A B737-700 flight crew reported an egpws predictive windshear warning (pws) while on short final for...

Narrative:

At 500 ft AGL on final to runway 12L in stl; we received a pws warning (go around...windshear ahead). The weather at the time was partly cloudy with no convective activity in the area. Approximately five seconds after receiving the pws warning; the weather radar went into test mode. The pilot not flying and I briefly discussed the situation and I made the decision to land with no objection from the pilot not flying. After parking at the gate; I called for the maintenance person at stl and described to him what had happened. He stated that this was a common occurrence at stl and there was nothing wrong with the aircraft so no logbook entry was made. The maintenance person stated this was a known problem and 'they' (I don't know who 'they' are) recently flew an aircraft around stl to try and isolate the cause of the erroneous pws warnings; but were unable to find the cause.

Original NASA ASRS Text

Title: A B737-700 flight crew reported an EGPWS Predictive Windshear Warning (PWS) while on short final for STL Runway 12L; but because daylight VMC conditions existed without convective activity; the approach was continued.

Narrative: At 500 FT AGL on final to Runway 12L in STL; we received a PWS warning (GO AROUND...WINDSHEAR AHEAD). The weather at the time was partly cloudy with no convective activity in the area. Approximately five seconds after receiving the PWS warning; the weather radar went into test mode. The pilot not flying and I briefly discussed the situation and I made the decision to land with no objection from the pilot not flying. After parking at the gate; I called for the Maintenance person at STL and described to him what had happened. He stated that this was a common occurrence at STL and there was nothing wrong with the aircraft so no logbook entry was made. The Maintenance person stated this was a known problem and 'they' (I don't know who 'they' are) recently flew an aircraft around STL to try and isolate the cause of the erroneous PWS warnings; but were unable to find the cause.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1088739
Time
Date	201305
Local Time Of Day	0601-1200
Place
Locale Reference	STL.Airport
State Reference	MO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Component
Aircraft Component	GPWS
Person 1
Function	Pilot Flying Captain
Experience	Flight Crew Last 90 Days 218 Flight Crew Type 12500
Person 2
Function	First Officer Pilot Not Flying
Experience	Flight Crew Last 90 Days 126
Events
Anomaly	Aircraft Equipment Problem Less Severe

A B737-700 flight crew reported an egpws predictive windshear warning (pws) while on short final for stl runway 12L; but because daylight VMC conditions existed without convective activity; the approach was continued.