Narrative:

I was departing ZZZ1 airport in VFR conditions (2500 ft at 3 mile visibility). My plan was to pick up a prefiled clearance airborne in the ZZZ area. I have done this clearance pickup many times before and it works well. On this day the WX closed in shortly after takeoff. My option to return to the (uncontrolled) field was gone. I decided to climb to VFR conditions on top (7500 ft). The climb took three to four minutes (very uncomfortable minutes) while trying to reach ZZZ2 approach. I received my clearance to ZZZ about the time I broke out on top. This was a flight that should have been delayed until conditions improved. But I had done this same departure many times before and had always been able to maintain VFR until getting an IFR clearance. Let this be a lesson to me! Be careful out there! Callback conversation with reporter revealed the following information: the WX encountered was different than received during the preflight briefing.

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Original NASA ASRS Text

Title: DEPARTING AN UNCTLED ARPT INTENDING TO PICK UP A FILED IFR CLRNC; A PA31 PLT ENCOUNTERS DETERIORATING WX. UNABLE TO RETURN OR RECEIVE CLRNC; SEVERAL MINUTES IMC CLB IS COMPLETED BEFORE RECEIVING CLRNC.

Narrative: I WAS DEPARTING ZZZ1 AIRPORT IN VFR CONDITIONS (2500 FT AT 3 MILE VISIBILITY). MY PLAN WAS TO PICK UP A PREFILED CLRNC AIRBORNE IN THE ZZZ AREA. I HAVE DONE THIS CLRNC PICKUP MANY TIMES BEFORE AND IT WORKS WELL. ON THIS DAY THE WX CLOSED IN SHORTLY AFTER TKOF. MY OPTION TO RETURN TO THE (UNCTLED) FIELD WAS GONE. I DECIDED TO CLB TO VFR CONDITIONS ON TOP (7500 FT). THE CLB TOOK THREE TO FOUR MINUTES (VERY UNCOMFORTABLE MINUTES) WHILE TRYING TO REACH ZZZ2 APCH. I RECEIVED MY CLRNC TO ZZZ ABOUT THE TIME I BROKE OUT ON TOP. THIS WAS A FLT THAT SHOULD HAVE BEEN DELAYED UNTIL CONDITIONS IMPROVED. BUT I HAD DONE THIS SAME DEP MANY TIMES BEFORE AND HAD ALWAYS BEEN ABLE TO MAINTAIN VFR UNTIL GETTING AN IFR CLRNC. LET THIS BE A LESSON TO ME! BE CAREFUL OUT THERE! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE WX ENCOUNTERED WAS DIFFERENT THAN RECEIVED DURING THE PREFLT BRIEFING.

Data retrieved from NASA's ASRS site as of January 2009 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.