Just to clarify, JPL is part of NASA and not NOAA.  Many scientists (not only Bill) are asked by reporters to give their opinion on what may happen, but this doesn't necessarily line up with the seasonal forecasts coming from NOAA CPC.   If you want to see the official NOAA outlooks, then I recommend directly consulting this webpage:  

http://www.cpc.ncep.noaa.gov/products/predictions/long_range/

The CPC seasonal outlook is put together by a team of forecaters who put together these forecasts *every month* (El Nino or not).   It is consensus based and strongly data/model driven.   It is much more difficult to put together a forecast based on team consensus vs. offering one's own opinion.  Also, unlike individual forecasts, these outlooks are verified (or graded) regularly.   So I think it's important to distinguish individual opinion from the collaborative work of professional NOAA seasonal climate forecasters.  

The blocking high seems to be a feature that has dominated the 1-month average (February), but one month isn't enough to dominate the seasonal (3-month) average.  I suspect the DJF (Dec-Feb) average will likely show wetter than average conditions in northern California, so arguably the blocking high hasn't been persistent or forceful enough to keep the state entirely dry during the DJF period.  Also, I think the large scale pattern is starting to look more favorable for wetter conditions in March (though these wetter conditions will not necessarily get CA out of the drought, which is a message NOAA has stated consistently since last year).