Carvers Gap

No idea if correct, but the blocking up top looks short lived. Could easily be models decaying that pattern too quickly, and we have seen that many times before. OTH, the MJO is not gonna play nice, and we could be seeing a ridge back in the East to start December (duration TBD).

That is a score!

12z GFS has that now almost exactly. If real, that is a pretty significant upslope snow event.

That is my thinking. The Nina pattern around the dateline(cool SSTs) does not favor convection. Now, if the Nino manages to be slightly ahead of schedule or there is some warm upwelling, that could help us during the second half of winter. Either way, I think we see some help on the Atlantic side and maybe a very jostled strat most of the winter. I would not be surprised to see some sort of Alaska origin, cold air train. Basically a high in the Aleutians(not good), but AN heights over Greenland and HB. That would send the cold air down the Rockies. It would modify as it slides eastward under the Greenland/HB block but might be cold enough. Storm track would be a sneaky bonus.

Gonna be fighting a crappy Pacific most of the winter. SSTs favor a 4-6 MJO setup from what I have read. We will have to have a -NAO to counter it. Not optimal, but that is the way I believe. Looks promising at least for the first third of winter.

Man it is like someone just flip the lights off for summer. Record highs last Monday. Snow in the mountains over the weekend.

Even on the LR CFS2, the EPO and NAO never really form a couplet but they do this -> -EPO -> -NAO -> EPO over the next 6 weeks.

I saw where Cosgrove in his Sat wx update mentioned there are some similarities to NovDec 83, 93, 95, and 13. Sorry, I should have referenced your NAO discussion above when I posted earlier. Good find.

In the LR, it seems like as we lose the EPO, the NAO starts to build. Been a while since I have seen that type of good fortune.

The 12z GFS is just flat out cold. I didn’t think the Euro Weeklies yesterday looked warm either. (A bit rusty as I put my pattern discussion in the observation thread earlier...still, brrrr)

Pretty bad loss to a team that had a rough outing against Grambllng.

We were in Indianapolis foe the past four days for Marching Band Nationals. Cross country running season preceded that! Now, it is time for a break. When we arrived the temp was 75! Prelims were at Lucas Field and the temps outside for our walk down were hot! Two days later moderate snow was falling. We ended up with 2-3” of the white stuff. Nearly the same thing occurred last year.

Looks to me like only the tropospheric is displaced. Pretty solid consolidation up top.

The 12z GFS does not have a long term, strat split. BUT, the strat is on fire even as it reconsolidates. There is an equatorial displacement of cold air d10-15 on the GFS. Is it right? I don't know. Looks like two stout, cold air masses are depicted on it. At this point, that looks like our first winter-storm window. Yeah, I know it is November. That said, that pattern is ripe for a storm -> cold, GOM open for business. Likely will be more of a cutter, but if one of those 1040+ highs presses south it will displace the storm track southward in response.

Is there a 3-D animation of it?

We are gonna be fighting the MJO all winter the the IO and dateline SST setup. Probably going to be in the warm phases all winter as a generality.

@Math/Met, that was quite the mountain wave event last night!

So, shoulder season modeling coupled with the randomness of SPV potential....wx modeling is likely going to struggle mightily.

So, basically the split is shown on the 18z GFS around 10-12 days out. Usually takes a couple of weeks after that IF it is going to send cold southward in the troposphere. Timing on that would be the first or second week of December if North America benefits at all.

Yeah, not sure I want to see a SSW and subsequent SPV/TPV split that early. Now, if one wanted a wall-to-wall cold winter...those can start that way. I don't see that happening BTW. OTH, we could see our early cold December dump westward (climo says eastward in December), and we could see DJF go warm. Man, I am kicking myself for not seeing that. The massive warm-up along the East Coast is often a pre-cursor to big SPV splits. Mega kudos to Jax for point that out. Hope you are doing well, man.

Ha! Ha! Man, you have a to tell me when you know a split is coming. I had heard rumors and just looked at the 18z GFS due to your comments. Textbook split.

Yeah. SPVs tend to favor EurAsia. When we do get the split (and equatorial push of Arctic air) in NA, it favors the west. We have had some really good winters with the SPV and some really craptastic winters. The year with the Memphis sub-zero, multi-day snow storm...that was a good SPV split if I remember correctly. Seems like we do well with maybe 1/4 to 1/3 of splits. If we want winter to continue into Jan/Feb this year, we may need one. The positive QBO lends itself to less blocking. Nina should help early on, and hurt us later on....Right now, looks to me like we are setting up for a mid-Nov to late Dec cold shot, and then we could be done with the exception of thread-the-needle stuff. That early season cold pattern(potential...not certain) should not be related to the SPV, though admittedly I haven't looked at stratospheric stuff much at all in about 2 weeks. That thing could be on fire right now, and I wouldn't know. LOL. Then, Nina climatology should send the trough into the Mountain West during Jan/Feb - where it is now actually. So, if the SPV trough normally goes there anyway and Nina has it in the Mountain West anyway, I am for taking a 1 in 4 shot in splitting it and sending it eastward mid to late winter. Again, I think the rising QBO really argues against blocking after December. QBO should flip back to a more favorable cycle next August or so. But some winters don't behave. A third year La Nina is a total crapshoot in the meager analog packages available for that rare occurrence. You guys have had some great recent winters in middle TN. Knoxville has done OK as well. The closer one is to the Apps, the less these past Nina winters have been helpful re: snow. I think you all get one more potentially good winter before the ENSO pattern switches up to one which favors coastal tracks next winter as Nino takes hold.

If ever there was going to be an outlier(Grid references those), it is this year. Why? Climatology has been wonky for the past 4-5 years - almost doing the exact opposite of analogs at times. I believe this has to do with the temperature gradient in the Pacific being for uniform that stratified during ENSO events(reference one of the guys in New England for that...TyphoonTIp I believe). I do think the mean trough will be centered in the western Plains and Mountain West w/ intrusions into the East. This warm November is gonna flip hard to BN temps I believe. If it does that, I think the La Nina pattern is likely going to be a traditional sequence of BN/Seasonal December -> early cold shot January -> WARM February and and early end to winter. 2023-2024 I am about as bullish as one can be. -QBO, weak El Nino after 3 La Ninas, Pacific SST gradient reset after this cold episode(should accentuate the El Nino response here)....loaded for bear.

Legit snow set-up for next Thursday(16th to clarify) if the GFS at 12z today is to be believed. That window has shown up on multiple runs. Still, the GFS has shown those only to be in error - so huge grain of salt.

Euro during shoulder season is less than accurate for sure. It seems to lack the ability to see cold shots. However, the model is still usable when it does that. Just have to see only when he warmth backs-off, and usually that is when BN temps move through. Its seasonal is very warm for winter. Even though it is biased warm and it is shoulder season, its solution is plausible. We actually have not had a "stinker" of a winter in some time west of the Apps. Generally, we have had a storm or two that drops some white stuff(Chattanooga excluded). There are, however, winters in TN where it snows very, very little at all lower elevations. We are long overdue for one of those. That said, I think we see some extreme cold at some point west of the Apps. Base-warm winter pattern though looks to be likely - QBO, solar, IO, and Pac are bearish for sustained cold after December. But who knows? Recent climo patterns don't really follow the rules the mid-late 20th century. Winter has already set-in out West and is right on time. This also fits Nina climatology. IMHO, December is our best shot, maybe early January.