The spring prediction barrier is a period of low skill/forecast accuracy when forecasts are made just before and during the spring.  So while our forecast time horizons will gradually move forward and you will see probabilities for ENSO state for the next fall/winter, we do prefer to get through the spring before being a bit more assertive about what may happen.  I like to say start paying attention around June, but there are times when ENSO evolves more rapidly, and we know before then.  So just stay posted!