The band of moist, unstable air to its southwest that has been feeding Dorian the past two days is forecast to get cut off on Friday, which will leave the storm isolated in a region with relatively dry, stable air. However, the SHIPS model predicts that wind shear will stay in the low range through Sunday, so there may be no mechanism to drive dry air into the storm to weaken it significantly. Ocean temperatures will begin to rise significantly next two days, reaching 27°C by Friday night and 28°C by Sunday. This increase in water temperature may counteract the more stable air Dorian will be in, allowing the storm to maintain its strength. Given its small size, Dorian is capable of relatively large changes in intensity in a short amount of time, and it would not surprise me if the storm dissipated by the end of the week--or became a Category 1 hurricane.
The official NHC forecast of a tropical storm passing just north of the Lesser Antilles on Sunday is the most likely outcome; the 11 am wind probability forecast from NHC gave Dorian a 25 - 32% chance of being a hurricane at that time. Since Dorian is a small storm, the impacts to the northern Lesser Antilles Islands may be minor, if the core of the storm passes more than 50 miles to the north of the islands, as the official NHC forecast currently anticipates. It currently appears that Dorian will be a potential threat to the Bahama Islands, Bermuda, and the U.S. East Coast next week. There will be a trough of low pressure capable of recurving Dorian out to sea before the storm reaches the Bahamas and U.S., but it is uncertain if this trough will be strong enough to do the trick.
This post was edited on 7/25 at 2:06 pm