2012 ENSO Thread

[GaWx]

Folks,

It still looks like the +20's are coming. Actually, I'm estimating +20's the next two days. Afterward, it should slowly drop, but not get negative until all the way around 7/21. By that time, the SOI MTD could easily average

near +6 before falling back to negatives. That means July as a whole will have a decent shot at a positive SOI. In the bigger picture, that means that

there will likely be no sig. Niño 3.4 warming and that it could even cool back some for a few weeks. That would mean an increased chance for a fall/winter WEAK Nino peak vs. MODERATE vs. how it may have appeared, say, two or so weeks ago. Also, there is a partial positive correlation between July-Aug SOI and peak season MDR Atlantic tropical activity. So, perhaps this will help reawaken the Atlantic tropics by early August. We'll see.

Well, there were no +20's after all due to a slightly lower than projected Tahiti SLP. However, it did still get up to +18 (the highest SOI since 5/10) and +16. So, there still were pretty solid positives. Looking ahead, it still looks pretty similar to how it looked in my previous post with no more -SOI's likely until ~7/20. Then, it appears there will be likely some -SOI's for at least a few days afterward. In the meantime, the month to date SOI has risen to ~+1.5 and should rise to near +5 by 7/19. The question will then be whether or not the returning negatives will be enough to get it back down to a -SOI month to date. That will be a bit of a challenge. A +SOI for July is fairly rare when preceding a moderate to strong El Nino. However, it has done just that a few times including in 2009. Nevertheless, a +SOI for July '12 and other data would tell me that the odds for a weak Nino vs. moderate (based on the ONI related definitions) would be somewhat over 50%. Also, there is a partial correlation of ATL MDR tropical activity in the heart of the season and the July-Aug SOI's. So, if this not so negative SOI (say no lower than ~-5) were to go into, say, mid-August, I'd think that this more positive SOI would help increase the MDR's chances somewhat for a not so dead season. We'll see.

[carley5]

i see the SOI has made it to +20.5.

[GaWx]

Per models, I'm projecting the +SOI string to finally be broken tomorrow, with modest -'s on 7/22-3. 7/24 should rise back to near neutral followed by fairly modest +'s 7/25-7. Then expect

-'s for 7/28-31, with some strong negatives (maybe sub -30 one or two days). This means that the 30 day would rise to ~-2 on 7/24 and near 0 on 7/25. The 30 day would then go to ~+2 on 7/26 and ~+3 for 7/27-8. Then it would fall back toward 0. I'm projecting July as a whole to end up in the 0 to +1 range.

[Ed Lizard]

Not an ENSO heavy, but wondering if the smarter guys like GaWx, Don or the red tags have an opinion how long the warm ENSO will last. Whether it affects 2013 hurricane season.

2009 warm ENSO had a silver lining, early December snowfall in Houston, some places near the city exceeding an inch! So I can find the bright side of a warm ENSO. I'd still like a 2013 hurricane season, however.

[GaWx]

Not an ENSO heavy, but wondering if the smarter guys like GaWx, Don or the red tags have an opinion how long the warm ENSO will last. Whether it affects 2013 hurricane season.

2009 warm ENSO had a silver lining, early December snowfall in Houston, some places near the city exceeding an inch! So I can find the bright side of a warm ENSO. I'd still like a 2013 hurricane season, however.

1) 13 of the last 16 first year El Nino's weren't followed by a 2nd year El Nino. So, there's a very good chance it won't go into a 2nd year. So, I'm 13/16 glass full.

2) I'm projecting the current one to most likely end up being weak at peak. If so, there's a decent shot as some halfway decent MDR activity around the peak. With the July SOI ending near 0, that is somewhat encouraging vs. if it has been something like -10. If the Aug. SOI could remain no more negative than -5 or so, the prospects would appear to improve further based on history due to the partial positive correlation between the July-Aug SOI and the MDR activity in Aug-Sep. So, I'm probably about 50% glass full on at least halfway decent MDR activity this season as of now. The next few weeks of SOI's will be quite telling.

[Ed Lizard]

1) 13 of the last 16 first year El Nino's weren't followed by a 2nd year El Nino. So, there's a very good chance it won't go into a 2nd year. So, I'm 13/16 glass full.

2) I'm projecting the current one to most likely end up being weak at peak. If so, there's a decent shot as some halfway decent MDR activity around the peak. With the July SOI ending near 0, that is somewhat encouraging vs. if it has been something like -10. If the Aug. SOI could remain no more negative than -5 or so, the prospects would appear to improve further based on history due to the partial positive correlation between the July-Aug SOI and the MDR activity in Aug-Sep. So, I'm probably about 50% glass full on at least halfway decent MDR activity this season as of now. The next few weeks of SOI's will be quite telling.

Thanks.

[griteater]

Weekly NINO 3.4 SST anomaly on the Aussie site is up to +0.68 as of Jul 22.

[carley5]

SOI has gone positive for the 30 day average now. +1.3

[wxmx]

Step backward was rather large. El Niño development has lost some of it's punch, and it seems that in the short term there will be little change in the SSTAs along most ENSO regions...maybe some slow warming ahead, with no sight of any significant WWBs next 1-2 weeks.

Slow warming, no WWBs, last 2 weeks. Step back next 1-2 weeks, some slight cooling is possible with weak to mod easterly anomalies for most of the ENSO regions.

[kylemacr]

We currently have the easterly phase of the MJO (red contours) making its way around, with the westerly phase not far behind. However, it does look like WWBs will be minimal, judging by the amplitude of that westerly phase forecast by the CFS. (Note that the dotted lines are the westerlies and the solid lines are the easterlies.)

So, yes, this is bad for the short-term... we might get some slight cooling, but I think we need to look at the bigger picture - a few days/weeks of slight cooling is nothing but noise on the ENSO timescale. I would still argue that we are on the way to a pretty solid (though, perhaps not exceptionally strong) El Niño for the Fall/Winter.

One thing that keeps me hopeful for the near future is the forecast for fairly strong low-frequency westerlies that the CFS seems to want to forecast for the middle of August. I've posted the zonal wind hovmoller here, but you can see the OLR hovmoller here: http://www.atmos.alb....php?lat=75S75N . The two are consistent with each other. Normally, I wouldn't trust a model out 30-days under any circumstances. But, since this forecast has isolated the low-frequency component, there is some hope. The 30-day forecast from the CFS for low-frequency convection has an ACC of about 90%. That's pretty impressive, but it is consistent with the idea that low-frequency patterns are more predictable than higher-frequency patterns.

[carley5]

so, in english does that give hope for an exciting aug/sept tropical wise?

[wxmx]

We currently have the easterly phase of the MJO (red contours) making its way around, with the westerly phase not far behind. However, it does look like WWBs will be minimal, judging by the amplitude of that westerly phase forecast by the CFS. (Note that the dotted lines are the westerlies and the solid lines are the easterlies.)

So, yes, this is bad for the short-term... we might get some slight cooling, but I think we need to look at the bigger picture - a few days/weeks of slight cooling is nothing but noise on the ENSO timescale. I would still argue that we are on the way to a pretty solid (though, perhaps not exceptionally strong) El Niño for the Fall/Winter.

One thing that keeps me hopeful for the near future is the forecast for fairly strong low-frequency westerlies that the CFS seems to want to forecast for the middle of August. I've posted the zonal wind hovmoller here, but you can see the OLR hovmoller here: http://www.atmos.alb....php?lat=75S75N . The two are consistent with each other. Normally, I wouldn't trust a model out 30-days under any circumstances. But, since this forecast has isolated the low-frequency component, there is some hope. The 30-day forecast from the CFS for low-frequency convection has an ACC of about 90%. That's pretty impressive, but it is consistent with the idea that low-frequency patterns are more predictable than higher-frequency patterns.

Great post and I'm with you about short term and noise and ENSO and the possibility of seeing a solid Niño (thinking of a weak Niño myself) for the winter. I think short/medium term (less than a month) are still somewhat useful for the tropics evolution, and your post nearly confirms my current line of thinking that we won't see any strong evolution of the ENSO until fall, so a good portion of the Atlantic tropical season could see near average shear profiles (maybe even slightly below average, as the tropical forcing remains west of the dateline, with the dateline still experiencing some +OLR anomalies), with the probable exception of October as the Niño might begin to gain some steam at the time.

[GaWx]

Per models, I'm projecting the +SOI string to finally be broken tomorrow, with modest -'s on 7/22-3. 7/24 should rise back to near neutral followed by fairly modest +'s 7/25-7. Then expect

-'s for 7/28-31, with some strong negatives (maybe sub -30 one or two days). This means that the 30 day would rise to ~-2 on 7/24 and near 0 on 7/25. The 30 day would then go to ~+2 on 7/26 and ~+3 for 7/27-8. Then it would fall back toward 0. I'm projecting July as a whole to end up in the 0 to +1 range.

The above worked out well although 7/25-7 were all small -'s instead of modest +'s. July ended up being +0.1.

Here is my interpretation of today's 0Z Euro based projections in terms of daily SOI's:

8/1-10: -32, -22, -3, +8, +20, +17, +4, -8, -25, -30 (Edit: the dailes soon after would likely be less negative than -30.)

This would make the 8/1-10 averaged SOI be near -7, which is a bit more El Ninoish start to August vs. July's near 0.

[griteater]

Last 6 days of SOI have been double-digit negative, with -36 and -33 for Aug 1 and 2. Slight increase in weekly negative OLR anomalies east of the dateline over last few weeks. 850 zonal wind anomalies in the Nino regions look fairly neutral in the 7 day forecast.

[uncle W]

June/July mei index is 1.139...well into el nino territory...It's the fifth highest J/J index of all the developing nino years...

1997...+2.756

1972...+1.886

1982...+1.620

1965...+1.395

2012...+1.139

....................................

[SoCoWx]

June/July mei index is 1.139...well into el nino territory...It's the fifth highest J/J index of all the developing nino years...

1997...+2.756

1972...+1.886

1982...+1.620

1965...+1.395

2012...+1.139

....................................

So...yeah..is that good or bad in any way?

[SoCoWx]

Bump.

[GaWx]

The above worked out well although 7/25-7 were all small -'s instead of modest +'s. July ended up being +0.1.

Here is my interpretation of today's 0Z Euro based projections in terms of daily SOI's:

8/1-10: -32, -22, -3, +8, +20, +17, +4, -8, -25, -30 (Edit: the dailes soon after would likely be less negative than -30.)

This would make the 8/1-10 averaged SOI be near -7, which is a bit more El Ninoish start to August vs. July's near 0.

I didn't do as well as I did in late July. I missed in the positive direction 8/1-8 and in the negative direction 8/9-10. The actual MTD avg. SOI is ~-12.5 vs. my projection of -7...i.e., even more El Ninoish than I had thought.

Looking ahead, I see -'s continuing through 8/15, near neutral on 8/16, and +'s for 8/17-20. August as a whole is looking to be solidly negative, but it is stil too early to call that with high confidence.

[wxmx]

Significant setback for El Niño is incoming. Strongest easterly push since spring is forecasted. Looks like hurricane season won't be affected much.

[ORH_wxman]

Significant setback for El Niño is incoming. Strongest easterly push since spring is forecasted. Looks like hurricane season won't be affected much.

I love those cross-sections...where do you get them? I used to have a link for them a couple years ago, but no longer have it on my new comp.

[wxmx]

I love those cross-sections...where do you get them? I used to have a link for them a couple years ago, but no longer have it on my new comp.

From Carl Schreck's website. That image is a hotlink, you can find it here

http://www.atmos.alb...weather/timeLon

and his website is here:

http://www.atmos.alb...ther/index.html

and here:

http://monitor.cicsnc.org/mjo/current/

[GaWx]

I didn't do as well as I did in late July. I missed in the positive direction 8/1-8 and in the negative direction 8/9-10. The actual MTD avg. SOI is ~-12.5 vs. my projection of -7...i.e., even more El Ninoish than I had thought.

Looking ahead, I see -'s continuing through 8/15, near neutral on 8/16, and +'s for 8/17-20. August as a whole is looking to be solidly negative, but it is stil too early to call that with high confidence.

1) Evaluation of 8/11-20:

I didn't get as specific this time as I focused on sign without magnitude. Well, we had -SOI's 8/11-16. So, they hung on a day longer than I projected. 8/17-19 had +SOI's as expected, but 8/20 unexpectedly turned back negative.

Through 8/21, the August MTD SOI is a little under -12, which is a solid -PDO.

2) Forecast to end of month: positives

I'm leaning to 8/22 going back to slightly positive. After this, I have +SOI's through the end of the month. As a result, I'm projecting the current MTD SOI of sub -12 to modify considerably and bring August 2012 up to ~-6, which isn't inconsistent with a later weak Nino peak (ONIwise) in fall/winter.

[GaWx]

1) SOI:

SOI patterns of last few months overall have been somewhat back and forth and have averaged only modestly negative. I've found the SOI to be a good tool to help foretell ultimate Nino/Nina peak strength. Only June 2012 has had a moderate negative average. Aug., which is now ~-12 MTD, will rise pretty dramatically to ~~-6 for August as a whole based on my expectations of positive SOI's the rest of the month as per my interpretation of model projections' at the surface. Granted, 2009's monthly SOI's were even more modest through Sep. Admittedly, that Nino didn't follow historical patterns with its SOI. OTOH, 2002 and 2006 were more negative through August. I have even 2004 as slightly more negative than 2012 to this point.

2) OHC:

My rough estimate when looking at recent subsurface movies as well as OHC graphs and when considering the last weekly update tells me that the OHC anom. is only very slowly rising and remains below +1.0 C (maybe near +0.85. I'll continue to watch OHC very closely for future monthly SST anomaly hints). As long as the monthy OHC's don't ever get above, say, ~+1.25, a weak Nino peak would still be very much in play.

Subsurface movie: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/anim/wkxzteq_anm.gif

OHC monthlies: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

Weekly ENSO update: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

3) OLR:

It looks as if August may come in with a +OLR. If not a +OLR, it should only be very modestly negative. Looking at the OLR graph, it is clearly positive MTD...maybe ~+5 or so although dropping back now due to the current and recent days' -OLR's. There is a pretty strong negative correlation between August OLR and upcoming ENSO peak. Let's look at past (pre)Nino August OLR's going back to 1976 (2009 N/A unfortunately):

-8.2, +0.9, -24.2, +4.4, -23.3, -14.6, -7.9, -24.3, -23.2, -4.5, -6.2; AVG = -11

To be fair, 2009, which didn't seem to follow past patterns based on various measures, very likely had a +OLR in August per the graph. Otherwise, only 1977 and 1986 had a +OLR in August. 1977 was weak while 1986, another somewhat strange one relative to certain measures, was moderate. Let's see how August 2012 actually finishes.

OLR graph: http://cawcr.gov.au/staff/mwheeler/maproom/OLR/ts.r4.l.gif

Monthly OLR table: http://www.cpc.ncep.noaa.gov/data/indices/olr

4) -PDO:

The current solid -PDO regime still tends to favor weaker Nino's somewhat at the expense of stronger ones, despite the unusual behavior of 2009 in relation to its respective summer SOI and August OLR.

5) Dynamic ENSO Models:

Last, but certainly not least, the mid-August DYNAMIC Nino 3.4 projection model avg. is slightly favoring an ONI in the weak category with its avg. peak of ~+1.0 C.

Conclusion: I continue to think a weak peak (ONI max anomaly no higher than +1.0 C) is most likely with low end moderate (+1.1 to +1.2 C ONI peak anomaly) second most likely.

[wxmx]

Significant setback for El Niño is incoming. Strongest easterly push since spring is forecasted. Looks like hurricane season won't be affected much.

In the short term we'll see no significant change in the ENSO.

According to the CFS, there'll be a building battle between a building WWB just west of the date line and easterly anomalies for the rest of the equatorial pacific, with a significant MJO wave giving the final push of the westerly anomalies through the C/E Pac by late October.

Graph taken from Kyle MacRitchie's website

[GaWx]

1) Evaluation of 8/11-20:

I didn't get as specific this time as I focused on sign without magnitude. Well, we had -SOI's 8/11-16. So, they hung on a day longer than I projected. 8/17-19 had +SOI's as expected, but 8/20 unexpectedly turned back negative.

Through 8/21, the August MTD SOI is a little under -12, which is a solid -SOI.

2) Forecast to end of month: positives

I'm leaning to 8/22 going back to slightly positive. After this, I have +SOI's through the end of the month. As a result, I'm projecting the current MTD SOI of sub -12 to modify considerably and bring August 2012 up to ~-6, which isn't inconsistent with a later weak Nino peak (ONIwise) in fall/winter.

1) Evaluation of 8/22-31:

I did well. 8/22-31 all had +'s except that there was a small - on 8/29. August 2012 ended up being

-6.2 vs. my guess of ~-6. A -6 in August is pretty consistent with a weak Nino peak in fall/winter as opposed to a stronger one.

2) SOI Forecast for 9/1-10: pretty undramatic, which certainly doesn't support a moderate or stronger El Nino:

9/1: near 0

9/2-4: small -'s

9/5-10: small +'s peaking on 9/6-7 (maybe as high as low teens at peak)

[uncle W]

June/July mei index is 1.139...well into el nino territory...It's the fifth highest J/J index of all the developing nino years...

1997...+2.756

1972...+1.886

1982...+1.620

1965...+1.395

2012...+1.139

....................................

July August MEI came in at +0.579...That is the greatest reversal for a developing El Nino on record for this time of year...The oni came in at 0.1... 0.1 rise from the last reading......

[GaWx]

July August MEI came in at +0.579...That is the greatest reversal for a developing El Nino on record for this time of year...The oni came in at 0.1... 0.1 rise from the last reading......

That ONI of only +0.1 looks very suspect to me. It should have come in near +0.5. I don't know the reason for this. The weeklies suggest near +0.5. I've never seen the weeklies and ONI anywhere near this far off. Actually, the last two ONI's look too low. AMJ and earlier look fine to me.

[aljareer]

hi

The Quasi-biennial Oscillation in jul and aug and sep 2012 : East Phase .

QBO East : Deep Easterlies , Min Storm in Atlantic .

[aljareer]

Quasi-Biennial Oscillation (QBO) in Stratospheric Zonal Winds and Interannual Atlantic Hurricane Activity . by Gray 1984

[aljareer]

QBO . By : IRI :

http://iridl.ldeo.columbia.edu/maproom/.Global/.Atm_Circulation/QBO.html