Ed, 1 deg further north than forecast makes it more likely to go out to sea, as it "feels" the weakness in the ridge and ultimately is captured by the midlatitude zonal flow across the eastern US. Given the way the midlatitude pattern has evolved over the western US, with a shortwave moving from Oregon into Idaho now and a larger trough beginning to dive southward out of British Columbia and Alberta, it is becoming more likely that the pattern amplifies slightly, a shortwave trough captures Irene, and the storm does not make a "full" landfall. Being further north makes it more likely that the storm would feel the effects of such a trough...and gives the ridge less room to build back in. Nevertheless, the track will still likely be too close to the coast for comfort...and any prolonged movement back towards the west -- i.e. 12hr of movement instead of wobbles or reorganization -- will increase the risk to the coastline yet again.