EasternLI

Seems like the weeklies have been struggling with the mjo. I remember the euro/eps weren't very good during tropical season. Wondering if this could be a related issue. Otoh, I realize it's terribly difficult to model the mjo correctly.

The basic explanation would be. The blue is anomalous trades associated with la nina (standing wave). You can see the warmer colors (MJO) Punch through the la nina standing wave. That's anomalous westerly wind. At least on this chart from the 12z eps anyway.

Like this?

Now, that stuff is only regarding the NAO though. Thinking the emerging - EPO will cool down the final third of the month more than we're seeing right now. Canada is cold. But we'll see. Ugly pattern beforehand though. Well advertised and supported.

Well yeah nothing ever means we'll get snow lol. But I do know that we won't get any snow with a death Ridge over our heads. At least there's room for some optimistic outcomes this year IMO.

They usually last ~2 weeks when there is no ssw as per research. I don't know if we want that anyway. Not sure about it. Like I said earlier in this thread, ssw has far reaching effects. Including effects to tropical convection.

Sometimes the stronger they are, the harder they fall.

This is what I was hinting at yesterday with possible ramifications to the NAO...

Agreed. The more amplitude we can get with the mjo moving forward, the better. Could have implications on the NAO too. But that would be further down the road. One thing at a time.

Looking at it a little bit more. Sort of looks like a blend of both composites to me actually. Could simply be reflecting the progression through that in between area during that time.

Interesting discussion. There are certainly some similarly to the Phase 6 composite too.

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.