN and work NE into the Mid-Atlantic. So, for the extreme NE TN corner...these have to be watched. Just depends on how quickly that low gets its act together. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
@John1122, we have even had snow during mid-early December. I think twice during the last 11 years, 09-10 and a couple of years ago. I think the December snow days a couple of years ago were Kingsport's first in nearly four decades(could be more). Those were both really big snows. I think you have noted that early season storms seems to be the trend of late. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Starting to become more of the opinion that we are going to need another strong cold shot of air into our region. Marginal systems at this time of year at lower elevations and at this latitude are just tough to get much mojo from. That said, within the next two weeks, we get to much more favorable climatological norms, and that helps. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
12z EPS much better looking this run d10+ with a small PNA ridge and NAO block. We can live with that. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Not sure if it is the WxBell algorithm, but it has snow for the first system over SE KE, the Plateau of TN, and SW VA, and the Smokies. 2-3" of snow on the Plateau. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
The 12z CMC is close to a big storm for Weds in this area...very big for MA and NE. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
And to quote a famous poster of the TN Valley..."When we start talking about the MJO, that is usually not a good sign." -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Thought I might take some time to look at why we are seeing some variability in modeling in the long range this morning. Grabbed the CA OLR map (outgoing long wave radiation). The cooler areas on the map indicate higher cloud tops and signal more convection(t-storms). The first image is the CA(constructed analog) OLR map. You can see the IO (Indian Ocean) go very quiet as the wave propogates(moves) from the MC to the dateline. As a quick note, the MJO's favorable phases for winter weather are near the dateline(180). So, days 11-15 would see the MJO move into phase 7(and maybe even 8,1) which is colder in NDJ (DJF is warm). So, the phase 7 is sort of in-between the DJF and NDJ by late month, and that causes a washed out signal since one three month analog is warm(DJF) and the other is cooler (NDJ). The second map is from the GEFS. The OLR there is locked into the MC(Maritime Continent) for the foreseeable future. How modeling is handling the Indian Ocean and the MC is not consistent among different models IMHO. Some models are taking the MJO through 4 to 5 to 6 and one would guess...7. The EMON rotates through the circle of death. The CA rotates at higher amplitude to 7. The GEFS stalls the MJO. In other words, models are all over the place with the MJO. Take one look at the 500 maps for the major ensembles this AM, and you will see the model spread. All of that said, we "might" see a more conducive Pacific later this month or even by January. As I noted yesterday, if we can use the -NAO to bridge to the a better Pacific set-up later on...we might have a chance to stay seasonal(or slightly above) until the next legit cold shot - and that is a win if we like winter. Why? Normal or even slightly above will get the job done later this month. Right now, I don't think I buy much after d15 - cold or warm. I would say my confidence level is low. If forced, I would say we will continue to see weaker heights over the SE for the foreseeable future with some ridges rolling through. I do think there is a chance (if the -NAO verifies and we get even a temporary PNA or EPO) that we could see some colder temps rotate through. I think the problem right now is the Atlantic block is muting what would otherwise be a total torch. Computer models, like humans, are trying to figure out how much of an influence that block is going to have. At the very least, we are going to likely see an active and stormy patterns with cutters and some Miller A(with marginal cold...increasingly colder as December averages take hold) stuff. References: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml (CA stuff) https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/ (phase correlation map of MJO to NA wx per three month increments) https://www.climate.gov/news-features/blogs/enso/what-mjo-and-why-do-we-care (phases of MJO by longitude) https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml (various model output for the MJO) -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
On a positive note, the CFSv2 Seasonal(not the CFS extended) this morning flipped cold for January. No idea if that holds in future runs as it bounces around, but it has been solid in the warm camp for January for some time. One thing to watch for is that the GEPS has shifted (around Christmas) the AN height field into Nova Scotia vs Greenland - looks temporary but that would pump an EC ridge if true. Again, I really don't like losing the EPS in the LR as it has reverted back to its original warm solution along the EC around Dec 21 which is just three days later than the steadfast runs of the week before(never ending warm). And again, it is holding a low in the Southwest which is often a miserable error that it often repeats. American modeling is colder(surprise!) while other modeling has backed-off the nice 500 pattern in varying degrees after the 20th. Could just be a wobble...time will tell. Last winter has me gun shy. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Not a fan of where the 0z EPS went last night in the LR. I really hate playing the "low gets stuck in the SW" game with that model. Huge bias, but sometimes it is right. Most other modeling looks good in the LR, but EPS makes me a bit nervous. As for the Monday system, same playbook as the last system on almost all modeling, and I am not sure why that happens - massive NW shift. Now, lets' see if it doesn't start coming back SE later tonight and tomorrow. If we get snow, looks like the Plateau would be the spot. NE TN is out of this one unless it goes eastward - and I am not ruling that out. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
WxBell algorithm. About as marginal as one could get. SLP is slightly NW of 0z. If it goes like the other system...will trend NW a few more runs and then jog SE quite a bit and back a tick NW. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
WxBell has snow north of 40 - heavy on the Plateau. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Since I have been doing this as a hobby, I am not sure I can really remember tracking many -NAOs. LOL. I have lived through -NAO winters, but have not tracked many. Pretty much anything is better than last winter's tracking options. For real, how many -NAO winters have we had since 2000? -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Yeah, I noticed on some OLR maps that the warm phases near the MC don't have high cloud tops in the LR which would likely mean less convection. Also, the MJO looks like it may rotate quickly through 6(edit) and is aimed directly at 7. If we can rotate through 7, 8, and 1 during late December, that would be cold I think. During a normal winter, I almost never really worried about snow prior to Dec. You Plateau folks have different benchmarks! LOL. As a kid, I pretty felt like a 1-2" snow(in Knoxville during the 70s) was expected before early Jan. I think this year with so many warm analogs(though once small cluster is very cold), folks feel like we have to get winter before mid Jan...and they may be right. That said, it has been a while since we have had a cold winter. So, we are sort of due. But I will gladly take what the Weeklies are dishing out....well, until they get warm in mid Jan. The torch on the Weeklies has been pushed back almost three weeks now. Small victories! -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
Can kind of see the block at work there. Looks like the system near Jacksonville slows and gets caught by a trailing piece of energy...then mini-boom phase. Many Kocin storms have -NAOs. You folks on the Plateau benefit far less with Atlantic blocking and do much better with Pacific. We get a lot of Atlantic feed up here as you know. If we didn't, I think we would be an almost arid region. John, what would be awesome is if the NAO can carry us until the Pacific gets a bit better - could bridge us between early December and mid-Jan. -
December 2020 Medium/Long Term Pattern Discussion.
Carvers Gap replied to John1122's topic in Tennessee Valley
I think with pretty vigorous winter storms, it is super common to have something go west of the Apps. Just want the lion's share east.