其實NHC已經評Low一段時間囉
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN AUG 10 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. A tropical wave accompanied by a broad low pressure system is
located about midway between the west coast of Africa and the Cape
Verde Islands. This disturbance is producing a large area of
cloudiness and disorganized showers and thunderstorms, and some slow
development of this system is possible over the next several days
while it moves westward at 15 to 20 mph.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...medium...30 percent.