The latest #ENSO diagnostic discussion is hot off the presses, adiós #ElNino — Climate Prediction Center

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

issued by
and the International Research Institute for Climate and Society 8 August 2019
ENSO Alert System Status: Final El Niño Advisory

Synopsis: El Niño has transitioned to ENSO-neutral, which is most likely to continue through Northern Hemisphere winter 2019-20 (50-55% chance).

During July, ENSO-neutral conditions were reflected by the combination of below-average sea surface temperatures (SSTs) in the eastern equatorial Pacific Ocean and above-average SSTs in the central Pacific. The latest weekly ENSO indices were +1.0°C, +0.5°C, -0.2°C and -0.5°C in the Niño-4, Niño-3.4, Niño-3 and Niño-1+2 regions, respectively. Upper-ocean subsurface temperatures (averaged across 180°-100°W) were near average throughout the month, as anomalously cool waters prevailed in the eastern Pacific and anomalously warm waters continued in the central Pacific. Suppressed tropical convection continued over Indonesia, while near-average convection was observed near the Date Line. Low-level wind anomalies were near average over the tropical Pacific Ocean, and upper-level winds were easterly over the east-central Pacific. The traditional and equatorial Southern Oscillation Indices remained slightly negative. Overall, oceanic and atmospheric conditions were consistent with a transition to ENSO-neutral.

The latest IRI/CPC plume of forecasts of the Niño-3.4 index favors ENSO-neutral (Niño- 3.4 index between -0.5°C and +0.5°C), with index values greater than zero from late Northern Hemisphere summer into fall, warming closer to the El Niño threshold (+0.5°C) by winter. Atypically, dynamical models forecast weaker positive SST anomalies than statistical models throughout most of the forecast period. As a result, while forecasters favor ENSO-neutral conditions, the odds of El Niño (~30%) are roughly twice that of La Niña for next winter. In summary, El Niño has transitioned to ENSO- neutral, which is most likely to continue through Northern Hemisphere winter 2019-20 (50-55% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

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