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Do you think we ever see this trend reverse ? And, would you speculate that it can potentially reduce the chances of an extended period of severe and durable cold weather locking in here in the East , of the magnitude we saw at times in the late 1970's ?

Wondering whether this new research has a link to warmer temps via the MJO phase progression, and the shortened period of cold, regardless of time of year, due to the fact the MJO is spending more time in the warmer phases, as the Indo-Pacific warm pool is effecting the MJO via progression and life cycle. research link https://www.nature.com/articles/s41586-019-1764-4

Interesting post by Isotherm from 33. Posted 1 hour ago Other proxies of northern hemispheric, vortex status indicate the predilection for lower-geopotential heights in the Arctic domain, but particularly the NAO domain in the means, as delineated in my outlook. November 2019 ozone data evinces generally lower concentrations near/over Greenland to the north of Europe. When juxtaposed with the mean November climatological ozone, it has generally been less extensive in those domains. Moreover, the polar vortex area is now running well above normal, circa 30 million km^2. Expansion in vortex area is generally a precursor / presages tropospheric NAM significant incline. Again, as Don alluded to above, while aesthetically pleasing stratospheric maps continue to be circulated, it's integral to examine exactly what is transpiring in the troposphere as far as the veridical data. SPV intensity diminution doesn't always correlate directly to tropospheric vortex status.

I am looking at zonal winds at 10 mb. But, as you mentioned , and also brought up by HM indirectly, is this set-up forecasted by both the Euro and the GFS. On a side note, I have not looked today, but hearing the wave 2 follow-up may not be as significant then first thought for early to mid- December. A lot will change moving forward, no worries there yet.

And yeah, steady as she goes .....

The way things are going right now with the vortex is probably the best outcome, more or less. Speculating that we don't have a major SSW in December, ( at least that is what the current modeling shows and echoed by some strat experts ) Sometimes the rare very early season SSW can interfere with things and many times the vortex recovers. Having any type of major SWWE later versus early can possibly extend our winter weather potential. Of course, we would have to be lucky in that respect and be the area of focus. And, I know you know this poolz1 , but we have already experienced a minor warming and it appears yet another minor warming is anticipated in the first half of December. So things are looking good a bit down the line. Oh, and for the record, I feel robust blocking returns and coincides with a split flow pattern, leading to a memorable period of winter storms in January and beyond.

I hold no real value in the CFS, but I appreciate your post. I too have seen it actually be in the forecast month and calling for significant warm anomalies and the country is already cold and only getting colder. Maybe use it for trends and know it is extremely volatile. Never hang your hat on the CFS, unless maybe you are attempting bias in your point of view. Same thing for the weeklies. However, I still believe we warm up prior to favorable changes in the MJO, and other factors. Using lagged MJO composites and relevant analogs there seems to be a good case for blockiness to reestablish itself in early January, ( maybe as early as the last week of December ) along with another -NAO interval. Some of these analogs indicate the cold locking in and persisting in time. The greatest -EPO in these are Jan targeted and the deepest -NAO is mid Feb.

According to Don S it is entering the time period when it is more skillful. Well, I am not sure verification from this date, November 27 for the next month, but I believe we are still going to warm up in time for the holidays. As for how warm, and how long, still hard to say. We lose the - EPO so maybe Pacific based air mass floods the country the third week of the month. I am liking January and Feb.and even March, the new winter month, thinking March holds above normal winter weather promise this go around.

Wish HM would pop in and chime in on that map, from a HL point of view. . I might want to guess and say it looks at 500 as a precursor pattern for further vortex weakening.

Very true, it has been so long that we have had all the players working for us in our favor. ( ie. the 50/50 or a -NAO leading to a HA event, etc. ) I miss the Big Dogs ! The atmosphere may want to cooperate this winter.

Thought I read this might be related to the SST profile up there. Over the summer when we had the periodic bouts of -NAO it was mentioned the cold pool was responsible. Do you have any thought on it psu? Secondary guess would be wave breaking, but not sure. And yeah, love seeing this.

The 50/50 is so important for our area it is featured among DT's checklist of MECS. I know he loves focusing on the QBO, but when he goes down his list of key features needed for the big ones, the 50/50 is always talked about in detail. The throwing rice at a wedding thing was a good one ...... I love these HH runs !

Some mets are looking for their return this winter. As mentioned a while back, some pros and certain seasonal winter forecasts have mentioned better odds this winter of Alberta clippers, etc., would love a Manitoba Mauler that cripples the Northern Mid Atlantic. As for where have they gone, seems since we had that massive warming in the Pac a few years back , it has been sort of blah, just speculation really.

Frequent coastal storms and even this development here points to an active winter in the East according to a few mets, and I am beginning to believe it more and more. If those whom are calling for even transient -NAO blocks in our favored areas this winter are correct, we might be very happy snow-wise during our better climo period. Between varying the NAO domain state, and more than likely having an occasional split flow pattern / active STJ moisture, should present opportunities for us.

The sudden ensemble upswing of the AO to about +4 SD is now forecast a few days later to get back close to neutral. Would love to see some sort of dive again during December with the AO, but at least we are not going to experience a raging positive AO that lasts a while, which would be a huge concern, as already discussed here in depth. Meanwhile the vortex is still getting pressured and it appears that continues. Again keep it weak. Any official SSWE is always uncertain in terms of outcomes such as coupling and areas that are effected...... yada yada yada There is a secondary warming being projected with decreased zonal winds being forecast. I am anxiously awaiting the new QBO data, I believe it will be issued early next month. Hopefully we are not stalling, but still declining. It will be of interest to those who are looking to the QBO correlations to other years, such as 1995. On on a quick solar note, we remain at very low levels of activity, although solar wind parameters are expected to become slightly enhanced today.

HM pondering whether the numerical modeling will react the same as they did in the old days, 10 years ago he said they ( the models ) would trend colder outcomes as we get closer to the event. One thing of note, he did not mention, but I see floating around is snow cover in Eastern Canada, and to our far North, is above normal, vast and has decent depth. A good way to deliver cold air South. Hey, I I'm in for any early December snowfall, that is always a good sign.

Well now, liking the looks of this. All I ask for is putting pressure on the vortex. Following your "good vibes " post there @showmethesnow Things look interesting again. Hoping we follow up with wave 2.

Wow, so how early do the " big spenders " get to see the Euro weeklies. Out already, normally I look for 6:00 PM. release. And yes, the trend is your friend ! Looking forward to seeing the progression.

Bob, if the Atlantic side improves, in terms of the positioning of the block, do you think we see the ULL in future runs dive further South and Southeast? Looks like the Pac is OK in a general sense, but the Atlantic is lacking. Move the block further South and a bit West and could see some improvements. So far ahead to have any confidence I would imagine at this point. There seems to be a lot of chaos going on up North, lots of moving parts you could say. The funniest thing of all is this entire concept is built upon the concept the GFS at 150 hours, has any clue at 500 mb.

Many times the state of the AO in December provides clues to the AO state for Jan and Feb. Having measurable snow in our area, such as DC and Baltimore during December , normally correlates to a decent snow season. Works many times, of course there are exceptions. Also, you will hear how things just are not syncing up like they use to. Some signals you look at would have you assume winter will be normal, but then the pattern head fakes and we go very warm.

All hail @Isotherm, that is his call and progression to a T . The tropics impact the higher latitudes and blocking. He and a couple others called this a month ago. Hey, but no winners yet, as it is Nov. 24 th not Dec. 24th. However, as Bob stated, the trends with the AO are very concerning. If we reverse and empty all the cold air in Canada and lose snow cover up North, it will take weeks to recover. I myself speculate, once we get to mid January, we diverge from last year and go very cold and very stormy. I might buy Tom's progression for December, but I feel there is a decent opportunity this winter for some cold powder storms and high ticket snow events.

Great update, I hope we eventually see some positive signs in the HL. Seeing some +4 to +5 AO ensemble members is a bit worrisome, and the recent 4 day trends continues more so positive. Noticing these huge bowling bowls moving across the country with that fast Pac jet is reminiscent of last winter to a degree. Alaska is set to record a fast Pac jet up there this early week. Another thing to watch, and I believe there is a statistical correlation here to our area from DC North is that having a + PNA in December is key to accumulating snowfall. Maybe more so than a -AO. That relationship probably changes in January. So difficult lately getting the PNA to go + and remaining so. I love to see the Pac and the HL align down the road. If you go HM's route there is hope in December.

There does seem to be some changes this year in the far Eastern Atlantic and the far North, but you are correct the forcing pattern is very similar. Is is true we are still suffering from a lack of coupling, or it that becoming a mute point with the meager Nino. It also seems we are losing the Modoki SST pattern in the Pac as well, the East region warms 1.2 , and the West region might be cooling soon. Also, seeing some changes too regarding the sub surface SSTs in region 1.2 ( Do you concur with this ? )

Not to mention the previously discussed Modoki Nino is fading, to a degree, and the presentation in the Pac is declining overall. We may be in for an extended period of poor Pac and poor Atlantic, on top of the changes in the HL. Seems in the last few days medium range models maybe going to route of the seasonal models. Of course this can all change, but the trends the last couple of weeks in the Pacific are concerning.

Yes, that is true. But, it is uncanny how similar to last December we look to evolve, but there are other players around that could throw a monkey wrench in the way December eventually plays out. I know some are using the MJO progression, and the standing wave, as way to maintain the warmer phases, Some are calling for the HL to become less favorable as well. Still seeing the pesky High North of Hawaii. If it were not for the - EPO we would be in trouble even faster . At least the -NAO helps us for a bit before it weakens. So hard for Decembers to work out in our favor if you love snow and cold, been that way for a long time.