Tropical depression #4
has formed in the E. Atlantic from a strong tropical wave that moved off the coast of Africa over the weekend. Maps below show the pitfalls ahead for the depression though it's quite possible the depression will manage to become tropical storm "Dorian". Even so a huge slug of very dry mid & upper level air is ahead over the Central Atlantic -- see the water vapor image -- 5th image below. The rust color is extremely dry air. The next image shows sea surface temps. which are a bit marginal -- though not prohibitive -- for sustenance of a tropical cyclone -- near 80 degrees. Lastly....while in a low shear environment for the moment, wind shear picks up dramatically over the Central Atlantic between Puerto Rico & about 45 degrees W (see last image below). Indeed...global forecast models are not at all enthusiastic about this system & most models weaken #4 to an open wave by the weekend. At this point, the NHC maintains a weak tropical storm to northeast of Puerto Rico by early next week. An upper level trough looks to be over the Western Atlantic next week (where there is a trough now - see 4th image below) which would probably continue at least some shear & also encourage a northwest or north turn (with the strong Bermuda high fairly far to the east/northeast over the Atlantic). The shallow (weak) nature of the system should allow the system to move along quickly...possibly steered more the low level winds vs. mid/upper level flow....unless there is more strengthening than I currently expect.
So....at this point....it would appear that t.d. #4 will remain weak & move quite rapidly to the west/northwest. IF there were to be any effects on the First Coast, it would be the middle of next week & these effects -- right now
-- would appear to be minor.