Narrative:

Planned a short flight local to mgy. I checked a computerized progress chart and noticed an approaching front with some associated WX activity. I contacted the day FSS for an abbreviated briefing. My main concern was when the front would enter our area. I was told it would not become a factor until much later that afternoon. No mention was made of less than VFR visibility during this briefing and personal observation during my drive to the airport indicated a typical hot, hazy summer morning, with little or no clouds. After preflting the aircraft, I started the engine and tuned in the automated WX reporting system (118.375 MHZ) on the field to make a final check of winds and altimeter setting. I was surprised to find the reported visibility to be only 4 mi, but since this was above VFR minimums, I continued with my taxi, runup and takeoff. Immediately after liftoff, I realized that the visibility aloft was lower than I had expected. While I could see a microwave tower about 3 mi away that is commonly used at our airport to determine VFR minimums, I felt the WX to be below my 'personal minimums,' so I remained in the pattern, and during my downwind leg, tuned in the ATIS for day, about 15 mi to the north. I discovered that they were calling the visibility 2 1/2 mi in haze. I proceeded downwind and completed a normal, uneventful landing to a full stop. In retrospect, I realize that I had fixated on determining the status of the approaching cold front and had neglected to gather other appropriate WX information, such as the current or forecast visibility. I allowed myself to be fooled by what appeared to be clear skies. This will be avoided in the future by reviewing the entire WX picture and not concentrating on just 1 aspect of it.

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Original NASA ASRS Text

Title: PVT PLT OF A C172 TOOK OFF FROM A NON CTLED ARPT AND FLEW AROUND THE TFC PATTERN WHEN THE RPTING WX INDICATED BELOW VFR MINIMUMS.

Narrative: PLANNED A SHORT FLT LCL TO MGY. I CHKED A COMPUTERIZED PROGRESS CHART AND NOTICED AN APCHING FRONT WITH SOME ASSOCIATED WX ACTIVITY. I CONTACTED THE DAY FSS FOR AN ABBREVIATED BRIEFING. MY MAIN CONCERN WAS WHEN THE FRONT WOULD ENTER OUR AREA. I WAS TOLD IT WOULD NOT BECOME A FACTOR UNTIL MUCH LATER THAT AFTERNOON. NO MENTION WAS MADE OF LESS THAN VFR VISIBILITY DURING THIS BRIEFING AND PERSONAL OBSERVATION DURING MY DRIVE TO THE ARPT INDICATED A TYPICAL HOT, HAZY SUMMER MORNING, WITH LITTLE OR NO CLOUDS. AFTER PREFLTING THE ACFT, I STARTED THE ENG AND TUNED IN THE AUTOMATED WX RPTING SYS (118.375 MHZ) ON THE FIELD TO MAKE A FINAL CHK OF WINDS AND ALTIMETER SETTING. I WAS SURPRISED TO FIND THE RPTED VISIBILITY TO BE ONLY 4 MI, BUT SINCE THIS WAS ABOVE VFR MINIMUMS, I CONTINUED WITH MY TAXI, RUNUP AND TKOF. IMMEDIATELY AFTER LIFTOFF, I REALIZED THAT THE VISIBILITY ALOFT WAS LOWER THAN I HAD EXPECTED. WHILE I COULD SEE A MICROWAVE TWR ABOUT 3 MI AWAY THAT IS COMMONLY USED AT OUR ARPT TO DETERMINE VFR MINIMUMS, I FELT THE WX TO BE BELOW MY 'PERSONAL MINIMUMS,' SO I REMAINED IN THE PATTERN, AND DURING MY DOWNWIND LEG, TUNED IN THE ATIS FOR DAY, ABOUT 15 MI TO THE N. I DISCOVERED THAT THEY WERE CALLING THE VISIBILITY 2 1/2 MI IN HAZE. I PROCEEDED DOWNWIND AND COMPLETED A NORMAL, UNEVENTFUL LNDG TO A FULL STOP. IN RETROSPECT, I REALIZE THAT I HAD FIXATED ON DETERMINING THE STATUS OF THE APCHING COLD FRONT AND HAD NEGLECTED TO GATHER OTHER APPROPRIATE WX INFO, SUCH AS THE CURRENT OR FORECAST VISIBILITY. I ALLOWED MYSELF TO BE FOOLED BY WHAT APPEARED TO BE CLR SKIES. THIS WILL BE AVOIDED IN THE FUTURE BY REVIEWING THE ENTIRE WX PICTURE AND NOT CONCENTRATING ON JUST 1 ASPECT OF IT.

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.