Holston_River_Rambler

I grew up just at the foot of Bays Mountain in Ridgefields neighborhood: 1983 - 2007. I remember in my ancient days (the early 90s) that some of the best of what I would now call orographic lift NW flow events seemed to come in from the SW down the side and up the Holston. Bays Mt runs SW -NE, so it's possible that the western edge just caught the band first and it seemed to be coming in from the SW. I remember many NW flow events where Carter's Valley seemed to always have the bands. 

I also remember one day my dad came back home after his morning trip to Pals and claimed the south/ east parts of he area (Ft. Henry drive/ Colonial Heights) had an 1" of snow and we had nothing. He sometimes liked to mess with me on the weather, but this is making me reconsider. 

I think I seem to remember one instance where some crazy upper low was over the Ohio Valley in a perfect position and cold air was getting pumped in from the SW, but may be wrong. 

On 11/26/2018 at 2:59 PM, Holston_River_Rambler said:

I don't think sliders or overrunning or clippers or -NAOs are going to get it done in the split flow

Starting to look like I may be eating crow on the sliders next week (gladly), although I do worry it will try to cut more and be more of a Miller B type coming in from that trajectory. No bueno for Knoxville, but maybe better for TRI/ Blunderstorm/ and Western areas. Still way off though. One thing I find interesting about this set up is the amount of energy. The FV3 keeps trying to have a more southerly secondary piece of energy develop (12-12) after the main wave (12-9/ 10). 18z GFS has it but makes more of a connection with piece one. 

Another thing I think is interesting is that the EURO/ CMC has this 12/4 - 5 system much more suppressed, but still has a similar solution for the 12-9/ 10 one. How would look on the GFS if the more southerly solutions on those two actually come to pass? 

Final thought in an image:

On the left is GFS forecast for 12/12/18 and on the right is 12/10/14. Not perfect matches and one still to be determined,  but the overall 500mb and surface pattern is close. Thought I'd put that on the table after the discussion of 14-15 as a similar year. 

Bays Mountain Lee Band is back this morning, if not as stout. 

Looking back over radar all yesterday and tonight, there was also one south of Knoxville aiming into N. Sevier and parts of Cocke county. This one is associated with the same geologic feature that gives us Kingsport's Bays Mountain, but the far SW extension of the same. 

It seem like they both  really like the flow to be just north of due west: https://imgur.com/a/OcFAiHN

13 minutes ago, 1234snow said:

Really interesting band has set up south of Kingsport today

I'm glad you mentioned this. I never would have thought to look at radar, but that is an odd band! It looks like it is coming straight off of Bays Mountain. I would normally see that as a downslope, but in this case it obviously isn't. Wonder what is causing it. 

Seems like there was something like this with a similar trajectory north of Knoxville last winter.

I made a gif of it case anyone wants to see later on: https://imgur.com/a/76Z8AHw

Found a nice website for N. Hemisphere info: https://yannickpeings.wixsite.com/nhatmosphere/copy-of-october-november-1 

If I have come off negative lately I apologize to all. I'm trying to dissect the pattern in any way I can to see how it might produce something and maybe I've just been too dissecty about it. 

Sorry if what I wrote came out wrong.  I apologize if it did. I ramble too much sometimes. That whole post was basically me saying, I think your original idea was right. The whole reason I brought in the NE stuff the way I did was that I was reading it too (probably to an unhealthy level) over the weekend and when their "pig" started to show, I started think, uh oh... I also thought the way they call it a pig was funny. 

To me their consensus now is that hopefully it doesn't linger and I wholeheartedly endorse that sentiment. 

I'm starting to think we may break even in December (0 on temp anomalies), so your warm up may be right. Hard to argue with some sort of-EPO showing up for at least a bit and as I mentioned, Isotherm seems to think its all part of interseasonal forcing. I think the more important thing is what the long range starts to look like once that gets established. 

Also, if I came off as saying you were arguing for a Strat PV split, I apologize. Ever since I saw the Ventrice tweet (somewhere in one of our recent threads) I've been watching the GFS strat on Tropical Tidbits and maaaaan did it look different today and wanted to share this AM. Still way out there but I can't say I wouldn't love a split and warming similar to what we had last Feb, but this time in Dec! 

The GFS is getting fiesty with the SPV in its long range: https://imgur.com/a/J7bgOS3.

See also:

I love that the NE folks have a name for the +EPO (giant upper low in Gulf of Alaska): the one eyed pig (took me a while to figure out what they were talking about, explaining it here for readers who may not know, so they don't have to, like me, spend a day trying to figure it out). I do not like that possible pattern, though it does make me want BBQ. 

I'm with you on this...I think. A lot of the discussion there (and elsewhere) has been:

Poster 1: "Oh God, it's the one eyed pig.!.!" 

Poster 2: "Weren't these the same weeklies showing wall-to-wall cold a week or two ago?"

Poster 3: "Probably need to take it seriously since it is a possibility, but with a grain of salt, since it is 12-15 days out"

Seems like a lot of handwringing over possibilities. I was 100% guilty of that over the holiday weekend.  Yes, the pattern is showing up on the EPS and GEFS and GEPS. Let's say worse case scenario, it verifies for 30 - 45 days. I'd rather have it now than later.  Other scenarios: it verifies in a slightly different way; it verifies after a nice storm in the east that tides people over; it verifies, but for a short period of time and somehow contributes to a better pattern evolution in the long run; it never fully materializes. Maybe I'm being too optimistic. 

When this pattern first started popping up over the holiday weekend, Isotherm offered an update to his Winter forecast that basically said: this was expected as part of the seasonal transition (hope I'm not misrepresenting that), keep calm and carry on. Crankywx on the twitterwebs has also been advertising a step down as part of the transition to winter that would feature a relax toward week one or two of December, although now he seems bent on trolling people on Twitter who hyped the -NAO/ Modoki as an intro to a new ice age.

I think that you're right Carvers in your assessment. We are in a cooler than normal and wetter than normal base state and that will have its say before its over. Jeff has also nailed the overall pattern over the past few months: cool and wet, relax and dry (hope I'm not misrepresenting either of y'alls thoughts). I think we relax after/around the 8-10th or so and this is what the weeklies are picking up on, and then (I hope) we step down  and start to see how things will develop after that.  I know, still wringing my hands a bit. It's been a long time since 2014/ 15 in Knoxville. 

I'm also interested in ENSO assessment for the pattern going forward. I've seen some different assessments today that show different interpretations of anomaly levels for the Nino regions and different assessments of the significance/ endurance of those anomalies (compare 40/70's take to Raindancewx's on page 22 on the El Nino 2018-19 on the Weather Forecasting and Discussion section of the larger forum). I've not usually paid much attention to ENSO other than the base state, but reading up on the current conditions and different people's perceptions of them, it makes me think that there is more variability in global pattern results than the usual "El = this" or "La = that" accounts for. 

 . 

After watching all these December patterns, I think the thing we need in the pattern we're in now for any chance at all is a big old ridge somewhere in the west to force energy beneath us toward the Gulf. I don't think sliders or overrunning or clippers or -NAOs are going to get it done in the split flow, fast Pac. pattern we're in. (Not saying anyone is saying that they will, just trying to point out how the pattern could work in our favor this time of year). Sure enough a big ridge is there at around 200 hours on the GEFS and GEPS. And the 0z EPS (and 12z Euro at 192), to quote Bob Ross, has an "almighty" one. Of course it still has to be there when we get to 200 hours in the future and we have to have energy to ride down that ridge and it has to be timed right, but without the steep ridge to aim it south and east, the energy will always cut to our west and north. I don't think suppression is a worry here since there is so much evidence things want to cut. They are cutting all over the place on the models, but they are still cutting. It all depends on the initial trajectory and where the cut happens. Get it to the Gulf, and then let it move NE. The further south we can get the energy, the better for us. Look at the N. Hemisphere 12z Euro at 500mb height anomalies at hour 192. If the Atlantic ridge was flexing a little bit more, that would sharpen the trough and help energy bottom out before it cut.  NW trend? What causes that usually? Stronger SE/ Atlantic ridging. 192 hours is only Dec 4 after all. 

Am I saying there is going to be something? Am I saying any of this will happen? Not at all. Just my two cents on what sorts of things we need with what we've got right now. 192 hours is a lot of time for ifs, maybes, and buts. 

Now watch me have to eat all this when the coastal plain or deep south gets a storm. It's there on 12z GEFS ensemble member 16. 

Looks like some nice snow squalls rolling over Frozen Head this AM. 

NAM, RGEM, ARW2 really want to develop a lot of snow showers in KY around the backside of the upper low tomorrow AM as it is moving through Ohio. Doesn't look like normal model wrap around moisture to me. Odd trajectory for upslope, but I guess from Paducah to Jackson is a gain in elevation.  Maybe southwest flow/ slight divergence aloft and instability with the cold air advection/ lapse rates aid in lift? Will be interested to see if this happens and is as widespread as the models suggest. Maybe extreme NE TN and SW VA can get in on a quick band or two if the trajectory is just right? This would be one of the few upslope trajectories for that area. 

I need to try to get back into basketball. Likely be less depressing this year. I used to watch it, but been more football as I've gotten older. At least the 2nd half of UT-Vandy isn't as bad as the first half was. 

Never mind, the 2nd half was just as bad.

18z GFS has lifted my mood. 2 snow chances and then this at the end, even if it is fantasy: https://imgur.com/a/m0XQlEJ 

The little system the GFS has been showing next Thursday or Friday might bear some watching. UK now has it and EPS went from maybe 1 member having it yesterday, to around 15 that look like the GFS or UK. Not much cold air, but we'll see how and if it plays out. At least there looks to be a big low in the Canadian maritimes locking in any high pressure there is. 

So... is the Modoki off the table @jaxjagman?  Basin-wide moderate, or are things still in flux?

Source of my question: 

Does Modoki vs. normal El Nino make that much difference for TN valley in the long run in terms of Winter pattern? Just heard so much about Modoki over the past years (not necessarily on here) and had my hopes up for something unusual this winter. 

@Daniel Boone here is December 1977: https://imgur.com/a/ukZ1bNJ  

Went ahead and threw in a storm from mid Jan. 78, since it was so close 

2 hours ago, Daniel Boone said:

77-78  was snowiest winter I've recorded here in Lee County. 72 inches. 4 inches fell Christmas day. However, it didn't start until early afternoon. There was already snowcover in shady areas since around the 10th. 

Looking at December 77 at 500mb it looks like a wild month. Looked cold at the beginning, then a short flip to mild, then a flip back to cold just before Christmas.  Around the 10th there was a 1049mb High dropping down from the Dakotas.  Looks like there could have been a nice clipper that swung through on Christmas. I am am only able to see the map at 500mb with MSLP, so there is probably a lot of the specific details at the surface I'm missing.

I agree with the MJO. If I remember correctly, models change their tune as we rotate through the MJO phases. Maybe because of base state programming to take into account this type of forcing?  7 - 1 (maybe 2 depending on the situation) are the cold/ favorable phases for Dec. for us.  We'll see if long range solutions start to change as we get into those phases. I also think there is a delay between a favorable state and its result for us. 

I think we're looking at cutters, but maybe even a chance for some sneaky follow up energy until the 10th onward. Then a trough is cut out and we'll see what we get.  Wouldn't be surprised to see what we saw last year at this time: front over some part of the south or our area, but this time with a different ENSO state. I REALLY like that gulf lows seem to want to develop this fall, maybe that changes the result. 

Looking like maybe some quick but squally upslope after this Monday-Tuesday system as a second vort. trails the main one.  It will depend on how much it digs. 

What the heck, might as well do some more weak El Nino Decembers:

Dec. 1968: cutters on top of more cutters, especially late month.  Nothing worth make a gif for. Maybe a slight chance that there was something Dec 7 -9 (weak low to our south that eventually cranked up to the NE; some nice blocking in the second half of the month, but not in the best arrangement for our area (example: https://imgur.com/a/8487tri)

Dec. 1976: looked cold overall. a couple of lows to our south and massive blocking (https://imgur.com/Xd1DJLt) at the end of the month initiated by a storm which took a favorable track for us: https://imgur.com/a/vEqRLBL 

Dec. 1978: cutter cold, cutter cold, until mid month when some big blocking began to develop: https://imgur.com/a/iyrZwDi  Sadly no lows to our south that I could see across the Gulf coast or in the Gulf, but it looked like the cold came late month and early Jan 1978. 

Decided to go back and look at some Decembers to remember: 1963, (since some have it as an analogue for this Dec.), Dec 1969 (since Jeff mentioned it may have had a white Christmas), and 2009,(since it worked out well for some).

I went to 

http://meteocentre.com/reanalyses/get_reanalyses.php?lang=en&area=hnord&yyyy=1997&mm=11&dd=20&run=12&mod=ncep 

and made some gifs of the 500 mb patterns and MSLPs:

Edited to include 1953, after reading some raindancewx's and our ENSO discussion. Seems to be some worry about the loss of a Modoki today and Raindancewx liked 1953 as an analogue for this year's Dec. 1953 pattern looks somewhat familiar to what the models are now showing for the first week of Dec. Cutter, cutter....then another cutter. Then we get this for the 13 - 15th December 1953: https://imgur.com/jSwv05K 

1963: https://imgur.com/0rrQW6a  (the whole month since many have used it as an analogue; mostly 6z and 18z snapshots after Dec. 10, but I used 0z and 12z near anything that looked like a storm for the area. Storms around Christmas and New Year)

1969: https://i.imgur.com/c8npZub.gifv (Dec. 20-22)

2009: https://i.imgur.com/MD99suk.gifv (Dec. 17 -19)

All very different looks at 500mb.  All got the job done for at least parts of the forum.  I understand that analogues don't mean the same thing will happen again, but thought it couldn't hurt to look.  Mostly inspired by the desire to see how the overall patterns looked and to see if I could see any specific beneficial set up for December storms.  Willing to do more if anyone has dates they want to look at. I did this with the static maps last spring, but these gifs allow us to see the overall flow/ progression over time. 

I like the progression of the 12z EPS at 500 mb from hour 192 on. Eastern Canada blocking sliding south, upper low looking to try wobble west and south into Hudson's Bay, not only helping to position and hold the E. Canada blocking, but also helping to increase a Western Canada ridge: https://imgur.com/a/Z0lYJSz 

I almost feel like if I had another panel on Tropical Tidbits, the lowest heights and trough axis would move and consolidate to E. TX.   240 hours+ so I guess we'll see. I like that this is an evolution of a pattern (the model has started to see the new pattern and ingested it), vs a new pattern showing its hand for the first time. 

Established pattern + progression > first look from a distance when dealing with models?

TBH not sure it is established yet, but we're getting close. 

Happy Thanksgiving from the Holston!!

Also, let's see how this ages (not endorsing, just throwing it out there and let's see what happens): 

Taking Carver's post in to account (posted while I was typing the below) the first part of this post is regarding the nearer term (pre day 10):

So, does the -NAO now work for us like putting your thumb over a water hose with the furious Pac jet others have been pointing out?  All that energy just gets funneled through, under the big block in eastern Canada and into the Atlantic without a cooperative Pac. block to funnel or split it in a favorable direction?

On the other had fast flows can be wild/ changeable flows? Last year around early December I think (if I remember correctly) we saw in a very different ENSO state how poorly models did and how quickly things could change.  

Now post day 10:  Masiello argues, if I read him correctly, that the cyclonic wave break brought on by the Pac could initiate a new (maybe refreshed is better) -NAO, (using Nov.-Dec. 1963 and 1977 as analogue years) and colder temps. 

That's the tweet.  Yeah, his feed has been technical this fall. Lots of Hadley cells and Ferrel cells... over my head too. 

For my post above I just watched that high not move and started to think, "man, if that were to produce a cold air mass end up dumping across N. America..."  so that's where the question came from. I went back and looked at the 850mb and surface temp anomalies/ temps and it looks like most of the deepest cold is funneling into Siberia at this time and in the near future, but who knows going forward. I do think that set up seems rather unstable long term in that all those lobes would want to reconsolidate, but I'm in over my head at that point.

The Greenland block does look like it sort of shoves the "doughnut" more over the pole and seems to lock those low heights over there. So even though it slows the flow down, maybe it hurts us that way???