Of the 22 systems since 1980 to pass within 100 miles of the British Virgin Islands in September, 5 made landfall in the us (22%). This feels like a reasonable benchmark based on model consensus, although as Wxwatcher007 says above, there is a high degree of uncertainty until a LLC develops. I think odds of this system never developing at all have gone up this morning with lots of shear potentially across the Carribean.