George001

I agree that there are a couple of flaws, but overall things look good. The small details will change for better or worse. If anything, the western ridge axis is a bit west of ideal for the classic benchmark track. Ideally for coastal areas we want it centered over Montana, for the Dec 5 time period it’s centered over Washington. I would actually be more optimistic for your area than mine if a storm were to pop up due to this.

I would rather have snow too but cold and dry is better than having above average temps during the winter. There is nothing worse than above normal temps during the winter. That said, one moderate snow event would make a huge difference. Given the BN temps, the snow would stick around for a while.

And even if it is just cold and dry…. That’s a hell of a lot better than the abomination we had last year. I want winter to feel like winter.

I don’t understand all the pessimism. Last fall it was justified, seasonal guidance had a torch for December and we had a raging Nino. This year we have seasonal guidance trending towards normal to below normal temps and we are in ENSO neutral. The long range guidance is COLD to start December. I try to be objective, I was pessimistic all of last winter and even in the fall my expectations were extremely low for the upcoming winter. Things look different this year. Sure, things look somewhat dry to start the month but all it takes is one storm with cold in place. The longer the temps are below average, the more likely we are to have something break our way.

The airmass is similar to the garbage we had the last 5 years yeah, but keep in mind it’s late November. The airmass is similar to late Jan/early Feb last year in November. That bodes well for later in the winter. We are already seeing some good signs with guidance trending colder for December.

Often winter shows its hand early. We are seeing signs of both a somewhat resilient Alaskan ridge regime and a strong PV regime. It’s early, but if this continues into winter it would lead to a -EPO/+NAO look.

The NAO is overrated. Yes storms tend to be more progressive in +NAO regimes, but what good is it if there is troughing out west and you are blocking in mild pacific air? You don’t need 36 hours of snow to get buried, a fast moving 12 hour storm in a cold regime can and has resulted in big snows. When I think of big east coast winter storms the first thing I think of is a Montana ridge, not Greenland blocking. Ultimately the pacific drives the bus.

I’m not a fan of the 29th threat outside NNE/elevations, but I am optimistic about this upcoming pattern and believe we will see some snow in December this year. We are seeing 2 things on the long range, persistent ridging over Alaska and a stronger than normal polar vortex. This is a completely different pattern than what we have seen the past 2 winters. We have been seeing a lot of -NAO/+EPO/-PNA. It looks like in December we are headed towards a -EPO/+PNA/+NAO pattern instead.

With no high to the north + the western ridge axis being west of ideal for east coast cyclogenesis I would favor a hugger or inside runner solution with rain for the coast and snow confined to NNE and elevations. The solution on the 12z Canadian is a good middle ground between the 12z Euro and 18z gfs. It fits the pattern.

Aren’t threats on the front end of a pattern chance usually more of long shots anyways? Even March 2018 the first threat ended up being a massive rainstorm with snow confined to elevations (Mar 2nd 2018). Some guidance buried us 5-6 days out but ultimately the airmass was too warm. The pattern change in Jan 2015 too, again the models showed us getting buried with 12-18 inches a week or so out and then the storm trended towards a hugger. The point is whiffing on the first storm after a pattern change is typical and doesn’t mean the pattern change failed or this is anything like the abomination that was the past 2 winters. Things will be different this year.

Gfs is a blizzard for December 5th

That’s the big question as to how this winter will go. I’d like to see 3 weeks minimum

It’s cold relative to the time of year

I would be more optimistic about getting snow from this storm if 1. I was not east of the low 2. it wasn’t raining outside

In regards to the winter it looks like we dodged a bullet in regards to ENSO. The rapid warming in region 1.2 is indicative of a shift toward a modoki cold ENSO pattern. That’s an unfavorable structure but ENSO is so weak it likely won’t matter, if we had that shift to a modoki but with a moderate to strong La Niña like the models showed in spring to early summer that would have been bad news. There are a wide range of possibilities, but unlike last year we are in the game. Last year was cooked from the start.

I’d rather have cold and dry than warm. At least if it’s cold and dry the ski resorts can make snow.

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.