Of course atm Dorian still chugging along, crossing 74W now....
What is the distance between each degree in that area? 64 miles?
If it keeps going West (or WNW) at 8 mph for a while instead of changing to NW, then it will be a fair distance from where it was expected to be and the models will have to adjust unless they respond with an even sharper change to compensate for being further West than expected.