In looking at past La Niña events, the one thing that is clear is that almost anything can happen when it comes to winter precipitation across the Golden State. The images below show the "average" precipitation for the 20 previous La Niña events going back to 1950 but more importantly the wide range from the driest to the wettest California winters (Nov. - Mar.) for each of the categories (Weak, Moderate and Strong). [Additional images and data can be found at US Winter Precipitation & Temperature Climatology: La Niña and California Climatology of La Niña Events and Precipitation]
The bottom line is that it is too early to tell the strength of forecast La Niña and more importantly even within a specific strength category the range of solutions leaves no clear signal based on the past climatology.
Jan Null, CCM
Golden Gate Weather Services