EasternLI

Just happened to come across a BOM update from a couple of days ago on the IOD. They expect lingering influence into January. It will be interesting to see what happens with that. http://www.bom.gov.au/climate/tropical-note/ "The decay of the IOD is associated with the seasonal development of a monsoon trough in the southern hemisphere around December, but this process is well behind its typical schedule and is likely to happen significantly later than usual in 2019. As a result, the influence of the IOD is expected to persist into January 2020."

-NAO signal is still there. This is what that looks like on an ensemble mean. The EPS took steps towards this look today. First 00z then again at 12z. Here's the GEFS. Now, that outcome actually has some support. From the MJO. Some research has shown that MJO passage through phase 7 can force -NAO between 10 - 20 days later, if the atmosphere is receptive. +NAO after passage through phase 3. Right on time as per latest guidance. Note, I'm not looking for any specific storm threats right now. I'm more interested in the big picture. I'm a pretty big fan of what's been happening thus far.

Warming trend cancel?

Ensembles (GEFS + EPS) are warming up to the -NAO idea. Looks like there's potential for a split flow out west and quite possibly a legit -NAO along with it as we get towards the end of the month. Good times. I can't help but see these developments as positives as we move forward.

Well, alrighty then...

Agreed. Will be fascinating to watch everything play out.

Right, and that's why I find the end of the ensembles very interesting right now. But I've also seen some research suggest that there is a 7-8 year oscillation between + and - NAO winter regimes. We're about due if that's accurate.

Thank you for sharing. My thought process has been similar. Especially the +IOD and the NAO. I don't put anything together like this mostly because of time restraints, but if I did it would be very similar. So good luck and I hope it verifies.

Yeah, the Aleutian low is where my eyes have been glued since the beginning of the month. It's really good to see since the favorable winter composites have that feature during November. It's not everything, no, but it's much better to have it then not. I think the +IOD could be beneficial this year. Because it acts to suppress tropical convection around Indonesia. Which is the warm phases of the MJO. That was a real problem area last year, as you know. Being so strong this year I wonder if the effects linger through at least a part of the winter. It's really a fascinating year, and I still like what I'm seeing.

That's the very beginning stages of a -NAO at the end of the ensembles. Both eps and gefs are showing it. Plus, the precursor pattern for it is being advertised before hand as well. Let's get that going in time for December for a change.

If we look at the 2 October's from your example and compare with this October from your post. One is a little more interesting.

LOL

Yeah, I saw that tweet. I've been trying to figure out what those other 2 years were. I'm assuming 94-95 and the 97-98 strong el nino year based on the following chart.

Looks like that would be MJO related. As the low frequency signal remains with the possible record breaking Indian Ocean dipole. I'm interested to see what happens after the fall with that. Being that the fall is climo peak for those events.

2005-06 and 2010-11 were both la nina years. 2010-11 is in the top 5 for la nina years in fact. I'll sell on either of those walking through the door. I'm still feeling bullish about winter attm, I'll take the over on 30" at NYC.

It's a good look to see setting up as we head to the end of the month and into November IMO.

Sorry I didn't get a chance to respond to you earlier. The idea is that you want to see the higher SST'S near the equatorial dateline. So that can drive convective forcing in that area. Which can help drive the PNA. That's the really simplified explanation. Now, other factors have to be taken into account, as well as how they all operate together. Some can constructively interfere(work with) or destructively interfere(work against). So either of those ENSO states can deliver a productive winter depending on the SST layout plus other factors. A neutral event is more susceptible to being overpowered by other factors but it's the same general idea. It gets complicated, because ultimately everything works together.

@bluewave

Since the NAO is being discussed in here, I thought I would share something I found with you folks. Just throwing this out there for discussion. UCL (University College of London) has a group that has made a prediction for the NAO for this upcoming winter season. Namely January and February. If it actually happens, who knows but I thought I would share it. "Our deterministic (single most likely) forecast for the 2020 JF NAO is a value of -0.86 or -0.85 in standardised units. This would rank the 2020 JF NAO as the most negative JF NAO since JF 2010 and the thirteenth most negative JF NAO since 1953." Their data and methods can be found in PDF form here: http://discovery.ucl.ac.uk/10080518/1/Saunders_Lea and Smallwood (2019).pdf

Yeah, and that's actually very interesting. It sounds a lot like an El Nino Modoki type 2, if that were to happen. There's a paper on that, in fact. Your post reminded me to look into that again. https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-12-00107.1 "For El Niño Modoki II (the third column of Fig. 4), the warm SST anomalies first appear in the subtropical northeastern Pacific in spring and then further develop, reaching the equatorial central Pacific. The SST anomaly pattern in El Niño Modoki II resembles the Pacific meridional mode shown by Chiang and Vimont (2004)"

Totally agree. As a result, I think that analogs are perhaps not as useful as they once were. I think I'm pretty bullish on this winter coming up. The + IOD along with the +PMM while enso is neutral has me intrigued. Add to that the descending E qbo with low solar background. It's an interesting season ahead of us I think. One thing I'm curious about is how a bloated Hadley cell factors into all of this. I'm not very fond of that, but it's the times we live in with a warming world I guess.

If at first you don't succeed... Give up?

Those two were also east based el nino years. Which we don't have this year. Plus, everything @bluewave mentioned. 1994 1997

Well, ENSO is neutral. So not really going to have any easy calls based on that index. That leaves the door open for other drivers to take the wheel, so to speak. I'm actually a much bigger fan of the SST layout than I was last year. Cooler waters near Indonesia as compared to last year for one, which I think was one factor that worked against last year. It'll be interesting to see what happens. What I find interesting right now is the ++PMM. Curious to see how that evoles going forward. I'm putting this in banter because it didn't seem right in the other thread amongst all the 90's lol.