40/70 Benchmark

Does it have the potential to be as poor as 2015? At this stage, absolutely. Are there still avenues to a better season? Sure.

This is new to me. 2-3 month lagged response?? One thing I will need to look at when doing my post season analysis next week is the connection of +WPO to the more active Pac jet, as last season was strongly -WPO. It may be that this analysis is difficult to do on a seasonal level, and it needs to be analyzed on a weekly basis. Additionally, I'm sure it's not a perfect correlation (increased PAC jet strength/+WPO), either.

Agreed, there were some competing forces. I have also mentioned that last season still had a notable dearth of true coastals, February blizzard not withstanding. However, we were still able to produce above average snowfall because it was consistently so anomalously cold. I think it was a combination of factors....I agree CC is playing a hand, but it's also important not to get carried away with over attribution. There are other reasons last season was not a 1995 redux....most notably, the solar cycle was somewhat more hostile and there wasn't as much high latitude blocking. There was indeed a far amount last season given the high solar/strong -QBO combo, but 1995 featured one of the more impressive seasonal blocking displays on record given the ascending solar phase shortly after min. That being said, I do agree 1995 was a decent analog in some respects...it was one of my main ENSO analogs. I did try to address all of this in my write-up. The Limitation of Traditional Conceptualizations In A Warming Climate The Relative Ocean Nino Index (RONI) attempts to remove the trend due to global warming in an effort to produce a measure that is of more direct relevance to changes in tropical convection driven by SST anomalies, rather than the general warming around the globe. This is similar to the issues addressed with respect to the original PDO patterns in that the general background warming alters these traditional relationships. Just as the west Pacific warm pool enhances the general cold phase of the Pacific despite the general warming along the coast of the western CONUS, it also strengthens the proclivity for the MJO to frequent the MC in a similar fashion to canonical La Nina despite any competing forces. In this case, the competing force is perhaps some heightened convection and vertical ascent in the vicinity of the dateline relative to what would normally be expected for a cool ENSO event. Thus it is probably unreasonable to expect as consistently of a cold pattern as seen in an older analog, such as 1995-1996, due to the increased baseline tendency for MC forcing and Pacific jet extensions. Note the absence of subsidence in the vicinity of the dateline in the traditional weak and east-based La Niña composites. However, the most recent weak and east-based events are not devoid of this Modoki like subsidence in this area, rather it is just more subdued. This is indicative of considerable periods of MC forcing and Pacific jet extensions, albeit less pronounced than in a canonical La Niña that is more west-based. This is also illustrated by the aforementioned increase in the Pacific jet over time. How this manifests in terms of the RONI is that these modern La Niña events often have stronger RONI values due to the west Pacific warm pool accentuating the cool ENSO influence. This is what feedbacks into the pattern that reenforces the cold over Siberia and warmth east of Japan that embodies the +WPO regime, and strengthens the jet. Below is the progression over the past quarter of a century in the north Pacific relative to the intensity of the Aleutian low, as the attendant Hadley Cell has continued to expand northward. Note that this western Pacific warmth was less pronounced in the older La Nina analog composite, which is why the jet was weaker in the mean. Given that the 2017 La Nina had an ASO RONI value of -.71 and ultimately peaked at -1.24(.53), and the ASO 2021 value was -.91 and descended to -1.23 (.32), the anticipated peak range from the current ASO value of -.78 is between -1 and -1.2. This range is essentially a compromise between the slightly lower range suggested by the aforementioned analogs, and current guidance, which is supportive of a slightly higher peak of -.9, which has been inching lower. The forecast range is on the periphery of weak and moderate designation, although it will likely be considered weak due to both the paltry ONI and 90 day SOI of 6.47, as well as a lack of the discernible Pacific pressure dipole that is characteristic of well established cool ENSO.

Fair enough, but all else being equal, I would still bet on +PDO developing during a stronger El Nino....especially given the past few events have been accompanied by -PDO.

Kind of analogous to ENSO in that the PDO cycle itself is still operating as it always has, however, the baseline warming is limiting it's ability to drive the weather pattern around the hemisphere. Interesting.

CANSIPS looks a bit more neutralish to me, since the warmth displaced northward slightly...probably in part why the model is colder in the east next winter.

I always joke about this, but that emboldened line is the kiss of death from you. I read that, and instantly knew that the next line would be something casting doubt on the notion of a +PDO accompanying the El Nino. Haha I can't imagine this being another 2023 in terms of the PDO. I think if it remains negative, it will be marginal. Just talking about the actual DM mean index reading....not trying to imply that the winter can't still be awful for the east.

Yes...first above average season since 2017-2018.

Yea, I am starting the post-season analysis next week. 71.75" in Methuen (see sig)

I wonder what CoastalWx thinks of this!!?

You know, we all focus on the hyper-bomb blizzards, but those always screw a large portion of folks over.....as we saw in February. In reality, the highest confidence route to the hallowed grounds of the upper bounds of the NESIS scale is to couple an immense arctic airmass and a slug of moisture on a SW flow aloft. Mutant SWFEs like the one we observed last January just cover hundreds of miles in 14-20" of snowfall, while as alluring as the 40" carrot that is dangled by a high-end coastal is, the tempest needs to track within a narrow corridor to score as highly as these more uniform distributors.

Well, it was a pretty memorable and spectacular VD Day melt 2007... triggered by the sudden epiphany that that particular snowfall, that night would never live up to expectations due to the inability of the mid levels to cool the .00000001C needed for the sleet to abate. #neverforgetchristine

Yea, good example is the 1991-1992 winter season being a -QBO, which is of course, not a good match to the coming season. However, since you are going +NAO, anyway, it really doesn't matter much.

Yea, it's going to be a bit before we can glean any insight with that.

Good example of this winter could look with a strongly +NAO/WPO. I am with you on the NAO, but main question is the WPO...I could see that being a bit more negative.

It's a more neutral north Pacific response, which means other hemispheric players are more influential. In 2023, the most prominent players were a raging +WPO/+NAO/-PDO. This is why I said that the NAO and the state of the extra tropical Pacific will be so crucial this year. I think that fact that 2023 resembled 1997 was largely due to the extreme +WPO both seasons. Dec 1997 actually had some blocking, hence the major SNE snow right before xmas. The PDO was also positive. 1982 was -WPO....my guess is we end up with a better extra tropical patten than 2023.

Think of the information that be gleaned from ENSO concerning the hemispheric response as a continuum of sorts...of both strength AND type. Climate change is exacerbating the perils of a reductive analysis that considers merely strength of ENSO because the fact of the matter is that the hemispheric response is becoming more nuanced and varied.

Simply knowing the strength isn't very helpful if you don't know what the response will be....quite the contrary, it can actually be misleading to a forecaster, which is the trap that I fell into in 2023.

Yea......look at the absolute value of each to obtain a general idea of how strong the event is, but more importantly, it's the relationship between the RONI and ONI that is indicative of the type of response that ENSO may induce around the hemisphere. The latter is what we really need to understand because knowing how strong said response will be is pretty useless if we have no idea what the response will be. I suspect we are going to need the RONI to be at least equivalent or greater than the ONI to avoid yet another muted Aleutian low/se trough couple response. If we have a very strong El Nino with a lagging ONI, as was the case in 2023, then you get a very strong RIDGING response over se Canada and an Aleutian low/se trough that is still meager.

This is why we are seeing less of an Aleutian low/se trough response.

1957 is best subsurface map in terms of placement AND intensity of subsurface warm pool. It's also a good polar analog in terms of solar and QBO.