NOAA Quietly Rescinds Faux El Nino

Econintersect: On 05 March 2015 NOAA (National Oceanic and Atmospheric Administration) posted a news release: NOAA: Elusive El Nino arrives. The headline was accompanied by the subtitle: “Forecasters predict it will stay weak, have little influence on weather and climate.”

Click for large image at NOAA.

Media reports appeared immediately with headlines such as After Much Ado, El Niño Officially Declared (Climate Central, 05 March 2015) and El Nino Officially Declared for 2015 (Scientific American, 05 March 2015). But Sig Silber wrote in his next weekly GEI Feature global weather and climate column, following the announcement (09 March 2015):

Media who have run with a story that an El Nino has been declared are premature.

Sig Silber continued to follow the status of El Nino conditions and within a few weeks was referring to the situation as a “faux El Nino“.  The status of El Nino conditions were reported every week with the continuing doubtfulness of there actually being an El Nino in progress, drawing especially on climatology reports from agencies in Australia and Japan, as well as his own interpretations of the climate systems maps and data published by NOAA itself.

Finally a change was made by NOAA which clearly identified that the agency recognized that there had been no El Nino in the early months of 2015. But when was that done? We asked Silber and he replied:

It is not clear when NOAA made their determination because data was not summarized until very recently. [Editor’s note: See below.] Whenever they revised their data they did not announce it in a clear manner. I pour over their reports and posted data in depth every week and I never saw the change until last week.

Here are two key data displays which NOAA uses to summarize data each week. The first is as published 15 June 2015 and is consistent with the tables published in every prior month. Note the red rectangles for the last seven entries (El Nino conditions,warm Pacific). The second display was posted to replace the first one soon after 15 June. Note the backward revision to remove “warm Pacific” all the way back to September (SON).

We asked Sig Silber for his comments about this and he suggested that we could not print what he would say if he spoke frankly. He added that this is a very serious matter for weather sensitive businesses that are planning for a particular type of event, as described by NOAA, when it is not actually occurring.  But then he added:

“This change in the graphics was part of NOAA’s updating process and was not inappropriate.  But because such a significant change was made there should have been either an earlier indication of uncertainty or a detailed explanation at the time the change was made.  In an ideal world we would get both.”

John Lounsbury