this is something of interest. seems the gfs and cmc shows something with this wave in it's future.
...TROPICAL WAVES... TROPICAL WAVE IS ALONG 27W/28W S OF 18N MOVING W 15 KT. BROADENING LOW LEVEL INVERTED-V SIGNATURE IS OBSERVED ON SATELLITE IMAGERY W OF THE CAPE VERDE ISLANDS. ISOLATED SHOWERS ARE WITHIN 75 NM OF THE WAVE AXIS EMBEDDED WITHIN THE ITCZ.