I have always weighed the Pacific heavily in my forecasting.
I frequently look to the WPO / EPO and ultimately to the AO as a predictor of temperature anomalies.
My approach is that the Pacific is a dominant force and my forecasting reflects that.
My belief is find the best upward motion and you will find your 500 pattern.
A cool / dry I/O grabs my attention because IMO if that signal remains strong the sinking air there will promote upward motion to its east.
I believe it's near the D/L.
So when I look at the warming between 150 and 180 I take a stand as to where the best upward motion should occur.
I like the similarities in the fall of 02 and 14 here and I look to FEB as our best month.
Those 500 maps are what I think could happen but are in no way the foundation of my forecast, rather just an ally.