Fast pacific jet will have shortwaves coming in further north. Shortwaves cutting are the issue.
Case in point, the GFS OP.
The erosion of heights out west means shortwaves can't dig south and take that coveted coastal track. Instead they'll move quickly ENE and best case drop a couple inches if the antecedent air mass is cold enough, otherwise it'll be rain.
On the plus side the GEFS are showing less troughiness out west, probably has something to do with the big rise in the PDO