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So true , I long for snow cover and cold temps near the holidays and the solstice. Up next is the complexity of early Jan to mid Jan.and what the sensible weather is going to be around here. Time for some cheesecake to ease the pain, but seriously, I am still hopeful though that we get our snow and cold. The idea from @psuhoffman that we get a brutal several week onslaught of winter is one such possibility that I see. Hopefully some clarity will arrive soon.

I believe you also have to re-visit what was posted a week or so ago, the up coming period, and even beyond, has a very high level of model difficulty in terms of forecasting. Many competing forces, and changes abound in certain areas of the NH.

Stir the pot in Jan possible. - AO is all I ask for. Looking at that depiction seems different from recent years, I believe. Ventrice states the ECM depiction below matches up to his precursor SSWE composite. Looks fairly close to me. Just another thing to monitor in fantasy land.

I can only guess this might be related to what @tombo82685 posted earlier that the GEFS might have this outcome because of implied coupling from the previous event in early December. Funny thing is that the GEFS is biased, I believe, in being too aggressive at times with things such as HL warming events, etc. So, maybe it is wrong in its outcome, however, as you posted psu it still accelerates the pattern flip. There is always too the possibility the GEFS has the right idea this time. IMO the environment for coupling may have merit, even if for a short duration. However, caveats apply , as stated earlier by HM with the NWP.

Will be interesting to see how things continue to progress this month and next. Two things : Granted the visual look is still warm neutral enso state. However, I believe the takeaway is more favorably placed tropical forcing is ahead , combined with a weakening + IOD and slow warming spreading East in time, along the lines of what Webb stated, hence an improving pattern .

Back to the West Pac and the Nino

Agree here, good point. This may be setting up the two different outcomes.

Can't deny the STJ so far this season........... eventually you have to think they time up correctly for us.

This period has shown interest. The vortex continues to get pressured, zonal winds are forecast to decrease as well , No SSWE on the table, more so the vortex displacements/elongations. IMHO still feel the key to getting sustained cold and snow threats is going to be the improvements in the Pac. As psu alluded to we don't require a stellar Pac later in the season, but we do need deep cold air sources and help from the NAO domain. If the Pac will not cooperate we will indeed need the - NAO domain to deliver. I like to see some really cold air build up in Canada and an improvement in storm tracks allowing us the potential for over running events. Last winter if you recall the storm tracks many times were cutters and inland runner. Let us see if we can reshuffle the cards after the warm up .

Regarding the - EPO once more ........

Snow that hangs around a bit would be cool! Also, an interesting look - like a 1960s-ish which @psuhoffman posted a while back. In those blocking winters of the 1960s winters really ramp up after the 1 st of the year. Plus, the look you posted Bob tends to fit the blocking signature in the Atlantic you find in some of the low solar min periods.

For once it would be nice for the CFSv2 to verify. Analog-wise this forecast does have some support.

In regards to the EPS we have seen it miss the -EPO previously this Fall. I recall one such event. Different ballgame this go around, but Webb states the EPS does not have a good track record with seeing the early signs of a -EPO event at times. Read that over at 33. But, BAMWX has also brought this up previously as well.

I propose the bias of both models in regards to the ensuing pattern change. The GEFS rushing things while the EPS taking too long. Ninja by WxUSAF

This makes sense. Hope it progresses. Also of interest regarding the SER

Webb believes this will happen and expects the models to go to this outcome. In play are model biases and such. He believes the progression is brought about by a combination of wave breaking and an improving Pac / tropical forcing regime, in part due to the weakening +IOD Speculating myself if maybe some sort of - EPO delivery of intense cold is going to get trapped under a block in early to mid Jan. leading to a threat window ( over-running/ clipper / colder version Miller B , etc. )

One final note about the + IOD decay. Echoes the thoughts above.

Will get more data soon but the +IOD is weakening. Really feeling this is a potential game changer. It was more than likely the # 1 pattern driver. It also causes an acceleration of the jet and interferes with ideal West Pac forcing. That looks to be slowly changing. The various modeling weakens the + IOD , but not to below the threshold value until Feb 2020 with universal agreement to below 0.4 C occurring in March 2020 I am hopeful either the weakening is more rapid, or the + IOD weakens enough to allow a more favorable West Pac regime to unfold sooner. http://www.bom.gov.au/climate/model-summary/#tabs=Indian-Ocean&region=NINO34 Indian Ocean Dipole (IOD) outlook Sea surface temperatures in the Indian Ocean have shown patterns consistent with a positive IOD event since the end of May, with the IOD index exceeding the positive IOD threshold from mid-July. The event peaked in mid-October with a weekly index value of +2.2 °C. Despite recent weakening, the latest value (for the week ending 8 December) is +0.9 °C, persisting above the +0.4 °C threshold for the 19th consecutive week. Most models suggest positive IOD index values are unlikely to return to neutral until January or February. This is much later than would typically be expected with an IOD event, and is due to the delayed transition of the monsoon trough into the southern hemisphere. This transition typically happens in early December, heralding the imminent decay of any active IOD event, but has yet to be observed in 2019.

Saw that this morning. Some interesting things going on up top, can almost see an evolution similar to November happening in Jan at some point. Ural block nice to see . Some serious cold may come over the top in Jan., similar to November. Another -NAM state accompanied by an improving Pac would be most welcomed. Looking like the table resets in Siberia and then the move is on.

If the ECM is correct regarding the MJO progression it will take some time to flip colder again, as others have mentioned here. However, this certainly does not look like some of the craziness depicted last year at this time when we started to warm up and the MJO phases were all warm, and at a high amplitude. Not to mention, the movement in those warm phases was VERY slow. From bluewave : << Next few days should be our last Arctic air mass for a while. The MJO forecast to move near phase 6 means mostly a mild Pacific influence into the longer range. >>

If this goes down again could be a plus for us. Bringing this up not because of the potential of this leading to a SSWE, ( which again I put at low odds ) but more so the benefit of anticyclonic wave breaking, etc.

They were persistent last year when predicting a cold and epic pattern, we know how that turned out, maybe they are more accurate in a warmer climate, LOL. I do think the 1960's analogs are intriguing. On a brightener note, there are some positive changes taking place. + IOD weakening, but slowly, and some hints that the vortex gets pressured again. No SSWE in sight, and if one were to occur at all this season I place my bet on Feb, or even March. Really believe the fate of significant and sustained winter period(s) is going to ride on the weakening + IOD and more robust and favorable MJO phase(s) and progressions. Also, need to achieve and maintain some sort of -AO and intervals of +PNA. Seeing the deep cold air and snow depth increases once again being modeled over Siberia is a plus for Jan. Maybe Jan evolves similar to November but a week behind and in our peak climo. The biggest tip off today might be the better trends of the AO for the second half of the month and at least not a horrible PNA. moving to neutral at least.

Good luck out there tonight !

Even though we have not had any significant snowfall in the Dc and Baltimore areas so far, it does seem the HL have been friendly and any vortex elongations , at least cold air delivery-wise have benefited the NE part of the country, including us. I hope that continues.

Good point about sources. I know various models have different ideas about the MJO progression. Some on the colder side, other warmer. I believe the ECM depiction might be the warmer phase(s). Meanwhile we have a vortex strengthening event taking place. The vortex normally fluctuates in strength, and I believe this is the time of the year when it is the strongest. I still prefer it to be weaker honestly. Also, the precursor pattern pattern that weakened it after the last ramp up , well, I am not so sure we get a healthy attack going on any time soon. I hear things, but nothing very firm. The seasonal models, as I know, called for the vortex to be on the stronger side and remain so, however that does not mean a weakening vortex can not happen in Jan. Even a SSWE can still occur later in the season, including vortex elongations, and displacement events. A lot to keep up with.