The just updated NOAA Climate Prediction Center (CPC) El Niño Advisory has reduced their probability of the occurrence of El Niño in the eastern tropical Pacific this fall and winter from nearly 82% in June down to 66%. This is not surprising given the gradual decrease in the previous Sea Surface Temperature (SST) anomalies (and subsurface anomalies) in the eastern Pacific and the corresponding less robust ONI (Oceanic Niño Index) plume forecasts for later this year.
This is also reflected in the latest ONI (Oceanic Niño Index) and Multivariate ENSO Index (MEI) analyses which have shown a slowdown in the warming of the eastern Pacific.
Also, keep in mind that an El Niño that was forecast in August 2012 for the winter of 2012-2013 never materialized.
In regards to the ongoing drought in California, it must be reiterated that even the occurrence of El Niño is never a guarantee of a wet winter AND that California can have wet winters in non-El Niño years! See Myths and Realities of El Niño, Climatology of El Niño Events and California Precipitation and El Niño & La Niña...Are They Related to California Flooding?
For additional information see the El Niño/La Niña Resource Page.
Jan Null
Certified Consulting Meteorologist
Golden Gate Weather Services