The pilot was flying the balloon as a commercial revenue sight-seeing flight with 20 passengers on board. The pilot reported that during the inflation of the hot air balloon about 30 minutes prior to the accident, the weather was clear skies and calm wind. The pilot reported that he was about 10 minutes behind the other balloons, so he was able to observe their flight path through the valley. Prior to the accident, the pilot noted the airspeed was about 16 miles per hour, which he thought unusual for the location of the flight. As he had observed the other balloonists do, he placed his balloon in a controlled descent, with the intent of traversing the same section of the valley as the other balloons. This part of the tour would take them over the vineyards and through the center of the valley. During the controlled descent, the pilot reported that it felt like the balloon was being pushed down, which he attributed to wind shear. The bottom portion of the balloon's basket subsequently contacted the top of a 30-foot wooden power pole and simultaneously the backside of the envelope was pushed toward the burners, which caused several structural panels to be burned. The pilot continued the flight for another 1.5 miles in order to make a safe landing in a park. The pilot landed the balloon without further incident. The company indicated that the pilot received his weather briefing from the National Weather Service, but did not say at what time; only that the wind was calm. Thirty minutes before departure, recorded weather at a nearby airport indicated that the wind was calm. Approximately 30 minutes after the accident, the recorded weather at the same airport reported that the wind was from the west at 5 knots.