Narrative:

I was one of 7 balloons flying early, prior to the watsonville air show. The winds were very light and landing places hard to find. The ground drift was to the north, but at about 800 ft MSL, there was southerly drift just below the overcast. I was so intent on controling my drift in this thin layer that I was sucked up into the 1100 ft overcast. I did not climb through it or lose ground contact. The very moist air below the base of a cloud layer is colder than the air below, and when a hot air balloon gets close to the bottom of the colder clouds, it can be lifted or sucked up into the clouds inadvertently. Other balloons had this same occurrence the same day. I landed safely back on the airport after a 1/2 hour flight.

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Original NASA ASRS Text

Title: HOT AIR BALLOON FLYING IN A SMALL LAYER OF SOUTHERLY DRIFTING AIR JUST BELOW OVCST LAYER IS SUCKED UP INTO CLOUDS BRIEFLY.

Narrative: I WAS ONE OF 7 BALLOONS FLYING EARLY, PRIOR TO THE WATSONVILLE AIR SHOW. THE WINDS WERE VERY LIGHT AND LNDG PLACES HARD TO FIND. THE GND DRIFT WAS TO THE N, BUT AT ABOUT 800 FT MSL, THERE WAS SOUTHERLY DRIFT JUST BELOW THE OVCST. I WAS SO INTENT ON CTLING MY DRIFT IN THIS THIN LAYER THAT I WAS SUCKED UP INTO THE 1100 FT OVCST. I DID NOT CLB THROUGH IT OR LOSE GND CONTACT. THE VERY MOIST AIR BELOW THE BASE OF A CLOUD LAYER IS COLDER THAN THE AIR BELOW, AND WHEN A HOT AIR BALLOON GETS CLOSE TO THE BOTTOM OF THE COLDER CLOUDS, IT CAN BE LIFTED OR SUCKED UP INTO THE CLOUDS INADVERTENTLY. OTHER BALLOONS HAD THIS SAME OCCURRENCE THE SAME DAY. I LANDED SAFELY BACK ON THE ARPT AFTER A 1/2 HR FLT.

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.