Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Conflict NMAC
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action
Airspace Structure; Procedure; Human Factors
Descending into ZZZ while on a vector to final ATC advised us of VFR traffic at our 12 o'clock position. We thought we could see the traffic just before it entered a cloud that we were about to fly over and had verified the traffic on TCAS. The aircraft was climbing; and when it was about 200' below us we received a CLIMBING TCAS RA. CA Smith who was flying at the time took evasive action in compliance with the TCAS RA. I notified ATC of the response action; and we returned to normal flight moments later.[This event was caused by] another pilot [who] chose to operate his/her aircraft in clouds without a clearance.Aircraft within close proximity to Class C airspace should be required to be in contact with a controller at all times.
Approach informed us that we could deviate as necessary to avoid traffic.
An arriving CRJ-700 flight crew experienced an NMAC with a VFR aircraft operating in IMC just outside their destination airport's Class C.