EasternLI

Yes. Ensembles have come to a better agreement on that overnight. I've been monitoring over the course of the last week. The GEFS has been showing this repeatedly. The eps has been off and on with it. Eps mean was a good move to the GEFS last night though. I'm talking about the VP 200 charts not the RMM diagrams. Still need to be mindful of things that could interfere, such as tropical cyclones. My original thoughts on this looking good. Perhaps delayed a couple of days I suspect due to shenanigans with that Typhoon in conjunction with the wave break.

Well, it's already happened during October for starters. Arguably during a time when the la nina was less favorable. Also, during a climo time of year when the MJO is usually dormant. Interesting. Remember, if you will, the October nor'easter.

I would be really interested in seeing some model scores for east coast cyclogenesis. I don't recall ever seeing a product like that. Or even a study, though maybe one exists somewhere. Would be fantastic if a product like that existed.

Right, but it's unusual. It was central based looking for a time. Now we have this. Pretty sure that's not a typical evolution for east based events. So it's definitely interesting for me.

Originally in the fall, it was Basin wide. Since then, it's taken an east lean. Which is pretty interesting. I feel like that's an unusual evolution.

I've been guessing that Typhoon in the far west pacific is playing some roll with that.

This is some big time amplification way over in the western Pacific. It's in a location that promotes the -PNA pattern advertised. That's also a +nao signal too. The pattern shown on ensembles has tons of support. Still thinking the Typhoon gave a little boost here. Don't be surprised if some of that record heat is somewhere in the east at some point soon.

I got to experience something like that. Flying to and from Vegas a little over a decade ago now. Record jet at that time. Took us 8 hrs to get there. Coming back to JFK 4 hrs. Was mind blowing to me back then lol

For example, here's the wave break with some additional juice from the Typhoon into the jet.

I get the impression that they're all related. Cumulatively amplifying the signal in that area. So we're seeing the amplified aleutian Ridge -PNA pattern like we are. Makes sense I think for the period. Could be aiding the +AO spike too for that time.

Thinking that this west pacific Typhoon is messing with that west pacific mjo. For now anyway.

The biggest question for all of winter is whether this la nina behaves more East based or more central Pacific based. Negative PDO plus East based la nina is a -NAO signal. +NAO for central based. This relationship is for JFM. https://journals.ametsoc.org/view/journals/clim/30/9/jcli-d-16-0376.1.xml?tab_body=fulltext-display#fig3

No changes in my thinking. Still on track. Looking for pattern improvement post mid month. That MJO wave is losing coherence while traversing the la Niña. As it reaches SA it's amplifying. That's what the ensembles have been doing and continue to via chi 200 charts. There are some warm waters in the Atlantic which could aid this? This should hopefully set in motion a series of favorable wave breaks. That's the idea. But it doesn't happen immediately either. So target is 2nd half of December to potentially benefit. I can see a couple of curve balls which would need monitoring. The stratosphere. As extremely unlikely as it is this time of year, any ssw reshuffles the deck totally. Would need reevaluating. Tropical cyclones are another. They have enough energy to disrupt everything. There are definitely much worse ways to be heading into this month in my view. Some interesting possibilities at the very least.

I can totally see that as being a contributing factor to such events. Absolutely. However, the MJO staying in phases 4-6 for the autumn is not surprising for me. As that's a climo location for la nina events in the autumn. The MJO is supposedly dormant during autumn so the la nina base state is that area. Which is what we're seeing there IMHO.

Some snow flurries outside. That's the first flakes of the season that I've personally seen.

Interesting little recurving Invest in the west pacific. Could help explain the MJO Phase 6 interference. Or maybe it doesn't recurve, who knows. Interesting nonetheless.

I agree with that. I'm not bullish on early December. It'll be really interesting to see how it goes later on.

I actually view this as a good thing. Lines up better with the good la nina analogs then the bad ones. Bad ones would be like 2011. That was further west into the IO in autumn 2011. Which seems to be a key reason for that winter playing out how it did, according to some reading. Other years look much more similar to what we have this year. I won't post those for risk of being severely weenie'd lol.

Just to be clear. The stuff I'm referencing would be longer term. 2nd half of December. However, could be potential for a fun holiday season if things work out nicely

Here's another interesting more recent article. This is focused more solely on the qbo modulation of the MJO - NAO response. Interestingly to me, the reanalysis composites had a more favorable orientation of the -NAO response during EQBO than during WQBO years. https://www.tandfonline.com/doi/full/10.1080/07055900.2021.1944045 The results can be summarized as follows: MJO Phase 3 in WQBO winters The observations show a statistically significant positive NAO as do seven of the ten models. MJO Phase 3 in EQBO winters The observations show a positive NAO signal, which is not quite large enough to be statistically significant at the 5% level. Only one model shows a statistically significant positive NAO signal. MJO Phase 7 in WQBO winters The observations show a negative NAO that is significant at the 5% level. Only one model produces a significant negative NAO. MJO Phase 7 in EQBO winters The observations show a negative NAO signal that is not quite large enough to be significant at the 5% level. Four of the ten models produce a negative NAO signal that is significant at the 5% level. It should be noted that the observational signal, while not quite significant, is larger than that of the models with a significant signal, which may be related to sample size and variance.

East QBO plus La Niña favors eastward propagation of MJO events. https://www.tandfonline.com/doi/full/10.1080/16742834.2019.1588064 During a La Niña year (Figure 3(c,d)), the effect of the QBO dominates. For each La Niña/QBOE year (Figure 3(c)), there are 1.7 MJO events, which is much larger than that in an El Niño year and La Niña/QBOW year. The last phase has only 0.6 MJO events (Figure 3(d)). During a La Niña/QBOE year, the MJO can propagate to the western Pacific without being suppressed over the Maritime Continent. During a La Niña/QBOW year, the existing MJO is observed to be enhanced over the Indian Ocean, while it is barely able to pass the Maritime Continent (Figure 3(d)).

Yes, what dmillz said. Looks phase 7 ish to me. That has legit potential to ignite a -NAO too. Perhaps phase 8 after?

If accurate, December is going to get pretty interesting IMO with a look like this. Really liking some things I'm seeing as of late. Haven't been able to say that in a while.

Just a nerdy little observation here. The QBO is every bit a temperature oscillation as much as a wind one. Research has shown that this is an important factor in the tropics. Specifically for tropical convection. The tropopause layer ~100mb in the tropics sees warmer temperatures in WQBO and cooler temperatures during EQBO. Generally. So cooler temperatures there can increase instability via increasing lapse rates due to warm ocean temperatures. Increasing convection. This is pretty cool. Check out the temperatures at 100mb this month. Focus on the area around Australia. Anomalous convection lines up really well with the cooler temperatures during the same time period. It'll be interesting to see how things evolve.

From what I've read, the Indian Ocean and the western Pacific Warm Pool are two areas under increased scrutiny in recent years, and continues to be. Mostly because of projected warming in that part of the world. Most of the research done previously did not look into possible global ramifications only local ones. The following recent paper, for example, attributes the +NAO of winter 19-20 to the very strong IOD of that fall. https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/asl.1005