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Thanks Don, great info as always ! As you and bluewave both mentioned it will be interesting to see whether the MJO has any effect down the road on the PV.

I prefer to simply use the AO as a guide to SECS events. Indices were not supportive. Of course, more to it than that, but a -AO is a money signal. And we all know the current NAM state.

@bluewave mentioned this possibility a week ago. Today @donsutherland1posted over at 33 that the IOD has indeed weakened even further . You can see here from the site http://www.bom.gov.au/climate/enso/iod_1.txt Would be great if Don could share his thoughts here. We are now below the threshold of a +IOD I believe. 20191125,20191201,1.14 20191202,20191208,0.86 20191209,20191215,0.82 0191216,20191222,0.56 20191223,20191229,0.31

That depiction is right along the time lines of @40/70 Benchmark, and @psuhoffman. The issues with the Pacific ridge and its location goes back to last winter. Nothing new to add. I don't care what others might say that there are differences elsewhere, that set-up is a HUGE issue and brings the SE and WAR to play. Combine that with a very +AO and a deeply -PNA and it is very frustrating. Maybe things progress later in the month, but I believe any change to better will be gradual and no one should except a sudden flip.

A wag that the NAO may be more conducive next year to negative phases, also we will be fully established with the QBO. I know Isotherm mentioned the NAO being more receptive to - phases after the solar min, target date 4/2020 . multi year SST lag to NAO domain would be two years. I also read from Isotherm we have an issue currently as well in regards to ozone concentration and the NAO domain. The context he mentioned it escapes me at the moment.

Thats the spirit , craft beers for all and for all a good night !

The current AO sums it up. The numbers and history don't lie. From Don S - here is a portion of his recent update courtesy 33andrain: << Based on the forecast strongly positive AO to start January, the probability of a significant (6" or greater snowstorm) for the major cities of the Middle Atlantic region during the first week of January is low. Since 1950, the biggest snowfall for that region when the AO was +2.000 or above during the January 1-15 period occurred during January 14-15, 1954 when Philadelphia received 3.0" snow and New York City picked up 2.0". Boston has had numerous 6" or greater snowstorms during such cases, including one 10" or greater snowstorm. Therefore, the risk of significant snow would likely be greatest over New England assuming this relationship holds (no significant offsetting variables). 　 Some of the newer AO forecasts keep the AO at +2.000 or above through January 10. If so, that development could adversely impact Mid-Atlantic significant snowfall prospects beyond the first week of January. >>

On a simple " indices only cause and effect " relationship, I will be interested to see whether anything really does materialize between Jan 7 to the 9 th or even slightly outside of that window. @usedtobe research on the - AO and its relationship to significant DC snowstorms is well known and has merit. It would then not surprise me to have various models lose the threat. Whether the threat re-emerges I am not so sure. Again, as simple as it may sound, simply basing this on an unfavorable AO phase. I know it can snow without a -AO, but it will be interesting to see how things pan out for us. Right now the AO looks horrible. If the AO trends downward then I feel the threat has more merit. Also keep this in mind form HM and Hugo

Appreciate your thoughts Wes. Wonder if the EPS reaction to pulling the ridge back again towards the end of its run is a consequence of where it thinks the MJO progression will be at that time. But, as you said, too far off to consider anything serious. Right now the highest ROI might be focusing on the period between Jan. 7 to 9 th. By that time there should be much more clarity for the second half of Jan.

Looking forward to the afternoon Euro op run today to see whether there is consistency with the robust -EPO forecast. Again, this is in the time frame of interest near Jan. 9 th.

From Ventrice regarding the high amplitude ridge set to build over the North Pac into the Aleutians. Keep in mid this development, and the progression from there is way out in time.

Some good mets and pros are thinking we really do not achieve any long lasting + PNA from here on out. As 40 70 Benchmark points out he feels it is mostly -PNA tendencies. That might work for areas North of us in a cold gradient pattern but I don't put much faith into snowfall for my area in a pattern such as that. One could speculate, with everything evolving we could morph or transition into a better Pac pattern with corresponding tendencies for a period of a +PNA, but my guess would be later versus soon. Any favorable window for cold and snow most likely would be transient in early Jan. One concern at the moment is figuring out the MJO progression for later in the month. That and the EPO will most likely guide the sensible weather here in the East after Jan 17 th in my opinion. If we were hoping for a strong West based NAO that has a real impact in our area, I would think later in the season. We may see a convoluted North Atlantic, along with continued wave breaking, but based on the NH pattern I simply feel a true West based block is a better bet in Feb. or even later. We still have a ways to go to get any cooperation from the descending QBO as well. New data will be out early next month that may shed some light on how quickly it is descending. .

Well, two things I came across that you are aware of, but cool to mention, per BAMWX. 1 GEFS is too robust in its HDD forecast at the end of its runs, at least in the last couple weeks. 2 EPS has forecasted a declining EPO several times in varying degrees, but corrected back.

It is a proven fact the EPS first identified this warm-up evolution a while back. Some thought the EPS might have been incorrect this go around, as it had previously reversed course to a colder GEFS outcome earlier in the Fall. However, the GEFS, CFS and other American models all trended to the warmer EPS solution. No surprises here, as alluded to by psu and others.

Thanks for the clarification psu. I would love a blizzard though .

Two years in a row it has been there I believe, or at least in the December to Feb months ...... You agree ?

I may be wrong with the date but one analog tossed out was 69 -70. Was that the winter which did not produce until March ? Maybe there was a blizzard in early March that year, whether we shared in it I am not sure, recall reading a post from Uncle in the NY forum.

Possibly, but we have had periods where it appeared the blocking would couple and did not, or we would experience a longer cycle of a -NAO and then it became only transient , or the MJO would proceed more normally and not spend more time in the warmer phases and then rapidly pass the colder phases. Ah, but what you said does have merit , because if everything lined up perfectly all the time our average snowfall climo would be much higher. The general warming base state the last few decades is also a bummer as well. And for the record, my perception is also clouded somewhat by frustration at times.

Exactly, keeping in mind this is my personal perspective, but have you noticed how difficult it has become the last several years in achieving a state of cooperation between the indices. You see it in the West Pac with the MJO, you see it in the Pac and the Atlantic where they never work together, you see it in the high latitudes when we do not achieve coupling. Either a string of random bad luck, or a change in things, where everything is out of alignment .

Interesting post by Simon :

Of course seasonal models looking correct at the current time, in regards to the HL. Courtesy 33andrain - I enjoy Snowy's post, here is a little regarding EAMT and the Siberian High . Snowy's thoughts seem to echo the modeling at this time. << Posted 12 hours ago Just a few notes about the East Asian Mountain Torque, we will start with the current status. We are currently in a negative EAMT. I expect a positive EAMT to develop in the next few days to counter the current negative trend for a brief moment. This would add some momentum for the first 10 days of January for the PNA domain. But it won’t last. However from about the 1st to 3rd of Jan, we will see another -EAMT come into play, and this one could be sustained for a while. This is going to reduce momentum in the North Pacific basin, and increase the forcing of Aleutian ridging, and therefore Western US troughing and Eastern US ridging. As you can see in the model guidance, the troughing over Siberia early in January weakens the Siberian High, which weakens our chances for a stronger North Pacific jet stream pattern, and for a strong Aleutian low. Based upon this, I’d forecast Aleutian ridging for much of the month of January, barring an extraordinary constructive interference. The weak Siberian High and Aleutian low also means that any forcing towards a SSW is unlikely in the foreseeable future. Hope everyone here had a good Christmas, and wish everyone a happy New Year. >>

Yes, I tend to agree, good observation. We really need something to re-set the entire SST pattern out there. Wonder what would happen if we had a moderate Nino or even stronger. We seem to be stuck with the recurring issues.

In a general sense, I see the same issues as last year, but slightly varied. Still Pac issues persist...... Modeling not seeing the SE ridge beyond day 6 but it shows up due to the crap Pacific pattern, as mentioned earlier today by bluewave Warm and wet then cold and dry - cutters, etc. West Pac SST structure not conducive, hence effecting the MJO behavior ( related to the study done on warmer phases lasting longer and colder phases lasting shorter time periods ) Fast Pac jet - continued records being set across NA and the NH Ridging and High pressure North of Hawaii - same as last year. Then downstream effects for us. Again, nothing new. Warmer SST profile too far off the West Coast of NA. - Never really looked that good, even earlier in the Fall. Nothing remarkable is evident so far regarding this December, except the continued above average rainfall. However, the AN precip is simply a consequence of the above factors. But, maybe things will change later in January. Not loosing any sleep about this winter, not worthwhile in my opinion, as I learned to lower expectations and be more rationale after last year. However, still feel a window of significant winter weather will occur in Feb and even March. Here is a recent post form Tom. From @Isotherm Note ozone concentration propensity, which is highly reflective/comports with the mean z500 structure hemispherically. Increased ozone residence over the WPO/West EPO domains will continue to promote higher geopotential heights, whilst lower ozone concentrations in the means near the North Pole/Greenland will promote the overall +NAO paradigm maintenance, prospectively. When one considers the forthcoming AAM cycling, that too, comports with the NWP's modeled Nina-esque z500 structure in the medium term.

Also of note, SE Canada maintains snow depth and the fantasy land GEFS does have a somewhat colder look for us originating from the extreme cold air mass pooling near Alaska and the NW territories and then SE towards the Tennessee Valley, NE and the Northern Mid Atlantic.

Was waiting on this update, released today by http://www.bom.gov.au/climate/enso/#tabs=Overview I am not an expert on this topic but I am surprised we have gone from 2.2 C. in mid-October to +0.6 C. as of December 24, 2019. Even further weakening is expected according to the various climate models. The + IOD threshold is +0.4 C. Now the question is how soon will the atmosphere react, so we can revert to a more conducive and assertive Pac forcing regime, not all of these weak, multiple areas of convection that continues to throw off the various MJO models. New release- issued December 24, 2019 Positive Indian Ocean Dipole weakens: The positive Indian Ocean Dipole (IOD) continues to weaken, while the El Niño–Southern Oscillation (ENSO) remains neutral. The IOD value has fallen from a peak of +2.2 °C in mid-October, to the latest weekly value of +0.6 °C. Warmer than average waters persist near the Horn of Africa, but waters in the eastern Indian Ocean are now near-average. While the index is still above the positive IOD threshold of +0.4 °C, most international climate models surveyed by the Bureau indicate the positive IOD will dissipate in January. The rate of current weakening would suggest a return to neutral is likely by early January. Positive IOD events in spring (as happened this year) are often associated with a more severe fire season for southeast Australia in the summer months. In the tropical Pacific Ocean, while most indicators of the El Niño–Southern Oscillation are neutral, warmer than average sea surface temperatures in the far western tropical Pacific may be contributing to some changes in local weather patterns over the region. International climate models forecast ENSO-neutral until at least autumn 2020. When ENSO is neutral, it has limited influence on Australian and global climate.