B737 Next Generation Undifferentiated
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action
Weather; Human Factors
Flight was very uneventful on the descent into SJC. We set up and briefed the ILS 12R per the ATIS. While we were being vectored to 12R ATC informed us that they had switched runways and to expect 30L. We had talked about the weather in the area and to have the radar up and to expect changes on the way into SJC. We performed the necessary changes per policy. ATC vectored us onto the ILS and we noticed that the identifier wasn't correct for 30L. We queried ATC. They said that 30L should be active and that they would check on it. We requested to track the LNAV course to the runway anticipating a visual approach and they said that was ok. I had gear down and flaps 15 and was descending to our cleared altitude of 3000' on a proper descent path. Shortly after we confirmed a good ident on ILS 30L. I had a hard time slowing because of the weather and verbalized it to my Captain; we still had time to be stabilized as we were at 1500 ft AGL. I got fully configured at 800 ft on speed and on glide slope when shortly afterward ATC told us 'low altitude alert' and we received a GPWS (Ground Proximity Warning System) 'caution obstacle' warning shortly after ATC's call. We executed a missed approach and came back around uneventfully. Not sure what happened there as I was on glide slope; on speed and we had the correct altimeter setting. I can say I learned to go around when the aircraft wasn't slowing down with gear down and flaps 15. I have seen gusts where this wasn't a factor; but this was too long to slow. I was thinking of the being stabilized gates instead of listening to my gut which was telling me something isn't right here.
B737 flight crew reported receiving a low altitude alert from ATC and a GPWS caution shortly thereafter while on ILS approach to SJC.