Small Aircraft
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 80; Flight Crew Total 5000; Flight Crew Type 3500
Time Pressure; Situational Awareness
Conflict NMAC
Flight Crew Requested ATC Assistance / Clarification
Human Factors; Weather
Arriving to OPF on the WAVUN5 [arrival] and leveled off at 6;000 feet a Cessna 182 0r 206 came out of nowhere from a small cloud opposite direction cleared our airplane by a 100 to 150 feet.  We reported it to Miami Center and Miami Approach.
GA pilot on arrival to OPF Airport reported another aircraft appeared from behind a small cloud resulting in an NMAC.