George001

Yeah it has been an incredibly hot year overall. Summer was extremely hot and winter was near record warm as well, but I was referring to the past 90 days when claiming it wasn’t a torch. I know it has been a torch the last 2 winters, but I believe that things will be different this time based on some of the things I’ve seen this fall.

Yep that’s just very ugly. Hopefully it is completely wrong, verbatim I got a decent amount of snow in 16-17 but I do not want to take my chances with that pattern again. The extended stretches of warmth with small 1-2 week windows of opportunity isn’t going to cut it.

Over the past 90 days it has been slightly warmer than average but not a torch. The first half of November does look quite warm though.

I’m not sure, are phases 7-2 cold in the east in November?

The big difference was the temp profile, it was colder in the west late fall 2022.

I liked 2022-2023 as a possible analog at first but the fall pattern is completely different. It certainly could still have similarities though. Both are cold ENSO winters with a strong -PDO pattern, so I wouldn’t rule it out completely as an analog, it’s just further down the list now.

Yeah my post was kind of misleading, my bad on that. From what I have seen the guidance does have the warmth in the northern plains continuing into December, but yeah it should be much colder there in the winter. The main point I was making is that the fall pattern is completely different than the last 2 years, and when looking at winters with a similar temp/precip profile in the fall, there are some colder/snowier years in the mix. I mean a lot colder and snowier, like 13-14 and 10-11. I did not mean to imply that the northern plains would roast all winter with a strong +PNA, that would be a 14-15 type pattern. November was frigid in the east from what I remember and it was a warm ENSO pattern, so not a good analog at all. In 13-14 and 10-11, the plains was cold. In 13-14 in particular the plains was downright frigid, though the cold did bleed into the east as well. Of course, there were some really bad winters like 01-02 in there as well which is also a possibility.

What are your thoughts on the plains centered warmth? It has been warm and dry everywhere but the real torch has been plains centered. The seasonal guidance is warm in November but with a similar theme to the past 90 day temp profile. Based on the fall temp profile and weak ENSO, I’m actually inclined to think that the risk is colder/snowier rather than warmer than the seasonal guidance based on this, especially if we do get periods of -EPO. Getting enough -EPO to result in a BN temp winter with a -3 PDO is an extremely tough ask especially with CC so I wouldn’t outright forecast it, but it’s something in the back of my mind. I’m thinking +2 to +3 AN temps for my area, but I do think there is say a ~20% chance that cold bleeds into the east and just about everyone busts way too warm. I am nowhere near as confident as I was last fall in a torch winter.

I’m feeling pretty good about things where I’m at near Boston

The only exception to this would be when an extremely potent Nino is imminent. I know what the seasonal guidance is saying, but I’ll take my chances with the way things look now any day over how they looked last year in mid to late fall.

I remember that storm, it had DC to NYC getting buried and my area being on the northern fringe about 4 days out, and then the models shifted hundreds of miles north in the short range. I ended up with around 15, some areas in NNE that were expected to get 2-4 inches got 40 inches. That was a rollercoaster to track

Remember about a week ago our discussion on the SAI index? It has tailed off recently and is around average, so looks like the whole issue of how relevant rapid SAI index would be is going to be a non issue after all. What is interesting is I did some very basic research on years with similar characteristics to this fall (warm centered out west, bone dry in the east) and the results are quite interesting. The list of years is not as Nina dominant as I thought it would be. The MJO pulse going on right now though is very much reflective of a La Niña background state (As Bluewave pointed out, it actually matches the stronger Nina’s, not the weaker ones we have seen over the last 15 or so years). Perhaps the composite of years similar to the November pattern will be more Nina dominant. Won’t know for sure until mid-late November or so.

Yeah the lower terrain of the mid Atlantic needs a lot of help in December. Even my area December climo kinda sucks the first half of the month

I am trying something new this winter, I am going to use an analog composite, and rather than evaluate winter patterns based on average temp and total snowfall, I will evaluate patterns based on how long the period of favorability is (what many of us refer to as windows of opportunity). This methodology attempts to limit the role of variance. I don’t like the idea of classifying the 2016-2017 and 2021-2022 winters as successes, as I feel my area having AN snow those years is a product of getting lucky in a bad pattern, and I would expect a much worse outcome 9/10 times if you run those 2 winters in a simulation 10 times. I mean, in 2021-2022 I got buried with 20 inches of snow from one storm in a short window of opportunity in a sea of warmth. Thats why my area finished with AN snow while north, south, east and west finished with BN snow. The only place that did better than me was maybe the south shore where they got 30 inches. Hey, I’m not going to complain about getting lucky but I’m also not going to count on it repeating if we get a similar pattern again. More often than not, it won’t. Like any other approaches, this approach has its own set of problems. It’s not as simple as favorable and unfavorable. 2014-2015 had about 2.5 months of favorability and 1.5 months of unfavorability and so did 2017-2018. According to this way of evaluating winters, 2017-2018 and 2014-2015 would be equal. In reality, 2014-2015 was better and should have been. Why? Feb literally averaged -10 BN. The actual weather pattern was about as good as it possibly can be for New England. So the magnitude of favorability/unfavorability does matter, and this approach doesn’t capture that. I do feel this approach still has value even now, as I am inherently against the idea of using extreme analogs like 14-15, 11-12, etc to begin with. I do however think it will run into issues if we say get a high end strong nino/ moderate + strength modoki Nina with a -PDO like last year/the year before, or a weak modoki Nino/east based weak Nina with a strong +PDO like 14-15/95-96. Those scenarios have a heightened potential for an “extreme” scenario. Nothing really screams ratter or blockbuster this year, which is why I think this approach has some merit for this year and I’m going to give it a shot. I do plan to tweak it in the future to account for the magnitude of favorability/unfavorability, as that does matter and is a fairly big flaw in this approach. Though once you go beyond a certain +AN threshold you are looking at a shutout pattern

The CFS shifted back to cold for Jan (still warm in Dec and Feb). Lots of flip flopping… I’m taking anything these models say right now with a grain of salt, just too early.

That’s actually a really cool and creative idea. Credit to him for coming up with it, but I do see a flaw in the key principle from a data science perspective and potentially a business one as well. An amateur like myself will always have a major limitation, lack of background knowledge of meteorology. I suppose you can teach yourself meteorology, it seems like Raindance did that to some extent. But someone who has been doing it their whole lives and is in the field, they know what to look for, they still will know far more than we amateurs do. Domain knowledge is tremendously helpful in helping identify what variables would potentially have the highest correlation coefficient with important quantifiable things like temp, precip amount, precip type, etc. Really the best forecasts could be made if he hired and teamed up with a meteorologist to make this app. If I were him I would have hired a meteorologist to clue him in on what to look for, so he can further optimize his models and increase the predictive power. Then just make that your product and sell it, get a bag. Forget the fantasy football thing, if he combined his skills with a meteorologist, used that domain knowledge from them to optimize and boost the predictive power of models, that would make his predictions way better and easier to market. I mean, you could prove its validity instantly by backtesting on previous years. There is so much potential here. All it takes is not being so fucking arrogant that you think you possibly know more about a field you casually read up on. You think you are just gonna read a few peer reviewed papers and know more than experts in the field and have been doing it their entire lives? I don’t buy it. Not a chance in hell.

Yeah as someone who has been reading your blogs for years I’m going to disagree with that. You did reference his work, but you made sure to name him and give him credit. There really isn’t anything wrong with that.

Speaking of Raindance it’s a shame he’s gone. I was not a fan of his idea that you shouldn’t use the work of others (I am a big believer in the idea that incredible insights are developed by standing on the shoulders of giants, as Issac Newton once said). Although his bedside manner left a lot to be desired at times, he knew his shit and I learned a lot from him.

I appreciate the recognition, after all those failed blizzard calls I decided to read up more, educate myself and try to be as objective as possible. I still have my biases, but I find it a lot more rewarding putting in the work to learn from all the great posters on these long range threads such as yourself, Raindance, Bluewave, Snowman, GaWx, Don, Chuck etc rather than just wishcasting. It is a science board after all, the point is the pursuit of knowledge and truth. All that being said, the old weenie George is not dead. When the time is right (as in large scale cross guidance AND pattern support for a blizzard, NOT one or two rouge OP runs in the mid or long range), the weenie side of me will come to life again in the tracking thread. The days of me hyping up every fart in the atmosphere to be a Boston blizzard though? Those days are long gone. I’d rather appreciate the winter of 2014-2015 for what it was, a once in a lifetime event rather than setting myself up to be disappointed by having unrealistic expectations about my climo.

This is correct. It has been warm CONUS wide, but the core of the warmth has been centered over the plains. We aren’t seeing a trough out west with storms barreling into the Pacific Northwest like the last 2 falls (that pattern then continued into winter, leading to back to back ratters). For the NAO…. Im not sure it will be a good or bad thing yet. The signals are fairly strong for a +NAO winter, but that doesn’t tell us anything in itself. The -NAO patterns we had in recent years have been bad for the east because they have been south based events that linked up with the SE ridge. A raging north based raging +NAO where the cold is bottled up over the pole is obviously bad (this is what happened in 19-20, 01-02, etc), while a south based +NAO can actually be a good thing depending on where you live (14-15, 13-14, 07-08, 92-93 and 93-94 all had south based +NAOs).

In the later frames it gives my area an ice storm

Interesting, in the latest IRI update on ENSO the spread has decreased significantly and the mean has converged around a -0.5 ONI peak

That’s really interesting, I didn’t know rapid SAI could do that. That’s a great example of how simplifying things to rapid SAI = cold and snowy for the east, paltry SAI= warm and less snowy isn’t accurate. Things are a lot more complicated than that. We know right now the SAI is high, but whether or not that will be a good thing for the east remains to be seen.

Good question, my explanation is while there is something to the SAI theory, the correlation with the AO/NAO is much weaker than Cohen implies. From what I’ve seen though, during high SAI advance years we do see more PV disruptions (we saw the PV stretched south of a typical strong PV in 14-15 and 13-14), regardless of the overall strength of the PV and NAO phase. When it comes to the NAO/AO, the high solar/high geomag combo favors a strong PV/+NAO/+AO pattern. High geomag in particular has a strong correlation (>.7 r^2 value) to the NAO. I don’t know the exact r^2 value for the correlation between SAI and NAO, but I suspect it is much lower. So make no mistake, I’m still on board with a strong PV/+NAO/+AO winter, but I do think the vortex will be more susceptible to being displaced south than is typical for a strong PV/+NAO/+AO winter. This does not invalidate the 07-08 analog AT ALL. If anything, it strengthens it as this south based +NAO was seen during the 07-08 winter (my #1 analog).

I don’t see 15-16 as a good example of the SAI being complete BS, but I do see it as a good example of it being overrated in that it did what it was supposed to do, but other factors (mainly ENSO) were stronger drivers. It did what it was supposed to do, in Jan and Feb of that winter the PV was displaced south with periods of blocking. But again, the super Nino was the primary driver that winter. I do agree with you that the hype should not have been off the charts. I have no idea why Cohen forecasted an arctic cold winter during the 2015-2016 winter regardless of what the SAI did. 2015-2016 was the strongest El Niño winter on record, when ENSO gets that strong that trumps SAI every time. Even if last winter had a record high SAI, I still would have gone mild with below normal snowfall for my area due to the high end strong Nino, -PDO, and the parade of storms crashing into the Pacific Northwest during the fall.