Date: 202103
Local time of day: 1201-1800
Location: SAN.Airport, CA
Weather elements / visibility: Cloudy
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing
Airspace: Class B SAN
ATC / advisory: Tower SAN
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Time Pressure
Second reporter function: Captain; Pilot Flying
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach
Detector: Automation Aircraft Terrain Warning
Result: Flight Crew Landed As Precaution
Contributing factors: Weather; Human Factors
Primary problem: Human Factors

Narrative: Visual to 27 at SAN using RNAV Z. Ceiling was BKN015. Crew briefed visual procedures at altitude but was informed that ATIS had changed late in the descent; crew adjusted minimums to account for the updated ceiling. Earlier I had queried the Captain if he preferred flaps 40 for SAN and he said he wanted flaps 30. Vref was 141 knots; wind component added 6 knots for a VTARGET of 147 knots. Captain configured early and we were stable at 1;000 feet AGL with a slightly high VVI (Vertical Velocity Indicator) due to SAN Runway 27 3.5 degree approach and the high weight and subsequent high approach speed.  We were visual at that point; I think we broke out at 1;000-1;200 feet. Every time I crosschecked the speed and VVI; the Captain was stable; with the knowledge that the 3.5 degree approach and speed (as mentioned in the Safety Alert) would result in VVI rates over 1;000 feet. I was crosschecking radar altitudes and glideslope guidance more than I usually do; but this is my personal habit for SAN. As I did the normal 'in and out' visual crosscheck; nothing seemed amiss. Directly over or slightly after the parking deck on short final; the Captain slightly adjusted his visual aim point as is common technique at SAN. My eyes were outside at this point. We both heard a 'sink rate...'. I don't know what the second phrase was; as the Captain acknowledged the first sink rate forcefully and almost instantly. I quickly looked inside and I think I saw 'pull up' on the bottom of the PFD for what seemed like an instant. I can't be certain; however; and it can't be understated how fast it went away if indeed it was there. I looked back up and we were two red and two white on the PAPI; slightly fast; and Captain was in what looked like a good position to land. We made a safe landing and applied moderate braking and exited the runway. In the postflight; the Captain and I disagreed about what the second term was at the aural system annunciated. He thinks he heard 'sink rate; sink rate.' I actually don't know what the second term the aural system annunciated was; as I didn't hear it clearly due to the Captain's acknowledgment of it. I do think I saw a very fleeting 'pull up' on the PFD; but I can't be perfectly certain; and Captain is adamant that we didn't get the GPWS warning; only the sink rate caution. I want to be clear that I understand the limitation with regard to the warning annunciator. In hindsight; I can see now that a go-around could have been a prudent decision even though the aircraft appeared to be a safe and normal position for short final at SAN. I want to highlight this issue for a few reasons. It bears repeating that phase of flight; temporal distortion; and flight deck confusion can all conspire to create a situation where two trained and alert crew members can see different things. The other thing I want to highlight is how heavy -800's; going into SAN; can potentially be affected by a flaps 30 approach. I don't know why we don't have recommended flap settings for certain situations. We've all been flying light aircraft for almost a year now and perhaps it would help to remind crews about heavy aircraft with higher approach airspeeds and subsequently higher VVIs in higher altitude environments or steeper approaches like SAN.


Second narrative: On approach to SAN when transitioning outside; we briefly received a sink rate call. At the gate; the First Officer was unsure if it was just a sink rate call or sink rate pull up. I adjusted sink rate and landed normally.


Synopsis: B737-800 Flight Crew reported on an unstable approach receiving two cautionary messages the were missed by flight crew.