Friday, August 31, 2018 3:43 PM

Tropical Troubles For Gulf?

Christopher Nunley

Saturday Morning Update:
The NHC has given this tropical wave a 40% chance to develop over the next five days.

Friday Evening Update:
The tropics may begin to heat up “close to home” next week as a tropical wave eventually encounters more favorable conditions for intensification. Currently, the tropical wave is sitting south and east of Florida (near the island of Hispaniola) and has a 10% chance of development over the next five days according to the National Hurricane Center (see Fig. 1).

Fig. 1: NHC monitoring tropical wave
The tropical wave will move north and westward into the eastern Gulf of Mexico by early next week. At this point, the tropical wave may begin to organize and intensify into a tropical cyclone. Wind shear is currently preventing organization (see Fig. 2) but this should lessen by mid next week across the Gulf (see Fig. 3). Numerical guidance is struggling with the evolution and movement of the tropical wave. The European is currently stronger and shows the wave intensifying potentially into a tropical cyclone (see Fig. 4). The GFS, however, keeps this as an open wave. The strength will play a role in the movement of the wave. An open wave would likely track towards the northwestern Gulf whereas a tropical cyclone would likely move towards the north-central Gulf.

Fig. 2: Current wind shear (Friday)

Fig. 3: Future wind shear (Wednesday morning)

Fig. 4: European 850mb winds (Wednesday morning)
Regardless of intensity, tropical moisture will aid in heavy rainfall for much of the Gulf. Heavy rainfall and gusty winds will impact parts of Florida as soon as this holiday weekend followed by rain chances increasing for the northeast and north-central Gulf by early to mid next week. Several inches are possible across the northern Gulf next week (see Fig. 5).

Fig. 5: 7-day rainfall totals
This tropical wave needs to be closely monitored over the weekend. Updates on potential track and intensity will be provided as uncertainty decreases.