The western lobe near 10N/30W is certainly the more convectively active of the two. Wish we could get an ASCAT pass over it (I hear one should be coming up soon). A very recent pass shows the low the NHC has for the center further east:
However, vorticity is on the increase for the area further to the west, as well as surface convergence. The GFS has consistently shown the two areas merging in the next 36 hours, but it has more noticeably shown this area absorbing the area further east for its last two runs. I don't know any of the implications of this change; just interesting.
Tropical Weather Outlook NWS National Hurricane Center Miami FL 200 AM EDT Fri Aug 4 2017
For the North Atlantic...Caribbean Sea and the Gulf of Mexico:
1. A large and complex area of disturbed weather, associated with a broad low pressure system, extends from about 400 miles south of the Cabo Verde Islands to about 600 miles southwest of the Cabo Verde Islands. Environmental conditions are forecast to be conducive for gradual consolidation and development, and a tropical depression is likely to form by early next week over the eastern or central tropical Atlantic Ocean. This system is forecast to move toward the west or west-northwest at 10 to 15 mph for the next several days. * Formation chance through 48 hours...medium...40 percent. * Formation chance through 5 days...high...80 percent.