Some work has been done on transition years, but we just don't have enough examples in the observed record to draw solid conclusions. Also, I think it would be tricky to separate the impacts due to ENSO transition from the overall climate change signal. However, one known delayed impact that Nat wrote about is the relationship between La Nina winter and extreme heat in Texas the following summer: https://www.climate.gov/news-features/blogs/enso/la-ninas-delayed-effec….