You might remember that the forecast for ENSO for this year was for La Nina to go away during the summer but potentially return in the fall. This is called double-dipping, since we have two years in a row with a La Nina. It happens from time to time with La Nina but almost never with El Nino. A new extended story in the Climate.gov ENSO blog discusses why this asymmetry exists and what it could potentially mean for long-term climate predictions.
