ENSO Updates (2007 thru 2023)

[Ntxw]

Since we're "Talkin Tropics", I was curious if anyone actually knew what the lowest daily SOI plunge on record is? I've seen the low 30's in the last month, but I was wanting to see what the lowest plunge ever was

There was a -85+ SOI in 1997 at some point for daily

1997 151 1006.08 1015.75 -85.72

Today's SOI held steady. Tahiti did fall once again to 1012.90 but Darwin fell a little as well to 1014.90 giving us -21.97. 30 day has once again fallen beyond -10.

[NDG]

Since we're "Talkin Tropics", I was curious if anyone actually knew what the lowest daily SOI plunge on record is? I've seen the low 30's in the last month, but I was wanting to see what the lowest plunge ever was

There was a -85+ SOI in 1997 at some point for daily

1997 151 1006.08 1015.75 -85.72

Today's SOI held steady. Tahiti did fall once again to 1012.90 but Darwin fell a little as well to 1014.90 giving us -21.97. 30 day has once again fallen beyond -10.

I knew the GFS was not going to let me down

Code: Select all

Date        Tahiti  Darwin  Daily** 30 day avg SOI 90 day avg SOI
17 Aug 2012 1015.26 1013.15  2.97     -10.90         -7.89

[Ntxw]

^ Indeed it rose dramatically today and SOI went from very negative to positive good call.

SST's probably cooled a bit as well which might reflect Monday's update, or it might hold steady a little hard to tell with warm water shifting around. The MJO is heading into unfavorable territory for dramatic warming and as result may allow some tropical activity to flare in the Atlantic basin.

[dexterlabio]

With all these delay I think warm neutral will persist until September. Daily SOI now up to 10.38, though I think this is just a temporary swing and the 30-day is trending all the way down.. Maybe this year will be like 2006 weak El Nino.

[jinftl]

We are approaching late August and entering the peak of the season...based on the discussion below by Dr. Masters, i think it is becoming clear we have entered the peak of this season without the effect of el nino to decrease hurricane activity by increasing shear. Perhaps by later in September or October, but by then the season starts to wane except for the Western Caribbean-Florida threat for the most part. We are on pace for a top 2 or 3 season in terms of # of storms....things would have to hit the brakes big time for us not to have 15+ named storms. We are 3 weeks away from the peak mid-point and we are at 8 storms, and probably will hit #9 in the next few days.

El Niño watch continues
Sea surface temperatures increased to 0.8°C above average as of August 13 in the equatorial Pacific off the coast of South America. Ocean temperatures have been near or above the 0.5°C above average threshold needed for a weak El Niño event since the beginning of July. However, winds, pressures, and cloud cover over the region have not responded in the fashion typically associated with an El Niño, and NOAA's Climate Prediction Center (CPC) said that "The lack of a clear atmospheric response to the positive oceanic anomalies indicates ongoing ENSO-neutral conditions," in their August 9 El Niño discussion. They have issued an El Niño watch, and give a 71% chance that an El Niño event will be in place by September. El Niño conditions tend to decrease Atlantic hurricane activity, by increasing wind shear over the tropical Atlantic. Wind shear has been close to average over the tropical Atlantic since the beginning of hurricane season in June, though.
http://www.wunderground.com/blog/JeffMa ... rynum=2192

[Ntxw]

I am no expert as Dr Masters, nor do I have any confidence in my thinking regarding connections to ENSO and tropical season. But in this case just based on conditions in the Pacific as is I have to disagree with him about the winds, pressure, and cloud cover over the tropical Pacific not responding. MEI is our only true value in measuring all these elements and it says they have responded to the warmer anomalies regarding those parameters. There has been constant convection in equatorial Pacific so I don't know why one would say "lack of cloud cover and pressure" as evident.

[Ntxw]

Enso cooled as the kelvin/mjo left the region late last week, could even be by a good margin. I was off by a week in thinking the mjo would remain there a bit longer but didn't and the dramatic warming was last week not this week.

[cycloneye]

Enso cooled as the kelvin/mjo left the region late last week, could even be by a good margin. I was off by a week in thinking the mjo would remain there a bit longer but didn't and the dramatic warming was last week not this week.

There is the cooling. The CPC update will be up after 10:00 AM EDT.

[cycloneye]

Climate Prediction Center 8/20/12 Update

It cooled a little bit at Nino 3.4 (+0.6C) down from +0.8C that was last week.

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[Ntxw]

With the cooling today it still has remained above 0.5c. Nino 3.4 anomalies have been in place (0.5c or greater) since June 27th (except for one week in July when it was 0.4c). In general the weeklies have been close to 2009. That year late Sept saw a cooling of ENSO and the first 1.0c or greater came in late Oct. Will this year's Nino follow that trend or do something different?

Source: http://www.cpc.ncep.noaa.gov/data/indices/wksst8110.for

[LarryWx]

With the cooling today it still has remained above 0.5c. Nino 3.4 anomalies have been in place (0.5c or greater) since June 27th (except for one week in July when it was 0.4c). In general the weeklies have been close to 2009. That year late Sept saw a cooling of ENSO and the first 1.0c or greater came in late Oct. Will this year's Nino follow that trend or do something different?

Source: http://www.cpc.ncep.noaa.gov/data/indices/wksst8110.for

I'm confident that the current Nino will not be as strong as 2009-10. I'm thinking weak Nino is the most likely fall/winter peak (no warmer than +1.0 C in Nino 3.4 over any three month period...i.e., +1.0 C or cooler for warmest ONI).

[Ntxw]

I'm confident that the current Nino will not be as strong as 2009-10. I'm thinking weak Nino is the most likely fall/winter peak (no warmer than +1.0 C in Nino 3.4 over any three month period...i.e., +1.0 C or cooler for warmest ONI).

What makes you think this? I've been contemplating on how strong this Nino should be but haven't found any reliable correlation. At first I thought a cold PDO would guarantee a weak nino but looking at the PDO indices every Nino in the cold PDO have had a spike to warm values during it's existence but even low spikes like 1972-1973 there was a strong Nino vs a moderate Nino in a higher spike in 2002-2003. JJ MEI was quite higher than I expected nearly moderate territory and July/August will surely be higher. Is this a short term thing? Curious to see your thoughts!

PDO

http://jisao.washington.edu/pdo/PDO.latest

[LarryWx]

I'm confident that the current Nino will not be as strong as 2009-10. I'm thinking weak Nino is the most likely fall/winter peak (no warmer than +1.0 C in Nino 3.4 over any three month period...i.e., +1.0 C or cooler for warmest ONI).

What makes you think this? I've been contemplating on how strong this Nino should be but haven't found any reliable correlation. At first I thought a cold PDO would guarantee a weak nino but looking at the PDO indices every Nino in the cold PDO have had a spike to warm values during it's existence but even low spikes like 1972-1973 there was a strong Nino vs a moderate Nino in a higher spike in 2002-2003. JJ MEI was quite higher than I expected nearly moderate territory and July/August will surely be higher. Is this a short term thing? Curious to see your thoughts!

PDO
http://jisao.washington.edu/pdo/PDO.latest

1) SOI:

SOI patterns of last few months have been pretty 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 had a moderate negative avgerage. Aug., which is now ~-12 MTD, will rise pretty dramatically to ~~-6 for the month 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 SOIwise 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 tell 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/a ... eq_anm.gif

OHC monthlies: http://www.cpc.ncep.noaa.gov/products/a ... _index.txt

Weekly ENSO update: http://www.cpc.ncep.noaa.gov/products/a ... ts-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. As you may know, there is a pretty strong negative correlation between August OLR and upcoming ENSO SST 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 was moderate. 1986 was another somewhat strange Nino in that it seemed '"off" when looking at various underlying measures. Let's see how August 2012 actually finishes.

OLR graph: http://cawcr.gov.au/staff/mwheeler/mapr ... s.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 as you know, 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.

[cycloneye]

Here are the Mid-August updated model forecasts.

[Ntxw]

Very interesting thoughts LarryWx. Thanks for the input. I like to follow the Euro which is showing low end Moderate since I've had a better experience with it. We'll have to see how things play out. One note is that central based are effected by Kelvin wave warming and influenced by weather patterns more than EP Nino's. This will be a fascinating aspect to it's evolution in the coming months.

[SoupBone]

I'm confident that the current Nino will not be as strong as 2009-10. I'm thinking weak Nino is the most likely fall/winter peak (no warmer than +1.0 C in Nino 3.4 over any three month period...i.e., +1.0 C or cooler for warmest ONI).

What makes you think this? I've been contemplating on how strong this Nino should be but haven't found any reliable correlation. At first I thought a cold PDO would guarantee a weak nino but looking at the PDO indices every Nino in the cold PDO have had a spike to warm values during it's existence but even low spikes like 1972-1973 there was a strong Nino vs a moderate Nino in a higher spike in 2002-2003. JJ MEI was quite higher than I expected nearly moderate territory and July/August will surely be higher. Is this a short term thing? Curious to see your thoughts!

PDO
http://jisao.washington.edu/pdo/PDO.latest

1) SOI:

SOI patterns of last few months have been pretty 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 had a moderate negative avgerage. Aug., which is now ~-12 MTD, will rise pretty dramatically to ~~-6 for the month 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 SOIwise than 2012 to this point.

Can you further clarify this thought? So far, 16 out of 21 days have been negative with the negative average over those days at -17.54. Just curious.

[LarryWx]

Aug., which is now ~-12 MTD, will rise pretty dramatically to ~~-6 for the month 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.

Can you further clarify this thought? So far, 16 out of 21 days have been negative with the negative average over those days at -17.54. Just curious.

Based on the Euro's southern hemispheric surface pressure forecast maps out 10 days, I'm saying (based on my interpretation) that the projection is for +SOI's based on the SOI formula, which involves SLP at both Darwin and Tahiti.

[Ntxw]

Nino 3.4 cooled this week but the past several days has seen a slight rebound. It's quite possible we might see another drop in tomorrow's update. The big difference will be 1+2 as it's seen some dramatic warming lately.

[Ntxw]

Well it looks like I was wrong to say it might cool, it leveled off this week and stayed at 0.6c. 1+2 warmed.

MJO is stubborn sticking into phase 3 per Australian MJO update. Perhaps the Atlantic basin will remain active for a little longer into first week of Sept.

[rainstorm]

SOI continues to be positive. maybe the el nino has peaked.