I guess its just sort of 'bad luck" and bad timing. The PV is perturbed and the strongest piece has been sliding down over eastern Canada, and that has been pretty well modeled. All of these tropospheric 'daughter' vortices are a reflection of that. Too much of a good thing. Take a look at the h10 height anomalies as we head towards Sun-Mon. Impressive, but also in this case it translates to suppression. Of course beyond that it lifts out and shifts over towards Europe.