Between August 24 and September 7, 2019, the National Hurricane Center published 60 forecast advisories on Hurricane Dorian. Here's a look at how those forecasts stacked up against the actual path the storm took. Shown in blue are the official forecast tracks, while the actual path the center of the storm took is shown in black.
What you can see is that most of the time the actual track (in black) was within the forecast cone. The periods of greatest uncertainty occurred as the storm passed by Puerto Rico and again as it passed over the Bahamas.
Once Dorian passed the Bahamas and started meandering northward, the forecast honed in on a track taking the storm just off the South Carolina coast. From this point on, the forecast remained remarkably consistent. Shown below in red are the official forecast tracks compared with the storm's actual path in black.
The takeaway is that the official NHC forecast is the most important forecast to pay attention to. It consistently outperforms individual computer models. It's also important to understand that the forecast cone shows where the center of a storm could be in the future. Dorian is a good example of a storm that did not always follow the path along the center of the cone.
Another important takeaway is that while NHC forecasters are skilled at making 3-day predictions, their four and five day predictions are noticeably less accurate. In the map below, prediction locations made four and five days out are shown in orange and red. Notice how the orange and red dots deviate the most from the path the storm actually took. The numbers in the circles represent how many hours in the future that predicted location is for.