The latest El Niño/Southern Oscillation (ENSO) diagnostic discussion is hot off the presses from the Climate Prediction Center

Mid-September 2014 plume of ENSO predictions
Mid-September 2014 plume of ENSO predictions

Click here to read the latest discussion. Here’s an excerpt:

Synopsis: El Niño is favored to begin in the next 1-2 months and last into the Northern Hemisphere spring 2015.

During September 2014, above-average sea surface temperatures (SST) continued across much of the equatorial Pacific. The weekly Niño indices were relatively unchanged from the beginning of the month, with values ranging from +0.3°C (Niño-3.4) to +1.1°C (Niño-1+2) at the end of the month. The change in subsurface heat content anomalies (averaged between 180o-100oW) was also minimal due to the persistence of above-average temperatures at depth across the central and eastern Pacific. Equatorial low-level winds were largely near average for the month, though brief periods of westerly wind anomalies continue to arise. Upper-level winds were also close to average for the month. The Southern Oscillation Index has remained negative, and rainfall was near average around the Date Line, with a mix of positive and negative anomalies over Indonesia and Papua New Guinea. The lack of coherent atmospheric and oceanic features indicates the continuation of ENSO-neutral.

Most models predict El Niño to develop during October-December 2014 and to continue into early 2015. The consensus of forecasters indicates a 2-in-3 chance of El Niño during the November 2014 – January 2015 season. This El Niño will likely remain weak (3-month values of the Niño-3.4 index between 0.5°C and 0.9°C) throughout its duration. In summary, El Niño is favored to begin in the next 1-2 months and last into the Northern Hemisphere spring 2015 (click CPC/IRI consensus forecast for the chance of each outcome).

Leave a Reply