Narrative:

Situation occurred while practicing takeoffs/lndgs (to full stops) using left closed traffic for runway 12 at palo alto. Although light rain was falling the WX appeared to be on an improving trend with periods of sunshine. On my 5TH circuit while on the downwind leg I noticed what appeared to be some isolated low 'scud' floating across the approach end of runway 12. I began a slight climb to remain clear and reported to the tower controller that I would need to extend my downwind to maneuver past the cloud. Within a few seconds I found myself in solid IMC at 1000 ft AGL. I immediately reported my situation to tower and began a climb and held a 350 degree heading. Tower immediately instructed me to contact bay approach who subsequently instructed me to climb and maintain 2000 ft and began vectoring me for the sjc ILS runway 12 approach after determining that I was instrument capable and not in a fuel critical state. I was cleared for the approach and landed at sjc without incident. It turned out that the isolated 'scud' was the leading edge of an unforecast 500 ft ceiling which moved in rapidly from the west. A better perception of the extent and nature of rapidly changing meteorological conditions may have allowed for more time and room to maneuver clear. Other aircraft were in the traffic pattern and I therefore elected not to attempt a rapid 180 degree turn.

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Original NASA ASRS Text

Title: C182 SHOOTING LNDGS, ENCOUNTERED IMC WX AND HAD TO GET ATC SVC. HE WAS CLRED TO SJC WHERE HE MADE AN ILS APCH. WX FORECAST DID NOT INDICATE THE ONSET OF LOW CEILINGS. THE RPTR AND THE ACFT WERE INST CERTIFIED.

Narrative: SIT OCCURRED WHILE PRACTICING TKOFS/LNDGS (TO FULL STOPS) USING L CLOSED TFC FOR RWY 12 AT PALO ALTO. ALTHOUGH LIGHT RAIN WAS FALLING THE WX APPEARED TO BE ON AN IMPROVING TREND WITH PERIODS OF SUNSHINE. ON MY 5TH CIRCUIT WHILE ON THE DOWNWIND LEG I NOTICED WHAT APPEARED TO BE SOME ISOLATED LOW 'SCUD' FLOATING ACROSS THE APCH END OF RWY 12. I BEGAN A SLIGHT CLB TO REMAIN CLR AND RPTED TO THE TWR CTLR THAT I WOULD NEED TO EXTEND MY DOWNWIND TO MANEUVER PAST THE CLOUD. WITHIN A FEW SECONDS I FOUND MYSELF IN SOLID IMC AT 1000 FT AGL. I IMMEDIATELY RPTED MY SIT TO TWR AND BEGAN A CLB AND HELD A 350 DEG HDG. TWR IMMEDIATELY INSTRUCTED ME TO CONTACT BAY APCH WHO SUBSEQUENTLY INSTRUCTED ME TO CLB AND MAINTAIN 2000 FT AND BEGAN VECTORING ME FOR THE SJC ILS RWY 12 APCH AFTER DETERMINING THAT I WAS INST CAPABLE AND NOT IN A FUEL CRITICAL STATE. I WAS CLRED FOR THE APCH AND LANDED AT SJC WITHOUT INCIDENT. IT TURNED OUT THAT THE ISOLATED 'SCUD' WAS THE LEADING EDGE OF AN UNFORECAST 500 FT CEILING WHICH MOVED IN RAPIDLY FROM THE W. A BETTER PERCEPTION OF THE EXTENT AND NATURE OF RAPIDLY CHANGING METEOROLOGICAL CONDITIONS MAY HAVE ALLOWED FOR MORE TIME AND ROOM TO MANEUVER CLR. OTHER ACFT WERE IN THE TFC PATTERN AND I THEREFORE ELECTED NOT TO ATTEMPT A RAPID 180 DEG TURN.

Data retrieved from NASA's ASRS site as of July 2007 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.