B737 CREW RECEIVED A GPWS TERRAIN WARNING TO PULL UP.

Narrative

DSNDING FOR OAKLAND IN IMC; WE WERE ON A VECTOR FOR A L BASE ENTRY TO A RWY 11 ILS. THE ARPT WAS RPTING 55 OVCST AND 10 MI VISIBILITY. HOWEVER; THE CEILING WAS LOWER TO THE E AND WAS OBSCURING THE MOUNTAIN TOPS. WE WERE DSNDING AS CLRED TO 3200 FT MSL. AT ABOUT 3350 FT MSL; THE GPWS 'TERRAIN; TERRAIN; PULL UP' WARNING SOUNDED. THE RATE OF DSCNT AT THIS POINT WAS LESS THAN 500 FPM. I TOOK THE ACFT FROM THE FO; DISCONNECTED THE AUTOPLT; INCREASED PWR AND INITIATED A CLB. THE RADIO ALTIMETER SHOWED 1280 FT AGL WHEN I STARTED THE RECOVERY. THE WARNING SILENCED ALMOST IMMEDIATELY AFTER STARTING THE RECOVERY. I LEVELED AT 4500 FT MSL AND NOTIFIED THE CTLR OF THE DEV. HE THEN CLRED US DOWN TO 3100 FT MSL. BY THIS TIME WE WERE IN RAGGED BASES AND GETTING GOOD VISUAL GND CONTACT; AND FROM THAT I COULD TELL WE WERE W OF THE MOUNTAINS. SHORTLY AFTER; WE ACQUIRED THE ARPT VISUALLY AND CLRED FOR A VISUAL APCH TO RWY 11. SUPPLEMENTAL INFO FROM ACN 503090: WE CONTACTED APCH AND TOLD THEM THAT WE CLBED DUE TO THE GPWS ALERT AND HE SAID 3200 FT MSL WAS HIS MVA. LATER HE APOLOGIZED FOR THE ALERT; AND THAT WAS IT.