I was a bit hesitant at first to ask this question here because I'm not sure if it applies to ENSO, but I can't seem to find the answer anywhere else so here goes.. I've read a lot about the "period of uncertainty" (my paraphrase) in the northern hemisphere spring and how you have to get past that period to have the best possible chance of seeing a clear ENSO picture for the following fall/winter. When it comes to long range forecasting in general, is there also a period of uncertainty in the northern hemisphere autumn as well? Or is it only spring?