Ok, so no one will probably believe me on this, and I don't blame you, but the CFS, three weeks ago, was already showing this trough in the SW pattern. I think it was even back when it was showing the MJO doing the big loop through 8 and 1. I remember because it looked weird to me that it would drop a trough there with that MJO progression. I wish I had taken a gif of it then, just to go back as see if it did ok with the overall pattern idea. In no way talking specific storms at 700 hour leads, but if nothing else a western ridge would keep us from being on the right entrance region of a sub tropical jet and keep the flooding at bay:
Above image is the CFS pattern change