Date: 201211
Local time of day: 0601-1200
Location: IOW.Airport, IA
Weather elements / visibility: Fog; 1
Light: Daylight
Aircraft: PA-32 Cherokee Six/Lance/Saratoga/6X
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class E ZAU
ATC / advisory: Center ZAU
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Other / Unknown
Anomaly: Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Landed As Precaution
Contributing factors: Human Factors; Weather
Primary problem: Human Factors

Narrative: I performed my online flight briefing the night before and filed two of my three IFR flight plans via DUATS from home before going to bed. A review of the weather indicated good conditions at home and an expected cloud deck about 5;000 FT at my pickup destination before continuing on to IOW in VFR conditions; with the continued possibility of an overcast layer at 5;000 FT. Temperatures were forecast well above freezing; and wind was not a concern. The forecast included a possibility of fog at IOW; but it was expected to lift well before my ETA. [Next morning] I left for the airport; pre-flighted and departed to my pickup destination. Weather was as forecast; and I soon found myself on-top at 7000 feet. The arrival into the pickup destination was uneventful. I fueled the aircraft and loaded the four passengers and we departed visually; picking up our clearance airborne from Chicago Center. Once on our IFR flight plan and cruising at 4;000 FT under the overcast on autopilot; I punched IOW into my hand-held Garmin GPS 496. At this moment; I noticed the red weather flag on IOW. This caught me completely by surprise. XM weather reported the current conditions at IOW as 200 FT overcast and 1 mile visibility. Given the current time; the forecast of lifting fog was incorrect; and I faced the reality that I had just departed without checking the weather at my destination. I also had no alternate listed on my flight plan.I pulled-up the approach plates for IOW. The GPS approach has a MDA of 444 FT AGL and a visibility requirement of 1 mile. I make a point of not starting an approach I do not plan to complete; so I decided that unless I had at least a 500 FT ceiling; I would not continue to IOW. Using the GPS; the best alternate appeared to be MLI; it was along our route of flight and reporting VFR conditions. I continued to monitor the weather at IOW until we were 15 minutes from MLI. I had also reviewed the approach plates for MLI; and was prepared for the ILS 27. I was being controlled by Quad City Approach and notified them I wanted to divert to MLI. Approach cleared me to MLI and told me to expect the ILS 27. The landing at MLI was uneventful.In retrospect; none of this should have happened. I know better than to takeoff for a destination without reviewing weather; but I did it anyways. The weather en route to my pickup destination was as forecast; and I assumed -- wrongfully so -- that IOW's weather was also as forecast. In the end; we were not able to continue to IOW; and the passengers ended up renting a car and I returned home. Given today's ease of information acquisition; I cannot excuse my behavior. Two things I did right; however; were to load the maximum allowable fuel; nearly three hours more than required for our trip. Second; as soon as I realized my error; I began alternative planning. Using XM weather; I reviewed the current weather conditions for all airports within a reasonable distance of IOW and found MLI to be the best choice for an alternate. Once that decision was made; I treated MLI as my official alternate and executed that plan once IOW was out of the question.




Synopsis: While airborne using XM weather; a PA32 pilot discovers that his destination is IFR and below minimums. The forecast the night before was for VMC at the ETA and no alternate was filed. Reporter diverts to a suitable alternate.