JACKSONVILLE, Fla. – Tropical Depression 15 looked better organized at 5 p.m. Tuesday compared to earlier in the day, with a consolidated, low-level center of rotation, the National Hurricane Center said.
The environmental conditions are expected to remain marginally conducive for slight strengthening during the next 12-18 hours.
Although no longer explicitly forecast, it is still possible that the depression could briefly become a tropical storm later Tuesday night if a burst of deep convection can develop and tighten up the inner-core wind field.
By late Wednesday, however, the combination of a sharp increase in southwesterly vertical wind shear, drier mid-level air and sea surface temperatures less than 26 degrees Celsius should induce steady to rapid weakening, resulting in the cyclone degenerating into a remnant low by 36 hours and dissipating in 72-96 hours.
Regardless of whether the depression becomes a tropical storm before passing near the Cabo Verde islands, the primary threat from this system is the potential for locally heavy rainfall and flash
flooding in those islands.
The depression is expected to produce rainfall accumulations of 1 to 3 inches across the Cabo Verde islands, with isolated maximum amounts of 5 inches in the higher terrain, especially across the eastern portion of the islands. This rainfall may cause flash flooding and mudslides.
At 5 p.m. Tuesday, the center of Tropical Depression 15 was located about 90 miles northeast of the Cabo Verde islands. The depression was moving toward the northwest near 10 mph, and this general motion is expected to continue through Wednesday. On the forecast track, the center of the depression will move across the island of Sal Tuesday evening and over or near the northern Cabo Verde islands Tuesday night and early Wednesday morning.
Satellite-derived wind data indicate that maximum sustained winds remain near 35 mph with higher gusts. Little change in strength is forecast Tuesday night and early Wednesday. Weakening is expected to begin by Wednesday afternoon, and the system is forecast to become a remnant low by Wednesday night or Thursday.
The estimated minimum central pressure is 1007 mb (29.74 inches) is based on observations from the Amilcar Cabral Airport on Sal Island.
The NHC began issuing advisories on the system at 5 p.m. Monday.