B737 captain reports not being able to detect obvious thunderstorms on the aircraft radar. The storm...

Narrative:

During day VMC thunderstorm deviations; we were having a difficult time getting proper radar returns for weather that was clearly visible. Only after we were through deviating did I discover the gain on the weather radar was just out of the auto position; resulting in a min gain setting. The real issue; and the reason for the report; is that the cal indication on the map display showing the gain was in man was masked by the airports also being displayed. The font and color of the two are nearly identical; making identification of the gain setting easily missed/masked. The hazards of being in min gain and not knowing are self-evident. The font and/or color of the radar status should be modified so as not resemble that of the airports on the map display.

Original NASA ASRS Text

Title: B737 Captain reports not being able to detect obvious thunderstorms on the aircraft radar. The storms are avoided visually and it is later discovered that the gain is set to MIN instead of Auto.

Narrative: During day VMC thunderstorm deviations; we were having a difficult time getting proper radar returns for weather that was clearly visible. Only after we were through deviating did I discover the GAIN on the weather radar was just out of the auto position; resulting in a MIN GAIN setting. The real issue; and the reason for the report; is that the CAL indication on the Map Display showing the GAIN was in MAN was masked by the airports also being displayed. The font and color of the two are nearly identical; making identification of the GAIN setting easily missed/masked. The hazards of being in MIN GAIN and not knowing are self-evident. The font and/or color of the radar status should be modified so as not resemble that of the airports on the map display.

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	1125516
Time
Date	201308
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Weather Radar
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural Published Material / Policy

B737 captain reports not being able to detect obvious thunderstorms on the aircraft radar. The storms are avoided visually and it is later discovered that the gain is set to min instead of auto.