ATC specialist claims that the ASOS equipment is reporting inaccurate WX conditions.

Attributes
ACN	342392
Time
Date	199607
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : cys
State Reference	WY
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar pilot : private
Experience	controller non radar : 8
ASRS Report	342392
Person 2
Affiliation	government : faa
Function	oversight : supervisor
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Air Traffic Incident	other
Situations
ATC Facility	other physical facility

Narrative:

During a rain shower at the cys airport, ASOS reported visibility at 2 mi. Prevailing visibility at the time was at least 7 mi. A portion of the heaviest rain moved over the ASOS location generating the false report. I called the NWS office and notified them of the false report. They responded that the ASOS would update the correct visibility during the next speci. Therefore the ASOS reported IFR conditions when none existed and NWS would not correct or augment the observation.

Original NASA ASRS Text

Title: ATC SPECIALIST CLAIMS THAT THE ASOS EQUIP IS RPTING INACCURATE WX CONDITIONS.

Narrative: DURING A RAIN SHOWER AT THE CYS ARPT, ASOS RPTED VISIBILITY AT 2 MI. PREVAILING VISIBILITY AT THE TIME WAS AT LEAST 7 MI. A PORTION OF THE HEAVIEST RAIN MOVED OVER THE ASOS LOCATION GENERATING THE FALSE RPT. I CALLED THE NWS OFFICE AND NOTIFIED THEM OF THE FALSE RPT. THEY RESPONDED THAT THE ASOS WOULD UPDATE THE CORRECT VISIBILITY DURING THE NEXT SPECI. THEREFORE THE ASOS RPTED IFR CONDITIONS WHEN NONE EXISTED AND NWS WOULD NOT CORRECT OR AUGMENT THE OBSERVATION.

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.