ENSO Updates (2007 thru 2023)

[KWT]

Hmm interesting though the immediate subsurface below ENSO 3. has actually eased off a little...

[abajan]

I found an error in the El Nino years list by Dr Master's post as 2002 was in an El Nino year and not 2001 that was Neutral.

According to this chart, if I’m understanding it correctly, there are generally more cyclones in neutral years than in La Niña years. That’s interesting.

[cycloneye]

Yes abajan,the trend is for more tropical activity with Neutral ENSO.But the real favorable conditions for the Atlantic is to have La Nina as the windshear goes down bigtime.Also,the tracks when it is Neutral tends to be fish for the most part,while in La Nina,they go more west.

[cycloneye]

Climate Prediction Center 6/28/10 weekly update

Nino 3.4 mantains at the number of threshold of La Nina -0.5 and Nino 3 is at -0.7,a sign that the official proclamation is comming in the next 2-3 weeks.

Last Week Numbers

Niño 4= 0.0ºC
Niño 3.4= -0.5ºC
Niño 3= -0.6ºC
Niño1+2= -0.7ºC


This Week Numbers

Niño 4= -0.1ºC
Niño 3.4= -0.5ºC
Niño 3= -0.7ºC
Niño1+2= -0.3ºC

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

[cycloneye]

La Nina is here.Is only a matter to make it official by Climate Prediction Center. IMO,next week's monthly update may be the time to pull the trigger.

[cycloneye]

The CFS (NCEP) model now is forecasting a Moderate to Strong La Nina by the peak of the season (ASO)

http://www.cpc.ncep.noaa.gov/products/a ... cast.shtml

[cycloneye]

Climate Prediction Center 7/6/10 Weekly Update

Nino 3.4 continues to go down now at -0.6C at Weak La Nina threashold. I guess CPC will declare officially La Nina if not in next thursday's montly update, then in the August one.

Last Week Numbers

Niño 4= -0.1ºC
Niño 3.4= -0.5ºC
Niño 3= -0.7ºC
Niño1+2= -0.3ºC


This Week Numbers

Niño 4= -0.2ºC
Niño 3.4= -0.6ºC
Niño 3= -0.7ºC
Niño1+2= -0.9ºC


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

[cycloneye]

The POAMA model (Australian) continues to forecast Weak to Moderate La Nina thru the end of this year.

[KWT]

Hmmm so we are now in 1995 region with regards to the strength of the La Nina. I'm hoping the La Nina strengthens further because where it is at now is perfect for a huge season IMO.

[bvigal]

Hmmm so we are now in 1995 region with regards to the strength of the La Nina. I'm hoping the La Nina strengthens further because where it is at now is perfect for a huge season IMO.

So KWT, you are hoping it gets stronger, in order to result in LESS storms? I'm 'hoping' that's what you mean!

[cycloneye]

bvigal,what KWT may be referring to is about La Nina causing somewhat less activity in the Atlantic believe it or not.Look at the chart below.

[KWT]

Yeah typically stronger La Nina's don't have quite the same number of systems have neutral or weak La Nina's...

That being said it may all be a moot point given the La Nina is taking its time, probably won't be beyond a mid-weak La Nina in ASO...

[bvigal]

Thanks, guys!

After I read it more slowly the second time, I was pretty sure that's what KWT's comment meant. I only wanted to clarify, in case anyone else had my first impression.

Yes, Luis, I had seen the chart posted earlier - very interesting!! And, your comment was right, "Also,the tracks when it is Neutral tends to be fish for the most part,while in La Nina,they go more west." So maybe we should root for the weakest La Nina possible.

I know, lots of storm 'fans' here love it wild and crazy, and it IS an adrenalin rush. But, my enthusiam wanes more with each passing year of reality - watching carefully, yet praying for a healthy serving of "fish and poofs"!!!

[thetruesms]

bvigal,what KWT may be referring to is about La Nina causing somewhat less activity in the Atlantic believe it or not.Look at the chart below.

[img]http://www.wunderground.com/hurricane/2010/since1995_dean.jpg[img]

I dislike this image, because it implies that La Nina seasons are inherently less active than Neutral seasons, when there doesn't appear to be any statistical significance to that claim at all. Toss out the outlier 2005 season, and suddenly Neutral and La Nina seasons are much closer together.

If someone with statistical software feels like throwing the numbers in, or perhaps if I get some time to do the calculations manually, I can investigate the validity a little more rigorously. But with so little data in these sets, I'm not sure how much there is to be gleaned from it.

[KWT]

Usually the reason why La Nina's have a little lower numbers, esp moderate La Nina's in the ASO time, is because they tend to have slow starts. In many ways both 1998 and 1999 were perfect examples of that occuring. 2007 however actually was a weak La Nina in ASO and only really got going in the late Autumn.

The meat of the season tend to be a little busier in La Nina seasons though and the latter tends to be a little more active as well.

[cycloneye]

Climate Prediction Center 7/8/10 Monthly Update

Below is the July update by CPC where they say La Nina will be officially declared later in July or in August.

http://www.cpc.ncep.noaa.gov/products/a ... odisc.html

Synopsis: La Niña conditions are likely to develop during July - August 2010.

During June 2010, sea surface temperature (SST) anomalies continued to decrease across the equatorial Pacific Ocean, with negative anomalies expanding across the central and eastern Pacific (Fig. 1). While the rate of decrease slowed during June, all of the Niño indices were cooler compared to the previous month (Fig. 2). The subsurface heat content (average temperatures in the upper 300m of the ocean, Fig. 3) also remained below-average during the month. Subsurface temperature anomalies became increasingly negative in the east-central equatorial Pacific and extended to the surface across the eastern half of the basin (Fig. 4). Also during June, enhanced convection persisted over Indonesia, while the area of suppressed convection strengthened and expanded westward over the western and central equatorial Pacific (Fig. 5). Enhanced low-level easterly trade winds and anomalous upper-level westerly winds prevailed over the western and central equatorial Pacific. Collectively, these oceanic and atmospheric anomalies reflect developing La Niña conditions. .

The majority of models now predict La Niña conditions (SST anomalies less than or equal to -0.5oC in the Niño-3.4 region) to develop during June-August and to continue through early 2011 (Fig. 6). Confidence in this outcome is reinforced by the recent performance of the NCEP Climate Forecast System (CFS) (Fig. 7), the large reservoir of colder-than-average subsurface water (Fig. 3), and signs of coupling with the atmospheric circulation. Therefore, La Niña conditions are likely to develop during July-August 2010.

[cycloneye]

La Nina cound hinder oil cleanup efforts

[KWT]

I think the idea that it means more hurricanes is almost the same now as the whole idea of the QBO role used to be like, whilst it can have an impact, the difference in La Nina and neutral in a warm AMO tends to be more in the realm of steering currents rather then just 'more hurricanes, indeed as the stats show, there tends to be slightly less in terms of numbers in La Nina's then in neutral seasons during the most recent AMO cycle at least...I'm guessing La Nina's become more important in cold AMO cycles...

No doubt the best ENSO evolution is a warm phase winter, then weakening to neutral/weak La Nina for the summer...most of the big seasons in history have had that sort of profile....and thats what we have this year...

[frederic79]

Someone may of already posted this but here is the link to an AP article just released regarding the return of La Nina and its expected effect on the 2010 hurricane season.

http://www.google.com/hostednews/ap/art ... wD9GQVAP04

[cycloneye]

One more signal that La Nina is here,is the SOI index that continues strongly in positive territory. The holdout for declaring ENSO officially in La Nina status is Climate Prediction Center, but as I posted last week, they said in the last bulletin La Nina will be declared by late July or in August. The pending question is how strong this La Nina will be,but some ENSO models are very bullish on a moderate to strong La Nina.

Daily SOI Values

http://www.longpaddock.qld.gov.au/seaso ... /index.php

Daily 30 day SOI Text

http://www.bom.gov.au/climate/enso/soi.txt