Potential Tropical Cyclone Nine still does not have a closed low-level circulation, but is approaching closed to reaching that designation.  Given the observations of sustained winds at time around 40 to 45 mph, once the low-level circulation is established, this PTC is likely to jump to tropical storm strength.

As far as the forecast of the PTC, we still don't know the exact position of the low-level circulation, however if the NHC estimate is accurate then we know a few factors in the forecast.  For one, the track of this tropical low-pressure system is likely to pass near or over the Dominican Republic, Haiti, and Cuba.  Unless there is a significant shift northward of these islands, which is still possible, then this disturbance is likely to run into a lot of disruption of the low-level circulation.  Also, with the tropical low approaching the edge of the western Atlantic ridge and the persistent upper-level trough over the Tennessee River Valley, we know that southwesterly shear will likely increase towards the end of the weekend around the Florida Straits.

What all of this tells me, is that the preliminary idea of keeping this PTC as a tropical storm for the forecast period is the best approach and I agree with the NHC forecast idea.  Beyond Monday, we need to monitor the evolution of the interaction between the western Atlantic ridge and the trough over the Ohio and Tennessee River Valleys.  The southwesterly winds from 850 MB to 200 MB strongly suggests the remnant moisture of this PTC, development or not, will be forced to move up the coast.  How far north will depend on the position of the frontal boundary over the East Coast and the exact orientation of the 500 MB trough to the west.  A more positive orientation would suggest most of the moisture moves off the North Carolina coast while a neutral to negative orientation would bring the bulk of the tropical moisture northwards into the Mid Atlantic and New England.