ENSO Discussion

[Webberweather53]

Thanks for the explanation. Which charts do you find best to track these equatorial rossby waves? I know the kelvin waves can be seen with the anomalously warm ocean temperatures propagating eastwards. 

 

Carl Shreck and Mike Ventrice's sites are my two favorite places to go to monitor eq Rossby Waves in real-time!

 

http://mikeventrice.weebly.com/hovmollers.html

 

 

https://ncics.org/portfolio/monitor/mjo/

[Black Hole]

Carl Shreck and Mike Ventrice's sites are my two favorite places to go to monitor eq Rossby Waves in real-time!

 

http://mikeventrice.weebly.com/hovmollers.html

 

 

https://ncics.org/portfolio/monitor/mjo/

Thanks! Appreciate the help. Trying to become much more well versed in this stuff.

[Geos]

Cooling very evident now.

 

 

Not particularly impressive looking!

 

[snow_wizard]

Cooling very evident now.

 

 

Not particularly impressive looking!

 

 

Yup...the atmosphere simply isn't on board.  The 30 day SOI is decently positive right now and the current MJO position favors further rises.

[Front Ranger]

I disagree. I think there's a good shot at a major cold wave into the U.S. in mid November, and another one by late December.

 

So far, so good.

[SilverFallsAndrew]

So far, so good.

 

Really impressive shots of cold air into the middle and eastern part of the country so far this month. A lot of record lows on the Southern Plains the other day and probably more in the next few days. Widespread snow across Kansas and Oklahoma with this system this morning which is very unusual for this early in the season. 

[TT-SEA]

Any analogs for warmish neutral ENSO and low solar with significant cold air in the middle of the country in November?

[Front Ranger]

Really impressive shots of cold air into the middle and eastern part of the country so far this month. A lot of record lows on the Southern Plains the other day and probably more in the next few days. Widespread snow across Kansas and Oklahoma with this system this morning which is very unusual for this early in the season. 

 

Currently 26 with snow and northerly winds gusting to 35 mph in Amarillo, TX. 

[SilverFallsAndrew]

Currently 26 with snow and northerly winds gusting to 35 mph in Amarillo, TX. 

 

It's probably a little more common this time of year out in Amarillo as opposed to Tulsa. 

[Front Ranger]

Any analogs for warmish neutral ENSO and low solar with significant cold air in the middle of the country in November?

 

1986

1976

 

That's about it. Solar is lower this year, though. And +ENSO was more established in 1986.

 

Also, both those years had raging +PDO, while we're currently in a neutral PDO regime.

[Phil]

1986

1976

 

That's about it. Solar is lower this year, though. And +ENSO was more established in 1986.

 

Also, both those years had raging +PDO, while we're currently in a neutral PDO regime.

Eh, looks like a +PDO to me (albeit weaker) and both of those were solar minimum years.

 

Biggest difference is ENSO, ironically. Niño 3.4 has dropped back below 0.5C again. Lots of intraseasonal variability this year.

 

[Front Ranger]

+PDO was in full control both of those years, not so this year. I think that is key for the state of the North Pacific citculation this time of year.

And yes, both those years were solar min or just after, but overall activity was higher. Especially 1986.

[Black Hole]

+PDO was in full control both of those years, not so this year. I think that is key for the state of the North Pacific citculation this time of year.

 

And yes, both those years were solar min or just after, but overall activity was higher. Especially 1986.

Will you put out a winter outlook this year?

[Front Ranger]

Will you put out a winter outlook this year?

 

Been meaning to. It's a difficult year, but feel like we have enough info now...hopefully I'll have time to throw something together this week.

[Black Hole]

Been meaning to. It's a difficult year, but feel like we have enough info now...hopefully I'll have time to throw something together this week.

I will if I have time as well. Not feeling too excited about prospects this winter but I don't think it will be as terrible as say 2014/15 was. Less of an extreme +PDO should help. 

[Webberweather53]

As I alluded to a while back, I thought the atmosphere was clearly behaving like an El Nino and further put forward that +AAM in the subtropics wasn't just a temporary poleward propagating anomaly attributable to subseasonal variability because it persisted through multiple bouts of Indian Ocean/eastern hemisphere forcing. It should be pretty obvious to everyone now it's ENSO related and here to stay, the atmosphere clearly looks like what you'd expect in an El Nino. 

 

http://gsdmsolutions.com/~gsdm/clim/daily_total/glaam.sig.90day.gif

[Phil]

How is poleward +AAM propagation (or any meridional transfer of AAM) an ENSO descriptor?

 

I consider it to be a budgetary function related to instabilities triggered by the seasonal cycle, QBO, and extratropical mechanics/MTs. Meridional transfer of AAM happens every year, even if it’s initial structure is state dependent (IE: ENSO related).

[wx_statman]

How is poleward +AAM propagation (or any meridional transfer of AAM) an ENSO descriptor?

 

I consider it to be a budgetary function related to instabilities triggered by the seasonal cycle, QBO, and extratropical mechanics/MTs. Meridional transfer of AAM happens every year, even if it’s initial structure is state dependent (IE: ENSO related).

 

I'm out of my league here, but isn't +AAM tied to +ENSO via reduced trades over S. America? Lighter zonal wind means less resistance against the Andes, allowing the Earth to spin just a little bit faster. Therefore, more AAM is transferred poleward compared to non-El Nino conditions. Is this not what "Webberweather53" is talking about? Just curious.

[Geos]

Still around that +0.5 mark.

 

 

No real organized look as we approach the typical peak intensity of el Nino's.

 

[Phil]

I'm out of my league here, but isn't +AAM tied to +ENSO via reduced trades over S. America? Lighter zonal wind means less resistance against the Andes, allowing the Earth to spin just a little bit faster. Therefore, more AAM is transferred poleward compared to non-El Nino conditions. Is this not what "Webberweather53" is talking about? Just curious.

You’re correct about the AAM integral/sign, but I wouldn’t consider the cycles of meridional AAM transfer to be ENSO-induced. That happens literally every year and it’s technically triggered by a combination of extratropical torques/wavecycles and intraseasonal elements of higher frequencies than that of ENSO. The *sign* of the AAM anomaly that’s propagating is related to ENSO/low frequency tropical forcing, but not the propagation itself.

[Webberweather53]

How is poleward +AAM propagation (or any meridional transfer of AAM) an ENSO descriptor?

 

I consider it to be a budgetary function related to instabilities triggered by the seasonal cycle, QBO, and extratropical mechanics/MTs. Meridional transfer of AAM happens every year, even if it’s initial structure is state dependent (IE: ENSO related).

 

How could it be "poleward" AAM transfer if the +AAM anomaly literally hasn't moved poleward in several weeks & remained present through multiple bouts of subseasonal variability.

 

Again to reiterate so maybe this will finally hit home, this AAM anomaly has indeed remained virtually stationary in the subtropics and we've seen multiple rounds of subseasonal variability in the tropics, you seem completely lost.

 

It's not mostly related to subseasonal variability or happens every year as you're asserting especially to this degree. When it lasts through multiple forcing cycles & continues intensifying in spite of them and doesn't propagate poleward despite subseasonal forcing arguing it should have otherwise, the anomaly is ENSO related, large, and and it's not moving out of the subtropics anytime soon as long as we're in that phase of ENSO (El Nino).This +AAM anomaly has moved poleward about 5 degrees in a span of nearly 45 days, that's not distinct poleward, subseasonal propagation no matter how you much you want to spin that in your favor.

 

So I'm also guessing we see+2 sigma AAM anomalies "every year" in the subtropics too? Yeah ok...

 

[Webberweather53]

You’re correct about the AAM integral/sign, but I wouldn’t consider the cycles of meridional AAM transfer to be ENSO-induced. That happens literally every year and it’s technically triggered by a combination of extratropical torques/wavecycles and intraseasonal elements of higher frequencies than that of ENSO. The *sign* of the AAM anomaly that’s propagating is related to ENSO/low frequency tropical forcing, but not the propagation itself.

 

That's not necessarily true in every case or year for that matter. Subseasonal forcing agents can trigger these anomalies but that doesn't actually say anything about how ENSO influences the subseasonal forcing and actually flies completely in the face of what's currently happening if you're trying to assume what we're currently seeing is mostly subseasonal because it's clearly not.

[Webberweather53]

Despite being a super NINO there are many great examples of poleward AAM propagating due to subseasonal forcing. They typically propagate 30-45 or more degrees poleward in a span of nearly as many (or less) days and do so over the course of 1 subseasonal forcing cycle, notice this is nothing like what we're seeing now because our +AAM anomaly in the subtropics has hardly budged in the last 45 days even after the MJO & concomitant CCKWs have run their course multiple times in every place in the global tropics. Again, it's not subeasonal forcing.

 

http://www.atmos.albany.edu/student/nschiral/research/gwo/ncep_ncar_archive/1997.png

[Phil]

How could it be "poleward" AAM transfer if the +AAM anomaly literally hasn't moved poleward in several weeks & remained present through multiple bouts of subseasonal variability.

 

Again to reiterate so maybe this will finally hit home, this AAM anomaly has indeed remained virtually stationary in the subtropics and we've seen multiple rounds of subseasonal variability in the tropics, you seem completely lost.

 

It's not mostly related to subseasonal variability or happens every year as you're asserting especially to this degree. When it lasts through multiple forcing cycles & continues intensifying in spite of them and doesn't propagate poleward despite subseasonal forcing arguing it should have otherwise, the anomaly is ENSO related, large, and and it's not moving out of the subtropics anytime soon as long as we're in that phase of ENSO (El Nino).This +AAM anomaly has moved poleward about 5 degrees in a span of nearly 45 days, that's not distinct poleward, subseasonal propagation no matter how you much you want to spin that in your favor.

 

So I'm also guessing we see+2 sigma AAM anomalies "every year" in the subtropics too? Yeah ok...

 

That looks like a clear low frequency/seasonal scale poleward propagation to me. You should be able to filter for it quite easily (if it’s not already obvious to the naked eye).

[Phil]

Niño 3.4 has dropped below 0.5C again, with another trade burst on the horizon.

 

So, was that earlier spike in SSTAs meaningful, or not? To be honest, I think my interpretation was correct.

 

And SSTAs evolve slowly? That’s a new one for me. The subsurface certainly evolves “slowly” by comparison, but how that translates to the surface depends on the nature of wind stresses/hydrostatic coupling, which remains unimpressive.

I'm not going down this rabbit hole with you again. Yeah they actually do if you looked at the e-folding scale of the anomalies, there's a significant subseasonal component but most of the variance is explained over periods of several months or more. It's supposedly unimpressive yet we're getting SSTAs > 1-1.5C in the NINO 3, NINO 3.4, & NINO 4 regions of the tropical Pacific & the thermocline is suppressed enough to support a borderline moderate-strong El Nino. Again you're living in denial lol

Well, I guess we’ll find out eventually.

And the SSTAs themselves are pretty bouncy, even if their boundaries are preconditioned over longer periods of time. Personally, I try to avoid extrapolating from them on timescales like this.

The reason the SSTAs are this high is mainly related to low frequency variations in the thermocline and the warming is occurring simultaneously w/ an easterly trade wind burst over the basin atm as tropical forcing shifts into the Eastern Hemisphere. Hence, this doesn't look like a temporary change.

[Webberweather53]

Niño 3.4 has dropped below 0.5C again, with another trade burst on the horizon.

 

So, was that earlier spike in SSTAs meaningful, or not? To be honest, I think my interpretation was correct.

 

 

You also mean your "interpretation" about this event peaking now? Or how about this head fake into an El Nino? We all know how the latter panned out...

 

Yep, there's a trade wind burst east of the dateline in the coming week but WWBs will return as the forcing enters the western hemisphere, you conveniently left out that last part.

 

 

 

Remote wind stress forcing of SSTs is stronger than local wind forcing east of the dateline, those WWBs near the edge of the warmpool will trigger a Kelvin Wave response & it'll be interesting to see how that's realized in the grand scheme of things 

[Webberweather53]

That looks like a clear low frequency/seasonal scale poleward propagation to me. You should be able to filter for it quite easily (if it’s not already obvious to the naked eye).

 

Poleward propagation from 20N to 30N over a span of 2 months is not poleward propagation attributable mostly to subseasonal variability like you previously claimed because the momentum isn't being transferred from the deep tropics into the extratropics on the timescales of the subseasonal phenomena.

 

Subseasonal forcing acting in concert w/ and being manipulated by ENSO may have triggered the initial anomaly but it's very obvious that there's something maintaining the momentum in the subtropics over the course of multiple subseasonal waves. The same thing happened in late 1997 but the +AAM in the subtropics from October-December certainly wasn't due to subseasonal forcing or even propagating poleward significantly and looks relatively similar to what's happening now in terms of overall structure & juxtaposition.

[Guest daniel1]

You also mean your "interpretation" about this event peaking now? Or how about this head fake into an El Nino? We all know how the latter panned out...

 

Yep, there's a trade wind burst east of the dateline in the coming week but WWBs will return as the forcing enters the western hemisphere, you conveniently left out that last part.

 

 

 

Remote wind stress forcing of SSTs is stronger than local wind forcing east of the dateline, those WWBs near the edge of the warmpool will trigger a Kelvin Wave response & it'll be interesting to see how that's realized in the grand scheme of things

Will these WWBs help to create a more modoki like look?

[Phil]

You also mean your "interpretation" about this event peaking now? Or how about this head fake into an El Nino? We all know how the latter panned out..

Yeah..I think it has peaked. You don’t? IIRC, you were really pimping out those 1.5C SSTAs in region 3.4 just a few weeks ago arguing it was some kind of step change upwards

 

Now they’re below niño threshold completely.

 

Yep, there's a trade wind burst east of the dateline in the coming week but WWBs will return as the forcing enters the western hemisphere, you conveniently left out that last part.

 

 

Remote wind stress forcing of SSTs is stronger than local wind forcing east of the dateline, those WWBs near the edge of the warmpool will trigger a Kelvin Wave response & it'll be interesting to see how that's realized in the grand scheme of things

I cannot see that image. But the relatively intense convection across the WHEM/Africa/E-IO domain has destructively interfered with the WPAC/warm pool component, which has stunted the OKW activity and hence the development of the niño. So unless that changes, getting legitimate OKW activity will be challenging.

[Phil]

Poleward propagation from 20N to 30N over a span of 2 months is not poleward propagation attributable mostly to subseasonal variability like you previously claimed because the momentum isn't being transferred from the deep tropics into the extratropics on the timescales of the subseasonal phenomena.

Did I say it was “subseasonal”? I said there are subseasonal expressions in the anomalies (IE: rate of displacement via eddy transports is modulated by subseasonal-peripheral forcings) but there are a slew of time spectra in the manifestation of these anomalies as well. In fact, the boundary between seasonal and subseasonal itself is not well defined. The propagation in this case sits in-between the typical seasonal/subseasonal boundaries.

 

Subseasonal forcing acting in concert w/ and being manipulated by ENSO may have triggered the initial anomaly but it's very obvious that there's something maintaining the momentum in the subtropics over the course of multiple subseasonal waves. The same thing happened in late 1997 but the +AAM in the subtropics from October-December certainly wasn't due to subseasonal forcing or even propagating poleward significantly and looks relatively similar to what's happening now in terms of overall structure & juxtaposition.

Again, I’ve never denied the +AAM integral in the region is a +ENSO expression. So I’m not sure why you’re still trying to convince me of it.

[Webberweather53]

Yeah..I think it has peaked. You don’t? IIRC, you were really pimping out those 1.5C SSTAs in region 3.4 just a few weeks ago arguing it was some kind of step change upwards

 

Now they’re below niño threshold completely.

 

 

I cannot see that image. But the relatively intense convection across the WHEM/Africa/E-IO domain has destructively interfered with the WPAC/warm pool component, which has stunted the OKW activity and hence the development of the niño. So unless that changes, getting legitimate OKW activity will be challenging.

 

Yeah, like I said there's a huge WWB coming and the EPS forecast has become way more aggressive the past few days. Like I said, good luck predicting an easterly trade burst on the horizon.

 

http://blog.southernwx.com/wp-content/uploads/2018/11/iF38OJ3y-1024x768.jpg

[Webberweather53]

Yeah, like I said there's a huge WWB coming and the EPS forecast has become way more aggressive the past few days.

 

http://blog.southernwx.com/wp-content/uploads/2018/11/iF38OJ3y-1024x768.jpg

 

 

This was the forecast just 3 days ago. Comparing w/ today, it's very obvious the EPS is adjusting towards a larger, stronger, & longer-lived WWB...

http://blog.southernwx.com/wp-content/uploads/2018/11/18nJ1YLy-1-1024x784.jpg

[Guest daniel1]

What would this mean besides giving a boost to El Niño? Warmer water in 3.4?

[Webberweather53]

What would this mean besides giving a boost to El Niño? Warmer water in 3.4?

 

A WWB of that magnitude would definitely trigger another downwelling Kelvin Wave, keep in mind there's increasing spread w/ time and the actual signal on the EPS is actually likely to be dampened vs reality. 

[Guest daniel1]

A WWB of that magnitude would definitely trigger another downwelling Kelvin Wave, keep in mind there's increasing spread w/ time and the actual signal on the EPS is actually likely to be dampened vs reality.

I saw that you just tweeted about it. What would a downwelling KW cause? More warming in 3.4 region and central based El Niño? So you’re thinking the WWB won’t be that strong?

 

Sorry for the all the questions I’m just learning all this stuff.

[Webberweather53]

I saw that you just tweeted about it. What would a downwelling KW cause? More warming in 3.4 region and central based El Niño? So you’re thinking the WWB won’t be that strong?

 

Sorry for the all the questions I’m just learning all this stuff.

 

The EPS a few days ago had a modest WWB and is rapidly adjusting to a bigger one w/ time, the EPS has a well known wet bias in the Maritime Continent (thus too strong trades in the Pacific) and it's rearing its ugly head yet again here. There's already a downwelling Kelvin Wave in the east-central Pacific so there would be an initial burst of warming in the first week or two and assuming the WWB is anywhere near this strong (or stronger), the Kelvin Wave would warm the water yet again in 2-3 months or so because that's how long it takes for a Kelvin Wave to cross the Pacific!

[Guest daniel1]

The EPS a few days ago had a modest WWB and is rapidly adjusting to a bigger one w/ time, the EPS has a well known wet bias in the Maritime Continent (thus too strong trades in the Pacific) and it's rearing its ugly head yet again here. There's already a downwelling Kelvin Wave in the east-central Pacific so there would be an initial burst of warming in the first week or two and assuming the WWB is anywhere near this strong (or stronger), the Kelvin Wave would warm the water yet again in 2-3 months or so because that's how long it takes for a Kelvin Wave to cross the Pacific!

Thanks for the prompt responses.

 

So basically you’re saying region 3.4 and 4 will warm further? Also I’ve seen some warmer water surface in region 1.2 and 3. Is this temporary? Are we still looking at this El Niño being central based?.

[Webberweather53]

Thanks for the prompt responses.

 

So basically you’re saying region 3.4 and 4 will warm further? Also I’ve seen some warmer water surface in region 1.2 and 3. Is this temporary? Are we still looking at this El Niño being central based?.

 

Absolutely! Yes I'm saying if this forecast is anywhere close to panning out (or god forbid we continue trending towards a larger WWB), then there's potential for them to warm further in the long run. The warming in the some of the regions was temporary in response to the last WWB plus a Kelvin Wave moving thru the east-central Pacific but a WWB of this size could push us right back to the values we saw just a few weeks ago. As far as this NINO being central based it's fairly complicated and could become one of those rare cases of a NINO intensifying potentially thru the winter solstice which rarely occurs and during the intensification/building phase NINOs are more east-based and become more modoki as they age. Weaker El Ninos are more likely to be modoki/central Pacific El Ninos and there's a long-term trend at least in the last 40 years or so towards more frequent central pacific NINOs. The positive north Pacific Meridional Mode coupled to a negative south pacific meridional mode is typically an indicator/precursor to modoki El Nino. In short, there are more factors going for this being a central based event and that's most likely imo but it's not entirely out of the question this becomes an EP NINO in due time although I don't consider that likely for now anyways.

[TigerWoodsLibido]

Absolutely! Yes I'm saying if this forecast is anywhere close to panning out (or god forbid we continue trending towards a larger WWB), then there's potential for them to warm further in the long run. The warming in the some of the regions was temporary in response to the last WWB plus a Kelvin Wave moving thru the east-central Pacific but a WWB of this size could push us right back to the values we saw just a few weeks ago. As far as this NINO being central based it's fairly complicated and could become one of those rare cases of a NINO intensifying potentially thru the winter solstice which rarely occurs and during the intensification/building phase NINOs are more east-based and become more modoki as they age. Weaker El Ninos are more likely to be modoki/central Pacific El Ninos and there's a long-term trend at least in the last 40 years or so towards more frequent central pacific NINOs. The positive north Pacific Meridional Mode coupled to a negative south pacific meridional mode is typically an indicator/precursor to modoki El Nino. In short, there are more factors going for this being a central based event and that's most likely imo but it's not entirely out of the question this becomes an EP NINO in due time although I don't consider that likely for now anyways.

Depressing

[Guest daniel1]

Absolutely! Yes I'm saying if this forecast is anywhere close to panning out (or god forbid we continue trending towards a larger WWB), then there's potential for them to warm further in the long run. The warming in the some of the regions was temporary in response to the last WWB plus a Kelvin Wave moving thru the east-central Pacific but a WWB of this size could push us right back to the values we saw just a few weeks ago. As far as this NINO being central based it's fairly complicated and could become one of those rare cases of a NINO intensifying potentially thru the winter solstice which rarely occurs and during the intensification/building phase NINOs are more east-based and become more modoki as they age. Weaker El Ninos are more likely to be modoki/central Pacific El Ninos and there's a long-term trend at least in the last 40 years or so towards more frequent central pacific NINOs. The positive north Pacific Meridional Mode coupled to a negative south pacific meridional mode is typically an indicator/precursor to modoki El Nino. In short, there are more factors going for this being a central based event and that's most likely imo but it's not entirely out of the question this becomes an EP NINO in due time although I don't consider that likely for now anyways.

When do you think this Niño reaches it peak?