EasternLI

This is what the GEFS and EPS is showing for VP200. The new EPS weaklies today continues this look right into December. Research says that Indian ocean convection will drive a strong polar vortex. Last year is a great example of that occurring. I didn't give that enough respect. So expecting a ++AO La Nina as of now unless something changes here and quickly.

The west pacific warm pool is of some interest this year IMO. It's something that I will certainly be paying attention to in looking at the sst trends in that area in the month ahead. This relates to the discussion of the PMM in the discussion thread. There's potentially some optimistic outcomes that could (or could not lol) stem from this as it relates to the winter ahead. Some recent research has shown that forcing in this area can actually drive an Aleutian low +PNA pattern during winter. Which in turn can act to cause a weak SPV. It should be interesting to monitor this area moving forward. Nonlinear response of Northern Hemisphere stratospheric polar vortex to the Indo–Pacific warm pool (IPWP) Niño https://www.nature.com/articles/s41598-019-49449-7 During boreal winter, anomalous SST warming associated with IPWP Niño can excite NH extratropical teleconnections that project onto the positive phase of the Pacific–North America (PNA) pattern in mid–high latitudes, intensifying the upward propagation of planetary waves into the stratosphere and, in turn, warming and weakening the NH stratospheric vortex41. Note that the wave pattern excited by IPWP Niño is located further west than the PNA pattern, a fact that may be related to the different wave source locations from that of ENSO.

@bluewave That's very interesting about the PMM October pattern. I didn't even think to look at that for some reason. I remember we discussed that in the past. I found that particular pattern interesting when it was first showing up on ensembles. So I dug into some Nina years to look into it a little. I had some difficulty finding anything. Which I guess suggests the rarity of it. I see 1995 was brought up a few pages back. That was actually the closest match I could find. Albeit, it didn't happen until the end of the month that year. Therefore the composite for the month as a whole looks different. Interestingly, it's almost a mirror image of the PMM pattern composite you posted.

Yeah, I've seen a couple papers that attributed it to the super Nino. A more recent paper goes into some greater detail. I can't help but wonder if the powerful +IOD event last year played some role in the odd behavior of this year. https://acp.copernicus.org/articles/20/6541/2020/ In addition to the anomalous behavior in the tropical lower stratosphere in 2015/2016, we explored the forcing of the unusually long-lasting westerly zonal wind phase in the middle stratosphere (at 20 hPa). Our results reveal that mainly enhanced Kelvin wave activity contributed to this feature. This was in close relation with the strong El Niño event in 2015/2016, which forced more Kelvin waves in the equatorial troposphere. The easterly or very weak westerly zonal winds present around 30–70 hPa allowed these Kelvin waves to propagate vertically and deposit their momentum around 20 hPa, maintaining the westerlies there.

Interestingly enough, the qbo that year actually was westerly below 30mb to the tropopause. This year actually looks to do that as well albeit with a thicker vertical profile. Also interesting in that 2007-08 was completely different then this year. Merely a couple observations. Cheers.

Worked this up for October 1970

Here's a newer paper on the MJO - AO connection. But also how the QBO modulation plays into it. For anyone who is interested in a little reading. It's open access. https://www.mdpi.com/2073-4433/11/2/175

These blasted 3 part ridges are always the kiss of death. Or are they?? I found that particular pattern to be interesting. So I did a little digging. Only instance of this that I've found in a nina thus far. Doesn't mean jack, just something interesting. At least I thought so. Seemed appropriate to post it here now.

In a MEI sense, 2007 looks like the best fit.

My girlfriend lives in Branford. She says trees blocking roads everywhere, and a tree came down in front of her on the way home from work. Took her 3 hrs for a 20 min trip. This was somewhere on Rt. 1

Merry Christmas

I guess congrats on relocating to a different area are in order.

This has really been an impressive +IOD event. I was looking through the fabulous JMA charts and the only one that looks similar was 1997. The super Nino. I know that they mostly coincide with El Nino, but not always. Interesting to see one so robust without an El Nino. I didn't see any other years that looked quite like this.

That's a good point, and a nice observation as usual. I strongly agree with the bolded. It's exceedingly difficult to have ridging in both locations simultaneously. That's been documented in the research as well. It makes sense too, when you think about it. Like when we see a trough on the west coast and ridge on the east coast. Maybe part of the story of the ++NAO during those years with the --EPO. Interesting.

This is my favorite thing that I've seen that I've been watching. Seems like the IOD has indeed muted the MJO in the Maritime Continent this month as was hypothesized by causing subsidence. It's been weakening. As it loses its influence more and more moving forward, what might be the dominant forcing then? I still like where we're heading. This is not last year.

Ensembles look pretty damn good as we move into the new year. GEFS and now the Eps today.

Cheer up. It seems like things are coming together nicely. Just not yet. Watch what happens when we start getting into January.

Christmas day high temps on the EURO.

Well verbatim, if the EPS is correct. It's the plains that sees the real torch and we are on the periphery. AN though, yes. Be interesting to see where it ends up. Going to need to put up some big numbers to close out the month if you want +2 or better imo.

Its also a reversal of the torch December's that we have been accustomed to for those years.

Interesting move from yesterday to today on the EPS. Yesterday, the TPV lobe in Canada was split with the dominant piece amplifying the AK vortex. Today, it's headed for SE Canada and 50/50 bound thereafter. Plus more arctic ridging yet again.

I've been intrigued by this winter for some time now. I still am.

AO heading in the right direction.

Big Iceland storm, looks wild.