Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 18 minutes ago, Blue Moon said: I noticed the whole Southeastern and NE Megalopolis regions were shut out from snow on the Euro's 12Z 240 hour run. I only glanced at it today but I made a quick inference that temps may be AN for the East Coast to kick off Jan. Yeah, I think the first two weeks of January just after the New year(barring a thread the needle situation) have flipped warm. That said(and I really even hate saying this, because if I had a nickel...) in about 14 days, the 18z GEFS is showing a workable pattern. Trends have been pretty good this afternoon. Need to see those moving forward in time and increasing in relevance as they get closer...I can't do the backend winter deal from the past two years where we waited, and waited, and waited. This could be a pattern change or just a relaxation of the pattern from December. I simply don't know. This morning I would have said pattern change...now maybe more like a pattern relaxation. Some great SSW posts this morning - that event will have a big say so going forward. Lots of uncertainty from mid-January onward. The MJO is going to fight anything good for the East. The -NAO should win from time-to-time. However, not having cold in Canada is a major problem. Like a broken record, I say this every year. Some truly great winters never got going until mid-January. However, Nina climatology will very likely make sure the Mountain West scores this winter. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted December 28, 2020 Share Posted December 28, 2020 10 hours ago, Carvers Gap said: Maybe those ensembles are "feeling" the strat split now? You may be on to something. The 0z GFS shows how that could be the case, or maybe they are seeing the end of the Pac jet extension. The 500 mb anomaly map reminds me of the sorts of progressions I saw yesterday when making those gifs for NA's pattern after a SSWE, although it seems a little early to me: No real ridging over AK, but not real troughing either. Just kind of a relaxation of the flow there. Probably doesn't hurt that the Greenland block meander's westward too. I wish I understood more about how these things percolate down in the atmosphere. Here is the 0z GFS's depiction of the strat geopotential heights at at 10mb (using the GFS for these because it's A. easier for me right now and I have access to more of it's layers of the atmosphere and B. it's all out in fantasy land, so might as well use the GFS): 50mb: How that corresponds a bit lower down to winds at 100 mb: and 250 mb (over just NA because weathermodels doesn't offer a 250 mb N pole view): That Pac jet is like a whip, throwing off pieces of energy at us. But it kinda quietens down, at least to my eye, towards the end of that gif. But it is hard for me to see exactly how the strat is impacting the trop. Maybe some of you can see something in those gifs I'm missing. Just looking at the MSLP anomalies, it makes me think that maybe this big cyclone in the N. Pac, in part triggered by the descent of the Siberian high, has to run its course too, before we can try to get the Pac back to something that is workable. You can see a big cyclone spawn near Japan as the high descends over China and then the cyclone keeps that gyre over AK going. I don't know much about the E. Asia rule stuff, but that would also seem to suggest the possibility for an east coast storm in a couple of weeks? You can actually kind of see that at the end of the gif. 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted December 28, 2020 Share Posted December 28, 2020 As an addendum to the post above, the strat. weenies on twitter seem worried about overnight and yesterday's trends, just as we would be worried about a NW trend. there seems to be some concern over the strength of wind reversals. Don't ask me why that matters. Don't know and don't care, until I can figure out precisely how it translates down to the pressure levels we care about. But, on that note, apparently there is a paper coming out examining the lag between a SSWE and it's evidence lower in the atmosphere: 2 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted December 28, 2020 Share Posted December 28, 2020 Fully caffeinated now, I think if anything the models are seeing a potential end to the Pac jet extension now. I think it's just too soon for them to see anything meaningful from the strat. Here's a gratuitous EPS gif, so it's not all GFS stuff: 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 Sneaky system on the Euro operational at 156. The GFS has had this off and on. 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 The 6z GFS and 0z CMC also have it to varying degrees. Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 Big thing for the LR forecasts is to see that trough in the East moving forward in time mid mont. GEFS is definitely the better of the 3. It is worth mentioning that the GEFS did really well with the Feb '18 strat split. That said, if we steal a storm shortly after Jan1(before the warm-up), that would be big. Something to watch. Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 Just digging through the MJO this morning...lots of options on modeling. Most of those options deal with the right hand side of the MJO phase diagram. Generally speaking, there is a trend to go into phase 2 which is colder and then propagate around the to 4. The GEFS is very aggressive with this and only the hi-res goes into 2. They ECMWF goes 2/3 then COD. Phase 2 is colder. Phase 3 gets colder the further one gets into January. Phase 4 is warm. Seems like only the GEFS is wanting to gain amplitude with its MJO forecast, and its OLR map is curtly more aggressive than say the CA. Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 And modeling is having a rough time in the short term. Check out this westward jog(forecast Trent) for the system that was forecast to snow for E TN at one point. Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 1 hour ago, Holston_River_Rambler said: Fully caffeinated now, I think if anything the models are seeing a potential end to the Pac jet extension now. I think it's just too soon for them to see anything meaningful from the strat. Here's a gratuitous EPS gif, so it's not all GFS stuff: They are feeling the disruption now for sure. If the SSW can simply jostle the TPV and keep it perturbed, that would be the best scenario(as long as it doesn't tighten up). Seeing some disruption to yesterday's second week of Jan modeling. Guessing the Euro is slow with that trough. GFS Para also has the Jan 3/4 storm. Just read a post by Cosgrove that said each trough is going to press the eastern ridge further east(once it forms) - meaning trough comes through, ridge resets a bit further eastward, wash-rinse-repeat until it slides OTS. Trends on modeling during the next couple of days should be interesting(could be good, could be bad). The CFSv2 seasonal is back to a trough in the East for January. 3 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 28, 2020 Share Posted December 28, 2020 1 hour ago, Carvers Gap said: They are feeling the disruption now for sure. If the SSW can simply jostle the TPV and keep it perturbed, that would be the best scenario(as long as it doesn't tighten up). Seeing some disruption to yesterday's second week of Jan modeling. Guessing the Euro is slow with that trough. GFS Para also has the Jan 3/4 storm. Just read a post by Cosgrove that said each trough is going to press the eastern ridge further east(once it forms) - meaning trough comes through, ridge resets a bit further eastward, wash-rinse-repeat until it slides OTS. Trends on modeling during the next couple of days should be interesting(could be good, could be bad). The CFSv2 seasonal is back to a trough in the East for January. Evolutions looking about like we had envisioned. Hopefully, that will be the case. If so, depending on the speed, could be fun and games (plural ☺)thru much of January and possibly Feb...*hopefully I don't pull a Jeff and jinx us . Thanks to all the work Carvers, Holston, John et al do . You guys are the best ! 4 Link to comment Share on other sites More sharing options...
1234snow Posted December 28, 2020 Share Posted December 28, 2020 12z GFS is interesting at the 500mb level with the trough going negative tilt with the second wave at hour 144 (12z Sun, Jan. 3rd) at the Bama/Georgia border. This pops a strong coastal low that heads up the Carolinas and then out to sea. Mountains get a few inches as most the precip shield stays to the southeast which is fine for now. At least there is a signal at the 500mb level. I’m interested in the 12z Euro now that it showed this wave last night. 3 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 23 minutes ago, 1234snow said: 12z GFS is interesting at the 500mb level with the trough going negative tilt with the second wave at hour 144 (12z Sun, Jan. 3rd) at the Bama/Georgia border. This pops a strong coastal low that heads up the Carolinas and then out to sea. Mountains get a few inches as most the precip shield stays to the southeast which is fine for now. At least there is a signal at the 500mb level. I’m interested in the 12z Euro now that it showed this wave last night. Para-GFS on Pivotal is pretty much there. 2 Link to comment Share on other sites More sharing options...
tnweathernut Posted December 28, 2020 Share Posted December 28, 2020 Just glancing through the ensembles the last 24 hours. If the NAO cooperates to the degree shown on modeling, it would likely take a modest change in the Pacific to start throwing chances to track something wintry. I just hope the PAC finds these modest changes before the NAO shoots all its bullets. 4 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 28, 2020 Share Posted December 28, 2020 1 hour ago, tnweathernut said: Just glancing through the ensembles the last 24 hours. If the NAO cooperates to the degree shown on modeling, it would likely take a modest change in the Pacific to start throwing chances to track something wintry. I just hope the PAC finds these modest changes before the NAO shoots all its bullets. With Strong blocking, even with a crappy Pac, it can work out 4 us as long as enuff cold can be mustered up. Also , blocking should at least occasionally congest the Pac flow and buckle a Ridge in the West. Hopefully, timing with storms will work with that. But, yeah, at least a modest change would really up our odds. 3 Link to comment Share on other sites More sharing options...
tnweathernut Posted December 28, 2020 Share Posted December 28, 2020 9 minutes ago, Daniel Boone said: With Strong blocking, even with a crappy Pac, it can work out 4 us as long as enuff cold can be mustered up. Also , blocking should at least occasionally congest the Pac flow and buckle a Ridge in the West. Hopefully, timing with storms will work with that. But, yeah, at least a modest change would really up our odds. @John1122 would likely agree with me when I say I'd much rather have some PAC help showing. I have seen the PAC completely ruin our chances more than I can count over the last 20 years. How did you do with this last system. As an aside, how did you fare Christmas Eve? I was at my wife's grandmothers Christmas Eve in Tazewell and they ended with about 5". Hope you did as well! 2 Link to comment Share on other sites More sharing options...
John1122 Posted December 28, 2020 Share Posted December 28, 2020 28 minutes ago, tnweathernut said: @John1122 would likely agree with me when I say I'd much rather have some PAC help showing. I have seen the PAC completely ruin our chances more than I can count over the last 20 years. How did you do with this last system. As an aside, how did you fare Christmas Eve? I was at my wife's grandmothers Christmas Eve in Tazewell and they ended with about 5". Hope you did as well! Always favor the Pacific. We had a +PNA heading into the Christmas eve event. It's looking to hang out around neutral to mildly positive the next two weeks. It's not easy to make things work here and especially any further west of me, with a PNA that isn't at least neutral or some big time EPO help. 3 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 28, 2020 Share Posted December 28, 2020 28 minutes ago, tnweathernut said: @John1122 would likely agree with me when I say I'd much rather have some PAC help showing. I have seen the PAC completely ruin our chances more than I can count over the last 20 years. How did you do with this last system. As an aside, how did you fare Christmas Eve? I was at my wife's grandmothers Christmas Eve in Tazewell and they ended with about 5". Hope you did as well! Oh yeah, definitely agree! It's sure not the 60s and 70s anymore, when we scored regardless of a crap Pac. We wound up with 5.5 from last System. Claiborne, Bell and Lee all got more than forecasted. RGEM was on the money. 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 Looks like the d12+ GEFS, EPS, and GEPS now "splits" the western trough, and send part of it eastward. That is a good thing. The 12z EPS looks really good if one takes into account it is likely woefully undergoing the its trough(been a bias for months) underneath those blocks. The improvement since 12z yesterday is the eastern ridge appears temporary(at least for now - modeling is all over the place. I am a huge fan of the -NAO slows down flow and creates excellent confluence. Some great winters have had it. Some years with the Pac being the only dominant block, the flow is too fast. NW flow in Kingsport is also a non-starter as we don't get upslope stuff. A true -NAO (which is not battling the Pacific/MJO) is money during winter for east facing slopes. NE TN can get snow from an Atlantic fetch which is common during -NAO phase storms - TYS as well. The Christmas Eve Storm benefited from a PNA and the NAO both. Without the NAO, that storm likely cuts. Problem with the NAO right now...it is on its own and no cold source. If that NAO had Siberian cold to draw from...would be money - even if on its own. Our biggest problem regardless of the Pac or Atlantic blocking is that the cold is in Siberia. Saw Siberia nearly set an all-time record HP - think it was 1076 if the twee was correct. We need some of that here. I have my doubts that we get Canada seeded with cold anytime soon. Our cold will have to be homegrown. 1 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 For fun...Here are some historically great 500mb patterns for the TN Valley forum area during winter. 2 1 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 Some of those patterns are not too far from where we are now, especially 09-10. Difference is the cold source. 1 1 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 @Holston_River_Rambler, have those Euro Weeklies ready to roll? You get the honors. 4 Link to comment Share on other sites More sharing options...
John1122 Posted December 28, 2020 Share Posted December 28, 2020 Eric Webber says the strat split will likely couple with a west based -NAO and likely give us the best Atlantic based blocking since 2009-11 winters. He's pretty enthusiastic from Mid January on about it. Granted I think he's in Eastern NC and that may mean different weather for him vs us. But a powerful -NAO should help us all. 4 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 51 minutes ago, John1122 said: Eric Webber says the strat split will likely couple with a west based -NAO and likely give us the best Atlantic based blocking since 2009-11 winters. He's pretty enthusiastic from Mid January on about it. Granted I think he's in Eastern NC and that may mean different weather for him vs us. But a powerful -NAO should help us all. Webber is on fire today. LOL. 2 Link to comment Share on other sites More sharing options...
BullCityWx Posted December 28, 2020 Share Posted December 28, 2020 I think I read the weeklies featured a strong -NAO two weeks from now 2 Link to comment Share on other sites More sharing options...
Carvers Gap Posted December 28, 2020 Share Posted December 28, 2020 6 minutes ago, BullCityWx said: I think I read the weeklies featured a strong -NAO two weeks from now Oh yeah. It is a nice run. Hoping Holston posts a gif of the run. If not, I will post a screenshot of the 30 day 500 map - basically doesn't change so it would give everyone a good idea. He was bullish yesterday on the strat having a big impact. He got some serious backing today and really during the past 3 0z/12z suites. Looks like a really good call on his part. 1 Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 28, 2020 Share Posted December 28, 2020 2 hours ago, Carvers Gap said: Looks like the d12+ GEFS, EPS, and GEPS now "splits" the western trough, and send part of it eastward. That is a good thing. The 12z EPS looks really good if one takes into account it is likely woefully undergoing the its trough(been a bias for months) underneath those blocks. The improvement since 12z yesterday is the eastern ridge appears temporary(at least for now - modeling is all over the place. I am a huge fan of the -NAO slows down flow and creates excellent confluence. Some great winters have had it. Some years with the Pac being the only dominant block, the flow is too fast. NW flow in Kingsport is also a non-starter as we don't get upslope stuff. A true -NAO (which is not battling the Pacific/MJO) is money during winter for east facing slopes. NE TN can get snow from an Atlantic fetch which is common during -NAO phase storms - TYS as well. The Christmas Eve Storm benefited from a PNA and the NAO both. Without the NAO, that storm likely cuts. Problem with the NAO right now...it is on its own and no cold source. If that NAO had Siberian cold to draw from...would be money - even if on its own. Our biggest problem regardless of the Pac or Atlantic blocking is that the cold is in Siberia. Saw Siberia nearly set an all-time record HP - think it was 1076 if the twee was correct. We need some of that here. I have my doubts that we get Canada seeded with cold anytime soon. Our cold will have to be homegrown. Excellent Post !!! Link to comment Share on other sites More sharing options...
Daniel Boone Posted December 28, 2020 Share Posted December 28, 2020 1 hour ago, Carvers Gap said: For fun...Here are some historically great 500mb patterns for the TN Valley forum area during winter. Look at that "oddity" Jan. 96 one ! How often do u see that pattern occur ?! 1 Link to comment Share on other sites More sharing options...
Holston_River_Rambler Posted December 28, 2020 Share Posted December 28, 2020 2 hours ago, Carvers Gap said: have those Euro Weeklies ready to roll? 4 Link to comment Share on other sites More sharing options...
BullCityWx Posted December 29, 2020 Share Posted December 29, 2020 This was my favorite individual panel. 3 Link to comment Share on other sites More sharing options...
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