ENSO Updates (2007 thru 2023)

[AussieMark]

Summary: Pacific Basin remains primed for La Niña

Current conditions in the equatorial Pacific remain neutral. However the chance of a La Niña developing during 2007, and in particular over the coming 2 to 3 months, continues to be significantly elevated above the long-term likelihood of around 20%.

Although neutral, current conditions continue to display the precursors required for the development of a La Niña event. These include cooler than normal conditions in the Pacific Ocean subsurface - a situation that has persisted since mid-January - which have lead to cooler than average surface waters in the far eastern Pacific. Over the past two weeks, these surface waters have undergone further slow and steady cooling, though they remain largely confined to the eastern edge of the basin: a La Niña event occurs when this cooling is more extensive along the equator. Furthermore, Trade Winds remain enhanced near the dateline, and convection (high cloud) has continued to be reduced in the east and slightly enhanced in the west. The SOI, which dropped below −10 during April, has returned to near-zero. Such variations are not uncommon during the Austral autumn, and are not necessarily an indicator of the longer term climatic situation. The equatorial SOI, which is calculated using observations on the equator, has remained positive since February.

These conditions, combined with the fact that all major international coupled models show further cooling of the equatorial Pacific Ocean over the coming months, suggest that there is an elevated chance of a La Niña event occurring during 2007. Conversely, they suggest that the El Niño risk is very low. Historically, La Niña events bring wetter than normal conditions across much of the eastern half of Australia from autumn onwards.

In Brief

* Negative SST anomalies have strengthened in the far eastern equatorial Pacific.
* Negative subsurface anomalies persist in the vicinity of the thermocline all the way from the date-line to the South American coast.
* The SOI has a current (7 May) 30-day value of approximately −3.
* Trade Winds have generally been close to, or a little stronger than, average in the equatorial Pacific in recent weeks.
* Cloudiness near the date-line has recently been close to or slightly above average.
* All the dynamic computer models recently surveyed predict a La Niña in 2007.


Source

[cycloneye]

Now let's wait for the CPC (Climate Prediction Center) outlook that will be out tommorow.

[cycloneye]

The subsurface in the Pacific continues to show mixed signals.On one hand it's rather cool down in the subsurface in the Eastern Pacific to around 160w,in which El NIno 1-2 and 3 are located.But on the other hand El Nino 3-4 area continues to have warmer subsurface waters.In other words,La Nina is in not a hurry to be the dominant factor yet in terms of ENSO.Let's wait and see how the next few weeks evolve to see if La Nina wakes up or Neutral Conditions dominate thru the Summer and fall months in the Western Hemisphere.

[cycloneye]

Climate Prediction Center 10th of May Update

Nothing really new in this update from CPC.What I am looking for is how will ENSO be when the peak of the season arrives by August.I say it will be Neutral by that time but we will see about that.

[HURRICANELONNY]

I read that to. I'm sure you get there e-mail as many do. Your right nothing new. They use "possible" more often. Not to screw up like last year. I think it will be a neutral season.

[Tampa Bay Hurricane]

Whether it is La Nina or Neutral, I expect a very
active season.

[cycloneye]

Whether it is La Nina or Neutral, I expect a very
active season.

There haved been many active seasons with Neutral ENSO,including 2005,(Although I dont expect a 2005 repeat of 28 named storms in 2007).Someone can post the years when it has been Neutral ENSO and there haved been many active seasons.

[cycloneye]

Climate Prediction Center 5/14/07 Update



Here is the latrst update from CPC on May 14th.They are saying that within the next 1-3 months,a full transition to La Nina may occur based on the recent data which they show in this update.

[cycloneye]

Above is the latest graphic of the Pacific concerning ENSO and how the anomalies are doing.

[canegrl04]

Just in time for hurricane season to start.Get ready for a wild one

[AussieMark]

am I being to sceptical in thinking they say 1-3 months that it coincides with hurricane season in an attempt for people to be more aware?

I remember last year that El Nino was called earlier than it should of been and that was after a very quiet August-September period

[cycloneye]

IRI May ENSO Update



Interesting analysis from this independent firm that does monthly forecasts of ENSO.

['CaneFreak]

I found this to be a very interesting ENSO update. Comments anyone? I still think that it is going to be more of an ENSO neutral year due to the westerly wind burst in the WPAC as of late as described in the above article. However, I could be wrong and I may have to eat my words yet again.

[AussieMark]

I agree with you. Its looking neutral

remember its Nino 3.4 that has to have a 3 month average of -0.5C anomality

so far its only been 1 week of anything below normal ssts and that was quite some time ago

[cycloneye]

Here is the latest graphic of how the Pacific anomalies are doing.Cool waters at el Nino 1-2 and 3,while El Nino 3-4 is a little more warmer.

[cycloneye]

http://www.bom.gov.au/climate/enso/index.shtml

This is the update from the 30th of May from the Aussies or BoM about ENSO.They are pretty confident that eventually La Nina will make an appearence in the comming months,despite the status of Neutral that the Pacific is now and does not seem to change a whole lot.

[windstorm99]

Lastest ENSO update for june 7...

Nearly all of the model forecasts predict below-average SSTs in the Niño 3.4 region (5oN-5oS, 120-170oW) during the remainder of the year. Most statistical models show ENSO-neutral conditions persisting through August 2007, while most dynamical models indicate La Niña will develop within the next three months (Fig. 5). Some forecast models, especially the NCEP Climate Forecast System (CFS), continue to predict a rapid transition to La Niña by July 2007. However, for the past few months the CFS forecasts have been predicting a stronger and more rapid cooling than has actually occurred. Historically, the next few months are a favorable period for the development of La Niña.

More Here

[Frank2]

Still, if the La Nina does not develop as first thought, then, it would mean lower overall activity in the Atlantic basin...

There are many factors that make up an active season - some scientists recently hypothesized that increased temps brought on by Global Warming might actually increase shear, so...

[Scorpion]

Not so sure about that... neutral years have proven to have more named storms than La Nina years

[Frank2]

Yes, but, neutral to me means that the atmosphere can vary between favorable or unfavorable, so, it just depends on how long one remains rather than the other...