Narrative:

ASOS wind instruments do not coincide with the windsock and FAA wind indicators. Their placement on the field allows the actual wind to be disbursed and/or redirected to give the ASOS an inaccurate, (usually wind of less velocity) reading. Therefore, the ATIS winds given to pilots are not the most accurate. Callback conversation with NWS representative revealed the following information: in conversation with a national WX service, (NWS) representative it was revealed that the 'NWS' is responsible for location and installation of 'ASOS' (automated surface observation system). Site location normally supersedes a previous manned or automated site. Prior to commissioning such a site, extensive testing is conducted to assure the accuracy of the information gathered. Additional information: in conversation with an azo tower specialist, it was learned that the location of the 'ASOS' was approximately 500 ft east of runway 17/35, centrally located between B2 and B3. The FAA site is centrally located in the triangle formed by runways 17/35, 5/23 and taxiway east. Of the 2 sites, the 'ASOS' site appeared the more isolated, rendering it free from distorting phenomena.

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Original NASA ASRS Text

Title: AN AZO TRACON CTLR EXPRESSES CONCERN OVER THE DISCREPANCY BTWN WIND VELOCITY READOUTS BTWN THE 'ASOS' AND FAA'S WIND INDICATORS.

Narrative: ASOS WIND INSTS DO NOT COINCIDE WITH THE WINDSOCK AND FAA WIND INDICATORS. THEIR PLACEMENT ON THE FIELD ALLOWS THE ACTUAL WIND TO BE DISBURSED AND/OR REDIRECTED TO GIVE THE ASOS AN INACCURATE, (USUALLY WIND OF LESS VELOCITY) READING. THEREFORE, THE ATIS WINDS GIVEN TO PLTS ARE NOT THE MOST ACCURATE. CALLBACK CONVERSATION WITH NWS REPRESENTATIVE REVEALED THE FOLLOWING INFO: IN CONVERSATION WITH A NATL WX SVC, (NWS) REPRESENTATIVE IT WAS REVEALED THAT THE 'NWS' IS RESPONSIBLE FOR LOCATION AND INSTALLATION OF 'ASOS' (AUTOMATED SURFACE OBSERVATION SYS). SITE LOCATION NORMALLY SUPERSEDES A PREVIOUS MANNED OR AUTOMATED SITE. PRIOR TO COMMISSIONING SUCH A SITE, EXTENSIVE TESTING IS CONDUCTED TO ASSURE THE ACCURACY OF THE INFO GATHERED. ADDITIONAL INFO: IN CONVERSATION WITH AN AZO TWR SPECIALIST, IT WAS LEARNED THAT THE LOCATION OF THE 'ASOS' WAS APPROX 500 FT E OF RWY 17/35, CENTRALLY LOCATED BTWN B2 AND B3. THE FAA SITE IS CENTRALLY LOCATED IN THE TRIANGLE FORMED BY RWYS 17/35, 5/23 AND TXWY E. OF THE 2 SITES, THE 'ASOS' SITE APPEARED THE MORE ISOLATED, RENDERING IT FREE FROM DISTORTING PHENOMENA.

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.