George001

It’s difficult to remain optimistic during a stretch of winter like this. Things do look more promising on the models but I have been burned way too many times the past few years buying in when they look good. Hopefully this year and the next few years make up for all the garbage we had after the great 2017-2018 winter.

Yeah, my mistake. 13-14 had an extremely low ACE, it was below 50. 12-13 was the more active one with hurricane Sandy.

I like this tweet because it illustrates both the expected paths this winter can take (13-14, 01-02, 08-09 are all good to great analogs), and an unlikely but possible wrinkle. I do not think it will happen based on the latest guidance and current background state, but 92-93 came off a strong El Niño, was cold neutral in November and then ENSO warmed back up to warm neutral in winter. There isn’t enough to consider it a viable analog right now, but I’m keeping an eye on it as a “what could go wrong” thing.

Although I prefer 12-13 and 08-09 for the PDO specifically, in my opinion 13-14 is still a very strong analog. Great ENSO match (cold neutral), still a -PDO winter (like this will be), above average ACE, great polar match, etc.

12-13 (my #1 analog) had an earlier peak, but the -PDO peaked at -3 in September and was solidly in the moderate to strongly negative range throughout the winter. The timing is a bit off but I still would consider that to be the best match for PDO. 08-09 is decent too, but the PDO was more stable, hovered just above -2 and that continued into the winter. I agree with your general point though, although the -PDO has weakened a lot historically -2 PDO Novembers lead to moderate to strongly negative PDO winters. I considered using 92-93 and 93-94 as analogs because I like the solar match, but decided to eliminate them as potential analogs after looking at the PDO progression (both years were +PDO).

Low location is not ideal for that threat, looks like a cold rain.

Note: there is extremely high bust potential. The way I see it is both the middle ground and unfavorable path support AN to well AN temps (a 50% cold/ 50% warm split is tilted AN due to climate change). There is a 70% chance we go down one of those 2 camps according to my forecast. However, that means there is a 30% chance of below normal temps. Thats really not all that low, and is higher than I expected before I started the process of making my forecast. Climate change always plays a role no matter which path we go down. Climate change is a double edged sword. The average and unfavorable patterns will be worse. But if we can get a favorable pattern with below normal temps, the clash between that and the warm ocean temps could lead to enhanced cyclogenesis and bigger storms. If we go down the favorable path I would not be shocked to see Boston end up with around 70 inches of snow. However, if we go down the unfavorable path we are looking at +4 to +5 AN temps, in that scenario I would expect to underperform the expected 30-40 inches significantly. I wouldn’t be shocked to see 10-20 inches for the entire season if we go down that path. So this is a low confidence forecast and there is still a wide range of outcomes.

Although my last winter forecast was a success in that I forecasted AN temps and BN snow for the Boston area, I was right for the wrong reasons. So this year, the goal is to learn from that and continue improving. Background: Throughout the summer and fall, there was a lot of talk about the developing La Niña, the structure, strength etc and how it would drive the winter pattern. I was fully bought into that idea myself, but cracks began to show throughout the fall. Guidance kept weakening the La Niña over time, it was supposed to start in September, then October, and now it is November 21st and we are in ENSO neutral. In fact, on the weeklies ENSO 4 and 1.2 are straight up in warm neutral territory, while ENSO 1.2 has recently risen to weak El Niño territory on the dallies. The latest IRI update gives a 50/50 chance of La Niña development, with a peak of around -0.5 ONI for region 3.4 expected. Therefore, ENSO is expected to be very weak and thus not a major pattern driver (reflected by the latest MEI of -0.5). Based on the latest trends, my expectation is for the ENSO state to be cold neutral. Other factors will drive the winter pattern. Key factors: fall pattern- warm and dry expected ENSO: cold neutral High solar/geomag: favors a strong PV/+NAO/+AO pattern -PDO: Has risen significantly from -3 to -2 recently with some guidance indicating further rising, but the PDO should remain moderately to strongly negative throughout the winter. EPO: began the month positive leading to warm conditions, but shifting to negative to strongly negative in late November/early december Hurricane season: late developing but hyperactive- currently 160+ ACE, should be just about done based on climo. Expected ACE is around 165, maybe a bit less. Analogs: great- (2012-2013, 2013-2014, 2001-2002) good- (2021-2022, 2022-2023, 2016-2017, 2008-2009) So, we have a mix of great winters, ratters and mediocre winters in the analog package. There isn’t a particularly strong signal for a great or horrible winter, it’s somewhere in the middle with a lot of variance making the forecast difficult and low confidence. That makes sense considering we have a good mix of favorable (weak ENSO, late November -PDO, high ACE in cold ENSO) and unfavorable (-PDO, high solar/geomag in cold ENSO, warm and dry fall, warm November) factors. However, the way I will be evaluating winters is based on the length of the cold vs warm periods, not the total snow. You could luck into an above average snow winter despite an overall unfavorable base state, but that doesn’t mean we should expect that to happen again with a similar set up. On the other hand, we can get skunked with a more favorable base state and should expect better results if we see a similar set up again. Keeping this in mind, this is how I evaluate the above analog winters favorable (longer cold periods than warm): 13-14, 08-09 unfavorable (longer warm than cold): 01-02, 16-17, 21-22, 22-23 Middle ground (even split between warm and cold periods: 2012-2013 Analog weights: #1 analog (2012-2013): 5 points #2 analog (13-14): 4 points #3 analog: (01-02): 3 points All other analogs are worth 2 points. When the weights are applied we have: Total points: 20 Unfavorable: 9/20 points, 47% favorable: 6/20 points, 30% middle ground: 5 points, 25% Final forecast for Boston: temps: Dec-Mar +2 AN snowfall: 30-40 inches. Im leaning towards the lower end of this, so below average but not a total ratter.

I agree that the PDO isn’t going positive. The question is can we get an extended stretch of cold and possibly snow even with a -2 PDO? It has happened in the past, this year I’m not sure about yet. I don’t expect a 10-11 repeats where the cold and snowy pattern locks in for 2 months, if the cold pattern does set in I want to see how long it lasts before the shift back warm. Once that happens it isn’t over, then we need to see how long the warm period is before shifting back cold. Only when that happens will we have an idea of which camp this winter is headed. If the warm pattern lasts longer than the cold one, that’s an indicator we are headed towards the warm camp (01-02, 16-17, 21-22 top analogs). If the cold pattern lasts longer than the warm one that’s an indicator we are headed towards the cold camp (13-14, 08-09, 17-18 top analogs). I decided to remove 10-11 as a possible analog because it’s now both a terrible ENSO (strong Nina vs ENSO neutral) and solar match. I’m going to make my forecast by the end of the week, well before this winter shows its hand.

This has my attention because most of Allsnows posts the past 2 years have been favoring warmth to the extent he was accused of having a warm bias. He ended up being right, as the past 2 winters had near record warmth in the east.

I hope so, but I am skeptical of December as a whole especially given the recent warming trends in the ENSO region as well as the tendency for guidance to underestimate MJO amplitude. I’m not expecting any flakes before Christmas week for my area.

My issue is 2 of the 4 key ENSO regions are straight up in warm neutral territory. The RONI is rising too, it’s in Nina territory still but barely. I would not expect a moderate to strong Nina base state like 07-08, 10-11, 11-12, 22-23, 20-21 etc given the recent trends. Either way, I agree with you that guidance is too cold for the 1st week of December. The tendency has been for guidance to underestimate the MJO amplitude this fall, if that continues we should expect to see higher amplitude MJO in the warm phases and thus a correction warmer during the early to mid December period.

The whole Nina background state this, Nina that idea might need to be tossed out the window. All guidance busted way too cool with the ENSO projections, it’s mid November and ENSO 4 and 1.2 are in WARM neutral territory while ENSO 3.4 and 3 are right at +0.0. Guidance has ENSO 3.4 cooling again, but I’m skeptical of the more aggressive solutions given what we have seen this fall.

I was exactly that a couple years ago. I learned the hard way, all you do is set yourself up for disappointment when you wishcast and have unreasonable expectations.

You are entirely correct that people would believe the models if they showed warmth. Unfortunately the elephant in the room is the current background state, it favors warmth. Until that changes, it makes sense to be skeptical of colder solutions and favor the warmer guidance.

On second thought 10-11 isn’t really a good analog. That winter had an extremely strong Nina background state with low solar. The solar being the opposite isn’t enough to eliminate it as an analog, but now with the Nina fizzling out it really isn’t a good match. The whole Nina fizzling out thing has me skeptical of the whole strong Nina background state idea. On the weeklies, Nino 4 is +0.2C, Nino 3.4 is 0.0C, Nino 3 is 0.0C and Nino 1.2 is +0.2C. It is mid November and there is 0 signs of La Niña developing, every ENSO region has actually been warming lately.

Models are useful tools, but especially in the long range they are often wrong. The PDO has risen but right now it’s still nearly -2. It has been very warm so far this fall, I want cold as much as anyone but I’ll believe it when I see it. I do buy that we will see the occasional cold spell, but am skeptical that the cold stretches will last as long or longer as the warm stretches. Ultimately though, we won’t really have an idea until around mid December whether this winter is going down the warmer/less favorable path (01-02, 16/17, 21-22 would be analogs if this does happen) or the colder/more favorable path (08-09, 10-11, 13-14 as analogs if this happens). I hope I am wrong but gun to head, I would bet on the warmer path.

14-15 was pretty much the exact opposite situation. Despite ultimately being a cold and snowy winter, we had a torch December and the first half of Jan was warm too. Then we had a frigid rest of winter (2.5 months of BN temps, 1.5 months of AN). So really the torch Dec-first half of Jan was the mismatch within a large scale favorable base state (weak modoki Nino, raging +PDO).

My issue with the relying on a mismatch pattern inside a large scale unfavorable base state is it doesn’t last. Best case scenario is a 2020-2021 or 2021-2022 winter (depending on where you live), both of which had longer unfavorable periods than favorable ones. 20-21/21-22 just doesn’t move the needle. Both winters finished well AN temp wise and had limited snowpack retention. Ultimately the only real hope for a real old school New England winter (like 13-14/10-11/08-09) is a large scale change in the base state. I realize that’s fairly unlikely, but are there any cold ENSO winters you can think of that had this happen mid winter? Only one I can think of is 12-13, which torched both Dec and Jan and then was a cold and snowy Feb-Mar. I guess 14-15 but the background state was favorable going in, this is a completely different situation so I don’t see that as a possible analog even for best case scenario.

March is a winter month

I was referring to the last extended run as well as MJO forecast of another track through phases 4-6. In that run it was one week of BN temps during the first week of December before flipping warm the next 2 weeks until the run ends. The warm periods being longer than the cold periods is bad news. And it’s difficult to be optimistic when there really hasn’t been any cold during the fall.

That’s why I’m holding off for now despite things not looking good. If it’s warm the next 2 weeks but there are signs of sustained cold in the medium and long range on guidance, that’s fine. But I don’t like seeing the MJO spending so much time is phases 4-6, and most years with a similar temp and precip profile in November have gone on to be bad winters. That doesn’t mean this winter will be bad, but warmth in November and December is never a good sign. I want to see signs of a 2 week warm/ 2 week cold split rather than a 3 week warm/ 1 week cold split. The former isn’t going to lead to an amazing winter, but my area would be in the game. The latter scenario is game over. Fair point about 16-17 though. Things looked somewhat promising early and then that winter went to shit, while 12-13 was the opposite (torch Dec-Jan, cold and snowy Feb-Mar). Just to be clear, I’m not giving up on the possibility of a near average snow season even if we go down the warmer analog path. 2016-2017 was actually an above average snow winter for my area, but the snowpack retention was awful and it was +5 AN temps, so I consider that to be a F winter anyways.

I was more optimistic a month ago, but things change. It’s important to be objective and make adjustments as we get new information. There are 2 possible paths, the 08-09/10-11/13-14 one or the 16-17/01-02/21-22 one. Unfortunately, we appear to be trending towards the second camp.

Correct. Things do not look good at all, all the fall indicators looked bad. It has been very very warm so far this November, and it has also been very dry. I was holding out a glimmer of hope that the long range guidance had a clue with the shift to a -EPO pattern, but that is already looking transient. 3 weeks of warmth, a week of cold and then December starts and right back to warm. If that 3 weeks warm 1 week cold rinse and repeat pattern continues into the winter, there is no realistic hope for winter prospects in the East. You need at least a 2 week warm/2 week cold, otherwise you are relying on getting lucky in a bad pattern which is not sustainable. I’m not pulling the plug yet, too early but if I don’t see any signs of sustained cold in the next 2 weeks in the medium range I am out on this winter.

The guidance does look promising for the pacific, but I’m pumping the breaks unless we get much closer in and see no signs of the pac breaking down on the long range guidance. If that happens, I will start getting very excited. I do buy that we will have a window of a favorable pac, but if it is short lasting that will be extremely concerning for winter prospects. Too early to tell which scenario will verify.