The tropical wave
in the far SW Gulf of Mexico continues to try to organize. This wave has everything going for it EXCEPT an imminent encounter with Mexico. The wave could still become a depression or even a tropical storm upon moving into Mexico Mon. well south of Texas. The system is being steered by a large & strong upper high (3rd image below) across the U.S. into insuring that the system continues west into Mexico.
Meanwhile...the tropical wave over the far Northern Gulf continues to produce t'storms. Again...its short time left over warm water should limit much substantive development as the disturbance moves into Texas by Mon.
And yet another tropical wave is over the Central Caribbean moving west/northwest. No development of this wave is likely through at least the short term.
Check out the very strong upper level high over the nation's midsection which will be a major "driver" of any tropical disturbances in the W. Caribbean & Gulf. The tendency will be for upper level troughing to develop to the east of this big high -- over or near the U.S. east coast -- which would play a role in any tropical disturbance moving west or northwest from the Atlantic.
Large areas of dry mid & upper level air (black & rust colored areas on the water vapor satellite image below) remain over the Central Atlantic. Overall conditions remain unsuitable for significant tropical development in the short term.
Most forecast models continue to point to tropical development in the far Eastern Atlantic during the last few days of Aug. & especially into Sept. The troughing (or possible reinforcement of the trough) or a remaining "pinched" trough in the W. Atlantic might play a role in any possible movement across the Atlantic....or lack thereof.
Shear remains strong over much of the Atlantic Basin -- as can be seen below -- exceeding 30 knots over parts of the Caribbean...exceeding 30 knots over the Central Atlantic...and 50+ knots over the E. Atlantic.
The frequency of tropical waves moving off Africa is increasing but still lacks much organization. While no significant development is likely in the short term, this is an area that could -- & should -- become quite active in the next 1-3 weeks.
Velocity potential anomalies can give us a clue to when there might be an uptick in tropical cyclones.
The map below shows upward vertical velocities (rising air) in the green area – look how nicely this correlates with thunderstorm clusters that can be seen in IR satellite imagery superimposed on the map.
The brown lines represent sinking air which is not as conducive to convection & tropical development.
The large area of positive vertical velocities will gradually spread eastward, & we're already seeing an increase in the vertical velocities over the Central & E. Pacific with tropical development just west of Mexico.
We’re probably looking at about the end of Aug. & first couple weeks or so -- at least -- of Sept. for the Atlantic to become more active.
Speaking of the E. Pacific (& related to the vertical velocities mentioned above)..."Ivo" is moving west of the Baja of California producing heavy rain, gusty winds & rough surf. Moisture from what's left of "Ivo" will spread into the SW U.S. increasing heavy rain & the flooding threat for parts of S. Ca., Az., Utah & NM.