Looking at the historical ONI-values from 1950 and onward reveals that only twice a La Niña have developed if the ONI-value in July-August-September was above -0,5. The last time was back in 1984 when the ONI-value didn't dropped below -0,5 until September-October-November. The result was a moderate La Niña. The other case is from 1967, a very late case, when the ONI-value didn't drop below the threshold until November-December-January(!) The result was a weak La Niña. GFS forecast a strong easterly wind burst to emerge in the next couple of days. Let's see if it will have any real effect.