weatherwiz

Basing a seasonal forecast on just the strength of an ENSO event alone is so 1990's and basing just off structure is so 2000's. There are a million things to analyze, assess, and consider. It's important to understand the role each phenomena plays on the atmospheric circulation. Here is the typical 500mb pattern for all EL Nino's. Clearly, you can see when averaging all EL Nino's, there is a tendency for a deeper Aleutian Low with ridging within the Arctic domain into Canada, with a trough signal across the southeastern United States. Now from many of the composites posted in the "Let's talk ENSO' thread, it's evidentially clear there is a wide range in pattern circulations during EL Nino episodes. What then becomes important is understanding how things like QBO, PNA, PDO, EPO, tropical forcing, all contribute to shape and disrupt the "mean". While EL Nino's tend to yield +PNA (as shown above), it's important to understand there could be forcing's which mute this PNA signal. I should retract a bit because strength/structure do play a role...I didn't mean to dispute that but disputing the notion of being pessimistic just because strength.

The numerous composites I've posted which break down each event individually state otherwise. There are weak events which were cold, warm, decent snow, little snow. There were moderate events which were cold, warm, decent snow, little snow. There were strong events which were warm, cold, snow, and little snow. Majority of EL Nino's tend to be east-based since they develop east and build west. -PDO/EL Nino winter's include 1911-1912 (cold east) (moderate EL nino) 1919-1920 (warm east) (weak EL nino) 1951-1952 (near-avg) (moderate EL Nino) 1953-1954 (slightly above-average NE) (weak EL Nino) 1965-1966 (cold east) (super-strong EL Nino) 1968-1969 (cold east) (moderate EL Nino) 1972-1973 (warm east) (super-strong EL Nino) 1994-1995 (slightly above-avg) (moderate EL Nino) Siberian snow cover is the most overrated thing ever.

100% agreed with those points.

Like Ray I feel good about this winter's prospects. Anyone discounting winter just because of ENSO strength is doing themselves an injustice. I think some just automatically mean a warm winter when they hear strong EL Nino because some of the more recent episodes. But I think this EL Nino will rival some of the earlier EL Nino's.

Also kind of reminds me of 1965-1966. Not sure what that produced in terms of snow but it was a drier-than-average winter across the eastern third of the country. That was also a strong/super strong EL Nino w/-PDO

How so? Here are temperature anomalies for strong and super strong events. Three things are noted 1. Strong/super strong events can still produce below-average temperatures within the United States and especially across the East 2. More recent stronger episodes have been on the warmer side 3. super-strong certainly tends to favor warmer, but the 1965-1966 winter was far from warmer. The sample size with super EL Nino's is also super small so not much to work off.

Yeah the "bad luck" of 2009-2010 I don't think had anything to do with ENSO strength. In fact, that winter was more a borderline moderate/strong event. Technically it's strong because of the threshold values (both within the ONI and ENS-ONI) but it was right on the line. The anomalies within the Arctic domain were intense over a very large spatial area and also pretty far south. If anything, stratospheric processes and stratosphere-troposphere coupling had a much larger role than ENSO. In fact, if you just look at ENSO, the atmospheric circulation was fairly similar to what you would expect for an EL Nino (particularly moderate) it was just distorted a bit due to the Arctic domain.

Yes, that is a huge issue of mine. I've been trying harder to set a scope and stick to it. I often find myself trying to get too cute when classification of things, needing to understand not everything is textbook.

@40/70 Benchmark I was reading your post and looking at the 2006-2007 winter and noticed you classified it as WQBO while in my notes I put as a descending easterly so I went to look at the QBO data. I am guessing QBO phase in the 30mb - 50mb level is what is most important? This is why I wrote down descending easterly but clearly 30-50mb level was positive during that time with easterly above it.

I'm just glad I didn't type up the QBO portion of my outlook yet...I'd be fuming right now with all that wasted work. I'd probably be going home tonight and cuddling a 40

too many notes going on and too much stuff going on

I'm reading through your solar/QBO section now and I'm surprised nobody called me out on my post yesterday. I incorrectly stated that descending easterly QBO phase does not favor blocking, when blocking potential increases during the descending easterly phase. I saw your post and went back to my QBO notes to confirm. In a notebook I had some notes on QBO/Arctic domain and had strong in parentheses...but I was thinking I meant strong blocking when I meant strong PV...so I had it backwards in my post yesterday

This is incredibly well-done! First off, I have never even come across the EMI. So this is some great learning material for me. Secondly, I am super happy to see what you mentioned about challenging signals regarding tropical forcing during basin wide events b/c that is exactly what I had noticed too (after that screw up I had late in the summer in the thread I made). But I tried to break down tropical forcing into east of dateline, centered around dateline, and west of dateline and it was very difficult to obtain clear-definitive signals. I am going to thoroughly read through the sections on solar over the course of the day.

Yeah this is something I definitely won't be incorporating into my outlook because I have zero knowledge on these and how they can influence the stratosphere-troposphere. I'll have a little section dedicated to "other factors that I am clueless on, but are important" to touch on this.

Yes, I agree with that. I remember too trying to focus a quite a bit on that characterization...in fact, that was my plan when I started really getting back into seasonal forecasting late last fall and I started with all my composites. But in doing so, I've found that the characterization alone isn't as important as some say it is...but you're absolutely right, it still needs to be incorporated. I at least found this to be true with EL Nino...not sure about La Nina but I'm going to begin La Nina composite stuff after finishing my outlook and work on it until winter gets crazy.

This is a route I'm trying to go as well. This is my first attempt at a seasonal outlook in quite sometime...probably since like 2014 and I like where I've come along since. I think I just used to look at the ONI, look for years in which values were similar, and those years were my analogs

Correct, this I understand. This is why I've created all those GIFs and have my massive binder of print outs I always look at anomalies first and then a hard index value second.

I'm hoping to be able to spend some time looking back at zonal/meridional wind means and anomalies from previous Nino's. I have some composites made for those but I only did a breakdown based on tropical forcing. But now that I have seemed to shake off my confusion, having a +PNA would certainly help with keeping the northern stream around and potentially involved, correct?

We'll really have to see how coupled the atmosphere/ocean become. I have to believe we may see some significant changes within the PAC (outside of the ENSO region) because the current configuration with the growing and strengthening Nino is rather bizarre. Part of me really thinks that even if we do see a stronger EL Nino (but not quite super status) this EL Nino may act like EL Nino's of yore which could bode very well for us.

Yeah I had it reversed... A strongly +PNA is pretty solid...it's when the +PNA is of a weaker signal issues can arise. But I'll be digging more into the PNA side of things this upcoming week and aiming to have my outlook complete this weekend. https://www.worldclimateservice.com/2021/09/08/pacific-north-america/

It would depend. If we're in a suppressed pattern, if the jet is active, it probably wouldn't benefit us much. The look above looks like a fairly strong +PNA. I know +PNA comes across as good for us, but I think if the +PNA is moderate-to-strong that results in a suppressed jet stream. What I find highly intriguing though is some of the looks presented on these seasonal models are much more consistent with how the atmosphere responded to EL Nino's prior to the 1970's. Many of the EL Nino's since then have been much warmer. I am hoping to really finalize my thoughts on the upcoming winter by this weekend, but I am not so quick to jump on the warmer just because we may see a strong EL Nino. This EL Nino may be one of the more unique we've seen, especially given the state of the PDO (which is negative). unless the PDO signal weakens it's fairly negative and there are not many (stronger) EL Nino's with this PDO state. There also aren't many EL Nino's with a robust PNA signal like displayed above. One thing that does seem to be a fixture of EL Nino's is perhaps not necessarily blocking, but above-average heights within the Arctic domain through Greenland. If we did see the troughing across the southern US like what is advertised this would help with a stronger STJ and as long as the pattern isn't suppressed we could really cash in. I am a bit skeptical of how helpful the Arctic will be though. While it's always good to see above-average heights within the Arctic - Greenland domain, that doesn't always equate to blocking or mean there is blocking. The QBO phase and trend is one that reduces the potential for blocking as well. Anyways, at least in my mind, this is going to be one of the more unique EL Nino winters we've seen. Even when I finalize my thoughts I am not sure how confident I will feel because I can ultimately see this winter going in any direction.

That December pattern is a pretty classic EL Nino look, especially with some of the more recent EL Nino's. That is a great evolution into January though, but my concern would be suppression and perhaps moreso, a rather inactive storm track.

I know the depth of the warm waters don't seem particularly deep, at least enough to make me feel like we are headed towards EL Nino. We'll have to see if we can maybe get some strong WWB's as well. After a rapid transition into EL Nino, however, the degree of warming has certainly leveled off and maybe even slightly decreased.

Something else I wanted to add to this. It's also extremely interesting the gap between weak EL Nino events. After the 1979-1980 weak EL Nino (which isn't even defined via the ENS-ONI) there was not a weak EL Nino until 2004-2005 (which also was not defined via the ENS-ONI).

I'm not even sure if a quick turn around would have much of an influence.