Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Confusion; Fatigue
Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Company Policy; Human Factors
We were on the OAKES2 arrival to OAK and given direct to MITOE ant an altitude of 3400 feet. Shortly after being issued direct MITOE; we were then cleared the visual approach to RWY 30. Having done this approach in the past; we have been high when crossing MITOE and then have to hurry to get down to make a stabilized approach. At that time; I put in the crossing altitude for MITOE at 2000 feet and started down. Shortly after starting down; the Captain realized that I started the descent too early due to the terrain. I started to level off and that is when the Terrain Alert went off. I executed the terrain avoidance procedure we have been trained to do. We both had the Terrain on ND and there was no indication we were getting close to the ground. There was no yellow or red areas on the map.I was worried about being high at the outer marker and not able to maintain a stabilized approach. Prior to this event; we had flown. I was a little tired and wanting the day to be over.
While cleared for a visual approach to OAK Runway 30; the First Officer started to descend too early and received a terrain alert.