Narrative:

Our ASOS was reporting the visibility at 3/4 of a mile. The pilot of aircraft X reported the airport in sight and I cleared him for the visual approach. The pilot reported the airport in sight somewhere around 20 NM from the field. Tower had called earlier to tell me that the fog that was reported via the ASOS was sitting on the approach end of runway 21 which is where the ASOS equipment is. I knew that most of the airport was clear but the ASOS wasn't reporting it and the tower hadn't augmented it. Tower told me over the line that he was on the visual and that he couldn't be on the visual because the weather wasn't VFR. Tower then cleared the aircraft on the GPS runway 17. The aircraft landed without incident. The next aircraft in was aircraft Y. I was vectoring him for a GPS because the weather was still being reported below VFR. I was told that I could give a contact approach; I was unsure but I gave it anyway after the pilot asked for it. The ASOS was still reporting the visibility at 3/4 of a mile. Again the aircraft landed without incident. I've refreshed myself with the 7110.65. I know that the weather has to be VFR for a visual approach. I also know that the reported ground visibility has to be 1 statute mile for a contact approach. I think we may have had these things but the weather hadn't been augmented in the ASOS. Recommendation; I'm not sure there are any. I've already re-read the 7110.65 on both of these issues to refresh myself. Also had tower augmented the ASOS we would have been VFR and this wouldn't have been an issue.

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Original NASA ASRS Text

Title: ROW Controller issued a visual approach clearance followed by a contact approach clearance to successive arrivals when the official weather was below minimums for both types of procedures.

Narrative: Our ASOS was reporting the visibility at 3/4 of a mile. The pilot of Aircraft X reported the airport in sight and I cleared him for the visual approach. The pilot reported the airport in sight somewhere around 20 NM from the field. Tower had called earlier to tell me that the fog that was reported via the ASOS was sitting on the approach end of Runway 21 which is where the ASOS equipment is. I knew that most of the airport was clear but the ASOS wasn't reporting it and the Tower hadn't augmented it. Tower told me over the line that he was on the visual and that he couldn't be on the visual because the weather wasn't VFR. Tower then cleared the aircraft on the GPS Runway 17. The aircraft landed without incident. The next aircraft in was Aircraft Y. I was vectoring him for a GPS because the weather was still being reported below VFR. I was told that I could give a contact approach; I was unsure but I gave it anyway after the pilot asked for it. The ASOS was still reporting the visibility at 3/4 of a mile. Again the aircraft landed without incident. I've refreshed myself with the 7110.65. I know that the weather has to be VFR for a visual approach. I also know that the reported ground visibility has to be 1 statute mile for a contact approach. I think we may have had these things but the weather hadn't been augmented in the ASOS. Recommendation; I'm not sure there are any. I've already re-read the 7110.65 on both of these issues to refresh myself. Also had Tower augmented the ASOS we would have been VFR and this wouldn't have been an issue.

Data retrieved from NASA's ASRS site as of April 2012 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.