For the past 5 months, the Oceanic Niño Index (ONI) has been stuck in the middle of the Weak El Niño category (i.e., +0.50 and +1.0) and the models are keeping it in that range through the end of the year! Going back to 1950 (https://ggweather.com/enso/oni.htm) there are only three back-to-back years with kind of similar patterns, but none close enough in my estimation to be reasonable analogs. They were 1968-69 to 1969-70, 1986-87 to 1987-88, and 2014-15 to 2015-16. California precipitation patterns related to El Niño years can be found at https://www.ggweather.com/ca_enso/ca_elnino.html.
Current SST Temperatures with Niño Region insets
Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services