AN ACR MLG HAD A FALSE GPWS WARNING.

Narrative

TSTMS WERE IN THE AREA AND RAIN WAS FALLING AT TIME OF TKOF FROM RWY 8L. WE WERE CLRED FOR TKOF AND DIRECTED TO TURN TO 065 DEG HDG AFTER TKOF. A NORMAL MAX PWR TKOF WAS ACCOMPLISHED FROM RWY 8L. SHORTLY AFTER RETRACTING FLAPS ON HDG 065 DEGS; WE ENTERED HVY RAIN/TURB. AT APPROX 8500 FT MSL; THE ACFT'S GPWS SOUNDED; INDICATING TERRAIN AND STATING 'PULL UP; PULL UP.' THE CAPT IMMEDIATELY APPLIED COMPANY PROC'S MAX PWR AND ROTATED TO 15 DEGS NOSE HIGH. ALTHOUGH THE ALTIMETER WAS INDICATING A CLB SIT; THE RADAR ALTIMETER WAS DECREASING INDICATING CLOSURE WITH TERRAIN. DUE TO THE NOISE LEVEL FROM THE RAIN AND THE GPWS; COM BOTH INSIDE AND OUTSIDE THE COCKPIT WAS EXTREMELY DIFFICULT. DURING THIS SIT WE EXCEEDED OUR CLRNC ALT OF 10000 FT MSL. BY THE TIME THE GPWS WARNINGS HAD CEASED AND WE HAD LEVELED OFF; WE WERE AT 12500 FT MSL. DEN DEP WAS NOTIFIED OF OUR DEV AND WE WERE DIRECTED TO CLB TO 13000 FT MSL. IN HINDSIGHT; IT APPEARS THAT WE HAD EXPERIENCED A FAILURE IN THE GPWS SYS WITH A FALSE TERRAIN INDICATION. DUE TO THE IFR/RAIN CONDITIONS; WE WERE NOT ABLE TO IMMEDIATELY IDENT THIS.