Medium Large Transport
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human-Machine Interface; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Weather / Turbulence
Flight Crew FLC Overrode Automation
Airspace Structure; Procedure; Human Factors; Company Policy; Chart Or Publication
The flight was BOI and crossed a strong cold front that included moderate turbulence and a strong tailwind. The autopilot disconnected around 18000 ft. due to turbulence and I elected to fly the rest of the STAR by hand. ATIS was reporting visual approaches and we requested the Visual via an RNAV Approach ground track. We broke out and had the field in sight.  My First Officer commented 'isn't this where everyone gets a GPWS warning?'  I replied; 'yes; we're supposed to turn inside the base ground track.' Then I didn't. I started the turn as if I were flying the RNAV approach and combined with a strong tailwind; received a solid yellow terrain caution and the aural 'Pull Up' warning. I had the field and terrain in sight and increased my bank angle to the 'inside of the base ground track' and rejoined the approach guidance on final.We talked about the night visual guidance for this airport on the ground. It says to follow the approach guidance to the runways L/R. Fat; dumb; and happy; I did not catch that the RNAV Approach for the rightis still NOTAM'd out of service by Company until reviewing the data for this ASAP. I feel like an idiot. I humbly submit the following recommendation expecting that 99% of Company pilots won't need it. Change the Night Visual Approach Guidance for this airport in the Aeronautical Information Circular to read 'Authorized with the following additional restrictions. Follow instrument approach procedure or radar vectors to VGSI. RNAV Approach IS out of service due to terrain cautions.
An Air Carrier Captain conducting a night time visual approach reported receiving a Terrain Warning due to not following Company guidelines but continued the approach.