B737 crew received a GPWS terrain warning to pull up.

Attributes
ACN	502585
Time
Date	200102
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : oak.airport
State Reference	CA
Altitude	msl bound lower : 3350 msl bound upper : 4500
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : o90.tracon
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : vacating altitude
Route In Use	approach : visual arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 153 flight time total : 11700 flight time type : 7170
ASRS Report	502585
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 225 flight time total : 4500 flight time type : 800
ASRS Report	503090
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment : gpws
Resolutory Action	flight crew : took evasive action other
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Weather
Primary Problem	ATC Human Performance

Narrative:

Descending for oakland in IMC, we were on a vector for a left base entry to a runway 11 ILS. The airport was reporting 55 overcast and 10 mi visibility. However, the ceiling was lower to the east and was obscuring the mountain tops. We were descending as cleared to 3200 ft MSL. At about 3350 ft MSL, the GPWS 'terrain, terrain, pull up' warning sounded. The rate of descent at this point was less than 500 FPM. I took the aircraft from the first officer, disconnected the autoplt, increased power and initiated a climb. 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 controller of the deviation. He then cleared us down to 3100 ft MSL. By this time we were in ragged bases and getting good visual ground contact, and from that I could tell we were west of the mountains. Shortly after, we acquired the airport visually and cleared for a visual approach to runway 11. Supplemental information from acn 503090: we contacted approach and told them that we climbed due to the GPWS alert and he said 3200 ft MSL was his MVA. Later he apologized for the alert, and that was it.

Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.