Stormy Gulf... Upper Trough Takes Shape East of Bahamas... "Erick" Just Off Pacific Mexican Coast
Thunderstorms remain active across the Gulf but with no organization. This pattern will persist but no surface development is evident nor is expected with the possible exception of the extreme Western Gulf or Bay of Campeche. Any development in these areas would be slow & steered north then west.
The TUTT low that I've been posting about the last few days -- & as indicated by forecast models -- is nicely taking shape to the east of the Bahamas with convection flaring in its vicinity. While models continue to show no surface development, this is a feature to watch closely as it barrels to the west.
This upper level disturbance became pinched off from a strong upper level trough over the Central Atlantic. The parent trough has lifted quickly to the north & east while the feature left behind will now accelerate to the west underneath (or south of) a strong upper level & surface high pressure over the Central & Western Atlantic. This so-called TUTT - tropical upper tropospheric trough - will have a cold core at first & move to the west reaching Fl. Mon. night-Tue. By this time, the upper trough looks like it's core temp. will be more neutral. In any case....surface development is not indicated by forecast models & is not likely to occur as the system will be fast moving & in a pretty high shear environment. Subsidence on the west side of the TUTT will limit thunderstorms over the First Coast -- & much of Fl. -- Sun.-Mon. But on the east side of the trough, the air will be more unstable accompanied by an increase in vertical velocities (lift) & upper level diffluence which should increase t'storms Tue.-Wed. across the local area & much of Fl. Penn State's College of Earth & Mineral Sciences offers a very detailed discussion of TUTT's - click ** here
In the E. Pacific, "Dalila" is quickly fading well to the S/SW of the Baja but "Erick" is strengthening just off the coast of Mexico south of Acapulco. "Erick" will bring heavy rain, gusty winds & dangerous sea/surf to Acapulco & coastal Mexico to the south while staying just offshore. A building upper level ridge of high pressure should start to push "Erick" more to the west -- away from Mexico -- over the weekend.