Losing his grip on ENSO: Bob Tisdale thinks he's an expert, and yet...

Bob Tisdale fancies himself as an ENSO expert, yet he doesn't show that in his WUWT article today (archived here). He's complaining that a couple of days ago NOAA removed the "watch" status for La Nina. Bob's headline was "NOAA Cancels La Niña Watch While La Niña Conditions Exist". Well, he seems to be the only person who thinks La Nina conditions exist. Oh, except maybe for Anthony Watts who, way back in June, declared that we are already having a La Nina.

Today Bob Tisdale wrote:

Regardless of the existing (and strengthening) La Niña conditions, NOAA has canceled its La Niña Watch, which had been in effect since April.

Except there are not conditions currently existing for La Nina. Bob's wrong. This is where he was wrong - almost everywhere:

1. Bob didn't base his assessment on the ENSO definition's standard of the ONI, which is a 3 month running mean;
2. He based his current sea surface temperature anomaly in the Nino 3.4 region on the wrong average baseline, making it appear approx 0.4 C colder than it is (the cutoff is -0.5 C) (h/t Rattus Norvegicus);
3. He used the wrong dataset (Reynolds OI v2), not the one used as standard for ENSO estimates (ERSST v4).

Summary added by Sou 4:57 pm 10 September 2016

What seems to have happened is that Bob got the definition of La Nina wrong, which surprises even me. He wrote:

La Niña conditions are typically defined by NOAA as sea surface temperature anomalies less than or equal to -0.5 deg C for the NINO3.4 region of the east/central equatorial Pacific. 

Different agencies have different definitions for the conditions required for La Nina. They share some of them, such as that "During La Niña events, there is a sustained strengthening of the trade winds across much of the tropical Pacific". Currently the trade winds are fairly normal - not characteristic of La Nina. BoM reports:

Trade winds near the equator in the Pacific Ocean have remained close to average for the 5 days ending 28 August, and have remained generally so since March.

Contrary to what Bob wrote about NOAA, that agency defines La Nina in terms of the Oceanic Nino Index. That's the three month running mean of the sea surface temperature in the Nino 3.4 region, not the temperature anomaly at any one time. Because of global warming, sea surface temperatures are increasing, so NOAA adjusts the base period for the ONI every five years. The current base period is 1986 to 2015. This is explained on the NOAA website:

...ONI values during 1950-1955 will be based on the 1936-1965 base period, ONI values during 1956-1960 will be based on the 1941-1970 base period, and so on and so forth.

In real-time operations, the past 30-year base period (e.g. 1986-2015) will continue to be used to compute the departure from average. However, CPC will create an additional 30-year base period every 5 years (the next update will be at the beginning of 2021).. When these 5 year updates occur, the ONI values over the most recent decade will change slightly because of the inclusion of more recent data.

What that means is that even with the most recent warming factored in, the ONI still isn't at La Nina threshold levels. (If an older base period had been used it would be even further from the threshold.) The current and past ONI values are shown here. For the most recent three month running means, the values are as follows:

• AMJ 0.6 (April, May, June)
• MJJ 0.1 (May, June, July)
• JJA -0.3 (June, July, August)

So it's not at -0.5 C 3-month running mean yet, and the chances are getting higher that it won't make it, according to NOAA.

The BoM ENSO update is always available in the sidebar. Although it's had a La Nina watch for some time, for most of that time the BoM reports have indicated that if we get one (and the chances it gave were at best 50/50) then it was likely to be weak. The latest report was the weakest of all. The next report is due next Tuesday so it will be interesting to see what it says.

Incidentally, BoM uses the Southern Oscillation Index (SOI) as a measure of ENSO, as well as other indicators such as the strength of the trade winds, sea surface and sub-surface temperatures. For the SOI:

Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between about +7 and −7 generally indicate neutral conditions.

Here is the BoM model outlook from 31 August 2016. Most of the model runs show that the Nino 3.4 sea surface temperatures have bottomed and are expected to rise:

I can understand the deniers' disappointment that La Nina isn't bringing the expected ice age. While there's still a chance of a La Nina this year, it's looking less and less likely.

From the WUWT comments

In among the comments from rational people, there were the usual from the conspiracy theorists. Dr. S. Jeevananda Reddy is one such person who seems sure that a La Nina is on its way and the scientists are conspiring to hide the fact:

September 9, 2016 at 3:52 am
ENSO nuetral condition means, the temperature anomaly must be flat with ups and downs. At present no such scenario is evident but on the contrary the El Nino peak coming down steadily, a La Nina condition similar to 1997/98. Unfortunately science is misused for the selfish gains, There is a strong need to stop such tendencies in scientific institutions.
Dr. S. Jeevananda Reddy

tadchem is another conspiracy theorist, though I've no idea to what he's referring:

September 9, 2016 at 5:47 am
Never let the data get in the way of a politically productive hypothesis.

Clyde Spencer  is another one. His reasoning is not reasonable. Remember that until this week, NOAA was reporting a La Nina watch, so Clyde's comment makes no sense.

September 9, 2016 at 9:01 am
Kevin,
NOAA thought it worthwhile reporting. I suspect that is part of the intention to scare the public with reports of high temperatures with little chance of declining. The problem is, if their forecast turns out to be wrong, they will have egg on their face.

Our new fan ptolemy2 must be looking in the wrong place, putting up an old chart at WUWT. I'll give him or her a helping hand - and for future reference the entire archive.

September 9, 2016 at 8:04 am
Can anyone say why the BOM monthly subsurface Pacific ocean equatorial temperature anomalies down to 400 meters, has stopped at March 2016:

It took a good couple of hours before anyone realised (or commented) that Bob had his criteria wrong. It was Kevin in NH who first pointed this out:

September 9, 2016 at 6:08 am
I think the official designation for La Nina would be 3 consecutive months or more with -0.5C anomalies or colder.
#1 This makes any declaration of La Nina (or El Nino on the other side) overdue as it is not official until it has been going on for at least 3 months.
#2 Most of the recent forecasts I have seen show the anomaly hanging out just about at 0.5C for a couple of months then returning very close to zero, not a steep, long lived drop into Nina territory.
So yes the conditions exist right now but may not make the 3 month threshold.
And “global warming” is NOT the cause of a huge Nino not turning into a huge Nina.

A little while later Richard M pointed to another problem with Bob's unfounded claims:

September 9, 2016 at 6:33 am
The problem is the trade winds have yet to pick up. Since they normally don’t start doing this during the NH summer I’m not sure what the NOAA changes are based on. If the models are based on those summer winds then their ability to predict La Nina will not be very good.The issue will be what happens in October and thereafter.

Perpetually joyfilled (some might say perpetually hysteric) Janice Moore was quite overwhelmed, as usual, with Bob's cleverness:

September 9, 2016 at 9:29 am
Thank you, Bob Tisdale — for more GREAT analysis. What a gift to the world you are: a true humanitarian in your persevering efforts to get the facts out there.
How was your first long holiday in YEARS (if I am not mistaken)? I hope that it was wonderful.
Janice

Top image source: Bureau of Meteorology