EasternLI

There's been somewhat of a low frequency signal in the SA atlantic Africa sector. It's been there for some time now. It's identified on the VP 200 charts. That area reflects on the phase 7/8 RMM charts. As the MJO makes It's way towards that area, its constructively interfering with that signal. Amplifying. This has been shown on ensembles for a while now. Also important, the subsidence amplifying and pushing towards the MC. I feel like this adds a bit of confidence that we actually can turn this pattern around. It'll be fascinating to see what transpires with this.

I think ensembles are slowly coming around to the phase 7 la Niña look. I suspect the NAO look on ensembles right now is actually an atlantic ridge, similar to that composite, but spread is smearing that into the NAO domain. Any real -NAO wouldn't be until after the ball drops IMO. It's a slow moving mjo wave. I feel like any sooner progression would be too fast. Gefs is a little faster than eps. I'm thinking the eps has the better idea with the timing here. It's the very end of the 12z eps where the changes are just beginning. That makes some sense to me.

Yeah, always a concern. I've definitely had that in mind. HM actually touched on this with an interesting post yesterday.

Great post. An interesting thing about the background state this year. Its actually really favorable for mjo wave propagation, it would seem. Solar correlation is suggested in research to have a lag ~3 years. East QBO. La Niña. https://journals.ametsoc.org/view/journals/clim/33/1/jcli-d-18-0811.1.xml?tab_body=fulltext-display Specifically, under cool ENSO, easterly QBO, and SMIN conditions, evidence favors a strengthened wave train that propagates farther eastward and more strongly modulates SLP and SAT anomalies. The modulation is increased further when two or more of these conditions are simultaneously in effect. While internal intraseasonal variability is large and these influences may not be apparent during a given MJO cycle in a given winter, the length of currently available reanalysis datasets allows them to be detected via averaging and construction of mean MJO phase composites.

Some interesting factors on the field for the mjo this season, it would seem. From a recent paper on the MJO. I'm really interested in how things work out this season. https://journals.ametsoc.org/view/journals/clim/33/1/jcli-d-18-0811.1.xml?tab_body=fulltext-display Specifically, under cool ENSO, easterly QBO, and SMIN conditions, evidence favors a strengthened wave train that propagates farther eastward and more strongly modulates SLP and SAT anomalies. The modulation is increased further when two or more of these conditions are simultaneously in effect. While internal intraseasonal variability is large and these influences may not be apparent during a given MJO cycle in a given winter, the length of currently available reanalysis datasets allows them to be detected via averaging and construction of mean MJO phase composites.

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