Narrative:

Forecast and current metars suggested ceilings between 1200-1800 feet for entire route of flight (departure; midway airports; and destination). Flight flew through koak class C; with destination of kdvo. It was a flight below sfo class B. After handoff from koak tower to norcal; just to the north west of koak and over the bay; ceilings began to lower quickly. I descended believing that could get below cloud deck; as typically ceilings are low eastward from golden gate bridge; but rise quickly once past prevailing fog bank. Near the bay bridge; I asked norcal for pop-up IFR clearance; but they stated that they could only give it to me if I could climb via my own terrain clearance through 3000 MSL. This was not possible; as the ceilings were too low. Shortly thereafter norcal handed me off to oakland center. I also requested pop-up IFR clearance from them; but they also said they could only give it to me if I could climb with my own terrain clearance through 3000 MSL; which was not possible. At this point it was not safe to undertake a 180 degree turn (due to rising terrain and structures to the immediate east and west of my route; nor descend lower because of my proximity to the bay. I exercised my PIC under distress authority for safety and proceeded to climb in IMC. Oakland provided a heading and asked that I climb to 4000. Upon reaching 2500; I was in VMC and communicated such to oakland center; and cancelled my declared distress. They then provided an IFR clearance to kdvo. Shortly thereafter; kdvo was in sight and in VFR conditions. I cancelled the IFR clearance and was told squawk VFR and switch frequencies.I have flown this route over 50 times; often with similar forecast ceilings. Those successful flights caused me to have an optimistic bias; where my expectations affected my perception of the risks; which led me to venture into a situation where I was left with no viable alternatives to safely fly VFR.

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Original NASA ASRS Text

Title: Piper Meridian pilot reported climbing through IMC after low ceilings below ATC vector altitudes caused the flight to be in a distressed situation.

Narrative: Forecast and current METARS suggested ceilings between 1200-1800 feet for entire route of flight (departure; midway airports; and destination). Flight flew through KOAK Class C; with destination of KDVO. It was a flight below SFO Class B. After handoff from KOAK tower to NorCal; just to the North West of KOAK and over the Bay; ceilings began to lower quickly. I descended believing that could get below cloud deck; as typically ceilings are low eastward from Golden Gate Bridge; but rise quickly once past prevailing fog bank. Near the Bay Bridge; I asked NorCal for pop-up IFR clearance; but they stated that they could only give it to me if I could climb via my own terrain clearance through 3000 MSL. This was not possible; as the ceilings were too low. Shortly thereafter NorCal handed me off to Oakland Center. I also requested pop-up IFR clearance from them; but they also said they could only give it to me if I could climb with my own terrain clearance through 3000 MSL; which was not possible. At this point it was not safe to undertake a 180 degree turn (due to rising terrain and structures to the immediate east and west of my route; nor descend lower because of my proximity to the Bay. I exercised my PIC under distress authority for safety and proceeded to climb in IMC. Oakland provided a heading and asked that I climb to 4000. Upon reaching 2500; I was in VMC and communicated such to Oakland Center; and cancelled my declared distress. They then provided an IFR clearance to KDVO. Shortly thereafter; KDVO was in sight and in VFR conditions. I cancelled the IFR clearance and was told squawk VFR and switch frequencies.I have flown this route over 50 times; often with similar forecast ceilings. Those successful flights caused me to have an optimistic bias; where my expectations affected my perception of the risks; which led me to venture into a situation where I was left with no viable alternatives to safely fly VFR.

Data retrieved from NASA's ASRS site 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.