EasternLI

End of the eps seems pretty phenomenal. 

Schenectady smokeshow right now. 

https://wnyt.com/article/12543/

Solid moderate snow here with a coating on everything. 

Light snow has commenced in Riverhead. 

That euro run is about as good as it gets for a forum wide event. Let's do it. Lock that in. 

12 hours ago, EasternLI said:

LOL

 

LOL

I like ensemble means at this range. They all seem to strongly suggest a close to benchmark system. The 18z gfs looks well within the spread of the individuals of ensembles. The other operational models too, for that matter. Will be interesting to watch unfold. 

40 minutes ago, Typhoon Tip said:

What is this based upon ? 

This tells us nothing... I see a cross-hair axis with no units and squiggly line... 

Is it modeled ...or observed - 

what is this ...

NOAA's just released/updated the 30 mb QBO and it has increased westerly phase intensity to 11.15  ... up from 10 in October.  That's ending November 30 - 

Here is the yearly trend:   

2020   -2.51   -3.20   -4.36   -5.03   -4.86   -2.78    0.34    4.78    7.95   10.80   11.15 -999.00

That's one of the Singapore daily readings. Those are quite noisy from day to day. The graphic itself comes from the really nice NASA qbo page. 

https://acd-ext.gsfc.nasa.gov/Data_services/met/qbo/qbo.html

26 minutes ago, bluewave said:

We can probably thank the very warm SSTs over the IO for the more Niño-like pattern. The IOD never made the strong drop that we typically see with a La Niña of this strength. So the MJO is going into the circle after moving through the IO P2 and P3 phases. Notice how much those LR forecasts look like a P3 at the beginning of December.

 

Agree with the warm IO. It's problematic. Exasperating the situation is the QBO this year it looks like. Being westerly,  coupled with a la nina, it's just not an ideal situation. All of these things combined looks to keep forcing "trapped" in the IO for the most part. It's why the euro weeklies have been showing the awful pattern moving forward. (Yes, the weeklies have been abysmal at times. The problem is, there's research to support them in this case.)

Combined effect of the QBO and ENSO on the MJO

https://www.tandfonline.com/doi/full/10.1080/16742834.2019.1588064

The QBOW phase, however, will suppress the MJO intensity over the Maritime Continent through enhancing the diurnal cycle; plus, there is no reinforcement of the MJO over the western Pacific because of the cold central Pacific of La Niña. Thus, the MJO rarely reaches the western Pacific during the La Niña/QBOW phase (Figure 3(d)).

14 hours ago, snowman19 said:

@bluewave @Allsnow @donsutherland1 Good thread by Griteater, but a VERY bad sign: 

 

Nice post. It could be a part of a Vortex Intensification event (VI) as is described in the following paper. If so, would be terrible news for any -AO prospects. Here's a couple of relevant quotes from the paper. The life cycle of such events, if that's what is indeed occurring, can be up to 80 days. 

Stratosphere‐troposphere evolution during polar vortex intensification

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005JD006302

Reduced poleward planetary wave heat flux occurs as the circumpolar wind becomes strongest and pressure anomalies penetrate toward the surface. Descending pressure patterns project strongly onto the positive state of the Northern Hemisphere Annular Mode (NAM).

Between days −20 to +20, reduced poleward heat flux is observed as the vortex becomes strongest; increased poleward heat flux is observed as the vortex recovers.

[41] In our preliminary examination, the anomalous vortex intensification seems to occur preferentially during La Niña conditions.

On 11/13/2020 at 6:13 PM, LibertyBell said:

What I want to know is why would the Indian Ocean have more weight on the NAO pattern (why is it warming more quickly?) than either the Pacific or Atlantic would?  What exactly is the Indian Ocean doing and do the Pacific and Atlantic have an influence on the Indian Ocean too?

 

It's a great question. I'm quite sure the answers are much more complicated than what my current understanding is. I am aware of a few things though. I don't have the data to back this up right now, but there is some relationship with the Indian Ocean and ENSO. Through Ocean current and rossby waves also I believe. Not sure about the Atlantic. I haven't seen anything about a relationship there. Why is it important in regards to the NAO? Mainly, because forcing there strengthens the PV, as it pertains to this year specifically. The following paper describes why that is an issue. 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL084683

The state of the stratospheric polar vortex has a clear impact on the NAE (Scaife et al., 2005) weather regimes (Charlton‐Perez et al., 2018). NAO− is most sensitive to this stratospheric state, occurring on 33% of days following weak vortex conditions but on only 5% of days following strong vortex conditions

The same paper also goes into what to look for if we're hoping for an increased opportunity for some -NAO. As it relates to MJO activity combined with different ENSO states, La Niña for this year. Naturally, other factors are always at work as well to determine what the end result is. In any event, it would seem that we would really like to see the MJO be active through phases 7+8.

We find that the MJO–polar vortex–NAE pathway is strongly active during La Niña years (Figure 3c), particularly for the weakened vortex following MJO phases 8 (corresponding to the third pentad after phases 6–7 in Figure 2), associated with the low in the northwest Pacific following MJO phase 7, increasing vertical heat flux to the stratosphere. There is also a weakened vortex closely following MJO phases 7–8 during neutral years. These contribute to the increased NAO− occurrence around phases 7–8 during neutral and La Niña years (Figure 1).

Published: 12 November 2020
An earth system model shows self-sustained melting of permafrost even if all man-made GHG emissions stop in 2020

https://www.nature.com/articles/s41598-020-75481-z

In this paper we report that in the ESCIMO climate model the world is already past a point-of-no-return for global warming. In ESCIMO we observe self-sustained melting of the permafrost for hundreds of years, even if global society stops all emissions of man-made GHGs immediately.

A potential for a shift away from the IO down the road a bit. Maybe. Could shakeup things a bit hopefully.

12 minutes ago, LibertyBell said:

Is it me or did we just begin talking about the Indian Ocean a few years ago?  It seems like before, say, two years ago, the Indian Ocean wasn't even talked about- as if what happened there didn't matter to global patterns?

 

As far as I can tell, there just wasn't that much research on global effects in the past. There was a lot of research on more localized effects. It's gaining more attention more recently though. Probably because it's identified as an area with anomalous warming trends. 

As was brought up earlier in this thread, research says Indian ocean convection will strengthen the PV. The following 2 tweets are related. You can see anomalous negative VP in the Indian ocean first. Signaling anomalous convection. Secondly, the strengthening PV. Quite impressively actually. 

Nice outlook Isotherm. I think it's even more optimistic than what I was thinking. Hopefully it verifies. 

16 minutes ago, bluewave said:

Yeah, it may be the warming of the tropical Indio-Pacific Basin that drives Rossby wave driven warming further north in the Pacific. There have also been some recent papers that have linked the reduced Arctic Sea ice with the tropical patterns in the Pacific. So these 500 mb patterns get stuck over the NPAC and warm the waters below. We have seen quite a bit of this since the rapid Pacific Basin warming in 2013. So we get multiple areas of near record  tropical SST warmth interacting with the varying ENSO conditions.There have been some novel combinations of IOD, WPAC, MJO, and ENSO states. The warmer than expected La Niña temperatures for us this November with the moderate to strong La Niña and +AAM is just one of many over the  last few years. Each year it seems to be some different combination. Like the WPAC warm pool preventing the El Niño from coupling in 18-19. Last year it was the record IOD which may have amped up the PV leading to the very strong +EPO/+AO/+NAO . This was followed by the record SST warming north of Australia and record MJO 4-6 activity. 

Some great points. Makes a lot of sense. Perhaps a good cautionary tale of using any older analog years. The arctic sea ice issue is interesting. Something I would like to do some more reading on. I think it's one area that is gaining popularity in research. The QBO has had a good amount of attention recently.

6 hours ago, bluewave said:

Right now, that warm pool seems to be giving us a warmer pattern that we would usually get with a La Niña in November. So a combination of different influences teaming up for a warmer than expected solution. 

 

Oh I am in full agreement on your point here. My post was in reference to the tropical pacific warm pool. Which can drive a favorable winter pattern for us. Instead, the models are locked in on the Indian ocean. Which can drive a terrible winter pattern for us. But the current state of the QBO gives support to what the models are showing IRT that. As far as the North Pacific warm pool. My thinking is that it's more of a indicator of what the pattern had been. Not necessarily a driver of much. Maybe more of a modulator? I just feel like those anomalies can be bullied around by what the tropics are doing as that is where the most energy (heat) resides. I feel like this winter is going below average snow maybe way below, much above average temp. Not seeing much for winter fans to be excited about TBH.

10 hours ago, bluewave said:

Great post. The quick reversal from -AO in October to +AO in November is something that we normally see during an El Niño. This may be related to lingering neutral to positive IOD which is also more Niño-like. The IO standing wave the models have for November was implicated in the very strong PV and +NAO +AO last winter. The current +PMM with near record SST warmth north of such a strong La Niña cold tongue is also a first for a La Niña.  A very warm November has also been associated with El Niño’s in the past. Several times this warm November during an El Niño carried over into December. So such an occurrence this year would be different than the typical front loaded La Niña winter progression. There have also been several very warm La Niña Novembers followed  by warm Decembers. On the other hand, a warmer PMM was present for our most recent La Niña warm November in 2016. That was a near record warm winter. But it may have been the +PMM allowing occasional poleward extensions of the North Pacific Ridge into Alaska. Those were also accompanied by short -NAO -AO episodes for respectable seasonal snowfall despite the record warmth. There are many factors this year which could interact. We may just have to wait and see how things look in another month or so. But even beyond  the specific ENSO conditions and interactions, we have just seen the warmest 5 winter stretch on record. 

Predictability of European winter 2019/20: Indian Ocean dipole impacts on the NAO

https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/asl.1005

 

Thanks. There's certainly a risk of a very warm winter ahead. I'm not overly fond of anything that I'm seeing at this time. The Pacific warm pool (associated with the PMM) could help us out, but will it? That's one area of very warm water. The other is the Indian ocean, which is what models are keying on right now. 

Interestingly, the MJO to -NAO connection is strongest in La Niña years. 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL084683

The NAO− regime teleconnection via the stratosphere from MJO phases 7–8 is most enhanced and occurring latest during La Niña years, while it is suppressed during El Niño years.

Unfortunately, it seems that the QBO is working against us here being westerly. Suppressing convection where we would prefer to have it. 

https://journals.ametsoc.org/mwr/article/147/1/389/103189

As MJO events propagate eastward over the MC during boreal winter, static stability anomalies increase in magnitude over the eastern MC and WP. That is, static stability anomalies decrease during QBOEM and increase during QBOWM, corresponding to a less stable atmosphere and increased RMM amplitudes over the eastern MC and WP (RMM phases 5 and 6) during QBOEM, and a more stable atmosphere and decreased RMM amplitudes over the same region during QBOWM.

This is what the GEFS and EPS is showing for VP200. The new EPS weaklies today continues this look right into December. Research says that Indian ocean convection will drive a strong polar vortex. Last year is a great example of that occurring. I didn't give that enough respect. So expecting a ++AO La Nina as of now unless something changes here and quickly. 

The west pacific warm pool is of some interest this year IMO. It's something that I will certainly be paying attention to in looking at the sst trends in that area in the month ahead. This relates to the discussion of the PMM in the discussion thread. 

There's potentially some optimistic outcomes that could (or could not lol) stem from this as it relates to the winter ahead. Some recent research has shown that forcing in this area can actually drive an Aleutian low +PNA pattern during winter. Which in turn can act to cause a weak SPV. It should be interesting to monitor this area moving forward. 

Nonlinear response of Northern Hemisphere stratospheric polar vortex to the Indo–Pacific warm pool (IPWP) Niño https://www.nature.com/articles/s41598-019-49449-7

During boreal winter, anomalous SST warming associated with IPWP Niño can excite NH extratropical teleconnections that project onto the positive phase of the Pacific–North America (PNA) pattern in mid–high latitudes, intensifying the upward propagation of planetary waves into the stratosphere and, in turn, warming and weakening the NH stratospheric vortex41. Note that the wave pattern excited by IPWP Niño is located further west than the PNA pattern, a fact that may be related to the different wave source locations from that of ENSO.

@bluewave

That's very interesting about the PMM October pattern. I didn't even think to look at that for some reason. I remember we discussed that in the past. I found that particular pattern interesting when it was first showing up on ensembles. So I dug into some Nina years to look into it a little. I had some difficulty finding anything. Which I guess suggests the rarity of it. I see 1995 was brought up a few pages back. That was actually the closest match I could find. Albeit, it didn't happen until the end of the month that year. Therefore the composite for the month as a whole looks different. Interestingly, it's almost a mirror image of the PMM pattern composite you posted.

46 minutes ago, CAPE said:

That oddity in the regular cycle in 2016-17 really stands out. Makes one wonder if that sort of thing will become more prevalent. I suppose it could have simply been related to the strong Nino during that period, or maybe a sign of things to come.

Yeah, I've seen a couple papers that attributed it to the super Nino. A more recent paper goes into some greater detail. I can't help but wonder if the powerful +IOD event last year played some role in the odd behavior of this year. 

https://acp.copernicus.org/articles/20/6541/2020/

In addition to the anomalous behavior in the tropical lower stratosphere in 2015/2016, we explored the forcing of the unusually long-lasting westerly zonal wind phase in the middle stratosphere (at 20 hPa). Our results reveal that mainly enhanced Kelvin wave activity contributed to this feature. This was in close relation with the strong El Niño event in 2015/2016, which forced more Kelvin waves in the equatorial troposphere. The easterly or very weak westerly zonal winds present around 30–70 hPa allowed these Kelvin waves to propagate vertically and deposit their momentum around 20 hPa, maintaining the westerlies there.

Interestingly enough, the qbo that year actually was westerly below 30mb to the tropopause. This year actually looks to do that as well albeit with a thicker vertical profile. Also interesting in that 2007-08 was completely different then this year. Merely a couple observations. Cheers.