another quote from weather.com
Prognosis for development
There is an upper-level trough to the west and northwest of this tropical wave. Associated with this trough are two ingredients that are typically harmful to tropical cyclone development:
- Wind shear: In this case, west to southwest winds aloft are present to the north of Hispanola, Puerto Rico, and the Virgin Islands. Given near-surface winds have an easterly component, this wind shear tends to displace thunderstorms away from any low-level circulation. For tropical cyclogenesis, you want thunderstorms concentrated near an area of surface low pressure.
- Dry air: You can see this tongue of dry air in the water-vapor satellite image below as a brown-shaded patch over the Bahamas, just east of Miami.