so_whats_happening

Yep but you also need to watch out for too early of an SSW, especially if it is not a major event, as there will be recovery before the final warming takes place. So anything before January and you run the risk of losing February snow potential with a recovering SPV. There is a sweet spot needed in not only the wave activity but timing.

I would be awfully careful about SPV forecasts that far in advance. You can typically start to see it on models in the 15 day but it is recommended to wait for 10 days max. You want extensive wave breaking events in the troposphere to help create the waves along the SPV rim. It also is nice to Urals blocking occur as this usually is an early indicator something may be on the way. You also want to see more than a wave 1 flux happen, wave 2 is the desired for many of us in the east which means the atlantic/european side needs to get involved and this has been an issue over the years. It is also important to remember that just because an SSW may be occurring does not mean it affects us in the same manner we think it will. I have some papers i can share from over the years when i get to my computer. As bluewave said it is rather rare to see anything happen before the new year, typically it is after mid january we see enough wave activity to induce a warming event whether it be a mid grade warming or a major event.

I wonder if there is a connection of +AMO and -PDO phase and vice versa, also when they are in tandem +/+ or -/-. I never really took the chance to see if this was something or not and since they are multi decadal oscillations im curious if there is something to it like when we have an extremely +AMO do we tend to have more -PDO?

It takes some time for things to work through if we do hit that threshold even. If anything 3 should warm up more so than 3.4 but we shall see. As far as trimonthlies to get to that range for NDJ, as you mentioned where peak would be per your thoughts, we would need to have 3.4 sustained around 2.1-2.2 for the rest of November and hold that for three full months. We have yet to see sustaining effects after each warm up period we tend to get this warmth to surface and then 2-3 weeks after it dies off and begins to cool. Maybe this time is different? To be quite honest I don't see this being an issue going forward, forcing is still establishing much further west than a typical strong borderline super El Nino would be. 2015-16 was further west than 97-98 and it seems like that type of trend may continue with this event in forcing location.

Here is the CPC update through much of October the 30th should update next week.

Here is the latest TAO/Triton from mid October to the most recent. Not much changed in the beginning portion of October from 1st-15th area but look was overall similar to what it looked like on the 15th. You can see the shifting of the warm pool under western 3.4 and 4 starting to shift eastward and connect with the thermocline dropping down further east. Not much change in overall surface temps in the east thus far and if we are to it will be in the next two weeks with a push of warmer waters. This will be the push to 2C that I mentioned before, how long it stays there is very dependent on what happens with wind forecasts. It looks like mid November to mid December may be the 2C timeframe after that it may be more just about sustaining those anomalies than rapidly deepening but will have to wait and see. Of note the WPAC subsurface is gaining some steam too so this very well could be the last push of this Nino for more warming episodes but again will have to wait and see for the full reaction of this KW. Forcing still looks to hold up around the dateline with some spottiness in the far EPAC.

@Terpeast So I went and just did a quick june-august look in the northern hemisphere. I mean it kind of does speak for itself in the 15 years leading to 2007 and 15 years after 2007. No real rhyme or reason to the dates. I'm sure if we did it into 5-10 year bins we would see the changes occur.

This could be explained by the drastic shift down in ice volume around that time. Just a thought of course.

We need the Atlantic/European side to cooperate too don't want a large scale wave 1 displacement when something does take hold.

Yea my bad went into the monthly break down and saw the 14" listed there thinking it was 13-14. Went back and edit the mistake was year off on both those references.

Yea 21/22 (i believe this was more se this year than s, jersey shore delaware folks) was also another year where they got hit quite a bit. Rough being nearly 60 miles straight shot and getting half the snowfall.

I was referencing lancaster area we had 13" that year.

If we did the same thing and used years where from ASO to peak (typically peak was OND averaged out) was less than .5 increase for all strong/super ninos we get a slightly different look. Lets see what happens coming up here as far as increases go in the next two months since there is a lag, a later peak may be more beneficial than we think.

Anyway back to ENSO with October probably coming in around 1.6 for the monthly we should have an ASO reading of around 1.5. Now looking back at all the El Nino years from this point on to their peak where we saw large increases in 3.4: 1957-58: saw .5 increase from ASO reading to DJF peak (1.8) 1972-73: saw .5 increase from ASO to OND/DJF peak (2.1) 1982-83: saw a .6 increase from ASO to OND/DJF/JFM peak (2.2) 1987-88: saw a .5 increase from ASO to NDJ/DJF peak (1.2) 1991-92: saw a 1.1 increase from ASO to DJF peak (1.7) 1994-95: saw .5 increase from ASO to NDJ peak (1.1) 2009-10: saw .9 increase from ASO to NDJ peak (1.6) All other years had below .5 increase from ASO to their respective peak values most falling in the .3 increase between the two timeframes. Using only the strong and super years since we are relatively close to both in this current setting. All had a warm December, again not big surprise (not super warm but warm). January was cold south warm north, active track across the country. February turned rather cold for most in the east and offered a fantastic storm track setup. Now this is basing off the idea of strong/ super Ninos that experienced increased warming past their ASO numbers greater or equal to .5 increase.

Yea weird stuff ignoring ENSO state looking at 1953-54 +AO/NAO led to a warm winter while 1957-58 was -AO/NAO period led to really cold conditions in the east, something we would typically expect. 1953/54 had average snows while 1957/58 had close to double the season snowfall. Missed western ridging during both those years, when it did show up it was rather mundane. While checking out 13-14 and 14-15 both had extensive west coast/BC ridging even with -NAO/AO in 13-14 and +NAO/AO in 14-15 both winters probably the coldest we have seen in quite some time. 2013/14 had double the snow across the area while 2014/15 had a normal seasonal total. This was definitely a weird time opposite of what we would typically expect snowfall wise. 2009/10 had some deep -NAO/AO times but very little in the way of west coast ridging except for some around Alaska. This was our snowiest winter recorded. I feel we had a discussion about this not too long ago. -NAO helps funnel cold, doesn't create it just allows it to have more impact in the east, if the cold is there, -NAO also slows storm track if we can get the typical 50/50 to develop too (we didn't see that last winter). Western ridging knocks the cold into the US this can be seemingly changed up by a very positive EPO as shown in 1957/58 creating a pseudo ridge warming pattern in the BC region even without an actual full ridge pattern. In all of this we can just see snowfall is wayyy too variable of a thing versus saying the winter can be colder or warmer based off these years. As for precip anomalies that probably more so depends on the ENSO/PDO state at hand. Edit: gotta fix my 13/14 and 14/15 mistake. -NAO/AO produces big for our area if they both are working in tandem. +AO/+NAO is a lot more variable. -AO is the key more than -NAO for a cold winter while -NAO allows better snow potential given a -AO.

We could honestly sit there and say that about a lot of things in weather. There are things though that do allow forecasters the ability to foresee some of these events. So while actual values (severity) will differ one can see a pattern leading up to -AO/-NAO regime or +AO/+NAO regime just like we can see in advance poleward fluxes that may induce sudden stratospheric warming episodes. It isn't perfect but it can clue folks in on what may be to come given these circumstances evolving. Just like we have had nearly 150 page discussion on ENSO state. I believe many years ago it was postulated that a warmer Arctic would more often than not induce a -AO regime definitely has not been the case though. We seem to have periods where +AO is more likely (string of rather +AO years) than -AO but to determine much outside of that would be rather tough. I do wish folks would use parameters as guidance and not certainties just like I hope one day people use guidance (computer models) as well guidance, but here nor there.

Personally hope the troposphere remains detached from the SPV like we have seen off and on over the years. When it connects on either end it really connects so fingers crossed we don't develop a +AO this year early on.

I honestly hope I have the bolded correct it really has been like 5 or so years since I really dove into it. I should also mention it more so is a concentration of O3 increases with a disturbed PV versus a stronger PV which spreads out O3.

Im honestly unsure what the effects could be as well as many others are unsure. We clearly have not had something this profound in our recorded history, so to say with certainty one thing will happen over another is a bit much. One thing that needs to be noted is water vapor helps destroy O3 in the stratosphere (may be a reason as to why the southern hemisphere ozone hole grew again?). It has been awhile since I did any type of diving into the stratosphere and SSW but if I remember correctly there is more O3 present during a more disturbed PV with less during a stronger PV. So one could argue since the destruction of O3 is occurring due to a large increase in WV in the stratosphere it would allow for a stronger PV. This was a neat read though. In it a large increase in water vapor was noted to have a more northward jet signifying the potential of a stronger PV due to this. https://www.sciencedirect.com/science/article/pii/S1631071318301184 It should also be noted that -QBO years tend to allow Rossby waves to transfer poleward more easily causing disruptions to the PV over time. So it seemingly sounds like a mix bag situation right now. Blocking highs may counter balance the negatives of increased water vapor allowing more concentrated heat fluxes to the poles this year but we are still early and discussion of this outside of December onward is guessing at best. I would wait until close to the new year to see what may come about.

Throw in a little bit of 2015 Pacific pattern as well with the dual weak lows very similarly placed and ridging NW of Hawaii, ridging along the west coast. Big difference in the NAO domain though, I believe during that time were in the descending phase of solar which does promote a more +NAO regime if I remember folks in here pointing out. Again never perfect but interesting to say the least.

DCA: -.5 NYC: 0 BOS: 0 ORD: +.2 ATL: +.4 IAH: +.6 DEN: +1.2 PHX: +1.7 SEA: +.8

I mean there is a point to be made that there is some similarity to 97 atmospherically right now. Biggest difference that stands out is the higher heights on the west coast/ BC region which were the exact opposite in 1997. That will certainly be something to continue to watch as we move forward. Maybe a weaker Aleutian version of 1997 would make for an interesting year. There are some other flavors of Super Nino mixed in there from past events. Edit: had to go and emphasize some because a few may misconstrue the idea.

This seems to be an ongoing theme of late the troposphere kinda doing it's own thing from time to time and the Strat trying to couple but failing do so more often then not.

Did from mid month to the most recent plot. Looks like we finally are getting a more pronounced cooling look in the WPAC. We are shifting the anomalies located around the dateline eastward and having less of a cool pool under 3.4. Still nothing major to speak of as of yet but this does help explain the slight uptick in Upper ocean anomalies @GaWx had posted about the other day. I do not believe we will go over the last two peaks we saw but this will allow for warmer waters to spread out a bit more again giving that probable push close to 2C through November for 3.4. Still not seeing it go much above that as we move forward and I think we would need an East propagating WWB event to occur in time if something can manifest itself to push north of that 2C mark.

Fairly good, it is not recommended to go past hr 240 though.