For more local impacts, you might consider seeking out your local NWS office for more specific information.   At CPC there is a collection of large-scale El Nino impacts and diagrams which you can review by clicking HERE (though please note the box and whisker links are more regionally focused). 

Also, you can access the CPC seasonal temperature and precipitation outlooks HERE .  These are updated on the third Thursday of every month.  At this time, there is a very slight tilt toward above-average precpitation for the Bay area, but this may change as we move closer to the event.  Also keep in mind these maps show shading that reflects probabilities (% chance of) of the *favored* category, so there are still chances for near or below average precpitation.