Even as El Niño continues to influence this winter's weather, questions are arising about whether there is a La Niña on the horizon for next winter. There seems to be a general impression that La Niña is expected to follow El Niño. The following is a breakdown of all the El Niño events and what ENSO events occurred the following winter.
In summary and considering all El Niño events, they only transitioned to La Niña less than half the time (i.e., 10 out of 23), with 7 years become Neutral and the final 6 remaining as El Niño. Breaking out just the five strong and very strong El Niño's, 3 of these became La Niña, with the the other two splitting one each into the weak El Niño and Neutral categories.
The latest IRI/CPC plume of ENSO predictions for next fall/winter is characterized by a broad range of solutions from remaining as an El Niño to well into the La NIña category. The average, of all the models, straddles the line between neutral and a weak La Niña with -0.5 for Nov-Dec-Jan.
BOTTOM LINES: First, there is currently no definitive answer about the character of ENSO for next winter; either from past climatology or the forecast models. But more importantly (and as a lesson learned from the current El Niño) is that even within a particular category of ENSO there are lots of subtleties that affect the ultimate impact on related weather patterns. Stay tuned.
Jan Null, CCM
Golden Gate Weather Services