The 18Z GFS run on Climate analyser sees a big storm taking over most of the basin later in the run, not quite a GAC, but lots of fairly strong wind. The EC today on Windy disagrees, so we'll have to wait and see. (both see continuing injections of heat and moisture especially over the Canadian and Pacific sectors and adjacent CAB).
If the AO turns negative now, with an increase in cloud and possible storms, just as the sun is getting low at high latitudes, especially if combined with further incoming physical or latent heat, I don't think that is the best news. The N Hem tropical cyclone season is just about to crank into action. GFS also foresees an Atlantic hurricane missing Florida, and beginning a swing north, Again a long shot, but its a sign of the dangers the cooling after summers peak may bring