Tropical Storm Dorian is moving toward the west-northwest at 21 mph with the maximum sustained wind speed down to 50 mph. At mid-afternoon Friday, satellite pictures show that the cloud pattern of Dorian is disorganized with little or no sign of the thunderstorms wrapping around the center in a band or bands. The heaviest thunderstorms are offset up to the northeast of the center rather than being wrapped around it.
Dorian will be encountering dry air over the next 24 hours or so and this along with moderate wind shear (winds from the west-southwest that will be blowing across the top of the storm as it moves toward the west). Moderate wind shear should cause some weakening of the storm. Since this wind shear looks like it will hold pretty steady as the storm moves under it, Dorian cold degenerate into a tropical wave over the next couple of days.
There continues to be some issue with the Global Forecast Suite model (GFS) that is being run on a new “super” computer. The GFS is the models that wants to take the storm to the west across the northern parts of the Caribbean Islands, Puerto Rico and Hispaniola and then across the Florida Straits across the Gulf of Mexico and into Texas. As the Bermuda High ridge in the Atlantic that is steering Dorian to the west moves west itself, it would make sense that the track of Dorian would stay low and miss the Florida peninsula. Problem is, how far west does the ridge move and at what point does stop moving with the result being a steering current that would turn Dorian (or Dorian’s remnants)a bit more to the north to near south Florida.
The bottom line is that the storm is still a long way off and will encounter a number of issues (wind shear from the west, slightly cooler water temperatures at places and the presence of some pocket of dry air) that could impact both its intensity and its track. We also have to be aware of fronts that could make it to the east coast and the tendency that might have to nudge the storm offshore if it makes a turn toward the north. There is just too much that can happen with the storm still so far away that could impact where it might go for me to try and forecast/guess whether it heads north up the east coast or west toward the Gulf and Texas. Once the storm gets closer…as in north of the Caribbean Islands (probably next Tuesday) we should
have a much better idea of what to expect. Should the storm make a turn toward the north and move along the east coast of the US (and NC), the track would most likely be in our vicinity sometime next weekend (August 3rd or 4th). Stay tuned!