Evidence for global regime shift mounting

[Hailstorm]

I agree w/ the idea that the next week to 10 days will stay pretty cold up there, but definite warming occurs by week 2. Maybe Wes is looking at different data, but from what I can see, even 10 hpa is warming.

Thanks for your thoughts. Your first post in this thread is very insightful, by the way. I just hope that a +PDO develops in tandem with the potential stratospheric warming in early January; and that the MJO emerges into a favorable phase by then. If we get all that to develop, I think we will be looking golden, especially if we still have much above-normal snow cover in Canada and Siberia by then.

[NJwinter23]

Excellent write up as always. I do believe too that we ought see a pattern change at least begin around jan 1st. As for the current pattern, there seems to be some long term Nina lag occuring from last years moderate Nina as same held true during Dec, Jan of last year when we were experience the 2009/2010 Niño like - NAO/AO conditions during its moderate Nina. Also last year as you mentioned we had the favorable low solar activity. Not so much this past fall with arora's being seen as far south as Geogra. I suspected those were the kiss of death to the early forecasts of early mid Dec blocking, but unlike last year, the QBO is more favorable. Can this enhance any SWE and resultant blocking? Along with the last month or so of a return to less solar activity, shouldn't the QBO and low solar compensate for any lack of SWE should one not occur? Correct me if I'm wrong, thanks.

I'm definitely not the best person to answer your question, but I will say that we have had a reigning +QBO regime in the lower stratospshere into the early winter here, not favorable...The anticipated more favorable -QBO you mention and many were expecting to take over this winter has yet to propogate downward enough. I suppose if you mean that the EVENTUAL -QBO this winter is more favorable than last year, then ok. However, you might want to read what mitchnick was getting into above

If you look at the first post, it seems that solar activity is on the decline.

Good read though

Yes but I think what mitchnick is saying is that our clinging westerly/+ QBO in the lower stratosphere has timed with high solar activity here in the early winter and hence helped strengthen this +AO regime...and the prospects exist that we get the lower solar activity advancing forward in the later winter timed with the -QBO finally taking over...From the paper he posted, this opposite combination in late winter has also been linked to a strengthened +AO regime. I've heard others voice this concern, including HM, but it's just something to consider at this point. I'd have to think we'd be extremely unlucky if that panned out and screwed us the entire winter. Right now most I've heard from are still on board for a nice -AO regime for a good period in Jan/Feb..And of course the relatively speaking decline in sun activity and a warming stratosphere will have the largest say in that

And great post by the way Iso!

[Isotherm]

Thanks for your thoughts. Your first post in this thread is very insightful, by the way. I just hope that a +PDO develops in tandem with the potential stratospheric warming in early January; and that the MJO emerges into a favorable phase by then. If we get all that to develop, I think we will be looking golden, especially if we still have much above-normal snow cover in Canada and Siberia by then.

Thanks, but unfortunately we're not going to get a +PDO developing this winter and the MJO likely won't be favorable either. These are two things I'm much more confident about - the PDO is a relatively stable index compared to the NAO/AO, and the former has been in a mod/strongly negative state since last summer, and we're in the midst of a weak-mod Nina event right now. The probability of the PDO switiching from negative to positive this winter is pretty close to 0 I'd say. With that said, IMO, cold PDO's are much more efficient in getting arctic air into the US as we've got a colder globe overall. Some of the US's coldest patterns have been when every index is in its negative state: -PDO, -PNA, -EPO, -AO, and -NAO. You'd basically get major blocking connecting from NW Canada across the top of the globe and widespread low heights underneath in East Asia, Europe, and North America.

[Isotherm]

I'm definitely not the best person to answer your question, but I will say that we have had a reigning +QBO regime in the lower stratospshere into the early winter here, not favorable...The anticipated more favorable -QBO you mention and many were expecting to take over this winter has yet to propogate downward enough. I suppose if you mean that the EVENTUAL -QBO this winter is more favorable than last year, then ok. However, you might want to read what mitchnick was getting into above

Yes but I think what mitchnick is saying is that our clinging westerly/+ QBO in the lower stratosphere has timed with high solar activity here in the early winter and hence helped strengthen this +AO regime...and the prospects exist that we get the lower solar activity advancing forward in the later winter timed with the -QBO finally taking over...From the paper he posted, this opposite combination in late winter has also been linked to a strengthened +AO regime. I've heard others voice this concern, including HM, but it's just something to consider at this point. I'd have to think we'd be extremely unlucky if that panned out and screwed us the entire winter. Right now most I've heard from are still on board for a nice -AO regime for a good period in Jan/Feb..And of course the relatively speaking decline in sun activity and a warming stratosphere will have the largest say in that

And great post by the way Iso!

Thanks, and I agree with your more detailed analysis on the QBO. It's turned negative up to 30mb but has not yet propagated downward completely. I also agree that the combination of lingering +QBO and the burst of solar flux/geomag activity we had this autumn aided in strengthening the arctic polar vortex hence a +AO. There are definitely signs on all modelling now that the +AO vortex of death finally begins self-destructing by day 10 or so. Stratospheric warming will be in full progress overtop Siberia, Canada, Alaska, into part of the arctic by day 10; however, that will take another 2 weeks or so to have full effects on sensible weather, taking us to early January.

As stated before, the pattern is Nina-ish for the next week to 10 days, but the +PNA pulse by week 2 sets us up for a cold Christmas-News Years period at least. Wouldn't be surprised if we got some snow out of that 12/20-12/31 period.

[earthlight]

It is definitely concerning that the stratospheric warming is having some serious trouble getting going. It seems to me that the pattern is pretty settled in right now. The Polar Vortex has generally been comfortable over Greenland and the Davis Straight since late August and September. We saw a brief flip in this pattern in late October (and we received a historical event, what a surprise). Up to this point, however, this current setup has been nearly opposite of what we experienced last year at this time and moving forward. Remember that last year, the pattern didn't begin to shift until the very end of January into February.

The stratospheric warming we saw over the past few days was more than likely a low spike. It definitely was not a SSW event -- which is probably what we would need to flip this pattern in faster than 3 weeks or so. Even then, we would probably be well into January before we began to see results. You can see in the below image the warming at 30mb which we saw over the past week or so...which has since moderated and plateaued. In addition, the forecasts (not taking them as absolute, just noting) keep the entire thing fairly mundane through the end of the period. Take note, also, that we are a good distance below the 30 year running mean for 30mb.

With the highly unfavorable PDO and MJO phases poised to remain in place over the next two to three weeks -- and little help being offered from the high latitude blocking with the lack of any SSW to help retrograde the entire upper air pattern over that area -- it appears that the pattern could remain generally unfavorable for snow through the middle of January at the very least.

Many people's winter forecasts hinged on the development of some high latitude blocking towards the middle of January -- and there is still plenty of time for that to occur. As Isotherm noted the solar developments are favorable for that to occur eventually. But where we stand right now, it doesn't look like we'll have much to write home about through the holidays. There is always the chance that we could sneak something in, we have seen snow in very unfavorable patterns before. In fact, over time, I think we will sneak something in. But the longwave pattern doesn't look to be changing until mid January.

This doesn't bode well for me, obviously, since my initial forecast from October was for the beginning of the pattern change to occur around December 15th. This simply isn't going to happen right now -- and to be quite honest I don't understand why some professional forecasters continue to hit the idea of cold and snow conditions in the east towards the end of the month. I don't see anything supporting that. Isotherms idea of a change in 3 weeks has much more credibility to it -- but at the present time I might lean a little later than that as far as when we will begin to see results.

[NJwinter23]

Thanks, and I agree with your more detailed analysis on the QBO. It's turned negative up to 30mb but has not yet propagated downward completely. I also agree that the combination of lingering +QBO and the burst of solar flux/geomag activity we had this autumn aided in strengthening the arctic polar vortex hence a +AO. There are definitely signs on all modelling now that the +AO vortex of death finally begins self-destructing by day 10 or so. Stratospheric warming will be in full progress overtop Siberia, Canada, Alaska, into part of the arctic by day 10; however, that will take another 2 weeks or so to have full effects on sensible weather, taking us to early January.

As stated before, the pattern is Nina-ish for the next week to 10 days, but the +PNA pulse by week 2 sets us up for a cold Christmas-News Years period at least. Wouldn't be surprised if we got some snow out of that 12/20-12/31 period.

Can't argue there. Colder air continues to expand southward and wavelengths continue to elongate heading into late December. Even with all things remaining equal from the past 1-2 months that produced the warmth, you would think/hope this would at least somewhat alter the pattern at some point for the better even if it's not going to be from a AO/NAO going negative sense. I think that could be a bit of what we see in these final 10 days of the year (the "how can it get any worse" mentality I guess). I'm certainly not predicting a snowy pattern by months end, but like you said, it wouldn't be crazy if we started getting some minor events or more appreciable mix/changeover events in that time period.

And while I'm not positive, I believe the likes of HM and most would tell you that what's going on in the stratosphere in the next 10 days is a wave 1 response from Asia. It's not a significant warming event that will catapult us into -AO heaven by any means, but it's at least something to disturb that strong/cold son of a b**ch finally. I think there is also some other weak warming projected?/going on? higher up at 10mb that is unrelated...Regardless, I get the impression that even if we dont move into a -AO regime immediately in the next few weeks, these are at least signs that we have turned the corner from the worst and are looking up towards better times.

[Alpha5]

these are at least signs that we have turned the corner from the worst and are looking up towards better times.

lets be honest....how could it be worse

[NJwinter23]

lets be honest....how could it be worse

Well I did acknowledge that belief in the first paragraph.

[Weathergun]

lets be honest....how could it be worse

I think with all uncertainty and mixed signals we are getting from the QBO,SW, MJO,and the sun, we should just take anything better setup that we can get. I would be fine just a good -EPO.

Nice disco, Isotherm.

[Isotherm]

It is definitely concerning that the stratospheric warming is having some serious trouble getting going. It seems to me that the pattern is pretty settled in right now. The Polar Vortex has generally been comfortable over Greenland and the Davis Straight since late August and September. We saw a brief flip in this pattern in late October (and we received a historical event, what a surprise). Up to this point, however, this current setup has been nearly opposite of what we experienced last year at this time and moving forward. Remember that last year, the pattern didn't begin to shift until the very end of January into February.

The stratospheric warming we saw over the past few days was more than likely a low spike. It definitely was not a SSW event -- which is probably what we would need to flip this pattern in faster than 3 weeks or so. Even then, we would probably be well into January before we began to see results. You can see in the below image the warming at 30mb which we saw over the past week or so...which has since moderated and plateaued. In addition, the forecasts (not taking them as absolute, just noting) keep the entire thing fairly mundane through the end of the period. Take note, also, that we are a good distance below the 30 year running mean for 30mb.

With the highly unfavorable PDO and MJO phases poised to remain in place over the next two to three weeks -- and little help being offered from the high latitude blocking with the lack of any SSW to help retrograde the entire upper air pattern over that area -- it appears that the pattern could remain generally unfavorable for snow through the middle of January at the very least.

Many people's winter forecasts hinged on the development of some high latitude blocking towards the middle of January -- and there is still plenty of time for that to occur. As Isotherm noted the solar developments are favorable for that to occur eventually. But where we stand right now, it doesn't look like we'll have much to write home about through the holidays. There is always the chance that we could sneak something in, we have seen snow in very unfavorable patterns before. In fact, over time, I think we will sneak something in. But the longwave pattern doesn't look to be changing until mid January.

This doesn't bode well for me, obviously, since my initial forecast from October was for the beginning of the pattern change to occur around December 15th. This simply isn't going to happen right now -- and to be quite honest I don't understand why some professional forecasters continue to hit the idea of cold and snow conditions in the east towards the end of the month. I don't see anything supporting that. Isotherms idea of a change in 3 weeks has much more credibility to it -- but at the present time I might lean a little later than that as far as when we will begin to see results.

John - good post, but not gonna lie - this is probably one of the more depressing narratives I've seen from you lately. I think I have more confidence on the solar card helping big time, as I don't believe an official "major" stratospheric warming is necessary to change the pattern. In that way it sounds like I'm more optimistic at this point that the pattern transition begins the last week of December and changes entirely by early January.

Solar values really falling off a cliff. Lastest 12/12 update has solar flux now fallen to 130, and SSN into the 50s. Both values lowest/one of the lowest we've seen over the past few months.

I

[NJwinter23]

John - good post, but not gonna lie - this is probably one of the more depressing narratives I've seen from you lately. I think I have more confidence on the solar card helping big time, as I don't believe an official "major" stratospheric warming is necessary to change the pattern. In that way it sounds like I'm more optimistic at this point that the pattern transition begins the last week of December and changes entirely by early January.

Solar values really falling off a cliff. Lastest 12/12 update has solar flux now fallen to 130, and SSN into the 50s. Both values lowest/one of the lowest we've seen over the past few months.

I

And that ap index came in at 5 last month...certainly clear signs that we are hitting a relative valley in sun activity during the overlying increase towards solar max..Can only help for now

[NYCSuburbs]

Are there any analog winters where the stratosphere was this cold for this long? With the current pattern considered, I'd think that other analogs with a stratosphere consistently cold were warmer/less snowy than average.

[NJwinter23]

Are there any analog winters where the stratosphere was this cold for this long? With the current pattern considered, I'd think that other analogs with a stratosphere consistently cold were warmer/less snowy than average.

I think 99-00 would be a match...but not positive

[mitchnick]

I think 99-00 would be a match...but not positive

a few similarities with 99/00 and this year, at least wrt ENSO

[NJwinter23]

a few similarities with 99/00 and this year, at least wrt ENSO

Yes... but that month December 99 was just insanely warm everywhere.

[okie333]

1978 is a good match at 500mb for November.

[Absolute Humidity]

1999/2000 did feature the surprise Jan 25 Hecs over NC, VA and DC, was barely a Mecs up here but given the prior 3 years before that, Jan 25 2000 was a monster. That winter produced 22" snow IMBY, slightly below average, but not bad.

[NYCSuburbs]

1978 is a good match at 500mb for November.

The East looks similar, but there's big differences in Canada, Alaska and the NE Pacific, where that November apparently had more ridging near Alaska that was missing this November:

These differences increase into December, as Dec 1978 also wasn't a persistently cold and snowy month for the East, but the 500mb especially over Greenland is far from a match to this December:

The 1999-00 analog NJWinter23 mentioned isn't perfect, but there do appear to be some similarities. That winter also had a delayed start with the snow, with a trace of snow in Central Park in December.

[Isotherm]

Yes... but that month December 99 was just insanely warm everywhere.

Compared to this month...most of the US cold:

[NJwinter23]

Compared to this month...most of the US cold:

Yeah I was posting that map to prove that it really isnt a great comparison at all. Outside of the 2nd year ENSO match and the strong stratospheric PV, I would not try and run with that analog

[NJwinter23]

1999/2000 did feature the surprise Jan 25 Hecs over NC, VA and DC, was barely a Mecs up here but given the prior 3 years before that, Jan 25 2000 was a monster. That winter produced 22" snow IMBY, slightly below average, but not bad.

Hmm I guess I also remember that winter in a favorable light because of the jan 25th surprise storm as well as a few inches that fell on the 19th-21st time period. However, that winter was atrocious nation wide outside of those 2 weeks in late Jan. There is some optimism to draw out of that year though, since we did get a memorable 2 week period despite how terrible the entire climate regime was in the late 90s surrounding this moderate la nina year. I firmly believe we will have a much better window (in terms of time) for winter weather this year than in 99-00. This is especially true for the U.S. as a whole west of here

[Isotherm]

Posted this in the main thread, but will repost here as well.

Pretty impressive warming showing up right up through the 1-10 hpa layers. Note in particular drastic reversals over Siberia, AK and Canada over the next 7-10 days.

[Isotherm]

May not officially be classified as a "major" warming, but this would be sufficient to disturb the PV and begin the destruction process of the raging +NAO/AO. Of course the sensible weather effects would be 2 week minimum later, putting the January 5th-20th period in target for major arctic invasion into the US.

[earthlight]

May not officially be classified as a "major" warming, but this would be sufficient to disturb the PV and begin the destruction process of the raging +NAO/AO. Of course the sensible weather effects would be 2 week minimum later, putting the January 5th-20th period in target for major arctic invasion into the US.

This is impressive. Would likely turn the tables by week 4 if it were correct and assuming it didn't halt there.

[BxEngine]

This is impressive. Would likely turn the tables by week 4 if it were correct and assuming it didn't halt there.

This should probably go in the meteorology 101 section, but since its already here, oh well. What exactly causes warming that isnt "sudden"? It was explained to me a bit, though I think I understand more of what would cause a SSW more than just minor warming. Is it the same principle, just on a smaller scale?

[Weathergun]

Posted this main forum already. The ECMWF now forecasts 10hpa and 30hpa warming to about average, in 10 days. Particularly at 90N. Good sign for changes in the high latitudes to begin at the end of this month:

[Isotherm]

Posted this main forum already. The ECMWF now forecasts 10hpa and 30hpa warming to about average, in 10 days. Particularly at 90N. Good sign for changes in the high latitudes to begin at the end of this month:

Agree, very good sign. Today's data still indicates a pretty healthy warming event from 100 hpa right up through 1 hpa. Some in the main forum are still discounting it as impressive but I think it's certainly an important game changer for us, in conjunction with the lower solar values. Probably not a major warming but sufficient to perturb the arctic PV.

[Snow_Miser]

Positive anomalies are starting to become more evident in Western Siberia at 50 hPa, which could signify that a potential stratospheric warming event is about to take place in the Arctic, but at 10 hPa the stratosphere has warmed less when compared to the 30 and 50 hPa anomalies, which means that not all of the stratosphere has begun to warm up quite yet.

The positive anomalies start to expand in western Siberia near December 9th at 50 hPa.

[TheTrials]

Euro does try to bring higher heights towards greenland at the end of the but it still looks very transient. There is a huge pig ridge out in the middle of the atlantic that is just begging to burst north but the AO just won't let it. We need the AO to give.

[bmc10]

Euro does try to bring higher heights towards greenland at the end of the but it still looks very transient. There is a huge pig ridge out in the middle of the atlantic that is just begging to burst north but the AO just won't let it. We need the AO to give.

Yep I made the same observation. Several runs of the gfs have show the same thing. Temporarily higher hgts progressing into Greenland only to be squashed.