These two models are forecasting an average of 500mb height anomalies between Hour 168 and Hour 240- also known as between 8 and 10 days away. Let's take a look at a few key points to help us see if this really is the end of the stormy northeast Pacific pattern.
1. The ECMWF is on board.
The ECMWF model is widely regarded as the best model currently in service, with a verification score higher than the GFS. The ECMWF has been known to catch significant events before other models. For example, the ECMWF forecasted a Northeast landfall by Hurricane Sandy while the GFS was way out to sea. If it were a battle between these two models, I would favor the ECMWF.
2. Both models show a location change in this stormy pattern.
Putting aside the difference in how good one model is over the other, both models are showing a change in where this stormy pattern is. The ECMWF eliminates the stormy trend altogether, while the GFS moves it onshore into southwest Canada. While the GFS change may not seem like much, this slight shift east paves the way for a positive PNA pattern to come back- something that cannot happen when the stormy pattern is prevalent in the NE Pacific.
It will take some more time to investigate this potential, but it is appearing possible that this warm pattern that has (and still is) affecting much of the nation may collapse in the next week to 10 days.