December 2021

[bluewave]

The models want to continue the record breaking fall +EPO pattern that we have been discussing. They also are intensifying the the polar vortex and taking the AO and NAO positive. The record +EPO and Pacific Jet seem to be stronger than any of the individual MJO and La Niña composites suggest.

 

 

[snowman19]

7 minutes ago, bluewave said:

The models want to continue the record breaking fall +EPO pattern that we have been discussing. They also are intensifying the the polar vortex and taking the AO and NAO positive. The record +EPO and Pacific Jet seem to be stronger than any of the individual MJO and La Niña composites suggest. So the MJO composites and December La Niña analogs may not be the best forecast tools to use at this time. There is something bigger going on that past analogs aren’t picking up. Perhaps, it’s the various marine heatwaves occurring that we don’t have analog composites for.

 

 

This is an extremely well coupled La Niña/-PDO/-PMM system in place right now: 

 

[snowman19]

1 hour ago, binbisso said:

Today's teles and MJO forecast  look better than recent days they now have the MJO going into phase 7 And while the AO/NAO trend positive they look to bring it back to neutral.  I know Snowman 19 feels and I agree with him that the MJO will have a tough time getting  into favorable phases, however  I do think that with  The colder temps now established in regions 3 and 1.2 we have a chance to get convection over or near the date line. We shall see

The La Niña driven easterly trades are absolutely roaring up to the dateline. Any MJO wave that tries to propagate into phases 7, 8 is going to get ripped apart and sheared to shreds 

 

[MJO812]

MJO is going into 7 and 8 on gefs. Cold air will be here just in time for prime time season in December .

[SnoSki14]

1 minute ago, MJO812 said:

MJO is going into 7 and 8 on gefs. Cold air will be here just in time for prime time season in December .

I would hold off on that until we enter December. Don't like the continued +EPO and strengthening Alaskan vortex. 

Also lack of Atlantic blocking is concerning.

[jm1220]

2 minutes ago, MJO812 said:

MJO is going into 7 and 8 on gefs. Cold air will be here just in time for prime time season in December .

We’ll have to see if it can actually get there and stay there. Not sure if someone can bring up whether it’s been predicted recently and never got there. 

[jm1220]

1 minute ago, SnoSki14 said:

I would hold off on that until we enter December. Don't like the continued +EPO and strengthening Alaskan vortex. 

Also lack of Atlantic blocking is concerning.

We need whatever help we can get from the NAO. The record cold SST west of Canada are definitely not what we want. It’ll keep trying to build a trough there especially after Dec when climo Nina gets more hostile. 

[MJO812]

9 minutes ago, SnoSki14 said:

I would hold off on that until we enter December. Don't like the continued +EPO and strengthening Alaskan vortex. 

Also lack of Atlantic blocking is concerning.

We said the same thing about early December and there is barely a warmup. We go through being nervous every single winter 

 

[MJO812]

6 minutes ago, jm1220 said:

We need whatever help we can get from the NAO. The record cold SST west of Canada are definitely not what we want. It’ll keep trying to build a trough there especially after Dec when climo Nina gets more hostile. 

Yep 2nd half will be key for blocking 

[MJO812]

Long ways out but 2 runs in a row where the gfs opens up the arctic flood gates.

 

[MJO812]

Barely a warmup on the 0z gfs. A storm signal around December 5th keeps  showing up. Long ways out though.

[snowman19]

@bluewaveStill a firehose PAC jet in the long range as far as the eye can see. It shows no signs of letting up. It also looks like the +EPO has established a positive feedback loop due to the super cold GOA/severely -PDO and the extremely deep snowpack over all of Alaska. It’s just continuing to manufacture it’s own extreme cold there due to the very heavy snowpack and lack of sun, Alaska is setting all kinds of cold records

[MJO812]

5 minutes ago, bluewave said:

Looks like the first week of December will be a continuation of the November pattern. The extended guidance wants to develop more of a zonal flow week 2 as the PNA flattens out. But the fast Pacific flow +EPO remains the common denominator. 
 

Nov 29 to Dec 6

 

Dec 6 to 13

 

It's hard to take the long range seriously when it keeps changing .

[KEITH L.I]

1 hour ago, bluewave said:

The EPS weeklies have been very consistent. This forecast issued on November 15th is almost unchanged. So the expectations were always that the November pattern would linger into the first week of December.

November 15th forecast for first week of December lingering November pattern

They are accurate 2 weeks, weeks 3 and 4 they are not..like basically most long range forecasts past 2 weeks

[SnowGoose69]

8 minutes ago, KEITH L.I said:

They are accurate 2 weeks, weeks 3 and 4 they are not..like basically most long range forecasts past 2 weeks

Some years they have remarkable accuracy at 3-6 weeks...others they'll just keep trying to revert to the seasonal climo or expected ENSO pattern and be wrong

[SnoSki14]

MJO very borderline. Doesn't look very strong, signs it may slink into 7

[MJO812]

Dec 5 time-frame keeps popping up

[KEITH L.I]

1 hour ago, SnowGoose69 said:

Some years they have remarkable accuracy at 3-6 weeks...others they'll just keep trying to revert to the seasonal climo or expected ENSO pattern and be wrong

In my years following the weeklies, many years they would have it cold and snowy Christmas week and it turned out balmy in the 50's. I wouldn't trust it past 2 weeks

[snowman19]

3 hours ago, MJO812 said:

Dec 5 time-frame keeps popping up

It’s been popping up and that storm is going to cut. No -NAO block to stop it from cutting, no -AO, and the phantom +PNA is going to disappear and flatten out with the PAC jet crashing into it. The GFS, CMC, Euro, GEFS, GEPS, EPS all have it as a cutter and with good reason 

[MJO812]

24 minutes ago, snowman19 said:

It’s been popping up and that storm is going to cut. No -NAO block to stop it from cutting, no -AO, and the phantom +PNA is going to disappear and flatten out with the PAC jet crashing into it. The GFS, CMC, Euro, GEFS, GEPS, EPS all have it as a cutter and with good reason 

Wrong

[MJO812]

Models get really cold after the storm in early December around the 5th.

[EasternLI]

If accurate, December is going to get pretty interesting IMO with a look like this. Really liking some things I'm seeing as of late. Haven't been able to say that in a while. 

[Mr. Kevin]

2 hours ago, EasternLI said:

If accurate, December is going to get pretty interesting IMO with a look like this. Really liking some things I'm seeing as of late. Haven't been able to say that in a while. 

Could you briefly elaborate please? Thanks in advance 

[dmillz25]

1 minute ago, Mr. Kevin said:

Could you briefly elaborate please? Thanks in advance 

That blue in SA is forcing (mjo) is convection in phase 7/8 I’m not mistaken. Usually leads to a trough in the east coast with blocking

[EasternLI]

Yes, what dmillz said. Looks phase 7 ish to me. That has legit potential to ignite a -NAO too. Perhaps phase 8 after? 

[snowman19]

2 hours ago, EasternLI said:

Yes, what dmillz said. Looks phase 7 ish to me. That has legit potential to ignite a -NAO too. Perhaps phase 8 after? 

How is it going to propagate east into phases 7, 8, 1, with the easterlies screaming from the Niña all the way to the dateline? They are going to shear the wave to shreds: 

 

[EasternLI]

6 hours ago, snowman19 said:

How is it going to propagate east into phases 7, 8, 1, with the easterlies screaming from the Niña all the way to the dateline? They are going to shear the wave to shreds: 

East QBO plus La Niña favors eastward propagation of MJO events.

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

During a La Niña year (Figure 3(c,d)), the effect of the QBO dominates. For each La Niña/QBOE year (Figure 3(c)), there are 1.7 MJO events, which is much larger than that in an El Niño year and La Niña/QBOW year. The last phase has only 0.6 MJO events (Figure 3(d)). During a La Niña/QBOE year, the MJO can propagate to the western Pacific without being suppressed over the Maritime Continent. During a La Niña/QBOW year, the existing MJO is observed to be enhanced over the Indian Ocean, while it is barely able to pass the Maritime Continent (Figure 3(d)).

[wdrag]

10 minutes ago, EasternLI said:

East QBO plus La Niña favors eastward propagation of MJO events.

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

During a La Niña year (Figure 3(c,d)), the effect of the QBO dominates. For each La Niña/QBOE year (Figure 3(c)), there are 1.7 MJO events, which is much larger than that in an El Niño year and La Niña/QBOW year. The last phase has only 0.6 MJO events (Figure 3(d)). During a La Niña/QBOE year, the MJO can propagate to the western Pacific without being suppressed over the Maritime Continent. During a La Niña/QBOW year, the existing MJO is observed to be enhanced over the Indian Ocean, while it is barely able to pass the Maritime Continent (Figure 3(d)).

Interesting counterpoint... good to have this further discussed, if there is any other science.

[wdrag]

In the mean time???  Maybe I'm wrong, but another climate forecaster pointed out what appears to be a developing stratwarm in nw NAM the next couple of weeks (GEFS).  Is it true?  AND,  the impact on USA weather?  Presuming the same delays here as always at least 2-4 weeks after occurrence (late Dec?).  I am curious. Need something to jar this pattern back to something eventually more favorable for winter (after this -NAO disappears next week). 

[EasternLI]

27 minutes ago, wdrag said:

Interesting counterpoint... good to have this further discussed, if there is any other science.

Here's another interesting more recent article. This is focused more solely on the qbo modulation of the MJO - NAO response. Interestingly to me, the reanalysis composites had a more favorable orientation of the -NAO response during EQBO than during WQBO years.

https://www.tandfonline.com/doi/full/10.1080/07055900.2021.1944045

The results can be summarized as follows:

MJO Phase 3 in WQBO winters

The observations show a statistically significant positive NAO as do seven of the ten models.

MJO Phase 3 in EQBO winters
The observations show a positive NAO signal, which is not quite large enough to be statistically significant at the 5% level. Only one model shows a statistically significant positive NAO signal.

MJO Phase 7 in WQBO winters
The observations show a negative NAO that is significant at the 5% level. Only one model produces a significant negative NAO.

MJO Phase 7 in EQBO winters
The observations show a negative NAO signal that is not quite large enough to be significant at the 5% level. Four of the ten models produce a negative NAO signal that is significant at the 5% level. It should be noted that the observational signal, while not quite significant, is larger than that of the models with a significant signal, which may be related to sample size and variance.