Bob Tisdale is the El Niño monitor guy that I pay attention too, rather than the folks at NOAA. Bob has written extensively on the subject at Watts Up With That and has published several books on the subject.
NOAA has finally declared a weak El Niño for 2014/2015, and a stronger one for the coming 2015/2016 winter. Usually an El Niño event brings more moisture to California, but Bob has some caution for those expecting a break in the drought:
If you live in California and are hoping for drought relief, I wouldn’t get my hopes up just yet. It’s still (boreal) springtime, and ENSO forecasts have a hurdle called the “spring prediction barrier”. Basically, El Nino forecasts have a bad history during and before boreal spring. [See of Torrence and Webster (1997) The annual cycle of persistence in the El Niño/Southern Oscillation for more info on the spring prediction barrier.] The spring prediction barrier is especially true for El Niño development predictions…not so much for El Niño decay or La Niña development and decay. [See Duan and Wei (2013) The ‘spring predictability barrier’ for ENSO predictions and its possible mechanism: results from a fully coupled model.]
I would not be making any plans for a wet spring and moist summer until we actually see significant changes in the Pacific water temperatures. Bob will let us know when it is time to start celebrating and lengthening our showers. Stay tuned.