IMC CONDITIONS ON A VFR NIGHT FLT.

Narrative

I WAS ON A FLT FOR THE PURPOSE OF GOING ON MY VACATION IN DEST; FL. LANDED AT MOB TO REFUEL AND CHK WX. WX HAD BEEN GOOD VFR PRIOR TO MOB (NO CEILINGS; VIS LESS THAN 7); BUT AT MOB; VIS WENT DOWN TO 6/HAZE. FSS BRIEFER TOLD ME THAT EGLIN AFB WAS RPTING PARTIAL OBSCURATION; 900 BROKEN; 1500 OVCST; 3 FOG/HAZE. MOB HAD GONE TO 900 BKNA DN 4 H (HAZE). THE BRIEFER WAS QUICK TO TELL ME ALL TERMINAL; INCLUDING MOB; PNS; AND PANAMA CITY WERE CALLING FOR CEILINGS OF NO LESS THAN 20000' AND VIS OF 6 OR GREATER; ALL THROUGH THE NIGHT. THE BRIEFER WENT ON TO ENCOURAGE ME THAT I SHOULD ATTEMPT THE FLT; SINCE IT WAS ONLY A LITTLE SCUD THAT WOULD SOON DISSIPATE. SCUD RAN ALL THE WAY TO PNS AT AND BELOW 1500' MSL. PASSED PNS AND NOTICED WX WAS REALLY GOING DOWN. SUDDENLY I WAS IN THE CLOUDS AND STAYED IN THEM FOR 20 SECS OR SO. IMMEDIATELY DID 180 DEG TURN BACK TO PNS AND HAD TO DSND TO 600' AGL TO GET OUT OF CLOUDS. ESTIMATE CEILINGS WERE AT OR BELOW 1000' AGL AT PNS; EVEN THOUGH THE WX RPT CALLED IT 1200' BROKEN AND 4 F. DIDN'T FILE IFR BECAUSE PLANE WAS SMA W/O INSTRUMENT CERTIFICATION. ALSO; THE VOR HAD GONE OUT HALFWAY THROUGH THE FLT. I SAW NO NEED FOR FILING IFR SINCE ALL WX RPTS AND FORECASTS AT INITIAL DEP SHOWED EXCELLENT VFR. AT THE DEP PORTION FROM MOB; I SHOULDN'T HAVE GONE. I EXERCISED POOR JUDGEMENT BY LETTING THE FSS BRIEFER GIVE AN OVER OPTIMISTIC OUTLOOK ON THE WX CONDITIONS. ALSO; THE WX ALONG THE GULF COAST CAN CHANGE VERY RAPIDLY. WHAT I DID WAS STUPID!