Small Transport
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors
Approaching JHW; we were assigned to cross OYNEM intersection at 4000'; then afterwards we were cleared for the (RNAV/GPS 25) approach. Also; we were notified of traffic at our 12 o'clock; 500' above us and descending. Just prior to crossing OYNEM; we broke out of the clouds and began looking for traffic; as well as descending to 3800'. The traffic continued towards us and descended. Within a moment; the TCAS advised us to descend. I disconnected the autopilot and began a descent. Within seconds; we both saw the light single a few hundred feet above us in a turn to his left. We advised Buffalo of the RA and continued the approach and landed uneventfully.Onboard safety systems (TCAS) advised us of conflicting traffic.I disconnected the autopilot and began a descent; at least 200 feet below my next minimum altitude of 3800'.As a crew; I believe we functioned correctly; both in identifying the conflicting traffic and the subsequent compliance with the TCAS RA. We were on an IFR flight plan near messy thunderstorms; so I can't conclude what the traffic was doing at that exact location. [Aircraft Y] did not appear to be on an IFR flight plan. TCAS is the valuable solution here and we'll continue to utilize this onboard tool.
Fractional Captain reported an NMAC occurred on arrival into JHW.