I noticed the same fast moving Wave catching or phasing with the more western Wave. I'm not particularly impressed by the system other than it's persistant convection. The area appears on IR imagery to be 'riding the wave' on the SW edge of the SAL dust cloud. Similar to a reverse Bow Echo or the letter C.
Example- ,C (the comma is the system and C is the SAL)

NHC has bumped the formation possibility up to 60% as of 8 AM EDT this morning. But they are calling the system nearly stationary. ( Stationary usually means movement less than 7 mph in NWS terms )