The biggest wild card in the weather for this year is the (massive) 5 to 10% greater global stratospheric water vapor content due to the injection of seawater from the Tonga volcano. It's an event unprecedented in our lifetimes. Everything I read details how little we understand and have modeled such an occurrence- a gigantic and long-lasting (it will take years for the extra water vapor to dissipate) change to something that we think of (and model) as utterly constant and stable. 

I like your work, but would encourage you to look up and not down for a cause of the weirdness (it's literally snowing in most of California today) that we are experiencing this year.