Date: 201507
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: Mixed
Weather elements / visibility: Rain; 5
Light: Daylight
Aircraft: PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Initial Approach
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Personal
Reporter function: Instructor; Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Human factors: Situational Awareness
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: ATC Equipment / Nav Facility / Buildings; Chart Or Publication; Weather
Primary problem: Chart Or Publication

Narrative: I was on an IFR flight plan that I filed from the air. At the time I was deciding between landing at a local airport that was marginal VFR but had a stationary thunderstorm within 20 NM of the airport; or continuing up 200 NM north of my position to an airport that was familiar but not ultimately very close to my final destination. There was a large stationary front with a big radar return over most of geographic area; ranging at least in 200-250 NM in diameter. It was slow moving with mostly green radar returns along my preferred destination. I chose an airport that was behind any radar return and had high ceilings. I had plenty of fuel (5 hours) and the weather was reporting IFR; but the ceilings were staying well within my comfort zone. I usually prefer not to fly approaches unless I have a 1000 ft ceiling; for safety. But the METAR was reporting 900 feet broken and overcast at my destination which is within my personal limits so I continued on to my destination. I was watching the huge cell move to the north and east in a slow direction (away from my destination). As I continued to watch the radar as I got closer to my destination; I continued to scan and listen to all ATIS/AWOS/ASOS reports in a 50 NM area as the stations came into listening distance. I took a screenshot of all the METARs of airports within 50 NM of my landing; and of the 9 that showed up; 4 were marginal VFR; 4 were IFR with ceilings of 800/900 and one was low IFR about 60 NM to the west. I have some familiarity with the airport and location I was flying to. However; I picked this particular destination because of a GPS approach and because of the higher ceilings at this airport than the surrounding areas. In truth; this destination was still about 1 hour flying time than the destination I really wanted. But; it was at the tail end of the radar returns which had moved away by the time I was ready to fly the approach. I was overly concerned about the radar return (which was all colored Green; not yellow or red) and took little interest in the satellite picture. In my opinion; I safely chose the best field and weather conditions as possible that were legal. As a CFI/Commercial pilot that flies mainly for pleasure; I was not in a hurry that day nor did I need to make any destination (as I obviously was self-deviating to a better airport than my home airport). However; I believe I was lulled into a false sense of security by continually trying to get new information from my radar/ASOS/ATIS and other tools.The airport I chose did not have its own METAR/AWOS. Instead; I was using the AWOS for a field approximately 8 NM west away as per the instrument approach chart. Minutes from final approach; the ASOS reported 900 ft ceilings; 5 sm visibility; and no rain. I made one last final scan of all weather and noticed a 5 sm and 'VFR clear' on foreflight from an airport just a few miles to the south. With good weather in hand and confidence in my abilities to make the approach safely; I proceeded to do the approach. As I descended to the final approach fix I noticed that the clouds were broken in areas. I could hazily see in front of me; but clearly saw the ground off the left wing in patches and holes; and off the right wing with a little less clarity. I was able to see and make out distinct buildings; farm houses; and roads. This all aligned with my map overlay of the approach I was flying. I descended down to the approach. The ceiling at the time of the final approach; and up to 3 hours later; was reported as 900 ft overcast and 5 sm. I flew down to the final approach fix and descended to the circling approach minimums. I felt that these minimums gave me a clear safety margin and time to execute a go-around while I would proceed to do the missed approach procedure if necessary. I positively identified that I had broken out of the clouds. Ahead of me was still surrounded in the very shallowest of white; but to the left and the right I had broken out at700 feet AGL. It was thin enough in front of me that it felt more like a haze than still being in IMC. I had not yet reached the decision point but was beginning to faintly see the plowed field of the airport.Moments later; I clearly saw the runway environment and landed safely. I saw the numbers of the runway through the haze and positively established the runway environment. Factors that added to my desire to write an ASRS report were few. In retrospect; I reviewed the NOTAMs for one of the METAR stations that I was using as a secondary source for the ceilings of the flight. Many hours later that evening; I saw that every airport within a 100 NM radius was 400 ft overcast and less than 1 SM visibility EXCEPT for one airport. This particular METAR was reporting the low visibility; but as 'VFR.' It was only hours after the fact that I had landed safely on the ground that I realized that this particular ground station had been NOTAMd out as being unreliable on cloud clearances. It wasn't my primary weather reporting reference; nor was it the one that was called for in the instrument approach; but it put in further doubt about how 100% confident I had been in my information. In a zoomed out view; I was looking at weather radar/thunderstorm returns. By getting a grand overview of the flight category and type of approaches; I chose the airport with the highest ceilings and best surrounding weather. The airport I chose had no individual ASOS; and was reliant on the weather from 8 nm over. However; I didn't immediately know that when I picked the airport; and the ceilings were remaining high enough that it didn't concern me. I wanted to fill out a safety report so maybe other pilots wouldn't see erroneous metar information on their weather information. Even though it had been NOTAM'd out; it was still 'present' on my devices and causes conflicting information. I think this is a human factors and perceptions safety issue. While there was no violation of cloud clearances or minimums because of the bad METAR; it still has had a lasting effect on my perceived 'correctness' of my information and how the large scope of information was tainted by one bad METAR. In the future; I will pick 4 METARs. One north; south; west; and east of my IFR destination and ensure that they are reporting correctly and not NOTAM'd out before trusting my information to them.




Synopsis: PA-28 pilot successfully used all weather reports available to select best airport for landing to wait out passing thunderstorms. The pilot chose the airport because the ground station reported the airport as VFR clear. Hours later; the pilot discovered that the ground station had a NOTAM for being unreliable on cloud clearances.