ENSO Updates (2007 thru 2023)

[Ntxw]

Lets see if I can put together some info to clarify a Modoki (central) from an EP (traditional) El Nino.

Modoki: Generally central based El Nino where warmest waters are nearer to the international dateline Nino 3.4 and is usually accompanied by cooler waters off SA (not always)


EP (eastern pacific) traditional: Warm throughout with greatest warming in Nino 3 and 1+2


Now you might be asking why I posted 2009's El Nino under Modoki. In fact it was a Modoki, the strongest of the bunch. Why? Modoki in it's simplest terms states that the warmest waters reside in Nino 3.4 and cooler elsewhere.

1986, 1991-1992, 1994-1995, 2002-2003, 2004-2005, and 2009-2010 were all Modoki. 2006-2007 was iffy but some consider it a possibility.

EP traditional El Nino 1982-1983 and 1997-1998

Taking this data we see that for the past 20+ years (since satellite data was available) we see that Modoki Nino's are not as uncommon, one could argue otherwise that traditional Nino's are rarer and often the strongest.

How this correlates to tropical season? There isn't enough satellite data to go back beyond 1979 so there's no definitive answer. The phrase modoki tends to bring more tropical cyclone activity in the Atlantic is used a lot. I haven't found data to prove that so. If anyone does please feel free to! You could say EP Ninos are better at squashing activity but that's simple logic given they are the strongest anyway.

As why 2004 was such a strange active Nino for hurricane season. It was a very weak Nino even at it's peak so at best neutral conditions probably existed during the season. If one takes a look at the MEI index (covers atmosphere, sea temps, wind patterns etc) 2004 was more neutral like than Nino, the index never went beyond 0.672 and the average for that summer was even lower. This doesn't explain all why the devastating hurricanes happened but maybe we can clear up some modoki fog.

Credit to Ptarmigan's previous post on some of this data

[dexterlabio]

And I thought 2009 Nino was EP. so the fact that 2009 El Nino was a Modoki implies that central-based Nino does not always bring higher risk of tropical cyclone activity in the Atlantic, isn't it? i guess it's the winter season that would be surely affected by this.

that was a very nice explanation, thanks!

[NDG]

I don't know if I agree that 2009 was a Modoki year.

[Ntxw]

I don't know if I agree that 2009 was a Modoki year.

It is. I didn't believe it at first either but every source I looked at stated it was a Modoki year. Cold pool off of South America.



Wikipedia states: "A joint study by the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration concluded that climate change may contribute to stronger El Niños. El Niño "Modoki" events occurred in 1991-92, 1994–95, 2002–03, 2004–05, and 2009-10.[64] The strongest such Central Pacific El Niño event known occurred in 2009-2010.[65] There was also a Central Pacific El Niño in 2006-2007.[66]"

Another good evidence is that the 2009 El Nino had fluctuations with cooling periods driven by the weather. This is typically only the case in Modoki events. A true EP El Nino like 1997 and 1982 are not effected and are driven by Ocean thermocline forcing constant warming.

[NDG]

Giving the benefict of doubt that 2009/2010 was a Modoki year, it was definitely not present during the heart of the hurricane season, unlike 2004.

2009


2004


If it was, it was towards the end of the hurricane season, barely.

[Ntxw]

I do agree 2009 at the start did not appear that way. Most years listed do not. There's just not enough evidence to suggest 2004's modoki status says that every modoki year means business for hurricanes. However, strength of Nino does rather than is it modoki or not.

[NDG]

I don't know if I agree that 2009 was a Modoki year.

It is. I didn't believe it at first either but every source I looked at stated it was a Modoki year. Cold pool off of South America.



Wikipedia states: "A joint study by the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration concluded that climate change may contribute to stronger El Niños. El Niño "Modoki" events occurred in 1991-92, 1994–95, 2002–03, 2004–05, and 2009-10.[64] The strongest such Central Pacific El Niño event known occurred in 2009-2010.[65] There was also a Central Pacific El Niño in 2006-2007.[66]"

Another good evidence is that the 2009 El Nino had fluctuations with cooling periods driven by the weather. This is typically only the case in Modoki events. A true EP El Nino like 1997 and 1982 are not effected and are driven by Ocean thermocline forcing constant warming.

BTW, the picture you posted looks more like early 2010 versus 2009.

[Ntxw]

Sorry I should note my sources . It's November average of 2009. The site puts up that month since it's typically the peak of most Nino's

http://www.aviso.oceanobs.com...el-nino/chronology/index.html

[NDG]

Sorry I should note my sources . It's November average of 2009. The site puts up that month since it's typically the peak of most Nino's

http://www.aviso.oceanobs.com...el-nino/chronology/index.html

Well, I totally disagree with their image, if you go back to November 2009 it does not match.

http://www.ospo.noaa.gov/Products/ocean ... /2009.html

[Ntxw]

It's the average for the entire month. The Noaa product is a span of days.

Edit: This site is pretty cool too! Check out the video at the bottom animating the growth of Nino for 09. Fascinating...

http://www.myocean.eu/web/18-product-showcase.php?item=23

[NDG]

It's the average for the entire month. The Noaa product is a span of days.

Edit: This site is pretty cool too! Check out the video at the bottom animating the growth of Nino for 09. Fascinating...

http://www.myocean.eu/web/18-product-showcase.php?item=23

I think I am getting to bottom of it as to why there is so much discrespancy between that site and the NOAA site. Their image show height anomaly not SST anomaly like the NOAA site.

[jinftl]

NOAA's 'official' definition of el nino is:

El Niño: A phenomenon in the equatorial Pacific Ocean characterized by a positive sea surface temperature departure from normal (for the 1971-2000 base period) in the Niño 3.4 region greater than or equal in magnitude to 0.5 degrees C (0.9 degrees Fahrenheit), averaged over three consecutive months.
(NOAA News Online, Feb. 23, 2005)

So hitting the 0.5 deg C threshold doesn't technically mean we are in an el nino. The 3 consecutive month average is still in neutral and won't officially hit el nino probably for another month or more. I think that needs to be considered - the effects of reaching the 0.5 deg C threshold don't trigger some immediate reaction - the effects take a while to be felt and by then it could be September or even later in the season. One reason why NOAA increased their forecast for # of storms. From Aug 6 NOAA update:

“El Niño is a competing factor, because it strengthens the vertical wind shear over the Atlantic, which suppresses storm development. However, we don’t expect El Niño’s influence until later in the season,” Bell said.

[Ntxw]

I think I am getting to bottom of it as to why there is so much discrespancy between that site and the NOAA site. Their image show height anomaly not SST anomaly like the NOAA site.

You're right that seems to be the case. They are reflective of each other though so the difference isn't too much. Heights is simply the oceanic pattern reacting to it which effects weather downstream.

So hitting the 0.5 deg C threshold doesn't technically mean we are in an el nino. The 3 consecutive month average is still in neutral and won't officially hit el nino probably for another month or more. I think that needs to be considered - the effects of reaching the 0.5 deg C threshold don't trigger some immediate reaction - the effects take a while to be felt and by then it could be September or even later in the season. One reason why NOAA increased their forecast for # of storms. From Aug 6 NOAA update:

This is true but example, looking back in Oct saying July/August/September was .5 or greater doesn't do any good forecasting during the season. Take a look at each week and see how long it persists.

[SoupBone]

Just bumping the post with the SOI link.

30 day average now below -8.

http://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/30daysoivalues/

[cycloneye]

More evidence that is going to be a EastCentral Pacific El Nino (Modoki)

[KWT]

NOAA's 'official' definition of el nino is:

So hitting the 0.5 deg C threshold doesn't technically mean we are in an el nino. The 3 consecutive month average is still in neutral and won't officially hit el nino probably for another month or more. I think that needs to be considered - the effects of reaching the 0.5 deg C threshold don't trigger some immediate reaction - the effects take a while to be felt and by then it could be September or even later in the season. One reason why NOAA increased their forecast for # of storms. From Aug 6 NOAA update:

Whilst true, once you do get above say 0.7-0.8C changes can get going pretty quickly. Already I'm seeing a more tell tale El nino pattern just starting to take place in terms of the global circulations. The oceans will probably display a fusion until the El Nino pattern becomes more dominant.

Whilst we do have to wait for a little bit longer yet for the offical El Nino to be declared, we are in a technical El Nino, IE the SST's are +0.5C above average and the 3 month average WILL be 0.5C+ at some point in the near future for the required time from the looks of things. I'm not expecting anything too strong, think the cold PDO will keep this in check like it did with previous Nino's over the past few years, but it should be enough to at least result in a below average 2nd half of the hurricane season (the quick start should be enough though to ensure 12-14 storms IMO)

The one thing I am confident about is we won't end up with above average ACE even if the numbers do come in a little above.

[Ntxw]

Tahiti pressures (if I see correctly) will start it's dive tomorrow.

August 14th -Sorry making this post so I can look back later and see it's evolution

Here are the ENSO facts we know so far.

-MEI calculation is in El Nino territory for June/July 1.139 (and even this says it's been more than just weak). This means both atmosphere and ocean temps tell us it exists. July/August will be even greater if not top 5 for growing El Ninos since data has been saved

-SOI has spent more time negative than positive for the past 2 months and the negatives have been larger

-Westerlies is occurring in the dateline and EPAC

-Latest anomaly is 0.8c for 3.4 which is high any period if it is predicted to be a weak Nino.

Now we wait for CPC to announce it which they can't until Sept at the earliest due to the looking back rule. These are known facts, the rest is personal opinion and translation.

[NDG]

I was just looking at the GFS, Tahiti's pressure looks to stay in the average of 1013-1015 over the next few days, possibly lowering but not until next week.

[Ntxw]

Tahiti pressures (if I see correctly) will start it's dive tomorrow.

15 Aug 2012
Tahiti 1013.48
Darwin 1015.45

daily -21.79
30 day -9.78
90 day -7.75

Fell today and Darwin rose, SOI reflected it. Lets see if it continues to fall the next several days and give us -30s+ or rebound.

Latest forecast from the Euro for those wondering what the fall and winter might show.

Sept/Oct/Nov


Dec/Jan/Feb

[SoupBone]

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.

EDIT: So far I've found
1998 33 1002.58 1012.25 -69.19
2010 36 997.85 1009.85 -80.41