El Nino Forecast:

There is an approximately 95% chance that El Niño will continue through Northern Hemisphere winter 2015-16, gradually weakening through spring 2016.

For official report go to http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

Summary:   El Nino official materialized in the spring of 2015 and has slowly intensified through the summer.   All models surveyed predict El Niño to continue into spring 2016, and all multi-model averages predict a peak in late fall/early winter. The forecaster consensus unanimously favors a strong El Niño  

What does this mean for the PNW?

During an El Nino event, the Pacific Jet Stream often shift southward which make precipitation more likely to occur across the southern tier of the US.   As fall progresses,  the PNW can expect a decrease in average rainfall and warmer than average temperatures.

The Blob Effect:

There has been recent chatter about how The Blob (the large area of warm water off the west coast) is going to affect the jet stream and counter the El Nino effect.

 El Nino is expected to dominate the large-scale pattern over the PNW.   This is a game of sheer scale of atmospheric physics. The Blob is not capable of changing the overlying pattern in any significant way.  El Nino will likely have an effect on the Blob, not the other way around.

There ya have it.

JDM.