The GFS Ensembles today… in conjunction with the 12z ECMWF and the 12z Canadian suggest an increasing probability of a scenario where the southern-most jet streak at the base of the very deep Pacific trough will eject northeastward into the intermountain-west/northern Rockies early next week. After this wave moves northeast… subsequent jet maximas will continue to move into the west it appears… re-orienting the trough as it slowly shifts east. This scenario could indeed significantly break down the very amplified “destructive” ridge over the Plains.
GFS Ensemble forecast from today’s 12z run:

There is still a lot of uncertainty in how this first wave moves into the west… and it may indeed be a slower evolution than the models show…especially the GFS and its ensemble members. It’s good to the the ECMWF show a significant height fall situation over the west promoting downstream west-southwesterly flow into the Northern Plains. It’s looking more and more like we will indeed have a couple chase days right away in the northern plains…albeit with somewhat limited moisture I would imagine. It looks like a good chaseable pattern beginning to evolve in the Day +7 progs with a little more congruence among the ECMWF, Canadian, and GFS (and ensembles).
Here’s today’s GFS runs:
GFS 500mb:

GFS Surface:

And to continue the game, here is today’s “GFS Deterministic dart”…. it’s really close to yesterday’s actually:
