Tropical Storm "Dorian" Forms in the E. Atlantic....
Tropical depression #4
has become tropical storm "Dorian" in the E. Atlantic originating as a relatively early season strong tropical wave that moved off the coast of Africa over the weekend. Maps below show the pitfalls ahead for "Dorian" including:
** 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 before sea surface temps. again increase.
** 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 "Dorian" 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 (roughly where there is a trough now - see 4th satellite image below) which would probably continue/reinforce shear & also encourage a northwest or north turn (with the strong Bermuda high fairly far to the east/northeast over the Atlantic) in the long term. The shallow (weak) nature of the system should allow the system to move along quickly...possibly steered more by 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 "Dorian" will remain relatively 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.
It should be emphasized that it's still early in the forecast on this storm, & the American GFS model last week was showing a stronger tropical cyclone near Puerto Rico, so it's too early to completely write off "Dorian" & how strong it might -- or might not -- become....as well as the track next week once closer to the Caribbean & SW Atlantic.
Forecast models plot below courtesy S. Fl. Water Management District (excellent agreement into early next week)....ultimate forecast will hinge on the trough remaining near the east coast which would tend to cause recurvature -- to at least some degree -- ... & whether or not "Dorian" can survive the generally hostile environment it will encounter the next several days.